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8044477 | Planned change theory: survey of nursing periodical literature. | In response to pilot study suggestions, researchers surveyed 176 items of nursing periodical literature which used 58 planned change theories and six nursing research utilization models between 1982 and 1992. The study identified planned change theories and described the frequency and type of use. |
8044476 | Ergonomics in the laboratory environment. | The focus of this report is how ergonomics--the art of making equipment fit the user--is applied to video display terminal (VDT) use in order to improve productivity. It is recommended that VDT operators be made more comfortable by using ergonomic chairs and tables. The placement of computer screens and keyboards at the workstations should be tailored to the body and its natural motion in order to decrease physical stress. |
8044475 | Introducing a two-way wireless communication system. | Three medical/surgical units in a Midwestern medical center introduced a two-way wireless communication system to test its effect on environmental noise, staff communication, timeliness of response to patient requests, nurse fatigue and job satisfaction. Data were collected through focus groups, surveys, pedometer studies and work sampling. Results provide for nurse managers the first objective evaluation of the potential of this new device and a framework for designing other nursing evaluations of the effects of a new technology. |
8044474 | Introducing new technology: confusion or order? | A model is explained for assessing the components and potential relationships which should be considered before introduction of a new or updated piece of equipment, improved supplies or a new process in nursing care. Some principles are offered to direct the weighting of various factors involved in selecting and implementing the introduction of new technology. Use of such a model can reduce staff frustration and improve quality of patient care. |
8044473 | Implementing a nursing administration local area network. | Several factors should be considered in planning and implementing a nursing administration Local Area Network (LAN). Initial support from nursing management and your organization's information systems department are key to successful acceptance by hospital administration. Involvement of all users and support staff in the process will assure acceptance and an efficient roll-out. Flexibility is critical as the best-laid plans suffer delays when a large project is initiated. Adequate support will assure a smoother process for implementing and maintaining a nursing LAN. |
8044472 | Automation at the point of care. | Clinical Information Systems (CISs) are systems of microcomputers used at patient bedsides to collect, process, retrieve and display information related to patient care. At our facility, 65 terminals are used in selected units and the CIS has virtually replaced paper charts in daily practice and documentation. Though currently employed in only a small number of hospitals, the use of CISs is expected to grow rapidly during the coming decade. |
8044466 | The role of cutinase in fungal pathogenicity. | Cutinase, an extracellular fungal enzyme, is thought to be essential for the pathogenicity of certain fungal species to plants. Interpretations of recent data on fungal cutinase activity and pathogenicity are contradictory, and range from cutinase having no apparent influence on pathogenicity to it enhancing adhesion of fungal spores to the plant surface. |
8044465 | Iron acquisition in microbial pathogenesis. | Successful competition for iron by potential pathogens is essential to establish infection. The roles of the various types of microbial iron acquisition systems in host-pathogen interactions depend on the nature of the infection and the location of the pathogen within the host. Microbes infecting the extracellular spaces of the host employ different strategies for iron acquisition than those that invade and multiply within host cells. |
8044464 | Antibody-mediated clearance of viruses from the mammalian central nervous system. | The novel role of antibody in clearing virus from the central nervous system without the help of other immune effectors is an important phenomenon that has only recently been documented. Possible routes for antibodies across the blood-brain barrier and how they work in the CNS are discussed here. |
8044463 | Adaptive surface variation in mycoplasmas. | Mycoplasmas excel as infectious agents, despite their very small genomes. In one mycoplasma species, adaptive flexibility is enhanced by an elegant genetic system that diversifies the membrane surface through a set of variable lipoproteins (Vlps). A family of vlp genes supplies divergent coding sequences and undergoes high-frequency mutations, thus creating large repertoires of surface mosaics and structural variants. |
8044462 | Recognition between Candida albicans and host cells. | The cell surface of Candida albicans is a complex mosaic of polysaccharide and protein, of which mannoproteins constitute the major antigens and host cell recognition molecules. One group of mannoproteins is known as 'adhesins' and has properties similar to lectins and integrins. The adhesins recognize either host cell fucosyl glycosides or peptides containing the amino acid sequence arginine-glycine-aspartic acid (RGD peptides). |
8044461 | Nonchemical signals used for host location and invasion by fungal pathogens. | Not all aspects of the interactions between fungal pathogens and their hosts are mediated by specific chemical signals, but until recently the functional significance of nonchemical cues (such as local electrical fields, pH gradients and host surface topography) was obscure. Recent studies of the mechanisms underlying fungal tropisms and taxes to such cues have revealed novel architectural and physiological properties of the fungal cells that contribute to their success as pathogens. |
8044457 | Petechial haemorrhage following a partial seizure with secondary generalization: atypical presentation and differential diagnosis. | A case is reported of a patient who had a respiratory arrest on a high dependency ward in a High Security Hospital with an unusual presentation. The patient had head and upper abdominal petechial haemorrhages with extensive conjunctival haemorrhaging. A considered antecedent for this potentially life-threatening presentation was strangulation. Analysis of all the available clinical information supports the hypothesis that he had a single tonic-clonic seizure with a focal-motor onset. This constitutes an unusual consequence of a partial seizure with secondary generalization. |
8044456 | Photosensitive epilepsy in children. | We performed a retrospective analysis of 17 children with photosensitive seizures (PSS) who had been followed for more than 3 years (mean: 9 years). PSS were verified in all patients by simultaneous video-EEG monitoring. The seizures were precipitated by flickering stroboscopes (14 patients) or were induced by patients themselves (3) with head-nodding in front of illumination, blinking at television or close viewing of striped patterns. PSS consisted of myoclonic seizures (eight patients), generalized tonic-clonic convulsions (5), partial seizures (3) or atypical absence (1). According to the International Classification of Epileptic Syndrome, three patients were classified as having severe myoclonic epilepsy in infancy and five as having juvenile myoclonic epilepsy. The remaining nine could not be categorized as any specific epileptic syndrome. Children with age of the onset of epilepsy at 7 years or younger tended to suffer intellectual deficit in addition to intractable seizures. |
8044455 | Decreased seizure frequency after withdrawal and reinstitution of antiepileptic drug therapy. | We reviewed the seizure frequencies of 38 patients with medically refractory epilepsy 6 weeks before (baseline) and 3 weeks after withdrawing their antiepileptic drugs (AEDs) for video-EEG monitoring. Seizure frequency during the first 3 weeks after restarting AEDs was diminished compared with baseline (P < 0.05). We found no correlation between seizure frequency and patient age, specific antiepileptic drugs, number of seizures during the video-EEG monitoring, number of days without AEDs, or partial vs total withdrawal of AEDs. Medication tachyphylaxis, functional tolerance, or long term post-ictal depression of the seizure threshold is hypothesized. The diminished seizure frequency after reinstitution of medications in four of five patients who did not have seizures during their hospitalization suggests that drug tachyphylaxis is a relevant mechanism. |
8044454 | Surface cortical cerebral blood flow monitoring and single photon emission computed tomography: prognostic factors for selecting temporal lobectomy candidates. | A series of 23 patients with medically intractable temporal lobe epilepsy was studied with surface cortical cerebral blood flow monitoring, single photon emission computed tomography (SPECT) and subdural strip electrocorticographic (ECoG) monitoring for localization of the seizure focus. All patients underwent anterior temporal lobectomy and seizure outcome was determined after a mean of 9 months (range: 3-17 months). Invasive and non-invasive cerebral blood flow (CBF) parameters with prognostic value for seizure-free outcome were: (a) inter-ictal seizure focus with CBF < 65 ml/100 gm-min; (b) inter-ictal seizure focus CBF < or = normal temporal lobe CBF; and (c) concordance of inter-ictal and/or early post-ictal SPECT and ictal ECoG for seizure focus localization. These results should improve prognostic value of invasive and non-invasive cerebral blood flow data for selection of temporal lobectomy candidates. |
8044452 | An outcome audit at the epilepsy clinic: results from 1000 consecutive referrals. | The clinical details, specialist investigation, pharmacological treatment and outcome in 1000 consecutive patients referred to the epilepsy clinic at the Western Infirmary in Glasgow were reviewed. Data were collected by detailed proforma at initial referral and from the clinical notes at audit. 524 (52%) of the patients were 30 years of age or younger. 527 (53%) were sent to the clinic by their general practitioner with the majority of the remainder being referred by another hospital consultant. 240 (24%) came from outwith greater Glasgow. In 253 (25%) patients a possible predisposing factor was identified, usually a major head injury or alcohol abuse. Sixty (6%) patients suffered from additional mental handicap. Focal spike and wave activity was identified in 26% of electroencephalograms. One or more abnormality was found in 33% of the 356 patients who underwent computerized tomographic brain scanning. In 13 (11%) of these, a tumour was demonstrated. On referral, 65% of patients were being treated with antiepileptic drugs; 58% were on monotherapy and 42% took more than one anticonvulsant. The figure at audit was 77% treated, with a higher proportion (68%) than at referral receiving monotherapy (P < 0.005). Sedative anticonvulsants, such as phenobarbitone and primidone, were withdrawn in 29% of cases. 50% of the 519 patients, for whom seizure frequency data were available for the years before referral and audit, were seizure-free and seizure numbers had been reduced by 50% or more in a further 23%. A poorer response to treatment was associated with mental handicap (P < 0.05), birth injury (P < 0.01), and partial or secondary generalized seizures (P < 0.005). |
8044451 | Neuropsychological effects of tiagabine, a potential new antiepileptic drug. | The neuropsychological effects of the GABA-reuptake blocker, tiagabine-HCl, were tested in an open trial of 22 adult patients with refractory partial epilepsy followed by a double-blind, placebo-controlled, cross-over trial in 12 subjects. Nineteen patients completed the initial open titration and fixed-dose phase of the study and 11 patients completed the double-blind phase. The median daily tiagabine dose was 32 mg during the open fixed dose and 24 mg during the double-blind periods. Neuropsychological evaluation did not show any significant effect on cognitive function in the open or double-blind phases. In this group of patients no statistically significant difference in the frequency of the total number of seizures or complex partial seizures was found in the open or double-blind stages. Seizure severity was significantly less in the open fixed dose than in the baseline period, but was not significantly different between the two double-blind periods. Reported side effects were transient, most commonly aggression/irritability, lethargy, headache and drowsiness. No significant EEG changes were observed. |
8044450 | Towards a comprehensive neuropsychological service in the United Kingdom for adult patients being considered for epilepsy surgery. | We report the findings of two one-day meetings concerned with the current practice of clinical neuropsychologists involved in epilepsy surgery in Britain. Nine centres participated in the survey, the aim of which was to examine the strengths and current weaknesses in the services provided nationally and move toward further development. Each centre was asked to provide information via a questionnaire on three definitive areas: patient and family expectations and psychological health; neuropsychological protocol pre- and post-surgery; the intra-carotid sodium amytal protocol. Results of the survey revealed diverse practices across the three areas. Implications and recommendations for a uniformed approach have been made and a standard approach to assessing outcome is being further investigated by the epilepsy surgery group. However, the authors argue that a review of the whole of neuropsychological services for epilepsy and surgery is required. |
8044448 | Cognitive performance in learning disabled children with and without epilepsy. | Cognitive functioning and educational achievement were examined in learning disabled children with epilepsy (n = 65) and without epilepsy (n = 122) in order to explore whether children with epilepsy show unique types of learning problems, different from those in other learning disabled children. The learning disabled children with epilepsy tended to perform better on tests of verbal intelligence, certain achievement-related abilities and were better in one area of academic achievement, i.e. spelling. Despite their superior performance in these areas, the learning disabled children with epilepsy were slower than those without epilepsy and regular education controls (n = 100) on simple auditory and visual reaction tasks as well as on a multiple decision reaction task and a visual searching task. The results obtained with the school achievement tasks provide no clear evidence for specific types of learning impairment in children with epilepsy. Learning disabled children with epilepsy do not appear to have educational needs different from those of other learning disabled children. |
8044446 | Violence and the homeless: an epidemiologic study of victimization and aggression. | The present study is a random, systematic study of 900 homeless subjects in St. Louis that describes violence in their lives, both in terms of victimization, by specific violent traumatic events, and victimizing with recognized aggressive behaviors. Many subjects had experienced a traumatic event, and post-traumatic stress disorder was very common. Substance abuse and other Axis I disorders were associated with a history of a traumatic event. The majority of men and a substantial proportion of women also had a history of physically aggressive behaviors, often beginning in childhood. Aggressive adult behavior was associated with substance abuse and major depression. The aggressive behaviors usually predated homelessness, and about half continued after the individual had become homeless. Therefore, it is seen that violence is very much a part of the lives of the homeless, and it seems to be part of a broader picture of problems associated with risk for and experience of homelessness. |
8044445 | The relationship between traumatic exposure, family dysfunction, and post-traumatic stress symptoms in male juvenile offenders. | This study examined some chronic, stressful conditions and some acute, traumatic events which may place youths at risk for specific types of psychopathology. Ninety one delinquent adolescents with histories of serious and repeated crimes were assessed for their exposure to 11 different types of trauma. The subjects were also tested using measures which assess family functioning, and frequency and intensity of Post-Traumatic Stress Disorder (PTSD) symptoms. Results indicated that 24% of the subjects tested met full DSM III-R criteria for PTSD. Both exposure to violence and family dysfunction were significantly associated with PTSD symptomatology. These findings suggest that juvenile offenders may constitute a high risk group for exposure to multiple types of trauma and the development of post-traumatic stress symptoms related to such exposure. This study provides a rationale for future cross-trauma research both within the juvenile offender population and between it and other identified trauma groups. |
8044444 | A comparison of four PTSD measures' convergent validities in Vietnam veterans. | We compared the convergent validities of four commonly used post-traumatic stress disorder (PTSD) measures in 80 help-seeking Vietnam veterans by contrasting their intercorrelations. When scored as continuous severity or frequency measures, the Mississippi Scale for Combat-related PTSD's and the Post-Traumatic Stress Disorder Interview's (PTSD-I's) concordances with other measures were similar to one anothers' and generally larger than those of either the Diagnostic Interview Schedule (DIS) PTSD module or the MMPI PTSD scale. However, when used only to identify stress disorder's presence or absence, the four techniques' concordances were nearly identical. This suggested that the four measures have similar convergent validities when used simply to identify PTSD, but that the PTSD-I and Mississippi scale offer better convergent validity than the MMPI or DIS instruments when used as severity measures. |
8044443 | A nation's response to attack: Israelis' depressive reactions to the Gulf War. | We examined Israelis' reactions to the Gulf War and SCUD missile attacks. Four national samples of Israelis (n = 3,204) were interviewed as to depressive mood on four occasions--prior to the Gulf Crisis, as the war approached, during the SCUD missile attacks, and after cessation of hostilities. There was an expected increase in depressive mood during the period of SCUD missile attacks and a quick return to base-line levels following the hostilities. Less educated and older individuals reported higher base-line levels of depressive mood and were at higher risk for clinical depression. Women and men did not differ in depressive mood before or after the SCUD missile attacks. However, women experienced a marked increase in depressive mood when the SCUD missile attacks occurred. |
8044442 | Cross-cultural response to trauma: a study of traumatic experiences and posttraumatic symptoms in Cambodian refugees. | Despite a growing literature of cross-cultural research on mental illness, little is known about the universality of most psychiatric disorders. This study was designed to determine whether people from a very different culture have the same symptoms in response to traumatic experiences as do trauma survivors in the United States. We were also interested to find out if the severity of the current symptoms is related to the amount of trauma experienced. Furthermore, we gathered information about the perceived severity of traumatic experiences among refugees. Fifty Cambodian refugees living in the U.S. were asked about their traumatic experiences and their current symptoms of posttraumatic stress, dissociation, depression, and anxiety. High levels of all symptoms were found along with statistically significant relationships between each symptom measure and the amount of trauma experienced. We conclude that the basic symptom picture in this group was similar to that observed in U.S. trauma survivors. |
8044441 | Childhood abuse experiences and combat-related PTSD. | Current literature on the etiology of combat-related PTSD strongly implicates combat trauma exposure as a primary etiological factor. However, studies of premilitary variables have produced conflicting results, perhaps in part due to methodological inconsistencies and failure to employ standardized measures. The present study examines one premilitary variable, childhood physical abuse history. Using a standardized measure developed by child abuse researchers, forty-five percent of veterans with PTSD were identified as recipients of abusive physical punishment during childhood. A positive correlation between physical abuse history and severity of combat-related PTSD was found. These preliminary findings set the stage for further investigation of the child abuse variable and underscore the need for treatment of veterans with combat-related PTSD which addresses developmental traumagenic events. |
8044440 | A cognitive model of guilt typology in combat-related PTSD. | Dysfunctional guilt is a prominent feature of combat-related, post-traumatic stress disorder (PTSD). The present article describes a model of combat-related guilt that distinguishes guilt types on the basis of specific false assumptions and errors of logic that are frequently associated with different kinds of traumatic circumstances. Two common types of combat-related guilt based on this conceptualization are described and cognitive relabeling treatment strategies which have a "type" specific focus are outlined. The needs for research on guilt assessment among trauma survivors and for interventions that focus explicitly on guilt management are discussed. |
8044439 | Relationship of cynical hostility and PTSD among Vietnam veterans. | The personality construct of cynical hostility, as measured by the Cook-Medley scale (an MMPI subscale), has been implicated as a risk factor for cardiovascular disease. A literature review suggests that Vietnam veterans exhibit many cynical hostility-like characteristics. We examined the association between Cook-Medley scores and PTSD among Vietnam and other-era veterans. Study 1 involved analyses of data from 1293 MMPIs administered at Department of Veterans Affairs in Honolulu between 1986-1991. Cook-Medley scores were highly correlated with MMPI PTSD scores, and Vietnam Era veterans obtained higher scores than veterans from other eras. In Study 2, twenty nine Vietnam veterans with PTSD disability ratings obtained very high Cook-Medley scores which were higher than Vietnam Era veterans without rated PTSD. Findings indicate that the cynical hostility literature has considerable relevance for study of PTSD and suggest that PTSD veterans may have heightened risk for developing cardiovascular disease. Several directions for future research are suggested. |
8044437 | Self-report versus observer ratings of distress and pathology in Vietnam veterans with PTSD. | Few efforts have been made to examine the relationship between standard self-report measures and observer ratings of distress in veterans suffering from post-traumatic stress disorder (PTSD). In the present study correlations between self-report (verbal ratings and scores on the Brief Symptom Inventory) and observer ratings (scores on the Brief Hopkins Psychiatric Rating Scale) of pathology and distress were analyzed for 40 Vietnam combat veterans participating in a weekly outpatient PTSD therapy program. The relationship of these measures to the Mississippi PTSD scale and measures of combat exposure and duration was also examined. Results suggested that the self report and observer measures of distress were significantly correlated for this group. While written self report and observer ratings were correlated with scores on the Mississippi Scale, verbal self reports of distress were not. However, the verbal self reports of distress were most strongly related to reported combat exposure. |
8044436 | Concepts of normal bereavement. | This study used a 25-item questionnaire to examine the perceptions of 128 people with a close interest in bereavement and its literature. The study is part of a project to identify key aspects and the bereavement process. Subjects were asked to rate their perceptions of key bereavement phenomena with regards their frequency in the acute and later stages of bereavement. Descriptive results are presented and discussed, and a profile of phenomena perceived to be common to both stages is outlined. |
8044435 | Psychosocial correlates of fire disaster among children and adolescents. | This study examined the extent of children's and adolescents' psychosocial maladjustment associated with a natural disaster, namely, wildfire. The course of psychopathology was assessed six weeks after a major wildfire destroyed 420 homes. Victims' functioning relative to a comparison group from the same community, matched for age, gender, socioeconomic status, and fire insurance was examined. The major goal of this study was to assess systematically the short-term mental health consequences of a wildfire disaster among children and adolescents. This goal was achieved through the use of standardized assessment procedures. The results of this study add useful information to the literature concerning the impact of disaster among children and adolescents and provide a methodological framework for future efforts in this area. |
8044434 | Dissociative states induced by relaxation training in a PTSD combat veteran: failure to identify trigger mechanisms. | PTSD is often treated with anxiety management techniques, including relaxation training. A case report is presented which describes a PTSD combat veteran who experienced dissociative states induced by relaxation training. Hypnotherapy subsequently identified traumatic memories which were recalled during relaxation training but triggering mechanisms for the recall of these traumatic memories were not identified. |
8044422 | Transgenic mice expressing human apoB100 and apoB48. | Transgenic mice that express human apolipoprotein (apo)B have been developed by microinjecting fertilized mouse oocytes with an 80 kb genomic DNA fragment that encompasses the entire human APOB gene. In the transgenic mice expressing the largest amounts of human apoB, the concentration of human apoB100 in the plasma is nearly as high as the levels observed in normolipidemic humans (50 mg/dl). Virtually all of the human apoB100 in the transgenic plasma is located in the LDL fraction, resulting in substantially increased levels of LDL cholesterol. These human apoB-transgenic mice should be useful animal models for understanding various aspects of lipoprotein metabolism and for further delineating the role of LDL in atherogenesis. |
8044421 | The apolipoprotein B messenger RNA editing enzyme. | The editing of apolipoprotein (apo)B messenger RNA (mRNA) involves a novel C to U modification, which creates an in-frame stop-translation codon, thereby generating the carboxyl-terminal of apoB48. The 27 kDa catalytic subunit of the editing enzyme has been cloned and established to be a zinc-containing cytidine deaminase. The catalytic subunit is guided to the editing site by a second targeting subunit or subunits. A candidate for the targeting subunit is a 60 kDa protein that can be UV crosslinked to the sequence UGAU, which is part of a motif downstream of the editing site that is essential for editing. |
8044420 | The molecular basis of abetalipoproteinemia. | Abetalipoproteinemia is a recessive genetic disease in humans characterized by the virtual absence of apolipoprotein (apo)B and apoB-containing lipoproteins in plasma. Microsomal triglyceride transfer protein (MTP), a resident lipid transfer protein within the endoplasmic reticulum of hepatocytes and enterocytes, has been shown to be absent in enterocytes from subjects with this disease. MTP is a heterodimer of a unique large subunit and protein disulfide isomerase. It has been demonstrated that the absence of MTP in abetalipoproteinemia is secondary to mutations in the gene for the large subunit of MTP. Thus, mutations in the gene for the large subunit of MTP are a cause of abetalipoproteinemia, which indicates that the MTP is a necessary component for the assembly and secretion of apoB-containing lipoproteins from the liver and intestine. |
8044418 | Molecular genetics of lipoprotein (a): new pieces to the puzzle. | Important advances have been made in the past year in our understanding of the genetics of lipoprotein (a) [Lp(a)]. The apolipoprotein (a) [APO(a)] gene has been cloned and mice have been engineered to express apo(a) and Lp(a). These developments have provided the tools to answer many fundamental questions concerning the genetics, metabolism, and atherogenicity of Lp(a). |
8044417 | Macrophage scavenger receptors. | Macrophage scavenger receptors are integral membrane proteins whose ability to bind and degrade modified LDL has implicated them in the process of atherosclerotic foam cell formation. Their ability to bind non-lipoprotein ligands suggests that they participate in other macrophage-associated host defense activities. Studies utilizing cloned native and mutant forms of the scavenger receptor have provided insights into the structural basis for their function. |
8044416 | Cerebrotendinous xanthomatosis. | Cerebrotendinous xanthomatosis is an autosomal recessive lipid-storage disease caused by mutations in the sterol 27-hydroxylase (CYP27) gene. Recent cloning and characterization of CYP27 enables further analysis and understanding of the pathophysiology of this multisystem disease. Molecular diagnosis provides means for the identification of heterozygotes and pre-symptomatic detection of affected individuals. |
8044415 | The properties of HDL in genetically engineered mice. | Genes involved in HDL structure and metabolism have been overexpressed through the introduction of transgenes or inactivated by gene targeting in mice. These new experimental substrates make it possible to address hypotheses relevant to the biology of HDL that were previously inaccessible through human studies. The in-vivo studies performed to date with these engineered mice have provided insight into structural determinants of HDL, uncovered interactions between proteins that act on HDL and clarified the role that HDL-associated proteins play in atherosclerosis. Further use of these animals, coupled with the development of new engineered lines of mice, should help unravel many questions associated with the in-vivo biological properties and metabolism of HDL. |
8044414 | Structure, function and role of lipoprotein lipase in lipoprotein metabolism. | In the past several years the importance of lipoprotein lipase (LPL) as a multifunctional protein, involved in several different aspects of lipid and lipoprotein metabolism, has become evident. Thus, in addition to its traditional role in mediating the initial hydrolysis of circulating plasma triglycerides, recent studies implicate LPL in the binding of lipoproteins to cell surfaces and receptors, as well as indicating a potential role for LPL in the pathogenesis of atherosclerosis. Enhanced understanding of LPL structure, function and mechanism of action has provided insights into new potential pathways by which defects in LPL function may result in the development of different hyperlipidemic disorders and/or atherosclerosis. |
8044413 | The role of apolipoprotein E in the nervous system. | Human apolipoprotein (apo)E, an important component of plasma lipoprotein metabolism, was recently linked to Alzheimer's disease. Of the three common apoE alleles, epsilon 4 has emerged as a major risk factor. This review summarizes the data leading to this conclusion and discusses possible mechanisms for apoE involvement based on recent biochemical studies. |
8044412 | Postprandial hyperlipidemia and remnant lipoproteins. | Improved methods for quantification of organ-specific contributions to postprandial hyperlipidemia indicate substantial increases in the concentration and altered properties of hepatogenous VLDL, in addition to accumulation of chylomicron remnants. Recent clinical studies support the hypothesis that small chylomicron remnants characterized by apolipoprotein (apo)B48 and VLDL remnants characterized by apolipoprotein B100 are atherogenic lipoproteins. |
8044404 | [Development of a Dutch instrument for the assessment of pain in children]. | The Abu-Saad Pediatric Pain Assessment Tool consists of 30 word descriptors in the sensory, affective and evaluative domains as well as a 10 cm scale that measures present and worst pain experienced by the child. In the first phase of the study an inventory was carried out of pain word descriptors used by hospitalized Dutch children. In the second phase, these word descriptors were given an intensity value on the 10 cm scale by 355 children. An alpha reliability coefficient of 0.83 supported instrument homogeneity. Factor analysis (N - 355) was used to investigate construct validity. A three-factor solution was carried out to evaluate the validity of the three dimensions of pain. Factor 1 consisted of items in the affective and evaluative domains and factors 2 and 3 items from the sensory domain. Ultimately a two-factor solution provided the most intelligible conceptual pattern with the least loss of information. Conceptual composition and discussion of these factors are described and elaborated. |
8044403 | [Level of competence. Relationship to the complexity of nursing care]. | The aim of the study was to investigate the correlation between complexity of nursing care and the level of competence of the nurse. In the study the actual level of competence and the desired level of competence has been distinguished. In total, 105 patients participated in the study. Complexity of care correlates with desired level of competence, but hardly with the actual level of competence. The correlation between complexity and level of competence is higher for new patients than for patients who were receiving care already. |
8044402 | [Effect of work stress, autonomy and social support on the work experience of nurses and caregivers]. | This paper describes a study on the relationship between job characteristics, health and well-being of health care professionals from various sectors (N = 249). More specific, we investigated the Demand-Control-Support Model (Johnson & Hall, 1988), using covariance structure modelling (LISREL 7). Although the data did not confirm the total model, we did found evidence with regard to some predicted relationships. Based on the present data, a revised model was presented. Finally, some practical implications were discussed. |
8044401 | [Information on osteoporosis among ward nurses. Deficient knowledge and need for information regarding osteoporosis in women from 45 to 54 years]. | This article describes the results of a cross-sectional study in which an inventory is made of the level of knowledge of and the need for information about osteoporosis among women in Breda aged 44-54 years. Subsequently the relation between self care agency and the level of knowledge is explored. Orem's self care theory was used as theoretical framework for this study. |
8044392 | Access to the thorax by incision. | For years the standard access to the thorax has been by posterolateral or other muscle cutting thoracotomy incisions. These are accompanied by significant discomfort and often limitation of shoulder girdle movement. To obviate these distressing features, the less traumatic median sternotomy was recommended. In the last ten years, several types of mini or axillary thoracotomies have been described. We believe that the vertical axillary thoracotomy is the best of these incisions as no major muscles are divided, it can be created rapidly, and exposure is excellent. We compared the operative approaches from the point of view of the duration of postoperative hospitalization, the length of the operating time, the incidence of postoperative atelectasis, and persistence of incisional pain. The vertical axillary thoracotomy showed a definite advantage in all these categories. These findings suggest that the vertical axillary thoracotomy is the incision of choice for most thoracic procedures as the incision is small and quickly made. Because there is limited division of muscles, the convalescence is smooth and uncomplicated. |
8044391 | Tc-99 hexamethylpropyleneamineoxide scanning for the detection of acute appendicitis. | Patients with acute lower abdominal pain remain a diagnostic challenge. Although acute appendicitis is the most common surgical disorder, its accurate and timely diagnosis can be difficult. Historically, females of childbearing age are the most difficult patient group in whom to make the diagnosis of acute appendicitis; they have reported negative laparotomy rates ranging from 30 to 50 percent. Tc-99 hexamethylpropyleneamineoxide (HMPAO) labeled leukocyte scan has previously been shown to be very accurate in the detection of acute appendicitis. One year ago, a blinded study using Tc-99 HMPAO labeled leukocyte scan was reported for the detection of acute appendicitis. That study consisted of 27 patients who presented with abdominal pain. The present report is a follow-up study of 37 additional patients in whom the Tc-99 HMPAO leukocyte scan was used to diagnose or discount acute appendicitis. Twenty-seven patients had histologically proved acute appendicitis. Twenty-three of these were correctly diagnosed using the leukocyte scan, for a sensitivity rate of 85 percent. The overall specificity rate was 93 percent, with an overall accuracy rate of 89 percent. Thirty-one of 64 patients were females of reproductive age and represented 56 percent of all patients in the study with appendicitis. In this group, the Tc-99 HMPAO leukocyte scan had a sensitivity rate of 87 percent, specificity rate of 92 percent, and an overall accuracy rate of 89 percent. The Tc-99 HMPAO leukocyte scan also proved to be valuable in the diagnosis of other intra-abdominal inflammatory conditions. Eight scans interpreted as negative for acute appendicitis were positive for other conditions, including five that were positive for diverticulitis, one for a tumor, one for a tubo-ovarian abscess, and one for a small intestinal infarction. The Tc-99 HMPAO leukocyte scan is a highly accurate, diagnostic, and minimally invasive test of use in patients with abdominal pain of unclear cause, in which the differential diagnosis includes acute appendicitis. It is of particular value in females of childbearing age, in whom the cause of lower abdominal pain is unclear. |
8044390 | Quantification of duodenogastric reflux in patients with choledochoduodenostomy. | Frequently, patients present with symptoms after cholecystectomy (pain or discomfort in the upper part of the abdomen, postprandial fullness, bile vomiting, among others). Duodenogastric reflux has been associated with these symptoms in some patients. Therefore, this study was done to investigate this relationship. We evaluated duodenogastric reflux (DGR) in ten healthy patients, in ten patients who had asymptomatic simple cholecystectomy, in ten patients who had asymptomatic cholecystectomy with supraduodenal choledochoduodenostomy (CD), and in ten patients who had cholecystectomy plus CD followed by discomfort in the upper abdomen, postprandial fullness and bile vomiting, but no colicky pain or acute cholangitis. Duodenogastric reflux was quantified using continuous intravenous infusion of technetium-99m labeled hepatoiminodiacetic acid (99mTc-HIDA) and subsequently determining its concentration in gastric juice. All of the patients who underwent operation, whatever the technique used, had higher reflux rates than those in the control group (p < 0.001). Moreover, reflux rates were comparable in the patients who underwent simple cholecystectomy compared with patients in the asymptomatic cholecystectomy plus CD group. Conversely, when patients with cholecystectomy plus CD presented with discomfort in the upper part of the abdomen as well as bile vomiting, they had higher reflux rates than patients who underwent simple cholecystectomy (p < 0.001) and asymptomatic patients with associated CD (p < 0.001). Our results suggest that DGR must be involved in the genesis of these dyspeptic symptoms. |
8044389 | Thromboxane synthetase inhibition and thromboxane receptor blockade preserve pulmonary and circulatory function in a porcine burn sepsis model. | Thromboxane A2 (TxA2) is a key mediator in the pathophysiology of severe burns and sepsis. This study was performed to assess the potential benefits of TxA2 synthetase inhibition and TxA2 receptor blockade in sepsis after severe thermal injury. Pigs with left atrial, aortic, and pulmonary artery catheters received a 40 percent third-degree burn and, 24 hours later, 100 micrograms per kg Escherichia coli endotoxin. The antagonist treatment (BM) group was treated with the TxA2 receptor antagonist BM 13.177, the synthetase treatment (OKY) group with the TxA2 synthetase inhibitor OKY-046, and the control group received saline solution placebo. Another group without burn or endotoxin was used to assess the side effects of BM 13.177. Both drugs significantly attenuated the changes in pulmonary vascular resistance index, cardiac index, arterial PO2, shunt, oxygen delivery, and oxygen consumption seen after endotoxin. However, cardiac index was significantly decreased in group BM before endotoxin. In healthy pigs, BM 13.177 decreased cardiac index and oxygen delivery and increased the pulmonary vascular resistance index. TxA2 synthetase inhibitors and TxA2 receptor blockers are potentially useful in sepsis after severe burns. Comparison between drugs was complicated by the adverse effects of the antagonist, and further investigation with other antagonists is needed. |
8044388 | Combined endoscopic and surgical management of Dieulafoy vascular malformation. | Dieulafoy's disease (exulceratio simplex) is an uncommon cause of gastric hemorrhage as a result of an abnormally large, submucosal, eroded gastric artery, often located in the upper part of the stomach. It represents a clinical challenge because of the intermittent nature of massive bleeding accounting for a constantly fatal course in conservatively (nonsurgically or nonendoscopically) treated patients. Published therapeutic options include techniques of endoscopic hemostasis or operative procedures. Herein we report two patients in whom a combined endoscopic and operative approach was performed to obtain a definitive prevention of rebleeding and an undoubted anatomopathologic diagnosis. Our innovative combined endoscopic and operative approach has offered three significant advantages: endoscopic preoperative diagnosis and control of the bleeding; valid aid in the intraoperative localization of hemorrhagic lesions, which is erratic intraoperatively, requires gastrotomy, and prolongs the duration of operation; and endoscopy-guided limited wedge resection as opposed to standard techniques involving gastrotomy for simple ligation or oversewing of the involved vessel, local excision, or wide wedge resections that used to be recommended until the recent past. We confirm that seemingly obscure origins of massive recurring hemorrhage of the upper part of the gastrointestinal tract should increase the suspicion of Dieulafoy's disease, prompting careful examination of the gastric fundic area and greater curvature. Endoscopic hemostasis is the first choice; whenever operative treatment is indicated (because of the endoscopic or clinical situation), it should be as conservative as possible because of intraoperative endoscopic localization of the bleeding source. |
8044387 | A comparison of operation, endoscopic retrograde cholangiopancreatography, and percutaneous transhepatic cholangiography in biliary complications after hepatic transplantation. | Biliary complications (BC) remain a significant cause of morbidity and mortality after orthotopic liver transplantation (OLT). In an effort to determine the incidence of BC after OLT and the success of management options, 157 hepatic transplants performed from January 1987 to July 1991 were reviewed. The incidence of BC was 25 percent, with a one year mortality rate of 43.5 percent compared with 23.4 percent for patients in a control group (p < 0.05). Most BC occurring before postoperative day 30 presented as leaks, with a one year mortality rate of 50 percent (p < 0.03 versus control group). Biliary complications presenting after postoperative day 30 presented as strictures, with a one year mortality rate of 36.8 percent (p = NS versus control group). Endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTHC), and operative treatment were analyzed to determine relative patency rates after intervention for BC. The analysis showed that ERCP and PTHC were equivalent, with a one year patency rate of 45 percent. Operative treatment had a patency rate of 89 percent (p < 0.05 compared to ERCP and PTHC). The results from ERCP and PTHC may be useful for delineation of rejection versus BC after OLT. However, operative treatment is significantly more effective for definitive treatment of BC after OLT. |
8044386 | The effect of patient size and dose of recombinant human erythropoietin therapy on red blood cell volume expansion in autologous blood donors for elective orthopedic operation. | Recombinant human erythropoietin (EPO) therapy has been known to enhance erythropoiesis and facilitate autologous blood donation before elective orthopedic operations. However, the optimal EPO dose in this setting remains undefined. To help determine this, we have examined the effect of patient weight and EPO dose on red blood cell (RBC) volume expansion. Forty-six nonanemic autologous blood donors enrolled at our institution in two previously reported multicenter clinical trials were analyzed. Patients received either placebo or EPO (150, 300, or 600 units [U] per kg) given intravenously at each of six AB blood type donation visits. Total preoperative RBC volume expansion over a 22 day period was 465 +/- 135 mL (mean +/- SD) in patients receiving a placebo and 588 +/- 201 mL, 735 +/- 144 mL, and 881 +/- 292 mL in patients receiving graded concentrations of EPO. When RBC volume increase was corrected for patient weight and EPO dose, patients receiving placebo or EPO (150, 300, and 600 U per kg) expanded RBC volume by 5.9 mL per kg in patients receiving placebo and 7.9, 9.1, and 10.9 mL per kg in patients receiving EPO, respectively (p < 0.02 for each EPO group compared with placebo group). A direct relationship between EPO dose and RBC volume increase (response) over 22 days was determined by the linear regression equation: RBC volume (mL per kg) = 6.34 + 0.0013X, r = 0.98, where X equals total units EPO administered (per kg body weight). We conclude that EPO dose can be based on anticipated blood losses and transfusion needs in autologous blood donors before orthopedic operation. |
8044385 | Cause and prevention of electrosurgical injuries in laparoscopy. | Electrosurgical injuries occur during laparoscopic operations and are potentially serious. The overall incidence of recognized injuries is between one and two patients per 1,000 operations. The majority go unrecognized at the time of the electrical insult and commonly present three to seven days afterward with fever and pain in the abdomen. Since these injuries appear late the pathophysiology remains speculative. This article reviewed the physics of electrosurgery and provides the surgeon with an insight to the mechanisms responsible in each type of injury. In addition, a comprehensive search of the world literature has reviewed all articles on the topic. The main causes of electrosurgical injuries are: inadvertent touching or grasping of tissue during current application, direct coupling between a portion of intestine and a metal probe that is touching the activated probe, insulation breaks in the electrodes, direct sparking to the intestine from the diathermy probe, and current passage to the intestine from recently coagulated, electrically isolated tissue. The majority of injuries, not surprisingly, are caused by monopolar diathermy. Bipolar diathermy is safer and should be used in preference to monopolar diathermy, especially in anatomically crowded areas. An awareness of the hazards of diathermy together with an understanding of the mechanisms of injury should enable the surgeon to dissect tissue and to achieve hemostasis, while at the same time decreasing the risk of serious complications to the patient. |
8044384 | Acute left colonic diverticulitis in young patients. | This prospective study was done to compare acute left-sided colonic diverticulitis in young patients (50 years of age or less) and older patients (more than 50 years of age) for severity of disease and immediate and late outcome. Of the 265 patients studied, 61 were 50 years of age or less; of these, 49 were men. In all instances, diagnosis was confirmed radiologically or histologically. Operations were performed less often upon younger patients than older patients (15 versus 33 percent, p = 0.001). Severe diverticulitis was found more often in younger men than older men (39 versus 23 percent). After successful conservative treatment during the first hospitalization period, younger men had a statistically greater risk of poor outcome than older men (29 versus 5 percent, p = 0.003). Although younger men have severe acute diverticulitis more often than older men, operative treatment during the first episode is less often needed. On the other hand, after conservative treatment, younger men have a statistically greater chance of poor secondary outcome than older men. |
8044383 | Evaluating the thirty minute interval in emergency cesarean sections. | This study was done to evaluate what percent of emergency cesarean sections are begun within the 30 minute interval between decision and incision time and to evaluate morbidity associated with this time interval. A retrospective patient-control study of records from 75 patients undergoing emergency cesarean sections and two different control groups was undertaken. Sixty-three percent of emergency cesarean sections were begun in less than 30 minutes. A significantly greater number of infants in the group that delivered in less than 30 minutes experienced five minute Apgar scores less than six. There was no significant differences in maternal morbidity associated with emergency cesarean sections. The 30 minute interval is obtainable in a large number of patients but did not have a beneficial effect on neonatal morbidity. There was no significant morbidity seen in the patients who underwent emergency cesarean section. Other measurements of emergency preparedness should be considered other than the 30 minute rule. |
8044382 | Influence of a lymph node environment on invasiveness of metastatic tumor cells. | We investigated the possibility that lymph nodes might increase metastatic efficiency of tumor cells lodged there by measuring changes in tumor cell invasiveness after physical contact with an in vitro approximation of a lymph node environment. The experimental model involved growing Lewis lung carcinoma (LL) or B16 melanoma cells on microcarrier beads, rolling them on a "lymph node endothelial surface," which was created by growing endothelial cells on a differentiating acid extract of lymph node biomatrix, and testing the ability of those tumor cells to invade across matrigel-coated filters at rest (buffer) and in response to a chemotactic stimulus (3T3 conditioned media). Compared with contact with plastic, LL invasiveness was increased fivefold (buffer or conditioned media) and B16 invasiveness fourfold (conditioned media). Tumor cell invasiveness was not increased by exposure to the acid extract of biomatrix alone. Invasiveness to buffer or conditioned media after exposure to endothelial cells alone was 70 and 54 percent (LL) and 42 and 80 percent (B16), respectively, of the invasiveness induced by exposure to both. Compared with invasiveness induced by exposure to lymph node (100 percent), exposure to a "lung endothelial surface" induced invasiveness of 63 and 85 percent (LL) and 40 and 52 percent (B16) to buffer and conditioned media, respectively. Exposure to a hepatic endothelial surface induced invasiveness similar to that induced by lymph node; 90 and 82 percent (LL) and 110 and 86 percent (B16) of lymph node-induced invasiveness. A lymph node environment may modulate the metastatic potential of tumor cells. |
8044381 | Late complications after excisional operation in patients with choledochal cyst. | The follow-up results of 28 patients with choledochal cysts, 16 type I (solitary extrahepatic cyst) and 12 type IVA (extra and intrahepatic cysts), after excision of extrahepatic dilated bile duct were analyzed to evaluate detailed late complications. Hepaticojejunostomy with a wide opening (10 to 30 mm) was created using hepaticoplasty, if necessary, in a Roux-en-Y manner. The mean follow-up period after excisional procedure was 8 +/- 5 (standard error of the mean) years, ranging from one to 18 years. All patients were alive and carcinoma was not observed. Three patients (two with type I and one with type IVA cysts) had intrahepatic calculi. However, they had no evidence of anastomotic stricture on direct cholangiogram, although all bile cultures infected, mainly with Klebsiella and Escherichia coli. Intrahepatic gallstones were successfully treated with percutaneous transhepatic cholangioscopy and reoperation was not required. Thus, intrahepatic calculi associated with cholangitis, but not with anastomotic stricture, were found in 10.7 percent of the patients after excision of choledochal cyst. Long-term follow-up evaluation is necessary, with special attention being given to intrahepatic calculi, even in the absence of an anastomotic stricture. |
8044380 | Cecectomy for complicated appendicitis. | Cecal leak or disruption after appendectomy for complicated appendicitis is a consequence of severity of disease and is related to residual abscess cavity, inflammation, phlegmon, and nonviable intestine. In an attempt to improve results, we have begun to resect the cecum and other localized infected tissue in instances of complicated appendicitis in which the viability of the appendiceal base and adjacent cecum is questionable. This is a prospective series of all patients who have undergone resectional therapy for complicated appendicitis in the last four years. Patients with other inflammatory conditions of the right colon have been specifically excluded. Seventeen patients have undergone resectional therapy for complicated appendicitis. Thirteen (76.5 percent) were men; the mean age was 42.4 years. The mean temperature and leukocyte count were 37.8 degrees C and 16.1 x 10(9) per L, respectively. These patients presented with a mean of 6.8 days of abdominal pain. Nine had a palpable abdominal mass, and all had tenderness in the right lower quadrant. In ten patients an abscess was encountered at operation. While the extent of the resection varied, it generally included the cecum, part of the right colon, and 5 to 7 cm of terminal ileum. Fourteen patients had a primary anastomosis, while the other three had the creation of an ileostomy. Complications were encountered in only two patients: one wound infection and one pulmonary embolus. There were no instances of postoperative intra-abdominal abscess, intestinal obstruction, or fecal fistula. All patients had a benign postoperative course and were discharged on the average of 9.9 days postoperatively. The ileostomies in three patients have been closed and no complications have occurred on follow-up examination. We conclude that aggressive resectional therapy of the cecum during appendectomy in selected patients with complicated appendicitis is effective therapy and can be performed safely. |
8044379 | A neural network classifier in experimental particle physics. | A classification problem in high energy physics has been solved on simulated data using a simple multilayer perceptron comprising binary units which was trained with the CHIR algorithm. The unstable training of such a network on a nonseparable set has been overcome by selecting those weight vectors with good performance while providing a flexible choice of the two types of classification errors. Specific features of the problem have been exploited in order to simplify and optimize the solution which has been compared to the popular backpropagation algorithm and found to perform on a similar level. Additional aspects of this work are the use of the CHIR algorithm on continuous input and incorporating the classic idea of a phi-machine in a multilayer perceptron. |
8044378 | A function approximation algorithm using sequential composition. | A new method for approximating one dimensional functions is developed based on structural capabilities of multilayer feedforward neural networks. It possesses notable but unproven convergence properties which are examined in a series of examples. It is shown that it outperforms conventional networks for complicated one dimensional problems. An adaptive version of the algorithm whose approximation changes to best use the data available is also presented. Experiments indicate that this method is very stable in the presence of noise. For straightforward function approximation however, other conventional routines generally perform better. Nevertheless, noise stability, adaptability and other properties make the new method useful in context. |
8044377 | Trans-dimensional learning. | The main objective of this research paper is to introduce a novel approach to pattern classification across multiple dimensions. Trans-dimensional learning is concerned with automatically determining network architectures that can generalize not only for fixed-dimensional problems but take a profound step by exemplifying how learning an unrestricted number of problems--which differ in the dimensionality of their input space N--can be accomplished. Relaxing the classification of network units as inputs hidden and outputs leads to the notion of all units of a network being features. Learning is perceived as the process of creating features and integrating these with other constructed features to form a self-adjusting network which can build on prior learned knowledge. This feat is accomplished by utilizing the simple perception rule for local feature training and incorporating evolutionary processes for determining suitable partitions to train individual features on. The basic algorithm introduced here (TDL) is augmented by single feature pruning to further reduce network complexity. An array of experiments is presented to emphasize the learning capabilities of TDL. |
8044376 | A quantitative study of pruning by optimal brain damage. | The optimal brain damage (OBD) scheme of Le Cun, Denker and Solla for pruning of feedforward networks has been implemented and applied to the contiguity classification problem. It is shown that OBD improves the learning curve (the test error as a function of the number of examples). By inspecting the architectures obtained through pruning, it is found that the networks with less parameters have the smallest test error in agreement with "Ockhams Razor". Based on this, we propose a heuristic which selects the smallest successful architecture among a group of pruned networks and we show that it leads to very efficient optimization of the architecture. The validity of the approximations involved in OBD are discussed and it is found that they are surprisingly accurate for the problem studied. |
8044375 | Neural net pruning based on functional behavior of neurons. | This paper proposes a new pruning method based on merging neurons with similar functional behavior which is defined by the internal representations of each neuron for the entire training set. Classification of neurons by their functional behavior with respect to the input vectors provides a powerful tool for pruning neurons and connections, thus reducing the network complexity and increasing its generalization capability. The most remarkable property of this pruning scheme is its ability to preserve net functionality by transferring the role of every removed neuron to the most fitted neuron of the surviving ones, using a unique merging and compensation procedure. The implementation of the proposed method is demonstrated using a detailed numerical example and its performance is examined by a statistical measure calculated by repeating the training procedure several times. The influence of parameter selection on pruning performance and generalization ability is discussed and demonstrated by examining statistical results. |
8044373 | A biologically motivated associative memory architecture. | A synthesis of analytical techniques from the fields of biology, mathematics, computer science and engineering are used to model the information processing characteristics of the mammalian cerebellar cortex. By viewing anatomically different neurons as representing network elements whose input-output functions are different, a mechanism for distributing information throughout the memory is proposed. The functional circuitry developed to implement this feature is called the microcircuit. Overlapping microcircuit activity is used to describe the memory's read and write operations. Key features of the memory model include: (1) its use of a sparse interconnection network, (2) its ability to manipulate very large input patterns, (3) its distributed storage of input data patterns and (4) its statistical reconstruction of stored patterns during memory read operations. Quantitative measures for the memory's recall fidelity and storage capacity are derived and results of computer simulations are presented. |
8044374 | Control of the complexity of associative memory dynamics by neuronal adaptation. | An abstract neural network model of the Hopfield type is extended to incorporate neuronal adaptation by defining the state of a neuron in terms of two variables, activity and excitability. The model is formulated to represent the regulation of the firing rate of action potentials in a biological system via the neuron cell membrane afterhyperpolarization by the effect of intracellular calcium ion concentration on the conductance of calcium sensitive potassium channels. It is shown that the complexity, and thus the exploratory degree, of associative memory dynamics are controlled by neuronal adaptability. At low adaptability, the dynamics have fixed point attractors corresponding to direct memory retrieval. In a subsequent region of adaptability values, a simple limit cycle persists with frequency increasing with adaptability. The range of frequencies agrees with that observed for theta rhythms of activity in the brain. A higher degree of freedom of the associative process corresponding to more complex dynamics, either limit cycles of varying complexity and period or chaotic behaviour, results at higher adaptability. In the brain, the neuronal adaptability is regulated by neuromodulators which suppress adaptation and increase absolute firing rates of action potentials. An associative process can be started at low concentration of neuromodulators as an exploratory search of state space during which firing rates are low. As the concentration of neuromodulators increases, the state space search becomes simpler cyclic and more restricted, and firing rates increase. Eventually, a particular stored state is retrieved and its activity is high. This correspondence between the complexity of associative memory dynamics and the concentration of neuromodulators is consistent with the observation for Alzheimer's disease of selective degeneracy of neurons releasing the neuromodulator acetylcholine. In an artificial neural network, inclusion of adaptation among neuronal properties allows control of the degree of freedom of associative processes and thus extends the range of possible applications. |
8044372 | Exploratory laparoscopy for perforation following colonoscopy. | Colonoscopy is being increasingly used for the diagnosis and therapy of colonic diseases. Bleeding and perforation are two major complications. The management of patients with perforation is undergoing evolution. There is evidence to support conservative management in selected patients with perforation without clinical signs of peritonitis. There is, however, a subset of patients with perforation where a considerable doubt exists about the choice between surgical and conservative management. We report one such patient, a 50-year-old woman with free air under the diaphragm and peritoneal signs following a therapeutic colonoscopy in whom an exploratory laparoscopy was performed. Exploratory laparoscopy is proposed for such patients when there is a question in choosing between surgical and conservative management. |
8044371 | Video-assisted Spigelian hernia repair. | Spigelian hernia is a rare hernia of the lateral abdominal wall. It is rarely incarcerated and sometimes difficult to diagnose because it is so small. This report describes an incarcerated Spigelian hernia that was successfully repaired using video-assisted laparoscopy, concurrent with a cholecystectomy. |
8044370 | Laparoscopy-guided drainage of hepatic abscess. | Hepatic abscess is a serious surgical condition with a mortality rate of up to 63% reported if not adequately treated. Laparotomy and computed tomographic (CT) guidance have been used to drain these collections, each with their own problems. Herein we describe a method of draining laparoscopically a hepatic abscess. A 45-year-old Haitian man presented with night sweats and fevers to 103 degrees F; he was diagnosed by CT to have a large (7 cm) abscess in the posterosuperior portion of the right hepatic lobe. The CT-guided drainage yielded only 8 cc fluid. The patient underwent laparoscopy-guided drainage of the abscess with placement of intra-hepatic and perihepatic drains. The patient had dramatic clinical improvement with no morbidity from the procedure. A follow-up CT of the abdomen revealed near-complete disappearance of the abscess cavity within 48 h. A straightforward method of laparoscopic drainage of hepatic abscesses is presented in detail. It provides a simple alternative for drainage with excellent results and minimal morbidity. |
8044369 | Acute fatty liver of pregnancy: laparoscopy-assisted diagnosis. | We report a case of fatty infiltration of the liver in a 27-year-old Hispanic woman. She went to an outside hospital in her third trimester of pregnancy with abdominal pain, jaundice, peripheral edema, and diffuse intravascular coagulation. An emergent cesarean section was performed, and she developed symptoms of acute hemorrhagic pancreatitis and altered mental status. She was transferred to Harbor County Hospital, where a computed tomography scan showed a fatty liver, and a liver biopsy confirmed the diagnosis of fatty liver of pregnancy. Prompt recognition and immediate termination of pregnancy with intensive, supportive care are essentials in the management of fatty liver of pregnancy. |
8044368 | Intraoperative diagnosis of choledochal cyst in preparation for laparoscopic cholecystectomy. | The initial description of abnormalities of the biliary tree was reported by Vater in 1723. However, it was not until 1959 that Alonzo-Lej and colleagues reported on the full description and classification of choledochal cysts. This report describes a Hispanic female who presented with classic findings consistent with biliary colic. A preoperative ultrasound revealed multiple gallstones and mild dilatation of the common bile duct. At the time of laparoscopy, she was found to have a dilated common bile duct, cystic duct, and gallbladder. Further dissection was discontinued, a cholecystectomy made, and a percutaneous transabdominal cholangiogram through the gallbladder performed, which revealed a type I choledochal cyst (cystic dilatation of the extrahepatic bile ducts). The patient then underwent resection of the extrahepatic biliary tree with a Roux-en-Y hepaticojejunostomy. Her subsequent postoperative course was uneventful. This case illustrates the role of cholangiography using the gallbladder as a conduit in the diagnosis of complex biliary tree anomalies during laparoscopy when the biliary tree cannot be safely accessed. |
8044367 | Video endoscopic surgery in the community hospital. | After proper training and observation, I started performing laparoscopic cholecystectomy at the community hospital in August 1990. Since then, and after further advanced training, I have performed 172 procedures, including appendectomy, hernia repair, lysis of adhesions, retroperitoneal biopsy, paraesophageal hernia repair, exploration of the common bile duct, repositioning of CAPD catheters, and colon resection with excellent results. This experience confirms that video endoscopic surgery can become the approach of choice in the community for many of what today are still considered open procedures, without undue risk, as long as adequate training is obtained and proper preparation observed when more advanced procedures are attempted. |
8044366 | Laparoscopic cholecystectomy: 563 cases at a community teaching hospital and a review of 12,201 cases in the literature. Monmouth Medical Center Laparoscopic Cholecystectomy Group. | Eleven surgeons attempted laparoscopic cholecystectomy in 563 patients over a 14-month period. Of these 563, 536 (95.3%) were performed successfully; the remaining patients required conversion to laparotomy, but only five because of complications. There were no mortalities associated with the procedure. Thirty-nine patients had complications, 14 surgical and related to the procedure itself. Weight was not considered a contraindication. The preoperative diagnosis in 83.6% patients with chronic cholecystitis, and in the remainder (16.4%) it was acute cholecystitis. Mean operative time was 86.4 min, and mean hospital stay for uncomplicated successful laparoscopic cholecystectomy was 1.9 days. An extensive review of the literature reveals an additional 9,792 laparoscopic cholecystectomies performed at the time of the writing of this paper. Our results compare favorably to these. A discussion of historical aspects of the procedure, contraindications to laparoscopic cholecystectomy, and the merits of selective intraoperative cholangiography are also presented. |
8044364 | Various stapling techniques in laparoscopic appendectomy: 40 consecutive cases. | The applicability and safety of a new operative technique for laparoscopic appendectomy using an automatic stapling device, the Multifire Endo-GIA 30, was evaluated. This instrument, which can be passed through a 12-mm trocar sleeve, compresses the appendix as well as the resting stump, occluding its lumen with three lines of titanium staples and cutting between them. Data from 40 laparoscopic appendectomy patients collected between August 1991 and March 1992 were analyzed prospectively. Using this stapler, the mean operation time was 58.33 min (range, 35-95 min), with no complications or mortality. In 35 cases, an acute, and in one case, a chronic, appendicitis was histologically confirmed; in four cases no inflammation was detected. Our preliminary results suggest that this new stapling device offers a simple and safe method for use in laparoscopic appendectomy. |
8044365 | Laparoscopic varicocelectomy. | We report our initial experience of laparoscopic ligation of varicocele in 13 patients with a mean age of 34 years (range 18-39). Eight patients were subfertile, and the rest complained of dragging pain and discomfort in the left scrotum. At laparoscopy the peritoneum overlying the spermatic vessels was divided, and the spermatic veins were mobilized, clipped, and divided. The spermatic artery was identified and preserved in 11 of the 13 cases. The patients were discharged within 24 h of hospital admission. Semen quality improved in seven of the eight subfertile patients studied with a mean follow-up of 8 months. Four patients who were operated on for pain and discomfort had symptomatic improvement by the time of their first outpatient visit at 3 months. One patient complained of paresthesia along the anterior aspect of his thigh, which resolved in 6 weeks. There were no other complications. Laparoscopic varicocelectomy is a safe and effective minimally invasive procedure for treatment of clinical varicocele. |
8044363 | Laparoscopic repair of recurrent groin hernias. | Between November 1991 and May 1993, 54 recurrent groin hernias were laparoscopically repaired in 50 patients. Forty-eight were men and two were women. Forty-six recurrent hernias were unilateral and four bilateral. Twenty-five were direct, 19 indirect, 10 pantaloon, and two had a femoral component. In only 10 patients was the contralateral side normal. In 27 patients, the other side had been previously repaired, and in 13 they had a new contralateral hernia. A transabdominal preperitoneal technique was used to dissect and repair the entire floor in all patients. A single sheet of polypropylene mesh was used in the repair of the women patients, and a double-buttress technique with the first sheet slitted for the cord was used for the men. Patients were examined every 3 months for the first year and at 6-month intervals thereafter. Follow-up ranged from 1 to 18 months with a mean of 8 months. No patient was lost to follow-up, and no recurrence was observed. Patients returned to normal activity in an average of 1 week. Seroma, which resolved spontaneously, was the most common complication. The overall short-term results suggested that a laparoscopic mesh buttressed repair of recurrent groin hernias is technically feasible and can eliminate early rerecurrence of the hernia so commonly seen after repair of recurrent hernias. |
8044362 | Gastric foveolar hyperplasia in patients with cancer of the intact stomach. | The incidence of gastric foveolar hyperplasia, a reliable histological marker of bile reflux into the stomach, was evaluated in patients with cancer of the intact stomach. Lesions classified as foveolar hyperplasia were found in 17 of 32 gastric cancer patients and in seven of 30 controls. This difference was statistically significant (p < 0.02). Differences in the incidence of foveolar hyperplasia according to sex, tumor site, attendant chronic atrophic gastritis, and alcohol consumption were not significant, which lends support to the association of gastric cancer with duodenogastric reflux. |
8044361 | Laparoscopic intracorporeal harvest of jejunal tissue for autologous transplantation. | Our goal in this study was to assess the feasibility and safety of performing an intracorporeal laparoscopic jejunal harvest. The initial technique was developed and refined in a pig and then a dog model. In the animal studies, careful dissection of the jejunal flap with its feeding vessel was accomplished along with an intracorporeal anastomosis. The laparoscopic dissection was facilitated by temporarily anchoring the jejunal flap to the anterior abdominal wall and transilluminating the mesentery. We present the first case report of a patient who underwent a laparoscopic jejunal harvest, intracorporeal small bowel anastomosis, and a microvascular anastomosis in the neck for reconstruction of the laryngopharynx. |
8044360 | Laparoscopic cholecystectomy: safe and feasible in emphysematous cholecystitis. | We report three cases of emphysematous cholecystitis managed by laparoscopic cholecystectomy. The diagnosis was made by ultrasound in all cases. Two patients developed postoperative infections. There were no fatalities. The mean postoperative stay was 6 days. In experienced hands, laparoscopic removal of the gallbladder in emphysematous cholecystitis is feasible with good results. |
8044359 | Efficacy and safety of thoracoscopy for diagnosis and treatment of intrathoracic disease: the University of Maryland experience. | Thoracoscopy has become an important tool in the diagnosis and management of intrathoracic disease. Between April 1991 and October 1992, 93 patients underwent thoracoscopy. Lung resection was performed on nineteen patients for diagnoses of interstitial lung disease and on seven patients for pulmonary nodules. Eleven patients underwent therapeutic lung resection for management of pneumothorax or air leaks. Sixteen patients underwent thoracoscopy for pleural disease. This was to diagnose mesothelioma (2), to lyse benign adhesions (2), to drain empyema (2), and to evacuate loculated pleural effusion (10) thoracoscopically. Nine patients underwent thoracoscopic staging for lung cancer. Thirteen patients underwent thoracoscopic staging for esophageal cancer as part of a prospective trial. Other indications for thoracoscopy included pericardiectomy (6), sympathectomy (2), and resection of mediastinal mass (4). Thoracoscopy is an excellent option for patients at high risk from standard thoracotomy and may allow procedures to be performed which would prevent the need for open thoracotomy, resulting in shorter hospital stay and less postoperative pain. |
8044358 | Extracorporeal lithotripsy associated with laparoscopic cholecystectomy: results of 60 patients. | Gallbladder extracorporeal lithotripsy was performed on 60 patients before laparoscopic cholecystectomy. Of the 44 cases with solitary stones (range, 17-45 mm; mean +/- SEM, 26.9 +/- 0.1 mm), satisfactory fragmentation was obtained in 77.2%. Of the 16 cases with multiple stones (range, 11-25 mm; mean +/- SEM, 14.9 +/- 0.7 mm), satisfactory fragmentation was obtained in 18.75%. Minimal adverse effects were observed both clinically and macroscopically during surgery. Upon histologic investigation, only two small gallbladder lesions could be attributed to extracorporeal lithotripsy. No changes in blood chemistry tests were recorded. When carried out with high performance equipment, extracorporeal lithotripsy appears to be an interesting procedure that permits an appreciable reduction in the number of parietal wall incisions that need to be widened, therefore simplifying laparoscopic cholecystectomy when dealing with large stones. |
8044357 | Role of intraoperative cholangiography during endoscopic cholecystectomy. | Six hundred sixty-nine German hospitals participated in a survey on the use of intraoperative cholangiography (IOC) in its relationship to common bile duct injuries. Of these, 174 surgical departments are presently practicing IOC, 30 routinely. Only 16 injuries to the bile duct occurred in the 6,328 patients who underwent surgery in those 30 units. Approximately 80% of these injuries were discovered during surgery because of IOC and were treated immediately. A significant difference was found between these rates and those reported by units that performed IOC selectively. Only 58% of bile duct injuries were discovered at the time of surgery in units performing selective cholangiography. In addition, it appears that IOC helps to avoid bile duct injuries; the 30 units that performed routine IOC were defined as "learners," as they had performed fewer LCs, and yet they had a significant lower bile duct injury rate than "experienced" centers that did not perform IOC routinely. |
8044356 | Diagnosis and management of bile leaks following laparoscopic cholecystectomy. | Laparoscopic cholecystectomy is now the standard of care for the elective management of gallstone disease. Recent studies have shown the morbidity of laparoscopic cholecystectomy to be similar to that of open cholecystectomy. Postoperative bile leaks have been recognized to be a troublesome problem following laparoscopic cholecystectomy. We present a retrospective review of 854 patients undergoing laparoscopic cholecystectomy at a single institution. Records were reviewed of all patients identified as having postoperative bile leaks. Between January 1990 and April 1991, we have cared for, or been referred, 15 patients with postlaparoscopic cholecystectomy bile leaks (9/854, 1.1% index patients and 6 referred). The location of bile leakage was determined to be the common bile duct (CBD) in two, cystic duct in five, and small accessory ducts located close to the gallbladder bed in the remaining eight. Most patients presented in the first week following laparoscopic cholecystectomy (mean 4.3 +/- 0.7 days, range 2-10) with worsening abdominal pain (13/13, 100%), nausea, and low-grade fever (mean 99.6 +/- 0.3 degrees F, range 96.8-102.2). Eleven of fifteen (66.7%) patients underwent technectium-99m imidodiacetic acid scanning (Tc-99m IDA) to determine the presence of a possible bile leak. All eleven scans were positive, indicating the presence of a bile leak. Thirteen patients underwent endoscopic cholangiography confirming the presence of biliary leakage (the remaining two patients underwent prompt laparotomy). Five patients were taken to the operating room for management of their leaks (two with common bile duct injuries, two cystic duct leaks, one accessory duct leak).(ABSTRACT TRUNCATED AT 250 WORDS) |
8044355 | Metabolic images from dynamic positron emission tomography studies. | A dynamic sequence of positron emission tomography (PET) images gives rise to the possibility of creating images of in vivo tissue metabolism. For this reason PET is potentially a valuable instrument in the study of human biology and medicine. The analysis of dynamic PET data to produce metabolic images is a challenging problem from a statistical point of view. For example, a typical data set arising in the study of cerebral glucose utilization has on the order of 30 time-binned images per cross-sectional slice of tissue under examination, each of dimension 128 x 128 pixels. Metabolic imaging requires that the time series at each pixel, known as the time activity curve (TAC), be analysed to produce an estimate of local metabolism. This paper describes a mixture analysis approach to the construction of such metabolic images. In the approach the TAC at a given pixel is expressed as a weighted sum of sub-TACs corresponding to homogeneous tissues represented at the pixel. Estimates of tissue metabolism at the pixel are then constructed as a weighted sum of the metabolism associated with the individual sub-TACs. The procedure is illustrated by application to a [F-18]-labelled deoxyglucose study in a patient with a brain tumour. The ability to map simultaneously a range of parameters related to the transport and biochemical transformation of the radio-tracer, demonstrates the potential power of dynamic PET. |
8044354 | Statistical methods in neuroimaging with particular application to emission tomography. | We review statistical methods being applied in four key areas connected with PET and SPECT neuroimaging: (i) image reconstruction (briefly); (ii) tracer-kinetic, or compartmental, modelling; (iii) inference from region-of-interest data; (iv) inference at the pixel or voxel level. Under the last heading, we pay particular attention to the analysis of data from serial scans. We conclude by identifying some topics for future statistical research. |
8044353 | Statistical models for PET and SPECT data. | This article outlines the statistical developments that have taken place in emission tomography during the past decade or so. We discuss the statistical aspects of the modelling of the projection data and define the additive Poisson regression model. This leads to the use of the method of maximum likelihood as a means of estimating the underlying isotope concentration within a given region of a patient's body, and to the use of the EM algorithm to compute the reconstruction. The need for the regulation of the maximum likelihood solution is tackled using Bayesian techniques. A number of algorithms for the computation of regularized solutions are outlined. The issue of parameter estimation is discussed and some open issues are mentioned. |
8044352 | Fisher's method of scoring in statistical image reconstruction: comparison of Jacobi and Gauss-Seidel iterative schemes. | Many algorithms for medical image reconstruction adopt versions of the expectation-maximization (EM) algorithm. In this approach, parameter estimates are obtained which maximize a complete data likelihood or penalized likelihood, in each iteration. Implicitly (and sometimes explicitly) penalized algorithms require smoothing of the current reconstruction in the image domain as part of their iteration scheme. In this paper, we discuss alternatives to EM which adapt Fisher's method of scoring (FS) and other methods for direct maximization of the incomplete data likelihood. Jacobi and Gauss-Seidel methods for non-linear optimization provide efficient algorithms applying FS in tomography. One approach uses smoothed projection data in its iterations. We investigate the convergence of Jacobi and Gauss-Seidel algorithms with clinical tomographic projection data. |
8044351 | Some computational and statistical tools for paired comparisons of digital images. | This article is a case-based review that introduces applied statisticians to a number of issues and methods that arise in clinical studies with paired digital images as outcomes. Single photon emission computed tomography (SPECT) is the imaging modality used in two examples. The first is a physical simulation of relevant clinical features of SPECT images using a customized head phantom scanned under different experimental conditions. The objective is to demonstrate and compare several current methods for image registration, i.e., image superimposition in some optimal manner to obtain a common frame of reference within which to make pixel-by-pixel comparisons. Image registration together with image normalization to correct for spurious differences in background activity levels enable quantification of differences in paired images. The physical simulation assesses quantification accuracy. The second example involves two SPECT images of the same brain tumour patient taken about two months apart. The objective here is to demonstrate several tools from morphological image analysis for image segmentation, i.e., separation of 'figure' and 'ground', and simple image regression to detect patterns of differences in time, again after registration and normalization. The clinical context of both examples helps to keep the review in practical focus and is a useful starting point for descriptions of many standard tools in applied medical image analysis. References to relevant literature are provided for readers wanting to study particular subjects in depth. As medical image analysis becomes more sophisticated, more cost-conscious and scrutinized more intensively, proper attention to the computational and statistical bases for practical conclusions become even more crucial. |
8044348 | Dipyridamole angina: a specific symptom of severe multivessel disease. | Several studies have indicated that ischemia induced by dipyridamole is frequently associated with angina or ischemic ST-segment depression and that it occurs mainly in patients with three-vessel disease, those with collateral vessels, or those with both. In order to analyze the diagnostic relationships among them, we studied 227 consecutive patients who underwent coronary angiography and dipyridamole-thallium scintigraphy. A perfusion defect was found in 134 patients. Of these, 88 patients (66%) showed no significant ECG modifications or angina; 46 (34%) had a transient ST-segment depression, which was associated with typical angina ('dipyridamole angina') in 12. These 12 patients had three-vessel disease with intercoronary collateral circulation. Among the 134 patients with coronary critical stenoses and a positive thallium-dipyridamole test, collateral vessels were detected in 91 (68%). Dipyridamole angina, occurring during a positive dipyridamole-thallium test, is usually a manifestation of severe coronary stenoses with collateral circulation. However, as a diagnostic symptom it is characterized by high specificity but low sensitivity. |
8044347 | Differential response of high-density lipoproteins to first-step lipid-lowering diet according to their initial level. | A lipid-lowering diet has been shown to lower total cholesterol but also high-density-lipoprotein (HDL) cholesterol. The effect of the first-step lipid-lowering diet (as suggested by the European Atherosclerosis Society) on HDL levels was studied in 129 Greek patients aged 52.7 +/- 9.8 years, of whom 78 were men and 51 women of similar ages. Total, HDL, and low-density-lipoprotein (LDL) cholesterol, and the total: HDL cholesterol and triglyceride ratio were assessed before and 3 months after the diet. Overall, total cholesterol decreased by 12% (P < 0.001), LDL by 15% (P < 0.001), HDL by 3% (NS), triglycerides by 12% (P < 0.01), and total: HDL cholesterol ratio by 11% (P < 0.001). A difference was found in the response to diet according to baseline HDL levels: in patients with HDL of 39 mg/dl or higher (group A), HDL decreased by 10% and the total: HDL cholesterol ratio by 3%, whereas in those with HDL lower than 39 mg/dl (group B) HDL increased by 17% and the total: HDL cholesterol ratio decreased by 22%. The difference between the groups was statistically significant (P < 0.001) for these two values as well as for triglycerides, but not for total cholesterol and LDL. No difference in the responses between men and women was found. This differential response to diet should be taken into account when planning treatment. Patients with baseline HDL levels higher than 39 mg/dl should probably be considered for early treatment not only by diet but by lipid-lowering-HDL-raising drugs as well. |
8044346 | Clinical significance of coronary flow reserve: effect of papaverine and exercise. | The clinical significance of coronary flow reserve (CFR) was evaluated after pharmacological (papaverine) and physiological (exercise) vasodilation in patients with coronary artery disease (CAD). CFR was determined using parametric imaging in 10 patients with normal coronary arteries (group 1) and in 10 with CAD (group 2). Contrast density and mean appearance time were measured (region of interest = 249 pixels) in the perfusion beds of the left circumflex and the left anterior descending coronary arteries at rest, 45 s after 10 mg intracoronary papaverine, and during supine bicycle exercise. CFR was calculated from coronary perfusion after papaverine divided by perfusion at rest and coronary perfusion during exercise divided by perfusion at rest. Perfusion zones in patients with CAD were subdivided into regions supplied by a non-stenosed (group 2a) and a stenosed (group 2b) coronary artery. In control patients, heart rate increased from 75 beats/min at rest to 125 beats/min during exercise, and in patients with CAD from 63 to 107 beats/min, respectively. Mean aortic pressure showed a significant increase during exercise in both groups. Mean pulmonary artery pressure increased significantly during exercise from 19 to 28 mmHg in control patients and from 22 to 42 mmHg in the CAD group (P < 0.001). Coronary driving pressure (mean aortic minus diastolic pulmonary artery pressure) tended to increase during exercise in the control group (from 90 to 101 mmHg, NS) and remained nearly unchanged in patients with CAD (from 92 to 94 mmHg, NS). In the control group, CFR was significantly higher during exercise than after papaverine (4.0 versus 3.5, respectively; P < 0.01). However, coronary resistance (coronary driving pressure divided by coronary flow index) was similar after papaverine and during exercise. In patients with CAD, papaverine-dependent CFR was significantly reduced in the perfusion zone of the stenosed (2.1) but not of the non-stenosed coronary artery (3.0). In contrast, CFR during exercise was significantly decreased in both perfusion zones (2.5 in non-stenosed arteries and 1.5 in stenosed vessels). In control patients, CFR is slightly but significantly larger during exercise than after papaverine because of the exercise-induced increase in coronary driving pressure. In contrast, CFR is smaller during exercise than after papaverine in patients with CAD, most probably as a result of secondary mechanisms such as exercise-induced narrowing of stenosed vessels or an increase in extravascular resistance. Thus, CFR based on papaverine appears to be of limited value for assessing the functional significance of a stenotic lesion. |
8044345 | Free cholesterol concentrations in the high-density lipoprotein subfraction-3 as a risk indicator in patients with angiographically documented coronary artery disease. | The pathophysiology of plasma lipoprotein metabolism has long been linked to coronary artery disease (CAD). The present study evaluated the association between plasma lipoprotein lipid and apolipoprotein (apo) components and CAD in a group of 80 consecutive Caucasian patients undergoing coronary angiography. Coronary cineangiography was carried out using the Judkins technique and the lesions quantified by calculating a coronary artery lesion score (CALS). Very low- and low-density lipoproteins (VLDL and LDL) were separated by ultracentrifugation, and high-density lipoprotein (HDL) and HDL subfraction-3 (HDL3) isolated by a differential precipitation procedure. Apo A-I, A-II, and B were assayed by endpoint laser nephelometry using specific antibodies. Total cholesterol, free cholesterol, and fatty acid concentrations were measured by gas-liquid chromatography, and lecithin: cholesterol acyltransferase (LCAT) activity by the decrease in the concentration of free cholesterol. On the basis of the presence of CAD, the 80 patients were divided into two groups: 52 (65%) with CAD (mean CALS = 7.8) and 28 (35%) without CAD (zero CALS). The lipoprotein fraction that most clearly differentiated the groups was HDL cholesterol concentration, with a mean +/- SEM value of 36.5 +/- 1.5 mg/dl for those with CAD and 45.1 +/- 2.1 mg/dl for those without (P < 0.01). The mean HDL3 cholesterol concentration was 29.9 +/- 1.2 mg/dl for patients with CAD and 37.4 +/- 1.8 mg/dl for those without (P < 0.001). These differences in HDL cholesterol and HDL3 cholesterol were mainly caused by differences in the free cholesterol component, with a mean HDL free cholesterol level of 10.8 +/- 1.1 and 16.1 +/- 1.4 mg/dl (P < 0.01), and a mean HDL3 free cholesterol level of 7.6 +/- 0.6 and 11.9 +/- 0.8 mg/dl (P < 0.001) in patients with and without CAD, respectively. Plasma LCAT activity was decreased in patients with CAD (P < 0.05), as were the apo A-I and A-II concentrations in both the HDL (P < 0.001) and HDL3 (P < 0.001) fractions. No significant association was found between CAD and HDL2 cholesterol or plasma total cholesterol, LDL cholesterol, or VLDL cholesterol concentrations. A stepwise discriminant analysis revealed that HDL3 free cholesterol was the only variable selected. Using HDL3 free cholesterol as a screening variable for CAD (cutoff 10.55 mg/dl), the sensitivity for CAD was 87% and the specificity for non-CAD 67%. The positive and negative predictive values of HDL3 free cholesterol were 82 and 75%, respectively. We have shown that the concentrations of HDL cholesterol and HDL3 most clearly differentiated between patients with and without CAD. |
8044344 | Facilitation of coronary spasm by propranolol in Prinzmetal's angina: fact or unproven extrapolation? | Alpha-adrenergic activation enhances coronary vascular tone; beta-blockade leaves alpha-adrenergic vasoconstriction unopposed. Whether beta-adrenergic blockade facilitates coronary spasm in patients with Prinzmetal's angina is unknown. Using quantitative angiography, we evaluated the response of normal and narrowed coronary arteries to intravenous propranolol, a cold pressor test (an alpha-stimulus), and the combination of the two in 15 patients with Prinzmetal's (group 1) and in 19 with classic (group 2) angina. From measurements of heart rate, systemic and pulmonary arterial pressures, and left and right ventricular ejection times, we derived the tension-time index per minute as a measure of the oxygen need (O2 demand) of the whole heart. In group 1, cold invariably constricted normal and diseased vessels, and in two patients elicited spasm at sites of significant lesions; these changes did not correlate with those in O2 demand. In group 2, the vasomotor reaction of normal and narrowed vessels in response to cold correlated with the modifications in O2 demand. After propranolol administration, (1) in normal vessels in both groups, the baseline luminal diameter varied in parallel with the changes in myocardial O2 demand; (2) narrowings in group 1 patients invariably dilated and in group 2 the caliber varied according to changes in O2 demand; (3) during cold stimulation, luminal narrowing in group 1 varied in parallel with O2 demand, and, in group 2, vessels were uniformly constricted. These results do not support the facilitation of coronary spasm by propranolol in Prinzmetal's angina and support the hypothesis that the contractility of coronary vessels in patients with this form of angina is different from that in the classic form. |
8044337 | Botulinum A toxin therapy in ophthalmology: a report of patients with facial dystonias. | An overview is given of the indications, results and complications with the use of botulinum A toxin injection therapy specifically in the treatment of facial dystonias. A total of 79 patients have been treated over a 5-year period. The patients were divided in four groups: essential blepharospasm, hemifacial spasm, apraxia of the opening of the eyes and spastic entropion. On average, the therapeutical effect started the third day after injection. The average duration of the beneficial effect was dependent of the underlying pathology. Local side effects were mild and systemic side effects were not seen. Botulinum A toxin therapy proved to have a reliable and reproducible effect in appropriate dosages, in 90% of the patients. |
8044334 | A rare case of chronic papillary conjunctivitis diagnosed after several years of evolution. Clinical and pathological findings. | A man with a 2.5 year history of chronic papillary conjunctivitis was diagnosed as having "floppy eyelid syndrome". This syndrome, first described in 1981, is characterized by loose upper eyelids that evert readily on elevation of the lid, a chronic papillary conjunctivitis and a soft rubbery tarsus. The condition is resistant to any form of medical treatment but responds well to a horizontal lid shortening procedure. The etiology is unknown but the present report suggests that an abnormality of the structure of the orbicularis muscle may play a role. |
8044336 | Natural history and visual outcome in patients with APMPPE. | We undertook a retrospective study of the files of 21 patients (42 affected eyes) with acute posterior multifocal placoid pigment epitheliopathy to obtain details on the natural history of the disease and on the functional and visual outcome (mean follow up: 17 months). The final visual acuities were 8/10 or better in 34 eyes (81.0%), 7/10 to 2/10 in 6 eyes (14.2%) and 1/10 in two eyes (4.8%). Although the final visual acuity was good in most eyes, 24 eyes (57.2%) were still symptomatic due to scotomas (33.3%), metamorphosia (21.4%), decreased vision (16.6%), floaters (4.8%) and chronic redness (2.4%). Recurrences did not occur in this group of patients. Electrophysiological and color vision tests were performed in the initial phase of the disease, but we found no correlation between the test results and the final visual acuity. |
8044335 | Peribulbar regional anaesthesia for anterior eye segment surgery. | The technique, the results and the complications for local peribulbar anaesthesia for anterior eye segment surgery are discussed. A personal series of 3,350 cases is analysed. The rare local complications could have been avoided by improving the technique. There were no general complications. |
8044333 | Diagnosis and differential diagnosis of malignant melanomas of the choroid. | A complete ocular examination is essential for the correct diagnosis of a malignant melanoma of the choroid. The single, most important technique is indirect ophthalmoscopy associated with biomicroscopy of the fundus. Fluorescein angiography may provide additional arguments for malignancy, but with this method it is not always possible to differentiate a malignant melanoma from a suspected naevus or even a choroidal metastasis. Fluorescein angiography provides however a detailed and objective document which allows a better follow-up of suspected lesions. As with infrared angiography, choroidal vessels are more readily seen, this technique may prove to be of diagnostic importance. A- and B-scan ultrasonography are essential to precisely measure a choroidal lesion. Especially A-scan may also allow tissue differentiation. Diaphanoscopy is especially useful in the diagnosis of choroidal haemangioma. Even naevi may provide relative or absolute scotomas. The diagnostic importance of perimetry is therefore very limited. CT-scan and especially MRI are helpful in detecting extra-ocular extension. In case of atypical naevi, a close observation for potential growth is advised. Malignant melanomas of the choroid have to be differentiated from other fundus tumours, but also from inflammatory and degenerative conditions. |
8044331 | The value of medical imaging techniques in the diagnosis of extra-ocular extension of malign melanoma of the choroid: a case report. | The major goal in the evaluation of posterior uveal tumours is to determine whether an intra-ocular malignancy is present and whether intervention is necessary. Small uveal pigmented tumours can safely be managed by observation until growth is documented. However, extensive evaluation for each suspicious lesion is necessary in order not to miss any signs of malignancy. A case is presented of a 41 year old male patient with orbital pain as initial symptom of a choroidal melanoma. Fluorescein-angiography revealed signs of double circulation. Abnormal choroidal vessels inside the tumour showed up clearly on indocyanine-green angiography. By ultrasonography we were able to detect scleral perforation and extra-scleral extension. Computed tomography confirmed the extra-scleral extension. As there were no signs of metastasis, an orbital exenteration with sparing of the eyelids was performed. Histopathology is compared with the results of clinical investigation. |
8044330 | [The value of MRI in a difficult diagnosis of melanoma of the choroid]. | The authors present a clinical case of a young woman presenting a non typical melanoma with optic disc oedema. The results of the different examinations are presented and the importance of an N.M.R. is stressed. The differential diagnosis is discussed. |