bluuebunny/crossref_metadata_2025 huggingface dataset:
Clustered Phylogenetic Distribution of Nucleus rostrolateralis among Ray-Finned Fishes
Authors: Butler Ann B. , Saidel William M.
Published: September 2003

Nucleus rostrolateralis, which was named for its location in the rostrolateral part of the diencephalon of neopterygian fishes, has been identified in a variety of species based on position, cytoarchitecture, hodology, and/or histochemistry. The phylogenetic distribution of the nucleus is highly sporadic, however. Due to this distribution, nucleus rostrolateralis cannot be regarded as phylogenetically homologous, but it might be an example of syngeny, or generative homology, which applies to characters that have the same genetic and/or developmental basis inherited from a common ancestor, whether or not the character itself has a phylogenetic distribution congruent with a monophyletic taxon – i.e., in general terms, an example of either phylogenetic homology or parallelism. To test whether the nucleus occurs in closely related taxonomic clusters, as might be expected for a character with a shared generative basis, a number of species of cyprinids and atherinomorphs (both teleost taxa) were examined for its presence. Many of the species examined appear to lack the nucleus, but a clustered occurrence of it was found within both taxa. Within cyprinids, nucleus rostrolateralis occurs in all three members examined of the Subfamily Rasborinae. Within atherinomorphs, it occurs in both members examined of the Tribe Poeciliini (of the Subfamily Poeciliinae, Family Poeciliidae) and in the one member examined of the Family Anablepidae. The clustered occurrence of nucleus rostrolateralis supports the hypothesis that it is an example of syngeny. Its postulated shared generative basis appears to derive from the common ancestor of the entire neopterygian radiation despite the rare occurrence of the character itself.
Phenomenology of Delusions in Pakistani Patients: Effect of Gender and Social Class
Authors: Suhail Kausar
Published: September 2003

The present study aimed to assess the actual content of delusions of Pakistani schizophrenic patients by gender and social class. A total of 98 schizophrenic patients (48 men and 50 women) from the two psychiatric units in Lahore, Pakistan, were interviewed using the Present State Examination categories. When the sample was analysed as a whole, the delusion of persecution was found to be the most common one followed by the delusion of grandiose identity. When the sample was divided according to gender and social class, two subgroups with surprisingly similar themes of delusions emerged from the analysis, one male and wealthy and the other female and poor. The themes of having special powers and being a star were more frequently found among the former, whereas the themes of black magic, persecution, being controlled and erotomania appeared to be more conspicuous among the latter. The results indicated that the phenomenology of delusions differs in subgroups of the population depending on their socio-cultural roles and specific vulnerabilities.
Dissociative Symptoms in Pathological Gambling
Authors: Grant Jon E. , Kim Suck Won
Published: September 2003

Background: Dissociation is increasingly being recognized as both a normal process and as a psychophysiological aspect of a number of mental disorders. The purpose of this investigation was to shed light on a possible link between dissociation and pathological gambling, a relatively common disorder whose phenomenology remains understudied. Sampling and Methods: Thirty adult outpatients who met DSM-IV criteria for pathological gambling and had no comorbidity were administered the Dissociative Experiences Scale (DES). Results: The pathological gamblers had DES scores that did not significantly differ from those reported by normal controls (t = –0.620; d.f. = 29; p = 0.540). Conclusions: Pathological gamblers do not appear to experience dissociative symptoms (as reflected on the DES) at a rate significantly different from those found in normal controls. Because pathological gamblers seeking medication treatment, as in this study, may differ from others with pathological gambling, further studies are needed.
Gender Differences in Severity, Symptomatology and Distribution of Melancholia in Major Depression
Authors: Hildebrandt Malene Grubbe , Stage Kurt Bjerregaard , Kragh-Soerensen Per
Published: September 2003

Background: Studies of gender differences in the clinical presentation of depression have provided divergent results. This study aimed at analyzing gender differences in severity, symptomatology and distribution of melancholia in major depression. Sampling and Methods: The study comprised 930 in- and out-patients (652 women, 278 men) from 6 randomized controlled trials. All patients fulfilled DSM-III or DSM-III-R criteria for major depression. The 17-item Hamilton Depression Scale (HDS) was applied to all patients. A multi-axial evaluation was completed using the Newcastle 1 Depression Rating Scale from 1965 for melancholia (N1) in a subsample of patients (n = 439). A factor analysis on the HDS was performed. Non-parametric statistical tests were used and only gender differences greater than 20% were considered clinically relevant. Results: The median on the HDS total score was 22 and the median number of symptoms was 13 for both men and women. Presentation of specific symptoms was similar for men and women. The factor analysis revealed no gender differences, and neither did analyses on symptoms of Axes II and IV. According to the N1, 80% of the men and 66% of the women suffered from melancholic depression (p = 0.004). Conclusions: In a large and broad sample of in- and out-patients with major depression, the severity and symptomatology of depression were similar for men and women. Melancholic depression was significantly more frequent among male than female patients. Inclusion and exclusion criteria in the randomized controlled trials provided a selected group of patients, which limited the generalisability of the results to an exclusive subgroup of patients treated for depression in routine clinical practice.
Delusional Paralysis: An Unusual Variant of Cotard’s Syndrome
Authors: Reif Andreas , Murach Waldemar M. , Pfuhlmann Bruno
Published: September 2003

Cotard’s syndrome, a highly impressive psychopathological condition, occurs mainly in depressive disorders and entails nihilistic delusions concerning the body and the non-existing of the self as outstanding features, accompanied by hypochondriacal delusions and ideas of guilt as well as immortality. We here report on a female patient presenting with an unusual variant of the syndrome: most prominently, she had the delusion to be paralysed, although displaying psychomotor agitation, and that neuroleptic agents had devoured her nerve ganglia. Upon ECT, symptoms rapidly improved. Psychopathological implications and the nosological position of Cotard’s syndrome are discussed.
Pitx1 in vivo Promoter Activity and Mechanisms of Positive Autoregulation
Authors: Goodyer Cynthia G. , Tremblay Jacques J. , Paradis François W. , Marcil Alexandre , Lanctôt Christian , Gauthier Yves , Drouin Jacques
Published: September 2003

During early mouse embryogenesis, Pitx1 (pituitary homeobox 1), a member of the bicoid subgroup of paired homeobox-containing transcription factors, marks the stomodeum, oral ectoderm, pituitary and first branchial arch in the anterior part of the embryo and lateral plate mesoderm only in the posterior half of the embryo. We have now defined Pitx1 promoter fragments that mimic the anterior but not posterior expression of Pitx1 in transgenic mice. In addition, we show positive regulation of this promoter in transfection studies by three members of the Pitx1 family (Pitx1, Pitx1b, Pitx2), as well as by a related factor, Otx1. Pitx1 autoregulation depends on DNA-binding and trans-activation domains of Pitx1 and it may be responsible for establishment and/or maintenance of the Pitx1 expression domain.
Effect of Adrenalectomy on Mating-Induced Prolactin Surges and Pseudopregnancy in the Female Rat
Authors: Cameron Nicole , Ha Grace K. , Erskine Mary S.
Published: September 2003

In the estrous female rat, mating stimulation induces an acute surge of prolactin (PRL) within 20 min after mating followed by the onset of twice-daily PRL surges which persist for an 8- to 13-day period of acyclicity called pseudopregnancy. In Experiment 1, we examined whether the release of adrenal hormones after mating modulates mating-induced PRL secretion during the first 38 h after mating. Ovariectomized females were adrenalectomized (Adx) or sham-operated (Sham) and were implanted with jugular vein catheters 2 days later. They were given estrogen and progesterone and mated 6 days after the last surgery until they received 15 intromissions or 15 mounts-without-intromission from a male. Blood samples were collected beginning 20 min before mating at 23:00 h and continuing for 38 h. Plasma PRL concentrations were measured using radioimmunoassay. Mating that included intromissions induced an acute (20-min) PRL response which was higher in Adx than in Sham animals, and advanced in the Adx animals in the onset of the first daily PRL surge to 10:00 h, some 18 h before the surge was observed at 04:00 h in the Sham-mated animals. A small but measurable nocturnal surge was observed in Adx and Sham groups 18–24 h later at 04:00–10:00 h. In Experiment 2, Adx- and Sham-cycling animals received 5 (5I) or 7 (7I) intromissions from a male 12–16 days after surgery. Adx animals receiving 5I showed a significantly higher incidence of pregnancy or pseudopregnancy (%P/PSP) than did Sham 5I animals, while there was no difference in %P/PSP in the 7I groups. We conclude that adrenal gland secretions normally suppress plasma PRL concentrations immediately post-mating and before the onset of the nocturnal mating-induced PRL surge and also inhibit pseudopregnancy when females receive a subthreshold number of intromissions normally required for its induction.
Perceptual Categorization Is Impaired in Huntington’s Disease: An Electrophysiological Study
Authors: Antal Andrea , Beniczky Sándor , Kincses Tamás Z. , Jakab Katalin , Benedek György , Vécsei László
Published: September 2003

Recent evidence raised the possibility that the neostriatum and the corticostriatal circuits could play an important role in semantic categorization. In this study, we examined the electrophysiological correlates of natural scene categorization in Huntington’s disease (HD) patients and their asymptomatic relatives who were Huntington’s disease mutation carriers (HDC). Event-related potentials were recorded in HD patients, HDC subjects, and age-matched control subjects using a natural scene categorization task. The subjects had to decide whether a briefly presented image contained animals or no animals. Concerning the N1 component (150–250 ms), the mean amplitudes were more negative for nonanimal scenes as compared with stimuli containing animals at all electrode sites in the control group and at all but the lateral temporal electrode sites (T3, T4) in the HD group. Between-group comparison demonstrated that the N1 amplitudes were significantly smaller for both kinds of stimuli in the HD group in spite of a normal primary occipital component (P100). The HDC subjects were not significantly different from the controls concerning the N1 amplitudes. These results suggest that perceptual (N1) processes related to the categorization of natural scenes are specifically impaired in HD. The findings are in agreement with the hypothesis emphasizing the importance of neostriatal mechanisms in human categorization functions.
The Rapid Dementia Screening Test (RDST): A New Economical Tool for Detecting Possible Patients with Dementia
Authors: Kalbe Elke , Calabrese Pasquale , Schwalen Susanne , Kessler Josef
Published: September 2003

The Rapid Dementia Screening Test (RDST) is a new psychometric screening tool to support the diagnosis of dementia. It includes two parts – a word generation task and a number transcoding task; it is short (taking approximately 3 min) and easy to administer, and it is well accepted by patients. After transformation of the raw scores in two age groups (under and over 60 years), the assessed cognitive abilities can be interpreted as age-appropriate or below average with good sensitivity and specificity, and subsequent diagnostic measures can be determined accordingly. The RDST is thus an economical tool for detecting demented patients by general practitioners.
Decreased Cerebrospinal Fluid Acetylcholinesterase in Patients with Subcortical Ischemic Vascular Dementia
Authors: Wallin Anders , Sjögren Magnus , Blennow Kaj , Davidsson Pia
Published: September 2003

The main objective was to investigate the acetylcholinesterase E (AChE) activity in the cerebrospinal fluid (CSF) of patients with three common dementia disorders. We also wanted to investigate the influence of apolipoprotein E (ApoE) Ε4 allele possession and CSF-τ level on the CSF-AChE activity in these patients. The study included 17 consecutive patients with subcortical vascular dementia (SVD), 39 with Alzheimer’s disease (AD), 14 with frontotemporal dementia (FTD) and 12 controls. CSF was obtained by lumbar puncture and CSF-AChE activity was measured by an enzyme antigen immunoassay. CSF-AchE activity was significantly decreased compared to controls only in the SVD group (p = 0.010). The CSF-τ level was increased in the AD group compared to the control (p < 0.01) and FTD groups (p < 0.05). No influence of ApoE Ε4 allele possession on CSF-AChE activity was found. It is suggested that abnormal CSF-AChE activity in patients with SVD reflects a disturbance in the cholinergic system.
Apolipoprotein E in Taiwan Chinese Patients with Dementia
Authors: Lai C.L. , Tai C.T. , Lin S.R. , Lin R.T. , Yang Y.H. , Liu C.K.
Published: September 2003

To clarify whether Alzheimer’s disease (AD) and vascular dementia (VaD) share the same risk factors in Taiwan Chinese patients. Using the criteria of the NINCDS- ADRDA and NINDS-AIREN, 154 AD patients, 30 VaD patients, and 112 controls were enrolled. Their apolipoprotein E (ApoE) genes, extracted from peripheral blood leukocytes, were analyzed. The Ε4 allele frequency was significantly higher in AD patients than in the control group. The odds ratio of carrying at least one copy of the Ε4 allele in AD patients is 2.7 compared with control subjects. There was no significant difference between the VaD patients and the control subjects in their ApoE Ε4 or Ε2 allele frequency. The present study demonstrates a strong association between the ApoE Ε4 allele and AD, but not between the ApoE Ε4 allele and VaD. This suggests that AD and VaD do not share the same pathogenesis and deserve further investigation.
Selective Hypoperfusion of Anterior Cingulate Gyrus in Depressed AD Patients: A Brain SPECT Finding by Statistical Parametric Mapping
Authors: Liao Yi-Chu , Liu Ren-Shyan , Lee Yi-Chung , Sun Chen-Ming , Liu Chia-Yih , Wang Po-Shan , Wang Pei-Ning , Liu Hsiu-Chih
Published: September 2003

This study tests the hypothesis that depression in patients with Alzheimer’s disease (AD) is due to a specific pathogenesis rather than a reactive phenomenon. Forty-three AD patients received a psychiatrist’s interview, neuropsychological assessments, and a 99mTc-hexamethyl propyleneamine oxime single photon emission computed tomography (HMPAO-SPECT). Analysis by statistical parametric mapping (SPM) showed that the depressed group had selective hypoperfusion in the bilateral anterior and posterior cingulate gyri and precuneus. Using the Hamilton Depression Rating Scale as a parameter, an inverse correlation was found between cerebral perfusion and the severity of depression. The right anterior cingulate gyrus demonstrated a most significant reduction in perfusion. These locations are akin to the imaging findings in patients with primary depression, indicating a specific pathogenesis for depression in AD.
The Clock-Drawing Test in Elderly Italian Community Dwellers: Associations with Sociodemographic Status and Risk Factors for Vascular Cognitive Impairment
Authors: Ravaglia G. , Forti P. , Maioli F. , Arnone G. , Pantieri G. , Cocci C. , Nativio V. , Muscari A. , Pedone V. , Mariani E.
Published: September 2003

To evaluate whether performance in the clock-drawing test (CDT) is associated with sociodemographic status and risk factors for cognitive impairment, we examined 744 Italian community dwellers aged ≧65 (73 ± 6) years scoring ≧24 on the MMSE. CDT was scored by two different methods, the Sunderland and the Wolf-Klein methods. Sociodemographic, lifestyle, clinical and biochemical variables were also recorded. For both scoring methods, lower CDT scores were associated with age, poor education, increased serum C-reactive protein and history of cancer. Associations of lower CDT scores with increased serum glucose and history of cerebrovascular disease were also found for the method with the highest sensitivity to cognitive impairment. This study shows that in elderly community dwellers, CDT may be not totally free from sociodemographic biases, and that it is associated with risk factors for cognitive impairment and frailty.
Intraorbital Encephalocele: An Important Complication of Orbital Roof Fractures in Pediatric Patients
Authors: Cayli Suleyman R. , Kocak Ayhan , Alkan Alpay , Kutlu Ramazan , Tekiner Ayhan , Ates Ozkan , Sahinbeyoglu Baran
Published: September 2003

Orbital roof fractures are uncommon, and traumatic intraorbital encephalocele formation is a very rare complication of this type of injury. We treated 43 pediatric patients with orbital roof fractures at our center over a 4-year period. The aim of this study was to retrospectively investigate conditions that may lead to intraorbital encephalocele formation in children with orbital roof fractures. Each case was reviewed, and the cause of injury, associated clinical and computerized tomography findings, the Glasgow Coma Scale score on admission, neurological status, other bodily injuries, hospitalization time and type and width of the orbital roof fracture were recorded. The findings in 6 patients who developed encephaloceles were compared to corresponding findings in the 37 patients who did not develop this complication. A total of 44 orbital roof fractures were diagnosed by axial and coronal computed tomography scanning. Six of the 43 children developed intraorbital encephaloceles in the first month after head trauma. In each of these cases, magnetic resonance imaging demonstrated the intraorbital cystic lesion in communication with the subarachnoid space. The width of each orbital roof fracture was measured on axial and coronal computed tomography slices and was confirmed by measurements during surgery. The width of the fractures in the encephalocele cases ranged from 2–4 mm. Duraplasty and orbitoplasty were performed in all the patients with encephalocele. Pediatric patients with orbital roof fractures that exhibit more than 2 mm diastasis and are associated with frontal cerebral contusion may be at greater risk for developing intraorbital encephalocele. All such cases should be monitored closely and investigated further with magnetic resonance imaging.
A Single-Pass Tunneling Technique for CSF Shunting Procedures
Authors: Sandquist Michael A. , Selden Nathan R.
Published: September 2003

Implantation of ventriculoperitoneal shunts in the precoronal position is generally accomplished using a retroauricular incision for subcutaneous tunneling. Retroauricular incisions can be associated with complications, including cerebrospinal fluid leak and shunt infection. We describe a technique for ‘single-pass’ shunt tunneling from frontal to abdominal incisions and our initial results in a consecutive, prospective series of 15 children (age 2 days to 5 years). Eleven patients presented with congenital hydrocephalus (including 5 with myelomeningocele and 3 with posthemorrhagic hydrocephalus) and 4 with hydrocephalus secondary to central nervous system (CNS) tumors. The average length of clinical follow-up was 6 months (range 1–13 months). There were no perioperative or long-term complications of the single-pass technique. Nine of the 11 patients with congenital hydrocephalus are currently well without any further medical or surgical intervention. Two underwent shunt revision for proximal obstruction, with an intact distal system. Three of the 4 patients with hydrocephalus secondary to CNS tumor suffered secondary shunt complications during periods of severe neutropenia resulting from chemotherapy (6 weeks to 6 months after shunt insertion). For primary ventriculoperitoneal shunt insertion in infants and young children, the single-pass tunneling technique is safe and avoids one source of complications.
Trait Characteristic of Impaired Visuomotor Integration during Trail-Making Test B Performance in Schizophrenia
Authors: Wölwer Wolfgang , Falkai Peter , Streit Marcus , Gaebel Wolfgang
Published: September 2003

Using concurrent recording of eye and hand movements during the performance of the Trail-Making Test B (TMT-B), Wölwer and Gaebel have recently reported impaired visuomotor integration in patients with acute schizophrenia, which mainly accounted for patients’ poor test performance. In order to replicate these exploratory findings in an independent sample of patients and to further investigate their stability during different stages of the illness, the performance process during a computerized TMT-B was assessed in 22 remitted outpatients with schizophrenia, 12 unaffected first-degree relatives and 26 healthy controls. As an estimate of longitudinal stability, a partial sample of 12 patients and 19 controls was reassessed after a period of 3 months. Remitted schizophrenia patients showed exactly the same strategic problems during the performance process of TMT-B as previously found in acute patients. Compared with healthy controls, patients more often sequenced searching (‘planning’) and connecting targets instead of time-sparing parallel execution, and their planning periods contained more and longer planning fixations (i.e. fixations outside the cursor area), which was related to longer performance time. Unaffected relatives mostly scored between patients and healthy controls without statistically significant differences to either group. Thus, the abnormalities in the process of TMT-B performance proved to be reliable and stable trait characteristics in schizophrenia.
Auditory-Evoked Potentials and Selective Attention: Different Ways of Information Processing in Cannabis Users and Controls
Authors: Kempel P. , Lampe K. , Parnefjord R. , Hennig J. , Kunert H.J.
Published: September 2003

The present study tested the hypothesis that chronic cannabis use leads to persistent attentional dysfunctions and that age of onset of cannabis use is a potential predictor of impaired test performance and information processing. Brain event-related potentials (ERPs) during a complex auditory selective attention task were recorded from 21 cannabis users divided into two groups according to age of onset and from 13 controls comparable with respect to age, IQ and educational background. Participants were instructed to detect target tones of a particular location, pitch and duration from a total sample of random frequencies. The study reveals that the latency of the greatest negative peak of ERPs (200 and 300 ms) to target tones was shorter in controls, while there was no clear difference between target and non-target within cannabis users. In addition, users displayed a reduced P3 to target tones. This was more pronounced in early-onset cannabis users. These data suggest that chronic cannabis use relates to different types of information processing under conditions of selective attention. There is some evidence that users employed different strategies of attention allocation. The results are discussed with respect to possible underlying mechanisms and clinical implications.
Functional Specialization in the Human Frontal Cortex Observed during Task Anticipation
Authors: Tarkka Ina M. , Mnatsakanian Elena V.
Published: September 2003

The purpose was to evaluate whether a scalp-recorded slow potential will show specificity during the anticipation of different types of visual tasks. One of the tasks required the comparison of pairs of familiar faces, and the other was the comparison of abstract dotted patterns. Each trial began with one of the two cues (S1) followed by consecutive pictures (S2 and S3). Faces and patterns were superimposed, and the switching between tasks depended on the cue. The ERP analysis was done for the time window between S1 (cue) and S2 presentations. The major differences between tasks were found in the anterior scalp regions starting at 700 ms from S1 onset. During Pattern task anticipation, the proposed sources in the right frontal area were more anterior, inferior and lateral than those in Face task. The task-specific slow electric potentials may indicate the functional specialization for attentive anticipation in the human frontal lobe.
Effects of Training on the Tolerance to High-Intensity Exercise in Patients with Severe COPD
Authors: Puente-Maestu Luis , SantaCruz Antonio , Vargas Teresa , Martínez-Abad Yolanda , Whipp Brian J.
Published: September 2003

Background: There has been no systemic investigation of the effects of training on endurance at different high-intensity work rates in patients with COPD to date. Objectives: We wanted to determine the effects of intense endurance training on tolerance to several high-intensity work rates and to establish the relationship between power (WR) and its tolerable duration (t) (t = W’/(WR – CP), being W’, the curvature constant, thought to be reflective of anaerobic energy availability and/or tolerance to the uncomfortable sensations associated with the high-intensity exercise, and CP the critical power. Methods: We studied 27 patients: age 62 ± 5 years; FEV1 1.2 ± 0.2 liters. Before and after the intervention, the subjects randomly underwent 4 high-intensity constant WR exercise tests. The endurance times of the highest 3 tests were used. Results: Ventilation reached approximately the same level in each of the tests. In response to the training, the average peak increased by 9 ± 5% (p < 0.0001), CP by 14 ± 12% (p < 0.0001) and W’ 18 ± 22% (p = 0.002). In 67% of the patients, CP increased, accompanied by changes in other related physiological variables of aerobic capacity. In the remaining 33%, W’ increased but not CP. Smaller or no changes in the other variables of aerobic capacity were found in those subjects. This latter group was significantly older and had more hyperinflation (i.e. higher RV/TLC%). Conclusions: Our results suggest that neither an incremental nor a single endurance test at constant WR provides an adequate characterisation of exercise tolerance at other WRs. CP and W’ appear to be important parameters characterizing exercise tolerance over a range high-intensity work rates and identifying two distinct types of response to training.
Postinfectious Bronchiolitis obliterans in Children: Clinical and Radiological Profile and Prognostic Factors
Authors: Yalçın Ebru , Doğru Deniz , Haliloğlu Mithat , Özçelik Uğur , Kiper Nural , Göçmen Ayhan
Published: September 2003

Background: Postinfectious bronchiolitis obliterans (BO) designates a clinical syndrome of chronic airflow obstruction associated with inflammatory changes in the small airways. Objectives: The aim of this study was to determine the etiology, clinical and radiological features and define prognostic factors of postinfectious BO in children. Methods: We undertook a review of the medical records of 20 children with postinfectious BO, who were followed up between January 1994 and August 2001. Results: Postinfectious BO was diagnosed in 11 boys and 9 girls with a median age of 21.5 months (6–69 months) who were followed up for a median of 23 months. Cough and wheezing persisted since the initial lung infection in all patients. Postinfectious BO was diagnosed in an average of 6 months (1–42 months) after the acute illness. Adenoviruses were the most common etiologic agents identified serologically. The diagnoses of postinfectious BO was made by thoracic high-resolution computed tomography and clinical features. Corticosteroid therapy was used in 17 patients and supportive treatment was applied in all patients. Age at initial lung infection, gender, time of starting corticosteroid treatment, presence of bronchiectasis or atelectasis and etiologic agents identified on presentation did not predict severity in our study. Conclusions: Despite the prominent role of inflammation in the pathogenesis of postinfectious BO, the use of anti-inflammatory agents remains controversial. We could not identify any prognostic factors related to disease severity. In order to minimize associated complications, patients with postinfectious BO should be closely followed up and receive meticulous lung care.
Evaluation of Bronchoalveolar Lavage Fluid Phospholipids and Cytokine Release by Alveolar Macrophages as Prognostic Markers in Sarcoidosis
Authors: Tahanovich A.D. , Katovich I.L. , Baradzina H.L.
Published: September 2003

Background: The clinical course of sarcoidosis is unpredictable and reliable laboratory prognostic parameters are lacking. Objectives: The aim of the present study was to estimate the prognostic value of bronchoalveolar lavage fluid (BALF) phospholipids and cytokine production by alveolar macrophages (AM) in pulmonary sarcoidosis. Methods: We investigated BALF parameters in 64 subjects (55 patients with sarcoidosis and 9 healthy volunteers as controls). After a period of 12 months, the total sarcoidosis study population was divided into three groups according to radiological, functional and laboratory dynamics: the group with a favorable (n = 15), the one with an unfavorable (n = 16) and the one with an intermediate clinical course of the disease (n = 24). Results: The group of patients with a poor clinical outcome was characterized by a lower percentage of lymphocytes in BALF [20% (4–56%)], rather small amounts of cytokines [TNF-α: 1.5 ng/ml/106 (0.08–8.6), IL-6: 5.75 ng/ml/106 (1.7–22.5)] and a significant decrease in BALF phospholipids [total lipid phosphorus (TLP): 29.9 µmol/l (13.8–68.3) as compared to 67.5 µmol/l (33.2–127.2) in controls]. Patients with a favorable clinical outcome were shown to have higher lymphocytosis (40%, range 6–64, p < 0.05 versus poor outcome), intensive TNF-α and IL-6 release by AM, and close to normal phospholipid content in BALF. Conclusions: The level of TNF-α secretion by AM <3.9 ng/ml/106 and total lipid phosphorus in BALF less than 30 µmol/l may serve as markers of poor prognosis in pulmonary sarcoidosis.
Double Nuchal Umbilical Cord and Breech Presentation
Authors: Al-Kouatly Huda B. , Schuster Stephen S. , Skupski Daniel W.
Published: September 2003

We report the management of a fetus with breech presentation and double nuchal cord in a mother desiring external cephalic version (ECV). The patient was a 26-year-old woman, gravida 1, para 0, with an unremarkable prenatal course, who was found to have a breech presentation at 34 weeks 1 day. She consented for external cephalic version (ECV) and upon evaluation at 36 weeks 2 days, the fetus was found to have double nuchal coils of the umbilical cord. ECV was not attempted. Subsequent fetal surveillance consisted of fetal movement counts, non-stress tests and Doppler ultrasound of the umbilical artery. At 38 weeks 1 day, ultrasound revealed absence of the nuchal coils. ECV was attempted and was successful. The fetus maintained the cephalic presentation and the patient delivered uneventfully. This case report illustrates the value of follow-up ultrasound in a patient who desires an ECV and for whom such a procedure was declined due to the presence of double nuchal coils. Cesarean delivery was successfully avoided.
Strategies to Increase the Resectability of Liver Metastases from Colorectal Cancer
Authors: Fusai G. , Davidson B.R.
Published: September 2003

Liver resection can provide long-term survival and cure for patients with colorectal liver metastases but is feasible in only 15–25% of patients. In the last few years several major developments have contributed to increase this resectability rate. Neo-adjuvant chemotherapy can provide response rates as high as 50%, allowing surgery in about 10–15% of patients initially deemed unresectable. Patients requiring extensive liver resections with an anticipated small residual liver volume can undergo portal vein embolization to reduce the risk of postoperative liver failure by inducing hypertrophy of the remnant liver. Extensive bilobar disease can be treated by two-stage hepatectomy, with an interval to allow liver regeneration. Ablation techniques can be combined with hepatic resection to reduce local recurrence from incomplete surgical resection margins or to destroy contralateral tumor deposits. Finally, for patients with tumors involving the inferior vena cava or the hepatic veins, in which conventional resection is not feasible, in situ hypothermia or bench resection with reimplantation are suitable for very selected patients. Downstaging strategies may increase the resectability rate of colorectal liver metastases by over 20%.
Apoptosis in the Endometrium of Postmenopausal Women Receiving Tibolone
Authors: Gökaslan Hüsnü , Öktem Özgür , Durmusoglu Fatih , Eren Funda
Published: September 2003

Background/Aim: Tibolone, a synthetic derivative of the 19-nortestosterone family, induces atrophy of the endometrium, especially via its progestogenic Δ4 isomer. The aim of the study was to determine whether tibolone induces apoptosis in the endometrium of postmenopausal women. Methods: Twenty healthy postmenopausal women (mean age ± SD 52.4 ± 4.21 years) who had amenorrhea for at least 1 year and who had no history of any systemic illness and estrogen replacement therapy were enrolled in the study. All patients were offered office endometrial samplings, and then tibolone was prescribed (2.5 mg/day p.o., once daily) to all patients. Repeat endometrial samples were obtained after completion of the 6-month course of tibolone therapy. All samples were immunohistochemically analyzed for the presence of apoptotic cells. Results: There was no significant difference in the median proportion of apoptotic nuclei between the pre- and posttreatment samples (2 vs. 3%; p > 0.05). Conclusions: The results showed that tibolone did not affect the rate of apoptosis in the postmenopausal endometrium. Further studies are needed to clarify the role of apoptosis in overall effects of hormonal compounds on the postmenopausal endometrium.
Experimental Model of Obstructive, Chronic Pancreatitis in Pigs
Authors: Boerma D. , Straatsburg I.H. , Offerhaus G.J.A. , Gouma D.J. , van Gulik T.M.
Published: September 2003

Background: We aimed to develop a reproducible, experimental model of obstructive pancreatitis for future analysis of surgical interventions, and characterized this model using functional, histological and biochemical parameters. Animals and Methods: In 10 female pigs the pancreatic duct (PD) was ligated. After 4, 6 or 8 weeks the animals were sacrificed. Before and after ligation, glucose tolerance and intraductal pressure were measured, and pancreatic juice was collected after stimulation with cholecystokinin and secretin. Amylase and lipase activities were analyzed in plasma and juice. Pancreatic tissue was collected for histochemical analysis. Results: Within 4 weeks of ligation, the pancreas appeared atrophic. Intraductal pressure had risen significantly. Acinar-to-ductal metaplasia was accompanied by strong proliferation of stellate cells and increased collagen deposition. Islets of Langerhans appeared smaller and more numerous. Blood amylase and lipase levels were normal and glucose tolerance was unaffected. Pancreatic juice volume and amylase and lipase activities were significantly lower. Conclusion: Ligation of the PD in pigs resulted in a marked fibrosing obstructive pancreatitis within 4 weeks, similar to human chronic pancreatitis in regard to clinical, functional, histological and biochemical parameters.
Serum Immunosuppressive Acidic Protein as an Interleukin-6 Related Index of Deteriorating Condition in Gastric Cancer Patients
Authors: Ikuta Shin-ichi , Miki Chikao , Tanaka Koji , Konishi Naomi , Mohri Yasuhiko , Tonouchi Hitoshi , Kusunoki Masato
Published: September 2003

Background/Aims: Immunosuppressive acidic protein (IAP) is an acute-phase reactant which has a close correlation with the impairment of the host’s immunity. The present study aims to investigate the significance of serum IAP as an index of cytokine-related disease status in gastric cancer patients. Methods: Serum IAP levels were determined in 76 gastric cancer patients and 20 healthy subjects. In a subgroup of 39 patients, tissue interleukin-6 (IL-6) concentrations and expression of IL-6 protein in tumor tissues were also examined. Results: The mean serum IAP level in the patients was significantly higher than that in the normal controls. The serum IAP level in the patients was associated with clinicopathological features, such as tumor size and serosal invasion. The prognosis of patients with high IAP levels was significantly worse than that of those with low IAP levels. Moreover, the serum IAP level was closely correlated with various parameters reflecting the host’s nutritional and immunological conditions. Immunohistochemically, IL-6 was overexpressed in the cytoplasm of tumor cells. The IL-6 concentration and immunoreactivity of IL-6 protein in tumor tissue was significantly correlated with the serum IAP level. Conclusions: Elevated serum IAP, which may be upregulated by an activated IL-6 network in tumor tissue, may reflect not only tumor progression, but also a deteriorated condition that is associated with malnutrition and immunosuppression in gastric cancer patients.
Dynamical Consequences of Fast-Rising, Slow-Decaying Synapses in Neuronal Networks
Authors: Ermentrout Bard
Published: September 2003

Synapses that rise quickly but have long persistence are shown to have certain computational advantages. They have some unique mathematical properties as well and in some instances can make neurons behave as if they are weakly coupled oscillators. This property allows us to determine their synchronization properties. Furthermore, slowly decaying synapses allow recurrent networks to maintain excitation in the absence of inputs, whereas faster decaying synapses do not. There is an interaction between the synaptic strength and the persistence that allows recurrent networks to fire at low rates if the synapses are sufficiently slow. Waves and localized structures are constructed in spatially extended networks with slowly decaying synapses.
A Universal Model for Spike-Frequency Adaptation
Authors: Benda Jan , Herz Andreas V. M.
Published: September 2003

Spike-frequency adaptation is a prominent feature of neural dynamics. Among other mechanisms, various ionic currents modulating spike generation cause this type of neural adaptation. Prominent examples are voltage-gated potassium currents (M-type currents), the interplay of calcium currents and intracellular calcium dynamics with calcium-gated potassium channels (AHP-type currents), and the slow recovery from inactivation of the fast sodium current. While recent modeling studies have focused on the effects of specific adaptation currents, we derive a universal model for the firing-frequency dynamics of an adapting neuron that is independent of the specific adaptation process and spike generator. The model is completely defined by the neuron's onset f-I curve, the steady-state f-I curve, and the time constant of adaptation. For a specific neuron, these parameters can be easily determined from electrophysiological measurements without any pharmacological manipulations. At the same time, the simplicity of the model allows one to analyze mathematically how adaptation influences signal processing on the single-neuron level. In particular, we elucidate the specific nature of high-pass filter properties caused by spike-frequency adaptation. The model is limited to firing frequencies higher than the reciprocal adaptation time constant and to moderate fluctuations of the adaptation and the input current. As an extension of the model, we introduce a framework for combining an arbitrary spike generator with a generalized adaptation current.
An Adjustment to the Time-Rescaling Method for Application to Short-Trial Spike Train Data
Authors: Wiener Matthew C.
Published: September 2003

It is important to validate models of neural data using appropriate goodness-of-fit measures. Models summarizing some response features—for example, spike count distributions or peristimulus time histograms—can be assessed using standard statistical tools. Measuring the fit of a full point-process model of spike trains is more difficult. Recently, Barbieri, Quirk, Frank, Wilson, and Brown (2001) and Brown, Barbieri, Ventura, Kass, and Frank (2002) presented a method for rescaling time so that if an underlying description correctly describes the conditional intensity function of a point process, the rescaling will convert the process into a homogeneous Poisson process. The corresponding interevent intervals are exponential with mean 1 and can be transformed to be uniform; tests of the uniformity of the transformed intervals are thus tests of how well the model fits the data. When the lengths of interevent intervals are comparable to the length of the observation window, as can happen in common neurophysiology paradigms using short trials, the fact that long intervals cannot be observed (are censored) can cause the tests based on time rescaling to reject a correct model inappropriately. This article presents a simple adjustment to the time-rescaling method to account for interval censoring, avoiding inappropriate rejection of acceptable models for short-trial data. We illustrate the adjustment's effect using both simulated data and short-trial data from monkey primary visual cortex.
Characterization of Subthreshold Voltage Fluctuations in Neuronal Membranes
Authors: Rudolph M. , Destexhe A.
Published: September 2003

Synaptic noise due to intense network activity can have a significant impact on the electrophysiological properties of individual neurons. This is the case for the cerebral cortex, where ongoing activity leads to strong barrages of synaptic inputs, which act as the main source of synaptic noise affecting on neuronal dynamics. Here, we characterize the sub-threshold behavior of neuronal models in which synaptic noise is represented by either additive or multiplicative noise, described by Ornstein-Uhlenbeck processes. We derive and solve the Fokker-Planck equation for this system, which describes the time evolution of the probability density function for the membrane potential. We obtain an analytic expression for the membrane potential distribution at steady state and compare this expression with the subthreshold activity obtained in Hodgkin-Huxley-type models with stochastic synaptic inputs. The differences between multiplicative and additive noise models suggest that multiplicative noise is adequate to describe the high-conductance states similar to in vivo conditions. Because the steady-state membrane potential distribution is easily obtained experimentally, this approach provides a possible method to estimate the mean and variance of synaptic conduct ancesinreal neurons.
Modeling Reaching Impairment After Stroke Using a Population Vector Model of Movement Control That Incorporates Neural Firing-Rate Variability
Authors: Reinkensmeyer David J. , Iobbi Mario G. , Kahn Leonard E. , Kamper Derek G. , Takahashi Craig D.
Published: September 2003

The directional control of reaching after stroke was simulated by including cell death and firing-rate noise in a population vector model of movement control. In this model, cortical activity was assumed to cause the hand to move in the direction of a population vector, defined by a summation of responses from neurons with cosine directional tuning. Two types of directional error were analyzed: the between-target variability, defined as the standard deviation of the directional error across a wide range of target directions, and the within-target variability, defined as the standard deviation of the directional error for many reaches to a single target.

Both between and within-target variability increased with increasing cell death. The increase in between-target variability arose because cell death caused a nonuniform distribution of preferred directions. The increase in within-target variability arose because the magnitude of the population vector decreased more quickly than its standard deviation for increasing cell death, provided appropriate levels of firing-rate noise were present. Comparisons to reaching data from 29 stroke subjects revealed similar increases in between and within-target variability as clinical impairment severity increased. Relationships between simulated cell death and impairment severity were derived using the between and within-target variability results. For both relationships, impairment severity increased similarly with decreasing percentage of surviving cells, consistent with results from previous imaging studies. These results demonstrate that a population vector model of movement control that incorporates cosine tuning, linear summation of unitary responses, firing-rate noise, and random cell death can account for some features of impaired arm movement after stroke.
Radius Margin Bounds for Support Vector Machines with the RBF Kernel
Authors: Chung Kai-Min , Kao Wei-Chun , Sun Chia-Liang , Wang Li-Lun , Lin Chih-Jen
Published: September 2003

An important approach for efficient support vector machine (SVM) model selection is to use differentiable bounds of the leave-one-out (loo) error. Past efforts focused on finding tight bounds of loo (e.g., radius margin bounds, span bounds). However, their practical viability is still not very satisfactory. Duan, Keerthi, and Poo (2003) showed that radius margin bound gives good prediction for L2-SVM, one of the cases we look at. In this letter, through analyses about why this bound performs well for L2-SVM, we show that finding a bound whose minima are in a region with small loo values may be more important than its tightness. Based on this principle, we propose modified radius margin bounds for L1-SVM (the other case) where the original bound is applicable only to the hard-margin case. Our modification for L1-SVM achieves comparable performance to L2-SVM. To study whether L1-or L2-SVM should be used, we analyze other properties, such as their differentiability, number of support vectors, and number of free support vectors. In this aspect, L1-SVM possesses the advantage of having fewer support vectors. Their implementations are also different, so we discuss related issues in detail.
Accurate On-line Support Vector Regression
Authors: Ma Junshui , Theiler James , Perkins Simon
Published: September 2003

Batch implementations of support vector regression (SVR) are inefficient when used in an on-line setting because they must be retrained from scratch every time the training set is modified. Following an incremental support vector classification algorithm introduced by Cauwenberghs and Poggio (2001), we have developed an accurate on-line support vector regression (AOSVR) that efficiently updates a trained SVR function whenever a sample is added to or removed from the training set. The updated SVR function is identical to that produced by a batch algorithm. Applications of AOSVR in both on-line and cross-validation scenarios are presented.Inbothscenarios, numerical experiments indicate that AOSVR is faster than batch SVR algorithms with both cold and warm start.