shukoor65/lab-rag-model huggingface dataset:
Hypoxaemia during anaesthesia--an observer study. We have investigated 296 inpatients in a single-blind observer study to determine the incidence, degree and duration of hypoxaemia during anaesthesia. The clinical recognition of hypoxaemia, period of time until recognition and risk factors were studied. Oxygen saturation (Spo2) was monitored continuously with a pulse oximeter (Ohmeda, model 3700). One or more episodes of mild hypoxaemia (Spo2 86-90%) were recorded in 53% of patients. Severe hypoxaemia with Spo2 values less than 81% were recorded in 20% of patients. The mild hypoxaemic episodes lasted up to 34.6 min (mean 2.3 min) and 70% were not detected by the anaesthetist. In the remaining 30% of episodes, the anaesthetist diagnosed the complication with a mean time delay of 70 s. After intervention a mean time delay of 57 s was recorded until Spo2 exceeded 90%. Utilizing a stepwise multiple logistic regression analysis, we found that risk factors associated with a greater incidence of hypoxaemia were patient age (P less than 0.005) and anaesthetic technique (P less than 0.00001). We conclude that hypoxaemic episodes in our operating rooms are common during anaesthesia and suggest preoxygenation in all patients in addition to administration of supplementary oxygen during arousal from anaesthesia and during transfer to the recovery room.
Portal venous barium intravasation complicating barium enema examination. Venous intravasation of contrast is a potentially life-threatening complication of the barium enema examination. A patient in whom portal venous contrast intravasation was nearly fatal is presented, and the significant morbidity and mortality from this unusual event is reviewed. Since barium infiltration into the venous system almost always occurs in the setting of altered mucosal integrity, this examination should be used cautiously in patients with inflammatory bowel disease or diverticulitis. Prompt recognition and rapid resuscitation are critical to the survival of patients with contrast intravasation.
Tricuspid atresia: association with persistent truncus arteriosus. Clinical, echo-Doppler, and pathologic data of a rare case of tricuspid atresia in association with truncus arteriosus are presented. There are only six patients (including the patient reported here) with this anomaly in whom detailed pathologic and/or clinical descriptions are available in the literature. An additional six cases were mentioned in the literature but without any details. A prevalence rate of 1.4% among tricuspid atresia cases is estimated. All infants presented with symptoms of cyanosis and/or congestive heart failure within a few days to 2 months after birth and died shortly thereafter. Cardiomegaly and increased pulmonary vascular markings on the chest x-ray film and left axis deviation with left ventricular hypertrophy on the ECG are usually present. Echocardiographic, catheterization, and angiocardiographic studies are helpful in documenting anatomic and physiologic features of this anomaly. Pathologically, the muscular type of tricuspid atresia, type I or II truncus arteriosus, a large subtruncal VSD, and a hypoplastic right ventricle are present. It is concluded that coexistence of tricuspid atresia and truncus arteriosus is rare; clinical, laboratory, and pathologic features are distinctive; the clinical presentation early in life with rapid demise is common; and prompt palliative surgery immediately after recognition of this anomaly should be undertaken.
Association of exotoxin-producing group A streptococci and severe disease in children. Clinical features and microbiologic data on all cases of serious (hospitalized) Group A streptococcal infections in children managed at our institution between 1985 and 1988 are presented. All 6 cases were caused by toxin-producing strains. Four of 6 were toxin A-producing strains whereas none of 58 community-acquired (Group A streptococcal) pharyngeal isolates in the same period was a toxin A producer. A review of the literature on the incidence of toxin A-producing strains provides information suggesting a resurgence of such strains in the late 1980s after a relative disappearance of toxin B production in isolates from these patients was also significantly greater than in the isolates acquired from the community in uncomplicated pharyngitis. These findings suggest a role for exotoxin in severe manifestations of Group A streptococcal disease in children.
Distribution of thymic tissue in the mediastinal adipose tissue. The distribution of thymic tissue in the anterior mediastinal, retrocarinal, and preaortic fat was examined histologically in 27 autopsy subjects. Thymic tissue was found in the anterior mediastinal fat in 12 subjects (44.4%), in the retrocarinal fat in two (7.4%), and in the preaortic fat in none. The finding of ectopic thymic tissue in these areas has not been reported previously, would appear to be surgically inaccessible via a median sternotomy, and may be responsible in part for some of the failures of thymectomy in the treatment of myasthenia gravis.
Identifying anterior segment crystals. A series of 22 patients with crystals in the anterior segment of the eye was examined by specular microscopy. Of 10 patients with hypermature cataract and hyperrefringent bodies in the anterior chamber cholesterol crystals were identified in four patients and in six of the 10 in whom aspirate was obtained cholesterol crystals were demonstrated in three, two of these having shown crystals on specular microscopy. In 10 patients with intracorneal crystalline deposits, cholesterol crystals were found on specular microscopy, including one case of Schnyder's crystalline corneal dystrophy. Of two patients with multiple myeloma, corneal crystals were demonstrated in one. Crystals of the anterior segment of the eye are most likely to be cholesterol, and identification is important for future treatment.
Simple examination techniques to aid in the diagnosis of urethral diverticulum. Patients with urethral diverticula classically present with dyspareunia, dribbling of urine, chronic dysuria, and/or a tender suburethral mass. Physical examination, urethroscopy, positive pressure urethrography, and the urethral pressure profile may not confirm the suspected diagnosis. Three simple diagnostic maneuvers are presented to aid in confirming the diagnosis before surgical exploration.
Symptomatic and silent gall stones in the community. The prevalence of gall stone disease in a stratified random sample of 1896 British adults (72.2% of those approached) was established using real time ultrasound. The prevalence rose with age, except in women of 40-49 years, so that at 60-69 years, 22.4% of women and 11.5% of men had gall stones or had undergone cholecystectomy. The cholecystectomy rate of people with gall stone disease was higher in women than in men (43.5% v 24%, p less than 0.05). Very few subjects with gall stones had convincing biliary symptoms. In women, 10.4% had symptoms according to a questionnaire definition of biliary pain and 6.3% according to conventional history taking, while no men at all admitted to biliary pain. Nevertheless, cholecystectomy in men had nearly always been preceded by convincing biliary symptoms. The age at cholecystectomy was, on average, nine years less than the age at detection of silent gall stones in both sexes. It is concluded that either gall stones are especially prone to cause symptoms in younger people or that there are two kinds of cholelithiasis - symptomatic and silent. The lack of symptomatic gall stones in cross sectional surveys is probably due to their rapid diagnosis and treatment.
Genetic susceptibility to Parkinson's disease. Genetic factors clearly cause Lewy-body Parkinson's disease (PD) in a subset of autosomal-dominant families. However, most cases of PD are sporadic. The two most likely models of four discussed for sporadic PD are the reduced penetrance model and the multifactorial model. Sporadic PD is likely to be caused by the combined effect of environmental precipitating factors and genetic susceptibility factors. Because the number of major genetic factors is likely to be small, these hypotheses can be tested and genetic factors located using linkage mapping techniques. The affected pair analysis methods are especially suited to PD. Finding the genetic susceptibility factors for PD is important because this may be the fastest way to identify the environmental precipitating factors and because it may lead to prevention of PD. Because of the usefulness of identifying genetic susceptibility factors for PD, we are carrying out linkage studies in a group of 16 large autosomal-dominant families with PD and more than 300 living affected PD pairs.
The rhombotin family of cysteine-rich LIM-domain oncogenes: distinct members are involved in T-cell translocations to human chromosomes 11p15 and 11p13. A chromosomal translocation in a T-cell leukemia involving the short arm of human chromosome 11 at band 11p15 disrupts the rhombotin gene. This gene encodes a protein with duplicated cysteine-rich regions called LIM domains, which show homology to zinc-binding proteins and to iron-sulfur centers of ferredoxins. Two homologues of the rhombotin gene have now been isolated. One of these, designated Rhom-2, is located on human chromosome 11 at band 11p13, where a cluster of T-cell leukemia-specific translocations occur; all translocation breakpoints at 11p13 are upstream of the Rhom-2 gene. Human and mouse Rhom-2 are highly conserved and, like rhombotin, encode two tandem cysteine-rich LIM domains. Rhom-2 mRNA is expressed in early mouse development in central nervous system, lung, kidney, liver, and spleen but only very low levels occur in thymus. The other gene, designated Rhom-3, is not on chromosome 11 but also retains homology to the LIM domain of rhombotin. Since the Rhom-2 gene is such a common site of chromosomal damage in T-cell tumors, the consistency of translocations near the rhombotin gene was further examined. A second translocation adjacent to rhombotin was found and at the same position as in the previous example. Therefore, chromosome bands 11p15 (rhombotin) and 11p13 (Rhom-2) are consistent sites of chromosome translocation in T-cell leukemia, with the 11p15 target more rarely involved. The results define the rhombotin gene family as a class of T-cell oncogenes with duplicated cysteine-rich LIM domains.
Different mechanisms of polyuria and natriuresis associated with paroxysmal supraventricular tachycardia. The mechanism of polyuria associated with paroxysmal supraventricular tachycardia (SVT) was investigated in 8 patients. SVT was induced artificially and sustained for 60 minutes. Urine and blood samples were collected every 30 minutes. During the latter half of SVT, urine flow increased twofold in the control subjects before SVT. Urinary sodium excretion increased significantly (p less than 0.01) within 30 minutes after SVT. Urinary excretion of antidiuretic hormone (ADH) decreased (p less than 0.01) during the latter half of SVT and increased (p less than 0.01) after SVT, respectively. Plasma level of ADH did not change during SVT but increased (p less than 0.05) after SVT. The concentration of plasma atrial natriuretic polypeptide (ANP) increased significantly (p less than 0.05) before SVT ended. Urinary excretion of prostaglandin E2 increased significantly (p less than 0.05) after termination of SVT. The percent changes in the urinary excretion of prostaglandin E2 were correlated (r = 0.713, p less than 0.001) with those of ADH. There was also a correlation (r = 0.6, p less than 0.001) between the percent changes in the urinary excretion of prostaglandin E2 and those of sodium. Their findings suggest that the polyuria during SVT is attributed mainly to the inhibition of ADH release and that the natriuresis after SVT is due not only to the increased ANP but also to the increased renal prostaglandin E2 probably stimulated by ADH.
Comparison of acute and chronic protein-energy malnutrition on host antitumor immune mechanisms. Protein-calorie malnutrition (PCM) is prevalent in cancer patients. However, the effect of PCM on anti-tumor immunity is unclear and critically important in an era of improving results with adoptive immunotherapy. This study examined the effect of short- and long-term PCM on tumor-specific and natural immune effector mechanisms in a murine neuroblastoma (C1300 NRB) model. A/J mice received an isocaloric 2.5% or 24% casein diet for 3 or 8 weeks before inoculation with tumor. Three weeks later lymphocytes from tumor-bearing mice were harvested for determination of cytotoxic T lymphocyte (CTL) generation and natural killer (NK) cell cytotoxicity. Both 3 and 8 weeks of PCM significantly reduced mean total body weight by 25% (p less than 0.001) and 41% (p less than 0.001), respectively, compared with regularly nourished mice. Short-term PCM did not inhibit CTL or NK cytotoxicity, whereas long-term PCM significantly diminished CTL generation (p less than 0.001) but preserved NK cytotoxic function. These results indicate that CTL development against autologous tumor, in contrast to basal NK function, is dependent on host nutritional status. Mean tumor growth, determined by tumor-weight to carcass-weight ratio, was unchanged for both short- and long-term protein-energy deprived groups compared with results in regularly nourished mice. These findings suggest that NK function is the predominant effector mechanism inhibiting C1300 NRB growth and that NK tumoricidal capacity is preserved during PCM.
Pathophysiology of isolated systolic hypertension in elderly patients: Doppler echocardiographic insights. Systemic hemodynamics were evaluated with aortic pulsed wave Doppler echocardiography in 79 elderly subjects with isolated systolic hypertension participating in the Systolic Hypertension in the Elderly Program (SHEP) and were compared with the values in 39 normal age-matched subjects. Cardiac output was elevated (4.50 +/- 1.13 L/min versus 3.94 +/- 1.12 L/min, p less than 0.05) in patients with isolated systolic hypertension in comparison with values in normal elderly subjects. Systemic vascular resistance did not differ between both groups (2140 +/- 536 dyn.sec/cm-5 versus 2011 +/- 553 dyn.sec/cm-5, p = NS). The mean acceleration of blood during left ventricular ejection was similar in patients with isolated systolic hypertension in comparison with normals (12.6 +/- 5.6 m/sec2 versus 11.5 +/- 3.5 m/sec2, p = NS). Patients with isolated systolic hypertension had significantly decreased arterial compliance, as measured by the stroke volume-to-pulse pressure ratio (0.77 +/- 0.26 cm3/mm Hg versus 1.11 +/- 0.30 cm3/mm Hg, p less than 0.0001). The prevalence of aortic and mitral regurgitation as well as valvular and annular calcification did not differ between analyzed groups. Isolated systolic hypertension in elderly patients appears to be multifactorial, with reduced arterial compliance and increased cardiac output both playing a role.
Reading problems in adult chronic headache sufferers. In a questionnaire survey we determined the prevalence of problems with reading, at present as well as in the past, in adult chronic headache sufferers as compared with age- and sex-matched controls. The reading problems inquired about were those with reading in general, reading quickly, prolonged reading and reading comprehension. The subjects were also asked about present and past problems with writing, concentrating, performing mathematics and overall learning. Significant differences in the prevalences of the problems studied between the headache sufferers and controls were observed on just two items and only for the female groups. These items were present problems with reading comprehension (39.3% versus 7.5%; p = 0.002) and concentrating (46.4% versus 17.5%; p = 0.015). We concluded that adult female headache sufferers have impaired reading comprehension and concentration abilities which do not seem to originate from the past.
Paramyotonia congenita and hyperkalemic periodic paralysis map to the same sodium-channel gene locus. Paramyotonia congenita (PC), an autosomal dominant muscle disease, shares some clinical and electrophysiological similarities with another myotonic muscle disorder, hyperkalemic periodic paralysis (HYPP). However, clinical and electrophysiologic differences allow differentiation of the two disorders. The HYPP locus was recently shown to be linked to a skeletal muscle sodium-channel gene probe. We now report that PC maps to the same locus (LOD score 4.4, theta = 0 at assumed penetrance of .95). These linkage results, coupled with physiological data demonstrating abnormal sodium-channel function in patients with PC, implicate a sodium-channel gene as an important candidate for the site of mutation responsible for PC. Furthermore, this is strong evidence for the hypothesis that PC and HYPP are allelic disorders.
Efficacy of low-molecular-weight heparin in the management of intermittent claudication. Treating chronic arterial occlusive disease with heparin is controversial because of the risks associated with long-term anticoagulant therapy. Low molecular weight (LMW) heparin (mw about 5000 Dalton), which selectively inhibits the Xa factor with minimal risk of hemorrhage, seems to offer new possibilities in the prevention and treatment of both venous and acute arterial thromboembolism. Therefore, 44 patients with intermittent claudication were recruited to a randomized, double-blind, controlled study. Twenty-two were treated for six months with a single daily subcutaneous dose (15,000 UaXa) of LMW heparin and 22 with placebo administered in the same way over the same period of time. After six months, LMW heparin treatment not only improved walking capacity (by lengthening the pain-free walking time by 25%) but also significantly modified the hemorrheologic pattern (by reducing fibrinogen concentrations and whole blood viscosity at low shear rates). LMW heparin also exerted an antithrombotic and profibrinolytic effect by significantly increasing both the anti-Xa factor and plasminogen activity without markedly modifying activated partial thromboplastin time (+20%). No LMW heparin-treated patient hemorrhaged or reported other noteworthy side effects. These results suggest LMW heparin might be a useful drug in the long-term treatment of chronic arterial occlusive disease of the limbs.
Role of conversion of xanthine dehydrogenase to oxidase in ischemic rat liver cell injury. This study was undertaken to determine whether hepatic ischemia and the subsequent reflow of blood have any effect on the conversion of xanthine dehydrogenase to xanthine oxidase (XO). Ischemia of the liver for 90 or 120 minutes did not permit survival of the animals. XO represented 15% of the total xanthine dehydrogenase plus XO activity in the control liver. XO activity remained unchanged even after 90 minutes of hepatic ischemia, although a marked increase in lipid peroxide in the liver tissue was observed during the reperfusion. When hepatic ischemia was prolonged for 6 hours (animals were dead), XO activity rose to 35% of the total activity. Incubation of the liver at 37 degrees C resulted in a definite change in XO activity dependent on the length of incubation period. Although no significant changes occurred in XO activity during the first 2 hours of incubation, a marked XO conversion was observed between 2 and 4 hours, and a maximal conversion was achieved after 6 hours of incubation. These results suggest that XO newly generated during ischemia has a very limited role in oxygen free radical production after resuming perfusion.
Increased therapeutic index of antineoplastic drugs in combination with intracellular histamine antagonists. L-Histidinol, a protein synthesis inhibitor and structural analogue of L-histidine, has been demonstrated in chemotherapy-treated mice to be cytoprotective to normal stem cells but to enhance cytotoxicity to tumor cells. N,N-Diethyl-2-[4-(phenylmethyl) phenoxy]ethanamine.HCl (DPPE) is an antagonist of recently described microsomal and nuclear intracellular histamine receptors implicated in the mediation of proliferation and modulation of prostaglandin synthesis. DPPE is cytotoxic to tumor cells in vitro and cytoprotective to the gut in vivo. Noting the similar pharmacologic profiles for histidinol and DPPE and the structural resemblance between histidinol and histamine, we tested 1) whether binding to intracellular histamine receptors may be important to the action of histidinol, 2) whether there exists a differential effect of DPPE and histidinol on proliferating normal and transformed or malignant cells, and 3) whether DPPE, like histidinol, protects host cells from the effects of chemotherapy while augmenting tumor cell kill in vivo. It was observed that histidinol does compete at intracellular histamine receptors in isolated microsomes and nuclei, but with significantly lower affinity than DPPE. Nevertheless, for each agent, potency at intracellular histamine receptors correlates with potency to inhibit DNA and protein synthesis, without cytotoxicity, in normal mitogen-stimulated murine lymphocytes and to kill transformed mouse lymphocytes or MCF-7 human breast cancer cells. As demonstrated previously for histidinol (1-2 g/kg), DPPE (4 mg/kg) protected murine bone marrow progenitors from doxorubicin or fluorouracil, while doses of 4-50 mg/kg significantly enhanced the antitumor activity of doxorubicin and daunorubicin in murine models of early cancer. One postulate to explain the effects of intracellular histamine receptor ligands is that intracellular histamine mediates DNA and protein synthesis, possibly through a downward modulation of growth-inhibitory prostaglandin levels. Antagonism of the intracellular action of histamine at intracellular histamine receptors by DPPE or histidinol may result in differential perturbations of growth/eicosanoid metabolism in normal and malignant cells, thus forming the basis of a new approach to chemotherapy.
Alfentanil infusion for postoperative pain: a comparison of epidural and intravenous routes. The efficacy of intravenous (iv) and epidural infusions of alfentanil for postoperative pain relief was investigated in 24 patients (ASA physical status 1-2) who were scheduled for abdominal hysterectomy. The patients were allocated randomly to receive either epidural or iv alfentanil. In both groups, a loading dose of 15 micrograms.kg-1 was administered, followed by a constant rate infusion of 18 micrograms.kg-1.h-1 alfentanil for 20 h. Both routes provided similar degrees of analgesia; however, analgesia occurred earlier in the intravenously treated group (P less than 0.03). Mean plasma alfentanil concentrations (Cps) varied between 42 and 82 ng.ml-1 in the iv group and 23 and 68 ng.ml-1 in the epidural group, with higher concentrations in the iv group for the first 60 min only (P less than 0.01). Cps increased with infusion time, suggesting accumulation of alfentanil. After infusion ended, pain recurred at the same time in both groups, whereas the alfentanil Cps still were greater than 45 ng/ml. Postoperative epinephrine concentrations decreased after 60 min of infusion (P less than 0.02), whereas, after 6 h, cortisol levels decreased to preoperative values. Norepinephrine concentrations decreased only slightly. The only clinically meaningful effect on vital signs that occurred was an abrupt reduction of respiratory rate after the iv loading dose. PaCO2 increased to the same extent in both groups during the first 15 min only. The incidence of opioid-related side effects was similar in both groups. These results suggest that the iv and epidural routes were equally effective for providing postoperative pain control and controlling the postoperative response to surgical stress.