Melricflash/CW_MedAbstractsAlt huggingface dataset:
Primary biliary cirrhosis: paradigm or paradox for autoimmunity. Primary biliary cirrhosis has been classified as a model autoimmune disease based on striking defects in immune regulation and the presence of autoantibodies to mitochondria. Until recently the significance and definition of mitochondrial autoreactivity was unknown. Since 1987, there has been a vast improvement in the understanding and definition of the biochemical and molecular target autoantigens. The cloning of complementary DNAs for mitochondrial antigens has led to the identification of three enzymes of the 2-oxo-acid dehydrogenase family as the targets of the autoantibodies to mitochondria in patients with primary biliary cirrhosis. The major reactive autoantigen is the E2 subunit of pyruvate dehydrogenase. Immunodominant sites on pyruvate dehydrogenase E2 (autoepitopes) have been mapped and have been shown to be the site of attachment of the functionally important lipoic acid prosthetic group. The autoepitope for the other enzymes probably occupies an equivalent site on the enzyme. The availability and definition of these mitochondrial autoepitopes have allowed specific questions to be addressed relating to the processing and targeting of these autoantigens as well as further studies on mechanisms of immunopathology. Similarly, the availability of well-defined autoantigens could contribute to the development of valid animal models in addition to the already described reproduction of the biliary ductular lesions by transfer of peripheral blood lymphocytes from patients with primary biliary cirrhosis into severe combined immunodeficient mice. Such models will facilitate specific study of the role of major histocompatibility complex expression and the characterization of T-cell reactivity. Thus, primary biliary cirrhosis is a key example of significant progress in autoimmunity being made by use of recombinant DNA technology. 

Category: digestive system diseases
En bloc transplantation of kidneys from donors weighing less than 15 kg. into adult recipients. En bloc transplantation of kidneys from donors who weighed less than 15 kg. into 20 adult patients is described. Intraperitonealization of the medial kidney allowed adequate renal positioning and growth. Graft venous thrombosis occurred in 1 patient and irreversible graft rejection occurred in 4 patients. Graft survival was 65% with excellent function at a mean followup of 8.8 months. En bloc transplantation of pediatric cadaver kidney grafts in adults is an acceptable procedure. 

Category: general pathological conditions
Neurologic complications of cardiac transplantation. Between 1984 and 1989, orthotopic cardiac transplantations were done in 90 patients from 10 to 65 years of age for end-stage, refractory congestive cardiomyopathy. Two patients had had ischemic strokes 5 months and 18 years, respectively, before transplantation. Six patients (7%) suffered acute neurologic events perioperatively. Three patients suffered cerebral infarctions. In 1 case this occurred 10 days before transplantation--probably as a result of systemic hypoperfusion--with the placement of ventricular assist devices. Two others suffered infarctions 5 and 21 days, respectively, after transplantation, each of probable embolic origin. Two patients had an acute intracerebral hemorrhage 21 and 36 days, respectively, after transplantation; both were located within the basal ganglia and subcortical regions. Both patients had moderate to severe hypertension, and in 1, renal failure and a coagulopathy developed before hemorrhage. Tremor, seizures, and an altered level of consciousness developed in 1 patient as an apparent toxic reaction to cyclosporine treatment. Only 1 patient died as a result of the neurologic complication--of an acute intracerebral hemorrhage. Three patients recovered fully, 2 partially. Only the case of drug toxicity could be directly attributed to the transplantation procedure itself. We conclude that the risk of an acute neurologic insult with orthotopic cardiac transplantation is low but may result from drug toxicity, cerebral ischemia, or hemorrhagic mechanisms. 

Category: nervous system diseases
Spontaneous changes in ventricular tachycardia cycle length. Understanding spontaneous fluctuations in ventricular tachycardia cycle length is required to develop algorithms for ventricular tachycardia detection and termination. Variations in cycle length, time to stable cycle length and the range of RR intervals during ventricular tachycardia were analyzed in 74 episodes of sustained monomorphic ventricular tachycardia induced in patients not taking antiarrhythmic medication. Linear regression demonstrated cycle length variability to decrease over time (41 +/- 24 to 17 +/- 19 ms, p less than 0.001). Slower ventricular tachycardia had more cycle length variability than faster ventricular tachycardia (p less than 0.001). Ventricular tachycardia that was initially more variable tended to remain more variable (p less than 0.001). Fifty-four percent of episodes stabilized within the first 15 beats, 75% by 30 beats and 93% by 50 beats. The number of beats to stable cycle length was independent of ventricular tachycardia rate. The average range in cycle length per episode was 127 +/- 72 ms; 12% of ventricular tachycardia episodes varied by less than 50 ms and 45% by less than 150 ms. The maximal range in RR intervals from a single episode of ventricular tachycardia was 290 ms. Therefore, ventricular tachycardia demonstrates a wide range of cycle lengths and has time-dependent changes in variability and stability. These cycle length changes should be considered in the algorithms for ventricular tachycardia detection and termination by automatic antitachycardia devices. 

Category: cardiovascular diseases
Increased sympathetic outflow in cirrhosis and ascites: direct evidence from intraneural recordings. OBJECTIVE: To determine if central sympathetic outflow is increased in patients with cirrhosis and ascites. PATIENTS: Eleven patients with cirrhosis and ascites, 8 patients with cirrhosis but without ascites, and 7 age-matched and 8 young healthy volunteers. METHODS: With subjects supine, direct microneurographic recordings of efferent post-ganglionic muscle sympathetic nerve activity were obtained from the peroneal nerve, and sympathetic burst frequency was compared with subjects' blood pressure, heart rate, sodium excretion, catecholamines, and plasma renin activity. All patients with cirrhosis were studied at least 5 days after withdrawal from all medications and after 7 days of a 20 mmol/d sodium, 1-L fluid-restricted diet. Age-matched volunteers were studied after 7 days of 20 mmol/d sodium intake and young healthy volunteers after 7 days of 150 mmol/d sodium intake. RESULTS: Sympathetic nerve activity in ascitic patients (65 +/- 15 bursts/min; mean +/- SD) was markedly increased, whether compared with patients with cirrhosis but without ascites (34 +/- 16 bursts/min; P less than 0.001), age-matched healthy volunteers on similar sodium intake (27 +/- 22 bursts/min; P less than 0.001), or young healthy subjects (21 +/- 10 bursts/min; P less than 0.001). The frequency of muscle sympathetic nerve discharge was directly related to plasma norepinephrine and epinephrine concentrations, plasma renin activity, and heart rate, all of which were increased in those patients with cirrhosis and ascites, and inversely related to 24-hour urinary sodium excretion, the fractional excretion of sodium, and subjects' pulse pressures. Sympathetic nerve activity fell from 78 to 6 bursts/min in one patient after liver transplantation. CONCLUSIONS: This study provides the first direct evidence that elevated plasma norepinephrine concentrations in patients with cirrhosis and ascites are due to increased central sympathetic outflow. Sympathetic nerve activity is not increased in patients with cirrhosis but without ascites. Because there were direct positive correlations of sympathetic nerve activity with plasma norepinephrine concentrations, plasma epinephrine concentrations, plasma renin activity, and heart rate, the increase in central sympathetic outflow in patients with cirrhosis and ascites appears generalized and not restricted to muscle nerves. The anti-natriuretic effects of parallel increases in renal and muscle sympathetic nerve activity could account for the inverse correlation between muscle sympathetic nerve activity and sodium excretion. 

Category: general pathological conditions
Prognostic significance of the white nipple sign in variceal bleeding. The prognostic significance of the white nipple sign in variceal bleeding was evaluated prospectively in 203 separate admissions for bleeding esophageal varices in 145 cirrhotic patients. During all admissions a standardized protocol of management defined the failure of transfusion and vasoactive drugs (conservative measures) to stop bleeding and the occurrence of early rebleeding, at which time either emergency sclerotherapy or a staple transection of the esophagus was used. The finding of a white nipple in 18 admissions (9%) did not have predictive value as regards the failure of conservative measures to stop bleeding within 24 hours or rebleeding within 5 days, and there was no association with increased mortality. In one case, a white nipple was seen to occur after spontaneous cessation of a variceal venous spurt, suggesting it is a platelet-fibrin plug. The white nipple sign is diagnostic of a varix that has bled but has no adverse prognostic significance. 

Category: general pathological conditions
Implantation of an endoluminal prosthesis at the distal anastomosis of a bypass graft for abrupt closure following balloon angioplasty. A coronary Wallstent was implanted in a 10-year-old saphenous vein bypass graft following a PTCA that was complicated by abrupt closure. Anterograde flow was restored and no myocardial necrosis resulted. One week later, bypass surgery was performed due to a bleeding complication associated with the anticoagulation regimen. 

Category: cardiovascular diseases
The renin-angiotensin-aldosterone system and autosomal dominant polycystic kidney disease BACKGROUND. A high incidence of hypertension (50 to 75 percent) occurs early in the course of autosomal dominant polycystic kidney disease. Cyst enlargement, causing bilateral renal ischemia and subsequent release of renin, is proposed as the cause of this form of hypertension. METHODS. To investigate this hypothesis, we measured plasma renin activity and aldosterone concentrations during short-term and long-term converting-enzyme inhibition in 14 patients with hypertension due to polycystic kidney disease, 9 patients with essential hypertension, 11 normotensive patients with polycystic kidney disease, and 13 normal subjects. The groups were comparable with respect to age, sex, body-surface area, degree of hypertension, sodium excretion, and renal function. RESULTS. During the short-term study, the mean (+/- SE) plasma renin activity was significantly higher in the hypertensive patients with polycystic kidney disease than in the patients with essential hypertension, in the supine (0.36 +/- 0.06 vs. 0.22 +/- 0.06 ng per liter.second, P = 0.05) and upright positions (1.03 +/- 0.14 vs. 0.61 +/- 0.08 ng per liter.second, P less than 0.03) and after converting-enzyme inhibition (1.97 +/- 0.28 vs. 0.67 +/- 0.17 ng per liter.second, P less than 0.0006). The mean arterial pressures measured in the supine and upright positions and the plasma aldosterone concentrations measured in the upright position were significantly higher in the normotensive patients with polycystic kidney disease than in the normal subjects. After six weeks of converting-enzyme inhibition, renal plasma flow increased (P less than 0.005), and both renal vascular resistance (P less than 0.007) and the filtration fraction (P less than 0.02) decreased significantly in the hypertensive patients with polycystic kidney disease but not in the patients with essential hypertension. CONCLUSIONS. The renin-angiotensin-aldosterone system is stimulated significantly more in hypertensive patients with polycystic kidney disease than in comparable patients with essential hypertension. The increased renin release, perhaps due to renal ischemia caused by cyst expansion, probably contributes to the early development of hypertension in polycystic kidney disease. 

Category: cardiovascular diseases
Prospective comparison of a conventional and an accelerated protocol for programmed ventricular stimulation in patients with coronary artery disease. BACKGROUND. This study compared the sensitivity, specificity, and efficiency of a "conventional" and "accelerated" programmed stimulation protocol in 293 patients with coronary artery disease who had a history of sustained or nonsustained monomorphic ventricular tachycardia (VT). METHODS AND RESULTS. In the conventional protocol, one and two extrastimuli were introduced during sinus rhythm and during basic drive trains at cycle lengths of 600 and 400 msec at the right ventricular apex and then at the outflow tract or septum. In the accelerated protocol, one, two, and then three extrastimuli were introduced at each of three basic drive train cycle lengths (350, 400, and 600 msec) at the right ventricular apex; the procedure was repeated at a second right ventricular site. Six hundred thirty-four electrophysiological tests were performed using one of these two protocols either in the baseline state (293 tests) or during drug testing (341 tests). The yield of sustained, monomorphic VT was 89% with the conventional protocol and 92% with the accelerated protocol during baseline tests in patients who had a history of sustained VT (p = 0.05); 20% and 34%, respectively, during baseline tests in patients with a history of nonsustained VT (p = 0.06); and 70% and 77%, respectively, during drug testing (p = 0.2). To induce sustained, monomorphic VT, 10.1 +/- 5.0 (mean +/- SD) protocol steps and 14.4 +/- 8.7 minutes were required with the conventional protocol, compared with 4.0 +/- 3.7 steps and 5.6 +/- 6.1 minutes with the accelerated protocol (p less than 0.001 for each comparison). Among the tests in which sustained, monomorphic VT was induced, sustained polymorphic VT or ventricular fibrillation was induced more often with the conventional protocol (3.6%) than with the accelerated protocol (0.9%, p = 0.05). CONCLUSIONS. The efficiency of programmed stimulation can be improved by the early use of a basic drive train cycle length of 350 msec and three extrastimuli. Compared with a conventional stimulation protocol, the accelerated protocol used in this study reduces the number of protocol steps and duration of time required to induce monomorphic VT by an average of more than 50% and improves the specificity of programmed stimulation without impairing the yield of monomorphic VT. 

Category: cardiovascular diseases
Early gastric cancer. Twenty-eight-year experience. A retrospective study of early gastric cancer (60 patients) was performed to evaluate its diagnosis and treatment. Ninety-five per cent of patients presented with nonspecific gastrointestinal symptoms and 53.3% had been treated for presumed benign disease for up to 48 months before diagnosis. Fiberoptic endoscopy detected these lesions more accurately than radiologic examination. The disease-free 5-year survival rate after resection was 76.4%. Survival showed no significant correlation with sex, tumor site, macroscopic appearance, extent of gastric resection, or histopathologic type. Tumors larger than 1.5 cm in diameter, invasion of submucosa, or lymph node metastasis resulted in significantly lower survival rates. Three of eight patients with nodal metastasis survived 5 or more years, including one who had second-echelon deposits. A high index of suspicion may permit more frequent detection. Extended lymphadenectomy (R2) is recommended to achieve the highest possible cure rate. 

Category: neoplasms
Early development of levodopa-induced dyskinesias and response fluctuations in young-onset Parkinson's disease. We evaluated whether patients with young-onset Parkinson's disease (PD) (onset between 21 and 40 years) develop levodopa-induced dyskinesias and motor response fluctuations more frequently and earlier than patients with older-onset PD (onset after 40 years) by determining the period from levodopa introduction to development of dyskinesias or fluctuations in 25 young-onset (mean age at onset, 33.54 years) and in 25 matched older-onset PD patients (mean age at onset, 55.76 years). Young-onset PD patients had significantly higher frequency for both dyskinesias and fluctuations after both 3 and 5 years of levodopa. Young-onset PD patients also developed both levodopa-induced dyskinesias and fluctuations earlier than older-onset PD patients. We suggest that the introduction of levodopa therapy in patients with young onset PD should be postponed as long as possible. 

Category: nervous system diseases
Nonsteroidal antiinflammatory drug-induced colonic strictures: a case report. Adverse effects of nonsteroidal antiinflammatory drugs can occur throughout the whole gastrointestinal tract. Recently, several cases of "diaphragmlike" thin ileal strictures have been reported. These strictures seem to result from nonsteroidal antiinflammatory drug-induced inflammatory changes and apparently represent a newly recognized nosological entity. The case of a 61-year-old man who gradually developed similar inflammatory changes in the ascending colon during prolonged intake of a slow-release form of diclofenac is presented, and the literature on nonsteroidal antiinflammatory drug-induced intestinal strictures is briefly reviewed. 

Category: digestive system diseases
A practical approach to the painful bladder syndrome. The painful bladder syndrome (PBS) is a progressive and painful disease of the bladder that may lead to fibrosis, contracture and reduction of bladder capacity. The usual symptoms are urinary urgency, frequency, nocturia, chronic pelvic pain and lower abdominal pain upon filling of the bladder. A retrospective analysis was performed on 21 women with PBS between March 1987 and March 1988. The patients were treated weekly with a bladder pillar block, bladder distention and dimethyl sulfoxide instillation. Symptomatic relief was observed in 80% of the patients so treated. The maximum bladder volume increased from 185 to 475 mL (P less than .01). The side effects were minimal. 

Category: nervous system diseases
Mitochondrial encephalomyopathies. The mitochondrial diseases present with great heterogeneity. They are often multisystemic and vary considerably in age at onset, distribution of weakness, severity, and course. Only nonthyroidal hypermetabolism has a distinctive clinical presentation. Therefore, attempts at classification have generated some controversy. This article discusses the general classification that takes into account genetic and biochemical features, which has resulted from the fast pace of biochemical and molecular genetic investigations. 

Category: general pathological conditions
Unsuspected cocaine exposure in young children. OBJECTIVE: To determine the prevalence of cocaine exposure among preschool children with clinically unsuspected signs and/or symptoms. DESIGN: Prevalence study. SETTING: Pediatric emergency department in an inner-city hospital. PARTICIPANTS: 250 children aged 2 weeks to 5 years who underwent urine assays for cocaine prior to discharge from the emergency department. INTERVENTIONS: None. MEASUREMENTS/MAIN RESULTS: Six (2.4%) of the 250 urine assays (95% confidence interval, 0.5% to 4.3%) were positive for benzoylecgonine, the major urinary cocaine metabolite. Four of the positive urine assays were from children younger than 1 year and all children with positive urine assays were younger than 24 months. None of these children presented with a complaint or was identified as having clinical problems currently associated with childhood exposure to cocaine. Possible exposure routes include breastfeeding, intentional administration, accidental ingestion of cocaine or cocaine-contaminated household dust via normal hand-to-mouth activity, and passive inhalation of "crack" vapors. CONCLUSION: Among the inner-city children served by this hospital, significant numbers of infants and young children are being exposed to cocaine, and this exposure occurs in a clinically unsuspected population. 

Category: general pathological conditions
Effect of electrocautery on wound healing in midline laparotomy incisions. The effect of electrocautery on midline fascial wound healing was studied in 108 Sprague-Dawley rats. Midline wound tensile strength was significantly reduced in fascia incised with the coagulation current compared with the cutting current or scalpel. In addition, tissue necrosis and inflammation as well as adhesion formation between the incision and abdominal viscera were more extensive in animals with incisions made using coagulation current. The results of the study indicate that the use of electrocautery coagulation current is associated with increased tissue damage and a significant reduction in the tensile strength of healing wounds. The contribution of electrocautery to wound complications in patients needs further evaluation. 

Category: general pathological conditions
Metaplastic change in mesenchymal stem cells induced by activated ras oncogene. 3T3 T murine mesenchymal stem cells have the potential to differentiate into a variety of different cell types even though they show a predilection to undergo adipocyte differentiation in vitro. The possibility that the activated c-Ha-ras (EJras) oncogene might influence the pathway of differentiation of these stem cells is investigated in the current study. Activated ras oncogene was transfected and stably expressed in 3T3 T cells; assays then were performed to determine its effect on differentiation. The results show that all EJras-transfected cell lines lose their ability to differentiate to adipocytes and instead differentiate into cells that express many characteristics of macrophages. Such cells contain numerous cytoplasmic granules, extensive nonspecific esterase activity, and anchorage-independent growth. The modulation of differentiation pathway from an adipocyte lineage to a macrophagelike cell lineage does not result from the transforming effect of EJras, because a nontransformed cell clone that expresses p21EJras protein also exhibits this modified differentiation pathway. These data suggest that the EJras oncogene specifically modulates the differentiation pathway of 3T3 T mesenchymal stem cells. This experimental system should therefore provide an excellent model to evaluate the mechanistic role of EJras in the process of metaplasia. 

Category: general pathological conditions
Pregnancy and the risk of hemorrhage from cerebral arteriovenous malformations. We conducted a retrospective analysis of 451 women with an arteriovenous malformation (AVM) of the brain to determine whether pregnancy is a risk factor for cerebral hemorrhages. A total of 540 pregnancies occurred among our patient population, resulting in 438 live births and 102 abortions. There were 17 pregnancies complicated by a cerebral hemorrhage. The hemorrhage rate during pregnancy for women with an unruptured AVM was 0.035 +/- 0.005 per person-year. The hemorrhage rate for nonpregnant women of childbearing age with an unruptured AVM was 0.031 +/- 0.002 per person-year. Pregnancy did not increase significantly the rate of first cerebral hemorrhage from an AVM (P = 0.35). We found that women with an AVM face a 3.5% risk of hemorrhage during pregnancy. Pregnancy is not a risk factor for hemorrhage in women without a previous hemorrhage. This conclusion assumes no selection bias exists in our study population; a bias would be introduced if the risk of fatal outcome after a hemorrhage were greater in pregnant women than in nonpregnant women. 

Category: general pathological conditions