Melricflash/CW_MedAbstractsAlt huggingface dataset:
Identification of a cDNA encoding a second putative prohormone convertase related to PC2 in AtT20 cells and islets of Langerhans. PC2 and furin are two recently identified members of a class of mammalian proteins homologous to the yeast precursor processing protease kex2 and the bacterial subtillisins. We have used the polymerase chain reaction to identify and clone a cDNA (PC3) from the mouse AtT20 anterior pituitary cell line that represents an additional member of this growing family of mammalian proteases. PC3 encodes a 753-residue protein that begins with a signal peptide and contains a 292-residue domain closely related to the catalytic modules of PC2, furin, and kex2. Within this region 58%, 65%, and 50% of the amino acids of PC3 are identical to those of the aligned PC2, furin, and kex2 sequences, respectively, and the catalytically important Asp, His, and Ser residues are all conserved. On Northern blots, PC3 hybridizes to two transcripts of 3 and 5 kilobases. Tissue distribution studies indicate that both PC2 and PC3 are expressed in a variety of neuroendocrine tissues, including pancreatic islets and brain, but are not expressed in liver, kidney, skeletal muscle, and spleen. The high degree of similarity of PC3, PC2, and furin suggests that they are all members of a superfamily of mammalian proteases that are involved in the processing of prohormones and/or other protein precursors. In contrast to furin, PC3, like PC2, lacks a hydrophobic transmembrane anchor, but it has a potential C-terminal amphipathic helical segment similar to the putative membrane anchor of carboxypeptidase H. These and other differences suggest that these proteins carry out compartmentalized proteolysis within cells, such as processing within regulated versus constitutive secretory pathways. 

Category: neoplasms
Bleeding ectatic vascular lesion involving the sigmoid colon, endoscopically indistinguishable from angiodysplasia, in an 8-yr-old boy. An 8-yr-old Japanese boy was hospitalized, complaining of active hematochezia. He was shown to have a cherry-red, blood-oozing area of vascular dilation with mucosal prominence in the sigmoid colon by endoscopy, but had no other mucocutaneous vascular abnormalities. A family history was noncontributory. Under the clinical diagnosis of angiodysplasia of the sigmoid colon, he underwent an elliptical resection of the part, based on the intraoperative endoscopic findings. However, histological examination of the surgical specimen revealed a totally different picture from that seen in angiodysplasia: the thin-walled, markedly ectatic, nontortuous veins with hemorrhage were seen only just below the muscularis mucosae, around which the normal ones were shown to coexist. He has had no rebleeding for the past 3 yr. This lesion is considered to be an isolated congenital visceral telangiectasia involving veins. 

Category: general pathological conditions
Effects of standing on the induction of paroxysmal supraventricular tachycardia. To evaluate the effects of standing on induction of paroxysmal supraventricular tachycardia, electrophysiologic studies were performed in both the supine and standing positions in 22 patients with atrioventricular (AV) reciprocating tachycardia and in 11 with AV node reentrant tachycardia. AV reciprocating tachycardia was induced in 9 of the 22 patients with AV reciprocating tachycardia when they were in the supine position and in 17 when standing. The effective refractory period of the AV node markedly shortened, from 275 +/- 72 to 203 +/- 30 ms (n = 16, p less than 0.005) after standing. The effective refractory period of the accessory pathway shortened slightly, from 293 +/- 75 to 278 +/- 77 ms (n = 8, p less than 0.005), after standing. AV node reentrant tachycardia was induced in 3 of the 11 patients with AV node reentrant tachycardia when they were in the supine position and in 6 when standing. The effective refractory periods of the slow pathway and fast pathway shortened markedly, from 293 +/- 72 to 216 +/- 40 ms (n = 6, p less than 0.025) and from 416 +/- 85 to 277 +/- 50 ms (n = 10, p less than 0.005), respectively, after standing. Plasma norepinephrine levels increased during standing both in patients with AV reciprocating and in those with AV node reentrant tachycardia (n = 11, p less than 0.005, n = 8, p less than 0.005, respectively). In conclusion, standing, which is associated with increased sympathetic tone, changed the electrophysiologic properties of the reentrant circuits, facilitating induction of AV reciprocating tachycardia and AV node reentrant tachycardia. 

Category: cardiovascular diseases
Molecular surgery of the basement membrane by the argon laser. Although the argon laser is used successfully to weld a number of different tissues, the underlying chemical and cellular mechanisms for this process are not precisely defined. Consequently, a biochemical model has been developed in vitro using the well-defined extracellular matrix from the murine Engelbreth-Holm-Swarm (EHS) sarcoma. Control and experimental samples of EHS basement membranes were irradiated with a Trimedyne argon laser at 500-3,000 Joules/cm2 at 0 degrees C. The samples were diluted into cold phosphate-buffered saline and allowed to gel at 35 degrees C. The time course of the gelation reaction was followed in a spectrophotometer at 360 nm. Irradiation reduced the absorbance 7.5-15% compared to controls and was independent of the dilution over a 10-fold range. Gelation was also measured by determining the amount of protein by the Bradford assay that could be collected by centrifugation at 10,000g for 10 minutes. Argon-irradiated samples had 30-40% less protein in the precipitate than the controls. The addition of 5 mM beta-mercaptoethanol to the EHS extract blocked the effect of the laser on the gelation reaction. In addition, when gelation was carried out in the absence of calcium and magnesium, there were no differences between laser-treated samples and controls. The basement membrane proteins were separated by electrophoresis through polyacrylamide gels under denaturing plus reducing or denaturing and non-reducing conditions. No differences in the polypeptide composition were noted between irradiated and control samples using either Coomassie- or silver-staining techniques. 

Category: neoplasms
Percutaneous transhepatic cholecystostomy for acute complicated cholecystitis in elderly patients. We report our experience with percutaneous transhepatic cholecystostomy in 10 elderly patients with acute cholecystitis, complicated by empyema formation. Most of these patients has severe underlying disease, rendering them at high risk for surgical intervention. In all patients, the percutaneous procedure was followed by a rapid regression of clinical symptoms and of radiologic abnormalities. Six were considered inoperable. Three of these remain free of biliary symptoms, respectively 22, 10, and 7 months after percutaneous cholecystostomy. Three others died of nonbiliary disease 1-4 months after cholecystostomy. Three patients underwent successful elective cholecystostomy 1-5 wk after percutaneous cholecystostomy. In one patient, cholecystectomy had to be performed because of recurrence of hydrops, 1 wk after catheter removal. In our opinion, percutaneous transhepatic cholecystostomy is a safe and effective procedure in the treatment of elderly patients with acute complicated cholecystitis. It can be followed by elective cholecystectomy in good surgical candidates, or by an expectant conservative management in high surgical risk patients. 

Category: digestive system diseases
Valvular and coronary surgery in renal transplant patients. The Authors report aortic valvular replacement (AVR) and coronary artery bypass graft surgery (CABG) successfully performed in two renal transplant patients. The postoperative blood urea and creatinine levels were comparable to the preoperative values. The first patient underwent isolated AVR. The second patient had an initial AVR combined with CABG followed two years later by a further AVR for prosthetic dysfunction. For many reasons, coronary artery (CAD) and valvular diseases are not uncommon in renal transplant patients. Cardiac surgery is feasible without impairment of the renal function provided some precautions are taken, ie good mean perfusion pressure during cardiopulmonary bypass (CPB), adequate volume replacement, and selected use of mannitol and dopamine. 

Category: cardiovascular diseases
A multifocal schwannoma of the masseteric nerve causing hemicrania. A case is reported of schwannoma of the right masseteric nerve, invading the pterygopalatine fossa and the parapharyngeal space through the mandibular notch in a 61-year-old woman. The tumor in this case was composed of four various-sized interconnected nodules, simulating a string of beads. The tumor was the cause of the patient's chronic hemicrania, as confirmed by the relief from and disappearance of head pain after surgical removal of the tumor. The most important aspects of this case are the anatomic site of the schwannoma and its uncommon clinicopathologic manifestations; this tumor originated from the masseteric nerve and is the first case reported to straddle the mandibular notch. 

Category: nervous system diseases
The epilepsies: clinical implications of the international classification. From the earliest days of neurology, the classification of epileptic seizures into those generalized from the beginning and those with a definable localization in the cortex from the onset has added to knowledge about the function of the nervous system. Further elaboration of the classification of seizures into those localized to the six-layered isocortex and those whose elaboration involves regions of the brain involved with consciousness and memory has provided the basic focus for the burgeoning subspecialty of epilepsy surgery. It is increasingly apparent that the etiology of a seizure disorder is of at least equal or of greater significance than the nature of the seizures it spawns and is the product not only of localization in the nervous system but also of causative factors with implications reaching into areas of genetics, higher cortical function, and intelligence. The prognosis concerning the outcome of the epilepsy under consideration is based on all of these facets. This pathophysiological substratum, of which the seizure is only the presenting symptom, constitutes the epilepsy or epileptic syndrome on which the formulation of a rational treatment plan is based. 

Category: nervous system diseases
Intradural herniation of a thoracic disc presenting as flaccid paraplegia: case report. A case of intradural herniation of a thoracic disc in a patient with a flaccid paraplegia is described. Intradural herniation of a thoracic disc is considered a rare event. A review of the relevant patient literature revealed 14 other reports involving 28 patients. No other report has described a patient with an intradural thoracic disc herniation who developed a flaccid paraplegia. 

Category: general pathological conditions
Refractory parastomal ulcers: a multidisciplinary approach. Chronic parastomal ulcers in patients with ileostomy or colostomy stomas are unusual. Previous reports have implicated infections, fistulas, recurrent inflammatory bowel disease (IBD), pyoderma gangrenosum, and trauma. Over the past 8 years we have evaluated 10 cases of such refractory parastomal ulcers that occurred at a mean of 11 years after stomal surgery. Eight patients had had an ileostomy for IBD while two had undergone colostomy for colon cancer. Five patients with IBD were diagnosed as having pyoderma gangrenosum ulcerations. They required systemic treatment for a mean of 25 weeks to effect ulcer healing. The other five patients had either parastomal ulcers on the basis of dermatoses (contact dermatitis, eczema, or bullous pemphigoid) or contact ulcers due to face-plate pressure and parastomal dermatitis. These patients received topical treatment with healing of ulcers in a mean of 4 weeks. We conclude that parastomal ulcers occurring in patients without IBD or IBD patients without classic pyoderma gangrenosum require early dermatologic evaluation as they respond relatively quickly to appropriate local therapy. 

Category: neoplasms
The effect of long-acting somatostatin analogue on enzyme changes after endoscopic pancreatography. The effect of the long-acting somatostatin analogue, octreotide acetate (Sandostatin) on enzyme elevation after endoscopic pancreatography was studied in a prospective, randomized, double-blind trial. Sixty-three consecutive patients undergoing ERCP were randomly allocated to two group. In the control group, 34 patients received isotonic sodium-chloride, and in the treated group 29 patients received 0.1 mg of octreotide acetate subcutaneously before the pancreatography. After the endoscopy, amylase levels increased to pathological range in 15 of the controls and in 3 of the treated patients, whereas lipase levels showed a pathological rise in 17 of the controls and in 5 of the treated patients. A significant difference (p less than 0.01) was observed in the amylase and lipase changes between the two groups at 90 and 180 min after pancreatography. The enzyme levels showed at 90 min, mean +/- SD amylase: controls 540 +/- 185 units/liter, treated patients 261 +/- 108 units/liter; lipase: controls 304 +/- 98 units/liter, treated patients 198 +/- 88 units/liter. These findings suggest that the use of long-acting somatostatin analogue ameliorates the enzyme increases in the serum after endoscopic pancreatography. 

Category: digestive system diseases
Stress-related mucosal damage: review of drug therapy. The increased awareness of stress-related mucosal damage (SRMD) that accompanied the widespread use of fiberoptic endoscopy and the increased incidence of SRMD that accompanied the advances in caring for critically ill patients resulted in the recognition that the majority of patients in the intensive care unit (ICU) setting wil develop mucosal damage. Complications of gastrointestinal hemorrhage in these patients may contribute significantly to their morbidity and mortality, and the consequences of this bleeding may be more severe than the underlying predisposing conditions. Because of the importance of gastric acid in the pathogenesis of SRMD, therapy has focused on reduction of the intraluminal acid concentration. Acid neutralization, while effective, is laborious and associated with side effects. H2-receptor antagonists have been used successfully in the prophylaxis and treatment of SRMD and offer the potential for an effective parenteral as well as oral agent. They obviate the need for frequent antacid administration and eliminate some of the troubles and side effects that accompany an intensive antacid regimen. Of the available H2-receptor antagonists, cimetidine has been the most thoroughly evaluated. It is equivalent to antacids in the prevention of overt bleeding and offers the advantage of dosing flexibility, ease of administration, and a remarkable safety profile. Cimetidine has also been shown to be effective when administered by intermittent bolus infusions given every 8, 6, or 4 h or by primed continuous infusion, which has proven to be the most successful method of controlling intragastric pH. 

Category: digestive system diseases
The occurrence of motor fluctuations in parkinsonian patients treated long term with levodopa: role of early treatment and disease progression. The aim of this study is to evaluate what factors influence the risk of occurrence of motor fluctuations in patients with Parkinson's disease (PD) with particular reference to the role of early or delayed introduction of levodopa therapy during the course of the disease. One hundred twenty-five consecutive newly diagnosed patients with PD started levodopa treatment at the time diagnosis and were followed for 2 to 10 years. During follow-up, 60 patients had wearing-off or early morning akinesia. We estimated the cumulative time-dependent risk of motor fluctuation occurrence through a multivariable analysis. The risk was lower for patients with tremor-predominant PD, for those with shorter disease duration prior to levodopa, and for those who were relatively older at levodopa initiation. Our results suggest that, as far as motor fluctuations are concerned, disease prognosis is not influenced by early levodopa treatment. These observation support the introduction of levodopa as soon as there is a subjective need for the patients to maintain their level of social and work performance. 

Category: nervous system diseases
The importance of intraoperative cholangiography during laparoscopic cholecystectomy. Laparoscopic cholecystectomy (LC) using electrocoagulation was successfully performed in 56 out of 58 selected patients. Cholangiography was performed in 53 patients. Six patients had common duct stones; five were unsuspected preoperatively. After the gallbladder was removed, three patients underwent open common duct exploration. In another five cases, anatomical anomalies were discovered. Cholangiography performed via the cystic duct before any structures are divided can prevent the most serious complication--common duct injury. Cholangiography should be attempted on all patients undergoing LC. 

Category: digestive system diseases
Hormone replacement therapy. How to select the best preparation and regimen. Hormone replacement therapy is a mainstay of preventive healthcare for the maturing female population. Estrogen deficiency that comes with menopause can have serious effects and is especially important in light of the increasing life expectancy of women. Various estrogen and progesterone preparations are available, and their best application requires understanding of the different potencies and metabolic effects. Daily maintenance therapy without a drug-free interval is becoming the standard method of the 1990s. No doubt the future will bring even better delivery regimens. 

Category: cardiovascular diseases
Cecal diverticulitis presented as a cecal tumor. Seven patients diagnosed as having acute appendicitis were operated on and a cecal wall mass due to cecal diverticulitis was found. In two patients the mass could not be separated from the cecal wall and right colectomy was performed. In five patients, in whom the mass could be separated from the cecum, conservative operations (three diverticulectomies and two wedge resections) were performed, thus avoiding needless, more extensive surgery. 

Category: general pathological conditions
Push-enteroscopy for diagnosis of patients with gastrointestinal bleeding of obscure origin. Push-enteroscopy using a disinfected colonoscope was performed on 39 patients with gastrointestinal bleeding of obscure origin. Our results show that: (1) A high percentage of patients (38%) have pathological lesions responsible for bleeding located in the distal duodenum and proximal jejunum, which are readily detected by push-enteroscopy. (2) Duodeno-jejunal arteriovenous malformations (AVMs) are the most common cause for bleeding, and these lesions can be conveniently cauterized through the endoscope. (3) An efficient sequence of steps for diagnosis of patients with this problem includes push-enteroscopy when the initial EGD and colonoscopy are normal followed by small bowel radiography. Mesenteric angiography and intraoperative enteroscopy can be reserved for patients with severe bleeding when push-enteroscopy and small bowel radiography are negative. We conclude that push-enteroscopy has an important role to play in the early assessment of patients with gastrointestinal bleeding of obscure origin. 

Category: general pathological conditions
Unsuspected mitral stenosis. PURPOSE AND PATIENTS AND METHODS: We observed a series of patients in whom the diagnosis of mitral stenosis was first discovered in the echocardiography laboratory. Because of this experience, we examined the records of 152 patients with echocardiographic evidence of rheumatic mitral stenosis to determine the clinical characteristics and course of patients with unsuspected mitral stenosis as well as those factors that may have obscured the diagnosis. RESULTS: Of these 152 patients, 18 had mitral stenosis that was unsuspected clinically until the echocardiogram. These patients were elderly, with a median age of 72 years. They were all referred for echocardiography because of cardiac symptoms. Eight patients were referred for evaluation of congestive heart failure. Five patients were referred for evaluation of aortic valve disease. Three patients were referred because of cerebrovascular accidents and atrial fibrillation. The Doppler-determined mean diastolic mitral gradient ranged from 4 to 15 mm Hg (mean: 7 mm Hg). Mitral stenosis ranged in severity from trivial to very severe. Eight patients had moderate to severe mitral stenosis with estimated mitral valve areas less than or equal to 1.5 cm2. Seven had mild or trivial mitral stenosis with estimated mitral valve areas greater than 1.5 cm2. After further evaluation, two patients underwent mitral valve surgery with improvement of congestive failure. In three patients, warfarin therapy was begun to prevent emboli. Thus, five of 18 patients had a significant immediate change in therapy because of the discovery of mitral stenosis. CONCLUSION: The diagnosis of mitral stenosis may not be suspected in the presence of advanced age, other serious cardiac and medical conditions, or mechanical factors that complicate the physical examination. In these patients, mitral stenosis may be hemodynamically significant and may cause significant symptoms. 

Category: cardiovascular diseases
Abnormal liver enzyme levels. Evaluation in asymptomatic patients. Chronic elevation of serum aminotransferase levels, even in the absence of symptoms, often reflects chronic hepatitis or other significant underlying liver disease. Patients with persistently abnormal alkaline phosphatase levels may have extrahepatic biliary tract disease or a chronic cholestatic disorder. Physicians can discover unsuspected liver disease without undue risk, expense, or inconvenience to the patient by means of the following: a carefully taken history and thorough physical examination, appropriate timing of follow-up blood tests, and timely referral for percutaneous liver biopsy or endoscopic retrograde cholangiopancreatography. 

Category: digestive system diseases
Predictors of postoperative ventricular dysrhythmias: a multivariate study. Postoperative ventricular dysrhythmias were studied to document their incidence after coronary bypass grafting and to identify risk factors for their development with the hope of finding a subgroup of patients who might benefit from postoperative, prophylactic drug therapy. One-hundred-nine patients who were undergoing urgent or elective coronary bypass grafting were studied, prospectively. Twenty-five of 109 patients (23%) developed significant postoperative ventricular dysrhythmias that required counter-shock or drug intervention. Seven of eight instances of sustained ventricular tachycardia, the most serious dysrhythmia, occurred within 36 hours of operation. There was no postoperative mortality related to these dysrhythmias. Serious postoperative complications, such as stroke, hemorrhage, or myocardial infarction, were decreased in patients with ventricular dysrhythmias versus those without (8% versus 16%, p = 0.053 for the Fisher's exact test statistic). Univariate statistical analysis was performed using 15 patient variables and revealed that advanced age (p = 0.008 for the unpaired t test), failure to use an internal mammary artery conduit (p = 0.03 for the two-tailed Fisher's exact test), and development of postoperative atrial dysrhythmias (p = 0.02 for the two-tailed Fisher's exact test) were significantly more common in patients with postoperative ventricular dysrhythmias. Variables such as previous myocardial infarction, ejection fraction less than 50%, prolonged operative time, perioperative myocardial infarction, or fewer number of vessels bypassed were not significantly increased in patients with dysrhythmias (the statistical power for these "negative" results was greater than 0.8). 

Category: general pathological conditions