123rc/medical_text huggingface dataset:
Bronchial asthma. Asthma is one of the most common respiratory problems in modern industrialized countries, affecting over 5% of the population. It affects all age groups from infants to senior citizens, and mortality rates from asthma appear to be increasing during the past few years in the United States as well as in other industrialized countries. Asthma tends to occur in families, associated with other allergic disease, and may be induced by a wide variety of environmental antigens, most commonly inhaled allergens such as pollen and dust. Bronchial challenge with a specific allergen results in an early bronchospastic response with a relatively brief duration, and in a significant number of patients there is a late response with onset after 3 to 4 hours, lasting hours to days. This late response is associated with a bronchial hypersensitivity reaction, which is demonstrable by nonspecific challenge testing in the laboratory. During the period of bronchial hyperresponsiveness patients are prone to develop attacks following exposure to a wide variety of "triggers," including cold air, fumes, or cigarette smoke. The current approach to management of patients with asthma emphasizes prevention, with avoidance of specific allergens when possible, and chronic use of anti-inflammatory agents including corticosteroids and cromolyn sodium. The goal is to decrease the bronchial hyperresponsiveness. Management of the acute asthma attack consists of bronchodilator therapy, primarily with inhaled beta-adrenergic agonists, and administration of oral or systemic corticosteroids if the attack is not rapidly relieved. Additional therapeutic agents including theophylline and anticholinergics may be useful in some situations. Response to therapy during the first couple of hours in the emergency room is the most important predictor of the course of the acute attack, and patients who have not responded significantly after 2 hours of maximum therapy are candidates for hospital admission or prolonged emergency room observation. The goal of acute therapy is to wean the patient from intravenous drugs and place him or her on rapidly tapering doses of oral prednisone while initiating a vigorous program of preventive therapy. Follow-up observation, both in the office and in the patient's home, is vital and involves extensive patient education and objective testing of peak airflow. In general, the course of asthma is relatively benign compared with other obstructive airway diseases; however, significant mortality exists, especially in older patients and those with late-onset asthma.
Platelet factor 4 mRNA expression in cells from a patient with megakaryoblastic crisis of chronic myelogenous leukemia. A 61-year-old man with Philadelphia chromosome-positive chronic myelogenous leukemia developed megakaryoblastic leukemia. In the blast phase, his blast cells showed undifferentiated megakaryoblastic characteristics with no alpha-granules or demarcation membranes but with detectable platelet peroxidase (PPO) activity and surface glycoprotein (GP) IIb/IIIa. The patient has remained reasonably well for at least 12 months after blastic crisis, and 6-mercaptopurine alone has been effective in controlling leukocytosis and megakaryoblast proliferation. The expression of mRNA for platelet-specific proteins, such as GPIIb and platelet factor 4 (PF4), was studied in the patient's blast cells by the Northern blot analysis. Both GPIIb and PF4 mRNA were detected in the blast cells. Cytoplasmic maturation occurs later than the synthesis of the surface GP during megakaryocyte maturation. Therefore, PF4 mRNA expression should be a marker of mature megakaryoblasts. The PF4 mRNA expression in megakaryoblastic leukemia may indicate that a patient will have long survival and a good response to chemotherapy.
Eosinophilia-myalgia syndrome associated with L-tryptophan use. The eosinophilia-myalgia syndrome associated with the use of oral preparations of the amino acid L-tryptophan was recognized in late 1989. We describe the clinical and laboratory manifestations, pathological findings and early clinical course of 20 patients with the eosinophilia-myalgia syndrome. Prominent clinical findings included severe myalgias limiting function, fatigue, rashes, edema and weight gain, weight loss, muscle weakness and shortness of breath. Laboratory findings included eosinophilia (often marked), normal erythrocyte sedimentation rate, and elevated aldolase with normal or low creatine kinase values. On biopsy fascial inflammation was always seen consisting of lymphocytes, histiocytes and eosinophils in a perivascular distribution. Invasion of the vascular wall by lymphocytes was seen in 20%. Capillary and arteriolar endothelial cell thickening was found in most cases on electron microscopy and endothelial cell necrosis or mural invasion by lymphocytes was seen in 25% of cases. Two patients improved with no therapy. Ten patients responded to therapy with prednisone alone. Three patients have had progressive disease and one of these died. The relationship of this syndrome to previously described disease entities associated with eosinophilia is discussed.
The prevalence of retinal vascular abnormalities in children and adolescents with essential hypertension. We studied 97 children and adolescents with essential hypertension by evaluating photographs of the optic fundus and fluorescein angiography. Photographs were examined for the presence of arteriolar narrowing, tortuosity, and arteriovenous nicking. Intraobserver and interobserver variability in determination of abnormalities was low with agreement of 75% for narrowing, 90% for tortuosity, and 100% for arteriovenous nicking. The prevalence of abnormalities was 41% (95% confidence interval, 31% to 50%) for arteriolar narrowing, 14% (95% confidence interval, 19% to 21%) for tortuosity, and 8% (95% confidence interval, 5% to 11%) for arteriovenous nicking. Of 97 patients, 50 (51%) had one or more abnormality. Retinal abnormalities are relatively common in young patients with essential hypertension.
Cloning of the cDNA for human 12-lipoxygenase. A full-length cDNA clone encoding 12-lipoxygenase (arachidonate:oxygen 12-oxidoreductase, EC 1.13.11.31) was isolated from a human platelet cDNA library by using a cDNA for human reticulocyte 15-lipoxygenase as probe for the initial screening. The cDNA had an open reading frame encoding 662 amino acid residues with a calculated molecular weight of 75,590. Three independent clones revealed minor heterogeneities in their DNA sequences. Thus, in three positions of the deduced amino acid sequence, there is a choice between two different amino acids. The deduced sequence from the clone plT3 showed 65% identity with human reticulocyte 15-lipoxygenase and 42% identity with human leukocyte 5-lipoxygenase. The 12-lipoxygenase cDNA recognized a 3.0-kilobase mRNA species in platelets and human erythroleukemia cells (HEL cells). Phorbol 12-tetradecanoyl 13-acetate induced megakaryocytic differentiation of HEL cells and 12-lipoxygenase activity and increased mRNA for 12-lipoxygenase. The identity of the cloned 12-lipoxygenase was assured by expression in a mammalian cell line (COS cells). Human platelet 12-lipoxygenase has been difficult to purify to homogeneity. The cloning of this cDNA will increase the possibilities to elucidate the structure and function of this enzyme.
Use of a probe to repeat sequence of the Y chromosome for detection of host cells in peripheral blood of bone marrow transplant recipients. In situ hybridization for the Y chromosome (Y-ISH) was used to identify residual host cells in the peripheral blood of 51 recipients of sex-mismatched allogeneic marrow not depleted of T cells following conditioning with high-dose cyclophosphamide and total body irradiation (TBI). One patient who rejected the graft showed rapid reappearance of host cells after transient donor marrow engraftment. Host cells were detected at low levels in 49 of the remaining 50 patients. Host peripheral blood mononuclear cells (PBMC) decreased with time and reached a plateau at 1.0 +/- 0.2% within four weeks after transplantation, while the percentage of host granulocytes (GRAN) reached a plateau at background level. The mean absolute numbers of host PBMC or GRAN were less than 0.015 x 10(9)/L and did not vary significantly over the period studied. Neither the percentages nor the absolute numbers of host PBMC or GRAN were significantly affected by HLA-matching, TBI dose-intensity, pretransplant remission status, subsequent development of acute or chronic graft-versus-host disease or relapse after transplantation. The authors conclude that it is common to find a few residual host cells in the peripheral blood of allogeneic marrow transplant recipients, and the presence of these cells has no clinical significance.
Renal vein leiomyosarcoma. The 11th case of primary leiomyosarcoma of the renal vein is reported. Unique features of this case included concomitant resection of an isolated hepatic metastasis, intraoperative radiation therapy, and the use of electron microscopy and immunohistochemical stains in confirming the diagnosis. A review of the previously reported cases shows a tendency toward slow tumor growth and infrequent recurrence (18%). Metastases are common (82%), primarily to the lung and liver. Aggressive surgical resection and adjuvant radiation therapy, including intraoperative radiation therapy, are recommended. Adjuvant chemotherapy should be considered, although its benefits at present are unclear.
Interlocking intramedullary nailing for supracondylar and intercondylar fractures of the distal part of the femur. Thirty-seven fractures of the distal part of the femur in thirty-five patients were treated with interlocking intramedullary nailing. All fractures were nailed by a closed technique after any intercondylar extension of the fracture had been managed by reduction and stabilization with percutaneous lag-screws. Patients who had an isolated condylar fracture or a severely comminuted intercondylar fracture were treated with other types of implants. There were thirty extra-articular (type-A) fractures and seven intra-articular (type-C1 and type-C2) fractures. Postoperatively, early mobilization exercises and weight-bearing were begun. At an average duration of follow-up of 20.5 months (range, fifteen to twenty-six months), all thirty-seven fractures had healed. There were no malunions of either the supracondylar or the intercondylar fractures. Complications were infrequent and included chronic irritation from the distal screws in three patients and delayed union in one; the latter healed with two centimeters of shortening after bone-grafting. There were no infections. The functional results were assessed with the modified knee-rating system of The Hospital for Special Surgery. Thirteen knees (35 per cent) had an excellent result; twenty-two (59 per cent), a good result; and two (5 per cent), a fair result. The results correlated with the age of the patient and the presence of an intra-articular fracture. We concluded that closed interlocking intramedullary nailing is an excellent technique for both supracondylar and simple intercondylar fractures in which closed reduction and percutaneous fixation of the articular fracture is possible.
Modeling human performance in running. This paper focuses on the characteristics of a model interpreting the effect of training on athletic performance. The model theory is presented both mathematically and graphically. In the model, a systematically quantified impulse of training produces dual responses: fitness and fatigue. In the absence of training, both decay exponentially with time. With repetitive training, these responses satisfy individual recurrence equations. Fitness and fatigue are combined in a simple linear difference equation to predict performance levels appropriate to the intensity of training being undertaken. Significant observed correlation of model-predicted performance with a measure of actual performance during both training and tapering provides validation of the model for athletes and nonathletes alike. This enables specific model parameters to be estimated and can be used to optimize future training regimens for any individual.
Calcium and calcium binding in human gallstone disease. Precipitation of calcium salts from bile is important in pigment gallstone formation and may serve as a nidus for cholesterol precipitation. We compared gallbladder bile from patients with symptomatic gallstone disease (40 with cholesterol gallstones and 12 with pigment gallstones) with bile from 10 patients undergoing surgery for non-biliary tract disease. Bile from patients with gallstone disease was less concentrated, with decreased sodium, bile salt, and phospholipid concentrations, but elevated biliary calcium concentrations were not observed. The relationship between free ionized calcium and total calcium was similar in all groups, indicating no difference in calcium binding by gallstone-containing bile. We cannot exclude elevated biliary calcium level as a factor in gallstone pathogenesis, as it could be a transient event. The importance of calcium precipitation was supported by our finding that more than half of the samples were saturated or supersaturated with at least one calcium salt, calcium carbonate.
Dialysis considerations in the elderly patient. This brief review discusses several aspects of dialytic care pertinent to the older dialysis patient. Heart disease, nutrition, and the quality of life for these patients are considered.
A method for performing full-thickness, orthotopic, penetrating keratoplasty in the mouse. In an attempt to overcome the lack of well characterized, inbred, and congenic strains, as well as a paucity of immunological reagents, in rabbit and rat models, we have developed a procedure for performing full-thickness, penetrating keratoplasty in the mouse. One hundred percent of isografts (BALB/c onto BALB/c) were successful, while 83.3% of allografts (C3H onto BALB/c) failed. The use of a mouse model to study corneal graft failure will allow a critical evaluation of the role of a variety of immunological mediators in causing graft failure.
Endoscopic and histologic appearance of the gastric mucosa in patients with portal hypertension. To assess reliability of the endoscopic and histologic appearance of the gastric mucosa for diagnosing portal hypertension, 50 patients with portal hypertension and 1323 controls were studied. Endoscopic evidence of mild gastritis was seen more frequently in patients with portal hypertension than in the control group (42% vs. 13.1%, p less than 0.001). The mosaic sign was also seen more frequently in patients with portal hypertension compared with controls (14% vs. 0.9%, p less than 0.001). However, the mosaic sign was found to be nonspecific, and the sensitivity for diagnosis of portal hypertension was only 14%. Biopsy specimens from the stomach of all patients with portal hypertension and 100 controls with a normal endoscopic appearance revealed mucosal vascular congestion in 72% of patients with portal hypertension compared with 59% of controls (NS). There was no correlation between endoscopic and histologic evidence of congestive gastropathy. Similarly, there was no correlation between the severity of mucosal vascular congestion and the degree of inflammatory changes observed in the biopsy specimens; both in the control (r = 0.1) and in patients with portal hypertension (r = 0.14). It is concluded that endoscopic and histologic features of the gastric mucosa in patients with portal hypertension are of low sensitivity and nonspecific and cannot be used to diagnose portal hypertension.
Primary sclerosing cholangitis. Primary sclerosing cholangitis is a rare disease of unknown etiology. Sclerosis of the bile ducts may actually be the final result of multiple factors such as autoimmune, bacterial, congenital, drug, or viral injury. The most commonly associated diseases are ulcerative colitis and chronic pancreatitis. Except in the earliest stages of the disease, liver histologic findings are not specific. Most patients present with jaundice, pain, and pruritus, although an increasing number of asymptomatic patients with inflammatory bowel disease and abnormal liver function are being identified. Cholangiography is key to the diagnosis and is usually pathognomonic except in the unusual case where primary sclerosing cholangitis is confused with cholangiocarcinoma. Many forms of medical therapy have been tried, including antibiotics, azathioprine, cholestyramine, colchicine, cyclosporine, D-penicillamine, steroids, and ursodeoxycholic acid. To date, none of these medications has been proved to alter the course of this disease. Recent reports of ursodeoxycholic acid trials have been encouraging, but long-term results of ongoing randomized trials have yet to be published. In recent years, balloon dilatation of biliary strictures has been accomplished via endoscopic and percutaneous transhepatic approaches. However, in patients with primary sclerosing cholangitis, these nonoperative manipulations must be done repeatedly, may entail multiple general anesthetics, and are difficult to perform. We believe that a direct surgical approach to the biliary tree with long-term transhepatic stenting is indicated in selected patients with severe hilar or extrahepatic stricturing, persistent jaundice or recurrent cholangitis, and no evidence of cirrhosis. Hepatic transplantation should be reserved for patients with primary sclerosing cholangitis who have well-established cirrhosis and have not responded to other therapeutic measures.
Stroke in pediatric acquired immunodeficiency syndrome. In a 4 1/2-year period, 4 of 68 children in a longitudinal study of neurological complications of human immunodeficiency virus (HIV) infection had clinical and/or neuroradiological evidence of stroke, yielding a clinical incidence of stroke in this population of 1.3% per year. During this period, 32 subjects died, and permission for autopsy was granted in 18 of the patients, including 3 of 4 who had clinical evidence of stroke. The prevalence of cerebrovascular pathological features in our consecutive autopsy series was higher than the clinical incidence. At autopsy cerebrovascular disease was documented in 6 (24%) of 25 children with HIV infection, including all 3 children who had clinical evidence of stroke. Four patients had intracerebral hemorrhages, 6 patients had nonhemorrhagic infarcts, and 3 had both. Hemorrhage was catastrophic in 1 child and clinically silent in 3 children, all of whom had immune thrombocytopenia. One child had an arteriopathy that affected meningocerebral arteries. In another child, the arteries of the circle of Willis were aneurysmally dilated. Two children had coexisting cardiomyopathy and subacute necrotizing encephalomyelopathy with vascular proliferation. These results suggest that stroke should be considered when children with HIV infection develop focal neurological signs.
Endocarditis due to ampicillin-resistant nontyphoid Salmonella: cure with a third-generation cephalosporin. A case of ampicillin-resistant salmonella bacteremia complicated by endocarditis in a 78-year-old man is presented. Previous rheumatic valvular heart disease and the lack of response to initial treatment with chloramphenicol prompted us to consider this diagnosis. There was a good clinical response after treatment with ceftriaxone alone and corresponding improvement on the echocardiogram. This case demonstrates the possible endovascular complications of salmonella bacteremia in elderly people and that endocarditis should be included among the invasive infections due to ampicillin-resistant Salmonella that could potentially be treated with the newer cephalosporins.
Frontal lobe utilization behavior associated with paramedian thalamic infarction. Disinhibited, exaggerated responses to objects and environmental cues (utilization behavior) occur predominantly with frontal lobe damage. We report a striking example associated with paramedian thalamic infarction suggesting a thalamofrontal component to environmental interactions that require inhibition, self-monitoring, and cognitive flexibility.
The changing direction of nystagmus in acute Meniere's disease: pathophysiological implications. The direction(s) and pathophysiologic basis of nystagmus during an acute attack of Meniere's disease have been subject to much debate in the world literature. Clinical recordings from two patients whose nystagmus was captured near the very beginning of the acute vertiginous episode are presented. Previous clinical observations in Meniere's disease, experimental animal models concerned with initiation of peripheral nystagmus, and the phenomenon of recovery are discussed.
Transhepatic portal vein catheterization for localization of insulinomas: a ten-year experience. One of the most important factors in the management of insulinomas is the ability to localize the tumor accurately either before or during surgery. We prospectively carried out transhepatic portal venous sampling (THPVS) for tumor localization in 35 of 40 patients with organic hyperinsulinism during a 10-year period. In 32 patients who underwent THPVS and in whom a single tumor was subsequently identified surgically, the maximal insulin gradient was located in the vicinity of the tumor in 100% of cases. Specific regionalization of the tumor on the basis of the site of the maximal insulin gradient to one of three regions (the tail, the body/neck region, and the head/uncinate region) gave a sensitivity of 81% and a specificity of 91%. In contrast, the use of specific cutoff levels for the insulin gradient as a guide to the presence of a tumor in one of these three regions did not increase the accuracy, leading instead to a significant loss of sensitivity with no comparable increase in specificity. There were no major complications from the procedure in any patient. The initial use of computed tomographic/ultrasound scanning and selective angiography localized only 46% of tumors, whereas subsequent THPVS led to the accurate preoperative localization of 100% of all tumors submitted to surgery. Although the surgeon would have identified 81% of the tumors correctly at operation, in 19% (n = 6) he would have failed. Four tumors were in the uncinate and two were in the head. It seems that in patients with proved or established organic hyperinsulinism, THPVS may continue to be of value, if only to regionalize the tumor, especially those in the pancreatic head and uncinate process so as to preclude noncurative operations on the body and tail of the pancreas.
Eosinophilia-myalgia syndrome associated with L-tryptophan ingestion. Analysis of four patients and implications for differential diagnosis and pathogenesis Four patients fulfilling the case definition for eosinophilia-myalgia syndrome are described, including one whose disease began in 1986. Each displayed a variety of symptoms: one suffered principally from myalgia and recovered spontaneously on discontinuation of L-tryptophan therapy; one exhibited progressive sclerodermiform skin changes, neuropathy, and myopathy; a third had prominent neuromuscular disease and sclerodermiform skin changes; and the fourth experienced profound weight loss, an axonal polyneuropathy, and perivascular lymphoid infiltrates simulating a lymphoma. Evidence of T-cell activation was present in peripheral blood and affected tissues during the clinically active progressive phase of disease. Among other manifestations pleural effusion, cutaneous vasculitis, joint contractures, and bloody diarrhea were observed. A history of L-tryptophan ingestion should be sought in patients with myalgia, fatigue, or the above outlined symptoms.