123rc/medical_text huggingface dataset:
Immune response of peripheral blood mononuclear cells to HBx-antigen of hepatitis B virus. The hepatitis B virus genome encodes a transcriptional transactivator protein designated HBxAg. We have investigated whether this antigen is a target structure for human T-lymphocytes. Using recombinant HBxAg protein, we found HBxAg-specific stimulation of peripheral blood mononuclear cells in patients with acute hepatitis B virus infection (6 of 6) and chronic hepatitis B virus infection (6 of 17) but not in healthy individuals. With HBxAg-specific synthetic polypeptides, several T-cell epitopes were identified. Most were located in the carboxyterminal half of the HBxAg protein. Five T-cell clones specific for a T-cell epitope located at the carboxyterminal region of HBxAg were established and found to belong to the CD2/CD4-positive, CD8-negative subtype. These data establish for the first time HBxAg as an antigen in the cellular immune response.
Expression of neural cell adhesion molecule in normal and neoplastic human neuroendocrine tissues. The neural cell adhesion molecule (N-CAM) is a group of cell surface glycoproteins involved in direct cell--cell adhesion. N-CAM expression in normal and neoplastic tissues was examined with specific antibodies and oligonucleotide probes by immunohistochemistry and in situ hybridization. Most neuroendocrine cells and tumors with secretory granules expressed N-CAM protein and mRNA. Parathyroid adenomas (4) were somewhat unusual, because N-CAM mRNA, but not protein, was detected in some of these benign neoplasms. Most non-neuroendocrine cells and tumors did not express N-CAM, although uterine smooth muscle and an adrenal cortical carcinoma were both positive. Western blots disclosed proteins of 180, 140, and 120 kd in normal adult brain, whereas two pheochromocytomas, a null cell adenoma, and a gastrinoma had proteins of approximately 180 and 140 kd. These results indicate that N-CAM protein and mRNA are widely expressed in neuroendocrine cells and neoplasms. N-CAM oligonucleotide probes as well as antibodies against N-CAM can be used as broad-spectrum neuroendocrine markers. In addition, these molecular probes can be used to examine the role of N-CAM in the development and regulation of neuroendocrine tissues.
Genetics of cerebrovascular disease. Stroke is a complex disease, with both genetic and environmental factors having a role in its pathogenesis. A review of past studies shows some evidence of genetic influences in the development of stroke. This is supported by studies of cardiovascular disease, which indicate major genetic influences at several levels including the development of risk factors. New approaches to phenotypic classifications, patient ascertainment, and genetic analysis will stimulate research into the role of genetics in cerebrovascular disease.
Appraisal of gut lavage in the study of intestinal humoral immunity. Direct investigation of intestinal humoral immunity requires collection of intestinal secretions or mucosal biopsy specimens, or both. A non-invasive technique of gut lavage, with a polyethyleneglycol electrolyte lavage solution as a means of collecting intestinal secretions for immunoglobulin and antibody studies, was evaluated. Fifty patients were studied--25 immunologically normal patients or volunteers, 15 patients with untreated coeliac disease, and 10 patients with active Crohn's disease. Protease inhibitors were added promptly to samples to prevent proteolysis of immunoglobulin content. Treated lavage samples were assayed by enzyme linked immunosorbent assay for immunoglobulin and antibody content. Studies of serial lavage specimens showed that early, faecally contaminated specimens contained negligible quantities of immunoglobulin, but once the specimens became clear a steady state was reached, with little variation in immunoglobulin content between serial specimens and with a uniform dilution (around 20%) of the ingested polyethyleneglycol. Gut lavage fluid IgA was predominantly secretory, comprising 92%, 81.6%, and 76.7% respectively of the total IgA gut lavage fluid content in the control, coeliac, and Crohn's groups. High values of total IgM and IgA and IgM antigliadin antibodies were detected in the coeliac group, and high values of IgG in the Crohn's disease group. This method of gut lavage is not only an effective bowel cleanser, but also a noninvasive means of obtaining intestinal secretions for the study of humoral immunity in gastrointestinal disease.
Subsite distribution and incidence of colorectal cancer in New Zealand, 1974-1983. The purpose of this study was to examine changes in subsite distribution and incidence of colorectal cancer within different age groups. Registration of colorectal cancer by the National Cancer Registry of New Zealand approached 100 percent by 1974. The present study was based on 15,395 individuals aged 25 years and over and registered for colorectal cancer between 1974 and 1983. Subsite distribution (right colon, left colon, rectum) for different age groups (25-49, 50-69, 70+ years) was significantly skewed, with an excess of right colonic cancer in individuals aged 25-49 years and 70+ years. This right colonic excess was accompanied by a relative reduction in left colonic cancer. Age adjusted incidence rates for the periods 1974-78 and 1979-83 were compared and stratified by age group and subsite. Incidence rates increased in all subsites in individuals aged 50+ years. This was particularly evident for right sided cancer in the elderly of both sexes. There was a marked reduction in the incidence of left colonic cancer and rectal cancer in individuals under 50 years. In contrast, the incidence of right colonic cancer remained relatively stable in young individuals. Time trend studies indicate that the skewed subsite distribution of large bowel cancer in different age groups may increase with time and is probably due to varying etiological factors acting on different cohorts.
Bolus, front-loaded, and accelerated thrombolytic infusions for myocardial infarction and pulmonary embolism. Thrombolytic therapy decreases mortality in patients with acute myocardial infarction and is now widely used in such patients. The choice of which thrombolytic agent to use in such patients, either streptokinase or recombinant tissue plasminogen activator (rt-PA), is based on regional preferences. The standard dose of streptokinase is 1.5 million units over 60 min, and the dose of rt-PA that is commonly used is 100 mg over 3 h. Experiments in animals have demonstrated that rt-PA produces continuing thrombolysis after it is cleared from the circulation and that thrombolysis is both increased and accelerated and bleeding is reduced when rt-PA is administered over a short time period. Based on these studies, there have been a number of recent trials examining alternative dosage regimens for rt-PA (bolus, front-loaded, and accelerated) in patients with myocardial infarction. To date, there is no convincing evidence that such regimens are superior to the more traditional rt-PA regimen. Future randomized trials will determine whether attempts to optimize rt-PA regimens will result in more efficacious treatment regimens. Interest in the use of thrombolytic therapy for patients with acute pulmonary embolism has been rekindled. The traditional 12- to 24-h regimens of streptokinase and urokinase are not optimal because of their logistic complexity and associated hemorrhagic complications. Clinical studies have demonstrated that rt-PA, 100 mg over 2 h, is an effective thrombolytic agent in patients with acute pulmonary embolism. In a recent double-blind trial in patients with acute pulmonary embolism, rt-PA, 0.6 mg/kg infused over 2 min, improved pulmonary perfusion. This bolus regimen is attractive because it is simple to administer. Future studies will compare the relative efficacy and safety of these two rt-PA regimens in patients with acute pulmonary embolism.
Effects of site-specific mutations on biologic activities of recombinant human IL-6. To examine structure-activity relationships of human IL-6, we have determined the effects of specific mutations on the biologic activity of a human rIL-6 expressed in bacteria. Three types of mutants were examined: 1) a variant that contains serines in place of the four naturally occurring cysteines; 2) a series of cysteine-containing deletion mutants, each having a single internal 20 amino acid deletion; and 3) a cysteine-free variant containing a single 20 amino acid deletion. The mutants of the second type constitute a set of nonoverlapping, adjacent deletions spanning amino acids 4 through 183 of the 184 amino acids in natural human IL-6. All of the mutants were expressed, along with the full length, cysteine-containing analogue, in Escherichia coli as fusion proteins, joined to beta-galactosidase through a collagen linker. This system allows microgram quantities of the rIL-6 variants to be partially purified from small bacterial cultures without chromatographic or refolding steps. Each of the rIL-6 variants was released from the beta-galactosidase fusion protein with collagenase, and the recovered rIL-6 was quantitated by laser densitometry of Coomassie-stained, SDS polyacrylamide gels. The sp. ac. of each of the rIL-6 variants was determined using four assays: induction of IgM secretion from an EBV transformed human B cell line, induction of fibrinogen secretion from a human hepatoma cell line, induction of fibrinogen secretion from a rat hepatoma cell line, and induction of proliferation of a murine hybridoma cell line. Replacement of cysteines with serines reduced activity relative to cysteine-containing rIL-6 to about 20% in the rat hepatoma assay and about 3% in the mouse hybridoma assay, whereas activity in both of the human cell lines was reduced to less than 0.1%. These data suggest that the murine and rat cell lines are less selective than the human cell lines in their requirements for recognition of biologically active IL-6. Each of the deletions, except that of amino acids 4 through 23, resulted in loss of activity in all four assays. These results suggest that the information necessary for activity is not contained within any one portion of the IL-6 molecule, but rather that multiple segments of the protein are required for each of the biologic activities that we tested.
Prophylactic sclerotherapy for esophageal varices: long-term results of a single-center trial. Survival after prophylactic sclerotherapy was assessed in a single-center study involving 99 cirrhotic (41 alcoholic) patients enrolled over 8-yr. The wedged hepatic vein pressure gradient was measured; those with pressure greater than or equal to 12 mm Hg were randomized to receive sclerotherapy or no treatment. The rest were not randomized. Patients in all three groups who bled were treated with emergency endoscopy and sclerotherapy. Stratification according to presence of ascites was also undertaken. Median follow-up was 61 mo (range = 14 to 107 mo). Survival among unrandomized patients was significantly longer than among randomized patients (p less than 0.006), but there was no significant difference between those treated by sclerotherapy and the controls (p = 0.27). Alcoholic cirrhotic patients undergoing sclerotherapy had better 2-yr survival than did the controls (80% vs. 43%; p = 0.09), but this benefit was not sustained at 5 yr. Survival in the nonalcoholic patient groups was identical. Only 10 of 50 deaths were caused by variceal bleeding. Forty-eight percent of patients with large varices bled, compared with 20% of patients with small varices. Wedged hepatic vein pressure less than 12 mm Hg accurately identified alcoholic patients at low risk of variceal bleeding but not nonalcoholic patients. Only four episodes of variceal bleeding were attributable to elective sclerotherapy. We conclude that in our population, prophylactic sclerotherapy alone does not improve survival. The discrepancy in survival between alcoholic and nonalcoholic cirrhotic patients suggests that factors other than variceal hemorrhage may be responsible for the difference.
A case of cerebrotendinous xanthomatosis. II: The sterol content of a cataractous lens. The cholestanol content of a cataractous lens nucleus from a patient with cerebrotendinous xanthomatosis (CTX) was quantified by gas chromatography-mass spectrometry and found to be 0.27 micrograms per mg freeze-dried lens tissue. The cholestanol-cholesterol ratio of 1.7% in the lens nucleus was similar to that in the serum of the CTX patient. The cholestanol content and cholestanol-cholesterol ratio in the CTX lens were approximately four-fold and six-fold greater respectively than the mean levels found in three senile cataractous lens nuclei analysed simultaneously for comparative purposes.
Idiopathic intracranial hypertension without papilledema. We describe 10 patients with idiopathic intracranial hypertension who did not have papilledema. Idiopathic intracranial hypertension without papilledema, although rarely reported, may well be a clinically important headache syndrome. Historical and demographic features of patients with idiopathic intracranial hypertension without papilledema are similar to those of patients with papilledema. Obese women with chronic daily headache and symptoms of increased intracranial pressure, pulsatile tinnitus, history of head trauma or meningitis, an empty sella on imaging studies, or a headache that is unrelieved by standard therapy should have a diagnostic lumbar puncture. Findings from laboratory and neurologic investigations are normal in most patients with idiopathic intracranial hypertension without papilledema. Initial management should include removal of possible inciting agents, weight loss if applicable, and standard headache therapy. Lumbar puncture and diuretic therapy should precede a trial of corticosteroids. Surgery (lumboperitoneal or ventriculoperitoneal shunt or perhaps optic nerve sheath fenestration) may be indicated for prolonged incapacitating headache that is not responsive to medical management or lumbar puncture.
Acute lower respiratory tract infection due to virus among hospitalized children in Dhaka, Bangladesh. The nature of acute lower respiratory tract infection (ALRI) in hospitalized children and of the associated viral agents was assessed in a study of 601 children less than 5 years old over a 24-month period. Of these children, 80% were less than 24 months of age and the ratio of boys to girls was 1.7:1. Pneumonia (86.5% of cases) was the most frequently observed clinical manifestation. Shedding of virus was detected in 21.1% of the children; the highest rate occurred in infants 0-5 months old (27%) as compared with a rate of only 12.5% in children 25-60 months old. Virus was detected in 33.3%, 32.8%, 21.2%, and 20% of the cases of tracheobronchitis, bronchiolitis, pneumonia, and croup, respectively. Among the viruses detected, 78% were respiratory syncytial virus (RSV) (91% of infections with this virus occurred in children less than 2 years old) and 14.4% were influenza virus types A and B. Of the RSV infections, 61% occurred in infants less than 1 year old. The case-fatality rate was 6.8% overall and was 4.8% in virus-associated cases. No consistent pattern of seasonal occurrence of viral infections was discerned. RSV was detected throughout the year, with increased prevalence from January to April.
Endocrine function in children with human immunodeficiency virus infection. We sought to determine if failure to thrive in pediatric patients with the human immunodeficiency virus could be explained based on endocrine dysfunction. Fourteen human immunodeficiency virus-infected pediatric patients, all of whom had adequate nutritional status, underwent endocrine evaluation. Growth hormone and cortisol responses to glucagon stimulation were adequate. Despite this, eight of the 12 subjects had low somatomedin C levels. Although all patients were clinically and biochemically euthyroid, 36% (5/14) demonstrated elevated baseline and peak thyrotropin levels in response to thyroid releasing hormone, suggesting a state of compensated hypothyroidism. Although the importance of these findings is unclear, it is possible that subtle alterations of thyroid regulation may contribute to failure to thrive in some pediatric patients infected with human immunodeficiency virus and may represent a potentially correctable defect.
Leukaemia complicating treatment for Hodgkin's disease: the experience of the British National Lymphoma Investigation. OBJECTIVE--To determine the incidence of and risk factors for the development of secondary acute leukaemia and myelodysplasia in patients treated in British National Lymphoma Investigation's studies of Hodgkin's disease since 1970. PATIENTS--2676 Patients entered into Hodgkin's disease studies between February 1970 and November 1986. Data accrued up to November 1988 were analysed, ensuring a minimum follow up period of two years. DESIGN--Retrospective analysis of multicentre trial data by case-control and life table methods. RESULTS--17 Cases of secondary leukaemia were recorded in this group of 2676 patients, giving an overall risk at 15 years of 1.7%. The risks of leukaemia after chemotherapy alone and chemotherapy with radiotherapy were not significantly different. The risk of leukaemia increased sharply with the amount of treatment given as measured by the number of attempts at treatment. The 15 year risks of leukaemia were 0.2%, 2.3%, and 8.1% for patients receiving one, two, or three or more attempts at treatment. The highest risk, 22.8% at 15 years, was observed in patients treated with lomustine (CCNU), and a case-control study suggested that this was an independent risk factor. The risk of secondary leukaemia was largely related to the overall quantity of treatment, although exposure to lomustine seemed to be an important risk factor. Treatment with both drugs and radiation was not more leukaemogenic than treatment with drugs alone. The greatest risk of secondary leukaemia was seen in multiply treated patients who were unlikely to be cured of Hodgkin's disease. CONCLUSIONS--Avoidance of secondary leukaemia should be a minor factor in the choice of treatment for Hodgkin's disease.
Extensive vulvar and vaginal varicella necessitating abdominal delivery. Maternal varicella occurs in fewer than five per 10,000 pregnancies in the United States. A case is reported in which markedly painful, extensive vulvar and vaginal ulcers prevented cervical examination, and cesarean section was performed with the patient under general anesthesia.
Tissue dose estimates following the selective uptake of 125IUdR and other radiolabelled thymidine precursors in resistant tumours. For the purposes of evaluation of the therapeutic potential of the radiohalogenated thymidine analogue 125IUdR, estimation of the radiation dose to the tumour cells and normal tissues is important. To determine the dose to any tissue from the radionuclide 125I is not simple, since the major emissions are very short-range Auger electrons. The cytotoxicity of 125I is strongly dependent on the position of the decay relative to the DNA, the principal target for cell sterilization. Estimates of the cytotoxicity of 125I based on the traditional MIRD recommended formulation (ICRU Report 32, 1979) may produce gross underestimates if it is incorporated into the DNA via the thymidine precursor 125IUdR. In this work, tissue count and autoradiography (ARG) data from studies by Bagshawe et al were used to estimate tissue doses following the administration of 125IUdR to LS174/T (a colorectal carcinoma) and CC3 (a choriocarcinoma) tumour-bearing animals, after a hydroxyurea block of the normal tissue turnover. The tumour cell toxicity is estimated from ARG data on the degree of 125I incorporation into the cell nucleus. Major drawbacks with 125I for this type of therapy are the long 60-day half-life, leading to radiological and waste disposal problems and the extreme short range of the radiotoxic effects. Possible alternative radiohalogens, 13I, 77Br, 131I and 211At, are suggested in place of 125I in the thymidine analog iododeoxyuridine. Dose calculations are performed and cytotoxicities estimated on the assumption that their biological retention characteristics are the same as for 125IUdR.
Combined vesicovaginal-ureterovaginal fistulas associated with a vaginal foreign body. A case is presented of vesicovaginal-ureterovaginal fistulas associated with a neglected vaginal foreign body. The patient complained of a foul-smelling vaginal discharge and was found to have a 4-cm hard vaginal mass on examination. Urinary incontinence developed subsequently. Examination under anesthesia was performed, and an aerosol deodorant cap was operatively removed from her posterior vagina/perirectal space. Subsequent work-up demonstrated the presence of both a vesicovaginal fistula and a right ureterovaginal fistula. The patient underwent a combined vaginal repair of the vesicovaginal fistula and abdominal ureteroneocystostomy. The frequency, types, etiology, and treatment of genitourinary fistulas are reviewed with particular attention to those associated with a vaginal foreign body.
Epidural anaesthesia for labour and caesarean section in a parturient with a single ventricle and transposition of the great arteries. We describe a case of a 29-year-old parturient with a single ventricle and transposition of the great arteries who had lumbar epidural analgesia/anaesthesia with a local anaesthetic for labour, emergency Caesarean section and postoperative pain. Her outcome and that of her baby was successful. The anaesthetic techniques used in other parturients with similar congenital cardiac anomalies are reviewed.
A prospective analysis of intramuscular meperidine, promethazine, and chlorpromazine in pediatric emergency department patients. STUDY OBJECTIVE: To examine physiologic responses and efficacy of 2, 1, and 1 mg/kg IM meperidine, promethazine, and chlorpromazine (MPC), respectively, in children. DESIGN: Prospective, unblinded trial. SETTING: A university and community emergency department. PATIENTS: Sixty-three hemodynamically and neurologically stable children. INTERVENTION: Single dose of IM MPC. MEASUREMENTS AND MAIN RESULTS: Serial respirations, heart rate, arterial systolic blood pressure, oxygen saturation, and Glasgow Coma Scale were measured at 30-minute intervals. Effectiveness was assessed by two independent observers using separate visual analog scales for cooperation and sedation. Times to sleep (27 +/- 24 minutes), sitting upright (103 +/- 87 minutes), ED discharge (4.7 +/- 2.4 hours), eating (11 +/- 7.9 hours), and normal behavior (19 +/- 15 hours) were acceptable. Minor, but statistically significant, changes in respiration rate (-1.9 +/- 0.4), heart rate (+4.5 +/- 1.8), oxygen saturation (-0.7 +/- 0.3%), and Glasgow Coma Scale (-2.5 +/- 0.6) occurred for 120 minutes after MPC. No serious complications or resuscitation were required. Mean visual analog scale scores were 5.0/10.4 or more in 71% of cases, with interobserver agreement very good (cooperation, r = .79; effectiveness, r = .80). Twenty-nine percent of children were judged insufficiently sedated. CONCLUSION: IM MPC is a safe and generally effective agent for ED procedures in selected children.