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131.
Two tumour cell clones, 6D1 and 4C2 cells, which are defective both in the major histocompatibility gene complex (MHC) class I expression and in the endogenous antigen presentation, are recovered with interferon (IFN)-gamma treatment. The present study describes the ultrastructure of these cells by using scanning and transmission electron microscopy in relation to the effect of IFN-gamma treatment. The general morphology of these cells was found to be similar to each other and comparable to that of a tumour cell clone, 4A1 cells, of the same origin, normal in MHC class I expression; they exhibited a fibroblast-like appearance and had many blebs on all the cell surfaces, with desmosome-like junctions between cells. On IFN-gamma treatment, surface fine blebs appeared less, and mitochondria became more densely stained. Expression of MHC class I molecules on the cell surface was much higher in the IFN-gamma treated 6D1 and 4C2 cells than in untreated cells, when estimated by immunoelectron microscopy. The addition of an epitope peptide to these cells did not enhance the class I expression, which differed from other antigen presentation-defective cells such as RMA-S cells, nor change the cell surface morphology.  相似文献   
132.
OBJECTIVE: To characterize drug-taking behavior using continuous electronic monitoring in an AIDS clinical trial. SETTING: This was a substudy of AIDS Clinical Trials Group (ACTG) protocol 175, a phase II/III study of dideoxynucleoside monotherapy versus combination therapy in asymptomatic HIV-positive subjects. Participants were required to comply with regimens containing zidovudine, zalcitabine and didanosine, or matching placebos; the total daily pill count was 16. DESIGN: For participants at two ACTG 175 sites, electronic devices were used to monitor drug-taking behavior of all study medications over a period of approximately 90 days. MEASUREMENTS: Four indices of drug-taking behavior were calculated and their distributions and relationship to the prescribed regimen were examined. RESULTS: Data from 41 subjects were analyzed. Of the prescribed doses of zidovudine, zalcitabine and didanosine, 88, 84 and 82%, respectively, were taken. Of these, 55, 66 and 79%, respectively, were taken at the prescribed dosing frequency. The median percentage of days on which participants failed to take any of the doses was 2-5%. There was a trend towards lower adherence in the combination therapy arms compared with those assigned to receive monotherapy. In this analysis, older patients demonstrated better adherence, although patient characteristics, in general, were poorly predictive of adherence. CONCLUSION: Drug-taking behavior for all three active study medications differed from that prescribed. One result of this erratic adherence was that study participants sustained little antiretroviral effect during more than 25% of the monitoring period.  相似文献   
133.
We previously described a high incidence of digit/limb anomalies in the offspring of A/J mice subjected to surgery on day 12.5 postconception (p.c.), but not in the offspring of untreated control mice. To investigate the cause of these defects, we compared the offspring of mice in experimental groups involving adrenalectomy, sham adrenalectomy, blood sampling, and anesthesia with the offspring of control mice. All treatments significantly reduced fetal weight and increased resorptions as compared with the controls. The highest incidence of digit anomalies occurred in the offspring of dams from which blood samples had been drawn on days 12.5, 14.5, and 15.5 p.c. The incidence of isolated cleft palate was also increased in the offspring of mice that had been subjected to blood sampling. We conclude that digit anomalies in the offspring of A/J mice result from fetal vascular disruptive phenomena subsequent to maternal blood loss induced hypovolemia and hypoperfusion to the uterus and placenta as has been suggested for uterine vascular clamping, misoprostol, chorionic villus sampling, and cocaine teratogenesis. The etiology for cleft lip in these mice may involve mechanisms unrelated to uterine/placental hypoperfusion.  相似文献   
134.
BACKGROUND: Investigations concerning the severity of respiratory syncytial virus (RSV) disease as related to (1) RSV type and genotype determined respectively by PCR and restriction enzyme analysis and (2) interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) values in samples of nasopharyngeal secretion (NPS) have not been previously reported. METHODS: We prospectively studied 105 RSV infections in the lower respiratory tract of infants and young children admitted to a pediatric department in Copenhagen during three winter seasons, 1993, 1994 and 1995. RSV strains were typed and genotyped, respectively, by PCR and nucleic acid restriction analysis and correlated to the severity of the disease. The ratio IL-6:TNF-alpha, determined from IL-6- and TNF-alpha values in samples of NPS, was related to the severity of the disease. Concentrations of IL-6 and of TNF-alpha were determined in serum samples taken during 5 weeks after the onset of illness. RESULTS: Type B infections produced more severe disease than did type A infections, as assessed on the length of the hospital stay, use of respiratory support and the presence of an infiltrate on a chest radiograph. This difference was age-related. It was observed in infants 0 to 5 months old, but not in older age groups. Type B genotype B1122 produced more severe disease than type A genotype A2311 in infants 0 to 11 months old. Increased serum concentrations of IL-6 and TNF-alpha were detected in samples taken 1 to 2 days after the onset of illness. Whereas TNF-alpha serum concentrations remained high, IL-6 serum concentrations decreased during the following 3 to 4 weeks. The IL-6:TNF-alpha ratio in samples of NPS was related to the severity of the disease. A high ratio was related to a low severity. CONCLUSIONS: The severity of disease in patients admitted with acute RSV infections can be correlated to the RSV type as determined by PCR, to the RSV genotype as determined by nucleic acid restriction analysis and to the ratio IL-6:TNF-alpha in NPS.  相似文献   
135.
The aim of this study was to determine whether suckling-induced prolactin (PRL) levels were modified when milk ejection was impaired. Milk ejection impairment was achieved in two experimental models: a) depriving the dam of sleep during suckling and b) increasing the nonsuckling intervals in lactating dams. Sleep deprivation blocked milk ejection and enhanced suckling-induced PRL levels in dams that had been previously separated from their pups. When milk ejection is blocked in litter-deprived dams, mammary glands are not evacuated and they remain engorged. Suckling stimuli were not the cause of the difference in suckling-induced serum PRL levels in control and sleep-deprived dams. The engorgement of the mammary glands may play a role, as a maximum suckling-induced PRL increase was not observed in nonseparated SD dams with nonengorged mammary glands. Moreover, suckling-induced PRL levels were decreased when engorged mammary glands of SD dams were evacuated through an oxytocin injection. A parallel increase between suckling-induced PRL levels and mammary gland weight was observed in the experiments in which milk ejection was impaired through an increase in the intervals of nonsuckling, providing additional support for a relationship between mammary gland engorgement and the regulation of suckling-induced PRL levels.  相似文献   
136.
The effect of cholesterol feeding (3 g/day) on bile acid synthesis was examined in 10 New Zealand white rabbits (NZW), 8 Watanabe heterozygous and 10 homozygous rabbits with partial and complete deficiencies of LDL receptors. After 10 days of cholesterol feeding, bile fistulas were constructed and bile acid pool sizes were measured. Cholesterol feeding increased plasma and hepatic cholesterol levels in all rabbit groups. Baseline bile acid pool sizes were smaller (P < 0.01) in heterozygotes (139 +/- 3 mg) and homozygotes (124 +/- 30 mg) than NZW rabbits (254 +/- 44 mg). After feeding cholesterol, bile acid pool sizes doubled with increased cholic acid synthesis in NZW and, to a lesser extent, in Watanabe heterozygous rabbits but not in homozygotes. Baseline cholesterol 7alpha-hydroxylase activity in NZW and heterozygotes declined 69% and 53% (P < 0.001), respectively, after cholesterol feeding. Sterol 27-hydroxylase activity reflecting alternative bile acid synthesis increased 66% (P < 0.01) in NZW and 37% in Watanabe heterozygotes but not in homozygotes after feeding cholesterol. Bile fistula drainage stimulated cholesterol 7alpha-hydroxylase activity but not sterol 27-hydroxylase activity in all three rabbit groups. These results demonstrated that dietary cholesterol increased hepatic sterol 27-hydroxylase activity and alternative bile acid synthesis to expand the bile acid pool and inhibited cholesterol 7alpha-hydroxylase in NZW and in Watanabe heterozygous rabbits but not in homozygotes with absent hepatic LDL receptor function. Thus, in rabbits, sterol 27-hydroxylase is up-regulated by the increased hepatic cholesterol that enters the liver via LDL receptors whereas cholesterol 7alpha-hydroxylase is controlled by the circulating hepatic bile acid flux.  相似文献   
137.
Little is known about the stability of fumonisins in corn-based foods during heating. This study investigated the effects of canning, baking, and roasting (dry heating) processes on the stability of fumonisins in artificially contaminated and naturally contaminated corn-based foods. All samples were analyzed for fumonisin levels by both a commercial enzyme-linked immunosorbent assay (ELISA) and a high-performance liquid chromatographic (HPLC) method. Canned whole-kernel corn showed a significant (P < or = 0.05) decrease in fumonisins by both ELISA (15%) and HPLC (11%) analyses. Canned cream-style corn and baked corn bread showed significant (P < or = 0.05) decreases in fumonisin levels at an average rate of 9% and 48%, respectively, as analyzed by ELISA. Corn-muffin mix artificially contaminated with 5 micrograms of fumonisin B1 (FB1) per g and naturally contaminated corn-muffin mix showed no significant (P < or = 0.05) losses of fumonisins upon baking. Roasting cornmeal samples artificially contaminated with 5 micrograms of FB1 per g and naturally contaminated cornmeal samples at 218 degrees C for 15 min resulted in almost complete loss of fumonisins.  相似文献   
138.
This article summarizes the results of a combined analysis from two identical multicenter clinical trials that investigated the efficacy and safety of sertraline versus placebo for treating panic disorder. Patients with panic disorder who were treated with sertraline had a statistically significant reduction in the mean number of panic attacks per week (the primary efficacy measure) as compared with placebo (4.8 vs. 2.5, p < .001). Sertraline-treated patients also showed greater improvement that was statistically significant on several ratings of panic disorder symptomatology and functioning. The design characteristics, clinical rating measures, and outcome measures in these trials included most of the features deemed essential by Shear and Maser (1994) in their summary of the NIMH Consensus Conference for the development of standardized assessments for panic disorder. This suggests that the NIMH Consensus Conference played a key role in developing successful multicenter pharmacological treatment studies, such as this one that ultimately demonstrated that sertraline was an effective treatment for panic disorder.  相似文献   
139.
Epidermal growth factor (EGF) is a potent mitogen for normal mouse mammary epithelial cells grown in primary culture. EGF activation of the EGF-receptor (EGF-R) induces intrinsic tyrosine kinase activity which results in EGF-R autophosphorylation and tyrosine phosphorylation of other intracellular substrates involved in EGF-R signal transduction. Genistein and erbstatin are anticancer agents which have been shown to be potent tyrosine kinase inhibitors. However, the effects of these compounds in modulating EGF-dependent normal mammary epithelial cell proliferation is presently unknown. Therefore, studies were conducted to determine the effects of genistein and erbstatin on EGF-dependent proliferation, and EGF-R levels and autophosphorylation in normal mouse mammary epithelial cells grown in primary culture and maintained in serum-free media. Chronic treatment with 6.25-100 microM genistein or 1-16 microM erbstatin significantly decreased EGF-dependent mammary epithelial cell proliferation in a dose-responsive manner. However, the highest doses of genistein (100 microM) and erbstatin (16 microM) were found to be cytotoxic. Additional studies showed that acute treatment with 6.25-400 microM genistein did not affect EGF-R levels or EGF-induced EGF-R autophosphorylation, while acute treatment with 1-64 microM erbstatin caused a slight reduction in EGF-R levels, but had no effect on EGF-dependent EGF-R autophosphorylation in these cells. In contrast, chronic treatment with similar doses of genistein or erbstatin resulted in a large dose-responsive decrease in EGF-R levels, and a corresponding decrease in total cellular EGF-R autophosphorylation intensity. These results demonstrate that the inhibitory effects of chronic genistein and erbstatin treatment on EGF-dependent mammary epithelial cell proliferation is not due to a direct inhibition of EGF-R tyrosine kinase activity, but results primarily from a down-regulation in EGF-R levels and subsequent decrease in mammary epithelial cell mitogenic-responsiveness to EGF stimulation.  相似文献   
140.
We present a novel transurethral technique for cystotomy repair. This method can be used for immediate bladder repair following limited bladder injury and avoids the morbidity associated with laparotomy.  相似文献   
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