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71.
72.
IL-4 plays an important role in polarizing inflammation toward a Th2 response. It remains uncertain, however, whether IL-4 also serves to prevent expression of Th1 inflammation. Therefore, using a genetically pure C57BL/6 IL-4-deficient mouse, we studied the role of IL-4 in regulating the production of IFN-gamma and Th1 inflammation in the granulomas of mice infected with Schistosoma mansoni. In contrast to normal animals, IL-4 mutant mice generated smaller liver granulomas that contained fewer eosinophils and no mast cells. Collagenase-dispersed granuloma cells were analyzed by flow cytometry and cultured in vitro to measure cytokine and Ig production. Compared with control granuloma cells, IL-4-/- cells secreted only small quantities of IL-5 and IL-10. Also, there was impaired expression of the IL-4-dependent molecules IgE and IgG1 as well as B cell surface class II and CD23. Yet the granulomas of IL-4 -/- animals produced little IFN-gamma, IgG2a, or other molecules associated with Th1 inflammation even after Ag or anti-CD3 stimulation. Splenocytes from IL-4 -/- animals stimulated with schistosome Ag also failed to produce a Th1 response. Our data show that most aspects of the Th2 response in murine schistosomiasis are highly dependent on IL-4 production. But in the absence of IL-4, neither the natural local granulomatous response to schistosome ova nor the systemic response to soluble egg Ag switches to the type 1 phenotype. Thus the production of IL-4 early in the inflammatory response is not the only factor preventing Th1 expression in inflammation.  相似文献   
73.
The distinction between benign and malignant smooth muscle tumours relying on histological features such as the mitotic index and pleomorphism remains a generally acknowledged difficulty in modern pathology. A cell image processor was therefore used to quantitatively assess the desmin and vimentin immunostain in 39 smooth muscle tumours which included 26 benign (leiomyomas) and 13 malignant (leiomyosarcomas) cases. The 13 leiomyosarcomas were primary (non-recurrent and non-metastatic). Ploidy level and cell density were also assessed on each of these 39 tumours by means of the computer-assisted microscopic analysis of 5-microns thick Feulgen-stained histological sections. The results show that while neither the ploidy level determination nor the quantitative assessment of the vimentin immunostain made it possible to distinguish between leiomyomas and leiomyosarcomas, cell density determination and the quantitative assessment of the desmin immunostain enabled such a distinction to be made. Indeed, the leiomyomas exhibited a much higher level of desmin positivity than the leiomyosarcomas, as did diploid tumours as compared to the aneuploid (benign or malignant) ones. Furthermore, the leiomyoma group exhibited a significantly lower mean cell density value than the leiomyosarcoma group. The present study further confirms the lack of relationship between ploidy level and cytological malignancy in smooth muscle tumours.  相似文献   
74.
Age adjusted mortality in Belgium (B) and The Netherlands (NL) was calculated from 5 yearly age-specific death rates between the ages 45-74 and 75-85+ years. Mortality was available in Belgium from 1954 to 1991 or 1994 (depending on the cause of death) and from 1950 to 1993 in The Netherlands. In the 45-74 years age class all-cause mortality decreased in B between 1955 and 1992 with 33% in men and 48% in women. In NL this was 11% and 40%, respectively. In the age class 75-85+ it was 21% and 37% in B, and 4% and 36% in NL, respectively. Since 1980 to the last available year there was a marked decrease in mortality in the age class 75-85+ years in men and women from B and no change in NL. Wallonia always had the highest mortality, followed by B, Flanders and NL. However, recently the observed mortality in Flanders was the lowest. Mortality trends, in both age classes and sexes, were obtained between 1980 to the last available year for 11 causes of death in men and 13 in women. Among 48 possible comparisons, 38 (79%) were in favor of B, 9 in favor of NL and 1 ex aequo. Life expectancy in 1992 was compared in the 15 EU countries. For both sexes together B ranked 8th, NL 3rd. The difference in life expectancy between the two countries was 3 year in 1967 and 1 year in 1992. Flanders ranked 5th (0.3 year lower than NL) and Wallonia 14th (2.2 years lower) when substituted for B in the EU. Portugal had the best and Denmark had the worst results between 1967 and 1992). Changes in life style-fat, salt, fruit and vegetable intake and smoking habits -which occurred since 1960 in B, its regions and in NI are consistent with the changes in mortality and life expectancy. Curative medicine and medical technology cannot explain the observed differences and trends.  相似文献   
75.
In pancreatic acinar cells low (physiological) agonist concentrations evoke cytosolic Ca2+ spikes specifically in the apical secretory pole that contains a high density of secretory (zymogen) granules (ZGs). Inositol 1,4,5-trisphosphate (IP3) is believed to release Ca2+ from the endoplasmic reticulum, but we have now tested whether the Ca(2+)-releasing messengers IP3 and cyclic ADP-ribose (cADPr) can liberate Ca2+ from AGs. In experiments on single isolated ZGs, we show using confocal microscopy that IP3 and cADPr evoke a marked decrease in the free intragranular Ca2+ concentration. Using a novel high resolution method, we have measured changes in the Ca2+ concentration in the vicinity of an isolated AG and show that IP3 and cADPr cause rapid Ca2+ release from the granule, explaining the agonist-evoked cytosolic Ca2+ rise in the secretory pole.  相似文献   
76.
A rectangular channel electrophoresis system and a cylindrical sampling capillary combination allows chemical changes in nanoliter-volume samples to be monitored as a function of time. The electrophoretic microseparation is carried out in a rectangular channel with a 7 -cm-long, 40-microm x 2.5-cm geometry and is coupled to a 50-microm-i.d. cylindrical sample introduction capillary. The channel width dimension is used as a time axis by moving the outlet of the sampling capillary across the entrance of the separation channel. Detection of the separated analyte bands is achieved with laser-induced fluorescence and spatially resolved detection based on a charge-coupled device. The system is characterized with a series of fluorescein thiocarbamyl amino acid derivatives; limits of detection are < 10(-8) M for amino acids and 10(-9)M (425 zmol) for fluorescein. The ability to achieve a time-based dynamic microseparation is demonstrated by monitoring fluorescent product formation during the enzyme-catalyzed hydrolysis of fluorescein di-beta-D-galactopyranoside (FDG), a commonly used fluorescent substrate for enzymological studies.  相似文献   
77.
78.
BACKGROUND: In 1986, we reported a group of 29 patients who were positive in serum for antimitochondrial antibody (AMA), the disease-specific marker for primary biliary cirrhosis (PBC), but who had normal liver function test results and no symptoms of liver disease. However, liver histology was diagnostic or compatible with PBC in 24 patients and normal in only two. The aims of this 10-year follow-up study were to establish whether patients with AMA have very early PBC, to assess the outlook for such patients, and to follow the progression of the disease. METHODS: All patients were assessed every year at our PBC clinic: records were reviewed, cause of death verified when applicable, and current clinical and biochemical data collected, including repeat liver histology as indicated. Serum samples from the original study were located. Original and follow-up serum samples were tested by ELISA for E2 components of pyruvate dehydrogenase complex and 2-oxoglutarate dehydrogenase complex. FINDINGS: Five patients died during follow-up; no deaths were attributable to liver disease. Median follow-up of patients who survived was 17.8 years (range 11.0-23.9) from first-detected AMA to the last follow-up review. Overall, 22 (76%) developed symptoms of PBC and 24 (83%) had liver function tests persistently showing cholestasis. Repeat liver biopsy samples were obtained from ten patients; among these patients PBC progressed from Scheuer grade 1 to grade 2 in two and from grade 1 to grade 3 in two. No patient developed clinically apparent cirrhosis. ELISA of baseline serum samples from 27 patients was positive in 21, all of whom had original liver histology compatible with or diagnostic of PBC. Of the six patients who tested negative, only one had an original liver biopsy sample that was compatible with PBC. INTERPRETATION: This study confirms that before the advent of any clinical or biomedical indications, individuals positive for AMA do have PBC. This finding extends the natural history of PBC back in some cases for many years. What determines the eventual progression to biochemically and clinically apparent disease is not yet understood. During our study no patient developed clinically apparent portal hypertension or cirrhosis. Thus, although the finding of a solitary persistently raised AMA is confirmation of a diagnosis of PBC, patients with AMA but no other signs or symptoms of PBC seem to have slow progression of the disease.  相似文献   
79.
Lipopeptide L-733,560 is a water-soluble derivative of pneumocandin B0 that exhibits enhanced anti-Candida activity. We investigated the in vitro activity of L-733,560 compared with those of amphotericin B, flucytosine, and itraconazole, against fluconazole-resistant (n = 44) and fluconazole-susceptible (n = 46) Candida albicans isolates. Tests were performed with a photometer-read broth microdilution method with RPMI-2% glucose and National Committee for Clinical Laboratory Standards reference strains. Except for those of itraconazole, MICs were not significantly different between the two groups of isolates, as expected for agents with different mechanisms of action. L-733,560 was the most active agent against C.albicans, with MICs for 50 and 90% of the strains tested of 0.01 and 0.06 microgram/ml, respectively.  相似文献   
80.
During oogenesis in Drosophila, germ cells appear in sequential clusters of 16 interconnected cells. The events surrounding the differentiation of these cells are not fully understood. Here we present genetic and morphological analysis of mutations in the gene stand still (stil). Through complementation analyses we have refined the location of this gene to cyological region 49B-C. Our analyses of ovaries from ethylmethane sulfonate (EMS)-induced mutant alleles of this gene suggest that mutations in the stil gene produce a wide range of phenotypic abnormalities, from the absence of germ cells in the most severe alleles, to egg chambers with cytoskeletal defects in the less severe alleles. Our results suggest a role for this gene in specifying or maintaining a cytoskeletal component, with consequences during oogenesis and possibly during germ line sex determination.  相似文献   
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