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41.
We examined if rat myometrial cells in culture generate nitric oxide (NO)
and express various isoforms of NO synthase (NOS). Myometrial cells
isolated from rats on day 18 of gestation were incubated with various
stimulators and inhibitors of NOS for 24 and 48 h, and NO production was
evaluated by measuring nitrites in the media and NOS proteins in the cell
lysates. NO was produced by myometrial cells and its production inhibited
by N(G)-methyl-L-arginine (L-NMMA). This inhibition was reversed by
L-arginine (3 mM). Interleukin-1beta (IL- 1beta) significantly stimulated
NO production, in a dose-dependent manner. The IL-1beta-stimulated NO
production was inhibited by the NOS inhibitor, L-NMMA, whose effects were
reversed by L-arginine. Abundant NOS III protein was detectable in freshly
isolated myometrial cells, and this was maintained in culture in the
presence of fetal bovine serum (FBS; 10%). In the absence of FBS, NOS III
levels decreased significantly (by 90%) within 24 h. In contrast, NOS I and
NOS II proteins were undetectable in freshly isolated muscle cells and in
cells cultured without IL-1beta. However, NOS II protein in these cells was
induced by IL-1beta. Thus, NO is produced by myometrial cells through the
NOS III isoform, and the myometrial NO may be important in maintaining
uterine quiescence during pregnancy.
相似文献
42.
Krezowski J Knudson D Ebeling C Pitstick R Giri RK Schenk D Westaway D Younkin L Younkin SG Ashe KH Carlson GA 《Human molecular genetics》2004,13(18):1989-1997
Phenotypes produced by expression of human amyloid precursor protein (APP) transgenes vary depending on the genetic background of the mouse. FVB/N mice overexpressing human APP695 develop a central nervous system disorder and die prematurely, precluding development of Abeta peptide amyloid plaques. 129S6 mice are resistant to the lethal effects of APP overexpression, allowing sufficient levels of Abeta expression for the development of amyloid plaques and age-dependent memory deficits. To identify the genes that determine susceptibility or resistance to APP we analyzed crosses involving FVB/NCr and 129S6.Tg2576 mice that overexpress 'Swedish' mutant (K670N, M671L) APP695. APP transgene-positive FVB129S6F1 (F1) mice are resistant to the lethal effects of APP overexpression, so FVBxF1 backcross and F2 intercross offspring were produced. Analysis of age of death as a quantitative trait revealed significant linkage to loci on proximal chromosome 14 and on chromosome 9; 129S6 alleles protect against the lethal effects of APP. Within the chromosome 14 interval are segments homologous to regions on human chromosome 10 that have been linked to late onset Alzheimer's disease or to levels of Abeta peptide in plasma. However, analysis of plasma Abeta peptide concentrations at 6 weeks in backcross offspring produced no significant linkage. Similarly, elevation of human Abeta peptide concentrations by expression of mutant presenilin transgenes did not increase the proportion of mice dying prematurely, suggesting that early death reflects effects of APP or fragments other than Abeta. 相似文献
43.
Assessment of an abbreviated odorant identification task for children: a rapid screening device for schools and clinics 总被引:1,自引:0,他引:1
To validate the level of olfactory performance of children, we tested 825 volunteers, aged 4–17 years, with an abbreviated form of our pediatric odorant identification task. The test consisted of sniffing and identifying five odorants (baby powder, bubble gum, candy cane, licorice and peach). Mean olfactory scores increased as a function of age, reaching a plateau of about 94–95% correct at 8 years of age. In general, girls out–performed boys. Physicians require a test instrument such as the one we have devised to allow them to diagnose olfactory dysfunction in children. The present task is particularly applicable in screening large numbers of children in clinics or schools because it can be administered easily and rapidly. Adult subjects with olfactory dysfunction also performed poorly on this odorant identification task designed for children. Therefore, we expect that our odorant identification task will also detect children with severe olfactory dysfunction. 相似文献
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46.
Ziel des Artikels ist es nicht, internistisch-onkologisches Lehrbuchwissen zu ersetzen, sondern für die klinische Routine
eine Basisinformation zur Prophylaxe und Therapie unerwünschter Wirkungen einer zytostatischen Chemotherapie bei Kopf-Hals-Karzinomen
zu geben. Hierzu werden im 1. Abschnitt generelle Empfehlungen zur Vermeidung unerwünschter Wirkungen im Umgang mit Zytostatika
dargestellt. Im 2. Abschnitt soll auf die Besonderheiten der heute bei Kopf-Hals-Karzinomen zugelassenen Substanzen eingegangen
werden mit entsprechenden substanzspezifischen Empfehlungen zur Prophylaxe und Therapie unerwünschter Wirkungen. Im 3. Abschnitt
werden spezielle supportive Therapieverfahren zur Behandlung bzw- Vermeidung unerwünschter Wirkungen einer zytostatischen
Chemotherapie abgehandelt, die unabh?ngig von der jeweiligen Substanz eingesetzt werden k?nnen. 相似文献
47.
C P Rodda M Kubota J A Heath P R Ebeling J M Moseley A D Care I W Caple T J Martin 《The Journal of endocrinology》1988,117(2):261-271
Parathyroid hormone (PTH)-like bioactivity, assayed as adenylate cyclase response in UMR 106-01 osteogenic sarcoma cells, was present in extracts of sheep fetal and maternal parathyroid glands and placenta. Preincubation of extracts with PTH(1-34) antiserum inhibited approximately 40% of the bioactivity in fetal parathyroid extracts, 50% in maternal parathyroid extracts, but only 10% of the bioactivity in the placental extract. Partial purification of placental extracts by chromatography yielded fractions containing PTH-like bioactivity which were similar in behaviour to that of PTH-related protein (PTHrP) from a human lung cancer cell line (BEN). An antiserum against synthetic PTHrP(1-16) partially inhibited the bioactivity of the placental extract and synthetic PTHrP(1-34), but had no effect on the bioactivity of bovine PTH(1-34) or bovine PTH(1-84). The placental PTH-like bioactivity was higher in mid- than in late gestation. Fetal parathyroid glands contained the highest PTH-like bioactivity. Thyroparathyroidectomy of one fetal twin lamb in each of 16 ewes between 110 and 125 days of gestation resulted in decreases of the plasma calcium concentration and reversal of the placental calcium gradient that existed between the ewe and the intact fetus. Perfusion of the placenta of each twin in anaesthetized ewes was carried out sequentially with autologous fetal blood in the absence of the exsanguinated fetus. The plasma calcium concentration in the blood perfusing the placenta of each twin increased, but reached a plateau at a lower concentration in the perfusing blood of thyroparathyroidectomized fetuses than in that of the intact fetuses. Addition of extracts of fetal parathyroid glands or of partially purified PTHrP resulted in further increases in plasma calcium in the autologous blood perfusing the placentae of thyroparathyroidectomized fetuses, but addition of bovine PTH(1-84) or rat PTH(1-34) had no effect. The presence of this PTH-like protein in the fetal parathyroid gland and placenta may contribute to the relative hypercalcaemia of the fetal lamb. This protein, which is similar to PTHrP associated with humoral hypercalcaemia of malignancy, stimulates the placental calcium pump responsible for maintaining a relative fetal hypercalcaemia during gestation. 相似文献
48.
Colorectal hemangioma: radiologic findings 总被引:1,自引:0,他引:1
The authors correlated radiographs with the clinical and histologic data of 12 patients with colorectal hemangioma. All patients presented with rectal bleeding, which was chronic in seven. Phleboliths were also visible in seven cases, which correlated with chronic bleeding in five. On barium studies, three masses were soft and three produced rigid narrowing. The atypical features of rigid luminal narrowing, which might mimic a carcinoma, and hypovascularity correlated with chronic bleeding or visible phleboliths, which suggest the correct diagnosis of colorectal hemangioma. 相似文献
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