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排序方式: 共有341条查询结果,搜索用时 15 毫秒
1.
S L Sipes D H Chestnut R D Vincent C P Weiner C S Thompson P Chatterjee 《Anesthesiology》1991,75(6):1010-1018
Magnesium sulfate (MgSO4) attenuates the maternal compensatory response to hemorrhage in gravid ewes, perhaps by decreasing the response to endogenous vasopressors. The purpose of this study was to determine whether MgSO4 alters the cardiovascular response of gravid ewes to vasopressor agents. Sixteen gravid ewes underwent a series of experiments consisting of administration of two exogenous and two endogenous vasopressors, each with and without a concurrent MgSO4 infusion. Dose-response curves were constructed for phenylephrine (an alpha 1-adrenergic agonist), ST-91 (an alpha 2-adrenergic agonist), angiotensin II, and arginine vasopressin (AVP). MgSO4 significantly attenuated the increase in maternal mean arterial pressure and systemic vascular resistance and the decrease in cardiac output during ST-91 infusion but not during phenylephrine, angiotensin II, or AVP infusions. MgSO4 significantly attenuated the increase in uterine vascular resistance during phenylephrine, ST-91, and angiotensin II infusions and the decrease in uterine blood flow during phenylephrine and angiotensin II infusions. MgSO4 also appeared to attenuate the decrease in uterine blood flow during ST-91 infusion (P = 0.067). The present study suggests that MgSO4 antagonizes the effects of alpha 1-adrenergic agonists, alpha 2-adrenergic agonists, and angiotensin II on the uterine vasculature, thus providing a level of protection for the fetus in situations of maternal stress. 相似文献
2.
J A Barnard C C Bascom R M Lyons N J Sipes H L Moses 《The American journal of the medical sciences》1988,296(3):159-163
Transforming growth factor beta is a polypeptide growth factor with a multiplicity of diverse biologic effects. Increasingly, data support a role for TGF beta in the autocrine regulation of normal epithelial cell growth (Figure 1). Definition of the normal pathways for growth stimulation and inhibition of epithelial cell growth by autocrine peptides like TGF beta and TGF alpha undoubtedly will increase understanding of normal growth and development, embryogenesis, wound repair, and tumorigenesis. 相似文献
3.
4.
Chloroform toxicity in mice: correlation of renal and hepatic necrosis with covalent binding of metabolites to tissue macromolecules 总被引:4,自引:0,他引:4
Chloroform (CHCl3) treatment caused centrolobular hepatic necrosis in mice of both sexes whereas renal necrosis was observed only in male mice. Following administration of 14CHCl3 to mice, substantial amounts (about 3 mmole/g) of radiolabeled material were covalently bound to proteins in the liver and kidney. The amount of convalent binding paralleled the extent of renal and hepatic necrosis both in normal animals and in male mice pretreated with either phenobarbital or piperonyl butoxide, agents which induce or block, respectively, microsomal drug metabolizing enzymes. These results suggest that the covalent binding is due to a metabolite of CHCl3. Evidence that the covalent binding is causally related to the tissue necrosis was obtained from autoradiograms showing that the radioactivity is located mainly in the necrotic lesions. 相似文献
5.
Uterine myomata and outcome of assisted reproduction 总被引:5,自引:8,他引:5
Ramzy AM; Sattar M; Amin Y; Mansour RT; Serour GI; Aboulghar MA 《Human reproduction (Oxford, England)》1998,13(1):198-202
The aim of this work was to study the effect of uterine myomata on the
implantation rate and outcome in in-vitro fertilization (IVF) and
intracytoplasmic sperm injection (ICSI). Among 406 patients, 51 (12.6%)
were found to have uterine corporeal myomata. Twelve patients were excluded
from the study as they had large myomata, submucous myomata or intramural
myomata encroaching on the cavity. These patients were advised to have
myomectomy before being enrolled in the IVF/ICSI programme. The remaining
patients (n = 39) were sorted according to the number, site and size of the
myomata as assessed by transvaginal sonography. Three patients had more
than one myoma. Most of the myomata were subserous (72.7%) and the mean
diameter of the myomata was 3.5 +/- 0.9 cm. A control group (n = 367) was
chosen with normal uteri and no history of uterine reconstruction surgery.
The mean age of myoma patients was 34.7 +/- 3.6 years as compared to 34.0
+/- 4.4 years in the control group. The age, period of infertility, body
mass index, duration and number of human menopausal gonadotrophin ampoules
needed for stimulation, oestradiol levels, number of oocytes retrieved and
the fertilization rate were not significantly different in the myoma
patients compared to the control group. Fifteen myoma patients (38.5%)
subsequently showed one or more pregnancy sacs on ultrasonography of which
three (20%) spontaneously aborted during the first trimester and two
(13.3%) had preterm labour, as compared to 123 (33.5%), 19 (15.5%) and nine
(7.3%) respectively, among the control group (P = 0.27, 0.33 and 0.21). In
conclusion, uterine corporeal myomata, not encroaching on the cavity and
<7 cm in mean diameter, do not affect the implantation or miscarriage
rates in IVF or ICSI.
相似文献
6.
7.
Since chlorine placement and the degree of chlorination of the biphenyl nucleus play an important role in the metabolism and ultimate elimination of polychlorinated biphenyls (PCBs), we have studied the metabolism of 4,4'-dichlorobiphenyl (4-DCB) by human hepatic microsomes. This low molecular weight PCB congener is substituted at the preferred site of metabolism (para-position). 4-DCB was metabolized by human microsomes with a Km of 0.43 microM and a Vmax of 1.2 pmoles/mg microsomal protein/min. Six metabolites were identified: 4,4'-dichloro-3,3'-biphenyldiol, 4'-chloro-3-biphenylol, 4'-chloro-4-biphenylol, 4,4'-dichloro-2-biphenylol, 4,4'-dichloro-3-biphenylol (most abundant), and 3,4'-dichloro-4-biphenylol. [14C]-4-DCB equivalents were found to covalently bind to microsomal protein. Addition of a 1 mM concentration of reduced glutathione decreased the degree of covalent binding. These data suggest that human microsomes metabolize this PCB through an arene oxide and that an "NIH shift" occurs. When UDPGA was added to the incubation, human microsomal glucuronosyltransferase catalyzed the formation of the glucuronide of the major metabolite, 4,4'-dichloro-3-biphenylol. These and previous in vitro results show that the biotransformation of PCBs by humans is governed by the same principles established for the in vivo biotransformation of PCBs by the rat, mouse and monkey. That is, PCBs without two adjacent unsubstituted carbon atoms are poorly metabolized and that an unsubstituted para-position facilitates metabolism. 相似文献
8.
The "ocular zingerone test" was employed to detect early alterations in peripheral nerve function which were associated with acrylamide intoxication in the rat. Acrylamide treatment resulted in a dose-related prolongation of the behavioral response to ocular zingerone. Significant alterations in the zingerone response occurred prior to detectable alterations in peripheral sensory and motor nerve function. Acrylamide-induced prolongation of the zingerone response appears to be the result of functional alterations in cholinergic neurotransmission in the autonomic nervous system. It is concluded that the "ocular zingerone test" is a simple, sensitive technique with which the degree of acrylamide intoxication may be quantified in the rat. 相似文献
9.
四氯偶氮苯(3,3’,4,4’tetrachloroazobenzene,TCAB)和四氯氧化偶氮苯(3,3’,4,4’tetrachloroazoxybenzene,TCAOB)是在合成氯代或二氯代苯胺类除草剂时生成的污染废弃物。此类除草剂经... 相似文献
10.
G Saggese S Bertelloni GI Baroncelli G Federico 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(6-7):532-535
Osteoporosis is a common finding in Turner's syndrome. To test the hypothesis that calcitonin deficiency may contribute to bone mineral loss in Turner's syndrome, we studied basal and calcium-stimulated (2 mg/kg body weight in 5 min) levels of total calcitonin, extractable calcitonin and katacalcin in 15 girls with Turner's syndrome and osteoporosis. Fifteen age-matched healthy girls were studied as controls. Both basal calcitonin (total and extractable) and katacalcin values were not significantly different in patients with Turner's syndrome in comparison with those of the controls. The calcium stimulation test showed a similar "C" cell secretory reserve in both groups. The calculation of delta CT/delta iCa of total and extractable calcitonin and delta KC/delta iCa, which accounts for individual variations in serum ionized calcium increases, did not show any significant difference between girls with Turner's syndrome and controls. We conclude that calcitonin deficiency is not a causative factor of osteoporosis in girls with Turner's syndrome and that in this syndrome long-life estrogen deficiency does not impair "C" cell secretory activity. 相似文献