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排序方式: 共有846条查询结果,搜索用时 15 毫秒
1.
2.
Balloon dacryocystoplasty: indications and contraindications 总被引:3,自引:0,他引:3
3.
In the symptomatic treatment of mild to moderately severe dementia associated with Alzheimer's disease, donepezil (E2020) has been introduced for the inhibition of acetylcholinesterase activity in the human brain. However, there is no morphological evidence as to how this chemical agent affects the acetylcholinesterase-positive structures in the various areas of the human and the rat CNS. This study demonstrates by histochemical means that donepezil exerts a dose-dependent inhibitory effect in vitro on acetylcholinesterase activity. The most sensitive areas were the cortex and the hippocampal formation. Within the different layers of the cortex, the cholinoceptive acetylcholinesterase-positive postsynaptic pyramidal cell bodies were more sensitive than the presynaptic cholinergic axonal processes. In the cortex, the cell body staining was already abolished by even 2 x 10(-8)M donepezil, whereas the axonal staining could be eliminated only by at least 5 x 10(-8)M donepezil. In the hippocampus, the axonal acetylcholinesterase reaction end-product was eliminated by 5 x 10(-7)M donepezil. The most resistant region was the putamen, where the staining intensity was moderately reduced by 1 x 10(-6)M donepezil. In the rat brain, the postsynaptic cholinoceptive and presynaptic cholinergic structures were inhibited by nearly the same dose of donepezil as in the human brain. These histochemical results provide the first morphological evidence that, under in vitro circumstances, donepezil is not a general acetylcholinesterase inhibitor in the CNS, but rather selectively affects the different brain areas and, within these, the cholinoceptive and cholinergic structures. The acetylcholinesterase staining in the nerve fibers (innervating the intracerebral blood vessels of the human brain and the extracerebral blood vessels of the rat brain) and at the neuromuscular junction in the diaphragm and gastrocnemius muscle of rat, was also inhibited dose dependently by donepezil.It is concluded that donepezil may be a valuable tool with which to influence both the pre- and the postsynaptic acetylcholinesterase-positive structures in the human and rat central and peripheral nervous systems. 相似文献
4.
Duncan WC; Illingworth PJ; Young FM; Fraser HM 《Human reproduction (Oxford, England)》1998,13(9):2532-2540
The molecular mechanisms involved in luteolysis are still unclear in the
primate. This study aimed to investigate the effect of induced luteolysis
on the ovarian luteinizing hormone (LH) receptor and the steroidogenic
enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset
monkey. Luteolysis was induced in the mid-luteal phase either directly by
systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal
using systemic gonadotrophin releasing hormone antagonist (GnRHant)
treatment. The LH receptor was studied by isotopic mRNA in-situ
hybridization and in-situ ligand binding and 3beta-HSD expression was
studied using isotopic mRNA in-situ hybridization and immunohistochemistry.
Induced luteolysis was associated with a reduction in the expression of LH
receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a
reduction in the LH receptor (P < 0.05) and 3beta-HSD protein
concentrations within 24 h. There were no differences in the findings
whether luteolysis was induced with PGF2alpha or GnRHant. This study shows
that disparate mechanisms to induce luteolysis in the primate result in an
identical rapid loss of the LH receptor and 3beta-HSD. In conclusion,
induced luteolysis leads to rapid loss of the steroidogenic pathway in
luteal cells.
相似文献
5.
HM Clink 《Journal of clinical pathology》1980,33(8):799-800
6.
We studied the replacement of hepatic S9 with in vivo and in vitro induced hepatocytes as a metabolic activation system with the aim of broadening the possibilities of mutagenic assays. Rats were pretreated with beta-naphthoflavone (BNF), phenobarbital (PB), 3-methylcholanthrene (MC) and a combination of BNF and PB (BNF + PB). Mutagenic activation of benzo[a]pyrene (BP) and 2-aminoanthracene (2AA) by hepatic S9 and hepatocytes was determined in the Ames test. Primary rat hepatocytes were used for in vitro induction and were used as the activating system in the Ames test. In vivo BNF treatment greatly increased the metabolic activation capacity of hepatic S9 and hepatocytes towards BP. With regard to 2AA activation, S9 and hepatocytes showed different BNF induction profiles. PB treatment reduced the mutagenicity of both compounds. Although ethoxyresorufin O-dealkylase (EROD) activity of S9 from BNF + PB-treated animals was almost 30-fold greater than the control, its effectiveness in activation of 2AA was below the control level. A large part of the EROD activity of control cells was lost during culture, together with the ability to activate 2AA, however, 72 h of MC induction increased EROD activity to 200-fold of the control, which corresponds to 28% of that of in vivo induced hepatocytes. The mutagenic potential of BP activated by in vitro induced hepatocytes was 10-fold above the control, which is 47% of the mutagenicity detected following in vivo induction. In vitro induced hepatocytes increased 2AA mutagenicity to 14.6-fold over the control, which corresponds to 68% of in vivo induction. Our results suggest that primary culture of hepatocytes provides a useful model for the study of the role of metabolic activation processes concerning enzyme activity of cytochromes P450 and other metabolic enzymes and induction profiles of different inducers. 相似文献
7.
8.
Semen parameters and testicular pathology in men with testicular cancer and contralateral carcinoma in situ or bilateral testicular malignancies 总被引:2,自引:2,他引:2
Kliesch S; Bergmann M; Hertle L; Nieschlag E; Behre HM 《Human reproduction (Oxford, England)》1997,12(12):2830-2835
We evaluated 14 patients with bilateral testicular tumour, one-sided tumour
and contralateral carcinoma in situ (CIS) of the testis or testis tumour in
single testis with respect to their fertility. We analysed semen
parameters, serum hormones [follicle-stimulating hormone (FSH), luteinizing
hormone (LH) and testosterone], testicular sonography, testicular volumes
and testicular histology prior to further anti-cancer treatment. Ten out of
14 patients showed normal or reduced sperm concentrations, while 4/14
patients were azoospermic. Serum FSH levels showed a significant negative
correlation with sperm concentrations in patients with testicular
malignancies (r = -0.64, P = 0.025). Testicular volumes revealed a
significant positive correlation with semen parameters in patients with
testes that were affected by CIS (r = 0.733, P = 0.038). We conclude that
even bilateral testicular cancer and/or CIS do not preclude fertility and,
therefore, patients should be offered andrological investigation and
therapy, including possibly surveillance strategy or the chance for
cryopreservation of the semen prior to further treatment in order to
preserve their chances for paternity.
相似文献
9.
10.
Survey of CAG/CTG repeats in human cDNAs representing new genes: candidates for inherited neurological disorders 总被引:3,自引:2,他引:3
Neri C; Albanese V; Lebre AS; Holbert S; Saada C; Bougueleret L; Meier-Ewert S; Le Gall I; Millasseau P; Bui H; Giudicelli C; Massart C; Guillou S; Gervy P; Poullier E; Rigault P; Weissenbach J; Lennon G; Chumakov I; Dausset J; Lehrach H; Cohen D; Cann HM 《Human molecular genetics》1996,5(7):1001-1009