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91.
The total hemolytic complement activity of CH50 and its fractions C3 and C4 was determined in the sera of 196 patients with carcinoma of the oral cavity, 172 patients with carcinoma of the uterine cervix, and 166 patients with breast cancer. The values were compared with those of 18 patients with mammary dysplasia, 32 patients with mild to moderate dysplasia of the cervix, and 100 healthy, normal age- and sex-matched controls. No alterations in CH50, C3, and C4 were observed in the sera of patients with benign lesions, whereas a significant rise in the three factors was observed in all the cancer patients studied. The complement activity increased significantly with the progression of the disease up to stage III and remained persistently elevated thereafter. Patients who had a clinical cure had normal levels of CH50, C3, and C4, whereas the values remained elevated in patients who were still undergoing treatment for residual lesions.  相似文献   
92.
We report on 2 unrelated patients with Costello syndrome. The first is a 5-year-old girl with “coarse” face, nasal papillomata, redundant skin of feet and hands, hyperextensible hand and finger joints, curly hair, feeding problems due to oral motor apraxia, growth and psychomotor retardation. The second is a 3-year-old boy with “coarse” face, loose skin on hands and feet, curly hair, oral motor apraxia, severe growth and psychomotor retardation. In both patients urine sialic acid levels were found to be repeatedly high. The meaning of this biochemical abnormality is discussed. © 1993 Wiley-Liss, Inc.  相似文献   
93.
Assessment of the role of "enkephalinase" in cholecystokinin inactivation   总被引:2,自引:0,他引:2  
Cholecystokinin octapeptide and the C-terminal tetrapeptide are hydrolysed by a highly purified preparation of "enkephalinase" (EC 3.4.24.11). In both cases the Asp-PheNH2 bond is hydrolysed and the Gly4-Trp5 bond of the octapeptide is also cleaved, though more slowly. Evaluated from the appearance of Phe-NH2, the Km for the hydrolysis of the octapeptide by the purified peptidase is 57 microM and that for the tetrapeptide 65 microM. The apparent affinities of these peptides for the enzyme in striatal membranes are similar. The importance of this hydrolysis in the inactivation of endogenous cholecystokinin was assessed by studying the fate of cholecystokinin immunoreactivity released from slices of rat cerebral cortex and striatum by depolarization with potassium. In the absence of any peptidase inhibitor only 16% of the peptide released from the tissue was recovered in immunoreactive form in the medium, indicating that endogenous cholecystokinin octapeptide is, like other neuropeptides, rapidly and extensively hydrolysed following release. Selective inhibition of "enkephalinase" by Thiorphan (DL-3-mercapto-2-benzylpropanoyl glycine) did not significantly alter the recovery from slices of cerebral cortex and had only a very slight effect in the case of striatal slices. This suggests that, while cholecystokinin octapeptide is a substrate for "enkephalinase", this enzyme plays a less important (if any) role in the inactivation of endogenous cholecystokinin than for the opioid peptides.  相似文献   
94.
95.
An ultrastructural analysis of oral balloon cell nevus of intramucosal type complemented with an immunohistochemical study was performed for the first time. The lesion was composed of large balloon cells with an admixture of small nevus cells and melanophages at the periphery. Balloon cells showed cytoplasmic accumulation of vacuoles of varying sizes and the presence of microgranular and vacuolated melanosomes were found. Residual cytoplasm contained no identifiable organelles. A spectrum of transitional forms between balloon cells and conventional nevus cells with microvacuoles was readily observed. Both cells exhibited intense immunoreactivity to multiple melanocytic markers. Ballooning phenomenon was not evident in melanophages containing a large amount of melanosome complex. It can be inferred, from the present and previous observations, that progressive vacuolization of melanosomes in nevomelanocytes may be responsible for the formation of peculiar ballooning appearance, suggesting an aberrant melanogenesis.  相似文献   
96.
In freely moving rats, effects of unilateral haloperidol injection into the substantia nigra were monitored with in vivo voltammetry in the bilateral striata. The electrochemical responses at 120 mV versus Ag-AgCl, reflecting mainly a level of 3,4-dihydroxyphenylacetic acid (DOPAC), increased both in the striata within 1.5 h after 5 μg of haloperidol treatment. In the experiments of high-performance liquid chromatography with electrochemical detection, the ratio of DOPAC to dopamine in the striata significantly increased at 2.75 h after drug treatment. These data support the idea that unilateral injection of haloperidol into the substantia nigra in freely moving rats increases dopamine turnover in the bilateral striata.  相似文献   
97.
Mechanisms regulating the content of the putative peptide transmitters, substance P and somatostatin, were examined in several neuronal populations in culture. Substance P levels increased more than 25-fold within 48 h in sympathetic neurons in the explanted rat superior cervical ganglion, and remained elevated for 4 weeks. Identity of the peptide was authenticated by combined high pressure liquid chromatography-radioimmunoassay. Veratridine prevented the increase of substance P in vitro, and tetrodotoxin blocked the veratridine effect, suggesting that sodium ion influx and membrane depolarization prevent peptide elevation. Veratridine (or potassium)-induced membrane depolarization released substance P into the culture medium through a calcium-dependent process. Consequently, at least some veratridine effects are attributable to release and subsequent depletion of ganglion peptide. However, the inhibitory effects of veratridine were far greater than could be accounted for by the quantity of peptide released, suggesting a separate influence on net synthesis (synthesis less catabolism) of substance P. Viewed in conjunction with previous in vivo studies, our observations suggest that trans-synaptic impulses, through the mediation of postsynaptic sodium flux, release substance P from sympathetic neurons and also regulate intracellular peptide metabolism. To determine whether the processes regulating substance P in sympathetic neurons reflect generalized mechanisms, a different peptide, somatostatin, was examined in sympathetic neurons; moreover, substance P was examined in a different neuronal population, special sensory neurons in the nodose ganglion. Substance P levels increased significantly in both sympathetic and sensory neurons after explantation, and somatostatin levels increased in sympathetic neurons. In each instance, the increase was dependent upon the presence of the calcium ions. Moreover, these increases were all prevented by veratridine, in a tetrodotoxin-sensitive manner. Our observations suggest that common regulatory mechanisms govern peptide transmitter metabolism in diverse neuronal populations.  相似文献   
98.
Pharmacokinetics of a novel oral slow-release form of misoprostol   总被引:1,自引:0,他引:1  
BACKGROUND: The pharmacokinetics of a novel slow-release (SR) misoprostol was studied and compared to conventional misoprostol. METHODS: Thirty-one women, pregnant between 8 and 12 weeks, requesting surgical abortion were randomly allocated to receive orally 400 microg conventional misoprostol, 400 microg SR misoprostol or 800 microg SR misoprostol. Venous blood samples were taken at 0, 30, 60, 120, 240 and 360 min after the administration of misoprostol. Misoprostol acid (MPA) was determined in serum samples using liquid chromatography/tandem mass spectrometry. RESULTS: Serum peak concentration (Cmax) was highest for conventional oral misoprostol. The time to peak concentration (Tmax) was similar for all groups. The area under the curve up to 360 min was similar for conventional and for 800 microg SR misoprostol and significantly greater for these groups compared to 400 microg SR misoprostol (P = 0.013). CONCLUSION: The new SR form of misoprostol demonstrated lower peak levels but longer-lasting elevation in plasma levels compared to conventional oral misoprostol. The AUC for 800 microg SR misoprostol was similar to that of 400 microg of conventional oral misoprostol. SR misoprostol may offer an alternative to repeated administration of oral misoprostol or to vaginal administration.  相似文献   
99.
Orally induced tolerance is a physiologically relevant form of peripheral tolerance, which is believed to be important for the prevention of pathological immune responses in the gut. Of several mechanisms proposed to mediate oral tolerance, one that has received much attention recently is the concept of regulatory CD4+ T cells. As recent studies have suggested that interleukin (IL)-15 may be important for the differentiation and maintenance of regulatory CD4+ T cells, we have examined the role of IL-15 in oral tolerance, using a soluble form of the IL-15 receptor (sIL-15R) which blocks the biological effects of IL-15 in vivo. Oral tolerance induced by feeding mice ovalbumin (OVA) in a low-dose regimen believed to induce regulatory T cell activity was not affected by the administration of sIL-15R during either the induction or maintenance phase of tolerance. Thus, oral tolerance does not involve an IL-15-dependent mechanism.  相似文献   
100.
In vivo experiments on rats and rabbits showed that megestrol caproate, a 17-alpha-hydroxyprogesterone derivative exhibits 10-fold higher gestagenic activity compared to progesterone and possesses no androgenic, anabolic, and estrogenic activities.  相似文献   
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