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排序方式: 共有1816条查询结果,搜索用时 15 毫秒
991.
JR Nation PJ Wellman CL Livermore DK Miller GR Bratton 《Canadian Metallurgical Quarterly》1997,92(1):47-57
We have cloned a full length cDNA coding for the activin type IIB receptor (GactRIIB) from the goldfish ovary. GactRIIB shares 73 and 70% amino acid identity in the extracellular domain, and 78 and 80% identity in the intracellular domain with the type IIB receptors of the mouse and Xenopus respectively. The intracellular domain of GactRIIB contains two serine kinase consensus sequences, DFKSRN and GTRRYMAPE, in agreement with the reports in other vertebrates that serine/threonine phosphorylation is involved in activin signal transduction. The identity of GactRIIB was confirmed by transient expression in the COS cells followed by activin binding. Iodinated human activin A bound to the GactRIIB-transfected cells and the binding could be completely inhibited by unlabeled activin. Affinity labeling revealed a band of about 85 kDa, which is in agreement with the reported type II receptors in other vertebrates. Together with the fact that activin is expressed in the goldfish ovary, the cloning of activin receptors from the ovary suggests paracrine and autocrine roles for activin in the goldfish ovarian functions. 相似文献
992.
A prospective incidence study was used to estimate the effect on transmission of hepatitis B virus (HBV) in England and Wales of maximising uptake of HBV vaccination in patients at risk attending genitourinary medicine (GUM) clinics or any medical services. Laboratory based surveillance in 1993 gave an incidence of acute symptomatic hepatitis B of 1 case per 100,000 population. Transmission through sexual intercourse was twice as common as through injecting drug use. Less than 20% of patients with acute HBV infection had attended a GUM clinic before their illness, but 42% had had access to other medical services where vaccination could have been offered routinely. Sixty per cent of patients' sexual partners and 37% of other members of their household had been offered vaccination. Compared with universal infant or pre-adolescent vaccination, extending the current selective policy to all who attend GUM clinics or any medical services would have a limited impact on the incidence of HBV, particularly as uptake of three doses of vaccine in adults is likely to be low. 相似文献
993.
The author reveal the results of treatment with ciclopiroxolamine of women suffering from mycotic colpitis and using OC's. The research covers 26 women users of monophasic OC's with mycotic colpitis during the last 2-3 weeks before the research. The cause for the colpitis in 92% of cases is Candida albicans. The treatment was successful in 84.6% of the cases after the first 6-day-course with Batrafen creme. With 7.7% the treatment course with Batrafen creme was repeated, and with another 7.7% was included oral antimycotic (itraconazol). After treatment was performed microbiological check-up that confirmed the positive result of treatment. The authors' conclusion is that Batrafen creme is an effective device suitable for application on patients, CO's users. 相似文献
994.
M Tuchman GR Lichtenstein BS Rajagopal MT McCann EE Furth J Bavaria PB Kaplan JB Gibson GT Berry 《Canadian Metallurgical Quarterly》1997,127(6):446-449
OBJECTIVES: We aimed to determine whether stethoscopes and otoscopes used in community paediatric clinics harboured pathogenic micro-organisms, and, if so, which measures could prevent this. METHODS: Fifty-five stethoscopes belonging to paediatric physicians working in 12 community clinics were sampled for bacterial cultures by two methods: (i) direct impression of the diaphragm and bell section of each stethoscope for 5 seconds onto blood agar plates and a mannitol-salt-agar plate; (ii) swabbing the entire surface of the diaphragm of the stethoscope with a sterile cotton-tipped applicator. Forty-two otoscopes from the same physicians were sampled by rubbing the handles of the otoscopes with cotton-tipped swabs. The plates were incubated at 37 degrees C for 48 hours and examined for colony growth at 24 and 48 hours of incubation. Culture results were recorded as mean numbers of colony-forming units (CFUs). Eight additional stethoscope diaphragms were chosen at random at the participating clinics and cultured as described above. They were then wiped with alcohol swabs (isopropyl alcohol 70%), allowed to air dry for approximately 10 minutes and cultured a second time. RESULTS: All the stethoscopes and 90% of the otoscope handles were colonized by microorganisms. Staphylococci were isolated from 85.4% of the stethoscopes and 83.3% of the otoscopes, with 54.5% and 45.2% respectively being S. Aureus. Methicillin-resistant S. aureus were found in four each of the stethoscopes (7.3%) and otoscopes (9.5%). Cleaning with alcohol reduced the colony count by an average of 96.3%. CONCLUSIONS: Fomites can harbour potentially pathogenic bacteria, and with the increasing trend for children with more complex medical problems to be managed in an ambulatory setting, often by physicians who also work in hospitals, there is a real risk of spreading potentially serious infections to such patients. Simple cleansing with alcohol effectively eliminates the bacterial contamination of the fomites, and should be encouraged. 相似文献
995.
Endometriosis is classically defined as the growth of endometrial cells at sites outside the uterus. It is a common disease characterized by infertility, chronic pain and adhesion formation. Immune dysregulation, evidenced by decreased clearance of endometrial cells and aberrant production of cytokines by peritoneal fluid leukocytes, has been proposed as a mechanism which allows implantation and growth of ectopic endometrium. Cytokines are primary components of intercellular signaling between uterine epithelial and stromal cells, leukocytes, and the developing conceptus. Because their production is regulated by sex hormones, cytokines are well-placed to play a key role in the extensive tissue remodeling required to accommodate menstruation, implantation and pregnancy. Understanding this specialized hormonally-responsive mucosal immune system within the uterus will be critical to understanding the potential importance of the immune system in the pathogenesis of endometriosis. In this review, highlights of studies describing leukocyte populations, cytokines and cytokine receptors in uterine and ectopic endometrium and their proposed role in the regulation of immune processes and endometrial growth are presented, followed by a review of current data on immune aspects of endometriosis. Studies directed at investigating the hormonal regulation of cytokine secretion by uterine and peritoneal cell populations, and the effect of cytokines on endometrial proliferation, should provide a more complete understanding of their potential role in normal uterine growth and in the pathogenesis of endometriosis. 相似文献
996.
Ion channels contain extended columns of water molecules within their transbilayer pores. The dynamic properties of such intrapore water have been shown to differ from those of water in its bulk state. In previous molecular dynamics simulations of two classes of model pore (parallel bundles of Ala20 alpha-helices and antiparallel barrels of Ala10 beta-strands), a substantially reduced translational and rotational mobility of waters was observed within the pore relative to bulk water. Molecular dynamics simulations in the presence of a transpore electrostatic field (i.e., a voltage drop along the pore axis) have been used to estimate the resultant polarization (due to reorientation) of the intrapore water, and hence to determine the local dielectric behavior within the pore. It is shown that the local dielectric constant of water within a pore is reduced for models formed by parallel alpha-helix bundles, but not by those formed by beta-barrels. This result is discussed in the context of electrostatics calculations of ion permeation through channels, and the effect of the local dielectric of water within a helix bundle pore is illustrated with a simple Poisson-Boltzmann calculation. 相似文献
997.
GR Morrow JA Roscoe JJ Kirshner HE Hynes RJ Rosenbluth 《Canadian Metallurgical Quarterly》1998,6(3):244-247
Variegate porphyria (VP) is an autosomal dominant disorder characterised by a partial defect in the activity of protoporphyrinogen oxidase (PPO), and has recently been genetically linked to the PPO gene on chromosome 1q22-23 (Z=6.62). In this study, we identified a mutation in the PPO gene in a patient with VP and two unaffected family members. The mutation consisted of a previously unreported T to C transition in exon 13 of the PPO gene, resulting in the substitution of a polar serine by a non-polar proline (S450P). This serine residue is evolutionarily highly conserved in man, mouse, and Bacillus subtilis, attesting to the importance of this residue. Interestingly, the gene for Gardner's syndrome (FAP) also segregates in this family, independently of the VP mutation. Gardner's syndrome or familial adenomatous polyposis (FAP) is also an autosomal dominantly inherited genodermatosis, and typically presents with colorectal cancer in early adult life secondary to extensive adenomatous polyps of the colon. The specific gene on chromosome 5 that is the site of the mutation in this disorder is known as APC (adenomatous polyposis coli), and the gene has been genetically linked to the region of 5q22. 相似文献
998.
999.
1000.
M Kohler BE King NR Stevenson RB Schubank YM Shin RA Ristinen P Amaudruz PP Delheij DC Healey BK Jennings DF Ottewell G Sheffer GR Smith GD Wait JT Brack A Feltham M Hanna RR Johnson FM Rozon V Sossi D Vetterli P Weber N Grion R Rui EL Mathie R Tacik M Yeomans CA Gossett GJ Wagner JM Lee KS Chung 《Canadian Metallurgical Quarterly》1994,49(3):1715-1717