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991.
Antiviral immune responses of mice lacking interleukin-2 (IL-2) or IL-4 or both IL-2 and IL-4 (IL-2/4) were compared by using different viruses. Primary cytotoxic T-lymphocyte (CTL) responses against lymphocytic choriomeningitis virus (LCMV) were only moderately reduced in mice lacking IL-2 and were normal in mice lacking IL-4. Mice deficient in both interleukins exhibited variable and more strongly reduced but nevertheless in vivo protective LCMV-specific CTL responses. Similar results were obtained with vaccinia virus. Upon virus-specific restimulation in vitro, spleen cells from IL-2- and IL-2/4-deficient mice failed to generate CTL responses against virus-infected target cells, whereas the response of mice deficient in only IL-4 was comparable to that of control mice. The addition of IL-2 during in vitro restimulation completely restored the responses of both IL-2 and IL-2/4-deficient mice. T-helper-cell-independent immunoglobulin M and T-helper-cell-dependent immunoglobulin G antibody responses against vesicular stomatitis virus glycoprotein were within normal ranges for the various mutant mice. After LCMV infection, specific antibody responses against LCMV nucleoprotein were reduced four- to eightfold. These results show that mice lacking IL-2/4 have an overall tendency to exhibit more severely reduced CTL responses than IL-2- or IL-4-deficient mice. Nevertheless, and surprisingly, in vivo protective immune responses were mounted in the absence of IL-2/4, suggesting that besides a minor contribution from IL-4, other interleukins compensate in vivo for the lack of IL-2 in IL-2-deficient mice.  相似文献   
992.
993.
School of nursing faculty and nursing service personnel at an academic medical center in the South, collaboratively using a Delphi method, were able to prioritize the top three unit based clinical nursing research needs. The benefits were evident as research conducted at the staff level linked the research efforts with the quality improvement efforts on the Labor, Delivery and OB Receiving Units. The Delphi method, a consensus building technique, offered a clear, concise, accurate and non-threatening approach for staff nurses to participate in research.  相似文献   
994.
BACKGROUND: Vaccination against the hepatitis B virus (HBV) of health care staff during their studies would have the advantage of early prevention when the prevalence of infection is presumably low. METHODS: The population to be protected is made up of 1533 medical and nursing students. In those who accepted, anti-HBc was determined and information was obtained concerning circumstances of exposure to HBV. Vaccination was offered to all the cases of negative anti-HBc. Individuals receiving 3 doses of the vaccination (20 micrograms at 0, 1 and 6 months) were seen at 4-7 months of the last dose to determine the anti-HBs titers achieved. RESULTS: One thousand sixty-five students (70%) accepted inclusion into the prevaccination anti-HBc study and 1,029 (3.4%) were anti-HBc negative. Only older age and previous transfusions and jaundice were significantly associated to greater prevalence of infection by HBV. The adherence to 1, 2 or 3 doses of the vaccination was 96%, 94% and 87%, respectively. Following the 3 doses, > or = 10 UI/I of anti-HBs were detected in 97% of the cases studied with geometric measurement of the responders being 1580 U/I. The titer had an inverse relation which was not significant with age. CONCLUSIONS: The high participation in the program of anti-hepatitis B vaccination and the excellent immune response observed leads to the recommendation of systemic vaccination to future health care professionals during their study period. Furthermore, the low prevalence of previous HBV infection advises against previous detection of anti-HBc with immunization of the whole collective being more effective.  相似文献   
995.
996.
Two indices of motor unit recruitment, the ramp-force and repetitive-discharge thresholds, were compared in the first dorsal interosseus muscle of ten young and twelve elderly subjects. The purpose was to determine the effect of age on the relationship between the two recruitment thresholds and the spike-triggered average force of motor units. Each subject performed three tasks requiring isometric abduction of the left index finger: a maximum voluntary contraction (MVC), a ramp-and-hold contraction, and a repetitive-discharge task. The elderly subjects used coactivation of the antagonist muscle (second palmar interosseus) more frequently than the young subjects during the ramp-and-hold contraction. Many elderly subjects expressed difficulty with the controlled ramp-down phase of the ramp-and-hold contraction and preferred a coactivation strategy to a derecruitment strategy for this task. There were no differences due to age or gender in the ramp-force thresholds between the various groups. However, the normalized repetitive-discharge threshold was significantly less for the younger subjects and for the male subjects. Nonetheless, the two recruitment thresholds were able to predict the spike-triggered average force with similar success for both the young and the elderly subjects. These data suggest that the recruitment threshold of a motor unit in first dorsal interosseus was characterized equally well by either the ramp-force or repetitive-discharge measurement for both young and elderly subjects but that coactivation was used more frequently by the elderly subjects during the ramp-and-hold task.  相似文献   
997.
998.
OBJECTIVE: There is a paucity of longitudinal endocrine studies of infertile patients with oligomenorrhoea. We have assessed the frequency and quality of spontaneous follicular development and luteal function in patients with oligomenorrhoea and infertility (PCOS), and have related the observed criteria to circulating LH activity. DESIGN: Prospective detailed investigations in a cohort of unselected patients. PATIENTS: Infertile women with oligomenorrhoea (PCOS, n = 131) presenting to the infertility clinic at the Royal Infirmary, Glasgow. MEASUREMENTS: Patients were monitored with frequent plasma oestradiol (E2) concentration assessments over a minimum period of 3 weeks, starting more than 2 weeks after a menstrual bleed. When follicular maturation was identified the patient provided daily blood samples through to her ensuing menstrual bleed, and E2, progesterone, total testosterone, FSH and LH were assessed in these samples. Luteal phase progesterone profiles were assessed between the days LH surge +2 and LH surge +6 by means of a progesterone index. RESULTS: Forty-eight per cent of the patients showed evidence of follicular development. The oestradiol profiles in the patients showing follicular growth were normal, but the progesterone curve was sub-normal in the early luteal phase, due to a high proportion of deficient luteal phases. The mean LH concentrations were elevated in the whole group, but no difference was observed between the mean LH values for those patients showing spontaneous follicular development and those who did not, and the incidence of ovulation was similar in the normal LH and elevated LH groups. Similarly, no relation was established between LH and the quantitative assessment of luteal phase progesterone profiles (progesterone index), and the distribution of progesterone indices was similar in the normal LH and elevated LH groups. Testosterone concentrations were positively correlated with LH (p = 0.008) but not with the incidence of spontaneous follicular growth. There was no significant difference in the incidence of spontaneous ovulation between the patients with elevated or normal mean follicular phase testosterone concentrations. CONCLUSION: The data indicate that both LH and testosterone secretion in PCOS were closely linked, but that neither was directly linked to the incidence or inhibition of spontaneous follicular development in PCOS, or to the disturbance in luteal phase progesterone profiles.  相似文献   
999.
1000.
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