Healthy aged adul (24–26 months of age) and young adult (2–4 months of age) C57BL/6J male mice were assessed for intermale aggression, pup-killing behavior (infanticide), and circulating levels of testosterone (T). When compared to young adult male mice, aged adult males were highly variable in the exhibition of both androgen-dependent behaviors. Significant numbers of aged males exhibited deficits in aggression and pup-killing while other animals were as behaviorally active as their young male counterparts. Assessment of serum T showed that aging did not produce a reduction in levels of the steroid and individual variability in androgen-dependent behavior of aged males was not related to plasma levels of the hormone. When aged non-aggressive and non-killer males were exposed to supplemental T by way of subcutaneously implanted silastic capsules, circulating levels of the steroid were elevated but T-dependent behavior was not recovered. These findings, in combination with those previously reported for copulatory behavior, indicate that the deficits observed in the androgen-dependent behavior of aged male mice cannot be attributed to a breakdown in the production of testicular androgens. While neural refractoriness to T may account in part for deficits in androgen-dependent behavior of aged males, the variability that is observed in the reproductive behaviors of aged male rodents ultimately may be related to other sources of variation such as perinatal environment. 相似文献
Racial/ethnic and socioeconomic disparities in COVID-19 burden have been widely reported. Using data from the state health departments of Alabama and Louisiana aggregated to residential Census tracts, we assessed the relationship between social vulnerability and COVID-19 testing rates, test positivity, and incidence. Data were cumulative for the period of February 27, 2020 to October 7, 2020. We estimated the association of the 2018 Social Vulnerability Index (SVI) overall score and theme scores with COVID-19 tests, test positivity, and cases using multivariable negative binomial regressions. We adjusted for rurality with 2010 Rural–Urban Commuting Area codes. Regional effects were modeled as fixed effects of counties/parishes and state health department regions. The analytical sample included 1160 Alabama and 1105 Louisiana Census tracts. In both states, overall social vulnerability and vulnerability themes were significantly associated with increased COVID-19 case rates (RR 1.57, 95% CI 1.45–1.70 for Alabama; RR 1.36, 95% CI 1.26–1.46 for Louisiana). There was increased COVID-19 testing with higher overall vulnerability in Louisiana (RR 1.26, 95% CI 1.14–1.38), but not in Alabama (RR 0.95, 95% CI 0.89–1.02). Consequently, test positivity in Alabama was significantly associated with social vulnerability (RR 1.66, 95% CI 1.57–1.75), whereas no such relationship was observed in Louisiana (RR 1.05, 95% CI 0.98–1.12). Social vulnerability is a risk factor for COVID-19 infection, particularly among racial/ethnic minorities and those in disadvantaged housing conditions without transportation. Increased testing targeted to vulnerable communities may contribute to reduction in test positivity and overall COVID-19 disparities.
· Background: The aim of this study was to evaluate the focal electroretinogram (FERG), an objective indicator of outer
retinal function, in nonexudative age-related macular degeneration (NE-AMD), and to compare FERG results with morphological
lesions assessed by stereoscopic fundus photographs and fluorescein angiograms. · Methods: Twenty-five patients (25 eyes)
with bilateral NE-AMD (visual acuity of the study eyes ≥0.4) as well as 10 age- and sex-matched control subjects (10 eyes)
were evaluated. FERGs were recorded from the macular region (9°) in response to sinusoidal stimuli flickered at 32 Hz. Amplitude
and phase angle of the Fourier-analyzed FERG fundamental component were measured. Fundus lesions were graded from color slides
according to the Wisconsin age-related maculopathy grading system [15]. Fluorescein angiograms were evaluated by an image
analysis technique to compute the area with pathological hyperfluorescence (associated with drusen and/or retinal pigment
epithelial atrophy) within the macular (approximately 9°×9°) region. · Results: Compared to control eyes, NE-AMD eyes had
a reduction in the mean FERG amplitude (57% loss, P<0.001) with no phase changes. Amplitudes of individual affected eyes were negatively correlated with either the Wisconsin
grading score (r=–0.63, P<0.001) or the percentage area of pathological hyperfluorescence (r=–0.70, P<0.01). Eyes with minimal NE-AMD lesions (Wisconsin score ≤6) and normal acuity had a lower mean amplitude (47% loss, P<0.05) than that of control eyes. · Conclusions: The results indicate that, in NE-AMD, the FERG is altered in parallel with
the extent and severity of fundus lesions. However, a functional impairment of outer macular layers, which is detected by
FERG losses, could precede morphological changes typical of more advanced disease.
Received: 6 March 1998 Revised version received: 5 June 1998 Accepted: 17 June 1998 相似文献
Femoral neck fractures in the elderly are frequent, represent a serious health care problem, and have a significant impact on health costs. Reconstruction options using hip arthroplasty include bipolar hemiarthroplasty (HA) and total hip arthroplasty (THA). The purpose of this review is to discuss the indications, limitations, and pitfalls of each of these techniques. 相似文献
OBJECTIVES: The purpose of this study was to investigate the use of coronary magnetic resonance angiography (MRA) for assessing human epicardial coronary artery vasodilation. BACKGROUND: Coronary vasodilation plays a vital role in the human coronary circulation. Previous studies of epicardial coronary vasodilation have used invasive coronary angiography. Coronary MRA may provide an alternative noninvasive method to directly assess changes in coronary size. METHODS: Thirty-two subjects were studied: 12 patients (age 55 +/- 18 years) and 20 healthy subjects (age 34 +/- 4 years). High-resolution multi-slice spiral coronary MRA (in-plane resolution of 0.52 to 0.75 mm) was performed before and after sublingual nitroglycerin (NTG). Quantitative analysis of coronary vasodilation was performed on cross-sectional images of the right coronary artery (RCA). A time-course analysis of coronary vasodilation was performed in a subset of eight subjects for 30 min after NTG. Signal-to-noise ratio was also measured on the in-plane RCA images. RESULTS: Coronary MRA demonstrated a 23% increase in cross-sectional area after NTG (16.9 +/- 7.8 mm2 to 20.8 +/- 8.9 mm2, p <0.0001), with significant vasodilation between 3 and 15 min after NTG on time-course analysis. The MRA measurements had low interobserver variability (< or =5%) and good correlation with X-ray angiography (r=0.98). The magnitude of vasodilation correlated with baseline cross-sectional area (r=0.52, p=0.03) and age (r=0.40, p=0.019). Post-NTG images also demonstrated a 31% improvement in coronary signal-to-noise ratio (p = 0.002). CONCLUSIONS: Nitroglycerin-enhanced coronary MRA can noninvasively measure coronary artery vasodilation and is a promising noninvasive technique to study coronary vasomotor function. 相似文献
Purpose This study was designed to assess the long-term results of stapled hemorrhoidopexy in 291 patients with Grade III and Grade
IV hemorrhoids after a minimum follow-up of five years.
Methods Records of patients submitted to stapled hemorrhoidopexy for Grade III and Grade IV hemorrhoids between January 1999 and December
2002 were retrospectively analyzed. Long-term outcome was evaluated with a standardized questionnaire and an office visit,
including anorectal examination and rigid proctoscopy.
Results A total of 291 patients with Grade III (57.4 percent) and Grade IV (42.6 percent) hemorrhoids were evaluated. Intraoperative
(20.3 percent) and postoperative (4.8 percent) bleeding was the most frequent complication. The questionnaire was submitted
to all patients at a median follow-up of 73 (range 60–93) months. There were no symptoms related to hemorrhoids in 65.3 percent
of patients, moderate symptoms in 25.4 percent of patients, and severe symptoms in 9.3 percent of patients. Fifty-three (18.2
percent) patients had recurrence. Reoperation was necessary in 21 (7.2 percent) patients (4 in Grade III hemorrhoids and 17
in Grade IV hemorrhoids; P < 0.001), with no recurrent symptoms and/or prolapse. Patient satisfaction for operation was 89.7 percent.
Conclusions Stapled hemorrhoidopexy is a safe and effective treatment for Grade III and Grade IV hemorrhoids. Recurrence requiring reoperation
was higher in Grade IV hemorrhoids than in Grade III hemorrhoids.
Reprints are not available. 相似文献