Activity measurements of the high-energy pure beta-emitters 89Sr and 90Y by the TDCR efficiency calculation technique.

The absolute activities of the pure beta-emitters 89Sr and 90Y have been determined by a direct method, namely the triple-to-double coincidence ratio (TDCR) efficiency calculation technique. This undertaking has extended further the number of radionuclides that have been standardized by this non-extrapolation liquid scintillation (LS) method. Both measurements were carried out within the framework of international key comparisons under the auspices of the International Bureau of Weights and Measures (BIPM). The TDCR results agreed well with those of other participating national laboratories, most using alternative (tracer) methods.     

Delta hepatitis virus infection in China

To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China.     

Neuronal cell bodies in the hypothalamic paraventricular nucleus mediate stress-induced renin and corticosterone secretion

The present studies were undertaken to determine the involvement of neurons in the hypothalamic paraventricular nucleus (PVN) in stress-induced renin secretion. The stressor was a 10-min conditioned emotional response (CER) paradigm. Bilateral electrolytic lesions in the PVN prevented the stress-induced increase in plasma renin activity (PRA), and plasma renin concentration (PRC). Stress-induced corticosterone secretion was also blocked, supporting the histological verification and suggesting that the lesion included corticosterone-releasing factor neurons in the PVN. Stress-induced renin secretion appears to be restricted to the PVN, as electrolytic lesions in the nucleus reuniens, dorsal and caudal to the PVN, did not prevent the stress-induced increase in either PRA or PRC. The next step was to determine whether cell bodies in the PVN or fibers of passage through the PVN mediate the stress-induced increase of these hormones. For this purpose, bilateral stereotaxic injections of the cell-selective neurotoxin ibotenic acid (10 micrograms/microliter; 0.3 microliters per side) were performed 14 days prior to the stress procedure. Histological evaluation of the tissue revealed cell death and lysis in the PVN. Ibotenic acid injection into the PVN prevented the effect of stress on PRA, PRC and corticosterone levels. None of the lesions prevented the stress-induced rise in plasma prolactin concentration. These results suggest that neurons in the PVN play an important role in mediating stress-induced increases in renin and corticosterone but not prolactin secretion.     

Pathways from first health care seeking to diagnosis: obstacles to tuberculosis care in rural China.

OBJECTIVE: To examine health care seeking pathways for patients with tuberculosis (TB) and barriers related to these pathways in counties under the National TB Control Programme in rural China. METHODS: A cross-sectional study was conducted in two counties of east China in 2004-2005. A total of 557 TB patients were recruited and interviewed by physicians at the time of TB diagnosis. RESULTS: Of 557 participants, 13.3% had presented to a specialised county TB dispensary (CTD) directly after onset of symptoms, 31.4% had first sought care at a village health station and 51.2% had visited a township or county hospital first. The proportion of referral by a first health care provider to a CTD was highest in county level hospitals (73.5%) and lowest in village health stations (21.7%). The most prompt pathway from first health care seeking to TB diagnosis was to visit a CTD directly, with a median provider's delay of only one day. There was an increase in provider's delay when more health facilities were involved. CONCLUSION: To improve direct referral from general health care providers, especially village health care workers, to TB specialists would significantly shorten the delays in TB diagnosis in rural China.     

Changes in sexual behavior during a safety and feasibility trial of a microbicide/diaphragm combination: an integrated qualitative and quantitative analysis.

If proven effective, vaginal microbicides and diaphragms will likely be part of a larger HIV prevention model that includes condoms and other prevention strategies. It is, therefore, important to understand how introducing new prevention methods may affect overall patterns of sexual risk behavior. Data presented were collected as part of a safety and feasibility study of ACIDFORM gel with a diaphragm among 120 women in South Africa. Interviews were administered at enrollment and months 1, 3, 5, and 6 of the trial. Focus groups were conducted at trial exit. Frequency of sex increased significantly after enrollment. This increase appears to be owing to perceived protection from HIV and greater sexual pleasure afforded by the gel. Male condom use was high overall but increased significantly from enrollment. Data suggest this is because of increased partner involvement, increased negotiating power afforded by study participation, and provision of free condoms perceived to be of high quality.     

Microbiological aspects of heat sterilization of drugs

International Journal of Clinical Pharmacy - In order to calculate the minimum sterilization process conditions to obtain the generally accepted sterility level (less than 1·10?6...     

Effects of intracerebral estradiol on the dorsal immobility response in the rat

The effects of intracerebral implants of 17 beta estradiol and cholesterol in five brain regions were tested on the duration of the dorsal immobility response in ovariectomized female rats. The dorsal immobility response was significantly prolonged by 4-hr implants of 17 beta estradiol in the dorsal striatum and nucleus accumbens, but not in the cortex, the globus pallidus, or the substantia nigra pars compacta. These data further support previous evidence that estradiol acts directly on the striatum to affect behavior in the rat.