Melatonin Lowers Plasma Prolactin Levels in Female Red Deer (Cervus elaphus)

The aim of the study was to determine the effect of exogenous melatonin treatment on circulating prolactin levels in red deer. Melatonin was administered from 12 June 1984 (day 1) to lactating and non-lactating hinds in the feed daily at 1600 h, and to non-lactating hinds by a subcutaneous implant. Average concentrations (ng/ml) of prolactin in plasma taken serially over 15-h periods were significantly higher for untreated hinds than for melatonin-treated animals on day 15 whether lactating (66-133 v. 23-28, P less than 0.05) or non-lactating (28-174 v. 8-13, P less than 0.01), remained higher on day 36 (lactating: 41-152 v. 15-21, P less than 0.05; non-lactating: 21-50 v. 1-7, P less than 0.001) but had decreased to similar levels on day 72 (lactating: 5-24 v. 7-17; non-lactating: 2-9 v. 0-4). The advanced reduction in plasma prolactin for all melatonin-treated hinds was associated with an advanced onset of seasonal breeding activity.     

泰安市流行性出血热(EHF)发病季节和人群分布

在这篇文章中,应用圆形分布法计算了泰安市1984—1985两年流行出血热的发病平均日期,分别为1984年11月5号和1985年11月11号,两年合计的平均发病日期为11月9号。另外,还分析了发病的年龄和职业。这将为预防工作提供准确的科学数据。     

Before-birth climatologic data may play a role in the development of allergies in infants

While an exacerbation in allergic symptoms corresponding to seasons has long been reported, few studies have investigated the association between the season of birth and allergic disorders. The aim of this study was to investigate whether the climatologic data before and after birth affected the incidence of atopic dermatitis (AD) and the results of allergy-related blood tests in early infancy. From February 1995 to January 2000, 2136 infants were tested for AD and followed for 12 months. AD patients were tested by using allergy-related blood tests. Data were compared according to the month of birth and the climatologic data using a computed statistical software package. Six hundred and thirty infants had AD before 12 months old, and significant differences were found according to the season of birth (p < 0.0001). Infants born in spring showed the lowest (22.3%) incidence, while those born in autumn showed the highest (34.6%). In 369 patients, total serum IgE levels, and serum specific IgE levels with egg white at 3 months old were also different according to the season of birth. All of these levels were lower in patients born in spring and summer, and higher in patients born in autumn and winter. Furthermore, the cumulative sunshine amount during the 3 months before and after birth was inversely correlated, while the average temperature over the 3 months before birth was positively correlated to the incidence of AD according to the month of birth. The climatologic data around birth may play an important role in whether an infant develops allergies.     

Prevalence of reported sleeplessness in northern Norway in relation to sex, age and season

As part of a comprehensive population health survey in the municipality of Tromsø, north of the Arctic Circle, men between 20 and 54 years and women between 20 and 49 years were presented a questionnaire containing questions about sleeplessness and its possible association with season. Of the 14,667 respondents, 41.7% of the women and 29.9% of the men said they were sometimes bothered by insomnia. Insomnia not associated with any special time of the year was reported by 16.9% of women and 16.2% of men; insomnia in the "dark period" (midwinter insomnia) was reported by 17.6% of women and 9.0% of men; insomnia in the midnight-sun period or in spring or autumn was much less common. Difficulty falling asleep was the most common type of insomnia, especially in winter and summer. Overall, the frequency of insomnia increased with increasing age, but with some notable differences with regard to type (initial insomnia showed little relation to age, whereas middle and late insomnia increased markedly with age) and seasonal type (insomnia in the midnight-sun period decreased with age, whereas the other seasonal types increased with age).     

住院精神分裂症患者2271例发病高峰时间的圆形统计分析

目的：分析精神分裂症病人的发病高峰时间,为精神病防治提供参考。方法：对１９９３ 年～１９９７ 年五年间首次发病入院的精神分裂症病人２２７１ 人做发病高峰时间的圆形统计分析。结果：精神分裂症病人的发病高峰时间差异具有显著性（ｒ＝ ０．０６９３,Ｐ＜ ０．０５）,发病高峰时间约为２ 月２６ 日,按季节应为冬末春初。结论：此季节应特别注意加强精神疾病的防治工作。     

Evidence that Dopaminergic Neurons are not Involved in the Negative Feedback Effect of Testosterone on Luteinizing Hormone in Rams in the Non-Breeding Season

In this study we tested the hypothesis that the negative feedback effects by testosterone on the secretion of luteinizing hormone (LH) in rams involves dopaminergic afferents to gonadotrophin-releasing hormone neurons operating via D(2) receptors in the non-breeding season. In the first experiment, three groups (n = 5) of rams were treated with an intravenous injection of vehicle or 10 or 20 mg of the dopaminergic D(2) antagonist pimozide and jugular venous samples were collected every 10 min for 3 h before and 3 h following treatment. The plasma was assayed for LH. Three groups of ewes (n = 4 to 5) were similarly treated. There were no significant effects of treatment of the rams with pimozide on the plasma concentrations of LH or LH pulse frequency or pulse amplitude and the response of individual rams in each group was inconsistent. In contrast, treatment of the ewes with 20 mg pimozide significantly (P<0.001) increased the mean (± SEM) plasma LH concentrations (pretreatment 0.37 ± 0.04; post-treatment 2.42±0.25 ng/ml) and decreased (P<0.001) the LH inter-pulse interval (pretreatment 180.0; post-treatment 88.0±11.1 min); the 10 mg dose of pimozide did not affect these parameters. In the second experiment, two groups of rams (n = 5) and ewes (n = 7) were treated with an intravenous injection of vehicle or 0.33 mg pimozide/kg liveweight and jugular venous samples were collected every 10 min for 2 h before and 6 h following treatment. As in the first experiment, the mean (± SEM) concentrations of plasma LH were not affected by treatment with pimozide in the rams (pretreatment 0.18 ± 0.25; post-treatment 0.43 ± 0.14 ng/ml) but were significantly (P<0.05) increased in the ewes (pretreatment 1.12±0.22; post-treatment 1.93 ± 0.23 ng/ml). In the third experiment, four adult rams were castrated and 3 weeks later each animal had two cannulae inserted to allow injection into the lateral cerebral ventricles. Vehicle or 100 μg pimozide was injected intracerebroventricularly and blood samples were collected as in the other experiments. A Latin Square design was used so that each animal received each treatment (n = 4). This procedure was repeated after the animals had been injected (intramuscularly) with 16 mg testosterone propionate twice daily for at least 7 days. Treatment with testosterone propionate significantly decreased (P < 0.001) the plasma concentrations of LH (pre-treatment 7.71±0.27; post-treatment 0.75 ± 0.27 ng/ml; mean ± SEM) and follicle-stimulating hormone (pre-treatment 79.61±8.47; post-treatment 42.53 ± 6.08 ng/ml; mean ± SEM) and increased the mean (± SEM) LH inter-pulse interval (53.14 ± 3.58 min pre-treatment and 292.5 ± 32.94 min post-treatment) but had no effect on the amplitude of LH pulses (pre-treatment 3.61 ± 0.36; post-treatment 1.86±1.76 ng; mean ± SEM). Pimozide had no effect on the plasma concentrations of gonadotrophins. These results suggest that, in the ram, dopaminergic neurons do not influence the gonadotrophin-releasing hormone neurons via D(2) receptors in the non-breeding season and are not involved in the negative feedback effect of testosterone on the secretion of gonadotrophins. Conversely, our data suggest that such a mechanism is integral to the negative feedback effects of oestradiol on LH in anoestrous ewes. Finally, it also appears that the steroid-independent suppression of the secretion of gonadotrophins during the non-breeding season in rams is not mediated via D(2) receptors.     

肝硬化上消化道出血与时间及季节的相关性分析

目的探讨肝硬化门静脉高压患者上消化道出血与时间及季节的相关性。方法回顾性分析225例患者440次上消化道出血的时间和季节。结果1天24小时12个时间段中,19-21时为上消化道出血的第1个高峰期,23-1时为第2个高峰期,5-7时为第3个高峰期。发生在夜间的有298次,发生率为67.7%;发生在白天的有142次,发生率为32.3%,夜间出血发生率明显高于白天。冬春季的出血发生率明显高于夏秋季,两者比较有显著意义(P<0.01)。结论肝硬化患者上消化道出血的发生有明显的时间及季节相关性。