St John's wort for depression--an overview and meta-analysis of randomised clinical trials.

OBJECTIVE--To investigate if extracts of Hypericum perforatum (St John''s wort) are more effective than placebo in the treatment of depression, are as effective as standard antidepressive treatment, and have fewer side effects than standard antidepressant drugs. DESIGN--Systematic review and meta-analysis of trials revealed by searches. TRIALS--23 randomised trials including a total of 1757 outpatients with mainly mild or moderately severe depressive disorders: 15 (14 testing single preparations and one a combination with other plant extracts) were placebo controlled, and eight (six testing single preparations and two combinations) compared hypericum with another drug treatment. MAIN OUTCOME MEASURES--A pooled estimate of the responder rate ratio (responder rate in treatment group/responder rate in control group), and numbers of patients reporting and dropping out for side effects. RESULTS--Hypericum extracts were significantly superior to placebo (ratio = 2.67; 95% confidence interval 1.78 to 4.01) and similarly effective as standard antidepressants (single preparations 1.10; 0.93 to 1.31, combinations 1.52; 0.78 to 2.94). There were two (0.8%) drop outs for side effects with hypericum and seven (3.0%) with standard antidepressant drugs. Side effects occurred in 50 (19.8%) patients on hypericum and 84 (52.8%) patients on standard antidepressants. CONCLUSION--There is evidence that extracts of hypericum are more effective than placebo for the treatment of mild to moderately severe depressive disorders. Further studies comparing extracts with standard antidepressants in well defined groups of patients and comparing different extracts and doses are needed.     

铜绿假单胞菌全局调控因子RsmA的缺失影响2个吩嗪基因簇的表达

[目的]为了研究铜绿假单胞菌全局调控因子RsmA对两个吩嗪(Phenazine)合成基因簇phz1和phz2的调控方式与机制.[方法]采用基因缺失和抗性基因(gentamycin resistance cassette,aacC1)插入相结合的策略构建了rsmA基因缺失突变株PA-RG ;通过构建互补表达载体和过表达载体,进一步确认RsmA对绿脓菌素的调控作用 ;采用电转化方法将构建的翻译融合表达载体pMEZ1(phz1'-'lacZ)和pMEZ2(phz2'-'lacZ)分别导入铜绿假单胞菌突变株PA-RG和野生株PAO1,采用Miller法测定融合β-半乳糖苷酶活性.[结果]在GA培养基中,互补分析和过表达分析表明,RsmA抑制绿脓菌素的合成.此外,pMEZ1在突变株PA-RG中的表达增强,为野生株的2-3倍 ;而pMEZ2在突变株PA-RG中的表达降低,野生株是突变株的2倍.[结论]由此初步判定,铜绿假单胞菌全局调控因子RsmA对两个不同吩嗪合成基因簇的调控作用具有特异性,在一定程度上RsmA负调控phz1,正调控phz2.     

Comparative assessment of the sensitivity of oilseed rape and wheat to limited water supply

The drought‐sensitivity of oilseed rape (OSR, Brassica napus cv. SW Landmark) was investigated, using the more widely studied crop species wheat (Triticum aestivum cv. Tybalt) as a benchmark. The water relations of OSR and wheat were compared in lysimeter and controlled environment experiments to test the hypothesis that the growth of OSR is restricted to a greater extent by soil drying than wheat and to determine whether the greater sensitivity results from differences in root or shoot traits. Plants were grown, with or without irrigation, in 1.2 m tall lysimeters packed with a sandy clay loam soil. The experiment was conducted in an open‐sided glasshouse to encourage air flow and to resemble a field environment as far as possible; plant population densities were equivalent to commercial crops. Irrigated OSR (evapo)transpired more water than wheat (498 vs. 355 mm), but had a comparable water use efficiency (WUE; 4.1 vs. 4.4 g DW mm^?1 H₂O). Oilseed rape showed a greater reduction in above‐ground growth (52% vs. 21%) and a smaller increase in WUE (27% vs. 45%) when water was withheld. Oilseed rape also responded to soil drying at a lower soil moisture deficit than wheat; transpiration rates fell below the potential of irrigated plants when plant available water remaining in the soil profile declined from 54 to 23% compared to 38 to 9% for wheat. The root hydraulic conductivity of young OSR plants, measured on root surface area basis, was about twice that of wheat, and was comparable on a root length basis. The results show that OSR was more sensitive to a restricted water supply than the benchmark species wheat and that the greater sensitivity resulted from differences in shoot, rather than root, characteristics. The root system of OSR was at least as efficient as wheat at extracting water from soil.     

The effect of body temperature on the hunting response of the middle finger skin temperature

The relationship between body temperature and the hunting response (intermittent supply of warm blood to cold exposed extremities) was quantified for nine subjects by immersing one hand in 8°C water while their body was either warm, cool or comfortable. Core and skin temperatures were manipulated by exposing the subjects to different ambient temperatures (30, 22, or 15°C), by adjusting their clothing insulation (moderate, light, or none), and by drinking beverages at different temperatures (43, 37 and 0°C). The middle finger temperature (T _fi) response was recorded, together with ear canal (T _ear), rectal (T _re), and mean skin temperature (Tˉ _sk). The induced mean T _ear changes were −0.34 (0.08) and +0.29 (0.03)°C following consumption of the cold and hot beverage, respectively. Tˉ _sk ranged from 26.7 to 34.5°C during the tests. In the warm environment after a hot drink, the initial finger temperature (T _fi,base) was 35.3 (0.4)°C, the minimum finger temperature during immersion (T _fi,min) was 11.3 (0.5)°C, and 2.6 (0.4) hunting waves occurred in the 30-min immersion period. In the neutral condition (thermoneutral room and beverage) T _fi,base was 32.1 (1.0)°C, T _fi,min was 9.6 (0.3)°C, and 1.6 (0.2) waves occurred. In the cold environment after a cold drink, these values were 19.3 (0.9)°C, 8.7 (0.2)°C, and 0.8 (0.2) waves, respectively. A colder body induced a decrease in the magnitude and frequency of the hunting response. The total heat transferred from the hand to the water, as estimated by the area under the middle finger temperature curve, was also dependent upon the induced increase or decrease in T _ear and Tˉ _sk. We conclude that the characteristics of the hunting temperature response curve of the finger are in part determined by core temperature and Tˉ _sk. Both T _fi,min and the maximal finger temperature during immersion were higher when the core temperature was elevated; Tˉ _sk seemed to be an important determinant of the onset time of the cold-induced vasodilation response. Accepted: 29 April 1997     

Breast cancer risk and 6q22.33: combined results from Breast Cancer Association Consortium and Consortium of Investigators on Modifiers of BRCA1/2

Recently, a locus on chromosome 6q22.33 (rs2180341) was reported to be associated with increased breast cancer risk in the Ashkenazi Jewish (AJ) population, and this association was also observed in populations of non-AJ European ancestry. In the present study, we performed a large replication analysis of rs2180341 using data from 31,428 invasive breast cancer cases and 34,700 controls collected from 25 studies in the Breast Cancer Association Consortium (BCAC). In addition, we evaluated whether rs2180341 modifies breast cancer risk in 3,361 BRCA1 and 2,020 BRCA2 carriers from 11 centers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Based on the BCAC data from women of European ancestry, we found evidence for a weak association with breast cancer risk for rs2180341 (per-allele odds ratio (OR)?=?1.03, 95% CI 1.00-1.06, p?=?0.023). There was evidence for heterogeneity in the ORs among studies (I(2)?=?49.3%; p?=?<0.004). In CIMBA, we observed an inverse association with the minor allele of rs2180341 and breast cancer risk in BRCA1 mutation carriers (per-allele OR?=?0.89, 95%CI 0.80-1.00, p?=?0.048), indicating a potential protective effect of this allele. These data suggest that that 6q22.33 confers a weak effect on breast cancer risk.     

Elevated Fmr1 mRNA levels and reduced protein expression in a mouse model with an unmethylated Fragile X full mutation

The human FMR1 gene contains a CGG repeat in its 5' untranslated region. The repeat length in the normal population is polymorphic (5-55 CGG repeats). Lengths beyond 200 CGGs (full mutation) result in the absence of the FMR1 gene product, FMRP, through abnormal methylation and gene silencing. This causes Fragile X syndrome, the most common inherited form of mental retardation. Elderly carriers of the premutation, defined as a repeat length between 55 and 200 CGGs, can develop a progressive neurodegenerative syndrome: Fragile X-associated tremor/ataxia syndrome (FXTAS). In FXTAS, FMR1 mRNA levels are elevated and it has been hypothesised that FXTAS is caused by a pathogenic RNA gain-of-function mechanism. We have developed a knock in mouse model carrying an expanded CGG repeat (98 repeats), which shows repeat instability and displays biochemical, phenotypic and neuropathological characteristics of FXTAS. Here, we report further repeat instability, up to 230 CGGs. An expansion bias was observed, with the largest expansion being 43 CGG units and the largest contraction 80 CGG repeats. In humans, this length would be considered a full mutation and would be expected to result in gene silencing. Mice carrying long repeats ( approximately 230 CGGs) display elevated mRNA levels and decreased FMRP levels, but absence of abnormal methylation, suggesting that modelling the Fragile X full mutation in mice requires additional repeats or other genetic manipulation.     

Hysterographic appearance and uterine histology at different stages of the reproductive cycle and after progestagen treatment in the domestic cat

The aims of this study were to characterize the hysterographic and histological features of the uteri and to perform immunohistochemistry with proliferating cell nuclear antigen (PCNA) in the cat endometrium at various stages of the reproductive cycle and after treatment with exogenous progestagen. Seventy-four female domestic cats submitted for routine ovariohysterectomy were categorized into six groups: inactive (n=20), follicular (n=9), luteal (n=18), and postpartum (n=12) stages of the reproductive cycle; cats given medroxyprogesterone acetate for estrus prevention (MPA group) (n=12); and cats with uterine pathological lesions (n=3). Hysterography was performed and the relation of the uterine and luminal shape in the hysterogram with the stage of the reproductive cycle as well as with any pathological conditions of the uterus was evaluated. The uteri and ovaries were thereafter surgically removed and sectioned for histological examination. The PCNA was used to demonstrate the expression of endometrial epithelial cell growth. The hysterographic appearance was found to differ between the six groups of cats. A straight uterine cavity was characteristic for cats in the inactive stage, whereas a wavy uterine cavity was characteristic for cats in the follicular stage. In the luteal stage, the luminal cavity of the uteri differed in shape with increasing progesterone concentration from straight to irregular wavy or coiled. The coil shaped uterine lumen seen in the MPA treated and pathological groups was considered also to be an expression of a progestagenic effect. Waviness and coiling of the uterine lumen was related to a proliferation of the endometrial glands, whereas irregular filling defects were indicative of endometrial cystic changes. This study is the first to demonstrate the expression of PCNA in the cat endometrium although no differences were found between the six groups of cats. The hysterographic appearance was found to differ according to stage of the reproductive cycle and pathological conditions. Thus, a normative hysterogram is now available for diagnosing the reproductive stage and uterine changes in cats developing endometrial hyperplasia with and without cystic changes.     

Large-scale observational studies of hypericum extracts in patients with depressive disorders—a systematic review

We present a systematic review of observational studies of hypericum extracts in the treatment of depressive disorders. We included non-randomized studies with at least 100 patients suffering from depressive disorders treated with hypericum mono-preparations for at least 4 weeks, which reported clinical outcomes. Potentially relevant studies were identified through searches in electronic databases (Medline, PubMed), contacts with manufacturers, and handsearching of proceedings of phytomedicine congresses. Information on patients, interventions, methods an results were extracted by two reviewers. Sixteen studies including a total of 34,804 (range 101-11,296) patients met the inclusion criteria. Most studies investigated short-term effects (4-6 weeks) in patients with mild to moderate depression. Response rates (according to physician assessment) varied between 65% and 100%, the proportion of patients dropping out due to side effects varied between 0.0% and 2.8%. Two studies investigated long-term effects (52 weeks). Reponse rates were 60% and 69%, respectively, and the proportions of patients dropping out due to side effects were 3.4% and 5.7%, respectively. Serious side effects or interactions were not reported in any study. The quality of reporting was insufficient in the majority of publications. The available studies show that hypericum extract are well tolerated and seem to be effective in routine treatment of mild to moderate depressive disorders.     

Comparative tests of ectoparasite species richness in seabirds

Background  

The diversity of parasites attacking a host varies substantially among different host species. Understanding the factors that explain these patterns of parasite diversity is critical to identifying the ecological principles underlying biodiversity. Seabirds (Charadriiformes, Pelecaniformes and Procellariiformes) and their ectoparasitic lice (Insecta: Phthiraptera) are ideal model groups in which to study correlates of parasite species richness. We evaluated the relative importance of morphological (body size, body weight, wingspan, bill length), life-history (longevity, clutch size), ecological (population size, geographical range) and behavioural (diving versus non-diving) variables as predictors of louse diversity on 413 seabird hosts species. Diversity was measured at the level of louse suborder, genus, and species, and uneven sampling of hosts was controlled for using literature citations as a proxy for sampling effort.