Regulation of biosynthesis of aspartate family amino acids in the photosynthetic bacterium Rhodopseudomonas palustris

The four amino acids of the aspartate family (l-lysine, l-methionine, l-threonine, and l-isoleucine) are produced in bacteria by a branched biosynthetic pathway. Regulation of synthesis of early common intermediates and of carbon flow through distal branches of the pathway requires operation of a number of subtle feedback controls, which are integrated so as to ensure balanced synthesis of the several end products. Earlier studies with nonsulfur purple photosynthetic bacteria were instrumental in revealing the existence of alternative regulatory schemes, and in this communication we report on the control pattern of a representative of this physiological group not previously investigated, Rhodopseudomonas palustris. The results obtained from study of the properties of four key regulatory enzymes of the aspartate family pathway (-aspartokinase, homoserine dehydrogenase, homoserine kinase, and threonine deaminase) and of the effects of exogenous amino acids (i. e., the end products) on growth of the bacterium indicate that the control schema in Rps. palustris differs substantially from the schemes described for other Rhodopseudomonas species, but resembles the regulatory pattern observed in Rhodospirillum rubrum.Abbreviations A absorbancy - AK -aspartokinase - ASA aspartate -semialdehyde - DTT dithiothreitol - HS l-homoserine - HSDH homoserine dehydrogenase - HSK homoserine kinase - I l-isoleucine - KU Klett-Summerson photometer units - L l-lysine - M l-isoleucine - KU Klett-Summerson photometer units - L l-lysine - M l-methionine - ME -mercaptoethanol - PABA p-aminobenzoic acid - T l-threonine - TD threonine deaminase - RCV synthetic growth medium (see text) - YP agar medium containing 0.3% yeast extract, 0.3% peptone, and 1.5% agar - Y2T synthetic growth medium (see text)     

An experimental test of the efficiency of family selection in chickens

Summary Responses to single trait selection on individual phenotype and sire-family mean phenotype for survivor's egg weight and rate of lay were measured for a single generation in 13 replicates. Each replicate-selection criterion-trait subclass consisted of eight sire families or 72 females measured and was reproduced from the best 25% of the families or individuals. The realized heritability of egg weight was 0.39 and that of rate of lay was 0.31, both of which were significantly greater than zero but not significantly different from the predicted values based on halfsib correlations in the base population.The standardized response to sire-family selection was less than the response to individual selection for both traits and the difference was significant for rate of lay (0.10; 0.31) but not for egg weight (0.22; 0.39). The predicted responses to sire-family selection were less than those for individual selection for both traits, and the observed responses to sire-family selection were not significantly different from the predicted values for either trait.These experimental results do not disagree with the theoretical expectations of the relative efficiencies of individual and sire-family selection.Journal paper no. 7479, Purdue University, Agricultural Experiment Station. This investigation was conducted as a part of the cooperative research of the NC-89 Regional Poultry Breeding Project entitled Nature and Utilization of Genetic Variation in Poultry Improvement     

精神病患者家属心理健康状况调查研究

目的:探讨精神病患者家属的心理健康状况,并找出相关的影响因素.方法:对中山市91位住院以及门诊精神科病人家属进行问卷调查和访谈,采用的是症状自评量(SCL-90)和家庭疾病负担量表(Family Burden Scale of Disease).结果:家属心理健康状况与患者给家庭带来的负担存在明显的相关,患者患病对配偶的心理健康的影响明显大于对其他亲人或者朋友的影响(F=5.358,P＜0.001),15-30岁年龄段的SCL-90的得分要明显的高于其他年龄段(F=1.436,P＜0.01),而精神分裂症患者的家属SCL-90的得分也要明显高于其他疾病家属的得分.结论:影响家属心理健康的因素有多个方面,应该有针对性的采取家庭护理措施并加强家庭健康教育.     

震旦鸦雀种群生态的研究

震旦鸦雀是一种小型濒危鸟类,在IUCN和ICBP出版的红皮书中,共同认定为Ⅰ(Indeterminate)级。本文是作者于1985～1986年期间,对种群生态进行研究的首次报道。该鸟栖息于上海沿海芦苇滩中。种群密度1.21±0.57对/公顷。文中还论述数量变动和种群活动的变化规律。在奉贤沿海估计有290～387对。在越冬期中,剥取芦鞘内的寄生虫等为食。由于围垦不断发展,栖息地日益缩小,因此在生存上受到严重威胁。     

TGFβ Governs the Pleiotropic Activity of NDRG1 in Triple-Negative Breast Cancer Progression

In triple-negative breast cancer (TNBC), the pleiotropic NDRG1 (N-Myc downstream regulated gene 1) promotes progression and worse survival, yet contradictory results were documented, and the mechanisms remain unknown. Phosphorylation and localization could drive NDRG1 pleiotropy, nonetheless, their role in TNBC progression and clinical outcome was not investigated. We found enhanced p-NDRG1 (Thr346) by TGFβ1 and explored whether it drives NDRG1 pleiotropy and TNBC progression. In tissue microarrays of 81 TNBC patients, we identified that staining and localization of NDRG1 and p-NDRG1 (Thr346) are biomarkers and risk factors associated with shorter overall survival. We found that TGFβ1 leads NDRG1, downstream of GSK3β, and upstream of NF-κB, to differentially regulate migration, invasion, epithelial-mesenchymal transition, tumor initiation, and maintenance of different populations of cancer stem cells (CSCs), depending on the progression stage of tumor cells, and the combination of TGFβ and GSK3β inhibitors impaired CSCs. The present study revealed the striking importance to assess both total NDRG1 and p-NDRG1 (Thr346) positiveness and subcellular localization to evaluate patient prognosis and their stratification. NDRG1 pleiotropy is driven by TGFβ to differentially promote metastasis and/or maintenance of CSCs at different stages of tumor progression, which could be abrogated by the inhibition of TGFβ and GSK3β.     

Different effects of carbohydrate binding modules on the viscoelasticity of nanocellulose gels

Many cellulose degrading and modifying enzymes have distinct parts called carbohydrate binding modules (CBMs). The CBMs have been shown to increase the concentration of enzymes on the insoluble substrate and thereby enhance catalytic activity. It has been suggested that CBMs also have a role in disrupting or dispersing the insoluble cellulose substrate, but dispute remains and explicit evidence of such a mechanism is lacking. We produced the isolated CBMs from two major cellulases (Cel6A and Cel7A) from Trichoderma reesei as recombinant proteins in Escherichia coli. We then studied the viscoelastic properties of native unmodified cellulose nanofibrils (CNF) in combination with the highly purified CBMs to detect possible functional effects of the CBMs on the CNF. The two CBMs showed clearly different effects on the viscoelastic properties of CNF. The difference in effects is noteworthy, yet it was not possible to conclude for example disruptive effects. We discuss here the alternative explanations for viscoelastic effects on CNF caused by CBMs, including the effect of ionic cosolutes.     

Trochelioid A and B,new cembranoid diterpenes from the Red Sea soft coral Sarcophyton trocheliophorum

Chemical investigations of the soft coral Sarcophyton trocheliophorum, has led to the isolation of six cembranoids, two of which are new, Trochelioid A (1) and B (2), and one, 16-oxosarcophytonin E (3) isolated from nature for the first time. Additionally, two have been isolated from S. trocheliophorum for the first time (4 and 6). Structures were elucidated by employing extensive NMR and HR-FAB-MS experimentation.     

The WNT7A G204S mutation is associated with both Al-Awadi–Raas Rothschild syndrome and Fuhrmann syndrome phenotypes

Two syndromes are known to be associated with WNT7A mutations: Al-Awadi–Raas-Rothschild syndrome (AARRS) and Fuhrmann syndrome. Woods et al. (2006) showed that there is complete and partial loss of WNT7A function in these two syndromes respectively. Therefore, both syndromes have similar clinical features but the phenotype in Fuhrmann syndrome is less severe. The G204S mutation was previously reported to result in AARRS phenotype in three Saudi families. In the current communication, we report on a different unrelated Saudi patient with the same mutation but the patient had Fuhrmann syndrome phenotype. We believe this case is important because it questions the presence of a phenotype–genotype correlation in WNT7A mutations and because it demonstrates that the G204S mutation may be associated with both AARRS and Fuhrmann phenotypes.     

In Sync with the Family: Children and Partners Influence the Sleep‐Wake Circadian Rhythm and Social Habits of Women

Different factors have been proposed to influence morningness‐eveningness, biological rhythms, and sleep‐wake cycles, but few studies focused on the influence of social habits. Here, we focus on the influence of children and partners on the social habits of women at different stages of their lives and on synchronization within the family. One hundred and seventy‐nine women participated in the study and were allocated into four groups: women without children, pregnant women without children, pregnant women with children, and non‐pregnant mothers. Morningness was predicted by the presence of children, and earlier chronotype was predicted by the presence of children, pregnancy, and age. Average sleep duration was longest in pregnant women. The presence of children was responsible for a difference in rise times of approximately 1.5 h on the weekend. Subjective sleep‐onset latencies were shortest in women with children. The synchrony between partners (husband/wife) was 0.46 in women without children, 0.79 in pregnant women, 0.40 in women with children, and 0.56 between mother and child. Partners’ chronotypes were highly correlated, as were those of mother and child. This study suggests children have a strong influence on their mother's lifestyle and sleep‐wake rhythm, far beyond the first months of life, and that children are a more important social factor than the male partner.     

TAp73 Protein Stability Is Controlled by Histone Deacetylase 1 via Regulation of Hsp90 Chaperone Function

Histone deacetylases (HDACs) play important roles in fundamental cellular processes, and HDAC inhibitors are emerging as promising cancer therapeutics. p73, a member of the p53 family, plays a critical role in tumor suppression and neural development. Interestingly, p73 produces two classes of proteins with opposing functions: the full-length TAp73 and the N-terminally truncated ΔNp73. In the current study, we sought to characterize the potential regulation of p73 by HDACs and found that histone deacetylase 1 (HDAC1) is a key regulator of TAp73 protein stability. Specifically, we showed that HDAC1 inhibition by HDAC inhibitors or by siRNA shortened the half-life of TAp73 protein and subsequently decreased TAp73 expression under normal and DNA damage-induced conditions. Mechanistically, we found that HDAC1 knockdown resulted in hyperacetylation and inactivation of heat shock protein 90, which disrupted the interaction between heat shock protein 90 and TAp73 and thus promoted the proteasomal degradation of TAp73. Functionally, we found that down-regulation of TAp73 was required for the enhanced cell migration mediated by HDAC1 knockdown. Together, we uncover a novel regulation of TAp73 protein stability by HDAC1-heat shock protein 90 chaperone complex, and our data suggest that TAp73 is a critical downstream mediator of HDAC1-regulated cell migration.