Buffering and H+ ion dynamics in muscle tissues

After anaerobic activity with release of large quantities of intermediary metabolic end products, further energy production critically depends on rapid elimination of H+ ions from the muscle tissues to secure key enzymatic activities. The involved processes, interactions and interrelationships of mechanisms have been analyzed on the basis of a physiological model and available experimental data. The H+ elimination from muscle tissue is a multifactorial process primarily governed by the capillary H+ transport capacitance, effected by buffering capabilities of intracellular and capillary fluids compartments, by dynamically interrelated regulation of intracellular and extracellular pH, by the magnitude and quality of convective perfusional transfer and further factors. Model calculations strongly resemble experimental data obtained in isolated perfused muscles and suggest that discrepancies between disparate literature data are attributable to experimental limitations.     

Reduced expression of the global regulator protein CsrA in Legionella pneumophila affects virulence-associated regulators and growth in Acanthamoeba castellanii

Legionella bacteria have a developmental cycle in which they go from existing in the aquatic environment to replicating inside eukaryotic host cells. The adaptation to the new environment requires an efficient regulatory system. Overexpression of CsrA, a global regulatory protein found in a variety of gram-negative bacteria has been shown to suppress virulence-associated traits in Legionella pneumophila. Since evidence resulting only from overproduction may not be sufficient to validate the role of a regulatory protein, a csrA mutant strain, CsrA(-), with a drastically reduced production of CsrA, was created. Using RNA slot blots and Western blotting it was shown that fliA and flaA, genes which contribute to flagellation, were expressed early in the mutant. Additionally, in CsrA(-) the levels of the stationary-phase sigma factor, RpoS, and a recently described regulator of virulence traits, LetE, were increased. Growth curves of CsrA(-) bacteria were delayed with pigment production occurring at the same OD578 but at reduced levels in the mutant. Replication ability of the CsrA(-) mutant in amoebae was also affected. Based on these results, we could show that CsrA is involved in the regulation of the bacterial switch from the replicative to the transmissible form.     

The yeast Pho80–Pho85 cyclin–CDK complex has multiple substrates

The Pho85–Pho80 cyclin–CDK (cyclin-dependent protein kinase) complex of Saccharomyces cerevisiae functions as a key regulator of the phosphate-repressible acid phosphatase system. We have further characterized the Pho85–Pho80 kinase complex and identified the Pho80 cyclin subunit and the Pho81 CDK inhibitor as substrates of the Pho85 protein kinase. The phosphorylation sites within Pho80 have been identified at Ser²³⁴ and Ser²⁶⁷. Of the two sites, phosphorylation of Ser²³⁴ is required for Pho80 function, to form an active kinase complex and repress acid phosphatase expression. Evidence suggests that the activity of Pho81 is regulated by a post-translational modification and therefore that Pho85-mediated phosphorylation of Pho81 may alter its ability to function as a CDK inhibitor. Thus, the control of acid phosphatase expression involves the phosphorylation of several of the regulatory components of the system.     

Regulation, religious experience, and epilepsy: a lens on complementary therapies

Complementary and alternative medical (CAM) therapies include chiropractic, acupuncture and traditional Oriental medicine, massage therapy, and herbal remedies; mind-body therapies (such as meditative practices and visualization); and folk practices and religious healing. Of these, modalities based on spiritual healing create a number of conundrums for the clinician, including legal, regulatory, and ethical issues. Further, the historic relationship between the study of epilepsy and religious experience suggests particular, potential associations between CAM therapies (and especially spiritual healing) and care for epileptic patients. There are at least two dimensions to this exploration: first, the widespread use of spiritual healing for treatment of epilepsy; and second, the hypothesized connection between epileptic seizures and mystical states. A number of legal rules help address potential abuse of authority by health care professionals, and include: (1) medical licensure; (2) scope of practice; (3) professional discipline; (4) malpractice; and (5) fraud. This article offers a preliminary resource for clinicians interested in these topics.     

生命科学家社会责任的特征和行为规范

生命科学家社会责任具有全人类性、全局性和全过程性的共同特征；国际组织和我国科研机构对生命科学家提出的伦理规范要求；诚信、奉献、创新、宽容、关怀、合作应是生命科学家最重要的伦理行为准则。     

中青年癌症患者住院期间反刍性沉思现状及影响因素的调查研究

目的 了解中青年癌症患者反刍性沉思水平并分析其影响因素,为临床医护人员实施个体化干预提供依据。方法 采用一般资料调查表、事件相关反刍性沉思问卷和情绪调节量表对山东省某三级甲等医院肿瘤科共373例癌症患者进行调查。结果 癌症患者的反刍性沉思总得分为（28.64±12.13）分,其中侵入性反刍性沉思和目的性反刍性沉思得分分别为（13.92±6.42）分和（14.72±6.80）分;表达抑制、宗教信仰共解释侵入性反刍性沉思总变异的14.2%;表达抑制、家庭关系、文化程度共解释目的性反刍性沉思总变异的22.1%。结论 中青年癌症患者的反刍性沉思处于中等偏下水平,表达抑制、宗教信仰、家庭关系及文化程度是癌症患者反刍性沉思的重要影响因素。临床医护人员需针对不同特征的癌症患者采取相应的个体化干预,帮助患者采取积极的态度应对疾病,促进其身心康复。