60μg/1.0ml重组乙型肝炎疫苗(酵母)对16岁以上健康人群一针免疫的血清学效果研究

目的系统评价60μg/1.0 ml重组乙型肝炎疫苗(酵母)对健康成人一针免疫的血清学效果,补充和完善我国乙肝防控快速产生乙肝抗体的免疫策略。方法对16岁以上凡自愿接种的健康成人即不论以往有无乙肝疫苗接种史者都接种一针60μg/1.0 ml重组乙型肝炎疫苗(酿酒酵母),并从中随机抽取96名接种对象,采集免疫前和免疫后一个月的血清,采用化学微粒子发光法(CLIA)进行乙肝表面抗体检测,计算免疫前后血清标本乙肝表面抗体阳转率。结果接种后四倍增长和达保护水平以上的乙肝表面抗体阳转率为93.8%。其中接种前血清乙肝表面抗体阴性者42人,接种后四倍增长和达保护水平以上者的比率为85.7%。接种后乙肝表面抗体≥10 mIU/ml者的比率为88.5%。结论说明对16岁以上健康人群接种一针60μg/1.0 ml重组乙型肝炎疫苗有很好的免疫学效果。     

Yeasts encoding tumour antigens in cancer immunotherapy

Immunotherapy for cancer represents an attractive therapeutic target because of its specificity and lack of toxicity, but products investigated so far have been limited by neutralisation, complexity of manufacturing and requirement for patient-specific products. Recombinant yeast cells are capable of stimulating the immune system to produce highly specific and potent cellular responses against target protein antigens with little toxicity. Data from animal models suggest that Tarmogens? (yeast-based immunotherapeutics) can elicit protective immunity against xenografted and chemically induced tumours. This concept is now being tested in a Phase I trial in patients with colorectal, pancreatic and non-small cell lung cancers.     

A new decalin derivative from red yeast rice

A new decalin derivative, monascusic acid A (1), together with a new natural product (2), was isolated from the ethanol extract of red yeast rice. Their structures were elucidated by spectroscopic methods.     

Mechanism for Aar2p function as a U5 snRNP assembly factor

Little is known about how particle-specific proteins are assembled on spliceosomal small nuclear ribonucleoproteins (snRNPs). Brr2p is a U5 snRNP-specific RNA helicase required for spliceosome catalytic activation and disassembly. In yeast, the Aar2 protein is part of a cytoplasmic precursor U5 snRNP that lacks Brr2p and is replaced by Brr2p in the nucleus. Here we show that Aar2p and Brr2p bind to different domains in the C-terminal region of Prp8p; Aar2p interacts with the RNaseH domain, whereas Brr2p interacts with the Jab1/MPN domain. These domains are connected by a long, flexible linker, but the Aar2p–RNaseH complex sequesters the Jab1/MPN domain, thereby preventing binding by Brr2p. Aar2p is phosphorylated in vivo, and a phospho-mimetic S253E mutation in Aar2p leads to disruption of the Aar2p–Prp8p complex in favor of the Brr2p–Prp8p complex. We propose a model in which Aar2p acts as a phosphorylation-controlled U5 snRNP assembly factor that regulates the incorporation of the particle-specific Brr2p. The purpose of this regulation may be to safeguard against nonspecific RNA binding to Prp8p and/or premature activation of Brr2p activity.     

Minishelterins separate telomere length regulation and end protection in fission yeast

The conserved shelterin complex is critical for chromosome capping and maintaining telomere length homeostasis. In fission yeast, shelterin is comprised of five proteins. Taz1, Rap1, and Poz1 function as negative regulators of telomere elongation, whereas Pot1 and Tpz1 are critical for end capping and telomerase recruitment. How the five proteins work together to safeguard chromosome ends and promote telomere length homeostasis is a matter of great interest. Using a combination of deletions, fusions, and tethers, we define key elements of shelterin important for telomere length regulation. Surprisingly, deletion of the entire Rap1 and Poz1 proteins does not impair telomere length regulation as long as a static bridge is provided between Taz1 and Tpz1. Cells harboring minishelterin display wild-type telomere length and intact subtelomeric silencing. However, protection against end fusions in G1 is compromised in the absence of Rap1. Our data reveal a remarkable plasticity in shelterin architecture and separate functions in length regulation and end protection.     

Cellular and Subcellular Effects of Very Heavy Ions

Summary

The biological effects of irradiation with ions of masses larger than 40 and energies up to 20 MeV per atomic mass unit are reviewed. The objects are viruses, bacterial spores, yeast and mammalian cells. Experimental parameters include loss of colony forming ability, induction of mutants, chromosomal aberrations, cell cycle progression, inhibition of biochemical activities and the formation of strand breaks. Some of the pertinent physical questions–e.g. track structure–are also discussed. It is shown that with very heavy ions the biological effectiveness is no longer unambiguously related to a single parameter like l.e.t. or Z*²/β² but depends strongly on ion energy. This points to the importance of far-reaching δ-electrons. The analysis indicates also that even with very high l.e.t., cells are not killed by the passage of a single particle through their nucleus. Possible implications of the findings for fundamental radiation biology are outlined.     

Models of germ cell development and their application for toxicity studies

Germ cells are unique in their ability to transfer genetic information and traits from generation to generation. As such, the proper development of germ cells and the integrity of their genome are paramount to the health of organisms and the survival of species. Germ cells are also exquisitely sensitive to environmental influences although the testing of germ cell toxicity, especially in females, has proven particularly challenging. In this review, we first describe the remarkable odyssey of germ cells in mammals, with an emphasis on the female germline, from their initial specification early during embryogenesis to the generation of mature gametes in adults. We also describe the current methods used in germ cell toxicity testing and their limitations in examining the complex features of mammalian germ cell development. To bypass these challenges, we propose the use of alternative model systems such as Saccharomyces cerevisiae, Drosophila melanogaster, Caenorhabditis elegans, and in vitro germ cell methods that have distinct advantages over traditional toxicity models. We discuss the benefits and limitations of each approach, their application to germ cell toxicity studies, and the need for computational approaches to maximize the usefulness of these models. Together, the inclusion of these alternative germ cell toxicity models will be invaluable for the examination of stages not easily accessible in mammals as well as the large scale, high‐throughput investigation of germ cell toxicity. Environ. Mol. Mutagen. 56:637–649, 2015. © 2015 Wiley Periodicals, Inc.     

High levels of melatonin generated during the brewing process

Beer is a beverage consumed worldwide. It is produced from cereals (barley or wheat) and contains a wide array of bioactive phytochemicals and nutraceutical compounds. Specifically, high melatonin concentrations have been found in beer. Beers with high alcohol content are those that present the greatest concentrations of melatonin and vice versa. In this study, gel filtration chromatography and ELISA were combined for melatonin determination. We brewed beer to determine, for the first time, the beer production steps in which melatonin appears. We conclude that the barley, which is malted and ground in the early process, and the yeast, during the second fermentation, are the largest contributors to the enrichment of the beer with melatonin.     

Nutritive value,antioxidant activity and phenolic compounds profile of brewer’s spent yeast extract

Spent yeast is the second major by-product from brewing. Mechanical disruption of yeast cell wall can be used to obtain β-glucan rich ingredients and separate inner yeast content, both with potential applications as food and nutraceutical ingredients. In this work, the nutritional composition, including minerals and B-complex vitamins, together with the antioxidant activity and phenolic compounds profile of yeast extract, prepared by mechanic disruption of brewer’s spent yeast and removal of yeast cell wall, was investigated. The lyophilised yeast extract presented 64% of proteins with high proportion of essential amino acids and 4% of RNA; macrominerals (Na, K, Ca, Mg), trace elements such as Zn (11.9 mg/100 g dw), Fe (1.76 mg/100 g dw), and Mn (0.564 mg/100 g dw), and vitamins B3 (77.2 mg/100 mg dw), B6 (55.1 mg/100 g dw) and B9 (3.01 mg/100 g dw). Two phenolic compounds were quantified as free forms, gallic acid and (±) catechin, whereas other bounded phenolic compounds were also quantified. The nutrients content, antioxidant properties and phenolic composition of the lyophilised brewer’s spent yeast extract indicates that it can be an interesting food or nutraceutical ingredient. Thus, its recovery will be beneficial in terms of sustainability and environmental impact.