Influence of increasing breast meat yield on muscle histology and meat quality in the chicken

The histological characteristics, ie, myofibre types and cross-sectional areas (CSA), of pectoralis major and sartorius muscles of 20 male chickens from two lines (ten birds from each line) divergently selected for breast meat yield were compared. Moreover, some quality parameters (ie, drip loss, ultimate pH value and meat colour) of the breast muscle were recorded. The animals from both lines displayed identical pectoralis major myofibre types and CSA. A slight difference in typology, but not in myofibre CSA, was observed in the sartorius muscle: animals with the highest breast meat yield tended to have a more pronounced glycolytic character. No significant difference was observed in the quality of breast meat (pH, colour and drip loss).     

Prediction of the lithium ratio in man by means of an in vitro test

The movement of the lithium ion (Li+) across the membrane of intact erythrocytes incubated in vitro was assessed under two different experimental conditions in which such transfer occurred primarily due to the activity of a lithium-sodium countertransport system. The 13 subjects on whom the in vitro procedures were done subsequently received lithium carbonate for 14 to 56 days, and the extent of accumulation of Li+ by erythrocytes in vivo was measured. While both in vitro procedures yielded data that correlated with the extent of accumulation of Li+ by erythrocytes in vivo, a system measuring the efflux of Li+ from Li+-loaded cells produced a much higher correlation (0.976). The magnitude of this correlation suggests that this in vitro system can be used for further investigations into the relevance of the erythrocyte accumulation of Li+ to the pathogenesis and treatment of affective disorders.     

The biological role of carnosine in excitable tissues

We provide a general framework for the development of model-free methods for the linkage analysis of multivariate phenotypic data. It is possible within this framework to test both for linkage of a set of phenotypes to one or more markers and for the presence of structural relations among the phenotypes themselves. This report presents the general model, paying special attention to the assumptions that enter its formulation, and outlines the estimation procedures that may be used.     

Estimating CE ratios under second-order uncertainty: the mean ratio versus the ratio of means

This study is based on data for individuals with a history of stroke taken from the NIA-sponsored Longitudinal Study of Aging (LSOA), 1984-1990. It provides information on the factors predicting survival and changes in disability and activity limitations in this cohort with stroke or cerebrovascular accident over the period of two years, 1984 to 1986. The results indicate that individuals who were less than 80 years old had higher chances of survival and were likely to show reduced activity limitations and disabilities. It was also observed that the individuals who were in excellent health were more likely to survive despite a history of stroke. Individuals with severe activity limitations had a very low incidence of survival over the two-year period. Further, the results of this study support the contention that the increased use of health care resources in the form of visits to physicians, hospitals, and nursing homes results in improved survival and lower disability and activity limitations among the elderly.     

Electron microscopic detection of glycoconjugates in the chicken lens

The cytochemical localization of glycoconjugates in the 14-day old embryonic chick lens was analysed by lectin-gold labelling. Con A/HRP gold particles, specific for D-mannose labelled the interior of the rough endoplasmic reticulum, membranes of the Golgi complex, secretory vesicles and the plasma membranes of the lens epithelial cell. The lens capsule was heavily labelled. Lens fiber cell membranes were also labelled. In contrast LFA, specific for neuraminic acid, did not bind to the endoplasmic reticulum or nuclear membrane. Labelling of the Golgi complex, secretory vesicles and capsule was observed. The plasma membranes of epithelial and fiber cells were extensively labelled, and probably reflects the presence of glycolipids such as gangliosides.     

钢铁企业吨材综合能耗与材比系数的探讨

钢铁企业通常用吨钢综合能耗与钢比系数来衡量企业整体用能效率,它们在应用中都有一定的局限性.从主生产工序外销产品所含铁素量角度定义了当量材,进而定义吨材综合能耗与材比系数并讨论了它们的适用性.     

The power of linkage detection by the transmission/disequilibrium tests

Despite growing interest in the use of transmission/disequilibrium test (TDT)-type analysis in association studies, there has been surprisingly scant attention paid to the issues as to what factors affect the power of the TDT for linkage detection. We demonstrate in this paper that the power is a function of several genetic parameters including the recombination fraction, penetrance, the age of mutant disease allele, marker allele frequency, recurrent mutation rates at marker and/or disease locus, and initial linkage disequilibrium. In general, TDT has greater power to detect linkage for a 'recessive'-type model than for a 'dominant'-type model. Its power also is higher when there is greater differential in marker allele frequency between disease and normal chromosomes. And since the presence of marker mutation and/or recurrent mutation at the disease locus, or the age of disease mutation, or the initial incomplete linkage disequilibrium, all hasten the process to reach linkage equilibrium, all of them can affect the power of TDT to detect linkage. The effect of marker mutation rate or the mutation rate at the disease locus can be minimal if mutation rates are low. The results on the impact of recombination fraction and of age of mutation on the power of TDT in linkage detection seem to be disheartening for gene mappers of complex diseases: for a disease with small genetic influence, a vastly large sample size is needed to detect the linkage, if the marker is not very close to the disease locus. This is particularly true if the disease is 'old'.     

Inhibition of the growth of transformed and neoplastic cells by the dipeptide carnosine

Human diploid fibroblasts growth normally in medium containing physiological concentrations of the naturally occurring dipeptide carnosine (beta-alanyl-L-histidine). These concentrations are cytotoxic to transformed and neoplastic cells lines in modified Eagle medium (MEM), whereas these cells grow vigorously in Dulbecco's modified Eagle medium (DMEM) containing carnosine. This difference is due to the presence of 1 mM sodium pyruvate in DMEM. Seven human cell lines and two rodent cell lines were tested and all are strongly inhibited by carnosine in the absence of pyruvate. Experiments with HeLa cells show that anserine is similar to carnosine, but D-carnosine and homocarnosine are without effect. Also, the non-essential amino acids alanine and glutamic acid contribute to the effect of pyruvate in preventing carnosine toxicity, and oxaloacetate and alpha-ketoglutarate can substitute for pyruvate. We have used mixtures of normal MRC-5 fibroblasts and HeLa cells to demonstrate that 20 mM carnosine can selectively eliminate the tumour cells. This has obvious implications which might be exploited in in vivo and in vitro studies. Carnosine is known to react strongly with aldehyde and keto groups of sugars by Amadori reaction, and we propose that it depletes certain glycolysis intermediates. It is well known that tumour cells are more dependent on glycolysis than normal cells. A reduction of glycolysis intermediates by carnosine may deplete their energy supply, but this effect is totally reversed by pyruvate.     

The C/D ratio in normal newborns

Attempts were made to identify Mycobacterium avium and Mycobacterium intracellulare in the M. avium-intracellulare complex (MAC) isolated in the Tohoku district of Japan by using DNA probes (Gen-Probe; Rapid Diagnostic System) which are specific for M. avium, M. intracellulare and M. tuberculosis complex, respectively. In the Tohoku district, the ratio of M. avium isolates (80%) exceeded that of M. intracellulare isolates. It was thus shown that, in the Tohoku district where no data concerning the ratio of M. avium to M. intracellulare isolates had been available, the ratio of M. avium by far exceeded that of M. intracellulare.     

Method of soy protein detection in sausage products

The method of soya protein extraction from sausage products was developed for soya protein content determination by isoelectric focusing. It was showed most optimal extraction agent was 3% solution of Triton X100.     

Quantification of Bordetella pertussis in clinical samples by colorimetric detection of competitive PCR products

Quantification of microorganisms is an important part of the normal diagnostic work of a clinical microbiology laboratory. Traditionally the diagnosis of pertussis is subject to a yes or no approach with no quantitative dimension. This can, however, be of interest as a factor when judging the risk of a patient spreading the bacterium and as a research tool. The aim of the present study was to develop a PCR-based quantitative assay for Bordetella pertussis DNA in clinical nasopharyngeal aspirates by combining a quantitative PCR with a colorimetric detection principle, DIANA (detection of immobilised amplified nucleic acid). A competitor to the PCR target sequence in IS-481, containing a lac-operator, was constructed and calibrated, and a test protocol prepared. A total of 46 clinical nasopharyngeal aspirates, previously diagnosed using a standard nested PCR assay and quantified by culture, were analysed by the quantitative PCR. The method showed acceptable precision and accuracy considering that it estimates the total number of bacterial genomes while culture detects viable bacteria. Recognised advantages were the simple colorimetric detection, the inborn indication of a working PCR assay, and the possibility of obtaining results even when partial inhibition of the PCR assay was seen. In addition, the quantitative PCR result can be obtained within one day compared to 3-10 days for culture. The present results and the qualities of the quantitative PCR suggest that this assay will be a useful complement in routine diagnostics and in research.     

图像处理技术在耐火制品热震性检测中的应用

抗热震性能是表征耐火材料抵抗温度急剧变化而不破坏能力的1个实用参数.利用数字图像处理技术对耐火浇注料预制件在热震实验过程中产生的裂纹密度进行评定,结果表明: 与传统方法相比,数字图像技术能更好、更准确地确定耐火材料的热震性能,提高工作效率.