The characteristics of the viruses involved in avian respiratory diseases and some bird-man epidemiological correlations

The structural gene for translation initiation factor IF2 from Thermus thermophilus was identified on the basis of the N-terminal amino acid sequence of intact T thermophilus IF2 and an internal 25 kDa IF2 fragment. A total of 5135 bp was cloned and sequenced, comprising the open reading frames for p15A, NusA, p10A, IF2, p10B and SecD, which may form an operon. There are pronounced similarities between the operon arrangement and primary sequence of the T thermophilus genes and proteins, respectively, and their counterparts from other organisms. The T thermophilus infB gene was expressed to a high level in E coli. Four hundred milligrams of homogenous T thermophilus IF2 were prepared from 60 g of overproducing cells.     

Cell-free apoptosis in Xenopus egg extracts: inhibition by Bcl-2 and requirement for an organelle fraction enriched in mitochondria

Apoptotic cell death involves a ritual series of morphological changes, presumably reflecting a conserved molecular pathway. We now report that the nuclear events typical of apoptosis can be reproduced in "apoptotic" Xenopus egg extracts. In this cell-free system, nuclear assembly and protein import are initially normal; after 2-4 hr, however, a process of nuclear destruction ensues involving chromatin condensation and the shrinkage and fragmentation of the nuclei. This apoptotic process, which also occurs in nuclei added exogenously, is blocked by the addition of baculovirus-expressed Bcl-2 protein. To block the disintegration of nuclei that are added later, Bcl-2 must be present during this latent period. "Apoptosis" in these extracts requires a dense organelle fraction enriched in mitochondria. The cell-free system described here provides a novel tool for understanding intracellular events in apoptosis and the inhibitory function of Bcl-2.     

A candidate recombination modifier gene for Zea mays L

Maize meiotic mutant desynaptic (dy) was tested as a candidate recombination modifier gene because its effect is manifested in prophase I. Recombination rates for desynaptic (dy) and its wild type were compared in two ways: (1) segregation analysis using six linked molecular markers on chromosome 1L and (2) cytogenetic analysis using fluorescence in situ hybridization (FISH)-aided meiotic configurations observed in metaphase I. Chromosome 1L map lengths among the six linked markers were 45-63 cM for five F2 dy/dy plants, significantly lower than the wild-type F2 map distance of 72 cM. Chromosomes 2 and 6 were marked with rDNA FISH probes, and their map lengths were estimated from FISH-adorned meiotic configurations using the expectation-maximization algorithm. Chiasma frequencies for dy/dy plants were significantly reduced for both arms of chromosome 2, for chromosome arm 6L, and for eight unidentified chromosomes. There was a notable exception for the nucleolus-organizing region-bearing arm chromosome arm 6S, where dy increased chiasma frequency. Maize meiotic mutant desynaptic is a recombination modifier gene based on cytogenetic and segregation analyses.     

Requirement for multiple lymphocyte subsets in protection by a live attenuated vaccine against retroviral infection

STUDY DESIGN: A case report and literature review of thoracic hyperkyphosis deformity secondary to glucocorticoid-induced osteoporosis in Cushing's disease. OBJECTIVES: To identify the pathophysiology of glucocorticoid-induced osteoporosis and to outline the diagnosis and treatment options for a patient with severe spinal deformity secondary to unrecognized excess glucocorticoid activity. SUMMARY OF BACKGROUND DATA: Glucocorticoid-induced osteoporosis is seen in patients exposed to supraphysiologic levels of endogenous or exogenously administered glucocorticoids. In these patients, glucocorticoids act to suppress bone formation and increase bone resorption by indirect and direct effects. These patients have a high prevalence of trabecular bone loss, resulting in much higher rates of vertebral body collapse and pathologic fracture and thus causing an increased propensity toward kyphotic spinal malalignment. METHODS: The literature was reviewed and case reports studied. This case report highlights the pathophysiology of the disease process that caused the spinal deformity and the surgical intervention used to correct the kyphotic deformity after the metabolic problem was resolved. RESULTS: This patient has responded well to treatment and surgical intervention to correct a thoracic hyperkyphotic deformity without complication. CONCLUSIONS: Unrecognized endogenous production of glucocorticoids in Cushing's disease should be considered in young adult patients with progressive osteoporotic spinal deformities.     

无色透明新型光纤油膏的研制开发

光纤油膏是光缆中必不可少的新型防水材料，光纤油膏直接与光纤接触，质量指标要求很高．在国内原料无法满足生产高质量的光纤油膏的前提下，用自制的主要原料高吸油性聚合物、抗下垂剂进一步与石油烃、有机增稠剂、无机填料充分混合均匀，制成了析氢值低、油分离小、锥入度大、高低温性能好、指标达到进口指标的光纤油膏．