A cell-free model of the encephalomyocarditis virus-induced inhibition of host cell protein synthesis.

When preincubated extracts from Krebs-II cells were supplemented with total poly(A)-containing RNA isolated from encephalomyocarditis virus-infected Krebs-II cells, two phenomena characteristic of EMC virus infection of these cells in vivo were observed: (i) preferential translation of viral rather than cellular, mRNA, and (ii) a general inhibition of protein synthesis, relative to the synthesis in samples where the poly(A)-containing RNA from uninfected cells served as the template. The first effect could not be explained by an irreversible functional inactivation of cellular templates and seemed to result from a direct interference of viral RNA with the translation of cellular mRNA. The second effect was due primarily to the presence of double-stranded RNA.     

Cross-reactive antigens and immunity to diseases caused by encapsulated bacteria.

Antigenic structures may be shared among naturally occurring polymers, including proteins and polysaccharides. Proteins are polymers of amino acids. Cross-reactions between proteins are due to similarities in their overall shape rather than their individual amino acid components. Cross-reactions have been demonstrated among proteins with similar evolutionary development and structure, such as serum albumins or immunoglobulins. Polysaccharides are polymers of monosaccharides. In contrast to proteins, antigenic specificities may be conferred by mono-, di-, and trisaccharides. Since there are about 150 known naturally occurring monosaccharides, it is not unexpected that cross-reactions are demonstrable between polysaccharides from widely divergent sources.     

Study of the HLA system in Burkitt's lymphoma

Seventy-eight patients with Burkitt's lymphoma and seventy controls from Ghana were typed for HLA-A, B, C and DR antigens, to determine whether there is an association between the HLA system and Burkitt's lymphoma. Increased relative risk was observed in Burkitt's lymphoma patients with DR7, HLA-A1 and B12 (BW44).     

Immunologic mechanisms in hypersensitivity pneumonitis: I. Evidence for cell-mediated immunity and complement fixation in pigeon breeders' disease

Immunologic studies were performed on 5 patients with pigeon breeders' disease. Intradermal injection of pigeon serum produced an immediate wheal-and-flare reaction within 15 minutes and a secondary Arthus-type reaction within 4 to 8 hours. Immunofluorescent studies of the secondary reaction site showed IgG, C3, and C4 in 2 patients. Patients' sera produced multiple precipitin bands with pigeon serum when reacted by double diffusion in gel. IgG antibody isolated from each of the patients' serum formed precipitating immune complexes that fixed large amounts of complement (C4) when added to fresh human serum. Peripheral blood lymphocytes from 4 of the 5 patients produced macrophage migration inhibitory factor (MIF) when challenged with dilute pigeon serum. These studies are the first to show complement fixing antibodies and macrophage MIF production by lymphocytes from patients with hypersensitivity lung disease and suggest that both humoral and cellular immunity may be important in the pathogenesis of these disorders.     

Cell-mediated immunity in leprosy and transfer of delayed hypersensitivity reactions

Eighty-nine patients with leprosy, 65 classified as lepromatous and 24 as tuberculoid, were examined in this study. Skin test responses to protein antigens and dinitrochlorobenzene (DNCB) were depressed in lepromatous patients compared to controls. Tuberculoid patients did not exhibit a significant depression to microbial antigens, but they showed a definite depression in the ability to be sensitized with DNCB. The transfer of delayed hypersensitivity reactions to tuberculin, trichophytin, and lepromin (Fernandez and Mitsuda reactions) was accomplished in lepromatous and indeterminate leprosy patients using viable lymphocytes from donors presenting positive reactions to these antigens. The lepromin reaction was also transferred to patients with South American blastomycosis and cutaneous leishmaniasis. The positive reactions of adoptive immunity were confirmed by histologic examination of skin biopsies.     

Effect of histamine and methacholine on nasal airway resistance in atopic and nonatopic subjects: Comparison with bronchial challenge and skin test responses

Serial nasal, intracutaneous, or bronchial challenges were carried out with solutions containing 2- or 3-fold increments in histamine (H) or methacholine (Meth) concentration until nasal airway resistance (NAR) increased by more than 100%, a large intracutaneous reaction was elicited, or FEV₁ decreased by 20% or more. Thirty nonatopic and 48 asymptomatic atopic subjects were studied, the latter group divided into rhinitic patients with and without asthma. Several types of data analysis demonstrated there was no significant difference in the nasal or cutaneous effects of H or Meth between the atopic and nonatopic groups. Comparable results were obtained in a subgroup of 39 subjects (13 normal, 13 atopic, and 13 atopic with asthma) who underwent all six test sequences (i.e., nasal, cutaneous, and bronchial with both drugs). As expected, the asthmatics showed significantly increased bronchial reactivity to both agents. In comparison with Meth, H had a much greater effect on the nasal mucosa and skin than on the bronchi. It is concluded that, contrary to bronchial responses, but in accord with cutaneous reactivity, the nasal responses of nonatopic subjects, atopic persons with allergic rhinitis alone, and subjects with both allergic rhinitis and asthma show no intergroup differences on testing with H or Meth.     

Isolation and characterization of entomopox virions from virus-containing inclusions of Amsacta moorei (Lepidoptera: Arctiidae)

Preparations of Amsacta moorei entomopox virions were obtained from virus-containing inclusions (VCI) by using a carbonate-thioglycolate solution (pH 10.7–11.5). The virions possessed a uniform coat (“halo”) surrounding the viral envelope and exhibited an RNA polymerase activity. The “halo” could be removed by prolonged exposure to the carbonate-thioglycolate solution. Virions obtained by this treatment, however, possessed low infectivity and no detectable RNA polymerase activity. Removal of the “halo” by trypsin resulted in virions which possessed RNA polymerase activity and relatively high infectivity.Preparations of particles with and without the “halo” were similar in percent DNA, protein per OD₂₆₀, number of particles per OD₂₆₀, and RNA polymerase activity. Particles without the “halo,” however, were less dense (1.262 g/cm³) in CsCl than those with the “halo” (1.282 g/cm³) and 15–45 times more infective.Parallel studies of “nonhaloed” Amsacta virions (trypsin-treated) and vaccinia virions showed that both viruses contained similar amounts of protein per OD₂₆₀, but Amsacta virions contained only 36% of the DNA found in vaccinia.     

徐州地区334例早产儿临床分析

目的探讨我院2006年334例早产儿,分析发生的危险因素,以总结提高产科早产预防、医疗水平,并提供研究参考。方法早产组334例与同期分娩的足月对照组334例分析比较,早产的临床相关因素及对围产儿的影响。结果胎膜早破,妊娠高血压综合征,前置胎盘,臀位,多胎妊娠是早产的重要因素。早产使新生儿窒息,围生儿死亡,低体重儿增加。结论早产使围产儿窒息和死亡率增加。加强早产预测可望降低早产的发生,提高围生医学质量。     

去甲肾上腺素诱导严重烧伤大鼠脑组织VEGF表达的实验研究

目的：观察去甲肾上腺素（NE）诱导严重烧 伤后24h大鼠脑组织血管内皮细胞生长因子(VEGF)的表达变化。方法:(1 )采用40%全身总体表面积（TBSA）Ⅲ°烧伤大鼠模型，用干、湿重法检测NE刺激烧伤24h大 鼠脑组织含水量；(2)用高效液相色谱法，检测烧伤大鼠脑组织去甲肾上腺素活性水平的变 化;(3) 用免疫蛋白印迹法（Western blotting）检测NE诱导脑组织VEGF蛋白表达变化。 结果：(1) 烧伤大鼠和NE刺激后的烧伤大鼠脑组织水肿明显；(2)烧伤后2 4 h大鼠脑组织NE活性增加，而NE刺激后的烧伤大鼠，脑组织NE的活性增加显著;(3) NE刺 激剂量增大时，脑组织VEGF的蛋白表达逐渐增加，烧伤后VEGF的蛋白表达增加明显，随NE刺 激剂量增大，烧伤后VEGF的蛋白表达明显增强。结论:NE可诱导严重烧 伤大鼠脑组织VEGF的蛋白表达，提示烧伤后NE水平增高是脑水肿形成的一个重要因素。