Altered expression of the retinoblastoma gene product in human sarcomas

BACKGROUND. The retinoblastoma-susceptibility (Rb) gene is a prototype tumor-suppressor gene originally isolated from patients with heritable retinoblastoma. This gene encodes a nuclear phosphoprotein whose expression is altered in several types of human tumors. METHODS. We studied the expression of the Rb protein in 44 primary and 12 metastatic high-grade human sarcomas by means of immunohistochemical methods and Western blotting. Computerized image analysis was used to quantify the level of Rb gene product in individual tumor cells. The expression of the Rb gene was then correlated with clinical outcome in the patients with primary tumors. RESULTS. Of the 44 patients with primary sarcomas, 13 (30 percent) had tumors with normal, homogeneous expression of the Rb protein in essentially all tumor cells. Thirty-one patients with primary tumors (70 percent) had altered Rb expression; in 18 (40 percent) the Rb protein was heterogeneously expressed, and in 13 (30 percent) it was detected in fewer than 20 percent of the tumor cells. All 12 of the patients with metastatic sarcomas had altered expression of the Rb protein. When the findings in the patients with primary tumors were correlated with clinical outcome, survival was found to be significantly increased in the patients whose tumors had homogeneous Rb expression, as compared with those with either heterogeneous expression (P = 0.026) or no expression (P = 0.012). CONCLUSIONS. Tumors in which the expression of Rb gene product was decreased were more aggressive than tumors in which this protein was expressed by nearly all cells. The Rb gene product may be an important prognostic variable in patients with these tumors.     

Four new adenosine deaminase mutations,altering a zinc-binding histidine,two conserved alanines,and a 5′ splice site

Three new missense mutations (H15D, A83D, and A179D) and a new splicing defect (573 + 1G→A) in the 5′ splice site of intron 5 were among six mutant adenosine deaminase (ADA) alleles found in three unrelated patients with severe combined immunodeficiency disease, the most common phenotype associated with ADA deficiency. When expressed in vitro, the H15D, A83D, and A179D proteins lacked detectable ADA activity. The splicing defect caused skipping of exon 5, resulting in premature termination of translation and a reduced level of mRNA. H15D is the first naturally occurring mutation of a residue that coordinates directly with the enzyme-associated zinc ion. Molecular modeling based on the atomic coordinates of murine ADA suggests that the D15 mutation would create a cavity or gap between the zinc ion and the side chain carboxylate of D15. This could alter the ability of zinc to activate a water molecule postulated to play a role in the catalytic mechanism. A83 and A179 are not directly involved in the active site, but are conserved residues located respectively in a helix 4 and β strand 4 of the α/β barrel. Replacement of these small hydrophobic Ala residues with the charged, more bulky Asp side chain may distort ADA structure and affect enzyme stability or folding.© 1995 wiley-Liss, Inc.     

The skin,tongue, and brain as favorable organs for hog cholera diagnosis by immunofluorescence

Summary Hog cholera virus antigens were found densely distributed in skin and tongue of pigs experimentally infected with hog cholera virus. The finding described here warrants the usage of ear biopsies for hog cholera diagnosis on a herd basis.     

琥珀酸美托洛尔HPMC骨架片释放影响因素研究

以羟丙基甲基纤维素（HPMC）为骨架材料，乙基纤维素（EC）为阻滞剂，采用湿颗粒压片法制备琥珀酸美托洛尔亲水凝胶骨架片，考察HPMC用量、HPMC黏度、EC用量、制备方法、压片压力、释放介质及转速对琥珀酸美托洛尔（MS）骨架片体外释药的影响。结果表明，MS骨架片体外释药符合Higuchi方程，药物释放机制是骨架溶蚀和药物扩散的综合效应；HPMC用量与黏度、阻滞剂用量、制备方法、压片压力对释放速率均有显著性影响；释放介质的pH值及转速对释放速率无显著性影响。     

Treatment of acute post-surgical infection of joint arthroplasty

The best antibiotic regimen for acute prosthetic joint infection, treated without removal of the implant, has not been well-defined. This study describes the use of a protocol based on oral rifampicin combinations to treat 47 cases that were followed prospectively for a 2-year period. The regimen used most commonly was levofloxacin 500 mg/24 h plus rifampicin 600 mg/24 h for a mean duration of 2.7 ± 1 months. The cure rate was 76.9%, and the only independent risk-factor associated with treatment failure was infection caused by methicillin-resistant Staphylococcus aureus or Enterococcus spp. (OR 17.6, p 0.003). Overall, the results suggested that use of oral antibiotics, including rifampicin, for 2–3 months was a good treatment option.     

Identification of immune genes in grass carp Ctenopharyngodon idella in response to infection of the parasitic copepod Sinergasilus major

The parasitic copepod Sinergasilus major is an important pathogen of grass carp Ctenopharyngodon idella. To understand the immune response of grass carp to the copepod infection, suppression subtractive hybridization method was employed to characterize genes up-regulation during the copepod infection in liver and gills of the fish. One hundred and twenty-two dot blot positive clones from infected subtracted library were sequenced. Searching available databases by using these nucleotide sequences revealed that 23 genes are immune-related, including known acute-phase reactants, and four novel genes encoding proteins such as source of immunodominant MHC-associated peptides (SIMP), TNF receptor-associated factor 2 binding protein (T2BP), poliovirus receptor-related protein 1 precursor, glycoprotein A repetitions predominant (GARP). The differential expression of seven immune genes, i.e. GARP, alpha-2-macroglobulin, MHC class I, C3, SIMP, T2BP, transferrin, as a result of infection was further confirmed by RT-PCR, with the up-regulation of alpha-2-macroglobulin, MHC class I, C3, SIMP and T2BP in the liver of infected fish, and down-regulation of SIMP in the gills of infected fish. The present study provides foundation for understanding grass carp immune response and candidate genes for further analysis.     

Acute stress reduces intraparenchymal lung natural killer cells via beta-adrenergic stimulation

There are lines of evidence that natural killer (NK) cells are sensitive to physical and psychological stress. Alterations in the immune system including NK cells are known to differ among tissues and organs. The effect of stress on the lung immune system, however, has not been well documented in spite of the fact that the lungs always confront viral or bacterial attacks as well as tumour cell metastasis. In this study, we intended to investigate the effect of restraint stress on lung lymphocytes including NK cells. C57BL/6 mice were exposed to 2 h restraint stress. The concentration of plasma epinephrine significantly rose immediately after the release from restraint as compared to home-cage control mice. Flow cytometric analysis revealed that the numbers of most lymphocyte subsets including NK cells were decreased in the lungs and blood but not in the spleen, immediately after restraint stress. Immunohistochemical examination revealed that the number of NK cells was decreased in the intraparenchymal region of the lungs, while the number of alveolar macrophages did not change. The decrease in the number of NK cells in the lungs and blood was reversed by the administration of propranolol, a nonselective beta adrenergic antagonist. Taken together, our findings suggest that acute stress reduces the number of intraparenchymal lung NK cells via activation of beta adrenergic receptors.     

Effect of illumination of nitrate and phosphate removal by coimmobilized Chlorella pyrenoidosa and activated sludge

Chlorella pyrenoidosa and activated sludge were co-immobilized with simplifying modified PVA-sulfate method. Effects of light intensity and light:dark ratio on the growth of co-immobilized algae cells and removal of nitrate and phosphate were studied. The results indicate that the growth rate of co-immobilized algae cells reduces when light intensity is decreased from 4000 Lux to 1000 Lux, while optimal light:dark ratio for algal growth is 16:8. The influence of illumination on nitrate removal is so weak that the removal percentage can reach 90 approximately 100% within 12 approximately 24 h during the experimental periods in spite of changing illumination conditions. On the other hand, phosphate removal efficiency reduces when light intensity or light:dark ratio is decreased. The highest phosphate removal percentage is 99.6% under the circumstances of 4000 Lux and full-time illumination in our experiment, while the average phosphate removal is about 78%. The change of pH value in water samples is also observed. When water sample is treated by the co-immobilized system, pH value increases in light and decreases in dark. Microorganisms' physiological action is considered as the main mechanism that leads to the change of pH value.     

基质金属蛋白酶1与冠状动脉粥样硬化斑块破裂的关系

目的 探讨冠状动脉粥样硬化斑块破裂与基质金属蛋白酶１（ＭＭＰ－１）的关系,以及不稳定斑块中ＭＭＰ－１的来源。方法 收集２０例死于急性心肌梗死、１０例有不稳定心绞痛史,以及１２例有稳定心绞痛史的尸体解剖病例共４２例,从冠状动脉各分支取材,常规病理检查、部分节段行ＭＭＰ－１、平滑肌肌动蛋白、ＣＤ６８、ＣＤ４５ＲＯ和ＣＤ２０洒色。结果 在急性心肌梗死及不稳定心绞痛病例中,均见有斑块破裂伴血栓形成,而在稳