Adenovirus type 12 tumor antigen. II. Immunoprecipitation of protein kinase from infected and transformed cells by antisera to T antigen and some normal rat sera.

Protein kinase was found to be precipitated from adenovirus type 12 (Ad12)-infected KB cells and Ad12-transformed hamster cells by sera of tumor-bearing hamsters and rats: Immunoprecipitates obtained with T antigen reactive sera catalyzed transfer of ³²P from [γ-³²P]ATP to the γ-chain of IgG. Analogous products of control cells were without significant activity. Control hamster sera precipitated no protein kinase from infected and transformed cells. Some control rat sera (syngeneic with immune sera), however, were found to precipitate protein kinase from infected and transformed cells; particularly active in this respect were sera of female breeder rats. When partially purified, highly immunoreactive T antigen preparations from transformed cells were used as a source of enzymatic activity, protein kinase was detected only in precipitates obtained with immune sera.     

No association between the Pro197Leu polymorphism in the glutathione peroxidase (GPX1) gene and schizophrenia

OBJECTIVE: Oxidative stress such as free radical-mediated neuronal dysfunction may be involved in the pathophysiology of schizophrenia. The human glutathione peroxidase (GPX1) is a selenium-dependent enzyme, which plays an important role in the detoxification of free radicals. We therefore hypothesized that the GPX1 gene, which is located on chromosome 3p21.3, may be involved in the pathophysiology of schizophrenia. The aim of this study is to examine whether a potentially functional polymorphism, a proline (Pro) to leucine (Leu) substitution at codon 197 (Pro197Leu) of the human GPX1 gene, is associated with susceptibility to schizophrenia. METHODS: We genotyped the Pro197Leu polymorphism in a total of 113 nuclear families that had a proband with schizophrenia. Genetic association was tested using the transmission disequilibrium test (TDT), the sib transmission disequilibrium test (STDT), and the family-based association test (FBAT). RESULTS: The minor allele (Leu) frequency was calculated to be 0.282. We could not find significant transmission disequilibrium of the alleles for the Pro197Leu polymorphism in the GPX1 gene in association with the presence of schizophrenia in our family sample (TDT, chi2=0.03, degrees of freedom=1, P=0.86; combined TDT-STDT, Z'=-0.052, P=0.47; FBAT, Z=0.000, P=1.000). CONCLUSION: The results of this study suggest that the GPX1 polymorphism is unlikely to be associated with susceptibility to schizophrenia.     

Legionella gormanii sp. nov

A new species of Legionella was isolated from soil collected from a creek bank. The name Legionella gormanii sp. nov. is proposed.     

Comparative analysis of multilocus sequence typing and pulsed-field gel electrophoresis for characterizing Listeria monocytogenes strains isolated from environmental and clinical sources

One hundred seventy-five Listeria monocytogenes strains were characterized by serotyping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) based on loci in actA, betL, hlyA, gyrB, pgm, and recA. One hundred twenty-two sequence types (STs) were identified by MLST based on allelic profiles of the four housekeeping genes (betL, gyrB, pgm, and recA), and 34 and 38 alleles were identified for hlyA and actA, respectively. Several actA and hlyA alleles appeared to be predominantly associated with clinical isolates. MLST differentiated most of the L. monocytogenes strains better than did PFGE, and the discriminating ability of PFGE was better than that of serotyping. Several strains with different serotypes were found, by MLST and PFGE, to have very closely related genetic backgrounds, which suggested possible "antigen switching" among them. MLST can be a useful typing tool for differentiating L. monocytogenes strains (including strains undistinguishable by PFGE typing and serotyping), and it may be of value during investigations of food-borne outbreaks of listeriosis.     

The origin of human chromosome 2 analyzed by comparative chromosome mapping with a DNA microlibrary

Fluorescencein situ hybridization (FISH) of microlibraries established from distinct chromosome subregions can test the evolutionary conservation of chromosome bands as well as chromosomal rearrangements that occurred during primate evolution and will help to clarify phylogenetic relationships. We used a DNA library established by microdissection and microcloning from the entire long arm of human chromosome 2 for fluorescencein situ hybridization and comparative mapping of the chromosomes of human, great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus) and Old World monkeys (Macaca fuscata andCercopithecus aethiops). Inversions were found in the pericentric region of the primate chromosome 2p homologs in great apes, and the hybridization pattern demonstrates the known phylogenetically derived telomere fusion in the line that leads to human chromosome 2. The hybridization of the 2q microlibrary to chromosomes of Old World monkeys gave a different pattern from that in the gorilla and the orang-utan, but a pattern similar to that of chimpanzees. This suggests convergence of chromosomal rearrangements in different phylogenetic lines.     

Does feeding regime affect physiologic and thermal responses during exposure to 8, 20, and 27° C?

Summary When the loss of body heat is accelerated by exposure to low environmental temperatures, additional substrates must be oxidized to provide energy to sustain temperature homeostasis. Therefore, the present investigation examined the relation between feeding regime [pre-experimental carbohydrate feeding (FED) vs a fast (FAST)], during 120 min of exposure to 8, 20, and 27° C in well-nourished men. The following were examined: tissue insulation (I; °C · m² · W^–1), rectal temperature (T _re; °C), and oxygen consumption ( O₂; ml · kg^–1 · min^–1). O₂, T _re, and I revealed no significant differences between treatments (FED vs FAST) at any temperature. At 27° C, I was less (P < 0.05) than at 20 and 8° C, and decreased (P < 0.05) as exposure time increased. At 8° C, O₂was higher (P < 0.5) than at 20 or 27°C, and O₂increased as time increased (P < 0.05). T _re decreased (P < 0.05) as time increased for all conditions. Respiratory exchange ratio (R) differed (P < 0.05) between treatments (FED vs FAST), temperature (8 vs 20° C), and across time. Values for R suggests that carbohydrate accounted for 56% and 33% of caloric utilization during the FED vs FAST conditions, respectively. At 8 vs 20° C, R represented 54% vs 30% of cabohydrate utilization. Across time, R demonstrated that in both conditions (FED vs FAST) there was a decreased reliance on carbohydrate utilization for energy provision. From these data it appears that while substrate utilization differed between dietary treatment and across time this did not differentially affect O₂or T _re during protracted exposure to 8, 20, and 27° C. The higher R in the 8° C condition for both dietary treatments demonstrates that carbohydrate utilization is increased in shivering cold-exposed humans. However, the reduction in R across time suggests that fat oxidation is also involved in metabolic heat production and core temperature maintenance during shivering in the cold.     

Longitudinally orientated smooth muscle cells in rabbit arteries

Intima formation in vessels, spontaneous or experimentally induced, is generally characterized by the presence of longitudinally orientated smooth muscle cells (LSMC). During an experiment of neo-intima induction in carotid arteries in rabbits, by application of a nonconstrictive silastic cuff, a study was performed to investigate the presence of LSMC in the systemic and pulmonary circulations, in both elastic and muscular arteries. Three patterns could be distinguished: intimai cushions in muscular arteries, single or small groups of LSMC in the intima in elastic and larger muscular arteries, and intra-medially located layers or columns of LSMC in the aorta, the pulmonary artery, at the bifurcation of the aorta and around orifices of branches. In order to understand this peculiar orientation a biomechanical approach was used: this showed that near the lumen the circumferential stress is 4.5 times higher than the longitudinal. Because the cell surface of the smooth muscle cells exposed to this stress per unit vessel length is much less in the longitudinal than in the circular direction we conclude that the LSMC align in the direction which allows them to cope most effectively with the mechanical stresses.     

Contribution of the alanine-rich region of Streptococcus mutans P1 to antigenicity, surface expression, and interaction with the proline-rich repeat domain

Streptococcus mutans is considered to be the major etiologic agent of human dental caries. Attachment of S. mutans to the tooth surface is required for the development of caries and is mediated, in part, by the 185-kDa surface protein variously known as antigen I/II, PAc, and P1. Such proteins are expressed by nearly all species of oral streptococci. Characteristics of P1 include an alanine-rich repeat region and a centrally located proline-rich repeat region. The proline-rich region of P1 has been shown to be important for the translational stability and translocation of P1 through the bacterial membrane. We show here that (i) several anti-P1 monoclonal antibodies require the simultaneous presence of the alanine-rich and proline-rich regions for binding, (ii) the proline-rich region of P1 interacts with the alanine-rich region, (iii) like the proline-rich region, the alanine-rich region is required for the stability and translocation of P1, (iv) both the proline-rich and alanine-rich regions are required for secretion of P1 in Escherichia coli, and (v) in E. coli, P1 is secreted in the absence of SecB.     

Defects in regulation of apoptosis in caspase-2-deficient mice

During embryonic development, a large number of cells die naturally to shape the new organism. Members of the caspase family of proteases are essential intracellular death effectors. Herein, we generated caspase-2-deficient mice to evaluate the requirement for this enzyme in various paradigms of apoptosis. Excess numbers of germ cells were endowed in ovaries of mutant mice and the oocytes were found to be resistant to cell death following exposure to chemotherapeutic drugs. Apoptosis mediated by granzyme B and perforin was defective in caspase-2-deficient B lymphoblasts. In contrast, cell death of motor neurons during development was accelerated in caspase-2-deficient mice. In addition, caspase-2-deficient sympathetic neurons underwent apoptosis more effectively than wild-type neurons when deprived of NGF. Thus, caspase-2 acts both as a positive and negative cell death effector, depending upon cell lineage and stage of development.