Physical attractiveness and the personality resemblance of identical twins

The physical attractiveness of 25 pairs of monozygotic (MZ) twins was rated independently for twins A and B. The MZ twins were rated alike in their physical attractiveness (r=0.54; corrected for attenuation,r=0.94). Physical attractiveness was uncorrelated with verbal intelligence but was associated, controlling statistically for the sex difference in attractiveness favoring females, with three of the eight traits in the Comrey inventory: Conformity, Extraversion, and Emotional Stability. In both sexes, greater emotional stability was associated with attractiveness; in males greater extraversion; and in females, greater conformity. When these twin correlations were adjusted for this association with attractiveness, the mean change in the value ofr was only 0.03, indicating that physical attractiveness does not appear to bias conclusions from twin studies.     

Psychological factors affecting pulmonary and rheumatologic diseases. A review

This review examines some of the questions and current literature regarding psychological factors as they affect pulmonary and rheumatologic diseases. Recommendations are made concerning directions for future research in these areas.     

Effect of Pseudomonas aeruginosa cytotoxin on thymidine incorporation by murine splenocytes.

The interaction of highly purified Pseudomonas aeruginosa cytotoxin (PAC) with murine splenocytes was examined. Added at culture initiation, PAC (0.1 to 0.5 microgram/ml) inhibited subsequent [3H]deoxythymidine incorporation measured between 42 to 48 h. Incorporation of [3H]deoxythymidine was inhibited 50% in lipopolysaccharide-, phytohemagglutinin-, and concanavalin A-stimulated cultures by 0.20, 0.32, and 0.39 microgram of PAC per ml, respectively. It is concluded that PAC exhibits a narrow inhibitory concentration response range of 0.1 to 0.5 microgram/ml which, secondarily, is affected by the presence of mitogens. Antitoxin added at splenocyte culture initiation, directly after PAC, yielded greater than or equal to 86% protection against PAC inhibition of [3H]deoxythymidine incorporation. Addition of antitoxin to cultures at different times after PAC demonstrated a time-dependent loss of antitoxin protective effect over a 12-h period, indicating that PAC became cell associated and refractory to antitoxin within this time period. PAC preincubated with splenocytes at 4 degrees C for less than or equal to 1 h could not be removed by washing of cells and was fully inhibitory to [3H]deoxythymidine incorporation when these cells were cultured at 37 degrees C. This finding was confirmed by demonstrating that 125I-labeled PAC bound immediately to cells. It is concluded that PAC action on splenocytes is dose- and time-dependent and consists of a two-phase process: (i) a very rapid binding of PAC to the cell surface available to antitoxin, and (ii) a slower toxicity development phase of ca. 12 h, during which PAC becomes refractory to antitoxin.     

Variations in Helicobacter pylori lipopolysaccharide to evade the innate immune component surfactant protein D

Helicobacter pylori is a common and persistent human pathogen of the gastric mucosa. Surfactant protein D (SP-D), a component of innate immunity, is expressed in the human gastric mucosa and is capable of aggregating H. pylori. Wide variation in the SP-D binding affinity to H. pylori has been observed in clinical isolates and laboratory-adapted strains. The aim of this study was to reveal potential mechanisms responsible for evading SP-D binding and establishing persistent infection. An escape variant, J178V, was generated in vitro, and the lipopolysaccharide (LPS) structure of the variant was compared to that of the parental strain, J178. The genetic basis for structural variation was explored by sequencing LPS biosynthesis genes. SP-D binding to clinical isolates was demonstrated by fluorescence-activated cell sorter analyses. Here, we show that H. pylori evades SP-D binding through phase variation in lipopolysaccharide. This phenomenon is linked to changes in the fucosylation of the O chain, which was concomitant with slipped-strand mispairing in a poly(C) tract of the fucosyltransferase A (fucT1) gene. SP-D binding organisms are predominant in mucus in vivo (P = 0.02), suggesting that SP-D facilitates physical elimination. Phase variation to evade SP-D contributes to the persistence of this common gastric pathogen.     

Review of Technology: Planning for the Development of Telesonography

Teleradiology allows contemporaneous interpretation of imaging exams performed at some distance from the interpreting radiologist. The transmitted images are usually static. However, there is benefit to real-time review of full-motion ultrasound (US) exams as they are performed. Telesonography is transmission of full-motion sonographic data to a remote site. We hypothesize that US exams, read after having been compressed utilizing Motion Picture Experts Group version 4 (MPEG-4) compression scheme, transmitted over the Internet as streaming multimedia, decompressed, and displayed, are equivalent in diagnostic accuracy to reading the examinations locally. MPEG-4 uses variable compression on each image frame to achieve a constant output bit rate. With less compression, the bit rate rises, and the only way the encoder can contain bit rate within the set bandwidth is by lowering frame rate or reducing image quality. We review the relevant technologies and industry standard components that will enable low-cost telesonography.     

Interaction of lipopolysaccharides of Helicobacter pylori with basement membrane protein laminin.

The ability of hemagglutinating and poorly hemagglutinating strains of the gastroduodenal pathogen Helicobacter pylori to bind 125I-radiolabelled laminin was quantitated in a liquid phase assay. Although all strains bound laminin, some hemagglutinating strains were good binders of laminin (maximum of 31% binding), whereas poorly hemagglutinating strains bound intermediate to small amounts of laminin (minimum of 6% binding). Since a hydrophobic component of the bacterium has been reported to be involved in binding of laminin (T. J. Trust, P. Doig, L. Emödy, Z. Kienle, T. Wadström, and P. O'Toole, Infect. Immun. 59:4398-4404, 1991), we investigated the role of lipopolysaccharide (LPS) in the interaction of both types of strains with laminin. Although the extent of inhibition varied among strains, laminin binding to hemagglutinating and poorly hemagglutinating strains was inhibited with homologous and heterologous smooth-form LPS. The ability of heterologous rough-form LPS to produce inhibition comparable to that shown by smooth-form LPS indicated that the O side chain of H. pylori LPS was not involved in the interaction. Further inhibition experiments with dephosphorylated LPS, isolated core oligosaccharide, and free lipid A suggested that a phosphorylated structure in the core oligosaccharide mediates the interaction of a hemagglutinating strain of H. pylori with laminin, whereas a conserved nonphosphorylated structure in the core oligosaccharide mediates the interaction of a poorly hemagglutinating strain. Furthermore, we showed that the interaction of H. pylori LPS with 125I-radiolabelled laminin in a solid phase assay was saturable, specific, and inhibitable with unlabelled laminin. It was postulated that the initial recognition and binding of laminin by H. pylori may occur through LPS and that subsequently a more specific interaction with a lectin-like adhesin on the bacterial surface occurs.     

Immunogenicity in guinea pigs and tolerance in grass pollen-sensitive volunteers of enteric-coated grass pollen allergens

An acid-insoluble, methacrylic acid, methyl methacrylate copolymer (Eudragit L-100) was used to give an enteric coating to a grass pollen extract in order to protect it against gastric degradation. Substantial protection against the degradative effects of simulated gastric secretion was demonstrated using this preparation which was well tolerated by grass pollen-allergic volunteers. The enteric-coated allergen induced a greater secondary antibody response than did an aqueous presentation when administered orally to guinea pigs which had been primed previously by subcutaneous injection. This result indicates that an effective hyposensitisation regimen could consist of a short series of initial parenteral injections, followed by an oral course of the protected allergen.     

Serological analysis of the heat-stable antigens involved in serotyping Campylobacter jejuni and Campylobacter coli

Analysis with serotyping antisera showed that carbohydrate determinants were the dominant heat-stable antigens of Campylobacter jenuni/coli involved, whereas proteins did not contribute to the serological reactions. Lipopolysaccharide (LPS) along with a polysaccharide extract from whole bacteria (PS(WB] conferred strain serospecificity. In general, analysis with monoclonal antibodies in passive haemagglutination and co-agglutination tests showed the existence of similar antigenic determinants in LPS and PS(WB) of the same strain. However, in some strains determinants were detectable in LPS but not in PS(WB) using monoclonal antibodies, in other strains the situation was reversed. All of these monoclonal antibodies reacted with LPS in the more sensitive immunoblotting technique. The presence of 2-keto-3-deoxyoctonic acid in PS(WB) preparations, in the absence of endotoxin, supported the conclusion that PS(WB) was derived from LPS during extraction. The lack of detection of a reaction by monoclonal antibodies with LPS in passive haemagglutination, in contrast to immunoblotting, was suggested due to the presence of low concentrations of the relevant epitopes because of the procedure used to prepare the LPS tested.     

Expression and modulation of Rho kinase in human pregnant myometrium

There is little information outlining the role of Rho kinase, RhoA, and calcium sensitization in regulation of human uterine contractility during pregnancy. The aims of this study were to investigate the expression of RhoA, and the Rho kinases ROCK I and ROCK II in human pregnant myometrium, to evaluate the effects of Rho kinase inhibition on pregnant human myometrial contractility in vitro, and to compare these effects with those of the calcium channel blocker nifedipine. RT-PCR using primers for RhoA, ROCK I and ROCK II was performed on mRNA isolated from human pregnant myometrium. Isometric recording was performed in isolated myometrial strips obtained at Caesarean section. The effects of the Rho kinase inhibitor Y-27632 (1 nmol/l to 10 mmol/l), and nifedipine (1 nmol/l to 10 mmol/l), on oxytocin (0.5 nmol/l) induced contractions were measured and compared. Expression of RhoA, ROCK I and ROCK II mRNA was identified in human pregnant myometrium (n = 3). Y-27632 exerted a potent relaxant effect on myometrial contractility with a pD(2) value (+/- SEM) of 7.63 +/- 0.38 (n = 6). The maximum net relaxant effect (+/- SEM) was 72.3 +/- 6.1% (n = 6). Corresponding values for nifedipine were 7.24 +/- 0.48 (n = 6; P = 0.469) and 93.40 +/- 3.1% (n = 6; P = 0.028). Rho A/Rho kinase-mediated calcium sensitization may play role in the physiology of human parturition, and pharmacological inhibition of this pathway may therefore provide a novel approach to tocolysis for pre-term labour.