Ventilation/carbon dioxide production ratio in early exercise predicts poor functional capacity in congestive heart failure

Production of cytokines by immunocompetent cells in vitro may be assessed after stimulation with polyclonal activators. Because it mimics the natural environment, diluted whole blood (WB) culture may be the most appropriate milieu in which to study cytokine production in vitro. We tested TNF alpha production by small volume of whole blood (25 microliters) from HIV-1 positive patients by using a one-step procedure that combines WB stimulation with LPS and PHA and cytokine measurement. We studied 30 patients without secondary infection or at distance of secondary infection staged according to the classification proposed by the CDC and 12 healthy seronegative subjects. The mean values of TNF alpha from patients were not statistically different from those from normal controls however in certain patients at different stages of the disease higher values than the mean +2 SD of controls and lower values than the mean -2 SD of controls were obtained. Heparinized blood from 5 control subjects had been collected sequentially during a period of 5 months. The individual variation of TNF alpha production were limited for all these individuals. For each of 6 HIV-1 patients, whole blood samples were collected sequentially during a period of 5 months and in most of patients large variations of levels of TNF alpha were observed from one sample to another one. Our method can detect abnormal cytokine production in HIV-1 positive individuals and can become a useful tool to investigate the role of cytokines in the outcome of HIV-1 infection.     

Sexually transmitted infection as a cause of anal cancer

Interviews were carried out with 423 women and 93 men with invasive or in situ anal cancer in Denmark and Sweden in a search for clues to the aetiology of this neoplasm. Patients with rectal adenocarcinoma (n = 534) and persons drawn from the background population (n = 554) served as controls. Multivariate logistic regression analyses confirmed previous observations of a strong association between either male homosexual experience or a history of anogenital warts and the risk for anal cancer. Moreover, hitherto unknown, but strong and consistent associations were observed between measures of high heterosexual activity and the risk for anal cancer among both sexes. Polymerase chain reaction analysis revealed human papilloma-virus DNA in the majority (88%) of anal cancer specimens but in none of 20 examined rectal adenocarcinomas. It is concluded that most anal cancers appear to be caused by sexually transmitted types of human papillomaviruses and, consequently, that anal cancer is a potentially preventable neoplasm.     

In vitro maintenance of Schistosoma japonicum and surgical transfer from donor to na?ve recipient pigs

The insulin receptor (IR) is a membrane-bound glycoprotein composed of alpha and beta subunits derived from a common precursor. This processing is observed for both subtypes A and B of the IR and its physiological importance is poorly understood. In order to investigate the functional consequences of the absence of IR precursor cleavage, using site-directed mutagenesis of the hIRB cDNA, we have produced two mutants replacing the sequence Arg-Lys-Arg-Arg by either His-Lys-His-Arg or Arg-Lys-Arg-Ser. These two mutants, stably expressed in CHO, were structurally and functionally characterized in comparison to the wild-type human IR. These mutations result in the production of uncleaved receptors which are expressed normally at the cell surface. These receptors bind insulin with a normal affinity and activate the tyrosine-kinase resulting in normal phosphorylation of the receptors. These uncleaved receptors can mediate both the metabolic and mitogenic effects of insulin. These results provide evidence for a fully functional uncleaved insulin receptor of the B subtype (exon 11 + ) in contrast to the uncleaved A subtype (exon 11 -) described in the literature, which shows a reduced affinity for insulin and cannot therefore correctly transduce the insulin signal.     

Bi-directional relations between anti-smoking parenting practices and adolescent smoking in a Dutch sample.

Objective: Parenting is generally regarded a determinant of adolescent behavior, whereas the reverse is seldom considered. Reported effects of anti-smoking parenting practices on adolescent smoking are inconsistent. Cross-sectional results may have been misinterpreted and child effects have been overlooked. The main goal of this study was to explain previous inconsistent effects of anti-smoking parenting practices, by examining bi-directional relations between parenting and adolescent smoking. Design and Main Outcome Measures: Bi-directional relations were studied using a cross-lagged model where anti-smoking house rules, communication about smoking, and adolescent smoking were assessed at three subsequent years. Results: The most prominent finding was that adolescent smoking behavior was a stronger predictor of parenting than vice versa. Anti-smoking house rules decreased as a result of adolescent smoking behavior, while communication increased. The reduction in house rules was more pronounced if parents smoked, while the increase in communication was greater for non-smoking parents. Results were independent of adolescent sex. Conclusion: Further research is needed to establish which aspects of parenting can be effective in deterring adolescent smoking. This study emphasizes the need for caution in interpreting cross-sectional research findings relating parenting to adolescent smoking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oberflächenaktive Derivate der Rizinolsäure

Surface Active Derivatives of Ricinoleic Acid Studying the dependence of tenside properties on their constitution, often all the attention is paid to the hydrophilic end, whereas the hydrophobic end is of minor importance. Studies of tensides for many years, produced of special fatty acids, have shown that these have a significant influence on many tenside properties. That does not only regard the special tenside properties as e.g. foaming, washing, purifying and emulsifying but especially the dermatological and lexicological compatibility of these compounds. Ricinoleic acid or its soaps and triglycerides have been known for long as substances which are very well tolerated by skin. Partly they contain marked skin protection or skin preserving properties. It is therefore of significant interest in which way these properties can be transferred to synthetic tensides. This was investigated as well with anionic and non ionogenic derivatives of the ricinoleic acid as with amphoter and kationic derivatives and led partly to surprising results.     

Associations between skeletal muscle properties, physical fitness, physical activity and coronary heart disease risk factors in men

High physical fitness and physical activity are associated with favourable lipid levels, especially a high level of high density lipoprotein cholesterol (HDL-C). A person's skeletal muscle properties, metabolism and percentage of different muscle fibres (ST-%), which may modify coronary heart disease (CHD) risk factors, such as serum insulin, obesity and serum sex hormones may also influence his fitness level and leisure-time physical activity. We studied the associations of physical fitness, physical activity and ST-% with serum lipids and lipoproteins in 72 healthy men. Their parameters were compared with those of 20 men with defined CHD. Significant interrelationships between ST-%, fitness and leisure-time physical activity index (LTPAI) were observed. Multiple regression analysis showed that ST-%, fitness and leisure-time physical activity explained about 32% of the variation in HDL-C in the healthy men. In healthy men ST-% correlated positively with fitness (r(s) = 0.62, P < 0.001) and with LTPAI (r(s) = 0.62, P < 0.001). Fitness level also correlated significantly with LTPAI (r(s) = 0.81, P < 0.001). Serum insulin showed negative associations with ST-% (r(s) = -0.63, P < 0.001) and fitness (r(s) = -0.54, P < 0.001) and LTPAI (r(s) = -0.62, P < 0.001). Free fraction of testosterone correlated negatively with serum HDL-C level (r(s) = -0.34, P < 0.01), with fitness (r(s) = -0.41, P < 0.001) and with LTPAI (r(s) = -0.54, P < 0.001). In sedentary men with the lowest fitness and physical activity the mean of ST-% (45%) was similar to that in CHD patients (44%). However, ST-% in men in the highest tertile of physical activity and fitness (68%) was significantly higher than in CHD patients and in men in the lowest tertile of physical activity and fitness. Skeletal muscle enzyme activity in lipid metabolism was significantly lower in both CHD patients and in sedentary and low-fit men than that in fitter and physically active men. The present data imply that skeletal muscle properties are important determinants of risk profiles, such as physical activity, fitness and serum lipid and lipoprotein patterns. Although fitness is a graded, independent predictor of mortality from CHD, a relatively high fitness level is not enough. This was clearly observed in the clustering analysis, in which the healthy men, according to their ST-%, fitness, leisure-time physical activity and serum sex hormone binding globulin (SHBG), fell into three natural groups: (i) Inactive men with lowest ST-% (mean 42%), lowest fitness (10.7 METs) and lowest HDL-C (1.36 mm/l); (ii) Fit men with high ST-% (66%), high fitness (14.5 METs) and moderately high HDL-C (1.54 mol/l); (iii) Active men with high ST-% (66%), highest fitness (14.9 METs) and highest serum HDL (1.83 mmol/l). The results support the idea that both fitness and physical activity give further protection against CHD by modifying risk factors. Our findings also suggest that skeletal muscle properties should be considered in the studies which assess CHD risk factors and their modifications especially in the field of health-related fitness.     

Blends and alloys of vinyl—technology and applications

The use of multiphase polymers is of growing importance because of their inherent economical and technological benefits. The basic characteristics of multiphase polymer blends and alloys are covered. The advantages of vinyl as a component are discussed in light of its ease of processing, inherent compatibility, fire resistance, weatherability, and a wide range of properties achievable. Blend morphology is reviewed and related to the mechanical properties. Typical examples of commercial materials and their application are reviewed.     

Bioactive diversity and screening library selection via affinity fingerprinting

The Similarity Principle provides the conceptual framework behind most modern approaches to library sampling and design. However, it is often the case that compounds which appear to be very similar structurally may in fact exhibit quite different activities toward a given target. Conversely, some targets recognize a wide variety of molecules and thus bind compounds that have markedly different structures. Affinity fingerprints largely overcome the difficulties associated with selecting compounds on the basis of structure alone. By describing each compound in terms of its binding affinity to a set of functionally dissimilar proteins, fundamental factors relevant to binding and biological activity are automatically encoded. We demonstrate how affinity fingerprints may be used in conjunction with simple algorithms to select active-enriched diverse training sets and to efficiently extract the most active compounds from a large library.     

Comment/correction: dependability modeling using Petri nets

Two arcs are missing in a figure of Malhotra & Trivedi (see ibid., vol. 44, p. 428-40, 1995); these arcs are necessary for the proper functioning of the generalized stochastic Petri net (GSPN). Also, priorities of immediate transitions in that figure must be clearer. This note presents a correctly drawn GSPN and describes the priority assignment to immediate transitions in this GSPN