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Biomedical subjects

I Florin

Publications and source records attributed to I Florin.

At least 55 records · Page 3Linked to original sources
PubMed1984

Polyphosphate-mediated protection from cellular intoxication with Clostridium difficile toxin B.

The influence of polyphosphorylated compounds on intoxication of human lung fibroblasts with Clostridium difficile toxin B was studied. ATP, as well as other nucleoside di-, tri-, and tetraphosphates, inorganic polyphosphates and polyphosphorylated sugars, caused a dose-dependent (1-5 mM range) delay in the appearance of the cytopathogenic effect. With a longer phosphate chain, the delay was more pronounced, although the cytopathogenic effect always developed finally, reaching the level of the control within 20 h. Toxin preparations contained one fraction of molecules able to bind ATP, besides one non-binding fraction. The protective effect of ATP did not depend on its energy producing ability. Neither was the protective effect due to an inactivation of the toxin per se, or to an interference with binding of the toxin to the cells. ATP was protective even upon addition 10 min after the toxin binding step. In the presence of ATP, the toxin remained accessible to neutralization with antitoxin. In analogy with the P-site on diphtheria toxin, we postulate that C. difficile toxin B contains a polyphosphate-binding site. This site is separate from the receptor-binding site, but involved in the interaction of toxin B with the cell surface shortly after the binding step.

Adenosine Triphosphate↗
PubMed1984

The impact of medical, reeducational, and psychological variables on rehabilitation outcome in amputees.

178 male unilateral above-knee amputees (cause of amputation: war injury or accident) participated in the study. Medical reeducational, social, vocational, and psychological predictor variables as well ad medical, social, vocational, and psychological outcome variables were assessed by means of interviews, expert ratings, questionnaires, and by ratings from the amputees partners. A series of risk factors for poor rehabilitation was specified by means of discriminant and correlational analyses. Optimization of medical/reeducational care, helping the amputee to gain insight into the necessity of amputation, making available to him a person to confide in with personal problems, and helping him to overcome social withdrawal seem to be the most important measures to prevent poor rehabilitation outcome.

Adolescent↗
PubMed1983

Internalization of Clostridium difficile cytotoxin into cultured human lung fibroblasts.

In cultured human lung fibroblasts treated with Clostridium difficile cytotoxin, the latency before appearance of the cytopathogenic effect was dose-related with a minimum of 45 min. At 37 degrees C, the toxin was accessible on all cells to inactivation with trypsin or neutralization with antitoxin during the first tenth of the latency. At 0 degrees C, the toxin was accessible considerably longer. The cytopathogenic effect was reversibly prevented by the lysosomotropic agents chloroquine and ammonium chloride, which had to be added within one-fifth of the latency to protect all cells. In the presence of chloroquine, but not of ammonium chloride, the time period during which the toxin remained amenable to neutralization with antitoxin was prolonged. The protective effect of ammonium chloride was not influenced by dropping the extracellular pH to 4.5, but that of chloroquine was abolished. The expression of the intoxication was not affected by inhibitors of the DNA, RNA or protein synthesis. Inhibitors of the energy metabolism prevented the cytopathogenic effect when added before the last phase of the latency. The results suggest that expression of the cytopathogenic effect requires internalization of the toxin, and that metabolic energy but no macromolecular synthesis is needed for the action of the toxin after this internalization.

Bacterial Proteins↗
PubMed1983

Expressed emotion and airway conductance in children with bronchial asthma.

Fourteen asthmatic children (ages 9-11) and their controls were exposed to a stress inducing competitive achievement situation. Facial expression of emotions were systematically analyzed from video-recordings, and peak expiratory flow rate (PEFR) reduction was measured from pre-stress to post-stress. The asthmatic children showed a significantly lower frequency and duration of overall emotional expression than their controls. Specifically, the frequency and duration of expressed anger/rage, enjoyment/joy, and surprise/startle were lower in the asthmatic children. Moreover, duration of overall expressed emotion showed a significant negative correlation with PEFR reduction in the asthmatic group, indicating a relevant relationship between facial expression of emotions and breathing function.

Airway Resistance↗
PubMed1983

Loss of surface fibronectin from human lung fibroblasts exposed to cytotoxin from Clostridium difficile.

Clostridium difficile cytotoxin caused an irreversible dose- and time-dependent loss of fibronectin from the surfaces of human lung fibroblasts, paralleling the appearance of the cytopathic effect. Fibronectin was not required for the intoxication process. The results lend further support to a transmembrane connective link between fibronectin and the microfilaments.

Bacterial Proteins↗
PubMed1983

Psychological correlates of functional secondary amenorrhoea.

15 women with functional secondary amenorrhoea and 15 controls (matched closely in age and educational status) were compared as to their knowledge of menstruation, their attitude towards those parts of the body likely to be associated with sexuality, and the amount of life events over the 6-month period preceding the onset of amenorrhoea, or an analogue time-span for control subjects. Comparison of means confirmed the research hypotheses: Knowledge of menstruation proved to be significantly lower and attitude towards sexuality-related body parts was significantly more negative in women with amenorrhoea than in control women (p less than 0.01 each). Also, in agreement with our expectations, subjects with amenorrhoea showed more problems in their partner-related sexuality than control subjects did (p less than 0.05), and had experienced more negative life events before the onset of amenorrhoea than the healthy group had over an analogue period of time (p less than 0.05).

Adolescent↗
PubMed1982

Bulimia nervosa: sex role attitude, sex role behavior, and sex role related locus of control in bulimarexic women.

Thirty-four women with bulimia nervosa and 34 women without bulimarexic symptoms (but matched for age, weight, deviance from ideal weight, and educational status) were compared as to how liberated their attitude towards the woman's role in society (= their sex role attitude, SRA) and their actual own behavior as females (= their sex role behavior, SRB) were. The degree to which their general attitude towards sex role and their own sex role behavior differed from each other was also investigated. Experimental and control group were also compared concerning their sex role related locus of control (SRLC). SRA and SRB were significantly less liberated in the bulimarexic group than in the control group. In addition, the bulimarexic group showed a wide gap between their general attitude (SRA) and actual behavior (SRB) as to the degree of liberation. No such discrepancy was found in the control subjects. The sex related locus of control data showed that bulimarexic women had significantly higher external and fatalistic control, and lower internal control than the comparison subjects.

Adult↗
PubMed1982

Mutagenicity of some indoles and related compounds in the Ames test.

A series of indole derivatives and some analogues were tested for mutagenic activity using a histidine-requiring mutant of Salmonella typhimurium (TA 98). Quantitative tests were performed with and without addition of a liver fraction (S-9) from rats induced with Aroclor 1254. Three compounds, 2,3-dimethylindole, 2,3,5-trimethylindole and 2,3,6-trimethylindole, showed a mutagenic effect which was not increased on metabolic activation. The influence on the mutagenic activity of the number and positions of the substituents attached to the indole skeleton is discussed.

Animals↗
PubMed1981

Intoxication of cultured human lung fibroblasts with Clostridium difficile toxin.

The cytopathogenic effect of partially purified toxin from Clostridium difficile on cultured human lung fibroblasts was studied. Conditions for determination of 50% tissue culture dose were standardized. The cytopathogenic effect of the toxin was dependent on toxin concentration, exposure time, and density of the cells. Transfer of the cells to 0 degrees C did not inhibit binding of toxin to the fibroblast surface, but prevented the development of the cytopathogenic effect. Both binding of toxin and some intracellular step(s) were prevented by 2,4-dinitrophenol. These preventative effects were reversible. Before and concomitantly with the appearance of the cytopathogenic effect, the cellular uptake of uridine and of amino acids was markedly stimulated. Protein synthesis was depressed when 100% of the cells showed the cytopathogenic effect, but the synthesis of nucleic acids was inhibited only several hours later. The primary cellular target for the toxin is still unknown.

Bacterial Toxins↗
PubMed1980

Screening of tobacco smoke constituents for mutagenicity using the Ames' test.

To clarify the mutagenic activity of individual smoke components, 239 compounds, representative of the gaseous and semivolatile phases of tobacco smoke, were assayed for mutagenicity towards 4 histidine-requiring mutants of Salmonella typhimurium (TA 98, TA 100, TA 1535 and TA 1537). All compounds were tested qualitatively both with and without metabolic activation using a liver fraction (S-9) from Aroclor 1254 or methylcholanthrene induced rats. Without S-9, only 2,3-dimethylindole and 2,3,5-trimethylindole showed mutagenic activity that was not enhanced by the metabolic activation system. 2,6-Diaminotoluene and coronene, which like the above compounds are not documented carcinogens were found to be mutagenic for strain TA 98 with S-9. Mutagenic activity was also observed for the previously known mutagens benz[a]pyrene, chrysene, benz[a]-anthracene, perylene and beta-naphthylamine, on exposure to strains TA 98 and/or TA 100 with S-9.

Amines↗
PubMed1972

[Behavior therapy].

Explore the source record for details and available documents.

Aversive Therapy↗
PubMedDate not supplied

Temptation, restriction, and alcohol consumption among American and German college students.

To assess relationships between alcohol consumption and two dimensions of drinking restraint (temptation and restriction), American and German college students were given the Khavari Alcohol Test (KAT) and the Temptation and Restraint Inventory (TRI). As hypothesized, drinking temptation was a positive predictor of students' alcohol consumption in both countries, but there was no main effect for drinking restriction. Also as hypothesized, American students who were high on drinking temptation drank greater (not smaller) quantities of alcohol if they were also high on drinking restriction. Conversely, German students who were high on drinking temptation drank more alcohol if they were also low on drinking restriction. The results point to cross-cultural similarities and differences in relationships between drinking temptation and restriction and actual alcohol consumption.

Adolescent↗
PubMedDate not supplied

Deliberate emotional expressions of socially anxious children and their mothers.

The aim of the present study was to investigate whether socially anxious children show deficits in their deliberate facial expression of emotions. To test for potential mother-child transmission effects, the mothers' facial expressions were also assessed. Fifty socially anxious and 25 socially nonanxious children (8-12 years) and their mothers participated in a facial expression posing task. The expressions produced were coded using Ekman and Friesen's (1978) Facial Action Coding System (FACS). In addition, naive raters rated their quality of emotion. FACS analyses indicated that socially anxious children show a reduced general facial activity, have a more restricted facial repertoire and differ qualitatively from controls in their facial expression of emotions. Similarly, the global ratings indicated that the socially anxious children's posed facial expressions are less accurate. For the mothers no differences between groups were found when global ratings were used. However, the FACS data demonstrate that the facial expressions of mothers of socially anxious children are less intense compared to controls. It is possible that the decreased intensity of the mothers' facial expressiveness makes it more difficult for the socially anxious children to learn adequate facial expressions.

Adult↗
PubMedDate not supplied

Facial expressions of emotion and physiologic reactions in children with bronchial asthma.

Eighteen children with bronchial asthma (ages 7.5 to 12) and 18 control children were exposed to a pleasant comic film and a stress-inducing achievement task. Facial expressions of emotion and heart rate (HR) were recorded, and pre- and posttest forced expiratory volume at 1 sec (FEV1) were assessed. The asthmatic children showed significantly fewer expressions of emotion than the control subjects in the stress-inducing but not in the joy-inducing situation. Their FEV1 decreased significantly under both experimental conditions, whereas no significant changes were found in the control group. The asthmatic children's mean HR was significantly higher under both experimental conditions than during the preceding pauses. In the control group, no significant changes in mean HR were found from the pause to the stressful situation; during the comic film, mean HR was significantly lower than during the preceding pause. No significant correlations were found for either group between number of emotions expressed, pre- to posttest changes in FEV1, and changes in mean HR.

Asthma↗