Virulence determinants of Escherichia coli O6 extraintestinal isolates analysed by Southern hybridizations and DNA long range mapping techniques.

A total of 16 Escherichia coli O6 strains isolated from cases of extraintestinal infections were analysed for the genetic presence and phenotypic expression of fimbrial adhesins (P, S/FIC, type 1), aerobactin and hemolysin. In addition restriction fragment length polymorphisms (RFLPs) of Xbal-cleaved genomic DNA of seven selected strains, separated by orthogonal field alternation gel electrophoresis (OFAGE) were determined and virulence-associated DNA probes were used for Southern hybridization studies of the Xbal-cleaved genomic DNAs. The virulence characteristics and hybridization patterns obtained differed between the various isolates. In three isolates hemolysin genes and P fimbrial determinants were located on the same Xbal fragments. Furthermore, multiple copies of FIC determinants (foc) could be detected in two strains. Our data show that the new technique of pulse field electrophoresis together with Southern hybridization represents a powerful tool for the genetic analysis of pathogenic bacteria.     

The role of the human acetylation polymorphism in the metabolic activation of the food carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ).

The metabolic activation of the heterocyclic food carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) by two human cytochrome P450 monoxygenases (P4501A1 and P4501A2) and two human N-acetyltransferases (NAT1 and NAT2) was investigated. Various combinations of these enzymes were functionally expressed in COS-1 cells. DNA adducts resulting from the activation of IQ were assayed quantitatively by the 32P-postlabeling procedure. The highest adduct frequency was observed in cells expressing both CYP1A2 and NAT2. CYP1A2 in combination with NAT1 was 3-6 times less active. When expressed alone these enzymes gave rise to low adduct frequencies. Experiments with N-acetyl-IQ as substrate suggest that NAT1 and NAT2 in addition to their known role in N-acetylation display arylhydroxamic acid N, O-acetyltransferase (AHAT) activity. Quantitative differences in adduct formation between IQ and N-acetyl-IQ indicated that metabolic activation of these arylamines preferentially occurs by P4501A2-catalyzed N-hydroxylation followed by O-acetylation mediated through NAT1 and/or NAT2. These data, in combination with the known genetic polymorphism of NAT2, may explain the clinical observation that the acetylation polymorphism constitutes a risk factor in the carcinogenic activation of environmental mutagens.     

Demographic and risk factors associated with chronic dieting in adolescents

A comprehensive, school-based survey was administered to 36,320 Minnesota public school students in grades 7 through 12 during the 1987-1988 school year. Self-reported chronic dieting was much higher in girls than in boys (12.1% of all girls vs 2.1% of boys). For girls, the percentage of chronic dieters was significantly less in grades 7 and 8 (7.8%) than in grades 9 and 10 (13.5%) or grades 11 and 12 (14.3%). There were no differences among urban, suburban, or rural youth. Black girls were less likely to diet compared with white girls. Chronic dieters were more likely than other students to report maladaptive weight-loss techniques, such as self-induced vomiting (relative risk, 9.92 for girls and 9.40 for boys), laxative use (relative risk, 7.18 for girls and 11.00 for boys), ipecac use (relative risk, 8.33 for girls and 11.00 for boys), and diuretic use (relative risk, 7.30 for girls and 13.5 for boys). It is suggested that chronic dieting may serve as a screening marker for more severe eating and weight-loss behaviors.     

Does cardiac SPECT using attenuation and scatter correction accurately predict coronary artery disease in a minority women population?

BACKGROUND: Myocardial perfusion imaging (MPI) is a well-established diagnostic method for evaluation and risk stratification of coronary artery disease (CAD).We undertook this study to validate both the positive predictive value (when compared to cardiac catheterization) and the prognosis afforded by MPI in a group of minority women patients. MATERIAL/METHODS: The database of our Nuclear Imaging and Catheterization Laboratory was retrospectively queried for consecutive minority (African-American, Hispanic and Asian) women patients who underwent MPI and cardiac catheterization within 90 days of each other. Patients with recent revascularization were excluded. Attenuation/scatter correction was utilized in the final interpretation of the study. RESULTS: Of the 54 women patients who underwent MPI, 7 underwent exercise stress testing, 26 had stress testing with adenosine, 18 with dipyridamole and 3 with dobutamine. Eighteen patients (53%) had same number of vessels predicted by MPI and coronary angiography (7 patients with triple vessel disease, 7 with 2-vessel disease and 4 with single vessel disease). Five (3 with intermediate and 2 with high risk scans) out of the 54 patients (9.3%) were dead at 2 years. The sensitivity, specificity and positive predictive value of MPI as compared to angiography were 87.2%, 26.7%, 75.6% and 44.4% respectively. CONCLUSIONS: The sensitivity of MPI in this group of patients is comparable to the general population though the specificity is lower in spite of using attenuation and scatter correction. Low risk perfusion scan signifies favorable prognosis at 2 years with regards to mortality.     

Incidence and clinical features of traveler's diarrhea in infants and children

To assess the incidence rate and the characteristics of traveler's diarrhea in small children ages 0 to 2 years, children ages 3 to 14 years, and adolescents ages 15 to 20 years a retrospective survey was conducted. Of the pretravel visitors to the Zurich University Vaccination Center, all those ages 0 to 20 years were selected between October, 1987, and May, 1988. They received a questionnaire within 2 weeks after returning home. Of the 446 young travelers who were recruited, 363 (81.3%) could be evaluated. Within 14 days in the tropics or subtropics, traveler's diarrhea occurred in 8 of 20 (40.0%) small children, in 4 of 47 (8.5%) children ages 3 to 6 years, in 10 of 46 (21.7%) children ages 7 to 14 years and in 90 of 250 (36.0%) adolescents (P = 0.0003). In small children the clinical course tended to be severe and prolonged (average duration, 29.5; median, 17.5 days) when compared with other age groups (3 to 5 days). In 40% of all the children the parents reported that they had consistently practiced dietary preventive measures. For self-treatment oral rehydration solutions were used in 5.0% and loperamide in 33.8%. In conclusion adults should be discouraged from taking small children to developing countries unless necessary. Parents should be instructed about how to prevent traveler's diarrhea and about the mainstay of self-therapy in pediatric patients by oral rehydration solutions.     

Bolus or continuous hydrocortisone – that is the question

Constantly evolving treatment guidelines based on a growing body of randomized controlled trials are helping us to improve outcomes in sepsis. However, it must be borne in mind that proven benefit from individual sepsis treatments does not guarantee synergistic beneficial effects when new treatments are added to sepsis management. Indeed, unexpected harmful interactions are also possible. A good example of this is the conflict between intensive insulin therapy and 'low dose' hydrocortisone in septic shock. The goal of tight glycaemic control is made more complicated by steroid-induced hyperglycaemia. In their recent study, Loisa and coworkers demonstrate a measure that reduces the risk for this interaction. They found continuous infusion of hydrocortisone to be associated with fewer hyperglycaemic episodes and reduced staff workload compared with bolus application.     

The link between contraceptive methods andChlamydia trachomatis infection

The effect of various contraceptive methods onChlamydia trachomatis (CT) infection was examined in a group of 158 women, with a mean age of 26.9 years, patients of a family planning clinic. Their symptoms were mild abdominal pain or vaginal discharge. Antibodies to CT were examined by an indirect immunoperoxidase assay, with a commercial kit. From each patient a vaginal smear was collected for bacteriologic and mycologic study.In group I, consisting of 30 married women with a mean age of 31 years, 5 (16.7%) IUD users had a positive test for CT antibodies. In group II, comprising 57 women, with a mean age of 23.3 years, 22 (38.6%) oral contraceptive (OC) users, of whom 94.7% were unmarried, had positive tests for CT antibodies. The difference between these two groups was statistically significant (p<0.05).In group III, comprising 71 women with a mean age of 28.1 years, 62% unmarried and using other contraceptive methods, 15 (21.1%) had a positive test for CT antibodies. The incidence of CT infection was not different in the 3 groups under study, when the factors of age and marital status were taken into consideration (p>0.30). Bacterial vaginal infection was found in 43.3% of the IUD users, compared with only 14% of the OC users (p<0.01).In contrast, in the OC users, candidiasis was predominant, the difference from the other groups being statistically significant (p<0.001). The women with positive antibodies also more frequently had colonies of bacterial and mycological vaginal infection. CT infection is a sexually transmitted disease (STD) related to a specific and non-monogamous sexual life style. The unmarried women in the group of OC users are the most at risk, taking into consideration that they begin sexual life at an early age and that they often change their partners.

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Resumen El efecto de varios métodos anticonceptivos en la infección porChlamydia trachomatis (CT), fué examinado en un grupo de 159 pacientes con 26,9 años de edad media, en una clinica de planificación familiar. Sus síntomas fueron: dolor leve abdominal o flujo vaginal. Se examinaron los anticuerpos a CT mediante una prueba comercial de immunoperoxidase indirecta. Se obtuvo un extendido vaginal de eada paciente para un estudio bacteriológico y micológico.En el grupo I, constituido por 30 mujeres casadas con 31 años de edad media, 5 (16,7%) usuarias de DIU tuvieron una prueba de anticuerpos positiva a CT. En el grupo II, constituido por 57 mujeres con 23.3 aflos de edad media, siendo usuarias de anticonceptivos orales (OC) y 94,7% solteras, 22 (38,6%) tuvieron resultados positivos a anticuerpos de CT. La diferencia entre estos dos grupos fue estadísticamente significativa (p<0,05).En el grupo III, constituido por 71 mujeres con 28,1 años de edad media, siendo 62% solteras y usando otros métodos anticonceptivos, 15 (21,1%) tuvieron una prucba de anticuerpos CT positiva. La incidencia de infección de CT no fue diferente en los 3 grupos de estudio cuando se tuvieron en consideracion los factores de edad y estado civil (p>0,30). Se encontró infección bacteriana vaginal en 43,3% de las usuarias de DIU, comparado con 14% de OC (p<0,01).A diferencia, en usuarias de OC predominó la candidiasis, siendo estadísticamente significativa (p<0,001) con otros grupos. Las mujeres con anticuerpos CT positivos, mas frecuentemente tuvieron colonias de infección bacteriana y micológica. La infección CT es una enfermedad transmitida sexualmente (STD), relacionada con un grupo especifico, no monógamo de vida sexual. Las solteras en este grupo de usuarias de OC, son las que tienen el mayor riesgo considerando que empiezan su vida sexual a edad mas temprana y que cambian de pareja con frecuencia.

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Resumé L'effet de diverses méthodes contraceptives sur l'infection par laChlamydia trachomatis (CT) a été examiné sur un groupe de 158 femmes dont l'âge moyen était de 26,9 ans qui fréquentaient un clinique de planning familial. Elles présentaient comme symptômes des douleurs abdominales légères et des pertes vaginales. Les anticorps à la CT ont été examinés par un essai indirect à l'immunoperoxydase effectué au moyen d'un matériel commercial. On a procédé à un frottis vaginal sur chaque patiente aux fins d'une étude bactériologique et mycologique.Dans le groupe I, comprenant 30 femmes mariées âgées en moyenne de 31 ans, l'essai sur les anticorps à la CT, chez les 5 utilisatrices de DIU (16,7%), a donné des résultats positifs. Dans le groupe II, comptant 57 femmes d'un âge moyen de 23,3 ans, les utilisatrices de contraceptifs oraux, dont 94,7% étaient célibataires, 22 (38,6%) ont produit des résultate positifs à l'essai sur les anticorps à la CT. La différence entre ces deux groupes était significative du point de vue statistique (p<0.05).Quant au groupe III, composé de 71 femmes âgées en moyenne de 28,1 ans, dont 62% n'étaient pas mariées et faisaient appel à d'autres méthodes contraceptives, les résultats de l'essai sur les anticorps à la CT ont été positifs dans 15 cas. L'lneidence de l'infection par la CT ne différait pas dans les trois groupes étudiés lorsqu'on a tenu compte des facteurs d'âge et de statut matrimonial (p>0.30). L'infection bactérienne vaginale a été retrouvéc chez 43.3% des utilisatrices de DIU, alors qu'elle était de 14% chez les femmes qui prenaient des contraceptifs oraux (p<0.01). Par contre, chez ces dernières, la candidose était prédominante, révélant une différence statistiquement signifieative avae les autres groupes (p<0.001). En outre, les femmes ayant des anticorps positifs à la CT présentaient plus souvent des colonies d'infection vaginale bactériennes et mycologiques. L'infection par la CT est une maladie sexuellement transmissible (MST) liéc à une activité sexuelle spécifique et non monogame. Les femmes célibataires du groupe des utilisatrices de contraceptifs oraux sont les plus exposées à ces risques, compte tenu du fait que leur activité sexuelle commence tôt et qu'elles changent souvent de partenaires.

     

Kommentar auf Anforderung der Schriftleitung zur Arbeit: Endoskopisch kontrollierte Stabilisation von Humerusschaftfrakturen von R. Zobrist et al.

Die Unfallchirurgie -