Distribution of insertion sequence IS200 among different clonal lines of the related Salmonella serotypes Livingstone and Eimsbuettel

The copy number and genetic location of IS200 have provided evidence of strain relatedness in many serotypes of Salmonella. In this study, 100 isolates of the related serotypes Livingstone (6,7:d:l,w) and Eimsbuettel (6,7,14:d:l,w), representing 10 ribotype/biotype (RT/BT) groups isolated from human and non-human sources in seven countries over a 26-year period, were examined for their IS200 profiles. The distribution of IS200 in strains of these serotypes was limited, being present in all 53 isolates of ribotype 1 (RT1) and its variant type RT6, in one of five isolates of RT5 but in none of 42 isolates of RTs 2, 3 or 4. Although the seven IS200 profiles identified in RT1 isolates were of little value for further discrimination within different biotype groups, they were extremely valuable for confirming serotype: isolates of RT1/BT8/IS200 profile A (or its variants) and those of RT1/BT3/IS200 profile B (or its variants) were almost invariably associated with serotypes Livingstone and Eimsbuettel, respectively.     

Polarity influences the efficiency of recombinant adenoassociated virus infection in differentiated airway epithelia

To better understand mechanisms that limit rAAV transduction in the lung, we have evaluated several unique features of rAAV infection in polarized primary airway epithelial cultures. rAAV was found to transduce the basolateral surface of airway epithelia 200-fold more efficiently than the apical membrane. These differences in membrane infection correlated with the abundance of apical heparan sulfate proteoglycan (AAV-2 receptor) and virus binding. UV irradiation augmented rAAV transduction greater than 20-fold, only when virus was applied to the apical membrane. Ultrastructural analysis of UV-irradiated primary cultures demonstrated significant changes in microvilli architecture following exposure to 25 J/m2 UV. Although virus binding and the abundance of heparan sulfate proteoglycan were not increased at the apical membrane following UV irradiation, increased receptor-independent endocytosis of fluorescent beads was seen at the apical membrane following UV irradiation. We hypothesize that endocytotic processes associated with apical membrane-specific pathways of viral entry, and/or processing of virus to the nucleus, may be altered following UV irradiation. Interestingly, UV irradiation had an inhibitory effect on rAAV transduction from the basolateral membrane, which correlated with a decrease in the abundance of heparan sulfate proteoglycan at the basal membrane. In summary, these findings suggest that independent pathways of viral transduction may occur in the apical and basolateral compartments of polarized airway epithelia.     

Evaluation of the results of cleft lip and palate surgical treatment: preliminary report

We have analysed randomized controlled studies which reported the incidence of postoperative nausea and vomiting (PONV) after propofol anaesthesia compared with other anaesthetics (control). Cumulative data of early (0-6 h) and late (0-48 h) PONV were recorded as occurrence or non-occurrence of nausea or vomiting. Combined odds ratio and number-needed-to-treat were calculated for propofol as an induction or maintenance regimen, early or late outcomes, and different emetic events. This was performed for all control event rates and within a range of 20-60% control event rates. We analysed 84 studies involving 6069 patients. The effect of propofol on PONV was dependent mainly on the method of administration, time of measurement and range of control event rates. When all studies were included the number-needed-to-treat to prevent PONV with propofol was more than 9 when used for induction of anaesthesia and at best 6 when used for maintenance. Within the 20-60% control event rate range, best results were achieved with propofol maintenance to prevent early PONV: the number-needed-to-treat to prevent early nausea was 4.7 (95% confidence interval 3.8-6.3), vomiting 4.9 (4-6.1) and any emetic event 4.9 (3.7-7.1). Within the 20-60% control event rate, of five patients treated with propofol for maintenance of anaesthesia, one will not vomit or be nauseated in the immediate postoperative period who would otherwise have vomited or been nauseated. This may be clinically relevant. In all other situations the difference between propofol and control may have reached statistical significance but was of doubtful clinical relevance. Treatment efficacy should be established within a defined range of control event rates for meaningful estimates of efficacy and for comparisons.     

Posttraumatic stress disorder symptoms after bone marrow transplantation for breast cancer

Hormonal treatments which have an androgenic effect have the potential to cause vocal changes. The changes in vocal fold structure and voice quality are considered to be irreversible. To date, studies have documented subjective vocal changes or documented single cases without detailed, baseline voice assessments. The impact on laryngeal function of women taking these androgenic treatments requires further detailed, objective assessment. The need for increased awareness of the actions of androgenic hormones on womens' voices, and the benefits of a thorough voice assessment are discussed.     

Environment and health: an analysis of intra-urban differentials in the city of S?o Paulo, Brazil

A field study undertaken in the city of S. Paulo is presented as part of the project Environment and Health in Developing Countries: An Analysis of Intra-Urban Differentials Using Existing Data financed by the Ministry of Foreign Affairs of the United Kingdom with academic support from the London School of Hygiene and Tropical Medicine (LSHTM). The research aim was to fill in the gaps in the information needed to establish associations between mortality, urbanization and the environment. Statistics were produced by means of existing data collected by city departments, research carried out by universities and census data. Data quality was assessed taking into consideration data coverage, accuracy, and sensibility to pinpoint deprived areas in the city of S. Paulo. Socioeconomic data were used to create a composite index for districts and subdistrict in order to form four socioeconomic zones. Mortality differentials between the zones by five broad age groups (0-4, 5-14, 15-44, 45-64 e 65+) and four ICD chapters (circulatory, respiratory, infectious and parasitic and external causes) are presented. The zoning used showed that 43.8% of S. Paulo residents live in areas under the worst socioeconomic conditions. Health data demonstrated that people living in this areas had higher rates of mortality then those living in the areas with the best conditions. Finally, excess mortality data are analyzed and suggested as a good method for allocating health resources.     

Tissue reactions to bacteria-challenged implantable leads with enhanced infection resistance

Tissue reactions to implantable pacemaker leads were investigated in an early infection model in rabbits. Both standard leads and surface-modified leads were used. The surface modification technique was applied to achieve controlled release of the antibiotic gentamicin. The insulating polyurethane tubing material of the leads was provided with an acrylic acid/acrylamide copolymer surface graft and then loaded with gentamicin. Implantation periods varied from day 4, to week 3 1/2, to week 10. We investigated tissue reactions in the absence of an infectious challenge and also the efficacy of surface-modified leads in preventing infection after challenge with Staphylococcus aureus was evaluated. It was demonstrated that the applied surface modification did not induce adverse effects although during early postimplantation an increase in infiltration of granulocytes and macrophages and wound fluid and fibrin deposition were observed. After bacterial challenge, standard leads were heavily infected at each explantation period, denoted by abscesses, cellular debris, and bacterial colonies. In contrast, little or no infection was observed, either macroscopically or by bacterial cultures, with the surface-modified leads. Microscopy showed little evidence of the bacterial challenge, and that primarily at day 4. It was concluded that the applied surface modification demonstrated enhanced infection resistance and thus represents a sound approach to the battle against infectious complications with biomaterials.     

Comparison of diarrhea induced by ingestion of fructooligosaccharide Idolax and disaccharide lactulose: role of osmolarity versus fermentation of malabsorbed carbohydrate

Whether carbohydrate malabsorption causes diarrhea probably depends on the balance between the osmotic force of the carbohydrate and the compensatory capacity of the colon to dispose of the carbohydrate by bacterial fermentation. The present study evaluated the specific role of the osmolarity by comparing the severity of diarrhea after ingestion of two nonabsorbable carbohydrates, the fructooligosaccharide Idolax and the disaccharide lactulose. Both carbohydrates are readily fermented by the colonic flora but differ in osmolarity, the osmotic force being twice as high for lactulose as for Idolax. Twelve subjects were given increasing doses (0, 20, 40, 80, 160 g/d) of Idolax and lactulose in a crossover design. Every dose level was administered for three days with intervals of one week. Stools were collected on the third day to determine 24-hr volume, concentrations of short-chain fatty acids, L- and D-lactate, residues of Idolax or lactulose, sodium, potassium, pH, osmolarity, and in vitro productions of organic acids. Measured by short-chain fatty acid and lactate formation in a fecal incubation system, the fermentation of Idolax and lactulose was identical and very rapid compared with a range of reference carbohydrates. A laxative effect of both Idolax and lactulose was demonstrated. The increment in fecal volume as a function of the dose administered was twice as high for lactulose (slope of the regression line = 7.3, r = 0.64, P< 10(-5)) as for Idolax (slope = 3.7, r = 0.51, P<10(-3)), i.e., isosmolar doses of lactulose and Idolax had the same effect on fecal volume. The variation in fecal volume was substantial (lactulose 80 g/day: 110-1360 g/day; Idolax 160 g/day: 130-1440 g/day). High responders had earlier and larger fecal excretions of the saccharide compared with low-responders. Fecal volume in carbohydrate-induced diarrhea is proportional to the osmotic force of the malabsorbed saccharide, even though all or the majority of the saccharide is degraded by colonic bacteria. The capacity to modify the diarrhea varies considerably from person to person and is associated with colonic saccharide disposal, whereas the variation in response to isosmolar amounts of different saccharides is small within the same individual.     

The principal rapamycin-sensitive p70(s6k) phosphorylation sites, T-229 and T-389, are differentially regulated by rapamycin-insensitive kinase kinases

Mitogen-induced activation of p70(s6k) is associated with the phosphorylation of specific sites which are negatively affected by the immunosuppressant rapamycin, the fungal metabolite wortmannin, and the methylxanthine SQ20006. Recent reports have focused on the role of the amino terminus of the p85(s6k) isoform in mediating kinase activity, with the observation that amino-terminal truncation mutants are activated in the presence of rapamycin while retaining their sensitivity to wortmannin. Here we show that the effects of previously described amino- and carboxy-terminal truncations on kinase activity are ultimately reflected in the phosphorylation state of the enzyme. Mutation of the principal rapamycin-targeted phosphorylation site, T-389, to an acidic residue generates a form of the kinase which is as resistant to wortmannin or SQ20006 as it is to rapamycin, consistent with the previous observation that T-389 was a common target of all three inhibitors. Truncation of the first 54 residues of the amino terminus blocks the serum-induced phosphorylation of three rapamycin-sensitive sites, T-229 in the activation loop and T-389 and S-404 in the linker region. This correlates with a severe reduction in the ability of the kinase to be activated by serum. However, loss of mitogen activation conferred by the removal of the amino terminus is reversed by additional truncation of the carboxy-terminal domain, with the resulting mutant demonstrating phosphorylation of the remaining two rapamycin-sensitive sites, T-229 and T-389. In this double-truncation mutant, phosphorylation of T-229 occurs in the basal state, whereas mitogen stimulation is required to induce acute upregulation of T-389 phosphorylation. The phosphorylation of both sites proceeds unimpaired in the presence of rapamycin, indicating that the kinases responsible for the phosphorylation of these sites are not inhibited by the macrolide. In contrast, activation of the double-truncation mutant is blocked in the presence of wortmannin or SQ20006, and these agents completely block the phosphorylation of T-389 while having only a marginal effect on T-229 phosphorylation. When the T-389 site is mutated to an acidic residue in the double-truncation background, the activation of the resulting mutant is insensitive to the wortmannin and SQ20006 block, but interestingly, the mutant is activated to a significantly greater level than a control in the presence of rapamycin. These data are consistent with the hypothesis that T-389 is the principal regulatory phosphorylation site, which, in combination with hyperphosphorylation of the autoinhibitory domain S/TP sites, is acutely regulated by external effectors, whereas T-229 phosphorylation is regulated primarily by internal mechanisms.