Sphingobacterium multivorum: case report and literature review.

We describe the case of a 67-year-old African American woman with multiple medical problems who presented with septic shock resulting from Sphingobacterium multivorum bacteraemia. S. multivorum, a Gram-negative bacillus, is ubiquitous in nature and is rarely involved in human infections. However, it is intrinsically resistant to many commonly administered antibiotics and can be a life-threatening microorganism.

Supported liquid membrane-protected molecularly imprinted beads for micro-solid phase extraction of sulfonamides in environmental waters.

In this work, molecularly imprinted polymer (MIP) beads have been prepared and evaluated for the development of a supported liquid membrane-protected micro-solid phase extraction method for the analysis of sulfonamides (SAs) in aqueous samples. The performance of MIP beads was firstly evaluated in cartridges by conventional solid-phase extraction for the simultaneous analysis of SAs. Afterward, beads were packed into a polypropylene hollow fiber protected by an organic solvent immobilized in the pores of the capillary wall. During the process, the analytes were extracted from the aqueous sample to the immobilized organic solvent and then selectively retained by the MIP beads located inside the capillary. The effect of various experimental parameters as sample pH, time and stirring-rate among others, were studied for the establishment of optimum rebinding conditions. Relative recoveries for all sulfonamides tested in river and reservoir water samples by the proposed method using 100mL water sample spiked with 50µg L-1 of each sulfonamide were within 70-120%, with a relative standard deviation (RSD) <10% (n=3). The detection limits (LODs) were within 0.2-3µgL(-1), depending upon the sulfonamide and the type of water used.

Effect of different dosage and administration schedules of folic acid on blood folate levels in a population of Honduran women of reproductive age.

BACKGROUND: Observational studies and clinical trials have shown conclusive evidence that periconceptional folic acid supplementation prevents up to 70 % of neural tube defects (NTD). The Honduran government wanted to implement a supplementation programme of folic acid but needed to assess the relative effects of two dosages of folic acid. OBJECTIVE: To determine the effect of two dosages of folic acid on blood folate levels in Honduran female factory workers aged 18 to 49 years. DESIGN: This was a randomized, double-blind control supplementation trial conducted in Choloma, Honduras. A total of 140 eligible women were randomly assigned to two dosage groups and followed up for 12 weeks. One group received a daily dosage of 1 mg folic acid and the other a once weekly dosage of 5 mg. Serum folate and red blood cell folate levels were determined by radioassay at baseline, 6 weeks and 12 weeks. RESULTS: Serum folate levels increased from 6.3 (se 0.2) to 14.9 (se 0.6) ng/ml (P < 0.0001) in women assigned to the 1 mg/d group and from 6.9 (se 0.3) to 10.1 (se 0.4) ng/ml (P < 0.0001) in those assigned to the 5 mg/week group. Red blood cell folate concentrations also increased significantly in both groups, albeit more slowly. Educational level, age and BMI were not associated with the changes in serum and red blood cell folate levels during the supplementation period. However, a differential effect on serum folate levels by dosage group and time was observed. CONCLUSIONS: Although both folate supplementation regimens increased serum and red blood cell folate levels significantly among the women studied, blood folate levels that are considered to be protective of NTD were reached faster with the daily dosage of 1 mg folic acid.

HLA-B2702 (77-83/83-77) peptide binds to beta-tubulin on human NK cells and blocks their cytotoxic capacity.

It has been described that peptides derived from a highly conserved region of the alpha1 helix of the first domain of HLA class I Ags exhibit immunomodulatory capacity blocking both T and NK cell cytotoxicity. In vivo treatment with these peptides prolongs survival of MHC-mismatched allografts. However, the molecular bases of these effects are still unclear. In this study, we further analyze the mechanisms by which the dimeric peptide HLA-B2702 (77-83/83-77) induces suppression of NK cell cytotoxicity. This peptide inhibits natural and redirected lysis mediated by NK cells without significantly affecting effector-target cell binding. We have also isolated and sequenced a protein that binds this inhibitory peptide, which structurally corresponds to beta-tubulin. Tubulin is the major protein of microtubules and is involved in target cell killing. Furthermore, B2702 peptide promotes GTP-independent tubulin assembly, producing aggregates that cannot be depolymerized by cold. Treatment of NK cells with Taxol or demecolcine, which interfere with microtubule organization, also prevents NK cell cytotoxicity. Taken together, these results support the hypothesis that the peptide B2702 (77-83/83-77) exerts its inhibitory effect on NK cell cytotoxicity by inducing polymerization of microtubules and interfering with their normal assembly/disassembly dynamics.

Prevención de la infección intrahospitalaria por staphylococcus aureus resistente a meticilina mediante el manejo de portadores / Prevention of methicillin resistant staphylococcus aureus nosocomial infection by elimination of carriers

La infección intrahospitalaria (iih) por samr tiene una alta prevalencia e implicancias terapéuticas y económicas. En la patogenia de la infección tienen importancia los portadores del agente, tanto funcionarios de salud como pacientes. En este estudio se realizó una investigación de portadores nasales de staphylococcus aureus y de samr en funcionarios de la unidad de cuidados intensivos, que mostró una tasa de 28,8 porciento (n:13) y 8,8 porciento (n:4) respectivamente. Los pacientes presentaron una tasa de portación de s. aureus de 33,5 porciento (n: 43) y de samr de 16,4 porciento (n:21), en diferentes períodos de hospitalización. Todos los portadores de samr se trataron con mupirocina endonasal, obteniéndose 100 porciento de erradicación con un ciclo de tratamiento en funcionarios y 85,7 porciento en pacientes, en los cuales se logró 100 porciento de erradicación con un segundo ciclo de tratamiento. La tasa de iih por samr en la uci durante el período de estudio descendió significativamente desde 5,19 porciento (año 1998) a 0,57 porciento (primer semestre 1999). Se concluye que el tratamiento de portadores reporta un importante beneficio, debiendo asociarse a otras medidas de control, como un adecuado lavado de manos en la atención de pacientes

Vigilancia de la sensibilidad a antimicrobianos de agentes productores de enfermedad invasora en pediatría / Surveillange of antimicrobial susceptibility of etiological agents causing invasive diseases in children

Haemophilus influenzae b, Streptococcus pneumoniae y Neisseria meningitidis constituyen un grupo de agentes productores de enfermedad invasora en pediatría, cuya incidencia puede estar determinada por variaciones epidemiológicas espontáneas o por la intervención mediante el uso de vacunas. En una revisión de 10 años en el Hospital Dr. Exequiel González Cortés se estudiaron los fenómenos de resistencia de estos microorganismos a los antimicrobianos comúnmente usados en su tratamiento, con referencia a su origen, mecanismos y a su expresión en el laboratorio. H. influenzae b y S pneumoniae han presentado resistencia de magnitud tal, que ha motivado cambios en los esquemas terapéuticos, en tanto N. meningitidis es un agente que sólo en los últimos años ha presentado resistencia a penicilina, en un rango que aún no justifica modificaciones de la terapia antimicrobiana en uso. dado que la expresión de resistencia no es uniforme en las diversas áreas geográficas, el fenómeno debe ser vigilado localmente, lo que permite la adecuación oportuna y eficaz de los esquemas terapéuticos, decisivos en el pronóstico de la patología causada por estos agentes

Engineered peptides corresponding to segments of the H3 domain of syntaxin inhibit insulin release both in intact and permeabilized mouse pancreatic beta cells.

Syntaxin is one of the proteins involved in the exocytotic event through sequential binding to specific proteins, including SNAP25 and synaptobrevin. In a previous work in digitonin-permeabilized beta cells, we characterized the functional role of two segments: synA and synB of the H3 domain of syntaxin. As a continuation of these experiments in the present study we have initially outlined a zone of 17 residues as the very effective uncoupling element of the synA segment. Further functional studies have been accomplished in intact pancreatic beta cells with a specific myristoylated (myr) 13-mer peptide comprised in this active zone. These experiments showed a concentration-dependent inhibition of glucose-induced insulin release (IC50 = 4 microM) of this engineered peptide that was specific since a myristoylated random peptide with the same composition was ineffective. A second myristoylated 13-mer peptide comprised into the synB segment was shown to be even more potent promoting a selective inhibition of insulin release. These data show for the first time, that nutrient-induced secretory process can be specifically uncoupled in intact beta cells demonstrating at the same time that syntaxin plays a central role in this mechanism.

Condom use among high-risk women in Honduras: evaluation of an AIDS prevention program.

In 1988, the Honduran Ministry of Health initiated an intervention study designed to increase AIDS awareness and promote preventive behavior, especially condom use, among registered commercial sex workers (CSWs). The program consisted of weekly talks and free condom distribution to all CSWs who attended the sexually transmitted disease clinic during a 10-week period. Pre- and postintervention surveys were used to evaluate change in knowledge and condom use. Condom diaries were used to measure condom use during the program. One hundred thirty-four women who participated in the intervention completed the initial and follow-up surveys. There was a statistically significant increase in mean condom use from 64% to 70% of client contacts. Condom use recorded in diaries during the program period appeared even higher. Factors found to be associated with increased use postintervention include low baseline condom use and higher client fee. The reliability of the methods of measuring condom use and the implications of the findings for future intervention studies among sex workers and their clients are discussed.

Estimating infant mortality rates prospectively in Honduras.

In order to determine the validity of infant mortality estimates based on retrospective reporting, the Honduran Ministry of Health carried out a follow-up survey of women interviewed in a 1987 national survey. Women were interviewed approximately 14 months after the baseline survey and were asked about the outcomes of their pregnancies and the survival status of their young children. The overall infant mortality rate calculated from the follow-up survey was lower than that obtained from the baseline survey, due to the particularly low rate among the group of women who were pregnant at the time of the baseline survey. Possible explanations for this low rate are discussed.

PIP: Indirect and direct methods may be used to estimate infant mortality rate (IMR). Respondents surveyed retrospectively about births, deaths, and corresponding dates often, however, omit or misreport vital events. Prospective studies virtually eliminate the potential for these types of errors. To test the validity of IMR estimates based upon retrospective reporting, this paper compares the former with estimates drawn from baseline survey data obtained 14 months prior. Baseline data came form 10,159 women ages 15-44, interviewed in 1987, by the Ministry of Health of Honduras. 1048 women were pregnant at baseline, and IMR was estimated to be 48/1000. The follow-up survey questioning pregnancy outcome and survival status of respondents' young children achieved a 74% response rate, and yielded an estimated IMR of 26/1000 for newborns. IMR estimated from follow-up data is probably unrealistically low given mortality trends and socioeconomic conditions in HOnduras. 3 sources of error potentially contributing to low IMR for the cohort of newborns are considered: pregnancy denial, unreported, and underreporting of pregnancies. Future studies should be conducted with more than 1048 pregnant women, baseline survey should be improved to better detect pregnancies, and regional and community studies should be considered in an effort to reduce study cost and boost response rates at follow-up.