Facilitation of macrofaunal assemblages in marinas by the habitat-forming invader Amathia verticillata (Bryozoa: Gymnolaemata) across a spatiotemporal scale.

Widespread habitat-forming invaders inhabiting marinas, such as the spaghetti bryozoan Amathia verticillata, allow exploring facilitation processes across spatiotemporal contexts. Here we investigate the role of this bryozoan as habitat for native and exotic macrofaunal assemblages across different ecoregions of Western Mediterranean and East Atlantic coasts, and a monthly variation over a year. While only 7 (all peracarid crustaceans) of the 54 associated species were NIS, they dominated macrofaunal assemblages in terms of abundance, raising the potential for invasional meltdown. NIS richness and community structure differed among marinas but not among ecoregions, highlighting the importance of marina singularities in modulating facilitation at spatial scale. Despite facilitation did not depend on bryozoan abundance fluctuations, it was affected by its deciduous pattern, peaking in summer and disappearing in late winter. Monitoring A. verticillata in marinas, especially in summer periods, may improve the detection and management of multiple associated NIS.

α-Glucosidase inhibitory phenolics from Echeveria subrigida (B. L. Rob & Seaton) leaves.

Echeveria subrigida is native to Mexico and its methanol extract (ME) shows relevant biological activities for human health, including the α-glucosidase inhibitory (αGI) activity that suggests its antidiabetic potential. Fractionation of the ME based on the αGI activity (IC50 in µg/mL) showed that quercetin-3-O-ß-glucoside (131.1), isorhamnetin-3-O-ß-glucoside (166.4), and dimers to heptamers proanthocyanidins (9.6) were among the main responsible of αGI activity in the ME. The purified compounds showed better activity than acarbose (IC50 = 4426 µg/mL).

[Treatment with bisphosphonates improves the quality of life in patients with diagnosis of osteogenesis imperfecta]. / El tratamiento con bifosfonatos mejora la calidad de vida en pacientes con diagnóstico de osteogénesis imperfecta.

INTRODUCTION: Osteogenesis imperfeta (OI) is defined as a heterogeneous group of hereditary diseases, which present with the presence of bone fragility, frequent fractures, bone deformities and short stature. Treatment with biphosfonates in patients with diagnosis of OI has shown a decrease in the frecuency of fractures, as well as an improvement in vertebral bone density. There is little evidence on quality of life in patients diagnosed with OI treated with bisphosphonates, Therefore this study evaluated the quality of life of patients diagnosed with OI after treatment with bisphosphonates. MATERIAL AND METHODS: It is a prospective, deliberate intervention, self-controlled clinical trial. Nine patients with ages between two and thirteen ages and diagnosed with OI were treated with Zolendronic, a quality of life measurement was performed in the patients before and after the application. For measuring the quality of life in the patients we used the PedsQL 4.0 quality of life survey that was applied to both children and parents. RESULTS: In the quality of life survey performed on the parents, an increase was observed in the four dimensions evaluated. In the survey made on the children two dimensions showed a significant increase. The number of fractures decreased after the treatment. CONCLUSIONS: There is a correlation between the decrease in the number of fractures and the perception that both parents and children have in the quality of life after treatment with bisphosphonates.

INTRODUCCIÓN: La osteogénesis imperfecta (OI) es un grupo heterogéneo de enfermedades hereditarias, las cuales cursan con la presencia de fragilidad ósea, fracturas frecuentes, deformidades óseas y talla baja. El tratamiento con bifosfonatos en los pacientes con diagnóstico de OI ha demostrado un decremento en la frecuencia de fracturas, así como una mejoría en la densidad ósea vertebral. Existe poca evidencia sobre la calidad de vida en pacientes con OI posterior al tratamiento con bifosfonatos. ¿Los bifosfonatos mejoran la calidad de vida de los pacientes con OI? MATERIAL Y MÉTODOS: Se trata de un ensayo prospectivo, de intervención deliberada, ensayo clínico autocontrolado. Nueve pacientes que se encontraban entre las edades de dos y 13 años con diagnóstico de OI fueron tratados con ácido zolendrónico. Se realizó una medición de la calidad de vida en los pacientes previa y posteriormente. Para la medición de la calidad de vida de los pacientes utilizamos la encuesta de calidad de vida PedsQL 4.0 que fue aplicada tanto a los niños como a los padres. RESULTADOS: En la encuesta de calidad de vida efectuada a los padres se observó un incremento en las cuatro dimensiones evaluadas. En la encuesta realizada a los niños se apreció un aumento en dos dimensiones. El número de fracturas disminuyó posterior al tratamiento. CONCLUSIONES: Existe una correlación entre la disminución del número de fracturas y la percepción que tienen tanto los padres como los niños en la calidad de vida posterior al tratamiento con bifosfonatos.

El tratamiento con bifosfonatos mejora la calidad de vida en pacientes con diagnóstico de osteogénesis imperfecta / Treatment with bisphosphonates improves the quality of life in patients with diagnosis of osteogenesis imperfecta

Resumen: Introducción: La osteogénesis imperfecta (OI) es un grupo heterogéneo de enfermedades hereditarias, las cuales cursan con la presencia de fragilidad ósea, fracturas frecuentes, deformidades óseas y talla baja. El tratamiento con bifosfonatos en los pacientes con diagnóstico de OI ha demostrado un decremento en la frecuencia de fracturas, así como una mejoría en la densidad ósea vertebral. Existe poca evidencia sobre la calidad de vida en pacientes con OI posterior al tratamiento con bifosfonatos. ¿Los bifosfonatos mejoran la calidad de vida de los pacientes con OI? Material y métodos: Se trata de un ensayo prospectivo, de intervención deliberada, ensayo clínico autocontrolado. Nueve pacientes que se encontraban entre las edades de dos y 13 años con diagnóstico de OI fueron tratados con ácido zolendrónico. Se realizó una medición de la calidad de vida en los pacientes previa y posteriormente. Para la medición de la calidad de vida de los pacientes utilizamos la encuesta de calidad de vida PedsQL 4.0 que fue aplicada tanto a los niños como a los padres. Resultados: En la encuesta de calidad de vida efectuada a los padres se observó un incremento en las cuatro dimensiones evaluadas. En la encuesta realizada a los niños se apreció un aumento en dos dimensiones. El número de fracturas disminuyó posterior al tratamiento. Conclusiones: Existe una correlación entre la disminución del número de fracturas y la percepción que tienen tanto los padres como los niños en la calidad de vida posterior al tratamiento con bifosfonatos.

Abstract: Introduction: Osteogenesis imperfeta (OI) is defined as a heterogeneous group of hereditary diseases, which present with the presence of bone fragility, frequent fractures, bone deformities and short stature. Treatment with biphosfonates in patients with diagnosis of OI has shown a decrease in the frecuency of fractures, as well as an improvement in vertebral bone density. There is little evidence on quality of life in patients diagnosed with OI treated with bisphosphonates, Therefore this study evaluated the quality of life of patients diagnosed with OI after treatment with bisphosphonates. Material and methods: It is a prospective, deliberate intervention, self-controlled clinical trial. Nine patients with ages between two and thirteen ages and diagnosed with OI were treated with Zolendronic, a quality of life measurement was performed in the patients before and after the application. For measuring the quality of life in the patients we used the PedsQL 4.0 quality of life survey that was applied to both children and parents. Results: In the quality of life survey performed on the parents, an increase was observed in the four dimensions evaluated. In the survey made on the children two dimensions showed a significant increase. The number of fractures decreased after the treatment. Conclusions: There is a correlation between the decrease in the number of fractures and the perception that both parents and children have in the quality of life after treatment with bisphosphonates.

The Rehm-Weller experiment in view of distant electron transfer.

The driving-force dependence of bimolecular fluorescence quenching by electron transfer in solution, the Rehm-Weller experiment, is revisited. One of the three long-standing unsolved questions about the features of this experiment is carefully analysed here, that is, is there a diffusional plateau? New experimental quenching rates are compiled for a single electron donor, 2,5-bis(dimethylamino)-1,3-benzenedicarbonitrile, and eighteen electron acceptors in acetonitrile. The data are analysed in the framework of differential encounter theory by using an extended version of the Marcus theory to model the intrinsic electron-transfer step. Only by including the hydrodynamic effect and the solvent structure can the experimental findings be well modelled. The diffusional control region, the "plateau", reveals the inherent distance dependence of the reaction, which is shown to be a general feature of electron transfer in solution.

Production of free radicals and triplets from contact radical pairs and from photochemically generated radical ions.

The quantum yields of triplets and free radicals (or radical ions) that escaped recombination in photochemically created primary radical pairs (or radical ion pairs) are calculated. As the products of monomolecular photodissociation, the neutral radicals appear at contact, while the ions are initially distributed over the space due to distant photoionization (bimolecular electron transfer) in the liquid solution. The diffusional dependence of the quantum yields is shown to be different when recombination starts from contact or from separated reactants. The experimental data for recombination of ionized perylene with aromatic amine counterions is well fitted with the noncontact initial distribution provided the recombination is also noncontact and even more distant than ionization.

Probing the behavior of confined water by proton-transfer reactions.

The picosecond dynamics of a bifunctional and H-bonding molecule, 7-hydroxyquinoline (7HQ), has been studied in a reverse micelle with increasing water content. The fluorescence kinetics has a complex behavior as the water content is changed. All reactions are irreversible, and a two-step mechanism is invoked to explain the observations. H2O/D2O exchange and excitation energy effects show that the second step has a higher barrier and that the corresponding reaction occurs through tunneling. The results clearly indicate two regimes of water nanopool behavior switching at W0 approximately 5 (W0 = [water]/[surfactant]). Water collective dynamics explains these observations. The lower fluidity of confined water within the reverse micelle with respect to normal bulk water alters the related H-bond network dynamics and therefore is responsible for the slower proton-transfer processes.

Linezolide e infección del tracto urinario / Linezolide and urinary tract infection

No disponible

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000).

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participated during 1999-2000; they collected 1806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced beta-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced beta-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the beta-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000)

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participat ed during 1999-2000; they collected 1,806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1 percent) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3 percent) were penicillin-resistant and 79 (15.3 percent) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5 percent) and erythromycin (31.2 percent) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9 percent) produced b-lactamase, ranging from 11 percent (Brazil) to 24.5 percent (Mexico). Among M. catarrhalis isolates, 138 (98.6 percent) produced b-lactamase. Twenty-four (8.7 percent) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5 percent of the S. aureus isolates (Argentina 15 percent; Mexico 20 percent; Brazil 31.3 percent). Telithromycin was effective against 97.7 percent of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the b-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy

[The active efflux pump in antimicrobial resistance]. / La bomba de expulsión activa en la resistencia a los antimicrobianos.

Active efflux of antibiotics is one of the different resistance mechanisms of bacteria against antimicrobial agents. The rapid exit of the antibiotic from the bacteria prevents its interaction with target point. This mechanism, also known as active efflux pump, is very important since it can explain the simultaneous resistance to several antibiotic families. There are four main active efflux systems: MFS, RND, Smr and ABC. This review includes all of them, together with their transporting proteins, the bacteria that have those proteins and the phenotype of the antibiotics affected. The complex genotype regulation systems, including codifying genes, positive and negative regulators, chromosomal or plasmidic localization is also studied. Finally, the causes of marked resistance to antimicrobial agents of isolated strains in the clinic, especially in hospital areas are revised. The role of the European Antimicrobial Resistance Surveillance System (EARSS) in the evaluation of those resistances is discussed.

[Emerging mycoses]. / Micosis emergentes.

The incidence of new pathogenic agents in the fungi group has been on the rise over the past few years. This can be explained by the similar increase in elderly patients, precarious situations or immunodeficient states, together with the high degree of instrumentation in hospitals and the indiscriminate use of antibiotics and antimycotics both to cure and prevent. This study includes emerging fungi, isolated in the aforementioned individuals, which belong to the filamentous and dimorphic fungi groups, and yeasts. In view of their number, only the main ones are mentioned, together with the clinical manifestations they produce and the grounds for their diagnosis and treatment.

A simple saliva-based test for detecting antibodies to human immunodeficiency virus.

This study was performed to determine the feasibility of using saliva as a diagnostic medium for the detection of antibodies to human immunodeficiency virus type 1 (HIV-1) and HIV-2 under nonlaboratory conditions and to evaluate the performance characteristics of such a test. We developed for this purpose a self-contained kit (Saliva. Strip [ST]), which combines the collection and processing, as well as the analysis, of the specimen. The kit's performance was evaluated in a blinded study. Saliva collection was facilitated with a specially designed device that contains a sample adequacy indicator, and immunochromatography test strips were used for the analysis. A total of 1,336 matched serum and saliva specimens (684 reactive and 652 nonreactive specimens) were tested. We tested sera using an enzyme immunoassay (EIA) and a rapid strip test. Sera reactive in one of the assays were also analyzed by Western blotting. Sensitivity and specificity were 99.4 and 99.4%, respectively, for ST, 100 and 99.1%, respectively, for EIA, and 99.7 and 100%, respectively, for the serum strip test. The saliva test performed well when HIV-2-positive sera or a low-titer performance panel (HIV-1) of serum or plasma specimens were diluted (1:2,000) in nonreactive saliva. Because the methodology we present here uses a noninvasively obtained medium, the methodology may be suitable for use in the field where laboratory support and personnel are limited, such as community outreach programs, doctors' offices, surveillance studies, and community hospitals.

[A comparative study of western blot interpretation criteria for Lyme disease serological diagnosis in our environment]. / Rentabilidad comparada de los criterios de interpretación del Western-blot para el diagnóstico serológico de la enfermedad de Lyme en nuestro medio.

We have studied the WB reliability for the Lyme disease (LD) serological diagnosis. Twenty five samples (20 sera and 5 CSF) from 5 patients with LD, according to CDC criteria were analyzed. The syphilis was excluded in every patient. Borrelia burgdorferi antibodies were assessed by an indirect ELISA (IgG + IgM, B31 strain). Intrathecal antibodies in CSF were studied in patients with neurological diseases. Positive samples by ELISA were reanalyzed by WB according to the manufacturer, Tilton and Dressler criteria and presence either 93, 39, 34 or 23 kDa band for IgG. Four patients were controlled and one of them (25%) became negative the antibodies (serorreversion). Three of them, who had neurological symptoms, displayed intrathecal antibodies. WB sensibility for LD according to the manufacturer, Tilton, Dressler and any of the four IgG bands was 26.31%, 42.1%, 21% and 84% for IgG and 52.6%, 47.3% and 42.1% for IgM respectively. Tilton and Dressler criteria may not be as sensible as 93, 39, 34 or 23 kDa IgG bands for the diagnosis of LD in our environment.

A simple whole-blood test for detecting antibodies to human immunodeficiency virus.

We developed an immunochromatographic whole-blood test (WBT) which detects antibodies to human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) from fingerstick blood. The sensitivity and specificity of the WBT were 99.41% (1,018 confirmed positive patients) and 99.89% (941 uninfected patients), respectively (enzyme immunoassay [EIA] on serum or plasma as a reference). WBT performance was comparable to those of licensed EIAs and Western blotting, using 18 HIV-2 sera, 23 HIV-1 seroconversion panels, and a low-titer performance panel (in lieu of whole blood).

Crytococcus neoformans var. gattii in an AIDS patient: first observation in Mexico.

We report the first, as far as we know, Mexican case of meningitis caused by Cryptococcus neoformans var. gattii serotype B associated with AIDS in a female patient. The HIV was transmitted to the patient through a blood transfusion. This patient represents, worldwide, the ninth case of C. neoformans var. gattii in patients with AIDS.

A field test for the detection of antibodies to human immunodeficiency virus types 1 and 2 in serum or plasma.

In response to the need for simple and rapid tests for infectious diseases, we have devised a test for antibodies to human immunodeficiency virus type 1 (HIV-1) and HIV-2 which resembles many contemporary strip-style pregnancy tests in format and ease of use. The test was evaluated with 2,928 serum specimens (1,541 reactive and 1,387 nonreactive) collected and tested at a Mexico City hospital clinic and was compared with a laboratory assay (Abbott) performed simultaneously. The sensitivity and specificity of the test using these serum specimens were 99.68 and 99.71%, respectively (before the code of the blinded study was broken). This compares with 100% sensitivity and 97.55% specificity with the laboratory assay (specificity upon reassay after the code was broken, 99.21%). In a survey of HIV-2 specimens, reactive (positive) specimens were detected in 51 of 51 cases. The test was examined with 21 commercially available (HIV-1) seroconversion panels. The performance of the test was comparable to that of a group of Food and Drug Administration-approved (antibody-based) HIV tests.

PIP: Simple and rapid methods of detecting infectious disease are needed. The authors therefore developed a test for antibodies to HIV-1 and HIV-2 which resembles many contemporary strip-style pregnancy tests in both format and ease of use. The test was evaluated with 1541 reactive and 1387 nonreactive serum specimens collected and tested at a Mexico City hospital clinic. A laboratory assay was performed simultaneously. The sensitivity and specificity of the test using these serum specimens were 99.68% and 99.71%, respectively. The laboratory assay was 100% sensitive and 97.55% specific. All reactive HIV-2 specimens were detected. The test was examined with 21 commercially available HIV-1 seroconversion panels. The performance of the authors' test was comparable to that of a group of Food and Drug Administration approved HIV tests.