Pathogenic vibrios in the oyster Crassostrea virginica in the lagoon system of Mandinga, Veracruz, Mexico

Oyster consumption has been associated to the transmission of pathogenic bacteria, including those from the genus Vibrio. The objective of this investigation was to determine the concentrations of Vibrio parahaemolyticus and V. alginolyticus in Crassostrea virginica from the lagoon system of Mandinga, Veracruz, and their relationships with salinity and water temperature. Only the periods of greater production and consumption of oysters were examined: the dry and rainy seasons during 2008. Four sampling sites were selected, from which three samples were collected per site per season, resulting in a total of 24 samples. Each sample consisted of 30 oysters of commercial size that were subsequently analyzed using serial dilution. Biochemical analysis of the resulting bacterial colonies revealed concentrations of V. parahaemolyticus and V. alginolyticus ranged from < 3 to 150 MPN/g. A positive correlation was observed between temperature and the concentration of V. parahaemolyticus (r = 0.69, p < 0.05), while the correlation with salinity was negative (r = -0.68, p < 0.05). No significant correlations between the concentration of V. alginolyticus and water temperature and salinity were observed for the rainy season. The main contribution of this paper is to establish safe areas and periods for oyster extraction

Estudio del comportamiento de la corrosión de los aceros inoxidables am 350 y custom 450 pasivados en medio ácidos

En este trabajo se estudia el comportamiento de los aceros inoxidables AM 350 y Custom 450 en medios corrosivos de NaCl al 5% y H2SO4 al 1%. Los cuales fueron pasivados en ácido cítrico y ácido nítrico, a temperaturas de 25 y 49oC, con tiempos de inmersión de 60 y 90 minutos. La técnica Electroquímica empleada fue Polarización potenciodinámica, utilizando un potenciostato/galvanostato/ZRA "Gill AC Instruments". Las demandas de corriente en solución de NaCl son de 10-4 mA/cm2, mientras que las de H2SO4 están alrededor de 10-2 y 10-3 mA/cm2. También se realizó la determinación de la microestructura de los materiales establecidos, su morfología y composición química, a través de la microscopía óptica y microscopía electrónica de barrido. Se comprobó que el que ácido cítrico funciona como solución pasivante y en algunos casos la resistencia a la corrosión es equiparable con la del ácido nítrico

Electrochemical corrosion behavior of passivated precipitation hardening stainless steels for aerospace applications

Precipitation-hardening (PH) stainless steels (SS) are widely used in various aerospace applications. These steels exhibit good mechanical and corrosion resistance. The electrochemical behavior of 15-5PH, 17-4PH, Custom450 and AM 350 stainless steels passivated with citric and nitric acid baths for 60 and 90 min at 25 and 49 °C were evaluated in 5 wt.% sodium chloride (NaCl) and 1 wt.% sulfuric acid (H2SO4) solutions. The electrochemical behavior was studied with potentiodynamic polarization curves (PPC) according to the ASTM G5-13 standard. The results indicated that there are two characteristic mechanisms that are present in the potentiodynamic polarization curves. When the PHSS is immersed in an H2SO4 solution, there is a secondary passivation, and in the NaCl solution, there is a pseudo-passivation (not stable passivation film). The current densities in the NaCl solution were between 10−4 and 10−5 mA/cm2, while those of H2SO4 were recorded around 10−2 and 10−3 mA/cm2. Citric acid does work as a passivating solution, and in some cases, the corrosion resistance of the stainless steel was comparable to that of nitric acid

Cervical determinants of anal HPV infection and high-grade anal lesions in women: a collaborative pooled analysis

Cervical cancer screening might contribute to the prevention of anal cancer in women. We aimed to investigate if routine cervical cancer screening results-namely high-risk human papillomavirus (HPV) infection and cytohistopathology-predict anal HPV16 infection, anal high-grade squamous intraepithelial lesions (HSIL) and, hence, anal cancer.International Agency for Research on Cance

The use of plants in the traditional management of diabetes in Nigeria: Pharmacological and toxicological considerations

Ethnopharmacological relevance: The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system. Materials and methods: Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. ‘Diabetes’ and ‘Nigeria’ were used as keywords for the primary searches; and then ‘Plant name – accepted or synonyms’, ‘Constituents’, ‘Drug interaction’ and/or ‘Toxicity’ for the secondary searches. Results: The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs. Conclusion: This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb–drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided

A new bluing species of Psilocybe (Basidiomycota, Agaricales, Strophariaceae) - The first record of section Stuntzii for Mexico

Psilocybe meridionalis is described as a new species from an oak-pine subtropical forest in the western mountains of the state of Jalisco, Mexico, Because of its bluing feature, annulus and subrhomboid basidiospores, this species belongs to section Stuntzii. The smaller spores and presence of pleurocystidia distinguish this species from the others in the section. This is the first record of a member of section Stuntzii from Mexico

Two glucosylated abscisic acid derivates from avocado seeds (Persea americana Mill. Lauraceae cv. Hass)

Phytochemical investigation of avocado seed material (Persea americana Mill., Lauraceae) resulted in the isolation of two glucosylated abscisic acid derivates. One of these was not known as a natural product and can be regarded as a potential 'missing link' in abscisic acid metabolism in plants. After fractionation by high-speed countercurrent chromatography, and multiple steps of column chromatography, structures were elucidated by 1D-, 2D-NMR, electrospray-MS to be the novel β-D-glucoside of (1′S,6′R)- 8′-hydroxyabscisic acid, and (1′R,3′R,5′R,8′S)- epi-dihydrophaseic acid β-D-glucoside. Absolute configuration was determined by circulardichroism, optical rotation, and by NOE experiments. © 2003 Elsevier Ltd. All rights reserved