Antibiotic resistance and multidrug-resistant efflux pumps expression in lactic acid bacteria isolated from pozol, a nonalcoholic Mayan maize fermented beverage.

Pozol is a handcrafted nonalcoholic Mayan beverage produced by the spontaneous fermentation of maize dough by lactic acid bacteria. Lactic acid bacteria (LAB) are carriers of chromosomal encoded multidrug-resistant efflux pumps genes that can be transferred to pathogens and/or confer resistance to compounds released during the fermentation process causing food spoiling. The aim of this study was to evaluate the antibiotic sensibility and the transcriptional expression of ABC-type efflux pumps in LAB isolated from pozol that contributes to multidrug resistance.

X-ray crystal structure of the passenger domain of plasmid encoded toxin(Pet), an autotransporter enterotoxin from enteroaggregative Escherichia coli (EAEC).

Autotransporters (ATs) represent a superfamily of proteins produced by a variety of pathogenic bacteria, which include the pathogenic groups of Escherichia coli (E. coli) associated with gastrointestinal and urinary tract infections. We present the first X-ray structure of the passenger domain from the Plasmid-encoded toxin (Pet) a 100 kDa protein at 2.

Carbenoxolone gastroprotective mechanism: participation of nitric oxide/(c) GMP/K(ATP) pathway in ethanol-induced gastric injury in the rat.

Carbenoxolone, a semi-synthetic triterpenoid, exhibits gastroprotective activity related to the participation of nitric oxide (NO); however, the complete NO/(c) GMP/K(ATP) channels pathway for carbenoxolone is unknown. Therefore the aim of this study was to examine the NO/(c) GMP/K(ATP) channels pathway as the gastroprotective mechanism of carbenoxolone in the ethanol-induced gastric injury model in the rat. Oral administration of carbenoxolone (30 mg/kg, p.

Mechanisms of relaxant action of a crude hexane extract of Gnaphalium liebmannii in guinea pig tracheal smooth muscle.

We investigated the mechanisms of action of Gnaphalium liebmannii which is used as a folk medicine in México for treating various respiratory diseases such as gripe, fever, asthma, cough, cold, bronchitis, expectorating, and bronchial affections. The tension changes of guinea pig tracheal segments were isometrically recorder on a polygraph. Hexane extract of Gnaphalium liebmannii was the most active relaxant extract (IC(30)=54.

Gastroprotection and effect of the simultaneous administration of Cuachalalate (Amphipterygium adstringens) on the pharmacokinetics and anti-inflammatory activity of diclofenac in rats.

This work aimed to study the effect of Cuachalalate methanol extract (CME) on the anti-inflammatory activity and pharmacokinetics of diclofenac sodium, a frequently prescribed non-steroidal anti-inflammatory drug (NSAID). The gastroprotective effect of CME on the gastric injury induced by diclofenac was studied in rats. CME showed a gastroprotective effect of 15.

Gastroprotective effect of Astragaloside IV: role of prostaglandins, sulfhydryls and nitric oxide.

This investigation evaluated the gastroprotective activity of Astragaloside IV, a cycloartane-type triterpene glycoside isolated from Astragalus zahlbruckneri. Gastric mucosal damage was induced in rats by intragastric ethanol (1 mL/rat). Rats treated orally with Astragaloside IV suspended in Tween 80 at 3, 10 and 30 mg kg(-1), showed 15, 37 and 52% gastroprotection, respectively.

Isobolographic analysis of the sedative interaction between six central nervous system depressant drugs and Valeriana edulis hydroalcoholic extract in mice.

It has been declared frequently that valerian may potentiate the effect of other central nervous system (CNS) depressant drugs, however there has been a lack of experimental data. We have evaluated the profile of the interactions between the ethanol extract of Valeriana edulis spp procera and six CNS depressant drugs using an exploratory model to test the sedative effect in mice. All the compounds tested showed a dose-dependent sedative effect with the following ED50 values: valerian 181.

Neuropharmacological profile of hydroalcohol extract of Valeriana edulis ssp. procera roots in mice.

Valerian is the common name given to the crude drug consisting of the underground organs of the species Valeriana. Valeriana edulis ssp. procera Meyer is the Mexican valerian.

The history of science and the introduction of plant genetics in Mexico.

The emergence and development of 'national sciences' in Latin American countries were not, until very recently, part of the agenda of historians of science because the 'traditional' history of sciences was not interested in the scientific activity of peripheral areas. The history of science is a recent discipline in Mexican historiographic studies. The methodological interest in the history of science, the creation of schools and institutes that deal with it, the establishment of particular chairs, the organization of national societies, and the publication of books and periodicals are all very recent.

Plant-growth inhibitory activity of cedrelanolide from Cedrela salvadorensis.

The effect of cedrelanolide, the most abundant limonoid isolated from Cedrela salvadorensis (Meliaceae), was assayed as a plant-growth inhibitory compound against monocotyledonous and dicotyledonous seeds. This compound inhibited germination, seed respiration, and seedling dry weights of some plant species (Lolium multiflorum, var. Hercules, Triticum vulgare, var.

Oxidative transformations of guaia-1(10)-en-12,8-olides into xanthanolides.

Dihydropsuedoivalin (1) was isolated from Stevia tomentosa, which, when treated with base, afforded epidihydropseudoivalin (2). The stereochemistry of 1 and 2 was established by crystallographic X-ray studies of the two derivatives of epidihydropseudoivalin. Treatment of 1 and 2 with Jones's reagent afforded the xanthanolides 3 and 4, respectively.