REGULACION E IMPLICACIONES DE LOS BIFENILOS POLICLORADOS

Los bifenilos policlorados (BPC's) se han utilizado desde los años treinta como líquidos aislantes y refrigerantes en transformadores y capacitores por sus cualidades químicas. En general, los BPC's son compuestos organoclorados que conforman una amplia gama de sustancias, desde líquidos aceitosos, hasta sólidos blanco cristalinos y resinas duras. Se reconocen posibles riesgos generados por la exposición a los BPC's y que atañen a daños al sistema nervioso, lesiones hepáticas, deficiencias del sistema enzimático y perjuicios en el sistema reproductivo de adultos.Se sabe que aproximadamente el 25% de los BPC's asimilados por el ser humano ingresa al organismo por inhalación y el 75% restante a través de productos alimenticios, siendo los de origen animal la fuente principal; donde el pescado aporta entre el 4-5%. En general, los efectos toxicológicos de los BPC's en el ser humano aún no se reconocen en toda su magnitudPalabras clave. Bifenilos policlorados, daños, salud ambiental, control     polychloro bifenilos, damages, health environment, contro

DIVERSIDAD GENÉTICA DEL VIRUS DE INMUNODEFICIENCIA

El Síndrome de Inmunodeficiencia Adquirida (SIDA), es considerado como una pandemia que al igual que otras enfermedades requiere del diagnóstico, vigilancia y tratamiento efectivos. En México como en el resto de los países del mundo, el SIDA es considerado como un serio problema de salud pública, ya que a pesar de todos los esfuerzos que se han hecho para difundir los conocimientos de los aspectos epidemiológicos, de diagnóstico, tratamiento y prevención, el número de casos reales es mayor que el informado por las autoridades; por lo tanto, las consecuencias socioeconómicas son mucho más graves. El VIH-1, es un virus que experimenta una alta variación genética, ésta, causa cambios en el tropismo, virulencia y transmisión de la infección. Nuevas variantes y/o subtipos del VIH-1 se encuentran circulando con un amplio rango de propiedades de virulencia y transmisión que están surgiendo y dispersándose alrededor del mundo en una forma alarmante. El VIH-1 predominante en México es el subtipo B, pero esto no excluye la presencia de otros subtipos en el país, como es la presencia del Subtipo C detectado en un individuo sudafricano. Una adecuada vigilancia epidemiológica del VIH/SIDA incluyendo la identificación, caracterización y análisis de los subtipos predominantes en nuestro país deben ser llevadas a cabo en un esfuerzo para evaluar su diversidad genética y comprender mejor la problemática sobre su diseminación, definir los patrones de distribución geográfica, su epidemiología, sobre el desarrollo de antivirales y sobre todo el diseño de vacunas.Palabras clave: SIDA, VIH, subtipos y formas recombinantes circulantes (FRC).        AIDS, HIV, subtypes and Circulating Recombinant Forms(CRF

Identification and susceptibility of clinical isolates of Candida spp. to killer toxins

Abstract Although invasive infections and mortality caused by Candida species are increasing among compromised patients, resistance to common antifungal agents is also an increasing problem. We analyzed 60 yeasts isolated from patients with invasive candidiasis using a PCR/RFLP strategy based on the internal transcribed spacer (ITS2) region to identify different Candida pathogenic species. PCR analysis was performed from genomic DNA with a primer pair of the ITS2-5.8S rDNA region. PCR-positive samples were characterized by RFLP. Restriction resulted in 23 isolates identified as C. albicans using AlwI, 24 isolates as C. parapsilosis using RsaI, and 13 as C. tropicalis using XmaI. Then, a group of all isolates were evaluated for their susceptibility to a panel of previously described killer yeasts, resulting in 75% being susceptible to at least one killer yeast while the remaining were not inhibited by any strain. C. albicans was the most susceptible group while C. tropicalis had the fewest inhibitions. No species-specific pattern of inhibition was obtained with this panel of killer yeasts. Metschnikowia pulcherrima, Pichia kluyveri and Wickerhamomyces anomalus were the strains that inhibited the most isolates of Candida spp

The complete genome sequence of the \u3ci\u3eArabidopsis\u3c/i\u3e and tomato pathogen \u3ci\u3ePseudomonas syringae\u3c/i\u3e pv. \u3ci\u3etomato\u3c/i\u3e DC3000

We report the complete genome sequence of the model bacterial pathogen Pseudomonas syringae pathovar tomato DC3000 (DC3000), which is pathogenic on tomato and Arabidopsis thaliana. The DC3000 genome (6.5 megabases) contains a circular chromosome and two plasmids, which collectively encode 5,763 ORFs. We identified 298 established and putative virulence genes, including several clusters of genes encoding 31 confirmed and 19 predicted type III secretion system effector proteins. Many of the virulence genes were members of paralogous families and also were proximal to mobile elements, which collectively comprise7%of the DC3000 genome. The bacterium possesses a large repertoire of transporters for the acquisition of nutrients, particularly sugars, as well as genes implicated in attachment to plant surfaces. Over 12% of the genes are dedicated to regulation, which may reflect the need for rapid adaptation to the diverse environments encountered during epiphytic growth and pathogenesis. Comparative analyses confirmed a high degree of similarity with two sequenced pseudomonads, Pseudomonas putida and Pseudomonas aeruginosa, yet revealed 1,159 genes unique to DC3000, of which 811 lack a known function. Includes published article and additional supporting materials

Mitochondrial bioenergetics boost macrophage activation, promoting liver regeneration in metabolically compromised animals

17 páginas, 6 figurasBackground and aims: Hepatic ischemia-reperfusion injury (IRI) is the leading cause of early posttransplantation organ failure as mitochondrial respiration and ATP production are affected. A shortage of donors has extended liver donor criteria, including aged or steatotic livers, which are more susceptible to IRI. Given the lack of an effective treatment and the extensive transplantation waitlist, we aimed at characterizing the effects of an accelerated mitochondrial activity by silencing methylation-controlled J protein (MCJ) in three preclinical models of IRI and liver regeneration, focusing on metabolically compromised animal models. Approach and results: Wild-type (WT), MCJ knockout (KO), and Mcj silenced WT mice were subjected to 70% partial hepatectomy (Phx), prolonged IRI, and 70% Phx with IRI. Old and young mice with metabolic syndrome were also subjected to these procedures. Expression of MCJ, an endogenous negative regulator of mitochondrial respiration, increases in preclinical models of Phx with or without vascular occlusion and in donor livers. Mice lacking MCJ initiate liver regeneration 12 h faster than WT and show reduced ischemic injury and increased survival. MCJ knockdown enables a mitochondrial adaptation that restores the bioenergetic supply for enhanced regeneration and prevents cell death after IRI. Mechanistically, increased ATP secretion facilitates the early activation of Kupffer cells and production of TNF, IL-6, and heparin-binding EGF, accelerating the priming phase and the progression through G1 /S transition during liver regeneration. Therapeutic silencing of MCJ in 15-month-old mice and in mice fed a high-fat/high-fructose diet for 12 weeks improves mitochondrial respiration, reduces steatosis, and overcomes regenerative limitations. Conclusions: Boosting mitochondrial activity by silencing MCJ could pave the way for a protective approach after major liver resection or IRI, especially in metabolically compromised, IRI-susceptible organs.Peer reviewe

Genotype-phenotype correlations in valosin-containing protein disease: a retrospective muticentre study

Background Valosin-containing protein (VCP) disease, caused by mutations in the VCP gene, results in myopathy, Paget's disease of bone (PBD) and frontotemporal dementia (FTD). Natural history and genotype-phenotype correlation data are limited. This study characterises patients with mutations in VCP gene and investigates genotype-phenotype correlations. Methods Descriptive retrospective international study collecting clinical and genetic data of patients with mutations in the VCP gene. Results Two hundred and fifty-five patients (70.0% males) were included in the study. Mean age was 56.8 +/- 9.6 years and mean age of onset 45.6 +/- 9.3 years. Mean diagnostic delay was 7.7 +/- 6 years. Symmetric lower limb weakness was reported in 50% at onset progressing to generalised muscle weakness. Other common symptoms were ventilatory insufficiency 40.3%, PDB 28.2%, dysautonomia 21.4% and FTD 14.3%. Fifty-seven genetic variants were identified, 18 of these no previously reported. c.464G>A (p.Arg155His) was the most frequent variant, identified in the 28%. Full time wheelchair users accounted for 19.1% with a median time from disease onset to been wheelchair user of 8.5 years. Variant c.463C>T (p.Arg155Cys) showed an earlier onset (37.8 +/- 7.6 year) and a higher frequency of axial and upper limb weakness, scapular winging and cognitive impairment. Forced vital capacity (FVC) below 50% was as risk factor for being full-time wheelchair user, while FVC Conclusion This study expands the knowledge on the phenotypic presentation, natural history, genotype-phenotype correlations and risk factors for disease progression of VCP disease and is useful to improve the care provided to patient with this complex disease.Neurological Motor Disorder