Electrophysiological properties of rat nodose ganglion neurons co-transplanted with carotid bodies into the chick chorioallantoic membrane

The electrophysiological properties of nodose ganglion neurons were evaluated immediately after removing nodose ganglia from young adult rats and 3 to 10 days after nodose ganglia implantation _either alone or co-implanted with carotid bodies_ onto the chick chorioallantoic membrane. Implanted and co-implanted nodose neurons were less excitable than acutely recorded nodose neurons. Co-implanted neurons also showed reduced amplitudes for both action potentials and spike after-hyperpolarizations relative to those found in acutely recorded nodose ganglion neurons and a smaller time constant (τ) than that found in implanted neurons. In addition, no spontaneous activity was recorded from nodose ganglion neurons co-implanted with carotid bodies during 3-9 days, which suggests that functional synapses between carotid glomus cells and nodose neurons were not yet established. Results indicate the feasibility of obtaining viable nodose neurons for up to 10 days grafted onto the chick chorioallantoic membrane, where they can conserve most of their passive and active membrane properties and also are susceptible to carotid bodies trophic influences. They also suggest that nodose neurons would need more time for the development of functional synapses when grafted with carotid body glomus cells

The acetyl xylan esterase II gene from Penicillium purpurogenum is differentially expressed in several carbon sources, and tightly regulated by pH

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000100011&lng=es&nrm=isoThe expression of the acetyl xylan esterase II (axeII) gene from Penicillium purpurogenum is repressed by glucose and induced by xylan, as well as to a small degree by xylose and xylitol. This gene is expressed at neutral pH, but not under alkaline or acidic conditions, in agreement with previous findings for other xylanolytic genes of this organism. This is the first report showing pH regulation of an axe gene

National Prevalence and Trends of HIV Transmitted Drug Resistance in Mexico

BACKGROUND: Transmitted drug resistance (TDR) remains an important concern for the management of HIV infection, especially in countries that have recently scaled-up antiretroviral treatment (ART) access. METHODOLOGY/PRINCIPAL FINDINGS: We designed a study to assess HIV diversity and transmitted drug resistance (TDR) prevalence and trends in Mexico. 1655 ART-naïve patients from 12 Mexican states were enrolled from 2005 to 2010. TDR was assessed from plasma HIV pol sequences using Stanford scores and the WHO TDR surveillance mutation list. TDR prevalence fluctuations over back-projected dates of infection were tested. HIV subtype B was highly prevalent in Mexico (99.9%). TDR prevalence (Stanford score>15) in the country for the study period was 7.4% (95% CI, 6.2∶8.8) and 6.8% (95% CI, 5.7∶8.2) based on the WHO TDR surveillance mutation list. NRTI TDR was the highest (4.2%), followed by NNRTI (2.5%) and PI (1.7%) TDR. Increasing trends for NNRTI (p = 0.0456) and PI (p = 0.0061) major TDR mutations were observed at the national level. Clustering of viruses containing minor TDR mutations was observed with some apparent transmission pairs and geographical effects. CONCLUSIONS: TDR prevalence in Mexico remains at the intermediate level and is slightly lower than that observed in industrialized countries. Whether regional variations in TDR trends are associated with differences in antiretroviral drug usage/ART efficacy or with local features of viral evolution remains to be further addressed

Precedentes y conexiones de la revolución chilena de 1810

La emancipación representa en los pueblos hispanoamericanos un proceso simultáneo y de indudables conexiones. Su alcance continental acusa orígenes comunes y dentro de la unidad presenta tonalidades varias en los diversos sitios donde se manifiesta. El análisis que se intentará, en seguida, de los precedentes de la revolución en Chile, junto con subrayar los particularismos, mantendrá a la vista el carácter amplio del movimiento y sus claros contactos

Precedentes y conexiones de la revolución chilena de 1810

La emancipación representa en los pueblos hispanoamericanos un proceso simultáneo y de indudables conexiones. Su alcance continental acusa orígenes comunes y dentro de la unidad presenta tonalidades varias en los diversos sitios donde se manifiesta. El análisis que se intentará, en seguida, de los precedentes de la revolución en Chile, junto con subrayar los particularismos, mantendrá a la vista el carácter amplio del movimiento y sus claros contactos