Quimioprevención de cáncer y déficit de selenio ambiental / Cancer chemoprevention and selenium

El Selenio (Se) es un oligoelemento esencial en la biología humana, que ha tenido un rol protagónico en los estudios de quimioprevención de cáncer los últimos 20 años. En este artículo se discute la evidencia que ha ligado a este oligoelemento con la reducción de la incidencia y mortalidad por cáncer, especialmente en lo que dice relación con el nivel plasmático de Se en las poblaciones suplementadas. Se presenta también el caso particular de la Provincia de Osorno, en la Décima Región de Chile, que presenta un severo déficit ambiental de este oligoelemento debido a sus particulares características orográficas y se analiza su posible relación con la alta mortalidad por cáncer que presenta la provincia.

Injury surveillance in Trinidad: an accident and emergency based injury surveillance system at the San Fernando General Hospital / Vigilancia de las lesiones en Trinidad: un sistema de vigilancia de lesiones basado en emergencias y accidentes en el Hospital General San Fernando

OBJETIVE: Injuries are a significant cause of morbidity and mortality worldwide. Injuries disproportionately affect people living in low and middle income countries, including the Caribbean; however, little is known about the epidemiology of injuries in these areas. An Accident and Emergency (A&E) Department injury surveillance system was established at the San Fernando General Hospital, Trinidad and Tobago, to address this important data gap. METHODS: A detailed overview of the objectives, data collection methods, and inherent strengths and limitations of this surveillance system are presented, along with results of an analysis of data collected during the first three years of operations (from 2002 to 2004). RESULTS: Trained hospital staff collect a variety of injury/poisoning, demographic and clinical data on nearly 20 000 patients presenting each year with injury to the A&E Department. The total number of injuries in men was almost twice that in women. The majority of injuries were seen in those 25-44-years of age. Falls, other blunt force, stab/cut, traffic injury and poisoning represented the leading causes of injury. Nearly half of all the injuries occurred in the home, with the street/highway and work environments also accounting for an appreciable number of injuries. The majority of injuries were reported as unintentional. CONCLUSION: Injuries represent an important population health and health services issue in South Trinidad. Data from the A&E Department injury surveillance system represent an important resource to inform evidence-based health policy decisions on injury prevention and public health resource allocation.

OBJETIVO: Las lesiones son una causa significativa de morbilidad y mortalidad a nivel mundial. Las lesiones afectan de manera desproporcionada a la gente que vive en países de ingresos bajos y medios, incluyendo el Caribe. Sin embargo, poco se sabe acerca de la epidemiología de las lesiones en estas áreas. Con el propósito de cubrir esta laguna de importantes datos epidemiológicos, se estableció un sistema de vigilancia de lesiones en forma de Departamento de Accidentes y Emergencias (A&E), en el Hospital General San Fernando, en Trinidad y Tobago. MÉTODOS: Se presenta un resumen detallado de los objetivos, métodos de recopilación de datos, así como las fortalezas y limitaciones inherentes de este sistema de vigilancia, junto con los resultados de un análisis de los datos recogidos durante los primeros tres años de operaciones (desde 2002 al 2004). RESULTADOS: Personal entrenado del hospital recogió una variedad de datos de lesiones/ envenenamientos, así como datos demográficos y clínicos de casi 20000 pacientes que acudían con lesiones cada año al Departamento de A&E. El número total de lesiones en los hombres fue casi el doble que en las mujeres. La mayoría de las lesiones se veían en personas de 25 a 44 años de edad. Caídas, golpes contundentes, cortadas/cuchilladas, lesiones por accidentes de tráfico y envenenamiento, representan las principales causas de lesión. Casi la mitad de todas las lesiones ocurrieron en los hogares, seguidas de las producidas en la calle/autopista y los ambientes laborales, también responsables de un número apreciable de lesiones. La mayor parte de las lesiones fueron reportadas como no intencionales. CONCLUSIÓN: Las lesiones representan un asunto importante para los servicios de salud y la salud de la población del sur de Trinidad. Los datos del sistema de vigilancia de lesiones del Departamento de A&E, representan un importante recurso informativo para las decisiones sobre políticas de salud basadas en evidencias a la hora de asignar recursos para la salud pública y la prevención de lesiones.

The projection of GABAergic neurons of the medial terminal accessory optic nucleus to the pretectum in the rat

Large numbers of neurons were retrogradely labeled in both the dorsal and ventral medial terminal nucleous (MTN) after fluoro-gold injections into the rat pretectal nucleus of the optic tract/dorsal terminal nucleus (NOT/DTN). Fluorescence immunocytochemistry for GABA in the same brains revealed GABA-positive neurons distributed mainly in the dorsal MTN. Approximately half of all the GABAergic neurons in the MTN were double-labeled. Therefore, GABAergic neurons comprise a significant component of the MTN-NOT-DTN projection which most likely inhibits the pretectal pathway mediating horizontal optokinetic nystagmus

The development of the retinal projection to the olivary pretectal nucleus in normal and monocularly enucleated hamsters

The projection to the olivary pretectal nucleus (OPN) from the contralateral eyes is observed on the first day after birth and appears adult-like on postnatal day 5. The ipsilaeral projection is present at postnatal day 4, and expands to fill the nucleous overlapping the contralateral projection, though never as dense, between days 6 and 8. Then, in normal hamsters, ipsilaterally projecting fibers retract to the ventral side of the OPN by day 10. However, the dense expanded projection in the dorsal OPN ipsilateral to the remaining eye in monocularly enucleated hamsters persists adulthood

Ganglion cell size and distribution in the retina of the two-toed sloth (Choloepus didactylus L.)

The distribution of ganglion cell densities and sizes was studied in Nissl-stained flat-mount retinae fo the two-toed sloth. The area centrailis, a weak specializtion with low ganglion cell density, is located in the temporal retina close to the center of the eye. The presence of a visual treak was nsoted. The distribution of different ganglion cell sizes was approximately equal throughout the retina. Although the retinal organization differs from that of the closely related three-toed sloth, presumed function of retinl specializations in both species is to guide limb movements by permiting visualization of the branch along which the animal is climbing

Under-reporting of tetanus and diphtheria: cases in Jamaica 1980-1986

A survey of tetanus and diphtheria cases admitted to nine hospitals in Jamaica between 1980 and 1986 was carried out. When compared with notifications to the Ministry of Health over same period, it was found that 117 out of 172 tetanus adminssions (68%) and nine of 72 diphtheria admissions (12.5%) were not reported. There were 11 cases of neonatal tetanus while over half of all tetanus cases were in adultsm 20 years of age or over with twice as many as females (99:45) Forty-one of the diphtheria case (57%) werte aged 1-3 years. The study reveals a high level of under-reporting especially of tetanus. There is a need for tetanus toxoid boosters every 10 years. The importance of reporting notifiable diseases is stressed

Unusual distribution of ganglion cells in the retina of the three-toed sloth (Bradypus variegatus)

1. The distribution ans size of retinal ganglion cells labelled with horseradish preoxidase (HRP) were studied in flat-mounted retinas of three-toed sloths. 2. Massive injections of HRP solution were made throughout the thalamus and midbrain in anesthetized sloths in order to retrogradely label the retinal ganglion cell population. Twenty to thirty h later the eyes were and the retinas flat-mounted and reacted with phenylenediamine-HCL and H2O2 to label ganglion cells,thus distinguishing then from other cells int he same retinal layer. 3. Ganglion cell density graually increased from about 500 cell/mm2 at the far periphery to a peak of about 1,500 cells/mm2 in an area, termed the area centralis, deep in the inferior temporal retina. The presence of a vertical visual steak was also noted. 4. The area centralis contained a higher frequency of small ganglion cells than the peripheral retina where large cells preominated. 5. /the unusual postion of the area centralis and cisual streak in the retina can be explained by the slot's unique ability to rotate its head 180- while climbing upside-dow along horizontal branches so that the head is right-side-up. If it is assumed that the branch directly above the sloth's head needs to be visualized for accurate claw placement then the branch would be imaged on the inferior temporal retina in an area corresponding to the maximum density region

The interception process in tropical rain forests: a literature review and critique (*)

A review of the literature on measurements of rain water interception processes by forests is made. Information on Africa, Central and South America, and Asia is given. A general analysis is made and the need to further the measurements under field conditions is stressed.

É feita uma revisão de literatura sobre medidas de processos de intercepção água da chuva por florestas. São apresentadas informações da África, da América Central e do Sul, e da Ásia. É feita uma análise geral e são mostradas as necessidades de aprofundamento de medidas em condição de campo.

Biomedical survey in North Samar Province, Philippine Islands.

A biomedical survey was carried out in North Samar Province, Philipines to update information on the prevalence of parasitic and other infectious diseases. A total of 1,394 stool specimens, 1,859 blood smears and 1,274 sera were collected from persons living in 8 barrios. Stools were examined for intestinal parasites, bloods smears for malaria and filariasis and sera tested for antibodies to Schistosoma japonicum, Entamoeba histolytica, Toxoplasma gondii, influenza A and B, and Japanese encephalitis virus. The prevalence rates for intestinal parasites were: Trichuris trichiura 90%, Ascaris lumbricoides 78%, hookworm 65%, Schistosoma japonicum 15%, Strongyloides stercoralis 1%, Entamoeba coli 16%, Endolimax nana 6%, entamoeba histolytica 5%, Giardia lamblia 3%, Entaemoeba hartmanii 1%, Chilomastix mesnili 1%. No malaria was found but microfilariae of Wuchereria bancrofti were detected in 4% of the blood smears; the MfD50 was 12.9. The circumoval precipitin test (COPT) was used to detect antibodies to Schistosoma japonicum and 65% of 994 sera was considered positive. The indirect hemagglutination test (IHA) was used for detecting antibodies to Entamoeba histolytica and Toxoplasma gondii and 5% and 3% of 1,274 sera tested were positive at titers equal to or greater than 1:128 and 1:256, respectively. Hemagglutination inhibition tests (HI) were used to detect antibodies to Influenza A2HK68, Influenza A2HK68, Influenza B2T62 and Japanese encephalitis virus and 72%, 12% and 78%, respectively, of 1201 sera were considered positive at titers equal to or greater than 1:20.