Estudio cariológico de Chrysobalanus icaco (Chrysobalanacea) en Paraíso, Tabasco, México / Caryological study of Chrysobalanus icaco (Chrysobalanacea) in Paraíso, Tabasco, México

Chrysobalanus icaco es una planta que pertenece a la familia Chrysobalanaceae. En Tabasco, Mexico, esta planta se distribuye en los municipios de la costa. La finalidad de esta investigacion fue la caracterizacion cromosomica de dos fenotipos con color de fruto rosa y purpura mediante tincion convencional. Con tal fin, se recolectaron frutos maduros en la comunidad de Penjamo, Paraiso, Tabasco. Las semillas se dejaron germinar por 30 dias a una temperatura constante de 30 °C. Se utilizaron raicillas de 1,00 cm de longitud, las cuales fueron sometidas a hidrolisis acida y posterior tincion con orceina. Se fotografiaron 295 metafases y se midieron los cromosomas de 35 placas metafasicas del fenotipo purpura y 30 del fenotipo rosado. Ambos fenotipos presentaron 18 cromosomas pequenos, los cuales se ordenaron en nueve pares homologos segun su tamano relativo. No se observaron diferencias morfologicas ni numericas entre los cariotipos de ambos fenotipos. Ademas la prueba de t-Student (α=0,05) revelo que no se encuentran diferencias significativas entre los complementos cromosomicos de ambos fenotipos.

Chrysobalanus icaco is a plant that belongs to the Chrysobalanaceae family. In Tabasco, Mexico, this plant is distributed in the municipalities of the coastline. The main purpose of this research was to characterize the chromosomal structure of phenotypes with pink and purple fruits by the use of conventional staining. To this end, mature fruits were collected in the community of Penjamo, Paraiso, Tabasco. Seeds were allowed to germinate for 30 days at a constant temperature of 30° C. Roots of 1.00 cm in length were subjected to acid hydrolysis and subsequent staining with orcein. A total of 295 metaphases were photographed and chromosomes of 35 metaphases of the purple phenotype and 30 of the pink phenotype were measured. Both phenotypes presented 18 small chromosomes, which were ordered in nine homologous pairs according to their relative size. No morphological or numerical differences were observed between the karyotypes of both phenotypes. In addition, the t-Student (α=0.05) test did not reveal significant differences between the chromosomes complements of both phenotypes.

Larval development of the symbiotic pea crab Pinnaxodes chilensis (H. Milne Edwards, 1837) (Decapoda, Brachyura, Pinnotheridae) reared in laboratory.

The complete larval development of Pinnaxodes chilensis (including four zoeal stages and a megalopa stage) is described and illustrated in detail for the first time. The descriptions are based on laboratory-reared larvae obtained from ovigerous females found inside specimens of the sea urchin Loxechinus albus collected in the coast of Valparaíso, Chile. In order to allow the correct differentiation of specimens from plankton samples, the larval stages of P. chilensis are compared with those from other Pinnotheridae species, whose larval development is known for the Chilean continental waters (Calyptraeotheres politus). The morphological characters described for P. chilensis larvae, as well as the comparison with the remaining larval development descriptions available for the genus Pinnaxodes, are used to discuss the heterogeneity within this genus.

Absolute and relative predictor values of some non-invasive and invasive studies for the outcome of anterior temporal lobectomy.

BACKGROUND: There is controversy in the literature regarding the strategy used to obtain better outcomes after performing an anterior temporal lobectomy (ATL). Some investigators prefer to reduce the risks and costs of the predictor studies despite the fact that the number of patients cured after ATL (no seizures with no medication) is relatively small. Other investigators prefer to attempt a total cure in all patients by using all available predictor studies regardless of risks and costs. The latter strategy was the aim of the present work. METHODS: The absolute (%) and relative (ratio differences) predictor values of non-invasive and invasive studies for the outcome 24 months post-ATL were determined on 22 patients suffering from intractable non-lesional temporal lobe epilepsy. RESULTS: Under these conditions, 11 (50%) patients had excellent outcomes (seizure-free, no medication), 8 ( 36%), good outcomes (only auras with medication), and 3 (13.6%), poor ou tcomes (1 with >70%-seizure reduction and two no changes in seizure frequency). Predictors of excellent (vs. poor outcome) include the following: complex partial seizures (CXP) alone or associated with secondary generalized tonic-clonic seizures; ictal motionless stare and postictal amnesia; abnormal bitemporal spikes (prominent ipsilateral to ATL) and secondary bilateral synchrony EEG activities; focal hippocampal ictal EEG activities, and the presence of focal anterior temporal delta EEG activity 3 months after ATL. Predictors of poor (vs. excellent) outcomes include the following: CXP associated with other generalized seizure types; CTS, MRI, and EEG extratemporal abnormalities, and generalized basotemporal ictal EEG activities and the presence of seizures and focal anterior temporal spikes 3 months after ATL. CONCLUSIONS: The present study corroborates that no single predictive study (including non-invasive MRI and invasive ictal EEG activity) is predictive of the success or failure of ATL. Rather, a concordant combination of non-invasive and invasive studies is more likely to be predictive of a high probability of success. The high efficiency of ATL (86% of patients seizure-free) was accomplished by using all available predictor studies.

[Perceptions and practices related with tuberculosis and treatment compliance in Chiapas, Mexico]. / Percepciones y prácticas relacionadas con la tuberculosis y la adherencia al tratamiento en Chiapas, México.

OBJECTIVE: To identify health perceptions and practices and non-adherence to therapy among tuberculosis patients. MATERIAL AND METHODS: Qualitative research work consisting of 11 group interviews with 62 tuberculosis patients during 1997-1998 in the Central, Highlands, and Border Regions of Chiapas, Mexico. RESULTS: Perceived causes of tuberculosis included contagion via food utensils, excess work, malnutrition, and cold, as well as other causes unrelated to person-to-person contagion. The resulting incapability to work resulted in an economic crisis for both the patients and their family members. As a result of the social stigma imposed by the disease, patients perceived a negative impact on their personal life, family, work, and community. CONCLUSIONS: Lack of knowledge regarding tuberculosis is an important factor in the selection of and adherence to different care alternatives. Inadequate care provided by health services, including an unsatisfactory physician-patient relationship, resulted in diagnostic delay and non-adherence to therapy. Education programs to promote basic knowledge regarding tuberculosis and its treatment are necessary in this region.

[Some insights on the influence of socioeconomic factors on migratory movements]. / Algunos rasgos sobre la influencia de los aspectos socio-economicos en los movimientos migratorios

PIP: A theoretical approach to the study of migration in Ecuador is presented. Consideration is also given to the relationships among migration, mortality, fertility, and employment and to the policy implications of these relationships.^ieng