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Despite their ability to mitigate climate change by efficiently absorbing atmospheric carbon dioxide (CO2) and acting as natural long-term carbon sinks, mangrove ecosystems have faced several anthropogenic threats over the past century, resulting in a decline in the global mangrove cover. By using standardized methods and the most recent Bayesian tracer mixing models MixSIAR, this study aimed to quantify source contributions, burial rates, and stocks of organic carbon (Corg) and explore their temporal changes (∼100 years) in seven lead-210 dated sediment cores collected from three contrasting Mexican mangrove areas. The spatial variation in Corg burial rates and stocks in these blue carbon ecosystems primarily depended on the influence of local rivers, which controlled Corg sources and fluxes within the mangrove areas. The Corg burial rates in the cores ranged from 66 ± 16 to 400 ± 40 g m-2 yr-1. The Corg stocks ranged from 84.9 ± 0.7 to 255 ± 2 Mg ha-1 at 50 cm depth and from 137 ± 2 to 241 ± 4 Mg ha-1 at 1 m depth. The highest Corg burial rates and stocks were observed in cores from the carbonate platform of Yucatan and in cores with reduced river influence and high mangrove detritus inputs, in contrast to patterns identified from global databases. Over the past century, the rising trends in Corg burial rates and stocks in the study sites were primarily driven by enhanced inputs of fluvial-derived Corg and, in some cores, mangrove-derived Corg. Despite their decreasing extension, mangrove areas remained highly effective producers and sinks of Corg. Ongoing efforts to enhance the global database should continue, including mangrove area characteristics and reliable timescales to facilitate cross-comparison among studies.

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The development of the Grijalva-Usumacinta river basin exerts modifications on its discharge area. A sediment core was studied to reconstruct environmental changes and trace element contamination status during the past 45 years. 210Pb-derived mass accumulation rates indicate higher sediment input to the area since 1995, related to increased precipitation and floodings in the catchment area. Sediments show finer particles from the late 1970s on, likely related to dams construction upriver and/or land use changes. Heavy metal enrichment factors (EF < 2) suggest minimum contamination. Benthic foraminifera and redox-sensitive - elements (As, Ba, Co, Cr, Cu, Ni, Pb, V and Zn) indicate the sediments before 2000 were deposited under oxygenated conditions. Afterwards, environmental conditions changed and benthic foraminifera and dinocysts assemblages changed suggesting eutrophication and lower oxygen conditions during the last 20 years. Monitoring should be continued to assess eutrophication/hypoxic/pollution trends that could become deleterious to the marine biota.

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Spatial and temporal variability of mercury concentrations in sediments was evaluated in 210Pb-dated sediment cores from offshore and intertidal areas in the southern Gulf of Mexico. In offshore cores, mercury concentrations were comparable (11.2-69.2 ng g-1), and intermediate between concentrations in intertidal cores from the eastern (6.0-34.4 ng g-1) and the western (34.9-137.7 ng g-1) inlets of Términos Lagoon. The enrichment factor (EF) indicated minimal contamination (EF < 2) in most offshore cores, whereas in some intertidal cores steadily increasing mercury enrichment and fluxes were observed along the past century. No evidence of oil industry related mercury contamination was found, as the minor but increasing enrichment in intertidal cores is most likely related to land-derived sources such as catchment eroded soils and waste water runoff. Results highlight the importance to control catchment erosion and untreated sewage releases to reduce mercury loadings to the coastal zone.

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The Campeche Sound is the major offshore oil producing area in the Southern Gulf of Mexico (SGoM). To evaluate the impact of oil related activities in the ocean floor sediments, we analyzed the geochemical (major and trace element, organic carbon and hydrocarbon concentrations) and biological (benthic foraminifera) composition of 62 superficial sediment samples, from 13 to 1336 m water depth. Cluster and Factor analysis of all the variables indicate that their distribution patterns are mainly controlled by differences between the terrigenous and carbonate platforms in the SGoM. Benthic foraminiferal assemblages were abundant and diverse, and their distribution patterns are mainly determined by water depth and sedimentary environment. However, most of the abundant species are opportunistic and/or low-oxygen tolerant, and many of their tests show oil stains and infillings, characteristic of oil polluted locations, suggesting the environment has been modified by natural seepage or oil-related activities. To determine if these conditions are natural or anthropogenic in origin, pre - industrial settings should be studied. Organic carbon (Corg) content (0.6-2.9%) and total hydrocarbon concentrations (PAHs 1.0-29.5 µg kg-1) were usually higher around the oil platforms area, the natural hydrocarbon seeps ("chapopoteras") area and offshore rivers, but there is no accumulation of oil related trace elements in these areas. However, the comparison with international sediment quality benchmarks indicates that Cd, Cr and Ni concentrations are above the threshold effect level, and also As, Ba and Cu are above the probable effect level benchmarks, which indicate that these element concentrations might be of potential ecological concern. Comprehensive studies involving different proxies, and assessing pre-industrial conditions, must be undertaken before assessing environmental health of marine benthic ecosystems.

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Trace element (As, Co, Cr, Cu, Ni, Pb, V and Zn) enrichment trends during the past century, were assessed in thirteen 210Pb-dated sediment cores from the southern Gulf of Mexico, with the purpose to evaluate the impact on the environment, and potentially on public health, of the offshore oil industry and of oil spills such as that of the Ixtoc1 well blowout in 1979. The trace element composition was quite homogeneous among cores; and the pre-industrial concentrations of Ba, Cr, Cu and Ni are naturally high in the region, as to reach levels of potential ecological concern. The influence of multiple and simultaneous processes (e.g. industrial activities, natural seeps, fluvial discharges) on the trace element concentrations is difficult to disentangle. Some cores suggested long-term preservation of putative oil spill traces, although it was not possible to attribute their origin. The Al-normalized redox element ratios, and the crude oil contamination ratio, suggested that these events occurred along almost four decades, and that the traces attributed to the Ixtoc1 spill were comparable to background conditions, most likely owing to active natural oil seeps in the area. In most cases there was a trend towards a lowering in the supply of trace elements; this might be associated with environmental controls in the region since the 1980s. This study highlights the relevance of using dated environmental archives to reconstruct the historical trends of trace metal contamination in areas where long-term environmental studies are scarce.

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Introducción: La torsión del omento mayor en el interior de un orificio herniario es una entidad muy infrecuente como complicación de una hernia. Caso clínico: Presentamos el caso de un paciente varón de 43 años que acude a Urgencias por cuadro de dolor en fosa ilíaca derecha (FID). El estudio mediante tomo-grafía computarizada muestra un patrón "en remolino" en la grasa mesentérica que se introduce en el orificio inguinal derecho, sugerente de hernia complicada secundaria a torsión de omento mayor. Los hallazgos quirúrgicos y anatomopatológicos confirman el diagnóstico. La torsión de omento mayor es una causa poco frecuente de complicación de hernia inguinal.

Background: Secondary torsion of the greater omentum due to a complicated hernia is uncommon. Case report: We report a 43 years old male presented to the emergency room for pain in the right lower quadrant of the abdomen. An abdominal CT scan showed that mesenteric fat was herniating through the right inguinal orifice with a whirling pattern, suggesting a complicated hernia secondary to torsion of the greater omentum. The patient was operated and the preoperative diagnosis was confirmed.

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Modern broilers have been submitted to continuous genetic improvement, and therefore, their nutritional requirements must be constantly updated to ensure their performance. Two experiments were carried out to evaluate different digestible lysine levels for starter (1021 days) and grower (22-35 days) phases. The experiments were carried out with male and female Cobb 500 broilers, distributed according to a randomized block experimental design in a 5x2 factorial arrangement (5 increasing digestible lysine levels x 2 sexes), totaling 10 treatments, with 8 replicates of 22 and 20 birds during the starter and grower phase, respectively. Digestible lysine levels of 1.06, 1.12, 1.18, 1.24, and 1.30 were used in the starter diets (10-21 days) and 0.9, 0.98, 1.04, 1.10, and 1.16% in the grower diets (22-35 days). Based on the statistical analyses of the evaluated performance parameters, digestible lysine requirements for maximum performance were determined as 1.22% for males and 1.24% for females in the starter phase, and 1.16% for both sexes in the grower phase. Carcass and performance results indicate that digestible lysine requirements vary with sex and evaluated production parameter. Considering the most relevant broiler production parameters, in 22- to 35-d-old males, digestible lysine requirement for breast meat yield (1.16%) was higher than those for feed conversion ratio (1.07%) and weight gain (1.05%).(AU)

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The accumulation, enrichment and provenance of selected trace metals (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, V and Zn) were studied in sediment cores collected from three lakes located in the Central Mexican Plateau, selected on the basis of their contrasting degree of urbanization: Santa Elena Lake, in a rural and remote area; El Tule Lake, in a rural and slightly urbanized area; and Chapala Lake, in a highly urbanized area. Grain size, magnetic susceptibility and sedimentary constituents such as organic carbon, calcium carbonate, as well as major (Al, Fe, Mn) and minor (Ca, Li, Rb, Sr, Th) elements were analyzed to explain the concentration trends of trace metals. Factor analysis (FA) was used to assess the provenance of the trace elements. The highest metal enrichment factor (EF) above natural concentration levels was found at Chapala Lake for Ag (EF = 3.9), although other trace element EF in all lakes was <2.0, indicating slight contamination. However, the concentration levels of Cr and Ni in all lakes, Hg and Zn in Chapala Lake, Cu in El Tule Lake and As in Santa Elena Lake were above international benchmarks for which adverse effects are expected to occur frequently, even for those metals only slightly enriched (e.g. As, Cr). Through FA, the terrigenous contribution was identified as the most important source of trace metals to the three lakes, most likely related to deforestation and erosion of the surrounding areas, followed by atmospheric transport of volcanic ashes, rather than to direct sources.

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Genetic relationships between populations can be studied by comparing genotypic and allelic similarities. This investigation aims to demonstrate that selected autosomal microsatellite markers could be used to study the genetic structures of different populations living in northwest Venezuela, in Zulia State. Seven autosomal systems (CSF1PO, TPOX, TH01, vWA, D7S820, D13S317, and D5S818) were tested by PCR in a multiplex format on 688 different chromosomes from unrelated individuals living in Maracaibo, "Isla de Toas," and "San José de Heras," and from two Amerindian populations from the "Sierra de Perijá," Barí' and Yukpa. Allele frequencies, Hardy-Weinberg equilibria, genetic distances, phylogenetic trees, and ethnic admixtures were estimated. The study shows the existence of a clear genetic difference among these populations in accordance with their historic evolution. The populations of Maracaibo and "Isla de Toas" showed a triracial origin, with a large European contribution, followed by an Amerindian component and a small African component. The indigenous groups, Barí' and Yukpa, showed exclusively an Amerindian component, and "San José de Heras" showed only an African component. These results indicate that microsatellite markers are useful for molecular anthropology in a regional and worldwide context and provide important genetic information about contemporary populations of Venezuela.

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In this double-blind, randomized trial, we compared the clinical efficacy of intralesional vinblastine (VNB) and 3% sodium tetradecyl sulfate (STS) in the treatment of oral Kaposi's sarcoma (OKS). Subjects with OKS were randomly assigned to receive a single intralesional injection of either VNB or STS, at a standard dose (0.2 mg/cm(2)). Differences were evaluated by the Mann-Whitney U and Fisher's exact tests. Sixteen HIV-infected patients were included, eight received VNB and eight received STS; clinical response was evaluated at days 7, 14, and 28 following treatment. Tumor size reduction was 0.68 and 0.61 cm in the VNB and STS groups, respectively (P=0.80). Two VNB patients had complete or partial response whereas four STS subjects had partial responses (P=0.61). Patients in both groups experienced minimal toxicity. We conclude that intralesional vinblastine or STS are adequate for the management of OKS. The benefits of STS are its low cost and ease of use.

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Allele frequencies for nine autosomal STRs loci were obtained from individuals from a sample of unrelated individuals born in Venezuela.

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BACKGROUND/PURPOSE: Congenital diaphragmatic hernia (CDH) is one of the most frequent causes of neonatal death because of lung hypoplasia (LH). The literature mentions a relationship between renal and pulmonary development, with higher kidney weight in presence of LH. The aims of this study were to evaluate the relationship between lung and kidney weight and to test the hypothesis of renal enlargement in fetuses and newborns with CDH. METHODS: Body weight (BW), combined kidney weight (KW), and lung weight (LW) of 52 CDH cases were established; 52 morphologically normal fetuses or newborns, matched by BW, served as a control population. Comparisons were done by covariance analysis, and a P value of less than .05 was considered as significant. RESULTS: Excluding renal abnormalities, adjusted mean kidney weights were 22.0 g (+/-1.8 SE) in CDH cases and 20.5 g (+/-1.5 SE) in controls (F = 1.05; P = .308). KW to BW ratio was lower in CDH cases than in controls (P = .023). LW was significantly lower in CDH cases than in controls. CONCLUSIONS: No significant difference between KW of CDH cases and controls could be observed. The current study provides enough evidence to reject the hypothesis of renal enlargement in cases of LH and CDH.

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The D1S80 locus in 122 individuals from Maracaibo, Venezuela, was studied to verify the genetic relationship of this sample with 32 other reported world populations derived from different ethnic groups. All analyses reveal that the Venezuelan sample has a main European genetic contribution, followed by contribution from Amerindians, and a small contribution of Africans. The population of Maracaibo has a high level of heterozygosity, as expected for populations with an important level of recent admixture. Am. J. Hum. Biol. 12:616-622, 2000. Copyright 2000 Wiley-Liss, Inc.

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Non coding DNA of human genome contains an important part of tandem repetitive DNA which last years has been extensively applied to solve paternity disputes and individual identification cases. A class of this DNA are minisatellites and microsatellites loci. Such loci are highly polimorphics because they have a multiple of different alleles to make them ideals genetic markers for these purposes. This article is a review about these loci, methods of their analysis and practical aspects about their applications to determine biological paternity or individual identification in the forensic genetic field are considered.

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BACKGROUND: Cervical cancer is the most important cancer in Mexican women. Early detection is possible by means of the Papanicolaou (Pap) test; however, the coverage in Mexico is low. METHODS: A cross-sectional survey was carried out in a representative sample of women from the Tlalpan area of Mexico City. Social, reproductive and health care factors associated with the lack of use of the Pap test with respect to adequate use and misuse were identified. Both bivariate and logistic regression analyses were used for the adjustment of variables. RESULTS: Of 1,215 women studied, 22.5% had never had a Pap smear, 42% had misused the test (< 90% of triennial performance), and 35.5% had adequately used the test (> or = 90% of triennial performance). The main factors related to the lack of use were the following: not knowing about the Pap test (ORa = 35.16, 95% C.I. = 17.4-70.9); having fewer than 6 years of education (ORa = 4.5, 95% C.I. = 2.5-8.4); women younger than 30 years of age (ORa = 3.4 95% C.I. = 2.3-5.1); use of contraceptives (ORa = 0.4, 95% C.I. = 0.2-0.8); history of sexually transmitted diseases (ORa = 0.3, 95% C.I. = 0.1-0.8), and the principal informant about the Pap test, i.e., the health services personnel (ORa = 0.02, 95% C.I. = 0.0008-0.05). CONCLUSIONS: The lack of use and the misuse of Pap smears vary importantly among the different social and reproductive factors. But the principal reasons for lack of use were not knowing about the Pap test and a low educational level. We propose a greater diffusion on the benefits of the test in the Mexican population, through massive means of communication and health services.

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El objetivo de este trabajo es presentar la reacción de la lesión retiniana posterior a un traumatismo ocular cerrado. Se realizó fluorangiografía utilizando cámara retiniana Topcon 50/IA, cámara digital Kodak Megaplus, sistema de imágenes digitales IMAGEnet, fluoresceína vía oral, verde de indocianina y filtros para diversasa longitudes de onda. Se observó una dilatación franca de los vasos coroideos en el área afectada (ojo derecho, OD) en comparación con el ojo sano (ojo izquierdo, OI) un mes después del traumatismo. Los métodos digitales de exploración del fondo de ojo usando longitudes de onda de 800 nm permiten la observación directa de la coroides, lo que contribuirá al avance en el conocimiento de esta estructura y de su patología

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Con la finalidad de determinar la eficacia, como agentes inhibidores del crecimiento fúngico de saprolegniales en ovas de trucha arcoiris, se procedió a la evaluación de tratamientos con ácido acético (100 ppm, 300ppm y 500ppm), cloruro de sodio (20 porciento) y verde malaquita (2,5 ppm). Los parámetros medios fueron: la mortalidad total de los huevos hasta que éstos presentaron el ojo visible y la deformidad de alevines con saco. Los tratamientos se aplicaron utilizándo la técnica de corte de flujo, efectuada día por medio y con tiempos de 60 minutos de duración. Este procedimiento abarcó desde la fecundación hasta la aparición de los ojos. El verde malaquita, presentó la menor mortalidad total de huevos (12,95 porciento), seguido por el ácido acético a 500 ppm (16,96 porciento). En las ovas muertas con hongos adheridos a su superficie se registró un 6,76 porciento para verde malaquita y un 11,72 porciento para el ácido acético a 500 ppm. Con el cloruro de sodio se obtuvo la mayor proporción en ambos casos. Los huevos tratados con verde de malaquita, registraron una alta incidencia de alevines con saco deformes (13,5 porciento), mientras para los restantes tratamientos, fueron inferiores al 7 porciento. Es posible concluir que el ácido acético en concentraciones de 500 ppm puede ser utilizado como sustituto al verde malaquita para controlar infecciones micóticas en ovas, ya que no produce elevados niveles de mortalidad en los huevos y no induce a la formación de alevines con saco deformes

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