Nutrient dynamics in wetland systems associated with hydrological and anthropogenic variations in the south of Samborombón Bay, Argentina.

Wetlands provide numerous ecosystem services to the environment, such as nutrient removal and storage. The aim of this work is to evaluate the nutrient dynamics in different sectors within wetland systems in the south of the Samborombón Bay (Argentina) based on hydrological and/or anthropogenic variations. For this purpose, the hydrological features of the wetland were defined through the analysis of satellite images, precipitation and tidal data, and field surveys. Three sectors were identified in the wetland: one with tidal influence, another which is dependent on rainfall, and another that receives inputs from rainfall and from a sewage effluent treatment plant. In order to analyze the nutrient dynamics, samples of surface water, groundwater, and sediments were collected from these sectors. Measurements of pH and electrical conductivity were determined in situ in water samples, while the concentration of inorganic forms of phosphorus and nitrogen, soluble reactive silica, and organic carbon were determined through laboratory analysis. Also, bioavailable phosphorus, organic matter, pH, and electrical conductivity were determined in the sediment samples collected. Statistical analysis of the data reveals differences between the sectors and allows the interpretation of the dynamics of the studied components in the wetland. Electrical conductivity distinguishes the intertidal sectors of the wetland while components associated with P and N discriminate the sectors with inputs from the sewage effluent treatment plant. On the other hand, soluble reactive silica, organic carbon, and organic matter do not seem to be influenced by the tide or effluent discharge. This study demonstrates that the studied wetland works as a nutrient retention area, providing ecosystem services to local inhabitants. Although these services can be utilized, they require a continuous monitoring over time to provide an early warning in case the variations in P and N cycles could lead to eutrophication or wetland degradation.

Granuloma anular perforante: patologia inusual / Perforating Granuloma Annulare: unusual pathology

Resumen El Granuloma Anular (GA) es una dermatosis inflamatoria crónica, benigna, auto limitada, de etiología desconocida. Existen numerosas variantes clínicas dentro de las cuales se encuentra la perforante, de presentación inusual. La histopatología más característica de GA, cuenta con la presencia de histiocitos epitelioides en empalizada alrededor de áreas de degeneración focal de fibras de colágeno con depósitos de mucina. La variedad perforante evidencia eliminación transepidérmica de fibras de colágeno. Se presenta un paciente de 72 años de edad, diabético, dislipémico, con lesiones pruriginosas en dorso de ambas manos, con el diagnóstico de granuloma anular perforante. Realizó tratamiento con clobetasol tópico, más antihistamínicos por vía oral, quedando una cicatriz atrófica.

Abstract Granuloma annulare is a chronic, benign, self-limiting, inflammatory dermatosis of unknown etiology. There are numerous clinical variants within which is the perforating, unusual presentation. The most histopathology characteristic of GA is the presence of palisading epithelioid histiocytes around areas of focal degeneration of collagen with mucin deposits. The perforating variety evidences transepidermal elimination of collagen tissue. A 72 years-old, diabetes, dyslipidemic patient is presented with pruritic lessions on the dorsum of both hands, with the diagnosis of perforating granuloma annulare. I perform medical treatment with topical clobetasol, leaving an atrophic scar.

Calcifilaxis / Calciphylaxis

Resumen La calcifilaxis es una enfermedad poco frecuente, aunque presenta una elevada tasa de mortalidad debido sobre todo a complicaciones como sepsis o gangrena. Generalmente se asocia a insuficiencia renal severa. Se define como la calcificación de la capa media de vasos de pequeño y mediano tamaño de la dermis y tejido celular subcutáneo. Clínicamente se manifiesta como un síndrome de livedoracemosa que progresa a púrpura retiforme y necrosis cutánea. La primera línea de tratamiento es el tiosulfato sódico.

Abstract Calciphylaxis is a rare disease, although it has a high mortality rate due mainly to complications such as sepsis or gangrene. It is usually associated with severe renal failure. It is defined as the calcification of the middle layer of small and medium-sized vessels of the dermis and subcutaneous cellular tissue. Clinically it manifests as a livedoracemosa syndrome that progresses to retinal purpura and cutaneous necrosis. The first line of treatment is sodium thiosulfate.

Removal of iron and manganese in groundwater through magnetotactic bacteria.

It is presented an alternative biological method based on biomineralization mechanisms of Magnetotactic Bacteria (MTB) for the removal in groundwater, of soluble elements such as Fe+2and Mn+2. In first place, it was compared the effectiveness of MTB retention methods for obtention of concentrated volumes in microorganisms, then, it was carried out an inoculation process in groundwater samples and evaluate the removal rate of Fe+2 and Mn+2 in constant conditions of pH and temperature. It was identified electromagnetic method is more efficient in MTB retention, and that the inoculation processes of an enriched solution with MTB in groundwater samples allow to get average removal rates of 47.86% for Fe+2 and 15.26% for Mn+2. In addition, it was evaluated the removal rate of other metals due to magnetic properties of biominerals inside of MTB magnetosome. The highest removal in all cases occurred between the interval of 3 and 5 min of interaction and tended to stabilize in time.

Assessment of the Sulfamethoxazole mobility in natural soils and of the risk of contamination of water resources at the catchment scale.

Sulfamethoxazole (SMX) is one of the antibiotics most commonly detected in aquatic and terrestrial environments and is still widely used, especially in low income countries. SMX is assumed to be highly mobile in soils due to its intrinsic molecular properties. Ten soils with contrasting properties and representative of the catchment soil types and land uses were collected throughout the watershed, which undergoes very rapid urban development. SMX displacement experiments were carried out in repacked columns of the 10 soils to explore SMX reactive transfer (mobility and reactivity) in order to assess the contamination risk of water resources in the context of the Bolivian Altiplano. Relevant sorption processes were identified by modelling (HYDRUS-1D) considering different sorption concepts. SMX mobility was best simulated when considering irreversible sorption as well as instantaneous and rate-limited reversible sorption, depending on the soil type. SMX mobility appeared lower in soils located upstream of the watershed (organic and acidic soils - Regosol) in relation with a higher adsorption capacity compared to the soils located downstream (lower organic carbon content - Cambisol). By combining soil column experiments and soil profiles description, this study suggests that SMX can be classified as a moderately to highly mobile compound in the studied watershed, depending principally on soil properties such as pH and OC. Potential risks of surface and groundwater pollution by SMX were thus identified in the lower part of the studied catchment, threatening Lake Titicaca water quality.

Xanthomonas albilineans Haplotype B Responsible for a Recent Sugarcane Leaf Scald Disease Outbreak in Cuba.

Over the past 3 years, the incidence of sugarcane leaf scald disease (LSD) caused by Xanthomonas albilineans has increased at alarming rates in some Caribbean countries. LSD was in latent phase since 1978, when the disease was reported in Cuba, until February 1998 when typical symptoms were observed in germ plasm collections and in some commercial plantings. More than 150 bacterial isolates from different sugarcane varieties and from different localities were isolated on Wilbrink agar medium and characterized. All isolates had shown similar cultural and biochemical patterns. However, serological differences between isolates from the recent outbreak and the ones obtained prior to 1998 were detected by indirect ELISA testing. Differences between Cuban isolates obtained prior to 1998 and those from the recent outbreak were confirmed by analysis of repetitive DNA sequences dispersed throughout the genome. According to the pattern obtained, the newer isolates were similar to reference strains classified as haplotype B by pulsed field gel electrophoresis (1). It is concluded that the recent outbreak of LSD was caused by a strain different than the ones previously detected in Cuba. Reference: (1) M. J. Davis et al. Phytopathology 87:316, 1997.

Analysis of the distribution of HLA-A alleles in populations from five continents.

The variation and frequency of HLA-A genotypes were established by PCR-SSOP typing in diverse geographically distributed populations: Brazilian, Colombian Kogui, Cuban, Mexican, Omani, Singapore Chinese, and South African Zulu. HLA-A allelic families with only one allele were identified for HLA-A*01, -A*23, -A*25, -A*31, -A*32, -A*36, -A*43, -A*69, -A*80; and with two alleles for HLA-A*03, -A*11, -A*26, -A*29, -A*33, -A*34, and -A*66. Greater variation was detected for HLA-A*02, -A*24, and -A*68 allele families. Colombian Kogui and Mexican Seris showed the least diversity with respect to HLA-A alleles, albeit with small numbers tested, with only four and five HLA-A alleles identified, respectively. It would appear by their presence in all populations studied, either rural or indigenous, that certain alleles are very important in pathogen peptide presentation.

Enfermedad de Buerger: características clinicopatológicas y tratamiento en 23 pacientes / Buerger's disease: clilicopathological features and treatment in a group of 23 patients

Se realizó un estudio descriptivo retrospectivo de los signos, sintomas, exámenes diagnosticos, hallazgos patologicos y tratamiento, y su relacion con el tiempo de consulta en el Hospital Universitario San Vicente de Paul, de los pacientes con diagnostico histopatologico de enfermedad de Buerger, durante el periodo comprendido entre enero de 1985 y diciembre de 1995. Se busco la tasa de confirmacion diagnostica del examen anatomopatologico al igual que la presencia de los hallazgos histológicos clasicos en las placas microscopicas. Se encontro una frecuencia de presentacion de 0.04 por ciento y un promedio de edad al consultar de 32.3 años con predominio del sexo masculino (95.7 por ciento). La incidencia de tabaquismo fue del 100 por ciento. Se encontro relacion estadisticamente significativa entre el tiempo de fumador y el tiempo de evolucion de la enfermedad con el numero de amputaciones. Los hallazgos patologicos fueron confirmatorios de la enfermedad en el 69.6 por ciento de los casos, siendo escasa la presentacion de los signos histologicos clasicos. Se realizaron amputaciones en el 95.7 por ciento de los pacientes. Se concluyo que la manera de presentacion de la enfermedad de Buerger en nuestro medio es diferente a lo reportado en la literatura mundial; que el diagnostico es eminentemente clinico; que el numero de amputaciones es dependiente del tiempo de fumador y del tiempo de evolucion, y que la amputacion es el tratamiento más comun. Debe hacerse una busqueda más enfática de las muestras representativas en los especimenes enviados a patologia, al igual que un estudio histologico más minucioso de las muestras.

[Systemic-psychodynamic model for family evaluation]. / Modelo psicodinámico-sistémico de evaluación familiar.

In this paper a family evaluation instrument called systemic-psychodynamic family evaluation model is described. Also, the second stage of the validation study of this instrument is presented (which deals with the inter-observers variation). Twenty families were studied. They were assessed always by the same interviewers designated as experts. They are all family therapy specialists and their assessment was used as the evaluation reference standard or "gold standard". The observers were psychiatrists without previous training in family therapy. For the purpose of the interview, both experts and observers were blind to the medical diagnosis of the patients. During the first stage of the validation study the observers did not have a reference guide which resulted in a low concordance rating. For the second stage, a 177 item guide was used and a considerable increase in the concordance rating was observed. Validation studies like the one used here are of considerable value to increase the reliability and further utilisation of evaluation instruments of this type.

Autosomal dominant ataxia: genetic evidence for locus heterogeneity from a Cuban founder-effect population.

The locus for autosomal dominant ataxia with a diagnosis of olivo-ponto-cerebellar atrophy at autopsy has been previously assigned to chromosome 6p. However, evidence for two alternative locations has been reported. We have recently described a large potential founder-effect population of such patients in the Holguin province of Cuba. With an estimated 1,000 patients available for analysis, this extensive cluster of families provides a unique opportunity for the definitive localization of the genetic mutation. Linkage analysis between the disease locus in this population and markers within and flanking the HLA region on chromosome 6 were undertaken in 12 families comprising over 100 affected individuals. Despite similarity in the clinical phenotype between those families where the disease locus has been reported to be linked to the HLA locus and the Cuban patients, no evidence of linkage to this region could be demonstrated in the latter. The disease locus was excluded from a 96-cM genetic interval of the short arm of chromosome 6, encompassing the F13A1-HLA-GLO1-MUT/D6S4 loci. These data strongly support the existence of genetic heterogeneity for the disease.