Irradiation dose does not affect male reproductive organ size, sperm storage, and female remating propensity in Ceratitis capitata.

The Mediterranean fruit fly Ceratitis capitata is a globally invasive pest, often controlled with the sterile insect technique (SIT). For the SIT, mass-rearing of the target insect followed by irradiation are imperatives. Sterile males are often less able to inhibit female remating and transfer less number of sperm, and even irradiation could affect male reproductive organs, with consequences for their ability to inhibit female remating. On the other hand, male age could affect their ability to modulate female response after mating. Here, we evaluated the quality of the genetic sexing strain Vienna-8-tsl mass-reared in Bioplanta San Juan, Argentina, under laboratory conditions, with regard to: (i) the ability of sterile males irradiated at 100 or 140 Gy to inhibit female remating, in the same day and at 24 h of first copulation; (ii) the ability of 3, 4 or 5 day-old sterile males to inhibit female remating at 24 h of first copulation, and (iii) the effect of a reduction in irradiation doses on the number of sperm stored by females and reproductive organ size in virgin males. Sterile males were better able than wild males to inhibit female remating in the same day of first copulation and as able as wild males 1 day after first copulation. Male age did not affect their ability to inhibit female receptivity. Number of sperm stored by females, testes size and ectodermal accessory glands size were not affected by male identity, while sterile 100 Gy males had larger mesodermal accessory glands than control lab males. A reduction in irradiation dose does not impact any variable measured, except for percentage of sperm-depleted females: females mated with sterile 100 Gy males had lower probabilities to store sperm. The results showed here are very encouraging for tsl Vienna 8 strain reared in Argentina and are discussed in comparison with previous studies in C. capitata female remating with dissimilar results.

Isolation and identification of bacteriocinogenic strain of Lactobacillus plantarum with potential beneficial properties from donkey milk.

AIMS: The goal of this study was to isolate and characterize a lactic acid bacteria (LAB) from donkey milk with potential beneficial properties. METHODS AND RESULTS: Lactic acid bacteria were isolated from donkey milk and identified based on physiological, biochemical and molecular methods. The isolate that presented highest bacteriocin potential (Lactobacillus plantarum LP08AD) was evaluated for the production of bacteriocin, including stability in the presence of various enzymes, surfactants, salts, pH and temperatures. Bactericidal effect of bacteriocin LP08AD on Listeria monocytogenes, Enterococcus faecium and Lactobacillus curvatus was shown for actively growing and stationary cells. Similar growth and bacteriocin production were observed when strain LP08AD was cultured in MRS broth at 30°C or 37°C. Bacteriocin LP08AD adhered at low levels on the producer cells (200 AU ml(-1) ). The presence of plantaricin W gene on the genomic DNA was recorded based on PCR. Good growth for strain LP08AD was recorded in MRS broth with pH from 5·0 to 9·0 and LP08AD grew well in the absence of oxbile or concentration below 0·8%. Lact. plantarum LP08AD was applied to the small intestinal epithelial polarized monolayers of H4, PSIc1 and CLAB and demonstrated low attachment ability on all cell lines studied, with values with a similar behaviour for cells from human and pig origin. CONCLUSIONS: Bacteriocin-producing Lact. plantarum LP08AD might be useful in the design of novel functional foods with potential probiotic or biopreservation properties. SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, this is the first report on detection and characterization of bacteriocinogenic Lact. plantarum from donkey milk. The strain LP08AD shows to have potential beneficial properties, as demonstrated by the use of noncancerogenic cell lines.

Low molecular weight oligochitosans for non-viral retinal gene therapy.

Ultrapure oligochitosans have recently been evaluated as a promising tool for corneal gene therapy; however, there are no reports regarding the potential use of this polymer in other ocular tissues. We have prepared and characterized at pH 7.1 oligochitosan/pCMS-EGFP polyplexes to evaluate the transfection efficiency in rat retinas after subretinal and intravitreal administration. Polyplexes were characterized in terms of shape, size, surface charge, DNA condensation, and transfection efficiency in HEK-293 and ARPE-19 culture cells. Polyplexes were positively charged, around 10 mV, and size oscillated between 256.5 ± 56 and 67.3 ± 0.44 nm, depending on the nitrogenous/phosphate ratio. Polyplexes efficiently protected the plasmid against enzymatic digestion. A drastic increase in transfection efficiency was observed when pH slightly decreased from 7.4 to 7.1 in both HEK-293 (from 19.1% to 51.5%) and ARPE-19 (from 2.0% to 36.5%) cells (data normalized to Lipofectamine™ 2000). In rat retinas, subretinal administrations transfected cells mainly in the RPE layer, whereas intravitreal injections transfected cells in the inner nuclear and plexiform layers of the retina and mainly in the ganglion cell layer. This study establishes the base for future treatments of genetic retinal disorders with low molecular weight oligochitosan polyplexes.

Succession of carrion fauna in the arid region of San Juan Province, Argentina and its forensic relevance.

The succession of carrion fauna and the decomposition stages were studied in the arid environment of San Juan Province, Argentina (31°32'34.7″ S; 68°34'39.4″ W). Two pig carcasses (Sus scrofa) were placed in wire mesh cages, 100 m apart from each other. Each carcass was surrounded by pitfall traps, and a modified Malaise trap was placed above. Daily samplings were carried out to collect the insects present in the carcasses and the traps, and body and environmental temperature were measured. The main colonizer species was Chrysomya albiceps (Wiedemann) and its larvae were dominant over other Diptera. The first adult blowflies emerged at 8.9 days. The time to reach the remains stage was 8 days shorter than for other South American sites. We recorded the early arrival of adult Dermestes maculates De Geer and Dermestes ater De Geer 2 days after the beginning of the assay, and larvae of these species were recorded 4 days after. We determined a 1.5-day error in the postmortem interval estimation using the temperatures measured in the assay and those recorded by the nearest meteorological station.

Uso selectivo de drenajes en tiroidectomías / Selective use of drainages in thyroidectomy

Background: There is controversy about the universal use of drainages in thyroid surgery. Aim: To evaluate the selective use of drainages in thyroid surgery, using them only in patients with high risk of developing a cervical hematoma. Material and Methods: Eight four patients subjected to thyroid surgery, were prospectively evaluated. Drainages were only used in those patients in whom a big cavity was left after thyroidectomy, patients with intrathoracic goiter and patients subjected to lymph node dissection. Results: Drainages were omitted in 68 patients (81 percent) aged 18 to 68 years, 59 females. Forty four (65 percent) of these patients were subjected to a total thyroidectomy, 14 (21 percent) to a subtotal thyroidectomy and 10 (7 percent) to a lobectomy. In 19 cases (28 percent) the biopsy informed a papillary cancer, the rest were benign lesions. One patient had a cervical hematoma that required a new operation. Hospital stay ranged from 1 to 4 days. Conclusions: The selective use of drainages in thyroid surgery is feasible, safe and allows a shorter hospital stay.

Introducción: El objetivo de este trabajo fue evaluar el uso selectivo de drenajes, omitiendo el dispositivo en la cirugía tiroidea corriente y empleándolo en pacientes con riesgo de desarrollar hematoma cervical. Material y Métodos: Estudio prospectivo de casos consecutivos entre enero 2008 y junio 2009 que incluyó 84 pacientes con diversas patologías tiroideas sometidos a tiroidectomía total o parcial. Los parámetros evaluados fueron: edad, género, procedencia, extensión de la cirugía, biopsia de piezas operatorias, estadía hospitalaria y complicaciones perioperatorias. Resultados: De los 84 casos, en 68 (81 por ciento) no se usó drenaje y en 16 (19 por ciento) se empleó el dispositivo. De los 68 casos en que no se utilizó drenaje 59 (86,8 por ciento) fueron mujeres y 9 (13,2 por ciento) hombres, edad promedio 44,4 años (rango: 18 y 68 años). Se practicó 44 (64,7 por ciento) tiroidectomias totales, 14 (20,5 por ciento) tiroidectomias subtotales y 10 (6,8 por ciento) lobectomias e istmectomía. La biopsia informó cáncer papilar en 19 (27,9 por ciento) casos y 47 (69,1 por ciento) lesiones benignas. Las complicaciones fueron 1 (1,4 por ciento) hematoma cervical que requirió reoperación y 7 (10,2 por ciento) seromas. La estadía hospitalaria fluctuó entre 1 y 4 días, promedio 1,9; con hospitalización de 1 día 21 (30,8 por ciento) pacientes, 2 días 36 (52,9 por ciento), 3 días 8 (11,7 por ciento) y 4 días 2 (2,9 por ciento). Conclusiones: Concluimos que es posible el uso selectivo de drenaje en tiroidectomías. Acorde a la patología tiroidea quirúrgica que manejamos y aplicando nuestros criterios de selección la mayoría de los pacientes no precisa estos dispositivos. La ausencia de drenajes no conlleva mayores complicaciones y posibilita una estadía hospitalaria breve.

Interrupción percutánea de vena cava inferior / Percutaneous inferior vena cava interruption

El tromboembolismo pulmonar (TEP) representa una causa frecuente de muerte en pacientes hospitalizados, siendo su principal causa la trombosis venosa profunda (TVP) de las extremidades inferiores, cuya medida de profilaxis es, entre otras, el uso de Heparina. Ocasionalmente se debe recurrir a medidas invasivas como lo es el control de la vena cava inferior. Este articulo presenta un case de interrupción percutánea de vena cava inferior. Se pretende actualizar la información respecto al uso de los filtros y enfatizar la tendencia actual a ser un procedimiento en expansión. Los diseños han ido evolucionando y los beneficios permiten demostrar que el filtro de vena cava (FVC) es una opción terapéutica en pacientes seleccionados.

Hantavirus infection in people inhabiting a highly endemic region of the Gran Chaco territory, Paraguay: association with Trypanosoma cruzi infection, epidemiological features and haematological characteristics.

The seroprevalences of anti-hantavirus antibodies were determined in 712 individuals (551 Indians, 140 Mennonites of German ancestry, and 21 Paraguayans of Spanish ancestry) inhabiting a region of western Paraguay in the Gran Chaco territory of South America. The overall seroprevalence of hantavirus infection among the 712 subjects, who were aged 2-80 years, was 42.7% (45.2% in the Indians and 34.2% in the non-Indians). Of the 672 subjects also checked for antibodies against Trypanosoma cruzi, 226 (33.6%) were seropositive for this protozoan parasite. The results of a multivariate regression analysis indicated that, after adjusting for age, sex, setting of residence (rural/urban) and infection with the human T-cell leukaemia/lymphoma virus type II (HTLV-II), a T. cruzi-seropositive individual was 1.73 times more likely to be hantavirus seropositive than a T. cruzi-seronegative individual. Living in a rural setting increased the risk of being hantavirus seropositive 2.17-fold. In both the Indians and non-Indian subpopulations, hantavirus seroprevalence increased with age in both sexes, but only in the non-Indian supopulation was this increase significantly greater in males than in females. Hantavirus seropositivity was significantly associated with thrombocytosis, even after adjusting for the relevant confounders.

Model-based clustering and data transformations for gene expression data.

MOTIVATION: Clustering is a useful exploratory technique for the analysis of gene expression data. Many different heuristic clustering algorithms have been proposed in this context. Clustering algorithms based on probability models offer a principled alternative to heuristic algorithms. In particular, model-based clustering assumes that the data is generated by a finite mixture of underlying probability distributions such as multivariate normal distributions. The issues of selecting a 'good' clustering method and determining the 'correct' number of clusters are reduced to model selection problems in the probability framework. Gaussian mixture models have been shown to be a powerful tool for clustering in many applications. RESULTS: We benchmarked the performance of model-based clustering on several synthetic and real gene expression data sets for which external evaluation criteria were available. The model-based approach has superior performance on our synthetic data sets, consistently selecting the correct model and the number of clusters. On real expression data, the model-based approach produced clusters of quality comparable to a leading heuristic clustering algorithm, but with the key advantage of suggesting the number of clusters and an appropriate model. We also explored the validity of the Gaussian mixture assumption on different transformations of real data. We also assessed the degree to which these real gene expression data sets fit multivariate Gaussian distributions both before and after subjecting them to commonly used data transformations. Suitably chosen transformations seem to result in reasonable fits. AVAILABILITY: MCLUST is available at http://www.stat.washington.edu/fraley/mclust. The software for the diagonal model is under development. CONTACT: kayee@cs.washington.edu. SUPPLEMENTARY INFORMATION: http://www.cs.washington.edu/homes/kayee/model.

Unsuspected hyperhomocysteinemia in chronically anticoagulated patients.

Hyperhomocysteinemia is a risk factor for arterial and venous thrombosis. The aim of this study was to evaluate plasmatic homocysteine levels in patients under chronic anticoagulant treatment with dietary restriction of green vegetables. This kind of food is a very important source not only of vitamin K but also of folates, which are involved in Hcy metabolism. It is known that the lower the folate levels, the higher the Hcy concentration, so we suspected that these patients could show hyperhomocysteinemia. A group of patients receiving oral anticoagulant treatment and a restricted diet (Group I, n = 20) was compared with a group of untreated subjects of a similar age that were not on a restricted diet (Group II, n = 35). Group I showed significantly higher levels of plasmatic Hcy and significantly lower levels of serum folate than Group II. Therefore, a diet restricted in vitamin K applied to oral anticoagulated patients could induce an unwanted increase of homocysteine levels.

Validation of an enzyme immunoassay for the determination of total homocysteine in plasma.

In recent years, the determination of homocysteine (Hcy) has become increasingly important, since high levels of Hcy in plasma or serum represent an independent risk factor for occlusive vascular diseases. Nowadays, clinical laboratories use several analytical techniques to measure Hcy, of which high-performance liquid chromatography (HPLC) is the most popular. Recently, assays for Hcy quantification based on enzyme immunoassays (EIA) have become commercially available. Our group carried out the validation of the Axis method and compared results with those obtained by an established HPLC assay. Intra- and inter-assay coefficients of variation were < or = 8.5%. Compared with HPLC, linear regression analysis showed r=0.984, slope=0.952, intercept = 1.24 /mol/l; Bland-Altman procedure, the mean of the difference EIA-HPLC results = 0.5 micromol/l. Our results suggest that Hcy determinations by both methods are equivalent, and that the Axis assay provides reproducible and reliable data.

Plasmatic homocysteine response to vitamin supplementation in elderly people.

Homocysteine (Hcy) increase is now widely accepted as a risk factor for vascular disease. The effects of folic acid (FA) and vitamins B12 and B6 in lowering Hcy have been extensively studied, but there is still little data on the response to FA dietary administration. Our purpose was to evaluate the impact of the diet and the degree of response to different doses of pharmacological FA supplementation. In a prospective, randomized, and simple blind study, 50 elderly subjects were given a 400-microg/day FA diet and were randomly assigned to one of the following treatments: Group I = placebo tablet; Group II = tablet containing 1-mg folic acid, 1-mg B12, and 25-mg B6; and Group III = tablet containing 2.5-mg folic acid and same B6 and B12 doses as Group II. Forty-four subjects completed the study, and their plasmas were evaluated. Hcy concentration significantly decreased even in patients with normal basal values, and there were no differences in the response between individuals receiving diet plus placebo and those receiving diet plus pharmacological supplementation. After the treatment, the mean decrease of plasmatic Hcy levels was 10.8 (9.4, 12.5) micromol/l, geometric mean [95% confidence interval (95% CI)], and particularly, the values for Group I were 10.6 (7.4, 14.8) micromol/l. In 31% of the subjects, the post-treatment Hcy levels were less than or = 5 micromol/l. These results show that a special diet, with or without pharmacological FA and B12 and B6 supplementation, significantly decreases the Hcy levels in elderly people. Therefore, a diet with high contents of FA might have an enormous impact on the morbidity and mortality of atherothrombosis.

[Analysis of some variables in patients with hydatidosis surgically treated at the Regional Hospital of Valdivia, Chile, 1976-1986]. / Análisis de algunas variables en pacientes con hidatidosis tratados quirúrgicamente en el Hospital Regional de Valdivia, Chile, 1976-1986.

A survey of surgically treated cases of hydatidosis in the province of Valdivia, Chile, was done. Data were provided by the Regional Hospital of Valdivia, and a period of eleven years was covered (1976-1986). Disease, treatment and related data from each patient were consigned. For the analysis, the information was grouped according to: sex, age, cyst location, condition of the cyst, concomitance with another pathology, condition at time of discharge, hospitalization period and number of repeat hospitalizations. In the period studied, 197 cases of hydatidosis were surgically treated. The sex distribution was 53.3% for males and 46.7 for females; the age group 10-19 years was the most affected by the disease (19.3%). The most frequent locations of hydatid cysts were the liver (58.9%) and lungs (36.5%); the 38.6% of the patients showed complicated cysts, mainly with bacterial infections (11.7%); also, 20% of the cases presented a concomitant liver-related pathology. After the operation, 153 (77.7%) clinically recovered and 27 (13.7%) non-recovered patients left the hospital and 7 (3.5%) cases died while hospitalized. The average hospitalization period was 29 days. During 1976-1986, 24 patients were rehospitalized.

Quiste hidatídico hepático / Hepatic hydatid cyst

La hidatidosis hepática es una zoonosis de alta incidencia en Chile, 5.6 por millón de habitantes. Se diagnostican 800 casos nuevos por año, que corresponden a menos de la tercera parte de las personas parasitadas. En la Décima Región, especialmente Panguipulli, Paillaco y zonas muy rurales, esta parasitosis es prácticamente endémica. La conducta médica lógica frente a la hidatidosis es prevenirla, mediante educación a la comunidad y en especial a grupos familiares parasitados. El médico general debe pensar en hidatidosis hepática frente a un paciente con dolor no cólico en hipocondrio derecho, sin relación evidente con la alimentación, con o sin masa palpable abdominal y con antecedentes familiares de hidatidosis, especialmente si proviene de una zona endémica. Los médtodos no invasivos (ecografía, tomografía), son los de mayor rendimiento para el diagnóstico. El tratamiento de la hidatidosis hepática es quirúrgico, electivo y precoz, por la frecuencia (26.2% a 58.5%) de complicaciones (ruptura, infección). El quiste complicado se asocia a mayor morbilidad operatoria. La técnica quirúrgica más empleada aún en Chile es la quistectomía más drenaje externo, pese a una morbilidad post-operatoria de 36.5% a 79.2%, de reintervenciones hasta en un 44%, de hospitalizaciones mayores de 30 días y de una mortalidad de 5-13.7%. Es por esto que actualmente se recomienda técnicas resectivas, que eliminan la cavidad residual, factor fundamental en la morbimortalidad postoperatoria. Las intervenciones resectivas para quiste hidatídico hepático incluyen, resecciones hepáticas regladas (segmentectomías, lobectomías, hepatectomía) en quistes que ocupan un segmento o un lóbulo y perisquistectomía en quistes superficiales o profundos intersegmentarios o interlobares. Estas técnicas requieren un completo estudio preoperatorio y un equipo quirúrgico con experiencia en cirugía hepática. La morbilidad de las técnicas resectivas es menor de 10% y la mortalidad, menor de 5%, con períodos de hospitalización de 7 a 15 días. En caso de contraindicación para el tratamiento quirúrgico o frente a la posibilidad de una siembra hidatídica, se justifica intentar tratamiento médico de la hidatidosis. El medicamento escolicida actualmente recomendado es el Albendazole; en dosis de 10 mgr/Kg/días administrado en dos tomas diarias durante 28 días, seguido de un período de descanso de 14 días. Debe vigilarse con controles periódicos hematológicos y de función hepática. Finalmente se pres