Genomic and proteomic characterization of two strains of Shigella flexneri 2 isolated from infants' stool samples in Argentina.

BACKGROUND: Shigella specie is a globally important intestinal pathogen disseminated all over the world. In this study we analyzed the genome and the proteomic component of two Shigella flexneri 2a clinical isolates, collected from pediatric patients with gastroenteritis of the Northwest region of Argentina (NWA) in two periods of time, with four years of difference. Our goal was to determine putative changes at molecular levels occurred during these four years, that could explain the presence of this Shigella`s serovar as the prevalent pathogen in the population under study. RESULTS: As previously reported, our findings support the idea of Shigella has a conserved "core" genome, since comparative studies of CI133 and CI172 genomes performed against 80 genomes obtained from the NCBI database, showed that there is a large number of genes shared among all of them. However, we observed that CI133 and CI172 harbors a small number of strain-specific genes, several of them present in mobile genetic elements, supporting the hypothesis that these isolates were established in the population by horizontal acquisition of genes. These differences were also observed at proteomic level, where it was possible to detect the presence of certain secreted proteins in a culture medium that simulates the host environment. CONCLUSION: Great similarities were observed between the CI133 and CI172 strains, confirming the high percentage of genes constituting the "core" genome of S. flexneri 2. However, numerous strain specific genes were also determined. The presence of the here identified molecular elements into other strain of our culture collation, is currently used to develop characteristic markers of local pathogens. In addition, the most outstanding result of this study was the first description of a S. flexneri 2 producing Colicin E, as one of the characteristics that allows S. flexneri 2 to persist in the microbial community. These findings could also contribute to clarify the mechanism and the evolution strategy used by this pathogen to specifically colonize, survive, and cause infection within the NWA population.

Transduction for pheromones in the main olfactory epithelium is mediated by the Ca2+ -activated channel TRPM5.

Growing evidence suggests that the main olfactory epithelium contains a subset of olfactory sensory neurons (OSNs) responding to pheromones. One candidate subpopulation expresses the calcium activated cation channel TRPM5 (transient receptor potential channel M5). Using GFP driven by the TRPM5 promoter in mice, we show that this subpopulation responds to putative pheromones, urine, and major histocompatibility complex peptides, but not to regular odors or a pheromone detected by other species. In addition, this subpopulation of TRPM5-GFP+ OSNs uses novel transduction. In regular OSNs, odorants elicit activation of the cyclic nucleotide-gated (CNG) channel, leading to Ca2+ gating of Cl- channels; in TRPM5-GFP+ OSNs, the Ca2+ -activated Cl- ANO2 (anoctamin 2) channel is not expressed, and pheromones elicit activation of the CNG channel leading to Ca2+ gating of TRPM5. In conclusion, we show that OSNs expressing TRPM5 respond to pheromones, but not to regular odors through the opening of CNG channels leading to Ca2+ gating of TRPM5.

Regioselective Synthesis of Cycloalkane-fused Pyrazolo[4,3-e]pyridines through Tandem Reaction of 5-aminopyrazoles, Cyclic Ketones and Electron-rich Olefins.

BACKGROUND: Pyrazolopyridines are interesting fused heterocyclic pharmacophores that combine pyrazole and pyridine; two privileged nuclei extensively studied and with a wide range of applications. They can be obtained by a broad variety of synthetic methods among which multicomponent reactions have gained importance, especially from 5-aminopyrazoles and dielectrophilic reagents. However, the search for new approaches more in tune with sustainable chemistry and the use of unconventional heating in three-component synthesis are open and highly relevant study fields. METHODS: A novel, practical and efficient three-component synthesis of cycloalkane-fused pyrazolo[ 4,3-e]pyridines was developed through a tandem reaction of 5-aminopyrazoles, cyclic ketones and electron-rich olefins, using microwave induction in perfluorinated solvent and iodine as catalyst. RESULTS: The microwave-induced three-component approach applied in this work promoted the construction of 10 new pyrazolopyridines with high speed and excellent control of regioselectivity, favoring the linear product with good yields; where the versatility of electron-rich olefins in iodine-catalyzed cascade heterocyclizations, granted the additional benefit of easy isolation and the possibility to reuse the fluorous phase. CONCLUSION: Although pyrazolopyridines have been synthetically explored because of their structural and biological properties, most of the reported synthetic methods use common or even toxic organic solvents and conventional heating or multi-step processes. In contrast, this study applied a multicomponent methodology in a single step by microwave induction and with the versatility provided in this case by the use of perfluorinated solvent, which allowed easy isolation of the final product and recovery of the fluorous phase.

Impact of COVID-19 vaccination on liver transplant recipients. Experience in a reference center in Mexico.

BACKGROUND AND AIMS: COVID-19 vaccination has proved to be effective to prevent symptomatic infection and severe disease even in immunocompromised patients including liver transplant patients. We aim to assess the impact of COVID-19 vaccination on the mortality and development of severe and critical disease in our center. METHODS: A retrospective cohort study of LT patients in a reference center between March 2020 and February 2022. Demographic data, cirrhosis etiology, time on liver transplantation, immunosuppressive therapies, and vaccination status were recorded at the time of diagnosis. Primary outcome was death due to COVID-19, and secondary outcomes included the development of severe COVID-19 and intensive care unit (ICU) requirement. RESULTS: 153 of 324 LT recipients developed COVID-19, in whom the main causes of cirrhosis were HCV infection and metabolic-associated fatty liver disease. The vaccines used were BNT162b2 (48.6%), ChAdOx1 nCoV-19 (21.6%), mRNA-1273 vaccine (1.4%), Sputnik V (14.9%), Ad5-nCoV-S (4.1%) and CoronaVac (9.5%). Case fatality and ICU requirement risk were similar among vaccinated and unvaccinated LT patients (adjusted relative case fatality for vaccinated versus unvaccinated of 0.68, 95% CI 0.14-3.24, p = 0.62; adjusted relative risk [aRR] for ICU requirement of 0.45, 95% CI 0.11-1.88, p = 0.27). Nonetheless, vaccination was associated with a lower risk of severe disease (aRR for severe disease of 0.32, 95% CI 0.14-0.71, p = 0.005). CONCLUSIONS: Vaccination reduces the risk of severe COVID-19 in LT patients, regardless of the scheme used. Vaccination should be encouraged for all.

The PmrAB system-inducing conditions control both lipid A remodeling and O-antigen length distribution, influencing the Salmonella Typhimurium-host interactions.

The Salmonella enterica serovar Typhimurium lipopolysaccharide consisting of covalently linked lipid A, non-repeating core oligosaccharide, and the O-antigen polysaccharide is the most exposed component of the cell envelope. Previous studies demonstrated that all of these regions act against the host immunity barrier. The aim of this study was to define the role and interaction of PmrAB-dependent gene products required for the lipopolysaccharide component synthesis or modification mainly during the Salmonella infection. The PmrAB two-component system activation promotes a remodeling of lipid A and the core region by addition of 4-aminoarabinose and/or phosphoethanolamine. These PmrA-dependent activities are produced by activation of ugd, pbgPE, pmrC, cpta, and pmrG transcription. In addition, under PmrA regulator activation, the expression of wzz(fepE) and wzz(st) genes is induced, and their products are required to determine the O-antigen chain length. Here we report for the first time that Wzz(st) protein is necessary to maintain the balance of 4-aminoarabinose and phosphoethanolamine lipid A modifications. Moreover, we demonstrate that the interaction of the PmrA-dependent pbgE(2) and pbgE(3) gene products is important for the formation of the short O-antigen region. Our results establish that PmrAB is the global regulatory system that controls lipopolysaccharide modification, leading to a coordinate regulation of 4-aminoarabinose incorporation and O-antigen chain length to respond against the host defense mechanisms.

Portopulmonary Hypertension: An Updated Review.

Portal hypertension may have major consequences on the pulmonary vasculature due to the complex pathophysiological interactions between the liver and lungs. Portopulmonary hypertension (PoPH), a subset of group 1 pulmonary hypertension (PH), is a serious pulmonary vascular disease secondary to portal hypertension, and is the fourth most common subtype of pulmonary arterial hypertension. It is most commonly observed in cirrhotic patients; however, patients with noncirrhotic portal hypertension can also develop it. On suspicion of PoPH, the initial evaluation is by a transthoracic echocardiogram in which, if elevated pulmonary pressures are shown, patients should undergo right heart catheterization to confirm the diagnosis. The prognosis is extremely poor in untreated patients; therefore, management includes pulmonary arterial hypertension therapies with the aim of improving pulmonary hemodynamics and moving patients to orthotopic liver transplantation (OLT). In this article, we review in detail the epidemiology, pathophysiology, process for diagnosis, and most current treatments including OLT and prognosis in patients with PoPH. In addition, we present a diagnostic algorithm that includes the current criteria to properly select patients with PoPH who are candidates for OLT.

The PmrA/PmrB regulatory system controls the expression of the wzzfepE gene involved in the O-antigen synthesis of Salmonella enterica serovar Typhimurium.

The degree of polymerization of O-antigen from Salmonella enterica serovar Typhimurium is controlled by the products of the wzz(s)(t) and wzz(fepE) genes. In the present study we investigated the role of the PmrA/PmrB regulatory system in wzz(fepE) transcription. We report that the direct binding of the PmrA regulator to a specific promoter site induces the expression of the wzz(fepE) gene. This effect increases the amount of very long (VL) O-antigen, which is required for the resistance of Salmonella to serum human complement and polymyxin B, and for the replication of the bacteria within macrophages. The results obtained here highlight functional differences between Wzz(fepE) and Wzz(st), although the genes for both proteins are regulated in a PmrA-dependent way.

Exact results on high-dimensional linear regression via statistical physics.

It is clear that conventional statistical inference protocols need to be revised to deal correctly with the high-dimensional data that are now common. Most recent studies aimed at achieving this revision rely on powerful approximation techniques that call for rigorous results against which they can be tested. In this context, the simplest case of high-dimensional linear regression has acquired significant new relevance and attention. In this paper we use the statistical physics perspective on inference to derive several exact results for linear regression in the high-dimensional regime.

Transcriptional autoregulation of the RcsCDB phosphorelay system in Salmonella enterica serovar Typhimurium.

The RcsCDB (Rcs) phosphorelay system is involved in the regulation of many envelope genes, such as those responsible for capsule synthesis, flagella production and O-antigen chain length, as well as in other cellular activities of several enteric bacteria. The system is composed of three proteins: the sensor RcsC, the response regulator RcsB, and the phospho-transfer intermediary protein RcsD. Previously, we reported two important aspects of this system: (a) rcsB gene expression is under the control of P(rcsDB) and P(rcsB) promoters, and (b) rcsD gene transcription decreases when the bacteria reach high levels of the RcsB regulator. In the present work, we demonstrate that the RcsB protein represses rcsD gene expression by binding directly to the P(rcsDB) promoter, negatively autoregulating the Rcs system. Furthermore, we report the physiological role of the RcsB regulator, which is able to modify bacterial swarming behaviour when expressed under the control of the P(rcsB) promoter.

Epidemiological study of prevalent pathogens in the Northwest region of Argentina (NWA).

Northwest Argentina (NWA) is a poor economic-geographical region, with the highest rate of diarrhea diseases. At the moment, there are no reports showing the epidemiological status of this region that would allow to establish methods for prevention and control of these infections and to indicate of the prevalent pathogen that produces them. Therefore we carried out an epidemiological study of the gastroenteritis etiological agents and their incidence in the pediatric population. A total of 17 823 fecal samples were collected, 14 242 from HNJ-Tuc, 2,257 from CePSI-Stgo and 1,324 from HINEP-Cat. In 2,595 samples a bacterial agent was identified, the 93.64% corresponded to Shigella/Salmonella clinical isolates. Shigella genus was the prevalent pathogen, being Shigella flexneri 2 the most frequent serotype. Most of the Shigella clinical isolates presented themselves as multidrug-resistant (MDR), harboring 2 to 3 genetic resistance determinants. 50% of the affected patients were children under 4 years old. Here, we demonstrate that bacterial gastrointestinal diseases strongly affect the health of NWA population. The appearance of epidemic outbreaks, as happened during 2014, suggest that they may be related to the socio-economic poverty of NWA. Recently, Shigella flexneri 2 has become the highest NWA´s incidence infectious agent. The acquisition of new antibiotic resistance determinants may play an important role in their adaptation and persistence.

Cross-talk between the RcsCDB and RstAB systems to control STM1485 gene expression in Salmonella Typhimurium during acid-resistance response.

Bacterial survive and respond to adverse changes in the environment by regulating gene transcription through two-component regulatory systems. In Salmonella Typhimurium the STM1485 gene expression is induced under low pH (4.5) during replication inside the epithelial host cell, but it is not involved in sensing or resisting to this condition. Since the RcsCDB system is activated under acidic conditions, we investigated whether this system is able to modulate STM1485 expression. We demonstrated that acid-induced activation of the RcsB represses STM1485 transcription by directly binding to the promoter. Under the same condition, the RstA regulator activates the expression of this gene. Physiologically, we observed that RcsB-dependent repression is required for the survival of bacteria when they are exposed to pancreatic fluids. We hypothesized that STM1485 plays an important role in Salmonella adaptation to pH changes, during transition in the gastrointestinal tract. We suggest that bacteria surviving the gastrointestinal environment invade the epithelial cells, where they can remain in vacuoles. In this new environment, acidity and magnesium starvation activate the expression of the RstA regulator in a PhoPQ-dependent manner, which in turn induces STM1485 expression. These levels of STM1485 allow increased bacterial replication within vacuoles to continue the course of infection.

RcsB-dependent effects on nar operon regulation during the aerobic growth of Salmonella Typhimurium.

The intracellular pathogen Salmonella is an important cause of human foodborne diseases worldwide. Salmonella takes advantage of the phosphorelay regulatory systems to survive in the hostile environment of the host's gastrointestinal tract. It has been reported that the nitrate reductase Z (NR-Z), encoded by the narUZYV operon, is required during Salmonella transition to anaerobic environments and is constitutively produced at low levels, but little is known about the regulatory mechanism involved in the operon gene expression. In this work, we found that the RcsCDB system is activated by high concentrations of specific sugars as a carbon source. In this activation state, the RcsCDB system participates in the negative control of narUZYWV expression. This control strategy occurs during exponential growth when the carbon source is high, allowing for normal aerobic respiration. The RcsCDB system's participation in aerobic respiration is necessary to ensure efficient metabolism and optimal energy consumption when the bacteria are growing exponentially.

EVALUACIÓN DE UN TERMOFOSFATO EN EL CRECIMIENTO Y PRODUCCIÓN DE FRESA (Fragaria x ananassa Duch.) cv. 'ALBIÓN' / EVALUATION OF THERMOPHOSPHATE IN GROWTH AND PRODUCTION THE STRAWBERRY Fragaria x ananassa Duch.) cv. 'ALBIÓN'

RESUMEN La fresa es una de las frutas más importantes en el mundo, por sus múltiples usos industriales, medicinales y culinarios. En Colombia, la producción se concentra en los departamentos de Cundinamarca, Antioquia, Norte de Santander, Cauca y Boyacá. Su crecimiento y productividad están determinados por una adecuada fertilización en elementos, como nitrógeno (N), potasio (K), calcio (Ca) y fósforo (P), siendo el P un elemento de gran importancia, en diversos procesos fisiológicos, pero con baja disponibilidad para las plantas, en suelos con condiciones de acidez. Por esta razón, el objetivo de la investigación fue evaluar el efecto de una fuente no convencional de fósforo (termofosfato), en el crecimiento y en la producción de plantas de fresa cv. 'Albión', bajo condiciones del municipio de Viracachá, Boyacá. Se utilizó un diseño experimental completamente al azar, con 4 tratamientos, que correspondieron a dosis crecientes de termofosfato (0, 300, 600 y 900kg ha-1), con 4 repeticiones. Se evaluó el contenido de clorofilas totales, peso seco de parte aérea y raíz, número de estructuras reproductivas, producción de frutos, concentración foliar de P, Ca y silicio (Si). Se presentaron diferencias significativas (P≤0,05) en las variables clorofilas totales, peso seco de raíz, producción por calidad, concentración foliar de P y Si; las demás variables no mostraron diferencias estadísticas. Los mejores resultados, se presentaron con los tratamientos de 300 y 600kg ha-1 de termofosfato, convirtiéndolo en una alternativa de suministro en suelos con problemas de acidez y baja disponibilidad de P.

SUMMARY The strawberry is one of the most important fruits in the world for its multiple industrial, medicinal and culinary uses. In Colombia, the production is concentrated in the departments of Cundinamarca, Antioquia, Norte de Santander, Cauca and Boyacá. Its growth and productivity are determined by an adequate fertilization in elements such as nitrogen (N), potassium (K), calcium (Ca) and phosphorus (P), being P an element of great importance in various physiological processes but with low availability for plants in soils with acidic conditions. For this reason, the aim of this study was to evaluate the effect of an unconventional source of phosphorus (thermophosphate), on the growth and production of strawberry plants cv. 'Albión' under conditions of the municipality of Viracachá, Boyacá. A completely randomized experimental design was used, with 4 treatments, which were increasing doses of thermophosphate (0, 300, 600 and 900kg ha-1) with 4 repetitions. The content of total chlorophylls, dry weight of aerial part and root, number of reproductive structures, production and foliar concentration of phosphorus, calcium and silicon were evaluated. There were significant differences (P≤0.05) in the variables total chlorophyll, root dry weight, production by quality, foliar concentration of P, Ca and silicon (Si); the other variables did not show statistical differences. The best results were presented with the treatments of 300 and 600 kg ha-1 of thermophosphate turning it into an alternative supply in soils with acidity problems and low availability of P.

Estado nutricional de pacientes en dos centros hospitalarios de villavicencio, colombia, 2015

Objetivo. Establecer el estado nutricional en pacientes de dos instituciones hospitalarias de Villavicencio. Método. Estudio de corte transversal, prospectivo, mediante una encuesta en 2 instituciones hospitalarias de Villavicencio, Colombia, en febrero de 2015. Se incluyeron pacientes adultos hospitalizados en servicios quirúrgicos. Los datos fueron registrados en Excel y se realizaron análisis estadísticos con SPSS a fin de encontrar asociaciones entre las variables de estudio y los desenlaces. El nivel de significancia se estableció cuando la p<0,05 mediante la prueba de Chi cuadrado y la t de Student. Resultados. Se entrevistaron 116 pacientes. El 56% de los pacientes fueron del hospital público, 58,8% fueron de servicios quirúrgicos y 65% fueron hombres. La edad promedio fue 65,7 (± 20,6) años. Solo 37,1% de los pacientes tenía el peso registrado en la historia clínica, por lo cual solo se pudo determinar el estado nutricional al 31% de los encuestados. Solo se pudo determinar un 23,1% de malnutrición, entre los cuales había un 9,5% de bajo peso. Los pacientes con mayor estancia hospitalaria fueron los del hospital público, en condición de desnutrición, sobrepeso y obesidad. No se pudo establecer asociación con mortalidad. Conclusiones. La desnutrición es una enfermedad de alta prevalencia en pacientes hospitalizados pero no es diagnosticada frecuentemente. Las medidas antropométricas no son registradas en todas las historias clínicas de los pacientes hospitalizados y se requiere un mayor nivel de sensibilización de los trabajadores de salud para establecer medidas de intervención temprana a fin de obtener mejores desenlaces clínicos.

Objective. To determine the nutritional status and outcomes of patients in 2 hospitals in Villavicencio. Method. Prospective cross-sectional study, survey conducted in two hospitals in Villavicencio, Colombia, on February 24th, 2015. Adult patients from surgical or clinical wards were included. Data was registered in Excel and statistical analysis with SPSS was conducted to determine association between independent variables and outcomes (Mortality and length of stay). Significance was established as p<0,05 with Chi square and Student T test. Results. One hundred and sixteen patients were surveyed. Fifty-six percent of patients were from the public hospital, 58,5% were from surgical wards and 65% were men. Average age was 65,7 (± 20,6) years old. Only 37,1% of the patients had the weight registered in the clinical chart, so nutritional status could be determined in only 31%. Only 23,1% of malnutrition was found, including a 9,5% of underweighted patients. Longer length of stay was found in patients from the public hospital, as well as, under-nutrition, overweight and obesity. No association with mortality was found. Conclusions. Under-nutrition is a prevalent disease in hospitalized patients, but it is not often diagnosed. Anthropometric measures are not registered in all clinical charts of hospitalized patients and it is required a higher level of sensitivity among health care workers, in order to establish early intervention measures, and to get better clinical outcomes.

Objetivo. Estabelecer o estado nutricional em pacientes de dos hospitais de Villavicencio. Metodologia. Estudo de corte transversal, prospectivo, através de pesquisa em 2 hospitais de Villavicencio, Colômbia, em fevereiro de 2015. Pacientes adultos internados em serviços cirúrgicos foram incluídos. Os dados foram registrados em Excel y análise estadística com SPSS foi realizada a fim de encontrar associações entre as variáveis de estudo e os resultados. O nível de significância foi estabelecido quando p<0,05 através do teste Qui Quadrado e a distribuição t de Student. Resultados. 16 pacientes foram entrevistados. 56% dos pacientes eram do hospital público, 58,8% foram de serviços cirúrgicos e 65% eram homens. A idade média foi de 65,7 (20,6 ±) anos. Apenas 37,1% dos pacientes tiveram o peso registado na sua ficha, por isso só foi possível determinar o estado nutricional de 31% dos entrevistados. Foi possível determinar apenas 23,1% de desnutrição, entre os quais havia 9,5% de baixo peso. Os pacientes com maior tempo de internação foram aqueles do hospital público, com desnutrição, sobrepeso e obesidade. Não foi possível estabelecer associação com a mortalidade. Conclusões. A desnutrição é uma doença altamente prevalente em pacientes hospitalizados, mas muitas vezes não é diagnosticada. As medidas antropométricas não são registradas em todas as histórias clínicas de pacientes hospitalizados e um maior nível de sensibilização dos trabalhadores de saúde é necessário para estabelecer medidas de intervenção precoce para obter melhores resultados clínicos.

Efficacy of microcin J25 in biomatrices and in a mouse model of Salmonella infection.

OBJECTIVES: To study the possible therapeutic utility of microcin J25 (MccJ25), a peptide RNA polymerase inhibitor. METHODS: We subjected the antibiotic to two types of assays. First, with an ex vivo assay, we evaluated the stability and efficacy of MccJ25 in complex fluid biomatrices such as human whole blood, plasma and serum, compared with that in conventional laboratory media. Antimicrobial efficacy of MccJ25 was assessed by quantitative culture 2 h after inoculation of the biomatrices with a Salmonella Newport target organism and compared with that of MccJ25-free controls. Second, the antibiotic was tested in a mouse model of Salmonella infection. The latter was induced by intraperitoneal inoculation of 10(6) cfu of Salmonella Newport and the treatment with MccJ25 was initiated at 2 h post-infection. RESULTS: MccJ25 retained full activity after 24 h of incubation in whole blood, plasma or serum. In addition, it did not show any haemolytic activity. In whole blood, homologous plasma and serum, introduction of MccJ25 was associated with a significant reduction in cfu versus the respective peptide-free controls. The counts of viable bacteria in the spleen and liver of mice treated with MccJ25 at a total dosage of 3 mg/mouse during either 24 h (0.5 mg/mouse every 4 h) or 6 days (0.5 mg/mouse every 24 h) significantly decreased by two or three orders of magnitude (P

Fascioliasis coledociana por Fasciola hepatica en cirugía de colecistitis crónica calculosa / Choledocal fasciolasis by Fasciola hepatica in surgery of chronic calculous cholecistitis

Se reporta un caso de Fasciola hepatica en una mujer de 50 años de edad, natural de Huaral, procedente de un asentamiento humano del distrito de Ate en Lima, con un tiempo de enfermedad de siete días caracterizado al inicio por dolor abdominal tipo cólico de curso progresivo en el epigastrio, dolor que se irradia a hipocondrio derecho. Luego presentó luego náuseas y vómitos en cuatro oportunidades, de contenido alimenticio y bilioso, por lo que se decide su hospitalización previa atención por emergencia. Al examen físico se encontró conjuntivas oculares levemente ictéricas, abdomen balonado, blando, depresible, no visceromegalia, Murphy positivo, ruidos hidroaéreos presentes, tórax y pulmones sin alteraciones. Posteriormente a los exámenes auxiliares, se diagnosticó colecistitis calculosa aguda y fascioliasis coledociana. En el acto quirúrgico se extrajo tres especímenes identificados como Fasciola hepatica. La paciente después de recibir el triclabendazol, concurrió al Hospital para la evaluación y control, habiendo logrado mejoría y bienestar.

We report a case of Fasciola hepatica in a 50 year-old woman born in Huaral, Lima, and living in Ate Vitarte, district of Lima, Peru, who was admitted because of seven days of disease characterized by progressive abdominal pain. She visited AteÆs Hospital because of right hipocondrial and epigastric cramping abdominal pain in the morning accompanied by nausea and vomiting in four opportunities. Conjunctives were slightly icteric, abdomen was distended and depressible, there was no visceromegaly, MurphyÆs sign was positive, and thorax and lungs showed no alterations. At cholecistectomy three specimens identified as Fasciola hepatica were extracted. Following treatment with triclabendazole, clinical course was uneventful.

Characterization of a new xylitol-producer Candida tropicalis strain.

A xylitol-producer yeast isolated from corn silage and designated as ASM III was selected based on its outstanding biotechnological potential. When cultivated in batch culture mode and keeping the dissolved oxygen at 40% saturation, xylitol production was as high as 130 g l(-1) with a yield of 0.93 g xylitol g(-1) xylose consumed. A preliminary identification of the yeast was performed according to conventional fermentation and assimilation physiological tests. These studies were complemented by using molecular approaches based on PCR amplification, restriction-fragment length polymorphism analysis and sequencing of the rDNA segments: intergenic transcribed spacer (ITS) 1-5.8S rDNA-ITS 2, and D1/D2 domain of the 26S rRNA gene. Results from both the conventional protocols and the molecular characterization, and proper comparisons with the reference strains Candida tropicalis ATCC 20311 and NRRL Y-1367, led to the identification of the isolate as a new strain of C. tropicalis.

Taponamiento cardiaco en neonatos con catéter venoso central y alimentación parenteral / Neonatal cardiac tamponade, central venous catheter and parenteral nutrition

Objetivo: Llamar la atención sobre una entidad poco frecuente o poco informada pero con alta letalidad y que por lo tanto debe considerarse para su detección y tratamiento oportuno en todo neonato críticamente enfermo con alimentación parenteral por catéter venoso central. Reporte de casos: Se trató de dos neonatos, uno de término y otro de pretérmino con catéter venoso central y alimentación parenteral que presentaron deterioro súbito y muerte, secundario a taponamiento cardiaco. Discusión: El taponamiento cardiaco secundario a la instalación de un catéter venoso central es una entidad poco señalada en la literatura nacional e internacional. La incidencia estimada varío de 0.3 por ciento hasta 2 por ciento con letalidad de 74 a 100 por ciento por lo que su sospecha, diagnóstica y manejo temprano son imperativos (si se pretende evitar la muerte) e incrementar la sobrevida de estos neonatos

Rabdomioma cardiaco neonatal: Informe de uncaso y consideraciones clínico-epidemiológicas / Neonatal rhabdomyoma of the heart: case report and clinico epidemiological considerations

Los tumores cardiacos primarios son entidades raras en todos los grupos de edad, de ellos el más frecuente en la edad pediátrica es el rabdomioma, el cual se encuentra asociado a esclerosis tuberosa en el 37 a 80 por ciento de los casos, con una frecuencia informada de hasta 1 por cada 40,000 recién nacidos vivos. El presente caso es el de un recién nacido, que desde las primeras horas de vida presentó soplo pansistólico, cardiomegalia grado IV, datos electrocardiográficos de hipertrofia ventricular e insuficiencia cardiaca. El ecocardiograma y la imagen por resonancia magnética mostraron múltiples tumores en la porción muscular del septum y paredes ventriculares. La biopsia confirmó el diagnóstico de rabdomioma. Lo que, aunado a las máculas hipomelanóticas, áreas de hipodensidad del parénquima cerebral y crisis convulsivas, permitió establecer el diagnóstico de esclerosis tuberosa. En nuestro medio existe poca información sobre ambas enfermedades, por lo que se revisa la incidencia, diagnóstico, pronóstico y manejo de casos como el presente