Methodological Characteristics of the Teaching of Professional Reasoning in Kinesiology: Qualitative Study / Características metodológicas de la enseñanza del razonamiento profesional en kinesiología: Estudio cualitativo / Características metodológicas do ensino do raciocínio profissional em cinesiologia: Estudo qualitativo

Background. The initial training of healthcare professionals has maintained a declared dysfunction since the Alma Ata declaration, which exposed the difficulties of conditioned reasoning due to mimetic assimilation in problem-solving. Objective. To understand the methodological characteristics of the processes used in teaching Professional Reasoning (PR) in Kinesiology students. Methodology. A qualitative interpretive study was conducted using a purposive sampling method, through Semi-Structured Interviews (SSI) with 9 expert teachers (ET) in PR, belonging to accredited universities, using recordings made on the Microsoft TEAMS® platform. These data were collected during 2020-2023 in 5 selected Chilean Kinesiology schools based on curricular evidence and ranking. Results. The emerging themes identified in the interviews with teachers were transcribed and coded using the Atlas.ti® software. It was found that the characteristics of Case Study-Analysis in different applications stood out as the predominant methodology in teaching PR, while the most recurrent assessment instrument was the Rubric. Conclusions. There is a wide range of strategies used by expert ETs to teach PR, which consist of both traditional methodologies and more student-centered active resources, with theoretical and practical aspects characterized by the formative moment, the selected model, and the imprecise taxonomic articulation of strategies and assessment instruments. This highlights the need for a greater integration of factors for the learning of PR.

Antecedentes. La formación inicial de profesionales de la salud ha mantenido una disfunción declarada en Alma Ata que expuso las dificultades del razonamiento condicionado por la asimilación mímica en la resolución de problemas. Objetivo. Conocer las características metodológicas de los procesos que son utilizados en la enseñanza del Razonamiento Profesional (RP) en estudiantes de Kinesiología. Metodología. Estudio cualitativo interpretativo realizado con un muestro razonado, mediante Entrevistas Semiestructuradas (ESE) a 9 docentes referentes (DR), expertos en RP, pertenecientes a universidades acreditadas por medio de grabaciones realizadas en plataforma Microsoft TEAMS®. Estos datos fueron recogidos durante 2020-2023 en 5 escuelas de Kinesiología chilenas seleccionadas por evidencias curriculares y ranking. Resultados. Las temáticas emergentes identificadas en las entrevistas de profesores, fueron transcritas y codificadas utilizando el Software Atlas. ti®. Constatando que las características del Estudio-Análisis de Casos en distintas aplicaciones, se destaca como la metodología predominante en la enseñanza del RP, mientras que el instrumento de evaluación que tuvo mayor recurrencia fue la Rúbrica. Conclusiones:. Existe una variada gama de estrategias utilizadas por DR expertos para enseñar RP las cuales están compuestas por metodologías tradicionales y recursos activos de mayor protagonismo para el estudiante, con vertientes teóricas y prácticas que se caracterizan por el momento formativo, el modelo seleccionado, y la imprecisa articulación taxonómica de estrategias e instrumentos de evaluación lo que advierte respecto de una necesaria mayor integralidad de factores para el aprendizaje del RP.

Enquadramento. A formação inicial dos profissionais de saúde manteve uma disfunção declarada em Alma Ata que expôs as dificuldades de raciocínio condicionadas pela assimilação da mímica na resolução de problemas. Objetivo. Conhecer as características metodológicas dos processos que são utilizados no ensino de Raciocínio Profissional (RP) em alunos de Cinesiologia. Metodologia. Estudo qualitativo interpretativo realizado com uma amostra fundamentada, através de Entrevistas Semiestruturadas (ESE) a 9 professores de referência (DR), especialistas em RP, pertencentes a universidades acreditadas através de gravações efetuadas na plataforma Microsoft TEAMS®. Esses dados foram coletados durante 2020-2023 em 5 escolas chilenas de Cinesiologia selecionadas por evidência curricular e classificação. Resultados. Os temas emergentes identificados nas entrevistas com os professores foram transcritos e codificados com o software Atlas. você®. Observando que pelas características do EstudoAnálise de Casos em diferentes aplicações, destaca-se como a metodologia predominante no ensino de RP, enquanto o instrumento de avaliação que teve maior recorrência foi a Rubrica. Conclusões. Existe uma ampla gama de estratégias utilizadas por especialistas em DR para ensinar RP, que são compostas por metodologias tradicionais e recursos ativos de maior destaque para o aluno, com aspectos teóricos e práticos que se caracterizam pelo momento formativo, o modelo selecionado, e a articulação taxonômica imprecisa de estratégias e instrumentos de avaliação, que alertam para uma maior abrangência necessária de fatores para a aprendizagem de PR.

Incubation in shaded hatcheries biases sex-determination but preserves Lepidochelys olivacea hatchling physiology.

Some studies have associated ex situ conservation with cerebral and gonadal developmental delay, as well as decreased motor performance in Lepidochelys olivacea offspring. Ex situ management is also related to a more mature spleen and a differential leukocyte count in newly emerged Lepidochelys olivacea hatchlings. The physiological relevance of a more mature spleen is unknown in sea turtles, but studies in birds suggest an increased immune response. Because egg relocation to hatcheries is a common conservation practice, it is imperative to know its impact on hatchling physiology. Herein, plasma activity of superoxide dismutase, alkaline phosphatase and the alternative complement pathway, as well as total antioxidant capacity and hydrogen peroxide concentrations were quantified in hatchlings from in situ and ex situ nests under basal conditions at nest emergence. Toll-like receptor 4 (tlr4), heat shock proteins (hsp) 70 and hsp90 expression were quantified in the spleen and liver of the hatchlings. Hepatocyte density and nuclear area were quantified in histological sections of the liver and all turtles were sexed by histological sectioning of the gonads. Total antioxidant capacity and hydrogen peroxide concentrations in plasma were lower in turtles from ex situ nests, while tlr4 and hsp70 mRNA expression was higher in the spleen but not in the liver. Ex situ incubation produced 98% male hatchlings, whereas in situ incubation produced 100% females. There were no other differences in the attributes sampled between hatchlings emerging from ex situ and in situ treatments. The results suggest that ex situ relocated turtles may be less prone to oxidative stress than in situ incubated hatchlings and could have more mature splenic function. Together, the data suggest that ex situ relocation to shaded hatcheries biased sex determination but preserved the general physiological condition of sea turtle hatchlings.

Structural adaptation of fungal cell wall in hypersaline environment.

Halophilic fungi thrive in hypersaline habitats and face a range of extreme conditions. These fungal species have gained considerable attention due to their potential applications in harsh industrial processes, such as bioremediation and fermentation under unfavorable conditions of hypersalinity, low water activity, and extreme pH. However, the role of the cell wall in surviving these environmental conditions remains unclear. Here we employ solid-state NMR spectroscopy to compare the cell wall architecture of Aspergillus sydowii across salinity gradients. Analyses of intact cells reveal that A. sydowii cell walls contain a rigid core comprising chitin, ß-glucan, and chitosan, shielded by a surface shell composed of galactomannan and galactosaminogalactan. When exposed to hypersaline conditions, A. sydowii enhances chitin biosynthesis and incorporates α-glucan to create thick, stiff, and hydrophobic cell walls. Such structural rearrangements enable the fungus to adapt to both hypersaline and salt-deprived conditions, providing a robust mechanism for withstanding external stress. These molecular principles can aid in the optimization of halophilic strains for biotechnology applications.

Consecuencias psicosociales de la pandemia de COVID-19 en estudiantes de Medicina / Psychosocial consequences of the COVID-19 pandemic in medical students

Fundamento: la OMS considera que la amenaza de la COVID-19 y la influencia de las medidas para su prevención están causando un fuerte impacto psicológico en las sociedades. Objetivo: valorar la repercusión de la pandemia de COVID-19 en el orden psicosocial en estudiantes de Medicina de la Facultad de Ciencias Médicas "Julio Trigo López". Métodos: se realizó un estudio descriptivo y transversal en el periodo comprendido entre el 2 de abril-2 de julio de 2021, en la Universidad de Ciencias Médicas de La Habana. Se utilizaron métodos teóricos para la fundamentación de la investigación y empírico: cuestionario a estudiantes de la carrera de Medicina. Se estudiaron las variables: sexo, ansiedad de estado acorde con la escala de ansiedad generalizada y factores que influyeron en los cambios de orden personal. Resultados: hubo predominio del sexo femenino. Se constató que la mayoría (81,7 %) presentó algún grado de ansiedad, con supremacía de la leve, seguida de la moderada, siendo esta última más marcada en el sexo femenino. Como factores generadores de ansiedad, predominó el retraso académico, seguido del temor al contagio e incomprensión por parte de los profesores. Como factores determinantes de cambios en el orden personal, se encontró la influencia de lo emocional dado por cambios en el estilo de vida. Conclusiones: la pandemia de COVID-19 ha causado cambios en el orden personal, psicológico y social en los estudiantes de Medicina, marcados por aspectos relacionados fundamentalmente con las preocupaciones académicas.

Background: WHO considers that the threat of COVID-19 and the influence of its prevention measures are causing a strong psychological impact on societies. Objective: to assess the repercussion of the COVID-19 pandemic in the psychosocial order in Medicine students of the "Julio Trigo López" Faculty of Medical Sciences. Methods: a descriptive and cross-sectional study was carried out from April 2 to July 2, 2021, at Havana University of Medical Sciences. Theoretical methods were used for the foundation of the investigation and empirical ones: questionnaire to students of the Medicine degree. The variables were studied: sex, anxiety according to the generalized anxiety scale and factors that influenced the changes of personal facts. Results: there was a predominance of the female sex. It was found that the majority (81.7%) presented some degree of anxiety, with mild predominance, followed by moderate, the latter being more marked in the female sex. As anxiety-generating factors, academic delay predominated, followed by fear of contagion and misunderstanding by teachers. As determinant factors of changes in the personal order, the influence of the emotional given by changes in lifestyle was found. Conclusions: COVID-19 pandemic has caused changes in the personal, psychological, and social order of medical students, marked by aspects fundamentally related to academic concerns.

Relación del acoso escolar y conductas de riesgo a trastornos de la alimentación en escolares mexicanos / Relationship of school bullying and risk behaviors to eating disorders in Mexican schoolchildren

Fundamentos: El objetivo de la presente investigación fue determinar la prevalencia entre el acoso escolar obullying y las conductas de riesgo a trastornos de la conducta alimentaria (TCA), en escolares mexicanos dequinto y sexto grado escolar. Cuyos resultados aporten al programa en línea que se va diseñar para suprevención.Métodos: Se obtuvo una muestra de 3641 escolares mexicanos entre 9-14 años a los cuales, se les aplicó laencuesta Health Behaviour in School-aged Children (HBSC) y el CBCAR, cuestionario diseñado y validado enadolescentes mexicanos, para evaluar las conductas de riego a TCA. Se aplicó la encuesta en línea, con elformato del programa “NutriNet” del Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán(INCMYNSZ), protocolo con el visto bueno de los comités del Instituto y del Hospital General de México.Resultados: Se observó una mayor incidencia de presentar conductas alimentarias de riesgo en escolares queson acosados tanto en los escolares abusadores y en los escolares que participan en pleitos o peleas,observándose diferencia estadística significativa (p ≥ 0,05).Conclusiones: El bullying constituye un factor de riesgo a padecer un trastorno de la conducta alimentaria. (AU)

Background: The aim of this research was to determine the prevalence of bullying and risk behaviors foreating disorders in Mexican schoolchildren in 5th and 6th grade. Whose results contribute to the onlineprogram that will be designed for its prevention.Methods: A sample of 3,641 Mexican schoolchildren between 9-14 years old was obtained. To whom, theHealth Behavior in School-aged Children (HBSC) survey and the CBCAR, a questionnaire designed andvalidated in Mexican adolescents were applied to evaluate risk behaviors to eating disorders. The onlinesurvey was applied, with the format of the "NutriNet" program of the National Institute of Medical Sciencesand Nutrition Salvador Zubiran (INCMYNSZ), protocol with the approval of the committees of the Instituteand the General Hospital of Mexico.Results: A higher incidence of presenting risky eating behaviors was observed in schoolchildren who arebullied both in abusive schoolchildren and in schoolchildren who participate in fights, observing a statisticallysignificant difference (p ≥ 0.05).Conclusions: Bullying is a risk factor for developing an eating disorder. (AU)

Short communication: Ex-situ conservation in hatcheries is associated with spleen development in Lepidochelys olivacea turtle hatchlings.

Ex-situ conservation in hatcheries is a successful strategy for the recovery of sea turtle populations. However, it alters the ontogenesis of the brain and gonads, as well as body size and locomotor performance at nest emergence. Relocation to hatcheries may alter immune system development, since this depends highly on the nest environment. We hypothesized that ex-situ brooding would negatively associate with immune traits of Lepidochelys olivacea. Splenic cytoarchitecture and leukocyte quantification were used as proxies for the immune configuration. Body size, gonadal sex and sand temperature during incubation were determined. Additionally, the success of nest hatching and emergence was quantified. Linear mixed models of splenic cytoarchitecture, leucocyte proportions and body size, using sex and nest type as explanatory variables, evaluated the effects of ex-situ brooding. Generalized linear mixed models using quasibinomial distributions (log link) analyzed effects on hatching and emergence success. Hatchlings from ex-situ nests were heavier, larger and showed a greater spleen-somatic index. They showed more and better defined splenic periarteriolar lymphoid sheaths, as well as a higher proportion of heterophils but less monocytes. Moreover, ex-situ brooding increased hatching and emergence success. Sand temperatures in hatcheries favored male sex determination, while the opposite occurred for in-situ incubation. Interestingly, the immune configuration and body size were independent of sex but associated with ex-situ conservation. Greater body size promotes early hatchling survival, while better spleen development is related to a greater antibody production and a better immune response to pathogens. Altogether, the results suggest that ex-situ incubation is associated with a better immune configuration and higher survival success.

Tracking gene expression, metabolic profiles, and biochemical analysis in the halotolerant basidiomycetous yeast Rhodotorula mucilaginosa EXF-1630 during benzo[a]pyrene and phenanthrene biodegradation under hypersaline conditions.

Polyaromatic phenanthrene (Phe) and benzo[a]pyrene (BaP) are highly toxic, mutagenic, and carcinogenic contaminants widely dispersed in nature, including saline environments. Polyextremotolerant Rhodotorula mucilaginosa EXF-1630, isolated from Arctic sea ice, was grown on a huge concentration range -10 to 500 ppm- of Phe and BaP as sole carbon sources at hypersaline conditions (1 M NaCl). Selected polycyclic aromatic hydrocarbons (PAHs) supported growth as well as glucose, even at high PAH concentrations. Initially, up to 40% of Phe and BaP were adsorbed, followed by biodegradation, resulting in 80% removal in 10 days. While extracellular laccase, peroxidase, and un-specific peroxygenase activities were not detected, NADPH-cytochrome c reductase activity peaked at 4 days. The successful removal of PAHs and the absence of toxic metabolites were confirmed by toxicological tests on moss Physcomitrium patens, bacterium Aliivibrio fischeri, human erythrocytes, and pulmonary epithelial cells (A549). Metabolic profiles were determined at the midpoint of the biodegradation exponential phase, with added Phe and BaP (100 ppm) and 1 M NaCl. Different hydroxylated products were found in the culture medium, while the conjugative metabolite 1-phenanthryl-ß-D-glucopyranose was detected in the medium and in the cells. Transcriptome analysis resulted in 870 upregulated and 2,288 downregulated transcripts on PAHs, in comparison to glucose. Genomic mining of 61 available yeast genomes showed a widespread distribution of 31 xenobiotic degradation pathways in different yeast lineages. Two distributions with similar metabolic capacities included black yeasts and mainly members of the Sporidiobolaceae family (including EXF-1630), respectively. This is the first work describing a metabolic profile and transcriptomic analysis of PAH degradation by yeast.

Neotropical termite microbiomes as sources of novel plant cell wall degrading enzymes.

In this study, we used shotgun metagenomic sequencing to characterise the microbial metabolic potential for lignocellulose transformation in the gut of two colonies of Argentine higher termite species with different feeding habits, Cortaritermes fulviceps and Nasutitermes aquilinus. Our goal was to assess the microbial community compositions and metabolic capacity, and to identify genes involved in lignocellulose degradation. Individuals from both termite species contained the same five dominant bacterial phyla (Spirochaetes, Firmicutes, Proteobacteria, Fibrobacteres and Bacteroidetes) although with different relative abundances. However, detected functional capacity varied, with C. fulviceps (a grass-wood-feeder) gut microbiome samples containing more genes related to amino acid metabolism, whereas N. aquilinus (a wood-feeder) gut microbiome samples were enriched in genes involved in carbohydrate metabolism and cellulose degradation. The C. fulviceps gut microbiome was enriched specifically in genes coding for debranching- and oligosaccharide-degrading enzymes. These findings suggest an association between the primary food source and the predicted categories of the enzymes present in the gut microbiomes of each species. To further investigate the termite microbiomes as sources of biotechnologically relevant glycosyl hydrolases, a putative GH10 endo-ß-1,4-xylanase, Xyl10E, was cloned and expressed in Escherichia coli. Functional analysis of the recombinant metagenome-derived enzyme showed high specificity towards beechwood xylan (288.1 IU/mg), with the optimum activity at 50 °C and a pH-activity range from 5 to 10. These characteristics suggest that Xy110E may be a promising candidate for further development in lignocellulose deconstruction applications.

Metagenomics of Atacama Lithobiontic Extremophile Life Unveils Highlights on Fungal Communities, Biogeochemical Cycles and Carbohydrate-Active Enzymes.

Halites, which are typically found in various Atacama locations, are evaporitic rocks that are considered as micro-scaled salterns. Both structural and functional metagenomic analyses of halite nodules were performed. Structural analyses indicated that the halite microbiota is mainly composed of NaCl-adapted microorganisms. In addition, halites appear to harbor a limited diversity of fungal families together with a biodiverse collection of protozoa. Functional analysis indicated that the halite microbiome possesses the capacity to make an extensive contribution to carbon, nitrogen, and sulfur cycles, but possess a limited capacity to fix nitrogen. The halite metagenome also contains a vast repertory of carbohydrate active enzymes (CAZY) with glycosyl transferases being the most abundant class present, followed by glycosyl hydrolases (GH). Amylases were also present in high abundance, with GH also being identified. Thus, the halite microbiota is a potential useful source of novel enzymes that could have biotechnological applicability. This is the first metagenomic report of fungi and protozoa as endolithobionts of halite nodules, as well as the first attempt to describe the repertoire of CAZY in this community. In addition, we present a comprehensive functional metagenomic analysis of the metabolic capacities of the halite microbiota, providing evidence for the first time on the sulfur cycle in Atacama halites.

A Review on Viral Metagenomics in Extreme Environments.

Viruses are the most abundant biological entities in the biosphere, and have the ability to infect Bacteria, Archaea, and Eukaryotes. The virome is estimated to be at least ten times more abundant than the microbiome with 107 viruses per milliliter and 109 viral particles per gram in marine waters and sediments or soils, respectively. Viruses represent a largely unexplored genetic diversity, having an important role in the genomic plasticity of their hosts. Moreover, they also play a significant role in the dynamics of microbial populations. In recent years, metagenomic approaches have gained increasing popularity in the study of environmental viromes, offering the possibility of extending our knowledge related to both virus diversity and their functional characterization. Extreme environments represent an interesting source of both microbiota and their virome due to their particular physicochemical conditions, such as very high or very low temperatures and >1 atm hydrostatic pressures, among others. Despite the fact that some progress has been made in our understanding of the ecology of the microbiota in these habitats, few metagenomic studies have described the viromes present in extreme ecosystems. Thus, limited advances have been made in our understanding of the virus community structure in extremophilic ecosystems, as well as in their biotechnological potential. In this review, we critically analyze recent progress in metagenomic based approaches to explore the viromes in extreme environments and we discuss the potential for new discoveries, as well as methodological challenges and perspectives.

Biochemical Characterization of a Novel Monospecific Endo-ß-1,4-Glucanase Belonging to GH Family 5 From a Rhizosphere Metagenomic Library.

Cellulases have a broad range of different industrial applications, ranging from food and beverages to pulp and paper and the biofuels area. Here a metagenomics based strategy was used to identify the cellulolytic enzyme CelRH5 from the rhizosphere. CelRH5 is a novel monospecific endo-ß-1,4-glucanase belonging to the glycosyl hydrolase family 5 (GH5). Structural based modeling analysis indicated that CelRH5 is related to endo-ß-1,4-glucanases derived from thermophilic microorganisms such as Thermotoga maritima, Fervidobacterium nodosum, and Ruminiclostridium thermocellum sharing 30-40% amino acid sequence identity. The molecular weight of the enzyme was determined as 40.5 kDa. Biochemical analyses revealed that the enzyme displayed good activity with soluble forms of cellulose as a substrate such as ostazin brilliant red hydroxyethyl cellulose (OBR-HEC), carboxymethylcellulose (CMC), hydroxyethyl cellulose (HEC), and insoluble azurine cross-linked hydroxyethylcellulose (AZCL-HEC). The enzyme shows highest enzymatic activity at pH 6.5 with high pH tolerance, remaining stable in the pH range 4.5-8.5. Highest activity was observed at 40°C, but CelRH5 is psychrotolerant being active and stable at temperatures below 30°C. The presence of the final products of cellulose hydrolysis (glucose and cellobiose) or metal ions such as Na+, K+, Li+, and Mg2+, as well as ethylenediaminetetraacetic acid (EDTA), urea, dithiothreitol (DTT), dimethyl sulfoxide (DMSO), 2-mercaptoethanol (2-ME) or glycerol, did not have a marked effect on CelRH5 activity. However, the enzyme is quite sensitive to the presence of 10 mM ions Zn2+, Ni2+, Co2+, Fe3+ and reagents such as 1 M guanidine HCl, 0.1% sodium dodecyl sulfate (SDS) and 20% ethanol. Given that it is psychrotolerant and retains activity in the presence of final cellulose degradation products, metal ions and various reagents, which are common in many technological processes; CelRH5 may be potential suitability for a variety of different biotechnological applications.

Patrones de crianza y cuidado de niños y niñas en Boyacá / Padrões de criação e cuidado de meninos e meninas no Estado de Boyacá / Boys and girls’ rearing and care patterns in the Province of Boyacá

En este artículo hacemos referencia a los resultados del autodiagnóstico comunitario sobrecomportamientos, actitudes y patrones de crianza –CAP–, realizado a través de cinco talleres con cuidadorasy cuidadores de niños y niñas menores de cinco años, y con las enfermeras y enfermeros jefes de la EmpresaSocial del Estado –ESE–, en 78 municipios del departamento de Boyacá (Colombia). Las participantes ylos participantes narran rutinas diarias en el ejercicio y prácticas del cuidado. A partir de referentes teóricoconceptualessobre familia y socialización, interpretamos las prácticas de crianza que subsisten en las familias desectores populares y rurales.

Este artigo apresenta os resultados do auto-diagnóstico comunitário sobre comportamentos,atitudes e padrões de educação – CAP – realizado através de cinco workshops com cuidadores e cuidadoras decrianças menores de cinco anos e com as enfermeiras-chefes das Empresas Sociais do Estado – ESSE – em 78municipalidades do departamento de Boyacá (Colômbia). Tanto os como as participantes descrevem as rotinasdiárias no exercício e práticas de cuidado das crianças. A partir de referentes teórico-conceituais sobre a famíliae o processo de socialização, interpretam-se as práticas de educação existentes nas famílias dos setores popularese rurais.

This article refers to the results from the community self-diagnosis on behaviors, attitudes andrearing patterns – CAP – resulting from five workshops conducted with male and female caregivers of boys andgirls under five years and the chief nurses of State-Owned Social Enterprises - ESE- in 78 municipalities of theProvince of Boyacá, Colombia. Both the male and female participants describe the daily routines concerningtheir care-giving practices. From theoretical-conceptual referents concerning family and socialization, the childrearingpractices surviving in the families of both popular and rural sectors are interpreted.

Effects of diterpenes from latex of Euphorbia lactea and Euphorbia laurifolia on human immunodeficiency virus type 1 reactivation.

The persistence of latent HIV-infected cellular reservoirs represents the major hurdle to virus eradication in patients treated with highly active antiretroviral therapy, referred to as HAART. HIV-1 reservoirs are long-lived resting CD4+ memory cells containing the virus latently integrated. Since the HIV-1 reservoirs are not targeted by HAART, reactivation therapy has been suggested to purge viral latency. Bioassay-guided study of an ethyl acetate extract of Euphorbia laurifolia afforded two isomeric diterpenes that showed differential activity over HIV-1 reactivation. A previously reported compound was isolated too from Euphorbia lactea. This compound showed a potent HIV-1 reactivating effect. Bioassays results showed that HIV-1 reactivation activity is influenced by distinct structural characteristics.

Enfermedad de creutzfeldt-jakob. Presentación de un caso / Creutzfeldt-jakob disease. A case report

La enfermedad de Creutzfeld-Jakob es una enfermedad degenerativa subaguda del encéfalo clasificada dentro de las encefalopatías espongiformes transmisibles. La incidencia en el mundo entero es de 1 /1 millón. En la Argentina, no existen datos para evaluación de incidencia ni mortalidad. Desde 1945 a 1997 se informaron 50 casos confirmados con anatomía patológica. La edad promedio de los pacientes afectados fue de 55, 8 años. La relación hombre-mujer fue 1:0,70 . Se presenta el caso clínico de una mujer de 72 años ,que comienza 40 días previos al ingreso con diplopía, alteraciones en el campo visual y en la visión en colores, acúfenos, cambios en la conducta y alteraciones del ritmo sueño-vigilia. Luego se agregan alteraciones en la marcha, desviaciones posturales y debilidad de miembros inferiores hasta llegar a la postración. Se interpreta el cuadro como demencia subaguda con etiología desconocida. La RMI de cerebro mostró lesiones focales difusas en sustancia blanca; el EEG complejos de 1/segundo periódicas, difusamente distribuidas, por lo que se sospecha encefalopatía espongiforme de Creutzfeldt-Jakob. La determinación de proteína 14-3-3 en líquido cefalorraquídeo, fué positiva. Se realiza tratamiento de sostén, presentando estabilidad inicial, pero desarrolla en forma posterior una neumonía intrahospitalaria y fallece. Se toma biopsia cerebral post mortem donde se observan cambios espongiformes en todas las capas, con lo que se obtiene diagnóstico definitivo. Se presenta dicho caso por su baja frecuencia de presentación y la complejidad del diagnóstico diferencial de las demencias subagudas.

Creufeldt-Jakob disease is a transmissible spongiform encephalopathy (TSE) that affects the CNS with no treatment and ominous prognosis in less than a year. It may occur in an inherited, infectious or sporadic form with a prevalence of less than 1 case/per million worldwide.There are no exact data in Argentina on the incidence or mortality of this disease, but between 1945 and 1997, 50 cases were confirmed either by biopsy or autopsy. It affects patients in their fifties (mean 55.8 years) with a slight prevalence in men (1:0.7). The clinical case of a 72 year old woman is presented here. Symptoms started 40 days before being admitted at the hospital with diplopia, visual field and color vision alterations, acufens, behavioral changes, and sleep/wake rhythm alterations. Later, walking alterations, postural deviations, and weakness in lower limbs appeared leading to patient postration. The case is interpreted as sub-acute dementia of unknown etiology. The brain MRI scan showed diffused white-matter focal lesions; the EEG showed periodic 1/second, diffusely distributed complexes, thus Creutzfeldt-Jakob spongiform encephalopathy is suspected. Protein 14-3-3 determination in cerebroespinal fluid was positive. Support treatment is carried out, showing initial stability; however, the patient later develops intra-hospital pneumonia and dies. A brain biopsy is performed and spongiform changes are observed in all the layers, thus obtaining the final diagnosis. This case is presented because of its low occurrence and the complexity of differential diagnosis of sub-acute dementias.

In vitro anti-influenza screening of several Euphorbiaceae species: structure of a bioactive Cyanoglucoside from Codiaeum variegatum.

A bio-guided screening against influenza A virus (FLUAV) was carried out with seven Euphorbiaceae species. The results showed that chromatographic fractions from Phyllantus niruri, Euphorbia pulcherrima and Codiaeum variegatum had relevant anti-FLUAV activity, although only chromatographical subfractions from C. variegatum kept the activity. From this plant, the active compound against FLUAV was isolated. Its structure was assigned as 2-(3,4,5)-trihydroxy-6-hydroxymethyltetrahydropyran-2-yloxymethyl)acrylonitrile (1) on the basis of NMR, mass spectrometry and X-ray diffraction analysis. The compound displayed virucidal activity without impairment of haemagglutination properties of the used virus strain. This is the first report indicating antiviral activity of a cyanoglucoside.

Efecto citopatogénico de la exotoxina diftérica en cultivos celulares de fibroblastos de embrión de pollo / Cytopathogenic effect of diphtheriae exotoxin in chicken embryo fibroblast culture

Se estudiaron 150 cepas de Corynebacterium diphtheriae obtenidas de pacientes con clínica de diftéria y de portadores sanos. De las mismas 136(90.67%) pertenecían al biotipo mitis, 12(8,00%) y 2(1,33%) a los biotipos gravis e intermedius respectivamente. Se determinó la toxigenicidad por los métodos tradicionales in vivo empleando conejos machos blancos e in vitro por la metodología de inmunodifusión en placas conteniendo medio de K.L. virulencia. de las 136 cepas del biotipo mitis, 130(95,58%) demostraron toxigenicidad positiva por ambos métodos; 11(91,66%) del biotipo gravis y las 2(100%) del biotipo intermedius igualmente dieron toxigenicidad por los métodos empleados. Se determinó también citotoxigenicidad en cultivos celulares de fibroblastos de embrión de pollo, los resultados obtenidos con esta metodología dieron citotoxicidad positiva en 132(97,05%) de las cepas agrupadas en el biotipo mitis, las 12(100%) del biotipo gravis y las 2(100%) del biotipo intermedius. Estos resultados indicaron que la citotoxicidad parece ser un método más sensible para la detección de la producción de exotoxina diftérica