Actividad glicosidásica de bacterias ácido lácticas (BAL) y bifidobacterias aisladas de leche materna

Trabajo presentado en la VI Jornadas Complutenses, V Congreso Nacional de Investigación para Alumnos de Pregrado en Ciencias de aa Salud y X Congreso de Ciencias Veterinarias y Biomédicas.Las bacterias ácido lácticas (BAL) y las bifidobacterias tienen una gran importancia por su carácter probiótico. El interés por estos microorganismos ha fomentado su aislamiento de diversas fuentes y el estudio de sus propiedades, siendo la actividad glicosídica una de las menos estudiadas.Peer Reviewe

Direct Zinc Determination in Brazilian Sugar Cane Spirit by Solid-Phase Extraction Using Moringa oleifera Husks in a Flow System with Detection by FAAS

This paper reports a method for the determination of zinc in Brazilian sugar cane spirit, (cachaça in Portuguese), using solid-phase extraction with a flow injection analysis system and detection by FAAS. The sorbent material used was activated carbon obtained from Moringa oleifera husks. Flow and chemical variables of the proposed system were optimized through multivariate designs. The factors selected were sorbent mass, sample pH, sample flow rate, and eluent concentration. The optimum extraction conditions were obtained using a sample pH of 4.0, a sample flow rate of 6.0 mL min−1, 30.0 mg of sorbent mass, and 1.0 mol L−1 HNO3 as the eluent at a flow rate of 4.0 mL min−1. The limit of detection for zinc was 1.9 μg L−1, and the precision was below 0.82% (20.0 μg L−1, n = 7). The analytical curve was linear from 2 to 50 μg L−1, with a correlation coefficient of 0.9996. The method developed was successfully applied to spiked Brazilian sugar cane spirit, and accuracy was assessed through recovery tests, with results ranging from 83% to 100%

Efecto de la adición de antioxidantes sobre la motilidad espermática post-criopreservación y fertilidad del semen de peces

La criopreservación de semen produce daños celulares a nivel de membranas plasmáticas, mitocondria y ADN, debido principalmente a la formación de cristales de hielo intra y extracelulares, así como al estrés osmótico y oxidativo generado. Para minimizar estos daños se utilizan medios diluyentes que simulan las características fisiológicas del semen y contienen sustancias crioprotectoras, las cuales con ayuda de algunos antioxidantes proporcionan una mayor supervivencia espermática post-descongelación y mejoría de las tasas de motilidad y fertilidad. La adición de antioxidantes enzimáticos como superóxido dismutasa, catalasa y peróxidasa durante el proceso de criopreservación de células espermáticas en peces, no favorece las tasas de motilidad espermática post-descongelación ni de fertilización en las especies trucha arco iris y de arroyo, mientras que los no enzimáticos (methylenediphosphonic- acid/MDPA, butil-hidroxitolueno/BHT, cisteína, propóleo, ácido ascórbico, lisina y carnitina) las mejoran de forma significativa en especies como esturión beluga, carpa común, esturión ruso y trucha arco iris. Los antioxidantes producen diversos efectos especie-específicos tanto en variables de calidad espermática como fertilidad y su efectividad depende de la concentración y el medio diluyente utilizado. Se concluye que la utilización de antioxidantes no enzimáticos en la criopreservación de semen de especies acuícolas como carpa común, esturión y trucha, resulta indispensable para mejorar la motilidad y fertilidad espermática.

Intervención educativa en salud bucal en niños y maestros

Fundamento: Las pocas posibilidades de acceso a una adecuada atención estomatológica en determinadas comunidades, unidas a la ausencia de programas preventivos, se asocian al deterioro del estado de salud de la población venezolana, en particular de la infantil. Objetivo: evaluar la efectividad de un programa educativo sobre salud bucal para desarrollar cambios de actitud y hábitos bucales saludables. Métodos: se realizó un estudio de intervención en 80 niños y diez maestros, de una escuela de Río Chico, Estado Miranda, Venezuela, en el periodo enero-septiembre de 2010. Se realizó un diagnóstico enfocado al índice de higiene bucal de los niños, y a las necesidades de aprendizaje de estos y sus maestros. Se elaboró un programa que incluyó como medios de enseñanza juegos didácticos y un software educativo. La información se obtuvo por medio de encuestas y grupos focales. Resultados: se obtuvieron diferencias significativas entre el estado inicial y final de los conocimientos y también con respecto al índice de higiene bucal. Quedó evidenciada la aprobación del programa por parte de los niños, quienes consideraron su importancia con respecto a la salud bucal. Conclusión: la intervención, mediante el programa educativo, logró cambios satisfactorios en los modos de actuar y pensar de los niños, en términos de salud bucal, resultados que avalan su validez

Enemies with benefits: parasitic endoliths protect mussels against heat stress

Positive and negative aspects of species interactions can be context dependant and strongly affected by environmental conditions. We tested the hypothesis that, during periods of intense heat stress, parasitic phototrophic endoliths that fatally degrade mollusc shells can benefit their mussel hosts. Endolithic infestation significantly reduced body temperatures of sun-exposed mussels and, during unusually extreme heat stress, parasitised individuals suffered lower mortality rates than nonparasitised hosts. This beneficial effect was related to the white discolouration caused by the excavation activity of endoliths. Under climate warming, species relationships may be drastically realigned and conditional benefits of phototrophic endolithic parasites may become more important than the costs of infestation

Recent Region-wide Declines in Caribbean Reef Fish Abundance

Profound ecological changes are occurring on coral reefs throughout the tropics, with marked coral cover losses and concomitant algal increases, particularly in the Caribbean region. Historical declines in the abundance of large Caribbean reef fishes likely reflect centuries of overexploitation. However, effects of drastic recent degradation of reef habitats on reef fish assemblages have yet to be established. By using meta-analysis, we analyzed time series of reef fish density obtained from 48 studies that include 318 reefs across the Caribbean and span the time period 1955–2007. Our analyses show that overall reef fish density has been declining significantly for more than a decade, at rates that are consistent across all subregions of the Caribbean basin (2.7% to 6.0% loss per year) and in three of six trophic groups. Changes in fish density over the past half-century are modest relative to concurrent changes in benthic cover on Caribbean reefs. However, the recent significant decline in overall fish abundance and its consistency across several trophic groups and among both fished and nonfished species indicate that Caribbean fishes have begun to respond negatively to habitat degradation

A novel μCT analysis reveals different responses of bioerosion and secondary accretion to environmental variability

Corals build reefs through accretion of calcium carbonate (CaCO3) skeletons, but net reef growth also depends on bioerosion by grazers and borers and on secondary calcification by crustose coralline algae and other calcifying invertebrates. However, traditional field methods for quantifying secondary accretion and bioerosion confound both processes, do not measure them on the same time-scale, or are restricted to 2D methods. In a prior study, we compared multiple environmental drivers of net erosion using pre- and post-deployment micro-computed tomography scans (μCT; calculated as the % change in volume of experimental CaCO3 blocks) and found a shift from net accretion to net erosion with increasing ocean acidity. Here, we present a novel μCT method and detail a procedure that aligns and digitally subtracts pre- and post-deployment μCT scans and measures the simultaneous response of secondary accretion and bioerosion on blocks exposed to the same environmental variation over the same time-scale. We tested our method on a dataset from a prior study and show that it can be used to uncover information previously unattainable using traditional methods. We demonstrated that secondary accretion and bioerosion are driven by different environmental parameters, bioerosion is more sensitive to ocean acidity than secondary accretion, and net erosion is driven more by changes in bioerosion than secondary accretion

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients