43 research outputs found
The interaction of Bacillus protoplasts with sonicated phosphatidylcholine liposomes
AbstractWhen protoplasts from Bacillus subtilis are incubated with sonicated liposomes made from egg-yolk phosphatidylcholine, this phospholipid is incorporated into the protoplast membranes. Biochemical, fluorescence and ultrastructural data suggest that incorporation occurs through membrane fusion
The neural substrate and functional integration of uncertainty in decision making: an information theory approach
Decision making can be regarded as the outcome of cognitive processes leading to the selection of a course of action among several alternatives. Borrowing a central measurement from information theory, Shannon entropy, we quantified the uncertainties produced by decisions of participants within an economic decision task under different configurations of reward probability and time. These descriptors were used to obtain blood oxygen level-dependent (BOLD) signal correlates of uncertainty and two clusters codifying the Shannon entropy of task configurations were identified: a large cluster including parts of the right middle cingulate cortex (MCC) and left and right pre-supplementary motor areas (pre-SMA) and a small cluster at the left anterior thalamus. Subsequent functional connectivity analyses using the psycho-physiological interactions model identified areas involved in the functional integration of uncertainty. Results indicate that clusters mostly located at frontal and temporal cortices experienced an increased connectivity with the right MCC and left and right pre-SMA as the uncertainty was higher. Furthermore, pre-SMA was also functionally connected to a rich set of areas, most of them associative areas located at occipital and parietal lobes. This study provides a map of the human brain segregation and integration (i.e., neural substrate and functional connectivity respectively) of the uncertainty associated to an economic decision making paradigm
El gen tpi como herramienta en los estudios epidemioloÂŽgicos de la giardiosis
Giardia duodenalis es un protozoo que causa infecciĂłn en humanos y animales, que se puede transmitir por vĂa hĂdrica, de persona a persona o por contacto con animales, siendo una de las infecciones intestinales mĂĄs frecuentes en nuestro paĂs, por lo que supone una preocupaciĂłn de Salud PĂșblica. Su estudio epidemiolĂłgico, requiere la caracterizaciĂłn molecular de los parĂĄsitos, utilizando genes con gran variabilidad como el que codifica la triosafosfatoisomerasa (tpi) y analizando la homologĂa entre aislamientos.
El objetivo del trabajo es establecer el criterio de identidad que permita la comparaciĂłn epidemiolĂłgica de los aislamientos de Giardia.
Se recogieron 2-3 muestras de heces en dĂas alternos, de 26 pacientes con giardiosis. Tras la extracciĂłn de ADN, se amplificaron por tĂ©cnicas de PCR, un fragmento del gen tpi y un fragmento del gen de la beta-giardina (bg), que se utilizĂł como comparaciĂłn. Los fragmentos obtenidos fueron secuenciados y las secuencias analizadas con los programas BioEdit y DnaSP v.5.0. Las secuencias del gen tpi mostraron una elevada divergencia, con valores de diversidad Âż entre 0 y 0, 21219. La apariciĂłn de picos mĂșltiples en el cromatograma, indicaron la presencia de varios clones en la misma muestra. Las diferencias entre aislamientos del mismo paciente fueron iguales o mayores que las encontradas para el conjunto de todas las muestras.
La variabilidad del gen tpi no permite establecer unos criterios de identidad, necesarios para la identificaciĂłn de aislamientos.
Las infecciones mixtas intragenotipo ocurren de una forma muy frecuente, sugiriendo una implicaciĂłn de la vĂa ambiental como principal fuente de transmisiĂłn o una variaciĂłn genĂ©tica muy elevada.
Giardia duodenalis is a protozoon that causes infection in humans and animals. It can be transmitted by contaminated water, from person to person or by contact with animals; it being the cause one of the most common intestinal infections in our country, so it is a public health concern. The epidemiological study thereof requires the molecular characterization of parasites, using genes with great variability, such as the one that codes triosephosphate isomerase (tpi), and analizing the homology between isolates. The purpose of this work is to establish the identity criterion for epidemiological comparison of Giardia isolates. 2-3 stool samples were collected in alternate days from 26 patients with giardiasis. After DNA extraction, a fragment of the tpi gene and a fragment of the beta-giardin (bg) gene-used for comparison purposes-were amplified by means of PCR techniques. The obtained fragments were sequenced and the sequences analyzed with the BioEdit and DnaSP v.5.0 software. The tpi gene sequences showed a high divergence, with values of diversity Âż ranging from 0 to 0.21219. The appearance of multiple peaks in the chromatogram points to the presence of various clones in the same sample. The differences between isolates from the same patient where equal or higher than those found for the collection of all samples. The variability of the tpi gene does not allow identity criteria to be established, which are necessary for isolate identification. Mixed intragenotype infections occur very frequently, which suggests the environmental path is the principal path of transmission and/or there is very high genetic variability
Impairment of pre-mRNA splicing in liver disease: mechanisms and consequences
Pre-mRNA splicing is an essential step in the process
of gene expression in eukaryotes and consists of the
removal of introns and the linking of exons to generate
mature mRNAs. This is a highly regulated mechanism
that allows the alternative usage of exons, the retention
of intronic sequences and the generation of exonic se-
quences of variable length. Most human genes undergo
splicing events, and disruptions of this process have
been associated with a variety of diseases, including
cancer. Hepatocellular carcinoma (HCC) is a molecularly
heterogeneous type of tumor that usually develops in a
cirrhotic liver. Alterations in pre-mRNA splicing of some
genes have been observed in liver cancer, and although
still scarce, the available data suggest that splicing de-
fects may have a role in hepatocarcinogenesis. Here
we briefly review the general mechanisms that regulate
pre-mRNA splicing, and discuss some examples that
illustrate how this process is impaired in liver tumori-
genesis, and may contribute to HCC development. We
believe that a more thorough examination of pre-mRNA
splicing is still needed to accurately draw the molecular
portrait of liver cancer. This will surely contribute to a
better understanding of the disease and to the develop-
ment of new effective therapies
Splicing regulator SLU7 is essential for maintaining liver homeostasis
A precise equilibrium between cellular differentiation and proliferation is fundamental for tissue homeostasis.
Maintaining this balance is particularly important for the liver, a highly differentiated organ with systemic
metabolic functions that is endowed with unparalleled regenerative potential. Carcinogenesis in the liver
develops as the result of hepatocellular de-differentiation and uncontrolled proliferation. Here, we identified
SLU7, which encodes a pre-mRNA splicing regulator that is inhibited in hepatocarcinoma, as a pivotal gene
for hepatocellular homeostasis. SLU7 knockdown in human liver cells and mouse liver resulted in profound
changes in pre-mRNA splicing and gene expression, leading to impaired glucose and lipid metabolism, refractoriness
to key metabolic hormones, and reversion to a fetal-like gene expression pattern. Additionally, loss of
SLU7 also increased hepatocellular proliferation and induced a switch to a tumor-like glycolytic phenotype.
Slu7 governed the splicing and/or expression of multiple genes essential for hepatocellular differentiation,
including serine/arginine-rich splicing factor 3 (Srsf3) and hepatocyte nuclear factor 4α (Hnf4α), and was critical
for cAMP-regulated gene transcription. Together, out data indicate that SLU7 is central regulator of hepatocyte
identity and quiescence
Uso dos fenóis da lignina no estudo da matéria orgùnica na vårzea do Lago Grande Curuåi, Parå e no Lago do Caçó, Maranhão, Brasil
Ação de fungos entomopatogĂȘnicos em larvas e adultos da mosca do figo Zaprionus indianus (Diptera: Drosophilidae)
Conversion to drip irrigated agriculture may offset historic anthropogenic and wildfire contributions to sediment production
This study is an investigation into the roles of wildfire and changing agricultural practices in controlling the inter-decadal scale trends of suspended sediment production from semi-arid mountainous rivers. In the test case, a decreasing trend in suspended sediment concentrations was found in the lower Salinas River, California between 1967 and 2011. Event to decadal scale patterns in sediment production in the Salinas River have been found to be largely controlled by antecedent hydrologic conditions. Decreasing suspended sediment concentrations over the last 15years of the record departed from those expected from climatic/hydrologic forcing. Sediment production from the mountainous headwaters of the central California Coast Ranges is known to be dominated by the interaction of wildfire and large rainfall/runoff events, including the Arroyo Seco, an ~700km(2) subbasin of the Salinas River. However, the decreasing trend in Salinas River suspended sediment concentrations run contrary to increases in the watershed's effective burn area over time. The sediment source area of the Salinas River is an order of magnitude larger than that of the Arroyo Seco, and includes a more complicated mosaic of land cover and land use. The departure from hydrologic forcings on suspended sediment concentration patterns was found to coincide with a rapid conversion of irrigation practices from sprinkler and furrow to subsurface drip irrigation. Changes in agricultural operations appear to have decreased sediment supply to the Salinas River over the late 20th to early 21st centuries, obscuring the influence of wildfire on suspended sediment production
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Dietary αâLinolenic Acid, Marine Ïâ3 Fatty Acids, and Mortality in a Population With High Fish Consumption: Findings From the PREvenciĂłn con DIeta MEDiterrĂĄnea (PREDIMED) Study
Background: Epidemiological evidence suggests a cardioprotective role of αâlinolenic acid (ALA), a plantâderived Ïâ3 fatty acid. It is unclear whether ALA is beneficial in a background of high marine Ïâ3 fatty acids (longâchain nâ3 polyunsaturated fatty acids) intake. In persons at high cardiovascular risk from Spain, a country in which fish consumption is customarily high, we investigated whether meeting the International Society for the Study of Fatty Acids and Lipids recommendation for dietary ALA (0.7% of total energy) at baseline was related to allâcause and cardiovascular disease mortality. We also examined the effect of meeting the society's recommendation for longâchain nâ3 polyunsaturated fatty acids (â„500 mg/day). Methods and Results: We longitudinally evaluated 7202 participants in the PREvenciĂłn con DIeta MEDiterrĂĄnea (PREDIMED) trial. Multivariableâadjusted Cox regression models were fitted to estimate hazard ratios. ALA intake correlated to walnut consumption (r=0.94). During a 5.9ây followâup, 431 deaths occurred (104 cardiovascular disease, 55 coronary heart disease, 32 sudden cardiac death, 25 stroke). The hazard ratios for meeting ALA recommendation (n=1615, 22.4%) were 0.72 (95% CI 0.56â0.92) for allâcause mortality and 0.95 (95% CI 0.58â1.57) for fatal cardiovascular disease. The hazard ratios for meeting the recommendation for longâchain nâ3 polyunsaturated fatty acids (n=5452, 75.7%) were 0.84 (95% CI 0.67â1.05) for allâcause mortality, 0.61 (95% CI 0.39â0.96) for fatal cardiovascular disease, 0.54 (95% CI 0.29â0.99) for fatal coronary heart disease, and 0.49 (95% CI 0.22â1.01) for sudden cardiac death. The highest reduction in allâcause mortality occurred in participants meeting both recommendations (hazard ratio 0.63 [95% CI 0.45â0.87]). Conclusions: In participants without prior cardiovascular disease and high fish consumption, dietary ALA, supplied mainly by walnuts and olive oil, relates inversely to allâcause mortality, whereas protection from cardiac mortality is limited to fishâderived longâchain nâ3 polyunsaturated fatty acids. Clinical Trial Registration URL: http://www.Controlled-trials.com/. Unique identifier: ISRCTN35739639
El inmigrante en la consulta de atenciĂłn primaria
En las consultas de los centros de salud, el mĂ©dico de familia, el pediatra y el personal de enfermerĂa se han encontrado, sobre todo desde finales del s. XIX y en lo que va del s. XXI, con la realidad de tener que atender a una numerosa poblaciĂłn compuesta de personas desarraigadas de su comunidad, la mayorĂa de las veces sin familia cercana, con unas lenguas y culturas diferentes, con un modo distinto de entender la salud y la enfermedad. Este artĂculo pretende ser una aproximaciĂłn al anĂĄlisis de este fenĂłmeno y contribuir a que los profesionales sanitarios puedan entender y mejorar la atenciĂłn al paciente inmigrante