229 research outputs found
First record of ectoparasites in five lizard species of the genus Liolaemus (Liolaemidae) and in Teius teyou (Teiidae)
Ectoparasites of the Trombiculidae family and the genus Neopterygosoma were identified in six lizard species from north-western and central-western Argentina, Liolaemus ramirezae, L. scapularis, L. cuyanus, L. olongasta, L. riojanus and Teius teyou. Description of their distribution on the host body are provided. The highest intensity of infestation was recorded in the eyelids, armpits and belly. This work constitutes a new host registry for trombiculid and Neopterygosoma mites.Asociación Herpetológica Argentin
Molecular analysis reveals heterogeneity of mouse mammary tumors conditionally mutant for Brca1
<p>Abstract</p> <p>Background</p> <p>Development of therapies for patients with BRCA1 mutations has been hampered by lack of readily available <it>in vitro </it>and <it>in vivo </it>models. We recently showed that transplantation of transgenic mammary tumors as cell suspensions into naïve recipients generates reproducible tumors with remarkable stability of gene expression profile. We examined the expression profiles of original and serially transplanted mammary tumors from <it>Brca1 </it>deficient mice, and tumor derived cell lines to validate their use for preclinical testing and studies of tumor biology.</p> <p>Methods</p> <p>Original tumors, serially transplanted and multiple cell lines derived from <it>Brca1 </it>mammary tumors were characterized by morphology, gene and protein expression, and cell surface markers.</p> <p>Results</p> <p>Gene expression among <it>Brca1 </it>tumors showed more heterogeneity than among previously characterized tumors from MMTV-<it>PyMT </it>and -<it>Wnt1 </it>models. Gene expression data segregated <it>Brca1 </it>tumors into 3 distinct types: basal, mixed luminal, and tumors with epithelial-to-mesenchymal transition (EMT). Serial transplantation of individual tumors and multiple cell lines derived from the original tumors recapitulated the molecular characteristics of each tumor of origin. One tumor had distinct features of EMT and gave rise to cell lines that contained a distinct CD44<sup>+</sup>/CD24<sup>-/low </sup>population that may correlate with human breast cancer stem cells.</p> <p>Conclusion</p> <p>Although individual tumors expanded by transplantation maintain the genomic profile of the original tumors, the heterogeneity among <it>Brca1 </it>tumors limits the extent of their use for preclinical testing. However, cell lines offer a robust material for understanding tumor biology and response to therapies driven by BRCA1 deficiency.</p
Effect of Probiotics on Host-Microbiota in Bacterial Infections
Diseases caused by bacteria cause millions of deaths every year. In addition, the problem of
resistance to antibiotics is so serious that it threatens the achievements of modern medicine. This is a
very important global problem as some bacteria can also develop persistence. Indeed, the persistence
of pathogenic bacteria has evolved as a potent survival strategy to overcome host organisms’ defense
mechanisms. Additionally, chronic or persistent infections may be caused by persisters which could
facilitate antibiotic resistance. Probiotics are considered good bacteria. It has been described that the
modulation of gut microbiota by probiotics could have a great potential to counteract the deleterious
impact and/or regulate gut microbiota after bacterial infection. Probiotics might provide health
benefits through the inhibition of pathogen growth or the replacement of pathogenic bacteria. Bearing
in mind that current strategies to avoid bacterial persistence and prevent antibiotic resistance are not
effective, other strategies need to be assessed. We have carried out a comprehensive review, which
included the reported literature between 2016 and 2021, highlighting the clinical trials that reported
the probiotics’ potential to regulate gut microbiota after bacterial infection and focusing in particular
on the context of antibiotic resistance and persister cells.Regional Ministry of Health and Families (Andalucia, Spain) RPS 2466
SPECTROMETRY ANALYSIS TECHNIQUES FOR LCT PEGMATITE HALO IDENTIFICATION: THE ROLE OF EUROPEAN PROJECTS
Lithium-Cesium-Tantalum ( LCT) pegmatites are enriched in several raw materials. However, their small size and the limited penetration depth of the sensors, limits remote sensing approaches. This study evaluates the usefulness of hyperspectral data to identify geochemical halos related to LCT pegmatites by exploiting the information acquired in European projects. It was possible to identify key minerals and related mineralogical changes that can be due to hydrothermal alteration. Partial Least Squares Regression (PLSR) was used to model the abundance of Li, Rb and Cs. The most reliable results were obtained for Cs, with results being influenced by lithological and weathering factors. New outcomes are expected, namely mineral chemistry studies that will complement the hyperspectral results
Expression of miR159 is altered in tomato plants undergoing drought stress
In a scenario of global climate change,water scarcity is amajor threat for agriculture, severely limiting crop yields. Therefore, alternatives are urgently needed for improving plant adaptation to drought stress. Among them, gene expression reprogramming by microRNAs (miRNAs) might offer a biotechnologically sound strategy. Drought-responsive miRNAs have been reported in manyplant species, and some of them are known to participate in complex regulatory networks via their regulation of transcription factors involved in water stress signaling. We explored the role of miR159 in the response of Solanum lycopersicum Mill. plants to drought stress by analyzing the expression of sly-miR159 and its target SlMYB transcription factor genes in tomato plants of cv. Ailsa Craig grown in deprived water conditions or in response to mechanical damage caused by the Colorado potato beetle, a devastating insect pest of Solanaceae plants. Results showed that sly-miR159 regulatory function in the tomato plants response to distinct stresses might be mediated by differential stress-specific MYB transcription factor targeting. sly-miR159 targeting of SlMYB33 transcription factor transcript correlated with accumulation of the osmoprotective compounds proline and putrescine, which promote drought tolerance. This highlights the potential role of sly-miR159 in tomato plants' adaptation to water deficit conditions
Functional interaction between BLM helicase and 53BP1 in a Chk1-mediated pathway during S-phase arrest
Bloom's syndrome is a rare autosomal recessive genetic disorder characterized by chromosomal aberrations, genetic instability, and cancer predisposition, all of which may be the result of abnormal signal transduction during DNA damage recognition. Here, we show that BLM is an intermediate responder to stalled DNA replication forks. BLM colocalized and physically interacted with the DNA damage response proteins 53BP1 and H2AX. Although BLM facilitated physical interaction between p53 and 53BP1, 53BP1 was required for efficient accumulation of both BLM and p53 at the sites of stalled replication. The accumulation of BLM/53BP1 foci and the physical interaction between them was independent of γ-H2AX. The active Chk1 kinase was essential for both the accurate focal colocalization of 53BP1 with BLM and the consequent stabilization of BLM. Once the ATR/Chk1- and 53BP1-mediated signal from replicational stress is received, BLM functions in multiple downstream repair processes, thereby fulfilling its role as a caretaker tumor suppressor
Creació de vídeos de tècniques de bioquímica i de bases de dades de preguntes comentades
El treball dut a terme s'emmarca en un objectiu general de producció de materials perquè s'utilitzin com a eines per afavorir l'autoaprenentatge en un entorn de docència semipresencial. S'han fet dos vídeos de dues tècniques experimentals fonamentals en bioquímica: la cromatografia i la fixació de radiolligands. Ambdós vídeos corresponen a la filmació d'experiments que implicaven manipulacions sofisticades i es van dur a terme en els laboratoris docents de la Unitat de Bioquímica de Medicina. S'ha confeccionat una base de dades de preguntes de resposta múltiple que consta actualment de 200 preguntes de bioquímica i biologia molecular classificades i revisades. La utilització tutoritzada dels vídeos i de les preguntes, juntament amb l'avaluació de la comprensió de sessions presencials mitjançant un test ràpid i també l'apropament del coneixement bioquímic a coneixements intuïtius habituals, han permès millorar el rendiment acadèmic de l'alumnat, ja que se n'ha incrementat el nombre que superen les assignatures i també la proporció d'alumnat amb bones qualificacions.El trabajo llevado a cabo se enmarca en un objetivo general de producción de materiales para que se utilicen como herramientas para favorecer el autoaprendizaje en un entorno de docencia semipresencial. Se han hecho dos vídeos de dos técnicas experimentales fundamentales en bioquímica: la cromatografía y la fijación de radio-ligandos. Ambos vídeos corresponden a la filmación de experimentos que implicaban manipulaciones sofisticadas y se llevaron a cabo en los laboratorios docentes de la Unidad de Bioquímica de Medicina. Se ha confeccionado una base de datos de preguntas de respuesta múltiple que consta actualmente de 200 preguntas de bioquímica y biología molecular clasificadas y revisadas. La utilización tutorizada de los vídeos y de laspreguntas, junto con la evaluación de la comprensión de sesiones presenciales mediante un test rápido y también el acercamiento del conocimiento bioquímico a conocimientos intuitivos habituales, han permitido mejorar el rendimiento académico del alumnado, ya que se ha incrementado el número que superan las asignaturas y también la proporción de alumnado con buenas calificaciones.The general objective of this project is the production of materials for use as toolsfor promoting independent learning in a semi-distance learning environment. Two videos were produced of two basic experimental techniques in Biochemistry: chromatography and radioligand binding. Both videos include the filming of experiments that involved sophisticated manipulations which had to be carried out in the teaching laboratories of the Biochemistry Unit in the Faculty of Medicine. A data-base of multiple choice questions was produced. This currently consists of 200 classified and reviewed Biochemistry and Molecular Biology questions. Supervised use of the video and the questions, together with assessment of understanding of presence sessions by means of a Rapid Test and linking biochemical knowledge to normal intuitive knowledge, has led to an improvement in the academic performance of the students, as it has increased the number of students passing the subject as well as the proportion of students with good grades
Association of breast and gut microbiota dysbiosis and the risk of breast cancer: a case-control clinical study
We would like to thank M Luisa Puertas-Martin and Isabel Manzano-Jimenez, nurses at the Unit of Mammary Pathology, General Surgery Service, San Cecilio University Hospital (Granada), without whose enthusiasm the enrolment of participants in Granada would still be stalled. We are indebted to all the women taking part in the study.The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Trial registration
ClinicalTrials.gov NCT03885648, 03/25/2019. Retrospectively registered.Background
Breast cancer ranks first in women, and is the second cause of death in this gender. In addition to genetics, the environment contributes to the development of the disease, although the factors involved are not well known. Among the latter is the influence of microorganisms and, therefore, attention is recently being paid to the mammary microbiota. We hypothesize that the risk of breast cancer could be associated with the composition and functionality of the mammary/gut microbiota, and that exposure to environmental contaminants (endocrine disruptors, EDCs) might contribute to alter these microbiota.
Methods
We describe a case-control clinical study that will be performed in women between 25 and 70 years of age. Cases will be women diagnosed and surgically intervened of breast cancer (stages I and II). Women with antecedents of cancer or advanced tumor stage (metastasis), or who have received antibiotic treatment within a period of 3 months prior to recruitment, or any neoadjuvant therapy, will be excluded. Controls will be women surgically intervened of breast augmentation or reduction. Women with oncological, gynecological or endocrine history, and those who have received antibiotic treatment within a period of 3 months prior to recruitment will also be excluded. Blood, urine, breast tissue and stool samples will be collected. Data regarding anthropometric, sociodemographic, reproductive history, tumor features and dietary habits will be gathered.
Metabolomic studies will be carried out in stool and breast tissue samples. Metagenomic studies will also be performed in stool and breast tissue samples to ascertain the viral, fungal, bacterial and archaea populations of the microbiota. Quantitation of estrogens, estrogen metabolites and EDCs in samples of serum, urine and breast tissue will also be performed.
Discussion: This is the first time that the contribution of bacteria, archaea, viruses and fungi together with their
alteration by environmental contaminants to the risk of breast cancer will be evaluated in the same study. Results
obtained could contribute to elucidate risk factors, improve the prognosis, as well as to propose novel intervention
studies in this disease.This work is funded by grants PI-0538-2017 (Junta de Andalucía, Spain, to LF) and Biomedical Research Networking Center-CIBER de Epidemiología y Salud Pública (CIBERESP) of the Institute of Health Carlos III -supported by European Regional Development Fund/FEDER (FIS-PI16/01812) (to MFF)
Macrophages, Nitric Oxide and microRNAs Are Associated with DNA Damage Response Pathway and Senescence in Inflammatory Bowel Disease
Background:
Cellular senescence can be a functional barrier to carcinogenesis. We hypothesized that inflammation modulates carcinogenesis through senescence and DNA damage response (DDR). We examined the association between senescence and DDR with macrophage levels in inflammatory bowel disease (IBD). In vitro experiments tested the ability of macrophages to induce senescence in primary cells. Inflammation modulating microRNAs were identified in senescence colon tissue for further investigation.
Methodology/Principal Findings:
Quantitative immunohistochemistry identified protein expression by colon cell type. Increased cellular senescence (HP1γ; P = 0.01) or DDR (γH2A.X; P = 0.031, phospho-Chk2, P = 0.014) was associated with high macrophage infiltration in UC. Co-culture with macrophages (ANA-1) induced senescence in >80% of primary cells (fibroblasts MRC5, WI38), illustrating that macrophages induce senescence. Interestingly, macrophage-induced senescence was partly dependent on nitric oxide synthase, and clinically relevant NO• levels alone induced senescence. NO• induced DDR in vitro, as detected by immunofluorescence. In contrast to UC, we noted in Crohn’s disease (CD) that senescence (HP1γ; P<0.001) and DDR (γH2A.X; P<0.05, phospho-Chk2; P<0.001) were higher, and macrophages were not associated with senescence. We hypothesize that nitric oxide may modulate senescence in CD; epithelial cells of CD had higher levels of NOS2 expression than in UC (P = 0.001). Microarrays and quantitative-PCR identified miR-21 expression associated with macrophage infiltration and NOS2 expression.
Conclusions:
Senescence was observed in IBD with senescence-associated β-galactosidase and HP1γ. Macrophages were associated with senescence and DDR in UC, and in vitro experiments with primary human cells showed that macrophages induce senescence, partly through NO•, and that NO• can induce DDR associated with senescence. Future experiments will investigate the role of NO• and miR-21 in senescence. This is the first study to implicate macrophages and nitrosative stress in a direct effect on senescence and DDR, which is relevant to many diseases of inflammation, cancer, and aging.Cancer Research Institute (New York, N.Y.) (Intramural Research Program)National Cancer Institute (U.S.) (Cancer Research Training Award Fellowship)Danish Cancer SocietyDanish National Research FoundationEuropean Commission (projects: Infla-Care, Biomedreg and DDResponse
Allocating Family Responsibilities for Dependent Older People in Mexico and Peru
This paper applies different analytical frameworks to explore processes of family bargaining about providing care for dependent older people in Mexico and Peru. These frameworks include cultural norms, life course effects and material exchange. The paper is based on 19 in-depth qualitative family case studies, which are linked to a wider set of quantitative survey data. Care arrangements and bargaining processes are revealed to be highly gendered, and largely conform to prevailing cultural norms. Rather than neutral and objective, the self-identified role as main carer is found to be subjective and potentially ambiguous. The few men who self-identify as main carers are more likely to play an indirect, organisational role than engage directly in daily care. As such, bargaining mainly relates to which woman performs the main care role, and large family networks mean that there is usually more than one candidate carer. Bargaining can occur inter-generationally and conjugally, but bargaining between siblings is of particular importance. Bargaining is framed by the uncertain trajectory of older people’s care needs, and arrangements are sometimes reconfigured in response to changing care needs or family circumstances. Taking the narratives at face value, the influence of life course effects on bargaining and care arrangements is more obvious than material exchange. There are, however, indications that economic considerations, particularly inheritance, still play an important behind the scenes role
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