64 resultados para Closing the Gap
Resumo:
For landline telephone surveys in particular, undercoverage has been a growing problem. However, research regarding the relative contributions of socio-demographic bias and other composition effects is scarce. We propose to address this issue by analyzing an election survey which used a sample from a register-based sampling frame containing basic socio-demographic information and to which telephone numbers were subsequently matched. With respect to socio-demographic representation of the final sample, we find that difficult to match groups are also difficult to contact, while those who cooperate tend to have different characteristics. We find bias due to undercoverage to be of greater magnitude than noncontact bias, while noncooperation falls between the two. As for substantive variables, both additional efforts to match missing telephone numbers and the construction of better weights are successful in closing the gap between survey estimates of voting behavior and true values from the election results.
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Neurons and astrocytes, the two major cell populations in the adult brain, are characterized by their own mode of intercellular communication--the synapses and the gap junctions (GJ), respectively. In addition, there is increasing evidence for dynamic and metabolic neuroglial interactions resulting in the modulation of synaptic transmission at the so-called "tripartite synapse". Based on this, we have investigated at the ultrastructural level how excitatory synapses (ES) and astroglial GJ are spatially distributed in layer IV of the barrel cortex of the adult mouse. We used specific antibodies for connexin (Cx) 30 and 43 to identify astroglial GJ, these two proteins are known to be present in the majority of astroglial GJ in the cerebral cortex. In electron-microscopic images, we measured the distance between two ES, between two GJ and between a GJ and its nearest ES. We found a ratio of two GJ per three ES in the hollow and septal areas. Taking into account the size of an astrocyte domain, the high density of GJ suggests the occurrence of reflexive type, i.e. GJ between processes of the same astrocyte. Interestingly, the distance between an ES and an astroglial GJ was found to be significantly lower than that between either two synapses or between two GJ. These observations indicate that the two modes of cell-to-cell communication are not randomly distributed in layer IV of the barrel cortex. Consequently, this feature may provide the morphological support for the recently reported functional interactions between neuronal circuits and astroglial networks.
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Erythrokeratodermia variabilis (EKV) is an autosomal dominant keratinization disorder characterized by migratory erythematous lesions and fixed keratotic plaques. All families with EKV show mapping to chromosome 1p34-p35, and mutations in the gene for connexin 31 (Cx31) have been reported in some but not all families. We studied eight affected and three healthy subjects in an Israeli family, of Kurdish origin, with EKV. After having mapped the disorder to chromosome 1p34-p35, we found no mutations in the genes for Cx31, Cx31.1, and Cx37. Further investigation revealed a heterozygous T-->C transition leading to the missense mutation (F137L) in the human gene for Cx30.3 that colocalizes on chromosome 1p34-p35. This nucleotide change cosegregated with the disease and was not found in 200 alleles from normal individuals. This mutation concerns a highly conserved phenylalanine, in the third transmembrane region of the Cx30.3 molecule, known to be implicated in the wall formation of the gap-junction pore. Our results show that mutations in the gene for Cx30.3 can be causally involved in EKV and point to genetic heterogeneity of this disorder. Furthermore, we suggest that our family presents a new type of EKV because of the hitherto unreported association with erythema gyratum repens.
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SUMMARYIntercellular communication is achieved at specialized regions of the plasma membrane by gap junctions. The proteins constituting the gap junctions are called connexins and are encoded by a family of genes highly conserved during evolution. In adult mouse, four connexins (Cxs) are known to be expressed in the vasculature: Cx37, Cx40, Cx43 and Cx45. Several recent studies have provided evidences that vascular connexins expression and blood pressure regulation are closely linked, suggesting a role for connexins in the control of blood pressure. However, the precise function that each vascular connexin plays under physiological and pathophysiological conditions is still not elucidated. In this context, this work was dedicated to evaluate the contribution of each of the four vascular connexins in the control of the vascular function and in the blood pressure regulation.In the present work, we first demonstrated that vascular connexins are differently regulated by hypertension in the mouse aorta. We also observed that endothelial connexins play a regulatory role on eNOS expression levels and function in the aorta, therefore in the control of vascular tone. Then, we demonstrated that Cx40 plays a pivotal role in the kidney by regulating the renal levels of COX-2 and nNOS, two key enzymes of the macula densa known to participate in the control of renin secreting cells. We also found that Cx43 forms the functional gap junction involved in intercellular Ca2+ wave propagation between vascular smooth muscle cells. Finally, we have started to generate transgenic mice expressing specifically Cx40 in the endothelium to investigate the involvement of Cx40 in the vasomotor tone, or in the renin secreting cells to evaluate the role of Cx40 in the control of renin secretion.In conclusion, this work has allowed us to identify new roles for connexins in the vasculature. Our results suggest that vascular connexins could be interesting targets for new therapies caring hypertension and vascular diseases.
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Mutations in the GJB2 gene encoding the gap junction protein connexin 26 are responsible for up to 30% of all cases of autosomal recessive nonsyndromic hearing impairment (HI) with prelingual onset in most populations. The corresponding locus DFNB1, located on chromosome 13q11-q12, is also affected by three distinct deletions. These deletions extended distally to GJB2, which remains intact. We report a novel large deletion in DFNB1 observed in a patient presenting profound prelingual HI. This deletion was observed in trans to a GJB2 mutated allele carrying the p.Val84Met (V84M) mutation and was shown to be associated with hearing loss. The deletion caused a false homozygosity of V84M in the proband. Quantification of alleles by quantitative fluorescent multiplex PCR (QFM-PCR) enabled us to study the breakpoints of the deletion. The deleted segment extended through at least 920kb and removed the three connexin genes GJA3, GJB2 and GJB6. The distal breakpoint inside intron 2 of CRYL1 gene differed from the breakpoints of the known DFNB1 deletions. This case highlights the importance of screening for large deletions in molecular studies of GJB2.
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Channels formed by the gap junction protein Connexin36 (CX36) contribute to the proper control of insulin secretion. We previously demonstrated that chronic exposure to glucose decreases Cx36 levels in insulin-secreting cells in vitro. Here, we investigated whether hyperglycemia also regulates Cx36 in vivo. Using a model of continuous glucose infusion in adult rats, we showed that prolonged (24-48 h) hyperglycemia reduced the Cx36 gene Gjd2 mRNA levels in pancreatic islets. Accordingly, prolonged exposure to high glucose concentrations also reduced the expression and function of Cx36 in the rat insulin-producing INS-1E cell line. The glucose effect was blocked after inhibition of the cAMP/PKA pathway and was associated with an overexpression of the inducible cAMP early repressor ICER-1/ICER-1γ, which binds to a functional cAMP-response element in the promoter of the Cx36 gene Gjd2. The involvement of this repressor was further demonstrated using an antisense strategy of ICER-1 inhibition, which prevented glucose-induced downregulation of Cx36. The data indicate that chronic exposure to glucose alters the in vivo expression of Cx36 by the insulin-producing β-cells through ICER-1/ICER-1γ overexpression. This mechanism may contribute to the reduced glucose sensitivity and altered insulin secretion, which contribute to the pathophysiology of diabetes.
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Background: Mortality figures become available after some years.Materials and methods: Using the World Health Organization mortality and population data, we estimated numbers of deaths in 2011 from all cancers and selected sites for the European Union (EU) and six major countries, by fitting a joinpoint model to 5-year age-specific numbers of deaths. Age-standardized rates were computed using EUROSTAT population estimates.Results: The predicted number of cancer deaths in the EU in 2011 was 1 281 436, with standardized rates of 143/100 000 men and 85/100 000 women. Poland had the highest rates, with smaller falls over recent periods. Declines in mortality for major sites including stomach, colorectum, breast, uterus, prostate and leukemias, plus male lung cancer, will continue until 2011, and a trend reversal or a leveling off is predicted where upward trends were previously observed. Female lung cancer rates are increasing in all major EU countries except the UK, where it is the first cause of cancer death, as now in Poland. The increasing pancreatic cancer trends in women observed up to 2004 have likely leveled off.Conclusions: Despite falls in rates, absolute numbers of cancer deaths are stable in Europe. The gap between Western and former nonmarket economy countries will likely persist.
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QUESTIONS UNDER STUDY/PRINCIPLES: Little is known concerning patients' expectations regarding sexual history taking by doctors: to ascertain expectations and actual experience of talking about sexuality among male patients attending outpatient clinics, and their sexual behaviour. METHODS: Patients consecutively recruited from two outpatient clinics in Lausanne, Switzerland were provided with an anonymous self-administered questionnaire. Survey topics were: patients' expectations concerning sexual history taking, patients' lifetime experience of sexual history taking, and patients' sexual behaviour. RESULTS: The response rate was 53.0% (N = 1452). Among respondents, 90.9% would like their physician to ask them questions regarding their sexual history in order to receive advice on prevention (60.0% yes, 30.9% rather yes). Fifteen percent would be embarrassed or rather embarrassed if asked such questions. Nevertheless, 76.2% of these individuals would like their physician to do so. Despite these wishes, only 40.5% reported ever having a discussion "on their sexual life in general" with a doctor. Only one patient out of four to five was asked about previous sexually transmitted infections (STIs), the number of sexual partners and their sexual orientation. No feature of their sexual life distinguishes those who had discussed sexual issues with a doctor from those who had not, except a history of previous consultation for health problems related to sexuality. Conversely, being embarrassed about conducting this discussion was significantly associated with lack of discussion regarding sexuality. CONCLUSIONS: This study highlights the gap existing in the field of STI prevention in terms of doctors' advice and patients' wishes.
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Strepsirhines comprise 10 living or recently extinct families, ≥50% of extant primate families. Their phylogenetic relationships have been intensively studied, but common topologies have only recently emerged; e.g. all recent reconstructions link the Lepilemuridae and Cheirogaleidae. The position of the indriids, however, remains uncertain, and molecular studies have placed them as the sister to every clade except Daubentonia, the preferred sister group of morphologists. The node subtending Afro-Asian lorisids has been similarly elusive. We probed these phylogenetic inconsistencies using a test data set including 20 strepsirhine taxa and 2 outgroups represented by 3,543 mtDNA base pairs, and 43 selected morphological characters, subjecting the data to maximum parsimony, maximum likelihood and Bayesian inference analyses, and reconstructing topology and node ages jointly from the molecular data using relaxed molecular clock analyses. Our permutations yielded compatible but not identical evolutionary histories, and currently popular techniques seem unable to deal adequately with morphological data. We investigated the influence of morphological characters on tree topologies, and examined the effect of taxon sampling in two experiments: (1) we removed the molecular data only for 5 endangered Malagasy taxa to simulate 'extinction leaving a fossil record'; (2) we removed both the sequence and morphological data for these taxa. Topologies were affected more by the inclusion of morphological data only, indicating that palaeontological studies that involve inserting a partial morphological data set into a combined data matrix of extant species should be interpreted with caution. The gap of approximately 10 million years between the daubentoniid divergence and those of the other Malagasy families deserves more study. The apparently contemporaneous divergence of African and non-daubentoniid Malagasy families 40-30 million years ago may be related to regional plume-induced uplift followed by a global period of cooling and drying. © 2013 S. Karger AG, Basel.
Resumo:
BACKGROUND: The International Breast Cancer Study Group (IBCSG) conducted two complementary randomized trials to assess whether a treatment-free gap during adjuvant chemotherapy influenced outcome. PATIENTS AND METHODS: From 1993 to 1999, IBCSG Trials 13-93 and 14-93 enrolled 2215 premenopausal and postmenopausal women with axillary node-positive, operable breast cancer. All patients received cyclophosphamide (Cytoxan, C) plus either doxorubicin (Adriamycin, A) or epirubicin (E) for four courses followed immediately (No Gap) or after a 16-week delay (Gap) by classical cyclophosphamide, methotrexate, and fluorouracil (CMF) for three courses. The median follow-up was 7.7 years. RESULTS: The Gap and No-Gap groups had similar disease-free survival (DFS) and overall survival (OS). No identified subgroup showed a statistically significant difference, but exploratory subgroup analysis noted a trend towards decreased DFS for Gap compared with No Gap for women with estrogen receptor (ER)-negative tumors not receiving tamoxifen, especially evident during the first 2 years. CONCLUSIONS: A 16-week gap between adjuvant AC/EC and CMF provided no benefit and may have increased early recurrence rates in patients with ER-negative tumors.
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The concept of authority crosses many social sciences, but there is a lack of common taxonomy and definitions on this topic. The aims of this review are: (1) to define the basic characteristics of the authority relationship, reaching a definition suitable for the different domains of social psychology and social sciences; (2) to bridge the gap between individual and societal levels of explanation concerning the authority relationship, by proposing an interpretation within the framework of social representations. The authority relationship can be conceived as a negotiation of meanings and it is closely linked to shared value orientation and the attribution of meanings negotiated within a society. We assume that the authority relationship is socially constructed and represents both a shared representation of society and a normative principle of social life. A multidisciplinary approach is adopted, crossing definitions and studies provided in sociology, political science, law and social psychology.
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The Miocene Paine Granite in the Torres del Paine Intrusive Complex, southern Chile, is an extraordinary example of an upper crustal mafic and granitic intrusion. The granite intruded as a series of three sheets, each one underplating the previous sheet along the top of the basal Paine Mafic Complex. High-precision U/Pb geochronology on single zircons using isotope dilution-thermal ionization mass spectrometry yields distinct ages of 12.59 +/- 0.02 Ma and 12.50 +/- 0.02 Ma, respectively, for the first and last sheet of the laccolith. This age relationship is consistent with field observations. The zircon ages define a time frame of 90 +/- 40 k.y. for the emplacement of a >2000-m-thick granite laccollith. These precise U-Pb zircon ages permit identification of the pulses in a 20 k.y. range. The data obtained for the Paine Granite fill the gap between 100 k.y. and 100-1000 yr pulses described in the literature for crustal magma chambers.
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En Suisse, le nombre de filles et de femmes migrantes excisées au cours de leur enfance dans leur pays d'origine ou menacées de mutilations génitales rituelles est estimé à 6-7000. Les professionnels de la santé en tant qu'interlocuteurs privilégiés doivent donc être en mesure de répondre aux questions y relatives, non seulement durant l'adolescence, mais aussi dans toutes les phases de la vie. L'absence d'information ou de transmission par des aînées aussi bien avant l'excision qu'au moment de la maturité sexuelle en fait souvent un événement biographique traumatisant. Arrivées en Suisse, le décalage entre les attentes socioculturelles et familiales et le vécu individuel, influencé par le pays d'accueil, peut s'avérer particulièrement difficile à vivre pour les jeunes filles concernées. In Switzerland, the estimated number of survivors after traditional female genital mutilation in the country of origin or girls and adult women at risk is 6-7000. Health professionals must be able to respond adequately to their questions not only during adolescence but through out the different periods of life. The lack of information or transmission by the seniors as well before the excision as at the time of sexual maturity contributes in a large measure to the frequent biographic trauma. It can be very difficult for the girls to deal with the gap between socio cultural and family expectations and their individual life experience in Switzerland.
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The Plinius Maior Society is a European multinational, multidisciplinary group of clinicians and researchers in the alcoholism field, which strives for a comprehensive care concept in the management of alcoholism and alcohol-related problems. The Society, using evidence-based medicine, has developed a set of protocols, in the forms of guidelines, flow-charts, leaflets and booklets, for use as tools in research on and treatment of alcohol dependence, with a view to standardize clinical research procedures and to bridge the gap between the alcoholism researcher, practitioner and patient. These protocols or tools have been subjected to a review process during their preparation, and further comments on their validity will be integrated in their updates. Seven protocols have so far been developed, two of which, 'Guidelines on Evaluation of Treatment of Alcohol Dependence' and 'Detection and Management of Patients with Psychiatric and Alcohol Use Disorders', are aimed at the clinical researcher and specialists, whereas three others [in the form of decision trees (flow-charts)] are aimed at the general practitioner and other primary health care providers. These are entitled 'Alcohol Risk Assessment and Intervention in Primary Care', 'Withdrawal from Alcohol at Home' and 'Brief Intervention in Patients with Alcohol-Related Problems'. The remaining two tools are booklets aimed at the patient, one to support initiatives for detection of drinking problems and primary intervention, namely 'Do you have this Problem? Discuss it with your Doctor!', and the other to assist the patient in relapse prevention after the early stages of treatment, namely 'On the Way to Recovery'. The protocols for the general practitioners and patients have so far been produced in seven European languages, and, as with the Guidelines, feedback from target users will be collected and incorporated in future updates. The Society continually seeks to consider areas of clinical importance for its work and, as it enters the new millennium, it hopes to address and make a significant contribution to the most pressing problem in the management of alcohol dependence, namely relapse.
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The emergence of multicellular organisms has necessitated the development of mechanisms for interactions between adjacent and distant cells. A consistent feature of this network is the expression of gap junction channels between the secretory cells of all glands so far investigated in vertebrates. Here, we reviewed the distribution of the gap junctions proteins, named connexins, in a few mammalian glands, and discussed the recent evidence pointing to the participation of these proteins in the functioning of endocrine and exocrine cells. Specifically, available data indicate the importance of gap junctions for the proper control of glucose-induced insulin secretion. Understanding the functions of beta-cell connexins are crucial for the engineering of surrogate cells, which is necessary for implementation of a replacement cell therapy in diabetic patients.