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INTRODUCCIÓN: Las muertes por suicidio en jóvenes han ido en aumento en las últimas décadas y se considera un problema de salud pública prioritario a nivel mundial, siendo un evento parcialmente prevenible. La prevalencia de ideas suicidas es alta entre estudiantes universitarios, especialmente en carreras de la salud. El objetivo de este estudio fue medir la prevalencia de alto riesgo suicida en este grupo específico e identificar factores asociados, con la finalidad de aportar evidencia empírica para la construcción de estrategias efectivas de prevención del suicidio. MÉTODOS: Se realizó un estudio transversal basado en una encuesta en línea a estudiantes de carreras de la salud, casi al final del primer año de la pandemia de COVID-19, para conocer la frecuencia del riesgo suicida y sus factores asociados. La muestra fue de 477 estudiantes (70,8% mujeres, edad promedio 21,7 ± 2,5 años), de ocho carreras de la salud. Los datos se recogieron en enero de 2021. RESULTADOS: Un 22,6% de los jóvenes reportó un alto riesgo suicida en la escala de Okasha y 3,4% hizo un intento suicida en el año previo. Los factores asociados al alto riesgo suicida fueron: tener una orientación no-heterosexual, una trayectoria académica irregular, experiencias de violencia física y/o psicológica, mayores niveles de sintomatología depresiva y ansiosa, así como menores niveles de apoyo social de amigos y de la familia. CONCLUSIONES: Las cifras de riesgo e intentos suicidas son elevadas en este grupo de estudiantes y existe un perfil de factores que podrían orientar acciones más efectivas, tales como apoyo a grupos de mayor riesgo y hacer tamizaje para identificar y dar ayuda a jóvenes con alto riesgo suicida y con problemas de salud mental.
INTRODUCTION: Suicide deaths in young people have been increasing in recent decades and are considered a major public health problem worldwide, being a partially preventable event. The prevalence of suicidal ideation is high among university students, especially in health careers. The objective of this study was to measure the prevalence of high suicidal risk in this specific group and to identify associated factors, aiming to provide empirical evidence for the construction of effective suicide prevention strategies. METHODS: A cross-sectional study was conducted based on an online survey directed to healthcare students near the end of the first year of the COVID-19 pandemic to learn about the frequency of suicidal risk and its associated factors. The sample consisted of 477 students (70.8% female, mean age 21.7 ± 2.5 years) from eight healthcare majors. The data were collected in January 2021. RESULTS: 22.6% of the young people reported a high suicide risk on the Okasha scale, and 3.4% made a suicide attempt in the previous year. Factors associated with high suicidal risk were having a non-heterosexual orientation, an irregular academic trajectory, experiences of physical and/or psychological violence, higher levels of depressive and anxious symptomatology, as well as lower levels of social support from friends and family. CONCLUSIONS: Suicide risk and attempt levels are high in this group of students, and there is a group of factors that could guide more effective actions, such as support for higher-risk groups and screening to identify and provide support to young people at high suicidal risk and with mental health conditions.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Adulto Jovem , Tentativa de Suicídio/estatística & dados numéricos , Ideação Suicida , COVID-19/prevenção & controle , COVID-19/epidemiologia , Apoio Social , Estudantes de Ciências da Saúde/psicologia , Suicídio/psicologia , Suicídio/estatística & dados numéricos , Prevalência , Estudos Transversais , Inquéritos e Questionários , Fatores de Risco , Depressão/epidemiologiaRESUMO
Introduction: Suicide deaths in young people have been increasing in recent decades and are considered a major public health problem worldwide, being a partially preventable event. The prevalence of suicidal ideation is high among university students, especially in health careers. The objective of this study was to measure the prevalence of high suicidal risk in this specific group and to identify associated factors, aiming to provide empirical evidence for the construction of effective suicide prevention strategies. Methods: A cross-sectional study was conducted based on an online survey directed to healthcare students near the end of the first year of the COVID-19 pandemic to learn about the frequency of suicidal risk and its associated factors. The sample consisted of 477 students (70.8% female, mean age 21.7 ± 2.5 years) from eight healthcare majors. The data were collected in January 2021. Results: 22.6% of the young people reported a high suicide risk on the Okasha scale, and 3.4% made a suicide attempt in the previous year. Factors associated with high suicidal risk were having a non-heterosexual orientation, an irregular academic trajectory, experiences of physical and/or psychological violence, higher levels of depressive and anxious symptomatology, as well as lower levels of social support from friends and family. Conclusions: Suicide risk and attempt levels are high in this group of students, and there is a group of factors that could guide more effective actions, such as support for higher-risk groups and screening to identify and provide support to young people at high suicidal risk and with mental health conditions.
Introducción: Las muertes por suicidio en jóvenes han ido en aumento en las últimas décadas y se considera un problema de salud pública prioritario a nivel mundial, siendo un evento parcialmente prevenible. La prevalencia de ideas suicidas es alta entre estudiantes universitarios, especialmente en carreras de la salud. El objetivo de este estudio fue medir la prevalencia de alto riesgo suicida en este grupo específico e identificar factores asociados, con la finalidad de aportar evidencia empírica para la construcción de estrategias efectivas de prevención del suicidio. Métodos: Se realizó un estudio transversal basado en una encuesta en línea a estudiantes de carreras de la salud, casi al final del primer año de la pandemia de COVID-19, para conocer la frecuencia del riesgo suicida y sus factores asociados. La muestra fue de 477 estudiantes (70,8% mujeres, edad promedio 21,7 ± 2,5 años), de ocho carreras de la salud. Los datos se recogieron en enero de 2021. Resultados: Un 22,6% de los jóvenes reportó un alto riesgo suicida en la escala de Okasha y 3,4% hizo un intento suicida en el año previo. Los factores asociados al alto riesgo suicida fueron: tener una orientación no-heterosexual, una trayectoria académica irregular, experiencias de violencia física y/o psicológica, mayores niveles de sintomatología depresiva y ansiosa, así como menores niveles de apoyo social de amigos y de la familia. Conclusiones: Las cifras de riesgo e intentos suicidas son elevadas en este grupo de estudiantes y existe un perfil de factores que podrían orientar acciones más efectivas, tales como apoyo a grupos de mayor riesgo y hacer tamizaje para identificar y dar ayuda a jóvenes con alto riesgo suicida y con problemas de salud mental.
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COVID-19 , Ideação Suicida , Tentativa de Suicídio , Humanos , Estudos Transversais , Feminino , Masculino , Adulto Jovem , COVID-19/epidemiologia , COVID-19/prevenção & controle , Tentativa de Suicídio/estatística & dados numéricos , Fatores de Risco , Inquéritos e Questionários , Estudantes de Ciências da Saúde/psicologia , Prevalência , Adolescente , Adulto , Suicídio/estatística & dados numéricos , Suicídio/psicologia , Apoio Social , Depressão/epidemiologiaRESUMO
Many group-living animals coordinate social behaviours using contact calls, which can be produced for all group members or targeted at specific individuals. In the disc-winged bat, Thyroptera tricolor, group members use 'inquiry' and 'response' calls to coordinate daily movements into new roosts (furled leaves). Rates of both calls show consistent among-individual variation, but causes of within-individual variation remain unknown. Here, we tested whether disc-winged bats produce more contact calls towards group members with higher kinship or association. In 446 experimental trials, we recorded 139 random within-group pairs of one flying bat (producing inquiry calls for roost searching) and one roosting bat (producing response calls for roost advertising). Using generalized linear mixed-effect models (GLMM), we assessed how response and inquiry calling rates varied by sender, receiver, genetic kinship and co-roosting association rate. Calling rates varied consistently across senders but not by receiver. Response calling was influenced by inquiry calling rates, but neither calling rate was higher when the interacting pair had higher kinship or association. Rather than dyadic calling rates indicating within-group relationships, our findings are consistent with the hypothesis that bats produce contact calls to maintain contact with any or all individuals within a group while collectively searching for a new roost site. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
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Quirópteros , Comportamento Social , Vocalização Animal , Quirópteros/fisiologia , Animais , Masculino , FemininoRESUMO
Agave durangensis commonly known as agave cenizo, is an endemic Agave species in Mexico used for mescal production, yet its taxonomic delimitation is still controversial. This study aimed to enhance taxonomic clarity by characterizing its chloroplast genome. Chloroplast DNA was isolated from 2-year-old A. durangensis leaves. The complete chloroplast genome size was 156,441 bp, comprising a large single-copy region (LSC), a pair of inverted repeat regions (IR), and a small single-copy region (SSC). Annotation revealed 87 protein-coding genes, 38 tRNAs, and 8 rRNAs, with notable gene inversions. Phylogenetic analysis suggests, A. durangensis forms a separate lineage within the Agave genus.
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A green fluorescent protein (GFP)-based whole-cell biosensor (WCB-GFP) for monitoring arsenic (As) was developed in Bacillus subtilis. To this end, we designed a reporter gene fusion carrying the gfpmut3a gene under the control of the promoter/operator region of the arsenic operon (Pars::gfpmut3a) in the extrachromosomal plasmid pAD123. This construct was transformed into B. subtilis 168, and the resultant strain was used as a whole-cell biosensor (BsWCB-GFP) for the detection of As. The BsWCB-GFP was specifically activated by inorganic As(III) and As(V), but not by dimethylarsinic acid [DMA(V)], and exhibited high tolerance to the noxious effects of arsenic. Accordingly, after 12 h exposure, B. subtilis cells carrying the Pars::gfpmut3a fusion exhibited 50 and 90% lethal doses (LD50 and LD90) to As(III) of 0.89 mM and As 1.71 mM, respectively. Notably, dormant spores from the BsWCB-GFP were able to report the presence of As(III) in a concentration range from 0.1 to 1,000 µM 4 h after the onset of germination. In summary, the specificity and high sensitivity for As, as well as its ability to proliferate under concentrations of the metal that are considered toxic in water and soil, makes the B. subtilis biosensor developed here a potentially important tool for monitoring environmental samples contaminated with this pollutant. IMPORTANCE Arsenic (As) contamination of groundwater is associated with serious worldwide health risks. Detection of this pollutant at concentrations that are established as permissible for water consumption by WHO is a matter of significant interest. Here, we report the generation of a whole-cell biosensor for As detection in the Gram-positive spore former B. subtilis. This biosensor reports the presence of inorganic As, activating the expression of the green fluorescent protein (GFP) under the control of the promoter/operator of the ars operon. The biosensor can proliferate under concentrations of As(III) that are considered toxic in water and soil and detect this ion at concentrations as low as 0.1 µM. Of note, spores of the Pars-GFP biosensor exhibited the ability to detect As(III) following germination and outgrowth. Therefore, this novel tool has the potential to be directly applied to monitor As contamination in environmental samples.
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Arsênio , Técnicas Biossensoriais , Poluentes Ambientais , Bacillus subtilis/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Arsênio/metabolismo , Esporos Bacterianos/genética , Esporos Bacterianos/química , Água/metabolismo , Poluentes Ambientais/metabolismoRESUMO
OBJECTIVE: The main aim of the current study was to investigate whether SKA2 gene expression in the postmortem brain of rs7208505 genotype are altered in suicide victims from a Mexican population. METHODS: In this study, we report a genetic analysis of expression levels of the SKA2 gene in the prefrontal cortex of the postmortem brain of suicidal subjects (n = 22) compared to subjects who died of causes other than suicide (n = 22) in a Mexican population using RT-qPCR assays. Additionally, we genotyped the rs7208505 polymorphism in suicide victims (n = 98) and controls (n = 88) and we evaluate the association of genotypes for the SNP rs7208505 with expression level of SKA2. RESULTS: The results showed that the expression of the SKA2 gene was significantly higher in suicide victims compared to control subjects (p = 0.044). Interestingly, we observed a greater proportion of allele A of the rs7208505 in suicide victims than controls. Even though there was no association between the SNP with suicide in the study population we found a significative association of the expression level from SKA2 with the allele A of the rs7208505 and suicide. CONCLUSION: The evidence suggests that the expression of SKA2 in the prefrontal cortex may be a critical factor in the etiology of suicidal behavior.
HighlightsSuicide victims have a higher level of SKA2 gene expression in the brain's prefrontal cortex than control subjects.The SKA2 rs7208505 is not associated with suicide in the Mexican population studied.Allele frequencies for G are higher than allele frequencies for A in our study population.The allele A of the rs7208505 affects the expression values of the SKA2 gene.
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Roosts are vital for the survival of many species, and how individuals choose one site over another is affected by various factors. In bats, for example, species may use stiff roosts such as caves or compliant ones such as leaves; each type requires not only specific morphological adaptations but also different landing manoeuvres. Selecting a suitable roost within those broad categories may increase landing performance, reducing accidents and decreasing exposure time to predators. We addressed whether bats select specific roost sites based on the availability of a suitable landing surface, which could increase landing performance. Our study focused on Spix's disc-winged bats (Thyroptera tricolor), a species known to roost within developing tubular leaves. As previous studies show that this species relies on the leaves' apex for safe landing and rapid post-landing settlement, we predicted that bats would prefer to roost in tubular structures with a longer apex and that landing would be consistently more effective on those leaves. Field observations showed that T. tricolor predominantly used two species for roosting, Heliconia imbricata and Calathea lutea, but they preferred roosting in the former. The main difference between these two plant species was the length of the leaf's apex (longer in H. imbricata). Experiments in a flight cage also showed that bats used more consistent approach and landing tactics when accessing leaves with a longer apex. Our results suggest that landing mechanics may strongly influence resource selection, especially when complex manoeuvres are needed to acquire those resources.
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Quirópteros , Humanos , Animais , Cavernas , Folhas de PlantaRESUMO
OBJECTIVE: The main aim of the current study was to investigate whether the expression levels of the HTR2A and MAOA genes are altered in the postmortem brain of suicide victims from Mexican population. METHODS: On the basis of a case- control study, we examined the expression levels of HTR2A and MAOA genes in the postmortem prefrontal cortex (Brodmann area 8/9) and hypothalamus (ventromedial nucleus) tissues from 20 suicide victims and 20 control subjects from a Mexican population. Gene-expression profile quantification was carried out by qPCR and determined by the 2-ΔΔCt method. RESULTS: In suicide victims, the expression levels of the HTR2A gene were significantly higher in the prefrontal cortex. In contrast, the expression of the MAOA gene in the hypothalamus of the suicide victims was significantly higher than in the control subjects. These results were consistent regardless of age, sex, postmortem interval, or pH of brain tissue. CONCLUSION: The evidence suggests that the pattern of differential expression of HTR2A and MAOA genes in the brain may be involved in suicide, providing a possible molecular basis for the brain abnormalities in suicide victims.
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Suicídio , Encéfalo/metabolismo , Estudos de Casos e Controles , Humanos , Hipotálamo , Córtex Pré-Frontal/metabolismoRESUMO
In many health systems, it is difficult to carry out traditional rehabilitation programs as the systems are stressed. We evaluate the effectiveness of a telerehabilitation program conducted in primary care in post-COVID-19 patients. An observational, prospective study was conducted in seven primary care centers in Chile. We included adult patients (>18 years) with a previous SARS-CoV-2 infection. The telerehabilitation program consisted of 24 sessions of supervised home-based exercise training. The efficacy was measured by the 1-min sit-to-stand test (1-min STST), the 36-Item Short Form Health Survey (SF-36), fatigue, and dyspnea symptoms before and after intervention. We included 115 patients (55.4% female) with a mean age of 55.6 ± 12.7 years. Fifty-seven patients (50%) had antecedents of hospitalization, and 35 (30.4%) were admitted to the ICU. The 1-min STST was improved after the intervention from 20.5 ± 10.2 (53.1 ± 25.0%predicted) to 29.4 ± 11.9 (78.2 ± 28.0%predicted) repetitions (p < 0.001). The SF-36 global score improved significantly from 39.6 ± 17.6 to 58.9 ± 20.5. Fatigue and dyspnea improved significantly after the intervention. Although limited by the absence of a control group, this report showed that a telerehabilitation program applied in primary health care is feasible and was effective in improving physical capacity, quality of life and symptoms in adult survivors of COVID-19.
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Traditional techniques for cancer diagnosis, such as nuclear magnetic resonance, ultrasound and tissue analysis, require sophisticated devices and highly trained personnel, which are characterized by elevated operation costs. The use of biomarkers has emerged as an alternative for cancer diagnosis, prognosis and prediction because their measurement in tissues or fluids, such as blood, urine or saliva, is characterized by shorter processing times. However, the biomarkers used currently, and the techniques used for their measurement, including ELISA, western-blot, polymerase chain reaction (PCR) or immunohistochemistry, possess low sensitivity and specificity. Therefore, the search for new proteomic, genomic or immunological biomarkers and the development of new noninvasive, easier and cheaper techniques that meet the sensitivity and specificity criteria for the diagnosis, prognosis and prediction of this disease has become a relevant topic. The purpose of this review is to provide an overview about the search for new cancer biomarkers, including the strategies that must be followed to identify them, as well as presenting the latest advances in the development of biosensors that possess a high potential for cancer diagnosis, prognosis and prediction, mainly focusing on their relevance in lung, prostate and breast cancers.
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Biomarcadores Tumorais/análise , Técnicas Biossensoriais/métodos , Neoplasias da Mama/diagnóstico , Detecção Precoce de Câncer/métodos , Neoplasias Pulmonares/diagnóstico , Neoplasias da Próstata/diagnóstico , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Epigênese Genética/genética , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Prognóstico , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Proteômica/métodosRESUMO
BACKGROUND: Cholesterol has been associated as a risk factor for cardiovascular disease. Recently, however, there is growing evidence about crucial requirement of neuron membrane cholesterol in the organization and function of the 5-HT1A serotonin receptor. For this, low cholesterol level has been reported to be associated with depression and suicidality. However there have been inconsistent reports about this finding and the exact relationship between these factors remains controversial. Therefore, we investigated the link between serum cholesterol and its fractions with depression disorder and suicide attempt in 467 adult subjects in Mexican mestizo population. METHODS: Plasma levels of total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-c) and low density lipoprotein cholesterol (LDL-c) were determined in 261 MDD patients meeting the DSM-5 criteria for major depressive disorder (MDD), 59 of whom had undergone an episode of suicide attempt, and 206 healthy controls. RESULTS: A significant decrease in total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglyceride serum levels was observed in the groups of MDD patients and suicide attempt compared to those without suicidal behavior (p < 0.05). After adjusting for covariates, lower cholesterol levels were significantly associated with MDD (OR 4.229 CI 95% 2.555 - 7.000, p<.001) and suicide attempt (OR 5.540 CI 95% 2.825 - 10.866, p<.001) CONCLUSIONS: These results support the hypothesis that lower levels of cholesterol are associated with mood disorders like MDD and suicidal behavior. More mechanistic studies are needed to further explain this association.
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Colesterol/sangue , Depressão/sangue , Transtorno Depressivo Maior/sangue , Hipolipoproteinemias/psicologia , Adulto , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Depressão/epidemiologia , Depressão/etiologia , Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/etiologia , Feminino , Humanos , Hipolipoproteinemias/epidemiologia , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Fatores de Risco , Ideação Suicida , Tentativa de Suicídio/psicologia , Triglicerídeos/sangueRESUMO
OBJECTIVE: The aim of this study was to determine malondialdehyde (MDA) concentration as an oxidative stress marker and total antioxidant capacity (TAC) in pregnancy before and after perinatal event. METHODS: This study was performed on 200 healthy full-term pregnant women admitted to pregnancy resolution in Maternal-Child Hospital of Durango, Mexico. Oxidative stress and TAC were assessed through detection of lipid peroxidation by quantitation of thiobarbituric acid-reactive substances (TBARS) and TAC through ferric reducing ability of the plasma (FRAP). RESULTS: Our results showed increased levels of MDA after vaginal delivery (VD). TAC was also increased after obstetric event, but it did not differ between VD and caesarean section. CONCLUSIONS: We demonstrated that MDA concentrations are increased two hours after obstetric event, and this increase correlates with VD. The TAC was increased as a compensatory mechanism during obstetric event. Another important finding is that women receiving analgesia administration in VD, as well as dexamethasone administration in caesarean section, experienced a protector effect that decreased MDA levels.
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Parto Obstétrico , Malondialdeído/sangue , Estresse Oxidativo/fisiologia , Adulto , Analgesia Obstétrica , Antioxidantes/análise , Biomarcadores/sangue , Cesárea , Dexametasona/administração & dosagem , Feminino , Humanos , Peroxidação de Lipídeos , Masculino , México , Gravidez , Resultado da Gravidez , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Adulto JovemRESUMO
BACKGROUND: Exposure to arsenic in drinking water has been associated with various complications of pregnancy including fetal loss, low birth weight, anemia, gestational diabetes and spontaneous abortion. However, to date, there are no studies evaluating its possible association with preeclampsia. METHODS: This case-control study involved 104 preeclamptic and 202 healthy pregnant women. The concentrations of arsenic in drinking water and urine were measured using a Microwave Plasma-Atomic Emission Spectrometer. RESULTS: We found relatively low levels of arsenic in household tap water (range of 2.48-76.02 µg/L) and in the urine of the participants (7.1 µg/L vs 6.78 µg/L in cases and controls, respectively). CONCLUSIONS: The analysis between groups showed for the first time that at these lower levels of exposure there is no association with preeclampsia.
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Arsênio/análise , Água Potável/química , Pré-Eclâmpsia/epidemiologia , Adolescente , Adulto , Arsênio/urina , Estudos de Casos e Controles , Etnicidade , Feminino , Humanos , México/epidemiologia , Gravidez , Estudos Prospectivos , Adulto JovemRESUMO
In the context of global change the possible loss of biodiversity has been identified as a major concern. Biodiversity could be seriously threatened as a direct consequence of changes in availability of food, changing thermal conditions, and loss and fragmentation of habitat. Considering the magnitude of global change, an understanding of the mechanisms involved in coping with a changing environment is urgent. We explore the hypothesis that species and individuals experiencing highly variable environments are more likely to develop a wider range of responses to handle the different and unpredictable conditions imposed by global change. In the case of vertebrates, the responses to the challenges imposed by unpredictable perturbations ultimately are linked to cognitive abilities allowing the solving of problems, and the maximization of energy intake. Our models were hummingbirds, which offer a particularly compelling group in which to examine the functional and mechanistic links between behavioral and energetic strategies in individuals experiencing different degrees of social and environmental heterogeneity.
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Aves/fisiologia , Cognição , Ecossistema , Animais , California , Chile , Costa Rica , Meio Ambiente , Feminino , MasculinoRESUMO
Variations in genes involved in DNA repair systems have been proposed as risk factors for the development of preeclampsia (PE). We conducted a case-control study to investigate the association of Human apurinic/apyrimidinic (AP) endonuclease (APEX1) Asp148Glu (rs1130409), Xeroderma Pigmentosum group D (XPD) Lys751Gln (rs13181), X-ray repair cross-complementing group 1 (XRCC) Arg399Gln (rs25487) and X-ray repair cross-complementing group 3 (XRCC3) Thr241Met (rs861539) polymorphisms with PE in a Mexican population. Samples of 202 cases and 350 controls were genotyped using RTPCR. Association analyses based on a χ2 test and binary logistic regression were performed to determine the odds ratio (OR) and a 95% confidence interval (95% CI) for each polymorphism. The allelic frequencies of APEX1 Asp148Glu polymorphism showed statistical significant differences between preeclamptic and normal women (p = 0.036). Although neither of the polymorphisms proved to be a risk factor for the disease, the APEX1 Asp148Glu polymorphism showed a tendency of association (OR: 1.74, 95% CI = 0.96-3.14) and a significant trend (p for trend = 0.048). A subgroup analyses revealed differences in the allelic frequencies of APEX1 Asp148Glu polymorphism between women with mild preeclampsia and severe preeclampsia (p = 0.035). In conclusion, our results reveal no association between XPD Lys751Gln, XRCC Arg399Gln and XRCC3 Thr241Met polymorphisms and the risk of PE in a Mexican mestizo population; however, the results in the APEX1 Asp148Glu polymorphism suggest the need for future studies using a larger sample size.
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DNA Liase (Sítios Apurínicos ou Apirimidínicos)/genética , Proteínas de Ligação a DNA/genética , Polimorfismo de Nucleotídeo Único , Pré-Eclâmpsia/genética , Proteína Grupo D do Xeroderma Pigmentoso/genética , Adolescente , Adulto , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Reparo do DNA/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença/genética , Genótipo , Humanos , Modelos Logísticos , México , Razão de Chances , Pré-Eclâmpsia/patologia , Gravidez , Fatores de Risco , Índice de Gravidade de Doença , Proteína 1 Complementadora Cruzada de Reparo de Raio-X , Adulto JovemRESUMO
OBJECTIVE: To investigate the relationship between COMT G675A and MTHFR C677T polymorphisms and hypertension disorders of pregnancy (HDP) in a Mexican mestizo population. DESIGN AND METHODS: This case-control study involved 194 HDP and 194 normoevolutive pregnant women. The polymorphisms were genotyped by real time PCR. RESULTS: Our results showed that the COMT AA genotype increases the risk to HDP (OR: 2.67; 95% CI 1.33-5.35), preeclampsia (OR: 2.69; 95% CI 1.00-7.22) and gestational hypertension (OR: 3.87; 95% CI 1.25-12.0). Furthermore, the double mutant genotype (COMTAA/MTHFRTT) potency the risk to HDP more than two times (OR: 5.21; 95% CI 1.12-24.3, p=0.019). CONCLUSION: Our work provides evidence that COMT 675AA genotype is a risk factor for HDP and that this risk is increased by the presence of MTHFR 677TT genotype in a Mexican mestizo population.
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Vocal learning in birds is typically restricted to a sensitive period early in life, with the few exceptions reported in songbirds and parrots. Here, we present evidence of open-ended vocal learning in a hummingbird, the third avian group with vocal learning. We studied vocalizations at four leks of the long-billed hermit Phaethornis longirostris during a four-year period. Individuals produce a single song repertoire, although several song-types can coexist at a single lek. We found that nine of 49 birds recorded on multiple days (18%) changed their song-type between consecutive recordings. Three of these birds replaced song-types twice. Moreover, the earliest estimated age when song replacement occurred ranged from 186 to 547 days (mean = 307 days) and all nine birds who replaced song-types produced a crystallized song before replacement. The findings indicate that song-type replacement is distinct from an initial early learning sensitive period. As half of lekking males do not survive past the first year of life in this species, song learning may well extend throughout the lifespan. This behaviour would be convergent to vocal learning programmes found in parrots and songbirds.
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Aves/fisiologia , Aprendizagem/fisiologia , Vocalização Animal/fisiologia , Fatores Etários , Animais , Costa Rica , Masculino , Espectrografia do SomRESUMO
BACKGROUND: Oxidative stress has been associated with several complex diseases. Effects generated as a result of oxidative stress may be modulated by various genes. Variation in these genes, particularly when located within coding or regulating regions, may be the primary cause of this modulation. The aim of this work was to determine the allelic and genotypic frequencies of CAT C-262T, SOD3 Ala58Thr, APEX1 Asp148Glu, XPD Lys751Gln and XRCC3 Thr241Met genetic markers in a northern Mexican population. SUBJECTS AND METHODS: This study analysed 250 unrelated individuals by RT-PCR. RESULTS: A high allele mutant frequency was found in SOD3 Ala58Thr and APEX1 Asp148Glu genetic markers (0.395 and 0.38, respectively). A correspondence analysis showed that northern Mexicans are close to European populations. A linkage disequilibrium test between XPD Lys751Gln and CAT C-262T and XPD Lys751Gln and SOD3 Ala58Thr genetic markers was significant (p = 0.000). CONCLUSION: The genetic markers described in this work will be a valuable resource for future functional studies in the northern Mexican population to explore comprehensively their role in the aetiology of human diseases. Furthermore, it will be necessary to replicate these studies in other regions of Mexico due to differences between Mexican sub-populations.
Assuntos
Reparo do DNA , Frequência do Gene , Estresse Oxidativo , Polimorfismo de Nucleotídeo Único , Feminino , Marcadores Genéticos , Humanos , Masculino , México , Reação em Cadeia da Polimerase em Tempo RealRESUMO
The nucleotide excision repair (NER) and spore photoproduct lyase DNA repair pathways are major determinants of Bacillus subtilis spore resistance to UV radiation. We report here that a putative ultraviolet (UV) damage endonuclease encoded by ywjD confers protection to developing and dormant spores of B. subtilis against UV DNA damage. In agreement with its predicted function, a His(6)-YwjD recombinant protein catalyzed the specific incision of UV-irradiated DNA in vitro. The maximum expression of a reporter gene fusion to the ywjD opening reading frame occurred late in sporulation, and this maximal expression was dependent on the forespore-specific RNA polymerase sigma factor, σ(G). Although the absence of YwjD and/or UvrA, an essential protein of the NER pathway, sensitized developing spores to UV-C, this effect was lower when these cells were treated with UV-B. In contrast, UV-B but not UV-C radiation dramatically decreased the survival of dormant spores deficient in both YwjD and UvrA. The distinct range of lesions generated by UV-C and UV-B and the different DNA photochemistry in developing and dormant spores may cause these differences. We postulate that in addition to the UvrABC repair system, developing and dormant spores of B. subtilis also rely on an alternative excision repair pathway involving YwjD to deal with the deleterious effects of various UV photoproducts.
Assuntos
Bacillus subtilis/fisiologia , Bacillus subtilis/efeitos da radiação , Dano ao DNA/efeitos da radiação , Reparo do DNA/fisiologia , Esporos Bacterianos/efeitos da radiação , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , DNA Bacteriano , Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Raios UltravioletaRESUMO
The effects of overexpression of the apurinic/apyrimidinic DNA endonuclease Nfo on wet and dry heat and UV-C (254 nm) resistance of Bacillus subtilis spores with or without alpha/beta-type small, acid-soluble spore proteins (SASP) were determined. Results revealed that overexpression of Nfo > or =50-fold in spores increased the wet heat resistance of exoA nfo B. subtilis spores (termed alpha(-)beta(-)) that lack most alpha/beta-type SASP, but had no effect on these spores' UV-C resistance. Nfo overexpression also increased these spores' dry heat resistance, and to levels slightly greater than that of wild-type spores. These results are consistent: (1) with wet and dry heat (but not UV-C) generating abasic sites in alpha(-)beta(-) spore DNA; (2) with dry heat generating some of these lesions in spores that retain alpha/beta-type SASP; and (3) indicate that Nfo can repair these abasic lesions following spore germination.