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642 result(s) for "Contreras, Carmen A."
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Frequency of respiratory virus-associated infection among children and adolescents from a tertiary-care hospital in Mexico City
Acute respiratory infections (ARIs) are a major cause of morbidity and mortality among children. The causative pathogens show geographic and seasonal variations. We retrospectively evaluated the frequency and seasonality of respiratory pathogens in children and adolescents (age: 0–19 years) with ARIs treated between January 1, 2021, and March 31, 2022, at a single center in Mexico. Out of 2400 patients, 1,603 were diagnosed with SARS-CoV-2 infection and 797 were diagnosed with other common respiratory pathogens (CRPs). Of the 797 patients, 632 were infected with one CRP and 165 with > 2 CRPs. Deaths occurred only in SARS-CoV-2-infected patients. Rhinovirus/Enterovirus, respiratory syncytial virus B, and parainfluenza virus 3 were the most prevalent in cases with single and multiple infections. CRP showed a high frequency between autumn and winter of 2021, with higher incidence of hospitalization compared to COVID-19. The main comorbidities were immunosuppression, cardiovascular disease (CD), and asthma. The frequency of CRPs showed a downward trend throughout the first half of 2021. CRPs increased in single- and co-infection cases between the fourth and fifth waves of COVID-19, probably due to decreased nonpharmaceutical interventions and changes in diagnostic tests. Age, cyanosis (symptom), and immunosuppression (comorbidity) were found to differentiate between SARS-CoV-2 infection and CRP infection.
Genome-Wide Identification of Mango (Mangifera indica L.) Polygalacturonases: Expression Analysis of Family Members and Total Enzyme Activity During Fruit Ripening
Mango ( .) is an important commercial fruit that shows a noticeable loss of firmness during ripening. Polygalacturonase (PG, E.C. 3.2.1.15) is a crucial enzyme for cell wall loosening during fruit ripening since it solubilizes pectin and its activity correlates with fruit softening. Mango PGs were mapped to a genome draft using seventeen PGs found in mango transcriptomes and 48 bonafide PGs were identified. The phylogenetic analysis suggests that they are related to , which may indicate a recent evolutive divergence and related functions with orthologs in the tree. Gene expression analysis for nine PGs showed differential expression for them during post-harvest fruit ripening, , , , , , , and were highly up-regulated. PG enzymatic activity also increased during maturation and these results correlate with the loss of firmness observed in mango during post-harvest ripening, between the ethylene production burst and the climacteric peak. The analysis of PGs promoter regions identified regulatory sequences associated to ripening such as MADS-box, ethylene regulation like ethylene insensitive 3 (EIN3) factors, APETALA2-like and ethylene response element factors. During mango fruit ripening the action of at least these nine PGs contribute to softening, and their expression is regulated at the transcriptional level. The prediction of the tridimensional structure of some PGs showed a conserved parallel beta-helical fold related to polysaccharide hydrolysis and a modular architecture, where exons correspond to structural elements. Further biotechnological approaches could target specific softening-related PGs to extend mango post-harvest shelf life.
Genome-wide identification of gene families related to miRNA biogenesis in Mangifera indica L. and their possible role during heat stress
Mango is a popular tropical fruit that requires quarantine hot water treatment (QHWT) for postharvest sanitation, which can cause abiotic stress. Plants have various defense mechanisms to cope with stress; miRNAs mainly regulate the expression of these defense responses. Proteins involved in the biogenesis of miRNAs include DICER-like (DCL), ARGONAUTE (AGO), HYPONASTIC LEAVES 1 (HYL1), SERRATE (SE), HUA ENHANCER1 (HEN1), HASTY (HST), and HEAT-SHOCK PROTEIN 90 (HSP90), among others. According to our analysis, the mango genome contains five DCL , thirteen AGO , six HYL , two SE , one HEN1 , one HST , and five putative HSP90 genes. Gene structure prediction and domain identification indicate that sequences contain key domains for their respective gene families, including the RNase III domain in DCL and PAZ and PIWI domains for AGOs. In addition, phylogenetic analysis indicates the formation of clades that include the mango sequences and their respective orthologs in other flowering plant species, supporting the idea these are functional orthologs. The analysis of cis -regulatory elements of these genes allowed the identification of MYB, ABRE, GARE, MYC, and MeJA-responsive elements involved in stress responses. Gene expression analysis showed that most genes are induced between 3 to 6 h after QHWT, supporting the early role of miRNAs in stress response. Interestingly, our results suggest that mango rapidly induces the production of miRNAs after heat stress. This research will enable us to investigate further the regulation of gene expression and its effects on commercially cultivated fruits, such as mango, while maintaining sanitary standards.
pic gene of enteroaggregative Escherichia coli and its association with diarrhea in Peruvian children
Enteroaggregative Escherichia coli (EAEC) causes acute and persistent diarrhea among children, HIV-infected patients, and travelers to developing countries. We have searched for 18 genes-encoding virulence factors associated with aggregative adherence, dispersion, biofilm, toxins, serine protease autotransporters of Enterobacteriaceae (SPATEs) and siderophores, analyzed in 172 well-characterized EAEC strains (aggR+) isolated from stool samples of 97 children with diarrhea and 75 healthy controls from a passive surveillance diarrhea cohort study in Peru. Eighty-one different genetic profiles were identified, 37 were found only associated with diarrhea and 25 with control samples. The most frequent genetic profile was aggC+aatA+aap+shf+fyuA+, present in 19 strains, including diarrhea and controls. The profile set1A+set1B+pic+ was associated with diarrhea (P < 0.05). Of all genes evaluated, the most frequent were aatA (CVD 342) present in 159 strains (92.4%) and fyuA in 157 (91.3%). When EAEC strains were analyzed as a single pathogen (excluding co-infections), only pic was associated with diarrhea (P < 0.05) and with prolonged diarrhea (diarrhea ≥ 7 days) (P < 0.05). In summary, this is the first report on the prevalence of a large set of EAEC virulence genes and its association with diarrhea in Peruvian children. More studies are needed to elucidate the exact role of each virulence factor. Eighteen genes-encoding virulence factors in EAEC strains were analyzed from stool samples of children with/without diarrhea. Only one gene (pic) was found more frequently in diarrhea than in control samples. Graphical Abstract Figure. Eighteen genes-encoding virulence factors in EAEC strains were analyzed from stool samples of children with/without diarrhea. Only one gene (pic) was found more frequently in diarrhea than in control samples.
A novel thymidylate synthase from the Vibrionales , Alteromonadales , Aeromonadales , and Pasteurellales (VAAP) clade with altered nucleotide and folate binding sites
Thymidylate synthase (TS, E.C. 2.1.1.45) is a crucial enzyme for de novo deoxythymidine monophosphate (dTMP) biosynthesis. The gene for this enzyme is thyA , which encodes the folate-dependent TS that converts deoxyuridine monophosphate group (dUMP) into (dTMP) using the cofactor 5,10-methylenetetrahydrofolate (mTHF) as a carbon donor. We identified the thyA gene in the genome of the Vibrio parahaemolyticus strain FIM-S1708+ that is innocuous to humans but pathogenic to crustaceans. Surprisingly, we found changes in the residues that bind the substrate dUMP and mTHF, previously postulated as invariant among all TSs known (Finer-Moore, Santi & Stroud, 2003). Interestingly, those amino acid changes were also found in a clade of microorganisms that contains Vibrionales , Alteromonadales , Aeromonadales , and Pasteurellales (VAAP) from the Gammaproteobacteria class. In this work, we studied the biochemical properties of recombinant TS from V. parahemolyticus FIM-S1708+ (VpTS) to address the natural changes in the TS amino acid sequence of the VAAP clade. Interestingly, the K m for dUMP was 27.3 ± 4.3 µM, about one-fold larger compared to other TSs. The K m for mTHF was 96.3 ± 18 µM, about three- to five-fold larger compared to other species, suggesting also loss of affinity. Thus, the catalytic efficiency was between one or two orders of magnitude smaller for both substrates. We used trimethoprim, a common antibiotic that targets both TS and DHFR for inhibition studies. The IC 50 values obtained were high compared to other results in the literature. Nonetheless, this molecule could be a lead for the design antibiotics towards pathogens from the VAAP clade. Overall, the experimental results also suggest that in the VAAP clade the nucleotide salvage pathway is important and should be investigated, since the de novo dTMP synthesis appears to be compromised by a less efficient thymidylate synthase.
Mango (Mangifera indica L.) cv. Kent fruit mesocarp de novo transcriptome assembly identifies gene families important for ripening
Fruit ripening is a physiological and biochemical process genetically programmed to regulate fruit quality parameters like firmness, flavor, odor and color, as well as production of ethylene in climacteric fruit. In this study, a transcriptomic analysis of mango (Mangifera indica L.) mesocarp cv. \"Kent\" was done to identify key genes associated with fruit ripening. Using the Illumina sequencing platform, 67,682,269 clean reads were obtained and a transcriptome of 4.8 Gb. A total of 33,142 coding sequences were predicted and after functional annotation, 25,154 protein sequences were assigned with a product according to Swiss-Prot database and 32,560 according to non-redundant database. Differential expression analysis identified 2,306 genes with significant differences in expression between mature-green and ripe mango [1,178 up-regulated and 1,128 down-regulated (FDR ≤ 0.05)]. The expression of 10 genes evaluated by both qRT-PCR and RNA-seq data was highly correlated (R = 0.97), validating the differential expression data from RNA-seq alone. Gene Ontology enrichment analysis, showed significantly represented terms associated to fruit ripening like \"cell wall,\" \"carbohydrate catabolic process\" and \"starch and sucrose metabolic process\" among others. Mango genes were assigned to 327 metabolic pathways according to Kyoto Encyclopedia of Genes and Genomes database, among them those involved in fruit ripening such as plant hormone signal transduction, starch and sucrose metabolism, galactose metabolism, terpenoid backbone, and carotenoid biosynthesis. This study provides a mango transcriptome that will be very helpful to identify genes for expression studies in early and late flowering mangos during fruit ripening.
Molecular modeling and expression analysis of a MADS-box cDNA from mango (Mangifera indica L.)
MADS - box genes are a large family of transcription factors initially discovered for their role during development of flowers and fruits. The MADS-box transcription factors from animals have been studied by X-ray protein crystallography but those from plants remain to be studied. In this work, a MADS - box cDNA from mango encoding a protein of 254 residues was obtained and compared. Based on phylogenetic analysis, it is proposed that the MADS-box transcription factor expressed in mango fruit (MiMADS1) belongs to the SEP clade of MADS-box proteins. MiMADS1 mRNA steady-state levels did not changed during mango fruit development and were up-regulated, when mango fruits reached physiological maturity as assessed by qRT-PCR. Thus, MiMADS1 could have a role during development and ripening of this fruit. The theoretical structural model of MiMADS1 showed the DNA-binding domain folding bound to a double-stranded DNA. Therefore, MiMADS1 is an interesting model for understanding DNA-binding for transcriptional regulation.
Estimating the future burden of multidrug-resistant and extensively drug-resistant tuberculosis in India, the Philippines, Russia, and South Africa: a mathematical modelling study
Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis are emerging worldwide. The Green Light Committee initiative supported programmatic management of drug-resistant tuberculosis in 90 countries. We used estimates from the Preserving Effective TB Treatment Study to predict MDR and XDR tuberculosis trends in four countries with a high burden of MDR tuberculosis: India, the Philippines, Russia, and South Africa. We calibrated a compartmental model to data from drug resistance surveys and WHO tuberculosis reports to forecast estimates of incident MDR and XDR tuberculosis and the percentage of incident MDR and XDR tuberculosis caused by acquired drug resistance, assuming no fitness cost of resistance from 2000 to 2040 in India, the Philippines, Russia, and South Africa. The model forecasted the percentage of MDR tuberculosis among incident cases of tuberculosis to increase, reaching 12·4% (95% prediction interval 9·4–16·2) in India, 8·9% (4·5–11·7) in the Philippines, 32·5% (27·0–35·8) in Russia, and 5·7% (3·0–7·6) in South Africa in 2040. It also predicted the percentage of XDR tuberculosis among incident MDR tuberculosis to increase, reaching 8·9% (95% prediction interval 5·1–12·9) in India, 9·0% (4·0–14·7) in the Philippines, 9·0% (4·8–14·2) in Russia, and 8·5% (2·5–14·7) in South Africa in 2040. Acquired drug resistance would cause less than 30% of incident MDR tuberculosis during 2000–40. Acquired drug resistance caused 80% of incident XDR tuberculosis in 2000, but this estimate would decrease to less than 50% by 2040. MDR and XDR tuberculosis were forecast to increase in all four countries despite improvements in acquired drug resistance shown by the Green Light Committee-supported programmatic management of drug-resistant tuberculosis. Additional control efforts beyond improving acquired drug resistance rates are needed to stop the spread of MDR and XDR tuberculosis in countries with a high burden of MDR tuberculosis. US Agency for International Development and US Centers for Disease Control and Prevention, Division of Tuberculosis Elimination.
“Like Someone Is Paying Attention to You, Listening to You, and Guiding You”: Acceptability of a Mental Health Chatbot Among Caregivers of Adolescents Living With HIV
BackgroundThis study assessed the acceptability, among caregivers, of a mental health chatbot designed for adolescents living with HIV aged 10 to 19 years.MethodsFifteen caregivers interacted with the mental health chatbot. Pre-post assessments and semistructured interviews evaluated acceptability. Data were analyzed using a Framework Analysis approach.ResultsCaregivers aged 31 to 70 years found the chatbot acceptable on individual, interpersonal, and environmental levels. They appreciated the educational content and self-help tools, feeling the chatbot would benefit them personally. Caregivers also saw potential in the chatbot to improve communication with their children, particularly during critical periods like HIV diagnosis. Despite concerns about data costs or internet access, most viewed the chatbot as an accessible supplement to traditional mental health services.ConclusionThis study suggests that a mental health chatbot for Peruvian adolescents living with HIV was acceptable to their caregivers, potentially benefiting caregivers' mental health, enhancing caregiver-adolescent interactions, and fostering better communication.
Lactobacillus reuteri DSM 17938 and Agave Inulin in Children with Cerebral Palsy and Chronic Constipation: A Double-Blind Randomized Placebo Controlled Clinical Trial
The main objective was to assess the efficacy of a probiotic (Lactobacillus reuteri DSM 17938), a prebiotic (agave inulin), and a synbiotic on the stool characteristics in children with cerebral palsy and chronic constipation. Thirty-seven children with cerebral palsy and chronic constipation were included. The probiotic group received 1 × 108 colony forming unit (cfu) of L. reuteri DSM 17938 plus placebo, the prebiotic group received 4 g of agave inulin plus placebo, the synbiotic group received L. reuteri DSM 17938 plus agave inulin, and the placebo group received two placebos for 28 days. The probiotic group showed a significant decrease in stool pH (p = 0.014). Stool consistency improved in the prebiotic group (p = 0.008). The probiotic, prebiotic, and synbiotic groups showed a significant improvement in the history of excessive stool retention, the presence of fecal mass in the rectum, and the history of painful defecation. L. reuteri concentration in feces was higher in the probiotic group than in the placebo group (p = 0.001) and showed an inverse correlation with stool pH in the probiotic group (r = −0.762, p = 0.028). This study showed that the use of L. reuteri DSM 17938 and/or agave inulin improved the stool characteristics such as the history of painful defecation and the presence of fecal mass in the rectum against placebo in children with cerebral palsy and chronic constipation.