RESUMO
OBJECTIVE: To assess the relative risk of mortality in infants born preterm and small for gestational age (SGA) during the first and second months of life in rural Bangladesh. STUDY DESIGN: We analyzed data from a cohort of pregnant women and their babies in Sylhet, Bangladesh, assembled between 2011 and 2014. Community health workers visited enrolled babies up to 10 times from birth to age 59 days. Survival status was recorded at each visit. Gestational age was estimated from mother's reported last menstrual period. Birth weights were measured within 72 hours of delivery. SGA was defined using the INTERGROWTH-21st standard. We estimated unadjusted and adjusted hazard ratios (HRs) and corresponding 95% CIs for babies born preterm and SGA separately for the first and second month of life using bivariate and multivariable weighted Cox regression models. RESULTS: The analysis included 17â643 singleton live birth babies. Compared with infants born at term-appropriate for gestational age, in both unadjusted and adjusted analyses, infants born preterm-SGA had the greatest risk of death in the first (HR 13.25, 95% CI 8.65-20.31; adjusted HR 12.05, 95% CI 7.82-18.57) and second month of life (HR 4.65, 95% CI 1.93-11.23; adjusted HR 4.1, 95% CI 1.66-10.15), followed by infants born preterm-appropriate for gestational age and term-SGA. CONCLUSIONS: The risk of mortality in infants born preterm and/or SGA is increased and extends through the second month of life. Appropriate interventions to prevent and manage complications caused by prematurity and SGA could improve survival during and beyond the neonatal period.
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Mortalidade Infantil , Recém-Nascido Prematuro , Recém-Nascido Pequeno para a Idade Gestacional , População Rural , Humanos , Bangladesh/epidemiologia , Recém-Nascido , Feminino , Estudos Prospectivos , População Rural/estatística & dados numéricos , Masculino , Lactente , Adulto , Gravidez , Idade Gestacional , Nascimento Prematuro/epidemiologia , Adulto Jovem , Estudos de CoortesRESUMO
BACKGROUND: Small-for-gestational-age (SGA), commonly caused by poor placentation, is a major contributor to global perinatal mortality and morbidity. Maternal serum levels of placental protein and angiogenic factors are changed in SGA. Using data from a population-based pregnancy cohort, we estimated the relationships between levels of second-trimester pregnancy-associated plasma protein-A (PAPP-A), placental growth factor (PlGF), and serum soluble fms-like tyrosine kinase-1 (sFlt-1) with SGA. METHODS: Three thousand pregnant women were enrolled. Trained health workers prospectively collected data at home visits. Maternal blood samples were collected, serum aliquots were prepared and stored at -80â. Included in the analysis were 1,718 women who delivered a singleton live birth baby and provided a blood sample at 24-28 weeks of gestation. We used Mann-Whitney U test to examine differences of the median biomarker concentrations between SGA (< 10th centile birthweight for gestational age) and appropriate-for-gestational-age (AGA). We created biomarker concentration quartiles and estimated the risk ratios (RRs) and 95% confidence intervals (CIs) for SGA by quartiles separately for each biomarker. A modified Poisson regression was used to determine the association of the placental biomarkers with SGA, adjusting for potential confounders. RESULTS: The median PlGF level was lower in SGA pregnancies (934 pg/mL, IQR 613-1411 pg/mL) than in the AGA (1050 pg/mL, IQR 679-1642 pg/mL; p < 0.001). The median sFlt-1/PlGF ratio was higher in SGA pregnancies (2.00, IQR 1.18-3.24) compared to AGA pregnancies (1.77, IQR 1.06-2.90; p = 0.006). In multivariate regression analysis, women in the lowest quartile of PAPP-A showed 25% higher risk of SGA (95% CI 1.09-1.44; p = 0.002). For PlGF, SGA risk was higher in women in the lowest (aRR 1.40, 95% CI 1.21-1.62; p < 0.001) and 2nd quartiles (aRR 1.30, 95% CI 1.12-1.51; p = 0.001). Women in the highest and 3rd quartiles of sFlt-1 were at reduced risk of SGA delivery (aRR 0.80, 95% CI 0.70-0.92; p = 0.002, and aRR 0.86, 95% CI 0.75-0.98; p = 0.028, respectively). Women in the highest quartile of sFlt-1/PlGF ratio showed 18% higher risk of SGA delivery (95% CI 1.02-1.36; p = 0.025). CONCLUSIONS: This study provides evidence that PAPP-A, PlGF, and sFlt-1/PlGF ratio measurements may be useful second-trimester biomarkers for SGA.
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Biomarcadores , Recém-Nascido Pequeno para a Idade Gestacional , Fator de Crescimento Placentário , Insuficiência Placentária , Segundo Trimestre da Gravidez , Proteína Plasmática A Associada à Gravidez , Receptor 1 de Fatores de Crescimento do Endotélio Vascular , Humanos , Feminino , Gravidez , Fator de Crescimento Placentário/sangue , Biomarcadores/sangue , Estudos Prospectivos , Adulto , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue , Proteína Plasmática A Associada à Gravidez/análise , Proteína Plasmática A Associada à Gravidez/metabolismo , Insuficiência Placentária/sangue , Recém-Nascido , Segundo Trimestre da Gravidez/sangue , Bangladesh/epidemiologia , Adulto Jovem , Idade Gestacional , Fatores de RiscoRESUMO
Antimicrobial resistance has recently been considered an emerging catastrophe globally. The public health and environmental threats were aggravated by the injudicious use of antibiotics in animal farming, aquaculture, and croup fields, etc. Consequently, failure of antibiotic therapies is common because of the emergence of multidrug-resistant (MDR) bacteria in the environment. Thus, the reduction in antibiotic spillage in the environment could be an important step for overcoming this situation. Bear in mind, this research was focused on the green synthesis of chitosan nanoparticles (ChiNPs) using Citrus lemon (Assam lemon) extract as a cross-linker and application in controlling MDR bacteria to reduce the antibiotic spillage in that sector. For evaluating antibacterial activity, Staphylococcus aureus and Escherichia coli were isolated from environmental specimens, and their multidrug-resistant pattern were identified both phenotypically by disk diffusion and genotypically by detecting methicillin- (mecA), penicillin- (blaZ), and streptomycin (aadA1)-resistance encoding genes. The inhibitory zone's diameter was employed as a parameter for determining the antibacterial effect against MDR bacteria revealing 30 ± 0.4 mm, 34 ± 0.2 mm, and 36 ± 0.8 mm zones of inhibition against methicillin- (mecA) and penicillin (blaZ)-resistant S. aureus, and streptomycin (aadA1)-resistant E. coli, respectively. The minimum inhibitory concentration at 0.31 mg/mL and minimum bactericidal concentration at 0.62 mg/mL of yielded ChiNPs were used as the broad-spectrum application against MDR bacteria. Finally, the biocompatibility of ChiNPs was confirmed by showing a negligible decrease in BHK-21 cell viability at doses less than 2 MIC, suggesting their potential for future application in antibiotic-free farming practices.
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Antibacterianos , Quitosana , Farmacorresistência Bacteriana Múltipla , Escherichia coli , Nanopartículas , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Quitosana/farmacologia , Quitosana/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Química Verde , Testes de Sensibilidade Microbiana , Nanopartículas/química , Proteínas de Ligação às Penicilinas/genética , Proteínas de Ligação às Penicilinas/metabolismo , Proteínas de Ligação às Penicilinas/antagonistas & inibidores , Staphylococcus aureus/efeitos dos fármacosRESUMO
Turmeric (Curcuma longa) contains curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC). Nevertheless, curcumin is the most researched active ingredient for its numerous pharmacological effects. We investigated the impact of these curcuminoids found in Ryudai gold, an approved cultivar of Curcuma longa, on wound healing, inflammation, and diabetes. Sub-planter injections of carrageenan induced acute paw inflammation in rats. The wound-healing ability of 1% curcuminoids was examined by making a 6 mm round wound on the shaved dorsum of the mice with a biopsy punch. A single intraperitoneal injection of streptozotocin (50 mg/kg) was used to induce diabetes in mice. Curcuminoids at a dose rate of 100 mg/kg body weight were used with feed and as a gastric gavage to treat diabetes and inflammation in experimental animals. Paw thickness was measured at 1, 3, and 6 h following carrageenan injection. After three hours, mean paw volume was 58% in carrageenan-injected mice, which was 35%, 37%, and 31% in the curcumin, DMC, and BDMC groups, respectively. Histopathology of the paw tissue demonstrated severe infiltration of inflammatory cells and thickening of the dermis, which were remarkably improved by the curcuminoids. The wound-healing abilities were significantly higher in the curcumin- (95.0%), DMC- (93.17%), and BDMC-treated (89.0%) groups, in comparison to that of the control (65.09%) group at day nine. There were no significant differences in wound-healing activity among the groups treated with 1% curcuminoids throughout the study. Streptozotocin-induced diabetes was characterized by an increased blood glucose (552.2 mg/dL) and decreased body weight (31.2 g), compared to that of the control rats (145.6 mg/dL and 46.8 g blood glucose and body weight, respectively). It also caused an increase in serum alanine aminotransferase (ALT; 44.2 U/L) and aspartate aminotransferase (AST; 55.8 U/L) compared to that of the control group (18.6 U/L and 20.1 U/L, respectively). Histopathological examination of the liver showed that diabetes caused hepatic cellular necrosis, congestion of the central vein, and parenchymatous degeneration. However, all three curcuminoids significantly decreased blood glucose levels, ALT, and AST and improved the histopathological score of the liver. These results evidenced that not only curcumin but also DMC and BDMC have potent anti-inflammatory, wound healing, and anti-diabetic efficacy, and the Ryudai gold variety of turmeric could be used as a functional food supplement.
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Anti-Inflamatórios , Curcuma , Curcumina , Diabetes Mellitus Experimental , Hipoglicemiantes , Cicatrização , Animais , Curcuma/química , Cicatrização/efeitos dos fármacos , Camundongos , Ratos , Diabetes Mellitus Experimental/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Hipoglicemiantes/farmacologia , Hipoglicemiantes/química , Curcumina/farmacologia , Curcumina/análogos & derivados , Masculino , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Carragenina , Inflamação/tratamento farmacológico , Inflamação/patologia , Diarileptanoides/farmacologia , Diarileptanoides/químicaRESUMO
Mikania micrantha is utilized as a therapeutic for the treatment of various human ailments including insect bites, rashes and itches of skin, chicken pox, healing of sores and wounds, colds and fever, nausea, jaundice, rheumatism, and respiratory ailments. This study aimed at summarizing the traditional uses, phytochemical profile, and biological activities of M. micrantha based on obtainable information screened from different databases. An up-to-date search was performed on M. micrantha in PubMed, Science Direct, clinicaltrials.gov, and Google Scholar databases with specific keywords. No language restrictions were imposed. Published articles, theses, seminar/conference papers, abstracts, and books on ethnobotany, phytochemistry and pharmacological evidence were considered. Based on the inclusion criteria, this study includes 53 published records from the above-mentioned databases. The results suggest that fresh leaves and whole plant are frequently used in folk medicine. The plant contains more than 150 different phytochemicals under the following groups: essential oils, phenolics and flavonoids, terpenes, terpene lactones, glycosides, and sulfated flavonoids. It contains carbohydrates and micronutrients including vitamins and major and trace minerals. M. micrantha possesses antioxidant, anti-inflammatory, anti-microbial, anti-dermatophytic, anti-protozoal, anthelmintic, cytotoxic, anxiolytic, anti-diabetic, lipid-lowering and antidiabetic, spasmolytic, memory-enhancing, wound-healing, anti-aging, and thrombolytic activities. No clinical studies have been reported to date. M. micrantha might be one of the potential sources of phytotherapeutic compounds against diverse ailments in humans. Studies are required to confirm its safety profile in experimental animals prior to initiating clinical trials. Moreover, adequate investigation is also crucial to clarify exact mechanism of action for each biological effect.
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Mikania , Plantas Medicinais , Animais , Humanos , Fitoterapia , Etnofarmacologia , Etnobotânica , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Flavonoides , Extratos Vegetais/químicaRESUMO
Multiple harmful health effects can have on the population from non-ionizing radiation (NIR) sources. To date, there has been no extensive data collection about NIR emitted from base transceiver stations in Dhaka City, Bangladesh. This study aims to remedy that by collecting data and comparing the processed data to the international standards, International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines, and standards of other countries. For this, measurement data were collected from 361 different publicly accessible locations in Dhaka City applying a convenience sampling approach. The measured average electric field exceeded the 1800 MHz threshold values of 36.84, 33.5, and 7.5% of the time compared with the thresholds of China, India, and Japan, respectively, followed by the measured average electromagnetic field values, which were 57, 52, and 29%, respectively. No exceedance was seen for radiofrequency power flux for the investigated countries. Approximately 35% of the calculated average specific energy absorption rate values exceeded the ICNIRP recommended public exposure limit of 0.08 W/kg. Based on this data, it is suggested that detailed NIR exposure regulations need to be created and proper oversight and enforcement over operators are required to avoid potential health effects.
Assuntos
Monitoramento Ambiental , Radiação não Ionizante , Bangladesh , Ondas de Rádio , PercepçãoRESUMO
Epilepsy is a complex neurological condition that affects a large number of people worldwide. Electroencephalography (EEG) measures the electrical activity of the brain and is widely used in epilepsy diagnosis, but it usually requires manual inspection, which can be hours long, by a neurologist. Several automatic systems have been proposed to detect epilepsy but still have some unsolved issues. In this study, we proposed a dynamic method using a deep learning model (Epileptic-Net) to detect an epileptic seizure. The proposed method is largely heterogeneous and comprised of the dense convolutional blocks (DCB), feature attention modules (FAM), residual blocks (RB), and hypercolumn technique (HT). Firstly, DCB is used to get the discriminative features from the EEG samples. Then, FAM extracts the essential features from the samples. After that, RB learns more vital parts as it entirely uses information in the convolutional layer. Finally, HT retains the efficient local features extracted from the layers situated at the different levels of the model. Its performance has been evaluated on the University of Bonn EEG dataset, divided into five distinct classes. The proposed Epileptic-Net achieves the average accuracy of 99.95% in the two-class classification, 99.98% in the three-class classification, 99.96% in the four-class classification, and 99.96% in classifying the complicated five-class problem. Thus the proposed approach shows more competitive results than the existing model to detect epileptic seizures. We also hope that this method can support experts in achieving objective and reliable results, lowering the misdiagnosis rate, and assisting in decision-making.
Assuntos
Epilepsia , Processamento de Sinais Assistido por Computador , Eletroencefalografia , Epilepsia/diagnóstico , Humanos , ConvulsõesRESUMO
The current era is notably characterized by the major advances in communication technologies. The increased connectivity has been transformative in terrestrial, space, and undersea applications. Nonetheless, the water medium imposes unique constraints on the signals that can be pursued for establishing wireless links. While numerous studies have been dedicated to tackling the challenges for underwater communication, little attention has been paid to effectively interfacing the underwater networks to remote entities. Particularly it has been conventionally assumed that a surface node will be deployed to act as a relay using acoustic links for underwater nodes and radio links for air-based communication. Yet, such an assumption could be, in fact, a hindrance in practice. The paper discusses alternative means by allowing communication across the air-water interface. Specifically, the optoacoustic effect, also referred to as photoacoustic effect, is being exploited as a means for achieving connectivity between underwater and airborne nodes. The paper provides background, discusses technical challenges, and summarizes progress. Open research problems are also highlighted.
Assuntos
Acústica , Redes de Comunicação de Computadores , Comunicação , ÁguaRESUMO
Human activity recognition (HAR) has emerged as a significant area of research due to its numerous possible applications, including ambient assisted living, healthcare, abnormal behaviour detection, etc. Recently, HAR using WiFi channel state information (CSI) has become a predominant and unique approach in indoor environments compared to others (i.e., sensor and vision) due to its privacy-preserving qualities, thereby eliminating the need to carry additional devices and providing flexibility of capture motions in both line-of-sight (LOS) and non-line-of-sight (NLOS) settings. Existing deep learning (DL)-based HAR approaches usually extract either temporal or spatial features and lack adequate means to integrate and utilize the two simultaneously, making it challenging to recognize different activities accurately. Motivated by this, we propose a novel DL-based model named spatio-temporal convolution with nested long short-term memory (STC-NLSTMNet), with the ability to extract spatial and temporal features concurrently and automatically recognize human activity with very high accuracy. The proposed STC-NLSTMNet model is mainly comprised of depthwise separable convolution (DS-Conv) blocks, feature attention module (FAM) and NLSTM. The DS-Conv blocks extract the spatial features from the CSI signal and add feature attention modules (FAM) to draw attention to the most essential features. These robust features are fed into NLSTM as inputs to explore the hidden intrinsic temporal features in CSI signals. The proposed STC-NLSTMNet model is evaluated using two publicly available datasets: Multi-environment and StanWiFi. The experimental results revealed that the STC-NLSTMNet model achieved activity recognition accuracies of 98.20% and 99.88% on Multi-environment and StanWiFi datasets, respectively. Its activity recognition performance is also compared with other existing approaches and our proposed STC-NLSTMNet model significantly improves the activity recognition accuracies by 4% and 1.88%, respectively, compared to the best existing method.
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Atividades Humanas , Redes Neurais de Computação , Humanos , Movimento (Física)RESUMO
We have developed a novel bioorthogonal reaction that can selectively displace fluorine substitutions alpha to amide bonds. This fluorine-thiol displacement reaction (FTDR) allows for fluorinated cofactors or precursors to be utilized as chemical reporters, hijacking acetyltransferase-mediated acetylation both in vitro and in live cells, which cannot be achieved with azide- or alkyne-based chemical reporters. The fluoroacetamide labels can be further converted to biotin or fluorophore tags using FTDR, enabling the general detection and imaging of acetyl substrates. This strategy may lead to a steric-free labeling platform for substrate proteins, expanding our chemical toolbox for functional annotation of post-translational modifications in a systematic manner.
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Acetilcoenzima A/metabolismo , Acetiltransferases/metabolismo , Sondas Moleculares/metabolismo , Compostos de Sulfidrila/química , Acetilcoenzima A/química , Acetilação , Biotina/análogos & derivados , Corantes Fluorescentes/química , Células HEK293 , Humanos , Sondas Moleculares/química , Estrutura Molecular , Estudo de Prova de Conceito , Rodaminas/químicaRESUMO
Zero-valent iron amended biochar (ZVIB) has been proposed as a promising material in immobilizing heavy metals in paddy fields. In this study, the impacts of pH of ZVIB (pH 6.3 and pH 9.7) and watering management techniques (watering amount in the order of CON (control, 5/72)>3/72>1-3/72>3/100>1/72, with 5/72, for example, representing irrigation given to 5 cm above soil surface in 72 hr regular interval) on As and Cd bioavailability for rice and its grain yield (YieldBR) were investigated in a pot experiment. Brown rice As (AsBR) content was irrelative to the watering treatments, while significantly decreased (>50%) with the addition of both ZVIB materials. The diminutions of brown rice Cd (CdBR) content as well as the YieldBR were highly dependent on both the soil amendment materials' pH and watering amount. Among all the watering treatments, 3/72 treatment (15% less irrigation water than the CON) with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of AsBR (50%) and CdBR contents (19%) as well as for significant increment (12%) of the YieldBR. Although high pH (9.7) ZVIB application could also efficiently decrease As and Cd contents in brown rice, it might risk grain yield lost if appropriate (e.g. 3/72 in our study) watering management technique was not chosen. Therefore, ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.
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Oryza , Poluentes do Solo , Cádmio/análise , Carvão Vegetal , Concentração de Íons de Hidrogênio , Ferro , Rizosfera , Solo , Poluentes do Solo/análise , ÁguaRESUMO
BACKGROUND: Enteric fever causes substantial morbidity and mortality in low- and middle-income countries. Here, we analyzed Surveillance for Enteric Fever in Asia Project (SEAP) data to estimate the burden of enteric fever hospitalization among children aged <15 years and identify risk factors for hospitalization in Bangladesh. METHODS: SEAP used hospital surveillance paired with a community-based health-care utilization assessment. In SEAP hospital surveillance, blood was obtained for culture from children aged <15 years with ≥3 days of fever. In the hospital catchment area, a health-care utilization survey (HCUS) was conducted to estimate the proportion of febrile children hospitalized at the study hospitals. We analyzed hospital surveillance and HCUS data to estimate the health care-adjusted incidence of enteric fever hospitalization, and conducted univariable and multivariable logistic regressions. RESULTS: From July 2017 through June 2019, 2243 laboratory-confirmed enteric fever cases were detected in 2 study hospitals; 673 (30%) were hospitalized. The health care-adjusted incidence of enteric fever hospitalization among children <15 years old was 303/100 000 children/year (95% confidence interval [CI], 293-313). Salmonella Typhi contributed most to the enteric fever hospitalization incidence (277/100 000 children/year; 95% CI, 267-287). The incidence was highest among children aged 2 to <5 years (552/100 000 children/year; 95% CI, 522-583), followed by those aged <2 years (316/100 000 children/year; 95% CI, 288-344). Factors independently associated with enteric fever hospitalization included fever duration, diarrhea, vomiting, abdominal pain, and leukocytopenia. CONCLUSIONS: We estimated a high burden of hospitalization due to enteric fever among children aged <5 years in Bangladesh. The introduction of a typhoid conjugate vaccine would protect children from typhoid and avert typhoid hospitalizations.
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Febre Tifoide , Adolescente , Ásia , Bangladesh/epidemiologia , Criança , Pré-Escolar , Hospitalização , Humanos , Incidência , Lactente , Fatores de Risco , Salmonella typhi , Febre Tifoide/epidemiologiaRESUMO
Spirochaetes are spiral or flat-wave-shaped Gram-negative bacteria that have periplasmic flagella between the peptidoglycan layer and outer membrane. Rotation of the periplasmic flagella transforms the cell body shape periodically, allowing the cell to swim in aqueous environments. Because the virulence of motility-deficient mutants of pathogenic species is drastically attenuated, motility is thought to be an essential virulence factor in spirochaetes. However, it remains unknown how motility practically contributes to the infection process. We show here that the cell body configuration and motility of the zoonotic spirochaete Leptospira changes depending on the viscosity of the medium. Leptospira swim and reverse the swimming direction by transforming the cell body. Motility analysis showed that the frequency of cell shape transformation was increased by increasing the viscosity of the medium. The increased cell body transformation induced highly frequent reversal of the swimming direction. A simple kinetic model based on the experimental results shows that the viscosity-induced increase in reversal limits cell migration, resulting in the accumulation of cells in high-viscosity regions. This behaviour could facilitate the colonization of the spirochaete on host tissues covered with mucosa.
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Leptospira , Mucosa/fisiologia , Viscosidade , Flagelos , Leptospira/citologia , Leptospira/patogenicidade , Leptospira/fisiologia , Mucosa/microbiologia , Fatores de Virulência/fisiologiaRESUMO
Bacterial chemotaxis is induced by sensing chemical stimuli via chemoreceptors embedded in the cytoplasmic membrane, enabling the cells to migrate toward nutrients or away from toxins. The chemoreceptors of Escherichia coli and Salmonella spp. have been well studied and are functionally classified on the basis of detectable substrates. The spirochete Leptospira possesses more than ten chemoreceptors and shows attractive or repellent responses against some sugars, amino acids, and fatty acids. However, the roles of these chemoreceptors have not been investigated. In this study, we conducted a chemotaxis assay called microscopic agar drop assay in combination with competition experiments, determining whether two kinds of attractants are recognized by the same type of chemoreceptor in the saprophytic Leptospira strain, Leptospira biflexa. Analyzing the competition effect observed between several pairs of chemicals, we found that L. biflexa senses sugars via chemoreceptors different from those that sense amino acids and fatty acids.
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Proteínas de Bactérias/metabolismo , Bioensaio/métodos , Quimiotaxia , Leptospira/fisiologia , Microscopia/métodos , Aminoácidos/metabolismo , Proteínas de Bactérias/genética , Bioensaio/instrumentação , Metabolismo dos Carboidratos , Leptospira/genéticaRESUMO
Leptospira is a spirochete possessing intracellular flagella. Each Leptospira flagellar filament is linked with a flagellar motor composed of a rotor and a dozen stators. For many bacterial species, it is known that the stator functions as an ion channel and that the ion flux through the stator is coupled with flagellar rotation. The coupling ion varies depending on the species; for example, H(+) is used in Escherichia coli, and Na(+) is used in Vibrio spp. to drive a polar flagellum. Although genetic and structural studies illustrated that the Leptospira flagellar motor also contains a stator, the coupling ion for flagellar rotation remains unknown. In the present study, we analyzed the motility of Leptospira under various pH values and salt concentrations. Leptospira cells displayed motility in acidic to alkaline pH. In the presence of a protonophore, the cells completely lost motility in acidic to neutral pH but displayed extremely slow movement under alkaline conditions. This result suggests that H(+) is a major coupling ion for flagellar rotation over a wide pH range; however, we also observed that the motility of Leptospira was significantly enhanced by the addition of Na(+), though it vigorously moved even under Na(+)-free conditions. These results suggest that H(+) is preferentially used and that Na(+) is secondarily involved in flagellar rotation in Leptospira. The flexible ion selectivity in the flagellar system could be advantageous for Leptospira to survive in a wide range of environment.
Assuntos
Flagelos/metabolismo , Leptospira/fisiologia , Prótons , Sódio/metabolismoRESUMO
Engaging in regular physical activity offers a myriad of benefits, including the improvement of mental health, social well-being, and cognitive function. Unfortunately, obstacles, such as transportation constraints, time limitations, and inadequate exercise facilities, hinder the regular participation of older adults in physical activity. Online group physical activity programs present a promising solution to enhance the involvement of older adults; however, several barriers impede their effective utilization. To explore these barriers and benefits, we conducted semi-structured interviews with participants and instructors of a community-based exercise program. Thematic analysis of interviews with 12 physical activity instructors and eight program participants unveiled key hindrances, including limited awareness and accessibility of online programs, challenges in assessing performance during exercise sessions, lack of social component, and technological difficulties. On the positive side, the benefits encompass convenience, wide accessibility, and enhanced social comfort. We also deliberate on future considerations to further bolster participation in these programs.
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A 17-year-old girl with a congenital, painless right forehead swelling obstructing her visual field was diagnosed with sinus pericranii. Radiological imaging confirmed extracalvarial arteriovenous malformation with serpentine vessels and bony erosion. Endovascular surgery was chosen for management, highlighting the necessity of considering SP in differential diagnosis for scalp swellings. Despite its rarity, awareness of it is essential to prevent complications from injury, misdiagnosis, or invasive procedures.
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BACKGROUND: To delineate the epidemiological landscape of glaucoma using a population-based sample representative of Bangladesh. METHODS: Using multistage stratified cluster random sampling, households were selected to identify individuals ≥35 years across all 8 divisions of Bangladesh. Sampling frames were derived from the 2011 national census. Fifty-eight study examination sites were set up for comprehensive eye evaluations, including intraocular pressure, gonioscopy and visual field testing when indicated. International Society for Geographic and Epidemiological Ophthalmology definitions were used to define glaucoma and glaucoma suspect cases. RESULTS: One hundred forty clusters (89 rural and 51 urban) were randomly selected, and 13 791 residential households were visited. We invited 17 002 individuals ≥35 years for on-site examination, of which 12 000 (71%) complied, with a male-to-female ratio of 1:1. The prevalence of glaucoma was 3.2% (95% CI 2.79% to 3.64%), and glaucoma suspect was 10.1% (95% CI 9.05% to 11.12%). The majority (78%) had primary open-angle glaucoma (POAG), while angle closure was seen in 16%. Of the POAG, 83% (n=251) were normal-tension glaucoma. Multivariable logistic regression showed increasing age (OR=1.01 for every 5-year increment, 95% CI 1 to 1.01) and male gender (OR=1.43, 95% CI 1.15 to 1.77) to be associated with an increased risk of glaucoma. CONCLUSIONS: The prevalence of glaucoma in Bangladesh is 3.2% in ≥35-year-old individuals with older men most at risk. Extrapolating the results, we estimate about 2 million patients with glaucoma. Though normal-tension variety was the most common type, caution should be exercised in generalising these results to other populations.
Assuntos
Glaucoma de Ângulo Fechado , Glaucoma de Ângulo Aberto , Hipertensão Ocular , Adulto , Idoso , Feminino , Humanos , Masculino , Bangladesh/epidemiologia , Estudos Transversais , Glaucoma de Ângulo Fechado/epidemiologia , Glaucoma de Ângulo Aberto/diagnóstico , PrevalênciaRESUMO
Biofilm development significantly enhances the virulence of methicillin-resistant Staphylococcus aureus (MRSA), leading to severe infections and decreased susceptibility to antibiotics, especially in strains associated with hospital environments. This study examined the occurrence of MRSA, their ability to form biofilms, agr typing, and the antibiotic resistance profiles of biofilm-forming MRSA strains isolated from environmental surfaces at Mymensingh Medical College Hospital (MMCH). From 120 swab samples, 86 (71.67%) tested positive for S. aureus. MRSA was identified in 86 isolates using the disk diffusion technique, and by polymerase chain reaction (PCR), 56 (65.1%) isolates were confirmed to carry the mecA gene. The Crystal Violet Microtiter Plate (CVMP) test revealed that 80.35% (45 isolates) were biofilm-forming and 19.6% (11 isolates) were non-biofilm-forming. Out of 45 biofilm producer isolates 37.5% and 42.9% isolates exhibited strong and intermediate biofilm-forming characteristics, respectively. Molecular analysis revealed that 17.78% of MRSA isolates carried at least one gene related to biofilm formation, specifically icaA, icaB, and icaD genes were discovered in 13.33%, 8.89%, 6.67% of the MRSA isolates, respectively. In agr typing, the most prevalent group was agr I (71.11%), followed by group III (17.78%) and group II (11.11%). Group IV was not detected. The distribution of agr gene groups showed a significant difference among biofilm-forming isolates (p < 0.05). In agr group I, 18.75% of isolates carried the icaA gene, 12.5% carried the icaB gene, and 9.37% carried the icaD gene. Biofilm-forming genes were not detected in any of the isolates from agr groups II or III. There are no statistically significant differences between agr groups and the presence of these genes (p > 0.05). Antibiotic resistance varied significantly among agr groups, with agr group I displaying the highest resistance, agr group II, and agr group III exhibiting the least resistance (p < 0.05). Seventy-three (73.3%) of the isolates were multi-drug resistant, with agr group I displaying nineteen MDR patterns. The occurrence of MRSA in hospital environments and their capacity to form biofilm raises concerns for public health. These findings support the importance of further research focused on agr quorum sensing systems as a basis for developing novel antibacterial agents.
Assuntos
Proteínas de Bactérias , Biofilmes , Staphylococcus aureus Resistente à Meticilina , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/fisiologia , Proteínas de Bactérias/genética , Humanos , Antibacterianos/farmacologia , Hospitais , Testes de Sensibilidade Microbiana , Transativadores/genética , Infecções Estafilocócicas/microbiologiaRESUMO
Background: Preterm birth (PTB) and its complications are important public health problems. Its aetiology is multifactorial and involves both modifiable and non-modifiable factors. Among the modifiable risk factors, micronutrient deficiencies, including maternal folate deficiency, are increasingly being studied in PTB. In this study, we estimated the prevalence of folate deficiency during pregnancy and examined its association with PTB among rural Bangladeshi women. Methods: We conducted a nested case-control study using data from a population-based cohort of 3000 pregnant women who were enrolled between 8 and 19 weeks of gestation following ultrasound confirmation of gestational age. Sociodemographic, epidemiologic, clinical, and pregnancy outcomes data were collected through home visits, while blood samples were collected at enrolment and 24-28 weeks of gestation during pregnancy. We included all women who delivered preterm (defined as live births <37 weeks of gestation) as cases (n = 235) and a random sample of women having a term birth as controls (n = 658). The main exposure was folate concentrations in maternal serum during 24-28 weeks of pregnancy. We categorised women into folate deficient (<3 ng/mL) and not deficient (≥3 ng/mL). We then performed multivariable logistic regression analysis to examine the association between maternal folate levels and PTB, adjusting for relevant covariates. Results: Thirty-eight per cent of the enrolled pregnant women were folate deficient. Maternal serum folate deficiency was significantly associated with PTB (adjusted OR (aOR) = 1.73; 95% confidence interval (CI) = 1.27-2.36). The risk of PTB was also higher among women who were of short stature (aOR = 1.83; 95% CI = 1.27-2.63), primiparous (aOR = 1.60; 95% CI = 1.15-2.22), and had exposure to passive smoking (aOR = 1.54; 95% CI = 1.02-2.31). Conclusions: The prevalence of folate deficiency was high among pregnant women in rural Bangladesh, and folate deficiency was significantly associated with an increased risk of preterm birth.