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1.
Environ Res ; 261: 119714, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39094898

RESUMO

BACKGROUND: Spina bifida is a type of neural tube defect (NTD); NTDs are developmental malformations of the spinal cord that result from failure of neural tube closure during embryogenesis and are likely caused by interactions between genetic and environmental factors. Arsenic induces NTDs in animal models, and studies demonstrate that mice with genetic defects related to folate metabolism are more susceptible to arsenic's effects. We sought to determine whether 25 single-nucleotide polymorphisms (SNPs) in genes involved in folate and arsenic metabolism modified the associations between maternal arsenic exposure and risk of spina bifida (a common NTD) among a hospital-based case-control study population in Bangladesh. METHODS: We used data from 262 mothers and 220 infants who participated in a case‒control study at the National Institutes of Neurosciences & Hospital and Dhaka Shishu Hospital in Dhaka, Bangladesh. Neurosurgeons assessed infants using physical examinations, review of imaging, and we collected histories using questionnaires. We assessed arsenic from mothers' toenails using inductively coupled plasma mass spectrometry (ICP-MS), and we genotyped participants using the Illumina Global Screening Array v1.0. We chose candidate genes and SNPs through a review of the literature. We assessed SNP-environment interactions using interaction terms and stratified models, and we assessed gene-environment interactions using interaction sequence/SNP-set kernel association tests (iSKAT). RESULTS: The median toenail arsenic concentration was 0.42 µg/g (interquartile range [IQR]: 0.27-0.86) among mothers of cases and 0.47 µg/g (IQR: 0.30-0.97) among mothers of controls. We found an two SNPs in the infants' AS3MT gene (rs11191454 and rs7085104) and one SNP in mothers' DNMT1 gene (rs2228611) were associated with increased odds of spina bifida in the setting of high arsenic exposure (rs11191454, OR 3.01, 95% CI: 1.28-7.09; rs7085104, OR 2.33, 95% CI: 1.20-4.and rs2228611, OR 2.11, 95% CI: 1.11-4.01), along with significant SNP-arsenic interactions. iSKAT analyses revealed significant interactions between mothers' toenail concentrations and infants' AS3MT and MTR genes (p = 0.02), and mothers' CBS gene (p = 0.05). CONCLUSIONS: Our results support the hypothesis that arsenic increases spina bifida risk via interactions with folate and arsenic metabolic pathways and suggests that individuals in the population who have certain genetic polymorphisms in genes involved with arsenic and folate metabolism may be more susceptible than others to the arsenic teratogenicity.

2.
Lancet Reg Health Southeast Asia ; 28: 100450, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39130755

RESUMO

Background: Ventilator-associated pneumonia (VAP) is a major cause of morbidity and mortality in patients receiving mechanical ventilation in India. Surveillance of VAP is essential to implement data-based preventive measures. Implementation of ventilator-associated events (VAE) criteria for surveillance has major constraints for low resource settings, which can lead to significant underreporting. Surveillance of VAP using common protocols in a large network of hospitals would give meaningful estimates of the burden of VAP in low resource settings. This study leverages a previously established healthcare-associated infections (HAI) surveillance network to develop and test a modified VAP definition adjusted for Indian settings. Methods: In this observational pilot study, thirteen hospitals from the existing HAI surveillance network were selected for developing and testing a modified VAP definition between February 2021 and April 2023. The criteria used for diagnosing VAP were adapted from the CDC's Pediatric VAP definition and modified to cater to the needs of Indian hospitals. Designated nurses recorded each VAP event in a case report form (CRF) and also collected denominator data. The data was entered into an indigenously developed database for validation and analysis. At the time of data analysis, a questionnaire was sent to sites to get feedback on the performance of the modified VAP definitions. Findings: Out of 133,445 patient days and 40,533 ventilator days, 261 VAP events were recorded, with an overall VAP rate of 6.4 per 1000 ventilator days and a device utilization ratio (DUR) of 0.3. A total of 344 organisms were reported from the VAP events. Of these, Acinetobacter spp (29.6%, 102) was the most frequent, followed by Klebsiella spp (26.7%, 92). Isolates of Acinetobacter spp (98%) and Enterobacterales (85.5%) showed very high resistance against Carbapenem. Colistin resistance was observed in 6% of Enterobacterales and 3.2% of Acinetobacter spp. Interpretation: Data from this pilot study needs to validated in the larger Indian HAI surveillance network so that it can help in wider implementation of this protocol in order to assess its applicability p VAP across India. Funding: This work was supported by a grant received from the Indian Council of Medical Research (code I-1203).

3.
Environ Health ; 23(1): 51, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831396

RESUMO

BACKGROUND: Spina bifida, a developmental malformation of the spinal cord, is associated with high rates of mortality and disability. Although folic acid-based preventive strategies have been successful in reducing rates of spina bifida, some areas continue to be at higher risk because of chemical exposures. Bangladesh has high arsenic exposures through contaminated drinking water and high rates of spina bifida. This study examines the relationships between mother's arsenic exposure, folic acid, and spina bifida risk in Bangladesh. METHODS: We conducted a hospital-based case-control study at the National Institute of Neurosciences & Hospital (NINS&H) in Dhaka, Bangladesh, between December 2016 and December 2022. Cases were infants under age one year with spina bifida and further classified by a neurosurgeon and imaging. Controls were drawn from children seen at NINS&H and nearby Dhaka Shishu Hospital. Mothers reported folic acid use during pregnancy, and we assessed folate status with serum assays. Arsenic exposure was estimated in drinking water using graphite furnace atomic absorption spectrophotometry (GF-AAS) and in toenails using inductively coupled plasma mass spectrometry (ICP-MS). We used logistic regression to examine the associations between arsenic and spina bifida. We used stratified models to examine the associations between folic acid and spina bifida at different levels of arsenic exposure. RESULTS: We evaluated data from 294 cases of spina bifida and 163 controls. We did not find a main effect of mother's arsenic exposure on spina bifida risk. However, in stratified analyses, folic acid use was associated with lower odds of spina bifida (adjusted odds ratio [OR]: 0.50, 95% confidence interval [CI]: 0.25-1.00, p = 0.05) among women with toenail arsenic concentrations below the median value of 0.46 µg/g, and no association was seen among mothers with toenail arsenic concentrations higher than 0.46 µg/g (adjusted OR: 1.09, 95% CI: 0.52-2.29, p = 0.82). CONCLUSIONS: Mother's arsenic exposure modified the protective association of folic acid with spina bifida. Increased surveillance and additional preventive strategies, such as folic acid fortification and reduction of arsenic, are needed in areas of high arsenic exposure.


Assuntos
Arsênio , Ácido Fólico , Disrafismo Espinal , Humanos , Ácido Fólico/uso terapêutico , Bangladesh/epidemiologia , Disrafismo Espinal/prevenção & controle , Disrafismo Espinal/epidemiologia , Disrafismo Espinal/induzido quimicamente , Estudos de Casos e Controles , Feminino , Arsênio/análise , Lactente , Masculino , Adulto , Recém-Nascido , Gravidez , Poluentes Químicos da Água/análise , Exposição Materna , Adulto Jovem , Água Potável/química , Água Potável/análise
4.
Lung India ; 41(3): 200-208, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38687231

RESUMO

BACKGROUND: In recent years, a significant understanding of delivering optimal aerosol therapy and the availability of various drugs and devices have led to an increase in its use in clinical practice. There are only a few studies available regarding their use in critically ill patients from a few parts of the world. We aimed to study the practice pattern of aerosol therapy in critically ill patients from Indian intensive care units (ICUs). METHODS: After ethical approval, this multi-centric prospective observational study was performed over a study period of four weeks. Newly admitted adult patients considered who had an artificial airway and/or ventilation (including non-invasive). Patients were followed up for the next 14 days or until ICU discharge/death (whichever came first) for details of each aerosol therapy, including ongoing respiratory support, drug type, and aerosol-generating device. RESULTS: From the nine participating centers across India, 218 patients were enrolled. Of 218 enrolled patients, 72.48% received 4884 aerosols with 30.91 ± 27.15 (95%CI: 26.6-35.1) aerosols per patient over 1108 patient days. Approximately 62.7% during IMV, 30.2% during NIV, 2.3% in spontaneously breathing patients with an artificial airway during weaning, and 4.7% were given without an artificial airway after weaning or decannulation. In 59%, a single drug was used, and bronchodilators were the most frequent. The jet nebulizer was the most common, followed by the ultrasonic and vibrating mesh aerosol generator. The ventilator setting was changed in only 6.6% of the aerosol sessions with IMV and none with NIV. CONCLUSION: Aerosol therapy is frequently used with a wide variation in practices; bronchodilators are the most commonly used drugs, and jet nebulizers are the most widely used.

5.
World Neurosurg ; 187: e673-e682, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38685347

RESUMO

OBJECTIVE: Reports on the management and survival of children with myelomeningocele defects in Bangladesh are limited. This study describes the characteristics and outcomes of these children, focusing on the timing of surgical repair and factors affecting survival. METHODS: We enrolled patients with myelomeningoceles in a case-control study on arsenic exposure and spina bifida in Bangladesh. Cases were subsequently followed at regular intervals to assess survival. Demographic, clinical, and surgical characteristics were reviewed. Univariate tests identified factors affecting survival. RESULTS: Between 2016 and 2022, we enrolled 272 patients with myelomeningocele. Postnatal surgical repair was performed in 63% of cases. However, surgery within 5 days after birth was infrequent (<10%) due to delayed presentation, and there was a high rate (29%) of preoperative deaths. Surgical repair significantly improved patient survival (P < 0.0001). Older age at time of surgery was also associated with improved survival rates, which most likely represents that those who survived to older ages prior to surgery accommodated better with their lesions. Patients who presented with ruptured lesions had lower survival rates. CONCLUSIONS: Timely neurosurgical repair of myelomeningoceles in Bangladesh is hindered by late patient presentation, resulting in a high preoperative patient death rate. Neurosurgical intervention remains a significant predictor of survival. Increased access to neurosurgical care and education of families and non-neurosurgical providers on the need for timely surgical intervention are important for improving the survival of infants with myelomeningoceles.


Assuntos
Meningomielocele , Procedimentos Neurocirúrgicos , Humanos , Bangladesh/epidemiologia , Meningomielocele/cirurgia , Masculino , Feminino , Procedimentos Neurocirúrgicos/métodos , Lactente , Estudos de Casos e Controles , Recém-Nascido , Pré-Escolar , Tempo para o Tratamento , Criança , Resultado do Tratamento , Taxa de Sobrevida
6.
Chem Pharm Bull (Tokyo) ; 72(5): 454-470, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38644216

RESUMO

This study investigates the efficacy of modified Albizia procera gum as a release-retardant polymer in Diltiazem hydrochloride (DIL) matrix tablets. Carboxymethylated Albizia procera gum (CAP) and ionically crosslinked carboxymethylated Albizia procera gum (Ca-CAP) were utilized, with Ca-CAP synthesized via crosslinking CAP with calcium ions (Ca2+) using calcium chloride (CaCl2). Fourier Transform (FT) IR analysis affirmed polymer compatibility, while differential scanning calorimetry (DSC) and X-ray diffraction (XRD) assessed thermal behavior and crystallinity, respectively. Zeta potential analysis explored surface charge and electrostatic interactions, while rheology examined flow and viscoelastic properties. Swelling and erosion kinetics provided insights into water penetration and stability. CAP's carboxymethyl groups (-CH2-COO-) heightened divalent cation reactivity, and crosslinking with CaCl2 produced Ca-CAP through -CH2-COO- and Ca2+ interactions. Structural similarities between the polymers were revealed by FTIR, with slight differences. DSC indicated modified thermal behavior in Ca-CAP, while Zeta potential analysis showcased negative charges, with Ca-CAP exhibiting lower negativity. XRD highlighted increased crystallinity in Ca-CAP due to calcium crosslinking. Minimal impact on RBC properties was observed with both polymers compared to the positive control as water for injection (WFI). Ca-CAP exhibited improved viscosity, strength, controlled swelling, and erosion, allowing prolonged drug release compared to CAP. Stability studies confirmed consistent six-month drug release, emphasizing Ca-CAP's potential as a stable, sustained drug delivery system over CAP. Robustness and accelerated stability tests supported these findings, underscoring the promise of Ca-CAP in controlled drug release applications.


Assuntos
Diltiazem , Gomas Vegetais , Comprimidos , Diltiazem/química , Gomas Vegetais/química , Comprimidos/química , Albizzia/química , Liberação Controlada de Fármacos , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/síntese química
7.
Res Sq ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38464105

RESUMO

Background: Spina bifida, a developmental malformation of the spinal cord, is associated with high rates of mortality and disability. Although folic acid-based preventive strategies have been successful in reducing rates of spina bifida, some areas continue to be at higher risk because of chemical exposures. Bangladesh has high arsenic exposures through contaminated drinking water and high rates of spina bifida. Methods: We conducted a hospital-based case-control study at the National Institute of Neurosciences & Hospital (NINS&H) in Dhaka, Bangladesh, between December 2016 and December 2022. Cases were infants under age one year with spina bifida and further classified using data from observations by neurosurgeons and available imaging. Controls were drawn from children who presented to NINS&H or Dhaka Shishu Hospital (DSH) during the same study period. Mothers reported folic acid use during pregnancy, and we assessed folate status with serum assays. Arsenic exposure was estimated in drinking water using graphite furnace atomic absorption spectrophotometry (GF-AAS) and in toenails using inductively coupled plasma mass spectrometry (ICP-MS). Results: We evaluated data from 294 cases of spina bifida and 163 controls. We did not find a main effect of mother's arsenic exposure on spina bifida risk. However, in stratified analyses, folic acid use was associated with lower odds of spina bifida (adjusted odds ratio [OR]: 0.50, 95% confidence interval [CI]: 0.25-1.00, p = 0.05) among women with toenail arsenic concentrations below the median, and no association was seen among mothers with toenail arsenic concentrations higher than median (adjusted OR: 1.09, 95% CI: 0.52-2.29, p = 0.82). Conclusions: Mother's arsenic exposure modified the protective association of folic acid with spina bifida. Increased surveillance and additional preventive strategies, such as folic acid fortification and reduction of arsenic, are needed in areas of high arsenic exposure.

8.
Birth Defects Res ; 116(3): e2331, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38526198

RESUMO

BACKGROUND: Human studies of genetic risk factors for neural tube defects, severe birth defects associated with long-term health consequences in surviving children, have predominantly been restricted to a subset of candidate genes in specific biological pathways including folate metabolism. METHODS: In this study, we investigated the association of genetic variants spanning the genome with risk of spina bifida (i.e., myelomeningocele and meningocele) in a subset of families enrolled from December 2016 through December 2022 in a case-control study in Bangladesh, a population often underrepresented in genetic studies. Saliva DNA samples were analyzed using the Illumina Global Screening Array. We performed genetic association analyses to compare allele frequencies between 112 case and 121 control children, 272 mothers, and 128 trios. RESULTS: In the transmission disequilibrium test analyses with trios only, we identified three novel exonic spina bifida risk loci, including rs140199800 (SULT1C2, p = 1.9 × 10-7), rs45580033 (ASB2, p = 4.2 × 10-10), and rs75426652 (LHPP, p = 7.2 × 10-14), after adjusting for multiple hypothesis testing. Association analyses comparing cases and controls, as well as models that included their mothers, did not identify genome-wide significant variants. CONCLUSIONS: This study identified three novel single nucleotide polymorphisms involved in biological pathways not previously associated with neural tube defects. The study warrants replication in larger groups to validate findings and to inform targeted prevention strategies.


Assuntos
Meningocele , Defeitos do Tubo Neural , Disrafismo Espinal , Criança , Humanos , Estudos de Casos e Controles , Bangladesh , Disrafismo Espinal/genética
9.
Cancer Res Commun ; 3(9): 1875-1887, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37772992

RESUMO

Histopathology has remained a cornerstone for biomedical tissue assessment for over a century, with a resource-intensive workflow involving biopsy or excision, gross examination, sampling, tissue processing to snap frozen or formalin-fixed paraffin-embedded blocks, sectioning, staining, optical imaging, and microscopic assessment. Emerging chemical imaging approaches, including stimulated Raman scattering (SRS) microscopy, can directly measure inherent molecular composition in tissue (thereby dispensing with the need for tissue processing, sectioning, and using dyes) and can use artificial intelligence (AI) algorithms to provide high-quality images. Here we show the integration of SRS microscopy in a pathology workflow to rapidly record chemical information from minimally processed fresh-frozen prostate tissue. Instead of using thin sections, we record data from intact thick tissues and use optical sectioning to generate images from multiple planes. We use a deep learning­based processing pipeline to generate virtual hematoxylin and eosin images. Next, we extend the computational method to generate archival-quality images in minutes, which are equivalent to those obtained from hours/days-long formalin-fixed, paraffin-embedded processing. We assessed the quality of images from the perspective of enabling pathologists to make decisions, demonstrating that the virtual stained image quality was diagnostically useful and the interpathologist agreement on prostate cancer grade was not impacted. Finally, because this method does not wash away lipids and small molecules, we assessed the utility of lipid chemical composition in determining grade. Together, the combination of chemical imaging and AI provides novel capabilities for rapid assessments in pathology by reducing the complexity and burden of current workflows. SIGNIFICANCE: Archival-quality (formalin-fixed paraffin-embedded), thin-section diagnostic images are obtained from thick-cut, fresh-frozen prostate tissues without dyes or stains to expedite cancer histopathology by combining SRS microscopy and machine learning.

10.
J Biomol Struct Dyn ; : 1-15, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37551031

RESUMO

A series of chrysin derivatives were designed, synthesized, and evaluated for their antibacterial activity against four different bacterial strains. We have synthesized new propyl-substituted and butyl-substituted chrysin-piperazine derivatives, which show marvellous inhibition against E. coli and S. aureus. The free hydroxyl group at the C-5 position of chrysin improved therapeutic efficacy in vivo and was a beneficial formulation for chemotherapy. All synthesized compounds were confirmed by various spectroscopic techniques such as IR, NMR, HPLC, and mass spectrometry. The compounds exhibited moderate to good inhibition, and their structure-activity relationship (SAR) has also been illustrated. Among the synthesised compounds, compounds 4 and 10 were the most active against S. pyogenes and E. coli, with 12.5 g/mL MICs; additionally, compound 12 exhibits significant activity on both the S. aureus and E. coli stains. Based on the promising activity profile and docking score of compound 12, it was selected for 100 ns MD simulation and post-dynamic binding free energy analysis within the active sites of S. aureus TyrRS (PDB ID: 1JIJ) and E. coli DNA GyrB (PDB ID: 6YD9) to investigate the stability of molecular contacts and to establish how the newly synthesized inhibitors fit together in the most stable conformations.Communicated by Ramaswamy H. Sarma.

11.
Anal Chem ; 95(30): 11365-11374, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37458316

RESUMO

Infrared (IR) spectroscopic imaging is potentially useful for digital histopathology as it provides spatially resolved molecular absorption spectra, which can subsequently yield useful information by powerful artificial intelligence methods. A typical analysis pipeline in using IR imaging data for chemical pathology often involves iterative processes of segmentation, evaluation, and analysis that necessitate rapid data exploration. Here, we present a fast, reliable, and intuitive method based on a phasor representation of spectra and discuss its unique applicability for IR imaging data. We simulate different features extant in IR spectra and discuss their influence on the phasor waveforms; similarly, we undertake IR image analysis in the transform space to understand spectral similarity and variance. We demonstrate the potential of phasor analysis for biomedical tissue imaging using a variety of samples, using fresh frozen surgical prostate resections and formalin-fixed paraffin-embedded breast cancer tissue microarray samples as model systems that span common histopathology practice. To demonstrate further generalizability of this approach, we apply the method to data from different experimental conditions─including standard (5.5 µm × 5.5 µm pixel size) and high-definition (1.1 µm × 1.1 µm pixel size) Fourier transform IR (FTIR) spectroscopic imaging using transmission and transflection modes. Quantitative segmentation results from our approach are compared to previous studies, showing good agreement and quick visualization. The presented method is rapid, easy to use, and highly capable of deciphering compositional differences, presenting a convenient tool for exploratory analysis of IR imaging data.


Assuntos
Inteligência Artificial , Neoplasias da Mama , Humanos , Feminino , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Diagnóstico por Imagem , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Espectrofotometria Infravermelho
12.
Infect Prev Pract ; 5(2): 100275, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36915471

RESUMO

Background: Trend analysis of bacteraemias caused by multi-drug resistant (MDR) and extensively drug resistant (XDR) bacteria helps to assess efficacy of infection prevention and control (IPC) practices. Data on the trends of MDR and XDR bacteraemias are lacking from cancer patients in India. Aims: To report antibiotic resistance rates over time in bacteraemias and to assess the effect of IPC practices where patient isolation facilities were limited on the rates and trends of MDR and XDR bacteraemias from a cancer centre in eastern India. Methods: A retrospective observational study was conducted in a specialist cancer hospital in India from 2011 to 2021. The study included both patients with haematological and solid organ malignancy. Data on blood cultures and surveillance culture samples were analysed. Blood cultures were processed using BACT/ALERT® (bioMérieux, Marcy-l'Étoile, France) and the identification and antibiotic susceptibilities of bacteria were performed using VITEK® 2 (bioMérieux, Marcy-l'Étoile, France). Surveillance cultures for MDR/XDR bacteria were performed on a subset of patients and processed based on a modified method described previously. Findings: 3rd-generation cephalosporin-resistant Gram negative bacilli were the commonest cause of MDR bacteraemia (57.6%) followed by carbapenem resistant organisms (CRO) (35.7%). Bacteraemias caused by vancomycin-resistant enterococci (VRE), meticillin-resistant Staphylococcus aureus (MRSA) and colistin-resistant Gram negative bacilli were responsible for 1.3%, 2.3% and 3.0% of laboratory confirmed bloodstream infections (BSI) respectively. The ranges of the rates of MDR/XDR BSI per 1000 in-patients during the study period were: MRSA (1-1.18), VRE (0-0.88), 3rd generation cephalosporin-resistant Gram negative bacilli (10.10-20.32), CRO (5.05-13.07) and colistin-resistant Gram negative bacilli (E. coli, Klebsiella, Pseudomonas aeruginosa, Acinetobacter spp (0-1.3). Surveillance cultures collected from a subset of patients showed ranges of MRSA detection in 0-2.11%, VRE in 1.67%-7.49%, 3rd generation cephalosporin-resistant Gram negative bacilli in 55%-89.91% and carbapenem resistant Gram negative bacilli in 18.33%-31.11% of patients. Conclusion: This is one of few studies providing trend data for MDR/XDR bacteraemia rates among cancer patients in India over a decade. In a high prevalence setting it was possible to keep the rates of MDR/XDR bacteraemia controlled with IPC strategies and without adequate isolation facilities. The results are of potential interest to policy makers, IPC specialists and clinicians.

13.
Inorg Chem ; 61(33): 12931-12947, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35939766

RESUMO

The factors that control the rate and selectivity of 4e-/4H+ O2 reduction are important for efficient energy transformation as well as for understanding the terminal step of respiration in aerobic organisms. Inspired by the design of naturally occurring enzymes which are efficient catalysts for O2 and H2O2 reduction, several artificial systems have been generated where different second-sphere residues have been installed to enhance the rate and efficiency of the 4e-/4H+ O2 reduction. These include hydrogen-bonding residues like amines, carboxylates, ethers, amides, phenols, etc. In some cases, improvements in the catalysis were recorded, whereas in some cases improvements were marginal or nonexistent. In this work, we use an iron porphyrin complex with pendant 1,10-phenanthroline residues which show a pH-dependent variation of the rate of the electrochemical O2 reduction reaction (ORR) over 2 orders of magnitude. In-situ surface-enhanced resonance Raman spectroscopy reveals the presence of different intermediates at different pH's reflecting different rate-determining steps at different pH's. These data in conjunction with density functional theory calculations reveal that when the distal 1,10-phenanthroline is neutral it acts as a hydrogen-bond acceptor which stabilizes H2O (product) binding to the active FeII state and retards the reaction. However, when the 1,10-phenanthroline is protonated, it acts as a hydrogen-bond donor which enhances O2 reduction by stabilizing FeIII-O2.- and FeIII-OOH intermediates and activating the O-O bond for cleavage. On the basis of these data, general guidelines for controlling the different possible rate-determining steps in the complex multistep 4e-/4H+ ORR are developed and a bioinspired principle-based design of an efficient electrochemical ORR is presented.


Assuntos
Ferro , Porfirinas , Hidrogênio , Peróxido de Hidrogênio , Ferro/química , Oxirredução , Oxigênio/química
14.
J Anaesthesiol Clin Pharmacol ; 38(1): 61-65, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35706623

RESUMO

Background and Aims: Objective prediction of postoperative morbidity and mortality can help clinicians for appropriate resource allocation and counseling of patients and their kin. Among different scoring systems, "Portsmouth- Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity" (P-POSSUM) includes both preoperative and intraoperative parameters for postoperative risk prediction. The aim of this study was to investigate the validity of morbidity prediction by P-POSSUM in patients requiring intensive care after undergoing major surgeries for gastrointestinal and gynecological malignancies. Material and Methods: All adult patients (>18 years) undergoing gastrointestinal and gynecological cancer surgeries who were shifted to intensive care unit (ICU) or high dependency unit (HDU) for postoperative care were included and P-POSSUM was measured. Postoperative complications were graded as per Clavien-Dindo (CD) grading and have been compared with predicted complications as per P-POSSUM. Results: 143 patients were included in the study and the median P-POSSUM score was 35. The mean predicted morbidity was 55.28% (SD 25.54%) and the observed complications were 45.45%, which shows P- POSSUM has over predicted morbidity. At P-POSSUM values 60 and above, the incidence of major complications was 22.22%, compared to 6.25% for the rest (Odds ratio 4.286). Conclusion: P-POSSUM is not a reliable predictor of postoperative morbidity for patients undergoing major gynecological and gastrointestinal surgeries for cancer in our institution. But there is a significant incidence of major complications with P- POSSUM morbidity prediction score 60 or higher leading to the need for more stringent assessment and monitoring in that subgroup.

15.
Childs Nerv Syst ; 38(8): 1497-1504, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35588333

RESUMO

PURPOSE: To describe the design, implementation, and adoption of a simplified electronic medical record (EMR) and its use in documenting pediatric central nervous system (CNS) tumors at a tertiary care referral hospital in South-East Asia. METHODS: A novel EMR, cataloguing pediatric CNS tumors was used to collect data from August 2017 to March 2020 at National Institute of Neurosciences and Hospital (NINS&H) in Dhaka, Bangladesh. RESULTS: Two hundred forty-nine pediatric patients with a CNS tumor were admitted to NINS&H. Fifty-eight percent of patients were male, and the median age was 8 years. A total of 188/249 patients (76%) underwent surgery during their index admission. Radiographic locations were known for 212/249 (85%) of cases; the most common radiographic locations were infratentorial (81/212; 38%), suprasellar (45/212; 21%), and supratentorial (29/212; 14%). A histopathological classification was reported on 156/249 (63%) of patients' cytology. The most common infratentorial pathologies were medulloblastoma (22/47; 47%) and pilocytic astrocytoma (14/47; 30%). The median time between admission and surgery was 36 days, while the median post-operation stay was 19.5 days. CONCLUSIONS: The feasibility of a basic EMR platform for a busy pediatric neurosurgery department in a lower-middle income country is demonstrated, and preliminary clinical data is reviewed. A wide variety of pediatric CNS tumors were observed, spanning the spectrum of anatomic locations and histopathologic subtypes. Surgical intervention was performed for the majority of patients. Barriers to care include limited molecular diagnostics and unavailable data on adjuvant therapy. Future targets include improvement of clinical documentation in the pre-operative and post-operative period.


Assuntos
Astrocitoma , Neoplasias do Sistema Nervoso Central , Neoplasias Cerebelares , Bangladesh , Neoplasias do Sistema Nervoso Central/diagnóstico por imagem , Neoplasias do Sistema Nervoso Central/cirurgia , Criança , Registros Eletrônicos de Saúde , Feminino , Humanos , Masculino
16.
Development ; 149(6)2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35299238

RESUMO

The maintenance of epithelial architecture necessitates tight regulation of cell size and shape. However, mechanisms underlying epithelial cell size regulation remain poorly understood. We show that the interaction of Myosin Vb with Rab11 prevents the accumulation of apically derived endosomes to maintain cell-size, whereas that with Rab10 regulates vesicular transport from the trans-Golgi. These interactions are required for the fine-tuning of the epithelial cell morphology during zebrafish development. Furthermore, the compensatory cell growth upon cell-proliferation inhibition involves a preferential expansion of the apical domain, leading to flatter epithelial cells, an efficient strategy to cover the surface with fewer cells. This apical domain growth requires post-trans-Golgi transport mediated by the Rab10-interacting Myosin Vb isoform, downstream of the mTOR-Fatty Acid Synthase (FASN) axis. Changes in trans-Golgi morphology indicate that the Golgi synchronizes mTOR-FASN-regulated biosynthetic input and Myosin Vb-Rab10 dependent output. Our study unravels the mechanism of polarized growth in epithelial cells and delineates functions of Myosin Vb isoforms in cell size regulation during development.


Assuntos
Miosina Tipo V , Animais , Células Epiteliais/metabolismo , Miosina Tipo V/metabolismo , Isoformas de Proteínas/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Peixe-Zebra/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo
17.
Environ Health ; 21(1): 13, 2022 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-35031057

RESUMO

BACKGROUND: Arsenic exposure has been associated with gestational diabetes mellitus. However, the extent to which arsenic exposure during pregnancy is associated with postpartum glucose intolerance is unknown. METHODS: We studied 323 women in Bangladesh. We assessed arsenic exposure in early pregnancy via toenail and water samples. We measured fasting glucose and insulin in serum at a mean (SD) of 4.0 (3.5) weeks post-delivery. We ran covariate-adjusted, linear regression models to examine associations of arsenic concentrations with HOMA-IR, a marker of insulin resistance, and HOMA-ß, a marker of beta cell function. RESULTS: Median (IQR) arsenic concentration was 0.45 (0.67) µg/g in toenails and 2.0 (6.5) µg/L in drinking water. Arsenic concentrations during pregnancy were not associated with insulin resistance or beta cell function postpartum. HOMA-IR was 0.07% (- 3.13, 3.37) higher and HOMA-ß was 0.96% (- 3.83, 1.99) lower per IQR increment in toenail arsenic, but effect estimates were small and confidence intervals crossed the null. CONCLUSIONS: Although arsenic exposure during pregnancy has been consistently associated with gestational diabetes mellitus, we found no clear evidence for an adverse effect on postpartum insulin resistance or beta cell function.


Assuntos
Arsênio , Diabetes Gestacional , Arsênio/análise , Bangladesh/epidemiologia , Glicemia , Diabetes Gestacional/induzido quimicamente , Diabetes Gestacional/epidemiologia , Feminino , Glucose , Humanos , Período Pós-Parto , Gravidez
18.
J Phys Chem B ; 125(33): 9507-9516, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34433279

RESUMO

Vibrationally resonant sum-frequency generation (VR SFG) microscopy is an advanced imaging technique that can map out the intensity contrast of infrared and Raman active vibrational modes with micron to submicron lateral resolution. To broaden its applications and to obtain a molecular level of understanding, further technical advancement is needed to enable high-speed measurements of VR SFG microspectra at every pixel. In this study, we demonstrate a new VR SFG hyperspectral imaging platform combined with an ultrafast laser system operated at a repetition rate of 80 MHz. The multiplex configuration with broadband mid-infrared pulses makes it possible to measure a single microspectrum of CH/CH2 stretching modes in biological samples, such as starch granules and type I collagen tissue, with an exposure time of hundreds of milliseconds. Switching from the homodyne- to heterodyne-detected VR SFG hyperspectral imaging can be achieved by inserting a pair of optics into the beam path for local oscillator generation and delay time adjustment, which enables self-phase-stabilized spectral interferometry. We investigate the relationship between phase images of several different C-H modes and the relative orientation of collagen triple-helix in fibril bundles. The results show that the new multiplex VR SFG microscope operated at a high repetition rate is a powerful approach to probe the structural features and spatial arrangements of biological systems in detail.


Assuntos
Microscopia , Vibração , Espectrofotometria Infravermelho
19.
Environ Int ; 157: 106800, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34358915

RESUMO

BACKGROUND: Neural tube defects are a pressing public health concern despite advances in prevention from folic acid-based strategies. Numerous chemicals, in particular arsenic, have been associated with neural tube defects in animal models and could influence risk in humans. OBJECTIVES: We investigated the relationship between parental exposure to arsenic and 17 metals and risk of neural tube defects (myelomeningocele and meningocele) in a case control study in Bangladesh. METHODS: Exposure assessment included analysis of maternal and paternal toenail samples using inductively coupled plasma mass spectrometry (ICP-MS). A total of 278 participants (155 cases and 123 controls) with data collected from 2016 to 2020 were included in the analysis. RESULTS: In the paternal models, a one-unit increase in the natural logarithm of paternal toenail arsenic was associated with a 74% (odds ratio: 1.74, 95% confidence interval: 1.26-2.42) greater odds of having a child with spina bifida, after adjusting for relevant covariates. Additionally, paternal exposure to aluminum, cobalt, chromium, iron, selenium, and vanadium was associated with increased odds of having a child with spina bifida in the adjusted models. In the maternal models, a one-unit increase in the natural logarithm of maternal toenail selenium and zinc levels was related to a 382% greater (odds ratio: 4.82, 95% confidence interval: 1.32-17.60) and 89% lower (odds ratio: 0.11, 95% confidence interval: 0.03-0.42) odds of having a child with spina bifida in the adjusted models, respectively. Results did not suggest an interaction between parental toenail metals and maternal serum folate. DISCUSSION: Parental toenail levels of numerous metals were associated with increased risk of spina bifida in Bangladeshi infants. Paternal arsenic exposure was positively associated with neural tube defects in children and is of particular concern given the widespread arsenic poisoning of groundwater resources in Bangladesh and the lack of nutritional interventions aimed to mitigate paternal arsenic exposure. The findings add to the growing body of literature of the impact of metals, especially paternal environmental factors, on child health.


Assuntos
Arsênio , Disrafismo Espinal , Bangladesh/epidemiologia , Estudos de Casos e Controles , Humanos , Masculino , Fatores de Risco , Disrafismo Espinal/epidemiologia , Disrafismo Espinal/etiologia
20.
J Anaesthesiol Clin Pharmacol ; 37(2): 284-289, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34349381

RESUMO

India came under the grip of the coronavirus disease-2019 (COVID-19) pandemic and is now seeing rising graph. Cancer patients are specially in the high-risk group because of their immunocompromised status on one hand and progressive disease on the other hand. Hence, cancer care facility needs to prepare a clear strategy to manage their space, staff and supplies so that optimum patient care can be continued in the face of COVID-19 pandemic. In addition, infection prevention measures need to be robust to reduce in-hospital transmission. The working area of anesthesia and Critical Care is spread over the whole hospital such as operating room, ICU, isolation area, out-patient dept (OPD) area, various diagnostic areas and in-patient dept (IPD) to attend code blue calls. In this article, we describe the preparedness and initial response measures of the anesthesia and Critical Care department of a stand-alone tertiary level cancer care centre in eastern part of India. These include engineering controls such as identification and preparation of an isolation operating room, administrative measures such as modification of workflow, introduction and adequate supply of personal protective equipment for staff and formulation of clinical guidelines for anesthetic management. These containment measures are necessary to continue care of cancer patients, optimize the quality of care provided to COVID-19 positive cancer patients and to reduce the risk of viral transmission to other patients or healthcare providers.

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