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Background: Apart from the well-established skeletal effects, vitamin D has been explored as a secretagogue influencing various adipokines, including adiponectin and irisin. Recent evidence suggests that specific forms of 25-Hydroxyvitamin D (25(OHD), such as free and bioavailable 25(OH)D, may provide more accurate measurements of vitamin D status. The relationship between vitamin D status and serum irisin and adiponectin concentrations remains largely unexplored, particularly during pregnancy. Methods: We analyzed data from 67 healthy maternal-neonatal pairs from Northern Greece at birth. Biochemical and hormonal tests were conducted on each maternal-neonatal pair. The vitamin D forms were estimated using validated mathematical models. Subsequently, regression analyses were conducted to determine the association between the vitamin D forms and adipokine levels. Results: Bioavailable maternal 25(OH)D was inversely associated with neonatal irisin concentrations [ß=-73.46 (-140.573 to -6.341), p=0.034]. No other associations were observed between maternal vitamin D status and neonatal adipokine concentrations. Conclusion: In conclusion, maternal bioavailable vitamin D concentrations are inversely associated with neonatal serum irisin concentrations, warranting further studies to evaluate the underlying mechanisms for this finding.
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Adiponectina , Fibronectinas , Vitamina D , Humanos , Fibronectinas/sangue , Feminino , Vitamina D/sangue , Vitamina D/análogos & derivados , Adiponectina/sangue , Grécia , Gravidez , Recém-Nascido , Adulto , MasculinoRESUMO
BACKGROUND: Despite the decline of the COVID-19 pandemic, there continues to be a persistent requirement for reliable testing methods that can be adapted to future outbreaks and areas with limited resources. While the standard approach of using reverse transcription-polymerase chain reaction (RT-PCR) with Taq polymerase is effective, it faces challenges such as limited access to high-quality enzymes and the presence of bacterial DNA contamination in commercial kits, which can impact the accuracy of test results. METHODS: This study investigates the production of recombinant Taq polymerase in yeast cells and assesses its crude lysate in a multiplex RT-PCR assay for detecting the SARS-CoV-2 RNA-dependent RNA polymerase (RdRP) and N genes, with human Ribonuclease P serving as an internal control. RESULTS: The unpurified yeast Taq polymerase demonstrates sensitivity comparable to commercially purified bacterial Taq polymerase and unpurified bacterial counterparts in detecting the RdRP and N genes. It exhibits the highest specificity, with 100% accuracy, for the N gene. The specificity for the RdRP gene closely aligns with that of commercially purified bacterial Taq polymerase and unpurified bacterial Taq polymerase. CONCLUSIONS: The use of unpurified recombinant yeast Taq polymerase shows promise as a cost-effective approach for conducting in-house COVID-19 RT-PCR testing. By eliminating the need for chromatography purification steps, the production of RT-PCR kits can be streamlined, potentially improving accessibility and scalability, especially in resource-limited settings and future pandemics.
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Sufficient vitamin D status is crucial for successful pregnancy and fetal development. The assessment of 25-hydroxyvitamin D (25(OH)D) concentrations is commonly used to evaluate vitamin D status. Our objective was to examine the interrelated biodynamics of maternal and neonatal total, free and bioavailable 25(OH)D in maternal-neonatal dyads at birth and their associations with homeostasis and neonatal birth anthropometry. We analysed a cohort of seventy full-term mother-child pairs. We found positive associations between all neonatal measures of vitamin D status. Maternal forms exhibited a similar pattern of association, except for the bioavailable maternal form. In multivariate analysis, both total and free maternal 25(OH)D concentrations were correlated with all neonatal forms (neonatal total 25(OH)D: 1·29 (95 % CI, 1·12, 1·46) for maternal total 25(OH)D, 10·89 (8·16, 13·63) for maternal free 25(OH)D), (neonatal free 25(OH)D: 0·15 for maternal total 25(OH)D, 1·28 (95 % CI, 0·89, 1·68) for maternal free 25(OH)D) and (0·13 (95 % CI, 0·10, 0·16), 1·06 (95 % CI, 0·68, 1·43) for maternal free 25(OH)D), respectively, with the exclusion of the bioavailable maternal form. We observed no significant interactions within or between groups regarding maternal and neonatal vitamin D parameters and maternal calcium and parathyroid hormone concentrations, and neonatal birth anthropometry. Our study indicates that bioavailable maternal and neonatal 25(OH)D have no significant effects on vitamin D equilibrium, Ca homeostasis and neonatal anthropometry at birth. However, we observed an interaction between maternal and neonatal total and free 25(OH)D concentrations at the maternal-neonatal interface, with no associations observed with other calciotropic or anthropometric outcomes.
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Cálcio , Deficiência de Vitamina D , Vitamina D/análogos & derivados , Gravidez , Recém-Nascido , Feminino , Humanos , Calcifediol , Vitaminas , Cálcio da Dieta , Antropometria , Relações Mãe-FilhoRESUMO
Background: Previous studies have assessed the impact of age and body mass index (BMI) on surgery outcomes separately. This retrospective cohort study aimed to investigate the combined effect of age and BMI on postoperative mortality and morbidity in patients undergoing laparoscopic cholecystectomy. Methods: Data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database for laparoscopic cholecystectomy patients between 2008 and 2020 were analyzed. Patient demographics, functional status, admission sources, preoperative risk factors, laboratory data, perioperative variables, and 30-day postoperative outcomes were included in the dataset. Logistic regression was used to determine the association of age, BMI, and age/BMI with mortality and morbidity. Patients were stratified into different subcategories based on their age and BMI, and the age/BMI score was calculated. The chi-square test, independent sample t-test, and ANOVA were used as appropriate for each category. Results: The study included 435,052 laparoscopic cholecystectomy patients. Logistic regression analysis revealed that a higher age/BMI score was associated with an increased risk of mortality (adj OR 13.13 95% CI, 9.19-18.77, p < 0.0001) and composite morbidity (adj OR 2.57, 95% CI 2.23-2.95, p < 0.0001). Conclusion: Older age, especially accompanied by a low BMI, appears to increase the post-operative mortality and morbidity risks in laparoscopic cholecystectomy patients, while paradoxically, a higher BMI seems to be protective. Our hypothesis is that a lower BMI, perhaps secondary to malnutrition, can carry a greater risk of surgery complications for the elderly. Age/BMI is strongly and positively associated with mortality and morbidity and could be used as a new scoring system for predicting outcomes in patients undergoing surgery. Nevertheless, laparoscopic cholecystectomy remains a very safe procedure with relatively low complication rates.
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COVID-19 pandemic has increased social media engagement globally. This study examined the correlation between social media use and physical/mental health among university students, considering gender and academic year. Out of 146 responses, 119 were analyzed after excluding participants with pre-existing psychological conditions. Results showed a significant correlation between social media use and mental health for all participants (correlation coefficient = 0.30, p < 0.001), indicating a negative impact on mental health with increased use. Gender-specific analysis revealed a non-significant correlation among males (p = 0.21), while females exhibited a significant correlation (correlation coefficient = 0.32, p = 0.01), suggesting an adverse effect on their mental health. Regarding physical health, females displayed an even higher correlation (correlation coefficient = 0.40, p < 0.001), highlighting the negative influence of social media on their physical well-being. Conversely, no significant correlation was observed among males. Analyzing by academic year, both pre-clerkship and clerkship students showed a significant correlation between social media use and mental health (correlation coefficients of 0.26, p = 0.01, and 0.42, p = 0.03, respectively). Similarly, a significant correlation was found between social media use and physical health among pre-clerkship students (correlation coefficient = 0.34, p = 0.001), but not among clerkship students. In conclusion, this study provides evidence of the adverse impact of social media use on physical and mental health among university students, particularly among females and across different academic years. These findings underscore the importance of promoting healthy social media habits and raising awareness about the potential negative effects on well-being.
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COVID-19 , Mídias Sociais , Estudantes de Medicina , Feminino , Masculino , Humanos , Saúde Mental , Pandemias , COVID-19/epidemiologiaRESUMO
Accumulating evidence supports the potential protective effects of vitamin D against chronic diseases such as Alzheimer's disease, autoimmune diseases, cancers, cardiovascular disease (ischaemic heart disease and stroke), type 2 diabetes, hypertension, chronic kidney disease, stroke, and infectious diseases such as acute respiratory tract diseases, COVID-19, influenza, and pneumonia, as well as adverse pregnancy outcomes. The respective evidence is based on ecological and observational studies, randomized controlled trials, mechanistic studies, and Mendelian randomization studies. However, randomized controlled trials on vitamin D supplementation have largely failed to show benefits, probably due to poor design and analysis. In this work, we aim to use the best available evidence on the potential beneficial effects of vitamin D to estimate the expected reduction in incidence and mortality rates of vitamin D-related diseases in the Kingdom of Saudi Arabia and the United Arab Emirates if minimum serum 25(OH)D concentrations were to be raised to 30 ng/mL. Estimated reductions by 25% for myocardial infarction incidence, 35% for stroke incidence, 20 to 35% for cardiovascular disease mortality, and 35% for cancer mortality rates depicted a promising potential for raising serum 25(OH)D. Methods to increase serum 25(OH)D concentrations at the population level could include food fortification with vitamin D3, vitamin D supplementation, improved dietary vitamin D intake, and sensible sun exposure.
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Vitamin D plays a crucial role in modulating the innate immune response by interacting with its intracellular receptor, VDR. In this review, we address vitamin D/VDR signaling and how it contributes to the regulation of intestinal and respiratory microbiota. We additionally review some components of the innate immune system, such as the barrier function of the pulmonary and intestinal epithelial membranes and secretion of mucus, with their respective modulation by vitamin D. We also explore the mechanisms by which this vitamin D/VDR signaling mounts an antimicrobial response through the transduction of microbial signals and the production of antimicrobial peptides that constitute one of the body's first lines of defense against pathogens. Additionally, we highlight the role of vitamin D in clinical diseases, namely inflammatory bowel disease and acute respiratory distress syndrome, where excessive inflammatory responses and dysbiosis are hallmarks. Increasing evidence suggests that vitamin D supplementation may have potentially beneficial effects on those diseases.
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Doenças Inflamatórias Intestinais , Vitamina D , Humanos , Vitamina D/fisiologia , Intestinos , Imunidade Inata , Vitaminas , Sistema Respiratório , Receptores de CalcitriolRESUMO
Background and Objectives: Visceral obesity is associated with chronic low-grade inflammation that predisposes to metabolic syndrome. Indeed, infiltration of adipose tissue with immune-inflammatory cells, including 'classical' inflammatory M1 and anti-inflammatory 'alternative' M2 macrophages, causes the release of a variety of bioactive molecules, resulting in the metabolic complications of obesity. This study examined the relative expression of macrophage phenotypic surface markers, cholesterol efflux proteins, scavenger receptors, and adenosine receptors in human circulating peripheral blood mononuclear cells (PBMCs), isolated from patients with type 2 diabetes mellitus (T2DM), with the aim to phenotypically characterize and identify biomarkers for these ill-defined cells. Materials and Methodology: PBMCs were isolated from four groups of adults: Normal-weight non-diabetic, obese non-diabetic, newly diagnosed with T2DM, and T2DM on metformin. The mRNA expression levels of macrophage phenotypic surface markers (interleukin-12 (IL-12), C-X-C motif chemokine ligand 10 (CXCL10), C-C motif chemokine ligand 17 (CCL17), and C-C motif receptor 7 (CCR7)), cholesterol efflux proteins (ATP-binding cassette transporter-1 (ABCA1), ATP binding cassette subfamily G member 1 (ABCG1), and sterol 27-hydroxylase (CYP27A)), scavenger receptors (scavenger receptor-A (SR-A), C-X-C motif ligand 16 (CXCL16), and lectin-like oxidized LDL receptor-1 (LOX-1)), and adenosine receptors (adenosine A2A receptor (A2AR) and adenosine A3 receptor (A3R)) were measured using qRT-PCR. Results: In PBMCs from T2DM patients, the expression of IL-12, CCR7, ABCA1, and SR-A1 was increased, whereas the expression of CXCL10, CCL17, ABCG1,27-hydroxylase, LOX-1, A2AR and A3R was decreased. On the other hand, treatment with the antidiabetic drug, metformin, reduced the expression of IL-12 and increased the expression of 27-hydroxylase, LOX-1, CXCL16 and A2AR. Conclusions: PBMCs in the circulation of patients with T2DM express phenotypic markers that are different from those typically present in adipose tissue M1 and M2 macrophages and could be representative of metabolically activated macrophages (MMe)-like cells. Our findings suggest that metformin alters phenotypic markers of MMe-like cells in circulation.
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Diabetes Mellitus Tipo 2 , Metformina , Adulto , Humanos , Transportador 1 de Cassete de Ligação de ATP/genética , Colesterol , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Perfilação da Expressão Gênica , Interleucina-12 , Leucócitos Mononucleares , Ligantes , Metformina/metabolismo , Obesidade/metabolismo , Receptores CCR7/genética , Receptores CCR7/metabolismo , Receptores Depuradores Classe B/genética , Receptores Depuradores Classe B/metabolismo , Receptores Depuradores Classe ERESUMO
The COVID-19 pandemic necessitated an extensive testing for active SARS-CoV-2 infection. However, securing affordable diagnostic tests is a struggle for low-resource settings. We report herein the development and validation of an in-house multiplex real-time RT-PCR diagnostic test for the detection of active COVID-19 infection (ScriptTaq COVID PCR). Furthermore, we describe two methods for RNA extraction using either an in-house silica column or silica-coated magnetic beads to replace commercial RNA extraction kits. Different buffer formulations for silica column and silica-coated magnetic beads were tested and used for RNA isolation. Taq polymerase enzyme and thermostable reverse transcriptase enzyme were purified from bacterial clones. Primers/probes sequences published by the WHO and CDC were used for the qualitative detection of the RNA-dependent RNA polymerase (RdRp) and nucleocapsid (N) genes, respectively. ScriptTaq COVID PCR assay was able to detect up to 100 copies per reaction of the viral RdRP and N genes. The test demonstrated an overall agreement of 95.4%, a positive percent agreement (PPA) of 90.2%, and a negative percent agreement (NPA) of 100.0% when compared with two commercially available kits. ScriptTaq COVID PCR diagnostic test is a specific, sensitive, and low-cost alternative for low-resource settings.
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The objective of this study was to investigate the effect of age and BMI on the risk of death in patients with coronavirus disease 2019 (COVID-19). A cohort of 206 Saudi COVID-19 patients was included in this study. Data on age, BMI, hospitalization, comorbidities, and death were collected and analyzed. Descriptive, univariate, and multivariate logistic regression analyses were carried out. Out of the 206 studied patients, 28 died. Hypertension, cardiac disease, and hospital admission were predictors of death in univariate and multivariate logistic regression analysis. Moreover, age was a significant predictor of death, while increased BMI seemed to be protective at an older age. Therefore, a new score was suggested taking into consideration both factors, namely age/BMI score. Although older age was associated with death in univariate (OR, 1.09 [95% CI 1.05-1.12], p < 0.001) and multivariate analysis (OR, 1.05 [95% CI 1.02-1.09], p = 0.004), a higher age/BMI score was a stronger predictor of death than age alone, in both univariate (OR 4.42 [95% CI 2.50-7.80], p < 0.001) and multivariate analysis (OR 3.11 [95% CI 1.66-5.82], p < 0.001). Several factors appear to contribute to the risk of COVID-19 death. Interestingly, our new age/BMI score seems to carry a higher risk of death than age alone. This new score will be designated as the Hajeer score. Since this is a small cohort study, we recommend investigating this score in a larger cohort.
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COVID-19 , Humanos , SARS-CoV-2 , Projetos Piloto , Índice de Massa Corporal , Estudos de Coortes , Fatores de Risco , Hospitalização , Comorbidade , Estudos RetrospectivosRESUMO
In addition to its role in bone health, vitamin D (VitD) has been implicated in several pathological conditions. Specifically, VitD deficiency has been linked to an increased risk of dyslipidemia. Atherogenic dyslipidemia is characterized by increased low-density lipoprotein-cholesterol (LDL-C) and decreased high-density lipoprotein-cholesterol (HDL-C). In this study, we examined the association of six single nucleotide polymorphisms (SNPs) in VitD-related genes with VitD and lipid levels, in a cohort of 460 Lebanese participants free from chronic diseases. Our results showed no association of the examined SNPs with VitD concentrations. However, the presence of the minor allele in rs10741657G>A of CYP2R1 was associated with increased levels in LDL-C (ß = 4.95, p = 0.04)] and decreased levels in HDL-C (ß = −1.76, p = 0.007)]. Interestingly, rs10741657G>A interacted with gender to increase LDL-C levels in females (ß = 6.73 and p = 0.03) and decrease HDL-C levels in males HDL-C (ß = −1.09, p = 0.009). In conclusion, our results suggest that rs10741657 G>A in CYP2R1 is associated with circulating LDL-C and HDL-C levels in a Lebanese cohort. Although this association was gender-specific, where rs10741657G>A was associated with increased LDL in females and decreased HDL in males, the presence of the minor allele A was associated with increased cardiovascular risk in both genders. These findings need to be validated in a larger population. Further investigations are warranted to elucidate the molecular mechanism of VitD polymorphism and dyslipidemia.
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Recent results indicate that dysregulation of vitamin D-binding protein (VDBP) could be involved in the development of hypovitaminosis D, and it comprises a risk factor for adverse fetal, maternal and neonatal outcomes. Until recently, there was a paucity of results regarding the effect of maternal and neonatal VDBP polymorphisms on vitamin D status during pregnancy in the Mediterranean region, with a high prevalence of hypovitaminosis D. We aimed to evaluate the combined effect of maternal and neonatal VDBP polymorphisms and different maternal and neonatal 25-hydroxyvitamin D (25(OH)D) cut-offs on maternal and neonatal vitamin D profile. Blood samples were obtained from a cohort of 66 mother-child pairs at birth. Our results revealed that: (i) Maternal VDBP polymorphisms do not affect neonatal vitamin D status at birth, in any given internationally adopted maternal or neonatal cut-off for 25(OH)D concentrations; (ii) neonatal VDBP polymorphisms are not implicated in the regulation of neonatal vitamin D status at birth; (iii) comparing the distributions of maternal VDBP polymorphisms and maternal 25(OH)D concentrations, with cut-offs at birth, revealed that mothers with a CC genotype for rs2298850 and a CC genotype for rs4588 tended to demonstrate higher 25(OH)D (≥75 nmol/L) during delivery (p = 0.05 and p = 0.04, respectively), after adjustments for biofactors that affect vitamin D equilibrium, including UVB, BMI and weeks of gestation. In conclusion, this study from Southern Europe indicates that maternal and neonatal VDBP polymorphisms do not affect neonatal vitamin D status at birth, whereas mothers with CC genotype for rs2298850 and CC genotype for rs4588 demonstrate higher 25(OH)D concentrations. Future larger studies are required to establish a causative effect of these specific polymorphisms in the attainment of an adequate (≥75 nmol/L) maternal vitamin D status during pregnancy.
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Estado Nutricional , Polimorfismo Genético/genética , Deficiência de Vitamina D/genética , Proteína de Ligação a Vitamina D/genética , Vitamina D/análogos & derivados , Adulto , Estudos de Coortes , Feminino , Genótipo , Humanos , Recém-Nascido , Masculino , Fenômenos Fisiológicos da Nutrição Materna , Região do Mediterrâneo , Gravidez , Fatores de Risco , Luz Solar , Vitamina D/sangue , Deficiência de Vitamina D/sangueRESUMO
SARS-CoV-2 infects the respiratory tract and leads to the disease entity, COVID-19. Accordingly, the lungs bear the greatest pathologic burden with the major cause of death being respiratory failure. However, organs remote from the initial site of infection (e.g., kidney, heart) are not spared, particularly in severe and fatal cases. Emerging evidence indicates that an excessive inflammatory response coupled with a diminished antiviral defense is pivotal in the initiation and development of COVID-19. A common finding in autopsy specimens is the presence of thrombi in the lungs as well as remote organs, indicative of immunothrombosis. Herein, the role of SARS-CoV-2 in lung inflammation and associated sequelae are reviewed with an emphasis on immunothrombosis. In as much as vitamin D is touted as a supplement to conventional therapies of COVID-19, the impact of this vitamin at various junctures of COVID-19 pathogenesis is also addressed.
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Tratamento Farmacológico da COVID-19 , COVID-19/imunologia , Inflamação/virologia , Pneumonia/virologia , Vitamina D/uso terapêutico , Animais , COVID-19/virologia , Armadilhas Extracelulares , Humanos , Inflamação/tratamento farmacológico , Pulmão/patologia , Camundongos , Insuficiência de Múltiplos Órgãos/virologia , Pneumonia/tratamento farmacológico , Síndrome do Desconforto Respiratório/virologia , SARS-CoV-2 , Trombose/imunologia , Trombose/virologia , Vitaminas/uso terapêuticoRESUMO
The respiratory tract is the major site of infection by SARS-CoV-2, the virus causing COVID-19. The pulmonary infection can lead to acute respiratory distress syndrome (ARDS) and ultimately, death. An excessive innate immune response plays a major role in the development of ARDS in COVID-19 patients. In this scenario, activation of lung epithelia and resident macrophages by the virus results in local cytokine production and recruitment of neutrophils. Activated neutrophils extrude a web of DNA-based cytoplasmic material containing antimicrobials referred to as neutrophil extracellular traps (NETs). While NETs are a defensive strategy against invading microbes, they can also serve as a nidus for accumulation of activated platelets and coagulation factors, forming thrombi. This immunothrombosis can result in occlusion of blood vessels leading to ischemic damage. Herein we address evidence in favor of a lung-centric immunothrombosis and suggest a lung-centric therapeutic approach to the ARDS of COVID-19.
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COVID-19 , Armadilhas Extracelulares , Síndrome do Desconforto Respiratório , Humanos , Pulmão , SARS-CoV-2RESUMO
The flipped classroom has gained prominence in higher education, but little has been written about its application in the Middle East. This study aimed to assess the feasibility, acceptability, and impact of flipping biochemistry classes in comparison to the traditional didactic program. The study was conducted on first-year medical students taking biochemistry at a private University in Saudi Arabia. A series of short, pre-recorded videos were used to replace traditional lectures. The scheduled lecture time was used for problem solving and discussion sessions. To gather their evaluation of the learning approach, participants completed an online survey. To study the effect of the learning approach on exam performance, the scores of the participants were compared in questions taught using the flipped classroom versus the traditional didactic method. Participants noted that the effort needed for the course was similar regardless of the learning approach. Moreover, examination performance measured using single best answer multiple-choice questions showed no difference between the two teaching methods. However, the participants did report a significantly better perception of the flipped classroom compared to the traditional approach. Although no significant improvement in examination results was noted, the participants significantly favored the flipped classroom over traditional lectures. This study has demonstrated that the flipped classroom can be used in the teaching of the biosciences within a Middle Eastern setting, resulting in an improvement in student satisfaction and engagement in the course materials.
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Bioquímica/educação , Instrução por Computador/métodos , Currículo , Educação de Graduação em Medicina/normas , Avaliação Educacional/métodos , Aprendizagem Baseada em Problemas/métodos , Estudantes de Medicina/psicologia , Feminino , Humanos , Masculino , Percepção , Satisfação Pessoal , Arábia Saudita , UniversidadesRESUMO
INTRODUCTION: Insulin resistance in obesity and type 2 diabetes mellitus (T2DM) is associated with cardiovascular complications such as atherosclerosis. On the other hand, the reduction of apoptosis in macrophages has been linked with accelerated atherosclerosis. Apoptosis is controlled by a different family of proteins including Bcl-2 and caspases. METHODS: To examine apoptosis in insulin resistance, we assessed the mRNA expression by qRT-PCR of several Bcl-2 family members, as well as caspase-3, -7, -8, and -9 in peripheral blood mononuclear cells (PBMCs) isolated from lean, obese, diabetic, and diabetic on metformin individuals. RESULTS: PBMCs of diabetic individuals exhibited reduced expression of caspase-7 and increased expression of Bcl-10, Bad, Bax, Bid, and caspase-3. T2DM on metformin group had significantly higher Bad, Bax, and caspase-7 expression. DISCUSSION: The moderate up-regulation of pro-apoptotic Bcl-10, Bax, Bad, Bid, and the effector caspase-3 coupled with inhibition of caspase-7 in circulating PBMCs of T2DM could be the result of increased inflammation in T2DM. Metformin treatment significantly inhibited the expression of Bcl-10, Bid, and caspase-3 and upregulated Bad/Bax/caspase-7 pathway suggesting the activation of Bad/Bax/caspase-7 apoptotic pathway. Further studies are warranted to elicit the underlying apoptotic pathways of PBMCs in T2DM and following metformin treatment.
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Vitamin D plays a pivotal role in intestinal homeostasis. Vitamin D can impact the function of virtually every cell in the gut by binding to its intracellular receptor (VDR) and subsequently transcribing relevant genes. In the lumen, the mucus layer and the underlying epithelium serve to keep resident microbiota at bay. Vitamin D ensures an appropriate level of antimicrobial peptides in the mucus and maintains epithelial integrity by reinforcing intercellular junctions. Should bacteria penetrate the epithelial layer and enter the interstitium, immune sentinel cells (e.g. macrophages, dendritic cells, and innate lymphoid cells) elicit inflammation and trigger the adaptive immune response by activating Th1/Th17 cells. Vitamin D/VDR signaling in these cells ensures clearance of the bacteria. Subsequently, vitamin D also quiets the adaptive immune system by suppressing the Th1/Th17 cells and favoring Treg cells. The importance of vitamin D/VDR signaling in intestinal homeostasis is evidenced by the development of a chronic inflammatory state (e.g. IBD) when this signaling system is disrupted.
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Mucosa Intestinal , Vitamina D/metabolismo , Imunidade Adaptativa , Animais , Microbioma Gastrointestinal , Homeostase , Humanos , Imunidade Inata , Imunomodulação , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologiaRESUMO
Serum 25-hydroxyvitamin D (25(OH)D) has been largely associated with latitude and sunshine exposure across several regions. According to previous results, 25(OH)D concentrations are, on average, relatively low in countries with abundant sunshine, including those of the Middle East and North Africa region, as well as lower-latitude Europe. The standard explanation for this phenomenon is that people wear concealing clothing because of cultural and religious practices and that high temperatures in summer limit direct sun exposure. However, the role of diet in the development of profound hypovitaminosis D has not been adequately explored in those countries. To examine how diet affects vitamin D status in the Middle Eastern and European countries, a search was conducted for papers from that region reporting 25(OH)D concentrations. Papers were sought that reported summertime and wintertime 25(OH)D concentrations for healthy nonpregnant adults representative of the entire population. Data from 15 Middle Eastern and European countries were found through this search. Data for postmenopausal women from 19 European countries were also obtained. Dietary supply data for animal products containing vitamin D (animal fat, eggs, ocean fish, animal meat, and milk) were obtained from the Food and Agriculture Organization of the United Nations. Latitude and a solar UVB dose index also were obtained for each country. For the 15-country study, energy from dietary factors was highly correlated with latitude, making it difficult to separate the effects of UVB exposure and dietary factors. However, for the 19-country study, dietary factors were only weakly correlated with latitude. In that study, ocean fish was the most important single dietary factor affecting serum 25(OH)D concentration for postmenopausal women in various European countries, but animal fat and meat also contributed. Because this is an ecological study, further research is encouraged to evaluate and extend the findings.
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Dieta , Raios Ultravioleta , Vitamina D/análogos & derivados , Animais , Gorduras na Dieta , Europa (Continente) , Feminino , Peixes , Humanos , Carne , Oriente Médio , Vitamina D/sangueRESUMO
Matrix metalloproteinases (MMPs) are a family of enzymes that degrade extracellular matrix components and are involved in the development and progression of cancer. Lung cancer is the most commonly diagnosed cancer in Lebanon. This study was undertaken to investigate the association between -1171(5A>6A) polymorphism in the promoter of MMP3 gene and the susceptibility to lung cancer in a Lebanese population. The MMP3 polymorphism was investigated in 41 lung cancer patients and 51 unrelated healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. We found a significant association between MMP3-1171 5A allele and lung cancer (Odds ratio [OR]=2.7, 95% [CI]=1.3-5.3; Fisher's p-value=0.005). This study may form an additional evidence for the association of MMP3 enzyme and genetic susceptibility to lung cancer.