Biomedical Research and Therapy

Detection of COVID-19 Patients through SARS-CoV-2 Antigen Assay using Chemiluminescence Immunoassay: Comparison to RT-PCR Method

Truong Thien Phu — 2024-04-30

Background: Accurate and reliable diagnostic tools are essential in effectively managing infectious diseases during the ongoing global COVID-19 pandemic. For this study, the RT-PCR assay was used as the reference method, and the objective was to determine the concordance rate, sensitivity, and specificity of the SARS-CoV-2 antigen assay (SARS-CoV-2 Ag) using the chemiluminescence immunoassay (CLEIA) technique for identifying COVID-19 patients.

Method: A total of 231 nasopharyngeal swab samples were collected from individuals with either COVID-19 (cycle threshold (Ct) values ≤ 40) or non-COVID-19 (Ct values > 40 or undetected) diagnoses. These samples were examined using the SARS-CoV-2 Ag.

Results: The overall concordance rate of the SARS-CoV-2 Ag was 84.0% (194/231), with a sensitivity of 81.4% (162/199) and 100% specificity (32/32). When samples were categorized into two Ct value groups, the SARS-CoV-2 Ag demonstrated a sensitivity of 97.6% for samples with a Ct value ≤ 30 and 2.9% for samples with a Ct value > 30. Moreover, the antigen concentration determined by the SARS-CoV-2 Ag showed a strong inverse correlation with the Ct value obtained from the RT-PCR assay (r = -0.93, p < 0.001).

Conclusion: The SARS-CoV-2 Ag proves to be a potentially effective tool for diagnosing and monitoring COVID-19 patients, particularly in settings where the RT-PCR assay is not available.

Harnessing Immune Checkpoint Inhibitors Against Gastric Cancer: Charting the Course to Expanded Therapeutic Benefit

Dang Thanh Chung — 2024-04-30

Cancer immunotherapy has become a groundbreaking approach in treatment, with immune checkpoint inhibitors (ICIs) showing exceptional success in blocking the pathways that tumors use to escape immune detection. This review delves into the clinical significance and predictive power of ICIs in the treatment of gastric cancer. It introduces ICIs, explaining their mechanisms of action, reviews key findings from critical trials, and discusses the role of programmed death ligand-1 (PDL1) testing as a potential biomarker for selecting suitable patients. The review also addresses the limitations of PD-L1 testing, while highlighting emerging predictive markers and ongoing research aimed at discovering novel biomarkers, optimizing therapeutic combinations, characterizing the tumor microenvironment, and understanding mechanisms of resistance to therapy. This effort to optimize ICIs aims to extend their significant clinical benefits to a larger group of patients with gastric cancer. In summary, this review provides specialists with an updated overview of the advancements in employing immunotherapy against gastric cancer and outlines the path towards enhancing patient outcomes through continuous research and the refinement of biomarkers.

Impact of Anthropometric and Genetic Factors on Plasma SIRT1 Level in Men with Essential Hypertension and Heart Failure

Starzhynska Olha Leonidivna — 2024-04-30

Introduction: Sirtuin 1 (SIRT1) emerges as a promising biomarker for heart remodeling in the context of essential arterial hypertension (EAH). Additionally, the levels of certain plasma peptides might signal myocardial fibrosis and the progression of heart failure (HF) in hypertensive patients. Despite this potential, conflicting data exist regarding the marker's diagnostic value in HF patients. This study aims to explore the impact of anthropometric factors on plasma SIRT1 levels in men diagnosed with EAH and HF, considering the rs7069102 single nucleotide polymorphism (SNP) in the SIRT1 gene.

Methods: The study included an examination of 190 Ukrainian men aged between 40 and 65. The participants were divided into two groups: a control group, consisting of 70 individuals without cardiovascular disease (CVD), and a study group comprising 120 men with EAH, 60 of whom displayed signs of HF. Plasma SIRT1 levels were quantified using an enzyme-linked immunosorbent assay (ELISA), while the rs7069102 C/G polymorphism in the SIRT1 gene was detected through allele-specific polymerase chain reaction (PCR). The research employed various statistical methods, including correlation analysis, T-test, Mann-Whitney U test, one-way ANOVA, and analysis of contingency tables for data analysis.

Results: The investigation revealed that men suffering from EAH and HF exhibited significantly reduced plasma SIRT1 levels (1.550 ± 0.084 ng/ml) compared to those with EAH but without HF (3.271 ± 0.238 ng/ml, p < 0.001). Notably, hypertensive men with concurrent HF and obesity or those with an early onset of hypertension showed even lower plasma SIRT1 concentrations. Interestingly, the analysis found no significant difference in plasma SIRT1 levels among individuals in the control group and EAH patients without HF across different rs7069102 C/G SNP variants. However, among hypertensive men with HF, individuals with the GG genotype displayed considerably lower plasma peptide levels compared to those with either the CC or CG genotype (1.390 ± 0.092 ng/ml vs. 1.744 ± 0.126 ng/ml, p = 0.032).

Conclusion: This study highlights a significant association between reduced plasma SIRT1 levels and heart failure in male patients with EAH. Factors contributing to decreased plasma peptide levels include obesity, early onset of hypertension, and possessing the GG variant of the rs7069102 SNP in the SIRT1 gene. These findings underscore the potential of SIRT1 as a marker for HF and may guide future therapeutic strategies.

Assessing LDL Cholesterol Management and Statin Use in Diabetic Patients: Disparities and Outcomes in a Vietnamese Tertiary Hospital Setting

Si Van Nguyen — 2024-04-30

Introduction: The control of low-density lipoprotein (LDL) cholesterol is a critical concern, especially for patients with diabetes, where the use of statins is essential. Despite this necessity, actual treatment practices and the achievement of LDL cholesterol targets are often suboptimal. This study aimed to assess the rate of LDL cholesterol goal attainment and examine statin prescribing habits within the cardiology and endocrinology departments of a tertiary hospital in Ho Chi Minh City, Vietnam.

Methods: This retrospective study encompassed 515 diabetic patients. We performed cardiovascular risk stratification to set appropriate LDL cholesterol goals for each patient. Through both univariate and multivariate analyses, we identified factors that influence LDL cholesterol management. Additionally, we reviewed patients' statin prescriptions before and after LDL cholesterol evaluation to understand prescribing patterns.

Results: Our study found that all included patients were categorized as having high or very high cardiovascular risk. A significant majority, 88.2%, were prescribed statins at an intermediate intensity. However, only 15.3% achieved their LDL cholesterol targets—21.7% in the high-risk category and a mere 9.4% in the very high-risk group. Factors conducive to effective LDL cholesterol management included being female, belonging to the very high cardiovascular risk group, and concurrent use of fibrates. Noticeably, among patients not meeting their LDL cholesterol goals, only 10.1% had their statin dosage increased post-evaluation. It was also observed that endocrinologists tended to reduce or discontinue statin dosages more often than cardiologists.

Conclusions: The rate at which diabetic patients in Vietnam meet their LDL cholesterol targets is alarmingly low. Priority should be given to female patients and those at very high cardiovascular risk to improve target attainment rates. There is a clear need for targeted interventions to enhance statin prescribing practices and, by extension, the management of LDL cholesterol in this population.

Kaempferol Rescues Vascular Endothelial Ferroptosis by Inhibiting Lipid Peroxidation

Li Wen — 2024-04-30

Introduction: The vascular endothelium plays a pivotal role in maintaining vascular function and physiological balance. The degradation and injury of endothelial cells are critical pathological events in the progression of vascular diseases, leading to cell death. One such cell death mechanism, ferroptosis, is an iron-dependent form of necrosis characterized by extensive lipid peroxidation-mediated membrane damage and the toxic effects of iron and lipid peroxidation. Kaempferol, a flavonoid, is celebrated for its antioxidant, anti-inflammatory, and anti-cancer properties. Despite these benefits, the impact of Kaempferol on endothelial cell ferroptosis and its potential therapeutic applications in vascular diseases have yet to be fully elucidated.

Methods: Cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay. Oxidative stress and lipid peroxidation were measured using Dihydroethidium (DHE) and C11-BODIPY 581/591, respectively. The protein and RNA levels of ferroptosis-associated molecules, including solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4), were determined through Western blotting and real-time fluorescence quantitative polymerase chain reaction (qPCR).

Results: Treatment with a glutathione peroxidase 4 inhibitor (RSL3) led to rapid cytotoxicity in human umbilical vein endothelial cells (HUVECs). Notably, Kaempferol demonstrated a significant protective effect against RSL3-induced ferroptosis in HUVECs. Kaempferol treatment reduced the accumulation of reactive oxygen species (ROS) and exhibited distinctive morphological changes associated with ferroptosis. Moreover, Kaempferol treatment resulted in the upregulation of SLC7A11 and GPX4 expression in HUVECs, highlighting its potent ability to mitigate ferroptosis among tested flavonoids.

Conclusions: Kaempferol effectively inhibited RSL3-induced ferroptosis in HUVECs by modulating the expression of SLC7A11 and GPX4, thereby reducing lipid peroxidation. These findings underscore the therapeutic potential of Kaempferol in the treatment of vascular diseases, paving the way for its application in clinical settings.

Large-scale separation and purification of exosomes using ionexchange chromatography

Wei-yuan Zhang — 2024-04-30

Introduction: With the growing interest in exosomes for research and therapeutic applications, there's a critical need for effective enrichment strategies that can isolate exosomes in large quantities without contaminants. Despite various methods being developed, none have satisfactorily achieved this goal without contamination issues. This study introduces a novel approach for exosome separation - ion-exchange chromatography (IEC) - that leverages the negatively charged phospholipids on the exosomal surface for more effective isolation.

Methods: The study developed a novel exosome separation strategy using ion-exchange chromatography (IEC) and compared it with the traditional ultracentrifugation (UC) method. The comparison focused on yield, purity, and the biological effects of the exosomes enriched by both methods. The new IEC method was tested alongside classical separation techniques like ultrafiltration for its efficiency in large-scale exosome extraction.

Results: Both UC and IEC efficiently enriched exosomes with high abundance, but IEC was superior in terms of lower protein contamination and better particle dispersion. Furthermore, exosomes enriched with IEC exhibited a stronger clonogenic effect on murine lung epithelial cells compared to those enriched by UC. In wound healing assays, exosomes isolated by both IEC and UC significantly improved the healing ratio in lung epithelial cells, showcasing the potential therapeutic benefits of the exosomes isolated by these methods.

Conclusion: The novel ion-exchange chromatography (IEC) method developed for exosome separation demonstrated significant advantages in terms of yield, purity, and biological effects when compared to traditional ultracentrifugation. The lower protein contamination and better particle dispersion achieved with IEC, along with its superior clonogenic and healing effects on lung epithelial cells, suggest that IEC can play a crucial role in future exosome separation strategies, particularly for large-scale applications.

The effect of L-arginine in the prevention of preeclampsia and intrauterine growth of the fetus in primigravid women: a randomized clinical trial

Shahede Khansari — 2024-04-30

Introduction: Given the limited research on the effect of L-arginine in preventing preeclampsia and intrauterine growth restriction (IUGR), coupled with the importance of preventing these conditions, this study was conducted to investigate the potential preventative role of L-arginine on preeclampsia and IUGR in primigravida women.

Methods: A single-blind randomized clinical trial was conducted with primigravida women attending Fatemieh Hospital in Hamadan city in 2021. An available sampling method was utilized to select the participants. The intervention group was treated with L-arginine at a dose of 1000 mg, along with prenatal supplements starting from the 20th week of pregnancy for twelve weeks, while the control group received only prenatal supplements. The occurrence of desired outcomes and preeclampsia, including blood pressure, proteinuria, and IUGR, was monitored and followed up until delivery.

Results: The mean age of mothers in the intervention and control groups was 35.8 ± 5.25 years and 39.4 ± 7.24 years, respectively (p = 0.31). The incidence of IUGR in the intervention group was significantly higher compared to the control group (12.66% vs. 2.7%, p = 0.033). Severe preeclampsia cases in the intervention group accounted for 5.41%, compared to 18.99% in the control group. Additionally, non-severe preeclampsia cases were more prevalent in the control group (p = 0.035).

Conclusion: In conclusion, the findings of this study suggest a potential role for L-arginine supplementation in reducing the incidence of preeclampsia and improving pregnancy outcomes. However, further research is needed to elucidate the underlying mechanisms, optimize treatment protocols, and evaluate long-term maternal and fetal outcomes.

Stimulation of Insulin Secretion and Inhibition of KATP Channels by Afzelechin and Coniferaldehyde from Ensete glaucum Seeds

Ly Hai Trieu — 2024-04-30

Introduction: Ensete glaucum seeds have been shown to possess antidiabetic properties. However, the specific hypoglycemic activities of the compounds they contain remain poorly understood. This study aimed to elucidate the hypoglycemic effects of E. glaucum seed compounds and to explore their mechanisms of action, particularly their interaction with pancreatic islets.

Methods: We employed spectroscopic techniques to determine the chemical structures of the isolated compounds, which we then compared with structures reported in the literature. In a streptozotocin (STZ)-induced diabetic mouse model, we evaluated the hypoglycemic response to an ethanol extract of E. glaucum seeds. Further, we assessed the islet-protective effects and the capacity to stimulate insulin release of both the crude extract and its individual compounds in STZ-challenged pancreatic islets.

Results: We isolated two novel compounds from E. glaucum seeds: afzelechin (a flavan-3-ol) and coniferaldehyde (a phenolic aldehyde), marking the first such report. Administration of the extract in doses of 25 and 50 mg/kg/day led to a significant reduction in blood glucose levels over a period of seven days in STZ-induced hyperglycemic mice. Notably, the extract and the isolated compounds afzelechin and coniferaldehyde exhibited a protective effect on islet β cells, mitigating STZ-induced cytotoxicity. Both the extract, at concentrations of 50 and 100 µg/mL, and the individual compounds, at 100 µM, demonstrated an ability to counteract STZ's inhibition of glucose-stimulated insulin secretion in isolated pancreatic islets. Importantly, molecular docking studies suggest that these compounds may stimulate insulin release from β cells by inhibiting the K_ATP channel, a hypothesis that warrants further experimental investigation.

Conclusion: Our findings suggest that E. glaucum seeds, along with their bioactive compounds, show promise in reducing blood sugar levels and enhancing insulin secretion, offering potential therapeutic avenues for diabetes management.

Autologous bone marrow-derived mesenchymal stem cells and endothelial progenitor cells transplantation showed potential benefits for type 2 diabetes mellitus Filipino patients: a case series

Mary Suzette A. De Guzman — 2024-04-30

Introduction: Type 2 diabetes mellitus (T2DM) is a serious metabolic disorder characterized by hyperglycemia and insulin resistance. Long-standing T2DM may lead to various macro- and microvascular complications such as diabetic nephropathy, neuropathy, and retinopathy. Currently available treatments for T2DM target high plasma glucose levels but do not address T2DM-associated complications. In this report, the therapeutic application of mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) transplantation in improving diabetic blood monitoring parameters among selected T2DM patients was investigated.

Methods: Five Filipino patients with T2DM diagnosed for more than five years agreed to participate in the autologous bone marrow-derived stem cell transplantation. Five milliliters (mL) per kilogram (kg) of bone marrow was collected from the patients following standard procedures, and bone marrow-derived stem cells underwent quantification, genetic typing, microbial analysis, and quality control before being infused into the patients. MSCs and EPCs were intravenously transfused into the patients once a month for 6 months. Fasting blood glucose (FBG), blood urea nitrogen (BUN), glycated hemoglobin (HbA1c), and creatinine (CREA) levels were recorded pre- and post-stem cell transplantation.

Results: The findings of the study revealed that the administration of autologous bone marrow-derived stem cells showed no adverse effects and improved or controlled the blood monitoring levels in most patients. Four out of five patients showed a reduction in their BUN (mean reduction = 2.246) and HbA1c (mean reduction = 0.74%) and maintained their creatinine levels within the normal range following the 6 months of infusion. Meanwhile, three out of five patients showed a decrease in FBG levels (mean reduction = 1.484 mmol/L).

Conclusion: This preliminary report suggests the potential of autologous bone marrow-derived stem cell transplantation for the treatment and management of T2DM. Future studies may focus on examining other parameters such as C-peptide levels and evaluate the efficacy and safety of autologous MSCs and EPCs in the long-term management of T2DM.