Therapeutic effects of high-dose vitamin C supplementation in patients with COVID-19: a meta-analysis.

CONTEXT: Coronavirus disease 2019 (COVID-19) could induce the "cytokine storm" due to overactivation of immune system and accompanied by acute respiratory distress syndrome as a serious complication. Vitamin C has been effective in improving lung function of patients by reducing inflammation. OBJECTIVE: The aim was to explore the therapeutic effects of high-dose vitamin C supplementation for patients with COVID-19 using meta-analysis. DATA SOURCES: Published studies were searched from PubMed, Cochrane Library, Web of Science, EMBASE, and China National Knowledge Infrastructure databases up to August 2022 using the terms "vitamin C" and "COVID-19". Data analyses were performed independently by 2 researchers using the PRISMA guidelines. DATA EXTRACTION: Heterogeneity between the included studies was assessed using I2 statistics. When I2 ≥50%, the random-effects model was used; otherwise, a fixed-effects model was applied. Stata 14.0 software was used to pool data by standardized mean differences (SMDs) with 95% CIs or odds ratios (ORs) with 95% CIs. DATA ANALYSIS: The 14 studies had a total of 751 patients and 1583 control participants in 7 randomized controlled trials and 7 retrospective studies. The vitamin C supplement significantly increased ferritin (SMD = 0.272; 95% CI: 0.059 to 0.485; P = 0.012) and lymphocyte count levels (SMD = 0.376; 95% CI: 0.153 to 0.599; P = 0.001) in patients with COVID-19. Patients administered vitamin C in the length of intensive care unit staying (SMD = 0.226; 95% CI: 0.073 to 0.379; P = 0.004). Intake of vitamin C prominently alleviate disease aggravation (OR = 0.344, 95%CI: 0.135 to 0.873, P = 0.025). CONCLUSIONS: High-dose vitamin C supplementation can alleviate inflammatory response and hinder the aggravation of COVID-19.

Selenomethionine Antagonized microRNAs Involved in Apoptosis of Rat Articular Cartilage Induced by T-2 Toxin.

T-2 toxin and selenium deficiency are considered important etiologies of Kashin-Beck disease (KBD), although the exact mechanism is still unclear. To identify differentially expressed microRNAs (DE-miRNAs) in the articular cartilage of rats exposed to T-2 toxin and selenomethionine (SeMet) supplementation, thirty-six 4-week-old Sprague Dawley rats were divided into a control group (gavaged with 4% anhydrous ethanol), a T-2 group (gavaged with 100 ng/g·bw/day T-2 toxin), and a T-2 + SeMet group (gavaged with 100 ng/g·bw/day T-2 toxin and 0.5 mg/kg·bw/day SeMet), respectively. Toluidine blue staining was performed to detect the pathological changes of articular cartilage. Three rats per group were randomly selected for high-throughput sequencing of articular cartilage. Target genes of DE-miRNAs were predicted using miRanda and RNAhybrid databases, and the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway were enriched. The network map of miRNA-target genes was constructed using Cytoscape software. The expression profiles of miRNAs associated with KBD were obtained from the Gene Expression Omnibus database. Additionally, the DE-miRNAs were selected for real-time quantitative PCR (RT-qPCR) verification. Toluidine blue staining demonstrated that T-2 toxin damaged articular cartilage and SeMet effectively alleviated articular cartilage lesions. A total of 50 DE-miRNAs (28 upregulated and 22 downregulated) in the T-2 group vs. the control group, 18 DE-miRNAs (6 upregulated and 12 downregulated) in the T-2 + SeMet group vs. the control group, and 25 DE-miRNAs (5 upregulated and 20 downregulated) in the T-2 + SeMet group vs. the T-2 group were identified. Enrichment analysis showed the target genes of DE-miRNAs were associated with apoptosis, and in the MAPK and TGF-ß signaling pathways in the T-2 group vs. the control group. However, the pathway of apoptosis was not significant in the T-2 + SeMet group vs. the control group. These results indicated that T-2 toxin induced apoptosis, whereas SeMet supplementation antagonized apoptosis. Apoptosis and autophagy occurred simultaneously in the T-2 + SeMet group vs. T-2 group, and autophagy may inhibit apoptosis to protect cartilage. Compared with the GSE186593 dataset, the evidence of miR-133a-3p involved in apoptosis was more abundant. The results of RT-qPCR validation were consistent with RNA sequencing results. Our findings suggested that apoptosis was involved in articular cartilage lesions induced by T-2 toxin, whereas SeMet supplementation antagonized apoptosis, and that miR-133a-3p most probably played a central role in the apoptosis process.

Pseudolaric Acid B Attenuates High Salt Intake-Induced Hypertensive Left Ventricular Remodeling by Modulating Monocyte/Macrophage Phenotypes.

BACKGROUND Studies in ApoE knockout mice have shown that pseudolaric acid B (PB) can act as an immunomodulatory drug and attenuate atherosclerosis progression by modulating monocyte/macrophage phenotypes. Our previous study demonstrated that high salt intake could shift the phenotype of monocytes/macrophages to an inflammatory phenotype, and that this shift was related to hypertension and hypertensive left ventricular (LV) remodeling. However, no comprehensive assessment of the effects of PB on hypertensive LV remodeling has been conducted. MATERIAL AND METHODS In this study, RAW264.7 macrophages cultured with different concentrations of NaCl were used to investigate the modulating effects of PB on macrophage phenotype. Furthermore, N-nitro-L-arginine methyl ester hypertensive mice were used to investigate the modulating effects of PB on monocyte phenotype. LV remodeling was investigated by echocardiography. LV morphologic staining (for cardiomyocyte hypertrophy and collagen deposition) was performed at the time of sacrifice. RESULTS The results showed that PB significantly improved the viability of RAW264.7 cells, suppressed their phagocytic and migration abilities, and inhibited their phenotypic shift to M1 macrophages. In addition, the blood pressure of PB-treated mice was significantly decreased relative to that of control mice. Furthermore, after PB treatment, the percentage of Ly6Chi monocytes was significantly decreased while that of Ly6Clo monocytes was apparently increased. Moreover, PB preserved LV function and alleviated myocardial fibrosis and cardiomyocyte hypertrophy as measured at the end of the experimental period. The transfer of monocytes from PB-treated mice to hypertensive mice achieved the same effects. CONCLUSIONS Together, these findings indicate that PB exerts its protective effects on hypertensive LV remodeling by modulating monocyte/macrophage phenotypes and warrants further investigation.

Preparation of dummy molecularly imprinted polymers based on dextran-modified magnetic nanoparticles Fe3O4 for the selective detection of acrylamide in potato chips.

Novel dummy magnetic molecularly imprinted polymers (dex-MMIPs) were prepared for highly selective recognition and fast enrichment of acrylamide (AA) in potato chips. Propionamide (PA) was used as dummy template molecule and the Fe3O4 nanoparticles modified with carboxymethyl dextran were developed as supports. Methacrylic acid (MAA) and ethyleneglycoldimethacrylate (EGDMA) were chosen as the functional monomer and cross-linker, respectively. Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) were used to characterize the synthesized dex-MMIPs. The adsorption of dex-MMIPs reached equilibrium within 20 min, and the maximum adsorption quantity (Qm) was 19.28 mg/g with the dissociation constant (Kd) of 35.7 mg/L. Moreover excellent recognition toward acrylamide was achieved compared to analogs, such as N, N'-methylenebisacrylamide (MBA) and nicotinamide (VPP). The satisfactory recoveries of 83.9-96.8% were achieved for selective separation and enrichment of AA in spiked potato chips by dex-MMIPs.

Prevention and control strategies for children Kashin-Beck disease in China: A systematic review and meta-analysis.

BACKGROUND: To evaluate prevention and control strategies for children with Kashin-Beck disease (KBD) in China through a systematic review and meta-analysis. METHODS: We conducted literature searches of articles indexed in Web of Knowledge, PubMed, Springerlink, Elsevier, the Chinese National Knowledge Infrastructure, and Wanfang data until February 2019. Search terms included "Kashin-Beck disease" or "KBD," and "improvement of water" or "change of grain" or "salt-rich selenium" or "comprehensive measures." Eligible studies were prospective trials of interventions in endemic area. Data extraction was performed by 2 independent authors using predefined data fields that also included quality evaluation. RESULTS: We screened 1183 potentially relevant articles, and included 22 studies that reported 24 trials, with data from 3700 healthy children and 2961 children KBD. The pooled odds ratios (ORs) and confidence intervals (95% CIs) for primary prevention new incidence in healthy children following interventions to comprehensive measures, change of grain, salt-rich selenium, and improvements of water were 0.15 (0.02, 0.95), 0.15 (0.03, 0.70), 0.19 (0.09, 0.38), and 0.20 (0.09, 0.42), respectively. The OR (95% CI) for clinical improvement in children KBD following interventions to improvement of water, salt-rich selenium, comprehensive measures, and change of grain were 5.03 (3.21, 7.89), 4.39 (3.15, 6.11), 2.98 (1.61, 5.52), and 2.35 (1.59, 3.47), respectively. All interventions showed significant differences and were effective (P < .05). CONCLUSION: Comprehensive measures and change of grain were the most effective measures in preventing new case, whereas improvement of water and salt-rich selenium resulted in clinical improvements in children KBD.

Associations Between Selenium Content in Hair and Kashin-Beck Disease/Keshan Disease in Children in Northwestern China: a Prospective Cohort Study.

The objective of this study was to investigate the relationship between selenium content in hair and the incidence of Kashin-Beck disease (KBD) and Keshan disease (KD) in China. A prospective cohort study was conducted among children aged 5-12 years with different levels of low-selenium (group 1, Se ≤ 110 ng/g; group 2, 110 < Se ≤ 150 ng/g; and group 3, 150 < Se ≤ 200 ng/g) or selenium-supplemented (group 4, Se > 200 ng/g) exposure. A person-years approach was used to calculate the incidence and rate of positive clinical signs. Relative risk (RR), attributable risk, and etiologic fraction were used to determine the strength of association between selenium and disease incidence. Seven new KBD cases were diagnosed during 3-year follow-up. Positive clinical signs of KBD were found in 17.78 (95% confidence interval [CI] 14.27-21.29) cases per 100 person-years in group 1, 13.28 (9.82-16.74) in group 2, 12.95 (9.34-16.56) in group 3, and 8.18 (5.50-10.85) in group 4. Compared with group 4, the RR (95% CI) of groups 1, 2, and 3 were 2.17 (1.48-3.19), 1.62 (1.07-2.47), and 1.58 (1.03-2.43), respectively. Positive clinical signs of KD were 25.90 (18.62-33.18) cases per 100 person-years in group 1, 5.66 (1.26-10.06) in group 2, 4.60 (0.20-9.00) in group 3, and 14.62 (8.54-20.69) in group 4. Compared with group 4, the RR (95% CI) were 1.77 (1.07-2.93), 0.39 (0.16-0.93), and 0.31 (0.11-0.89), respectively. In children, the onset of KBD was negatively correlated with selenium content within a certain range. However, there may be a U-shaped association between selenium content and KD in children.

Selenium promotes metabolic conversion of T-2 toxin to HT-2 toxin in cultured human chondrocytes.

To explore the metabolism of T-2 toxin in human chondrocytes (HCs) and determine the impact of selenium supplementation. For determination of cytotoxicity using the MTT assay, optical density values were read with an automatic enzyme-linked immunosorbent assay reader at 510nm. Cell survival was calculated and the cytotoxicity estimated. To identify the metabolites of T-2 toxin, the medium supernatants and C28/I2 cells were analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) separately. For HPLC-MS/MS, the mobile phase A was water and phase B was 98% methanol. The gradient for the elution was: 0-0.5min, 50% of B; 0.5-2.0min, 100% of B; 2.0-3.5min, 100% of B; 3.6-6min, 50% of B. T-2 toxin increased the toxicity to C28/I2 cells significantly in a dose- and time-dependent manner (viability range 91.5-22.0%). Supplementation with selenium (100ng/mL) could increase the cell viability after the 24h incubation. The concentration of T-2 toxin in the cell medium decreased from 20 to 6.67±1.02ng/mL, and the concentration of HT-2 toxin increased from 0 to 6.88±1.23ng/mL during the 48h incubation, whereas the relative concentration of T-2 toxin in cells increased from 0 to 12.80±1.84ng/g. Supplementary selenium in the HCs cultures reduced the cytotoxicity induced by T-2 toxin significantly, and was associated with rapid conversion of T-2 toxin in the culture medium to HT-2 toxin. T-2 toxin was more toxic to HCs than HT-2 toxin at equivalent concentrations. HT-2 toxin was a detectable metabolite of T-2 toxin in cultured HCs, and selenium enhanced the metabolic conversion of T-2 toxin, reducing its cytotoxicity to HCs.

Zinc: the Other Suspected Environmental Factor in Kashin-Beck Disease in Addition to Selenium.

Kashin-Beck disease (KBD) is an endemic chronic osteochondral disease characterized by high prevalence, disability, and morbidity and is distributed from the northeast to the southwest in China, in some regions of Eastern Siberia in Russia, and in North Korea. Although the selenium deficiency etiological hypothesis for KBD has been proposed by scientists for decades, the idea that selenium deficiency is one of the most important environmental factors but not the primary and sole pathogenic factor for KBD has been widely accepted. Zn2+, which is closely involved in the synthesis of enzymes, nucleic acids, and proteins, is an essential microelement in vivo. A conundrum still exists in research on the relationship between Zn2+ and KBD due to inconsistent results, but it has been confirmed that Zn2+ can help repair metaphyseal lesions in patients with KBD, indicating that Zn2+ might play a key role in the pathogenesis of KBD, although the mechanism is unknown. The zinc-ZIP8-MTF1 axis in chondrocytes forms a catabolic cascade that promotes upregulation of the crucial effector matrix-degrading enzymes MMP3, MMP13, and ADAMTS5, thereby leading to osteoarthritis (OA) cartilage destruction. Zinc finger protein-related genes, the ZNT family, and the ZIP family of Zn2+ transporter genes have been found to be differentially expressed in KBD by high-throughput screening. Therefore, Zn2+ could play a key role in the pathogenesis of KBD.

Integrative Multivariate Logistic Regression Analysis of Risk Factors for Kashin-Beck disease.

To determine the current evidence on risk factors for Kashin-Beck disease (KBD) using an integrative meta-analysis. We searched five English and three Chinese databases from inception to September 2015, to identify case-control studies that examined risk factors for KBD using multivariate logistic analysis. DerSimonian and Laird effective models are applied in processing data using pooled odds ratios (ORs) and 95 % confidence intervals (CI). Seven studies were identified with 3087 cases and 6402 controls. The main risk factors found to be significantly associated with the onset of KBD were age (OR 1.19, 95 % CI 1.10-1.28), parents prevalence (OR 5.16, 2.51-7.80), family hygiene (OR 1.68, 1.42-1.93), food source (OR 3.29, 2.38-4.19), wheat (OR 1.12, 1.08-1.16), wheat germ necrosis rate (OR 6.03, 1.87-12.92), total volatile basic nitrogen (OR 6.85, 1.01-28.67), low selenium in hair (OR 2.29, 1.08-3.50) were found to be significant risks factors. The pooled ORs (95 % CI) of protein intake and rice were 0.79 (0.66-0.93) and 0.90 (0.86-0.95), respectively, indicating that the two factors may be protective for KBD. We found that the combination of low protein intake, polluted grain, and selenium deficiency may contribute to be onset of KBD together.

Salt-Rich Selenium for Prevention and Control Children with Kashin-Beck Disease: a Meta-analysis of Community-Based Trial.

Kashin-Beck disease (KBD) in western China is not well controlled. The objective of this study is to evaluate prevention and control children with KBD through a meta-analysis of a community-based trial. Web of knowledge, PubMed, Elsevier, the Chinese National Knowledge Infrastructure (CNKI), VIP and Wanfang data had been electronically searched up to February 2015. Search terms included the trial terms "Salt rich selenium" and "Kashin-Beck disease." Eligible studies were prospective trials of salt-rich selenium in endemic villages. Data extraction was performed by two authors using predefined data fields that also included quality evaluation. Of 292 potentially relevant articles initially screened, reporting 11 community-based trials with a total enrollment of 2652 participants were included, from five provinces in China. The pooled odds ratios (OR) and 95 % confidence intervals (CI) of primary prevention in healthy children were 0.16 and 0.08∼0.33, respectively. The OR and 95 % CI of clinical improvement in KBD children were 6.57 and 3.33∼12.93, respectively. The OR of repairing rate of metaphysis lesions was 5.53 (95 % CI 2.92∼10.47) based on X-ray film, which was statistically significantly different in favor of salt-rich selenium. The combined standard mean difference (SMD) of selenium content in hair was 2.54 (95 % CI 1.21∼3.87) which was significantly higher in selenium group. Current evidence showed that supplement salt-rich selenium was effective in reducing new incidence in healthy children and clinical improvement including repairing metaphysis lesions instead of repairing distal end of phalanx lesions in KBD children.

Selenium and Iodine Levels in Subjects with Kashin-Beck Disease: a Meta-analysis.

Kashin-Beck disease (KBD) is an endemic, degenerative osteoarthropathy, and particularly seen in China. A deficiency of selenium and iodine is implicated as the main etiological factor for KBD. This meta-analysis aimed to evaluate the differences in the selenium and iodine levels between patients with KBD and healthy individuals. Eligible articles published before March 6, 2015 were searched from four electronic databases. Data extraction and quality assessment of included studies were performed by two independent reviewers. Results were summarized as standardized mean difference (SMD) with 95 % confidence intervals (CIs). Cohen's d test was used to estimate the difference of the effect size between patients with KBD and healthy controls. A total of 26 cross-sectional studies were included in the meta-analysis. The pooled SMD showed that the whole blood selenium (Cohen's d = 4.39, P < 0.001), serum selenium (Cohen's d = 2.42, P = 0.015), hair selenium (Cohen's d = 5.46, P < 0.001), and urinary selenium (Cohen's d = 4.16, P < 0.001) levels were significantly lower in patients with KBD than that in healthy controls. There was no significant difference of plasma selenium (Cohen's d = 0.08, P = 0.936) and urinary iodine (Cohen's d = 0.33, P = 0.744) levels between subjects with KBD and healthy controls. In conclusion, the levels of selenium, but not iodine were significantly lower in subjects with KBD than that in healthy controls. Selenium deficiency might be associated with the risk of KBD.