Corrigendum to "Glutathione Peroxidase Level in Patients with Vitiligo: A Meta-Analysis".
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ABSTRACT:
SUBMITTER: Xiao BH
PROVIDER: S-EPMC5529619 | biostudies-other | 2017
REPOSITORIES: biostudies-other
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Project description:The primary antioxidant, glutathione peroxidase (GPx), is hypothesized to contribute to the pathophysiology of malaria. This current study conducted a meta-analysis to examine variations in GPx blood levels in malaria patients. Seven electronic databases-ProQuest, Scopus, Embase, MEDLINE, PubMed, Ovid, and Google Scholar-were searched for relevant studies with no limitations to publication language or publication date. The Joanna Briggs Institute critical appraisal tools were used to appraise the risk of bias among the included studies critically. The meta-analysis was conducted by pooling the effect estimates and Hedges's g using a random-effects model. Search results returned 1253 articles, of which 16 studies were used for syntheses. Results of the meta-analysis indicated that malaria patients had decreased blood levels of GPx compared to uninfected individuals (P < 0.01, Hedges' g: - 4.06, 95% CI - 5.49-(- 2.63), I2: 99.07%, 1278 malaria patients/627 uninfected individuals, 15 studies). Subgroup analyses indicated that peripheral levels of GPx were significantly diminished in patients with P. falciparum malaria compared to uninfected controls (P < 0.01, Hedges' g: - 3.06, 95% CI - 4.46-(- 1.65), I2: 98.39%, 9 studies) but not in patients with P. vivax malaria (P = 0.15, Hedges' g: - 2.05, 95% CI - 4.83-0.74), I2: 98.64%, 2 studies) Overall, malaria is associated with declined levels of GPx, particularly in patients with P. falciparum malaria. The finding provides valuable insights that prompt the need to investigate the role of GPx depletion in malaria pathogenesis.
| S-EPMC10457399 | biostudies-literature
Project description:Correlation between intensity of free radical processes estimated by biochemiluminesce parameters, content of lipoperoxidation products, and changes of glutathione peroxidase (GP, EC 1.11.1.9) and glutathione reductase (GR, EC 1.6.4.2) activities at rats liver injury, after 12, 36, 70, 96, 110, and 125 hours & tetrachloromethane administration have been investigated. The histological examination of the liver sections of rats showed that prominent hepatocytes with marked vacuolisation and inflammatory cells which were arranged around the necrotic tissue are more at 96?h after exposure to CCl4. Moreover maximum increase in GR and GP activities, 2.1 and 2.5 times, respectively, was observed at 96?h after exposure to CCl4, what coincided with the maximum of free radical oxidation processes. Using a combination of reverse transcription and real-time polymerase chain reaction, expression of the glutathione peroxidase and glutathione reductase genes (Gpx1 and Gsr) was analyzed by the determination of their respective mRNAs in the rat liver tissue under toxic hepatitis conditions. The analyses of Gpx1 and Gsr expression revealed that the transcript levels increased in 2.5- and 3.0-folds, respectively. Western blot analysis revealed that the amounts of hepatic Gpx1 and Gsr proteins increased considerably after CCl4 administration. It can be proposed that the overexpression of these enzymes could be a mechanism of enhancement of hepatocytes tolerance to oxidative stress.
| S-EPMC3608198 | biostudies-literature
Project description:ObjectiveTo conduct a meta-analysis assessing the prevalence of vitiligo.MethodsLiteratures that reported prevalence rates of vitiligo were identified using EMBASE, PubMed, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang database and Weipu database for the period from inception to May 2016. We performed stratified analyses on possible sources of bias, including areas difference, years of publication, gender and age. Publication bias was assessed with Egger's test method.ResultsA total of 103 studies were eligible for inclusion. The pooled prevalence of vitiligo from 82 population- or community-based studies was 0.2% (95%CI: 0.1%-0.2%) and from 22 hospital-based studies was 1.8% (95%CI: 1.4%-2.1%). A relatively high prevalence of vitiligo was found in Africa area and in female patients. For population- or community-based studies, the prevalence has maintained at a low level in recent 20 years and it has increased with age gradually. For hospital-based studies, the prevalence has showed a decreased trend from 60s till now or from young to old. No significant publication bias existed in hospital-based studies (t = 0.47, P = 0.643), while a significant publication bias existed in population- or community-based studies (t = 2.31, P = 0.026).ConclusionA relatively high prevalence of vitiligo was found in Africa area and in female patients. The prevalence has maintained at a low level in recent years. It showed an inverse trend with age increment in population- or community-based studies and hospital-based studies.
| S-EPMC5038943 | biostudies-literature
Project description:Statins may exert protective effects against oxidative stress by upregulating specific antioxidant mechanisms. We conducted a systematic review and meta-analysis of the effect of statins on three key antioxidant enzymes: glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase. The electronic databases PubMed, Web of Science, and Scopus were searched from inception to July 2021. The risk of bias was assessed with the Joanna Briggs Institute Critical Appraisal Checklist and certainty of evidence was assessed using the GRADE framework. In 15 studies, reporting 17 treatment arms in 773 patients (mean age 53 years, 54% males), statins significantly increased the concentrations of both GPx (standardized mean difference, SMD = 0.80, 95% confidence interval, CI 0.13 to 1.46, p = 0.018; high certainty of evidence) and SOD (SMD = 1.54, 95% CI 0.71 to 2.36, p < 0.001; high certainty of evidence), but not catalase (SMD = -0.16, 95% CI -0.51 to 0.20, p = 0.394; very low certainty of evidence). The pooled SMD values were not altered in sensitivity analysis. There was no publication bias. In conclusion, statin treatment significantly increases the circulating concentrations of GPx and SOD, suggesting an antioxidant effect of these agents (PROSPERO registration number: CRD42021271589).
| S-EPMC8614838 | biostudies-literature
Project description:Selenium may play a beneficial role in multi-factorial illnesses with genetic and environmental linkages via epigenetic regulation in part via glutathione peroxidase (GPx) activity. A meta-analysis was undertaken to quantify the effects of dietary selenium supplementation on the activity of overall GPx activity in different tissues and animal species and to compare the effectiveness of different forms of dietary selenium. GPx activity response was affected by both the dose and form of selenium (p < 0.001). There were differences between tissues on the effects of selenium supplementation on GPx activity (p < 0.001); however, there was no evidence in the data of differences between animal species (p = 0.95). The interactions between dose and tissue, animal species and form were significant (p < 0.001). Tissues particularly sensitive to changes in selenium supply include red blood cells, kidney and muscle. The meta-analysis identified that for animal species selenium-enriched foods were more effective than selenomethionine at increasing GPx activity.
| S-EPMC4210904 | biostudies-literature
Project description:BackgroundGlutathione (GSH) is one of the most important agents of the antioxidant defense system of the cell because, in conjunction with the enzymes glutathione peroxidase (GSH-Px) and glutathione S transferase pi (GSTpi), it plays a central role in the detoxification and biotransformation of chemotherapeutic drugs. This study evaluated the expression of GSH and the GSH-Px and GSTpi enzymes by immunohistochemistry in 30 canine mammary tumors, relating the clinicopathological parameters, clinical outcome and survival of the bitches. In an in vitro study, the expression of the genes glutamate cysteine ligase (GCLC) and glutathione synthetase (GSS) that synthesize GSH and GSH-Px gene were verified by qPCR and subjected to treatment with doxorubicin, to check the resistance of cancer cells to chemotherapy.ResultsThe immunohistochemical expression of GSH, GSH-Px and GSTpi was compared with the clinical and pathological characteristics and the clinical outcome in the bitches, including metastasis and death.The results showed that high immunoexpression of GSH was correlated to the absence of tumor ulceration and was present in dogs without metastasis (P < 0.05). There was significant correlation of survival with the increase of GSH (P < 0.05). The expression of the GSH-Px and GSTpi enzymes showed no statistically significant correlation with the analyzed variables (p > 0.05). The analysis of the relative expression of genes responsible for the synthesis of GSH (GCLC and GSS) and GSH-Px by quantitative PCR was done with cultured cells of 10 tumor fragments from dogs with mammary tumors.The culture cells showed a decrease in GCLC and GSS expression when compared with no treated cells (P < 0.05). High GSH immunoexpression was associated with better clinical outcomes.ConclusionTherefore, high expression of the GSH seems to play an important role in the clinical outcome of patients with mammary tumors and suggest its use as prognostic marker. The in vitro doxorubicin treatment significantly reduces the expression of GCLC and GSS genes so we can consider them to be candidates for predictive markers of therapeutic response in mammary cancer.
| S-EPMC3975948 | biostudies-literature
Project description:[This corrects the article DOI: 10.3389/fimmu.2021.709155.].
| S-EPMC8603401 | biostudies-literature
Project description:ImportanceReferences to the expected treatment response to phototherapy would be helpful in the management of vitiligo because phototherapy requires long treatment durations over several months.ObjectiveTo estimate the treatment response of vitiligo to phototherapy.Data sourcesA comprehensive database search of MEDLINE, EMBASE, and the Cochrane library from inception to January 26, 2016, was performed for all prospective studies. The main keywords used were vitiligo, phototherapy, psoralen, PUVA, ultraviolet, NBUVB, and narrowband.Study selectionAll prospective studies reporting phototherapy outcome for at least 10 participants with generalized vitiligo were included. Of 319 studies initially identified, the full texts of 141 studies were assessed for eligibility, and 35 were finally included in the analysis. Of these, 29 studies included 1201 patients undergoing narrowband UV-B (NBUVB) phototherapy, and 9 included 227 patients undergoing psoralen-UV-A (PUVA) phototherapy.Data extraction and synthesisTwo reviewers independently extracted the following data: study design, number and characteristics of the participants, phototherapy protocol, and rate of repigmentation based on the quartile scale. Single-arm meta-analyses were performed for the NBUVB and PUVA groups. Sample size-weighted means were calculated using a random-effects model for the repigmentation rates of the included studies.Main outcomes and measuresThe primary outcomes were at least mild (≥25%), at least moderate (≥50%), and marked (≥75%) responses on a quartile scale. Response rates were calculated as the number of participants who showed the corresponding repigmentation divided by the number of all participants enrolled in the individual studies.ResultsThe meta-analysis included 35 unique studies (1428 unique patients). For NBUVB phototherapy, an at least mild response occurred in 62.1% (95% CI, 46.9%-77.3%) of 130 patients in 3 studies at 3 months, 74.2% (95% CI, 68.5%-79.8%) of 232 patients in 11 studies at 6 months, and 75.0% (95% CI, 60.9%-89.2%) of 512 patients in 8 studies at 12 months. A marked response was achieved in 13.0% (95% CI, 2.1%-23.9%) of 106 patients in 2 studies at 3 months, 19.2% (95% CI, 11.4%-27.0%) of 266 patients in 13 studies at 6 months, and 35.7% (95% CI, 21.5%-49.9%) of 540 patients in 9 studies at 12 months. For PUVA phototherapy, an at least mild response occurred in 51.4% (95% CI, 28.1%-74.7%) of 103 patients in 4 studies at 6 months and 61.6% (95% CI, 20.2%-100%) of 72 patients in 3 studies at 12 months. In the subgroup analyses, marked responses were achieved on the face and neck in 44.2% (95% CI, 24.2%-64.2%), on the trunk in 26.1% (95% CI, 8.7%-43.5%), on the extremities in 17.3% (95% CI, 8.2%-26.5%), and on the hands and feet in none after at least 6 months of NBUVB phototherapy.Conclusions and relevanceLong-duration phototherapy should be encouraged to enhance the treatment response in vitiligo. The greatest response is anticipated on the face and neck.
| S-EPMC5817459 | biostudies-literature
Project description:BackgroundVitiligo is an acquired depigmenting skin disease which is often accompanied by mental distress. There are numerous studies dedicated to local and global prevalence of depression in patients with vitiligo but anxiety has not been recognized as a major mental problem within named population. We aimed to evaluate the prevalence of anxiety among patients with vitiligo from different countries and to compare it with patients suffering from eczema, psoriasis, and acne.MethodsIn November 2019, we conducted a systematic search for observational studies that examined the prevalence of anxiety in vitiligo patients. Fifteen studies comprising 1176 patients with vitiligo were included to our systematic review.ResultsThe general prevalence of anxiety among vitiligo patients was equal to 35.8%. Statistically significant difference in anxiety rates was found among female and male patients (47.32% vs 42.4%) (P = 0.03), but the clinical relevance of this issue remains arguable. In addition, the pooled odds ratio among vitiligo and non-vitiligo patients did not indicate a statistical significance among patients coming from different continents.ConclusionsThe pooled prevalence of anxiety among vitiligo patients worldwide was comparable to other severe skin disorders. This finding accentuates the necessity of anxiety awareness in management of patients with skin diseases.
| S-EPMC7654800 | biostudies-literature
Project description:Trypanosoma brucei, the causative agent of African sleeping sickness, encodes three nearly identical genes for cysteine-homologues of the selenocysteine-containing glutathione peroxidases. The enzymes, which are essential for the parasites, lack glutathione peroxidase activity but catalyse the trypanothione/Tpx (tryparedoxin)-dependent reduction of hydroperoxides. Cys47, Gln82 and Trp137 correspond to the selenocysteine, glutamine and tryptophan catalytic triad of the mammalian selenoenzymes. Site-directed mutagenesis revealed that Cys47 and Gln82 are essential. A glycine mutant of Trp137 had 13% of wild-type activity, which suggests that the aromatic residue may play a structural role but is not directly involved in catalysis. Cys95, which is conserved in related yeast and plant proteins but not in the mammalian selenoenzymes, proved to be essential as well. In contrast, replacement of the highly conserved Cys76 by a serine residue resulted in a fully active enzyme species and its role remains unknown. Thr50, proposed to stabilize the thiolate anion at Cys47, is also not essential for catalysis. Treatment of the C76S/C95S but not of the C47S/C76S double mutant with H2O2 induced formation of a sulfinic acid and covalent homodimers in accordance with Cys47 being the peroxidative active site thiol. In the wild-type peroxidase, these oxidations are prevented by formation of an intramolecular disulfide bridge between Cys47 and Cys95. As shown by MS, regeneration of the reduced enzyme by Tpx involves a transient mixed disulfide between Cys95 of the peroxidase and Cys40 of Tpx. The catalytic mechanism of the Tpx peroxidase resembles that of atypical 2-Cys-peroxiredoxins but is distinct from that of the selenoenzymes.
| S-EPMC2267296 | biostudies-literature