Factors associated with the disease family burden of caregivers of myasthenia gravis patients in northwestern China: A cross-sectional study.

BACKGROUND: Patients with myasthenia gravis (MG) lose part of their working or living ability due to illness, and bring burden to caregivers. The purpose of this study was to explore the factors related to caregivers' disease family burden for MG patients in Northwest China. METHODS: The study utilized our Myasthenia Gravis database and distributed online questionnaires to both MG patients and their caregivers. The questionnaires included a general data collection form, the Patient Health Questionnaire-9 (PHQ-9) scale, and the Caregivers' Family Burden Scale of Disease (FBSD). Univariate analysis and multivariate linear regression analysis were run, with FBSD as the outcome variable for separate analyses. RESULTS: 178 MG patients were eligible for inclusion in the analysis, of whom 80 patients' caregivers had a positive family burden of MG. The daily activity burden of the family and the economic burden of the family were the heaviest among the six dimensions of the caregivers' family disease burdens. The factors independently associated with FBSD were depression symptom level, MG severity classification and family's monthly per capita income (p < 0.05). CONCLUSIONS: Depression symptom level, MG severity classification and family's monthly per capita income are independent factors related to the caregivers' disease family burden for MG patients.

Safety of COVID-19 vaccine in patients with myasthenia gravis: a self-controlled case series study.

Background: The safety of COVID-19 vaccines has been clarified in clinical trials; however, some immunocompromised patients, such as myasthenia gravis (MG) patients, are still hesitant to receive vaccines. Whether COVID-19 vaccination increases the risk of disease worsening in these patients remains unknown. This study aims to evaluate the risk of disease exacerbation in COVID-19-vaccinated MG patients. Methods: The data in this study were collected from the MG database at Tangdu Hospital, the Fourth Military Medical University, and the Tertiary Referral Diagnostic Center at Huashan Hospital, Fudan University, from 1 April 2022 to 31 October 2022. A self-controlled case series method was applied, and the incidence rate ratios were calculated in the prespecified risk period using conditional Poisson regression. Results: Inactivated COVID-19 vaccines did not increase the risk of disease exacerbation in MG patients with stable disease status. A few patients experienced transient disease worsening, but the symptoms were mild. It is noted that more attention should be paid to thymoma-related MG, especially within 1 week after COVID-19 vaccination. Conclusion: COVID-19 vaccination has no long-term impact on MG relapse.

Folic Acid supplementation stimulates notch signaling and cell proliferation in embryonic neural stem cells.

The present study investigated the effect of folic acid supplementation on the Notch signaling pathway and cell proliferation in rat embryonic neural stem cells (NSCs). The NSCs were isolated from E14-16 rat brain and grown as neurospheres in serum-free suspension culture. Individual cultures were assigned to one of 3 treatment groups that differed according to the concentration of folic acid in the medium: Control (baseline folic acid concentration of 4 mg/l), low folic acid supplementation (4 mg/l above baseline, Folate-L) and high folic acid supplementation (40 mg/l above baseline, Folate-H). NSCs were identified by their expression of immunoreactive nestin and proliferating cells by incorporation of 5'bromo-2'deoxyuridine. Cell proliferation was also assessed by methyl thiazolyl tetrazolium assay. Notch signaling was analyzed by real-time PCR and western blot analyses of the expression of Notch1 and hairy and enhancer of split 5 (Hes5). Supplementation of NSCs with folic acid increased the mRNA and protein expression levels of Notch1 and Hes5. Folic acid supplementation also stimulated NSC proliferation dose-dependently. Embryonic NSCs respond to folic acid supplementation with increased Notch signaling and cell proliferation. This mechanism may mediate the effects of folic acid supplementation on neurogenesis in the embryonic nervous system.

Folate stimulates ERK1/2 phosphorylation and cell proliferation in fetal neural stem cells.

Cellular events for neural progenitor cells, such as proliferation and differentiation, are regulated by multiple intrinsic and extrinsic cell signals. Folate plays central roles in central nervous system development, so folate, as an extrinsic signal, may affect neural stem cell (NSC) proliferation and differentiation. In this study, we have investigated the effect of folate on extracellular signal-regulated kinase (ERK1/2) phosphorylation, cell proliferation and apoptosis in fetal NSCs. The results showed that treatment of neurospheres with folate increased ERK1/2 phosphorylation and cell proliferation in a concentration-dependent manner. Folate also decreased the percentage of apoptotic cells. All of these effects of folate were prevented by a selective inhibitor (U0126) of mitogen-activated/ERK kinase 1/2. In conclusion, fetal NSCs respond to folate with ERKl/2 phosphorylation, cell proliferation and decreased apoptosis. This mechanism may mediate the regulation by folate of neurogenesis in the central nervous system.

Folate deficiency induces neural stem cell apoptosis by increasing homocysteine in vitro.

Cellular events for neural progenitor cells, such as proliferation and differentiation, are regulated by multiple intrinsic and extrinsic cell signals. Folate plays a central role in central nervous system development, so folate, as an extrinsic signal, may affect neural stem cell (NSC) proliferation and differentiation. In the present study, we investigated the effects of folate deficiency on the cell proliferation, cell apoptosis and homocysteine concentrations in NSCs. NSCs were isolated from fetal rats and identified as NSCs by their expression of immunoreactive nestin. Cell proliferation was quantitated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptotic cells were detected and confirmed by flow cytometric analysis. We measured homocysteine concentrations in NSCs by high performance liquid chromatography and detected the expression of caspase-3 by western blot method. Folate deficiency not only decreased cell proliferation, but also increased the apoptotic rate of NSCs as demonstrated by the increased expression of early apoptotic markers such as caspase-3, compared to control group (p<0.05). Furthermore, There was a statistically significant increase in homocysteine concentration during folate deficiency in NSCs (p<0.05). These data suggest that folate affects the cell proliferation, apoptosis and homocysteine generation in NSC cells.

[Effects of folic acid, vitamin B(6) and vitamin B(12) on learning and memory function in cerebral ischemia rats].

OBJECTIVE: To investigate the effects of folic acid, vitamin B(6) and B(12) on plasma homocysteine and on learning and memory functions in focal cerebral ischemia rats. METHODS: Sprague-Dawley rats were randomly divided into four groups. They were sham operation group (Sham OP), middle cerebral artery occlusion model group (MCAO), MCAO + folic acid group (MCAO + FA) and MCAO + compound vitamin (folate, vitamin B(6) and B(12)) group (MCAO + CV). Plasma homocysteine was measured before and after supplementation and after ischemia. RESULTS: The level of plasma homocysteine in MCAO + FA and MCAO + CV groups were significantly lower than those in Sham OP and MCAO groups after supplementation and ischemia (6.92 +/- 1.04) micromol/L and (5.49 +/- 1.00) micromol/L vs (9.33 +/- 1.11) micromol/L, (10.90 +/- 2.03 micromol/L), P < 0.05. While in MCAO + CV group was lower than that in MCAO + FA group (5.49 +/- 1.00) micromol/L vs (6.92 +/- 1.04) micromol/L, P < 0.05. The neurological deficit scores and shock times in Y-type maze of MCAO + FA and MCAO + CV groups were lower than those in MCAO group (1.75 +/- 0.46 and 1.38 +/- 0.52 vs 2.62 +/- 0.52; 123.50 +/- 39.77 and 86.25 +/- 21.39 vs 173.25 +/- 46.32, P < 0.05). The correct times of MCAO + CV group in Y-type maze was higher than that in MCAO group (3.75 +/- 0.42 vs 2.12 +/- 0.45, P < 0.05). CONCLUSION: Folic acid intake could not only reduce plasma homocysteine concentration but also promote the recovery of the learning and memory functions of rats with cerebral ischemia. The effects of folic acid combined with vitamin B(6) and vitamin B(12) on cerebral ischemia rats was better than that of single folate.

[Induction of aryl hydrocarbon receptor and CYP1A1 mRNA by 2,3,7,8-tetrachlorodibenzo-p-dioxin in rat liver].

OBJECTIVE: To explore the toxic mechanism of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by studying the induction of cytochrome P4501A1 (CYP1A1) and aryl hydrocarbon receptor (AHR) mRNA in liver of TCDD-treated SD rats. METHODS: Thirty female SD rats were randomly divided into control group and 5 exposure groups, every group had 5 rats. The animals were treated i.p. with 0.01, 0.1, 1, 10, 50 microg TCDD/kg BW. AHR and CYP1A1 mRNA expression were analyzed by RT-PCR after 24 h. RESULTS: The contents of AHR and CYP1A1 mRNA were increased in all exposure groups except the 0.01 microg TCDD/kg BW group. AHR mRNA content was significantly increased in 50 microg TCDD/kg BW group (P<0.05); CYP1A1 mRNA contents were significantly increased in all exposure groups (P<0.05) but not 0.01 microg TCDD/kg BW group. There were dose-response relationship between TCDD doses and AHR, CYP1A1 gene expression. CONCLUSION: Both AHR and CYP1A1 gene in liver of TCDD-treated SD rats can be induced 24 h after exposure and CYP1A1 gene is more inducible than AHR gene.