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.

Hypoxia inducible factor-3α promotes osteosarcoma progression by activating KDM3A-mediated demethylation of SOX9.

Hypoxia/oxygen-sensing signally is closely associated with many tumor progressions, including osteosarcoma (OS). Previous research principally focused on the function of hypoxia-inducible factor (HIF)-1α and HIF-2α as the major hypoxia-associated transcription factors in OS, however, the role of HIF-3α has not been investigated. Our study found that HIF-3α was upregulated in OS tissues and cell lines. HIF-3α overexpression facilitated cell proliferation and invasion, and inhibited apoptosis, whereas HIF-3α knockdown showed the opposite results. Chromatin immunoprecipitation analysis revealed that lysine demethylase 3A (KDM3A) expression was transcriptionally activated by HIF-3α under hypoxia, and KDM3A occupied the SRY-box transcription factor 9 (SOX9) gene promoter region through H3 lysine 9 dimethylation (H3K9me2). Additionally, rescue results revealed that KDM3A or SOX9 overexpression reversed the effects of HIF-3α silence on cell functions. The Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway inhibitor cucurbitacin I suppressed the promotive effects of HIF-3α overexpression on cell proliferation, invasion and TAK2/STAT3 pathway. Finally, OS cell line MG-63 transfected with HIF-3α short hairpin RNA (HIF-3α shRNA) were subcutaneously injected into nude mice, and the results found that HIF-3α knockdown significantly inhibited the xenograft tumor growth of OS in vivo. In conclusion, this study reveals that HIF-3α promotes OS progression in vitro and in vivo by activating KDM3A-mediated SOX9 promoter demethylation, which may provide a potential therapeutic mechanism for OS.

Raman spectroscopic study of frustrated ferroelectric phase in hydroxyl salts Co2(OH)3Br/Co2(OD)3Br.

We report on an investigation of the temperature-dependent ordering of the hydrogen/deuterium atoms in geometrically frustrated magnets Co2(OH)3Br and its deuterated Co2(OD)3Br, to shed light on the origin of the newly-identified ferroelectricity using Raman spectroscopy. Significant changes in the Raman frequencies and line-widths of the Raman-active modes were observed below ∼260 K in Co2(OD)3Br and ∼240 K in Co2(OH)3Br, respectively, the analysis of which revealed strong spin-phonon couplings in this system. Further, for Co2(OD)3Br, six new phonon bands appeared below around 260 K, with the corresponding intensities obeying a power-law equationI∝1-T/Tc2ßwhereinTc= 260 K, suggesting that an ordering process occurred below ∼260 K. The ordering process subsequently affected the local structure and brought out the reported ferroelectric phase, which is considered as frustrated. Meanwhile, in Co2(OH)3Br, only one new band was observed below ∼240 K, followed by two 'softened' modes correlated to the [OH] sub-lattice below ∼185 K, wherein an incomplete ordering was suggested. The present work reveals a new multiferroic system combining geometrically frustrated magnetism and deuterium ordering-type ferroelectricity.

Structural insights into the substrate specificity of a glycoside hydrolase family 5 lichenase from Caldicellulosiruptor sp. F32.

Glycoside hydrolase (GH) family 5 is one of the largest GH families with various GH activities including lichenase, but the structural basis of the GH5 lichenase activity is still unknown. A novel thermostable lichenase F32EG5 belonging to GH5 was identified from an extremely thermophilic bacterium Caldicellulosiruptor sp. F32. F32EG5 is a bi-functional cellulose and a lichenan-degrading enzyme, and exhibited a high activity on ß-1,3-1,4-glucan but side activity on cellulose. Thin-layer chromatography and NMR analyses indicated that F32EG5 cleaved the ß-1,4 linkage or the ß-1,3 linkage while a 4-O-substitued glucose residue linked to a glucose residue through a ß-1,3 linkage, which is completely different from extensively studied GH16 lichenase that catalyses strict endo-hydrolysis of the ß-1,4-glycosidic linkage adjacent to a 3-O-substitued glucose residue in the mixed-linked ß-glucans. The crystal structure of F32EG5 was determined to 2.8 Šresolution, and the crystal structure of the complex of F32EG5 E193Q mutant and cellotetraose was determined to 1.7 Šresolution, which revealed that the exit subsites of substrate-binding sites contribute to both thermostability and substrate specificity of F32EG5. The sugar chain showed a sharp bend in the complex structure, suggesting that a substrate cleft fitting to the bent sugar chains in lichenan is a common feature of GH5 lichenases. The mechanism of thermostability and substrate selectivity of F32EG5 was further demonstrated by molecular dynamics simulation and site-directed mutagenesis. These results provide biochemical and structural insights into thermostability and substrate selectivity of GH5 lichenases, which have potential in industrial processes.

Characterization of a thermostable endo-1,3(4)-ß-glucanase from Caldicellulosiruptor sp. strain F32 and its application for yeast lysis.

ß-1,3-Glucans, important structural components of cell wall or nutritional components of the endosperm, are extensively found in bacteria, fungi, yeast, algae, and plants. The structural complexity of ß-1,3-glucans implies that the enzymatic depolymerization of polysaccharides needs combined activities of distinct enzymes. In this study, Lam16A-GH, the catalytic module of a putative glycoside hydrolase (GH) family 16 laminarinase/lichenase from thermophilic bacterium Caldicellulosiruptor sp. F32, was purified and characterized through heterologous expression in Escherichia coli. Lam16A-GH can hydrolyze both ß-1,3-glucan (laminarin) and ß-1,3-1,4-glucan (barley ß-glucan) revealed by analysis of the products of polysaccharide degradation using thin-layer chromatography (TLC). The time required for the loss of 50 % of its activity is 45 h under the optimal condition of 75 °C and pH 6.5. Oligosaccharides degradation assay indicated that Lam16A-GH can catalyze endo-hydrolysis of the ß-1,4 glycosidic linkage adjacent to a 3-O-substituted glucosyl residue in the mixed linked ß-glucans, as well as the ß-1,3 linkage. The survival rate of Saccharomyces cerevisiae cells depends on the addition of Lam16A-GH, and the cytoplasm protein was released from the apparently deconstructed yeast cells. These results indicate that the bi-functional thermostable Lam16A-GH exhibits unique enzymatic properties and potential for yeast lysis.

Depiction of carbohydrate-active enzyme diversity in Caldicellulosiruptor sp. F32 at the genome level reveals insights into distinct polysaccharide degradation features.

Thermophilic bacterium Caldicellulosiruptor sp. F32 can utilize cellulose-, hemicellulose-containing biomass, including unpretreated wheat straw. We have conducted a bioinformatics analysis of the carbohydrate-active enzyme (CAZyme) in the genome of Caldicellulosiruptor sp. F32, which reveals a broad substrate range of the strain. Among 2285 predicted open reading frames (ORFs), 73 (3.2%) CAZyme encoding genes, including 44 glycoside hydrolases (GHs) distributing in 22 GH families, 6 carbohydrate esterases (CEs), 3 polysaccharide lyases (PLs), 21 glycosyl transferases (GTs), and 25 carbohydrate-binding modules (CBMs) were found. An in-depth bioinformatics analysis of CAZyme families that target cellulose, hemicellulose, chitin, pectin, starch, and ß-1,3-1,4-glucan degradation were performed to highlight specialized polysaccharide degrading abilities of strain F32. A great number of orthologous multimodular CAZymes of Caldicellulosiruptor sp. F32 were found in other strains of genus Caldicellulosiruptor. While, a portion of the CAZymes of Caldicellulosiruptor sp. F32 showed sequence identity with proteins from strains of genus Clostridium. A thermostable ß-glucosidase BlgA synergistically facilitated the enzymatic degradation of Avicel by endo-1,4-ß-glucanase CelB, which indicated that the synchronous action of synergism between CAZymes enhanced the lignocellulose degradation by Caldicellulosiruptor sp. F32.

Distinct roles for carbohydrate-binding modules of glycoside hydrolase 10 (GH10) and GH11 xylanases from Caldicellulosiruptor sp. strain F32 in thermostability and catalytic efficiency.

Xylanases are crucial for lignocellulosic biomass deconstruction and generally contain noncatalytic carbohydrate-binding modules (CBMs) accessing recalcitrant polymers. Understanding how multimodular enzymes assemble can benefit protein engineering by aiming at accommodating various environmental conditions. Two multimodular xylanases, XynA and XynB, which belong to glycoside hydrolase families 11 (GH11) and GH10, respectively, have been identified from Caldicellulosiruptor sp. strain F32. In this study, both xylanases and their truncated mutants were overexpressed in Escherichia coli, purified, and characterized. GH11 XynATM1 lacking CBM exhibited a considerable improvement in specific activity (215.8 U nmol(-1) versus 94.7 U nmol(-1)) and thermal stability (half-life of 48 h versus 5.5 h at 75°C) compared with those of XynA. However, GH10 XynB showed higher enzyme activity and thermostability than its truncated mutant without CBM. Site-directed mutagenesis of N-terminal amino acids resulted in a mutant, XynATM1-M, with 50% residual activity improvement at 75°C for 48 h, revealing that the disordered region influenced protein thermostability negatively. The thermal stability of both xylanases and their truncated mutants were consistent with their melting temperature (Tm), which was determined by using differential scanning calorimetry. Through homology modeling and cross-linking analysis, we demonstrated that for XynB, the resistance against thermoinactivation generally was enhanced through improving both domain properties and interdomain interactions, whereas for XynA, no interdomain interactions were observed. Optimized intramolecular interactions can accelerate thermostability, which provided microbes a powerful evolutionary strategy to assemble catalysts that are adapted to various ecological conditions.

Clinical study of treatment switching from premixed insulin to basal insulin combined with oral hypoglycemic drugs in patients with type 2 diabetes.

AIM: Premixed insulin regimens are commonly used for the treatment of patients with type-2 diabetes mellitus (T2DM). However, limited data are available regarding next-step therapy options in cases where premixed insulin fails to provide adequate glycemic control. This 20-week observational study of everyday clinical practice evaluated the efficacy, safety and treatment satisfaction of insulin glargine plus oral anti-diabetic drugs (OADs) in T2DM patients previously treated with premixed insulin. METHODS: In this open-label, single-arm, 20-week study, 70 subjects with T2DM inadequately controlled with premixed insulin were switched to insulin glargine plus OADs. Changes in glycaemic control, incidence of hypoglycaemia, treatment satisfaction using the Diabetes Treatment Satisfaction Questionnaire (DTSQ), serum superoxide dismutase (SOD), and serum 8-iso-prostaglandin (8-iso-PG) were evaluated at the start and the end of the study. RESULTS: Over the 20 week treatment period, mean (±SD) HbA1c levels decreased from 8.28 ± 1.24% to 6.83 ± 1.09%, mean (±SD) FBG levels decreased from 7.64 ± 1.36 mmol/L to 5.57 ± 1.21 mmol/L, and 2 h PBG levels decreased from 12.07 ± 1.17 mmol/L to 8.94 ± 1.56 mmol/L, all P < 0.001. A total of 3 symptomatic hypoglycemic episodes were reported. No significant reductions in body weight were observed. The mean daily dose of insulin decreased by 14 U between week 0 (30.20 ± 9.93 U) and week 20 (16.38 ± 5.15 U). The total treatment satisfaction score showed a significant increase from study baseline to end point. Significant increases in SOD(90.00 ± 16.62 to 108.81 ± 27.02 u/ml, P < 0.01) and reductions in 8-iso-PG(2.15 ± 0.61 to 1.64 ± 0.42 pg/ml, P < 0.05) were observed between the start and end of the observation period. There were significant differences in baseline HbA1c, duration of diabetes, and baseline postprandial C-peptide between the A1c ≤ 6.5% group and the A1c > 7.0% group [HbA1c: 7.25% ± 1.02% vs. 9.32% ± 1.23%; duration: 7.84 ± 1.02 vs. 13.96 ± 1.35 years; postprandial C-peptide: 4.83 ± 2.11 vs 2.54 ± 0.87 nmol/L, all P < 0.05]. CONCLUSIONS: The observational study shows that, in T2DM patients inadequately controlled with premixed insulin, switching therapy to glargine plus OADs is associated with significant improvements in glycaemic control and treatment satisfaction, and is with low incidence of hypoglycemia. Baseline postprandial C-peptide, HbA1c, and duration of diabetes are the key factors closely related to efficacy of this treatment regimen.

Raman spectroscopic study of the frustrated spin 1/2 antiferromagnet clinoatacamite.

Raman spectroscopy is a valuable and complementary tool for studying geometrically frustrated magnetic systems due to the intrinsic spin-phonon coupling. Here, we report on a Raman spectroscopic study of the geometrically frustrated spin 1/2 antiferromagnet microcrystalline clinoatacamite Cu2(OH)3Cl, focusing on the anomalous transition into the intermediate phase at T(c1) = 18.1 K. By measuring the temperature-dependent (295-4 K) full spectral profiles and main representative modes in spectral regions from 4000 to 95 cm(-1), we observed probable signatures of successive magnetic transitions near T(c1) = 18 K and T(c2) = 6.4 K in the Raman band frequencies and peak widths of the representative modes. Further, we observed a pronounced Raman spectroscopy background featuring a broad continuum at all temperatures. A quantitative analysis reveals that spin fluctuations may exist on a picosecond time scale in the intermediate phase. The short time scale falls out of the µSR time window; therefore, in the intermediate phase, the µSR study as reported in (2005 Phys. Rev. Lett. 95 057201) apparently only probed the local field of the ordered spins but overlooked the quickly fluctuating ones. This is likely to give a reasonable explanation of the fact that only a small entropy release occurs at T(c1) = 18 K although a long-range order is formed.

[Mid-infrared and Raman spectral analysis of geometrically frustrated natural atacamite].

At room temperature, the mid-infrared spectra of geometrically frustrated natural atacamite (hydroxyl copper chloride, beta-Cu2(OH)3Cl) in the range of 4 000-400 cm(-1) were measured by FTIR spectrometers, and meanwhile its Raman spectrum in the range of 4 000-95 cm(-1) was obtained by Jobin Yvon LabRAM HR800 Raman spectrometer. According to its crystal structure parameters, the authors confirmed the characteristic peaks of sample 4 000-2 500-1 000 cm(-1) in the functional group region and 1 000-550-200-95 cm(-1) in the fingerprint region, and also explored its microscopic origin Five distinct regions were assigned: the hydroxyl stretching vibration v(O-H) determined by the overall environment around the hydroxyl group; the overtones generated by the sum or multiplication of fundamental frequencies of hydroxyl bending vibration; the hydroxyl bending vibration modes delta(O-H) of the combination of delta(Cu-O-H) and delta(O-H...HCl); the vibration modes of strongly bonded planar CuO4 units; the vibration modes of weakly bonded linear-triatomic chain Cl-Cu-O/Cl. The bands were assigned in accordance with its crystal structure parameters, which is more reasonable to establish the relationship between its molecular structure and its respective spectral properties.