S-methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from S-methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from Schizosaccharomyces pombe (spfmo) was heterologously expressed in Escherichia coli BL21(DE3) and the enzymatic properties of the expressed protein were analyzed. The optimum catalytic conditions of the recombinant SpFMO were 30 ℃ and pH 8.0, under which the enzyme activity reached 72.77 U/g. An appropriate amount of Mg²⁺ improved the enzyme activity. The enzyme kinetic analysis showed that the K_m and k_cat/K_m of SpFMO on the substrate SMC were 23.89 μmol/L and 61.71 L/(min·mmol), respectively. Under the optimal reaction conditions, the yield of SMCO synthesized from SMC catalyzed by SpFMO was 12.31% within 9 h. This study provides reference for the enzymatic synthesis of SMCO.
Schizosaccharomyces/genetics* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Cysteine/biosynthesis* ; Mixed Function Oxygenases/metabolism* ; Schizosaccharomyces pombe Proteins/metabolism* ; Oxygenases/metabolism* ; Kinetics

At present, the major public health challenges caused by novel coronavirus infection have gradually subside. However, a large number of people are still suffering from long-novel coronavirus syndrome or post-novel coronavirus syndrome. The clinical manifestations of long coronavirus syndrome are related to multiple systems, such as respiratory, circulatory, nervous, digestive and musculoskeletal systems, with various long-term persistent symptoms after novel coronavirus infection. At the same time, the infection of the novel coronavirus is an important cause of frailty and sarcopenia in the elderly population. However, at present, the scholars have not paid enough attention to the skeletal muscle weakness caused by the novel coronavirus. Therefore, this paper focuses on the long-novel coronavirus syndrome and sarcopenia to explore the pathological mechanism of skeletal muscle attenuation caused by the SARS-CoV-2 mediated "cytokine storm", mitochondrial damage, hypoxia state and other links, so as to raise the attention of clinical and academic researchers and improve the clinical strategy of frailty and sarcopenia after novel coronavirus infection.

ObjectivesTo compare the clinical efficacy and complications of anatomic locking titanium plate （hereinafter referred to as “titanium plate screw”） and intramedullary nail in the treatment of distal tibial fractures.Methods From September 2019 to September 2021， 32 patients diagnosed with AO-A fracture of distal tibia at Sun Yat-sen Memorial Hospital of Sun Yat-sen University were included in this study. Of these， 15 cases were treated with titanium plate screws and 17 cases were treated with intramedullary nails. General surgical indexes， fracture healing time and postoperative operation were compared between the two groups.ResultsAll patients were followed up for 10 to 20 months， with an average of 12 months. The operative time and intraoperative fluoroscopy times of intramedullary nail group were longer than those of titanium plate screw group， but the preoperative waiting time and hospitalization days was less or were fewer than those of titanium plate screw group， the difference was statistically significant （P < 0.05）. There was no significant difference in fracture healing time between the two groups （P> 0.05）. At 6 weeks after operation， VAS scores in both groups were lower than those before operation， with statistically significant difference （P<0.05）. There was no significant difference in VAS scores between the intramedullary nail group and the titanium plate screw group （P> 0.05）. AOFAS scores 6 months after surgery， ankle joint motion and complication rate 1 year after surgery in intramedullary screw group were better than those in titanium plate screw group， and the differences were statistically significant （P< 0.05）. There was no significant difference in AOFAS scores between the two groups at 1 year after operation （P> 0.05）.ConclusionTitanium plate screw and intramedullary nail are both effective methods for the treatment of distal tibial AO-A fracture， and there is no significant difference in long-term clinical efficacy. Intramedullary nail has fewer soft tissue complications， less impact on ankle motion， faster recovery and higher safety， while titanium plate screw has a higher probability of postoperative soft tissue infection. We suggest that in clinical work， preoperative evaluation of patients should be done well. Under the premise of grasping the indications， intramedullary nail has fewer complications and certain advantages.

Uncovering the risk factors of pulmonary hypertension and its mechanisms is crucial for the prevention and treatment of the disease.In the current study,we showed that experimental periodontitis,which was established by ligation of molars followed by orally smearing subgingival plaques from patients with periodontitis,exacerbated hypoxia-induced pulmonary hypertension in mice.Mechanistically,periodontitis dysregulated the pulmonary microbiota by promoting ectopic colonization and enrichment of oral bacteria in the lungs,contributing to pulmonary infiltration of interferon gamma positive(IFNγ+)T cells and aggravating the progression of pulmonary hypertension.In addition,we identified Prevotella zoogleoformans as the critical periodontitis-associated bacterium driving the exacerbation of pulmonary hypertension by periodontitis,and the exacerbation was potently ameliorated by both cervical lymph node excision and IFNγ neutralizing antibodies.Our study suggests a proof of concept that the combined prevention and treatment of periodontitis and pulmonary hypertension are necessary.

AIM: To investigate the effect of scleral-fixated capsular tension ring(SFCTR)combined with phacoemulsification and intraocular lens(IOL)implantation in the treatment of traumatic lens subluxation.METHODS: A total of 14 patients(14 eyes)who underwent SFCTR combined with phacoemulsification and IOL implantation for traumatic lens subluxation from December 2018 to February 2023 were selected. Visual acuity, intraocular pressure, anterior segment photography, and ultrasound biomicroscopy(UBM)were examined during postoperative follow-up. The location of IOL and postoperative complications were recorded.RESULTS: SFCTRs and IOLs were successfully implanted in all patients. The mean postoperative follow-up was 1.92±1.36 a. At the last follow-up, the uncorrected distance visual acuity(UDVA; 0.20±0.18 LogMAR)and corrected distance visual acuity(CDVA; 0.16±0.17 LogMAR)were significantly improved compared with the UDVA(1.13±0.56 LogMAR)preoperatively(P<0.01). The intraocular pressure(17.64±3.67 mmHg)was lower than that before the operation(22.00±9.92 mmHg; P<0.05). During the follow-up, the slit-lamp examination showed that the IOL was in the middle of the pouch. UBM examination showed that the CTR and IOL were located in the pouch, and the distance between the equatorial part of the pouch and the ciliary process was equal in all directions.CONCLUSION: The SFCTR combined with phacoemulsification and IOL implantation is an efficient and minimally invasive method in the treatment of traumatic lens subluxation.

Objective To compare and analyze the differences in CD8+naive,effector,memory,exhausted and regulatory T cells in order to investigate the impact of gender on the differentiation fate of CD8+T cells in the context of type 1 diabetes (T1D)based on female and male non-obese diabetic (NOD)mice and healthy Institute for Cancer Research (ICR)mice.Methods The frequencies and phenotypes of CD8+T cell differentiation subsets including naive T cells (TN),central memory T cells (TCM),effector T cells(TEFF),effector precursor T cells (TEP),exhausted T cells (TEX),precursor exhausted T cells (TPEX)and regulatory T cells (Tregs)in the spleen,pancreatic draining lymph nodes (pLN)and pancreas infiltrating lymphocytes (PIL)of male and female NOD mice were detected by flow cytometry.Results The frequencies of IFN-γ+,CD107a+and CCL5+CD8+TEFF in pLN and PIL of female NOD mice were significantly higher than those of male NOD mice.However,the frequencies of CD8+TN,CD8+TCM,CD8+TEX,CD8+TPEX and CD122+CD8+Tregs subsets in the spleen were significantly decreased.While there were no significant differences in the above CD8+T cell subsets except CD8+Tregs between female and male ICR mice. Conclusion Androgen may inhibit the differentiation of memory T cells into effector T cells and promote the exhaustion of effector T cells,leading to the difference in morbidity between the male and female mice.

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the prenatal diagnosis of chromosomal mosaicisms. METHODS: A total of 775 pregnant women who had visited the Prenatal Diagnosis Center of Yancheng Maternal and Child Health Care Hospital from January 2018 to December 2020 were selected as study subjects. Chromosome karyotyping analysis and CMA were carried out for all women, and FISH was used to validate the suspected mosaicism cases. RESULTS: Among the 775 amniotic fluid samples, karyotyping has identified 13 mosaicism cases, which yielded a detection rate of 1.55%. Respectively, there were 4, 3, 4 and 2 cases for sex chromosome number mosaicisms, abnormal sex chromosome structure mosaicisms, abnormal autosomal number mosaicisms and abnormal autosomal structure mosaicisms. CMA has only detected only 6 of the 13 cases. Among 3 cases verified by FISH, 2 cases were consistent with the karyotyping and CMA results, and clearly showed low proportion mosaicism, and 1 case was consistent with the result of karyotyping but with a normal result by CMA. Eight pregnant women had chosen to terminate the pregnancy (5 with sex chromosome mosaicisms and 3 with autosomal mosaicisms). CONCLUSION For fetuses suspected for chromosomal mosaicisms, CMA, FISH and G-banding karyotyping should be combined to determine the type and proportion of mosaicisms more precisely in order to provide more information for genetic counseling.
Female ; Pregnancy ; Humans ; Mosaicism ; In Situ Hybridization, Fluorescence ; Chromosome Disorders/genetics* ; Prenatal Diagnosis/methods* ; Chromosome Aberrations ; Sex Chromosome Aberrations ; Microarray Analysis/methods* ; Chromosomes

OBJECTIVE: To explore the clinical and genetic characteristics of four patients with medium-chain acyl-CoA dehydrogenase deficiency (MCADD). METHODS: Four children who had presented at the Children's Hospital Affiliated to Zhengzhou University between August 2019 and August 2021 were selected as the study subjects. Clinical data of the children were collected. The children were subjected to whole exome sequencing (WES). RESULTS: All of the four children were diagnosed with MCADD. Blood amino acid and ester acyl carnitine spectrum test showed that the concentration of octanoyl carnitine (C8) was significantly increased. The main clinical manifestations included poor mental response (3 cases), intermittent diarrhea with abdominal pain (1 case), vomiting (1 case), increased transaminase (3 cases), and metabolic acidosis (2 cases). Five variants were identified by genetic testing, among which c.341A>G (p.Y114C) was unreported previously. Three were missense variants, one was frameshift variant and one was splicing variant. CONCLUSION The clinical heterogeneity of MCADD is obvious, and the severity of the disease may vary. WES can assist with the diagnosis. Delineation of the clinical symptoms and genetic characteristics of the disease can facilitate early diagnosis and treatment of the disease.
Child ; Humans ; Acyl-CoA Dehydrogenase/genetics* ; Carnitine ; Genetic Testing ; Lipid Metabolism, Inborn Errors/genetics* ; Neonatal Screening

OBJECTIVE: To explore the clinical features and genetic basis of a child with Galactosemia. METHODS: A child who had presented at the Children's Hospital Affiliated to Zhengzhou University on November 20, 2019 was selected as the study subject. Clinical data of the child was collected. Whole exome sequencing was carried out for the child. Candidate variants were validated by Sanger sequencing. RESULTS: Clinical manifestations of the child have included anemia, feeding difficulty, jaundice, hypomyotonia, abnormal liver function and coagulation abnormality. Tandem mass spectrometry showed increased citrulline, methionine, ornithine and tyrosine. Urine organic acid analysis showed increased phenyllactic acid, 4-hydroxyphenylacetic acid, 4-hydroxyphenyllactic acid, 4-hydroxyphenylpyruvate and N-acetyltyrosine. Genetic testing revealed that the child has harbored compound heterozygous variants of the GALT gene, namely c.627T>A (p.Y209*) and c.370G>C (p.G124R), which were respectively inherited from her healthy parents. Among these, c.627T>A (p.Y209*) was known as a likely pathogenic variant, while c.370G>C (p. G124R) was unreported previously and also predicted as a likely pathogenic variant(PM1+PM2_Supporting+PP3_Moderate+PPR). CONCLUSION Above discovery has expanded the spectrum of the GALT gene variants underlying Galactosemia. Patients with thrombocytopenia, feeding difficulties, jaundice, abnormal liver function and coagulation abnormality without obvious causes should be analyzed by screening of metabolic diseases in combination with genetic testing.
Child ; Female ; Humans ; Galactosemias/genetics* ; Genetic Testing ; Health Status ; Methionine ; Muscle Hypotonia ; Mutation

Objective:To investigate the clinical characteristics, genetic characteristics and diagnosis of spinocerebellar ataxia type 2 (SCA2) patients with childhood onset.Methods:The clinical data of a SCA2 pedigree who diagnosed at Neurogenetic Metabolic Disease Clinic of Children′s Hospital Affiliated to Zhengzhou University in July 2019 were collected, and the reported cases of childhood-onset SCA2 were reviewed. The CAG repeat of ATXN2 gene was detected by polymerase chain reaction, capillary gel electrophoresis and Sanger sequencing techniques.Results:A total of 9 people in 4 generations of the family were affected, showing an autosomal dominant inheritance. The proband was a 3 years and 4 months old boy, who showed abnormal symptoms at 9 months which manifested as developmental retardation. At 1 year old, he developed progressive regression which represented neither to be amused, recognize others, stand and walk alone, nor had language development. Meanwhile, he had difficulty swallowing, long-term constipation, and a history of convulsions. His sister and mother were not yet sick. His grandmother could not walk, had slurred speech accompanied by nystagmus, and magnetic resonance imaging showed cerebellar atrophy. His granduncles and grandaunts had unstable walking and dysarthria. His great-grandfather required wheelchair to walk. This pedigree showed an autosomal dominant inheritance. One of the ATXN2 gene alleles of the proband, his sister, mother and grandmother all showed abnormal amplification with 99, 55, 44, and 43 times respectively and no inserting CAA sequence. A total of 14 literatures reported 20 cases of childhood-onset SCA2 patients who were genetically diagnosed. The majorities had onset in infancy, and few can develop into school age. The main clinical manifestations were developmental delay, dystonia or insufficiency, myoclonus or infantile spasms, motor retardation, abnormal eye movement, retinitis pigmentosa and dysphagia, while the classic cerebellar syndrome was only partially present. Abnormal rhythm was found on electroencephalogram, cerebellar atrophy on magnetic resonance imaging or CT of the head.Conclusions:This case is the youngest genetically-confirmed SCA2 patient reported in China. Reported patients usually have onset in infancy with excessive repeat sequence expansion. Their clinical characteristics are different from the classic patients and could only be diagnosed by dynamic mutation detection.