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

Background::Hepatitis B poses a heavy burden for children in China, however, the national studies on the distributional characteristics and health care costs of children with severe hepatitis B is still lacking. This study aimed to analyze the disease characteristics, health economic effects, and medical cost for children with severe hepatitis B in China.Methods::Based on patient information in the Hospital Quality Monitoring System, cases with severe hepatitis B were divided into four groups according to age, and the etiology and symptoms of each group were quantified. The cost of hospitalization was calculated for cases with different disease processes, and severity of disease. The spatial aggregation of cases and the relationship with health economic factors were analyzed by Moran’s I analysis. Results::The total number of children discharged with hepatitis B from January 2016 to April 2022 was 1603, with an average age of 10.5 years. Liver failure cases accounted for 43.48% (697/1603) of total cases and cirrhosis cases accounted for 11.23% (180/1603). According to the grouping of disease progression, there were 1292 cases without associated complications, and the median hospitalization cost was $818.12. According to the spatial analysis, the aggregation of cases was statistically significant at the prefectural and provincial levels in 2019, 2020, and 2021 (all P <0.05). The number of severe cases was negatively correlated with gross domestic product (Moran’s I <0) and percentage of urban population (Moran’s I <0), and positively correlated with the number of pediatric beds per million population (Moran’s I >0). Conclusion::The number of severe hepatitis B cases is low in areas with high gross domestic product levels and high urban population ratios, and health care costs have been declining over the years.

Background::Hepatitis B poses a heavy burden for children in China, however, the national studies on the distributional characteristics and health care costs of children with severe hepatitis B is still lacking. This study aimed to analyze the disease characteristics, health economic effects, and medical cost for children with severe hepatitis B in China.Methods::Based on patient information in the Hospital Quality Monitoring System, cases with severe hepatitis B were divided into four groups according to age, and the etiology and symptoms of each group were quantified. The cost of hospitalization was calculated for cases with different disease processes, and severity of disease. The spatial aggregation of cases and the relationship with health economic factors were analyzed by Moran’s I analysis. Results::The total number of children discharged with hepatitis B from January 2016 to April 2022 was 1603, with an average age of 10.5 years. Liver failure cases accounted for 43.48% (697/1603) of total cases and cirrhosis cases accounted for 11.23% (180/1603). According to the grouping of disease progression, there were 1292 cases without associated complications, and the median hospitalization cost was $818.12. According to the spatial analysis, the aggregation of cases was statistically significant at the prefectural and provincial levels in 2019, 2020, and 2021 (all P <0.05). The number of severe cases was negatively correlated with gross domestic product (Moran’s I <0) and percentage of urban population (Moran’s I <0), and positively correlated with the number of pediatric beds per million population (Moran’s I >0). Conclusion::The number of severe hepatitis B cases is low in areas with high gross domestic product levels and high urban population ratios, and health care costs have been declining over the years.

In order to explore the effect of peptidoglycan hydrolase on the viable cell counts of Bacillus amyloliquefaciens and the yield of alkaline protease, five peptidoglycan hydrolase genes (lytC, lytD, lytE, lytF and lytG) of B. amyloliquefaciens TCCC111018 were knocked out individually. The viable cell counts of the bacteria and their alkaline protease activities before and after gene deletion were determined. The viable cell counts of the knockout mutants BA ΔlytC and BA ΔlytE achieved 1.67×10⁶ CFU/mL and 1.44×10⁶ CFU/mL respectively after cultivation for 60 h, which were 32.5% and 14.3% higher than that of the control strain BA Δupp. Their alkaline protease activities reached 20 264 U/mL and 17 265 U/mL, respectively, which were 43.1% and 27.3% higher than that of the control strain. The results showed that deleting some of the peptidoglycan hydrolase genes effectively maintained the viable cell counts of bacteria and increased the activity of extracellular enzymes, which may provide a new idea for optimization of the microbial host for production of industrial enzymes.
Bacillus amyloliquefaciens/genetics* ; Bacterial Proteins ; Cell Count ; Endopeptidases/genetics* ; N-Acetylmuramoyl-L-alanine Amidase/genetics*

Objective:To analyze the clinical characteristics and efficacy of drug treatment in children with inflammatory bowel disease (IBD) at different ages of onset.Methods:The clinical data of 87 children with IBD admitted to Department of Gastroenterology in Children′s Hospital, Capital Institute of Pediatrics from January 2009 to December 2018 were collected. The patients were divided into four groups according to the age of onset: 0 -<2 years old group (36 cases), 2 -<6 years old group (10 cases), 6 -<10 years old group (12 cases) and 10 -<18 years old group (29 cases). The clinical manifestations, laboratory examination, endoscopic findings, pathologic and genetic changes, and treatment were compared among different age groups with chi-square test or Fisher′s exact text.Results:(1) A total of 87 patients were diagnosed with IBD, including 50 Crohn′s disease (CD) (57%), 25 ulcerative colitis (UC) (29%) and 12 unclassified inflammatory bowel disease (IBD-U) (14%). (2) Patients with fever accounted for 78% (28/36) and 8/10 in the 0 -<2 years old group and 2 -<6 years old group, respectively. Patients with abdominal pain and perianal diseases accounted for 6% (2/36) and 47% (17/36) in the 0 -<2 years old group, and their proportions were significantly different among the four groups (χ 2=8.369, 40.317 and 13.130, all P<0.05). (3) Leukocytosis, thrombocytosis and anemia were more common in the 0-<2 years old group, seen in 72% (26/36), 31% (11/36) and 81% (29/36), respectively. There were significant differences in the changes of complete blood count among the four groups (χ 2=21.919, 8.095 and 11.520, all P<0.05). (4) Colonic involvement accounted for 85% (17/20) in the 0 -<2 years old CD patients. While in the CD patients over 6 years old, 61% (14/23) had inflammation of ileum and colon, with a significant difference compared to that in patients under 6 years old (19% (5/27) , χ 2=9.455, P=0.003). Also, the location of bowel inflammation among the four groups were significantly different (χ 2=21.120, P<0.01). (5) Noncaseating granulomas were found in 15 (30%) CD patients, and crypt abscess was found in 11 (44%) UC patients. (6) Among the 24 patients whose genes were analyzed by high throughput sequencing, 12 had pathogenic single gene mutation. (7) There were 25 patients treated with total enteral nutrition. Among the 25 patients treated with thalidomide, 20 (80%) had clinical remission or partial remission. Among the 19 CD patients treated with infliximab (IFX), 14 had clinical remission at the 6 th week of treatment, and the proportion of remission maintenance at the 30 th week of treatment was 12/14. (8) The rate of clinical remission or partial remission was 64% (23/36) in the 0 -<2 years old group, 8/10 in the 2 -<6 years old group, 11/12 in the 6 -<10 years old group, and 83% (24/29) in the 10 -<18 years old group. Conclusions:The proportion of CD was higher than that of UC in this study. Infant onset inflammatory bowel disease was more likely to present with perianal lesions, and was usually associated with leukocytosis, thrombocytosis and anemia, and has high possibility of single gene mutation. IFX may be effective in treating CD.

Objective: To analyze the clinical and genotypic characteristics of infantile inflammatory bowel disease (IBD). Methods: The age of onset, family history, clinical manifestations, and treatment effect were retrospectively analyzed in 39 infants (male 23 cases, female 16 cases) with IBD who were admitted to the Department of Gastroenterology in Children′s Hospital, Capital Institute of Pediatrics from January 2007 to December 2017. Next generation sequencing (NGS) based on target gene panel was used for gene analysis in 17 patients. Results: The median age of onset was 0.5 (0.5, 1.0) month. The most common clinical symptoms included diarrhea (39, 100%), malnutrition (38, 97%), hematochezia (34, 87%), fever (25, 64%), and perianal diseases (24, 61%). Four children had associated family history. Among the 17 patients whose gene was analyzed, 10 were found to have the pathogenic gene variation, within whom 7 had interleukin-10 receptor α subunit (IL-10RA) mutation, 2 had CYBB heterozygous mutation, 1 had interleukin-10 receptor β subunit (IL-10RB) mutation. The therapeutic medicine included mesalazine, steroids, and thalidomide. Eighteen children (46%) reached clinical remission (10 cases) or partial remission (8 cases). Conclusions The incidence of single gene mutation in infants with IBD is high, with IL-10RA mutation as the most common. Refractory diarrhea and malnutrition may indicate infantile IBD.

Objective To analyze the clinical and genotypic characteristics of infantile inflammatory bowel disease (IBD). Methods The age of onset, family history, clinical manifestations, and treatment effect were retrospectively analyzed in 39 infants (male 23 cases, female 16 cases) with IBD who were admitted to the Department of Gastroenterology in Children′s Hospital, Capital Institute of Pediatrics from January 2007 to December 2017. Next generation sequencing (NGS) based on target gene panel was used for gene analysis in 17 patients. Results The median age of onset was 0.5 (0.5, 1.0) month. The most common clinical symptoms included diarrhea (39, 100%), malnutrition (38, 97%), hematochezia (34, 87%), fever (25, 64%), and perianal diseases (24, 61%). Four children had associated family history. Among the 17 patients whose gene was analyzed, 10 were found to have the pathogenic gene variation, within whom 7 had interleukin‐10 receptor α subunit (IL‐10RA) mutation, 2 had CYBB heterozygous mutation, 1 had interleukin‐10 receptor β subunit (IL‐10RB) mutation. The therapeutic medicine included mesalazine, steroids, and thalidomide. Eighteen children (46%) reached clinical remission (10 cases) or partial remission (8 cases). Conclusions The incidence of single gene mutation in infants with IBD is high, with IL‐10RA mutation as the most common. Refractory diarrhea and malnutrition may indicate infantile IBD.

Hydroxy amino acids, constituents of chiral pharmaceutical intermediates or precursors, have a variety of unique functions in the research fields of biotechnology and molecular biology, i.e. antifungal, antibacterial, antiviral and anticancer properties. Biosynthesis of hydroxy amino acids is preferred because of its high specificity and selectivity. The hydroxylation of hydrophobic amino acids is catalyzed by hydroxylase, which belongs to the mononuclear non-heme Fe(Ⅱ)/α-ketoglutarate-dependent dioxygenases (Fe/αKGDs). Fe/αKGDs utilize an (Fe(Ⅳ)=O) intermediate to activate diverse oxidative transformations with key biological roles in the process of catalytic reaction. Here, we review the physiological properties and synthesis of hydroxy amino acids, especially for the 4-HIL and hydroxyproline. The catalytic mechanism of Fe/αKGDs is elucidated, and the applications of hydroxy amino acids in industrial engineering are also discussed.

Objective: To analyze the clinical features and interleukin-10 receptor gene mutations in six infants with very early onset inflammatory bowel disease (VEO-IBD). Methods: Four girls and two boys with VEO-IBD admitted to Children's Hospital Affiliated to Capital Institute of Pediatrics from June 2016 to September 2017 were reviewed. The clinical data including general condition, clinical symptoms, laboratory tests, and colonoscopy and pathological results were collected and analyzed. Interleukin-10 receptor α subunit (IL-10RA) gene was examined in all patients. Results: Persistent diarrhea and fever were the most common symptoms and were found within 1 month after birth in all 6 patients. Anemia, oral ulcer or perianal lesions and growth retardation were common concomitant symptoms. All patients had colonoscopy examination and the results showed multiple ulcers affecting the colon with biopsies revealing acute and chronic inflammation. Three patients were found to have cryptitis and crypt abscesses. Gene sequencing revealed IL-10RA gene mutations in all six patients, including 3 cases with homozygous mutations (one with c.537G>A and two with c.301C>T) and 3 heterozygous mutations (paternal c.301C>T in all cases; maternal c.299T>G, c.350G>A and c.537G>A, respectively) . After conventional treatment, one got clinical and pathological improvement according to colonoscopy, three improved clinically, one worsened and died, and one died of septic shock secondary to intestinal perforation. Conclusions VEO-IBD is associated with IL-10RA mutation, usually with severe intestinal symptoms and significant extra-intestinal symptoms, as well as varied responses to conventional treatment. In our study, c.301C>T and c.537G>A are the most common mutations.

Objective To study the changes of activities of phase Ⅰ and Ⅱ drug-metabolic enzymes in the spleen of rats with spleen-kidney yang deficiency syndrome.Methods The rat model of spleen-kidney yang deficiency syndrome was established by gastric gavage of Radix et Rhizoma Rhei decoction combined with injection of hydrocortisone for 17 continuous days.And then we detected the activities of 6 kinds of phase Ⅰ drug-metabolic enzymes of CYP2C19,CYP2D6,CYP2C9,CYP1A2,CYP2C8,CYP3A4,and 4 kinds of phase Ⅱ drugmetabolic enzymes of phenol sulfotransferase (PST),uridine diphosphate glucuronosyl transferase 1 (UGT1),glutathione transferase (GST),estrogen sulfotransferase (SULT1E1) in the spleen.Results Compared with the normal control group,the activities of PST,UGT1,GST and SULT1E1 in the model group were significantly decreased (P ＜ 0.05 or P ＜ 0.01),and the activity of CYP1A2 was significantly increased (P ＜ 0.01),while CYP2C19,CYP2D6,CYP2C8,CYP3A4,CYP2C9 enzymes showed no obvious changes(P ＞ 0.05).Conclusion The activities of splenic drug-metabolic enzymes,in particular the phase Ⅱ enzymes,are significantly varied under the state of spleen-kidney yang deficiency.