Ornithine transcarbamylase(OTC)is a member of the transcarbamylase protein family,commonly found in the mitochondrial matrix of living organisms.It generally functions in a trimeric form and can catalyze the production of L-ornithine to L-citrulline.OTC is mainly expressed in the liver and intestines of mammals,playing an important role in the urea cycle and amino acid homeostasis.This article introduces the research progress of OTC genes,proteins,physiological functions,the impact of OTC deficiency on body health,and the diagnosis and treatment of OTC deficiency.

Objective To analyze the risk factors for chronic mountain sickness(CMS)in young male migrants living in high-altitude areas and to construct a diagnostic model and evaluate its diagnostic efficacy.Methods From June 10 to December 29,2023,a cross-sectional study was conducted on young male migrants subjected with convenience sampling who had been living in high-altitude areas(4 500～5 000 m)for 6 months or longer.Their demographic data were collected and blood samples were collected for laboratory test.According to the Qinghai Score for Chronic Mountain Sickness,they were divided into CMS group and non-CMS group.Then the participants were randomly divided into a training set and a test set in a ratio of 8∶2.Independent risk factors for CMS occurrence were screened out,through random forest variable importance ranking,univariate and multivariable logistic regression analysis,and a diagnostic model was constructed based on these factors.Receiver operating characteristic(ROC)curve analysis,calibration curve analysis,clinical decision curve analysis,and influence curve analysis were used to comprehensively evaluate the diagnostic performance of the model.Results According to the inclusion and exclusion criteria,308 out of 376 participants were finally subjected,and 17.53%of them were diagnosed with CMS.The major clinical symptoms of the CMS patients were dyspnea or palpitations(79.63%)and sleep disorders(85.19%).Further analysis revealed that creatine kinase-MB/creatine kinase(CK-MB/CK,OR=2.17,95%CI:1.43～3.28),high-altitude residence time(OR=2.44,95%CI:1.08～5.54),and body mass index(BMI,OR=1.62,95%CI:1.05～2.50)were 3 major independent risk factors for CMS.The area under the curve(AUC)value of the CMS diagnostic model in the training set and test set was 0.821(95%CI:0.756～0.886)and 0.821(95%CI:0.700～0.944),the specificity was 66.30%and 73.90%,the sensitivity was 89.50%and 81.20%,respectively,indicating good discrimination ability.Hosmer-Lemeshow goodness-of-fit test showed consistency between predicted results and actual observations(χ2=10.029,P=0.263;χ2=4.477,P=0.812).Clinical decision curve analysis demonstrated that within the threshold probability range from 0.1 to 0.7,the net benefit of the model exceeded both full intervention and no intervention strategies.The influence curve analysis showed high consistency between the model predictions and actual incidence when the threshold probability exceeded 0.4.These two analyses together confirmed the clinical application value of the model.Conclusion CK-MB/CK,high-altitude residence time and BMI are independent risk factors for CMS,and their diagnostic model helps identify potential individuals at risk for CMS.Early intervention can prevent the harm of CMS to the health of young men migrating to high-altitude areas.

N-glycosylation modification, one of the most common protein post-translational modifications, occurs in heat shock protein gp96. The purpose of this study is to investigate the effect of N-glycosylation modification on immunologic function of the recombinant gp96 using the mutant gp96 in N-glycosylation sites. Firstly, wild-type and mutant gp96 proteins were expressed by insect expression system and their glycosylation levels were detected. To determine the effect of N-glycosylation on gp96 antigen presentation function, the IFN-γ+ CD8+ T cells in gp96-immunized mice and secretion level of IFN-γ were examined by flow cytometry and ELISA. The ATPase activity of gp96 was further detected by the ATPase kit. Finally, the effect of N-glycosylation on adjuvant function of gp96 for influenza vaccine was investigated in immunized mice. It was found that total sugar content of mutant recombinant gp96 was reduced by 27.8%. Compared to the wild type recombinant gp96, mutations in N-glycosylation sites resulted in decreased antigen presentation ability and ATPase activity of gp96. Furthermore, influenza vaccine-specific T cell levels induced by mutant gp96 as adjuvant were dramatically reduced compared to those by wild type recombinant gp96. These results demonstrate that N-glycosylation modification is involved in regulation of ATPase activity and antigen presentation function of gp96, thereby affecting its adjuvant function. The results provide the technical bases for development of gp96- adjuvanted vaccines.
Adjuvants, Immunologic ; Animals ; CD8-Positive T-Lymphocytes/metabolism* ; Glycosylation ; Heat-Shock Proteins ; Influenza Vaccines ; Mice

Objective To investigate the levels of nutritional knowledge, attitude and dietary habits and its influential factors of the officers and soldiers in frontier forces to provide the theory basis for nutrition education.Methods Using self-designed nutritional knowledge-altitude-practice (KAP) questionnaires to survey 90 officers and soldiers who lived in plateau for at least 6 months. Questionnaires were handed out and handed over on the spot. According toMilitary Nutrition Survey and Evaluation Methods (GJB 1636A-2016), we measured the physical index of officers and soldiers, including height, weight and skin thickness of triceps. And we also evaluated body mass index (BMI) and upper arm muscle circumference.Results Nutrition knowledge, attitude and practice conditions of plateau forces were at the average, better and average levels respectively. Nutritional knowledge was significantly positively related to the practices (r=0.283,P=0.003), and was also significantly positively related to the age of the soldiers (r=0.228,P=0.04). Nutritional attitude was positively related to source of officers and soldiers (r=0.339,P=0.035), and nutritional practices were positively related to the upper arm muscle circumference (r=0.222,P=0.030). 65.6% of the officers and soldiers would like to know the knowledge about relationship between diet and disease. 25.6% of the officers and soldiers in the plateau were alcohol users.Conclusions Although the nutrition knowledge of plateau forces were poor, and the nutritional practices were influenced by nutritional knowledge, but the soldiers' attitude of changing unhealthy dietary habits was very positive. It is necessary to undertake the dietary nutrition education related to the high altitude nutrition among plateau forces to guild their nutritional practice scientifically.

Objective To investigate the dietary nutrition status of plateau frontier forces and to make recommendations on food and nutrients intake for plateau forces.Methods The dietary status of the plateau forces located at an altitude of 4600 m and 4030 m was investigated by weighing method.The dietary ration for soldiers, their daily dietary allowance and dietary balance index were used to evaluate their dietary patterns and nutrient intake.The concentrations of serum vitamin A and 25-OH vitamin D(25-OH VD) were detected by high performance liquid chromatography (HPLC).The arm muscle circumference and body fat rate of soldiers were evaluated by GJB 1636A-2016 and body composition related standard respectively.Results The intake of eggs, milk and plant oil of Unit A was sufficient, while the rest of the food intake did not reach the military standard;The intake of grain and plant oil of Unit B was sufficient,but the rest of the food intake was insufficient.The intake of protein,calcium,phosphonium,sodium,iron,selenium,iodine,copper,manganese,vitamin E and vitamin B3 of Unit A were adequate, but that of energy,potassium,zinc,magnesium,vitamin D,vitamin C,vitamin B1 and vitamin B2 was insufficient, and the intake of vitamin A,vitamin B6,vitamin B9 and vitamin B12 of Unit A was deficient.The intake of energy, protein,vitamin E,vitamin C,vitamin B1 and vitamin B3,and most of the minerals was adequate in Unit B, but vitamin B2 was insufficient.Furthermore, the intake of calcium,iodine,vitamin A,vitamin D and vitamin B was deficient.The proportion of nutrients which supply energy and the energy distribution of three meals in the two units were imperfect.The concentration of plasma vitamin A in both units was sufficient,but the concentration of plasma 25-OH VD was deficient.93.5% soldiers of unit A and 97.7% soldiers of unit B reached the standard of proper muscle circumference,80.6% soldiers of unit A and 70.5% soldiers of unit B had a low body fat rate.Conclusion The dietary structure of plateau border forces is not balanced.The intake of some foods and nutrients is insufficient so that nutritional education is badly needed to improve the dietary status of plateau forces.

Objective To explore the feasibility of the mixed- or single-application of etomidate and propofol during modified electroconvulsive therapy (MECT). Methods Ninety hospitalized schizophrenics undergoing MECT were randomly assigned to 3 groups which were respectively anesthetized with mixed liquor application of etomidate and propofol (group E-P), etomidate (E) or propofol (P). Charge delivered (CD), EEG seizure duration (ESD), postictal suppression index (PSI), seizure energy index (SEI) and seizure generalization index (SGI) were recorded. Mental status and memory levels were assessed with the Positive and Negative Syndrome Scale (PANSS) and Wechsler Memory Scale (WMS) before and after treatment. The adverse reactions were recorded. All data were analyzed with the software SPSS12.0. Results The ESD, PSI, SEI, SGI and WMS scores, and the minus score of PANSS were significantly higher (P < 0.05) and CD was lower (P < 0.05) in group E-P than those in group P. No significant alteration between group E-P and group E (P > 0.05). The adverse reactions such as nausea/vomiting and secretion increase in group E-P were lower than those in group E (P < 0.05). The injection pain of group E-P was lower than that of group P (P<0.05). Conclusion The mixed liquor of etomidate and propofol has an advantage over the single-application of the two drugs during MECT.