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.

ObjectiveTo evaluate the efficacy and safety of Rongjin Tongbi decoction on sciatica caused by lumbar intervertebral disc herniation with liver and kidney deficiency type based on a randomized controlled study. MethodFrom January 2019 to July 2022， 90 patients in the department of Traditional Chinese medicine（TCM） of Beijing Jishuitan Hospital who met the inclusion criteria were selected and divided into two groups according to the random number table， with 45 patients in each group. During the study， 19 cases dropped out， with 41 cases included in the final observation group and 30 cases in the control group. The observation group was given Rongjin Tongbi decoction orally， and the control group was given Loxoprofen Sodium Tablets orally for 28 days. The differences in the visual analog scale （VAS） scores， the Japanese Orthopaedic Association （JOA） scores， activities of daily living （ADL） assessments， TCM clinical symptoms， subjective symptoms， and clinical signs scores between two groups before and after treatment were observed. Liver and kidney functions and gastrointestinal adverse reactions were detected for safety evaluation. ResultBefore treatment， there was no statistically significant difference in scores between the observation group and the control group. After treatment， the absolute values of the differences in VAS and ADL scores in the observation group were higher than those in the control group （P<0.05）. There was no statistically significant difference in the absolute value of the difference in JOA scores between two groups. The absolute value of the difference in TCM clinical symptom scores in the observation group was higher than that in the control group （P<0.01）. There was no statistically significant difference in the absolute values of the differences in subjective symptom and clinical sign scores between two groups. The levels of liver and kidney function indicators in both groups before and after the experiment were normal， and there was no significant difference in gastrointestinal reactions. ConclusionRongjin Tongbi decoction can significantly improve the symptoms of sciatica patients caused by lumbar intervertebral disc herniation with liver and kidney deficiency type. After treatment， the patients exhibited significant improvements in pain， activity and other aspects， and it is proven to be safe and reliable， which is conducive to the recovery of physical function.

Objective To analyze the differential expressed genes(DEGs)in the lung tissues of rat model of high altitude pulmonary edema(HAPE)by using microarray analysis in order to provide new clues for molecular mechanism of HAPE.Methods Healthy male SD rats(8 weeks old,weighing 200±20 g)were randomized into normoxia control(NC)group,lipopolysaccharide(LPS)group,hypoxia group and hypoxia+low-dose LPS(HL)group.The rats of the LPS group and HL group were injected with 0.1 mL 0.05％LPS per 100 g body weight,and those of the NC group and the hypoxia group were administered with an equivalent volume of normal saline.The rats of the hypoxia group and the HL group were housed in a hypobaric chamber simulating an altitude of 5 000 m,and those of the NC group and the LPS group were raised simultaneously outside of the chamber.The wet/dry mass ratio(WDR)of lung tissue and total protein content in bronchoalveolar lavage fluid(BALF)were measured,and the histopathological changes of lung tissue was observed using HE staining.The total RNA was extracted from the lung tissues,and the mRNA expression profile was obtained with Affymetrix microarray followed by Gene Ontology(GO)analysis and Kyoto encyclopedia of genes and genomes(KEGG)pathway analysis with Metascape(http://metascape.org).Results The rats of the HL group showed significant congestion,edema,and widened alveolar septa.Compared with the NC group,the HL group had significantly increased lung WDR(P＜0.01)and total protein content in BALF(P＜0.05).Gene expression analysis revealed that there were 79 genes up-regulated and 59 genes down-regulated in the hypoxia group,473 genes up-regulated and 695 genes down-regulated in the LPS group,and especially,669 genes up-regulated and 1 253 genes down-regulated in the HL group.GO and KEGG pathway analyses revealed that the upregulated genes in the HL group were mainly enriched in biological processes,such as cytokine mediated signaling pathways,response to IL-1,regulation of inflammatory response,as well as signaling pathways,including cytokine-cytokine receptor interactions,TNF,NF-κB,IL-17,complement and coagulation cascades,etc.The down-regulated genes were mainly enriched in biological processes,such as extracellular matrix organization,regulation of endothelial cell migration,cell substrate adhesion,as well as signaling pathways,such as focal adhesion,Wnt,cGMP-PKG,PI3K-Akt,Rap1,etc.The mRNA expression of NF-κB,TNF-α,IL-1βand IL-6 was significantly up-regulated in the lung tissue of the HL group(P＜0.01).Conclusion Hypoxia+low-dose LPS is an effective procedure to establish a reliable model for HAPE in rats.Hypoxia can significantly aggravate LPS-induced inflammation and immune response,enhance the expression of inflammatory mediators,and thus promote the pathogenesis of HAPE.

Objective:To introduce a reliable and easy method of philtrum crest and philtrum repairing in secondary repair of cleft lip.Methods:Lift the upper lip flap after removing the scar on upper lip. Then the superficial orbicularis oris muscle was carefully separated, which formed the abnormal muscular eminence in the affected side after the first cleft lip repair. The pedicle of the orbicularis oris muscle the reconstructing philtrum crest. The lingual orbicularis oris muscle flap was lifted and curled from outside. The superficialorbicularis oris muscle was cut in philtrum longitudinally and turned outward. The two evertedorbicularisoris muscle flaps were sutured on both sides and fixed them on the reconstructing philtrum crest. The exposed deep orbicularis oris muscle in philtrum was sutured with the upper dermis, which formed the prominentphiltrum crest and deeper philtrum.Results:We reviewed the hospital records of patients from July 2008 to November 2021. In total, 201 patients were included in this study. All of these patients underwent the reconstruction of philtrum crest and philtrum with orbicularis oris muscle intertangling and philtrum plasty in secondary cleft lip repairing. During the treatment, the patients had no complications such as infection, hematoma and flap necrosis.198 patients were observed from 1 months to 36 months (7.8 months on average). All of them improved in different degrees in early postoperative period. Most reconstructed philtrum crest was raised and basically symmetrical with the contralateral side in shape. The philtrum was clear and the scar was not obvious. The reconstructed philtrum crest would decrease with time. 91.7% (90/98) patients were satisfied with the postoperative effects after three months.Conclusions:The method of reconstruction of philtrum crest and philtrum with orbicularis oris muscle intertangling and philtrum plasty in secondary cleft lip repairing is safe and effective. The long term postoperative effect is stable with high satisfaction as well. As a result, this method can be used as the philtrum crest and philtrum correction scheme for secondary cleft lip repairing.

The adenosine 5'-triphosphate (ATP)-binding cassette (ABC) transporter, IrtAB, plays a vital role in the replication and viability of Mycobacterium tuberculosis (Mtb), where its function is to import iron-loaded siderophores. Unusually, it adopts the canonical type IV exporter fold. Herein, we report the structure of unliganded Mtb IrtAB and its structure in complex with ATP, ADP, or ATP analogue (AMP-PNP) at resolutions ranging from 2.8 to 3.5 Å. The structure of IrtAB bound ATP-Mg2+ shows a "head-to-tail" dimer of nucleotide-binding domains (NBDs), a closed amphipathic cavity within the transmembrane domains (TMDs), and a metal ion liganded to three histidine residues of IrtA in the cavity. Cryo-electron microscopy (Cryo-EM) structures and ATP hydrolysis assays show that the NBD of IrtA has a higher affinity for nucleotides and increased ATPase activity compared with IrtB. Moreover, the metal ion located in the TM region of IrtA is critical for the stabilization of the conformation of IrtAB during the transport cycle. This study provides a structural basis to explain the ATP-driven conformational changes that occur in IrtAB.
Siderophores/metabolism* ; Iron/metabolism* ; Mycobacterium tuberculosis/metabolism* ; Cryoelectron Microscopy ; Adenosine Triphosphate/metabolism* ; ATP-Binding Cassette Transporters

Objective:To establish a candidate reference procedure for the enumeration of cell particles in urine and applied to the multi-center performance evaluation of an automated urine formed elements analyzer.Methods:According to the standardized mannual microscopic examination of fresh non-centrifuged urine samples and the recommended reference method for enumeration of cell particles in urine published by ISLH, we established a candidate reference procedure for the enumeration of cell particles in urine. From four class A tertiary hospitals′ clinical laboratories, three rigorous trained technicians per hospital tested the same specimen respectively using the reference procedure. Each specimen was repeatedly counted 5 times, obtaining the quantitative results of cell particles were obtained in urine. Four hospitals used the established candidate reference measurement procedure and the automated urine formed elements analyzer to detect 40 to 60 urine specimens from September 2020 to January 2021, and evaluate the established reference method, meanwhile evaluate the accuracy and consistency of the each count from automated urinalysis analyzer.Results:Using the candidate reference measurement procedures, the coefficient of variation of results derived from three trained technicians per hospital was less than 6.98% (red blood cells), 6.99% (white blood cells), 13.94% (epithelial cells) and met the quality requirements. The performance evaluation results of automated urine formed elements analyzer showed that the accuracy of red blood cells, white blood cells and epithelial cells met the requirements (bias≤4.98%) and was well consistent with the reference measurement procedure ( R2≥0.989). Conclusions:A candidate reference measurement procedure for the enumeration of urine cell particles was successfully established with satisfactory precision and accuracy. This procedure was applied to multicenter performance evaluation of an automated urine formed elements analyzer with good accuracy and consistency.

Objective: To investigate the potential improvement of sample quality by automatic pre-analysis sample checking system, comparing to visual inspection for coagulation tests routinely. Methods: Thirty samples with hemolysis, Icteric and lipemia in different levels were prepared and issued to 13 technicians for visual check, to evaluate the consistency individually. 2 949 blood samples with order for coagulation test were collected in Beijing Chaoyang Hospital in April and May 2018, the quality of all samples was evaluated by both visual check and automatic sample quality checking system before analysis, performance of two measurements detecting hemolysis, lipid, icteric or clot was compared. Results: Significant differences were found in visual check among operators. The Kappa coefficients in three randomly selected groups were 0.32, 0.26 and 0.38 respectively, indicating that the consistency of visual check was poor. Among all investigated samples, 3 samples with unacceptable interference were detected visually, including 2 samples with hemolysis and another one with lipemia. On the other hand, 19 unqualified samples were identified by automatic checking system. Five types of interference of unqualified samples were detected as icteric (26.32%,5/19), clot (21.05%,4/19) hemolysis (5.26%,1/19),lipemia (36.84%, 7/19), and hemolysis with lipemia (10.53%,2/19) respectively by automatic checking system. But one case of hemolysis sample rejected by visual check was not rejected by automatic sample quality checking system.7 samples were merely affected on D-dimer by lipemia, which level did not influence the results of prothrombin time(PT) and activated partial thromboplastin time (APTT). Notably, other two samples were interfered with not only tests of PT, APTT and fibrinogen by hemolysis, but also D-dimer by the considerable level of lipemia, which showed the superiority of test-specific quality checking features. Conclusions The automatic pre-analysis sample quality checking system can improve the detection rate of unqualified samples and improve the efficiency of routine, helping realization of total quality management.

In order to explore the effect and its mechanism of paeoniflorin on PD-L1, a PD-L1 high expression cell model was established in interferon gamma(IFN-γ)-induced HepG2 cells. The cytotoxicity of paeoniflorin was detected by MTT assay. Flow cytometry, ELISA and RT-PCR were performed to detect protein and mRNA levels of PD-L1 regulated by paeoniflorin. In HepG2 cells and Jurkat T cell co-culture system, the expression of IL-2 was detected by ELISA. Besides, T cell proliferation was evaluated by CCK-8 method, and the protein expression levels of PD-L1, JAK and STAT3 after drug treatment were determined by Western blot. These results indicated that paeoniflorin could significantly down-regulate the levels of PD-L1 protein and mRNA. In addition, it increased the number of T cells and the concentration of IL-2 in the co-culture system. Furthermore, paeoniflorin could significantly inhibit the protein expression of JAK and STAT3. Au the above experimental data indicated that paeoniflorin could down-regulate the expression of PD-L1, and its mechanism might be related to the JAK/STAT3 pathway.

The aim of this study was to synthesize and evaluate the necrosis avidity of MRI contrast agent based on rhein and linked by ether. The novel ligand 10-{［6-(1, 8-dihydroxyanthraquinone-3-carboxamido)ethoxyethyl］amino}carbonylmethyl-1, 4, 7, 10-tetraazacyclododecan-1, 4, 7-triacetic acid(DO3A-Ether-Rhein, E1)was synthesized by two steps of acylation and deprotection reaction. The paramagnetic gadolinium 10-{［6-(1, 8-dihydroxyanthraquinone-3-carboxamido)ethoxyethyl］amino}carbonylmethyl-1, 4, 7, 10-tetraazacyclododecan-1, 4, 7-triacetic acid(Gd-DO3A-Ether-Rhein, GdE1)was obtained by coordination of Gd3+ with the above ligand. We examined the necrotic avidity of GdE1 in human hepatocellular carcinoma HepG2 cell necrosis induced by hyperthermia in vitro and in rat model with muscular necrosis induced by microwave ablation in vivo by MRI. The MRI was implemented before administration of GdE1 and during 0-9 h after administration of GdE1(0. 1 mmol/kg), and Gd-DOTA(gadolinium 1, 4, 7, 10-tetraacetic acid-1, 4, 7, 10-tetraazacyclo dodecane)was used as control. The signal intensity of necrotic cells(4 369±70)was significantly higher than that of normal cells(2 555±84)(P< 0. 05). Similarly, the contrast ratio between necrotic and normal muscle at 3 h after administration of GdE1(2. 00±0. 12)was remarkblely higher than that at 0 h after administration of GdE1(1. 27±0. 03)(P< 0. 05). Therefore, GdE1 presents good necrosis affinity and has the potential to be used in the diagnosis of necrosis-related diseases.