GPR126, also known as ADGRG6, is one of the most deeply studied aGPCRs. Initially, GPR126 was thought to be a receptor associated with muscle development and was primarily expressed in the muscular and skeletal systems. With the deepening of research, it was found that GPR126 is expressed in multiple mammalian tissues and organs, and is involved in many biological processes such as embryonic development, nervous system development, and extracellular matrix interactions. Compared with other aGPCRs proteins, GPR126 has a longer N-terminal domain, which can bind to ligands one-to-one and one-to-many. Its N-terminus contains five domains, a CUB (complement C1r/C1s, Uegf, Bmp1) domain, a PTX (Pentraxin) domain, a SEA (Sperm protein, Enterokinase, and Agrin) domain, a hormone binding (HormR) domain, and a conserved GAIN domain. The GAIN domain has a self-shearing function, which is essential for the maturation, stability, transport and function of aGPCRs. Different SEA domains constitute different GPR126 isomers, which can regulate the activation and closure of downstream signaling pathways through conformational changes. GPR126 has a typical aGPCRs seven-transmembrane helical structure, which can be coupled to Gs and Gi, causing cAMP to up- or down-regulation, mediating transmembrane signaling and participating in the regulation of cell proliferation, differentiation and migration. GPR126 is activated in a tethered-stalk peptide agonism or orthosteric agonism, which is mainly manifested by self-proteolysis or conformational changes in the GAIN domain, which mediates the rapid activation or closure of downstream pathways by tethered agonists. In addition to the tethered short stem peptide activation mode, GPR126 also has another allosteric agonism or tunable agonism mode, which is specifically expressed as the GAIN domain does not have self-shearing function in the physiological state, NTF and CTF always maintain the binding state, and the NTF binds to the ligand to cause conformational changes of the receptor, which somehow transmits signals to the GAIN domain in a spatial structure. The GAIN domain can cause the 7TM domain to produce an activated or inhibited signal for signal transduction, For example, type IV collagen interacts with the CUB and PTX domains of GPR126 to activate GPR126 downstream signal transduction. GPR126 has homology of 51.6%-86.9% among different species, with 10 conserved regions between different species, which can be traced back to the oldest metazoans as well as unicellular animals.In terms of diseases, GPR126 dysfunction involves the pathological process of bone, myelin, embryo and other related diseases, and is also closely related to the occurrence and development of malignant tumors such as breast cancer and colon cancer. However, the biological function of GPR126 in various diseases and its potential as a therapeutic target still needs further research. This paper focuses on the structure, interspecies differences and conservatism, signal transduction and biological functions of GPR126, which provides ideas and references for future research on GPR126.

Objective: The effect on fat infiltration (FI) of paraspinal muscles in degenerative lumbar spinal diseases has been demonstrated except for spinopelvic parameters. The present study is to identify the effect of spinopelvic parameters on FI of paraspinal muscle (PSM) and psoas major muscle (PMM) in patients with degenerative lumbar spondylolisthesis. Methods: A single-center, retrospective cross-sectional study of 160 patients with degenerative lumbar spondylolisthesis (DLS) and lumbar stenosis (LSS) who had lateral full-spine x-ray and lumbar spine magnetic resonance imaging was conducted. PSM and PMM FIs were defined as the ratio of fat to its muscle cross-sectional area. The FIs were compared among patients with different pelvic tilt (PT) and pelvic incidence (PI), respectively. Results: The PSM FI correlated significantly with pelvic parameters in DLS patients, but not in LSS patients. The PSM FI in pelvic retroversion (PT > 25°) was 0.54 ± 0.13, which was significantly higher in DLS patients than in normal pelvis (0.41 ± 0.14) and pelvic anteversion (PT < 5°) (0.34 ± 0.12). The PSM FI of DLS patients with large PI ( > 60°) was 0.50 ± 0.13, which was higher than those with small ( < 45°) and normal PI (0.37 ± 0.11 and 0.36 ± 0.13). However, the PSM FI of LSS patients didn’t change significantly with PT or PI. Moreover, the PMM FI was about 0.10–0.15, which was significantly lower than the PSM FI, and changed with PT and PI in a similar way of PSM FI with much less in magnitude. Conclusion FI of the PSMs increased with greater pelvic retroversion or larger pelvic incidence in DLS patients, but not in LSS patients.

Objective:To prepare an affinity-based radionuclide therapeutic drug targeting human epidermal growth factor receptor 2 (HER2), named 177Lu-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-HER2-BCH, and preliminarily evaluate its biodistribution, therapeutic efficacy, and safety in HER2-positive tumor models, in order to explore its feasibility as a radiopharmaceutical for treatment of HER2-positive tumor. Methods:177Lu labeling was accomplished by using a hydrochloric acid-sodium acetate buffer system. The radiochemical purity and in vitro stability of the labeled products were analyzed by radio high performance liquid chromatography. Biodistribution, 177Lu-DOTA-HER2-BCH radionuclide targeting therapy, and trastuzumab therapy were performed in the HER2-positive NCI-N87 tumor-bearing mice. Repeated measures analysis of variance and Bonferroni method were utilized to analyze data. Results:177Lu-DOTA-HER2-BCH was obtained, with the radiolabeling yield >80%, radiochemical purity >98%, and good in vitro stability. Biodistribution data showed that 177Lu-DOTA-HER2-BCH was well targeted, with high tumor uptake and high retention. The tumor uptake values at 4, 24, 72 and 96 h post-injection were (11.93±0.46), (8.65±0.40), (5.89±0.69) and (3.26±0.36) percentage activity of injection dose per gram of tissue (%ID/g), respectively. In the treatment experiment, 177Lu-DOTA-HER2-BCH significantly inhibited tumor growth. On the 3rd day, the tumor volume of mice treated with 177Lu-DOTA-HER2-BCH was significantly smaller than that of the control group (mean difference 146.97 mm 3;F=4.02, P=0.016 (Bonferroni correction method), and then differences of tumor volume between the 2 groups increased with time. The differences of tumor volume between 177Lu-DOTA-HER2-BCH and trastuzumab treatment groups were not statistically significant throughout the treatment process ( F values: 0.05-61.21, all P>0.017(Bonferroni correction method)). At the end of treatment, no histological abnormality was seen in all organs of the mice. Conclusion:177Lu-DOTA-HER2-BCH radionuclide therapy demonstrates good tumor growth inhibition in HER2-positive tumor-bearing mice, which is expected to be an alternative treatment for HER2-positive tumors.

Objective: The effect on fat infiltration (FI) of paraspinal muscles in degenerative lumbar spinal diseases has been demonstrated except for spinopelvic parameters. The present study is to identify the effect of spinopelvic parameters on FI of paraspinal muscle (PSM) and psoas major muscle (PMM) in patients with degenerative lumbar spondylolisthesis. Methods: A single-center, retrospective cross-sectional study of 160 patients with degenerative lumbar spondylolisthesis (DLS) and lumbar stenosis (LSS) who had lateral full-spine x-ray and lumbar spine magnetic resonance imaging was conducted. PSM and PMM FIs were defined as the ratio of fat to its muscle cross-sectional area. The FIs were compared among patients with different pelvic tilt (PT) and pelvic incidence (PI), respectively. Results: The PSM FI correlated significantly with pelvic parameters in DLS patients, but not in LSS patients. The PSM FI in pelvic retroversion (PT > 25°) was 0.54 ± 0.13, which was significantly higher in DLS patients than in normal pelvis (0.41 ± 0.14) and pelvic anteversion (PT < 5°) (0.34 ± 0.12). The PSM FI of DLS patients with large PI ( > 60°) was 0.50 ± 0.13, which was higher than those with small ( < 45°) and normal PI (0.37 ± 0.11 and 0.36 ± 0.13). However, the PSM FI of LSS patients didn’t change significantly with PT or PI. Moreover, the PMM FI was about 0.10–0.15, which was significantly lower than the PSM FI, and changed with PT and PI in a similar way of PSM FI with much less in magnitude. Conclusion FI of the PSMs increased with greater pelvic retroversion or larger pelvic incidence in DLS patients, but not in LSS patients.

Objective: The effect on fat infiltration (FI) of paraspinal muscles in degenerative lumbar spinal diseases has been demonstrated except for spinopelvic parameters. The present study is to identify the effect of spinopelvic parameters on FI of paraspinal muscle (PSM) and psoas major muscle (PMM) in patients with degenerative lumbar spondylolisthesis. Methods: A single-center, retrospective cross-sectional study of 160 patients with degenerative lumbar spondylolisthesis (DLS) and lumbar stenosis (LSS) who had lateral full-spine x-ray and lumbar spine magnetic resonance imaging was conducted. PSM and PMM FIs were defined as the ratio of fat to its muscle cross-sectional area. The FIs were compared among patients with different pelvic tilt (PT) and pelvic incidence (PI), respectively. Results: The PSM FI correlated significantly with pelvic parameters in DLS patients, but not in LSS patients. The PSM FI in pelvic retroversion (PT > 25°) was 0.54 ± 0.13, which was significantly higher in DLS patients than in normal pelvis (0.41 ± 0.14) and pelvic anteversion (PT < 5°) (0.34 ± 0.12). The PSM FI of DLS patients with large PI ( > 60°) was 0.50 ± 0.13, which was higher than those with small ( < 45°) and normal PI (0.37 ± 0.11 and 0.36 ± 0.13). However, the PSM FI of LSS patients didn’t change significantly with PT or PI. Moreover, the PMM FI was about 0.10–0.15, which was significantly lower than the PSM FI, and changed with PT and PI in a similar way of PSM FI with much less in magnitude. Conclusion FI of the PSMs increased with greater pelvic retroversion or larger pelvic incidence in DLS patients, but not in LSS patients.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To analyze the clinical and serological typing characteristics of invasive Haemophilus influ-enzae(Hin)infection in children.Methods Clinical data of 34 children with invasive Hin infection admitted to Children's Hospital of Shanxi from 2015 to 2021 were analyzed retrospectively.According to clinical diagnosis,they were divided into meningitis infection group and non-meningitis infection group.General data,symptoms,signs,laboratory serological indicators,and Hin serum typing characteristics of children,as well as differences in inflammatory factor level between the two groups were analyzed.Results Among the 34 patients,22 were males and 12 were females,with a male to female ratio of 1.83∶1.Children aged ≤36 months accounted for 82.35％.The levels of procalcitonin(PCT)(23.71[4.10,77.80])ng/mL and C-reactive protein(CRP)(200.00[164.55,200.00])mg/L in children in the meningitis infection group were higher than those in the non-meningitis group(1.08[0.49,6.00]ng/mL,69.46[48.09,125.63]mg/L,respectively),with statistically significant differences(both P＜0.05).The platelet(PLT)count in the non-meningitis group([312.56±186.81]× 109/L)was higher than that in the meningitis group([183.28±165.67]× 109/L),with statistically significant difference(P＜0.05).There was no statistically significant difference in white blood cell(WBC)count and neutrophil(NEUT)percentage between two groups(both P＞0.05).Among the isolated Hin strains,27,2,and 2 strains were type b(Hib),e and f,respectively;3 strains were not typed;serotype a,c and d strains were not found.There was no statistically significant difference in the distribution of typeable Hin strains between the two groups(x2=0.25,P＞0.05).There was no statistically significant difference in the constituent rate of typeable Hin strains between male and fe-male children(67.74％vs 32.26％,x2=1.42,P＞0.05).Conclusion The majority of invasive Hin infection cases are children under 3 years old,and the predominant strain is type b.CRP and PCT levels of infected children in-creased significantly,while PLT is significantly lower than that of non-infected children,which has certain clinical diagnostic value and can provide effective support for early classified diagnosis and anti-infection treatment of inva-sive infectious diseases combined with other clinical testing items.

Objective To study the clinical characteristics and bacterial antimicrobial susceptibility testing results of patients with clinically isolated Ralstonia pickettii(R.pickettii),and provide basis for the rational use of antimi-crobial agents.Methods Inpatients with R.pickettii infection who were treated at the Tianjin First Central Hospi-tal from January 2014 to December 2023 were analyzed retrospectively.Clinical characteristics and antimicrobial sus-ceptibility testing results were analyzed.Results A total of 80 strains of Ralstonia spp.were isolated over 10-year period,including 42(52.5％)non-repetitive strains of R.pickettii.Among 42 R.pickettii strains,64.3％were isolated from male patients.The strains isolated from sputum,catheter,blood,throat swabs,and drainage fluid specimens accounted for 38.1％,28.6％,19.0％,4.8％,and 2.4％,respectively.The clinical distribution of R.pickettii was highest in the intensive care unit(ICU),with a proportion of 52.4％.The number of infected patients first increased and then decreased with the years,followed by a slight fluctuation.There was no statistically signifi-cant difference in the number of infected patients in each department over the years(P＞0.05).R.pickettii had higher susceptibility rates to doxycycline,levofloxacin,ciprofloxacin,and minocycline,susceptibility rates were 78.3％-90.9％,but was completely resistant to compound sulfamethoxazole and cefazolin(100％),it also had higher resistance rates to aztreonam,colistin,cefotetan,tobramycin,amikacin,ceftazidime,and gentamicin(80.0％-97.4％).There was no statistically significant difference in the resistance rates to 21 antimicrobial agents among different years(all P＞0.05).Conclusion R.pickettii is mainly from ICU,and the majority of the infected population are adult males.Most strains are isolated from sputum and catheter.R.pickettii presents multidrug re-sistance.Attention should be paid to the changes in the resistance rates of antimicrobial agents,strengthen the dy-namic monitoring of bacterial resistance and guide the rational selection of antimicrobial agents in clinic,implement early and effective treatment to improve the prognosis of the patients.

Objective To explore the independent risk factors for central line-associated bloodstream infection(CLABSI),provide basis for developing intervention measures for infection prevention and control as well as con-ducting targeted treatment.Methods Patients who were diagnosed with CLABSI in a hospital from January 2019 to December 2023 were recruited retrospectively and defined as the infection group.According to 1:4 propensity score matching method,patients who received central venous catheter(CVC)without infection were taken as the control group.With whether CLABSI occurred as the dependent variable,the possible risk factors of the matched two groups as the independent variables,logistic regression analysis was conducted,and independent risk factors for pa-tients developing CLABSI were explored.Results A total of 42 patients in the CLABSI group and 168 patients in the non-CLABSI group were matched.Multivariate logistic regression analysis showed that high score of acute physiology and chronic health evaluation(APACHE)Ⅱ(OR=1.217,95％CI[1.094-1.357],P＜0.001),long duration of central venous catheterization(OR=1.273,95％CI[1.157-1.400],P＜0.001),and femoral venous catheterization(OR=6.846,95％CI[1.511-31.014],P=0.013)were independent risk factors for CLABSI.A total of 118 strains of pathogens were isolated from 42 CLABSI patients,with Gram-negative bacteria being the ma-jority(n=56).Conclusion High score of APACHE Ⅱ,long duration of central venous catheterization,and femo-ral venous catheterization are independent risk factors for CLABSI.The main pathogens are Gram-negative bacilli.Strict prevention and control measures for CLABSI should be implemented to reduce the risk of infection.

From the perspective of the physiological basis of liver and kidney sharing the common source in traditional Chinese medicine(TCM),and by integrating the theory of kidney dominating bone,liver dominating tendon,and meridian sinew of TCM as well as the bone resorption and collapse theory,and non-uniform settlement theory and lower-limb musculoskeletal bowstring structure theory of modern orthopedics,the pathogenesis of osteonecrosis of the femoral head(ONFH)under the system of non-uniform settlement during bone resorption and multidimensional composite bowstring working in coordination with the theory of liver-kidney and muscle-bone was explored.The key to the TCM pathogenesis of ONFH lies in the deficiency of the liver and kidney,and then the imbalance of kidney yin-yang leads to the disruption of the dynamic balance of bone formation and bone resorption mediated by osteoblasts-osteoclasts,which manifests as the elevated level of bone metabolism and the enhancement of focal bone resorption in the femoral head,and then leads to the necrosis and collapse of the femoral head.It is considered that the kidney dominates bone,liver dominates tendon,and the tendon and bone together constitute the muscle-bone-joint dynamic and static system of the hip joint.The appearance of collapse destroys the originally balanced muscle-bone-joint system.Moreover,the failure of liver blood in the nourishment of muscles and tendons further exacerbates the imbalance of the soft tissues around the hip joint,accelerates the collapse of the muscle-bone-joint dynamic and static system,speeds up the process of femoral head collapse,and ultimately results in irreversible outcomes.Based on the above pathogenesis,the systematic integrative treatment of ONFH should be based on the TCM holistic concept,focuses on the focal improvement of internal and external blood circulation of the femoral head by various approaches,so as to rebuild the coordination of joint function.Moreover,attention should be paid to the physical constitution of the patients,and therapy of tonifying the kidney and regulating the liver can be used to restore the balance between osteogenesis and osteoblastogenesis,and to reconstruct the muscle-bone-joint system,so as to effectively delay or even prevent the occurrence of ONFH.