BACKGROUND:A large number of studies have confirmed that the therapeutic effectiveness of mesenchymal stem cell secretome is comparable to that of mesenchymal stem cells,but the mechanism of its action is still unclear. OBJECTIVE:To summarize the research progress of mesenchymal stem cell secretome in recent years,to investigate the molecular mechanism of its therapeutic effect,to analyze the current problems and to look forward to the future development. METHODS:The terms"exosomes,mesenchymal stem cells secrete,extracellular vesicles,mesenchymal stem cells,mechanism"were used as English search terms in the PubMed database.Articles that were not related to the research purpose of the article and duplicated articles were excluded.At the same time,we combined the method of literature tracking.Finally,109 articles that met the criteria were incuded for the review. RESULTS AND CONCLUSION:(1)The mesenchymal stem cell secretome promotes tissue repair and regeneration through delivering genetic material,immunomodulatory factors,growth factors,etc.to target cells,by activating anti-apoptotic,regulating angiogenesis,modulating fibrosis and pro-survival pathways in target cells.(2)The potential of mesenchymal stem cell secretome in disease therapy has also been confirmed.Numerous research results have shown that mesenchymal stem cell secretome can be used as a new cell-free treatment for inflammatory and degenerative diseases.(3)Mesenchymal stem cell secretome has been engineered to have more efficient therapeutic effects in recent years.However,due to the heterogeneity of the mesenchymal stem cell secretome and the complexity of its components,the exact mechanism of its therapeutic effect is still unclear.(4)At present,further research is needed to identify the key targets of mesenchymal stem cell secretome,and innovative specific and enhanced mesenchymal stem cell secretome should be developed by combining with engineering and genetic engineering technologies in the future.

BACKGROUND:Due to the complex physiological environment of the human body,a wide variety of simulated physiological fluids have been chosen for the current degradation experiments.Therefore,it is of great interest to analyze the degradation behavior of Mg-Zn-Ca alloys in different simulated body fluid environments. OBJECTIVE:To investigate the degradation process and property changes of Mg-Zn-Ca alloy in different simulated body fluids,and to clarify the influence of Ca content and simulated body fluid type on the alloy. METHODS:Mg-Zn-Ca alloys with calcium content of 0.2%,0.5%and 1%were prepared by melting extrusion molding process and were named Mg-Zn-0.2Ca,Mg-Zn-0.5Ca and Mg-Zn-1Ca alloys in turn,with Mg-Zn alloy as the control.The prepared alloys were placed into three simulated body liquids(physiological saline,PBS and Hank's solution),and the morphology,compositional changes,mass loss,pH value and mechanical properties were characterized and analyzed during the degradation. RESULTS AND CONCLUSION:(1)With the extension of degradation time,a large number of nanoscale lamellae and columnar structures were generated on the surface of the degraded alloy,and the main components were MgO and Mg(OH)2.The degradation rate of the four kinds of alloys in physiological saline was the fastest,and that in Hank's solution was the slowest.The degradation rate in physiological saline was as follows:Mg-Zn

Objective:To explore the clinical characteristics and genetic variants in three children with late-onset Multiple acyl-Coenzyme A dehydrogenase deficiency (MADD type Ⅲ).Methods:Clinical data of three children diagnosed with late-onset MADD at the Children′s Hospital Affiliated to Zhengzhou University between March 2020 and March 2022 were retrospectively analyzed. All children were subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. All children had received improved metabolic therapy and followed up for 1 ~ 3 years.Results:The children had included 2 males and 1 female, and aged from 2 months to 11 years and 7 months. Child 1 had intermittent vomiting, child 2 had weakness in lower limbs, while child 3 had no symptom except abnormal neonatal screening. Tandem mass spectrometry of the three children showed elevation of multiple acylcarnitines with short, medium and long chains. Children 1 and 2 showed increased glutaric acid and multiple dicarboxylic acids by urine Gas chromatography-mass spectrometry (GC-MS) analysis. All children were found to harbor compound heterozygous variants of the ETFDH gene, including a paternal c. 1211T>C (p.M404T) and a maternal c. 488-22T>G variant in child 1, a paternal c. 1717C>T (p.Q573X) and a maternal c. 250G>A (p.A84T) variant in child 2, and a paternal c. 1285+ 1G>A and maternal c. 629A>G (p.S210N) variant in child 3. As for the treatment, high-dose vitamin B2, levocarnitine and coenzyme Q 10 were given to improve the metabolism, in addition with a low fat, hypoproteinic and high carbohydrate diet. All children showed a stable condition with normal growth and development during the follow-up. Conclusion:The compound heterozygous variants of the ETFDH gene probably underlay the muscle weakness, remittent vomiting, elevated short, medium, and long chain acylcarnitine, as well as elevated glutaric acid and various dicarboxylic acids in the three children with type Ⅲ MADD.

Objective:To explore the related risk factors for systemic embolism (SE) in patients aged≥75 years with non-valvular atrial fibrillation (NVAF).Methods:A case-control study. NVAF patients aged≥75 years who were hospitalized at the First Affiliated Hospital of Xinjiang Medical University from October 2018 to October 2020 were divided into no SE ( n=1 127) and SE ( n=433) groups according to the occurrence of SE after NVAF. Multivariate logistic regression was used to analyze SE-related factors in patients with NVAF without anticoagulation treatment. Results:In the multivariate model, the following factors were associated with an increased risk of SE in patients with NVAF: history of AF≥5 years [odds ratio ( OR)=2.75, 95% confidence interval ( CI) 1.98-3.82, P<0.01], lipoprotein(a)>300 g/L ( OR=2.07, 95% CI 1.50-2.84, P<0.01), apolipoprotein (Apo)B>1.2 g/L ( OR=1.91, 95% CI 1.25-2.93, P=0.003), left ventricular ejection fraction (LVEF) of 30%-49% ( OR=2.45, 95% CI 1.63-3.69, P<0.01), left atrial diameter>40 mm ( OR=1.54, 95% CI 1.16-2.07, P=0.003), and CHA 2DS 2-VASc score≥3 ( OR=15.14, 95% CI 2.05-112.13, P=0.01). ApoAI>1.6 g/L was negatively correlated with the occurrence of SE ( OR=0.28, 95% CI 0.15-0.51, P<0.01). Conclusions:History of AF≥5 years, lipoprotein(a)>300 g/L, elevated ApoB, left atrial diameter>40 mm, LVEF of 30%-49%, and CHA 2DS 2-VASC score≥3 are independent risk factors for SE whereas ApoAI>1.6 g/L is a protective factor against SE in patients with NVAF.

Objective:To summarize the clinical phenotype and genetic characteristics of Poirier-Bienvenu neurodevelopmental syndrome associated with CSNK2B gene variation. Methods:The clinical and genetic data of a child with Poirier-Bienvenu neurodevelopmental syndrome caused by shear variant of CSNK2B gene who was diagnosed in the Department of Neurology, Children′s Hospital Affiliated to Zhengzhou University in March 2022 were collected. Previous relevant literature at home and abroad was reviewed to summarize the clinical characteristics of the disease. Results:The child was a girl aged 13 months, mainly due to "intermittent convulsions for 2 months" for consultation. The clinical manifestations of the girl were normal face, generalized tonic-clonic seizures, low intelligence, language and motor retardation, and there was no abnormality in the long-range video electroencephalography and the head magnetic resonance imaging. No abnormality was found in chromosome karyotype analysis and chromosome coefficient of copy variation analysis. The whole exon gene sequencing test indicated that the child carried de novo heterozygous shear variant of CSNK2B gene c.291+5G>C, which had not been reported in the literature. According to the clinical manifestations and genetic examination results of the child, the diagnosis of Poirier-Bienvenu neurodevelopmental syndrome was clear. The CSNK2B gene of the proband′s parents and the twin sister was wild-type. The application of sodium valproate anti-seizure medication could effectively control the seizures of the child, and by giving rehabilitation function training, the child′s language and gross motor function was improved. Conclusions:The Poirier-Bienvenu neurodevelopmental syndrome is a rare autosomal dominant disorder caused by variants in the CSNK2B gene. The clinical manifestations are infancy-onset seizures, intellectual development disorders, language and motor development disorders, etc, and the video electroencephalogram and skull magnetic resonance are mostly normal. The CSNK2B gene shear variant is the genetic etiology of the proband.

The clinical data and gene variant characteristics of a patient with glutathione synthetase (GSS) deficiency were summarized. The child was born 15 min prematurely as a male infant with postnatal respiratory distress, metabolic acidosis, severe anemia, hemolysis, hyperbilirubinemia, and motor developmental backwardness. Blood and urine genetic metabolic screening showed a blood glutamate value of 1 343.1 μmol/L and a urine 5-oxoproline value of 1 873.7 nmol/mg creatinine. Cranial magnetic resonance imaging showed nonspecific subarachnoid widening. Whole-exon gene sequencing of the family line suggested that the GSS gene of the preexisting patient originated from paternal and maternal variants, respectively: c.632_633del (p.Gln211Argfs *8), and c.491G>A (p.Arg164Gln). Complex heterozygous variants of the GSS gene were the genetic etiology of the present case.

ObjectiveTo systematically review the intervention effect of Chinese medicine on the structure and function of testicular Sertoli cells in animal models of impaired spermatogenesis. MethodThe databases， such as China National Knowledge Infrastructure （CNKI），VIP，Wanfang Data，EMbase，and Pubmed，were searched for experimental studies on the effect of Chinese medicine on the structure and function of testicular Sertoli cells in animal models with impaired spermatogenesis. The included studies were evaluated for risks of bias，and the outcome indicators were analyzed with RevMan and Stata software. ResultThirty studies were included，involving 37 randomized controlled trials （RCTs）. As indicated by the Meta-analysis results， compared with the model group，Chinese medicine increased sperm density（SMD=2.42，95% confidence interval（CI）［1.47，3.37］，P<0.000 01）， promoted sperm motility（SMD=2.35，95%CI ［1.70， 2.99］，P<0.000 01）， up-regulated the protein and mRNA levels of Vimentin （related to Sertoli cell cytoskeleton）， elevated the levels of Occludin and Claudin-11 （related to tight junction of blood-testis barrier）， boosted the levels of β-catenin and N-cadherin （related to adherens junction of blood-testis barrier）， raised the level of connexin 43 （Cx43， related to gap junction of blood-testis barrier）， improved the function of Sertoli cells， increased the serum content of Inhibin B （INHB）， and up-regulated the levels of testicular follicle-stimulating hormone receptor （FSHR）， INHB mRNA， androgen-binding protein （ABP） mRNA， transferrin（TF），stem cell factor（SCF），SCF mRNA，glial cell line-derived neurotrophic factor （GDNF），GDNF mRNA，bone morphogenetic protein 4（BMP4），and BMP4 mRNA （P<0.05）. ConclusionChinese medicine can effectively increase sperm density and motility of animal models of impaired spermatogenesis，and improve the structure and function of testicular Sertoli cells. However，affected by the quality of the included studies，the above conclusion needs to be further verified by relevant high-quality studies.

Objective:To observe the motor capacity of patients early after cardiac surgery using a cardiopulmonary exercise test.Methods:Patients who had performed a cardiopulmonary exercise test within 3 months after cardiac surgery were included in this retrospective study. Patients who took the test within 30 days of the operation formed a discharge group ( n=20), those within 30 to 60 days and 60 to 90 days formed the one month and two month groups ( n=10 for both). The discharge group was further divided into an aortic surgery group ( n=9), a bypass surgery group ( n=6) and a valve surgery group ( n=5) according to their procedure. The exercise capacity of each person was measured in terms of the changes in heart rate and systolic pressure from the resting to the anaerobic threshold stage. Anaerobic threshold, peak oxygen uptake and carbon dioxide ventilation equivalent were also recorded. Results:All of the patients completed the cardiopulmonary exercise test above the anaerobic threshold, and no adverse events such as exercise accidents occurred. At the anaerobic threshold the average heart rate of the discharge group was (8.8±7.1)bpm, significantly lower than the averages of the one month and two months groups: (17.0±5.9) and (18.3±10.5)bpm respectively. The average anaerobic thresholds and peak oxygen uptakes of the 1 month and 2 months groups were not significantly different, but they were all significantly higher than the discharge group′s averages. There were, however, no significant differences among the groups in the average changes in their systolic pressure and carbon dioxide ventilation equivalent. Moreover, the average anaerobic threshold and peak oxygen uptake of the aortic surgery group and the bypass surgery group were significantly lower than the valve surgery group′s averages.Conclusions:Postoperative motor ability after cardiac surgery improves significantly for at least 30 days. Patients who have received aortic or bypass surgery have significantly lower exercise capacity than those after valve surgery.

We present a case of severe COVID-19 in a male newborn. A 22-day infant was transferred to Children's Hospital Affiliated to Zhengzhou University due to "intermittent fever for 18 days". The parents of the infant had been living in Wuhan and returned to Xinyang 9 days before delivery. Suspecting COVID-19 infection, a cesarean section was performed at 38 gestational weeks. The diagnosis of COVID-19 in the mother was confirmed at 2 days postpartum, as well as the father and the grandparents-in-law within 5 days postpartum. The baby developed fever and cough 5 days after birth, and a positive result for the new coronavirus nucleic acid test in the pharyngeal swab was shown 6 days after birth. The fever continued intermittently for 18 days, whilst nasal catheter oxygen inhalation treatment was administered. The percutaneous oxygen saturation decreased to 79% after cessation of oxygen, and the baby was transferred to the hospital for further treatment. After admission, the infant presented with cough, occasional choke, shortness of breath despite nasal catheter oxygen inhalation, increased heart rate, low urine volume, and an enlarged liver 2 cm below the right costal margin. The baby was diagnosed with severe COVID-19 accompanied by anemia, hyperkalemia, pneumonia, and atrial septal defect seen on the echocardiogram. After isolation in an incubator, oxygen inhalation, cardiotonic intervention, blood transfusion and antiviral treatment, the patient made a good recovery, with good breastfeeding, significant resorption of the lung inflammation and no fever or respiratory symptoms. The baby was discharged 14 days after hospitalization, with negative results for nucleic acid test of pharyngeal swab for 2 consecutive times.

The professional identity and the influencing factors were surveyed among 110 resident physicians of general practice standardized training program in the First Affiliated Hospital of Xi'an Medical College with a self-designed questionnaire,and 100 valid questionnaires were received.The average score of professional identity was (66.10 ± 13.644),and the six dimensions ranked from high to low:professional behavior,professional efficacy,professional cognition,professional emotion,professional value and professional commitment.There were significant differences in the scores of professional identity among general practitioners with different monthly income(F=2.947,P=0.037).The survey indicates that the professional identity of the resident physicians of general practice standardized training program is generally low and the income is an important influencing factor.