Nonobstructive azoospermia (NOA), one of the most severe types of male infertility, etiology often remains unclear in most cases. Therefore, this study aimed to detect four biallelic detrimental variants (0.5%) in the minichromosome maintenance domain containing 2 ( MCMDC2 ) genes in 768 NOA patients by whole-exome sequencing (WES). Hematoxylin and eosin (H&E) demonstrated that MCMDC2 deleterious variants caused meiotic arrest in three patients (c.1360G>T, c.1956G>T, and c.685C>T) and hypospermatogenesis in one patient (c.94G>T), as further confirmed through immunofluorescence (IF) staining. The single-cell RNA sequencing data indicated that MCMDC2 was substantially expressed during spermatogenesis. The variants were confirmed as deleterious and responsible for patient infertility through bioinformatics and in vitro experimental analyses. The results revealed four MCMDC2 variants related to NOA, which contributes to the current perception of the function of MCMDC2 in male fertility and presents new perspectives on the genetic etiology of NOA.
Humans ; Male ; Azoospermia/genetics* ; Meiosis/genetics* ; Spermatogenesis/genetics* ; Adult ; Exome Sequencing ; Microtubule-Associated Proteins/genetics* ; Alleles ; Infertility, Male/genetics*

OBJECTIVE: High-altitude hypoxia exposure often damages hippocampus-dependent learning and memory. Nogo-A is an important axonal growth inhibitory factor. However, its function in high-altitude hypoxia and its mechanism of action remain unclear. METHODS: In an in vivo study, a low-pressure oxygen chamber was used to simulate high-altitude hypoxia, and genetic or pharmacological intervention was used to block the Nogo-A/NgR1 signaling pathway. Contextual fear conditioning and Morris water maze behavioral tests were used to assess learning and memory in rats, and synaptic damage in the hippocampus and changes in oxidative stress levels were observed. In vitro, SH-SY5Y cells were used to assess oxidative stress and mitochondrial function with or without Nogo-A knockdown in Oxygen Glucose-Deprivation/Reperfusion (OGD/R) models. RESULTS: Exposure to acute high-altitude hypoxia for 3 or 7 days impaired learning and memory in rats, triggered oxidative stress in the hippocampal tissue, and reduced the dendritic spine density of hippocampal neurons. Blocking the Nogo-A/NgR1 pathway ameliorated oxidative stress, synaptic damage, and the learning and memory impairment induced by high-altitude exposure. CONCLUSION: Our results demonstrate the detrimental role of Nogo-A protein in mediating learning and memory impairment under high-altitude hypoxia and suggest the potential of the Nogo-A/NgR1 signaling pathway as a crucial therapeutic target for alleviating learning and memory dysfunction induced by high-altitude exposure. GRAPHICAL ABSTRACT available in www.besjournal.com.
Animals ; Oxidative Stress ; Hippocampus/metabolism* ; Rats ; Nogo Proteins/genetics* ; Male ; Rats, Sprague-Dawley ; Hypoxia/metabolism* ; Altitude ; Synapses ; Humans ; Altitude Sickness/metabolism*

Objective To observe the intervention effect of hypericin(HYP)on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson's disease(PD)mice model and its mechanism.Methods Thirty C57BL/6 mice were randomly divided into normal,model and experimental groups with 10 mice per group.PD mouse model was established after 7 days of intraperitoneal injection of MPTP,and drug intervention was carried out from the first day of modeling.Normal group and model group were intraperitoneally injected with 500 μL·kg·d-1 0.9％NaCl.The experimental group was intraperitoneally injected with 25 mg·kg·d-1 HYP.The three groups of rats were given the drug once each time for 14 days.The expression levels of tyrosine hydroxylase(TH),Nod-like receptor thermal protein domain protein 3(NLRP3)and ionized calcium binding adapter molecule 1(Iba1)in the striatum of nigra were detected by Western blot.Results The climbing time of normal,model and experimental groups was(5.35±0.43),(9.71±1.19)and(8.07±0.34)s;suspension scores were(2.92±0.15),(1.38±0.28)and(1.96±0.28)points;the relative expression levels of TH protein were 1.04±0.06,0.51±0.09 and 0.75±0.07;the relative expression levels of NLRP3 protein were 0.51±0.03,1.00±0.04 and 0.77±0.06;the relative expression levels of Iba1 protein were 0.68±0.10,1.30±0.28 and 0.89±0.05,respectively.The above indexes in the model group were statistically significant compared with the experimental group and the normal group(all P＜0.01).Conclusion HYP plays a therapeutic role in PD by inhibiting the expression of NLRP3 inflammasome in PD mice.

Objective To explore the changes in gut microbiota and levels of short-chain fatty acids(SCFA)in infants with cow's milk protein allergy(CMPA),and to clarify their role in CMPA.Methods A total of 25 infants diagnosed with CMPA at Children's Hospital Affiliated to Zhengzhou University from August 2019 to August 2020 were enrolled as the CMPA group,and 25 healthy infants were selected as the control group.Fecal samples(200 mg)were collected from both groups and subjected to 16S rDNA high-throughput sequencing technology and liquid chromatography-mass spectrometry to analyze the changes in gut microbial composition and metabolites.Microbial diversity was analyzed in conjunction with metabolites.Results Compared to the control group,the CMPA group showed altered gut microbial structure and significantly increased α-diversity(P＜0.001).The abundance of Firmicutes,Clostridiales and Bacteroidetes was significantly decreased,while the abundance of Sphingomonadaceae,Clostridiaceae_l and Mycoplasmataceae was significantly increased in the CMPA group compared to the control group(P＜0.001).Metabolomic analysis revealed reduced levels of acetic acid,butyric acid,and isovaleric acid in the CMPA group compared to the control group,and the levels of the metabolites were positively correlated with the abundance of SCFA-producing bacteria such as Faecalibacterium and Roseburia(P＜0.05).Conclusions CMPA infants have alterations in gut microbial structure,increased microbial diversity,and decreased levels of SCFA,which may contribute to increased intestinal inflammation.[Chinese Journal of Contemporary Pediatrics,2024,26(3):236-243]

Objective To study the risk factors for embolism in children with refractory Mycoplasma pneumoniae pneumonia(RMPP)and to construct a nomogram model for prediction of embolism.Methods This retrospective study included 175 children diagnosed with RMPP at Children's Hospital Affiliated to Zhengzhou University from January 2019 to October 2023.They were divided into two groups based on the presence of embolism:the embolism group(n=62)and the non-embolism group(n=113).Multivariate logistic regression analysis was used to screen for risk factors of embolism in children with RMPP,and the R software was applied to construct the nomogram model for prediction of embolism.Results Multivariate logistic regression analysis indicated that higher levels of D-dimer,interleukin-6(IL-6)and neutrophil to lymphocyte ratio(NLR),lung necrosis,and pleural effusion were risk factors for embolism in children with RMPP(P＜0.05).The area under the curve of the nomogram model for prediction of embolism constructed based on the aforementioned risk factors was 0.912(95％CI:0.871-0.952,P＜0.05).The Hosmer-Lemeshow goodness-of-fit test showed that the model had a good fit with the actual situation(P＜0.05).Calibration and decision curve analysis indicated that the model had high predictive efficacy and clinical applicability.Conclusions Higher levels of D-dimer,IL-6 and NLR,lung necrosis,and pleural effusion are risk factors for embolism in children with RMPP.The nomogram model based on these risk factors has high clinical value for predicting embolism in children with RMPP.

Objective To observe the effects of Wuzi Yanzong Pill(WYP)on motor function in a mouse model of Parkinson's disease(PD)and to explore its potential mechanisms.Methods Twenty-four male C57BL/6 mice were randomly divided into control group,model group and WYP group,with 8 mice in each group.Mice in model and WYP group were intraperitoneally injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine for 7 consecutive days to establish a PD model.From the 1st day of model preparation,mice in WYP group were gavaged with WYP solution[16 g/(kg·d)]twice daily for 14 consecutive days.At the same time,mice in control group and model group were gavaged with 0.9%NaCl solution[50 ml/(kg·d)]twice a day.Gait experiment was utilized to assess the behavioral performance of mice in each group.Immunofluorescence staining was conducted to detect the number of tyrosine hydroxylase(TH)-positive cells in the substantia nigra region,the fluorescence intensity of nuclear factor E2-related factor 2(Nrf2),and the number of NeuN neurons co-labeled with Nrf2 in each group.Western blotting was employed to determine the expression levels of TH,Kelch-like ECH-associated protein 1(Keap-1),Nrf2,and heme oxygenase-1(HO-1)in the brain tissue of mice in each group.Results The gait experiment results showed that,compared with control group,standing time of the left front paw,right front paw,left hind paw,and right hind paw of the mice in model group was significantly shortened(P<0.01),while swinging time of the left front paw,right front paw,left hind paw,and right hind paw was significantly prolonged(P<0.05).Compared with model group,standing time of the left front paw and right hind paw of the mice in WYP group was significantly prolonged(P<0.05),while swing time of the left front paw and right front paw was significantly shortened(P<0.05).Immunofluorescence staining and Western blotting results showed that,compared with control group,in model group the number of TH-positive cells,average fluorescence intensity of Nrf2,and HO-1 levels decreased(P<0.01),while the Keap-1 protein level increased(P<0.01),and the number of Nrf2 expression on NeuN neurons decreased(P<0.001).Compared with model group,the number of TH-positive cells,average fluorescence intensity of Nrf2,HO-1 level,and the number of Nrf2 expression on NeuN neurons in the brain tissue of mice in WYP group increased(P<0.05),while Keap-1 protein level decreased(P<0.05).Conclusions WYP could alleviate the motor dysfunction and protect dopaminergic neurons in PD mice.The underlying mechanism may be related to the regulation of Keap-1/Nrf2/HO-1 pathway to inhibit oxidative stress response.

Objective To investigate the effects of astragaloside Ⅳ(AS-Ⅳ)on axon growth inhibitory factor A(Nogo-A)and its downstream pathway protein RHO-associated coiled spiral kinase 2(ROCK2)in experimental autoimmune encephalomyelitis(EAE)mice,and to explore the mechanism by which it promotes axon repair and regeneration.Methods EAE model was induced in C57BL/6 female mice by subcutaneous injection of myelin oligodendrocyte glycoprotein 35-55(MOG35-55).Mice were randomly divided into EAE group and AS-Ⅳ group(n=8 per group).EAE group received intraperitoneal injection of PBS on the 3rd day post-immunization,while AS-Ⅳ group was administered AS-Ⅳ at a dosage of 30mg/(kg.d)once daily,0.2 ml per injection,for 25 consecutive days.On the 28th day post-immunization,the expression levels of growth-associated protein 43(GAP-43),neuronal core antigen(NeuN),microtubule associated protein 2(MAP-2),glial fibroacidic protein(GFAP),and Iba1 in the spinal cord were detected using immunofluorescence assay.Real-time fluorescence quantitative PCR(qRT-PCR)was conducted to detect mRNA expression levels of GAP-43,Nogo-A,and Nogo receptor(NgR)genes.Western blotting was utilized to determine the expression levels of GAP-43,Nogo-A,ROCK2,phosphorylated myosin phosphatase(p-MYPT1),B-lymphoblastoma-2(Bcl-2),and Bcl-2 associated X protein(Bax).Results Compared with EAE group,AS-Ⅳ treatment significantly reduced the positive cell expression rates of Iba1 microglia and GFAP astrocyte in spinal cord(P<0.01 and P<0.001,respectively),while it also increased the positive expression rates of NeuN and MAP-2(P<0.001 and P<0.05,respectively).The treatment also upregulated the expression level of anti-apoptotic factor Bcl-2(P<0.001)and downregulated the expression level of pro-apoptotic factor Bax(P<0.05),leading to an increase in Bcl-2/Bax ratio(P<0.05).Furthermore,AS-Ⅳ enhanced the expression of GAP-43 protein(P<0.05)and decreased the mRNA expression levels of neuroregeneration inhibitor Nogo receptor(NgR)and ROCK2 gene(P<0.001,P<0.05,respectively);as well as decreased the expression levels of Nogo-A,ROCK2 and p-MYPT1 proteins(P<0.05,P<0.001).Conclusion AS-Ⅳ may inhibit the activation of microglia and astrocytes and neuronal apoptosis in EAE mice by inhibiting Nogo-A and downstream pathway ROCK 2,thereby promoting the expression of GAP-43,NeuN and MAP-2,alleviating neuronal damage,and facilitating axon repair and regeneration.

Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]

Objective: This study aimed to determine the predictive performance of non-contrast CT (NCCT) signs for hemorrhagic growth after intracerebral hemorrhage (ICH) when stratified by onset-to-imaging time (OIT). Materials and Methods: 1488 supratentorial ICH within 6 h of onset were consecutively recruited from six centers between January 2018 and August 2022. NCCT signs were classified according to density (hypodensities, swirl sign, black hole sign, blend sign, fluid level, and heterogeneous density) and shape (island sign, satellite sign, and irregular shape) features. Multivariable logistic regression was used to evaluate the association between NCCT signs and three types of hemorrhagic growth: hematoma expansion (HE), intraventricular hemorrhage growth (IVHG), and revised HE (RHE). The performance of the NCCT signs was evaluated using the positive predictive value (PPV) stratified by OIT. Results: Multivariable analysis showed that hypodensities were an independent predictor of HE (adjusted odds ratio [95% confidence interval] of 7.99 [4.87–13.40]), IVHG (3.64 [2.15–6.24]), and RHE (7.90 [4.93–12.90]). Similarly, OIT (for a 1-h increase) was an independent inverse predictor of HE (0.59 [0.52–0.66]), IVHG (0.72 [0.64–0.81]), and RHE (0.61 [0.54– 0.67]). Blend and island signs were independently associated with HE and RHE (10.60 [7.36–15.30] and 10.10 [7.10–14.60], respectively, for the blend sign and 2.75 [1.64–4.67] and 2.62 [1.60–4.30], respectively, for the island sign). Hypodensities demonstrated low PPVs of 0.41 (110/269) or lower for IVHG when stratified by OIT. When OIT was ≤ 2 h, the PPVs of hypodensities, blend sign, and island sign for RHE were 0.80 (215/269), 0.90 (142/157), and 0.83 (103/124), respectively. Conclusion Hypodensities, blend sign, and island sign were the best NCCT predictors of RHE when OIT was ≤ 2 h. NCCT signs may assist in earlier recognition of the risk of hemorrhagic growth and guide early intervention to prevent neurological deterioration resulting from hemorrhagic growth.

Objective To explore the role pathway and pattern of the myeloma cancer gene (MYC) and its mRNA interaction with the microRNAs(miRNAs) and circular RNA(circRNAs) at hour 0, hour 6 and hour 72 in the rat liver regeneration. Methods The rat 2/3 hepatectomy (PH) model was prepared as described by Higgins, the hepatocytes were isolated according to the method of Smedsrod et al. The expression changes of mRNA, miRNA and circRNA [together named as competing endogenous RNA (ceRNA)] were detected by the large-scale quantitative detection technology, the interaction network of ceRNA was constructed by Cytoscape 3.2 software, and their correlation in expression and role were analyzed by ceRNA comprehensive analysis. Results It was found that at hour 0 and hour 6 after PH, the ratio value of MYC mRNA showed 0.15±0.03 and 2.36±0.20, miR-134-5p indicated 3.22±0.61 and 0.08±0.02, circRNA_12112 displayed 0.68±0.21 and 13.35±3.53. At the same time, the cell cycle initiation-related genes ras association domain family member 1 (RASSF1), cyclin dependent kinase 2 (CDK2), superoxide dismutase 2 (SOD2), which were promoted in expression by MYC, were down-regulated at hour 0 after PH, but the cell cycle initiation-related genes nestin (NES), RAD21 cohesin complex component (RAD21), CUE domain containing 2 (CUEDC2), which are inhibieted in expression by MYC, had no meaningful express changes at hour 0 after PH. On the other hand, the cell cycle initiation-related gene SOD2, which was promoted in expression by MYC, was up-regulated at hour 6 after PH, but the cell cycle initiation-related genes NES, RAD21, CUEDC2, which are inhibieted in expression by MYC, were down-regulated at hour 6 after PH. In contrary, at hour 72 after PH, the ratio value of MYC mRNA showed 2.36±0.20, miR-880-3p indicated 0.54±0.01, circRNA_09599 displayd 0.54±0.16. At the same time, the cell cycle termination-related gene hepatocyte growth factor (HGF), which is promoted in expression by MYC, was up-regulated 72 hours after PH, the cell cycle termination-related genes MET proto-oncogene receptor tyrosine kinase (MET) and cyclin dependent kinase inhibitor 1A (CDKN1A), which are inhibieted in expression by MYC, were down-regulated 72 hours after PH. Conclusion The correlation in expression and role of the miRNAs, which are inhibited by circRNAs, MYC, its mRNA is inhibited by miRNAs, and the cell cycle initiation-related and cell cycle termination-related genes, which are regulated by MYC, are helpful for the hepatocyte to be in cell cycle initiation state at hour 6 after PH and to be in cell cycle termination state at hour 72 after PH.