Mitochondrial diabetes mellitus (MDM) is a genetically heterogeneous disorder caused by mitochondrial DNA (mtDNA) or nuclear DNA mutations, characterized by multi-system involvement and diverse clinical phenotypes. We report a pediatric case presenting with growth retardation followed by subsequent development of diabetes mellitus. Systematic evaluation revealed concurrent bilateral sensorineural hearing loss, bilateral basal ganglia calcification, and electroencephalographic abnormalities. A post-exercise lactate test demonstrated significant elevation of serum lactate levels immediately after physical exertion. Genetic analysis identified a large-scale mitochondrial DNA deletion spanning from m.8649 to m.16084. This case report is complemented by a literature review focusing on the pathogenesis, genetic characteristics, and therapeutic approaches of mitochondrial diabetes, with particular emphasis on mitochondrial disorders exhibiting large-scale mtDNA deletions alongside diabetic manifestations. Our comprehensive analysis aims to enhance clinical understanding and inform diagnostic strategies for this complex disease entity.

Objective To evaluate the effects of 3-indoleacetic acid(IPA)on epithelial-mesenchymal transition(EMT)and fi-brosis in mice peritoneal mesoepithelial cells stimulated by lipopolysaccharide.Methods Mouse peritoneal mesothelial cells be-fore and after LPS treatment were interfered with IPA at different concentrations(0.1,1.0 and 10 μmol/L),and the cell prolif-eration activity was examined by CCK-8 method to determine the optimal dose of IPA.Mice peritoneal mesothelium cells were divided into Control group,LPS group,LPS+IPA group,LPS+LY364947(TGF-β1 receptor inhibitor)group,LPS+IPA+LY364947 group and LPS+IPA+SRI-011381(TGF-β1 pathway activator)group.Cell proliferation viability was evaluated by CCK-8 assay and cell invasion was detected by Transwell assay.EMT-related factor(E-cadherin)and TGF-β1/Smad3 pathway-related factor(Smad3,p-Smad3)protein expression in cell supernatant was evaluated by Western blotting,and mesenchymal phe-notype α-smooth muscle actin(α-SMA)protein content was detected by ELISA.Results The optimal dose of IPA was 1.0μmol/L.Compared with Control group,cell proliferation and E-cadherin expression level were decreased(all P＜0.01).Invasivi-ty,α-SMA expression and p-Smad3/Smad3 were increased in LPS group(all P＜0.01).Compared with LPS group,cell prolifer-ative activity and E-cadherin expression level were increased(all P＜0.01),and invasivity,α-SM A expression and p-Smad3/Smad3 were decreased in LPS+IPA and LPS+LY364947 groups(all P＜0.01).Compared with LPS+IPA group,LPS+IPA+LY364947 group showed a more significant trend.The trends of measured indexes were reversed after SRI-011381 treatment in LPS+IPA group.Conclusion IPA inhibits Smad3 phosphorylation,thereby inhibiting cell EMT progression and alleviating LPS-induced peritoneal mesothelial cell injury.

Objective:To investigate the effects of wza gene deletion in Klebsiella pneumoniae on capsule formation ability and bacteriophage sensitivity. Methods:The wza deletion mutant strain was constructed through a temperature-sensitive plasmid-mediated homologous recombination. The growth curves of W14 and Δ wza were detected by measuring the optical density OD 600. In order to analyze the effect of gene wza on bacterial capsule formation, wild-type strain W14 and Δ wza mutant strain were detected by transmission electron microscope, and their capsule contents were measured by quantifying the uronic acid contents. The plaque assay was used to detect bacterial sensitivity to bacteriophage in wild-type strain W14 and Δ wza mutant strain. The t test was used to compare whether there were differences in the contents of uronic acid in the capsules of wild-type strain W14 and Δ wza mutant strain. Results:The PCR results revealed that the Δ wza mutant strain was successfully constructed. Compared with wild-type strain W14, the growth curves of Δ wza on the solid plates demonstrated a slightly slower growth. However, no difference in growth was observed among wild-type strain W14 and Δ wza mutant strains in LB broth. The transmission electron microscope results showed that wza gene deletion resulted in the loss of capsule in bacteria. The uronic acid content assay suggested that the capsule content was significantly decreased in Δ wza mutant strain (45.963±2.795) μg/ml compared with wild-type strain W14 (138.800±5.201) μg/ml. There was a statistical difference between the two groups ( t=27.233, P<0.001). The plaque assay indicated that bacteria lost its sensitivity to bacteriophage when gene wza was deleted. Conclusion:Deletion of the wza gene impairs bacterial capsule formation ability and can affect bacterial sensitivity to bacteriophage phiW14.

Objective:To express and purify the phage depolymerase from hypervirulent Klebsiella pneumoniae (hv Kp) serotype K1 and validate its function. Methods:Phage that infected serotype K1-type hv Kp was isolated from hospital sewage. The biology and morphology of the phage were determined by plaque assay and transmission electron microscopy. The whole genome of the phage was sequenced by the Illumina HiSeq 2500 platform. The presence of depolymerase was determined by observing the plaque halo. Bioinformatic analysis and prokaryotic protein expression system were further used to predict and identify phage depolymerase. The depolymerase gene fragment was obtained by PCR and cloned into the pET28a expression vector, and the expression and purification of the depolymerase were completed in strain BL21. The depolymerase activities on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates were detected by plaque assay and low-speed centrifugation assay. Results:A lytic phage (phiA2) that infected serotype K1-type hv Kp clinical isolate was isolated from hospital sewage. It was typical of the Caudovirales order and Autographiviridae family, and its whole genome was 43 526 bp in length and contained 51 coding domain sequences. The phage phiA2-derived depolymerase phiA2-dep was predicted, expressed and purified. The plaque assay and low-speed centrifugation assay indicated that the depolymerase phiA2-dep had good lytic activity on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates. Conclusion:Depolymerase phiA2-dep can specifically degrade the capsular polysaccharide of serotype K1-type hv Kp, which has potential application value in treating bacterial infection.

Objective To evaluate the efficacy of a modified sericin hydrogel scaffold loaded with dexamethasone(SMH-CD/DEX)scaffold for promoting bone defect healing by stimulating anti-inflammatory macrophage polarization.Methods The light-curable SMH-CD/DEX scaffold was prepared using dexamethasone-loaded NH2-β-cyclodextrin(NH2-β-CD)and sericin hydrogel and characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),biocompatibility assessment and drug release test.THP-1 macrophages incubated with the scaffold were examined for protein expressions of iNOS and Arg-1,mRNA expressions of IL-6,Il-10,Arg-1 and iNOS,and surface markers CD86 and CD206 using Western blotting,RT-qPCR,and flow cytometry.In a co-culture system of human periodontal ligament stem cells(HPDLSCs)and THP-1 macrophages,the osteogenic ability of the stem cells incubated with the scaffold was evaluated by detecting protein expressions of COL1A1 and Runx2 and expressions of ALP,Runx2,OCN and BMP2 mRNA,ALP staining,and alizarin red staining.In a rat model of mandibular bone defect,the osteogenic effect of the scaffold was assessed by observing bone regeneration using micro-CT and histopathological staining.Results In THP-1 macrophages,incubation with SMH-CD/DEX scaffold significantly enhanced protein expressions of Arg-1 and mRNA expressions of IL-10 and Arg-1 and lowered iNOS protein expression and IL-6 and iNOS mRNA expressions.In the co-culture system,SMH-CD/DEX effectively increased the protein expressions of COL1A1 and Runx2 and mRNA expressions of ALP and BMP2 in HPDLSCs and promoted their osteogenic differentiation.In the rat models,implantation of SMH-CD/DEX scaffold significantly promoted bone repair and bone regeneration in the bone defect.Conclusion The SMH-CD/DEX scaffold capable of sustained dexamethasone release promotes osteogenic differentiation of stem cells and bone defect repair in rats by regulating M2 polarization.

Objective To evaluate the predictive value of global longitudinal strain(GLS)measured by cardiac magnetic resonance(CMR)feature-tracking technique for left ventricular remodeling(LVR)after percutaneous coronary intervention(PCI)in patients with acute ST-segment elevation myocardial infarction(STEMI).Methods A total of 403 patients undergoing PCI for acute STEMI were prospectively recruited from multiple centers in China.CMR examinations were performed one week(7±2 days)and 6 months after myocardial infarction to obtain GLS,global radial strain(GRS),global circumferential strain(GCS),ejection fraction(LVEF)and infarct size(IS).The primary endpoint was LVR,defined as an increase of left ventricle end-diastolic volume by≥20%or an increase of left ventricle end-systolic volume by≥15%from the baseline determined by CMR at 6 months.Logistic regression analysis was performed to evaluate the predictive value of CMR parameters for LVR.Results LVR occurred in 101 of the patients at 6 months after myocardial infarction.Compared with those without LVR(n=302),the patients in LVR group exhibited significantly higher GLS and GCS(P<0.001)and lower GRS and LVEF(P<0.001).Logistic regression analysis indicated that both GLS(OR=1.387,95%CI:1.223-1.573;P<0.001)and LVEF(OR=0.951,95%CI:0.914-0.990;P=0.015)were independent predictors of LVR.ROC curve analysis showed that at the optimal cutoff value of-10.6%,GLS had a sensitivity of 74.3%and a specificity of 71.9%for predicting LVR.The AUC of GLS was similar to that of LVEF for predicting LVR(P=0.146),but was significantly greater than those of other parameters such as GCS,GRS and IS(P<0.05);the AUC of LVEF did not differ significantly from those of the other parameters(P>0.05).Conclusion In patients receiving PCI for STEMI,GLS measured by CMR is a significant predictor of LVR occurrence with better performance than GRS,GCS,IS and LVEF.

Objective:To investigate the effects of wza gene deletion in Klebsiella pneumoniae on capsule formation ability and bacteriophage sensitivity. Methods:The wza deletion mutant strain was constructed through a temperature-sensitive plasmid-mediated homologous recombination. The growth curves of W14 and Δ wza were detected by measuring the optical density OD 600. In order to analyze the effect of gene wza on bacterial capsule formation, wild-type strain W14 and Δ wza mutant strain were detected by transmission electron microscope, and their capsule contents were measured by quantifying the uronic acid contents. The plaque assay was used to detect bacterial sensitivity to bacteriophage in wild-type strain W14 and Δ wza mutant strain. The t test was used to compare whether there were differences in the contents of uronic acid in the capsules of wild-type strain W14 and Δ wza mutant strain. Results:The PCR results revealed that the Δ wza mutant strain was successfully constructed. Compared with wild-type strain W14, the growth curves of Δ wza on the solid plates demonstrated a slightly slower growth. However, no difference in growth was observed among wild-type strain W14 and Δ wza mutant strains in LB broth. The transmission electron microscope results showed that wza gene deletion resulted in the loss of capsule in bacteria. The uronic acid content assay suggested that the capsule content was significantly decreased in Δ wza mutant strain (45.963±2.795) μg/ml compared with wild-type strain W14 (138.800±5.201) μg/ml. There was a statistical difference between the two groups ( t=27.233, P<0.001). The plaque assay indicated that bacteria lost its sensitivity to bacteriophage when gene wza was deleted. Conclusion:Deletion of the wza gene impairs bacterial capsule formation ability and can affect bacterial sensitivity to bacteriophage phiW14.

Objective:To express and purify the phage depolymerase from hypervirulent Klebsiella pneumoniae (hv Kp) serotype K1 and validate its function. Methods:Phage that infected serotype K1-type hv Kp was isolated from hospital sewage. The biology and morphology of the phage were determined by plaque assay and transmission electron microscopy. The whole genome of the phage was sequenced by the Illumina HiSeq 2500 platform. The presence of depolymerase was determined by observing the plaque halo. Bioinformatic analysis and prokaryotic protein expression system were further used to predict and identify phage depolymerase. The depolymerase gene fragment was obtained by PCR and cloned into the pET28a expression vector, and the expression and purification of the depolymerase were completed in strain BL21. The depolymerase activities on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates were detected by plaque assay and low-speed centrifugation assay. Results:A lytic phage (phiA2) that infected serotype K1-type hv Kp clinical isolate was isolated from hospital sewage. It was typical of the Caudovirales order and Autographiviridae family, and its whole genome was 43 526 bp in length and contained 51 coding domain sequences. The phage phiA2-derived depolymerase phiA2-dep was predicted, expressed and purified. The plaque assay and low-speed centrifugation assay indicated that the depolymerase phiA2-dep had good lytic activity on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates. Conclusion:Depolymerase phiA2-dep can specifically degrade the capsular polysaccharide of serotype K1-type hv Kp, which has potential application value in treating bacterial infection.

Objective:To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods:The prospective multicenter study was conducted in Zhejiang, China from May 1 st, 2019 to January 31 st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results:A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95% CI 0.593-0.771, P<0.01). Conclusion:In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.

Objective To evaluate the efficacy of a modified sericin hydrogel scaffold loaded with dexamethasone(SMH-CD/DEX)scaffold for promoting bone defect healing by stimulating anti-inflammatory macrophage polarization.Methods The light-curable SMH-CD/DEX scaffold was prepared using dexamethasone-loaded NH2-β-cyclodextrin(NH2-β-CD)and sericin hydrogel and characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),biocompatibility assessment and drug release test.THP-1 macrophages incubated with the scaffold were examined for protein expressions of iNOS and Arg-1,mRNA expressions of IL-6,Il-10,Arg-1 and iNOS,and surface markers CD86 and CD206 using Western blotting,RT-qPCR,and flow cytometry.In a co-culture system of human periodontal ligament stem cells(HPDLSCs)and THP-1 macrophages,the osteogenic ability of the stem cells incubated with the scaffold was evaluated by detecting protein expressions of COL1A1 and Runx2 and expressions of ALP,Runx2,OCN and BMP2 mRNA,ALP staining,and alizarin red staining.In a rat model of mandibular bone defect,the osteogenic effect of the scaffold was assessed by observing bone regeneration using micro-CT and histopathological staining.Results In THP-1 macrophages,incubation with SMH-CD/DEX scaffold significantly enhanced protein expressions of Arg-1 and mRNA expressions of IL-10 and Arg-1 and lowered iNOS protein expression and IL-6 and iNOS mRNA expressions.In the co-culture system,SMH-CD/DEX effectively increased the protein expressions of COL1A1 and Runx2 and mRNA expressions of ALP and BMP2 in HPDLSCs and promoted their osteogenic differentiation.In the rat models,implantation of SMH-CD/DEX scaffold significantly promoted bone repair and bone regeneration in the bone defect.Conclusion The SMH-CD/DEX scaffold capable of sustained dexamethasone release promotes osteogenic differentiation of stem cells and bone defect repair in rats by regulating M2 polarization.