OBJECTIVE To investigate the selection strategy for recipient vessels in free flap reconstruction of head and neck defects.METHODS A retrospective analysis was conducted on 96 patients who underwent 99 free flap reconstructions for head and neck defects between January 2020 and December 2024.Recipient vessel selection,flap survival,and postoperative complications were analyzed based on defect location and flap type.RESULTS In 99 cases microvessel anastomosis,the recipient arteries were superior thyroid artery in 49 branches,facial artery in 28 branches,superficial temporal artery in 14 branches,lingual artery in 5 branches.external carotid artery in 1 branch,transverse cervical artery in 1 branch,and superior laryngeal artery in 1 branch.Venous anastomosis was performed in 104 branches,with 94 cases in 1 venous anastomosis and 5 cases in 2 venous anastomoses.The recipient veins selected were facial vein in 62 branches,external jugular vein in 21 branches,superficial temporal vein in 12 branches,retromandibular vein in 3 branches,middle thyroid vein in 2 branches,internal jugular vein in 2 branches,middle temporal vein in 1 branch,and superior thyroid vein in 1 branch.Complete flap necrosis occurred in 5 cases,and partial necrosis occurred in 4 cases.When the recipient vessels were deficient,the lingual artery was chosen in 3 cases,the facial artery in 1 case,the external jugular vein in 3 cases,the internal jugular vein with end-to-side anastomosis in 1 case,and the common facial vein with end-to-side anastomosis in 1 case.CONCLUSION In free flap reconstruction for head and neck defects,the superior thyroid artery,facial artery,and superficial temporal artery are commonly used as recipient arteries,while the facial vein,external jugular vein,and superficial temporal vein are frequently selected as recipient veins.When recipient vessels are scarce,the ipsilateral lingual artery,transverse cervical artery,and main trunk of the internal jugular vein can serve as alternative recipient vessels.

Objective To summarize and analyze the clinical efficacy of negative pressure suction bell in the treatment of young children (≤6 years) with pectus excavatum. Methods The relevant clinical medical records of the children with pectus excavatum who received negative pressure suction bell treatment in the Outpatient Department of Children’s Hospital of Chongqing Medical University from May 2019 to January 2023 were collected. The age, sex, type, severity, depth of depression, duration of use and prognosis of children with pectus excavatum were retrospectively analyzed. Results A total of 100 pediatric patients were ultimately included in the study, comprising 74 males and 26 females. The age distribution was 57 patients aged 0-3 years and 43 patients aged 3-6 years. All patients were prescribed and used a negative pressure suction device for at least 3 months, after which they returned to our department's outpatient clinic for follow-up. The treatment demonstrated clinical effectiveness in 99 patients, yielding an efficacy rate of 99.00%. The excellent/good rate was 52.00%, and the complication rate was 8.00%. After treatment, the Haller index and the depth of sternal depression were reduced compared with those before treatment (P<0.001), and there was no statistical difference in the effective rate and excellent/good rate between different genders, different ages, different types of pectus excavatum, or different severity (P＞0.05). Conclusion Negative pressure suction bell is safe and effective in the treatment of young children (≤6 years) with pectus excavatum, and the correction effect has nothing to do with gender, type and severity.

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 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.

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 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.