Objective:Objective The potential of a three- dimensional bioprinted cell-laden gelatin methactyloyl (GelMA)+ hyaluronic acid (HA) composite bioink in tissue engineering was assessed by evaluating cell viability, scaffold morphology, and cell compatibility.Methods:Rabbit chondrocytes were isolated and cultured. Composite hydrogels were prepared using GelMA and HA, and their applicability in tissue engineering was assessed by evaluating physicochemical properties, cytocompatibility, and printability. The swelling and mechanical properties of 100g/L GelMA inks as the control group, and 100g/L GelMA+ 20g/L HA inks as the experimental group were assessed following photocrosslinking of the cylindrical model. The printing resolution of the GelMA/HA mesh scaffold loaded with chondrocytes was evaluated based on appearance and expansion ratio. Cell viability was determined using cell live/dead test after 14 days, while cytocompatibility was observed through in vitro microscopy and multiple immunofluorescence staining after 7 days. GraphPad Prism 8.0 was utilized for data visualization and statistical analysis. Independent-samples t-test was employed to compare differences among groups. A P-value less than 0.05 was considered statistically significant. Results:The swelling ratio of GelMA group was 10.57±0.40, which exceeded that of the GelMA+ HA group (7.63±0.61, P<0.05). The compressive elastic modulus of GelMA+ HA group measured (77.53±4.30) kPa, significantly surpassing that of the GelMA group [(25.60±5.70) kPa, P<0.05]. The extension ratio of GelMA was 2.59±0.33, while the experimental group recorded 2.66±0.12, with no statistically significant difference between them ( P>0.05). There were no notable disparities in cell viability between the two groups; both exhibited viabilities greater than 85%. On the initial day of culture, both groups exhibited intact structures, regular pores, and a substantial number of spherical cells. After 14 days of culture, the GelMA scaffold structure appeared blurred with nearly vanished pores, while large live cells were visible. The GelMA+ HA scaffold structure was slightly more relaxed with relatively intact pores and a significant presence of live cells. Furthermore, multiple immunofluorescence staining after 7 days of culture revealed no notable disparity in cell count and collagen components between the two groups; however, cell morphology in the GelMA+ HA group displayed significant elongation and clustering. Conclusion:The GelMA+ HA hydrogel exhibits enhanced mechanical properties and reduced swelling ratio, rendering it suitable for the fabrication of complex structures. Additionally, it demonstrates excellent cell compatibility.

Objective:The aim of this study is to analyze the clinical characteristics and genetic variants of a late-onset auditory neuropathy pedigree caused by maternally inherited- mitochondrial mutation.Methods:A male proband who presented with bilateral sensorineural hearing loss at Henan Children′s Hospital in September 2023 was chosen, along with his family members (4 generations, 20 individuals) as the study subjects. Data from this pedigree were collected, organized, and analyzed for clinical genetic characteristics. Medical histories were obtained from family members, pedigree charts were drawn, audiological, imaging, and physical examinations were conducted. Pathogenic genes and mutations were screened using high-throughput sequencing. Sanger sequencing was employed for variant confirmation and segregation validation in the family.Results:In this family, a total of 12 members (10 members collected) had sensorineural hearing loss, characterized by late-onset hearing impairment with an onset age ranging from 9 to 30 years. The patients exhibited poor speech recognition rates, and audiometric examinations are consistent with auditory neuropathy. There was no history of ototoxic drug use. High-throughput sequencing identified the variant NC_012920.1:m.7471dup in the mitochondrial MT-TS1 gene as the pathogenic variant. Sanger sequencing results confirmed that the pathogenic gene mutation site perfectly co-segregated with the auditory neuropathy phenotype in this family. According to the classification criteria and guidelines for genetic variations by the American College of Medical Genetics and Genomics, the variant was classified as a pathogenic mutation. Conclusion:The mitochondrial MT-TS1 gene mutation m.7471dup is considered to be the pathogenic cause in this late-onset auditory neuropathy pedigree.

Objective:Objective The potential of a three- dimensional bioprinted cell-laden gelatin methactyloyl (GelMA)+ hyaluronic acid (HA) composite bioink in tissue engineering was assessed by evaluating cell viability, scaffold morphology, and cell compatibility.Methods:Rabbit chondrocytes were isolated and cultured. Composite hydrogels were prepared using GelMA and HA, and their applicability in tissue engineering was assessed by evaluating physicochemical properties, cytocompatibility, and printability. The swelling and mechanical properties of 100g/L GelMA inks as the control group, and 100g/L GelMA+ 20g/L HA inks as the experimental group were assessed following photocrosslinking of the cylindrical model. The printing resolution of the GelMA/HA mesh scaffold loaded with chondrocytes was evaluated based on appearance and expansion ratio. Cell viability was determined using cell live/dead test after 14 days, while cytocompatibility was observed through in vitro microscopy and multiple immunofluorescence staining after 7 days. GraphPad Prism 8.0 was utilized for data visualization and statistical analysis. Independent-samples t-test was employed to compare differences among groups. A P-value less than 0.05 was considered statistically significant. Results:The swelling ratio of GelMA group was 10.57±0.40, which exceeded that of the GelMA+ HA group (7.63±0.61, P<0.05). The compressive elastic modulus of GelMA+ HA group measured (77.53±4.30) kPa, significantly surpassing that of the GelMA group [(25.60±5.70) kPa, P<0.05]. The extension ratio of GelMA was 2.59±0.33, while the experimental group recorded 2.66±0.12, with no statistically significant difference between them ( P>0.05). There were no notable disparities in cell viability between the two groups; both exhibited viabilities greater than 85%. On the initial day of culture, both groups exhibited intact structures, regular pores, and a substantial number of spherical cells. After 14 days of culture, the GelMA scaffold structure appeared blurred with nearly vanished pores, while large live cells were visible. The GelMA+ HA scaffold structure was slightly more relaxed with relatively intact pores and a significant presence of live cells. Furthermore, multiple immunofluorescence staining after 7 days of culture revealed no notable disparity in cell count and collagen components between the two groups; however, cell morphology in the GelMA+ HA group displayed significant elongation and clustering. Conclusion:The GelMA+ HA hydrogel exhibits enhanced mechanical properties and reduced swelling ratio, rendering it suitable for the fabrication of complex structures. Additionally, it demonstrates excellent cell compatibility.

Objective:The aim of this study is to analyze the clinical characteristics and genetic variants of a late-onset auditory neuropathy pedigree caused by maternally inherited- mitochondrial mutation.Methods:A male proband who presented with bilateral sensorineural hearing loss at Henan Children′s Hospital in September 2023 was chosen, along with his family members (4 generations, 20 individuals) as the study subjects. Data from this pedigree were collected, organized, and analyzed for clinical genetic characteristics. Medical histories were obtained from family members, pedigree charts were drawn, audiological, imaging, and physical examinations were conducted. Pathogenic genes and mutations were screened using high-throughput sequencing. Sanger sequencing was employed for variant confirmation and segregation validation in the family.Results:In this family, a total of 12 members (10 members collected) had sensorineural hearing loss, characterized by late-onset hearing impairment with an onset age ranging from 9 to 30 years. The patients exhibited poor speech recognition rates, and audiometric examinations are consistent with auditory neuropathy. There was no history of ototoxic drug use. High-throughput sequencing identified the variant NC_012920.1:m.7471dup in the mitochondrial MT-TS1 gene as the pathogenic variant. Sanger sequencing results confirmed that the pathogenic gene mutation site perfectly co-segregated with the auditory neuropathy phenotype in this family. According to the classification criteria and guidelines for genetic variations by the American College of Medical Genetics and Genomics, the variant was classified as a pathogenic mutation. Conclusion:The mitochondrial MT-TS1 gene mutation m.7471dup is considered to be the pathogenic cause in this late-onset auditory neuropathy pedigree.

Objective:To study the risk factors of acute stroke within 1 year after hip fracture in the elderly and its effect on prognosis.Methods:From January 2018 to December 2020, 278 elderly hip fracture patients undergoing surgery were retrospectively analyzed, including 101 males and 177 females, aged from 60 to 99 years with an average of(78.9±8.7)years.According to whether acute stroke occurred within 1 year after operation, the patients were divided into stroke group and non-stroke group.A multivariate Logistic regression was used to evaluate the risk factors for acute stroke within 1 year after hip fracture, and the prognosis was analyzed.Results:Acute stroke occurred in 28 patients(10.1%)within 1 year after operation, and the peak of stroke onset occurred in the third months after operation.Patients in the stroke group were older, and had a higher proportion of hypertension, arrhythmia, previous stroke history, and use of anticoagulant or antiplatelet drugs before fracture( P<0.05 for all). Multivariate Logistic regression analysis showed that advanced age( OR=1.078, 95% CI=1.007-1.153, P=0.030), male( OR=2.643, 95% CI=1.060-6.742, P=0.037)and previous stroke history( OR=12.202, 95% CI=4.662-31.940, P<0.001)were independent risk factors for stroke in elderly patients with hip fracture within 1 year after operation.The 1-year mortality, complication rate and readmission rate in the stroke group were significantly higher than those in the non-stroke group( P<0.05 for all). Conclusions:The incidence of stroke is high in elderly patients with hip fracture within 1 year after operation.Older age, male, and previous stroke history were independent risk factors for acute stroke.The prognosis of stroke was poor in elderly patients with hip fracture, and the 1-year mortality, complication and readmission rates were high.

Objective:To introduce our experience in the treatment of infection related to lower long bone fracture in adults.Methods:From January 2017 to December 2020, 31 adult patients with infection related to lower long bone fracture were treated at Department of Orthopaedics, the 7th Medical Center, General Hospital of the People's Liberation Army. They were 20 males and 11 females with an age of (35.7±16.7) years. There were 9 cases of acute infection, 3 cases of delayed infection and 19 cases of late infection. They were treated according to their stage of infection, respectively, by retaining or removing the internal fixation, debridement, bone grafting and bone lengthening. They were followed up regularly for at least 12 months to observe their symptoms, signs, indexes of imaging and blood tests. Paley score for fracture union was recorded at the last follow-up.Results:All the 31 patients were followed up for 13.0(13.0, 31.0) months. Of the 9 patients with acute infection, 6 retained the implant, 1 removed the implant for dressing change due to intolerability and 2 removed the implant due to unsatisfactory infection control. Of the 3 patients with delayed infection, 1 retained the implant and 2 removed the implant because of unsatisfactory infection control. Of the 19 patients with delayed infection, 5 were treated with local bone graft, 6 with Masqulet technique and 8 with bone transfer following debridement and implant removal. All patients were cured without recurrence of infection. According to Paley's scoring, 25 cases were excellent, 5 were good, and 1 was fair.Conclusions:Treatment of infection related to lower long bone fracture in adults should be carried out according to its clinical stage. For acute and delayed infection, implants should be preserved as much as possible; for chronic infection, implants should be removed to perform bone and soft tissue reconstruction after thorough debridement. Personalized diagnosis and treatment protocols can lead to satisfactory clinical results.

Objective:To investigate the role of the NOD-like receptor thermal protein domain associated protein 3(NLRP3)inflammasome and its downstream interleukin(IL)-1β, IL-6, and IL-18 in the pathogenesis of antineutrophil cytoplasmic antibody-associated vasculitis(AAV) in children.Methods:A retrospective study was conducted.Specifically, the localization and expression of the NLRP3 inflammasome in renal tissues of 22 children who were diagnosed with primary AAV and underwent renal biopsy in the Department of Pediatric Nephrology and Rheumatology, the First Affiliated Hospital of Sun Yat-Sen University from September 2003 to September 2020 were detected by the immunohistochemical method.The IL-1β, IL-6 and IL-18 levels in serum and urine were measured by enzyme-linked immunosorbent assay.The measurement data conforming to normal distribution were compared by the t test between two groups and by the single factor ANOVA test among multiple groups.The measurement data that did not conform to normal distribution were compared by the Wilcoxon signed rank sum test.Classification variables were examined by the χ2 test. Pearson correlation coefficient or Spearman rank correlation coefficient were used to analyze the correlation among variables. Results:NLRP3 was widely expressed in the tubulointerstitium, and the expression level in the active group was higher than that in the control group, the semi-quantitative scores of NLRP3 in the renal tubule and glomeruli in the active group were higher than those in the control group ( F=0.859, 8.320, all P<0.05). In the active group, the semi-quantitative score of NLRP3 in the renal tubule was higher than that in the glomeruli( F=3.517, P<0.05). The semi-quantitative score of NLRP3 in the renal tubule was positively correlated with the pediatric vasculitis activity score at renal biopsy ( r=0.471, P=0.027)and negatively correlated with the estimated glomerular filtration rate at renal biopsy ( r=-0.548, P=0.008)in the active group.The serum IL-1β, serum IL-18 and urinary IL-6 levels in the active group were higher than those in the remission group and the control group ( F=16.449, 16.449, 0.637, 29.891, 27.612, 7.464, all P<0.05). The serum IL-18 level in the remission group was higher than that in the control group( F=18.671, P<0.05). In the active group, a positive correlation was found between the serum IL-1β level and the semi-quantitative score of NLRP3 in the renal tubule( r=0.805, P=0.002), between the serum IL-6 level and the C-reactive protein level at renal biopsy ( r=0.728, P=0.017), and between the urinary IL-6 level and the crescent proportion at renal biopsy ( r=0.677, P=0.032). The serum IL-18 level in the active group was positively correlated with the semi-quantitative score of NLRP3 in the renal tubule, pediatric vasculitis activity score and glomerular sclerosis proportion at renal biopsy, and negatively correlated with the estimated glomerular filtration rate at renal biopsy ( r=0.644, 0.612, 0.695, -0.577, all P<0.05). The urinary IL-18 level was positively correlated with the complement C 4 level at renal biopsy ( r=0.855, P<0.05). Conclusions:The NLRP3 inflammasome and its downstream IL-1β, IL-6, and IL-18 may be involved in the pathogenesis and progression of AAV, and can be used as one of the reference indicators for disease activity assessment.

Objective To study the effect of combined transplantation of pancreatic islets and hepatocytes on the treatment of diabetic rats and the possibility on hepatocytes inducing islet allograft tolerance. Methods Forty diabetic SD rats were randomly divided into 4 groups: normal control group,diabetic control group, pancreatic islet grafted group,and hepatocyte and pancreatic islet transplanted group. The pancreatic islets of fetal SD rats were implanted into the gastric subserosa of recipients. The alteration of diabetes and immune status were observed. Results There were 58.8% (20/34) diabetic rats cured after pancreatic islets transplantation. The survival time in the combined grafted group was longer than that in the pancreatic islet grafted group ( P