BACKGROUND:Along with the widespread application of biodegradable materials in the field of medicine and the in-depth research of biomechanics,the drawbacks of traditional medical metal materials are increasingly appearing.In recent years,researchers at home and abroad focus on biodegradable materials that are represented by high molecular polymer to seek new breakthroughs in the field of spinal instability.OBJECTIVE:To investigate biomechanical changes of polylactic acid-polyglycolic acid (PLGA) lumbar interbody fusion cage in the body and discusses its feasibility for treating segmental instability of the spine.METHODS:Forty-two healthy pigs (9 months old) were randomly divided into two groups (n=21),and L4/5 intervertebral disc nucleus pulposus was removed in all animals.In experimental group,PLGA lumbar interbody fusion cage filled with broken bone was implanted;and in control group,autologous bone was implanted.X-ray was performed to observe the fusion of operation segments at 4,12 and 72 weeks postoperatively.Feasibility of fibrous fusion was measured by biomechanical test.Histologically,bone graft fusion at the surgical site and material degradation were detected.RESULTS AND CONCLUSION:(1) Imaging examination:Bone graft fusion in two groups was not visible at 4 weeks after operation.Evidence of increasing fusion was found in the experimental group at 12 weeks after operation;a visible part of the bone bridge was found in the control group,in which there was one case of fusion.Degradation of the fusion cage with one case of fusion in experimental group was found after 72 weeks after operation,and two cases of fusion in the control group.(2) Biomechanical test:There was no difference in the spinal range of motion between the two groups in different states at 4 weeks after operation (P ＞ 0.05).The spinal range values of motion at most of the states at 72 weeks after operation were significantly lower than those at 4 weeks after operation.(3) Cell histology observation:With the passage of time,the materials in the experimental group degraded gradually;new bone grew slowly and then fast,with bone fusion step by step.Fusion results were similar in the two groups.Our experimental findings indicate that the PLGA lumbar fusion cage has good biocompatibility.In addition to the individual state (left flexion),the mechanical properties of the fusion cage are similar to that of autogenous bone,and the fusion cage enables the segmental reconstruction of the pig spine to the maximum extent.

Forensic science is looking for clues at a crime scene in order to reconstruct the crime scene.Classic clues include DNA and fingerprints.Forensic microbiology is a branch of forensic medicine that uses microbes as clues,providing us information about lifestyle,circadian rhythms,geographic locations,postmortem intervals,cancers,and oral or systemic diseases.Oral cavity,as the place with the second largest number of microorganisms,can provide researchers with microbial information of each ecological niche,and assist in the prediction,diagnosis and monitoring of oral or systemic diseases.This paper reviews the composition of oral microbiome,the application in oral diseases,systemic diseases and forensic medicine,with the aim of providing some references for the development of forensic microbiology based on oral microbiome.

Objective:To investigate the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with rosacea, and to analyze the relationship between breath test results and the occurrence of rosacea.Methods:Patients with rosacea were enrolled from the outpatient department of Xiangya Hospital from March 2022 to June 2023. The methane-hydrogen breath test was used to detect intestinal levels of methane and hydrogen in all patients to investigate the prevalence of SIBO. The basic information, clinical symptoms and severity, quality of life scores, gastrointestinal symptoms, and past medical history of the patients were collected. Statistical analysis was carried out by using the chi-square test, nonparametric test and multivariate logistic regression models to investigate the relationship between SIBO and the occurrence of rosacea.Results:A total of 116 patients with rosacea completed the methane-hydrogen breath test. They were aged 18 to 56 years (median [ Q1, Q3]: 25 [22, 33] years), and included 7 males (6.0%) and 109 females (94.0%) ; there were 43 cases (37.1%) of erythematotelangiectatic rosacea, and 73 (62.9%) of papulopustular rosacea. As the breath test showed, 94 patients were diagnosed with SIBO (81.0%, 95% CI: 72.7% - 87.7%) based on the breath tests, 84 showed positive hydrogen breath test results (72.4%, 95% CI: 63.3% - 80.3%), and 47 had positive methane breath test results (40.5%, 95% CI: 31.5% - 50%). Among the 67 patients with moderate to severe erythema, 33 (49.3%) showed positive methane breath test results, and 14 of 49 (28.6%) patients with mild erythema showed positive methane breath test results, with a rate difference of 20.7% ( P = 0.025, 95% CI: 13.9% - 27.5%) ; there were no significant differences in the positive rates of SIBO and hydrogen breath test results between the patients with moderate to severe erythema and those with mild erythema (both P > 0.05). No significant differences were observed in the age, gender, clinical subtypes, severity of papulopustules, flushing and burning sensation, or rosacea quality of life index scores between the SIBO-positive and -negative groups, between hydrogen-positive and -negative groups, and between methane-positive and -negative groups (all P > 0.05). Multivariate logistic regression analysis showed that methane positivity on breath test was associated with the severity of erythema in rosacea ( OR = 2.495, 95% CI: 1.102 - 5.649, P < 0.05) . Conclusions:The prevalence of SIBO was relatively high in the patients with rosacea. However, only the positive rate of methane breath test differed between the rosacea patients and non-rosacea controls, and there was some correlation between methane positivity on breath test and increased severity of rosacea erythema.

Background: Obesity is an independent risk factor for gastroesophageal reflux disease (GERD), but the mechanism remains unclear. There are few studies focusing on the effectiveness of standard dose proton pump inhibitor (PPI) in treating obese GERD patients. Aims: To investigate the effect of obesity on esophageal motility and acid reflux in GERD patients and the efficacy of standard dose PPI in treating obese GERD patients. Methods: Patients who were initially diagnosed as GERD and met the inclusion criteria from January 2017 to October 2021 at Anhui Provincial Hospital were included in this study. The results of esophageal high-resolution manometry and 24 h esophageal pH-impedance monitoring before PPI treatment in patients with normal body mass index (BMI) and obesity (BMI≥28.0 kg/m