[Research advances on the role and mechanism of chitosan-based wound dressing in wound healing].

The skin is the first barrier to maintain the stability of internal environment of the body and resist harmful factors of external environment, and is easily damaged because of various external factors. When full-thickness skin defects reach a certain level, it is difficult for the skin to repair itself, so wound dressings are needed to promote wound healing. Seeking an ideal dressing that can promote wound healing has long been a hot research topic. Chitosan is a unique biopolysaccharide polymer with good biocompatibility, biodegradability, antibacterial activity, and thermal stability, which has great potential in the development and application of wound dressings. Based on the introduction of properties of chitosan, this article reviews the role and mechanism of chitosan-based wound dressings in wound healing, and summarizes the hemostatic effect, antibacterial effect, delivery effect, and tissue regeneration promotion effect of chitosan, aiming to provide a certain reference for the research and development of new chitosan-based wound dressings in the future.

[Effect of dNLR and LIPI scores on the prognosis of elderly patients with non-surgical treatment of non-small cell lung cancer].

Objective: To investigate the effects of derived neutrophil to lymphocyte ratio (dNLR) and lung immune prognostic index (LIPI) score on the overall survival (OS) of non-surgical elderly non-small cell lung cancer (NSCLC) patients. Methods: Clinical and pathological data of NSCLC patients in Hebei General Hospital from January 2014 to June 2018 were collected retrospectively. The dNLR value was calculated based on the results of blood routine before treatment, and the optimal cut-off value of dNLR was obtained by ROC curve. The patients were divided into low dNLR level group and high dNLR level group based on the optimal dNLR cut-off value. The groups were classified as good, intermediate and poor based on the LIPI score consisting of lactate dehydrogenase (LDH) and dNLR tested before treatment. The Kaplan-Meier method and Log rank test were used for survival analysis, and the Cox risk proportional regression model was used for analysis of prognostic influences. Results: The area under the ROC curve for dNLR predicting prognosis in non-surgical elderly NSCLC patients was 0.591 (95% CI: 0.491, 0.692; P=0.093). The optimal cut-off value for dNLR predicting prognosis in elderly NSCLC patients was 2.515, with a sensitivity of 45.5% and a specificity of 81.8%. The gender, BMI, pathological type and degree of tumor differentiation were associated with dNLR levels (P<0.05). The median survival times were 16 and 10 months for patients in the low dNLR level group (dNLR<2.51) and high dNLR level group (dNLR≥2.51), respectively (P<0.001), and 15, 10 and 6 months for patients with good, intermediate and poor LIPI scores, respectively (P<0.001). The age, gender, smoking, pathological type, tumor differentiation, clinical stage, BMI, dNLR level, LDH level and LIPI scores were all associated with patient prognosis (P<0.05), and age≥76 years, tumor differentiation and clinical stage Ⅲ and Ⅳ were independent factors influencing patient prognosis (P<0.05). Conclusion: No matter what treatment measures are taken, dNLR level and LIPI score are related to patients' prognosis, and non-surgical elderly NSCLC patients with high dNLR level and poor LIPI score before treatment have worse prognoses.

[Correlation study between changes in intestinal microflora structure and immune indexes in newly treated patients with pulmonary tuberculosis].

To explore the correlation between the changes of the intestinal flora of newly treated pulmonary tuberculosis patients and the immune indicators of the body, and to provide a reference for the prevention and treatment of pulmonary tuberculosis. A single-center and case-control study was adopted. From October 2020 to April 2021, 43 patients with newly diagnosed tuberculosis in the Department of Tuberculosis, Affiliated Changsha Central Hospital,University of South China were selected as the control group. 43 cases of newly treated pulmonary tuberculosis (PTB), 43 healthy control (HC) during the same period, collected fresh feces and whole blood of subjects, and used Illumina Hiseq high-throughput sequencing technology to analyze 16S of all microorganisms in feces The V4 region of rRNA was amplified and sequenced, and the structure of the intestinal flora was analyzed by QIIME software. Use flow cytometry to determine the subject's immune indicators (CD3+, CD4+, CD8+, CD4+CD25+CD127-Treg, CD14+CD16+, CD14+CD16-), and analyze the changes in intestinal flora and immune function in newly treated pulmonary tuberculosis patients Inherent connection. The χ² test, t test, and Wilcox rank sum test were used to analyze the differences in age, gender, α diversity, and relative abundance of the two groups of people. Compared with the HC group, the alpha diversity of the intestinal flora in the PTB group decreased (shannon index: t=3.906, P=0.000 2; simpson index: Z=553, P=0.004 7; chao1 index: t=5.395, P=0.000 0). ß diversity analysis showed that there were significant differences in the structure of the intestinal flora between the two groups (P=0.000). Species difference analysis showed that at the phylum level, the relative abundance of Firmicutes in the PTB group was significantly lower than that in the HC group (Z=486.0, P=0.000 5). At the genus level, there are 15 different bacterial genera between the two groups. In the PTB group, bifidobacterium, enterococcus, lactobacillus, anaerostipes, the relative abundance of the above 5 genera of veillonella is higher than that of the HC group (P<0.05); Butyricimonas, clostridium, and broutella (blautia), coprococcus, dorea, lachnospira, roseburia, faecalibacterium, ruminococcus, the relative abundance of 10 bacterial genera including dialister was lower than that of the HC group (P<0.05). Comparison of immune indexes between groups showed that CD14+CD16+monocytes (%) in the PTB group were higher than those in the HC group (t=2.456, P=0.001 6<0.05), while CD14+CD16-monocytes (%) were lower than HC (t=-4.368, P=0.000<0.05), while the differences in CD3+, CD4+, CD8+, CD4+/CD8+and Treg (CD4+CD25+CD127-) were not statistically significant (P>0.05). Spearman correlation analysis showed that Firmicutes in the PTB group was negatively correlated with CD4+/CD8+, CD14+CD16+(r=-0.218, P=0.048; r=-0.245, P=0.025), and positively correlated with CD14+CD16-Correlation (r=0.250, P=0.022); At the genus level, Faecalis is positively correlated with CD4+/CD8+and CD4+(r=0.250, P=0.023; r=0.258, P=0.019); Rosella and CD3+, CD8+and CD14+CD16-are positively correlated (r=0.27, P=0.024; r=0.219, P=0.046; r=0.027, P=0.039), and negatively correlated with CD14+CD16+(r=-0.280, P= 0.01). Changes in the structure of the intestinal flora of newly treated pulmonary tuberculosis patients may be one of the influencing factors of the immune function of the body. Targeted optimization of the structure of the intestinal flora and improvement of the body's immunity may be used as an effective auxiliary treatment for pulmonary tuberculosis.

Research Progress of Metabolomics in Forensic Pathology.

ABSTRACT: Metabolomics is an interdisciplinary subject that rose in the post-genomic era, which focuses on quantitative study of the response of living organisms to outside stimulation and pathophysiological changes, as well as multiple dynamic response of the level of in vivo metabolites caused by genetic mutation. It is extensively used in basic research of system biology, materia medica, clinical medicine, etc. In the forensic field, metabolomics mainly focuses on forensic toxicology, but with the generalization of certain techniques, it's foreseeable that metabolomics has a broad research prospect in forensic pathology. This article summarizes the major analysis techniques and methods of metabolomics, describes the research status of metabolomic techniques in the field of forensic pathology application research, including postmortem interval and death cause. Moreover, this article summarizes and discusses the potential applicable areas, in order to provide reference for relative research and application.

[Analysis of transcanal endoscopic ear surgery for antrum cholesteatoma].

Objective:To report surgical techniques, outcomes, clinical experience and application key point of transcanal endoscopic ear surgery for tympanic antrum cholesteatoma. Method:Data from 27patients who underwent transcanal endoscopic ear surgery for tympanic antrum cholesteatoma were retrospectively analyzed. Removal of tympanic antrum cholesteatoma and tympanoplasty were individualized. Patients were followed up at postoperative 1, 3 and 6month. Result:There was no failure of tympanal and canal wall reconstruction. The mean preoperative air conduction threshold was（50.33±7.34） dB HL, compared to（29.59±5.56） dB HL postoperatively P=0.00）. The mean preoperative air-bone gap was（29.13±4.70） dB, compared to（12.25±4.98） dB postoperatively（P=0.00）. There was no complication, recurrence, residual tympanic antrum cholesteatoma or secondary surgery needed. Conclusion:Stand alone transcanal endoscopic ear surgery is a safe and effective for tympanic antrum cholesteatoma.

Research Progress on Age Estimation Based on DNA Methylation.

ABSTRACT: Age estimation is of great significance in the fields of criminal investigation and forensic identification. It can provide the age information of individuals to judicial departments to facilitate the development of judicial work. In recent years, age estimation methods expanded from the morphological level to the molecular biology level. With the rapid development of epigenetics represented by DNA methylation, and the advancement of DNA methylation detection technology together with the detection platform, many age estimation methods based on DNA methylation biomarkers, or using several biological fluids, such as blood, blood stains, saliva, semen stains, etc. are developed. Currently, researches related to age estimation based on DNA methylation are relatively widely carried out. This paper summarizes the researches on age estimation based on DNA methylation, in order to provide references for related studies and forensic applications.

[Clinical value of V-shaped concealed incision in parotid benign tumors].

Objective:The aim of this study is to explore the clinical value of V-shaped concealed incision in parotid benign tumors surgery.Method:Thirty-two patients with benign parotid tumors who were hospitalized from January 2016 to December 2017 were selected. All patients were treated with a V-shaped incision approach, starting from the anterior dermatoglyph of the tragus,extending downward to the earlobe and backward to the posterior earlobe, which formed an intersection point of the earlobe for parotid benign tumors,superficial lobectomy and facial nerve dissection.The greater auricular nerve and parotid masseter fascia were preserved,and the occult incision and prognosis were followed up for 1 year.Result:①All patients achieved primary healing without salivary fistula and infection.The visual analogue scale (VAS) score of 32 patients with postoperative aesthetic satisfaction was 0.②Of the 32 patients,only 2 had temporary facial paralysis after operation, which returned to normal after 1 and 2 months,while the rest had no facial paralysis symptoms.③The posterior and inferior auricular branches of the greater auricular nerve were preserved in all the 32 patients, and the sensation of the lobe was numb to varying degrees after the operation. After 3 months,the sensation recovered completely.④Two patients had skin flushing and sweating on the affected cheek during masticatory exercise, while the others had no Frey syndrome. ⑤Five patients who were repaired with sternocleidomastoid muscle flaps during operation were reexamined one year after operation.There was no significant asymmetric depression on the operative side compared with the healthy side.⑥All the 32 patients were followed up for 1 year without recurrence.Conclusion:The V-shaped concealed incision is performed for benign tumor resection of the parotid gland. The incision approach is concealed and the scar is not obvious.The surgical field is clear and easy to operate.It is not easy to damage the facial nerve and the ear nerve. After the operation,the patient has a satisfactory facial shape.The parotid gland secretion function is basically normal,which is superior to the traditional S-shaped incision and has good clinical application value.

[Clinical observation of attic retraction pocket by otoendoscopes].

Objective:To explore the clinical effect, key points and techniques of otoendoscopic surgery in patients with attic retraction pocket. Method:Data of 25 patients (25 ears) of chronic suppurative otitis media who treated with transcanal endoscopic ear surgery for attic retraction pocket were retrospectively analyzed. Patients were examined by otoendoscopes at postoperative 1, 3 and 6 month，respectively. Patients were tested by pure tone audiometry，tympanometry test and high resolution CT of temporal bone at postoperative 6 month. Result:The healing rate of perforation was 100% in 25 patients (25 ears) at postoperative 1 month. There was no infection, tinnitus, vertigo, decrease of air-bone conduction hearing and other complications. All patients had good tympanic membrane shape, no perforation, no invagination or adhesion in tympanic membrane at postoperative 6 month.The mean preoperative air conduction threshold was (39.59±8.37)dB HL, while it was (26.21±7.51)dB HL at postoperative 6 month (t=8.265，P<0.01).The mean preoperative air-bone gap was (28.67±6.58)dB HL, while it was (13.63±7.33)dB HL at postoperative 6 month (t=11.862，P<0.01).The mean air conduction threshold and the mean preoperative air-bone gap were significantly improved compared with those preoperative (P<0.01). Tympanometry test was "A" type at postoperative 6 month. Conclusion:The treatment of attic retraction pocket by otoendoscopes through external auditory canal has the advantages of clear image, wide field of vision, simple operation, less trauma, short operation time, accurate effect, and can reduce the residual and recurrence of lesions.

Difference Analysis Based on 16S rRNA Sequencing of Different Soil Bacterial Communities.

ABSTRACT: Objective To study the structure and differences of bacterial communities in different soils, and to explore the effectiveness of 16S rRNA sequencing in identification of different soil. Methods Soil samples from 7 places in Shanghai were collected, then bacterial genomic DNA were extracted from them. The fragments of hypervariable region from 16S rRNA sequences were sequenced with high-throughput sequencing techniques. The results were quantified or visualized with bioinformatics software. The differences in diversity and abundance among the three kinds of bacterial communities in soil samples from grassland, forests and beaches were compared and analyzed. Results The statistical differences that existed among the alpha diversity indexes of bacterial communities in soil samples of grassland, forests and beaches had statistical significance. The relative abundance and diversity of bacterial communities in these three kinds of soil were significantly different. Grassland soil had higher Acidobacteria abundance, forest soil had higher Proteobacteria abundance, beach soil had higher Actinobacteria abundance. However, the differences in soil bacterial communities in artificial grasslands, natural grasslands and industrial district grasslands did not have statistical significance. Conclusion 16S rRNA sequencing can effectively distinguish different soils. This method may be able to provide clues for first crime scene inference in criminal cases.

[Transcanal endoscopic ear surgery for tympanosclerosis].

Objective:To report surgical techniques, outcomes, clinical experience and application key point of transcanal endoscopic ear surgery for tympanosclerosis. Method: Data from 25 patients (13 males and 12 females; aged 27-61 years, mean=48.8 years) who underwent transcanal endoscopic ear surgery for tympanosclerosis in our department from January 2016 to June 2017 were retrospectively analyzed. Removal of tympanosclerosis and tympanoplasty were individualized. Patients were followed up at postoperative 1, 3 and 6 month. Result: There were no failure of tympanal reconstruction by sandwich. The mean preoperative air conduction threshold was higher than that of postoperation ï¼»(51.12±16.03）dB HL and （31.64±12.76)dB HL, respectivelyï¼½(P<0.01). The mean preoperative air-bone gap was significantly increased compared to that of postoperation ï¼»(30.33±10.12）dB and （14.19±8.97）dB,respectivelyï¼½ (P<0.01). There were no complication, recurrence, residual tympanosclerosis or secondary surgery needed. Conclusion: Stand alone transcanal endoscopic ear surgery was a safe and effective method for tympanosclerosis.

[Pathological analysis and treatments of neck infection induced by congenital pyriform sinus fistula].

Objective:To identify the pathogenic bacteria of CPSF and their resistance to antibiotics,and guide the rational use of antibiotics therapy.Method:One hundred and thirty cases of deep neck infection whose imaging finding depicted patients with suspected as CPSF were enrolled in the study from January 2010 to June 2017.Specimens were collected from abscesses or other inflammatory lesions from all patients through a small incision or the external orifice on the skin of the neck.Result:A total of 108 strains of pathogens have been isolated from 88 patients (positive rate: 67.7%), among which the gram-positive bacteria accounted for 56.5%, gram-negative bacteria accounted for 43.5%. Streptococcus and Staphylococcus aureus (22.2%) were the most common pathogens among young patients (≤14 years old) (17.7%);Klebsiellapneumoniae (15.7%) were the most common pathogens among the patients over 14 years old. Separation of pathogenic bacteria have maintained a low resistance to most antibiotics. G+ bacteria is totally sensitive to quinupristin/dalfopristin and vancomycin; G-bacteria is totally sensitive to cefoperazone/Batan, piperacillin/tazobactam,imipenem.Conclusion:Most of pathogens come from upper respiratory tract in CPSF cases, and are mostly sensitive to ßlactamase.

A novel HLA class I allele: HLA-A*11:01:49.

The HLA-A*11:01:49 allele differs from A*11:01:01:01 by one synonymous nucleotide substitution at position 837.

[Research Progress of CircRNA and Its Application Prospect in Forensic Medicine].

Circular RNA （circRNA） is a type of noncoding RNA with tissue specificity and high stability, which forms a closed continuous loop and is abundantly expressed in tissue cells. According to recent research, the regulatory function of circRNA elucidating in the occurrence and development of disease shows a potential for diagnosing clinical disease and revealing disease mechanism. This paper reviews the biological characteristics, analysis methods of circRNA and its research progress in clinical application as biomarker, and outlooks its application in the field of forensic medicine.

Characterization of the novel HLA-B*40:01:31 allele.

The HLA-B*40:01:31 allele differs from B*40:01:01 by one nucleotide substitution at position 216.

A novel HLA-B allele: HLA-B*40:241.

The HLA-B*40:241 allele differs from B*40:01:01 by 1 nucleotide substitution at position 691.

A novel HLA class II allele, HLA-DQB1*03:73.

The HLA-DQB1*03:73 allele differs from DQB1*03:01:01:01 by 1 nucleotide substitution at position 209.

A novel HLA-B allele: HLA-B*40:242.

The HLA-B*40:242 allele differs from B*40:54 by 1 nucleotide substitution at position 190.

In Vitro and In Vivo Antibacterial Activities of Patchouli Alcohol, a Naturally Occurring Tricyclic Sesquiterpene, against Helicobacter pylori Infection.

This study further evaluated the in vitro and in vivo anti-Helicobacter pylori activities and potential underlying mechanism of patchouli alcohol (PA), a tricyclic sesquiterpene. In the in vitro assay, the capacities of PA to inhibit and kill H. pylori were tested on three standard strains at different pH values and on 12 clinical isolates. The effects of PA on H. pylori adhesion (and its alpA, alpB, and babA genes), motility (and its flaA and flaB genes), ultrastructure, and flagellation were investigated. Moreover, the H. pylori resistance to and postantibiotic effect (PAE) of PA were determined. Furthermore, the in vivo effects of PA on H. pylori eradication and gastritis were examined. Results showed that MICs of PA against three standard strains (pH 5.3 to 9) and 12 clinical isolates were 25 to 75 and 12.5 to 50 µg/ml, respectively. The killing kinetics of PA were time and concentration dependent, and its minimal bactericidal concentrations (MBCs) were 25 to 75 µg/ml. In addition, H. pylori adhesion, motility, ultrastructure, and flagellation were significantly suppressed. PA also remarkably inhibited the expression of adhesion genes (alpA and alpB) and motility genes (flaA and flaB). Furthermore, PA treatment caused a longer PAE and less bacterial resistance than clarithromycin and metronidazole. The in vivo study showed that PA can effectively eradicate H. pylori, inhibit gastritis, and suppress the expression of inflammatory mediators (COX-2, interleukin 1ß, tumor necrosis factor alpha, and inducible nitric oxide synthase [iNOS]). In conclusion, PA can efficiently kill H. pylori, interfere with its infection process, and attenuate gastritis with less bacterial resistance, making it a potential candidate for new drug development.