Recombinant Human Collagen Type III Improves Hypertrophic Scarring by Regulating the Ratio of Type I/III Collagen.

Hypertrophic scar development is a complication associated with wound healing, impacting local appearance and function. The type I/III collagen ratio affects the extent of hypertrophic scarring; a reduced ratio can ameliorate this. In this study, recombinant human collagen type III was developed. Liquid chromatography-tandem mass spectrometry was used to determine its amino acid sequence and confirm its high level of homology with natural human type III collagen. Recombinant human collagen type III displayed no cytotoxicity and did not confer skin irritation and sensitization. Immunofluorescence and western blot analyses of histidine following incubation with fibroblasts suggested cell entry of recombinant human collagen type III. Furthermore, recombinant human collagen type III promoted the synthesis of the natural type III collagen in fibroblasts, resulting in a more obvious increase of type III collagen content in fibroblasts than that of type I collagen, and then decreased the ratio of type I/III collagen. The results of 5-ethynyl-2'-deoxyuridine staining assay suggested enhanced fibroblast proliferation. Following local injection of recombinant human collagen type III, rabbit ear scarring was significantly reduced after 60 days. Vancouver Scar Scale evaluation showed that all index scores were significantly reduced. Western blotting and Picro-Sirius red staining showed that the natural type III collagen increase in scar tissue was greater than that of type I collagen, decreasing the type I/III ratio. In summary, recombinant human collagen type III can be taken up by fibroblasts and promote natural collagen synthesis-especially that of type III-thereby reducing the type I/III ratio and improving hypertrophic scarring.

Characterization of Bacterial Community Structure Dynamics in a Rat Burn Wound Model Using 16S rRNA Gene Sequencing.

Burns destroy the skin barrier and alter the resident bacterial community, thereby facilitating bacterial infection. To treat a wound infection, it is necessary to understand the changes in the wound bacterial community structure. However, traditional bacterial cultures allow the identification of only readily growing or purposely cultured bacterial species and lack the capacity to detect changes in the bacterial community. In this study, 16S rRNA gene sequencing was used to detect alterations in the bacterial community structure in deep partial-thickness burn wounds on the back of Sprague-Dawley rats. These results were then compared with those obtained from the bacterial culture. Bacterial samples were collected prior to wounding and 1, 7, 14, and 21 days after wounding. The 16S rRNA gene sequence analysis showed that the number of resident bacterial species decreased after the burn. Both resident bacterial richness and diversity, which were significantly reduced after the burn, recovered following wound healing. The dominant resident strains also changed, but the inhibition of bacterial community structure was in a nonvolatile equilibrium state, even in the early stage after healing. Furthermore, the correlation between wound and environmental bacteria increased with the occurrence of burns. Hence, the 16S rRNA gene sequence analysis reflected the bacterial condition of the wounds better than the bacterial culture. 16S rRNA sequencing in the Sprague-Dawley rat burn model can provide more information for the prevention and treatment of burn infections in clinical settings and promote further development in this field.

Population-based survey of prevalence, causes, and risk factors for blindness and visual impairment in an aging Chinese metropolitan population.

AIM: To assess the prevalence, causes, and risk factors for blindness and visual impairment among elderly (≥60 years of age) Chinese people in a metropolitan area of Shanghai, China. METHODS: Random cluster sampling was conducted to identify participants among residents ≥60 years of age living in the Xietu Block, Xuhui District, Shanghai, China. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) were checked by the Early Treatment Diabetic Retinopathy Study (ETDRS) visual chart. All eligible participants underwent a comprehensive eye examination. Blindness and visual impairment were defined according to World Health Organization (WHO) criteria. RESULTS: A total of 4190 persons (1688 men and 2502 women) participated in the study, and the response rate was 91.1%. Based on PVA, the prevalence of blindness was 1.1% and that of visual impairment was 7.6%. Based on BCVA, the prevalence of blindness and visual impairment decreased to 0.9% and 3.9%, respectively. Older (≥80 years of age) women, with low educational levels and smoking habits, exhibited a significantly greater chance for blindness and visual impairment than did those with high educational levels and no smoking habits (P<0.05). Based on PVA and BCVA, the main causes of blindness were cataract, myopic maculopathy, and age-related macular degeneration (AMD). CONCLUSION: Our findings help to identify the population in need of intervention, to highlight the need for additional eye healthcare services in urban China.

[Analyses on the relative factors regarding diabetic nephropathy].

OBJECTIVE: To analyze the related factors regarding diabetic nephropathy (DN). METHODS: A total number of 756 diabetic patients from 2009 to 2011 were analyzed retrospectively. Three groups were formed according to the urinary albumin excretion rates (UAER). Patients with UAER < 20 µg/min was grouped to group A, with UAER from 20 to 200 µg/min as group B, and the others with UAER ≥ 200 µg/min was grouped to group C. General characteristics and laboratory parameters were then compared and related factors of DN analyzed. RESULTS: The constituent ratio of nephropathy was 30.2% (228/756). Patient's age, duration of disease, both diastolic and systolic blood pressure of group A were significantly higher than the non-DN group (A) (P < 0.05). Patient's age, disease duration, both diastolic and systolic blood pressure of group C were (64.08 ± 11.71) years, (14.67 ± 7.34) years, (87.43 ± 14.36) mm Hg, (152.45 ± 18.48) mm Hg, respectively, with statistically significant difference (P < 0.05) between group C and group B. FPG, TG, TC, HDL-C, UA, HbA1c, FINS, FCP of group B were (9.27 ± 3.06) mmol/L, (1.98 ± 0.37) mmol/L, (5.01 ± 1.08) mmol/L, (1.05 ± 0.35) mmol/L, (312.78 ± 39.83) mmol/L, (9.33 ± 1.47)%, (11.45 ± 7.83) µU/ml, (509.73 ± 132.78) pmol/L respectively, with significant difference (P < 0.05) between group B and group A. FPG, TG, HDL-C, UA, FINS, FCP of group C were (9.29 ± 3.12) mmol/L, (2.02 ± 0.36) mmol/L, (1.04 ± 0.27) mmol/L, (389.72 ± 46.32) mmol/L, (11.09 ± 8.29) µU/ml, (575.77 ± 143.29) pmol/L respectively, with significant difference (P < 0.05) between group C and group A. UA, FINS, FCP were found with significant differences (P < 0.05) between group C and group B. Data from multivariate logistic regression showed that DNs were related with disease duration, BMI, systolic blood pressure, HbAlc, FPG, UA. CONCLUSION: DN was closely related to the duration, age, blood sugar, blood lipids, blood pressure, uric acid levels of the disease.