[Influence of porcine urinary bladder matrix and porcine acellular dermal matrix on wound healing of full-thickness skin defect in diabetic mice].

Objective: To compare the difference of pro-healing effect of porcine urinary bladder matrix (UBM) and porcine acellular dermal matrix (ADM) on full-thickness skin defect wounds in diabetic mice. Methods: Thirty-six type 2 diabetic BKS db/db mice aged 10 weeks were divided into UBM group and ADM group according to the random number table, with 18 mice in each group and preoperative molarity of non-fasting blood glucose higher than 16.6 mmol/L. A circular full-thickness skin defect wound with 6 mm in diameter was made on the back of each mouse, and porcine UBM and porcine ADM scaffolds were implanted into the wounds of both groups correspondingly. Immediately after operation and on post operation day (POD) 7, 14, and 28, wounds were observed generally. On POD 7, 14, and 28, 6 mice of each group were collected respectively to calculate the rate of wound epithelialization, and then the corresponding mice were sacrificed after calculation, and the wound tissue was harvested to make slices. Six slices of the mice in the 2 groups on POD 7 and 14 were respectively collected to stain with haematoxylin-eosin (HE), and 6 slices on POD 7 and 28 had Masson's staining, which were used to observe histopathological changes and scaffold degradation. On POD 7 and 14, 24 slices of each mouse in the 2 groups were collected respectively to detect alpha smooth muscle actin (α-SMA) and CD31 positive expression denoting the growth of myofibroblasts and neovessels respectively and observe the distribution and activation of macrophages with immunohistochemical staining. The wound tissue of mice in the 2 groups on POD 7 and 14 was harvested to detect mRNA expressions of fibroblast growth factor 2 (FGF-2), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and transforming growth factor ß(1) (TGF-ß(1)) by real-time fluorescence quantitative reverse transcription polymerase chain reaction. The sample number of above-mentioned indexes in each group at each time point was 6. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results: (1) General observation showed that integration of UBM scaffold into the wounds of mice in UBM group on most time points was superior, and integration of ADM scaffold into the wounds of mice in ADM group on most time points was inferior. On POD 28, epidermis still did not form in some region of scaffold surface of wounds of mice in ADM group, while wounds of mice in UBM group were completely epithelialized. On POD 7, 14, and 28, wound epithelialization rates of mice in UBM group were respectively (22.4±6.4)%, (68.6±12.4)%, and 100.0%, all significantly higher than (4.5±2.2)%, (23.6±4.6)%, and (64.2±13.2)% in ADM group (t=7.427, 9.665, 7.655, P<0.01). (2) HE staining and Masson's staining showed that a large number of cells appeared in wound scaffold of mice in UBM group on POD 7; cells distributed in the whole region of UBM scaffold on POD 14; dermal tissue with structure similar to normal skin formed in the wounds and the fibrous morph of UBM scaffolds disappeared on POD 28. Only a small number of cells appeared in inside of wound scaffolds of mice in ADM group on POD 7; on POD 14, cells were sparsely distributed in ADM scaffolds; on POD 28, the morph of originally robust collagen fiber of ADM scaffolds was still clear and visible. (3) On POD 7, a large number of accumulated myofibroblasts and neovessels appeared in the lower layers of scaffolds of wounds of mice in UBM group; on POD 14, evenly distributed myofibroblasts and neovessels appeared in the upper layers of UBM scaffolds, and most vessels were perfused. On POD 7 and 14, myofibroblasts were sparsely distributed in scaffolds of wounds of mice in ADM group with no or a few neovascular structures perfused unobviously. On POD 7 and 14, α-SMA positive expressions in scaffolds of wounds of mice in UBM group were significantly higher than those in ADM group (t=25.340, 6.651, P<0.01); CD31 positive expressions were also significantly higher than those in ADM group (t=34.225, 10.581, P<0.01). (4) On POD 7, a large number of macrophages appeared in the lower layers of scaffolds of wounds of mice in UBM group; on POD 14, macrophages infiltrated into the internal region of UBM scaffolds, and M2 polarization occured without M1 polarization. On POD 7, a small number of macrophages appeared in the bottom of scaffolds of wounds of mice in ADM group; on POD 14, macrophages were few in internal region of ADM scaffold, and neither M2 polarization nor M1 polarization occurred. (5) On POD 7 and 14, mRNA expressions of FGF-2, VEGF, PDGF, and TGF-ß(1) in the wound tissue of mice in UBM group were all significantly higher than those in ADM group (t=7.007, 14.770, 10.670, 8.939; 7.174, 7.770, 4.374, 4.501, P<0.01). Conclusions: Porcine UBM scaffold is better than porcine ADM in facilitating wound repair and dermis reconstruction of full-thickness skin defects in diabetic mice through the induction of myofibroblasts and macrophages immigration, the promotion of neovascularization and expression of pro-healing growth factors.

[Clinical effects of vacuum sealing drainage in the treatment of alkali burn wounds].

Objective: To preliminarily observe the clinical effects of vacuum sealing drainage (VSD) in the treatment of alkali burn wounds. Methods: From June 2016 to March 2020, 60 male patients with alkali burns who met the inclusion criteria and hospitalized in the Affiliated Hospital of Jiangnan University were recruited in this prospectively randomized control study. According to the random number table, silver sulfadiazine group and VSD group were both allocated with 30 patients, aged (36±8) and (35±10) years respectively; with total burn area of (7.2±2.0) % and (8.5±3.0) % total body surface area respectively. After admission, patients in silver sulfadiazine group were treated with conventional silver sulfadiazine dressing change once a day after debridement; patients in VSD group were given continuous VSD treatment after debridement, with the negative pressure setting at -10.67 kPa, and the negative pressure materials were replaced every 6 to 8 days. On treatment day 1, 4, and 7, the exudate from the wounds of patients in silver sulfadiazine group and the wound drainage fluid of patients in VSD group were collected, the pH value was measured by a portable pH meter, and the volume of exudate/drainage fluid was measured. After 7, 14, and 21 days of treatment, the wound healing rates of patients were calculated in the two groups. Before treatment and 7 days after treatment, venous blood was collected from the patients in the two groups to detect the serum level of tumor necrosis factor α (TNF-α) and interleukin 8 (IL-8). Within treatment day 14, Visual Analogue Scale was used to assess the pain score of patients in the two groups during each time of dressing change. The medical costs and discharge satisfaction scores of patients in the two groups were recorded. Data were statistically analyzed with analysis of variance for repeated measurement, t test, and Bonferroni correction. Results: (1) On treatment day 1, 4, and 7, the pH values of the drainage fluid of patients in VSD group were 9.75±0.59, 9.01±0.46, and 8.13±0.28, respectively, which were significantly higher than 9.35±0.62, 8.18±0.18, and 7.58±0.09 of exudate of patients in silver sulfadiazine group (t=2.03, 6.80, 7.56, P<0.05 or P<0.01). On treatment day 1 and 4, the volumes of drainage fluid of patients in VSD group were (553±83) and (239±65) mL respectively, which were significantly higher than (440±77) and (175±49) mL of exudate of patients in silver sulfadiazine group (t=3.44, 2.24, P<0.05). On treatment day 7, the volume of drainage fluid of patients in VSD group was (21±8) mL, which was significantly lower than (149±44) mL of exudate of patients in silver sulfadiazine group (t=-12.61, P<0.01). (2) After 7, 14, and 21 days of treatment, the wound healing rates of patients in VSD group were (39±6) %, (74±10) %, and (92±3) %, respectively, which were significantly higher than (25±3) %, (59±6) %, and (77±6) % in silver sulfadiazine group (t=7.07, 5.59, 7.09, P<0.01). (3) Before treatment, the serum levels of TNF-α and IL-8 of patients in the two groups were similar. After 7 days of treatment, the serum levels of TNF-α and IL-8 of patients in VSD group were significantly lower than those in silver sulfadiazine group (t=-8.75, -8.04, P<0.01). (4) The pain score during dressing change and medical cost of patients in VSD group were significantly lower than those in silver sulfadiazine group (t=-4.28, -7.56, P<0.01), while the discharge satisfaction score of patients in VSD group was significantly higher than that in silver sulfadiazine group (t=10.91, P<0.05). Conclusions: The application of VSD technology in clinical alkali burn wounds can effectively promote the removal of residual lye, alleviate the further damage of lye to skin tissue, shorten the wound healing time, effectively remove inflammatory mediators, reduce the pain of dressing change, decrease the total cost of treatment, and enhance satisfaction of patient.

Mechanical characterization of stomach tissue under uniaxial tensile action.

In this article, the tensile properties of gastric wall were investigated by using biomechanical test and theoretical analysis. The samples of porcine stomach strips from smaller and greater curvature of the stomach were cut in longitudinal and circumferential direction, respectively. The loading-unloading, stress relaxation, strain creep, tensile fracture tests were performed at mucosa-submucosa, serosa-muscle and intact layer, respectively. Results showed that the biomechanical properties of the porcine stomach depended on the layers, orientations and locations of the gastric wall and presented typical viscoelastic, nonlinear and anisotropic mechanical properties. During loading-unloading test, the stress of serosa-muscle layer in the longitudinal direction was 15-20% more than that in the circumferential direction at 12% stretch ratio, while it could reach about 40% for the intact layer and 50% for the mucosa-submucosa layer. The results of stress relaxation and strain creep showed that the variation degree was obviously faster in the circumferential direction than that in the longitudinal direction, and the ultimate residual values were also different for the different layers, orientations and locations. In the process of fracture test, the serosa-muscle layer fractured firstly followed by the mucosa-submucosa layer when the intact layer was tested, the longitudinal strips firstly began to fracture and the required stress value was about twice as much as that in the circumferential strips. The anisotropy and heterogeneity of mechanical characterization of the porcine stomach were related to its complicated geometry, structure and functions. The results would help us to understand the biomechanics of soft organ tissue.

[Intraoperative radiotherapy of unresectable pancreatic carcinoma].

During the period from 1986 to 1991, 33 patients with unresectable carcinoma of the pancreas received intraoperative radiotherapy (IORT). Abdominal and back pain which tormented all patients before IORT totally disappeared in 18 patients (54%) and was allevrited in 13 patients (40%). The average survival time of 6.5 months for patients treated with IORT was not statistically different from that of 30 patients with resectable pancreatic cancers undergoing resection. IORT hence is a good palliative therapy for unresectable carcinoma of the pancreas.

[Analysis of serum levels of selenium, zinc, and copper in 132 patients with malignant tumors].

Since March 1987 to December 1988, serum levels of selenium, zinc, and copper were determined in 132 patients with malignant tumors and in a control group of 43 patients with benign disease. The mean level of selenium in 132 patients with malignant tumors was 0.074 microgram/ml, it was lower than in the control group (P less than 0.01). Zinc was 0.814 microgram/ml, it was low compared to the control group (P less than 0.05). Copper was 1.27 microgram/ml, it was significantly increased (P less than 0.05). Cu/Zn was higher than in the control group (P less than 0.01). An analysis of all the readings showed that the lowest levels of selenium and zinc are associated with advanced gastrointestinal cancer.

[Cystadenoma of the pancreas].

Cystadenoma of the pancreas is a rare tumor, which usually occurs in young women. In this paper, 8 patients are reported. The common clinical symptom was upper abdominal mass or discomfort. The tumor was located by ultrasonography and CT scan. Impression and displacement of the duodenum and stomach were showed by barium meal examination of the upper gastrointestinal tract. Macroscopically, the tumor was encapsulated. Its section showed cystic and multilocular structures. Microscopically, the tumor cells were in papillary arrangement. Six of these 8 patients were misdiagnosed as pseudocyst of the pancreas and cystojejunostomy was performed. Three of 6 underwent malignant change, which was finally diagnosed by fine needle aspiration cytology. This tumor, even after malignant change, is prone to local invasion and less likely towards distant metastasis. Resection, including pancreatoduodenectomy, is the best treatment.

[CT-guided percutaneous fine needle aspiration cytodiagnosis of pancreatic and periampullary tumors].

CT guided percutaneous fine needle aspiration cytodiagnosis was performed on 30 patients with pancreatic and periampullary tumors in China-Japan Friendship Hospital from November 1984 to January 1986. In our series, 9 pancreatic head cancers, 4 pancreatic body and tail cancers, 5 ampullary cancers had positive cytodiagnosis (100%-18/18). 2 of 3 (67%) duodenal cancers and 6 of 7 (86%) the distal common bile duct cancers were positive by cytodiagnosis. 2 pancreatitis were negative (100%). The positive rate by CT guided diagnosis was 93.3% (28/30). In the same period, ultrasonically guided percutaneous fine needle aspiration cytodiagnosis was performed on 30 patients with pancreatic and periampullary tumors, a correction rate of diagnosis was 67%. CT guided procedure is more accurate than that ultrasonically guided.