Objective To investigate the value of multi-parameter features based on MRI in the differential diagnosis of benign parotid tumors.Methods Retrospective analysis was conducted on the MRI data of 144 lesions in 123 patients.According to the pathological results,all cases were divided into pleomorphic adenoma(PA)group(n=90)and non-PA group(n=33).The gender,location,MRI signal and dynamic enhancement types of the two groups were compared and analyzed.Results There were all significant differences in age,gender,cystic degeneration,T1WI,T2WI signals,types of time-signal intensity curve(TIC),lesion location,edge and apparent diffusion coefficient(ADC)values between PA and non-PA groups(P＜0.05).Gender(female),T2 high signal and ADC values were in good agreement with the pathological results in PA(Kappa value was 0.62,0.62,0.78,respectively,P＜0.05).The receiver operating characteristic(ROC)curve showed that ADC value and Tpeak had good differential diagnostic value.Area under the curve(AUC)(AUCADC and AUCTpeak)were 0.97[95％confidence interval(CI)0.92-1.00]and 0.76(95％CI 0.52-0.97),respectively.Cut-off value of ADC was 1.03×10-3 mm2/s,and sensitivity and specificity was 85.71％and 100.00％,respectively.Cut-off value of Tpeak was 102 s,and sensitivity and specificity was 71.43％and 75.00％,respectively.When the two parameters were combined for differential diagnosis,the AUC was 0.92(95％CI 0.92-1.00),and the sensitivity and specificity was 92.86％and 87.50％,respectively.Conclusion The comprehensive analysis of multi-parameter imaging features based on MRI can improve the accuracy of differential diagnosis of benign parotid tumors and help to formulate individualized treatment plans.

Objective:To explore the application value of flexible endoscopy and rigid endoscopy in the clinical examination of chronic sinus tract wounds with different shapes.Methods:A retrospective observational study was conducted. From January 1 to December 23, 2019, a total of 46 patients with chronic sinus tract wounds, who met the inclusion criteria were admitted to the Wound Healing Center of Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, including 23 males and 23 females, aged 18-81 (48±21) years. On admission, computer tomography (CT) imaging and three-dimensional reconstruction were performed to examine the shapes of wound sinus tract and classify the wounds, with the lengths of wound sinus tract by CT imaging examination (hereinafter referred to as reference lengths) recorded. The lengths of wound sinus tract were examined and measured by rigid endoscopy and flexible endoscopy. The wounds with and without obviously curved sinus tract were classified into curve group and linear group respectively, and the deviation rates between the lengths of wound sinus tract measured by flexible endoscopy or rigid endoscopy and the reference lengths (hereinafter referred to as deviation rates of lengths) in each group were calculated. The difference between the deviation rates of lengths examined by flexible endoscopy and rigid endoscopy and the differences between the above two and the deviation rate of reference lengths (0) in each group were compared. Data were statistically analyzed with paired sample t test and Wilcoxon signed rank sum test. Results:CT imaging and three-dimensional reconstruction showed that there were 4 types of wound sinus tract, including tubular (36/46), lamellar (4/46), club-mallet (4/46), and irregular (2/46) shape. Tubular wounds were further divided into type I (23/36), type L (4/36), and type Y (9/36). Wounds with type I tubular, lamellar, and club-mallet sinus tract were classified into linear group (31/46), while those with type Y tubular, type L tubular, and irregular sinus tract were classified into curve group (15/46). In linear group, the deviation rates of lengths examined and measured by rigid endoscopy and flexible endoscopy were 0. In curve group, the deviation rate of lengths examined and measured by flexible endoscopy was 0 (0, 0.58%), which was significantly lower than 41.18% (31.68%, 48.41%) examined and measured by rigid endoscopy, Z=-3.408, P<0.01; the deviation rate of lengths examined and measured by rigid endoscopy (40±19)% was significantly higher than the deviation rate of reference lengths ( t=8.343, P<0.01), while the deviation rate of the lengths examined and measured by flexible endoscopy was similar to the deviation rate of reference lengths ( Z=-1.342, P>0.05). Conclusions:Compared with rigid endoscopy, flexible endoscopy can observe the internal characteristics of chronic sinus tract wounds in a wider range in the clinical examination of this kind of wound, especially for the exploration of curved chronic sinus tract wounds. The promotion of this method will be conducive to the diagnosis and treatment of chronic sinus tract wounds.

Objective: To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts. Methods: A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test. Results: (1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01). Conclusions Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

Objective: To explore the application value of endoscope in probing the chronic wound with sinus tract in clinic. Methods: Twenty-eight chronic wounds with sinus tracts from 27 patients conforming to the inclusion criteria admitted to Outpatient Department of Wound Healing Center of Ruijin Hospital from December 2017 to March 2018 were investigated in a prospective and self-controlled trial. After being cleaned, the diameter of the opening of sinus tract was measured with a rule. A probe was used to measure the depth of a sinus tract according to the touch from the probe extremity in operation, and to measure the depth of a sinus tract that could be observed with naked eyes with the help of a pair of hemostatic forceps. Five minutes later, a probe was inserted deeply into the sinus tract to measure the depth under the endoscopic view combined with touch from the probe extremity in operation. Afterwards, the sinus tract was observed with endoscope, and the depth of the tract which could be observed under the endoscopic view was measured using a probe inserted deeply into the sinus tract. After completion of the above exploration, the sinus tract was infused with contrast agent Omnipaque 350 and scanned by computed tomography (CT) later to obtain its depth. The following indicators were calculated: the ratio of the depth of the sinus tract measured by CT to the diameter of the opening of the sinus tract (hereinafter referred to as the depth/diameter ratio of the sinus tract), the deviation rate comparing the depth of the sinus tract measured by conventional method (measured by probe only) and by endoscope (measured by probe under the endoscope view) with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the measured depth of the sinus tract), the deviation rate comparing the depth of the sinus tract that could be observed measured by conventional method and by endoscope with the depth of the sinus tract measured by CT (hereinafter referred to as the deviation rate of the depth of the sinus tract that could be observed). Data were processed with paired t test. Pearson correlation analysis was applied to analyze the correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope. Results: The depth/diameter ratio of the sinus tract of this group of wounds was 1-32 (8±7). The deviation rate of the measured depth of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method were (19±14)% and (79±18)%, respectively, both obviously larger than (9±9)% and (25±25)% by endoscope (t=3.837, 13.626, P<0.01). Positive correlation existed between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by conventional method, and between the depth/diameter ratio of the sinus tract and the deviation rate of the depth of the sinus tract that could be observed by conventional method and by endoscope (r=0.514, 0.585, 0.651, P<0.01). However, there was no obvious correlation between the depth/diameter ratio of the sinus tract and the deviation rate of the measured depth of the sinus tract by endoscope (r=0.113, P>0.05). Conclusions Compared with the conventional method, application of endoscope is able to get more accurate data of chronic wounds with sinus tracts and observe the wounds with wider range.

The correct thoughts and principles of diagnosis and treatment of chronic refractory wounds need to be formulated. Through the relevant domestic and international consensus and based on clinical experience, the Thoughts and principles of diagnosis and treatment of chronic refractory wounds in China is proposed. It is considered that in the diagnosis and treatment of chronic refractory wounds, in the case of fully understanding the patient′s medical history, the following thoughts and principles should be complied in order. (1) Pay attention to the cleanliness of the wound after being cleaned. (2) Reasonably perform debridement to avoid being " excessive" or " not thorough". (3) Reasonably perform examination, diagnosis, and differential diagnosis of pathogenic factors. (4) Treat according to etiology. (5) Find comorbidities and prevent adverse outcomes. (6) Select the correct wound treatment method reasonably and timely. When the conservative wound care treatment is considered, pay attention to embodying the concept of etiological treatment, treat the wound according to the principles of safety, phase, selectivity, and effectiveness, and make a reasonable choice of continuing conservative treatment or surgical treatment in time after completing the preparation of the wound bed. When surgical treatment is considered, pay attention to the selection of reasonable surgical method and donor site, pay attention to the healing rate of surgical wound site and the outcome of donor site, and give reasonable protection to the wound site after surgery. (7) Carry out rehabilitation treatment after wound healing and related health education.

Objective To examine the occupational stability,training needs and capacity building requirements of the general practitioners purposely trained to work in rural communities,for improvement of policies regarding their training and issues related. Methods There counties were selected by stratified random sampling, where general practitioners graduated from such training completed an anonymous questionnaire. Focus group interviews were made to officials of the local Health and Family Planning Commission,those of primary healthcare institutions,and general practitioners themselves. Results The of the 190 valid questionnaires recovered, male accounted for 34. 2% and female 65. 8%. These general practitioners were mostly satisfied with their working environment, social status, work stress and job achievement,yet with lower satisfaction with their salary and availability of medical devices. Consideration of resignation was reported by only 5. 3% of them,with more males than females. As high as 63. 2% of them prefer to work in hospitals of county level. 91. 1% of them held it as necessary to participate in standard resident training,and 98. 4% held it as necessary to have on-job training. 94. 7% of them have participated in further education to gain a bachelor degree in medicine. Conclusions These doctors were found with high stability to work in rural communities and low turnover intention. Further studies are required to encourage these general practitioners to serve rural communities in a long term, and to improve the standard resident training mechanism,and their career development.

Objective To simulate the environmental factors during the process of formation and evolution of hypertrophic scar,so as to explore the effects of moderate and severe hypoxia and low concentration of serum protein on the function of human hypertrophic scar fibroblasts (HSFs).Methods Human HSFs were routinely cultured.Cells of the 3rd to the 6th passage were divided into 10.0％ oxygen + 10.0％fetal calf serum (FCS),5.0％ oxygen + 5.0％ FCS,and 0.5％ oxygen + 0.5％ FCS groups according to the random number table.After being cultured with DMEM nutrient solution with no FCS for 24 h,the cells were cultured with the corresponding volume fraction of oxygen and FCS.Cell proliferation activity was determined with methyl-thiazole-tetrazolium assay (denoted as actual cell number).Content of total collagen was detected with Sirius red staining method (denoted as absorbance value).Protein expression levels of hypoxia-inducible factor 1 α (HIF-1 α),vascular endothelial growth factor (VEGF),transforming growth factor β1 (TGF-β1),B-cell lymphoma 2 (Bcl-2),and P53 were determined with Western blotting (denoted as ratio of gray value).Cell apoptosis rate was detected by in situ end labeling method.The sample numbers of each group in the above experiments were all 3.Data were processed with Kruskal-Wallis test and Dunnett test.Results (1) Compared with 11 000 ± 1 306 in 10.0％ oxygen + 10.0％ FCS group,the cell proliferation activity was higher in 5.0％ oxygen + 5.0％ FCS group (13 290 ± 1 500,P ＜ 0.05),but lower in 0.5％oxygen +0.5％ FCS group (6 999 ±765,P ＜0.05).(2) Compared with 0.039 6±0.004 2 in 10.0％oxygen + 10.0％ FCS group,the content of total collagen of cells was higher in 5.0％ oxygen + 5.0％ FCS group (0.051 6±0.005 1,P ＜0.05),but lower in 0.5％ oxygen +0.5％ FCS group (0.015 6 ±0.002 4,P ＜ 0.05).(3) Compared with those in 10.0％ oxygen + 10.0％ FCS group,the protein expression levels of HIF-1 α,VEGF,TGF-β1,and Bcl-2 were increased (with P values below 0.05),with no obvious difference in protein expression level of P53 in 5.0％ oxygen + 5.0％ FCS group (P ＞ 0.05),whereas the protein expression levels of HIF-1α,VEGF,TGF-β1,and Bcl-2 were decreased (with P values below 0.05),while the protein expression level of P53 was increased in 0.5％ oxygen + 0.5％ FCS group (P ＜0.05).(4) Compared with (1.2 ±0.9)％ in 10.0％ oxygen+ 10.0％ FCS group,the cell apoptosis rate in 5.0％ oxygen + 5.0％ FCS group showed no significant difference [(2.6 ± 0.9)％,P ＞ 0.05],while it was significantly increased in 0.5％ oxygen + 0.5％ FCS group [(13.3 ± 4.1)％,P ＜ 0.05].Conclusions Severe hypoxia and low concentration of serum protein can inhibit proliferation activity and production of total collagen of human HSFs and induce their apoptosis.