Objective To study the properties and antimicrobial activity of the novel self-assembled antimicrobial peptide(AMP)CR-16,and to provide experimental evidence for the treatment of bacterial infections.Methods CR-16 was designed and synthesized based on the structure of antimicrobial peptides Buforin Ⅱ and LfcinB.Dynamic light scattering(DLS),transmission electron microscopy(TEM),and X-ray diffraction(XRD)were used to characterize CR-16.Based on the results of critical micelle concentration(CMC),the self-assembled properties of CR-16 were investigated using atomic force microscopy(AFM)and circular dichroism(CD).The minimum inhibitory concentration(MIC)was used to study the inhibitory effect of CR-16 while transmission electron microscopy(TEM)was adopted to observe the interactions between CR-16 and the outer membrane of bacteria.Results AMP CR-16 was prepared as self-assemblies,which were regularly spherical in shape and stable in activity.CR-16 could inhibit both the growth of Escherichia coli and,more importantly,the growth of NDM-1-producing carbapenem-resistant Escherichia coli,promising good prospects in treating infections caused by antibiotic-resistant bacteria.Conclusion CR-16 can be self-assembled and deliver antibacterial effects against Escherichia coli.

Objective To enhance the photostability of colchicine(COL)for sustained-release COL pellets.Methods The degradation was investigated by studying the photochemical degradation kinetics of COL.The impact of such physical properties of the photostabilizers as the type,color,dosage,and position on the photostability of COL in sustained-release pellets was also evaluated.Results The contents of photochemical degradation products did not increase after 10 days of light exposure to sustained-release COL pellets with red iron oxide of 4％(w/w)as the protective layer.Conclusion The findings of this study indicate that use of iron oxide as a photostabilizer in sustained-release COL pellets can significantly reduce the photochemical degradation of COL in the pellets.

Colorectal serrated lesions are a group of polyps/adenomas with serrated architecture, including hyperplastic polyp, sessile serrated lesion and sessile serrated lesion with dysplasia, traditional serrated adenoma, and unclassified serrated adenoma. Sessile serrated lesion and traditional serrated adenoma are precursors of serrated lesions progressing to colorectal cancer. Serrated lesions are characterized by genetic (BRAF or KRAS gene mutations) and epigenetic (CpG island methylator phenotype) alterations that synergistically drive colorectal mucosa to develop polyps or adenomas, and with malignant transformation into colorectal cancer. The complexity of serrated lesion makes it difficult to diagnose, easy to miss diagnosis and has a high malignant rate. This article reviewed the advances in research on colorectal serrated lesions from the aspects of endoscopic, pathological and molecular features.

Objective:To investigate the expression of programmed death ligand 1 (PD-L1) in rectal cancer tissues and the correlation of PD-L1 expression with clinicopathological characteristics and overall survival of patients.Methods:The clinical data of 200 newly treated rectal cancer patients in Shanxi Provincial Cancer Hospital from January 2014 to December 2015 were retrospectively analyzed. The expression of PD-L1 in rectal cancer tissues was detected by immunohistochemistry. The correlations of PD-L1 expression with gender, age, tumor T stage, lymph node metastasis, tumor differentiation, histological type, tumor TNM stage, neutrophil-to-lymphocyte ratio (NLR) and overall survival of patients were analyzed.Results:The positive expression rate of PD-L1 was 24% (48/200). The positive expression rate of PD-L1 was high in patients with lymph node metastasis and high NLR (≥ 3.5) (both P < 0.05). The 5-year overall survival rate in PD-L1-positive group was 42%, and the PD-L1-negative group was 59%, and the difference between the two groups was statistically significant ( P < 0.05). The results of multivariate analysis showed that lymph node metastasis ( HR = 3.456, 95% CI 2.148-5.556, P < 0.01), NLR ≥ 3.5 ( HR = 1.871, 95% CI 1.169-2.996, P = 0.009), and PD-L1-positive expression ( HR = 2.187, 95% CI 1.373-3.484, P = 0.001) were independent adverse influencing factors for the overall survival of rectal cancer patients. Conclusion:PD-L1 is highly expressed in rectal cancer tissues, and the positive expression of PD-L1 is associated with poor overall survival of patients.

Objective:To analyze clinicopathological characteristics of trauma-related melanoma and their relationship with the prognosis of patients.Methods:Clinical data were collected from 87 cases of trauma-related melanomas in Department of Dermatology, Xijing Hospital, the Fourth Military Medical University from 2009 to 2020, and their clinicopathological characteristics were retrospectively analyzed. Mann-Whitney test was used to analyze the difference in Breslow thickness of tumors between patients of different ages or genders; Spearman rank correlation analysis was used to analyze the correlation between the time from trauma to the notice of melanoma and Breslow thickness, Kaplan-Meier survival analysis and Log-Rank test were employed to analyze the relationship between clinicopathological characteristics of melanoma and the prognosis of patients; Cox regression model was used to analyze risk factors for survival duration of patients with trauma-related melanoma.Results:Among the 87 patients with trauma-related melanoma, 47 (54.02%) were males and 40 (45.98%) were females. Among them, melanoma occurred in 50 (57.47%) cases after sharp injuries, and in 37 (42.53%) after blunt injuries. In addition, 31 (35.63%) cases presented with primary lesions on the hands, and 48 (55.17%) on the feet. The Breslow thickness of the primary tumors was significantly higher in the group aged > 55 years than in the group aged ≤ 55 years ( U= 623.500, P= 0.010) , but there was no significant difference between patients of different genders ( P= 0.138) . The time from trauma to the notice of melanoma was negatively correlated with the Breslow thickness of tumors ( r=-0.203, P= 0.037) . The age of patients, Breslow thickness of tumors, Ki67 proliferation index and genetic background of tumor significantly affect the survival duration of patients with trauma-related melanoma ( P= 0.011, 0.031, 0.002 and 0.031, respectively) ; the gender, type of trauma and ulceration of tumor mass did not significantly affect the survival duration of patients ( P= 0.618, 0.114 and 0.379, respectively) . Cox regression model analysis showed that the Ki67 proliferation index and Breslow thickness were independent risk factors affecting the prognosis of trauma-related melanoma (risk ratio [ RR] and 95% confidence interval [ CI] were 1.946 (1.234, 4.217) and 1.839 (1.014, 3.332) , P= 0.039 and 0.045, respectively) . Conclusion:The Breslow thickness of trauma-related melanoma is related to the age of patients and time from trauma to the notice of melanoma; the age, Breslow thickness of tumors, Ki67 proliferation index and genetic background of tumor all affect the survival duration of patients with melanoma, and Ki67 proliferation index and Breslow thickness are independent risk factors affecting prognosis.

Objective:To assess clinical efficacy of micro-punch combined with electron beam radiation for the treatment of keloids on the lower jaw.Methods:Clinical data were collected from 36 patients with keloids on the lower jaw, who received micro-punch combined with electron beam radiation at Department of Dermatology, Xijing Hospital, the Fourth Military Medical University from January 2018 to January 2019, and analyzed retrospectively. There were 16 males and 20 females, with an average age of 23.80 years and a median disease duration of 32 months. The severity of keloids was evaluated before and 12 months after operation. A paired t test was used to compare keloid severity scores before and after treatment. Results:All of the 36 patients experienced primary wound healing. The keloid severity score was 7.11 ± 1.46 before operation, and significantly decreased to 2.33 ± 0.47 at 12 months after operation ( t=13.85, P=0.008) . Twelve months after the treatment, 15 patients were cured, 17 showed marked improvement, and 4 showed no response or experienced recurrence within 12 months after treatment, with a response rate of 88.89%. Conclusion:Micro-punch combined with electron beam radiation is effective for the treatment of keloids on the lower jaw.

Objective To investigate the clinical efficacy and safety of six-hole moxibustion box therapy for stable chronic obstructive pulmonary diseases(COPD).Methods Sixty patients with thoracic facet joint disorder were randomly allocated to treatment and control groups, 30 cases each. The control group inhaled tiotropium bromide inhalation powder spray and the treatment group received six-hole moxibustion box therapy in addition. The COPD Assessment Test (CAT) score and the dyspnea score were recorded and peripheral blood oxygen saturation was measured in the two groups before and after treatment. The adverse reactions were monitored in the two groups. Results There were statistically significant pre-/post-treatment differences in the CAT score and the dyspnea score in the two groups (P<0.05). There were statistically significant post-treatment differences in the CAT score and the dyspnea score between the treatment and control groups (P<0.05). There were statistically significant differences in pre-/post- treatment CAT score difference value and dyspnea score difference value between the two groups (P<0.05). There was a statistically significant pre-/post-treatment difference in peripheral blood oxygen saturation in the treatment group (P<0.05). There was a statistically significant post-treatment difference in peripheral blood oxygen saturation between the two groups (P<0.05).Conclusion Six-hole moxibustion box therapy plus tiotropium bromide inhalation powder spray is safe and effective in treating stable COPD.

Objective To establish assay methods for the determination of dissolution,content and related substances of vita-min K1 self-nanoemulsifying drug delivery system(VK1-SNEDDS),and investigate the physico-chemical properties of the preparation. Methods The UV method was established to determine the dissolution of VK1-SNEDDS. The content and related substances were de-termined by HPLC. The appearance,self-emulsification time,micro-morphology,droplet size and zeta potential were also investigat-ed. Results The linearity range of established UV and HPLC methods was 0.85-20.4 and 2.16-216μg/ml,respectively,and all the recovery,precision,specificity and sensitivity met requirements. VK1-SNEDDS could disperse quickly after dilution. The transmission electron microscope(TEM)image of the optimized liquid SNEDDS showed that most of the emulsion droplets were of uniform size with no signs of coalescence. Droplet size of optimal formulation was revealed as 47.74 nm with polydispersibility index(PDI)of 0.248,and zeta potential was found to be-20.53 mV. Conclusion VK1-SNEDDS could form homogeneous and stable nanoemulsion when dilut-ed with aqueous phase and increase the dissolution of lipophilic drug. The methods are reliable,accurate and suitable for quality con-trol of VK1-SNEDDS.

Objective To establish an HPLC method for determination of related substances of dexmethylphenidate hydrochloride and their content .Methods The HPLC method was used on an Agilent ZORBAX SB-C18 column with a mo-bile phase of methanol-0.2%triethyl citrate in 25 mmol/L potassium dihydrogen phosphate ( pH was adjusted to 3.5 with phosphoric acid) (35∶65) at a flow rate of 1.0 ml/min.The detection wavelength was 209 nm and column temperature was 40℃.Results Under the selected chromatographic condition , dexmethylphenidate hydrochloride was completely separated from impurity.The limit of detection was 81.12 ng/ml.The calibration curve was linear in the range of 2-30 μg/ml ( r=0.9995).The average recovery of the method was 100.83%, and the stability of the working solution was acceptable in 12 h(RSD=0.10%).Conclusion This method is simple,specific,accurate and suitable for analyzing the related substances and their content in dexmethylphenidate hydrochloride .

Objective To evaluate the effect of isoflurane preconditioning on inflammatory responses during spinal cord injury (SCI ) in rats .Methods Sixty adult male Sprague-Dawley rats ,weighing 250-300 g , were randomly divided into 3 groups ( n= 20 each ) using a random number table :sham operation group (S group) , SCI group , and isoflurane preconditioning group (I group ) . The animals were anesthetized with intraperitoneal pentobarbital sodium 40 mg/kg .SCI was produced by a weight-drop contusion at the T10 level .The rats inhaled 2% isoflurane for 2 h ,and the model was established at 24 h after the end of isoflurane inhalation in I group . Neurological function was assessed and scored by using the the Basso , Beattie , Bresnahan (BBB ) Locomotor Rating Scale on 7 days after SCI .Five rats in each group were then chosen and spinal cord specimens were obtained and cut into sections which were stained with haematoxylin and eosin for determination of the viable neuron count .Fifteen rats in each group were sacrificed and the spinal cord was removed for detection of nuclear factor kappaB (NF-κB ) and interleukin-1β (IL-1β) expression (by Western blot ) .Results Compared with S group ,BBB score and the number of viable neurons were significantly decreased ,and the expression of NF-κB and IL-1βprotein was up-regulated in SCI group ( P<0.05) .Compared with SCI group ,BBB score and the number of viable neurons were significantly increased ,and the expression of NF-κB and IL-1βprotein was down-regulated in group I ( P<0.05 ) .Conclusion The mechanism by which isoflurane preconditioning protects the spinal cord is related to inhibition of inflammatory responses in rats .