Objective To study the biocompatibility of carboxymethyl chitosan (CMCS) membrane with melanocytes from healthy human skin,and to investigate the feasibility to transport and carry melanocytes by using CMCS membrane.Methods CMCS membrane was prepared by a casting method combined with a glutaraldehydebased cross-linking method.Melanocytes were isolated from the foreskin of healthy men,and subjected to primary culture and subculture.The third-passage melanocytes were classified into two groups to be cultured on the CMCS membrane (test group) or traditional culture plates (control group).Methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate the proliferative activity of melanocytes,and a sodium hydroxide-based lysis method to determine melanin content.HMB45 staining was conducted,and tyrosinase activity was estimated for melanocytes.Results Inverted microscopy showed that melanocytes were evenly distributed on the CMCS membrane with a normal shape.The melanocytes adherent to the CMCS membrane stained positive for anti-HMB45 monoclonal antibody.The growth curve of the melanocytes on the CMCS membrane,which was obtained from MTT assay,demonstrated that CMCS membrane could support the normal growth of melanocytes.No significant difference was observed between the test group and control group in melanin content (0.083 ± 0.015 vs.0.066 ± 0.008,t =2.38,P ＞ 0.01) or tyrosinase activity (0.234 ± 0.083 vs.0.241 ± 0.061,t =0.23,P ＞ 0.05).Conclusion CMCS membrane can maintain the normal biological activity of melanocytes and have good biocompatibility with skin melanocytes.

Objective:Berberine hydrochloride(BBR)is commonly used for the treatment of ulcerative colitis(UC),but its molecular mechanism,especially the mechanism of rescue of inflammatory-induced pyroptosis,needs to be further analyzed.Meth-ods:SD male rats were randomly divided into four groups:control group(Ctrl),DSS model group,BBR treatment group(DSS+BBR)and BBR+NLRP3 agonist group(DSS+BBR+BMS-986299).The UC rat model was established by the dextran sulfate sodium method(DSS).At the same time,BBR was intragastrically administered to BBR treatment group and BBR+NLRP3 agonist group twice per-day for 7 consecutive days.BMS-986299 was intraperitoneally injected to BBR+NLRP3 group twice a day.During the experiment,the body weights were weighed,the general condition was observed,and the disease activity index(DAI)was evaluated every day.After the experiment,the gross morphology and length of colon were observed and evaluated.HE staining was used to observe the pathologi-cal changes of colon tissue and evaluate the tissue injury index(TDI).ELISA was employed for detecting the contents of TNF-α and IL-1β in colon tissue,and Western blot was employed for detecting NLRP3,ASC,GSDMD-N,Cleaved-caspase 1 and IL-1β expres-sions.Results:BBR could effectively improve the UC-induced weight loss,colon tissue integrity and cell pyroptosis,reduce the expression levels of inflammatory factors such as TNF-ɑ and IL-1β,the proportion of pyroptosis,and the levels of proteins NLRP3,IL-1β,GSDMD-N,and Cleaved-caspase 1 which play crucial roles in pyroptosis pathway.The therapeutic effect and the regulated pro-tein expression through BBR were reversed by NLRP3 activation.Conclusion:BBR exerts a therapeutic effect by reducing the proteins levels of mature NLRP3,IL-1β,GSDMD-N,Cleaved-caspase 1,which are responsible for pyroptosis pathway.This result provides a molecular basis for BBR in treatment of UC.

Objective:To investigate the role of Na+/Ca2+ exchanger (NCX) in myocardial ischemiareperfusion injury and the underlying mechanisms.Methods:Forty Sprague-Dawley rats were divided into 4 groups randomly:a control group,a KBR7943 group,an ischemia-reperfusion group (IR group),and an IR plus KB-R7943 group (KB-R7943+IR group).Isolated Sprague Dawley male rat hearts underwent Langendorffperfusion.The ratio of left ventricular developed pressure (LVDP),left ventricular end-diastolic pressure (LVEDP),the infarct size of myocardium,and the lactate dehydrogenase (LDH) activity in the coronary flow was determined.HE staining was used to assess the change of myocardial morphology.Western blot was used to determine the levels of cleaved caspase-3,cytochrome c and the phosphorylation of Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) and the Thr17 site ofphospholamban.Results:Compared with the control group,IR group significantly induced an enlarged infarct size,reduction of the ratio of LVDP,up-regulation of cytochrome c,cleaved caspase-3,p-CaMKⅡ and p-phospholamban,and increased in the activity of LDH,the level of LVEDP (P＜0.01) and the disordered myocardial morphology.These effects were significantly attenuated in the presence of KB-R7943 treatment (10 μmol/L).Conclusion:NCX mediates myocardial ischemia-reperfusion-induced cell apoptosis and necrosis through activation of CaMKⅡ.

Objective To evaluate the long?term efficacy of transjugular intrahepatic portosystemic shunt(TIPS)for gastric variceal bleeding. Methods A retrospective analysis was performed on the data of 65 cirrhotic patients with type 1 isolated gastric variceal bleeding in the First Affiliated Hospital of Anhui Medical University from January 2014 to January 2016.Patients were divided into two groups,TIPS treatment group(n=28),and gastric variceal obturation(GVO)treatment group(n=37). The long?term follow?up results of the two groups were compared. Results Operations of the two groups were succeed. Postoperative complications in the TIPS group and GVO group were 7.14%(2/28)and 13.51%(5/37), respectively, (P=0.801).Nine cases(32.14%)had mild hepatic encephalopathy in the TIPS group,and no occurred in the GVO group. During the 20.18 ± 6.90 months of follow?up in the TIPS treatment group, 2(7.14%) patients died, and the cumulative rebleeding?free rate at 6, 12 and 18 months was 88.4%, 83.7% and 76.1%,respectively.During the 16.14±6.03 months of follow?up in the GVO treatment group,5(13.51%) patients died, and the cumulative rebleeding?free rate at 6, 12 and 18 months was 86.5%, 70.2% and 60.9%,respectively. The survival rate between the two groups had no significant difference(P=0.690). There was a statistically significant difference in the cumulative non?bleeding rate in 18 months of follow up(log?rank test,χ2=6.304,P=0.012). Conclusion TIPS is superior to GVO for controlling gastric variceal bleeding in the long run,but clinicians should be vigilant to the occurrence of hepatic encephalopathy after operation.

OBJECTIVE: To investigate the protective effect of melatonin against myocardial ischemia reperfusion (IR) injury in isolated rat hearts and explore the underlying mechanisms. METHODS: The isolated hearts from 40 male SD rats were randomly divided into 4 groups (=10): the control group, where the hearts were perfused with KH solution for 175 min; IR group, where the hearts were subjected to global ischemia for 45 min followed by reperfusion for 120 min; IR+melatonin (Mel+IR) group, where melatonin (5 μmol/L) was administered to the hearts 1 min before ischemia and during the first 5 min of reperfusion, followed by 115 min of reperfusion; and IR+2, 3-butanedione monoxime (IR+BDM) group, where the hearts were treated with BDM (20 mmol/L) in the same manner as melatonin treatment. Myocardial injury in the isolated hearts was assessed based on myocardial injury area, caspase-3 activity, and expressions of cytochrome C and cleaved caspase-3 proteins. Cardiac contracture was assessed using HE staining and by detecting lactate dehydrogenase (LDH) activity and the content of cardiac troponin I (cTnI) in the coronary outflow, measurement of left ventricular end-diastolic pressure (LVEDP) and electron microscopy. The content of ATP in the cardiac tissue was also determined. RESULTS: Compared with those in the control group, the isolated hearts in IR group showed significantly larger myocardial injury area and higher caspase-3 activity and the protein expressions of cytochrome C and cleaved caspase-3 with significantly increased LDH activity and cTnI content in the coronary outflow and elevated LVEDP at the end of reperfusion; HE staining showed obvious fractures of the myocardial fibers and the content of ATP was significantly decreased in the cardiac tissue; electron microscopy revealed the development of contraction bands. In the isolated hearts with IR, treatment with Mel or BDM significantly reduced the myocardial injury area, caspase-3 activity, and protein expressions of cytochrome C and cleaved caspase-3, obviously inhibited LDH activity, lowered the content of cTnI and LVEDP, reduced myocardial fiber fracture, and increased ATP content in the cardiac tissue. Both Mel and BDM inhibited the formation of contraction bands in the isolated hearts with IR injury. CONCLUSIONS Mel can alleviate myocardial IR injury in isolated rat hearts by inhibiting cardiac contracture, the mechanism of which may involve the upregulation of ATP in the cardiac myocytes to lessen the tear of membrane and reduce cell content leakage.
Animals ; Heart ; drug effects ; Male ; Melatonin ; pharmacology ; therapeutic use ; Muscle Contraction ; drug effects ; Myocardial Reperfusion Injury ; drug therapy ; Myocytes, Cardiac ; drug effects ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the protective effect of melatonin against myocardial ischemia reperfusion (IR) injury in isolated rat hearts and explore the underlying mechanisms. METHODS: The isolated hearts from 40 male SD rats were randomly divided into 4 groups (=10): the control group, where the hearts were perfused with KH solution for 175 min; IR group, where the hearts were subjected to global ischemia for 45 min followed by reperfusion for 120 min; IR+melatonin (Mel+IR) group, where melatonin (5 μmol/L) was administered to the hearts 1 min before ischemia and during the first 5 min of reperfusion, followed by 115 min of reperfusion; and IR+2, 3-butanedione monoxime (IR+BDM) group, where the hearts were treated with BDM (20 mmol/L) in the same manner as melatonin treatment. Myocardial injury in the isolated hearts was assessed based on myocardial injury area, caspase-3 activity, and expressions of cytochrome C and cleaved caspase-3 proteins. Cardiac contracture was assessed using HE staining and by detecting lactate dehydrogenase (LDH) activity and the content of cardiac troponin I (cTnI) in the coronary outflow, measurement of left ventricular end-diastolic pressure (LVEDP) and electron microscopy. The content of ATP in the cardiac tissue was also determined. RESULTS: Compared with those in the control group, the isolated hearts in IR group showed significantly larger myocardial injury area and higher caspase-3 activity and the protein expressions of cytochrome C and cleaved caspase-3 with significantly increased LDH activity and cTnI content in the coronary outflow and elevated LVEDP at the end of reperfusion; HE staining showed obvious fractures of the myocardial fibers and the content of ATP was significantly decreased in the cardiac tissue; electron microscopy revealed the development of contraction bands. In the isolated hearts with IR, treatment with Mel or BDM significantly reduced the myocardial injury area, caspase-3 activity, and protein expressions of cytochrome C and cleaved caspase-3, obviously inhibited LDH activity, lowered the content of cTnI and LVEDP, reduced myocardial fiber fracture, and increased ATP content in the cardiac tissue. Both Mel and BDM inhibited the formation of contraction bands in the isolated hearts with IR injury. CONCLUSIONS Mel can alleviate myocardial IR injury in isolated rat hearts by inhibiting cardiac contracture, the mechanism of which may involve the upregulation of ATP in the cardiac myocytes to lessen the tear of membrane and reduce cell content leakage.
Animals ; Contracture ; Male ; Melatonin ; Myocardial Ischemia ; Myocardial Reperfusion Injury ; Myocardium ; Myocytes, Cardiac ; Rats ; Rats, Sprague-Dawley

In carbohydrate chemistry, the stereoselective synthesis of 1,2-cis-glycosides remains a formidable challenge. This complexity is comparable to the synthesis of 1,2-cis-β-D-mannosides, primarily due to the adverse anomeric and Δ-2 effects. Over the past decades, to attain β-stereoselectivity in D-rhamnosylation, researchers have devised numerous direct and indirect methodologies, including the hydrogen-bond-mediated aglycone delivery (HAD) method, the synthesis of β-D-mannoside paired with C6 deoxygenation, and the combined approach of 1,2-trans-glycosylation and C2 epimerization. This review elaborates on the advancements in β-D-rhamnosylation and its implications for the total synthesis of tiacumicin B and other physiologically relevant glycans.
Glycosides ; Mannosides ; Glycosylation ; Stereoisomerism