Objective To explore analysis method of repeated measurements in single-sample. Methods Mixed linear model was presented and an example of repeated measurements in single-sample was analyzed. Results The reasonable results were obtained for repeated measurements in single-sample by the methods of mixed linear model. Conclusion Mixed linear model can be used to analyze repeated measurement data in single-sample.

Pancreatic stellate cell (PSC) activation in islet fibrosis of insulin-resistant rats induced by high-fat diet was investigated. After 20 weeks, the glucose infusion rate and glucose-stimulated insulin secretion in high-fat group were significantly decreased while fasting plasma glucose, fasting serum insulin, free fatty acid and the basal glucagon secretion were significantly increased compared with those parameters of the control rats (P< 0.05 or P<0.01). Activated PSC and collagen fiber ( type Ⅰ and Ⅲ) were found in islets of rats fed with high-fat. The result suggests that PSC activation, proliferation and migration to islet may contribute to islet fibrosis in insulin-resistant rats.

Objective To investigate the changes of peripheral insulin resistance after lipid infusion and the effect of N-acetylcystein(NAC) intervention.Methods Thirty-seven normal male SD rats,eight weeks old,were randomly divided into three groups,FFA group,NS group and NAC group(using into NAC 300 mg/(kg?d) two weeks before infusion).Catheters were implanted into right atrium via the jugular vein and left carotid artery.A technique for a 48-h infusion in unrestrained rats was used for triglyceride and heparin or saline infusion.The infusion period started on day 2 after surgery.48-h after infusion,we determined free fat acid(FFA),nitrotyrosine,malonaldehyde(MDA),reduced glutathione hormone(GSH) level in plasma.The glucose infusion rat(GIR) was measured by hyperinsulinemia euglycemic clamp to evaluated the perpherial insulin resistance.The expressions of IRS-1,IRS-2 gene in muscle were detected by real time PCR.Results(1)The FFA,nitrotyrosine and MDA con-centrations in FFA group were higher than that in NS group,but GSH level in plasma was lower.NAC intervention could reverse these effects.(2)GIR was decreased significantly in FFA group as compared with NS group[(8.34?1.8)mg/(min?kg)] vs[(13.56?1.7)mg/(min?kg)],(P

Objective To study the changes and mechanism of the function of islet βcells and insulin signal transduction molecules in rats after long-term period lipid infusion.Methods Thirty SpragueDawley (SD) rats were randomly divided into free fatty acid (FFA) and normal saline (NS) groups.Catheters were implanted under pentobarbital anesthesia in the right atrium via the jugular vein and the left carotid artery.A technique for a 72-h infusion in unrestrained rats was used for triglyceride and heparin or saline infusion.The infusion period was started on day 2 after surgery.After 72-h infusion,fasting serum insulin (Ins) and FFA in the blood were determined.The glucose infusion rat (GIR) was measured by hyperinsulinemia euglycemic clamp to evaluate the peripheral insulin resistance.The intravenous glucose tolerance test (ivgtt) and islet cell perifusion was conducted to evaluate the function of islet β-cell.The rats in two groups were sacrificed,and the pancreatic islets were isolated and collected.The levels of malondialdehyde (MDA) and reduced glutathione hormone (GSH) were detected in pancreatic tissues.The expressions of insulin receptor substrate-1 (IRS-1),insulin receptor substrate-2 (IRS-2),and glucose transporter-2 (Glut2)gene in islets were detected by real-time polymerase chain reaction (PCR).Results (1)The serum FFA concentration in the FFA group was higher than in NS group [(1.56 ± 0.21) mmol/L vs (0.65 ± 0.12)mmol/L,P ＜0.01].(2)The GIR was decreased significantly in FFA group compared with NS group(P ＜0.01).(3)The glucose that stimulated insulin secretion was decreased in the FFA group.(4)The levels of MDA were significantly higher in FFA group [(1.62 ± O.18) mmol/mg prot vs (0.76 ± 0.15) mmol/mg prot,P ＜0.01].The levels of GSH were lower in FFA group [(22.54 ±2.66) mg/g prot vs (36.58 ± 3.02) mg/g prot,P ＜ 0.01].(5) The gene cxprcssion of IRS-1 in islets was significantly decreased by [(36.8±1.8)％,P ＜0.01],and the expression of IRS-2 and Glut-2 was decreased by [(29.6±1.2) ％] and [(58.7 ± 2.1) ％] in FFA group,respectively(all P ＜0.01).Conclusions Lipid infusion in long time decreased the secretion of insulin and impaired the expression of insulin signal transduction molecules in islet βcells.

OBJECTIVETo investigate the effect of kirenol on bovine type II collagen (CII)-specific lymphocytes in vivo and in vitro, and explore the mechanism of kirenol-induced immunosuppression in antigen-specific lymphocytes.

METHODSTwenty-four Wistar rats were randomized into control group, collagen-induced arthritis (CIA) model group, kirenol group (2 mg/kg), and prednisolone group (2 mg/kg). After CII injection, the rats in the latter two groups received intragastric administration of kirenol and prednisolone for 30 days, and the spleens and draining lymph nodes of the rats were harvested to prepare single cell suspensions for measurement of the cytokine levels using ELISA. In the in vitro experiment, the lymphocytes from the control rats, with or without 20 µg/ml CII treatment in the presence of 0-80 µg/ml kirenol, were evaluated for cell proliferation and apoptosis using [(3)H]-thymidine incorporation and flow cytometry, respectively.

RESULTSCompared with those in CIA group, IFN-γ and TNF-α production was significantly reduced in splenocyte culture supernatant of kirenol group (P<0.05 and P<0.01, respectively), and the level of IL-10 and IL-4 was up-regulated (P<0.05 and P<0.01, respectively); IFN-γ and TNF-α secretion by the cultured lymph node cells (LNCs) significantly decreased (P<0.05 and P<0.001, respectively) and IL-10 and IL-4 production increased (P<0.05, P<0.001) in kirenol group. In the in vitro experiment, kirenol treatment caused obvious suppression of CII-induced LNC proliferation and dose-dependently induced antigen-specific apoptosis of the splenocytes and LNCs.

CONCLUSIONKirenol treatment reduces pro-inflammatory cytokine secretion, increases anti-inflammatory cytokine production, inhibits cell proliferation and induces apoptosis of CII-specific lymphocytes in vitro, suggesting the potential of kirenol as an immunosuppressant.

Animals ; Anti-Inflammatory Agents ; pharmacology ; therapeutic use ; Apoptosis ; drug effects ; Arthritis, Rheumatoid ; chemically induced ; drug therapy ; immunology ; Cattle ; Cell Proliferation ; Cells, Cultured ; Collagen Type II ; immunology ; Cytokines ; immunology ; Diterpenes ; pharmacology ; therapeutic use ; Female ; Immunosuppressive Agents ; pharmacology ; therapeutic use ; Lymphocytes ; cytology ; drug effects ; immunology ; Rats ; Rats, Wistar

Background The converter stations of high-voltage direct current (HVDC) transmission lines generate special total electric fields. At present, few investigations have been conducted on total electric fields in the workplace of converter stations from an perspective of occupational health. Objective To understand the current situation of total electric field strength in the workplace of converter stations. Methods Using purposive sampling, a calibrated HDEM-1 direct current (DC) total electric field strength measurement system was used to measure the total electric fields of 12 converter stations serving 6 DC lines in Southeast and Southwest China according to the Measurement method for total electric field strength and ion current density of the converter stations and DC transmission lines (DL/T 1089—2008). The results were evaluated according to occupational exposure limits recommended by The limits of electromagnetic environment at ±800 kV UHV DC converter station (DL/T 275—2012), the American Conference of Governmental Industrial Hygienists (ACGIH), and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Results A total of 615 check points were planned, the total electric field strength was 0.05-37.05 kV·m⁻¹, and the median was 10.45 kV·m⁻¹. The total electric field strength of 39 check points (6.3%) exceeded 25 kV·m⁻¹ (the limits of ACGIH and ICNIRP), and the total electric field strength of 12 check points (2.0%) exceeded 30 kV·m⁻¹ (the limit of DL/T 275—2012). There were statistically significant differences in the total electric field strength values and the proportions of exceeding 25 kV·m⁻¹ between the neutral regions and the positive regions and between the neutral regions and the negative regions (P < 0.01). The proportion of total electric field strength exceeding 30 kV·m⁻¹ in the negative regions was higher than that in the positive regions (P < 0.01). There were no significant differences in the total electric field strength of converter stations at different voltage levels and different altitudes (P > 0.05). There were no significant differences in the proportions of total electric field exceeding 25 kV·m⁻¹ and exceeding 30 kV·m⁻¹ in converter stations at different voltage levels and different altitudes (P > 0.05). Conclusion The total electric field in some workplace of converter stations exceeds selected limits. Converter station operators may be exposed to high-strength total electric field for a short time.