Leptin,a pleiotrophic hormone mainly synthesized by adipocytes,is an important signaling molecule in energy regulation and food intake.Recent studies have shown that Certain cancers are associated with leptin.This article reviews leptin's pathophysiological role in prostate cancer progression.

BACKGROUND:Measurement of cardiac troponin plays an important role in diagnosis of myocardial infarction.OBJECTIVE:To label the rabbit cardiac troponin C(cTnC) by a fluorescent probe 5-iodoaccetamidofluorescein(5-IAF),and to observe whether the 5-IAF can be used to study the interaction between cTnC and other contractile regulatory proteins.DESIGN,TIME AND SETTING:A randomized control experiment was performed at Department of Human Anatomy,Guangzhou Medical College,from January 2002 to December 2005.MATERIAL:Adult rabbits were provided by Experimental Animal Center of Guangzhou Medical College.METHODS:The rabbit cTnC DNA fragment was prepared with RT-PCR method.This gene fragment was cloned to pET expression vector by gene recombination technology.The site-directed mutagenesis were used to produce a mutant containing single cysteine at position 84 by replacing Cys35 with Ser,cTnC(C35S).The cTnC(C35S) was labeled by 5-IAF and 2-(4'-(iodoacetamido) anilino) naphthalene-6sulfonic acid(IAANS),Respectively.And then,the fluorescence emission(steady-state and time-resolved) was performed.MAIN OUTCOME MEASURE:The fluorescence properties of 5-IAF-labeled cTnC(C35S) and IAANS-labeled cTnC(C35S).RESULTS:The excitation of apo-cTnC(C35S)IAF was performed at 491 nm,and the emission peak was at 520 nm.Saturation of cTnC(C35S)IAF with Mg led to a 35% decrease in fluorescence intensity.Another 35% decrease with a 3 nm-blue shift was seen as the protein was saturated with Ca.The two-phase transitions of fluorescence emission from IAANS-labeled cTnC in response to Mg and Ca did not appear in fluorescence emission of 5-IAF-labeled cTnC.However,the Ca-induced conformational change in cTnC remained unchanged no matter which probe was used.Ca titration experiments showed that binding parameters derived from the fluorescence emission of the two probes were comparable.CONCLUSION:5-IAF is an appropriate probe that can be used to study the interaction between cardiac troponin C and other contractile regulatory proteins.

Objective To evaluate the effect of oxycodone postconditioning on myocardial ischemia-reperfusion (I/R) injury in rats.Methods Forty pathogen-free healthy adult male Sprague-Dawley rats,weighing 200-300 g,were randomly divided into 4 groups (n =10 each) using a random number table:sham operation group (group S),myocardial I/R group (group Ⅰ),oxycodone postconditioning group (group O),and selective protein kinase C inhibitor chelerythrine group (group CH).Myocardial ischemia was induced by 30 min occlusion of the left anterior descending branch of the coronary artery,followed by 120 min reperfusion.In group S,the left anterior descending branch of the coronary artery was only exposed but not ligated.In group CH,chelerythrine 5 mg/kg was injected intravenously and slowly via the jugular vein before ligation which was performed immediately after administration.In O and CH groups,oxycodone 0.5 mg/kg was injected intravenously and slowly via the jugular vein at 2 min before reperfusion.Arterial blood samples were taken at 120 min of reperfusion to detect the levels of cardiac troponin Ⅰ (cTnI) and creatine kinase-MB (CK-MB) in serum.The hearts were removed after the animals were sacrificed to measure the myocardial infarct size by TTC staining.Results Compared with group S,the levels of cTnI and CK-MB in serum and myocardial infarct size were significantly increased in Ⅰ,O and CH groups (P＜0.05).Compared with group Ⅰ,the levels of cTnI and CK-MB in serum and myocardial infarct size were significantly decreased in O and CH groups (P＜0.05).Compared with group O,the levels of cTnI and CK-MB in serum and myocardial infarct size were significantly increased in group CH (P＜0.05).Conclusion Oxycodone postconditioning can mitigate myocardial I/R injury in rats,and the mechanism is partially related to activation of protein kinase C signaling pathway.

Objective To evaluate the effect of oxycodone pretreatment on autophagy during renal ischemia-reperfusion (I/R) in rats.Methods Thirty-six SPF healthy adult male Wistar rats,aged 6-9 weeks,weighing 180-220 g,were divided into 3 groups (n=12 each) using a random number table:sham operation group (Sham group),I/R group and oxycodone pretreatment group (Oxy group).The left renal pedicles were clamped with atraumatic microclips for 45 min followed by reperfusion to establish the model of renal I/R injury in I/R and Oxy groups.Oxycodone 0.5 mg/kg was injected via the caudal vein at 15 min before ischemia in group Oxy,and the equal volume of normal saline was given instead in I/R and Sham groups.At 24 h of reperfusion,blood samples were collected from hearts for measurement of serum creatinine (Cr) and blood urea nitrogen (BUN) concentrations.The animals were then sacrificed and left renal tissues were obtained for examination of pathological changes (with a light microscope) and for determination of Bcl-2 and Beclin-1 expression (by immunohistochemistry).Results Compared with Sham group,the concentrations of serum Cr and BUN were significantly increased,and the expression of Bcl-2 and Beclin-1 in renal tissues was up-regulated at 24 h of reperfusion in I/R and Oxy groups (P<0.05).Compared with I/R group,the concentrations of serum Cr and BUN were significantly decreased,the expression of Bcl-2 in renal tissues was up-regulated,and the expression of Beclin-1 in renal tissues was down-regulated at 24 h of reperfusion (P<0.05),and the pathological changes were significantly attenuated in Oxy group.Conclusion Oxycodone pretreatment inhibits autophagy through up-regulating the expression of Bcl-2 and down-regulating the expression of Beclin-1,thus attenuating renal I/R injury in rats.

BACKGROUND:Shape memory polyurethane has good physical and chemical properties and compatibility, but there are relatively few reports on the compatibility of osteoblasts before and after the deformation-complex of the shape memory polyurethane. OBJECTIVE:To observe the compatibility of osteoblasts with shape memory polyurethane before and after the deformation-complex. METHODS: Shape memory polyurethane membranes were prepared, and its stretching-solid-complex was conducted under the experimental environment, to obtain the membrane materials after the deformation-complex. The Sprague-Dawley neonatal rat osteoblasts were inoculated on the shape memory polyurethane membranes before and after the deformation-complex. After 2 hours of culture, the number of adherent cels was counted, and cel spreading was observed; cel proliferation was determined after 1-11 days of culture. RESULTS AND CONCLUSION:The adhesion amount and proliferation activity of osteoblasts on shape memory polyurethane membranes after the deformation-complex were significantly higher than those before the deformation-complex (P < 0.05). The osteoblasts presented fusiform appearance on the shape memory polyurethane membranes after deformation-complex, and cel arrangement showed a clear orientation, but a smal spreading area; while the osteoblasts presented polygonal shape on the shape memory polyurethane membranes before deformation-complex, arranged in no particular direction, and spread largely. These findings show the shape memory polyurethane has better osteoblast compatibility after the deformation-complex.

Objective To investigate the effects of sinomenine on hind limb ischemia?reperfusion ( I∕R) injury and expression of Bcl?2 and Bax in skeletal muscle cells of rats. Methods Fifty?four healthy adult male Wistar rats, aged 6-8 weeks, weighing 180-220 g, were divided into 3 groups ( n=18 each) using a random number table: sham operation group ( group S) , group I∕R and sinomenine group ( group SIN) . The rats were subjected to 4 h of ischemia on the proximal part of the right hind limb using elastic rubber bands followed by reperfusion in I∕R and SIN groups. Sinomenine 60 mg∕kg was injected intraperito?neally at 30 min before reperfusion in group SIN, and the equal volume of normal saline was given instead of sinomenine at 30 min before reperfusion in S and I∕R groups. Immediately after onset of reperfusion and at 4 and 24 h of reperfusion, blood samples were collected from the cardiac apex to measure the concentra?tions of serum lactate dehydrogenase ( LDH) and creatine kinase ( CK) . The animals were sacrificed imme?diately after blood sampling, and the gastrocnemius specimens of the hind limb were immediately removed for determination of the wet to dry weight ratio ( W∕D ratio) and expression of Bcl?2 and Bax in gastrocnemi?us cells ( by immunohistochemistry) and for examination of the pathological changes after haematoxylin and eosin staining. The Bcl?2∕Bax ratio was calculated. Results Compared with group S, the gastrocnemius W∕D ratio and concentrations of serum LDH and CK were significantly increased, the expression of Bcl?2 was significantly down?regulated, the expression of Bax was significantly up?regulated, and the Bcl?2∕Bax
ratio was significantly decreased in I∕R and SIN groups ( P<0?05) . Compared with group I∕R, the gastroc?nemius W∕D ratio and concentrations of serum LDH and CK were significantly decreased, the expression of Bcl?2 was significantly up?regulated, the expression of Bax was significantly down?regulated, and the Bcl?2∕Bax ratio was significantly increased in group SIN ( P<0?05) . The pathological changes of the gastrocne?mius were significantly attenuated in group SIN as compared with group I∕R. Conclusion Sinomenine can attenuate hind limb I∕R injury, and the mechanism may be related to maintenance of the balance between Bcl?2 and Bax and to inhibition of apoptosis in skeletal muscle cells of rats.

Antigens, CD ; metabolism ; Diagnosis, Differential ; Female ; Humans ; Killer Cells, Natural ; pathology ; Leg ; Lymphoma, T-Cell, Cutaneous ; immunology ; pathology ; Middle Aged ; Skin Neoplasms ; immunology ; pathology

Objective To evaluate the efficacy of lidocaine solid lipid nanoparticles (L-SLNs) for sciatic nerve blockade in rats.Methods Lidocaine-loaded SLNs were prepared using high pressure homogenization.Ninety SPF male Wistar rats,weighing 220-280 g,were randomized into 6 groups (n =15 each) using a random number table:control group (group C),1％ L-SLN group (group L1-SLN),1％ lidocaine group (group L1),2％ L-SLN group (group L2-SLN),2％ lidocaine group (group L2),and blank SLN group (group SLN).In C,L1-SLN,L1,L2-SLN,L2 and SLN groups,normal saline,1％ lidocaine SLN,1％ lidocaine,2％ lidocaine SLN,2％ lidocaine and blank SLN (200 μl) were injected,respectively,around the sciatic nerve.Before sciatic nerve blockade (baseline) and at 10,20,30,60,120,180,240,300,360,420,480,540 and 600 min after blockade,the paw withdraw latency to a thermal stimulus was measured,and maximum possible effect (MPE) was calculated to reflect the degree of sensory block.Before sciatic nerve blockade and at 10,20,30,60,120 and 150 min after blockade,extensor postural thrust (EPT) of the hind limbs was detected to reflect the degree of motor block.The sciatic nerve at the injection site and the tissues around the site were obtained for observation of the pathological changes at 2 days and 1 and 4 weeks after blockade.Results Compared with the baseline value before blockade and group C,the MPE was significantly increased in at 10-30 min after blockade group L1,at 10-60 min after blockade in group L2,at 10-360 min after blockade in group L1-SLN,and at 10-540 min after blockade in group L2-SLN,and the EPT was decreased at 10-30 min after blockade in group L1,at 10-60 min after blockade in group L2 and group L1-SLN,and at 10-90 min after blockade in group L2-SLN.Compared with group L1,the MPE was significantly decreased at 10 min after blockade,no significant change was found at 20-30 min after blockade,and the MPE was increased at 60-360 min after blockade,and the EPT was increased at 10-30 min after blockade,and no significant change was found at the other time points in group L1-SLN.Compared with group L2,no significant change was found in the MPE at 10-30 min after blockade,the MPE was significantly increased at 60-540 minafter blockade,and the EPT was increased at 10-60 min after blockade,and no significant change was found at the other time points in L2-SLN group.In SLN,L1-SLN and L2-SLN groups,no pathological changes were found in the sciatic nerve at the injection site and the tissues around the site,and only mild inflammatory responses were observed.Conclusion L-SLNs can prolong the duration of block when applied for sciatic nerve blockade in rats and biocompatibility is good.

Objective To investigate the morphological effect of fluid shear stress on pig iliac endothelium cells cultured solely or co-cultured with pig small intestinal submucosa.Methods The shear stress of 40×10-5 N/cm2 were carried out for 12 h on both groups.The images were recorded every 30 min.The directional angles were calculated.Results In the group of cell cultured solely:The defluvium of cells was obvious at the 1st hour,but the shape of cells didn't change.At the 4th hour,the defluvium of cells was little,the cell became round from its initiatory polygon shape.At the 8th hour,the defluvium of cell could not be observed.The shape of cells became fusiform and gracile.The cells arranged along the direction of flow field in the local area.At the 12th hour,the cells became more and more gracile.The trend of realignment of cells along the direction of flow field was obviously.The directional angles of cells at the 12th hour was significantly different from the zero hour.In the group of cell co-cultured with small intestinal submucosa:At the 1st hour,some of cells were brushed off mildly.The defluvium of cells could not been observed since the 2nd hour.The directional angles didn't change significantly in the 12 hours.Conclusion The shear stress of 40×10-55 N/cm2 cannot influence the cell of co-cultured but do influence the cell cultured solely.

Objective To explore the role of p16 gene methylation in fibroblasts in the occurrence and development of keloid.Methods Skin tissue specimens were resected from the lesions of patients with keloid and normal skin of healthy human controls.Fibroblasts were isolated from these tissue specimens and subjected a primary culture.An immunohistochemical analysis was performed to measure the expression of p16 protein in tissue specimens,real-time fluorescence-based quantitative PCR to determine the mRNA expression level (expressed as 2-△△Ct) of p 16 and DNA methyltransferases (DNMTs) in fibmblasts,and bisulfite sequencing PCR (BSP) to estimate the methylation status of p16 gene in the tissue specimens and primary fibroblasts.Results The keloid fibroblasts (KFbs) showed significandy lower mRNA expression of p16 gene (0.64 ± 0.18 vs.1.92 ± 0.23,t =10.54,P＜ 0.05),but significantly higher mRNA expressions of 3 DNMTs (DNMT1:2.58 ± 0.23 vs.1.13 ± 0.21,t =11.22,P ＜ 0.05; DNMT3A:4.87 ± 0.46 vs.2.38 ± 0.32,t =10.81,P＜ 0.05; DNMT3B:1.57 ± 0.12 vs.0.57 ± 0.16,t =12.45,P＜ 0.05) compared with the normal fibmblasts (NFbs).The DNA methylation rate in the p16 gene promoter region was significantly increased in keloid tissue (1.81％ ± 0.46％) and KFbs (3.15％ ± 0.94％) compared with normal skin tissue (0.90％ ± 0.35％,F =14.23,P＜ 0.01) and NFbs (0.17％ ± 0.29％,F=37.62,P＜ 0.01).Conclusions The methylation and low expression of p16 gene in KFbs may be associated with the uncontrolled growth of keloid,and DNMTs may play a role in the pathogenesis of keloid.