ABSTRACT
OBJECTIVE: Pancreatic stellate cells (PSC) are considered as the principal effector cells in pancreatic fibrosis. We studied the role of platelet-derived growth factor (PDGF) in the activation of PSC. METHODS: Cultured rat PSC were co-incubated with PDGF-BB (25 ng/mL) and different doses (0-40 ng/mL) of PD98059, a specific inhibitor of extracellular signal-regulated kinase (ERK). Expressions of p ERK1 protein and of collagen a1(I) mRNA were measured. RESULTS: Expression of p ERK1 protein was up-regulated by PDGF-BB, and was down-regulated in a dose-dependent manner by PD98059. Expression of collagen a1(I) mRNA also showed an increase with PDGF-BB and non-dose-dependent inhibition by PD98059. CONCLUSION: Our findings suggest that PSC activation is mediated by PDGF signal pathway, and ERK1 protein plays an important role in this activation.
Subject(s)
Animals , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Collagen Type I/antagonists & inhibitors , Flavonoids/pharmacology , Male , Pancreas/cytology , Platelet-Derived Growth Factor/pharmacology , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , eIF-2 Kinase/antagonists & inhibitorsABSTRACT
The correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient (A-aDO2) in rats with hepatopulmonary syndrome was investigated. Animals were divided into 2 groups: Sham-operated (Sham) group and common bile duct ligation (CBDL) group. Arterial blood gas was evaluated by a blood gas analyzer. The concentrations of ET-1 in blood and lung tissue sample were evaluated by radioimmunoassay. The distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were examined by in situ hybridization. The results showed that the level of A-aDO2 was higher in CBDL group than that in Sham group (P 0.05), while that of ETRB was higher in CBDL group than in Sham group (0.58 +/- 0.16 vs 0.28 +/- 0.07, P < 0.05). The expression of ETRB in lung was positively correlated with A-aDO2 (P < 0.05). It was concluded that the widened A-aDO2 may be related with enhancement of the expression of ETRB in lung.
Subject(s)
Endothelin-1/metabolism , Hepatopulmonary Syndrome/metabolism , Lung/metabolism , Oxygen/metabolism , Pulmonary Alveoli/metabolism , Rats, Wistar , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/metabolismABSTRACT
Summary: To determine the biological effects of extracelluar signal regulated kinase (ERK) specific inhibitor PD98059 on pancreatic stellate cells (PSCs) activated by platelet-derived factor-BB (PDGF-BB), cultured rat PSCs were co-incubated at 37 ℃ for 24 h with 25 ng/ml PDGF-BB and different doses of PD98059 (ranging from 5 ng/ml to 40 ng/ml). Expression of pERK1 protein was detected by Western blot and collagen α1 (Ⅰ) mRNA was tested by reverse transcription-polymerase chain reaction (RT-PCR). Our results showed that there were statistical differences in the expression of pERK1 protein in all groups. Expression of pERK1 protein was up-regulated in the group treated by PDGF-BB, and gradually down-regulated in the other groups treated by PD98059 of different doses. An excellent positive correlation was revealed between the inhibitory effect and PD98059 concentrations. It was also observed that the expression of collagen α1 (Ⅰ) mRNA had similar response to pERK1. The level of collagen α1 (Ⅰ) mRNA was the highest in the PDGF-BB group, and gradually reduced in the other groups treated by PD98059 of different doses. It is concluded that expression of pERK1 protein and collagen α1 (Ⅰ) mRNA was up-regulated in rat PSCs activated by PDGF-BB. Meanwhile, PD98059 could inhibit PSCs activation mediated by PDGF. It is suggested that ERK1 protein plays an important role on PSCs activation mediated by PDGF signal pathway.
ABSTRACT
The correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient (A-aDO2) in rats with hepatopulmonary syndrome was investigated. Animals were divided into 2 groups: Sham-operated (Sham) group and common bile duct ligation (CBDL) group. Arterial blood gas was evaluated by a blood gas analyzer. The concentrations of ET-1 in blood and lung tissue sample were evaluated by radioimmunoassay. The distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were examined by in situ hybridization. The results showed that the level of A-aDO2 was higher in CBDL group than that in Sham group (P＜0.05).The levels of plasma and pulmonary ET-1 in CBDL group were both higher than in Sham group (P ＜0.05). There was no significant difference in average A of ETRA between two groups by imaging analysis (0.21±0.06 vs 0.22±0.08, P＞0.05), while that of ETRB was higher in CBDL group than in Sham group (0. 58±0.16 vs 0.28±0.07, P＜0.05). The expression of ETRB in lung was positively correlated with A-aDO2 (P＜0.05). It was concluded that the widened A-aDO2 may be related with enhancement of the expression of ETRB in lung.
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<p><b>OBJECTIVE</b>To assess the feasibility of laparoscopic total mesorectal excision (TME) for low or ultralow anterior resection of rectal cancer.</p><p><b>METHODS</b>Excision of the mesorectum and low (ultralow) colo-anal anastomoses were performed laparoscopically in 62 patients with low rectal cancer based on the concept of TME and double stapling technique (DST).</p><p><b>RESULTS</b>Sixty-two operations with TME and DST were performed in a totally laparoscopic manner, and only one was converted to open procedures because of dysfunction of coagulation. The operative time was 125 min (110-210 min) and the operative blood loss 20 ml (5-80 ml). The time for bowel function recovery and post-operatively dietary intake was 1-2 days. Twenty-eight patients received postoperative analgesics. Average hospital stay was 8 days (5-14 days). Complications were observed in only 2 of the 62 patients, one had suffered from urinary retention and the other, anastomotic leakage.</p><p><b>CONCLUSIONS</b>Totally laparoscopic excision of the mesorectum for low or ultralow anterior resection of rectal cancer is a minimally invasive technique with sphincter preservation, less postoperative pain, and rapid recovery.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Anal Canal , General Surgery , Anastomosis, Surgical , Methods , Colon , General Surgery , Laparoscopy , Rectal Neoplasms , General Surgery , Treatment OutcomeABSTRACT
Objective To observe the expression changes of cytokine RhoA,stress fiber and Vinculin in the formation of hepatic fibrosis in rats, and investigate the role of RhoA in hepatic fibrosis. Methods Forty male SD rats were divided into two groups:model group and control group. The rats in the model group were given 60% CCl 4 by subcutaneous injection(1 ml/kg). The liver tissue was taken out for research at 1st、4th and 8th week respectively, RhoA and Vinculin mRNAs were detected by RT PCR, Vinculin and F actin proteins were detected by immunohistochemistry and immunofluorescence respectively, RhoA and Vinculin proteins were detected by Western blotting. Results Compared with control group, the expressions of mRNA of RhoA and Vinculin, the proteins of Vinculin, F actin and RhoA were all significantly increased( P
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AIM: To investigate the different vasoactive effects of nitric oxide (NO) and endothelin (ET) on splanchnic arterial and venous vessels in cirrhotic rats. METHODS: Cirrhosis was induced in Wistar rats by subcutaneously administration of carbon tetrachloride. Maximal relaxation (Rmax) and contraction (Cmax) to NO and ET were determined in vitro using isolated vascular strips prepared from portal vein (PV) and mesenteric artery (MA) of both cirrhotic and normal rats, and EC50 was calculated for effects of NO and ET, respectively. RESULTS: Rmax of PV and MA to sodium nitroprusside (SNP) (releasing NO) were significantly higher in cirrhotic rats (n=8) than those in normal rats (n=7), and EC50 of NO were dramatically lower in cirrhotic rats than those in control (P
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Objective To investigate the patterns of mesorectum lymph node (LN) metastases of rectal cancer. Methods Rectal cancer specimens obtained by total mesorectum excision were treated with lymph node revealing solution to retrieve all the nodes, and examined by routine pathology and immunohistochemical staining. Results A total of 443 LN in 26 specimens were harvested, with 128 nodes(28 9%)in 23 cases (88 5%) found positive. Positive nodes with the size less than 5 mm accounted for 59%. Among the 23 metastatic cases, there were 14 cases with tumors locating in the posterior wall, 69 out of 71 positive nodes were found along the superior rectal artery. In the other 9 cases, tumors were found in the lateral wall, 29 out of 57 positive nodes were found around ipsilateral branches of superior rectal artery,7 were around the contralateral branches, 4 were around the ipsilateral branches of middle rectal artery. Conclusions Most positive LN were less than 0 5 cm in diameter. LN metastasis of rectal cancer have close relationship with tumor location. Tumors in the posterior wall tend to spread upward along the superior rectal artery, while tumors in the lateral wall may have upward and lateral LN metastases simultaneously, with most metastatic LN found ipsilaterally.
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Aim To evaluate the effect of 15d-PGJ2 on up-regulated expression of PPAR? and inducing HSC apoptosis and inhibiting HSC proliferation. Methods The rat liver stellate cell line (HSC-T6) was cultured in DMEM, and treated with PPAR? agonist 15d-PGJ2 of different concentrations. The expression of PPAR? mRNA was detected by RT-PCR. The protein expression of NF-?B was examined by Western blot. The cell proliferation rate of HSC-T6 was determined by MTT colorimetric assay. The cell cycle and apoptosis ratio were measured using flow cyto -metry analysis. Results The proliferation rate of the rat liver stellate cell line (HSC-T6) was significantly inhibited by 15d-PGJ2 (vs controls, P