Human chorionic gonadotropin (hCG) induces MAPK3/1 phosphorylation in the zebrafish ovarian follicle cells independent of EGF/EGFR pathway.

In mammals, human chorionic gonadotropin (hCG), a luteinizing hormone (LH) analogue, induces MAPK3/1 phosphorylation in the granulosa cells and this event is largely dependent on epidermal growth factor receptor (EGFR) activity. However, whether this mechanism also works in other vertebrates such as fish remains unknown. Here, we showed that treatment of cultured zebrafish ovarian follicle cells with hCG also resulted in MAPK3/1 phosphorylation without affecting the total protein level of MAPK3/1. The phosphorylation level peaked at 5 min and then declined to the basal level after 40 min of hCG treatment. Further experiment showed that H89 (a PKA inhibitor) could abolish hCG-stimulated MAPK3/1 phosphorylation, but had no effect on EGF-induced phosphorylation, suggesting a mediating role for cAMP/PKA in hCG activation of MAPK3/1. On the other hand, AG1478 (an EGFR inhibitor) completely blocked EGF-stimulated MAPK3/1 phosphorylation, but had no effect on the hCG-induced MAPK3/1 phosphorylation. These data indicate that similar to its action in mammals, hCG/LH also stimulated MAPK3/1 phosphorylation in the zebrafish ovarian follicle cells; however, unlike the situation in the mammalian ovary, the hCG-stimulated MAPK3/1 phosphorylation in cultured zebrafish ovarian follicle cells was independent of EGFR.

Epidermal growth factor differentially regulates activin subunits in the zebrafish ovarian follicle cells via diverse signaling pathways.

Epidermal growth factor (EGF) promotes oocyte maturation in the zebrafish and its effect is mediated via the activin system. However, the mechanisms by which EGF regulates activin subunits in the follicle cells remain unknown. The present study demonstrated that EGF controlled expression of three activin subunits (inhbaa, inhbab and inhbb) in the follicle cells via diverse signaling pathways. The expression of inhbaa and inhbb was often co-regulated via similar pathways. Suppression of MAPK3/1, p38 MAPK, PKC and PKA each blocked or partially reduced the stimulatory effects of EGF on the expression of inhbaa and inhbb while up-regulated that of inhbab. Conversely, inhibition of PI3K did not have any effect on the expression of inhbaa and inhbb but significantly suppressed the stimulatory effect of EGF on inhbab. In summary, EGF action in the zebrafish ovary involves activin system and its regulation of activin subunits is mediated by diverse signaling pathways downstream of EGFR.

Laparoscopic intragastric approach for stromal tumours located at the posterior gastric wall.

Surgical resection is indicated for gastrointestinal stromal tumour (GIST). Laparoscopic resection with clear margins is effective in gastric GIST. However, GIST located in the posterior gastric wall with close proximity to the oesophagogastric junction poses special challenges. Laparoscopic intragastric resection offers a new approach to the management of these tumours. The surgical technique, our experience and a summary of the literature are presented.

Randomized trial comparing pantoprazole infusion, bolus and no treatment on gastric pH and recurrent bleeding in peptic ulcers.

BACKGROUND: To study the effects of pantoprazole on gastric pH and recurrent bleeding after endoscopic treatment for bleeding peptic ulcers. METHODS: After endoscopic haemostasis, patients were randomly assigned to infusion group (pantoprazole 80 mg i.v. bolus followed by continuous infusion of 8 mg/h for 3 days), bolus group (pantoprazole 80 mg i.v. bolus followed by 40 mg i.v. bolus every 12 h for 3 days) and no-treatment group (no acid suppression in the first 3 days). Gastric pH was monitored. Rebleeding rate within 30 days, the need for surgery, transfusion requirement, total hospital stay, mortality rate and gastric pH were compared. RESULTS: One hundred and sixty-eight patients were included, with 15 patients excluded from the analysis. There were 54 patients in the infusion group, 49 in the bolus group and 50 in the no-treatment group. There was fewer rebleeding (3.7 vs 16.0%, P = 0.034), less operative intervention (0 vs 8.0%, P = 0.034) and shorter hospital stay (6.4 vs 8.2 days, P = 0.040) in the infusion group compared with that in no-treatment group. When the bolus group was compared with no-treatment group, there were fewer rebleed (4.1 vs 16.0%, P = 0.049) and less blood transfusion (1.5 vs 2.9 units, P = 0.007). There was no difference in mortality among the three groups. Patients who received either pantoprazole infusion or bolus had significantly higher mean pH and longer duration of pH above 6 compared with the no-treatment group. There was no difference in the rebleeding rate, transfusion requirement, need for operation and hospital stay between the infusion and bolus groups. The mean pH and the duration of pH above 6 were also similar. CONCLUSION: Pantoprazole either as infusion or bolus decreased rebleeding after endoscopic treatment for bleeding peptic ulcer.

Biliary papillomatosis: report of seven cases and review of English literature.

Biliary papillomatosis is rare. Before 1993, there were only 21 cases reported in the English literature. This article reports our experience in managing this disease and reviews experiences from recent English literature. A retrospective review of patients with biliary papillomatosis was conducted in our institution. A search of the English literature between 1993 and 2002 was performed in the MEDLINE database using "biliary papillomatosis" as the keyword. Seven patients with biliary papillomatosis were treated in our hospital. Another 50 cases were reported in the recent literature. This amounted to a total of 78 cases so far reported. The male to female ratio was approximately 2 : 1. The mean age at presentation was 63 years. Most patients presented typically with cholangitis. Malignant change was present in 33 patients (42%). Concomitant intrahepatic and extrahepatic disease was noticed in 33 patients (42%). The overall resection rate was 55%. The mean survival was 28 months following resection, irrespective of histological type. Patients without tumor resection had a poorer survival of less than 11 months. Biliary papillomatosis presents typically with biliary obstruction and it occurs most often in elderly males. Resection is recommended because of the considerable malignancy rate, diffuse pattern of disease, and better survival following curative surgery. Malignant histology is not always associated with a poorer prognosis provided that radical resection can be achieved.