Effect of herpesvirus infection on pancreatic duct cell secretion

AIM： To examine the effect of acute infection caused by herpesvirus （pseudorabies virus, PRV） on pancreatic ductal secretion. METHODS： The virulent Ba-DupGreen （BDG） and non- virulent Ka-RREp01acgfp （KEG） genetically modified strains of PRV were used in this study and both of them contain the gene for green fluorescent protein （GFP）. Small intra/ interlobular ducts were infected with BDG virus （10^7 PFU/mL for 6 h） or with KEG virus （10^10 PFU/mL for 6 h）, while non-infected ducts were incubated only with the culture media. The ducts were then cultured for a further 18 h. The rate of HCO3 secretion [base efflux -λ（B）] was determined from the buffering capacity of the cells and the initial rate of intracellular acidification （1） after sudden blockage of basolateral base loaders with dihydro-4,4,- diisothiocyanatostilbene-2,2,-disulfonic acid （500 μmol/L） and amiloride （200 μmol/L）, and （2） after alkali loading the ducts by exposure to NH4Cl. All the experiments were performed in HCO3-buffered Ringer solution at 37 ℃ （n = 5 ducts for each experimental condition）. Viral structural proteins were visualized by immunohistochemistry. Virallyencoded GFP and immunofluorescence signals were recorded by a confocal laser scanning microscope.RESULTS： The BDG virus infected the majority of accessible cells of the duct as judged by the appearance of GFP and viral anUgens in the ductal cells. KEG virus caused a similarly high efficiency of infection. After blockage of basolateral base loaders, BDG infection significantly elevated -λB-） 24 h after the infection, compared to the non-infected group. However, KEG infection did not modify -λB-）. After alkali loading the ducts, -λB-） was significantly elevated in the BDG group compared to the control group 24 h after the infection. As we found with the inhibitor stop method, no change was observed in the group KEG compared to the non-infected group. CONCLUSION： Incubation with the BDG or KEG strains of PRV results in an effective infection of ductal epithelial cells. The BDG strain of PRV, which is able to initiate a lytic viral cycle, stimulates HCO3 secretion in guinea pig pancreatic duct by about fourto fivefold, 24 h after the infection. However, the KEG strain of PRV, which can infect, but fails to replicate, has no effect on HCO3 secretion. We suggest that this response of pancreatic ducts to virulent PRV infection may represent a defense mechanism against invasive pathogens to avoid pancreatic injury.

EFFECTS OF ELECTRO-ACUPUNCTURE ON SOMATOSTATIN AND PANCREATIC POLYPEPTIDE IN ISCHEMIC CEREBROVASCULAR DISEASES

The levels of somatostatin(SS)in CSF and blood and pancreatic polypeptide(PP)inplasma were measured by radioimmunoassay in 64 patients with acute ischemiccerebrovascular diseases(ICVD),randomly divided into two groups:group 1(n=31,bothelectro-acupuncture and routine treatments given)and group 2(n=33,routine treatment)and 26 non-ICVD patients were used as controls.The points of electro-acupuncture wereQuchi(LI 12),Waiguan(SJ 5)and Huantiao(GB 30)and Zusanli(St 36).After a courseof treatment,the SS levels in plasma and CSF were significantly increased in the patientsof group 1 with good result and their plasma PP level had no significant change.In thepatients with poor result,however,the PP level was significantly decreased.The resultssuggested that electro-acupuncture might play an active role in alleviating the SSmetabolic disturbance in CNS of ICVD patients.

Small serotonin-positive pancreatic endocrine tumors caused obstruction of the main pancreatic duct

We report 2 cases of pancreatic endocrine tumors that caused obstruction of the main pancreatic duct(MPD).A 49-year-old asymptomatic man was referred to our institution because dilation of the MPD was revealed by abdominal ultrasonography(US).No tumor was detected by endoscopic ultrasonography,computed tomography(CT),and magnetic resonance imaging(MRI).The diameter of the MPD was > 20 mm at the body,and no dilation was noted at the head.Although malignancy was not confirmed through cytology or imaging,pancreatic cancer was strongly suspected.Pancreaticoduo-denectomy was performed.Pathological and immunohistochemical examination revealed a 5 mm × 3 mm serotonin-positive endocrine tumor.Fibrosis was present around the MPD and seemed to cause stricture.A 32-year-old asymptomatic man had elevated serum amylase,and US demonstrated dilation of the MPD.No tumor was detected by CT and MRI.Pancreatic cancer was suspected due to stricture and dilation of the MPD.Pancreatectomy of middle part of pancreas was performed.Pathological and immunohistochemical examination revealed a serotonin-positive endocrine tumor sized 5 mm × 4 mm.We report 2 cases of serotonin-positive pancreatic endocrine tumors that caused stricture of the MPD in spite of the small size of the tumor.