Pancreatic stone predominantly composed of fatty acid calcium

Pancreatic stone protein/regenerating protein family in pancreatic and gastrointestinal diseases

Pancreatic stone protein (PSP; reported in 1979), pancreatitis-associated protein (PAP; 1984) and regenerating protein (Reg I; 1988) were discovered independently in the fields of the exocrine (pancreatitis) and endocrine (diabetes) pancreas. Subsequent analysis revealed that PSP and Reg I are identical and PAP belongs to the same protein family. PSP/Reg I and PAP share a selective and specific trypsin cleavage site and result in insoluble fibrils (PTP, PATP). Search for a functional role of PSP had led to the idea that it might serve as an inhibitor in pancreatic stone formation and PSP was renamed lithostathine. Inhibitory effects of lithostathine in stone formation have been questioned. Evidence so far obtained can support a lithogenic role rather than a lithostatic role of PSP. PAP and its isoforms have been investigated mainly regarding responses to inflammation and stress. Reg I and its isoforms have been examined on regeneration, growth and mitogenesis in gastrointestinal neoplastic diseases as well as diabetes. Evidence obtained can be applied in the prediction of prognosis and therapy for inflammatory and neoplastic diseases.

Endoscopic treatment of pancreatic stones in patients with chronic pancreatitis

BACKGROUND

The aim of our study was to evaluate the long-term results of endoscopic pancreatic stone removal in patients with chronic pancreatitis.

METHODS

We retrospectively included 53 patients with chronic pancreatitis, in whom an attempt was made at endoscopic stone removal between 1984 and 1993. Patients presented with pain (30) or an exacerbation of pancreatitis (23). A sphincterotomy was performed in 41 patients. A nasopancreatic drain was left in situ for saline flushing in 6 patients. A pancreatic stent was inserted beyond the stones in 28 patients. Fragmentation of stones was performed by mechanical lithotripsy in 4 patients or by extracorporeal shock wave lithotripsy in 8 patients.

RESULTS

All patients had pancreatic stones (multiple 33, single 20) with proximal dilatation of the pancreatic duct. Median follow-up was 33 months (range 4 to 131). Stone removal was successful in 42 patients (79%) (complete 39, partial 3) with relief of symptoms in 38 of 42 (90%). The remaining 4 patients had pancreatic surgery. Stone removal failed in 11 patients and 3 of 11 patients had symptomatic improvement. The remaining 8 patients needed either pancreatic surgery (4) or continued conservative treatment (4). Thirteen of the 53 patients (25%) had recurrent stones, which could be removed endoscopically in 10 of 13. Procedure-related complications occurred in 5 of 53 patients (9%). Mortality was 0%. Seven of the 28 stented patients (25%) had stent-related complications.

CONCLUSIONS

Endoscopic treatment of pancreatic stones is a valid approach in patients with pancreatic lithiasis with an acceptable risk profile.

Trypsin(ogen) content of pancreatic calculi in chronic calcified pancreatitis in man

Protein analysis of intraductal precipitates and calculi is important to elucidate the mechanism of stone formation in chronic pancreatitis. We revealed human cationic trypsin immunoreactivity in protein extracts of pancreatic stones from 11 of 13 patients with chronic calcified pancreatitis, ranging from 0 to 42.3 ng/micrograms protein. On gel filtration the immunoreactivity eluted as one peak, which is identical to that of human cationic trypsinogen. On immunostaining of pancreatic stone, using an immunogold technic and scanning electron microscopy, the immunoreactivity was observed more densely in the amorphous portion of the center of the stones than in the concentric laminar layer of the periphery. Only negligible activity was detected for elastase 1 or amylase in the stone extracts. These results suggest that the presence of trypsinogen in pancreatic stone is not due to coprecipitation or adsorption of pancreatic enzymes but that trypsinogen is more likely involved in an initial step of intraductal precipitate formation than in a subsequent step of stone formation. However, the absence of trypsinogen in the stones from two of the 13 patients also suggests that trypsinogen is not the sole protein initiating precipitate formation.

Movement of intrapancreatic calcium in dogs with experimental pancreatic lithiasis. With special reference to the process of pancreatic calculus formation

This study was performed to clarify the movement of calcium in the pancreas of dogs with chronic pancreatitis, using scanning and transmission electron microscopes (SEM, TEM) equipped with X-ray elemental microanalyzers. Eleven adult mongrel dogs underwent incomplete ligation of the pancreatic duct. After the procedure, the levels of pancreatic enzymes in the serum did not change for 9 mo, but the endocrine function was reduced gradually. Of all dogs, 5 revealed pancreatic sclerosis, and 2 at 9 mo had calculi, 2-4 mm in size, in the small pancreatic duct. SEM examination revealed the intralobular fibrosis and irregularity of the pancreatic duct wall, and TEM examination revealed the intralobular fibrosis and irregularity of the pancreatic duct wall, and TEM examination demonstrated the amorphous or crystalloid substances and secreted granules in the acinar lumen or ductule. In elemental analysis spectra using SEM, a high calcium peak was seen in the pancreatic duct wall. In elemental analysis spectra using TEM, a high calcium peak was observed in the amorphous or crystalloid substances, and a high ratio of Ca/K was seen in these substances. Calcium was also detected in the secreted granules or microvilli. These results suggest that there is a process of calculus formation based on the congregation of the intraductular substances containing a large quantity of calcium.