The fine structure of pancreatic stones as shown by scanning electron microscopy and x-ray probe microanalyser
SummaryTo delineate the process of pancreatic stone formation, stones from four patients were studied with a scanning electron microscope and X-ray probe microanalyser.The stones consisted of a central core and surrounding shell. Two kinds of stones were demonstrated:one had a core composed of a calcium-rich amorphous substance and interlacing fibrils; the other had a core consisting of multiple cavities with smooth walls composed of a calcium-deficient amorphous substance.The shells showed a common structure: zones of layers or bands of a calcium-rich amorphous substance, network fibrils filled with a calcium-rich amorphous substance, and laminated parallelogrammic or polygonal plates of calcite parallel to the surface in one layer and oblique or perpendicular in the next layer. Calcium was in the crypto-crystalline state as well as crystalline state of calcite. Crystalline calcite showed spiral and epitaxial growth along with findings of dissolution, resembling cholesterol crystals of gall stones. Pancreatic stones are probably formed through central core formation and layered growth of a shell. Comparison of stones and protein plugs suggests that protein plugs can grow to stones with calcite deposition accompanied by precipitation of network fibrils and an amorphous substance.
The calcium concentration in human pure pancreatic juice in chronic pancreatitis
SummaryCalcium concentration in human pure pancreatic juice was determined during wash-out period, secretin stimulation and pancreozymin stimulation.Specimens were collected by endoscopic retrograde catheterization of the papilla at one minute intervals for 20 minutes after intravenous injection of secretin (Eisai, 1 U/kg) and for 10 minutes after pancreozymin injection (Boots, 1 U/kg). The determination was also made in duodenal juice obtained during the ordinary pancreozymin-secretin test. Calcium concentration in duodenal juice was significantly raised in patients with chronic pancreatitis (suspected, definite or calcifying), confirming the results of previous investigators. Calcium concentration and calcium per mg of protein in human pure pancreatic juice were significantly raised in patients with chronic pancreatitis (suspected, definite or calcifying). Calcium per mg of protein in normal human pure pancreatic juice was quite similar to that reported in zymogen granules of the guinea-pig pancreas. Calcium output in human pure pancreatic juice was also significantly raised in patients with suspected chronic pancreatitis; it was within normal limits in patients with definite or calcifying chronic pancreatitis due to decreased volume output. Significance of these findings were discussed in relation to pathogenesis and early detection of chronic pancreatitis.
Studies on human pure pancreatic juice collected by endoscopic retrograde catheterization of the papilla
SummaryPure pancreatic juice was collected from 8 subjects by endoscopic retrograde cannulation of the papilla. Samples were collected at 1 minute intervals for 20 minutes after rapid intravenous injection of secretin (Eisai, 1 u/kg) and for 10 to 15 minutes after rapid intravenous injection of CCK-PZ (1 U/kg). Three hydrolases (amylase, chymotrypsinogen and lipase) showed nonparallel secretory pattern.Lipase was proportionally more stimulated than chymotrypsinogen and chymotrypsinogen was more stimulated than amylase by CCK-PZ stimulation. However, in one subject the secretion of three hydrolases was parallel and in another subject lipase and chymotrypsinogen showed parallelism. Samples collected at “wash out” period showed quite high enzyme and protein concentration with specific activity and enzyme ratio not different from those of samples collected at peak period of CCK-PZ stimulation. Normal ranges were estimated in peak flow rate per minute, peak enzyme concentration, specific activity of enzymes, maximal enzyme output per minute and maximal bicarbonate concentration.