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W H Marks

Publications and source records attributed to W H Marks.

63 records · Page 4Linked to original sources
PubMed1983

A radioimmunoassay for rat pancreatic secretory trypsin inhibitor.

A radioimmunoassay for the detection of pancreatic secretory trypsin inhibitor (PSTI) in the rat is described. The sensitivity of the assay enables the specific measurement of this inhibitor in the serum of normal rats. The average base-line value for multiple animal serum specimens taken from fasting female Wistar rats being fed conventional diets was 11.6 +/- 6.2 micrograms/l. The inhibitor existed in its free form in serum, and PSTI immunoreactivity increased significantly within 2 h of the induction of experimental pancreatitis. The present assay will facilitate the study of PSTI in experimental diseases of the pancreas.

Animals↗
PubMed1983

Elimination of pancreatic secretory trypsin inhibitor from the circulation. A study in man.

The elimination of human pancreatic secretory trypsin inhibitor (PSTI) from the circulation of man has been examined in two human volunteers. Serial samplings of blood and urine were made for 55 h, after a rapid intravenous infusion of 125I-labeled human PSTI. The findings demonstrated a rapid initial elimination from the circulation. Within 30 min only 30% of the infused label remained (T1/2, 6 min). This was accompanied by the rapid appearance in the urine of radiolabel. Our results indicate that PSTI would prove a poor diagnostic marker for acute pancreatitis late in the course of the disease. This is opposed to the findings of Ogawa et al., who reported prolonged elevated circulating levels of PSTI weeks into the disease. However, they also noted rises of PSTI during acute pancreatitis in excess of 10 times the levels we have noted. Further exploration of population differences and the behavior of PSTI during acute pancreatitis are necessary to help resolve these findings.

Acute Disease↗
PubMed1982

Isolation and partial characterization of the pancreatic secretory trypsin inhibitor in the rat.

Isolation in a 55% yield of the low molecular weight pancreatic secretory trypsin inhibitor was achieved by gel filtration of an acid extract of whole inactive rat pancreas juice on Sephadex G-50 at pH 2.5 followed by desalting and ion-exchange chromatography on SP Sephadex C-50 at pH 4.5. Two distinct chromatographic fractions were obtained, labeled fraction 1 and 2. Fractions 1 and 2 showed three, respectively two, distinct closely migrating cationic bands on gel electrophoresis in barbital buffer, pH 8.6. Each fraction demonstrated one band on polyacrylamide disc electrophoresis at pH 4.6. The inhibitor is homogenous on gel filtration and on the basis of its stoichiometry with active site titrated rat anionic trypsin. Its molecular weight is approx. 6024. The amino acid composition is included. Rat pancreatic secretory trypsin inhibitor is trypsin-specific and interacts on a 1:1 molar basis with rat trypsin. It is a good inhibitor of bovine trypsin but a poor inhibitor of human cationic trypsin and its binding to trypsin is reversible by acidification. Like other inhibitors of this sort, it is present in about 0.1-0.2% of the total protein content of the juice, and normally exists in its free form. A simple procedure for the production of antiserum to the inhibitor which is a poor antigen is also described.

Amino Acids↗
PubMed1981

Studies on the interaction of Trasylol (aprotinin) with trypsin-pancreatic secretory trypsin inhibitor (PSTI) complexes and with alpha 2-macroglobulin-trypsin-PSTI-complexes.

An investigation was performed to study the interaction of Trasylol with both trypsin-pancreatic secretory trypsin inhibitor (PSTI) and alpha 2-macroglobulin (alpha 2-M)-trypsin-PSTI complexes. Trasylol was readily able to displace immunogenic PSTI from a complex with trypsin in vitro. A similar scale of displacement of PSTI by Trasylol from alpha 2-M-trypsin-PSTI complexes could not be demonstrated. Using complexes manufactured in vitro with 125I-labelled PSTI, we found that only a small percentage of the PSTI label could be liberated, even when presented with amounts of Trasylol in a 10-molar excess to the PSTI.

Aprotinin↗
PubMed1975

Cytotoxic principles of Parquetina nigrescens (Afzel.) Bullock (Asclepiadaceae).

Systematic fractionation of the cytotoxic extracts of the roots of Parquetina nigrescens (Afzel.) Bullock (Asclepiadaceae) on silica gel column chromatography led to the isolation of three cardenolides: cymarin, strophanthidin, and a strophanthidin glycoside (XS-89). Also isolated during the investigation were beta-sitosterol-beta-D-glucoside, a mixture of alpha- and beta-amyrins, a mixture of alkanols, and a mixture of plant sterols.

Animals↗