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J G Shearen

Publications and source records attributed to J G Shearen.

4 recordsLinked to original sources
PubMed1983

Delayed-type cutaneous hypersensitivity to Thomsen-Friedenreich (T) antigen in patients with pancreatic cancer.

The delayed-type hypersensitivity skin reaction to human erythrocyte-derived Thomsen-Friedenreich (T) antigen was studied in 40 patients with pancreatic disease and in 158 control subjects and its sensitivity and specificity were compared with the carcinoembryonic antigen (CEA) blood levels. The skin reaction to T was positive in 22 of 25 patients with biopsy-proven adenocarcinoma of the pancreas (sensitivity, 88%). In these patients, the CEA levels were elevated above 3.5 ng/ml in 12 of 23 (52%). The skin test to T antigen was negative in 11 of 12 patients with chronic pancreatitis (specificity, 92%), but CEA levels were normal in only five of nine with pancreatitis (56%). Two of the patients with pancreatic carcinoma and one of those with pancreatitis were anergic to mumps and dermatophytin antigens and had thus an invalid skin test. The positive response rate to T antigen was significantly greater (P less than 0.005) in the cancer group than the group with pancreatitis; the CEA response was not significantly different. There were no positive responses to T in 82 healthy volunteers. Among 76 patients with chronic disease including six with malignant tumors of the mesoderm and central nervous system, there were four positive responses: two in heavy smokers and two in patients with chronic lung infection. The specificity of the test overall in 158 controls was thus 97.5%.

Adenocarcinoma↗
PubMedDate not supplied

Effects of insecticide, diazinon, on pancreas of dog, cat and guinea pig.

The organophosphate insecticide Diazinon has been reported to cause acute pancreatitis in dogs. Based on histochemical examination of the acinar tissue, it was suggested that pancreatic tissue-fixed butyrylcholinesterase (BuChE) is the target enzyme of organophosphate toxicity. To further evaluate this theory, we exposed dogs, cats, and guinea pigs to a single sublethal dose of the organophosphate insecticide Diazinon (75 mg/kg). In cats, which lack pancreatic BuChE, no pathological changes occurred after two, three, and six hours, whereas in the guinea pigs as in dogs, both having abundant pancreatic BuChE, vacuolization of the acinar cells, interstitial edema and vasculitis indicate acute edematous pancreatitis as early as two hours. Atropine pretreatment (0.2 mg/kg) gave complete protection against pancreatitis. It was concluded that inhibition of pancreatic BuChe leads to cholinergic hyperstimulation of the acinar cell, which results in acute pancreatitis, and that pancreatic BuChE is essential for dogs and guinea pigs to downregulate cholinergic excitation. The insecticide pancreatitis model is considered a simple, non-invasive, reproducible, and cheap and useful method to evaluate early changes and methods of treatment in acute pancreatitis. Pancreatitis in humans has also been reported after accidental insecticide exposure.

Animals↗