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Biomedical subjects

J R Thornton

Publications and source records attributed to J R Thornton.

At least 19 recordsLinked to original sources
PubMed1992

Value of ultrasound and liver function tests in determining the need for endoscopic retrograde cholangiopancreatography in unexplained abdominal pain.

The value of serum liver function tests and abdominal ultrasound as screening tests of the need for endoscopic retrograde cholangiopancreatography (ERCP) was determined in patients with unexplained abdominal pain without associated jaundice. In 1989 and 1990 1005 ERCPs were undertaken, of which 138 (14%) were for this indication. The duct or ducts of interest were delineated by ERCP in 95% of patients. The lesions found were bile duct stones in 10 patients, chronic pancreatitis in five, pancreatic carcinoma in one, peptic ulcer or duodenitis in four. A satisfactory ultrasound examination had been performed in 94% of patients. For chronic pancreatitis, its sensitivity was 60% and specificity 95%. For choledocholithiasis, the ultrasonic detection of duct dilatation or stones had a sensitivity of 90% and specificity of 86%. Of the liver function tests, the alkaline phosphatase was more sensitive (67%) than the transaminases (44%) in indicating the presence of bile duct stones and had a high specificity (95%). None of the 10 patients with duct stones had normal ultrasound and normal alkaline phosphatase. Thus it was found that demonstration of a normal common bile duct by abdominal ultrasound and normal serum alkaline phosphatase together have 100% specificity in excluding bile duct stones. Using such knowledge over the two year period of this study would have spared 36 patients the need for ERCP.

Abdominal Pain↗
PubMed1992

Effects of exercise stress on various immune functions in horses.

Chemotactic locomotion and luminol-dependent chemiluminescence of neutrophils, mitogen-induced lymphocyte blastogenesis, serum cortisol concentration, immunoglobulin quantification, and leukocyte counts were determined to evaluate the effect of a single strenuous exercise in horses. Increased serum cortisol concentration (P less than 0.01) and an increased neutrophil-to-lymphocyte ratio (P less than 0.05) indicated that horses had been stressed. The chemotactic index and peak chemiluminescence production decreased significantly (P less than 0.05 and P less than 0.01, respectively) 1 day after exercise. Mitogen-induced blastogenesis of lymphocytes and serum immunoglobulin values remained unchanged in response to exercise. Results of this study indicated that a single bout of exercise may transiently impair neutrophil antimicrobial functions and nonspecific defense mechanisms, but not specific immunity in horses.

Animals↗
PubMed1991

Plasma beta endorphin in cirrhosis and renal failure.

Whether the plasma concentration of beta endorphin was increased in hepatic cirrhosis like that of smaller opioid peptides methionine enkephalin and leucine enkephalin was determined. Its concentration in chronic renal failure was also measured. Plasma beta endorphin was not significantly raised in cirrhotic patients with or without ascites (medians 5.2 pmol/l and 4.7 pmol/l respectively) compared with disease control subjects (4.9 pmol/l) and healthy control subjects (4.9 pmol/l). In contrast, the peptide was increased 2.5 fold (p less than 0.001) in chronic renal failure (12.4 pmol/l) and was found in many of these patients' urine. The data are compatible with the hypothesis that the liver may play an important role in the elimination of opioid peptides of octapeptide size or less but not the larger peptides such as beta endorphin.

Humans↗
PubMed1991

Septicaemia after colonoscopy in patients with cirrhosis.

Two patients with ulcerative colitis and chronic active hepatitis with cirrhosis, who developed Gram negative septicaemia after colonoscopy are described. These and two similar reported cases indicate that giving prophylactic antibiotics to patients with cirrhosis undergoing colonoscopy should be considered, particularly when the cirrhosis is advanced.

Adult↗
PubMed1990

Effect of strenuous exercise stress on chemiluminescence response of equine alveolar macrophages.

Bronchoalveolar lavage samples were collected using a fibreoptic endoscope from horses at specified times before and after single bouts of exercise. Lucigenin-dependent phagocytic chemiluminescence was used to assess the effect of exercise on the alveolar macrophage metabolic activity in response to stimulation by opsonised zymosan. A profound suppressive effect on the chemiluminescence production was present throughout the first three days after exercise. However, the cellular composition of lavage fluids was not altered by the exercise. It is suggested that strenuous exercise may jeopardize the antimicrobial function of alveolar macrophages which may lead to an increase in susceptibility to infection.

Animals↗
PubMed1989

Methionine enkephalin is increased in plasma in acute liver disease and is present in bile and urine.

Plasma immunoreactive methionine enkephalin is increased in cirrhosis. To determine whether it was increased in acute liver disease and chronic renal failure and whether the peptide was present in bile and urine, it was measured by radioimmunoassay in appropriate samples. Plasma immunoreactive methionine enkephalin, while at its peak in 15 patients with acute liver disease (median 425 pmol/l, range 220-1460), was approximately six times greater (P less than 0.001) than in 15 patients with chronic renal failure (70 pmol/l, 50-140), 15 controls with other diseases (75 pmol/l, 50-115) and 15 healthy controls (65 pmol/l, 50-95). In eight of the patients recovering from acute liver disease, the decline of the peptide's plasma level correlated with that of the alanine aminotransferase (r = 0.813, P less than 0.01) and prothrombin time (r = 0.682, P less than 0.05) measured in the simultaneously taken blood. Immunoreactive methionine enkephalin was found to be excreted in bile and urine. The possibility that increased plasma methionine enkephalin, and possibly other opioid peptides, may contribute to some of the manifestations of acute liver failure is worthy of further investigation.

Acute Disease↗
PubMed1989

Plasma leucine enkephalin is increased in liver disease.

Plasma methionine enkephalin is increased in liver disease and may contribute to some of the clinical manifestations of hepatic failure. To determine if another 'small' opioid peptide is increased in the plasma of patients with liver disease, leucine enkephalin was measured by radioimmunoassay. Its plasma concentration was raised approximately five-fold in patients with acute liver disease (median 1490 pmol/l, range 830-2420) and three-fold in patients with cirrhosis with ascites (960 pmol/l, 470-2900), compared with disease controls (325 pmol/l, 180-740) and healthy controls (305 pmol/l, 180-560). The increase in plasma leucine enkephalin was proportional to the degree of liver damage, as judged in the patients with acute liver disease by its correlation with the prothrombin time (r = 0.691, p less than 0.01) and alanine aminotransferase (r = 0.502, p less than 0.05), and in the patients with cirrhosis by its negative correlation with the plasma albumin (r = -0.743, p less than 0.001). It is unclear whether the raised plasma leucine enkephalin in liver disease is a consequence of diminished hepatic inactivation, increased secretion from sympathetic nerves and adrenal glands, or both.

Acute Disease↗
PubMed1989

Fatal variceal haemorrhage after paracetamol overdose.

A patient is described where oesophageal varices developed and bled 13 days after a paracetamol overdose. The bleeding was unresponsive to medical management and proved fatal. There was no evidence that the patient had pre-existing liver disease. At necropsy the liver showed severe acute parenchymal necrosis but chronic lesions were absent. The portal vein and hepatic veins were patent.

Acetaminophen↗
PubMed1989

Variceal bleeding is associated with reduced risk of severe cholestasis in primary biliary cirrhosis.

To test the hypothesis that, in primary biliary cirrhosis, bleeding from oesophageal varices implies a reduced risk that a patient will subsequently develop severe cholestasis, the case records of 76 patients with this condition who had died were examined. Fifty-nine patients (78 per cent) had died solely or largely as a consequence of liver disease. Their median survival from the onset of symptoms was 72 months. Most died from either hepatic failure with marked jaundice, infected ascites or variceal bleeding. Fifteen patients had a plasma bilirubin less than 100 mumol/l at the time of death. Twenty-eight patients had had variceal bleeding. Compared with the remaining 31 who had also died from cirrhosis, the patients who had bled from varices survived longer, were much less likely to die of hepatic failure and to become severely jaundiced but were more likely to develop fatal infected ascites.

Adult↗
PubMed1988

Opioid peptides and primary biliary cirrhosis.

Patients with liver disease have increased plasma concentrations of the endogenous opioid peptides methionine enkephalin and leucine enkephalin. As an initial investigation to determine whether opioid peptides contribute to any of the clinical manifestations of hepatic disease nalmefene, a specific opioid antagonist devoid of agonist activity, was given to 11 patients with cirrhosis. They all experienced a severe opioid withdrawal reaction on starting the drug. In the nine patients with primary biliary cirrhosis pruritus was greatly alleviated, fatigue seemed to improve, and plasma bilirubin concentration, which had been rising, showed a modest fall in all except one patient. These results indicate that blocking opioid receptors has an effect on some of the metabolic abnormalities of liver disease.

Adult↗
PubMed1988

Is ascites caused by impaired hepatic inactivation of blood borne endogenous opioid peptides?

Methionine enkephalin and catecholamines were measured in carefully collected plasma samples from 25 patients with cirrhosis and ascites, and 25 with cirrhosis without ascites, 15 disease and 15 healthy controls. Methionine enkephalin was invariably raised in the ascites group, the median value being 4.6-6.9 times that of the other three groups. Similarly, in the ascites group, median noradrenaline was increased 2.5-4.2 and median adrenaline 1.8-2.5 times that of the other groups. Plasma methionine enkephalin is considerably raised in patients with cirrhotic ascites and has actions which could enable it to be an initiating factor of ascites formation.

Ascites↗
PubMed1988

Do increased catecholamines and plasma methionine enkephalin in cirrhosis promote bleeding oesophageal varices?

Increased sympathetic tone and adrenal medullary activity in hepatic cirrhosis may promote portal hypertension. We suggest that they may be imperfect homeostatic mechanisms attempting to maintain systemic arterial pressure in response to chronic vasodilatation and that small, endogenous opioid peptides may play a part in this vasodilatation. As initial investigation of this hypothesis, we measured noradrenaline (an indicator of sympathetic tone), adrenaline and methionine enkephalin in the plasma of patients with cirrhosis with oesophageal varices which had or had not bled previously, patients with cirrhosis without varices, patients with acute liver disease and controls. In patients with cirrhosis, noradrenaline, adrenaline and methionine enkephalin were all greatest in those with oesophageal varices which had previously bled. In this group, noradrenaline correlated strongly with the widely used prognostic guide, Pugh's modification of Child's classification. In patients with acute liver disease, methionine enkephalin and adrenaline were increased six- and four-fold respectively. However, noradrenaline was normal, suggesting that increased sympathetic tone in cirrhosis may develop gradually. The use of opioid antagonists may enable determination of whether elevated plasma opioid peptides in cirrhosis stimulate the increase in sympathetic tone and plasma adrenaline, and promote bleeding oesophageal varices.

Acute Disease↗
PubMed1987

Super-efficient starch absorption. A risk factor for colonic neoplasia?

We tested the hypothesis that super-efficient starch absorption, by reducing the supply of carbohydrate to the colon, may be associated with and possibly promote colonic neoplasia. By means of breath hydrogen measurements following a potato meal and comparison with the hydrogen response to lactulose, the amount of starch escaping small bowel absorption was measured in 10 patients who had a colonic adenoma removed endoscopically and in 10 controls. The subjects' consumption of starch and fiber was assessed. Percentage unabsorbed starch was approximately half as much in the patients (5.3%) compared with the controls (10.9%, P less than 0.05). Consumption of starch and dietary fiber, and mouth-to-cecum transit times were not significantly different. Unabsorbed starch was calculated to contribute to 6.0 g/day colonic carbohydrate in the patients and 10.9 g/day in the controls (P less than 0.05). This study confirms that unabsorbed starch provides an important quantity of colonic carbohydrate and suggests that super-efficient starch absorption, by reducing this provision, may promote colonic neoplasia.

Breath Tests↗