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Biomedical subjects

D J Cannon

Publications and source records attributed to D J Cannon.

At least 37 records · Page 2Linked to original sources
PubMed1983

Serum proteolytic and antiproteolytic activity in acute pancreatitis.

This study has demonstrated an imbalance between the blood proteolytic and antiproteolytic system in acute pancreatitis. Serum elastase activity is markedly increased and elastase inhibitory capacity is decreased in this disease as compared with those in chronic pancreatitis and the control values. We have found that a return to normal values represents better evidence of resolution than amylase determinations. These results offer the clinician a biochemical guideline for the medical management of acute pancreatitis.

Acute Disease↗
PubMed1982

Blood elastolytic activity in patients with aortic aneurysm.

The question of why obstruction of the aorta (Leriche's syndrome) develops in some patients with severe atherosclerosis of the abdominal aorta while an abdominal aortic aneurysm occurs in others was examined. Significant differences in age, height, weight, mortality, and subsequent operative treatment were found between 335 patients with Leriche's syndrome and 103 patients with abdominal aortic aneurysm. Almost all in both groups smoked and demonstrated leukocytosis. In smokers with aneurysm, circulating serum elastolytic activity and leukocytic granular elastolytic activity were significantly increased, whereas serum antiproteolytic capacity was reduced. These results indicate that the development of abdominal aortic aneurysm in patients who smoke correlates with an abnormal homeostasis between proteolytic and antiproteolytic activity.

Adult↗
PubMed1981

Glycosylated haemoglobin levels in a colony of spontaneously diabetic rabbits.

Elevated glycosylated haemoglobin values have been observed in overtly diabetic animals from a colony of spontaneously diabetic rabbits. Chemically diabetic and normal animals did not show elevated levels. Overtly diabetic animals averaged 12.2% glycosylated haemoglobin versus 4.3% for chemically diabetic and 3.9% for normal animals. Increased levels did not correlate with plasma glucose concentration. Some chemically diabetic and normal animals progressed with time to a more severe diabetic classification. Glycosylated haemoglobin levels at the high end of the range of values for normal animals are predictive of this progression especially in certain litters.

Animals↗
PubMed1981

Metastatic emphysema: a mechanism for acquiring inguinal herniation.

Since our previous work had indicated that veterans with inguinal herniation demonstrated qualitative and quantitative changes in connective tissue, we tested the hypothesis that a possible mechanism for the defect was chronic exposure to circulating proteases generated in the lung by cigarette smoke. We investigated 59 men (average age: 60 years) with eigher primary direct of indirect hernias. Most of the patients smoked. Circulating serum elastolytic activity was significantly greater in patients with direct hernias who smoked when compared with controls (p less than 0.001). In addition, the serum alpha-1-antitrypsin inhibitory capacity was significantly lower in this category than controls (p less than 0.001). Patients with indirect defects who smoked also had significantly higher elastolytic values but to a lesser degree (p less than 0.01). Serum antiprotease and protein concentrations were within the normal range in all categories. Our results indicate that an imbalance between blood protease and antiproteases, resulting from chronic smoking can damage connective tissue in the groin as well as the lung.

Female↗
PubMed1978

Collagen crosslinking in keratoconus.

The examination of reducible collagen crosslinks in keratoconus cornea revealed the presence of lysinonorleucine in amounts far greater than in normal age-matched corneas. There was no indication of decreased hydroxylysine levels in keratoconus, and there were no clinical indications of a generalized connective tissue disorder. The abnormal levels of dehydrolysinonorleucine in the tissue may represent a change in hydroxylation of selected lysyl residues of normal collagen or the synthesis of abnormal collagen, perhaps an unusual type.

Adult↗
PubMed1977

Aging, and crosslinking in mammlian collagen.

The amount and type of borohydride-reducible crosslinks in collagen have been examined as a function of animal age. In a variety of bovine, canine and human tissues the level of redicible crosslinks decreases with time and the ratios of individual compounds change. There is both tissue and species specificity in the extent of these changes. A decrease in the level of reducible crosslinks correlates with the cessation of growth. Loss of reducible crosslinks does not imply a small total number of crosslinks since physical changes with age imply the opposite. We conclude that reducible crosslinks are converted to a stable nonreducible state and the persistence of low levels of reducible crosslinks may be indicative of a low level of turnover in the tissue. Changes in ratios of reducible crosslinks are of doubtful functioal significance and may simply reflect variation in post-translational modification of lysine residues.

Adolescent↗
PubMed1976

A stabilised tris(hydroxymethyl)aminomethane adduct in reduced collagen.

The reduction of collagen with sodium [3H] borohydride in the presence of Tris buffer results in the stabilization of a Schiff base adduct which is formed between allysine residues and tris(hydroxymethyl)aminomethane. The reduced, radioactive derivative of this adduct has been identified in hydrolyzates or reduced collagen. It elutes before hydroxylysine on an amino acid analyzer column close to the position of dihydroxylysinonorleucine. Similar artifacts may occur when aldehydes present in or added to proteins react with Tris or other amines prior to reduction.

Allyl Compounds↗