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Biomedical subjects

J Dale

Publications and source records attributed to J Dale.

At least 181 records · Page 10Linked to original sources
PubMed1978

Leukocyte function after aortic valve replacement.

Leukocyte function was studied in patients with prosthetic heart valves by oxygen consumption measurements during phagocytosis of polystyrene latex particles. The consumption reflects the phagocytotic capacity of the cells. In 38 patients with Starr-Edwards aortic ball valves the mean oxygen consumption was 3.95 nanoatoms per minute per 10(6) leukocytes, as compared to 4.15 in 50 healthy subjects, the difference not being statistically significant. The number of leukocytes per ml. of blood and the distribution of cell types was quite similar in the two groups, although slightly more younger cells were found in the patients. It is concluded that the capacity for phagocytosis is not significantly reduced after aortic ball valve implantation.

Aortic Valve↗
PubMed1978

Carcinoma of the breast with metaplasia to chondrosarcoma: a light and electron microscopic study.

Two carcinomas of the breast containing large areas of sarcomatous tissue were studied by light and electron microscopy. In one of these, the sarcomatous element was frankly cartilaginous and in the other, predominantly myxoid but with small cartilaginous-looking foci. By light microscopy, a highly suggestive metaplastic transition could be traced from cells within the epithelial nests to those within the sarcomatous lobules. Ultrastructurally, cells in the former region showed epithelial characteristics and those in the latter region, mesenchymal and/or cartilaginous features. The carcinomatous cells contained desmosomes and formed intercellular spaces lined by microvilli; a few cells showed prominent profiles of rough endoplasmic reticulum. In the first case, the cells in the immediate vicinity of the epithelial nests and those in the fully developed cartilaginous regions showed a progressive dilatation of their endoplasmic reticulum to form large sac-like structures filled with a finely granular and floccular material. The intercellular matrix was electron lucent and contained scattered dense particles, fibrillo-granular material and collagen fibres. Condensation of this material at some distance from the cell resulted in the formation of lacunae. In the second case, the cells in the myxoid areas also showed prominent dilatation of endoplasmic reticulum.

Breast Neoplasms↗
PubMed1978

Effects of slow intravenous administration of endotoxin on blood cells and coagulation in dogs.

Endotoxin shock was induced in dogs by slow administration of a lethal dose of Escherichia coli endotoxin. During the 3-hour infusion period a state of disseminated intravascular coagulation (DIC) was noted. The drop in platelets and leukocytes was the most rapid and pronounced effect of the infusion, while consumption of coagulation factors occurred more slowly. Activation of the extrinsic and intrinsic pathways of coagulation appeared to be closely parallel. Concomitantly increasing amounts of fibrin(ogen) degradation products were detected, while soluble fibrin monomers were observed only inconstantly. Intravascular hemolysis was slight and occurred in the late stages of shock, and could not have influenced the development of DIC.

Animals↗
PubMed1977

Arterial thromboembolic complications in patients with Björk-Shiley and Lillehei-Kaster aortic disc valve prostheses.

Arterial thromboembolic complications were studied in 196 patients who had either a single Björk-Shiley or Lillehei-Kaster aortic disc valve implanted. Eight patients suffered from such complications in the course of the first postoperative month and three of them died, two from myocardial infarction and one from cerebral embolism. Nineteen late thromboembolic complications developed in 18 of the 164 patients who survived the postoperative period, the incidence bein 5.9 episodes per 100 patients per year. The two valve types wer found to be equallly thrombogenic, and the rate was not lower than that in patients with Starr-Edwards aortic ball valves of series 2,300 previously studied. Particularly serious was valve malfunction caused by thrombi that limited the movement of the discs. Early recognition of this condition is essential, because the only effective therapy is removal of the thrombus. Three patients with a Björk-Shiley and one with a Lillehei-Kaster valve suffered this complecation and two died, while cerebral embolism caused a third late death. Two of the three patients who had not received anticoagulants developed thromboembolic complications, while most episodes occurred in spite of well-maintained anti-coagulant treatment. It is concluded that arterial thromboembolic complications remain a considerable problem also after aortic disc valve implantation, and that thrombotic valve malfunction is particularly serious and requires special attention.

Adolescent↗
PubMed1977

Prevention of arterial thromboembolism with acetylsalicylic acid. A controlled clinical study in patients with aortic ball valves.

Prevention of arterial thromboembolism with acetylsalicylic acid (ASA) was studied in 148 patients with single Starr-Edwards aortic ball-valve prostheses. These patients are suitable for such a study because they have a high incidence of arterial emboli derived mainly from thrombi formed on the valves. They were given either 1 Gm. of ASA daily or placebo in combination with anticoagulants, and were observed for 2 years. Only two emboli occurred in patients receiving ASA, none of them severe. In the placebo group 12 thromboembolic episodes were diagnosed in 10 patients, and three with cerebral emboli died; in one a subdural hematoma unrelated to the embolus was found. In addition, one fatal and the one nonfatal intracranial bleeding occurred in each group, whereas gastrointestinal complications were seen more frequently in patients taking ASA. It is concluded that ASA combined with anticoagulants offered a significantly better protection against arterial thromboembolism than did anticoagulant therapy alone.

Adult↗
PubMed1977

Platelet functions in patients with aortic ball valves.

Platelet functions were studied in normal subjects and patients with single Staff-Edwards aortic ball valves of series 1200 and 2300. The most pronounced changes were found in platelet adhesiveness, measured with Hellem's modified method. The mean percentage of adhesive platelets was reduced from 71.8 in normal subjects to 50.9 in patients with valve type 1200 and to 27.2 in those with type 2300. An inverse correlation was found between platelet adhesiveness and the degree of intravascular hemolysis, as reflected by serum LDH levels. The mean bleeding time was significantly prolonged in patients with valve 2300, and the individual values correlated inversely to the adhesiveness. The mean values of platelet counts, or irreversible aggregation induced by collagen or epinephrine, and of platelet survival were all moderately-but significantly-reduced as compared to normal. The most important mechanism behind the disturbed platelet reactivity is probably mechanical damage of the platelets by the valve, whereas refractoriness of platelets toward ADP liberated from red cells as well as consumption of adhesive platelets by thrombus formation is thought to have limited influence on platelet behavior. Platelet function was altered to the same extent in patients with a history of arterial thromboembolic complications as in those without. The disturbed platelet reactivity may predispose to bleeding, but may also offer some protection against arterial thromboembolism.

Aortic Valve↗
PubMed1976

Arterial thromboembolic complications in patients with Starr-Edwards aortic ball valve prostheses.

Aterial thromboembolic complications were studied in 253 patients who had a single aortic Starr-Edwards ball valve implanted. During the first postoperative month, six patients died from myocardial infarction, one was reoperated because of leakage caused by thrombus on the valve, and five others suffered six thromboembolic episodes. Forty-six late thromboembolic complications occurred in 40 of the 216 patients who survived the postoperative period. Seven died, four from cerebral emboli and three from myocardial infarction. The late incidence was 7 episodes per 100 patients per year. Valves of series 1200 carried a significantly higher risk of arterial thromboembolism than did those of series 2300, and most episodes occurred in patients with cell controlled anticoagulant treatment. The incidence was not influenced by time since operation, continuous arrhythmia, concomitant mitral valve disease, heart size, or the degree of intravascular hemolysis. It is concluded that arterial thromboembolic complications represent a major threat to patients with aortic ball valves even several years after operation and in spite of intense anticoagulant therapy.

Aortic Valve↗
PubMed1975

Effects of dipyridamole and acetylsalicylic acid on platelet functions in patients with aortic ball-valve prostheses.

The effects of dipyridamole and ASA on platelet functions were studied in patients with aortic ball-valve prostheses. Before ingestion, platelet adhesiveness was markedly reduced and platelet survival time slightly, but insignificantly shortened. ASA prolonged the bleeding time, reduced collagen-induced platelet aggregation, and inhibited secondary aggregation initiated by adrenalin. Similar effects were obtained with 2 Gm. of ASA alone as with 1 Gm. daily in combination with 225 mg. of dipyridamole. Platelet adhesiveness remained low. Depyridamole alone, 375 mg. daily, did not influence any of these parameters. The mean platelet half-life was prolonged from 3.52 to 3.72 days by each drug and to 4 days by the combined treatment. None of the differences was, however, statistically significant. A clinical study with ASA has been started in a larger series of patients to evaluate the effect on arterial thromboembolism.

Aortic Valve↗
PubMed1975

[Echocardiographic abnormalities in the mitral valve prolapse syndrome].

Eight patients with prolapsed mitral valve syndrome, with a mid - or - end - diastolic click or murmur, underwent echocardiographic examination using ultrasound. Examination of the displacement of the valves by the "time motion" method showed all cases to have an abnormal recoil; in 6 cases this occurred in mid or late systole, and in two from the beginning of systole. The recorded amplitude of the pathological displacement, which gives the systolic tracings a domed appearance, and the consistancy with which it could be recorded (irrespective of the incidence of the ultrasonic waves), seem to afford a method for evaluating the degree of prolapse which, in most cases, involves both the valves. The authors compare their results with those which have already appeared in the literature, and emphasise the very real contribution which echocardiography can make in the diagnosis and assessment of the prolapsed mitral valve syndrome.

Adolescent↗