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Biomedical subjects

L C John

Publications and source records attributed to L C John.

32 records · Page 2Linked to original sources
PubMed1992

Effect of heparin on in vitro platelet reactivity in cardiac surgical patients--a comparative assessment by whole blood platelet aggregometry and haemostatometry.

The in vitro effect of heparin on platelet reactivity was assessed simultaneously by haemostatometry (response to shear stress) and whole blood platelet aggregometry response to collagen (WBPA). From each blood sample a ratio (HR for haemostatometry and MR and IR for WBPA) showing platelet reactivity in the presence or absence of heparin (5 U/ml) was calculated. A value less than 1 represented a proaggregatory effect and greater than 1 an inhibitory effect. Non-anticoagulated blood samples obtained from 290 cardiac surgical patients were tested by haemostatometry and citrated whole blood samples from 100 patients with aggregometry. Haemostatometry demonstrated a proaggregatory effect of heparin in 8.6% (25) and an inhibitory effect in 91.4% (265). Assessed by WBPA, heparin was proaggregatory in 41-46% and inhibitory in 54-59%. In the 100 patients tested by both methods there was a significant correlation between the findings with the two techniques (r = 0.46, p less than 0.0001). A wide individual variation in the platelet effect of heparin was demonstrated. This variation appeared greater and a higher proportion showed inhibition when blood was tested by haemostatometry.

Blood Platelets↗
PubMed1992

Contamination of underwater seal drainage systems in thoracic surgery.

The incidence of bacteriological contamination of drainage fluid (water constituting the underwater seal plus drainage effluent) was studied in 38 patients (50 chest drains), up to 6 days after thoracotomy. No bacteriological contamination was demonstrated in any of the samples taken during this period of time. We conclude that the underwater seal drainage system may be left for up to 6 days postoperatively without change of any of its components and without risk of contamination.

Drainage↗
PubMed1991

Quantitative measure of small vessel anastomotic contour using corrosion resin cast models: an aid to surgical training.

A surgeon who had not previously carried out a small vessel anastomosis performed 20 consecutive anastomoses between human long saphenous vein and the left anterior descending artery of a pig's heart. Corrosion resin cast models were made of the anastomoses and subjected to a quantitative analysis of the anastomotic contour. A trend of improvement in contour parameters was found with increasing experience. This model may be useful for surgeons in training.

Animals↗
PubMed1991

Modified technique of internal mammary artery harvest.

A simple method of internal mammary artery harvesting is described. Hydrostatic pressure is used as an aid to dissection of the tissues including the internal mammary artery from the chest wall. The technique minimizes trauma to the mammary artery and allows for a rapid harvest.

Dissection↗
PubMed1991

The role of surgery in the management of solitary coronary artery aneurysm.

A 55-year-old lady presenting with angina was diagnosed on angiography as having a solitary aneurysm of a lateral circumflex artery. She underwent clipping of the aneurysm and a long saphenous vein bypass graft to the distal vessel. The role of surgery in the management of coronary aneurysms is discussed.

Angina Pectoris↗
PubMed1991

Bullet pulmonary embolus and the role of surgery.

A case report is described of a 33-years-old male who suffered a bullet pulmonary embolus following an abdominal gunshot injury. The literature of this rare occurrence is discussed together with the role of surgery in its treatment. Operative removal is advocated in all cases and the optimal time for removal is 1-2 weeks following the initial embolus to allow pulmonary induration, which can prevent peroperative embolus migration.

Abdominal Injuries↗
PubMed1991

Giant thymic carcinoid.

Thymic carcinoid is a rare tumour. It may present with ectopic endocrine secretion or with symptoms of compression as a result of its size. A case is reported which presented with symptoms of compression where the size of the tumour was uniquely large such as to warrant the term giant thymic carcinoid. The typical histological features are described, together with its possible origin and its likely prognosis.

Carcinoid Tumor↗
PubMedDate not supplied

Teratoma associated with endodermal sinus tumor.

A 3-1/2-year-old girl was diagnosed as having a mediastinal endodermal sinus tumor with pulmonary, bony, and hilar lymph node metastases. Following 7 months of treatment with chemotherapy, thoracic CT (computerized tomogram) scan showed the presence of a residual mass. Upon further surgical exploration the residual mass, which was found to be intrapericardial and arising from the ascending aorta, was resected. This second lesion was shown to be a benign cystic teratoma. The combination of an intrapericardial teratoma and a mediastinal endodermal sinus tumor in a female child is probably unique. The possible etiology for the combination of these two pathologies is discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Chronic traumatic aneurysm of the aorta: to resect or not. The role of exploration operation.

A case is reported of a chronic traumatic aneurysm of the aorta believed to be of 24 years duration in an asymptomatic 43 years old male. At operation the aneurysm was found to be fusiform, rigidly calcified and extending for approximately 8 cm beyond the left subclavian artery. In view of its extent and apparent rigidity of its walls resection and grafting did not proceed. The role of exploratory thoracotomy in the management of chronic traumatic aneurysms of the aorta is discussed.

Adult↗