A gold-nickel master alloy was prepared by arc melting in an inert atmosphere and from it, mechanical test specimens and dental prostheses were made by centrifugal casting. The cast alloy had a yield strength of about 7,400 kg/cm2, with an elongation of 12%. The alloy was clinically tested in the form of partial dentures and crown and bridge materials. For the 32-month period these prostheses have been in use, no tissue reaction, tarnish, or corrosion had been observed.

Crowns↗

PubMedDate not supplied

Endothelins and their receptors in cirrhotic and neoplastic livers of Canadian and Chinese populations.

BACKGROUND: Endothelins (ETs) are 21 amino acid peptides with widespread tissue distribution and functions. In this study, we retrospectively investigated immunoreactive ET-1, ET-3 as well as ET receptors by ligand binding and autoradiography in hepatic cirrhosis and neoplasms. MATERIALS AND METHODS: Formalin fixed paraffin embedded tissues from 30 hepatocellular carcinomas (HCC), 4 fibrolamellar carcinomas (FLC), and 7 liver metastatic adenocarcinomas (Ad) from colon were collected from the Pathology Department of London Health Science Centre. Adjacent cirrhotic livers were obtained from 17 cases and adjacent normal liver was present in 12 cases. In addition, 15 HCCs, 6 cirrhotic and 8 normal livers were obtained from Normal Bethune University for Medical Sciences in China. The slides were stained for ET-1 and ET-3 with a polyclonal antibody and scored. Autoradiographic localization of ET-receptors with 125I-ET-1 was carried out in some of the cases. RESULTS: In the normal liver, hepatocytes, biliary epithelium, vascular endothelium and smooth muscle cells were positive for both ET-1 and ET-3. Higher immnunoreactivity for ET-1 and ET-3 was seen in cirrhosis. HCCs showed variation in immunoreactivity, with overall scoring not different from normal livers. FLCs showed consistent higher immunoreactivity for both ET-1 and ET-3, while in Ads the immunoreactivity was decreased. Increased ET-receptors, representing both ETA and ETB subtypes were seen in both cirrhosis and in HCC. CONCLUSION: Alterations in both ETs and their receptors were found in cirrhosis and neoplastic liver diseases.

Adenocarcinoma↗

PubMedDate not supplied

Coronary artery reoperations using arterial conduits: immediate and early results.

This study deals with results of coronary artery reoperations in 21 males aged 54.4 +/- 6.6 years. Native vessel coronary disease at first and second operation was nearly the same (2.7 +/- 0.6 vs 2.8 +/- 0.4 vessel, p = NS). Graft attrition and deterioration in left ventricular ejection fraction (55.9 +/- 9.2 initial vs 36 +/- 15 at reoperation, p < 0.001) necessitated reoperation in majority. Recurrence of angina (71%) and left ventricular failure (23.8%) were the clinical indicators for reoperation. Procedure was successful in 20 (95%) and had to be abandoned in 1 due to severe pericardial and sternal adhesions. Arterial grafts were utilised in 90% (18 cases, Group A and B). Total arterial revascularisation (Group A) was done in 9 (45%) using Y graft 6, combination of both mammary arteries 2, and by both mammary and inferior epigastric artery in 1. Group B patients had arterial grafts (bilateral IMA 1, Y graft 1, bilateral IMA + gastroepipolic 1, RIMA 4, and LIMA 2) in addition to a venous graft. Two patients (group C, 10%) had only venous grafts. There was no in hospital mortality or morbidity and at 10 +/- 5.2 months follow up, all are asymptomatic with negative stress test at 3 months followup in 8 cases. We conclude that coronary artery reoperations using arterial conduits can be performed safely with excellent immediate and early results.

Angina Pectoris↗

PubMedDate not supplied

Alteration in pulmonary mechanics after coronary artery bypass surgery: comparison using internal mammary artery and saphenous vein grafts.

Pulmonary function tests, arterial blood gas tensions and morbidity were compared in 50 patients undergoing coronary artery bypass graft surgery. Thirty patients had bilateral internal mammary grafts (Group 1), 5 patients had only saphenous vein grafts (Group 2) and 15 patients had a single arterial graft in addition to vein grafts (Group 3). Pleural effusion and wound infection were more common in patients with internal mammary artery grafts (p < 0.05). Patients in Group 2 required prolonged ventilation but this could be related to their underlying left ventricular dysfunction. Patients in all the three groups developed a severe restrictive ventilatory defect in the postoperative period and the degree of impairment was maximum in Group 1 patients (p < 0.01). These patients also had evidence of small airway obstruction. Thus an overall decrease in pulmonary function occurs in the postoperative period by 30 to 40% (p < 0.001). The derangement is greater in patients with arterial grafts, as a result of impaired blood supply, increase in pleural drains and additional surgical trauma secondary to mobilization of internal mammary arteries leading to delayed recovery. The awareness of these findings can be of great value in postoperative management of these patients. In addition, these observations should also be kept in mind while planning the choice of grafts in a patient undergoing coronary artery bypass graft surgery.

Case-Control Studies↗