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C J Uys

Publications and source records attributed to C J Uys.

At least 19 recordsLinked to original sources
PubMed1995

Reproducibility of a histogenetic classification of thymic epithelial tumours.

A histogenetic classification of thymic epithelial neoplasms proposed by Müller-Hermelink and co-workers has been shown by a number of recent studies to be of clinical and prognostic value. Reproducibility is an important criterion for the acceptance of any new classification for general diagnostic use. The reproducibility of this classification was tested on 51 cases of thymic epithelial neoplasia, by comparing results obtained by pathologists working from published criteria only with those results obtained by the pathologists who developed the classification. In 78% of cases there was complete concordance of results. Analysis of the 22% discordant cases showed that this discordance was due to a degree of subjectivity in determining cut-off points between categories adjacent to each other in the morphological spectrum of thymic epithelial neoplasia (medullary v. mixed, cortical v. well-differentiated thymic carcinoma). In terms of the important clinical distinction between benign (medullary and mixed) thymomas and those with more aggressive biological behaviour (cortical types and well-differentiated thymic carcinoma), the degree of reproducibility was 96%. The high degree of reproducibility of this histogenetic classification of thymic epithelial neoplasms should facilitate its acceptance and use in routine diagnostic pathology.

Adolescent↗
PubMed1989

Coronary artery plaque rapidly induced by local electromagnetic stimulation in the baboon.

A reliable method has been developed to produce stenosis of the right coronary artery of baboons as a consequence of electrostimulation of the vessel at a chosen position. At that site a pair of electrodes were implanted and activated with a train of 9-volt pulses (length: 10 ms, separation: 100 ms) for 30 min, 5 days/week, up to 6 weeks. 13 animals were included in the experiment, 2 of those served as controls. Pathohistologically the structure of the artificially produced constrictions is similar to atherosclerotic lesions. On average the stenoses occupied 55% of the available lumen; total occlusion and no stenosis were observed in 1 case each.

Animals↗
PubMed1986

Congenital hemangiopericytomas of skin.

A case of multiple congenital hemangiopericytomas of skin treated by surgical excision is presented. No recurrence of the lesions has occurred after a period of 2 years.

Antigens↗
PubMed1985

The significance of left ventricular volume measurement after heart transplantation using radionuclide techniques.

Multigated equilibrium blood pool scanning using Technetium 99m labeled red blood cells was used to measure left ventricular volumes in three heterotopic and one orthotopic heart transplant recipient(s). Simultaneously, an endomyocardial biopsy was performed and the degree of acute rejection was assessed by a histological scoring system. The scores were correlated to changes in ejection fraction and heart rate. Technetium 99m scanning data were pooled according to the endomyocardial biopsy score: no rejection; mild rejection; moderate rejection, and severe rejection. In each group, the median of the left ventricular volume parameters was calculated and correlated with the endomyocardial biopsy score, using a non-parametric one-way analysis of variance. A decrease in stroke volume correlated best with the endomyocardial biopsy score during acute rejection. A decrease in end-diastolic left ventricular volumes did not correlate as well. Changes in the end-systolic left ventricular volumes were not statistically significant, but using a simple correlation between end-systolic left ventricular volumes and endomyocardial biopsy the correlation reached significance. Changes in left ventricular volumes measured by Technetium 99m scanning may be useful to confirm the presence or absence of acute rejection in patients with heart grafts.

Adolescent↗
PubMed1984

Prediction of acute cardiac rejection using radionuclide techniques.

Radionuclide scanning of the donor left ventricle using technetium-99m-labelled red cells was used to monitor acute rejection after heterotopic heart transplantation and compared with histopathological evidence of rejection obtained at examination of an endomyocardial biopsy specimen. The ejection fraction and end-diastolic, end-systolic and stroke volumes were calculated at each examination; an equation was derived from these data to predict the degree of acute rejection, using histopathological examination of endomyocardial biopsy specimens as criteria of the presence and severity of rejection. A highly significant multiple correlation between radionuclide scanning parameters and endomyocardial biopsy was found. The advantages of non-invasive radionuclide scanning over the invasive procedure of endomyocardial biopsy are discussed.

Adolescent↗
PubMed1984

Pathologic findings in long-term cardiac transplants.

Since the introduction of cardiac transplantation at our institution 15 years ago, major advances have occurred in the monitoring and treatment of these patients, resulting in many long-term survivors. We defined the pathologic features in 14 cardiac transplants with survival times longer than one year. Only one heart showed no evidence of rejection, while the remaining 13 hearts showed advanced chronic rejection, which was the main cause of death or of graft failure in 11 patients. One patient died of gastric carcinoma, one of Kaposi's sarcoma, and one of cerebral embolus. The most obtrusive change in the donor hearts was an obliterative arteritis, which in the epicardial coronary arteries mimicked atherosclerosis. Superadded thrombosis often resulted in myocardial infarction. These severe vascular lesions bore no constant relationship to survival time and took from 1.1 to 12.5 years to evolve.

Adult↗
PubMed1983

Angiosarcoma of the superior vena cava.

The first reported case of an angiosarcoma apparently arising from the superior vena cava is presented. The patient, a 20-year-old white man, was treated by surgical excision and reconstruction with dacron grafts from the left and right brachiocephalic veins to the right atrium. This was followed by a course of mediastinal irradiation. The patient remained clinically disease-free at 24 months post-treatment. The patient had occasional occupational exposure to polyvinyl chloride.

Adult↗
PubMed1983

Infectious complications after heart transplantation.

Infection has been the major cause of death and morbidity in patients undergoing cardiac transplantation at Groote Schuur Hospital. Twenty-two (55%) patients suffered at least one major episode of infection, which accounted for 10 (59%) of the deaths in the first year. The major site of origin of infection was the lung, though dissemination was not infrequent. Bacteria accounted for 22 (59%) infections; but viral, fungal and protozoal infections were not uncommon and in fact accounted for seven (64%) of the fatal infections. Several unusual causative microorganisms have been isolated in this group of immunocompromised subjects. There is a higher incidence of infection in patients over the age of 35 years and in patients who did not comply with instructions and advice.

Adult↗
PubMed1983

Toxoplasmosis of donor and recipient hearts after heterotopic cardiac transplantation.

Toxoplasmosis of both donor and recipient hearts was diagnosed by means of endomyocardial biopsy specimens after heterotopic cardiac transplantation for dilated cardiomyopathy. Before transplantation, the donor had raised antibody titers to Toxoplasma, and the recipient was negative. When toxoplasmosis was diagnosed on the basis of endomyocardial biopsy specimen, the recipient had a greatly elevated antibody titer of 1:1,027. This suggests that the infection could have been transferred with the donor heart. The mononuclear cell response elicited by disrupted toxoplasmic cysts interferes with the diagnosis of rejection in graft biopsy specimens. Electron microscopy is valuable in confirming a light microscopic diagnosis of toxoplasmosis. Drug therapy eradicated the toxoplasmosis, but the patient died later of tuberculous meningitis.

Diagnosis, Differential↗
PubMed1982

Intra-osseous synovial sarcoma.

Intra-osseous synovial sarcoma is very rare and its mode of origin is conjectural. Our patient's tumour was situated within the lower femur. The sited of origin of the few intra-osseous synovial sarcomas so far documented may support the concept of intra-osseous synovial rests.

Adolescent↗
PubMed1982

Technique, complications, and clinical value of endomyocardial biopsy in patients with heterotopic heart transplants.

A review of 157 consecutive biopsies of donor endomyocardium in patients with heterotopic heart transplants is reported. The technique of percutaneous transvenous endomyocardial biopsy after this operation is described; manipulation of the catheter and bioptome into the junction of the donor superior vena cava and right atrium can be difficult when this anastomotic junction is small, as a result either of operative surgical technique or of subsequent contraction. The complication rate was 4%, but one patient may have died from infection resulting from biopsy when the bioptome had to be introduced at the groin. The histopathological changes seen in the biopsy specimens have been graded according to a scoring system to give the clinician a guide to the severity of rejection. Histopathological assessment was of clinical value in 96% of cases, but was inaccurate on two occasions, once because an opinion was given on what was in retrospect an inadequate sample. In patients undergoing persistent low-grade acute or chronic rejection there was difficulty in detecting or appreciating the true extent of myocardial fibrosis; this led to inadequate immunosuppressive treatment in two patients. Attention is drawn to the fact that ischaemic fibrosis resulting from the vascular changes of chronic rejection may spare the endomyocardium, which is kept viable by intracavitary blood, and that this may lead to a misleading histopathological report.

Biopsy↗
PubMed1980

Cholecystojejunocholecystostomy: a new method of biliary drainage in auxiliary liver allotransplantation.

A subhepatic, whole auxiliary liver allotransplant technique, previously developed in the pig, was assessed for technical feasibility in 26 human cadaver transplants. All technical aspects of the subhepatic technique were feasible, with the exception of donor to recipient gallbladder-to-gallbladder anastomosis, which could only be performed in 50% of subjects due to excessive separation of the two gallbladders. To oversome the problem, an original technique was developed--namely, the use of an isolated, vascularized, isoperistaltic loop of jejunum to act as a conduit between donor and recipient gallbladders (cholecystojejunocholecystostomy). Cholecystojejunocholecystostomy was subsequently developed and studied in a series of live porcine auxiliary allografts. The local, reginal, and general effects seen in 14 allografted pigs with cholecystojejunocholecystostomy were compared with those seen in a parallel and identical series of 14 allografts with cholecystocholecystostomy. The subhepatic transplantation technique is described in detail for the first time. Liver biopsies, blood samples, and clinical data were obtained at weekly intervals and at 28 days all survivors were killed. Cholecystojejunocholecystostomy proved to be a successful method of biliary drainage in the pig. Thirteen of the 14 interposed jejunal loops were viable and essentially normal at autopsy, leaks and naked eye stasis were infrequent, and the histological incidence of intrahepatic cholangitis and cholestasis minimal. The local, regional, and general effects were comparable in every way with those obtained with cholecystocholecystostomy.

Animals↗