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Biomedical subjects

M Pillay

Publications and source records attributed to M Pillay.

At least 37 records · Page 2Linked to original sources
PubMed1997

99mTc-SPECT in the diagnosis of skull base metastasis.

OBJECTIVE: To evaluate the role of bone SPECT in diagnosing metastasis to the skull base in cancer patients. BACKGROUND: Skull base metastasis often causes characteristic clinical syndromes. Antitumor treatment ameliorates or stabilizes symptoms in most patients. Diagnosis may be difficult when neuroimaging studies are negative (as occurs in about one-quarter of patients). Case reports have suggested a role for bone SPECT in these patients. METHODS: We reviewed the charts of all patients (1993-1996) at our institution who had skull base SPECT and at least one neuroimaging study (CT or MRI) for clinically suspected metastasis to the base of the skull. Bone SPECT, CT, and MRI were blindly re-evaluated. RESULTS: We studied 56 patients, of whom 36 had skull base metastasis. Twenty patients had other causes of the clinical syndrome, including leptomeningeal and posterior fossa metastasis, or benign causes. In 29 of 36 patients (81%) with skull base metastasis, CT or MRI clearly demonstrated the lesion. Bone SPECT identified a hot spot in the appropriate region of the skull base in 28 of 36 patients (78%). All seven patients with negative CT or MRI had positive SPECT and four of these had a response to anti-tumor treatment. CONCLUSIONS: SPECT of the skull base can demonstrate lesions not identifiable by CT or MRI. In cancer patients suspected of having skull base metastasis, we recommend SPECT of the skull base when CT or MRI studies are negative.

Adult↗
PubMed1997

The curriculum of practice: a conceptual framework for speech-language therapy and audiology practice with a black African first language clientele.

This paper discusses the use of a conceptual framework (i.e., the curriculum of practice) to guide the transformation of professional practice toward equitable service provision, rooted in a research finding that South African Speech-Language Therapy & Audiology has a favourable service bias toward White English/Afrikaans first language speakers (Pillay, 1997b). Three perspectives of practice are discussed, i.e., the official, espoused and actual perspectives. Also, the various elements of practice are reviewed, and include clinical practice activities, resources and their utilization, professional education curricular and professional policies. It is asserted that re-constructing the profession's knowledge base in a presently (1996-) transforming South Africa, mostly requires the use of a critical (versus, for e.g., a scientific) paradigm.

Attitude of Health Personnel↗
PubMed1996

Tc-99m tetrofosmin myocardial distribution 4 hours post injection.

The recommended protocol for Tc99m tetrofosmin myocardial imaging suggests either a one- or two day imaging protocol so that stress and rest studies are sufficiently separated in time to allow optimum myocardium to background uptake ratios to differentiate between myocardial ischaemia and/or infarction. The biokinetic data for tetrofosmin suggest that no significant changes occur in myocardial distribution up to 180 minutes post injection. It is, therefore, necessary for two doses of the radiopharmaceutical and two separate studies to evaluate the myocardial status during stress and rest. This study assessed the differences between the 1 and 4 hour post injection SPET images obtained following peak exercise in 20 consecutively chosen patients. In addition, these images were compared to the rest images obtained on the following day after a second dose of the radiopharmaceutical was administered. In 4 patients, a one and four hour post injection study was also done during the rest phase. The results demonstrate significant changes in Tc-99m tetrofosmin distribution between the one hour and four hour post injection images. These differences are present during the stress as well as rest studies.

Aged↗
PubMed1996

IL-6-induced anaemia in rats: possible pathogenetic implications for anemia observed in chronic inflammations.

Anaemia of chronic disease (ACD) is frequently found in rheumatoid arthritis (RA). In the pathogenesis of ACD both cytokines, such as tumour necrosis factor-alpha (TNF-alpha), IL-1 and IL-6 as well as a relative deficiency of erythropoietin (EPO), are thought to play a key role. In the present study the role of IL-6 in the pathogenesis of this anaemia was investigated. IL-6 was administered intraperitoneally to rats for 14 sequential days. It appeared that IL-6 was able to induce anaemia. No evidence for suppression of bone marrow erythropoiesis or enhanced sequestration of erythrocytes in the liver was found. However, decreased plasma and bone marrow iron contents were observed in anaemic rats. Blood loss in intestinal tissue was demonstrated using erythrocyte labelling with 99mtechnetium. Histologically this was associated with inflammatory cell infiltration, oedema and bleeding in the intestinal wall. In conclusion, IL-6 induced anaemia in rats. This anaemia was caused by intestinal blood loss.

Anemia↗
PubMed1994

Effects of L-propionylcarnitine on ischemia-induced myocardial dysfunction in men with angina pectoris.

To identify the effect of L-propionylcarnitine (LPC) on ischemia, 31 fasting, untreated male patients with left coronary artery disease were studied during 2 identical pacing stress tests 45 minutes before (atrial pacing test I [APST I]) and 15 minutes after (APST II) administration of 15 mg/kg of LPC or placebo. Hemodynamic, metabolic, and nuclear angiographic variables were studied before, during, and for 10 minutes after pacing. After LPC administration, arterial total carnitine levels increased from 47 +/- 1.7 mumol/liter (control) to 730 +/- 30 mumol/liter. Hemodynamic and metabolic variables were comparable in LPC and placebo during APSI I, and reproducible in placebo during both tests. Although LPC did not affect myocardial oxygen demand and supply, it diminished myocardial ischemia, indicated by a significant 12% and 50% reduction in ST-segment depression and left ventricular end-diastolic pressure, respectively, during APST II. Moreover, during APST II, left ventricular ejection fraction increased by 18% (p < 0.05 vs APST I). Furthermore, LPC improved recovery of myocardial function after pacing, with a reduction in the time to peak filling and a 21% increase in both peak ejection and filling rates 10 minutes after pacing (all p < 0.05). Thus, LPC prevents ischemia-induced ventricular dysfunction, not by affecting the myocardial oxygen supply-demand ratio but as a result of its intrinsic metabolic actions, increasing pyruvate dehydrogenase activity and flux through the citric acid cycle. Because it is well tolerated, it may be a valuable alternative or addition to available antiischemic therapy.

Aged↗
PubMed1993

The diagnostic value of salivary gland scintigraphy in patients suspected of primary Sjögren's syndrome.

The diagnostic value of salivary gland scintigraphy in patients suspected of having primary Sjögren's syndrome (SS) was studied in 149 consecutive patients who presented with joint and/or muscle complaints in combination with dryness of the mouth and/or eyes and in 20 control subjects. The diagnosis primary SS could be established in 26 of these patients. Salivary gland scintigraphy scored by means of analogue pictures was abnormal in 19 out of 26 patients with primary SS but abnormal scintigrams were also found in 57 of the 123 patients without primary SS and in five of the controls. This resulted in a positive predictive value of an abnormal salivary gland scintigram of 25% and a negative predictive value of a normal investigation of 90%. From the high number of false positive test results in the patient population studied it is concluded that salivary gland scintigraphy has only a limited discriminatory value for the diagnosis of primary SS.

Adult↗
PubMed1992

A quantitative index derived from 99mTc-pertechnetate scintigraphy to assist in the diagnosis of primary Sjögren's syndrome.

A safe and simple technique is reported by which primary Sjögren's syndrome can be detected with a relatively high specificity and sensitivity. The method of serial scintigraphy has been used with reasonable success; however, the application of the linearity index as described here produced superior results. In 71 patients investigated, a sensitivity of 87% and specificity of 93% were recorded and make this the method of choice for evaluating patients suspected of having primary Sjögren's syndrome.

Humans↗
PubMed1992

Acute improvement of cardiac function with intravenous L-propionylcarnitine in humans.

As the myocardial carnitine content, a key control factor in myocardial oxidative metabolism and energy transfer, is reduced in heart failure, administration of L-propionylcarnitine (LPC), a potent analogue of L-carnitine, potentially may improve cardiac function, possibly through a positive inotropic effect. As its hemodynamic profile is unknown in humans, 32 fasting normotensive patients with coronary artery disease received either 15 mg/kg of LPC (n = 16) or vehicle (mannitol/acetate, n = 16) infused over 5 min. Hemodynamic, radionuclide [peak ejection and filling rates (PER and PFR, respectively)], and metabolic variables (myocardial O2, lactate, and carnitine uptake) were studied at baseline and 1, 3, 5, 10, 15, and 45 min postdrug. The baseline ejection fraction was depressed in LPC patients (40 +/- 3% vs. 48 +/- 4% in the vehicle group, p less than 0.05) as a result of a significant high incidence of previous infarctions. Immediately following LPC, the cardiac total carnitine uptake changed from 102 +/- 181 to 5,335 +/- 1,761 mumol/L (p less than 0.05). In both groups, left ventricular systolic and end-diastolic pressures increased significantly by 5 and 20%, respectively, during the first 5 min. In the vehicle group, contractility decreased by 5%, accompanied by a significant 11% fall in the stroke volume. In contrast, following LPC, isovolumetric contractility indices remained unaltered. Instead, both the PER and PFR improved by 16% at 45 min. Moreover, the cardiac output increased by 8%. LPC did not affect systemic or coronary hemodynamics. Lactate uptake increased by 42%, but myocardial O2 consumption did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Radioimmunodetection in rhabdo- and leiomyosarcoma with 111In-anti-myosin monoclonal antibody complex.

In patients with rhabdo- and leiomyosarcoma a radioimmunodiagnostic study was performed with 111In labeled F(ab) fragments of a monoclonal antibody against myosin. Eight patients with rhabdomyosarcoma and 18 patients with leiomyosarcoma were studied. Scanning was performed at 4, 24, and 48 h after administration of 74 MBeq of the antibody complex. A high uptake with a tumor:background ratio of 10:1 was observed in several patients with rhabdomyosarcoma but the results were less accurate in leiomyosarcoma.

Adolescent↗
PubMed1990

Uterine radiation dose from open sources: the potential for underestimation.

The evaluation of the risk of radiation damage to the unborn child as the result of the administration of radionuclides remains a subject for discussion (Mountford 1989). Lack of information concerning the biodistribution of radiopharmaceuticals in the early stages of pregnancy, before organogenesis has occurred, has greatly restricted the objective assessment of fetal doses. Recent observations on the biodistribution of a therapeutic dose of sodium iodide 131 in a patient with an unsuspected early pregnancy lead us to suspect that current dose estimates with respect to uterine exposure (ARSAC 1988) may seriously underestimate the actual exposure of the developing fetus.

Abnormalities, Radiation-Induced↗
PubMed1988

Indium 111 antimyosin for the detection of leiomyosarcoma and rhabdomyosarcoma.

111In-antimyosin monoclonal antibody complex passes through damaged myocardial cell membranes and binds to the intracellular myosin. Normal myocardial and other muscle cells show no uptake. Rhabdomyosarcoma and Leiomyosarcoma cells also contain intracellular myosin and the cell membrane permeability is greater than normal. Significant uptake of 111In-antimyosin was observed in patients with Leiomyosarcoma and Rhabdomyosarcoma suggesting that the reagent has a potential for the in vivo detection of these tumour types. Tumour to background ratios of 10:1 were measured in one case and in view of the fact that the site of accumulation is intracellular, antimyosin may have a potential as a carrier for therapeutic agents.

Adult↗
PubMed1988

The stability of 99mTc-DTPA and 99mTc-HIDA following ultrasonic nebulisation.

The stability of 99mTc-DTPA (diethylenetriamine-pentaacetic acid) and 99mTc-HIDA (2,6-diethylacetanilido-iminodiacetic acid) were evaluated following ultrasonic nebulisation. The results confirm that either of these radiopharmaceuticals can be used in our nebuliser without significant radiochemical breakdown.

Drug Stability↗
PubMed1988

Complement (C3) metabolism in rheumatoid arthritis in relation to the disease course.

Metabolic turnover studies of the third component of complement, C3, were performed in 23 patients with rheumatoid arthritis (RA) to get a direct insight in the dynamics of complement synthesis and catabolism. Results of these turnover studies were related to the serum level of the total amount of C3 as well as to that of the activation product C3d. A hypercatabolism of C3 was observed in 12 of the 23 patients studied. Six of these 12 patients showed signs of extra-articular RA; only one patient with extra-articular manifestations had a normal catabolism of C3. Decreased serum levels of C3 were not found in any of the patients with a hypercatabolism of C3, indicating that the accelerated turnover was compensated by an increased synthesis. In RA patients levels of the activation product C3d could not correlate with the turnover of C3. However, in selected RA patients without signs of nodules or extra-articular manifestations, they could. Thus, our results indicate that serum levels of C3 and C3d do not reflect C3 metabolism in RA patients. Furthermore, the existence of extra-articular manifestations is accompanied by a more pronounced activation of the complement system.

Arthritis, Rheumatoid↗
PubMed1987

A high efficiency ultrasound nebuliser for radioaerosol studies of the lungs.

An ultrasound nebuliser with variable delivery temperature and nebulisation volume was tested for particle size distribution, efficiency, and application in a clinical environment. The results obtained comply with our criteria for a general purpose radioaerosol generating system for use in evaluating various parameters of lung function.

Humans↗