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H J Testa

Publications and source records attributed to H J Testa.

At least 37 records · Page 2Linked to original sources
PubMed1994

Interrelationship between serum concentrations of 1,25-dihydroxyvitamin D, parathyroid hormone and renal haemodynamics after low dose cyclosporin.

It is unclear whether cyclosporin A (CsA) alters the synthesis of 1,25-dihydroxyvitamin D3 [1,25(OH)2D] by the normal human kidney. Serial changes in 1,25(OH)2D, parathyroid hormone (PTH), GFR and renal blood flow were compared in 14 patients with psoriasis who were being treated with less than 5 mg/kg/day of cyclosporin for 3 months. GFR fell significantly although there were no significant changes in serum 1,25(OH)2D, 25-hydroxyvitamin D or PTH. Absolute values for GFR and PTH were negatively correlated (rP = -0.54; p < 0.001) as were the changes in GFR and PTH observed during CsA therapy (rP = -0.73; p < 0.05). The significant fall in serum magnesium was not significantly correlated with changes in PTH. The close relationship between changes in GFR and PTH suggests that a reduction of GFR within the normal range is enough to stimulate production of PTH. CsA does not appear to stimulate the synthesis of 1,25(OH)2D3 in man.

Adolescent↗
PubMed1994

Angiotensin II as a risk factor for cyclosporin nephrotoxicity in patients with psoriasis.

Abnormalities of the renin-angiotensin system after low-dose cyclosporin (5 mg/kg/day or less) have not been adequately defined in patients with normal kidneys. 27 patients with psoriasis were assessed before starting cyclosporin, after three months of cyclosporin (5 mg/kg/day or less) and then finally three months after finishing cyclosporin. On each occasion plasma renin activity (PRA), aldosterone, angiotensin II and atrial natriuretic peptide (ANP) were measured together with total renal blood flow (RBF), GFR and filtration fraction (FF) following an i.v. bolus injection of Tc-99m DTPA. Significant renal hemodynamic toxicity was defined as > 25% fall in RBF or > 20% fall in GFR. Using these criteria we identified 12 patients with hemodynamic toxicity (Group A) and 15 patients whose GFR and RBF did not fall significantly (Group B). In Group A a significant fall in GFR (p < 0.001) and reduction in renal blood flow (p < 0.04) were associated with significant rises in both ambulant and recumbent angiotensin II (p < 0.0005). PRA, aldosterone and ANP did not significantly alter. GFR partially recovered after withdrawal of cyclosporin although RBF remained significantly lower compared to initial values. In Group B there was no significant change in GFR or RBF although there was a reversible fall in FF (p < 0.02). There were no significant differences in angiotensin II, PRA, aldosterone or ANP. Circulating angiotensin II rises in patients who develop cyclosporin nephrotoxicity and may be responsible for mediating the hemodynamic effects.

Adult↗
PubMed1993

Validation of a non-invasive radioisotope method of imaging ureteric urine transport.

Measurement of ureteric function has hitherto involved the use of invasive techniques. A non-invasive, radioisotope method of imaging and displaying individual ureteric boluses has been described, a refinement of which is used in this department. Each "spindle" displayed using this technique theoretically represents an individual ureteric bolus of urine, but the technique has never been validated in the normal ureter in either the experimental model or man. A porcine model was set up to allow simultaneous measurement of ureteric bolus transmission using the radioisotope (compressed image) method and by the accepted techniques of electromyography (EMG) and urine drop counting. The timing of each urinary bolus, as recorded by the different modalities was then compared. The results from 11 studies showed a significant correlation between the radioisotope and EMG methods (mean r = 1.00, P = 0.0003). There was a constant relationship between the part of the radioisotopic image representing the rear end of the bolus and the EMG complex (mean time difference = 5.32 +/- 1.067s), thus defining that part of the image representing the peristaltic contraction wave. There was a variable relationship between the EMG and the part of the image representing the leading edge of the bolus (mean time difference = 13.36 +/- 5.23s), emphasising that bolus length is variable, being dependent on bolus volume. The radioisotope "spindle" concurs with EMG activity in the porcine ureter. The compressed image technique is thus validated as a non-invasive method of demonstrating ureteric urine transport.

Animals↗
PubMed1993

Non-invasive investigation of normal individual ureteric activity in man.

This study was designed to investigate non-invasively human ureteric function between individuals and with increasing diuresis, using the radioisotope compressed image technique. Five normal males underwent fast frame renography with ureteric spindle imaging in dehydrated and hydrated states, urine production being measured in each individual for each scan. Urine flow rates and renographic parameters demonstrated that each ureter carried more urine in the hydrated state. The velocity at which individual boluses passed down the ureter was constant for each ureter and did not change with diuresis. The ureteric peristaltic rate showed wide individual variation between ureters in the same subject, but fell within what is becoming accepted as the "normal range" of < 4 urine boluses per minute. Some ureters accommodated an increase in urine flow by an increased peristaltic frequency, some showed no change and others showed a decreased frequency. In those ureters in which there was no change, or a decrease in peristaltic frequency with diuresis, the increased urine flow must have been handled by increases in bolus volume. Thus increases in ureteric urine flow in man are accommodated by changes in both peristaltic frequency and bolus size. The results are discussed in relation to previous studies which used invasive techniques.

Adult↗
PubMed1993

Modulation of abnormalities in renal haemodynamics and vasoactive mediators by nifedipine in patients with psoriasis on low-dose cyclosporin.

Ten patients with psoriasis received a 3-month course of cyclosporin (2.5 mg/kg/day) followed by a 3-month washout period, before commencing a 3-month course of cyclosporin and nifedipine SR 20 mg b.d. Serial haemodynamic and biochemical measurements were performed before, during, and after treatment. Total renal blood flow (RBF) was measured following an intravenous injection of [99mTc]-DTPA based on a renographic analysis of the first-pass effect in the kidneys, and GFR was estimated from the subsequent clearance of this radiotracer. A significant individual change in RBF or GFR was taken as 25% and 20% respectively. Simultaneous assays of the circulating vasoactive mediators renin, aldosterone, angiotensin II, and atrial natriuretic peptide were performed. Two patients withdrew from the study because they could not tolerate nifedipine, leaving eight for complete analysis. The significant reductions in RBF and GFR which occurred on cyclosporin alone (P < 0.05; ANOVA) did not occur with added nifedipine. Four months after this second course, RBF and GFR had recovered. The response to nifedipine was, however, variable and unpredictable. Of the four patients to show a significant decline in GFR on cyclosporin alone, only two showed a significant improvement on the combined therapy. Of the six patients who showed a significant decline in RBF on cyclosporin alone, only four showed benefit from the added nifedipine. Nifedipine suppresses the increase in blood pressure which occurred on cyclosporin alone. The circulating concentration of angiotensin II was significantly less on cyclosporin and nifedipine than on cyclosporin alone (P < 0.05; Student's t test).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Value of thallium myocardial imaging in the prediction of future cardiovascular events in patients with end-stage renal failure.

Chronic renal failure is associated with an increased rate of premature death from cardiovascular disease. Non-invasive identification of asymptomatic cardiac disease should be valuable in the management of such patients, and in selection for transplantation. One hundred and three high-risk patients (66 male, 37 female) with chronic renal failure who were without cardiovascular symptoms were assessed by exercise-graded thallium myocardial perfusion imaging and followed prospectively for 4 years. The development of a cardiovascular event, or death, and the interval to event or death were recorded. Cardiovascular events were documented in 50 patients; in 44 of the 60 patients with a positive thallium test and in only six of the 43 patients with a negative thallium test (test sensitivity 88%, specificity 70%, predictive value of a positive test 73%). Forty patients died, 28 from cardiovascular causes, during the study period. Thallium myocardial perfusion imaging is of value in the prediction of future cardiovascular events in patients with chronic renal failure, and is a useful non-invasive screening technique in patients with end-stage renal failure being considered for transplantation.

Adult↗
PubMed1992

Progressive language disorder due to lobar atrophy.

Sixteen patients with progressive language disorder have been studied longitudinally. Anomia was a prominent presenting characteristic and mutism ultimately occurred. Patients, however, were clinically heterogeneous. Some exhibited nonfluent, agrammatic features, whereas others demonstrated a fluent aphasia, with profound loss of word meaning. Although language disorder remained the sole symptom in a minority of patients, in others an associative agnosia or personality and behavioral changes, or both, emerged. Findings on computed tomography and single photon emission tomography mirrored the areas of dysfunction suggested by the neuropsychological profiles and demonstrated abnormalities restricted to the left hemisphere or involving bilateral frontotemporal cortices. Brains of 3 patients, with distinctive clinical pictures, have been examined at autopsy. Each revealed a focal distribution of atrophy, gliosis and spongiform change, and an absence of senile plaques and neurofibrillary tangles. There was clinical and pathological overlap with frontal lobe dementia. We argue that progressive language disorder is clinically heterogeneous and forms part of a spectrum of clinical presentations of non-Alzheimer lobar atrophy.

Aged↗
PubMed1992

The obstructive diuresis renogram: an appraisal of the significance.

We managed expectantly 23 patients with renal pelvic dilatation and unilaterally obstructive diuresis renograms. Serial renograms showed changes in ipsilateral relative renal function in 8 kidneys (4 deteriorated). Pressure-flow studies demonstrated low pressures on perfusion of 8 kidneys. Eight patients eventually required pyeloplasty, mostly for loin pain. Therefore, serially obstructive diuresis renograms can be associated with preserved renal function, with high pelviocaliceal compliance being a possible explanation.

Adolescent↗
PubMed1992

The F-15 diuresis renogram in suspected obstruction of the upper urinary tract.

The results are presented of the first long-term follow-up study of patients with suspected obstruction of the upper urinary tract investigated by a modified form of diuresis renography (F - 15 renography). The incidence of equivocal results from diuresis renography is significantly reduced by the use of the F - 15 renogram. F - 15 renography provides a reliable assessment of the upper urinary tract in patients with suspected obstruction and is recommended in the investigation of equivocal upper urinary tract dilatation.

Adult↗
PubMed1992

The incidence and severity of hypoxia associated with 99Tcm Technegas ventilation scintigraphy and 99Tcm MAA perfusion scintigraphy.

Inhalation of the ventilatory radiopharmaceutical 99Tcm Technegas leads, in some patients, to symptoms that may be attributed to temporary lowering of oxygen saturation. In order to evaluate this, oxygen saturation was measured by pulse oximetry in a series of patients undergoing Technegas ventilation scintigraphy. A decrease in oxygen saturation was recorded in 87% of the patient group. The mean change, as a percentage of the initial value, was 8.3% (range 1-24%). Hypoxia arising in association with Technegas administration may be reduced by pre-oxygenation. In patients who were pre-oxygenated, oxygen saturation did not fall below 85% (PaO2: 50 mmHg) but in 39% of those not pre-oxygenated the value fell below this level. Oxygen saturation was also monitored in a series of patients undergoing perfusion scintigraphy. In 17% of patients a decrease was recorded (range 2-11%). In view of the large number of perfusion scans performed annually in this department and elsewhere without untoward effect, such temporary decreases in oxygen saturation presumably present no hazard to the patient.

Adolescent↗
PubMed1992

99Tcm-Technegas and krypton-81m ventilation scintigraphy: a comparison in known respiratory disease.

Krypton-81m gas, by virtue of its imaging characteristics, is often considered the "gold standard" for ventilation scintigraphy but its use is restricted by its high cost and limited availability. The new radiopharmaceutical 99Tcm-Technegas, a suspension of ultrafine technetium-99m labelled carbon particles, produces high-quality images of ventilation and has the advantage of continuous availability. As part of our evaluation of Technegas the two were compared in 40 patients with a variety of established respiratory diseases. Disparities were seen in five patients in five diagnostic groups and may be a consequence of the differing physical properties of the two agents and the different inhalation techniques used. In addition two interesting features were noted on the Technegas images. (1) Hot spots were seen in 50% of patients, particularly in those with a degree of airways obstruction; (2) preferential basal deposition of activity was seen in 30%, particularly in patients with idiopathic pulmonary fibrosis. Both features were significantly associated with parameters of pulmonary function indicating obstructive lung disease in the former case and restrictive lung disease in the latter.

Adult↗
PubMed1991

Which vasodilator drug in patients with chronic heart failure? A randomised comparison of captopril and hydralazine.

1. Fifty patients with symptoms due to chronic heart failure despite diuretic therapy were randomised to receive additional treatment with either hydralazine or captopril. The dose was titrated; 24 received hydralazine and 26 captopril up to a maximum daily dosage of 225 mg and 75 mg respectively. Forty-three patients had coronary heart disease and seven dilated cardiomyopathy. 2. Dyspnoea and tiredness were assessed using a visual analogue scale (0-100) before and during 12 weeks' treatment. Captopril produced a significantly greater reduction in breathlessness (F = 31.6, P less than 0.001) and tiredness (F = 65.8, P less than 0.001) compared with hydralazine. 3. There was an increase in treadmill exercise time during treatment with both hydralazine (from 5.5 (3.47-7.53) min to 6.9 (4.87-8.93) min), and captopril (from 5.0 (3.05-6.95) min to 7.8 (5.85-9.75) min), but the degree of improvement was significantly greater in the patients treated with captopril (F = 7.4, P less than 0.001). 4. There was no significant change in right ventricular ejection fraction (from 27.9 (19.3-36.5)% to 28.7 (20.1-37.3)%) or left ventricular ejection fraction (from 22.2 (14.2-30.2)% to 23.9 (15.9-31.9)%) during treatment with hydralazine. However, both right and left ventricular ejection fraction increased significantly during treatment with captopril (from 27.1 (18.9-35.3)% to 32.0 (23.8-40.2)%, P less than 0.05; and from 25.0 (17.2-32.8)% to 29.6 (21.8-37.4)%, P less than 0.05 respectively). 5. These results suggest that in patients with symptoms due to chronic heart failure despite diuretic therapy, treatment with captopril produces a greater symptomatic and haemodynamic improvement than treatment with hydralazine.

Adult↗
PubMed1991

Evaluation of 99Tcm Technegas ventilation scintigraphy in the diagnosis of pulmonary embolism.

In the diagnosis of pulmonary embolism, perfusion lung scintigraphy offers high sensitivity but low specificity. The specificity can be significantly increased by the use of combined ventilation and perfusion studies. Most aspects of perfusion lung scintigraphy are uniformly accepted but the technique of ventilation imaging varies from centre to centre. This study describes a new technique for the performance of ventilation scintigraphy using a suspension of ultrafine carbon particles labelled with 99Tcm ("Technegas"). The technique combines the ready availability of 99Tcm and its optimal imaging properties with an easily administered radiopharmaceutical of particle size sufficiently small to deposit in the alveoli. Of 63 patients studied by conventional perfusion scintigraphy plus Technegas ventilation scintigraphy, images of diagnostic quality were obtained in all. 31 of these patients also had a ventilation study using 81Krm gas and in only one instance did the two methods of ventilation imaging lead to differing interpretations. We conclude that high quality diagnostic images may be obtained using this new technique, which can be made available on both a routine and an emergency basis, thus improving the service provided for patients suspected of having pulmonary embolism.

Adult↗
PubMed1989

Evaluation of myocardial thallium tomography in patients with chest pain.

Thirty-seven patients with chest pain have been studied by exercise thallium tomography and coronary arteriography to assess the accuracy of thallium tomography in the identification of patients with coronary artery disease and to evaluate whether knowledge of clinical data improves this accuracy. Thallium tomography was also used to identify which coronary arteries were stenosed. Thallium tomography when compared with coronary arteriography has a sensitivity of 97%, a specificity of 75%, and an overall accuracy of 92% for the detection of coronary artery disease. When clinical information was made available, these results improved to a sensitivity of 100%, a specificity of 75%, and an overall accuracy of 95%. In the identification of which coronary arteries were stenosed, thallium tomography had a sensitivity of 85%, a specificity of 89%, and an overall accuracy of 86%. These results show that exercise thallium tomography can be an accurate non-invasive screening test in patients with chest pain thought to be angina.

Angina Pectoris↗
PubMed1988

Thallium-201 myocardial imaging in patients with angina pectoris and anomalous aortic origin of the circumflex coronary artery.

Anomalous aortic origin of the circumflex coronary artery is the commonest coronary artery anomaly. In this study, the significance of anomalous aortic origin of the circumflex coronary artery was investigated in seven patients with exertional chest pain using exercise thallium scintigraphy. Five patients with circumflex coronary arterial disease served as controls. Myocardial perfusion was normal in the five patients with a nonstenosed anomalous artery. In these patients, exercise heart rate and blood pressure response were normal. Two patients with a stenosed anomalous circumflex coronary artery and four of the five control patients had posterolateral myocardial perfusion defects. It is concluded that anomalous aortic origin of the circumflex coronary artery does not cause impairment of myocardial perfusion unless it is the site of significant coronary arterial stenosis.

Angina Pectoris↗
PubMed1988

Post-traumatic changes of the temporo-mandibular joint by bone scintigraphy.

13 patients who sustained mandibular trauma were investigated with radiographs and scintiscans. The scintiscans showed abnormal uptake of radiopharmaceutical in the temporomandibular joint (TMJ). In patients with a long history of traumatic arthrosis, there was more positive correlation between the scintiscans, and clinical symptoms and histology than between radiographs, and symptoms and histology. In patients with mandibular body fractures and no TMJ symptoms, the scans showed abnormal uptake in the TMJ in 7/8 joints, in the absence of radiographic abnormality. The significance of the abnormal uptake and the value of scintigraphy is discussed.

Adolescent↗