Comparison of adenosine and exercise stress test for quantitative perfusion imaging in patients on beta-blocker therapy.

Unlabelled: Beta-blocker therapy is used to decrease myocardial ischemia during exercise but may cause suboptimal diagnostic performance in exercise stress testing. The aim of the present study was to compare results of quantitative technetium-99-sestamibi single photon emission tomography (SPECT), following exercise stress test or pharmacological stress test with adenosine. We chose adenosine as comparison, since betablockers may not interfere with adenosine induced vasodilatation and therefore possibly may not interfere with its diagnostic performance.

Primary lymphoma of the heart.

Primary tumors of the heart are rare. Most patients have very few clinical manifestations and present with uncharacteristic symptoms, often misdiagnosed as heart failure. As investigation techniques such as echocardiography, computed tomography and magnetic resonance imaging become more widespread, the clinician will be confronted with the diagnosing of cardiac masses.

Captopril-induced changes in MAG3 clearance in patients with renal arterial stenosis and the effect of renal angioplasty.

Unlabelled: Angiotensin-converting enzyme inhibition by captopril decreases renal (131)I-o-iodohippurate sodium or iothalamate extraction in patients with renal artery stenosis (RAS). This study investigated the effect of captopril on another renal radiopharmaceutical, (99m)Tc-mercaptoacetyltriglycine (MAG3), in particular its plasma clearance.

Methods: Three groups of patients were studied.

Tubular reabsorption of technetium-99m-DMSA.

Unlabelled: Intrarenal handling of 99mTc-DMSA is still controversial, particularly in the existence of tubular reabsorption from the tubular fluid. Experiments were performed with micropuncture technique on the rat kidney in an attempt to elucidate this question.

Methods: The concentration profile of 99mTc-DMSA along the nephron was measured in fluid from Bowman's space of surface glomeruli and from the proximal and distal tubules collected by micropuncture.

Renal effects of aspirin and low dose methotrexate in rheumatoid arthritis.

Objectives: The aim of this investigation was to study the glomerular and tubular effects of low doses (15 mg) of methotrexate in patients with rheumatoid arthritis with and without combined treatment with aspirin (2 g single dose).

Methods: Renal function was measured by the plasma clearance of EDTA labelled with chromium-51 (51Cr-EDTA) and mercaptoacetyltriglycine labelled with technetium-99m (99mTc-MAG-3).

Results: Clearance of 51Cr-EDTA was reduced from 98 (6) to 87 (5) ml/min (mean (SEM)) for patients receiving methotrexate only and further reduced to 76 (5) ml/min for patients receiving methotrexate and aspirin.

Coronary angiographic changes during 2 years after myocardial infarction largely undetected by repeated tomographic thallium-201 scintigraphy and not reflected by clinical symptoms.

Repeated coronary angiographies and single photon emission computed tomographies (SPECT) were performed at 9 and 33 months after myocardial infarction (MI) in 47 young men. Coronary lesions were classified in eight grades with respect to the reduction of the luminal diameter. The progression and regression of two steps or more in lesions of grade 2 or more, the recanalization of coronary thrombosis and an increase in collaterals were recorded.

Renal effects of low dose methotrexate in rheumatoid arthritis.

Objective: Methotrexate (MTX) treatment at high doses may cause renal failure. The effects of treatment with low MTX doses on kidney function are, however, unknown. The objective of our study was to investigate the effect of low MTX doses on kidney function.

Influence of excessive weight loss on respiratory function. A study of obese patients following gastroplasty.

The influence of excessive weight loss, with decreased muscle mass, on pulmonary function was evaluated in 16 obese patients without clinical evidence of respiratory disease. Weight loss was induced with vertical banded gastroplasty. Six nonobese age-matched patients undergoing elective cholecystectomy acted as controls.

Estimation of technetium 99m mercaptoacetyltriglycine plasma clearance by use of one single plasma sample.

Recent studies have shown that technetium 99m mercaptoacetyltriglycine (MAG-3) is a suitable replacement for iodine 131 or 123 hippurate in gamma-camera renography. Also, the determination of its clearance is of value, since it correlates well with that of hippurate and thus may be an indirect measure of renal plasma flow. In order to simplify the clearance method we developed formulas for the estimation of plasma clearance of MAG-3 based on a single plasma sample and compared them with the multiple sample method based on 7 plasma samples.

A comparative study of renal scintigraphy and clearance with technetium-99m-MAG3 and iodine-123-hippurate in patients with renal disorders.

The aim of this study was to compare kit prepared technetium-99m-mercaptoacetyltriglycine (99mTc-MAG3) with our routine radiopharmaceutical, iodine-123-hippurate our routine radiopharmaceutical, iodine-123-hippurate ([123I]OIH) for renal dynamic scintigraphy. Seventeen patients with different nephrologic disorders or hypertension were first studied with OIH and then reinvestigated with MAG3 2-8 days later. Renal MAG3 gamma camera images were almost identical with those of OIH except for higher (p less than 0.

Glomerular filtration and tubular secretion of MAG-3 in the rat kidney.

Technetium-99m mercaptoacetyltriglycine (MAG-3) has recently been introduced as a new radiopharmaceutical for dynamic renal scintigraphy. To elucidate the mechanism of renal excretion, micropuncture experiments were performed in rat kidneys for direct measurements of glomerular filtration and tubular secretory capacity. Fluid of Bowman space was collected from superficial glomeruli and analyzed for its contents of [99mTc]MAG-3, [125I]hippurate and [3H]inulin during constant infusion of these compounds.

Influence of water-diuresis or saline volume expansion on deep nephron tubuloglomerular feedback.

We have recently demonstrated the existence of a tubuloglomerular feedback mechanism in juxtamedullary nephrons in rat kidneys during antidiuresis. In the present experiments, we have investigated the influence of water-diuresis on Munich Wistar rats and in homozygote Brattleboro rats. We have also observed the effect of saline volume expansion on the tubuloglomerular feedback of juxtamedullary nephrons in Munich Wistar rats.

Effect of cyclosporine A on renal electrolyte transport: whole kidney and Henle loop study.

We investigated whole kidney function and electrolyte transport in the loop of Henle of surface nephrons using micropuncture in rats pretreated for 5-7 days with cyclosporine A (CSA, 15 mg/kg). We also studied whether the kidney was able to increase K+ excretion acutely after a period of acute i.v.

Renal and extrarenal handling of a new imaging compound (99m-Tc-MAG-3) in the rat.

We investigated the renal clearance, the extrarenal clearance, the biodistribution, the plasma extraction ratio and the imaging quality on a scintillation camera of a new substance: 99mTc-mercaptoacetyltriglycine (MAG-3) in rats. Simultaneously 125I-hippurate (OIH) and 51Cr-EDTA were used as reference substances. In scintillation camera studies, 123I-hippurate served as reference.

Evaluation of hydronephrosis in pregnancy using ultrasound and renography.

The value of ultrasound and 131-Hippuran renography for diagnosing hydronephrosis during pregnancy was investigated. In a control series of 31 symptom-free pregnant women the ultrasonographically measured renal pelvic diameters in the three trimesters were 5, 10 and 12 mm on the right side and 3, 4 and 5 on the left, respectively. In ten healthy non-pregnant women the pelvic diameter varied from 3 to 9 mm on the right side and from 2 to 6 mm on the left side when measured during antidiuresis and water diuresis.

Evidence for tubuloglomerular feedback in juxtamedullary nephrons of young rats.

To determine whether the filtration rate of juxtamedullary nephrons is regulated by tubuloglomerular feedback (TGF), we developed two micropuncture techniques suitable for the papilla of young rats. One consisted of measuring the tubular flow in descending limbs of Henle loops (VDLH) while the ascending limbs of the loop of Henle (ALH) were perfused at various rates with three different solutions: modified Ringer, artificial Henle loop solution, and Ringer containing 10(-4) M furosemide. SNGFR was also measured in several juxtamedullary nephrons.