Kouichi Taura

Aldosterone breakthrough during therapy with angiotensin‐converting enzyme inhibitors and angiotensin II receptor blockers in proteinuric patients with immunoglobulin A nephropathy

Background:  We are investigating whether aldosterone breakthrough negatively impacts on the antiproteinuric effects of angiotensin‐converting enzyme (ACE) inhibitors and/or angiotensin II receptor blockers (ARB).

Prednisolone Co-Administered with Losartan Confers Renoprotection in Patients with IgA Nephropathy

Background.Treatment options for progressive IgA nephropathy are limited. Methods. We performed a small, randomized controlled trial to evaluate the effects of prednisolone (PSL, 30 mg/dL, gradually tapered to 5 mg/dL over two years) plus 50 mg/day of losartan (LST, an angiotensin II receptor blocker) or PSL alone on IgA nephropathy. We separated 38 patients (age, 33 ± 11 years; creatinine clearance, 103 ± 31 mL/min; proteinuria, 1.6 ± 0.5 g/day) into two groups that were treated with either PSL plus LST or PSL alone, and compared the proteinuria and creatinine clearance after two years. Baseline and histopathological data did not significantly differ between the two groups. Results. Two years of treatment in both groups significantly decreased proteinuria compared with baseline, and PSL plus LST (from 1.6 ± 0.6 to 0.3 ± 0.1 g/day, p < 0.05) was more effective than PSL alone (from 1.6 ± 0.3 to 0.5 ± 0.1 g/day, p < 0.05). Creatinine clearance in both groups was similar at the start of study but significantly differed at the end of the study (PSL plus LST, 104.3 ± 36.4 to 100.4 ± 38.9 mL/min; PSL alone, 103.4 ± 28.5 to 84.8 ± 34.3 mL/min, p < 0.05). Conclusions. Combined therapy with PSL plus LST appears to be more effective than PSL alone in reducing proteinuria and protecting renal function in patients with IgA nephropathy.

Relationship between Carotid Artery Intima-Media Thickness and Atherosclerotic Renal Artery Stenosis in Type 2 Diabetes with Hypertension

Aim: To assess the relation between intima-media thickness (IMT) of the common carotid artery and atherosclerotic renal artery stenosis (ARAS) ≧50% (one or both renal arteries) in type 2 diabetic patients with hypertension. Methods: We performed a retrospective study of type 2 diabetic patients with hypertension who underwent magnetic resonance angiography or digital subtraction angiography for renal artery stenosis at the National Cardiovascular Center or at the Nagasaki Municipal Medical Center between May 1999 and May 2001. Renal artery stenosis was defined as a narrowing of the artery to at least 50% of normal. Thirty type 2 diabetic patients with hypertension (17 men and 13 women, mean age 65.4 ± 7.6 years) were identified and divided into two groups: those with ARAS in one or both renal arteries (n = 15) and those without ARAS (n = 15). We used high-resolution B-mode ultrasonography to measure the IMT of the common carotid artery. Results: With and without ARAS were 9 men and 6 women (mean age 65.0 ± 7.6 years) and 8 men and 7 women (mean age 65.7 ± 6.8 years), respectively. The IMT of the carotid artery was significantly greater in patients with ARAS than in patients without ARAS (1.07 ± 0.10 vs. 0.84 ± 0.12 mm, p < 0.01). However, the only clinical findings that statistically significantly differed were systolic blood pressure and plasma renin activity. Conclusion: Our findings suggest that the measurement of the IMT of the carotid artery may be useful as a noninvasive screening method for the defection of ARAS even in asymptomatic type 2 diabetic patients.

Prognosis of Patients with Rounded Atelectasis Undergoing Long-Term Hemodialysis

We present 4 patients undergoing hemodialysis in whom thoracic computed tomography (CT) suggested a diagnosis of rounded atelectasis (RA) with pleural effusion. The clinical setting and follow-up CT of all 4 patients confirmed this diagnosis. The pleural fluid of each appeared serosanguineous or hemorrhagic and predominantly consisted of lymphocytes. Biochemical analysis of this fluid revealed high levels of total protein, lactate dehydrogenase and glucose. Bacterial culture and polymerase chain reaction for Mycobacterium tuberculosis DNA was negative. Pleural biopsy specimens from 2 of the 4 patients showed evidence of fibrinous change and mesothelial cell hyperplasia. Pleural effusion from all 4 patients did not respond to either fluid restriction or aggressive hemodialysis-induced dehydration. The subsequent clinical course and thoracentesis were repeated, and in 1 patient, this was followed by tetracycline pleurodesis. However, 2 patients died during pre-pleurodesis and 1 died during post-pleurodesis, all due to respiratory failure. We propose that the clinical setting and follow-up thoracic CT and thoracentesis of patients receiving long-term hemodialysis confirmed a diagnosis of rounded atelectasis with uremic pleural effusion. We also propose that the prognosis of patients with refractory pleural effusion receiving long-term hemodialysis would be improved by early pleurodesis.

Acetazolamide assisted Tc-99m MAG3 renography to assess renal blood flow reserve

Objective: The present study examines whether or not baseline and acetazolamide (ACZ) Tc-99m MAG3 renography can assess renal blood flow reserve.Methods: Renography proceeded for 50 min after sequential injections of 370 MBq Tc-99m MAG3 for baseline renography and 10 min after a 1,000 mg injection of ACZ for ACZ renography. Effective renal plasma flow of renal cortex (cERPF) in each kidney and the percentage change in cERPF of those parameters (ΔERPF) were obtained before and after the administration of ACZ in 10 subjects without hypertension or diabetes (normal group), in 10 with essential hypertension (hypertensive group) and in 10 who had Type 2 diabetes with hypertension (diabetic group). A placebo test was performed in the 10 without hypertension or diabetes using distilled water instead of ACZ (placebo group).Results: The placebo test performed in the 10 without hypertension or diabetes using distilled water instead of ACZ indicated that the parameter variance between the two types of renogram was below 3.2%. The cERPF of baseline and ACZ Tc-99m MAG3 renography and δERPF in the normal, hypertensive and diabetic groups were 89±10 and 110±10 ml/min, 89±14 and 117±22 ml/min, 100±23 and 112±23 ml/min, respectively, and 24.5±13.5%, 26.0±9.7% and 12.3±11.1%, respectively. The difference in the cERPF value was significant in the normal and hypertensive groups whereas this did not change in the diabetic group before or after ACZ administration.Conclusions: We suggested that the δERPF determined by baseline and ACZ Tc-99m MAG3 renography is a useful parameter for assessing renal blood flow reserve.

Evaluation of Tc-99m MAG3 dynamic renal scintigraphy with an aneurysmal type renal arteriovenous fistula.

Tc-99m MAG3 renal scintigraphy was performed before and after transcatheter steel coil embolization in a 55-year-old man with an aneurysmal type left renal arteriovenous fistula (AVF). Before embolization, dynamic renal scintigraphy revealed characteristic accumulation compatible with the hemodynamics of an aneurysmal type AVF in the vascular phase. Embolization changed the split renal function in the treated side, and shunt flow through the fistula disappeared. Dynamic renal scintigraphy might be very useful in evaluating patients with hemodynamic renal AVF scheduled for transcatheter embolization.