Rotavirus gastroenteritis‐associated urinary ammonium acid urate crystals

Although ammonium acid urate (AAU) calculi are extremely rare renal stone components, it was recently found that many urinary tract calculi that cause post‐renal renal failure in rotavirus (RV) gastroenteritis are AAU calculi. The mechanism of AAU calculi development in RV gastroenteritis has not been fully elucidated. We analyzed data from eight RV gastroenteritis patients who transiently had AAU crystals in their urinary sediment. In these patients, formation of AAU crystals occurred earlier than the formation of AAU calculi. No difference was observed in serum and urine uric acid levels between RV gastroenteritis patients with or without AAU crystals. Interestingly, fractional excretion of sodium was extremely low among patients with AAU crystals. These results suggest that the formation of AAU crystals might not be due to excretion of uric acid, but excretion of sodium.     

Changes of cardiac performance in renal failure.

Clinical and experimental studies were carried out in order to evaluate the role of myocardial dysfunction in the genesis of circulatory congestion associated with renal failure. Among the patients with chronic renal failure, those with circulatory congestion had greater blood volume and higher venous pressure while lower cardiac index and stroke work index than those without circulatory congestion. After peritoneal dialysis, although blood volume and venous pressure decreased in both groups, cardiac index increased in the former while it decreased in the latter group. In 15 dogs, acute renal failure was produced by ligating both ureters. As uremia developed, blood volume and left ventricular end-diastolic pressure increased with or without an increase in cardiac index. The depression of ventricular function curve was evident in all the dogs. The peritoneal dialysis performed at this stage resulted in a prompt recovery of left ventricular end-diastolic pressure with minimum change in cardiac index. The measurement of dp/dt/IIT also indicated a depression of myocardial contractility at uremic stage and its recovery after dialysis. We conclude that impairment of myocardial function is implicated in the development of circulatory congestion in renal failure.     

Functional giant parathyroid cyst with high concentration of CA19-9 in cystic fluid

A 63-year-old man was admitted to our hospital for the evaluation of hypercalcemia and anterior neck mass. Laboratory findings revealed hypercalcemia, hypophosphatemia, and hypercalciuria, as well as elevated serum levels of parathyroid hormone (PTH) and alkaline phosphatase. Computerized tomography and magnetic resonance images showed that the mass contained a cystic area. Parathyroid scintigraphy using either 99mTc-sestamibi alone or 201Tl-chloride in conjunction with 99mTc-pertechnetate for thyroid image subtraction showed uptake of the radioactivity into the cyst wall, suggesting that the mass originated from the parathyroid. Fine needle aspiration biopsy revealed that the cyst fluid was serous and bloody with extremely high concentrations of both PTH and CA19-9. The patient was diagnosed as primary hyperparathyroidism caused by parathyroid cyst and cervical exploration was performed. The cyst was dissected away along with the right lobe of the thyroid gland. After tumor removal, serum calcium and PTH levels were normalized. Histological study showed that the tumor possessed malignant potential with capsular invasion as well as moderate cellular atypia with trabecular pattern in arrangement. Parathyroid cells in the wall of the cystic tumor were immunostained positively for CA19-9, suggesting that CA19-9 in the cyst fluid was produced from the cells.     

Native valve salvage for post-traumatic tricuspid regurgitation

We describe two cases of successful management by native valve salvage of an uncommon tricuspid valve regurgitation following blunt chest trauma. The two patients were diagnosed 13 years and six years, respectively, after the trauma. In both cases, tricuspid valvular insufficiency was caused by anterior leaflet prolapse due to chordal and papillary muscle rupture associated with annular dilatation. Operative repair with implantation of artificial chordae, papillary muscle reinsertion and ring annuloplasty resulted in complete recovery. The need for increased awareness of this lesion in patients suffering blunt chest trauma is emphasized, and the relevant literature reviewed.     

Acute parvovirus B19 infection mimicking chronic fatigue syndrome

A Japanese woman developed prolonged fatigue, neck and shoulder pain, headache, pyrexia, insomnia, anorexia, lymphadenopathy, and diarrhea for two months. She had experienced various stressors before these symptoms developed. Serological test demonstrated that she had acute parvovirus B19 infection. Major depressive disorder was also diagnosed by a psychiatrist. Her symptoms disappeared after administration of selective serotonin reuptake inhibitors and oriental herbs, although human parvovirus B19 viral genome has been present in her serum for nine months. These findings suggest that parvovirus B19 causes clinical features similar to those of chronic fatigue syndrome in cases who have prior life stressors.     

Beraprost sodium,prostacyclin analogue,attenuates glomerular hyperfiltration and glomerular macrophage infiltration by modulating ecNOS expression in diabetic rats

Stable prostacyclin analogue, beraprost sodium (BPS) has recently been reported to attenuate glomerular hyperfiltration in diabetic rats, however, the mechanism has been still unknown. We previously reported that overexpression of endothelial cell nitric oxide synthase (ecNOS) in afferent arterioles and glomeruli induce inappropriate dilatation of afferent arterioles and glomerular hyperfiltration through overproduction of nitric oxide in early stage of diabetic nephropathy. In this study, we tested the hypothesis that BPS ameliorates glomerular hyperfiltration through modulating ecNOS expression in diabetic nephropathy. Furthermore, we examined the effects of BPS on the expression of intercellular adhesion molecule-1 (ICAM-1) and macrophage infiltration in diabetic glomeruli, because glomerular hyperfiltration induces the expression of ICAM-1 resulting in macrophage infiltration. Male Sprague-Dawley (SD) rats were administered continuously with BPS for 4 weeks after induction of diabetes by streptozotocin. In diabetic rats, the diameters of afferent arterioles, glomerular volume, creatinine clearance and urinary excretion of albumin and NO2/NO3 were increased as compared with non-diabetic control rats. Treatment with BPS improved these changes. The expression of ecNOS was increased in afferent arterioles and glomeruli in diabetic rats and suppressed by BPS. Prostacyclin receptor was expressed along afferent arterioles. Our results suggest that BPS attenuates glomerular hyperfiltration by modulating ecNOS expression in early stage of diabetic nephropathy. Moreover, BPS may inhibit ICAM-1-dependent infiltration of macrophages in diabetic glomeruli.