RESUMO
Osteoporosis patients with chronic kidney disease (CKD) are becoming common in our superaging society. Renal dysfunction causes phosphorus accumulation in the circulating plasma and leads to the development of CKD-mineral bone disorder (MBD). We have previously reported that type III Pi transporter-overexpressing transgenic (Pit-1 TG) rats manifest phosphate (Pi)-dependent podocyte injury. In the present study, we explored the effect of risedronate on Pi-induced podocyte injury in vivo. Pit-1 TG rats and wild-type rats at 5 weeks old were divided into a risedronate-treated group and an untreated group. We subcutaneously administered 5 µg/kg body weight of risedronate or saline twice a week during the experimental period. Risedronate did not alter serum creatinine levels at 5, 8, and 12 weeks of age. However, electron microscopy images showed that thickening of the glomerular basement membrane was improved in the risedronate treatment group. Furthermore, immunostaining for podocyte injury markers revealed that both desmin- and connexin43-positive areas were smaller in the risedronate-treated group than in the untreated group, suggesting that bisphosphonates could rescue Pi-induced podocyte injury. In conclusion, our findings suggest that risedronate could maintain glomerular barrier function by rescuing Pi-induced podocyte injury.
RESUMO
In urinary cytodiagnosis, pathological characterization of atypical cells is sometimes difficult because cells in urine samples tend to be degenerated. To overcome this problem, we adopted serial examination under light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Five patients with transitional cell carcinoma primarily developed in the bladder, three patients with dysplastic cells, and one patient with metastatic and infiltrative colorectal carcinoma were subjects of the present study. Sample cells were smeared on a film slide especially suitable for serial use (a film slide used in X-ray diagnosis), fixed in 1% glutaraldehyde (GA) for 30 min, stained with Papanicolaou (Pap) staining, and immediately processed for fixation in 2% paraformal-dehyde (PA) and 2.5% GA. Slides were postfixed in 0.5% osmium tetroxide. Then, cell samples were subjected to a series of observations under LM, SEM, and TEM. One of three patients in whom dysplastic cells were suggested under LM was finally diagnosed as transitional cell carcinoma by subsequent examination under SEM followed by TEM. Thus, serial use of LM, SEM, and TEM proved useful in discriminating transitional cell carcinoma (grade 1) from dysplastic cells and also in distinguishing metastatic tumor cells from primary tumor cells in urine samples.
