Origin and phenotypic features of hyperplastic epithelial cells in collapsing glomerulopathy

The characteristic pathological feature of collapsing glomerulopathy (CG) is marked cell hyperplasia and hypertrophy within the glomeruli. The present study investigated the phenotypic alteration of hyperplastic epithelial cells in CG to determine their origin. Renal biopsy specimens from two patients with CG were analyzed by immunohistochemical staining, using markers for podocytes (PHM-5), parietal epithelial cells (PECs; cytokeratin), and cell proliferation (Ki-67). In collapsed glomeruli, hyperplastic and hypertrophic epithelial cells were frequently connected to PECs and collapsed glomerular basement membranes (GBMs). These epithelial cells were more often Ki-67 positive and expressed cytokeratin, whereas PHM-5 was almost invariably negative. Serial section analysis showed that a small number of hyperplastic epithelial cells expressed both PHM-5 and cytokeratin, suggesting phenotypic conversion between podocytes and PECs. Moreover, cytokeratin-positive cells were associated with the sclerotic glomerular segments. Thus, we suggest that the majority of hyperplastic and hypertrophic epithelial cells in CG are of PEC origin. These epithelial features may participate in the development of characteristic tuft collapse and glomerulosclerosis in CG.     

Structures of the novel anthraquinone antitumor antibiotics, DC92-B and DC92-D

The structures of the new anthraquinone antitumor antibiotic DC92-B and its photodegradation product DC92-D were determined by their spectral studies. DC92-B and D are pluramycin antibiotics, related to hedamycin which possess a characteristic ring F and a side chain containing a cis-epoxide and terminal dimethyl.     

Successful removal of an angiographically occult arteriovenous malformation of the ventral medulla

A case with an angiographically occult arteriovenous malformation (AVM) of the ventral medulla presenting with progressive motor and sensory deficits is reported. The AVM, about 1 x 1 x 0.5 cm in size, accompanied by intramedullary haematoma, was successfully removed through a small incision placed in the right ventrolateral medulla between the vagus and the hypoglossal nerves. The patient's neurological symptoms improved after surgery.     

Age-dependent Alteration of the Serum-unbound Fraction of Nicardipine,a Calcium-channel Blocker,in Man

To determine whether the age-dependent increase in the pharmacological effect of calcium-channel blockers is a result of age-dependent alteration of the unbound fraction the drug in serum, the unbound fraction of the nicardipine was investigated in the serum of 38 adults. The unbound concentration of nicardipine in serum to which nicardipine (205.4 ng mL^?1) had been added was determined by ultracentrifugation to range from 0.49 to 4.01% (mean±s.d., 1.55 ± 0.78%). Non-glycosylated albumin was most strongly correlated with age (r = 0.901). Total bilirubin was weakly correlated with age whereas levels of α-1-acid glycoprotein, triglycerides and glycosylated albumin were not correlated with age. A significant (P < 0.01) linear correlation was obtained between the unbound fraction of nicardipine and parameters such as age, albumin, albumin/globulin ratio, albumin/glycosylated albumin ratio, non-glycosylated albumin and total bilirubin. To assess the relative effect of each variable on the unbound fraction of nicardipine, stepwise multiple linear regression was performed using age and biochemical parameters. The three variables (non-glycosylated albumin, total bilirubin and age) were entered into the regression equation. The results of this study showed that the major ligand of nicardipine in serum was non-glycosylated albumin, which decreased with age. It was, moreover, shown that the serum-unbound concentration of nicardipine increased with age. This finding would be one factor accounting for the increase in the pharmacological effect of nicardipine with age. In addition, our predicted model for the unbound fraction of nicardipine might be useful in determining the appropriate nicardipine dose for the elderly.     

An absence of structural changes in the proximal femur with osteoporosis

The hypothesis that osteoporosis occurs not as a preferential loss of the tensile trabeculae but as a general loss of bone was tested by using bone mineral densitometry and an indention test on dissected proximal femora. As osteoporosis advanced a significantly correlated decrease was found in both bone mineral density and mechanical properties between the principal compressive and tensile trabeculae. The decrease correlated with a decrease in the Singh index. These findings led to the conclusion that a sequential bone loss from the tensile trabeculae to the compressive ones did not occur as Singh reported, but instead a generalized loss of bone mineral in both the tensile and compressive trabeculae supervened. The structural changes, on which the grading system by Singh was based, were not observed in the proximal femur affected by osteoporosis.