Clinicopathological study of kidneys from patients on chronic dialysis

Kidneys removed from 58 pediatric patients at renal transplantation (except 3 cases), who had developed chronic renal failure and were maintained on dialysis, were investigated histopathologically, and the clinical profiles were taken into account. The patients ranged in age from 2 to 24 years, with an average of 11.2 years. The duration of dialysis ranged from 0.5 to 63 months, with an average of 12.6 months. The kidneys, which were conventionally prepared for histological observation, were subjectively divided into three groups depending on the degree of remaining nephrons. Patients with completely atrophic type (type 1), incompletely atrophic type (type 2), and mixed type of atrophy and hypertrophy (type 3) had a duration of dialysis of 20.0, 12.3, 6.3 months, respectively (Type 1 greater than Type 3, P less than 0.01). A correlation between histology and function was demonstrated, since urinary output was more than 200 ml/day in most of the type 3 patients, and less than 20 ml/day in all of the patients with type 1. The findings suggest that the functioning nephrons that remained at the beginning of dialysis generally become atrophic within one year after the initiation of dialysis. The ratio of kidney weight to body weight showed a significant negative correlation with both the duration of dialysis and that of illness. The histopathological changes seen in kidneys of patients on dialysis were reviewed. The findings suggested that certain changes, unusual epithelial proliferations an oxalate deposition, are associated with persisting renal function rather than the duration of dialysis.     

Minor contribution of hepatocytes to collagen production in normal and early fibrotic rat livers

Hepatocyte contribution to hepatic collagen production in vivo was estimated in rats, based on the fact that ornithine is used for protein synthesis in the liver as arginine after conversion by way of the urea cycle only by hepatocytes. From rats given a mixture of [14C] ornithine and [3H]arginine, hepatic collagen and serum albumin were obtained. The hepatocyte contribution was calculated from the 14C and 3H in arginine purified from collagen and albumin by high performance liquid chromatography. The contribution was less than 10% of total collagen production in normal and early fibrotic livers induced by a single dose of carbon tetrachloride or dimethylnitrosamine. We conclude that hepatocytes may play a minor role in collagen production in normal and early fibrotic rat livers.     

Synthesis and antiviral activity of sulfonamidobenzophenone oximes and sulfonamidobenzamides

To find antiviral agents, various sulfonamidobenzophenone oximes (II) were synthesized from the appropriate m-sulfonamidobenzophenones by hydroxylamine reaction. The reaction products were generally obtained as syn/anti mixtures which were separable by fractional crystallization. The anti isomer had more potent antipoliovirus activity than the syn isomer. Various sulfonamidobenzamides (III) which were structurally related to II were synthesized by the reactions of amino-substituted benzamides with sulfuryl chloride or amines with (aminosulfonyl)benzoyl chloride. Antiviral activity was examined by the plaque-inhibition test. Compounds 5, 36, and 69 exhibited strong antipicornavirus activity. The structure-activity relationships are discussed.     

Modulation of glial cell signaling by adenosine and pharmacological reinforcement

In view of the increasing evidence that a pathological glial activation plays a significant role in the development of neurodegenerative diseases, we investigated the underlying molecular signaling as a possible target for a pharmacological therapy. Here, we are particularly focusing on the endogenous modulation of the Ca²⁺ and cyclic nucleotide-dependent signaling by the nucleoside adenosine and its reinforcement by the xanthine derivative propentofylline (PPF). As an experimental model, we used cultured rat microglial cells and astrocytes that are immature, show a high proliferation rate, and resemble in several aspects pathologically activated glial cells. A prolonged increase of the cellular cAMP level favored the differentiation of cultured astrocytes and associated properties required for the physiological nerve cell function. On the other hand, a strengthening of the cyclic nucleotide-dependent signaling inhibited potentially neurotoxic properties of cultured microglial cells. Similar effects were obtained by treatment with propentofylline, which mimicked modulatory adenosine effects and increased the intracellular level of cAMP and cGMP. Such a pharmacological glial cell conditioning, obtained by modifying the strength and the timing of these second messengers, may provide a therapy of neurodegenerative diseases in which a pathological activation of microglial cells and astrocytes is discussed to play a pathogenic role.     

Expression of the alpha1D subunit of the L-type voltage gated calcium channel in human liver

Calcium channel blocker is useful for a variety of purposes and is effective for preventing hepatitis elicited by different inducers, suggesting its possible clinical application for treating hepatitis. The alpha1-subunit of the dihydropyridine-sensitive L-type calcium channel is a target of calcium channel blocker. For clinical application of calcium channel blocker, it is important to analyze the expression of the L-type calcium channel in the liver. However, the subtype of the L-type calcium channel alpha1-subunit expressed in the liver was not known. In the present study, the alpha1-subunit of the calcium channel expressed in human liver was systematically analyzed. The alpha1D subunit of the dihydropyridine-sensitive L-type voltage gated calcium channel is expressed relatively strongly in the liver and may play an important role in the liver.