Hybridization of non-sulfonylurea insulin secretagogue and thiazolidinedione-derived insulin sensitizer.

Hybrid compounds of non-sulfonylurea insulinotropic agents and thiazolidinedione-derived insulin-sensitizing agents were designed and synthesized. The benzylidenesuccinic acid derivative 24 was equal both to nateglinide in potency of insulin-releasing activity and to pioglitazone in insulin-sensitizing activity.

Effects of graded levels of dietary casein and corn oil on total cholesterol and triacylglycerol in plasma and liver of rats.

With the intention of examining the effects of dietary protein and oil levels on total cholesterol (T-CHOL) and triacylglycerol (TG) concentrations in the plasma and liver, male Wistar rats, weighing about 170 g, were fed diets containing graded levels of casein and corn oil for 2 wk. At the 5, 20, and 30% levels of dietary corn oil, plasma T-CHOL concentrations were generally enhanced in proportion to the rise of dietary casein level, but plasma TG contents were scarcely influenced by the level. At the 8 to 35% casein levels, plasma T-CHOL and TG concentrations were the highest at the 5% corn oil level, followed in order by the 20 and 30% levels of oil. At the 5 and 20% oil levels, hepatic T-CHOL contents were hardly changed at the 8 to 30% casein levels, but enhanced at the 35% casein level. At the 30% oil level, the T-CHOL contents tended to be changed proportionally to casein levels. At all levels of casein, hepatic T-CHOL contents tended to be relatively high at the 30% corn oil, middle at the 20% oil, and low at the 5% one. At each corn oil level, TG contents in the liver tended to be elevated at the 8 to 15% casein levels and highly preserved at the 15 to 25% ones. Then, the raised TG contents declined at the 5 and 20% levels of corn oil and remained constant at the 30% oil. At each casein level, the contents of hepatic TG were generally high at the 30% oil level, followed in order by the 20 and 5% oil levels. These results indicated that plasma and liver T-CHOL concentrations were proportionately enhnaced by the increase in casein level, and plasma TG contents were hardly affected by the level and hepatic TG ones were lowered by relatively lower or higher casein level, and the rise in corn oil level generally reduced plasma T-CHOL and TG concentrations, but raised hepatic ones.

(-)-Epigallocatechin gallate inhibits mos activation-mediated xenopus oocyte maturation induced by progesterone.

(-)-Epigallocatechin gallate (EGCG), one of the constituents of green tea known to have a tumor preventing effect, inhibited maturation of Xenopus laevis oocytes induced by progesterone when this polyphenol was microinjected into oocytes at a final concentration of about 1 mM. Western blot and activity measurement analyses showed that Mos translation and the subsequent activations of mitogen-activated protein kinase and p90(rsk), probably by protein phosphorylation, seemed to have been inhibited by the microinjection of EGCG. These results suggest that EGCG may have the ability to control Xenopus oocyte maturation at least during the stage of Mos activation.

Local tissue irritating effects and adjuvant activities of calcium phosphate and aluminium hydroxide with different physical properties.

Effects of calcium phosphate and aluminium hydroxide adjuvants with different physical properties were examined in guinea pigs for local histopathological reactions, electron-microscopical changes of macrophages and adjuvanticity on total IgG antibody response to subcutaneously administered ovalbumin (OVA) and tetanus toxoid (TT). Calcium phosphate gel (Ca-gel) induced active inflammatory reactions consisting of neutrophils (pseudoeosinophils) and foamy macrophages associated with many multinuclear giant cells for at least 4 weeks. Aluminium hydroxide gel (Al-gel) also elicited granulomatous inflammatory reactions consisting mainly of macrophages with foamy cytoplasm, small lymphocytes and giant cells at the injection sites for up to 8 weeks or longer. Severity of local tissue irritation due to calcium phosphate gel (Ca-gel) was similar to that due to Al-gel except for the duration of the inflammatory reactions. Calcium phosphate suspension (Ca-sus)-induced local reactions completely ceased by the 4th week, while aluminium hydroxide suspension (Al-sus)-induced reactions were seen up to the 8th week. Electron-microscopical observations showed that both Al-gel and Al-sus caused damage of macrophages. The adjuvant activity of Al-gel for OVA or TT was significantly stronger than that of any other adjuvant material, whereas those of Ca-gel and Ca-sus were not seen at a dose of 3 mg calcium phosphate per millilitre. Al-sus-TT at a dose of 3 mg aluminium hydroxide per millilitre induced very low levels of antibody. These results suggest that calcium phosphate adjuvant may not be an useful alternative to Al adjuvant.

Eosinophilic neuronal inclusions in the thalamus of ageing B6C3F1 mice.

The age-related incidence of thalamic neuronal inclusions in the brains of aged B6C3F1 mice and their histopathological and ultrastructural features were studied. Round to oval or rod-shaped eosinophilic inclusions, which were frequently observed in the neurons of the thalamic area, were stained positively with phosphotungstic acid haematoxylin. The inclusions were detected first at 32 weeks of age and the incidence and severity were higher in older animals, all of the mice being affected after 58 weeks of age. Ultrastructurally, the inclusions appeared as sheaves of parallel osmiophilic filaments in the perikaryon of the neurons in the thalamus. Thus thalamic neuronal inclusions in mice seem to be age-related, but their significance remains unclear.

Relationship between hemolytic activity and adsorption capacity of aluminum hydroxide and calcium phosphate as immunological adjuvants for biologicals.

Aluminum hydroxide (Al) and calcium phosphate (Ca) gels have been used as vaccine adjuvants for many years. We investigated mechanism of the hemolytic activities of both adjuvant materials. The hemolytic activity of each gel depended on the gel dose. The adsorption capacities and the hemolytic activities of both adjuvants decreased as the concentration of phosphate increased in a gel-washing solution. A positive correlation between the hemolytic activity and the adsorption capacity was found in Al-gel. A disruptive effect of Ca-gel on membrane of erythrocytes was shown by electron microscopy. Ca-gel required more than 10 times as much pre-adsorbed ovalbumin as did Al-gel to inhibit the hemolysis. These results suggest that the hemolytic activity of both adjuvant materials depended mainly on the adsorption ability, and it may be useful to control the adsorption ability of adjuvants to reduce their hemolytic activity.

Spontaneous globoid mineralization in the cerebellum of rats.

Cerebellar globoid mineralization in two rats was examined by light and electron microscopy, and by X-ray microanalysis. The mineralization was round to oval in shape; it varied in size and was positive for the periodic acid-Schiff and von Kossa reactions. Ultrastructurally, a concentric lamellar structure was prominent in moderately electron-dense depositions. Elemental analysis revealed the presence of large amounts of calcium and phosphorus, and small amounts of zinc, potassium and aluminum.

Studies on the toxicities of aluminium hydroxide and calcium phosphate as immunological adjuvants for vaccines.

Aluminium hydroxide (Al) and calcium phosphate (Ca) have been used for many years as immunological adjuvants for biologicals. We investigated the toxic effects of both adjuvants with different physical properties. Al-gel elicited vascular permeability-increasing and toxic effects to macrophages (M phi), while its haemolytic effect was weak. Ca-gel elicited a significantly stronger haemolytic effect, but no other toxic effect. Incubation of M phi or polymorphonuclear leucocytes with Al-suspension resulted in the largest release of lactate dehydrogenase. Ca-suspension caused haemolysis of about 50% of that caused by Ca-gel.

Effects of pulsing electromagnetic fields on the ligament healing in rabbits.

Effects of pulsing electromagnetic fields (PEMFs) on ligament healing were investigated using 80 rabbits. All animals received square resection (4 mm x 4 mm) of both patellar ligaments in full thickness at their center. They were divided into 4 groups of 20 rabbits each and stimulated with different electromagnetic intensity of 0 (control), 2, 10, and 50 gauss (G) for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 microseconds, respectively. After PEMFs stimulations for 1, 2, 3 and 4 weeks, 5 animals of each group were euthanized and the regenerated tissue at the defective portion was investigated histologically and biomechanically. Histologically, the tissue stimulated by PEMFs showed an earlier increase in capillaries and fibroblasts and more matured, prominent longitudinal orientation of collagen fibers than those of control groups. Among the rabbits stimulated electromagnetically, those stimulated at 50 G revealed the earliest ligament healing. Tensile strength of regenerated ligament tissues of any PEMFs groups increased significantly at 1 and 2 weeks after operation, however, at 3 and 4 weeks after operation, there were no significant differences between groups. Among these values, those of 50 G group were the highest consistently during most of the experimental period. From the above results, PEMFs enhanced the earlier stage of ligament healings and 50 G gauss seemed to be the most effective among the 3 field intensities used. This promoting effect may potentiate the earlier recovery of the function after the ligament injury.

Pathological studies on local tissue reactions in guinea pigs and rats caused by four different adjuvants.

We investigated pathological changes at the injection site in guinea pigs and rats for 16 weeks following a single intramuscular injection of one of the following oil adjuvant emulsions; oil adjuvant ISA-70, Freund's incomplete adjuvant, Freund's complete adjuvant, and aluminium phosphate gel. In the animals injected with ISA-70 emulsion prepared by manual shaking, grossly, there was partial thickening of subcutaneous tissue, discoloration of inter-muscular connective tissue, and swelling of the inguinal lymph nodes at 2 and 4 weeks post injection (PI). Histopathologically, ISA-70 injected sites revealed acute inflammatory changes at 72 hrs PI, and peak reactions consisting of macrophage accumulation around oil cysts and fibrosis were observed at 4 weeks PI. These changes were less severe and of shorter duration than those in the other three adjuvants. Guinea pigs and rats injected with materials containing inactivated Newcastle disease virus (NDV) antigen similarly showed an infiltration of plasma cells and lymphocytes in addition to the changes described above. ISA-70 containing NDV antigen induced similar hemagglutination-inhibition titer to that induced by Freund's incomplete adjuvant.