Dopamine D3 receptor gene polymorphism and the psychiatric symptoms seen in first-break schizophrenic patients

Cycads, the most primitive of the living gymnosperms, have been used and continue to be used for food and medicinal purposes by many cultures, although toxins must be removed before ingestion. In our quest to identify tropical plants that contain inhibitors of the cytochrome P-450 aromatase and thus may be efficacious in treating estrogen-dependent tumors, we have screened extracts from 5 species of cycad folia encompassing 3 genera: Cycas cairnsiana F. Muell., Cycas revoluta Thunb., Cycas rumphii Miq., Dioon spinulosum Dyer and Encephalartos ferox Bertol. All extracts were found to contain inhibitors of the human enzyme.     

Lack of point mutation of the APP gene in sporadic Alzheimer's disease in Japanese

We investigated point mutations of the APP gene in 66 patients with sporadic Alzheimer's disease (AD) and 180 normal individuals by use of the PCR (polymerase chain reaction) method. Both the AD patients and the normal individuals were Japanese. We extracted DNA from blood samples using the phenol-chloroform method and amplified exons 16 and 17 of the APP gene by PCR. PCR products were digested by MBO-II (exon 16) and BCL-1(exon 17). Electrophoresis was carried out with 3% agarose gel and the separated fragments were stained with ethidium bromide. In addition we investigated other point mutations of exons 16 and 17 by use of the PCR-SSCP (single stranded conformation polymorphisms) method, and found no fragments that exhibited point mutations in the AD patients and normal individuals. These findings indicate that the presence of point mutation of the APP gene is not a major cause of AD in the Japanese population.     

Pulsed electron-beam annealing of phosphorus-implanted silicon

Electrical properties of phosphorus-implanted silicon annealed by a single shot of a high-power pulsed electron beam have been studied by differential Hall-effect and sheet-resistivity measurements. Nearly 100% electrical activation of implanted phosphorus can be obtained after electron-beam annealing at an incident energy density of 0.92 J/cm2. Uniformly distributed carrier concentration profiles have been formed by electron-beam annealing.     

Silicone-clad fused-silica-core fibre

We have developed a very-low-loss optical fibre employing silicone resin as the cladding and fused silica as the core. The minimum transmission loss was 3.2 dB/km at 0.84 ?m and the half-pulse width spread was 19 ns/km at 0.80 ?m.     

Recent progress in fiber fabrication techniques by vapor-phase axial deposition

Five years have passed since the invention of the VAD technique. Fabrication techniques for the various kinds of VAD fibers such as graded index fibers, single-mode fibers, high NA fibers, and single polarization fibers have been developed. This paper mainly outlines the recent improvements in the VAD fiber manufacturing techniques such as the preform fabrication technique, dehydration technique, refractive index profile formation technique, and the single-mode fiber manufacturing technique.     

Nonpeptide angiotensin II receptor antagonists. Synthesis and biological activity of potential prodrugs of benzimidazole-7-carboxylic acids

In order to improve the oral bioavailability (BA) of 2-butyl-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimid azole - 7-carboxylic acid (3: CV-11194) and 2-ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4- yl]methyl]-1H-benzimidazole-7-carboxylic acid (4: CV-11974), novel angiotensin II (AII) receptor antagonists, chemical modification to yield prodrugs has been examined. After selective tritylation of the tetrazole rings in 3 and 4, treatment of N-tritylated benzimidazole-7-carboxylic acids (6, 7) with a variety of alkyl halides, followed by deprotection with hydrochloric acid, afforded esters of 3 and 4. Mainly 1-(acyloxy)alkyl esters and 1-[(alkoxycarbonyl)oxy]alkyl esters, double ester derivatives, were synthesized. Their inhibitory effect on AII-induced pressor response in rats and oral BA were investigated. (Pivaloyloxy)methyl and (+/-)-1-[[(cyclohexyloxy)-carbonyl]oxy]ethyl esters of 3 and 4 showed marked increases in oral bioavailability which significantly potentiated the inhibitory effect of the parent compounds on AII-induced pressor response. Among them, (+/-)-1-[[(cyclohexyloxy)carbonyl]oxy]ethyl 2- ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimida zole- 7-carboxylate (10s, TCV-116) was selected as a candidate for clinical evaluation.     

Effects of free radical scavengers on cytokine actions on islet cells

We investigated the effect of free radical scavengers on the actions of cytokines on islet cells. Interferon-gamma and tumor necrosis factor-alpha reduced the nicotinamide adenine dinucleotide content of mouse islet cells; the combination of interferon-gamma (4 x 10(5) U/l) and tumor necrosis factor-alpha (4 x 10(5) U/l) caused nicotinamide adenine dinucleotide reduction by approximately 40%. Dimethyl urea and dimethyl sulfoxide prevented the decrease, whereas superoxide dismutase, catalase, and mannitol were not effective. Dimethyl urea and dimethyl sulfoxide protected islet cells from the synergistic cytotoxic action of interferon-gamma and tumor necrosis factor-alpha. Major histocompatibility complex class II antigen induction by interferon-gamma and tumor necrosis factor-alpha was also inhibited by dimethyl urea and dimethyl sulfoxide, but not by superoxide dismutase, catalase and mannitol. Since superoxide dismutase of a membrane-penetrable form attenuated the class II antigen induction, the inefficiency of superoxide dismutase, catalase and mannitol may be attributable to their inability to penetrate islet cells. These results suggest that the intracellular generation of free oxygen radicals is involved in islet cell cytotoxicity and class II molecule expression by interferon-gamma and tumor necrosis factor-alpha, and that nicotinamide adenine dinucleotide reduction may be associated with islet cell dysfunction caused by the cytokines.