Microsatellite polymorphism in the human heme oxygenase-1 gene promoter and its application in association studies with Alzheimer and Parkinson disease

Oxidative stress has been suggested to be involved in the pathogenesis of neurodegenerative diseases, such as Alzheimer disease (AD) and Parkinson disease (PD). Heme oxygenase-1 (HO-1), a key enzyme in heme catabolism, also functions as an antioxidant enzyme. Here, we show that a (GT)n repeat in the human HO-1 gene promoter region is highly polymorphic, although no particular alleles are associated with AD or PD. This newly identified genetic marker should allow us to study the possible involvement of HO-1 in certain human diseases.     

Electron microscopy of tRNA crystals: I. Thin crystals negatively stained with uranyl acetate

The first attempt to study crystal structures of tRNA by electron microscopy is described. Sufficiently thin crystals were prepared from yeast tRNA^phe. The thickness of the thinnest was estimated at 130 Å corresponding to a bilayer of the molecules. The L-shaped structure seemed to be maintained even after the negative staining with uranyl acetate. Optically filtered images from electron micrographs were compared with those simulated from the drawing of the molecular model by optical transform. The results suggest that the observed images reflect the real molecular arrangements within the crystal lattice although the shape of tRNA molecules seems to be somewhat modified by the uneven staining.     

The three-dimensional structure of aquaporin-1

The entry and exit of water from cells is a fundamental process of life. Recognition of the high water permeability of red blood cells led to the proposal that specialized water pores exist in the plasma membrane. Expression in Xenopus oocytes and functional studies of an erythrocyte integral membrane protein of relative molecular mass 28,000, identified it as the mercury-sensitive water channel, aquaporin-1 (AQP1). Many related proteins, all belonging to the major intrinsic protein (MIP) family, are found throughout nature. AQP1 is a homotetramer containing four independent aqueous channels. When reconstituted into lipid bilayers, the protein forms two-dimensional lattices with a unit cell containing two tetramers in opposite orientation. Here we present the three-dimensional structure of AQP1 determined at 6A resolution by cryo-electron microscopy. Each AQP1 monomer has six tilted, bilayer-spanning alpha-helices which form a right-handed bundle surrounding a central density. These results, together with functional studies, provide a model that identifies the aqueous pore in the AQP1 molecule and indicates the organization of the tetrameric complex in the membrane.     

A case of xanthogranuloma of the urinary bladder following herniorrhaphy]

We report a case of xanthogranuloma of the bladder following herniorrhaphy. The patient complained of urinary frequency, residual feeling, and presented with a solid mass located on the dome of the bladder. He had undergone previous inguinal herniorrhaphy. Transurethral biopsy revealed an inflammatory change. Partial cystectomy was carried out for en bloc removal of the tumor. The histological diagnosis was xanthogranuloma of the bladder. Postoperatively, the symptoms disappeared. This is the sixth case report of xanthogranuloma of the urinary bladder and the first case following herniorrhaphy in the Japanese literature.     

A case of a patient diagnosed with malignant mixed Müllerian tumor of the ovary who conceived after conservative surgery and adjuvant chemotherapy

A case of successful pregnancy after treatment of stage Ia malignant mixed Müllerian tumor of the ovary is described. This tumor is very rare and usually occurs in postmenopausal women. cis-platinum-based chemotherapy following the primary operation in the early stage is the most effective treatment, although most of the tumors have been found in the advanced stage. In this patient, treatment with unilateral salpingo-oophorectomy to preserve fertility was performed and followed by cis-platinum-based chemotherapy for 5 years. Two years after completion of the chemotherapy, she spontaneously conceived and the course of the pregnancy has been uneventful to this point.     

Solvent Effect in Isotope Exchange Reaction of Strontium by Liquid Chromatography using a Cryptand (2B,2,2) Polymer

Abstract

Strontium isotopes were fractionated using liquid chromatography with a cryptand (2_B,2,2) polymer as a stationary phase. In this study, we observed that the single stage isotope enrichment factor of ⁸⁴Sr shows the following order, water[6.4×10^?3]>MeOH[4.9×10^?3]>DMF[1.1×10^?3]. The enrichment factors observed in this study did not show a mass‐dependent profile, indicating that the mass‐independent isotope effect affects isotope enrichment phenomena. The mass‐dependent and the mass‐independent isotope effects that influence the enrichment factor of ⁸⁴Sr are related to the donor number linearly, implying that the solvation strongly affects the isotope effect.     

Effect of rubber compounding agent on adhesion strength between rubber and heat-assisted plasma-treated polytetrafluoroethylene (PTFE)

Although heat-assisted plasma treatment enables drastic improvement of the adhesion property of polytetrafluoroethylene (PTFE), plasma-treated PTFE does not strongly adhere to any adherend. To clarify which rubber compounding agents positively affect the adhesion strength of a plasma-treated PTFE/rubber assembly, six types of unvulcanised rubbers were prepared and thermally compressed to a plasma-treated PTFE sheet. Thus, it was found that SiO₂ addition to rubber drastically increased the adhesion strength of a plasma-treated PTFE/rubber assembly and cohesion failure of rubber occurred with large fractions of SiO₂ although no adhesives were used. To confirm the reaction between plasma-treated PTFE and SiO₂ powder, X-ray photoelectron spectroscopy (XPS) measurements were performed for the thermally compressed SiO₂/PTFE assembly after repeated washing. The XPS results indicated that hydrophilic SiO₂ powder strongly adhered to the plasma-treated PTFE, whereas hydrophobic SiO₂ powder did not adhere to the PTFE. In this paper, a model was proposed for a possible mechanism of strong adhesion of a PTFE/rubber assembly through both hydrogen and covalent bonds between silanol groups of the SiO₂ powder surface in the rubber and hydroxyl or carboxyl groups on the plasma-treated PTFE.     

Formation of C-C Bonds via Ruthenium Catalyzed Transfer Hydrogenation: Carbonyl Addition from the Alcohol or Aldehyde Oxidation Level

Under the conditions of ruthenium catalyzed transfer hydrogenation employing isopropanol as terminal reductant, π-unsaturated compounds (1,3-dienes, allenes, 1,3-enynes and alkynes) reductively couple to aldehydes to furnish products of carbonyl addition. In the absence of isopropanol, π-unsaturated compounds couple directly from the alcohol oxidation level to form identical products of carbonyl addition. Such "alcohol-unsaturate C-C couplings" enable carbonyl allylation, propargylation and vinylation from the alcohol oxidation level in the absence of stoichiometric organometallic reagents or metallic reductants. Thus, direct catalytic C-H functionalization of alcohols at the carbinol carbon is achieved.     

A 30-ns 256-Mb DRAM with a multidivided array structure

A 256-Mb DRAM with a multidivided array structure has been developed and fabricated with 0.25-μm CMOS technology. It features 30-ns access time, 16-b I/Os, and a 35-mA operating current at a 60-ns cycle time. Three key circuit technologies were used in its design: a partial cell array activation scheme for reducing power-line voltage bounce and operating current, a selective pull-up data-line architecture to increase I/O width and reduce power dissipation, and a time-sharing refresh scheme to maintain the conventional refresh period without reducing operational margin. Memory cell size was 0.72 μm². Use of the trench isolated cell transistor and the HSG cylindrical stacked capacitor cells helped reduce chip size to 333 mm²