Preparation of polyaniline by oxidation of aniline using H2O2 in the presence of an iron(II) catalyst

Oxidative polymerization of aniline using the H₂O₂-FeSO₄ system gave polyaniline under mild conditions. The prepared powdery emeraldine base, a form of polyaniline, is blue black and shows high solubility in organic solvents (e.g., ca. 200 mg/mL in N-methylpyrrolidone). The number-average molecular weight (M _n) of the polymer obtained was 1,3–1,7 · 10⁴ (via gel permeation chromatography vs. polystyrene) and M _w/M _n = 1,6–2,2. Poly(2-ethylaniline) and poly-(2-propylaniline) with high molecular weights were also synthesized by this procedure in high yield.     

Raman spectroscopic study of hydrogen bonding of poly(N-vinyl-2-pyrrolidone) in heavy water and dimethyl sulfoxide

The Raman spectra of solutions of poly(N-vinyl-2-pyrrolidone) (PVP; M?_w = 1 000, 10 000, 40 000 and 360 000) in D₂O and dimethyl sulfoxide (DMSO) were measured at various concentrations. PVP is hydrated by D₂O in a manner different from N-ethyl-2-pyrrolidone (NEP) and N-methyl-2-pyrrolidone (NMP), monomer analogues of PVP. The self-association of DMSO molecules in the solution of PVP was found to be different from that in the solution of NMP by using difference spectroscopy. These phenomena were attributed to a net-like structure of concentrated solutions of PVP.     

Use of a high-throughput umu-microplate test system for rapid detection of genotoxicity produced by mutagenic carcinogens and airborne particulate matter

In the present study, we developed a rapid umu-microplate test system that uses the nitroreductase- and O-acetyltransferase-overproducing Salmonella typhimurium strain NM3009 and the O-acetyltransferase-overproducing S. typhimurium strain NM2009 to detect genotoxic activity in small volume samples. The assay was used to test the genotoxicity of several standard mutagens and environmental samples. Exponentially growing cultures of NM3009, NM2009, and the parental strain TA1535/pSK1002 were incubated in 96-well microplates with test chemicals both in the presence and in the absence of rat liver S9. The relative beta-galactosidase activities were then determined colorimetrically using either chlorophenol red-beta-D-galactopyranoside (CPRG) or O-nitrophenyl-beta-D-galactopyranoside (ONPG) as a measure of umuC gene induction activity. The sensitivities of NM3009 without S9 mix and NM2009 with S9 mix to nitroarenes and aromatic amines were up to 24- to 75-fold higher than those of the parent strain. Induction of umuC gene expression was detected more readily with CPRG than ONPG. The umu-microplate assay also detected genotoxicity in organic extracts of particulate matter from air samples collected in Osaka City, Japan. The pattern of the responses suggested that the genotoxic activity of the particulate extract was due primarily to nitrated polycyclic aromatic hydrocarbons. Our results indicate that the umu-microplate assay may be a useful way of carrying out rapid screens for genotoxicity in small-volume environmental samples.     

Interleukin-3-dependent potentiation of IgE responsiveness in mouse basophils

Basophils produce interleukins (IL)-4 in response to various stimuli and may contribute to type 2 immune responses to various infections and allergens. We found that resting basophils freshly isolated from mice produce IL-4 in response to IL-3 but not to high-affinity Fc receptor (FcεRI) cross-linking (CL), yet both required the immunoreceptor tyrosine-based activation motif (ITAM) containing adaptor Fc receptor γ-chain (FcRγ), while basophils activated in vitro by IL-3 become responsive to FcεRI CL. Acquisition of responsiveness to FcεRI CL occurred upon infection with Trichinella spiralis or administration of superantigen. Because cultured basophils return to a quiescent state upon starvation with IL-3 with surface FcεRI levels unchanged, this acquisition is reversible and probably reflects intracellular events requiring protein synthesis. Interestingly, similar activation-associated acquisition was observed for responsiveness to other stimuli, including CD200R3 CL, which is known to signal via DAP-12, and the allergen protease papain. This acquisition of responsiveness to FcεRI CL was inhibited by Jak inhibitor. Thus, the IL-3 signal bifurcates downstream of Jak, into two distinct pathway, one leading to IL-4 production and the other to render basophils competent to respond to stimuli dependent on ITAM-containing adaptors DAP12 and FcRγ for IL-4 production.     

Risk estimation for hypertension based on follow-up health examination data in a small village in Kumamoto prefecture, Japan

The estimation of risk for incidence of hypertension was carried out by follow-up study in a small village in Kumamoto Prefecture, Japan (N=750, 48.2±15.2months). The most significant risk in both sexes was blood pressure at entry. As for other risks, age, total cholesterol, and BMI in females were significant risks for systolic and diastolic blood pressure changes to greater than the borderline level. These factors in males were not significant. From the results of analysis using Cox's proportional hazards model, drinking in males was shown to be a significant risk for diastolic change, and in females for systolic change. It was concluded that excessive drinking in both sexes and obesity in females led to important health problems associated with hypertension among the subjects of the study.     

The effect of adenosine on cochlear potentials in the guinea pig

The effect of adenosine on cochlear potentials was examined in the guinea pig. Perilymphatic perfusion with 10^–4 M adenosine produced a significant decrease in the amplitudes of cochlear microphonics, negative summating potential (-SP) and compound action potential (CAP) and significant prolongation of N1 latency with no change in the endocochlear potential. The decreases in the amplitudes of -SP and CAP caused by adenosine were dose-dependent. Perilymphatic perfusion with an inactive analogue, 8-bromoadenosine, produced no changes in the cochlear potentials. The A1-receptor agonist, 2-chloroadenosine, produced a similar change in cochlear potentials to adenosine, while no changes were produced by the A2-receptor agonist ,5-(N-ethylcarboxamido)-adenosine. These results suggest that adenosine may have a modulatory function through an Al receptor in the cochlea.     

Differences in the effect of iron-deficient diet on tissue weight, hemoglobin concentration and serum triglycerides in Fischer-344, Sprague-Dawley and Wistar rats.

This study was designed to examine the differences in the effect of an iron-deficient diet on iron metabolism in Fischer-344 (FC), Sprague-Dawley (SD) and Wistar (WT) rats based on hemoglobin (Hb), hematocrit (Hct), serum iron levels, growth rate and organ weight. Hb concentration was higher in FC rats (14 mg/100 mL) on the initial day than in SD (10) and WT (10) rats. Although the Hb level was significantly decreased in FC rats fed an iron-deficient (ID, 8 mg/kg) diet for 33 d compared to the FC rats fed an iron-adequate (IA, 50 mg/kg) diet, the relative concentration of Hb was high in FC rats fed the ID diet as compared to the SD and WT rats fed the same diet. A similar relationship was detected between Hct and serum iron concentrations. Although serum triglycerides (TG) were significantly increased in each rat strain fed the ID diet as compared to the IA diet, the percentage of the value for the IA diet was lowest in FC rats (119%) fed the ID diet as compared to the SD (328) and WT (394) rats fed the same diet. Retroperitoneal fat pad was decreased in FC, SD and WT rats fed the ID diet as compared to the IA diet. SD rats were particularly sensitive to the reduction of retroperitoneal fat pad. The results suggested that rat strains responded differently to dietary iron inadequacy, and that FC rats were less sensitive to an iron-deficient diet as compared to the SD and WT rats.