Preparation of new redox-active polyionenes with porphyrin units in the main chain

Quaternization of trans-dipyridylporphyrin with 1,4-butaneditrifluoromethane-sulfonate affords new polyionenes containing porphyrin units in the main chain. The polymers exhibit chemical and electrochemical reversible redox activities. Weitz-type two-step redox processes similar to those of viologens account for the redox properties of the polymers. Received: 26 November 1996/Revised: 24 January 1997/Accepted: 10 February 1997     

Optical gating performance using a semiconductor-doped glass etalon

Optical gating is demonstrated using fast-response CdSeTe-doped glass. Continuous-wave probe light and pulsed gate light collinearly illuminate a Fabry-Perot nonlinear optical cavity consisting of two external mirrors and the doped glass. The output of the probe light is gated by the gate light with fast response time. The gating is caused by refractive-index change in the glass due to the carriers generated by the gate light. The nonlinear refractive index of the material is evaluated precisely     

The selective sorption of D,L-amino acids by chemically modified chitosan gels and its application to liquid chromatography

The sorption of D ,L -amino acids, DNP-L -amino acids and dipeptides by N-octanoyl- and N-benzoyl-chitosan gels was investigated under various conditions. The results indicate that optical resolution of D ,L -amino acids by liquid column chromatography has been achieved, using the chemically modified chitosan gels as a stationary phase.     

Preparation and characterization of porous and electrically conducting carbon-clay composites

Porous and electrically conducting carbon-clay composites were prepared by firing mixtures of carbon powder (0 to 20 wt%) and clay minerals. They showed porosity of 50 to 65% and had high mechanical strength (compressive strength = 130 to 400 kg cm^–2) as well as high resistance against thermal oxidation in air. Their electrical conductivity, , increased with increasing carbon content levelling off at about 20 wt% of carbon content to give a value of about 2 S cm^–1. Formation of carbon chains is considered to be responsible for the electrical conduction in the composite, and a model to correlate the electrical conductivity with the carbon content has been proposed by modifying a model previously proposed by Scarisbrick.     

Chemical and electrochemical preparation of poly(9,10-dihydrophenanthrene-2,7-diyl) using nickel complexes and electrochemical properties of the polymer

Summary Dehalogenation polycondensations of 2,7-dibromo-9,10-dihydrophenanthrene with isolated zero-valent nickel complex and electrochemically generated zero-valent nickel complex afford -conjugated poly(9,10-dihydrophenanthrene-2,7-diyl). The electrochemically synthesized polymer is obtained as a thin film on electrode, and shows a reversible electrochemically doping-undoping cycle in an oxidation region. The polymer has essentially the same -conjugation system as that of poly(p-phenylene).     

T134, a small-molecule CXCR4 inhibitor, has no cross-drug resistance with AMD3100, a CXCR4 antagonist with a different structure

T22, an analog of polyphemusin II (18 amino acid residues), was found to block T-tropic human immunodeficiency virus type 1 (HIV-1) entry into target cells as a CXCR4 inhibitor. We synthesized T134, a small analog (14 amino acid residues) of T22 with reduced positive charges. T134 exhibited highly potent activity and significantly less cytotoxicity in comparison to that of T22. T134 prevents the anti-CXCR4 monoclonal antibody from binding to peripheral blood mononuclear cells but has no effect on the binding of anti-CCR5 monoclonal antibodies. Since T134 inhibits the binding of stromal cell-derived factor-1 (SDF-1) to MT-4 cells, it seems that T134 prevents HIV-1 entry by binding to CXCR4. The bicyclam AMD3100 has also been shown to block HIV-1 entry via CXCR4 but not via CCR5. Both T134 and AMD3100 are CXCR4 antagonists and low-molecular-weight compounds but have different structures. Our results indicate that T134 is active against wild-type T-tropic HIV-1 strains and against AMD3100-resistant strains.     

Sorption of methyl orange by chitosan gels having hydrophobic groups

The equilibrium sorption of methyl orange by chitosan and its acyl (octanoyl, dodecanoyl, and octadecanoyl) derivatives was investigated. In general, a greater of substitution and a longer chain length increase the sorption of the dye; however, there are optimum degrees of substitution and chain length to enhance the sorptivity. The sorption isotherms were interpreted by means of a dual mechanism which comprises partition and Langmuir sorption modes.     

A low-molecular-weight inhibitor against the chemokine receptor CXCR4: a strong anti-HIV peptide T140

T22 ([Tyr5,12, Lys7]-polyphemusin II) is an 18-residue peptide amide, which has strong anti-HIV activity. T22 inhibits the T cell line-tropic (T-tropic) HIV-1 infection through its specific binding to a chemokine receptor CXCR4, which serves as a coreceptor for the entry of T-tropic HIV-1 strains. Herein, we report our finding of novel 14-residue CXCR4 inhibitors, T134 and T140, on the basis of the T22 structure. In the assays we examined, T140 showed the highest inhibitory activity against HIV-1 entry and the strongest inhibitory effect on the binding of an anti-CXCR4 monoclonal antibody (12G5) to CXCR4 among all the CXCR4 inhibitors that have been reported up to now.     

Low Serum Parathyroid Hormone Is a Predictor of Early Death after Hip Arthroplasty in Hemodialysis Patients

Background and Purpose:  Colloid osmotic pressure (COP) in plasma rises by ultrafiltration during hemodialysis, and it consequently causes plasma refilling in which water moves from interstitial tissue to capillary space. Although hemodynamic stability is one of the important factors for good dialysis outcome, no informative and convenient indicators are available other than monitoring of blood pressure. Thus, we measured COP during hemodialysis whether COP can be used as an indicator for the hemodynamic status in comparison with hematocrit (Ht). Plasma osmolality, ultrafiltration volume, and the alteration of blood pressure were also measured to examine whether COP is associated with them.
Method:  Sixteen patients hospitalized in this hospital were examined. Amongst them, 10 patients underwent both dialysis and ultrafiltration, while 4 patients received only dialysis and 2 patients were with ultrafiltration only by extracorporeal ultrafiltration method. Ultrafiltration was performed with constant speed to the dry weight for 4 h. The measurements of COP, plasma osmolality, Ht levels, and blood pressure were performed at 30 min (12.5% of the total water removal), 1 h (25%), 2 h (50%), and 3 h (75%) after the start of hemodialysis and also at the end of dialysis (100%).
Result:  COP markedly rose by 26.0% (±13.3%) in the patients who received both dialysis and ultrafiltration, whereas Ht rose by only 13.6% (±5.21%). And the curve for COP increase was sigmoid shape, whereas that for Ht showed linear change. On the other hand, in the patients whose Ht levels showed low values, the curves for both COP and Ht showed similar pattern.
Conclusion:  These results suggest that COP is a more sensitive indicator to be monitored for the hemodynamic status than Ht during hemodialysis.