In vivo properties of the conjugates of mitomycin C with estradiol benzoate and estradiol: pharmacokinetics and antitumor characteristics against P388 leukemia and sarcoma 180

Conjugates of mitomycin C (MMC) with estradiol benzoate and estradiol via glutaric acid, abbreviated to EB-glu-MMC and E-glu-MMC, respectively, as previously reported, were examined concerning their pharmacokinetic behaviors and antitumor effects against two kinds of general and popular tumors, P388 leukemia and Sarcoma 180. EB-glu-MMC and E-glu-MMC were dissolved in propylene glycol. Their solution was administered intraperitoneally to rats and mice in order to examine their plasma concentration-time profiles and antitumor characteristics, respectively. After the administration of EB-glu-MMC, EB-glu-MMC was detected slightly in blood only in the initial stage, while E-glu-MMC and MMC were observed there for a prolonged period. In the administration of E-glu-MMC, a similar phenomenon was observed but the drug retention effect seemed lower than that in EB-glu-MMC. In the antitumor test against P388 leukemia, E-glu-MMC exhibited a better effect than EB-glu-MMC; however, neither conjugate surpassed the effect of MMC. The toxic side effect was improved in each conjugate. As to the growth inhibition against Sarcoma 180, EB-glu-MMC and E-glu-MMC produced good effect and improved the toxic side effect. Especially, in the administration of EB-glu-MMC at the dose of 30 mg eq MMC/kg, a decrease in tumor volume was observed in the latter stage. EB-glu-MMC and E-glu-MMC were demonstrated to produce prolonged retention, to enter the systemic circulation to a fair extent, and to exhibit a good effect against the general solid tumor, Sarcoma 180, in vivo.     

Permanent sextupole magnets

Compact but very strong sextupole permanent magnets have been assembled for use in a newly developed cold atomic beam polarized ion source. The sextupole magnetic field characteristics have been found to be satisfactory.     

Cryopreservation of expanded mouse blastocysts by vitrification in ethylene glycol-based solutions

Experiments were conducted to find optimal conditions for obtaining high survival of expanded mouse blastocysts after vitrification. The vitrification solutions used were designated EFS20, EFS30 and EFS40, and contained 20%, 30% and 40% ethylene glycol, respectively, diluted in PB1 medium containing 30% Ficoll plus 0.5 mol sucrose l-1. In the toxicity test of the solutions and each cryoprotectant, ethylene glycol was found to be toxic to embryos. For vitrification, expanded blastocysts were exposed to the vitrification solutions at 10, 20 or 25 degrees C for various periods; they were then cooled rapidly in liquid nitrogen, after which they were warmed rapidly. When the embryos were directly exposed to EFS40 at 20 degrees C for 2 min before vitrification, 66% of them re-expanded during 48 h of post-warming culture. The re-expansion rates decreased when exposure time was shortened (0.5 min), when exposure temperature was lowered (10 degrees C), or when embryos were vitrified in EFS20 and EFS30, although these conditions should be less toxic. When embryos had been pretreated in a dilute (10-20%) ethylene glycol solution for 5 min, followed by short exposure (0.5 min) to EFS40 at 20 degrees C, post-vitrification survival rate increased to 83-84%; furthermore, the rate reached 94% when the temperature was increased to 25 degrees C. Expanded blastocysts cryopreserved by this two-step method developed into live young as well as control embryos after transfer.(ABSTRACT TRUNCATED AT 250 WORDS)     

HLA antigens are associated in seronegativity to cytomegalovirus(CMV)

The 5'-flanking region of human gamma-glutamylcysteine synthetase-heavy subunit (gamma-GCS-HS) was characterised by creating a series of chloramphenicol acetyl transferase (CAT) reporter deletion constructs. Analysis of various deleted CAT constructs revealed that a putative AP-1 consensus sequence is required to direct the constitutive and oxidant-mediated promoter activity. Gel mobility shift and mutation analysis of the sequence (-269 to -263 bp), showed binding of AP-1 is involved in the oxidant-mediated regulation of gamma-GCS-HS promoter activity.     

Carbons from furan-polymers prepared in the presence of a double-chain amphiphile

Furfuryl alcohol was polymerized in the presence of a double-chain amphiphile using malonic acid or phosphoric acid as the catalyst, leading to an aggregate of spherical particles with a long period of 2.6 nm. On calcination at 1000 °C in nitrogen gas, the polymer particles were converted into lamella-patterned carbons with a long spacing of some micrometers that are composed of carbon layers 0.4 nm in spacing. The lamella-patterned carbon particles were further developed into a highly ordered structure in an appreciable portion on calcination at 2800 °C in argon gas. The present results demonstrate that the presence of a double-chain amphiphile in the polymerization process is effective for the synthesis of such a structurally modified carbon from non-graphitizable furan polymers.     

Photocatalytic Reduction of CO2 with H2O on Ti-Containing Porous Silica Thin Film Photocatalysts

Two different Ti-containing porous silica thin films having a hexagonal and cubic pore structure were synthesized and used as photocatalysts for the reduction of CO₂ with H₂O at 323 K. UV irradiation of the Ti-containing porous silica thin films in the presence of CO₂ and H₂O led to the formation of CH₄ and CH₃OH with a high quantum yield of 0.28%. These porous silica thin film photocatalysts having a hexagonal pore structure exhibited higher reactivity than the Ti-MCM-41 powder photocatalysts with the same pore structure.     

Effect of Na-addition on catalytic activity of Pt-ZSM-5 for low-temperature NO–H2–O2 reactions

The effect of additives on Pt-ZSM-5 catalysts was studied for the selective NO reduction by H₂ in the presence of excess O₂ (NO–H₂–O₂ reaction) at 100 °C. The reaction of NO in a stream of 0.08% NO, 0.28% H₂, 10% O₂, and He balance yielded N₂ with less than 10% selectivity, which could not be increased by changing Pt loading or H₂ concentration in the gas feed. Co-impregnation of NaHCO₃ and Pt onto ZSM-5 decreased the BET surface area and the Pt dispersion. Nevertheless, the Na-loaded catalyst (Na-Pt-ZSM-5) exhibited the higher NO_x conversion (>90%) and the N₂ selectivity (ca. 50%). Such a high catalytic activity even at high Na loadings (≥10 wt.%) is completely contrast to other Na-added Pt catalyst systems reported so far. Further improvement of N₂ selectivity was attained by the post-impregnation of NaHCO₃ onto Pt-ZSM-5. In situ DRIFT measurements suggested that the addition of Na promotes the adsorption of NO as NO₂⁻-type species, which would play a role of an intermediate to yield N₂. The introduction of Lewis base to the acidic supports including ZSM-5 would be applied to the catalyst design for selective NO–H₂–O₂ reaction at low temperatures.     

Alkylation of benzene with ethane over platinum-loaded zeolite catalyst

Alkylation of benzene with ethane was carried out using various zeolite catalysts at temperature ranges of 400–550°C. Loading of platinum onto zeolite greatly enhanced the yield of ethylbenzene. Among the zeolites tested, H-ZSM5 and H-MCM22 showed catalytic activities. By contrast, mordenite did not yield ethylbenzene. Moderate acid strength distribution is the key factor of zeolite catalysts. Optimum catalyst and conditions for this reaction are as follows. The platinum-loaded H-ZSM5 catalyst containing 6.8 wt% Pt, at a reaction temperature of 500°C, afforded ethylbenzene and styrene formation rates of 14.2 and 0.8 mmolh^–1g-cat^–1, respectively (benzene-based yields 7.3 and 0.4%). In the alkylation of benzene with ethane over platinum-loaded H-ZSM5, ethene was initially formed from ethane over the metallic platinum. Then the alkylation proceeded over the acid sites of H-ZSM5.