Permutation of the DNA in small-headed virions of coliphage P1

Summary Use of restriction endonucleases BglII, EcoRI, BamHI, and HindIII, has established that in small-headed (PIS) virions of coliphage P1, as a population, the entire genome found in big-headed (P1B) virions is represented. In addition, the origin and direction of DNA packaging are identical in P1S and P1B virions.     

(+)-5,17-dehydromatrine N-oxide,a new alkaloid in Euchresta japonica

A new lupin alkaloid, (+)-5,17-dehydromatrine N-oxide, was isolated from the fresh aerial parts of Euchresta japonica. Its structure was confirmed by spectrometric data and by direct comparison with a synthetic sample, prepared from (+)-sophoranol ((+)-5-hydroxymatrine). It was also concluded that (+)-5,17-dehydromatrine N-oxide and (+)-matrine N-oxide possess the same configuration with respect to the asymmetric nitrogen by NMR spectra.     

Oxidation and reduction of plastoquinone by photosynthetic and respiratory electron transport in a cyanobacterium Synechococcus sp.

The I-D dip, an early transient of the fluorescence induction, was examined as a means to monitor redox changes of plastoquinone in cells of a cyanobacterium, Synechococcus sp. That the occurrence of the dip depends upon the reduced state of the plastoquinone pool was indicated by observations that 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone and 3-(3,4-dichlorophenyl)-1,1-dimethylurea did not affect the initial rise to I but abolished the subsequent decline from I to D and that illumination of the cells with light 1, prior to fluorescence measurements, eliminated the transient. The I-D dip was prominent in freshly harvested cells containing abundant endogenous substrates, disappeared slowly as the cells were starved by aeration but reappeared on addition of fructose to the starved cells in the dark. The dip that had been induced by a brief illumination of the starved cells with light 2 was rapidly diminished in the dark and KCN inhibited the dark decay of the transient. The results indicate that plastoquinone is reduced with endogenous as well as exogenous substrates and oxidized by a KCN-sensitive oxidase in the dark, thus providing strong support for the view that plastoquinone of photosynthetic electron transport also functions in respiration. In addition, the occurrence of a cyclic pathway of electrons from Photosystem I to plastoquinone, possibly via ferredoxin or NADP, was suggested. Several lines of evidence indicate that, under a strong light 2, Photosystem I-dependent oxidation of plastoquinone predominates over Photosystem II-dependent reduction of the quinone in the cyanobacterium which contains Photosystem I more abundantly than Photosystem II.     

Enhanced activity of deoxyuridine 5′-triphosphatase in regenerating rat liver

An enzyme, dUTPase, that catalyzes the conversion of dUTP to dUMP and PPi, was partially purified from regenerating rat livers. The molecular weight was estimated by gel filtration to be 60,000. The apparent Km for dUTP was 12 μM. No other deoxyribonucleoside triphosphates served as a substrate. This enzyme is active in the absence of added divalent cations or sulfhydryl reagents; the activity could be inhibited by EDTA and shows a broad pH optimum with no decrease in activity from pH 7 to 11. The specific activity of dUTPase in rat liver begins to rise 16 h after partial hepatectomy and reaches a maximum about 24 h after the operation, rising to at least 5 to 6 times the normal level.     

Ejaculations induced by p-chloroamphetamine (PCA) in rats, hamsters and mice.

The ejaculatory response induced by p-chloroamphetamine (PCA) in male rats, hamsters and mice was observed during 2 hours after the injection. The animals were treated intraperitoneally with PCA at doses ranging from 0.78125 to 160 mg/kg. The ED50 (effective dose in 50% of animals) values of PCA for the initiation of ejaculation in rats and hamsters were 1.3397 (1.0732-1.6725) and 0.1105 (0.0802-0.1522) mg/kg, respectively. On the other hand, no ejaculation was observed in any mice at any doses examined. So we concluded that there are species differences in the ejaculatory response, induced by PCA, among rats, hamsters and mice.     

Pre- and post-implantation losses of embryos in aging female IVCS mice

Mated female mice of the IVCS strain, aged 90 (control group), 180, 210, 240, 270, 300, 330, 360 and 420 days old, were studied for pre- and post-implantation loss of embryos. The percentage of pre-implantation loss in mice aged 90 to 210 days was 1.7/11.8 (14.4%) to 2.7/11.7 (23.1%). In mice aged 240 to 300 days it increased significantly as compared to the controls (46.5-90.2% versus 14.4%). It reached 100% in 300-days-old mice. The post-implantation loss of embryos and/or fetuses in mice aged 90 to 240 days was 1.0/10.2 (9.8%) to 2.5/9.0 (27.8%). In mice aged 270 to 300 days it increased significantly compared to the controls (100% versus 9.8%). The decrease in reproductive activity appeared first in a decrease in litter size, followed by a decrease in the number of blastocyst and implantation sites, and finally by anovulation during the process of aging in IVCS mice.     

Central effects of yohimbine on copulatory behavior in aged male rats

It is well known that yohimbine has a history of popular use because of its supposed aphrodisiac properties. The present study was done to determine whether yohimbine can modify the copulatory behavior of aged male rats. Adult male rats of the Wistar-Imamichi strain, 52 weeks of age and weighing 600-650g, were injected intracerebroventricularly with yohimbine hydrochloride (5, 10 micrograms/10 microliters/rat) or vehicle. Each male was then given the opportunity to mate with a receptive female for 30 min after administration of yohimbine or vehicle. Yohimbine produced significant decreases in the latency to initial mounting and significant increases in the number of mountings. However, there was no ejaculation in the yohimbine-and vehicle-treated males. This study is the first to clearly establish an important modulator of sexual arousal for yohimbine in aged male rats.     

Chlorination of cellulose with N-chlorosuccinimide-triphenylphosphine under homogeneous conditions in lithium chloride-N,N-dimethylacetamide.

Microcrystalline cellulose was chlorinated with N-chlorosuccinimide-triphenylphosphine under homogeneous conditions in LiCl-N,N-dimethylacetamide. At the early stage of the reaction only replacement of the 6-hydroxyl groups with chlorine was observed, and 3-hydroxyl groups were replaced at a lower rate with Walden inversion. The effects of reaction conditions on the extent of chlorination were studied in detail. More than two equivalents of chlorination reagents per glucose residue were necessary to attain a high degree of substitution (ds) by chlorine, and the maximum ds attained was 1.86. Chlorinated disaccharides were found in the hydrolyzates of chlorodeoxycelluloses hydrolyzed under mild conditions, and their structures were studied by mass spectrometry.