Inhibition of benzoyl peroxide/Cu2+-dependent lipid peroxidation by manganese

1. Formation of peroxides by benxoyl peroxide (BPO) and CuCl2 was examined in the human red blood cell ghost. 2. Amounts of peroxides formed increased with the amount of the ghost solution added. 3. Of all the cations tested only manganese ion inhibited the formation of peroxides in BPO-CuCl2 reaction system. 4. The formation of peroxides was inhibited approx. 50% with 0.4 microM manganese. 5. The inhibitory manner of manganese was non-competitive against copper.     

Effects of Exogenous Amino Acids on Iron Uptake in Relation to their Effects on Photoperiodic Flowering in Lemna paucicostata 6746

The flowering of Lemna paucicostata 6746 grown on 14-h photoperiodwas enhanced by the addition of high concentrations of ironto the medium, which also increased the endogenous iron concentration.The addition of asparagine, aspartate, glutamate, -alanine,glycine or serine to the medium also increased the endogenousiron level, resulting in the promotion of flowering. In contrast,the addition of cysteine, cystine, glutamine, arginine, threonineor phenylalanine lowered the endogenous iron level, resultingin the inhibition of flowering. Glycine and asparagine added to the medium during an inductive96-h dark period did not promote iron uptake and had no effecton flowering, but when added during the subsequent 120-h lightperiod, they promoted both iron uptake and flowering response.The increase in the endogenous iron level seems to favor floraldevelopment rather than induction of photoperiodic floweringof Lemna paucicostata 6746. (Received September 8, 1986; Accepted March 31, 1987)     

Distribution and evolution of C4 syndrome inRhynchospora (Rhynchosporeae-Cyperaceae)

In order to elucidate the evolution of C₄ syndrome, the taxonomic relationships, leaf anatomy, and ecological and global distribution of C₃ and C₄ species in the genusRhynchospora were investigated. The anatomical observation for 181 species revealed that 26 C₄ species occurred within theCapitatae group of the subgenusHaplostyleae, a natural group showing highly advanced morphological characteristics, together with several C₃ species. In spite of there being rather few C₄ species, they possessed two kinds of Kranz anatomical structure differing from each other in the location of Kranz cells. Some C₃ species ofCapitatae showed radial arrangement in mesophyll cells surrounding vascular bundles, which is distinguished from typical non-Kranz anatomy. The C₄ species extended their ecological ranges from wet habitats to dry savanna grasslands, while the C₃ species showed the best development in wet habitats. The C₃ species were widespread from tropical to temperate regions with partial range extension into subarctic regions of both hemispheres, showing conspicuously high concentration of species in the New World, but being absent from arid climatic regions. The C₄ species were distributed mostly in tropics and subtropics, showing two separate distributional centers in South and Central America and in Tropical Asia and Australia. The range of C₄ species was nearly completely included in the C₃ range. In conclusion, it seems that inRhynchospora the C₄ syndrome evolved relatively recently, and arose in at least two separate phylogenetic trends in the tropics and the subtropics, more probably in the Neotropics.     

Nonsurgical collection of embryos in Shiba goats

A method of nonsurgical embryo collection in the Shiba goat, a native Japanese miniature goat breeding nonseasonally, was developed. The apparatus used for flushing the uterus was made on the model of the two-way catheter for cows. Embryo collection was performed on days 5 to 7 in 37 females superovulated with PMSG and hCG and resulted in successful recovery of 69 embryos in 19 females (51.4%). The average number of embryos collected from each successful female was 3.6. The recovery rate of embryos calculated on the basis of the number of embryos recovered and corpora lutea observed by culdoscopy in 15 successful females was 89.5%. This nonsurgical method seem to be efficient enough for collecting morulae and blastocysts in Shiba goats.     

Synthesis and conformational analysis of aib-containing peptide modelling for N-glycosylation site in N-glycoprotein

A tetrapetide containing an Aib residue, Boc-Asn-Aib-Thr-Aib-OMe, was synthesized as a peptide model for the N-glycosylation site in N-glycoproteins. Backbone conformation of the peptide and possible intramolecular interaction between the Asn and Thr side chains were elucidated by means of n.m.r. spectroscopy. Temperature dependence of NH proton chemical shift and NOE experiments showed that Boc-Asn-Aib-Thr-Aib-OMe has a tendency to form a β-turn structure with a hydrogen bond involving Thr and Aib⁴ NH groups. Incorporation of Aib residues in the peptide model promotes folding of the peptide backbone. With folded backbone conformation, carboxyamide protons of the Asn residue are not involved in hydrogen bond network, while the OH group of the Thr residue is a candidate for a hydrogen bond in DMSO-d₆ solution.     

Comparison of growth properties of carrot hairy root in various bioreactors

Summary Growth properties of carrot hairy root cells in various bioreactors were investigated. A turbine-blade reactor and an immobilized rotating drum reactor were found to be advantageous for the hairy root culture because of a high oxygen transfer coefficient (k in L a). After 30 days of culture, 10 g/l of dry hairy root cells were obtained in both bioreactors and maximum growth rates (V _m ) were found to be 0.63 and 0.61 g/l per day for the turbine-blade reactor and immobilized rotating drum reactor, respectively. Specific growth rates () at various cultivation times were observed to be linearly proportional to X/k _l a for both bioreactor configurations where X is the cell concentration. The estimated specific oxygen uptake rate of 0.34 mmol O₂/g dry cells per hour compares fairly well with an experimental value of 0.3.     

Are fluorescent bodies of Y-spermatozoa detectable in common with mammalan species?

An attempt was made to detect the fluorescent bodies (F-body), using Quinacrine mustard (Q-M) staining in the spermatozoa from eight mammalian species (human, bull, boar, dog, rabbit, rat, mouse, and mastomys) as well as in the cock (used as negative control). Sperm suspension, prepared after rinsing by repeated centrifugation with phosphate buffered saline (PBS), was either stained with Q-M for 24 h or treated with protease and then stained with Q-M for 60 min. The final concentration of Q-M in the mixed staining sperm suspension was 0.025 mg/ml. The examination using a reflecting fluorescent microscope revealed that the F-body found in human sperm was also present in the sperm of all the mammals but not in the cock after 24 h of staining. The enzyme-treated specimens showed higher incidences of F-bodies than specimens stained for 24 h without enzymatic digestion. These findings strongly suggest that the F-body is commonly present in the spermatozoa of many mammalian species.     

Production of normal piglets from microsurgically split morulae and blastocysts

The embryo splitting technique was applied to pig embryos, and the developmental ability of the split embryos was examined by means of in vitro culture and transfer. Morulae, early blastocysts and blastocysts were collected from Landrace x Large White F(1) gilts which had been mated to Duroc boars. The embryos were bisected with a fine glass or alloy (PtIr) needle after the softening of zonae pellucidae. The halved-embryos, which had either been placed in zonae pellucidae or not, were transferred to recipient gilts immediately after the micromanipulation (Experiment 1) or after cultivation for 15 to 20 h (Experiment 2). In Experiment 1, two fetuses were obtained from one of three recipients which had received 12 half-embryos. In Experiment 2, three of five recipients became pregnant, and in one recipient, seven piglets of a litter were obtained from 12 zona-free half-embryos produced from the original seven blastocysts. The results obtained indicate that a simple method not requiring the encasing of split embryos into zonae pellucidae is satisfactory to produce viable half-embryos.