Excitotoxicity-induced immediate surge in hippocampal prostanoid production has latent effects that promote chronic progressive neuronal death

Excitotoxicity is involved in neurodegenerative conditions. We investigated the pathological significance of a surge in prostaglandin production immediately after kainic acid (KA) administration [initial phase], followed by a sustained moderate elevation in prostaglandin level [late phase] in the hippocampus of juvenile rats. Numerous pyknotic hippocampal neurons were observed 72 h after KA treatment; this number remained elevated on days 10 and 30. Gross hippocampal atrophy was observed on days 10 and 30. Pre-treatment with indomethacin ameliorated neuronal death on days 10 and 30, and prevented hippocampal atrophy on day 30. Microglial response was moderated by the indomethacin pre-treatment. Blockade of only late-phase prostaglandin production by post-treatment with indomethacin ameliorated neuronal death on day 30. These findings suggest a role for initial-phase prostaglandin production in chronic progressive neuronal death, which is exacerbated by late-phase prostaglandin production. Blockade of prostaglandin production has therapeutic implications in preventing long-term neurological sequelae following excitotoxic brain damage.     

The Formation of Higher Alcohols in the Fermentation of Amino Acids by Yeast

We have found that some straight-chained α-amino acids are converted by yeast to the alcohols with correspondingly longer carbon chains in the alcoholic fermentation contrary to F. Ehrlich’s scheme, i.e., isobutyl alcohol from alanine and active amyl alcohol from α-amino-n-butyric acid or threonine.

In this report, we confirmed this fact in the alcoholic fermentation of many aliphatic amino acids by 2 yeast strains using gas chromatography. Moreover, n-propyl alcohol was proved to come from α-amino-n-butyric acid or threonine. Small quantities of n-propyl, isobutyl, active amyl and isoamyl alcohols were found in all the fermented solutions. There was some difference in the composition of higher alcohols of the alcoholic solutions fermented by different yeasts.     

Metabolism of 2,4,4′-Trichlorobiphenyl by Acinetobacter sp. P6

Metabolism of 2,4,4′-trichlorobiphenyl by Acinetobacter sp. strain P6 has been studied. When the incubation was carried out without shaking at 15°C, two isomeric monohydroxy compounds, a dihydrodiol compound, a dihydroxy compound, a meta-cleaved yellow compound and a dichlorobenzoic acid were detected by combined gas liquid chromatograph-mass spectrometry. As an additional metabolite, dichlorodihydroxy biphenyl, a dechlorinationhydroxylation product, was also detected. When the incubation mixture was shaken at 30°C, a meta-cleaved yellow compound was readily produced and predominantly accumulated in the reaction mixture upon further incubation. The major pathway of 2,4,4′-trichlorobiphenyl by Acinetobacter sp. P6 was considered to proceed oxidatively via 2.′3′-dihydro-2′,3′-diol compound, concomitant dehydrogenated 2′,3′-dihydroxy compound and then the 1′,2′-meta-cleaved yellow compound, i.e., 3-chloro-2-hydroxy-6-oxo-6(2,4-dichlorophenyl)hexa-2,4-dienoic acid.     

Isolation of Allo-isoleucic Acid (α-Hydroxy-β-methylvaleric Acid) and β-Hydroxy-β-methylvaleric Acid from Turkish Tobacco Leaves

A new method determining the activity of tannin acyl hydrolase (tannase) was made. This method was based on the change in optical density of substrate tannic acid at 310 mμ. In this method, the error of measurement was about 1~3%, and many samples could be tested at one time because of its simplicity.

The procedure was as follows; To four parts of substrate (0.350 w/v% of tannic acid dissolved in 0.05m citrate buffer, pH 5.5), one part of the enzyme solution was added.

After t minutes reaction at 30°C, 0.1 part of the mixture was added to ten parts of 90% ethanol.

The optical density of the ethanol solution at 310 mμ was measured. Tannase activity (unit/ml) was given by following equation. $u=114\times \frac{E_{t1}?E_{t2}}{t_2?t_1}$

Where E_t1 and E_t2 mean the optical density of the ethanol solution at 310 mμ prepared after t₁ and t₂ minutes reaction, and one unit of the enzyme means the amount of the enzyme which is able to hydrolyze one μ mole of the ester bond in tannic acid in one minute.

The substrate tannic acid used in this determining method was purified. It was composed of one mole of glucose and nine moles of gallic acid, and eight moles of which formed four moles of m-digallic acid.     

A Stereoselective Synthesis of Antimycinone A3 and Its Stereoisomers

Antimycinone A₃, which is a neutral fragment of mild alkaline hydrolysate of antimycin A₃, and its stereoisomers were synthesized stereoselectively from methyl trans-2-n-butylpent-3-enoate or methyl cis-2-n-butylpent-3-enoate, and natural antimycinone A₃ was proved to possess Hα-Hβ and Hβ-Hγ trans configuration.     

Studies on the Fermentative Production and Metabolism of Uridine Coenzymes

Enzyme activities involved in the galactose metabolism of Torulopsis Candida grown on a. lactose medium were investigated with the cell-free extract and ammonium sulfate fraction. Remarkable activities of galactokinase, galactose-1-phosphate uridylyltransferase and UDPG pyrophosphorylase were detected, whereas UDPGal pyrophosphorylase activity was weak. UDPGal formation proceeded by the cell-free extract along a coupling reaction catalyzed by UDPG pyrophosphorylase and galactose-1-phosphate uridylyltransferase where UDPG or glucose-l-phosphate acted as a catalyst.

The mechanism of UDPGal accumulation under the fermentative condition could be explained by a concerted inhibition of UDPGal-4- epimerase activity by 5′-UMP and galactose present as fermentation substrates.     

Growth-Promoting Factors for Lactobacillus bifidus var. pennsylvanicus Produced by the Amino-Carbonyl Reaction of l-Lysine and d-Glucose

l-Lysine monohydrochloride and d-glucose were allowed to react in a bicarbonate buffer of pH 8.8 under refluxing. The reaction mixture was then chromatographed on a thin-layer plate of Kiesel Gel using n-propanol ethyl-acetate water 25% aqueous ammonia (6: 1: 2: 1 v/v) as a developing agent. Elson-Morgan-reactive spots on the chromatogram were eluted individually, and each of the eluates was incubated with L. bifidus var. pennsylvanicus in a defined medium. A certain fraction on the chromatogram showed remarkably promoting effect on both the acid productivity and the growth of the organism. And such effect of the fraction was much stronger than that of N-acetyl-d-glucosamine which had been known as a “Bifidus Factor”     

δ-Hydroxylysine,Canavanine and Three α-Amino Acid Amides from Ladino Clover Seed (Trifolium repens L. var. giganteum)

The antibacterial effects of salivary nitrate/nitrite on the growth of three Desulfovibrio species were examined. The bacteria did not grow on plates with ≥0.2 mM nitrate or ≥1.0 mM nitrite. They were also incubated in filter-sterilized saliva. D. desulfuricans was reduced on the order of >10² compared with the control solution (phosphate-buffered saline) in nine out of the 10 participants.