Platelet-activating factor. Evidence for 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine as the active component (a new class of lipid chemical mediators).

A glyceryl ether containing phosphoglyceride, 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (Ac-GEPC), has been shown to have a biological activity indistinguishable from that of naturally generated (rabbit) platelet activating factor (PAF). Its biochemical and biological properties so closely parallel those of naturally occurring PAF that we propose they are one and the same compound. Both PAF and AcGEPC could be converted to an inactive form through base-catalyzed methanolysis and restored to 100% functional activity by reaction with acetic anhydride. The synthetic lipid, AcGEPC, elicited 50% secretion of serotonin from rabbit platelets at a level of 10(-10) M (based on phosphorus). A propionyl derivative had somewhat comparable activity towards platelets, whereas the butyryl homologue was some 7-fold less active and the stearoyl derivative was inactive. These short chain acylglyceryl ether phosphoglycerides represent an entirely new, potent and unique class of lipid chemical mediators. 1-Acyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (AcLL) also exhibited activity towards platelets but was some 200-fold less active than AcGepc. the propionyl lysolecithin behaved quite similarly to AcLL, but butyryl and stearoyl lysolecithins showed no activity.     

Lipids of Pinus halepensis pollen

The total lipids of Pinus halepensis pollen were separated into individual classes of neutral and polar lipids and the components of each class were identified and determined quantitatively. Free fatty acids, waxes and triacylglycerols were found as the main constituents of neutral lipids and phosphatidylcholine and phosphatidylethanolamine of polar lipids. Glycerylether derivatives were detected in neutral and polar lipid fractions. Free and esterified volatile fatty acids were also found in pollen and its neutral lipid fraction.     

Production of DON-related trichothecenes byFusarium graminearum Schw from Krasnodarski krai of the USSR

34Fusarium graminearum Schw isolates produced 4-deoxynivalenol to form significant amounts of 4, 7 — dideoxynivalenol and lesser amounts of 4 — deoxynivalenol monoacetates on grain substratesin vitro. This is the first report on the capability a large group of naturally occurring isolates to produce 4,7-dideoxynivalenol. The average levels of 4,7-dideoxynivalenol on rice, corn, barley, and wheat as a substrate were respectively 26.8, 14.0, 12.8, and 10.5% of the level of 4-deoxynivalenol. 4, 7 — dideoxynivalenol was present in all examined naturally contaminated wheat kernel samples at levels of 1.7 to 7.9% of the level of 4-deoxynivalenol. These findings suggest that more attention should be given to the occurrence of 4,7-dideoxynivalenol in cereals.     

Variation in the ribosomal internal transcribed spacers (ITS1 and ITS2) among eight taxa of the Mimulus guttatus species complex

The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA sequence and the intervening 5.8S region were sequenced from three individuals in each of eight taxa of the Mimulus guttatus species complex. Three discrete variants, or "types," of ITS sequences were found, among which 30%-40% of sites differed, compared with 1%-2% within types. Dot plots indicate that these types were not related by conspicuous rearrangements or inversions. More than one ITS type was often found in the same taxon, and two of three ITS types span species boundaries, indicating their presence prior to speciation. These ITS sequences showed essentially no positional homology with the nearest sequenced relative, tomato. In contrast, the 5.8S region was relatively unvaried, with 8 of 162 sites varied in the sample among all eight taxa. The phylogeny inferred by the most common ITS sequence type, rooted by the two other ITS types, agreed with isozymes in showing the distinctness of M. nudatus, M. laciniatus, and M. tilingii from the other five taxa.      

Spontaneous generation of adriamycin semiquinone radicals at physiologic pH.

Adriamycin semiquinone radicals are spontaneously generated by adriamycin solutions at physiologic pH. Rate of radical formation and equilibrium-state radical yield increase with increasing pH from 7.4 to 8.85. The radicals are oxygen sensitive, but the mechanism of radical formation is oxygen independent and associated with proton removal from the dihydroquinone of adriamycin. The less cardiotoxic and non-mutagenic (Ames test) anthracycline 5-iminodaunorubicin does not form semiquinone radicals spontaneously at physiologic pH.     

Altered protein synthesis rate in ovaries of D. melanogaster caused by new antitumour alkylating agents.

1. The effect of two homo-aza-steroidal esters with antineoplastic activity, namely 3 beta-hydroxy-13 alpha-amino-13,17-seco-5 alpha-androstan-17-oic-13,17-lactam-p-bis(2-chloroethyl)aminoph enoxyacetate (NSC 294859) and 3 beta-hydroxy-13 alpha-amino-13,17-seco-5 alpha-androstan-17-oic-13,17-lactam-p-bis(2-chloroethyl)aminoph enylacetate (ASE) on protein synthesis rate was studied in ovaries of Drosophila melanogaster females. 2. Two different concentrations for each compound were examined. 3. Both esters containing the same alkylating agent have been shown to decrease protein synthesis in relation to control.     

Use of a rapid DNA sequencing system to demonstrate the induction of frameshift mutations by bleomycin

The rapid DNA sequencing system based on the single-stranded bacteriophage M13 and the chain-terminator method has been used to look directly for mutational alterations. A small DNA fragment that primes DNA synthesis through the N-terminal 200 base pairs of the beta-galactosidase gene was prepared, and used to detect changes in base sequence among phages that give white plaques after treatment of the host cells with bleomycin. Bleomycin treatment of E. coli in which M13 mp2 was growing gave an increase in white plaque frequency. DNA sequence analysis of phage from 7 independent mutant plaques showed them all to have a frameshift mutation.     

中国小菇属十个新记录种

报道了小菇科小菇属真菌10个中国新记录种,香菌组：橙盖小菇Mycena aurantiidisca、黄白小菇Mycena flavoalba、粉黄小菇Mycena floridula;棘刺组：异刺小菇Mycena heteracantha;纤柄组：碱味小菇Mycena amygdalina;脆足组：粉被小菇Mycena zephirus;冬生组：绣线菊小菇Mycena speirea、冬生小菇Mycena hiemalis;小菇组：绒柄小菇Mycena flos-nivium,分别来自吉林等11个省份、自治区。提供了每个物种的形态描述和线条图,以及与相近种的讨论。共计90条自测及下载ITS序列,在采用贝叶斯法和最大似然法构建的小菇属系统发育树中,新记录种均得到分子数据支持。凭证标本存放于吉林农业大学菌物标本馆（HMJAU）。