Genomic investigation of phenotypic variation in Campylobacter jejuni flagellin.

Western blots of whole-cell sonicates of 10 different clones of a faecal isolate of Campylobacter jejuni 533 detected the expression of flagella antigens of either 59 or 62 kDa. Other antigenic proteins appeared identical both in the parent and all the clones. The mechanism for this phenotypic variation was studied using Southern blotting with a flagellin-specific gene probe and products of a polymerase chain reaction (PCR) using flagellin-gene primers. Restriction-enzyme digestion and Southern blotting did not detect any genomic rearrangements in the flagellin genes of the different phenotypes nor did restriction-enzyme analysis of the PCR products.     

Mechanism of inhibition of peptide chain initiation by amino acid deprivation in perfused rat liver. Regulation involving inhibition of eukaryotic initiation factor 2 alpha phosphatase activity.

In previous studies, initiation of protein synthesis was shown to be inhibited in perfused rat livers deprived of single essential amino acids. In the present study, histidinol, a competitive inhibitor of histidinyl-tRNA synthetase, was used to amplify the effects of histidine deprivation on protein synthesis in perfused liver to facilitate investigation of mechanisms involved in the inhibition of peptide chain initiation. Protein synthesis was reduced to 77% of the control rate in livers deprived of histidine and to 13% of the control rate in livers deprived of histidine and exposed to 2.0 mM histidinol. The inhibition of protein synthesis caused by histidine deprivation alone was accompanied by a 2-fold increase in the number of free ribosomal particles, a 29% decrease in Met-tRNA(i) binding to 43 S preinitiation complexes, and a 31% reduction in activity of eukaryotic initiation factor 2B (eIF-2B). By comparison, histidine deprivation combined with histidinol addition resulted in a 3-fold increase in free ribosomal particles, a 66% decrease in Met-tRNAi binding, and a 78% reduction in eIF-2B activity. The proportion of the alpha-subunit of eukaryotic initiation factor two (eIF-2) in the phosphorylated form increased from 8.9 +/- 0.8% in control livers to 52.4 +/- 5.5% in response to histidinol. The increase in the amount of eIF-2 alpha in the phosphorylated form apparently was not due to an increase in kinase activity, because there was no change in eIF-2 alpha kinase activity in extracts of liver perfused with medium containing histidinol compared to controls. Instead, the increased phosphorylation of eIF-2 alpha was associated with an inhibition of eIF-2 alpha phosphatase activity. Thus, in contrast to other systems that have been examined, the mechanism involved in the increase in the phosphorylation state of eIF-2 alpha appears to involve an inhibition of eIF-2 alpha phosphatase activity rather than activation of an eIF-2 alpha kinase.     

Morphometry, densitometry and pattern analysis of plastic-embedded histologic material from urothelial cell carcinoma of the bladder.

An image analysis method of grading histologic sections of bladder carcinoma was tested. The method was new in four respects. First, for fixation of the biopsies a coagulant fixative was used. Second, 2-microns plastic sections were used to ensure the reproducibility of nuclear imaging. Third, a new stereologic approach was used for calculation of the nuclear volume and DNA content. Fourth, for the classification rule the morphometric, densitometric and texture features were used in concert. The IBAS 2000 instrument was used for the measurements. Texture analysis of the chromatin patterns was performed using Markovian texture features. Using discriminant analysis, of 22 parameters, 2 morphometric, 2 densitometric and 3 texture features were selected for the classification rule. With them, 89% of the bladder carcinomas were correctly classified into the three grades. All grade III tumors were classified correctly. Among the features tested, the densitometry of the DNA had the highest F values. All of the grade III tumors and 45% of the grade II tumor group had DNA histograms indicating aneuploidy. This study showed that plastic-embedded material is well suited to morphometry and densitometry and can be used for quantitative grading of bladder carcinoma.     

Three saponins from Oxytropis species.

Three flavonoids and three saponins have been isolated from Oxytropis species. Their structures were determined as isorhamnetin-3-O-beta-D-glucoside, rhamnetin-3-O-beta-D-galactoside, apigenin, 3-O-[alpha-L-rhamnopyranosyl (1----2)-beta-D-glucopyranosyl(1----4)-beta-D-glucuronopyranosyl]+ ++soyasapogenol B, 3-O-[beta-D-glucopyranosyl(1----2)-beta-D-glucuronopyranosyl] azukisapogenol and a new saponin 3-O-[beta-D-glucopyranosyl(1----2)-beta-D-glucopyranosyl]-25-O-alpha-L- rhamnopyranosyl-(20S,24S)-3 beta,16 beta, 20,24,25-pentahydroxy-9,19-cycloanostane.     

Development and use of striped bass-specific RFLP probes

We sought to develop nuclear DNA (nDNA) probes which could be used to complement mtDNA and DNA fingerprinting markers in distinguishing striped bass, Morone saxatilis (Walbaum), from discrete spawning systems. Restriction endonuclease-generated single copy, 10–20-kb striped bass nuclear nDNA fragments were cloned into the bacteriophage vector Lambda Dash II and tested in Southern blot analyses for their abilities to reveal population-specific polymorphisms. Three of the I7 nDNA sequences tested exhibited polymorphisms which potentially could be used to delineate striped bass populations. One probe, DSB 22, revealed significant genotypic frequency differences between Gulf of Mexico and Atlantic striped bass and among striped bass representative of some Atlantic systems. These preliminary results suggest that single copy nDNA sequences may provide sufficient polymorphisms to aid in stock identification of species which proved genetically monomorphic using other approaches.     

Linkage of bovine erythrocyte antigen loci B, C, L, S, Z, R' and T' and the serum protein loci post-transferrin 2 (PTF 2), vitamin D binding protein (GC) and albumin (ALB) to DNA microsatellite markers

Seven bovine erythrocyte antigen loci and three serum protein loci were tentatively assigned to chromosomes or synteny groups by linkage analysis to previously assigned microsatellite DNA markers. The erythrocyte antigen locus EAB was mapped to synteny group U27; EAC to chromosome 18, synteny group U9; EAL to chromosome 3, synteny group U6; EAS to chromosome 21, synteny group U4; EAZ to chromosome 10, synteny group U5; EAR' to chromosome 16, synteny group U1; and EAT' to chromosome 19, synteny group U21. The vitamin D binding protein (GC) and albumin (ALB) loci were assigned to chromosome 6, synteny group U15 and post-transferrin 2 (PTF 2) to chromosome 19, synteny group U21.     

Integrating the porcine physical and linkage map using cosmid-derived markers

An essential part in the development of informative linkage maps is to include genetic markers that have been anchored by physical mapping. Here a set of 18 porcine cosmid-derived genetic markers are reported that have been mapped by linkge analysis, and that also have been physically localized by fluorescence in situ hybridization (FISH). Three different strategies were used to establish polymorphic markers from the cosmid clones. Firstly, dinucleotide microsatellite loci were derived by sequencing cosmid subclones containing (CA), repeats. Secondly, variable SINE 3′ poly(A) tracts (SINEVA) were identified by direct SINE-PCR amplification of cosmid clones. Thirdly, the cosmids were used in Southern blot hybridization to detect restriction fragment length polymorphisms (RFLPs). Compared with the most recent consensus compilation of the porcine gene map, the present assignment of markers to chromosomes Zp, 3, 4, 10, 12q, and 16 represents the first loci mapped to these chromosomes, for which linkage as well as in situ data are now available.     

Conservation of two predator species for biological control ofChrysophtharta bimaculata (Col.: Chrysomelidae) in tasmanian forests

Chrysophtharta bimaculata (Olivier) (Coleoptera: Chrysomelidae) is a major defoliator of regeneration eucalypt trees in Tasmania causing a significant reduction in height and diameter increment of trees which reduces wood volume per hectare. A study to conserve and enhance the efficiency of coccinellid species chieflyCleobora mellyi (Mulsant) (Coleoptera: Coccinellidae), and the cantharid,Chauliognathus pulchellus (Macleay) (Coleoptera: Cantharidae), for the biological control ofC. bimaculata was conducted in young regeneration forests in southern Tasmania from 1991–92. Cantharid adults and coccinellid adults and larvae feed onC. bimaculata eggs and, to a lesser extent, young larvae. The study found that coccinellids were more active throughout the egg and early (1^st and 2^nd) stage ofC. bimaculata. The cantharid, however was active only during the egg stage of the prey and then disappeared from the plantation. The coccinellids were therefore the most useful predators, but their population declined when the prey reached the 3^rd and 4^th stages. As shortage of food may account for this decline, supplementary food was provided in the form of sucrose sprays or sugar granules at a feeding station. This resulted in the retention of both predators and particularly the coccinellids and enhanced their efficacy.