Relationships between transient elastography values and liver fibrosis in chronic liver disease patients with normal or mildly abnormal aminotransferase levels

This study aimed to evaluate relationships between transient elastography values and liver fibrosis in chronic liver disease patients with normal or mildly abnormal aminotransferase levels. Fifty-six patients were enrolled in the study. Transient elastography and liver biopsy were performed on the same day, and the fibrosis was staged based on the Scheuer scoring system. Liver stiffness was measured to assessed liver fibrosis using transient elastography. The transient elastography values of 12 patients with chronic hepatitis B were studied before and 6 months after antiviral treatment. The sensitivity and specificity for 10.88 kPa in S3 were 80 and 87.8%, and for 19.4 kPa in S4, were 100 and 90.7%, respectively. In univariate analysis, liver stiffness strongly correlated with the fibrosis stage (r = 0.70, P < 0.5), moderately correlated with the aminotransferases (r = 0.398, P < 0.05), and poorly correlated with the degree of necroinflammatory activity (r = 0.19, P < 0.5). In multivariate regression, liver stiffness correlated only with the fibrosis stage (P < 0.05). Pre- and post-treatment viral loads were not significantly different [(4.81 ± 0.15) x 10(6) vs (7.62 ± 0. 16) x 10(3), P > 0.05]. Pre- and post-treatment LS measurements were not correlated with viral load (P > 0.05). Pre- and post-treatment LS measurements were not significantly different (P > 0.02). In conclusion, transient elastography values correlated with the stage of cirrhosis, alanine aminotransferase levels, and antiviral treatment in patients with chronic hepatitis B and did not correlate with viral loads.

Cloning and RNAi-mediated functional characterization of MaLac2 of the pine sawyer, Monochamus alternatus

Laccase, a member of a group of proteins collectively known as multicopper oxidases, is hypothesized to play an important role in insect cuticle sclerotization by oxidizing catechols in the cuticle to their corresponding quinones, which then catalyze protein cross-linking reactions. Laccase 2 has been proved as the gene required for beetle cuticle tanning through RNA interference (RNAi) experiments on red flour beetle Tribolium castaneum. The pine sawyer beetle, Monochamus alternatus (Coleoptero: Cerambycidae) is the insect serving as a major vector of the pinewood nematode, Bursaphelenchus xylophilus, which is the causative agent for pine wilt disease. The cDNA of MaLac2 was cloned from the insect in this study. The conceptual amino-acid sequence deduced was much conserved with other known insect laccases, particularly with the enzyme of Tribolium castaneum. Injection in hemolymph of pine sawyer larva of dsRNA targeting the laccase 2 mRNA leads to important alterations of the tanning, hardening and sclerotization of the pupal and adult cuticles. Defaults appear in a dose-dependent manner and high loads of dsRNA are lethal. The decrease of the endogenous laccase 2 mRNA affects the procuticle which is thinner and without the characteristic piling up of successive layers. The observations reinforce the role of laccase 2 as an essential phenoloxidase for making cuticle.

Identifications of two different mechanisms for sorghum midge resistance through QTL mapping

Sorghum midge is the one of the most damaging insect pests of grain sorghum production worldwide. At least three different mechanisms are involved in midge resistance. The genetic bases of these mechanisms, however, are poorly understood. In this study, for the first time, quantitative trait loci associated with two of the mechanisms of midge resistance, antixenosis and antibiosis, were identified in an RI (recombinant inbred) population from the cross of sorghum lines ICSV745 x 90562. Two genetic regions located on separate linkage groups were found to be associated with antixenosis and explained 12% and 15%, respectively, of the total variation in egg numbers/spikelet laid in a cage experiment. One region was significantly associated with antibiosis and explained 34.5% of the variation of the difference of egg and pupal counts in the RI population. The identification of genes for different mechanisms of midge resistance will be particularly useful for exploring new sources of midge resistance and for gene pyramiding of different mechanisms for increased security in sorghum breeding through marker-assisted selection.

The cytological and genetic characterisation of doubled haploid lines derived from triticale×wheat hybrids

Anther culture, when applied to hexaploid triticale×wheat hybrids, offers the opportunity to re-assort wheat D genome and rye R genome chromosomes into homozygous doubled haploid lines in a single generation. The characterisation of such lines is the first step in their utilisation in wheat improvement. Two lines, M24 and M25 from the cross of 'Beagle'×'Kedong 58', and one line, M27, from the cross 'Beagle'×'Jinghua No. 1' have been characterised using different methods including conventional cytology and chromosome banding, and by using marker systems for storage protein composition (glutenins and gliadins), isozymes (α-amylase, aminopeptidase, glutamate oxaloacetic transaminase (GOT)) and RFLP markers. The results from all approaches were consistent in proving that M24 is a whole chromosome 6R/6D substitution line, while M25 and M27 are whole chromosome 1R/1D substitution lines. The relative advantages and disadvantages of each method of identification are also discussed.

Recombination of R-D chromosome in pollen plants cultured from hybrid of 6x Triticale x common wheat

Ninety-three pollen plants derived from the hybrid F1 of 6x Triticale x common wheat were observed cytologically. The rye chromosomes presented in these plants were identified by Giemsa-banding. Pollen plants having chromosome constitution 2n = 24 in haploids and 2n=46 in diploids were found to be predominant. The chromosome distributions of the R and D genome are different. R chromosomes distributed randomly and tended to full combination in offspring, but D chromosomes distributed non-randomly and tended to maintain intact.