No abstract

No abstract

The cyanogenic polymorphism in white clover is controlled by alleles of two independently segregating loci. Biochemical studies have shown that non-functional alleles of the Ac locus, which controls the level of cyanoglucoside produced in leaf tissue, result in the loss of several steps in the biosynthetic pathway. Alleles of the Li locus control the synthesis of the hydrolytic enzyme, linamarase, which is responsible for HCN release following tissue damage. Studies on the selective forces and the distribution of the cyanogenic morphs of white clover are discussed in relation to the quantitative variation in cyanogenesis revealed by biochemical studies. Molecular studies reveal considerable restriction fragment length polymorphism for linamarase homologous genes.

Six different putative UDP-glucose glucosyltransferase clones were isolated from a cassava cotyledon cDNA library probed with an Acc I-Bgl II restriction fragment from a UDP-glucose flavonoid 3-O-glucosyltransferase from Antirrhinum majus. The heterologous probe contained a glucosyltransferase consensus signature amino acid sequence which was also present in the cassava cDNA clones. Nucleotide and derived amino acid sequences are presented for two of the clones. Northern analysis showed different patterns of expression for the six genes in developing seedling tissues, indicating temporal and tissue-specific regulation. A comparative analysis was made of the six cassava clone derived amino acid sequences and other reported UDP-glucosyltransferase genes. Highly conserved residues in plant genes from three species allow redefinition of essential residues within the signature sequence for secondary plant product metabolism glucosyltransferase genes.

Introduction: Open surgery for pancreatic necrosis is associated with considerable morbidity and mortality. We report the results of a recently developed minimally invasive technique that we adopted in 1998. Methods: A descriptive explanation of the approach is given together with the results of a retrospective analysis of patients who underwent a minimally invasive retroperitoneal pancreatic necrosectomy (MIRP) between August 1998 and April 2002. Patients: There were 24 patients with a median (range) age of 61 (29–75) years. The initial median (range) APACHE II score was 8 (2–21). All patients had infected pancreatic necrosis with at least 50% pancreatic necrosis. In three patients it was not possible to complete the first MIRP because of technical reasons. Results: A total of 88 procedures were performed with a median (range) of 4 (0–8) per patient. Twenty-one (88%) patients developed 36 complications during the course of their illness. Five patients required an additional open procedure: 2 for subsequent distant collections, 2 for bleeding and 1 for persisting sepsis and a distant abscess. Six (25%) patients who had MIRP died. The median (range) post-operative hospital stay was 51 (5–200) days. Conclusions: MIRP is a new technique that has shown promising results, and could be preferable to open pancreatic necrosectomy in selected patients. However, unresolved issues remain to be overcome and the exact role of MIRP in the management of pancreatic necrosis has yet to be defined.