Thrombolytic Therapy in Haemolytic-Uraemic Syndrome

The treatment of five children with the haemolytic-uraemic syndrome using streptokinase is described to illustrate the difficulties and limitations of thrombolytic therapy in this disease. This experience is germane to the design of multicentre clinical trials.A multivariate analysis relating clinical outcome to the data obtained at the time of admission was also carried out for 31 children with the disease treated in four centres. The results suggest that this technique may help to identify those patients likely to have a fatal outcome. An expanded form of this type of analysis should be incorporated in future clinical trials.     

The localization of enzymes in the cotyledons of Pisum arvense L. during germination

Summary Enzyme activity is not uniformly distributed through the cotyledon of Pisum arvense. Initially the peripheral region, certain scattered cells of the storage tissue and the procambium show a high level of activity of succinic dehydrogenase, cytochrome oxidase, acid phosphatase and esterase. Activity of acid phosphatase declines sharply after the first day of germination; activity of the other enzymes declines after about three days. In the storage tissue, where activity is lower initially, it declines after about five days and is correlated with the disappearance of the reserves. The pattern of alkaline phosphatase activity is similar except that activity is lower in the procambium but increases in the sieve-elements during differentiation of the phloem. 5-nucleotidase and glucose-6-phosphatase activity is low throughout the cotyledon but it also increases to a significant level in the sieve-elements. Activity of starch synthesizing enzymes is high in the parenchymatous bundle sheath, where they may be involved in the pathway from lipids to soluble carbohydrates.     

mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species

Reconstructions of the human-African great ape phylogeny by using mitochondrial DNA (mtDNA) have been subject to considerable debate. One confounding factor may be the lack of data on intraspecific variation. To test this hypothesis, we examined the effect of intraspecific mtDNA diversity on the phylogenetic reconstruction of another Plio- Pleistocene radiation of higher primates, the fascicularis group of macaque (Macaca) monkey species. Fifteen endonucleases were used to identify 10 haplotypes of 40-47 restriction sites in M. mulatta, which were compared with similar data for the other members of this species group. Interpopulational, intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of divergence time and branching order incorporating this variation were substantially different from those based on single representatives of each species. We conclude that intraspecific mtDNA diversity is substantial in at least some primate species. Consequently, without prior information on the extent of genetic diversity within a particular species, intraspecific variation must be assessed and accounted for when reconstructing primate phylogenies. Further, we question the reliability of hominoid mtDNA phylogenies, based as they are on one or a few representatives of each species, in an already depauperate superfamily of primates.      

Evaluation of somatic embryos of interior spruce. Characterization and developmental regulation of storage proteins

Storage proteins of interior spruce ( Picea glauca engelmanii complex) somatic embryos were compared to those of zygotic embryos by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Somatic embryos contain the same storage proteins as zygotic embryos based on similarities of molecular weight, isoelectric variants, solubility characteristics and disulfide linkages. Storage protein levels varied among different somatic embryo genotypes; however, all genotypes tested accumulated significant amounts of storage proteins. Zygotic and somatic embryos display a similar developmental accumulation of storage proteins. The 22, 24, 33 and 35 kDa proteins appear in early stage embryos, while the 41 kDa protein begins to accumulate during mid cotyledon development. The 22, 24 and 41 kDa proteins accumulate continuously during cotyledon development in somatic embryos cultured on abscisic acid. In contrast, zygotic embryos display a more rapid and transient accumulation of these proteins.     

Postexercise protein supplementation improves health and muscle soreness during basic military training in Marine recruits.

Elevated postexercise amino acid availability has been demonstrated to enhance muscle protein synthesis acutely, but the long-term impact of postexercise protein supplementation on variables such as health, muscle soreness, and function are unclear. Healthy male US Marine recruits from six platoons (US Marine Corps Base, Parris Island, SC; n = 387; 18.9 +/- 0.1 yr, 74.7 +/- 1.1 kg, 13.8 +/- 0.4% body fat) were randomly assigned to three treatments within each platoon. Nutrients supplemented immediately postexercise during the 54-day basic training were either placebo (0 g carbohydrate, 0 g protein, 0 g fat), control (8, 0, 3), or protein supplement (8, 10, 3). Subjects and observers making measurements and data analysis were blinded to subject groupings. Compared with placebo and control groups, the protein-supplemented group had an average of 33% fewer total medical visits, 28% fewer visits due to bacterial/viral infections, 37% fewer visits due to muscle/joint problems, and 83% fewer visits due to heat exhaustion. Recruits experiencing heat exhaustion had greater body mass, lean, fat, and water losses. Muscle soreness immediately postexercise was reduced by protein supplementation vs. placebo and control groups on both days 34 and 54. Postexercise protein supplementation may not only enhance muscle protein deposition but it also has significant potential to positively impact health, muscle soreness, and tissue hydration during prolonged intense exercise training, suggesting a potential therapeutic approach for the prevention of health problems in severely stressed exercising populations.     

Vertex analysis of Purkinje cell dendritic trees in the cerebellum of the rat

All networks are made up of vertices (points interconnected by segments), which include terminals interconnected by terminal segments, nodes interconnected by link segments and the root point connected to the tree by the root segment. All nodes may be classified into unique types according to the number of terminal and link segments they drain. For example, there are three distinct dichotomous nodes, a 'primary' node draining two terminal segments, a 'secondary' node draining one terminal segment and a link segment, and a 'tertiary' node draining two link segments. The numbers of primary and tertiary nodes approximate to equality in large networks and thus the ratio of primary to secondary nodes defines topology. All higher order nodes ( trichotomous and beyond) may be resolved into dichotomous forms and incorporated into the analysis. Different forms of growth may thus be analysed by comparing the frequency distributions of nodes with those generated by computer simulated growth models. Moreover, all vertices can be ordered so that metrical parameters are easily incorporated and the hierarchical arrangements of vertices of different order discerned. The dendritic trees of 48 Purkinje cells, taken from folia along the primary fissure, were analysed using vertex analysis. The mean number of segments in Purkinje cell trees was 881 +/- 23 (s.e.) and mean total dendritic length 7959 +/- 233 (s.e.) micrometers. Segment lengths were longest over proximal segments but over most of the tree segment lengths were constant at 10 +/- 0.2 (s.e.) micrometers. Vertex, segment and terminal frequency distributions of equivalent orders were all normal with a slight positive skew. Peak frequencies were recorded at the 12th equivalent order. The mean primary/secondary nodal vertex ratio was 0.93 and the proportion of trichotomous branch points in the tree was 5%. Comparison of the frequency distribution of all vertices with computer generated models showed that growth of the Purkinje cell was most closely simulated by a random terminal growth model, incorporating 5% trichotomy , in which the branching of high order terminals was more likely than low order terminals. It was concluded that growth of the Purkinje cell tree could proceed by random terminal branching with growth occurring preferentially over a front composed of terminals that are ascending through a corridor in the molecular layer whose margins are defined by neighbouring trees.     

Bicyclic peptidomimetic tetrahydrofuro[3,2-b]pyrrol-3-one and hexahydrofuro[3,2-b]pyridine-3-one based scaffolds: synthesis and cysteinyl proteinase inhibition

A stereoselective synthesis of (3aS,6aR)-tetrahydrofuro[3,2-b]pyrrol-3-ones and (3aS,7aR)-hexahydrofuro[3,2-b]pyridine-3-ones has been developed through Fmoc protected scaffolds 12 and 13. A key design element within these novel bicyclic scaffolds, in particular the 5,5-fused system, was the inherent stability of the cis-fused geometry in comparison to that of the corresponding trans-fused. Since the bridgehead stereocentre situated beta to the ketone was of a fixed and stable configuration, the fact that cis ring fusion is both kinetically and thermodynamically stable with respect to trans ring fusion provides chiral stability to the bridgehead stereocentre that is situated alpha to the ketone. To exemplify this principle, building blocks 12 and 13 were designed, prepared and utilised in a solid phase combinatorial synthesis of peptidomimetic inhibitors 10, 45a-e, 11 and 46. Both series were chirally stable with 5,5-series 10 and 45a-e exhibiting potent in vitro activity against a range of CAC1 cysteinyl proteinases. Compound 10, a potent and selective inhibitor of cathepsin K, possessed good primary DMPK properties along with promising activity in an in vitro cell-based human osteoclast assay of bone resorption.     

Recruitment of chromatin remodelling factors during gene activation via the glucocorticoid receptor N-terminal domain

We have shown that yeast mutants with defects in the Ada adaptor proteins are defective in hormone-dependent gene activation by ectopically expressed human glucocorticoid receptor (GR). Others have shown that the Ada2 protein is required for physical interactions between some activation domains and TBP (TATA-binding protein), whereas the Gcn5 (Ada4) protein has a histone acetyltransferase (HAT) activity. Although all HAT enzymes are able to acetylate histone substrates, some also acetylate non-histone proteins. Taken together, these observations suggest that the Ada proteins have the ability to effect different steps in the process of gene activation. It has recently been shown that the Ada proteins are present in two distinct protein complexes, the Ada complex and a larger SAGA complex. Our recent work has focused on determining (1) which of the Ada-containing complexes mediates gene activation by GR, (2) whether the HAT activity encoded by GCN5 is required for GR-dependent gene activation, (3) whether the Ada proteins contribute to GR-mediated activation at the level of chromatin remodelling and (4) how the role of these HAT complexes is integrated with other chromatin remodelling activities during GR-mediated gene activation. Our results suggest a model in which GR recruits the SAGA complex and that this contributes to chromatin remodelling via a mechanism involving the acetylation of histones. Furthermore, recruitment of the SWI/SNF remodelling complex also has a role in GR-mediated activation that is independent of the role of SAGA. These complexes are similar to analogous mammalian complexes and therefore these results are likely to be relevant to the human system.