Chromosome 22q11 deletions in patients with selected outflow tract malformations

The incidence of 22q11 deletions and its effect on the phenotype were established in 170 patients with selected outflow tract malformations and transposition of the great arteries (conotruncal defects). Cases were seen both prospectively and retrospectively. All patients had a dysmorphological evaluation by the clinical geneticist and a cytogenetic analysis including FISH analysis for 22q11 deletions. A chromosomal abnormality was present in 29 patients, including a 22q11 deletion in 22/170 patients (13%). The 22q11 deletion was found in 11% of tetralogy of Fallot, in 11% of pulmonary atresia and VSD, in 44% of pulmonary atresia. VSD and collateral arteries, in 20% of truncus arteriosus, in 60% of interrupted aortic arch and in 25% patients with aberrant subclavian artery. They were absent in double outlet right ventricle or in transposition of the great arteries. No parental deletion was found. All patients had clinical characteristics of the velocardiofacial syndrome. This study confirms a high incidence of chromosome 22q11 deletions in patients with selected outflow tract malformations, with great clinical impact for further management and genetic counseling.     

The design of potent and selective inhibitors of thrombin utilizing a piperazinedione template: part 2.

Potent and selective thrombin inhibitors have been prepared with a piperazinedione template and L-amino acids. Likewise, incorporation of D-amino acids led to potent inhibitors with a novel mode of binding. Herein, the structure activity relationships and structural aspects of these compounds will be described.     

Genetic analysis of return over feed in Canadian Holsteins

The objective of this study was to investigate genetic merit of return over feed (ROF), which is a herd profit index defined by CanWest Dairy Herd Improvement as a difference between milk income and feed cost. A multiple-trait (MT) model and random regression model (RRM) were used. The traits analyzed in MT were rearing cost and ROF of the first three lactations. In RRM, a cumulative ROF was fitted as function of age and rearing cost was treated as a correlated trait. Variance components were estimated within a Bayesian framework by Gibbs sampling using a subsample of data. Breeding values were then estimated for 3 041 078 animals using records of 1 951 893 cows. Estimates of heritability for rearing cost from MT and RRM were 0.23 and 0.22, respectively. ROF per lactation and cumulative ROF were negatively correlated with rearing cost. Estimates of heritability of ROF through the first, second and third lactation from MT were 0.27, 0.10 and 0.08, respectively. Estimates of heritability of ROF from RRM increased with age and ranged from 0.08 through 0.31. Estimated breeding values (EBVs) for ROF from MT and RRM were moderately correlated with official EBV for production traits and the Canadian selection index (Lifetime Profit Index). Herd life EBV had -0.07 and 0.19 correlations with EBVs for ROF from MT and RRM, respectively. From both MT and RRM, small favorable correlations were reported between EBVs for ROF and for bone quality and angularity, whereas low unfavorable correlations were reported with EBV for udder depth, front end and chest width. Majority of correlations between EBVs for ROF and for reproduction traits were near 0, with the exception of EBV for gestation length, calf size and calving ease, where small favorable correlations were reported. The ROF is a good indicator of cow profitability despite the fact that it is a simplified profit index that does not account for animal-specific health and reproductive cost. However, because ROF does not account for differences in heritabilities between components of profit, ROF is not recommended to be used for direct selection for profit.     

Binding of human blood-coagulation Factors IXa and X to phospholipid membranes.

A simple centrifugation technique has been developed to study the interaction of human coagulation Factors IXa and X with phospholipid membranes. In the presence of Ca2+, equimolar phosphatidylserine/phosphatidylcholine membranes form tight complexes with Factor X (KD = 2.8 X 10(-8) M); the KD is independent of the phospholipid concentration. Binding sites are available for about 2 mmol of Factor X/mol of phospholipid. Factor IXa has a slightly higher affinity for the phospholipid membrane (KD = 1.2 X 10(-8)M), and competes with Factor X for binding. The experimentally observed competition between Factor X and Factor IXa is in agreement with a model that describes the binding of two distinct ligands to a single class of independent binding sites.     

Mineralization of N and P along a trophic gradient in a freshwater mire

Release of inorganic nitrogen and phosphorus in the soil of a peatland (fen) in The Netherlands was measured by means of an in situ incubation technique. Three sampling stations were chosen along a gradient in the plant productivity and water chemistry of the fen. The station with the highest biomass production was located near the ditch that supplied the fen with water in amounts matching water losses through evaporation and downward percolation to the groundwater. Water chemistry at this station strongly resembled that of the ditch water. The two stations remote from the ditch had much lower plant biomass, and significantly lower pH, conductivity, and calcium and bicarbonate concentrations. The vegetation at these two stations was characterized by a thick Sphagnum carpet.The release of inorganic N and P was much faster at the two stations remote from the ditch than at that located near the ditch. The differences in mineralization rate are probably due to the differences in water chemistry; phosphates are more soluble at low than at high pH. The fast N mineralization at stations with a thick Sphagnum carpet may be related to the chemical composition of Sphagnum litter. The difference in productivity is not explained by the N and P mineralization rates. Direct supply of N and P from the ditch are probably the main cause of the high productivity at the station bordering the ditch.     

Cloning the FnuDI, NaeI, NcoI and XbaI restriction-modification systems

Methyltransferase genes from the FnuDI, NaeI, NcoI, and XbaI restriction-modification systems have been isolated in Escherichia coli by 'shot-gun' cloning bacterial DNA fragments into plasmid vectors and selecting for protectively modified molecules that resist digestion by the corresponding restriction endonuclease.     

Separation and comparison of two monokines with lymphocyte-activating factor activity: IL-1 beta and hybridoma growth factor (HGF). Identification of leukocyte-derived HGF as IL-6

Supernatants of mitogen-stimulated human leukocytes contain two biologically related cytokines, IL-1 and hybridoma growth factor (HGF). IL-1 beta is a potent inducer of HGF in fibroblasts but has little stimulating effect on monocytes that spontaneously produce HGF. Leukocyte-derived HGF and IL-1 were separated by the use of affinity chromatography on specific antibodies and discriminating assay systems for both cytokines. They had different Mr upon gel filtration and SDS-PAGE. In contrast to IL-1 beta, HGF showed heterogeneity on a cation-exchange column. IL-1 beta and HGF were purified to homogeneity by a sequence of four and five purification steps, respectively. Leukocyte-derived HGF was characterized by analysis of its NH2-terminal amino acid sequence. This revealed complete homology with fibroblast-derived HGF, 26-kDa protein, IFN-beta 2, and B cell stimulatory factor 2, molecules which have collectively been designated as IL-6. IL-1 beta exerted an antiviral and growth-promoting effect of fibroblasts, whereas HGF/IL-6 did not. Both IL-1 and IL-6 possessed lymphocyte-activating factor activity, which could be neutralized only by an anti-serum against the corresponding cytokine.     

A clinical experience with perforator flaps in the coverage of extensive defects of the upper extremity

Traditional skin free flaps, such as radial arm, lateral arm, and scapular flaps, are rarely sufficient to cover large skin defects of the upper extremity because of the limitation of primary closure at the donor site. Muscle or musculocutaneous flaps have been used more for these defects. However, they preclude a sacrifice of a large amount of muscle tissue with the subsequent donor-site morbidity. Perforator or combined flaps are better alternatives to cover large defects. The use of a muscle as part of a combined flap is limited to very specific indications, and the amount of muscle required is restricted to the minimum to decrease the donor-site morbidity. The authors present a series of 12 patients with extensive defects of the upper extremity who were treated between December of 1999 and March of 2002. The mean defect was 21 x 11 cm in size. Perforator flaps (five thoracodorsal artery perforator flaps and four deep inferior epigastric perforator flaps) were used in seven patients. Combined flaps, which were a combination of two different types of tissue based on a single pedicle, were needed in five patients (scapular skin flap with a thoracodorsal artery perforator flap in one patient and a thoracodorsal artery perforator flap with a split latissimus dorsi muscle in four patients). In one case, immediate surgical defatting of a deep inferior epigastric perforator flap on a wrist was performed to immediately achieve thin coverage. The average operative time was 5 hours 20 minutes (range, 3 to 7 hours). All but one flap, in which the cutaneous part of a combined flap necrosed because of a postoperative hematoma, survived completely. Adequate coverage and complete wound healing were obtained in all cases. Perforator flaps can be used successfully to cover a large defect in an extremity with minimal donor-site morbidity. Combined flaps provide a large amount of tissue, a wide range of mobility, and easy shaping, modeling, and defatting.     

Additional observations on the gross morphology and microstructure of Baccaconularia Hughes, Gunderson et Weedon, 2000, a Cambrian (Furongian) conulariid from the north-central USA

Baccaconularia Hughes, Gunderson et Weedon, 2000, from the Furongian Series (Cambrian System) of the north-central USA, has been interpreted as a conulariid cnidarian, based on a suite of gross morphological similarities shared only with other post-Cambrian genera currently assigned to this group. Closely spaced, squarish to subrectangular facial nodes of Baccaconularia are aligned in distinct longitudinal files. Nodes also display a subtler, more or less rectilinear transverse alignment, though this pattern commonly is disrupted by offset parallel to the longitudinal files. In their shape and pattern of arrangement, the nodes of Baccaconularia are most similar to the squarish to elongate nodes of Pseudoconularia Bouček, 1939. Longitudinal node files of Baccaconularia may also be compared with the longitudinal facial ridges of Conularia cambria Walcott, 1890 from the Furongian of Wisconsin. Apical angles of Baccaconularia range from approximately 13° to 14.5°. Scanning electron imaging of B. cf. robinsoni shows that its thin, phosphatic skeleton is finely lamellar, with the thickness of individual lamellae measuring approximately 1 μm. The skeleton also exhibits microscopic circular pores and crater-like pits that range from approximately 5 to 10 μm in diameter. These pores and pits are similar in size, geometry, areal density and pattern of arrangement to those of many post-Cambrian conulariids. Microscopic circular pores are documented here for the first time in the genus Archaeoconularia Bouček, 1939 from the Upper Ordovician of the Czech Republic. Although the origin of the pores and pits is open to alternative interpretations, the discovery of these features and fine lamination in Baccaconularia strengthens the argument that this genus is a Cambrian conulariid.     

Expression of foreign genes in regenerated plants and in their progeny

Chimeric genes comprised of the nopaline synthase promoter and bacterial coding sequences specifying resistance to kanamycin, chloramphenicol or methotrexate, were inserted into the non-oncogenic Ti plasmid vector pGV3850 by recombination (through homologous pBR322 sequences present in the chimeric gene constructs and pGV3850). These co-integrates in Agrobacterium were used to infect single plant protoplasts of Nicotiana by co-cultivation. The resistance traits allowed the selection of transformed calli in tissue culture in the presence of the appropriate antibiotic. Furthermore, as a non-oncogenic Ti plasmid was used for the protoplast transformation, phenotypically normal and fertile plants could be regenerated from the resistant calli. We have shown that these fully differentiated plant tissues exhibit functional expression of resistance traits (Km^R and Cm^R). All plants carrying the chimeric genes developed normally, flowered, and set seeds. The inheritance of several of these resistance traits was analyzed and shown to be Mendelian. These results are model experiments to demonstrate that genes of interest can be systematically transferred to the genome of plants using non-oncogenic Ti plasmid derivatives; and that transformed plants are capable of normal growth and differentiation, thus providing a natural environment for the study of gene expression and development of plant cells.