Adult Plant Leaf Rust Resistance in AC Taber Wheat Maps to Chromosomes 2BS and 3BS.

AC Taber is a hard red spring wheat cultivar that has had long-lasting resistance to the leaf rust fungus Puccinia triticina. The objective of this study was to determine the chromosome location of the leaf rust resistance genes in AC Taber. The leaf rust-susceptible cultivar Thatcher was crossed with AC Taber to develop an F6 recombinant inbred line (RIL) population. The RILs and parents were evaluated for segregation of leaf rust resistance in five field plot tests and in two seedling tests to race BBBDB of P. triticina. A genetic map of the RIL population was developed using 90,000 single nucleotide polymorphism markers with the Illumina Infinium iSelect 90K wheat bead array. Quantitative trait loci (QTLs) with significant effects for lower leaf rust severity in the field plot tests were found on chromosomes 2BS and 3BS. The same QTLs also had significant effects for lower infection type in seedlings to leaf rust race BBBDB. The gene on 2BS was the adult plant resistance gene Lr13, and the gene on 3BS mapped to the same region as the adult plant resistance gene Lr74 and other QTLs for leaf rust resistance. Kompetitive allele-specific PCR assay markers linked to the 2BS and 3BS regions were developed and should be useful for marker-based selection of these genes.

Parent management training.

As the estimates of prevalence and cost of mental health problems in our children continue to rise, it is incumbent on our society to have an effective and cost-efficient means to address this health crisis. Consistently, the research literature indicates that PMT offers great promise as an efficacious treatment of conduct-disordered children. There are recent studies of PMT's benefits as a preventive intervention that not only improves children's conduct but also positively affects parent-child relationships, mood, social competence, and school adjustment or performance. Although relatively untested, there are indications that PMT also could play an important adjunctive role in the treatment of internalizing disorders. As a curriculum-driven and didactic form of treatment, PMT is highly adaptable to various treatment and prevention contexts, and from a managed care perspective, PMT's structure allows its costs to be well defined and managed. Despite these positive attributes, however, few clinics systematically offer PMT as a treatment option, and third-party payers have been reluctant to cover its costs. Although it is conceded that much needs to be learned about the scope of PMT's effectiveness and the modifications that are necessary to improve its adaptability to high-risk families, it is proposed that PMT should join the mainstream of broadly available health care provisions for children and their families. This broad inclusion of PMT requires mental health educators to include PMT training as a standard part of provider training, requires that third-party payers include PMT as a covered service, and requires that local and federal governments support the proliferation of PMT in treatment and prevention initiatives.

Graphical method for the calculation of chromatographic performance in representing the trade-off between purity and recovery.

A simple engineering framework that enables the rapid representation of the performance of liquid chromatographic separations is provided in this paper. The fractionation diagram and its associated maximum purification factor versus product yield, and contamination index versus product yield diagrams, may be derived directly from chromatographic data. The fractionation diagram plots the relative change in the cumulative fractional mass of product eluted with the corresponding fractional total mass eluted, while the maximum purification factor versus yield diagram shows the degree of trade-off between the levels of purity and recovery achieved in the chromatographic step. The minimum contamination index versus yield plot is especially suitable for cases where the product and impurity are expressed in different units and shows how the extent of contaminant removal changes relative to product yield. These diagrams are more straightforward and easily interpretable compared to the basic conventional chromatograms and enable investigation of the degree of trade-off between purity and recovery for any set of operating conditions to be made. The approach is demonstrated for two different chromatographic systems. In the first, a set of simulation results from a verified size exclusion model is used to demonstrate the approach for product recovery. In the second, a set of experimental results for the removal of endotoxin from DNA is used. This demonstrates a problem where the product and impurity content are measured by different assay techniques and are expressed in different units, and also where the quality of process information is limited by the small number of fractions collected. The studies show how such an approach can help to identify the optimal operating conditions, in terms of acceptable yield and desired level of contaminant removal, and to redefine the location of product fractions needed to achieve these specifications.

A note on state individual differences in accuracy of response imagery: aftereffects and reminiscence.

In two sessions, separated by 7 days, subjects imagined themselves performing a tracking task under a massed practice schedule. After conditions of interpolated rest and no-rest, which were counterbalanced across sessions, subjects actually performed the tracking task. During imagery practice, subjects verbally reported the temporal component of the task. The temporal accuracy of verbal reports varied widely across subjects, but not within subjects. Furthermore, a performance gain was demonstrated as a function of interpolated rest versus no-rest (reminiscence effect). Finally, the accuracy of verbal reports predicted imagery aftereffects, but not reminiscence effects.

Biocatalysis in organic chemistry (Part I): Past and present.

Methods used in the manufacture of both ethanol and ascorbic acid have been developed over the past 150 years. The early stages of the development of both processes were characterized by the interaction between chemists, biologists and engineers, but social and economic influences also played their part. The history of these two examples illustrates the diversity of skills and influences needed for the application of biological catalysis to large-scale chemical manufacture.

A survey of nitrite concentrations in retail fresh vegetables.

A survey of nitrite (NO2-) in fresh retail vegetables was conducted in the UK over twelve months. Samples of lettuce, cabbage, spinach, potatoes and carrots were bought at two-monthly intervals and analysed within 30 h of purchase using a method developed for fresh vegetables. Of 606 edible samples, 566 (93.4%) had no detectable NO2-, and 40 (mainly potatoes) contained trace amounts (< 0.4 mg kg-1). Four samples (spinach) which had deteriorated during their shelf-life and were considered inedible had amounts ranging from 12 to 222 mg kg-1 NO2-. The results confirm that poor storage is a rare occurrence in retail vegetables in the UK.

Correlation of biocatalytic activity in an organic-aqueous two-liquid phase system with solvent concentration in the cell membrane.

Results presented here show that loss of progesterone 11 alpha-hydroxylase activity in Rhizopus nigricans in aqueous-organic two-liquid phase and cosolvent systems correlates well with the concentration of solvent in the cell membranes. Rhizopus nigricans is shown to retain full 11 alpha-hydroxylase activity at saturating aqueous phase concentrations of hexane and the higher primary alcohols. This reflects their inability to attain a critical concentration in the cell membranes. The relationship between our own findings and the previously described correlation of the logarithm of the partition coefficient with activity retention is explained and design parameters are proposed that may be used to select solvents for future biocatalytic systems.

Characterization of a loss-of-function mutation in the isopenicillin N synthetase gene of Acremonium chrysogenum.

The N-2 strain of Acremonium chrysogenum accumulates the beta-lactam precursor tripeptide delta-(L-alpha-amino-adipoyl)-L-cysteinyl-D-valine and has no discernible activity for three of the cephalosporin C (Ce) biosynthetic enzymes. This phenotype is consistent with a mutation either within pcbC [the isopenicillin N synthetase (IPNS)-encoding gene] or in a pathway-regulator gene. To distinguish these possibilities we have cloned and sequenced pcbC from strain N-2. There is a single C----T mutation at nt 854 within the coding sequence, changing aa 285 from proline to leucine. An IPNS-specific monoclonal antibody recognises a catalytically inactive IPNS protein in extracts of N-2 cells. These findings suggest that strain N-2 carries a simple IPNS mutation and that IPNS or its biosynthetic product isopenicillin N is involved in regulation of the later stages of the Ce biosynthetic pathway.

Ventricular gallbladder shunts: an alternative procedure in hydrocephalus.

Hydrocephalus is a frequently encountered problem in infancy and is most commonly treated by placement of ventriculoperionteal (VP) or ventriculoatrial (VA) shunts. Other sites for insertion of the distal shunt have included the stomach, ureter, and fallopian tube. This report describes an experience with ventricular gallbladder shunts (VGB) in 25 children performed from 1970 to 1985. There were 13 girls and 12 boys ranging in age from 6 months to 16 years. Diagnosis included meningomyelocoele (7), congenital hydrocephalus (7), postmeningitic complications (5), intracranial tumor (4), and intraventricular hemorrhage (2). Indications for operation included VP shunt infection (15), massive ascites following VP shunt (3), VA shunt infection (4), and distal shunt malfunction due to fibrinous adhesions or cysts (secondary to infection; (3). Three patients had early shunt failure due to proximal obstruction (2) and gallbladder atony (1). Shunt revision was required in two and the atony was successfully treated with cholecystokinin in one. Fourteen shunts remain in place, two patients have been lost to follow-up, and three children died from unrelated causes. Seventy percent of the 20 patients available for long-term follow-up have functional shunts in place. The VGB shunt procedure remains an attractive alternative for patients with hydrocephalus in whom intraperitoneal and intravascular shunts are no longer feasible.

Complications and reoperation after Nissen fundoplication in childhood.

Over a 10 year period, 429 Nissen fundoplications were performed on children with gastroesophageal reflux. Postoperative complications occurred in 69 children (16 percent), including wrap herniation or breakdown in 29; postoperative bowel obstruction in 18; stricture in 10; intraabdominal abscess and enterocutaneous fistula in 3 patients each; and wound infection, wound dehiscence, and inadvertent splenectomy in 2 patients each. The postoperative mortality rate was 0.9 percent (4 of 429 patients) and was related to sepsis in 1 patient, a metabolic disorder in 1 patient, and underlying pulmonary disease in 2 patients. All four patients were neurologically impaired. Fundoplication successfully controlled symptoms of gastroesophageal reflux in 395 children (92 percent) over a follow-up period ranging from 6 months to 10 years. Thirty-eight patients (8.8 percent) required a second antireflux operation because of recurrent symptoms. Twenty-nine patients had severe neurologic impairment (76 percent), 5 had associated congenital malformations (13 percent), and 3 had significant pulmonary problems (8 percent). Only one child requiring reoperation was considered otherwise normal. Indications for reoperation included wrap breakdown or herniation (28 patients), stricture (6 patients), and inadequate wrap (4 patients). Twenty-four of 28 children with wrap herniation or breakdown had neurologic impairment. A second fundoplication was successful in 35 of 38 patients (92 percent). A second procedure failed in three children, who required subsequent resection and colon interposition.

An adenosine triphosphate-dependent carbamoylphosphate--3-hydroxymethylcephem O-carbamoyltransferase from Streptomyces clavuligerus.

Cell-free supernatants from cells of Streptomyces clavuligerus (N.R.R.L. 3585), which are actively synthesizing cephamycin C, transfer a carbamoyl group from carbamoylphosphate to a 3-hydroxymethylceph-3-em-4-carboxylic acid nucleus to form a 3-carbamoyloxymethylcephem. This reaction was stimulated by nucleoside triphosphates and by a mixture of Mn2+ and Mg2+ cations. The enzyme responsible was purified 40-fold by batch absorption onto DEAE-cellulose and hydroxyapatite. The purified O-carbamoyltransferase is most active at pH 6.8. It is stabilized by phosphate anions, but is inhibited by PPi anions, (NH4)2SO4 or NaCl. The enzyme is stimulated by ATP, but it is not known whether this nucleotide acts as an effector or as a substrate. Some activity is observed with dATP, but two other analogues of ATP, in which a methylene group replaced the oxygen atom between the alpha- and beta- or the beta- and gamma-phosphorus atoms, inhibit the action of ATP itself. The enzyme synthesizes a wide range of 3-carbamoyloxymethylcephems. The structure of some of these products, for example that of cefuroxime (3-carbamoyloxymethyl-7 beta-[2-(fur-2-yl)-2-syn-methoxyiminoacetamido]ceph-3-em-4-carboxylic acid), was confirmed by their proton-n.m.r. spectra.

The oxygenation of [3-methyl-3H]desacetoxycephalosporin C [7beta-(5-D-aminadipamido)-3-methylceph-3-em-4-carboxylic acid] to [3-hydroxymethyl-3H]desacetylcephalosporin C by 2-oxoglutarate-linked dioxygenases from Acremonium chrysogenum and Streptomyces clavuligerus.

Cell-free extracts of Acremonium chrysogenum and Streptomyces clavuligerus oxidize the 3-methyl group of desacetoxycephalosporin C to a 3-hydroxymethyl group. The enzyme responsible for this reaction in these organisms was purified 20- and 30-fold respectively by chromatography on DEAE-cellulose. The enzymes, which were assayed with [3-methyl-3H]desacetoxycephalosporin C as substrate, have the properties expected of 2-oxoglutarate-linked dioxygenases. They require 2-oxoglutarate, Fe2+ cations and a mixture of reducing agents (dithiothreitol and ascorbate) for full activity. The enzyme from A. chrysogenum, but not that S. clavuligerus, is activated about 10-fold when it is preincubated with a reaction mixture from which either desacetoxycephalosporin C or 2-oxoglutarate is omitted. Fe2+ cations seem to play a key role in this activation. Both enzymes seem highly specific for cephalosporins with the natural 7beta-(5-D-aminoadipamido) side chain and are likely to be responsible for the oxidation of the 3-methylcephem nucleus in vivo.