Genetic analyses of native Fusarium head blight resistance in two spring wheat populations identifies QTL near the B1, Ppd-D1, Rht-1, Vrn-1, Fhb1, Fhb2, and Fhb5 loci

QTL analyses of two bi-parental mapping populations with AC Barrie as a parent revealed numerous FHB-resistance QTL unique to each population and uncovered novel variation near Fhb1. Fusarium head blight (FHB) is a destructive disease of wheat worldwide, leading to severe yield and quality losses. The genetic basis of native FHB resistance was examined in two populations: a recombinant inbred line population from the cross Cutler/AC Barrie and a doubled haploid (DH) population from the cross AC Barrie/Reeder. Numerous QTL were detected among the two mapping populations with many being cross-specific. Photoperiod insensitivity at Ppd-D1 and dwarfing at Rht-B1 and Rht-D1 was associated with increased FHB susceptibility. Anthesis date QTL at or near the Vrn-A1 and Vrn-B1 loci co-located with major FHB-resistance QTL in the AC Barrie/Reeder population. The loci were epistatic for both traits, such that DH lines with both late alleles were considerably later to anthesis and had reduced FHB symptoms (i.e., responsible for the epistatic interaction). Interestingly, AC Barrie contributed FHB resistance near the Fhb1 locus in the Cutler population and susceptibility in the Reeder population. Analyses of the Fhb1 candidate genes PFT and TaHRC confirmed that AC Barrie, Cutler, and Reeder do not carry the Sumai-3 Fhb1 gene. Resistance QTL were also detected at the expected locations of Fhb2 and Fhb5. The native FHB-resistance QTL detected near Fhb1, Fhb2, and Fhb5 do not appear to be as effective as Fhb1, Fhb2, and Fhb5 from Sumai-3. The presence of awns segregated at the B1 awn inhibitor locus in both populations, but was only associated with FHB resistance in the Cutler/AC Barrie population suggesting linkage caused the association rather than pleiotropy.

Immediate Repair and Early Mobilization of the Extensor Pollicis Longus Tendon in Zones 1 to 4

We present the results of repair and early mobilization of 100 extensor pollicis longus (EPL) tendon injuries in zones 1 to 4 in 100 patients using a dynamic outrigger splint which controlled metacarpophalangeal joint movements but allowed free movement of the interphalangeal joint. Eighty-two were complete divisions of the tendon and 18 were 80% to 99% tendon divisions. Analysis of measurements obtained routinely at 8 weeks showed 81% excellent and good results using the TAM system. There were 90% excellent and good results in the 72 patients who were followed-up and received therapy for 12 weeks. Except on the rare occasion when the repair ruptures, loss of thumb extension was not a common functional problem, but scar tethering of the repaired tendon can result in loss of thumb flexion. While loss of metacarpophalangeal joint flexion appeared to have little functional importance, loss of interphalangeal joint flexion and slowing of the movements of this joint can cause functional problems. When interphalangeal joint hyperextension is present before the injury, it is frequently lost but this generally goes unnoticed by the patients. The problems of analysing the EPL injury using the methods of assessment available are discussed.

The Results of Immediate Re-Repair of Zone 1 and 2 Primary Flexor Tendon Repairs which Rupture

This study reports the outcome of immediate re-repair of primary flexor tendon repairs in zones 1 and 2 of the fingers which had ruptured. Between June 1989 and May 2003, a total of 62 fingers in 61 patients presented with ruptured flexor tendon repairs within 48 hours from rupture. Immediate re-repair and rehabilitation was carried out in 44 fingers (71%) in 43 (70%) patients. Thirty-six patients completed the 8-week therapy programme after re-repair in 37 fingers. Nine (24%) had excellent, 10 (27%) good, 5 (14%) fair and 13 (35%) had poor results when assessed by the original Strickland method. Five fingers in five patients ruptured the re-repair. Poor results and second ruptures were particularly common after re-repair of ruptured tendon repairs in the little finger. In the light of these findings, a policy for dealing with ruptured primary flexor tendon repairs in the fingers is suggested.

Transcriptome Analysis of Poplar during Leaf Spot Infection with Sphaerulina spp

Diseases of poplar caused by the native fungal pathogen Sphaerulina musiva and related species are of growing concern, particularly with the increasing interest in intensive poplar plantations to meet growing energy demands. Sphaerulina musiva is able to cause infection on leaves, resulting in defoliation and canker formation on stems. To gain a greater understanding of the different responses of poplar species to infection caused by the naturally co-evolved Sphaerulina species, RNA-seq was conducted on leaves of Populus deltoides, P. balsamifera and P. tremuloides infected with S. musiva, S. populicola and a new undescribed species, Ston1, respectively. The experiment was designed to contain the pathogen in a laboratory environment, while replicating disease development in commercial plantations. Following inoculation, trees were monitored for disease symptoms, pathogen growth and host responses. Genes involved in phenylpropanoid, terpenoid and flavonoid biosynthesis were generally upregulated in P. balsamifera and P. tremuloides, while cell wall modification appears to play an important role in the defense of P. deltoides. Poplar defensive genes were expressed early in P. balsamifera and P. tremuloides, but their expression was delayed in P. deltoides, which correlated with the rate of disease symptoms development. Also, severe infection in P. balsamifera led to leaf abscission. This data gives an insight into the large differences in timing and expression of genes between poplar species being attacked by their associated Sphaerulina pathogen.

Identification of genes in Thuja plicata foliar terpenoid defenses

Thuja plicata (western redcedar) is a long-lived conifer species whose foliage is rarely affected by disease or insect pests, but can be severely damaged by ungulate browsing. Deterrence to browsing correlates with high foliar levels of terpenoids, in particular the monoterpenoid α-thujone. Here, we set out to identify genes whose products may be involved in the production of α-thujone and other terpenoids in this species. First, we generated a foliar transcriptome database from which to draw candidate genes. Second, we mapped the storage of thujones and other terpenoids to foliar glands. Third, we used global expression profiling to identify more than 600 genes that are expressed at high levels in foliage with glands, but can either not be detected or are expressed at low levels in a natural variant lacking foliar glands. Fourth, we used in situ RNA hybridization to map the expression of a putative monoterpene synthase to the epithelium of glands and used enzyme assays with recombinant protein of the same gene to show that it produces sabinene, the monoterpene precursor of α-thujone. Finally, we identified candidate genes with predicted enzymatic functions for the conversion of sabinene to α-thujone. Taken together, this approach generated both general resources and detailed functional characterization in the identification of genes of foliar terpenoid biosynthesis in T. plicata.

Biotinylation and characterization of Cryptococcus neoformans cell surface proteins

AIMS

To develop a novel procedure for isolating and characterizing cryptococcal cell-surface proteins using biotinylation, fluorescein isothiocyanate (FITC)-streptavidin, flow cytometry and associated ligand-receptor analysis, confocal microscopy and electrophoretic separation.

METHODS AND RESULTS

Cell proteins of both acapsulate and encapsulated Cryptococcus neoformans cells were labelled using sulfo-NHS-biotin which, in turn, was complexed with FITC-streptavidin. Resulting cell population fluorescence supported visualization of cell-surface protein distribution by confocal microscopy, as well as evaluation of protein exposure by flow cytometry and the calculation of the ligand-binding determinants EC(50), F(max) and H(n). Biotinylation of cell-surface proteins also supported their isolation by affinity chromatography and characterization by SDS/PAGE. Ligand-binding determinants, such as EC(50) values, indicated that acapsulate and stationary phase cells have greatest affinity for biotin. F(max) values demonstrated greatest protein exposure among stationary phase cells; in turn, encapsulated cells expose more protein than acapsulate counterparts. H(n) values of below unity potentially confirm the complex multi-receptor nature of biotin binding to cryptococcal cell surfaces under investigation. Fluorescence visualization showed marked but localized fluorescence indicative of protein exposure around sites of cell division. In turn, biotinylation of cell-surface proteins and their release under reducing conditions demonstrated at least two noncovalently linked proteinaceous entities, of 43 and 57 kDa, exposed on acapsulate cryptococcal cell walls.

CONCLUSIONS

A novel method for identifying, in situ, cell-surface proteins exposed by C. neoformans was established. This novel technique was successfully implemented using both acapsulate and encapsulated C. neoformans cells, both were found to have dynamic and markedly localized protein distribution around sites of cell division and associated cell wall trauma.

SIGNIFICANCE AND IMPACT OF THE STUDY

A novel procedure, employing a versatile combination of flow cytometry, ligand-receptor analysis, confocal microscopy and biotinylation, supported the characterization and isolation of cryptococcal cell-surface proteins.

A comparison of dynamic extension splinting and controlled active mobilization of complete divisions of extensor tendons in zones 5 and 6

We present a prospective randomized trial of two groups of 50 patients each having complete zone 5 and 6 extensor tendon injuries. These were rehabilitated by the use of either a dynamic outrigger splint or a palmar blocking splint. The results were analysed using the Miller and TAM assessments. Good and excellent results were achieved in 95 and 98% of cases following dynamic outrigger mobilization and 93 and 95% of cases using palmar blocking splint mobilization, using the Miller and TAM assessments respectively. There was no statistical difference in the results obtained between the two groups. Therefore, we prefer the latter technique which is simple, cheap, more convenient and requires less therapy time.

The rôle of thymidine phosphorylase/PD-ECGF in cancer chemotherapy: a chemical perspective

The angiogenic growth factor thymidine phosphorylase/PD-ECGF has been identified as a potential target in the development of anti-cancer drugs. This review firstly discusses the biological rôle of TP/PD-ECGF and its importance in the activation of 5-fluorouracil and its prodrugs. The chemistry and chemotherapeutic potential of TP/PD-ECGF inhibitors are also discussed.

The aetiology of acute rupture of flexor tendon repairs in zones 1 and 2 of the fingers during early mobilization

Five hundred and eight patients with 840 acute complete flexor tendon injuries in 605 fingers in zones 1 and 2 underwent surgery and postoperative mobilization in a controlled or early active motion (active flexion-active extension) regimen over a period of 7.5 years. Sixty-eight patients with 79 finger flexor divisions who did not complete the rehabilitation programme were excluded. Of the 440 patients with 728 complete tendon divisions in 526 fingers included in the study, 23 patients ruptured 28 tendon repair(s) in 23 fingers, an overall rupture rate of 4%. One hundred and twenty-nine fingers with zone 1 injuries had a rupture rate of 5%. Three hundred and ninety-seven fingers with zone 2 injuries had a rupture rate of 4%. This study analyses the 23 patients with flexor tendon rupture(s) to identify causative factors. In approximately half of these patients, tendon rupture followed acts of stupidity. The implications of this are discussed. There was no significant relationship between tendon rupture and the age or sex of the patients, smoking or delay between injury and tendon repair and there was no particular prevalence of zone 2C level injuries among the fingers in which tendon rupture occurred.

The essential schizosaccharomyces pombe cdc23 DNA replication gene shares structural and functional homology with the Saccharomyces cerevisiae DNA43 (MCM10) gene

The fission yeast cdc23 gene is required for correct DNA replication: cdc23 mutants show reduced rates of DNA synthesis and become elongated after cell-cycle arrest. We have cloned the Schizosaccharomyces pombe cdc23 gene by complementation of the temperature-sensitive phenotype of cdc23-M36 and confirmed the identity of the gene by integrative mapping. Analysis of the DNA sequence reveals that cdc23 can encode a protein of 593 amino acids (Mr=67 kDa) with 22% overall identity and many structural homologies with the product of the Saccharomyces cerevisiae DNA43 (MCM10) gene which is required for correct initiation of DNA synthesis at chromosomal origins of replication. Construction of a cdc23 null allele has established that the cdc23 gene is essential for viability, with cdc23 deletion mutant spores germinating but undergoing arrest with undivided nuclei in the first or second cell cycle. The S. pombe cdc23 gene on an expression plasmid is able to complement the S. cerevisiae dna43-1 mutant. These structural and functional homologies between two distantly related species suggest that cdc23 and DNA43 may represent genes for a conserved essential eukaryotic DNA replication function.

The rupture rate of acute flexor tendon repairs mobilized by the controlled active motion regimen

A series of 233 patients with complete divisions of flexor tendons in zones 1 and 2 underwent operation following emergency admission over a period of 3.5 years. These included 203 patients with 317 divided tendons in 224 fingers injuries in zones 1 and 2 and 30 patients with 30 complete divisions of the flexor pollicis longus tendon in zones 1 and 2. All of these patients were mobilized post-operatively in a controlled active motion regimen. 13 (5.8%) fingers and five (16.6%) thumbs suffered tendon rupture during the post-operative period. Patients treated during the last year of the study were followed prospectively for a minimum period of 3 months; ten of the 16 (62.5%) fingers with zone 1 repairs, 50 of the 63 (79.4%) fingers with zone 2 repairs, all three (100%) FPL divisions in zone 1 and three of four (75%) FPL divisions in zone 2 had good and excellent results on assessment by the original Strickland criteria (Strickland and Glogovac, 1980). These results confirm the safety of this regimen as an alternative to other regimens of post-operative flexor tendon repair mobilization in zone 1 and 2 finger injuries. However, in the unmodified form used in this series, this regimen has too high a rupture rate for FPL mobilization.

Thin bipolar leads: a solution to problems with coaxial bipolar designs

A new type of bipolar lead has been designed to be thinner and more reliable than the standard coaxial design. The new lead has passed numerous bench tests to ensure its reliability. Improved fatigue performance was shown during comparisons between the new type of coil (bifilar DFT [drawn filled tube]) and previous standard coils (trifilar MP35N). During the initial animal studies no reliability concerns were raised and stable electrode thresholds were measured. If success in the test process of this lead continues, a bipolar lead may soon be marketed with a size and reliability comparable to unipolar leads.