40 research outputs found

    Association of radial longitudinal deficiency and thumb hypoplasia: An update using the CoULD registry

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    BACKGROUND: Deficiency of the radial aspect of the forearm and hand is the most common congenital longitudinal deficiency of the upper limb. Radial longitudinal deficiency is associated with several named syndromes. The purpose of the present study was to explore patterns of radial longitudinal deficiency and thumb hypoplasia in syndromes and to examine the severity of these differences across various syndromes. METHODS: Data were collected from the Congenital Upper Limb Differences (CoULD) registry. Congenital differences are classified in the registry with use of the Oberg-Manske-Tonkin (OMT) classification system. Diagnosis of a syndrome by a physician as noted in the CoULD registry was recorded. Thumb deficiency and radial deficiency were classified according to the modified versions of the Blauth criteria and the Bayne and Klug criteria, respectively. RESULTS: We identified 259 patients with 383 affected limbs with radial deficiency. Eighty-three of these patients had a diagnosed syndrome. The severity of radial deficiency was correlated with the severity of thumb deficiency. The Kendall tau coefficient indicated significant correlation between radial severity and thumb severity (tau = 0.49 [95% confidence interval = 0.40 to 0.57]; p \u3c 0.05). Subjects with a syndrome were twice as likely to have bilateral deficiency and 2.5 times more likely to have both radial and thumb deficiency compared with subjects without a syndrome. Subjects with VACTERL syndrome (vertebral defects, anal atresia, cardiac anomalies, tracheoesophageal fistula, renal anomalies, and limb defects) had patterns of thumb and radial deficiency similar to the general cohort, whereas subjects with Holt-Oram syndrome, TAR (thrombocytopenia absent radius) syndrome, and Fanconi anemia demonstrated varied presentations of thumb and radial deficiency. CONCLUSIONS: The present study investigated the characteristics of patients with radial longitudinal deficiency and thumb hypoplasia. Our results support the findings of previous research correlating the severity of radial deficiency with the severity of thumb deficiency. Furthermore, we identified characteristic features of patients with radial longitudinal deficiency and associated syndromes

    Allelic variants of the amylose extender mutation of maize demonstrate phenotypic variation in starch structure resulting from modified protein–protein interactions

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    amylose extender (ae−) starches characteristically have modified starch granule morphology resulting from amylopectin with reduced branch frequency and longer glucan chains in clusters, caused by the loss of activity of the major starch branching enzyme (SBE), which in maize endosperm is SBEIIb. A recent study with ae− maize lacking the SBEIIb protein (termed ae1.1 herein) showed that novel protein–protein interactions between enzymes of starch biosynthesis in the amyloplast could explain the starch phenotype of the ae1.1 mutant. The present study examined an allelic variant of the ae− mutation, ae1.2, which expresses a catalytically inactive form of SBEIIb. The catalytically inactive SBEIIb in ae1.2 lacks a 28 amino acid peptide (Val272–Pro299) and is unable to bind to amylopectin. Analysis of starch from ae1.2 revealed altered granule morphology and physicochemical characteristics distinct from those of the ae1.1 mutant as well as the wild-type, including altered apparent amylose content and gelatinization properties. Starch from ae1.2 had fewer intermediate length glucan chains (degree of polymerization 16–20) than ae1.1. Biochemical analysis of ae1.2 showed that there were differences in the organization and assembly of protein complexes of starch biosynthetic enzymes in comparison with ae1.1 (and wild-type) amyloplasts, which were also reflected in the composition of starch granule-bound proteins. The formation of stromal protein complexes in the wild-type and ae1.2 was strongly enhanced by ATP, and broken by phosphatase treatment, indicating a role for protein phosphorylation in their assembly. Labelling experiments with [γ-32P]ATP showed that the inactive form of SBEIIb in ae1.2 was phosphorylated, both in the monomeric form and in association with starch synthase isoforms. Although the inactive SBEIIb was unable to bind starch directly, it was strongly associated with the starch granule, reinforcing the conclusion that its presence in the granules is a result of physical association with other enzymes of starch synthesis. In addition, an Mn2+-based affinity ligand, specific for phosphoproteins, was used to show that the granule-bound forms of SBEIIb in the wild-type and ae1.2 were phosphorylated, as was the granule-bound form of SBEI found in ae1.2 starch. The data strongly support the hypothesis that the complement of heteromeric complexes of proteins involved in amylopectin synthesis contributes to the fine structure and architecture of the starch granule

    Thoracolumbar injury classification and severity score: a new paradigm for the treatment of thoracolumbar spine trauma

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    BACKGROUND: Contemporary understanding of the biomechanics, natural history, and methods of treating thoracolumbar spine injuries continues to evolve. Current classification schemes of these injuries, however, can be either too simplified or overly complex for clinical use. METHODS: The Spine Trauma Group was given a survey to identify similarities in treatment algorithms for common thoracolumbar injuries, as well as to identify characteristics of injury that played a key role in the decision-making process. RESULTS: Based on the survey, the Spine Trauma Group has developed a classification system and an injury severity score (thoracolumbar injury classification and severity score, or TLICS), which may facilitate communication between physicians and serve as a guideline for treating these injuries. The classification system is based on the morphology of the injury, integrity of the posterior ligamentous complex, and neurological status of the patient. Points are assigned for each category, and the final total points suggest a possible treatment option. CONCLUSIONS: The usefulness of this new system will have to be proven in future studies investigating inter- and intraobserver reliability, as well as long-term outcome studies for operative and nonoperative treatment methods

    A Survey of DNA Polymorphism within the Genus Capsicum and the Fingerprinting of Pepper Cultivars

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    Interspecific genetic variation was examined in the genus Capsicum based on shared restriction fragments in Southern analyses. Four distinct clusters were delineated among 21 accessions of cultivated and wild pepper (C. annuum, C. baccatum, C. chacoense, C. chinense, and C. frutescens). Three tight clusters comprised of accessions belonging to C. annuum, C. frutescens, and C. baccatum, respectively, were formed, along with a fourth cluster comprised of one accession each of C. chinense and C. chacoense. All accessions were differentiated by this technique, and the clusters corresponded closely to previous morphology-based classification. Sufficient DNA polymorphism exists among these accessions that segregating populations useful for restriction fragment length polymorphism (RFLP) mapping could be constructed using any two pepper accessions as parents. Regression analysis indicates that genetic distance is a good predictor (R2 = 0.872) of the level of mappable DNA polymorphism in Capsicum. Intraspecific variability was examined among four C. annuum cultivars (NuMex R Naky, Jupiter, Perennial, and Criollo de Morelos 334) using both RFLPs and randomly amplified polymorphic DNA (RAPDs), allowing a comparative evaluation of the two techniques. Seventeen percent of the clones used singly in RFLP analyses were sufficient for the differentiation of these varieties, as were 12.5% of the RAPD PCR amplifications. Dendrograms constructed from RFLP and RAPD analyses of the intraspecific data are similar but not identical. Southern analysis and RAPD PCR should be useful for DNA fingerprinting and the discrimination of closely related C. annuum genotypes.Key words: cluster analysis, restriction fragment length polymorphism, RFLP, DNA fingerprinting, randomly amplified polymorphic DNA, RAPD, germplasm
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