Characterization of polymeric proteins from vitreous and floury sorghum endosperm.

Differences in protein content and composition between vitreous and floury endosperm were investigated using a number of different techniques. Differences in protein cross-linking between vitreous and floury endosperm were investigated using differential solubility, size exclusion chromatography (SEC), and analysis of sulfhydryl content and composition. Vitreous endosperm was found to have higher levels of total protein and kafirins, but floury endosperm had a higher proportion of gamma-kafirins than the vitreous. Floury endosperm was found to have higher levels of SDS-soluble proteins than SDS-insoluble proteins extracted using sonication than vitreous endosperm. Conversely, vitreous endosperm had a greater proportion of the insoluble proteins. SEC analysis of the polymeric proteins revealed that the insoluble proteins had more polymeric proteins than did the soluble proteins, indicating greater cross-linking and a larger Mw distribution. Vitreous endosperm was also found to have a greater percentage (i.e., a higher ratio of disulfide to total sulfhydryls) of disulfide bonds than floury endosperm. These results show that the proteins in vitreous endosperm have a higher degree of cross-linking and a greater Mw distribution than those found in floury endosperm.

A biomechanical strength comparison of external fixators.

BACKGROUND: The purpose of this study was to biomechanically test the current commercially available uniplanar, half-pin external fixators, comparing stiffness, weight, and cost. METHODS: The Hammer, HexFix, Hoffmann, Monotube Blue, Monotube Red, Torus, TraumaFix, and Ultra-X were tested using previously published methods. The Instron 4500 was used to assess the strength characteristics in axial, torsional, anteroposterior, and lateral bending of each device. Weight was based on the unassembled fixator construct. Cost was determined from the purchase price of each individual fixator. RESULTS: The results of this study revealed that the Torus was the stiffest external fixator tested in torsion. The Monotube Red was the stiffest in axial loading, anteroposterior bending, and lateral bending. The Hammer and Hoffmann external fixators were the heaviest constructs. The Torus and HexFix were the most expensive. CONCLUSION: Many factors, including stiffness, weight, cost, ease of application, fracture characteristics, and personal preference, go into deciding which external fixator to use. The data presented compare stiffness characteristics of several fixators under standardized loading conditions. These data indicate that the Torus and Monotube Red provide the greatest stiffness when comparing all modes of failure.

Treatment of comminuted subtrochanteric femoral fractures in a young population with a reconstruction nail.

The authors report their experience using the Russell-Taylor reconstruction intramedullary interlocking nail in five comminuted subtrochanteric fractures in young paratroopers. The retrospective case series presented demonstrates the usefulness of this device for a challenging problem. Follow-up averaged 22 months and clinical results were good in that all soldiers could return to parachuting. The authors discuss surgical techniques and review the literature. The authors recommend consideration of the reconstruction nail use for this clinical problem.

Transfer of sequence tagged site PCR markers between wheat and barley.

Transfer of mapping information between related species has facilitated the development of restriction fragment length polymorphism (RFLP) maps in the cereals. Sequence tagged site (STS) primer sets for use in the polymerase chain reaction may be developed from mapped RFLP clones. For this study, we mapped 97 STS primer sets to chromosomes in wheat and barley to determine the potential transferability of the primer sets and the degree of correspondence between RFLP and STS locations. STS products mapped to the same chromosome group in wheat and barley 75% of the time. RFLP location predicted STS location 69% of the time in wheat and 56% of the time in barley. Southern hybridizations showed that most primer sets amplified sequences homologous to the RFLP clone, although additional sequences were often amplified that did not hybridize to the RFLP clone. Nontarget sequences were often amplified when primer sets were transferred across species. In general, results suggest a good probability of success in transferring STSs between wheat and barley, and that RFLP location can be used to predict STS location. However, transferability of STSs cannot be assumed, suggesting a need for recombinational mapping of STS markers in each species as new primer sets are developed. Key words : sequence tagged sites, PCR, wheat, barley.

STS-PCR markers appropriate for wheat-barley introgression.

Introgression of chromosomal segments across large taxonomic distances has long been an objective of scientists interested in understanding the relationships between genes and their effect on phenotype. Barley and wheat represent cultivated members of the Triticeae with different zones of adaptation, different responses to pathogens, and different end-use characteristics. Introduction of small, well-characterized chromosomal segments among grass relatives presents an opportunity to both better understand how genes perform in novel genomic environments and to learn more about the evolutionary novelties which differentiate related species. Since the distribution of the wheat-barley addition lines, the potential power and value of a comprehensive series of wheat/barley translocation lines has been widely appreciated. A scarcity of easy-touse markers which unambiguously distinguish barley loci from their wheat homologues has limited the ability of scientists to identify the relatively rare inter-chromosomal recombination events which are the necessary antecedents of these lines. Since the single most critical pathogen affecting U.S. wheat producers is Karnal bunt (Tilletia indica) and since barley carries a gene conferring immunity, molecular markers may prove practically and immediately important. In this report we describe a series of 135 barley-specific markers amplified by 115 primer sets developed from sequences from previously mapped restriction fragment length polymorphism (RFLP) markers. These easily distinguish the cognate barley products from their wheat counterparts and should find ready use in the identification of lines which contain wheat/barley translocation events.

A retrospective analysis of open fractures sustained by U.S. military personnel during Operation Just Cause.

A retrospective analysis was conducted of 37 open fracture cases sustained by U.S. military personnel during the recent low-intensity conflict in Panama (Operation Just Cause). The etiology, location, classification, and management of open fractures sustained in combat is presented. A significant difference was noted in the infection rate for type III open fractures that were debrided in Panama (22%) as compared to those that were debrided only after transport to CONUS (66%). This study supports the critical importance of adequate battlefield surgical support in low-intensity conflicts, and reemphasizes the crucial role of early surgical debridement for the prevention of wound infection.

Intracranial amebic abscesses: CT and MR findings.

The CT and magnetic resonance findings in a case of intracranial amebic abscesses are described. Due to increased travel to endemic areas, amebic abscess should also be included in the differential diagnosis for patients who live in the temperate parts of the world.