Evaluation of bovine-derived bone protein with a natural coral carrier as a bone-graft substitute in a canine segmental defect model

The efficacy of a bone-graft substitute (bovine-derived bone protein in a carrier of natural coral) in the healing of a segmental defect of a weight-bearing long bone was evaluated. Twenty dogs, divided into two groups, underwent bilateral radial osteotomies with creation of a 2.5 cm defect. On one side of each dog, the defect was filled with autogenous cancellous bone graft. Contralateral defects received, in a blinded randomized fashion, cylindrical implants consisting of natural coral (calcium carbonate) or calcium carbonate enhanced with a standard dose of bovine-derived bone protein (3.0 mg/implant; 0.68 mg bone protein/cm3). The limbs were stabilized with external fixators, and all animals underwent monthly radiographs. They were killed at 12 (group 1) or 24 (group 2) weeks, and regenerated bone was studied by biomechanical testing and histology. Radiographic union developed in all 20 radii with autogenous cancellous bone grafts and in all 10 of the radii with the composite implants. None of the radii with implants of calcium carbonate alone showed radiographic evidence of union. This represented a statistically significant difference between implant types. In addition, calcium carbonate implants both with and without bone protein demonstrated radiographic evidence of near total resorption of the radiodense carrier by 12 weeks. This resorption facilitated radiographic evaluation of healing. Mean values for biomechanical parameters of radii with the composite implants exceeded those for the contralateral controls at 12 and 24 weeks; the difference was statistically significant at 12 weeks. Histology revealed scant residual calcium carbonate carrier at either time in the defects with calcium carbonate implants; however, a moderate amount was present in defects with the composite implants. In these specimens, the residual carrier was completely surrounded by newly formed bone that may have insulated the calcium carbonate from further degradation. The present study used a carrier of granular calcium carbonate reconstituted with bovine type-I collagen to deliver an osteoinductive protein to the defect site. This carrier is of nonhuman origin (eliminating the risk of disease transmission or antigenicity) and resorbs rapidly. In this model, bovine-derived bone protein in a natural coral carrier performed consistently better than the gold standard autogenous cancellous bone graft in terms of the amount of bone formation and strength of the healed defect. This may have implications for removal of hardware or resumption of weight-bearing in certain clinical situations. These data also indicate that coralline calcium carbonate alone represents a poor option as a bone-graft substitute in this critical-sized segmental defect model.     

Testosterone and child and adolescent adjustment: The moderating role of parent-child relationships.

In a sample of established middle- and working-class families with normally developing children and adolescents ranging in age from 6 to 18 years, sons' and daughters' testosterone levels showed little direct connection to risk behavior or symptoms of depression. In contrast, testosterone's positive relation with risk behavior and negative relation with depression were conditional on the quality of parent-child relations. As parent-child relationship quality increased, testosterone-related adjustment problems were less evident. When relationship quality decreased, testosterone-linked risk-taking behavior and symptoms of depression were more in evidence. Few relations were found between parents' testosterone and child behavior. Boys' and girls' ages and stages of pubertal development were important for understanding the expression of hormone-related problem behavior in some cases but not in others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hybrid valve structure for high-throughput, low-volume liquid-handling applications

A hybrid valve that integrates precision microfluidics for fluid routing, high-speed valving for fluid switching, and reagent-jetting devices for metering the fluid dispenses is described. The hybrid valve enables parallel switching between aspiration and dispense modes for multiple sample streams. This unique valve structure addresses many of the concerns with handling microscale volumes, including efficient use of samples, degradation of ink jet valves and speed of operation. A broad range of volumes can be manipulated with excellent reproducibility. The hybrid valve can be configured for a variety of applications. Pick-and-place aspiration and dispensing of unique reagents and rapid dispensing of a common reagent are possible. Together these features lead to higher-speed transfer of smaller volumes of reagent.     

Effects of Conjugated Linoleic Acid, Salt, and Sodium Tripolyphosphate on Physical, Sensory, and Instrumental Color Characteristics of Beef Striploins

ABSTRACT:  USDA Select striploins (IMPS 180; n = 24) were cut into thirds (anterior, medial, and posterior) and assigned to 1 of 8 treatments utilizing a randomized incomplete block design. Treatments included (1) control (C); (2) 1.5% conjugated linoleic acid (conjugated linoleic acid = CLA) (CGA); (3) 0.4% sodium tripolyphosphate (PHO); (4) 0.5% salt (SAL); (5) 0.4% sodium tripolyphosphate, 0.5% salt (SPH); (6) 0.4% sodium tripolyphosphate, 1.5% CLA (PCL); (7) 0.5% salt, 1.5% CLA (SCL); and (8) 0.4% sodium tripolyphosphate, 0.5% salt, 1.5% CLA (SPC). Treatments were injected with solutions to 110% (10% pump) of their original weight. Treatments with CLA had higher ( P < 0.05) marbling scores than treatments that did not. Not including SAL, treatments with salt, or phosphate or a combination of the two had higher tenderness values when sampled by panelists. Fresh steaks with inclusion of CLA had greater amounts ( P < 0.05) of the CLA isomers than steaks not having CLA. Cooked steaks having CLA also had greater amounts ( P < 0.05) of CLA, except for SCL, which were not different ( P > 0.05) from the non-CLA treatments. Day was a significant source of variability for a *, b *, and saturation index. Treatment × day interactions were significant ( P < 0.05) for hue angle and L * values. These data suggest that inclusion of CLA can increase amounts of CLA isomers without major deleterious effects to instrumental, physical, and quality characteristics of beef striploin steaks.     

A theoretical and experimental investigation into asymmetrical hot rolling

A simple slip-line field solution for asymmetrical hot rolling is investigated and used to predict the sign and magnitude of the curvature of the rolled strip. These predictions are compared with measurements from a two high model rolling mill.     

A modular approach to computerized material balance calculations

The problem of determining material requirements is an important one in any integrated manufacturing organization. This paper presents an approach to the computer calculation of material requirements and balances. The approach is particularly useful in planning applications where it is desired to evaluate numerous alternatives. It also forms a means of generating matrices for linear programming optimizations. The approach identifies particular types of calculations which can be written as subroutines in a computer program. Each subroutine can be represented by a particular name and symbol, thus becoming a module which can be used as a building block in a material balance calculation system. To model a particular material flow complex, an information flow diagram is drawn in which each calculation module is represented by a block. Directed lines connecting the blocks represent streams of information flow. The information flow diagram can be readily coded for computer case-study simulations using a unique application-oriented language.     

Vibration-RF Control of Superconducting-Helix Resonators for Heavy-Ion Acceleration

An electronic system for the control of the effects of RF frequency oscillations caused by mechanical vibrations in a superconducting helix are described. A combination of frequency modulation and amplitude modulation is used to lock the phase of a self-excited accelerating structure to that of a controlling master oscillator. The system has been used successfully during beam acceleration with a superconducting helix.     

Portal hypertension changes following selective splenorenal shunt surgery. Evaluation by percutaneous transhepatic portal catheterization, venography, and cinefluorography

A series of ergot alkaloids, together with the DA agonists apomorphine and piribedil, were tested for protective effects against audiogenic seizures in an inbred strain of mice (DBA/2) and for induction of circling behaviour in mice with unilateral destruction of one nigrostriatal DA pathway. The order of potency against audiogenic seizures was apomorphine greater than ergocornine greater than bromocryptine greater than ergometrine greater than LSD greater than methysergide greater than piribedil while that observed in the rotating mouse model was apomorphine greater than ergometrine greater than ergocornine greater than bromocryptine greater than piribedil. LSD caused only weak circling behaviour even when administered in high doses (greater than 1 mg/kg). Methysergide was ineffective. Prior administration of the neuroleptic agent haloperidol blocked the effect of DA agonists and of ergot alkaloids in both animal models. The possible action of ergot alkaloids as DA agonists is discussed.     

Chemical reactions at lipid-gas interfaces: I. Terminal chain elongation of fatty acids

Reactions of free methyl radicals and monolayers of potassium palmitate and of potassiumn-heptadecanoate on an aqueous surface yielded straight chain saturated fatty acids containing longer hydrocarbon chains than those of the reactant acids. Similar results were obtained from the reactions of free ethyl radicals and potassium palmitate under similar conditions. The results of this investigation indicate that extension of hydrocarbon chains by free radical addition reactions can be achieved if the growing chains are suitably packed in a monolayer on a surface.