Bioabsorbable fixation of scaphoid fractures and non-unions; analysis of early clinical outcomes.

The vast majority of devices used for internal fixation of the scaphoid are metallic. This two-center study aimed to report the results of scaphoid fixation using a cannulated, bioabsorbable device made from a hydroxyapatite and poly-L-lactide composite in 29 consecutive patients. Fixation was performed for seven acute fractures and twenty-two established non-unions. Union was achieved in 72.4% of patients. Six of the acute fractures and fifteen of the non-unions united successfully. Modified Mayo Wrist Score ranged between good to excellent in all patients who successfully united, whereas patients who failed to unite ranged between poor to excellent, with one poor and two moderate scores. No adverse biocompatibility reactions were seen. Two failures with broken screws were re-explored and one of these was thought to be due to screw mal-placement. The device used is an alternative to conventional metal implants and produces comparable union rates to metallic devices in the short term.

Nutritional and physical characteristics of commercial hand-feeding formulas for parrots.

Hand-rearing is a common practice for the propagation of captive psittacines, however, research on their nutrition is limited and the requirements of growing chicks are not well understood. The nutrition of 15 commercially available parrot hand-feeding formulas was compared with the average content of the crops of free living Scarlet Macaw (Ara macao) chicks, as well as with the requirements of 6- to 12-week-old leghorn chickens. When the formulas were prepared for a 1-week-old chick, all except three maintained >90% of solids in suspension after 15 min and >60 after 30 min. On average the formulas had a similar metabolizable energy density as wild macaw crop samples. The concentration of crude protein in the formulas was higher than that of the crop sample average, while the crude fat was lower than the average crop samples. More than 50% of the formulas had concentrations of K, Mg, and Mn less than the crop sample average, and Ca and Na concentrations below the requirements established for 6- to 12-week-old leghorn chickens. For >45% of the formulas the concentrations of arginine, leucine, and methionine + cystine were below the requirements of 6- to 12-week leghorns. When commercial formulas were prepared according to the manufacturer's instructions, the different dilutions greatly magnified the nutritional differences among them. Overall, the inconsistency in the nutrient concentrations among the formulas suggests that there is no consensus among manufacturers of the correct nutrition for growing psittacines and the industry could benefit from continued research in this area.

Biomechanical evaluation of a new composite bioresorbable screw.

A new bioresorbable composite cannulated screw has been developed for small bone fracture fixation. The LG ("Little Grafter") screw is manufactured from Biosteon, which is a composite of poly L-lactic acid and hydroxyapatite. This study aimed to compare interfragmentary compression generated by this new screw with conventional metal screws commonly used in scaphoid fracture fixation. Four small metallic screws were compared with the LG screw, using a bone model produced from rigid polyurethane foam. The screws included the Acutrak, Asnis III, Herbert and Herbert-Whipple screws. The mean maximum compression forces for the LG screw, the Asnis and the Acutrak were comparable (LG 32.3 N, Asnis 32.8 N, Acutrak 38.3 N), whereas those using the Herbert and the Herbert-Whipple screw were significantly lower (Herbert 21.8 N, Herbert-Whipple 19.9 N). The bioresorbable LG screw has been shown to have good compressive properties compared to commonly used small bone fragment compression screws.

Generalized epilepsy in hypothalamic hamartoma: evolution and postoperative resolution.

OBJECTIVE: To better understand the epileptogenesis of symptomatic generalized epilepsy in patients with hypothalamic hamartoma and intractable epilepsy, many of whom experience remission of generalized seizures and slow spike-wave discharges following surgery. METHODS: The authors documented the evolution of symptomatic generalized epilepsy in 12 of 20 children who underwent transcallosal microsurgical hypothalamic hamartoma resection. In seven patients they recorded intraoperative EEG from the hamartoma and simultaneously from the scalp and frontal cortex before, during, and after resection. RESULTS: Gelastic seizures began on average at 6 months of age (range birth to 3 years); tonic seizures began at 6 years (range 2 months to 9 years). Normal EEG were reported in early childhood; thereafter, abnormalities were progressive. Interictal spike-wave was recorded intraoperatively over the scalp and cortex in six patients, but not from the hypothalamic hamartoma. Hamartoma resection had no immediate effect on cortical spike-wave, but waking spike-wave was absent in seven patients on subsequent postoperative EEG. Tonic seizures ceased in 11 of 12 patients, but 6 of these had postoperative generalized seizures that resolved over 1 to 6 months. CONCLUSION: Gelastic seizures in hypothalamic hamartoma arise from the hamartoma itself; the interictal spike-wave does not. The evolution of EEG abnormalities, the development of generalized seizures years after onset of gelastic seizures, and the postoperative running down of interictal spike-wave and generalized seizures in these patients may reflect secondary epileptogenesis.

Porcine dermal collagen graft in abdominal-wall reconstruction.

We describe the use of a porcine dermal collagen graft in the reconstruction of a large abdominal-wall defect in a woman. The graft was not rejected and, after 1 year, was not associated with incisional hernia. This graft may become an alternative to synthetic-mesh and flap reconstructions because, despite being of a similar tensile strength, it promotes less adhesion, is incorporated into the host tissue and is less prone to infection.

Knowledge, attitudes, and interest in breast-ovarian cancer gene testing: a survey of a large African-American kindred with a BRCA1 mutation.

BACKGROUND: This study assessed counseling and testing needs from the perspective of adult members of a large African-American kindred with a BRCA1 mutation. METHODS: Interviews were conducted with 95 male and female kindred members to elicit information on sociodemographics, attitudes toward health care providers, breast cancer screening behaviors, and religious/spiritual beliefs, as well as to evaluate psychological distress, beliefs, knowledge, and attitudes related to genetic testing. RESULTS: Knowledge about breast and ovarian cancer genetics was limited. Adherence to screening recommendations was low among females with no personal breast or ovarian cancer history. The majority (67%) wished to discuss risk factors with a health care provider. Most participants (82%) indicated that they would have a genetic test if it were available. Significant predictors of intent to undergo testing were having at least one first-degree relative with breast and/or ovarian cancer (OR = 5.1; 95% CI = 1.2-20.9) and perceived risk of being a gene carrier > or =50% (OR = 64.3; 95% CI = 5.1-803.9) or reporting that they did not know their risk of being a gene carrier (OR = 10.9; 95% CI = 2.1-57.7). Cited barriers to testing included cost and availability. CONCLUSION: There is a high interest level in genetic testing despite limited knowledge about cancer genetics among these high-risk African Americans. Our study provides information for designing a genetic education and counseling intervention for this and similar families.

Use of expander cottonseed meal in broiler diets formulated on a digestible amino acid basis.

This experiment was designed to evaluate the use of expander cottonseed meal (CSM) in broiler diets formulated on a digestible amino acid basis and to determine the tissue distribution of gossypol enantiomers and their relationship to gossypol consumption. Gossypol is an antinutritional polyphenolic pigment found in cottonseed. A total of 800 1-d-old broilers (Arbor Acres) was randomly divided into 40 groups of 20 birds each and placed in a broiler house with wood shavings litter. The CSM was included in starter and grower diets at 0, 7, 14, 21, and 28% of the diet. Diets were formulated to have similar levels of digestible methionine and lysine as the 0% CSM control diet. At 21 d of age, five birds per pen were randomly selected for the determination of gossypol enantiomers in plasma, liver, heart, and breast muscle. Tissues were again collected at 42 d of age. Results of this experiment indicated that at 21 d of age cumulative body weight and feed-to-BW ratios of birds fed CSM diets were not significantly different from the control. By 35 d of age, feed-to-BW ratios of experimental birds fed the 28% CSM diet were significantly greater than the control birds, and by 42 d, BW were lower than those of the control group. Tissue concentrations of total, (+) and (-) gossypol increased linearly as the level of CSM increased. At 42 d, liver had the most gossypol with a ratio of 87% (+) gossypol to 13% (-) gossypol. Plasma contained 73% (+) gossypol and 27% (-) gossypol. Heart contained 45% (+) gossypol and 55% (-) gossypol. Breast muscle had the least gossypol. Results of this experiment indicated that expander solvent CSM could be fed to broilers at up to 21% of the total diet if amino acid digestibility was considered.

Effect of beta-carotene, canthaxanthin, or lutein on lymphocyte proliferation (in vitro) of newly hatched chicks.

The aim of this study was to determine the effect of beta-carotene, canthaxanthin, and lutein on lymphocyte proliferation (in vitro) of newly hatched chicks. Tetrahydrofuran (THF) was used as the vehicle to introduce carotenoids in the culture media. So, we also determined effect of THF on viability of cells. The viabilities of fibroblast cells at 10(-3) dilution were 98% and 96% after 24 and 48 hr of incubation. Therefore, 10(-3) (v/v) THF dilution was decided upon as the vehicle to introduce carotenoids in culture media. Chick bursal lymphocytes were incubated in the presence or absence of beta-carotene, canthaxanthin, or lutein and stimulated with phorbol 12, 13-dibutyrate. The results of this experiment suggested that THF rather than the carotenoids stimulated bursal lymphocyte proliferation. The mechanism by which THF acted as a mitogen is not known. We conclude from this study that beta-carotene, canthaxanthin, and lutein are not effective in enhancing in vitro bursal lymphocyte proliferation at concentrations of less than 10(-6) M in the presence of THF.

Effect of beta-carotene, canthaxanthin, lutein, and vitamin E on neonatal immunity of chicks when supplemented in the broiler breeder diets.

The study was designed to assess neonatal immunity of chicks hatched from breeders fed diets supplemented with beta-carotene, canthaxanthin, lutein, or vitamin E. Broiler breeder birds were fed experimental diets consisting of control, 0.04% beta-carotene, 0.04% canthaxanthin, 0.04% lutein, 0.03% alpha-tocopherol acetate, or 0.04% beta-carotene plus 0.03% alpha-tocopherol acetate. Three weeks after initiation of experimental feeding, birds were vaccinated against Newcastle disease virus. Chicks hatched from the eggs of these breeders were used to determine the neonatal immune responses. There were no significant differences in weight gain and antibody titers of 3-wk-old chicks. 3H-Thymidine uptake by bursal lymphocytes when stimulated with tetrahydrofuran was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E, or vitamin E plus beta-carotene, than in controls. 3H-Thymidine uptake by splenic lymphocytes when stimulated with concanavalin A and phorbol 12-myristate 13 acetate was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E or beta-carotene alone, or vitamin E plus beta-carotene, than for the control chicks. Chicks hatched from hens supplemented with vitamin E had significantly higher antibody titers at 1 and 7 d of age than chicks from the control group. Vitamin E supplementation of breeder birds increased the immune response of their progeny.

Redox modification of sodium-calcium exchange activity in cardiac sarcolemmal vesicles.

Na-Ca exchange activity in bovine cardiac sarcolemmal vesicles was stimulated up to 10-fold by preincubating the vesicles with 1 microM FeSO4 plus 1 mM dithiothreitol (DTT) in a NaCl medium. The increase in activity was not reversed upon removing the Fe and DTT. Stimulation of exchange activity under these conditions was completely blocked by 0.1 mM EDTA or o-phenanthroline; this suggests that the production of reduced oxygen species (H2O2, O2-.,.OH) during Fecatalyzed DTT oxidation might be involved in stimulating exchange activity. In agreement with this hypothesis, the increase in exchange activity in the presence of Fe-DTT was inhibited 80% by anaerobiosis and 60% by catalase. H2O2 (0.1 mM) potentiated the stimulation of Na-Ca exchange by Fe-DTT under both aerobic and anaerobic conditions; H2O2 also produced an increase in activity in the presence of either FeSO4 (1 microM) or DTT (1 mM), but it had no effect on activity by itself. Superoxide dismutase did not block the effects of Fe-DTT on exchange activity; however, the generation of O2-. by xanthine oxidase in the presence of an oxidizable substrate stimulated activity more than 2-fold. Hydroxyl radical scavenging agents (mannitol, sodium formate, sodium benzoate) did not attenuate the stimulation of activity observed with Fe-H2O2. Exchange activity was also stimulated by the simultaneous presence of glutathione (GSH; 1-2 mM) and glutathione disulfide (GSSG; 1-2 mM). Neither GSH nor GSSG was effective by itself and either 0.1 mM EDTA or o-phenanthroline blocked the effects on transport activity of the combination of GSH + GSSG. Treatment of the GSH and GSSG solutions with Chelex ion-exchange resin to remove contaminating transition metal ions reduced (by 40%) the degree of stimulation observed with GSH + GSSG. Full stimulating activity was restored to the Chelex-treated GSH and GSSG solutions by the addition of 1 microM Fe2+; Cu2+ was less effective than Fe2+ whereas Co2+ and Mn2+ were without effect. In the presence of 1 microM Fe2+, GSH alone produced a slight increase in transport activity, but this was markedly enhanced by the addition of Chelex-treated GSSG. The results indicate that stimulation of exchange activity requires the presence of both a reducing agent (DTT, GSH, O-.2, or Fe2+) and an oxidizing agent (H2O2, GSSG, and perhaps O2) and that the effects of these agents are mediated by metal ions (e.g. Fe2+).(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of DEAE-dextran on infection and hemolysis by VSV. Evidence that nonspecific electrostatic interactions mediate effective binding of VSV to cells.

The polycation DEAE-dextran increased the binding of VSV to BHK cells about fourfold over a wide range of VSV concentrations. The same proportion of bound virions was internalized by the cell in the presence or absence of DEAE-dextran. Viral primary RNA production was increased to the equivalent of a 4- to 4.5-fold increase in multiplicity of infection in the presence of DEAE-dextran, closely paralleling the increase in total VSV binding to the cell. Viral secondary RNA production was increased only to the equivalent of about twofold increase in multiplicity. The kinetics of both primary and secondary RNA production were indistinguishable in the presence or absence of DEAE-dextran. DEAE-dextran had to be present simultaneously with the input virions in order to enhance RNA production; addition even 30 min after infection was ineffective. Addition of the polycation DEAE-dextran was also required for appreciable VSV-induced hemolysis of human erythrocytes; erythrocytes of several other species were hemolyzed in the absence of DEAE-dextran, but hemolysis was enhanced by its presence. Maximal binding and hemolysis occurred at pH 5.0 and 37 degrees. Vesicles containing only G protein and viral lipid were 40% as hemolytic as intact virions at pH 5.0, but were inactive at pH 6.0; "spikeless" virions lacking G, or protein-free viral lipid vesicles were not hemolytic, showing that G protein is necessary for hemolysis. These results, together with other recent observations, suggest that multiple electrostatic interactions between VSV and the cell surface, rather than an affinity for specific surface molecules, mediated the productive (infection producing) binding of VSV to the cell surface.

Inhibitory effect of solar radiation on amino Acid uptake in chesapeake bay bacteria.

The effect of solar radiation on a natural bacterial population from the Chesapeake Bay was evaluated from measured changes in numbers of organisms engaged in amino acid uptake. From July through May, freshly collected water samples were exposed in quartz containers to 3.5 h of total sunlight both with and without UV-absorbing filters. Water samples were subsequently incubated with tritiated amino acids, and the uptake-active bacteria were assayed by microauto-radiography-epifluorescence microscopy. The survival index, defined as the fraction of the uptake-active population that remained active after the exposure to sunlight, ranged from 0.93 to 0.20. Decreased survival was correlated with increased solar intensity. The inhibition of amino acid uptake was attributed not only to the UV-B component of the solar spectrum (280 to 320 nm), but also to longer UV and visible wavelengths.

Biocidal properties of anti-icing additives for aircraft fuels.

The biocidal and biostatic activities of seven glycol monoalkyl ether compounds were evaluated as part of an effort to find an improved anti-icing additive for jet aircraft fuel. Typical fuel contaminants, Cladosporium resinae, Gliomastix sp., Candida sp., Pseudomonas aeruginosa, and a mixed culture containing sulfate-reducing bacteria were used as assay organisms. Studies were carried out over 3 to 4 months in two-phase systems containing jet fuel and aqueous media. Diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and 2-methoxyethanol were generally biocidal in aqueous concentrations of 10 to 17% for all organisms except Gliomastix, which required 25% or more. 2-Ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol were biocidal at progressively lower concentrations down to 1 to 2% for 2-butoxyethanol. The enhanced antimicrobial activity of these three compounds was attributed to cytoplasmic membrane damage because of the correlation between surface tension measurements and lytic activity with P. aeruginosa cells. The mechanism of action of the less active compounds appeared to be due to osmotic (dehydrating) effects. When all requirements are taken into account, diethylene glycol monomethyl ether appears to be the most promising replacement for the currently used additive, 2-methoxyethanol.