Tumor necrosis factor alpha and interleukin 6 release induced by antibiotic killing of Pseudomonas aeruginosa and Staphylococcus aureus

OBJECTIVE: The purpose of this study was to determine the depth that implants may be safely placed into the distal femoral epiphysis (DFE) for the repair of distal femoral physeal fractures. STUDY DESIGN: The depth of the DFE was related to the radiographic thickness of the patella in this experimental study. ANIMALS OR SAMPLE POPULATION: Twenty immature canine cadavers. METHODS: Patella thicknesses were measured from lateral radiographs. Actual DFE depths were determined for pins driven in normograde fashion and for pins driven retrograde from the central depression between the metaphyseal pegs and from the cranial pegs. The association of DFE depth and patella thickness was evaluated using linear regression analysis. Using 95% confidence intervals, rules for estimating the safe depth of implant placement into the DFE were determined. RESULTS: DFE depth had significant correlation with patella thickness for pins placed in retrograde fashion from the central depression between the metaphyseal pegs (r2 = .83) and from the cranial pegs (r2 = .82) and for pins placed in normograde fashion (r2 = .65). CONCLUSIONS: Based on 95% confidence intervals, pins placed in retrograde fashion from the central depression between the metaphyseal pegs may be safely driven into the DFE a distance equal to 140% of patella thickness. Pins placed from the cranial metaphyseal pegs may be driven to a depth equal to 80% of patella thickness, and pins placed in normograde fashion may be driven to a depth equal to 30% of patella thickness. CLINICAL RELEVANCE: Measurement of patella thickness assists the surgeon in determining the approximate depth that pins may be driven into the DFE without penetrating the articular surface of the stifle joint.     

Influence of materials and structure on performance of a football helmet

A nonlinear finite element model for the static analysis of football helmets is developed as a first step in a methodology for the mathematical modeling of helmets. Polycarbonate and acrylonitrile-butadiene-styrene are considered as the shell material for the helmet. Such a methodology can be used to predict helmet response to loading and impact and can be incorporated in a computer program studying injuries caused by helmeted head collisions in football. Numerical results in terms of force-deflection curves, maximum stresses, and work of deformation are given. The influence of the polymeric material forming the helmet shell on energy absorption is studied. The effect of the internal padding material and suspension system is also considered.     

The effect of saralasin (1sar-8-ala-angiotensin II) on blood pressure in patients with Cushing's syndrome

To investigate the role of the renin angiotensin system in the pathogenesis of hypertension in Cushing's syndrome two patients with hypercorticism were infused with 20 mg saralasin (1-sar-8-ala-angiotensin II) over a period of 30 minutes under constant blood pressue control. In addition, one patient with primary aldosteronism, an established form of mineralocorticoid hypertension, served as control. Neither in the two patients with Cushing's syndrome nor in the patient with primary aldosteronism could a blood pressure lowering effect of saralasin be observed. In the two patients with hypercoritcism both renin activity and plasma aldosterone increased during saralasin infusion. The patient with primary aldosteronism only showed a weak increase in plasma aldosterone concentration.     

Überblick über Verfahren zur Prüfung der Zähigkeit hochfester Stähle

Überblick über die wichtigsten Verfahren zur Kennzeichnung des Bruchverhaltens hochfester Stähle mit einer Streckgrenze über 120 kg/mm² unter besonderer Berücksichtigung der Ermittlung ihrer Bruchzähigkeit. Möglichkeiten und Anwendung der linearen Bruchmechanik für die Voraussage des Werkstoffverhaltens im Bauteil unter Berücksichtigung verschiedener Beanspruchungsbedingungen.     

Halogenated natural products in five species of Antarctic sponges: compounds with POP-like properties?

Purified extracts of five species of Antarctic sponges (Demospongiae: Kirkpatrickia variolosa, Artemisina apollinis, Phorbas glaberrima, and Halichondria sp. and Calcarea: Leucetta antarctica) from King George Island were analyzed by GC/MS for the presence of persistent and lipophilic halogenated compounds to identify bioaccumulative halogenated natural products. Sample extracts were prepared using methods identical for the determination of POPs, namely, microwave-assisted extraction with organic solvents, gel permeation chromatography, and column chromatography on deactivated silica. In addition, samples were treated with sulfuric acid to remove acid-destructible compounds. PCBs were not detectable and only traces of lindane, p,p'-DDE, and alpha-HCH were detected in these samples in decreasing order of abundance, underscoring their uncontaminated state. In contrast, 146 brominated compounds were identified by correct isotopic ratios m/z 79 and 81, 50% of which eluted prior to lindane including the most abundant peaks. Each sponge sample contained > or = 35 brominated compounds of natural origin, 14 of which were detected in all species. Estimated concentrations ranged from the high ng/kg to mg/kg (air-dried weights) and relative distributions of the same compounds in different sponges were highly variable. The high abundance of these compounds relative to known anthropogenic pollutants strongly suggests a natural origin. Multiple mode (EI-, ECNI-, and PCI-) GC/MS enabled identification of an aliphatic ketone tentatively identified as 1,1,2-tribromo-oct-1-en-3-one, present in all species but highest in Phorbas glaberrima. Several halogenated phenols including 2,4,6-tribromophenol were also abundant in Phorbas glaberrima as were halogenated anisoles in lower relative abundances. The halogenated phenols were analyzed without derivatization. The sample of Halichondria sp. contained the dibromotrichloro monoterpene MHC-1, a recently described environmental contaminant in fish and seals. Retrospective analysis of other marine samples confirmed that 2,4,6-tribromophenol was present in seal blubber from both the Arctic and the Antarctic. The presence of naturally occurring organohalogens such as 2,4,6-tribromophenol and MHC-1 in Antarctic marine invertebrates thus provides a link to their occurrence in marine mammals.