[Risk of Hip Dislocation - which Patients Need Special Treatment?]. / Risiko Hüftluxation - welche Patienten brauchen besondere Maßnahmen?

INTRODUCTION: Dislocation of a hip arthroplasty is one of the main complications after primary or revision surgery. Definition of specific risk factors concerning patient, indication and surgery makes it possible to determine risk patients for dislocation. AIM: The aim of this study is to identify patient-specific risk factors, such as body mass index (BMI), age and gender, in order to evaluate primary dislocation and to correlate with secondary dislocation. It is investigated whether high BMI, advanced age or female gender are able to promote secondary dislocation. METHOD: In order to identify risk factors for dislocation after primary and revision hip arthroplasty, a retrospective analysis for dislocation was performed of all hip arthroplasties treated in our hospital between 2007 and 2011. 106 patients without an indication for surgical revision were included and treated conservatively. The patient cohort was divided into two groups, depending on the success of the therapy and were analysed for BMI, age and gender. Group I (n = 32) included patients without a re-dislocation event, in contrast to group II (n = 74), which included patients with re-dislocation of the hip arthroplasty. RESULTS: The mean age at the time of primary dislocation was 68 ± 14 years (32 % male and 68 % female). Re-dislocation was presented in 74 cases (70 %). Group II showed a significantly higher BMI (27.11 ± 6.24 kg/m(2)) than group I (24.49 ± 4.86 kg/m(2); p = 0.02). There was no significant effect of age (p = 0.70). The mean age in group I was 71 ± 16 years and in group II of 70 ± 13 years. The incidence of hip dislocation was 2.33-fold higher in women than in men. There was no significant difference between the genders with respect to the risk of re-dislocation. SUMMARY: A higher BMI correlates significantly with a greater risk of re-dislocation of a hip arthroplasty. On the other hand, age and gender do not influence the risk. However, the dislocation of a hip arthroplasty is a multifactorial event, which can be influenced by patient-specific factors as well as specific factors for indication and operation technique.

Automated rodent in situ muscle contraction assay and myofiber organization analysis in sarcopenia animal models.

Age-related sarcopenia results in frailty and decreased mobility, which are associated with increased falls and long-term disability in the elderly. Given the global increase in lifespan, sarcopenia is a growing, unmet medical need. This report aims to systematically characterize muscle aging in preclinical models, which may facilitate the development of sarcopenia therapies. Naïve rats and mice were subjected to noninvasive micro X-ray computed tomography (micro-CT) imaging, terminal in situ muscle function characterizations, and ATPase-based myofiber analysis. We developed a Definiens (Parsippany, NJ)-based algorithm to automate micro-CT image analysis, which facilitates longitudinal in vivo muscle mass analysis. We report development and characterization of translational in situ skeletal muscle performance assay systems in rat and mouse. The systems incorporate a custom-designed animal assay stage, resulting in enhanced force measurement precision, and LabVIEW (National Instruments, Austin, TX)-based algorithms to support automated data acquisition and data analysis. We used ATPase-staining techniques for myofibers to characterize fiber subtypes and distribution. Major parameters contributing to muscle performance were identified using data mining and integration, enabled by Labmatrix (BioFortis, Columbia, MD). These technologies enabled the systemic and accurate monitoring of muscle aging from a large number of animals. The data indicated that longitudinal muscle cross-sectional area measurement effectively monitors change of muscle mass and function during aging. Furthermore, the data showed that muscle performance during aging is also modulated by myofiber remodeling factors, such as changes in myofiber distribution patterns and changes in fiber shape, which affect myofiber interaction. This in vivo muscle assay platform has been applied to support identification and validation of novel targets for the treatment of sarcopenia.

A simple automated solution for removing and applying sealing microplate lids.

With the improved reliability and efficiency of automation, there has been an increased desire to integrate automated sample management with automated screening systems. In order to store samples "on line" for an extended period of time, an automation-compatible means for sealing and unsealing microplates is necessary. Numerous commercial solutions are available for removing loose-fitting microplate lids; however, the task of removing a tight-fitting matted lid such as the RoboLid is more challenging. This paper discusses the design of an automated workstation for the application and removal of such tight-fitting microplate lids.

Control of a remote microscope over the Internet.

Globally connected research sites frequently find the need to share information on a timely basis. The sharing of data obtained from microscopy has historically required that the researcher take micrographs of the desired image and send the film to the other site or, more recently, scan the micrographs into a computer and send the micrographs through e-mail. The authors identified the need to control and view, in as close to real time as possible, images being viewed on a remote microscope. The goal was to develop a system that would be versatile, easy to learn and readily adapted from existing materials and that would allow several users to simultaneously view and control the microscope. The use of commercially available materials along with a simple, custom-designed slide holder allowed researchers at remote sites to view one of 15 slides and move the slide as needed. The penalty for use of the Internet vs. dedicated phone lines such as Integrated Services Digital Network (ISDN) is that only 1 frame/7 s can be viewed at video resolution. The advantages of cost and multiple, simultaneous use over a ubiquitous system outweigh the disadvantage for most users.

Hand-held electronic area planimeter.

The focus of this paper is to describe the development and fabrication of a portable hand-held electronic area planimeter to measure wheal areas during dermatitis assays. The planimeter straddles over the wheal and the scientist traces the wheal's perimeter using an optical beam splitter/cross-hair and a miniature x-y table. Transducers connected to the x-y table and an electronic circuit performs the area integration and displays the data on a digital panel meter. The apparatus permits noncontact measurement of areas up to 1000 mm2 with a resolution of 1 mm2.

A disposable-chamber temperature-regulation system for the study of intracellular calcium levels in single live T cells using fluorescence digital-imaging microscopy.

Utilizing flow cytometry, we previously demonstrated that the potassium channel blocker margatoxin (MgTX) inhibits the [Ca2+]i transient involved in T-cell activation. We wished to extend these studies to single-cell transients using florescence digital-imaging microscopy (DIM). However, the most currently available temperature-regulation chambers reuse part or all of the apparatus and introduce compounds via perfusion. Thus, these apparatuses are not suitable for studies involving compounds that are particularly sticky. We have designed a dual-temperature regulation system that will maintain Nunc, eight-well, coverglass-bottom, disposable chambers, and three disposable addition pipets at 37 degrees C for physiological studies on an inverted digital-imaging microscope. We have demonstrated that calcium transients of human T lymphocytes can be initiated and monitored reproducibly during the addition of three distinct chemical species. The DIM results correlate with flow cytometry measurements in the number of responding cells and the heterogeneity of the response in both control and MgTX-inhibited cultures. Additionally, DIM revealed that the [Ca2+]i transient is more rapid than the flow-cytometric measurement indicated. The correlation between flow cytometry and DIM permits the amalgamation of these results in the interpretation of studies on the regulation of T-cell activation.

Indwelling rumino-reticulum bolus radio beacon.

A miniature battery-powered radio beacon attached to a stainless steel bolus housing an osmotic pump is described. When the bolus, of sufficient size and density to be retained in the reticulum, is administered to ruminants the radio signal can be received, using a standard AM broadcast receiver up to a range of 1.5 m. The unit allows making a simple and inexpensive verification that the drug delivery system is still within the rumino-reticulum during long-term drug delivery studies and making an external estimation of the internal anatomic location of the device.

Neuropharmacology of the parasitic trematode, Schistosoma mansoni.

Neuropharmacological studies of Schistosoma mansoni were conducted in vitro using visual observations of motor activity and measurements of worm length and extracellular electrical activity. The instrumentation and methodology described quantitatively measure extracellular electrical potentials associated with motor activity, and provide a highly sensitive, objective technique for studying effects of antischistosomal compounds and for evaluating schistosomes as a model for neuropharmacological investigation. The visual motor and electrical responses of schistosomes to various pharmacological agents support earlier claims for the presence of an excitatory tryptaminergic system and an inhibitory cholinergic system. The stimulation of motor activity by 5-hydroxytryptamine was blocked by the antagonists metergoline and cyproheptadine in a dose-dependent manner. The hypermotility induced by cholinergic blockade (atropine or mecamylamine) or 5-hydroxytryptamine release (p-chlorophenylethylamine) was abolished by these antagonists. The cholinomimetic agents, acetylcholine, carbachol and arecoline, and the cholinesterase inhibitors neostigmine and metrifonate, caused a flaccid paralysis of schistosomes. Carbachol-induced paralysis was reversed by both the nicotinic cholinergic blocker, mecamylamine, and the muscarinic cholinergic blocker, atropine. This reversal occurred in a dose-dependent manner. It is suggested that the cholinoceptive site in S. mansoni has unique pharmacological properties, distinctly different from those in mammals. Dopamine, apomorphine, epinephrine and norepinephrine had little effect on schistosome motility, but produced marked increases in worm length. The dopaminergic antagonist, haloperidol, completely blocked the dopamine response. A broad range of putative amino acid neurotransmitters failed to alter schistosome motor activity. The simple nervous system of the schistosome appears to have many unique pharmacological features which may make it a useful model for the study of drugs for human use, as well as providing an effective point for chemotherapeutic attack.