Tibial hemimelia of a different class

A variant of tibial hemimelia, previously undescribed in the literature and not classifiable by either of the established classification systems, is described. The features of this condition include a short, deformed tibia; proximal subluxation of the fibula at the knee; a normal knee joint and an ankle joint that may look abnormal but falls short of true diastasis of the joint. Treatment of two cases by differential lengthening of the tibia and fibula using the Ilizarov device is described. This form of tibial hemimelia should be recognised as a separate variant as preservation of the foot and ankle with expected excellent function should be possible, unlike the more severe forms of this condition.     

Progressive inhibition of neuromuscular structures (PINS) technique

Progressive inhibition of neuromuscular structures (PINS) is a technique that can be included in the osteopathic manipulative treatment repertoire. It relies on knowledge of anatomy and neuromuscular physiologic features as well as on standard forms of osteopathic palpatory diagnosis and treatment. It is a variant of the inhibition technique that has been taught as an osteopathic manipulative technique for many years, and it bears some resemblance to other manual medicine techniques. The emphasis of the approach is the determination of the alteration of the tissues due to dysfunction, delivering treatment based on palpatory evaluation and patient feedback. Two related points are initially chosen, followed by a progression from one to the other. Relationships to similar techniques are also discussed. Theoretical as well as selected practical applications are presented.     

Chemoreflexes: an experimental study

HYPOTHESIS: Transmyocardial laser revascularization (TMLR) will not denervate the heart, because it does not destroy all of the afferents. This study was designed to determine if stimulation of cardiac sympathetic and vagal afferents from an area of the left ventricle treated with TMLR could evoke reflex effects, and thus whether TMLR would denervate the heart. METHODS: The effect of TMLR on reflexes evoked by chemically stimulating cardiac afferents was examined in 9 dogs. Bradykinin and capsaicin were applied topically or injected into the left anterior descending coronary artery before and after TMLR and after bilateral vagotomy and sympathectomy. Aortic (AoP) and left ventricular pressures (LVP) and electrocardiography were monitored. The first derivatives of LVP (dP/dt) were calculated. RESULTS: Topical bradykinin elicited variable hemodynamic responses. Topical capsaicin evoked pressor responses, increasing mean (+/- SEM) AoP (105+/-9 to 115+/-9 mm Hg; P<.001) and positive dP/dt (+dP/dt) (1032+/-81 to 1159+/-10 mm Hg/s; P<.01) before TMLR. Intracoronary capsaicin evoked a depressor response before TMLR. Pressor responses remained intact after TMLR with increases in mean AoP and +dP/dt (115+/-6 to 128+/-5 mm Hg and 1039+/-98 to 1136+/-100 mm Hg/s, respectively; P<.01). Depressor responses also remained intact after TMLR (91+/-10 vs 101+/-11 mm Hg [P<.02], and 865+/-104 vs 931+/-104 mm Hg/s [P<.05], respectively). Hemodynamic responses were diminished after bilateral vagotomy and abolished after bilateral sympathectomy. CONCLUSION: Since activation of cardiac afferent nerves and reflex responses remained intact after TMLR, but changed after vagotomy or sympathectomy, TMLR does not denervate the heart sufficiently to be the cause of improved angina after TMLR.     

Relative bioavailability of ketoprofen 20% in a poloxamer-lecithin organogel.

PURPOSE: The bioavailability of a single, topically applied, 200-mg dose of ketoprofen (delivered in a ketoprofen 20% gel) relative to a single 50-mg oral dose in healthy volunteers was studied. METHODS: This was an open-label crossover study. The subjects were randomized to receive an oral 50-mg ketoprofen capsule or a single topical dose of ketoprofen 20% in a poloxamer-lecithin organogel (PLO). Treatment was followed by a one-week washout period. Blood samples were collected at intervals up to 10 hours after administration, and plasma ketoprofen concentrations were determined by high-performance liquid chromatography with ultraviolet or mass spectrometry detection. Noncompartmental pharmacokinetic values were obtained after each dose, and relative bioavailability was calculated. RESULTS: Eight healthy volunteers enrolled in and completed the study. Topical absorption of ketoprofen was highly variable among the subjects over the 10-hour sampling period. The median oral maximum plasma concentration (Cmax) exceeded the topical Cmax by nearly 200-fold (4.15 versus 0.021 microg/mL) (p = 0.001). The median relative bioavailability of topical ketoprofen was 0.48%, with individual subjects' values ranging from 0.18% to 2.1%. CONCLUSION: The relative bioavailability of ketoprofen was low and highly variable when the drug was administered as a single dose in a PLO-based ketoprofen 20% gel.     

Computational investigation of in situ chondrocyte deformation and actin cytoskeleton remodelling under physiological loading

Previous experimental studies have determined local strain fields for both healthy and degenerate cartilage tissue during mechanical loading. However, the biomechanical response of chondrocytes in situ, in particular the response of the actin cytoskeleton to physiological loading conditions, is poorly understood. In the current study a three-dimensional (3-D) representative volume element (RVE) for cartilage tissue is created, comprising a chondrocyte surrounded by a pericellular matrix and embedded in an extracellular matrix. A 3-D active modelling framework incorporating actin cytoskeleton remodelling and contractility is implemented to predict the biomechanical behaviour of chondrocytes. Physiological and abnormal strain fields, based on the experimental study of Wong and Sah (J. Orthop. Res. 2010; 28: 1554–1561), are applied to the RVE. Simulations demonstrate that the presence of a focal defect significantly affects cellular deformation, increases the stress experienced by the nucleus, and alters the distribution of the actin cytoskeleton. It is demonstrated that during dynamic loading cyclic tension reduction in the cytoplasm causes continuous dissociation of the actin cytoskeleton. In contrast, during static loading significant changes in cytoplasm tension are not predicted and hence the rate of dissociation of the actin cytoskeleton is reduced. It is demonstrated that chondrocyte behaviour is affected by the stiffness of the pericellular matrix, and also by the anisotropy of the extracellular matrix. The findings of the current study are of particular importance in understanding the biomechanics underlying experimental observations such as actin cytoskeleton dissociation during the dynamic loading of chondrocytes.     

Complexities in the process of translating research documents in cross-cultural settings

ABSTRACT

In multilingual societies, where researchers and participants often do not speak the same language, research is a challenge as a mismatch of understanding between researchers, research instruments and participants often occurs. Reporting on the translation process is crucial because of the potential implications for the validity of the data that follow from it. We aimed to report on the complexities of such a translation process and many considerations that came to our attention. Methodologically, we used a detailed case study to demonstrate that the complexity of translation might be underestimated by researchers who may neglect to report on the challenges that they experience to benefit the wider research community. We emphasise that translating documents, particularly between languages that are not cognate, requires time and financial resources that researchers often do not anticipate or plan for. By discussing what happened to texts that were translated, and how we as researchers were challenged by considerations that were primarily linguistic but also straddled cultural and socio-political domains, we hope to encourage a deeper understanding of the translation task. We conclude that consideration of these complexities is necessary if the aim is the development of translated documents which complement the researchers’ goals.