What you need to know about: organising pneumonia.

Organising pneumonia was first described in the context of respiratory infection, but over time has become established as its own entity. It is an area of diagnostic complexity because of the non-specific presenting symptoms and signs that can often mimic other respiratory pathology. Multidisciplinary review to correlate clinical, radiological and histopathological features can aid timely and effective diagnosis. This article discusses the epidemiology, aetiology, clinical, radiological and histopathological features, investigation and management of organising pneumonia.

Current clinical evidence for the use of mesenchymal stem cells in articular cartilage repair.

INTRODUCTION: Articular cartilage is renowned for its poor intrinsic capacity for repair. Current treatments for osteoarthritis are limited in their ability to reliably restore the native articular cartilage structure and function. Mesenchymal stem cells (MSCs) present an attractive treatment option for articular cartilage repair, with a recent expansion of clinical trials investigating their use in patients. AREAS COVERED: This paper provides a current overview of the clinical evidence on the use of MSCs in articular cartilage repair. EXPERT OPINION: The article demonstrates robust clinical evidence that MSCs have significant potential for the regeneration of hyaline articular cartilage in patients. The majority of clinical trials to date have yielded significantly positive results with minimal adverse effects. However the clinical research is still in its infancy. The optimum MSC source, cell concentrations, implantation technique, scaffold, growth factors and rehabilitation protocol for clinical use are yet to be identified. A larger number of randomised control trials are required to objectively compare the clinical efficacy and long-term safety of the various techniques. As the clinical research continues to evolve and address these challenges, it is likely that MSCs may become integrated into routine clinical practice in the near future.

Review of commonly used age-based weight estimates for paediatric drug dosing in relation to the pharmacokinetic properties of resuscitation drugs.

AIM: To study which weight estimate calculation used in paediatric resuscitation results in optimal drug dosing; Advanced Paediatric and Life Support (APLS) or the UK Resuscitation Council age-based formula. METHOD: Commonly used drugs used in paediatric resuscitation were selected and a literature search conducted for each drug's pharmacokinetic properties, concentrating on the volume of distribution (Vd). Hydrophobic drugs have a higher Vd than hydrophilic drugs as they distribute preferentially to fat mass (FM). The larger the Vd, the higher the initial dose required to achieve therapeutic plasma concentrations. Actual body weight (ABW) estimates are a good indicator of Vd for hydrophobic drugs as they correlate well with FM. Ideal body weight (IBW) estimates may be a better indicator of Vd for hydrophilic drugs, as they correlate better with lean body mass. This highlights potential variation between ABW and IBW, which may result in toxic or sub-therapeutic dosing. RESULTS: The new APLS formulae give higher estimates of expected weight for a wider age range. This may be a more accurate reflection of ABW due to increasing prevalence of obesity in children. The UK Resuscitation Council's formula appears to result in a lower estimate of weight, which may relate more closely to IBW. CONCLUSION: The main drugs used in paediatric resuscitation are hydrophilic, thus the APLS formulae may result in too much being given. Therefore the UK Resuscitation Council's single formula may be preferred. In addition, a single formula may minimize error in the context of a child of unknown weight requiring administration of emergency resuscitation drugs.

Preclinical and clinical data for the use of mesenchymal stem cells in articular cartilage tissue engineering.

INTRODUCTION: With an ageing population, the prevalence of osteoarthritis (OA) has increased. Mesenchymal Stem Cells (MSCs) have been proposed to be an attractive alternative candidate in the tissue engineering of articular cartilage primarily due to its abundant source, reduced cartilage donor site morbidity, and strong capacity for proliferation and potential to differentiate toward a chondrogenic phenotype. AREAS COVERED: A current overview of human, in vivo, and in vitro evidence on the use of MSCs in cartilage tissue engineering. EXPERT OPINION: We demonstrate robust evidence that MSCs have the potential to regenerate articular cartilage. We also identify the complexity of designing a suitable preclinical model and the challenges in considering its clinical application such as type of MSC, scaffold, culture construct and the method by which growth factors are delivered. Of great interest is further characterization of the factors that may prevent MSC-derived chondrocytes to undergo premature hypertrophy and to understand what enables the terminal developmental pathway for permanent hyaline cartilage regeneration. Despite this, there is an abundance of evidence suggesting that MSCs are a desirable cell source and will have significant impact in tissue engineering of cartilage in the future.