The determinants of performance in master swimmers: an analysis of master world records

Human performances in sports decline with age in all competitions/disciplines. Since the effects of age are often compounded by disuse, the study of master athletes provides the opportunity to investigate the effects of age per se on the metabolic/biomechanical determinants of performance. For all master age groups, swimming styles and distances, we calculated the metabolic power required to cover the distance (d) in the best performance time as: $ E _{\text{maxR}}^{\prime } = C \times d/{\text{BTP}} = C \times v_{\max } , $ where C is the energy cost of swimming in young elite swimmers, v _max?=?d/BTP is the record speed over the distance d, and BTP was obtained form “cross-sectional data” (http://www.fina.org). To establish a record performance, $ E_{\text{maxR}}^{\prime } $ must be equal to the maximal available metabolic power $ (E_{\text{maxA}}^{\prime } ) $ . This was calculated assuming a decrease of 1% per year at 40–70?years, 2% at 70–80?years and 3% at 80–90?years (as indicated in the literature) and compared to the $ E_{\text{maxR}}^{\prime } $ values, whereas up to about 55?years of age $ E_{\text{maxR}}^{\prime } = E_{\text{maxA}}^{\prime } ,$ for older subjects $ E_{\text{maxA}}^{\prime } > E_{\text{maxR}}^{\prime } ,$ the difference increasing linearly by about 0.30% (backstroke), 1.93% (butterfly), 0.92% (front crawl) and 0.37% (breaststroke) per year (average over the 50, 100 and 200?m distances). These data suggest that the energy cost of swimming increases with age. Hence, the decrease in performance in master swimmers is due to both decrease in the metabolic power available $ (E_{\text{maxA}}^{\prime } ) $ and to an increase in C.     

PDGF-BB induces expression of LTBP-1 but not TGF-beta1 in a rat cirrhotic fat storing cell line

TGF-beta, a profibrogenic cytokine is predominantly secreted as a latent molecule complexed with one of the latent TGF-beta binding proteins (LTBP). Due to the proposed functions of LTBP-1 and -3 in regulating TGF-beta-bioavailability and -activity, we investigated the effects of PDGF-BB and TGF-beta1 on their expression levels in Cirrhotic fat storing cells (CFSC). CFSC basally express LTBP-1 and -3 and TGF-beta1. LTBP-1 colocalizes with LAP and the cells secrete some active TGF-beta1. Promoter studies showed no strong induction of the LTBP-1 promoters after stimulation, although mRNA and protein levels were increased by PDGF-BB treatment without affecting TGF-beta1 expression. Vice versa, TGF-beta1 treatment did not alter LTBP-1 expression while an autocrine induction was found. Our data indicate that LTBP-1 but not TGF-beta1 is induced by PDGF-BB and that TGF-beta1 autoinduction does not affect the expression of LTBP-beta1. This divergent regulation may represent an important mechanism for modulation of TGF-beta bioavailability.     

Synchronization in plant cells -- an introduction

Methods in Cell Science -     

Central venous catheterization -- an anatomical review of a clinical skill -- Part 1: subclavian vein via the infraclavicular approach

The safe and successful performance of a central venous catheterization (CVC) requires a specific knowledge of anatomy in addition to a working knowledge. Misunderstanding the anatomy may result in failure or complications. This review aims to aid understanding of the anatomical framework, pitfalls, and complications of CVC of the subclavian (SCV). CVC is common practice amongst surgeons, anesthesiologists, and emergency room physicians during the preparations for major surgical procedures such as open-heart surgery, as well as, for intensive care monitoring and rapid restoration of blood volume. Associated with this technique are certain anatomical pitfalls and complications that can be successfully avoided if one possesses a thorough knowledge of the contraindications, regional anatomy, and rationale of the technique.     

Confluent and reticulated Gougerot-Carteaud papillomatosis: a case report of an excellent response to minocycline

Confluent and reticulated Gougerot-Carteaud papillomatosis is an uncommon dermatological condition that affects adolescents, especially young women with dark skin types. It presents itself as asymptomatic pigmented patches with a papillomatous texture that coalesce to form reticular plaques localized in the neck and intertriginous areas. The cause of this disease is unknown, although an abnormal keratinization has been implicated and sometimes has been associated with Malassezia sp. It has a chronic course with remissions and exacerbations. Several therapies have been used unsuccessfully to eradicate it but nowadays there is no specific treatment. We report a case treated efficiently with minocycline without recurrence at 6 months follow-up.     

Mesenchymal chondrosarcoma of the thyroid -- a rare tumour at an unusual site

We describe the light microscopic, immunohistochemical and ultrastructural features of the first case in the literature of a primary mesenchymal chondrosarcoma (MC) of the thyroid and discuss its differential diagnosis at unusual extraskeletal sites. A nodular lesion of the thyroid with no evidence of extrathyroid disease showed the bimorphic pattern and haemangiopericytoma-like areas typical of MC. In the undifferentiated areas, the cells were CD99 positive/CD117 negative, while the stroma showed focal positivity for alpha-inhibin. In spite of its rarity, it is important to diagnose primary mesenchymal chondrosarcoma in a parenchymatous organ such as the thyroid because its biological behaviour may be different from that of tumours of similar morphology and complete resection is the treatment of choice. The patient is free of disease nearly 66 months after its first presentation. Cytogenetic and immunohistological markers may play important roles in diagnosis of this lesion in future, especially with limited tissue samplings; however, for the present a thorough sampling of the tumour remains the best diagnostic strategy.     

Desmoplasia: not always a bad thing

Abbas O & Mahalingam M
(2011) Histopathology 58 , 643–659
Desmoplasia: not always a bad thing Desmoplasia describes a histological pattern characterized by a hyalinized stroma and a minimal cellular infiltrate. In non‐cutaneous neoplasms, this pattern of stromal response is classically associated with malignancy, whereas in cutaneous pathology, desmoplasia is observed in malignant as well as benign neoplasms. Given this, the obvious question is whether desmoplasia associated with a benign neoplasm is any different from that associated with malignant tumours. Is the stromal response a mere epiphenomenon, or does it actually contribute to the biological behaviour of the neoplasm? What happens at the tumour–host interface? Which molecules are involved in mediating the desmoplastic reaction pattern? This review is an attempt to answer these questions. Examples of benign and malignant cutaneous neoplasms associated with the desmoplastic reaction pattern will be included.     

Understanding what makes a good versus a bad vaccine

The majority of the HIV vaccines under development are aimed at stimulating T cell responses. Therefore, it is critical to delineate the factors regulating the generation of the T cell responses and to develop strategies maximizing vaccine-induced T cell responses. The identification of these factors and the delineation of the kinetics of the generation of vaccine-induced immune responses have been hard to investigate, due to the limited number of precursor naive antigen-specific T cells. To overcome these obstacles, Estcourt and collaborators have developed an elegant strategy that consists of an in vivo mouse model employing transfer of naive CFSE-labeled TCR-transgenic T lymphocytes into syngeneic nontransgenic recipients prior to vaccination. Using this model, the authors demonstrate that the dose, the route of administration and the type of vaccine determine the magnitude, the dissemination and the kinetics of vaccine-induced T cell responses. Furthermore, the mouse model of Estcourt and collaborators may represent the basis for the development of powerful in vivo experimental strategies to evaluate vaccine candidates.     

MFB-1, an F-box-type ubiquitin ligase, regulates TGF-beta signalling

TGF-beta signalling regulates cell growth, differentiation, morphogenesis and apoptosis. MAFbx/Atrogin-1 has been identified as a regulator for skeletal muscle atrophy and encodes an F-box-type E3 ubiquitin ligase. However, little is known about how MAFbx/Atrogin-1 regulates cellular signalling. Here, we identify and genetically characterize MFB-1, a MAFbx/Atrogin-1 homologue from Caenorhabditis elegans. The mfb-1 deletion mutant significantly enhanced the dauer constitutive (Daf-c) phenotype caused by mutations in the DAF-7/TGF-beta-like signalling pathway, but not the DAF-2/insulin receptor-like signalling pathway. Conversely, the Daf-c phenotypes of DAF-7 pathway mutants were partially suppressed by mfb-1 cDNA transgenes. Therefore, MFB-1 acts genetically downstream in the DAF-7 pathway. A mfb-1::GFP fusion was found to be expressed in the nervous system, hypodermis and intestine and overlapped expression of many DAF-7 pathway genes. We propose that MFB-1 is a novel F-box protein that negatively regulates dauer formation in concert with the DAF-7 signalling pathway in C. elegans.     

Fluctuating asymmetry as an animal welfare indicator -- a review of methodology and validity

It has been suggested that fluctuating asymmetry (FA) reflects an animal's ability to cope with the sum of challenges during its growing period and, thus, is a potential welfare indicator. In this review we investigate the evidence of associations between FA and other welfare indicators measured at the level of the individual and of effects of welfare-relevant environmental conditions on FA in populations of captive birds and mammals including humans. As the question of validity cannot be treated independently from the quality of the available data, first a checklist for the proper measurement and analysis of FA is drafted and used to evaluate the methodological quality of the various studies. We recommend this checklist to be used as a standard for future FA studies. We found 17 relevant studies on associations between FA and other welfare indicators, and 36 studies on effects of welfare-relevant factors on FA. Frequent methodological shortcomings or insufficient methodological information allow for only cautious conclusions. The proportion of significant results supporting the link between higher FA and poorer welfare is only moderately high. Independent from statistical significance, almost all studies found the relationship between FA and welfare to be prevailingly in the expected direction. FA is a promising measure of animal welfare, despite a great number of open questions, e.g. relating to the ontogeny of FA or its sensitivity to various stressors. The considerable potential of FA as a welfare indicator makes it worthwhile to pursue more intensely validation studies as well as applied studies. These studies should pay particular attention to an appropriate methodological approach.     

Adventitial lymphatic vessels -- an important role in atherosclerosis

Arterial inflammation is a significant component of atherosclerotic disease-specific immune responses directed against autoantigens or pathogen-derived antigens in the vascular wall could initiate and/or maintain atherosclerotic processes. Atherosclerosis is now regarded as a chronic inflammatory disease. Developing in response to injury in the vessel wall, it is characterized by the infiltration of mononuclear lymphocytes into the intima, local expansion of vascular smooth muscle cells, and accumulation of extracellular matrix. A number of potential mechanisms have been implicated in the development of inflammatory reactions in the vascular system. Adventitia provides cells and molecules with the ability to influence neointimal formation and vascular remodeling implemented in part by vasa vasorum. We hypothesize that lymphatic vessels, existing in adventitia in the atherosclerotic artery, could drain local inflammatory cells and cytokines to the lymphatic nodes and lymphoid tissues where inflammatory cells can be sensitized and activated. Or, blood vessels may deliver sensitized inflammatory cells and cytokines to the inflammatory site of the vascular wall. Therefore, both lymphatic and blood vessels constitute a complete circle of immune response, whereby the inflammatory cells and cytokines are effectively delivered to tissues and their effects magnified. Under certain circumstances, this situation may lead to a vicious circle of inflammation such as in atherosclerosis, resulting in perpetuating intimal hyperplasia and vascular remodeling. Inhibition of lymphangiogenesis may interrupt this self-perpetuating vicious circle of inflammation in atherosclerosis and provide a new approach to the prevention and treatment of the disease.