Assessment of the centre of pressure pattern and moments about S2 in scoliotic subjects during normal walking

Background Context: Research employing gait measurements indicate asymmetries in ground reaction forces and suggest relationships between these asymmetries, neurological dysfunction and spinal deformity. Although, studies have documented the use of centre of pressure (CoP) and net joint moments in gait assessment and have assessed centre of mass (CoM)-CoP distance relationships in clinical conditions, there is a paucity of information relating to the moments about CoM. It is commonly considered that CoM is situated around S2 vertebra in normal upright posture and hence this study uses S2 vertebral prominence as reference point relative to CoM. Purpose: To assess and establish asymmetry in the CoP pattern and moments about S2 vertebral prominence during level walking and its relationship to spinal deformity in adolescents with scoliosis. Patient sample: Nine Adolescent Idiopathic Scoliosis subjects (8 females and 1 male with varying curve magnitudes and laterality) scheduled for surgery within 2-3 days after data collection, took part in this study. Outcome measures: Kinetic and Kinematic Gait assessment was performed with an aim to estimate the CoP displacement and the moments generated by the ground reaction force about the S2 vertebral prominence during left and right stance during normal walking. Methods: The study employed a strain gauge force platform to estimate the medio-lateral and anterior-posterior displacement of COP and a six camera motion analysis system to track the reflective markers to assess the kinematics. The data were recorded simultaneously. Results: Results indicate wide variations in the medio lateral direction CoP, which could be related to the laterality of both the main and compensation curves. This variation is not evident in the anterior-posterior direction. Similar results were recorded for moments about S2 vertebral prominence. Subjects with higher left compensation curve had greater displacement to the left. Conclusion: Although further longitudinal studies are needed, results indicate that the variables identified in this study are applicable to initial screening and surgical evaluation of scoliosis. © 2008 Chockalingam et al; licensee BioMed Central Ltd

Explorations, Vol. 5, No. 1

Articles include: Cover: What Have We Done with Tomorrow? by Leslie C. Hyde, UMCES Extension Agent for Knox-Lincoln Counties. Editorial Reflections, Carole J. Bombard UMCES: an overview Conversation with the Director: Assistant Vice-President Judith Bailey Reaching Out for Teen Awareness, by Theresa M. Ferrari Profile of a Harbormaster, by Carole J. Bombard Minding Maine’s Business, by Mary S. Bowie Family Resource Management: Learning to ease the burden, by Olive Dubord and Doris Cushman Breaking Free and Taking Control: Helen Sawyer’s Story, by Doris Manley Partnership in Conservation: The Josephine Newman Sanctuary, by Nancy Coverstone The Mount Desert Island Health Promotion Project, by Ron Beard Dynamics of Weed Control in Agriculture, by Leigh Morrow From Generation to Generation: An Extension Homemaker Family, by Nadine B. Reimer ICLAD: The Institute for Community Leadership and Development, by Jim Killacky and Deb Burwell Exploding the Cinderella Syndrome: Strengthening Stepfamilies, by Wendy Pollock Integrated Pest Management: Bringing it all together, by Glen Koehler and Jim Dill Addressing the Issues, by Patricia M. Pierson Anti-Bruise: What’s It All About? Maine Potato Harvest Anti-Bruise Program, by Neal D. Hallee H.O.P.E. Addresses Teenage Pregnancy, by Jane M. Kelly Saving Money and the Environment, by Vaughn H. Holyoke Reservoir Tillage in Nonirrigated Potato Production, by Leigh Morrow Managing Pesticide Drift, by James D. Dwyer, Leigh S. Morrow and James F. Dill The St. George River Project — what have we done with tomorrow? Putting Research to Work, by Stephen Belyea The Best Maine Blue: Fresh Pack Blueberries, by Tom DeGomez Maine’s Green Sea Urchin, by Benjamin A. Baxter Interfaces and Cooperation: Wildlife and Fisheries Sampler, by Catherine A. Elliott Extension Responds to the Salmonella Scare, by Nellie Hedstrom and Mahmoud El-Begearm

Quantitative Analysis of Mechanisms That Govern Red Blood Cell Age Structure and Dynamics during Anaemia

Mathematical modelling has proven an important tool in elucidating and quantifying mechanisms that govern the age structure and population dynamics of red blood cells (RBCs). Here we synthesise ideas from previous experimental data and the mathematical modelling literature with new data in order to test hypotheses and generate new predictions about these mechanisms. The result is a set of competing hypotheses about three intrinsic mechanisms: the feedback from circulating RBC concentration to production rate of immature RBCs (reticulocytes) in bone marrow, the release of reticulocytes from bone marrow into the circulation, and their subsequent ageing and clearance. In addition we examine two mechanisms specific to our experimental system: the effect of phenylhydrazine (PHZ) and blood sampling on RBC dynamics. We performed a set of experiments to quantify the dynamics of reticulocyte proportion, RBC concentration, and erythropoietin concentration in PHZ-induced anaemic mice. By quantifying experimental error we are able to fit and assess each hypothesis against our data and recover parameter estimates using Markov chain Monte Carlo based Bayesian inference. We find that, under normal conditions, about 3% of reticulocytes are released early from bone marrow and upon maturation all cells are released immediately. In the circulation, RBCs undergo random clearance but have a maximum lifespan of about 50 days. Under anaemic conditions reticulocyte production rate is linearly correlated with the difference between normal and anaemic RBC concentrations, and their release rate is exponentially correlated with the same. PHZ appears to age rather than kill RBCs, and younger RBCs are affected more than older RBCs. Blood sampling caused short aperiodic spikes in the proportion of reticulocytes which appear to have a different developmental pathway than normal reticulocytes. We also provide evidence of large diurnal oscillations in serum erythropoietin levels during anaemia

Breast cancer in young women and its impact on reproductive function

BACKGROUND: Breast cancer is the most common cancer in women in developed countries, and 12% of breast cancer occurs in women 20-34 years. Survival from breast cancer has significantly improved, and the potential late effects of treatment and the impact on quality of life have become increasingly important. Young women constitute a minority of breast cancer patients, but commonly have distinct concerns and issues compared with older women, including queries regarding fertility, contraception and pregnancy. Further, they are more likely than older women to have questions regarding potential side effects of therapy and risk of relapse or a new primary. In addition, many will have symptoms associated with treatment and they present a management challenge. Reproductive medicine specialists and gynaecologists commonly see these women either shortly after initial diagnosis or following adjuvant therapy and should be aware of current management of breast cancer, the options for women at increased genetic risk, the prognosis of patients with early stage breast cancer and how adjuvant systemic treatments may impact reproductive function. METHODS: No systematic literature search was done. The review focuses on the current management of breast cancer in young women and the impact of treatment on reproductive function and subsequent management. With reference to key studies and meta-analyses, we highlight controversies and current unanswered questions regarding patient management. RESULTS: Chemotherapy for breast cancer is likely to negatively impact on reproductive function. A number of interventions are available which may increase the likelihood of future successful pregnancy, but the relative safety of these interventions is not well established. For those who do conceive following breast cancer, there is no good evidence that pregnancy is detrimental to survival. We review current treatment; effects on reproductive function; preservation of fertility; contraception; pregnancy; breastfeeding and management of menopausal symptoms following breast cancer. CONCLUSION: This paper provides an update on the management of breast cancer in young women and is targeted at reproductive medicine specialists and gynaecologists

Parallel Computational Subunits in Dentate Granule Cells Generate Multiple Place Fields

A fundamental question in understanding neuronal computations is how dendritic events influence the output of the neuron. Different forms of integration of neighbouring and distributed synaptic inputs, isolated dendritic spikes and local regulation of synaptic efficacy suggest that individual dendritic branches may function as independent computational subunits. In the present paper, we study how these local computations influence the output of the neuron. Using a simple cascade model, we demonstrate that triggering somatic firing by a relatively small dendritic branch requires the amplification of local events by dendritic spiking and synaptic plasticity. The moderately branching dendritic tree of granule cells seems optimal for this computation since larger dendritic trees favor local plasticity by isolating dendritic compartments, while reliable detection of individual dendritic spikes in the soma requires a low branch number. Finally, we demonstrate that these parallel dendritic computations could contribute to the generation of multiple independent place fields of hippocampal granule cells