Heterothermy and seasonal patterns of metabolic rate in the southern African hedgehog (Atelerix frontalis)

Animals that inhabit unfavourable habitats and experience seasons where the cost of maintenance exceeds the available energy resources have over time developed behavioural and physiological mechanisms to survive. These adaptations include changes in activity, improvement of cold tolerance by using nonshivering thermogenesis (NST), improvement of thermal conductance, reduction of body mass, or acclimation to colder temperatures (reduction of metabolic requirement). In addition some species exhibit heterothermy, in the form of either daily torpor or longer-term hibernation. The southern African hedgehog (Atelerix frontalis) is an excellent candidate to investigate the phenomenon of heterothermy because it is a small insectivore (summer body mass ca. 300 to 400g), burrows, inhabits harsh habitats and is not easy to find during the winter months. In this study I aimed to investigate whether A. frontalis exhibits seasonal differences in metabolic rate and furthermore if this species exhibits heterothermy. The study was carried out in the Northern Cape Province, South Africa. Hedgehogs were hand captured and their metabolic rates were measured using indirect calorimetry. Individuals were implanted with temperature dataloggers for a summer period (November 2009-January 2010) and a winter period (May-August 2009). The summer BMR of adult A. frontalis (0.448 ±0.035 mlO2/g/h, n=4) was significantly lower than their winter BMR (0.811 ±0.073 mlO2/g/h, n=4) and statistical analyses revealed that this was an affect caused by seasonal changes in the ambient environment. Individuals spent up to 84 percent of time during the measurement period torpid (-8°C <Ta<21°C). Body mass appears to be an important factor in determining the pattern of heterothermy (daily torpor versus hibernation) used in this species. To my knowledge the extremely low body temperature (Tb min) of 1.0°C recorded for A. frontalis is the lowest Tb min recorded for a mainland Afrotropical mammal. This species displays classic up-regulation in metabolic rate during winter, resulting in an increase in the energetic requirements of the species. As a result, heterothermy appears to play a significant role in the energy balance of this species during winter, contributing to energy saving. Heterothermy may enable this species to survive in the face of global climate change

Novel biomarker combination improves the diagnosis of serious bacterial infections in Malawian children

<p>Abstract</p> <p>Background</p> <p>High throughput technologies offer insight into disease processes and heightens opportunities for improved diagnostics. Using transcriptomic analyses, we aimed to discover and to evaluate the clinical validity of a combination of reliable and functionally important biomarkers of serious bacterial infection (SBI).</p> <p>Methods</p> <p>We identified three previously reported biomarkers of infection (neutrophil gelatinase-associated lipocalin (NGAL), granulysin and resistin) and measured gene expression using quantitative real-time PCR. Protein products related to the three transcripts were measured by immunoassays.</p> <p>Results</p> <p>Relative gene expression values of NGAL and resistin were significantly increased, and expression of granulysin significantly decreased in cases compared to controls. Plasma concentrations of NGAL and resistin were significantly increased in children with confirmed SBI compared to children with no detectable bacterial infection (NBI), and to controls (287 versus 128 versus 62 ng/ml and 195 versus 90 versus 18 ng/ml, respectively, p < 0.05). Plasma protein concentrations of NGAL and resistin were significantly increased in non-survivors compared to survivors (306 versus 211 and 214 versus 150 ng/ml, p = 0.02). The respective areas under the curve (AUC) for NGAL, resistin and procalcitonin in predicting SBI were 0.79, 0.80 and 0.86, whilst a combination of NGAL, resistin and procalcitonin achieved an AUC of 0.90.</p> <p>Conclusions</p> <p>We have demonstrated a unique combination of diagnostic biomarkers of SBI using transcriptomics, and demonstrated translational concordance with the corresponding protein. The addition of NGAL and resistin protein measurement to procalcitonin significantly improved the diagnosis of SBI.</p

Pain in the Neck after Neck Dissection

Background: Reports of disability after neck dissection have been directed toward shoulder dysfunction and pain. We could find no report addressing the issue of pain localized to the actual operative site. We have conducted a combined prospective and retrospective study of pain in patients undergoing neck dissection. Methods: Eighty-eight disease-free patients were evaluated in 3 groups for neck pain. One group was followed up prospectively for 1 to 8 months after surgery, and 2 retrospective groups were followed up for more than 2 years or for 6 months to 2 years. Pain was assessed by a body map and visual analog scale. Results: None of 31 patients followed up for more than 2 years reported neck pain. Four of 27 patients followed up for 6 to 24 months had pain, with a mean visual analog scale score of 3.7. Seventy percent of the prospective group of 30 patients had pain during the first postoperative week, and only 1 patient had pain persisting for more than 2 months. Shoulder pain and disability after radical neck dissection were encountered in all groups, comparable with the incidence reported in the literature. No postoperative neuromas were found. Conclusions: Chronic pain localized to the operative site is an uncommon occurrence even after radical neck dissection. Chronic pain in the shoulder region may follow radical neck dissection, whereas modified neck dissection is usually a painless procedure. (Otolaryngol Head Neck Surg 2000;123:302–6.