bluuebunny/crossref_metadata_2025_split huggingface dataset:
CLINICAL QUESTION: What is the best management strategy for patients with severe insulin resistance?
Authors: Semple Robert K. , Williams Rachel M. , Dunger David B. 
Published: April 2010

SummaryManagement of severe insulin resistance (IR) is a major clinical challenge in many patients with obesity or lipodystrophy, and also in rarer patients with proven or suspected genetic defects in the insulin receptor or downstream signalling. The latter group can present at any time between birth and early adult life, with a variable clinical course broadly correlated with the severity of IR. Primary insulin signalling defects are usually associated with poor weight gain rather than obesity. Initially, extreme hyperinsulinaemia produces ovarian enlargement and hyperandrogenism in women, and often fasting or postprandial hypoglycaemia. However, any hypoglycaemia gradually evolves into insulin‐resistant hyperglycaemia when beta cell function declines. Optimal management of these complex disorders depends on early diagnosis and appropriate targeting of both high and low glucose levels. In newborns, continuous nasogastric feeding may reduce harmful glycaemic fluctuations, and in older patients, acarbose may mitigate postprandial hypoglycaemia. Insulin sensitization, initially with metformin but later with trials of additional agents such as thiazolidinediones, is the mainstay of early therapy, but insulin replacement, eventually with very high doses, is required once diabetes has supervened. Preliminary data suggest that rhIGF‐1 can improve survival in infants with the most severe insulin receptor defects and also improve beta cell function in older patients with milder receptoropathies. The utility of newer therapies such as glucagon‐like peptide‐1 agonists and dipeptidyl peptidase‐IV inhibitors remains untested in this condition. Thus, management of these patients remains largely empirical, and there is a pressing need to collate data centrally to optimize treatment algorithms.
ORIGINAL ARTICLE: Pioglitazone improvement of fasting and postprandial hyperglycaemia in Mexican‐American patients with Type 2 diabetes: a double tracer OGTT study
Authors: Glass Leonard C. , Cusi Kenneth , Berria Rachele , Petz Roberta , Cersosimo Eugenio , Defronzo Ralph A. , Gastaldelli Amalia 
Published: April 2010

SummaryObjectives  By using tracer techniques, we explored the metabolic mechanisms by which pioglitazone treatment for 16 weeks improves oral glucose tolerance in patients with type 2 diabetes when compared to subjects without diabetes.Methods  In all subjects, before and after treatment, we measured rates of tissue glucose clearance (MCR), oral glucose appearance (RaO) and endogenous glucose production (EGP) during a (4‐h) double tracer oral glucose tolerance test (OGTT) (1‐14C‐glucose orally and 3‐3H‐glucose intravenously). Basal hepatic insulin resistance index (HepIR) was calculated as EGPxFPI. β‐cell function was assessed as the incremental ratio of insulin to glucose (ΔI/ΔG) during the OGTT.Results  Pioglitazone decreased fasting plasma glucose concentration (10·5 ± 0·7 to 7·8 ± 0·6 mm, P < 0·0003) and HbA1c (9·7 ± 0·7 to 7·5 ± 0·5%, P < 0·003) despite increased body weight and no change in plasma insulin concentrations. This was determined by a decrease both in fasting EGP (20·0 ± 1·1 to 17·3 ± 0·8 μmol/kgffm min, P < 0·005) and HepIR (from 8194 declined by 49% to 3989, P < 0·002). During the OGTT, total glucose Ra during the 0‐ to 120‐min time period following glucose ingestion decreased significantly because of a reduction in EGP. During the 0‐ to 240‐min time period, pioglitazone caused only a modest increase in MCR (P < 0·07) but markedly increased ΔI/ΔG (P = 0·003). The decrease in 2h‐postprandial hyperglycaemia correlated closely with the increase in ΔI/ΔG (r = −0·76, P = 0·004) and tissue clearance (r = −0·74, P = 0·006) and with the decrease in HepIR (r = 0·62, P = 0·006).Conclusions  In diabetic subjects with poor glycaemic control, pioglitazone improves oral glucose tolerance mainly by enhancing the suppression of EGP and improving β‐cell function.
Effect of cholecalciferol and calcium supplementation on muscle strength and energy metabolism in vitamin D‐deficient Asian Indians: a randomized, controlled trial
Authors: Gupta Rajat , Sharma Uma , Gupta Nandita , Kalaivani M. , Singh U. , Guleria Randeep , Jagannathan N. R. , Goswami Ravinder 
Published: April 2010

SummaryContext  Vitamin D deficiency is prevalent worldwide. Vitamin D supplementation has shown variable effect on skeletal muscle strength in the elderly with hypovitaminosis D. There is a paucity of similar data in young individuals.Objective  To study the effect of cholecalciferol and calcium supplementation on muscle strength and energy metabolism in young individuals.Subjects  Forty healthy volunteers (24M/16F, mean age (SD) 31·5 ± 5·0 year) with hypovitaminosis D were randomized to either oral cholecalciferol (60 000 IU D3/week for 8 weeks followed by 60 000 IU/month for 4 months) with 1 g of elemental calcium daily or dual placebos for 6 months.Measurements  Handgrip and gastro‐soleus dynamometry, pinch‐grip strength, respiratory pressures, 6‐min walk‐test and muscle energy metabolism on 31P magnetic resonance spectroscopy were assessed at baseline and after 6 months.Results  The mean serum 25(OH)D in the supplemented and placebo groups at baseline, two and 6 months were 25·4 ± 9·9, 94·5 ± 53·8 and 56·0 ± 17·0 nm, and 21·1 ± 9·4, 32·8 ± 14·4 and 29·7 ± 15·0 nm, respectively. The supplemented group gained a handgrip strength of 2·4 kg (95% C.I. = 1·2–3·6); gastro‐soleus strength of 3·0 Nm (95% C.I. = 0·1–5·9) and walking distance of 15·9 m (95% C.I. = 6·3–25·5) over the placebo group after adjustment for age, gender and respective baseline parameters. Muscle energy parameters were comparable at 6 months.Conclusions  Six months of cholecalciferol and calcium supplementation results in enhanced skeletal muscle strength and physical performance despite no change in muscle energy parameters. Cholecalciferol supplementation of 60 000 IU per month could not maintain 25(OH)D levels in the sufficient range.
ORIGINAL ARTICLE: Characteristics of plasma NOx levels in severe sepsis: high interindividual variability and correlation with illness severity, but lack of correlation with cortisol levels
Authors: Ho J. T. , Chapman M. J. , O’Connor S. , Lam S. , Edwards J. , Ludbrook G. , Lewis J. G. , Torpy D. J. 
Published: April 2010

SummaryObjectives  Nitric oxide (NO) concentrations are elevated in sepsis and their vasodilatory action may contribute to the development of hyperdynamic circulatory failure. Hydrocortisone infusion has been reported to reduce nitric oxide metabolite (NOx) concentrations and facilitate vasopressor withdrawal in septic shock. Our aim was to determine whether NOx concentrations relate to (i) protocol‐driven vasopressor initiation and withdrawal and (ii) plasma cortisol concentrations, from endogenous and exogenous sources. Demonstration of a relation between NOx, cortisol and vasopressor requirement may provide an impetus towards the study of hydrocortisone‐mediated NOx suppression as a tool in sepsis management.Design  A prospective study of 62 patients with severe sepsis admitted to the intensive care unit.Measurements  Plasma NOx, total and free cortisol, and corticosteroid‐binding globulin (CBG) concentrations were measured and related to protocol‐driven vasopressor use for 7 days following admission.Results  Patients who developed septic shock (n = 35) had higher plasma NOx, total and free cortisol, and lower CBG concentrations than the nonseptic shock group (n = 27). Cortisol, CBG and NOx concentrations correlated with illness severity. Free cortisol, and to a lesser extent total cortisol, but not NOx concentrations, predicted septic shock. NOx concentrations were higher in nonsurvivors, and the concentrations were characteristically stable within individuals but marked interindividual differences were only partly accounted for by illness severity or renal dysfunction. NOx concentrations did not correlate with cortisol, did not relate to vasopressor requirement and did not fall after standard dose hydrocortisone, given for clinical indications.Conclusions  Nitric oxide production increased with sepsis severity but did not correlate with plasma cortisol or vasopressor requirement. NOx levels were not suppressed reproducibly by hydrocortisone. High interindividual variability of NOx levels suggests that absolute NOx levels may not be a suitable target for individualized hydrocortisone therapy.
ORIGINAL ARTICLE: The association between serum thyrotropin (TSH) levels and bone mineral density in healthy euthyroid men
Authors: Kim Beom‐Jun , Lee Seung H. , Bae Sung J. , Kim Hong K. , Choe Jae W. , Kim Ha Y. , Koh Jung‐Min , Kim Ghi S. 
Published: April 2010

SummaryObjective  Although osteoporosis is increasingly shown to occur in a considerable proportion of men, data on risk factors for male osteoporosis are limited. In this study, we investigated the association between serum thyrotropin (TSH) concentration and bone mineral density (BMD) in healthy euthyroid men.Design  A cross‐sectional community (health promotion centre)‐based survey.Subjects and measurements  For 1478 apparently healthy euthyroid men who participated in a routine health screening examination, we measured BMD at the lumbar spine and femoral neck using dual energy X‐ray absorptiometry and serum TSH concentrations using immunoluminometry.Results  Lumbar spine BMD linearly increased with TSH level after adjustment for age, weight and height (P for trend = 0·002), and statistical significance persisted after additional adjustment for smoking and drinking habits (P for trend = 0·010). When serum alkaline phosphatase was added as a confounding variable, the relationship was still significant (P for trend = 0·016). Femoral neck BMD also tended to increase in higher TSH concentration after adjustment for age, weight and height (P for trend = 0·042), but this association disappeared after additional adjustment for smoking and drinking habits. The odds of lower BMD (i.e. osteopaenia and osteoporosis combined) were significantly increased in subjects with low‐normal TSH (i.e. 0·4–1·2 mU/l), when compared to high‐normal TSH (i.e. 3·1–5·0 mU/l), after adjustment for confounding factors (odds ratio = 1·45, 95% CI = 1·02–2·10).Conclusion  These results suggest that a serum TSH concentration at the lower end of the reference range may be associated with low BMD in men.
Detection of alteration at the Millennium uranium deposit in the Athabasca Basin: a comparison of data from two airborne electromagnetic systems with ground resistivity data
Authors: Smith Richard S. , Wood Garnet R. , Powell Brian 
Published: April 2010

ABSTRACTThe Millennium uranium deposit is located within the Athabasca Basin of northern Saskatchewan. The basement rocks, comprised primarily of paleo‐Proterozoic gneisses, are electrically resistive. However, the deposit is associated with highly conductive graphitic metasediments that are intercalated with the gneisses. An unconformity separates the basement rocks from the overlying, horizontally stratified, Proterozoic sandstones of the Athabasca Group (which are also highly resistive). The strike extents of the graphitic metasedimenary packages are extensive and therefore electromagnetic (EM) survey techniques are successful at identifying these zones but do not identify the specific locations where they are enriched in uranium. Through drilling it has been noted that hydrothermal processes associated with mineralization has altered the rocks in the vicinity of the deposits, which should in theory result in a resistivity low. A significant resistivity low has been mapped coincident with the Millennium deposit using ground resistivity survey techniques.However, a comparison of the airborne EM and ground resistivity results reveals that the two data sets have imaged different features. The resistive‐limit (on‐time) windows of the MEGATEM data show conductive features corresponding to lakes located to the west and south of the deposit. The late‐time windows show a feature to the east of the deposit, interpreted as being associated with the east‐dipping graphitic basement conductors (similar to that observed in historical ground EM data collected in this area). The early‐time TEMPEST windows (delay times less than 0.2 ms) show a broad resistivity low located at approximately the same location as where the alteration has been identified through drilling. Modelling the data is not easy but a response that decays prior to 0.3 ms is consistent with 500 Ωm material in the sandstone, a resistivity value close to the lower limit with respect to the hydrothermally altered Athabasca group sediments in this area. The MEGATEM system does not see a conductive zone over the alteration as clearly but the high signal‐to‐noise ratio in the late‐time MEGATEM data means that the conductive material at a greater depth is more coherently imaged.
Near‐field seismic effects in a homogeneous medium and their removal in vertical seismic profile attenuation estimates
Authors: Haase Arnim B. , Stewart Robert R. 
Published: April 2010

ABSTRACTTo better understand (and correct for) the factors affecting the estimation of attenuation (Q), we simulate subsurface wave propagation with the Weyl/Sommerfeld integral. The complete spherical wavefield emanating from a P‐wave point source surrounded by a homogeneous, isotropic and attenuative medium is thus computed. In a resulting synthetic vertical seismic profile, we observe near‐field and far‐field responses and a 90° phase rotation between them. Depth dependence of the magnitude spectra in these two depth regions is distinctly different. The logarithm of the magnitude spectra shows a linear dependence on frequency in the far‐field but not in those depth regions where the near‐field becomes significant. Near‐field effects are one possible explanation for large positive and even negative Q‐factors in the shallow section that may be estimated from real vertical seismic profile data when applying the spectral ratio method. We outline a near‐field compensation technique that can reduce errors in the resultant Q estimates.
Rock fracture compliance derived from time delays of elastic waves
Authors: Möllhoff M. , Bean C.J. , Meredith P.G. 
Published: April 2010

ABSTRACTThe purpose of this study is to compare the reliability of various methods of estimating normal rock fracture compliance from elastic wave measurements. We compare ultrasonic through‐transmission laboratory measurements for a smooth fracture in a Westerly granite specimen with numerical simulations and analytical solutions. The focus is on deriving compliance from time delays. The influence of specimen and source transducer width was constrained using numerical wave simulations. We find that measured ultrasonic phase delays are better suited to estimate the fracture compliance than group delays. Using the frequency domain instead of the time domain increases the accuracy of the fracture compliance estimates. We further show that for cases where precise phase delay measurements are unavailable, employing first break times in conjunction with numerical simulations can be considered as an alternative.
Robust reconstruction of aliased data using autoregressive spectral estimates
Authors: Naghizadeh Mostafa , Sacchi Mauricio D. 
Published: April 2010

ABSTRACTAutoregressive modeling is used to estimate the spectrum of aliased data. A region of spectral support is determined by identifying the location of peaks in the estimated spatial spectrum of the data. This information is used to pose a Fourier reconstruction problem that inverts for a few dominant wavenumbers that are required to model the data. Synthetic and real data examples are used to illustrate the method. In particular, we show that the proposed method can accurately reconstruct aliased data and data with gaps.
A comparative study of dental pulp response to several pulpotomy agents
Authors: Tabarsi B. , Parirokh M. , Eghbal M. J. , Haghdoost A. A. , Torabzadeh H. , Asgary S. 
Published: April 2010

Tabarsi B, Parirokh M, Eghbal MJ, Haghdoost AA, Torabzadeh H, Asgary S. A comparative study of dental pulp response to several pulpotomy agents. International Endodontic Journal 43, 565–571, 2010.AbstractAim  To examine the in vivo response of dental pulps in dogs to three pulp‐capping agents: calcium hydroxide (CH), mineral trioxide aggregate (MTA) and a new endodontic calcium enriched mixture (CEM) cement.Methodology  Thirty‐six second and third premolar teeth in six beagle dogs were randomly assigned to three experimental groups; CH, MTA or CEM cement. Following isolation and exposure, pulp tissues were removed with a fissure bur and haemostasis achieved. The pulps were dressed with appropriate materials, and the access cavity restored with amalgam. Histological analysis was performed 8 weeks after treatment; the samples were assessed by an independent observer for calcified bridge formation, pulp vitality and pulp inflammation. The data were analysed by Kruskal–Wallis, Mann–Whitney and one‐way anova tests.Results  The number of root canals that showed calcified bridge formation, pulp vitality and lack of inflammation was significantly higher for teeth capped with either MTA or CEM cement in comparison with CH (P < 0.05). No significant difference was found between the CEM cement and MTA in terms of calcified bridge formation, pulp vitality and lack of inflammation (P > 0.05).Conclusions  Mineral trioxide aggregate and CEM cement were associated with a similar favourable biological response to pulpotomy treatment and demonstrated a more effective induction of dentinal bridge formation compared to CH.
Antibacterial effects of MDPB against anaerobes associated with endodontic infections
Authors: Izutani N. , Imazato S. , Noiri Y. , Ebisu S. 
Published: April 2010

Izutani N, Imazato S, Noiri Y, Ebisu S. Antibacterial effects of MDPB against anaerobes associated with endodontic infections. International Endodontic Journal.AbstractAim  To investigate the antibacterial effects of 12‐methacryloyloxydodecylpyridinium bromide (MDPB), an antibacterial monomer synthesized by combining quaternary ammonium with a methacryloyl group, against three anaerobes associated with endodontic infections using planktonic and biofilm cells.Methodology  The antibacterial activity of unpolymerized MDPB against Enterococcus faecalis, Fusobacterium nucleatum and Prevotella nigrescens was examined by agar‐disc diffusion tests and determination of the minimum inhibitory/bactericidal concentrations (MIC/MBC). Rapid killing effects of MDPB against three bacteria in planktonic form were examined by a cell number counting method, and those against biofilm cells were assessed by a viability staining method.Results  MDPB demonstrated inhibition against all of the bacteria tested by agar‐disc diffusion tests. The MIC/MBC values of MDPB for the three anaerobes were much smaller than those of other resin monomers, although greater compared with those of cetylpyridinium chloride or chlorhexidine diacetate for E. faecalis and F. nucleatum. Significant reduction in viable planktonic cells was obtained by contact with 250 μg mL−1 of MDPB for 20 s (P < 0.05, Fisher’s PLSD tests), and 40 s contact with 500 μg mL−1 or 20 s contact with 1000 μg mL−1 of MDPB resulted in more than 90% killing. Biofilm cells of all species were completely killed by application of 1000 μg mL−1 of MDPB for 60 s.Conclusion  MDPB was found to have strong antibacterial effects against E. faecalis, F. nucleatum and P. nigrescens, and such effects were rapidly exhibited even against biofilm cells, suggesting the usefulness of application of MDPB to resin‐based materials for root canal filling.
Bird community response to fruit energy
Authors: Peters Valerie E. , Mordecai Rua , Ronald Carroll C. , Cooper Robert J. , Greenberg Russell 
Published: April 2010

Summary 1. The abundance and predictability of food resources have been posited as explanations for the increase of animal species richness in tropical habitats. However, the heterogeneity of natural ecosystems makes it difficult to quantify a response of animal species richness to these qualities of food resources. 2. Fruit‐frugivore studies are especially conducive for testing such ecological theories because fruit is conspicuous and easily counted. Fruit‐frugivore research in some locations has demonstrated a relationship between animal abundance and fruit resource abundance, both spatially and temporally. These studies, which typically use fruit counts as the variable of fruit abundance, have never documented a response of species richness at the community level. Furthermore, these studies have not taken into account factors influencing the detection of an individual within surveys. 3. Using a combination of nonstandard approaches to fruit‐frugivore research, we show a response of bird species richness to fruit resources. First, we use uniform and structurally similar, one‐ha shade‐grown coffee plots as replicated experimental units to reduce the influence of confounding variables. Secondly, we use multi‐season occupancy modelling of a resident omnivorous bird assemblage in order to account for detection probability in our analysis of site occupancy, local immigration and local emigration. Thirdly, we expand our variable of fruit abundance, Fruit Energy Availability (FEA), to include not only fruit counts but also fruit size and fruit quality. 4. We found that a site’s average monthly FEA was highly correlated (0·90) with a site’s average bird species richness. In our multi‐season occupancy model 92% of the weight of evidence supported a single model that included effects of FEA on initial occupancy, immigration, emigration and detection. 5. These results demonstrate that fruit calories can broadly influence the richness of a neotropical bird community, and that fluctuations of FEA explains much of the site occupancy patterns of component species. This study shows that in depauperate, managed landscapes fruit resource abundance supports more species and fruit constancy allows for higher levels of avian persistence, an important practical concept for conservation planning.
‘Take‐away’ foraging spatially uncouples predator and prey‐attack distributions
Authors: Smallegange Isabel M. , Van Der Meer Jaap , Sabelis Maurice W. 
Published: April 2010

Summary 1. Ideal‐free distribution theory assumes that in a patchy environment foragers maximize fitness and hence their feeding rate by balancing gains from more food against losses from more competition. Ultimately, individuals cannot increase their feeding rate by moving to another patch and they distribute themselves over patches in proportion to prey density per patch. 2. In our experiments with shore crabs Carcinus maenas foraging on two adjacent patches with mussels Mytilus edulis, the implicit assumption of ideal‐free distribution theory that catch should match time spent in a prey patch is not met, however. Despite aggregating their attack where it is most profitable shore crabs distributed themselves homogeneously across mussel patches: they ‘take away’ the prey caught and consume it elsewhere to reduce interference. 3. Thus, predator distributions can be quite different from prey‐attack distributions. This is important because the latter is shown to be decisive for persistence of predator and prey populations in ecological models.