bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma Membrane Subdomain Compartmentalization Contributes to Distinct Mechanisms of Ceramide Action on Insulin Signaling
Authors: Blouin Cédric M. , Prado Cécilia , Takane Karen K. , Lasnier Françoise , Garcia-Ocana Adolfo , Ferré Pascal , Dugail Isabelle , Hajduch Eric 
Published: December 2009

OBJECTIVE
Ceramide is now recognized as a negative regulator of insulin signaling by impairing protein kinase B (PKB)/Akt activation. In different cells, two distinct mechanisms have been proposed to mediate ceramide inhibition of PKB/Akt: one involving atypical protein kinase C zeta (PKCζ) and the other the protein phosphatase-2 (PP2A). We hypothesized that ceramide action through PKCζ or PP2A might depend on plasma membrane (PM) structural organization and especially on caveolin-enriched domain (CEM) abundance.

RESEARCH DESIGN AND METHODS
We have used different PKCζ mutant constructs or the PP2A inhibitor, okadaic acid (OKA), to selectively inhibit PKCζ- and PP2A-dependent pathways in cells expressing different caveolin-1 levels and evaluated the impact of insulin and ceramide on PKB/Akt activity in different PM subdomains.

RESULTS
Although the PKCζ-mediated negative effect of ceramide on insulin-stimulated PKB/Akt was dominant in adipocytes, a ceramide action through PP2A outside CEMs, prevented by OKA, was also unraveled. To test the importance of CEM to direct ceramide action through the PKCζ pathway, we treated 3T3-L1 preadipocytes devoid of CEMs with ceramide and we saw a shift of the lipid-negative action on PKB/Akt to a PP2A-mediated mechanism. In fibroblasts with low CEM abundance, the ceramide-activated PP2A pathway dominated, but could be shifted to a ceramide-activated PKCζ pathway after caveolin-1 overexpression.

CONCLUSIONS
Our results show that ceramide can switch from a PKCζ-dependent mechanism to a PP2A pathway, acting negatively on PKB/Akt, and hence revealing a critical role of CEMs of the PM in this process.
Glucose Induces Pancreatic Islet Cell Apoptosis That Requires the BH3-Only Proteins Bim and Puma and Multi-BH Domain Protein Bax
Authors: McKenzie Mark D. , Jamieson Emma , Jansen Elisa S. , Scott Clare L. , Huang David C.S. , Bouillet Philippe , Allison Janette , Kay Thomas W.H. , Strasser Andreas , Thomas Helen E. 
Published: December 2009

OBJECTIVEHigh concentrations of circulating glucose are believed to contribute to defective insulin secretion and β-cell function in diabetes and at least some of this effect appears to be caused by glucose-induced β-cell apoptosis. In mammalian cells, apoptotic cell death is controlled by the interplay of proapoptotic and antiapoptotic members of the Bcl-2 family. We investigated the apoptotic pathway induced in mouse pancreatic islet cells after exposure to high concentrations of the reducing sugars ribose and glucose as a model of β-cell death due to long-term metabolic stress.RESEARCH DESIGN AND METHODSIslets isolated from mice lacking molecules implicated in cell death pathways were exposed to high concentrations of glucose or ribose. Apoptosis was measured by analysis of DNA fragmentation and release of mitochondrial cytochrome c.RESULTSDeficiency of interleukin-1 receptors or Fas did not diminish apoptosis, making involvement of inflammatory cytokine receptor or death receptor signaling in glucose-induced apoptosis unlikely. In contrast, overexpression of the prosurvival protein Bcl-2 or deficiency of the apoptosis initiating BH3-only proteins Bim or Puma, or the downstream apoptosis effector Bax, markedly reduced glucose- or ribose-induced killing of islets. Loss of other BH3-only proteins Bid or Noxa, or the Bax-related effector Bak, had no impact on glucose-induced apoptosis.CONCLUSIONSThese results implicate the Bcl-2 regulated apoptotic pathway in glucose-induced islet cell killing and indicate points in the pathway at which interventional strategies can be designed.
Duration of Lactation and Incidence of the Metabolic Syndrome in Women of Reproductive Age According to Gestational Diabetes Mellitus Status: A 20-Year Prospective Study in CARDIA (Coronary Artery Risk Development in Young Adults)
Authors: Gunderson Erica P. , Jacobs David R. , Chiang Vicky , Lewis Cora E. , Feng Juanran , Quesenberry Charles P. , Sidney Stephen 
Published: December 2009

OBJECTIVE
The objective of the study was to prospectively assess the association between lactation duration and incidence of the metabolic syndrome among women of reproductive age.

RESEARCH DESIGN AND METHODS
Participants were 1,399 women (39% black, aged 18–30 years) in the Coronary Artery Risk Development in Young Adults (CARDIA) Study, an ongoing multicenter, population-based, prospective observational cohort study conducted in the U.S. Women were nulliparous and free of the metabolic syndrome at baseline (1985–1986) and before subsequent pregnancies, and reexamined 7, 10, 15, and/or 20 years after baseline. Incident metabolic syndrome case participants were identified according to National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. Complementary log-log models estimated relative hazards of incident metabolic syndrome among time-dependent lactation duration categories by gestational diabetes mellitus (GDM) adjusted for age, race, study center, baseline covariates (BMI, metabolic syndrome components, education, smoking, physical activity), and time-dependent parity.

RESULTS
Among 704 parous women (620 non-GDM, 84 GDM), there were 120 incident metabolic syndrome case participants in 9,993 person-years (overall incidence rate 12.0 per 1,000 person-years; 10.8 for non-GDM, 22.1 for GDM). Increased lactation duration was associated with lower crude metabolic syndrome incidence rates from 0–1 month through &gt;9 months (P &lt; 0.001). Fully adjusted relative hazards showed that risk reductions associated with longer lactation were stronger among GDM (relative hazard range 0.14–0.56; P = 0.03) than non-GDM groups (relative hazard range 0.44–0.61; P = 0.03).

CONCLUSIONS
Longer duration of lactation was associated with lower incidence of the metabolic syndrome years after weaning among women with a history of GDM and without GDM, controlling for preconception measurements, BMI, and sociodemographic and lifestyle traits. Lactation may have persistent favorable effects on women's cardiometabolic health.
Insulin-Sensitizing Therapy Attenuates Type 2 Diabetes–Mediated Mammary Tumor Progression
Authors: Fierz Yvonne , Novosyadlyy Ruslan , Vijayakumar Archana , Yakar Shoshana , LeRoith Derek 
Published: December 2009

OBJECTIVE
Type 2 diabetes increases breast cancer risk and mortality, and hyperinsulinemia has been identified as a major factor linking these two diseases. Thus, we hypothesized that pharmacological reduction of elevated insulin levels would attenuate type 2 diabetes–mediated mammary tumor progression.

RESEARCH DESIGN AND METHODS
We studied mammary tumor development in MKR+/+ mice, a nonobese, hyperinsulinemic mouse model of type 2 diabetes. MKR+/+ mice were either crossed with mice expressing the polyoma virus middle T oncogene specifically in the mammary gland or inoculated orthotopically with the mouse mammary tumor cell lines Met-1 and MCNeuA. MKR+/+ or control mice harboring tumors were treated with CL-316243, a specific β3-adrenergic receptor agonist, which sensitizes insulin action but has no direct effect on the mouse mammary epithelium or Met-1 and MCNeuA cells.

RESULTS
CL-316243 treatment significantly reduced the elevated insulin levels in MKR+/+ mice and, as a consequence, attenuated mammary tumor progression in the three tumor models tested. This effect was accompanied by reductions in phosphorylation of insulin and IGF-I receptors in transformed mammary tissue.

CONCLUSIONS
Insulin-sensitizing treatment is sufficient to abrogate type 2 diabetes–mediated mammary tumor progression. Therefore, early administration of insulin-sensitizing therapy may reduce breast cancer risk and mortality in patients with type 2 diabetes.
Effect of Bohm potential on a charged gas
Authors: Mostacci Domiziano , Molinari Vincenzo , Pizzio Francesco 
Published: December 2009

Abstract
Bohm’s interpretation of Quantum Mechanics leads to the derivation of a Quantum Kinetic Equation (QKE): in the present work, propagation of waves in charged quantum gases is investigated starting from this QKE. Dispersion relations are derived for fully and weakly degenerate fermions and bosons (for the latter above critical temperature) and the differences discussed. Use of a kinetic equation permits investigation of “Landau-type” damping: it is found that the presence of damping in fermion gases is dependent upon the degree of degeneracy, whereas it is always present in boson gases. In fully degenerate fermions a phenomenon appears that is akin to the “zero sound” propagation.
B and N-doped double walled carbon nanotube: a theoretical study
Authors: Mendes Lima Welber , Azevedo David , Guerini Silvete 
Published: December 2009

Abstract
The structural and electronic properties of boron and nitrogen atom substitutional doping in (8,0)@(13,0) (semiconductor@semiconductor) and (6,0)@(13,0) (metallic@semiconductor) double walled carbon nanotubes, were obtained by using the first-principle calculations based on the density functional theory. In this framework, the electronic density plays a central role and it was obtained from a self-consistent field form. When boron or nitrogen substitutes a carbon atom the structure remains practically the same with negligible deformation observed around defects in all configurations considered. The electronic band structure results indicate that the boron doped systems behave as a p-type impurity, however, the nitrogen doped systems behave as an n-type impurity. In all the systems investigated here, we found that, in the cases of semiconductor@semiconductor tubes, they were the easiest to incorporate a B atom in the outer-wall and an N atom in the inner-wall of the nanotube.
Nonextensive thermal sources of cosmic rays
Authors: Wilk Grzegorz , Włodarczyk Zbigniew 
Published: December 2009

Abstract
The energy spectrum of cosmic rays exhibits power-like behavior with a very characteristic ‘knee’ structure. We consider a possibility that such a spectrum could be generated by some specific nonstatistical temperature fluctuations in the source of cosmic rays with the ‘knee’ structure reflecting an abrupt change of the pattern of such fluctuations. This would result in a generalized nonextensive statistical model for the production of cosmic rays. The possible physical mechanisms leading to these effects are discussed together with the resulting chemical composition of the cosmic rays, which follows the experimentally observed abundance of nuclei.
Implementation of marginal quantities in management of cogeneration units operating in liberal market environment
Authors: Variny Miroslav , Mierka Otto 
Published: December 2009

AbstractIt is far more important how the cogeneration units are operated than whether they represent the latest technology progress or not. Therefore, for the management of cogeneration units it is a key issue to find optimal operating conditions bringing in the largest income. This may be achieved by combined marginal and overall performance criteria application. To prove this statement, two cogeneration units operating in the Slovak Republic, marked as A and B, were examined. Both of them use the liberal market environment and participate in provisioning ancillary services. Marginal profit values without and with ancillary services provisioning clearly indicate the most advantageous base load value, which is in both cases in the middle of the load regulation range. As shown, together with the total profit function, they are very suitable indicators of the optimal load location and a flexible tool for the market situation evaluation. Heat delivery capability of B to customers reaches its maximum at the middle of the load regulation range, again reinforcing the optimal part load operation. Being equipped with supplementary firing, the marginal steam production of B was found to be higher than 100 % which confirms that the rules for marginal quantities values are not as strict as those for overall and specific quantities.
Procedures of optical control dedicated for laser welding process of biological tissues
Authors: Zając A. , Podniesiński D. , Świderski J. , Kęcik D. , Kęcik M. , Kasprzak J. 
Published: December 2009

AbstractIn this contribution, an optical method of controlling the state of soft biological tissues in real time exposed to laser radiation is discussed. The method is based on the assumption that the change dynamics of the amplitude of the scattered diagnostic radiation (λ = 635 nm) is compatible with the change dynamics of the tissue inner structure exposed to the Nd:YAG laser radiation (λ = 1064 nm). In this method, the measurement of the tissue temperature is omitted. Exemplary results of the laboratory research on this method and an interpretation of the results are presented.
Recent advances on single photon sources based on single colloidal nanocrystals
Authors: Vittorio M. , Pisanello F. , Martiradonna L. , Qualtieri A. , Stomeo T. , Bramati A. , Cingolani R. 
Published: December 2009

AbstractSingle colloidal quantum dots (QDs) are increasingly exploited as triggered sources of single photons. This review reports on recent results on single photon sources (SPS) based on colloidal quantum dots, whose size, shape and optical properties can be finely tuned by wet chemistry approach. First, we address the optical properties of different colloidal nanocrystals, such as dots, rods and dot in rods and their use as single photon sources will be discussed. Then, we describe different techniques for isolation and positioning single QDs, a major issue for fabrication of single photon sources, and various approaches for the embedding single nanocrystals inside microcavities. The insertion of single colloidal QDs in quantum confined optical systems allows one to improve their overall optical properties and performances in terms of efficiency, directionality, life time, and polarization control. Finally, electrical pumping of colloidal nanocrystals light emitting devices and of NC-based single photon sources is reviewed.
Walking Skill Can Be Assessed in Older Adults: Validity of the Figure-of-8 Walk Test
Authors: Hess Rebecca J. , Brach Jennifer S. , Piva Sara R. , VanSwearingen Jessie M. 
Published: December 2009

Background
The Figure-of-8 Walk Test (F8W) involves straight and curved paths and was designed to represent walking skill in everyday life.

Objective
The purposes of this study were to validate the measure in older adults with walking difficulties and to explore correlates of the curved-path walking measure not represented by a straight-path walking measure.

Design
Fifty-one community-dwelling older adults with mobility disability participated in 2 baseline visits as part of an intervention study.

Methods
The F8W time, steps, and smoothness and measures of gait (gait speed, modified Gait Abnormality Rating Scale [GARS-M]), physical function (Late Life Function and Disabilities Index [LLFDI], Survey of Activities and Fear of Falling in the Elderly [SAFFE], Gait Efficacy Scale [GES], Physical Performance Test [PPT], and fall history), and movement control and planning (gait variability, Trail Making Test B [Trails B]) were recorded in each test session. Bivariate correlations for the F8W with each variable were conducted to examine concurrent and construct validity. Adjusted linear regression analyses were performed to explore the variance in mobility explained by F8W independent of gait speed.

Results
Figure-of-8 Walk Test time correlated with gait (gait speed, r=−.570; GARS-M, r=.281), physical function (LLFDI function, r=−.469; SAFFE restriction subscale, r=.370; PPT, r=−.353), confidence in walking (GES, r=−.468), and movement control (step length coefficient of variation, r=.279; step width coefficient of variation, r=−.277; Trails B, r=.351). Figure-of-8 Walk Test steps correlated with step width variability (r=−.339) and was related to fear of falling (t=−2.50). All correlations were significant (P&lt;.05).

Limitations
This pilot study had a small sample size, and further research is needed.

Conclusions
The F8W is a valid measure of walking skill among older adults with mobility disability and may provide information complementary to gait speed.
Early Postoperative Measures Predict 1- and 2-Year Outcomes After Unilateral Total Knee Arthroplasty: Importance of Contralateral Limb Strength
Authors: Zeni Joseph A. , Snyder-Mackler Lynn 
Published: December 2009

Background
Total knee arthroplasty (TKA) has been shown to be an effective surgical intervention for people with end-stage knee osteoarthritis. However, recovery of function is variable, and not all people have successful outcomes.

Objective
The aim of this study was to discern which early postoperative functional measures could predict functional ability at 1 year and 2 years after surgery.

Design and Methods
One hundred fifty-five people who underwent unilateral TKA participated in the prospective longitudinal study. Functional evaluations were performed at the initial outpatient physical therapy appointment and at 1 and 2 years after surgery. Evaluations consisted of measurements of height, weight, quadriceps muscle strength (force-generating capacity), and knee range of motion; the Timed “Up & Go” Test (TUG); the stair-climbing task (SCT); and the Knee Outcome Survey (KOS) questionnaire. The ability to predict 1- and 2-year outcomes on the basis of early postoperative measures was analyzed with a hierarchical regression. Differences in functional scores were evaluated with a repeated-measures analysis of variance.

Results
The TUG, SCT, and KOS scores at 1 and 2 years showed significant improvements over the scores at the initial evaluation (P&lt;.001). A weaker quadriceps muscle in the limb that did not undergo surgery (“nonoperated limb”) was related to poorer 1- and 2-year outcomes even after the influence of the other early postoperative measures was accounted for in the regression. Older participants with higher body masses also had poorer outcomes at 1 and 2 years. Postoperative measures were better predictors of TUG and SCT times than of KOS scores.

Conclusions
Rehabilitation regimens after TKA should include exercises to improve the strength of the nonoperated limb as well as to treat the deficits imposed by the surgery. Emphasis on treating age-related impairments and reducing body mass also might improve long-term outcomes.
Risk factors for asphyxia associated with substandard care during labor
Authors: BERGLUND SOPHIE , GRUNEWALD CHARLOTTA , PETTERSSON HANS , CNATTINGIUS SVEN 
Published: December 2009

AbstractObjective. To identify maternal, pregnancy, delivery and infants characteristics related to neonatal asphyxia and associated with substandard care. Design and setting. A nation‐wide case‐control study in Sweden. Population. Infants born between 1990 and 2005 with a gestational age ≥ 33 weeks and a spontaneous or induced onset of labor. Methods. Cases were 177 previously identified infants suffering from encephalopathy caused by asphyxia where there was suspected substandard care during labor, and where claims for financial compensation were filed. Controls were identified from the population‐based Swedish Medical Birth Register, had an Apgar score of 10 at five minutes, and were alive at 28 days of age. Main outcome measures. Severe asphyxia associated with substandard care during childbirth. Results. Maternal and delivery factors associated with asphyxia included maternal age ≥ 30 years, short maternal stature (≤159 cm), previous cesarean delivery, insulin‐dependent diabetes before pregnancy and gestational diabetes, induced deliveries and delivery at night, with adjusted odds ratios (ORs) ranging from a two‐ to fourfold increase in risk. Compared with non‐dystocic deliveries, the OR for dystocic deliveries was fivefold higher, and was further increased if epidural anesthesia or opioids were used. Small‐ and large‐for‐gestational age infants, post‐term (≥42 weeks) births, twins and breech deliveries had a three‐ to eightfold increase in risk of asphyxia when there was substandard care during labor. Conclusion. Dystocia of labor, especially if epidurals and/or opioids are used, is the strongest risk factor associated with substandard care causing severe asphyxia during labor.
Phosphorylated insulin‐like growth factor binding protein‐1 and cervical measurement in women with threatening preterm birth
Authors: BRIK MAIA , HERNÁNDEZ ANA ISABEL MARTÍNEZ , PEDRAZ CRISTINA CASANOVA , PERALES ALFREDO 
Published: December 2009

AbstractObjective.To assess the efficacy of the cervical phosphorylated insulin‐like growth factor binding protein‐1 (pIGFBP‐1) in combination with cervical length measurement for the prediction of preterm delivery.Design.Observational prospective study.Setting.University Hospital, Spain.Sample.A total of 276 women between 24 and 34 weeks gestational age complaining of uterine contractions and intact membranes.Methods.Transvaginal scan to assess cervical length and cervical swabs for pIGFBP‐1 detection.Main outcome measures.Prevalence of preterm delivery within 48 hours and 7 days, delivery at < 32, < 34 weeks, admission‐to‐delivery interval by cervical length and the presence of pIGFBP‐1.Results.The prevalence of preterm delivery at < 34 weeks was 14.1% (39/276) and 7.6% (21/276) at < 32 weeks. Cervical pIGFBP‐1 was positive in 38.7% (107/276), whereas cervical length < 15 mm was present in 7.2% (20/276) and was > 30 mm for 64.8% (179/276) of the women. The presence of a positive pIGFBP‐1 appeared useful for prediction of delivery before 32 (likelihood ratio (LR) = 2.21, confidence interval (CI): 1.63–3.00) and 34 weeks (LR = 1.76, CI: 1.25–2.41), respectively. Receiver operating characteristic curves were significant for cervical length and pIGFBP‐1 for prediction of delivery at < 34 weeks, < 32 weeks, < 48 hours and < 7 days. Combining pIGFBP‐1 and cervical length had a median interval that was shorter when both were positive as compared to only one positive or both negative, but the CIs overlapped.Conclusions.Both cervical length measurement and pIGFBP‐1 are useful for prediction of spontaneous preterm delivery. A pIGFBP‐1 positive result associated with cervical length does not improve preterm delivery prediction rates.
Neutrophil gelatinase‐associated lipocalin serum evaluation through normal pregnancy and in pregnancies complicated by preeclampsia
Authors: D'ANNA ROSARIO , BAVIERA GIOVANNI , GIORDANO DOMENICO , TODARELLO GIOVANNA , RUSSO SILVIA , RECUPERO STEFANIA , BOLIGNANO DAVIDE , CORRADO FRANCESCO 
Published: December 2009

AbstractNeutrophil gelatinase‐associated lipocalin (NGAL) was evaluated prospectively through normal pregnancy and pregnancies complicated by preeclampsia syndrome. Sixty women enrolled in the study were evaluated for serum NGAL levels at 9–11 weeks gestation, at 24–26 weeks gestation and at delivery. Thirty women were affected by preeclampsia and 30 women with uncomplicated pregnancies formed the control group. NGAL serum concentrations in the preeclampsia group were higher compared to the control group, with significant differences in each trimester. In the first trimester, the median values were: 29.9 ng/mL [interquartile range (IQR) 24.1–50.1] versus 13.6 ng/mL (IQR 9.1–19.9; p < 0.001); in the second trimester: 59.6 ng/mL (IQR 25.3–82.6) versus 16.3 ng/mL (IQR 11.3–23.3; p < 0.001); and in the third trimester: 57.2 ng/mL (IQR 18.7–70.9) versus 15.8 ng/mL (IQR 9.1–22.5; p < 0.001). NGAL serum values were positively correlated with systolic and diastolic blood pressure and with proteinuria.