bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of gender on lipid-induced insulin resistance in obese subjects
Authors: Vistisen Bodil , Hellgren Lars I , Vadset Torill , Scheede-Bergdahl Celena , Helge Jørn Wulff , Dela Flemming , Stallknecht Bente 
Published: January 2008

ObjectiveIn obese subjects, chronically elevated plasma concentrations of non-esterified fatty acids (NEFAs) exert a marked risk to contract insulin resistance and subsequently type 2 diabetes. When NEFA is acutely increased due to i.v. infusion of lipid, glucose disposal during a hyperinsulinemic–euglycemic clamp is reduced. This effect has been explained by a NEFA-induced decrease in skeletal muscle insulin sensitivity caused by accumulation of the lipid intermediates such as ceramide and diacylglycerol in the myocytes. However, neither the lipid-induced reduction of glucose disposal nor the intramyocellular lipid deposition has been compared directly in obese females and males.DesignWe studied eight obese females and eight obese males (body mass index (BMI): 32.6±1.4 and 32.8±0.8 respectively, non significant (NS)) matched for cardiorespiratory fitness relative to lean body mass (43.7±1.6 and 47.6±1.3 ml/kg min respectively, NS).MethodsEach subject underwent two hyperinsulinemic–euglycemic clamps with infusion of lipid or saline respectively. Furthermore, the subjects exercised during the last half an hour of each clamp.ResultsThe lipid-induced reduction in glucose disposal during the clamp was similar in females and males (46±10 and 60±4% respectively, NS). However, whole-body insulin sensitivity as well as non-oxidative glucose disposal was higher in obese females compared with obese males both during lipid and saline infusion (P<0.001 andP=0.01 respectively). Muscle ceramide, triacylglycerol (TAG), diacylglycerol (DAG), and glycogen content were similar between sexes and remained unchanged during the clamp and when exercise was superimposed.ConclusionsThe lipid-induced inhibition of glucose disposal is similar in obese females and males. However, obese females are more insulin sensitive compared with obese males (both during saline and lipid infusion), which is not due to differences in the concentration of the muscle lipid intermediates such as ceramide and DAG.
Impact of metformin versus the prandial insulin secretagogue, repaglinide, on fasting and postprandial glucose and lipid responses in non-obese patients with type 2 diabetes
Authors: Lund Søren S , Tarnow Lise , Frandsen Merete , Smidt Ulla M , Pedersen Oluf , Parving Hans-Henrik , Vaag Allan A 
Published: January 2008

ObjectiveNon-obese patients with type 2 diabetes (T2DM) are characterized by predominant defective insulin secretion. However, in non-obese T2DM patients, metformin, targeting insulin resistance, is non-inferior to the prandial insulin secretagogue, repaglinide, controlling overall glycaemia (HbA1c). Whether the same apply for postprandial glucose and lipid metabolism is unknown. Here, we compared the effect of metformin versus repaglinide on postprandial metabolism in non-obese T2DM patients.DesignSingle-centre, double-masked, double-dummy, crossover study during 2×4 months involving 96 non-obese (body mass index≤27 kg/m2) insulin-naïve T2DM patients. At enrolment, patients stopped prior oral hypoglycaemic agents therapies and after a 1-month run-in period on diet-only treatment, patients were randomized to repaglinide (2 mg) thrice daily followed by metformin (1 g) twice daily or vice versa each during 4 months with 1-month washout between interventions.MethodsPostprandial metabolism was evaluated by a standard test meal (3515 kJ; 54% fat, 13% protein and 33% carbohydrate) with blood sampling 0–6 h postprandially.ResultsFasting levels and total area under the curve (AUC) for plasma glucose, triglycerides and free fatty acids (FFA) changed equally between treatments. In contrast, fasting levels and AUC of total cholesterol, low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (non-HDL) cholesterol and serum insulin were lower during metformin than repaglinide (mean (95% confidence intervals), LDL cholesterol difference metformin versus repaglinide: AUC: −0.17 mmol/l (−0.26; −0.08)). AUC differences remained significant after adjusting for fasting levels.ConclusionsIn non-obese T2DM patients, metformin reduced postprandial levels of glycaemia, triglycerides and FFA similarly compared to the prandial insulin secretagogue, repaglinide. Furthermore, metformin reduced fasting and postprandial cholesterolaemia and insulinaemia compared with repaglinide. These data support prescription of metformin as the preferred drug in non-obese patients with T2DM targeting fasting and postprandial glucose and lipid metabolism.
Ketoconazole revisited: a preoperative or postoperative treatment in Cushing's disease
Authors: Castinetti F , Morange I , Jaquet P , Conte-Devolx B , Brue T 
Published: January 2008

ContextAlthough transsphenoidal surgery remains the first-line treatment in Cushing's disease (CD), recurrence is observed in about 20% of cases. Adjunctive treatments each have specific drawbacks. Despite its inhibitory effects on steroidogenesis, the antifungal drug ketoconazole was only evaluated in series with few patients and/or short-term follow-up.ObjectiveAnalysis of long-term hormonal effects and tolerance of ketoconazole in CD.DesignA total of 38 patients were retrospectively studied with a mean follow-up of 23 months (6–72).SettingAll patients were treated at the same Department of Endocrinology in Marseille, France.PatientsThe 38 patients with CD, of whom 17 had previous transsphenoidal surgery.InterventionKetoconazole was begun at 200–400 mg/day and titrated up to 1200 mg/day until biochemical remission.Main outcome measuresPatients were considered controlled if 24-h urinary free cortisol was normalized.ResultsFive patients stopped ketoconazole during the first week because of clinical or biological intolerance. On an intention to treat basis, 45% of the patients were controlled as were 51% of those treated long term. Initial hormonal levels were not statistically different between patients controlled or uncontrolled. Ketoconazole was similarly efficacious as a primary or postoperative treatment. Among 15 patients without visible adenoma at initial evaluation, subsequent follow-up allowed identification of the lesion in five cases. No adrenal insufficiency was observed. Adverse effects were rare in patients treated long term.ConclusionsKetoconazole is a safe and efficacious treatment in CD, particularly in patients for whom surgery is contraindicated, or delayed because of the absence of image of adenoma on magnetic resonance imaging.
Fibroblast growth factor-23 is associated with parathyroid hormone and renal function in a population-based cohort of elderly men
Authors: Marsell Richard , Grundberg Elin , Krajisnik Tijana , Mallmin Hans , Karlsson Magnus , Mellström Dan , Orwoll Eric , Ohlsson Claes , Jonsson Kenneth B , Ljunggren Östen , Larsson Tobias E 
Published: January 2008

ObjectiveFibroblast growth factor-23 (FGF23) is a circulating factor involved in phosphate (Pi) and vitamin D metabolism. Serum FGF23 is increased at later stages of chronic kidney disease due to chronic hyperphosphatemia and decreased renal clearance. Recent studies also indicate that FGF23 may directly regulate the expression of parathyroid hormone (PTH) in vitro. Therefore, the objective of the current study was to determine the relationship between FGF23, PTH, and other biochemistries in vivo in subjects with no history of renal disease.DesignSerum biochemistries were measured in a subsample of the population-based Swedish part of the MrOS study. In total, 1000 Caucasian men aged 70–80 years were randomly selected from the population.MethodsIntact FGF23, Pi, calcium, albumin, estimated glomerular filtration rate (eGFR, calculated from cystatin C), PTH, and 25(OH)D3 were measured. Association studies were performed using linear univariate and multivariate regression analyses.ResultsThe median FGF23 level was 36.6 pg/ml, ranging from 0.63 to 957 pg/ml. There was a significant correlation between log FGF23 and eGFR (r=−0.21; P<0.00001) and log PTH (r=0.13; P<0.001). These variables remained as independent predictors of FGF23 in multivariate analysis. In addition, log PTH (β=0.082; P<0.05) and eGFR (β=−0.090; P<0.05) were associated with log FGF23 in subjects with eGFR>60 ml/min. Only eGFR (β=−0.35; P<0.0001) remained as a predictor of log FGF23 in subjects with eGFR<60 ml/min.ConclusionsSerum FGF23 and PTH are associated in vivo, supporting recent findings that FGF23 directly regulates PTH expression in vitro. Additionally, eGFR is associated with FGF23 in subjects with normal or mildly impaired renal function, indicating that GFR may modulate FGF23 levels independent of serum Pi.
FALDH Reverses the Deleterious Action of Oxidative Stress Induced by Lipid Peroxidation Product 4-Hydroxynonenal on Insulin Signaling in 3T3-L1 Adipocytes
Authors: Demozay Damien , Mas Jean-Christophe , Rocchi Stephane , Van Obberghen Emmanuel 
Published: January 2008

OBJECTIVE— Oxidative stress is associated with insulin resistance and is thought to contribute to progression toward type 2 diabetes. Oxidation induces cellular damages through increased amounts of reactive aldehydes from lipid peroxidation. The aim of our study was to investigate 1) the effect of the major lipid peroxidation end product, 4-hydroxynonenal (HNE), on insulin signaling in 3T3-L1 adipocytes, and 2) whether fatty aldehyde dehydrogenase (FALDH), which detoxifies HNE, protects cells and improves insulin action under oxidative stress conditions.
RESEARCH DESIGN AND METHODS— 3T3-L1 adipocytes were exposed to HNE and/or infected with control adenovirus or adenovirus expressing FALDH.
RESULTS— Treatment of 3T3-L1 adipocytes with HNE at nontoxic concentrations leads to a pronounced decrease in insulin receptor substrate (IRS)-1/-2 proteins and in insulin-induced IRS and insulin receptor β (IRβ) tyrosine phosphorylation. Remarkably, we detect increased binding of HNE to IRS-1/-2–generating HNE-IRS adducts, which likely impair IRS function and favor their degradation. Phosphatidylinositol 3-kinase and protein kinase B activities are also downregulated upon HNE treatment, resulting in blunted metabolic responses. Moreover, FALDH, by reducing adduct formation, partially restores HNE-generated decrease in insulin-induced IRS-1 tyrosine phosphorylation and metabolic responses. Moreover, rosiglitazone could have an antioxidant effect because it blocks the noxious HNE action on IRS-1 by increasing FALDH gene expression. Collectively, our data show that FALDH improves insulin action in HNE-treated 3T3-L1 adipocytes.
CONCLUSION— Oxidative stress induced by reactive aldehydes, such as HNE, is implicated in the development of insulin resistance in 3T3-L1 adipocytes, which is alleviated by FALDH. Hence, detoxifying enzymes could play a crucial role in blocking progression of insulin resistance to diabetes.
Quantitative Linkage Analysis for Pancreatic B-cell Function and Insulin Resistance in a Large Twin Cohort
Authors: Falchi Mario , Wilson Scott G. , Paximadas Dimitrios , Swaminathan Ramasamyiyer , Spector Tim D. 
Published: January 2008

OBJECTIVE—Insulin resistance and disturbed glucose homeostasis are key characteristics of metabolic syndrome, diabetes, and cardiovascular disease. The recent nonlinear computer version of homeostasis model assessment (HOMA)2 provides an appropriate and convenient assessment of glucose metabolism, enabling gene-mapping studies in large population samples.
RESEARCH DESIGN AND METHODS—Fasting insulin and glucose concentration were measured in 758 dizygous and 305 monozygous nondiabetic female pairs from the St. Thomas’ U.K. adult twin registry (TwinsUK). Insulin resistance (IR) and pancreatic β-cell function (BCF) were estimated from this data using the HOMA2 model.
RESULTS—Genome-wide variance component linkage analysis using 2,231 genetic markers identified a highly significant quantitative trait locus for BCF on chromosome 10p15 (logarithm of odds [LOD] 6.2, P = 0.0001), a region recently shown to contain a functional variant for type 1 diabetes. Both BCF and IR suggested a pleiotropic effect on 17q25 (univariate LOD 3.2, P = 0.0012, and 2.38, P = 0.0087; bivariate LOD 2.66), and one additional region showed linkage for IR on chromosome 22q11 (LOD 3.2, P = 0.0016), providing replication and refining previous findings for diabetes and associated traits.
CONCLUSIONS—To our best knowledge, this is the first genome-wide linkage screen for HOMA2 indexes in a large, healthy female sample. These results suggest that loci involved in control of normal glucose homeostasis among nondiabetic individuals might overlap with those involved in the development of diabetes. Linkage replications in independent studies and across populations provide information on important regions of common but potentially heterogeneous variability that can now be used for targeted positional candidate studies.
Physiological and Molecular Determinants of Insulin Action in the Baboon
Authors: Chavez Alberto O. , Lopez-Alvarenga Juan C. , Tejero M. Elizabeth , Triplitt Curtis , Bastarrachea Raul A. , Sriwijitkamol Apiradee , Tantiwong Puntip , Voruganti V. Saroja , Musi Nicolas , Comuzzie Anthony G. , DeFronzo Ralph A. , Folli Franco 
Published: January 2008

OBJECTIVE—To quantitate insulin sensitivity in lean and obese nondiabetic baboons and examine the underlying cellular/molecular mechanisms responsible for impaired insulin action to characterize a baboon model of insulin resistance.
RESEARCH DESIGN AND METHODS—Twenty baboons received a hyperinsulinemic-euglycemic clamp with skeletal muscle and visceral adipose tissue biopsies at baseline and at 30 and 120 min after insulin. Genes and protein expression of key molecules involved in the insulin signaling cascade (insulin receptor, insulin receptor substrate-1, p85, phosphatidylinositol 3-kinase, Akt, and AS160) were sequenced, and insulin-mediated changes were analyzed.
RESULTS—Overall, baboons show a wide range of insulin sensitivity (6.2 ± 4.8 mg · kg−1 · min−1), and there is a strong inverse correlation between indexes of adiposity and insulin sensitivity (r = −0.946, P &lt; 0.001 for % body fat; r = −0.72, P &lt; 0.001 for waist circumference). The genes and protein sequences analyzed were found to have ∼98% identity to those of man. Insulin-mediated changes in key signaling molecules were impaired both in muscle and adipose tissue in obese insulin-resistant compared with lean insulin-sensitive baboons.
CONCLUSIONS—The obese baboon is a pertinent nonhuman primate model to examine the underlying cellular/molecular mechanisms responsible for insulin resistance and eventual development of type 2 diabetes.
In vitro efficacy of an ophthalmic drug combination against corneal pathogens of horses
Authors: Scotty Nicole C. , Brooks Dennis E. , Schuman Rose Crystal D. 
Published: January 2008

Abstract
Objective—To evaluate the in vitro efficacy of an ophthalmic drug combination against common corneal pathogens of horses.
Sample Population—Representative isolates of 3 bacterial and 2 fungal corneal pathogens of horses.
Procedures—Pathogens were subjected to minimum inhibitory concentration (MIC) testing of a drug combination that consisted of equal volumes of natamycin 3.33%, tobramycin 0.3%, cefazolin 5.5%, and equine serum. Proteinase inhibitory activity of the drug combination was assessed by use of a fluorescence microplate assay with gelatin and collagen I as substrates. The MICs of the drug combination were compared with those for each of the component medications and antiproteinase activity of the drug combination was compared with that of serum by use of paired t tests and a 2-way ANOVA, respectively.
Results—The drug combination was at least as effective as each medication separately for inhibiting microbial growth of all pathogens tested and was significantly more effective against B-hemolytic Streptococcus spp, Aspergillus spp, and Fusarium spp than the relevant medications separately. Serum and the drug combination both had significant antigelatinase activity, and serum had significant anticollagenase activity. Antiproteinase activity of serum was a concentration-dependent event, which enabled serum to achieve significantly greater activity than the drug combination after 3.5 and 4 hours of intubation for the gelatin and collagen I assays, respectively.
Conclusions and Clinical Relevance—Drug combinations have the attractive potential of minimizing the time, stress, and fatigue associated with topical treatment regimens consisting of multiple drugs used separately for horses with keratitis.
Evaluation of bioequivalence after oral, intramuscular, and intravenous administration of racemic ketoprofen in pigs
Authors: Raekallio Marja R. , Mustonen Katja M. , Heinonen Mari L. , Peltoniemi Olli A. T. , Säkkinen Mia S. , Peltoniemi S. Marikki , Honkavaara Juhana M. , Vainio Outi M. 
Published: January 2008

Abstract
Objective—To assess bioequivalence after oral, IM, and IV administration of racemic ketoprofen in pigs and to investigate the bioavailability after oral and IM administration.
Animals—8 crossbred pigs.
Procedures—Each pig received 4 treatments in a randomized crossover design, with a 6-day washout period. Ketoprofen was administered at 3 and 6 mg/kg, PO; 3 mg/kg, IM; and 3 mg/kg, IV. Plasma ketoprofen concentrations were measured by use of high-performance liquid chromatography for up to 48 hours. To assess bioequivalence, a 90% confidence interval was calculated for the area under the time-concentration curve (AUC) and maximum plasma concentration (Cmax).
Results—Equivalence was not detected in the AUCs among the various routes of administration nor in Cmax between oral and IM administration of 3 mg/kg. The bioavailability of ketoprofen was almost complete after each oral or IM administration. Mean ± SD Cmax was 5.09 ± 1.41 μg/mL and 7.62 ± 1.22 μg/mL after oral and IM doses of 3 mg/kg, respectively. Mean elimination half-life varied from 3.52 ± 0.90 hours after oral administration of 3 mg/kg to 2.66 ± 0.50 hours after IV administration. Time to peak Cmax after administration of all treatments was approximately 1 hour. Increases in AUC and Cmax were proportional when the orally administered dose was increased from 3 to 6 mg/kg.
Conclusions and Clinical Relevance—Orally administered ketoprofen was absorbed well in pigs, although bioequivalence with IM administration of ketoprofen was not detected. Orally administered ketoprofen may have potential for use in treating pigs.
Pharmacokinetics of voriconazole after oral administration of single and multiple doses in African grey parrots (Psittacus erithacus timneh)
Authors: Flammer Keven , Nettifee Osborne Julie A. , Webb Donna J. , Foster Laura E. , Dillard Stacy L. , Davis Jennifer L. 
Published: January 2008

Abstract
Objective—To determine the pharmacokinetics and safety of orally administered voriconazole in African grey parrots.
Animals—20 clinically normal Timneh African grey parrots (Psittacus erithacus timneh).
Procedures—In single-dose trials, 12 parrots were each administered 6, 12, and 18 mg of voriconazole/kg orally and plasma concentrations of voriconazole were determined via high-pressure liquid chromatography. In a multiple-dose trial, voriconazole (18 mg/kg) was administered orally to 6 birds every 12 hours for 9 days; a control group (2 birds) received tap water. Treatment effects were assessed via observation, clinicopathologic analyses (3 assessments), and measurement of trough plasma voriconazole concentrations (2 assessments).
Results—Voriconazole's elimination half-life was short (1.1 to 1.6 hours). Higher doses resulted in disproportional increases in the maximum plasma voriconazole concentration and area under the curve. Trough plasma voriconazole concentrations achieved in the multiple-dose trial were lower than those achieved after administration of single doses. Polyuria (the only adverse treatment effect) developed in treated and control birds but was more severe in the treatment group.
Conclusions and Clinical Relevance—In African grey parrots, voriconazole has dose-dependent pharmacokinetics and may induce its own metabolism. Oral administration of 12 to 18 mg of voriconazole/kg twice daily is a rational starting dose for treatment of African grey parrots infected with Aspergillus or other fungal organisms that have a minimal inhibitory concentration for voriconazole ≤ 0.4 μg/mL. Higher doses may be needed to maintain plasma voriconazole concentrations during long-term treatment. Safety and efficacy of various voriconazole treatment regimens in this species require investigation.
Hypertension and insulin resistance in a mixed-breed population of ponies predisposed to laminitis
Authors: Bailey Simon R. , Habershon-Butcher Jocelyn L. , Ransom Kathryn J. , Elliott Jonathan , Menzies-Gow Nicola J. 
Published: January 2008

Abstract
Objective—To determine the metabolic phenotype of a group of laminitis-prone ponies when at pasture in summer, compared with when at pasture in winter.
Animals—40 ponies of various breeds predisposed to recurrent pasture-associated laminitis and 40 unaffected control ponies.
Procedures—Body condition score and size of the crest of the neck were assessed, blood samples obtained, and blood pressure measured by use of an indirect oscillometric technique, while ponies were kept on winter pasture (last week of November or beginning of December) and again on summer pasture (June). Serum insulin concentration and plasma glucose, triglyceride, uric acid, and ACTH concentrations were measured. Insulin sensitivity was calculated with proxies derived from basal serum insulin and plasma glucose concentrations.
Results—No significant differences were apparent between ponies predisposed to laminitis and control ponies during winter. However, in June, laminitis-prone ponies had increased serum insulin concentration and plasma triglyceride and uric acid concentrations, compared with control ponies. Also, laminitis-prone ponies were relatively insulin resistant, compared with control ponies. Mean blood pressure was significantly higher during summer in laminitis-prone ponies (median [interquartile range], 89.6 mm Hg [78.3 to 96.9 mm Hg]), compared with control ponies (76.8 mm Hg [69.4 to 85.2 mm Hg]).
Conclusions and Clinical Relevance—Summer pastures appear to induce metabolic responses in some ponies, leading to expression of the prelaminitic phenotype, which includes hypertension as well as insulin resistance. Signs of this metabolic syndrome may not be apparent in affected ponies during periods of grazing winter pasture. Understanding this syndrome may enable improved countermeasures to be devised to prevent laminitis.