Standardized Conditions (standardized + condition)

Distribution by Scientific Domains


Selected Abstracts


Increased fat oxidation and regulation of metabolic genes with ultraendurance exercise

ACTA PHYSIOLOGICA, Issue 1 2007
J. W. Helge
Abstract Aim:, Regular endurance exercise stimulates muscle metabolic capacity, but effects of very prolonged endurance exercise are largely unknown. This study examined muscle substrate availability and utilization during prolonged endurance exercise, and associated metabolic genes. Methods:, Data were obtained from 11 competitors of a 4- to 5-day, almost continuous ultraendurance race (seven males, four females; age: 36 ± 11 years; cycling o2peak: males 57.4 ± 5.9, females 48.1 ± 4.0 mL kg,1 min,1). Before and after the race muscle biopsies were obtained from vastus lateralis, respiratory gases were sampled during cycling at 25 and 50% peak aerobic power output, venous samples were obtained, and fat mass was estimated by bioimpedance under standardized conditions. Results:, After the race fat mass was decreased by 1.6 ± 0.4 kg (11%; P < 0.01). Respiratory exchange ratio at the 25 and 50% workloads decreased (P < 0.01) from 0.83 ± 0.06 and 0.93 ± 0.03 before, to 0.71 ± 0.01 and 0.85 ± 0.02, respectively, after the race. Plasma fatty acids were 3.5 times higher (from 298 ± 74 to 1407 ± 118 ,mol L,1; P < 0.01). Muscle glycogen content fell 50% (from 554 ± 28 to 270 ± 25 nmol kg,1 d.w.; n = 7, P < 0.01), whereas the decline in muscle triacylglycerol (from 32 ± 5 to 22 ± 3 mmol kg,1 d.w.; P = 0.14) was not statistically significant. After the race, muscle mRNA content of lipoprotein lipase and glycogen synthase increased (P < 0.05) 3.9- and 1.7-fold, respectively, while forkhead homolog in rhabdomyosarcoma, pyruvate dehydrogenase kinase 4 and vascular endothelial growth factor mRNA tended (P < 0.10) to be higher, whereas muscle peroxisome proliferator-activated receptor , co-activator-1, mRNA tended to be lower (P = 0.06). Conclusion:, Very prolonged exercise markedly increases plasma fatty acid availability and fat utilization during exercise. Exercise-induced regulation of genes encoding proteins involved in fatty acid recruitment and oxidation may contribute to these changes. [source]


Cardiac function and antiepileptic drug treatment in the elderly: A comparison between lamotrigine and sustained-release carbamazepine

EPILEPSIA, Issue 8 2009
Erik Saetre
Summary Purpose:, To investigate the comparative effects of carbamazepine (CBZ) and lamotrigine (LTG) on electrocardiography (ECG) parameters in elderly patients with newly diagnosed epilepsy. Methods:,, The study was conducted in the Norwegian subcohort (n = 108) of an international randomized double-blind 40-week trial, which compared the efficacy and tolerability of LTG and sustained-release CBZ in patients aged 65 and older with newly diagnosed epilepsy. Target maintenance doses were 400 mg/day for CBZ and 100 mg/day for LTG, with adjustments based on clinical response. Patients with significant unpaced atrioventricular (AV) conduction defect were excluded. Resting 12-lead ECG recordings were made under standardized conditions at pretreatment (baseline) and at the 40-week study visit (treatment visit). Changes in QRS interval (primary endpoint), heart rate (HR), PQ, and QTc (HR-corrected QT) intervals were assessed and compared between groups. Results:, Of the 108 patients randomized, 33 discontinued prematurely because of adverse events (n = 24, none of which was cardiac) or other reasons (n = 9), and 15 were nonevaluable due to incomplete ECG data. None of the assessed ECG parameters differed significantly between groups at baseline. No significant ECG changes were recorded between baseline and treatment visit for QRS duration and QTc intervals, whereas HR fell and PQ intervals increased slightly on both treatments. However, there were no differences between groups in changes from baseline to treatment visit. There were no significant relationships between individual ECG changes and serum drug concentrations, except for QTc intervals, which decreased slightly with increasing CBZ concentrations. The proportion of patients with ECG parameters outside the normal range at treatment visit was similar to that recorded at baseline. Discussion:, Clinically significant ECG changes are not common during treatment with CBZ or LTG in elderly patients with no preexisting significant AV conduction defects. [source]


TAIL SHEDDING IN ISLAND LIZARDS [LACERTIDAE, REPTILIA]: DECLINE OF ANTIPREDATOR DEFENSES IN RELAXED PREDATION ENVIRONMENTS

EVOLUTION, Issue 5 2009
Panayiotis Pafilis
The ability of an animal to shed its tail is a widespread antipredator strategy among lizards. The degree of expression of this defense is expected to be shaped by prevailing environmental conditions including local predation pressure. We test these hypotheses by comparing several aspects of caudal autotomy in 15 Mediterranean lizard taxa existing across a swath of mainland and island localities that differ in the number and identity of predator species present. Autotomic ease varied substantially among the study populations, in a pattern that is best explained by the presence of vipers. Neither insularity nor the presence of other types of predators explain the observed autotomy rates. Final concentration of accumulated tail muscle lactate and duration of movement of a shed tail, two traits that were previously thought to relate to predation pressure, are in general not shaped by either predator diversity or insularity. Under conditions of relaxed predation selection, an uncoupling of different aspects of caudal autotomy exists, with some elements (ease of autotomy) declining faster than others (duration of movement, lactate concentration). We compared rates of shed tails in the field against rates of laboratory autotomies conducted under standardized conditions and found very high correlation values (r > 0.96). This suggests that field autotomy rates, rather than being a metric of predatory attacks, merely reflect the innate predisposition of a taxon to shed its tail. [source]


Three phosphor plate systems and film compared for imaging root canals

INTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2001
A. C. Shearer
Abstract Aim The aim of this study was to compare three phosphor plate intraoral imaging systems (Digora (DA), Digident (DT), Denoptix (DX)) and E-speed conventional film (CF) for the imaging of root canals. Methodology Sixty extracted permanent teeth were exposed using CF, DA, DT and DX. The length of root canal visible from its most apical extent to a line drawn at the level of the cementoenamel junction was measured and this was expressed as a percentage of the distance between the radiographic apex and the cementoenamel line. All images were examined concurrently by two examiners. Films were viewed under standardized conditions and DA, DT and DX images were viewed directly from the monitor screen. The images on the monitor were enhanced to give the subjectively clearest image. Results The mean percentage of canal visible on CF was 90%, DA 78%, DT 81% and DX 83%. The difference was significant for CF,DA (P < 0.001) and CF,DT (P = 0.001). There was no statistically significant difference for CF,DX or between any of the three phosphor plate imaging systems. Conclusions It is concluded that a greater length of root canal was visible on conventional film than on three phosphor plate imaging systems and that this may be of clinical significance. [source]


Influence of residual milk-clotting enzyme and proteolysis on melting properties of soft cheese

INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2007
M C CANDIOTI
In this work, we assessed the influence of coagulant residual activity and primary proteolysis on Cremoso Argentino cheese melting properties. For that purpose, we made Cremoso soft cheeses using different amounts of coagulant, and also obtained samples in which milk-clotting enzyme was inactivated. Primary proteolysis correlated with residual activity of coagulant in early stages of cheese ripening; however, it was similar in all cheeses after 30 days. The hydrolysis of caseins did not significantly affect the melting ability of the cheeses, expressed as the area increase after heating samples under standardized conditions. Samples with similar proximate composition showed some changes in meltability; those seemed related to pH evolution during ripening. [source]


In vitro evaluation of novel low abrasive air polishing powders

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2003
G. J. Petersilka
Abstract Aim of the study: Though efficient in stain and plaque removal, air polishing is highly abrasive on root cementum or dentin even if working parameters are adjusted to minimize damage. As abrasiveness is also influenced by the physical properties of the powders used, the aim of the study was to evaluate the safety of novel low abrasive air polishing powders in vitro. Material and methods: Using four novel air polishing powders (A, B, C and D) and a standard sodium bicarbonate (NaHCO3) powder, roots of 126 extracted teeth were air polished under standardized conditions at various working parameter combinations (distance: 2 mm, 4 mm and 6 mm; powder and water setting: low, medium and high) at an angulation of 90° for 20 s. Instrumentation was performed in triplicate; resulting root defects were quantified laser-optically. Results: Mean defect depths after application of powders A, B, C and D were significantly lower than with standard powder (A: 17.9 ± 10.9 µm, B: 48.2 ± 32.7 µm, C: 92.5 ± 57.9 µm, D: 33.9 ± 19.6 µm, NaHCO3: 163.1 ± 71.1 µm) (Kruskal,Wallis test). Among the experimental powders, D was transported most reliably in the air polishing unit and allowed complete removal of disclosed plaque as assessed on freshly extracted teeth. Conclusion: The novel air polishing powder D is of low abrasiveness to root cementum and dentin while being effective in removing dental plaque. Thus, it may be useful for safe and efficient plaque removal on exposed root surfaces. [source]


Temperature adaptation in a geographically widespread zooplankter, Daphnia magna

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2000
Mitchell
Evidence for temperature adaptation in Daphnia magna was inferred from variation in the shape of temperature reaction norms for somatic growth rate, a fitness-related trait. Ex-ephippial clones from eight populations across Europe were grown under standardized conditions after preacclimation at five temperatures (17,29 °C). Significant variation for grand mean growth rates occurred both within populations (among clones) and between populations. Genetic variation for reaction norm shape was found within populations, with temperature-dependent trade-offs in clone relative fitness. However, the population average responses to temperature were similar, following approximately parallel reaction norms. The among-population variation is not evidence for temperature adaptation. Lack of temperature adaptation at the population level may be a feature of intermittent populations where environmentally terminated diapause can entrain the planktonic stage of the life-history within a similar range of temperatures. [source]


Tensile bond strengths of four different dentin adhesives on irradiated and non-irradiated human dentin in vitro

JOURNAL OF ORAL REHABILITATION, Issue 9 2001
C. R. Gernhardt
This study evaluated the influence of irradiation on dentin bond strength. Sixty irradiated and 60 non-irradiated human third molars were used. The irradiation dose of 60 Gy was fractionally applied over 6 weeks (2 Gy day,1, 5 days week,1). All teeth were prepared in a special manner allowing the simulation of intra-pulpal pressure and dentin perfusion. Dentin specimens with a thickness of 2·0 mm were obtained under standardized conditions. The specimens were randomly assigned to four experimental groups. Tensile bond strength of four different dentin bonding agents (ScotchbondŌ 1, Solobond Plus®, Prime&BondŌ 2·1 and Syntac®) was evaluated using an Instron Universal testing machine. Pairwise comparison did not show any significant differences between the irradiated and non-irradiated groups. The influence of the different dentin adhesives was significant (P=0·0001; ANOVA). Compared with Solobond Plus® and Prime&BondŌ 2·1, the use of ScotchbondŌ 1 resulted in a significantly higher tensile bond strength in non-irradiated specimen (P< 0·05; closed test procedure based on Kruskal,Wallis test). Within the limitations of an in vitro study, it can be concluded that adhesive restoration procedures can be successfully used in patients irradiated for cancer of the head and neck. [source]


High concentrations of the melatonin metabolite, N1 -acetyl- N,2 -formyl-5-methoxykynuramine, in cerebrospinal fluid of patients with meningitis: a possible immunomodulatory mechanism

JOURNAL OF PINEAL RESEARCH, Issue 3 2005
Sueli De Oliveira Silva
Abstract:, We evaluated the presence of the melatonin metabolite N1 -acetyl- N2 -formyl-5-methoxykynuramine (AFMK), in cerebrospinal fluid (CSF) of patients with viral meningitis (n = 20) and control samples (n = 8) and correlate AFMK levels with inflammatory markers such as cellularity, protein, tumor necrosis factor (TNF)- ,, interleukin (IL)-8 and IL-1, levels. A portion of the CSF was extracted with dichloromethane (1:5) and analyzed by high-performance liquid chromatography (HPLC) under standardized conditions for AFMK. AFMK was detected in 16 of 20 CSF samples of patients with viral meningitis; the concentration of AFMK was found to be above the quantification limit (50 nmol/L) in six of these samples. AFMK was not detected in any of the eight control samples. The samples were classified into groups according to AFMK levels: undetectable (<10 nmol/L, group I), detectable but below the quantification limit (< 50 nmol/L, group II), and quantified (>50 nmol/L, group III). Group II presented the highest levels of proteins and IL-8, whereas group III showed the lowest levels of the inflammatory parameters. This study supports our hypothesis that inflammation favors the formation of AFMK and that this compound has immunomodulatory activity in vivo. [source]


An Analysis of the Effect of a Vent Hole on Excess Cement Expressed at the Crown,Abutment Margin for Cement-Retained Implant Crowns

JOURNAL OF PROSTHODONTICS, Issue 1 2009
Dipan Patel BDS
Abstract Purpose: The labial margins of anterior implant-retained crowns are often positioned subgingivally for a superior esthetic appearance. One of the consequences of subgingival margins is the increased risk of leaving excess cement behind following cementation. This can lead to potential problems, including peri-implant inflammation, soft tissue swelling, soreness, bleeding or suppuration on probing, and bone loss. The purpose of this laboratory study was to investigate the effect of placement, location, and diameter of a vent hole on the amount of cement being expressed at the margin of an anterior implant abutment-retained crown. Materials and Methods: Three implant crown copings were fabricated to fit on the same custom abutment. Three vent diameters (0.75, 1.25, and 1.65 mm) and three locations on the palatal surface of the coping (cervico-palatally, mid-palatally, inciso-palatally) were chosen for vent hole placement. For each test, the coping was cemented onto the abutment under standardized conditions. A preweighed thin coating of cement was applied to the fit surface of the coping. The amount of cement expressed at the margin and vent hole was measured by weight and calculated as a proportion of the amount of cement placed in the coping before seating. The procedure was completed 15 times for each variable. The results were statistically analyzed using univariate ANOVA with post hoc Bonferroni-adjusted independent samples t -tests. Results: The presence of a vent hole influenced the proportion of cement expressed at the coping margin (p < 0.05). The location of a vent hole influenced the proportion of cement expressed at the coping margin (p < 0.05), with the exception of the mid-palatal and inciso-palatal positioning where there was no significant difference (p= 0.61) between groups. The diameter of the vent hole did not significantly influence the proportion of cement expressed at the coping margin (p= 0.096). Conclusions: When using anterior cement-retained implant crowns, the use of a 0.75-mm mid-palatal or inciso-palatal vent hole to minimize the amount of cement expressed at the margin during cementation should be considered. [source]


Microvascular Display of Xanthine Oxidase and NADPH Oxidase in the Spontaneously Hypertensive Rat

MICROCIRCULATION, Issue 7 2006
FRANK A. DELANO
ABSTRACT Objective: Oxygen free radical production in hypertension may be associated with elevated arteriolar tone and organ injury. Previous results suggest an enhanced level of oxygen free radical formation in microvascular endothelium and in circulating neutrophils associated with xanthine oxidase activity in the spontaneously hypertensive rats (SHR) compared with their normotensive controls, the Wistar Kyoto rats (WKY). The aim of this study was to gain more detailed understanding of where oxidative enzymes are located in the microcirculation. Methods: An approach was developed to delineate the cellular distribution of two selected oxidative enzymes, xanthine oxidase and nicotinamide adenine dinucleotide phosphate (NADPH) dependent oxidase (protein 67-kDa fraction). Immunolabeling with peroxidase substrate was utilized, which permits full delineation of the primary antibody in all microvascular structures of the mesentery. Results: Xanthine oxidase is present in the endothelium of all segments of the microcirculation, in mast cells, and in parenchymal cells of the mesentery. NADPH oxidase can be detected in the endothelium, leukocytes, and mast cells and with lower levels in parenchymal cells. The mesentery of WKY and SHR has similar enzyme distributions with enhancements on the arteriolar and venular side of the microcirculation that coincide with the sites of enhanced free radical production recently reported. Immune label measurements under standardized conditions indicate that both enzymes are significantly enhanced in the SHR. Adrenalectomy, which serves to reduce the blood pressure and free radical production of the SHR to normotensive levels, leads to a reduction of NADPH and xanthine oxidase to normotensive levels, while supplementation of adrenalectomized SHR with dexamethasone significantly increases the oxidase expression in several parts of the microcirculation to levels above the WKY rats. Conclusion: The results indicate that enhanced expression of NADPH and xanthine oxidase in the SHR depends on an adrenal pathway that is detectable in the arteriolar and venular network at high and low pressure regions of the circulation. [source]


Identification of differentially expressed root genes upon rhizomania disease

MOLECULAR PLANT PATHOLOGY, Issue 6 2008
LAURE SCHMIDLIN
SUMMARY Rhizomania is one of the most devastating sugar beet diseases. It is caused by Beet necrotic yellow vein virus (BNYVV), which induces abnormal rootlet proliferation. To understand better the physiological and molecular basis of the disorder, transcriptome analysis was performed by restriction fragment differential display polymerase chain reaction (RFDD-PCR), which provided differential gene expression profiles between non-infected and infected sugar beet roots. Two distinct viral isolates were used to detect specific or general virus-induced genes. Differentially expressed genes were selected and identified by sequence analysis, followed by reverse Northern and reverse transcriptase PCR experiments. These latter analyses of different plants (Beta vulgaris and Beta macrocarpa) infected under distinct standardized conditions revealed specific and variable expressions. Candidate genes were linked to cell development, metabolism, defence signalling and oxidative stress. In addition, the expression of already characterized genes linked to defence response (pathogenesis-related protein genes), auxin signalling and cell elongation was also studied to further examine some aspects of the disease. Differential expression was retrieved in both B. vulgaris and B. macrocarpa. However, some candidate genes were found to be deregulated in only one plant species, suggesting differential response to BNYVV or specific responses to the BNYVV vector. [source]


Probing genetic algorithms for feature selection in comprehensive metabolic profiling approach

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2008
Wei Zou
Six different clones of 1-year-old loblolly pine (Pinus taeda L.) seedlings grown under standardized conditions in a green house were used for sample preparation and further analysis. Three independent and complementary analytical techniques for metabolic profiling were applied in the present study: hydrophilic interaction chromatography (HILIC-LC/ESI-MS), reversed-phase liquid chromatography (RP-LC/ESI-MS), and gas chromatography all coupled to mass spectrometry (GC/TOF-MS). Unsupervised methods, such as principle component analysis (PCA) and clustering, and supervised methods, such as classification, were used for data mining. Genetic algorithms (GA), a multivariate approach, was probed for selection of the smallest subsets of potentially discriminative classifiers. From more than 2000 peaks found in total, small subsets were selected by GA as highly potential classifiers allowing discrimination among six investigated genotypes. Annotated GC/TOF-MS data allowed the generation of a small subset of identified metabolites. LC/ESI-MS data and small subsets require further annotation. The present study demonstrated that combination of comprehensive metabolic profiling and advanced data mining techniques provides a powerful metabolomic approach for biomarker discovery among small molecules. Utilizing GA for feature selection allowed the generation of small subsets of potent classifiers. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Upregulation of TNF Receptor Type 2 in Human and Experimental Renal Allograft Rejection

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009
U. Hoffmann
An important role of TNF interacting with TNFR2 has been shown in different models of ischemic, nephrotoxic and immune-mediated renal injury. To systematically evaluate the expression of TNFR2 in renal allograft rejection, we investigated human renal allograft biopsies and, in addition, established an experimental transplantation model in rats to verify the human data under standardized conditions. The expression of TNFR2 was analyzed in 96 human renal allograft biopsies with different disease entities. In a 6-day and a 28-day experimental protocol, TNFR2 was examined in kidney specimens and in the urine of control, uni-nephrectomized and transplanted rats ± cyclosporine treatment (n = 114). In human biopsies and in rat allografts on day 6 with acute allograft rejection, significantly elevated expression of TNFR2 was observed in tubular epithelial cells, podocytes, B cells and monocytes/macrophages. The expression level was associated with renal function. The TNFR2 expression level at day 28 was significantly lower compared to day 6. TNFR2 is markedly upregulated both in human and experimental acute renal allograft rejection. Our data are robust and consistent between different species, suggesting a role for TNFR2 in the early course of rejection. [source]


The circulating IGF system and its relationship with 24-h glucose regulation and insulin sensitivity in healthy subjects

CLINICAL ENDOCRINOLOGY, Issue 6 2003
Jan Frystyk
Summary objective and design It has been suggested that circulating free IGF-I participates in glucose homeostasis and that IGFBP-1 reflects changes in insulin sensitivity. To study this further, we examined 10 healthy, nonobese subjects under standardized conditions for 24 h with and without an intravenous infusion of glucose, the latter in order to augment insulin sensitivity. Serum was collected every 2 h for analysis of free and total IGFs, IGFBP-1, , 2 and , 3 and the acid labile subunit (ALS). Insulin sensitivity was estimated at the end of each 24-h study period by use of the hyperinsulinaemic euglycaemic clamp technique. results Glucose infusion resulted in mild hyperglycaemia (P < 0·0001), a reduction in IGFBP-1 by approximately 40% (P < 0·0003), and increased insulin and C-peptide levels (P < 0·0001). Glucose infusion also increased insulin sensitivity (P < 0·003). However, despite the reduction in IGFBP-1, glucose infusion did not increase free IGF-I over the control level, and free IGF-II was slightly reduced (P < 0·02). Irrespective of glucose infusion, free IGF-I and -II remained stable during daytime (i.e. they were unresponsive to meal-related changes in plasma glucose), but both free fractions decreased during the night, reaching nadir at 04·00 h. None of the other members of the IGF system showed any relationship with plasma glucose levels. Finally, we failed to observe any relationship between changes in insulin sensitivity and the circulating IGF system. conclusion We found no evidence that the circulating IGF system is involved in meal-related blood glucose regulation or that it reflects short-term changes in insulin sensitivity in healthy, nonobese subjects. However, we cannot preclude that the observed changes in circulating IGFBP-1 may affect the glucose-lowering effect of IGF-I and -II at the local tissue level. [source]