Home About us Contact
|
Home About us Contact | ||
|
|
||
Present Study Support (present + study_support)
Selected AbstractsModulation of plasma lipid levels affects benzo[a]pyrene-induced DNA damage in tissues of two hyperlipidemic mouse modelsENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2003Daniëlle M.J. Curfs Abstract The role of plasma lipids in the uptake, transportation, and distribution of lipophilic carcinogens like benzo[a]pyrene (B[a]P) remains unclear. Therefore, we studied the effects of dietary-modulated plasma lipids on B[a]P-induced DNA damage in several organs of two hyperlipidemic mouse models. Male apolipoprotein E (ApoE)*3-Leiden (n = 22) and ApoE knockout (ApoE-KO) mice (n = 20) were fed a high-fat cholesterol (HFC) diet or low-fat cholesterol (LFC; standard mouse chow) diet for 3 weeks, after which the animals were exposed to a single oral dose of 5 mg/kg bw B[a]P or vehicle and killed 4 days later. Plasma lipids were determined and DNA adducts were measured in aorta, heart, lung, liver, brain, and stomach. Total cholesterol and low-density lipoprotein (LDL) cholesterol were increased in all animals on a HFC diet, whereas a decrease of triglycerides was seen only in the ApoE-KO mice. In ApoE-KO mice on a normal diet, DNA-adduct levels were highest in aorta (10.8 ± 1.4 adducts/108 nucleotides), followed by brain (7.8 ± 1.3), lung (3.3 ± 0.7), heart (3.1 ± 0.6), liver (1.5 ± 0.2) and stomach (1.2 ± 0.2). In the ApoE*3-Leiden mice, adduct levels were equally high in aorta, heart, and lung (4.6 ± 0.7, 5.0 ± 0.5 and 4.6 ± 0.4, respectively), followed by stomach (2.7 ± 0.4), brain (2.3 ± 0.2), and liver (1.7 ± 0.2). In the ApoE-KO mice, the HFC diet intervention resulted in lower adduct levels in lung (2.1 ± 0.2), heart (1.9 ± 0.2), and brain (2.9 ± 0.5), as compared with the LFC group. In contrast, a nonsignificant increase of adducts was found in aorta (13.1 ± 1.5). A similar but nonsignificant trend was observed in the ApoE*3-Leiden mice. Multiple regression analysis showed that in aorta, DNA adducts were inversely related to plasma triglycerides (P = 0.004) and were also modulated by the ApoE genotype (P < 0.001). The results of the present study support further investigation into the role of dietary modulation of plasma lipids, ApoE, and polycyclic aromatic hydrocarbon exposure on the formation of DNA adducts in chronic degenerative diseases. Environ. Mol. Mutagen. 42:243,249, 2003. © 2003 Wiley-Liss, Inc. [source] Cerebral dominance and schizophrenia-spectrum disorders in adults with intellectual disabilityJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 6 2000D. Rowe Abstract Studies of the general population without intellectual disability have suggested an association between atypical handedness and schizophrenia-spectrum disorders (SSDs). Mixed handedness is taken as an index of diminished cerebral dominance or laterality. The present study addressed the question of whether such findings extend to the neurodevelopmentally ,at risk' population of adults with intellectual disability and SSDs compared with appropriate controls. Fourteen patients with a dual diagnosis of intellectual disability and SSD were compared with 14 controls with intellectual disability alone. Assessments of self-reported hand preference and relative hand skill were completed. Self-report of hand preference revealed highly significantly greater mixed-handedness in the SSD group. Furthermore, relative hand skill performance was significantly diminished for the dominant hand. The discrepancy between dominant and non-dominant hand functioning was lower in the SSD group and this association was highly significant. The results of the present study support the usefulness of such detailed laterality assessment in this population. Mixed laterality, over and above that of the population with general intellectual disability and developmental disorder, was associated with SSD. These results are consistent with the neurodevelopmental hypothesis of schizophrenia and its cognitive neuropsychiatric/neuropsychological sequelae. [source] Growth and nutrient uptake of tea under different aluminium concentrationsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2008Ka Fai Fung Abstract BACKGROUND: The uptake of essential nutrients such as P, Fe, K, Ca and Mg is depressed by Al in most plants. This study aimed to investigate the concentrations at which Al could be toxic to C. sinensis. The suppression of nutrient uptake was investigated by comparing growth and nutrient uptake at different Al doses. The quantification of Al in apoplasm, symplasm and cell wall of C. sinensis was also studied. RESULTS: In the absence of Al, the growth of C. sinensis was retarded. Test doses over 1 mM Al were toxic to C. sinensis. At concentrations of 0.25 or 0.5 mM, distinct rhizostimulation was noted, and within a short period (2 weeks), the biomass of these seedlings increased by 44 and 35%, respectively, compared to 0 and 14% in control and 1 mM Al, respectively. In general, at beneficial doses (0.25, 0.5), Al stimulated the uptake of Ca, Mg, K and Mn, whereas the uptake of Fe, Cu and Zn was retarded. Fine roots of the seedlings had the highest levels of Al, compared to leaves, branches and main roots. In the root tips, most of the Al was present in the soluble fractions of the apoplasm and symplasm, and very low levels of Al was bound to the cell walls, which was in good agreement with the observed mobility of Al in C. sinensis. CONCLUSION: The results of the present study support the view that Al plays a nutritive role for C. sinensis. The rhizostimulatory effects of Al on C. sinensis have been explained as a consequence of enhanced nutrient uptake. Copyright © 2008 Society of Chemical Industry [source] Variation in the Sizes of Chthamalid Barnacle Post-Settlement Cyprids on European ShoresMARINE ECOLOGY, Issue 4 2001Ruth M. O'Riordan Abstract. As part of a wider study on the settlement and recruitment of Chthamalus spp. in Europe, this study investigated whether chthamalid cyprids can be separated by length on a European scale. Variation in cyprid length with latitude and temporal variation at selected localities were also examined. The lengths of cyprids collected between 1996,,,1999 on nine rocky shores in Europe are reported. Elminius modestus cyprids were found only at Roscoff, NW France and could be distinguished due to their carapace shape and length. They showed a unimodal length distribution, measuring between 450 and 625 µm, with no variation in length between the two sampling dates (1997 and 1998). Based on carapace shape and length, the remaining cyprids in the collections were identified as one of three chthamalid species, Chthamalus montagui, Chthamalus stellatus or Euraphia depressa. Bimodal length distributions of chthamalid cyprids were seen on some shores, while others had a single small-sized modal group (representing C. montagui on Atlantic shores and/or E. depressa in the Mediterranean) separated from a few distinctly larger cyprids (C. stellatus). Metamorphs collected simultaneously with cyprid collections were identified as C. stellatus or C. montagui, except at Roscoff, where E. modestus were also found. In southern Portugal, where all metamorphs collected were C. montagui and adult C. montagui were the dominant barnacles, most cyprids measured between 350 and 550 µm long and this size distribution coincides with the distribution expected for C. montagui. Cyprids collected on these four more southerly Portuguese shores had the same modal length class (475 µm) and this remained constant between successive years at Luz and Albufeira, Algarve. The smallest (350 µm long) wild chthamalid cyprids found were from southern Portugal and Italy. In Spain, France and Ireland the smallest chthamalid cyprid was 425 µm long. The results from the present study support the hypothesis that on Atlantic shores cyprids of C. montagui can be separated from those of C. stellatus based on size, although there is some variation in cyprid length with latitude as well as temporal variation at selected localities. [source] Trehalose metabolism in root nodules of the model legume Lotus japonicus in response to salt stressPHYSIOLOGIA PLANTARUM, Issue 4 2006Miguel López The effect of NaCl stress (50 mM) and validamycin A treatment (30 ,M) on growth and nitrogen fixation of Lotus japonicus was investigated in plants cultured under symbiotic and hydroponics conditions for teen weeks (flowering stage). Validamycin A was used as a potent trehalase inhibitor, and was able to produce a five-fold increase in the level of trehalose during salt treatment, concomitant with an enhance in biomass (20%) in salinized plants. Alterations of nodule metabolism related to some carbohydrates and some enzyme activities were also examined. The shoot and total plant dry weight were severely affected by saline conditions decreasing by 40% and only 15,20% in plant treated without or with validamycin A, respectively. Nitrogenase activity (E.C. 1.7.9.92) was inhibited almost 40% by salt stress and no effect of validamycin was observed. Based on these results, L. japonicus might be considered as a salt-sensitive legume. In addition, the saline conditions also inhibited the enzyme activities of sucrose synthase (E.C. 2.4.1.13), alkaline invertase (E.C. 3.2.1.26) and trehalose-phosphate synthetase (E.C. 2.4.1.15). The validamycin A treatment mainly decreased enzyme activities: sucrose synthase, trehalose-phosphate phosphatase (E.C. 3.1.3.12) and trehalase (E.C. 3.2.1.28). On the other hand, a high concentration of the carbohydrates, starch, sucrose and glucose, seems not to be the mechanism induced in L. japonicus to protect nodules exposed to NaCl because all these sugars decreased in such conditions. Results of the present study support the possible role of trehalose as an osmoprotectant under salt stress. [source] Civic Knowledge of High School Students in Israel: Personal and Contextual DeterminantsPOLITICAL PSYCHOLOGY, Issue 4 2007Professor Orit Ichilov Past research on civic education suggests that students' performance is largely influenced by individual socioeconomic background and motivational factors. There has been little attention to the effects of school and classroom ideological and social attributes, such as the socioeconomic make-up of the school or classroom, or how interested in politics are a student's classmates. The results of the present study support the contention that contextual effects play a vital role in determining students' civic knowledge scores. Analysis of Israeli 11th graders' performance on the International Association for the Evaluation of Educational Achievement (IEA) civic knowledge test shows that while individual backgrounds and motivations play a significant role, school and classroom contexts greatly contribute to civic knowledge acquisition. [source] Safety of Elective Hand Surgery Following Axillary Lymph Node Dissection for Breast CancerTHE BREAST JOURNAL, Issue 3 2007Dan D. Hershko MD Abstract:, The development of lymphedema is the most feared complication shared by breast cancer survivors undergoing hand surgery after prior axillary lymph node dissection (ALND). Traditionally, these patients are advised to avoid any interventional procedures in the ipsilateral upper extremity. However, the appropriateness of some of these precautions was recently challenged by some surgeons claiming that elective hand operations can be safely performed in these patients. The purpose of this study was to evaluate our experience and determine the safety of elective hand operations in breast cancer survivors. The medical records of patients operated for different hand conditions after prior breast surgery and ALND at our institution between 1983 and 2002 were reviewed. The techniques and preventive measures performed, use of antibiotics, and upper extremity complications associated with the operations were analyzed. Overall, we operated on 27 patients after prior ALND performed for breast cancer. Follow-up was available for 25 patients. Four patients had pre-existing lymphedema. The surgical technique used was similar to that performed in patients without prior ALND and antibiotic prophylaxis was not given. Delayed wound healing was observed in one patient and finger joint stiffness in another. Two patients with pre-existing lymphedema developed temporary worsening of their condition. None of the patients developed new lymphedema. The results of the present study support the few previous studies, suggesting that hand surgery can be safely performed in patients with prior ALND. Based on these findings, the appropriateness of the rigorous precautions and prohibitions regarding the care and use of the ipsilateral upper extremity may need to be reconsidered. [source] PERSPECTIVE: The World's Top Innovation Management Scholars and Their Social Capital,THE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 3 2007Jeff Thieme Using 959 articles reflecting the work of 1,179 scholars, this study ranks the world's top scholars in innovation management (IM) on the basis of the number of research articles published across 14 top academic journals in technology and innovation management, marketing, and management between 1990 and 2004. Twenty-three scholars have at least eight articles in this period. Michael Song has the most (31), followed by Robert Cooper, Roger Calantone, William Souder, and Elko Kleinschmidt, who have published at least 17 articles in the 15-year period. Surprisingly, the list of schools that either trained or currently employ these top scholars is quite different from Linton's (2004) recent ranking of the top business schools in the management of technology. Guided by social capital theory, the present study analyzes the embeddedness characteristics of IM scholars to determine the extent to which social capital explains scholarly productivity. A current controversy in the social capital literature is the embeddedness characteristics that create social capital. On the one hand, the closure perspective argues that social capital results from strong relational ties with others in a dense, local neighborhood of actors who are relatively disconnected from others. On the other hand, the brokerage perspective argues that social capital is created when actors have relational ties that span these dense, local neighborhoods. The findings in the present study support both perspectives. Furthermore, the results suggest that strategic orientation is a contingency variable that clarifies the conditions in which closure- or brokerage-based embeddedness is appropriate. Specifically, scholars pursuing an entrepreneurial publication strategy are more productive when their relational embeddedness is consistent with the brokerage perspective of social capital creation, whereas scholars pursuing a focused publication strategy are more productive when their relational embeddedness is consistent with the closure perspective of social capital creation. The results have implications for both the IM scholar community and the social capital literature. Whether IM scholars are pursuing an entrepreneurial strategy that capitalizes on emergent knowledge across various theories and perspectives or pursuing a focused strategy by concentrating on gaining deep understanding of a specific stream of research, there are many avenues and opportunities for improving publication performance through the formation of new social capital. Finally, the empirical support for the contingency variable strategic orientation is consistent with recent speculation that both perspectives are important and suggests that future work should focus on further identification and clarification of contingency factors associated with them. [source] Activation of the interferon-, signaling pathway in systemic lupus erythematosus peripheral blood mononuclear cellsARTHRITIS & RHEUMATISM, Issue 5 2009Thomas Karonitsch Objective To investigate interferon-, (IFN,) signaling in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE) by analyzing IFN, receptor (IFN,R) expression, STAT-1 expression and phosphorylation, and the regulation of IFN,-inducible genes. Methods Fluorocytometry was used to investigate expression of STAT-1, pSTAT-1, CD95, HLA,DR, class I major histocompatibility complex (MHC), IFN,-inducible 10-kd protein (IP-10), monokine induced by IFN, (Mig), and IFN,R in PBMCs from SLE patients and healthy individuals. STAT-1 phosphorylation was determined by fluorocytometry and Western blotting after stimulation with IFN, or IFN,. Quantitative polymerase chain reaction was used to assess messenger RNA (mRNA) expression of the IFN,-inducible genes IP-10 and Mig shortly after preparation or after stimulation with IFN, in monocytes. Results STAT-1 expression was increased in PBMCs from SLE patients and correlated significantly with disease activity and with the IFN-inducible expression of CD95 and HLA,DR. STAT-1 expression also showed a trend toward association with class I MHC expression. In addition, the expression of other IFN,-inducible genes, such as IP-10 or Mig, was increased in SLE monocytes. While STAT-1 phosphorylation in SLE PBMCs and PBMCs from healthy individuals was similar after IFN, stimulation, incubation with IFN, induced STAT-1 phosphorylation only in SLE lymphocytes. Moreover, SLE monocytes showed a considerably higher increase in pSTAT-1 expression upon IFN, stimulation than monocytes from healthy individuals. Increased responsiveness of SLE monocytes to IFN, was also confirmed on the mRNA level, where expression of the IFN-inducible, STAT-1,dependent genes IP-10 and Mig was more efficiently increased in SLE cells. However, IFN,R was similarly expressed on SLE lymphocytes and monocytes and those from healthy individuals. Conclusion In addition to supporting the role of IFNs in SLE immunopathogenesis in general, the findings of the present study support a role of IFN, in this disease. [source] Exhaled air temperature in asthma: methods and relationship with markers of diseaseCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2007G. L. Piacentini Summary Background Exhaled breath temperature has been proposed as a surrogate marker for the evaluation of airway inflammation in asthmatic patients. Objective The aim of the present study was to extend the investigation of exhaled air temperature as a means for the evaluation of airway inflammation using a professionally developed instrument. Methods Fifty-seven children, 41 allergic mild asthmatics and 16 healthy controls have been evaluated. They underwent exhaled air temperature and lung function measurement. The asthmatic children also underwent exhaled nitric oxide measurement, and hypertonic saline sputum induction for the evaluation of eosinophil (EOS) percentage. Results The level of exhaled temperature was significantly higher in asthmatics than in controls, being 30.18±0.14°C vs. 27.47±0.24°C (P<0.001). In asthmatic children, a positive relationship was observed between exhaled air temperature and both exhaled nitric oxide (r=0.39; P=0.01) and EOS percentage in samples from induced sputum (,=0.53; P=0.04). Conclusion The data from the present study support the hypotheses that exhaled breath temperature is related to the degree of airway inflammation in asthma. [source] ROLE OF HYPOTHALAMIC ,2 -ADRENOCEPTOR ACTIVITY IN FRUCTOSE-INDUCED HYPERTENSIONCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 10 2006Marcos A Mayer SUMMARY 1The aim of the present study was to investigate the effects of the ,2 -adrenoceptor antagonist yohimbine on blood pressure and heart rate (HR) regulation, as well as on adrenergic and serotoninergic neurotransmission, in fructose hypertensive (F) rats. 2The anterior hypothalamic area of control (C) and F rats was perfused with Ringer's solution containing 10 and 100 µg/mL yohimbine through a microdialysis concentric probe. The effects of yohimbine on mean arterial pressure (MAP) and HR, as well as on hypothalamic dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole acetic acid (5-HIAA) levels, were measured according to perfusion time. 3Although intrahypothalamic perfusion of yohimbine increased blood pressure in C rats (,MAP 9 ± 1 and 11 ± 2 mmHg for 10 and 100 µg/mL yohimbine, respectively; P < 0.05 vs Ringer's perfusion), the ,-adrenoceptor antagonist did not modify MAP in F. Intrahypothalamic yohimbine had no effect on HR at either concentration tested. Intrahypothalamic perfusion of 10 and 100 µg/mL yohimbine increased DOPAC levels in C rats (135 ± 6 and 130 ± 5% of basal levels, respectively; both n = 6; P < 0.05 vs Ringer's perfusion), but not in F animals (115 ± 6 and 102 ± 6% of basal levels, respectively; both n = 6). In both C and F rats, yohimbine administration induced an increase in 5-HIAA dialysate levels. 4The results of the present study support the notion that ,2 -adrenoceptor tone of the anterior hypothalamus of normotensive rats, which contributes to normal blood pressure regulation, is not involved in the control of HR in either normotensive C or hypertensive F rats. The absence of changes in MAP after yohimbine perfusion in F rats suggests that the ,2 -adrenoceptor tone could be decreased in this group of rats and that this may be responsible for the maintenance of hypertension in this model. Intrahypothalamic perfusion of yohimbine increased DOPAC in the dialysate only in C rats, suggesting changes in presynaptic ,2 -adrenoceptor activity in fructose-overloaded rats. Conversely, increased 5-HIAA levels did not differ between C and F groups. [source] Screening of Cushing's syndrome in adult patients with newly diagnosed diabetes mellitusCLINICAL ENDOCRINOLOGY, Issue 2 2007Giuseppe Reimondo Summary Objective Recent studies have shown that a relatively high number of diabetic patients may have unsuspected Cushing's syndrome (CS). The aim of the present study was to screen for CS in adult patients with newly diagnosed diabetes mellitus who were not selected for clinical characteristics, such as poor control and obesity, which may increase the pre-test probability of CS. Design, patients and measurement We prospectively evaluated 100 consecutive diabetic patients at diagnosis from 2003 to 2004. No patient had clear Cushingoid features. Screening was performed by using the overnight 1-mg dexamethasone suppression test (DST) after complete recovery from acute concomitant illnesses and attainment of satisfactory glycaemic control. The threshold of adequate suppression after DST was set at 110 nmol/l. Results Five patients failed to suppress cortisol after DST and underwent a repeated DST and a confirmatory standard 2-day, 2-mg DST after 3,6 months from the baseline evaluation. In one woman, a definitive diagnosis of CS was made by a surgically proven pituitary adenoma, and glycaemic control improved after cure of CS. Conclusions The results of the present study support the view that unknown CS is not rare among patients with diabetes mellitus. This is the first demonstration that screening for CS may be feasible at the clinical onset of diabetes in an unselected cohort of patients. Therefore, early diagnosis and treatment of CS may provide the opportunity to improve the prognosis of diabetes. [source] Impaired GH secretion to provocative stimuli in two families with hypocalciuric hypercalcaemiaCLINICAL ENDOCRINOLOGY, Issue 5 2003Elisabetta Cecconi Summary objective, To determine whether hypercalcemia per se might be responsible for an impairment in GH secretion. design, Prospective study. patients, Six subjects of two unrelated families with familial hypocalciuric hypercalcaemia (FHH), an autosomal dominant disorder due to inactivating mutations in the calcium receptor gene, leading to an increase in serum calcium levels and inappropriately normal serum PTH concentrations. Forty normal subjects, matched for sex and age served as controls. measurements, Serum GH concentrations were measured after GHRH-Arginine (GHRH-Arg) stimulation test; serum IGF-I, ACTH, cortisol, FT4, FT3, TSH, PRL, LH, FSH levels were measured under basal conditions. results, All subjects (two male, four female, age range 24,74 years) had increased serum ionized calcium levels (range 1·36,1·56 mmol/l) and five of six patients had normal PTH levels (range for all patients was 14,68 ng/l). Basal serum GH concentrations ranged from 0·1 to 7·0 µg/l. Mean serum GH secretory peak after GHRH-Arg stimulation test was reduced in five subjects (mean 9·3 ± 3·6 µg/l, P < 0·006 vs. Controls, mean 67·0 ± 44·0 µg/l, cut-off, 16·0 µg/l) and normal in one subject (38·7 µg/l). However, serum IGF-I levels were reduced only in two patients (29 and 57 µg/l) and normal in four subjects (range 127,208 µg/l). The basal secretion of the other anterior pituitary hormones was within their normal ranges. conclusions, The results of the present study support the concept that elevated serum calcium levels impair GH secretion. However, the clinical relevance of GH deficiency in FHH remains to be elucidated. [source] | |||||||||||||