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Sample records for acute volume overload

  1. Volume Overload in Heart Failure: An Evidence-Based Review of Strategies for Treatment and Prevention.

    PubMed

    Houston, Brian A; Kalathiya, Rohan J; Kim, Daniel A; Zakaria, Sammy

    2015-09-01

    Acute decompensated heart failure is the leading cause of hospital admission in the United States, with a high risk of readmission within 30 days. Most acute decompensated heart failure admissions are driven by congestive signs and symptoms resulting from fluid and sodium overload. We reviewed the evidence base addressing the management and prevention of fluid overload in heart failure, focusing on recent clinical trials. All the references in this review were obtained through PubMed and had at least 1 of the following key words: heart failure and volume overload, congestion, loop diuretics, thiazide diuretics, aldosterone antagonists, dopamine, cardiorenal syndrome, nesiritide, vasopressin antagonists, ultrafiltration, sodium restriction, fluid restriction, telemonitoring, and invasive hemodynamic monitoring. We also reviewed relevant references cited in the obtained articles, especially articles addressing methods of treating or preventing volume overload in patients with heart failure. PMID:26189443

  2. Overloaded phase-code multiplexing for volume holographic storage.

    PubMed

    Berger, Gernot; Dietz, Mathias; Denz, Cornelia

    2008-06-01

    Overloaded phase codes for volume holographic data storage are introduced. In contrast to any previous phase-code design, overloaded phase codes enable multiplexing of a number of data pages that exceeds the number of utilized reference beams. In this way the achievable data capacity can be augmented. Overloaded codes are generated by extending multilevel phase codes based on the discrete Fourier transform. We demonstrate multiplexing of 70 analog pages by means of 64 reference beams. The analysis of reconstructed digital data pages suggests that a capacity gain of up to 15% is reasonable. PMID:18516191

  3. The Relationship Between Volume Overload in End-Stage Renal Disease and Obstructive Sleep Apnea.

    PubMed

    Roumelioti, Maria-Eleni; Brown, Lee K; Unruh, Mark L

    2015-01-01

    Obstructive sleep apnea (OSA) is common, underdiagnosed, and undertreated among patients with end-stage renal disease (ESRD). As in all cases, pathogenesis of OSA is related to repeated upper airway (UA) occlusion or narrowing, but in ESRD, additional contributory factors likely include uremic destabilization of central respiratory control and anatomic changes in the UA related to fluid status. Pulmonary congestion is common in acute and chronic kidney failure and is a consequence of cardiomyopathy and fluid overload, two potentially reversible risk factors. Emerging evidence suggests that volume overload also reduces the UA caliber. The diminution in UA area as well as destabilization of ventilatory control in ESRD have been postulated as causes of increased OSA prevalence and severity in these patients, and creates a vicious cycle wherein OSA exacerbates fluid overload disorders such as in congestive heart failure (CHF) and ESRD, which then further worsen OSA. Dialysis modalities may differ in their effects on volume status, the accumulation of uremic toxins, and acid-base status, and as a consequence, on the emergence and severity of OSA. Given the contribution of excess fluid to both the severity of nocturnal hypoxia and UA narrowing, establishing and maintaining dry weight is of particular importance when managing OSA in ESRD. Clinical trials to determine the extent to which more aggressive fluid removal in ESRD patients may alleviate OSA are needed. PMID:25940851

  4. The MR appearance of volume overload in the lower extremities

    NASA Technical Reports Server (NTRS)

    Meler, J. D.; Solomon, M. A.; Steele, J. R.; Yancy, C. W. Jr; Parkey, R. W.; Fleckenstein, J. L.; Blomqvist, C. G. (Principal Investigator)

    1997-01-01

    PURPOSE: Our goal was to describe the MR findings of volume overload (VO) in the lower extremities. METHOD: Fifteen individuals were studied, including eight healthy controls and seven patients with VO (four cardiac, three renal). MR evaluation included various SE techniques. Edema detection, localization, and symmetry were assessed subjectively. Relaxation time estimates were also made of the subcutaneous tissue, marrow, and three muscles. RESULTS: Subcutaneous tissue was markedly edematous in seven of seven patients and asymmetric in four of seven, whereas marrow was normal in all patients. Muscle edema was mild and asymmetric in six and two of seven patients, respectively. Perifascial fluid collections were identified in six of seven patients. CONCLUSION: Subcutaneous tissue edema is the dominant feature of VO in the lower extremities. Perifascial fluid is common but does not necessarily distribute symmetrically. Muscle edema is relatively mild. These findings should aid in identifying VO as the potential cause of swelling in patients with swollen legs.

  5. Physiology of natriuretic peptides: The volume overload hypothesis revisited

    PubMed Central

    Arjamaa, Olli

    2014-01-01

    The discovery of the natriuretic peptide system in the early 1980s aroused great interest among clinical cardiologists. The heart was not a mechanical pump alone, but also an endocrine organ that had powerful effects on blood circulation. Natriuretic peptides caused both natriuresis and diuresis, and they responded to a volume overload which caused either stretch or pressure on the heart. As a result, the findings led to the conclusion that the human body had a hormone with effects similar to those of a drug which treats high blood pressure. Later, it became evident that the volume contraction was fortified by extrarenal plasma shift. Here, a hypothesis is presented in which the role of natriuretic peptides is to regulate oxygen transport as the volume contraction leads to hemoconcentration with an increased oxygen-carrying capacity. Wall stress, either chemical or mechanical, changes the oxygen gradient of the myocardium and affects the diffusion of oxygen within a myocyte. In support of this hypothesis, hypoxia-response elements have been found in both the atrial natriuretic peptide and the brain natriuretic peptide genes. PMID:24527182

  6. [Echocardiographic study of right ventricular performance by acute and chronic pressure overloadings].

    PubMed

    Tanimoto, M; Iwasaki, T; Yamamoto, T; Makihata, S; Konishiike, A; Mihata, S; Kawakita, S; Yamasaki, K; Yasutomi, N; Kawai, Y

    1984-08-01

    Echocardiographic analysis of right ventricular ejection time (RVET), pre-ejection time (RVPEP), RVPEP/ET and isovolumic relaxation time (RVIRT) was performed in patients with acute or chronic right ventricular pressure overloading. Fifty-five patients undergoing right ventricular cardiac catheterization, were categorized into seven groups; 11 patients with atrial septal defect (ASD) without pulmonary hypertension (PH) (group 1), 12 with ASD with PH (group 2), six with mitral stenosis (MS) without PH (group 3), nine with MS with PH (group 4), seven with primary pulmonary hypertension (PPH) (group 5), seven with acute pulmonary embolism (PE) (group 6), and three patients with convalescence of PE (group 7). Corrected RVIRT (RVIRTc) and RVET (RVETc) were calculated by regression analysis correlating with heart rate in normal subjects. RVIRTc, RVETc, RVPEP and RVPEP/ET in seven groups were significantly correlated with systolic pulmonary artery pressure (SPAP) (r = 0.62, p less than 0.001; r = -0.41, p less than 0.01; r = 0.61, p less than 0.001; r = 0.65, p less than 0.001, respectively), but RVDd did not correlate with SPAP (r = 0.370, p less than 0.05). Comparing acute right ventricular pressure overloading group (group 6) with each of chronic right ventricular pressure overloading groups (groups 2, 4, 5, and 7), RVIRTc and RVDd were significantly increased in the former than the latter, but RVETc, RVPEP and RVPEP/ET were not significantly different in both groups. There was a significant correlation between RVIRTc and RVPEP/ET in chronic pressure overloading, but not in acute pressure overloading. We concluded that early diastolic RV relaxation and systolic performance were both impaired by increased afterload in chronic pressure overloading. In acute pressure overloading, however, early diastolic RV relaxation was more significantly impaired possibly because of acute changes of muscle architectures due to acute right ventricular expansion and anoxia. PMID:6533200

  7. Mechanisms of cardiac hypertrophy in canine volume overload

    NASA Technical Reports Server (NTRS)

    Matsuo, T.; Carabello, B. A.; Nagatomo, Y.; Koide, M.; Hamawaki, M.; Zile, M. R.; McDermott, P. J.

    1998-01-01

    This study tested whether the modest hypertrophy that develops in dogs in response to mitral regurgitation is due to a relatively small change in the rate of protein synthesis or, alternatively, is due to a decreased rate of protein degradation. After 3 mo of severe experimental mitral regurgitation, the left ventricular (LV) mass-to-body weight ratio increased by 23% compared with baseline values. This increase in LV mass occurred with a small, but not statistically significant, increase in the fractional rate of myosin heavy chain (MHC) synthesis (Ks), as measured using continuous infusion with [3H]leucine in dogs at 2 wk, 4 wk, and 3 mo after creation of severe mitral regurgitation. Translational efficiency was unaffected by mitral regurgitation as measured by the distribution of MHC mRNA in polysome gradients. Furthermore, there was no detectable increase in translational capacity as measured by either total RNA content or the rate of ribosome formation. These data indicate that translational mechanisms that accelerate the rate of cardiac protein synthesis are not responsive to the stimulus of mitral regurgitation. Most of the growth after mitral regurgitation was accounted for by a decrease in the fractional rate of protein degradation, calculated by subtracting fractional rates of protein accumulation at each time point from the corresponding Ks values. We conclude that 1) volume overload produced by severe mitral regurgitation does not trigger substantial increases in the rate of protein synthesis and 2) the modest increase in LV mass results primarily from a decrease in the rate of protein degradation.

  8. Volume overload correlates with cardiovascular risk factors in patients with chronic kidney disease.

    PubMed

    Hung, Szu-Chun; Kuo, Ko-Lin; Peng, Ching-Hsiu; Wu, Che-Hsiung; Lien, Yu-Chung; Wang, Yi-Chun; Tarng, Der-Cherng

    2014-03-01

    Volume overload is a predictor of mortality in dialysis patients. However, the fluid status of patients with chronic kidney disease (CKD) but not yet on dialysis has not been accurately characterized. We used the Body Composition Monitor, a multifrequency bioimpedance device, to measure the level of overhydration in CKD patients, focusing on the association between overhydration and cardiovascular disease risk factors. Overhydration was the difference between the amount of extracellular water measured by the Body Composition Monitor and the amount of water predicted under healthy euvolemic conditions. Volume overload was defined as an overhydration value at and above the 90th percentile for the normal population. Of the 338 patients with stages 3-5 CKD, only 48% were euvolemic. Patients with volume overload were found to use significantly more antihypertensive medications and diuretics but had higher systolic blood pressures and an increased arterial stiffness than patients without volume overload. In a multivariate analysis, male sex, diabetes, pre-existing cardiovascular disease, systolic blood pressure, serum albumin, TNF-α, and proteinuria were independently all associated with overhydration. Thus, volume overload is strongly associated with both traditional and novel risk factors for cardiovascular disease. Bioimpedance devices may aid in clinical assessment by helping to identify a high-risk group with volume overload among stages 3-5 CKD patients. PMID:24025647

  9. Acute hypoproteinemic fluid overload: its determinants, distribution, and treatment with concentrated albumin and diuretics.

    PubMed

    Pappova, E; Bachmeier, W; Crevoisier, J L; Kollar, J; Kollar, M; Tobler, P; Zahler, H W; Zaugg, D; Lundsgaard-Hansen, P

    1977-01-01

    We simulated the use of massive volumes of crystalloid fluids as a treatment of acute plasma loss in a standardized experimental model and studied the factors determining the retention or excretion of the resulting acute hypoproteinemic fluid overload, its distribution within the body, and its treatment with concentrated albumin and diuretics. In accordance with the classic Starling concept, the serum protein level, i.e. the serum colloid osmotic pressure, determined the excretion/retention ratio of a given water and sodium load. Of the total fluid retention, fat and muscle each accommodated 25%, whereas the skin, which contributes only 7% to the total body weight, accounted for 37% and increased its volume by roughly one third. Concentrated albumin promoted fluid excretion in direct proportion to the achieved increment of the serum protein level and abolished the edema of fat, muscle and skin. Furosemide was virtually ineffective. The implications of these results for the 'adult respiratory distress syndrome' and disturbed wound healing are discussed and related to the concept of a critical threshold of the serum protein level. PMID:919420

  10. Radionuclide stroke count ratios for assessment of right and left ventricular volume overload in children

    SciTech Connect

    Parrish, M.D.; Graham, T.P. Jr.; Born, M.L.; Jones, J.P.; Boucek, R.J. Jr.; Artman, M.; Partain, C.L.

    1983-01-15

    The ratio of left ventricular to right ventricular stroke counts measured by radionuclide angiography has been used in adults to estimate the severity of left-sided valvular regurgitation. The validation of this technique in children for assessment of right and left ventricular volume overload is reported herein. Radionuclide stroke count ratios in 60 children aged 0.5 to 19 years (mean 11) were determined. Based on their diagnoses, the patients were divided into 3 groups: (1) normal--40 patients with no shunts or valvular regurgitation, (2) left ventricular volume overload--13 patients with mitral or aortic regurgitation, or both, and (3) right ventricular volume overload--7 patients, 2 with severe tricuspid regurgitation, 3 with atrial septal defects, and 2 with total anomalous pulmonary venous drainage. The radionuclide stroke count ratio clearly differentiated these groups (p less than 0.05): normal patients had a stroke count ratio of 1.04 +/- 0.17 (mean +/- 1 standard deviation), the left ventricular volume overload group had a stroke count ratio of 2.43 +/- 0.86, and the right ventricular volume overload group had a stroke count ratio of 0.44 +/- 0.17. In 22 of our 60 patients, radionuclide stroke count ratios were compared with cineangiographic stroke volume ratios, resulting in a correlation coefficient of 0.88. It is concluded that radionuclide ventriculography is an excellent tool for qualitative and quantitative assessment of valvular regurgitation in children.

  11. Acute iron overload and oxidative stress in brain.

    PubMed

    Piloni, Natacha E; Fermandez, Virginia; Videla, Luis A; Puntarulo, Susana

    2013-12-01

    An in vivo model in rat was developed by intraperitoneally administration of Fe-dextran to study oxidative stress triggered by Fe-overload in rat brain. Total Fe levels, as well as the labile iron pool (LIP) concentration, in brain from rats subjected to Fe-overload were markedly increased over control values, 6h after Fe administration. In this in vivo Fe overload model, the ascorbyl (A)/ascorbate (AH(-)) ratio, taken as oxidative stress index, was assessed. The A/AH(-) ratio in brain was significantly higher in Fe-dextran group, in relation to values in control rats. Brain lipid peroxidation indexes, thiobarbituric acid reactive substances (TBARS) generation rate and lipid radical (LR) content detected by Electron Paramagnetic Resonance (EPR), in Fe-dextran supplemented rats were similar to control values. However, values of nuclear factor-kappaB deoxyribonucleic acid (NFκB DNA) binding activity were significantly increased (30%) after 8h of Fe administration, and catalase (CAT) activity was significantly enhanced (62%) 21h after Fe administration. Significant enhancements in Fe content in cortex (2.4 fold), hippocampus (1.6 fold) and striatum (2.9 fold), were found at 6h after Fe administration. CAT activity was significantly increased after 8h of Fe administration in cortex, hippocampus and striatum (1.4 fold, 86, and 47%, respectively). Fe response in the whole brain seems to lead to enhanced NF-κB DNA binding activity, which may contribute to limit oxygen reactive species-dependent damage by effects on the antioxidant enzyme CAT activity. Moreover, data shown here clearly indicate that even though Fe increased in several isolated brain areas, this parameter was more drastically enhanced in striatum than in cortex and hippocampus. However, comparison among the net increase in LR generation rate, in different brain areas, showed enhancements in cortex lipid peroxidation, without changes in striatum and hippocampus LR generation rate after 6h of Fe overload

  12. Fluid Volume Overload and Congestion in Heart Failure: Time to Reconsider Pathophysiology and How Volume Is Assessed.

    PubMed

    Miller, Wayne L

    2016-08-01

    Volume regulation, assessment, and management remain basic issues in patients with heart failure. The discussion presented here is directed at opening a reassessment of the pathophysiology of congestion in congestive heart failure and the methods by which we determine volume overload status. Peer-reviewed historical and contemporary literatures are reviewed. Volume overload and fluid congestion remain primary issues for patients with chronic heart failure. The pathophysiology is complex, and the simple concept of intravascular fluid accumulation is not adequate. The dynamics of interstitial and intravascular fluid compartment interactions and fluid redistribution from venous splanchnic beds to central pulmonary circulation need to be taken into account in strategies of volume management. Clinical bedside evaluations and right heart hemodynamic assessments can alert clinicians of changes in volume status, but only the quantitative measurement of total blood volume can help identify the heterogeneity in plasma volume and red blood cell mass that are features of volume overload in patients with chronic heart failure and help guide individualized, appropriate therapy-not all volume overload is the same. PMID:27436837

  13. Vascular Pedicle Width on Chest Radiograph as a Measure of Volume Overload: Meta-Analysis

    PubMed Central

    Wang, Hao; Shi, Runhua; Mahler, Simon; Gaspard, Joseph; Gorchynski, Julie; D'Etienne, James; Arnold, Thomas

    2011-01-01

    Introduction Vascular pedicle width (VPW), a measurement obtained from a chest radiograph (CR), is thought to be an indicator of circulating blood volume. To date there are only a handful of studies that demonstrate a correlation between high VPW and volume overload, each utilizing different VPW values and CR techniques. Our objective was to determine a mean VPW measurement from erect and supine CRs and to determine whether VPW correlates with volume overload. Methods MEDLINE database, Web of Science, and the Cochrane Central Register of Controlled Trials were searched electronically for relevant articles. References from the original and review publications selected electronically were manually searched for additional relevant articles. Two investigators independently reviewed relevant articles for inclusion criteria and data extraction. Mean VPW measurements from both supine and erect CRs and their correlation with volume overload were calculated. Results Data from 8 studies with a total of 363 subjects were included, resulting in mean VPW measurements of 71 mm (95% confidence interval [CI] 64.9–77.3) and 62 mm (95% CI 49.3–75.1) for supine and erect CRs, respectively. The correlation coefficients for volume overload and VPW were 0.81 (95% CI 0.74–0.86) for both CR techniques and 0.81 (95% CI 0.72–0.87) for supine CR and 0.80 (95% CI 0.69–0.87) for erect CR, respectively. Conclusion There is a clinical and statistical correlation between VPW and volume overload. VPW may be used to evaluate the volume status of a patient regardless of the CR technique used. PMID:22224132

  14. Estrogen attenuates chronic volume overload induced structural and functional remodeling in male rat hearts

    PubMed Central

    Murray, David B.; Voloshenyuk, Tetyana G.; Brower, Gregory L.; Bradley, Jessica M.; Janicki, Joseph S.

    2010-01-01

    We have previously reported gender differences in ventricular remodeling and development of heart failure using the aortocaval fistula model of chronic volume overload in rats. In contrast to males, female rats exhibited no adverse ventricular remodeling and less mortality in response to volume overload. This gender-specific cardioprotection was lost following ovariectomy and was partially restored using estrogen replacement. However, it is not known if estrogen treatment would be as effective in males. The purpose of this study was to evaluate the structural and functional effects of estrogen in male rats subjected to chronic volume overload. Four groups of male rats were studied at 3 days and 8 wk postsurgery as follows: fistula and sham-operated controls, with and without estrogen treatment. Biochemical and histological studies were performed at 3 days postsurgery, with chronic structural and functional effects studied at 8 wk. Measurement of systolic and diastolic pressure-volume relationships was obtained using a blood-perfused isolated heart preparation. Both fistula groups developed significant ventricular hypertrophy after 8 wk of volume overload. Untreated rats with fistula exhibited extensive ventricular dilatation, which was coupled with a loss of systolic function. Estrogen attenuated left ventricular dilatation and maintained function in treated rats. Estrogen treatment was also associated with a reduction in oxidative stress and circulating endothelin-1 levels, as well as prevention of matrix metalloproteinase-2 and -9 activation and breakdown of ventricular collagen in the early stage of remodeling. These data demonstrate that estrogen attenuates ventricular remodeling and disease progression in male rats subjected to chronic volume overload. PMID:19933421

  15. Cardiac interstitial bradykinin and mast cells modulate pattern of LV remodeling in volume overload in rats.

    PubMed

    Wei, Chih-Chang; Lucchesi, Pamela A; Tallaj, Jose; Bradley, Wayne E; Powell, Pamela C; Dell'Italia, Louis J

    2003-08-01

    In the current study, interstitial fluid (ISF), bradykinin (BK), and angiotensin II (ANG II) levels were measured using cardiac microdialysis in conscious, nonsedated rats at baseline and at 48 h and 5 days after each of the following: sham surgery (sham, n = 6), sham + administration of ANG-converting enzyme inhibitor ramipril (R, n = 6), creation of aortocaval fistula (ACF, n = 6), ACF + R (n = 6), and ACF + R + BK2 receptor antagonist (HOE-140) administration (n = 6). At 5 days, both ISF ANG II and BK increased in ACF rats (P < 0.05); however, in ACF + R rats, ISF ANG II did not differ from basal levels and ISF BK increased greater than threefold above baseline at 2 and 5 days (P < 0.05). Five days after ACF, the left ventricular (LV) weight-to-body weight ratio increased 30% (P < 0.05) in ACF but did not differ from sham in ACF + R and ACF + R + HOE-140 rats despite similar systemic arterial pressures across all ACF groups. However, ACF + R + HOE-140 rats had greater postmortem wall thickness-to-diameter ratio and smaller cross-sectional diameter compared with ACF + R rats. There was a significant increase in mast cell density in ACF and ACF + R rats that decreased below sham in ACF + R + HOE-140 rats. These results suggest a potentially important interaction of mast cells and BK in the cardiac interstitium that modulates the pattern of LV remodeling in the acute phase of volume overload. PMID:12663259

  16. Depressed contractile function due to canine mitral regurgitation improves after correction of the volume overload.

    PubMed Central

    Nakano, K; Swindle, M M; Spinale, F; Ishihara, K; Kanazawa, S; Smith, A; Biederman, R W; Clamp, L; Hamada, Y; Zile, M R

    1991-01-01

    It is known that long-standing volume overload on the left ventricle due to mitral regurgitation eventually leads to contractile dysfunction. However, it is unknown whether or not correction of the volume overload can lead to recovery of contractility. In this study we tested the hypothesis that depressed contractile function due to volume overload in mitral regurgitation could return toward normal after mitral valve replacement. Using a canine model of mitral regurgitation which is known to produce contractile dysfunction, we examined contractile function longitudinally in seven dogs at baseline, after 3 mo of mitral regurgitation, 1 mo after mitral valve replacement, and 3 mo after mitral valve replacement. After 3 mo of mitral regurgitation (regurgitant fraction 0.62 +/- 0.04), end-diastolic volume had nearly doubled from 68 +/- 6.8 to 123 +/- 12.1 ml (P less than 0.05). All five indices of contractile function which we examined were depressed. For instance, maximum fiber elastance (EmaxF) obtained by assessment of time-varying elastance decreased from 5.95 +/- 0.71 to 2.25 +/- 0.18 (P less than 0.05). The end-systolic stiffness constant (k) was also depressed from 4.2 +/- 0.4 to 2.1 +/- 0.3. 3 mo after mitral valve replacement all indexes of contractile function had returned to or toward normal (e.g., EmaxF 3.65 +/- 0.21 and k 4.2 +/- 0.3). We conclude that previously depressed contractile function due to volume overload can improve after correction of the overload. PMID:1828252

  17. Adiponectin downregulation is associated with volume overload-induced myocyte dysfunction in rats

    PubMed Central

    Wang, Li-li; Miller, Dori; Wanders, Desiree; Nanayakkara, Gayani; Amin, Rajesh; Judd, Robert; Morrison, Edward E; Zhong, Ju-ming

    2016-01-01

    Aim: Adiponectin has been reported to exert protective effects during pathological ventricular remodeling, but the role of adiponectin in volume overload-induced heart failure remains unclear. In this study we investigated the effect of adiponectin on cardiac myocyte contractile dysfunction following volume overload in rats. Methods: Volume overload was surgically induced in rats by infrarenal aorta-vena cava fistula. The rats were intravenously administered adenoviral adiponectin at 2-, 6- and 9-weeks following fistula. The protein expression of adiponectin, adiponectin receptors (AdipoR1/R2 and T-cadherin) and AMPK activity were measured using Western blot analyses. Isolated ventricular myocytes were prepared at 12 weeks post-fistula to examine the contractile performance of myocytes and intracellular Ca2+ transient. Results: A-V fistula resulted in significant reductions in serum and myocardial adiponectin levels, myocardial adiponectin receptor (AdipoR1/R2 and T-cadherin) levels, as well as myocardial AMPK activity. Consistent with these changes, the isolated myocytes exhibited significant depression in cell shortening and intracellular Ca2+ transient. Administration of adenoviral adiponectin significantly increased serum adiponectin levels and prevented myocyte contractile dysfunction in fistula rats. Furthermore, pretreatment of isolated myocytes with recombinant adiponectin (2.5 μg/mL) significantly improved their contractile performance in fistula rats, but had no effects in control or adenoviral adiponectin-administered rats. Conclusion: These results demonstrate a positive correlation between adiponectin downregulation and volume overload-induced ventricular remodeling. Adiponectin plays a protective role in volume overload-induced heart failure. PMID:26616727

  18. Acute iron overload leads to hypothalamic-pituitary-gonadal axis abnormalities in female rats.

    PubMed

    Rossi, Emilly M; Marques, Vinicius B; Nunes, Dieli de O; Carneiro, Maria T W D; Podratz, Priscila L; Merlo, Eduardo; dos Santos, Leonardo; Graceli, Jones B

    2016-01-01

    Iron plays a critical role in a mammal's physiological processes. However, iron tissue deposits have been shown to act as endocrine disrupters. Studies that evaluate the effect of acute iron overload on hypothalamic-pituitary-gonadal (HPG) axis health are particularly sparse. This study demonstrates that acute iron overload leads to HPG axis abnormalities, including iron accumulation and impairment in reproductive tract morphology. Female rats were treated with iron-dextran (Fe rats) to assess their HPG morphophysiology. The increasing serum iron levels due to iron-dextran treatment were positively correlated with higher iron accumulation in the HPG axis and uterus of Fe rats than in control rats. An increase in the production of superoxide anions was observed in the pituitary, uterus and ovary of Fe rats. Morphophysiological reproductive tract abnormalities, such as abnormal ovarian follicular development and the reduction of serum estrogen levels, were observed in Fe rats. In addition, a significant negative correlation was obtained between ovary superoxide anion and serum estrogen levels. Together, these data provide in vivo evidence that acute iron overload is toxic for the HPG axis, a finding that may be associated with the subsequent development of the risk of reproductive dysfunction. PMID:26536400

  19. Reversed association between aldosterone and mortality in hemodialysis patients: Role of volume overload.

    PubMed

    Hung, Szu-Chun; Tarng, Der-Cherng

    2016-07-01

    The role of aldosterone has expanded from its genomic effects that involve renal sodium transport to nongenomic effects such as cardiac and renal fibrosis. Elevated aldosterone levels are associated with increased mortality in the general population. However, the association is reversed in patients with end-stage renal disease on maintenance hemodialysis. We have shown that the inverse association between aldosterone and mortality in hemodialysis patients is due to the confounding effect of volume overload. Volume overload, which is prevalent in patients with chronic kidney disease, is associated with both lower aldosterone concentrations and higher mortality. Our findings support salt and water restriction and treatment of hyperaldosteronemia in hemodialysis patients who have achieved strict volume control. PMID:26826322

  20. Mechanical support of the pressure overloaded right ventricle: an acute feasibility study comparing low and high flow support.

    PubMed

    Verbelen, Tom; Verhoeven, Jelle; Goda, Motohiko; Burkhoff, Daniel; Delcroix, Marion; Rega, Filip; Meyns, Bart

    2015-08-15

    The objectives of this study were to assess the feasibility of low flow right ventricular support and to describe the hemodynamic effects of low versus high flow support in an animal model of acute right ventricular pressure overload. A Synergy Pocket Micro-pump (HeartWare International, Framingham, MA) was implanted in seven sheep. Blood was withdrawn from the right atrium to the pulmonary artery. Hemodynamics and pressure-volume loops were recorded in baseline conditions, after banding the pulmonary artery, and after ligating the right coronary artery in these banded sheep. End-organ perfusion (reflected by total cardiac output and arterial blood pressure) improved in all conditions. Intrinsic right ventricular contractility was not significantly impacted by support. Diastolic unloading of the pressure overloaded right ventricle (reflected by decreases in central venous pressure, end-diastolic pressure and volume, and ventricular capacitance) was successful, but with a concomitant and flow-dependent increase of the systolic afterload. This unloading diminished with right ventricular ischemia. Right ventricular mechanical support improves arterial blood pressure and cardiac output. It provides diastolic unloading of the right ventricle, but with a concomitant and right ventricular assist device flow-dependent increase of systolic afterload. These effects are most distinct in the pressure overloaded right ventricle without profound ischemic damage. We advocate the low flow strategy, which is potentially beneficial for the afterload sensitive right ventricle and has the advantage of avoiding excessive increases in pulmonary artery pressure when pulmonary hypertension exists. This might protect against the development of pulmonary edema and hemorrhage. PMID:26071544

  1. TNF-α inhibition attenuates adverse myocardial remodeling in a rat model of volume overload

    PubMed Central

    Jobe, Lynetta J.; Meléndez, Giselle C.; Levick, Scott P.; Du, Yan; Brower, Gregory L.

    2009-01-01

    Tumor necrosis factor (TNF)-α is a proinflammatory cytokine that has been implicated in the pathogenesis of heart failure. In contrast, we have recently shown that myocardial levels of TNF-α are acutely elevated in the aortocaval (AV) fistula model of heart failure. Based on these observations, we hypothesized that progression of adverse myocardial remodeling secondary to volume overload would be prevented by inhibition of TNF-α with etanercept. Furthermore, a principal objective of this study was to elucidate the effect of TNF-α inhibition during different phases of the myocardial remodeling process. Eight-week-old male Sprague-Dawley rats were randomly divided into the following three groups: sham-operated controls, untreated AV fistulas, and etanercept-treated AV fistulas. Each group was further subdivided to study three different time points consisting of 3 days, 3 wk, and 8 wk postfistula. Etanercept was administered subcutaneously at 1 mg/kg body wt. Etanercept prevented collagen degradation at 3 days and significantly attenuated the decrease in collagen at 8 wk postfistula. Although TNF-α antagonism did not prevent the initial ventricular dilatation at 3 wk postfistula, etanercept was effective at significantly attenuating the subsequent ventricular hypertrophy, dilatation, and increased compliance at 8 wk postfistula. These positive adaptations achieved with etanercept administration translated into significant functional improvements. At a cellular level, etanercept also markedly attenuated increases in cardiomyocyte length, width, and area at 8 wk postfistula. These observations demonstrate that TNF-α has a pivotal role in adverse myocardial remodeling and that treatment with etanercept can attenuate the progression to heart failure. PMID:19666842

  2. Temporal Evaluation of Cardiac Myocyte Hypertrophy and Hyperplasia in Male Rats Secondary to Chronic Volume Overload

    PubMed Central

    Du, Yan; Plante, Eric; Janicki, Joseph S.; Brower, Gregory L.

    2010-01-01

    The temporal myocardial remodeling induced by chronic ventricular volume overload in male rats was examined. Specifically, left ventricular (LV) cardiomyocyte length and width, sarcomere length, and number of nuclei were measured in male rats (n = 8 to 17) at 1, 3, 5, 7, 21, 35, and 56 days after creation of an infrarenal aortocaval fistula. In contrast to previously published reports of progressive increases in cardiomyocyte length and cross-sectional area at 5 days post-fistula and beyond in female hearts, cardiomyocyte length and width did not increase significantly in males during the first 35 days of volume overload. Furthermore, a significant decrease in cardiomyocyte length relative to age-matched controls, together with a reduced number of sarcomeres per cell, was noted in male hearts at 5 days post-fistula. There was a concurrent increase in the percentage of mononucleated cardiomyocytes from 11.6% to 18% at 5 days post-fistula. These initial differences could not be attributed to cardiomyocyte proliferation, and treatment with a microtubule stabilizing agent prevented them from occurring. The subsequent significant increase in LV weight without corresponding increases in cardiomyocyte dimensions is indicative of hyperplasia. Thus, these findings indicate hyperplasia resulting from cytokinesis of cardiomyocytes is a key mechanism, independent of hypertrophy, that contributes to the significant increase in LV mass in male hearts subjected to chronic volume overload. PMID:20651227

  3. Effects of pressure- or volume-overload hypertrophy on passive stiffness in isolated adult cardiac muscle cells

    NASA Technical Reports Server (NTRS)

    Kato, S.; Koide, M.; Cooper, G. 4th; Zile, M. R.

    1996-01-01

    It has been hypothesized that the changes in myocardial stiffness induced by chronic hemodynamic overloading are dependent on changes in the passive stiffness of the cardiac muscle cell (cardiocyte). However, no previous studies have examined the passive constitutive properties of cardiocytes isolated from animals with myocardial hypertrophy. Accordingly, changes in relative passive stiffness of cardiocytes isolated from animals with chronic pressure- or volume-overload hypertrophy were determined by examining the effects of anisosmotic stress on cardiocyte size. Anisosmotic stress was produced by altering superfusate osmolarity. Hypertrophied cardiocytes were enzymatically isolated from 16 adult cats with right ventricular (RV) pressure-overload hypertrophy induced by pulmonary artery banding (PAB) and from 6 adult cats with RV volume-overload hypertrophy induced by creating an atrial septal defect (ASD). Left ventricular (LV) cardiocytes from each cat served as nonhypertrophied, normally loaded, same-animal controls. Superfusate osmolarity was decreased from 305 +/- 3 to 135 +/- 5 mosM and increased to 645 +/- 4 mosM. During anisosmotic stress, there were no significant differences between hypertrophied RV and normal LV cardiocytes in pressure overload PAB cats with respect to percent change in cardiocyte area (47 +/- 2% in RV vs. 48 +/- 2% in LV), diameter (46 +/- 3% in RV vs. 48 +/- 2% in LV), or length (2.4 +/- 0.2% in RV vs. 2.0 +/- 0.3% in LV), or sarcomere length (1.5 +/- 0.1% in RV vs. 1.3 +/- 0.3% in LV). Likewise, there were no significant differences in cardiocyte strain between hypertrophied RV and normal LV cardiocytes from ASD cats. In conclusion, chronic pressure-overload hypertrophy and chronic volume-overload hypertrophy did not alter the cardiocyte response to anisosmotic stress. Thus chronic overload hypertrophy did not alter relative passive cardiocyte stiffness.

  4. Vascular refilling is independent of volume overload in hemodialysis with moderate ultrafiltration requirements.

    PubMed

    Kron, Susanne; Schneditz, Daniel; Leimbach, Til; Aign, Sabine; Kron, Joachim

    2016-07-01

    Introduction Blood volume changes and vascular refilling during hemodialysis (HD) and ultrafiltration (UF) have been assumed to depend on volume overload (Vo ). It was the aim to study the magnitude of vascular refilling in stable HD patients with moderate volume expansion in everyday dialysis using novel technical approaches. Methods Patients were studied during routine dialysis and UF based on clinical dry weight assessment. Pre-dialysis Vo was independently measured by bioimpedance spectroscopy. Vascular refilling volume (Vref ) was calculated as: Vref  = Vuf  - ΔV, where ΔV is the absolute blood volume change determined by on-line dialysate dilution using a commercial on-line hemodiafiltration machine incorporating a relative blood volume monitor, and where Vuf is the prescribed UF volume. Findings Thirty patients (dry weight: 81.0 ± 17.8 kg) were studied. Pre-dialysis Vo was 2.46 ± 1.45 L. Vuf was 2.27 ± 0.71 L, specific UF rate was 6.45 ± 2.43 mL/kg/h, and since ΔV was 0.66 ± 0.31 L, Vref was determined as 1.61 ± 0.58 L, corresponding to a constant refilling fraction (Fref ) of 70.6 ± 10.6%. Vref strongly correlated with Vuf (r(2)  = 0.82) but was independent of Vo and other volumes. Fref was also independent of Vo and other volumes normalized for various measures of body size. Discussion While vascular refilling and Fref is independent of Vo in treatments with moderate UF requirements, intravascular volume depletion increases with increasing UF requirements. The relationship between blood volume and Vo needs to be more closely examined in further studies to optimize volume control in everyday dialysis. PMID:27061224

  5. [Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO)].

    PubMed

    Okazaki, Hitoshi

    2013-05-01

    In recent years, much attention has been paid to respiratory complications of transfusion. Transfusion related acute lung injury (TRALI) is defined as an acute lung injury that is temporally associated with blood transfusion. TRALI is one of the leading causes of mortality. Although the etiology of TRALI is not fully understood, one of its main causes is thought to be anti-leukocyte antibodies, such as HLA antibody or HNA antibody. A precautionary male-predominant plasma strategy has been implemented in many developed countries, which has resulted in considerable achievements in reducing the incidence of TRALI. Meanwhile, transfusion-associated circulatory overload (TACO) has emerged as a major differential diagnosis of TRALI. TACO is a well-known complication of transfusion, which has been considered not as a side effect of transfusion but a result of erroneous medical practice. It has long been an under-reported complication of transfusion and has not been investigated scientifically. Recent data on transfusion mortality from the Food and Drug Administration revealed that TACO was the second highest cause of death in the United States. Our data also suggested a steep increase in the reported cases of TACO in Japan. Precautionary measures should also be implemented for this emerging complication. PMID:23947178

  6. Dietary salt restriction activates mineralocorticoid receptor signaling in volume-overloaded heart failure.

    PubMed

    Mori, Tatsuhiko; Kurumazuka, Daisuke; Matsumoto, Chika; Shirakawa, Hisashi; Kimura, Sayaka; Kitada, Kento; Kobayashi, Kana; Matsuda, Hirohisa; Hayashi, Tetsuya; Kitaura, Yasushi; Matsumura, Yasuo

    2009-11-25

    Whether a high plasma aldosterone concentration induced by strict salt restriction promotes cardiac remodeling remains controversial. Male Sprague-Dawley rats at 10weeks of age were given normal salt (NS) (1.5% NaCl) or low salt (LS) (0.05% NaCl) diets. Each animal underwent aortocaval fistula creation for volume-overloaded heart failure or sham surgery. All rats with a fistula received either vehicle or a non-hypotensive dose of spironolactone (200mg/kg/day) by gavage. Two weeks later, the LS diet significantly increased the plasma aldosterone level in the sham-operated and fistula-created rats (2677+/-662pg/ml and 2406+/-422pg/ml) compared with that in rats given the NS diet (518+/-18pg/ml and 362+/-45pg/ml, respectively). In sham-operated rats, the difference in plasma aldosterone level did not affect the extent of myocardial fibrosis (1.8+/-0.1% with LS diet vs. 1.5+/-0.3% with NS diet). However, the increase in myocardial fibrosis in fistula-created rats was more prominent with the LS diet than with the NS diet (4.7+/-0.3% vs. 3.4+/-0.1%). In addition, the fistula-created rats on the LS diet expressed significantly increased oxidative stress and transforming growth factor-beta compared with those on the NS diets (P<0.05). These increases in the fistula-created rats on the LS diet were significantly suppressed by the non-hypotensive dose of spironolactone (P<0.05). These results suggest that increased plasma aldosterone level with strict salt restriction activated the mineralocorticoid receptor signaling in volume-overloaded condition, resulting in increased myocardial fibrosis. PMID:19766104

  7. Metabolic characterization of volume overload heart failure due to aorto-caval fistula in rats.

    PubMed

    Melenovsky, Vojtech; Benes, Jan; Skaroupkova, Petra; Sedmera, David; Strnad, Hynek; Kolar, Michal; Vlcek, Cestmir; Petrak, Jiri; Benes, Jiri; Papousek, Frantisek; Oliyarnyk, Olena; Kazdova, Ludmila; Cervenka, Ludek

    2011-08-01

    Metabolic interactions between adipose tissue and the heart may play an active role in progression of heart failure (HF). The aim of the study was to examine changes in myocardial and adipose tissue metabolism and gene expression in a rat HF model induced by chronic volume overload. HF was induced by volume overload from aorto-caval fistula (ACF) in 3-month-old male Wistar rats and animals were studied in the phase of decompensated HF (22nd week). HF rats showed marked eccentric cardiac hypertrophy, pulmonary congestion, increased LV end-diastolic pressure, and intraabdominal fat depletion. HF rats had preserved glucose tolerance, but increased circulating free fatty acids (FFA) and attenuated insulin response during oral glucose challenge. Isolated organ studies showed preserved responsiveness of adipose tissue lipolysis and lipogenesis to epinephrine and insulin in ACF. The heart of HF animals had markedly reduced triglyceride content (almost to half of controls), attenuated anti-oxidative reserve (GSH/GSSG), upregulated HF markers (ANP, periostin, thrombospondin-4), specific signaling pathways (Wnt, TGF-β), and downregulated enzymes of mitochondrial fatty acid oxidation, citric acid cycle, and respiratory chain. Adipose tissue transcription profiling showed upregulated receptor for gastric inhibitory polypeptide. In conclusion, ACF-induced HF model displays several deregulations of systemic metabolism. Despite elevation of systemic FFAs, myocardial triglycerides are low and insulin levels are attenuated, arguing against a role of lipotoxicity or insulin resistance in this model. Attenuated postprandial insulin response and relative lack of its antilipolytic effects may facilitate intraabdominal fat depletion observed in ACF-HF animals. PMID:21465236

  8. Effects of acute lipid overload on skeletal muscle insulin resistance, metabolic flexibility, and mitochondrial performance.

    PubMed

    Dubé, John J; Coen, Paul M; DiStefano, Giovanna; Chacon, Alexander C; Helbling, Nicole L; Desimone, Marisa E; Stafanovic-Racic, Maja; Hames, Kazanna C; Despines, Alex A; Toledo, Frederico G S; Goodpaster, Bret H

    2014-12-15

    We hypothesized that acute lipid-induced insulin resistance would be attenuated in high-oxidative muscle of lean trained (LT) endurance athletes due to their enhanced metabolic flexibility and mitochondrial capacity. Lean sedentary (LS), obese sedentary (OS), and LT participants completed two hyperinsulinemic euglycemic clamp studies with and without (glycerol control) the coinfusion of Intralipid. Metabolic flexibility was measured by indirect calorimetry as the oxidation of fatty acids and glucose during fasted and insulin-stimulated conditions, the latter with and without lipid oversupply. Muscle biopsies were obtained for mitochondrial and insulin-signaling studies. During hyperinsulinemia without lipid, glucose infusion rate (GIR) was lowest in OS due to lower rates of nonoxidative glucose disposal (NOGD), whereas state 4 respiration was increased in all groups. Lipid infusion reduced GIR similarly in all subjects and reduced state 4 respiration. However, in LT subjects, fat oxidation was higher with lipid oversupply, and although glucose oxidation was reduced, NOGD was better preserved compared with LS and OS subjects. Mitochondrial performance was positively associated with better NOGD and insulin sensitivity in both conditions. We conclude that enhanced mitochondrial performance with exercise is related to better metabolic flexibility and insulin sensitivity in response to lipid overload. PMID:25352435

  9. Increased risk of volume overload with plasma compared with four‐factor prothrombin complex concentrate for urgent vitamin K antagonist reversal

    PubMed Central

    Refaai, Majed A.; Goldstein, Joshua N.; Lee, Martin L.; Durn, Billie L.; Milling, Truman J.; Sarode, Ravi

    2015-01-01

    BACKGROUND Plasma is commonly used for vitamin K antagonist (VKA) reversal, but observational studies suggest that it is associated with transfusion‐related adverse reactions (e.g., volume overload). However, this issue has not previously been addressed in a randomized controlled trial (RCT). STUDY DESIGN AND METHODS Factors associated with volume overload were examined using data from two Phase IIIb RCTs comparing plasma with four‐factor prothrombin complex concentrate (4F‐PCC, Beriplex/Kcentra, CSL Behring) for urgent VKA reversal. VKA‐treated patients with major bleeding (NCT00708435) or requiring an urgent surgical or invasive procedure (NCT00803101) were randomly assigned (1:1) to receive either plasma or 4F‐PCC, concomitant with vitamin K. Adverse events (AEs) and serious AEs were prospectively captured up to Day 10 and 45, respectively. Volume overload predictors were evaluated on a univariate and multivariate basis. RESULTS A total of 388 patients (4F‐PCC, n = 191; plasma, n = 197) were enrolled. Volume overload occurred in 34 (9%) patients (4F‐PCC, n = 9; plasma, n = 25). In univariate analyses, use of plasma (vs. 4F‐PCC), use of nonstudy plasma and/or platelets, race, history of congestive heart failure (CHF), and history of renal disease were associated with volume overload. In multivariate analyses, use of plasma (vs. 4F‐PCC), history of CHF, and history of renal disease were independent volume overload predictors. In an additional analysis restricted to volume overload events recorded up to Day 7, only use of plasma (vs. 4F‐PCC) was an independent volume overload predictor. CONCLUSIONS After adjusting for other potential risk factors, plasma use was independently associated with a greater risk of volume overload than 4F‐PCC in patients requiring urgent VKA reversal. PMID:26135740

  10. The Akt-mTOR axis is a pivotal regulator of eccentric hypertrophy during volume overload.

    PubMed

    Ikeda, Masataka; Ide, Tomomi; Fujino, Takeo; Matsuo, Yuka; Arai, Shinobu; Saku, Keita; Kakino, Takamori; Oga, Yasuhiro; Nishizaki, Akiko; Sunagawa, Kenji

    2015-01-01

    The heart has two major modalities of hypertrophy in response to hemodynamic loads: concentric and eccentric hypertrophy caused by pressure and volume overload (VO), respectively. However, the molecular mechanism of eccentric hypertrophy remains poorly understood. Here we demonstrate that the Akt-mammalian target of rapamycin (mTOR) axis is a pivotal regulator of eccentric hypertrophy during VO. While mTOR in the heart was activated in a left ventricular end-diastolic pressure (LVEDP)-dependent manner, mTOR inhibition suppressed eccentric hypertrophy and induced cardiac atrophy even under VO. Notably, Akt was ubiquitinated and phosphorylated in response to VO, and blocking the recruitment of Akt to the membrane completely abolished mTOR activation. Various growth factors were upregulated during VO, suggesting that these might be involved in Akt-mTOR activation. Furthermore, the rate of eccentric hypertrophy progression was proportional to mTOR activity, which allowed accurate estimation of eccentric hypertrophy by time-integration of mTOR activity. These results suggested that the Akt-mTOR axis plays a pivotal role in eccentric hypertrophy, and mTOR activity quantitatively determines the rate of eccentric hypertrophy progression. As eccentric hypertrophy is an inherent system of the heart for regulating cardiac output and LVEDP, our findings provide a new mechanistic insight into the adaptive mechanism of the heart. PMID:26515499

  11. The Akt-mTOR axis is a pivotal regulator of eccentric hypertrophy during volume overload

    PubMed Central

    Ikeda, Masataka; Ide, Tomomi; Fujino, Takeo; Matsuo, Yuka; Arai, Shinobu; Saku, Keita; Kakino, Takamori; Oga, Yasuhiro; Nishizaki, Akiko; Sunagawa, Kenji

    2015-01-01

    The heart has two major modalities of hypertrophy in response to hemodynamic loads: concentric and eccentric hypertrophy caused by pressure and volume overload (VO), respectively. However, the molecular mechanism of eccentric hypertrophy remains poorly understood. Here we demonstrate that the Akt-mammalian target of rapamycin (mTOR) axis is a pivotal regulator of eccentric hypertrophy during VO. While mTOR in the heart was activated in a left ventricular end-diastolic pressure (LVEDP)-dependent manner, mTOR inhibition suppressed eccentric hypertrophy and induced cardiac atrophy even under VO. Notably, Akt was ubiquitinated and phosphorylated in response to VO, and blocking the recruitment of Akt to the membrane completely abolished mTOR activation. Various growth factors were upregulated during VO, suggesting that these might be involved in Akt-mTOR activation. Furthermore, the rate of eccentric hypertrophy progression was proportional to mTOR activity, which allowed accurate estimation of eccentric hypertrophy by time-integration of mTOR activity. These results suggested that the Akt-mTOR axis plays a pivotal role in eccentric hypertrophy, and mTOR activity quantitatively determines the rate of eccentric hypertrophy progression. As eccentric hypertrophy is an inherent system of the heart for regulating cardiac output and LVEDP, our findings provide a new mechanistic insight into the adaptive mechanism of the heart. PMID:26515499

  12. [Echocardiographic triangular pattern of the mitral valve during acute pressure overload of the left ventricle: an experimental study].

    PubMed

    Tanimoto, M; Yamamoto, T; Kimura, S; Komasa, N; Makihata, S; Yasutomi, N; Saito, Y; Kawai, Y; Iwasaki, T

    1982-03-01

    The changes of mitral valve echo and hemodynamic data [isovolumic relaxation time (IRT)/square root R-R, time constant T, peak positive dP/dt/P, left ventricular enddiastolic pressure (LVEDP) and left ventricular systolic pressure (LVSP] during acute pressure overload produced by aortic root obstruction were analyzed in 13 mongrel dogs under sodium pentbarbital anesthesia (25 mg/kg). IRT/square root R-R, time constant T, positive dP/dt and LVSP were expressed as percent changes to the value (=100%) of pre-pressure overload, LVEDP was expressed by an absolute value as mmHg. In 7 of 13 dogs, an abnormal diastolic monophasic triangular pattern of the mitral valve was observed during acute pressure overload of the left ventricle, and values of five hemodynamic data were compared between cases with or without the triangular pattern. The values of IRT/square root R-R, time constant T, positive dP/dt/P, LVSP amd LVEDP in cases with the triangular pattern became from 200 to 500% (275 +/- 100%), from 175 to 267% (220 +/- 50%), from 55 to 112% (81 +/- 21%), from 129 to 200% (59 +/- 21%) and from 7 to 33 mmHg (16 +/- 9 mmHg), respectively. The values of IRT/square root R-R, time constant T, positive dP/dt/P, LVSP and LVEDP in cases with the non-triangular pattern became from 116 to 155% (133 +/- 17%), from 116 to 154% (136 +/- 16%), from 111 to 186% (62 +/- 34%) and from 9 to 20 mmHg (9 +/- 6 mmHg), respectively. Thus, the values of IRT/square root R-R and time constant T were significantly different between the two groups. The possible explanation for the triangular pattern of the mitral valve seems to be due to impaired active relaxation system of the left ventricle resulting in a markedly delayed opening of the mitral valve. We conclude that early diastolic isovolumic relaxation of the left ventricle is impaired by acute pressure overload, and the echocardiographic diastolic monophasic triangular pattern of the mitral valve reflects this impairment. PMID:7119493

  13. Effect of Progressive Volume-Based Overload During Plyometric Training on Explosive and Endurance Performance in Young Soccer Players.

    PubMed

    Ramírez-Campillo, Rodrigo; Henríquez-Olguín, Carlos; Burgos, Carlos; Andrade, David C; Zapata, Daniel; Martínez, Cristian; Álvarez, Cristian; Baez, Eduardo I; Castro-Sepúlveda, Mauricio; Peñailillo, Luis; Izquierdo, Mikel

    2015-07-01

    The purpose of the study was to compare the effects of progressive volume-based overload with constant volume-based overload on muscle explosive and endurance performance adaptations during a biweekly short-term (i.e., 6 weeks) plyometric training intervention in young soccer players. Three groups of young soccer players (age 13.0 ± 2.3 years) were divided into: control (CG; n = 8) and plyometric training with (PPT; n = 8) and without (NPPT; n = 8) a progressive increase in volume (i.e., 16 jumps per leg per week, with an initial volume of 80 jumps per leg each session). Bilateral and unilateral horizontal and vertical countermovement jump with arms (CMJA), 20-cm drop jump reactive strength index (RSI20), maximal kicking velocity (MKV), 10-m sprint, change of direction speed (CODS), and Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1) were measured. Although both experimental groups significantly increased CMJA, RSI20, CODS, and endurance performance, only PPT showed a significant improvement in MKV and 10-m sprint time. In addition, only PPT showed a significantly higher performance improvement in jumping, MKV, and Yo-Yo IR1 compared with CG. Also, PPT showed higher meaningful improvement compared with NPPT in all (except 1) jump performance measures. Furthermore, although PPT involved a higher total volume compared with NPPT, training efficiency (i.e., percentage change in performance/total jump volume) was similar between groups. Our results show that PPT and NPPT ensured significant improvement in muscle explosive and endurance performance measures. However, a progressive increase in plyometric training volume seems more advantageous to induce soccer-specific performance improvements. PMID:25559905

  14. Blocking Cyclic Adenosine Diphosphate Ribose-mediated Calcium Overload Attenuates Sepsis-induced Acute Lung Injury in Rats

    PubMed Central

    Peng, Qian-Yi; Zou, Yu; Zhang, Li-Na; Ai, Mei-Lin; Liu, Wei; Ai, Yu-Hang

    2016-01-01

    Background: Acute lung injury (ALI) is a common complication of sepsis that is associated with high mortality. Intracellular Ca2+ overload plays an important role in the pathophysiology of sepsis-induced ALI, and cyclic adenosine diphosphate ribose (cADPR) is an important regulator of intracellular Ca2+ mobilization. The cluster of differentiation 38 (CD38)/cADPR pathway has been found to play roles in multiple inflammatory processes but its role in sepsis-induced ALI is still unknown. This study aimed to investigate whether the CD38/cADPR signaling pathway is activated in sepsis-induced ALI and whether blocking cADPR-mediated calcium overload attenuates ALI. Methods: Septic rat models were established by cecal ligation and puncture (CLP). Rats were divided into the sham group, the CLP group, and the CLP+ 8-bromo-cyclic adenosine diphosphate ribose (8-Br-cADPR) group. Nicotinamide adenine dinucleotide (NAD+), cADPR, CD38, and intracellular Ca2+ levels in the lung tissues were measured at 6, 12, 24, and 48 h after CLP surgery. Lung histologic injury, tumor necrosis factor (TNF)-α, malondialdehyde (MDA) levels, and superoxide dismutase (SOD) activities were measured. Results: NAD+, cADPR, CD38, and intracellular Ca2+ levels in the lungs of septic rats increased significantly at 24 h after CLP surgery. Treatment with 8-Br-cADPR, a specific inhibitor of cADPR, significantly reduced intracellular Ca2+ levels (P = 0.007), attenuated lung histological injury (P = 0.023), reduced TNF-α and MDA levels (P < 0.001 and P = 0.002, respectively) and recovered SOD activity (P = 0.031) in the lungs of septic rats. Conclusions: The CD38/cADPR pathway is activated in the lungs of septic rats, and blocking cADPR-mediated calcium overload with 8-Br-cADPR protects against sepsis-induced ALI. PMID:27411462

  15. Post-partum sequential occurrence of two diverse transfusion reactions (transfusion associated circulatory overload and transfusion related acute lung injury).

    PubMed

    Haldar, Rudrashish; Samanta, Sukhen

    2013-10-01

    Transfusion associated circulatory overload (TACO) and transfusion related acute lung injury (TRALI) are two dissimilar pathological conditions associated with transfusion of blood products where the time course of the events and clinical presentation overlap leading to uncertainty in establishing the diagnosis and initiating the treatment, which otherwise differs. We encountered a case where a patient of post-partum hemorrhage developed TACO in the immediate post-operative period due to aggressive resuscitative attempts with blood products. The patient's condition was appropriately diagnosed and was managed according to the clinical scenario, and the condition abated. Subsequently, on the third post-operative day the patient again required blood product transfusions following which the patient developed TRALI, the diagnosis of which was also established and adequate treatment strategy was undertaken. PMID:24339663

  16. Basic transformer-life characteristics. Volume 1: Overload characteristics and life-test evaluation

    NASA Astrophysics Data System (ADS)

    Kaufmann, G. H.

    1982-06-01

    The results of experimental studies related to transformer survivability are described. It deals with the behavior of typical power transformer insulation systems during short-time exposure to elevated temperatures, and it provides some insight into failure mechanisms associated with gas bubble evolution within the insulation structure. Another important phase of the program involved the development and exploratory evaluation of a functional test program which may be used for determining the life expectancy characteristics of power transformers. Still another investigation resulted in the development and evaluation of an overload test procedure for power transformers. A feasibility study on a new type of thermal sensor for possible use as a winding hot spot sensor yielded promising results. The data presented is expected to be of help in developing improved transformer operating practices and in permitting an assessment of failure risks associated with particular service conditions.

  17. Continuous renal replacement therapy versus furosemide for management of kidney impairment in heart transplant recipients with volume overload

    PubMed Central

    Mirhosseini, Seyed Mohsen; Fakhri, Mohammad; Asadollahi, Shadi; Ahmadi, Zargham Hossein; Rashid Farokhi, Farin; Boloursaz, Mohammad Reza; Masjedi, Mohammad Reza

    2013-01-01

    OBJECTIVES It is unknown whether continuous renal replacement therapy or furosemide therapy is superior in heart transplant recipients who are in postoperative kidney insufficiency and volume overload. This prospective non-randomized, controlled trial investigated the efficacy of the two methods after transplantation. METHODS We assigned heart transplant recipients 18 years of age or older who were oliguric (urine output < 400 ml/day); had volume overload and estimated glomerular filtration rate <60 ml/min/1.73 m2 of body surface area calculated with the use of the Modification of Diet in Renal Disease equation, to designed initiation of intervention. We followed 30 patients for up to 30 days. The primary outcome was estimated glomerular filtration rate status after intervention. RESULTS Between January 2010 and April 2012, a total of 30 adults (mean age: 37 years; 18 men and 12 women) were assessed for entry in this trial. Continuous renal replacement therapy, when compared with furosemide, was associated with a significant increase in estimated glomerular filtration rate of patients after intervention 61 ± 4.5 vs 55 ± 8.5l ml/min/1.73 m2 (P = 0.02). Moreover, the mean glomerular filtration rate at discharge time for the continuous renal replacement therapy group was 72 ± 7.3 and 58 ± 7.4 ml/min/1.73 m2 for the furosemide group (P < 0.001). During the follow-up period, 6 of 15 patients in the continuous renal replacement therapy group (40%) and 4 of 15 in the furosemide group (26.6%) died (P = 0.43). CONCLUSIONS In this study, continuous renal replacement therapy in heart transplant recipients with reduced kidney function was associated with an improvement in estimated glomerular filtration rate status in comparison with furosemide. PMID:23223674

  18. Changes in Myocardial Composition and Conduction Properties in Rat Heart Failure Model Induced by Chronic Volume Overload.

    PubMed

    Sedmera, David; Neckar, Jan; Benes, Jiri; Pospisilova, Jana; Petrak, Jiri; Sedlacek, Kamil; Melenovsky, Vojtech

    2016-01-01

    Volume overload leads to development of eccentric cardiac hypertrophy and heart failure. In our previous report, we have shown myocyte hypertrophy with no fibrosis and decrease in gap junctional coupling via connexin43 in a rat model of aorto-caval fistula at 21 weeks. Here we set to analyze the electrophysiological and protein expression changes in the left ventricle and correlate them with phenotypic severity based upon ventricles to body weight ratio. ECG analysis showed increased amplitude and duration of the P wave, prolongation of PR and QRS interval, ST segment elevation and decreased T wave amplitude in the fistula group. Optical mapping showed a prolongation of action potential duration in the hypertrophied hearts. Minimal conduction velocity (CV) showed a bell-shaped curve, with a significant increase in the mild cases and there was a negative correlation of both minimal and maximal CV with heart to body weight ratio. Since the CV is influenced by gap junctional coupling as well as the autonomic nervous system, we measured the amounts of tyrosine hydroxylase (TH) and choline acetyl transferase (ChAT) as a proxy for sympathetic and parasympathetic innervation, respectively. At the protein level, we confirmed a significant decrease in total and phosphorylated connexin43 that was proportional to the level of hypertrophy, and similarly decreased levels of TH and ChAT. Even at a single time-point, severity of morphological phenotype correlates with progression of molecular and electrophysiological changes, with the most hypertrophied hearts showing the most severe changes that might be related to arrhythmogenesis. PMID:27610087

  19. Changes in Myocardial Composition and Conduction Properties in Rat Heart Failure Model Induced by Chronic Volume Overload

    PubMed Central

    Sedmera, David; Neckar, Jan; Benes, Jiri; Pospisilova, Jana; Petrak, Jiri; Sedlacek, Kamil; Melenovsky, Vojtech

    2016-01-01

    Volume overload leads to development of eccentric cardiac hypertrophy and heart failure. In our previous report, we have shown myocyte hypertrophy with no fibrosis and decrease in gap junctional coupling via connexin43 in a rat model of aorto-caval fistula at 21 weeks. Here we set to analyze the electrophysiological and protein expression changes in the left ventricle and correlate them with phenotypic severity based upon ventricles to body weight ratio. ECG analysis showed increased amplitude and duration of the P wave, prolongation of PR and QRS interval, ST segment elevation and decreased T wave amplitude in the fistula group. Optical mapping showed a prolongation of action potential duration in the hypertrophied hearts. Minimal conduction velocity (CV) showed a bell-shaped curve, with a significant increase in the mild cases and there was a negative correlation of both minimal and maximal CV with heart to body weight ratio. Since the CV is influenced by gap junctional coupling as well as the autonomic nervous system, we measured the amounts of tyrosine hydroxylase (TH) and choline acetyl transferase (ChAT) as a proxy for sympathetic and parasympathetic innervation, respectively. At the protein level, we confirmed a significant decrease in total and phosphorylated connexin43 that was proportional to the level of hypertrophy, and similarly decreased levels of TH and ChAT. Even at a single time-point, severity of morphological phenotype correlates with progression of molecular and electrophysiological changes, with the most hypertrophied hearts showing the most severe changes that might be related to arrhythmogenesis. PMID:27610087

  20. Postoperative Fluid Overload is a Useful Predictor of the Short-Term Outcome of Renal Replacement Therapy for Acute Kidney Injury After Cardiac Surgery

    PubMed Central

    Xu, Jiarui; Shen, Bo; Fang, Yi; Liu, Zhonghua; Zou, Jianzhou; Liu, Lan; Wang, Chunsheng; Ding, Xiaoqiang; Teng, Jie

    2015-01-01

    Abstract To analyze the predictive value of postoperative percent fluid overload (PFO) of renal replacement therapy (RRT) for acute kidney injury (AKI) patients after cardiac surgery. Data from 280 cardiac surgery patients between 2005 January and 2012 April were collected for retrospective analyses. A receiver operating characteristic (ROC) curve was used to compare the predictive values of cumulative PFO at different times after surgery for 90-day mortality. The cumulative PFO before RRT initiation was 7.9% ± 7.1% and the median PFO 6.1%. The cumulative PFO before and after RRT initiation in intensive care unit (ICU) was higher in the death group than in the survival group (8.8% ± 7.6% vs 6.1% ± 5.6%, P = 0.001; −0.5[−5.6, 5.1]% vs 6.9[2.2, 14.6]%, P < 0.001). The cumulative PFO during the whole ICU stay was 14.3% ± 15.8% and the median PFO was 10.7%. The areas under the ROC curves to predict the 90-day mortality by PFO at 24 hours, cumulative PFO before and after RRT initiation, and PFO during the whole ICU stay postoperatively were 0.625, 0.627, 0.731, and 0.752. PFO during the whole ICU stay ≥7.2% was determined as the cut-off point for 90-day mortality prediction with a sensitivity of 77% and a specificity of 64%. Kaplan–Meier survival estimates showed a significant difference in survival among patients with cumulative PFO ≥ 7.2% and PFO < 7.2% after cardiac surgery (log-rank P < 0.001). Postoperative cumulative PFO during the whole ICU stay ≥7.2% would have an adverse effect on 90-day short-term outcome, which may provide a strategy for the volume control of AKI-RRT patients after cardiac surgery. PMID:26287422

  1. 'Volume-expanded' hypertension: the effect of fluid overload and the role of the sympathetic nervous system in salt-dependent hypertension.

    PubMed

    Gavras, Irene; Gavras, Haralambos

    2012-04-01

    It is widely believed that salt-dependent hypertension is induced and maintained by expansion of intravascular fluid volume resulting from excessive retention of sodium. The purpose of this brief article is to present a series of arguments in support of the thesis that volume overload per se does not raise the arterial blood pressure. Several investigators in the 1960s and 1970s reported that excessive retention of salt - regardless of cause - leads to sympathetic activation mediated by the effects of the Na ion on α(2)-adrenergic receptors located mostly in the brainstem. In recent years, the cloning and characterization of α(2)-adrenergic receptors subtypes permitted differentiation of their hemodynamic effects via use of salt loading of nephrectomized animals submitted to genetic engineering or gene treatment. These studies indicate that sodium alters the balance between the sympathoinhibitory α(2A)-adrenergic receptors and the sympathoexcitatory α(2B)-adrenergic receptors, leading to a hyperadrenergic hypertensive state unrelated to volume overload. PMID:22227820

  2. Abnormal cerebellar volume in acute and remitted major depression.

    PubMed

    Depping, Malte S; Wolf, Nadine D; Vasic, Nenad; Sambataro, Fabio; Hirjak, Dusan; Thomann, Philipp A; Wolf, Robert C

    2016-11-01

    Abnormal cortical volume is well-documented in patients with major depressive disorder (MDD), but cerebellar findings have been heterogeneous. It is unclear whether abnormal cerebellar structure relates to disease state or medication. In this study, using structural MRI, we investigated cerebellar volume in clinically acute (with and without psychotropic treatment) and remitted MDD patients. High-resolution structural MRI data at 3T were obtained from acute medicated (n=29), acute unmedicated (n=14) and remitted patients (n=16). Data from 29 healthy controls were used for comparison purposes. Cerebellar volume was investigated using cerebellum-optimized voxel-based analysis methods. Patients with an acute MDD episode showed increased volume of left cerebellar area IX, and this was true for both medicated and unmedicated individuals (p<0.05 cluster-corrected). Remitted patients exhibited bilaterally increased area IX volume. In remitted, but not in acutely ill patients, area IX volume was significantly associated with measures of depression severity, as assessed by the Hamilton Depression Rating Scale (HAMD). In addition, area IX volume in remitted patients was significantly related to the duration of antidepressant treatment. In acutely ill patients, no significant relationships were established using clinical variables, such as HAMD, illness or treatment duration and number of depressive episodes. The data suggest that cerebellar area IX, a non-motor region that belongs to a large-scale brain functional network with known relevance to core depressive symptom expression, exhibits abnormal volume in patients independent of clinical severity or medication. Thus, the data imply a possible trait marker of the disorder. However, given bilaterality and an association with clinical scores at least in remitted patients, the current findings raise the possibility that cerebellar volume may be reflective of successful treatment as well. PMID:27321187

  3. Accuracy and Reproducibility of Right Ventricular Quantification in Patients with Pressure and Volume Overload Using Single-Beat Three-Dimensional Echocardiography

    PubMed Central

    Knight, Daniel S.; Grasso, Agata E.; Quail, Michael A.; Muthurangu, Vivek; Taylor, Andrew M.; Toumpanakis, Christos; Caplin, Martyn E.; Coghlan, J. Gerry; Davar, Joseph

    2015-01-01

    Background The right ventricle is a complex structure that is challenging to quantify by two-dimensional (2D) echocardiography. Unlike disk summation three-dimensional (3D) echocardiography (3DE), single-beat 3DE can acquire large volumes at high volume rates in one cardiac cycle, avoiding stitching artifacts or long breath-holds. The aim of this study was to assess the accuracy and test-retest reproducibility of single-beat 3DE for quantifying right ventricular (RV) volumes in adult populations of acquired RV pressure or volume overload, namely, pulmonary hypertension (PH) and carcinoid heart disease, respectively. Three-dimensional and 2D echocardiographic indices were also compared for identifying RV dysfunction in PH. Methods A prospective cross-sectional study was performed in 100 individuals who underwent 2D echocardiography, 3DE, and cardiac magnetic resonance imaging: 49 patients with PH, 20 with carcinoid heart disease, 11 with metastatic carcinoid tumors without cardiac involvement, and 20 healthy volunteers. Two operators performed test-retest acquisition and postprocessing for inter- and intraobserver reproducibility in 20 subjects. Results: RV single-beat 3DE was attainable in 96% of cases, with mean volume rates of 32 to 45 volumes/sec. Bland-Altman analysis of all subjects (presented as mean bias ± 95% limits of agreement) revealed good agreement for end-diastolic volume (−2.3 ± 27.4 mL) and end-systolic volume (5.2 ± 19.0 mL) measured by 3DE and cardiac magnetic resonance imaging, with a tendency to underestimate stroke volume (−7.5 ± 23.6 mL) and ejection fraction (−4.6 ± 13.8%) by 3DE. Subgroup analysis demonstrated a greater bias for volumetric underestimation, particularly in healthy volunteers (end-diastolic volume, −11.9 ± 18.0 mL; stroke volume, −11.2 ± 20.2 mL). Receiver operating characteristic curve analysis showed that 3DE-derived ejection fraction was significantly superior to 2D echocardiographic

  4. N-methyl-D-aspartate receptor-mediated mitochondrial Ca(2+) overload in acute excitotoxic motor neuron death: a mechanism distinct from chronic neurotoxicity after Ca(2+) influx.

    PubMed

    Urushitani, M; Nakamizo, T; Inoue, R; Sawada, H; Kihara, T; Honda, K; Akaike, A; Shimohama, S

    2001-03-01

    Mitochondrial uptake of Ca(2+) has recently been found to play an important role in glutamate-induced neurotoxicity (GNT) as well as in the activation of Ca(2+)-dependent molecules, such as calmodulin and neuronal nitric oxide synthase (nNOS), in the cytoplasm. Prolonged exposure to glutamate injures motor neurons predominantly through the activation of Ca(2+)/calmodulin-nNOS, as previously reported, and is, in part, associated with the pathogenesis of amyotrophic lateral sclerosis (ALS). In the present study, we investigated how mitochondrial uptake of Ca(2+) is involved in GNT in spinal motor neurons. Acute excitotoxicity induced by exposure to 0.5 mM glutamate for 5 min was found in both motor and nonmotor neurons in cultured spinal cords from rat embryos and was dependent on extracellular Ca(2+) and on N-methyl-D-aspartate (NMDA) receptor activation. Mitochondrial uncouplers markedly blocked acute excitotoxicity, and membrane-permeable superoxide dismutase mimics attenuated acute excitotoxicity induced by glutamate and NMDA but not by alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) or kainate. Fluorimetric analysis showed that mitochondrial Ca(2+) was elevated promptly with subsequent accumulation of reactive oxygen species (ROS) in the mitochondria. An NMDA receptor antagonist and a mitochondrial uncoupler eliminated the increase in fluorescence of mitochondrial Ca(2+) and ROS indicators. These data indicate that acute excitotoxicity in spinal neurons is mediated by mitochondrial Ca(2+) overload and ROS generation through the activation of NMDA receptors. This mechanism is different from that of chronic GNT. PMID:11223912

  5. Role of non-transferrin bound iron in iron overload and liver dysfunction in long term survivors of acute leukaemia and bone marrow transplantation.

    PubMed Central

    Harrison, P; Neilson, J R; Marwah, S S; Madden, L; Bareford, D; Milligan, D W

    1996-01-01

    AIMS: To determine whether nontransferrin bound iron is present in the serum of long term survivors of acute leukaemia and bone marrow transplantation who have liver dysfunction as indicated by consistently raised serum aspartate aminotransferase (AST) activities. METHODS: Thirty eight patients, who were at least three years from the end of treatment, were studied. Serum samples were analysed for hepatitis C, hepatitis B, AST, ferritin, and non-transferrin bound iron. A bleomycin based assay was used to detect non-transferrin bound iron. Patient and blood bank records were examined to determine the number of units of transfused blood received by each patient. RESULTS: Ten patients had consistently raised serum AST activities. Of these, two had evidence of hepatitis C infection, one had chronic hepatitis B infection and one had chronic graft versus host disease affecting the liver. None of these four patients had detectable non-transferrin bound iron. The remaining six patients had no obvious reason for raised AST activities, but four had non-transferrin bound iron detectable in their serum as compared with only two out of 28 patients with normal AST activities. Patients with abnormal AST activities had higher serum ferritin concentrations than those with normal AST, though serum ferritin was raised in 21 of 28 patients without liver dysfunction. CONCLUSION: Non-transferrin bound iron may be found in this group of patients, suggesting that iron overload is the cause of the observed liver dysfunction. Non-transferrin bound iron may also be a more specific indicator of iron overload than the serum ferritin concentrations. PMID:8943756

  6. Fluid intake and changes in limb volumes in male ultra-marathoners: does fluid overload lead to peripheral oedema?

    PubMed

    Bracher, Alexia; Knechtle, Beat; Gnädinger, Markus; Bürge, Jolanda; Rüst, Christoph Alexander; Knechtle, Patrizia; Rosemann, Thomas

    2012-03-01

    An increase in body mass due to oedema has been previously described. The aim of this study was to investigate a potential association between both fluid and electrolyte intake and the formation of peripheral oedemas. Fluid and electrolyte intakes and the changes in limb volumes in 50 male 100-km ultra-marathoners were measured. Pre- and post-race serum sodium concentration ([Na(+)]), serum aldosterone concentration, serum copeptin concentration, serum and urine osmolality and body mass were determined. Fluid intake, renal function parameters and urinary output, as well as the changes of volume in the extremities, were measured. The changes of volume in the limbs were measured using plethysmography. Serum [Na(+)] increased by 1.6%; body mass decreased by 1.9 kg. Serum copeptin and aldosterone concentrations were increased. The change in serum copeptin concentration and the change in serum [Na(+)] correlated positively; the change in serum [Na(+)] and body mass correlated negatively. A mean fluid intake of 0.58 L/h was positively related to running speed and negatively to post-race serum [Na(+)]. Total fluid intake was positively related to the changes in both arm and lower leg volumes. Running speed was positively associated with the changes in arm and lower leg volumes; race time was related to the changes in serum copeptin or aldosterone concentrations. To conclude, fluid intake was related to the changes in limb volumes, where athletes with an increased fluid intake developed an increase in limb volumes. PMID:21720884

  7. Acute plasma volume change with high-intensity sprint exercise.

    PubMed

    Bloomer, Richard J; Farney, Tyler M

    2013-10-01

    When exercise is of long duration or of moderate to high intensity, a decrease in plasma volume can be observed. This has been noted for both aerobic and resistance exercise, but few data are available with regard to high-intensity sprint exercise. We measured plasma volume before and after 3 different bouts of acute exercise, of varying intensity, and/or duration. On different days, men (n = 12; 21-35 years) performed aerobic cycle exercise (60 minutes at 70% heart rate reserve) and 2 different bouts of cycle sprints (five 60-second sprints at 100% maximum wattage obtained during graded exercise testing (GXT) and ten 15-second sprints at 200% maximum wattage obtained during GXT). Blood was collected before and 0, 30, and 60 minutes postexercise and analyzed for hematocrit and hemoglobin and plasma volume was calculated. Plasma volume decreased significantly for all exercise bouts (p < 0.05), with the greatest decrease noted 0 minute postexercise for both sprint bouts (∼19%) compared with aerobic exercise bouts (∼11%). By 30 minutes postexercise, plasma volume approached pre-exercise values. We conclude that acute bouts of exercise, in particular high-intensity sprint exercise, significantly decrease plasma volume during the immediate postexercise period. It is unknown what, if any negative implications these transient changes may have on exercise performance. Strength and conditioning professionals may aim to rehydrate athletes appropriately after high-intensity exercise bouts. PMID:23302756

  8. Volume-Related Weight Gain and Subsequent Mortality in Acute Renal Failure Patients Treated with Continuous Renal Replacement Therapy

    PubMed Central

    Fülöp, Tibor; Pathak, Minesh B.; Schmidt, Darren W.; Lengvárszky, Zsolt; Juncos, Julio P.; Lebrun, Christopher J.; Brar, Harjeet; Juncos, Luis A

    2010-01-01

    Fluid overload is a frequent finding in critically ill patients suffering from acute kidney injury (AKI). To assess the impact of fluid overload on the mortality of AKI patients treated with continuous renal replacement therapy (CRRT), we used a registry of eighty-one critically ill patients with AKI initiated on CRRT assembled over an 18 month period to conduct a cross-sectional analysis using volume-related weight gain (VRWG) of ≥10 and ≥20% of body weight, and oliguria (20 ≤mL/hour) as the principal variables, with the primary outcome measure being mortality at 30 days. Mean Apache II scores were 27.5±6.9 with overall cohort mortality of 50.6%. Mean (±SD) VRWG was 8.3±9.6 kg, representing a 10.2±13.5% increase since admission. Oliguria was present in 65.4% of patients. OR for mortality on univariate analysis was increased to 2.62 (95% CI: 1.07-6.44) by a VRWG ≥10% and to 3.22 (95% CI: 1.23-8.45) by oliguria. VRWG ≥20% had OR of 3.98 (95% CI: 1.01-15.75; p=0.049) for mortality. Both VRWG ≥10% (OR 2.71, p=0.040) and oliguria (OR 3.04, p=0.032) maintained their statistically significant association with mortality in multivariate models that included sepsis and Apache II score. In conclusion, fluid overload is an important prognostic factor for survival in critically ill AKI patients treated with CRRT. Further studies are needed to elicit mechanisms and develop appropriate interventions. PMID:20559136

  9. Association of Right Ventricular Pressure and Volume Overload with Non-Ischemic Septal Fibrosis on Cardiac Magnetic Resonance

    PubMed Central

    Kim, Jiwon; Medicherla, Chaitanya B.; Ma, Claudia L.; Feher, Attila; Kukar, Nina; Geevarghese, Alexi; Goyal, Parag; Horn, Evelyn; Devereux, Richard B.; Weinsaft, Jonathan W.

    2016-01-01

    Background Non-ischemic fibrosis (NIF) on cardiac magnetic resonance (CMR) has been linked to poor prognosis, but its association with adverse right ventricular (RV) remodeling is unknown. This study examined a broad cohort of patients with RV dysfunction, so as to identify relationships between NIF and RV remodeling indices, including RV pressure load, volume and wall stress. Methods and Results The population comprised patients with RV dysfunction (EF<50%) undergoing CMR and transthoracic echo within a 14 day (5±3) interval. Cardiac structure, function, and NIF were assessed on CMR. Pulmonary artery systolic pressure (PASP) was measured on echo. 118 patients with RV dysfunction were studied, among whom 47% had NIF. Patients with NIF had lower RVEF (34±10 vs. 39±9%; p = 0.01) but similar LVEF (40±21 vs. 39±18%; p = 0.7) and LV volumes (p = NS). RV wall stress was higher with NIF (17±7 vs. 12±6 kPa; p<0.001) corresponding to increased RV end-systolic volume (143±79 vs. 110±36 ml; p = 0.006), myocardial mass (60±21 vs. 53±17 gm; p = 0.04), and PASP (52±18 vs. 41±18 mmHg; p = 0.001). NIF was associated with increased wall stress among subgroups with isolated RV (p = 0.005) and both RV and LV dysfunction (p = 0.003). In multivariable analysis, NIF was independently associated with RV volume (OR = 1.17 per 10 ml, [CI 1.04–1.32]; p = 0.01) and PASP (OR = 1.43 per 10 mmHg, [1.14–1.81]; p = 0.002) but not RV mass (OR = 0.91 per 10 gm, [0.69–1.20]; p = 0.5) [model χ2 = 21; p<0.001]. NIF prevalence was higher in relation to PA pressure and RV dilation and was > 6-fold more common in the highest, vs. the lowest, common tertile of PASP and RV size (p<0.001). Conclusion Among wall stress components, NIF was independently associated with RV chamber dilation and afterload, supporting the concept that NIF is linked to adverse RV chamber remodeling. PMID:26799498

  10. Nox-derived ROS are acutely activated in pressure overload pulmonary hypertension: indications for a seminal role for mitochondrial Nox4.

    PubMed

    Frazziano, Giovanna; Al Ghouleh, Imad; Baust, Jeff; Shiva, Sruti; Champion, Hunter C; Pagano, Patrick J

    2014-01-15

    Pulmonary arterial hypertension is a severe progressive disease with marked morbidity and high mortality in which right ventricular (RV) failure is the major cause of death. Thus knowledge of the mechanisms underlying RV failure is an area of active interest. Previous studies suggest a role of NADPH oxidase in cardiomyocyte dysfunction in the left heart. Here we postulate that acute pressure overload induced by pulmonary artery banding (PAB) leads to a Nox4-initiated increase in reactive oxygen species (ROS) in mouse RV that may lead to feed-forward induction of Nox2. To test our hypothesis, ROS production was measured in RV and left ventricle homogenates. The data show that hydrogen peroxide (H2O2), but not superoxide anion (O2(·-)), was increased in the early phases (within 6 h) of PAB in RV and that this increase was diminished by catalase and diphenyleneiodonium chloride but not by SOD, N(ω)-nitro-l-arginin methyl ester, febuxostat, or indomethacin. H2O2 production in RV was not attenuated in Nox2 null mice subjected to 6 h PAB. Moreover, we observed an upregulation of Nox4 mRNA after 1 h of PAB and an increase in mitochondrial Nox4 protein 6 h post-PAB. In contrast, we observed an increase in Nox2 mRNA 1 day post-PAB. Expression of antioxidant enzymes SOD, catalase, and glutathione peroxidase did not change, but catalase activity increased 6 h post-PAB. Taken together, these findings show a role of mitochondria-localized Nox4 in the early phase of PAB and suggest an involvement of this isozyme in early ROS generation possibly contributing to progression of RV dysfunction and failure. PMID:24213612

  11. Advancing knowledge of right ventricular pathophysiology in chronic pressure overload: Insights from experimental studies.

    PubMed

    Guihaire, Julien; Noly, Pierre Emmanuel; Schrepfer, Sonja; Mercier, Olaf

    2015-10-01

    The right ventricle (RV) has to face major changes in loading conditions due to cardiovascular diseases and pulmonary vascular disorders. Clinical experience supports evidence that the RV better compensates for volume than for pressure overload, and for chronic than for acute changes. For a long time, right ventricular (RV) pathophysiology has been restricted to patterns extrapolated from left heart studies. However, the two ventricles are anatomically, haemodynamically and functionally distinct. RV metabolic properties may also result in a different behaviour in response to pathological conditions compared with the left ventricle. In this review, current knowledge of RV pathophysiology is reported in the setting of chronic pressure overload, including recent experimental findings and emerging concepts. After a time-varying compensated period with preserved cardiac output despite overload conditions, RV failure finally occurs, leading to death. The underlying mechanisms involved in the transition from compensatory hypertrophy to maladaptive remodelling are not completely understood. PMID:26184869

  12. Combination of Urinary Sodium/Creatinine Ratio and Plasma Brain Natriuretic Peptide Level Predicts Successful Tolvaptan Therapy in Patients With Heart Failure and Volume Overload.

    PubMed

    Sato, Yuichi; Dohi, Kaoru; Watanabe, Kiyotaka; Tanimura, Muneyoshi; Takeuchi, Tetsushiro; Sugiura, Emiyo; Sugimoto, Tadafumi; Kumagai, Naoto; Ogura, Toru; Nakamori, Shiro; Fujimoto, Naoki; Yamada, Norikazu; Ito, Masaaki

    2016-01-01

    To evaluate the short-term clinical and hemodynamic effects of tolvaptan therapy and to identify predictors of the therapeutic outcomes, we retrospectively recruited 60 consecutive hospitalized heart failure (HF) patients (70 ± 11 years) with volume overload. The subjects were divided into two groups on the basis of the changes in HF symptom scores and hemodynamic status assessed by right heart catheterization after tolvaptan therapy (median: 7 days). The majority of patients were successfully treated (group 1). However, 22% of patients (group 2) were unsuccessfully treated, in whom 1) the HF symptom score worsened or 2) there was a stationary HF symptom score ≥ 6 points, and mean PCWP > 18 mmHg and mean RAP > 10 mmHg, after tolvaptan therapy. HF symptom scores, hemodynamic parameters, and plasma brain natriuretic peptide (BNP) level improved in group 1, but all of these parameters remained unchanged in group 2. Lower urine sodium/creatinine ratio (UNa/UCr) and higher BNP level at baseline were independently associated with unsuccessful tolvaptan therapy, and UNa/UCr best predicts unsuccessful tolvaptan therapy with a cut-off value of 46.5 mEq/g·Cr (AUC 0.847, 95% CI: 0.718-0.976, sensitivity 77%, specificity 81%, P < 0.01). Double-positive results of UNa/UCr < 46.5 mEq/g·Cr and plasma BNP level > 778 pg/mL predicted unsuccessful tolvaptan therapy with high diagnostic accuracy (sensitivity 54%, specificity 100%, positive predictive value 100%, negative predictive value 89%, and accuracy 90%). In summary, short-term tolvaptan therapy ameliorated HF symptoms and provided hemodynamic improvement in the majority of patients, and UNa/UCr and BNP level strongly predicted the therapeutic outcomes. PMID:26973271

  13. Apamin-Sensitive Small Conductance Calcium-Activated Potassium Channels were Negatively Regulated by Captopril in Volume-Overload Heart Failure Rats.

    PubMed

    Hongyuan, Bai; Xin, Dong; Jingwen, Zhang; Li, Gao; Yajuan, Ni

    2016-08-01

    In heart failure (HF), the malignant arrhythmias occur frequently; a study demonstrated that upregulation of I KAS resulted in recurrent spontaneous ventricular fibrillation in HF. However, the regulation of SK channels was poorly understood. The activation of SK channels depended on [Ca(2+)]i and PP2A; studies suggested that angiotensin II can regulate them. So, we hypothesized that in HF, the excess of angiotensin may regulate the SK channels and result in the remodeling of SK channels. To test the hypothesis, we used volume-overload-induced HF rat model, treated with captopril, performed whole-cell patch clamp to record apamin-sensitive currents (I KAS), and I-V curve was studied. The sensitivity of I KAS to [Ca(2+)]i was also explored by setting various [Ca(2+)]i (10, 100, 500, 900, 1000, and 10,000 nM), and the steady-state Ca(2+) response of I KAS was attained and performed Hill fitting with the equation (y = 1/[1 + (EC50/x) (n) ]). Immunofluorescent staining, real-time PCR, Western blot were also carried out to furtherly investigate the underlying molecular mechanisms of the regulation. Captopril significantly decreased the mean density of I KAS when [Ca(2+)]i was 500, 900, 1000, and 10000 nM. The Hill fitting showed significantly different EC50 values and the Hill coefficients and showed captopril significantly shifted rightward the steady-state Ca(2+) response of I KAS. The results of real-time PCR and Western blot demonstrated captopril decreased the mRNA and protein expression of SK3 channels. Captopril significantly downregulated the sensitivity of SK channels to [Ca(2+)]i and the SK3 channels expression in HF, and reversed the SK channels remodeling. PMID:26924798

  14. Acute volume loading and exercise capacity in postural tachycardia syndrome

    PubMed Central

    Figueroa, Rocío A.; Arnold, Amy C.; Nwazue, Victor C.; Okamoto, Luis E.; Paranjape, Sachin Y.; Black, Bonnie K.; Diedrich, Andre; Robertson, David; Biaggioni, Italo; Raj, Satish R.

    2014-01-01

    Postural tachycardia syndrome (POTS) is associated with exercise intolerance, hypovolemia, and cardiac atrophy, which may contribute to reduced stroke volume and compensatory exaggerated heart rate (HR) increases. Acute volume loading with intravenous (iv) saline reduces HR and improves orthostatic tolerance and symptoms in POTS, but its effect on exercise capacity is unknown. In this study, we determined the effect of iv saline infusion on peak exercise capacity (V̇o2peak) in POTS. Nineteen patients with POTS participated in a sequential study. V̇o2peak was measured on two separate study days, following administration of placebo or 1 liter of iv saline (NaCl 0.9%). Patients exercised on a semirecumbent bicycle with resistance increased by 25 W every 2 min until maximal effort was achieved. Patients exhibited blood volume deficits (−13.4 ± 1.4% ideal volume), consistent with mild to moderate hypovolemia. At baseline, saline significantly increased stroke volume (saline 80 ± 8 ml vs. placebo 64 ± 4 ml; P = 0.010), increased cardiac output (saline 6.9 ± 0.5 liter/min vs. placebo 5.7 ± 0.2 liter/min; P = 0.021), and reduced systemic vascular resistance (saline 992.6 ± 70.0 dyn-s/cm5 vs. placebo 1,184.0 ± 50.8 dyn-s/cm5; P = 0.011), with no effect on HR or blood pressure. During exercise, saline did not produce differences in V̇o2peak (saline 26.3 ± 1.2 mg·kg−1·min−1 vs. placebo 27.7 ± 1.8 mg·kg−1·min−1; P = 0.615), peak HR [saline 174 ± 4 beats per minute (bpm) vs. placebo 175 ± 3 bpm; P = 0.672] or other cardiovascular parameters. These findings suggest that acute volume loading with saline does not improve V̇o2peak or cardiovascular responses to exercise in POTS, despite improvements in resting hemodynamic function. PMID:25059240

  15. Death by information overload.

    PubMed

    Hemp, Paul

    2009-09-01

    The value of information in the knowledge economy is indisputable, but so is its capacity to overwhelm consumers of it. HBR contributing editor Hemp reports on practical ways for individuals and organizations to avoid getting too much of a good thing. Ready access to useful information comes at a cost: As the volume increases, the line between the worthwhile and the distracting starts to blur. And ready access to you--via e-mail, social networking, and so on--exacerbates the situation: On average, Intel executives get 300 e-mails a day, and Microsoft workers need 24 minutes to return to work after each e-mail interruption. Clearly, productivity is taking a hit. Technological aids can help, such as e-mail management software for you, a message-volume regulation system for your organization, or even more-sophisticated solutions being developed by Microsoft, IBM, and others. Yet, battling technological interruptions on their own turf only goes so far. You also need to change your mind-set, perhaps by seeking help from personal-productivity experts or by simply accepting that you can't respond to every distraction that flits across your screen. Similarly, organizations must change their cultures, for instance by establishing clear e-communication protocols. In the end, only a multipronged approach will help you and your organization subdue the multiheaded monster of information overload. The secret is to manage the beast while still respecting it for the beautiful creature it is. PMID:19736853

  16. Iron overload in hematopoietic cell transplantation.

    PubMed

    Majhail, N S; Lazarus, H M; Burns, L J

    2008-06-01

    Iron overload, primarily related to RBC transfusions, is a relatively common complication in hematopoietic cell transplant (HCT) recipients. Iron overload increases the risk of infections, veno-occlusive disease and hepatic dysfunction post transplant. Elevated pretransplant ferritin levels have been reported to increase the risk of nonrelapse mortality following HCT and might influence the risk of acute and chronic GVHD. Serum ferritin is sensitive but not specific for iron overload and is a poor predictor of body iron burden. Estimation of hepatic iron content with a liver biopsy or magnetic resonance imaging should be considered prior to initiating therapy for post transplant iron overload. A subgroup of transplant survivors with mild iron overload and no end-organ damage may not need therapy. Phlebotomy is the treatment of choice with iron-chelation therapy reserved for patients not eligible for phlebotomy. Natural history, evolution and treatment of iron overload in transplant survivors have not been adequately investigated and more studies are needed to determine its impact on short-term and long-term morbidity and mortality. PMID:18438425

  17. Baroreflex Responses to Acute Changes in Blood Volume in Humans

    NASA Technical Reports Server (NTRS)

    Thompson, Cynthia A.; Tatro, Dana L.; Ludwig, David A.; Convertino, Victor A.

    1990-01-01

    To test the hypothesis that acute changes in plasma volume affect the stimulus-response relations of high- and low- pressure baroreflexes, eight men (27-44 yr old) underwent measurements for carotid-cardiac and cardiopulmonary baro- reflex responses under the following three volemic conditions: hypovolemic, normovolemic, and hypervolemic. The stimulus- response relation of the carotid-cardiac response curve was generated using a neck cuff device, which delivered pressure changes between +40 and -65 mmHg in continuous steps of 15 mmHg. The stimulus-response relationships of the cardiopulmonary baroreflex were studied by measurements of Forearm Vascular Resistance (FVR) and Peripheral Venotis Pressure (PVP) during low levels of lower body negative pressure (O to -20 mmHg). Altered vascular volume had no effect on response relations of the carotid-cardiac baroreflex but did alter the gain of the cardiopulmonary baroreflex (-7.93 q 1.71, -4.36 q 1.38, and -2.56 q 1.59 peripheral resistance units/mmHg for hypovolemic, normovolemic, and hypervolemic, respectively) independent of shifts in baseline FVR and PVP. These results indicate greater demand for vasoconstriction for equal reductions in venous pressure during progressive hypovolemia; this condition may compromise the capacity to provide adequate peripheral resistance during severe orthostatic stress. Fluid loading before reentry after spaceflight may act to restore vasoconstrictive capacity of the cardiopulnionary baroreflex but may not be an effective countermeasure against potential post- flight impairment of the carotid-cardiac baroreflex.

  18. The effect of an acute increase in central blood volume on the response of cerebral blood flow to acute hypotension.

    PubMed

    Ogoh, Shigehiko; Hirasawa, Ai; Sugawara, Jun; Nakahara, Hidehiro; Ueda, Shinya; Shoemaker, J Kevin; Miyamoto, Tadayoshi

    2015-09-01

    The purpose of the present study was to examine whether the response of cerebral blood flow to an acute change in perfusion pressure is modified by an acute increase in central blood volume. Nine young, healthy subjects voluntarily participated in this study. To measure dynamic cerebral autoregulation during normocapnic and hypercapnic (5%) conditions, the change in middle cerebral artery mean blood flow velocity was analyzed during acute hypotension caused by two methods: 1) thigh-cuff occlusion release (without change in central blood volume); and 2) during the recovery phase immediately following release of lower body negative pressure (LBNP; -50 mmHg) that initiated an acute increase in central blood volume. In the thigh-cuff occlusion release protocol, as expected, hypercapnia decreased the rate of regulation, as an index of dynamic cerebral autoregulation (0.236 ± 0.018 and 0.167 ± 0.025 s(-1), P = 0.024). Compared with the cuff-occlusion release, the acute increase in central blood volume (relative to the LBNP condition) with LBNP release attenuated dynamic cerebral autoregulation (P = 0.009). Therefore, the hypercapnia-induced attenuation of dynamic cerebral autoregulation was not observed in the LBNP release protocol (P = 0.574). These findings suggest that an acute change in systemic blood distribution modifies dynamic cerebral autoregulation during acute hypotension. PMID:26159757

  19. Prediction of acute cardiac rejection by changes in left ventricular volumes

    SciTech Connect

    Novitzky, D.; Cooper, D.K.; Boniaszczuk, J.

    1988-11-01

    Sixteen patients underwent heart transplantation (11 orthotopic, five heterotopic). Monitoring for acute rejection was by both endomyocardial biopsy (EMB) and multigated equilibrium blood pool scanning with technetium 99m-labelled red blood cells. From the scans information was obtained on left ventricular volumes (stroke, end-diastolic, and end-systolic), ejection fraction, and heart rate. Studies (208) were made in the 16 patients. There was a highly significant correlation between the reduction in stroke volume and end-diastolic volume (and a less significant correlation in end-systolic volume) and increasing acute rejection seen on EMB. Heart rate and ejection fraction did not correlate with the development of acute rejection. Correlation of a combination of changes in stroke volume and end-diastolic volume with EMB showed a sensitivity of 85% and a specificity of 96%. Radionuclide scanning is therefore a useful noninvasive tool for monitoring acute rejection.

  20. Signs of Overload

    MedlinePlus

    ... Listen Text Size Email Print Share Signs of Overload Page Content Article Body Although stress is a ... 12 (Copyright © 2004 American Academy of Pediatrics) The information contained on this Web site should not be ...

  1. Inhibition of soluble epoxide hydrolase does not improve the course of congestive heart failure and the development of renal dysfunction in rats with volume overload induced by aorto-caval fistula

    PubMed Central

    Červenka, Luděk; Melenovský, Vojtěch; Husková, Zuzana; Sporková, Alexandra; Bürgelová, Marcela; Škaroupková, Petra; Hwang, Sung Hee; Hammock, Bruce D.; Imig, John D.; Sadowski, Janusz

    2016-01-01

    The detailed mechanisms determining the course of congestive heart failure (CHF) and associated renal dysfunction remain unclear. In a volume overload model of CHF induced by creation of aorto-caval fistula (ACF) in Hannover Sprague-Dawley (HanSD) rats we explored the putative pathogenetic contribution of epoxyeicosatrienoic acids (EETs), active products of CYP-450 dependent epoxygenase pathway of arachidonic acid metabolism, and compared it with the role of the renin-angiotensin system (RAS). Chronic treatment with cis-4-[4-(3-adamantan-1-yl-ureido) cyclohexyloxy]benzoic acid (c-AUCB, 3 mg/L in drinking water), an inhibitor of soluble epoxide hydrolase (sEH) which normally degrades EETs, increased intrarenal and myocardial EETs to levels observed in sham-operated HanSD rats, but did not improve the survival or renal function impairment. In contrast, chronic angiotensin-converting enzyme inhibition (ACEi, trandolapril, 6 mg/L in drinking water) increased renal blood flow, fractional sodium excretion and markedly improved survival, without affecting left ventricular structure and performance. Hence, renal dysfunction rather than cardiac remodeling determines long-term mortality in advanced stage of CHF due to volume overload. Strong protective actions of ACEi were associated with suppression of the vasoconstrictor/sodium retaining axis and activation of vasodilatory/natriuretic axis of the renin-angiotensin system in the circulating blood and kidney tissue. PMID:26047375

  2. Baroreflex Responses to Acute Changes in Blood Volume in Humans

    NASA Technical Reports Server (NTRS)

    Thompson, Cynthia A.; Tatro, Dana L.; Ludwig, David A.; Convertino, Victor A.

    1990-01-01

    To test the hypothesis that acute changes in plasma volume affect the stimulus-response relations of high- and low- pressure baroreflexes, eight men (27-44 yr old) underwent measurements for carotid-cardiac and cardiopulmonary baro-reflex responses under the following three volemic conditions: hypovolemic, normovolemic, and hypervolemic. The stimulus- response relation of the carotid-cardiac response curve was generated using a neck cuff device, which delivered pressure changes between +40 and -65 mmHg in continuous steps of 15 mmHg. The stimulus-response relationship, of the cardio-pulmonary baroreflex were studied by measurements of Forearm Vascular Resistance (FVR) and Peripheral Venous Pressure (PVP) during low levels of lower body negative pressure (O to -20 mmHg). The results indicate greater demand for vasoconstriction for equal reductions in venous pressure during progressive hypovolemia; this condition may compromise the capacity to provide adequate peripheral resistance during severe orthostatic stress. Fluid loading before reentry after spaceflight may act to restore vasoconstrictive capacity of the cardiopulmonary baroreflex but may not be an effective countermeasure against potential post- flight impairment of the carotid-cardiac baroreflex.

  3. Iron overload in sickle cell disease.

    PubMed

    Raghupathy, Radha; Manwani, Deepa; Little, Jane A

    2010-01-01

    In sickle cell disease transfusions improve blood flow by reducing the proportion of red cells capable of forming sickle hemoglobin polymer. This limits hemolysis and the endothelial damage that result from high proportions of sickle polymer-containing red cells. Additionally, transfusions are used to increase blood oxygen carrying capacity in sickle cell patients with severe chronic anemia or with severe anemic episodes. Transfusion is well-defined as prophylaxis (stroke) and as therapy (acute chest syndrome and stroke) for major complications of sickle cell disease and has been instituted, based on less conclusive data, for a range of additional complications, such as priapism, vaso-occlusive crises, leg ulcers, pulmonary hypertension, and during complicated pregnancies. The major and unavoidable complication of transfusions in sickle cell disease is iron overload. This paper provides an overview of normal iron metabolism, iron overload in transfused patients with sickle cell disease, patterns of end organ damage, diagnosis, treatment, and prevention of iron overload. PMID:20490352

  4. Mean platelet volume and cardiovascular outcomes in acute myocardial infarction

    PubMed Central

    Ranjith, Mangalachulli Pottammal; DivyaRaj, Rajendran; Mathew, Dolly; George, Biju; Krishnan, Mangalath Narayanan

    2016-01-01

    Objective High levels of mean platelet volume (MPV) may be associated with adverse outcomes in patients with myocardial infarction (MI). We examined the association between MPV and the risk of death and adverse cardiovascular outcomes in patients with MI. Methods We studied consecutive patients with MI admitted to a tertiary-care hospital during a period of 1 year. MPV was measured at admission and at third month. Patients were followed up for 1-year primary composite outcome of cardiovascular death, stroke, fatal or non-fatal MI and cardiac failure. Patients were classified according to tertile of baseline MPV. Results A total of 1206 patients with MI, including 934 men (77.4%) and 272 women (22.6%) were studied. The mean age of the study population was 56 years. At 1-year follow-up, 292 (28.57%) primary outcome occurred: cardiovascular mortality 78 (7.6%), fatal or non-fatal MI 153 (15.0%), stroke 30 (2.9%) and cardiac failure 128 (12.52%). Patients with the highest tertile MPV had higher primary outcome as compared with those with MPV in the lowest tertile (adjusted OR=2.31; 95% CI 1.60 to 3.35; p<0.001). Total mortality was also more in high-MPV group (adjusted OR 2.62; 95% CI 1.47 to 4.70; p<0.001). There were no significant changes in mean MPV values at admission from those at third month interval (9.15, (SD 0.99) vs 9.19 (SD 0.94); p=0.2). Conclusions Elevated MPV was associated with worse outcome in patients with acute MI. Elevated MPV in these patients may be due to inherently large platelets. Trial registration number http://ctri.nic.in/Clinicaltrials/rmaindet.php?trialid=5485&EncHid=98036.61144&modid=1&compid=19; CTRI/2012/12/003222.

  5. News and the overloaded consumer: factors influencing information overload among news consumers.

    PubMed

    Holton, Avery E; Chyi, Hsiang Iris

    2012-11-01

    News producers continue to increase their volume of production and delivery platforms in an effort to reach and maintain news consumers. However, consumers may not necessarily find more news desirable. Previous studies have suggested that information surplus can lead to negative outcomes for consumers, but research of outcomes related to news production and consumption has been scant. This study explores novel areas of news surplus and overload, empirically examining factors associated with the degree of perceived overload across a broad spectrum of news delivery platforms. The findings reveal that the majority of today's news consumers feel overloaded with the amount of news they are confronted with. Gender, news interest, and the use of specific news platforms and outlets predict the degree of that overload. News access through platforms and outlets such as computers, e-readers, and Facebook is positively associated with overload, whereas other platforms such as television and the iPhone are negatively associated with overload. Implications for media psychology and news consumption are discussed. PMID:23020743

  6. Acute lysine overload provokes protein oxidative damage and reduction of antioxidant defenses in the brain of infant glutaryl-CoA dehydrogenase deficient mice: a role for oxidative stress in GA I neuropathology.

    PubMed

    Seminotti, Bianca; Ribeiro, Rafael Teixeira; Amaral, Alexandre Umpierrez; da Rosa, Mateus Struecker; Pereira, Carolina Coffi; Leipnitz, Guilhian; Koeller, David M; Goodman, Stephen; Woontner, Michael; Wajner, Moacir

    2014-09-15

    We evaluated the antioxidant defense system and protein oxidative damage in the brain and liver of 15-day-old GCDH deficient knockout (Gcdh(-/-)) mice following an acute intraperitoneal administration of Lys (8 μmol/g). We determined reduced glutathione (GSH) concentrations, sulfhydryl content, carbonyl formation and the activities of the antioxidant enzymes glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) in the brain and liver of these animals. 2',7'-dihydrodichlorofluorescein (DCFH) oxidation was also measured as an index of free radical formation. The only parameters altered in Gcdh(-/-) compared to wild type (Gcdh(+/+)) mice were a reduction of liver GSH concentrations and of brain sulfhydryl content. Acute Lys injection provoked a decrease of GSH concentration in the brain and sulfhydryl content in the liver, and an increase in carbonyl formation in the brain and liver of Gcdh(-/-) mice. Lys administration also induced a decrease of all antioxidant enzyme activities in the brain, as well as an increase of the activities of SOD and CAT in the liver of Gcdh(-/-) mice. Finally, Lys elicited a marked increase of DCFH oxidation in the brain and liver. It is concluded that Lys overload compromises the brain antioxidant defenses and induces protein oxidation probably secondary to reactive species generation in infant Gcdh(+/+) mice. PMID:24996493

  7. Interdisciplinary Research and Information Overload.

    ERIC Educational Resources Information Center

    Wilson, Patrick

    1996-01-01

    Discusses information overload and examines several ways in which actual and potential overload affects research choices for the solo researcher in interdisciplinary areas. Topics include information overload and teamwork; entry barriers to certain specialties, including necessary background knowledge; and information utilization and knowledge…

  8. Acute exposure to ethanol potentiates human immunodeficiency virus type 1 Tat-induced Ca(2+) overload and neuronal death in cultured rat cortical neurons.

    PubMed

    Brailoiu, Eugen; Brailoiu, G Cristina; Mameli, Giuseppe; Dolei, Antonina; Sawaya, Bassel E; Dun, Nae J

    2006-02-01

    A significant number of human immunodeficiency virus type 1 (HIV-1)-infected patients are alcoholics. Either alcohol or HIV alone induces morphological and functional damage to the nervous system. HIV-1 Tat is a potent transcriptional activator of the viral promoter, with the ability to modulate a number of cellular regulatory circuits including apoptosis and to cause neuronal injury. To further evaluate the involvement of alcohol in neuronal injury, the authors examined the effect of ethanol on Tat-induced calcium responses in rat cerebral cortical neurons, using microfluorimetric calcium determination. HIV Tat protein (10 or 500 nM) elicited two types of calcium responses in cortical neurons: a fast-onset, short-lasting response and a slow-onset, sustained response. The responses were concentration-dependent and diminished in calcium-free saline. A short exposure to ethanol (50 mM) potentiated both types of calcium response, which was markedly decreased when the cells were pretreated with BAPTA-AM (20 microM). In addition, an increase in the neurotoxic effect of Tat, which was assessed by trypan blue exclusion assay, was observed. The result led the authors to conclude that alcohol exposure significantly potentiates Tat-induced calcium overload and neuronal death. PMID:16595370

  9. Pulmonary Function in Patients with End-Stage Renal Disease: Effects of Hemodialysis and Fluid Overload.

    PubMed

    Yılmaz, Süreyya; Yildirim, Yasar; Yilmaz, Zülfükar; Kara, Ali Veysel; Taylan, Mahsuk; Demir, Melike; Coskunsel, Mehmet; Kadiroglu, Ali Kemal; Yilmaz, Mehmet Emin

    2016-01-01

    BACKGROUND Respiratory system disorders are one of the most prevalent complications in end-stage renal disease patients on hemodialysis. However, the pathogenesis of impaired pulmonary functions has not been completely elucidated in these patients. We designed a study to investigate acute effects of hemodialysis treatment on spirometry parameters, focusing on the relationship between pulmonary function and fluid status in hemodialysis patients. MATERIAL AND METHODS We enrolled 54 hemodialysis patients in this study. Multifrequency bioimpedance analysis (BIA) was used to assess fluid status before and 30 min after the midweek of hemodialysis (HD). Overhydration (OH)/extracellular water (ECW)% ratio was used as an indicator of fluid status. Fluid overload was defined as OH/ECW ≥7%. Spirometry was performed before and after hemodialysis. RESULTS Forced vital capacity (FVC), FVC%, and forced expiratory volume in the first second (FEV1) levels were significantly increased after hemodialysis. FVC, FVC%, FEV1, FEV1%, mean forced expiratory flow between 25% and 75% of the FVC (FEF25-75), FEF25-75%, peak expiratory flow rate (PEFR), and PEFR% were significantly lower in patients with fluid overload than in those without. OH/ECW ratio was negatively correlated with FVC, FVC%, FEV1, FEV1%, FEF25-75, FEF25-75%, PEFR, and PEFR%. Stepwise multiple regression analysis revealed that male sex and increased ultrafiltration volume were independently associated with higher FVC, whereas increased age and OH/ECW ratio were independently associated with lower FVC. CONCLUSIONS Fluid overload is closely associated with restrictive and obstructive respiratory abnormalities in HD patients. In addition, hemodialysis has a beneficial effect on pulmonary function tests, which may be due to reduction of volume overload. PMID:27497672

  10. Pulmonary Function in Patients with End-Stage Renal Disease: Effects of Hemodialysis and Fluid Overload

    PubMed Central

    Yilmaz, Süreyya; Yildirim, Yasar; Yilmaz, Zülfükar; Kara, Ali Veysel; Taylan, Mahsuk; Demir, Melike; Coskunsel, Mehmet; Kadiroglu, Ali Kemal; Yilmaz, Mehmet Emin

    2016-01-01

    Background Respiratory system disorders are one of the most prevalent complications in end-stage renal disease patients on hemodialysis. However, the pathogenesis of impaired pulmonary functions has not been completely elucidated in these patients. We designed a study to investigate acute effects of hemodialysis treatment on spirometry parameters, focusing on the relationship between pulmonary function and fluid status in hemodialysis patients. Material/Methods We enrolled 54 hemodialysis patients in this study. Multifrequency bioimpedance analysis (BIA) was used to assess fluid status before and 30 min after the midweek of hemodialysis (HD). Overhydration (OH)/extracellular water (ECW)% ratio was used as an indicator of fluid status. Fluid overload was defined as OH/ECW ≥7%. Spirometry was performed before and after hemodialysis. Results Forced vital capacity (FVC), FVC%, and forced expiratory volume in the first second (FEV1) levels were significantly increased after hemodialysis. FVC, FVC%, FEV1, FEV1%, mean forced expiratory flow between 25% and 75% of the FVC (FEF25–75), FEF25–75%, peak expiratory flow rate (PEFR), and PEFR% were significantly lower in patients with fluid overload than in those without. OH/ECW ratio was negatively correlated with FVC, FVC%, FEV1, FEV1%, FEF25–75, FEF25–75%, PEFR, and PEFR%. Stepwise multiple regression analysis revealed that male sex and increased ultrafiltration volume were independently associated with higher FVC, whereas increased age and OH/ECW ratio were independently associated with lower FVC. Conclusions Fluid overload is closely associated with restrictive and obstructive respiratory abnormalities in HD patients. In addition, hemodialysis has a beneficial effect on pulmonary function tests, which may be due to reduction of volume overload. PMID:27497672

  11. Transfusion associated circulatory overload.

    PubMed

    Agnihotri, Naveen; Agnihotri, Ajju

    2014-06-01

    Transfusion associated circulatory overload (TACO) is an established, but grossly under diagnosed and underreported complication of blood transfusion. We present the case of a 46-year-old diabetic and hypertensive patient admitted to our hospital for recurrent episodes of urinary retention. Over initial 3 days of the admission, the patient received multiple units of packed red blood cells (RBC) and fresh frozen plasma, uneventfully. However, the patient developed signs and symptoms suggestive of TACO with only small amount of the 4(th) unit of RBC. The patient had to be shifted to the Intensive Care Unit for further management of this complication. Etiology of TACO is more complex than a mere circulatory overload and is still not completely understood. TACO leads to a prolonged hospital stay and morbidity in the patients developing this complication. TACO thus needs to be suspected in patients at risk for this complication. PMID:24987240

  12. The Effect of Pulsatility Index on Infarct Volume in Acute Lacunar Stroke

    PubMed Central

    Kim, Yoon; Lee, Hanbin; An, Se-A; Yim, Byeongsoo; Kim, Jonguk; Kim, Ok Joon; Kim, Won Chan; Kim, Hyun Sook; Oh, Seung Hun

    2016-01-01

    Purpose Lacunar stroke, in the context of small vessel disease, is a type of cerebral infarction caused by occlusion of a penetrating artery. Pulsatility index (PI) is an easily measurable parameter in Transcranial Doppler ultrasound (TCD) study. PI reflects distal cerebral vascular resistance and has been interpreted as a surrogate marker of small vessel disease. We hypothesized that an increased PI, a marker of small vessel disease, might be associated with a larger infarct volume in acute lacunar stroke. Materials and Methods This study included 64 patients with acute lacunar stroke who underwent TCD and brain MRI. We evaluated the association between the mean PI value of bilateral middle cerebral arteries and infarct volume on diffusion-weighted MRI using univariate and multivariate linear regression. Results The mean infarct volume and PI were 482.18±406.40 mm3 and 0.86±0.18, respectively. On univariate linear regression, there was a significant positive association between PI and infarct volume (p=0.001). In the multivariate model, a single standard deviation increase of PI (per 0.18) was associated with an increase of 139.05 mm3 in infarct volume (95% confidence interval, 21.25 to 256.85; p=0.022). Conclusion We demonstrated that PI was an independent determinant of infarct volume in acute lacunar stroke. The PI value measured in acute stroke may be a surrogate marker of the extent of ischemic injury. PMID:27189290

  13. Temperature-based on-column solute focusing in capillary liquid chromatography reduces peak broadening from precolumn dispersion and volume overload when used alone or with solvent-based focusing

    PubMed Central

    Groskreutz, Stephen R.; Horner, Anthony R.; Weber, Stephen G.

    2015-01-01

    On-column focusing is essential for satisfactory performance using capillary scale columns. On-column focusing results from generating transient conditions at the head of the column that lead to high solute retention. Solvent-based on-column focusing is a well-known approach to achieve this. Temperature-assisted on-column focusing (TASF) can also be effective. TASF improves focusing by cooling a short segment of the column inlet to a temperature that is lower than the column temperature during the injection and then rapidly heating the focusing segment to the match the column temperature. A troublesome feature of an earlier implementation of TASF was the need to leave the capillary column unpacked in that portion of the column inside the fitting connecting it to the injection valve. We have overcome that problem in this work by packing the head of the column with solid silica spheres. In addition, technical improvements to the TASF instrumentation include: selection of a more powerful thermo-electric cooler to create faster temperature changes and electronic control for easy incorporation into conventional capillary instruments. Used in conjunction with solvent-based focusing and with isocratic elution, volumes of paraben samples (esters of p-hydroxybenzoic acid) up to 4.5-times the column liquid volume can be injected without significant bandspreading due to volume overload. Interestingly, the shapes of the peaks from the lowest volume injections that we can make, 30 nL, are improved when using TASF. TASF is very effective at reducing the detrimental effects of precolumn dispersion using isocratic elution. Finally, we show that TASF can be used to focus the neuropeptide galanin in a sample solvent with elution strength stronger than the mobile phase. Here, the stronger solvent is necessitated by the need to prevent peptide adsorption prior to and during analysis. PMID:26091787

  14. How to Avoid Fluid Overload

    PubMed Central

    Ogbu, Ogbonna C.; Murphy, David J.; Martin, Greg S.

    2015-01-01

    Purpose of the review This review highlights recent evidence describing the outcomes associated with fluid overload in critically ill patients and provides an overview of fluid management strategies aimed at preventing fluid overload during the resuscitation of patients with shock. Recent findings Fluid overload is a common complication of fluid resuscitation and is associated with increased hospital costs, morbidity and mortality. Summary Fluid management goals differ during the resuscitation, optimization, stabilization and evacuation phases of fluid resuscitation. To prevent fluid overload, strategies that reduce excessive fluid infusions and emphasize the removal of accumulated fluids should be implemented. PMID:26103147

  15. Helical computerized tomography and NT-proBNP for screening of right ventricular overload on admission and at long term follow-up of acute pulmonary embolism

    PubMed Central

    2012-01-01

    Background Right ventricular dysfunction (RVD) in acute pulmonary embolism (APE) can be assessed with helical computerized tomography (CT) and transthoracic echocardiography (TTE). Signs of RVD and elevated natriuretic peptides like NT-proBNP and cardiac troponin (TnT) are associated with increased risk of mortality. However, the prognostic role of both initial diagnostic strategy and the use of NT-proBNP and TnT for screening for long-term probability of RVD remains unknown. The aim of the study was to determine the role of helical CT and NT-proBNP in detection of RVD in the acute phase. In addition, the value of NT-proBNP for ruling out RVD at long-term follow-up was assessed. Methods Sixty-three non-high risk APE patients were studied. RVD was assessed at admission in the emergency department by CT and TTE, and both NT-proBNP and TnT samples were taken. These, excepting CT, were repeated seven months later. Results At admission RVD was detected by CT in 37 (59 %) patients. RVD in CT correlated strongly with RVD in TTE (p < 0.0001). NT-proBNP was elevated (≥ 350 ng/l) in 32 (86 %) patients with RVD but in only seven (27 %) patients without RVD (p < 0.0001). All the patients survived until the 7-month follow-up. TTE showed persistent RVD in 6 of 63 (10 %) patients who all had RVD in CT at admission. All of them had elevated NT-proBNP levels in the follow-up compared with 5 (9 %) of patients without RVD (p < 0.0001). Conclusions TTE does not confer further benefit when helical CT is used for screening for RVD in non-high risk APE. All the patients who were found to have RVD in TTE at seven months follow-up had had RVD in the acute phase CT as well. Thus, patients without RVD in diagnostic CT do not seem to require further routine follow-up to screen for RVD later. On the other hand, persistent RVD and thus need for TTE control can be ruled out by assessment of NT-proBNP at follow-up. A follow-up protocol based on these findings is suggested. PMID:22559861

  16. The Mythology of Information Overload.

    ERIC Educational Resources Information Center

    Tidline, Tonyia J.

    1999-01-01

    Combines ideas from mythology, folklore, and library and information science to conclude that information overload is a myth of modern culture. Reports results of a pilot project intended to describe information overload experienced by a particular folk group composed of future library and information professionals. (Author/LRW)

  17. Phase II trial of standard versus increased transfusion volume in Ugandan children with acute severe anemia

    PubMed Central

    2014-01-01

    Background Severe anemia (SA, hemoglobin <6 g/dl) is a leading cause of pediatric hospital admission in Africa, with significant in-hospital mortality. The underlying etiology is often infectious, but specific pathogens are rarely identified. Guidelines developed to encourage rational blood use recommend a standard volume of whole blood (20 ml/kg) for transfusion, but this is commonly associated with a frequent need for repeat transfusion and poor outcome. Evidence is lacking on what hemoglobin threshold criteria for intervention and volume are associated with the optimal survival outcomes. Methods We evaluated the safety and efficacy of a higher volume of whole blood (30 ml/kg; Tx30: n = 78) against the standard volume (20 ml/kg; Tx20: n = 82) in Ugandan children (median age 36 months (interquartile range (IQR) 13 to 53)) for 24-hour anemia correction (hemoglobin >6 g/dl: primary outcome) and 28-day survival. Results Median admission hemoglobin was 4.2 g/dl (IQR 3.1 to 4.9). Initial volume received followed the randomization strategy in 155 (97%) patients. By 24-hours, 70 (90%) children in the Tx30 arm had corrected SA compared to 61 (74%) in the Tx20 arm; cause-specific hazard ratio = 1.54 (95% confidence interval 1.09 to 2.18, P = 0.01). From admission to day 28 there was a greater hemoglobin increase from enrollment in Tx30 (global P <0.0001). Serious adverse events included one non-fatal allergic reaction and one death in the Tx30 arm. There were six deaths in the Tx20 arm (P = 0.12); three deaths were adjudicated as possibly related to transfusion, but none secondary to volume overload. Conclusion A higher initial transfusion volume prescribed at hospital admission was safe and resulted in an accelerated hematological recovery in Ugandan children with SA. Future testing in a large, pragmatic clinical trial to establish the effect on short and longer-term survival is warranted. Trial registration ClinicalTrials.Gov identifier: NCT01461590

  18. The Utility of 3D Left Atrial Volume and Mitral Flow Velocities as Guides for Acute Volume Resuscitation

    PubMed Central

    Santosa, Claudia M.; Rose, David D.; Fleming, Neal W.

    2015-01-01

    Left ventricular end-diastolic pressure (LVEDP) is the foundation of cardiac function assessment. Because of difficulties and risks associated with its direct measurement, correlates of LVEDP derived by pulmonary artery (PA) catheterization or transesophageal echocardiography (TEE) are commonly adopted. TEE has the advantage of being less invasive; however TEE-based estimation of LVEDP using correlates such as left ventricular end-diastolic volume (LVEDV) has technical difficulties that limit its clinical usefulness. Using intraoperative acute normovolemic hemodilution (ANH) as a controlled hemorrhagic model, we examined various mitral flow parameters and three-dimensional reconstructions of left atrial volume as surrogates of LVEDP. Our results demonstrate that peak E wave velocity and left atrial end-diastolic volume (LAEDV) correlated with known changes in intravascular volume associated with ANH. Although left atrial volumetric analysis was done offline in our study, recent advances in echocardiographic software may allow for continuous display and real-time calculation of LAEDV. Along with the ease and reproducibility of acquiring Doppler images of flow across the mitral valve, these two correlates of LVEDP may justify a more widespread use of TEE to optimize intraoperative fluid management. The clinical applicability of peak E wave velocity and LAEDV still needs to be validated during uncontrolled resuscitation. PMID:26236733

  19. Hormonal and electrolyte responses to acute isohemic volume expansion in unanesthetized rats

    NASA Technical Reports Server (NTRS)

    Chenault, V. M.; Morris, M.; Lynch, C. D.; Maultsby, S. J.; Hutchins, P. M.

    1993-01-01

    This study was undertaken to explore the time course of the metabolic response to isohemic blood volume expansion (30%) in normotensive, unanesthetized Sprague-Dawley rats. Whole blood, drawn from a femoral artery catheter of conscious donor rats, was infused into the jugular vein of recipient rats. Blood samples were drawn from a carotid artery of recipient rats at time points beginning immediately post-volume expansion (IPVE) up through 5 days post-volume expansion (PVE). To characterize the attendant compensatory mechanisms, the plasma concentrations of electrolytes and fluid regulatory hormones were determined. Hematocrit began to raise IPVE and was significantly elevated above control IPVE 20, 30, 40, 60, and 90 min, and 2, 4, 6, 8, 12, and 24 hr PVE. Consistent with our current understanding of the hormonal response to excess volume, atrial natriuretic factor was significantly increased above the prevolume expansion (control) values 0-30 min PVE. Surprisingly, plasma aldosterone levels were significantly increased above control at 20 and 30 min and 6 hr PVE, whereas plasma renin activity was significantly decreased 30-40 min PVE. Plasma sodium was not changed from control values except for a significant increase at 6 hr post-volume expansion. Plasma potassium, osmolality, and arginine vasopressin levels were not altered by the volume expansion. These studies delineate the physiologic time scheme operative in the regulation of fluid volume during acute ischemic volume expansion.

  20. Diagnostic importance of admission platelet volume indices in patients with acute chest pain suggesting acute coronary syndrome

    PubMed Central

    Dehghani, Mohammad Reza; Taghipour-Sani, Leila; Rezaei, Yousef; Rostami, Rahim

    2014-01-01

    Objective Acute coronary syndrome (ACS) is a challenging issue in cardiovascular medicine. Given platelet role in atherothrombosis, we sought to determine whether platelet indices can be used as diagnostic tests for patients who suffered from an acute chest discomfort. Methods We prospectively enrolled 862 patients with an acute chest pain and 184 healthy matched controls. They were divided into four groups: 184 controls, 249 of non-ACS, 421 of unstable angina (UA), and 192 of myocardial infarction (MI) cases. Blood samples were collected at admission to the emergency department for routine hematologic tests. Results The mean platelet volume (MPV), platelet distribution width (PDW), and platelet large cell ratio (P-LCR) were significantly greater in patients with MI compared with those of non-ACS or control subjects. Negative and significant correlations existed between MPV, PDW, and P-LCR values and platelet count (P < 0.001). Receiver operating characteristic (ROC) curves showed that the MPV, PDW, and P-LCR with cut-off values of 9.15 fL, 11.35 fL, and 20.25% and with area under the curves of 0.563, 0.557, and 0.560, respectively, detected MI patients among those who had chest discomfort. The sensitivities and specificities were found to be 72% and 40%, 73% and 37%, and 68% and 44% for MPV, PDW, and P-LCR, respectively. Conclusion An elevated admission MPV, PDW, and P-LCR may be of benefit to detect chest pain resulting in MI from that of non-cardiac one, and also for risk stratification of patients who suffered from an acute chest discomfort. PMID:25634396

  1. Role of angiotensin II in the antinatriuresis that follows acute volume depletion.

    PubMed

    Gamba, G; Pedraza-Chaverrí, J; Cervera, J; Cruz, C; Hernández-Pando, R; Peña, J C

    1992-01-01

    The aim of this study was to examine the contribution of the renin angiotensin system to the antinatriuresis that follows acute volume depletion. Four groups of six dogs each were studied. The first group was exposed to saline expansion (8% body weight) (SE). The second group was exposed to acute volume depletion (2% body weight) followed in one hour by saline expansion (AVD). The third and fourth groups were similar but in dogs treated with high doses of captopril (SE + C and AVD + C). Dogs were anesthetized with phenobarbital. Control measurements were made for 30 minutes before and 60 minutes during saline expansion. Glomerular filtration rate (inulin), renal blood flow (para-aminohippuric acid) and mean arterial pressure were similar in the four groups during the experiment. The increase in fractional sodium excretion from the control period to the end of saline expansion was in the SE group from 0.6 +/- 0.2 to 6.4 +/- 1% and in the SE + C group from 1.1 +/- 0.3 to 8.5 +/- 1.3%. In contrast, in the AVD group it only rose from 0.8 +/- 0.2 to 3.5 +/- 0.7% and in the AVD + C group from 1.3 +/- 0.4 to 4.1 +/- 0.6%. Therefore, the increment in sodium excretion during saline expansion was significantly lower in dogs exposed to acute volume depletion, independent of the treatment with captopril. The blunted natriuresis cannot be explained by differences in GFR, RBF or MAP. These results suggest that renin angiotensin system is not the responsible agent of the sodium retention that follows acute volume depletion. PMID:1488579

  2. Ozone risk assessment utilities (ORAMUS) user's manual and tutorial : Volume 1, Acute health endpoints.

    SciTech Connect

    Clemmons, M. A.; Jusko, M. J.; Whitfield, R. G.

    1998-12-16

    The primary purpose of this manual is to provide instructions on how to install and use the ORAMUS (Ozone Risk AssessMent UtilitieS) software. ORAMUS is a DOS-based software system that allows you to calculate and view risk estimates for health effects attributable to short- and long-term exposure to tropospheric ozone. The system combines exposure estimates with exposure-response relationships and then calculates and displays estimates of the overall risk in the form of probability distributions. ORAMUS allows you to select from three basic models: headcount risk, benchmark risk, and hospital admissions. It calculates a wide range of risk results for 27 air quality scenarios, 9 urban areas, 33 acute health endpoints, 4 chronic health endpoints, and 3 populations of interest. This manual is a tutorial designed to guide you through a series of steps that will familiarize you with the features of the system. The manual consists of two volumes. Volume 1 addresses acute health endpoints, and Volume 2 covers chronic health endpoints. Acute results were used during the National Ambient Air Quality Standards review process for ozone. Chronic results were not used.

  3. Protect motors with solid-state overloads

    SciTech Connect

    Forsell, K.A. )

    1993-03-01

    Magnetic motor starters that rely on bimetal or melting alloy overload protection do not provide the flexibility of solid-state overload technology. The point is best illustrated by the number of different overload relay trip curves that describe tripping time as a function of motor current. Solid-state overloads have a trip curve for a cold start with three-phase current, and a family of trip curves for three-phase conditions where the overload and motor are already warm. An overload relay can also be described by its single-phase trip-time curves for cold and warm initial states. All thermal overloads have single phase trip curves that are similar in shape to their three-phase curves. Slower response to phase loss for motor loads less than locked rotor is inherent in thermal overload relay design. The paper describes the power source problem; single-phase problems; thermal overloads versus solid state; and thermal NEMA overload.

  4. [Fat overload syndrome].

    PubMed

    Picon, J; Carsin, A; Baravalle-Einaudi, M; Coste, M-E; Wasier, A-P; Stremler-Le Bel, N; Bosdure, E; Dubus, J-C

    2016-08-01

    We report the case of a 21-month-old child suffering from pulmonary fibrosis, who presented with acute respiratory distress and liver damage, due to an accidental overdose of intravenous lipid emulsion. This poisoning is a rare entity, whose potential severity and almost exclusive iatrogenic effect deserve to be remembered. PMID:27369104

  5. Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

    SciTech Connect

    Wagner, Marlies; Kyriakou, Yiannis; Mesnil de Rochemont, Richard du; Singer, Oliver C.; Berkefeld, Joachim

    2013-08-01

    PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.

  6. Calculation of the Residual Blood Volume after Acute, Non-Ongoing Hemorrhage Using Serial Hematocrit Measurements and the Volume of Isotonic Fluid Infused: Theoretical Hypothesis Generating Study.

    PubMed

    Oh, Won Sup; Chon, Sung-Bin

    2016-05-01

    Fluid resuscitation, hemostasis, and transfusion is essential in care of hemorrhagic shock. Although estimation of the residual blood volume is crucial, the standard measuring methods are impractical or unsafe. Vital signs, central venous or pulmonary artery pressures are inaccurate. We hypothesized that the residual blood volume for acute, non-ongoing hemorrhage was calculable using serial hematocrit measurements and the volume of isotonic solution infused. Blood volume is the sum of volumes of red blood cells and plasma. For acute, non-ongoing hemorrhage, red blood cell volume would not change. A certain portion of the isotonic fluid would increase plasma volume. Mathematically, we suggest that the residual blood volume after acute, non-ongoing hemorrhage might be calculated as 0·25N/[(Hct1/Hct2)-1], where Hct1 and Hct2 are the initial and subsequent hematocrits, respectively, and N is the volume of isotonic solution infused. In vivo validation and modification is needed before clinical application of this model. PMID:27134507

  7. Calculation of the Residual Blood Volume after Acute, Non-Ongoing Hemorrhage Using Serial Hematocrit Measurements and the Volume of Isotonic Fluid Infused: Theoretical Hypothesis Generating Study

    PubMed Central

    2016-01-01

    Fluid resuscitation, hemostasis, and transfusion is essential in care of hemorrhagic shock. Although estimation of the residual blood volume is crucial, the standard measuring methods are impractical or unsafe. Vital signs, central venous or pulmonary artery pressures are inaccurate. We hypothesized that the residual blood volume for acute, non-ongoing hemorrhage was calculable using serial hematocrit measurements and the volume of isotonic solution infused. Blood volume is the sum of volumes of red blood cells and plasma. For acute, non-ongoing hemorrhage, red blood cell volume would not change. A certain portion of the isotonic fluid would increase plasma volume. Mathematically, we suggest that the residual blood volume after acute, non-ongoing hemorrhage might be calculated as 0·25N/[(Hct1/Hct2)–1], where Hct1 and Hct2 are the initial and subsequent hematocrits, respectively, and N is the volume of isotonic solution infused. In vivo validation and modification is needed before clinical application of this model. PMID:27134507

  8. Acute changes in forearm venous volume and tone using radionuclide plethysmography

    SciTech Connect

    Manyari, D.E.; Malkinson, T.J.; Robinson, V.; Smith, E.R.; Cooper, K.E.

    1988-10-01

    In this investigation blood pool scintigraphy was validated as a method to study acute changes in human forearm veins. Changes in regional forearm vascular volume (capacity) and the occluding pressure-volume (P-V) relationship induced by sublingual nifedipine (NIF) and nitroglycerin (GTN) were recorded in 16 patients with simultaneous data collection by the radionuclide and the mercury-in-rubber strain-gauge techniques. The standard error of estimate (Syx) between successive control measurements using the radionuclide method was 3.1% compared with 3.2% for the strain-gauge method. The venous P-V curves were highly reproducible using both techniques. Strain gauge and radionuclide measurements of acute changes in forearm venous volume correlated well (r = 0.86; Syx = 7%, n = 156). After 20 mg of NIF or 0.6 mg of GTN, mean heart rate increased from 71 +/- 10 to 77 +/- 9 and from 68 +/- 10 to 75 +/- 11 beats/min, respectively, and group systolic blood pressure decreased from 128 +/- 22 to 120 +/- 19 and from 136 +/- 18 to 126 +/- 23 mmHg, respectively (P less than 0.05). At venous occluding pressures of 0 and 30 mmHg, the forearm vascular volume did not change after NIF (2 +/- 4 and -1 +/- 4%; P greater than 0.05), whereas it increased after GTN (8 +/- 5 and 12 +/- 7%; P less than 0.001). The forearm venous P-V relationship did not change after NIF, whereas a significant rightward shift (venodilation, with an increase in unstressed volume) occurred after GTN.

  9. Limited Reliability of CT perfusion acute infarct volume measurements compared to DWI in anterior circulation stroke

    PubMed Central

    Schaefer, Pamela W.; Souza, Leticia; Kamalian, Shervin; Hirsch, Joshua A.; Yoo, Albert J.; Kamalian, Shahmir; Gonzalez, R. Gilberto; Lev, Michael H.

    2015-01-01

    Background and Purpose DWI can reliably identify critically ischemic tissue (CIT) shortly after stroke onset. We tested if thresholded CT-CBF and CT-CBV maps are sufficiently accurate to substitute for DWI for estimating CIT volume. Methods Ischemic volumes of 55 patients with acute anterior circulation stroke were assessed on DWI by visual segmentation, and CT-CBF and CT-CBV with segmentation using 15% and 30% thresholds, respectively. The contrast-to-noise ratios (CNR) of ischemic regions on the DWI and CTP images were measured. Correlation and Bland-Altman analyses were used to assess reliability of CTP. Results Mean CNRs for DWI, CT-CBF and CT-CBV were 4.3, 0.9 and 0.4, respectively. CTP and DWI lesion volumes were highly correlated (R2=0.87 for CT-CBF; R2=0.83 for CT-CBV; p<0.001). Bland-Altman analyses revealed little systemic bias (−2.6 ml) but high measurement variability (95% CI ±56.7 ml) between mean CT-CBF and DWI lesion volumes, and systemic bias (−26 ml) and high measurement variability (95% CI ±64.0 ml) between mean CT-CBV and DWI lesion volumes. A simulated treatment study demonstrated that using CTP-CBF instead of DWI for detecting a statistically significant effect would require at least twice as many patients. Conclusions The poor CNRs of CT-CBV and CT-CBF compared to DWI result in large measurement error making it problematic to substitute CTP for DWI in selecting individual acute stroke patients for treatment. CTP could be used for treatment studies of patient groups, but the number of patients needed to identify a significant effect is much higher than if DWI is used. PMID:25550366

  10. The role of mean platelet volume predicting acute exacerbations of cystic fibrosis in children

    PubMed Central

    Uysal, Pιnar; Tuncel, Tuba; Olmez, Duygu; Babayigit, Arzu; Karaman, Ozkan; Uzuner, Nevin

    2011-01-01

    OBJECTIVE: The aim of this study is to evaluate the relationship between acute exacerbations and the mean platelet volume (MPV) trend in children with cystic fibrosis (CF), to predict the exacerbations. METHODS: A total of 46 children with CF and 37 healthy children were enrolled in the study. White blood cell count (WBC), hemoglobin level, platelet count, mean platelet volume (MPV), and mean corpuscular volume (MCV) were retrospectively recorded. RESULTS: Our study population consisted of 25 (54.3%) males and 21 (45.7%) females with CF and 20 (54.0%) males and 17 (46.0%) females in the healthy control group. The mean age of the CF patients was 6.32 ± 4.9 years and that of the healthy subjects was 7.02 ± 3.15 years. In the acute exacerbation period of CF, the MPV values were lower and WBC and platelet counts were higher than those in the healthy controls (P = 0.00, P = 0.00, P = 0.00, respectively). Besides, in acute exacerbation, the MPV values were lower and the WBC count was higher than the values in the non-exacerbation period (P 0= 0.01, P = 0.00, respectively). In the non-exacerbation period MPV was lower and platelet count was higher when compared to healthy subjects (P = 0.02, P = 0.04, respectively). CONCLUSION: This study suggests that MPV might be used as a simple, cost effective, diagnostic, predictive indicator for platelet activation in pediatric CF patients related to chronic inflammation, which might be helpful to discriminate or estimate exacerbations. PMID:21977069

  11. The function of the left anterior temporal pole: evidence from acute stroke and infarct volume

    PubMed Central

    Tsapkini, Kyrana; Frangakis, Constantine E.

    2011-01-01

    The role of the anterior temporal lobes in cognition and language has been much debated in the literature over the last few years. Most prevailing theories argue for an important role of the anterior temporal lobe as a semantic hub or a place for the representation of unique entities such as proper names of peoples and places. Lately, a few studies have investigated the role of the most anterior part of the left anterior temporal lobe, the left temporal pole in particular, and argued that the left anterior temporal pole is the area responsible for mapping meaning on to sound through evidence from tasks such as object naming. However, another recent study indicates that bilateral anterior temporal damage is required to cause a clinically significant semantic impairment. In the present study, we tested these hypotheses by evaluating patients with acute stroke before reorganization of structure–function relationships. We compared a group of 20 patients with acute stroke with anterior temporal pole damage to a group of 28 without anterior temporal pole damage matched for infarct volume. We calculated the average percent error in auditory comprehension and naming tasks as a function of infarct volume using a non-parametric regression method. We found that infarct volume was the only predictive variable in the production of semantic errors in both auditory comprehension and object naming tasks. This finding favours the hypothesis that left unilateral anterior temporal pole lesions, even acutely, are unlikely to cause significant deficits in mapping meaning to sound by themselves, although they contribute to networks underlying both naming and comprehension of objects. Therefore, the anterior temporal lobe may be a semantic hub for object meaning, but its role must be represented bilaterally and perhaps redundantly. PMID:21685458

  12. The effect of acute and chronic hypoxia on thoracic gas volume in anaesthetized rats.

    PubMed Central

    Barer, G R; Herget, J; Sloan, P J; Suggett, A J

    1978-01-01

    1. Thoracic gas volume at end expiration (functional residual capacity, FRC) was measured in chronically and acutely hypoxic anaesthetized rats by a plethysmograph method. 2. FRC, measured during air breathing, was 34-62% larger in rats which had been kept in an environmental chamber in 8, 10 or 12% O2 for 3 weeks than in littermate controls. FRC returned to normal after the rats had returned to air for 9 days. There was no constant difference in the pattern of breathing between control and chronically hypoxic rats. 3. Pressure-volume curves measured post mortem showed no difference in the volume of the lung at 25 cm H2O pressure or in the compliance of the lung between chronically hypoxic and control rats. Thus there was no gross mechanical change in the lung to account for the increase in FRC. 4. Acute hypoxia caused by breathing 12% O2 increased FRC in control but not in chronically hypoxic rats. The increase in FRC in control rats was abolished by combined blockade of the vagus nerves and carotid bodies (with procaine) but not by vagal blockade alone. 5. The combined vagal and carotid body blockade reduced FRC significantly in rats which had been in 10% O2 for 3 days but not in those which had been in 10% O2 for 21 days. 6. Lung area measured from radiographs was not reduced by a muscle relaxant in chronically hypoxic rats. Electromyograms from anterior intercostal muscles and the diaphragm showed no electrical activity in expiration in chronically hypoxic rats which might indicate an active muscular basis for their increased FRC. However when FRC was raised by acute hypoxia in control animals there was also no increase in electrical activity in expiration which could have explained their increase in lung volume. 7. We concluded that the increase in FRC during acute hypoxia in control rats was probably due to a reflex from the carotid body. The increase in FRC in chronically hypoxic rats, which was present while they breathed air, may have had an active

  13. Avoiding Program-Induced Cumulative Overload (PICO).

    PubMed

    Orr, Robin; Knapik, Joseph J; Pope, Rodney

    2016-01-01

    This article defines the concept of program-induced cumulative overload (PICO), provides examples, and advises ways to mitigate the adverse effects. PICO is the excessive cumulative physical workload that can be imparted to military personnel by a military training program with an embedded physical training component. PICO can be acute (accumulating within a single day) or chronic (accumulating across the entirety of the program) and results in adverse outcomes for affected personnel, including detrimental fatigue, performance degradation, injuries, or illness. Strategies to mitigate PICO include focusing administration and logistic practices during the development and ongoing management of a trainee program and implementing known musculoskeletal injury prevention strategies. More training is not always better, and trainers need to consider the total amount of physical activity that military personnel experience across both operational training and physical training if PICO is to be mitigated. PMID:27450610

  14. Effects of acute physical exercise on hepatocyte volume and function in rat.

    PubMed

    Latour, M G; Brault, A; Huet, P M; Lavoie, J M

    1999-05-01

    The goal of the present experiment was to measure the volume of the different compartments in liver of exercised rats and to get some insights into the appropriate working of the hepatic function following exercise. Hence, livers from male rats were isolated and perfused after treadmill exercise or rest. This procedure was performed on rats that were overnight semifasted (50% food restriction) or well fed. To evaluate the hepatocyte cell volume, the multiple-indicator dilution curve technique was used after 40 min of perfusion. Radioactive tracers for red blood cells, sucrose, and water were used to measure liver vascular space, liver interstitial space, and water cellular space, respectively. The hepatocyte function was assessed by taurocholate and propanolol clearance. Oxygen consumption, intrahepatic resistance, bile secretion, and lactate dehydrogenase release estimated liver viability. Liver viability and hepatocyte function were not changed following exercise either in the fed or in the semifasted animals. As expected, liver glycogen levels were significantly (P < 0.01) reduced in the food-restricted rats. Consequently, liver glycogen levels following exercise were decreased significantly (P < 0.01) only in the fed rats. Despite this, exercise decreased the hepatocyte water space in both food-restricted and fed groups ( approximately 15%; P < 0.01) without altering the sinusoidal and interstitial space. The present data show that acute exercise decreased the hepatocyte volume and that this volume change is not entirely linked to a decrease in hepatic glycogen level. PMID:10233015

  15. Effects of iron overload on the immune system.

    PubMed

    Walker, E M; Walker, S M

    2000-10-01

    Iron and its binding proteins have immunoregulatory properties, and shifting of immunoregulatory balances by iron excess or deficiency may produce severe, deleterious physiological effects. Effects of iron overload include decreased antibody-mediated and mitogen-stimulated phagocytosis by monocytes and macrophages, alterations in T-lymphocyte subsets, and modification of lymphocyte distribution in different compartments of the immune system. The importance of iron in regulating the expression of T-lymphocyte cell surface markers, influencing the expansion of different T-cell subsets, and affecting immune cell functions can be demonstrated in vitro and in vivo. The poor ability of lymphocytes to sequester excess iron in ferritin may help to explain the immune system abnormalities in iron-overloaded patients. Iron overload as seen in hereditary hemochromatosis patients enhances suppressor T-cell (CD8) numbers and activity, decreases the proliferative capacity, numbers, and activity of helper T cells (CD4) with increases in CD8/CD4 ratios, impairs the generation of cytotoxic T cells, and alters immunoglobulin secretion when compared to treated hereditary hemochromatosis patients or controls. A correlation has recently been found between low CD8+ lymphocyte numbers, liver damage associated with HCV positivity, and severity of iron overload in beta-thalassemia major patients. Iron overload, with its associated increases of serum iron levels and transferrin saturation, may cause a poor response to interferon therapy. Iron overload with hyperferremia is associated with suppressed functions of the complement system (classic or alternative types). High plasma ferritin content in patients with chronic, diffuse diseases of the liver (cirrhosis, chronic hepatitis), beta-thalassemia major, dyserythropoiesis, and hereditary hemochromatosis may induce the development of anti-ferritin antibodies with the production of circulating immune complexes. Increased body stores of iron in

  16. Titration of tidal volume and induced hypercapnia in acute respiratory distress syndrome.

    PubMed

    Roupie, E; Dambrosio, M; Servillo, G; Mentec, H; el Atrous, S; Beydon, L; Brun-Buisson, C; Lemaire, F; Brochard, L

    1995-07-01

    Mechanical ventilation may promote overdistension-induced pulmonary lesions in patients with acute respiratory distress syndrome (ARDS). The static pressure-volume (P-V) curve of the respiratory system can be used to determine the lung volume and corresponding static airway pressure at which lung compliance begins to diminish (the upper inflection point, or UIP). This fall in compliance may indicate overdistension of lung units. We prospectively studied 42 patients receiving mechanical ventilation with an FIO2 of 0.5 or more for at least 24 h. According to the Lung Injury Score (LIS), 25 patients were classified as having ARDS (LIS > 2.5), while 17 patients constituted a non-ARDS control group. The P-V curve was obtained every 2 d. Mechanical ventilation initially used standard settings (volume-control mode, a positive end-expiratory pressure [PEEP] adjusted to the lower inflection point on the P-V curve, and a tidal volume [VT] of 10 ml/kg). The end-inspiratory plateau pressure (Pplat) was compared to the UIP, and VT was lowered when the Pplat was above the UIP. In the range of lung volume studied on the P-V curves (up to 1600 ml), a UIP could be shown in only one control patient (at 23 cm H2O). By contrast, a UIP was present on the P-V curve obtained from all patients with ARDS, corresponding to a mean airway pressure of 26 +/- 6 cm H2O, a lung volume of 850 +/- 200 ml above functional residual capacity and 610 +/- 235 ml above PEEP.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7599810

  17. Evaluation of reduced sediment volume procedures for acute toxicity tests using the estuarine amphipod Leptocheirus plumulosus.

    PubMed

    Stanley, Jacob K; Kennedy, Alan J; Farrar, J Daniel; Mount, David R; Steevens, Jeffery A

    2010-12-01

    The volume of sediment required to perform a sediment toxicity bioassay is a major driver of the overall cost associated with that bioassay. Sediment volume affects bioassay cost because of sediment collection, transportation, storage, and disposal costs as well as labor costs associated with organism recovery at the conclusion of the exposure. The objective of the current study was to evaluate reduced sediment volume versions of the standard U.S. Environmental Protection Agency (U.S. EPA) 10-d acute Leptocheirus plumulosus method that uses a beaker size of 1,000 ml and 20 organisms. The test design used evaluated the effects of beaker size (250 and 100 ml) and associated sediment volume (75 and 30 ml, respectively) as well as organism loading density (10 and 20 organisms) on test endpoint responsiveness relative to the standard 10-d test method. These comparisons were completed with three different types of contaminated sediments: a field-collected polycyclic aromatic hydrocarbon (PAH)-contaminated sediment, a lead-spiked control sediment, and a control sediment spiked with mineral oil. Assessment criteria included test endpoint sensitivity, endpoint consistency, statistical power, water quality, and logistical assessments. Results indicate that the current U.S. EPA method is preferable to the reduced sediment volume methods we assessed, but that a 250-ml beaker/10 organism experimental design is of comparable utility and may be advantageous when reduced sediment volumes are desirable because of high contaminant (spiking studies) or sediment disposal costs. In addition, the results of the current study provide toxicity reference values for PAHs, lead, and an oil surrogate for petroleum hydrocarbons. PMID:20890914

  18. Acute Heart Failure Treatment.

    PubMed

    Levy, Phillip D; Bellou, Abdel

    2013-06-01

    Dyspnea is the predominant symptom for patients with acute heart failure and initial treatment is largely directed towards the alleviation of this. Contrary to conventional belief, not all patients present with fluid overload and the approach to management is rapidly evolving from a solitary focus on diuresis to one that more accurately reflects the complex interplay of underlying cardiac dysfunction and acute precipitant. Effective treatment thus requires an understanding of divergent patient profiles and an appreciation of various therapeutic options for targeted patient stabilization. The key principle within this paradigm is directed management that aims to diminish the work of breathing through situation appropriate ventillatory support, volume reduction and hemodynamic improvement. With such an approach, clinicians can more efficiently address respiratory discomfort while reducing the likelihood of avoidable harm. PMID:24223323

  19. How to Survive Data Overload

    ERIC Educational Resources Information Center

    Thomas, Ronald S.

    2006-01-01

    Suffering from data overload? Many schools are. Although schools have lacked sufficient student achievement data to make good instructional decisions in the past, many are now snowed under with data. They are data rich but analysis poor. How can content, vertical, or interdisciplinary school teams make sense of all their data? How can principals…

  20. Electrometer Amplifier With Overload Protection

    NASA Technical Reports Server (NTRS)

    Woeller, F. H.; Alexander, R.

    1986-01-01

    Circuit features low noise, input offset, and high linearity. Input preamplifier includes input-overload protection and nulling circuit to subtract dc offset from output. Prototype dc amplifier designed for use with ion detector has features desirable in general laboratory and field instrumentation.

  1. [Transfusion-associated circulatory overload].

    PubMed

    Ozier, Y; Mouquet, F; Rieux, C; Mertes, P-M; Muller, J-Y; Caldani, C; Boudjedir, K; Carlier, M

    2012-11-01

    A working group of the French National Hemovigilance Committee has been in charge of heightening awareness of Transfusion-Associated Circulatory Overload (TACO) among physicians and nurses. This multidisciplinary group has produced the present document that focuses on epidemiological data provided by the French haemovigilance network, physiopathology, diagnosis, treatment and specific actions that could prevent or minimize the risk of TACO. PMID:23039960

  2. Increased tubuloglomerular feed-back mediated suppression of glomerular filtration during acute volume expansion in rats.

    PubMed Central

    Davis, J M; Häberle, D A; Kawata, T; Schmitt, E; Takabatake, T; Wohlfeil, S

    1988-01-01

    1. Volume expansion is currently believed to change the intrinsic properties of the juxtaglomerular apparatus such that the sensitivity of the tubuloglomerular feedback (TGF) mechanism is reduced, thus allowing glomerular filtration rate, and hence salt and water excretion, to rise. Recent studies conflict with this view and indeed the older literature reveals that the rise in glomerular filtration rate (GFR) under these conditions is far more modest than would be expected if TGF control were eliminated. 2. To investigate this problem, TGF control of filtration rate was examined by measuring single-nephron glomerular filtration rate (SNGFR) during loop of Henle perfusion at varying rates in rats under control conditions, after acute, moderate (4% of body weight), iso-oncotic volume expansion and in rats treated with antibodies to atrial natriuretic peptide (ANP) prior to the acute volume expansion. 3. With TGF control of filtration interrupted by filtrate collection from the proximal tubule, SNGFR in the expanded rats was massively increased compared with controls, although SNGFR measured in the distal tubule, and hence with TGF control intact, was only modestly increased, as was whole-kidney filtration rate. Loop perfusion at increasing rates up to 30 nl min-1 progressively decreased SNGFR in controls, and in the expanded rats the range over which control was exerted extended up to 60-80 nl min-1. For changes in loop flow around the spontaneous operating point, the sensitivity of the TGF mechanism, defined as delta SNGFR/delta loop flow, was similar in both groups. Treatment of rats with ANP antibodies prior to volume expansion substantially blunted the changes in renal salt and water excretion and the increase in SNGFR seen in the absence of loop perfusion. 4. These results are not consistent with a diminution of TGF function after volume expansion, rather with an enhancement. The latter is best accounted for by vasodilation of preglomerular resistance vessels on

  3. Bioimpedance can solve problems of fluid overload.

    PubMed

    Abbas, Samer R; Zhu, Fansan; Levin, Nathan W

    2015-03-01

    Bioimpedance (BI) techniques for measuring normal hydration status (NHS) can be generally classified as (1) by frequency as single frequency at 50 kHz, BI analysis, and multifrequency BI spectroscopy and (2) by method as whole body (wrist to ankle) measurement and calf BI spectroscopy. The aim of this article was to review current BI methods for clinical practice in patients with end-stage of kidney disease. BI vector analysis using whole-body single-frequency BI at 50 kHz may be useful for population studies to indicate a range of degree of fluid loading and of nutritional status. Whole body multifrequency BI spectroscopy is used to estimate extracellular (ECV), intracellular fluid volume, and total body water in dialysis patients. The whole-body BI model is used in the body composition monitor (BCM). The whole-body BI model is established with ECV, intracellular fluid volume, and body weight based on parameters from regression analysis in healthy subjects to calculate fluid overload in dialysis patients. Calf BI methods have been developed to measure NHS by 2 ways: (1) continuous measurement of the intradialytic resistance curve until flattening occurs; (2) calf normalized resistivity in the range of healthy subjects (18.5 × 10(-2) Ω m(3)/kg in male and 19.1 × 10(-2) Ω m(3)/kg in female). In general, for population studies, BI vector analysis or ECV/total body water may be useful; BCM is a commercially available device that can certainly guide volume reduction safely over time. For more exact measure of fluid overload, calf BI methods appear to be most accurate, but these are at present research tools. BI techniques are not only useful in assessing NHS but also in the study of nutrition and body composition. PMID:25556307

  4. Effect of an acute increase in central blood volume on cerebral hemodynamics.

    PubMed

    Ogoh, Shigehiko; Hirasawa, Ai; Raven, Peter B; Rebuffat, Thomas; Denise, Pierre; Lericollais, Romain; Sugawara, Jun; Normand, Hervé

    2015-10-15

    Systemic blood distribution is an important factor involved in regulating cerebral blood flow (CBF). However, the effect of an acute change in central blood volume (CBV) on CBF regulation remains unclear. To address our question, we sought to examine the CBF and systemic hemodynamic responses to microgravity during parabolic flight. Twelve healthy subjects were seated upright and exposed to microgravity during parabolic flight. During the brief periods of microgravity, mean arterial pressure was decreased (-26 ± 1%, P < 0.001), despite an increase in cardiac output (+21 ± 6%, P < 0.001). During microgravity, central arterial pulse pressure and estimated carotid sinus pressure increased rapidly. In addition, this increase in central arterial pulse pressure was associated with an arterial baroreflex-mediated decrease in heart rate (r = -0.888, P < 0.0001) and an increase in total vascular conductance (r = 0.711, P < 0.001). The middle cerebral artery mean blood velocity (MCA Vmean) remained unchanged throughout parabolic flight (P = 0.30). During microgravity the contribution of cardiac output to MCA Vmean was gradually reduced (P < 0.05), and its contribution was negatively correlated with an increase in total vascular conductance (r = -0.683, P < 0.0001). These findings suggest that the acute loading of the arterial and cardiopulmonary baroreceptors by increases in CBV during microgravity results in acute and marked systemic vasodilation. Furthermore, we conclude that this marked systemic vasodilation decreases the contribution of cardiac output to CBF. These findings suggest that the arterial and cardiopulmonary baroreflex-mediated peripheral vasodilation along with dynamic cerebral autoregulation counteracts a cerebral overperfusion, which otherwise would occur during acute increases in CBV. PMID:26310936

  5. Frequency of fluid overload and usefulness of bioimpedance in patients requiring intensive care for sepsis syndromes.

    PubMed

    Larsen, Timothy R; Singh, Gurbir; Velocci, Victor; Nasser, Mohamed; McCullough, Peter A

    2016-01-01

    Guideline-directed therapy for sepsis calls for early fluid resuscitation. Often patients receive large volumes of intravenous fluids. Bioimpedance vector analysis (BIVA) is a noninvasive technique useful for measuring total body water. In this prospective observational study, we enrolled 18 patients admitted to the intensive care unit for the treatment of sepsis syndromes. Laboratory data, clinical parameters, and BIVA were recorded daily. All but one patient experienced volume overload during the course of treatment. Two patients had >20 L of excess volume. Volume overload is clinically represented by tissue edema. Edema is not a benign condition, as it impairs tissue oxygenation, obstructs capillary blood flow, disrupts metabolite clearance, and alters cell-to-cell interactions. Specifically, volume overload has been shown to impair pulmonary, cardiac, and renal function. A positive fluid balance is a predictor of hospital mortality. As septic patients recover, volume excess should be aggressively treated with the use of targeted diuretics and renal replacement therapies if necessary. PMID:26722156

  6. Frequency of fluid overload and usefulness of bioimpedance in patients requiring intensive care for sepsis syndromes

    PubMed Central

    Singh, Gurbir; Velocci, Victor; Nasser, Mohamed; McCullough, Peter A.

    2016-01-01

    Guideline-directed therapy for sepsis calls for early fluid resuscitation. Often patients receive large volumes of intravenous fluids. Bioimpedance vector analysis (BIVA) is a noninvasive technique useful for measuring total body water. In this prospective observational study, we enrolled 18 patients admitted to the intensive care unit for the treatment of sepsis syndromes. Laboratory data, clinical parameters, and BIVA were recorded daily. All but one patient experienced volume overload during the course of treatment. Two patients had >20 L of excess volume. Volume overload is clinically represented by tissue edema. Edema is not a benign condition, as it impairs tissue oxygenation, obstructs capillary blood flow, disrupts metabolite clearance, and alters cell-to-cell interactions. Specifically, volume overload has been shown to impair pulmonary, cardiac, and renal function. A positive fluid balance is a predictor of hospital mortality. As septic patients recover, volume excess should be aggressively treated with the use of targeted diuretics and renal replacement therapies if necessary. PMID:26722156

  7. Association between i.v. thrombolysis volume and door-to-needle times in acute ischemic stroke.

    PubMed

    Groot, Adrien E; van Schaik, Ivo N; Visser, Marieke C; Nederkoorn, Paul J; Limburg, Martien; Aramideh, Majid; de Beer, Frank; Zwetsloot, Caspar P; Halkes, Patricia; de Kruijk, Jelle; Kruyt, Nyika D; van der Meulen, Willem; Spaander, Fianne; van der Ree, Taco; Kwa, Vincent I H; Van den Berg-Vos, Renske M; Roos, Yvo B; Coutinho, Jonathan M

    2016-04-01

    Centralization of intravenous thrombolysis (IVT) for acute ischemic stroke in high-volume centers is believed to improve the door-to-needle times (DNT), but limited data support this assumption. We examined the association between DNT and IVT volume in a large Dutch province. We identified consecutive patients treated with IVT between January 2009 and 2013. Based on annualized IVT volume, hospitals were categorized as low-volume (≤ 24), medium-volume (25-49) or high-volume (≥ 50). In logistic regression analysis, low-volume hospitals were used as reference category. Of 17,332 stroke patients from 11 participating hospitals, 1962 received IVT (11.3 %). We excluded 140 patients because of unknown DNT (n = 86) or in-hospital stroke (n = 54). There were two low-volume (total 101 patients), five medium-volume (747 patients) and four high-volume hospitals (974 patients). Median DNT was shorter in high-volume hospitals (30 min) than in medium-volume (42 min, p < 0.001) and low-volume hospitals (38 min, p < 0.001). Patients admitted to high-volume hospitals had a higher chance of DNT < 30 min (adjusted OR 3.13, 95 % CI 1.70-5.75), lower risk of symptomatic intracerebral hemorrhage (adjusted OR 0.39, 95 % CI 0.16-0.92), and a lower mortality risk (adjusted OR 0.45, 95 % CI 0.21-1.01), compared to low-volume centers. There was no difference in DNT between low- and medium-volume hospitals. Onset-to-needle times (ONT) did not differ between the groups. Hospitals in this Dutch province generally achieved short DNTs. Despite this overall good performance, higher IVT volumes were associated with shorter DNTs and lower complication risks. The ONT was not associated with IVT volume. PMID:26946499

  8. Pediatric Acute Respiratory Distress Syndrome: Fluid Management in the PICU

    PubMed Central

    Ingelse, Sarah A.; Wösten-van Asperen, Roelie M.; Lemson, Joris; Daams, Joost G.; Bem, Reinout A.; van Woensel, Job B.

    2016-01-01

    The administration of an appropriate volume of intravenous fluids, while avoiding fluid overload, is a major challenge in the pediatric intensive care unit. Despite our efforts, fluid overload is a very common clinical observation in critically ill children, in particular in those with pediatric acute respiratory distress syndrome (PARDS). Patients with ARDS have widespread damage of the alveolar–capillary barrier, potentially making them vulnerable to fluid overload with the development of pulmonary edema leading to prolonged course of disease. Indeed, studies in adults with ARDS have shown that an increased cumulative fluid balance is associated with adverse outcome. However, age-related differences in the development and consequences of fluid overload in ARDS may exist due to disparities in immunologic response and body water distribution. This systematic review summarizes the current literature on fluid imbalance and management in PARDS, with special emphasis on potential differences with adult patients. It discusses the adverse effects associated with fluid overload and the corresponding possible pathophysiological mechanisms of its development. Our intent is to provide an incentive to develop age-specific fluid management protocols to improve PARDS outcomes. PMID:27047904

  9. Pediatric Acute Respiratory Distress Syndrome: Fluid Management in the PICU.

    PubMed

    Ingelse, Sarah A; Wösten-van Asperen, Roelie M; Lemson, Joris; Daams, Joost G; Bem, Reinout A; van Woensel, Job B

    2016-01-01

    The administration of an appropriate volume of intravenous fluids, while avoiding fluid overload, is a major challenge in the pediatric intensive care unit. Despite our efforts, fluid overload is a very common clinical observation in critically ill children, in particular in those with pediatric acute respiratory distress syndrome (PARDS). Patients with ARDS have widespread damage of the alveolar-capillary barrier, potentially making them vulnerable to fluid overload with the development of pulmonary edema leading to prolonged course of disease. Indeed, studies in adults with ARDS have shown that an increased cumulative fluid balance is associated with adverse outcome. However, age-related differences in the development and consequences of fluid overload in ARDS may exist due to disparities in immunologic response and body water distribution. This systematic review summarizes the current literature on fluid imbalance and management in PARDS, with special emphasis on potential differences with adult patients. It discusses the adverse effects associated with fluid overload and the corresponding possible pathophysiological mechanisms of its development. Our intent is to provide an incentive to develop age-specific fluid management protocols to improve PARDS outcomes. PMID:27047904

  10. Effects of Different Tidal Volume Ventilation on Paraquat-Induced Acute Lung Injury in Piglets

    PubMed Central

    Lan, Chao; Wang, Jinzhu; Li, Li; Li, Haina; Li, Lu; Su, Qianqian; Che, Lu; Liu, Lanping; Di, Min

    2015-01-01

    Background The aim of this study was to explore the effects of different tidal volume (VT) ventilation on paraquat-induced acute lung injury or acute respiratory distress syndrome (ALI/ARDS) in piglets. Material/Methods We developed ALI/ARDS models in piglets by intraperitoneal injection of paraquat (PQ). The piglets were randomly divided into three groups: small VT group (VT=6 ml/kg, n=6), middle VT group (VT=10 ml/kg, n=6), and large VT group (VT=15 ml/kg, n=6), with the positive end-expiratory pressure (PEEP) set as 10 cmH2O. The hemodynamics were monitored by pulse-indicated continuous cardiac output (PiCCO) and the airway pressure changes and blood gas analysis indexes were recorded at different time points. The pathological changes were observed by lung puncture. Results The piglets showed ALI/ARDS in 4.5±0.8 hours after PQ intraperitoneal injection. PH, PaO2 and oxygenation indexes in the three groups all decreased after modeling success compared with baseline, and PaCO2 increased significantly. PH in the small VT group decreased most obviously after ventilation for 6 hours. PaO2 and oxygenation indexes in the small VT group showed the most obvious increase after ventilation for 2 hours and were much higher than the other two groups after ventilation for 6 hours. PaCO2 increased gradually after mechanical ventilation and the small VT group showed most obvious increase. The ELWI increased obviously after ventilation for 2 hours and then the small VT group clearly decreased. PIP and plateau pressure (Pplat) in the small VT group decreased gradually and in the middle and large VT group they increased after ventilation. The lung histopathology showed that the large VT group had the most severe damage and the small VT group had only minimal damage. Conclusions Small tidal volume ventilation combined with PEEP could alleviate the acute lung injury induced by paraquat and improve oxygenation. PMID:25671690

  11. Drug Therapy for Acute Heart Failure.

    PubMed

    Di Somma, Salvatore; Magrini, Laura

    2015-08-01

    Acute heart failure is globally one of most frequent reasons for hospitalization and still represents a challenge for the choice of the best treatment to improve patient outcome. According to current international guidelines, as soon as patients with acute heart failure arrive at the emergency department, the common therapeutic approach aims to improve their signs and symptoms, correct volume overload, and ameliorate cardiac hemodynamics by increasing vital organ perfusion. Recommended treatment for the early management of acute heart failure is characterized by the use of intravenous diuretics, oxygen, and vasodilators. Although these measures ameliorate the patient's symptoms, they do not favorably impact on short- and long-term mortality. Consequently, there is a pressing need for novel agents in acute heart failure treatment with the result that research in this field is increasing worldwide. PMID:26088867

  12. The pathophysiology of hypertensive acute heart failure.

    PubMed

    Viau, David M; Sala-Mercado, Javier A; Spranger, Marty D; O'Leary, Donal S; Levy, Phillip D

    2015-12-01

    While acute heart failure (AHF) is often regarded as a single disorder, an evolving understanding recognises the existence of multiple phenotypes with varied pathophysiological alterations. Herein we discuss hypertensive AHF and provide insight into a mechanism where acute fluid redistribution is caused by a disturbance in the ventricular-vascular coupling relationship. In this relationship, acute alterations in vascular elasticity, vasoconstriction and reflected pulse waves lead to increases in cardiac work and contribute to decompensated LV function with associated subendocardial ischaemia and end-organ damage. Chronic predisposing factors (neurohormonal activity, nitric oxide insensitivity, arterial stiffening) and physiological stressors (sympathetic surge, volume overload, physical exertion) that are causally linked to acute symptom onset are discussed. Lastly, we review treatment options including both nitrovasodilators and promising novel therapeutics, and discuss future directions in the management of this phenotypic variant. PMID:26123135

  13. Volume regulatory loss of Na, Cl, and K from rat brain during acute hyponatremia

    SciTech Connect

    Melton, J.E.; Patlak, C.S.; Pettigrew, K.D.; Cserr, H.F.

    1987-04-01

    This study quantitatively evaluates the contribution of tissue Na, Cl, and K loss to brain volume regulation during acute dilutional hyponatremia (DH) and examines the mechanism of Na loss. DH was produced in pentobarbital sodium-anesthetized rats by intraperitoneal infusion of distilled water and brain water and electrolytes analyzed 30 min, 1 h, 3 h, 4 h, or 6 h later. The rate of Na and Cl loss was greatest during the first 30 min of DH. Net loss of Na and Cl was maximal after 3 h of DH. K loss was slower, achieving significance after 3 h. Electrolyte loss was sufficient to account for observed brain volume regulation after three or more hours of DH. Measurements of /sup 22/Na influx and efflux across the blood brain barrier showed that barrier permeability to Na is unchanged during DH. Analysis of results using a two-compartment model of plasma-brain exchange suggests that loss of brain Na during DH does not result solely from a shift of electrolyte across the blood-brain barrier to plasma, and thus provides indirect evidence for an additional pathway for Na loss, presumably via cerebrospinal fluid.

  14. Acute heart failure volume control multicenter randomized (AVCMA) trial: Comparison of tolvaptan and carperitide

    PubMed Central

    Suzuki, Satoshi; Yoshihisa, Akiomi; Yamaki, Takayoshi; Sugimoto, Koichi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Abe, Yukihiko; Saito, Tomiyoshi; Ohwada, Takayuki; Suzuki, Hitoshi; Saitoh, Shu-ichi; Kubota, Isao; Takeishi, Yasuchika

    2013-01-01

    Backgroud Acute decompensated heart failure (ADHF) is a common and highly morbid cardiovascular disorder. Diuresis is a major therapy for the reduction of congestive symptoms. However, most diuretics cause hyponatremia, which is a worsening factor of ADHF patients prognosis. The purpose of this study was to examine the efficacy and safety of tolvaptan, which is a selective vasopressin V2 receptor antagonist and produces water excretion without changes in sodium excretion, compared with carperitide. Methods and Results One hundred and nine hospitalized ADHF patients were enrolled and randomly assigned to tolvaptan or carperitide treatment groups. Subjective symptoms and plasma BNP level were similarly improved by treatment in both groups. Urine volume was significantly higher in the tolvaptan group (P < .05), but volume of water intake was also higher in the tolvaptan group (P < .05). Blood pressure was significantly lower in the carperitide group than in the tolvaptan group after treatment (P < .05). Less adverse events such as worsening heart failure and hypotension requiring drug discontinuation were observed in the tolvaptan group (P = .027). The average drug cost of tolvaptan was lower than that of carperitide (P < .001). Conclusions Tolvaptan might be a novel promising agent for ADHF in terms of efficacy and safety compared to carperitide. PMID:24142853

  15. Greater Volume of Acute Normovolemic Hemodilution May Aid in Reducing Blood Transfusions After Cardiac Surgery

    PubMed Central

    Goldberg, Joshua; Paugh, Paugh; Dickinson, Timothy A.; Fuller, John; Paone, Gaetano; Theurer, Patty F.; Shann, Kenneth G.; Sundt, Thoralf M.; Prager, Richard L.; Likosky, Donald S.

    2016-01-01

    Background Perioperative red blood cell transfusions (RBC) are associated with increased morbidity and mortality after cardiac surgery. Acute normovolemic hemodilution (ANH) is recommended to reduce perioperative transfusions; however, supporting data are limited and conflicting. We describe the relationship between ANH and RBC transfusions after cardiac surgery using a multi-center registry. Methods We analyzed 13,534 patients undergoing cardiac surgery between 2010 and 2014 at any of the 26 hospitals participating in a prospective cardiovascular perfusion database. The volume of ANH (no ANH, <400mL, 400–799mL, ≥800mL) was recorded and linked to each center’s surgical data. We report adjusted relative risks reflecting the association between the use and amount of ANH and the risk of perioperative RBC transfusion. Results were adjusted for preoperative risk factors, procedure, BSA, preoperative HCT, and center. Results ANH was used in 17% of the patients. ANH was associated with a reduction in RBC transfusions (RRadj 0.74, p <0.001). Patients having ≥800mL of ANH had the most profound reduction in RBC transfusions (RRadj 0.57, p<0.001). Platelet and plasma transfusions were also significantly lower with ANH. The ANH population had superior postoperative morbidity and mortality compared to the no ANH population. Conclusions There is a significant association between ANH and reduced perioperative RBC transfusion in cardiac surgery. Transfusion reduction is most profound with larger volumes of ANH. Our findings suggest the volume of ANH, rather than just its use, may be an important feature of a center’s blood conservation strategy. PMID:26206721

  16. CT perfusion cerebral blood volume does not always predict infarct core in acute ischemic stroke.

    PubMed

    d'Esterre, Christopher D; Roversi, Gloria; Padroni, Marina; Bernardoni, Andrea; Tamborino, Carmine; De Vito, Alessandro; Azzini, Cristiano; Marcello, Onofrio; Saletti, Andrea; Ceruti, Stefano; Lee, Ting Yim; Fainardi, Enrico

    2015-10-01

    We investigated the practical clinical utility of the CT perfusion (CTP) cerebral blood volume (CBV) parameter for differentiating salvageable from non-salvageable tissue in acute ischemic stroke (AIS). Fifty-five patients with AIS were imaged within 6 h from onset using CTP. Admission CBV defect (CBVD) volume was outlined using previously established gray and white matter CBV thresholds for infarct core. Admission cerebral blood flow (CBF) hypoperfusion and CBF/CBV mismatch were visually evaluated. Truncation of the ischemic time-density curve (ITDC) and hypervolemia status at admission, recanalization at 24-h CT angiography, hemorrhagic transformation (HT) at 24 h and/or 7-day non-contrast CT (NCCT), final infarct volume as indicated by 3-month NCCT defect (NCCTD) and 3-month modified Rankin Score were determined. Patients with recanalization and no truncation had the highest correlation (R = 0.81) and regression slope (0.80) between CBVD and NCCTD. Regression slopes were close to zero for patients with admission hypervolemia with/without recanalization. Hypervolemia underestimated (p = 0.02), while recanalization and ITDC truncation overestimated (p = 0.03) the NCCTD. Among patients with confirmed recanalization at 24 h, 38 % patients had an admission CBF/CBV mismatch within normal appearing areas on respective NCCT. 83 % of these patients developed infarction in admission hypervolemic CBF/CBV mismatch tissue. A reduction in CBV is a valuable predictor of infarct core when the acquisition of ITDC data is complete and hypervolemia is absent within the tissue destined to infarct. Raised or normal CBV is not always indicative of salvageable tissue, contrary to the current definition of penumbra. PMID:25981225

  17. Systemic iron overload associated with Welder's siderosis.

    PubMed

    Patel, Rajesh R; Yi, Eunhee S; Ryu, Jay H

    2009-01-01

    Welding involves exposure to fumes, gases, radiation, electricity, noise, and heat. Herein, we describe 2 welders presenting with lung infiltrates and elevated liver enzyme levels. Both of these patients had pulmonary siderosis ("welder's lung") on lung biopsy along with evidence of systemic iron overload. Evaluation for genetic hemochromatosis and other known causes of iron overload was unrevealing. Welding with chronic inhalation of iron particles maybe an under-recognized source of systemic iron overload. PMID:18941405

  18. Iterative reconstruction technique with reduced volume CT dose index: diagnostic accuracy in pediatric acute appendicitis

    PubMed Central

    Didier, Ryne A.; Vajtai, Petra L.

    2014-01-01

    Background Iterative reconstruction technique has been proposed as a means of reducing patient radiation dose in pediatric CT. Yet, the effect of such reductions on diagnostic accuracy has not been thoroughly evaluated. Objective This study compares accuracy of diagnosing pediatric acute appendicitis using contrast-enhanced abdominopelvic CT scans performed with traditional pediatric weight-based protocols and filtered back projection reconstruction versus a filtered back projection/iterative reconstruction technique blend with reduced volume CT dose index (CTDIvol). Materials and methods Results of pediatric contrast-enhanced abdominopelvic CT scans done for pain and/or suspected appendicitis were reviewed in two groups: A, 192 scans performed with the hospital’s established weight-based CT protocols and filtered back projection reconstruction; B, 194 scans performed with iterative reconstruction technique and reduced CTDIvol. Reduced CTDIvol was achieved primarily by reductions in effective tube current-time product (mAseff) and tube peak kilovoltage (kVp). CT interpretation was correlated with clinical follow-up and/or surgical pathology. CTDIvol, size specific dose estimates (SSDE) and performance characteristics of the two CT techniques were then compared. Results Between groups A and B, mean CTDIvol was reduced by 45%, and mean SSDE was reduced by 46%. Sensitivity, specificity and diagnostic accuracy were 96%, 97% and 96% in group A vs. 100%, 99% and 99% in group B. Conclusion Accuracy in diagnosing pediatric acute appendicitis was maintained in contrast-enhanced abdominopelvic CT scans that incorporated iterative reconstruction technique, despite reductions in mean CTDIvol and SSDE by nearly half as compared to the hospital’s traditional weight-based protocols. PMID:24996812

  19. The acute effects of manipulating volume and load of back squats on countermovement vertical jump performance.

    PubMed

    Moir, Gavin L; Mergy, David; Witmer, Ca; Davis, Shala E

    2011-06-01

    The acute effects of manipulating the volume and load of back squats on subsequent countermovement vertical jump performance were investigated in the present study. Eleven National Collegiate Athletic Association division II female volleyball players performed 10 countermovement vertical jumps (CMJs) on a force platform 2 minutes after the last squat repetition of a high-load (HL) or high-volume (HV) squat protocol. Two minutes of rest was provided between each CMJ. The HL protocol culminated in the subjects having to perform 3 repetitions with a load equivalent to 90% 1 repetition maximum (1RM) back squat, whereas 12 repetitions with a load equivalent to 37% 1RM were performed in the HV protocol. During an initial familiarization session, knee angles were recorded during a series of CMJs, and these angles were used to control the depth of descent during all subsequent back squats. Jump height (JH) and vertical stiffness (VStiff) were calculated during each of the 10 CMJ, and the change in these variables after the 2 squat protocols was assessed using an analysis of variance model with repeated measures on 2 factors (Protocol [2-levels]; Time [2-levels]). There was no significant difference in JH after the HL and HV protocols (p > 0.05). A significant Protocol × Time interaction for VStiff resulted from the increase after the HL protocol being greater than that after the HV protocol (p = 0.03). The knee angles before the HL and HV protocols were significantly greater than those measured during the initial familiarization session (p = 0.001). Although neither squat protocol provided any benefit in improving JH, the heavy squat protocol produced greater increases in VStiff during the CMJ. Because of the increased VStiff caused by the HL protocol, volleyball coaches may consider using such protocols with their players to improve performance in jumps performed from a run such as the spike and on-court agility. PMID:21293305

  20. Similar acute molecular responses to equivalent volumes of isometric, lengthening, or shortening mode resistance exercise.

    PubMed

    Garma, T; Kobayashi, C; Haddad, F; Adams, G R; Bodell, P W; Baldwin, K M

    2007-01-01

    The present study was undertaken to test the hypothesis that the contraction mode of action [static-isometric (Iso), shortening-concentric (Con), or lengthening-eccentric (Ecc)] used to stress the muscle provides a differential mechanical stimulus eliciting greater or lesser degrees of anabolic response at the initiation of a resistance training program. We performed an acute resistance training study in which different groups of rodents completed four training sessions in either the Iso, Con, or Ecc mode of contraction under conditions of activation and movement specifically designed to elicit equivalent volumes of force accumulation. The results of this experiment indicate that the three modes of contraction produced nearly identical cell signaling, indicative of an anabolic response involving factors such as increased levels of mRNA for IGF-I, procollagen III alpha1, decreased myostatin mRNA, and increased total RNA concentration. The resulting profiles collectively provide evidence that pure mode of muscle action, in and of itself, does not appear to be a primary variable in determining the efficacy of increased loading paradigms with regard to the initiation of selected muscle anabolic responses. PMID:17008438

  1. [Navigation aid through the information overload].

    PubMed

    Günther, Judith; Schindler, Birgit; Suter, Katja

    2014-10-01

    We live in the modern information society. "To be informed" has a crucial impact on the personal, professional, economic and social development. The knowledge of things and their relationships is essential for acute decisions as well as for long-term planning. And at no time it was easier to get the information required within shorter time periods--no matter to whatsoever. The offer of information of the World Wide Web is inexhaustible. This also applies to information about all possible therapeutic and pharmaceutical issues. But is the information found reliable, too? And are easily accessible sources credible? Can we deal with the information overload at these days or do we actually risk paddling only on the surface of the "information-sea", without ever perceiving the actual information depth and width, less to use it? How can we protect being taken in by marketing strategies? The present article describes a structured proceed when seeking literature to find useful medical and pharmaceutical information in a time saving manner. PMID:25632609

  2. Genetics Home Reference: African iron overload

    MedlinePlus

    ... of a genetic condition? Genetic and Rare Diseases Information Center Frequency African iron overload is common in rural areas of central and ... more about the gene associated with African iron overload SLC40A1 Related Information What is a gene? What is a gene ...

  3. A Test of the Urban Overload Hypothesis.

    ERIC Educational Resources Information Center

    McCauley, Clark R.

    This paper briefly discusses three studies aimed at exploring the overload hypothesis posited by Stanley Milgram. That hypothesis suggests that impoverished social interaction in the city is an adaptation to overload of interpersonal contacts. The three studies examine various aspects of the phenomenon using different methodologies. Comparing city…

  4. Role of cardiac volume receptors in the control of ADH release during acute simulated weightlessness in man

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Benjamin, B. A.; Keil, L. C.; Sandler, H.

    1984-01-01

    Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes, designed to induce central blood volume shifts in ten cardiac and one heart-lung transplant recipients, to assess the contribution of cardiac volume receptors in the control of ADH release during the initial acute phase of exposure to weightlessness. Each subject underwent 15 min of a sitting-control period (C) followed by 30 min of 6 deg headdown tilt (T) and 30 min of resumed sitting (S). Venous blood samples and cardiac dimensions were taken at 0 and 15 min of C; 5, 15, and 30 min of T; and 5, 15, and 30 min of S. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Heart rate and blood pressure were recorded every two min. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P less than 0.05) from 90 ml in C to 106 ml in T and returned to 87 ml in S. Plasma ADH was reduced by 20 percent (P less than 0.05) with T, and returned to control levels with S. These responses were similar in six normal cardiac-innervated control subjects. These data may suggest that cardiac volume receptors are not the primary mechanism for the control of ADH release during acute central volume shifts in man.

  5. CXCR4 gene transfer prevents pressure overload induced heart failure

    PubMed Central

    LaRocca, Thomas J.; Jeong, Dongtak; Kohlbrenner, Erik; Lee, Ahyoung; Chen, JiQiu; Hajjar, Roger J.; Tarzami, Sima T.

    2012-01-01

    Stem cell and gene therapies are being pursued as strategies for repairing damaged cardiac tissue following myocardial infarction in an attempt to prevent heart failure. The chemokine receptor-4 (CXCR4) and its ligand, CXCL12, play a critical role in stem cell recruitment post-acute myocardial infarction. Whereas progenitor cell migration via the CXCL12/CXCR4 axis is well characterized, little is known about the molecular mechanisms of CXCR4 mediated modulation of cardiac hypertrophy and failure. We used gene therapy to test the effects of CXCR4 gene delivery on adverse ventricular remodeling due to pressure overload. We assessed the effect of cardiac overexpression of CXCR4 during trans-aortic constriction (TAC) using a cardiotropic adeno-associated viral vector (AAV9) carrying the CXCR4 gene. Cardiac overexpression of CXCR4 in mice with pressure overload prevented ventricular remodeling, preserved capillary density and maintained function as determined by echocardiography and in vivo hemodynamics. In isolated adult rat cardiac myocytes, CXCL12 treatment prevented isoproterenol induced hypertrophy and interrupted the calcineurin/NFAT pathway. Finally, a complex involving the L-type calcium channel, β2-adenoreceptor, and CXCR4 (Cav1.2/β2AR/CXCR4) was identified in healthy cardiac myocytes and was shown to dissociate as a consequence of heart failure. CXCR4 administered to the heart via gene transfer prevents pressure overload induced heart failure. The identification of CXCR4 participation in a Cav1.2-β2AR regulatory complex provides further insight into the mechanism by which CXCR4 modulates calcium homeostasis and chronic pressure overload responses in the cardiac myocyte. Together these results suggest AAV9.CXCR4 gene therapy is a potential therapeutic approach for congestive heart failure. PMID:22668785

  6. Transfusion-associated circulatory overload in orthopedic surgery patients: a multi-institutional study.

    PubMed

    Popovsky, M A; Audet, A M; Andrzejewski, C

    1996-01-01

    Although recognized as a serious complication of hemotherapy, few data are available on the incidence of transfusion-associated circulatory overload (TACO). Detailed demographic and clinical information was obtained from records of 382 Medicare patients undergoing total hip or knee replacements (and receiving transfusions) from January 1992 to December 1993 at five Massachusetts hospitals. Seventy-eight percent of the patients were women with a mean age of 77 years. Thirty-two percent had co-morbidities including myocardial or coronary disease. Transfusion-related complications and comorbidities were identified and reviewed by transfusion experts. Patients were excluded from consideration if non-transfusion factors such as myocardial disease could have contributed to the development of acute pulmonary edema. Four (3 females, 1 male) patients (1.05%) developed TACO postoperatively. Mean age of these patients was 84 years (range, 75-101) versus 77 years for non-TACO. The mean intraoperative estimated blood loss was 375 mL. Each patient received only 1-2 units of red blood cells prior to onset of TACO, and in two cases only autologous blood was used. The mean positive fluid balance was 2,480 mL. The mean pretransfusion hematocrit prior to circulatory overload (CO) was 26.0 percent. Symptoms were reversed with diuretics. Length of stay was significantly prolonged by these incidents. TACO is a frequent and serious event in an orthopedic surgical setting. It is associated with advanced age, increased health care costs, and may occur in the setting of modest transfusion volumes. The utilization of conservative transfusion criteria and fluid management in the perioperative setting may decrease the incidence of this complication in this population. PMID:15387748

  7. Coupling between gamma-band power and cerebral blood volume during recurrent acute neocortical seizures

    PubMed Central

    Harris, Sam; Ma, Hongtao; Zhao, Mingrui; Boorman, Luke; Zheng, Ying; Kennerley, Aneurin; Bruyns-Haylett, Michael; Overton, Paul G.; Berwick, Jason; Schwartz, Theodore H.

    2014-01-01

    Characterization of neural and hemodynamic biomarkers of epileptic activity that can be measured using non-invasive techniques is fundamental to the accurate identification of the epileptogenic zone (EZ) in the clinical setting. Recently, oscillations at gamma-band frequencies and above (> 30 Hz) have been suggested to provide valuable localizing information of the EZ and track cortical activation associated with epileptogenic processes. Although a tight coupling between gamma-band activity and hemodynamic-based signals has been consistently demonstrated in non-pathological conditions, very little is known about whether such a relationship is maintained in epilepsy and the laminar etiology of these signals. Confirmation of this relationship may elucidate the underpinnings of perfusion-based signals in epilepsy and the potential value of localizing the EZ using hemodynamic correlates of pathological rhythms. Here, we use concurrent multi-depth electrophysiology and 2-dimensional optical imaging spectroscopy to examine the coupling between multi-band neural activity and cerebral blood volume (CBV) during recurrent acute focal neocortical seizures in the urethane-anesthetized rat. We show a powerful correlation between gamma-band power (25–90 Hz) and CBV across cortical laminae, in particular layer 5, and a close association between gamma measures and multi-unit activity (MUA). Our findings provide insights into the laminar electrophysiological basis of perfusion-based imaging signals in the epileptic state and may have implications for further research using non-invasive multi-modal techniques to localize epileptogenic tissue. PMID:24736180

  8. Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury

    PubMed Central

    Bouhemad, Bélaid; Richecoeur, Jack; Lu, Qin; Malbouisson, Luiz M; Cluzel, Philippe; Rouby, Jean-Jacques

    2003-01-01

    Background Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury. Method A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n = 7) or 15 min (group 2; n = 7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview®; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated. Results Injection of contrast material significantly increased the apparent volume of lung tissue by 83 ± 57 ml in group 1 and 102 ± 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 ± 52 ml and 31 ± 18 ml. Conclusion Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications. PMID:12617742

  9. Effect of Bra Use during Radiotherapy for Large-Breasted Women: Acute Toxicity and Treated Heart and Lung Volumes

    PubMed Central

    Keller, Lanea; Cohen, Randi; Sopka, Dennis M; Li, Tianyu; Li, Linna; Anderson, Penny R; Fowble, Barbara L.; Freedman, Gary M

    2012-01-01

    Purpose Large breast size presents special problems during radiation simulation, planning and patient treatment, including increased skin toxicity, in women undergoing breast-conserving surgery and radiotherapy (BCT). We report our experience using a bra during radiation in large-breasted women and its effect on acute toxicity and heart and lung dosimetry. Materials and methods From 2001 to 2006, 246 consecutive large-breasted women (bra size ≥ 38 and/or ≥ D cup) were treated with BCT using either 3D conformal (3D-CRT) or Intensity Modulated Radiation (IMRT). In 58 cases, at the physicians’ discretion, a custom-fit bra was used during simulation and treatment. Endpoints were acute radiation dermatitis, and dosimetric comparison of heart and lung volumes in a subgroup of 12 left-sided breast cancer patients planned with and without a bra. Results The majority of acute skin toxicities were grade 2 and were experienced by 90% of patients in a bra compared to 70% of patients not in a bra (p=0.003). On multivariate analysis significant predictors of grade 2/3 skin toxicity included 3D-CRT instead of IMRT (OR=3.9, 95% CI:1.8-8.5) and the use of a bra (OR=5.5, 95% CI:1.6-18.8). For left-sided patients, use of a bra was associated with a volume of heart in the treatment fields decreased by 63.4% (p=0.002), a volume of left lung decreased by 18.5% (p=0.25), and chest wall separation decreased by a mean of 1 cm (p=0.03). Conclusions The use of a bra to augment breast shape and position in large-breasted women is an alternative to prone positioning and associated with reduced chest wall separation and reduced heart volume within the treatment field. PMID:23459714

  10. Overload protection system for power inverter

    NASA Technical Reports Server (NTRS)

    Nagano, S. (Inventor)

    1977-01-01

    An overload protection system for a power inverter utilized a first circuit for monitoring current to the load from the power inverter to detect an overload and a control circuit to shut off the power inverter, when an overload condition was detected. At the same time, a monitoring current inverter was turned on to deliver current to the load at a very low power level. A second circuit monitored current to the load, from the monitoring current inverter, to hold the power inverter off through the control circuit, until the overload condition was cleared so that the control circuit may be deactivated in order for the power inverter to be restored after the monitoring current inverter is turned off completely.

  11. [IRON OVERLOAD: BETTER UNDERSTANDING, BETTER CARE].

    PubMed

    Brissot, Pierre

    2015-12-01

    Chronic iron overload, either of genetic (hemochromatoses) or acquired (transfusions) origin, leads to frequent disorders, affecting both the quality of life and life expectancy. Major recent advances in the knowledge of iron metabolism, together with advances in biology, imaging and drug design have already significantly improved the diagnostic and therapeutic approaches. These conceptual and technological ameliorations should, in the near future, continue to benefit the clinical management of iron overloaded patients. PMID:26979029

  12. Iron Overload in Survivors of Childhood Cancer.

    PubMed

    Schempp, Ashley; Lee, Jill; Kearney, Susan; Mulrooney, Daniel A; Smith, Angela R

    2016-01-01

    Iron overload is a significant cause of morbidity and mortality for patients who require frequent transfusions. We completed a prospective, cross-sectional study to evaluate the prevalence of iron overload in previously transfused childhood cancer survivors. Survivors recruited from the University of Minnesota Long-Term Follow-Up Clinic were stratified into 3 groups: oncology patients not treated with hematopoietic stem cell transplantation (HSCT) (n=27), patients treated with allogeneic HSCT (n=27), and patients treated with autologous HSCT (n=9). Serum ferritin was collected and hepatic magnetic resonance imaging (FerriScan) was obtained for those with iron overload (defined as ferritin ≥1000 ng/mL). The prevalence of iron overload in subjects with a history of allogeneic HSCT was 25.9% (95% CI, 9.4%-42.5%) compared with only 3.7% (95% CI, 0%-10.8%) in subjects treated without HSCT and 0% in subjects treated with autologous HSCT. No association was found between serum ferritin levels and the presence of cardiac, liver, or endocrine dysfunction. The prevalence of iron overload in subjects who received no HSCT or autologous HSCT is low in our study. A higher prevalence was found in patients receiving allogeneic HSCT, reiterating the importance of screening these patients for iron overload in accordance with the current Children's Oncology Group Long Term Follow-Up Guidelines. PMID:26422286

  13. Lithium clearance in man: effects of dietary salt intake, acute changes in extracellular fluid volume, amiloride and frusemide.

    PubMed

    Atherton, J C; Green, R; Hughes, S; McFall, V; Sharples, J A; Solomon, L R; Wilson, L

    1987-12-01

    1. The effects of amiloride and frusemide on lithium clearance were studied during changes in dietary sodium chloride intake and during infusion of 0.9% NaCl in normal human volunteers. 2. Lithium and fractional lithium clearances were less on the low than on the high salt diet. Values for the medium salt diet were intermediate. Acute extracellular fluid volume expansion with 0.9% NaCl infusion and extracellular fluid volume contraction 3-4 h after intravenous frusemide caused lithium and fractional lithium clearances to increase and decrease respectively. 3. Amiloride caused small changes in lithium and fractional lithium clearances on a low salt diet, but was without effect when salt intake was medium or high. 4. Increases in lithium clearance occurred immediately after frusemide irrespective of dietary salt intake and in subjects infused with 0.9% NaCl. Only in salt-depleted subjects did frusemide cause a substantial increase in fractional lithium clearance. Changes induced under other circumstances were small. 5. It is concluded that the lithium clearance method for assessment of proximal tubule salt and water reabsorption can be used with some degree of confidence in certain circumstances (medium and high salt intake as well as in acute volume expansion) but may not be reliable when dietary salt intake is low. PMID:3690979

  14. Self Organized Spatial-Temporal Structure within the Fractured Vadose Zone: The Influence of Dynamic Overloading at Fracture Intersections

    SciTech Connect

    Randall A. Laviolette

    2004-09-01

    Under low flow conditions (where gravity and capillary forces dominate) within an unsaturated fracture network, fracture intersections act as capillary barriers to integrate flow from above and then release it as a pulse below. Water exiting a fracture intersection is often thought to enter the single connected fracture with the lowest invasion pressure. When the accumulated volume varies between intersections, the smaller volume intersections can be overloaded to cause all of the available fractures exiting an intersection to flow. We included the dynamic overloading process at fracture intersections within our previously discussed model where intersections were modeled as tipping buckets connected within a two-dimensional diamond lattice. With dynamic overloading, the flow behavior transitioned smoothly from diverging to converging flow with increasing overload parameter, as a consequence of a heterogeneous field, and they impose a dynamic structure where additional pathways activate or deactivate in time.

  15. Effect of anabolic steroids on overloaded and overloaded suspended skeletal muscle.

    PubMed

    Tsika, R W; Herrick, R E; Baldwin, K M

    1987-11-01

    The purpose of this study was to ascertain whether anabolic steroids act synergistically with functional overload in terms of increasing muscle weight and subcellular protein content of normal overloaded and suspended overloaded rodent plantaris muscle. Female rats were randomly assigned to six groups (7 rats/group) for 6 wk: 1) normal control (NC), 2) overload (OV), 3) overload steroid (OV-S), 4) normal suspended (N-SUS), 5) overload suspended (OV-SUS), and 6) overload suspended steroid (OV-SUS-S). Rats receiving anabolic steroid were administered 0.3 mg nandrolone decanoate (Deca-Durabolin) per day. Relative to control values, overload induced 1) sparing of muscle weight of the OV-SUS group as well as larger absolute and normalized (mg muscle/g body wt) muscle weight of the OV group (P less than 0.05), 2) greater protein content (mg/muscle, P less than 0.05), and 3) an increased relative expression of slow myosin in both the OV and OV-SUS groups (P less than 0.05). Although anabolic steroid treatment of overload animals (OV-S) did not alter further the pattern of response of any parameter analyzed for the OV group, it did induce larger absolute and normalized muscle weight (P less than 0.05) as well as a greater protein content (mg/muscle, P less than 0.05) of the OV-SUS-S group compared with control values. However, anabolic steroid treatment did not alter the pattern of isomyosin expression observed in the overload (OV-S vs. OV) or overload suspended (OV-SUS-S vs. OV-SUS) groups.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3693242

  16. Acute angles of head-up tilt do not affect forearm and hand volume.

    PubMed

    Boland, R A; Adams, R D

    2000-01-01

    Physiotherapists utilise the effect of gravity in treatment of conditions associated with increased limb volume. In contrast with knowledge about the relationship between body position and lower limb volume, the effect of body position on arm volume is not well understood. To assess the efficacy of a simple intervention proposed for patients to reduce arm volume during sleep, this study investigated the effects on forearm and hand volume of two hours of head-up tilt in supine at three angles of 8, 11 and 14 degrees. Six asymptomatic subjects were measured at each tilt angle over a three-week period. Data indicated that no angle of head-up lying over a two-hour period was associated with any significant reduction in upper limb volume. PMID:11543301

  17. Evaluation of Reduced Sediment Volume Procedures for Acute Toxicity Tests Using the Estuarine Amphipod Leptocheirus plumulosus

    EPA Science Inventory

    The volume of sediment required to perform a sediment toxicity bioassay is a major driver of the overall cost associated with that bioassay. Sediment volume affects bioassay cost due to sediment collection, transportation, storage, and disposal costs as well as labor costs assoc...

  18. [Acute Kidney Injury, Type - 3 cardiorenal syndrome, Biomarkers, Renal Replacement Therapy].

    PubMed

    Di Lullo, Luca; Bellasi, Antonio; Barbera, Vincenzo; Cozzolino, Mario; Russo, Domenico; De Pascalis, Antonio; Santoboni, Francesca; Villani, Annalisa; De Rosa, Silvia; Colafelice, Marco; Russo, Luigi; Ronco, Claudio

    2016-01-01

    Cardiovascular disease and major cardiovascular events represent main cause of death in both acute and chronic kidney disease patients. Kidney and heart failure are common and frequently co-exist This organ-organ interaction, also called organ cross-talk, leads to well-known definition of cardiorenal syndrome (CRS). Here we will describe cardiovascular involvement in patients with acute kidney injury (AKI). Also known as Type-3 CRS or acute reno-cardiac CRS, it occurs when AKI contributes and/or precipitates development of acute cardiac injury. AKI may directly or indirectly produces an acute cardiac event and it can be associated with volume overload, metabolic acidosis and electrolytes disorders such as hyperkalemia and hypocalcemia, coronary artery disease, left ventricular dysfunction and fibrosis which has been also described in patients with AKI with the consequence of direct negative effects on cardiac performance. PMID:27374388

  19. Global Transcriptional Response to Hfe Deficiency and Dietary Iron Overload in Mouse Liver and Duodenum

    PubMed Central

    Rodriguez, Alejandra; Luukkaala, Tiina; Fleming, Robert E.; Britton, Robert S.; Bacon, Bruce R.; Parkkila, Seppo

    2009-01-01

    Iron is an essential trace element whose absorption is usually tightly regulated in the duodenum. HFE-related hereditary hemochromatosis (HH) is characterized by abnormally low expression of the iron-regulatory hormone, hepcidin, which results in increased iron absorption. The liver is crucial for iron homeostasis as it is the main production site of hepcidin. The aim of this study was to explore and compare the genome-wide transcriptome response to Hfe deficiency and dietary iron overload in murine liver and duodenum. Illumina™ arrays containing over 47,000 probes were used to study global transcriptional changes. Quantitative RT-PCR (Q-RT-PCR) was used to validate the microarray results. In the liver, the expression of 151 genes was altered in Hfe−/− mice while dietary iron overload changed the expression of 218 genes. There were 173 and 108 differentially expressed genes in the duodenum of Hfe−/− mice and mice with dietary iron overload, respectively. There was 93.5% concordance between the results obtained by microarray analysis and Q-RT-PCR. Overexpression of genes for acute phase reactants in the liver and a strong induction of digestive enzyme genes in the duodenum were characteristic of the Hfe-deficient genotype. In contrast, dietary iron overload caused a more pronounced change of gene expression responsive to oxidative stress. In conclusion, Hfe deficiency caused a previously unrecognized increase in gene expression of hepatic acute phase proteins and duodenal digestive enzymes. PMID:19787063

  20. Overload-Induced Skeletal Muscle Extracellular Matrix Remodeling And Myofiber Growth in Mice Lacking IL-6

    PubMed Central

    White, James P.; Reecy, James M.; Washington, Tyrone A.; Sato, Shuichi; Le, Michael E.; Davis, J. Mark; Wilson, L. Britt; Carson, James A.

    2011-01-01

    Aim Overloading healthy skeletal muscle produces myofiber hypertrophy and extracellular matrix remodeling, and these processes are thought to be interdependent for producing muscle growth. Inflammatory cytokine interleukin-6 (IL-6) gene expression is induced in overloaded skeletal muscle, and the loss of this IL-6 induction can attenuate the hypertrophic response to overload. Although the overload induction of IL-6 in skeletal muscle may be an important regulator of inflammatory processes and satellite cell proliferation, less is known about its role in the regulation of extracellular matrix remodeling. The purpose of the current study was to examine if overload-induced extracellular matrix remodeling, muscle growth, and associated gene expression were altered in mice that lack IL-6, when compared to wild-type mice. Methods Male C57/BL6 (WT) and C57/BL6 × IL-6-/- (IL-6-/-) mice (10 wks of age) were assigned to either a sham control or synergist ablation overload (OV) treatments for 3 or 21 days. Results Plantaris muscle mass increased 59% in WT and 116% in IL-6-/- mice after 21d OV. Myofiber CSA was also increased by 21d OV in both WT and IL-6-/- mice. Overload induced a 2-fold greater increase in the volume of non-contractile tissue in IL-6-/- muscle as compared to WT. Overload also induced a significantly greater accumulation of hydroxyproline and procollagen-1 mRNA in IL-6-/- muscle, when compared to WT muscle after 21d OV. TGF-β and IGF-1 mRNA expression were also induced to a greater extent in IL-6-/- muscle when compared to WT muscle after 21d OV. There was no effect of IL-6 loss on the induction of myogenin, and cyclin D1 mRNA expression after 3d OV. However, MyoD mRNA expression in 3d OV IL-6-/- muscle was attenuated when compared to WT overload mice. Conclusion IL-6 appears to be necessary for the normal regulation of extracellular matrix remodeling during overload-induced growth. PMID:19681796

  1. Hyperthyroidism as a reversible cause of right ventricular overload and congestive heart failure

    PubMed Central

    Di Giovambattista, Raniero

    2008-01-01

    We describe a case of severe congestive heart failure and right ventricular overload associated with overt hyperthyroidism, completely reversed with antithyroid therapy in a few week. It represents a very unusual presentation of overt hyperthyroidism because of the severity of right heart failure. The impressive right ventricular volume overload made mandatory to perform transesophageal echo and angio-TC examination to exclude the coexistence of ASD or anomalous pulmonary venous return. Only a few cases of reversible right heart failure, with or without pulmonary hypertension, have been reported worldwide. In our case the most striking feature has been the normalization of the cardiovascular findings after six weeks of tiamazole therapy. PMID:18549503

  2. Dosimetric Coverage of the Prostate, Normal Tissue Sparing, and Acute Toxicity with High-Dose-Rate Brachytherapy for Large Prostate Volumes

    PubMed Central

    Yang, George; Strom, Tobin J.; Wilder, Richard B.; Shrinath, Kushagra; Mellon, Eric A.; Fernandez, Daniel C.; Biagioli, Matthew C.

    2015-01-01

    ABSTRACT Purpose To evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes. Materials and Methods One hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL) were treated with high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38%) unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4. Results Median follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3%) patients developed Grade 2 acute proctitis. No variables were significantly associated with Grade 2 acute proctitis. Seventeen of 102 (17%) patients developed Grade 2 acute urinary retention. American Urological Association (AUA) symptom score was the only variable significantly associated with Grade 2 acute urinary retention (p=0.04). There was no ≥ Grade 3 acute toxicity. Conclusions Dosimetric coverage of the prostate and normal tissue sparing were adequate in patients with prostate volumes >50 mL. Higher pre-treatment AUA symptom scores increased the relative risk of Grade 2 acute urinary retention. However, the overall incidence of acute toxicity was acceptable in patients with large prostate volumes. PMID:26200536

  3. The Impact of Pretreatment Prostate Volume on Severe Acute Genitourinary Toxicity in Prostate Cancer Patients Treated With Intensity-Modulated Radiation Therapy

    SciTech Connect

    Aizer, Ayal A.; Anderson, Nicole S.; Oh, Steven C.; Yu, James B.; McKeon, Anne M.; Decker, Roy H.; Peschel, Richard E.

    2011-02-01

    Purpose: To assess the impact of pretreatment prostate volume on the development of severe acute genitourinary toxicity in patients undergoing intensity-modulated radiation therapy (IMRT) for prostate cancer. Methods and Materials: Between 2004 and 2007, a consecutive sample of 214 patients who underwent IMRT (75.6 Gy) for prostate cancer at two referral centers was analyzed. Prostate volumes were obtained from computed tomography scans taken during treatment simulation. Genitourinary toxicity was defined using the National Cancer Institute Common Terminology Criteria for Adverse Events Version 3.0 guidelines. Acute toxicity was defined as any toxicity originating within 90 days of the completion of radiation therapy. Patients were characterized as having a small or large prostate depending on whether their prostate volume was less than or greater than 50 cm{sup 3}, respectively. Genitourinary toxicity was compared in these groups using the chi-square or Fisher's exact test, as appropriate. Bivariate and multivariate logistic regression analysis was performed to further assess the impact of prostate volume on severe (Grade 3) acute genitourinary toxicity. Results: Patients with large prostates (>50 cm{sup 3}) had a higher rate of acute Grade 3 genitourinary toxicity (p = .02). Prostate volume was predictive of the likelihood of developing acute Grade 3 genitourinary toxicity on bivariate (p = .004) and multivariate (p = .006) logistic regression. Every 27.0 cm{sup 3} increase in prostate volume doubled the likelihood of acute Grade 3 genitourinary toxicity. Conclusions: Patients with larger prostates are at higher risk for the development of severe acute genitourinary toxicity when treated with IMRT for prostate cancer.

  4. Acute small bowel toxicity and preoperative chemoradiotherapy for rectal cancer: Investigating dose-volume relationships and role for inverse planning

    SciTech Connect

    Tho, Lye Mun . E-mail: l.tho@beatson.gla.ac.uk; Glegg, Martin; Paterson, Jennifer; Yap, Christina; MacLeod, Alice; McCabe, Marie; McDonald, Alexander C.

    2006-10-01

    Purpose: The relationship between volume of irradiated small bowel (VSB) and acute toxicity in rectal cancer radiotherapy is poorly quantified, particularly in patients receiving concurrent preoperative chemoradiotherapy. Using treatment planning data, we studied a series of such patients. Methods and Materials: Details of 41 patients with locally advanced rectal cancer were reviewed. All received 45 Gy in 25 fractions over 5 weeks, 3-4 fields three-dimensional conformal radiotherapy with daily 5-fluorouracil and folinic acid during Weeks 1 and 5. Toxicity was assessed prospectively in a weekly clinic. Using computed tomography planning software, the VSB was determined at 5 Gy dose intervals (V{sub 5}, V{sub 1}, etc.). Eight patients with maximal VSB had dosimetry and radiobiological modeling outcomes compared between inverse and conformal three-dimensional planning. Results: VSB correlated strongly with diarrheal severity at every dose level (p < 0.03), with strongest correlation at lowest doses. Median VSB differed significantly between patients experiencing Grade 0-1 and Grade 2-4 diarrhea (p {<=} 0.05). No correlation was found with anorexia, nausea, vomiting, abdominal cramps, age, body mass index, sex, tumor position, or number of fields. Analysis of 8 patients showed that inverse planning reduced median dose to small bowel by 5.1 Gy (p = 0.008) and calculated late normal tissue complication probability (NTCP) by 67% (p = 0.016). We constructed a model using mathematical analysis to predict for acute diarrhea occurring at V{sub 5} and V{sub 15}. Conclusions: A strong dose-volume relationship exists between VSB and acute diarrhea at all dose levels during preoperative chemoradiotherapy. Our constructed model may be useful in predicting toxicity, and this has been derived without the confounding influence of surgical excision on bowel function. Inverse planning can reduce calculated dose to small bowel and late NTCP, and its clinical role warrants further

  5. Acute pressure overload of the right ventricle. Comparison of two models of right-left shunt. Pulmonary artery to left atrium and right atrium to left atrium: experimental study

    PubMed Central

    2011-01-01

    Abtract Background In right ventricular failure (RVF), an interatrial shunt can relieve symptoms of severe pulmonary hypertension by reducing right ventricular preload and increasing systemic flow. Using a pig model to determine if a pulmonary artery - left atrium shunt (PA-LA) is better than a right atrial - left atrial shunt (RA-LA), we compared the hemodynamic effects and blood gases between the two shunts. Methods Thirty, male Large White pigs weighting in average 21.3 kg ± 0.7 (SEM) were divided into two groups (15 pigs per group): In group 1, banding of the pulmonary artery and a pulmonary artery to left atrium shunt with an 8 mm graft (PA-LA) was performed and in group 2 banding of the pulmonary artery and right atrial to left atrial shunt (RA-LA) with a similar graft was performed. Hemodynamic parameters and blood gases were measured from all cardiac chambers in 10 and 20 minutes, half and one hour interval from the baseline (30 min from the banding). Cardiac output and flow of at the left anterior descending artery was also monitored. Results In both groups, a stable RVF was generated. The PA-LA shunt compared to the RA-LA shunt has better hemodynamic performance concerning the decreased right ventricle afterload, the 4 fold higher mean pressure of the shunt, the better flow in left anterior descending artery and the decreased systemic vascular resistance. Favorable to the PA-LA shunt is also the tendency - although not statistically significant - in relation to central venous pressure, left atrial filling and cardiac output. Conclusion The PA-LA shunt can effectively reverse the catastrophic effects of acute RVF offering better hemodynamic characteristics than an interatrial shunt. PMID:22011551

  6. Accuracy of Family History of Hemochromatosis or Iron Overload: The Hemochromatosis and Iron Overload Screening Study

    PubMed Central

    Acton, Ronald T.; Barton, James C.; Passmore, Leah V.; Adams, Paul C.; Mclaren, Gordon D.; Leiendecker–Foster, Catherine; Speechley, Mark R.; Harris, Emily L.; Castro, Oswaldo; Reiss, Jacob A.; Snively, Beverly M.; Harrison, Barbara W.; Mclaren, Christine E.

    2013-01-01

    Background & Aims The aim of this study was to assess the analytic validity of self-reported family history of hemochromatosis or iron overload. Methods A total of 141 probands, 549 family members, and 641 controls participated in the primary care Hemochromatosis and Iron Overload Screening Study. Participants received a postscreening clinical examination and completed questionnaires about personal and family histories of hemochromatosis or iron overload, arthritis, diabetes, liver disease, and heart disease. We evaluated sensitivities and specificities of proband-reported family history, and concordance of HFE genotype C282Y/C282Y in probands and siblings who reported having hemochromatosis or iron overload. Results The sensitivities of proband-reported family history ranged from 81.4% for hemochromatosis or iron overload to 18.4% for liver disease; specificities for diabetes, liver disease, and heart disease were greater than 94%. Hemochromatosis or iron overload was associated with a positive family history across all racial/ethnic groups in the study (odds ratio, 14.53; 95% confidence intervals, 7.41–28.49; P < .0001) and among Caucasians (odds ratio, 16.98; 95% confidence intervals, 7.53–38.32; P < .0001). There was 100% concordance of HFE genotype C282Y/C282Y in 6 probands and 8 of their siblings who reported having hemochromatosis or iron overload. Conclusions Self-reported family history of hemochromatosis or iron overload can be used to identify individuals whose risk of hemochromatosis or iron overload and associated conditions is increased. These individuals could benefit from further evaluation with iron phenotyping and HFE mutation analysis. PMID:18585964

  7. The Leukocyte Antibody Prevalence Study-II (LAPS-II): a retrospective cohort study of transfusion-related acute lung injury in recipients of high-plasma-volume human leukocyte antigen antibody–positive or –negative components

    PubMed Central

    Kleinman, Steven H.; Triulzi, Darrell J.; Murphy, Edward L.; Carey, Patricia M.; Gottschall, Jerome L.; Roback, John D.; Carrick, Danielle; Mathew, Sunitha; Wright, David J.; Cable, Ritchard; Ness, Paul; Gajic, Ognjen; Hubmayr, Rolf D.; Looney, Mark R.; Kakaiya, Ram M.

    2013-01-01

    BACKGROUND We used a multicenter retrospective cohort study design to evaluate whether human leukocyte antigen (HLA) antibody donor screening would reduce the risk of transfusion-related acute lung injury (TRALI) or possible TRALI. STUDY DESIGN AND METHODS In the Leukocyte Antibody Prevalence Study-II (LAPS-II), we evaluated pulmonary outcomes in recipients of 2596 plasma-rich blood components (transfusable plasma and plateletpheresis) sent to participating hospitals; half of the components were collected from anti-HLA–positive donors (study arm) and half from anti-HLA–negative donors (control arm) matched by sex, parity, and blood center. A staged medical record review process was used. Final recipient diagnosis was based on case review by a blinded expert panel of pulmonary or critical care physicians. RESULTS TRALI incidence was 0.59% (seven cases) in study arm recipients versus 0.16% (two cases) in control arm recipients for an odds ratio (OR) of 3.6 (95% confidence interval [CI], 0.7–17.4; p = 0.10). For possible TRALI cases (nine study arm, eight control arm), the OR was 1.2 (95% CI, 0.4–3.0; p = 0.81), and for TRALI and possible TRALI aggregated together, it was 1.7 (95% CI, 0.7–3.7; p = 0.24). Transfusion-associated circulatory overload incidence was identical in the two arms (1.17 and 1.22%, respectively; OR, 1.0; p = 1.0). CONCLUSIONS TRALI incidence in recipients of anti-HLA–positive components was relatively low for a look-back study (1 in 170) and was higher than in the control arm, but did not reach significance. Based on this trend, the data are consistent with the likelihood that TRALI risk is decreased by selecting high-volume plasma components for transfusion from donors at low risk of having HLA antibodies. PMID:21446938

  8. The prevention of transfusion-associated circulatory overload.

    PubMed

    Alam, Asim; Lin, Yulia; Lima, Ana; Hansen, Mark; Callum, Jeannie L

    2013-04-01

    Transfusion-associated circulatory overload (TACO) is an important and potentially injurious complication of transfusion that is underappreciated by clinicians. Risk factors for TACO include being at an extreme of age, having preexisting cardiac and/or (potentially) renal dysfunction, acute myocardial infarction, and individuals receiving plasma. Keys to preventing TACO, aside from identifying high-risk individuals, should be multifaceted. We advocate for the widespread use of pretransfusion checklists and implementation of nonemergent transfusion protocols. We suggest the regular use of pretransfusion diuretics in high-risk individuals. When a transfusion is required, we believe that "critical" nursing supervision and leadership are instrumental in the coordination of slow transfusion rates on computerized infusion pumps and ensuring patients are appropriately monitored. We believe that using these methodologies on a global scale will prevent many TACO events and minimize the severity when it does occur. PMID:23465703

  9. Dynamic and Static Overloading Induce Early Degenerative Processes in Caprine Lumbar Intervertebral Discs

    PubMed Central

    Paul, Cornelis P. L.; Schoorl, Tom; Zuiderbaan, Hendrik A.; Zandieh Doulabi, Behrouz; van der Veen, Albert J.; van de Ven, Peter M.; Smit, Theo H.; van Royen, Barend J.; Helder, Marco N.; Mullender, Margriet G.

    2013-01-01

    Mechanical overloading of the spine is associated with low back pain and intervertebral disc (IVD) degeneration. How excessive loading elicits degenerative changes in the IVD is poorly understood. Comprehensive knowledge of the interaction between mechanical loading, cell responses and changes in the extracellular matrix of the disc is needed in order to successfully intervene in this process. The purpose of the current study was to investigate whether dynamic and static overloading affect caprine lumbar discs differently and what mechanisms lead to mechanically induced IVD degeneration. Lumbar caprine IVDs (n = 175) were cultured 7, 14 and 21 days under simulated-physiological loading (control), high dynamic or high static loading. Axial deformation and stiffness were continuously measured. Cell viability, cell density, and gene expression were assessed in the nucleus, inner- and outer annulus. The extracellular matrix (ECM) was analyzed for water, glycosaminoglycan and collagen content. IVD height loss and changes in axial deformation were gradual with dynamic and acute with static overloading. Dynamic overloading caused cell death in all IVD regions, whereas static overloading mostly affected the outer annulus. IVDs expression of catabolic and inflammation-related genes was up-regulated directly, whereas loss of water and glycosaminoglycan were significant only after 21 days. Static and dynamic overloading both induced pathological changes to caprine lumbar IVDs within 21 days. The mechanism by which they inflict biomechanical, cellular, and extracellular changes to the nucleus and annulus differed. The described cascades provide leads for the development of new pharmacological and rehabilitative therapies to halt the progression of DDD. PMID:23638074

  10. Drugs preventing Na+ and Ca2+ overload.

    PubMed

    Ravens, U; Himmel, H M

    1999-03-01

    Cardiac intracellular Na+and Ca2+homeostasis is regulated by the concerted action of ion channels, pumps and exchangers. The Na+, K+-ATPase produces the electrochemical concentration gradient for Na+, which is the driving force for Ca2+removal from the cytosol via the Na+/Ca2+exchange. Reduction of this gradient by increased intracellular Na+concentration leads to cellular Ca2+overload resulting in arrhythmias and contractile dysfunction. Na+and Ca2+overload-associated arrhythmias can be produced experimentally by inhibition of Na+efflux (digitalis-induced intoxication) and by abnormal Na+influx via modulated Na+channels (veratridine, DPI 201-106; hypoxia) or via the Na+, H+exchanger. Theoretically, blockers of Na+and Ca2+channels, inhibitors of abnormal oscillatory release of Ca2+from internal stores or modulators of the Na+, Ca2+and Na+, H+exchanger activities could protect against cellular Na+and Ca2+overload. Three exemplary drugs that prevent Na+and Ca2+overload, i.e. the benzothiazolamine R56865, the methylenephenoxydioxy-derivative CP-060S, and the benzoyl-guanidine Hoe 642, a Na+, H+exchange blocker, are briefly reviewed with respect to their efficacy on digitalis-, veratridine- and ischaemia/reperfusion-induced arrhythmias. PMID:10094840

  11. Prooxidant Mechanisms in Iron Overload Cardiomyopathy

    PubMed Central

    Cheng, Ching-Feng; Lian, Wei-Shiung

    2013-01-01

    Iron overload cardiomyopathy (IOC), defined as the presence of systolic or diastolic cardiac dysfunction secondary to increased deposition of iron, is emerging as an important cause of heart failure due to the increased incidence of this disorder seen in thalassemic patients and in patients of primary hemochromatosis. At present, although palliative treatment by regular iron chelation was recommended; whereas IOC is still the major cause for mortality in patient with chronic heart failure induced by iron-overloading. Because iron is a prooxidant and the associated mechanism seen in iron-overload heart is still unclear; therefore, we intend to delineate the multiple signaling pathways involved in IOC. These pathways may include organelles such as calcium channels, mitochondria; paracrine effects from both macrophages and fibroblast, and novel mediators such as thromboxane A2 and adiponectin; with increased oxidative stress and inflammation found commonly in these signaling pathways. With further understanding on these complex and inter-related molecular mechanisms, we can propose potential therapeutic strategies to ameliorate the cardiac toxicity induced by iron-overloading. PMID:24350287

  12. Prooxidant mechanisms in iron overload cardiomyopathy.

    PubMed

    Cheng, Ching-Feng; Lian, Wei-Shiung

    2013-01-01

    Iron overload cardiomyopathy (IOC), defined as the presence of systolic or diastolic cardiac dysfunction secondary to increased deposition of iron, is emerging as an important cause of heart failure due to the increased incidence of this disorder seen in thalassemic patients and in patients of primary hemochromatosis. At present, although palliative treatment by regular iron chelation was recommended; whereas IOC is still the major cause for mortality in patient with chronic heart failure induced by iron-overloading. Because iron is a prooxidant and the associated mechanism seen in iron-overload heart is still unclear; therefore, we intend to delineate the multiple signaling pathways involved in IOC. These pathways may include organelles such as calcium channels, mitochondria; paracrine effects from both macrophages and fibroblast, and novel mediators such as thromboxane A2 and adiponectin; with increased oxidative stress and inflammation found commonly in these signaling pathways. With further understanding on these complex and inter-related molecular mechanisms, we can propose potential therapeutic strategies to ameliorate the cardiac toxicity induced by iron-overloading. PMID:24350287

  13. Performance During the Stress of Processing Overload.

    ERIC Educational Resources Information Center

    Martin, David W.

    Performance becomes degraded when the human processing system undergoes the stress of processing overload. Information processing models are often used to predict how performance will be affected. Single channel models hypothesize that information will either be lost in the queue or processed with delay. Single capacity models predict that for a…

  14. Acute Effects of Static Stretching, Dynamic Exercises, and High Volume Upper Extremity Plyometric Activity on Tennis Serve Performance

    PubMed Central

    Gelen, Ertugrul; Dede, Muhittin; Bingul, Bergun Meric; Bulgan, Cigdem; Aydin, Mensure

    2012-01-01

    The purpose of this study was to compare the acute effects of static stretching; dynamic exercises and high volume upper extremity plyometric activity on tennis serve performance. Twenty-six elite young tennis players (15.1 ± 4.2 years, 167.9 ± 5.8 cm and 61.6 ± 8.1 kg) performed 4 different warm-up (WU) routines in a random order on non-consecutive days. The WU methods consisted of traditional WU (jogging, rally and serve practice) (TRAD); traditional WU and static stretching (TRSS); traditional WU and dynamic exercise (TRDE); and traditional WU and high volume upper extremity plyometric activity (TRPLYP). Following each WU session, subjects were tested on a tennis serve ball speed test. TRAD, TRSS, TRDE and TRPLYO were compared by repeated measurement analyses of variance and post-hoc comparisons. In this study a 1 to 3 percent increase in tennis serve ball speed was recorded in TRDE and TRPLYO when compared to TRAD (p< 0.05). However, no significant change in ball speed performance between TRSS and TRAD. (p> 0.05). ICCs for ball speed showed strong reliability (0.82 to 0.93) for the ball speed measurements.The results of this study indicate that dynamic and high volume upper extremity plyometric WU activities are likely beneficial to serve speed of elite junior tennis players. Key points After the traditional warm up in tennis, static stretching has no effect on serve speed. Tennis players should perform dynamic exercises and/or high volume upper extremity plyometric activities to improve their athletic performance. PMID:24150068

  15. Determinants of acute mortality of Hippodamia convergens (Coleoptera: Coccinellidae) to ultra-low volume permethrin used for mosquito management

    PubMed Central

    Preftakes, Collin J.; Bodin, Jennifer L.; Brown, Christopher R.; Piccolomini, Alyssa M.; Schleier, Jerome J.

    2016-01-01

    There are relatively few experimental studies and risk assessments of the effects on non-target insects from ultra-low volume (ULV) insecticides used for management of adult mosquitoes. Therefore, we evaluated factors that may influence the ability of an insect to intercept the insecticide at the time of application by using Hippodamia convergens (Coleoptera: Coccinellidae) in field bioassay experiments in 2011 and 2015. Treatment factors included different distances, two cage heights (ground-level and 1.5 m above ground) to the point of the application, and covered vs. uncovered cage faces (2015 only). Insecticides used included a water-based formulation (Aqua-Reslin®) and an oil-based formulation (Permanone® 30-30) of permethrin. Cage height was highly significant both years, with much less acute (i.e., short-term exposure) mortality at ground-level compared with 1.5 m. In 2011, acute mortality was less at ground-level (mean = 3.2%, median = 0%) compared to 1.5 m (mean = 85.2%, median = 100%). Cage type also was highly significant, with less mortality in covered cages compared to uncovered cages. Mortality by cage height and cage type was as follows: ground level, covered cage (mean = 2.8%, median = 0.1%); ground level, uncovered cage (mean = 41.9%, median = 9.6%); 1.5 m, covered cage (mean = 6.8%, median = 0%); 1.5 m, uncovered cage (mean = 83.7%, median = 100%). Results suggest that acute mortality to non-target insects may vary considerably based on their height and their ability to directly intercept the insecticide as the aerosol passes through the area being sprayed. PMID:27366655

  16. Dose-Volume Effects on Patient-Reported Acute Gastrointestinal Symptoms During Chemoradiation Therapy for Rectal Cancer

    SciTech Connect

    Chen, Ronald C.; Mamon, Harvey J.; Ancukiewicz, Marek; Killoran, Joseph H.; Crowley, Elizabeth M.; Blaszkowsky, Lawrence S.; Wo, Jennifer Y.; Ryan, David P.; Hong, Theodore S.

    2012-07-15

    Purpose: Research on patient-reported outcomes (PROs) in rectal cancer is limited. We examined whether dose-volume parameters of the small bowel and large bowel were associated with patient-reported gastrointestinal (GI) symptoms during 5-fluorouracil (5-FU)-based chemoradiation treatment for rectal cancer. Methods and Materials: 66 patients treated at the Brigham and Women's Hospital or Massachusetts General Hospital between 2006 and 2008 were included. Weekly during treatment, patients completed a questionnaire assessing severity of diarrhea, urgency, pain, cramping, mucus, and tenesmus. The association between dosimetric parameters and changes in overall GI symptoms from baseline through treatment was examined by using Spearman's correlation. Potential associations between these parameters and individual GI symptoms were also explored. Results: The amount of small bowel receiving at least 15 Gy (V15) was significantly associated with acute symptoms (p = 0.01), and other dosimetric parameters ranging from V5 to V45 also trended toward association. For the large bowel, correlations between dosimetric parameters and overall GI symptoms at the higher dose levels from V25 to V45 did not reach statistical significance (p = 0.1), and a significant association was seen with rectal pain from V15 to V45 (p < 0.01). Other individual symptoms did not correlate with small bowel or large bowel dosimetric parameters. Conclusions: The results of this study using PROs are consistent with prior studies with physician-assessed acute toxicity, and they identify small bowel V15 as an important predictor of acute GI symptoms during 5-FU-based chemoradiation treatment. A better understanding of the relationship between radiation dosimetric parameters and PROs may allow physicians to improve radiation planning to optimize patient outcomes.

  17. 30 CFR 57.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Trailing cable overload protection. 57.12003... Electricity Surface and Underground § 57.12003 Trailing cable overload protection. Individual overload protection or short circuit protection shall be provided for the trailing cables of mobile equipment....

  18. 30 CFR 57.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Trailing cable overload protection. 57.12003... Electricity Surface and Underground § 57.12003 Trailing cable overload protection. Individual overload protection or short circuit protection shall be provided for the trailing cables of mobile equipment....

  19. 30 CFR 57.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Trailing cable overload protection. 57.12003... Electricity Surface and Underground § 57.12003 Trailing cable overload protection. Individual overload protection or short circuit protection shall be provided for the trailing cables of mobile equipment....

  20. 30 CFR 57.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Trailing cable overload protection. 57.12003... Electricity Surface and Underground § 57.12003 Trailing cable overload protection. Individual overload protection or short circuit protection shall be provided for the trailing cables of mobile equipment....

  1. 30 CFR 57.12001 - Circuit overload protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit overload protection. 57.12001 Section... Electricity Surface and Underground § 57.12001 Circuit overload protection. Circuits shall be protected against excessive overloads by fuses or circuit breakers of the correct type and capacity....

  2. Mugineic acid, active ingredient of wheat grass: an oral novel hexadentate iron chelator in iron overloaded diseases.

    PubMed

    Das, Priyabrata; Mukhopadhyay, Soma; Kumar Sarkar, Nirmal; Mandal, Suvra; Kar, Manoj; Mukhopadhyay, Ashis

    2016-09-01

    Iron chelation therapies are required for the treatment of iron overloaded patients; nonetheless, their side effects are also well known. We have evaluated iron-chelating activity of wheat grass extract (WHE) and its purified compound, mugineic acid in murine model with phenylhydrazine (PHZ) and dextran induced acute and chronic iron overload conditions. PHZ and dextran treatment induced acute and chronic iron overload condition in mice, respectively, as indicated by increased serum and tissue iron in both cases. Iron overload was also accompanied with haemosiderosis in tissues (liver and spleen). These PHZ and dextran -: treated mice were orally treated with either crude WHE or purified mugineic acid. The efficacy of mugineic acid and WHE was compared with the potent oral iron chelator ICL670 (Exjade). PHZ and dextran treatment followed by oral administration of WHE or mugineic acid significantly checked the rise of serum/plasma levels of iron as well as tissue iron and also, haemosiderosis in tissues. The results are highly comparable with known iron chelator ICL670. WHE and purified mugineic acid, both seem to have significant prospect to be the cheap, non-toxic, hexadentate and oral therapeutic agents to prevent or alleviate toxic iron overload in patients. PMID:27008864

  3. Effect of anabolic steroids on overloaded and overloaded suspended skeletal muscle

    NASA Technical Reports Server (NTRS)

    Tsika, R. W.; Herrick, R. E.; Baldwin, K. M.

    1987-01-01

    The effect of treatment with an anabolic steroid (nandrolone decanoate) on the muscle mass, the subcellular protein content, and the myosin patterns of normal overloaded and suspended overloaded plantaris muscle in female rat was investigated, dividing rats into six groups: normal control (NC), overload (OV), OV steroid (OV-S), normal suspended (N-sus), OV suspended (OV-sus), and OV suspended steroid (OV-sus-S). Relative to control values, overload produced a sparing effect on the muscle weight of the OV-sus group as well as increases of muscle weight of the OV group; increased protein content; and an increased expression of slow myosin in both OV and OV-sus groups. Steroid treatment of OV animals did not after the response of any parameter analyzed for the OV group, but in the OV-sus group steroid treatment induced increases in muscle weight and in protein content of the OV-sus-S group. The treatment did not alter the pattern of isomyosin expression observed in the OV or the OV-sus groups. These result suggest that the steroid acts synergistically with functional overload only under conditions in which the effect of overload is minimized by suspension.

  4. Dose-Volume Relationships for Acute Bowel Toxicity in Patients Treated With Pelvic Nodal Irradiation for Prostate Cancer

    SciTech Connect

    Fiorino, Claudio Alongi, Filippo; Perna, Lucia; Broggi, Sara; Cattaneo, Giovanni Mauro; Cozzarini, Cesare; Di Muzio, Nadia; Fazio, Ferruccio; Calandrino, Riccardo

    2009-09-01

    Purpose: To find correlation between dose-volume histograms (DVHs) of the intestinal cavity (IC) and moderate-severe acute bowel toxicity in men with prostate cancer treated with pelvic nodal irradiation. Methods and Materials: The study group consisted of 191 patients with localized prostate cancer who underwent whole-pelvis radiotherapy with radical or adjuvant/salvage intent during January 2004 to November 2007. Complete planning/clinical data were available in 175 of these men, 91 of whom were treated with a conventional four-field technique (50.4 Gy, 1.8 Gy/fraction) and 84 of whom were treated with IMRT using conventional Linac (n = 26, 50.4 Gy, 1.8 Gy/fraction) or Helical TomoTherapy (n = 58, 50-54 Gy, 1.8-2 Gy/fraction). The IC outside the planning target volume (PTV) was contoured and the DVH for the first 6 weeks of treatment was recovered in all patients. The correlation between a number of clinical and DVH (V10-V55) variables and toxicity was investigated in univariate and multivariate analyses. The correlation between DVHs for the IC outside the PTV and DVHs for the whole IC was also assessed. Results: Twenty-two patients experienced toxicity (3/22 in the IMRT/tomotherapy group). Univariate analyses showed a significant correlation between V20-V50 and toxicity (p = 0.0002-0.001), with a higher predictive value observed for V40-V50. Previous prostatectomy (p = 0.066) and abdominal/pelvic surgery (p = 0.12) also correlated with toxicity. Multivariate analysis that included V45, abdominal/pelvic surgery, and prostatectomy showed that the most predictive parameters were V45 (p = 0.002) and abdominal/pelvic surgery (p = 0.05, HR = 2.4) Conclusions: Our avoidance IMRT approach drastically reduces the incidence of acute bowel toxicity. V40-V50 of IC and, secondarily, previous abdominal/pelvic surgery were the main predictors of acute bowel toxicity.

  5. Minimally invasive aortic banding in mice: effects of altered cardiomyocyte insulin signaling during pressure overload.

    PubMed

    Hu, Ping; Zhang, Dongfang; Swenson, LeAnne; Chakrabarti, Gopa; Abel, E Dale; Litwin, Sheldon E

    2003-09-01

    We developed a minimally invasive method for producing left ventricular (LV) pressure overload in mice. With the use of this technique, we quickly and reproducibly banded the transverse aorta with low surgical morbidity and mortality. Minimally invasive transverse aortic banding (MTAB) acutely and chronically increased LV systolic pressure, increased heart weight-to-body weight ratio, and induced myocardial fibrosis. We used this technique to determine whether reduced insulin signaling in the heart altered the cardiac response to pressure overload. Mice with cardiac myocyte-restricted knockout of the insulin receptor (CIRKO) have smaller hearts than wild-type (WT) controls. Four weeks after MTAB, WT and CIRKO mice had comparably increased LV systolic pressure, increased cardiac mass, and induction of mRNA for beta-myosin heavy chain and atrial natriuretic factor. However, CIRKO hearts were more dilated, had depressed LV systolic function by echocardiography, and had greater interstitial fibrosis than WT mice. Expression of connective tissue growth factor was increased in banded CIRKO hearts compared with WT hearts. Thus lack of insulin signaling in the heart accelerates the transition to a more decompensated state during cardiac pressure overload. The use of the MTAB approach should facilitate the study of the pathophysiology and treatment of pressure-overload hypertrophy. PMID:12738623

  6. Cardiac myocyte follistatin-like 1 functions to attenuate hypertrophy following pressure overload.

    PubMed

    Shimano, Masayuki; Ouchi, Noriyuki; Nakamura, Kazuto; van Wijk, Bram; Ohashi, Koji; Asaumi, Yasuhide; Higuchi, Akiko; Pimentel, David R; Sam, Flora; Murohara, Toyoaki; van den Hoff, Maurice J B; Walsh, Kenneth

    2011-10-25

    Factors secreted by the heart, referred to as "cardiokines," have diverse actions in the maintenance of cardiac homeostasis and remodeling. Follistatin-like 1 (Fstl1) is a secreted glycoprotein expressed in the adult heart and is induced in response to injurious conditions that promote myocardial hypertrophy and heart failure. The aim of this study was to investigate the role of cardiac Fstl1 in the remodeling response to pressure overload. Cardiac myocyte-specific Fstl1-KO mice were constructed and subjected to pressure overload induced by transverse aortic constriction (TAC). Although Fstl1-KO mice displayed no detectable baseline phenotype, TAC led to enhanced cardiac hypertrophic growth and a pronounced loss in ventricular performance by 4 wk compared with control mice. Conversely, mice that acutely or chronically overexpressed Fstl1 were resistant to pressure overload-induced hypertrophy and cardiac failure. Fstl1-deficient mice displayed a reduction in TAC-induced AMP-activated protein kinase (AMPK) activation in heart, whereas Fstl1 overexpression led to increased myocardial AMPK activation under these conditions. In cultured neonatal cardiomyocytes, administration of Fstl1 promoted AMPK activation and antagonized phenylephrine-induced hypertrophy. Inhibition of AMPK attenuated the antihypertrophic effect of Fstl1 treatment. These results document that cardiac Fstl1 functions as an autocrine/paracrine regulatory factor that antagonizes myocyte hypertrophic growth and the loss of ventricular performance in response to pressure overload, possibly through a mechanism involving the activation of the AMPK signaling axis. PMID:21987816

  7. Role of atrial natriuretic peptide in systemic responses to acute isotonic volume expansion

    NASA Technical Reports Server (NTRS)

    Watenpaugh, Donald E.; Yancy, Clyde W.; Buckey, Jay C.; Lane, Lynda D.; Hargens, Alan R.; Blomqvist, C. G.

    1992-01-01

    A hypothesis is proposed that a temporal relationship exists between increases in cardiac filling pressure and plasma artrial natriuretic peptide (ANP) concentration and also between ANP elevation and vasodilation, fluid movement from plasma to interstitium, and increased urine volume (UV). To test the hypothesis, 30 ml/kg isotonic saline were infused in supine male subjects over 24 min and responses were monitored for 3 h postinfusion. Results show that at end infusion, mean arterial pressure (RAP), heart rate and plasma volume exhibited peak increases of 146, 23, and 27 percent, respectively. Mean plasma ANP and UV peaked (45 and 390 percent, respectively) at 30 min postinfusion. Most cardiovascular variables had returned toward control levels by 1 h postinfusion, and net reabsorption of extravascular fluid ensued. It is concluded that since ANP was not significantly increased until 30 min postinfusion, factors other than ANP initiate responses to intravascular fluid loading. These factors include increased vascular pressures, baroreceptor-mediated vasolidation, and hemodilution of plasma proteins. ANP is suggested to mediate, in part, the renal response to saline infusion.

  8. Valgus Extension Overload in Baseball Players.

    PubMed

    Paulino, Franklin E; Villacis, Diego C; Ahmad, Christopher S

    2016-01-01

    Repetitive throwing, such as in baseball pitching, applies massive stress on the elbow. This can often lead to a predictable constellation of elbow injuries, such as valgus extension overload syndrome (VEO). The following review of VEO provides an understanding of relevant anatomy, explanation of pathomechanics, key aspects to clinical evaluation, effective treatment options, and indications for surgery. In addition, we provide the senior author's (CSA) preferred arthroscopic technique for cases of VEO refractory to conservative management. PMID:26991567

  9. Information overload in the teaching of pharmacology.

    PubMed

    Achike, F I; Ogle, C W

    2000-02-01

    Medical students are usually drawn from the best of students, but it is not unusual to see these brilliant students fail their exams or even dismissed from medical school because of poor academic performance. Information overload has been recognized as one of the major contributing factors to this problem. The situation is expected to get worse, with the ever-present technology-induced exponential growth in information. In discussing this issue, the authors echo the concerns of several experts regarding the content overload of medical school curricula, particularly in pharmacology. It is the increasing awareness of this problem that led the Association of American Medical Colleges and the General Medical Council of Britain to promote the concept of a core curriculum for each of the principal disciplines in medicine. Several medical schools have adopted the concept and also the problem-based learning approach, which focuses on ameliorating the complex problems associated with information growth in medical education. Based on the authors' experience as medical students, medical practitioners, and pharmacology teachers, they discuss the factors that contribute to information overload, from psychological and nonpsychological perspectives. Issues such as the design and structure of the curriculum, the quality of training and effectiveness of the teachers (clinically qualified vs. nonclinically qualified teachers), and the psychological preparedness of the students are discussed. The authors make suggestions for improvement. PMID:10664924

  10. Blood volume of nonsplenectomized and splenectomized cats before and after acute hemorrhage

    SciTech Connect

    Breznock, E.M.; Strack, D.

    1982-10-01

    Blood volume (BV) was determined in awake, nonsplenectomized (NSPX) and splenectomized (SPX) cats before and after hemorrhage (6 ml/kg). Each NSPX cat had a determined BV at least 10 ml/kg greater than the same cat after splenectomy. The mean BV of SPX cats was 43.4 +/- 8.94. ml kg (4.3% of body weight). The calculated RBC masses of NSPX and SPX cats were 17.0 +/- 4.07 and 12.2 +/- 1.12 ml/kg, respectively. Each NSPX cat had apparent RBC masses of 5 ml/kg greater than that of the same cat after splenectomy was done. At 1 hour after a hemorrhage, the BV and RBC masses determined in SPX cats were 46.7 +/- 12.1 and 9.7 +/- 1.90 ml/kg, respectively. Extravascular-to-intravascular fluid flux (calculated from RBC masses and plasma protein dilution) was approximately 0.80% of body weight. The indirect method with /sup 51/Cr-labeled RBC for BV determination was accurate and precise in awake, SPX cats; in awake, NSPX cats, the /sup 51/Cr-labeled RBC dilution method was precise, but not accurate. The spleen in the cat resulted in marked overestimations of BV and RBC masses.

  11. Improvement of Oxygenation in Severe Acute Respiratory Distress Syndrome With High-Volume Continuous Veno-venous Hemofiltration

    PubMed Central

    Yang, Wenmin; Hong, Jie; Zeng, Qiyi; Tao, Jianping; Chen, Feiyan; Dang, Run; Liang, Yufeng; Wu, Zhiyuan; Yang, Yiyu

    2016-01-01

    The efficacy and therapeutic mechanisms of continuous renal replacement therapy (CRRT) for improvement of oxygenation in acute respiratory distress syndrome (ARDS) remain controversial. These questions were addressed by retrospective analysis of severe ARDS patients admitted to the pediatric intensive care unit of our hospital from 2009 to 2015 who received high-volume continuous veno-venous hemofiltration during mechanical ventilation. There was a significant improvement in partial oxygen pressure/fraction of inspired oxygen (PaO2/FiO2) 24 hours after CRRT onset compared with baseline (median change = 51.5; range = −19 to 450.5; P < .001) as well as decreases in FiO2, peak inspiratory pressure, positive end-expiratory pressure, and mean airway pressure (P < .05). The majority of patients had a negative fluid balance after 24 hours of CRRT. White blood cell (WBC) count decreased in the subgroup with high baseline WBC count (P < .05). PaO2/FiO2 was higher in ARDS patients with extrapulmonary etiology than in those with pulmonary etiology (P < .05). Improvement in oxygenation is likely related to both restoration of fluid balance and clearance of inflammatory mediators. PMID:27336018

  12. Myocardial fibrosis in nonhuman primate with pressure overload hypertrophy.

    PubMed

    Pick, R; Janicki, J S; Weber, K T

    1989-11-01

    Characteristics of pressure overload hypertrophy are known to include an accumulation of collagen (or fibrosis) and a biochemical remodeling of fibrillar type I and III collagens. The corresponding structural nature of myocardial fibrosis is less clear. This light morphologic study was undertaken to address this issue in the hypertrophied left ventricle of the nonhuman primate with experimental hypertension. For this purpose, the picrosirius red technique and polarization microscopy were used to examine the myocardium during the evolutionary, early, and late phases of established hypertrophy corresponding to 4, 35, and 88 weeks of experimental hypertension. Evidence of increased thin perimysial fiber formation, together with collagen fiber disruption and edema at 4 weeks of hypertrophy, was found when the chamber volume to left ventricular mass ratio was reduced. After 35 weeks, when this ratio was again normal, a greater number of intermuscular spaces contained both thick and thin perimysial fibers. In addition to this interstitial fibrosis, a reactive fibrosis consisting of a meshwork of thick and thin perimysial fibers was seen extending over muscle fibers. Finally, at 88 weeks, this fibrous meshwork had encircled muscle and there now was evidence of cell necrosis. The accompanying replacement fibrosis consisted of yet another distinctive orthogonal grid of thick and thin collagen fibers. Thus, a continuum of fibrillar collagen remodeling was seen in pressure overload hypertrophy in the nonhuman primate myocardium. Structurally distinct patterns of myocardial fibrosis were recognized based on the alignment of perimysial fibers with muscle that may explain the cellular remodeling and altered mechanical behavior of the concentrically hypertrophied myocardium. PMID:2530905

  13. The comparison of stroke volume variation with central venous pressure in predicting fluid responsiveness in septic patients with acute circulatory failure

    PubMed Central

    Angappan, Santhalakshmi; Parida, Satyen; Vasudevan, Arumugam; Badhe, Ashok Shankar

    2015-01-01

    Purpose: The present study was designed to investigate the efficacy of stroke volume variation (SVV) in predicting fluid responsiveness and compare it to traditional measures of volume status assessment like central venous pressure (CVP). Methods: Forty-five mechanically ventilated patients in sepsis with acute circulatory failure. Patients were not included when they had atrial fibrillation, other severe arrhythmias, permanent pacemaker, or needed mechanical cardiac support. Furthermore, excluded were patients with hypoxemia and a CVP >12. Patients received volume expansion in the form of 500 ml of 6% hydroxyethyl starch. Results: The volume expansion-induced increase in  cardiac index (CI) was >15% in 29 patients (labeled responders) and <15% in 16 patients (labeled nonresponders). Before volume expansion, SVV was higher in responders than in nonresponders. Receiver operating characteristic curves analysis showed that SVV was a more accurate indicator of fluid responsiveness than CVP. Before volume expansion, an SVV value of 13% allowed discrimination between responders and nonresponders with a sensitivity of 78% and a specificity of 89%. Volume expansion-induced changes in CI weakly and positively correlated with SVV before volume expansion. Volume expansion decreased SVV from 18.86 ± 4.35 to 7.57 ± 1.80 and volume expansion-induced changes in SVV moderately correlated with volume expansion-induced changes in CI. Conclusions: When predicting fluid responsiveness in mechanically ventilated patients in septic shock, SVV is more effective than CVP. Nevertheless, the overall correlation of baseline SVV with increases in CI remains poor. Trends in SVV, as reflected by decreases with volume replacement, seem to correlate much better with increases in CI. PMID:26180432

  14. Mathematical modelling to centre low tidal volumes following acute lung injury: A study with biologically variable ventilation

    PubMed Central

    Graham, M Ruth; Haberman, Craig J; Brewster, John F; Girling, Linda G; McManus, Bruce M; Mutch, W Alan C

    2005-01-01

    Background With biologically variable ventilation [BVV – using a computer-controller to add breath-to-breath variability to respiratory frequency (f) and tidal volume (VT)] gas exchange and respiratory mechanics were compared using the ARDSNet low VT algorithm (Control) versus an approach using mathematical modelling to individually optimise VT at the point of maximal compliance change on the convex portion of the inspiratory pressure-volume (P-V) curve (Experimental). Methods Pigs (n = 22) received pentothal/midazolam anaesthesia, oleic acid lung injury, then inspiratory P-V curve fitting to the four-parameter logistic Venegas equation F(P) = a + b[1 + e-(P-c)/d]-1 where: a = volume at lower asymptote, b = the vital capacity or the total change in volume between the lower and upper asymptotes, c = pressure at the inflection point and d = index related to linear compliance. Both groups received BVV with gas exchange and respiratory mechanics measured hourly for 5 hrs. Postmortem bronchoalveolar fluid was analysed for interleukin-8 (IL-8). Results All P-V curves fit the Venegas equation (R2 > 0.995). Control VT averaged 7.4 ± 0.4 mL/kg as compared to Experimental 9.5 ± 1.6 mL/kg (range 6.6 – 10.8 mL/kg; p < 0.05). Variable VTs were within the convex portion of the P-V curve. In such circumstances, Jensen's inequality states "if F(P) is a convex function defined on an interval (r, s), and if P is a random variable taking values in (r, s), then the average or expected value (E) of F(P); E(F(P)) > F(E(P))." In both groups the inequality applied, since F(P) defines volume in the Venegas equation and (P) pressure and the range of VTs varied within the convex interval for individual P-V curves. Over 5 hrs, there were no significant differences between groups in minute ventilation, airway pressure, blood gases, haemodynamics, respiratory compliance or IL-8 concentrations. Conclusion No difference between groups is a consequence of BVV occurring on the convex interval

  15. Transfusion associated circulatory overload: a critical incident.

    PubMed

    Goodall, E

    2014-01-01

    Transfusion associated circulatory overload (TACO) is a serious but under-recognised complication of blood transfusion. While the exact incidence rate is unknown the associated morbidity and mortality make this a transfusion reaction worthy of attention. This article provides details of a critical incident involving TACO followed by a literature review and discussion written from the perspective of a student ODP. The goal of this article is to raise awareness of TACO amongst hospital staff to facilitate faster recognition and earlier intervention in future events. PMID:24516967

  16. Fibre-Specific Responses to Endurance and Low Volume High Intensity Interval Training: Striking Similarities in Acute and Chronic Adaptation

    PubMed Central

    Scribbans, Trisha D.; Edgett, Brittany A.; Vorobej, Kira; Mitchell, Andrew S.; Joanisse, Sophie D.; Matusiak, Jennifer B. L.; Parise, Gianni; Quadrilatero, Joe; Gurd, Brendon J.

    2014-01-01

    The current study involved the completion of two distinct experiments. Experiment 1 compared fibre specific and whole muscle responses to acute bouts of either low-volume high-intensity interval training (LV-HIT) or moderate-intensity continuous endurance exercise (END) in a randomized crossover design. Experiment 2 examined the impact of a six-week training intervention (END or LV-HIT; 4 days/week), on whole body and skeletal muscle fibre specific markers of aerobic and anaerobic capacity. Six recreationally active men (Age: 20.7±3.8 yrs; VO2peak: 51.9±5.1 mL/kg/min) reported to the lab on two separate occasions for experiment 1. Following a muscle biopsy taken in a fasted state, participants completed an acute bout of each exercise protocol (LV-HIT: 8, 20-second intervals at ∼170% of VO2peak separated by 10 seconds of rest; END: 30 minutes at ∼65% of VO2peak), immediately followed by a muscle biopsy. Glycogen content of type I and IIA fibres was significantly (p<0.05) reduced, while p-ACC was significantly increased (p<0.05) following both protocols. Nineteen recreationally active males (n = 16) and females (n = 3) were VO2peak-matched and assigned to either the LV-HIT (n = 10; 21±2 yrs) or END (n = 9; 20.7±3.8 yrs) group for experiment 2. After 6 weeks, both training protocols induced comparable increases in aerobic capacity (END: Pre: 48.3±6.0, Mid: 51.8±6.0, Post: 55.0±6.3 mL/kg/min LV-HIT: Pre: 47.9±8.1, Mid: 50.4±7.4, Post: 54.7±7.6 mL/kg/min), fibre-type specific oxidative and glycolytic capacity, glycogen and IMTG stores, and whole-muscle capillary density. Interestingly, only LV-HIT induced greater improvements in anaerobic performance and estimated whole-muscle glycolytic capacity. These results suggest that 30 minutes of END exercise at ∼65% VO2peak or 4 minutes of LV-HIT at ∼170% VO2peak induce comparable changes in the intra-myocellular environment (glycogen content and signaling activation); correspondingly, training

  17. Dietary fat overload reprograms brown fat mitochondria.

    PubMed

    Lettieri Barbato, Daniele; Tatulli, Giuseppe; Vegliante, Rolando; Cannata, Stefano M; Bernardini, Sergio; Ciriolo, Maria R; Aquilano, Katia

    2015-01-01

    Chronic nutrient overload accelerates the onset of several aging-related diseases reducing life expectancy. Although the mechanisms by which overnutrition affects metabolic processes in many tissues are known, its role on BAT physiology is still unclear. Herein, we investigated the mitochondrial responses in BAT of female mice exposed to high fat diet (HFD) at different steps of life. Although adult mice showed an unchanged mitochondrial amount, both respiration and OxPHOS subunits were strongly affected. Differently, offspring pups exposed to HFD during pregnancy and lactation displayed reduced mitochondrial mass but high oxidative efficiency that, however, resulted in increased bioenergetics state of BAT rather than augmented uncoupling respiration. Interestingly, the metabolic responses triggered by HFD were accompanied by changes in mitochondrial dynamics characterized by decreased content of the fragmentation marker Drp1 both in mothers and offspring pups. HFD-induced inactivation of the FoxO1 transcription factor seemed to be the up-stream modulator of Drp1 levels in brown fat cells. Furthermore, HFD offspring pups weaned with normal diet only partially reverted the mitochondrial dysfunctions caused by HFD. Finally these mice failed in activating the thermogenic program upon cold exposure. Collectively our findings suggest that maternal dietary fat overload irreversibly commits BAT unresponsiveness to physiological stimuli such as cool temperature and this dysfunction in the early stage of life might negatively modulate health and lifespan. PMID:26483700

  18. Dietary fat overload reprograms brown fat mitochondria

    PubMed Central

    Lettieri Barbato, Daniele; Tatulli, Giuseppe; Vegliante, Rolando; Cannata, Stefano M.; Bernardini, Sergio; Ciriolo, Maria R.; Aquilano, Katia

    2015-01-01

    Chronic nutrient overload accelerates the onset of several aging-related diseases reducing life expectancy. Although the mechanisms by which overnutrition affects metabolic processes in many tissues are known, its role on BAT physiology is still unclear. Herein, we investigated the mitochondrial responses in BAT of female mice exposed to high fat diet (HFD) at different steps of life. Although adult mice showed an unchanged mitochondrial amount, both respiration and OxPHOS subunits were strongly affected. Differently, offspring pups exposed to HFD during pregnancy and lactation displayed reduced mitochondrial mass but high oxidative efficiency that, however, resulted in increased bioenergetics state of BAT rather than augmented uncoupling respiration. Interestingly, the metabolic responses triggered by HFD were accompanied by changes in mitochondrial dynamics characterized by decreased content of the fragmentation marker Drp1 both in mothers and offspring pups. HFD-induced inactivation of the FoxO1 transcription factor seemed to be the up-stream modulator of Drp1 levels in brown fat cells. Furthermore, HFD offspring pups weaned with normal diet only partially reverted the mitochondrial dysfunctions caused by HFD. Finally these mice failed in activating the thermogenic program upon cold exposure. Collectively our findings suggest that maternal dietary fat overload irreversibly commits BAT unresponsiveness to physiological stimuli such as cool temperature and this dysfunction in the early stage of life might negatively modulate health and lifespan. PMID:26483700

  19. [Chronic nicotinamide overload and type 2 diabetes].

    PubMed

    Zhou, Shi-Sheng; Li, Da; Zhou, Yi-Ming; Sun, Wu-Ping; Liu, Xing-Xing; Lun, Yong-Zhi

    2010-02-25

    Type 2 diabetes is a major global health problem. It is generally accepted that type 2 diabetes is the result of gene-environmental interaction. However, the mechanism underlying the interaction is unclear. Diet change is known to play an important role in type 2 diabetes. The fact that the global high prevalence of type 2 diabetes has occurred following the spread of food fortification worldwide suggests a possible involvement of excess niacin intake. Our recent study found that nicotinamide overload and low nicotinamide detoxification may induce oxidative stress associated with insulin resistance. Based on the relevant facts, this review briefly summarized the relationship between the prevalence of type 2 diabetes and the nicotinamide metabolism changes induced by excess niacin intake, aldehyde oxidase inhibitors, liver diseases and functional defects of skin. We speculate that the gene-environmental interaction in type 2 diabetes may be a reflection of the outcome of the association of chronic nicotinamide overload-induced toxicity and the relatively low detoxification/excretion capacity of the body. Reducing the content of niacin in foods may be a promising strategy for the control of type 2 diabetes. PMID:20179894

  20. Fluid and electrolyte overload in critically ill patients: An overview

    PubMed Central

    Besen, Bruno Adler Maccagnan Pinheiro; Gobatto, André Luiz Nunes; Melro, Lívia Maria Garcia; Maciel, Alexandre Toledo; Park, Marcelo

    2015-01-01

    Fluids are considered the cornerstone of therapy for many shock states, particularly states that are associated with relative or absolute hypovolemia. Fluids are also commonly used for many other purposes, such as renal protection from endogenous and exogenous substances, for the safe dilution of medications and as “maintenance” fluids. However, a large amount of evidence from the last decade has shown that fluids can have deleterious effects on several organ functions, both from excessive amounts of fluids and from their non-physiological electrolyte composition. Additionally, fluid prescription is more common in patients with systemic inflammatory response syndrome whose kidneys may have impaired mechanisms of electrolyte and free water excretion. These processes have been studied as separate entities (hypernatremia, hyperchloremic acidosis and progressive fluid accumulation) leading to worse outcomes in many clinical scenarios, including but not limited to acute kidney injury, worsening respiratory function, higher mortality and higher hospital and intensive care unit length-of-stays. In this review, we synthesize this evidence and describe this phenomenon as fluid and electrolyte overload with potentially deleterious effects. Finally, we propose a strategy to safely use fluids and thereafter wean patients from fluids, along with other caveats to be considered when dealing with fluids in the intensive care unit. PMID:25938027

  1. Accuracy and precision of end-expiratory lung-volume measurements by automated nitrogen washout/washin technique in patients with acute respiratory distress syndrome

    PubMed Central

    2011-01-01

    Introduction End-expiratory lung volume (EELV) is decreased in acute respiratory distress syndrome (ARDS), and bedside EELV measurement may help to set positive end-expiratory pressure (PEEP). Nitrogen washout/washin for EELV measurement is available at the bedside, but assessments of accuracy and precision in real-life conditions are scant. Our purpose was to (a) assess EELV measurement precision in ARDS patients at two PEEP levels (three pairs of measurements), and (b) compare the changes (Δ) induced by PEEP for total EELV with the PEEP-induced changes in lung volume above functional residual capacity measured with passive spirometry (ΔPEEP-volume). The minimal predicted increase in lung volume was calculated from compliance at low PEEP and ΔPEEP to ensure the validity of lung-volume changes. Methods Thirty-four patients with ARDS were prospectively included in five university-hospital intensive care units. ΔEELV and ΔPEEP volumes were compared between 6 and 15 cm H2O of PEEP. Results After exclusion of three patients, variability of the nitrogen technique was less than 4%, and the largest difference between measurements was 81 ± 64 ml. ΔEELV and ΔPEEP-volume were only weakly correlated (r2 = 0.47); 95% confidence interval limits, -414 to 608 ml). In four patients with the highest PEEP (≥ 16 cm H2O), ΔEELV was lower than the minimal predicted increase in lung volume, suggesting flawed measurements, possibly due to leaks. Excluding those from the analysis markedly strengthened the correlation between ΔEELV and ΔPEEP volume (r2 = 0.80). Conclusions In most patients, the EELV technique has good reproducibility and accuracy, even at high PEEP. At high pressures, its accuracy may be limited in case of leaks. The minimal predicted increase in lung volume may help to check for accuracy. PMID:22166727

  2. Liver Enzymes in Children with beta-Thalassemia Major: Correlation with Iron Overload and Viral Hepatitis

    PubMed Central

    Salama, Khaled M.; Ibrahim, Ola M.; Kaddah, Ahmed M.; Boseila, Samia; Ismail, Leila Abu; Hamid, May M. Abdel

    2015-01-01

    BACKGROUND: Beta Thalassemia is the most common chronic hemolytic anemia in Egypt (85.1%) with an estimated carrier rate of 9-10.2%. Injury to the liver, whether acute or chronic, eventually results in an increase in serum concentrations of Alanine transaminase (ALT) and Aspartate transaminase (AST). AIM: Evaluating the potentiating effect of iron overload & viral hepatitis infection on the liver enzymes. PATIENTS AND METHODS: Eighty (80) thalassemia major patients were studied with respect to liver enzymes, ferritin, transferrin saturation, HBsAg, anti-HCV antibody and HCV-PCR for anti-HCV positive patients. RESULTS: Fifty % of the patients were anti-HCV positive and 55% of them were HCV-PCR positive. Patients with elevated ALT and AST levels had significantly higher mean serum ferritin than those with normal levels. Anti-HCV positive patients had higher mean serum ferritin, serum ALT, AST and GGT levels and higher age and duration of blood transfusion than the negative group. HCV-PCR positive patients had higher mean serum ferritin and serum ALT and also higher age and duration of blood transfusion than the negative group. CONCLUSION: Iron overload is a main leading cause of elevated liver enzymes, and presence of HCV infection is significantly related to the increased iron overload. PMID:27275237

  3. Viscoelastic properties of pressure overload hypertrophied myocardium: effect of serine protease treatment

    NASA Technical Reports Server (NTRS)

    Stroud, Jason D.; Baicu, Catalin F.; Barnes, Mary A.; Spinale, Francis G.; Zile, Michael R.

    2002-01-01

    To determine whether and to what extent one component of the extracellular matrix, fibrillar collagen, contributes causally to abnormalities in viscoelasticity, collagen was acutely degraded by activation of endogenous matrix metalloproteinases (MMPs) with the serine protease plasmin. Papillary muscles were isolated from normal cats and cats with right ventricular pressure overload hypertrophy (POH) induced by pulmonary artery banding. Plasmin treatment caused MMP activation, collagen degradation, decreased the elastic stiffness constant, and decreased the viscosity constant in both normal and POH muscles. Thus, whereas many mechanisms may contribute to the abnormalities in myocardial viscoelasticity in the POH myocardium, changes in fibrillar collagen appear to play a predominant role.

  4. Hypocalcemia in acute pancreatitis revisited

    PubMed Central

    Ahmed, Armin; Azim, Afzal; Gurjar, Mohan; Baronia, Arvind Kumar

    2016-01-01

    Hypocalcemia is a frequent finding in acute pancreatitis. Severe hypocalcemia can present with neurological as well as cardiovascular manifestations. Correction of hypocalcemia by parenteral calcium infusion remains a controversial topic as intracellular calcium overload is the central mechanism of acinar cell injury in pancreatitis. The current article deals with the art and science of calcium correction in pancreatitis patients. PMID:27076730

  5. Dysmetabolic hyperferritinemia: all iron overload is not hemochromatosis.

    PubMed

    Makker, Jasbir; Hanif, Ahmad; Bajantri, Bharat; Chilimuri, Sridhar

    2015-01-01

    Disturbances in iron metabolism can be genetic or acquired and accordingly manifest as primary or secondary iron overload state. Organ damage may result from iron overload and manifest clinically as cirrhosis, diabetes mellitus, arthritis, endocrine abnormalities and cardiomyopathy. Hemochromatosis inherited as an autosomal recessive disorder is the most common genetic iron overload disorder. Expert societies recommend screening of asymptomatic and symptomatic individuals with hemochromatosis by obtaining transferrin saturation (calculated as serum iron/total iron binding capacity × 100). Further testing for the hemochromatosis gene is recommended if transferrin saturation is >45% with or without hyperferritinemia. However, management of individuals with low or normal transferrin saturation is not clear. In patients with features of iron overload and high serum ferritin levels, low or normal transferrin saturation should alert the physician to other - primary as well as secondary - causes of iron overload besides hemochromatosis. We present here a possible approach to patients with hyperferritinemia but normal transferrin saturation. PMID:25759633

  6. Impaired hepcidin expression in alpha-1-antitrypsin deficiency associated with iron overload and progressive liver disease.

    PubMed

    Schaefer, Benedikt; Haschka, David; Finkenstedt, Armin; Petersen, Britt-Sabina; Theurl, Igor; Henninger, Benjamin; Janecke, Andreas R; Wang, Chia-Yu; Lin, Herbert Y; Veits, Lothar; Vogel, Wolfgang; Weiss, Günter; Franke, Andre; Zoller, Heinz

    2015-11-01

    Liver disease due to alpha-1-antitrypsin deficiency (A1ATD) is associated with hepatic iron overload in a subgroup of patients. The underlying cause for this association is unknown. The aim of the present study was to define the genetics of this correlation and the effect of alpha-1-antitrypsin (A1AT) on the expression of the iron hormone hepcidin. Full exome and candidate gene sequencing were carried out in a family with A1ATD and hepatic iron overload. Regulation of hepcidin expression by A1AT was studied in primary murine hepatocytes. Cells co-transfected with hemojuvelin (HJV) and matriptase-2 (MT-2) were used as a model to investigate the molecular mechanism of this regulation. Observed familial clustering of hepatic iron overload with A1ATD suggests a genetic cause, but genotypes known to be associated with hemochromatosis were absent. Individuals homozygous for the A1AT Z-allele with environmental or genetic risk factors such as steatosis or heterozygosity for the HAMP non-sense mutation p.Arg59* presented with severe hepatic siderosis. In hepatocytes, A1AT induced hepcidin mRNA expression in a dose-dependent manner. Experiments in overexpressing cells show that A1AT reduces cleavage of the hepcidin inducing bone morphogenetic protein co-receptor HJV via inhibition of the membrane-bound serine protease MT-2. The acute-phase protein A1AT is an inducer of hepcidin expression. Through this mechanism, A1ATD could be a trigger of hepatic iron overload in genetically predisposed individuals or patients with environmental risk factors for hepatic siderosis. PMID:26310624

  7. Prospective study of treatment techniques to minimize the volume of pelvic small bowel with reduction of acute and late effects associated with pelvic irradiation

    SciTech Connect

    Gallagher, M.J.; Brereton, H.D.; Rostock, R.A.; Zero, J.M.; Zekoski, D.A.; Poyss, L.F.; Richter, M.P.; Kligerman, M.M.

    1986-09-01

    The volume, distribution, and mobility of opacified pelvic small bowel (PSB) were determined by fluoroscopy and orthogonal radiographs in 150 consecutive patients undergoing pelvic irradiation. Various techniques including uteropexy, omental transposition, bladder distention, inclining the patient, and anterior abdominal wall compression in the supine and prone treatment position were studied for their effect on the volume and location of small bowel within the pelvis. Abdominal wall compression in the prone position combined with bladder distention was selected for further investigation because of its simplicity, reproducibility, patient comfort, and ability to displace the small bowel. Factors correlating with the volume of pelvic small bowel (PSB) included prior pelvic surgery, pelvic irradiation (XRT), and body mass index. After pelvic surgery, especially following abdominoperineal resection (APR), there was a greater volume of PSB which was also less mobile. The severity of acute gastrointestinal effects positively correlated with the volume of irradiated small bowel. Overall, 67% of patients experienced little or no diarrhea, 30% developed mild diarrhea, and no patient required treatment interruption. Late gastrointestinal effects correlated with the prior pelvic surgery and with the volume of small bowel receiving greater than 45 Gy. Small bowel obstruction was not observed in 75 patients who had no previous pelvic surgery. However, following pelvic surgery excluding APR, 2/50 patients and following APR, 3/25 patients developed small bowel obstruction.

  8. Evaluation of thermal overload in boiler operators.

    PubMed

    Braga, Camila Soares; Rodrigues, Valéria Antônia Justino; Campos, Julio César Costa; de Souza, Amaury Paulo; Minette, Luciano José; de Moraes, Angêlo Casali; Sensato, Guilherme Luciano

    2012-01-01

    The Brazilians educational institutions need a large energy demand for the operation of laundries, restaurants and accommodation of students. Much of that energy comes from steam generated in boilers with wood fuel. The laboral activity in boiler may present problems for the operator's health due to exposure to excessive heat, and its operation has a high degree of risk. This paper describes an analysis made the conditions of thermal environment in the operation of a B category boiler, located at a Higher Education Institution, located in the Zona da Mata Mineira The equipments used to collect data were Meter WBGT of the Heat Index; Meter of Wet Bulb Index and Globe Thermometer (WBGT); Politeste Instruments, an anemometer and an Infrared Thermometer. By the application of questionnaires, the second phase consisted of collecting data on environmental factors (temperature natural environment, globe temperature, relative humidity and air velocity). The study concluded that during the period evaluated, the activity had thermal overload. PMID:22316768

  9. Clinical and Research Considerations for Patients With Hypertensive Acute Heart Failure: A Consensus Statement from the Society of Academic Emergency Medicine and the Heart Failure Society of America Acute Heart Failure Working Group.

    PubMed

    Collins, Sean P; Levy, Phillip D; Martindale, Jennifer L; Dunlap, Mark E; Storrow, Alan B; Pang, Peter S; Albert, Nancy M; Felker, G Michael; Fermann, Gregory J; Fonarow, Gregg C; Givertz, Michael M; Hollander, Judd E; Lanfear, David J; Lenihan, Daniel J; Lindenfeld, JoAnn M; Peacock, W Frank; Sawyer, Douglas B; Teerlink, John R; Butler, Javed

    2016-08-01

    Management approaches for patients in the emergency department (ED) who present with acute heart failure (AHF) have largely focused on intravenous diuretics. Yet, the primary pathophysiologic derangement underlying AHF in many patients is not solely volume overload. Patients with hypertensive AHF (H-AHF) represent a clinical phenotype with distinct pathophysiologic mechanisms that result in elevated ventricular filling pressures. To optimize treatment response and minimize adverse events in this subgroup, we propose that clinical management be tailored to a conceptual model of disease based on these mechanisms. This consensus statement reviews the relevant pathophysiology, clinical characteristics, approach to therapy, and considerations for clinical trials in ED patients with H-AHF. PMID:27262665

  10. Bioaugmentation of overloaded anaerobic digesters restores function and archaeal community.

    PubMed

    Tale, V P; Maki, J S; Zitomer, D H

    2015-03-01

    Adding beneficial microorganisms to anaerobic digesters for improved performance (i.e. bioaugmentation) has been shown to decrease recovery time after organic overload or toxicity upset. Compared to strictly anaerobic cultures, adding aerotolerant methanogenic cultures may be more practical since they exhibit higher methanogenic activity and can be easily dried and stored in ambient air for future shipping and use. In this study, anaerobic digesters were bioaugmented with both anaerobic and aerated, methanogenic propionate enrichment cultures after a transient organic overload. Digesters bioaugmented with anaerobic and moderately aerated cultures recovered 25 and 100 days before non-bioaugmented digesters, respectively. Increased methane production due to bioaugmentation continued a long time, with 50-120% increases 6 to 12 SRTs (60-120 days) after overload. In contrast to the anaerobic enrichment, the aerated enrichments were more effective as bioaugmentation cultures, resulting in faster recovery of upset digester methane and COD removal rates. Sixty days after overload, the bioaugmented digester archaeal community was not shifted, but was restored to one similar to the pre-overload community. In contrast, non-bioaugmented digester archaeal communities before and after overload were significantly different. Organisms most similar to Methanospirillum hungatei had higher relative abundance in well-operating, undisturbed and bioaugmented digesters, whereas organisms similar to Methanolinea tarda were more abundant in upset, non-bioaugmented digesters. Bioaugmentation is a beneficial approach to increase digester recovery rate after transient organic overload events. Moderately aerated, methanogenic propionate enrichment cultures were more beneficial augments than a strictly anaerobic enrichment. PMID:25528544

  11. Metabolic response to subacute and subchronic iron overload in a rat model.

    PubMed

    Adham, Khadiga G; Farhood, Manal H; Daghestani, Maha H; Aleisa, Nadia A; Alkhalifa, Ahlam A; El Amin, Maha H; Virk, Promy; Al-Obeid, Mai A; Al-Humaidhi, Eman M H

    2015-12-01

    One of the common causes of iron overload is excessive iron intake in cases of iron-poor anemia, where iron saccharate complex (ISC) is routinely used to optimize erythropoiesis. However, non-standardized ISC administration could entail the risk of iron overload. To induce iron overload, Wistar rats were intraperitoneally injected with subacute (0.2 mg kg⁻¹) and subchronic (0.1 mg kg⁻¹) overdoses of ISC for 2 and 4 weeks, respectively. Iron status was displayed by an increase in transferrin saturation (up to 332%) and serum and liver iron burden (up to 19.3 μmol L⁻¹ and 13.2 μmol g⁻¹ wet tissue, respectively) together with a drop in total and unsaturated iron binding capacities "TIBC, UIBC" as surrogate markers of transferrin activity. Iron-induced leukocytosis (up to 140%), along with the decline in serum transferrin markers (up to 43%), respectively, mark positive and negative acute phase reactions. Chemical stress was demonstrated by a significant rise (p > 0.05) in indices of the hemogram (erythrocytes, hemoglobin, hematocrit, leukocytes) and stress metabolites [corticosterone (CORT) and lactate]. Yet, potential causes of the unexpected decline in serum activities of ALT, AST and LDH (p > 0.05) might include decreased hepatocellular enzyme production and/or inhibition or reduction of the enzyme activities. The current findings highlight the toxic role of elevated serum and liver iron in initiating erythropoiesis and acute phase reactions, modifying iron status and animal organ function, changing energy metabolism and bringing about accelerated glycolysis and impaired lactate clearance supposedly by decreasing anaerobic threshold and causing premature entering to the anaerobic system. PMID:26616369

  12. Fatigue crack growth with single overload - Measurement and modeling

    NASA Technical Reports Server (NTRS)

    Davidson, D. L.; Hudak, S. J., Jr.; Dexter, R. J.

    1987-01-01

    This paper compares experiments with an analytical model of fatigue crack growth under variable amplitude. The stereoimaging technique was used to measure displacements near the tips of fatigue cracks undergoing simple variations in load amplitude-single overloads and overload/underload combinations. Measured displacements were used to compute strains, and stresses were determined from the strains. Local values of crack driving force (Delta-K effective) were determined using both locally measured opening loads and crack tip opening displacements. Experimental results were compared with simulations made for the same load variation conditions using Newman's FAST-2 model. Residual stresses caused by overloads, crack opening loads, and growth retardation periods were compared.

  13. Renal Distribution Volumes of Indocyanine Green, [51Cr]EDTA, and 24Na in Man during Acute Renal Failure after Shock. IMPLICATIONS FOR THE PATHOGENESIS OF ANURIA

    PubMed Central

    Reubi, F. C.; Vorburger, C.; Tuckman, J.

    1973-01-01

    The mechanism responsible for the anuria in acute renal failure after shock is still controversial. Suppressed glomerular filtration and/or tubular back-diffusion of the filtrate are major possible causes. In the present investigation, seven patients with acute anuria, three of these seven again in the polyuric phase, six patients with moderate renal impairment, four patients with chronic renal failure, and eight subjects with normal renal function were studied by a multiple indicator-dilution method in which the total renal blood flow and renal distribution volumes of indocyanine green, [51Cr]EDTA, and 24Na were determined. In normal subjects the average values for one kidney were 582 ml/min, 42 ml, 92 ml, and 139 ml, respectively. The measurements in the patients with moderate renal impairment were similar to those in the normal subjects, but were decreased in chronic renal failure. In acute anuria, the average values were 269 ml/min, 40 ml, 101 ml, and 114 ml and the kidney volume, estimated radiographically, was increased by 40%. When expressed as milliliters per milliliters kidney, the average distribution volume of 24Na was decreased from 0.64 to 0.38. This decrease is consistent with the hypothesis that suppressed filtration is largely responsible for the anuria and that back-diffusion is, at most, a contributory factor. The apparent contradiction between the relatively well-preserved total blood flow and the suppressed filtration may be due to a combination of afferent vasoconstriction and efferent vasodilatation. This view is supported by the observation that low filtration fractions were found in clearance measurements performed during the polyuric phase. PMID:4630601

  14. Experimental detection of iron overload in liver through neutron stimulated emission spectroscopy.

    PubMed

    Kapadia, A J; Tourassi, G D; Sharma, A C; Crowell, A S; Kiser, M R; Howell, C R

    2008-05-21

    Iron overload disorders have been the focus of several quantification studies involving non-invasive imaging modalities. Neutron spectroscopic techniques have demonstrated great potential in detecting iron concentrations within biological tissue. We are developing a neutron spectroscopic technique called neutron stimulated emission computed tomography (NSECT), which has the potential to diagnose iron overload in the liver at clinically acceptable patient dose levels through a non-invasive scan. The technique uses inelastic scatter interactions between atomic nuclei in the sample and incoming fast neutrons to non-invasively determine the concentration of elements in the sample. This paper discusses a non-tomographic application of NSECT investigating the feasibility of detecting elevated iron concentrations in the liver. A model of iron overload in the human body was created using bovine liver tissue housed inside a human torso phantom and was scanned with a 5 MeV pulsed beam using single-position spectroscopy. Spectra were reconstructed and analyzed with algorithms designed specifically for NSECT. Results from spectroscopic quantification indicate that NSECT can currently detect liver iron concentrations of 6 mg g(-1) or higher and has the potential to detect lower concentrations by optimizing the acquisition geometry to scan a larger volume of tissue. The experiment described in this paper has two important outcomes: (i) it demonstrates that NSECT has the potential to detect clinically relevant concentrations of iron in the human body through a non-invasive scan and (ii) it provides a comparative standard to guide the design of iron overload phantoms for future NSECT liver iron quantification studies. PMID:18443387

  15. Promoting PGC-1α-driven mitochondrial biogenesis is detrimental in pressure-overloaded mouse hearts

    PubMed Central

    Karamanlidis, Georgios; Garcia-Menendez, Lorena; Kolwicz, Stephen C.; Lee, Chi Fung

    2014-01-01

    Mitochondrial dysfunction in animal models of heart failure is associated with downregulation of the peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α pathway. To test whether PGC-1α is an appropriate therapeutic target for increasing mitochondrial biogenesis and improving function in heart failure, we used a transgenic (TG) mouse model of moderate overexpression of PGC-1α (∼3-fold) in the heart. TG mice had small increases in citrate synthase activity and mitochondria size in the heart without alterations in myocardial energetics or cardiac function at baseline. In vivo dobutamine stress increased fractional shortening in wild-type mice, but this increase was attenuated in TG mice, whereas ex vivo isolated perfused TG hearts demonstrated normal functional and energetic response to high workload challenge. When subjected to pressure overload by transverse aortic constriction (TAC), TG mice displayed a significantly greater acute mortality for both male and female mice; however, long-term survival up to 8 wk was similar between the two groups. TG mice also showed a greater decrease in fractional shortening and a greater increase in left ventricular chamber dimension in response to TAC. Mitochondrial gene expression and citrate synthase activity were mildly increased in TG mice compared with wild-type mice, and this difference was also maintained after TAC. Our data suggest that a moderate level of PGC-1α overexpression in the heart compromises acute survival and does not improve cardiac function during chronic pressure overload in mice. PMID:25172896

  16. Fluid overload, pulse wave velocity, and ratio of brachial pre-ejection period to ejection time in diabetic and non-diabetic chronic kidney disease.

    PubMed

    Tsai, Yi-Chun; Chiu, Yi-Wen; Kuo, Hung-Tien; Chen, Szu-Chia; Hwang, Shang-Jyh; Chen, Tzu-Hui; Kuo, Mei-Chuan; Chen, Hung-Chun

    2014-01-01

    Fluid overload is one of the characteristics in chronic kidney disease (CKD). Changes in extracellular fluid volume are associated with progression of diabetic nephropathy. Not only diabetes but also fluid overload is associated with cardiovascular risk factors The aim of the study was to assess the interaction between fluid overload, diabetes, and cardiovascular risk factors, including arterial stiffness and left ventricular function in 480 patients with stages 4-5 CKD. Fluid status was determined by bioimpedance spectroscopy method, Body Composition Monitor. Brachial-ankle pulse wave velocity (baPWV), as a good parameter of arterial stiffness, and brachial pre-ejection period (bPEP)/brachial ejection time (bET), correlated with impaired left ventricular function were measured by ankle-brachial index (ABI)-form device. Of all patients, 207 (43.9%) were diabetic and 240 (50%) had fluid overload. For non-diabetic CKD, fluid overload was associated with being female (β = -2.87, P = 0.003), heart disease (β = 2.69, P = 0.04), high baPWV (β = 0.27, P = 0.04), low hemoglobin (β = -1.10, P < 0.001), and low serum albumin (β = -5.21, P < 0.001) in multivariate analysis. For diabetic CKD, fluid overload was associated with diuretics use (β = 3.69, P = 0.003), high mean arterial pressure (β = 0.14, P = 0.01), low bPEP/ET (β = -0.19, P = 0.03), low hemoglobin (β = -1.55, P = 0.001), and low serum albumin (β = -9.46, P < 0.001). In conclusion, baPWV is associated with fluid overload in non-diabetic CKD and bPEP/bET is associated with fluid overload in diabetic CKD. Early and accurate assessment of these associated cardiovascular risk factors may improve the effects of entire care in late CKD. PMID:25386836

  17. Iron overload due to mutations in ferroportin

    PubMed Central

    De Domenico, Ivana; Ward, Diane McVey; Musci, Giovanni; Kaplan, Jerry

    2013-01-01

    Iron overload disease due to mutations in ferroportin has a dominant inheritance and a variable clinical phenotype, such that some patients show early Küpffer cell iron loading and low transferrin saturation, while others show hepatocyte iron loading and high transferrin saturation. Studies expressing ferroportin mutant proteins in cultured cells have shown that mutant proteins fall into two main classes; proteins that do not localize to the cell surface and are unable to export iron, and those that localize to the cell surface but are unable to respond to the antimicrobial peptide hepcidin. Patients with mutant ferroportin proteins that do not localize to the cell surface show typical ferroportin disease with low transferrin saturation and early Küpffer cell iron loading, while patients with mutant proteins unable to respond to hepcidin show high transferrin saturation and early hepatocyte iron loading similar to classic hereditary hemochromatosis. The dominant genetic transmission of ferroportin-linked disorders is explained by the in vitro data, which suggest that ferroportin is a multimer and that the behavior of the mutant protein can affect the behavior of the wild type protein. PMID:16434376

  18. Obesity versus osteoarthritis: beyond the mechanical overload

    PubMed Central

    Sartori-Cintra, Angélica Rossi; Aikawa, Priscila; Cintra, Dennys Esper Correa

    2014-01-01

    Obesity is currently considered a major public health problem in the world, already reaching epidemic characteristics, according to the World Health Organization. Excess weight is the major risk factor associated with various diseases, such as type 2 diabetes mellitus, hypertension, dyslipidemia and osteometabolic diseases, including osteoporosis and osteoarthritis. Osteoarthritis is the most prevalent rheumatic disease and the leading cause of physical disability and reduced quality of life of the population over 65 years. It mainly involves the joints that bear weight - knees and hips. However, along with the cases of obesity, its prevalence is increasing, and even in other joints, such as hands. Thus, it is assumed that the influence of obesity on the development of OA is beyond mechanical overload. The purpose of this review was to correlate the possible mechanisms underlying the genesis and development of these two diseases. Increased fat mass is directly proportional to excessive consumption of saturated fatty acids, responsible for systemic low-grade inflammation condition and insulin and leptin resistance. At high levels, leptin assumes inflammatory characteristics and acts in the articular cartilage, triggering the inflammatory process and changing homeostasis this tissue with consequent degeneration. We conclude that obesity is a risk factor for osteoarthritis and that physical activity and changes in diet composition can reverse the inflammatory and leptin resistance, reducing progression or preventing the onset of osteoarthritis. PMID:25184806

  19. Signs of overload after an intensified training.

    PubMed

    Bresciani, G; Cuevas, M J; Molinero, O; Almar, M; Suay, F; Salvador, A; de Paz, J A; Marquez, S; González-Gallego, J

    2011-05-01

    This study investigated effects of a 9-week intensified aerobic training and 3-weeks of recovery on signs of overload in 9 healthy active young males. Blood and saliva samples were collected and psychological questionnaires were administered during baseline (T1), intermediate load (T2), maximal load (T3), and recovery (T4) periods. Maximal oxygen uptake increased and blood lactate concentration decreased in T3, while running time in a 3 000  m track field test was significantly shorter. No significant changes were found in hematocrit, haemoglobin concentration, white blood cell count, lactate dehydrogenase, transaminases, interleukin-6, tumour necrosis factor-α, myeloperoxidase and markers of oxidative stress in plasma, or salivary cortisol and testosterone. Increases in different negative affect scales and in the total mood disturbance score of the Profile of Mood States were observed during T3. Scores in the stress scales of the Recovery-Stress Questionnaire for Athletes and in the State Anxiety Scale of the State-Trait Anxiety Inventory also showed significant increases during T3. The lack of effects in biomarkers together with the changes observed in psychological assessment indicates that an intensified training can produce psychological disturbances prone to early overreaching development. Additionally, it seems that psychological parameters are sensitive markers to detect stress produced by load increases. PMID:21380974

  20. Differential Responses of Soleus and Plantaris Muscle Fibers to Overloading

    NASA Astrophysics Data System (ADS)

    Kawano, Fuminori; Shibaguchi, Tsubasa; Ohira, Takashi; Nakai, Naoya; Ohira, Yoshinobu

    2013-02-01

    Responses of slow and fast fibers in soleus and plantaris muscles of adult rats to overloading by the tendon transection of synergists were studied. Overloading-related hypertrophy was noted in the slow fibers of plantaris and soleus, although the magnitude was greater in plantaris. Five genes with minor expression in slow soleus muscle were identified by microarray analysis. Base-line expressions of these genes in slow fibers of plantaris were also low. Further, repressive effects of overloading on these genes were seen in some fast fibers of plantaris, not in whole plantaris and soleus. The data suggested that the repression of particular genes might be related to the pronounced morphological response of fibers expressing type II, including I+II, myosin heavy chain (MyHC), although these genes with lower base-line expression in slow fibers did not respond to overloading.

  1. [Hyperhydration and dialysis in acute kidney failure].

    PubMed

    Saner, Fuat H; Bienholz, Anja; Tyczynski, Bartosz; Kribben, Andreas; Feldkamp, Thorsten

    2015-05-01

    Despite the advances in critical care medicine, the hospital mortality in patients with acute kidney injury (AKI) requiring dialysis remains high. Depending on the underlying disease the in-house mortality is reported to be up to 80%. Several observational studies demonstrated an association between mortality and fluid overload. A primary mechanism of interest is that fluid overload causes tissue edema and subsequent reduction of perfusion, oxygenation and nutrient delivery. This results in further renal damage. In addition, fluid overload-related dilution within the extracellular space causes artificially low serum creatinine, which masks AKI diagnosis. As a consequence, renal protective management strategies are deferred, which further aggravates kidney injury. This aggravation of renal damage subsequently increases the mortality. This review discusses the role of fluid overload for outcomes in critically ill patients as described in the current literature and assesses criteria for the initiation of renal replacement therapy in this critically ill population. PMID:25970415

  2. Acute Response of Circulating Vascular Regulating MicroRNAs during and after High-Intensity and High-Volume Cycling in Children

    PubMed Central

    Kilian, Yvonne; Wehmeier, Udo F.; Wahl, Patrick; Mester, Joachim; Hilberg, Thomas; Sperlich, Billy

    2016-01-01

    Aim: The aim of the present study was to analyze the response of vascular circulating microRNAs (miRNAs; miR-16, miR-21, miR-126) and the VEGF mRNA following an acute bout of HIIT and HVT in children. Methods:Twelve healthy competitive young male cyclists (14.4 ± 0.8 years; 57.9 ± 9.4 ml·min−1·kg−1 peak oxygen uptake) performed one session of high intensity 4 × 4 min intervals (HIIT) at 90–95% peak power output (PPO), each interval separated by 3 min of active recovery, and one high volume session (HVT) consisting of a constant load exercise for 90 min at 60% PPO. Capillary blood from the earlobe was collected under resting conditions, during exercise (d1 = 20 min, d2 = 30 min, d3 = 60 min), and 0, 30, 60, 180 min after the exercise to determine miR-16, -21, -126, and VEGF mRNA. Results: HVT significantly increased miR-16 and miR-126 during and after the exercise compared to pre-values, whereas HIIT showed no significant influence on the miRNAs compared to pre-values. VEGF mRNA significantly increased during and after HIIT (d1, 30′, 60′, 180′) and HVT (d3, 0′, 60′). Conclusion: Results of the present investigation suggest a volume dependent exercise regulation of vascular regulating miRNAs (miR-16, miR-21, miR-126) in children. In line with previous data, our data show that acute exercise can alter circulating miRNAs profiles that might be used as novel biomarkers to monitor acute and chronic changes due to exercise in various tissues. PMID:27014090

  3. Contemporary management of acute right ventricular failure: a statement from the Heart Failure Association and the Working Group on Pulmonary Circulation and Right Ventricular Function of the European Society of Cardiology.

    PubMed

    Harjola, Veli-Pekka; Mebazaa, Alexandre; Čelutkienė, Jelena; Bettex, Dominique; Bueno, Hector; Chioncel, Ovidiu; Crespo-Leiro, Maria G; Falk, Volkmar; Filippatos, Gerasimos; Gibbs, Simon; Leite-Moreira, Adelino; Lassus, Johan; Masip, Josep; Mueller, Christian; Mullens, Wilfried; Naeije, Robert; Nordegraaf, Anton Vonk; Parissis, John; Riley, Jillian P; Ristic, Arsen; Rosano, Giuseppe; Rudiger, Alain; Ruschitzka, Frank; Seferovic, Petar; Sztrymf, Benjamin; Vieillard-Baron, Antoine; Yilmaz, Mehmet Birhan; Konstantinides, Stavros

    2016-03-01

    Acute right ventricular (RV) failure is a complex clinical syndrome that results from many causes. Research efforts have disproportionately focused on the failing left ventricle, but recently the need has been recognized to achieve a more comprehensive understanding of RV anatomy, physiology, and pathophysiology, and of management approaches. Right ventricular mechanics and function are altered in the setting of either pressure overload or volume overload. Failure may also result from a primary reduction of myocardial contractility owing to ischaemia, cardiomyopathy, or arrhythmia. Dysfunction leads to impaired RV filling and increased right atrial pressures. As dysfunction progresses to overt RV failure, the RV chamber becomes more spherical and tricuspid regurgitation is aggravated, a cascade leading to increasing venous congestion. Ventricular interdependence results in impaired left ventricular filling, a decrease in left ventricular stroke volume, and ultimately low cardiac output and cardiogenic shock. Identification and treatment of the underlying cause of RV failure, such as acute pulmonary embolism, acute respiratory distress syndrome, acute decompensation of chronic pulmonary hypertension, RV infarction, or arrhythmia, is the primary management strategy. Judicious fluid management, use of inotropes and vasopressors, assist devices, and a strategy focusing on RV protection for mechanical ventilation if required all play a role in the clinical care of these patients. Future research should aim to address the remaining areas of uncertainty which result from the complexity of RV haemodynamics and lack of conclusive evidence regarding RV-specific treatment approaches. PMID:26995592

  4. Multimedia reviews: multimedia overload produces "symplexity".

    PubMed

    Zingrone, Frank

    2003-03-01

    We humans "know" from information mediated through our "natural senses." All outside signals come to us through some medium-sound waves, pressure and touch, light waves, radio and television waves, and so forth. McLuhan's famous mantra "The medium is the message" paradoxically highlighted the critical transformation of meaning when each type of medium-radio, television, drums, hand signals-by its very nature modifies the message it is transmitting. In this month's column Dr. Zingrone brings challenging new ideas to the field of human communication and vividly describes the communication distortions that occur when the overload of increasingly complex modern media results in a paradoxical diminution of meaning itself. He has coined a term for this unintended consequence and given it to his exciting new book, The Media Symplex: At the Edge of Meaning in the Age of Chaos (1). Many of us may recognize the effect created by this accelerating phenomenon-our stupefaction as we experience the onslaught of sound and visual signals produced by a television news screen, where an avalanche of rapidly changing, overlapping, and distorted visual images flash at our eyes while screeching, undulating synthetic "music" crashes about our ears. And in that chaos we struggle to find meaning,Dr. Zingrone, who worked with McLuhan and who has written extensively about his work (2,3), has succeeded in his new book to move the pioneering work of human communication scientists forward and thereby help us all to understand the developing paradox and danger of more communication yet less meaning. PMID:12610237

  5. Mean platelet volume to platelet count ratio predicts in-hospital complications and long-term mortality in type A acute aortic dissection.

    PubMed

    Li, Dong-Ze; Chen, Qing-Jie; Sun, Hui-Ping; Zeng, Rui; Zeng, Zhi; Gao, Xiao-Ming; Ma, Yi-Tong; Yang, Yi-Ning

    2016-09-01

    Type A acute aortic dissection is a life-threatening vascular emergency because of its high morbidity and mortality. Platelet is a pivotal ingredient involved in the development of acute aortic dissection. In this study, we aimed to investigate whether mean platelet volume (MPV)/platelet count ratio predicts in-hospital complications and long-term mortality in type A acute aortic dissection. In this single-center and prospective cohort study, 106 consecutive patients with Stanford type A acute aortic dissection admitted to the hospital within 12 h after onset were recruited. The best cut-off value of MPV/platelet count ratio predicting all-cause mortality was determined by the receiver operator characteristic analysis. Patients were divided into high (H-MPV/platelet count) and low (L-MPV/platelet count) groups based on the cut-off value of 7.49 (10 fl/10/l). Patients were followed up for 3.5 years. Of the 106 acute aortic dissection patients, 71 (67.0%) died during the study period, with a median follow-up duration of 570 days. Compared to the L-MPV/platelet count group, patients with H-MPV/platelet count had a higher risk of in-hospital complications including hypotension, hypoxemia, myocardial ischemia/infarction, conscious disturbance, pericardial tamponade, paraplegia, and poor survival (all P < 0.05). In multivariable Cox regression models adjusted for potential confounders, MPV/platelet count ratio was positively associated with the hazard of all-cause mortality, irrespective of interventions either with medication only or urgent surgery, and the hazard ratios were 2.81 (95% confidence interval 1.28-4.48) for the H-MPV/platelet count group when taking L-MPV/platelet count group as the reference (P = 0.005). The MPV/platelet count ratio was a strong independent predictor for in-hospital complications and long-term mortality in patients with type A acute aortic dissection. PMID:26575495

  6. In Acute Stroke, Can CT Perfusion-Derived Cerebral Blood Volume Maps Substitute for Diffusion-Weighted Imaging in Identifying the Ischemic Core?

    PubMed Central

    Copen, William A.; Morais, Livia T.; Wu, Ona; Schwamm, Lee H.; Schaefer, Pamela W.; González, R. Gilberto; Yoo, Albert J.

    2015-01-01

    Background and Purpose In the treatment of patients with suspected acute ischemic stroke, increasing evidence suggests the importance of measuring the volume of the irreversibly injured “ischemic core.” The gold standard method for doing this in the clinical setting is diffusion-weighted magnetic resonance imaging (DWI), but many authors suggest that maps of regional cerebral blood volume (CBV) derived from computed tomography perfusion imaging (CTP) can substitute for DWI. We sought to determine whether DWI and CTP-derived CBV maps are equivalent in measuring core volume. Methods 58 patients with suspected stroke underwent CTP and DWI within 6 hours of symptom onset. We measured low-CBV lesion volumes using three methods: “objective absolute,” i.e. the volume of tissue with CBV below each of six published absolute thresholds (0.9–2.5 mL/100 g), “objective relative,” whose six thresholds (51%-60%) were fractions of mean contralateral CBV, and “subjective,” in which two radiologists (R1, R2) outlined lesions subjectively. We assessed the sensitivity and specificity of each method, threshold, and radiologist in detecting infarction, and the degree to which each over- or underestimated the DWI core volume. Additionally, in the subset of 32 patients for whom follow-up CT or MRI was available, we measured the proportion of CBV- or DWI-defined core lesions that exceeded the follow-up infarct volume, and the maximum amount by which this occurred. Results DWI was positive in 72% (42/58) of patients. CBV maps’ sensitivity/specificity in identifying DWI-positive patients were 100%/0% for both objective methods with all thresholds, 43%/94% for R1, and 83%/44% for R2. Mean core overestimation was 156–699 mL for objective absolute thresholds, and 127–200 mL for objective relative thresholds. For R1 and R2, respectively, mean±SD subjective overestimation were -11±26 mL and -11±23 mL, but subjective volumes differed from DWI volumes by up to 117 and 124

  7. Interleukin-6 and associated cytokine responses to an acute bout of high-intensity interval exercise: the effect of exercise intensity and volume.

    PubMed

    Cullen, Tom; Thomas, Andrew W; Webb, Richard; Hughes, Michael G

    2016-08-01

    Acute increases in interleukin (IL)-6 following prolonged exercise are associated with the induction of a transient anti-inflammatory state (e.g., increases in IL-10) that is partly responsible for the health benefits of regular exercise. The purposes of this study were to investigate the IL-6-related inflammatory response to high-intensity interval exercise (HIIE) and to determine the impact of exercise intensity and volume on this response. Ten participants (5 males and 5 females) completed 3 exercise bouts of contrasting intensity and volume (LOW, MOD, and HIGH). The HIGH protocol was based upon standard HIIE protocols, while the MOD and LOW protocols were designed to enable a comparison of exercise intensity and volume with a fixed duration. Inflammatory cytokine concentrations were measured in plasma (IL-6, IL-10) and also determined the level of gene expression (IL-6, IL-10, and IL-4R) in peripheral blood. The plasma IL-6 response to exercise (reported as fold changes) was significantly greater in HIGH (2.70 ± 1.51) than LOW (1.40 ± 0.32) (P = 0.04) and was also positively correlated to the mean exercise oxygen uptake (r = 0.54, P < 0.01). However, there was no change in anti-inflammatory IL-10 or IL-4R responses in plasma or at the level of gene expression. HIIE caused a significant increase in IL-6 and was greater than that seen in low-intensity exercise of the same duration. The increases in IL-6 were relatively small in magnitude, and appear to have been insufficient to induce the acute systemic anti-inflammatory effects, which are evident following longer duration exercise. PMID:27377137

  8. Characterizing the Epidemiology of Perioperative Transfusion-associated Circulatory Overload

    PubMed Central

    Clifford, Leanne; Jia, Qing; Yadav, Hemang; Subramanian, Arun; Wilson, Gregory A.; Murphy, Sean P.; Pathak, Jyotishman; Schroeder, Darrell R.; Ereth, Mark H.; Kor, Daryl J.

    2016-01-01

    Background Transfusion-associated circulatory overload (TACO) is a leading cause of transfusion-related fatalities, but its incidence and associated patient and transfusion characteristics are poorly understood. To inform surgical transfusion practice and to begin mitigating perioperative TACO, the authors aimed to define its epidemiology. Methods In this retrospective cohort study, the medical records of adult patients undergoing noncardiac surgery with general anesthesia during 2004 or 2011 and receiving intraoperative transfusions were screened using an electronic algorithm for identification of TACO. Those patients who were screened as high probability for TACO underwent rigorous manual review. Univariate and multivariate analyses evaluated associations between patient and transfusion characteristics with TACO rates in a before-and-after study design. Results A total of 2,162 and 1,908 patients met study criteria for 2004 and 2011, respectively. The incidence of TACO was 5.5% (119 of 2,162) in 2004 versus 3.0% (57 of 1,908) in 2011 (P < 0.001), with comparable rates for men (4.8% [98 of 2,023]) and women (3.8% [78 of 2,047]) (P = 0.09). Overall, vascular (12.1% [60 of 497]), transplant (8.8% [17 of 193]), and thoracic surgeries (7.2% [10 of 138]) carried the highest TACO rates. Obstetric and gynecologic patients had the lowest rate (1.4% [4 of 295]). The incidence of TACO increased with volume transfused, advancing age, and total intraoperative fluid balance (all P < 0.001). Conclusions The incidence of perioperative TACO is similar to previous estimates in nonsurgical populations. There was a reduction in TACO rate between 2004 and 2011, with incidence patterns remaining comparable in subgroup analyses. Future efforts exploring risk factors for TACO may guide preventive or therapeutic interventions, helping to further mitigate this transfusion complication. PMID:25611653

  9. Differential expression of stress-inducible proteins in chronic hepatic iron overload

    SciTech Connect

    Brown, Kyle E. Broadhurst, Kimberly A.; Mathahs, M. Meleah; Weydert, Jamie

    2007-09-01

    Introduction:: Oxidative stress can trigger a cellular stress response characterized by induction of antioxidants, acute phase reactants (APRs) and heat shock proteins (HSPs), which are presumed to play a role in limiting tissue damage. In rodents, hepatic iron overload causes oxidative stress that results in upregulation of antioxidant defenses with minimal progressive liver injury. The aim of this study was to determine whether iron overload modulates expression of other stress-responsive proteins such as APRs and HSPs that may confer protection against iron-induced damage in rodent liver. Methods:: Male rats received repeated injections of iron dextran or dextran alone over a 6-month period. Hepatic transcript levels for a panel of APRs and HSPs were quantitated by real-time PCR and protein expression was evaluated by Western blot and immunohistochemistry. Results:: Hepatic iron concentrations were increased > 50-fold in the iron-loaded rats compared to controls. Iron loading resulted in striking increases in mRNAs for Hsp32 (heme oxygenase-1; 12-fold increase vs. controls) and metallothionein-1 and -2 (both increased {approx} 6-fold). Transcripts for {alpha}1-acid glycoprotein, the major rat APR, were increased {approx} 3-fold, while expression of other classical APRs was unaltered. Surprisingly, although mRNA levels for the HSPs were not altered by iron, the abundance of Hsp25, Hsp70 and Hsp90 proteins was uniformly reduced in the iron-loaded livers, as were levels of NAD(P)H:quinone oxidoreductase 1, an Hsp70 client protein. Conclusions:: Chronic iron administration elicits a unique pattern of stress protein expression. These alterations may modulate hepatic responses to iron overload, as well as other injury processes.

  10. A Descriptive Study of the Temporal Patterns of Volume and Contents Change in Human Acute Burn Edema: Application in Evidence-Based Intervention and Research Design.

    PubMed

    Edgar, Dale W; Fear, Mark; Wood, Fiona M

    2016-01-01

    Edema after burn contributes significantly to burn wound depth conversion. In humans after burn injury, there is a lack of detailed understanding of the contents and temporal changes in volume of acute tissue edema. The novel findings of these studies relate to the collection of edema fluid after partial-thickness burn injury. Edema volume peaks on day 1 after burn without formal fluid resuscitation. The studies indicated that the peak was on day 2 for a resuscitated burn. In contrast, animal studies suggest that the peak of edema occurs by or before day 1 after injury. The findings confirm the pitfalls of evidence derived from animal models and assuming direct transference to humans. Postburn edema was demonstrated to be a high-protein fluid (ie, ≥10 g/L) for the duration of the inflammatory period. The presence of high-protein edema presents greater challenges to clinicians developing novel treatment options. The rate of volume change over time tapered to insignificant levels after day 4 following burn. Greater than 98% of the edema contents was fluid. However, the size of particulate matter did not preclude it passing through patent lymphatic collectors. The results indicate a necessity for urgent postburn intervention, which should incorporate the active stimulation of the lymphatic system to improve efficacy of edema removal. PMID:27322367

  11. Acute Modifications of Circulating Volume and Respiratory Maneuvers in the Cardiovascular Assessment of Long-Duration Crewmembers

    NASA Technical Reports Server (NTRS)

    Bogomolov, V. V.; Alferova, I. V.; Dulchavsky, S. A.; Garcia, K. M.; Martin, D. S.; Melton, S. L.; Sargsyan, A. E.; Hamilton, D. R.; Duncan, J. M.

    2010-01-01

    This U.S. - Russian project is aimed at improved assessment of cardiac and vascular parameters associated with circulating volume and its distribution in long-duration space flight. Objective responses to modified Valsalva and Mueller maneuvers were measured by cardiac and vascular ultrasound before, during, and after temporary volume redistribution by means of Braslet-M thigh occlusion cuffs (Russia). Braslet-M cuffs are custom fitted to each crewmember prior to launch on the Soyuz as a Russian countermeasure for space adaptation fluid shifts

  12. [Electrical aspects of experimental diastolic and mixed ventricular overload].

    PubMed

    de Micheli, A; Medrano, G A; Casanova, J M

    1990-01-01

    Hemodynamic and electrical adaptation of ventricular myocardium to progressive diastolic and combined overloads was studied in mongrel dogs weighing between 15 and 20 Kg, anesthetized with intraperitoneal sodium pentobarbital (35 mg/Kg). Unipolar epicardial and intracavitary records as well as corresponding ventricular pressure curves were obtained every 30 mn after infusion was begun. The systolic arterial pressure was followed continuously by a mercury manometer. Right ventricular overload was produced by means of continuous venous infusion of saline solution in a group of 115 dogs with open pericardium (Series A) and in another of 45 dogs with intact pericardium (Series B). In Series A, right proximal and peripheral blocks were present in all the cases, beginning at 180 mn of infusion. In Series B, at 210 mn blocks were not present in 18 dogs (40%), and right peripheral blocks were present in 27 (60%). Left ventricular overload was obtained through continuous infusion of saline serum into left atria of 31 dogs with open pericardium (Series A1) and of another 50 with intact pericardium (Series B1). Only peripheral left blocks appeared in both series. Between 240 and 300 mn of infusion, the percentage of surviving animals was greater in Series B1, with a statistically significant difference at 270 and 300 mn. The pericardium seems to hinder the adaptation of right ventricular myocardium to the overloads evaluated, while it seems to help the response of the left ventricular myocardium to diastolic and combined overload. PMID:2344221

  13. Fat overload syndrome after the rapid infusion of SMOFlipid emulsion.

    PubMed

    Hojsak, Iva; Kolaček, Sanja

    2014-01-01

    Fat overload syndrome is a well-known complication of intravenous lipid emulsion therapy. It is characterized by headaches, fever, jaundice, hepatosplenomegaly, respiratory distress, and spontaneous hemorrhage. Other symptoms include anemia, leukopenia, thrombocytopenia, low fibrinogen levels, and coagulopathy. Several reports in the literature describe fat overload syndrome caused by rapid infusion of lipid emulsions, all with soybean-based lipid emulsions. We report fat overload syndrome in a 2-year-old girl with short bowel syndrome on home parenteral nutrition. Fat overload syndrome occurred as a result of accidental, very rapid infusion of a 20% soy oil, medium-chain triglyceride, olive and fish oil-based lipid emulsion (SMOFlipid) that showed the same complications seen with an earlier lipid emulsion (Intralipid). The patient was successfully treated with supportive care combining fluid infusion, transfusion of platelets, and substitution of serum albumin (0.5 g/kg/d) and fresh-frozen plasma (10 mL/kg). In the next couple of days, she received extra platelets, erythrocyte transfusion, and filgrastim (Neupogen; 5 µg/kg/d) due to a very low leukocyte count. To the best of our knowledge, this is the first case of fat overload syndrome caused by SMOFlipid emulsion described in the literature. PMID:23520135

  14. The Dose-Volume Relationship of Small Bowel Irradiation and Acute Grade 3 Diarrhea During Chemoradiotherapy for Rectal Cancer

    SciTech Connect

    Robertson, John M. Lockman, David; Yan Di; Wallace, Michelle

    2008-02-01

    Purpose: Previous work has found a highly significant relationship between the irradiated small-bowel volume and development of Grade 3 small-bowel toxicity in patients with rectal cancer. This study tested the previously defined parameters in a much larger group of patients. Methods and Materials: A total of 96 consecutive patients receiving pelvic radiation therapy for rectal cancer had treatment planning computed tomographic scans with small-bowel contrast that allowed the small bowel to be outlined with calculation of a small-bowel dose-volume histogram for the initial intended pelvic treatment to 45 Gy. Patients with at least one parameter above the previously determined dose-volume parameters were considered high risk, whereas those with all parameters below these levels were low risk. The grade of diarrhea and presence of liquid stool was determined prospectively. Results: There was a highly significant association with small-bowel dose-volume and Grade 3 diarrhea (p {<=} 0.008). The high-risk and low-risk parameters were predictive with Grade 3 diarrhea in 16 of 51 high-risk patients and in 4 of 45 low-risk patients (p = 0.01). Patients who had undergone irradiation preoperatively had a lower incidence of Grade 3 diarrhea than those treated postoperatively (18% vs. 28%; p = 0.31); however, the predictive ability of the high-risk/low-risk parameters was better for preoperatively (p = 0.03) than for postoperatively treated patients (p = 0.15). Revised risk parameters were derived that improved the overall predictive ability (p = 0.004). Conclusions: The highly significant dose-volume relationship and validity of the high-risk and low-risk parameters were confirmed in a large group of patients. The risk parameters provided better modeling for the preoperative patients than for the postoperative patients.

  15. The effect of iron overload and chelation on erythroid differentiation.

    PubMed

    Taoka, Kazuki; Kumano, Keiki; Nakamura, Fumihiko; Hosoi, Masataka; Goyama, Susumu; Imai, Yoichi; Hangaishi, Akira; Kurokawa, Mineo

    2012-02-01

    We investigated the mechanisms of hematopoietic disorders caused by iron overload and chelation, in particular, the inhibition of erythroblast differentiation. Murine c-kit(+) progenitor cells or human CD34(+) peripheral blood hematopoietic progenitors were differentiated in vitro to the erythroid lineage with free iron and/or an iron chelator. Under iron overload, formation of erythroid burst-forming unit colonies and differentiation to mature erythroblasts were significantly suppressed; these effects were canceled by iron chelation with deferoxamine (DFO). Moreover, excessive iron burden promoted apoptosis in immature erythroblasts by elevating intracellular reactive oxygen species (ROS). Interestingly, both DFO and a potent anti-oxidant agent reduced intracellular ROS levels and suppressed apoptosis, thus restoring differentiation to mature erythroblasts. Accordingly, intracellular ROS may represent a new therapeutic target in the treatment of iron overload. PMID:22193844

  16. Salvaging transient data with overloads and zero offsets

    SciTech Connect

    Smallwood, D.O.; Cap, J.S.

    1997-10-21

    The authors are sometimes presented with data with serious flaws, like overloads, zero shifts, and impulse noise, including much of the available pyrotechnic data. Obviously, these data should not be used if at all possible. However, they are sometimes forced to use these data as the only data available. Methods to salvage these data are discussed. Using the methods requires judgment, and the results must be accepted with the understanding that the answers are credible, not necessarily correct. None of the methods will recover information lost due to overloads or non-linearities of the data system. The best that can be accomplished is the recovery of data, after the data system has recovered from the overload. Several correction methods are discussed: high pass filtering of the data, correction with two forms of an exponential function, and a correction with the form t exp({minus}{alpha}t). Examples showing the results of the methods will be given using flawed pyrotechnic data.

  17. Intradialytic hypertension during chronic haemodialysis and subclinical fluid overload assessed by bioimpedance spectroscopy

    PubMed Central

    Sebastian, Sajith; Filmalter, Christelle; Harvey, Justin; Chothia, Mogamat-Yazied

    2016-01-01

    Background Intradialytic hypertension (IDH) increases morbidity and mortality. The prevalence in South Africa is unknown. The pathogenesis is unclear, but it has been suggested that IDH may be due to subclinical fluid overload. The objective of this study was to determine the prevalence of IDH and to evaluate its association with fluid overload using bioimpedance spectroscopy (BIS). Methods A cross-sectional study involving 190 chronic haemodialysis patients in the Western Cape province of South Africa was conducted between January 2013 and May 2014. IDH was defined as a >10 mmHg increase in systolic blood pressure in at least four of six prior consecutive haemodialysis sessions. Results The prevalence of IDH was 28.4% (n = 54). There was a trend towards pre-dialysis overhydration in the IDH group when compared with controls {2.6 L [95% confidence interval (CI) 1.7–3.4] versus 1.8 L [95% CI 1.4–2.1], respectively; P = 0.06} as measured by BIS, but no difference in mean ultrafiltration (UF) volume (2.4 versus 2.6 L; P = 0.30). A trend towards greater use of antihypertensive drugs was noted in the IDH group [2.5 drugs (95% CI 2.15–2.87) versus 2.1 (95% CI 1.82–2.30); P = 0.05]. More participants in the IDH group received calcium channel blockers (54 versus 36; P = 0.03). Conclusions The prevalence of IDH in our treatment centres is much higher than previously reported. Subclinical fluid overload may be a major contributing factor to the mechanism of this condition. The use of BIS identifies patients who may benefit from additional UF. PMID:27478611

  18. Effects of experimental cardiac volume loading on left atrial phasic function in healthy dogs.

    PubMed

    Osuga, Tatsuyuki; Nakamura, Kensuke; Morita, Tomoya; Nisa, Khoirun; Yokoyama, Nozomu; Sasaki, Noboru; Morishita, Keitaro; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

    2016-09-01

    OBJECTIVE To elucidate the relationship between acute volume overload and left atrial phasic function in healthy dogs. ANIMALS 6 healthy Beagles. PROCEDURES Dogs were anesthetized. A Swan-Ganz catheter was placed to measure mean pulmonary capillary wedge pressure (PCWP). Cardiac preload was increased by IV infusion with lactated Ringer solution at 150 mL/kg/h for 90 minutes. Transthoracic echocardiography was performed before (baseline) and at 15, 30, 45, 60, 75, and 90 minutes after volume loading began. At each echocardiographic assessment point, apical 4-chamber images were recorded and analyzed to derive time-left atrial area curves. Left atrial total (for reservoir function), passive (for conduit function), and active (for booster-pump function) fractional area changes were calculated from the curves. RESULTS Volume overload resulted in a significant increase from baseline in PCWP from 15 to 90 minutes after volume loading began. All fractional area changes at 15 to 90 minutes were significantly increased from baseline. In multiple regression analysis, quadratic regression models were better fitted to the relationships between PCWP and each of the total and active fractional area changes than were linear regression models. A linear regression model was better fitted to the relationship between PCWP and passive fractional area change. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that left atrial phasic function assessed on the basis of left atrial phasic areas was enhanced during experimental cardiac volume loading in healthy dogs. The effect of volume load should be considered when evaluating left atrial phasic function by indices derived from left atrial phasic sizes. PMID:27580106

  19. Effects of load-volume on EPOC after acute bouts of resistance training in resistance-trained men.

    PubMed

    Abboud, George J; Greer, Beau K; Campbell, Sara C; Panton, Lynn B

    2013-07-01

    Recent investigations have shown excess postexercise oxygen consumption (EPOC) to be elevated for up to 48 hours in both untrained and trained subjects after resistance training (RT). The purpose of this study was to investigate the effect of load-volume on EPOC. Eight trained men (aged 22 ± 3 years) participated in 2 randomized RT bouts separated by at least 1 week with total load-volumes of 10,000 and 20,000 kg, respectively. Intensity of RT (85% 1 repetition maximum) did not differ between trials. Exercise energy expenditure and resting metabolic rate (RMR) were measured by indirect calorimetry at 8.5 hours before, 1.5 hours before, and during RT bouts and 12, 24, 36, and 48 hours after exercise. Creatine kinase (CK) was measured before and after RT, and 12, 24, 36, and 48 hours postexercise; ratings of perceived muscle soreness were measured on a similar time course save the immediate postexercise time point. Analysis of variance with repeated measures was used to analyze dependent variables. During the 20,000 kg trial, subjects expended significantly (p < 0.01) more energy (484 ± 29 kcal) than the 10,000 kg lift (247 ± 18 kcal). After the 20,000 kg lift, 12 hours postexercise, CK (1,159 ± 729 U·L) was significantly elevated (p < 0.05) as compared with baseline (272 ± 280 U·L) and immediately postexercise (490 ± 402 U·L). No significant time or trial differences were found in RMR between the 10,000 and 20,000 kg trials. In conclusion, high-intensity RT with load-volumes of up to 20,000 kg using resistance-trained men does not significantly increase EPOC above baseline RMR. PMID:23085971

  20. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

    PubMed Central

    Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

    2016-01-01

    Background COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. Objective We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Patients and methods Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation – volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2–4 hours and 48 hours. Results Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2–4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both); after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05). Vital signs during 2–4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2–4 hours and 48 hours was significantly lower than that in the control group (P<0.05), while other variables were not significantly different between groups (P>0.05). Conclusion Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining

  1. Fluid overload is associated with an increased risk for 90-day mortality in critically ill patients with renal replacement therapy: data from the prospective FINNAKI study

    PubMed Central

    2012-01-01

    Introduction Positive fluid balance has been associated with an increased risk for mortality in critically ill patients with acute kidney injury with or without renal replacement therapy (RRT). Data on fluid accumulation prior to RRT initiation and mortality are limited. We aimed to study the association between fluid accumulation at RRT initiation and 90-day mortality. Methods We conducted a prospective, multicenter, observational cohort study in 17 Finnish intensive care units (ICUs) during a five-month period. We collected data on patient characteristics, RRT timing, and parameters at RRT initiation. We studied the association of parameters at RRT initiation, including fluid overload (defined as cumulative fluid accumulation > 10% of baseline weight) with 90-day mortality. Results We included 296 RRT-treated critically ill patients. Of 283 patients with complete data on fluid balance, 76 (26.9%) patients had fluid overload. The median (interquartile range) time from ICU admission to RRT initiation was 14 (3.3 to 41.5) hours. The 90-day mortality rate of the whole cohort was 116 of 296 (39.2%; 95% confidence interval 38.6 to 39.8%). The crude 90-day mortality of patients with or without fluid overload was 45 of 76 (59.2%) vs. 65 of 207 (31.4%), P < 0.001. In logistic regression, fluid overload was associated with an increased risk for 90-day mortality (odds ratio 2.6) after adjusting for disease severity, time of RRT initiation, initial RRT modality, and sepsis. Of the 168 survivors with data on RRT use at 90 days, 34 (18.9%, 95% CI 13.2 to 24.6%) were still dependent on RRT. Conclusions Patients with fluid overload at RRT initiation had twice as high crude 90-day mortality compared to those without. Fluid overload was associated with increased risk for 90-day mortality even after adjustments. PMID:23075459

  2. Cerebral Blood Volume ASPECTS Is the Best Predictor of Clinical Outcome in Acute Ischemic Stroke: A Retrospective, Combined Semi-Quantitative and Quantitative Assessment

    PubMed Central

    Padroni, Marina; Bernardoni, Andrea; Tamborino, Carmine; Roversi, Gloria; Borrelli, Massimo; Saletti, Andrea; De Vito, Alessandro; Azzini, Cristiano; Borgatti, Luca; Marcello, Onofrio; d’Esterre, Christopher; Ceruti, Stefano; Casetta, Ilaria; Lee, Ting-Yim; Fainardi, Enrico

    2016-01-01

    Introduction The capability of CT perfusion (CTP) Alberta Stroke Program Early CT Score (ASPECTS) to predict outcome and identify ischemia severity in acute ischemic stroke (AIS) patients is still questioned. Methods 62 patients with AIS were imaged within 8 hours of symptom onset by non-contrast CT, CT angiography and CTP scans at admission and 24 hours. CTP ASPECTS was calculated on the affected hemisphere using cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps by subtracting 1 point for any abnormalities visually detected or measured within multiple cortical circular regions of interest according to previously established thresholds. MTT-CBV ASPECTS was considered as CTP ASPECTS mismatch. Hemorrhagic transformation (HT), recanalization status and reperfusion grade at 24 hours, final infarct volume at 7 days and modified Rankin scale (mRS) at 3 months after onset were recorded. Results Semi-quantitative and quantitative CTP ASPECTS were highly correlated (p<0.00001). CBF, CBV and MTT ASPECTS were higher in patients with no HT and mRS≤2 and inversely associated with final infarct volume and mRS (p values: from p<0.05 to p<0.00001). CTP ASPECTS mismatch was slightly associated with radiological and clinical outcomes (p values: from p<0.05 to p<0.02) only if evaluated quantitatively. A CBV ASPECTS of 9 was the optimal semi-quantitative value for predicting outcome. Conclusions Our findings suggest that visual inspection of CTP ASPECTS recognizes infarct and ischemic absolute values. Semi-quantitative CBV ASPECTS, but not CTP ASPECTS mismatch, represents a strong prognostic indicator, implying that core extent is the main determinant of outcome, irrespective of penumbra size. PMID:26824672

  3. sup 1 H NMR study of renal trimethylamine responses to dehydration and acute volume loading in man

    SciTech Connect

    Avison, M.J.; Rothman, D.L.; Nixon, T.W.; Long, W.S.; Siegel, N.J. )

    1991-07-15

    The authors have used volume-localized {sup 1}H NMR spectroscopy to detect and measure changes in medullary trimethylamines (TMAs) in the human kidney in vivo. Localized water-suppressed {sup 1}H spectra were collected from a volume of interest located within the renal medulla by using a stimulated echo-based localization scheme. The principal resonances in the medullary {sup 1}H spectrum were residual water, lipid, and TMAs. The TMA line width was 7-15 Hz before filtering, and the signal-to-noise ratio was 40:1. In four normal volunteers, 15 hr of dehydration led to a significant increase in urine ismolality and decrease in body weight and an increase in medullary TMAs. A subsequent water load caused a transient water diuresis, a return to euvolemic body weight, and a significant reduction in medullary TMAs within 4 hr. These results suggest that TMAs may play an osmoregulatory role in the medulla of the normal human kidney.

  4. Digestive cells from Mytilus galloprovincialis show a partial regulatory volume decrease following acute hypotonic stress through mechanisms involving inorganic ions.

    PubMed

    Torre, Agata; Trischitta, Francesca; Corsaro, Carmelo; Mallamace, Domenico; Faggio, Caterina

    2013-08-01

    The response of isolated digestive cells of the digestive gland of Mytilus galloprovincialis to hypotonic shock was studied using videometric methods. The isolated cells exposed to a rapid change (from 1100 to 800 mosmol kg(-1) ) of the bathing solution osmolality swelled but thereafter underwent a regulatory volume decrease (RVD), tending to recover the original size. When the hypotonic stress was applied in the presence of quinine and glibenclamide, known inhibitors of swelling activated ion channels, the cells did not exhibit an RVD response; in addition, they showed a larger increase in size in respect to control cells. These observations suggest that the digestive cells of the digestive gland have the machinery to cope with the hyposmotic shock allowing them to exhibit a small but significant RVD preventing an excessive increase in cell size. The pharmacological treatment of digestive cells during the RVD experiments suggests that cell volume is regulated by K(+) and Cl(-) efflux followed by an obliged water efflux from the cell. The involvement of organic osmolytes such as taurine and betaine seems to be excluded by NMR measurement on digestive cells. PMID:23112133

  5. Information Overload and Viral Marketing: Countermeasures and Strategies

    NASA Astrophysics Data System (ADS)

    Cheng, Jiesi; Sun, Aaron; Zeng, Daniel

    Studying information diffusion through social networks has become an active research topic with important implications in viral marketing applications. One of the fundamental algorithmic problems related to viral marketing is the Influence Maximization (IM) problem: given an social network, which set of nodes should be considered by the viral marketer as the initial targets, in order to maximize the influence of the advertising message. In this work, we study the IM problem in an information-overloaded online social network. Information overload occurs when individuals receive more information than they can process, which can cause negative impacts on the overall marketing effectiveness. Many practical countermeasures have been proposed for alleviating the load of information on recipients. However, how these approaches can benefit viral marketers is not well understood. In our work, we have adapted the classic Information Cascade Model to incorporate information overload and study its countermeasures. Our results suggest that effective control of information overload has the potential to improve marketing effectiveness, but the targeting strategy should be re-designed in response to these countermeasures.

  6. 30 CFR 56.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Trailing cable overload protection. 56.12003 Section 56.12003 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  7. 30 CFR 56.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Trailing cable overload protection. 56.12003 Section 56.12003 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  8. 30 CFR 56.12001 - Circuit overload protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Circuit overload protection. 56.12001 Section 56.12001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  9. 30 CFR 56.12001 - Circuit overload protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit overload protection. 56.12001 Section 56.12001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  10. 30 CFR 56.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Trailing cable overload protection. 56.12003 Section 56.12003 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  11. 30 CFR 56.12001 - Circuit overload protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Circuit overload protection. 56.12001 Section 56.12001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  12. 30 CFR 56.12001 - Circuit overload protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Circuit overload protection. 56.12001 Section 56.12001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  13. 30 CFR 56.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Trailing cable overload protection. 56.12003 Section 56.12003 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  14. 30 CFR 56.12001 - Circuit overload protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Circuit overload protection. 56.12001 Section 56.12001 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  15. 30 CFR 56.12003 - Trailing cable overload protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Trailing cable overload protection. 56.12003 Section 56.12003 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES...

  16. Shift Work, Role Overload, and the Transition to Parenthood

    ERIC Educational Resources Information Center

    Perry-Jenkins, Maureen; Goldberg, Abbie E.; Pierce, Courtney P.; Sayer, Aline G.

    2007-01-01

    This article examines how the work hours, work schedules, and role overload of working-class couples are related to depressive symptoms and relationship conflict across the transition to parenthood. Data are from 132 dual-earner couples interviewed 5 times across the transition. Multilevel modeling analyses revealed that working evening or night…

  17. Functional hallux limitus and lesser-metatarsal overload.

    PubMed

    Clough, James G

    2005-01-01

    The implications of functional hallux limitus for lesser-metatarsal overload are discussed. A new method of treating functional hallux limitus is proposed, and three case histories are reviewed showing adequate resolution of symptoms using the proposed method of treatment. A proposed mechanism for the development of functional hallux limitus is discussed, and different methods of identification are illustrated. PMID:16291854

  18. Pressure Overload by Transverse Aortic Constriction Induces Maladaptive Hypertrophy in a Titin-Truncated Mouse Model.

    PubMed

    Zhou, Qifeng; Kesteven, Scott; Wu, Jianxin; Aidery, Parwez; Gawaz, Meinrad; Gramlich, Michael; Feneley, Michael P; Harvey, Richard P

    2015-01-01

    Mutations in the giant sarcomeric protein titin (TTN) are a major cause for inherited forms of dilated cardiomyopathy (DCM). We have previously developed a mouse model that imitates a TTN truncation mutation we found in a large pedigree with DCM. While heterozygous Ttn knock-in mice do not display signs of heart failure under sedentary conditions, they recapitulate the human phenotype when exposed to the pharmacological stressor angiotensin II or isoproterenol. In this study we investigated the effects of pressure overload by transverse aortic constriction (TAC) in heterozygous (Het) Ttn knock-in mice. Two weeks after TAC, Het mice developed marked impairment of left ventricular ejection fraction (p < 0.05), while wild-type (WT) TAC mice did not. Het mice also trended toward increased ventricular end diastolic pressure and volume compared to WT littermates. We found an increase in histologically diffuse cardiac fibrosis in Het compared to WT in TAC mice. This study shows that a pattern of DCM can be induced by TAC-mediated pressure overload in a TTN-truncated mouse model. This model enlarges our arsenal of cardiac disease models, adding a valuable tool to understand cardiac pathophysiological remodeling processes and to develop therapeutic approaches to combat heart failure. PMID:26504781

  19. Pressure Overload by Transverse Aortic Constriction Induces Maladaptive Hypertrophy in a Titin-Truncated Mouse Model

    PubMed Central

    Zhou, Qifeng; Kesteven, Scott; Wu, Jianxin; Aidery, Parwez; Gawaz, Meinrad; Gramlich, Michael; Feneley, Michael P.; Harvey, Richard P.

    2015-01-01

    Mutations in the giant sarcomeric protein titin (TTN) are a major cause for inherited forms of dilated cardiomyopathy (DCM). We have previously developed a mouse model that imitates a TTN truncation mutation we found in a large pedigree with DCM. While heterozygous Ttn knock-in mice do not display signs of heart failure under sedentary conditions, they recapitulate the human phenotype when exposed to the pharmacological stressor angiotensin II or isoproterenol. In this study we investigated the effects of pressure overload by transverse aortic constriction (TAC) in heterozygous (Het) Ttn knock-in mice. Two weeks after TAC, Het mice developed marked impairment of left ventricular ejection fraction (p < 0.05), while wild-type (WT) TAC mice did not. Het mice also trended toward increased ventricular end diastolic pressure and volume compared to WT littermates. We found an increase in histologically diffuse cardiac fibrosis in Het compared to WT in TAC mice. This study shows that a pattern of DCM can be induced by TAC-mediated pressure overload in a TTN-truncated mouse model. This model enlarges our arsenal of cardiac disease models, adding a valuable tool to understand cardiac pathophysiological remodeling processes and to develop therapeutic approaches to combat heart failure. PMID:26504781

  20. Human albumin solution for patients with cirrhosis and acute on chronic liver failure: Beyond simple volume expansion

    PubMed Central

    Valerio, Christopher; Theocharidou, Eleni; Davenport, Andrew; Agarwal, Banwari

    2016-01-01

    To provide an overview of the properties of human serum albumin (HSA), and to review the evidence for the use of human albumin solution (HAS) in critical illness, sepsis and cirrhosis. A MEDLINE search was performed using the terms “human albumin”, “critical illness”, “sepsis” and “cirrhosis”. The references of retrieved articles were reviewed manually. Studies published between 1980 and 2014 were selected based on quality criteria. Data extraction was performed by all authors. HSA is the main plasma protein contributing greatly to its oncotic pressure. HSA demonstrates important binding properties for endogenous and exogenous toxins, drugs and drug metabolites that account for its anti-oxidant and anti-inflammatory properties. In disease states, hypoalbuminaemia is secondary to decreased HSA production, increased loss or transcapillary leakage into the interstitial space. HSA function can be also altered in disease with reduced albumin binding capacity and increased production of modified isoforms. HAS has been used as volume expander in critical illness, but received criticism due to cost and concerns regarding safety. More recent studies confirmed the safety of HAS, but failed to show any survival benefit compared to the cheaper crystalloid fluids, therefore limiting its use. On the contrary, in cirrhosis there is robust data to support the efficacy of HAS for the prevention of circulatory dysfunction post-large volume paracentesis and in the context of spontaneous bacterial peritonitis, and for the treatment of hepato-renal syndrome and hypervolaemic hyponatraemia. It is likely that not only the oncotic properties of HAS are beneficial in cirrhosis, but also its functional properties, as HAS replaces the dysfunctional HSA. The role of HAS as the resuscitation fluid of choice in critically ill patients with cirrhosis, beyond the established indications for HAS use, should be addressed in future studies. PMID:26981172

  1. Human albumin solution for patients with cirrhosis and acute on chronic liver failure: Beyond simple volume expansion.

    PubMed

    Valerio, Christopher; Theocharidou, Eleni; Davenport, Andrew; Agarwal, Banwari

    2016-03-01

    To provide an overview of the properties of human serum albumin (HSA), and to review the evidence for the use of human albumin solution (HAS) in critical illness, sepsis and cirrhosis. A MEDLINE search was performed using the terms "human albumin", "critical illness", "sepsis" and "cirrhosis". The references of retrieved articles were reviewed manually. Studies published between 1980 and 2014 were selected based on quality criteria. Data extraction was performed by all authors. HSA is the main plasma protein contributing greatly to its oncotic pressure. HSA demonstrates important binding properties for endogenous and exogenous toxins, drugs and drug metabolites that account for its anti-oxidant and anti-inflammatory properties. In disease states, hypoalbuminaemia is secondary to decreased HSA production, increased loss or transcapillary leakage into the interstitial space. HSA function can be also altered in disease with reduced albumin binding capacity and increased production of modified isoforms. HAS has been used as volume expander in critical illness, but received criticism due to cost and concerns regarding safety. More recent studies confirmed the safety of HAS, but failed to show any survival benefit compared to the cheaper crystalloid fluids, therefore limiting its use. On the contrary, in cirrhosis there is robust data to support the efficacy of HAS for the prevention of circulatory dysfunction post-large volume paracentesis and in the context of spontaneous bacterial peritonitis, and for the treatment of hepato-renal syndrome and hypervolaemic hyponatraemia. It is likely that not only the oncotic properties of HAS are beneficial in cirrhosis, but also its functional properties, as HAS replaces the dysfunctional HSA. The role of HAS as the resuscitation fluid of choice in critically ill patients with cirrhosis, beyond the established indications for HAS use, should be addressed in future studies. PMID:26981172

  2. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload...

  3. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload...

  4. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric equipment and circuits; overload...

  5. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload...

  6. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload...

  7. Iron-overload injury and cardiomyopathy in acquired and genetic models is attenuated by resveratrol therapy

    PubMed Central

    Das, Subhash K.; Wang, Wang; Zhabyeyev, Pavel; Basu, Ratnadeep; McLean, Brent; Fan, Dong; Parajuli, Nirmal; DesAulniers, Jessica; Patel, Vaibhav B.; Hajjar, Roger J.; Dyck, Jason R. B.; Kassiri, Zamaneh; Oudit, Gavin Y.

    2015-01-01

    Iron-overload cardiomyopathy is a prevalent cause of heart failure on a world-wide basis and is a major cause of mortality and morbidity in patients with secondary iron-overload and genetic hemochromatosis. We investigated the therapeutic effects of resveratrol in acquired and genetic models of iron-overload cardiomyopathy. Murine iron-overload models showed cardiac iron-overload, increased oxidative stress, altered Ca2+ homeostasis and myocardial fibrosis resulting in heart disease. Iron-overload increased nuclear and acetylated levels of FOXO1 with corresponding inverse changes in SIRT1 levels in the heart corrected by resveratrol therapy. Resveratrol, reduced the pathological remodeling and improved cardiac function in murine models of acquired and genetic iron-overload at varying stages of iron-overload. Echocardiography and hemodynamic analysis revealed a complete normalization of iron-overload mediated diastolic and systolic dysfunction in response to resveratrol therapy. Myocardial SERCA2a levels were reduced in iron-overloaded hearts and resveratrol therapy restored SERCA2a levels and corrected altered Ca2+ homeostasis. Iron-mediated pro-oxidant and pro-fibrotic effects in human and murine cardiomyocytes and cardiofibroblasts were suppressed by resveratrol which correlated with reduction in iron-induced myocardial oxidative stress and myocardial fibrosis. Resveratrol represents a clinically and economically feasible therapeutic intervention to reduce the global burden from iron-overload cardiomyopathy at early and chronic stages of iron-overload. PMID:26638758

  8. Iron-overload injury and cardiomyopathy in acquired and genetic models is attenuated by resveratrol therapy.

    PubMed

    Das, Subhash K; Wang, Wang; Zhabyeyev, Pavel; Basu, Ratnadeep; McLean, Brent; Fan, Dong; Parajuli, Nirmal; DesAulniers, Jessica; Patel, Vaibhav B; Hajjar, Roger J; Dyck, Jason R B; Kassiri, Zamaneh; Oudit, Gavin Y

    2015-01-01

    Iron-overload cardiomyopathy is a prevalent cause of heart failure on a world-wide basis and is a major cause of mortality and morbidity in patients with secondary iron-overload and genetic hemochromatosis. We investigated the therapeutic effects of resveratrol in acquired and genetic models of iron-overload cardiomyopathy. Murine iron-overload models showed cardiac iron-overload, increased oxidative stress, altered Ca(2+) homeostasis and myocardial fibrosis resulting in heart disease. Iron-overload increased nuclear and acetylated levels of FOXO1 with corresponding inverse changes in SIRT1 levels in the heart corrected by resveratrol therapy. Resveratrol, reduced the pathological remodeling and improved cardiac function in murine models of acquired and genetic iron-overload at varying stages of iron-overload. Echocardiography and hemodynamic analysis revealed a complete normalization of iron-overload mediated diastolic and systolic dysfunction in response to resveratrol therapy. Myocardial SERCA2a levels were reduced in iron-overloaded hearts and resveratrol therapy restored SERCA2a levels and corrected altered Ca(2+) homeostasis. Iron-mediated pro-oxidant and pro-fibrotic effects in human and murine cardiomyocytes and cardiofibroblasts were suppressed by resveratrol which correlated with reduction in iron-induced myocardial oxidative stress and myocardial fibrosis. Resveratrol represents a clinically and economically feasible therapeutic intervention to reduce the global burden from iron-overload cardiomyopathy at early and chronic stages of iron-overload. PMID:26638758

  9. Cytoskeletal mechanics in pressure-overload cardiac hypertrophy

    NASA Technical Reports Server (NTRS)

    Tagawa, H.; Wang, N.; Narishige, T.; Ingber, D. E.; Zile, M. R.; Cooper, G. 4th

    1997-01-01

    We have shown that the cellular contractile dysfunction characteristic of pressure-overload cardiac hypertrophy results not from an abnormality intrinsic to the myofilament portion of the cardiocyte cytoskeleton but rather from an increased density of the microtubule component of the extramyofilament portion of the cardiocyte cytoskeleton. To determine how, in physical terms, this increased microtubule density mechanically overloads the contractile apparatus at the cellular level, we measured cytoskeletal stiffness and apparent viscosity in isolated cardiocytes via magnetic twisting cytometry, a technique by which magnetically induced force is applied directly to the cytoskeleton through integrin-coupled ferromagnetic beads coated with Arg-Gly-Asp (RGD) peptide. Measurements were made in two groups of cardiocytes from cats with right ventricular (RV) hypertrophy induced by pulmonary artery banding: (1) those from the pressure-overloaded RV and (2) those from the normally loaded same-animal control left ventricle (LV). Cytoskeletal stiffness increased almost twofold, from 8.53 +/- 0.77 dyne/cm2 in the normally loaded LV cardiocytes to 16.46 +/- 1.32 dyne/cm2 in the hypertrophied RV cardiocytes. Cytoskeletal apparent viscosity increased almost fourfold, from 20.97 +/- 1.92 poise in the normally loaded LV cardiocytes to 87.85 +/- 6.95 poise in the hypertrophied RV cardiocytes. In addition to these baseline data showing differing stiffness and, especially, apparent viscosity in the two groups of cardiocytes, microtubule depolymerization by colchicine was found to return both the stiffness and the apparent viscosity of the pressure overload-hypertrophied RV cells fully to normal. Conversely, microtubule hyperpolymerization by taxol increased the stiffness and apparent viscosity values of normally loaded LV cardiocytes to the abnormal values given above for pressure-hypertrophied RV cardiocytes. Thus, increased microtubule density constitutes primarily a viscous load on

  10. Different prescribed doses of high-volume peritoneal dialysis and outcome of patients with acute kidney injury.

    PubMed

    Ponce, Daniela; Brito, Germana Alves; Abrão, Juliana Gera; Balb, André Luis

    2011-01-01

    The optimal dialysis dose for the treatment of acute kidney injury (AKI) is controversial. No studies have directly examined the effects of peritoneal dialysis (PD) dose on outcomes in AKI. From January 2005 to January 2007, we randomly assigned critically ill patients with AKI to receive higher- or lower-intensity PD therapy (prescribed Kt/Vof 0.8 and 0.5 per session respectively). The main outcome measure was death within 30 days. Of the 61 enrolled patients, 30 were randomly assigned to higher-intensity therapy, and 31, to a lower-intensity PD dose. The two study groups had similar baseline characteristics and received treatment for 6.1 days and 5.7 days respectively (p = 0.42). At 30 days after randomization, 17 deaths had occurred in the higher-intensity group (55%), and 16 deaths, in the lower-intensity group (53%, p = 0.83). There was a significant difference between the groups in the PD dose prescribed compared with the dose delivered (higher-intensity group: 0.8 vs. 0.59, p = 0.04; lower-intensity group: 0.5 vs. 0.49, p = 0.89). The groups had similar metabolic control after 4 PD sessions (blood urea nitrogen: 69.3 +/- 14.4 mg/dL and 60.3 +/- 11.1 mg/dL respectively, p = 0. 71). In critically ill patients with AKI, an intensive PD dose did not lower the mortality or improve the recovery of kidney function or metabolic control. The PD dose is limited by dialysate flow and membrane permeability, and clearance per exchange can decrease if a shorter dwell time is applied. PMID:22073842

  11. How quickly can acute symptomatic hyponatremia be corrected?

    PubMed

    Yaprak, Mustafa; Turan, Mehmet Nuri; Tamer, Abdulkerim Furkan; Peker, Nuri; Demirci, Meltem Sezis; Çırpan, Teksin; Aşçı, Gülay

    2013-12-01

    The systemic absorption of the flush liquid, including sorbitol, glycine or mannitol, can lead to complications, such as hyponatremia, volume overload and pulmonary or cerebral edema. Acute hyponatremia is defined as a reduction in the plasma sodium level in less than 48 h. Acute symptomatic hyponatremia should be corrected aggressively because it may cause irreversible neurological damage and death. Rapid correction of hyponatremia causes severe neurologic deficits, such as central pontine myelinolysis; thus, the optimal therapeutic approach has been debated. This article examined acute symptomatic hyponatremia in a patient undergoing transcervical myomectomy for a submucosal myoma. A thirty-seven-year-old patient was evaluated in obstetrics and gynecology clinic because of altered mental status and agitation. There was no history of chronic illness or drug use. It was discovered that during the operation, 12 L of the flush fluid, which contained 5 % mannitol, had been infused, but only 7 L of the flush fluid had been collected. On physical examination, the patient's general condition was moderate, her cooperation was limited, she was agitated, and her blood pressure was 120/70 mmHg. The sodium level was 99 mEq/L. Furosemid and 3 % NaCl solution were given. Her serum sodium returned to normal by increasing 39 mEq/L within 14 h. Her recovery was uneventful, and she was discharged 24 h after her serum sodium returned to normal. In conclusion, if there is a difference between the infused and collected volumes of the mannitol irrigant, severe hyponatremia may develop due to the flush fluid used during transcervical hysteroscopy and myomectomy. In these patients, acute symptomatic hyponatremia may be corrected as rapidly as the sodium level dropped. PMID:23054312

  12. Clinical Evaluation of High-Volume Hemofiltration with Hemoperfusion Followed by Intermittent Hemodialysis in the Treatment of Acute Wasp Stings Complicated by Multiple Organ Dysfunction Syndrome.

    PubMed

    Si, Xiaoyun; Li, Jingjing; Bi, Xiaohong; Wu, Lan; Wu, Xiaoyan

    2015-01-01

    Multiple organ dysfunction syndrome (MODS) is a rare complication of wasp stings. Currently, there is no standardized treatment for MODS secondary to multiple wasp stings, although blood purification techniques are often used. This study aimed to analyze our experiences of using intermittent hemodialysis (IHD) with or without high-volume hemofiltration (HVHF) for treating acute wasp stings complicated by MODS. In this retrospective study, 36 patients with wasp stings complicated by MODS received either IHD combined with hemoperfusion, or HVHF (ultrafiltration flow rate, 70 mL/kg/h) combined with hemoperfusion for 5 days followed by IHD. Clinical symptoms, blood biochemical parameters, duration of mechanical ventilation, use of vasoactive agents, duration of hospital stay and survival rate were recorded, and Acute Physiology and Chronic Health Evaluation II (APACHE II) and multiple organ dysfunction (MOD) scores estimated. Patients treated with HVHF followed by IHD appeared to exhibit a faster recovery than those receiving IHD alone, as evidenced by superior improvements in MOD (4.29±1.08 vs. 2.27±1.07) and APACHE II (7.09±2.62 vs. 4.20±1.69) scores (P < 0.05). Patients treated with HVHF had significantly lower myoglobin, creatine kinase-MB, lactate dehydrogenase, bilirubin and creatinine levels than patients treated with IHD alone. In addition, the durations of hospital stay (13.15±2.77 vs. 27.92±3.18 days), vasopressor use (1.76±0.24 vs. 3.43 ± 1.01 days), mechanical ventilation (3.02±1.63 vs. 5.94 ± 2.11 days) and oliguria (6.57±2.45 vs. 15.29 ± 3.51 days) were reduced, and renal function more often recovered (85.1% vs. 53.1%), in the HVHF group compared with the IHD group (P < 0.05). These results raise the possibility that HVHF plus IHD may be superior to IHD alone for the treatment of acute wasp stings complicated by MODS; additional prospective studies are merited to explore this further. PMID:26207371

  13. Thermal Aging Characteristics of Insulation Paper in Mineral Oil under Overloaded Operating Transformers

    NASA Astrophysics Data System (ADS)

    Miyagi, Katsunori; Oe, Etsuo; Yamagata, Naoki; Miyahara, Hideyuki

    A sudden capacity increase in demand during the summer peak, or in contingencies such as malfunctioning transformers, may cause overload for normal transformers. In this paper, on the basis of examples of overloaded transformer operation in distributing substations, thermal aging testing in oil was carried out under various overload patterns, such as short time overload and long time overload, but with the winding insulation paper's life loss kept constant. From the results, various characteristics such as mean degree of polymerization and productions of furfural and (CO2+CO), and their effects on the life loss of the insulation paper were obtained.

  14. 99Tcm-pyrophosphate myocardial scintigraphy: the role of volume-rendered three-dimensional imaging in the diagnosis of acute myocardial infarction.

    PubMed

    Howarth, D M; Southee, A E; Allen, L W; Tan, P S

    1995-07-01

    The aim of this study was to evaluate the role of volume-rendered three-dimensional imaging in the diagnosis of acute myocardial infarction (AMI) using 99Tcm-pyrophosphate (99Tcm-PYP) scintigraphy in a diagnostically difficult group of patients. In total, 117 patients were studied using planar, single photon emission tomography (SPET) and 3-D volume-rendered imaging performed 3 h after receiving 555 MBq (15 mCi) of 99Tcm-PYP intravenously. 555MBq (15 mCi) of 99Tcm-PYP intravenously. Two teams of physicians reported in a blinded and random fashion on each planar, SPET and 3-D rotating image study. Individual reports were compared with reports that used all three imaging modalities in combination. Observer reproducibility was between 85 and 90% and inter-observer team agreement was between 87 and 91%. A score based on clinical history, electrocardiography, serum cardiac enzyme levels and cardiac risk factors was validated and used as a de facto 'gold standard' for AMI for 75 of the subjects for whom all these details were available. The sensitivity, specificity and overall accuracy of combined planar, SPET and 3-D rotating image modalities were all 84%. Analysis of each modality in isolation showed SPET imaging to have the highest sensitivity (74%) and specificity (89%). In combination with SPET and planar imaging, 3-D rotation image presentation increases diagnostic sensitivity without appreciably altering overall diagnostic accuracy. 99Tcm-PYP myocardial SPET imaging shows good utility in the diagnosis of AMI in diagnostically difficult patients. PMID:7478393

  15. Intermittent high-volume predilution on-line haemofiltration versus standard intermittent haemodialysis in critically ill patients with acute kidney injury: a prospective randomized study

    PubMed Central

    Škofic, Nataša; Arnol, Miha; Buturović-Ponikvar, Jadranka; Ponikvar, Rafael

    2012-01-01

    Background The optimal modality of dialysis treatment in critically ill patients with acute kidney injury (AKI) remains unclear. Intermittent high-volume predilution on-line haemofiltration (HF) is not a well-established dialysis modality. The purpose of the study was to compare clinical outcomes between HF and standard intermittent haemodialysis (HD) in this specific population. Methods In this prospective, randomized, controlled single-centre clinical study, we compared mortality and recovery of kidney function between HF and HD in critically ill adult patients with AKI. The primary study outcome was 60-day all-cause mortality. Secondary study outcomes included 30-day and in-hospital all-cause mortality along with recovery of kidney function. Time to kidney function recovery and the number of required dialysis procedures were analyzed in the subgroup of patients with in-hospital recovery of kidney function. Results Baseline characteristics of the 273 patients in the two study groups were similar. All-cause mortality by Day 60 was 65.0% in the HF group and 65.5% in the HD group (hazard ratio, 0.98; 95% confidence interval, 0.71–1.33; P = 0.87). There were also no significant differences between the two groups in 30-day and in-hospital all-cause mortality or recovery of kidney function. Time to kidney function recovery and the number of required dialysis procedures were similar between the HF and the HD subgroup of patients with in-hospital recovery of kidney function. Conclusions Dialysis treatment with intermittent high-volume predilution on-line HF in critically ill patients with AKI did not decrease mortality, improve recovery of kidney function or reduce the need for dialysis support compared to standard intermittent HD. PMID:22513706

  16. TIMP-2 mutant decreases MMP-2 activity and augments pressure overload induced LV dysfunction and heart failure.

    PubMed

    Givvimani, S; Kundu, S; Narayanan, N; Armaghan, F; Qipshidze, N; Pushpakumar, S; Vacek, T P; Tyagi, S C

    2013-05-01

    Pressure overload induces cardiac extracellular matrix (ECM) remodelling and results in heart failure. ECM remodelling by matrix metalloproteinases (MMPs) is primarily regulated by their target inhibitors, tissue inhibitor of matrix metalloproteinases (TIMPs). It is known that TIMP-2 is highly expressed in myocardium and is required for cell surface activation of pro-MMP-2. We and others have reported that imbalance between angiogenic growth factors and anti-angiogenic factors results in transition from compensatory cardiac hypertrophy to heart failure. We previously reported the pro-angiogenic role of MMP-2 in cardiac compensation, however, the specific role of TIMP-2 during pressure overload is yet unclear. We hypothesize that genetic ablation of TIMP-2 exacerbates the adverse cardiac matrix remodelling due to lack of pro-angiogenic MMP-2 and increase in anti-angiogenic factors during pressure overload stress and results in severe heart failure. To verify this, ascending aortic banding (AB) was created to mimic pressure overload, in wild type C57BL6/J and TIMP-2-/- (model of MMP-2 deficiency) mice. Left ventricular (LV) function assessed by echocardiography and pressure-volume loop studies showed severe LV dysfunction in TIMP-2-/- AB mice compared to controls. Expression of MMP-2, vascular endothelial growth factor (VEGF) was decreased and expression of MMP-9, anti-angiogenic factors endostatin and angiostatin was increased in TIMP-2-/- AB mice compared with wild type AB mice. Connexins (Cx) are the gap junction proteins that are widely present in the myocardium and play an important role in endothelial-myocyte coupling. Our results showed that expression of Cx 37 and 43 was decreased in TIMP-2-/- AB mice compared with corresponding wild type controls. These results suggest that genetic ablation of TIMP-2 decrease the expression of pro-angiogenic MMP-2, VEGF and increases anti-angiogenic factors that results in exacerbated abnormal ventricular remodelling leading

  17. Selecting ventilator settings according to variables derived from the quasi-static pressure/volume relationship in patients with acute lung injury.

    PubMed

    Putensen, C; Baum, M; Hörmann, C

    1993-09-01

    Knowledge of the pressure/volume (P/V) relationship of the lung may allow selection of tidal volume and positive end-expiratory pressure (PEEP) to optimize gas exchange without adversely affecting lung function or hemodynamics. Ten patients with acute lung injury were stabilized on controlled mechanical ventilation, based on conventional practice, using criteria from arterial blood gas data. The P/V relationship was determined under quasi-static conditions (end-expiratory and end-inspiratory, no flow periods > 0.8 s) during mechanical ventilation with an automated procedure that changed PEEP in a stepwise fashion. Differences in expiratory tidal volumes before and after a change in PEEP equaled the change in functional residual capacity (delta FRC). PEEP was set above the lowest point of the steepest section of the P/V curve (inflection pressure) to prevent end-expiratory lung collapse. Inspiratory tidal volumes (VTI) were adjusted to avoid an end-inspiratory lung volume reaching the flat part of the P/V curve. Averaged delta FRC versus PEEP curves were shifted to the left and the slope increased 1, 6, and 12 h after changing ventilator settings compared to baseline (P < 0.01). Averaged baseline delta FRC versus PEEP curves showed a marked inflection pressure that decreased after adjusting ventilator settings (P < 0.01). PEEP was increased from 7.4 +/- 1.8 cm H2O (baseline) to 11.9 +/- 1.6 cm H2O (1 h) (P < 0.001) according to measured baseline inflection pressures. Simultaneously, VTI had to be reduced from 759 +/- 161 mL (baseline) to 664 +/- 101 mL (1 h) (P < 0.01) to avoid end-inspiratory overinflation. To maintain minute volume constant ventilator frequency was increased from 14 +/- 1.2 (baseline) to 16 +/- 1.2 breaths/min (1 h) (P < 0.01). Maximum quasi-static compliance of 38 +/- 7 mL/cm H2O (baseline) increased to 46 +/- 9 mL/cm H2O (1 h) (P < 0.01). Maintaining FIO2 constant, PaO2 increased from a baseline of 90 +/- 16 mm Hg to 122 +/- 24 mm Hg (1 h) (P

  18. Validity of Acute Stroke Lesion Volume Estimation by Diffusion-Weighted Imaging–Alberta Stroke Program Early Computed Tomographic Score Depends on Lesion Location in 496 Patients With Middle Cerebral Artery Stroke

    PubMed Central

    Schröder, Julian; Cheng, Bastian; Ebinger, Martin; Köhrmann, Martin; Wu, Ona; Kang, Dong-Wha; Liebeskind, David S.; Tourdias, Thomas; Singer, Oliver C.; Christensen, Soren; Campbell, Bruce; Luby, Marie; Warach, Steven; Fiehler, Jens; Fiebach, Jochen B.; Gerloff, Christian; Thomalla, Götz

    2016-01-01

    Background and Purpose Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) has been used to estimate diffusion-weighted imaging (DWI) lesion volume in acute stroke. We aimed to assess correlations of DWI-ASPECTS with lesion volume in different middle cerebral artery (MCA) subregions and reproduce existing ASPECTS thresholds of a malignant profile defined by lesion volume ≥100 mL. Methods We analyzed data of patients with MCA stroke from a prospective observational study of DWI and fluid-attenuated inversion recovery in acute stroke. DWI-ASPECTS and lesion volume were calculated. The population was divided into subgroups based on lesion localization (superficial MCA territory, deep MCA territory, or both). Correlation of ASPECTS and infarct volume was calculated, and receiver-operating characteristics curve analysis was performed to identify the optimal ASPECTS threshold for ≥100-mL lesion volume. Results A total of 496 patients were included. There was a significant negative correlation between ASPECTS and DWI lesion volume (r=−0.78; P<0.0001). With regards to lesion localization, correlation was weaker in deep MCA region (r=−0.19; P=0.038) when compared with superficial (r=−0.72; P<0.001) or combined superficial and deep MCA lesions (r=−0.72; P<0.001). Receiver-operating characteristics analysis revealed ASPECTS≤6 as best cutoff to identify ≥100-mL DWI lesion volume; however, positive predictive value was low (0.35). Conclusions ASPECTS has limitations when lesion location is not considered. Identification of patients with malignant profile by DWI-ASPECTS may be unreliable. ASPECTS may be a useful tool for the evaluation of noncontrast computed tomography. However, if MRI is used, ASPECTS seems dispensable because lesion volume can easily be quantified on DWI maps. PMID:25316278

  19. Aceruloplasminaemia: a rare but important cause of iron overload.

    PubMed

    Doyle, Adam; Rusli, Ferry; Bhathal, Prithi

    2015-01-01

    We present a case of a 20-year-old man referred to our service with iron overload and mildly deranged liver biochemistry. Although liver histopathology was consistent with haemochromatosis, iron studies were not consistent with this diagnosis. Serum ceruloplasmin levels were undetectable, leading to a diagnosis of aceruloplasminaemia. Unlike other iron overload disorders, neurological complications are a unique feature of this illness, and often irreversible, once established. The patient was treated with iron chelation prior to the onset of neurological injury, and experienced progressive normalisation of his ferritin and liver biochemistry. This is one of the youngest diagnosed cases in the published literature and, crucially, was a rare case of diagnosis and treatment prior to the onset of neurological sequelae. This is presented alongside a review of previously published cases of aceruloplasminaemia, including responses to iron chelation therapy. PMID:25976187

  20. Epidemiology and diagnostic testing for hemochromatosis and iron overload.

    PubMed

    Adams, P C

    2015-05-01

    Hemochromatosis is the most common genetic disease in northern European populations. Body iron stores progressively increase in most patients, which can lead to cirrhosis of the liver, hepatocellular carcinoma, heart failure, arthritis, and pigmentation. Simple blood tests such as the serum ferritin and transferrin saturation are useful to suggest the diagnosis which can be confirmed in most cases with a simple genetic test for the C282Y mutation of the HFE gene. However, these blood tests are often misinterpreted and there are rare patients with iron overload without HFE mutations. A diagnostic approach is presented based on a large referral practice and a population-based study (HEIRS) which screened for iron overload in 101,168 participants. PMID:25976957

  1. Bending overload and implant fracture: a retrospective clinical analysis.

    PubMed

    Rangert, B; Krogh, P H; Langer, B; Van Roekel, N

    1995-01-01

    Thirty-nine patients with implant fractures treated by three of the authors have been analyzed as to probable causes. Thirty-five (90%) of the fractures occurred in the posterior region. Thirty (77%) of the prostheses were supported by one or two implants, which were exposed to a combination of cantilever load magnification and bruxism or heavy occlusal forces. It was concluded that prostheses supported by one or two implants and replacing missing posterior teeth are subjected to an increased risk of bending overload. The literature review indicates that the fracture frequency is low in these situations and this study demonstrates that with appropriate treatment planning, such overload situations can essentially be prevented. PMID:7615329

  2. Biliary copper excretion by hepatocyte lysosomes in the rat. Major excretory pathway in experimental copper overload

    SciTech Connect

    Gross, J.B. Jr.; Myers, B.M.; Kost, L.J.; Kuntz, S.M.; LaRusso, N.F.

    1989-01-01

    We investigated the hypothesis that lysosomes are the main source of biliary copper in conditions of hepatic copper overload. We used a rat model of oral copper loading and studied the relationship between the biliary output of copper and lysosomal hydrolases. Male Sprague-Dawley rats were given tap water with or without 0.125% copper acetate for up to 36 wk. Copper loading produced a 23-fold increase in the hepatic copper concentration and a 30-65% increase in hepatic lysosomal enzyme activity. Acid phosphatase histochemistry showed that copper-loaded livers contained an increased number of hepatocyte lysosomes; increased copper concentration of these organelles was confirmed directly by both x ray microanalysis and tissue fractionation. The copper-loaded rats showed a 16-fold increase in biliary copper output and a 50-300% increase in biliary lysosomal enzyme output. In the basal state, excretory profiles over time were similar for biliary outputs of lysosomal enzymes and copper in the copper-loaded animals but not in controls. After pharmacologic stimulation of lysosomal exocytosis, biliary outputs of copper and lysosomal hydrolases in the copper-loaded animals remained coupled: injection of colchicine or vinblastine produced an acute rise in the biliary output of both lysosomal enzymes and copper to 150-250% of baseline rates. After these same drugs, control animals showed only the expected increase in lysosomal enzyme output without a corresponding increase in copper output. We conclude that the hepatocyte responds to an increased copper load by sequestering excess copper in an increased number of lysosomes that then empty their contents directly into bile. The results provide direct evidence that exocytosis of lysosomal contents into biliary canaliculi is the major mechanism for biliary copper excretion in hepatic copper overload.

  3. Overload characteristics of paper-polypropylene-paper cable

    SciTech Connect

    Ernst, A. )

    1990-09-01

    The short-time rating of PPP pipe-type cable may be lower than the equivalent paper cable sized to carry the same normal load. The ratings depend on the relative conductor sizes and the maximum allowable conductor temperatures of the insulation. The insulation thermal resistivity may be a significant parameter for overload times of approximately one hour and should be verified for PPP insulation. The thermal capacitance temperature characteristic of PPP insulation is not known. However, the overload ratings are not very sensitive to this parameter. Overload ratings are given for maximum conductor temperatures from 105 C to 130 C. Use of ratings based on temperatures greater than 105 C would require testing to determine the extent of degradation of the insulation at these higher temperatures. PPP-insulated cable will be thermally stable over a wider range of operating conditions (voltage and current) compared with paper-insulated cable. The short-circuit ratings of PPP- and paper-insulated cable systems and the positive/negative and zero sequence impedances are compared. 21 refs., 22 figs., 5 tabs.

  4. Natural history and information overload: The case of Linnaeus

    PubMed Central

    Müller-Wille, Staffan; Charmantier, Isabelle

    2012-01-01

    Natural History can be seen as a discipline paradigmatically engaged in ‘data-driven research.’ Historians of early modern science have begun to emphasize its crucial role in the Scientific Revolution, and some observers of present day genomics see it as engaged in a return to natural history practices. A key concept that was developed to understand the dynamics of early modern natural history is that of ‘information overload.’ Taxonomic systems, rules of nomenclature, and technical terminologies were developed in botany and zoology to catch up with the ever increasing amount of information on hitherto unknown plant and animal species. In our contribution, we want to expand on this concept. After all, the same people who complain about information overload are usually the ones who contribute to it most significantly. In order to understand this complex relationship, we will turn to the annotation practices of the Swedish naturalist Carl Linnaeus (1707–1778). The very tools that Linnaeus developed to contain and reduce information overload, as we aim to demonstrate, facilitated a veritable information explosion that led to the emergence of a new research object in botany: the so-called ‘natural’ system. PMID:22326068

  5. Influence, information overload, and information technology in health care.

    PubMed

    Rebitzer, James B; Rege, Mari; Shepard, Christopher

    2008-01-01

    We investigate whether information technology (IT) can help physicians more efficiently acquire new knowledge in a clinical environment characterized by information overload. We combine analysis of data from a randomized trial with a theoretical model of the influence that IT has on the acquisition of new medical knowledge. Although the theoretical framework we develop is conventionally microeconomic, the model highlights the non-market and non-pecuniary influence activities that have been emphasized in the sociological literature on technology diffusion. We report three findings. First, empirical evidence and theoretical reasoning suggests that computer-based decision support will speed the diffusion of new medical knowledge when physicians are coping with information overload. Second, spillover effects will likely lead to "underinvestment" in this decision support technology. Third, alternative financing strategies common to new IT, such as the use of marketing dollars to pay for the decision support systems, may lead to undesirable outcomes if physician information overload is sufficiently severe and if there is significant ambiguity in how best to respond to the clinical issues identified by the computer. This is the first paper to analyze empirically and theoretically how computer-based decision support influences the acquisition of new knowledge by physicians. PMID:19548513

  6. RCAN1 Overexpression Exacerbates Calcium Overloading-Induced Neuronal Apoptosis

    PubMed Central

    Herculano, Bruno; Song, Weihong

    2014-01-01

    Down Syndrome (DS) patients develop characteristic Alzheimer's Disease (AD) neuropathology after their middle age. Prominent neuronal loss has been observed in the cortical regions of AD brains. However, the underlying mechanism leading to this neuronal loss in both DS and AD remains to be elucidated. Calcium overloading and oxidative stress have been implicated in AD pathogenesis. Two major isoforms of regulator of calcineurin 1 (RCAN1), RCAN1.1 and RCAN1.4, are detected in human brains. In this report we defined the transcriptional regulation of RCAN1.1 and RCAN1.4 by two alternative promoters. Calcium overloading upregulated RCAN1.4 expression by activating RCAN1.4 promoter through calcineurin-NFAT signaling pathway, thus forming a negative feedback loop in isoform 4 regulation. Furthermore, RCAN1.4 overexpression exacerbated calcium overloading-induced neuronal apoptosis, which was mediated by caspase-3 apoptotic pathway. Our results suggest that downregulating RCAN1.4 expression in neurons could be beneficial to AD patients. PMID:24751678

  7. Acute Kidney Injury: the beginning of the end of the dark ages

    PubMed Central

    Winterberg, Pamela D.; Lu, Christopher Y.

    2011-01-01

    There has been enormous progress in the understanding of acute kidney injury (AKI) over the last five years. This article reviews some of the salient new findings, the challenges revealed by these findings, and new insights into the pathogenesis of ischemic AKI. Clinical studies have demonstrated that even a small, transient rise in serum creatinine increases the risk of mortality in hospitalized patients and that a single event of AKI increases the risk for developing chronic kidney disease. Although the overall mortality rate from AKI has improved over the last two decades, it continues to be significant. Current treatment is focused on maintaining renal perfusion and avoiding volume overload. However, new therapeutic targets are emerging for the treatment of AKI as our understanding of the pathogenesis of ischemic injury and inflammation increases. Early diagnosis, however, continues to be challenging as the search continues for sensitive and specific biomarkers. PMID:21817881

  8. Continuous ultrafiltration in acute decompensated heart failure: current issues and future directions.

    PubMed

    Marenzi, Giancarlo; Morpurgo, Marco; Agostoni, Piergiuseppe

    2015-04-01

    Most patients hospitalized for acutely decompensated heart failure (ADHF) present with symptoms and signs of volume overload, which are also associated with high rates of death and re-hospitalization. Several studies have investigated the possible use of extracorporeal ultrafiltration in the management of ADHF, evaluating potential clinical benefits in terms of hospitalization and survival rates versus those of conventional diuretic therapy. Though ultrafiltration remains an extremely appealing therapeutic option for patients with AHDF, some of the most recent studies have reported conflicting results. Differences in the selection of study population, heterogeneity of the indications for the use of ultrafiltration, disparity in the ultrafiltration protocols, and high variability in the pharmacologic therapies used for the control group could explain some of these contradictory findings. The purpose of the present review is to provide an overview and an update on the mechanisms and clinical effects of ultrafiltration and on currently available evidence supporting its use in ADHF. PMID:25650293

  9. [Unexpected cause of acute renal failure in an 85-year-old woman].

    PubMed

    Fabbian, F; Stabellini, N; Catizone, L

    2008-01-01

    Acute postinfectious glomerulonephritis (APIGN) is usually diagnosed in young people, while in elderly people rapidly progressive forms appear to be the most important glomerular disease causing acute renal failure. We report on a 85-year-old woman with acute renal failure due to APIGN. An 85-year-old woman with a history of hypertension and cerebrovascular disease was hospitalized because of diarrhea and syncope associated with atrial fibrillation. She was found to have left lower lobe pneumonia. Serum creatinine was over 2 mg/dL. Fluids were given, without improvement in renal function but leading to volume overload instead. Within a few days serum creatinine reached a level of 5.4 mg/dL with reduction of urine output despite administration of diuretics. The patient developed hematuria and purpura of the feet. Serum IgA was high and the urine sediment showed casts. Methylprednisolone 125 mg i.v. was given for three days followed by prednisone 50 mg daily. The patient's clinical condition gradually improved and serum creatinine decreased to 1.9 mg/dL. Renal biopsy showed APIGN. During hospitalization, three major complications occurred: hemodynamic instability due to atrial fibrillation, Clostridium difficile colitis and urinary tract infections due to Enterococcus faecalis and Candida tropicans, all successfully treated. APIGN should be taken into account as a cause of acute renal failure in hospitalized elderly patients with many comorbidities. PMID:19048577

  10. Management of acute decompensated heart failure.

    PubMed

    Dec, G William

    2007-06-01

    Acute decompensated heart failure is the most common cause for hospitalization among patients over 65 years of age. It may result from new onset of ventricular dysfunction or, more typically, exacerbation of chronic heart failure symptoms. In-hospital mortality remains high for both systolic and diastolic forms of the disease. Therapy is largely empirical as few randomized, controlled trials have focused on this population and consensus practice guidelines are just beginning to be formulated. Treatment should be focused upon correction of volume overload, identifying potential precipitating causes, and optimizing vasodilator and beta-adrenergic blocker therapy. The majority of patients (>90%) will improve without the use of positive inotropic agents, which should be reserved for patients with refractory hypotension, cardiogenic shock, end-organ dysfunction, or failure to respond to conventional oral and/or intravenous diuretics and vasodilators. The role of aldosterone antagonists, biventricular pacing, and novel pharmacological agents including vasopressin antagonists, endothelin blockers, and calcium-sensitizing agents is also reviewed. PMID:17531903

  11. The perinatal thyroid in iodine deficient regions: risks of radioiodines--hazards of stable iodine overload. A study in the newborn rat.

    PubMed

    Hindié, E; Walker, F; Petiet, A; Bourahla, K; Galle, P; Colas-Linhart, N

    2001-05-01

    Administration of large quantities of stable iodine is an effective means of reducing the radiation burden on the thyroid in the event of a nuclear power-plant accident. Such administration may involve countries with low baseline dietary iodine intake. It is questioned whether stable iodine overload is safe, and in particular, what are its effects in newborn infants? Iodine-deficient newborn rats were submitted to a single acute administration of stable iodine (100 microg) on the second day of life. The effects on thyroid structure were studied, after 24 hr and after 7 days, using light microscopy. Compared to controls, the thyroids of animals submitted to stable iodine overload showed, 7 days after treatment, signs of acute toxicity including marked desquamation of epithelial cells and rupture of a large number of thyroid follicles. Our findings in iodine deficient newborn rats suggest that stable iodine overload may have side effects during perinatal life. This prophylactic measure should, therefore, be accompanied by follow-up of thyroid function. Thyroid hormones are critical for brain development, during the first period of life. PMID:11441946

  12. No fluid overload in male ultra-runners during a 100 km ultra-run.

    PubMed

    Knechtle, Beat; Senn, Oliver; Imoberdorf, Reinhard; Joleska, Irena; Wirth, Andrea; Knechtle, Patrizia; Rosemann, Thomas

    2011-01-01

    We investigated the change in body composition and hydration status in 27 male ultra-runners during a 100 km ultra-run. The athletes drank fluids ad libitum during the run; intake of calories, fluids, and electrolytes during performance were determined. Body mass decreased by 1.9 kg, haematocrit decreased, plasma [Na(+)] remained unchanged, and urinary specific gravity and plasma volume increased. Fluid intake was 0.52 (0.18) L/h and was related to running speed (r = 0.50; p = 0.0081). Δ body mass was associated with total fluid intake during the race (r = 0.49, p = 0.0095). Sodium intake amounted to 425 (478) mg/h and potassium intake to 140 (179) mg/h. Sodium and potassium intake were not related to either postrace concentration or change in plasma concentration. Sodium intake, however, was related to Δ urinary sodium concentration (r = 0.45, p = 0.0227). The increase in plasma volume was significantly and negatively related to both postrace plasma [Na(+)] (r = - 0.42, p = 0.0278) and the postrace potassium-to-sodium ratio in urine (r = - 0.44, p = 0.0218). To conclude, we found no fluid overload in these ultra-runners, the increase in plasma volume was most probably due to a stimulation of the renin-angiotensin-aldosterone system (RAAS) since sodium intake was not related to both the change in plasma [Na(+)] or postrace plasma [Na(+)]. PMID:21253973

  13. White Blood Cell Count to Mean Platelet Volume Ratio Is a Prognostic Factor in Patients with Non-ST Elevation Acute Coronary Syndrome with or without Metabolic Syndrome

    PubMed Central

    Dehghani, Mohammad Reza; Fakour, Sanam; Arjmand, Nasim

    2016-01-01

    Background and Objectives Leukocyte and platelet have been found to be associated with metabolic syndrome (MetS). We aimed to determine the usefulness of a novel marker named white blood cell count to mean platelet volume ratio (WMR) for predicting outcomes of non-ST elevation acute coronary syndrome (NSTE-ACS) with or without MetS. Subjects and Methods A total of 331 NSTE-ACS individuals (60±12.5 years, 57.4% male) were enrolled and followed for a median of 24 months. MetS was identified using the National Cholesterol Education Program Adult Treatment Panel III criteria. Results Patients were divided into two groups: high WMR (WMR≥720) and low WMR (WMR<720). Major adverse cardiovascular events (MACE) and MetS rates were significantly greater in the higher WMR group compared to those in the low WMR group (MACE: 14.3% vs. 25%, p=0.014; MetS: 50.9% vs. 75%, p<0.001). MetS was diagnosed in 62.2% of patients. MACE incidence in patients with or without MetS was comparable (p=0.737). Among MetS individuals, patients in the high WMR group had more MACE than the low WMR group (11.2% vs. 26.5%, p=0.007). However, MACE was comparable among non-MetS individuals (p=0.681). In multivariable Cox regression analysis, hazard ratios (HR) of MACE incidence for high-WMR in MetS individuals was 2.616 (95% confidence interval: 1.282–5.339, p=0.008). However, HR of MACE incidence for high WMR in non-MetS individuals was not significant. Conclusion Among NSTE-ACS patients without revascularization therapy, elevated admission WMR was associated with an increased risk of developing composite MACE in MetS individuals but not in non-MetS patients. PMID:27014354

  14. Effect of Extended CT Perfusion Acquisition Time on Ischemic Core and Penumbra Volume Estimation in Patients with Acute Ischemic Stroke due to a Large Vessel Occlusion

    PubMed Central

    Borst, Jordi; Marquering, Henk A.; Beenen, Ludo F. M.; Berkhemer, Olvert A.; Dankbaar, Jan Willem; Riordan, Alan J.; Majoie, Charles B. L. M.

    2015-01-01

    Background and Purpose It has been suggested that CT Perfusion acquisition times <60 seconds are too short to capture the complete in and out-wash of contrast in the tissue, resulting in incomplete time attenuation curves. Yet, these short acquisitions times are not uncommon in clinical practice. The purpose of this study was to investigate the occurrence of time attenuation curve truncation in 48 seconds CT Perfusion acquisition and to quantify its effect on ischemic core and penumbra estimation in patients with acute ischemic stroke due to a proximal intracranial arterial occlusion of the anterior circulation. Materials and Methods We analyzed CT Perfusion data with 48 seconds and extended acquisition times, assuring full time attenuation curves, of 36 patients. Time attenuation curves were classified as complete or truncated. Ischemic core and penumbra volumes resulting from both data sets were compared by median paired differences and interquartile ranges. Controlled experiments were performed using a digital CT Perfusion phantom to investigate the effect of time attenuation curve truncation on ischemic core and penumbra estimation. Results In 48 seconds acquisition data, truncation was observed in 24 (67%) cases for the time attenuation curves in the ischemic core, in 2 cases for the arterial input function and in 5 cases for the venous output function. Analysis of extended data resulted in smaller ischemic cores and larger penumbras with a median difference of 13.2 (IQR: 4.3–26.0)ml (P<0.001) and; 12.4 (IQR: 4.1–25.7)ml (P<0.001), respectively. The phantom data showed increasing ischemic core overestimation with increasing tissue time attenuation curve truncation. Conclusions Truncation is common in patients with large vessel occlusion and results in repartitioning of the area of hypoperfusion into larger ischemic core and smaller penumbra estimations. Phantom experiments confirmed that truncation results in overestimation of the ischemic core. PMID

  15. Deferasirox for Treating Patients Who Have Undergone Allogeneic Stem Cell Transplant and Have Iron Overload

    ClinicalTrials.gov

    2012-07-16

    Iron Overload; Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Atypical Chronic Myeloid Leukemia, BCR-ABL Negative; Blastic Phase Chronic Myelogenous Leukemia; Chronic Eosinophilic Leukemia; Chronic Myelomonocytic Leukemia; Chronic Neutrophilic Leukemia; Chronic Phase Chronic Myelogenous Leukemia; de Novo Myelodysplastic Syndromes; Disseminated Neuroblastoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Nodal Marginal Zone B-cell Lymphoma; Noncontiguous Stage II Adult Burkitt Lymphoma; Noncontiguous Stage II Adult Diffuse Large Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Mixed Cell Lymphoma; Noncontiguous Stage II Adult Diffuse Small Cleaved Cell Lymphoma; Noncontiguous Stage II Adult Immunoblastic Large Cell Lymphoma; Noncontiguous Stage II Adult Lymphoblastic Lymphoma; Noncontiguous Stage II Grade 1 Follicular Lymphoma; Noncontiguous Stage II Grade 2 Follicular Lymphoma; Noncontiguous Stage II Grade 3 Follicular Lymphoma; Noncontiguous Stage II Mantle Cell Lymphoma; Noncontiguous Stage II Marginal Zone Lymphoma; Noncontiguous Stage II Small Lymphocytic Lymphoma; Poor Prognosis Metastatic Gestational Trophoblastic Tumor; Previously Treated Myelodysplastic Syndromes; Primary Myelofibrosis; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult

  16. Immediate Consequences of Acute Kidney Injury: The Impact of Traditional and Nontraditional Complications on Mortality in Acute Kidney Injury.

    PubMed

    Faubel, Sarah; Shah, Pratik B

    2016-05-01

    Acute kidney injury (AKI) that requires renal replacement therapy is associated with a mortality rate that exceeds 50% in the intensive care unit, which is greater than other serious illnesses such as acute lung injury and myocardial infarction. Much information is now available regarding the complications of AKI that contribute to mortality and may be usefully categorized as "traditional" and "nontraditional". Traditional complications are the long-recognized complications of AKI such as hyperkalemia, acidosis, and volume overload, which may be typically corrected with renal replacement therapy. "Nontraditional" complications include complications such as sepsis, lung injury, and heart failure that may arise due to the effects of AKI on inflammatory cytokines, immune function, and cell death pathways such as apoptosis. In this review, we discuss both traditional and nontraditional complications of AKI with a focus on factors that contribute to mortality, considering both pathophysiology and potential remedies. Because AKI is the most common inpatient consult to nephrologists, it is essential to be aware of the complications of AKI that contribute to mortality to devise appropriate treatment strategies to prevent and manage AKI complications with the ultimate goal of reducing the unacceptably high mortality rate of AKI. PMID:27113694

  17. Effect of band-overload on fatigue crack growth rate of HSLA steel

    NASA Astrophysics Data System (ADS)

    Abhinay, S. V.; Tenduwe, Om Prakash; Kumar, Ajit; Dutta, K.; Verma, B. B.; Ray, P. K.

    2015-02-01

    Fatigue crack growth behavior is important parameter of structural materials. This parameters can be used to predict their life, service reliability and operational safety in different conditions. The material used in this investigation is an HSLA steel. In this investigation effect of single overload and band-overload on fatigue crack growth of same steel are studied using compact tension (CT) specimens under mode-I condition and R=0.3. It is observed that overload and band-overload applications resulted retardation on the fatigue crack growth rate in most of the cases. It is also noticed that maximum retardation took place on application of seven successive overload cycles. Application of ten and more overload cycles caused no crack growth retardation.

  18. The relevance of the rat lung response to particle overload for human risk assessment: a workshop consensus report.

    PubMed

    2000-01-01

    On 23-24 March 1998, the International Life Sciences Institute (ILSI) Risk Science Institute convened a workshop entitled "Relevance of the Rat Lung Response to Particle Overload for Human Risk Assessment." The workshop addressed the numerous study reports of lung tumors in rats resulting from chronic inhalation exposures to poorly soluble, nonfibrous particles of low acute toxicity and not directly genotoxic. These poorly soluble particles, indicated by the acronym PSPs (e.g., carbon black, coal dust, diesel soot, nonasbestiform talc, and titanium dioxide), elicit tumors in rats when deposition overwhelms the clearance mechanisms of the lung resulting in a condition referred to as "overload." These PSPs have been shown not to induce tumors in mice and hamsters, and the available data in humans are consistently negative. The objectives were twofold: (1) to provide guidance for risk assessment on the interpretation of neoplastic and nonneoplastic responses of the rat lung to PSPs; and (2) to identify important data gaps in our understanding of the lung responses of rats and other species to PSPs. Utilizing the five critical reviews of relevant literature that follow herein and the combined expertise and experience of the 30 workshop participants, a number of questions were addressed. The consensus views of the workshop participants are presented in this report. Because it is still not known with certainty whether high lung burdens of PSPs can lead to lung cancer in humans via mechanisms similar to those of the rat, in the absence of mechanistic data to the contrary it must be assumed that the rat model can identify potential carcinogenic hazards to humans. Since the apparent responsiveness of the rat model at overload is dependent on coexistent chronic active inflammation and cell proliferation, at lower lung doses where chronic active inflammation and cell proliferation are not present, no lung cancer hazard is anticipated. PMID:10715616

  19. Pulmonary macrophages: Phenomena associated with the particle overload'' condition

    SciTech Connect

    Lehnert, B.E.; Sebring, R.J. ); Oberdoerster, G. )

    1993-01-01

    Numerous lines of evidence support the generalization that alveolar macrophage (AM)-mediated particle clearance, or the transport of particle-containing AM from the alveoli out of the lung via the mucociliary apparatus, is a prominent mechanism that determines the pulmonary retention characteristics of relatively insoluble particles. Studies have also shown that the alveolar deposition of excessive burdens of particles with even low intrinsic cytotoxicity can result in impairments of the AM-mediated panicle clearance mechanism and the development of pathologic disorders including pulmonary fibrosis and lung cancer, at least in the lungs of rats. We briefly review evidence consistent with the idea that the high volumetric loads of particles contained in AM during particle overload conditions underlies their inabilities to translocate from the lung. Using a condition of particle overload brought about by subchronic exposure of rats to ultra-fine titanium dioxide as an experimental model, we have obtained ultrastructural and other evidence that indicates an association between particle overload and: The occurrence of aggregates of particle-containing AM in alveoli, Type II cell hyperplasia in alveoli that contain the AM aggregates, a loss in patent pores of Kohn in alveoli that contain the AM aggregates and show Type II cell hyperplasia, the interstitialization of particles at the sites where these phenomena collectively occur, and the development of fibrosis in alveolar regions where particle interstitialization occurs. The loss of pores of Kohn in the alveoli that contain aggregates of particle-laden AM suggests that these interalveolar pores normally serve as passageways through which AM may migrate to neighboring alveoli as they perform their function of phagocytizing particles that have deposited on the alveolar surface. The pores of Kohn also serve as short-cut pathways for AM to reach the mucociliary apparatus from more distal alveoli.

  20. Pulmonary macrophages: Phenomena associated with the particle ``overload`` condition

    SciTech Connect

    Lehnert, B.E.; Sebring, R.J.; Oberdoerster, G.

    1993-05-01

    Numerous lines of evidence support the generalization that alveolar macrophage (AM)-mediated particle clearance, or the transport of particle-containing AM from the alveoli out of the lung via the mucociliary apparatus, is a prominent mechanism that determines the pulmonary retention characteristics of relatively insoluble particles. Studies have also shown that the alveolar deposition of excessive burdens of particles with even low intrinsic cytotoxicity can result in impairments of the AM-mediated panicle clearance mechanism and the development of pathologic disorders including pulmonary fibrosis and lung cancer, at least in the lungs of rats. We briefly review evidence consistent with the idea that the high volumetric loads of particles contained in AM during particle overload conditions underlies their inabilities to translocate from the lung. Using a condition of particle overload brought about by subchronic exposure of rats to ultra-fine titanium dioxide as an experimental model, we have obtained ultrastructural and other evidence that indicates an association between particle overload and: The occurrence of aggregates of particle-containing AM in alveoli, Type II cell hyperplasia in alveoli that contain the AM aggregates, a loss in patent pores of Kohn in alveoli that contain the AM aggregates and show Type II cell hyperplasia, the interstitialization of particles at the sites where these phenomena collectively occur, and the development of fibrosis in alveolar regions where particle interstitialization occurs. The loss of pores of Kohn in the alveoli that contain aggregates of particle-laden AM suggests that these interalveolar pores normally serve as passageways through which AM may migrate to neighboring alveoli as they perform their function of phagocytizing particles that have deposited on the alveolar surface. The pores of Kohn also serve as short-cut pathways for AM to reach the mucociliary apparatus from more distal alveoli.

  1. Quantum Overloading Cryptography Using Single-Photon Nonlocality

    NASA Astrophysics Data System (ADS)

    Tan, Yong-Gang; Cai, Qing-Yu; Shi, Ting-Yun

    2007-08-01

    Using the single-photon nonlocality, we propose a quantum novel overloading cryptography scheme, in which a single photon carries two bits information in one-way quantum channel. Two commutative modes of the single photon, the polarization mode and the spatial mode, are used to encode secret information. Strict time windows are set to detect the impersonation attack. The spatial mode which denotes the existence of photons is noncommutative with the phase of the photon, so that our scheme is secure against photon-number-splitting attack. Our protocol may be secure against individual attack.

  2. Quantification of severe liver iron overload using MRI offset echoes

    PubMed Central

    Rydén, Henric

    2015-01-01

    Magnetic resonance imaging (MRI) has become the clinical standard to estimate liver iron overload. The most commonly used method is to measure the transversal relaxation time, T2*, from a multi gradient recalled echo sequence (MGRE). While this technique is reliable in low to moderate liver iron concentrations (LIC), it will be inaccurate when it is severe. We report a case with severe liver hemochromatosis and show the benefit of using an easily implemented MRI offset echo sequence to more accurately estimate LIC. After adjusting treatment, both Ferritin and LIC decreased. Using standard MGRE this reduction could not have been detected. PMID:26060576

  3. Use of Magnetic Resonance Imaging to Monitor Iron Overload

    PubMed Central

    Wood, John C.

    2014-01-01

    SYNOPSIS Treatment of iron overload requires robust estimates of total body iron burden and its response to iron chelation therapy. Compliance with chelation therapy varies considerably among patients and individual reporting is notoriously unreliable. Even with perfect compliance, intersubject variability in chelator effectiveness is extremely high, necessitating reliable iron estimates to guide dose titration. In addition, each chelator has a unique profile with respect to clearing iron stores from different organs. This chapter will present the tools available to clinicians monitoring their patients, focusing on non-invasive magnetic resonance imaging methods because they have become the de-facto standard of care. PMID:25064711

  4. Optimizing the diagnosis and the treatment of iron overload diseases.

    PubMed

    Brissot, Pierre

    2016-03-01

    A number of human disorders are related to chronic iron overload, either of genetic or acquired origin. The multi-organ damage produced by iron excess leads, in adults and in children, to severe clinical consequences, affecting both quality of life and life expectancy. The diagnosis is increasingly based on a non-invasive strategy, resorting to clinical, biological and imaging data. The treatment rests on either venesection or chelation therapy, depending on the etiology. Major advances in the fields of molecular biology, pharmacology, and biotechnology pave the road for key improvements in the diagnostic and therapeutic management of the patients. PMID:26561304

  5. Quantification of severe liver iron overload using MRI offset echoes.

    PubMed

    Rydén, Henric; Skorpil, Mikael

    2015-05-01

    Magnetic resonance imaging (MRI) has become the clinical standard to estimate liver iron overload. The most commonly used method is to measure the transversal relaxation time, T2*, from a multi gradient recalled echo sequence (MGRE). While this technique is reliable in low to moderate liver iron concentrations (LIC), it will be inaccurate when it is severe. We report a case with severe liver hemochromatosis and show the benefit of using an easily implemented MRI offset echo sequence to more accurately estimate LIC. After adjusting treatment, both Ferritin and LIC decreased. Using standard MGRE this reduction could not have been detected. PMID:26060576

  6. [The prevention of transfusion-associated circulatory overload].

    PubMed

    Ozier, Y

    2014-11-01

    Hydrostatic pulmonary edema is a frequent and severe complication of blood transfusion. Recent epidemiological studies open the way for a better prevention of Transfusion-Associated Circulatory Overload. Preventive measures rely solely on the medical and nursing staff. Mitigation strategies include a careful identification of patients and conditions at-risk, a single-unit transfusion policy in patients with chronic anemia, the use of slow infusion rates, the careful monitoring of patient vital signs (particularly systemic arterial blood pressure). Peritransfusion IV diuretics use is likely to be helpful, although optimal prescribing patterns have not been defined. PMID:25277421

  7. Modelling and measurement of crack closure and crack growth following overloads and underloads

    NASA Technical Reports Server (NTRS)

    Dexter, R. J.; Hudak, S. J.; Davidson, D. L.

    1989-01-01

    Ignoring crack growth retardation following overloads can result in overly conservative life predictions in structures subjected to variable amplitude fatigue loading. Crack closure is believed to contribute to the crack growth retardation, although the specific closure mechanism is dabatable. The delay period and corresponding crack growth rate transients following overload and overload/underload cycles were systematically measured as a function of load ratio and overload magnitude. These responses are correlated in terms of the local 'driving force' for crack growth, i.e. the effective stress intensity factor range. Experimental results are compared with the predictions of a Dugdale-type (1960) crack closure model, and improvements in the model are suggested.

  8. MRI-based Selection for Intra-arterial Stroke Therapy: Value of Pre-treatment DWI Lesion Volume in Selecting Acute Stroke Patients Who Will Benefit from Early Recanalization

    PubMed Central

    Yoo, Albert J.; Verduzco, Luis A.; Schaefer, Pamela W.; Hirsch, Joshua A.; Rabinov, James D.; González, R. Gilberto

    2009-01-01

    Background and Purpose Recent studies demonstrate that an acute diffusion weighted imaging(DWI) lesion volume >70cm3 predicts poor outcome in stroke patients. We sought to determine if this threshold could identify patients treated with intra-arterial therapy(IAT) who would do poorly despite reperfusion. In patients with initial infarcts <70cm3, we sought to determine what effect recanalization and time to recanalization had on infarct growth and functional outcome. Methods We retrospectively studied 34 consecutive anterior circulation stroke patients who underwent pre-treatment DWI and perfusion weighted imaging(PWI) and subsequent IAT. Recanalization success and time to recanalization were recorded. Initial DWI and MTT lesion and final infarct volumes were determined. Patients were stratified based on initial infarct volume, recanalization status and time to recanalization. Statistical tests were performed to assess differences in clinical and imaging outcomes. Good clinical outcome was defined as a 3-month mRS≤2. Results Among patients with initial infarcts >70cm3, all had poor outcomes despite a 50% recanalization rate, with mean infarct growth of 114cm3. These patients also had the largest MTT volumes(p<0.04). Patients with initial infarct volumes <70cm3 who recanalized early had the best clinical outcomes(p<0.008) with a 64% rate of mRS≤2 and the least infarct growth(p<0.03), with mean growth of 18cm3. Conclusion This study supports the use of an acute DWI lesion volume threshold as an imaging selection criterion for IAT. It also confirms the importance of early reperfusion in selected patients. PMID:19359641

  9. Information overload in healthcare: too much of a good thing?

    PubMed

    Klerings, Irma; Weinhandl, Alexandra S; Thaler, Kylie J

    2015-01-01

    The rapidly growing production of healthcare information - both scientific and popular - increasingly leads to a situation of information overload affecting all actors of the healthcare system and threatening to impede the adoption of evidence-based practice. In preparation for the 2015 Cochrane Colloquium in Vienna, we discuss the issues faced by three major actors of this system: patients, healthcare practitioners, and systematic reviewers. We analyze their situation through the concept of "filter failure", positing that the main problem is not that there is "too much information", but that the traditional means of managing and evaluating information are ill-suited to the realities of the digital age. Some of the major instances of filter failure are inadequate information retrieval systems for point-of-care settings, the problem of identifying all relevant evidence in an exceedingly diverse landscape of information resources, and the very basic lack of health information literacy, concerning not only the general public. Finally, we give an overview of proposed solutions to the problem of information overload. These new or adapted filtering systems include adapting review literature to the specific needs of practitioners or patients, technological improvements to information systems, strengthening the roles of intermediaries, as well as improving health literacy. PMID:26354128

  10. Iron overload diminishes atherosclerosis in apoE-deficient mice

    PubMed Central

    Kirk, Elizabeth A.; Heinecke, Jay W.; LeBoeuf, Renée C.

    2001-01-01

    It has been proposed that elevated levels of tissue iron increase the risk for atherosclerosis, perhaps by favoring the formation of pro-atherogenic oxidized LDL. Working with apoE-deficient (apoE–/–) mice, which do not require a high-fat diet to develop atherosclerosis, we compared the effects of standard diet (0.02% iron) or a 2% carbonyl iron diet. After 24 weeks, mice fed the 2% carbonyl iron diet had twice as much iron in their plasma, a ninefold increase in bleomycin-detectable free iron in their plasma, and ten times as much iron in their livers as control mice. Dietary iron overload caused a modest (30%) rise in plasma triglyceride and cholesterol. Nevertheless, this regimen did not exacerbate, but rather reduced the severity of atherosclerosis by 50%, and it failed to elevate hepatic levels of heme oxygenase mRNA, which is induced by many different oxidative insults in vitro. Moreover, hepatic levels of protein-bound dityrosine and ortho-tyrosine, two markers of metal-catalyzed oxidative damage in vitro, failed to rise in iron-overloaded animals. Our observations suggest that elevated serum and tissue levels of iron are not atherogenic in apoE–/– mice. Moreover, they call into question the hypothesis that elevated levels of tissue iron promote LDL oxidation and oxidative stress in vivo. PMID:11413162

  11. [Occlusal overload--a risk factor in implant based prostheses].

    PubMed

    Dănilă, V; Augustin, M

    2010-01-01

    The aim of the study was to perform a review of the literature data in regard to the main causes leading to failure of the dental implants and subsequently, of the implant based prostheses. Besides biological risk factors as infection, occlusal overload is considered the main mechanical risk factor being responsible for weakening or fracturing of the fixation screws, fracturing of the prosthesis or even of the implants. Understanding the fundamental differences between the natural dental structures and the implants may lead to a rigorous occlusal control as a key factor to success of implant born prosthesis. Among these, the periodontal ligament is of outmost importance because it allows a physiological-functional adjustment of occlusal stress in the longitudinal axis of the natural teeth and adaptation to the occlusal stress changes. In conclusion, the absence of periodontal ligament may lead to occlusal overload and implant failure due to lack of adjustment of occlusal forces intensity and axial transmission of these forces, as well as the absence of periodontal proprioceptors. PMID:20509305

  12. Criterion validation of a stress measure: the Stress Overload Scale.

    PubMed

    Amirkhan, James H; Urizar, Guido G; Clark, Sarah

    2015-09-01

    Validating stress scales poses problems beyond those of other psychological measures. Here, 3 studies were conducted to address those problems and assess the criterion validity of scores from a new theory-derived measure, the Stress Overload Scale (SOS; Amirkhan, 2012). In Study 1, the SOS was tested for its ability to predict postsemester illness in a sample of college students (n = 127). Even with precautions to minimize criterion contamination, scores were found to predict health problems in the month following a final exam on all of 5 different criteria. In Study 2, a community sample (n = 231) was used to test the SOS' ability to differentiate people in stressful circumstances from those in more relaxed contexts. SOS scores demonstrated excellent sensitivity (96%) and specificity (100%) in this general population application. In Study 3, the SOS was tested for its ability to differentiate salivary cortisol responses to a laboratory stressor in a group of pregnant women (n = 40). High scores were found to be associated with a blunted cortisol response, which is indicative of HPA-axis overload and typical of persons suffering chronic stress and stress-related pathology. Across all 3 studies, despite variations in the stressor, criterion, population, and methods, SOS scores emerged as valid indicators of stress. However, each study also introduced new problems that beg additional corrective steps in future stress-scale validity tests. These strategies, and the SOS' utility as a research and diagnostic tool in varied applications and populations, are discussed. PMID:25642927

  13. Functional Overload Enhances Satellite Cell Properties in Skeletal Muscle.

    PubMed

    Fujimaki, Shin; Machida, Masanao; Wakabayashi, Tamami; Asashima, Makoto; Takemasa, Tohru; Kuwabara, Tomoko

    2016-01-01

    Skeletal muscle represents a plentiful and accessible source of adult stem cells. Skeletal-muscle-derived stem cells, termed satellite cells, play essential roles in postnatal growth, maintenance, repair, and regeneration of skeletal muscle. Although it is well known that the number of satellite cells increases following physical exercise, functional alterations in satellite cells such as proliferative capacity and differentiation efficiency following exercise and their molecular mechanisms remain unclear. Here, we found that functional overload, which is widely used to model resistance exercise, causes skeletal muscle hypertrophy and converts satellite cells from quiescent state to activated state. Our analysis showed that functional overload induces the expression of MyoD in satellite cells and enhances the proliferative capacity and differentiation potential of these cells. The changes in satellite cell properties coincided with the inactivation of Notch signaling and the activation of Wnt signaling and likely involve modulation by transcription factors of the Sox family. These results indicate the effects of resistance exercise on the regulation of satellite cells and provide insight into the molecular mechanism of satellite cell activation following physical exercise. PMID:26779264

  14. Competing for Attention in Social Media under Information Overload Conditions.

    PubMed

    Feng, Ling; Hu, Yanqing; Li, Baowen; Stanley, H Eugene; Havlin, Shlomo; Braunstein, Lidia A

    2015-01-01

    Modern social media are becoming overloaded with information because of the rapidly-expanding number of information feeds. We analyze the user-generated content in Sina Weibo, and find evidence that the spread of popular messages often follow a mechanism that differs from the spread of disease, in contrast to common belief. In this mechanism, an individual with more friends needs more repeated exposures to spread further the information. Moreover, our data suggest that for certain messages the chance of an individual to share the message is proportional to the fraction of its neighbours who shared it with him/her, which is a result of competition for attention. We model this process using a fractional susceptible infected recovered (FSIR) model, where the infection probability of a node is proportional to its fraction of infected neighbors. Our findings have dramatic implications for information contagion. For example, using the FSIR model we find that real-world social networks have a finite epidemic threshold in contrast to the zero threshold in disease epidemic models. This means that when individuals are overloaded with excess information feeds, the information either reaches out the population if it is above the critical epidemic threshold, or it would never be well received. PMID:26161956

  15. Tumour promotion versus tumour suppression in chronic hepatic iron overload.

    PubMed

    Bloomer, Steven A; Brown, Kyle E

    2015-06-01

    Although iron-catalysed oxidative damage is presumed to be a major mechanism of injury leading to cirrhosis and hepatocellular carcinoma in hemochromatosis, these events have been difficult to recapitulate in an animal model. In this study, we evaluated regulators of hepatocarcinogenesis in a rodent model of chronic iron overload. Sprague-Dawley rats were iron loaded with iron dextran over 6 months. Livers were harvested and analysed for markers of oxidative stress, as well as the following proteins: p53, murine double minute 2, the Shc proteins p66, p52, p46; β-catenin, CHOP, C/EBPα and Yes-associated protein. In this model, iron loading is associated with hepatocyte proliferation, and indices of oxidative damage are mildly increased in tandem with augmented antioxidant defenses. Alterations potentially favouring carcinogenesis included a modest but significant decrease in p53 levels and increases in p52, p46 and β-catenin levels compared with control livers. Countering these factors, the iron-loaded livers demonstrated a significant decrease in CHOP, which has recently been implicated in the development of hepatocellular carcinoma, as well as a reciprocal increase in C/EBPα and decrease in Yes-associated protein. Our results suggest that chronic iron overload elicits both tumour suppressive as well as tumour-promoting mechanisms in rodent liver. PMID:26059599

  16. Fatty acids exacerbate tubulointerstitial injury in protein-overload proteinuria.

    PubMed

    Thomas, Mark E; Harris, Kevin P G; Walls, John; Furness, Peter N; Brunskill, Nigel J

    2002-10-01

    The role of the albumin-carried fatty acids in the induction of tubulointerstitial injury was studied in protein-overload proteinuria. Rats were injected with fatty acid-carrying BSA [FA(+)BSA], fatty acid-depleted BSA [FA(-)BSA], or saline. Macrophage infiltration was measured by immunohistochemical staining, apoptotic cells were detected by in situ end labeling, and proliferating cells were identified by in situ hybridization for histone mRNA. Macrophage infiltration was significantly greater in the FA(+)BSA group than in the FA(-)BSA and saline groups. The infiltrate was largely restricted to the outer cortex. Apoptosis was greater in the FA(+)BSA group than in the FA(-)BSA and saline groups. Compared with the saline group, apoptosis was significantly increased in the FA(+)BSA group but not in the FA(-)BSA group. Cortical cells proliferated significantly more in the FA(+)BSA and FA(-)BSA groups than in the saline group. FA(+)BSA is therefore a more potent inducer of macrophage infiltration and cell death than FA(-)BSA. The fatty acids carried on albumin may be the chief instigators of tubulointerstitial injury in protein-overload proteinuria. PMID:12217854

  17. Competing for Attention in Social Media under Information Overload Conditions

    PubMed Central

    Feng, Ling; Hu, Yanqing; Li, Baowen; Stanley, H. Eugene; Havlin, Shlomo; Braunstein, Lidia A.

    2015-01-01

    Modern social media are becoming overloaded with information because of the rapidly-expanding number of information feeds. We analyze the user-generated content in Sina Weibo, and find evidence that the spread of popular messages often follow a mechanism that differs from the spread of disease, in contrast to common belief. In this mechanism, an individual with more friends needs more repeated exposures to spread further the information. Moreover, our data suggest that for certain messages the chance of an individual to share the message is proportional to the fraction of its neighbours who shared it with him/her, which is a result of competition for attention. We model this process using a fractional susceptible infected recovered (FSIR) model, where the infection probability of a node is proportional to its fraction of infected neighbors. Our findings have dramatic implications for information contagion. For example, using the FSIR model we find that real-world social networks have a finite epidemic threshold in contrast to the zero threshold in disease epidemic models. This means that when individuals are overloaded with excess information feeds, the information either reaches out the population if it is above the critical epidemic threshold, or it would never be well received. PMID:26161956

  18. Immune overload: Parental attitudes toward combination and single antigen vaccines.

    PubMed

    Hulsey, Ella; Bland, Tami

    2015-05-21

    Parental concerns have led to a recent decline in immunization coverage, resulting in outbreaks of diseases that were once under control in the US. As the CDC vaccination schedule continues to increase in complexity, the number of required injections per office visit increases as well. Some parents perceive that there is trauma associated with the administration of multiple injections, and research shows that having multiple vaccines due in a single visit is associated with delays and lower immunization rates. Combination vaccines make vaccination more efficient by incorporating the antigens of several different diseases into a single injection, but many parents worry that they may overload the child's developing immune system and leave him or her susceptible to secondary infections. This literature review synthesizes current evidence regarding the parental fear of vaccine-induced immune system overload and the fear of vaccine-associated trauma, in an attempt to understand the scope and nature of these fears. Despite the wealth of knowledge about each of these fears individually, it is still unknown which is of greater concern and how this affects parental decision-making. PMID:25891399

  19. Dietary glutamine supplementation partly reverses impaired macrophage function resulting from overload training in rats.

    PubMed

    Xiao, Weihua; Chen, Peijie; Dong, Jingmei; Wang, Ru; Luo, Beibei

    2015-04-01

    The aim of this study was to evaluate the effect of overload training on the function of peritoneal macrophages in rats, and to test the hypothesis that glutamine in vivo supplementation would partly reverse the eventual functional alterations induced by overload training in these cells. Forty male Wistar rats were randomly divided into 5 groups: control group (C), overload training group (E1), overload training and restore one week group (E2), glutamine-supplementation group (EG1), and glutamine-supplementation and restore 1-week group (EG2). All rats, except those placed on sedentary control were subjected to 11 weeks of overload training protocol. Blood hemoglobin, serum testosterone, and corticosterone of rats were measured. Moreover, the functions (chemotaxis, phagocytosis, cytokines synthesis, reactive oxygen species generation) of peritoneal macrophages were determined. Data showed that blood hemoglobin, serum testosterone, corticosterone and body weight in the overload training group decreased significantly as compared with the control group. Meanwhile, the chemotaxis capacity (decreased by 31%, p = .003), the phagocytosis capacity (decreased by 27%, p = .005), the reactive oxygen species (ROS) generation (decreased by 35%, p = .003) and the cytokines response capability of macrophages were inhibited by overload training. However, the hindering of phagocytosis and the cytokines response capability of macrophages induced by overload training could be ameliorated and reversed respectively, by dietary glutamine supplementation. These results suggest that overload training impairs the function of peritoneal macrophages, which is essential for the microbicidal actions of macrophages. This may represent a novel mechanism of immunodepression induced by overload training. Nonetheless, dietary glutamine supplementation could partly reverse the impaired macrophage function resulting from overload training. PMID:25028814

  20. Adipocyte ALK7 links nutrient overload to catecholamine resistance in obesity

    PubMed Central

    Guo, Tingqing; Marmol, Patricia; Moliner, Annalena; Björnholm, Marie; Zhang, Chao; Shokat, Kevan M; Ibanez, Carlos F

    2014-01-01

    Obesity is associated with blunted β-adrenoreceptor (β-AR)-mediated lipolysis and lipid oxidation in adipose tissue, but the mechanisms linking nutrient overload to catecholamine resistance are poorly understood. We report that targeted disruption of TGF-β superfamily receptor ALK7 alleviates diet-induced catecholamine resistance in adipose tissue, thereby reducing obesity in mice. Global and fat-specific Alk7 knock-out enhanced adipose β-AR expression, β-adrenergic signaling, mitochondrial biogenesis, lipid oxidation, and lipolysis under a high fat diet, leading to elevated energy expenditure, decreased fat mass, and resistance to diet-induced obesity. Conversely, activation of ALK7 reduced β-AR-mediated signaling and lipolysis cell-autonomously in both mouse and human adipocytes. Acute inhibition of ALK7 in adult mice by a chemical-genetic approach reduced diet-induced weight gain, fat accumulation, and adipocyte size, and enhanced adipocyte lipolysis and β-adrenergic signaling. We propose that ALK7 signaling contributes to diet-induced catecholamine resistance in adipose tissue, and suggest that ALK7 inhibitors may have therapeutic value in human obesity. DOI: http://dx.doi.org/10.7554/eLife.03245.001 PMID:25161195

  1. Shensong Yangxin capsules prevent ischemic arrhythmias by prolonging action potentials and alleviating Ca2+ overload.

    PubMed

    Zhao, Yixiu; Gao, Feng; Zhang, Yong; Wang, Hongtao; Zhu, Jiuxin; Chang, Liping; Du, Zhimin; Zhang, Yan

    2016-06-01

    Shensong Yangxin capsules (SSYX) are an effective traditional Chinese medicine that has been used to treat coronary heart disease clinically. The present study aimed to establish whether SSYX prevent ischemic arrhythmias in rats, and to explore the underlying mechanisms. Male rats were pretreated with distilled water, SSYX and amiodarone for one week. Acute myocardial ischemia (AMI) was performed to induce ischemic arrhythmias. The incidence and severity of ischemic arrhythmias were evaluated. The action potential, transient outward K+ current (Ito) and inward rectifier K+ current (IK1) of rat cardiomyocytes were measured using the patch‑clamp technique. The intracellular Ca2+ concentration of the cardiomyocytes was measured using a laser scanning confocal microscope. The results revealed that SSYX lowered the incidence of arrhythmia markedly during AMI. Furthermore, SSYX delayed the appearance, and reduced the severity, of ischemic arrhythmias compared with the control. In addition, SSYX markedly decreased the ratio of the myocardial infarction region to the whole heart. In an in vitro study, SSYX prolonged the action potential duration of rat cardiomyocytes, and inhibited Ito and IK1 markedly. Additionally, SSYX inhibited Ca2+ elevation induced by KCl in cardiomyocytes. These results suggested that SSYX prevents ischemic arrhythmia, and the underlying mechanism responsible for this process may include prolonging the action potential and alleviating Ca2+ overload. PMID:27122298

  2. Inhibition of transforming growth factor-beta signaling induces left ventricular dilation and dysfunction in the pressure-overloaded heart.

    PubMed

    Lucas, Jason A; Zhang, Yun; Li, Peng; Gong, Kaizheng; Miller, Andrew P; Hassan, Erum; Hage, Fadi; Xing, Dongqi; Wells, Bryan; Oparil, Suzanne; Chen, Yiu-Fai

    2010-02-01

    This study utilized a transgenic mouse model that expresses an inducible dominant-negative mutation of the transforming growth factor (TGF)-beta type II receptor (DnTGFbetaRII) to define the structural and functional responses of the left ventricle (LV) to pressure-overload stress in the absence of an intact TGF-beta signaling cascade. DnTGFbetaRII and nontransgenic (NTG) control mice (male, 8-10 wk) were randomized to receive Zn(2+) (25 mM ZnSO(4) in drinking H(2)O to induce DnTGFbetaRII gene expression) or control tap H(2)O and then further randomized to undergo transverse aortic constriction (TAC) or sham surgery. At 7 days post-TAC, interstitial nonmyocyte proliferation (Ki67 staining) was greatly reduced in LV of DnTGFbetaRII+Zn(2+) mice compared with the other TAC groups. At 28 and 120 days post-TAC, collagen deposition (picrosirius-red staining) in LV was attenuated in DnTGFbetaRII+Zn(2+) mice compared with the other TAC groups. LV end systolic diameter and end systolic and end diastolic volumes were markedly increased, while ejection fraction and fractional shortening were significantly decreased in TAC-DnTGFbetaRII+Zn(2+) mice compared with the other groups at 120 days post-TAC. These data indicate that interruption of TGF-beta signaling attenuates pressure-overload-induced interstitial nonmyocyte proliferation and collagen deposition and promotes LV dilation and dysfunction in the pressure-overloaded heart, thus creating a novel model of dilated cardiomyopathy. PMID:19933419

  3. I just want to be left alone: Daily overload and marital behavior.

    PubMed

    Sears, Meredith S; Repetti, Rena L; Robles, Theodore F; Reynolds, Bridget M

    2016-08-01

    Stressful, busy days have been linked with increases in angry and withdrawn marital behavior. The process by which stressors in 1 domain, such as work, affect an individual's behavior in another domain, such as the marital relationship, is known as. Using 56 days of daily diary reports in a diverse sample of 47 wives and 39 husbands, this study examined associations between daily experiences of overload and 3 marital behaviors: overt expressions of anger, disregard of the spouse's needs ("disregard"), and reductions in affection and disclosure ("distancing"). Two potential mechanisms by which daily overload spills over into marital behavior were examined: negative mood and the desire to avoid social interaction. Among husbands, negative mood mediated the association between overload and angry behavior. Associations between overload and wives' angry behavior, as well as overload and husbands' and wives' disregard of their partners' needs, were mediated by both negative mood and the desire to withdraw socially. Desire to withdraw, but not negative mood, mediated the association between overload and distancing behavior among husbands and wives. In addition, associations between marital satisfaction and spouses' typical marital behavior, as well as behavioral responses to overload, were examined. Husbands' and wives' average levels of expressed anger and disregard, and husbands' distancing, were associated with lower marital satisfaction in 1 or both partners. Both spouses reported lower marital satisfaction if husbands tended to express marital anger, disregard, or distancing on busy, overloaded days. (PsycINFO Database Record PMID:27055182

  4. Data Overload Impact on Project Management: How Knowledge Management Systems Can Improve Federal Agencies Effectiveness

    ERIC Educational Resources Information Center

    Rodriguez, Jacinto

    2013-01-01

    This mixed method exploratory case study was used to explore the effect data overload has on project management, how data overload affects project management effectiveness, how prepared program office staff is to manage multiple projects effectively, and how the program office's organizational structure and data management systems affect project…

  5. "Something's Gotta Give:" Advanced-Degree Seeking Women's Experiences of Sexism, Role Overload, and Psychological Distress

    ERIC Educational Resources Information Center

    West, Lindsey M.

    2014-01-01

    With the rise in advanced-degree seeking women and the minimal research on the dual impact of sexism and role overload, the current study aims to better understand the impact of sexism and role overload on psychological distress in a particular sample of advanced-degree seeking women. Seventy-six female medical student participants (mean age 24.7)…

  6. Role Overload, Job Satisfaction, Leisure Satisfaction, and Psychological Health among Employed Women

    ERIC Educational Resources Information Center

    Pearson, Quinn M.

    2008-01-01

    Role overload, job satisfaction, leisure satisfaction, and psychological health were measured for 155 women who were employed full time. Role overload was negatively correlated with psychological health, job satisfaction, and leisure satisfaction. Job satisfaction and leisure satisfaction were positively correlated with psychological health.…

  7. Coping with Overload and Stress: Men and Women in Dual-Earner Families

    ERIC Educational Resources Information Center

    Higgins, Chris A.; Duxbury, Linda E.; Lyons, Sean T.

    2010-01-01

    This study tested gender differences in a model positing relationships between work and family demands, overload, 4 coping mechanisms, and stress. The coping mechanisms were hypothesized to moderate the relationship between overload and stress. The sample consisted of 1,404 men and 1,623 women in dual-earner families. Respondents relied on 2…

  8. 30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Incandescent lamps, overload and short circuit protection. 75.518-2 Section 75.518-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps...

  9. 30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Incandescent lamps, overload and short circuit protection. 75.518-2 Section 75.518-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps...

  10. 30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Incandescent lamps, overload and short circuit protection. 75.518-2 Section 75.518-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps...

  11. Learners' Perceived Information Overload in Online Learning via Computer-Mediated Communication

    ERIC Educational Resources Information Center

    Chen, Chun-Ying; Pedersen, Susan; Murphy, Karen L.

    2011-01-01

    Many studies report information overload as one of the main problems that students encounter in online learning via computer-mediated communication. This study aimed to explore the sources of online students' information overload and offer suggestions for increasing students' cognitive resources for learning. Participants were 12 graduate students…

  12. Spreading the Load: Mobile Information and Communications Technologies and Their Effect on Information Overload

    ERIC Educational Resources Information Center

    Allen, David K.; Shoard, M.

    2005-01-01

    Introduction: We report on a small-scale research project which examined the impact of mobile technologies on the users' experience of information overload. The project focused on a group of worker who have had relatively little attention in both the mobile technology and information overload literatures: senior managers. Method: The case study…

  13. Managing Information Overload for Senior Leaders in the 21st Century

    ERIC Educational Resources Information Center

    Jackson, Jason M.

    2013-01-01

    Information overload is a state where information input exceeds processing capability by an individual, and adverse effects of information overload, such as becoming less productive, making bad decisions, and becoming highly selective, are growing. Guided by Glaser and Strauss' work on grounded theory, this study examined adverse impact of…

  14. The Use of Graphs as Decision Aids in Relation to Information Overload and Managerial Decision Quality.

    ERIC Educational Resources Information Center

    Chan, Siu Y.

    2001-01-01

    Discussion of information overload focuses on a study of masters degree students at a Hong Kong university that investigated the effectiveness of graphs as decision aids to reduce adverse effects of information overload on decision quality. Results of a simulation of a business prediction task with a sample of business managers are presented.…

  15. 77 FR 11598 - Thermal Overload Protection for Electric Motors on Motor-Operated Valves

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-27

    ... function. II. Further Information DG-1264, was published in the Federal Register on May 02, 2011 (76 FR... COMMISSION Thermal Overload Protection for Electric Motors on Motor-Operated Valves AGENCY: Nuclear... (NRC or Commission) is issuing a revision to Regulatory Guide (RG) 1.106, ``Thermal Overload...

  16. Designing a Personalized Guide Recommendation System to Mitigate Information Overload in Museum Learning

    ERIC Educational Resources Information Center

    Huang, Yong-Ming; Liu, Chien-Hung; Lee, Chun-Yi; Huang, Yueh-Min

    2012-01-01

    Museum learning has received a lot of attention in recent years. Museum learning refers to people's use of museums to acquire knowledge. However, a problem with information overload has caused in engaging in such learning. Information overload signifies that users encounter a mass of information and need to determine whether certain information…

  17. 30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Incandescent lamps, overload and short circuit...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps installed... or direct current feeder circuits, need not be provided with separate short circuit or...

  18. 30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Incandescent lamps, overload and short circuit...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps installed... or direct current feeder circuits, need not be provided with separate short circuit or...

  19. Dietary copper supplementation reverses hypertrophic cardiomyopathy induced by chronic pressure overload in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustained pressure overload causes cardiac hypertrophy and the transition to heart failure. We show here that dietary supplementation with physiologically relevant levels of copper (Cu) reverses pre-established hypertrophic cardiomyopathy in the presence of pressure overload induced by ascending aor...

  20. Spatio-temporal propagation of cascading overload failures in spatially embedded networks.

    PubMed

    Zhao, Jichang; Li, Daqing; Sanhedrai, Hillel; Cohen, Reuven; Havlin, Shlomo

    2016-01-01

    Different from the direct contact in epidemics spread, overload failures propagate through hidden functional dependencies. Many studies focused on the critical conditions and catastrophic consequences of cascading failures. However, to understand the network vulnerability and mitigate the cascading overload failures, the knowledge of how the failures propagate in time and space is essential but still missing. Here we study the spatio-temporal propagation behaviour of cascading overload failures analytically and numerically on spatially embedded networks. The cascading overload failures are found to spread radially from the centre of the initial failure with an approximately constant velocity. The propagation velocity decreases with increasing tolerance, and can be well predicted by our theoretical framework with one single correction for all the tolerance values. This propagation velocity is found similar in various model networks and real network structures. Our findings may help to predict the dynamics of cascading overload failures in realistic systems. PMID:26754065

  1. Spatio-temporal propagation of cascading overload failures in spatially embedded networks

    NASA Astrophysics Data System (ADS)

    Zhao, Jichang; Li, Daqing; Sanhedrai, Hillel; Cohen, Reuven; Havlin, Shlomo

    2016-01-01

    Different from the direct contact in epidemics spread, overload failures propagate through hidden functional dependencies. Many studies focused on the critical conditions and catastrophic consequences of cascading failures. However, to understand the network vulnerability and mitigate the cascading overload failures, the knowledge of how the failures propagate in time and space is essential but still missing. Here we study the spatio-temporal propagation behaviour of cascading overload failures analytically and numerically on spatially embedded networks. The cascading overload failures are found to spread radially from the centre of the initial failure with an approximately constant velocity. The propagation velocity decreases with increasing tolerance, and can be well predicted by our theoretical framework with one single correction for all the tolerance values. This propagation velocity is found similar in various model networks and real network structures. Our findings may help to predict the dynamics of cascading overload failures in realistic systems.

  2. Spatio-temporal propagation of cascading overload failures in spatially embedded networks

    PubMed Central

    Zhao, Jichang; Li, Daqing; Sanhedrai, Hillel; Cohen, Reuven; Havlin, Shlomo

    2016-01-01

    Different from the direct contact in epidemics spread, overload failures propagate through hidden functional dependencies. Many studies focused on the critical conditions and catastrophic consequences of cascading failures. However, to understand the network vulnerability and mitigate the cascading overload failures, the knowledge of how the failures propagate in time and space is essential but still missing. Here we study the spatio-temporal propagation behaviour of cascading overload failures analytically and numerically on spatially embedded networks. The cascading overload failures are found to spread radially from the centre of the initial failure with an approximately constant velocity. The propagation velocity decreases with increasing tolerance, and can be well predicted by our theoretical framework with one single correction for all the tolerance values. This propagation velocity is found similar in various model networks and real network structures. Our findings may help to predict the dynamics of cascading overload failures in realistic systems. PMID:26754065

  3. Levonorgestrel-releasing intrauterine system and iron overload syndrome.

    PubMed

    Vieira da Motta, Marcia; Vieira da Motta, Eduardo

    2013-01-01

    Severe fatigue is a common complaint among patients. This report presents a clinical case of a woman complaining of fatigue associated with diarrhea and myalgia that were first attributed to emotional stress and depression. Initially, the patient was diagnosed with chronic fatigue and irritable bowel syndrome. The patient followed nutritional and physical exercise programs without any improvement. Other clinical conditions, such as nutritional deficiencies, endocrine dysfunctions, autoimmune diseases and neoplasias, were then assessed. During clinical investigation, serum ferritin and iron levels were abnormally elevated despite normal hemoglobin levels, which pointed to an iron overload syndrome later diagnosed as hemochromatosis. It is possible that the symptoms were triggered by the amenorrhea caused by the levonorgestrel-releasing intrauterine system used for contraception. PMID:23843714

  4. The membrane proteins of the overloaded and senescent heart.

    PubMed

    Chevalier, B; Charlemagne, D; Callens-el Amrani, F; Carre, F; Moalic, J M; Delcayre, C; Mansier, P; Swynghedauw, B

    1992-01-01

    Cardiac hypertrophy which occurs during chronic mechanical overload is one of the numerous examples of biological adaptation to environmental requirements. As such, it is obtained at random by trial and error, and adaptation represents the sum of various modifications in gene expression, including the shift in isoform of myosin or in iso Na+, K+ ATPase, the decrease in beta-adrenergic and muscarinic receptors, ryanodine channels or SR Ca2+ ATPase densities and the unchanged density in Ca2+ current. Some of these changes are beneficial at the cellular level, but are finally detrimental for the organism as a whole, as is the slowing of Vmax. It was suggested that the calcium homeostasis of the hypertrophied cardiocyte was fragile and that this modified cell was less able to buffer the changes in the intracellular calcium, thus providing a biological basis for the arrhythmogenicity of the hypertrophied heart. These various modifications may provide a new key for future pharmaceutical research. PMID:1323260

  5. Overcoming solubility limits in overloaded gradient hydrophobic interaction chromatography.

    PubMed

    Poplewska, Izabela; Piątkowski, Wojciech; Antos, Dorota

    2015-03-20

    The impact of the solubility limits on the performance of gradient protein chromatography has been studied. As a case study elution of model protein, i.e., lysozyme, on hydrophobic interaction media has been selected. A dependence of the protein solubility and crystallization kinetics on the content of cosmotropic salt in the mobile phase has been determined. Moreover, adsorption properties of the protein versus the mobile phase composition have been quantified. A model of chromatographic column dynamics has been developed which incorporated the mass transport kinetics accompanying both adsorption and crystallization processes. The model was used to study the influence of operating parameters such as flowrate and concentration loading on the solubility pattern inside the column and the separation performance. The analysis performed indicated existence of supersaturation regions for which, due to slow kinetics of crystallization, chromatographic process could be performed under conditions of strong concentration overloading while avoiding undesirable effects of flow blockage in chromatographic systems. PMID:25687455

  6. Chronic Kidney Disease, Fluid Overload and Diuretics: A Complicated Triangle

    PubMed Central

    Khan, Yusra Habib; Sarriff, Azmi; Adnan, Azreen Syazril; Khan, Amer Hayat; Mallhi, Tauqeer Hussain

    2016-01-01

    Background Despite promising role of diuretics to manage fluid overload among chronic kidney disease (CKD) patients, their use is associated with adverse renal outcomes. Current study aimed to determine the extent of renal deterioration with diuretic therapy. Methods A total 312 non-dialysis dependent CKD (NDD-CKD) patients were prospectively followed-up for one year. Fluid overload was assessed via bioimpedance spectroscopy. Estimated GFR (eGFR) was calculated from serum creatinine values by using Chronic Kidney Disease- Epidemiology Collaboration (CKD-EPI) equation. Results Out of 312 patients, 64 (20.5%) were hypovolemic while euvolemia and hypervolemia were observed in 113 (36.1%) and 135 (43.4%) patients. Overall 144 patients were using diuretics among which 98 (72.6%) were hypervolemic, 35 (30.9%) euvolemic and 11 (17.2%) were hypovolemic. The mean decline in estimated GFR of entire cohort was -2.5 ± 1.4 ml/min/1.73m2 at the end of follow up. The use of diuretics was significantly associated with decline in eGFR. A total of 36 (11.5%) patients initiated renal replacement therapy (RRT) and need of RRT was more profound among diuretic users. Conclusions The use of diuretics was associated with adverse renal outcomes indicated by decline in eGFR and increasing risk of RRT initiation in our cohort of NDD-CKD patients. Therefore, it is cautiously suggested to carefully prescribe diuretics by keeping in view benefit versus harm for each patient. PMID:27442587

  7. Effect of setting high APRV guided by expiratory inflection point of pressure-volume curve on oxygen delivery in canine models of severe acute respiratory distress syndrome

    PubMed Central

    Li, Jia-Qiong; Xu, Hong-Yang; Li, Mao-Qin; Chen, Jing-Yu

    2016-01-01

    In the present study, the effect of setting high airway pressure release ventilation (APRV) pressure guided by an expiratory inflection point of pressure-volume (PV) curve following lung recruitment maneuver (RM) on oxygen delivery (DO2) in canine models of severe acute respiratory distress syndrome (ARDS) was examined. Canine models of severe ARDS were established by intravenous injection of oleic acid. After injection of sedative muscle relaxants, a PV curve plotted using the super-syringe technique, and the pressure at lower inflection point (LIP) at the inhale branch and the pressure at the point of maximum curvature (PMC) at the exhale branch were measured. The ventilation mode was biphasic positive airway pressure (BiPAP), an inspiration to expiration ratio of 1:2, and Phigh 40 cm H2O, Plow 25 cm H2O. Phigh was decreased to 30 cm H2O after 90 sec. The dogs were randomized into 3 groups after RM, i.e., Blip group, BiPAP Plow = LIP+2 cm H2O; Bpmc group, BiPAP Plow = PMC; and Apmc group. In the APRV group, Phigh was set as PMC, with an inspiratory duration of 4 sec and expiratory duration of 0.4 sec. PMC was 18±1.4 cm H2O, and LIP was 11±1.3 cm H2O. Thirty seconds after RM was stabilized, it was set as 0 h. Hemodynamics, oxygenation and DO2 were measured at 0, 1, 2 and 4 h after RM in ARDS dogs. The results demonstrated: i) cardiac index (CI) in the 3 groups, where CI was significantly decreased in the Bpmc group at 0, 1, 2 and 4 h after RM compared to prior to RM (P<0.05) as well as in the Blip and Apmc groups (P<0.05). CI in the Blip and Apmc groups was not significantly altered prior to and after RM. ii) Oxygenation at 0, 1, 2 and 4 h in the 3 groups was improved after RM and the oxygenation indices for the 3 groups at 1 and 2 h were not significantly different (P>0.05). However, the oxygenation index in the Blip group at 4 h was significantly lower than those at 0 h for the Apmc and Bpmc groups (P<0.05). Oxygenation for the Apmc group at 4 h was higher

  8. Iron overload of spleen, liver and kidney as a consequence of hemolytic anaemia.

    PubMed

    Solecki, R; von Zglinicki, T; Müller, H M; Clausing, P

    1983-01-01

    Iron overload in spleen, liver and kidney induced by hemolytic anaemia due to a 90-day oral exposure of rats to diuron (N-3,4-dichlorphenyl-N,N-dimethylurea), an urea herbicide, was studied by histochemistry, transmission electronmicroscopy, morphometry and energy dispersive X-ray microanalysis. Increasing dosages of diuron provoked a hemosiderosis in the spleen followed by erythrocytic sequestration and the formation of haemopoietic foci coinciding with Kupffer cell siderosis of the liver. A strong enlargement of the spleen red pulp on the one hand faces an unchanged total white pulp volume as well as no alterations of the white pulp microscopic structure on the other. The electron dense bodies of the endothelial cells did not contain iron whereas hepatocytes possess two types of lysosomes, homogeneous iron containing ones at the sinusoidal site and complex structured ones without detectable iron at the biliary site. The formation of the homogeneous lysosomes is suggested to be due to the hepatocytic reception of hemoglobin-haptoglobin-complexes after intravascular hemolysis. The lysosomes of the biliary site seem to be engaged in hemoglobin degradation. A partial nephrohydrosis due to hemosiderotic events in succession of intravascular hemolysis including hemoglobin reabsorption from the primary urine could be observed. It is assumed that exocytosis might play a major role in hemosiderin removal from kidney tubule cells. PMID:6683665

  9. Salt-water imbalance and fluid overload in hemodialysis patients: a pivotal role of corin.

    PubMed

    Ricciardi, Carlo Alberto; Lacquaniti, Antonio; Cernaro, Valeria; Bruzzese, Annamaria; Visconti, Luca; Loddo, Saverio; Santoro, Domenico; Buemi, Michele

    2016-08-01

    Natriuretic peptides (NP) play a key role in regulation of salt and water balance. Corin, a serine protease which activates NP, plays a key role in regulation of blood pressure and cardiac function. The aim of the study was to evaluate the involvement of corin in renal physiopathology, analyze its levels in dialyzed patients and evaluate its relation with fluid overload and comorbidities such as heart failure and blood hypertension. We studied serum corin in uremic patients (n = 20) undergoing hemodialysis therapy (HD) and in healthy subjects (HS). Corin levels in uremic patients were higher than in HS (p < 0.0001). Moreover, its concentration did not change after a single HD session. Hypertensive patients and subject suffering from heart failure were characterized by high values of corin. After multivariate analysis, direct correlations were maintained between corin and dialysis vintage (β = 0.83; p = 0.0002), heart failure (β = 0.42; p < 0.0001), systolic blood pressure (β = -0.70; p = 0.0002) and body weight (β = -0.39; p < 0.0001). Corin might be implicated in the regulation of salt and water balance and the disturbances of volume homeostasis of HD patients. However, further studies are warranted to understand the role of corin in kidney diseases and to define its diagnostic and prognostic role. PMID:26206554

  10. ANG II is required for optimal overload-induced skeletal muscle hypertrophy

    NASA Technical Reports Server (NTRS)

    Gordon, S. E.; Davis, B. S.; Carlson, C. J.; Booth, F. W.

    2001-01-01

    ANG II mediates the hypertrophic response of overloaded cardiac muscle, likely via the ANG II type 1 (AT(1)) receptor. To examine the potential role of ANG II in overload-induced skeletal muscle hypertrophy, plantaris and/or soleus muscle overload was produced in female Sprague-Dawley rats (225-250 g) by the bilateral surgical ablation of either the synergistic gastrocnemius muscle (experiment 1) or both the gastrocnemius and plantaris muscles (experiment 2). In experiment 1 (n = 10/group), inhibiting endogenous ANG II production by oral administration of an angiotensin-converting enzyme (ACE) inhibitor during a 28-day overloading protocol attenuated plantaris and soleus muscle hypertrophy by 57 and 96%, respectively (as measured by total muscle protein content). ACE inhibition had no effect on nonoverloaded (sham-operated) muscles. With the use of new animals (experiment 2; n = 8/group), locally perfusing overloaded soleus muscles with exogenous ANG II (via osmotic pump) rescued the lost hypertrophic response in ACE-inhibited animals by 71%. Furthermore, orally administering an AT(1) receptor antagonist instead of an ACE inhibitor produced a 48% attenuation of overload-induced hypertrophy that could not be rescued by ANG II perfusion. Thus ANG II may be necessary for optimal overload-induced skeletal muscle hypertrophy, acting at least in part via an AT(1) receptor-dependent pathway.

  11. Mycobacterium avium Complex Infection in a Patient with Sickle Cell Disease and Severe Iron Overload

    PubMed Central

    Jafferjee, Nasima; Thomas, David; Jacobs, Gretta; Meyerson, Howard J.

    2014-01-01

    A 34-year-old female with sickle cell anemia (hemoglobin SS disease) and severe iron overload presented to our institution with the subacute presentation of recurrent pain crisis, fever of unknown origin, pancytopenia, and weight loss. A CT scan demonstrated both lung and liver nodules concerning for granulomatous disease. Subsequent biopsies of the liver and bone marrow confirmed the presence of noncaseating granulomas and blood cultures isolated Mycobacterium avium complex MAC. Disseminated MAC is considered an opportunistic infection typically diagnosed in the immunocompromised and rarely in immunocompetent patients. An appreciable number of mycobacterial infection cases have been reported in sickle cell disease patients without immune dysfunction. It has been reported that iron overload is known to increase the risk for mycobacterial infection in vitro and in vivo studies. While iron overload is primarily known to cause end organ dysfunction, the clinical relationship with sickle cell disease and disseminated MAC infection has not been reported. Clinical iron overload is a common condition diagnosed in the sub-Saharan African population. High dietary iron, genetic defects in iron trafficking, as well as hemoglobinopathy are believed to be the etiologies for iron overload in this region. Patients with iron overload in this region were 17-fold more likely to die from Mycobacterium tuberculosis. Both experimental and clinical evidence suggest a possible link to iron overload and mycobacterial infections; however larger observational studies are necessary to determine true causality. PMID:25544913

  12. Hemodynamic and radionuclide effects of acute captopril therapy for heart failure: changes in left and right ventricular volumes and function at rest and during exercise

    SciTech Connect

    Massie, B.; Kramer, B.L.; Topic, N.; Henderson, S.G.

    1982-06-01

    Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responses at rest were decreases in left and right ventricular end-diastolic volumes from 388 + 81 to 350 + 77 ml (p < 0.01) and from 52 + 26 to 43 + 20 volume units (p < 0.01), respectively, and in their corresponding filling pressures, from 24 + 10 to 17 + 9 mm Hg and 10 + 5 to and + 5 mm Hg (both p < 0.01). Altough stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 + 6% to 22 + 5% and from 25 + 9% to 29 + 11%, respectively (both p < 0.01). During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. Thus, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.

  13. Hemodynamic and radionuclide effects of acute captopril therapy for heart failure: changes in left and right ventricular volumes and function at rest and during exercise

    SciTech Connect

    Massie, B.; Kramer, B.L.; Topic, N.; Henderson, S.G.

    1982-06-01

    Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responses at rest were decreases in left and right ventricular end-diastolic volumes from 388 +/- 81 to 350 +/- 77 ml and from 52 +/- 26 to 43 +/- 20 volume units, respectively, and in their corresponding filling pressures, from 24 +/- 10 to 17 +/- 9 mm Hg and 10 +/- 5 to 6 +/- 5 mm Hg. Although stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 +/- 6% to 22+/- 5% and from 25 +/- 9% to 29 +/- 11%, respectively. During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. This, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.

  14. Static and dynamic responses of carotid sinus baroreceptors in dogs with chronic volume overload.

    PubMed Central

    Niebauer, M; Zucker, I H

    1985-01-01

    In this study we determined if there are any alterations in carotid sinus baroreceptor discharge in a model of heart failure in the dog. The left carotid sinus was isolated and perfused at 100 mmHg with a modified Krebs-Henseleit solution. Two groups of dogs were used: a normal group and a group with a chronic aorto-caval fistula (a.v.f.) of up to 20 weeks duration. The a.v.f. group had a significantly elevated heart rate and left ventricular end diastolic pressure as well as an increased arterial pulse pressure compared to normals. However, mean arterial pressure measured in the aortic arch was not significantly different. Carotid sinus pressure-discharge curves were constructed during increases in carotid sinus pressure by steps and by ramps of pressure change up to 200 mmHg/s. Carotid sinus diameter was also measured using sonomicrometer crystals. In six dogs from each group the sodium, potassium and water content of the right carotid sinus was measured. Several parameters of second order polynomial curves that were fitted to the data were compared between the two groups for step and ramp increases in pressure. These included maximum baroreceptor gain, threshold pressure and plateau pressure. Baroreceptor gain was significantly lower in the a.v.f. group for the step and lowest ramp rate pressure changes. Threshold pressure was significantly higher for the a.v.f. group for steps and the three slowest ramp rates. Plateau pressures were significantly higher for the steps and lowest ramp rate. The carotid sinus strain that was produced at any given carotid sinus pressure was not significantly different between the two groups. In addition, there was no difference in the sodium, potassium or water content of the carotid sinus between the two groups. It was concluded that there is a depression of the static discharge characteristics in this model of heart failure which is not due to an alteration in electrolyte or water content or to the compliance of the carotid sinus. PMID:4093885

  15. The effect of K201 on isolated working rabbit heart mechanical function during pharmacologically induced Ca2+ overload

    PubMed Central

    Kelly, A; Elliott, EB; Matsuda, R; Kaneko, N; Smith, GL; Loughrey, CM

    2012-01-01

    BACKGROUND AND PURPOSE Reduced cardiac contractility has been associated with disrupted myocardial Ca2+ signalling. The 1,4 benzothiazepine K201 (JTV-519) acts on several Ca2+ handling proteins and improves cardiac contractility in vivo in a variety of animal models of myocardial dysfunction. However, it is unclear whether this improvement depends on the systemic effects of K201 or if K201 reverses the effects of Ca2+ dysregulation, regardless of the cause. EXPERIMENTAL APPROACH The effect of K201 on cardiac mechanical function was assessed in isolated working hearts from adult rabbits, using a ventricular pressure-volume catheter. In separate experiments, the effect of K201 was investigated in hearts following pharmacologically induced Ca2+ overload using elevated extracellular [Ca2+] ([Ca2+]o) and β-adrenoceptor stimulation. KEY RESULTS K201 induced a concentration-dependent decline in systolic function (peak pressure, dP/dtmax and preload recruitable stroke work), lusitropy (reduced dP/dtmin and increased end diastolic pressure) and stroke volume, independent of decreased heart rate. In separate experiments, mechanical function in hearts exposed to 4.5 mmol·L−1[Ca2+]o and 150 nmol·L−1 isoprenaline declined until cessation of aortic flow (in 6 out of 11 hearts). However, all hearts perfused with the addition of 1 µmol·L−1 K201 maintained aortic flow and demonstrated significantly improved peak systolic pressures, dP/dtmax and dP/dtmin. CONCLUSIONS AND IMPLICATIONS K201 significantly improved mechanical function of the heart during Ca2+ overload. This suggests that K201 can limit the detrimental effects of elevated intracellular Ca2+ and exert beneficial effects on cardiac contractile function, independent of systemic effects previously observed in vivo. PMID:21658026

  16. Efferent Pathways in Sodium Overload-Induced Renal Vasodilation in Rats

    PubMed Central

    Amaral, Nathalia O.; de Oliveira, Thiago S.; Naves, Lara M.; Filgueira, Fernando P.; Ferreira-Neto, Marcos L.; Schoorlemmer, Gerard H. M.; de Castro, Carlos H.; Freiria-Oliveira, André H.; Xavier, Carlos H.; Colugnati, Diego B.; Rosa, Daniel A.; Blanch, Graziela T.; Borges, Clayton L.; Soares, Célia M. A.; Reis, Angela A. S.; Cravo, Sergio L.; Pedrino, Gustavo R.

    2014-01-01

    Hypernatremia stimulates the secretion of oxytocin (OT), but the physiological role of OT remains unclear. The present study sought to determine the involvement of OT and renal nerves in the renal responses to an intravenous infusion of hypertonic saline. Male Wistar rats (280–350 g) were anesthetized with sodium thiopental (40 mg. kg−1, i.v.). A bladder cannula was implanted for collection of urine. Animals were also instrumented for measurement of mean arterial pressure (MAP) and renal blood flow (RBF). Renal vascular conductance (RVC) was calculated as the ratio of RBF by MAP. In anesthetized rats (n = 6), OT infusion (0.03 µg • kg−1, i.v.) induced renal vasodilation. Consistent with this result, ex vivo experiments demonstrated that OT caused renal artery relaxation. Blockade of OT receptors (OXTR) reduced these responses to OT, indicating a direct effect of this peptide on OXTR on this artery. Hypertonic saline (3 M NaCl, 1.8 ml • kg−1 b.wt., i.v.) was infused over 60 s. In sham rats (n = 6), hypertonic saline induced renal vasodilation. The OXTR antagonist (AT; atosiban, 40 µg • kg−1 • h−1, i.v.; n = 7) and renal denervation (RX) reduced the renal vasodilation induced by hypernatremia. The combination of atosiban and renal denervation (RX+AT; n = 7) completely abolished the renal vasodilation induced by sodium overload. Intact rats excreted 51% of the injected sodium within 90 min. Natriuresis was slightly blunted by atosiban and renal denervation (42% and 39% of load, respectively), whereas atosiban with renal denervation reduced sodium excretion to 16% of the load. These results suggest that OT and renal nerves are involved in renal vasodilation and natriuresis induced by acute plasma hypernatremia. PMID:25279805

  17. Efferent pathways in sodium overload-induced renal vasodilation in rats.

    PubMed

    Amaral, Nathalia O; de Oliveira, Thiago S; Naves, Lara M; Filgueira, Fernando P; Ferreira-Neto, Marcos L; Schoorlemmer, Gerard H M; de Castro, Carlos H; Freiria-Oliveira, André H; Xavier, Carlos H; Colugnati, Diego B; Rosa, Daniel A; Blanch, Graziela T; Borges, Clayton L; Soares, Célia M A; Reis, Angela A S; Cravo, Sergio L; Pedrino, Gustavo R

    2014-01-01

    Hypernatremia stimulates the secretion of oxytocin (OT), but the physiological role of OT remains unclear. The present study sought to determine the involvement of OT and renal nerves in the renal responses to an intravenous infusion of hypertonic saline. Male Wistar rats (280-350 g) were anesthetized with sodium thiopental (40 mg. kg(-1), i.v.). A bladder cannula was implanted for collection of urine. Animals were also instrumented for measurement of mean arterial pressure (MAP) and renal blood flow (RBF). Renal vascular conductance (RVC) was calculated as the ratio of RBF by MAP. In anesthetized rats (n = 6), OT infusion (0.03 µg • kg(-1), i.v.) induced renal vasodilation. Consistent with this result, ex vivo experiments demonstrated that OT caused renal artery relaxation. Blockade of OT receptors (OXTR) reduced these responses to OT, indicating a direct effect of this peptide on OXTR on this artery. Hypertonic saline (3 M NaCl, 1.8 ml • kg(-1) b.wt., i.v.) was infused over 60 s. In sham rats (n = 6), hypertonic saline induced renal vasodilation. The OXTR antagonist (AT; atosiban, 40 µg • kg(-1) • h(-1), i.v.; n = 7) and renal denervation (RX) reduced the renal vasodilation induced by hypernatremia. The combination of atosiban and renal denervation (RX+AT; n = 7) completely abolished the renal vasodilation induced by sodium overload. Intact rats excreted 51% of the injected sodium within 90 min. Natriuresis was slightly blunted by atosiban and renal denervation (42% and 39% of load, respectively), whereas atosiban with renal denervation reduced sodium excretion to 16% of the load. These results suggest that OT and renal nerves are involved in renal vasodilation and natriuresis induced by acute plasma hypernatremia. PMID:25279805

  18. Entry overload, emergency department overcrowding, and ambulance bypass

    PubMed Central

    Fatovich, D; Hirsch, R

    2003-01-01

    Objectives: To describe an experience of emergency department (ED) overcrowding and ambulance bypass. Methods: A prospective observational study at Royal Perth Hospital, a major teaching hospital. Episodes of ambulance bypass and their characteristics were recorded. Results: From 1 July 1999 to 30 June 2001, there were 141 episodes of ambulance bypass (mean duration 187 min, range 35–995). Monday was the most common day with 39 (28%) episodes. Entry block alone was the most common reason bypass was activated (n=38, 30.4%). The mean number of patients in ED at these times was 40 (occupancy 174%), including nine in the corridor, seven awaiting admission, and 14 waiting to be seen. Episodes attributable to entry block were typically preceded by a presentation rate of ⩾10 patients per hour for ⩾2 hours (OR 6.2, 95% CI 4.3 to 8.5). Mid-afternoon to early evening was the most common time for activation. Ambulance bypass is increasing in frequency and duration. Conclusions: Entry overload resulting in entry block results from overwhelming numbers of patients presenting to the ED in a short space of time. Entry block impairs access to emergency care. Unless something is done in the near future, the general public may no longer be able to rely on EDs for quality and timely emergency care. A "whole of system" approach is necessary to tackle the problem. PMID:12954675

  19. Altered carnitine transport in pressure-overload hypertrophied rat hearts

    SciTech Connect

    O'Rourke, B.; Foster, K.; Reibel, D.K.

    1986-03-01

    The authors have previously observed reduced carnitine levels in hypertrophied hearts of rats subjected to aortic constriction. In an attempt to determine the mechanism for reduced myocardial carnitine content, carnitine transport was examined in isolated perfused hearts. Hearts were excised from sham-operated and aortic-constricted rats 3 weeks following surgery and perfused at 60 mm Hg aortic pressure with buffer containing various concentrations of L-/sup 14/C-carnitine. Carnitine uptake by control and hypertrophied hearts was linear throughout 30 minutes of perfusion with 40 ..mu..M carnitine. Total carnitine uptake was significantly reduced by 25% in hypertrophied hearts at each time point examined. The reduction in uptake by hypertrophied hearts was also evident when hearts were perfused with 100 or 200 ..mu..M carnitine. When 0.05 mM mersalyl acid was included in the buffer to inhibit the carrier-mediated component of transport, no difference in carnitine uptake was observed indicating that the transport of carnitine by diffusion was unaltered in the hypertrophied myocardium. Carrier-mediated carnitine uptake (total uptake - uptake by diffusion) was significantly reduced by approximately 40% in hypertrophied hearts at all concentrations examined. Thus, the reduction in carnitine content in the pressure-overload hypertrophied rat heart appears to be due to a reduction in carrier-mediated carnitine uptake by the heart.

  20. Overload and neovascularization of shoulder tendons in volleyball players

    PubMed Central

    2012-01-01

    Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746

  1. Game-Theoretic Models of Information Overload in Social Networks

    NASA Astrophysics Data System (ADS)

    Borgs, Christian; Chayes, Jennifer; Karrer, Brian; Meeder, Brendan; Ravi, R.; Reagans, Ray; Sayedi, Amin

    We study the effect of information overload on user engagement in an asymmetric social network like Twitter. We introduce simple game-theoretic models that capture rate competition between celebrities producing updates in such networks where users non-strategically choose a subset of celebrities to follow based on the utility derived from high quality updates as well as disutility derived from having to wade through too many updates. Our two variants model the two behaviors of users dropping some potential connections (followership model) or leaving the network altogether (engagement model). We show that under a simple formulation of celebrity rate competition, there is no pure strategy Nash equilibrium under the first model. We then identify special cases in both models when pure rate equilibria exist for the celebrities: For the followership model, we show existence of a pure rate equilibrium when there is a global ranking of the celebrities in terms of the quality of their updates to users. This result also generalizes to the case when there is a partial order consistent with all the linear orders of the celebrities based on their qualities to the users. Furthermore, these equilibria can be computed in polynomial time. For the engagement model, pure rate equilibria exist when all users are interested in the same number of celebrities, or when they are interested in at most two. Finally, we also give a finite though inefficient procedure to determine if pure equilibria exist in the general case of the followership model.

  2. Semicircular Canals Circumvent Brownian Motion Overload of Mechanoreceptor Hair Cells

    PubMed Central

    Muller, Mees; Heeck, Kier

    2016-01-01

    Vertebrate semicircular canals (SCC) first appeared in the vertebrates (i.e. ancestral fish) over 600 million years ago. In SCC the principal mechanoreceptors are hair cells, which as compared to cochlear hair cells are distinctly longer (70 vs. 7 μm), 10 times more compliant to bending (44 vs. 500 nN/m), and have a 100-fold higher tip displacement threshold (< 10 μm vs. <400 nm). We have developed biomechanical models of vertebrate hair cells where the bundle is approximated as a stiff, cylindrical elastic rod subject to friction and thermal agitation. Our models suggest that the above differences aid SCC hair cells in circumventing the masking effects of Brownian motion noise of about 70 nm, and thereby permit transduction of very low frequency (<10 Hz) signals. We observe that very low frequency mechanoreception requires increased stimulus amplitude, and argue that this is adaptive to circumvent Brownian motion overload at the hair bundles. We suggest that the selective advantage of detecting such low frequency stimuli may have favoured the evolution of large guiding structures such as semicircular canals and otoliths to overcome Brownian Motion noise at the level of the mechanoreceptors of the SCC. PMID:27448330

  3. Ignition Limit of Overloaded Electric Wire in Microgravity

    NASA Astrophysics Data System (ADS)

    Takano, Y.; Fujita, O.; Ito, H.; Nakamura, Y.

    2012-01-01

    Ignition phenomena of overloaded electric wire have been investigated in microgravity as basic information for fire safety in space. Microgravity experiments were conducted at MGLAB (Micro Gravity Laboratory of Japan) to provide 4.5 s of microgravity duration. Numerical calculation with the model of one dimensional cylindrical coordinate is also carried out. In this study the current supply duration, the surrounding oxygen concentration and the supplied electric current value was selected as the main test parameters. The results showed that the LOI; limiting oxygen index, the lowest oxygen concentration at which ignition can occur, estimated by numerical calculation showed similar dependency on applied electric energy as the experiments, LOI becomes smaller with increase in electric energy supply. One of the factors to determine the LOI is thickness of fuel layer as a result of degradation gas release from the molten insulation. Thin fuel layer results in rapid decrease in released gas temperature because ambient room-temperature atmosphere is easily transported to wire surface. In this situation, to occur the ignition, it needs higher oxygen concentration to increase reaction rate and, therefore, LOI becomes higher value when the amount of released gas decrease.

  4. Cognitive overload and communication in two healthcare settings.

    PubMed

    Cicourel, Aaron V

    2004-01-01

    The confluence of organizational social interaction and cognitive information processing constraints create 'noisy' conditions in institutionalized settings. Attentional and memory limitations always influence the ability of participants to comprehend each other's communication. Two organizational settings (a medical specialty clinic and periodontal office) will be used to explore a few features of healthcare delivery that are often ignored in studies of such systems. Scheduling appointments, for example, creates stress for both patients and healthcare personnel but is often an unexamined aspect of healthcare delivery that has become both challenging and often irritating for all concerned. For example, when patients call, someone at a general scheduling center or the particular clinic or office of an individual physician or dentist or a group practice will answer the call with a menu of options, or the caller may be asked to leave message. When a patient leaves a clinic or surgery office after a visit, they may be allowed to make a new appointment. The term 'cognitive overload' is a ubiquitous element of all healthcare systems and refers to organizationally induced and constrained limited capacity processing inherent in the way improvised discourse practices, and annotative devices or artifacts (such as written notes or some related strategy) become an integral part of everyday healthcare delivery. PMID:16808687

  5. Key microbial communities steering the functioning of anaerobic digesters during hydraulic and organic overloading shocks.

    PubMed

    Regueiro, Leticia; Lema, Juan M; Carballa, Marta

    2015-12-01

    Overloading is one of the most typical process disturbance in anaerobic digesters, resulting in volatile fatty acids (VFAs) accumulation. This work aimed to study the microbial community dynamics during hydraulic (decreasing the hydraulic retention time (HRT)) and organic (increasing the organic loading rate maintaining the HRT constant) overload shocks in anaerobic reactors treating agro-industrial wastes, as well as during the recovery period. In both cases, the organic loading rate increased from 2 to 10gCODL(-1)d(-1), resulting in VFAs accumulation up to 9gL(-1). Both overloads were correlated to an increase in Bacteroidetes and Actinobacteria phyla and with a drop in Syntrophomonadaceae and Pseudomonadaceae families. In contrast, Tissierellaceae family only increased during the organic shock. Active Archaea decreased in both overloads, going from Methanosaeta dominance to Methanosarcina prevalence. During the recovery period, Porphyromonadaceae family increased its presence and Clostridium genus recovered values prior to perturbation. PMID:26340029

  6. Fatigue crack growth behavior and overload effect of AISI 304 stainless steel in different atmospheres

    NASA Astrophysics Data System (ADS)

    Kelestemur, Mehmet Halidun

    1998-12-01

    AISI 304 stainless steel shows strain induced martensitic transformation at the crack tip. Such transformation may have effects on crack closure during fatigue crack propagation. Due to importance of AISI 304 in structural applications, the fatigue crack propagation and martensitic transformation in this material have to be investigated thoroughly. Fatigue crack growth behavior, overload retardation and characterization of martensitic transformation at the crack tip upon fatigue loading were investigated in 304 stainless steel at three different atmospheres, namely dry argon, moist air (75% relative humidity) and hydrogen. Comparison in various atmospheres showed that moist air did not influence that fatigue crack growth rate. However, in hydrogen atmosphere the material did not show threshold behavior and the crack growth rate was considerably higher. It was found that roughness-induced crack closure was the primary mechanism in the threshold region. Fractographic pictures taken by SEM and direct observation of crack profile showed that crack deflection and branching occurred during the fatigue crack propagation and plasticity-induced crack closure was not the primary closure mechanism. The influence of fatigue crack propagation on the rate and size of martensitic transformation at the crack tip was investigated. The overload retardation of the material was lower at hydrogen atmosphere. This low degree of retardation was explained by hydrogen embrittlement mechanism. Fractographic observations show striations at the overload zone in argon atmosphere indicating ductile fracture. In hydrogen atmosphere, overload area shows secondary cracks which represent brittle fracture. Crack closure measurements and modified Paris law did not show evidence for different retardation mechanisms at different atmospheres. It is found that primary retardation mechanisms were crack deflection, crack blunting and roughness-induced crack closure after application of overload(s). An

  7. Modelling training response in elite female gymnasts and optimal strategies of overload training and taper.

    PubMed

    Sanchez, Anthony M J; Galbès, Olivier; Fabre-Guery, Frédérique; Thomas, Luc; Douillard, Aymeric; Py, Guillaume; Busso, Thierry; Candau, Robin B

    2013-01-01

    The aim of the study is the modelling of training responses with a variable dose-response model in a sport discipline that requires highly complex coordination. We propose a method to optimise the training programme plan using the potential maximal performance gain associated with overload and tapering periods. Data from five female elite gymnasts were collected over a 3-month training period. The relationship between training amounts and performance was then assessed with a non-linear model. The optimal magnitude of training load reduction and its duration were investigated with and without an overload period using simulation procedures based on individual responses to training. The correlation between actual and modelled performances was significant (R² = 0.81 ± 0.02, P < 0.01). The standard error was 2.7%. Simulations revealed that taper preceded by an overload period allows a higher performance to be achieved compared to an absence of overload period (106.3 ± 0.3% vs. 105.1 ± 0.3%). With respect to the pre-taper load, the model predicts that optimal load reductions during taper were 48.4 ± 0.7% and 42.5 ± 1.0% for overloading and non-overloading strategies, respectively. Moreover, optimal durations of the taper period were 34 ± 0.5 days and 22 ± 0.5 days for overloading and non-overloading strategies, respectively. In conclusion, the study showed that the variable dose-response model describes precisely the training response in gymnasts. PMID:23656356

  8. Functional Overloading of Dystrophic Mice Enhances Muscle-Derived Stem Cell Contribution to Muscle Contractile Capacity

    PubMed Central

    Ambrosio, Fabrisia; Ferrari, Ricardo J.; Fitzgerald, G. Kelley; Carvell, George; Boninger, Michael L.; Huard, Johnny

    2016-01-01

    Objectives To evaluate the effect of functional overloading on the transplantation of muscle derived stem cells (MDSCs) into dystrophic muscle and the ability of transplanted cells to increase dystrophic muscle’s ability to resist overloading-induced weakness. Design Cross-sectional. Setting Laboratory. Animals Male mice (N=10) with a dystrophin gene mutation. Interventions MDSCs were intramuscularly transplanted into the extensor digitorum longus muscle (EDL). Functional overloading of the EDL was performed by surgical ablation of the EDL’s synergist. Main Outcome Measures The total number of dystrophin-positive fibers/cross-section (as a measure of stem cell engraftment), the average number of CD31+ cells (as a measure of capillarity), and in vitro EDL contractile strength. Independent t tests were used to investigate the effect of overloading on engraftment, capillarity, and strength. Paired t tests were used to investigate the effect of MDSC engraftment on strength and capillarity. Results MDSC transplantation protects dystrophic muscles against overloading-induced weakness (specific twitch force: control 4.5N/cm2±2.3; MDSC treated 7.9N/cm2±1.4) (P=.02). This improved force production following overloading is concomitant with an increased regeneration by transplanted MDSCs (MDSC: 26.6±20.2 dystrophin-positive fibers/cross-section; overloading + MDSC: 170.6±130.9 dystrophin-positive fibers/cross-section [P=.03]). Overloading-induced increases in skeletal muscle capillarity is significantly correlated with increased MDSC engraftment (R2=.80, P=.01). Conclusions These findings suggest that the functional contribution of transplanted MDSCs may rely on activity-dependent mechanisms, possibly mediated by skeletal muscle vascularity. Rehabilitation modalities may play an important role in the development of stem cell transplantation strategies for the treatment of muscular dystrophy. PMID:19154831

  9. Iron overload in non-transfusion-dependent thalassemia: association with genotype and clinical risk factors.

    PubMed

    Tantiworawit, Adisak; Charoenkwan, Pimlak; Hantrakool, Sasinee; Choeyprasert, Worawut; Sivasomboon, Chate; Sanguansermsri, Torpong

    2016-06-01

    In the present study, we sought to determine the prevalence of iron overload in patients with non-transfusion-dependent thalassemia (NTDT) and its association with genotype and other clinical risk factors, and to evaluate the correlation between serum ferritin (SF) and liver iron concentration (LIC). Myocardial and liver iron concentration was measured by MRI using a T2* gradient multi-echo sequence in NTDT patients, aged 10-50 years. Of 91 patients, 54 (59 %) had hepatic iron overload. None had cardiac iron overload. The clinical risk factors for hepatic iron overload were age >20 years (adjusted OR 30.2, 95 % CI 4.5-203, p < 0.001), hemoglobin level <7 g/dL (adjusted OR 6.3, 95 % CI 1.01-39.5, p = 0.049), and cumulative RBC transfusion >10 units (adjusted OR 53.6, 95 % CI 3.2-884, p = 0.005). Beta-thalassemia genotype was associated with higher risk of iron overload by univariate analysis, but the association was not significant when adjusted for other clinical factors. The correlation coefficient between SF and LIC was 0.60 (p < 0.001). In conclusion, the prevalence of hepatic iron overload is high in NTDT. Older age, lower hemoglobin level, and higher cumulative RBC transfusion are significant risk factors. SF and LIC show a significant positive correlation. PMID:27052211

  10. Secoisolariciresinol Diglucoside Abrogates Oxidative Stress-Induced Damage in Cardiac Iron Overload Condition

    PubMed Central

    Puukila, Stephanie; Bryan, Sean; Laakso, Anna; Abdel-Malak, Jessica; Gurney, Carli; Agostino, Adrian; Belló-Klein, Adriane; Prasad, Kailash; Khaper, Neelam

    2015-01-01

    Cardiac iron overload is directly associated with cardiac dysfunction and can ultimately lead to heart failure. This study examined the effect of secoisolariciresinol diglucoside (SDG), a component of flaxseed, on iron overload induced cardiac damage by evaluating oxidative stress, inflammation and apoptosis in H9c2 cardiomyocytes. Cells were incubated with 50 μ5M iron for 24 hours and/or a 24 hour pre-treatment of 500 μ M SDG. Cardiac iron overload resulted in increased oxidative stress and gene expression of the inflammatory mediators tumor necrosis factor-α, interleukin-10 and interferon γ, as well as matrix metalloproteinases-2 and -9. Increased apoptosis was evident by increased active caspase 3/7 activity and increased protein expression of Forkhead box O3a, caspase 3 and Bax. Cardiac iron overload also resulted in increased protein expression of p70S6 Kinase 1 and decreased expression of AMP-activated protein kinase. Pre-treatment with SDG abrogated the iron-induced increases in oxidative stress, inflammation and apoptosis, as well as the increased p70S6 Kinase 1 and decreased AMP-activated protein kinase expression. The decrease in superoxide dismutase activity by iron treatment was prevented by pre-treatment with SDG in the presence of iron. Based on these findings we conclude that SDG was cytoprotective in an in vitro model of iron overload induced redox-inflammatory damage, suggesting a novel potential role for SDG in cardiac iron overload. PMID:25822525

  11. Pharmacokinetics study of Zr-89-labeled melanin nanoparticle in iron-overload mice.

    PubMed

    Zhang, Pengjun; Yue, Yuanyuan; Pan, Donghui; Yang, Runlin; Xu, Yuping; Wang, Lizhen; Yan, Junjie; Li, Xiaotian; Yang, Min

    2016-09-01

    Melanin, a natural biological pigment present in many organisms, has been found to exhibit multiple functions. An important property of melanin is its ability to chelate metal ions strongly, which might be developed as an iron chelator for iron overload therapy. Herein, we prepared the ultrasmall water-soluble melanin nanoparticle (MP) and firstly evaluate the pharmacokinetics of MP in iron-overload mice to provide scientific basis for treating iron-overload. To study the circulation time and biodistribution, MP was labeled with (89)Zr, a long half-life (78.4h) positron-emitting metal which is suited for the labeling of nanoparticles and large bioactive molecule. MP was chelated with (89)Zr directly at pH5, resulting in non-decay-corrected yield of 89.6% and a radiochemical purity of more than 98%. The specific activity was at least190 MBq/μmol. The (89)Zr-MP was stable in human plasma and PBS for at least 48h. The half-life of (89)Zr-MP was about 15.70±1.74h in iron-overload mice. Biodistribution studies and MicroPET imaging showed that (89)Zr-MP mainly accumulated in liver and spleen, which are the target organ of iron-overload. The results indicate that the melanin nanoparticle is promising for further iron overload therapy. PMID:27359110

  12. Production of amines in equine cecal contents in an in vitro model of carbohydrate overload.

    PubMed

    Bailey, S R; Rycroft, A; Elliott, J

    2002-10-01

    Acute laminitis can be induced experimentally in horses by the administration of carbohydrate, resulting in fermentation within the cecum and ischemia-reperfusion of the digits. The products of fermentation that trigger acute laminitis are as yet unknown; however, compounds such as amines might play a role due to their potential vasoactive properties. The objectives of this study were to quantify the amines present in equine cecal contents and to use a model of carbohydrate overload in vitro to test the hypothesis that carbohydrate fermentation is associated with increased amine production. Cecal contents from each horse were divided into aliquots and incubated anaerobically with either cornstarch or inulin (a form of fructan carbohydrate; both 1 g/100 mL). The pH was measured and samples were taken at the same time for amine measurement by HPLC at 2-h intervals over a 24-h period. In a second set of experiments, the effects of the antibiotic virginiamycin (1 mg/100 mL), calcium (CaPO4; 0.3 g/100 mL), and plant steroidal saponin (Yucca schidigera extract; 0.1 g/100 mL) were examined on pH and amine concentrations in cecal contents incubated with starch or inulin. Both starch and inulin caused significant time-dependent falls in pH, from 6.7 +/- 0.1 at 0 h to 5.2 +/- 0.1 (starch) and 5.0 +/- 0.1 (inulin) at 24 h. Fermentation of carbohydrate was also associated with increased production of phenylethylamine and isoamylamine (two- to threefold increases) as well as putrescine and cadaverine (1.5- to twofold increases). Virginiamycin inhibited the fall in pH and increases in production of phenylethylamine and isoamylamine, while calcium phosphate moderated the changes in pH only. Yucca schidigera extract was without effect. These data show that fermentation of carbohydrate by equine cecal microbiota may lead to increased production of amines. PMID:12413088

  13. Acute Bronchitis

    MedlinePlus

    ... or though physical contact (for example, on unwashed hands). Being exposed to tobacco smoke, air pollution, dusts, vapors, and fumes can also cause acute bronchitis. Less often, bacteria can also cause acute bronchitis. To diagnose acute ...

  14. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute; Acute bladder infection; Acute bacterial cystitis ... control. Menopause also increases the risk for a urinary tract infection. The following also increase your chances of having ...

  15. Damage in total knee replacements from mechanical overload.

    PubMed

    Zimmerman, William F; Miller, Mark A; Cleary, Richard J; Izant, Timothy H; Mann, Kenneth A

    2016-07-01

    The mechanical loads acting across the knee joint following total knee replacements (TKR) during activities of daily living have recently been measured using instrumented TKRs. Using a series of postmortem retrieved TKR constructs we investigated whether these mechanical loads could result in damage to the implant bone interface or supporting bone in the tibia. Eighteen cemented en bloc tibial components (0 to 22 years in service) were loaded under axial compression in increments from 1 to 10 times body weight and digital image correlation was used to measure bone strain and interface micromotion during loading and unloading. Failure was considered to occur when micromotion exceeded 150µm or compressive bone strain exceeded 7300με. The results show that all retrieved specimens had sufficient bone strength to support most activities of daily living, but ~40% would be at risk under larger physiologic loads that might occur secondary to a higher impacts such as jogging or a stumble. The tray-bone micromotion (regression model R(2)=0.48, p=0.025) was greater for donors with lower age at implantation (p=0.0092). Proximal bone strain (model R(2)=0.46, p=0.03) was greater for donors with longer time in service (p=0.021). Distal bone strain (model R(2)=0.58, p=0.005) was greater for donors with more time in service (p=0.0054) and lower peri-implant BMD (p=0.049). High mechanical overload of a single or repetitive nature may be an initiating factor in aseptic loosening of total joint arthroplasties and should be avoided in order to prolong the life of the implant. PMID:27237382

  16. Cinnamaldehyde attenuates pressure overload-induced cardiac hypertrophy

    PubMed Central

    Yang, Liu; Wu, Qing-Qing; Liu, Yuan; Hu, Zhe-Fu; Bian, Zhou-Yan; Tang, Qi-Zhu

    2015-01-01

    Background: Cinnamaldehyde is a major bioactive compound isolated from the leaves of Cinnamomum osmophloeum. Studies have demonstrated that cinnamaldehyde has anti-bacterial activity, anti-tumorigenic effect, immunomodulatory effect, anti-fungal activity, anti-oxidative effect, anti-inflammatory and anti-diabetic effect. It has been proven that Cinnamaldehyde improves ischemia/reperfusion injury of pre-treatment. However, little is known about the effect of cinnamaldehyde on cardiac hypertrophy. Methods: Aortic banding (AB) was performed to induce cardiac hypertrophy in mice. Cinnamaldehyde premixed in diets was administered to mice after one week of AB. Echocardiography and catheter-based measurements of hemodynamic parameters were performed at week 7 after starting cinnamaldehyde (8 weeks after surgery). The extent of cardiac hypertrophy was evaluated by pathological and molecular analyses of heart samples. Meanwhile, the effect of cinnamaldehyde on myocardial hypertrophy, fibrosis and dysfunction induced by AB was investigated, as was assessed by heart weigh/body weight, lung weight/body weight, heart weight/tibia length, echocardiographic and haemodynamic parameters, histological analysis, and gene expression of hypertrophic and fibrotic markers. Results: Our data demonstrated that echocardiography and catheter-based measurements of hemodynamic parameters at week 7 revealed the amelioration of systolic and diastolic abnormalities by cinnamaldehyde intervention. Cardiac fibrosis in AB mice was also decreased by cinnamaldehyde. Moreover, the beneficial effect of cinnamaldehyde was associated with the normalization in gene expression of hypertrophic and fibrotic markers. Further studies showed that pressure overload significantly induced the activation of extracellular signal-regulated kinase (ERK) signaling pathway, which was blocked by cinnamaldehyde. Conclusion: Cinnamaldehyde may be able to retard the progression of cardiac hypertrophy and fibrosis, probably

  17. Electrical short circuit and current overload tests on aircraft wiring

    NASA Technical Reports Server (NTRS)

    Cahill, Patricia

    1995-01-01

    The findings of electrical short circuit and current overload tests performed on commercial aircraft wiring are presented. A series of bench-scale tests were conducted to evaluate circuit breaker response to overcurrent and to determine if the wire showed any visible signs of thermal degradation due to overcurrent. Three types of wire used in commercial aircraft were evaluated: MIL-W-22759/34 (150 C rated), MIL-W-81381/12 (200 C rated), and BMS 1360 (260 C rated). A second series of tests evaluated circuit breaker response to short circuits and ticking faults. These tests were also meant to determine if the three test wires behaved differently under these conditions and if a short circuit or ticking fault could start a fire. It is concluded that circuit breakers provided reliable overcurrent protection. Circuit breakers may not protect wire from ticking faults but can protect wire from direct shorts. These tests indicated that the appearance of a wire subjected to a current that totally degrades the insulation looks identical to a wire subjected to a fire; however the 'fire exposed' conductor was more brittle than the conductor degraded by overcurrent. Preliminary testing indicates that direct short circuits are not likely to start a fire. Preliminary testing indicated that direct short circuits do not erode insulation and conductor to the extent that ticking faults did. Circuit breakers may not safeguard against the ignition of flammable materials by ticking faults. The flammability of materials near ticking faults is far more important than the rating of the wire insulation material.

  18. The thrower's elbow: arthroscopic treatment of valgus extension overload syndrome.

    PubMed

    O'Holleran, James D; Altchek, David W

    2006-02-01

    Injury to the medial collateral ligament of the elbow (MCL) can be a career-threatening injury for an overhead athlete without appropriate diagnosis and treatment. It has been considered separately from other athletic injuries due to the unique constellation of pathology that results from repetitive overhead throwing. The past decade has witnessed tremendous gains in understanding of the complex interplay between the dynamic and static stabilizers of the athlete's elbow. Likewise, the necessity to treat these problems in a minimally invasive manner has driven the development of sophisticated techniques and instrumentation for elbow arthroscopy. MCL injuries, ulnar neuritis, valgus extension overload with osteophyte formation and posteromedial impingement, flexor pronator strain, medial epicondyle pathology, and osteochondritis dissecans (OCD) of the capitellum have all been described as sequelae of the overhead throwing motion. In addition, loose body formation, bony spur formation, and capsular contracture can all be present in conjunction with these problems or as isolated entities. Not all pathology in the thrower's elbow is amenable to arthroscopic treatment; however, the clinician must be familiar with all of these problems in order to form a comprehensive differential diagnosis for an athlete presenting with elbow pain, and he or she must be comfortable with the variety of open and arthroscopic treatments available to best serve the patient. An understanding of the anatomy and biomechanics of the thrower's elbow is critical to the care of this population. The preoperative evaluation should focus on a thorough history and physical examination, as well as on specific diagnostic imaging modalities. Arthroscopic setup, including anesthesia, patient positioning, and portal choices will be discussed. Operative techniques in the anterior and posterior compartments will be reviewed, as well as postoperative rehabilitation and surgical results. Lastly, complications

  19. Exercise preconditioning attenuates pressure overload-induced pathological cardiac hypertrophy

    PubMed Central

    Xu, Tongyi; Tang, Hao; Zhang, Ben; Cai, Chengliang; Liu, Xiaohong; Han, Qingqi; Zou, Liangjian

    2015-01-01

    Pathological cardiac hypertrophy, a common response of the heart to a variety of cardiovascular diseases, is typically associated with myocytes remodeling and fibrotic replacement, cardiac dysfunction. Exercise preconditioning (EP) increases the myocardial mechanical load and enhances tolerance of cardiac ischemia-reperfusion injury (IRI), however, is less reported in pathological cardiac hypertrophy. To determine the effect of EP in pathological cardiac hypertrophy, Male 10-wk-old Sprague-Dawley rats (n=30) were subjected to 4 weeks of EP followed by 4-8 weeks of pressure overload (transverse aortic constriction, TAC) to induce pathological remodeling. TAC in untrained controls (n=30) led to pathological cardiac hypertrophy, depressed systolic function. We observed that left ventricular wall thickness in end diastole, heart size, heart weight-to-body weight ratio, heart weight-to-tibia length ratio, cross-sectional area of cardiomyocytes and the reactivation of fetal genes (atrial natriuretic peptide and brain natriuretic peptide) were markedly increased, meanwhile left ventricular internal dimension at end-diastole, systolic function were significantly decreased by TAC at 4 wks after operation (P < 0.01), all of which were effectively inhibited by EP treatment (P < 0.05), but the differences of these parameters were decreased at 8 wks after operation. Furthermore, EP treatment inhibited degradation of IκBα, and decreased NF-κB p65 subunit levels in the nuclear fraction, and then reduced IL2 levels in the myocardium of rats subject to TAC. EP can effectively attenuate pathological cardiac hypertrophic responses induced by TAC possibly through inhibition of degradation of IκB and blockade of the NF-κB signaling pathway in the early stage of pathological cardiac hypertrophy. PMID:25755743

  20. Metabolomic Analysis of Pressure-overloaded and Infarcted Mouse Hearts

    PubMed Central

    Sansbury, Brian E.; De Martino, Angelica M.; Xie, Zhengzhi; Brooks, Alan C.; Brainard, Robert E.; Watson, Lewis J.; DeFilippis, Andrew P.; Cummins, Timothy D.; Harbeson, Matthew A.; Brittian, Kenneth R.; Prabhu, Sumanth D.; Bhatnagar, Aruni; Jones, Steven P.; Hill, Bradford G.

    2014-01-01

    Background Cardiac hypertrophy and heart failure are associated with metabolic dysregulation and a state of chronic energy deficiency. Although several disparate changes in individual metabolic pathways have been described, there has been no global assessment of metabolomic changes in hypertrophic and failing hearts in vivo. Here, we investigated the impact of pressure overload and infarction on myocardial metabolism. Methods and Results Male C57BL/6J mice were subjected to transverse aortic constriction (TAC) or permanent coronary occlusion (myocardial infarction; MI). A combination of LC/MS/MS and GC/MS techniques was used to measure 288 metabolites in these hearts. Both TAC and MI were associated with profound changes in myocardial metabolism affecting up to 40% of all metabolites measured. Prominent changes in branched amino acids acids (BCAAs) were observed after 1 week of TAC and 5 days after MI. Changes in BCAAs after MI were associated with myocardial insulin resistance. Longer duration of TAC and MI led to a decrease in purines, acylcarnitines, fatty acids and several lysolipid and sphingolipid species, but a marked increase in pyrimidines as well as ascorbate, heme and other indices of oxidative stress. Cardiac remodeling and contractile dysfunction in hypertrophied hearts were associated also with large increases in myocardial, but not plasma, levels of the polyamines putrescine and spermidine as well as the collagen breakdown product prolylhydroxyproline. Conclusions These findings reveal extensive metabolic remodeling common to both hypertrophic and failing hearts that are indicative of extensive extracellular matrix remodeling, insulin resistance and perturbations in amino acid, lipid and nucleotide metabolism. PMID:24762972

  1. Effects of a Seven Day Overload-Period of High-Intensity Training on Performance and Physiology of Competitive Cyclists

    PubMed Central

    Clark, Bradley; Costa, Vitor P.; O'Brien, Brendan J.; Guglielmo, Luiz G.; Paton, Carl D.

    2014-01-01

    Objectives Competitive endurance athletes commonly undertake periods of overload training in the weeks prior to major competitions. This investigation examined the effects of two seven-day high-intensity overload training regimes (HIT) on performance and physiological characteristics of competitive cyclists. Design The study was a matched groups, controlled trial. Methods Twenty-eight male cyclists (mean ± SD, Age: 33±10 years, Mass 74±7 kg, VO2 peak 4.7±0.5 L·min−1) were assigned to a control group or one of two training groups for seven consecutive days of HIT. Before and after training cyclists completed an ergometer based incremental exercise test and a 20-km time-trial. The HIT sessions were ∼120 minutes in duration and consisted of matched volumes of 5, 10 and 20 second (short) or 15, 30 and 45 second (long) maximal intensity efforts. Results Both the short and long HIT regimes led to significant (p<0.05) gains in time trial performance compared to the control group. Relative to the control group, the mean changes (±90% confidence limits) in time-trial power were 8.2%±3.8% and 10.4%±4.3% for the short and long HIT regimes respectively; corresponding increases in peak power in the incremental test were 5.5%±2.7% and 9.5%±2.5%. Both HIT (short vs long) interventions led to non-significant (p>0.05) increases (mean ± SD) in VO2 peak (2.3%±4.7% vs 3.5%±6.2%), lactate threshold power (3.6%±3.5% vs 2.9%±5.3%) and gross efficiency (3.2%±2.4% vs 5.1%±3.9%) with only small differences between HIT regimes. Conclusions Seven days of overload HIT induces substantial enhancements in time-trial performance despite non-significant increases in physiological measures with competitive cyclists. PMID:25521824

  2. Characterization and accumulation of ferritin in hepatocyte nuclei of mice with iron overload

    SciTech Connect

    Smith, A.G.; Carthew, P.; Francis, J.E.; Edwards, R.E.; Dinsdale, D. )

    1990-12-01

    After a single subcutaneous dose of iron-dextran (600 mg of iron/kg), iron overload developed in C57BL/10ScSn mice. At 4, 24 and 78 wk liver nonheme iron concentrations were 67-, 42- and 21-fold higher than controls, respectively. Much of the iron was in macrophages, but hepatocytes were also strongly positive for Perls' stainable iron. One feature was the development of iron-positive nuclear inclusions in hepatocytes. After a delay of at least 8 wk when no stainable iron was evident, a maximum of 37% of periportal hepatocytes contained inclusions by 24 wk. Although this proportion remained constant for the remainder of the study, the size of the inclusions (which were not membrane-limited) increased to greater than 3 microns in diameter, occupying greater than 25% of the nuclear volume. The presence of iron in the inclusions was confirmed by energy dispersive x-ray microanalysis. Immunocytochemical studies showed that the iron was present as aggregates of ferritin. Quantitation of nonaggregated ferritin molecules by image analyses after electron microscopy demonstrated that within 4 wk ferritin levels in cytoplasm and nucleoplasm had greatly increased but that there was a concentration gradient of approximately one order of magnitude across the nuclear envelope. These findings are consistent with the hypothesis that in iron-loaded mouse hepatocytes there is a slow passage of ferritin-molecules through the nuclear pores; the gradient is maintained by the continual aggregation of ferritin within the nucleus. Intranuclear ferritin may provide a source of iron for catalyzing hydroxyl radical formation in nuclei during some toxic, carcinogenic and aging processes.

  3. Evolution of Residual-Strain Distribution through an Overload-Induced Retardation Period during Fatigue Crack Growth

    SciTech Connect

    Lee, S. Y.; Sun, Yinan; An, Ke; Choo, Hahn; Hubbard, Camden R; Liaw, Peter K

    2010-01-01

    Neutron diffraction was employed to investigate the crack-growth retardation phenomenon after a single tensile overload by mapping both one-dimensional and two-dimensional residual-strain distributions around the crack tip in a series of compact-tension specimens representing various crack-growth stages through an overload-induced retardation period. The results clearly show a large compressive residual-strain field near the crack tip immediately after the overload. As the fatigue crack propagates through the overload-induced plastic zone, the compressive residual strains are gradually relaxed, and a new compressive residual-strain field is developed around the propagating crack tip, illustrating that the subsequent fatigue-induced plastic zone grows out of the large plastic zone caused by the overloading. The relationship between the overload-induced plastic zone and subsequent fatigue-induced plastic zone, and its influence on the residual-strain distributions in the perturbed plastic zone are discussed.

  4. The attenuating effect of role overload on relationships linking self-efficacy and goal level to work performance.

    PubMed

    Brown, Steven P; Jones, Eli; Leigh, Thomas W

    2005-09-01

    The reported research examines the moderating effects of role overload on the antecedents and consequences of self-efficacy and personal goal level in a longitudinal study conducted in an industrial selling context. The results indicate that role overload moderates the antecedent effect of perceived organizational resources on self-efficacy beliefs. They also show that role overload moderates the direct effects of both self-efficacy and goal level on performance, such that these relationships are positive when role overload is low but not significant when role overload is high. Further, the results reveal a pattern of moderated mediation, in which goal level mediates the indirect effect of self-efficacy on performance when role overload is low but not when it is high. Implications for theory and managerial practice are discussed. PMID:16162069

  5. Genome-linked toxic responses to dietary iron overload.

    PubMed

    Whittaker, P; Dunkel, V C; Bucci, T J; Kusewitt, D F; Thurman, J D; Warbritton, A; Wolff, G L

    1997-01-01

    Genome-related differences to Fe overload between and within rodent species were evaluated in the present study. Male B6C3F1 mice, yellow and black C5YSF1 mice, and Fischer 344 (F344) rats were fed AIN-76A diets containing 35 (control), 1,500, 3,500, 5,000, or 10,000 micrograms carbonyl Fe/g for 12 wk. No effects on body weight gain were observed in the B6C3F1 and black C5YSF1 mice, whereas at all doses of Fe above the control, weight gain was reduced in yellow C5YSF1 mice and F344 rats. At the 10,000 micrograms Fe/g dose, 9 of 12 rats died, but there was no mortality among the mice. In all animals, there was a dose-related increase in liver nonheme Fe, and the Fe was stored in hepatocytes predominantly in the periportal region. There was significant hypertrophy of the hepatocytes in both B6C3F1 mice and F344 rats fed the 10,000 micrograms Fe/g diet. PCNA assays showed significant stimulatory effects of the high dose of Fe on hepatocyte proliferation in the F344 rats and the C5YSF1 mice but not in the B6C3F1 mice. In the rat, there was pancreatic atrophy with loss of both endocrine and exocrine tissue. Morphometric evaluation of pancreas showed fewer beta cells in B6C3F1 and yellow C5YSF1 mice but not in the black C5YSF1 mice. There were fewer islets in the yellow C5YSF1 mice, and total and mean islet areas were smaller than in the control mice. Rats in the 10,000 micrograms Fe/g dose group had markedly exacerbated dose-dependent nephropathy and changes in glomerular and tubular epithelium associated with Fe accumulation. The rats also showed degeneration of the germinal epithelium of the testis, formation of multinucleated giant cells, and lack of mature sperm. PMID:9437799

  6. Lactate dehydrogenase regulation in aged skeletal muscle: Regulation by anabolic steroids and functional overload.

    PubMed

    Washington, Tyrone A; Healey, Julie M; Thompson, Raymond W; Lowe, Larry L; Carson, James A

    2014-09-01

    Aging alters the skeletal muscle response to overload-induced growth. The onset of functional overload is characterized by increased myoblast proliferation and an altered muscle metabolic profile. The onset of functional overload is associated with increased energy demands that are met through the interconversion of lactate and pyruvate via the activity of lactate dehydrogenase (LDH). Testosterone targets many of the processes activated at the onset of functional overload. However, the effect of aging on this metabolic plasticity at the onset of functional overload and how anabolic steroid administration modulates this response is not well understood. The purpose of this study was to determine if aging would alter overload-induced LDH activity and expression at the onset of functional overload and whether anabolic steroid administration would modulate this response. Five-month and 25-month male Fischer 344xF1 BRN were given nandrolone decanoate (ND) or sham injections for 14days and then the plantaris was functionally overloaded (OV) for 3days by synergist ablation. Aging reduced muscle LDH-A & LDH-B activity 70% (p<0.05). Aging also reduced LDH-A mRNA abundance, however there was no age effect on LDH-B mRNA abundance. In 5-month muscle, both ND and OV decreased LDH-A and LDH-B activity. However, there was no synergistic or additive effect. In 5-month muscle, ND and OV decreased LDH-A mRNA expression with no change in LDH-B expression. In 25-month muscle, ND and OV increased LDH-A and LDH-B activity. LDH-A mRNA expression was not altered by ND or OV in aged muscle. However, there was a main effect of OV to decrease LDH-B mRNA expression. There was also an age-induced LDH isoform shift. ND and OV treatment increased the "fast" LDH isoforms in aged muscle, whereas ND and OV increased the "slow" isoforms in young muscle. Our study provides evidence that aging alters aspects of skeletal muscle metabolic plasticity normally induced by overload and anabolic steroid

  7. Intermittent pressure overload triggers hypertrophy-independent cardiac dysfunction and vascular rarefaction

    PubMed Central

    Perrino, Cinzia; Prasad, Sathyamangla V. Naga; Mao, Lan; Noma, Takahisa; Yan, Zhen; Kim, Hyung-Suk; Smithies, Oliver; Rockman, Howard A.

    2006-01-01

    For over a century, there has been intense debate as to the reason why some cardiac stresses are pathological and others are physiological. One long-standing theory is that physiological overloads such as exercise are intermittent, while pathological overloads such as hypertension are chronic. In this study, we hypothesized that the nature of the stress on the heart, rather than its duration, is the key determinant of the maladaptive phenotype. To test this, we applied intermittent pressure overload on the hearts of mice and tested the roles of duration and nature of the stress on the development of cardiac failure. Despite a mild hypertrophic response, preserved systolic function, and a favorable fetal gene expression profile, hearts exposed to intermittent pressure overload displayed pathological features. Importantly, intermittent pressure overload caused diastolic dysfunction, altered β-adrenergic receptor (βAR) function, and vascular rarefaction before the development of cardiac hypertrophy, which were largely normalized by preventing the recruitment of PI3K by βAR kinase 1 to ligand-activated receptors. Thus stress-induced activation of pathogenic signaling pathways, not the duration of stress or the hypertrophic growth per se, is the molecular trigger of cardiac dysfunction. PMID:16741575

  8. Mitochondrial Ca2+ Overload Underlies Aβ Oligomers Neurotoxicity Providing an Unexpected Mechanism of Neuroprotection by NSAIDs

    PubMed Central

    Sanz-Blasco, Sara; Valero, Ruth A.; Rodríguez-Crespo, Ignacio; Villalobos, Carlos; Núñez, Lucía

    2008-01-01

    Dysregulation of intracellular Ca2+ homeostasis may underlie amyloid β peptide (Aβ) toxicity in Alzheimer's Disease (AD) but the mechanism is unknown. In search for this mechanism we found that Aβ1–42 oligomers, the assembly state correlating best with cognitive decline in AD, but not Aβ fibrils, induce a massive entry of Ca2+ in neurons and promote mitochondrial Ca2+ overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Aβ oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca2+ overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs) including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca2+ overload, cytochrome c release and cell death induced by Aβ oligomers. Our results indicate that i) mitochondrial Ca2+ overload underlies the neurotoxicity induced by Aβ oligomers and ii) inhibition of mitochondrial Ca2+ overload provides a novel mechanism of neuroprotection by NSAIDs against Aβ oligomers and AD. PMID:18648507

  9. Oral exfoliative cytology as a screening tool for iron overload in β-thalassemia patients

    PubMed Central

    Rathore, Ajit Singh; Keshri, Neha; Shetty, Devi Charan; Juneja, Saurabh

    2016-01-01

    Background: Increased iron overload is frequent problem in thalassemia patients, and this is monitored by serum ferritin levels or chemical assessment of the iron levels in liver tissue. However, repeated monitoring of serum ferritin levels to assess the iron overload is an invasive procedure associated with practical problems. Aims: To use Perl's Prussian blue reaction to evaluate the iron overload in beta-thalassemia patients by staining the oral cytosmears. Materials and Methods: The study comprised 35 patients diagnosed with beta-thalassemia. Cytosmears were prepared from exfoliated oral epithelial cells, fixed in 70% ethanol and stained with Perl's Prussian blue stain for detection of blue colored granules in the cytoplasm. Results: 29/35 (82.9%) cases showed a positive reaction for Perl's Prussian blue reaction while 6/35 (17%) cases did not show the presence of blue colored granules in the oral cytosmears. The presence of iron detected by Perl's Prussian blue reaction correlated with serum ferritin level (P < 0.05). Conclusion: Perl's Prussian blue reaction can be used to evaluate the iron overload in beta-thalassemia patients by staining the oral cytosmears. It is a simple and noninvasive method for assessment of iron overload in such patients. PMID:26958519

  10. AMPKγ3 is dispensable for skeletal muscle hypertrophy induced by functional overload.

    PubMed

    Riedl, Isabelle; Osler, Megan E; Björnholm, Marie; Egan, Brendan; Nader, Gustavo A; Chibalin, Alexander V; Zierath, Juleen R

    2016-03-15

    Mechanisms regulating skeletal muscle growth involve a balance between the activity of serine/threonine protein kinases, including the mammalian target of rapamycin (mTOR) and 5'-AMP-activated protein kinase (AMPK). The contribution of different AMPK subunits to the regulation of cell growth size remains inadequately characterized. Using AMPKγ3 mutant-overexpressing transgenic Tg-Prkag3(225Q) and AMPKγ3-knockout (Prkag3(-/-)) mice, we investigated the requirement for the AMPKγ3 isoform in functional overload-induced muscle hypertrophy. Although the genetic disruption of the γ3 isoform did not impair muscle growth, control sham-operated AMPKγ3-transgenic mice displayed heavier plantaris muscles in response to overload hypertrophy and underwent smaller mass gain and lower Igf1 expression compared with wild-type littermates. The mTOR signaling pathway was upregulated with functional overload but unchanged between genetically modified animals and wild-type littermates. Differences in AMPK-related signaling pathways between transgenic, knockout, and wild-type mice did not impact muscle hypertrophy. Glycogen content was increased following overload in wild-type mice. In conclusion, our functional, transcriptional, and signaling data provide evidence against the involvement of the AMPKγ3 isoform in the regulation of skeletal muscle hypertrophy. Thus, the AMPKγ3 isoform is dispensable for functional overload-induced muscle growth. Mechanical loading can override signaling pathways that act as negative effectors of mTOR signaling and consequently promote skeletal muscle hypertrophy. PMID:26758685

  11. Shape-memory alloy overload protection device for osseointegrated transfemoral implant prosthetic limb attachment system

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Shao, Fei; Hughes, Steven

    2002-11-01

    The osseointegrated trans-femoral implant system provides a direct anchoring technique to attach prosthetic limb. This technique was first introduced PI Brenmark in Sweden. The UK had the first clinical trial in 1997 and currently has 6 active limb wearers. The success of this procedure has the potential for improved gait function and mobility, increased employability and significant long-term improvements in the quality of life for above knee amputees. However, the significant load involved in the trans-femoral implant system has caused permanent deformation and/or fractures of the implant abutment in several occasions. To protect the implant system, the implant abutment in particularly, an overloading protection device was introduced. The device uses mechanical mechanism to release torsion overload on the abutment. However, the bending overload protection remains unsolved. To solve the problem, a new overload protection device was developed. This device uses SMA component for bending overload protection. In this paper, the results of non-linear finite element modelling of the SMA and steel (AISI 1040) components were presented. Experiments were also carried out using steel components to assess the design which is based on the non-linear property of the materials.

  12. Mechanism of chronic dietary iron overload-induced liver damage in mice.

    PubMed

    Liu, Dan; He, Huan; Yin, Dong; Que, Ailing; Tang, Lei; Liao, Zhangping; Huang, Qiren; He, Ming

    2013-04-01

    Chronic iron overload may result in hepatic fibrosis and even neoplastic transformation due to a burst of reactive oxygen species (ROS). Mitochondria have been proposed to be important in the production of ROS. The purpose of this study was to investigate the role of the mitochondrial permeability transition pore (mPTP) in the burst of ROS, and to clarify the mechanism whereby ROS induced by iron overload results in hepatic damage. It has been demonstrated that when ferrocene-induced iron-overloaded mice were fed the cyclosporin A (CsA), a specific inhibitor of the mPTP, diet (10 mg/kg/day) for 50 days, liver-to-body weight ratio, serum levels of alanine transaminase (ALT) and aspartate transaminase (AST), ROS production, mitochondrial swelling, loss of mitochondrial membrane potential (Δψ) and hepatocyte apoptosis decreased. However, the total antioxidant status, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase activities, increased. The protective effect of CsA on the liver of iron-overloaded mice may be due to inhibition of the ROS burst and a successive antioxidant effect. To the best of our knowledge, these data provide the first support for the theory that ROS-induced ROS release (RIRR) may be involved in the burst of ROS in the liver and greatly contribute to the hepatic damage initiated by iron overload. PMID:23404080

  13. A retrospective review of patient factors, transfusion practices, and outcomes in patients with transfusion-associated circulatory overload.

    PubMed

    Lieberman, Lani; Maskens, Carolyn; Cserti-Gazdewich, Christine; Hansen, Mark; Lin, Yulia; Pendergrast, Jacob; Yi, Qi Long; Callum, Jeannie

    2013-10-01

    Transfusion-associated circulatory overload (TACO) is a common yet underrecognized and underreported complication of transfusion associated with significant morbidity and mortality. The objective of this study was to examine patient and transfusion characteristics in a cohort of TACO cases. A retrospective medical record review of 100 consecutive TACO episodes reported at 2 academic centers was performed. Information related to demographics, medical history, radiologic and echocardiographic investigations, infusion practices, reaction features, management, and outcome were collected. Ninety-eight cases were accessible for review. A history of congestive heart failure (41%), renal dysfunction (44%), and age more than 70 years (56%) were common in TACO patients. Suboptimal fluid status management and inappropriate infusion practices were often seen (eg, verbal orders, double red cell transfusions, rapid infusion rates, lack or improper timing of preemptive diuretics). The median volume of blood ordered was 500 mL, and the median volume of crystalloid or colloid (preceding 24 hours) was 2200 mL. A physician order specifying the infusion rate was documented in 50% of transfusion orders. Preemptive diuretics were ordered in only 29% of cases, most commonly introduced midway or after the transfusion at a dose of furosemide 20 mg intravenously. After TACO, 18% of patients required transfer to the intensive care unit, 8% suffered a major complication, and 2% died. Suboptimal ordering and infusion practices may be contributing to the high incidence and severity of TACO. Research in TACO prevention strategies, such as slow rates of infusion and preemptive diuretics, is warranted. PMID:24075097

  14. Modeling of self-healing against cascading overload failures in complex networks

    NASA Astrophysics Data System (ADS)

    Liu, Chaoran; Li, Daqing; Fu, Bowen; Yang, Shunkun; Wang, Yunpeng; Lu, Guangquan

    2014-09-01

    The development of online prognostic and fast-recovery technology promotes the realization of self-healing techniques. Considering the cascading overload failures as one of the major failure modes in real networks, we introduce a model for self-healing against overload propagation in complex networks due to malicious attack. Especially, we study the role of basic quantities (restoration timing and resource) in general self-healing restoration against cascading overload failures in network models of homogeneous (Erdős-Rényi) and heterogeneous (scale-free) networks. We demonstrate how networks during cascading failures can be saved from the brink of collapse by proper combination of both restoration timing and resource. And we find that optimal restoration timing for the model and realistic networks exists at a given restoration resource in the self-healing process.

  15. Early characterization of occlusal overloaded cervical dental hard tissues by en face optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Marcauteanu, Corina; Negrutiu, Meda; Sinescu, Cosmin; Stoica, Eniko Tunde; Ionita, Ciprian; Florin, Topala; Vasile, Liliana; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

    2011-06-01

    Early diagnosis of occlusal overload is an important issue in dental medicine. The high occlusal forces can cause irreversible damage to the dental hard tissues. Our study proposes the early microstructural characterization of occlusal overloaded bicuspids, with abnormal crown morphology, by en face optical coherence tomography (eFOCT). The dental samples were investigated using an eFOCT system operating at 1300 nm in B-scan and C-scan mode. The eFOCT images obtained from these teeth visualized cracks, which didn't reach the tooth surface. The μCT and histological images confirmed the microstructural defects identified on eFOCT images. In conclusion, eFOCT is a promising imaging method for the early diagnosis of occlusal overload on bicuspids with normal crown morphology and for the prophylaxis of dental wear.

  16. Information Diffusion in Facebook-Like Social Networks Under Information Overload

    NASA Astrophysics Data System (ADS)

    Li, Pei; Xing, Kai; Wang, Dapeng; Zhang, Xin; Wang, Hui

    2013-07-01

    Research on social networks has received remarkable attention, since many people use social networks to broadcast information and stay connected with their friends. However, due to the information overload in social networks, it becomes increasingly difficult for users to find useful information. This paper takes Facebook-like social networks into account, and models the process of information diffusion under information overload. The term view scope is introduced to model the user information-processing capability under information overload, and the average number of times a message appears in view scopes after it is generated is proposed to characterize the information diffusion efficiency. Through theoretical analysis, we find that factors such as network structure and view scope number have no impact on the information diffusion efficiency, which is a surprising result. To verify the results, we conduct simulations and provide the simulation results, which are consistent with the theoretical analysis results perfectly.

  17. An alternating current superconductor susceptometric system to evaluate liver iron overload

    NASA Astrophysics Data System (ADS)

    Carneiro, A. A. O.; Fernandes, J. P.; Zago, M. A.; Covas, D. T.; Ángulo, I. L.; Baffa, O.

    2003-06-01

    An ac susceptometric system to quantify liver iron overload composed of a second order axial gradiometer coil coupled to a rf superconducting quantum interference device detector and a large field coil array is presented. A homogeneous ac magnetizing field with low frequency (7.7 Hz) and low intensity (114 μT) is used. Preliminary measurements over a group of 34 normal individuals and 20 patients with iron overload show the ability of the instrument to perform the measurement and to distinguish normal and pathological individuals. The diamagnetic signature of the surrounding tissues is minimized using a special water bag on the torso. In summary it was shown that with a relatively simple instrumentation it was possible to build a superconducting susceptometer dedicated to quantify in vivo iron concentrations, which is clinically important information in the assessment and management of patients with liver iron overload, mainly those who regularly receive blood transfusion.

  18. Experimental animal model to study iron overload and iron chelation and review of other such models.

    PubMed

    Italia, Khushnooma; Colah, Roshan; Ghosh, Kanjaksha

    2015-10-01

    The disorders of iron overload due to primary or secondary cause are one of the important human diseases leading to high mortality if untreated. To understand this, an animal model has been extensively studied. The source of iron administered to the mode of iron administration that can mimic the iron overload in humans has been studied. A safe and orally active iron chelator is still needed as many of the existing compounds have different types of complications and toxicity associated. Hence having a simple animal model which can be availed quickly and can be used to study various compounds for its iron chelating activity would likely to have immense utility for pharmacological studies. In this review we have shown how, using a simple procedure, a large number of small iron overloaded animals can be produced easily for various studies. PMID:26227843

  19. Using shot-change information to prevent an overload of platform resources

    NASA Astrophysics Data System (ADS)

    Wubben, Rob H. M.; Hentschel, Christian

    2003-06-01

    Future consumer terminals (TV sets, set-top boxes, displays) will increasingly be based on programmable platforms instead of only dedicated hardware. When the available resources are insufficient to deal with the worst-case requirements then resource overloads might lead to system instability and reduced output quality. For robust and cost-effective media processing on programmable platforms, dynamic resource management is required together with resource-quality scalable video algorithms. A way to prevent resource overloads is to stop processing when the assigned resources have been used. This may lead to drops and changes in quality. We propose to use shot-change information prior to the actual processing to predict difficult situations and react on them in a proper way. For a scalable motion estimator we show that, after a shot-change, generating motion vectors that indicate zero or close to zero motion prevents overloads, saves resources and can lead to a higher quality.

  20. Marital status, pregnancy planning, and role overload: a mediated-moderation model of parenting satisfaction.

    PubMed

    Lachance-Grzela, Mylène; Bouchard, Geneviève

    2009-10-01

    This longitudinal study investigated the presence of a moderating effect of pregnancy planning on the relationship between marital status and parenting satisfaction of couples experiencing the transition to parenthood and verified whether this moderating effect is mediated by role overload. Data were collected from 150 Canadian couples during the 3rd trimester of pregnancy and at 9 months postpartum. Findings reveal that when the pregnancy is planned, the poorer parenting satisfaction reported by cohabiting fathers in comparison with their married counterparts can be explained by cohabiting men's higher levels of role overload. Women's levels of parenting satisfaction are also influenced by their own and their partner's experiences of role overload. Results are discussed in terms of the respective values and lifestyles of cohabiting and married couples and specifically in terms of their different attitudes toward egalitarianism. PMID:19803609

  1. Acute phase reaction and acute phase proteins*

    PubMed Central

    Gruys, E.; Toussaint, M.J.M.; Niewold, T.A.; Koopmans, S.J.

    2005-01-01

    A review of the systemic acute phase reaction with major cytokines involved, and the hepatic metabolic changes, negative and positive acute phase proteins (APPs) with function and associated pathology is given. It appears that APPs represent appropriate analytes for assessment of animal health. Whereas they represent non-specific markers as biological effect reactants, they can be used for assessing nutritional deficits and reactive processes, especially when positive and negative acute phase variables are combined in an index. When such acute phase index is applied to separate healthy animals from animals with some disease, much better results are obtained than with single analytes and statistically acceptable results for culling individual animals may be reached. Unfortunately at present no cheap, comprehensive and easy to use system is available for assessing various acute phase proteins in serum or blood samples at the same time. Protein microarray or fluid phase microchip technology may satisfy this need; and permit simultaneous analysis of numerous analytes in the same small volume sample and enable integration of information derived from systemic reactivity and nutrition with disease specific variables. Applying such technology may help to solve health problems in various countries not only in animal husbandry but also in human populations. PMID:16252337

  2. Overload-induced skeletal muscle hypertrophy is not impaired in STZ-diabetic rats

    PubMed Central

    Fortes, Marco Aurélio S; Pinheiro, Carlos Hermano J; Guimarães-Ferreira, Lucas; Vitzel, Kaio F; Vasconcelos, Diogo A A; Curi, Rui

    2015-01-01

    The aim of this study was to evaluate the effect of overload-induced hypertrophy on extensor digitorum longus (EDL) and soleus muscles of streptozotocin-induced diabetic rats. The overload-induced hypertrophy and absolute tetanic and twitch forces increases in EDL and soleus muscles were not different between diabetic and control rats. Phospho-Akt and rpS6 contents were increased in EDL muscle after 7 days of overload and returned to the pre-overload values after 30 days. In the soleus muscle, the contents of total and phospho-Akt and total rpS6 were increased in both groups after 7 days. The contents of total Akt in controls and total rpS6 and phospho-Akt in the diabetic rats remained increased after 30 days. mRNA expression after 7 days of overload in the EDL muscle of control and diabetic animals showed an increase in MGF and follistatin and a decrease in myostatin and Axin2. The expression of FAK was increased and of MuRF-1 and atrogin-1 decreased only in the control group, whereas Ankrd2 expression was enhanced only in diabetic rats. In the soleus muscle caused similar changes in both groups: increase in FAK and MGF and decrease in Wnt7a, MuRF-1, atrogin-1, and myostatin. Differences between groups were observed only in the increased expression of follistatin in diabetic animals and decreased Ankrd2 expression in the control group. So, insulin deficiency does not impair the overload-induced hypertrophic response in soleus and EDL muscles. However, different mechanisms seem to be involved in the comparable hypertrophic responses of skeletal muscle in control and diabetic animals. PMID:26197932

  3. Iron overload of human colon adenocarcinoma cells studied by synchrotron-based X-ray techniques.

    PubMed

    Mihucz, Victor G; Meirer, Florian; Polgári, Zsófia; Réti, Andrea; Pepponi, Giancarlo; Ingerle, Dieter; Szoboszlai, Norbert; Streli, Christina

    2016-04-01

    Fast- and slow-proliferating human adenocarcinoma colorectal cells, HT-29 and HCA-7, respectively, overloaded with transferrin (Tf), Fe(III) citrate, Fe(III) chloride and Fe(II) sulfate were studied by synchrotron radiation total-reflection X-ray spectrometry (TXRF), TXRF-X-ray absorption near edge structure (TXRF-XANES), and micro-X-ray fluorescence imaging to obtain information on the intracellular storage of overloaded iron (Fe). The determined TfR1 mRNA expression for the investigated cells correlated with their proliferation rate. In all cases, the Fe XANES of cells overloaded with inorganic Fe was found to be similar to that of deliquescent Fe(III) sulfate characterized by a distorted octahedral geometry. A fitting model using a linear combination of the XANES of Tf and deliquescent Fe(III) sulfate allowed to explain the near edge structure recorded for HT-29 cells indicating that cellular overload with inorganic Fe results in a non-ferritin-like fast Fe storage. Hierarchical cluster analysis of XANES spectra recorded for Fe overloaded HT-29 and HCA-7 cells was able to distinguish between Fe treatments performed with different Fe species with a 95 % hit rate, indicating clear differences in the Fe storage system. Micro-X-ray fluorescence imaging of Fe overloaded HT-29 cells revealed that Fe is primarily located in the cytosol of the cells. By characterizing the cellular Fe uptake, Fe/S content ratios were calculated based on the X-ray fluorescence signals of the analytes. These Fe/S ratios were dramatically lower for HCA-7 treated with organic Fe(III) treatments suggesting dissimilarities from the Tf-like Fe uptake. PMID:26759251

  4. Interstitial nephritis induced by protein-overload proteinuria.

    PubMed Central

    Eddy, A. A.

    1989-01-01

    Experimental nephrotic syndrome induced by several immunologic and biochemical methods is associated with the development of tubulointerstitial nephritis (TIN). To investigate the hypothesis that severe sustained proteinuria plays a role in the pathogenesis of TIN, the renal interstitium in a model of protein-overload proteinuria was studied. After uninephrectomy, rats received daily injections of 1.0 g of bovine serum albumin (BSA) or saline (controls) until killing at 1, 2, 4, or 7 weeks. Sections of frozen renal cortex were stained with a panel of monoclonal antibodies reactive with subsets of rat lymphohemopoietic cells, and positive tubulointerstitial cells (TIC) were quantitated by epifluorescence microscopy. BSA rats developed proteinuria, with mean rat urinary albumin excretion rates at 1, 2, 3, and 6 weeks of 35.6 +/- 21.8, 97.2 +/- 46.1, 63.6 +/- 40.8, and 58.6 +/- 24.4 mg/24 hours, respectively (controls, 0.17 +/- 0.16 mg/24 hours). BSA was detectable in the plasma of experimental animals at all periods, with mean values of 26.8 +/- 3.8, 27.8 +/- 2.7, 20.3 +/- 6.2, and 7.0 +/- 1.1 mg/ml (controls, 0.03 +/- 0.04 mg/ml) at 1, 2, 4, and 7 weeks, respectively, whereas plasma anti-BSA antibodies were never detected. A significant mononuclear cell infiltrate was present in the interstitium of experimental animals at all periods. At 1 week, an influx of macrophages was evident that was identified by surface markers OX42 (75+/1000 TIC) (P less than 0.01) and Ia (58+/1000 TIC) (P less than 0.01). Macrophages dominated the infiltrate at all periods. By 2 weeks, a significant population of lymphocytes was also present that was identified by the surface marker OX19 (54+/1000 TIC) (P less than 0.01). This early lymphocytic infiltrate was a mixed lesion of T helper and T cytotoxic cells. However, at 4 and 7 weeks, most lymphocytes expressed the OX8 cytotoxic T cell marker. The proximal tubules of proteinuric rats expressed vimentin intermediate filaments, a marker of

  5. Reducing Information Overload in Large Seismic Data Sets

    SciTech Connect

    HAMPTON,JEFFERY W.; YOUNG,CHRISTOPHER J.; MERCHANT,BION J.; CARR,DORTHE B.; AGUILAR-CHANG,JULIO

    2000-08-02

    Event catalogs for seismic data can become very large. Furthermore, as researchers collect multiple catalogs and reconcile them into a single catalog that is stored in a relational database, the reconciled set becomes even larger. The sheer number of these events makes searching for relevant events to compare with events of interest problematic. Information overload in this form can lead to the data sets being under-utilized and/or used incorrectly or inconsistently. Thus, efforts have been initiated to research techniques and strategies for helping researchers to make better use of large data sets. In this paper, the authors present their efforts to do so in two ways: (1) the Event Search Engine, which is a waveform correlation tool and (2) some content analysis tools, which area combination of custom-built and commercial off-the-shelf tools for accessing, managing, and querying seismic data stored in a relational database. The current Event Search Engine is based on a hierarchical clustering tool known as the dendrogram tool, which is written as a MatSeis graphical user interface. The dendrogram tool allows the user to build dendrogram diagrams for a set of waveforms by controlling phase windowing, down-sampling, filtering, enveloping, and the clustering method (e.g. single linkage, complete linkage, flexible method). It also allows the clustering to be based on two or more stations simultaneously, which is important to bridge gaps in the sparsely recorded event sets anticipated in such a large reconciled event set. Current efforts are focusing on tools to help the researcher winnow the clusters defined using the dendrogram tool down to the minimum optimal identification set. This will become critical as the number of reference events in the reconciled event set continually grows. The dendrogram tool is part of the MatSeis analysis package, which is available on the Nuclear Explosion Monitoring Research and Engineering Program Web Site. As part of the research

  6. Raised serum ferritin concentration in hereditary hyperferritinemia cataract syndrome is not a marker for iron overload.

    PubMed

    Yin, Dan; Kulhalli, Vasu; Walker, Ann P

    2014-03-01

    Hyperferritinemia and bilateral cataracts are features of the rare hereditary hyperferritinemia cataract syndrome (HHCS; OMIM #600886). HHCS is an autosomal dominant condition caused by mutations which increase expression of the ferritin light polypeptide (FTL) gene. We report a patient with HHCS who was misdiagnosed and treated as having hemochromatosis, in whom a heterozygous c.-160A>G mutation was identified in the iron responsive element (IRE) of FTL, causing ferritin synthesis in the absence of iron overload. This report demonstrates the need for clinical awareness of HHCS as a cause of hyperferritinemia in the absence of iron overload and provides a possible diagnostic schema. PMID:24003015

  7. Yersinia enterocolitica Septicemia After Chitterling Ingestion in a Pediatric Patient With Iron Overload Disease

    PubMed Central

    Moon, Tara D.; Ma, Steven

    2015-01-01

    Yersinia enterocolitica is a gram-negative cocobacillus causing a range of illness from self-limited enteritis to invasive disease, including septicemia. It is a particularly virulent pathogen in patients with underlying hemoglobinopathies who are predisposed to iron overload. A substantial risk factor for disease in children and infants is exposure to the household preparation of chitterlings. Early identification of these patients is critical in the pediatric intensive care unit as this cause of septicemia can be missed with the potential for significant morbidity. We report an interesting case of Yersinia septicemia in a patient with iron overload disease from chitterling ingestion managed in the pediatric intensive care unit.

  8. [Risk assessment of biomechanical overload of the limbs and spine in workers paving roads with stones].

    PubMed

    Sala, E; Bonfiglioli, R; Violante, F S; Apostoli, P

    2012-01-01

    Aim of this study is to assess the risk from biomechanical overload for the whole musculoskeletal system and manual handling involved in the activity of stone paving of the road. According to the guidelines of the Italian Society of Occupational Medicine and Industrial Hygiene various risk assessment methods have been used: Washington State checklist, checklist of Turin and OCRA checklist to assess the risk from biomechanical overload for the upper limb and NIOSH method with the method provided by the State of Washington to assess the risk from manual handling of loads. PMID:23405585

  9. Occlusal overload investigations by noninvasive technology: fluorescence microscopy and en-face optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Marcauteanu, Corina; Negrutiu, Meda; Sinescu, Cosmin; Demjan, Enikö; Hughes, Michael; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

    2009-07-01

    The aim of this study is the early detection and monitoring of occlusal overload in bruxing patients. En-Face Optical coherence tomography (eF-OCT) and fluorescence microscopy (FM) were used for the imaging of several anterior teeth extracted from patients with light active bruxism. We found a characteristic pattern of enamel cracks, that reached the tooth surface. We concluded that the combination of the en-Face OCT and FM is a promising non-invasive alternative technique for reliable monitoring of occlusal overload.

  10. Iron Overload Leading to Torsades de Pointes in β-Thalassemia and Long QT Syndrome.

    PubMed

    Refaat, Marwan M; El Hage, Lea; Steffensen, Annette Buur; Hotait, Mostafa; Schmitt, Nicole; Scheinman, Melvin; Badhwar, Nitish

    2016-03-01

    The authors present a unique case of torsades de pointes in a β-thalassemia patient with early iron overload in the absence of any structural abnormalities as seen in hemochromatosis. Genetic testing showed a novel KCNQ1 gene mutation 1591C>T [Gln531Ter(X)]. Testing of the gene mutation in Xenopus laevis oocytes showed loss of function of the IKs current. The authors hypothesize that iron overload combined with the KCNQ1 gene mutation leads to prolongation of QTc and torsades de pointes. PMID:26920202

  11. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation.

    PubMed

    Liu, Xiao-Wei; Jin, Yan; Ma, Tao; Qu, Bo; Liu, Zhi

    2015-01-01

    This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (V T ), ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (C rs) decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP) were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2% at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV. PMID:25954759

  12. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation

    PubMed Central

    Liu, Xiao-Wei; Jin, Yan; Ma, Tao; Qu, Bo; Liu, Zhi

    2015-01-01

    This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT), ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (Crs) decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP) were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2 % at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV. PMID:25954759

  13. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 75.518-1 Section 75.518-1 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Electrical Equipment-General § 75.518-1 Electric equipment and circuits; overload...

  14. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 77.506-1 Section 77.506-1 Mineral Resources MINE...

  15. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 75.518-1 Section 75.518-1 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Electrical Equipment-General § 75.518-1 Electric equipment and circuits; overload...

  16. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 77.506-1 Section 77.506-1 Mineral Resources MINE...

  17. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 77.506-1 Section 77.506-1 Mineral Resources MINE...

  18. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 77.506-1 Section 77.506-1 Mineral Resources MINE...

  19. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 75.518-1 Section 75.518-1 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Electrical Equipment-General § 75.518-1 Electric equipment and circuits; overload...

  20. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 75.518-1 Section 75.518-1 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Electrical Equipment-General § 75.518-1 Electric equipment and circuits; overload...

  1. 30 CFR 75.518-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload and short circuit protection; minimum requirements. 75.518-1 Section 75.518-1 Mineral Resources MINE SAFETY...-UNDERGROUND COAL MINES Electrical Equipment-General § 75.518-1 Electric equipment and circuits; overload...

  2. The Impact of Information Overload on Task Completion: A Study of Scientists and Engineers in a Typical Work Environment

    ERIC Educational Resources Information Center

    Salyers, Jessica L.

    2013-01-01

    As use of technology has increasingly infiltrated the daily lives of many Americans, information overload has become a more prevalent fixture for men and women both at home and in the workplace. While information overload has been established in the field of psychology in various forms, it lacks a universal definition within the discipline.…

  3. Pressure overload induces IL-18 and IL-18R expression, but markedly suppresses IL-18BP expression in a rabbit model. IL-18 potentiates TNF-α-induced cardiomyocyte death

    PubMed Central

    Yoshida, Tadashi; Friehs, Ingeborg; Mummidi, Srinivas; del Nido, Pedro J.; Addulnour-Nakhoul, Solange; Delafontaine, Patrice; Valente, Anthony J.; Chandrasekar, Bysani

    2014-01-01

    Recurrent or sustained inflammation plays a causal role in the development and progression of left ventricular hypertrophy (LVH) and its transition to failure. Interleukin (IL)-18 is a potent pro-hypertrophic inflammatory cytokine. We report that induction of pressure overload in the rabbit, by constriction of the descending thoracic aorta induces compensatory hypertrophy at 4 weeks (mass/volume ratio: 1.7±0.11) and ventricular dilatation indicative of heart failure at 6 weeks (mass/volume ratio: 0.7±0.04). In concordance with this, fractional shortening was preserved at 4 weeks, but markedly attenuated at 6 weeks. We cloned rabbit IL-18, IL-18Rα, IL-18Rβ, and IL-18 binding protein (IL-18BP) cDNA, and show that pressure overload, while enhancing IL-18 and IL-18R expression in hypertrophied and failing hearts, markedly attenuated the level of expression of the endogenous IL-18 antagonist IL-18BP. Cyclical mechanical stretch (10% cyclic equibiaxial stretch, 1 Hz) induced hypertrophy of primary rabbit cardiomyocytes in vitro and enhanced ANP, IL-18, and IL-18Rα expression. Further, treatment with rhIL-18 induced its own expression and that of IL-18Rα via AP-1 activation, and induced cardiomyocyte hypertrophy in part via PI3K/Akt-dependent GATA4 activation. In contrast, IL-18 potentiated TNF-α-induced cardiomyocyte death, and induced cardiac endothelial cell death. These results demonstrate that pressure overload is associated with enhanced IL-18 and its receptor expression in hypertrophied and failing myocardium in rabbits. Since IL-18BP expression is markedly inhibited, our results indicate a positive amplification in IL-18 pro-inflammatory signaling during pressure overload, and suggest IL-18 as a potential therapeutic target in pathological hypertrophy and cardiac failure. PMID:25108227

  4. Acute Bronchitis

    MedlinePlus

    Bronchitis is an inflammation of the bronchial tubes, the airways that carry air to your lungs. It ... chest tightness. There are two main types of bronchitis: acute and chronic. Most cases of acute bronchitis ...

  5. Nonalcoholic Fatty Liver Disease Is Associated With Higher 1-year All-Cause Rehospitalization Rates in Patients Admitted for Acute Heart Failure.

    PubMed

    Valbusa, Filippo; Bonapace, Stefano; Grillo, Cristina; Scala, Luca; Chiampan, Andrea; Rossi, Andrea; Zoppini, Giacomo; Lonardo, Amedeo; Arcaro, Guido; Byrne, Christopher D; Targher, Giovanni

    2016-02-01

    Repeat hospitalization due to acute heart failure (HF) is a global public health problem that markedly impacts on health resource use. Identifying novel predictors of rehospitalization would help physicians to determine the optimal postdischarge plan for preventing HF rehospitalization. Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for many heart diseases, including HF. We assessed whether NAFLD at hospital admission predicts 1-year all-cause rehospitalization in patients with acute HF. We enrolled all patients consecutively admitted for acute HF to our General Medicine Division, from January 2013 to April 2014, after excluding patients with acute myocardial infarction, severe heart valve diseases, malignancy, known liver diseases, and those with volume overload related to extracardiac causes. NAFLD was diagnosed by ultrasonography and exclusion of competing etiologies. The primary outcome of the study was the 1-year all-cause rehospitalization rate. Among the 107 patients enrolled in the study, the cumulative rehospitalization rate was 12.1% at 1 month, 25.2% at 3 months, 29.9% at 6 months, and 38.3% at 1 year. Patients with NAFLD had markedly higher 1-year rehospitalization rates than those without NAFLD (58% vs 21% at 1 y; P < 0.001 by the log-rank test). Cox regression analysis revealed that NAFLD was associated with a 5.5-fold increased risk of rehospitalization (adjusted hazard ratio 5.56, 95% confidence interval 2.46-12.1, P < 0.001) after adjustment for multiple HF risk factors and potential confounders. In conclusion, NAFLD was independently associated with higher 1-year rehospitalization in patients hospitalized for acute HF. PMID:26886619

  6. Nonalcoholic Fatty Liver Disease Is Associated With Higher 1-year All-Cause Rehospitalization Rates in Patients Admitted for Acute Heart Failure

    PubMed Central

    Valbusa, Filippo; Bonapace, Stefano; Grillo, Cristina; Scala, Luca; Chiampan, Andrea; Rossi, Andrea; Zoppini, Giacomo; Lonardo, Amedeo; Arcaro, Guido; Byrne, Christopher D.; Targher, Giovanni

    2016-01-01

    Abstract Repeat hospitalization due to acute heart failure (HF) is a global public health problem that markedly impacts on health resource use. Identifying novel predictors of rehospitalization would help physicians to determine the optimal postdischarge plan for preventing HF rehospitalization. Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for many heart diseases, including HF. We assessed whether NAFLD at hospital admission predicts 1-year all-cause rehospitalization in patients with acute HF. We enrolled all patients consecutively admitted for acute HF to our General Medicine Division, from January 2013 to April 2014, after excluding patients with acute myocardial infarction, severe heart valve diseases, malignancy, known liver diseases, and those with volume overload related to extracardiac causes. NAFLD was diagnosed by ultrasonography and exclusion of competing etiologies. The primary outcome of the study was the 1-year all-cause rehospitalization rate. Among the 107 patients enrolled in the study, the cumulative rehospitalization rate was 12.1% at 1 month, 25.2% at 3 months, 29.9% at 6 months, and 38.3% at 1 year. Patients with NAFLD had markedly higher 1-year rehospitalization rates than those without NAFLD (58% vs 21% at 1 y; P < 0.001 by the log-rank test). Cox regression analysis revealed that NAFLD was associated with a 5.5-fold increased risk of rehospitalization (adjusted hazard ratio 5.56, 95% confidence interval 2.46–12.1, P < 0.001) after adjustment for multiple HF risk factors and potential confounders. In conclusion, NAFLD was independently associated with higher 1-year rehospitalization in patients hospitalized for acute HF. PMID:26886619

  7. Fatigue History and in-situ Loading Studies of the overload Effect Using High Resolution X-ray Strain Profiling

    SciTech Connect

    Croft,M.; Jisrawi, N.; Zhong, Z.; Holtz, R.; Sadananda, K.; Skaritka, J.; Tsakalakos, T.

    2007-01-01

    High-energy synchrotron X-ray diffraction experiments are used to perform local crack plane strain profiling of 4140 steel compact tension specimens fatigued at constant amplitude, subjected to a single overload cycle, then fatigued some more at constant amplitude. X-ray strain profiling results on a series of samples employing in-situ load cycling are correlated with the crack growth rate (da/dN) providing insight into the da/dN retardation known as the 'overload effect'. Immediately after the overload, the strain under maximum load is greatly reduced but the range of strain, between zero and maximum load, remains unchanged compared to the pre-overload values. At the point of maximum retardation, it is the strain range that is greatly reduced while the maximum-load strain has begun to recover to the pre-overload value. For a sample that has recovered to approximately half of the original da/dN value following the overload, the strain at maximum load is fully recovered while the strain range, though partially recovered, is still substantially reduced. The dominance of the strain range in the overload effect is clearly indicated. Subject to some assumptions, strong quantitative support for a crack growth rate driving force of the suggested form [(K{sub max}){sup -p}({Delta}K){sup p}]{sup {gamma}} is found. A dramatic nonlinear load dependence in the spatial distribution of the strain at maximum retardation is also demonstrated: at low load the response is dominantly at the overload position; whereas at high loads it is dominantly at the crack tip position. This transfer of load response away from the crack tip to the overload position appears fundamental to the overload effect for high R-ratio fatigue as studied here.

  8. 21 CFR 890.5575 - Powered external limb overload warning device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered external limb overload warning device. 890.5575 Section 890.5575 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  9. 21 CFR 890.5575 - Powered external limb overload warning device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered external limb overload warning device. 890.5575 Section 890.5575 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  10. 21 CFR 890.5575 - Powered external limb overload warning device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered external limb overload warning device. 890.5575 Section 890.5575 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  11. 21 CFR 890.5575 - Powered external limb overload warning device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered external limb overload warning device. 890.5575 Section 890.5575 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  12. The "Tyranny of Choice": Choice Overload as a Possible Instance of Effort Discounting

    ERIC Educational Resources Information Center

    Reed, Derek D.; Reed, Florence D. DiGennaro; Chok, James; Brozyna, Gary A.

    2011-01-01

    When making a choice, people like to have options, but an emerging literature on "choice overload" suggests that the provision of too many options results in adverse experiences, including a depletion of cognitive resources and postdecision feelings of regret. A strong implication is that individuals should shy away from situations involving too…

  13. Minihepcidins prevent iron overload in a hepcidin-deficient mouse model of severe hemochromatosis.

    PubMed

    Ramos, Emilio; Ruchala, Piotr; Goodnough, Julia B; Kautz, Léon; Preza, Gloria C; Nemeth, Elizabeta; Ganz, Tomas

    2012-11-01

    The deficiency of hepcidin, the hormone that controls iron absorption and its tissue distribution, is the cause of iron overload in nearly all forms of hereditary hemochromatosis and in untransfused iron-loading anemias. In a recent study, we reported the development of minihepcidins, small drug-like hepcidin agonists. Here we explore the feasibility of using minihepcidins for the prevention and treatment of iron overload in hepcidin-deficient mice. An optimized minihepcidin (PR65) was developed that had superior potency and duration of action compared with natural hepcidin or other minihepcidins, and favorable cost of synthesis. PR65 was administered by subcutaneous injection daily for 2 weeks to iron-depleted or iron-loaded hepcidin knockout mice. PR65 administration to iron-depleted mice prevented liver iron loading, decreased heart iron levels, and caused the expected iron retention in the spleen and duodenum. At high doses, PR65 treatment also caused anemia because of profound iron restriction. PR65 administration to hepcidin knockout mice with pre-existing iron overload had a more moderate effect and caused partial redistribution of iron from the liver to the spleen. Our study demonstrates that minihepcidins could be beneficial in iron overload disorders either used alone for prevention or possibly as adjunctive therapy with phlebotomy or chelation. PMID:22990014

  14. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.506 Electric equipment...

  15. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.506 Electric equipment...

  16. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.506 Electric equipment...

  17. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.506 Electric equipment...

  18. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.506 Electric equipment...

  19. 21 CFR 890.5575 - Powered external limb overload warning device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered external limb overload warning device. 890.5575 Section 890.5575 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  20. Estimation of iron overloads using oral exfoliative cytology in beta-thalassemia major patients

    PubMed Central

    Leekha, Swati; Nayar, Amit Kumar; Bakshi, Preeti; Sharma, Aman; Parhar, Swati; Soni, Sugandhi

    2016-01-01

    Background: Iron overload is a medical condition that occurs when too much of the mineral iron builds up inside the body and produces a toxic reaction. Thalassemia is a genetic disorder of hemoglobin synthesis, which requires regular blood transfusion therapy, and the lack of specific excretory pathways for iron in humans leads to iron overload in the body tissues. It is a major cause of morbidity and mortality in these patients. The estimation of iron levels in exfoliated buccal mucosal cells may provide a simple, noninvasive, and a safe procedure for estimating the iron overload by using the Perls’ Prussian blue stain. Methods: Smears were obtained from buccal mucosa of 40 randomly selected beta-thalassemia major patients and 40 healthy subjects as controls. Smears were stained with Perls’ Prussian blue method. Blood samples were taken for estimation of serum ferritin levels. Images of smears were analyzed using the software image J software version 1.47v and correlated with serum ferritin. Results: Perls’ positivity was observed in 87.5% of thalassemic patients with a positive correlation to serum ferritin levels. Conclusion: The use of exfoliative buccal mucosal cells for the evaluation of iron overloads in the body provides us with a diagnostic medium that is noninvasive, easy to collect, store, and transport, cost effective, and above all reliable. PMID:27081394

  1. The Effects of Technological Overload on Children: An Art Therapist's Perspective

    ERIC Educational Resources Information Center

    Klorer, P. Gussie

    2009-01-01

    Children today are continually bombarded with visual and auditory stimulation, and many make their connections in cyberspace to the detriment of real-time face-to-face encounters with other people. The negative effects of multitasking and technological overload on children and adolescents are discussed in this viewpoint article from the…

  2. Minihepcidins prevent iron overload in a hepcidin-deficient mouse model of severe hemochromatosis

    PubMed Central

    Ramos, Emilio; Ruchala, Piotr; Goodnough, Julia B.; Kautz, Léon; Preza, Gloria C.; Nemeth, Elizabeta

    2012-01-01

    The deficiency of hepcidin, the hormone that controls iron absorption and its tissue distribution, is the cause of iron overload in nearly all forms of hereditary hemochromatosis and in untransfused iron-loading anemias. In a recent study, we reported the development of minihepcidins, small drug-like hepcidin agonists. Here we explore the feasibility of using minihepcidins for the prevention and treatment of iron overload in hepcidin-deficient mice. An optimized minihepcidin (PR65) was developed that had superior potency and duration of action compared with natural hepcidin or other minihepcidins, and favorable cost of synthesis. PR65 was administered by subcutaneous injection daily for 2 weeks to iron-depleted or iron-loaded hepcidin knockout mice. PR65 administration to iron-depleted mice prevented liver iron loading, decreased heart iron levels, and caused the expected iron retention in the spleen and duodenum. At high doses, PR65 treatment also caused anemia because of profound iron restriction. PR65 administration to hepcidin knockout mice with pre-existing iron overload had a more moderate effect and caused partial redistribution of iron from the liver to the spleen. Our study demonstrates that minihepcidins could be beneficial in iron overload disorders either used alone for prevention or possibly as adjunctive therapy with phlebotomy or chelation. PMID:22990014

  3. Therapeutic effect of deferoxamine on iron overload-induced inhibition of osteogenesis in a zebrafish model.

    PubMed

    Chen, Bin; Yan, Yi-Lin; Liu, Chen; Bo, Lin; Li, Guang-Fei; Wang, Han; Xu, You-Jia

    2014-03-01

    Osteoporosis results from an imbalance in bone remodeling, in which osteoclastic bone resorption exceeds osteoblastic bone formation. Iron has recently been recognized as an independent risk factor for osteoporosis. Reportedly, excess iron could promote osteoclast differentiation and bone resorption through the production of reactive oxygen species (ROS). We evaluated the effect of iron on osteoblast differentiation and bone formation in zebrafish and further investigated the potential benefits of deferoxamine (DFO), a powerful iron chelator, in iron-overloaded zebrafish. The zebrafish model of iron overload described in this study demonstrated an apparent inhibition of bone formation, accompanied by decreased expression of osteoblast-specific genes (runx2a, runx2b, osteocalcin, osteopontin, ALP, and collagen type I). The negative effect of iron on osteoblastic activity and bone formation could be attributed to increased ROS generation and oxidative stress. Most importantly, we revealed that DFO was capable of removing whole-body iron and attenuating oxidative stress in iron-overloaded larval zebrafish, which facilitated larval recovery from the reductions in bone formation and osteogenesis induced by iron overload. PMID:24414856

  4. Update on the use of deferasirox in the management of iron overload

    PubMed Central

    Taher, Ali; Cappellini, Maria Domenica

    2009-01-01

    Regular blood transfusions as supportive care for patients with chronic anemia inevitably lead to iron overload as humans cannot actively remove excess iron. The cumulative effects of iron overload cause significant morbidity and mortality if not effectively treated with chelation therapy. Based on a comprehensive clinical development program, the once-daily, oral iron chelator deferasirox (Exjade®) is approved for the treatment of transfusional iron overload in adult and pediatric patients with various transfusion-dependent anemias, including β-thalassemia and the myelodysplastic syndromes. Deferasirox dose should be titrated for each individual patient based on transfusional iron intake, current iron burden and whether the goal is to decrease or maintain body iron levels. Doses of >30 mg/kg/day have been shown to be effective with a safety profile consistent with that observed at doses <30 mg/kg/day. Recent data have highlighted the ability of deferasirox to decrease cardiac iron levels and to prevent the accumulation of iron in the heart. The long-term efficacy and safety of deferasirox for up to 5 years of treatment have now been established. The availability of this effective and generally well tolerated oral therapy represents a significant advance in the management of transfusional iron overload. PMID:19898650

  5. Monocyte-derived extracellular Nampt-dependent biosynthesis of NAD(+) protects the heart against pressure overload.

    PubMed

    Yano, Masamichi; Akazawa, Hiroshi; Oka, Toru; Yabumoto, Chizuru; Kudo-Sakamoto, Yoko; Kamo, Takehiro; Shimizu, Yu; Yagi, Hiroki; Naito, Atsuhiko T; Lee, Jong-Kook; Suzuki, Jun-ichi; Sakata, Yasushi; Komuro, Issei

    2015-01-01

    Nicotinamide phosphoribosyltransferase (Nampt) catalyzes the rate-limiting step in the salvage pathway for nicotinamide adenine dinucleotide (NAD(+)) biosynthesis, and thereby regulates the deacetylase activity of sirtuins. Here we show accommodative regulation of myocardial NAD(+) by monocyte-derived extracellular Nampt (eNampt), which is essential for hemodynamic compensation to pressure overload. Although intracellular Nampt (iNampt) expression was decreased in pressure-overloaded hearts, myocardial NAD(+) concentration and Sirt1 activity were preserved. In contrast, iNampt was up-regulated in spleen and monocytes, and circulating eNampt protein and nicotinamide mononucleotide (NMN), a key precursor of NAD(+), were significantly increased. Pharmacological inhibition of Nampt by FK866 or depletion of monocytes/macrophages by clodronate liposomes disrupted the homeostatic mechanism of myocardial NAD(+) levels and NAD(+)-dependent Sirt1 activity, leading to susceptibility to cardiomyocyte apoptosis and cardiac decompensation in pressure-overloaded mice. These biochemical and hemodynamic defects were prevented by systemic administration of NMN. Our studies uncover a crucial role of monocyte-derived eNampt in myocardial adaptation to pressure overload, and highlight a potential intervention controlling myocardial NAD(+) against heart failure. PMID:26522369

  6. 'Sorting the Wheat from the Chaff': Investigating Overload in Educational Discussion Systems

    ERIC Educational Resources Information Center

    Kear, Karen; Heap, N.W.

    2007-01-01

    This paper reports on research to investigate design features of asynchronous discussion systems for higher education. The research aims to identify features that increase the benefits of discussion systems and reduce the problems. The paper focuses on a major theme that emerged from interviews with learners and teachers: information overload.…

  7. Exploring the Influence of Information Overload on Middle Management Decision-Making in Organizations

    ERIC Educational Resources Information Center

    Carlevale, Edward A.

    2010-01-01

    This phenomenological study was an exploration of information overload and how it influenced middle management decision-making in a single organization. In-depth interviews were used to gather lived experiences of 22 middle managers at XYZ Defense Company in California. Data were analyzed using both HyperRESEARCH TM 2.8 software and a manual…

  8. When Enough Is Not Enough: Information Overload and Metacognitive Decisions to Stop Studying Information

    ERIC Educational Resources Information Center

    Murayama, Kou; Blake, Adam B.; Kerr, Tyson; Castel, Alan D.

    2016-01-01

    People are often exposed to more information than they can actually remember. Despite this frequent form of information overload, little is known about how much information people choose to remember. Using a novel "stop" paradigm, the current research examined whether and how people choose to stop receiving new--possibly…

  9. An Investigation of Data Overload in Team-Based Distributed Cognition Systems

    ERIC Educational Resources Information Center

    Hellar, David Benjamin

    2009-01-01

    The modern military command center is a hybrid system of computer automated surveillance and human oriented decision making. In these distributed cognition systems, data overload refers simultaneously to the glut of raw data processed by information technology systems and the dearth of actionable knowledge useful to human decision makers.…

  10. Why mobile health app overload drives us crazy, and how to restore the sanity

    PubMed Central

    2013-01-01

    Background Smartphones and tablet computers have become an integral part of our lives. One of their key features is the possibility of installing third-party apps. These apps can be very helpful for improving health and healthcare. However, medical professionals and citizens are currently being overloaded with health apps. Consequently, they will have difficulty with finding the right app, and information and features are fragmented over too many apps, thereby limiting their usefulness. Discussion In order to combat health app overload, suppliers of apps need to do three things. One, join the open source movement, so that a few apps can work as gateway to medical information by incorporating information from different sources. Two, standardize content, so that the information provided via apps is readable. And third, in order to prevent information overload from occurring within an app, content should be personalized towards an individual’s characteristics and context. Summary Suppliers of medical information and features need to join the open source movement and must make use of standardized medical information formats, in order to allow third parties to create valuable, mobile gateway apps. This can prevent the occurrence of health app overload. By going along in these trends, we can make health apps achieve the impact on healthcare quality and citizens’ health many of us envision. PMID:23399513

  11. Selectivity of monolithic supports under overloading conditions and their use for separation of human plasma and isolation of low abundance proteins

    PubMed Central

    Brgles, Marija; Clifton, James; Walsh, Robert; Huang, Feilei; Rucevic, Marijana; Cao, Lulu; Hixson, Douglas; Müller, Egbert

    2011-01-01

    Human serum albumin (HSA) and immunoglobulin G (IgG) represent over 75% of all proteins present in human plasma. These two proteins frequently interfere with detection, determination and purification of low abundance proteins that can be potential biomarkers and biomarker candidates for various diseases. Some low abundance plasma proteins such as clotting factors and inhibitors are also important therapeutic agents. In this paper, the characterization of ion-exchange monolithic supports under overloading conditions was performed by use of sample displacement chromatography (SDC). If these supports were used for separation of human plasma, the composition of bound and eluted proteins in both anion- and cation-exchange mode is dependent on column loading. Under overloading conditions, the weakly bound proteins such as HSA in anion-exchange and IgG in cation-exchange mode are displaced by stronger binding proteins, and this phenomenon was not dependent on column size. Consequently, small monolithic columns with a column volume of 100 and 200 μL are ideal supports for high-throughput screening in order to develop new methods for separation of complex mixtures, and for sample preparation in proteomic technology. PMID:21186030

  12. Diagnostic approaches to acute transfusion reactions.

    PubMed

    Leo, A; Pedal, I

    2010-06-01

    The erroneous transfusion of ABO-incompatible red cells may lead to life-threatening hemolysis and complement-induced shock, resulting in death in less than 10% of cases (acute hemolytic transfusion reaction, AHTR). Identification of the cause of an erroneous transfusion is accomplished in nearly all incidents merely by checking the identity of the patient, blood sample and blood bag. The erroneous transfusion is confirmed by serological and--in the case of a fatality- immunohistochemical methods. The differential diagnosis should rule out transfusion-related acute lung injury (TRALI), other immunologically triggered causes such as febrile nonhemolytic transfusion reaction (FNHTR) or allergic reactions, but also nonimmunological causes such as bacterial contamination of the blood components, transfusion-associated circulatory overload (TACO) and other rare events such as citrate overload or embolism (by air or debris). In the case of a fatality, evaluation of a patient's medical records, serological and microbiological analyses, autopsy and histology, taken together, clarify questions of causality. PMID:20140541

  13. Ultrasound Changes in Achilles Tendon and Gastrocnemius Medialis Muscle on Squat Eccentric Overload and Running Performance.

    PubMed

    Sanz-López, Fernando; Berzosa Sánchez, César; Hita-Contreras, Fidel; Cruz-Diaz, David; Martínez-Amat, Antonio

    2016-07-01

    Sanz-López, F, Berzosa Sánchez, C, Hita-Contreras, F, Cruz-Diaz, D, and Martínez-Amat, A. Ultrasound changes in Achilles tendon and gastrocnemius medialis muscle on squat eccentric overload and running performance. J Strength Cond Res XX(X): 000-000, 2015-Previous studies have proven the adaptation to load in the Achilles tendon and gastrocnemius muscle after different types of exercise, such as running, heel drop training, and a variety of sports. These findings have been applied to improve performance and in the treatment and prevention of overuse injuries. However, the effects that squat performance may have on the Achilles tendon and gastrocnemius muscle are still unknown. Squats are a widely used training exercise that involves calf-muscle activation. Similarly, no reports have been published regarding the adaptation to load of trained and untrained subjects during several consecutive days of running. The purpose of this study was to analyze changes in the Achilles tendon and in the pennation angles of the gastrocnemius medialis after eccentric overload training and within 3 days of running. Twenty healthy males who volunteered for this study were divided into 2 groups. Subjects in the eccentric overload training (ECC) group performed 6 weeks of eccentric overload training (twice weekly, 4 sets of 7 repetitions in a Yoyo squat device) before the running intervention. All participants, ECC and control (CONT) groups, ran on 3 consecutive days. After the eccentric training, an increase in the cross-sectional area of the Achilles tendon and in the pennation angle was observed. As for the running intervention, the behavior of tissues in both groups was similar. These results suggest that eccentric overload training with squats promotes changes in the Achilles tendon and in the pennation angle of the gastrocnemius medialis muscle. Nevertheless, significant changes in the tissue do not appear between the running performance of trained and untrained subjects. PMID

  14. Effects of iron and copper overload on the human liver: an ultrastructural study.

    PubMed

    Fanni, D; Fanos, V; Gerosa, C; Piras, M; Dessi, A; Atzei, A; Van, Eyken P; Gibo, Y; Faa, G

    2014-01-01

    Iron and copper ions play important roles in many physiological functions of our body, even though the exact mechanisms regulating their absorption, distribution and excretion are not fully understood. Metal-related human pathology may be observed in two different clinical settings: deficiency or overload. The overload in liver cells of both trace elements leads to multiple cellular lesions. Here we report the main pathological changes observed at transmission electron microscopy in the liver of subjects affected by Beta-thalassemia and by Wilson's disease. The hepatic iron overload in beta-thalassemia patients is associated with haemosiderin storage both in Kupffer cells and in the cytoplasm of hepatocytes. Haemosiderin granules are grouped inside voluminous lysosomes, also called siderosomes. Other ultrastructural changes are fat droplets, proliferation of the smooth endoplasmic reticulum and fibrosis. Apoptosis of hepatocytes and infiltration of sinusoids by polymorphonucleates is also detected in beta-thalassemia. Ultrastructural changes in liver biopsies from Wilson's disease patients are characterized by severe mitochondrial changes, associated with an increased number of perossisomes, cytoplasmic lipid droplets and the presence of lipolysosomes, characteristic cytoplasmic bodies formed by lipid vacuoles surrounded by electron-dense lysosomes. In patients affected by Wilson's disease, nuclei are frequently involved, with disorganization of the nucleoplasm and with glycogen inclusions. On the contrary, no significant changes are detected in Kupffer cells. Our data show that iron and copper, even though are both transition metals, are responsible of different pathological changes at ultrastructural level. In particular, copper overload is associated with mitochondrial damage, whereas iron overload only rarely may cause severe mitochondrial changes. These differences underlay the need for further studies in which biochemical analyses should be associated with

  15. Iatrogenic Iron Overload in Dialysis Patients at the Beginning of the 21st Century.

    PubMed

    Rostoker, Guy; Vaziri, Nosratola D; Fishbane, Steven

    2016-05-01

    Iron overload used to be considered rare in hemodialysis patients but its clinical frequency is now increasingly realized. The liver is the main site of iron storage and the liver iron concentration (LIC) is closely correlated with total iron stores in patients with secondary hemosideroses and genetic hemochromatosis. Magnetic resonance imaging is now the gold standard method for LIC estimation and monitoring in non-renal patients. Studies of LIC in hemodialysis patients by quantitative magnetic resonance imaging and magnetic susceptometry have demonstrated a strong relation between the risk of iron overload and the use of intravenous (IV) iron products prescribed at doses determined by the iron biomarker cutoffs contained in current anemia management guidelines. These findings have challenged the validity of both iron biomarker cutoffs and current clinical guidelines, especially with respect to recommended IV iron doses. Three long-term observational studies have recently suggested that excessive IV iron doses may be associated with an increased risk of cardiovascular events and death in hemodialysis patients. We postulate that iatrogenic iron overload in the era of erythropoiesis-stimulating agents may silently increase complications in dialysis patients without creating frank clinical signs and symptoms. High hepcidin-25 levels were recently linked to fatal and nonfatal cardiovascular events in dialysis patients. It is therefore tempting to postulate that the main pathophysiological pathway leading to these events may involve the pleiotropic master hormone hepcidin (synergized by fibroblast growth factor 23), which regulates iron metabolism. Oxidative stress as a result of IV iron infusions and iron overload, by releasing labile non-transferrin-bound iron, might represent a 'second hit' on the vascular bed. Finally, iron deposition in the myocardium of patients with severe iron overload might also play a role in the pathogenesis of sudden death in some patients

  16. LRRC10 is required to maintain cardiac function in response to pressure overload.

    PubMed

    Brody, Matthew J; Feng, Li; Grimes, Adrian C; Hacker, Timothy A; Olson, Timothy M; Kamp, Timothy J; Balijepalli, Ravi C; Lee, Youngsook

    2016-01-15

    We previously reported that the cardiomyocyte-specific leucine-rich repeat containing protein (LRRC)10 has critical functions in the mammalian heart. In the present study, we tested the role of LRRC10 in the response of the heart to biomechanical stress by performing transverse aortic constriction on Lrrc10-null (Lrrc10(-/-)) mice. Mild pressure overload induced severe cardiac dysfunction and ventricular dilation in Lrrc10(-/-) mice compared with control mice. In addition to dilation and cardiomyopathy, Lrrc10(-/-) mice showed a pronounced increase in heart weight with pressure overload stimulation and a more dramatic loss of cardiac ventricular performance, collectively suggesting that the absence of LRRC10 renders the heart more disease prone with greater hypertrophy and structural remodeling, although rates of cardiac fibrosis and myocyte dropout were not different from control mice. Lrrc10(-/-) cardiomyocytes also exhibited reduced contractility in response to β-adrenergic stimulation, consistent with loss of cardiac ventricular performance after pressure overload. We have previously shown that LRRC10 interacts with actin in the heart. Here, we show that His(150) of LRRC10 was required for an interaction with actin, and this interaction was reduced after pressure overload, suggesting an integral role for LRRC10 in the response of the heart to mechanical stress. Importantly, these experiments demonstrated that LRRC10 is required to maintain cardiac performance in response to pressure overload and suggest that dysregulated expression or mutation of LRRC10 may greatly sensitize human patients to more severe cardiac disease in conditions such as chronic hypertension or aortic stenosis. PMID:26608339

  17. Transient two-phase CFD simulation of overload pressure pulsation in a prototype sized Francis turbine considering the waterway dynamics

    NASA Astrophysics Data System (ADS)

    Mössinger, P.; Conrad, P.; Jung, A.

    2014-03-01

    At high load operation points, Francis turbines generally produce large cavitation volumes of central vortex character in the draft tube. In order to gain a deeper understanding of the flow behaviour at high load conditions a combined 1D-3D transient two-phase numerical investigation at prototype size was carried out and these results were compared with measured site data. A one-dimensional model to capture hydroacoustic effects along a pipeline will be presented. The corresponding PDEs were solved using an implicit finite difference scheme on a staggered grid. In contrast to previous studies this model is coupled to the commercial software ANSYS CFX through an interface which exchanges pressure and discharge data within every time step until convergence. Results of the one-dimensional approach as well as the coupled solution were validated with commercial one-dimensional software (SIMSEN) and a full threedimensional calculation for hydroacoustic test cases. Unlike former investigations the described 1D-3D approach is used to compare site data with a numerical analysis at prototype size focused on the amplitude and frequency of the pressure pulsation at overload condition. The combined model is able to capture the occurring phase change in the draft tube as well as the propagating pressure oscillation through the hydraulic system without solving for the whole penstock in a 3D manner, thus saving time and computational resources.

  18. Acute respiratory distress syndrome following cardiovascular surgery: current concepts and novel therapeutic approaches

    PubMed Central

    Hoegl, Sandra; Zwissler, Bernhard; Eltzschig, Holger K.; Vohwinkel, Christine

    2015-01-01

    Purpose of review This review gives an update on current treatment options and novel concepts on the prevention and treatment of the acute respiratory distress syndrome (ARDS) in cardiovascular surgery patients. Recent findings The only proven beneficial therapeutic options in ARDS are those that help to prevent further ventilator-induced lung injury, such as prone position, use of lung-protective ventilation strategies, and extracorporeal membrane oxygenation. In the future also new approaches like mesenchymal cell therapy, activation of hypoxia-elicited transcription factors or targeting of purinergic signaling may be successful outside the experimental setting. Owing to the so far limited treatment options, it is of great importance to determine patients at risk for developing ARDS already perioperatively. In this context, serum biomarkers and lung injury prediction scores could be useful. Summary Preventing ARDS as a severe complication in the cardiovascular surgery setting may help to reduce morbidity and mortality. As cardiovascular surgery patients are of greater risk to develop ARDS, preventive interventions should be implemented early on. Especially, use of low tidal volumes, avoiding of fluid overload and restrictive blood transfusion regimes may help to prevent ARDS. PMID:26598954

  19. Time course of the MAPK and PI3-kinase response within 24 h of skeletal muscle overload

    NASA Technical Reports Server (NTRS)

    Carlson, C. J.; Fan, Z.; Gordon, S. E.; Booth, F. W.

    2001-01-01

    Knowledge of the molecular mechanisms by which skeletal muscle hypertrophies in response to increased mechanical loading may lead to the discovery of novel treatment strategies for muscle wasting and frailty. To gain insight into potential early signaling mechanisms associated with skeletal muscle hypertrophy, the temporal pattern of mitogen-activated protein kinase (MAPK) phosphorylation and phosphatidylinositol 3-kinase (PI3-kinase) activity during the first 24 h of muscle overload was determined in the rat slow-twitch soleus and fast-twitch plantaris muscles after ablation of the gastrocnemius muscle. p38alpha MAPK phosphorylation was elevated for the entire 24-h overload period in both muscles. In contrast, Erk 2 and p54 JNK phosphorylation were transiently increased by overload, returning to the levels of sham-operated controls by 24 h. PI3-kinase activity was increased by muscle overload only at 12 h of overload and only in the plantaris muscle. In summary, sustained elevation of p38alpha MAPK phosphorylation occurred early in response to muscle overload, identifying this pathway as a potential candidate for mediating early hypertrophic signals in response to skeletal muscle overload.

  20. ROS-mediated iron overload injures the hematopoiesis of bone marrow by damaging hematopoietic stem/progenitor cells in mice.

    PubMed

    Chai, Xiao; Li, Deguan; Cao, Xiaoli; Zhang, Yuchen; Mu, Juan; Lu, Wenyi; Xiao, Xia; Li, Chengcheng; Meng, Juanxia; Chen, Jie; Li, Qing; Wang, Jishi; Meng, Aimin; Zhao, Mingfeng

    2015-01-01

    Iron overload, caused by hereditary hemochromatosis or repeated blood transfusions in some diseases, such as beta thalassemia, bone marrow failure and myelodysplastic syndrome, can significantly induce injured bone marrow (BM) function as well as parenchyma organ dysfunctions. However, the effect of iron overload and its mechanism remain elusive. In this study, we investigated the effects of iron overload on the hematopoietic stem and progenitor cells (HSPCs) from a mouse model. Our results showed that iron overload markedly decreased the ratio and clonogenic function of murine HSPCs by the elevation of reactive oxygen species (ROS). This finding is supported by the results of NAC or DFX treatment, which reduced ROS level by inhibiting NOX4 and p38MAPK and improved the long-term and multi-lineage engrafment of iron overload HSCs after transplantation. Therefore, all of these data demonstrate that iron overload injures the hematopoiesis of BM by enhancing ROS through NOX4 and p38MAPK. This will be helpful for the treatment of iron overload in patients with hematopoietic dysfunction. PMID:25970748

  1. Employees' Perceptions of Email Communication, Volume and Management Strategies in an Australian University

    ERIC Educational Resources Information Center

    Pignata, Silvia; Lushington, Kurt; Sloan, Jeremy; Buchanan, Fiona

    2015-01-01

    Despite email playing a central role in university business, little is known about the strategies used by staff to manage email and the factors contributing to email overload. In a mixed method study undertaken in one Australian university comparing academic (n = 193) and professional (n = 278) staff, we found that while email volume was higher in…

  2. B-type natriuretic peptide-directed ultrafiltration improves care in acutely hospitalized dialysis patients.

    PubMed

    Tapolyai, Mihály; Uysal, Aşkin; Maeweathers, Gail; Bahta, Elias; Dossabhoy, Neville R

    2009-01-01

    In an observational study in 19 consecutive acutely hospitalized dialysis patients, ultrafiltration (UF) volume was determined by B-type natriuretic peptide (BNP) levels. Patients were ultrafiltrated daily until they achieved a target BNP level <500 pg/mL. The UF volumes ranged from 2 to 5 L per session. All patients were male veterans aged 68+/-11 years (mean +/- SD), 74% were diabetic, 47% were African Americans, 58% underwent prevalent dialysis, and 53% had an arteriovenous fistula. Left ventricular ejection fraction on 2-dimensional echocardiography was 43.8%+/-27.9% (n=16). The admission BNP was 2412+/-1479 pg/mL (range, 561-5000 pg/mL) and BNP at hospital discharge was 1245+/-1173 pg/mL (range, 345-5000 pg/mL) (nonparametric Wilcoxon P=.0013). Admission weight was 88.9+/-27.9 kg and at discharge was 78.1+/-25.6 kg (P=.0002). The number of antihypertensive medications taken was 3.8+/-2.0 at admission and 2.3+/-1.7 at discharge (P=.0005). The number of patients with >2 blood pressure medications decreased from 14 to 6 (Fisher exact test, P=.02). The systolic/diastolic/mean arterial blood pressure decreased from admission to discharge (153.6+/-43.8/80.6+/-21.8/102.4+/-27.3 to 132.1+/-27.9/68.9+/-14.6/89.9+/-16.5 mm Hg; P=.0222/.0139/.0329, respectively). Although all patients were volume-overloaded at admission according to BNP criteria (>500), only 42% were identified as having heart failure. BNP-directed UF is safe because it minimizes symptomatic hypotension, identifies occult congestive heart failure in a large number of patients, and significantly reduces blood pressure in addition to reducing body weight and number of medications used. PMID:19522962

  3. Impact of iron overload on interleukin-10 levels, biochemical parameters and oxidative stress in patients with sickle cell anemia

    PubMed Central

    Barbosa, Maritza Cavalcante; dos Santos, Talyta Ellen Jesus; de Souza, Geane Félix; de Assis, Lívia Coêlho; Freitas, Max Victor Carioca; Gonçalves, Romélia Pinheiro

    2013-01-01

    Objective The aim of this study was to evaluate the impact of iron overload on the profile of interleukin-10 levels, biochemical parameters and oxidative stress in sickle cell anemia patients. Methods A cross-sectional study was performed of 30 patients with molecular diagnosis of sickle cell anemia. Patients were stratified into two groups, according to the presence of iron overload: Iron overload (n = 15) and Non-iron overload (n = 15). Biochemical analyses were performed utilizing the Wiener CM 200 automatic analyzer. The interleukin-10 level was measured by capture ELISA using the BD OptEIAT commercial kit. Oxidative stress parameters were determined by spectrophotometry. Statistical analysis was performed using GraphPad Prism software (version 5.0) and statistical significance was established for p-values < 0.05 in all analyses. Results Biochemical analysis revealed significant elevations in the levels of uric acid, triglycerides, very low-density lipoprotein (VLDL), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), urea and creatinine in the Iron overload Group compared to the Non-iron overload Group and significant decreases in the high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Ferritin levels correlated positively with uric acid concentrations (p-value < 0.05). The Iron overload Group showed lower interleukin-10 levels and catalase activity and higher nitrite and malondialdehyde levels compared with the Non-iron overload Group. Conclusion The results of this study are important to develop further consistent studies that evaluate the effect of iron overload on the inflammatory profile and oxidative stress of patients with sickle cell anemia. PMID:23580881

  4. Curcumin Attenuates Iron Accumulation and Oxidative Stress in the Liver and Spleen of Chronic Iron-Overloaded Rats

    PubMed Central

    Badria, Farid A.; Ibrahim, Ahmed S.; Badria, Adel F.; Elmarakby, Ahmed A.

    2015-01-01

    Objectives Iron overload is now recognized as a health problem in industrialized countries, as excessive iron is highly toxic for liver and spleen. The potential use of curcumin as an iron chelator has not been clearly identified experimentally in iron overload condition. Here, we evaluate the efficacy of curcumin to alleviate iron overload-induced hepatic and splenic abnormalities and to gain insight into the underlying mechanisms. Design and Methods Three groups of male adult rats were treated as follows: control rats, rats treated with iron in a drinking water for 2 months followed by either vehicle or curcumin treatment for 2 more months. Thereafter, we studied the effects of curcumin on iron overload-induced lipid peroxidation and anti-oxidant depletion. Results Treatment of iron-overloaded rats with curcumin resulted in marked decreases in iron accumulation within liver and spleen. Iron-overloaded rats had significant increases in malonyldialdehyde (MDA), a marker of lipid peroxidation and nitric oxide (NO) in liver and spleen when compared to control group. The effects of iron overload on lipid peroxidation and NO levels were significantly reduced by the intervention treatment with curcumin (P<0.05). Furthermore, the endogenous anti-oxidant activities/levels in liver and spleen were also significantly decreased in chronic iron overload and administration of curcumin restored the decrease in the hepatic and splenic antioxidant activities/levels. Conclusion Our study suggests that curcumin may represent a new horizon in managing iron overload-induced toxicity as well as in pathological diseases characterized by hepatic iron accumulation such as thalassemia, sickle cell anemia, and myelodysplastic syndromes possibly via iron chelation, reduced oxidative stress derived lipid peroxidation and improving the body endogenous antioxidant defense mechanism. PMID:26230491

  5. The Overexpression of Twinkle Helicase Ameliorates the Progression of Cardiac Fibrosis and Heart Failure in Pressure Overload Model in Mice

    PubMed Central

    Tanaka, Atsushi; Ide, Tomomi; Fujino, Takeo; Onitsuka, Ken; Ikeda, Masataka; Takehara, Takako; Hata, Yuko; Ylikallio, Emil; Tyynismaa, Henna; Suomalainen, Anu; Sunagawa, Kenji

    2013-01-01

    Myocardial mitochondrial DNA (mtDNA) copy number decreases in heart failure. In post-myocardial infarction mice, increasing mtDNA copy number by overexpressing mitochondrial transcription factor attenuates mtDNA deficiency and ameliorates pathological remodeling thereby markedly improving survival. However, the functional significance of increased mtDNA copy number in hypertensive heart disease remains unknown. We addressed this question using transgenic mice that overexpress Twinkle helicase (Twinkle; Tg), the mtDNA helicase, and examined whether Twinkle overexpression protects the heart from left ventricular (LV) remodeling and failure after pressure overload created by transverse aortic constriction (TAC). Twinkle overexpression increased mtDNA copy number by 2.2±0.1-fold. Heart weight, LV diastolic volume and wall thickness were comparable between Tg and wild type littermates (WT) at 28 days after TAC operation. LV end-diastolic pressure increased in WT after TAC (8.6±2.8 mmHg), and this increase was attenuated in Tg (4.6±2.6 mmHg). Impaired LV fractional shortening after TAC operation was also suppressed in Tg, as measured by echocardiography (WT: 16.2±7.2% vs Tg: 20.7±6.2%). These LV functional improvements were accompanied by a decrease in interstitial fibrosis (WT: 10.6±1.1% vs Tg: 3.0±0.6%). In in vitro studies, overexpressing Twinkle using an adenovirus vector in cultured cardiac fibroblasts significantly suppressed mRNA of collagen 1a, collagen 3a and connective tissue growth factor, and angiotensin II-induced transforming growth factor β1 expression. The findings suggest that Twinkle overexpression prevents LV function deterioration. In conclusion, Twinkle overexpression increases mtDNA copy number and ameliorates the progression of LV fibrosis and heart failure in a mouse pressure overload model. Increasing mtDNA copy number by Twinkle overexpression could be a novel therapeutic strategy for hypertensive heart disease. PMID:23840758

  6. Acute nephritic syndrome

    MedlinePlus

    Glomerulonephritis - acute; Acute glomerulonephritis; Nephritis syndrome - acute ... Acute nephritic syndrome is often caused by an immune response triggered by an infection or other disease. Common causes ...

  7. Maintenance of myonuclear domain size in rat soleus after overload and growth hormone/IGF-I treatment

    NASA Technical Reports Server (NTRS)

    McCall, G. E.; Allen, D. L.; Linderman, J. K.; Grindeland, R. E.; Roy, R. R.; Mukku, V. R.; Edgerton, V. R.

    1998-01-01

    The purpose of this study was to determine the effects of functional overload (FO) combined with growth hormone/insulin-like growth factor I (GH/IGF-I) administration on myonuclear number and domain size in rat soleus muscle fibers. Adult female rats underwent bilateral ablation of the plantaris and gastrocnemius muscles and, after 7 days of recovery, were injected three times daily for 14 days with GH/IGF-I (1 mg/kg each; FO + GH/IGF-I group) or saline vehicle (FO group). Intact rats receiving saline vehicle served as controls (Con group). Muscle wet weight was 32% greater in the FO than in the Con group: 162 +/- 8 vs. 123 +/- 16 mg. Muscle weight in the FO + GH/IGF-I group (196 +/- 14 mg) was 59 and 21% larger than in the Con and FO groups, respectively. Mean soleus fiber cross-sectional area of the FO + GH/IGF-I group (2,826 +/- 445 microm2) was increased compared with the Con (2,044 +/- 108 microm2) and FO (2,267 +/- 301 microm2) groups. The difference in fiber size between the FO and Con groups was not significant. Mean myonuclear number increased in FO (187 +/- 15 myonuclei/mm) and FO + GH/IGF-I (217 +/- 23 myonuclei/mm) rats compared with Con (155 +/- 12 myonuclei/mm) rats, although the difference between FO and FO + GH/IGF-I animals was not significant. The mean cytoplasmic volume per myonucleus (myonuclear domain) was similar across groups. These results demonstrate that the larger mean muscle weight and fiber cross-sectional area occurred when FO was combined with GH/IGF-I administration and that myonuclear number increased concomitantly with fiber volume. Thus there appears to be some mechanism(s) that maintains the myonuclear domain when a fiber hypertrophies.

  8. Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers

    PubMed Central

    Concha, Claudia; Carretta, María Daniella; Alarcón, Pablo; Conejeros, Ivan; Gallardo, Diego; Hidalgo, Alejandra Isabel; Tadich, Nestor; Cáceres, Dante Daniel; Hidalgo, María Angélica

    2014-01-01

    Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response. PMID:25013355

  9. Oxidation of RyR2 Has a Biphasic Effect on the Threshold for Store Overload-Induced Calcium Release.

    PubMed

    Waddell, Helen M M; Zhang, Joe Z; Hoeksema, Katie J; McLachlan, Julia J; McLay, Janet C; Jones, Peter P

    2016-06-01

    At the single-channel level, oxidation of the cardiac ryanodine receptor (RyR2) is known to activate and inhibit the channel depending on the level of oxidation. However, the mechanisms through which these changes alter the activity of RyR2 in a cellular setting are poorly understood. In this study, we determined the effect of oxidation on a common form of RyR2 regulation; store overload-induced Ca(2+) release (SOICR). We found that oxidation resulted in concentration and time-dependent changes in the activation threshold for SOICR. Low concentrations of the oxidant H2O2 resulted in a decrease in the threshold for SOICR, which led to an increase in SOICR events. However, higher concentrations of H2O2, or prolonged exposure, reversed these changes and led to an increase in the threshold for SOICR. This increase in the threshold for SOICR in most cells was to such an extent that it led to the complete inhibition of SOICR. Acute exposure to high concentrations of H2O2 led to an initial decrease and then increase in the threshold for SOICR. In the majority of cells the increased threshold could not be reversed by the application of the reducing agent dithiothreitol. Therefore, our data suggest that low levels of RyR2 oxidation increase the channel activity by decreasing the threshold for SOICR, whereas high levels of RyR2 oxidation irreversibly increase the threshold for SOICR leading to an inhibition of RyR2. Combined, this indicates that oxidation regulates RyR2 by the same mechanism as phosphorylation, methylxanthines, and mutations, via changes in the threshold for SOICR. PMID:27276257

  10. Overload and work-family conflict among Australian dual-career families: moderating effects of support.

    PubMed

    Elloy, David F; Mackie, Beth

    2002-12-01

    Individuals in dual-career situations have become increasingly common all over the world. For couples dealing with multiple demands, this lifestyle often generates stresses and strains at home and at work, which can have negative consequences for organizations. Most empirical research into this lifestyle has been conducted in the United States and Britain, and very little in Australia. This particular study, based on data from an Australian sample of 65 dual-career couples, analyzed the relation between overload and work-family conflict and the moderating effects of support (supervisor, coworkers, and friends). Results confirm that overload was significantly related to work-family conflict but no moderating effects were found for support. Limitations of the study and an organizational role in managing the work-family interface dual-career couples are discussed. PMID:12530741

  11. Slack and overload rope protection system. Open file report, 28 Mar 79-15 Jan 83

    SciTech Connect

    Farley, H.L.; Fish, R.B.; Jeffcoat, R.L.; Hoadley, D.L.

    1983-01-01

    This report describes the development of an electronic system that detects unsafe slack and overload conditions in underground mine hoist ropes. The slack and overload rope protection system (SORPS) includes a fail-safe load cell inserted between the rope and the conveyance, and an accelerometer mounted on the conveyance. Signals from these transducers are telemetered via a radio link to the hoist control room, where they are combined with drum speed and chair status in a microprocessor-based decision and display unit. Abnormally high external force levels are detected as discrepancies between rope tension and cage acceleration; conveyance weight is inferred continuously. Hazardous conditions are displayed to the hoist operator, along with general hoist status.

  12. Aviation noise overload in the immediate proximity of the Warsaw-Okecie airport

    NASA Astrophysics Data System (ADS)

    Koszarny, Z.; Maziarka, S.

    1981-05-01

    The results are presented for investigations on noise overload around the Warszawa-Okecie airport on persons inhabiting the area where it exceeds 100 dB for a single aircraft flight. Of 256 subjects, 91.1 percent complained about aircraft noise overload. In the population studied considerable differences were noted respecting the subjective sensitivity scale. Statistical analysis showed numerous correlations between the individual noise sensitivity threshold and the subject's state of health, age, sex, type of work, etc. At the same time investigations demonstrated various forms and levels of disturbance in the organism for individual subjects and groups. The most frequent complaint was chronic fatigue (68.1 percent), followed by nervousness (36.6 percent), frequent headaches (36.2 percent), hearing disturbances (30.0 percent) and sleep disorders (23.9 percent).

  13. Fluid as a Drug: Balancing Resuscitation and Fluid Overload in the Intensive Care Setting.

    PubMed

    McGuire, Matthew D; Heung, Michael

    2016-05-01

    Intravenous fluid resuscitation is ubiquitous throughout medicine and is often considered a benign procedure. Yet, there is now clear recognition of the potential harms of fluid overload after initial resuscitation. In recent years, there has also been an increasing focus on comparing various resuscitation fluids with respect to both benefits and risks. Studies have examined colloids, such as albumin and starches, against the clinical standard of crystalloids. In addition, evidence has emerged to suggest that outcomes may be different between resuscitation with chloride-rich vs balanced crystalloid solutions. In this article, we review the current literature regarding choice of intravenous fluids for resuscitation in the intensive care setting and describe the dangers associated with fluid overload in critically ill patients. PMID:27113691

  14. Aviation noise overload in the immediate proximity of the Warsaw-Okecie airport

    NASA Technical Reports Server (NTRS)

    Koszarny, Z.; Maziarka, S.

    1981-01-01

    The results are presented for investigations on noise overload around the Warszawa-Okecie airport on persons inhabiting the area where it exceeds 100 dB for a single aircraft flight. Of 256 subjects, 91.1 percent complained about aircraft noise overload. In the population studied considerable differences were noted respecting the subjective sensitivity scale. Statistical analysis showed numerous correlations between the individual noise sensitivity threshold and the subject's state of health, age, sex, type of work, etc. At the same time investigations demonstrated various forms and levels of disturbance in the organism for individual subjects and groups. The most frequent complaint was chronic fatigue (68.1 percent), followed by nervousness (36.6 percent), frequent headaches (36.2 percent), hearing disturbances (30.0 percent) and sleep disorders (23.9 percent).

  15. Markers for vulnerability in acute porphyria. A hypothesis paper.

    PubMed

    Thunell, S; Andersson, C; Carlmark, B; Floderus, Y; Grönqvist, S O; Harper, P; Henrichson, A; Lindh, U

    1995-04-01

    Previously symptomatic and permanently asymptomatic carriers of a gene mutation for acute intermittent porphyria as well as matched controls were screened with regard to a series of variables of possible relevance to the development of porphyric symptoms. The basis for the study was a concept of acute porphyria as a condition of a permanent system overload of oxidative stress, with long term effects on hepatic and renal tissue, and with instances of periodic overload of free radicals giving rise to acute neurologic involvement. Leukocyte concentrations of manganese, calcium, iron and zinc, as well as erythrocyte calcium differed between the groups, acute intermittent porphyria gene carriers, irrespective of previous porphyric illness, showing significantly higher levels than the controls. Manganese was found to be the most discriminative component of all the 78 variables investigated, accounting for about 98 per cent of the variance between the groups. An increment, by a factor of four, in cellular manganese is suggestive of an increase, in acute intermittent porphyria, of a manganese associated enzyme, e.g. glutamine synthetase, pyruvate carboxylase or mitochondrial superoxide dismutase. The best fit into the model considered is provided by a theory focused on superoxide dismutase, induced in response to superoxide anion radical produced from aminolaevulinic acid. In porphyria gene carriers seemingly resistant to porphyric manifestations, an increase in potentially prooxidant cellular iron is matched by a proportional increment in manganese, i.e. presumably by a corresponding mitochondrial superoxide dismutase induction. This mechanism is not operative in porphyric individuals prone to development of neuropsychiatric symptoms. In acute intermittent porphyria with a history of porphyric illness there is a positive correlation between erythrocyte manganese and serum folate and a negative correlation between leukocyte ferrochelatase activity and serum cobalamin

  16. Prognostic impact of pre-transplantation transfusion history and secondary iron overload in patients with myelodysplastic syndrome undergoing allogeneic stem cell transplantation: a GITMO study

    PubMed Central

    Alessandrino, Emilio Paolo; Porta, Matteo Giovanni Della; Bacigalupo, Andrea; Malcovati, Luca; Angelucci, Emanuele; Van Lint, Maria Teresa; Falda, Michele; Onida, Francesco; Bernardi, Massimo; Guidi, Stefano; Lucarelli, Barbarella; Rambaldi, Alessandro; Cerretti, Raffaella; Marenco, Paola; Pioltelli, Pietro; Pascutto, Cristiana; Oneto, Rosi; Pirolini, Laura; Fanin, Renato; Bosi, Alberto

    2010-01-01

    Background Transfusion-dependency affects the natural history of myelodysplastic syndromes. Secondary iron overload may concur to this effect. The relative impact of these factors on the outcome of patients with myelodysplastic syndrome receiving allogeneic stem-cell transplantation remains to be clarified. Design and Methods We retrospectively evaluated the prognostic effect of transfusion history and iron overload on the post-transplantation outcome of 357 patients with myelodysplastic syndrome reported to the Gruppo Italiano Trapianto di Midollo Osseo (GITMO) registry between 1997 and 2007. Results Transfusion-dependency was independently associated with reduced overall survival (hazard ratio=1.48, P=0.017) and increased non-relapse mortality (hazard ratio=1.68, P=0.024). The impact of transfusion-dependency was noted only in patients receiving myeloablative conditioning (overall survival: hazard ratio=1.76, P=0.003; non-relapse mortality: hazard ratio=1.70, P=0.02). There was an inverse relationship between transfusion burden and overall survival after transplantation (P=0.022); the outcome was significantly worse in subjects receiving more than 20 red cell units. In multivariate analysis, transfusion-dependency was found to be a risk factor for acute graft-versus-host disease (P=0.04). Among transfusion-dependent patients undergoing myeloablative allogeneic stem cell transplantation, pre-transplantation serum ferritin level had a significant effect on overall survival (P=0.01) and non-relapse mortality (P=0.03). This effect was maintained after adjusting for transfusion burden and duration, suggesting that the negative effect of transfusion history on outcome might be determined at least in part by iron overload. Conclusions Pre-transplantation transfusion history and serum ferritin have significant prognostic value in patients with myelodysplastic syndrome undergoing myeloablative allogeneic stem cell transplantation, inducing a significant increase of non

  17. Antagonism of the thromboxane-prostanoid receptor is cardioprotective against right ventricular pressure overload

    PubMed Central

    Voss, Bryan M.; Pavliv, Leo; de Caestecker, Mark; Hemnes, Anna R.; Carrier, Erica J.

    2016-01-01

    Abstract Right ventricular (RV) failure is the primary cause of death in pulmonary arterial hypertension (PAH) and is a significant cause of morbidity and mortality in other forms of pulmonary hypertension. There are no approved therapies directed at preserving RV function. F-series and E-series isoprostanes are increased in heart failure and PAH, correlate to the severity of disease, and can signal through the thromboxane-prostanoid (TP) receptor, with effects from vasoconstriction to fibrosis. The goal of these studies was to determine whether blockade of the TP receptor with the antagonist CPI211 was beneficial therapeutically in PAH-induced RV dysfunction. Mice with RV dysfunction due to pressure overload by pulmonary artery banding (PAB) were given vehicle or CPI211. Two weeks after PAB, CPI211-treated mice were protected from fibrosis with pressure overload. Gene expression arrays and immunoblotting, quantitative histology and morphometry, and flow cytometric analysis were used to determine the mechanism of CPI211 protection. TP receptor inhibition caused a near normalization of fibrotic area, prevented cellular hypertrophy while allowing increased RV mass, increased expression of antifibrotic thrombospondin-4, and blocked induction of the profibrotic transforming growth factor β (TGF-β) pathway. A thromboxane synthase inhibitor or low-dose aspirin failed to replicate these results, which suggests that a ligand other than thromboxane mediates fibrosis through the TP receptor after pressure overload. This study suggests that TP receptor antagonism may improve RV adaptation in situations of pressure overload by decreasing fibrosis and TGF-β signaling. PMID:27252848

  18. Antagonism of the thromboxane-prostanoid receptor is cardioprotective against right ventricular pressure overload.

    PubMed

    West, James D; Voss, Bryan M; Pavliv, Leo; de Caestecker, Mark; Hemnes, Anna R; Carrier, Erica J

    2016-06-01

    Right ventricular (RV) failure is the primary cause of death in pulmonary arterial hypertension (PAH) and is a significant cause of morbidity and mortality in other forms of pulmonary hypertension. There are no approved therapies directed at preserving RV function. F-series and E-series isoprostanes are increased in heart failure and PAH, correlate to the severity of disease, and can signal through the thromboxane-prostanoid (TP) receptor, with effects from vasoconstriction to fibrosis. The goal of these studies was to determine whether blockade of the TP receptor with the antagonist CPI211 was beneficial therapeutically in PAH-induced RV dysfunction. Mice with RV dysfunction due to pressure overload by pulmonary artery banding (PAB) were given vehicle or CPI211. Two weeks after PAB, CPI211-treated mice were protected from fibrosis with pressure overload. Gene expression arrays and immunoblotting, quantitative histology and morphometry, and flow cytometric analysis were used to determine the mechanism of CPI211 protection. TP receptor inhibition caused a near normalization of fibrotic area, prevented cellular hypertrophy while allowing increased RV mass, increased expression of antifibrotic thrombospondin-4, and blocked induction of the profibrotic transforming growth factor β (TGF-β) pathway. A thromboxane synthase inhibitor or low-dose aspirin failed to replicate these results, which suggests that a ligand other than thromboxane mediates fibrosis through the TP receptor after pressure overload. This study suggests that TP receptor antagonism may improve RV adaptation in situations of pressure overload by decreasing fibrosis and TGF-β signaling. PMID:27252848

  19. Iron overload inhibits osteogenic commitment and differentiation of mesenchymal stem cells via the induction of ferritin.

    PubMed

    Balogh, Enikő; Tolnai, Emese; Nagy, Béla; Nagy, Béla; Balla, György; Balla, József; Jeney, Viktória

    2016-09-01

    Osteogenic differentiation of multipotent mesenchymal stem cells (MSCs) plays a crucial role in bone remodeling. Numerous studies have described the deleterious effect of iron overload on bone density and microarchitecture. Excess iron decreases osteoblast activity, leading to impaired extracellular matrix (ECM) mineralization. Additionally, iron overload facilitates osteoclast differentiation and bone resorption. These processes contribute to iron overload-associated bone loss. In this study we investigated the effect of iron on osteogenic differentiation of human bone marrow MSCs (BMSCs), the third player in bone remodeling. We induced osteogenic differentiation of BMSCs in the presence or absence of iron (0-50μmol/L) and examined ECM mineralization, Ca content of the ECM, mRNA and protein expressions of the osteogenic transcription factor runt-related transcription factor 2 (Runx2), and its targets osteocalcin (OCN) and alkaline phosphatase (ALP). Iron dose-dependently attenuated ECM mineralization and decreased the expressions of Runx2 and OCN. Iron accomplished complete inhibition of osteogenic differentiation of BMSCs at 50μmol/L concentration. We demonstrated that in response to iron BMSCs upregulated the expression of ferritin. Administration of exogenous ferritin mimicked the anti-osteogenic effect of iron, and blocked the upregulation of Runx2, OCN and ALP. Iron overload in mice was associated with elevated ferritin and decreased Runx2 mRNA levels in compact bone osteoprogenitor cells. The inhibitory effect of iron is specific toward osteogenic differentiation of MSCs as neither chondrogenesis nor adipogenesis were influenced by excess iron. We concluded that iron and ferritin specifically inhibit osteogenic commitment and differentiation of BMSCs both in vitro and in vivo. PMID:27287253

  20. Acute sacroiliitis.

    PubMed

    Slobodin, Gleb; Rimar, Doron; Boulman, Nina; Kaly, Lisa; Rozenbaum, Michael; Rosner, Itzhak; Odeh, Majed

    2016-04-01

    The purpose of this study was to review the data on the etiology, risk factors, clinical presentations, and diagnosis of acute sacroiliitis. A Pubmed search utilizing the indexing term "acute sacroiliitis" was conducted and the data pertinent to the aim of the review was extracted and organized in accordance with the preplanned structure of the manuscript. The diagnosis of acute sacroiliitis is often challenging because of both the relative rarity of this presentation and diverse character of acute sacroiliac pain, frequently mimicking other, more prevalent disorders. Technetium bone scintigraphy can localize the disease process to the sacroiliac joint, while computed tomography or magnetic resonance imaging can be used for the detailed characterization and the extent of the disease as well as the diagnosis of complications. Pyogenic sacroiliitis is by far the most common cause of acute sacroiliitis. Brucellosis, acute sacroiliitis in the course of reactive arthritis, and crystalline-induced sacroiliitis frequently imitate pyogenic sacroiliitis. Acute sacroiliitis can rarely be also related to hematological malignancies or treatment with isotretinoin. Awareness to the possibility of acute sacroiliitis and a thorough physical examination are the necessary prerequisites to its timely diagnosis, while the appropriate laboratory and imaging studies should confirm the precise diagnosis and direct the appropriate treatment strategy. PMID:26847855

  1. Thymoquinone, a bioactive component of Nigella sativa, normalizes insulin secretion from pancreatic β-cells under glucose overload via regulation of malonyl-CoA.

    PubMed

    Gray, Joshua P; Burgos, Delaine Zayasbazan; Yuan, Tao; Seeram, Navindra; Rebar, Rebecca; Follmer, Rebecca; Heart, Emma A

    2016-03-15

    Thymoquinone (2-isopropyl-5-methylbenzo-1,4-quinone) is a major bioactive component of Nigella sativa, a plant used in traditional medicine to treat a variety of symptoms, including elevated blood glucose levels in type 2 diabetic patients. Normalization of elevated blood glucose depends on both glucose disposal by peripheral tissues and glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells. We employed clonal β-cells and rodent islets to investigate the effects of thymoquinone (TQ) and Nigella sativa extracts (NSEs) on GSIS and cataplerotic metabolic pathways implicated in the regulation of GSIS. TQ and NSE regulated NAD(P)H/NAD(P)(+) ratios via a quinone-dependent redox cycling mechanism. TQ content was positively correlated with the degree of redox cycling activity of NSE extracts, suggesting that TQ is a major component engaged in mediating NSE-dependent redox cycling. Both acute and chronic exposure to TQ and NSE enhanced GSIS and were associated with the ability of TQ and NSE to increase the ATP/ADP ratio. Furthermore, TQ ameliorated the impairment of GSIS following chronic exposure of β-cells to glucose overload. This protective action was associated with the TQ-dependent normalization of chronic accumulation of malonyl-CoA, elevation of acetyl-CoA carboxylase (ACC), fatty acid synthase, and fatty acid-binding proteins following chronic glucose overload. Together, these data suggest that TQ modulates the β-cell redox circuitry and enhances the sensitivity of β-cell metabolic pathways to glucose and GSIS under normal conditions as well as under hyperglycemia. This action is associated with the ability of TQ to regulate carbohydrate-to-lipid flux via downregulation of ACC and malonyl-CoA. PMID:26786775

  2. [Electrovectorcardiographic aspects of systolic and diastolic overloads of the left ventricle].

    PubMed

    de Micheli, A; Medrano, G A; Casanova, J M

    1990-01-01

    Electrovectorcardiographic features of the ventricular depolarization and repolarization related to hemodynamic conditions were studied in typical cases of left ventricular systolic and diastolic overloads. Electrovectorcardiographic exploration was effected prospectively in 70 subjects with aortic coarctation (52 men and 18 women) and in 90 with patent ductus arteriosus (18 men and 72 women). Fifty-five subjects of the series with systolic overload (A) and sixty-five with diastolic overload (B) underwent surgical treatment. In all cases, high fidelity tracings were obtained by means of a VR-6 polygraph: standard leads, unipolar limb leads, thoracic and precordial unipolar leads from V7R to V7 or V8, high abdominal leads MD, ME, MI and, when it was possible, the corresponding intraventricular unipolar leads. Vectorcardiographic curves were recorded in three planes by Grishman's cube method and photographed using the polaroid system. In both series, ventricular conduction disturbances of proximal or peripheral types were observed. These seem to be independent of hemodynamic conditions. In the presence of aortic coarctation as well as of patent ductus arteriosus, the Q-Tc interval can be prolonged in all leads, probably owing to electrolytic disorders, or in left leads only as a reflection of elevated telediastolic pressure in the ipsilateral ventricle. PMID:2378532

  3. Psychophysiological responses to overloading and tapering phases in elite young soccer players.

    PubMed

    Freitas, Camila G; Aoki, Marcelo S; Franciscon, Clovis A; Arruda, Ademir F S; Carling, Christopher; Moreira, Alexandre

    2014-05-01

    This study investigated the effect of a 2-week overloading training phase followed by a 2-week tapering phase on internal training load (ITL), salivary cortisol, stress tolerance, and upper respiratory tract infections symptoms (URTI) in 11 male young soccer players (16.0 ± 0.5 yrs). Ratings of perceived exertion (session- RPE) were taken after each training session (N = 194) to determine ITL. Saliva sampling was conducted at the end of each week and cortisol concentration assessed by ELISA. DALDA and WURSS-21 questionnaires were administered every week to evaluate stress tolerance and severity of URTI respectively. The number of athletes reporting URTI symptoms was recorded. The overloading phase promoted greater ITL and a higher resting cortisol concentration than the tapering phase (P < .05). While no significant changes in stress tolerance or URTI severity were observed, the number of athletes reporting URTI symptoms was higher during the overloading phase. A significant correlation was observed between symptoms of stress and severity of URTI (rs=-.71; P = .01). The results indicate that an integrated approach using psychological measures (session-RPE and DALDA), self-reports of URTI symptoms, and endocrine responses (cortisol) to training are pertinent for monitoring young soccer players. PMID:24722819

  4. The Succinate Receptor GPR91 Is Involved in Pressure Overload-Induced Ventricular Hypertrophy

    PubMed Central

    Hu, Liang; Feng, Yu; Wang, Song; Zhang, Wei-yan; Yin, Ning; Mo, Xu-Ming

    2016-01-01

    Background Pulmonary arterial hypertension is characterized by increased pressure overload that leads to right ventricular hypertrophy (RVH). GPR91 is a formerly orphan G-protein-coupled receptor (GPCR) that has been characterized as a receptor for succinate; however, its role in RVH remains unknown. Methods and Results We investigated the role of succinate-GPR91 signaling in a pulmonary arterial banding (PAB) model of RVH induced by pressure overload in SD rats. GPR91 was shown to be located in cardiomyocytes. In the sham and PAB rats, succinate treatment further aggravated RVH, up-regulated RVH-associated genes and increased p-Akt/t-Akt levels in vivo. In vitro, succinate treatment up-regulated the levels of the hypertrophic gene marker anp and p-Akt/t-Akt in cardiomyocytes. All these effects were inhibited by the PI3K antagonist wortmannin both in vivo and in vitro. Finally, we noted that the GPR91-PI3K/Akt axis was also up-regulated compared to that in human RVH. Conclusions Our findings indicate that succinate-GPR91 signaling may be involved in RVH via PI3K/Akt signaling in vivo and in vitro. Therefore, GPR91 may be a novel therapeutic target for treating pressure overload-induced RVH. PMID:26824665

  5. Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model

    PubMed Central

    S, Santhosh Kumar; G, Sanjay; Kartha, Chandrasekharan Cheranellore

    2014-01-01

    Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart failure. Here, we describe a detailed surgical procedure for creating pressure overload and cardiac hypertrophy in rats by constriction of the ascending aorta using a small metallic clip. After anesthesia, the trachea is intubated by inserting a cannula through a half way incision made between two cartilage rings of trachea. Then a skin incision is made at the level of the second intercostal space on the left chest wall and muscle layers are cleared to locate the ascending portion of aorta. The ascending aorta is constricted to 50–60% of its original diameter by application of a small sized titanium clip. Following aortic constriction, the second and third ribs are approximated with prolene sutures. The tracheal cannula is removed once spontaneous breathing was re-established. The animal is allowed to recover on the heating pad by gradually lowering anesthesia. The intensity of pressure overload created by constriction of the ascending aorta is determined by recording the pressure gradient using trans-thoracic two dimensional Doppler-echocardiography. Overall this protocol is useful to study the remodeling events and contractile properties of the heart during the gradual onset and progression from compensated cardiac hypertrophy to heart failure stage. PMID:24998889

  6. Iron Overload Coordinately Promotes Ferritin Expression and Fat Accumulation in Caenorhabditis elegans.

    PubMed

    Wang, Haizhen; Jiang, Xue; Wu, Jieyu; Zhang, Linqiang; Huang, Jingfei; Zhang, Yuru; Zou, Xiaoju; Liang, Bin

    2016-05-01

    The trace element iron is crucial for living organisms, since it plays essential roles in numerous cellular functions. Systemic iron overload and the elevated level of ferritin, a ubiquitous intracellular protein that stores and releases iron to maintain the iron homeostasis in cells, has long been epidemiologically associated with obesity and obesity-related diseases. However, the underlying mechanisms of this association remain unclear. Here, using Caenorhabditis elegans, we show that iron overload induces the expression of sgk-1, encoding the serum and glucocorticoid-inducible kinase, to promote the level of ferritin and fat accumulation. Mutation of cyp-23A1, encoding a homolog of human cytochrome P450 CYP7B1 that is related to neonatal hemochromatosis, further enhances the elevated expression of ftn-1, sgk-1, and fat accumulation. sgk-1 positively regulates the expression of acs-20 and vit-2, genes encoding homologs of the mammalian FATP1/4 fatty acid transport proteins and yolk lipoproteins, respectively, to facilitate lipid uptake and translocation for storage under iron overload. This study reveals a completely novel pathway in which sgk-1 plays a central role to synergistically regulate iron and lipid homeostasis, offering not only experimental evidence supporting a previously unverified link between iron and obesity, but also novel insights into the pathogenesis of iron and obesity-related human metabolic diseases. PMID:27017620

  7. Functional Role of HSP47 in the Periodontal Ligament Subjected to Occlusal Overload in Mice

    PubMed Central

    Mimura, Hiroaki; Takaya, Tatsuo; Matsuda, Saeka; Nakano, Keisuke; Muraoka, Rina; Tomida, Mihoko; Okafuji, Norimasa; Fujii, Takeo; Kawakami, Toshiyuki

    2016-01-01

    We carried out an experiment to induce traumatic occlusion in mice periodontal tissue and analyzed the expression of HSP47. Continuous traumatic occlusion resulted to damage and remodeling of periodontal ligament as well as increase in osteoclasts and bone resorption. Four days after traumatic occlusion, osteoclasts did not increase but Howship's lacunae became enlarged. That is, the persistent occlusal overload can destroy collagen fibers in the periodontal ligament. This was evident by the increased in HSP47 expression with the occlusal overload. HSP47 is maintained in fibroblasts for repair of damaged collagen fibers. On the other hand, osteoclasts continue to increase although the load was released. The osteoclasts that appeared on the alveolar bone surface were likely due to sustained activity. The increase in osteoclasts was estimated to occur after load application at day 4. HSP47 continued to increase until day 6 in experiment 2 but then reduced at day 10. Therefore, HSP47 appears after a period of certain activities to repair damaged collagen fibers, and the activity was returned to a state of equilibrium at day 30 with significantly diminished expression. Thus, the results suggest that HSP47 is actively involved in homeostasis of periodontal tissue subjected to occlusal overload. PMID:27076780

  8. Hepatic nerve growth factor induced by iron overload triggers defenestration in liver sinusoidal endothelial cells.

    PubMed

    Addo, Lynda; Tanaka, Hiroki; Yamamoto, Masayo; Toki, Yasumichi; Ito, Satoshi; Ikuta, Katsuya; Sasaki, Katsunori; Ohtake, Takaaki; Torimoto, Yoshihiro; Fujiya, Mikihiro; Kohgo, Yutaka

    2015-01-01

    The fenestrations of liver sinusoidal endothelial cells (LSECs) play important roles in the exchange of macromolecules, solutes, and fluid between blood and surrounding liver tissues in response to hepatotoxic drugs, toxins, and oxidative stress. As excess iron is a hepatotoxin, LSECs may be affected by excess iron. In this study, we found a novel link between LSEC defenestration and hepatic nerve growth factor (NGF) in iron-overloaded mice. By Western blotting, NGF was highly expressed, whereas VEGF and HGF were not, and hepatic NGF mRNA levels were increased according to digital PCR. Immunohistochemically, NGF staining was localized in hepatocytes, while TrkA, an NGF receptor, was localized in LSECs. Scanning electron microscopy revealed LSEC defenestration in mice overloaded with iron as well as mice treated with recombinant NGF. Treatment with conditioned medium from iron-overloaded primary hepatocytes reduced primary LSEC fenestrations, while treatment with an anti-NGF neutralizing antibody or TrkA inhibitor, K252a, reversed this effect. However, iron-loaded medium itself did not reduce fenestration. In conclusion, iron accumulation induces NGF expression in hepatocytes, which in turn leads to LSEC defenestration via TrkA. This novel link between iron and NGF may aid our understanding of the development of chronic liver disease. PMID:25460199

  9. Cellular growth defects triggered by an overload of protein localization processes

    PubMed Central

    Kintaka, Reiko; Makanae, Koji; Moriya, Hisao

    2016-01-01

    High-level expression of a protein localized to an intracellular compartment is expected to cause cellular defects because it overloads localization processes. However, overloads of localization processes have never been studied systematically. Here, we show that the expression levels of green fluorescent proteins (GFPs) with localization signals were limited to the same degree as a toxic misfolded GFP in budding yeast cells, and that their high-level expression caused cellular defects associated with localization processes. We further show that limitation of the exportin Crm1 determined the expression limit of GFP with a nuclear export signal. Although misfolding of GFP with a vesicle-mediated transport signal triggered endoplasmic reticulum stress, it was not the primary determinant of its expression limit. The precursor of GFP with a mitochondrial targeting signal caused a cellular defect. Finally, we estimated the residual capacities of localization processes. High-level expression of a localized protein thus causes cellular defects by overloading the capacities of localization processes. PMID:27538565

  10. Cellular growth defects triggered by an overload of protein localization processes.

    PubMed

    Kintaka, Reiko; Makanae, Koji; Moriya, Hisao

    2016-01-01

    High-level expression of a protein localized to an intracellular compartment is expected to cause cellular defects because it overloads localization processes. However, overloads of localization processes have never been studied systematically. Here, we show that the expression levels of green fluorescent proteins (GFPs) with localization signals were limited to the same degree as a toxic misfolded GFP in budding yeast cells, and that their high-level expression caused cellular defects associated with localization processes. We further show that limitation of the exportin Crm1 determined the expression limit of GFP with a nuclear export signal. Although misfolding of GFP with a vesicle-mediated transport signal triggered endoplasmic reticulum stress, it was not the primary determinant of its expression limit. The precursor of GFP with a mitochondrial targeting signal caused a cellular defect. Finally, we estimated the residual capacities of localization processes. High-level expression of a localized protein thus causes cellular defects by overloading the capacities of localization processes. PMID:27538565

  11. The Design and Optimization of a Highly Sensitive and Overload-Resistant Piezoresistive Pressure Sensor

    PubMed Central

    Meng, Xiawei; Zhao, Yulong

    2016-01-01

    A piezoresistive pressure sensor with a beam-membrane-dual-island structure is developed for micro-pressure monitoring in the field of aviation, which requires great sensitivity and overload resistance capacity. The design, fabrication, and test of the sensor are presented in this paper. By analyzing the stress distribution of sensitive elements using the finite element method, a novel structure incorporating sensitive beams with a traditional bossed diaphragm is built up. The proposed structure proved to be advantageous in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the sensor equations. Fabricated on an n-type single crystal silicon wafer, the sensor chips are wire-bonded to a printed circuit board (PCB) and packaged for experiments. The static and dynamic characteristics are tested and discussed. Experimental results show that the sensor has a sensitivity as high as 17.339 μV/V/Pa in the range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure. Due to the excellent performance, the sensor can be applied in measuring micro-pressure lower than 500 Pa. PMID:27005627

  12. Design of overload vehicle monitoring and response system based on DSP

    NASA Astrophysics Data System (ADS)

    Yu, Yan; Liu, Yiheng; Zhao, Xuefeng

    2014-03-01

    The overload vehicles are making much more damage to the road surface than the regular ones. Many roads and bridges are equipped with structural health monitoring system (SHM) to provide early-warning to these damage and evaluate the safety of road and bridge. However, because of the complex nature of SHM system, it's expensive to manufacture, difficult to install and not well-suited for the regular bridges and roads. Based on this application background, this paper designs a compact structural health monitoring system based on DSP, which is highly integrated, low-power, easy to install and inexpensive to manufacture. The designed system is made up of sensor arrays, the charge amplifier module, the DSP processing unit, the alarm system for overload, and the estimate for damage of the road and bridge structure. The signals coming from sensor arrays go through the charge amplifier. DSP processing unit will receive the amplified signals, estimate whether it is an overload signal or not, and convert analog variables into digital ones so that they are compatible with the back-end digital circuit for further processing. The system will also restrict certain vehicles that are overweight, by taking image of the car brand, sending the alarm, and transferring the collected pressure data to remote data center for further monitoring analysis by rain-flow counting method.

  13. Provider Role Attitudes, Marital Satisfaction, Role Overload, and Housework: A Dyadic Approach

    PubMed Central

    Helms, Heather M.; Walls, Jill K.; Crouter, Ann C.; McHale, Susan M.

    2010-01-01

    Treating the marital dyad as the unit of analysis, this study examined the within-couple patterning of 272 dual-earner spouses’ provider role attitudes and their longitudinal associations with marital satisfaction, role overload, and the division of housework. Based on the congruence of husbands’ and wives’ provider role attitudes, couples were classified into one of four types: (1) main-secondary, (2) coprovider, (3) ambivalent coprovider, and (4) mismatched couples. Nearly half of all spouses differed in their attitudes about breadwinning. A series of mixed model ANCOVAs revealed significant between- and within-couple differences in human capital characteristics, spouses’ perceptions of marital satisfaction and role overload, and the division of housework across 3 years of measurement. Coprovider couples reported higher levels of marital satisfaction and a more equitable division of housework than the other couple groups. Wives in the ambivalent coprovider couples’ group reported higher levels of role overload than their husbands to a greater extent than was found in the other couple groups. As the first study to adopt a dyadic approach that considers the meanings that both spouses in dual-earner couples ascribe to paid employment, these findings advance understanding of how dual-earner spouses’ provider role attitudes serve as contexts for marital quality, behavior, and role-related stress. PMID:20954767

  14. Estimating User Influence in Online Social Networks Subject to Information Overload

    NASA Astrophysics Data System (ADS)

    Li, Pei; Sun, Yunchuan; Chen, Yingwen; Tian, Zhi

    2014-11-01

    Online social networks have attracted remarkable attention since they provide various approaches for hundreds of millions of people to stay connected with their friends. Due to the existence of information overload, the research on diffusion dynamics in epidemiology cannot be adopted directly to that in online social networks. In this paper, we consider diffusion dynamics in online social networks subject to information overload, and model the information-processing process of a user by a queue with a batch arrival and a finite buffer. We use the average number of times a message is processed after it is generated by a given user to characterize the user influence, which is then estimated through theoretical analysis for a given network. We validate the accuracy of our estimation by simulations, and apply the results to study the impacts of different factors on the user influence. Among the observations, we find that the impact of network size on the user influence is marginal while the user influence decreases with assortativity due to information overload, which is particularly interesting.

  15. Low molecular weight fucoidan protects renal tubular cells from injury induced by albumin overload

    PubMed Central

    Jia, Yingli; Sun, Yi; Weng, Lin; Li, Yingjie; Zhang, Quanbin; Zhou, Hong; Yang, Baoxue

    2016-01-01

    Albuminuria is a causative and aggravating factor for progressive renal damage in chronic kidney disease (CKD). The aim of this study was to determine if low molecular weight fucoidan (LMWF) could protect renal function and tubular cells from albumin overload caused injury. Treatment with 10 mg/g bovine serum albumin caused renal dysfunction, morphological changes, and overexpression of inflammation and fibrosis associated proteins in 129S2/Sv mice. LMWF (100 mg/kg) protected against kidney injury and renal dysfunction with decreased blood creatinine by 34% and urea nitrogen by 25%, increased creatinine clearance by 48%, and decreased significantly urinary albumin concentration. In vitro proximal tubule epithelial cell (NRK-52E) model showed that LMWF dose-dependently inhibited overexpression of proinflammatory and profibrotic factors, oxidative stress and apoptosis caused by albumin overload. These experimental results indicate that LMWF protects against albumin overload caused renal injury by inhibiting inflammation, fibrosis, oxidative stress and apoptosis, which suggests that LMWF could be a promising candidate drug for preventing CKD. PMID:27545472

  16. Modeling of Information Diffusion in Twitter-Like Social Networks under Information Overload

    PubMed Central

    Li, Wei

    2014-01-01

    Due to the existence of information overload in social networks, it becomes increasingly difficult for users to find useful information according to their interests. This paper takes Twitter-like social networks into account and proposes models to characterize the process of information diffusion under information overload. Users are classified into different types according to their in-degrees and out-degrees, and user behaviors are generalized into two categories: generating and forwarding. View scope is introduced to model the user information-processing capability under information overload, and the average number of times a message appears in view scopes after it is generated by a given type user is adopted to characterize the information diffusion efficiency, which is calculated theoretically. To verify the accuracy of theoretical analysis results, we conduct simulations and provide the simulation results, which are consistent with the theoretical analysis results perfectly. These results are of importance to understand the diffusion dynamics in social networks, and this analysis framework can be extended to consider more realistic situations. PMID:24795541

  17. Mechanisms of fatigue crack retardation following single tensile overloads in powder metallurgy aluminum alloys

    NASA Technical Reports Server (NTRS)

    Bray, G. H.; Reynolds, A. P.; Starke, E. A., Jr.

    1992-01-01

    In ingot metallurgy (IM) alloys, the number of delay cycles following a single tensile overload typically increases from a minimum at an intermediate baseline stress intensity range, Delta-K(B), with decreasing Delta-K(B) approaching threshold and increasing Delta-K(B) approaching unstable fracture to produce a characteristic 'U' shaped curve. Two models have been proposed to explain this behavior. One model is based on the interaction between roughness and plasticity-induced closure, while the other model only utilizes plasticity-induced closure. This article examines these models, using experimental results from constant amplitude and single overload fatigue tests performed on two powder metallurgy (PM) aluminum alloys, AL-905XL and AA 8009. The results indicate that the 'U'-shaped curve is primarily due to plasticity-induced closure, and that the plasticity-induced retardation effect is through-thickness in nature, occurring in both the surface and interior regions. However, the retardation effect is greater at the surface, because the increase in plastic strain at the crack tip and overload plastic zone size are larger in the plane-stress surface regions than in the plane-strain interior regions. These results are not entirely consistent with either of the proposed models.

  18. Biochemical Competition Makes Fatty-Acid β-Oxidation Vulnerable to Substrate Overload

    PubMed Central

    van Eunen, Karen; Simons, Sereh M. J.; Gerding, Albert; Bleeker, Aycha; den Besten, Gijs; Touw, Catharina M. L.; Houten, Sander M.; Groen, Bert K.; Krab, Klaas; Reijngoud, Dirk-Jan; Bakker, Barbara M.

    2013-01-01

    Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH). The mitochondrial [NAD+]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration. PMID:23966849

  19. Marginal peri-implantitis due to occlusal overload. A case report.

    PubMed

    Uribe, Roberto; Peñarrocha, Miguel; Sanchis, Jose María; García, Oscar

    2004-01-01

    The etiology of marginal peri-implantitis describes an infectious factor and a biomechanical factor resulting from occlusal overload. Clinical and experimental articles oriented to the biomechanical factor are scarce, so as the studies about the histology associated to periimplantitis. We present a case of marginal peri-implantitis on an implant in the mandibular molar zone caused by occlusal overload, which led to an osseous defect on the marginal crest. The treatment was composed of occlusal adjustment, removal of contaminated surgical tissue, and autogenous bone graft, which varies from the common treatment of infectious peri-implantitis. Histologic analysis of peri-implantitis tissue reveals a juxtaepithelial lympho-plasmocytorious infiltrate and a central zone of dense fibro-connective tissue with scanty inflammatory cells, which differs from the chronic inflammatory tissue associated with infectious peri-implantitis. Clinical and radiographic followup control after 12 months evidenced the remission of the symptoms and bone regeneration on the marginal crest. We consider that in the treatment of marginal peri-implantitis, it is necessary to continue the studies on the histological differences between the infectious types and those that are caused by occlusal overload. PMID:14990883

  20. Low molecular weight fucoidan protects renal tubular cells from injury induced by albumin overload.

    PubMed

    Jia, Yingli; Sun, Yi; Weng, Lin; Li, Yingjie; Zhang, Quanbin; Zhou, Hong; Yang, Baoxue

    2016-01-01

    Albuminuria is a causative and aggravating factor for progressive renal damage in chronic kidney disease (CKD). The aim of this study was to determine if low molecular weight fucoidan (LMWF) could protect renal function and tubular cells from albumin overload caused injury. Treatment with 10 mg/g bovine serum albumin caused renal dysfunction, morphological changes, and overexpression of inflammation and fibrosis associated proteins in 129S2/Sv mice. LMWF (100 mg/kg) protected against kidney injury and renal dysfunction with decreased blood creatinine by 34% and urea nitrogen by 25%, increased creatinine clearance by 48%, and decreased significantly urinary albumin concentration. In vitro proximal tubule epithelial cell (NRK-52E) model showed that LMWF dose-dependently inhibited overexpression of proinflammatory and profibrotic factors, oxidative stress and apoptosis caused by albumin overload. These experimental results indicate that LMWF protects against albumin overload caused renal injury by inhibiting inflammation, fibrosis, oxidative stress and apoptosis, which suggests that LMWF could be a promising candidate drug for preventing CKD. PMID:27545472

  1. Iron Overload in Allogeneic Hematopoietic Cell Transplantation Outcome: A Meta-Analysis

    PubMed Central

    Armand, Philippe; Kim, Haesook T.; Virtanen, Johanna M.; Parkkola, Riitta K.; Itälä-Remes, Maija A.; Majhail, Navneet S.; Burns, Linda J.; DeFor, Todd; Trottier, Bryan; Platzbecker, Uwe; Antin, Joseph H.; Wermke, Martin

    2014-01-01

    An elevated ferritin before allogeneic hematopoietic cell transplantation (HCT) is an adverse prognostic factor for overall survival (OS) and non-relapse mortality (NRM). Because ferritin is an imperfect surrogate of iron stores, the prognostic role of iron overload remains unclear. We conducted a patient-level meta-analysis of 4 studies that used magnetic resonance imaging to estimate pre-HCT liver iron content (LIC). An elevated LIC was not associated with a significant increase in mortality: the hazard ratio (HR) for mortality associated with LIC>7 mg/gdw (primary endpoint) was 1.4 (p=0.18). In contrast, ferritin >1000 ng/ml was a significant prognostic factor (HR for mortality 1.7, p=0.036). There was, however, no significant association between ferritin>2500 and mortality. This meta-analysis suggests that iron overload, as assessed by LIC, is not a strong prognostic factor for OS in a general adult HCT population. Our data also suggest that ferritin is an inadequate surrogate for iron overload in HCT. PMID:24769316

  2. The Design and Optimization of a Highly Sensitive and Overload-Resistant Piezoresistive Pressure Sensor.

    PubMed

    Meng, Xiawei; Zhao, Yulong

    2016-01-01

    A piezoresistive pressure sensor with a beam-membrane-dual-island structure is developed for micro-pressure monitoring in the field of aviation, which requires great sensitivity and overload resistance capacity. The design, fabrication, and test of the sensor are presented in this paper. By analyzing the stress distribution of sensitive elements using the finite element method, a novel structure incorporating sensitive beams with a traditional bossed diaphragm is built up. The proposed structure proved to be advantageous in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the sensor equations. Fabricated on an n-type single crystal silicon wafer, the sensor chips are wire-bonded to a printed circuit board (PCB) and packaged for experiments. The static and dynamic characteristics are tested and discussed. Experimental results show that the sensor has a sensitivity as high as 17.339 μV/V/Pa in the range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure. Due to the excellent performance, the sensor can be applied in measuring micro-pressure lower than 500 Pa. PMID:27005627

  3. Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions.

    PubMed

    Chalmers, Anna W; Shammo, Jamile M

    2016-01-01

    Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelo-dysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu(®) for the reduction of transfusional iron overload in hematological disorders. PMID:26929633

  4. Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions

    PubMed Central

    Chalmers, Anna W; Shammo, Jamile M

    2016-01-01

    Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelo-dysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu® for the reduction of transfusional iron overload in hematological disorders. PMID:26929633

  5. Cytosolic H2O2 mediates hypertrophy, apoptosis, and decreased SERCA activity in mice with chronic hemodynamic overload.

    PubMed

    Qin, Fuzhong; Siwik, Deborah A; Pimentel, David R; Morgan, Robert J; Biolo, Andreia; Tu, Vivian H; Kang, Y James; Cohen, Richard A; Colucci, Wilson S

    2014-05-15

    Oxidative stress in the myocardium plays an important role in the pathophysiology of hemodynamic overload. The mechanism by which reactive oxygen species (ROS) in the cardiac myocyte mediate myocardial failure in hemodynamic overload is not known. Accordingly, our goals were to test whether myocyte-specific overexpression of peroxisomal catalase (pCAT) that localizes in the sarcoplasm protects mice from hemodynamic overload-induced failure and prevents oxidation and inhibition of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA), an important sarcoplasmic protein. Chronic hemodynamic overload was caused by ascending aortic constriction (AAC) for 12 wk in mice with myocyte-specific transgenic expression of pCAT. AAC caused left ventricular hypertrophy and failure associated with a generalized increase in myocardial oxidative stress and specific oxidative modifications of SERCA at cysteine 674 and tyrosine 294/5. pCAT overexpression ameliorated myocardial hypertrophy and apoptosis, decreased pathological remodeling, and prevented the progression to heart failure. Likewise, pCAT prevented oxidative modifications of SERCA and increased SERCA activity without changing SERCA expression. Thus cardiac myocyte-restricted expression of pCAT effectively ameliorated the structural and functional consequences of chronic hemodynamic overload and increased SERCA activity via a post-translational mechanism, most likely by decreasing inhibitory oxidative modifications. In pressure overload-induced heart failure cardiac myocyte cytosolic ROS play a pivotal role in mediating key pathophysiologic events including hypertrophy, apoptosis, and decreased SERCA activity. PMID:24633550

  6. Acute tubular necrosis

    MedlinePlus

    ... in the following cases: Decreased mental status Fluid overload Increased potassium level Pericarditis Removal of toxins that ... to achieve this important distinction for online health information and services. Learn more about A.D.A. ...

  7. Hypertrophic response to hemodynamic overload: role of load vs. renin-angiotensin system activation

    NASA Technical Reports Server (NTRS)

    Koide, M.; Carabello, B. A.; Conrad, C. C.; Buckley, J. M.; DeFreyte, G.; Barnes, M.; Tomanek, R. J.; Wei, C. C.; Dell'Italia, L. J.; Cooper, G. 4th; Zile, M. R.

    1999-01-01

    Myocardial hypertrophy is one of the basic mechanisms by which the heart compensates for hemodynamic overload. The mechanisms by which hemodynamic overload is transduced by the cardiac muscle cell and translated into cardiac hypertrophy are not completely understood. Candidates include activation of the renin-angiotensin system (RAS) and angiotensin II receptor (AT1) stimulation. In this study, we tested the hypothesis that load, independent of the RAS, is sufficient to stimulate cardiac growth. Four groups of cats were studied: 14 normal controls, 20 pulmonary artery-banded (PAB) cats, 7 PAB cats in whom the AT1 was concomitantly and continuously blocked with losartan, and 8 PAB cats in whom the angiotensin-converting enzyme (ACE) was concomitantly and continuously blocked with captopril. Losartan cats had at least a one-log order increase in the ED50 of the blood pressure response to angiotensin II infusion. Right ventricular (RV) hypertrophy was assessed using the RV mass-to-body weight ratio and ventricular cardiocyte size. RV hemodynamic overload was assessed by measuring RV systolic and diastolic pressures. Neither the extent of RV pressure overload nor RV hypertrophy that resulted from PAB was affected by AT1 blockade with losartan or ACE inhibition with captopril. RV systolic pressure was increased from 21 +/- 3 mmHg in normals to 68 +/- 4 mmHg in PAB, 65 +/- 5 mmHg in PAB plus losartan and 62 +/- 3 mmHg in PAB plus captopril. RV-to-body weight ratio increased from 0.52 +/- 0.04 g/kg in normals to 1.11 +/- 0.06 g/kg in PAB, 1.06 +/- 0.06 g/kg in PAB plus losartan and 1.06 +/- 0.06 g/kg in PAB plus captopril. Thus 1) pharmacological modulation of the RAS with losartan and captopril did not change the extent of the hemodynamic overload or the hypertrophic response induced by PAB; 2) neither RAS activation nor angiotensin II receptor stimulation is an obligatory and necessary component of the signaling pathway that acts as an intermediary coupling load to the

  8. Reassessment of Iron Biomarkers for Prediction of Dialysis Iron Overload: An MRI Study

    PubMed Central

    Rostoker, Guy; Griuncelli, Mireille; Loridon, Christelle; Magna, Théophile; Machado, Gabrielle; Drahi, Gilles; Dahan, Hervé; Janklewicz, Philippe; Cohen, Yves

    2015-01-01

    Background and Objectives Iron overload among hemodialysis patients was previously considered rare but is now an increasingly recognized clinical situation. We analyzed correlations between iron biomarkers and the liver iron concentration (LIC) measured by magnetic resonance imaging (MRI), and examined their diagnostic accuracy for iron overload. Design, Setting, Participants and Measurements We performed a prospective cross-sectional study from 31 January 2005 to 31 August 2013 in the dialysis centre of a French community-based private hospital. A cohort of 212 hemodialysis patients free of overt inflammation or malnutrition, were treated for anemia with parenteral iron-sucrose and an erythropoesis-stimulating agent, in keeping with current clinical guidelines. Blinded measurements of hepatic iron stores were performed by T1 and T2* contrast MRI, and relationships were analysed using Spearman’s coefficient, logistic regression and receiver-operator characteristic (ROC) curves. Results Among the biological markers, only serum ferritin showed a strong correlation with LIC (rho= 0.52, 95% CI: 0.41-0.61, p< 0.0001, Spearman test). In logistic analysis, only serum ferritin correctly classified the overall cohort into patients with normal liver iron stores (LIC ≤ 50 μmol/g) and those with elevated liver iron stores (LIC > 50 μmol/g) (odds ratio 1.007; 95% CI: 1.004-1.010). Serum ferritin was the iron biomarker with the best discriminatory capacity in ROC curves analysis (area under the curve (AUC) = 0.767; 95% CI: 0.698-0.835). The optimal serum ferritin cutoffs were 160 μg/L for LIC > 50 μmol/g (mild iron overload) and 290 μg/L for LIC > 200 μmol/g (severe iron overload). Conclusions For clinical purposes, serum ferritin correctly reflects liver iron stores, as assessed by MRI, in hemodialysis patients without overt inflammation or malnutrition. These results strongly suggest that current ferritin target values should be lowered to avoid iron overload. Trial

  9. Mesenchymal stem cells preserve neonatal right ventricular function in a porcine model of pressure overload.

    PubMed

    Wehman, Brody; Sharma, Sudhish; Pietris, Nicholas; Mishra, Rachana; Siddiqui, Osama T; Bigham, Grace; Li, Tieluo; Aiello, Emily; Murthi, Sarah; Pittenger, Mark; Griffith, Bartley; Kaushal, Sunjay

    2016-06-01

    Limited therapies exist for patients with congenital heart disease (CHD) who develop right ventricular (RV) dysfunction. Bone marrow-derived mesenchymal stem cells (MSCs) have not been evaluated in a preclinical model of pressure overload, which simulates the pathophysiology relevant to many forms of CHD. A neonatal swine model of RV pressure overload was utilized to test the hypothesis that MSCs preserve RV function and attenuate ventricular remodeling. Immunosuppressed Yorkshire swine underwent pulmonary artery banding to induce RV dysfunction. After 30 min, human MSCs (1 million cells, n = 5) or placebo (n = 5) were injected intramyocardially into the RV free wall. Serial transthoracic echocardiography monitored RV functional indices including 2D myocardial strain analysis. Four weeks postinjection, the MSC-treated myocardium had a smaller increase in RV end-diastolic area, end-systolic area, and tricuspid vena contracta width (P < 0.01), increased RV fractional area of change, and improved myocardial strain mechanics relative to placebo (P < 0.01). The MSC-treated myocardium demonstrated enhanced neovessel formation (P < 0.0001), superior recruitment of endogenous c-kit+ cardiac stem cells to the RV (P < 0.0001) and increased proliferation of cardiomyocytes (P = 0.0009) and endothelial cells (P < 0.0001). Hypertrophic changes in the RV were more pronounced in the placebo group, as evidenced by greater wall thickness by echocardiography (P = 0.008), increased cardiomyocyte cross-sectional area (P = 0.001), and increased expression of hypertrophy-related genes, including brain natriuretic peptide, β-myosin heavy chain and myosin light chain. Additionally, MSC-treated myocardium demonstrated increased expression of the antihypertrophy secreted factor, growth differentiation factor 15 (GDF15), and its downstream effector, SMAD 2/3, in cultured neonatal rat cardiomyocytes and in the porcine RV myocardium. This is the first report of the use of MSCs as a therapeutic

  10. Pathophysiology of acute heart failure: a world to know.

    PubMed

    Sánchez-Marteles, M; Rubio Gracia, J; Giménez López, I

    2016-01-01

    Our understanding of the pathophysiological mechanisms of heart failure (HF) has changed considerably in recent years, progressing from a merely haemodynamic viewpoint to a concept of systemic and multifactorial involvement in which numerous mechanisms interact and concatenate. The effects of these mechanisms go beyond the heart itself, to other organs of vital importance such as the kidneys, liver and lungs. Despite this, the pathophysiology of acute HF still has aspects that elude our deeper understanding. Haemodynamic overload, venous congestion, neurohormonal systems, natriuretic peptides, inflammation, oxidative stress and its repercussion on cardiac and vascular remodelling are currently considered the main players in acute HF. Starting with the concept of acute HF, this review provides updates on the various mechanisms involved in this disease. PMID:26541707

  11. Time course of changes in the mechanical properties of the canine right and left ventricles during hypertrophy caused by pressure overload.

    PubMed

    Mirsky, I; Laks, M M

    1980-04-01

    We developed a mathematical model of the right and left ventricles to determine whether there is a change in the mechanical properties of muscle during the hypertrophy process resulting from pulmonary arterial banding. Pressure-volume data were obtained from 10 normal dog hearts and 8 dog hearts in which the pulmonary artery was banded for periods of 2--40 weeks. These data were applied to the model, and the time course of wall stress and muscle stiffness was quantified for both ventricles. The results demonstrate that (1) myocardial stiffness is increased in pressure-overload hypertrophy (2) normal right and left ventricular muscle exhibits similar mechanical properties and (3) the relationships between wall stresses and the volume/mass ratios to the period of banding are biphasic. We concluded that (1) increase in muscle stiffness is due to several factors. In the early stages of hypertrophy, it may be predominantly due to fibrosis and, in the later stages, to substantial increases in muscle mass. (2) The progressive increase in muscle stiffness concomitant with the increase in muscle mass may be due to the presence of myocardial cellular projections and fibrosis. (3) The appropriate timing for surgical/medical intervention should take place before low volume:mass ratios and, hence, low wall stresses are attained. PMID:6444557

  12. Acute malocclusion.

    PubMed

    Dupont, John S

    2006-01-01

    Acute malocclusion can result from disturbances in the maxillary/mandibular tooth relationship. These alterations in the occlusal position can result from high fillings, sinus problems, abscesses, periodontal disease, and moving or erupting teeth. Conditions seen less frequently include acute malocclusions secondary to an event (such as trauma) that make a stable dental relationship an unstable one. Patients can demonstrate any of a number of clinical conditions that interfere with their comfort and ability to function. This article provides information on some of the less familiar causes of acute malocclusion. PMID:16689064

  13. [Acute kidney injury in children].

    PubMed

    Amira-Peco-Antić; Paripović, Dusan

    2014-01-01

    Acute kidney injury (AKI) is a clinical condition considered to be the consequence of a sudden decrease (> 25%) or discontinuation of renal function. The term AKI is used instead of the previous term acute renal failure, because it has been demonstrated that even minor renal lesions may cause far-reaching consequences on human health. Contemporary classifications of AKI (RIFLE and AKIN) are based on the change of serum creatinine and urinary output. In the developed countries, AKI is most often caused by renal ischemia, nephrotoxins and sepsis, rather than a (primary) diffuse renal disease, such as glomerulonephritis, interstitial nephritis, renovascular disorder and thrombotic microangiopathy. The main risk factors for hospital AKI are mechanical ventilation, use of vasoactive drugs, stem cell transplantation and diuretic-resistant hypervolemia. Prerenal and parenchymal AKI (previously known as acute tubular necrosis) jointly account for 2/3 of all AKI causes. Diuresis and serum creatinine concentration are not early diagnostic markers of AKI. Potential early biomarkers of AKI are neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, kidney injury molecule-1 (KIM-1), interleukins 6, 8 and 18, and liver-type fatty acid-binding protein (L-FABP). Early detection of kidney impairment, before the increase of serum creatinine, is important for timely initiated therapy and recovery. The goal of AKI treatment is to normalize the fluid and electrolyte status, as well as the correction of acidosis and blood pressure. Since a severe fluid overload resistant to diuretics and inotropic agents is associated with a poor outcome, the initiation of dialysis should not be delayed. The mortality rate of AKI is highest in critically ill children with multiple organ failure and hemodynamically unstable patients. PMID:25033598

  14. Acute Bronchitis

    MedlinePlus

    ... bronchitis? Acute bronchitis is almost always caused by viruses that attack the lining of the bronchial tree ... infection. As your body fights back against these viruses, more swelling occurs and more mucus is produced. ...

  15. Acute Pericarditis

    MedlinePlus

    ... large pericardial effusions). Acute pericarditis usually responds to colchicine or NSAIDs (such as aspirin and ibuprofen ) taken ... reduce pain but relieves it by reducing inflammation. Colchicine also decreases the chance of pericarditis returning later. ...

  16. Vagus nerve stimulation mitigates intrinsic cardiac neuronal remodeling and cardiac hypertrophy induced by chronic pressure overload in guinea pig.

    PubMed

    Beaumont, Eric; Wright, Gary L; Southerland, Elizabeth M; Li, Ying; Chui, Ray; KenKnight, Bruce H; Armour, J Andrew; Ardell, Jeffrey L

    2016-05-15

    Our objective was to determine whether chronic vagus nerve stimulation (VNS) mitigates pressure overload (PO)-induced remodeling of the cardioneural interface. Guinea pigs (n = 48) were randomized to right or left cervical vagus (RCV or LCV) implant. After 2 wk, chronic left ventricular PO was induced by partial (15-20%) aortic constriction. Of the 31 animals surviving PO induction, 10 were randomized to RCV VNS, 9 to LCV VNS, and 12 to sham VNS. VNS was delivered at 20 Hz and 1.14 ± 0.03 mA at a 22% duty cycle. VNS commenced 10 days after PO induction and was maintained for 40 days. Time-matched controls (n = 9) were evaluated concurrently. Echocardiograms were obtained before and 50 days after PO. At termination, intracellular current-clamp recordings of intrinsic cardiac (IC) neurons were studied in vitro to determine effects of therapy on soma characteristics. Ventricular cardiomyocyte sizes were assessed with histology along with immunoblot analysis of selected proteins in myocardial tissue extracts. In sham-treated animals, PO increased cardiac output (34%, P < 0.004), as well as systolic (114%, P < 0.04) and diastolic (49%, P < 0.002) left ventricular volumes, a hemodynamic response prevented by VNS. PO-induced enhancements of IC synaptic efficacy and muscarinic sensitivity of IC neurons were mitigated by chronic VNS. Increased myocyte size, which doubled in PO (P < 0.05), was mitigated by RCV. PO hypertrophic myocardium displayed decreased glycogen synthase (GS) protein levels and accumulation of the phosphorylated (inactive) form of GS. These PO-induced changes in GS were moderated by left VNS. Chronic VNS targets IC neurons accompanying PO to obtund associated adverse cardiomyocyte remodeling. PMID:26993230

  17. [Ascites and acute kidney injury].

    PubMed

    Piano, Salvatore; Tonon, Marta; Angeli, Paolo

    2016-07-01

    Ascites is the most common complication of cirrhosis. Ascites develops as a consequence of an abnormal splanchnic vasodilation with reduction of effecting circulating volume and activation of endogenous vasoconstrictors system causing salt and water retention. Patients with ascites have a high risk to develop further complications of cirrhosis such as hyponatremia, spontaneous bacterial peritonitis and acute kidney injury resulting in a poor survival. In recent years, new studies helped a better understanding of the pathophysiology of ascites and acute kidney injury in cirrhosis. Furthermore, new diagnostic criteria have been proposed for acute kidney injury and hepatorenal syndrome and a new algorithm for their management has been recommended with the aim of an early diagnosis and treatment. Herein we will review the current knowledge on the pathophysiology, diagnosis and treatment of ascites and acute kidney injury in patients with cirrhosis and we will identify the unmet needs that should be clarified in the next years. PMID:27571467

  18. A study on fatigue crack growth behavior subjected to a single tensile overload: Part II. Transfer of stress concentration and its role in overload-induced transient crack growth

    SciTech Connect

    Lee, S. Y.; Choo, Hahn; Liaw, Peter K; An, Ke; Hubbard, Camden R

    2011-01-01

    The combined effects of overload-induced enlarged compressive residual stresses and crack tip blunting with secondary cracks are suggested to be responsible for the observed changes in the crack opening load and resultant post-overload transient crack growth behavior [Lee SY, Liaw PK, Choo H, Rogge RB, Acta Mater 2010;59:485-94]. In this article, in situ neutron diffraction experiments were performed to quantify the influence of the combined effects by investigating the internal-stress evolution at various locations away from the crack tip. In the overload-retardation period, stress concentration occurs in the crack blunting region (an overload point) until a maximum crack arrest load is reached. The stress concentration is then transferred from the blunting region to the propagating crack tip (following the overload), requ