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Sample records for acute volume overload

  1. Meta-Analysis of Ultrafiltration versus Diuretics Treatment Option for Overload Volume Reduction in Patients with Acute Decompensated Heart Failure

    PubMed Central

    Barkoudah, Ebrahim; Kodali, Sindhura; Okoroh, Juliet; Sethi, Rosh; Hulten, Edward; Suemoto, Claudia; Bittencourt, Marcio Sommer

    2015-01-01

    Introduction Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. Objective The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. Methods MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. Results A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): −2.65 to −0.91 kg; p < 0.001) more than those who received standard diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = −0.25 mg/dL; 95% CI: −0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64–1.56; p = 0.993). Conclusion Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality was observed. PMID:25626761

  2. 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.

  3. Impact of Volume Management on Volume Overload and Rehospitalization in CAPD Patients.

    PubMed

    Xu, Yi; Yang, Shen-Min; Wang, Xiao-Hua; Wang, Hai-Fang; Niu, Mei-E; Yang, Yi-Qun; Lu, Guo-Yuan; Pang, Jian-Hong; Wang, Fei; Li, Lin

    2016-12-01

    Heart failure due to volume overload is a major reason for rehospitalization in continuous ambulatory peritoneal dialysis patients. Strict volume control provides better cardiac functions and blood pressure in this population. Volume management, which is a volume control strategy, may decrease volume overload and related complications. Using a quasi-experimental design, 66 continuous ambulatory peritoneal dialysis patients were randomly assigned to the intervention group ( n = 34) and control group ( n = 32). The patients were followed up for 6 months with scheduled clinic and/or telephone visits; the intervention group adopted volume management strategy, while the control group adopted conventional care. Volume overload and cardiac function were compared between the two groups at the baseline and at 6 months. At Month 6, the intervention group resulted in significant improvement in volume overloaded status, cardiac function, and volume-overload-related rehospitalization. Volume management strategy allows for better control of volume overload and is associated with fewer volume-related readmissions.

  4. Slow continuous intracorporeal plasmapheresis for acute fluid overload.

    PubMed

    Handley, Harold H; Gorsuch, Rey; Levin, Nathan W; Ronco, Claudio

    2003-01-01

    Intermittent dialysis is still the predominant treatment for acute or chronic renal insufficiency in the USA despite increasing evidence that slower and longer fluid management therapies are more beneficial to the patient. We have investigated the use of slow continuous intracorporeal plasmapheresis (SCIP) as a more efficient and hemodynamically stable alternative means of treating acute fluid overload. In this paper we discuss preliminary observations on the safety of SCIP catheter insertion, fluid removal, extraction and pathology in Yorkshire pigs. SCIP catheters removed plasma for extracorporeal plasma water removal without significant gross or histopathological changes. Blood chemistry and cell counts remained stable during therapy. Toxicological studies indicated no pyrogenicity, hemolysis, cytotoxicity, acute systemic toxicity, delayed-type hypersensitivity, or blood recalcification coagulation inhibition. Intracutaneous extracts caused only mild irritation. SCIP therapy appears to be safe for use in the removal of plasma and plasma water from experimental animals.

  5. Temporal pattern of left ventricular structural and functional remodeling following reversal of volume overload heart failure

    PubMed Central

    Hutchinson, Kirk R.; Guggilam, Anuradha; Cismowski, Mary J.; Galantowicz, Maarten L.; West, Thomas A.; Stewart, James A.; Zhang, Xiaojin; Lord, Kevin C.

    2011-01-01

    Current surgical management of volume overload-induced heart failure (HF) leads to variable recovery of left ventricular (LV) function despite a return of LV geometry. The mechanisms that prevent restoration of function are unknown but may be related to the timing of intervention and the degree of LV contractile impairment. This study determined whether reduction of aortocaval fistula (ACF)-induced LV volume overload during the compensatory stage of HF results in beneficial LV structural remodeling and restoration of pump function. Rats were subjected to ACF for 4 wk; a subset then received a load-reversal procedure by closing the shunt using a custom-made stent graft approach. Echocardiography or in vivo pressure-volume analysis was used to assess LV morphology and function in sham rats; rats subjected to 4-, 8-, or 15-wk ACF; and rats subjected to 4-wk ACF followed by 4- or 11-wk reversal. Structural and functional changes were correlated to LV collagen content, extracellular matrix (ECM) proteins, and hypertrophic markers. ACF-induced volume overload led to progressive LV chamber dilation and contractile dysfunction. Rats subjected to short-term reversal (4-wk ACF + 4-wk reversal) exhibited improved chamber dimensions (LV diastolic dimension) and LV compliance that were associated with ECM remodeling and normalization of atrial and brain natriuretic peptides. Load-independent parameters indicated LV systolic (preload recruitable stroke work, Ees) and diastolic dysfunction (tau, arterial elastance). These changes were associated with an altered α/β-myosin heavy chain ratio. However, these changes were normalized to sham levels in long-term reversal rats (4-wk ACF + 11-wk reversal). Acute hemodynamic changes following ACF reversal improve LV geometry, but LV dysfunction persists. Gradual restoration of function was related to normalization of eccentric hypertrophy, LV wall stress, and ECM remodeling. These results suggest that mild to moderate LV systolic

  6. 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.

  7. Acute Effects of Eccentric Overload on Concentric Front Squat Performance.

    PubMed

    Munger, Cameron N; Archer, David C; Leyva, Whitney D; Wong, Megan A; Coburn, Jared W; Costa, Pablo B; Brown, Lee E

    2017-01-30

    Eccentric overload is used to enhance performance. The purpose of this study was to investigate the acute effects of eccentric overload on concentric front squat performance. Twenty resistance-trained males (age=23.80±1.82yrs, ht=176.95±5.21cm, mass=83.49±10.43kg, 1 Repetition Maximum [1RM] front squat=131.02±21.32kg) volunteered. A dynamic warm-up and warm-up sets of front squat were performed. Eccentric hooks were added to the barbell. They descended for 3 seconds, until eccentric hooks released, and performed the concentric phase as fast as possible. There were three randomly-ordered conditions with the concentric phase always at 90% 1RM and the eccentric phase at 105%, 110%, and 120% of 1RM. Two repetitions were performed for each condition. A repeated measures ANOVA was used to determine differences. For peak velocity, there were main effects for time and condition (P<0.05), where post (1.01±0.10m/s) was greater than pre (0.96±0.11m/s) and 120% (1.03±1.11m/s) was greater than 105% (0.99±0.13m/s). For peak power, there was a main effect for condition where 120% (2225.00±432.37W) was greater than 105% (2021.84±563.53W). For peak ground reaction force, there were main effects for time and condition, where post was greater than pre and 120% was greater than 105%. For rate of force development, there was no interaction or main effects. Eccentric overload enhanced concentric velocity and power, therefore it can be used by strength coaches and athletes during the power phase of a training program. It can also be used to prescribe supramaximal loads and could be a tool to supplement the clean exercise because the front squat is a precursor.

  8. Signs of left heart volume overload in severely anaemic cats.

    PubMed

    Wilson, Helen E; Jasani, Shailen; Wagner, Tobias B; Benigni, Livia; Milne, Joanna R; Stokes, Alison L; Luis-Fuentes, Virginia

    2010-12-01

    Anaemia induces haemodynamic compensatory mechanisms resulting in volume overload and increased left heart dimensions in humans and dogs. The aims of this retrospective study were to investigate the effects of anaemia on echocardiographic left heart dimensions, vertebral heart size (VHS) and radiographic evidence of congestive heart failure (CHF) in cats. Fifteen cats fulfilled the inclusion criteria and were classified as mildly anaemic (haematocrit (Hct)>18-24%) or severely anaemic (Hct≤18%). Eight out of eight severely anaemic cats had left atrial enlargement compared with 1/6 mildly anaemic cats (P<0.005) and severely anaemic cats also had a larger median left ventricular end-diastolic diameter (1.80cm versus 1.27cm, respectively; P<0.05). No difference was found between the groups in VHS or frequency of radiographic signs of CHF. Despite the small sample size, these preliminary findings suggest that severely anaemic cats are more likely to have enlarged left heart dimensions than mildly anaemic cats.

  9. 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.

  10. Response of various conduit arteries in tachycardia- and volume overload-induced heart failure.

    PubMed

    Lu, Xiao; Zhang, Zhen-Du; Guo, Xiaomei; Choy, Jenny Susana; Yang, Junrong; Svendsen, Mark; Kassab, Ghassan

    2014-01-01

    Although hemodynamics changes occur in heart failure (HF) and generally influence vascular function, it is not clear whether various HF models will affect the conduit vessels differentially or whether local hemodynamic forces or systemic factors are more important determinants of vascular response in HF. Here, we studied the hemodynamic changes in tachycardia or volume-overload HF swine model (created by either high rate pacing or distal abdominal aortic-vena cava fistula, respectively) on carotid, femoral, and renal arteries function and molecular expression. The ejection fraction was reduced by 50% or 30% in tachycardia or volume-overload model in four weeks, respectively. The LV end diastolic volume was increased from 65 ± 22 to 115 ± 78 ml in tachycardia and 67 ± 19 to 148 ± 68 ml in volume-overload model. Flow reversal was observed in diastolic phase in carotid artery of both models and femoral artery in volume-overload model. The endothelial function was also significantly impaired in carotid and renal arteries of tachycardia and volume-overload animals. The endothelial dysfunction was observed in femoral artery of volume-overload animals but not tachycardia animals. The adrenergic receptor-dependent contractility decreased in carotid and femoral arteries of tachycardia animals. The protein expressions of NADPH oxidase subunits increased in the three arteries and both animal models while expression of MnSOD decreased in carotid artery of tachycardia and volume-overload model. In conclusion, different HF models lead to variable arterial hemodynamic changes but similar vascular and molecular expression changes that reflect the role of both local hemodynamics as well as systemic changes in HF.

  11. Extracellular Matrix Remodeling During the Progression of Volume Overload-Induced Heart Failure

    PubMed Central

    Hutchinson, Kirk R.; Stewart, James A.; Lucchesi, Pamela A.

    2009-01-01

    Volume overload-induced heart failure results in progressive left ventricular remodeling characterized by chamber dilation, eccentric cardiac myocyte hypertrophy and changes in extracellular matrix (ECM) remodeling changes. The ECM matrix scaffold is an important determinant of the structural integrity of the myocardium and actively participates in force transmission across the LV wall. In response to this hemodynamic overload, the ECM undergoes a distinct pattern of remodeling that differs from pressure overload. Once thought to be a static entity, the ECM is now regarded to be a highly adaptive structure that is dynamically regulated by mechanical stress, neurohormonal activation, inflammation and oxidative stress, that result in alterations in collagen and other matrix components and a net change in matrix metalloproteinase (MMP) expression and activation. These changes dictate overall ECM turnover during volume overload hear failure progression. This review will discuss the cellular and molecular mechanisms that dictate the temporal patterns of ECM remodeling during heart disease progression. PMID:19524591

  12. Spautin-1 Ameliorates Acute Pancreatitis via Inhibiting Impaired Autophagy and Alleviating Calcium Overload

    PubMed Central

    Xiao, Juan; Feng, Xueping; Huang, Xiao-Ying; Huang, Zhongshi; Huang, Yanqiang; Li, Chaogan; Li, Genliang; Nong, Song; Wu, Ruoshi; Huang, Yongzhi; Long, Xi-Dai

    2016-01-01

    Acute pancreatitis is characterized by zymogen preactivation. Severe inflammation caused by zymogen activation can eventually lead to multiple organ dysfunctions which contribute to the high mortality rate of severe acute pancreatitis. However, there is no specific treatment available for acute pancreatitis therapy. Here, we show that spautin-1, which effectively inhibits autophagy flux, ameliorated the pathogenesis of acute pancreatitis induced by cerulein or L-arginine. CaMKII phosphorylation due to cytosolic calcium overload was revealed in this paper. It was also demonstrated that autophagic protein aggregates degradation blockade accompanied by impaired autophagy correlated positively with intra-acinar cell digestive aymogen activation stimulated by cerulein or L-arginine. The role of spautin-1 in ameliorating acute pancreatitis was shown here to be associated with impaired autophagy inhibition and Ca2+ overload alleviation. We provide a promising therapy for acute pancreatitis through targeting both impaired autophagy and increased cytosolic calcium. PMID:27579473

  13. Acute iron overload and oxidative stress in brain.

    PubMed

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

    2013-12-06

    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

  14. Temporal evaluation of left ventricular remodeling and function in rats with chronic volume overload.

    PubMed

    Brower, G L; Henegar, J R; Janicki, J S

    1996-11-01

    The left ventricle (LV) significantly dilates and hypertrophies in response to chronic volume overload. However, the temporal responses in LV mass, volume, and systolic/diastolic function secondary to chronic volume overload induced by an infrarenal arteriovenous (A-V) fistula in rats have not been well characterized. To this end, LV end-diastolic pressure, size, and function (i.e., isovolumetric pressure-volume relationships in the blood-perfused isolated heart) were assessed at 1, 2, 3, 5, and 8 wk post-A-V fistula and compared with age-matched control animals. Progressive hypertrophy (192% at 8 wk), ventricular dilatation (172% at 8 wk), and a decrease in ventricular stiffness (257% at 8 wk) occurred in the fistula groups. LV end-diastolic pressure increased from a control value of 4.2 +/- 3.1 mmHg to a peak value of 15.7 +/- 3.6 mmHg after 3 wk of volume overload. A subsequent decline in LVEDP to 11.0 +/- 6.0 mmHg together with further LV dilation (169%) corresponded to a significant decrease in LV stiffness (222%) at 5 wk post-A-V fistula. Myocardial contractility, as assessed by the isovolumetric pressure-volume relationship, was significantly reduced in all A-V fistula groups; however, the compensatory remodeling induced by 8 wk of chronic biventricular volume overload tended to preserve systolic function.

  15. Acute right ventricular pressure overload compromises left ventricular function by altering septal strain and rotation.

    PubMed

    Chua, Jason; Zhou, Wei; Ho, Jonathan K; Patel, Nikhil A; Mackensen, G Burkhard; Mahajan, Aman

    2013-07-15

    While right ventricular (RV) dysfunction has long been known to affect the performance of left ventricle (LV), the mechanisms remain poorly defined. Recently, speckle-tracking echocardiography has demonstrated that preservation of strain and rotational dynamics is crucial to both LV systolic and diastolic function. We hypothesized that alteration in septal strain and rotational dynamics of the LV occurs during acute RV pressure overload (RVPO) and leads to decreased cardiac performance. Seven anesthetized pigs underwent median sternotomy and placement of intraventricular pressure-volume conductance catheters. Two-dimensional echocardiographic images and LV pressure-volume loops were acquired for offline analysis at baseline and after banding of the pulmonary artery to achieve RVPO (>50 mmHg) induced RV dysfunction. RVPO resulted in a significant decrease (P < 0.05) in LV end-systolic elastance (50%), systolic change in pressure over change in time (19%), end-diastolic volume (22%), and cardiac output (37%) that correlated with decrease in LV global circumferential strain (58%), LV apical rotation (28%), peak untwisting (reverse rotation) rate (27%), and prolonged time to peak rotation (17%), while basal rotation was not significantly altered. RVPO reduced septal radial and circumferential strain, while no other segment of the LV midpapillary wall was affected. RVPO decreased septal radial strain on LV side by 27% and induced a negative radial strain from 28 ± 5 to -16 ± 2% on the RV side of the septum. The septal circumferential strain on both LV and RV side decreased by 46 and 50%, respectively, following RVPO (P < 0.05). Our results suggest that acute RVPO impairs LV performance by primarily altering septal strain and apical rotation.

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

    PubMed

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

    2010-02-01

    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.

  17. Iron overload in patients with acute leukemia or MDS undergoing myeloablative stem cell transplantation.

    PubMed

    Armand, Philippe; Kim, Haesook T; Rhodes, Joanna; Sainvil, Marie-Michele; Cutler, Corey; Ho, Vincent T; Koreth, John; Alyea, Edwin P; Hearsey, Doreen; Neufeld, Ellis J; Fleming, Mark D; Steen, Hanno; Anderson, Damon; Kwong, Raymond Y; Soiffer, Robert J; Antin, Joseph H

    2011-06-01

    Patients with hematologic malignancies undergoing allogeneic stem cell transplantation (HSCT) commonly have an elevated serum ferritin prior to HSCT, which has been associated with increased mortality after transplantation. This has led to the suggestion that iron overload is common and deleterious in this patient population. However, the relationship between serum ferritin and parenchymal iron overload in such patients is unknown. We report a prospective study of 48 patients with acute leukemia (AL) or myelodysplastic syndromes (MDS) undergoing myeloablative HSCT, using magnetic resonance imaging (MRI) to estimate liver iron content (LIC) and cardiac iron. The median (and range) pre-HSCT value of serum ferritin was 1549 ng/mL (20-6989); serum hepcidin, 59 ng/mL (10-468); labile plasma iron, 0 LPI units (0.0-0.9). Eighty-five percent of patients had hepatic iron overload (HIO), and 42% had significant HIO (LIC ≥5.0 mg/gdw). Only 1 patient had cardiac iron overload. There was a strong correlation between pre-HSCT serum ferritin and estimated LIC (r = .75), which was mostly dependent on prior transfusion history. Serum hepcidin was appropriately elevated in patients with HIO. Labile plasma iron elevation was rare. A regression calibration analysis supported the hypothesis that elevated pre-HSCT LIC is significantly associated with inferior post-HSCT survival. These results contribute to our understanding of the prevalence, mechanism, and consequences of iron overload in HSCT.

  18. 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

  19. Temporal evaluation of cardiac myocyte hypertrophy and hyperplasia in male rats secondary to chronic volume overload.

    PubMed

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

    2010-09-01

    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.

  20. Exposure to chronic alcohol accelerates development of wall stress and eccentric remodeling in rats with volume overload.

    PubMed

    Mouton, Alan J; Ninh, Van K; El Hajj, Elia C; El Hajj, Milad C; Gilpin, Nicholas W; Gardner, Jason D

    2016-08-01

    Chronic alcohol abuse is one of the leading causes of dilated cardiomyopathy (DCM) in the United States. Volume overload (VO) also produces DCM characterized by left ventricular (LV) dilatation and reduced systolic and diastolic function, eventually progressing to congestive heart failure. For this study, we hypothesized that chronic alcohol exposure would exacerbate cardiac dysfunction and remodeling due to VO. Aortocaval fistula surgery was used to induce VO, and compensatory cardiac remodeling was allowed to progress for either 3days (acute) or 8weeks (chronic). Alcohol was administered via chronic intermittent ethanol vapor (EtOH) for 2weeks before the acute study and for the duration of the 8week chronic study. Temporal alterations in LV function were assessed by echocardiography. At the 8week end point, pressure-volume loop analysis was performed by LV catheterization and cardiac tissue collected. EtOH did not exacerbate LV dilatation (end-systolic and diastolic diameter) or systolic dysfunction (fractional shortening, ejection fraction) due to VO. The combined stress of EtOH and VO decreased the eccentric index (posterior wall thickness to end-diastolic diameter ratio), increased end-diastolic pressure (EDP), and elevated diastolic wall stress. VO also led to increases in posterior wall thickness, which was not observed in the VO+EtOH group, and wall thickness significantly correlated with LV BNP expression. VO alone led to increases in interstitial collagen staining (picrosirius red), which while not statistically significant, tended to be decreased by EtOH. VO increased LV collagen I protein expression, whereas in rats with VO+EtOH, LV collagen I was not elevated relative to Sham. The combination of VO and EtOH also led to increases in LV collagen III expression relative to Sham. Rats with VO+EtOH had significantly lower collagen I/III ratio than rats with VO alone. During the acute remodeling phase of VO (3days), VO significantly increased collagen III

  1. Cardioprotective effects of lysyl oxidase inhibition against volume overload-induced extracellular matrix remodeling.

    PubMed

    El Hajj, Elia C; El Hajj, Milad C; Ninh, Van K; Gardner, Jason D

    2016-03-01

    A hallmark of heart failure (HF) is adverse extracellular matrix (ECM) remodeling, which is regulated by the collagen cross-linking enzyme, lysyl oxidase (LOX). In this study, we evaluate the efficacy of LOX inhibition to prevent adverse left ventricular (LV) remodeling and dysfunction using an experimental model of HF. Sprague-Dawley rats were subjected to surgically induced volume overload (VO) by creation of aortocaval fistula (ACF). A LOX inhibitor, beta-aminopropionitrile (BAPN; 100 mg/kg/day), was administered to rats with ACF or sham surgery at eight weeks postsurgery. Echocardiography was used to assess progressive alterations in cardiac ventricular structure and function. Left ventricular (LV) catheterization was used to assess alterations in contractility, stiffness, LV pressure and volume, and other indices of cardiac function. The LV ECM alterations were assessed by: (a) histological staining of collagen, (b) protein expression of collagen types I and III, (c) hydroxyproline assay, and (d) cross-linking assay. LOX inhibition attenuated VO-induced increases in cardiac stress, and attenuated increases in interstitial myocardial collagen, total collagen, and protein levels of collagens I and III. Both echocardiography and catheterization measurements indicated improved cardiac function post-VO in BAPN treated rats vs. untreated. Inhibition of LOX attenuated VO-induced decreases in LV stiffness and cardiac function. Overall, our data indicate that LOX inhibition was cardioprotective in the volume overloaded heart.

  2. 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.

  3. Cigarette smoke exacerbates ventricular remodeling and dysfunction in the volume overloaded heart.

    PubMed

    Bradley, Jessica M; Nguyen, Jonathan B; Fournett, Alyssa C; Gardner, Jason D

    2012-02-01

    Cigarette smoking is an independent risk factor for heart disease and is linked to sudden cardiac death. In this study, we examined the effects of cigarette smoke (CS) on the volume overload stressed heart. Our hypothesis was that CS exacerbates volume overload (VO)-induced cardiac dysfunction by accelerating ventricular remodeling. VO stress was surgically induced in male Sprague-Dawley rats by abdominal aortocaval fistula (ACF). Rats, with and without ACF, were exposed to either room air or CS (6 cigarettes/day) for 6 weeks. Temporal echocardiogram measurements indicated that CS significantly increased VO-induced left ventricular dilatation, prevented compensatory wall thickening, and depressed fractional shortening. Morphological analysis of ventricular collagen revealed that CS blunted compensatory collagen expression (45% decrease versus ACF alone). CS exacerbated the VO-induced increase of MMP-9 and TIMP-1 expression in the heart. CS also blocked the compensatory increases of HIF-1α, VEGF, and TGF-β in the VO-stressed heart. These data indicate that CS worsens VO remodeling by disrupting compensatory mechanisms, thereby promoting eccentric dilation and dysfunction.

  4. Fluid overload and survival in critically ill patients with acute kidney injury receiving continuous renal replacement therapy

    PubMed Central

    Kim, Il Young; Kim, Joo Hui; Lee, Dong Won; Lee, Soo Bong; Rhee, Harin; Seong, Eun Young; Kwak, Ihm Soo

    2017-01-01

    Background Fluid overload is known to be associated with increased mortality in patients with acute kidney injury (AKI) who are critically ill. In this study, we intended to uncover whether the adverse effect of fluid overload on survival could be applied to all of the patients with AKI who received continuous renal replacement therapy (CRRT). Methods We analyzed 341 patients with AKI who received CRRT in our intensive care units. The presence of fluid overload was defined as a minimum 10% increase in body weight from the baseline. Demographics, comorbid diseases, clinical data, severity of illness [the sequential organ failure assessment (SOFA) score, number of vasopressors, diagnosis of sepsis, use of ventilator] upon ICU admission, fluid overload status, and time elapsed from AKI diagnosis until CRRT initiation were reviewed from the medical charts. Results Patients with total fluid overload from 3 days before CRRT initiation to ICU discharge had a significantly lower survival rate after ICU admission, as compared to patients with no fluid overload (P < 0.001). Among patients with sepsis (P < 0.001) or with high SOFA scores (P < 0.001), there was a significant difference in survival of the patients with and without fluid overload. In patients without sepsis or with low SOFA score, there was no significant difference in survival of patients irrespective of fluid overload. Conclusion Our study demonstrates that the adverse effect of fluid overload on survival is more evident in patients with sepsis or with more severe illness, and that it might not apply to patients without sepsis or with less severe illness. PMID:28196107

  5. High levels of glucosamine-chondroitin sulfate can alter the cyclic preload and acute overload responses of chondral explants.

    PubMed

    Wei, Feng; Haut, Roger C

    2009-03-01

    A recent study by our laboratory showed that 14 days of low intensity, intermittent cyclic preloading of chondral explants elevated the concentration of proteoglycans (PGs) to cause a mechanical stiffening of the explants prior to an acute overload and limit the extent of tissue damage. Longer term loading to 21 days resulted in tissue degradation prior to the acute traumatic event and excessive damage from an acute overload. Previous studies by others showed that bathing chondral explants in a supplement of glucosamine-chondroitin sulfate (glcN-CS) upregulated the synthesis of tissue PGs, particularly in stressed tissue, and the supplement served as an anti-inflammatory agent. Our current hypothesis was that the supplementation of culture media with a high concentration of glcN-CS would upregulate the production of tissue PG and limit or mitigate long-term degradation of chondral explants under cyclic preloading and limit tissue damage in an acute overload. We showed that, in the presence of supplement, cyclic preloading significantly increased tissue PG content and matrix modulus by about 65 and 300%, respectively, at 21 days, resulting in a reduction of matrix damage and cell death following an acute overload. These data show a biological action of high concentrations of this supplement and its effect on the mechanical properties in this in vitro model.

  6. Maternal Cardiovascular Function in Normal Pregnancy: Evidence of Maladaptation to Chronic Volume Overload.

    PubMed

    Melchiorre, Karen; Sharma, Rajan; Khalil, Asma; Thilaganathan, Baskaran

    2016-04-01

    The aim of this study was to investigate cardiac functional status in pregnancy using a comprehensive approach taking into account the simultaneous changes in loading and geometry, as well as maternal age and anthropometric indices. This was a prospective cross-sectional study of 559 nulliparous pregnant women assessed at 4 time points during pregnancy and at 1 year postpartum. All women underwent conventional echocardiography and tissue Doppler velocities and strain rate analysis at multiple cardiac sites. Mean arterial pressure and total vascular resistance index significantly decreased (both P<0.001) during the first 2 trimesters of pregnancy and increased thereafter. Stroke volume index and cardiac index showed the opposite trend compared with mean arterial pressure and total vascular resistance index (both P<0.05). Myocardial and ventricular function were significantly enhanced in the first 2 trimesters but progressively declined thereafter. By the end of pregnancy, significant chamber diastolic dysfunction and impaired myocardial relaxation was evident in 17.9% and 28.4% of women, respectively, whereas myocardial contractility was preserved. There was full recovery of cardiac function at 1 year postpartum. Cardiovascular changes during pregnancy are thought to represent a physiological adaptation to volume overload. The findings of a drop in stroke volume index, impaired myocardial relaxation with diastolic dysfunction, and a tendency toward eccentric remodeling in a significant proportion of cases at term are suggestive of cardiovascular maladaptation to the volume-overloaded state in some apparently normal pregnancies. These unexpected cardiovascular findings have important implications for the management of both normal and pathological pregnancy states.

  7. Acute bovine laminitis: a new induction model using alimentary oligofructose overload.

    PubMed

    Thoefner, M B; Pollitt, C C; Van Eps, A W; Milinovich, G J; Trott, D J; Wattle, O; Andersen, P H

    2004-09-01

    Twelve dairy heifers were used to examine the clinical response of an alimentary oligofructose overload. Six animals were divided into 3 subgroups, and each was given a bolus dose of 13, 17, or 21 g/kg of oligofructose orally. The control group (n = 6) was sham-treated with tap water. Signs of lameness, cardiovascular function, and gastrointestinal function were monitored every 6 h during development of rumen acidosis. The heifers were euthanized 48 and 72 h after administration of oligofructose. All animals given oligofructose developed depression, anorexia, and diarrhea 9 to 39 h after receiving oligofructose. By 33 to 45 h after treatment, the feces returned to normal consistency and the heifers began eating again. Animals given oligofructose developed transient fever, severe metabolic acidosis, and moderate dehydration, which were alleviated by supportive therapy. Four of 6 animals given oligofructose displayed clinical signs of laminitis starting 39 to 45 h after receiving oligofructose and lasting until euthanasia. The lameness was obvious, but could easily be overlooked by the untrained eye, because the heifers continued to stand and walk, and did not interrupt their eating behavior. No positive pain reactions or lameness were seen in control animals. Based on these results, we conclude that an alimentary oligofructose overload is able to induce signs of acute laminitis in cattle. This model offers a new method, which can be used in further investigation of the pathogenesis and pathophysiology of bovine laminitis.

  8. Intestinal bacterial overgrowth includes potential pathogens in the carbohydrate overload models of equine acute laminitis.

    PubMed

    Onishi, Janet C; Park, Joong-Wook; Prado, Julio; Eades, Susan C; Mirza, Mustajab H; Fugaro, Michael N; Häggblom, Max M; Reinemeyer, Craig R

    2012-10-12

    Carbohydrate overload models of equine acute laminitis are used to study the development of lameness. It is hypothesized that a diet-induced shift in cecal bacterial communities contributes to the development of the pro-inflammatory state that progresses to laminar failure. It is proposed that vasoactive amines, protease activators and endotoxin, all bacterial derived bioactive metabolites, play a role in disease development. Questions regarding the oral bioavailability of many of the bacterial derived bioactive metabolites remain. This study evaluates the possibility that a carbohydrate-induced overgrowth of potentially pathogenic cecal bacteria occurs and that bacterial translocation contributes toward the development of the pro-inflammatory state. Two groups of mixed-breed horses were used, those with laminitis induced by cornstarch (n=6) or oligofructan (n=6) and non-laminitic controls (n=8). Cecal fluid and tissue homogenates of extra-intestinal sites including the laminae were used to enumerate Gram-negative and -positive bacteria. Horses that developed Obel grade2 lameness, revealed a significant overgrowth of potentially pathogenic Gram-positive and Gram-negative intestinal bacteria within the cecal fluid. Although colonization of extra-intestinal sites with potentially pathogenic bacteria was not detected, results of this study indicate that cecal/colonic lymphadenopathy and eosinophilia develop in horses progressing to lameness. It is hypothesized that the pro-inflammatory state in carbohydrate overload models of equine acute laminitis is driven by an immune response to the rapid overgrowth of Gram-positive and Gram-negative cecal bacterial communities in the gut. Further equine research is indicated to study the immunological response, involving the lymphatic system that develops in the model.

  9. [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.

  10. Energetics of acute pressure overload of the porcine right ventricle. In vivo 31P nuclear magnetic resonance.

    PubMed Central

    Schwartz, G G; Steinman, S; Garcia, J; Greyson, C; Massie, B; Weiner, M W

    1992-01-01

    In vivo 31P nuclear magnetic resonance (NMR) spectroscopy of the right ventricular (RV) free wall was employed to determine (a) whether phosphorus energy metabolites vary reciprocally with workload in the RV and (b) the mechanisms that limit RV contractile function in acute pressure overload. In 20 open-chest pigs, phosphocreatine (PCr)/ATP ratio (an index of energy metabolism inversely related to free ADP concentration), myocardial blood flow (microspheres), and segment shortening (sonomicrometry, n = 14) were measured at control (RV systolic pressure 31 +/- 1 mm Hg), and with pulmonary artery constriction to produce moderate pressure overload (RV systolic pressure 45 +/- 1 mm Hg), and maximal pressure overload before overt RV failure and systemic hypotension (RV systolic pressure 60 +/- 1 mm Hg). With moderate pressure overload, PCr/ATP declined to 89% of control (P = 0.01), while contractile function increased. Adenosine (n = 10, mean dose 0.16 mg/kg-min) increased RV blood flow by an additional 41% without increasing PCr/ATP, indicating that coronary reserve was not depleted and that the decrease in PCr/ATP from control was not due to ischemia. With maximal pressure overload and incipient RV failure, PCr/ATP fell further to 81% of control and RV blood flow did not increase further, even with adenosine. Thus: (a) The decline in PCr/ATP with moderate RV pressure overload, without evident ischemia or contractile dysfunction, supports the positive regulation of oxidative phosphorylation by ATP hydrolysis products. (b) Depletion of RV coronary flow reserve accompanies the onset of RV failure at maximal pressure overload. Images PMID:1541681

  11. Expression of Bax Protein and Morphological Changes in the Myocardium in Experimental Acute Pressure Overload of the Left Ventricle.

    PubMed

    Blagonravov, M L; Korshunova, A Yu; Azova, M M; Bryk, A A; Frolov, V A

    2016-06-01

    The expression of Bax protein, marker of intracellular pathway of apoptosis initiation, in viable left ventricular cardiomyocytes and morphological changes in the myocardium in acute pressure overload of the left ventricle were studied in experiment on male rabbits. The content of Bax protein in the cardiomyocyte cytoplasm decreased, this indicating that the mitochondrial pathway was not involved in the realization of the apoptotic program. This decrease was associated with manifest destructive changes in the left ventricular myocardium.

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

    PubMed Central

    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.

    2014-01-01

    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

  13. Overt expression of AP-1 reduces alpha myosin heavy chain expression and contributes to heart failure from chronic volume overload.

    PubMed

    Freire, Grace; Ocampo, Catherina; Ilbawi, Nadim; Griffin, Andrew J; Gupta, Madhu

    2007-10-01

    Reduced expression of alpha-MHC plays a significant role in cardiac contractile dysfunction from hemodynamic overload. Previously, Pur proteins and YY1 have been shown to play a role in alpha-MHC repression during heart failure induced by pressure overload and by spontaneous hypertension, respectively. This was not observed in volume-overload-induced heart failure, suggesting additional regulatory mechanisms for alpha-MHC repression. The present study was performed to identify volume overload responsive transcription factors involved in alpha-MHC gene regulation. DNA binding activity of several transcription factors was evaluated in a functionally characterized rat model of heart failure induced by aorto-caval shunt. After 10 weeks of shunt, severe LV dilatation and reduced LV function were accompanied by increased expression of ANF and beta-MHC, and decreased expression of alpha-MHC. This was associated with dramatic (10-fold) activation of AP-1 together with increased expression of c-fos and c-jun. AP-1 activation was not observed following 4 weeks of shunt when cardiac function was preserved. In cultured cardiomyocytes, induction of AP-1 by PMA attenuated alpha-MHC mRNA by 60%. Transient transfection assays mapped PMA responsive sequence to -582 to -588 bp of alpha-MHC promoter. Deletion or mutation of these nucleotides had minimal effect on basal promoter activity but played a dominant role in PMA-mediated repression of alpha-MHC promoter activity. Over-expression of c-fos and c-jun in cardiomyocytes inhibited alpha-MHC promoter activity in a concentration dependent manner. Data suggest a repressive role of AP-1 in alpha-MHC expression and its possible involvement in the transition from compensatory hypertrophy to heart failure in chronic volume overload.

  14. 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

  15. Increased fibroblast chymase production mediates procollagen autophagic digestion in volume overload

    PubMed Central

    Fu, Lianwu; Wei, Chih-Chang; Powell, Pamela C.; Bradley, Wayne E.; Ahmad, Sarfaraz; Ferrario, Carlos M.; Collawn, James F.; Dell’Italia, Louis J.

    2016-01-01

    Background Previous work has identified mast cells as the major source of chymase largely associated with a profibrotic phenotype. We recently reported increased fibroblast autophagic procollagen degradation in a rat model of pure volume overload (VO). Here we demonstrate a connection between increased fibroblast chymase production and autophagic digestion of procollagen in the pure VO of aortocaval fistula (ACF) in the rat. Methods and results Isolated LV fibroblasts taken from 4 and 12 week ACF Sprague–Dawley rats have significant increases in chymase mRNA and chymase activity. Increased intracellular chymase protein is documented by immunocytochemistry in the ACF fibroblasts compared to cells obtained from age-matched sham rats. To implicate VO as a stimulus for chymase production, we show that isolated adult rat LV fibroblasts subjected to 24 h of 20% cyclical stretch induces chymase mRNA and protein production. Exogenous chymase treatment of control isolated adult cardiac fibroblasts demonstrates that chymase is internalized through a dynamin-dependent mechanism. Chymase treatment leads to an increased formation of autophagic vacuoles, LC3-II production, autophagic flux, resulting in increased procollagen degradation. Chymase inhibitor treatment reduces cyclical stretch-induced autophagy in isolated cardiac fibroblasts, demonstrating chymase’s role in autophagy induction. Conclusion In a pure VO model, chymase produced in adult cardiac fibroblasts leads to autophagic degradation of newly synthesized intracellular procollagen I, suggesting a new role of chymase in extracellular matrix degradation. PMID:26807691

  16. 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

    2015-10-30

    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.

  17. Cardiac mast cell regulation of matrix metalloproteinase-related ventricular remodeling in chronic pressure or volume overload.

    PubMed

    Janicki, Joseph S; Brower, Gregory L; Gardner, Jason D; Forman, Mary F; Stewart, James A; Murray, David B; Chancey, Amanda L

    2006-02-15

    The chronic elevation in ventricular wall stress secondary to ventricular volume or pressure overload leads to structural remodeling of the muscular, vascular and extracellular matrix components of the myocardium. While initially a compensatory response, the progressive hypertrophy and ventricular dilatation induced by this condition ultimately have a detrimental effect on ventricular function, resulting in heart failure. Fibrillar collagen provides the skeletal framework which interconnects the cardiomyocytes, thereby maintaining ventricular shape and size and contributing to tissue stiffness. Accordingly, these myocardial collagen fibers must be disrupted for ventricular dilatation, sphericalization and wall thinning to occur. The presence of an abundant, latent matrix metalloproteinase (MMP) population which coexists with myocardial fibrillar collagen has been documented. Thus, the potential for collagen degradation to exceed synthesis exists should there be significant activation of this latent MMP system. Mast cells are known to store and release a variety of biologically active mediators including TNF-alpha and proteases such as tryptase and chymase, which can induce MMP activation. Increased cardiac mast cell density has been implicated in the pathophysiology of human end-stage cardiomyopathy and experimental myocardial infarction, hypertension and chronic volume overload secondary to mitral regurgitation and aorto-caval fistula. The potential role of cardiac mast cells in activating MMPs, which then results in fibrillar collagen degradation and adverse myocardial remodeling secondary to chronic volume and pressure overload will be the subject of this review.

  18. Temporal changes in integrin-mediated cardiomyocyte adhesion secondary to chronic cardiac volume overload in rats

    PubMed Central

    Stewart, James A.; Gardner, Jason D.; Brower, Gregory L.

    2013-01-01

    Previous studies have established integrins as cell surface receptors that mediate cardiomyocyte-extracellular matrix (ECM) attachments. This study sought to determine the contributions of the myocardial β1- and β3-integrin subunits to ventricular dilatation and coronary flow regulation using a blood-perfused isolated heart preparation. Furthermore, cardiomyocyte adhesion to collagen types I and IV, fibronectin, and laminin with and without a β1-integrin subunit neutralizing antibody was assessed during the course of remodeling secondary to a sustained cardiac volume overload, including the onset of heart failure. Isolated cardiomyocytes were obtained during the initial, compensated, and decompensated phases of remodeling resulting from an aortocaval fistula created in 8-wk-old male Sprague-Dawley rats. Blocking the β1-integrin subunit in isolated normal hearts produced ventricular dilatation, whereas this was not the case when the β3-subunit was blocked. Substantial reductions in cardiomyocyte adhesion coincided with the previously documented development of ventricular dilatation and decreased contractility postfistula, with the β1-integrin contribution to adhesion ranging from 28% to 73% over the course of remodeling being essentially substrate independent. In contrast, both integrin subunits were found to be involved in regulating coronary vascular resistance. It is concluded that marked reductions in integrin-mediated cardiomyocyte adhesion to the ECM play a significant role in the progression of adverse myocardial remodeling that leads to heart failure. Furthermore, although both the β1- and β3-integrin subunits were involved in regulating coronary vascular resistance, only inhibition of β1-integrin-mediated adhesion resulted in ventricular dilatation of the normal heart. PMID:24163072

  19. Time-dependent remodeling of transmural architecture underlying abnormal ventricular geometry in chronic volume overload heart failure.

    PubMed

    Ashikaga, Hiroshi; Omens, Jeffrey H; Covell, James W

    2004-11-01

    To test the hypothesis that the abnormal ventricular geometry in failing hearts may be accounted for by regionally selective remodeling of myocardial laminae or sheets, we investigated remodeling of the transmural architecture in chronic volume overload induced by an aortocaval shunt. We determined three-dimensional finite deformation at apical and basal sites in left ventricular anterior wall of six dogs with the use of biplane cineradiography of implanted markers. Myocardial strains at end diastole were measured at a failing state referred to control to describe remodeling of myofibers and sheet structures over time. After 9 +/- 2 wk (means +/- SE) of volume overload, the myocardial volume within the marker sets increased by >20%. At 2 wk, the basal site had myofiber elongation (0.099 +/- 0.030; P <0.05), whereas the apical site did not [P=not significant (NS)]. Sheet shear at the basal site increased progressively toward the final study (0.040 +/- 0.003 at 2 wk and 0.054 +/- 0.021 at final; both P <0.05), which contributed to a significant increase in wall thickness at the final study (0.181 +/- 0.047; P < 0.05), whereas the apical site did not (P=NS). We conclude that the remodeling of the transmural architecture is regionally heterogeneous in chronic volume overload. The early differences in fiber elongation seem most likely due to a regional gradient in diastolic wall stress, whereas the late differences in wall thickness are most likely related to regional differences in the laminar architecture of the wall. These results suggest that the temporal progression of ventricular remodeling may be anatomically designed at the level of regional laminar architecture.

  20. 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.

  1. [Volume assessment in the acute heart and renal failure].

    PubMed

    Vujicić, Bozidar; Ruzić, Alen; Zaputović, Luka; Racki, Sanjin

    2012-10-01

    Acute kidney injury (AKI) is an important clinical issue, especially in the setting of critical care. It has been shown in multiple studies to be a key independent risk factor for mortality, even after adjustment for demographics and severity of illness. There is wide agreement that a generally applicable classification system is required for AKI which helps to standardize estimation of severity of renal disfunction and to predict outcome associated with this condition. That's how RIFLE (Risk-Injury-Failure-Loss-End-stage renal disease), and AKIN (Acute Kidney Injury Network) classifications for AKI were found in 2004 and 2007, respectively. In the clinical setting of heart failure, a positive fluid balance (often expressed in the literature as weight gain) is used by disease management programs as a marker of heart failure decompensation. Oliguria is defined as urine output less than 0,3 ml/kg/h for at least 24 h. Since any delay in treatment can lead to a dangerous progression of the AKI, early recognition of oliguria appears to be crucial. Critically ill patients with oliguric AKI are at increased risk for fluid imbalance due to widespread systemic inflammation, reduced plasma oncotic pressure and increased capillary leak. These patients are particulary at risk of fluid overload and therefore restrictive strategy of fluid administration should be used. Objective, rapid and accurate volume assessment is important in undiagnosed patients presenting with critical illness, as errors may result in interventions with fatal outcomes. The historical tools such as physical exam, and chest radiography suffer from significant limitations. As gold standard, radioisolopic measurement of volume is impractical in the acute care enviroment. Newer technologies offer the promise of both rapid and accurate bedside estimation of volume status with the potential to improve clinical outcomes. Blood assessment with bioimpendance vector analysis, and bedside ultrasound seem to be

  2. 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

  3. Increased extracellular water measured by bioimpedance and by increased serum levels of atrial natriuretic peptide in RA patients-signs of volume overload.

    PubMed

    Straub, Rainer H; Ehrenstein, Boris; Günther, Florian; Rauch, Luise; Trendafilova, Nadezhda; Boschiero, Dario; Grifka, Joachim; Fleck, Martin

    2016-04-26

    The aim of the study is to investigate water compartments in patients with rheumatoid arthritis (RA). Acute inflammatory episodes such as infection stimulate water retention, chiefly implemented by the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis. This is an important compensatory mechanism due to expected water loss (sweating etc.). Since SNS and HPA axis are activated in RA, inflammation might be accompanied by water retention. Using bioimpedance analysis, body composition was investigated in 429 controls and 156 treatment-naïve RA patients between January 2008 and December 2014. A group of 34 RA patients was tested before and after 10 days of intensified therapy. Levels of pro-atrial natriuretic peptide (proANP) and expression of atrial natriuretic peptide in synovial tissue were investigated in 15 controls and 14 RA patients. Extracellular water was higher in RA patients than controls (mean ± SEM: 49.5 ± 0.3 vs. 36.7 ± 0.1, % of total body water, p < 0.0001). Plasma levels of proANP were higher in RA than controls. RA patients expressed ANP in synovial tissue, but synovial fluid levels and synovial tissue superfusate levels were much lower than plasma levels indicating systemic origin. Systolic/diastolic blood pressure was higher in RA patients than controls. Extracellular water levels did not change in RA patients despite 10 days of intensified treatment. This study demonstrates signs of intravascular overload in RA patients. Short-term intensification of anti-inflammatory therapy induced no change of a longer-lasting imprinting of water retention indicating the requirement of additional treatment. The study can direct attention to the area of volume overload.

  4. Hepcidin response to acute iron intake and chronic iron loading in dysmetabolic iron overload syndrome

    PubMed Central

    Trombini, Paola; Paolini, Valentina; Pelucchi, Sara; Mariani, Raffaella; Nemeth, Elizabeta; Ganz, Tomas; Piperno, Alberto

    2014-01-01

    Background The pathogenesis of dysmetabolic iron overload syndrome (DIOS) is still unclear. Hepcidin is the key regulator of iron homeostasis controlling iron absorption and macrophage release. Aim To investigate hepcidin regulation by iron in DIOS. Methods We analysed urinary hepcidin at baseline and 24 h after a 65 mg oral iron dose in 24 patients at diagnosis and after iron depletion (n=13) and compared data with those previously observed in 23 healthy controls. Serum iron indices, liver histology and metabolic data were available for all patients. Results At diagnosis, hepcidin values were significantly higher than in controls (P<0.001). After iron depletion, hepcidin levels decreased to normal values in all patients. At baseline, a significant response of hepcidin to iron challenge was observed only in the subgroup with lower basal hepcidin concentration (P=0.007). In iron-depleted patients, urinary hepcidin significantly increased after oral iron test (P=0.006). Conclusions Ours findings suggest that in DIOS, the progression of iron accumulation is counteracted by the increase in hepcidin production and progressive reduction of iron absorption, explaining why these patients develop a mild–moderate iron overload that tends to a plateau. PMID:21733088

  5. A comparative serial echocardiographic analysis of cardiac structure and function in rats subjected to pressure or volume overload.

    PubMed

    Cantor, Elliott J F; Babick, Andrea P; Vasanji, Zainisha; Dhalla, Naranjan S; Netticadan, Thomas

    2005-05-01

    Heart failure is a leading cause of death that is reaching epidemic proportions. It is a clinical syndrome attributable to a multitude of factors that begins with a compensatory response known as hypertrophy, followed by a decompensatory response that eventually results in failure. Heart failure can be triggered when the heart is subjected to extended periods of pathological pressure overload (PO) or volume overload (VO). To date there have been no comparative serial echocardiographic studies outlining the progression of hypertrophy in PO versus VO rats. We hypothesized that PO or VO would induce differential cardiac remodeling leading to contractile dysfunction with subsequent heart failure. To address this hypothesis we used echocardiography to study the serial progression of heart structure and function in rat models of both PO- and VO-induced hypertrophy. PO or VO were induced by performing abdominal aortic banding or aortocaval shunt procedures, respectively, while cardiac structure and function were assessed in both models by M-mode and Doppler echocardiography at key time intervals. PO rats showed progressive wall thickening consistent with concentric hypertrophy, while VO rats showed marked left ventricular dilatation consistent with eccentric hypertrophy. Systolic dysfunction occurred early in VO compared to PO. Diastolic dysfunction was evident in PO, while VO showed signs of enhanced diastolic function. PO and VO induced differential changes in cardiac structure and function during the progression of compensated hypertrophy to decompensated heart failure.

  6. Female rats with severe left ventricle volume overload exhibit more cardiac hypertrophy but fewer myocardial transcriptional changes than males.

    PubMed

    Beaumont, Catherine; Walsh-Wilkinson, Élisabeth; Drolet, Marie-Claude; Roussel, Élise; Arsenault, Marie; Couet, Jacques

    2017-04-07

    Aortic valve regurgitation (AR) imposes a volume overload (VO) to the left ventricle (LV). Male rats with a pathological heart overload usually progress more quickly towards heart failure than females. We examined whether a sexual dimorphism exists in the myocardial transcriptional adaptations to AR. Adult Wistar male and female rats either underwent a sham operation or were induced with AR and then followed for 26 weeks. Female AR rats gained relatively more LV mass than males (75 vs. 42%). They had a similar increase in LV chamber dimensions compared to males but more wall thickening. On the other hand, fatty acid oxidation (FAO)-related LV enzyme activity was only decreased in AR males. The expression of genes encoding FAO-related enzymes was only reduced in AR males and not in females. A similar situation was observed for the expression of genes involved in mitochondrial biogenesis or function as well as for genes encoding for transcription factors implicated in the control of bioenergetics and mitochondrial function (Errα, Errγ or Pgc1α). Although females develop more LV hypertrophy from severe VO, their myocardial gene expression remains closer to normal. This could provide survival benefits for females with severe VO.

  7. Work Overload.

    ERIC Educational Resources Information Center

    Bateman, Thomas S.

    1980-01-01

    To investigate managerial use of work (or role) overload to increase productivity, the author studied 77 nonclerical white-collar employees and found that work overload had negative effects on productivity, supervisors' ratings, employee attitudes, job satisfaction, and health. He recommends ways for managers and employees to reduce work overload.…

  8. Mean platelet volume in acute rheumatic fever.

    PubMed

    Sert, Ahmet; Aypar, Ebru; Odabas, Dursun

    2013-01-01

    Acute rheumatic fever (ARF) is still an endemic disease, especially among school-aged children in developing countries. Mean platelet volume (MPV), which is commonly used as a measure of platelet size, indicates the rate of platelet production and platelet activation. We aimed to investigate MPV in children with ARF. The study population consisted of 40 children with ARF (32 patients with carditis and 8 patients without carditis) and 40 healthy control subjects. White blood cell (WBC) and platelet counts were significantly higher and MPV values were significantly lower in patients with ARF during the acute stage when compared to controls. Erythrocyte sedimentation rate (ESR) and C-reactive protein values significantly decreased in patients with ARF after the treatment when compared to baseline, whereas MPV values increased. MPV values were negatively correlated with ESR and WBC, and platelet counts. In conclusion, during the acute stage of ARF, MPV values were lower when compared to controls.

  9. Extracellular Volume Overload and Increased Vasoconstriction in Patients With Recurrent Intradialytic Hypertension

    PubMed Central

    Van Buren, Peter Noel; Zhou, Yunyun; Neyra, Javier A.; Xiao, Guanghua; Vongpatanasin, Wanpen; Inrig, Jula; Toto, Robert

    2016-01-01

    Background/Aims Intradialytic hypertension (IH) occurs frequently in some hemodialysis patients and increases mortality risk. We simultaneously compared pre-dialysis, post-dialysis and changes in extracellular volume and hemodynamics in recurrent IH patients and controls. Methods We performed a case-control study among prevalent hemodialysis patients with recurrent IH and hypertensive hemodialysis controls. We used bioimpedance spectroscopy and impedance cardiography to compare pre-dialysis, post-dialysis, and intradialytic change in total body water (TBW) and extracellular water (ECW), as well as cardiac index (CI) and total peripheral resistance index (TPRI). Results The ECW/TBW was 0.453 (0.05) pre-dialysis and 0.427 (0.04) post-dialysis in controls vs. 0.478 (0.03) and 0.461 (0.03) in IH patients (p=0.01 post-dialysis). The ECW/TBW change was −0.027 (0.03) in controls and −0.013 (0.02) in IH patients (p=0.1). In controls, pre- and post-dialysis TPRI were 3254 (994) and 2469 (529) dynes/sec/cm2/m2 vs. 2983 (747) and 3408 (980) dynes/sec/cm2/m2 in IH patients (p=0.002 post-dialysis). There were between-group differences in TPRI change (0=0.0001), but not CI (p=0.09). Conclusions Recurrent intradialytic hypertension is associated with higher post-dialysis extracellular volume and TPRI. Intradialytic TPRI surges account for the vasoconstrictive state post-dialysis, but intradialytic fluid shifts may contribute to post-hemodialysis volume expansion. PMID:27832647

  10. 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

  11. Low Tidal Volume Ventilation in Patients Without Acute Lung Injury.

    PubMed

    Tang, Weibing; Wang, Zhi; Liu, Ye; Zhu, Jing

    2015-05-01

    Acute respiratory distress syndrome is a life threatening respiratory condition characterized by breakdown of the alveolar-capillary barrier, leading to flooding of the alveolar space producing the classical chest radiograph of bilateral pulmonary infiltrates. In this study, we employed lung protective ventilation strategies in patients without acute lung injury (ALI) to determine whether mechanical ventilation with lower tidal volume would provide more clinical benefits to patients without ALI.

  12. Modelling Systemic Iron Regulation during Dietary Iron Overload and Acute Inflammation: Role of Hepcidin-Independent Mechanisms

    PubMed Central

    Sparla, Richard; Hahnel, Maximilian; Bode, Johannes; Muckenthaler, Martina U.; Legewie, Stefan

    2017-01-01

    Systemic iron levels must be maintained in physiological concentrations to prevent diseases associated with iron deficiency or iron overload. A key role in this process plays ferroportin, the only known mammalian transmembrane iron exporter, which releases iron from duodenal enterocytes, hepatocytes, or iron-recycling macrophages into the blood stream. Ferroportin expression is tightly controlled by transcriptional and post-transcriptional mechanisms in response to hypoxia, iron deficiency, heme iron and inflammatory cues by cell-autonomous and systemic mechanisms. At the systemic level, the iron-regulatory hormone hepcidin is released from the liver in response to these cues, binds to ferroportin and triggers its degradation. The relative importance of individual ferroportin control mechanisms and their interplay at the systemic level is incompletely understood. Here, we built a mathematical model of systemic iron regulation. It incorporates the dynamics of organ iron pools as well as regulation by the hepcidin/ferroportin system. We calibrated and validated the model with time-resolved measurements of iron responses in mice challenged with dietary iron overload and/or inflammation. The model demonstrates that inflammation mainly reduces the amount of iron in the blood stream by reducing intracellular ferroportin transcription, and not by hepcidin-dependent ferroportin protein destabilization. In contrast, ferroportin regulation by hepcidin is the predominant mechanism of iron homeostasis in response to changing iron diets for a big range of dietary iron contents. The model further reveals that additional homeostasis mechanisms must be taken into account at very high dietary iron levels, including the saturation of intestinal uptake of nutritional iron and the uptake of circulating, non-transferrin-bound iron, into liver. Taken together, our model quantitatively describes systemic iron metabolism and generated experimentally testable predictions for additional

  13. Acute pulmonary inflammation induced by lung overloading with selenium particles: leukocyte response and in situ detection of selenium at high resolution.

    PubMed

    Cherdwongcharoensuk, Duangrudee; Upatham, Suchart; Pereira, António Sousa; Aguas, Artur P

    2004-12-15

    The kinetics of the acute inflammatory response of the lung was triggered in CD-1 mice by a single intratracheal instillation of a large amount of Se (10 mg); it was studied by quantitative cytology of bronchoalveolar lavage samples, light microscopy, and scanning electron microscopy coupled with x-ray elemental microanalysis. Bronchoalveolar lavage leukocytes were mostly neutrophils and increased from 12 to 24 h of Se treatment and decreased at 72 h. Only less than half of the granulocytes showed ingested Se particles; in contrast, virtually all BAL macrophages contained Se particles. Scanning electron microscopy coupled with X-ray elemental microanalysis revealed that the intracellular Se particles were heterogeneous in size (diameters from 0.4 and up to 14 microm), and that Se inclusions were sometimes accumulated at a pole of the cell. At 72 h after instillation of the particles, Se-loaded alveolar macrophages were migrated in the interstitial space of the alveoli. Se-positive regions had a focal distribution in the lung; accumulation of inflammatory cells erased the alveolar architecture of these areas of the deep lung. Our data indicates that Se overloading of the lung results in: (1) an acute inflammatory response that is dominated by neutrophils; (2) early removal of Se done mostly by alveolar macrophages, and (3) formation of focal areas of invasion of the lung parenchyma by inflammatory infiltrates.

  14. Cancer-selective cytotoxic Ca2+ overload in acute myeloid leukemia cells and attenuation of disease progression in mice by synergistically acting polyphenols curcumin and carnosic acid

    PubMed Central

    Pesakhov, Stella; Nachliely, Matan; Barvish, Zeev; Aqaqe, Nasma; Schwartzman, Bar; Voronov, Elena; Sharoni, Yoav; Studzinski, George P.; Fishman, Daniel; Danilenko, Michael

    2016-01-01

    Acute myeloid leukemia (AML) is an aggressive hematologic malignancy characterized by extremely heterogeneous molecular and biologic abnormalities that hamper the development of effective targeted treatment modalities. While AML cells are highly sensitive to cytotoxic Ca2+ overload, the feasibility of Ca2+- targeted therapy of this disease remains unclear. Here, we show that apoptotic response of AML cells to the synergistically acting polyphenols curcumin (CUR) and carnosic acid (CA), combined at low, non-cytotoxic doses of each compound was mediated solely by disruption of cellular Ca2+ homeostasis. Specifically, activation of caspase cascade in CUR+CA-treated AML cells resulted from sustained elevation of cytosolic Ca2+ (Ca2+cyt) and was not preceded by endoplasmic reticulum stress or mitochondrial damage. The CUR+CA-induced Ca2+cyt rise did not involve excessive influx of extracellular Ca2+ but, rather, occurred due to massive Ca2+ release from intracellular stores concomitant with inhibition of Ca2+cyt extrusion through the plasma membrane. Notably, the CUR+CA combination did not alter Ca2+ homeostasis and viability in non-neoplastic hematopoietic cells, suggesting its cancer-selective action. Most importantly, co-administration of CUR and CA to AML-bearing mice markedly attenuated disease progression in two animal models. Collectively, our results provide the mechanistic and translational basis for further characterization of this combination as a prototype of novel Ca2+-targeted pharmacological tools for the treatment of AML. PMID:26870993

  15. Left and right ventricular function and volume assessment in young thalassemia major patients with no related myocardial iron overload.

    PubMed

    Fernandes, Juliano L; Silveira, Matheus A; Fertrin, Kleber; Lauar, Samira; Fattori, Andre; Coelho, Otavio; Junqueira, Flavia Pegado; da Cunha, Guilherme Moura; Coutinho, Antonio Carlos; Pereira, Fabricio B; Verissimo, Monica; Saad, Sara T

    2012-12-01

    Thalassemia major (TM) patients have altered ventricular volumes and ejection fraction compared to normals, although evidence for these findings stem from restricted patient groups and has never been reproduced. We sought to evaluate cardiac parameters by cardiovascular magnetic resonance (CMR) in a group of young TM patients not covered by previous studies that are more representative of the TM population in many countries. Seventy patients including 40 TM with normal myocardial iron concentrations, and 30 age- and gender-matched normal (NL) volunteers underwent a CMR study for assessment of left and right ventricle volumes and function using a 1.5-T scanner. Left and right ventricle ejection fraction, indexed systolic and diastolic volumes, and indexed mass were compared between the two groups. Mean age of TM patients was 18.2 ± 7.1 versus 17.5 ± 8.5 years in NL with no significant differences (P = 0.73). There was no difference in left ventricular (LV) ejection fraction between the groups (TM 64.9 ± 5.7 %, NL 64.9 ± 5.2 %; P = 0.97). LV normalized end-diastolic and end-systolic volumes were significantly higher in patients with TM compared to NL volunteers (76.8 ± 19.4 versus 66.6 ± 11.7 mL/m², P = 0.008, and 27.0 ± 8.8 versus 23.6 ± 5.0 mL/m², P = 0.045). LV indexed mass was also higher in TM patients compared to NL (51.2 ± 11.9 versus 42.0 ± 8.5 g/m², P < 0.001). No significant differences were observed in right ventricular parameters. In conclusion, younger patients with TM do not present different left or right ventricular function values compared to normal controls despite having increased left ventricular volumes and mass.

  16. Polysynovitis after oligofructose overload in dairy cattle.

    PubMed

    Danscher, A M; Enemark, H L; Andersen, P H; Aalbaek, B; Nielsen, O L

    2010-01-01

    Acute bovine laminitis is a systemic disease with local manifestations primarily affecting the claws. However, distension of the tarsocrural joints has been observed after experimental oligofructose overload in dairy heifers as a part of the complex interpreted as acute, clinical laminitis. Therefore, the aim of the present study was to study bovine synovial joints and tendon sheaths after oligofructose overload. Ten dairy heifers received oral oligofructose overload (17 g/kg body weight); four were killed 24h after overload and six after 72 h. Six control heifers received tap water and were killed after 72 or 96 h. Clinical examination included locomotion scoring and palpation of the tarsocrural joints. Ruminal fluid and blood was collected for measurements of pH and hydration status. Total protein concentrations and white blood cell (WBC) counts were determined in synovial fluid collected from tarsocrural joints after death. Synovial joints and tendon sheaths were examined and synovial membranes were studied microscopically. Swabs taken from the synovial cavities were subject to bacteriological culture. Heifers with oligofructose overload developed signs of ruminal and systemic acidosis. Lameness was observed in three of ten heifers 24h after overload and in all remaining heifers after 72 h. Distension of tarsocrural joints was observed from 18 h after overload and peaked at 30 h when all examined joints were moderately or severely distended. The synovial fluid was turbid and protein content and WBC counts were increased at both 24 and 72 h compared with controls. Bacterial culture was negative. Synovial membranes 24 and 72 h after overload had a fibrinous and neutrophil inflammatory reaction that regressed in severity between 24 and 72 h after overload. Heifers subjected to oligofructose overload therefore developed generalized sterile neutrophilic polysynovitis. Focus on this aspect of bovine laminitis may shed new light on the pathogenesis of this complex

  17. Transcriptional Changes Associated with Long-Term Left Ventricle Volume Overload in Rats: Impact on Enzymes Related to Myocardial Energy Metabolism

    PubMed Central

    Roussel, Elise; Drolet, Marie-Claude; Walsh-Wilkinson, Elisabeth; Dhahri, Wahiba; Lachance, Dominic; Gascon, Suzanne; Sarrhini, Otman; Rousseau, Jacques A.; Lecomte, Roger; Couet, Jacques; Arsenault, Marie

    2015-01-01

    Patients with left ventricle (LV) volume overload (VO) remain in a compensated state for many years although severe dilation is present. The myocardial capacity to fulfill its energetic demand may delay decompensation. We performed a gene expression profile, a model of chronic VO in rat LV with severe aortic valve regurgitation (AR) for 9 months, and focused on the study of genes associated with myocardial energetics. Methods. LV gene expression profile was performed in rats after 9 months of AR and compared to sham-operated controls. LV glucose and fatty acid (FA) uptake was also evaluated in vivo by positron emission tomography in 8-week AR rats treated or not with fenofibrate, an activator of FA oxidation (FAO). Results. Many LV genes associated with mitochondrial function and metabolism were downregulated in AR rats. FA β-oxidation capacity was significantly impaired as early as two weeks after AR. Treatment with fenofibrate, a PPARα agonist, normalized both FA and glucose uptake while reducing LV dilation caused by AR. Conclusion. Myocardial energy substrate preference is affected early in the evolution of LV-VO cardiomyopathy. Maintaining a relatively normal FA utilization in the myocardium could translate into less glucose uptake and possibly lesser LV remodeling. PMID:26583150

  18. Chronic left atrial volume overload abbreviates the action potential duration of the canine pulmonary vein myocardium via activation of IK channel.

    PubMed

    Nouchi, Hideaki; Takahara, Akira; Nakamura, Hideki; Namekata, Iyuki; Sugimoto, Takahiko; Tsuneoka, Yayoi; Takeda, Kiyoshi; Tanaka, Toshikazu; Shigenobu, Koki; Sugiyama, Atsushi; Tanaka, Hikaru

    2008-11-12

    Electrophysiological properties of the pulmonary vein myocardium were assessed in a canine chronic atrioventricular block model resulting in left atrial volume overload. Five chronic atrioventricular block dogs and five sham-operated dogs were used. The heart was removed two months after a surgical procedure causing atrioventricular block, when atrial structural remodeling was established. Standard microelectrode penetrations were made with glass microelectrodes to obtain action potential signals of left atrium and pulmonary vein myocardia. The resting membrane potential in the pulmonary vein was more positive than that in the left atrium (-69 mV vs -74 mV) in both animal groups. The action potential duration at 50% repolarization of the pulmonary vein was shorter in the chronic atrioventricular block dogs than in the sham-operated dogs (38 ms vs 63 ms), whereas no significant difference was detected in the action potential duration of the left atrium between the two animal groups (67 ms vs 61 ms). The action potential duration of the pulmonary vein in the chronic atrioventricular block dogs was prolonged by charybdotoxin but not by iberiotoxin. Such prolongation was not observed in the normal pulmonary vein. These results suggest that long-term left atrial dilatation shortened the action potential duration of pulmonary vein myocardium, which may be associated with activation of the intermediate conductance Ca2+-activated K+ channel (IK channel).

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

    PubMed

    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; Gamboa, Alfredo

    2014-09-15

    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 (VO2peak) in POTS. Nineteen patients with POTS participated in a sequential study. VO2peak was measured on two separate study days, following administration of placebo or 1 liter of i.v. 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/cm(5) vs. placebo 1,184.0 ± 50.8 dyn-s/cm(5); P = 0.011), with no effect on HR or blood pressure. During exercise, saline did not produce differences in VO2peak (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 VO2peak or cardiovascular responses to exercise in POTS, despite improvements in resting hemodynamic function.

  20. Fatigue Crack Growth and Retardation Due to Overloads in Metal-matrix Composites Volume I. Fatigue Crack Growth In Boron-Aluminum Metal-Matrix Composites

    DTIC Science & Technology

    1986-08-01

    a - 9313 psi, R a 0.01. (c) Specimen A13 - a - 9313 psi, R - 0.01. (d) Specimen C1 - a= 5780 psi, R = 0.04. (e) Specimen C4 - ao = 5780 psi, R...psi, R - 0.01, 1.5x overload (b) Specimen A12 - Ao = 9313 psi, R - 0.01, 1.5x overload (c) Specimen A13 - ac - 9313 psi, R a 0.01, 2.Ox overload (d...and R2 , R3 , and R fixed reduces (2.7) to: &E a 1(2.8) The strain is computed from: ea - j 1=4 g (2.9) where Sg a gage factor A series of loadings were

  1. 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.

  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 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.

  3. 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.

  4. 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 ...

  5. Cognitive reserve and brain volumes in pediatric acute lymphoblastic leukemia

    PubMed Central

    Kesler, Shelli R.; Tanaka, Hiroko; Koovakkattu, Della

    2011-01-01

    Acute lymphoblastic leukemia (ALL) is associated with long-term, progressive cognitive deficits and white matter injury. We measured global and regional white and gray matter as well as cognitive function and examined relationships between these variables and cognitive reserve, as indicated by maternal education level, in 28 young survivors of ALL and 31 healthy controls. Results indicated significantly reduced white matter volumes and cognitive testing scores in the ALL group compared to controls. Maternal education was inversely related to both global and regional white matter and directly related to gray matter in ALL and was directly related to both gray and white matter in controls, consistent with the cognitive reserve hypothesis. Cognitive performance was associated with different brain regions in ALL compared to controls. Maternal education was significantly positively correlated with working and verbal memory in ALL as well as processing speed and verbal memory in controls, improving models of cognitive outcome over medical and/or demographic predictors. Our findings suggest that cognitive reserve may be an important factor in brain injury and cognitive outcome in ALL. Additionally, children with ALL may experience some neural reorganization related to cognitive outcome. PMID:20814845

  6. 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.

  7. Cardioprotective effects of sarcolemmal and mitochondrial K-ATP channel openers in an experimental model of autoimmune myocarditis. Role of the reduction in calcium overload during acute heart failure.

    PubMed

    Niwano, Shinichi; Hirasawa, Shoji; Niwano, Hiroe; Sasaki, Sae; Masuda, Ray; Sato, Kiyotaka; Masuda, Takashi; Izumi, Tohru

    2012-01-01

    It has been reported that K-ATP channel openers have a cardioprotective effect in acute ischemia as a pharmacological preconditioning effect. In the present study, the chronic effects of clinical K-ATP channel openers, ie, nicorandil (Nic) and mexiletine (Mex), on cardiac function were evaluated in a rat model of experimental autoimmune myocarditis (EAM). Nicorandil (3 or 10 mg/kg/day) or Mex (10 or 25 mg/kg/day) was administered to the EAM rats, and the effects were compared with those in untreated EAM rats (control EAM) and sham rats without EAM on day 21 (acute phase) or day 60 (chronic phase). In the acute phase, the control EAM rats exhibited a reduced left ventricular ejection fraction (LVEF) and prolonged monophasic action potential duration (MAPD). Neither drug had an affect on the LVEF or degree of myocarditis, but Mex 25 mg suppressed the MAPD prolongation. In the chronic phase, EAM+Nic and EAM+Mex 25 mg exhibited a higher LVEF than the control EAM. Although the control EAM exhibited sustained MAPD prolongation, the other groups showed recovery of the MAPD in the chronic phase. The mitochondorial redox state was lower in the control EAM than in the sham, and EAM+Nic exhibited a similar level of the redox state as the sham in the chronic phase. Nicorandil exhibited a cardioprotective effect through the protection of mitochondrial function. Mexiletine exhibited a cardioprotective effect possibly through a reduction in the calcium overload by shortening the MAPD in the acute phase.

  8. Oligofructose overload induces lameness in cattle.

    PubMed

    Danscher, A M; Enemark, J M D; Telezhenko, E; Capion, N; Ekstrøm, C T; Thoefner, M B

    2009-02-01

    The aim was to describe the clinical orthopedic implications of oligofructose overload. A group of 8 nonpregnant dairy heifers were given an oral dose of oligofructose (17 g/kg of body weight). At predefined times during a period spanning 3 d before and 9 d after oligofructose overload, the heifers underwent a clinical examination including locomotion scoring, hoof-testing, and palpation of tarso-crural joints, as well as the collection of blood and ruminal fluid samples. Locomotion sessions were videotaped; subsequently, locomotion was blind-scored. Locomotion scores increased after oligofructose overload and declined toward the end of the study period. The greatest locomotion scores were recorded on d 3 to 5 (60 to 120 h) where 12 of 42 (29%) locomotion scores were 3 and 13 of 42 (32%) were score 2. Positive reactions to hoof-testing were observed from 30 h after oligofructose overload and reached a maximum on d 7 and 9 where 12 of 28 (43%) reactions were marked positive. Distension of the tarso-crural joints was observed from 24 h after oligofructose overload, with maximum distension being observed on d 2, in which 44 of 56 (79%) of observed joints were either moderately or severely distended. The heifers developed classic signs of acute ruminal and systemic acidosis after the oligofructose overload (ruminal pH 4.3 +/- 0.07, standard base excess -10.8 +/- 2.3 at 18 h). With few exceptions, clinical and laboratory variables returned to normal within 9 d of oligofructose overload. But, good body condition and previous feeding with grass apparently predisposed the heifers to more severe systemic affection. Oligofructose overload in dairy heifers induced ruminal and systemic acidosis, diarrhea, dehydration, and, subsequently, lameness, claw pain, and joint effusion, collectively interpreted as signs of acute laminitis. Oligofructose overload at 17 g/kg of body weight represented a relatively mild laminitis model in cattle, as demonstrated by a reasonably quick

  9. 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. PMID:27326224

  10. Proteomic and transcriptomic analysis of heart failure due to volume overload in a rat aorto-caval fistula model provides support for new potential therapeutic targets - monoamine oxidase A and transglutaminase 2

    PubMed Central

    2011-01-01

    Background Chronic hemodynamic overloading leads to heart failure (HF) due to incompletely understood mechanisms. To gain deeper insight into the molecular pathophysiology of volume overload-induced HF and to identify potential markers and targets for novel therapies, we performed proteomic and mRNA expression analysis comparing myocardium from Wistar rats with HF induced by a chronic aorto-caval fistula (ACF) and sham-operated rats harvested at the advanced, decompensated stage of HF. Methods We analyzed control and failing myocardium employing iTRAQ labeling, two-dimensional peptide separation combining peptide IEF and nano-HPLC with MALDI-MS/MS. For the transcriptomic analysis we employed Illumina RatRef-12v1 Expression BeadChip. Results In the proteomic analysis we identified 2030 myocardial proteins, of which 66 proteins were differentially expressed. The mRNA expression analysis identified 851 differentially expressed mRNAs. Conclusions The differentially expressed proteins confirm a switch in the substrate preference from fatty acids to other sources in the failing heart. Failing hearts showed downregulation of the major calcium transporters SERCA2 and ryanodine receptor 2 and altered expression of creatine kinases. Decreased expression of two NADPH producing proteins suggests a decreased redox reserve. Overexpression of annexins supports their possible potential as HF biomarkers. Most importantly, among the most up-regulated proteins in ACF hearts were monoamine oxidase A and transglutaminase 2 that are both potential attractive targets of low molecular weight inhibitors in future HF therapy. PMID:22078724

  11. 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.

  12. 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…

  13. Acute leg volume changes in weightlessness and its simulation

    NASA Technical Reports Server (NTRS)

    Thornton, William E.; Uri, John J.; Hedge, Vickie; Coleman, Eugen; Moore, Thomas P.

    1992-01-01

    Leg volume changes were studied in six subjects during 150 min of horizontal, 6 deg headdown tilt and supine immersion. Results were compared to previously obtained space flight data. It is found that, at equivalent study times, the magnitude of the leg volume changes during the simulations was less than one half that seen during space flight. Relative and absolute losses from the upper leg were greater during space flight, while relative losses were greater from the lower leg during simulations.

  14. 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

  15. Preliminary Assessment of Tricuspid Valve Annular Velocity Parameters by Cardiac Magnetic Resonance Imaging in Adults with a Volume-Overloaded Right Ventricle: Comparison of Unrepaired Atrial Septal Defect and Repaired Tetralogy of Fallot.

    PubMed

    Ito, Seiji; McElhinney, Doff B; Adams, Robert; Bhatla, Puneet; Chung, Sohae; Axel, Leon

    2015-08-01

    The aim is to compare tricuspid valve (TV) atrioventricular junction (AVJ) annular motion parameters in unrepaired atrial septal defect (ASD) and repaired Tetralogy of Fallot (TOF) by cardiac magnetic resonance (CMR) imaging. We retrospectively reviewed CMR studies performed between November 2007 and November 2013 in patients 16-45 years of age with unrepaired ASD (with or without partial anomalous pulmonary venous return) and with repaired TOF, who had previous infundibulotomy, but have not undergone pulmonary valve replacement. Longitudinal motion of lateral TV in four-chamber view cine image was tracked through the cardiac cycle with custom software. Twenty TOF patients and 12 ASD patients were included, and values were compared with 80 controls. Right ventricular end-diastolic volume index and right ventricular end-systolic volume index were similar in the ASD and TOF groups and were significantly higher in both groups than in controls. Maximum displacement of the TV in systole, velocity at half-maximal displacement during systole, and velocity at half-maximal displacement during early diastole were all significantly lower in the TOF group than the ASD group [1.39 ± 0.47 vs. 2.21 ± 0.46 (cm, p < 0.01), 5.9 ± 2.1 vs. 10.1 ± 2.3 (cm/s, p < 0.01), and 7.7 ± 2.6 vs. 10.9 ± 3.1 (cm/s, p < 0.05)]. TOF patients have diminished early diastolic TV AVJ velocity compared to patients with an unrepaired ASD, despite similar RV volumes. This observation could suggest diastolic dysfunction or cardiac mechanics unique to the postoperative, volume-overloaded right ventricle in patients with repaired TOF.

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

    PubMed

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

    2015-07-31

    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, 30nL, are improved when using TASF. TASF is very effective at reducing the detrimental effects of pre-column 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.

  17. Change in plasma volume and prognosis in acute decompensated heart failure: an observational cohort study

    PubMed Central

    Hudson, Sarah R; Chan, Daniel

    2016-01-01

    Objectives This study aimed to develop an inexpensive, readily available prognostic indicator in acute decompensated heart failure patients to guide management and improve outcome. Prognostic biomarkers for heart failure exist but are expensive and not routinely performed. Increasing plasma volume has been associated with worse outcomes. Setting UK University Teaching Hospital. Design Observational Cohort study. Participants 967 patients with acute decompensated heart failure. Methods Haemoglobin and haematocrit were measured at admission and discharge and were used to calculate the plasma volume change using the Strauss-Davis-Rosenbaum formula. Main outcome measures Endpoints were death and the composite of death and/or heart failure hospitalisation. Change in plasma volume was added to ADHERE scoring to determine predictive value. Results During follow-up, 536 died and 626 died or were hospitalised with heart failure. Multivariable Cox models showed change in plasma volume was an independent predictor of mortality (hazard ratio (HR) [95% confidence interval (CI)]: 1.150 [1.031–1.283], p = 0.012) and death or heart failure hospitalisation (HR: 1.138 [1.029–1.259], p = 0.012). Kaplan–Meier analysis of change in plasma volume tertiles for outcome measures showed significant difference for the top tertile compared to the lower two. Multivariable analysis of change in plasma volume with ADHERE scoring showed change in plasma volume change remained an independent predictor of death (HR: 1.138 [1.026–1.261], p = 0.015) and death or heart failure hospitalisation (HR: 1.129 [1.025–1.243], p = 0.014). Conclusions Change in plasma volume over an admission can be used for prognostication and adds value to the ADHERE score. Change in plasma volume can be easily and inexpensively calculated from routine blood tests. Clinically, this may facilitate targeted treatment of acute decompensated heart failure patients at greatest risk. PMID:27609799

  18. 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

  19. How will you need me, how will you read me, when I'm 64 (or more!)?: volume computed tomographic scanning and information overload in the emergency department.

    PubMed

    Chason, David P; Anderson, Jon A; Stephens, Jason S; Suss, Richard A; Guild, Jeffrey B; Blackburn, Timothy J; Champine, Julie G; Lane, Thomas J

    2010-01-01

    Computed tomographic (CT) scanning technology now employs up to 320 detector rows of 0.5-mm width and allows rapid acquisition of isotropic volume datasets over the entire body. Data from a single CT acquisition can be reconstructed into image series that would formerly have required multiple acquisitions. Small isotropic voxels permit scan parameters to be general while reconstruction algorithms remain specific to anatomy. While this results in more efficient operation in the Emergency Department, it necessitates new ways of displaying, interpreting, and archiving the information. Critical decisions include how much of the patient to scan and how to time contrast injections when imaging multiple organs. These choices must be made in light of dose considerations to the patient and the general population of patients. The technical basis of high-density CT scanning is discussed, including detector configurations and reconstruction techniques. Volumetric scanning in the Emergency Department can improve patient care but requires a change of technical habits.

  20. 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)

  1. Dietary Soy May Not Confound Acute Experimental Stroke Infarct Volume Outcomes In Ovariectomized Female Rats

    PubMed Central

    Prongay, Kamm D.; Lewis, Anne D.; Hurn, Patricia D.; Murphy, Stephanie J.

    2009-01-01

    Estrogen administration can alter experimental stroke outcomes. Soy as a source of phytoestrogens may therefore modulate responses in “estrogen-sensitive” stroke models, thus potentially confounding results. We evaluated the effects of dietary soy on acute infarct volumes in a pilot study using a rat focal stroke model. We hypothesized that ovariectomized (OVX) rats fed a soy-rich diet would have smaller acute infarct volumes than rats fed a soy-free diet. OVX rats were randomly assigned to a soy-free (n=6) or a soy-rich (n=6) diet for 4 weeks and weighed weekly. Following the dietary trial, rats underwent 2 hours of middle cerebral artery occlusion (MCAO). Mean arterial blood pressure, rectal and temporalis muscle temperatures, arterial blood gases, and blood glucose were recorded peri-ischemia. Rats were euthanized 22 hours following 2 hours of MCAO. Brains were stained with 2,3,5-triphenyl tetrazolium chloride for acute infarct volume analysis. Uterine weight and histology were also evaluated as additional internal estrogen-sensitive controls. Rats on the soy-free diet had greater gains in body weight (259±6% baseline body weight) than rats on the soy-rich diet (238±4% baseline body weight). No differences were seen in uterine weight and histology, peri-ischemic physiological parameters, and infarct volumes between the treatment groups. Results of this pilot study suggest that the dietary soy level tested may not alter acute infarct volumes in ischemic female rat brain. More studies addressing the potential confounding effects of dietary soy in “estrogen-sensitive” stroke models are needed if investigators are to make informed choices regarding diets used in experimental stroke research. PMID:20147341

  2. 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.

  3. Effects of acute hypoxia at moderate altitude on stroke volume and cardiac output during exercise.

    PubMed

    Fukuda, Taira; Maegawa, Taketeru; Matsumoto, Akihiro; Komatsu, Yutaka; Nakajima, Toshiaki; Nagai, Ryozo; Kawahara, Takashi

    2010-05-01

    It has been unclear how acute hypoxia at moderate altitude affects stroke volume (SV), an index of cardiac function, during exercise. The present study was conducted to reveal whether acute normobaric hypoxia might alter SV during exercise.Nine healthy male subjects performed maximal exercise testing under normobaric normoxic, and normobaric hypoxic conditions (O(2): 14.4%) in a randomized order. A novel thoracic impedance method was used to continuously measure SV and cardiac output (CO) during exercise. Acute hypoxia decreased maximal work rate (hypoxia; 247 + or - 6 [SE] versus normoxia; 267 + or - 8 W, P < 0.005) and VO(2) max (hypoxia; 2761 + or - 99 versus normoxia; 3039 + or - 133 mL/min, P < 0.005). Under hypoxic conditions, SV and CO at maximal exercise decreased (SV: hypoxia; 145 + or - 11 versus normoxia; 163 + or - 11 mL, P < 0.05, CO: hypoxia; 26.7 + or - 2.1 versus normoxia; 30.2 + or - 1.8 L/min, P < 0.05). In acute hypoxia, SV during submaximal exercise at identical work rate decreased. Furthermore, in hypoxia, 4 of 9 subjects attained their highest SV at maximal exercise, while in normoxia, 8 of 9 subjects did.Acute normobaric hypoxia attenuated the increment of SV and CO during exercise, and SV reached a plateau earlier under hypoxia than in normoxia. Cardiac function during exercise at this level of acute normobaric hypoxia might be attenuated.

  4. A Comparative Study of Pituitary Volume Variations in MRI in Acute Onset of Psychiatric Conditions

    PubMed Central

    Joish, Upendra Kumar; Sahni, Hirdesh; George, Raju A; Sivasankar, Rajeev; Aggarwal, Rohit

    2017-01-01

    Introduction The growing belief that endocrine abnormalities may underlie many mental conditions has led to increased use of imaging and hormonal assays in patients attending to psychiatric OPDs. People who are in an acute phase of a psychiatric disorder show Hypothalamic Pituitary Adrenal (HPA) axis hyperactivity, but the precise underlying central mechanisms are unclear. Aim To assess the pituitary gland volume variations in patients presenting with new onset acute psychiatric illness in comparison with age and gender matched controls by using MRI. Materials and Methods The study included 50 patients, with symptoms of acute psychiatric illness presenting within one month of onset of illness and 50 age and gender matched healthy controls. Both patients and controls were made to undergo MRI of the Brain. A 0.9 mm slices of entire brain were obtained by 3 dimensional T1 weighted sequence. Pituitary gland was traced in all sagittal slices. Anterior pituitary and posterior pituitary bright spot were measured separately in each slice. Volume of the pituitary (in cubic centimetre- cm3) was calculated by summing areas. Significance of variations in pituitary gland volumes was compared between the cases and controls using Analysis of Covariance (ANOVA). Results There were significantly larger pituitary gland volumes in the cases than the controls, irrespective of psychiatric diagnosis (ANOVA, f=15.56; p=0.0002). Pituitary volumes in cases were 15.36% (0.73 cm3) higher than in controls. Conclusion There is a strong likelihood of HPA axis overactivity during initial phase of all mental disorders along with increased pituitary gland volumes. Further studies including hormonal assays and correlation with imaging are likely to provide further insight into neuroanatomical and pathological basis of psychiatric disorders. PMID:28384955

  5. Sex-linked differences in the course of chronic kidney disease and congestive heart failure: a study in 5/6 nephrectomized Ren-2 transgenic hypertensive rats with volume overload induced using aorto-caval fistula.

    PubMed

    Červenka, Luděk; Škaroupková, Petra; Kompanowska-Jezierska, Elzbieta; Sadowski, Janusz

    2016-10-01

    The role of hypertension and the renin-angiotensin system (RAS) in sex-related differences in the course of chronic kidney disease (CKD) and congestive heart failure (CHF) remain unclear, especially when the two diseases are combined. In male and female Ren-2 transgenic rats (TGR), a model of hypertension with activation of endogenous RAS, CKD was induced by 5/6 renal mass reduction (5/6 NX) and CHF was elicited by volume overload achieved by creation of an aorto-caval fistula (ACF). The primary aim of the study was to examine long-term CKD- and CHF-related mortality, especially in animals with CKD and CHF combined, with particular interest in the potential sex-related differences. The follow-up period was 23 weeks after the first intervention (5/6 NX). We found, first, that TGR did not exhibit sexual dimorphism in the course of 5/6 NX-induced CKD. Second, in contrast, TGR exhibited important sex-related differences in the course of ACF-induced CHF-related mortality: intact female TGR showed higher survival rate than male TGR. This situation is reversed in the course of combined 5/6 NX-induced CKD and ACF-induced CHF-related mortality: intact female TGR exhibited poorer survival than male TGR. Third, the survival rate in animals with combined 5/6 NX-induced CKD and ACF-induced CHF was significantly worsened as compared with rat groups that were exposed to 'single organ disease'. Collectively, our present results clearly show that CKD aggravates long-term mortality of animals with CHF. In addition, TGR exhibit remarkable sexual dimorphism with respect to CKD- and CHF-related mortality, especially in animals with combined CKD and CHF.

  6. Evaluation of mean platelet volume as a diagnostic biomarker in acute appendicitis

    PubMed Central

    Erdem, Hasan; Aktimur, Recep; Cetinkunar, Suleyman; Reyhan, Enver; Gokler, Cihan; Irkorucu, Oktay; Sozen, Selim

    2015-01-01

    Background: Diagnosis of acute appendicitis remains to be challenging with up to 30% negative exploration rates. In addition to careful clinical history and physical examination, we still need easily applicable, cheap and effective biomarker. Patients and methods: A retrospective case-controlled study was designed in two groups, both containing 100 patients, acute appendicitis and control. Leukocyte count, neutrophil percentage, platelet count and meal platelet volume (MPV) were compared. Results: MPV values for acute appendicitis and control groups were 7.4 ± 0.9 fL (5.6-10.6) and 9.1 ± 1.6 fL (5.1-13.1). For the diagnosis of acute appendicitis, ROC analysis revealed 74% sensitivity and 75% specificity for a cut-off value of 7.95 fL of MPV, however, the diagnostic value of leukocyte count and/or neutrophil ratio was superior. Conclusion: Our results suggest that, MPV value is an important parameter in the diagnosis of acute appendicitis, but in terms of sensitivity and specificity, leukocyte count and/or neutrophil percentage is superior. PMID:25785128

  7. Volume Exercise in Older Athletes Influences Inflammatory and Redox Responses to Acute Exercise.

    PubMed

    Estrela, Andre L; Zaparte, Aline; da Silva, Jefferson D; Moreira, José C; Turner, James E; Bauer, Moisés E

    2017-02-09

    To examine whether the volume of previous exercise training in older athletes influences inflammatory, redox and hormonal profiles, forty trained marathon runners were divided into higher-volume (HVG, ~480 min/week) and lower-volume groups (LVG, ~240 min/week). Plasma inflammatory proteins, redox biomarkers and salivary testosterone and cortisol, were assessed at rest and following two maximal acute exercise bouts. At rest, the LVG exhibited higher CRP, higher protein carbonyls and lower SOD activity compared to the HVG (p's<0.05). In response to exercise, TNF- declined similarly in both groups whereas CRP increased differentially (+60% LVG; +24% HVG; p's<0.05). Protein carbonyls decreased and thiols increased similarly in both groups, but SOD declined differentially between groups (-14% LVG; -20% HVG; p's<0.05). Salivary testosterone decreased similarly in both groups, whereas cortisol did not change. Higher-volume of training is associated with favorable inflammatory and redox profiles at rest, perhaps mediated by small inflammatory responses to acute exercise.

  8. 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.

  9. Dynamic functional cerebral blood volume responses to normobaric hyperoxia in acute ischemic stroke

    PubMed Central

    Wu, Ona; Lu, Jie; Mandeville, Joseph B; Murata, Yoshihiro; Egi, Yasu; Dai, Guangping; Marota, John J; Diwan, Izzuddin; Dijkhuizen, Rick M; Kwong, Kenneth K; Lo, Eng H; Singhal, Aneesh B

    2012-01-01

    Studies suggest that neuroprotective effects of normobaric oxygen (NBO) therapy in acute stroke are partly mediated by hemodynamic alterations. We investigated cerebral hemodynamic effects of repeated NBO exposures. Serial magnetic resonance imaging (MRI) was performed in Wistar rats subjected to focal ischemic stroke. Normobaric oxygen-induced functional cerebral blood volume (fCBV) responses were analyzed. All rats had diffusion-weighted MRI (DWI) lesions within larger perfusion deficits, with DWI lesion expansion after 3 hours. Functional cerebral blood volume responses to NBO were spatially and temporally heterogeneous. Contralateral healthy tissue responded consistently with vasoconstriction that increased with time. No significant responses were evident in the acute DWI lesion. In hypoperfused regions surrounding the acute DWI lesion, tissue that remained viable until the end of the experiment showed relative preservation of mean fCBV at early time points, with some rats showing increased fCBV (vasodilation); however, these regions later exhibited significantly decreased fCBV (vasoconstriction). Tissue that became DWI abnormal by study-end initially showed marginal fCBV changes that later became moderate fCBV reductions. Our results suggest that a reverse-steal hemodynamic effect may occur in peripheral ischemic zones during NBO treatment of focal stroke. In addition, CBV responses to NBO challenge may have potential as an imaging marker to distinguish ischemic core from salvageable tissues. PMID:22739619

  10. Vital capacities in acute and chronic airway obstruction: dependence on flow and volume histories.

    PubMed

    Brusasco, V; Pellegrino, R; Rodarte, J R

    1997-06-01

    The aim of this study was to investigate whether measurements of vital capacity (VC) are affected by the direction of the manoeuvre (inspiratory vs expiratory) and by the rate of expiratory flow. The study was performed on 25 individuals with chronic airway obstruction (CAO) and a forced expiratory volume in one second (FEV1) (expressed in standardized residuals (SR)) of -2.0+/-1.4 SD (CAO group), and 10 asthmatic subjects with methacholine (MCh)-induced bronchoconstriction (FEV1 -23+/-1.02 SR) (MCh group). VCs were measured during fast inspiration following both slow (FIVCse) and forced (FIVCfe) expiration from end-tidal inspiration to residual volume (RV), and during slow (EVC) or forced (FVC) expiration from total lung capacity (TLC). In the CAO group, FVC was the smallest volume (3.75+/-1.03 L) and significantly different from the other three estimates of VC; FIVCse (4.03+/-0.91 L) was the largest volume and significantly different from FVC and FIVCfe (3.83+/-0.98 L). In the MCh group, FVC (4.16+/-0.94 L) and EVC (4.19+/-0.89 L) were the largest volumes, although only the difference between FVC and FIVCfe (3.76+/-0.81 L) reached statistical significance. These data suggest that both flow and volume histories contribute to decreased vital capacities during bronchoconstriction. However, whereas increasing expiratory flow always tends to decrease vital capacity, the volume history of full inflation has different effects in chronic and acute bronchoconstriction, probably due to different effects on airway calibre. These results stress the importance of using standardized manoeuvres in order to obtain comparable values of vital capacity.

  11. Efficacy and safety of continuous hemodiafiltration for acute decompensated heart failure.

    PubMed

    Shiomi, Hiroki; Matsubara, Kinya; Ariyoshi, Makoto; Iwamura, Yumi; Fukui, Kensuke; Sakamoto, Tomoko; Sawanishi, Takayoshi; Shima, Masami; Furukawa, Keizo

    2010-07-01

    The mortality of heart failure patients with renal insufficiency is high, and these patients tend to develop diuretic resistance. Under these conditions, continuous hemodiafiltration (CHDF) is a possible alternative volume reduction therapy to diuretics. However, its efficacy and safety are not clear. Between April 2005 and March 2008, 248 patients with acute decompensated heart failure were admitted to the CCU of Kyoto City Hospital. Of those patients, 31 (20 volume overloaded heart failure, 11 cardiogenic shock) received CHDF therapy, and their weight loss, acute hemodynamic changes, and clinical outcome were assessed to evaluate the efficacy and safety of CHDF therapy. CHDF was performed for 6.5 +/- 6.5 days. There was no significant change in acute hemodynamics after CHDF initiation. In the volume overloaded heart failure (VH) group, significant weight loss was observed at 24 hours and 48 hours after CHDF initiation (P < 0.001). In-hospital mortality of the VH group and cardiogenic shock (CS) group were 10.0% and 54.5%, respectively. CHDF for acute decompensated heart failure (ADHF) is a safe, effective, and reliable volume reduction therapy for volume overloaded heart failure. Further investigation is required to assess the effectiveness of CHDF for cardiogenic shock.

  12. Endoscopic lung volume reduction effectively treats acute respiratory failure secondary to bullous emphysema.

    PubMed

    Sexton, Paul; Garrett, Jeffrey E; Rankin, Nigel; Anderson, Graeme

    2010-10-01

    Emphysema often affects the lungs in a heterogeneous fashion, and collapse or removal of severely hyperinflated portions of lung can improve overall lung function and symptoms. The role of lung volume reduction (LVR) surgery in selected patients is well established, but that of non-surgical LVR is still being defined. In particular, use of endobronchial LVR is still under development. This case report describes a 48-year-old non-smoker with severe bullous emphysema complicated by acute hypercapnic respiratory failure, who was successfully treated by endobronchial valve placement while intubated in an intensive care unit.

  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.

  14. 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

  15. Information overload in medical practice.

    PubMed

    Zeldes, Nathan; Baum, Neil

    2011-01-01

    Most practices are inundated with an excess of information. This information overload, or "infoglut," results in distractions and a loss of productivity. This article will discuss the concept of infoglut and what every practice can do to manage the tsunami of information that threatens to consume our practices.

  16. 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…

  17. The Impact of Hospital/Surgeon Volume on Acute Renal Failure and Mortality in Liver Transplantation: A Nationwide Cohort Study

    PubMed Central

    Cheng, Chih-Wen; Liu, Fu-Chao; Lin, Jr-Rung; Tsai, Yung-Fong; Chen, Hsiu-Pin; Yu, Huang-Ping

    2016-01-01

    The aim of this study was to assess whether the case volume of surgeons and hospitals affects the rates of postoperative complications and survival after liver transplantation. This population-based retrospective cohort study included 2938 recipients of liver transplantation performed between 1998 and 2012, enrolled from the Taiwan National Health Insurance Research Database. They were divided into two groups, according to the cumulative case volume of their operating surgeons and the case volume of their hospitals. The duration of intensive care unit stay and post-transplantation hospitalization, postoperative complications, and mortality were analyzed. The results showed that, in the low and high case volume surgeons groups, respectively, acute renal failure occurred at the rate of 14.11% and 5.86% (p<0.0001), and the overall mortality rates were 19.61% and 12.44% (p<0.0001). In the low and high case volume hospital groups, respectively, acute renal failure occurred in 11% and 7.11% of the recipients (p = 0.0004), and the overall mortality was 18.44% and 12.86% (p<0.0001). These findings suggest that liver transplantation recipients operated on higher case volume surgeons or in higher case volume hospitals have a lower rate of acute renal failure and mortality. PMID:27706183

  18. Brain volume and cognitive function in adult survivors of childhood acute lymphoblastic leukemia.

    PubMed

    Edelmann, Michelle N; Krull, Kevin R

    2013-10-01

    The survival rate for childhood acute lymphoblastic leukemia (ALL) is greater than 80%. However, many of these survivors develop long-term chronic health conditions, with a relatively common late effect being neurocognitive dysfunction. Although neurocognitive impairments have decreased in frequency and severity as treatment has evolved, there is a subset of survivors in the current treatment era that are especially vulnerable to the neurotoxic effects of ALL and its treatment. Additionally, little is known about long-term brain development as survivors mature into adulthood. A recent study by Zeller et al. compared neurocognitive function and brain volume in 130 adult survivors of childhood ALL to 130 healthy adults matched on age and sex. They identified the caudate as particularly sensitive to the neurotoxic effects of chemotherapy. We discuss the implications and limitations of this study, including how their findings support the concept of individual vulnerability to ALL and its treatment.

  19. Lung volume recruitment acutely increases respiratory system compliance in individuals with severe respiratory muscle weakness

    PubMed Central

    Molgat-Seon, Yannick; Hannan, Liam M.; Dominelli, Paolo B.; Peters, Carli M.; Fougere, Renee J.; McKim, Douglas A.; Sheel, A. William

    2017-01-01

    The aim of the present study was to determine whether lung volume recruitment (LVR) acutely increases respiratory system compliance (Crs) in individuals with severe respiratory muscle weakness (RMW). Individuals with RMW resulting from neuromuscular disease or quadriplegia (n=12) and healthy controls (n=12) underwent pulmonary function testing and the measurement of Crs at baseline, immediately after, 1 h after and 2 h after a single standardised session of LVR. The LVR session involved 10 consecutive supramaximal lung inflations with a manual resuscitation bag to the highest tolerable mouth pressure or a maximum of 50 cmH2O. Each LVR inflation was followed by brief breath-hold and a maximal expiration to residual volume. At baseline, individuals with RMW had lower Crs than controls (37±5 cmH2O versus 109±10 mL·cmH2O−1, p<0.001). Immediately after LVR, Crs increased by 39.5±9.8% to 50±7 mL·cmH2O−1 in individuals with RMW (p<0.05), while no significant change occurred in controls (p=0.23). At 1 h and 2 h post-treatment, there were no within-group differences in Crs compared to baseline (all p>0.05). LVR had no significant effect on measures of pulmonary function at any time point in either group (all p>0.05). During inflations, mean arterial pressure decreased significantly relative to baseline by 10.4±2.8 mmHg and 17.3±3.0 mmHg in individuals with RMW and controls, respectively (both p<0.05). LVR acutely increases Crs in individuals with RMW. However, the high airway pressures during inflations cause reductions in mean arterial pressure that should be considered when applying this technique. PMID:28326313

  20. [Genetics of hereditary iron overload].

    PubMed

    Le Gall, Jean-Yves; Jouanolle, Anne-Marie; Fergelot, Patricia; Mosser, Jean; David, Véronique

    2004-01-01

    The classification of hereditary abnormalities of iron metabolism was recently expanded and diversified. Genetic hemochromatosis now corresponds to six diseases, namely classical hemochromatosis HFE 1; juvenile hemochromatosis HFE 2 due to mutations in an unidentified gene on chromosome 1; hemochromatosis HFE 3 due to mutations in the transferrin receptor 2 (TfR2); hemochromatosis HFE 4 caused by a mutation in the H subunit of ferritin; and hemochromatosis HFE 6 whose gene is hepcidine (HAMP). Systemic iron overload is also associated with aceruloplasminemia, atransferrinemia and the "Gracile" syndrome caused by mutations in BCS1L. The genes responsible for neonatal and African forms of iron overload are unknown. Other genetic diseases are due to localized iron overload: Friedreich's ataxia results from the expansion of triple nucleotide repeats within the frataxin (FRDA) gene; two forms of X-linked sideroblastic anemia are due to mutations within the delta aminolevulinate synthetase (ALAS 2) or ABC-7 genes; Hallervorden-Spatz syndrome is caused by a pantothenate kinase 2 gene (PANK-2) defect; neuroferritinopathies; and hyperferritinemia--cataract syndrome due to a mutation within the L-ferritin gene. In addition to this wide range of genetic abnormalities, two other features characterize these iron disorders: 1) most are transmitted by an autosomal recessive mechanism, but some, including hemochromatosis type 4, have dominant transmission; and 2) most correspond to cytosolic iron accumulation while some, like Friedreich's ataxia, are disorders of mitochondrial metabolism.

  1. Correlation between bone marrow dose volumes and acute hematological toxicity in postoperative gynecological cancer patients

    PubMed Central

    Li, Qian; Jiang, Ming-Hua; Chen, Jing; Liu, Wei; Zhu, Bi-Qing; Lu, E-Mei

    2016-01-01

    Objective: To identify the association between radiation dose volume and acute hematological toxicity (HT) in postoperative gynecological cancer patients receiving whole pelvic radiotherapy (RT) or intensity-modulated RT (IMRT), a principal component regression model was used to calculate HT. Methods: Women (n=100) receiving with or without chemotherapy RT were retrospectively analyzed, 52 of whom received chemotherapy (paclitaxel and nedaplatin). The pelvis and lumbar vertebrae, defined as the prolong-pelvic bone marrow, were divided into the (1) combined ilium, ischium and pubis and the (2) lumbar vertebrae and the sacrum. The V5-V40 of subsides was calculated. The complete blood counts were recorded weekly. The principal component analysis was performed on volumes which generated the principal components (PCs), followed by using a logistic regression model. Results: Forty-seven patients presented with grade 2-3 HT during RT. Chemotherapy increased the incidence of HT compared with RT alone (70.21% vs. 29.79%; p=0.001). Fifty-three patients with persistent HT developed more serious HT at an earlier stage of RT. The chemotherapy cycles and three PCs associated with grade 2-3 HT was identified to form the resulting principal logistic regression model. Conclusion: A new method to calculate the NTCP was achieved by PCs logistic regression. PMID:28083062

  2. Differential modulation of right ventricular strain and right atrial mechanics in mild vs. severe pressure overload.

    PubMed

    Voeller, Rochus K; Aziz, Abdulhameed; Maniar, Hersh S; Ufere, Nneka N; Taggar, Ajay K; Bernabe, Noel J; Cupps, Brian P; Moon, Marc R

    2011-12-01

    Increased right atrial (RA) and ventricular (RV) chamber volumes are a late maladaptive response to chronic pulmonary hypertension. The purpose of the current investigation was to characterize the early compensatory changes that occur in the right heart during chronic RV pressure overload before the development of chamber dilation. Magnetic resonance imaging with radiofrequency tissue tagging was performed on dogs at baseline and after 10 wk of pulmonary artery banding to yield either mild RV pressure overload (36% rise in RV pressure; n = 5) or severe overload (250% rise in RV pressure; n = 4). The RV free wall was divided into three segments within a midventricular plane, and circumferential myocardial strain was calculated for each segment, the septum, and the left ventricle. Chamber volumes were calculated from stacked MRI images, and RA mechanics were characterized by calculating the RA reservoir, conduit, and pump contribution to RV filling. With mild RV overload, there were no changes in RV strain or RA function. With severe RV overload, RV circumferential strain diminished by 62% anterior (P = 0.04), 42% inferior (P = 0.03), and 50% in the septum (P = 0.02), with no change in the left ventricle (P = 0.12). RV filling became more dependent on RA conduit function, which increased from 30 ± 9 to 43 ± 13% (P = 0.01), than on RA reservoir function, which decreased from 47 ± 6 to 33 ± 4% (P = 0.04), with no change in RA pump function (P = 0.94). RA and RV volumes and RV ejection fraction were unchanged from baseline during either mild (P > 0.10) or severe RV pressure overload (P > 0.53). In response to severe RV pressure overload, RV myocardial strain is segmentally diminished and RV filling becomes more dependent on RA conduit rather than reservoir function. These compensatory mechanisms of the right heart occur early in chronic RV pressure overload before chamber dilation develops.

  3. Acute effects of different volumes of dynamic stretching on vertical jump performance, flexibility and muscular endurance.

    PubMed

    Ryan, Eric D; Everett, Kenneth L; Smith, Doug B; Pollner, Christie; Thompson, Brennan J; Sobolewski, Eric J; Fiddler, Ryan E

    2014-11-01

    The purpose of this study was to examine the acute effects of different volumes of a dynamic stretching routine on vertical jump (VJ) performance, flexibility and muscular endurance (ME). Twenty-six males (age 22.2 ± 1.3 years) performed three separate randomized conditions: (i) a control (CON) condition (5-min jog + 12 min of resting), (ii) a 5-min jog + a dynamic stretching routine (DS1; 6.7 ± 1.3 min) and (iii) a 5-min jog + a dynamic stretching routine with twice the volume (DS2; 12.1 ± 1.6 min). The dynamic stretching routine included 11 exercises targeting the hip and thigh musculature. VJ performance (jump height and velocity) and flexibility were measured prior to and following all conditions, while ME was measured following all conditions. The DS1 and DS2 conditions increased VJ height and velocity (P<0.01), while the CON condition did not change (P>0.05). When compared to the CON condition, the DS1 condition did not improve ME (P>0.05), whereas the DS2 condition resulted in a significant (15.6%) decrease in the number of repetitions completed (P<0.05). Flexibility increased following all conditions (P<0.01), while the DS1 condition was significantly greater (P<0.01) than the CON condition at post-testing. These results suggest that dynamic stretching routines lasting approximately 6-12 min performed following a 5-min jog resulted in similar increases in VJ performance and flexibility. However, longer durations of dynamic stretching routines may impair repetitive high-intensity activities.

  4. [Fluid overload and arterial hypertension in hemodialysis patients].

    PubMed

    Arkouche, Walid; Giaime, Philippe; Mercadal, Lucile

    2013-11-01

    The water sodium overload is a factor of morbi-mortality and its treatment is one of the markers of adequacy of the hemodialysis treatment. Its first clinical assessment was improved by tools such as echocardiography and ultrasonography of the inferior vena cava, the per-dialytic curve of plasma volume, measuring BNP or proBNP and by impedancemetry. The combination of the evaluation of these parameters and of the clinical situation allows one to assess the extracellular overload, the state of the blood volume and the potential of plasma refilling. The latter is a key factor of the per-dialytic hemodynamic tolerance. It is itself a determining factor in weight can be achieved at the end of the session. Getting the "dry" weight can require modifications of the prescriptions of the hemodialysis sessions, a filling by albumin even a drugs support. Finally, the overload treatment is the central part of the treatment of arterial hypertension, which has to benefit however often from antihypertensive treatment the profit of which is demonstrated.

  5. [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.

  6. 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.

  7. 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 ...

  8. Rectal planning risk volume correlation with acute and late toxicity in 3-dimensional conformal radiation therapy for prostate cancer.

    PubMed

    Dias, R S; Giordani, A J; Souhami, L; Segreto, R A; Segreto, H R C

    2011-12-01

    The purpose of this study was to evaluate rectum motion during 3-Dimensional conformal radiation therapy (3D-CRT) in prostate cancer patients, to derive a planning volume at risk (PRV) and to correlate the PRV dose-volume histograms (DVH) with treatment complications.This study was conducted in two phases. Initially, the PRV was defined prospectively in 50 consecutive prostate cancer patients (Group 1) who received a radical course of 3-D CRT. Then, the obtained PRV was used in the radiotherapy planning of these same 50 patients plus another 59 prostate cancer patients (Group 2) previously treated between 2004 and 2008. All these patients' data, including the rectum and PRV DVHs, were correlated to acute and late complications, according to the Common Toxicity Criteria (CTC) v4.0.The largest displacement occurred in the anterior axis. Long-term gastrointestinal (GI) complications grade ≥ 2 were seen in 9.2% of the cases. Factors that influenced acute GI reactions were: doses at 25% (p 5 0.011) and 40% (p 5 0.005) of the rectum volume and at 40% of the PRV (p 5 0.012). The dose at 25% of the rectum volume (p 5 0.033) and acute complications ≥ grade 2 (p 5 0.018) were prognostic factors for long-term complications. The PRV DVH did not correlate with late toxicity. The rectum showed a significant inter-fraction motion during 3D-CRT for prostate cancer. PRV dose correlated with acute gastrointestinal complications and may be a useful tool to predict and reduce their occurrence.

  9. Mean Platelet Volume and Platelet Distribution Width as Markers in the Diagnosis of Acute Gangrenous Appendicitis

    PubMed Central

    Fan, Zhe; Pan, Jiyong; Zhang, Yingyi; Wang, Ziyi; Zhu, Ming; Yang, Baoshun; Shi, Lei; Jing, Huirong

    2015-01-01

    Introduction. Acute gangrenous appendicitis (AGA) is a common medical condition; however, the grade of appendicitis usually cannot be established preoperatively. We have attempted to identify some indicators, such as the mean platelet volume (MPV) and the platelet distribution width (PDW), to diagnose AGA. Aims. To evaluate whether or not the MPV and PDW are suitable markers to diagnose AGA. Methods. A retrospective study of 160 patients with AGA and 160 healthy patients was undertaken. Disease diagnosis was confirmed based on the pathologic examination of surgical specimens. Patient white blood cell (WBC) count, neutrophil ratio (NR), platelet (PLT) count, MPV, PDW, and hematocrit (HCT) were analyzed. Receiver operating characteristic (ROC) curves were used to evaluate the sensitivity and specificity of these indices in AGA. Results. There were no significant differences between the AGA and control groups in age and gender. Compared to the control group, the WBC count, NR, and PDW were significantly higher (P < 0.001, resp.) and the MPV and HCT were significantly lower (P < 0.001, resp.) in the AGA group. The diagnostic specificities of the WBC count, NR, PLT count, MPV, PDW, and HCT were 86.3%, 92.5%, 58.1%, 81.7%, 83.9%, and 66.3%, respectively. Therefore, the NR had the highest diagnostic specificity for the diagnosis of AGA. Conclusions. This is the first study to assess the MPV and PDW in patients with AGA. Our present study showed that the MPV is reduced and the PDW is increased in patients with AGA; the sensitivity of PDW was superior to the MPV. A decreased MPV value and an increased PDW could serve as two markers to diagnose AGA. The NR had the highest specificity for the diagnosis of AGA. PMID:26688600

  10. JAK2 mediates the acute response to decreased cell volume in mouse preimplantation embryos by activating NHE1.

    PubMed

    Zhou, Chenxi; Baltz, Jay M

    2013-02-01

    Preimplantation mouse embryos are particularly sensitive to increased osmolarity within their normal physiological range. The detrimental effects can be alleviated by organic osmolytes such as glycine transported into early embryos, an effect thought to be due to the organic osmolyte replacing a portion of intracellular inorganic ions accumulated during acute cell volume regulation. However, no mechanism of cell volume regulation dependent on inorganic ions has been identified in preimplantation embryos. We found that decreased cell volume rapidly activated Na(+)/H(+) exchange in preimplantation mouse embryos. This activity was likely mediated by the NHE1 (Slc9a1) isoform, since it was blocked by the highly selective NHE1 inhibitor, cariporide, which also inhibited the ability of the 1-cell embryo to maintain cell volume. How NHE1 is activated by decreased cell volume is not generally well understood. Full activation of NHE1 by decreased cell volume in 2-cell mouse embryos required the activity of the tyrosine kinase Janus kinase 2 (Jak2), since NHE1 activation was inhibited by the general tyrosine kinase inhibitor genistein, several selective inhibitors of Jak2, and dominant negative Jak2 expressed in 2-cell embryos. Decreased cell volume furthermore resulted in increased tyrosine phosphorylation of proteins in 2-cell embryos detected both by anti-phosphotyrosine antibody and an antibody directed against active phospho-Jak2. Thus, Jak2 apparently serves as a cell volume sensor in embryos. Evidence from pharmacological inhibitors further indicated that NHE1 activation by decreased cell volume was dependent on calmodulin activity, likely downstream of Jak2, and required active phospholipase C.

  11. [Genetic iron overloads and hepatic insulin-resistance iron overload syndrome: an update].

    PubMed

    Ruivard, M

    2009-01-01

    Hepcidin inhibits intestinal absorption of iron through internalisation of ferroportin. Its discovery helps to better understand the genetic iron overloads. The insulin resistance-hepatic iron overload (IR-HIO)--also coined as the dysmetabolic iron overload syndrome--is a common cause or iron overload. This article is a review about genetic iron overloads and IR-HIO. Type 1 haemochromatosis C282Y +/+ accounts for 95% of the haemochromatosis. Hepatic fibrosis may develop if serum ferritin is higher than 1000 microg/l but can be partially reversible with phlebotomies. Juvenile haemochromatosis (type 2) and type 3 haemochromatosis (mutation of the transferrin receptor 2) are very uncommon. Several mutations of the ferroportin gene can cause usually mild iron overload of autosomal dominant inheritance. Aceruleoplasminemia is an uncommon disorder involving cerebral iron overload. The causes and consequences of the IR-HIO are unknown. Treatment of IR-HIO is focused on metabolic syndrome and phlebotomies are questionable because the overload is moderate and intestinal absorption of iron seems to be low. MRI (or other non invasive methods) is needed to truly assess iron overload because serum ferritin overestimates it in metabolic syndrome. Several points have to be elucidated: how HFE interferes with hepcidin in type 1 haemochromatosis; the causes of variability of iron overload; the benefits of populations screening; the advantage of phlebotomies in IR-HIO; the use of new oral iron chelators.

  12. Increase in volume of lignocaine/adrenaline-containing local anaesthetic solution causes increase in acute postoperative pain after gingivectomy.

    PubMed

    Jorkjend, L; Skoglund, L A

    2000-06-01

    A randomized, single-blind, within-patient, crossover study was done in 44 patients (27 women and 17 men mean age 47 years, range 29-63) who had bilateral 'identical' gingivectomies. On one occasion a standard volume of local anaesthetic containing lignocaine 2% and adrenaline (1/80 000) was infiltrated into the mucosal tissue before operation. On the other occasion double the standard volume was infiltrated. The intensity of pain postoperatively was recorded by the patients on 100 mm visual analogue scale every hour for an 11-hour observation period. The intensity of pain when double volume had been given was significantly higher than that after the standard volume from 2 to 8 hours postoperatively (P < 0.04), the median (range) being 52.0 mm (0.0-434.0) compared with 30.5 mm (0.0-359.0) after the standard volume (P < 0.005). Doubling the volume of local anaesthetic containing adrenaline that was infiltrated increased the intensity of acute pain after gingivectomy.

  13. Transfusion related acute lung injury presenting with acute dyspnoea: a case report

    PubMed Central

    Haji, Altaf Gauhar; Sharma, Shekhar; Vijaykumar, DK; Paul, Jerry

    2008-01-01

    Introduction Transfusion-related acute lung injury is emerging as a common cause of transfusion-related adverse events. However, awareness about this entity in the medical fraternity is low and it, consequently, remains a very under-reported and often an under-diagnosed complication of transfusion therapy. Case presentation We report a case of a 46-year old woman who developed acute respiratory and hemodynamic instability following a single unit blood transfusion in the postoperative period. Investigation results were non-specific and a diagnosis of transfusion-related acute lung injury was made after excluding other possible causes of acute lung injury. She responded to symptomatic management with ventilatory and vasopressor support and recovered completely over the next 72 hours. Conclusion The diagnosis of transfusion-related acute lung injury relies on excluding other causes of acute pulmonary edema following transfusion, such as sepsis, volume overload, and cardiogenic pulmonary edema. All plasma containing blood products have been implicated in transfusion-related acute lung injury, with the majority being linked to whole blood, packed red blood cells, platelets, and fresh-frozen plasma. The pathogenesis of transfusion-related acute lung injury may be explained by a "two-hit" hypothesis, involving priming of the inflammatory machinery and then activation of this primed mechanism. Treatment is supportive, with prognosis being substantially better than for most other causes of acute lung injury. PMID:18957111

  14. 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.

  15. 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.

  16. Cardiorenal-endocrine dynamics during and following volume expansion

    SciTech Connect

    Zimmerman, R.S.; Edwards, B.S.; Schwab, T.R.; Heublein, D.M.; Burnett, J.C. Jr.

    1987-02-01

    The relationship between atrial pressure, atrial natriuretic peptide (ANP), the renin-angiotensin-aldosterone system, and renal hemodynamic and excretory function was examined during and following acute 10% body weight saline volume expansion and measurements were made at 3.3, 6.6, and 10% body weight volume expansion in pentobarbital anesthetized dogs. Right atrial pressure (RAP), pulmonary capillary wedge pressure (PCWP), fractional excretion of Na (FE/sub Na/), and ANP all increased in parallel during volume expansion. Plasma renin activity (PRA) and aldosterone decreased in parallel during 10% volume expansion. ANP, PRA and aldosterone were measured by radioimmunoassay. Following 10% volume expansion, saline was infused at the peak urine flow rate to maintain peak volume expansion. Despite continued saline infusion, RAP, PCWP, and ANP decreased in parallel. In contrast, FE/sub Na/ remained increased, and aldosterone and PRA remained depressed. These studies demonstrate that atrial pressures, ANP, and FE/sub Na/ increase in parallel during volume expansion; this suggests a role for ANP in modulating acute atrial volume overload. During stable volume expansion periods, however, despite a decrease in ANP levels, Na excretion remains elevated, suggesting that non-ANP mechanisms may be important in maintaining natriuresis during stable volume expansion.

  17. 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)

  18. 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...

  19. 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

  20. 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

  1. 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

  2. Triphasic multinutrient supplementation during acute resistance exercise improves session volume load and reduces muscle damage in strength-trained athletes.

    PubMed

    Bird, Stephen P; Mabon, Tom; Pryde, Mitchell; Feebrey, Sarah; Cannon, Jack

    2013-05-01

    We hypothesized that triphasic multinutrient supplementation during acute resistance exercise would enhance muscular performance, produce a more favorable anabolic profile, and reduce biochemical markers of muscle damage in strength-trained athletes. Fifteen male strength-trained athletes completed two acute lower-body resistance exercise sessions to fatigue 7 days apart. After a 4-hour fast, participants consumed either a multinutrient supplement (Musashi 1-2-3 Step System, Notting Hill, Australia) (SUPP) or placebo (PLA) beverage preexercise (PRE), during (DUR), and immediately postexercise (IP). Session volume loads were calculated as kilograms × repetitions. Lower-body peak power was measured using unloaded repeated countermovement jumps, and blood samples were collected to assess biochemistry, serum hormones, and muscle damage markers at PRE, DUR, IP, 30 minutes postexercise (P30), and 24 hours postexercise (P24h). The SUPP demonstrated increased glucose concentrations at DUR and IP compared with at PRE (P < .01), whereas PLA demonstrated higher glucose at P30 compared with at PRE (P < .001). Session volume load was higher for SUPP compared with PLA (P < .05). Cortisol increased at DUR, IP, and P30 compared with at PRE in both treatments (P < .05); however, SUPP also displayed lower cortisol at P24h compared with at PRE and PLA (P < .01). The total testosterone response to exercise was higher for PLA compared with SUPP (P < .01); however, total creatine kinase and C-reactive protein responses to exercise were lower for SUPP compared with PLA (P < .05). These data indicate that although triphasic multinutrient supplementation did not produce a more favorable anabolic profile, it improved acute resistance exercise performance while attenuating muscle damage in strength-trained athletes.

  3. Solving the problem of overloading for the CMSL programming languages

    SciTech Connect

    Khalil, M.A.M.

    1989-01-01

    One of the most important, not yet achieved, goals in the computer science field is to design a language that approximates natural languages. In any natural language the same word can have more than one meaning. The distinction between the different meanings of a word comes from its context of use in different sentences. This is the problem in the widest view, but some of the prominent computer programming languages have adopted the concept of overloading, each in different way. Ada allows operator, enumeration, and subprogram name overloading but it does not allow variable name overloading within the same scope. Modula and Pascal allow a restricted form of overloading on literals and operators but then do not allow overloading for subprogram and variable names. Modcap allows operator and variable name overloading, but it does not allow subprogram name overloading. C allows a restricted form of overloading on operators, but it does not allow subprogram, variable, and literal name overloading. Fortran allows a restricted form of overloading on operators, but it does not allow subprogram, variable, and literal name overloading. Smalltalk allows subprogram (method) name overloading as far as they belong to different classes, but it does not allow literal or variable name overloading. CMSL (Contour Model Source Language) is a new language which has some novel semantic properties. The author develops an algorithm which solves the problem of overloading in the CMSL language, and which could be exploited by other languages.

  4. [The use of gravitation overloading in the treatment of obliterative atherosclerosis of lower extremity arteries].

    PubMed

    Galkin, R A; Kotel'nikov, G P; Makarov, I V; Oparin, A N

    2003-01-01

    The article sums up results of treatment of 152 patients with obliterating atherosclerosis of the lower extremity arteries which were exposed to 2-3 G gravitation overloading made in a centrifuge of a short radius in direction head--pelvis. The gravitation overloading in the regimen followed were not found to have negative effects of central hemodynamics. Peripheral circulation was noted to considerably improve which is confirmed: 1) by clinical data showing 2-5 times longer distance of painless walking; 2) by the data of ultrasound dopplerography manifested as larger volume rate of blood flow and regional perfusion index; 3) by thermographic explorations evidencing the recovery of the thermoprophile of the legs and feet. Thus, the application of gravitation overloading is a new effective method of conservative treatment of patients with the pathology in question.

  5. The Accuracy of Natriuretic Peptides (BNP and NT-pro-BNP) in the Differentiation between Transfusion Related Acute Lung Injury (TRALI) and Transfusion Related Circulatory Overload (TACO) in the Critically Ill

    PubMed Central

    Li, Guangxi; Daniels, Craig E.; Kojicic, Marija; Krpata, Tami; Wilson, Greg A; Winters, Jeffrey L; Moore, S Breanndan; Gajic, Ognjen

    2009-01-01

    BACKGROUND The diagnostic workup of TRALI requires an exclusion of TACO. Brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic (NT-pro-BNP) accurately diagnosed TACO in preliminary studies that did not include patients with TRALI. STUDY DESIGN AND METHODS In this prospective cohort study two critical care experts blinded to serum levels of BNP and NT-pro-BNP determined the diagnosis of TRALI, TACO, and possible TRALI based on the consensus conference definitions. The accuracy of BNP and NT-pro-BNP was assessed based on the area under the receiver operating curve (AUC). RESULTS Of 115 patients who developed acute pulmonary edema after transfusion, 34 were identified with TRALI, 31 with possible TRALI, and 50 with TACO. Median BNP was 375pg/mL (interquartile range [IQR], 122.5 to 780.5pg/mL) in TRALI, 446pg/mL (IQR, 128 to 743.3pg/mL) in possible TRALI and 559pg/mL (IQR, 287.8 to 1347.8pg/mL) in TACO patients (p=0.038). The NT-pro-BNP levels among patients with TRALI, possible TRALI and TACO differed significantly with a median value of 1558.5pg/mL(IQR, 628.5 to 5114pg/mL), 2349pg/mL(IQR, 919 to 4610pg/mL) and 5197pg/mL(IQR, 1695 to 15714pg/mL)(p=0.0036), respectively. The accuracy of BNP and NT-pro-BNP to diagnose TACO was moderate with an area under curve (AUC) of 0.63(95% confidence interval [CI] 0.51 to 0.74) and 0.70(95%CI 0.59 to 0.80). CONCLUSIONS Natriuretic peptides are of limited diagnostic value in a differential diagnosis of pulmonary edema after transfusion in the critically ill patients. PMID:18954397

  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 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.

  8. Acute severe organophosphate poisoning in a child who was successfully treated with therapeutic plasma exchange, high-volume hemodiafiltration, and lipid infusion.

    PubMed

    Yesilbas, Osman; Kihtir, Hasan S; Altiti, Mohammad; Petmezci, Mey Talip; Balkaya, Seda; Bursal Duramaz, Burcu; Ersoy, Melike; Sevketoglu, Esra

    2016-10-01

    Acute severe organophosphate poisoning is a serious complication seen in developing and agricultural countries. Pralidoxime and high dose atropine are the standard treatments. There is no consensus about acute severe organophosphate poisonings that are unresponsive to pralidoxime, atropine, and supportive therapies. We report a case of acute severe organophosphate poisoning that was unresponsive to standard treatments and successfully treated with high-volume continuous venovenous hemodiafiltration and therapeutic plasma exchange combined with lipid infusion. J. Clin. Apheresis 31:467-469, 2016. © 2015 Wiley Periodicals, Inc.

  9. Reduced defense of central blood volume during acute lower body negative pressure-induced hypovolemic circulatory stress in aging women.

    PubMed

    Lindenberger, Marcus; Länne, Toste

    2012-06-01

    Elderly humans are more vulnerable to trauma and hemorrhage than young and elderly men and respond with decreased defense of central blood volume during acute experimental hypovolemia induced by lower body negative pressure (LBNP). However, these defense mechanisms have not been evaluated in elderly women. The aim of this study was to determine the effectiveness of compensatory responses to defend central blood volume during experimental hypovolemia in elderly and young women. Cardiovascular responses in 34 women, 12 elderly (66 ± 1 years) and 22 young women (23 ± 0.4 years), were studied during experimental hypovolemia induced by LBNP of 11 to 44 mmHg. Air plethysmography was used to assess the capacitance response (redistribution of peripheral venous blood to the central circulation) as well as net capillary fluid transfer from tissue to blood in the arm. Lower body negative pressure seemed to create comparable hypovolemia measured as total calf volume increase in elderly and young women. Heart rate increased less in elderly women (LBNP of 44 mmHg: 20 ± 2 vs. 37 ± 4%; P < 0.01) but with similar (%) increase in forearm vascular resistance. Mobilization of capacitance blood from the peripheral circulation was both slower and decreased by ∼60% in elderly women (P < 0.001), and net capillary fluid absorption from surrounding tissues was reduced by ∼40% (P < 0.01, LBNP of 44 mmHg). Elderly women responded with less increase in heart rate but with equal forearm vascular resistance (%) response during LBNP. Furthermore, the compensatory capacitance response was both slower and substantially decreased, and net capillary fluid absorption considerably reduced, collectively indicating less efficiency to defend central blood volume in elderly than in young women.

  10. Pressure-volume curves in acute respiratory failure: automated low flow inflation versus occlusion.

    PubMed

    Servillo, G; Svantesson, C; Beydon, L; Roupie, E; Brochard, L; Lemaire, F; Jonson, B

    1997-05-01

    Pressure-volume (P-V) curves of the respiratory system allow determination of compliance and lower and upper inflection points (LIP and UIP, respectively). To minimize lung trauma in mechanical ventilation the tidal volume should be limited to the P-V range between LIP and UIP. An automated low flow inflation (ALFI) technique, using a computer-controlled Servo Ventilator 900C, was compared with a more conventional technique using a series of about 20 different inflated volumes (Pst-V curve). The pressure in the distal lung (Pdist) was calculated by subtraction of resistive pressure drop in connecting tubes and airways. Compliance (Cdist), Pdist(LIP), and Pdist(UIP) were derived from the Pdist-V curve and compared with Cst, Pst(LIP), and Pst(UIP) derived from the Pst-V curve. Nineteen sedated, paralyzed patients (10 with ARDS and 9 with ARF) were studied. We found: Cdist = 2.3 + 0.98 x Cst ml/cm H2O (r = 0.98); Pdist(LIP) = 0.013 + 1.09 x Pst(LIP) cm H2O (r = 0.96). In patients with ARDS: Pdist(UIP) = 4.71 + 0.84 x Pst(UIP) cm H2O (r = 0.94). In ARF, we found differences in UIP between the methods, but discrepancies occurred above tidal volumes and had little practical importance. They may reflect that Pdist comprises dynamic phenomena contributing to pressure in the distal lung at large volumes. Compliance, but not LIP and UIP, could be accurately determined without subtraction of resistive pressure from the pressure measured in the ventilator. We conclude that ALFI, which is fully automated and needing no ventilator disconnection, gives useful clinical information.

  11. [Bruxism and overload of periodontium and implants].

    PubMed

    Jacobs, R; De Laat, A

    2000-07-01

    Bruxism is responsible for occlusal tooth wear but can not induce nor aggravate gingivitis or periodontitis. Bruxism induces jiggling forces, which cause a clinical tooth hypermobility, radiologically seen as a widened periodontal space. Although there is no direct causal relation between bruxism and implant failure, implant overload may lead to fractures of the components and bone loss.

  12. Shock absorber protects motive components against overloads

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Shock absorber with an output shaft, hollow gear, and a pair of springs forming a resilient driving connection between shaft and gear, operates when abnormally high torques are applied. This simple durable frictional device is valuable in rotating mechanisms subject to sudden overloads.

  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. 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.

  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. 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....

  17. ACUTE EFFECTS OF DIFFERENT SELF‐MASSAGE VOLUMES ON THE FMS™ OVERHEAD DEEP SQUAT PERFORMANCE

    PubMed Central

    Škarabot, Jakob; Vigotsky, Andrew D; Brown, Amanda Fernandes; Gomes, Thiago Matassoli; Novaes, Jefferson da Silva

    2017-01-01

    Background The Functional Movement Screen (FMS™) is a battery of tests designed to assess movement competency; the overhead deep squat test, specifically, has been shown to be an accurate predictor of overall FMS™ scores. Self‐massage (SM) is a ubiquitous warm‐up utilized to increase joint range of motion and, therefore, may be effective for improving performance of the overhead deep squat test. Purpose To examine how different doses (30, 60, 90, and 120 seconds) of SM of different areas of the body (plantar fascia, latissimus dorsi, and lateral thigh) affects the score obtained on an overhead deep squat test. Methods Twenty recreationally active females were recruited to be tested on four occasions: sessions one and two consisted of baseline testing, session three consisted of SM applied to the lateral thigh, and session four consisted of SM applied to the lateral torso and plantar fascia. Results In all SM conditions, at least 90 seconds was required for a change in deep squat score from baseline; therefore, it is concluded that SM the lateral torso, plantar fascia, and lateral thigh for 90 seconds or more are effective interventions for acutely improving overhead deep squat scores. Conclusion Self‐massage appears to be an effective modality for inducing acute improvements in the performance of the FMS™ overhead deep squat in all conditions tested. Level of evidence 2b PMID:28217420

  18. Involvement of catecholaminergic medullary pathways in cardiovascular responses to acute changes in circulating volume.

    PubMed

    Cravo, S L; Lopes, O U; Pedrino, G R

    2011-09-01

    Water deprivation and hypernatremia are major challenges for water and sodium homeostasis. Cellular integrity requires maintenance of water and sodium concentration within narrow limits. This regulation is obtained through engagement of multiple mechanisms and neural pathways that regulate the volume and composition of the extracellular fluid. The purpose of this short review is to summarize the literature on central neural mechanisms underlying cardiovascular, hormonal and autonomic responses to circulating volume changes, and some of the findings obtained in the last 12 years by our laboratory. We review data on neural pathways that start with afferents in the carotid body that project to medullary relays in the nucleus tractus solitarii and caudal ventrolateral medulla, which in turn project to the median preoptic nucleus in the forebrain. We also review data suggesting that noradrenergic A1 cells in the caudal ventrolateral medulla represent an essential link in neural pathways controlling extracellular fluid volume and renal sodium excretion. Finally, recent data from our laboratory suggest that these structures may also be involved in the beneficial effects of intravenous infusion of hypertonic saline on recovery from hemorrhagic shock.

  19. 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.

  20. USE OF FRACTIONAL DOSE-VOLUME HISTOGRAMS TO MODEL RISK OF ACUTE RECTAL TOXICITY AMONG PATIENTS TREATED ON RTOG 94-06

    PubMed Central

    Tucker, Susan L.; Michalski, Jeff M.; Bosch, Walter R.; Mohan, Radhe; Dong, Lei; Winter, Kathryn; Purdy, James A.; Cox, James D.

    2012-01-01

    Background and Purpose For toxicities occurring during the course of radiotherapy, it is conceptually inaccurate to perform normal-tissue complication probability analyses using the complete dose-volume histogram. The goal of this study was to analyze acute rectal toxicity using a novel approach in which the fit of the Lyman-Kutcher-Burman (LKB) model is based on the fractional rectal dose-volume histogram (DVH). Materials and Methods Grade ≥2 acute rectal toxicity was analyzed in 509 patients treated on Radiation Therapy Oncology Group (RTOG) protocol 94-06. These patients had no field reductions or treatment-plan revisions during therapy, allowing the fractional rectal DVH to be estimated from the complete rectal DVH based on the total number of dose fractions delivered. Results The majority of patients experiencing Grade ≥2 acute rectal toxicity did so before completion of radiotherapy (70/80=88%). Acute rectal toxicity depends on fractional mean rectal dose, with no significant improvement in the LKB model fit when the volume parameter differs from n=1. The incidence of toxicity was significantly lower for patients who received hormone therapy (P=0.024). Conclusions Variations in fractional mean dose explain the differences in incidence of acute rectal toxicity, with no detectable effect seen here for differences in numbers of dose fractions delivered. PMID:22673726

  1. Complete blood count using VCS (volume, conductivity, light scatter) technology is affected by hyperlipidemia in a child with acute leukemia.

    PubMed

    Gokcebay, D G; Azik, F M; Isik, P; Bozkaya, I O; Kara, A; Tavil, E B; Yarali, N; Tunc, B

    2011-12-01

    Asparaginase, an effective drug in the treatment of childhood acute lymphoblastic leukemia (ALL), has become an important component of most childhood ALL regimens during the remission induction or intensification phases of treatment. The incidence range of asparaginase-associated lipid abnormalities that are seen in children is 67-72%. Lipemia causes erroneous results, which uses photometric methods to analyze blood samples. We describe a case of l-asparaginase-associated severe hyperlipidemia with complete blood count abnormalities. Complete blood count analysis was performed with Beckman COULTER(®) GEN·S™ system, which uses the Coulter Volume, Conductivity, Scatter technology to probe hydrodynamically focused cells. Although an expected significant inaccuracy in hemoglobin determination occurred starting from a lipid value of 3450 mg/dl, we observed that triglyceride level was 1466 mg/dl. Complete blood count analysis revealed that exceptionally high hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration levels vs. discordant with red blood cell count, mean corpuscular volume, and hematocrit levels. Total leukocyte count altered spontaneously in a wide range, and was checked with blood smear. Platelet count was in expected range (Table 1). Thus, we thought it was a laboratory error, and the patient's follow-up especially for red cell parameters was made by red blood cell and hematocrit values.

  2. Modulation of Pseudomonas aeruginosa lipopolysaccharide-induced lung inflammation by chronic iron overload in rat.

    PubMed

    Lê, Bá Vuong; Khorsi-Cauet, Hafida; Bach, Véronique; Gay-Quéheillard, Jérôme

    2012-03-01

    Iron constitutes a critical nutrient source for bacterial growth, so iron overload is a risk factor for bacterial infections. This study aimed at investigating the role of iron overload in modulating bacterial endotoxin-induced lung inflammation. Weaning male Wistar rats were intraperitoneally injected with saline or iron sucrose [15 mg kg(-1) body weight (bw), 3 times per week, 4 weeks]. They were then intratracheally injected with Pseudomonas aeruginosa lipopolysaccharide (LPS) (5 μg kg(-1) bw) or saline. Inflammatory indices were evaluated 4 or 18 h post-LPS/saline injection. At 4 h, LPS-treated groups revealed significant increases in the majority of inflammatory parameters (LPS-binding protein (LBP), immune cell recruitment, inflammatory cytokine synthesis, myeloperoxidase activity, and alteration of alveolar-capillary permeability), as compared with control groups. At 18 h, these parameters reduced strongly with the exception for LBP content and interleukin (IL)-10. In parallel, iron acted as a modulator of immune cell recruitment; LBP, tumor necrosis factor-α, cytokine-induced neutrophil chemoattractant 3, and IL-10 synthesis; and alveolar-capillary permeability. Therefore, P. aeruginosa LPS may only act as an acute lung inflammatory molecule, and iron overload may modulate lung inflammation by enhancing different inflammatory parameters. Thus, therapy for iron overload may be a novel and efficacious approach for the prevention and treatment of bacterial lung inflammations.

  3. Lung recruitment maneuver during volume guarantee ventilation of preterm infants with acute respiratory distress syndrome.

    PubMed

    Castoldi, Francesca; Daniele, Irene; Fontana, Paola; Cavigioli, Francesco; Lupo, Enrica; Lista, Gianluca

    2011-08-01

    Preterm infants need the achievement of adequate lung volume. Lung recruitment maneuver (LRM) is applied during high-frequency oscillatory ventilation. We investigated the effect of an LRM with positive end-expiratory pressure (PEEP) on oxygenation and outcomes in infants conventionally ventilated for respiratory distress syndrome (RDS). Preterm infants in assisted controlled ventilation+volume guarantee for RDS after surfactant randomly received an LRM (group A) or did not (group B). LRM entailed increments of 0.2 cm H (2)O PEEP every 5 minutes, until fraction of inspired oxygen (Fi O(2))=0.25. Then PEEP was reduced and the lung volume was set on the deflation limb of the pressure/volume curve. When saturation of peripheral oxygen fell and Fi O(2) rose, we reincremented PEEP until Sp O(2) became stable. Group A ( N=10) and group B ( N=10) infants were similar: gestational age 25 ± 2 versus 25 ± 2 weeks; body weight 747 ± 233 versus 737 ± 219 g; clinical risk index for babies 9.8 versus 8.1; initial Fi O(2) 56 ± 24 versus 52 ± 21, respectively. LRM began at 86 ± 69 minutes of age and lasted for 61 ± 18 minutes. Groups A and B showed different max PEEP during the first 12 hours of life (6.1 ± 0.3 versus 5.3 ± 0.3 cm H (2)O, P=0.00), time to lowest Fi O(2) (94 ± 24 versus 435 ± 221 minutes; P=0.000) and O(2) dependency (29 ± 12 versus 45 ± 17 days; P=0.04). No adverse events and no differences in the outcomes were observed. LRM led to the earlier lowest Fi O(2) of the first 12 hours of life and a shorter O (2) dependency.

  4. 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.

  5. Glucose Transporter 4 (GLUT4) is Not Necessary for Overload-Induced Glucose Uptake or Hypertrophic Growth in Mouse Skeletal Muscle.

    PubMed

    McMillin, Shawna L; Schmidt, Denise L; Kahn, Barbara B; Witczak, Carol A

    2017-03-09

    Glucose transporter 4 (GLUT4) is necessary for acute insulin- and contraction-induced skeletal muscle glucose uptake, but its role in chronic muscle loading (overload)-induced glucose uptake is unknown. Our goal was to determine if GLUT4 is required for overload-induced glucose uptake. Overload was induced in mouse plantaris muscle by unilateral synergist ablation. After 5 days, muscle weights and ex vivo [(3)H]-2-deoxy-D-glucose uptake were assessed. Overload-induced muscle glucose uptake and hypertrophic growth were not impaired in muscle-specific GLUT4 knockout mice, demonstrating that GLUT4 is not necessary for these processes. To assess which transporter(s) mediate overload-induced glucose uptake, chemical inhibitors were utilized. The facilitative GLUT inhibitor, cytochalasin B, but not the sodium-dependent glucose-co-transport inhibitor, phloridzin, prevented overload-induced uptake demonstrating that GLUT(s) mediate this effect. To assess which GLUT, hexose competition experiments were performed. Overload-induced [(3)H]-2-deoxy-D-glucose uptake was not inhibited by D-fructose, demonstrating that the fructose-transporting GLUT2, GLUT5, GLUT8, and GLUT12, do not mediate this effect. To assess additional GLUTs, immunoblots were performed. Overload increased GLUT1, GLUT3, GLUT6 and GLUT10 protein levels 2- to 5-fold. Collectively, these results demonstrate that GLUT4 is not necessary for overload-induced muscle glucose uptake or hypertrophic growth, and suggest that GLUT1, GLUT3, GLUT6 and/or GLUT10 mediate overload-induced glucose uptake.

  6. 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.

  7. [Risk assessment in upper limb overload].

    PubMed

    Martinelli, R; Casilli, A; Fanelli, C; Pizzuti, S; Tarquini, M; Tobia, L; Paoletti, A

    2007-01-01

    One of the most important factors of the work-related musculoskeletal disorders of the upper extremities (WMSDs) is the biomechanical overload. The purpose of this study is to evaluate the possibility to predict the upper limb repetitive stress, according to risk assessment procedures. In order to this aim, we gathered clinical-anamnestic data and risk assessment considerations of a cohort of workers in a car industry.

  8. Oxidative damage to rat brain in iron and copper overloads.

    PubMed

    Musacco-Sebio, Rosario; Ferrarotti, Nidia; Saporito-Magriñá, Christian; Semprine, Jimena; Fuda, Julián; Torti, Horacio; Boveris, Alberto; Repetto, Marisa G

    2014-08-01

    This study reports on the acute brain toxicity of Fe and Cu in male Sprague-Dawley rats (200 g) that received 0 to 60 mg kg(-1) (ip) FeCl2 or CuSO4. Brain metal contents and time-responses were determined for rat survival, in situ brain chemiluminescence and phospholipid and protein oxidation products. Metal doses hyperbolically defined brain metal content. Rat survival was 91% and 60% after Fe and Cu overloads. Brain metal content increased from 35 to 114 μg of Fe per g and from 3.6 to 34 μg of Cu per g. Brain chemiluminescence (10 cps cm(-2)) increased 3 and 2 times after Fe and Cu overloads, with half maximal responses (C50) of 38 μg of Fe per g of brain and 15 μg of Cu per g of brain, and with half time responses (t1/2) of 12 h for Fe and 20 h for Cu. Phospholipid peroxidation increased by 56% and 31% with C50 of 40 μg of Fe per g and 20 μg of Cu per g and with t1/2 of 9 h and 14 h. Protein oxidation increased by 45% for Fe with a C50 of 40 μg of Fe per g and 18% for Cu with a C50 of 10 μg of Cu per g and a t1/2 of 12 h for both metals. Fe and Cu brain toxicities are likely mediated by Haber-Weiss type HO˙ formation with subsequent oxidative damage.

  9. 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.

  10. Comparison of acute and chronic traumatic brain injury using semi-automatic multimodal segmentation of MR volumes.

    PubMed

    Irimia, Andrei; Chambers, Micah C; Alger, Jeffry R; Filippou, Maria; Prastawa, Marcel W; Wang, Bo; Hovda, David A; Gerig, Guido; Toga, Arthur W; Kikinis, Ron; Vespa, Paul M; Van Horn, John D

    2011-11-01

    Although neuroimaging is essential for prompt and proper management of traumatic brain injury (TBI), there is a regrettable and acute lack of robust methods for the visualization and assessment of TBI pathophysiology, especially for of the purpose of improving clinical outcome metrics. Until now, the application of automatic segmentation algorithms to TBI in a clinical setting has remained an elusive goal because existing methods have, for the most part, been insufficiently robust to faithfully capture TBI-related changes in brain anatomy. This article introduces and illustrates the combined use of multimodal TBI segmentation and time point comparison using 3D Slicer, a widely-used software environment whose TBI data processing solutions are openly available. For three representative TBI cases, semi-automatic tissue classification and 3D model generation are performed to perform intra-patient time point comparison of TBI using multimodal volumetrics and clinical atrophy measures. Identification and quantitative assessment of extra- and intra-cortical bleeding, lesions, edema, and diffuse axonal injury are demonstrated. The proposed tools allow cross-correlation of multimodal metrics from structural imaging (e.g., structural volume, atrophy measurements) with clinical outcome variables and other potential factors predictive of recovery. In addition, the workflows described are suitable for TBI clinical practice and patient monitoring, particularly for assessing damage extent and for the measurement of neuroanatomical change over time. With knowledge of general location, extent, and degree of change, such metrics can be associated with clinical measures and subsequently used to suggest viable treatment options.

  11. Increase in volume of dental local anaesthetic solution while maintaining the tissue lidocaine and adrenaline concentration does not increase acute postoperative pain after gingivectomy.

    PubMed

    Hanvold, K I; Vigen, E C; Jorkjend, L; Aass, A M; Skoglund, L A

    2008-04-01

    A randomised, single-blind, within-patient, crossover study was done in 45 patients (29 women and 16 men, mean age 49 years, range 37-71) who had bilateral "identical" gingivectomies. On one occasion a standard volume of local anaesthetic containing 2% lidocaine and 1/80,000 adrenaline was infiltrated into the mucosal tissue before operation. On the other, double the standard volume with 1% lidocaine and 1/160,000 adrenaline was infiltrated. The intensity of postoperative pain was recorded by the patients on a 100 mm visual analogue scale every hour for an 11-hour observation period. The time courses and the sum of pain intensity after injection of the double and standard volumes did not differ significantly. Doubling the volume of local anaesthetic while maintaining the total lidocaine and adrenaline concentration that was infiltrated does not influence the intensity of acute pain after gingivectomy.

  12. Acute responses of circulating microRNAs to low-volume sprint interval cycling

    PubMed Central

    Cui, Shu Fang; Li, Wei; Niu, Jie; Zhang, Chen Yu; Chen, Xi; Ma, Ji Zheng

    2015-01-01

    Low-volume high-intensity interval training is an efficient and practical method of inducing physiological responses in various tissues to develop physical fitness and may also change the expression of circulating microRNAs (miRNAs). The purpose of the present study was to examine whether miRNAs for muscle, heart, somatic tissue and metabolism were affected by 30-s intervals of intensive sprint cycling. We also examined the relationship of these miRNAs to conventional biochemical and performance indices. Eighteen healthy young males performed sprint interval cycling. Circulating miRNAs in plasma were detected using TaqMan-based quantitative PCR and normalized to Let-7d/g/i. In addition, we determined the levels of insulin-like growth factor-I, testosterone and cortisol, and anaerobic capacity. Compared to plasma levels before exercise muscle-specific miR-1 (0.12 ± 0.02 vs. 0.09 ± 0.02), miR-133a (0.46 ± 0.10 vs. 0.31 ± 0.06), and miR-133b (0.19 ± 0.02 vs. 0.10 ± 0.01) decreased (all P < 0.05), while miR-206 and miR-499 remained unchanged. The levels of metabolism related miR-122 (0.62 ± 0.07 vs. 0.34 ± 0.03) and somatic tissues related miR-16 (1.74 ± 0.27 vs. 0.94 ± 0.12) also decreased (both P < 0.05). The post-exercise IGF-1 and cortisol concentrations were significantly increased, while testosterone concentrations did not. Plasma levels of miR-133b correlated to peak power (r = 0.712, P = 0.001) and miR-122 correlated to peak power ratio (r = 0.665, P = 0.003). In conclusion sprint exercise provokes genetic changes for RNA related to specific muscle or metabolism related miRNAs suggesting that miR-133b and miR-122 may be potential useful biomarkers for actual physiological strain or anaerobic capacity. Together, our findings on the circulating miRNAs may provide new insight into the physiological responses that are being performed during exercise and delineate mechanisms by which exercise confers distinct phenotypes and improves performance. PMID

  13. Information Technology - Information Overload for Strategic Leaders

    DTIC Science & Technology

    2007-11-02

    Information Overload for Strategic Leaders 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) Anthony Cotton 5d...PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) U.S. Army War College,Carlisle Barracks,Carlisle...PA,17013-5050 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM( S ) 11

  14. Low Carbohydrate/High Fat Diet Attenuates Pressure Overload Induced Ventricular Remodeling and Dysfunction

    PubMed Central

    Duda, Monika K.; O’Shea, Karen M.; Lei, Biao; Barrows, Brian R.; Azimzadeh, Agnes M.; McElfresh, Tracy E.; Hoit, Brian D.; Kop, Willem J.; Stanley, William C.

    2009-01-01

    Background It is not known how carbohydrate and fat intake impact the development of left ventricular (LV) hypertrophy and contractile dysfunction in response to pressure overload. We hypothesized that a low carbohydrate/high fat diet prevents LV hypertrophy and dysfunction compared to high carbohydrate diets. Methods and Results Rats were fed high carbohydrate diets comprised of either starch or sucrose, or a low carbohydrate/high fat diet, and underwent abdominal aortic banding (AAB) for two months. AAB increased LV mass with all diets. LV end diastolic and systolic volumes, and the ratio of the mRNA for myosin heavy chainβ/α were increased with both high carbohydrate diets, but not with the low carbohydrate/high fat diet. Circulating levels of insulin and leptin, both stimulants for cardiac growth, were lower, and free fatty acids higher, with the low carbohydrate/high fat diet compared to high carbohydrate diets. Among AAB animals LV volumes were positively correlated with insulin, and LV mass correlated with leptin. Conclusion A low carbohydrate/high fat diet attenuated pressure overload-induced LV remodeling compared to high carbohydrate diets. This effect corresponded to lower insulin and leptin concentrations, suggesting they may contribute to the development of LV hypertrophy and dysfunction under conditions of pressure overload. PMID:18474346

  15. Global and regional assessment of sustained inflation pressure-volume curves in patients with acute respiratory distress syndrome.

    PubMed

    Becher, Tobias; Rostalski, Philipp; Kott, Matthias; Adler, Andy; Schadler, Dirk; Weiler, Norbert; Frerichs, Inez

    2017-03-24

    Static or quasi-static pressure-volume (P-V) curves can be used to determine the lung mechanical properties of patients suffering from acute respiratory distress syndrome (ARDS). According to the traditional interpretation, lung recruitment occurs mainly below the lower point of maximum curvature (LPMC) of the inflation P-V curve. Although some studies have questioned this assumption, setting of positive end-expiratory pressure 2 cmH2O above the LPMC was part of a "lung-protective" ventilation strategy successfully applied in several clinical trials. The aim of our study was to quantify the amount of unrecruited lung at different clinically relevant points of the P-V curve. P-V curves and electrical impedance tomography (EIT) data from 30 ARDS patients were analysed. We determined the regional opening pressures for every EIT image pixel and fitted the global P-V curves to five sigmoid model equations to determine the LPMC, inflection point (IP) and upper point of maximal curvature (UPMC). Points of maximal curvature and IP were compared between the models by one-way analysis of variance (ANOVA). The percentages of lung pixels remaining closed ("unrecruited lung") at LPMC, IP and UPMC were calculated from the number of lung pixels exhibiting regional opening pressures higher than LPMC, IP and UPMC and were also compared by one-way ANOVA. As results, we found a high variability of LPMC values among the models, a smaller variability of IP and UPMC values. We found a high percentage of unrecruited lung at LPMC, a small percentage of unrecruited lung at IP and no unrecruited lung at UPMC. Our results confirm the notion of ongoing lung recruitment at pressure levels above LPMC for all investigated model equations and highlight the importance of a regional assessment of lung recruitment in patients with ARDS.

  16. Effects of reduced tidal volume ventilation on pulmonary function in mice before and after acute lung injury.

    PubMed

    Thammanomai, Apiradee; Majumdar, Arnab; Bartolák-Suki, Erzsébet; Suki, Béla

    2007-11-01

    We investigated the influence of load impedance on ventilator performance and the resulting effects of reduced tidal volume (Vt) on lung physiology during a 30-min ventilation of normal mice and 10 min of additional ventilation following lavage-induced injury at two positive end-expiratory pressure (PEEP) levels. Respiratory mechanics were regularly monitored, and the lavage fluid was tested for the soluble E-cadherin, an epithelial cell adhesion molecule, and surfactant protein (SP) B. The results showed that, due to the load dependence of the delivered Vt from the small-animal ventilator: 1) uncontrolled ventilation in normal mice resulted in a lower delivered Vt (6 ml/kg at 3-cmH(2)O PEEP and 7 ml/kg at 6-cmH(2)O PEEP) than the prescribed Vt (8 ml/kg); 2) at 3-cmH(2)O PEEP, uncontrolled ventilation in normal mice led to an increase in lung parenchymal functional heterogeneity, a reduction of SP-B, and an increase in E-cadherin; 3) at 6-cmH(2)O PEEP, ventilation mode had less influence on these parameters; and 4) in a lavage model of acute respiratory distress syndrome, delivered Vt decreased to 4 ml/kg from the prescribed 8 ml/kg, which resulted in severely compromised lung function characterized by increases in lung elastance, airway resistance, and alveolar tissue heterogeneity. Furthermore, the low Vt ventilation also resulted in poor survival rate independent of PEEP. These results highlight the importance of delivering appropriate Vt to both the normal and injured lungs. By leaving the Vt uncompensated, it can significantly alter physiological and biological responses in mice.

  17. [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.

  18. Infrared thermography and overloaded neutral conductors

    NASA Astrophysics Data System (ADS)

    McComb, John; Niebla, Hector E.

    1999-03-01

    Present findings of two recent case studies. One involves transformer failures on three computer-stores within eight hours of their grand opening. The second discusses the findings during an infrared thermography-training course for electric utility engineers of a transformer vault serving an industrial customer. Both of these deal with overloaded neutral conductors. Historically, the average neutral conductor carried only the imbalance of the current between the phases of a three-phase system. This current was typically small in relation to the load being served. In fact, for economic reasons many neutrals were installed smaller than their associated phase conductors. Today however, certain types of loads (non-linear loads such as computers) and certain transformer connections (4 bushing single phase with a collector bus) cause the neutral to have up to three times as much amperage as the phase conductors. This paper will discuss the conditions under which such loading occurs and further investigate steps that can be taken/recommended should an infrared test indicate an overloaded neutral conductor.

  19. 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

  20. Iron overload in patients with transfusion dependent myelodisplastic syndrome.

    PubMed

    Genadieva-Stavrik, S; Georgievski, B; Stojanoski, Z; Krstveska-Balkanov, S; Pivkova, A; Trajkova, M; Genadieva-Dimitrova, M; Serafimoski, V

    2011-01-01

    The myelodisplastic syndrome is a heterogeneous group of diseases, characterised by ineffective and dysplastic haematopoesis and pancytopenia in the peripheral blood, followed by progressive disturbance of differentiation of the haematopoetic stem cell, resulting in evolution of the disease towards acute leukaemia. According to the latest WHO classification, the term myelodisplastic syndrome includes diseases with an indolent course, as well as diseases with a fast evolution towards acute leukaemia. Because of this diversity, haematologists base their therapeutic decisions on prognostic scoring systems which incorporate all the significant factors with an influence on survival in this group of patients with myelodisplastic syndrome. Bearing in mind that anaemia is the most frequent form of cytopenia in patients with myelodisplastic syndrome, it is common that at some point of the disease almost every patient with myelodisplastic syndrome is transfusion-dependent. Frequently applied transfusions secure the correction of anaemia in these patients, giving them a good quality of life, but at the same time endangering them with the potential threat of iron overload, when the physiological mechanisms of iron excretion from the organism become insufficient. There is a clear correlation between transfusion dependence and the overall survival in patients with myelodisplastic syndrome. Chelators secure the lowering of the iron surfeit and are indicated in transfusion-dependant patients with myelodisplastic syndrome ( need for two blood units monthly, during one year ), when the ferritin level increases over 1000, in patients who are candidates for transplantation as well as in patients from good prognostic groups with median survival over one year. The therapy with chelators lasts as long as the patient is transfusion-dependant.

  1. 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

  2. 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.

  3. Dysmetabolic Hyperferritinemia: All Iron Overload Is Not Hemochromatosis

    PubMed Central

    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

  4. 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.

  5. 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.

  6. Edge overload breakdown in evolving networks

    NASA Astrophysics Data System (ADS)

    Holme, Petter

    2002-09-01

    We investigate growing networks based on Barabási and Albert's algorithm for generating scale-free networks, but with edges sensitive to overload breakdown. The load is defined through edge betweenness centrality. We focus on the situation where the average number of connections per vertex is, like the number of vertices, linearly increasing in time. After an initial stage of growth, the network undergoes avalanching breakdowns to a fragmented state from which it never recovers. This breakdown is much less violent if the growth is by random rather than by preferential attachment (as defines the Barabási and Albert model). We briefly discuss the case where the average number of connections per vertex is constant. In this case no breakdown avalanches occur. Implications to the growth of real-world communication networks are discussed.

  7. Renal distribution volumes of indocyanine green, ( 51 Cr)EDTA, and 24 Na in man during acute renal failure after shock. Implications for the pathogenesis of anuria.

    PubMed

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

    1973-02-01

    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, [(51)Cr]EDTA, and (24)Na 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 (24)Na 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.

  8. 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

  9. What do nurses mean by workload and work overload?

    PubMed

    Gaudine, A P

    2000-01-01

    This paper describes 31 nurses' views of workload and work overload, identifying ten dimensions of workload and four dimensions of work overload. Findings suggest that researchers and nurse administrators do not include all of the dimensions that nurses think of when they use the word "workload". Nurse administrators who listen to nurses' experience of workload may be able to find strategies to help nurses deal with their workload. The theme of lack of control ran through the nurses' accounts of work overload. To retain nurses, employers need to allow nurses some control over their workload and some time to include in their nursing the things they enjoy the most.

  10. 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.

  11. High-volume hemofiltration and prone ventilation in subarachnoid hemorrhage complicated by severe acute respiratory distress syndrome and refractory septic shock

    PubMed Central

    Cornejo, Rodrigo; Romero, Carlos; Ugalde, Diego; Bustos, Patricio; Diaz, Gonzalo; Galvez, Ricardo; Llanos, Osvaldo; Tobar, Eduardo

    2014-01-01

    We report the successful treatment of two patients with aneurismal subarachnoid hemorrhage complicated by severe respiratory failure and refractory septic shock using simultaneous prone position ventilation and high-volume hemofiltration. These rescue therapies allowed the patients to overcome the critical situation without associated complications and with no detrimental effects on the intracranial and cerebral perfusion pressures. Prone position ventilation is now an accepted therapy for severe acute respiratory distress syndrome, and high-volume hemofiltration is a non-conventional hemodynamic support that has several potential mechanisms for improving septic shock. In this manuscript, we briefly review these therapies and the related evidence. When other conventional treatments are insufficient for providing safe limits of oxygenation and perfusion as part of basic neuroprotective care in subarachnoid hemorrhage patients, these rescue therapies should be considered on a case-by-case basis by an experienced critical care team. PMID:25028955

  12. 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

  13. Iron overload: what is the role of public health?

    PubMed

    Hulihan, Mary M; Sayers, Cindy A; Grosse, Scott D; Garrison, Cheryl; Grant, Althea M

    2011-12-01

    Hereditary hemochromatosis type 1, also known as hereditary hemochromatosis classical (HHC), is an iron overload disorder associated, in most cases, with mutations of the hemochromatosis (HFE) gene. Although suggested algorithms for diagnosing iron overload are available, there are still questions about options for genetic and biochemical screening for hemochromatosis and duration of treatment. This article provides a summary of an expert workgroup meeting convened on September 24-25, 2009, entitled "Iron Overload: What is the Role of Public Health?" The purpose of the meeting was to enable subject matter experts to share their most recent clinical and scientific iron overload information and to facilitate the discussion of future endeavors, with special emphasis on the role of public health in this field. The two main topics were the research priorities of the field, including clinical, genetic, and public health issues, and the concerns about the validity of current screening recommendations for the condition.

  14. 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.

  15. Continuous peritoneal dialysis in acute renal failure from severe falciparum malaria.

    PubMed

    Indraprasit, S; Charoenpan, P; Suvachittanont, O; Mavichak, V; Kiatboonsri, S; Tanomsup, S

    1988-03-01

    Severe falciparum malaria complicated by acute renal failure resulted in very high mortality. Ten patients with acute renal failure from falciparum malaria (infected rbc up to 80%) were continuously dialysed using Tenckhoff peritoneal catheter. Five were oliguric and BUN was maintained between 60 to 80 mg/dl (21.4 to 28.6 mmol/l) by hourly 1 to 1.5 liter dialysate exchange during the acute phase. The peritoneal urea clearance (mean +/- SD) was 12.1 +/- 1.2 ml/min with urea nitrogen removal of 13.4 +/- 2.3 g/day. In nonoliguric cases dialysis was also needed for additional removal of waste products since the remaining renal function could not cope with the hypercatabolic state. Peritoneal glucose absorption (135 to 565 g/day) gave considerable caloric supply without volume load and also contributed to the prevention of hypoglycemia. Varying degree of acute respiratory failure developed in all patients with 5 cases (2 oliguric and 3 nonoliguric) progressing to pulmonary edema. Swan-Ganz catheterization and hemodynamic study suggested the role of increased capillary permeability and volume overload from endogenous water formation in the development of pulmonary complication. Continuous removal of fluid and waste products minimized these problems and may prevent the progression of respiratory failure. One patient died of severe sepsis and the other nine survived. This study showed the beneficial contribution of continuous peritoneal dialysis in the management of acute renal failure from severe falciparum malaria.

  16. New rat models of iron sucrose-induced iron overload.

    PubMed

    Vu'o'ng Lê, Bá; Khorsi-Cauet, Hafida; Villegier, Anne-Sophie; Bach, Véronique; Gay-Quéheillard, Jérôme

    2011-07-01

    The majority of murine models of iron sucrose-induced iron overload were carried out in adult subjects. This cannot reflect the high risk of iron overload in children who have an increased need for iron. In this study, we developed four experimental iron overload models in young rats using iron sucrose and evaluated different markers of iron overload, tissue oxidative stress and inflammation as its consequences. Iron overload was observed in all iron-treated rats, as evidenced by significant increases in serum iron indices, expression of liver hepcidin gene and total tissue iron content compared with control rats. We also showed that total tissue iron content was mainly associated with the dose of iron whereas serum iron indices depended essentially on the duration of iron administration. However, no differences in tissue inflammatory and antioxidant parameters from controls were observed. Furthermore, only rats exposed to daily iron injection at a dose of 75 mg/kg body weight for one week revealed a significant increase in lipid peroxidation in iron-treated rats compared with their controls. The present results suggest a correlation between iron overload levels and the dose of iron, as well as the duration and frequency of iron injection and confirm that iron sucrose may not play a crucial role in inflammation and oxidative stress. This study provides important information about iron sucrose-induced iron overload in rats and may be useful for iron sucrose therapy for iron deficiency anemia as well as for the prevention and diagnosis of iron sucrose-induced iron overload in pediatric patients.

  17. Dynamic Operator Overload Estimation during Supervisory Control of Multiple UAVs

    DTIC Science & Technology

    2014-01-01

    1 Dynamic Operator Overload Estimation during Supervisory Control of Multiple UAVs Leonard A. Breslow1, Daniel Gartenberg2, J. Malcolm McCurry3...we introduced a dynamic model of operator overload that predicts failures in supervisory control in real time, based on fluctuations in time...whether the dynamic variability of performance during the course of a particular task can be predicted by the same, or Report Documentation Page Form

  18. Associations between Lifestyle Factors and Iron Overload in Korean Adults

    PubMed Central

    2016-01-01

    It has been suggested that iron overload, which indicates the accumulation of iron, generates cellular reactive oxygens and causes peroxide damages to the body. Such oxidative stresses, in a broader context, are also caused by lifestyles such as alcohol consumption and smoking. However, there are limited data on the association between these lifestyle factors and internal iron overload. In present study, we evaluated associations between lifestyle factors, such as smoking status, alcohol consumption, and physical activity, and serum markers of iron overload. In a population-based cross-sectional study including 2,347 Korean men and women aged 49–79 years, we assessed serum transferrin saturation (TSAT) levels and defined iron overload as TSAT levels > 50% for men and > 45% for women. After excluding persons with chronic diseases and iron deficiency, multivariate odds ratio (OR) and its 95% confidence interval (CI) were estimated to evaluate associations between lifestyle factors and iron overload in 1,973 participants. In all participants, we examined a significantly positive association between heavy alcohol consumption (> 30 g/day) and iron overload; heavy drinkers showed 1.6-fold higher OR (95% CI, 1.11–2.36) than non-drinkers. Stratified analysis by sex showed that this association was significant only among men. In addition, we observed a potential association between heavy smoking > 10 cigarettes/day and iron overload (p = 0.07). In stratified analysis by sex, we examined a significant association between smoking and iron overload only among women; former or current smokers had 1.9-fold higher OR (95% CI, 1.01–3.63) than never-smoker. Our findings suggest that heavy alcohol consumption and smoking may worsen iron accumulation in the body. PMID:27812516

  19. 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

  20. 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.

  1. Influence of training volume and acute physical exercise on the homocysteine levels in endurance-trained men: interactions with plasma folate and vitamin B12.

    PubMed

    König, D; Bissé, E; Deibert, P; Müller, H-M; Wieland, H; Berg, A

    2003-01-01

    The interrelation between physical exercise and plasma levels of homocysteine (Hcy), vitamin B(12), and folic acid has not been examined. Therefore, we investigated the influence of extensive endurance training and acute intense exercise on plasma concentrations of total Hcy, vitamin B(12), and folic acid in 42 well-trained male triathletes. Examinations and blood sampling took place before and after a 30-day endurance training period as well as before and 1 and 24 h after a competitive exercise (sprint triathlon). Following the training period, no significant change in Hcy levels could be detected for the whole group. Subgroup analysis in quartiles of training volume revealed that - as compared with the lowest quartile (low-training group: 9.1 h training/week) - athletes in the highest training quartile (high-training group: 14.9 h training/week) exhibited a significant decrease in Hcy levels (from 12.7 +/- 2.3 to 11.7 +/- 2.4 micromol/l as compared with levels of 12.5 +/- 1.5 and 12.86 +/- 1.5 micromol/l in the low-training group; p < 0.05). The plasma folate levels were significantly higher in the high-training group at all points of examination (p < 0.05). 1 h and 24 h after competition, the Hcy concentration increased in all athletes independent of the previous training volume (24 h: 12.3 +/- 1.8 vs. 13.5 +/- 2.6 micromol/l; p < 0.001), although the increase was decisively stronger in the low-training group. 1 h after competition, the plasma folate concentration increased (7.03 +/- 2.1 vs. 8.33 +/- 2.1 ng/ml; p < 0.05) in all athletes. Multivariate analysis showed that the exercise-induced increase in the Hcy levels was dependent on baselines levels of folate and training volume, but not on the vitamin B(12) levels. In conclusion, although intense exercise acutely increased the Hcy levels, chronic endurance exercise was not associated with higher Hcy concentrations. Moreover, athletes with the highest training volume, exhibiting also the highest plasma folate

  2. 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

  3. 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.

  4. The Impact of a Targeted Training Program on E-Mail System Processing Capabilities and Self-Perception of E-Mail Overload

    ERIC Educational Resources Information Center

    Einstein, Michael M.

    2014-01-01

    As business e-mail volumes continue to grow and employees spend increasingly larger portions of their day processing e-mail, there is strong evidence of the negative impacts of e-mail processing, especially with respect to e-mail overload. This study sought to determine whether a training program focused on select e-mail features and processing…

  5. 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.

  6. Differential effects of iron overload on GST isoform expression in mouse liver and kidney and correlation between GSTA4 induction and overproduction of free radicles.

    PubMed

    Desmots, Fabienne; Rissel, Mary; Pigeon, Christelle; Loyer, Pascal; Loréal, Olivier; Guillouzo, André

    2002-01-01

    We have investigated the effect of iron overload on the expression of mouse GSTA1, A4, M1, and P1 in liver, the main iron storage site during iron overload, and in kidney. In iron-overloaded animals, mRNA and protein levels of GSTA1, A4, and M1 were increased in liver. In kidney, GSTA4 protein level was also increased while, unexpectedly, GSTA1 and M1 expression was strongly decreased. We showed, by immunohistochemistry, that GSTA4 was more abundant in hepatocytes of periportal areas and in convoluted proximal tubular cells in normal liver and kidney, respectively. In iron-overloaded mice, GSTA4 staining was more intense in cells that preferentially accumulated iron, and conjugation of 4-hydroxynonenal, a specific substrate of GSTA4, was enhanced in both organs. Moreover an acute exposure of primary cultures of mouse hepatocytes to iron-citrate strongly induced oxidative stress and cellular injury and resulted in an increase in GSTA4 expression, while cotreatment with iron-citrate and either desferrioxamine or vitamin E prevented both toxicity and GSTA4 induction. These data demonstrate that GSTA1 and M1 are differentially regulated in liver and kidney while GSTA4 is induced in both organs during iron overload. Moreover, they support the view that iron-induction of GSTA4 is related to an overproduction of free radicals.

  7. Study of TiO2 P25 nanoparticles genotoxicity on lung, blood and liver cells in lung overload and non-overload conditions after repeated respiratory exposure in rats.

    PubMed

    Relier, Charlène; Dubreuil, Marielle; Lozano Garcia, Omar; Cordelli, Eugenia; Mejia, Jorge; Eleuteri, Patrizia; Robidel, Franck; Loret, Thomas; Pacchierotti, Francesca; Lucas, Stéphane; Lacroix, Ghislaine; Trouiller, Bénédicte

    2017-01-13

    Inhaled titanium dioxide (TiO2) nanoparticles (NPs) can have negative health effects, and have been shown to cause respiratory tract cancer in rats. Inflammation has been linked to oxidative stress, and both have been described as possible mechanisms for genotoxicity of NPs, but rarely examined side-by-side in animal studies. In the present study, a wide range of complementary endpoints have been performed to study TiO2 P25 NP-induced genotoxicity in lung overload and non-overload conditions. Additionally, lung burden, inflammation, cytotoxicity and oxidative stress have also been evaluated in order to link genotoxicity with these responses. To assess quick and delayed responses after recovery, endpoints were evaluated at two time points: 2 hours and 35 days after 3 repeated instillations. This study confirmed the previously described lung overload threshold at approximately 200-300 cm(2) of lung burden for total particle surface area lung deposition or 4.2 µL/kg for volume-based cumulative lung exposure dose, above which lung clearance is impaired and inflammation is induced. Our results went on to show that these overload doses induced delayed genotoxicity in lung, associated with persistent inflammation only at the highest dose. The lowest tested doses had no toxicity or genotoxicity effects in the lung. In blood, no lymphocyte DNA damage, erythrocytes chromosomal damage or gene mutation could be detected. Our data also demonstrated that only overload doses induced liver DNA lesions irrespective of the recovery time. Tested doses of TiO2 P25 NPs did not induce glutathione changes in lung, blood or liver at both recovery times.

  8. Toxicity of TNT Wastewaters to Aquatic Organisms. Volume 1. Acute Toxicity of LAP Wastewater and 2,4,6-Trinitrotoluene

    DTIC Science & Technology

    1983-03-01

    used to assess the adequacy of current pollution abatement technologies and thus influence research and development in this area. This report...wastewater samples, was defined as a 1.6-to-I mixture o! TNT and RDX. "The results of flow-through acute toxicity terzs with the inverte - brate Daphniamagna...The "unadjusted" confidence interval for the LCSO is derived by inverting the likelihood ratio test for determining whether any specified

  9. 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

  10. [Hemochromatosis: one form of iron-overload diseases].

    PubMed

    Szalay, Ferenc

    2013-07-21

    Iron-overload diseases are typically insidious, causing progressive and irreversible organ injury before clinical symptoms develop. Some iron-overload diseases as HFE-associated hemochromatosis and beta-thalassemia are quite common, whereas others are very rare. Early diagnosis is important since iron toxicity can be attenuated or prevented. Significant progress of our knowledge on iron metabolism developed in the past years. We learned a lot about HFE gene mutations, function of ferroportin and hepcidin, the hypoferremia hormone produced by the liver. However, many questions are still open. Special forms of localized iron overload are the Hallervorden-Spatz syndrome and pantothenate kinase gene mutation associated neurodegeneration causing progressive extrapyramidal movement disorders. Neonatal hemochromatosis is a severe systemic iron-overload disorder due to gestational alloimmune liver disease caused by transplacental maternal IgG directed against the fetal liver. This review article gives an overview on iron metabolism and iron-overload disease. Pathomechanism, diagnosis and treatment of hereditary hemochromatosis are discussed.

  11. Effect of Increased Neutrophil-to-Lymphocyte Ratio (NLR) and Decreased Mean Platelet Volume (MPV) Values on Inflammation in Acute Mania

    PubMed Central

    MAYDA, Hasan; AHSEN, Ahmet; BAĞCIOĞLU, Erman; ÖZTÜRK, Ahmet; BAHÇECİ, Bülent; SOYUÇOK, Etem; BAŞPINAR, Erol; ULU, Memnune Sena

    2016-01-01

    Introduction The neutrophil-to-lymphocyte ratio (NLR) and mean platelet volume (MPV) are simple, low-cost, and useful inflammatory markers detected in routine complete blood count (CBC), and their use has recently become widespread. In this study, we aimed to investigate the presence of an inflammatory state in manic patients on the basis of NLR and MPV values. Methods This retrospective study was performed on 76 patients with acute mania who were admitted to the Inpatients Psychiatry Clinic of Afyon Kocatepe University Hospital in Turkey. Diagnoses were based on Diagnostic and Statistical Manuel of Mental disorder (DSM-IV). The control group consisted of 74 healthy individuals recruited from the community. They were age- and sex-matched with the study group. Results NLR values of the manic patient group were 2.2±1.4 and those of the control group were 1.6±0.5. NLR values were significantly higher (p=0.004) and MPV values were significantly lower in the manic patient group than in the control group (10.0±1.2 vs. 10.9±2.3, p=0.027). Conclusion Increased NLR and decreased MPV levels may reflect inflammation in manic patients, and inflammation may play a role in the complex pathophysiology of acute mania. PMID:28360805

  12. 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.

  13. Cardiac iron overload in thalassemic patients: an endomyocardial biopsy study.

    PubMed

    Lombardo, T; Tamburino, C; Bartoloni, G; Morrone, M L; Frontini, V; Italia, F; Cordaro, S; Privitera, A; Calvi, V

    1995-09-01

    Secondary heart failure induced by organ siderosis is the main cause of death in patients affected by thalassemia major. At present it cannot be predicted whether heart siderosis is correlated with iron overload and little is known about the real cardiac histological pattern of post transfusional hemochromatosis in patients with thalassemia major and intermedia. The study aim was to evaluate cardiac iron overload by non invasive and invasive techniques. Fifteen thalassemic patients were investigated and endomyocardial biopsy performed in ten revealed different grades of endomyocardial iron overload with histochemical positivity. Non invasive techniques are not able to furnish an exact picture of the cardiac hemochromatosis. There was a significant correlation between serum ferritin and myocardial iron grade. Patients with elevated ferritin levels and poor compliance to chelating therapy are at high risk of severe heart hemochromatosis. It was seen that endomyocardial biopsy is a useful tool in studying myocardial iron.

  14. Acute aortocaval fistula: role of low perfusion pressure and subendocardial remodeling on left ventricular function

    PubMed Central

    Mazzo, Flávia R R; de Carvalho Frimm, Clovis; Moretti, Ana Iochabel S; Guido, Maria C; Koike, Marcia K

    2013-01-01

    The experimental model of aortocaval fistula is a useful model of cardiac hypertrophy in response to volume overload. In the present study it has been used to investigate the pathologic subendocardial remodeling associated with the development of heart failure during the early phases (day 1, 3, and 7) following volume overload. Compared with sham treated rats, aortocaval fistula rats showed lower systemic blood pressure and higher left ventricular end-diastolic pressure This resulted in lower coronary driving pressure and left ventricular systolic and diastolic dysfunction. Signs of myocyte necrosis, leukocyte cell infiltration, fibroplasia and collagen deposition appeared sequentially in the subendocardium where remodeling was more prominent than in the non-subendocardium. Accordingly, increased levels of TNF-alpha, IL-1 beta, and IL-6, and enhanced MMP-2 activity were all found in the subendocardium of rats with coronary driving pressure ≤60 mmHg. The coronary driving pressure was inversely correlated with MMP-2 activity in subendocardium in all time-points studied, and blood flow in this region showed positive correlation with systolic and diastolic function at day 7. Thus the predominant subendocardial remodeling that occurs in response to low myocardial perfusion pressure during the acute phases of aortocaval fistula contributes to early left ventricular dysfunction. PMID:23593971

  15. Decongestive treatment of acute decompensated heart failure: cardiorenal implications of ultrafiltration and diuretics.

    PubMed

    Freda, Benjamin J; Slawsky, Mara; Mallidi, Jaya; Braden, Gregory L

    2011-12-01

    In patients with acute decompensated heart failure (ADHF), treatment aimed at adequate decongestion of the volume overloaded state is essential. Despite diuretic therapy, many patients remain volume overloaded and symptomatic. In addition, adverse effects related to diuretic treatment are common, including worsening kidney function and electrolyte disturbances. The development of decreased kidney function during treatment affects the response to diuretic therapy and is associated with important clinical outcomes, including mortality. The occurrence of diuretic resistance and the morbidity and mortality associated with diuretic therapy has stimulated interest to develop effective and safe treatment strategies that maximize decongestion and minimize decreased kidney function. During the last few decades, extracorporeal ultrafiltration has been used to remove fluid from diuretic-refractory hypervolemic patients. Recent clinical studies using user-friendly machines have suggested that ultrafiltration may be highly effective for decongesting patients with ADHF. Many questions remain regarding the comparative impact of diuretics and ultrafiltration on important clinical outcomes and adverse effects, including decreased kidney function. This article serves as a summary of key clinical studies addressing these points. The overall goal is to assist practicing clinicians who are contemplating the use of ultrafiltration for a patient with ADHF.

  16. 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

  17. 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

  18. 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.

  19. Comparison of epicardial fat volume by computed tomography in black versus white patients with acute chest pain.

    PubMed

    Apfaltrer, Paul; Schindler, Andreas; Schoepf, U Joseph; Nance, John W; Tricarico, Francesco; Ebersberger, Ullrich; McQuiston, Andrew D; Meyer, Mathias; Henzler, Thomas; Schoenberg, Stefan O; Bamberg, Fabian; Vliegenthart, Rozemarijn

    2014-02-01

    Disparities in the risk of coronary artery disease (CAD) between races may be influenced by differences in the thoracic adipose tissue. We compared computed tomography (CT)-derived volumes of epicardial adipose tissue (EAT), mediastinal adipose tissue (MAT), and pericoronary fat thickness (PFT) and correlations with CAD between black and white patients. This institutional review board-approved Health Insurance Portability and Accountability Act-compliant study included 372 age- and gender-matched black versus white patients (186 black, 54 ± 11 years, 50% men; 186 white, 54 ± 11 years, 50% men) who underwent CT for chest pain evaluation. EAT, MAT, and PFT were measured. The amount of coronary calcium was quantified as calcium score. CAD was defined as ≥50% coronary artery narrowing. EAT and MAT volumes were significantly lower in black than white patients (59 [twenty-fifth to seventy-fifth percentile 39 to 84] vs 97 [67 to 132] cm(3) and 44 [27 to 77] vs 87 [52 to 157] cm(3), for both p <0.001). Mean PFT in black patients was slightly lower than white patients (17.2 ± 3.2 vs 18.1 ± 3.4 mm, p <0.01). The relation between race and extent of adipose tissue remained significant after adjustment for cardiovascular risk factors. Significant correlations were observed between EAT and MAT volumes and calcium score in black and white patients (r = 0.19 to 0.26, p <0.01). For both races, the level of thoracic fat measurements was higher in present versus absent coronary calcification. A greater amount of thoracic fat was found with obstructive CAD only in white patients. In conclusion, CT-derived measurements of thoracic fat differ between symptomatic black and white patients, suggesting a differential relation between thoracic adipose tissue and CAD pathophysiology by race.

  20. 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.

  1. Resistance training using eccentric overload induces early adaptations in skeletal muscle size.

    PubMed

    Norrbrand, Lena; Fluckey, James D; Pozzo, Marco; Tesch, Per A

    2008-02-01

    Fifteen healthy men performed a 5-week training program comprising four sets of seven unilateral, coupled concentric-eccentric knee extensions 2-3 times weekly. While eight men were assigned to training using a weight stack (WS) machine, seven men trained using a flywheel (FW) device, which inherently provides variable resistance and allows for eccentric overload. The design of these apparatuses ensured similar knee extensor muscle use and range of motion. Before and after training, maximal isometric force (MVC) was measured in tasks non-specific to the training modes. Volume of all individual quadriceps muscles was determined by magnetic resonance imaging. Performance across the 12 exercise sessions was measured using the inherent features of the devices. Whereas MVC increased (P < 0.05) at all angles measured in FW, such a change was less consistent in WS. There was a marked increase (P < 0.05) in task-specific performance (i.e., load lifted) in WS. Average work showed a non-significant 8.7% increase in FW. Quadriceps muscle volume increased (P < 0.025) in both groups after training. Although the more than twofold greater hypertrophy evident in FW (6.2%) was not statistically greater than that shown in WS (3.0%), all four individual quadriceps muscles of FW showed increased (P < 0.025) volume whereas in WS only m. rectus femoris was increased (P < 0.025). Collectively the results of this study suggest more robust muscular adaptations following flywheel than weight stack resistance exercise supporting the idea that eccentric overload offers a potent stimuli essential to optimize the benefits of resistance exercise.

  2. Molten thermoplastic dripping behavior induced by flame spread over wire insulation under overload currents.

    PubMed

    He, Hao; Zhang, Qixing; Tu, Ran; Zhao, Luyao; Liu, Jia; Zhang, Yongming

    2016-12-15

    The dripping behavior of the molten thermoplastic insulation of copper wire, induced by flame spread under overload currents, was investigated for a better understanding of energized electrical wire fires. Three types of sample wire, with the same polyethylene insulation thickness and different core diameters, were used in this study. First, overload current effects on the transient one-dimensional wire temperature profile were predicted using simplified theoretical analysis; the heating process and equilibrium temperature were obtained. Second, experiments on the melting characteristics were conducted in a laboratory environment, including drop formation and frequency, falling speed, and combustion on the steel base. Third, a relationship between molten mass loss and volume variation was proposed to evaluate the dripping time and frequency. A strong current was a prerequisite for the wire dripping behavior and the averaged dripping frequency was found to be proportional to the square of the current based on the theoretical and experimental results. Finally, the influence of dripping behavior on the flame propagation along the energized electrical wire was discussed. The flame width, bright flame height and flame spreading velocity presented different behaviors.

  3. Peritoneal ultrafiltration for refractory fluid overload and ascites due to pulmonary arterial hypertension.

    PubMed

    Husain-Syed, Faeq; Muciño-Bermejo, María-Jimena; Ronco, Claudio; Seeger, Werner; Birk, Horst-Walter

    2015-01-01

    Pulmonary hypertension is a common finding in patients with advanced liver disease. Similarly, among patients with advanced pulmonary arterial hypertension, right heart failure leads to congestive hepatopathy. Diuretic resistant fluid overload in both advanced pulmonary hypertension and chronic liver disease is a demanding challenge for physicians. Venous congestion and ascites-induced increased intra-abdominal pressure are essential regarding recurrent hospitalization, morbidity and mortality. Due to impaired right-ventricular function, many patients cannot tolerate extracorporeal ultrafiltration. Peritoneal dialysis, a well-established, hemodynamically tolerated treatment for outpatients may be a good alternative to control fluid status. We present a patient with pulmonary arterial hypertension and congestive hepatopathy hospitalized for over 3 months due to ascites induced refractory volume overload treated with peritoneal ultrafiltration. We report the treatment benefits on fluid balance, cardiorenal and pulmonary function, as well as its safety. In conclusion, we report a case in which peritoneal ultrafiltration was an efficient treatment option for refractory ascites in patients with congestive hepatopathy.

  4. Tools to Reduce Overload in the School Social Worker Role

    ERIC Educational Resources Information Center

    Leyba, Erin Gleason

    2009-01-01

    This article addresses how school social workers can decrease overload in their roles. A two-step process of envisioning an ideal role is outlined: (1) indentifying priorities and activities that are effective or in need of expansion and (2) weeding out activities that could be done differently or no longer serve their purpose. The author…

  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 56.12001 - 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  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 56.12003 - 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...

  13. 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...

  14. 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...

  15. 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...

  16. Coping with Information Overload as Adaptive Behavior in Competitive Debate.

    ERIC Educational Resources Information Center

    Dudczak, Craig A.

    When the amount of available information exceeds the ability of the user to process it, "information overload" is created. In an attempt to maintain some control over the quantity of arguments they may face, debaters have developed adaptive behavior, primarily through the generic argument--any argument within a "deliverative"…

  17. 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

  18. Iron deficiency and iron overload: effects of diet and genes.

    PubMed

    Burke, W; Imperatore, G; Reyes, M

    2001-02-01

    Like most essential nutrients, Fe needs to be maintained in the body at a defined level for optimal health, with appropriate adaptation to varying Fe needs and supply. The primary mechanism for controlling Fe level is the regulation of Fe absorption. Several different proteins have been identified as contributors to the process. Despite a complex regulatory system, Fe disorders (both Fe deficiency and Fe overload) occur. Fe deficiency is a common problem worldwide, resulting from inadequate dietary Fe and blood loss. Complications include pre-term labour, developmental delay, and impaired work efficiency. No specific genetic syndromes causing isolated Fe deficiency have been described, but animal studies and clinical observations suggest that such a relationship may be a possibility. Conversely, the known causes of Fe overload are genetic. Fe overload is less common than Fe deficiency, but can result in serious medical complications, including cirrhosis, primary liver cancer, diabetes, cardiomyopathy and arthritis. The most common and best characterized syndrome of Fe overload is hereditary haemochromatosis (HHC), an autosomal recessive disorder. Mutations in the HFE protein cause HHC, but the clinical presentation is variable. Of particular interest is the factor that some FIFE genotypes appear to be associated with protection from Fe deficiency. Other genetic variants in the regulatory pathway may influence the likelihood of Fe deficiency and Fe overload. Studies of genetic variants in HFE and other regulatory proteins provide important tools for studying the biological processes in Fe regulation. This work is likely to lead to new insights into Fe disorders and potentially to new therapeutic approaches. It will not be complete, however, until coordinated study of both genetic and nutritional factors is undertaken.

  19. Rat liver antioxidant response to iron and copper overloads.

    PubMed

    Musacco-Sebio, Rosario; Saporito-Magriñá, Christian; Semprine, Jimena; Torti, Horacio; Ferrarotti, Nidia; Castro-Parodi, Mauricio; Damiano, Alicia; Boveris, Alberto; Repetto, Marisa G

    2014-08-01

    The rat liver antioxidant response to Fe and Cu overloads (0-60mg/kg) was studied. Dose- and time-responses were determined and summarized by t1/2 and C50, the time and the liver metal content for half maximal oxidative responses. Liver GSH (reduced glutathione) and GSSG (glutathione disulfide) were determined. The GSH content and the GSH/GSSG ratio markedly decreased after Fe (58-66%) and Cu (79-81%) loads, with t1/2 of 4.0 and 2.0h. The C50 were in a similar range for all the indicators (110-124μgFe/g and 40-50μgCu/g) and suggest a unique free-radical mediated process. Hydrophilic antioxidants markedly decreased after Fe and Cu (60-75%; t1/2: 4.5 and 4.0h). Lipophilic antioxidants were also decreased (30-92%; t1/2: 7.0 and 5.5h) after Fe and Cu. Superoxide dismutase (SOD) activities (Cu,Zn-SOD and Mn-SOD) and protein expression were adaptively increased after metal overloads (Cu,Zn-SOD: t1/2: 8-8.5h and Mn-SOD: t1/2: 8.5-8.0h). Catalase activity was increased after Fe (65%; t1/2: 8.5h) and decreased after Cu (26%; t1/2: 8.0h), whereas catalase expression was increased after Fe and decreased after Cu overloads. Glutathione peroxidase activity decreased after metal loads by 22-39% with a t1/2 of 4.5h and with unchanged protein expression. GSH is the main and fastest responder antioxidant in Fe and Cu overloads. The results indicate that thiol (SH) content and antioxidant enzyme activities are central to the antioxidant defense in the oxidative stress and damage after Fe and Cu overloads.

  20. 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

  1. 77 FR 11598 - Thermal Overload Protection for Electric Motors on Motor-Operated Valves

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-27

    ... 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 Protection... NRC's staff for complying with NRC requirements for the application of thermal overload...

  2. 46 CFR 111.15-25 - Overload and reverse current protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Overload and reverse current protection. 111.15-25... § 111.15-25 Overload and reverse current protection. (a) An overload protective device must be in each... automatically against reversal of current....

  3. 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

    2015-12-07

    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.

  4. 30 CFR 75.518 - 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... 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...

  5. 30 CFR 75.518 - 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... 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...

  6. 30 CFR 75.518 - 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... 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...

  7. 30 CFR 75.518 - 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... 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...

  8. 30 CFR 75.518 - 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... 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...

  9. 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 Central

    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

  10. 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

  11. 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.

  12. Improved arterial oxygenation with biologically variable or fractal ventilation using low tidal volumes in a porcine model of acute respiratory distress syndrome.

    PubMed

    Boker, Abdulaziz; Graham, M Ruth; Walley, Keith R; McManus, Bruce M; Girling, Linda G; Walker, Elizabeth; Lefevre, Gerald R; Mutch, W Alan C

    2002-02-15

    We compared biologically variable ventilation (V (bv); n = 9) with control mode ventilation (V (c); n = 8) at low tidal volume (VT)--initial 6 ml/kg--in a porcine model of acute respiratory distress syndrome (ARDS). Hemodynamics, respiratory gases, airway pressures, and VT data were measured. Static P-V curves were generated at 5 h. Interleukin (IL)-8 and IL-10 were measured in serum and tracheal aspirate. By 5 h, higher Pa(O(2)) (173 +/- 30 mm Hg versus 119 +/- 23 mm Hg; mean +/- SD; p < 0.0001 group x time interaction [G x T]), lower shunt fraction (6 +/- 1% versus 9 +/- 3%; p = 0.0026, G x T) at lower peak airway pressure (21 +/- 2 versus 24 +/- 1 cm H(2)O; p = 0.0342; G x T) occurred with V (bv). IL-8 concentrations in tracheal aspirate and wet:dry weight ratios were inversely related; p = 0.011. With V (c), IL-8 concentrations were 3.75-fold greater at wet:dry weight ratio of 10. IL-10 concentrations did not differ between groups. In both groups, ventilation was on the linear portion of the P-V curve. With V (bv), VT variability demonstrated an inverse power law indicating fractal behavior. In this model of ARDS, V (bv) improved Pa(O(2)) at lower peak airway pressure and IL-8 levels compared with V (c).

  13. Association Between Contrast Media Volume-Glomerular Filtration Rate Ratio and Contrast-Induced Acute Kidney Injury After Primary Percutaneous Coronary Intervention.

    PubMed

    Celik, Omer; Ozturk, Derya; Akin, Fatih; Ayca, Burak; Yalcın, Ahmet Arif; Erturk, Mehmet; Bıyık, Ismail; Ayaz, Ahmet; Akturk, Ibrahim Faruk; Enhos, Asım; Aslan, Serkan

    2015-07-01

    We hypothesized that contrast media volume-estimated glomerular filtration rate (CV-e-GFR) ratio may be a predictor of contrast media-induced acute kidney injury (CI-AKI). We investigated the associations between CV-e-GFR ratio and CI-AKI in 597 patients undergoing primary percutaneous coronary intervention (pPCI). An absolute ≥0.3 mg/dL increase in serum creatinine compared with baseline levels within 48 hours after the procedure was considered as CI-AKI; 78 (13.1%) of the 597 patients experienced CI-AKI. The amount of contrast during procedure was higher in the CI-AKI group than in those without CI-AKI (153 vs 135 mL, P = .003). The CV-e-GFR ratio was significantly higher in patients with CI-AKI than without (2.3 vs 1.5, P < .001). In multivariate analysis, independent predictors of CI-AKI were low left ventricular ejection fraction (P = .018, odds ratio [OR] = 0.966), e-GFR <60 mL/min (P = .012, OR = 2.558), and CV-e-GFR >2 (P < .001, OR = 5.917). In conclusion, CV-e-GFR ratio is significantly associated with CI-AKI after pPCI.

  14. 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.

  15. Hepcidin and Hfe in iron overload in β-thalassemia

    PubMed Central

    Gardenghi, Sara; Ramos, Pedro; Follenzi, Antonia; Rao, Niva; Rachmilewitz, Eliezer A.; Giardina, Patricia J.; Grady, Robert W.; Rivella, Stefano

    2013-01-01

    Hepcidin (HAMP) negatively regulates iron absorption, degrading the iron exporter ferroportin at the level of enterocytes and macrophages. We showed that mice with β-thalassemia intermedia (th3/+) have increased anemia and iron overload. However, their hepcidin expression is relatively low compared to their iron burden. We also showed that the iron metabolism gene Hfe is down-regulated in concert with hepcidin in th3/+ mice. These observations suggest that low hepcidin levels are responsible for abnormal iron absorption in thalassemic mice and that down-regulation of Hfe might be involved in the pathway that controls hepcidin synthesis in β-thalassemia. Therefore, these studies suggest that increasing hepcidin and/or Hfe expression could be a strategy to reduces iron overload in these animals. The goal of this paper is to review recent findings that correlate hepcidin, Hfe, and iron metabolism in β-thalassemia and to discuss potential novel therapeutic approaches based on these recent discoveries. PMID:20712796

  16. Iron Overload Cardiomyopathy, Better Understanding of An Increasing Disorder

    PubMed Central

    Gujja, Pradeep; Rosing, Douglas R.; Tripodi, Dorothy J.; Shizukuda, Yukitaka

    2010-01-01

    The prevalence of Iron Overload Cardiomyopathy (IOC) is increasing. The spectrum of symptoms of IOC is varied. Early in the disease process, patients may be asymptomatic while severely overloaded patients can have terminal heart failure complaints that are refractory to treatment. It has been shown that early recognition and intervention may alter outcomes. Biochemical markers and tissue biopsy, that have traditionally been used to diagnose and guide therapy, are not sensitive enough to detect early cardiac iron deposition. Newer diagnostic modalities such as MRI are noninvasive and can assess quantitative cardiac iron load. Phlebotomy and chelating drugs are suboptimal means of treating IOC; hence the roles of gene therapy, hepcidin, and CCBs are being actively investigated. There is a need for the development of clinical guidelines in order to improve the management of this emerging complex disease. PMID:20846597

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

    PubMed

    Doyle, Adam; Rusli, Ferry; Bhathal, Prithi

    2015-05-14

    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.

  18. Culinary plants and their potential impact on metabolic overload.

    PubMed

    Kim, Ji Yeon; Kwon, Oran

    2011-07-01

    Contemporary human behavior has led a large proportion of the population to metabolic overload and obesity. Postprandial hyperlipidemia and hyperglycemia evoke redox imbalance in the short term and lead to complex chronic disease in the long term with repeated occurrence. Complex diseases are best prevented with complex components of plants; thus, current nutrition research has begun to focus on the development of plant-based functional foods and dietary supplements for health and well-being. Furthermore, given the wide range of species, parts, and secondary metabolites, culinary plants can contribute significant variety and complexity to the human diet. Although understanding the health benefits of culinary plants has been one of the great challenges in nutritional science due to their inherent complexity, it is an advantageous pursuit. This review will address the challenges and opportunities relating to studies of the health benefits of culinary plants, with an emphasis on obesity attributed to metabolic overload.

  19. 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.

  20. 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.

  1. A novel aldosterone synthase inhibitor ameliorates mortality in pressure-overload mice with heart failure.

    PubMed

    Furuzono, Shinji; Meguro, Masaki; Miyauchi, Satoru; Inoue, Shinichi; Homma, Tsuyoshi; Yamada, Keisuke; Tagawa, Yoh-Ichi; Nara, Futoshi; Nagayama, Takahiro

    2017-01-15

    It has been elucidated that mineralocorticoid receptor antagonists reduce mortality in patients with congestive heart failure and post-acute myocardial infarction. A direct inhibition of aldosterone synthase (CYP11B2) is also expected to have therapeutic benefits equal in quality to mineralocorticoid receptor antagonists in terms of reducing mineralocorticoid receptor signaling. Therefore, we have screened our chemical libraries and identified a novel and potent aldosterone synthase inhibitor, 2,2,2-trifluoro-1-{4-[(4-fluorophenyl)amino]pyrimidin-5-y}-1-[1-(methylsulfonyl)piperidin-4-yl]ethanol (compound 1), by lead optimization. Pharmacological properties of compound 1 were examined in in vitro cell-based assays and an in vivo mouse model of pressure-overload hypertrophy by transverse aortic constriction (TAC). Compound 1 showed potent CYP11B2 inhibition against human and mouse enzymes (IC50; 0.003μM and 0.096μM, respectively) in a cell-based assay. The oral administration of 0.06% compound 1 in the food mixture of a mouse TAC model significantly reduced the plasma aldosterone level and ameliorated mortality rate. This study is the first to demonstrate that a CYP11B2 inhibitor improved survival rates of heart failure induced by pressure-overload in mice. The treatment of 0.06% compound 1 did not elevate plasma potassium level in this model, although further evaluation of hyperkalemia is needed. These results suggest that compound 1 can be developed as a promising oral CYP11B2 inhibitor for pharmaceutical applications. Compound 1 could also be a useful compound for clarifying the role of aldosterone in cardiac hypertrophy.

  2. 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

  3. Metabolic adaptation to tissue iron overload confers tolerance to malaria.

    PubMed

    Gozzelino, Raffaella; Andrade, Bruno Bezerril; Larsen, Rasmus; Luz, Nivea F; Vanoaica, Liviu; Seixas, Elsa; Coutinho, Antonio; Cardoso, Sílvia; Rebelo, Sofia; Poli, Maura; Barral-Netto, Manoel; Darshan, Deepak; Kühn, Lukas C; Soares, Miguel P

    2012-11-15

    Disease tolerance is a defense strategy that limits the fitness costs of infection irrespectively of pathogen burden. While restricting iron (Fe) availability to pathogens is perceived as a host defense strategy, the resulting tissue Fe overload can be cytotoxic and promote tissue damage to exacerbate disease severity. Examining this interplay during malaria, the disease caused by Plasmodium infection, we find that expression of the Fe sequestering protein ferritin H chain (FtH) in mice, and ferritin in humans, is associated with reduced tissue damage irrespectively of pathogen burden. FtH protection relies on its ferroxidase activity, which prevents labile Fe from sustaining proapoptotic c-Jun N-terminal kinase (JNK) activation. FtH expression is inhibited by JNK activation, promoting tissue Fe overload, tissue damage, and malaria severity. Mimicking FtH's antioxidant effect or inhibiting JNK activation pharmacologically confers therapeutic tolerance to malaria in mice. Thus, FtH provides metabolic adaptation to tissue Fe overload, conferring tolerance to malaria.

  4. 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.

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

    PubMed

    Müller-Wille, Staffan; Charmantier, Isabelle

    2012-03-01

    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.

  6. Role of renal sympathetic nerves in mediating hypoperfusion of renal cortical microcirculation in experimental congestive heart failure and acute extracellular fluid volume depletion.

    PubMed Central

    Kon, V; Yared, A; Ichikawa, I

    1985-01-01

    To evaluate the pathophysiologic importance of renal nerves in regulating the renal vasomotor tone, we measured several parameters of renal cortical microcirculation before and after acute renal denervation (DNx) in the following three groups of anesthetized Munich-Wistar rats: (group 1) congestive heart failure after surgically induced myocardial infarction (n = 10), (group 2) acute extracellular fluid volume depletion after deprivation of drinking water for 48 h (n = 8), and (group 3) sham or nontreated controls (n = 6). In the myocardial-infarcted rats, DNx led to a uniform increase in glomerular plasma flow rate of, on average, 36%. Single nephron glomerular filtration rate of myocardial-infarcted rats also increased despite a reduction in glomerular capillary hydraulic pressure. These changes were associated with a fall in arteriolar resistances, particularly in the efferent arteriole. The glomerular capillary ultrafiltration coefficient rose in all but one myocardial-infarcted animal. A similar hemodynamic pattern was seen after DNx in water-deprived animals. In every water-deprived animal, glomerular plasma flow rate and single nephron GFR increased on average by 28 and 14%, respectively. Again, afferent and efferent arteriolar resistances decreased significantly. Furthermore, the ultrafiltration coefficient increased uniformly and substantially with DNx. To ascertain the potential importance of the interaction between the renal nerves and angiotensin II in these circumstances, we compared the renal cortical hemodynamics in additional groups of water-deprived rats (group 4) after DNx (n = 15), (group 5) during inhibition of angiotensin II with saralasin (n = 15), and (group 6) during treatment with both saralasin and DNx (n = 15). No appreciable difference was detected between group 4 vs. 6. In contrast, substantial differences were noted between group 5 vs. 6: on average, the glomerular plasma flow rate was 26% higher and the afferent and efferent

  7. Dexrazoxane Shows No Protective Effect in the Acute Phase of Reperfusion during Myocardial Infarction in Pigs

    PubMed Central

    Kamat, Pranitha; Vandenberghe, Stijn; Christen, Stephan; Bongoni, Anjan K.; Meier, Bernhard; Rieben, Robert; Khattab, Ahmed A.

    2016-01-01

    Calcium and iron overload participate in the mechanisms of ischemia/reperfusion (I/R) injury during myocardial infarction (MI). Calcium overload induces cardiomyocyte death by hypercontraction, while iron catalyses generation of reactive oxygen species (ROS). We therefore hypothesized that dexrazoxane, an intracellular metal chelator, would attenuate I/R injury. MI was induced in pigs by occlusion of the left anterior descending artery for 1 hour followed by 2 hours reperfusion. Thirty minutes before reperfusion either 5 mg/ml dexrazoxane (n = 5) or saline (n = 5) was infused intravenously. Myocardial necrosis as percentage of the area at ischemic risk was found to be similar in both groups (77.2 ± 18% for dexrazoxane and 76.4 ± 14% for saline group) as determined by triphenyl tetrazolium chloride staining of the ischemic myocardium. Also, serum levels of troponin-I were similar in both groups. A conductance catheter was used to measure left ventricular pressure and volume at all times. Markers for tissue damage due to ROS (HNE), endothelial cell activation (CD31) and inflammation (IgG, C3b/c, C5b9, MCP-1) were assessed on tissue and/or in serum. No significant differences were observed between the groups for the parameters analyzed. To conclude, in this clinically relevant model of early reperfusion after acute myocardial ischemia, dexrazoxane lacked attenuating effects on I/R injury as shown by the measured parameters. PMID:28002439

  8. Iron overload patients with unknown etiology from national survey in Japan.

    PubMed

    Ikuta, Katsuya; Hatayama, Mayumi; Addo, Lynda; Toki, Yasumichi; Sasaki, Katsunori; Tatsumi, Yasuaki; Hattori, Ai; Kato, Ayako; Kato, Koichi; Hayashi, Hisao; Suzuki, Takahiro; Kobune, Masayoshi; Tsutsui, Miyuki; Gotoh, Akihiko; Aota, Yasuo; Matsuura, Motoo; Hamada, Yuzuru; Tokuda, Takahiro; Komatsu, Norio; Kohgo, Yutaka

    2017-03-01

    Transfusion is believed to be the main cause of iron overload in Japan. A nationwide survey on post-transfusional iron overload subsequently led to the establishment of guidelines for iron chelation therapy in this country. To date, however, detailed clinical information on the entire iron overload population in Japan has not been fully investigated. In the present study, we obtained and studied detailed clinical information on the iron overload patient population in Japan. Of 1109 iron overload cases, 93.1% were considered to have occurred post-transfusion. There were, however, 76 cases of iron overload of unknown origin, which suggest that many clinicians in Japan may encounter some difficulty in correctly diagnosing and treating iron overload. Further clinical data were obtained for 32 cases of iron overload of unknown origin; median of serum ferritin was 1860.5 ng/mL. As occurs in post-transfusional iron overload, liver dysfunction was found to be as high as 95.7% when serum ferritin levels exceeded 1000 ng/mL in these patients. Gene mutation analysis of the iron metabolism-related genes in 27 cases of iron overload with unknown etiology revealed mutations in the gene coding hemojuvelin, transferrin receptor 2, and ferroportin; this indicates that although rare, hereditary hemochromatosis does occur in Japan.

  9. 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

  10. Establishment of secondary iron overloaded mouse model: evaluation of cardiac function and analysis according to iron concentration.

    PubMed

    Moon, Se Na; Han, Ji Whan; Hwang, Hui Seung; Kim, Mee Jeong; Lee, Soon Ju; Lee, Jae Young; Oh, Chang Kyu; Jeong, Dae Chul

    2011-10-01

    Periodic blood transfusion can lead to secondary iron overload in patients with hematologic and oncologic diseases. Iron overload can result in iron deposition in heart tissue, which decreases cardiac function and can ultimately lead to death due to dilated cardiomyopathy and cardiac failure. In this study, we established murine model of secondary iron overload, studied the changes in cardiac function with echocardiography, and examined the histopathologic changes. Three experimental groups of the six week-old C57/BL mice (H-2(b)) were injected intraperitoneally with 10 mg of iron dextran daily 5 days a week for 2, 4, and 6 weeks. Cumulative doses of iron for the three experimental groups were 100, 200, and 300 mg, while the control groups were injected with the same amounts of phosphate-buffered saline. We studied the cardiac function under anesthesia with echocardiography using a GE Vivid7 Dimension system. Plasma iron levels and liver iron contents were measured. The hearts and livers were harvested and stained with H&E and Perls Prussian blue for iron, and the levels of iron deposit were examined. We assessed the cardiac measurements after adjustment for weight. On echocardiography, thicknesses of the interventricular septum and posterior ventricular wall (PS) during diastole showed correlation with the amount of iron deposit (P < 0.01). End-diastolic volume showed dilatation of the left ventricle in the 300 mg group (P < 0.01). Changes in the fractional shortening were not statistically significant (P = 0.07). Plasma iron levels and liver iron contents were increased proportionally according to the amount of iron loaded. The histopathologic findings of PS and liver showed higher grade of iron deposit proportional to the cumulated iron dose. In this study, we present an animal model which helps understand the cardiac function changes in patients with secondary iron overload due to repeated blood transfusions. Our results may help characterize the

  11. Transfusion-related acute lung injury: a review.

    PubMed

    Looney, Mark R; Gropper, Michael A; Matthay, Michael A

    2004-07-01

    Transfusion-related acute lung injury (TRALI) is an underreported complication of transfusion therapy, and it is the third most common cause of transfusion-associated death. TRALI is defined as noncardiogenic pulmonary edema temporally related to transfusion therapy. The diagnosis of TRALI relies on excluding other diagnoses such as sepsis, volume overload, and cardiogenic pulmonary edema. Supportive diagnostic evidence includes identifying neutrophil or human leukocyte antigen (HLA) antibodies in the donor or recipient plasma. All plasma-containing blood products have been implicated in TRALI, with the majority of cases linked to whole blood, packed RBCs, platelets, and fresh-frozen plasma. The pathogenesis of TRALI may be explained by a "two-hit" hypothesis, with the first "hit" being a predisposing inflammatory condition commonly present in the operating room or ICU. The second hit may involve the passive transfer of neutrophil or HLA antibodies from the donor or the transfusion of biologically active lipids from older, cellular blood products. Treatment is supportive, with a prognosis substantially better than most causes of clinical acute lung injury.

  12. 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

  13. 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.

  14. Mitochondrial calcium overload is a key determinant in heart failure.

    PubMed

    Santulli, Gaetano; Xie, Wenjun; Reiken, Steven R; Marks, Andrew R

    2015-09-08

    Calcium (Ca2+) released from the sarcoplasmic reticulum (SR) is crucial for excitation-contraction (E-C) coupling. Mitochondria, the major source of energy, in the form of ATP, required for cardiac contractility, are closely interconnected with the SR, and Ca2+ is essential for optimal function of these organelles. However, Ca2+ accumulation can impair mitochondrial function, leading to reduced ATP production and increased release of reactive oxygen species (ROS). Oxidative stress contributes to heart failure (HF), but whether mitochondrial Ca2+ plays a mechanistic role in HF remains unresolved. Here, we show for the first time, to our knowledge, that diastolic SR Ca2+ leak causes mitochondrial Ca2+ overload and dysfunction in a murine model of postmyocardial infarction HF. There are two forms of Ca2+ release channels on cardiac SR: type 2 ryanodine receptors (RyR2s) and type 2 inositol 1,4,5-trisphosphate receptors (IP3R2s). Using murine models harboring RyR2 mutations that either cause or inhibit SR Ca2+ leak, we found that leaky RyR2 channels result in mitochondrial Ca2+ overload, dysmorphology, and malfunction. In contrast, cardiac-specific deletion of IP3R2 had no major effect on mitochondrial fitness in HF. Moreover, genetic enhancement of mitochondrial antioxidant activity improved mitochondrial function and reduced posttranslational modifications of RyR2 macromolecular complex. Our data demonstrate that leaky RyR2, but not IP3R2, channels cause mitochondrial Ca2+ overload and dysfunction in HF.

  15. 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.

  16. 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.

  17. Therapeutic effects of udenafil on pressure-overload cardiac hypertrophy.

    PubMed

    Kim, Hack-Lyoung; Kim, Yong-Jin; Kim, Kyung-Hee; Lee, Seung-Pyo; Kim, Hyung-Kwan; Sohn, Dae-Won; Oh, Byung-Hee; Park, Young-Bae

    2015-09-01

    This study was performed to determine whether the newly developed phosphodiesterase type 5 (PDE5) inhibitor udenafil had beneficial effects on pressure-overload cardiac hypertrophy. Pressure overload cardiac hypertrophy was created by using suprarenal aortic constriction (SAC) in male Sprague-Dawley rats. Rats were divided into three groups: sham (n=19), SAC (n=18) and SAC+udenafil (n=14) groups. Three-week periods of SAC provoked significant left ventricular (LV) hypertrophy. Udenafil was administered (20 mg kg(-1) PO, daily) between the 3rd and 20th weeks after SAC in the SAC+udenafil group. Udenafil improved the survival rate (log-rank P=0.012) and exercise capacity (maximal exercise duration at the 20th week after surgery: 448±54 s for the SAC+udenafil group versus 317±73 s for the SAC group, P<0.05) of the rats with SAC. Serial echocardiographic examinations showed that udenafil attenuated LV remodeling processes following SAC (mean LV end-diastolic dimension at the 20th week after surgery: 9.84±0.59 mm for SAC and 9.05±0.58 mm for SAC+udenafil group, P<0.05). Invasive hemodynamic studies showed that udenafil improved the LV performance. Udenafil-attenuated myocardial fibrosis and apoptosis. Udenafil also decreased myocardial matrix metalloproteinase-9 expression and augmented serum interleukin-10 concentration. Long-term udenafil use prevented cardiac remodeling and improved exercise capacity and survival in rats exposed to pressure-overload cardiac hypertrophy.

  18. Inherent overload protection for the series resonant converter

    NASA Technical Reports Server (NTRS)

    King, R. J.; Stuart, T. A.

    1983-01-01

    The overload characteristics of the full bridge series resonant power converter are considered. This includes analyses of the two most common control methods presently in use. The first of these uses a current zero crossing detector to synchronize the control signals and is referred to as the alpha controller. The second is driven by a voltage controlled oscillator and is referred to as the gamma controller. It is shown that the gamma controller has certain reliability advantages in that it can be designed with inherent short circuit protection. Experimental results are included for an 86 kHz converter using power metal-oxide-semiconductor field-effect transistors (MOSFETs).

  19. [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.

  20. 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.

  1. Estrogen inhibits mast cell chymase release to prevent pressure overload-induced adverse cardiac remodeling.

    PubMed

    Li, Jianping; Jubair, Shaiban; Janicki, Joseph S

    2015-02-01

    Estrogen regulation of myocardial chymase and chymase effects on cardiac remodeling are unknown. To test the hypothesis that estrogen prevents pressure overload-induced adverse cardiac remodeling by inhibiting mast cell (MC) chymase release, transverse aortic constriction or sham surgery was performed in 7-week-old intact and ovariectomized (OVX) rats. Three days before creating the constriction, additional groups of OVX rats began receiving 17β-estradiol, a chymase inhibitor, or a MC stabilizer. Left ventricular function, cardiomyocyte size, collagen volume fraction, MC density and degranulation, and myocardial and plasma chymase levels were assessed 18 days postsurgery. Aortic constriction resulted in ventricular hypertrophy in intact and OVX groups, whereas collagen volume fraction was increased only in OVX rats. Chymase protein content was increased by aortic constriction in the intact and OVX groups, with the magnitude of the increase being greater in OVX rats. MC density and degranulation, plasma chymase levels, and myocardial active transforming growth factor-β1 levels were increased by aortic constriction only in OVX rats. Estrogen replacement markedly attenuated the constriction-increased myocardial chymase, MC density and degranulation, plasma chymase, and myocardial active transforming growth factor-β1, as well as prevented ventricular hypertrophy and increased collagen volume fraction. Chymostatin attenuated the aortic constriction-induced ventricular hypertrophy and collagen volume fraction in the OVX rats similar to that achieved by estrogen replacement. Nedocromil yielded similar effects, except for the reduction of chymase content. We conclude that the estrogen-inhibited release of MC chymase is responsible for the cardioprotection against transverse aortic constriction-induced adverse cardiac remodeling.

  2. Endogenous and exogenous female sex hormones and renal electrolyte handling: effects of an acute sodium load on plasma volume at rest.

    PubMed

    Sims, Stacy T; Rehrer, Nancy J; Bell, Melanie L; Cotter, James D

    2008-07-01

    This study was conducted to investigate effects of an acute sodium load on resting plasma volume (PV) and renal mechanisms across the menstrual cycle of endurance-trained women with natural (NAT) or oral contraceptive pill (OCP) controlled cycles. Twelve women were assigned to one of two groups, according to their usage status: 1) OCP [n = 6, 29 yr (SD 6), 59.4 kg (SD 3.2)], or 2) NAT [n = 6, 24 yr (SD 5), 61.3 kg (SD 3.6)]. The sodium load was administered as a concentrated sodium chloride/citrate beverage (164 mmol Na(+)/l, 253 mosmol/kgH(2)O, 10 ml/kg body mass) during the last high-hormone week of the OCP cycle (OCP(high)) or late luteal phase of the NAT cycle (NAT(high)) and during the low-hormone sugar pill week of OCP (OCP(low)) or early follicular phase of the NAT cycle (NAT(low)). The beverage ( approximately 628 ml) was ingested in seven portions across 60 min. Over the next 4 h, PV expanded more in the low-hormone phase for both groups (time-averaged change): OCP(low) 6.1% (SD 1.1) and NAT(low) 5.4% (SD 1.2) vs. OCP(high) 3.9% (SD 0.9) and NAT(high) 3.5% (SD 0.8) (P = 0.02). The arginine vasopressin increased less in the low-hormone phase [1.63 (SD 0.2) and 1.30 pg/ml (SD 0.2) vs. 1.82 (SD 0.3) and 1.57 pg/ml (SD 0.5), P = 0.0001], as did plasma aldosterone concentration ( approximately 64% lower, P = 0.0001). Thus PV increased more and renal hormone sensitivity was decreased in the low-hormone menstrual phase following sodium/fluid ingestion, irrespective of OCP usage.

  3. Nutritional deficiencies in iron overloaded patients with hemoglobinopathies.

    PubMed

    Claster, Susan; Wood, John C; Noetzli, Leila; Carson, Susan M; Hofstra, Thomas C; Khanna, Rachna; Coates, Thomas D

    2009-06-01

    One of the hallmarks of both sickle cell disease (SCD) and thalassemia major (TM) is accelerated oxidative damage. Decreased antioxidant levels and increased oxidant stress biomarkers are found in both diseases. Although isolated vitamin deficiencies have been reported in TM and nontransfused SCD patients, a comprehensive evaluation of vitamin and trace mineral levels has never been performed in chronically transfused SCD or TM patients. As vitamins and trace minerals may be consumed as a result of chronic oxidative stress; we hypothesized that levels of these compounds would correlate with surrogates of iron overload, hemolysis, and inflammation in chronically transfused patients. Using a convenience sample of our group of chronically transfused patients we studied 43 patients with SCD (17 male, 26 female) and 24 patients with TM (13 male and 11 female). The age range for our patients varied from 1.5 to 31.4 years. Levels of vitamins A, thiamin, B6, B12, C, D, E as well as selenium, zinc, copper, and ceruloplasmin were measured. We found that 40-75% of the patients were deficient in A, C, D and selenium and 28-38% of the patients had low levels of B vitamins and folate. There was little association with iron overload, hemolysis, or inflammation. Although the precise mechanism of these deficiencies is unclear, they may contribute to the morbidity of chronically transfused hemoglobinopathy patients.

  4. 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.

  5. Bezafibrate Attenuates Pressure Overload-Induced Cardiac Hypertrophy and Fibrosis

    PubMed Central

    Xu, Si-Chi; Ma, Zhen-Guo; Wei, Wen-Ying; Yuan, Yu-Pei

    2017-01-01

    Background. Peroxisome proliferator-activated receptor-α (PPAR-α) is closely associated with the development of cardiac hypertrophy. Previous studies have indicated that bezafibrate (BZA), a PPAR-α agonist, could attenuate insulin resistance and obesity. This study was designed to determine whether BZA could protect against pressure overload-induced cardiac hypertrophy. Methods. Mice were orally given BZA (100 mg/kg) for 7 weeks beginning 1 week after aortic banding (AB) surgery. Cardiac hypertrophy was assessed based on echocardiographic, histological, and molecular aspects. Moreover, neonatal rat ventricular cardiomyocytes (NRVMs) were used to investigate the effects of BZA on the cardiomyocyte hypertrophic response in vitro. Results. Our study demonstrated that BZA could alleviate cardiac hypertrophy and fibrosis in mice subjected to AB surgery. BZA treatment also reduced the phosphorylation of protein kinase B (AKT)/glycogen synthase kinase-3β (GSK3β) and mitogen-activated protein kinases (MAPKs). BZA suppressed phenylephrine- (PE-) induced hypertrophy of cardiomyocyte in vitro. The protective effects of BZA were abolished by the treatment of the PPAR-α antagonist in vitro. Conclusions. BZA could attenuate pressure overload-induced cardiac hypertrophy and fibrosis. PMID:28127304

  6. Overloaded training increases exercise-induced oxidative stress and damage.

    PubMed

    Palazzetti, Stephane; Richard, Marie-Jeanne; Favier, Alain; Margaritis, Irene

    2003-08-01

    We hypothesized that overloaded training (OT) in triathlon would induce oxidative stress and damage on muscle and DNA. Nine male triathletes and 6 male sedentary subjects participated in this study. Before and after a 4-week OT, triathletes exercised for a duathlon. Blood ratio of reduced vs. oxidized glutathione (GSH/GSSG), plasma thiobarbituric acid reactive substances (TBARS), leukocyte DNA damage, creatine kinase (CK), and CK-MB mass in plasma, erythrocyte superoxide dismutase (SOD) activity, erythrocyte and plasma glutathione peroxidase (GSH-Px) activities, and plasma total antioxidant status (TAS) were measured before and after OT in pre- and postexercise situations. Triathletes were overloaded in response to OT. In rest conditions, OT induced plasma GSH-Px activity increase and plasma TAS decrease (both p < 0.05). In exercise conditions, OT resulted in higher exercise-induced variations of blood GSH/GSSG ratio, TBARS level (both p < 0.05), and CK-MB mass (p < 0.01) in plasma; and decreased TAS response (p < 0.05). OT could compromise the antioxidant defense mechanism with respect to exercise-induced response. The resulting increased exercise-induced oxidative stress and further cellular susceptibility to damage needs more study.

  7. Electrochemical sensor for predicting transformer overload by phenol measurement.

    PubMed

    Bosworth, Timothy; Setford, Steven; Heywood, Richard; Saini, Selwayan

    2003-03-10

    Transformer overload is a significant problem to the power transmission industry, with severe safety and cost implications. Overload may be predicted by measuring phenol levels in the transformer-insulating oil, arising from the thermolytic degradation of phenol-formaldehyde resins. The development of two polyphenol oxidase (PPO) sensors, based on monitoring the enzymatic consumption of oxygen using an oxygen electrode, or reduction of enzymatically generated o-quinone at a screen-printed electrode (SPE), for the measurement of phenol in transformer oil is reported. Ex-service oils were prepared either by extraction into aqueous electrolyte-buffer, or by direct dilution in propan-2-ol, the latter method being more amenable to simple at-line operation. The oxygen electrode, with a sensitivity of 2.87 nA microg(-1) ml(-1), RSD of 7.0-19.9% and accuracy of +/-8.3% versus the industry standard International Electrotechnical Commission (IEC) method, proved superior to the SPE (sensitivity: 3.02 nA microg(-1) ml(-1); RSD: 8.9-18.3%; accuracy: +/-7.9%) and was considerably more accurate at low phenol concentrations. However, the SPE approach is more amenable to field-based usage for reasons of device simplicity. The method has potential as a rapid and simple screening tool for the at-site monitoring of phenol in transformer oils, thereby reducing incidences of transformer failure.

  8. 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.

  9. Information overload within the health care system: a literature review.

    PubMed

    Hall, Amanda; Walton, Graham

    2004-06-01

    There is a widespread view held by health clinicians that their work effectiveness is impaired by 'information overload.' Building upon a previous work by Wilson, a review of the literature was undertaken to look for the evidence of this. It was found that the literature, particularly in the context of the clinical environment, was limited. This review explores the diverse overarching theories of information overload, effects of the phenomenon that are perceived to occur and proposed solutions to this problem. Many of the papers noted an information explosion but only three authors explicitly attempted to measure both the quantity and the complexity of this information. It was also found that the typology of the information studied was severely limited with most studies exploring information such as guidelines, access to journals, research findings and other knowledge intensive areas. Solutions proposed seem to concentrate on technological means rather than exploring the use of humans either in management of information or as a step in the filtering process.

  10. Myocardial iron overload in thalassaemia major. How early to check?

    PubMed

    Borgna-Pignatti, Caterina; Meloni, Antonella; Guerrini, Giulia; Gulino, Letizia; Filosa, Aldo; Ruffo, Giovan B; Casini, Tommaso; Chiodi, Elisabetta; Lombardi, Massimo; Pepe, Alessia

    2014-02-01

    The age at which it is necessary to start Cardiovascular Magnetic Resonance (CMR) T2* screening in thalassaemia major (TM) is still uncertain. To clarify this point, we evaluated the prevalence of myocardial iron overload (MIO), function and fibrosis by CMR in TM patients younger than 10 years. We retrospectively selected 35 TM patients enrolled in the Myocardial Iron Overload in Thalassaemia network. MIO was measured by T2* multislice multiecho technique. Biventricular function parameters were evaluated by cine images. To detect myocardial fibrosis, late gadolinium enhancement images were acquired. Patients' age ranged from 4·2 to 9·7 years. All scans were performed without sedation. Nine patients showed no MIO, 22 patients had heterogeneous MIO with a T2* global value ≥20 ms; two patients had heterogeneous MIO with a T2* global value <20 ms and two patients showed homogeneous MIO. No patient showed myocardial fibrosis. Among the patients with heart T2*<20 ms, the youngest was 6 years old, none showed heart dysfunction and the iron transfused was <35 g in all cases. Cardiac iron loading can occur much earlier than previously described. The first cardiac T2* assessment should be performed as early as feasible without sedation, especially if chelation is started late or if poor compliance is suspected.

  11. 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.

  12. Iron overload signature in chrysotile-induced malignant mesothelioma.

    PubMed

    Jiang, Li; Akatsuka, Shinya; Nagai, Hirotaka; Chew, Shan-Hwu; Ohara, Hiroki; Okazaki, Yasumasa; Yamashita, Yoriko; Yoshikawa, Yutaka; Yasui, Hiroyuki; Ikuta, Katsuya; Sasaki, Katsunori; Kohgo, Yutaka; Hirano, Seishiro; Shinohara, Yasushi; Kohyama, Norihiko; Takahashi, Takashi; Toyokuni, Shinya

    2012-11-01

    Exposure to asbestos is a risk for malignant mesothelioma (MM) in humans. Among the commercially used types of asbestos (chrysotile, crocidolite, and amosite), the carcinogenicity of chrysotile is not fully appreciated. Here, we show that all three asbestos types similarly induced MM in the rat peritoneal cavity and that chrysotile caused the earliest mesothelioma development with a high fraction of sarcomatoid histology. The pathogenesis of chrysotile-induced mesothelial carcinogenesis was closely associated with iron overload: repeated administration of an iron chelator, nitrilotriacetic acid, which promotes the Fenton reaction, significantly reduced the period required for carcinogenesis; massive iron deposition was found in the peritoneal organs with high serum ferritin; and homozygous deletion of the CDKN2A/2B/ARF tumour suppressor genes, the most frequent genomic alteration in human MM and in iron-induced rodent carcinogenesis, was observed in 92.6% of the cases studied with array-based comparative genomic hybridization. The induced rat MM cells revealed high expression of mesoderm-specific transcription factors, Dlx5 and Hand1, and showed an iron regulatory profile of active iron uptake and utilization. These data indicate that chrysotile is a strong carcinogen when exposed to mesothelia, acting through the induction of local iron overload. Therefore, an intervention to remove local excess iron might be a strategy to prevent MM after asbestos exposure.

  13. 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.

  14. Post-transfusional iron overload in the haemoglobinopathies.

    PubMed

    Thuret, Isabelle

    2013-03-01

    In this report, we review the recent advances in evaluation and treatment of transfusional iron overload (IO). Results of the French thalassaemia registry are described. According to the disease, thalassaemia major or sickle cell anaemia, mechanisms and toxicity of iron overload, knowledge about IO long-term outcome and chelation treatment results, respective value of IO markers, differ. The recent tools evaluating organ specific IO and the diversification of iron chelator agents make possible to individualize chelation therapy in clinical practice. The severity of IO and the level of transfusional iron intake, the preferential localization of IO (heart/liver) as well as the tolerance and adherence profiles of the patient can now be taken into account. Introduction of cardiac magnetic resonance imaging for the quantification of myocardial iron and use of oral chelators have already been reported as decreasing the cardiac mortality rate related to IO in thalassaemia major patients. Long-term observation of patients under oral chelators will show if morbidity is also improving via a more continuous control of toxic iron and/or a better accessibility to cellular iron pools.

  15. 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.

  16. Pyridoxine responsive hereditary sideroblastic erythropoiesis and iron overload: two microcytic subpopulations in the affected male, one normocytic and one microcytic subpopulation in the obligate female carrier.

    PubMed

    Harris, J W; Danish, E H; Brittenham, G M; McLaren, C E

    1993-04-01

    Mild hepatic iron overload has been demonstrated by magnetic susceptibility measurements in a 22-year-old man with hereditary sideroblastic erythropoiesis despite hemoglobin levels in the normal range and a normal erythropoietin level. His grandfather's sideroblastic anemia has been found to be responsive to pyridoxine; his mother's hemoglobin has persisted in the normal range but red cell volume distribution analysis demonstrated two subpopulations; 30% with estimated geometric mean of 68 fl and 70% an estimated mean of 93 fl. Red cell distribution analysis of the grandson demonstrated two microcytic subpopulations; 46% with an estimated geometric mean of 45 fl and 54% an estimated mean of 70 fl. A therapeutic regimen is outlined to reduce to normal his iron stores and to prevent the future development of excessive iron overload.

  17. 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.

  18. Non-invasive MRI biomarkers for the early assessment of iron overload in a humanized mouse model of β-thalassemia

    PubMed Central

    Jackson, Laurence H.; Vlachodimitropoulou, Evangelia; Shangaris, Panicos; Roberts, Thomas A.; Ryan, Thomas M.; Campbell-Washburn, Adrienne E.; David, Anna L.; Porter, John B.; Lythgoe, Mark F.; Stuckey, Daniel J.

    2017-01-01

    β-thalassemia (βT) is a genetic blood disorder causing profound and life threatening anemia. Current clinical management of βT is a lifelong dependence on regular blood transfusions, a consequence of which is systemic iron overload leading to acute heart failure. Recent developments in gene and chelation therapy give hope of better prognosis for patients, but successful translation to clinical practice is hindered by the lack of thorough preclinical testing using representative animal models and clinically relevant quantitative biomarkers. Here we demonstrate a quantitative and non-invasive preclinical Magnetic Resonance Imaging (MRI) platform for the assessment of βT in the γβ0/γβA humanized mouse model of βT. Changes in the quantitative MRI relaxation times as well as severe splenomegaly were observed in the heart, liver and spleen in βT. These data showed high sensitivity to iron overload and a strong relationship between quantitative MRI relaxation times and hepatic iron content. Importantly these changes preceded the onset of iron overload cardiomyopathy, providing an early biomarker of disease progression. This work demonstrates that multiparametric MRI is a powerful tool for the assessment of preclinical βT, providing sensitive and quantitative monitoring of tissue iron sequestration and cardiac dysfunction- parameters essential for the preclinical development of new therapeutics. PMID:28240317

  19. "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)…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. 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.…

  5. 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...

  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. 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…

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

    PubMed

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

    2016-01-12

    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.

  9. 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

  10. Dietary Supplementation with ω-3 PUFA Increases Adiponectin and Attenuates Ventricular Remodeling and Dysfunction with Pressure Overload

    PubMed Central

    Duda, Monika K.; O'Shea, Karen M.; Lei, Biao; Barrows, Brian R.; Azimzadeh, Agnes M.; McElfresh, Tracy E.; Hoit, Brian D.; Kop, Willem J.; Stanley, William C.

    2009-01-01

    Objective Epidemiological studies suggest that consumption of ω-3 polyunsaturated fatty acids (ω-3 PUFA) decreases the risk of heart failure. We assessed the effects of dietary supplementation with ω-3 PUFA from fish oil on the response of the left ventricle (LV) to arterial pressure overload. Methods Male Wistar rats were fed a standard chow or a ω-3 PUFA-supplemented diet. After 1 week rats underwent abdominal aortic banding or sham surgery (n=9-12/group). LV function was assessed by echocardiography after 8 weeks. In addition, we studied the effect of ω-3 PUFA on the cardioprotective adipocyte-derived hormone adiponectin, which may alter the pro-growth serine-threonine kinase Akt. Results Banding increased LV mass to a greater extent with the standard chow (31%) than with ω-3 PUFA (18%). LV end diastolic and systolic volumes were increased by 19% and 105% with standard chow, respectively, but were unchanged with ω-3 PUFA. The expression of adiponectin was up-regulated in adipose tissue, and the plasma adiponectin concentration was significantly elevated. Treatment with ω-3 PUFA increased total Akt protein expression in the heart, but decreased the fraction of Akt in the active phosphorylated form, and thus did not alter the amount of active phospho-Akt. Conclusion Dietary supplementation with ω-3 PUFA attenuated pressure overload-induced LV dysfunction, which was associated with elevated plasma adiponectin. PMID:17643403

  11. Impaired Adaptive Response to Mechanical Overloading in Dystrophic Skeletal Muscle

    PubMed Central

    Joanne, Pierre; Hourdé, Christophe; Ochala, Julien; Caudéran, Yvain; Medja, Fadia; Vignaud, Alban; Mouisel, Etienne; Hadj-Said, Wahiba; Arandel, Ludovic; Garcia, Luis; Goyenvalle, Aurélie; Mounier, Rémi; Zibroba, Daria; Sakamato, Kei; Butler-Browne, Gillian; Agbulut, Onnik; Ferry, Arnaud

    2012-01-01

    Dystrophin contributes to force transmission and has a protein-scaffolding role for a variety of signaling complexes in skeletal muscle. In the present study, we tested the hypothesis that the muscle adaptive response following mechanical overloading (ML) would be decreased in MDX dystrophic muscle lacking dystrophin. We found that the gains in muscle maximal force production and fatigue resistance in response to ML were both reduced in MDX mice as compared to healthy mice. MDX muscle also exhibited decreased cellular and molecular muscle remodeling (hypertrophy and promotion of slower/oxidative fiber type) in response to ML, and altered intracellular signalings involved in muscle growth and maintenance (mTOR, myostatin, follistatin, AMPKα1, REDD1, atrogin-1, Bnip3). Moreover, dystrophin rescue via exon skipping restored the adaptive response to ML. Therefore our results demonstrate that the adaptive response in response to ML is impaired in dystrophic MDX muscle, most likely because of the dystrophin crucial role. PMID:22511986

  12. 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

  13. 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

  14. In vivo Evaluation of Physiological Control Algorithms for LVADs based on Left Ventricular Volume or Pressure.

    PubMed

    Ochsner, Gregor; Wilhelm, Markus J; Amacher, Raffael; Petrou, Anastasios; Cesarovic, Nikola; Staufert, Silvan; Röhrnbauer, Barbara; Maisano, Francesco; Hierold, Christofer; Meboldt, Mirko; Daners, Marianne Schmid

    2017-02-21

    Turbodynamic left ventricular assist devices (LVADs) provide a continuous flow depending on the speed at which the pump is set, and do not adapt to the changing requirements of the patient. The limited adaptation of the pump flow to the amount of venous return can lead to ventricular suction or overload. Physiological control may compensate such situations by an automatic adaptation of the pump flow to the volume status of the left ventricle. We evaluated two physiological control algorithms in an acute study with eight healthy pigs. Both controllers imitate the Frank-Starling law of the heart and are based on a measurement of the left ventricular volume or pressure, respectively. After implantation of a modified Deltastream DP2 blood pump as an LVAD, we tested the responses of the physiological controllers to hemodynamic changes and compared them with the response of the constant speed mode. Both physiological controllers adapted the pump speed such that the flow was more sensitive to preload and less sensitive to afterload, as compared to the constant speed mode. As a result, the risk for suction was strongly reduced. Five suction events were observed in the constant speed mode, one with the volume-based controller, and none with the pressure-based controller. The results suggest that both physiological controllers have the potential to reduce the number of adverse events when used in the clinical setting.

  15. Swimming and cycling overloaded training in triathlon has no effect on running kinematics and economy.

    PubMed

    Palazzetti, S; Margaritis, I; Guezennec, C Y

    2005-04-01

    The aim of the study was to verify whether an overloaded training (OT) in triathlon deteriorates running kinematics (RK) and running economy (RE). Thirteen well-trained male long-distance triathletes (age: 28.1 +/- 4.3 yrs; V.O (2max): 65.0 +/- 3.1 ml O (2) . min (-1) . kg (-1)) were divided into two groups: completed an individualized OT program (OG; n = 7) or maintained a normal level of training (NT) (CG; n = 6) for a duration of 3 weeks. Every week, each triathlete completed a standardized questionnaire to quantify the influence of training loads on mood state. To reach OT, total training load (h . 3 wk (-1)) was increased by 24 %; swimming and cycling total volumes were increased by 46 and 57 %, respectively, but the distance run was not modified in order to limit the risk of injuries. RK and RE were determined on treadmill test at 12 km . h (-1) before and after the 3 weeks. The 3-week swimming and cycling OT in triathlon was sufficiently stressful to alter mood state but not to deteriorate the running kinematics and economy parameters in our previously well-trained male long-distance triathletes.

  16. 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.

  17. Mutation analysis of the transferrin receptor-2 gene in patients with iron overload.

    PubMed

    Lee, P L; Halloran, C; West, C; Beutler, E

    2001-01-01

    Three mutations in the transferrin receptor-2 gene have recently been identified in four Sicilian families with iron overload who had a normal hemochromatosis gene, HFE (C. Camaschella, personal communication). To determine the extent to which mutations in the transferrin receptor-2 gene occur in other populations with iron overload, we have completely sequenced this gene in 17 whites, 10 Asians, and 8 African Americans with iron overload and a C282C/C282C HFE genotype, as well as 4 subjects without iron overload and homozygous for the mutant HFE C282Y genotype, 5 patients with iron overload and homozygous for the mutant HFE C282Y genotype, and 5 normal individuals. None of the individuals exhibited the Sicilian mutations, Y250X in exon 6, M172K in exon 4, and E60X in exon 2. One iron-overloaded individual of Asian descent exhibited a I238M mutation which was subsequently found to be a polymorphism present in the Asian population at a frequency of 0.0192. The presence of the I238M mutation was not associated with an increase in ferritin or transferrin saturation levels. Three silent polymorphisms were also identified, nt 1770 (D590D) and nt 1851 (A617A) and a polymorphism at nt 2255 in the 3' UTR. Thus, mutations in the transferrin receptor-2 gene were not responsible for the iron overload seen in our subjects.

  18. 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.

  19. 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.

  20. Heat shock transcription factor 1-deficiency attenuates overloading-associated hypertrophy of mouse soleus muscle.

    PubMed

    Koya, Tomoyuki; Nishizawa, Sono; Ohno, Yoshitaka; Goto, Ayumi; Ikuta, Akihiro; Suzuki, Miho; Ohira, Tomotaka; Egawa, Tatsuro; Nakai, Akira; Sugiura, Takao; Ohira, Yoshinobu; Yoshioka, Toshitada; Beppu, Moroe; Goto, Katsumasa

    2013-01-01

    Hypertrophic stimuli, such as mechanical stress and overloading, induce stress response, which is mediated by heat shock transcription factor 1 (HSF1), and up-regulate heat shock proteins (HSPs) in mammalian skeletal muscles. Therefore, HSF1-associated stress response may play a key role in loading-associated skeletal muscle hypertrophy. The purpose of this study was to investigate the effects of HSF1-deficiency on skeletal muscle hypertrophy caused by overloading. Functional overloading on the left soleus was performed by cutting the distal tendons of gastrocnemius and plantaris muscles for 4 weeks. The right muscle served as the control. Soleus muscles from both hindlimbs were dissected 2 and 4 weeks after the operation. Hypertrophy of soleus muscle in HSF1-null mice was partially inhibited, compared with that in wild-type (C57BL/6J) mice. Absence of HSF1 partially attenuated the increase of muscle wet weight and fiber cross-sectional area of overloaded soleus muscle. Population of Pax7-positive muscle satellite cells in HSF1-null mice was significantly less than that in wild-type mice following 2 weeks of overloading (p<0.05). Significant up-regulations of interleukin (IL)-1β and tumor necrosis factor mRNAs were observed in HSF1-null, but not in wild-type, mice following 2 weeks of overloading. Overloading-related increases of IL-6 and AFT3 mRNA expressions seen after 2 weeks of overloading tended to decrease after 4 weeks in both types of mice. In HSF1-null mice, however, the significant overloading-related increase in the expression of IL-6, not ATF3, mRNA was noted even at 4th week. Inhibition of muscle hypertrophy might be attributed to the greater and prolonged enhancement of IL-6 expression. HSF1 and/or HSF1-mediated stress response may, in part, play a key role in loading-induced skeletal muscle hypertrophy.

  1. Long-term efficacy of deferasirox in preventing cardiovascular complications in the iron-overloaded gerbil.

    PubMed

    Al-Rousan, Rabaa M; Manzoor, Kamran; Paturi, Satyanarayana; Arvapalli, Ravi Kumar; Laurino, Joseph P; Darnon, Lucy; Walker, Ernest M; Blough, Eric R

    2012-03-01

    Iron-induced cardiovascular disease is the leading cause of death in iron-overloaded patients. Deferasirox is a novel tridentate oral chelator that exhibits a half-life suitable for once-daily dosing; however, little is known regarding the effectiveness of this agent in preventing iron-induced cardiovascular disease. Adult male Mongolian gerbils were randomly divided into 3 groups: control, iron overload, and iron overload followed by deferasirox treatment. Iron-overloaded animals received iron dextran 100 mg/kg intraperitoneally (ip)/5 days for 10 weeks, while deferasirox was given 100 mg/kg per d orally (po) for 9 months post iron loading. Cardiac and aortic iron levels were determined by inductively coupled plasma atomic emission spectrometry. Gerbil electro- and echocardiograms were obtained in anesthetized animals at regular intervals. Compared to control animals, iron concentration was 3.3- and 2.4-fold higher in iron-overloaded heart and aorta, respectively (P < .05). Deferasirox treatment reduced cardiac and aortic iron levels by 32% and 35%, respectively (P < .05). These results were consistent with the decrease in cellular iron deposition observed with Prussian Blue iron staining. Iron-overloaded gerbils were found to exhibit frequent arrhythmias including premature ventricular contractions, supraventricular tachycardia, and recurrent ventricular tachycardia. In addition, echocardiographic assessment demonstrated iron overload-associated increase in left ventricular dimensions including left ventricular posterior wall dimension (LVPWd: 49%), left ventricular internal dimension (LVIDd: 26%), and left ventricular septum thickness (LVSd: 42%). These parameters were significantly reduced with deferasirox treatment (LVPWd: 23%, LVIDd: 24%, and LVSd: 27%). Iron overload was also associated with reduced ejection fraction (EF: by 30%) and fractional shortening (FS: by 23%) in comparison with controls (P < .05). With deferasirox treatment, these values were higher

  2. Fish oil, but not flaxseed oil, decreases inflammation and prevents pressure overload-induced cardiac dysfunction

    PubMed Central

    Duda, Monika K.; O'Shea, Karen M.; Tintinu, Anselm; Xu, Wenhong; Khairallah, Ramzi J.; Barrows, Brian R.; Chess, David J.; Azimzadeh, Agnes M.; Harris, William S.; Sharov, Victor G.; Sabbah, Hani N.; Stanley, William C.

    2009-01-01

    Aims Clinical studies suggest that intake of ω-3 polyunsaturated fatty acids (ω-3 PUFA) may lower the incidence of heart failure. Dietary supplementation with ω-3 PUFA exerts metabolic and anti-inflammatory effects that could prevent left ventricle (LV) pathology; however, it is unclear whether these effects occur at clinically relevant doses and whether there are differences between ω-3 PUFA from fish [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and vegetable sources [α-linolenic acid (ALA)]. Methods and results We assessed the development of LV remodelling and pathology in rats subjected to aortic banding treated with ω-3 PUFA over a dose range that spanned the intake of humans taking ω-3 PUFA supplements. Rats were fed a standard food or diets supplemented with EPA+DHA or ALA at 0.7, 2.3, or 7% of energy intake. Without supplementation, aortic banding increased LV mass and end-systolic and -diastolic volumes. ALA supplementation had little effect on LV remodelling and dysfunction. In contrast, EPA+DHA dose-dependently increased EPA and DHA, decreased arachidonic acid in cardiac membrane phospholipids, and prevented the increase in LV end-diastolic and -systolic volumes. EPA+DHA resulted in a dose-dependent increase in the anti-inflammatory adipokine adiponectin, and there was a strong correlation between the prevention of LV chamber enlargement and plasma levels of adiponectin (r = −0.78). Supplementation with EPA+DHA had anti-aggregatory and anti-inflammatory effects as evidenced by decreases in urinary thromboxane B2 and serum tumour necrosis factor-α. Conclusion Dietary supplementation with ω-3 PUFA derived from fish, but not from vegetable sources, increased plasma adiponectin, suppressed inflammation, and prevented cardiac remodelling and dysfunction under pressure overload conditions. PMID:19015135

  3. Weaving hypothesis of cardiomyocyte sarcomeres: discovery of periodic broadening and narrowing of intercalated disk during volume-load change.

    PubMed

    Yoshida, Makoto; Sho, Eiketsu; Nanjo, Hiroshi; Takahashi, Masato; Kobayashi, Mikio; Kawamura, Kouiti; Honma, Makiko; Komatsu, Masayo; Sugita, Akihiro; Yamauchi, Misa; Hosoi, Takahiro; Ito, Yukinobu; Masuda, Hirotake

    2010-02-01

    To investigate how cardiomyocytes change their length, echocardiographic and morphological studies were performed on rabbit hearts that were subjected to volume overload, overload removal, and repeated cycles of overload and overload removal. These conditions were created by arterio-venous fistula between the carotid artery and jugular vein, closure of the fistula, and cycles of repeatedly forming and closing fistula, respectively. After overload, hearts dilated and myocytes elongated. Intercalated disks repeatedly broadened and narrowed with a 2-day cycle, which continued for 8 weeks in many animals. The cycle consisted of shifts between five modes characterized by two interdigitation elongation-and-shortenings as follows: (I) flat with short ( approximately 1/4 to approximately 1/3 sarcomere long) interdigitations; (II) flat with long (one sarcomere long) interdigitations; (III) grooved with short interdigitations; (IV) grooved with long interdigitations; (V) flat with short interdigitations intermingled by sporadic long interdigitations; and return to (I). After overload removal, hearts contracted and myocytes shortened with similar 2-day broadening and narrowing cycle of intercalated disks, in which the five modes were reversed. Repeated overload and overload removal resulted in the repetition of myocyte elongation and shortening. We hypothesize that a single elongation-and-shortening event creates or disposes one sarcomere layer, and the two consecutive elongation-and-shortenings occur complementarily to each other so that the disks return to their original state after each cycle. Our hypothesis predicts that intercalated disks weave and unravel one sarcomere per myocyte per day.

  4. 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

  5. Synchrotron Based X-Ray Strain Mapping in Fatigued Materials Subjected to Overload

    DTIC Science & Technology

    2007-01-01

    authors [1-2]. The technique exploits the high intensity/energy white beam (30-200 KeV) x-rays of the X17 wiggler beamline at the Brookhaven National...overload aoL=25. 4 embedded overload, experiments addressed in mm and the curve has been normalized to the pre-overload this report. The red arrows...in the figure are the most deeply depressed and the red regions are the highest. Moreover, the 3-D perspective is also used in the display of the

  6. Cardiomyocyte-restricted inhibition of G protein-coupled receptor kinase-3 attenuates cardiac dysfunction after chronic pressure overload.

    PubMed

    von Lueder, Thomas G; Gravning, Jørgen; How, Ole-Jakob; Vinge, Leif E; Ahmed, Mohammed Shakil; Krobert, Kurt A; Levy, Finn Olav; Larsen, Terje S; Smiseth, Otto A; Aasum, Ellen; Attramadal, Håvard

    2012-07-01

    Transgenic mice with cardiac-specific expression of a peptide inhibitor of G protein-coupled receptor kinase (GRK)3 [transgenic COOH-terminal GRK3 (GRK3ct) mice] display myocardial hypercontractility without hypertrophy and enhanced α(1)-adrenergic receptor signaling. A role for GRK3 in the pathogenesis of heart failure (HF) has not been investigated, but inhibition of its isozyme, GRK2, has been beneficial in several HF models. Here, we tested whether inhibition of GRK3 modulated evolving cardiac hypertrophy and dysfunction after pressure overload. Weight-matched male GRK3ct transgenic and nontransgenic littermate control (NLC) mice subjected to chronic pressure overload by abdominal aortic banding (AB) were compared with sham-operated (SH) mice. At 6 wk after AB, a significant increase of cardiac mass consistent with induction of hypertrophy was found, but no differences between GRK3ct-AB and NLC-AB mice were discerned. Simultaneous left ventricular (LV) pressure-volume analysis of electrically paced, ex vivo perfused working hearts revealed substantially reduced systolic and diastolic function in NLC-AB mice (n = 7), which was completely preserved in GRK3ct-AB mice (n = 7). An additional cohort was subjected to in vivo cardiac catheterization and LV pressure-volume analysis at 12 wk after AB. NLC-AB mice (n = 11) displayed elevated end-diastolic pressure (8.5 ± 3.1 vs. 2.9 ± 1.2 mmHg, P < 0.05), reduced cardiac output (3,448 ± 323 vs. 4,488 ± 342 μl/min, P < 0.05), and reduced dP/dt(max) and dP/dt(min) (both P < 0.05) compared with GRK3ct-AB mice (n = 16), corroborating the preserved cardiac structure and function observed in GRK3ct-AB hearts assessed ex vivo. Increased cardiac mass and myocardial mRNA expression of β-myosin heavy chain confirmed the similar induction of cardiac hypertrophy in both AB groups, but only NLC-AB hearts displayed significantly elevated mRNA levels of brain natriuretic peptide and myocardial collagen contents as well as reduced

  7. Effects of acute dietary iron overload in pigs (Sus scrofa) with induced type 2 diabetes mellitus.

    PubMed

    Espinoza, A; Morales, S; Arredondo, M

    2014-06-01

    Epidemiological studies have reported an association between high iron (Fe) levels and elevated risk of developing type 2 diabetes mellitus (T2D). It is believed that the formation of Fe-catalyzed hydroxyl radicals may contribute to the development of diabetes. Our goal was to determine the effect of a diet with a high Fe content on type 2 diabetic pigs. Four groups of piglets were studied: (1) control group, basal diet; (2) Fe group, basal diet with 3,000 ppm ferrous sulfate; (3) diabetic group (streptozotocin-induced type 2 diabetes) with basal diet; (4) diabetic/Fe group, diabetic animals/3,000 ppm ferrous sulfate. For 2 months, biochemical and hematological parameters were evaluated. Tissue samples of liver and duodenum were obtained to determine mRNA relative abundance of DMT1, ferroportin (Fpn), ferritin (Fn), hepcidin (Hpc), and transferrin receptor by qRT-PCR. Fe group presented increased levels of hematological (erythrocytes, hematocrit, and hemoglobin) and iron parameters. Diabetic/Fe group showed similar behavior as Fe group but in lesser extent. The relative abundance of different genes in the four study groups yielded a different expression pattern. DMT1 showed a lower expression in the two iron groups compared with control and diabetic animals, and Hpc showed an increased on its expression in Fe and diabetic/Fe groups. Diabetic/Fe group presents greater expression of Fn and Fpn. These results suggest that there is an interaction between Fe nutrition, inflammation, and oxidative stress in the diabetes development.

  8. 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.

  9. 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

  10. 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.

  11. Constitutive modeling of human saphenous veins at overloading pressures.

    PubMed

    Veselý, J; Horný, L; Chlup, H; Adámek, T; Krajíček, M; Žitný, R

    2015-05-01

    In the present study, inflation tests with free axial extension of 15 human vena saphena magna were conducted ex vivo to obtain data suitable for multi-axial constitutive modeling at overloading conditions (pressures up to approximately 15kPa). Subsequently the data were fitted with a hyperelastic, nonlinear and anisotropic constitutive model based on the theory of the closed thick-walled tube. It was observed that initial highly deformable behavior (up to approximately 2.5kPa) in the pressure-circumferential stretch response is followed by progressive large strain stiffening. Contrary to that, samples were much stiffer in longitudinal direction, where the observed stretches were in the range 0.98-1.03 during the entire pressurization in most cases. The effect of possible residual stress was evaluated in a simulation of the intramural stress distribution with the opening angle prescribed to 0°, 10°, 20°, 30°, 40°, and 50°. The result suggests that the optimal opening angle making the stress distribution through the wall thickness uniform is about 40°. The material parameters presented here are suitable for use in mechanobiological simulations describing the adaptation of the autologous vein wall after bypass surgery.

  12. 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.

  13. Strategies to combat auditory overload during vehicular command and control.

    PubMed

    Abel, Sharon M; Ho, Geoffrey; Nakashima, Ann; Smith, Ingrid

    2014-09-01

    Strategies to combat auditory overload were studied. Normal-hearing males were tested in a sound isolated room in a mock-up of a military land vehicle. Two tasks were presented concurrently, in quiet and vehicle noise. For Task 1 dichotic phrases were delivered over a communications headset. Participants encoded only those beginning with a preassigned call sign (Baron or Charlie). For Task 2, they agreed or disagreed with simple equations presented either over loudspeakers, as text on the laptop monitor, in both the audio and the visual modalities, or not at all. Accuracy was significantly better by 20% on Task 2 when the equations were presented visually or audiovisually. Scores were at least 78% correct for dichotic phrases presented over the headset, with a right ear advantage of 7%, given the 5 dB speech-to-noise ratio. The left ear disadvantage was particularly apparent in noise, where the interaural difference was 12%. Relatively lower scores in the left ear, in noise, were observed for phrases beginning with Charlie. These findings underscore the benefit of delivering higher priority communications to the dominant ear, the importance of selecting speech sounds that are resilient to noise masking, and the advantage of using text in cases of degraded audio.

  14. Calcium overload increases oxidative stress in old rat gastrocnemius muscle.

    PubMed

    Capel, F; Demaison, L; Maskouri, F; Diot, A; Buffiere, C; Patureau Mirand, P; Mosoni, L

    2005-09-01

    In order to challenge in vivo muscle Ca2+ homeostasis and analyze consequences on mitochondrial H2O2 release (MHR) and sarcopenia, we injected Ca2+ ionophore A23187 (200 microg/kg, ip) in adult and old rats and measured gastrocnemius mass and mitochondrial Ca2+ content (MCC) using radioactive Ca2+ 48 h after injection. In a second experiment performed in old rats, we measured isocitrate dehydrogenase (ICDH) activity as an index of MCC, MHR, mitochondrial respiration, citrate synthase, COX and antioxydant enzyme activities 24 h after a 150 microg/kg injection. In adult rats, muscle mass and MCC were unchanged by A23187. In old rats, MCC increased 24 h after injection as reflected by a significant increase in ICDH activity; measured MCC tended to increase at 48 h. MHR and Mn-SOD activity were significantly increased at 24 h, and GPX activity was reduced. Muscle mass was unchanged but was negatively correlated with MCC in control and treated old rats. In conclusion, in old rats, A23187 probably induced a mitochondrial Ca2+ overload responsible for the observed increase in MHR without leading to muscle atrophy on a short term basis.

  15. 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

  16. Parallel deterministic transport sweeps of structured and unstructured meshes with overloaded mesh decompositions

    SciTech Connect

    Pautz, Shawn D.; Bailey, Teresa S.

    2016-11-29

    Here, the efficiency of discrete ordinates transport sweeps depends on the scheduling algorithm, the domain decomposition, the problem to be solved, and the computational platform. Sweep scheduling algorithms may be categorized by their approach to several issues. In this paper we examine the strategy of domain overloading for mesh partitioning as one of the components of such algorithms. In particular, we extend the domain overloading strategy, previously defined and analyzed for structured meshes, to the general case of unstructured meshes. We also present computational results for both the structured and unstructured domain overloading cases. We find that an appropriate amount of domain overloading can greatly improve the efficiency of parallel sweeps for both structured and unstructured partitionings of the test problems examined on up to 105 processor cores.

  17. Parallel deterministic transport sweeps of structured and unstructured meshes with overloaded mesh decompositions

    DOE PAGES

    Pautz, Shawn D.; Bailey, Teresa S.

    2016-11-29

    Here, the efficiency of discrete ordinates transport sweeps depends on the scheduling algorithm, the domain decomposition, the problem to be solved, and the computational platform. Sweep scheduling algorithms may be categorized by their approach to several issues. In this paper we examine the strategy of domain overloading for mesh partitioning as one of the components of such algorithms. In particular, we extend the domain overloading strategy, previously defined and analyzed for structured meshes, to the general case of unstructured meshes. We also present computational results for both the structured and unstructured domain overloading cases. We find that an appropriate amountmore » of domain overloading can greatly improve the efficiency of parallel sweeps for both structured and unstructured partitionings of the test problems examined on up to 105 processor cores.« less

  18. Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging.

    PubMed

    Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

    2013-12-01

    To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

  19. 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.

  20. Anemia and iron overload due to compound heterozygosity for novel ceruloplasmin mutations.

    PubMed

    Bosio, Sandra; De Gobbi, Marco; Roetto, Antonella; Zecchina, Gabriella; Leonardo, Eugenio; Rizzetto, Mario; Lucetti, Claudio; Petrozzi, Lucia; Bonuccelli, Ubaldo; Camaschella, Clara

    2002-09-15

    Aceruloplasminemia is a recessive disorder characterized by anemia, iron overload, and neurodegeneration, caused by the absence of ceruloplasmin (Cp), a multicopper oxidase important for iron export. Few patients homozygous for loss of function mutations of the Cp gene have been reported. We describe a 62-year-old white woman with heavy liver iron overload, diabetes, anemia, and neurologic symptoms. She was compound heterozygote for 2 novel mutations that result in the absence of hepatocyte Cp: an adenine insertion at nucleotide 2917 causing a truncated protein and a C-G transversion causing a glutamine-->glutamic acid substitution at position 146. Although rare in whites, aceruloplasminemia should be considered in the differential diagnosis of unexplained anemia associated with iron overload, because these features anticipate progressive neurologic symptoms. We propose that anemia, secondary to the impaired macrophage iron release, plays a major role in hepatic iron overload through increased absorption mediated by the erythroid regulator.

  1. Fatigue damage accumulation in steel 45 under loading regimes involving low-cycle overloads

    NASA Astrophysics Data System (ADS)

    Shlyushenkov, A. P.; Tatarintsev, V. A.

    1994-05-01

    The paper presents the results of experimental investigations into the regularities of fatigue damage accumulation in steel 45 under block loading involving elastoplastic (low-cycle) overloads. The experiments were carried out using the methods of the factorial design theory. Mathematical models are developed for damage accumulation depending on the variation of the parameters (factors) investigated: the level of the main (elastic) strain, the relative level of overloads, and their relative number.

  2. Synchrotron Based X-Ray Strain Mapping in Fatigued Materials Subjected to Overloading

    DTIC Science & Technology

    2006-01-01

    relevant: to measurements techniques for measurements in various deformation processes such as residual stress analysis; to various manufacturing and...fatigued, overload-fatigued Cyclic plastic and fatigued-overload-fatigued deformation . The residual zone stress distributions behind the crack tip are...measurements providing some insight into the complex multi-axial deformations that occur The thrust of this 2.862 -400 study is that the detailed mapping

  3. Dietary overload lithium decreases the adipogenesis in abdominal adipose tissue of broiler chickens.

    PubMed

    Bai, Shiping; Pan, Shuqin; Zhang, Keying; Ding, Xuemei; Wang, Jianping; Zeng, Qiufeng; Xuan, Yue; Su, Zuowei

    2017-01-01

    To investigate the toxic effects of dietary overload lithium on the adipogenesis in adipose tissue of chicken and the role of hypothalamic neuropeptide Y (NPY) in this process, one-day-old male chicks were fed with the basal diet added with 0 (control) or 100mg lithium/kg diet from lithium chloride (overload lithium) for 35days. Abdominal adipose tissue and hypothalamus were collected at day 6, 14, and 35. As a percentage of body weight, abdominal fat decreased (p<0.001) at day 6, 14, and 35, and feed intake and body weight gain decreased during day 7-14, and day 15-35 in overload lithium treated broilers as compared to control. Adipocyte diameter and DNA content in abdominal adipose tissue were significantly lower in overload-lithium treatment than control at day 35, although no significant differences were observed at day 6 and 14. Dietary overload lithium decreased (p<0.01) transcriptional expression of preadipocyte proliferation makers ki-67 (KI67), microtubule-associated protein homolog (TPX2), and topoisomerase 2-alpha (TOP2A), and preadipocyte differentiation transcriptional factors peroxisome proliferator-activated receptor-γ (PPARγ), and CCAAT/enhancer binding protein (C/EBP) α mRNA abundance in abdominal adipose tissue. In hypothalamus, dietary overload lithium influenced (p<0.001) NPY, and NPY receptor (NPYR) 6 mRNA abundance at day 6 and 14, but not at day 35. In conclusion, dietary overload lithium decreased the adipogenesis in abdominal adipose tissue of chicken, which was accompanied by depressing transcriptional expression of adipogenesis-associated factors. Hypothalamic NPY had a potential role in the adipogenesis in abdominal adipose tissue of broilers with a short-term overload lithium treatment.

  4. [Iron deficiency and overload. Implications in oxidative stress and cardiovascular health].

    PubMed

    Toxqui, L; De Piero, A; Courtois, V; Bastida, S; Sánchez-Muniz, F J; Vaquero, Ma P

    2010-01-01

    Although iron is an essential mineral for maintaining good health, excessive amounts are toxic. Nowadays, much interest is focused on the mechanisms and regulation of iron metabolism by down-regulation of the hormone hepcidin. The HAMP gene encodes for hepcidin appears to be exceptionally preserved. Disorders of iron metabolism could lead to iron overload, mainly causing the rare disease hereditary hemochromatosis, or on the other hand, iron deficiency and iron deficiency anaemia. Currently, these alterations constitute an important problem of public health. The genetic variation implicated in iron overload and iron deficiency anaemia, involves mutations in several genes such as HFE, TFR2,HAMP, HJV, Tf and TMPRSS6. Iron has the capacity to accept and donate electrons easily and can catalyze reactions of free radicals production. Therefore, iron overload causes lipid peroxidation and increases cardiovascular risk. Recently, a relationship between iron metabolism and insulin resistance and obesity has been described. In contrast, regarding a possible relationship between iron deficiency anaemia and cardiovascular disease, many aspects remain controversial. This review presents an overview of the most recent information concerning iron metabolism, iron bioavailability and iron overload/deficiency related diseases. The relation between iron and cardiovascular risk, in iron overload and in iron deficiency situations, is also examined. Finally, strategies to modify dietary iron bioavailability in order to prevent iron deficiency or alleviate iron overload are suggested.

  5. “Hydraulic Cushion” Type Overload Protection Devices Usable in Mechanical Presses. A Patent Study

    NASA Astrophysics Data System (ADS)

    Cioară, R.

    2016-11-01

    The possible consequences of machine-tool overload are well-known. In order to prevent such, machine-tools are equipped with various overload protection devices. Mechanical presses, intensively strained machine-tools, are typically equipped with three protection systems: against accidental access to the working area during machine deployment, against torque overload and force overload. Force overload protection systems include either destructible parts and are used in small to medium nominal force mechanical presses, or non-destructible ones used mostly in medium to large nominal force (H-frame) presses. A particular class of force overload protection systems without destructible parts are “hydraulic cushion” type devices. While such systems do not necessarily cause the machine to stop, the slide's stroke does not reach the initial dead centre and consequently cannot exert the designed technological force on the workpiece. By a patent study referencing 19 relevant patents the paper captures both the diversity of the constrictive solutions of “hydraulic cushion” type protection devices and their positioning modalities within the structure of a mechanical press. An important aim of the study is to highlight the reserve of creativity existing in this field, at least from the viewpoint of the hydraulic cushion positioning, as well as to emphasize the essential requirement of a relative motion between the mobile and the fixed parts of the tool, a motion of opposite sense to that of the slide-crank mechanism.

  6. Repeated subrupture overload causes progression of nanoscaled discrete plasticity damage in tendon collagen fibrils.

    PubMed

    Veres, Samuel P; Harrison, Julia M; Lee, J Michael

    2013-05-01

    A critical feature of tendons and ligaments is their ability to resist rupture when overloaded, resulting in strains or sprains instead of ruptures. To treat these injuries more effectively, it is necessary to understand how overload affects the primary load-bearing elements of these tissues: collagen fibrils. We have investigated how repeated subrupture overload alters the collagen of tendons at the nanoscale. Using scanning electron microscopy to examine fibril morphology and hydrothermal isometric tension testing to look at molecular stability, we demonstrated that tendon collagen undergoes a progressive cascade of discrete plasticity damage when repeatedly overloaded. With successive overload cycles, fibrils develop an increasing number of kinks along their length. These kinks-discrete zones of plastic deformation known to contain denatured collagen molecules-are accompanied by a progressive and eventual total loss of D-banding along the surface of fibrils, indicating a loss of native molecular packing and further molecular denaturation. Thermal analysis of molecular stability showed that the destabilization of collagen molecules within fibrils is strongly related to the amount of strain energy dissipated by the tendon after yielding during tensile overload. These novel findings raise new questions about load transmission within tendons and their fibrils and about the interplay between crosslinking, strain-energy dissipation ability, and molecular denaturation within these structures.

  7. Clinical outcomes of transfusion-associated iron overload in patients with refractory chronic anemia

    PubMed Central

    Gao, Chong; Li, Li; Chen, Baoan; Song, Huihui; Cheng, Jian; Zhang, Xiaoping; Sun, Yunyu

    2014-01-01

    Background The purpose of this study was to evaluate the clinical outcomes of transfusion-associated iron overload in patients with chronic refractory anemia. Methods Clinical manifestations, main organ function, results of computed tomography (CT), endocrine evaluation, and serum ferritin levels were analyzed retrospectively in 13 patients who were transfusion-dependent for more than 1 year (receiving >50 units of red blood cells) to determine the degree of iron overload and efficacy of iron-chelating therapy. Results Serum ferritin levels increased to 1,830–5,740 ng/mL in all patients. Ten patients had abnormal liver function. The CT Hounsfield units in the liver increased significantly in eleven patients, and were proportional to their serum ferritin levels. Skin pigmentation, liver dysfunction, and endocrine dysfunction were observed in nine patients with serum ferritin >3,500 ng/mL, eight of whom have since died. Interestingly, serum ferritin levels did not decrease significantly in nine transfusion-dependent patients who had received 15–60 days of iron-chelating therapy. Conclusion Transfusion-dependent patients may progress to secondary iron overload with organ impairment, which may be fatal in those who are heavily iron-overloaded. The CT Hounsfield unit is a sensitive indicator of iron overload in the liver. Iron chelation therapy should be initiated when serum ferritin is >1,000 ng/mL and continued until it is <1,000 ng/mL in transfusional iron-overloaded patients. PMID:24790419

  8. Taurine supplementation reduces oxidative stress and protects the liver in an iron-overload murine model

    PubMed Central

    ZHANG, ZEYU; LIU, DAN; YI, BO; LIAO, ZHANGPING; TANG, LEI; YIN, DONG; HE, MING

    2014-01-01

    We previously demonstrated that iron overload induces liver damage by causing the formation of reactive oxygen species (ROS). Taurine is a potent free radical scavenger that attenuates the damage caused by excessive oxygen free radicals. Therefore, the aim of the present study was to investigate whether taurine could reduce the hepatotoxicity of iron overload with regard to ROS production. Mice were intraperitoneally injected with iron 5 days/week for 13 weeks to achieve iron overload. It was found that iron overload resulted in liver dysfunction, increased apoptosis and elevated oxidative stress. Taurine supplementation increased liver taurine levels by 40% and led to improved liver function, as well as a reduction in apoptosis, ROS formation and mitochondrial swelling and an attenuation in the loss of the mitochondrial membrane potential. Treatment with taurine mediated a reduction in oxidative stress in iron-overloaded mice, attenuated liver lipid peroxidation, elevated antioxidant enzyme activities and maintained reduced glutathione levels. These results indicate that taurine reduces iron-induced hepatic oxidative stress, preserves liver function and inhibits hepatocyte apoptosis. Therefore, taurine may be a potential therapeutic drug to reduce liver damage caused by iron overload. PMID:25201602

  9. Improving volume status by comprehensive dietary and dialytic sodium management in chronic hemodialysis patients.

    PubMed

    Penne, E Lars; Levin, Nathan W; Kotanko, Peter

    2010-01-01

    Chronic volume overload is highly prevalent in chronic hemodialysis patients and leads to hypertension, left ventricular hypertrophy and increased hospitalization and mortality rates. Volume overload is caused primarily by a positive sodium balance and can be improved by sodium restriction. The main sources of sodium excess are a high-sodium diet in the interdialytic period and a positive sodium balance during dialysis. Here we discuss different approaches to achieve neutral or negative sodium balance, including reducing dietary sodium intake, individualizing dialysate sodium prescription, abandonment of sodium profiling, and reducing saline infusion for treatment of intradialytic symptoms and as part of dialyzer rinsing and priming procedures. All of these approaches should be combined for a maximal reduction of volume overload.

  10. 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

  11. 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

  12. 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

  13. Cucurbitacin B Protects Against Pressure Overload Induced Cardiac Hypertrophy.

    PubMed

    Xiao, Yang; Yang, Zheng; Wu, Qing-Qing; Jiang, Xiao-Han; Yuan, Yuan; Chang, Wei; Bian, Zhou Yan; Zhu, Jin Xiu; Tang, Qi-Zhu

    2017-04-08

    Lack of effective anti-cardiac hypertrophy drugs creates a major cause for the increasing prevalence of heart failure. In the present study, we determined the anti-hypertrophy and anti-fibrosis potential of a natural plant triterpenoid, Cucurbitacin B both in vitro and in vivo. Aortic banding (AB) was performed to induce cardiac hypertrophy. After 1 week of surgery, mice were receive cucurbitacin B treatment (Gavage, 0.2 mg/kg body weight/2 day). Afer 4 weeks of AB, cucurbitacin B demonstrated a strong anti- hypertrophy and anti-fibrosis ability as evidenced by decreased of heart weight, myocardial cell cross-sectional area and interstitial fibrosis, ameliorated of systolic and diastolic abnormalities, normalized in gene expression of hypertrophic and fibrotic markers, reserved microvascular density in pressure overload induced hypertrophic mice. Cucurbitacin B also showed significant hypertrophy inhibitory effect in phenylephrine stimulated cardiomyocytes. The Cucurbitacin B-mediated mitigated cardiac hypertrophy was attributable to the increasing level of autophagy, which was associated with the blockade of Akt/mTOR/FoxO3a signal pathway, validated by SC79, MK2206, and 3-MA, the Akt agonist, inhibitor and autophagy inhibitor in vitro. The overexpression of constitutively active Akt completely abolished the Cucurbitacin B-mediated protection of cardiac hypertrophy in human cardiomyocytes AC16. Collectively, our findings suggest that cucurbitacin B protects against cardiac hypertrophy through increasing the autophagy level in cardiomyocytes, which is associated with the inhibition of Akt/mTOR/FoxO3a signal axis. This article is protected by copyright. All rights reserved.

  14. 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.

  15. Electrical short circuit and current overload tests on aircraft wiring

    NASA Astrophysics Data System (ADS)

    Cahill, Patricia

    1995-11-01

    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.

  16. Right and left ventricular function and myocardial scarring in adult patients with sickle cell disease: a comprehensive magnetic resonance assessment of hepatic and myocardial iron overload

    PubMed Central

    2013-01-01

    Background Patients with Sickle cell disease (SCD) who receive regular transfusions are at risk for developing cardiac toxicity from iron overload. The aim of this study was to assess right and left cardiac volumes and function, late gadolinium enhancement (LGE) and iron deposits in patients with SCD using CMR, correlating these values with transfusion burden, ferritin and hemoglobin levels. Methods Thirty patients with SCD older than 20 years of age were studied in a 1.5 T scanner and compared to age- and sex-matched normal controls. Patients underwent analysis of biventricular volumes and function, LGE and T2* assessment of the liver and heart. Results When compared to controls, patients with SCD presented higher left ventricular (LV) volumes with decreased ejection fraction (EF) with an increase in stroke volume (SV) and LV hypertrophy. The right ventricle (RV) also presented with a decreased EF and hypertrophy, with an increased end-systolic volume. Although twenty-six patients had increased liver iron concentrations (median liver iron concentration value was 11.83 ± 9.66 mg/g), only one patient demonstrated an abnormal heart T2* < 20 msec. Only four patients (13%) LGE, with only one patient with an ischemic pattern. Conclusions Abnormal heart iron levels and myocardial scars are not a common finding in SCD despite increased liver iron overload. The significantly different ventricular function seen in SCD compared to normal suggests the changes in RV and LV function may not be due to the anemia alone. Future studies are necessary to confirm this association. PMID:24050721

  17. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute cystitis; Acute bladder infection; Acute bacterial cystitis ... cause. Menopause also increases the risk for a urinary tract infection. The following also increase your chances of having ...

  18. Hepcidin induction limits mobilisation of splenic iron in a mouse model of secondary iron overload.

    PubMed

    Camberlein, Emilie; Abgueguen, Emmanuelle; Fatih, Nadia; Canonne-Hergaux, François; Leroyer, Patricia; Turlin, Bruno; Ropert, Martine; Brissot, Pierre; Loréal, Olivier

    2010-03-01

    Venesection has been proposed as a treatment for hepatic iron overload in a number of chronic liver disorders that are not primarily linked to mutations in iron metabolism genes. Our aim was to analyse the impact of venesection on iron mobilisation in a mouse model of secondary iron overload. C57Bl/6 mice were given oral iron supplementation with or without phlebotomy between day 0 (D0) and D22, and the results were compared to controls without iron overload. We studied serum and tissue iron parameters, mRNA levels of hepcidin1, ferroportin, and transferrin receptor 1, and protein levels of ferroportin in the liver and spleen. On D0, animals with iron overload displayed elevations in iron parameters and hepatic hepcidin1 mRNA. By D22, in the absence of phlebotomies, splenic iron had increased, but transferrin saturation had decreased. This was associated with high hepatic hepcidin1 mRNA, suggesting that iron bioavailability decreased due to splenic iron sequestration through ferroportin protein downregulation. After 22days with phlebotomy treatments, control mice displayed splenic iron mobilisation that compensated for the iron lost due to phlebotomy. In contrast, phlebotomy treatments in mice with iron overload caused anaemia due to inadequate iron mobilisation. In conclusion, our model of secondary iron overload led to decreased plasma iron associated with an increase in hepcidin expression and subsequent restriction of iron export from the spleen. Our data support the importance of managing hepcidin levels before starting venesection therapy in patients with secondary iron overload that are eligible for phlebotomy.

  19. Logarithmic quantitation model using serum ferritin to estimate iron overload in secondary haemochromatosis.

    PubMed

    Güngör, T; Rohrbach, E; Solem, E; Kaltwasser, J P; Kornhuber, B

    1996-04-01

    Nineteen children and adolescents receiving repeated transfusions and subcutaneous desferrioxamine treatment were investigated in an attempt to quantitate iron overload non-invasively. Before patients were started on desferrioxamine individual relationships were correlated for 12 to 36 months between transfused iron, absorbed iron estimated gastrointestinally, and increasing serum ferritin concentrations. Patients with inflammation, increased liver enzymes, or haemolysis were excluded from analysis. The relationship between the variables could be described by a logarithmic regression curve (y = transfused iron [plus eventually gastrointestinally absorbed iron] = iron overload = a+b log [x = serum ferritin]) for each individual patient. All patients showed close correlation (R2) between x and y (median R2 of 0.909, 0.98, and 0.92 in thalassaemia, aplastic anaemia, and sickle cell anaemia patients, respectively). When started on desferrioxamine, current serum ferritin concentrations were used to derive the iron overload from each individual regression curve. The derived estimated iron overload ranged from 0.6 g to 31 g. Left ventricular dilatation was observed in three patients with beta thalassaemia and in one patient with aplastic anaemia with median iron overload of 20.7 (14.1-31.3) g and 24.0 g respectively. Hypothyroidism was found in four patients with beta thalassaemia and one patient with aplastic anaemia with iron overload between 14.7 (6.8 and 26.1) g and 15.1 g respectively. Human growth hormone deficiency was detected in three patients with beta thalassaemia with an iron overload of 4.2 (3.5-6.8) g; all three patients had excellent desferrioxamine compliance.

  20. Peroxidation in intestinal mucosa of normal and iron-overloaded rats differing in selenium status

    SciTech Connect

    Mahoney, A.W.; Vega, S. )

    1991-03-15

    Material in the digesta may lead to lipid peroxidation of the intestinal mucosa. To study the effect of Se deficiency ({minus}Se) and Fe overload (++Fe) on mucosal free radical damage, 60 220g rats in four groups were fed torula yeast diet for 20d. Fe-overload was caused in two groups by three IM injections of Fe dextran given on days 4, 9, and 14. Fe-control rats (+Fe) were sham-injected with n-saline. Se-control rats (+Se) were given Na{sub 2}SeO{sub 3}-supplemented drinking water. Se deficiency reduced liver and mucosal glutathione peroxidase activity, but Fe overload did not. Serum, liver and mucosal Fe was higher in the Fe-overloaded rats. Fe and Se treatments did not affect hemoglobin level, but Fe-overload reduced weight gain. Fe overload increased liver and mucosal thiobarbituric acid reactive substances (TBARS), but Se status did not affect them. On days 5-9, CBrCL{sub 3}, an environmental pollutant and lipid peroxidation initiator which must be activated by cytochrome P-450, was gavaged in 10 rats from each group; the higher dose increased mucosal TBARS in Fe-overloaded rats but not Se-deficient ones. But, the lower CBrCL{sub 3} dose did not affect mucosal TBARS. Liver TBARS was not affected by CBrCL{sub 3}; however, the highest liver and mucosal TBARS levels occurred in the {minus}Se++Fe rats given the higher CBrCL{sub 3} dose. Liver cytochrome P-450 activity was not affected by Fe{minus} nor Se status.

  1. Evolution of residual-strain distribution through an overload-induced retardation period during fatigue-crack growth

    NASA Astrophysics Data System (ADS)

    Lee, S. Y.; Sun, Y.; An, K.; Choo, H.; Hubbard, C. R.; Liaw, P. 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.

  2. Bmp6 Expression in Murine Liver Non Parenchymal Cells: A Mechanism to Control their High Iron Exporter Activity and Protect Hepatocytes from Iron Overload?

    PubMed Central

    Rausa, Marco; Pagani, Alessia; Nai, Antonella; Campanella, Alessandro; Gilberti, Maria Enrica; Apostoli, Pietro; Camaschella, Clara; Silvestri, Laura

    2015-01-01

    Bmp6 is the main activator of hepcidin, the liver hormone that negatively regulates plasma iron influx by degrading the sole iron exporter ferroportin in enterocytes and macrophages. Bmp6 expression is modulated by iron but the molecular mechanisms are unknown. Although hepcidin is expressed almost exclusively by hepatocytes (HCs), Bmp6 is produced also by non-parenchymal cells (NPCs), mainly sinusoidal endothelial cells (LSECs). To investigate the regulation of Bmp6 in HCs and NPCs, liver cells were isolated from adult wild type mice whose diet was modified in iron content in acute or chronic manner and in disease models of iron deficiency (Tmprss6 KO mouse) and overload (Hjv KO mouse). With manipulation of dietary iron in wild-type mice, Bmp6 and Tfr1 expression in both HCs and NPCs was inversely related, as expected. When hepcidin expression is abnormal in murine models of iron overload (Hjv KO mice) and deficiency (Tmprss6 KO mice), Bmp6 expression in NPCs was not related to Tfr1. Despite the low Bmp6 in NPCs from Tmprss6 KO mice, Tfr1 mRNA was also low. Conversely, despite body iron overload and high expression of Bmp6 in NPCs from Hjv KO mice, Tfr1 mRNA and protein were increased. However, in the same cells ferritin L was only slightly increased, but the iron content was not, suggesting that Bmp6 in these cells reflects the high intracellular iron import and export. We propose that NPCs, sensing the iron flux, not only increase hepcidin through Bmp6 with a paracrine mechanism to control systemic iron homeostasis but, controlling hepcidin, they regulate their own ferroportin, inducing iron retention or release and further modulating Bmp6 production in an autocrine manner. This mechanism, that contributes to protect HC from iron loading or deficiency, is lost in disease models of hepcidin production. PMID:25860887

  3. Bmp6 expression in murine liver non parenchymal cells: a mechanism to control their high iron exporter activity and protect hepatocytes from iron overload?

    PubMed

    Rausa, Marco; Pagani, Alessia; Nai, Antonella; Campanella, Alessandro; Gilberti, Maria Enrica; Apostoli, Pietro; Camaschella, Clara; Silvestri, Laura

    2015-01-01

    Bmp6 is the main activator of hepcidin, the liver hormone that negatively regulates plasma iron influx by degrading the sole iron exporter ferroportin in enterocytes and macrophages. Bmp6 expression is modulated by iron but the molecular mechanisms are unknown. Although hepcidin is expressed almost exclusively by hepatocytes (HCs), Bmp6 is produced also by non-parenchymal cells (NPCs), mainly sinusoidal endothelial cells (LSECs). To investigate the regulation of Bmp6 in HCs and NPCs, liver cells were isolated from adult wild type mice whose diet was modified in iron content in acute or chronic manner and in disease models of iron deficiency (Tmprss6 KO mouse) and overload (Hjv KO mouse). With manipulation of dietary iron in wild-type mice, Bmp6 and Tfr1 expression in both HCs and NPCs was inversely related, as expected. When hepcidin expression is abnormal in murine models of iron overload (Hjv KO mice) and deficiency (Tmprss6 KO mice), Bmp6 expression in NPCs was not related to Tfr1. Despite the low Bmp6 in NPCs from Tmprss6 KO mice, Tfr1 mRNA was also low. Conversely, despite body iron overload and high expression of Bmp6 in NPCs from Hjv KO mice, Tfr1 mRNA and protein were increased. However, in the same cells ferritin L was only slightly increased, but the iron content was not, suggesting that Bmp6 in these cells reflects the high intracellular iron import and export. We propose that NPCs, sensing the iron flux, not only increase hepcidin through Bmp6 with a paracrine mechanism to control systemic iron homeostasis but, controlling hepcidin, they regulate their own ferroportin, inducing iron retention or release and further modulating Bmp6 production in an autocrine manner. This mechanism, that contributes to protect HC from iron loading or deficiency, is lost in disease models of hepcidin production.

  4. Acute Effects of Caffeine on Heart Rate Variability, Blood Pressure and Tidal Volume in Paraplegic and Tetraplegic Compared to Able-Bodied Individuals: A Randomized, Blinded Trial

    PubMed Central

    Flueck, Joelle Leonie; Schaufelberger, Fabienne; Lienert, Martina; Schäfer Olstad, Daniela; Wilhelm, Matthias; Perret, Claudio

    2016-01-01

    Caffeine increases sympathetic nerve activity in healthy individuals. Such modulation of nervous system activity can be tracked by assessing the heart rate variability. This study aimed to investigate the influence of caffeine on time- and frequency-domain heart rate variability parameters, blood pressure and tidal volume in paraplegic and tetraplegic compared to able-bodied participants. Heart rate variability was measured in supine and sitting position pre and post ingestion of either placebo or 6 mg caffeine in 12 able-bodied, 9 paraplegic and 7 tetraplegic participants in a placebo-controlled, randomized and double-blind study design. Metronomic breathing was applied (0.25 Hz) and tidal volume was recorded during heart rate variability assessment. Blood pressure, plasma caffeine and epinephrine concentrations were analyzed pre and post ingestion. Most parameters of heart rate variability did not significantly change post caffeine ingestion compared to placebo. Tidal volume significantly increased post caffeine ingestion in able-bodied (p = 0.021) and paraplegic (p = 0.036) but not in tetraplegic participants (p = 0.34). Systolic and diastolic blood pressure increased significantly post caffeine in able-bodied (systolic: p = 0.003; diastolic: p = 0.021) and tetraplegic (systolic: p = 0.043; diastolic: p = 0.042) but not in paraplegic participants (systolic: p = 0.09; diastolic: p = 0.33). Plasma caffeine concentrations were significantly increased post caffeine ingestion in all three groups of participants (p<0.05). Plasma epinephrine concentrations increased significantly in able-bodied (p = 0.002) and paraplegic (p = 0.032) but not in tetraplegic participants (p = 0.63). The influence of caffeine on the autonomic nervous system seems to depend on the level of lesion and the extent of the impairment. Therefore, tetraplegic participants may be less influenced by caffeine ingestion. Trial Registration ClinicalTrials.gov NCT02083328 PMID:27776149

  5. Body Sodium Overload Modulates the Firing Rate and Fos Immunoreactivity of Serotonergic Cells of Dorsal Raphe Nucleus

    PubMed Central

    Godino, Andrea; Pitra, Soledad; Carrer, Hugo F.; Vivas, Laura

    2013-01-01

    In order to determine whether serotonergic (5HT) dorsal raphe nucleus (DRN) cells are involved in body sodium status regulation, the effect of a s.c. infusion of either 2 M or 0.15 M NaCl on 5HT DRN neuron firing was studied using single unit extracellular recordings. In separate groups of 2 M and 0.15 M NaCl-infused rats, water intake, oxytocin (OT) plasma concentration, urine and plasma sodium and protein concentrations were also measured. Also, to determine the involvement of particular brain nuclei and neurochemical systems in body sodium overload (SO), animals from both groups were perfused for brain immunohistochemical detection of Fos, Fos-OT and Fos-5HT expression. SO produced a significant increase in serotonergic DRN neuron firing rate compared to baseline and 0.15 M NaCl-infused rats. As expected, 2 M NaCl s.c. infusion also induced a significant increase of water intake, diuresis and natriuresis, plasma sodium concentration and osmolality, even though plasma volume did not increase as indicated by changes in plasma protein concentration. The distribution of neurons along the forebrain and brainstem expressing Fos after SO showed the participation of the lamina terminalis, extended amygdala, supraoptic and paraventricular hypothalamic nuclei in the neural network that controls osmoregulatory responses. Both Fos-OT immunoreactive and plasma OT concentration increased after s.c. hypertonic sodium infusion. Finally, matching the “in vivo” electrophysiological study, SO doubled the number of Fos-5HT immunolabeled cells within the DRN. In summary, the results characterize the behavioral, renal and endocrine responses after body sodium overload without volume expansion and specify the cerebral nuclei that participate at different CNS levels in the control of these responses. The electrophysiological approach also allows us to determine in an “in vivo" model that DRN 5HT neurons increase their firing frequency during an increase in systemic sodium

  6. Morphologic investigations of the guinea pig model of iron overload.

    PubMed

    Schwartz, K A; Fisher, J; Adams, E T

    1993-01-01

    We have developed a guinea pig model of iron overload toxicity. Animals were administered intraperitoneal iron dextran 3 times a week to achieve total body iron load of 0.25, 0.5, 1.0, 1.5, and 2.0 g Fe/kg body weight in less than 30 days. Quantitation of tissue iron levels with atomic absorption indicated increased iron deposition in liver and heart of the iron-loaded guinea pigs (p < 0.001). Additionally, the iron-loaded pigs demonstrated decreased nuclear magnetic resonance spectroscopy T1 relaxation times in both liver and heart (p < 0.001). Serum iron, total body iron capacity, and transferrin saturation values were also determined in guinea pigs treated with 0.25, 0.5, and 1.0 g Fe/kg body weight. Serum iron and total iron-binding capacity were significantly increased at 0.5 and 1.0 g Fe/kg; transferrin saturation was elevated at 0.25 and 1.0 g Fe/kg. kg. Histologic examination of liver, heart, and bone marrow as well as ultrastructural studies on liver and heart confirmed increased iron deposition in treated animals. At the low iron dose level of 0.5 g Fe/kg, liver iron particles were primarily confined to Kupffer cells with minimal hepatocellular localization. Increased hepatocellular iron deposition was observed with larger doses of loaded iron. Myocardial iron was most prominent in interstitial cells of the epicardium, endocardium, myocardium, and coronary adipose tissue. Ultrastructurally, the presence of iron particles in perinuclear, membrane-bound structures (consistent with lysosomes) was confirmed using x-ray microanalysis. These morphological studies suggest that in this animal model siderosis of hepatic mononuclear phagocyte and myocardial interstitial cells may be the initial lesions leading to further biochemical and functional abnormalities. Correlation between tissue iron measurements and both light and electron microscopic changes, presented in this report, serve to introduce the iron-loaded guinea pig as a model for the study of iron

  7. Membrane bioreactor (MBR) sludge inoculation in a hybrid process scheme concept to assist overloaded conventional activated sludge (CAS) process operations.

    PubMed

    Fenu, A; Roels, J; Van Damme, S; Wambecq, T; Weemaes, M; Thoeye, C; De Gueldre, G; Van De Steene, B

    2012-01-01

    This study analyzes the effect of inoculating membrane bioreactor (MBR) sludge in a parallel-operated overloaded conventional activated sludge (CAS) system. Modelling studies that showed the beneficial effect of this inoculation were confirmed though full scale tests. Total nitrogen (TN) removal in the CAS increased and higher nitrate formation rates were achieved. During MBR sludge inoculation, the TN removal in the CAS was proven to be dependent on MBR sludge loading. Special attention was given to the effect of inoculation on sludge quality. The MBR flocs, grown without selection pressure, were clearly distinct from the more compact flocs in the CAS system and also contained more filamentous bacteria. After inoculation the MBR flocs did not evolve into good-settling compact flocs, resulting in a decreasing sludge quality. During high flow conditions the effluent CAS contained more suspended solids. Sludge volume index, however, did not increase. Laboratory tests were held to determine the threshold volume of MBR sludge to be seeded into the CAS reactor. Above 16-30%, supernatant turbidity and scum formation increased markedly.

  8. To Be Connected or Not To Be Connected? Mobile Messenger Overload, Fatigue, and Mobile Shunning.

    PubMed

    Shin, Jaewook; Shin, Mincheol

    2016-10-01

    With the increased adoption of mobile devices, mobile communication is all around us and we are connected anywhere, anytime. Mobile communication in general and mobile messenger service in particular make interpersonal communication in Korea so frequent and convenient. However, being connected too much anywhere and anytime via mobile messenger service appears to lead an increasing number of people to feel fatigue and to decrease mobile communication under some conditions. Based on a sample of 334 respondents, this study empirically investigated the relationships among commercial, noncommercial mobile messenger overload, mobile messenger fatigue, relational self-concept, and mobile shunning behavior. The findings show that (a) the effect of noncommercial mobile messenger overload is stronger than that of commercial mobile messenger overload in increasing mobile messenger fatigue although both positively affect mobile messenger fatigue, (b) relational self-concept has moderating effects on the relationship between mobile messenger overload and mobile messenger fatigue, and that (c) mobile messenger fatigue triggers mobile communicators' shunning behavior through which the communicators increase their intention to avoid mobile communication, to change their mobile phone numbers, and to subscribe to dual number service on one mobile device. When confronted with mobile messenger fatigue caused by mobile messenger overload, mobile messaging service users are likely to shun their mobile communication. Being constantly and conveniently connected appears to be a blessing in disguise.

  9. Impact of iron overload and potential benefit from iron chelation in low-risk myelodysplastic syndrome.

    PubMed

    Shenoy, Niraj; Vallumsetla, Nishanth; Rachmilewitz, Eliezer; Verma, Amit; Ginzburg, Yelena

    2014-08-07

    Myelodysplastic syndromes (MDSs) are a group of heterogeneous clonal bone marrow disorders characterized by ineffective hematopoiesis, peripheral blood cytopenias, and potential for malignant transformation. Lower/intermediate-risk MDSs are associated with longer survival and high red blood cell (RBC) transfusion requirements resulting in secondary iron overload. Recent data suggest that markers of iron overload portend a relatively poor prognosis, and retrospective analysis demonstrates that iron chelation therapy is associated with prolonged survival in transfusion-dependent MDS patients. New data provide concrete evidence of iron's adverse effects on erythroid precursors in vitro and in vivo. Renewed interest in the iron field was heralded by the discovery of hepcidin, the main serum peptide hormone negative regulator of body iron. Evidence from β-thalassemia suggests that regulation of hepcidin by erythropoiesis dominates regulation by iron. Because iron overload develops in some MDS patients who do not require RBC transfusions, the suppressive effect of ineffective erythropoiesis on hepcidin may also play a role in iron overload. We anticipate that additional novel tools for measuring iron overload and a molecular-mechanism-driven description of MDS subtypes will provide a deeper understanding of how iron metabolism and erythropoiesis intersect in MDSs and improve clinical management of this patient population.

  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.

  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. Magnetocardiograms of patients with left ventricular overloading recorded with a second-derivative SQUID gradiometer.

    PubMed

    Fujino, K; Sumi, M; Saito, K; Murakami, M; Higuchi, T; Nakaya, Y; Mori, H

    1984-07-01

    Magnetocardiograms (MCGs) were recorded by means of a second-derivative SQUID (superconducting quantum interference device) magnetometer in 60 normal subjects and 95 patients with left ventricular overloading to determine the clinical value of the MCG. In patients with left ventricular overloading, the Q or S wave was increased in the upper anterior part of the thorax, and the R wave was increased in the left lower part of the thorax, indicating increased leftward force due to left ventricular overloading. For detection of left ventricular hypertrophy or dilatation from echocardiographic measurements, the sensitivity and specificity of the MCG were similar to those of the standard ECG, or slightly better. In patients with left ventricular systolic overloading, the Q wave was decreased in the lower anterior part of the thorax, indicating a decreased septal vector. Inversion of the T wave was seen more frequently in the MCGs than in the ECGs of patients with left ventricular overloading, suggesting that the MCG is useful for detecting early abnormalities of repolarization. These results suggest that the MCG may provide information that is difficult to obtain from the standard 12-lead ECG.

  13. Mechanically overloading collagen fibrils uncoils collagen molecules, placing them in a stable, denatured state.

    PubMed

    Veres, Samuel P; Harrison, Julia M; Lee, J Michael

    2014-01-01

    Due to the high occurrence rate of overextension injuries to tendons and ligaments, it is important to understand the fundamental mechanisms of damage to these tissues' primary load-bearing elements: collagen fibrils and their constituent molecules. Based on our recent observations of a new subrupture, overload-induced mode of fibril disruption that we call discrete plasticity, we have sought in the current study to re-explore whether the tensile overload of collagen fibrils can alter the helical conformation of collagen molecules. In order to accomplish this, we have analyzed the conformation of collagen molecules within repeatedly overloaded tendons in relation to their undamaged matched-pair controls using both differential scanning calorimetry and variable temperature trypsin digestion susceptibility. We find that tensile overload reduces the specific enthalpy of denaturation of tendons, and increases their susceptibility to trypsin digestion, even when the digestion is carried out at temperatures as low as 4 °C. Our results indicate that the tensile overload of collagen fibrils can uncoil the helix of collagen molecules, placing them in a stable, denatured state.

  14. Iron overload detection in rats by means of a susceptometer operating at room temperature

    NASA Astrophysics Data System (ADS)

    Marinelli, M.; Gianesin, B.; Avignolo, C.; Minganti, V.; Parodi, S.

    2008-12-01

    Biosusceptometry is a non-invasive procedure for determination of iron overload in a human body; it is essentially an assessment of the diamagnetic (water) and paramagnetic (iron) properties of tissues. We measured in vivo iron overload in the liver region of 12 rats by a room temperature susceptometer. The rats had been injected with sub-toxic doses of iron dextran. A quantitative relationship has been observed between the measurements and the number of treatments. The assessment of iron overload requires evaluating the magnetic signal corresponding to the same rat ideally without the overload. This background value was extrapolated on the basis of the signal measured in control rats versus body weight (R2 = 0.73). The mean iron overload values for the treated rats, obtained after each iron injection, were significantly different from the means of the corresponding control rats (p < 0.01). The in vivo measurements have been complemented by chemical analysis on excised livers and other organs (R2 = 0.89). The magnetic moment of iron atoms in liver tissues was measured to be 3.6 Bohr magneton. Evaluation of the background signal is the limit to the measure; the error corresponds to about 30 mg (1 SD) of iron while the instrument sensitivity is more than a factor of 10 better.

  15. Syndecan-4 deficiency accelerates the transition from compensated hypertrophy to heart failure following pressure overload.

    PubMed

    Li, Guannan; Xie, Jun; Chen, Jianzhou; Li, Ran; Wu, Han; Zhang, Xinlin; Chen, Qinhua; Gu, Rong; Xu, Biao

    2017-03-30

    Increasing evidence suggests that a mismatch between angiogenesis and myocardial growth contributes to the transition from adaptive cardiac hypertrophy to heart failure following pressure overload. Syndecan-4 is a transmembrane proteoglycan that binds to growth factors and extracellular matrix proteins and is critical in focal adhesion formation. However, its effects on coronary angiogenesis during pressure overload-induced heart failure have not been studied. Here, we hypothesize that syndecan-4 modulates cardiac remodeling in response to pressure overload through its ability to regulate adaptive angiogenesis. Syndecan-4 knockout (syndecan-4 KO) and wild-type (WT) mice were subjected to pressure overload induced by transverse aortic constriction (TAC). Syndecan-4 KO mice exhibited reduced capillary density, attenuated cardiomyocyte size, and worsened left ventricular cardiac function after TAC surgery compared with WT mice. Moreover, syndecan-4 KO mice showed a significant decrease in protein kinase C alpha expression. Our data suggest that syndecan-4 is essential for the compensated hypertrophy and the maintenance of cardiac function during the process of heart failure following pressure overload.

  16. Relation between acute and late irradiation impairment of four basic tastes and irradiated tongue volume in patients with head-and-neck cancer

    SciTech Connect

    Yamashita, Hideomi . E-mail: yamachan07291973@yahoo.co.jp; Nakagawa, Keiichi; Nakamura, Naoki; Abe, Keiko; Asakage, Takahiro; Ohmoto, Makoto; Okada, Shinji; Matsumoto, Ichiro; Hosoi, Yoshio; Sasano, Nakashi; Yamakawa, Sen; Ohtomo, Kuni

    2006-12-01

    Purpose: Taste loss is a major cause of morbidity in patients undergoing head-and-neck irradiation. The relationship between the time course and the degree of taste disorder was studied in both acute and late phases. Methods and Materials: Taste ability was measured by the taste threshold for the four basic tastes using a filter paper disc method in patients before, during, and after radiotherapy. The subjects were divided into two groups. In Group A, Radiation fields included most of the tongue (n = 100), and in Group B Radiation fields did not include the tip of the tongue (n = 18). Results: In Group A, there was a significant impairment of the threshold of all four basic tastes at 3 weeks after starting radiotherapy (RT), and this impairment remained at 8 weeks (p < 0.05). This was not seen in Group B. In Group A, there was no significant difference in the patterns of taste sensitivity change between the high-dose (>20 Gy) and low-dose ({<=}20 Gy) groups. In the late phase, recovery of taste loss was seen in both groups since 4 months after completing RT. Conclusions: Unless the anterior part of the tongue was irradiated, taste loss was not observed during RT. When the anterior part of the tongue was irradiated, a difference by radiation dose was not observed in the taste loss pattern. Additionally, radiation-induced taste dysfunction appears to be a temporal effect.

  17. Psychological distance can improve decision making under information overload via gist memory.

    PubMed

    Fukukura, Jun; Ferguson, Melissa J; Fujita, Kentaro

    2013-08-01

    Making a decision can be especially difficult when it is based upon a large amount of information. A number of demonstrations in the literature suggest that decision making under information overload leads to suboptimal outcomes. In this article, we draw on construal level theory (Trope & Liberman, 2003) and fuzzy-trace theory (Brainerd & Reyna, 1993) to suggest that psychologically distancing oneself from the information can be beneficial to decision making under information overload. Specifically, we propose that distancing prompts organization of information in terms of its gist. Across 4 studies, we demonstrated that increasing spatial distance, temporal distance, and abstraction lead to better decision outcomes when decision makers were overloaded with many pieces of information per decision. Furthermore, we showed that the relationship between psychological distance and decision outcome is mediated by gist memory.

  18. 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.

  19. 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.

  20. 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.

  1. Dynamic Scheduling Real-Time Task Using Primary-Backup Overloading Strategy for Multiprocessor Systems

    NASA Astrophysics Data System (ADS)

    Sun, Wei; Yu, Chen; Défago, Xavier; Inoguchi, Yasushi

    The scheduling of real-time tasks with fault-tolerant requirements has been an important problem in multiprocessor systems. The primary-backup (PB) approach is often used as a fault-tolerant technique to guarantee the deadlines of tasks despite the presence of faults. In this paper we propose a dynamic PB-based task scheduling approach, wherein an allocation parameter is used to search the available time slots for a newly arriving task, and the previously scheduled tasks can be re-scheduled when there is no available time slot for the newly arriving task. In order to improve the schedulability we also propose an overloading strategy for PB-overloading and Backup-backup (BB) overloading. Our proposed task scheduling algorithm is compared with some existing scheduling algorithms in the literature through simulation studies. The results have shown that the task rejection ratio of our real-time task scheduling algorithm is almost 50% lower than the compared algorithms.

  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.

  4. Correlation between Ribosome Biogenesis and the Magnitude of Hypertrophy in Overloaded Skeletal Muscle

    PubMed Central

    Nakada, Satoshi; Ogasawara, Riki; Kawada, Shigeo; Maekawa, Takahiro; Ishii, Naokata

    2016-01-01

    External loads applied to skeletal muscle cause increases in the protein translation rate, which leads to muscle hypertrophy. Although some studies have demonstrated that increases in the capacity and efficiency of translation are involved in this process, it remains unclear how these two factors are related to the magnitude of muscle hypertrophy. The present study aimed to clarify the roles played by the capacity and efficiency of translation in muscle hypertrophy. We used an improved synergist ablation in which the magnitude of compensatory hypertrophy could be controlled by partial removal of synergist muscles. Male rats were assigned to four groups in which the plantaris muscle was unilaterally subjected to weak (WK), moderate (MO), middle (MI), and strong (ST) overloading by four types of synergist ablation. Fourteen days after surgery, the weight of the plantaris muscle per body weight increased by 8%, 22%, 32% and 45%, in the WK, MO, MI and ST groups, respectively. Five days after surgery, 18+28S rRNA content (an indicator of translational capacity) increased with increasing overload, with increases of 1.8-fold (MO), 2.2-fold (MI), and 2.5-fold (ST), respectively, relative to non-overloaded muscle (NL) in the WK group. rRNA content showed a strong correlation with relative muscle weight measured 14 days after surgery (r = 0.98). The phosphorylated form of p70S6K (a positive regulator of translational efficiency) showed a marked increase in the MO group, but no further increase was observed with further increase in overload (increases of 22.6-fold (MO), 17.4-fold (MI), and 18.2-fold (ST), respectively, relative to NL in the WK group). These results indicate that increases in ribosome biogenesis at the early phase of overloading are strongly dependent on the amount of overloading, and may play an important role in increasing the translational capacity for further gain of muscular size. PMID:26824605

  5. Correlation between Ribosome Biogenesis and the Magnitude of Hypertrophy in Overloaded Skeletal Muscle.

    PubMed

    Nakada, Satoshi; Ogasawara, Riki; Kawada, Shigeo; Maekawa, Takahiro; Ishii, Naokata

    2016-01-01

    External loads applied to skeletal muscle cause increases in the protein translation rate, which leads to muscle hypertrophy. Although some studies have demonstrated that increases in the capacity and efficiency of translation are involved in this process, it remains unclear how these two factors are related to the magnitude of muscle hypertrophy. The present study aimed to clarify the roles played by the capacity and efficiency of translation in muscle hypertrophy. We used an improved synergist ablation in which the magnitude of compensatory hypertrophy could be controlled by partial removal of synergist muscles. Male rats were assigned to four groups in which the plantaris muscle was unilaterally subjected to weak (WK), moderate (MO), middle (MI), and strong (ST) overloading by four types of synergist ablation. Fourteen days after surgery, the weight of the plantaris muscle per body weight increased by 8%, 22%, 32% and 45%, in the WK, MO, MI and ST groups, respectively. Five days after surgery, 18+28S rRNA content (an indicator of translational capacity) increased with increasing overload, with increases of 1.8-fold (MO), 2.2-fold (MI), and 2.5-fold (ST), respectively, relative to non-overloaded muscle (NL) in the WK group. rRNA content showed a strong correlation with relative muscle weight measured 14 days after surgery (r = 0.98). The phosphorylated form of p70S6K (a positive regulator of translational efficiency) showed a marked increase in the MO group, but no further increase was observed with further increase in overload (increases of 22.6-fold (MO), 17.4-fold (MI), and 18.2-fold (ST), respectively, relative to NL in the WK group). These results indicate that increases in ribosome biogenesis at the early phase of overloading are strongly dependent on the amount of overloading, and may play an important role in increasing the translational capacity for further gain of muscular size.

  6. Overload-induced skeletal muscle hypertrophy is not impaired in STZ-diabetic rats.

    PubMed

    Fortes, Marco Aurélio S; Pinheiro, Carlos Hermano J; Guimarães-Ferreira, Lucas; Vitzel, Kaio F; Vasconcelos, Diogo A A; Curi, Rui

    2015-07-01

    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.

  7. 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

  8. 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

  9. Acute Low-Volume High-Intensity Interval Exercise and Continuous Moderate-Intensity Exercise Elicit a Similar Improvement in 24-h Glycemic Control in Overweight and Obese Adults.

    PubMed

    Parker, Lewan; Shaw, Christopher S; Banting, Lauren; Levinger, Itamar; Hill, Karen M; McAinch, Andrew J; Stepto, Nigel K

    2016-01-01

    Background: Acute exercise reduces postprandial oxidative stress and glycemia; however, the effects of exercise intensity are unclear. We investigated the effect of acute low-volume high-intensity interval-exercise (LV-HIIE) and continuous moderate-intensity exercise (CMIE) on glycemic control and oxidative stress in overweight and obese, inactive adults. Methods: Twenty-seven adults were randomly allocated to perform a single session of LV-HIIE (9 females, 5 males; age: 30 ± 1 years; BMI: 29 ± 1 kg·m(-2); mean ± SEM) or CMIE (8 females, 5 males; age: 30 ± 2.0; BMI: 30 ± 2.0) 1 h after consumption of a standard breakfast. Plasma redox status, glucose and insulin were measured. Continuous glucose monitoring (CGM) was conducted during the 24-h period before (rest day) and after exercise (exercise day). Results: Plasma thiobarbituric acid reactive substances (TBARS; 29 ±13%, p < 0.01; mean percent change ±90% confidence limit), hydrogen peroxide (44 ± 16%, p < 0.01), catalase activity (50 ± 16%, p < 0.01), and superoxide dismutase activity (21 ± 6%, p < 0.01) significantly increased 1 h after breakfast (prior to exercise) compared to baseline. Exercise significantly decreased postprandial glycaemia in whole blood (-6 ± 5%, p < 0.01), irrespective of the exercise protocol. Only CMIE significantly decreased postprandial TBARS (CMIE: -33 ± 8%, p < 0.01; LV-HIIE: 11 ± 22%, p = 0.34) and hydrogen peroxide (CMIE: -25 ± 15%, p = 0.04; LV-HIIE: 7 ± 26%; p = 0.37). Acute exercise provided a similar significant improvement in 24-h average glucose levels (-5 ± 2%, p < 0.01), hyperglycemic excursions (-37 ± 60%, p < 0.01), peak glucose concentrations (-8 ± 4%, p < 0.01), and the 2-h postprandial glucose response to dinner (-9 ± 4%, p < 0.01), irrespective of the exercise protocol. Conclusion: Despite elevated postprandial oxidative stress compared to CMIE, LV-HIIE is an equally effective exercise mode for improving 24-h glycemic control in overweight and obese

  10. Acute Low-Volume High-Intensity Interval Exercise and Continuous Moderate-Intensity Exercise Elicit a Similar Improvement in 24-h Glycemic Control in Overweight and Obese Adults

    PubMed Central

    Parker, Lewan; Shaw, Christopher S.; Banting, Lauren; Levinger, Itamar; Hill, Karen M.; McAinch, Andrew J.; Stepto, Nigel K.

    2017-01-01

    Background: Acute exercise reduces postprandial oxidative stress and glycemia; however, the effects of exercise intensity are unclear. We investigated the effect of acute low-volume high-intensity interval-exercise (LV-HIIE) and continuous moderate-intensity exercise (CMIE) on glycemic control and oxidative stress in overweight and obese, inactive adults. Methods: Twenty-seven adults were randomly allocated to perform a single session of LV-HIIE (9 females, 5 males; age: 30 ± 1 years; BMI: 29 ± 1 kg·m−2; mean ± SEM) or CMIE (8 females, 5 males; age: 30 ± 2.0; BMI: 30 ± 2.0) 1 h after consumption of a standard breakfast. Plasma redox status, glucose and insulin were measured. Continuous glucose monitoring (CGM) was conducted during the 24-h period before (rest day) and after exercise (exercise day). Results: Plasma thiobarbituric acid reactive substances (TBARS; 29 ±13%, p < 0.01; mean percent change ±90% confidence limit), hydrogen peroxide (44 ± 16%, p < 0.01), catalase activity (50 ± 16%, p < 0.01), and superoxide dismutase activity (21 ± 6%, p < 0.01) significantly increased 1 h after breakfast (prior to exercise) compared to baseline. Exercise significantly decreased postprandial glycaemia in whole blood (−6 ± 5%, p < 0.01), irrespective of the exercise protocol. Only CMIE significantly decreased postprandial TBARS (CMIE: −33 ± 8%, p < 0.01; LV-HIIE: 11 ± 22%, p = 0.34) and hydrogen peroxide (CMIE: −25 ± 15%, p = 0.04; LV-HIIE: 7 ± 26%; p = 0.37). Acute exercise provided a similar significant improvement in 24-h average glucose levels (−5 ± 2%, p < 0.01), hyperglycemic excursions (−37 ± 60%, p < 0.01), peak glucose concentrations (−8 ± 4%, p < 0.01), and the 2-h postprandial glucose response to dinner (−9 ± 4%, p < 0.01), irrespective of the exercise protocol. Conclusion: Despite elevated postprandial oxidative stress compared to CMIE, LV-HIIE is an equally effective exercise mode for improving 24-h glycemic control in

  11. 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

  12. 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.

  13. Improving clinical outcome in patients with myelodysplastic syndrome and iron overload using iron chelation therapy.

    PubMed

    Leitch, Heather A

    2007-12-01

    Until recently, little information on the benefits of iron chelation therapy (ICT) in patients with myelodysplastic syndrome (MDS) and iron overload was known. A recent retrospective study showed improved survival in transfusion-dependent patients with MDS (Low or Intermediate-1 risk IPSS) receiving ICT, compared with those not receiving ICT; median overall survival was not reached at 160 months versus 40 months, respectively. Significantly more patients receiving ICT survived to 4 years (80% versus 44%; p < 0.03), suggesting that MDS patients with iron overload might benefit from ICT. Prospective studies to confirm the benefit of ICT in MDS are warranted.

  14. Iron overload complicating sideroblastic anemia--is the gene for hemochromatosis responsible?

    PubMed

    Barron, R; Grace, N D; Sherwood, G; Powell, L W

    1989-04-01

    Idiopathic hemochromatosis is a hereditary disease that is associated with human leucocytic antigens A3, B7, and B14. A genetic association between human leucocytic antigen-linked hemochromatosis and idiopathic refractory sideroblastic anemia has been suggested that may predispose some patients with idiopathic refractory sideroblastic anemia to develop gross iron overload. Study of the family of a patient with idiopathic refractory sideroblastic anemia and hemochromatosis revealed that 2 of 5 first-degree relatives had significant elevations of serum ferritin, and a shared human leucocytic antigen haplotype, supporting the concept that patients with idiopathic refractory sideroblastic anemia and significant iron overload have at least one allele for hemochromatosis.

  15. Overload training inhibits phagocytosis and ROS generation of peritoneal macrophages: role of IGF-1 and MGF.

    PubMed

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

    2013-01-01

    We tested the hypothesis that overload training inhibits the phagocytosis and the reactive oxygen species (ROS) generation of peritoneal macrophages (Mϕs), and that insulin-like growth factor-1(IGF-1) and mechano-growth factor (MGF) produced by macrophages may contribute to this process. Rats were randomized to two groups, sedentary control group (n = 10) and overload training group (n = 10). The rats of overload training group were subjected to 11 weeks of experimental training protocol. Blood sample was used to determine the content of hemoglobin, testosterone, and corticosterone. The phagocytosis and the ROS generation of Mϕs were measured by the uptake of neutral red and the flow cytometry, respectively. IGF-1 and MGF mRNA levels in Mϕs were determined by real-time PCR. In addition, we evaluated the effects of IGF-1 and MGF peptide on phagocytosis and ROS generation of Mϕs in vitro. The data showed that overload training significantly decreased the body weight (19.3 %, P < 0.01), the hemoglobin (13.5 %, P < 0.01), the testosterone (55.3 %, P < 0.01) and the corticosterone (40.6 %, P < 0.01) in blood. Moreover, overload training significantly decreased the phagocytosis (27 %, P < 0.05) and the ROS generation (35 %, P < 0.01) of Mϕs. IGF-1 and MGF mRNA levels in Mϕs from overload training group increased significantly compared with the control group (21-fold and 92-fold, respectively; P < 0.01). In vitro experiments showed that IGF-1 had no significant effect on the phagocytosis and the ROS generation of Mϕs. Unlike IGF-1, MGF peptide impaired the phagocytosis of Mϕs in dose-independent manner. In addition, MGF peptide of some concentrations (i.e., 1, 10, 50, 100 ng/ml) significantly inhibited the ROS generation of Mϕs. These results suggest that overload training inhibits the phagocytosis and the ROS generation of peritoneal macrophages, and that MGF produced by macrophages may play a key role in this process. This may represent a novel mechanism of

  16. 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

    Yoshida, Tadashi; Friehs, Ingeborg; Mummidi, Srinivas; del Nido, Pedro J; Addulnour-Nakhoul, Solange; Delafontaine, Patrice; Valente, Anthony J; Chandrasekar, Bysani

    2014-10-01

    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 4weeks (mass/volume ratio: 1.7±0.11) and ventricular dilatation indicative of heart failure at 6weeks (mass/volume ratio: 0.7±0.04). In concordance with this, fractional shortening was preserved at 4weeks, but markedly attenuated at 6weeks. 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, 1Hz) 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/GATA4 signaling. In contrast, IL-18 potentiated TNF-α-induced cardiomyocyte death, and by itself induced cardiac endothelial cell death. These results demonstrate that pressure overload is associated with enhanced IL-18 and its receptor expression in hypertrophied and failingrabbit hearts. Since IL-18BP expression is markedly inhibited, our results indicate a positive amplification in IL-18 proinflammatory signaling during pressure overload, and suggest IL-18 as a potential therapeutic target in pathological hypertrophy and cardiac failure.

  17. The effect of an acute antioxidant supplementation compared with placebo on performance and hormonal response during a high volume resistance training session

    PubMed Central

    2014-01-01

    Antioxidant supplementation is known to increase human endogenous antioxidant (AOX) capacity providing a means of blunting exercise induced reactive oxygen species (ROS). The purpose of this study was to compare the effects of a single acute dose of an AOX (vs blinded placebo) on muscle contractile performance and hormonal responses to a single bout of lower limb ‘hypertrophic’ resistance training (RT). Fifteen resistance trained subjects (age 23 ± 4 years: body mass 86 ± 6 kg) volunteered to participate in the study. Each subject attended the laboratory on three occasions, firstly to determine three repetition maximum (3-RM) isotonic strength in the back squat and perform a familiarisation of the experimental task. On the second/third visits subjects completed the hypertrophic training session (HTS) which consisted of six sets of 10 repetitions of 70% of a predicted 1 RM load (kg). Four hours prior to the HTS the subjects consumed 2 ml#x2219;kg−1 total body mass of either the placebo mixture or AOX supplement in a randomised order. Work completed during the strength training session was completed with equipment that had an integrated linear force transducer (Gymaware system, Kinetic Performance Technology, Canberra, Australia). During the placebo trials concentric mean power significantly (p < 0.05) decreased from sets 1–6. Accumulated power output during the AOX HTS was 6746 ± 5.9 W which was significantly greater compared to the placebo HTS of 6493 ± 17.1 W (p < 0.05, ES’r = 0.99). Plasma growth hormone (GH) concentration was significantly less immediately following AOX supplementation (6.65 ± 1.84 vs 16.08 ± 2.78 ng#x2219;ml−1; p < 0.05, ES’r = 0.89). This study demonstrates ingestion of an AOX cocktail prior to a single bout of resistance training improved muscle contractile performance and modulated the GH response following completion of the resistance exercise. Future studies should

  18. 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.…

  19. 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...

  20. 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

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  1. 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...

  2. 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...

  3. 30 CFR 77.506-1 - 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...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  4. 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...

  5. 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

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  6. 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

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  7. 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...

  8. 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

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  9. Plasma volume in isosmotic hypervolaemia.

    PubMed

    Kishegyi, J; Horváth, G; Kövér, G

    1978-01-01

    The Evans-blue distribution volume, haematocrit, and plasma protein concentration were investigated in non-hydrated (control), hydrated, and acutely nephrectomized hydrated, anaesthetized dogs. In control anaesthetized dogs a decrease of the plasma protein level was observed as part of the plasma proteins was lost into the extravascular space and did not return into the circulating plasma during the experimental period. Under the effect of hydration, the Evans-blue distribution volume increased significantly, while the haematocrit and plasma volume did not change. The phenomenon was ascribed to an increase in capillary permeability. During hydration following acute nephrectomy, the Evans-blue distribution volume increased but the haematocrit disecreased and the circulating plasma volume increased. It is concluded that a material (or materials) orginating from the kidney may influence capillary permeability.

  10. 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.…

  11. 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…

  12. '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.…

  13. 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…

  14. 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…

  15. Media Overload in Instructional Web Pages and the Impact on Learning.

    ERIC Educational Resources Information Center

    Hartley, Kendall W.

    1999-01-01

    Discussion of the use of the Internet to deliver instruction and multimedia opportunities for Web-page design focuses on working memory and its implications for Web-based instruction. Topics include media overload; cognitive load theory; static visual displays; animations; audio; and research questions. (Author/LRW)

  16. 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…

  17. Epigallocatechin-3 gallate prevents cardiac hypertrophy induced by pressure overload in rats.

    PubMed

    Hao, Jia; Kim, Chan-Hyung; Ha, Tae-Sun; Ahn, Hee-Yul

    2007-06-01

    Pressure overload diseases, such as valvular stenosis and systemic hypertension, manifest morphologically in patients as cardiac concentric hypertrophy. Prevention of cardiac remodeling due to increased pressure overload is important to reduce morbidity and mortality. Epigallocatechin-3 gallate (EGCG) is a major bioactive polyphenol present in green tea which has been found to be a nitric oxide-mediated vasorelaxant and to be cardioprotective in myocardial ischemia-reperfusion injury. Therefore, we investigated whether EGCG supplementation could reduce in vivo pressure overloadmediated cardiac hypertrophy. Cardiac hypertrophy was induced by suprarenal transverse abdominal aortic constriction (AC) in rats. Three weeks after AC surgery, heart to body weight ratio increased in the AC group by 34% compared to the sham group. EGCG administration suppressed the load-induced increase in heart weight by 69%. Attenuation of cardiac hypertrophy by EGCG was associated with attenuation of the increase in myocyte cell size and fibrosis induced by aortic constriction. Despite abolition of hypertrophy by EGCG, transstenotic pressure gradients did not change. Echocardiogram revealed that increased left ventricular systolic dimensions and deteriorated systolic function were relieved by EGCG. These results suggest that EGCG prevents the development of left ventricular concentric hypertrophy by pressure overload and may be a useful therapeutic modality to prevent cardiac remodeling in patients with pressure overload myocardial diseases.

  18. 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 §...

  19. 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 §...

  20. 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 §...

  1. The role of magnetic resonance imaging in the evaluation of transfusional iron overload in myelodysplastic syndromes

    PubMed Central

    Petrou, Emmanouil; Mavrogeni, Sophie; Karali, Vasiliki; Kolovou, Genovefa; Kyrtsonis, Marie-Christine; Sfikakis, Petros P.; Panayiotidis, Panayiotis

    2015-01-01

    Myelodysplastic syndromes represent a group of heterogeneous hematopoietic neoplasms derived from an abnormal multipotent progenitor cell, characterized by a hyperproliferative bone marrow, dysplasia of the cellular hemopoietic elements and ineffective erythropoiesis. Anemia is a common finding in myelodysplastic syndrome patients, and blood transfusions are the only therapeutic option in approximately 40% of cases. The most serious side effect of regular blood transfusion is iron overload. Currently, cardiovascular magnetic resonance using T2 is routinely used to identify patients with myocardial iron overload and to guide chelation therapy, tailored to prevent iron toxicity in the heart. This is a major validated non-invasive measure of myocardial iron overloading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters. The indication for iron chelation therapy in myelodysplastic syndrome patients is currently controversial. However, cardiovascular magnetic resonance may offer an excellent non-invasive, diagnostic tool for iron overload assessment in myelodysplastic syndromes. Further studies are needed to establish the precise indications of chelation therapy and the clinical implications of this treatment on survival in myelodysplastic syndromes. PMID:26190429

  2. Investigation of Stress Intensity Factor for Overloaded Holes and Cold-Expanded Holes

    DTIC Science & Technology

    2012-07-01

    analysis of repairs to fuselage skin lap-joints, wing planks and bulkhead frames. More recently he has been involved with structural and mechanical...overload stress max  peak residual hoop stress at hole boundary R radial stress at cold-worked hole T tangential stress at cold-worked hole vm

  3. 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 §...

  4. 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 §...

  5. Cinaciguat prevents the development of pathologic hypertrophy in a rat model of left ventricular pressure overload

    PubMed Central

    Németh, Balázs Tamás; Mátyás, Csaba; Oláh, Attila; Lux, Árpád; Hidi, László; Ruppert, Mihály; Kellermayer, Dalma; Kökény, Gábor; Szabó, Gábor; Merkely, Béla; Radovits, Tamás

    2016-01-01

    Pathologic myocardial hypertrophy develops when the heart is chronically pressure-overloaded. Elevated intracellular cGMP-levels have been reported to prevent the development of pathologic myocardial hypertrophy, therefore we investigated the effects of chronic activation of the cGMP producing enzyme, soluble guanylate cyclase by Cinaciguat in a rat model of pressure overload-induced cardiac hypertrophy. Abdominal aortic banding (AAB) was used to evoke pressure overload-induced cardiac hypertrophy in male Wistar rats. Sham operated animals served as controls. Experimental and control groups were treated with 10 mg/kg/day Cinaciguat (Cin) or placebo (Co) p.o. for six weeks, respectively. Pathologic myocardial hypertrophy was present in the AABCo group following 6 weeks of pressure overload of the heart, evidenced by increased relative heart weight, average cardiomyocyte diameter, collagen content and apoptosis. Cinaciguat did not significantly alter blood pressure, but effectively attenuated all features of pathologic myocardial hypertrophy, and normalized functional changes, such as the increase in contractility following AAB. Our results demonstrate that chronic enhancement of cGMP signalling by pharmacological activation of sGC might be a novel therapeutic approach in the prevention of pathologic myocardial hypertrophy. PMID:27853261

  6. The biomechanical overload of the upper limb: a neglected occupational hazard in animal facility operators.

    PubMed

    Occhionero, Vincenzo; Ghersi, Rinaldo; Prandini, Lucio; Korpinen, Leena; Gobba, Fabriziomaria

    2017-03-01

    Data on biomechanical overload of the upper limb in animal facility operators are currently scanty. We decided to study this risk in a university animal facility. Eleven different tasks performed by operators were identified. For each of them, the biomechanical overload of the upper limb was evaluated by applying 4 different methods frequently used, hypothesising a task duration of 4 and 8 h. Then two 'typical' real working days of the examined facility were reconstructed, and the risk for operators was calculated using the OCRA Index, Checklist and Mini-Checklist. Considering the specific tasks, the results show some difference among methods, but the overall results show an acceptable/slight risk of biomechanical overload of the upper limb in animal facility operators during typical working days. Practitioner Summary: Upper limb biomechanical overload (UL-BO) is a neglected risk in animal facilities. In a university facility, 11 different tasks were identified, and 2 typical working days were analysed. Even if some task at increased risk may exist, during typical working days,  the overall results show that the risk of UL-BO in operators can be considered usually acceptable or, at worst, slight.

  7. Cinaciguat prevents the development of pathologic hypertrophy in a rat model of left ventricular pressure overload.

    PubMed

    Németh, Balázs Tamás; Mátyás, Csaba; Oláh, Attila; Lux, Árpád; Hidi, László; Ruppert, Mihály; Kellermayer, Dalma; Kökény, Gábor; Szabó, Gábor; Merkely, Béla; Radovits, Tamás

    2016-11-17

    Pathologic myocardial hypertrophy develops when the heart is chronically pressure-overloaded. Elevated intracellular cGMP-levels have been reported to prevent the development of pathologic myocardial hypertrophy, therefore we investigated the effects of chronic activation of the cGMP producing enzyme, soluble guanylate cyclase by Cinaciguat in a rat model of pressure overload-induced cardiac hypertrophy. Abdominal aortic banding (AAB) was used to evoke pressure overload-induced cardiac hypertrophy in male Wistar rats. Sham operated animals served as controls. Experimental and control groups were treated with 10 mg/kg/day Cinaciguat (Cin) or placebo (Co) p.o. for six weeks, respectively. Pathologic myocardial hypertrophy was present in the AABCo group following 6 weeks of pressure overload of the heart, evidenced by increased relative heart weight, average cardiomyocyte diameter, collagen content and apoptosis. Cinaciguat did not significantly alter blood pressure, but effectively attenuated all features of pathologic myocardial hypertrophy, and normalized functional changes, such as the increase in contractility following AAB. Our results demonstrate that chronic enhancement of cGMP signalling by pharmacological activation of sGC might be a novel therapeutic approach in the prevention of pathologic myocardial hypertrophy.

  8. 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.

  9. 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... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  10. 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... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  11. 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... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  12. 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... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  13. 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... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  14. 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

    2015-11-02

    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.

  15. Acute Bronchitis

    MedlinePlus

    ... can also cause acute bronchitis. To diagnose acute bronchitis, your health care provider will ask about your symptoms and listen to your breathing. You may also have other tests. Treatments include rest, fluids, and aspirin (for adults) or ...

  16. 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…

  17. Pathogenic Mechanisms Underlying Iron Deficiency and Iron Overload: New Insights for Clinical Application.

    PubMed

    Kotze, M J; van Velden, D P; van Rensburg, S J; Erasmus, R

    2009-08-01

    Iron uptake, utilisation, release and storage occur at the gene level. Individuals with variant forms of genes involved in iron metabolism may have different requirements for iron and are likely to respond differently to the same amount of iron in the diet, a concept termed nutrigenetics. Iron deficiency, iron overload and the anemia of inflammation are the commonest iron-related disorders. While at least four types of hereditary iron overload have been identified to date, our knowledge of the genetic basis and consequences of inherited iron deficiency remain limited. The importance of genetic risk factors in relation to iron overload was highlighted with the identification of the HFE gene in 1996. Deleterious mutations in this gene account for 80-90% of inherited iron overload and are associated with loss of iron homeostasis, alterations in inflammatory responses, oxidative stress and in its most severe form, the disorder hereditary haemochromatosis (HH). Elucidation of the genetic basis of HH has led to rapid clinical benefit through drastic reduction in liver biopsies performed as part of the diagnostic work-up of affected patients. Today, detection of a genetic predisposition in the presence of high serum ferritin and transferrin saturation levels is usually sufficient to diagnose HH, thereby addressing the potential danger of inherited iron overload which starts with the same symptoms as iron deficiency, namely chronic fatigue. This review provides the scientific back-up for application of pathology supported genetic testing, a new test concept that is well placed for optimizing clinical benefit to patients with regard to iron status.

  18. Cardiac iron overload in chronically transfused patients with thalassemia, sickle cell anemia, or myelodysplastic syndrome.

    PubMed

    de Montalembert, Mariane; Ribeil, Jean-Antoine; Brousse, Valentine; Guerci-Bresler, Agnes; Stamatoullas, Aspasia; Vannier, Jean-Pierre; Dumesnil, Cécile; Lahary, Agnès; Touati, Mohamed; Bouabdallah, Krimo; Cavazzana, Marina; Chauzit, Emmanuelle; Baptiste, Amandine; Lefebvre, Thibaud; Puy, Hervé; Elie, Caroline; Karim, Zoubida; Ernst, Olivier; Rose, Christian

    2017-01-01

    The risk and clinical significance of cardiac iron overload due to chronic transfusion varies with the underlying disease. Cardiac iron overload shortens the life expectancy of patients with thalassemia, whereas its effect is unclear in those with myelodysplastic syndromes (MDS). In patients with sickle cell anemia (SCA), iron does not seem to deposit quickly in the heart. Our primary objective was to assess through a multicentric study the prevalence of cardiac iron overload, defined as a cardiovascular magnetic resonance T2*<20 ms, in patients with thalassemia, SCA, or MDS. Patient inclusion criteria were an accurate record of erythrocyte concentrates (ECs) received, a transfusion history >8 ECs in the past year, and age older than 6 years. We included from 9 centers 20 patients with thalassemia, 41 with SCA, and 25 with MDS in 2012-2014. Erythrocytapharesis did not consistently prevent iron overload in patients with SCA. Cardiac iron overload was found in 3 (15%) patients with thalassemia, none with SCA, and 4 (16%) with MDS. The liver iron content (LIC) ranged from 10.4 to 15.2 mg/g dry weight, with no significant differences across groups (P = 0.29). Abnormal T2* was not significantly associated with any of the measures of transfusion or chelation. Ferritin levels showed a strong association with LIC. Non-transferrin-bound iron was high in the thalassemia and MDS groups but low in the SCA group (P<0.001). Hepcidin was low in thalassemia, normal in SCA, and markedly elevated in MDS (P<0.001). Two mechanisms may explain that iron deposition largely spares the heart in SCA: the high level of erythropoiesis recycles the iron and the chronic inflammation retains iron within the macrophages. Thalassemia, in contrast, is characterized by inefficient erythropoiesis, unable to handle free iron. Iron accumulation varies widely in MDS syndromes due to the competing influences of abnormal erythropoiesis, excess iron supply, and inflammation.

  19. 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.

  20. 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.

  1. Cardiac iron overload in chronically transfused patients with thalassemia, sickle cell anemia, or myelodysplastic syndrome

    PubMed Central

    de Montalembert, Mariane; Ribeil, Jean-Antoine; Brousse, Valentine; Guerci-Bresler, Agnes; Stamatoullas, Aspasia; Vannier, Jean-Pierre; Dumesnil, Cécile; Lahary, Agnès; Touati, Mohamed; Bouabdallah, Krimo; Cavazzana, Marina; Chauzit, Emmanuelle; Baptiste, Amandine; Lefebvre, Thibaud; Puy, Hervé; Elie, Caroline

    2017-01-01

    The risk and clinical significance of cardiac iron overload due to chronic transfusion varies with the underlying disease. Cardiac iron overload shortens the life expectancy of patients with thalassemia, whereas its effect is unclear in those with myelodysplastic syndromes (MDS). In patients with sickle cell anemia (SCA), iron does not seem to deposit quickly in the heart. Our primary objective was to assess through a multicentric study the prevalence of cardiac iron overload, defined as a cardiovascular magnetic resonance T2*<20 ms, in patients with thalassemia, SCA, or MDS. Patient inclusion criteria were an accurate record of erythrocyte concentrates (ECs) received, a transfusion history >8 ECs in the past year, and age older than 6 years. We included from 9 centers 20 patients with thalassemia, 41 with SCA, and 25 with MDS in 2012-2014. Erythrocytapharesis did not consistently prevent iron overload in patients with SCA. Cardiac iron overload was found in 3 (15%) patients with thalassemia, none with SCA, and 4 (16%) with MDS. The liver iron content (LIC) ranged from 10.4 to 15.2 mg/g dry weight, with no significant differences across groups (P = 0.29). Abnormal T2* was not significantly associated with any of the measures of transfusion or chelation. Ferritin levels showed a strong association with LIC. Non-transferrin-bound iron was high in the thalassemia and MDS groups but low in the SCA group (P<0.001). Hepcidin was low in thalassemia, normal in SCA, and markedly elevated in MDS (P<0.001). Two mechanisms may explain that iron deposition largely spares the heart in SCA: the high level of erythropoiesis recycles the iron and the chronic inflammation retains iron within the macrophages. Thalassemia, in contrast, is characterized by inefficient erythropoiesis, unable to handle free iron. Iron accumulation varies widely in MDS syndromes due to the competing influences of abnormal erythropoiesis, excess iron supply, and inflammation. PMID:28257476

  2. Effects of digoxin on cardiac iron content in rat model of iron overload

    PubMed Central

    Nasri, Hamid Reza; Shahouzehi, Beydolah; Masoumi-Ardakani, Yaser; Iranpour, Maryam

    2016-01-01

    BACKGROUND Plasma iron excess can lead to iron accumulation in heart, kidney and liver. Heart failure is a clinical widespread syndrome. In thalassemia, iron overload cardiomyopathy is caused by iron accumulation in the heart that leads to cardiac damage and heart failure. Digoxin increases the intracellular sodium concentration by inhibition of Na+/K+-ATPase that affects Na+/Ca2+ exchanger (NCX), which raises intracellular calcium and thus attenuates heart failure. The mechanism of iron uptake into cardiomyocytes is not exactly understood. METHODS We assessed the effect of different concentrations of digoxin on cardiac iron content in rat model of iron overload. Digoxin had been administrated intraperitoneally (IP) for one week before main study began to assure increased digoxin levels. Group 1 received four IP injections of iron-dextran (12.5mg/100g body weight) every 5 days evenly distributed over 20 days. Groups 2-4 received 0.5, 1 and 5 mg/kg/day IP digoxin, respectively. Last three groups 5-7 received iron-dextran as group 1 and digoxin concentrations 0.5, 1 and 5 mg/kg/day, respectively. RESULTS Cardiac iron contents were significantly higher in iron overload groups that received different concentrations (0.5, 1 and 5 mg/kg/day) of digoxin than their counterparts in control groups and this pattern was also observed in pathology assessment. CONCLUSION It seems that digoxin plays an important role in iron transport into heart in iron overload state but exact mechanism of this phenomenon is not clear. L-type Ca2+ channels are good candidates that probably could be involved in iron accumulation in cardiomyocytes. Thus it would be better to reconsider digoxin administration in thalassemia and iron overload conditions. PMID:28149313

  3. Aberrant fecal flora observed in guinea pigs with pressure overload is mitigated in animals receiving vagus nerve stimulation therapy.

    PubMed

    Phillips Campbell, Regenia B; Duffourc, Michelle M; Schoborg, Robert V; Xu, Yanji; Liu, Xinyi; KenKnight, Bruce H; Beaumont, Eric

    2016-10-01

    Altered gut microbial diversity has been associated with several chronic disease states, including heart failure. Stimulation of the vagus nerve, which innervates the heart and abdominal organs, is proving to be an effective therapeutic in heart failure. We hypothesized that cervical vagus nerve stimulation (VNS) could alter fecal flora and prevent aberrations observed in fecal samples from heart failure animals. To determine whether microbial abundances were altered by pressure overload (PO), leading to heart failure and VNS therapy, a VNS pulse generator was implanted with a stimulus lead on either the left or right vagus nerve before creation of PO by aortic constriction. Animals received intermittent, open-loop stimulation or sham treatment, and their heart function was monitored by echocardiography. Left ventricular end-systolic and diastolic volumes, as well as cardiac output, were impaired in PO animals compared with baseline. VNS mitigated these effects. Metagenetic analysis was then performed using 16S rRNA sequencing to identify bacterial genera present in fecal samples. The abundance of 10 genera was significantly altered by PO, 8 of which were mitigated in animals receiving either left- or right-sided VNS. Metatranscriptomics analyses indicate that the abundance of genera that express genes associated with ATP-binding cassette transport and amino sugar/nitrogen metabolism was significantly changed following PO. These gut flora changes were not observed in PO animals subjected to VNS. These data suggest that VNS prevents aberrant gut flora following PO, which could contribute to its beneficial effects in heart failure patients.

  4. 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.

  5. Safety considerations in large-volume lipoplasty.

    PubMed

    Giese, S Y

    2001-11-01

    Proper patient selection, diligent fluid management, and attention to body temperature are important safety considerations in large-volume lipoplasty (LVL). Complications related to fluid overload, lidocaine toxicity, coagulopathies, and lengthy combined surgical procedures are preventable and not directly linked to LVL technique. Benefits as well as morbidity and mortality from LVL can be weighed against risk factors such as obesity, a prediabetic condition, and/or adverse effects of weight-loss medications. The author describes how she incorporates safeguards into her LVL procedures. (Aesthetic Surg J 2001;21:545-548.).

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. A comparison of overload behaviour for some sub 2 μm totally porous and sub 3 μm shell particle columns with ionised solutes.

    PubMed

    Fallas, Morgane M; Buckenmaier, Stephan M C; McCalley, David V

    2012-04-27

    The overloading performance of some 2.7 μm shell and sub 2 μm totally porous columns, including one pair manufactured from similar materials with similar bonding chemistries, was compared using strongly acidic and basic probe compounds. In general, the capacity of shell particles was not greatly reduced, despite containing a smaller porous volume. Nevertheless, at low pH, both types of column were overloaded by only small concentrations of ionised solute. Considerable improvement could be gained by increasing the buffer concentration, although sensitivity in mass spectrometric detection may be compromised. The capacity of columns of different internal diameter may not be directly compared merely by scaling the injection volumes, as it is possible that the sample is not homogeneously distributed across the column radius, especially in larger diameter columns, where the sample may travel preferentially through a central core of the packing. A totally porous charged surface hybrid phase gave much improved loading properties of the basic probe in low ionic strength mobile phases such as formic acid, often used in mass spectrometry. However, its relative advantage over conventional phases was reduced as the mobile phase ionic strength was increased. Furthermore, acidic compounds may give tailing on this phase. At pH 7, all columns tested showed evidence of interaction with ionised silanols; peak shapes improved as the buffer concentration was increased. Column efficiency first increased and then decreased as solute concentration was increased at constant buffer concentration, which can be attributed to the decreasing proportion of solute molecules retained by the ion exchange process.

  12. Iron overload induced death of osteoblasts in vitro: involvement of the mitochondrial apoptotic pathway

    PubMed Central

    Dai, Zhipeng; Yang, Jingjing; Zheng, Jin

    2016-01-01

    Background Iron overload is recognized as a new pathogenfor osteoporosis. Various studies demonstrated that iron overload could induce apoptosis in osteoblasts and osteoporosis in vivo. However, the exact molecular mechanisms involved in the iron overload-mediated induction of apoptosis in osteoblasts has not been explored. Purpose In this study, we attempted to determine whether the mitochondrial apoptotic pathway is involved in iron-induced osteoblastic cell death and to investigate the beneficial effect of N-acetyl-cysteine (NAC) in iron-induced cytotoxicity. Methods The MC3T3-E1 osteoblastic cell line was treated with various concentrations of ferric ion in the absence or presence of NAC, and intracellular iron, cell viability, reactive oxygen species, functionand morphology changes of mitochondria and mitochondrial apoptosis related key indicators were detected by commercial kits. In addition, to further explain potential mechanisms underlying iron overload-related osteoporosis, we also assessed cell viability, apoptosis, and osteogenic differentiation potential in bone marrow-derived mesenchymal stemcells(MSCs) by commercial kits. Results Ferric ion demonstrated concentration-dependent cytotoxic effects on osteoblasts. After incubation with iron, an elevation of intracelluar labile iron levels and a concomitant over-generation of reactive oxygen species (ROS) were detected by flow cytometry in osteoblasts. Nox4 (NADPH oxidase 4), an important ROS producer, was also evaluated by western blot. Apoptosis, which was evaluated by Annexin V/propidium iodide staining, Hoechst 33258 staining, and the activation of caspase-3, was detected after exposure to iron. Iron contributed to the permeabilizatio of mitochondria, leading to the release of cytochrome C (cyto C), which, in turn, induced mitochondrial apoptosis in osteoblasts via activation of Caspase-3, up-regulation of Bax, and down-regulation of Bcl-2. NAC could reverse iron-mediated mitochondrial dysfunction and

  13. [The relationship between the heart and the kidney in acute heart failure: doubts of the cardiologist and the nephrologist's point of view].

    PubMed

    Di Tano, Giuseppe; Misuraca, Gianfranco; Ronco, Claudio; Zoccali, Carmine; Frigerio, Maria

    2012-04-01

    The pathophysiological interactions that link the heart and kidney in heart failure are multiple and complex. This issue constitutes one of the most vexing and difficult challenges facing cardiologists. In the setting of acute decompensated heart failure, worsening renal function has traditionally been directly associated with poor clinical prognosis and complicates treatment. In the last years, many reports suggest that worsening renal failure may represent the final common pathway of several mechanistically distinct processes, with different prognostic implications. In the clinical scenario, the clinical significance of transient worsening of renal function may be different as compared with irreversible or progressive renal failure. In addition, it can represent a relatively normal response to treatment-induced physiological derangements such as a reduction in renal perfusion and/or intravascular volume. We here focus on these highlights, with special reference to the diagnostic criteria of renal dysfunction and the management of fluid overload. Two expert nephrologists were asked to answer a few important clinical questions: how should renal dysfunction be recognized and monitored? Are there therapies to counteract it and when, and more importantly, for whom should be applied? Their answers serve as touchstones for cardiologists to provide better individualized care for their patients with acute heart failure. Only a multidisciplinary and collaborative management of cardio-renal interactions will help to mitigate the difficult day-to-day clinical practice and improve our understanding of this condition through a concerted and constructive approach.

  14. Evaluation and Management of Critically Ill Children with Acute Kidney Injury

    PubMed Central

    Askenazi, David

    2012-01-01

    Purpose of the review Acute kidney injury (AKI) has replaced the term acute renal failure and new definitions have been proposed to allow earlier detection. Recent epidemiology data show that the etiology of pediatric AKI has changed and the indications for initiation of renal replacement therapy have evolved. This review will highlight recent studies on the diagnosis of AKI, review the differential diagnosis, highlight the importance of cumulative fluid overload and provide key management strategies for the pediatric patient with AKI. Recent findings Over the last decade serum creatinine based categorical definitions of AKI have been accepted and improve our ability to detect AKI early in the disease process. Evidence based modifications of these definitions have occurred. Higher degree of fluid overload portends poor outcomes in critically ill patients. Significant improvements in our understanding of the pathophysiology of glomerular/vascular causes of AKI have occurred. Summary Categorical definitions of AKI have shown that higher that AKI portends poor outcomes even when adjustment of severity of illness and other confounders. As higher degrees of fluid overload are independently associated with poor outcomes, strategies to prevent and/or treat fluid overload are likely to improve outcomes. PMID:21191296

  15. Neutron and X-ray Microbeam Diffraction Studies around a Fatigue-Crack Tip after Overload

    SciTech Connect

    Lee, Sooyeol; Barabash, Rozaliya; Chung, Jin-Seok; Liaw, Peter K; Choo, Hahn; Sun, Yinan; Fan, C; Li, Li; Brown, Donald; Ice, Gene E

    2008-01-01

    An in-situ neutron diffraction technique was used to investigate the lattice-strain distributions and plastic deformation around a crack tip after overload. The lattice-strain profiles around a crack tip were measured as a function of the applied load during the tensile loading cycles after overload. Dislocation densities calculated from the diffraction peak broadening were presented as a function of the distance from the crack tip. Furthermore, the crystallographic orientation variations were examined near a crack tip using polychromatic X-ray microdiffraction combined with differential aperture microscopy. Crystallographic tilts are considerably observed beneath the surface around a crack tip, and these are consistent with the high dislocation densities near the crack tip measured by neutron peak broadening.

  16. A Review on Iron Chelators in Treatment of Iron Overload Syndromes

    PubMed Central

    Mobarra, Naser; Shanaki, Mehrnoosh; Ehteram, Hassan; Nasiri, Hajar; Sahmani, Mehdi; Saeidi, Mohsen; Goudarzi, Mehdi; Pourkarim, Hoda; Azad, Mehdi

    2016-01-01

    Iron chelation therapy is used to reduce iron overload development due to its deposition in various organs such as liver and heart after regular transfusion. In this review, different iron chelators implicated in treatment of iron overload in various clinical conditions have been evaluated using more up-to-date studies focusing on these therapeutic agents. Deferoxamine, Deferiprone and Deferasirox are the most important specific US FDA-approved iron chelators. Each of these chelators has their own advantages and disadvantages, various target diseases, levels of deposited iron and clinical symptoms of the afflicted patients which may affect their selection as the best modality. Taken together, in many clinical disorders, choosing a standard chelator does not have an accurate index which requires further clarifications. The aim of this review is to introduce and compare the different iron chelators regarding their advantages and disadvantages, usage dose and specific applications. PMID:27928480

  17. 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).

  18. 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).

  19. Political skill: an antidote in the role overload-strain relationship.

    PubMed

    Perrewé, Pamela L; Zellars, Kelly L; Rossi, Ana Maria; Ferris, Gerald R; Kacmar, Charles J; Liu, Yongmei; Zinko, Robert; Hochwarter, Wayne A

    2005-07-01

    Political skill is characterized by social perceptiveness and the ability to adjust one's behavior to different and changing situational needs to influence others. The authors argue that politically skilled individuals enjoy a sense of personal security that allows them to perceive interpersonal control over the process and outcomes of interpersonal interactions within organizations. The authors examine the buffering effects of political skill on the perceived role overload-strain relationship, with strain operationalized as job tension, job (dis)satisfaction, and general anxiety. Results support the hypothesized moderating effects of political skill such that greater political skill reduces the negative effects of role overload on all types of strain. The contributions and limitations of the study are discussed, as are directions for future research.

  20. Synthesis of 6-amino-1,4-dihydropyridines that prevent calcium overload and neuronal death.

    PubMed

    León, Rafael; de Los Ríos, Cristóbal; Marco-Contelles, José; López, Manuela G; García, Antonio G; Villarroya, Mercedes

    2008-03-01

    The synthesis and pharmacology of 6-amino-1,4-dihydropyridines, such as ethyl 6-amino-4-aryl-5-cyano-1,4-dihydro-2-methyl-3-pyridinecarboxylic acids (3-16) and 2-amino-4-aryl-7,7-dimethyl-5-oxo-1,4,5,6,7,8-hexahydro-3-quinolinenitriles (17-21) are described. Compounds 18 and 21, at the concentration of 0.3 microM, proved to be the best blockers of the [Ca(2+)] overload induced by depolarization with high [K(+)] of SH-SY5Y neuroblastoma cells, with values of 63.8% and 50.4%, respectively. Most of the compounds induced a remarkable neuroprotective effect against toxicity caused by high [K(+)]-elicited [Ca(2+)] overload, and against H(2)O(2)-generated free radicals, in SH-SY5Y cells.

  1. 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

  2. Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers.

    PubMed

    Concha, Claudia; Carretta, María Daniella; Alarcón, Pablo; Conejeros, Ivan; Gallardo, Diego; Hidalgo, Alejandra Isabel; Tadich, Nestor; Cáceres, Dante Daniel; Hidalgo, María Angélica; Burgos, Rafael Agustín

    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.

  3. The Influence of Fluid Overload on the Length of Mechanical Ventilation in Pediatric Congenital Heart Surgery.

    PubMed

    Sampaio, Tatiana Z A L; O'Hearn, Katie; Reddy, Deepti; Menon, Kusum

    2015-12-01

    Fluid overload and prolonged mechanical ventilation lead to worse outcomes in critically ill children. However, the association between these variables in children following congenital heart surgery is unknown. The objectives of this study were to describe the association between fluid overload and duration of mechanical ventilation, oxygen requirement and radiologic findings of pulmonary and chest wall edema. This study is a retrospective chart review of patients who underwent congenital heart surgery between June 2010 and December 2013. Univariate and multivariate associations between maximum cumulative fluid balance and length of mechanical ventilation and OI were tested using the Spearman correlation test and multiple linear regression models, respectively. There were 85 eligible patients. Maximum cumulative fluid balance was associated with duration of mechanical ventilation (adjusted analysis beta coefficient = 0.53, CI 0.38-0.66, P < 0.001), length of stay in the pediatric intensive care unit (Spearman's correlation = 0.45, P < 0.001), and presence of chest wall edema and pleural effusions on chest radiograph (Mann-Whitney test, P = 0.003). Amount of red blood cells transfused and use of nitric oxide were independently associated with increased duration of mechanical ventilation (P = 0.012 and 0.014, respectively). Fluid overload is associated with prolonged duration of mechanical ventilation and PICU length of stay after congenital heart surgery. Fluid overload was also associated with physiological markers of respiratory restriction. A randomized controlled trial of a restrictive versus liberal fluid replacement strategy is necessary in this patient population, but in the meantime, accumulating observational evidence suggests that cautious use of fluid in the postoperative care may be warranted.

  4. Ferritin in the Serum of Normal Subjects and Patients with Iron Deficiency and Iron Overload

    PubMed Central

    Jacobs, A.; Miller, F.; Worwood, M.; Beamish, M. R.; Wardrop, C. A.

    1972-01-01

    The concentration of ferritin in serum gives a quantitative measure of the amount of storage iron in normal subjects and those with iron deficiency or overload. The mean level in normal men is 69 ng/ml, compared with 35 ng/ml in normal women. A concentration below 10 ng/ml is associated with a low transferrin saturation and iron-deficient erythropoiesis. PMID:5082548

  5. The hepcidin-ferroportin system as a therapeutic target in anemias and iron overload disorders.

    PubMed

    Ganz, Tomas; Nemeth, Elizabeta

    2011-01-01

    The review summarizes the current understanding of the role of hepcidin and ferroportin in normal iron homeostasis and its disorders. The various approaches to therapeutic targeting of hepcidin and ferroportin in iron-overload disorders (mainly hereditary hemochromatosis and β-thalassemia) and iron-restrictive anemias (anemias associated with infections, inflammatory disorders, and certain malignancies, anemia of chronic kidney diseases, and iron-refractory iron-deficiency anemia) are also discussed.

  6. Implementing Filters to Identify and Prioritize Industrial Base Risk: Rules of Thumb to Reduce Cognitive Overload

    DTIC Science & Technology

    2015-04-30

    Thumb to Reduce Cognitive Overload Sally Sleeper, ODASD[M&IBP] John F. Starns, Northrop Grumman Published April 30, 2015 Disclaimer: The views...federal government. Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to...and completing and reviewing the collection of information . Send comments regarding this burden estimate or any other aspect of this collection of

  7. 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

  8. [Evaluation of risks of biomechanical overload of the upper limb in physical kinesis therapists].

    PubMed

    Lupi, A; Martinelli, R; Tobia, L; Paoletti, A

    2005-01-01

    Physical therapists are at risk for work-related musculoskeletal disorders (WMSDs). Contributing risk factors are job-task, mental stress and biomechanical overload, due to fixed and incorrect postures of neck, upper limbs and back. The purpose of this study was to investigate, by questionnaire and the use of muscle superficial EMG recording and analysis, the workload in the physical therapist activity, in order to provide suitable preventive measures.

  9. Pulmonary iron overload in thalassemia major presenting as small airway disease.

    PubMed

    Ooi, G C; Khong, P L; Lam, W K; Trendell-Smith, N J; Tsang, K W T

    2002-01-01

    Lung function abnormalities that are associated with thalassemia major are variable with etiology that is yet undetermined. Some studies have suggested that pulmonary iron deposition is a probable cause for these lung defects although there has been no antemortem histopathological and radiological evidence for this. We report a case of thalassemia major with biopsy-proven pulmonary iron overload, in which thoracic high-resolution computed tomography revealed a morphological-functional correlation consistent with small airway disease.

  10. Mononuclear Phagocytes Are Dispensable for Cardiac Remodeling in Established Pressure-Overload Heart Failure

    PubMed Central

    Patel, Bindiya; Ismahil, Mohamed Ameen; Hamid, Tariq; Bansal, Shyam S.; Prabhu, Sumanth D.

    2017-01-01

    Background Although cardiac and splenic mononuclear phagocytes (MPs), i.e., monocytes, macrophages and dendritic cells (DCs), are key contributors to cardiac remodeling after myocardial infarction, their role in pressure-overload remodeling is unclear. We tested the hypothesis that these immune cells are required for the progression of remodeling in pressure-overload heart failure (HF), and that MP depletion would ameliorate remodeling. Methods and Results C57BL/6 mice were subjected to transverse aortic constriction (TAC) or sham operation, and assessed for alterations in MPs. As compared with sham, TAC mice exhibited expansion of circulating LyC6hi monocytes and pro-inflammatory CD206− cardiac macrophages early (1 w) after pressure-overload, prior to significant hypertrophy and systolic dysfunction, with subsequent resolution during chronic HF. In contrast, classical DCs were expanded in the heart in a biphasic manner, with peaks both early, analogous to macrophages, and late (8 w), during established HF. There was no significant expansion of circulating DCs, or Ly6C+ monocytes and DCs in the spleen. Periodic systemic MP depletion from 2 to 16 w after TAC in macrophage Fas-induced apoptosis (MaFIA) transgenic mice did not alter cardiac remodeling progression, nor did splenectomy in mice with established HF after TAC. Lastly, adoptive transfer of splenocytes from TAC HF mice into naïve recipients did not induce immediate or long-term cardiac dysfunction in recipient mice. Conclusions Mononuclear phagocytes populations expand in a phasic manner in the heart during pressure-overload. However, they are dispensable for the progression of remodeling and failure once significant hypertrophy is evident and blood monocytosis has normalized. PMID:28125666

  11. MCT8 is Downregulated by Short Time Iodine Overload in the Thyroid Gland of Rats.

    PubMed

    de Souza, E C L; Dias, G R M; Cardoso, R C; Lima, L P; Fortunato, R S; Visser, T J; Vaisman, M; Ferreira, A C F; Carvalho, D P

    2015-11-01

    Wolff-Chaikoff effect is characterized by the blockade of thyroid hormone synthesis and secretion due to iodine overload. However, the regulation of monocarboxylate transporter 8 during Wolff-Chaikoff effect and its possible role in the rapid reduction of T4 secretion by the thyroid gland remains unclear. Patients with monocarboxylate transporter 8 gene loss-of-function mutations and monocarboxylate transporter 8 knockout mice were shown to have decreased serum T4 levels, indicating that monocarboxylate transporter 8 could be involved in the secretion of thyroid hormones from the thyroid gland. Herein, we aimed to evaluate the regulation of monocarboxylate transporter 8 during the Wolff-Chaikoff effect and the escape from iodine overload, besides the importance of iodine organification for this regulation. Monocarboxylate transporter 8 mRNA and protein levels significantly decreased after 1 day of NaI administration to rats, together with decreased serum T4; while no alteration was observed in LAT2 expression. Moreover, both monocarboxylate transporter 8 expression and serum T4 was restored after 6 days of NaI. The inhibition of thyroperoxidase activity by methimazole prevented the inhibitory effect of NaI on thyroid monocarboxylate transporter 8 expression, suggesting that an active thyroperoxidase is necessary for MCT8 downregulation by iodine overload, similarly to other thyroid markers, such as sodium iodide symporter. Therefore, we conclude that thyroid monocarboxylate transporter 8 expression is downregulated during iodine overload and that the normalization of its expression parallels the escape phenomenon. These data suggest a possible role for monocarboxylate transporter 8 in the changes of thyroid hormones secretion during the Wolff-Chaikoff effect and escape.

  12. Continuing treatment with Salvia miltiorrhiza injection attenuates myocardial fibrosis in chronic iron-overloaded mice.

    PubMed

    Zhang, Ying; Wang, Hao; Cui, Lijing; Zhang, Yuanyuan; Liu, Yang; Chu, Xi; Liu, Zhenyi; Zhang, Jianping; Chu, Li

    2015-01-01

    Iron overload cardiomyopathy results from iron accumulation in the myocardium that is closely linked to iron-mediated myocardial fibrosis. Salvia miltiorrhiza (SM, also known as Danshen), a traditional Chinese medicinal herb, has been widely used for hundreds of years to treat cardiovascular diseases. Here, we investigated the effect and potential mechanism of SM on myocardial fibrosis induced by chronic iron overload (CIO) in mice. Kunming male mice (8 weeks old) were randomized to six groups of 10 animals each: control (CONT), CIO, low-dose SM (L-SM), high-dose SM (H-SM), verapamil (VRP) and deferoxamine (DFO) groups. Normal saline was injected in the CONT group. Mice in the other five groups were treated with iron dextran at 50 mg/kg per day intraperitoneally for 7 weeks, and those in the latter four groups also received corresponding daily treatments, including 3 g/kg or 6 g/kg of SM, 100 mg/kg of VRP, or 100 mg/kg of DFO. The iron deposition was estimated histologically using Prussian blue staining. Myocardial fibrosis was determined by Masson's trichrome staining and hydroxyproline (Hyp) quantitative assay. Superoxide dismutase (SOD) activity, malondialdehyde (MDA) content and protein expression levels of type I collagen (COL I), type I collagen (COL III), transforming growth factor-β1 (TGF-β1) and matrix metalloproteinase-9 (MMP-9) were analyzed to investigate the mechanisms underlying the effects of SM against iron-overloaded fibrosis. Treatment of chronic iron-overloaded mice with SM dose-dependently reduced iron deposition levels, fibrotic area percentage, Hyp content, expression levels of COL I and COL III, as well as upregulated the expression of TGF- β1 and MMP-9 proteins in the heart. Moreover, SM treatment decreased MDA content and increased SOD activity. In conclusion, SM exerted activities against cardiac fibrosis induced by CIO, which may be attributed to its inhibition of iron deposition, as well as collagen metabolism and oxidative stress.

  13. [Longitudinal study of a population exposed to risk of biomechanical overload of the upper limb].

    PubMed

    Martmelli, R; Tobia, L; Lupi, A; Monaco, M; Capitano, T; Ponzi, I; Paoletti, A

    2005-01-01

    One of the most important factors of the work-related musculoskeletal disorders of the upper extremities (WMSDs) is the biomechanical overload. The purpose of this study is to evaluate the possibility of the worker fitting to the job, to decrease the upper limb repetitive stress. In order to this aim, we have collected and compared, in different controls at the distance of two years, the clinical-anamnestic and instrumental data of a cohort of workers in a car industry.

  14. Effect of iron overload on exercise capacity in thalassemic patients with heart failure.

    PubMed

    Mavrogeni, Sophie; Gotsis, Efstathios; Verganelakis, Dimitrios; Berdousis, Eleni; Dritsas, Athanasios; Kolovou, Genovefa; Toulas, Panagiotis; Ladis, Vassilios

    2009-12-01

    In b-thalassemia, myocardial iron overload contributes to heart failure, despite chelation treatment. We hypothesized that myocardial T2*, an index of iron overload, influences patients' physical activity. We assessed a thalassemic population by both cardiovascular magnetic resonance imaging (CMR) and ergospirometry test. Sixty-six thalassemic patients aged 27 (19-40) years, 30 without (NHF) and 36 with heart failure (HF), were studied. Cardiac T2* and left ventricular ejection fraction (LVEF) were evaluated using a 1.5 T system. VO(2max), AT, Mets and duration of exercise by ergospirometry were also assessed. Myocardial T2* was lower in HF compared to NHF patients (14.7 +/- 6.6 vs. 39 +/- 2 ms, P < 0.001). LVEDV and LVESV were higher in HF group compared to NHF patients (139.9 +/- 16.3 vs. 124.6 +/- 20.86 ml, P < 0.01 and 94.9 +/- 24 vs. 38.3 +/- 10.1 ml, P < 0.001, respectively). Additionally, LVEF in HF was lower compared to NHF patients (21.3 +/- 6.1% vs. 69.6 +/- 3.7, P < 0.001, respectively). All exercise parameters were lower in HF compared to NHF patients (P < 0.001). Patients within the HF group were additionally analyzed according to T2* values (<10 ms). HF patients with T2* < 10 ms (n = 13) were considered as high iron overloaded (HF-H) and the rest of them (n = 23) as (HF-L). Although LVEDV, LVESV, LVEF were similar in the two subgroups, the exercise parameters were significantly lower in the HF-H group (P < 0.001). Heart T2* correlated with all exercise parameters (P < 0.001). HF thalassemic patients have reduced exercise indexes compared to non HF. Myocardial iron overload, expressed as T2*, has a direct influence on exercise capacity, independent of LV ejection fraction and functional class.

  15. Thymoquinone, a bioactive component of Nigella sativa, normalizes insulin secretion from pancreatic β-cells under glucose overload via regulation of malonyl-CoA

    PubMed Central

    Gray, Joshua P.; Zayasbazan Burgos, Delaine; Yuan, Tao; Seeram, Navindra; Rebar, Rebecca; Follmer, Rebecca

    2015-01-01

    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

  16. Transcriptional activation of LON Gene by a new form of mitochondrial stress: A role for the nuclear respiratory factor 2 in StAR overload response (SOR).

    PubMed

    Bahat, Assaf; Perlberg, Shira; Melamed-Book, Naomi; Isaac, Sara; Eden, Amir; Lauria, Ines; Langer, Thomas; Orly, Joseph

    2015-06-15

    High output of steroid hormone synthesis in steroidogenic cells of the adrenal cortex and the gonads requires the expression of the steroidogenic acute regulatory protein (StAR) that facilitates cholesterol mobilization to the mitochondrial inner membrane where the CYP11A1/P450scc enzyme complex converts the sterol to the first steroid. Earlier studies have shown that StAR is active while pausing on the cytosolic face of the outer mitochondrial membrane while subsequent import of the protein into the matrix terminates the cholesterol mobilization activity. Consequently, during repeated activity cycles, high level of post-active StAR accumulates in the mitochondrial matrix. To prevent functional damage due to such protein overload effect, StAR is degraded by a sequence of three to four ATP-dependent proteases of the mitochondria protein quality control system, including LON and the m-AAA membranous proteases AFG3L2 and SPG7/paraplegin. Furthermore, StAR expression in both peri-ovulatory ovarian cells, or under ectopic expression in cell line models, results in up to 3-fold enrichment of the mitochondrial proteases and their transcripts. We named this novel form of mitochondrial stress as StAR overload response (SOR). To better understand the SOR mechanism at the transcriptional level we analyzed first the unexplored properties of the proximal promoter of the LON gene. Our findings suggest that the human nuclear respiratory factor 2 (NRF-2), also known as GA binding protein (GABP), is responsible for 88% of the proximal promoter activity, including the observed increase of transcription in the presence of StAR. Further studies are expected to reveal if common transcriptional determinants coordinate the SOR induced transcription of all the genes encoding the SOR proteases.

  17. 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.

  18. 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

  19. Iron does not cause arrhythmias in the guinea pig model of transfusional iron overload.

    PubMed

    Kaiser, Lana; Davis, John; Patterson, Jon; Boyd, Ryan F; Olivier, N Bari; Bohart, George; Schwartz, Kenneth A

    2007-08-01

    Cardiac events, including heart failure and arrhythmias, are the leading cause of death in patients with beta thalassemia. Although cardiac arrhythmias in humans are believed to result from iron overload, excluding confounding factors in the human population is difficult. The goal of the current study was to determine whether cardiac arrhythmias occurred in the guinea pig model of secondary iron overload. Electrocardiograms were recorded by using surgically implanted telemetry devices in guinea pigs loaded intraperitoneally with iron dextran (test animals) or dextran alone (controls). Loading occurred over approximately 6 wk. Electrocardiograms were recorded for 1 wk prior to loading, throughout loading, and for approximately 4 wk after loading was complete. Cardiac and liver iron concentrations were significantly increased in the iron-loaded animals compared with controls and were in the range of those reported for humans with thalassemia. Arrhythmias were rare in both iron-loaded and control guinea pigs. No life-threatening arrhythmias were detected in either group. These data suggest that iron alone may be insufficient to cause cardiac arrhythmias in the iron-loaded guinea pig model and that arrhythmias detected in human patients with iron overload may be the result of a complex interplay of factors.

  20. Clinical Impact and Cellular Mechanisms of Iron Overload-Associated Bone Loss

    PubMed Central

    Jeney, Viktória

    2017-01-01

    Diseases/conditions with diverse etiology, such as hemoglobinopathies, hereditary hemochromatosis and menopause, could lead to chronic iron accumulation. This condition is frequently associated with a bone phenotype; characterized by low bone mass, osteoporosis/osteopenia, altered microarchitecture and biomechanics, and increased incidence of fractures. Osteoporotic bone phenotype constitutes a major complication in patients with iron overload. The purpose of this review is to summarize what we have learnt about iron overload-associated bone loss from clinical studies and animal models. Bone is a metabolically active tissue that undergoes continuous remodeling with the involvement of osteoclasts that resorb mineralized bone, and osteoblasts that form new bone. Growing evidence suggests that both increased bone resorption and decreased bone formation are involved in the pathological bone-loss in iron overload conditions. We will discuss the cellular and molecular mechanisms that are involved in this detrimental process. Fuller understanding of this complex mechanism may lead to the development of improved therapeutics meant to interrupt the pathologic effects of excess iron on bone. PMID:28270766

  1. 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.

  2. Investigation on internal flow of draft tube at overload condition in low specific speed Francis turbine

    NASA Astrophysics Data System (ADS)

    Tamura, Yuta; Tani, Kiyohito

    2016-11-01

    The cavitating vortices causes the unsteady phenomena like the pressure fluctuation, the noise and the vibration in the draft tube at the overload condition which is the far operating point from the design point. Because the full load was normally near the design point, there were few troubles due to cavitating vortices at the full load. Today, however, the design point is sometimes set to lower load to achieve the high efficiency from the partial load to the full load in low specific speed Francis turbines, which have good performance to a change in a discharge. Then, the full load is relatively further from the design point. As the result, the potential for the cavitating vortices at the full load is increased. To control of the unsteady phenomena at the full load, the study focused on the cavitating vortices at the overload condition is important. This paper presents the unsteady behavior of the cavitating vortices at the overload condition with the scaled model of specific speed NQE=0.083. On the experimental approach, the pressure pulsation in the upper draft tube was measured and the unsteady behavior of cavitating vortices was taken movies with a high speed camera. On the numerical approach, Computational Fluid Dynamics (CFD) adopting a two-phase unsteady analysis was carried out. The pressure fluctuation and the velocity distribution of two runners, an original and a newly designed, were compared.

  3. The Design and Optimization of a Highly Sensitive and Overload-Resistant Piezoresistive Pressure Sensor.

    PubMed

    Meng, Xiawei; Zhao, Yulong

    2016-03-09

    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.

  4. Cholesterol overloading leads to hepatic L02 cell damage through activation of the unfolded protein response.

    PubMed

    Li, Qi; Liu, Zhiguo; Guo, Jianli; Chen, Jiangyuan; Yang, Pu; Tian, Jun; Sun, Jun; Zong, Yiqiang; Qu, Shen

    2009-10-01

    Reported data indicate that cholesterol loading in the liver can cause hepatic injury. To explore the possible mechanisms of cell damage resulting from cholesterol overloading in hepatocytes, cell apoptosis, the unfolded protein response (UPR) and the correlation between them were assessed in the cholesterol-overloaded normal human hepatic cell line L02. L02 cells were incubated with 200 microg/ ml of low density lipoprotein (LDL) for 24 h with or without 20 microg/ml 58035, an inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT). In the LDL+58035 group, the intracellular cholesterol level was dramatically increased, which was measured by an enzymatic combined high performance liquid chromatography assay. Expression of immunoglobulin-binding protein, X-box binding protein 1, activating transcription factor 6, activating transcription factor 4, CCAAT/enhancer-binding protein homologous protein-10, markers of endoplasmic reticulum stress (ERS)/ UPR, were up-regulated as determined using reverse transcription-polymerase chain reaction (RT-PCR) or Western blot analysis. The rate of cell apoptic death increased 21.3+/-2.4%. Meanwhile, the active caspase-3 protein expression was increased 8.4-fold compared to the active caspase-3 protein expression in the controls. Furthermore, 4-phenylbutyric acid, an inhibitor of UPR, partly reduced cell apoptosis and activation of caspase-3. This study suggests that cholesterol overloading in hepatic L02 cells induces ERS and activates the UPR which, in part, leads to the apoptotic damage of cells.

  5. 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.

  6. Short communication: rising and lying behavior of heifers before and after alimentary oligofructose overload.

    PubMed

    Niss, D B; Herskin, M S; Danscher, A M; Thoefner, M B

    2009-02-01

    The aim of this experiment was to describe the rising and lying behavior of heifers in the first 5 d after alimentary oligofructose overload to 1) acquire information about consequences of this experimental disease model in terms of animal behavior; and 2) contribute to the evaluation of the influence of disease on cattle welfare. Eight tethered Holstein-Friesian heifers were used and their behavior was observed for 10.5 +/- 2.7 hours of light per day. Occurrence of rising and lying behavior and parts thereof were recorded. Clinical and physiological examinations were conducted throughout to confirm presence of ruminal acidosis and lameness. The duration of pre-lying intention movements were increased on d 3 after oligofructose overload compared with d -1 [28 (20 to 40) vs. 13 (10 to 16) s, respectively], and the duration of the total lying sequence was increased on d 1 and 3 compared with the control day [27 (22 to 33) and 36 (25 to 48) vs. 17 (13 to 21) s, respectively]. The frequency and duration of getting up did not differ between days. These results suggest that disease induced by oligofructose overload (i.e., ruminal acidosis and lameness) can affect lying behavior in heifers as shown by increased duration of lying intentions and difficulty in lying down, which may indicate that lying motivation was thwarted, possibly by pain or discomfort.

  7. Modeling of information diffusion in Twitter-like social networks under information overload.

    PubMed

    Li, Pei; Li, Wei; Wang, Hui; Zhang, Xin

    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.

  8. Information overload or search-amplified risk? Set size and order effects on decisions from experience.

    PubMed

    Hills, Thomas T; Noguchi, Takao; Gibbert, Michael

    2013-10-01

    How do changes in choice-set size influence information search and subsequent decisions? Moreover, does information overload influence information processing with larger choice sets? We investigated these questions by letting people freely explore sets of gambles before choosing one of them, with the choice sets either increasing or decreasing in number for each participant (from two to 32 gambles). Set size influenced information search, with participants taking more samples overall, but sampling a smaller proportion of gambles and taking fewer samples per gamble, when set sizes were larger. The order of choice sets also influenced search, with participants sampling from more gambles and taking more samples overall if they started with smaller as opposed to larger choice sets. Inconsistent with information overload, information processing appeared consistent across set sizes and choice order conditions, reliably favoring gambles with higher sample means. Despite the lack of evidence for information overload, changes in information search did lead to systematic changes in choice: People who started with smaller choice sets were more likely to choose gambles with the highest expected values, but only for small set sizes. For large set sizes, the increase in total samples increased the likelihood of encountering rare events at the same time that the reduction in samples per gamble amplified the effect of these rare events when they occurred-what we call search-amplified risk. This led to riskier choices for individuals whose choices most closely followed the sample mean.

  9. Magnetic Resonance Characterization of Hepatic Storage Iron in Transfusional Iron Overload

    PubMed Central

    Tang, Haiying; Jensen, Jens H.; Sammet, Christina L.; Sheth, Sujit; Swaminathan, Srirama V.; Hultman, Kristi; Kim, Daniel; Wu, Ed X.; Brown, Truman R.; Brittenham, Gary M.

    2013-01-01

    Purpose To quantify the two principal forms of hepatic storage iron, diffuse, soluble iron (primarily ferritin), and aggregated, insoluble iron (primarily hemosiderin) using a new MRI method in patients with transfusional iron overload. Materials and Methods Six healthy volunteers and twenty patients with transfusion-dependent thalassemia syndromes and iron overload were examined. Ferritin- and hemosiderin-like iron were determined based on the measurement of two distinct relaxation parameters: the “reduced” transverse relaxation rate, RR2 and the “aggregation index,” A, using three sets of Carr-Purcell-Meiboom-Gill (CPMG) datasets with different interecho spacings. Agarose phantoms, simulating the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron, were employed for validation. Results Both phantom and in vivo human data confirmed that transverse relaxation components associated with the dispersed and aggregated iron could be separated using the two-parameter (RR2, A) method. The MRI-determined total hepatic storage iron was highly correlated (r = 0.95) with measurements derived from biopsy or biosusceptometry. As total hepatic storage iron increased, the proportion stored as aggregated iron became greater. Conclusion This method provides a new means for non-invasive MRI determination of the partition of hepatic storage iron between ferritin and hemosiderin in iron overload disorders. PMID:23720394

  10. Stable overload conditions of high-temperature superconductors at alternating current injection

    NASA Astrophysics Data System (ADS)

    Romanovskii, V. R.

    2015-01-01

    The stability of alternating current injected into a high-temperature superconductor or into a current-carrying element on its basis is studied under weak cooling. The stability conditions of the current varying with time by a sinusoidal law are studied versus its frequency. It is shown that before unstable states set in, the peak values of the electric field intensity, current, and temperature in the superconductor are higher than the values determining a thermal electrodynamic stability boundary of the current permanently flowing through the superconductor—the so-called thermal quench current. It is found that ultimate stable alternating currents cause high stable thermal losses in superconductors; these losses being not considered in the modern theory of losses. Such stable conditions can be referred to as overload conditions. Analysis shows that there are characteristic times determining the time intervals within which alternating current is stable under overload conditions. Main thermoelectrodynamic mechanisms behind the existence of these intervals are formulated. They explain why the superconductor stable overheating and induced electric field reach high values before the injected alternating current becomes unstable. The existence of overload conditions considerably extends the application area of high-temperature superconductors.

  11. 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

  12. 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.

  13. Dietary phosphorus overload aggravates the phenotype of the dystrophin-deficient mdx mouse.

    PubMed

    Wada, Eiji; Yoshida, Mizuko; Kojima, Yoriko; Nonaka, Ikuya; Ohashi, Kazuya; Nagata, Yosuke; Shiozuka, Masataka; Date, Munehiro; Higashi, Tetsuo; Nishino, Ichizo; Matsuda, Ryoichi

    2014-11-01

    Duchenne muscular dystrophy is a lethal X-linked disease with no effective treatment. Progressive muscle degeneration, increased macrophage infiltration, and ectopic calcification are characteristic features of the mdx mouse, a murine model of Duchenne muscular dystrophy. Because dietary phosphorus/phosphate consumption is increasing and adverse effects of phosphate overloading have been reported in several disease conditions, we examined the effects of dietary phosphorus intake in mdx mice phenotypes. On weaning, control and mdx mice were fed diets containing 0.7, 1.0, or 2.0 g phosphorus per 100 g until they were 90 days old. Dystrophic phenotypes were evaluated in cryosections of quadriceps and tibialis anterior muscles, and maximal forces and voluntary activity were measured. Ectopic calcification was analyzed by electron microscopy to determine the cells initially responsible for calcium deposition in skeletal muscle. Dietary phosphorus overload dramatically exacerbated the dystrophic phenotypes of mdx mice by increasing inflammation associated with infiltration of M1 macrophages. In contrast, minimal muscle necrosis and inflammation were observed in exercised mdx mice fed a low-phosphorus diet, suggesting potential beneficial therapeutic effects of lowering dietary phosphorus intake on disease progression. To our knowledge, this is the first report showing that dietary phosphorus intake directly affects muscle pathological characteristics of mdx mice. Dietary phosphorus overloading promoted dystrophic disease progression in mdx mice, whereas restricting dietary phosphorus intake improved muscle pathological characteristics and function.

  14. 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

  15. 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.

  16. 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.

  17. Regulatory role of n-propanol in propylene glycol biomethanization under overload.

    PubMed

    Seok, Jonghyuk; Komisar, Simeon J

    2003-04-01

    This work examines the transient response of an anaerobic fluidized bed bioreactor to an overload of propylene glycol (PG), the primary component in aircraft de-icing waste. Under favorable operating conditions, PG was converted to n-propanol (n-PrOH) and propionate (HPr), and subsequently n-PrOH was completely converted into HPr. HPr was then fully degraded to methane and carbon dioxide via acetate. Under an overload condition, n-PrOH conversion to propionate was completely blocked but propionate degradation continued, contrary to free-energy computations in which n-PrOH should rapidly degrade and HPr should accumulate. When the imposed overload condition was relieved, the accumulated n-PrOH was rapidly converted into propionate. n-PrOH, then, could act as a temporal sink for reducing equivalents (XH(2)) and could regulate the overall PG methanazation process. n-PrOH should be monitored along with typical VFAs such as HPr to avoid sudden VFA accumulation and thus to optimize process performance for PG methanization.

  18. Predicting the Effects of Overloads on Sustained-Load Crack Growth in a High-Temperature Superalloy.

    DTIC Science & Technology

    1985-12-01

    test data *.... ’ .. generated on specimens of Inconel 718 at 650 C with periodic overloads of...generated test data (131 for Inconel 718 at 650 C, with an R ratio of 0.1 and frequency of 0.01 Hz. This frequency is approximately that of the single...retardation due to overloads. Predictions were compared with experimental test data generated on specimens of Inconel 718 at 650 C with

  19. Cytosolic H2O2 mediates hypertrophy, apoptosis, and decreased SERCA activity in mice with chronic hemodynamic overload

    PubMed Central

    Qin, Fuzhong; Siwik, Deborah A.; Pimentel, David R.; Morgan, Robert J.; Biolo, Andreia; Tu, Vivian H.; Kang, Y. James; Cohen, Richard A.

    2014-01-01

    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 Ca2+-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

  20. 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

  1. Separating plasticity-induced closure and residual stress contributions to fatigue crack retardation following an overload

    NASA Astrophysics Data System (ADS)

    Salvati, Enrico; Zhang, Hongjia; Fong, Kai Soon; Song, Xu; Korsunsky, Alexander M.

    2017-01-01

    The introduction of an overload or underload within a constant amplitude loading fatigue test leads to a retardation or acceleration of the Fatigue Crack Growth Rate (FCGR). The understanding of the causes of these effects is essential in the context of variable amplitude fatigue loading, since in principle any loading history can be represented as a sequence of overloads and underloads. In the case of overload, along with some other minor causes, the residual stress changes at the crack tip and crack closure behind the tip can be thought of as the main factors that affect the fatigue crack growth rate. Whilst this has been recognised and accepted for many decades, controversy persists regarding the relative significance and presence of these two effects, and consensus is yet to emerge. The effect of crack closure, when the baseline loading ratio is high enough, can be inhibited so that the main cause of retardation becomes doubtless the residual stress present ahead the crack tip. In the present paper we report our attempt to deconvolve the contributions of crack closure and residual stress on crack retardation following an overload. To accomplish this task we analyse the results of fatigue tests run at two baseline load ratios, namely R=0.1 and R=0.7. At the load ratio of R=0.7 the crack closure effect is not operative, as confirmed by Digital Image Correlation analysis of the crack flanks close to the tip, and post mortem fractographic analysis of crack surfaces. Therefore, for R=0.7 the compressive residual stress region created by the overload ahead of the crack tip is the sole mechanism causing crack retardation. Therefore, for R=0.7 the focus must be placed entirely on the strain field around the crack tip. To this end, line profiles along the crack bisector of elastic strain in the crack opening direction were collected at several stages of crack propagation past the overload using in situ Synchrotron X-ray Powder Diffraction (SXRPD) technique. By

  2. Effects of adding a weekly eccentric-overload training session on strength and athletic performance in team-handball players.

    PubMed

    Sabido, Rafael; HernáNdez-Davó, Jose Luis; Botella, Javier; Navarro, Angel; Tous-Fajardo, Julio

    2017-02-02

    To investigate the influence of adding a weekly eccentric-overload training (EOT) session in several athletic performance's tests, 18 team-handball players were assigned either to an EOT (n = 11) or a Control (n = 7) group. Both groups continued to perform the same habitual strength training, but the EOT group added one session/week during a 7-week training programme consisting of four sets of eight repetitions for the bilateral half-squat and unilateral lunge exercises. The test battery included handball throwing velocity, maximum dynamic strength (1RM), countermovement jump (CMJ), 20 m sprint, triple hop for distance, and eccentric/concentric power in both the half-squat and lunge exercises. Data were analysed using magnitude-based inferences. Both groups improved their 1RM in the half squat, 20 m sprint time, and CMJ performance to a similar extent, but the EOT group showed a beneficial effect for both right [(42/58/0), possibly positive] and left [(99/1/0), very likely positive] triple hop for distance performance. In addition, the EOT group showed greater power output improvements in both eccentric and concentric phases of the half-squat (difference in percent of change ranging from 6.5% to 22.0%) and lunge exercises (difference in per cent of change ranging from 13.1% to 24.9%). Nevertheless, no group showed changes in handball throwing velocity. Selected variables related to team-handball performance (i.e. functional jumping performance, power output) can be improved by adding a single EOT session per week, highlighting the usefulness of this low-volume/high-intensity training when aiming at optimizing dynamic athletic performance.

  3. 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;