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Sample records for subendocardial viability ratio

  1. [Hemodialysis improves the subendocardial viability ratio].

    Science.gov (United States)

    De Blasio, Antonella; Sirico, Maria; Di Micco, Lucia; Di Iorio, Biagio

    2013-01-01

    The subendocardial viability ratio (SEVR), a parameter introduced by Buckberg, represents a non-invasive measure of myocardial perfusion related to left ventricular work. AIM. The aim of this study was to verify if dialysis may determine modifications of SEVR and how these modifications are modulated in the 2-day interdialytic period. METHODS.We studied 54 subjects of mean age 6314 years and receiving dialysis for 3215 months. Exclusion criteria were diabetes, resistant hypertension and peripheral vascular diseases and intradialytic hypotension evidenced during the study dialysis session. Pulse wave velocity and SEVR assessments were performed during the third dialysis session of the week, before (pre-HD) and after (post-HD) dialysis, in 2-day interdialytic period after and at the beginning of the following dialysis session. RESULTS.Dialysis reduces PWV, in particular the tertile with the lowest PWV presents the highest percentage reduction (-26%) compared with the second and the third tertiles. In the same way, dialysis leads to an increase of SEVR and patients in the tertile with the highest SEVR values maintain high SEVR values during dialysis and in the interdialytic period. Patients with severe vascular calcifications present higher PWV value and lower SEVR value. CONCLUSIONS.The results of present study demonstrate that ultrafiltration improves PWV (with a mean reduction of 16%) and SEVR (increase of 13%) and that the severity of vascular calcifications influences the effect of ultrafiltration on these two parameters. More studies are certainly necessary to verify our findings. Considered the higher mortality of patients with higher SEVR, it would be important to understand if new dialytic strategies are needed in patients with higher PVW and lower SEVR values.

  2. Baseline subendocardial viability ratio influences left ventricular systolic improvement with cardiac rehabilitation

    National Research Council Canada - National Science Library

    Emre Aslanger; Benjamin Assous; Nicolas Bihry; Florence Beauvais; Damien Logeart; Alain Cohen Solal

    2017-01-01

      Objective: Subendocardial viability ratio (SEVR), defined as diastolic to systolic pressure-time integral ratio, is a useful tool reflecting the balance between coronary perfusion and arterial load...

  3. Altered arterial stiffness and subendocardial viability ratio in young healthy light smokers after acute exercise.

    Directory of Open Access Journals (Sweden)

    Robert J Doonan

    Full Text Available Studies showed that long-standing smokers have stiffer arteries at rest. However, the effect of smoking on the ability of the vascular system to respond to increased demands (physical stress has not been studied. The purpose of this study was to estimate the effect of smoking on arterial stiffness and subendocardial viability ratio, at rest and after acute exercise in young healthy individuals.Healthy light smokers (n = 24, pack-years = 2.9 and non-smokers (n = 53 underwent pulse wave analysis and carotid-femoral pulse wave velocity measurements at rest, and 2, 5, 10, and 15 minutes following an exercise test to exhaustion. Smokers were tested, 1 after 12h abstinence from smoking (chronic condition and 2 immediately after smoking one cigarette (acute condition. At rest, chronic smokers had higher augmentation index and lower aortic pulse pressure than non-smokers, while subendocardial viability ratio was not significantly different. Acute smoking increased resting augmentation index and decreased subendocardial viability ratio compared with non-smokers, and decreased subendocardial viability ratio compared with the chronic condition. After exercise, subendocardial viability ratio was lower, and augmentation index and aortic pulse pressure were higher in non-smokers than smokers in the chronic and acute conditions. cfPWV rate of recovery of was greater in non-smokers than chronic smokers after exercise. Non-smokers were also able to achieve higher workloads than smokers in both conditions.Chronic and acute smoking appears to diminish the vascular response to physical stress. This can be seen as an impaired 'vascular reserve' or a blunted ability of the blood vessels to accommodate the changes required to achieve higher workloads. These changes were noted before changes in arterial stiffness or subendocardial viability ratio occurred at rest. Even light smoking in young healthy individuals appears to have harmful effects on vascular

  4. Altered arterial stiffness and subendocardial viability ratio in young healthy light smokers after acute exercise.

    Science.gov (United States)

    Doonan, Robert J; Scheffler, Patrick; Yu, Alice; Egiziano, Giordano; Mutter, Andrew; Bacon, Simon; Carli, Franco; Daskalopoulos, Marios E; Daskalopoulou, Stella S

    2011-01-01

    Studies showed that long-standing smokers have stiffer arteries at rest. However, the effect of smoking on the ability of the vascular system to respond to increased demands (physical stress) has not been studied. The purpose of this study was to estimate the effect of smoking on arterial stiffness and subendocardial viability ratio, at rest and after acute exercise in young healthy individuals. Healthy light smokers (n = 24, pack-years = 2.9) and non-smokers (n = 53) underwent pulse wave analysis and carotid-femoral pulse wave velocity measurements at rest, and 2, 5, 10, and 15 minutes following an exercise test to exhaustion. Smokers were tested, 1) after 12h abstinence from smoking (chronic condition) and 2) immediately after smoking one cigarette (acute condition). At rest, chronic smokers had higher augmentation index and lower aortic pulse pressure than non-smokers, while subendocardial viability ratio was not significantly different. Acute smoking increased resting augmentation index and decreased subendocardial viability ratio compared with non-smokers, and decreased subendocardial viability ratio compared with the chronic condition. After exercise, subendocardial viability ratio was lower, and augmentation index and aortic pulse pressure were higher in non-smokers than smokers in the chronic and acute conditions. cfPWV rate of recovery of was greater in non-smokers than chronic smokers after exercise. Non-smokers were also able to achieve higher workloads than smokers in both conditions. Chronic and acute smoking appears to diminish the vascular response to physical stress. This can be seen as an impaired 'vascular reserve' or a blunted ability of the blood vessels to accommodate the changes required to achieve higher workloads. These changes were noted before changes in arterial stiffness or subendocardial viability ratio occurred at rest. Even light smoking in young healthy individuals appears to have harmful effects on vascular function

  5. Changes in subendocardial viability ratio with acute high-altitude exposure and protective role of acetazolamide.

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    Salvi, Paolo; Revera, Miriam; Faini, Andrea; Giuliano, Andrea; Gregorini, Francesca; Agostoni, Piergiuseppe; Becerra, Carlos G Ramos; Bilo, Grzegorz; Lombardi, Carolina; O'Rourke, Michael F; Mancia, Giuseppe; Parati, Gianfranco

    2013-04-01

    High-altitude tourism is increasingly frequent, involving also subjects with manifest or subclinical coronary artery disease. Little is known, however, on the effects of altitude exposure on factors affecting coronary perfusion. The aim of our study was to assess myocardial oxygen supply/demand ratio in healthy subjects during acute exposure at high altitude and to evaluate the effect of acetazolamide on this parameter. Forty-four subjects (21 men, age range: 24-59 years) were randomized to double-blind acetazolamide 250 mg bid or placebo. Subendocardial viability ratio and oxygen supply/demand ratio were estimated on carotid artery by means of a validated PulsePen tonometer, at sea level, before and after treatment, and after acute and more prolonged exposure to high altitude (4559 m). On arrival at high altitude, subendocardial viability ratio was reduced in both placebo (from 1.63±0.15 to 1.18±0.17; PSubendocardial viability ratio returned to sea level values (1.65±0.24) after 3 days at high altitude under acetazolamide but remained lower than at sea level under placebo (1.42±0.22; Psubendocardial oxygen supply triggered by exposure to hypobaric hypoxia. Further studies involving also subjects with known or subclinical coronary artery disease are needed to confirm a protective action of acetazolamide on myocardial viability under high-altitude exposure.

  6. Severity of peripheral arterial disease is associated with aortic pressure augmentation and subendocardial viability ratio.

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    Mosimann, Kathrin; Jacomella, Vincenzo; Thalhammer, Christoph; Meier, Thomas O; Kohler, Malcolm; Amann-Vesti, Beatrice; Husmann, Marc

    2012-12-01

    Peripheral arterial disease (PAD) is associated with increased cardiovascular mortality that correlates with peripheral perfusion impairment as assessed by the ankle-brachial arterial pressure index (ABI). Furthermore, PAD is associated with arterial stiffness and elevated aortic augmentation index (AIx). The purpose of this study was to investigate whether ABI impairment correlates with AIx and subendocardial viability ratio (SEVR), a measure of cardiac perfusion during diastole. AIx and SEVR were assessed by radial applanation tonometry in 65 patients with stable PAD (Rutherford stage I-III) at a tertiary referral center. AIx corrected for heart rate and SEVR were tested in a multivariate linear and logistic regression model to determine the association with ABI. Mean ABI was 0.8±0.2, AIx 31%±7%, and SEVR 141%±26%. Multiple linear regression with AIx as a dependent variable revealed that AIx was significantly negatively associated with ABI (β=-11.5; 95% confidence interval [CI], -18.6 to -4.5; P=.002). Other variables that were associated with AIx were diastolic blood pressure (β=0.2; 95% CI, 0.1-0.4; Psubendocardial viability ratio. This may be a potential pathophysiologic link that impacts cardiac prognosis in patients with PAD. © 2012 Wiley Periodicals, Inc.

  7. Subendocardial viability ratio predicts cardiovascular mortality in chronic kidney disease patients.

    Science.gov (United States)

    Di Micco, L; Salvi, P; Bellasi, A; Sirico, M L; Di Iorio, B

    2013-01-01

    The subendocardial viability ratio (SEVR), calculated by pulse wave analysis, is an index of myocardial oxygen supply and demand. Here we analyze the relation between SEVR and cardiovascular mortality in the chronic kidney disease (CKD) population of a post hoc analysis of a multicenter, prospective, randomized, nonblinded study. We studied 212 consecutive asymptomatic outpatients receiving care at 12 nephrology clinics in south Italy. Inclusion criteria were age >18 years, 6 months of follow-up before the enrollment and stage 3-4 CKD. During follow-up, 34 subjects died, 29 of them for cardiovascular causes. SEVR correlated inversely with vascular calcifications (r = -0.37) and myocardial mass (r = -0.45); SEVR changed from 1.33 ± 0.24 to 1.36 ± 0.16 (p = NS; baseline and final values, respectively) in living patients, and from 1.16 ± 0.31 to 0.68 ± 0.26 in deceased patients (p < 0.001). Kaplan-Meier curves show that that a greater reduction of SEVR values during the study (third tertile) significantly predicts cardiovascular mortality (p < 0.0001). This post hoc analysis shows that a reduction of SEVR values impacts cardiovascular mortality in CKD patients. Copyright © 2013 S. Karger AG, Basel.

  8. Subendocardial viability ratio and ejection duration as parameters of early cardiovascular risk in children.

    Science.gov (United States)

    Marčun-Varda, Nataša; Nikolic, Sara; Močnik, Mirjam

    The purpose of this study was to investigate subendocardial viability ratio (SEVR) and ejection duration (ED) in children and adolescents with common cardiovascular risk factors such as arterial hypertension, obesity, and hypercholesterolemia. Four groups of pediatric patients were analyzed: 31 children and adolescents had hypertension, 36 were overweight, 49 were overweight and had hypertension, and 70 had hypercholesterolemia. The patients were compared to a control group of 50 healthy individuals. Subjects were sampled by opportunity sampling at the Department of Pediatrics Maribor, Slovenia. In each patient, blood pressure, anthropometrical parameters, and pulse wave analysis (PWA) measurements using applanation tonometry technique were performed and calculated. The results show a statistically-significant difference in ED (p = 0.013) but not in SEVR (p = 0.074) in the hypercholesterolemia group in comparison to the control group. In other research groups, no statistically-significant differences were found. In all study groups, SEVR correlated significantly with age (positive, moderate) and heart rate (negative, strong) as well as with central mean pressure (CMP). Our study does not show a significant role of SEVR and ED in early cardiovascular risk determination in children. However, some results do indicate a potential role of both, at least in hypercholesterolemia, and should be further investigated.
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  9. Baseline subendocardial viability ratio influences left ventricular systolic improvement with cardiac rehabilitation.

    Science.gov (United States)

    Aslanger, Emre; Assous, Benjamin; Bihry, Nicolas; Beauvais, Florence; Logeart, Damien; Cohen-Solal, Alain

    2017-01-01

    Subendocardial viability ratio (SEVR), defined as diastolic to systolic pressure-time integral ratio, is a useful tool reflecting the balance between coronary perfusion and arterial load. Suboptimal SEVR creating a supply-demand imbalance may limit favorable cardiac response to cardiac rehabilitation (CR). To explore this hypothesis, we designed a study to analyze the relationship between baseline SEVR and response to CR in patients with coronary artery disease (CAD). In this prospectively study, after baseline arterial tonometry, echocardiography, and cardiopulmonary exercise tests (CPETs), patients undergone 20 sessions of CR. Post-CR echocardiographic and CPET measurements were obtained for comparison. Final study population was comprised of fifty subjects. Study population was divided into two subgroups by median SEVR value (1.45, interquartile range 0.38). Although both groups showed significant improvements in peak VO2, significant improvements in oxygen pulse (πO2) (from 16.1±3.4 to 19.1±4.8 mL O2.kg-1.beat-1; p<0.001) and stroke volume index (from 31±5 to 35±6 mL; p=0.008) were observed in only the patients in the above-median subgroup. The change in πO2 was also significantly higher in the above-median SEVR subgroup (2.9±3.3 vs. 0.5±2.4; p=0.007). Our study shows that baseline supply-demand imbalance may limit systolic improvement response to CR in patients with CAD.

  10. Effect of the arteriovenous access for hemodialysis on subendocardial viability ratio, pulse pressure and hospitalizations.

    Science.gov (United States)

    Vizinho, Ricardo Senos; Santos, Catarina; Lucas, Carlos; Adragão, Teresa; Barata, José Diogo

    2014-10-01

    In some patients the potential benefits of the arteriovenous (AV) access over catheter for hemodialysis seem to be outweighed by global cardiovascular status deterioration. We prospectively evaluated 44 pre-dialysis chronic kidney disease patients submitted to vascular access creation during a follow-up of 25 ± 9 months. We performed pulse wave analysis and biochemical assessment before and 2 months after AV access construction, and we registered premature vascular access thrombosis, and all-cause and cardiovascular hospitalizations throughout follow-up. We found a statistically significant decrease in the subendocardial viability ratio (SEVR) and pulse pressure (PP) parameters after AV access creation while brain natriuretic peptide significantly increased. Receiver operating characteristic curve analysis identified SEVR ≤113 % evaluated 2 months after vascular access construction as the best cutoff value for predicting all-cause and cardiovascular hospitalizations. Kaplan-Meier analysis showed that a SEVR ≤113 % was associated with all-cause (p = 0.010) and cardiovascular (p = 0.029) hospitalizations; Cox regression analysis verified a 4.9-fold higher risk of all-cause hospitalization in patients with SEVR ≤113 % (p = 0.005). To our best knowledge, this report indicates, for the first time, that despite the decrease in PP parameters, the creation of a vascular access for hemodialysis was also associated with a reduction of SEVR which predicted a worse clinical outcome. We argue that the decrease of pulse pressure after arteriovenous construction may reflect a new hemodynamic set-point after vascular access creation and may not indicate a protective cardiovascular effect.

  11. Relationship between subendocardial viability ratio and hemoglobin in patients with chronic kidney disease.

    Science.gov (United States)

    Ekart, Robert; Bevc, Sebastjan; Hojs, Nina; Stropnik Galuf, Tina; Hren, Martin; Dvoršak, Benjamin; Knehtl, Maša; Jakopin, Eva; Krajnc, Igor; Hojs, Radovan

    Pulse wave analysis (PWA) uses the technique of applanation tonometry to obtain a peripheral pulse pressure waveform from which central hemodynamic information is derived. Using PWA, subendocardial viability ratio (SEVR) can be measured. SEVR represents a noninvasive measure of myocardial perfusion. It is related to the work of the heart, the oxygen consumption, and the energy supply of the heart. Anemia is a common complication of chronic kidney disease (CKD). A complex relationship exists between CKD, cardiovascular disease (CVD), and anemia. The aim of our study was to assess the relationship between SEVR and hemoglobin in non-dialysis CKD patients. We examined the associations between PWA hemodynamic parameters, 24-hour ambulatory blood pressure (BP) measurements, and laboratory variables including hemoglobin, cardiac biomarkers troponin I, NT-proBNP, and hs-CRP in a cohort of 91 nondialysis CKD patients. PWA was assessed by radial applanation tonometry (SphygmoCor, Atcor, Sydney, Australia). The patients were divided into two groups according to the median value of hemoglobin. Mean age of included patients was 60.2 years, 67% were men, 44% were smokers, 25.3% had diabetes. A significant correlation between hemoglobin and SEVR was found (r = 0.26; p = 0.012). With multivariate regression analysis, SEVR as dependent variable turned out to be statistically significantly associated with hemoglobin (β = 0.344, p = 0.013) and with troponin I (β = -0.217, p = 0.037). Patients in the group with lower hemoglobin had statistically-significantly higher serum creatinine, cystatin C, NT-proBNP, and 24-hour ambulatory systolic BP and lower e-GFR, SEVR, and office diastolic BP. Results of our study show that SEVR is independently associated with hemoglobin in nondialysis CKD patients. CKD patients with lower hemoglobin have lower SEVR.
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  12. Albuminuria is Associated With Subendocardial Viability Ratio in Chronic Kidney Disease Patients

    Directory of Open Access Journals (Sweden)

    Robert Ekart

    2015-10-01

    Full Text Available Background/Aims: Albuminuria is a well-established marker of subclinical organ damage. Pulse-wave analysis (PWA employs the technique of applanation tonometry to obtain a peripheral pulse pressure waveform, from which central hemodynamic data are derived by application of the transfer function. Using PWA we can measure the subendocardial viability ratio (SEVR and ejection duration (ED. SEVR or the Buckberg index is a non-invasive estimate of myocardial workload, oxygen supply and perfusion and a measure of the ability of the arterial system to meet the heart`s energy requirements. ED is the duration of ventricular ejection. The objective of this study was to evaluate the relationship between albuminuria and PWA parameters in chronic kidney disease (CKD patients. Methods: We studied 86 CKD patients aged 59.8±13.5 years, 56 (65.1% were male. PWA analysis and 24-hour ambulatory blood pressure (24hABP monitoring were performed. The following parameters were calculated: (1 aortic augmentation index with and without correction for a heart rate of 75 (Aix and AIx@ HR75, (2 SEVR, calculated as the ratio of the diastolic pressure time index and the systolic pressure time index, (3 ED, (4 estimated central aortic systolic and diastolic pressure and (5 central aortic pulse pressure calculated as the difference between estimated aortic systolic and diastolic BP. Blood samples and urine albumin-to-creatinine ratio (UACR were analyzed; UACR values were natural log transformed (lnUACR. Results: Using CKD-EPI creatinine-cystatin C formula the eGFR in patients was 7-130 ml/min/1.73m2 (mean 32.6; SD±24.6. We found statistically significant correlation between lnUACR and cystatin C (r=0.308; P=0.004, eGFR (r=-0.219; P=0.04, hemoglobin (r=-0.255; P=0.02, phosphorus (r=0.222; P=0.04, iPTH (r=0.268; P=0.01, SEVR (r=-0.254; P=0.02 and ED (r=0.315; P=0.003. No statistically significant correlations between lnUACR and cardiac biomarkers TnI, NT-proBNP, central aortic

  13. Albuminuria is Associated With Subendocardial Viability Ratio in Chronic Kidney Disease Patients.

    Science.gov (United States)

    Ekart, Robert; Bevc, Sebastjan; Hojs, Nina; Knehtl, Maša; Dvoršak, Benjamin; Hojs, Radovan

    2015-01-01

    Albuminuria is a well-established marker of subclinical organ damage. Pulse-wave analysis (PWA) employs the technique of applanation tonometry to obtain a peripheral pulse pressure waveform, from which central hemodynamic data are derived by application of the transfer function. Using PWA we can measure the subendocardial viability ratio (SEVR) and ejection duration (ED). SEVR or the Buckberg index is a non-invasive estimate of myocardial workload, oxygen supply and perfusion and a measure of the ability of the arterial system to meet the heart`s energy requirements. ED is the duration of ventricular ejection. The objective of this study was to evaluate the relationship between albuminuria and PWA parameters in chronic kidney disease (CKD) patients. We studied 86 CKD patients aged 59.8±13.5 years, 56 (65.1%) were male. PWA analysis and 24-hour ambulatory blood pressure (24hABP) monitoring were performed. The following parameters were calculated: (1) aortic augmentation index with and without correction for a heart rate of 75 (Aix and AIx@ HR75), (2) SEVR, calculated as the ratio of the diastolic pressure time index and the systolic pressure time index, (3) ED, (4) estimated central aortic systolic and diastolic pressure and (5) central aortic pulse pressure calculated as the difference between estimated aortic systolic and diastolic BP. Blood samples and urine albumin-to-creatinine ratio (UACR) were analyzed; UACR values were natural log transformed (lnUACR). Using CKD-EPI creatinine-cystatin C formula the eGFR in patients was 7-130 ml/min/1.73 m² (mean 32.6; SD±24.6). We found statistically significant correlation between lnUACR and cystatin C (r=0.308; P=0.004), eGFR (r=-0.219; P=0.04), hemoglobin (r=-0.255; P=0.02), phosphorus (r=0.222; P=0.04), iPTH (r=0.268; P=0.01), SEVR (r=-0.254; P=0.02) and ED (r=0.315; P=0.003). No statistically significant correlations between lnUACR and cardiac biomarkers TnI, NT-proBNP, central aortic BP and 24h ABP values were

  14. Subendocardial viability ratio as an index of impaired coronary flow reserve in hypertensives without significant coronary artery stenoses.

    Science.gov (United States)

    Tsiachris, D; Tsioufis, C; Syrseloudis, D; Roussos, D; Tatsis, I; Dimitriadis, K; Toutouzas, K; Tsiamis, E; Stefanadis, C

    2012-01-01

    Subendocardial viability ratio (SEVR), calculated through pulse wave analysis, is an index of myocardial oxygen supply and demand. Our aim was to evaluate the relationship between coronary flow reserve (CFR) and SEVR in 36 consecutive untreated hypertensives (aged 57.9 years, 12 males, all Caucasian) with indications of myocardial ischaemia and normal coronary arteries in coronary angiography. CFR was calculated by a 0.014-inch Doppler guidewire (Flowire, Volcano, San Diego, CA, USA) in response to bolus intracoronary administration of adenosine (30-60 μg). SEVR was calculated by radial applanation tonometry, while diastolic function was evaluated by means of transmitral flow and tissue Doppler imaging. Hypertensive patients with low CFR (n=24) compared with those with normal CFR (n=12) exhibited significantly decreased SEVR by 24.5% (P=0.002). In hypertensives with low CFR, CFR was correlated with SEVR (r=0.651, P=0.001). After applying multivariate linear regression analysis, age, left ventricular mass index, Em/Am, 24-h diastolic blood pressure (BP) and SEVR turned out to be the only independent predictors of CFR (adjusted R(2)=0.718). Estimation of SEVR by using applanation tonometry may provide a reliable tool for the assessment of coronary microcirculation in essential hypertensives with indications of myocardial ischaemia and normal coronary arteries.

  15. Augmentation Pressure and Subendocardial Viability Ratio are associated with microalbuminuria and with poor renal function in type 1 diabetes

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    Prince, Catherine T.; Secrest, Aaron M.; Mackey, Rachel H.; Arena, Vincent C.; Kingsley, Lawrence A.; Orchard, Trevor J.

    2011-01-01

    This report explores the hypothesis that arterial stiffness indices, which predict cardiovascular disease, might also correlate with microalbuminuria (MA) in type 1 diabetes (T1D), and thus have potential for risk assessment. Three pulse wave analysis indices, measured using the SphygmoCor device, were evaluated on 144 participants with childhood-onset T1D. These variables, augmentation index (AIx) and augmentation pressure (AP), and subendocardial viability ratio (SEVR, an estimate of myocardial perfusion) were each analyzed cross-sectionally in relation to both prevalent MA (defined as albumin excretion rate (AER)=20–199 μg/min) and renal function (assessed by both estimated glomerular filtration rate (eGFR) and serum cystatin C). AP and SEVR were each univariately associated with AER, eGFR and cystatin C. Lower SEVR was also independently related to the presence of microalbuminuria and degree of albuminuria within normo- and microalbuminuric participants. SEVR, not AP, was independently and negatively associated with both measures of renal function. SEVR is a better predictor of AER than brachial blood pressure measures in those without clinical proteinuria, indicating a potential use for pulse wave analysis in the early detection of individuals at risk for cardiovascular and renal complication of T1D. PMID:20605853

  16. Role of heart rate in the relation between regional body fat and subendocardial viability ratio in women.

    Science.gov (United States)

    Gonzales, Joaquin U; Hadri, Omar

    2016-09-01

    Subendocardial viability ratio (SEVR) is a measure of left ventricular function, specifically; it is an index of myocardial perfusion relative to left ventricular workload. Women have lower SEVR than men, partly due to a faster resting heart rate that reduces diastolic time (i.e., time for myocardial perfusion). It is unclear if body fat relates to SEVR, thus the purpose of this study was to examine the relation between body fat and SEVR in women. Twenty-eight middle-aged (31-45 years) and 31 older (60-80 years) women were examined. Radial artery applanation tonometry was used to calculate SEVR from a synthesized central aortic pressure wave. Dual-energy X-ray absorptiometry was used to assess body composition including fat in the trunk, legs, android and gynoid regions. Body fat was not related (P>.05) with SEVR in older women. In middle-aged women, all measures of regional fat were correlated with heart rate (range, r=.49-.59, P≤.01) and SEVR (range, r=.43-.53, P≤.01). Android-to-gynoid ratio was identified as the strongest predictor (r(2) =-.26, P<.01) of SEVR among measures of regional fat. Middle-aged women with lower android-to-gynoid fat ratio had higher SEVR (1.96±0.33 vs 1.66±0.20, P=.009) than women with higher fat ratio, even after adjusting for age, height, daily physical activity, and aortic mean pressure (P=.02). Adjusting for heart rate or diastolic time abolished the difference in SEVR between groups (1.80±0.09 vs 1.82±0.09, P=.56). These results suggest that middle-aged women with a greater distribution of fat in the abdomen have poorer left ventricular function that is dependent on the negative influence of heart rate on diastolic time. © 2016 John Wiley & Sons Australia, Ltd.

  17. Subendocardial Viability Ratio Is Impaired in Highly Proteinuric Chronic Kidney Disease Patients With Low Estimated Glomerular Filtration Rate.

    Science.gov (United States)

    Ekart, Robert; Šegula, Anja; Hartman, Tanja; Hojs, Nina; Hojs, Radovan

    2016-06-01

    Proteinuria and estimated glomerular filtration rate (eGFR) are markers of chronic kidney disease (CKD) and cardiovascular disease. With applanation tonometry, pulse wave analysis and many hemodynamic data are available. One of them is the subendocardial viability ratio (SEVR) which represents a non-invasive measure of myocardial perfusion related to the work of the heart. The aim of our study was to investigate the importance of SEVR in proteinuric CKD patients and healthy subjects. We performed a cross-sectional study in a cohort of 90 non-dialysis CKD patients and 39 healthy controls. SEVR was assessed by radial applanation tonometry (SphygmoCor, Atcor, Australia). Blood samples and urine albumin-to-creatinine ratio (UACR) were analyzed. CKD patients were divided in four groups according to the UACR and eGFR: CKD group 1: UACR > 1000 mg/g and eGFR  1000 mg/g and eGFR >30 mL/min; CKD group 3: UACR 30 mL/min. Using one-way ANOVA, we found a statistically significant difference in SEVR only between CKD group 1 and all other CKD groups and healthy control group (P < 0.022). Results of our study show that only CKD patients with UACR more than 1000 mg/g and eGFR below 30 mL/min have significantly lower SEVR. © 2016 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

  18. Reduced Subendocardial Viability Ratio Is Associated With Unfavorable Cardiovascular Risk Profile in Women With Short Duration of Type 2 Diabetes.

    Science.gov (United States)

    Laugesen, Esben; Høyem, Pernille; Fleischer, Jesper; Kumarathas, Indumathi; Knudsen, Søren T; Hansen, Klavs W; Christiansen, Jens Sandahl; Hansen, Troels K; Poulsen, Per L

    2016-10-01

    The pathophysiological perturbations underlying the unfavorable cardiovascular prognosis in women with type 2 diabetes (T2DM) remain elusive. Low subendocardial viability ratio (SEVR), an index of myocardial oxygen supply and demand, has been associated with intermediate cardiovascular risk markers and cardiovascular mortality in various populations. However, whether SEVR is associated with sex and cardiovascular risk markers in patients with T2DM remains to be clarified. We examined 86 T2DM patients (mean age 59±10 years, 47% women, median diabetes duration 1.9 (range 0.2-5.0) years) and 86 sex- and age-matched control subjects in a cross-sectional study. SEVR was noninvasively assessed by tonometry and markers of cardiovascular risk by carotid-femoral pulse wave velocity (PWV), homeostasis model assessment of insulin resistance (HOMA2-IR), C-reactive protein, urinary albumin/creatinine ratio, and heart rate variability. Women with diabetes had significantly lower SEVR compared to both men with diabetes (161% ± 26% vs. 178% ± 32%, P < 0.01), women without diabetes (185% ± 24%, P < 0.001), and men without diabetes (188% ± 28%, P < 0.001). The differences remained significant after adjustment for age, systolic blood pressure, heart rate, diabetes, and smoking. SEVR was associated with PWV, HOMA2-IR, C-reactive protein, and reduced heart rate variability in patients and control subjects, but the associations became nonsignificant after adjustment for heart rate. SEVR is reduced in women with short duration of T2DM and associated with cardiovascular risk markers. The latter association seems to be at least partly mediated via heart rate. We hypothesize that reduced SEVR may contribute to the unfavorable cardiovascular prognosis in women with diabetes. © American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Subendocardial viability ratio estimated by arterial tonometry: a critical evaluation in elderly hypertensive patients with increased aortic stiffness.

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    Chemla, Denis; Nitenberg, Alain; Teboul, Jean-Louis; Richard, Christian; Monnet, Xavier; le Clesiau, Hervé; Valensi, Paul; Brahimi, Mabrouk

    2008-08-01

    1. Increased aortic stiffness predisposes to myocardial ischaemia by increasing the systolic tension-time index and by decreasing aortic pressure throughout diastole. The tonometric subendocardial viability ratio (SEVR) is a non-invasive estimate of myocardial perfusion relative to cardiac workload. The hypothesis that SEVR is impaired in elderly hypertensives with high aortic pulse pressure (PP) was tested in the present study. 2. The SEVR was calculated by radial applanation tonometry in 203 subjects. In addition, diastolic time (DT), systolic time (ST) and mean diastolic and systolic aortic pressures (Pd and Ps, respectively) were calculated. First, 60 subjects matched for age and gender were analysed (20 controls, 20 hypertensives with pulse pressure (PP) 60 mmHg; mean (+/-SD) age 64 +/- 9 years; 24 women, 36 men). The remaining 143 subjects, aged 53 +/- 10 years, were analysed subsequently. 3. The SEVR was similar in the three elderly groups (1.39 +/- 0.34, 1.39 +/- 0.28 and 1.35 +/- 0.25, in controls and hypertensive patients with PP 60 mmHg, respectively). The SEVR was positively related to DT/ST (r(2) = 0.89) and to DT (r(2) = 0.73) and was negatively related to heart rate (r(2) = 0.56; P 60 mmHg than in hypertensives with normal PP. The positive linear relationship between SEVR and DT/ST was confirmed in the remaining 143 subjects (r(2) = 0.90), with no influence of aortic pressure. 4. The tonometric SEVR was not impaired in elderly hypertensive patients with increased aortic stiffness. In resting elderly and middle-aged individuals, the tonometric SEVR was mainly related to DT/ST ratio, not to aortic pressure.

  20. Subendocardial viability ratio in patients with rheumatoid arthritis: comparison with healthy controls and identification of prognostic factors.

    Science.gov (United States)

    Anyfanti, Panagiota; Triantafyllou, Areti; Gkaliagkousi, Eugenia; Triantafyllou, Georgios; Koletsos, Nikolaos; Chatzimichailidou, Sophia; Panagopoulos, Panagiotis; Botis, Ioannis; Aslanidis, Spyros; Douma, Stella

    2017-06-01

    Cardiac involvement is common in rheumatoid arthritis. Subendocardial viability ratio (SEVR) is a non-invasive measure of microvascular coronary perfusion, yet it remains unclear whether it is affected in rheumatoid arthritis patients. We additionally sought predictors of SEVR in rheumatoid arthritis among a wide range of disease-related parameters, cardiac and hemodynamic factors, and markers of atherosclerosis, arteriosclerosis, and endothelial dysfunction. SEVR was estimated in rheumatoid arthritis patients and healthy controls by applanation tonometry, which was also used to evaluate arterial stiffness (pulse wave velocity and augmentation index). In the rheumatoid arthritis group, carotid intima-media thickness (cIMT) was additionally estimated by ultrasound, cardiac and hemodynamic parameters by impedance cardiography, and endothelial dysfunction by measurement of asymmetric dimethylarginine (ADMA). In a total of 122 participants, SEVR was lower among 91 patients with rheumatoid arthritis compared to 31 controls (141.4 ± 21.9 vs 153.1 ± 18.7%, p = 0.009) and remained so among 29 rheumatoid arthritis patients without hypertension, diabetes, or cardiovascular diseases, compared to the control group (139.7 ± 21.7 vs 153.1 ± 18.7%, p = 0.013). SEVR did not significantly correlate with arterial stiffness, cIMT, ADMA, or disease-related parameters. Multivariate analysis revealed gender (p = 0.007), blood pressure (p = 0.028), heart rate (p = 0.025), cholesterol levels (p = 0.008), cardiac index (p rheumatoid arthritis. Patients with rheumatoid arthritis exhibit lower values of SEVR compared to healthy individuals. Cardiac and hemodynamic parameters, rather than functional indices of endothelial and macrovascular dysfunction, may be useful as predictors of myocardial perfusion in rheumatoid arthritis.

  1. A new tonometric device for radial augmentation index and subendocardial viability ratio: potential use in health screening.

    Science.gov (United States)

    Wang, Jing-Zhi; Zhang, Yong-Liang; Hu, Fu-Song; He, Zi-Jun; Yang, Xian-Jun; Ma, Zu-Chang; Sun, Yi-Ning

    2014-10-01

    Augmentation index (AIx) and subendocardial viability ratio (SEVR) are widely accepted indices of wave reflection and myocardial oxygen demand relative to supply. This study aimed to validate a new tonometric device (IIM-2010A) for obtaining AIx and SEVR from radial artery. A total of 68 outpatients (32 men and 36 women) aged 20 to 76 years (44.7±16.6 years) recruited from a health screening center participated in the study. AIx was obtained from radial pressure using the HEM-9000AI and IIM-2010A devices, while SEVR was measured from carotid pressure with the tonometric method and from radial pressure by the IIM-2010A device. In a subgroup of 24 patients, the measurements of AIx and SEVR were repeated after an interval of 10 minutes. The correlation of radial AIx between the IIM-2010A and HEM-9000AI devices was highly significant (r=0.956, P<.01). Radial SEVR determined from IIM-2010A was also highly related to carotid SEVR (r=0.864, P<.01), although the value was about 13.1% lower. There was no statistically significant difference between the repeated measurements of both indices. The lower coefficient of variation (2.9% vs 4.3% for AIx, 3.3% vs 4.1% for SEVR) and higher intraclass correlation coefficient (0.96 vs 0.91 for AIx, 0.93 vs 0.86 for SEVR) of IIM-2010A confirmed better short-term reproducibility, compared with the HEM-9000AI device and carotid tonometry. The new tonometric device IIM-2010A is effective and reproducible in calculating radial AIx and SEVR and has potential use in health screening. © 2014 Wiley Periodicals, Inc.

  2. Heart rate, ejection duration and subendocardial viability ratio in patients with rheumatoid arthritis as compared to controls.

    Science.gov (United States)

    Pieringer, Herwig; Brummaier, Tobias; Schmid, Michael; Pichler, Max; Hayat-Khayyati, Avida; Ebner, Stefan; Biesenbach, Georg; Pohanka, Erich

    2014-01-01

    Rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity and mortality. In the general population, an increased heart rate is associated with increased mortality. Only a few studies have investigated heart rate in RA patients and compared the results with patients that do not have RA (n-RA). Therefore, little is known as to whether an increased heart rate, at least in part, could explain the increased mortality found in RA patients. The aim of the present study was to investigate whether heart rate is increased in RA patients. In this cross-sectional study, heart rate was determined in a total of 282 patients (131 RA, 151 n-RA). In addition, non-invasive pulse wave analysis of the radial artery was performed to determine cardiac ejection duration using the Sphygmocor apparatus. Furthermore, the subendocardial viability ratio (SEVR), a marker of cardiac workload, was investigated, whereby higher values indicate a more favorable supply/demand relationship for the myocardium. Patients using chronotropic drugs were not included in the study. Heart rate was virtually the same in RA patients (71.9 ± 11.2 beats/min [bpm]) as compared with controls (72.3 ± 11.7 bpm; P > 0.05). Also SEVR (RA 144 ± 25% vs. n-RA 147 ± 27%; P > 0.05) and ejection duration (RA 321 ± 24 ms vs. n-RA 318 ± 24 ms; P > 0.05) were comparable between the groups. It could not be shown that heart rate in RA patients differs significantly from heart rate in controls. Therefore, heart rate does not appear to explain or contribute to the increased cardiovascular risk found in RA patients. © 2013 The Authors International Journal of Rheumatic Diseases © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  3. Urinary liver-type fatty acid-binding protein is associated with subendocardial viability ratio in middle- and older-aged adults.

    Science.gov (United States)

    Kosaki, Keisei; Kamijo-Ikemori, Atsuko; Sugaya, Takeshi; Tanahashi, Koichiro; Kumagai, Hiroshi; Sawano, Yuriko; Akazawa, Nobuhiko; Osuka, Yosuke; Tanaka, Kiyoji; Kimura, Kenjiro; Shibagaki, Yugo; Maeda, Seiji

    2017-09-05

    To identify one of the physiological underlying mechanisms of the predictive effects of urinary liver-type fatty acid-binding protein (L-FABP) for the onset of cardiovascular disease (CVD), we investigated the relationship between urinary L-FABP levels and subendocardial viability ratio (SEVR), a marker of myocardial perfusion, in middle- and older-aged adults. This was a cross-sectional study of 249 middle- and older-aged adults (aged 46-83 years). We measured urinary L-FABP levels and central hemodynamic parameters, including SEVR, calculated by pulse wave analysis using an applanation tonometry. In the participants stratified in accordance with the tertiles of urinary L-FABP levels, SEVR decreased in a stepwise fashion with increasing tertiles (p < 0.001). Furthermore, this association remains significant after the consideration of various confounders. On the contrary, urinary albumin levels were not independently related with SEVR. Our results demonstrated that urinary L-FABP levels were independently associated with the SEVR of the middle- and older-aged adults. This result suggests that the increase in urinary L-FABP levels even within the normal range might be related to the decrease in myocardial perfusion (SEVR).

  4. Extreme-Dipper Profile, Increased Aortic Stiffness, and Impaired Subendocardial Viability in Hypertension.

    Science.gov (United States)

    Amah, Guy; Ouardani, Rahma; Pasteur-Rousseau, Adrien; Voicu, Sebastian; Safar, Michel E; Kubis, Nathalie; Bonnin, Philippe

    2017-04-01

    In treated hypertensives, extreme-dippers with stable coronary artery disease (CAD) exhibit more severe nighttime cardiac ischemia than dippers. After excluding confounding factors such as diabetes, CAD or chronic kidney disease (CKD), we assessed whether subendocardial viability, determined by the Buckberg index, was more significantly impaired in extreme-dippers than in dippers. Two hundred thirteen consecutive treated hypertensives (156 dippers, 57 extreme-dippers), were included. After 24-hour ambulatory blood pressure (BP) monitoring, patients underwent radial applanation tonometry (with determination of: subendocardial viability ratio [SEVR], central augmentation index [AIx], and pulse pressure amplification [PPamp]), carotid-femoral pulse wave velocity (cfPWV) measurement, and cycle ergometer stress testing. Extreme-dippers showed higher cfPWV (8.99 ± 2.16 vs. 8.29 ± 1.69 m/s, P = 0.014), higher AIx (29.7 ± 9.4 vs. 26.4 ± 10.4%, P = 0.042), lower PPamp (1.22 ± 0.14 vs. 1.30 ± 0.15, P subendocardial viability compared to dippers. Extreme-dipper hypertensive patients, women in particular, may have a significantly higher risk of silent myocardial ischemia, thus justifying systematic screening.

  5. The role of inflammation, the autonomic nervous system and classical cardiovascular disease risk factors on subendocardial viability ratio in patients with RA: a cross-sectional and longitudinal study.

    Science.gov (United States)

    Sandoo, Aamer; Protogerou, Athanassios D; Hodson, James; Smith, Jacqueline P; Zampeli, Evi; Sfikakis, Petros P; Kitas, George D

    2012-11-28

    Evidence indicates that rheumatoid arthritis (RA) patients have increased susceptibility to myocardial ischaemia that contributes to myocardial infarction. The subendocardial viability ratio (SEVR) can be measured using pulse wave analysis and reflects myocardial oxygen supply and demand. The objective of the present study was to examine specific predictors of SEVR in RA patients, with a specific focus on inflammation and classical cardiovascular disease (CVD) risk factors. Two patient cohorts were included in the study; a primary cohort consisting of 220 RA patients and a validation cohort of 127 RA patients. All patients underwent assessment of SEVR using pulse wave analysis. Thirty-one patients from the primary cohort who were about to start anti-inflammatory treatment were prospectively examined for SEVR at pretreatment baseline and 2 weeks, 3 months and 1 year following treatment. Systemic markers of disease activity and classical CVD risk factors were assessed in all patients. The SEVR (mean ± standard deviation) for RA in the primary cohort was 148 ± 27 and in the validation cohort was 142 ± 25. Regression analyses revealed that all parameters of RA disease activity were associated with SEVR, along with gender, blood pressure and heart rate. These findings were the same in the validation cohort. Analysis of longitudinal data showed that C-reactive protein (P < 0.001), erythrocyte sedimentation rate (P < 0.005), Disease Activity Score in 28 joints (P < 0.001), mean blood pressure (P < 0.005) and augmentation index (P < 0.001) were significantly reduced after commencing anti-TNFα treatment. Increasing C-reactive protein was found to be associated with a reduction in SEVR (P = 0.02) and an increase in augmentation index (P = 0.001). The present findings reveal that the SEVR is associated with markers of disease activity as well as highly prevalent classical CVD risk factors in RA, such as high blood pressure and diabetes. Further prospective studies are

  6. Factors associated with subendocardial ischemia risk in patients on hemodialysis

    National Research Council Canada - National Science Library

    Silva, Bruno Caldin da; Sanjuan, Adriano; Costa-Hong, Valéria; Reis, Luciene dos; Graciolli, Fabiana; Consolim-Colombo, Fernanda; Bortolotto, Luiz Aparecido; Moyses, Rosa Maria Affonso; Elias, Rosilene Motta

    2016-01-01

    ..., such vascular evaluation in patients on hemodialysis has not been extensively studied. Methods: In this cross-sectional study, hemodialysis patients were submitted to flow-mediated dilation, subendocardial viability ratio...

  7. Pathophysiology of subendocardial ischaemia.

    Science.gov (United States)

    Hoffman, J I; Buckberg, G D

    1975-01-01

    Most forms of heart disease cause myocardial damage which often is confined to the deep (subendocardial) layer of left ventricular muscle. Much clinical and experimental evidence suggests that subendocardial muscle is prone to ischaemic damage, and a physiological mechanism for this vulnerability is described. Furthermore, experiments suggest that pressures recorded at cardiac catheterization can help to assess if there is subendocardial ischaemia in a variety of lesions in man. PMID:1109663

  8. Subendocardial ischemia in hypertrophic cardiomyopathy.

    Science.gov (United States)

    Kawasaki, Tatsuya; Sugihara, Hiroki

    2014-02-01

    Hypertrophic cardiomyopathy (HCM) patients often develop subendocardial ischemia in the left ventricle without atherosclerotic coronary stenosis. Myocardial ischemia plays an important role in the pathophysiology of HCM, but diagnostic techniques for the detection of subendocardial ischemia have not been widely available. We developed specific techniques to quantify subendocardial ischemia on stress scintigraphy, and have compared the results with various clinical features in patients with HCM. This article reviews our understanding of subendocardial ischemia in HCM based on more than 20 years of experience. Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  9. Factors associated with subendocardial ischemia risk in patients on hemodialysis

    Directory of Open Access Journals (Sweden)

    Bruno Caldin da Silva

    Full Text Available Abstract Introduction: Bone metabolism disorder (BMD and vascular dysfunction contribute to excess cardiovascular mortality observed in hemodialysis patients. Vascular dysfunction, a new marker of atherosclerosis, can play a role in this risk. Even though associated with higher mortality in the general population, such vascular evaluation in patients on hemodialysis has not been extensively studied. Methods: In this cross-sectional study, hemodialysis patients were submitted to flow-mediated dilation, subendocardial viability ratio (SEVR and ejection duration index assessment, in order to estimate the impact of BMD markers on vascular dysfunction. Results: A matched cohort of patients with (n = 16 and without (n = 11 severe secondary hyperparathyroidism (SHPT was studied. Additionally, time spent under severe SHPT was also evaluated. Patients with severe SHPT had lower SEVR and higher ejection duration index, indicating higher cardiovascular risk. Lower SEVR was also associated to diastolic blood pressure (r = 0.435, p = 0.049, serum 25-Vitamin-D levels (r = 0.479, p = 0.028 and to more time spent under severe secondary hyperparathyroidism (SHPT, defined as time from PTH > 500pg/ml until parathyroidectomy surgery or end of the study (r = -0.642, p = 0.027. In stepwise multiple regression analysis between SEVR and independent variables, lower SEVR was independently associated to lower serum 25-Vitamin-D levels (p = 0.005, female sex (p = 0.012 and more time spent under severe SHPT (p = 0.001 in a model adjusted for age, serum cholesterol, and blood pressure (adjusted r² = 0.545, p = 0.001. Conclusion: Subendocardial perfusion was lower in patients with BMD, reflecting higher cardiovascular risk in this population. Whether early parathyroidectomy in the course of kidney disease could modify such results still deserves further investigation.

  10. Hyperthyroidism affects arterial stiffness, plasma NT-pro-B-type natriuretic peptide levels, and subendocardial perfusion in patients with Graves' disease.

    Science.gov (United States)

    Bodlaj, Gerd; Pichler, Robert; Brandstätter, Walter; Hatzl-Griesenhofer, Margit; Maschek, Wilhelmine; Biesenbach, Georg; Berg, Jörg

    2007-01-01

    Arterial stiffness is thought to play a critical role in the pathogenesis of cardiovascular events, and in hyperthyroidism increased cardiovascular event rates have been reported. To investigate markers of systemic arterial stiffness, volume homeostasis, and subendocardial perfusion and its interrelationship in patients with Graves' disease (GD) in hyperthyroidism and euthyroidism. Aortic augmentation index (AIx@75) as a measure of systemic arterial stiffness and subendocardial viability ratio (SEVR) as a surrogate measure of subendocardial perfusion were assessed by applanation tonometry in 59 patients with GD in hyperthyroidism and euthyroidism, and measurements were compared to plasma levels of NT-pro-B-type natriuretic peptide (NT-ProBNP). AIx@75 and NT-ProBNP levels were significantly increased in hyperthyroidism compared to euthyroidism and were positively correlated with each other. SEVR was significantly decreased in hyperthyroidism compared to euthyroidism, mainly due to increased heart rates as shown by the heart rate-corrected SEVR75. In hyperthyroidism, patients with GD exhibited increased systemic arterial stiffness, paralleled by increased levels of NT-ProBNP, a marker of volume overload. The decreased subendocardial perfusion in hyperthyroidism seemed to be mainly due to increased heart rates. The observed unfavorable hemodynamic alterations in hyperthyroidism may serve to explain increased cardiovascular event rates in patients with GD.

  11. Diagnostic performance of ultrasonic tissue characterization for subendocardial ischaemia in patients with hypertrophic cardiomyopathy.

    Science.gov (United States)

    Kawasaki, Tatsuya; Yamano, Michiyo; Sakai, Chieko; Harimoto, Kuniyasu; Miki, Shigeyuki; Kamitani, Tadaaki; Sugihara, Hiroki

    2013-08-01

    Hypertrophic cardiomyopathy (HCM) patients often develop left--ventricular subendocardial ischaemia, a cause of chest symptoms, despite normal epicardial coronary arteries. The aim of this study was to examine whether ultrasonic tissue characterization or late gadolinium enhancement on cardiac magnetic resonance imaging can detect subendocardial ischaemia in patients with HCM. Subendocardial ischaemia was quantified on exercise Tc-99m tetrofosmin myocardial scintigraphy in 29 non-obstructive HCM patients with asymmetric septal hypertrophy. Ultrasonic tissue characterization using cyclic variation of integrated backscatter (CV-IB) and late gadolinium enhancement on cardiac magnetic resonance imaging were analysed separately in the right halves and the left halves of the ventricular septum in relation to subendocardial ischaemia. Subendocardial ischaemia was identified in 17 (59%) patients. The ratio of CV-IB in the right-to-left halves of the ventricular septum was significantly higher in patients with subendocardial ischaemia (1.19 ± 0.10) than those without (0.84 ± 0.10, P = 0.04). The optimal cutoff for the detection of subendocardial ischaemia was the ratio of CV-IB >1.0, with a sensitivity of 80%, specificity of 71%, and accuracy of 76%. On the other hand, late gadolinium enhancement was not associated with subendocardial ischaemia in our cohort. Ultrasonic tissue characterization using CV-IB separately in the right and left halves of the ventricular septum, but not late gadolinium enhancement on magnetic resonance imaging, provided useful information in detecting subendocardial ischaemia in patients with HCM. Ultrasonic tissue characterization may be useful in selecting patients who will benefit from medications to relieve chest symptoms.

  12. Assessment of subendocardial contractile function in aortic stenosis: a study using speckle tracking echocardiography.

    Science.gov (United States)

    van Dalen, Bas M; Tzikas, Apostolos; Soliman, Osama I I; Heuvelman, Helena J; Vletter, Wim B; Ten Cate, Folkert J; Geleijnse, Marcel L

    2013-03-01

    Angina and an electrocardiographic strain pattern are potential manifestations of subendocardial ischemia in aortic stenosis (AS). Left ventricular (LV) twist is known to increase proportionally to the severity of AS, which may be a result of loss of the inhibiting effect of the subendocardial fibers due to subendocardial dysfunction. It has also been shown that the ratio of LV twist to circumferential shortening of the endocardium (twist-to-shortening ratio [TSR]) is a reliable parameter of subendocardial dysfunction. The aim of this study was to investigate whether these markers are increased in AS patients with angina and/or electrocardiographic strain. The study comprised 60 AS patients with an aortic valve area 50%, and 30 healthy-for age and gender matched-control subjects. LV rotation parameters were determined by speckle tracking echocardiography. Comparison of patients without angina and strain (n = 22), with either angina or strain (n = 28), and with both angina and strain (n = 8), showed highest peak systolic LV apical rotation, peak systolic LV twist, and TSR, in patients with more signs of subendocardial ischemia. In a multivariate linear regression model, only severity of AS and the presence of angina and/or strain could be identified as independent predictors of peak systolic LV twist and TSR. Peak systolic LV twist and TSR are increased in AS patients and related to the severity of AS and symptoms (angina) or electrocardiographic signs (strain) compatible with subendocardial ischemia. © 2013, Wiley Periodicals, Inc.

  13. Acute myocardial infarct extension into a previously preserved subendocardial region at risk in dogs and patients.

    Science.gov (United States)

    Forman, R; Cho, S; Factor, S M; Kirk, E S

    1983-01-01

    In this study we quantitated the region of preserved myocardium between a subendocardial myocardial infarct (SEMI) and the endocardium in dogs and determined whether this preserved zone was within the region at risk and whether infarct extension could occur in this region. We also evaluated whether a similar subendocardial region exists in patients with SEMI. A 40-minute temporary occlusion of the left anterior descending coronary artery (LAD) in eight dogs resulted in a 35 +/- 5% transmural infarct with 8 +/- 1% subendocardial preservation as assessed by point-counting of the histologic specimens. In vivo perfusion of coronary vessels with Microfil showed that this preserved subendocardial zone was within the region at risk. The preserved subendocardial zone had significantly fewer cell layers in the dogs ventilated with room air than in dogs ventilated with 100% oxygen (8 +/- 4 vs 19 +/- 4, p less than 0.001), which suggests that diffusion from the ventricular cavity was the mechanism of cell preservation. In contrast, the inspired oxygen concentration did not influence the size of the SEMI. Reocclusion of the LAD for 24 hours in an additional eight dogs, 1 week after a SEMI had been created by a 40-minute temporary occlusion, resulted in both subendocardial and subepicardial extension involving 5 +/- % and 29 +/- 9%, respectively, of the transmural myocardium at the infarct center. Subendocardial infarct extension of a similar dimension to that in dogs ventilated on 100% oxygen was observed in postmortem material from eight patients with infarct extension. The preserved layers of subendocardium presumably receive sufficient nutrients from the ventricular cavity to maintain the viability of this region during temporary, but not permanent, reduction of blood supply from the coronary arteries.

  14. Population viability at extreme sex-ratio skews produced by temperature-dependent sex determination.

    Science.gov (United States)

    Hays, Graeme C; Mazaris, Antonios D; Schofield, Gail; Laloë, Jacques-Olivier

    2017-02-08

    For species with temperature-dependent sex determination (TSD) there is the fear that rising temperatures may lead to single-sex populations and population extinction. We show that for sea turtles, a major group exhibiting TSD, these concerns are currently unfounded but may become important under extreme climate warming scenarios. We show how highly female-biased sex ratios in developing eggs translate into much more balanced operational sex ratios so that adult male numbers in populations around the world are unlikely to be limiting. Rather than reducing population viability, female-biased offspring sex ratios may, to some extent, help population growth by increasing the number of breeding females and hence egg production. For rookeries across the world (n = 75 sites for seven species), we show that extreme female-biased hatchling sex ratios do not compromise population size and are the norm, with a tendency for populations to maximize the number of female hatchlings. Only at extremely high incubation temperature does high mortality within developing clutches threaten sea turtles. Our work shows how TSD itself is a robust strategy up to a point, but eventually high mortality and female-only hatchling production will cause extinction if incubation conditions warm considerably in the future. © 2017 The Author(s).

  15. Assessment of subendocardial structure and function.

    Science.gov (United States)

    Stanton, Tony; Marwick, Thomas H

    2010-08-01

    The combination of high energy expenditure and the borderline adequacy of perfusion make the subendocardium uniquely vulnerable to injury. Selective subendocardial involvement is usually a marker of subclinical disease. Technical advances in new noninvasive imaging modalities, especially in spatial resolution, now permit qualitative and quantitative assessment of subendocardial structure, function, and perfusion. Many newer techniques have the potential to provide superior prognostic information to current standard assessment methods. This review describes the contemporary capabilities of multiple imaging modalities for assessment of the subendocardium, and seeks to guide the clinician regarding the information and technical deficiencies of each modality.

  16. Alteration in subendocardial and subepicardial myocardial strain in patients with aortic valve stenosis: an early marker of left ventricular dysfunction?

    Science.gov (United States)

    Hyodo, Eiichi; Arai, Kotaro; Koczo, Agnes; Shimada, Yuichi J; Fujimoto, Kohei; Di Tullio, Marco R; Homma, Shunichi; Gillam, Linda D; Hahn, Rebecca T

    2012-02-01

    It has been suggested that myocardial systolic impairment may not be accurately detected by the evaluation of endocardial excursion alone. The aim of this study was to test the hypothesis that changes in left ventricular (LV) subendocardial and subepicardial strain are sensitive markers of severity of aortic stenosis (AS) and LV function in patients with AS. Transthoracic echocardiography was performed in 73 consecutive patients with AS who had preserved systolic function and in 20 controls. Longitudinal strain, subendocardial radial strain, subepicardial radial strain, and transmural radial strain were measured using LV apical and short-axis images. The 73 patients enrolled in this study were classified according to AS severity: mild (n = 10), moderate (n = 15), or severe (n = 48). Although transmural and subepicardial radial strain showed similar values in all groups, subendocardial radial strain and longitudinal strain could differentiate mild or moderate AS from severe AS. Only the ratio of subendocardial to subepicardial radial strain (the bilayer ratio) decreased significantly as the severity of AS increased. Bilayer ratio showed weak correlations with LV ejection fraction (r = 0.37) and E/E' ratio (r = -0.33) and moderate correlations with LV mass (r = -0.55) and aortic valve area (r = 0.71). Moreover, bilayer ratio was independently associated with AS severity (P = .001). In 21 patients who underwent aortic valve replacement, subendocardial radial strain and bilayer ratio increased 7 days after surgery, whereas other echocardiographic parameters of LV function showed no improvement. Bilayer ratio can reliably differentiate patients with varying degrees of AS severity and is a sensitive marker of LV function. These findings suggest that the evaluation of subendocardial and subepicardial radial strain might be a novel method for assessing LV mechanics in patients with AS. Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All

  17. Assessment of Radiobiological α/β Ratio in Lung Cancer and Fibroblast Cell Lines Using Viability Assays.

    Science.gov (United States)

    Karagounis, Ilias V; Skourti, Eleni K; Liousia, Maria V; Koukourakis, Michael I

    2017-01-01

    Altered fractionation is an area of intense clinical research in radiation oncology. Estimation of the α/β ratio of individual carcinomas after establishment of primary cell cultures from tumor biopsies may prove of importance in the individualization of radiotherapy schemes. Here we proposed a simple method to estimate the α/β ratio in cultured cell lines (two lung carcinomas: A549 and H1299; one lung fibroblast cell line: MRC5), using viability assays. For the A549 cell line, the α/β ratio ranged from 14-25 Gy, for H1299 from 11-43 Gy and for the MRC5 fibroblast cell line this was far lower, ranging from 0.69 to 6 Gy. The α/β ratio decreased when extracted from comparisons of lower dose per fraction schemes. The α/β ratio of a cell line can be easily defined after simple viability/dose fractionation experiments. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  18. Factors associated with subendocardial ischemia risk in patients on hemodialysis.

    Science.gov (United States)

    Silva, Bruno Caldin da; Sanjuan, Adriano; Costa-Hong, Valéria; Reis, Luciene Dos; Graciolli, Fabiana; Consolim-Colombo, Fernanda; Bortolotto, Luiz Aparecido; Moyses, Rosa Maria Affonso; Elias, Rosilene Motta

    2016-01-01

    Bone metabolism disorder (BMD) and vascular dysfunction contribute to excess cardiovascular mortality observed in hemodialysis patients. Vascular dysfunction, a new marker of atherosclerosis, can play a role in this risk. Even though associated with higher mortality in the general population, such vascular evaluation in patients on hemodialysis has not been extensively studied. In this cross-sectional study, hemodialysis patients were submitted to flow-mediated dilation, subendocardial viability ratio (SEVR) and ejection duration index assessment, in order to estimate the impact of BMD markers on vascular dysfunction. A matched cohort of patients with (n = 16) and without (n = 11) severe secondary hyperparathyroidism (SHPT) was studied. Additionally, time spent under severe SHPT was also evaluated. Patients with severe SHPT had lower SEVR and higher ejection duration index, indicating higher cardiovascular risk. Lower SEVR was also associated to diastolic blood pressure (r = 0.435, p = 0.049), serum 25-Vitamin-D levels (r = 0.479, p = 0.028) and to more time spent under severe secondary hyperparathyroidism (SHPT), defined as time from PTH > 500pg/ml until parathyroidectomy surgery or end of the study (r = -0.642, p = 0.027). In stepwise multiple regression analysis between SEVR and independent variables, lower SEVR was independently associated to lower serum 25-Vitamin-D levels (p = 0.005), female sex (p = 0.012) and more time spent under severe SHPT (p = 0.001) in a model adjusted for age, serum cholesterol, and blood pressure (adjusted r² = 0.545, p = 0.001). Subendocardial perfusion was lower in patients with BMD, reflecting higher cardiovascular risk in this population. Whether early parathyroidectomy in the course of kidney disease could modify such results still deserves further investigation. Distúrbios do metabolismo ósseo (DMO) e alterações da função vascular contribuem para a elevada mortalidade de pacientes em hemodiálise. A disfunção vascular

  19. Stenosis differentially affects subendocardial and subepicardial arterioles in vivo

    NARCIS (Netherlands)

    Merkus, D.; Vergroesen, I.; Hiramatsu, O.; Tachibana, H.; Nakamoto, H.; Toyota, E.; Goto, M.; Ogasawara, Y.; Spaan, J. A.; Kajiya, F.

    2001-01-01

    The presence of a coronary stenosis results primarily in subendocardial ischemia. Apart from the decrease in coronary perfusion pressure, a stenosis also decreases coronary flow pulsations. Applying a coronary perfusion system, we compared the autoregulatory response of subendocardial (n = 10) and

  20. Effect of acute subendocardial ischemia on ventricular refractory periods.

    Science.gov (United States)

    Ma, Longle; Wang, Lexin

    2007-01-01

    To investigate the impact of acute subendocardial ischemia on the dispersion of ventricular refractory periods. Acute subendocardial ischemia was induced in sheep by partial ligation of the left circumflex coronary artery and rapid pacing of the left atrium. The ventricular effective refractory period (ERP) was measured in five areas of the left ventricle by a programmed premature stimulation technique. The average ERP and ERP dispersion remained unchanged in the control group (n=5, P>0.05). In the study group (n=5), the ERP was shortened following subendocardial ischemia. ERP dispersion decreased significantly from 48+/-9 ms to 36+/-13 ms 30 min after the ischemia (P=0.02). There was neither spontaneous nor stimulation-induced ventricular arrhythmia after ischemia. Acute subendocardial ischemia leads to a homogenous reduction of ventricular ERP. This may partially explain why subendocardial ischemia is associated with a low incidence of ventricular arrhythmia.

  1. Molybdate:sulfate ratio affects redox metabolism and viability of the dinoflagellate Lingulodinium polyedrum

    Energy Technology Data Exchange (ETDEWEB)

    Barros, M.P., E-mail: marcelo.barros@cruzeirodosul.edu.br [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Hollnagel, H.C. [Pós-Graduação, Faculdade Mario Schenberg, 06710500 Cotia, SP (Brazil); Glavina, A.B. [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Soares, C.O. [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Department of Biochemistry, Instituto de Química, Universidade de São Paulo (IQ-USP), São Paulo (Brazil); Ganini, D. [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709 (United States); Dagenais-Bellefeuille, S.; Morse, D. [Departement de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Université de Montréal, Montreal, QC H1X 2B2 (Canada); Colepicolo, P. [Department of Biochemistry, Instituto de Química, Universidade de São Paulo (IQ-USP), São Paulo (Brazil)

    2013-10-15

    Highlights: •Molybdenum (Mo) is a key micronutrient for nitrogen and redox metabolism in many microalgae. •Molybdate and (more abundant) sulfate anions compete for uptake, although proper mechanism is still obscure. •Higher concentrations of molybdate in culture medium diminish sulfur content in L. polyedrum. •Mo toxicity was monitored as a function of [Mo]:[sulfate] ratios in L. polyedrum and was linked to oxidative stress. •Induction of xanthine oxidase activity and/or depletion of thiol-dependent antioxidants are suggested as plausible mechanisms to explain Mo toxicity in dinoflagellates. -- Abstract: Molybdenum is a transition metal used primarily (90% or more) as an additive to steel and corrosion-resistant alloys in metallurgical industries and its release into the environment is a growing problem. As a catalytic center of some redox enzymes, molybdenum is an essential element for inorganic nitrogen assimilation/fixation, phytohormone synthesis, and free radical metabolism in photosynthesizing species. In oceanic and estuarine waters, microalgae absorb molybdenum as the water-soluble molybdate anion (MoO{sub 4}{sup 2−}), although MoO{sub 4}{sup 2−} uptake is thought to compete with uptake of the much more abundant sulfate anion (SO{sub 4}{sup 2−}, approximately 25 mM in seawater). Thus, those aspects of microalgal biology impacted by molybdenum would be better explained by considering both MoO{sub 4}{sup 2−} and SO{sub 4}{sup 2−} concentrations in the aquatic milieu. This work examines toxicological, physiological and redox imbalances in the dinoflagellate Lingulodinium polyedrum that have been induced by changes in the molybdate:sulfate ratios. We prepared cultures of Lingulodinium polyedrum grown in artificial seawater containing eight different MoO{sub 4}{sup 2−} concentrations (from 0 to 200 μM) and three different SO{sub 4}{sup 2−} concentrations (3.5 mM, 9.6 mM and 25 mM). We measured sulfur content in cells, the activities of

  2. Subendocardial ischaemia in patients with discrete subvalvar aortic stenosis.

    Science.gov (United States)

    Cassel, G A; Benjamin, J D; Lakier, J B

    1978-01-01

    The evidence for subendocardial ischaemia was studied in 12 patients with discrete subvalvar aortic stenosis. Symptomatology, electrocardiographic criteria, and pressure difference across the left ventricular outflow tract were compared with the subendocardial flow index (diastolic pressure time index systolic pressure time index). All symptomatic patients had a large pressure difference and abnormal index, but 4 asymptomatic patients had pressure differences greater than 60 mmHg and a low index. One of these 4 patients had a normal resting electrocardiogram. In patients with borderline accepted indications for surgery, calculation of the subendocardial flow index may be an additional useful variable in the timing of surgery. PMID:565643

  3. Acute subendocardial ischaemia leads to homogenous prolongation in ventricular repolarization.

    Science.gov (United States)

    Ma, Long-le; Wang, Le-Xin

    2007-01-01

    Acute transmural ischaemia often shortens ventricular repolarization and increases repolarization dispersion, leading to life threatening ventricular arrhythmias in animal models and human subjects. Experimental studies and clinical observations have shown that acute subendocardial ischaemia rarely causes serious ventricular arrhythmia. We hypothesized that the different arrhythmia outcomes between transmural and subendocardial ischaemia are largely due to the homogenous prolongation in ventricular repolarization after acute subendocardial ischaemia. Further experimental studies on a subendocardial model are required to assess the changes in ventricular repolarization and its spatial dispersion, and to investigate the role of these changes in the pathogenesis of ventricular arrhythmias. These studies will facilitate our understanding on the mechanisms of life-threatening ventricular arrhythmias during acute myocardial ischaemia.

  4. Subendocardial ischemic myocardial lesions associated with severe coronary atherosclerosis.

    Science.gov (United States)

    Geer, J. C.; Crago, C. A.; Little, W. C.; Gardner, L. L.; Bishop, S. P.

    1980-01-01

    Morphologic changes in the subendocardial myocardium that appeared to be caused by severe, chronic subendocardial ischemia were studied in patients with fatal ischemic heart disease admitted to the Specialized Center of Research for Ischemic Heart Disease at the University of Alabama in Birmingham in the period 1970--1977. Thirteen patients were selected for this report on the basis that they had the lesions in the subendocardial myocardium we believe to have been caused by subendocardial ischemia and had no evidence of acute or remote myocardial infarction or other conditions that may have contributed to their terminal illness or death. Clinical findings were unstable angina, congestive heart failure, usually no increase in plasma enzymes indicative of myocardial damage, and electrocardiographic changes consistent with subendocardial ischemia. All 13 patients had 75% or greater stenosis of the three major coronary arteries; none had acute thrombotic or embolic coronary artery occlusion. The left ventricle in all cases was hypertrophied. The subendocardial myocardium showed circumferential pallor, hyperemia, or focal fibrosis without perceptible loss of volume in papillary muscles or trabeculae carneae. Microscopically, acute lesions showed one to two layers of preserved myofibers adjacent to the endocardium, vacuolar change in the deeper fibers, and focal areas of coagulation necrosis of variable size in the myocardium external to the fibers with vacuolar change. Coagulation necrosis was extensive in some cases and usually was not associated with infiltration of neutrophils. The repair reaction involved removal of necrotic sarcoplasm by mononuclear phagocytes, resulting in a reticular-appearing tissue without evidence of stromal collapse. Granulation tissue was not seen. Collagen fibers appeared to be deposited within the area of previous sarcolemmal sheaths. The distribution and morphology of subendocardial myocardial lesions associated with severe coronary

  5. Normal age-related changes in left ventricular function: Role of afterload and subendocardial dysfunction.

    Science.gov (United States)

    Parikh, Jehill D; Hollingsworth, Kieren G; Wallace, Dorothy; Blamire, Andrew M; MacGowan, Guy A

    2016-11-15

    In normal ageing, both vascular and ventricular properties change, and how these affect left ventricular function is not clear. 96 subjects (ages 20-79) without cardiovascular disease underwent cardiac magnetic resonance (MR) imaging for measurement of global function, diastolic function (E/A ratio), MR tagging for measurement of torsion to shortening ratio (TSR, ratio of epicardial torsion to endocardial circumferential shortening, with increase in TSR suggesting subendocardial dysfunction relative to the subepicardium), and phase contrast MR imaging measurement of central aortic pulse wave velocity (PWV). The Vicorder device was used to measure carotid to femoral PWV. Univariate correlations established that the 4 principal age-related changes in the left ventricular function were: 1) diastolic function: E/A ratio (r: -0.61, psubendocardial dysfunction, has a significant role in reductions of cardiac output and end-diastolic volume index. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  6. Vascular calcification and subendocardial ischemia in hemodialysis patients: a new morpho-functional score to assess cardiovascular risk: the Solofra score.

    Science.gov (United States)

    Sirico, Maria L; Di Micco, Lucia; De Blasio, Antonella; Di Iorio, Biagio

    2014-01-01

    ESRD (end-stage renal disease) patients have a high cardiovascular mortality risk. A morphofunctional approach of vascular calcifications and myocardial perfusion is needed for the management of ESRD patients. We used SEVR (sub-endocardial viability ratio) and Kauppila score from the dialysis population of the Independent study to create a new morpho-functional score to assess cardiovascular risk in this population (the Solofra score). 184 patients were followed-up for 36 months. A side lumbar X-ray was performed to assess vascular calcifications of lumbar aorta using the Kauppila score. Central aortic pressure and pulse velocity wave (PWV) were assessed at the carotid artery site. Myocardial perfusion was estimated with SEVR. Independent risk mortality factors were identified with univariate regression analysis (p<0.01); significance was defined as p<0.05. Kauppila score was 13±10(range 0-24); PWV was 9.5±4 m/sec; basal SEVR was 1.3±0.9. We observed an improvement of ROC curves for SEVR and Kauppila score together compared to the ones for SEVR or Kauppila score alone. A quantitative analysis of vascular calcifications should be associated to a qualitative evaluation of arterial damage to better estimate cardiovascular mortality risk of ESRD patients. Further studies are needed to verify our hypothesis.

  7. Impaired subendocardial wall thickening and post-systolic shortening are signs of critical myocardial ischemia in patients with flow-limiting coronary stenosis.

    Science.gov (United States)

    Ishizu, Tomoko; Seo, Yoshihiro; Baba, Masako; Machino, Tomoko; Higuchi, Haruhiko; Shiotsuka, Junji; Noguchi, Yuichi; Aonuma, Kazutaka

    2011-01-01

    The early diagnosis of myocardial ischemia is still challenging. The aim of the present study was to determine whether subendocardial hypokinesis and post-systolic contraction could be early markers of myocardial ischemia. Thirty-one consecutive patients with flow-limiting severe coronary stenosis but without visually abnormal left ventricular wall motion underwent quantitative echocardiography. Myocardial strain was measured using layer-by-layer analysis in severely hypoperfused segments. Radial strain (RS) was measured in the subendocardial, subepicardial, and total wall (innerRS, outerRS, and totalRS, respectively). Circumferential strain (CS) was also measured as 3 separate layers: subendocardial, mid-layer, and subepicardial layers (innerCS, midCS, and outerCS, respectively). Post-systolic shortening (PSS) was defined as the peak strain after end systole, and post-systolic strain index (PSI) was calculated as PSS divided by end-systolic strain. TotalRS was similar between ischemic and normally perfused segments, but innerRS and inner/outer RS ratio were significantly smaller in the ischemic segments than in corresponding segments in healthy subjects. Receiver operating characteristic analysis identified an optimum cut-off for PSI of 0.6. The combined criteria of inner/outer RS ratio 0.6 achieved 95% specificity for the presence of flow-limiting stenosis. Combined assessment of both subendocardial contractile impairment and PSS is very useful in identifying a severely hypoperfused left ventricular wall even without visual wall motion abnormality.

  8. The feasibility of the initial postsystolic to systolic strain rate ratio as a predictor of the viability of ischemic myocardium with acute myocardial infarction.

    Science.gov (United States)

    Park, Soon Chang; Kang, Ki-Woon; Yoon, Hyeon Soo; Myung, Jin Cheol; Choi, Yu Jeong; Park, Sang Hyun; Jung, Kyung Tae; Chin, Jung Yeon

    2014-08-01

    Investigations of a strain index for the viability of ischemic myocardium with acute myocardial infarction (AMI) have been challenging. Therefore, the aim of this study was to evaluate patients with AMI to determine an optimal strain index for predicting the viability of ischemic myocardium. A total of 57 patients with AMI were assessed according to two-dimensional (2D) speckle tracking imaging strain and strain rate (SR), measured during the acute phase before urgent revascularization and at a 1-year follow-up postrevascularization. During the acute phase, all the myocardial segments were classified according to the acute end-systolic strain (Ses) values as normal (Ses ≤ -13%), hypocontractile (-13% -7%). At the 1-year follow-up, we reassessed the recovery of the segments with a severe contractile abnormality. The viability of these segments was defined as an improved Ses (≤ -7%) at follow-up postrevascularization. The Ses values, postsystolic strain index (PSI), and SR values were significantly better in the viable segments than in the nonviable segments at both the acute phase and at follow-up (P < 0.001). The initial postsystolic to systolic SR ratio (SRps/SRs) had the best area under the curve (AUC = 0.897). In addition, a cutoff value of 0.6 predicted recovery from a severe contractile abnormality with a sensitivity of 75% and a specificity of 88%. The initial SRps/SRs ratio identified the viability of ischemic myocardium with AMI; therefore, this novel index may be clinically useful in the treatment of patients with AMI. © 2013, Wiley Periodicals, Inc.

  9. Subendocardial fibrosis in left ventricular hypertrabeculation-cause or consequence?

    Science.gov (United States)

    Ker, J; Du Toit-Prinsloo, L; Van Heerden, W F P; Saayman, G

    2011-02-02

    Left ventricular noncompaction has been classified as a primary cardiomyopathy with a genetic origin. This condition is morphologically characterized by a thickened, two-layered myocardium with numerous prominent trabeculations and deep, intertrabecular recesses. Recently, it has become clear that these pathological characteristics extend across a continuum with left ventricular hypertrabeculation at one end of the spectrum.The histological findings include areas of interstitial fibrosis.We present a case of left ventricular hypertrabeculation which presented as sudden infant death syndrome. Histologically areas of subendocardial fibrosis was prominent and we propose that this entity may be a hidden cause of arrhythmic death in some infants presenting as sudden infant death syndrome., with areas of subendocardial fibrosis as possible arrhythmogenic foci.

  10. Endothelial-dependent vasodilators preferentially increase subendocardial blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Pelc, L.R.; Gross, G.J.; Warltier, D.C.

    1986-03-05

    Interference with arachidonic acid metabolism on the effect of acetylcholine (Ach) or arachidonic acid (AA) to preferentially increase subendocardial perfusion was investigated in anesthetized dogs. Hemodynamics, regional myocardial blood flow (MBF (ml/min/g):radioactive microspheres) and the left ventricular transmural distribution of flow (endo/epi) were measured. Intracoronary infusion of Ach (10 ..mu..g/min) and AA (585 ..mu..g/min) significantly (P < .05*) increased myocardial perfusion and selectively redistributed flow to the subendocardium (increased endo/epi) without changes in systemic hemodynamics. Inhibition of phospholipase A/sub 2/ by quinacrine (Q; 600 ..mu..g/min, ic) attenuated the increase in myocardial perfusion produced by Ach but not by AA and inhibited the redistribution of flow to the subendocardium. The present results suggest that endothelium-dependent vasodilators produce a preferential increase in subendocardial perfusion via a product of AA metabolism.

  11. Subendocardial hemorrhages in a case of extrapercardial cardiac tamponade: A possible mechanism of appearance

    National Research Council Canada - National Science Library

    Nikolic, Slobodan; Zivkovic, Vladimir

    2016-01-01

    Introduction. Subendocardial hemorrhages are grossly visible bleedings in the inner surface of the left ventricle, the interventricular septum, and the opposing papillary muscles and adjacent columnae carneae...

  12. MultiContrast Delayed Enhancement (MCODE) improves detection of subendocardial myocardial infarction by late gadolinium enhancement cardiovascular magnetic resonance: a clinical validation study.

    Science.gov (United States)

    Bandettini, W Patricia; Kellman, Peter; Mancini, Christine; Booker, Oscar Julian; Vasu, Sujethra; Leung, Steve W; Wilson, Joel R; Shanbhag, Sujata M; Chen, Marcus Y; Arai, Andrew E

    2012-11-30

    Myocardial infarction (MI) documented by late gadolinium enhancement (LGE) has clinical and prognostic importance, but its detection is sometimes compromised by poor contrast between blood and MI. MultiContrast Delayed Enhancement (MCODE) is a technique that helps discriminate subendocardial MI from blood pool by simultaneously providing a T2-weighted image with a PSIR (phase sensitive inversion recovery) LGE image. In this clinical validation study, our goal was to prospectively compare standard LGE imaging to MCODE in the detection of MI. Imaging was performed on a 1.5 T scanner on patients referred for CMR including a LGE study. Prospective comparisons between MCODE and standard PSIR LGE imaging were done by targeted, repeat imaging of slice locations. Clinical data were used to determine MI status. Images at each of multiple time points were read on separate days and categorized as to whether or not MI was present and whether an infarction was transmural or subendocardial. The extent of infarction was scored on a sector-by-sector basis. Seventy-three patients were imaged with the specified protocol. The majority were referred for vasodilator perfusion exams and viability assessment (37 ischemia assessment, 12 acute MI, 10 chronic MI, 12 other diagnoses). Forty-six patients had a final diagnosis of MI (30 subendocardial and 16 transmural). MCODE had similar specificity compared to LGE at all time points but demonstrated better sensitivity compared to LGE performed early and immediately before and after the MCODE (p = 0.008 and 0.02 respectively). Conventional LGE only missed cases of subendocardial MI. Both LGE and MCODE identified all transmural MI. Based on clinical determination of MI, MCODE had three false positive MI's; LGE had two false positive MI's including two of the three MCODE false positives. On a per sector basis, MCODE identified more infarcted sectors compared to LGE performed immediately prior to MCODE (p subendocardial MI's than LGE and

  13. MultiContrast Delayed Enhancement (MCODE improves detection of subendocardial myocardial infarction by late gadolinium enhancement cardiovascular magnetic resonance: a clinical validation study

    Directory of Open Access Journals (Sweden)

    Bandettini W Patricia

    2012-11-01

    Full Text Available Abstract Background Myocardial infarction (MI documented by late gadolinium enhancement (LGE has clinical and prognostic importance, but its detection is sometimes compromised by poor contrast between blood and MI. MultiContrast Delayed Enhancement (MCODE is a technique that helps discriminate subendocardial MI from blood pool by simultaneously providing a T2-weighted image with a PSIR (phase sensitive inversion recovery LGE image. In this clinical validation study, our goal was to prospectively compare standard LGE imaging to MCODE in the detection of MI. Methods Imaging was performed on a 1.5 T scanner on patients referred for CMR including a LGE study. Prospective comparisons between MCODE and standard PSIR LGE imaging were done by targeted, repeat imaging of slice locations. Clinical data were used to determine MI status. Images at each of multiple time points were read on separate days and categorized as to whether or not MI was present and whether an infarction was transmural or subendocardial. The extent of infarction was scored on a sector-by-sector basis. Results Seventy-three patients were imaged with the specified protocol. The majority were referred for vasodilator perfusion exams and viability assessment (37 ischemia assessment, 12 acute MI, 10 chronic MI, 12 other diagnoses. Forty-six patients had a final diagnosis of MI (30 subendocardial and 16 transmural. MCODE had similar specificity compared to LGE at all time points but demonstrated better sensitivity compared to LGE performed early and immediately before and after the MCODE (p = 0.008 and 0.02 respectively. Conventional LGE only missed cases of subendocardial MI. Both LGE and MCODE identified all transmural MI. Based on clinical determination of MI, MCODE had three false positive MI’s; LGE had two false positive MI’s including two of the three MCODE false positives. On a per sector basis, MCODE identified more infarcted sectors compared to LGE performed immediately prior

  14. CT detection of subendocardial fat in myocardial infarction.

    Science.gov (United States)

    Ahn, Sung Soo; Kim, Young-Jin; Hur, Jin; Lee, Hye-Jeong; Kim, Tae Hoon; Choe, Kyu Ok; Choi, Byoung Wook

    2009-02-01

    We sought to systemically analyze the characteristics of fat accumulation in patients with myocardial infarction (MI) relative to various clinical parameters. We included 161 patients (129 men, 32 women; mean age, 60.7 years) who had previously been diagnosed with MI and had undergone CT coronary angiography between February 2003 and April 2005. We analyzed the characteristics of myocardial fat, if present, and compared the clinical parameters of the patients with and those without myocardial fat. Myocardial fat was found in the subendocardial region in 36 (22.4%) patients with MI. In all cases, the myocardial fat was located in the subendocardial region and was typically detected in the left anterior descending artery territory (75%, n = 27). The mean attenuation value of myocardial fat was -29.6 HU on unenhanced CT. Myocardial fat was more frequently associated with a greater infarct age, milder coronary artery stenosis, and fewer number of diseased vessels. Patients with myocardial fat had more severe regional wall motion abnormalities on follow-up echocardiography. Age, sex, the presence of ST elevation or Q wave, elevated levels of cardiac enzymes, ejection fraction, and end-diastolic left ventricular dimension on follow-up echocardiography, as well as the presence of arrhythmia, were not significantly different between the two groups. Myocardial fat was detected in 22.4% of MI patients and was more frequently associated with a longer postinfarct period, milder coronary artery stenosis, fewer number of diseased vessels, and more severe regional wall motion abnormalities.

  15. Transmural Differences in Mechanical Properties of Isolated Subendocardial and Subepicardial Cardiomyocytes.

    Science.gov (United States)

    Khokhlova, A D; Iribe, G

    2016-11-01

    We studied the differences in twitch force of subendocardial and subepicardial cardiomyocytes isolated from mouse left ventricular wall at different preloads using an original single cell stretch method recently developed by us. Then, we used our mathematical models of subendocardial and subepicardial cells to predict underlying cellular mechanisms. Transmural differences in the amplitudes of active tension of subendocardial and subepicardial cardiomyocytes were revealed that could be related to the differences in cooperative end-to-end interaction between the neighboring regulatory units of the thin filament.

  16. Vagal enhancement linking abnormal blood pressure response and subendocardial ischemia in hypertrophic cardiomyopathy.

    Science.gov (United States)

    Kawasaki, Tatsuya; Sugihara, Hiroki

    2014-01-01

    An abnormal blood pressure response to exercise has been reported to be associated with left ventricular subendocardial ischemia in patients with hypertrophic cardiomyopathy (HCM), but the underlying mechanism remains unclear. We report a case of HCM with an abnormal blood pressure response and subendocardial ischemia, in which the analysis of heart rate variability revealed exercise-induced vagal enhancement. The present case highlights the possible mechanism linking abnormal blood pressure response and left ventricular subendocardial ischemia in patients with HCM. ©2013 Wiley Periodicals, Inc.

  17. Assessment of myocardial viability using multidetector computed tomography in patients with reperfused acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. [Department of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Choi, B.J. [Department of Cardiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Kang, D.K., E-mail: kdklsm@ajou.ac.kr [Department of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Sun, J.S. [Department of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of)

    2012-08-15

    Aim: To assess the prognostic value of 64-section multidetector computed tomography (MDCT) to predict follow-up myocardial dysfunction and functional recovery after reperfusion therapy in patients with acute myocardial infarction (MI) as defined by echocardiography. Materials and methods: After reperfusion therapy for acute MI, 71 patients underwent two-phase contrast-enhanced MDCT and follow-up echocardiography. MDCT findings were compared with echocardiographic findings using kappa statistics. The areas under the receiver operating characteristic curves (AUCs) and the odds ratios (ORs) of early perfusion defects (EPD), delayed enhancement (DE), and residual perfusion defects (RPD) for predicting follow-up myocardial dysfunction and functional recovery were calculated on a segmental basis. Results: The presence of transmural EPD (EPD{sub TM}) or RPD showed good agreement (k = 0.611 and 0.658, respectively) with follow-up myocardial dysfunction, while subendocardial EPD (EPD{sub sub}) or subendocardial DE (DE{sub sub}) showed fair agreement with follow-up myocardial dysfunction (k = 0.235 and 0.234, respectively). The AUC of RPD (0.796) was superior (p < 0.001 and 0.031, respectively) to those of EPD{sub TM} (0.761) and DE{sub TM} (0.771). The presence of EPD{sub TM}, DE{sub TM}, and RPD were significant, independent positive predictors of follow-up myocardial dysfunction (OR = 6.4, 1.9, and 9.8, respectively). EPD{sub TM} was a significant, independent negative predictor of myocardial functional recovery (OR = 0.13). Conclusion: Abnormal myocardial attenuation on two-phase MDCT after reperfusion therapy may provide promising information regarding myocardial viability in patients with acute MI.

  18. ELECTROCARDIOGRAMS AND VECTORELECTROCARDIOGRAMS—An Appraisal of Their Value in Subendocardial and in Transmural Myocardial Infarction

    Science.gov (United States)

    Talbot, John C.; Cosby, Richard S.; Levinson, David C.; Griffith, George C.; Mayo, Mary

    1956-01-01

    By vector methods quantitative differences can be shown to be present between subendocardial and transmural myocardial infarction. In acute transmural infarction the vector shift occurs later, the degree of shift is greater, the return to normal is later in time and an abnormal vector shift remains more frequently than in subendocardial infarction. In acute anteroseptal transmural infarction the degree of vector shift was closely correlated with the severity of the acute illness. PMID:13342996

  19. Explanation for the electrocardiogram in subendocardial ischemia of the anterior wall of the left ventricle.

    Science.gov (United States)

    Gorgels, Anton P M

    2009-01-01

    Recently, an important electrocardiogram picture indicating anterior wall ischemia was discussed, characterized by (1) loss of R wave and (2) not infrequently a notch in the negative limb of the QRS complexes in the precordial leads, combined with (3) ST depression and (4) a tall peaked T wave. An explanation of this electrocardiogram picture is offered based on the likely subendocardial localization of the ischemia and the resulting behavior of the subendocardial action potentials compared with the subepicardial action potentials.

  20. Viability Theory

    CERN Document Server

    Aubin, Jean-Pierre; Saint-Pierre, Patrick

    2011-01-01

    Viability theory designs and develops mathematical and algorithmic methods for investigating the adaptation to viability constraints of evolutions governed by complex systems under uncertainty that are found in many domains involving living beings, from biological evolution to economics, from environmental sciences to financial markets, from control theory and robotics to cognitive sciences. It involves interdisciplinary investigations spanning fields that have traditionally developed in isolation. The purpose of this book is to present an initiation to applications of viability theory, explai

  1. Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR.

    Science.gov (United States)

    Nagao, Michinobu; Hatakenaka, Masamitsu; Matsuo, Yoshio; Kamitani, Takeshi; Higuchi, Ko; Shikata, Fumiaki; Nagashima, Mitsugi; Mochizuki, Teruhito; Honda, Hiroshi

    2012-02-02

    The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86. Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest. © 2012 Nagao et al; licensee BioMed Central Ltd.

  2. Concentric hypertrophic remodelling and subendocardial dysfunction in mitochondrial DNA point mutation carriers†

    Science.gov (United States)

    Bates, Matthew G.D.; Hollingsworth, Kieren G.; Newman, Jane H.; Jakovljevic, Djordje G.; Blamire, Andrew M.; MacGowan, Guy A.; Keavney, Bernard D.; Chinnery, Patrick F.; Turnbull, Douglass M.; Taylor, Robert W.; Trenell, Michael I.; Gorman, Grainne S.

    2013-01-01

    Aims Hypertrophic remodelling and systolic dysfunction are common in patients with mitochondrial disease and independent predictors of morbidity and early mortality. Screening strategies for cardiac disease are unclear. We investigated whether myocardial abnormalities could be identified in mitochondrial DNA mutation carriers without clinical cardiac involvement. Methods and results Cardiac magnetic resonance imaging was performed in 22 adult patients with mitochondrial disease due to the m.3243A>G mutation, but no known cardiac involvement, and 22 age- and gender-matched control subjects: (i) Phosphorus-31- magnetic resonance spectroscopy, (ii) cine imaging (iii), cardiac tagging and (iv) late gadolinium enhancement (LGE) imaging. Disease burden was determined using the Newcastle Mitochondrial Disease Adult Scale (NMDAS) and urinary mutation load. Compared with control subjects, patients had an increased left ventricular mass index (LVMI), LV mass to end-diastolic volume (M/V) ratio, wall thicknesses (all P subendocardial dysfunction occur in patients carrying m.3243A>G mutation without clinical cardiac disease. Patients with higher mutation loads and disease burden may be at increased risk of cardiac involvement. PMID:23129433

  3. Improved detection of subendocardial hyperenhancement in myocardial infarction using dark blood-pool delayed enhancement MRI.

    Science.gov (United States)

    Farrelly, Cormac; Rehwald, Wolfgang; Salerno, Michael; Davarpanah, Amir; Keeling, Aoife N; Jacobson, Jason T; Carr, James C

    2011-02-01

    Delayed enhancement MRI using fast segmented k-space inversion recovery (IR) gradient-echo imaging is a well established "bright-blood" technique for identifying myocardial infarction and is used as the reference standard sequence in this study. The purpose of this study was to validate a recently developed dark blood-pool delayed enhancement technique in a porcine animal model, evaluate its performance in human patients, and quantify its performance compared with the reference standard in both. In an animal study, the reference standard and dark blood-pool delayed enhancement were assessed in three pigs with induced myocardial infarction. In a human study, 26 patients, 31-81 years old (19 men and seven women), with a known history of myocardial infarction were imaged using the reference standard and dark blood-pool delayed enhancement. Contrast-to-noise ratio (CNR), signal intensity ratio, signal-to-noise ratio (SNR), and qualitative scores of hyperenhancement were recorded. Measurements were compared using paired samples t test and Wilcoxon's signed rank test. In the animal study, the mean CNR of infarct to blood pool was 11 times higher for dark blood-pool delayed enhancement than for the reference standard. The mean SNR was 4.4 times higher for the reference standard. In the human study, the mean CNR and signal intensity ratio of hyperenhancing myocardium to the blood pool were 1.9 (p = 0.04) and 5.5 (p subendocardial foci of hyperenhancement, thus potentially identifying more infarcts and changing patient management.

  4. The Significance of Subendocardial Hemorrhages Detected in Forensic Autopsies

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    Nursel Türkmen İnanır

    2015-06-01

    Full Text Available Introduction:In our study, our aim was to reveal the relationship between subendocardial hemorrhage (SEH  which can be seen macroscopically immediately beneath the endocardium, and emerge secondary to many conditions from direct cardiac,  head, and abdominal traumas to hyperemia, and its location with cause of death, its diagnostic value (if any, and whether it can be evaluated as a vital finding.Material and Method :285 autopsy cases diagnosed as SEH which were brought to the Group Presidency of Morgue Specialization Department of the State Institute of Forensic Medicine of Bursa  were included in the studyResults: Study population consisted of 229 (80.4 % male, and 56 (19.6 % female patients. Thity-one cases of death were related to natural causes, while the most frequently detected pathological causes of death were isolated abdominal traumas (32.9 %, followed by isolated head traumas (31.9 %.  While traffic accidents ranked first (35.1% among the events leading to death. Among evaluated cases, SEH was mostly located on septum.Discussion: To fully understand the yet inadequately elucidated pathogenic mechanisms  of SEH , it should be accurately defined by histopathological analysis. Even though various causes of death seen  in association with these lesions suggest more than one underlying pathogenic mechanism, because of their nonspecific characteristics, their possible roles as indicators of vitality (if any should be reinforced  by further studies.

  5. Subendocardial Systolic Dysfunction in Asymptomatic Normotensive Diabetic Patients.

    Science.gov (United States)

    Enomoto, Mami; Ishizu, Tomoko; Seo, Yoshihiro; Yamamoto, Masayoshi; Suzuki, Hiroaki; Shimano, Hitoshi; Kawakami, Yasushi; Aonuma, Kazutaka

    2015-01-01

    It remains uncertain whether diabetes itself causes specific echocardiographic features of myocardial morphology and function in the absence of hypertension or ischemic heart disease. The purpose of the present study was to determine the characteristics of pure diabetic cardiomyopathy-related echocardiographic morphology and function using layer-by-layer evaluation with myocardial strain echocardiography. We enrolled 104 patients with poorly controlled type 2 diabetes mellitus (mean HbA1c level, 10%) with (n=74) or without (n=40) hypertension and 24 age- and sex-matched healthy volunteers. Patients with coronary artery stenosis or structural heart disease were excluded. Myocardial layer-specific strain was analyzed by speckle tracking echocardiography. Compared with the healthy control group, the normotensive diabetes group showed no significant difference in ejection fraction, left ventricular mass index, diastolic properties, left atrial volume index, or B-type natriuretic protein (BNP) level, but global longitudinal strain and subendocardial radial strain were significantly deteriorated. The deterioration of longitudinal strain correlated with body mass index (R=0.49, Psubendocardial wall thickening are the characteristic functional abnormalities of diabetic cardiomyopathy in patients without hypertrophy, diastolic dysfunction, or elevated BNP. Obesity and blood pressure may also play important roles in this strain abnormality in asymptomatic patients with type 2 diabetes.

  6. Impairment of subendocardial perfusion reserve and oxidative metabolism in nonischemic dilated cardiomyopathy.

    Science.gov (United States)

    Bell, Susan P; Adkisson, Douglas W; Ooi, Henry; Sawyer, Douglas B; Lawson, Mark A; Kronenberg, Marvin W

    2013-12-01

    Cardiac magnetic resonance (CMR) and [(11)C]acetate positron emission tomography (PET) were used to assess the hypothesis that patients with nonischemic dilated cardiomyopathy (NIDCM) have decreased subendocardial perfusion reserve and impaired oxidative metabolism, consistent with the concept of "energy starvation" in heart failure (HF). CMR myocardial perfusion was evaluated in 13 NIDCM patients and 15 control subjects with coronary risk factors and normal myocardial perfusion. The NIDCM patients underwent [(11)C]acetate PET. The myocardial perfusion index (MPI) was calculated as the normalized rate of myocardial signal augmentation following gadolinium contrast injection. Hyperemic transmural, subendocardial, and subepicardial MPI were reduced in NIDCM compared with control subjects [0.13 vs 0.18 (P subendocardial perfusion reserve was 1.59 ± 0.21 vs 1.86 ± 0.32 for the subepicardium (P = .002), demonstrating reduced perfusion reserve. The myocardial oxidative metabolic rate (kmono) per unit demand (rate-pressure product) was reduced in proportion to perfusion reserve (P = .02) CONCLUSIONS: Impaired subendocardial perfusion reserve in NIDCM confirmed results previously attained only in animal models. Impaired perfusion and impaired oxidative metabolism are consistent with subendocardial energy starvation in HF. Published by Elsevier Inc.

  7. Left ventricular rotational mechanics in patients with coronary artery disease: differences in subendocardial and subepicardial layers.

    Science.gov (United States)

    Bertini, Matteo; Delgado, Victoria; Nucifora, Gaetano; Ajmone Marsan, Nina; Ng, Arnold C T; Shanks, Miriam; Antoni, M Louisa; van de Veire, Nico R L; van Bommel, Rutger J; Rapezzi, Claudio; Schalij, Martin J; Bax, Jeroen J

    2010-11-01

    Subendocardial and subepicardial layers have opposite orientation of the myofibres and they are differently affected by coronary artery disease. This study investigated the differences in subendocardial and subepicardial left ventricular (LV) twist in patients with coronary artery disease. 214 patients were included in the study: 60 with first ST elevation myocardial infarction (STEMI), 111 with chronic ischaemic heart failure (HF) and 43 normal subjects. Real-time three-dimensional echocardiography provided LV volumes and function. Two-dimensional speckle tracking echocardiography differentiating the subendocardial and subepicardial layers was used for the assessment of LV twist. Patients with STEMI were divided into two groups (small and large STEMI). Compared with normal subjects, peak subendocardial LV twist was significantly impaired in patients with STEMI (11.2 ± 6.0° vs 15.3 ± 2.7°, psubendocardial LV twist was even more impaired (4.6 ± 3.4°, psubendocardial LV twist was not statistically different between large and small STEMI, whereas peak subepicardial LV twist was significantly lower in large STEMI than in small STEMI (7.1 ± 4.8° vs 9.6 ± 3.6°, p=0.025). Subendocardial LV twist is reduced in patients with STEMI and chronic ischaemic HF whereas subepicardial LV twist is reduced only in chronic ischaemic HF. When STEMI are divided into large and small infarctions, it becomes evident that subepicardial LV twist is only reduced in large infarctions.

  8. Correlation between reverse redistribution and subendocardial myocardial infarction observed in myocardial contrast echocardiography

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    Kim, Sung Eun; Choe, Won Sick; Kwan, Jun [Inha Univ. Hospital, Inchon (Korea, Republic of)

    2000-06-01

    The aim of this study is to better understand the pattern and nature of reverse redistribution (RR) in myocardial perfusion imaging. In consecutive 20 acute myocardial infarction (MI) patients, frequency of RR was correlated with that of subendocardial MI that was detected by myocardial contrast echocardiography (MCE). RR was judged to be present when there was more than one grade of worsening in perfusion at 24 hr delayed images compared with the initial rest images. MCE evaluated the significant lack of opacification in the subendocardial myocardium relative to the subepicardial myocardium to suggest the subendocardial MI. Kendall's nonparametric correlation coefficiency was calculated. Concordant cases were 15 of 20 (75%) and correlation was statistically significant (p=3D0.0285). Our results suggested that RR was correlated with MCE-detected nontransmural MI.

  9. Application of Speckle-Tracking Echocardiography in an Experimental Model of Isolated Subendocardial Damage.

    Science.gov (United States)

    Beyhoff, Niklas; Brix, Sarah; Betz, Iris R; Klopfleisch, Robert; Foryst-Ludwig, Anna; Krannich, Alexander; Stawowy, Philipp; Knebel, Fabian; Grune, Jana; Kintscher, Ulrich

    2017-10-21

    The subendocardium is highly vulnerable to damage and is thus affected even in subclinical disease stages. Therefore, methods reflecting subendocardial status are of great clinical relevance for the early detection of cardiac damage and the prevention of functional impairment. The aim of this study was to investigate the potential ability of myocardial strain parameters to evaluate changes within the subendocardium. Male 129/Sv mice were injected with isoproterenol (ISO; n = 32) to induce isolated subendocardial fibrotic lesions or saline as appropriate control (n = 15). Transthoracic echocardiography was performed using a 30-MHz linear-frequency transducer coupled to a high-resolution imaging system, and acquired images were analyzed for conventional and strain parameters. The degree of collagen content within the different cardiac layers was quantified by histologic analysis and serum levels of tissue inhibitor of metalloproteinase-1, a biomarker for fibrosis, were assessed. ISO treatment induced a marked increase in subendocardial collagen content in response to cell loss (control vs ISO, 0.6 ± 0.3% vs 5.8 ± 0.9%; P subendocardial collagen content (r = 0.46, P = .01) and tissue inhibitor of metalloproteinase-1 serum level (r = 0.52, P subendocardial fibrosis (sensitivity, 84%; specificity, 80%; cutoff value, -14.4%). Assessment of LS may provide a noninvasive method for the detection of subendocardial damage and may consequently improve early diagnosis of cardiac diseases. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  10. Calcium channel blockade prevents pressure-dependent inward remodeling in isolated subendocardial resistance vessels

    NARCIS (Netherlands)

    O. Sorop (Oana); E.N.T.P. Bakker (Erik ); A. Pistea (Adrian); J.A. Spaan (Jos Ae); E. VanBavel (Ed)

    2006-01-01

    textabstractThe capacity for myocardial perfusion depends on the structure of the coronary microvascular bed. Coronary microvessels may adapt their structure to various stimuli. We tested whether the local pressure profile affects tone and remodeling of porcine coronary microvessels. Subendocardial

  11. Surgical ventricular reconstruction and subendocardial resection for the treatment of refractory ventricular tachycardia.

    Science.gov (United States)

    Ismail, N A; Bence, J; Spyt, T J

    2014-11-01

    We describe a case of 64-year-old female patient with ventricular tachycardia intractable to medical treatment and acute heart failure following myocardial infarction. Emergency surgical ventricular reconstruction and subendocardial resection was undertaken. We discuss the option of surgical intervention in this difficult and unusual clinical scenario.

  12. Delayed onset of subendocardial diastolic thinning at rest identifies hypoperfused myocardium.

    Science.gov (United States)

    Wang, Jianwen; Abraham, Theodore P; Korinek, Josef; Urheim, Stig; McMahon, Eileen M; Belohlavek, Marek

    2005-06-07

    Onset of myocardial relaxation is highly energy dependent. Perfusion and therefore energy substrate delivery are predominantly reduced in the subendocardial myocardium in the early stages of progressive ischemia. We hypothesized that delayed onset of subendocardial diastolic thinning will functionally identify regionally hypoperfused resting myocardium. Progressive left anterior descending coronary artery stenosis was induced by an ameroid occluder and maintained for 1 or 2 weeks (end point) in 12 dogs. M-mode tissue Doppler images of the anterior apical and middle segments (testing region) and middle inferior segment (control region) were acquired selectively in the subendocardium and subepicardium. The time to the onset of thinning was measured with the use of tissue Doppler velocity (TOTv) and a thickness function (TOTt). At the end point in the testing region, myocardial flow was significantly lower in the subendocardial layer (Psubendocardial necrosis in 2 dogs. Both TOTv and TOTt were significantly (Psubendocardial and subepicardial TOTv values versus that in the control region identified the ischemic region, even when only dogs with hypoperfused but transmurally viable myocardium were considered (Psubendocardial hypoperfusion. In resting myocardium subtended to progressive coronary stenosis, a delayed onset of subendocardial thinning suggests an early stage of hypoperfusion, before the development of local wall motion abnormalities.

  13. Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

    Directory of Open Access Journals (Sweden)

    Nagao Michinobu

    2012-02-01

    Full Text Available Abstract Background The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV using tagged cardiovascular magnetic resonance (CMR and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. Methods 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix. The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. Results The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6% than non-stenotic segment (-18.8 ± 10.2%, p Conclusions Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.

  14. Evaluation of subendocardial and subepicardial left ventricular functions using tissue Doppler imaging after complete revascularization.

    Science.gov (United States)

    Sürücü, Hüseyin; Tatli, Ersan; Okudan, Selnur; Aktoz, Meryem

    2009-02-01

    We aim to evaluate subepicardial and subendocardial left ventricular (LV) functions in patient single coronary artery lesion at early stage after percutaneous coronary intervention (PCI). Additionally, a comparison of LV functions between patients and control cases was aimed. Patients with culprit left anterior descending (LAD) lesion (n = 25) and subjects with normal coronary angiography (n = 25) were evaluated. Patients underwent PCI and at least one coronary stent was placed. After PCI, the pulsed-wave tissue Doppler imaging (pw-TDI) parameters taken from subepicardial and subepicardial layers were compared among the patients. Left atrium (P = 0.050), LV end-diastolic (P = 0.049), and end-systolic (P = 0.006) diameters were larger compared to the control group. LV inflow velocities were not different between the patient and the control group. But, the myocardial performance index was different (P = 0.049). The systolic and diastolic pw-TDI parameters were apparently different between the patient and the control group. While the systolic pw-TDI parameters did not change, the diastolic pw-TDI parameters taken from both subepicardial (circumferential contraction) and subendocardial layers (longitudinal contraction) improved after PCI. After PCI, it was shown that while Ea velocity (P = 0.012) taken from the subendocardial layer increased, IVRa velocity (P subendocardial and subepicardial layers. These dysfunctions can be easily presented with pw-TDI. Although systolic dysfunction persists, diastolic dysfunction improves at early stage after PCI.

  15. Cardiac magnetic resonance imaging showing complete resolution of subendocardial involvement in Churg-Strauss syndrome.

    Science.gov (United States)

    Post, Martijn C; Boomsma, Martijn F; van Heesewijk, Johannes P M; Grutters, Jan C; Van der Heyden, Jan

    2011-08-01

    Churg-Strauss syndrome or allergic angiitis and granulomatosis is a rare systemic vasculitis. Cardiac involvement is the leading cause of mortality and includes eosinophilic endomyocarditis. We present a case of complete resolution of subendocardial involvement after high-dose corticosteroids, diagnosed by contrast-enhanced cardiovascular magnetic resonance imaging.

  16. Role of subendocardial Purkinje network in triggering torsade de pointes arrhythmia in experimental long QT syndrome.

    Science.gov (United States)

    Ben Caref, E; Boutjdir, Mohamed; Himel, Herman D; El-Sherif, Nabil

    2008-10-01

    The present study addresses the controversy regarding the 'primary' role of the subendocardial Purkinje network in triggering torsade de pointes (TdP) ventricular tachyarrhythmia (VAs) in the long QT syndrome (LQTS). We investigated the well-established canine anthopleurin-A (AP-A) surrogate model of LQT3 to study the role of the subendocardial Purkinje network in triggering VAs. Three-dimensional activation and repolarization patterns were analysed from unipolar extracellular electrograms utilizing 64 plunge needle electrodes. In 6 dogs, the animals were placed on cardiopulmonary bypass and chemical ablation of the endocardial Purkinje network was obtained using Lugol's solution. Spontaneous VAs consistently developed in response to AP-A infusion and were triggered by a subendocardial focal activity acting on a substrate of spatial three-dimensional dispersion of repolarization. Endocardial ablation was considered successful by the development of complete atrioventricular block in the absence of ventricular escape rhythm. Following endocardial ablation spontaneous VAs were no longer observed. However, an appropriately coupled premature stimulus consistently induced re-entrant VAs. The present study strongly suggests that in the LQTS, focal activity generated in subendocardial Purkinje tissue is the primary, if not the only, trigger for TdP VAs by acting on a substrate of three-dimensional dispersion of myocardial repolarization to induce re-entrant excitation.

  17. Impairment of Subendocardial Perfusion Reserve and Oxidative Metabolism in Non-Ischemic Dilated Cardiomyopathy

    Science.gov (United States)

    Bell, Susan P.; Adkisson, Douglas W.; Ooi, Henry; Sawyer, Douglas B.; Lawson, Mark A.; Kronenberg, Marvin W.

    2014-01-01

    Background Cardiac magnetic resonance (CMR) and [11C] acetate positron emission tomography (PET) were used to assess the hypothesis that patients with nonischemic dilated cardiomyopathy (NIDCM) have decreased subendocardial perfusion reserve and impaired oxidative metabolism, consistent with the concept of “energy starvation” in heart failure (HF). Methods and results CMR myocardial perfusion was evaluated in 13 NIDCM patients and 15 control subjects with coronary risk factors and normal myocardial perfusion. The NIDCM patients underwent [11C] acetate PET. The myocardial perfusion index (MPI) was calculated as the normalized rate of myocardial signal augmentation following gadolinium contrast injection. Hyperemic transmural, subendocardial and subepicardial MPI were reduced in NIDCM compared to control subjects [0.13 vs. 0.18 (Psubendocardial perfusion reserve was 1.59 ± 0.21 vs. 1.86 ± 0.32 for the subepicardium (P= 0.002) demonstrating reduced perfusion reserve. The myocardial oxidative metabolic rate (kmono) per unit demand (rate-pressure product) was reduced proportional to perfusion reserve (P=0.02) Conclusions Impaired subendocardial perfusion reserve in NIDCM confirmed results previously attained only in animal models. Impaired perfusion and impaired oxidative metabolism are consistent with subendocardial energy starvation in HF. PMID:24331202

  18. Subendocardial versus transmural ischaemia in myocardial perfusion SPECT--a Monte Carlo study.

    Science.gov (United States)

    Bartosik, Jolanta; El-Ali, Henrik Hussein; Nilsson, Ulf; Dahlström, Jan; Edenbrandt, Lars; Ljungberg, Michael

    2006-11-01

    Myocardial perfusion imaging with single-photon emission computed tomography (SPECT) is useful for the evaluation of patients with known or suspected coronary artery disease. Parameters of interest are the reduction in the blood perfusion (severity) and the lesion volume (extent). The aim of this study was to evaluate these parameters, as calculated by automatic quantification software, for different cases of subendocardial and transmural myocardial lesions. A computer phantom was used to simulate 32 male patients with different defect locations and activity uptakes, which were based on clinical patient studies. The Monte Carlo program SIMIND was used to simulate realistic SPECT projections which were reconstructed to give short-axis images, analysed by the AutoQUANT program using the same procedure as for a real patient. The results showed a disparity between the quantification of transmural and subendocardial lesions with the same lesion activity uptake reduction and this could be confirmed by visual interpretation. Neither the parameters given by the quantification program nor visual interpretation could distinguish between the transmural lesions and the subendocardial lesions with activity uptake reduction twice as high as in the corresponding transmural lesions. Transmural lesions and the corresponding subendocardial lesions with the same activity uptake reduction could be separated by the quantification software for SPECT imaging and visual analysis. The subendocardial lesions with activity uptake reduction twice as high as in the corresponding transmural lesions could not be differentiated neither by the quantification software nor by visual interpretation. Thus these lesions will get the same scoring when analysed by the AutoQUANT program.

  19. Lateral border zone: quantitation of lateral extension of subendocardial infarction in the dog.

    Science.gov (United States)

    Forman, R; Cho, S; Factor, S M; Kirk, E S

    1985-05-01

    This study was undertaken to quantitate the lateral extension that occurs concomitantly with the transmural extension of a subendocardial infarction. A subendocardial infarct was produced in 12 dogs by a 40 minute temporary coronary artery occlusion. Infarct extension was induced 7 days later by permanent occlusion of the same vessel. Regional myocardial blood flows confirmed that ischemia had been produced with both coronary artery occlusions. The vascular boundaries between the normally perfused and ischemic beds were defined by perfusion with different-colored Microfil solutions. The extent of subendocardial infarction and subsequent transmural and lateral extensions were assessed by point counting of histologic specimens. The initial temporary occlusion produced a 30.0 +/- 4.2% transmural infarct and the subsequent permanent occlusion a 29.2 +/- 3.5% transmural extension in a risk region of 39 +/- 4 g. Lateral extension was not measured in four dogs because the initial subendocardial infarct was patchy with markedly irregular lateral borders. In eight dogs the size of the measured lateral infarct extension from each lateral margin from two histologic sections was 0.63 +/- 0.013 cm2. The area of both lateral extensions was 1.7 +/- 0.1% of the cross-sectional area of its risk region as determined by planimetry. Using a model of the risk region, the mass of the lateral extension was estimated to be 1.4 +/- 0.3 g or 3.5 +/- 0.6% of the region at risk. Thus, at the lateral margin of a subendocardial infarct there is a border zone that is small relative to the size of the region at risk and infarcted myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Uncommon case of subendocardial infarction studied by technetium-99m stannous pyrophosphate myocardial scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Kazuya; Kondo, Shigeyo; Yoshida, Susumu; Ota, Koji; Sera, Kazuaki

    1985-03-01

    The patient was a 61-year-old female. Her occupation was an office clerk. The chief complaint was anterior chest pain. She was diagnosed subendocardial infarction by her clinical symptoms and electrocardiograms. Peak CPK was in the low level. But sup(99m)Tc-PYP scintigraphy was performed about 30 hours after her admission and showed abnormal dense accumulation in the anterior wall of the left ventricle. On sup(99m)Tc-PYP scintigraphy, subendocardial infarctions have been reported to show lower accumulation than transmural ones in many cases. But in this case coronary arteriography showed almost normal pattern and peak CPK was low in spite of abnormal accumulation on sup(99m)Tc-PYP scintigrams. This was considered to be a very rare case. The deeper understanding of peripheral ischemic changes is essential for explaining this state. (author).

  1. Organization and collateralization of a subendocardial plexus in end-stage human heart failure.

    Science.gov (United States)

    van den Wijngaard, Jeroen P H M; van Horssen, Pepijn; ter Wee, Rene; Coronel, Ruben; de Bakker, Jacques Mt; de Jonge, Nicolaas; Siebes, Maria; Spaan, Jos A E

    2010-01-01

    In the failing myocardium a subendocardial plexus can develop. Detection of the presence or function, however, of such a plexus does not form part of the present diagnostic spectrum for heart failure. This may now change as new methods for high-resolution imaging of myocardial perfusion distribution are being developed. A severely hypertrophic heart was harvested during transplantation and analyzed for morphology of the intramural coronary arterial vasculature. The heart only had one coronary ostium, and the main branches of the coronary artery were cannulated. A fluorescent casting material was infused that was allowed to harden under physiological pressure. The entire heart was frozen and placed in a novel imaging cryomicrotome and sequentially cut in 25-microm slices. High-resolution images of each cutting plane were acquired, allowing a detailed three-dimensional reconstruction of the arterial vasculature. The epicardial layer of the free wall demonstrated a normal vasculature with penetrating branching arteries. The endocardial layer and the septum revealed a highly interconnected vascular plexus with large vessels oriented parallel to the apicobasal axis. An extensive endocardial network with collaterals was detected, forming connections between the main epicardial branches. We conclude that an outward remodeling of transmural vessels did not prevent the generation and growth of subendocardial conduit arteries. The orientation and vascular volume in the plexus provides an opportunity for detection by novel techniques of MRI contrast imaging currently developed. Knowledge of the effect on perfusion studies is required to prevent a misinterpretation of subendocardial perfusion images in heart failure.

  2. Valve replacement for aortic stenosis normalizes subendocardial function in patients with normal ejection fraction.

    Science.gov (United States)

    Lindqvist, Per; Bajraktari, Gani; Molle, Roberta; Palmerini, Elizabetta; Holmgren, Anders; Mondillo, Sergio; Henein, Michael Y

    2010-08-01

    Long-standing aortic stenosis (AS) causes various degrees of left ventricular (LV) dysfunction, which may improve after valve replacement. The aim of this study was to assess the nature of LV subendocardial abnormalities in AS and their response to valve replacement (AVR). We studied 41 consecutive symptomatic patients (age 64 +/- 13 years) with severe AS, normal LV ejection fraction (EF), but no obstructive coronary artery disease before, a week after AVR, and 6 months after AVR. LV subendocardial function was studied from recordings of long-axis M-mode (amplitude), tissue-Doppler (myocardial velocities) and speckle tracking (myocardial strain) echocardiographic techniques. Results were compared with those from 20 age- and gender-matched controls. In patients, LV dimensions and markers of asynchrony, total isovolumic time (t-IVT), and Tei index were not different from controls before AVR and remained unchanged afterwards. LV lateral long-axis amplitude, as well as lateral and septal systolic velocities and strain, were reduced (P subendocardial function is globally abnormal showing reduced amplitude of motion, velocities, and strain. The different response of its components suggests an evidence for differential reverse remodelling, irrespective of myocardial mass regression.

  3. Subendocardial hemorrhages in a case of extrapercardial cardiac tamponade: A possible mechanism of appearance

    Directory of Open Access Journals (Sweden)

    Nikolić Slobodan

    2016-01-01

    Full Text Available Introduction. Subendocardial hemorrhages are grossly visible bleedings in the inner surface of the left ventricle, the interventricular septum, and the opposing papillary muscles and adjacent columnae carneae of the free wall of the ventricle. These are commonly seen in sudden profound hypotension either from severe blood loss from “shock” in the widest sense and, even more often, in combination with brain injuries. Case Outline. We present a case of a 38-year-old man, injured as a car driver in a frontal collision, who died c. 45 minutes after the accident. The autopsy revealed severe chest trauma, including multiple right-sided direct rib fractures with the torn parietal pleura and right-sided pneumothorax, several right lung ruptures, and a rupture of one of the lobar bronchi with pneumomediastinum, and prominent subcutaneous emphysema of the trunk, shoulders, neck and face. The patchy subendocardial hemorrhage of the left ventricle was observed. The cause of death is attributed to severe blunt force chest trauma. Conclusion. We postulate pneumomediastinum leading to extrapericardial tamponade as the underlying mechanism of this subendocardial hemorrhage. [Projekat Ministarstva nauke Republike Srbije, br. 45005

  4. Depressed recovery of subendocardial perfusion in persistent heart failure after complete revascularisation in diabetic patients with hibernating myocardium.

    Science.gov (United States)

    Mizuno, R; Fujimoto, S; Saito, Y; Nakamura, S

    2009-05-01

    To investigate the relation between myocardial perfusion and heart failure (HF) status after revascularisation in patients with HF due to hibernating myocardium (HM) in diabetic and non-diabetic subjects. 31 diabetic and 33 non-diabetic subjects with HF due to HM, who were already scheduled for complete revascularisation, were studied. Before and after revascularisation, left ventricular function and regional perfusion in subendocardial and subepicardial portions of the left ventricular wall were evaluated. Before revascularisation, left ventricular function and regional perfusion were similar in diabetic and non-diabetic subjects. At 6 months after revascularisation, subepicardial perfusion was markedly improved both in diabetic and non-diabetic subjects. However, subendocardial perfusion was markedly improved only in non-diabetic subjects and was little changed in diabetic patients. Thus, subendocardial perfusion was much lower in diabetic than non-diabetic subjects. Left ventricular function was improved more in non-diabetic than in diabetic subjects. Persistent HF was found much more often in diabetic than non-diabetic subjects. At multivariate analysis, subendocardial perfusion at 6 months independently contributed to persistent HF. This study describes the intramural heterogeneity of recovery of myocardial perfusion with depressed improvement in the subendocardial portion and its relation with persistent HF after complete revascularisation in diabetic patients with HF due to HM.

  5. Multilayer radial systolic strain can identify subendocardial ischemia: an experimental tissue Doppler imaging study of the porcine left ventricular wall.

    Science.gov (United States)

    Matre, Knut; Moen, Christian Arvei; Fanneløp, Tord; Dahle, Geir Olav; Grong, Ketil

    2007-12-01

    This study investigates whether subendocardial ischemia can be detected by measuring multilayer radial systolic strain from epicardial tissue Doppler imaging. In 10 anesthetized open-chest pigs an extracorporeal shunt from the proximal brachiocephalic to the left anterior descending coronary artery was constricted in steps. Color microsphere injections and short axis Tissue Velocity Imaging (TVI) recordings were performed with open shunt, with a non-significant stenosis, and with 2 steps of shunt flow reduction. With open shunt and no transmural flow gradient, there was a gradient of peak ejection strain with high values subendocardially for both 4 and 2 layer measurements. For 2 layer measurement strain was 56.0+/-10.5% subendocardially and 22.0+/-5.2% subepicardially. A non-significant stenosis, not altering transmural flow distribution, reduced strain to 40.3+/-5.4% in the endocardial half-layer. With reduced shunt flow resulting in subendocardial ischemia, peak ejection strain decreased further, primarily in inner wall layers, and postsystolic strain became evident. At severe stenosis (52.4+/-1.8% shunt flow reduction) strain was reduced to 3.8+/-3.6% in the subendocardium and 0.0+/-2.6% in the subepicardium. Evaluation of myocardial function with multilayer radial systolic strain has a potential for detecting subendocardial ischemia.

  6. Is subendocardial ischaemia present in patients with chest pain and normal coronary angiograms? A cardiovascular MR study.

    Science.gov (United States)

    Vermeltfoort, Ilse A C; Bondarenko, Olga; Raijmakers, Pieter G H M; Odekerken, Diego A M; Kuijper, Aaf F M; Zwijnenburg, Anton; van der Vis-Melsen, Mary J E; Twisk, Jos W R; Beek, Aernout M; Teule, Gerrit J J; van Rossum, Albert C

    2007-07-01

    On the basis of an MRI study it has been suggested that subendocardial hypoperfusion is present in patients with cardiac syndrome X. However, further work is required to test whether these findings can be generalized. MRI was used to visually and semi-quantitatively assess subendocardial and subepicardial perfusion, at rest and during an infusion of adenosine, in 20 patients with angina pectoris and normal coronary angiograms. A myocardial perfusion index (MPI) was calculated using the normalized upslope of myocardial signal enhancement. An index for myocardial perfusion reserve (MPRI) was calculated by dividing the MPI values at maximal vasodilatation by the values at rest. The MPI in our study population increased significantly during adenosine infusion in both the subendocardium (from 0.091 +/- 0.020 to 0.143 +/- 0.030; P subendocardial hypoperfusion in these patients.

  7. Detection of subendocardial ischemia in the left anterior descending coronary artery territory with real-time myocardial contrast echocardiography during dobutamine stress echocardiography.

    Science.gov (United States)

    Xie, Feng; Dodla, Saritha; O'Leary, Edward; Porter, Thomas R

    2008-05-01

    The purpose of this study was to test whether the transmural delineation of myocardial perfusion during dobutamine stress imaging with real-time myocardial contrast echocardiography (RTMCE) might permit visualization of dobutamine-induced subendocardial ischemia. Significant coronary artery disease can be present despite normal transmural wall thickening (WT) responses during dobutamine stress echocardiography (DSE). One potential reason is dobutamine-induced recruitment of epicardial WT in the presence of subendocardial ischemia. Myocardial perfusion and WT were examined with RTMCE during DSE with a continuous infusion of ultrasound contrast in 94 patients with normal resting WT. Fifty-five of the patients had a >50% diameter stenosis in the left anterior descending coronary artery (LAD). The WT was visually assessed by a blinded reviewer at 2 time periods: initially after a high mechanical index impulse before myocardial contrast replenishment (MCR), and again during MCR. Subendocardial %WT was measured during MCR, if a subendocardial perfusion defect was visually evident, whereas transmural WT was quantified on the pre-MCR images. Fifty patients (91%) with LAD stenoses exhibited a myocardial contrast defect at peak stress, with 45 defects being subendocardial. Transmural WT pre-MCR appeared normal in 35 of the 45 patients with subendocardial perfusion defects (78%). However, a subendocardial WT abnormality was apparent during MCR in 18 of these 35 patients, even though transmural WT was not different from the 17 patients with normal subendocardial WT (33 +/- 15% vs. 36 +/- 14%). Quantitative measurements of WT within the subendocardium were significantly less in the patients with visually evident subendocardial WT abnormalities, when compared with those who seemed to have normal WT during MCR (17 +/- 8% vs. 25 +/- 10%, p subendocardial ischemia even when transmural WT appears normal. Real-time myocardial contrast echocardiography should be the preferred

  8. Negative pressure pulmonary edema following septoplasty surgery triggering acute subendocardial myocardial infarction.

    Science.gov (United States)

    Kaya, Zeynettin; Tuncez, Abdullah; Gök, Umut; Gül, Enes Elvin; Altunbaş, Gökhan

    2014-04-01

    Negative pressure pulmonary edema (NPPE) is defined as fluid transudation into the pulmonary interstitium which occurs as a result of elevated negative intrathoracic pressure caused by the upper respiratory tract obstruction and strong inspiratory effort. NPPE is usually seen during emergence from general anesthesia in the early post-operative period especially after upper respiratory tract surgery. We present a case of a 37-year-old male patient who underwent septoplasty operation and developed NPPE which could not diagnosed and progressed to acute subendocardial myocardial infarction.

  9. Assessing the pattern of ST-segment depression during subendocardial ischemia using a computer simulation of the ventricular electrogram.

    Science.gov (United States)

    Bertella, Mauro; Nanna, Michele; Vanoli, Emilio; Scalise, Filippo

    2009-01-01

    The primary aim of the study was to write a simple educational personal computer (PC)-based program able to simulate normal and pathological electrogram (EG) to analyze the ST-segment and T-wave patterns during subendocardial ischemia. The EG waveforms are know to depend on the properties of transmembrane action potentials (APs) of atrial and ventricular myocytes, the spread of excitation, and the characteristics of the volume conductor. Transmembrane AP is an electromotive generator that plays a central role, and it is the principal responsible for the potential differences that are recorded as an EG. The EG can be considered as the algebric sum of 2 transmembrane APs, that is, the AP of the underlying endocardial region minus the AP of the underlying epicardial region. Using an educational PC software (Microsoft Excel), a normal EG was simulated reproducing planimetrically, point-by-point, normal transmembrane APs recorded from the epicardial and endocardial regions in normal animals. The shape and the voltage of the APs were then modified to closely mimic human APs. To simulate typical subendocardial ischemia, we changed the subendocardial AP according to experimental and clinical observations. The reconstruction of EG by the algebric subtraction (endocardial minus epicardial) APs was possible. The EG, mirroring typical subendocardial ischemia, was simulated without changing the epicardial AP. The EG simulating typical subendocardial ischemia showed a horizontal pattern of ST segment depression. In our model modification of the subendocardial AP combined with "unnatural" changes of the phase 3 of the subendocardial AP produced a downsloping pattern of ST-segment depression. The derivated EG waveform obtained with our PC program properly describe the algebric sum of endocardial and epicardial APs. In our opinion, this method represents a useful tool for the study of the AP changes. The simulated ST-depression morphology during subendocardial ischemia appears to

  10. Myocardial uptake of indium-111-labeled antimyosin in acute subendocardial infarction: Clinical, histochemical, and autoradiographic correlation of myocardial necrosis

    Energy Technology Data Exchange (ETDEWEB)

    Hendel, R.C.; McSherry, B.A.; Leppo, J.A. (Univ. of Massachusetts Medical Center, Worcester (USA))

    1990-11-01

    Indium-111-labeled antimyosin has been utilized in the diagnosis and localization of acute transmural myocardial infarction. The present report describes a patient who presented with a massive subendocardial infarction. Two days after the injection of antimyosin, the patient's clinical status markedly deteriorated and he expired. Postmortem examination demonstrated severe three-vessel coronary artery disease with extensive myocyte death in the endocardium. Autoradiography and histochemical staining of the prosected heart demonstrated high correlation for myocardial necrosis and corresponded to clinical evidence for diffuse subendocardial infarction.

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

    Science.gov (United States)

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

    2013-06-01

    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. © 2013 The Authors. International Journal of Experimental Pathology © 2013 International Journal of Experimental Pathology.

  12. Subendocardial segment length shortening at lateral margins of ischemic myocardium in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, K.P.; Gerren, R.A.; Choy, M.; Stirling, M.C.; Dysko, R.C. (Univ. of Michigan, Ann Arbor (USA))

    1987-10-01

    The lateral borders of an infarcted area are sharply delineated in terms of perfusion, but functional impairment extends a limited distance into adjacent nonischemic myocardium. To determine the distribution of functional impairment the authors arrayed three ultrasonic dimension gauges to measure two subendocardial segment lengths in series. The center crystal, placed at the perfusion boundary (PB) between left anterior descending and circumflex arteries, radiated ultrasound to receiver crystals 7-17 mm to either side of the PB. The locations of the functional measurements relative to the PB were determined with myocardial blood flow (tracer-labeled microsphere) maps constructed from multiple small tissue samples obtained circumferentially. On the ischemic side of the PB, dL decreased from 2.24 {plus minus} 0.54 to 0.42 {plus minus} 0.39 mm. By adding the data from the two segments in series, a combined measurement of dL across heterogeneously perfused myocardium was derived that decreased by 38% from control. The level of shortening represented an integral of normal and abnormal motion that was proportional to the mean reduction in blood flow ({minus}44%) in all of the muscle spanned by the crystals. They conclude that subendocardial segment lengths average shortening in the muscle they subtend when arrayed across the perfusion boundary.

  13. Clinical outcomes meta-analysis: measuring subendocardial perfusion and efficacy of transmyocardial laser revascularization with nuclear imaging.

    Science.gov (United States)

    Iwanski, Jessika; Knapp, Shannon M; Avery, Ryan; Oliva, Isabel; Wong, Raymond K; Runyan, Raymond B; Khalpey, Zain

    2017-05-19

    Randomized and nonrandomized clinical trials have tried to assess whether or not TMR patients experience an increase in myocardial perfusion. However there have been inconsistencies reported in the literature due to the use of different nuclear imaging modalities to test this metric. The primary purpose of this meta-analysis was to determine whether SPECT, MUGA and PET scans demonstrate changes in myocardial perfusion between lased and non-lased subjects and whether laser type affects myocardial perfusion. The secondary purpose was to examine the overall effect of laser therapy on clinical outcomes including survival, hospital re-admission and angina reduction. Sixteen studies were included in the primary endpoint analysis after excluding all other non-imaging TMR papers. Standardized mean difference was used as the effect size for all quantitative outcomes and log odds ratio was used as the effect size for all binary outcomes. Statistically significant improvements in myocardial perfusion were observed between control and treatment groups in myocardial perfusion at 6-month follow up using PET imaging with a porcine model. However non-significant differences were observed in patients at 3 and 12 months using SPECT, PET or MUGA scans. Both CO2 and Ho:YAG laser systems demonstrated an increase in myocardial perfusion however this effect was not statistically significant. In addition both laser types displayed statistically significant decreases in patient angina at 3, 6 and 12 months but non-significant increases in survival rates and decreases in hospital re-admissions. In order to properly assess myocardial perfusion in TMR subjects, subendocardial perfusion needs to be analyzed via nuclear imaging. PET scans can provide this level of sensitivity and should be utilized in future studies to monitor and detect perfusion changes in lased and non-lased subjects.

  14. Comparative assessment of rest and post-stress left ventricular volumes and left ventricular ejection fraction on gated myocardial perfusion imaging (MPI) and echocardiography in patients with transient ischaemic dilation on adenosine MPI: myocardial stunning or subendocardial hypoperfusion?

    Science.gov (United States)

    Emmett, Louise; Ng, Austin; Ha, Leo; Russo, Robert; Mansberg, Robert; Zhao, Wei; Chow, S Vincent; Kritharides, Leonard

    2012-08-01

    Transient ischaemic dilation (TID) on myocardial perfusion imaging (MPI) is an important finding, conveying a high risk of subsequent cardiac events. However, the mechanism leading to TID on MPI is not well elucidated. This study aimed to determine if TID is due to true LV cavity dilation and ventricular stunning, or is due to relative subendocardial hypoperfusion. 31 patients undergoing single-day Tc-99m adenosine sestamibi MPI were recruited. All had routine ECG-gated single-day rest-stress adenosine MPI, with transthoracic echocardiograms (echo) acquired concurrently at rest, and both immediately, and 2 hours, post-stress. Echocardiography was performed using a Vivid-7 (GE). LV volumes and LVEF were quantified blinded to MPI results, using biplane Simpson method on echo, and quantitatively (including TID) with QGS(®), on MPI. Patients were divided into quartiles for TID, with the top quartile considered TID positive [TID+ 9/31 (TID ratio 1.3 ± 0.09)], and TID negative [TID- 22/31 (TID ratio 1.01 ± 0.04)]. There was good correlation between resting echo and MPI physical measurements (LVEDV r(2) = 0.79, LVESV r(2) = 0.9, and LVEF r(2) = 0.75). On MPI, a significant drop in LVEF was observed between rest and early stress in the TID+ group (56.6% vs 46.5%, P subendocardial hypoperfusion and impaired coronary flow reserve.

  15. Value of quantitative tissue velocity imaging in the detection of regional myocardial function in dogs with acute subendocardial ischemia.

    Science.gov (United States)

    Zhang, Qinyyang; Deng, Youbin; Liu, Yani; Yang, Haoyi; Liu, Bingbing; Shentu, Weihui; Li, Peng

    2008-12-01

    This study evaluated the application of quantitative tissue velocity imaging (QTVI) in assessing regional myocardial systolic and diastolic functions in dogs with acute subendocardial ischemia. Animal models of subendocardial ischemia were established by injecting microspheres (about 300 microm in diameter) into the proximal end of left circumflex coronary artery in 11 hybrid dogs through cannulation. Before and after embolization, two-dimensional echocardiography, QTVI and real-time myocardial contrast echocardiography (RT-MCE) via intravenous infusion of self-made microbubbles, were performed, respectively. The systolic segmental wall thickening and subendocardial myocardial longitudinal velocities of risk segments before and after embolization were compared by using paired t analysis. The regional myocardial video intensity versus contrast time could be fitted to an exponential function: y=A.(1-exp(-beta.t)), in which the product of A and beta provides a measure of myocardial blood flow. RT-MCE showed that subendocardial normalized A.beta was decreased markedly from 0.99+/-0.19 to 0.35+/-0.11 (Psubendocardial myocardium to subepicardial myocardium in these segments was significantly decreased from 1.10+/-0.10 to 0.31+/-0.07 (P0.05), the longitudinal peak systolic velocities (Vs) and early-diastolic peak velocities (Ve) recorded by QTVI were declined significantly (Psubendocardial velocity curves during isovolumic relaxation predominantly showed positive waves, whereas they mainly showed negative waves before the embolization. This study demonstrates that QTVI can more sensitively and accurately detect abnormal regional myocardial function and post-systolic systole caused by acute subendocardial ischemia.

  16. [A case of left atria subendocardial thrombus with 
sick sinus syndrome].

    Science.gov (United States)

    Liang, Xiongfei; Yang, Yifeng

    2016-09-28

    The clinical data for a patient with sick sinus syndrome was retrospectively analyzed. The patient was treated because of his heart palpitations and the increased chest pain. The patient admitted to the hospital under consideration for the left atrial tumor dependent on the echocardiography findings. After the CT scan and the dynamic ECG examination, the patient successfully underwent the left atrial tumor resection, atrial septal repair and cardiac pacing lead installation. The postoperative pathological diagnosis showed that the infective endocarditis and left atrial thrombus in left atrium was cured. The patient was discharged after postoperative anti-inflammatory therapy. By analyzing the reasons for misdignosis before or during surgery, the possible mechanisms for left atrial subendocardial thrombus have been found. This study suggests that it is necessary to combine imaging diagnosis and clinical observations to distinguish tumor from excrescence.

  17. Fine structure of subendocardial (Purkinje) cells of the insect-eating bat (Pipistrellus pipistrellus).

    Science.gov (United States)

    Ayettey, A S; Tagoe, C N; Yates, R D

    1990-01-01

    Subendocardial cells of the right ventricular myocardium of the West African bat, Pipistrellus pipistrellus, were investigated at the ultrastructural level. The prominent features of these cells include a well-developed T-tubule system and numerous mitochondria with closely packed cristae. Additionally, the cells display large stores of lipid bodies. These unusual features confirm that Purkinje cells are heterogeneous in structural detail. From the paucity and poor structure of myofibrils of these cells, it is likely that the T-tubules may have a primary nutritional role in the regulation of electrolytes in an animal in which the cardiac cycle is particularly rapid. The well-developed mitochondria and the large stores of lipid bodies are appropriate for such active cells in which metabolism is probably of the aerobic type. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:2074228

  18. Endotoxemic myocardial dysfunction: subendocardial collagen deposition related to coronary driving pressure.

    Science.gov (United States)

    Soriano, Francisco Garcia; Guido, Maria Carolina; Barbeiro, Hermes Vieira; Caldini, Elia Garcia; Lorigados, Clara Batista; Nogueira, Antonio Carlos

    2014-11-01

    Sepsis impairs the autoregulation of myocardial microcirculatory blood flow, but whether this impairment is correlated with myocardial remodeling is unknown. This study investigated the role of coronary driving pressure (CDP) as a determinant of microcirculatory blood flow and myocardial fibrosis in endotoxemia and sepsis. The study is composed of two parts: a prospective experimental study and an observational clinical study. The experimental study was performed on male Wistar rats weighing 300 to 320 g. Endotoxemia was induced in rats by lipopolysaccharide (LPS) injection (10 mg·kg intraperitoneally). Hemodynamic evaluation was performed 1.5 to 24 h after LPS injection by measuring the mean arterial pressure, CDP, left ventricular end-diastolic pressure, dP/dtmax, and dP/dtmin. Microspheres were also infused into the left ventricle to measure myocardial blood flow, and myocardial tissue was histologically assessed to analyze collagen deposition. The CDP, mean arterial pressure, and myocardial blood flow were reduced by 55%, 30%, and 70%, respectively, in rats 1.5 h after LPS injection compared with phosphate buffer saline injection (P subendocardial blood flow (r = 0.73) and fibrosis (r = 0.8). Left ventricular function was significantly impaired in the LPS-treated rats, as demonstrated by dP/dtmax (6,155 ± 455 vs. 3,746 ± 406 mmHg·s, baseline vs. LPS; P subendocardial blood flow was positively correlated with CDP, and higher CDP was negatively correlated with myocardial collagen deposition. Thus, early reductions in myocardial blood flow and CDP facilitate late myocardial fibrosis in rats and likely in humans.

  19. A Rare Case of Hypertrophic Cardiomyopathy with Subendocardial Late Gadolinium Enhancement in an Apical Aneurysm with Thrombus

    Directory of Open Access Journals (Sweden)

    Yusuke Morita

    2014-01-01

    Full Text Available The mechanisms responsible for the development of apical aneurysms in cases of hypertrophic cardiomyopathy (HCM are currently unclear but likely involve multiple factors. Here, we present a case of HCM with marked subendocardial fibrosis involving the apical and proximal portions of the left ventricle. A 71-year-old man with left ventricular hypertrophy presented with signs and symptoms of heart failure. The presence of asymmetrical left ventricular hypertrophy and bilateral, thickened ventricular walls with an apical aneurysm on transthoracic echocardiography suggested a diagnosis of HCM with ventricular dysfunction. No intraventricular pressure gradients with obstruction were identified. Late gadolinium enhancement (LGE with cardiac magnetic resonance imaging and endomyocardial biopsies showed subendocardial fibrosis involving the apical aneurysm and proximal portion. Whereas LGE in a transmural pattern is commonly observed in HCM apical aneurysms, subendocardial LGE, as noted in the present case, is a relatively rare occurrence. Thus, the present case may provide unique insights into the adverse remodeling process and formation of apical aneurysms in cases of HCM.

  20. A rare case of hypertrophic cardiomyopathy with subendocardial late gadolinium enhancement in an apical aneurysm with thrombus.

    Science.gov (United States)

    Morita, Yusuke; Kato, Takao; Okano, Mitsumasa; Su, Kanae; Kimura, Masahiro; Minamino, Eri; Nakane, Eisaku; Izumi, Toshiaki; Miyamoto, Shoichi; Haruna, Tetsuya; Inoko, Moriaki

    2014-01-01

    The mechanisms responsible for the development of apical aneurysms in cases of hypertrophic cardiomyopathy (HCM) are currently unclear but likely involve multiple factors. Here, we present a case of HCM with marked subendocardial fibrosis involving the apical and proximal portions of the left ventricle. A 71-year-old man with left ventricular hypertrophy presented with signs and symptoms of heart failure. The presence of asymmetrical left ventricular hypertrophy and bilateral, thickened ventricular walls with an apical aneurysm on transthoracic echocardiography suggested a diagnosis of HCM with ventricular dysfunction. No intraventricular pressure gradients with obstruction were identified. Late gadolinium enhancement (LGE) with cardiac magnetic resonance imaging and endomyocardial biopsies showed subendocardial fibrosis involving the apical aneurysm and proximal portion. Whereas LGE in a transmural pattern is commonly observed in HCM apical aneurysms, subendocardial LGE, as noted in the present case, is a relatively rare occurrence. Thus, the present case may provide unique insights into the adverse remodeling process and formation of apical aneurysms in cases of HCM.

  1. The role of first-pass perfusion deficit in the detection of cardiac subendocardial manifestation in patients with autoimmune vasculitis.

    Science.gov (United States)

    Pfeil, Alexander; Lehmann, Gabriele; Böttcher, Joachim; Wolf, Gunter; Hansch, Andreas

    2013-01-01

    This report describes the potential of cardiac magnetic resonance imaging (cMRI) based on myocardial first-pass perfusion imaging in the visualization of cardiac manifestations in autoimmune vasculitis, which in the heart are typically localized at the level of small subendocardial vessels. Two patients with primary or secondary autoimmune vasculitis were investigated in this study. Myocardial first-pass perfusion imaging was performed using an ECG-gated T1-weighted MRI sequence after the injection of intravenous bolus of gadolinium chelate. In both cases, the cMRI showed findings of subendocardial first-pass perfusion deficit (FPPD), a phenomenon so far described as microvascular obstruction (MVO) only in patients with acute cardiac infarction due to thromboembolic obstruction of small myocardial vessels. The two patients showed local subendocardial and myocardial hypoenhancement (characterized by a darker appearance than normal myocardial tissue), which is the typical morphological stigma of FPPD initially after injection of contrast media. The perfusion deficit, although morphologically very similar to the well-known phenomenon of MVO in acute cardiac infarction, was conceivably caused by different vasculitis-specific mechanisms such as occlusion of the microvasculature with erythrocytes, neutrophils and cellular debris. This study indicates that FPPD is useful for the non-invasive assessment of the microvasculature in patients with acute cardiac involvement in primary and secondary vasculitis.

  2. Assessment of subendocardial vs. subepicardial left ventricular twist using tagged MRI images.

    Science.gov (United States)

    Tavakoli, Vahid; Sahba, Nima

    2014-04-01

    The objective of this study is to determine the normal value of 3D left ventricular (LV) twist in subendocardial, mid-wall and subepicardial layers, as well as to study the effects of aging on 3D LV twist by tagged MR motion tracking techniques. Three dimensional motion detection based on 3D tagged MR images is robust to out-of-plane motion error; while 2D motion detection is inherently unable to analyze the 3D cardiac motion and may lead to inaccurate results. The 3D LV volumetric images were acquired in 52 normal adult subjects (aged 21-82) and were analyzed by using 3D HARmonic phase (HARP) technique. HARP technique provided the 3D displacement fields and the displacements were utilized to compute the rotational values. LV twist was defined as apical rotation relative to the basal rotation, in the 3D coordinates. The LV twist values of subendocardial, mid-wall and subepicardial layers were analyzed separately. The measured parameters in this study were: peak apical rotation, peak basal rotation, and peak LV twist. Looking at the apex, the normal LV maintains a clockwise rotation in the LV basal plane and a counterclockwise rotation in the LV apical plane. In general, the apical and basal rotation values increase during the aging process, leading to an increased value of LV twist. Peak epicardial LV twist is (10.4±2.6 degrees) which is lower than the mid-wall LV twist (11.3±2.2 degrees) and endocardial LV twist (12.1±2.6 degrees) in the young group (21-35 years old). Also, peak epicardial LV twist is (12.2±2.6 degrees) which is lower than the mid-wall LV twist (14.4±2.8 degrees) and endocardial LV twist (14.7±2.5 degrees) in the middle aged group (21-35 years old). In a similar way, peak epicardial LV twist is (14.8±2.9 degrees) which is lower than the mid-wall LV twist (15.7±3.6 degrees) and endocardial LV twist (16.7±3.0 degrees) in the old group (50-65 years old). Regarding the older group (more than 65 years old), peak epicardial LV twist is (15.9±3

  3. Endotoxaemic myocardial dysfunction: the role of coronary driving pressure in subendocardial perfusion.

    Science.gov (United States)

    Lorigados, Clara B; Ariga, Suely K; Batista, Tiago R; Velasco, Irineu T; Soriano, Francisco G

    2015-03-01

    To investigate the role of coronary driving pressure (CDP) in myocardial microcirculatory blood flow during sepsis. We hypothesised that in septic shock there is an impaired autoregulation of microcirculation, and blood flow is totally dependent on CDP. We analysed the effect of lipopolysaccharide (LPS)-induced shock on myocardial microcirculation, separating subendocardial and epicardial areas. We then studied the effect of CDP increases using noradrenaline (NOR) or metaraminol (Aramine [ARA]) on myocardial microcirculation and function, and we analysed the effect of volume infusion on CDP and myocardial function. Endotoxaemia was induced in male Wistar rats by an intraperitoneal injection of LPS 10 mg/kg. Animals were divided into a control (CT) group, an LPS-injected group, and an LPS-injected group treated with saline fluid, NOR or ARA. Ninety minutes later, a haemodynamic evaluation was performed. NOR or ARA were used to manage the mean arterial pressure (MAP) and CDP, and we inserted a catheter into the left ventricle to measure cardiac parameters. To measure blood flow in the myocardium and other organs, microspheres were introduced into the left ventricle using an infusion pump. After LPS treatment, left ventricular (LV) systolic function (dP/dt max) and diastolic function (dP/dt min) decreased by 34% and 15%, respectively, and load-independent indices (LV contractility in ejection phase and dP/dt max÷end-diastolic volume) were reduced. The CDP was also reduced (by 58%) in the endotoxaemic rats. Myocardial blood flow was reduced (by 80%) in animals with an MAP≤65 mmHg. NOR increased the CDP (LPS, 38 mmHg [SEM, 2 mmHg]; LPS+NOR, 59 mmHg [SEM, 3 mmHg]) and microcirculatory perfusion (LPS, 2 mL/min/g tissue [SEM, 0.6 mL/min/g]; LPS+NOR, 6.2 mL/min/g [SEM, 0.8 mL/min/g]). ARA was also effective in improve microcirculation but saline volume infusion was ineffective in improving CDP or myocardial function. CDP showed a significant correlation with

  4. Forensic aspect of cause of subendocardial hemorrhage in cardiopulmonary resuscitation cases: chest compression or adrenaline.

    Science.gov (United States)

    Charaschaisri, Werasak; Jongprasartsuk, Kesanee; Rungruanghiranya, Suthat; Kaufman, Larry

    2011-03-01

    Subendocardial hemorrhage (SEH) is a striking feature seen in many forensic autopsy cases. It was believed earlier to represent an agonal phenomenon without any particular reference to the cause of death. However, the latest study showed that even minor SEH might have an influence on cardiac function and might be involved in the mechanism of death. To rule out the possible cause of SEH from defibrillation, autopsies were performed in 240 adults admitted to Department of Forensic Medicine, Faculty of Medicine, Srinakarinwirot University and Department of Forensic Medicine, Faculty of Medicine, Chulalongkorn University between July 2006 and June 2008. All the subjects were subdivided into 2 groups: one group receiving resuscitation and the other group receiving no resuscitation. In the former group, 76 patients had attempted cardiopulmonary resuscitation with adrenaline and 44 patients without adrenaline. While in the latter group, 120 patients received no resuscitation attempt. Approximately, 43.4% of resuscitation with adrenaline cases (33/76) demonstrated SEH in contrast to 4 cases of resuscitation without adrenaline (9.1%, P < 0.05). This demonstrates an increasing trend of SEH in cases with prolonged resuscitation and higher level of adrenaline utilizations.

  5. Cardioscopic observation of subendocardial microvessels in patients with coronary artery disease.

    Science.gov (United States)

    Uchida, Yasuto; Kanai, Masahito; Maezawa, Yuko; Maezawa, Yoshiro; Shirai, Seiichiro; Nakagawa, Osamu; Uchida, Yasumi

    2011-01-01

    Coronary microvessels play a direct and critical role in determining the extent and severity of myocardial ischemia and cardiac function. However, because direct observation has never been performed in vivo, the functional properties of the individual microvesssels in patients with coronary artery disease remain unknown. Subendocardial coronary microvessels were observed by cardioscopy in 149 successive patients with coronary artery disease (81 with stable angina and 68 with old myocardial infarction). Twenty-four arterial microvessels (AMs) and 27 venous microvessels (VMs) were observed in the left ventricular subendocardium. All 12 AMs and 13 of 14 VMs that were located in normokinetic-to-hypokinetic left ventricular wall segments were filled with blood during diastole and were collapsed during systole. In contrast, 8 of 12 AMs and 9 of 13 VMs that were located in akinetic-to-dyskinetic wall segments were filled with blood during systole and were collapsed during diastole. There were no significant correlations between the timing of blood filling and the severity of coronary stenosis and collateral development. In patients with coronary artery disease, the timing of blood filling of AMs and VMs was dependent on the regional left ventricular contractile state; during diastole when contraction was preserved and during systole when it was not. It remains to be elucidated whether and how blood filling is disturbed in other categories of heart disease.

  6. Feasibility of subendocardial and subepicardial myocardial perfusion measurements in healthy normals with (15)O-labeled water and positron emission tomography.

    Science.gov (United States)

    Vermeltfoort, Ilse A; Raijmakers, Pieter G; Lubberink, Mark; Germans, Tjeerd; van Rossum, Albert C; Lammertsma, Adriaan A; Knaapen, Paul

    2011-08-01

    Positron emission tomography (PET) enables robust and reproducible measurements of myocardial blood flow (MBF). However, the relatively limited resolution of PET till recently prohibited distinction between the subendocardial and the subepicardial layers in non-hypertrophied myocardium. Recent developments in hard- and software, however, have enabled to identify a transmural gradient difference in animal experiments. The aim of this study is to determine the feasibility of subendocardial and subepicardial MBF in normal human hearts assessed with (15)O-labeled water PET. Twenty-seven healthy subjects (mean age 41 ± 13 years; 11 men) were studied with (15)O-labeled water PET to quantify resting and hyperaemic (adenosine) MBF at a subendocardial and subepicardial level. In addition, cardiac magnetic resonance imaging was performed to determine left ventricular (LV) volumes and function. Mean rest MBF was 1.46 ± 0.49 in the subendocardium, and 1.14 ± 0.342 mL · min(-1) · g(-1) in the subepicardium (P subendocardial level. (15)O-labeled water PET enables MBF measurements with distinction of the subendocardial and subepicardial layers in the normal human heart and correlates with LVEDVI. This PET technique may prove useful in evaluating patients with signs of ischaemia due to coronary artery disease or microvascular dysfunction.

  7. The effects of halothane, isoflurane, and sevoflurane on Ca2+ current and transient outward K+ current in subendocardial and subepicardial myocytes from the rat left ventricle.

    Science.gov (United States)

    Rithalia, Amber; Hopkins, Philip M; Harrison, Simon M

    2004-12-01

    Halothane, isoflurane, and sevoflurane abbreviate ventricular action potential duration (APD), and for halothane this effect is greater in the subendocardium than in the subepicardium. In this study we investigated mechanisms underlying the regional effects of these anesthetics on APD. The effect of 0.6 mM halothane, isoflurane, and sevoflurane on the action potential, L-type Ca(2+) current, transient outward K(+) current (I(to)), and steady-state current was recorded in rat left ventricular subendocardial and subepicardial myocytes. Halothane and isoflurane (but not sevoflurane) reduced APD significantly (P subendocardial than subepicardial myocytes. Peak L-type Ca(2+) current did not differ between regions and, compared with control, was reduced significantly in both regions by 40% (P subendocardial (1.12 +/- 0.05 nA) myocytes. In subepicardial myocytes, peak I(to) was reduced significantly by halothane (P subendocardial myocytes with the three anesthetics. The steady-state current was increased significantly (P subendocardial myocytes by halothane and isoflurane could underlie their transmural effects on APD.

  8. Comparison of initial cell retention and clearance kinetics after subendocardial or subepicardial injections of endothelial progenitor cells in a canine myocardial infarction model.

    Science.gov (United States)

    Mitchell, Andrea J; Sabondjian, Eric; Sykes, Jane; Deans, Lela; Zhu, Wendy; Lu, Xiangru; Feng, Qingping; Prato, Frank S; Wisenberg, Gerald

    2010-03-01

    Neither intravenous nor intracoronary routes provide targeted stem cell delivery to recently infarcted myocardium in sufficient quantities. Direct routes appear preferable. However, most prior studies have used epicardial injections, which are not practical for routine clinical use. The objective of this study was to compare cell retention and clearance kinetics between a subepicardial and a subendocardial technique. We evaluated 7 dogs with each technique, using (111)In-tropolone-labeled endothelial progenitor cells and serial SPECT/CT for 15 d after injection. In vivo indium imaging demonstrated comparable degrees of retention: 57% +/- 15% for the subepicardial injections and 54% +/- 26% for the subendocardial injections. Clearance half-lives were also similar at 69 +/- 26 and 60 +/- 21 h, respectively. This study demonstrates that subendocardial injections, clinically more practical, show clearance kinetics comparable to those of subepicardial injections and will facilitate the ultimate clinical use of this treatment modality.

  9. Effect of Diffuse Subendocardial Hypoperfusion on Left Ventricular Cavity Size by 13N-Ammonia Perfusion PET in Patients With Hypertrophic Cardiomyopathy.

    Science.gov (United States)

    Yalçin, Hulya; Valenta, Ines; Yalçin, Fatih; Corona-Villalobos, Celia; Vasquez, Nestor; Ra, Joshua; Kucukler, Nagehan; Tahari, Abdel; Pozios, Iraklis; Zhou, Yun; Pomper, Martin; Abraham, Theodore P; Schindler, Thomas H; Abraham, M Roselle

    2016-12-15

    Vasodilator-induced transient left ventricular (LV) cavity dilation by positron emission tomography (PET) is common in patients with hypertrophic cardiomyopathy (HC). Because most patients with PET-LV cavity dilation lack obstructive epicardial coronary artery disease, we hypothesized that vasodilator-induced subendocardial hypoperfusion resulting from microvascular dysfunction underlies this result. To test this hypothesis, we quantified myocardial blood flow (MBF) (subepicardial, subendocardial, and global MBF) and left ventricular ejection fraction (LVEF) in 104 patients with HC without significant coronary artery disease, using 13NH3-PET. Patients with HC were divided into 2 groups, based on the presence/absence of LV cavity dilation (LVvolumestress/LVvolumerest >1.13). Transient PET-LV cavity dilation was evident in 52% of patients with HC. LV mass, stress left ventricular outflow tract gradient, mitral E/E', late gadolinium enhancement, and prevalence of ischemic ST-T changes after vasodilator were significantly higher in patients with HC with LV cavity dilation. Baseline LVEF was similar in the 2 groups, but LV cavity dilation+ patients had lower stress-LVEF (43 ± 11 vs 53 ± 10; p subendocardial region (1.6 ± 0.7 vs 2.3 ± 1.0 ml/min/g; p subendocardial perfusion, was similar at rest in the 2 groups. Notably, LV cavity dilation+ patients had lower stress-transmural perfusion gradients (0.85 ± 0.22, LV cavity dilation+ vs 1.09 ± 0.39, LV cavity dilation-; p subendocardial hypoperfusion. The stress-transmural perfusion gradient, global myocardial flow reserve, and stress-LVEF were associated with LV cavity dilation. In conclusion, diffuse subendocardial hypoperfusion and myocardial ischemia resulting from microvascular dysfunction contribute to development of transient LV cavity dilation in HC. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Differentiation of subendocardial and transmural infarction using two-dimensional strain rate imaging to assess short-axis and long-axis myocardial function.

    Science.gov (United States)

    Chan, Jonathan; Hanekom, Lizelle; Wong, Chiew; Leano, Rodel; Cho, Goo-Yeong; Marwick, Thomas H

    2006-11-21

    This study sought to differentiate the transmural extent of infarction (TME) by assessment of the short-axis and long-axis function of the left ventricle (LV) using 2-dimensional (2D) strain. The differentiation of subendocardial infarction from transmural infarction has significant prognostic and clinical implications. Contrast-enhanced magnetic resonance imaging (CE-MRI) and dobutamine stress echocardiography (DBE) were performed in 80 patients (age 63 +/- 10 years) with chronic ischemic LV dysfunction. Myocardial function was assessed in the short axis at the midventricular level using peak strain rate (SR) and strain (S) in circumferential and radial dimensions, and was assessed in the long axis using longitudinal SR and S. Wall motion analysis was performed during DBE to assess for contractile reserve. Transmural infarct segments had lower circumferential S (-10.7 +/- 6.3) and SR (-1.0 +/- 0.4) than subendocardial infarcts (S: -15.4 +/- 7.0, p subendocardial infarct segments had similar radial S and SR. Subendocardial infarct segments showed significant reduction of longitudinal S (-13.2 +/- 5.6) and SR (-0.91 +/- 0.45) compared with normal myocardium (S: -17.8 +/- 5.4, p subendocardial and transmural infarct segments (p = 0.09). Wall motion analysis by DBE could not identify subendocardial infarction on CE-MRI (TME 1% to 50%: DBE scar 38%, DBE viable 38%, DBE ischemic 24%, p = NS). The combined assessment of long-axis and short-axis function using 2D strain may be used to identify TME.

  11. Late gadolinium enhancement in cardiac amyloidosis: attributable both to interstitial amyloid deposition and subendocardial fibrosis caused by ischemia.

    Science.gov (United States)

    Hashimura, Hiromi; Ishibashi-Ueda, Hatsue; Yonemoto, Yumiko; Ohta-Ogo, Keiko; Matsuyama, Taka-Aki; Ikeda, Yoshihiko; Morita, Yoshiaki; Yamada, Naoaki; Yasui, Hiroki; Naito, Hiroaki

    2016-06-01

    Gadolinium contrast agents used for late gadolinium enhancement (LGE) distribute in the extracellular space. Global diffuse myocardial LGE pronounced in the subendocardial layers is common in cardiac amyloidosis. However, the pathophysiological basis of these findings has not been sufficiently explained. A 64-year-old man was admitted to our hospital with leg edema and nocturnal dyspnea. Bence Jones protein was positive in the urine, and an endomyocardial and skin biopsy showed light-chain (AL) amyloidosis. He died of ventricular fibrillation 3 months later. 9 days before death, the patient was examined by cardiac magnetic resonance (CMR) imaging on a 3-T system. We acquired LGE data at 2, 5, 10, and 20 min after the injection of gadolinium contrast agents, with a fixed inversion time of 350 ms. Myocardial LGE developed sequentially. The myocardium was diffusely enhanced at 2 min, except for the subendocardium, but LGE had extended to almost the entire left ventricle at 5 min and predominantly localized to the subendocardial region at 10 and 20 min. An autopsy revealed massive and diffused amyloid deposits in perimyocytes throughout the myocardium. Old and recent ischemic findings, such as replacement fibrosis and coagulative myocyte necrosis, were evident in the subendocardium. In the intramural coronary arteries, mild amyloid deposits were present within the subepicardial to the mid layer of the left ventricle, but no stenotic lesions were evident. However, capillaries were obstructed by amyloid deposits in the subendocardium. In conclusion, the late phase of dynamic LGE (at 10 and 20 min) visualized in the subendocardium corresponded to the interstitial amyloid deposition and subendocardial fibrosis caused by ischemia in our patient.

  12. Subendocardial increase in reactive oxygen species production affects regional contractile function in ischemic heart failure.

    Science.gov (United States)

    Andre, Lucas; Fauconnier, Jeremy; Reboul, Cyril; Feillet-Coudray, Christine; Meschin, Pierre; Farah, Charlotte; Fouret, Gilles; Richard, Sylvain; Lacampagne, Alain; Cazorla, Olivier

    2013-03-20

    Heart failure (HF) is characterized by regionalized contractile alterations resulting in loss of the transmural contractile gradient across the left ventricular free wall. We tested whether a regional alteration in mitochondrial oxidative metabolism during HF could affect myofilament function through protein kinase A (PKA) signaling. Twelve weeks after permanent left coronary artery ligation that induced myocardial infarction (MI), subendocardial (Endo) cardiomyocytes had decreased activity of complex I and IV of the mitochondrial electron transport chain and produced twice more superoxide anions than sham Endo and subepicardial cells. This effect was associated with a reduced antioxidant activity of superoxide dismutase and Catalase only in MI Endo cells. The myofilament contractile properties (Ca(2+) sensitivity and maximal tension), evaluated in skinned cardiomyocytes, were also reduced only in MI Endo myocytes. Conversely, in MI rats treated with the antioxidant N-acetylcysteine (NAC) for 4 weeks, the generation of superoxide anions in Endo cardiomyocytes was normalized and the contractile properties of skinned cardiomyocytes restored. This effect was accompanied by improved in vivo contractility. The beneficial effects of NAC were mediated, at least, in part, through reduction of the PKA activity, which was higher in MI myofilaments, particularly, the PKA-mediated hyperphosphorylation of cardiac Troponin I. The Transmural gradient in the mitochondrial content/activity is lost during HF and mediates reactive oxygen species-dependent contractile dysfunction. Regionalized alterations in redox signaling affect the contractile machinery of sub-Endo myocytes through a PKA-dependent pathway that contributes to the loss of the transmural contractile gradient and impairs global contractility.

  13. Dipyridamole-loading scintigraphy in patients with subendocardial infarction using single photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kiyoo; Masuda, Masanosuke (Hoju Memorial Hospital, Tatsunokuchi, Ishikawa (Japan)); Bunkou, Hisashi

    1988-12-01

    To detect myocardial lesions in patients with subendocardial (nontransmural) infarction, myocardial perfusion images of thallium-201 (Tl-201), using single photon emission computed tomography, were obtained in 17 patients during and three hours after coronary vasodilatation induced by the administration of dipyridamole. Controls consisted of 28 patients with transmural infarction and 11 with angina pectoris. Dipyridamole was infused intravenously at a rate of 0.142 mg/kg per min for four min, and the washout rate of Tl-201 was calculated by the segmental ROI method. Many patients with nontransmural infarction exhibited various Tl-201 myocardial perfusion images. The prevalence of redistribution among patients with nontransmural infarction was 88.2% (15 of 17), and its reverse redistribution was 64.7% (11 of 17). Every subject exhibited a number of abnormal Tl-201 myocardial perfusion images. In patients with nontransmural infarction the occurence of reverse redistribution images was significantly higher (64.7%) compared to those with transmural infarction (10.7%), and the occurrence of redistribution images was significantly higher (88.2%) compared to those with angina pectoris (45.5%). The abnormal perfusion images most frequently present in the areas corresponding to the sites of ST-T changes on ECG were reverse redistribution (26.7%), redistribution (17.3%), and fixed defect (6.7%) in order. The phenomenon of reverse redistribution images was found irrespective of stenotic coronary artery lesions on selective coronary angiography. Most areas corresponding to the sites of reverse redistribution showed ST-T changes on ECG and high washout rates of Tl-201. (J.P.N.).

  14. Viability, invariance and applications

    CERN Document Server

    Carja, Ovidiu; Vrabie, Ioan I

    2007-01-01

    The book is an almost self-contained presentation of the most important concepts and results in viability and invariance. The viability of a set K with respect to a given function (or multi-function) F, defined on it, describes the property that, for each initial data in K, the differential equation (or inclusion) driven by that function or multi-function) to have at least one solution. The invariance of a set K with respect to a function (or multi-function) F, defined on a larger set D, is that property which says that each solution of the differential equation (or inclusion) driven by F and issuing in K remains in K, at least for a short time.The book includes the most important necessary and sufficient conditions for viability starting with Nagumo's Viability Theorem for ordinary differential equations with continuous right-hand sides and continuing with the corresponding extensions either to differential inclusions or to semilinear or even fully nonlinear evolution equations, systems and inclusions. In th...

  15. Identification and further differentiation of subendocardial and transmural myocardial infarction by fast strain-encoded (SENC) magnetic resonance imaging at 3.0 Tesla.

    Science.gov (United States)

    Oyama-Manabe, Noriko; Ishimori, Naoki; Sugimori, Hiroyuki; Van Cauteren, Marc; Kudo, Kohsuke; Manabe, Osamu; Okuaki, Tomoyuki; Kamishima, Tamotsu; Ito, Yoichi M; Tsutsui, Hiroyuki; Tha, Khin Khin; Terae, Satoshi; Shirato, Hiroki

    2011-11-01

    To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction.

  16. Identification and further differentiation of subendocardial and transmural myocardial infarction by fast strain-encoded (SENC) magnetic resonance imaging at 3.0 tesla

    Energy Technology Data Exchange (ETDEWEB)

    Oyama-Manabe, Noriko; Sugimori, Hiroyuki; Kamishima, Tamotsu; Tha, Khin Khin; Terae, Satoshi; Shirato, Hiroki [Hokkaido University Hospital, Department of Diagnostic and Interventional Radiology, Sapporo (Japan); Ishimori, Naoki; Tsutsui, Hiroyuki [Hokkaido University Graduate School of Medicine, Department of Cardiovascular Medicine, Sapporo (Japan); Van Cauteren, Marc; Okuaki, Tomoyuki [Philips Healthcase, MR Clinical Science, Tokyo (Japan); Kudo, Kohsuke [Iwate Medical University, Advanced Medical Research Center, Morioka (Japan); Manabe, Osamu [Hokkaido University Hospital, Department of Nuclear Medicine, Sapporo (Japan); Ito, Yoichi M. [Hokkaido University Graduate School of Medicine, Hokkaido Organization for Translational Research, Sapporo (Japan)

    2011-11-15

    To investigate whether subendocardial and transmural myocardial infarction can be identified and differentiated using the peak circumferential and longitudinal strains measured by fast strain-encoded (SENC). Nineteen patients with ischemic heart diseases underwent imaging with fast SENC and late gadolinium enhancement (LGE) MRI at 3 T. Fast SENC measurements were performed in three short-axis slices (basal, mid-ventricular and apical levels) and one long-axis view (four-chamber) to assess peak longitudinal and circumferential systolic strains. All patients showed myocardial infarction with an average of 7 positive LGE segments. A total of 304 segments for longitudinal strains (LS) and 114 segments for circumferential strains (CS) could be analysed. Positive LGE segments showed lower peak CS and LS compared with the no LGE segments (P < 0.0001 for both). Segments with subendocardial infarction showed reduced CS and LS compared with the no LGE segments (P < 0.0001 for both). There was a significant difference in CS between subendocardial and transmural infarct segments (P = 0.03), but no significant difference in LS between them (P = 0.64). Fast SENC can identify old myocardial infarction and differentiate subendocardial from transmural infarction. (orig.)

  17. First-pass myocardial perfusion MRI with reduced subendocardial dark-rim artifact using optimized Cartesian sampling.

    Science.gov (United States)

    Zhou, Zhengwei; Bi, Xiaoming; Wei, Janet; Yang, Hsin-Jung; Dharmakumar, Rohan; Arsanjani, Reza; Bairey Merz, C Noel; Li, Debiao; Sharif, Behzad

    2017-02-01

    The presence of subendocardial dark-rim artifact (DRA) remains an ongoing challenge in first-pass perfusion (FPP) cardiac magnetic resonance imaging (MRI). We propose a free-breathing FPP imaging scheme with Cartesian sampling that is optimized to minimize the DRA and readily enables near-instantaneous image reconstruction. The proposed FPP method suppresses Gibbs ringing effects-a major underlying factor for the DRA-by "shaping" the underlying point spread function through a two-step process: 1) an undersampled Cartesian sampling scheme that widens the k-space coverage compared to the conventional scheme; and 2) a modified parallel-imaging scheme that incorporates optimized apodization (k-space data filtering) to suppress Gibbs-ringing effects. Healthy volunteer studies (n = 10) were performed to compare the proposed method against the conventional Cartesian technique-both using a saturation-recovery gradient-echo sequence at 3T. Furthermore, FPP imaging studies using the proposed method were performed in infarcted canines (n = 3), and in two symptomatic patients with suspected coronary microvascular dysfunction for assessment of myocardial hypoperfusion. Width of the DRA and the number of DRA-affected myocardial segments were significantly reduced in the proposed method compared to the conventional approach (width: 1.3 vs. 2.9 mm, P subendocardial perfusion defects and patient results were consistent with the gold-standard invasive test. The proposed free-breathing Cartesian FPP imaging method significantly reduces the prevalence of severe DRAs compared to the conventional approach while maintaining similar resolution and image quality. 2 J. Magn. Reson. Imaging 2017;45:542-555. © 2016 International Society for Magnetic Resonance in Medicine.

  18. Low coronary driving pressure early in the course of myocardial infarction is associated with subendocardial remodelling and left ventricular dysfunction

    Science.gov (United States)

    Koike, Marcia Kiyomi; De Carvalho Frimm, Clovis; Cúri, Mariana

    2007-01-01

    Subendocardial remodelling of the left ventricular (LV) non-infarcted myocardium has been poorly investigated. Previously, we have demonstrated that low coronary driving pressure (CDP) early postinfarction was associated with the subsequent development of remote subendocardial fibrosis. The present study aimed at examining the role of CDP in LV remodelling and function following infarction. Haemodynamics were performed in Wistar rats immediately after myocardial infarction (MI group) or sham surgery (SH group) and at days 1, 3, 7 and 28. Heart tissue sections were stained with HE, Sirius red and immunostained for α-actin. Two distinct LV regions remote to infarction were examined: subendocardium (SE) and interstitium (INT). Myocyte necrosis, leucocyte infiltration, myofibroblasts and collagen volume fraction were determined. Compared with SH, MI showed lower CDP and LV systolic and diastolic dysfunction. Necrosis was evident in SE at day 1. Inflammation and fibroplasia predominated in SE as far as day 7. Fibrosis was restricted to SE from day 3 on. Inflammation occurred in INT at days 1 and 3, but at a lower grade than in SE. CDP correlated inversely with SE necrosis (r = −0.65, P = 0.003, at day 1), inflammation (r = −0.76, P < 0.001, at day 1), fibroplasia (r = −0.47, P = 0.04, at day 7) and fibrosis (r = −0.83, P < 0.001, at day 28). Low CDP produced progressive LV expansion. Necrosis at day 1, inflammation at days 3 and 7, and fibroplasia at day 7 correlated inversely with LV function. CDP is a key factor to SE integrity and affects LV remodelling and function following infarction. PMID:17696909

  19. Viability of smallholder dairying in Wedza, Zimbabwe.

    Science.gov (United States)

    Zvinorova, Plaxedis Ivy; Halimani, Tinyiko Edward; Mano, Renneth T; Ngongoni, Nobbert Takarwirwa

    2013-04-01

    Viability differences in smallholder dairy farming are a result of differences in access to markets and services. It is hypothesized that innovations that improve productivity and market linkages also improve returns and viability. The viability of smallholder dairying in Wedza was characterised by interviewing 52 households using semi-structured questionnaires. Information on demographics, production, marketing, livestock numbers, assets and constraints was obtained. Farmers were resource-constrained with differences in access to resources. The highly resourced farmers had higher milk output and numbers of livestock. Almost 40 % of the households were female-headed, and these dominated the poor category. Household sizes ranged from 4 to 13 persons. Milk off-take was low (3.7 ± 0.53 l/cow/day), due to various constraints. Only rich farmers had viable enterprises in purely financial terms. Per litre cost of milk was more than selling price (US$0.96) for most farmers except the relatively rich. Operating ratios were 1.7, 0.6, 1.4 and 1.1 for the poor, rich, sub-centre and milk collection centre farmers, respectively. This means incomes from the dairy activities did not cover costs. Sensitivity analysis indicated that increases in total variable costs and labour reduced returns. Milk production and viability were influenced by access to resources and markets.

  20. Determination of pollen viability, germination ratios and morphology ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... Alburquerque N, Burgos L, Sedgley M, Egea J (2004). Contributing to the knowledge of the fertilisation process in four apricot cultivars. Sci. Hortic. 102: 387-396. Asma BM (2000). Apricot production (in Turkish). Evin Press,. Malatya. Asma BM, Birhanlı O (2004). Mişmiş (in Turkish). Evin Press,. Malatya.

  1. Determination of pollen viability, germination ratios and morphology ...

    African Journals Online (AJOL)

    While the differences in anther number/flower were not significantly different among genotypes, there were significant differences in pollen number for both anther and flower bases. 44- 2005-01 and Canino had the highest pollen numbers. Pollen morphology was also evaluated using a Scanning Electron Microscope ...

  2. High-resolution MRI for the quantitative evaluation of subendocardial and subepicardial perfusion under pharmalogical stress and at rest; Hochaufgeloeste quantitative MR-tomografische Bestimmung der subendo- und subepimyokardialen Perfusion unter Stress und in Ruhe

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, C.O.; Savio, K. del; Brackertz, A.; Beer, M.; Hahn, D.; Koestler, H. [Wuerzburg Univ. (Germany). Inst. fuer Roentgendiagnostik

    2007-09-15

    Purpose: MR stress perfusion imaging of the heart allows the quantification of myocardial perfusion and the evaluation of myocardial perfusion reserve (MPR) and the ratio of subendocardial to subepicardial perfusion at rest and under adenosine stress. The aim of this study was to evaluate a high-resolution GRAPPA sequence for quantitative MR first pass perfusion imaging in healthy volunteers. Materials and Methods: First pass stress and rest perfusion studies were performed on 10 healthy volunteers using a 1.5 T MR scanner with a multislice SR-TrueFISP first pass perfusion sequence with a GRAPPA algorithm (acceleration factor 3) in prebolus technique and an image resolution of 1.8 x 1.8 mm. For the comparison group, we examined 12 different healthy volunteers with a standard first pass perfusion SR-TrueFISP sequence using a resolution of 2.7 x 3.3 mm. Myocardial contours were manually delineated followed by an automatic division of the myocardium into two rings with an equal thickness for the subendo- and subepicardial layer. Eight sectors per slice were evaluated using contamination and baseline correction. Results: Using the GRAPPA sequence, the ratio of subendo- to subepimyocardial perfusion was 1.18 {+-} 0.32 for the examination at rest. Under pharmacologically induced stress, the ratio was 1.08 {+-} 0.27. For the standard sequence the ratio was 1.15 {+-} 0.28 at rest and 1.11 {+-} 0.33 under stress. For the high resolution sequence higher mean values for the subendo- to subepimyocardial ratio were obtained with comparable standard deviations. The difference between the sequences was not significant. Conclusion: The evaluation of subendomyocardial and subepimyocardial perfusion is feasible with a high-resolution first pass perfusion sequence. The use of a higher resolution to avoid systematic error leads to increased image noise. However, no relevant reduction in the quantitative perfusion values under stress and at rest was able to be depicted. (orig.)

  3. Viability of Baylisascaris procyonis Eggs

    OpenAIRE

    Shira C Shafir; Sorvillo, Frank J.; Sorvillo, Teresa; Eberhard, Mark L.

    2011-01-01

    Infection with Baylisascaris procyonis roundworms is rare but often fatal and typically affects children. We attempted to determine parameters of viability and methods of inactivating the eggs of these roundworms. Loss of viability resulted when eggs were heated to 62°C or desiccated for 7 months but not when frozen at –15°C for 6 months.

  4. Subendocardial motion in hypertrophic cardiomyopathy: assessment from long- and short-axis views by pulsed tissue Doppler imaging

    Science.gov (United States)

    Tabata, T.; Oki, T.; Yamada, H.; Abe, M.; Onose, Y.; Thomas, J. D.

    2000-01-01

    BACKGROUND: Tissue Doppler imaging (TDI) is a recently developed technique that allows the instantaneous measurement of intrinsic regional myocardial motion velocity. Pulsed TDI is capable of separately assessing left ventricular (LV) regional motion velocity caused by circumferential and longitudinal fiber contraction. This particular feature of function is still controversial in patients with hypertrophic cardiomyopathy (HC). METHODS: To better characterize intrinsic circumferential and longitudinal LV systolic myocardial function in HC, we used pulsed TDI to measure short- and long-axis LV motion velocities, respectively. The subendocardial motion velocity patterns at the middle of the LV posterior wall (PW) and ventricular septum (IVS) in LV parasternal and apical long-axis views were recorded by pulsed TDI in 19 patients with nonobstructive HC and in 21 normal controls (NC). RESULTS: Peak short- and long-axis systolic subendocardial velocities in both the LV PW and IVS were significantly smaller in the HC group than in the NC group, and the time to peak velocity was significantly delayed. Furthermore, peak PW systolic velocity was significantly greater along the long axis than along the short axis in the NC group (8.8 +/- 1.5 cm/s vs 8.2 +/- 1.4 cm/s, P <.05), whereas the opposite was observed in the HC group (6.1 +/- 1.2 cm/s vs 7.5 +/- 1.0 cm/s, P <.0001). No significant differences were found in either group between the long- and short-axis IVS velocities (HC: 5.9 +/- 1.4 cm/s vs 5.5 +/- 1.3 cm/s; NC: 7.8 +/- 1.3 cm/s vs 7.9 +/- 1.6 cm/s). CONCLUSIONS: By using the capability of pulsed TDI for the evaluation of intrinsic myocardial velocity instantaneously in a specific region and direction, we found impairment of LV myocardial systolic function in patients with HC not only in the hypertrophied IVS but also in the nonhypertrophied LV PW. We also found a greater decrease in LV PW velocities along the long axis than the short axis, suggesting greater

  5. Agreement and disagreement between contrast-enhanced magnetic resonance imaging and nuclear imaging for assessment of myocardial viability

    Energy Technology Data Exchange (ETDEWEB)

    Roes, Stijntje D.; Kaandorp, Theodorus A.M.; Westenberg, Jos J.M.; Lamb, Hildo J.; Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Ajmone Marsan, Nina; Wall, Ernst E. van der; Bax, Jeroen J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Dibbets-Schneider, Petra; Stokkel, Marcel P. [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands)

    2009-04-15

    The purpose of this study was to compare contrast-enhanced MRI and nuclear imaging with {sup 99m}Tc-tetrofosmin and {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) single photon emission computed tomography (SPECT) for assessment of myocardial viability. Included in the study were 60 patients with severe ischaemic left ventricular (LV) dysfunction who underwent contrast-enhanced MRI, {sup 99m}Tc-tetrofosmin and {sup 18}F-FDG SPECT. Myocardial segments were assigned a wall motion score from 0 (normokinesia) to 4 (dyskinesia) and a scar score from 0 (no scar) to 4 (76-100% transmural extent). Furthermore, {sup 99m}Tc-tetrofosmin and {sup 18}F-FDG segmental tracer uptake was categorized from 0 (tracer activity >75%) to 3 (tracer activity <25%). Dysfunctional segments were classified into viability patterns on SPECT: normal perfusion/{sup 18}F-FDG uptake, perfusion/{sup 18}F-FDG mismatch, and mild or severe perfusion/{sup 18}F-FDG match. Minimal scar tissue was observed on contrast-enhanced MRI (scar score 0.4{+-}0.8) in segments with normal perfusion/{sup 18}F-FDG uptake, whereas extensive scar tissue (scar score 3.1{+-}1.0) was noted in segments with severe perfusion/{sup 18}F-FDG match (p < 0.001). High agreement (91%) for viability assessment between contrast-enhanced MRI and nuclear imaging was observed in segments without scar tissue on contrast-enhanced MRI as well as in segments with transmural scar tissue (83%). Of interest, disagreement was observed in segments with subendocardial scar tissue on contrast-enhanced MRI. Agreement between contrast-enhanced MRI and nuclear imaging for assessment of viability was high in segments without scar tissue and in segments with transmural scar tissue on contrast-enhanced MRI. However, evident disagreement was observed in segments with subendocardial scar tissue on contrast-enhanced MRI, illustrating that the nonenhanced epicardial rim can contain either normal or ischaemically jeopardized myocardium. (orig.)

  6. Subendocardial fibrosis in remote myocardium results from reduction of coronary driving pressure during acute infarction in rats

    Directory of Open Access Journals (Sweden)

    Clovis de Carvalho Frimm

    2003-05-01

    Full Text Available OBJECTIVE: To investigate the role of hemodynamic changes occurring during acute MI in subsequent fibrosis deposition within non-MI. METHODS: By using the rat model of MI, 3 groups of 7 rats each [sham, SMI (MI 30%] were compared. Systemic and left ventricular (LV hemodynamics were recorded 10 minutes before and after coronary artery ligature. Collagen volume fraction (CVF was calculated in picrosirius red-stained heart tissue sections 4 weeks later. RESULTS: Before surgery, all hemodynamic variables were comparable among groups. After surgery, LV end-diastolic pressure increased and coronary driving pressure decreased significantly in the LMI compared with the sham group. LV dP/dt max and dP/dt min of both the SMI and LMI groups were statistically different from those of the sham group. CVF within non-MI interventricular septum and right ventricle did not differ between each MI group and the sham group. Otherwise, subendocardial (SE CVF was statistically greater in the LMI group. SE CVF correlated negatively with post-MI systemic blood pressure and coronary driving pressure, and positively with post-MI LV dP/dt min. Stepwise regression analysis identified post-MI coronary driving pressure as an independent predictor of SE CVF. CONCLUSION: LV remodeling in rats with MI is characterized by predominant SE collagen deposition in non-MI and results from a reduction in myocardial perfusion pressure occurring early on in the setting of MI.

  7. Nitroglycerin-induced heterogeneous subendocardial myocardial blood flow observed by cardioscopy in patients with coronary artery disease.

    Science.gov (United States)

    Uchida, Yasuto; Uchida, Yasumi; Maezawa, Yuko; Maezawa, Yoshiro; Sakurai, Takeshi; Kanai, Masahito; Shirai, Seiichiro; Tabata, Tsuyoshi

    2011-01-01

    It is controversial as to whether or not nitroglycerin (NTG) increases subendocardial myocardial blood flow (SMBF), and if it does, whether arterial or venous blood flow is increased in patients with coronary artery disease. This study was performed to examine NTG-induced changes in SMBF.Changes in SMBF induced by NTG (200 µg, i.v.) were examined by cardioscopy in 58 left ventricular wall segments of 58 patients with coronary artery disease. NTG-induced red and purple endocardial colors were defined as increased arterial and venous SMBF, respectively. Endocardial color before NTG administration was classified into brown, light brown, pale and white. Endomyocardial biopsy of the observed portion and (201)Tl scintigraphy were performed in 40 of these patients immediately after cardioscopy and several days after cardioscopy, respectively.Upon administration of NTG, SMBF increased in 48 of 58 wall segments; arterial SMBF in 34 and venous SMBF in 12 wall segments; arterial SMBF in all 24 brown to light brown segments; venous SMBF, arterial SMBF and no change in 12, 10 and 5 of pale segments, respectively; and no change in all 10 white wall segments. (201)Tl-scintigraphy and endomyocardial biopsy revealed that brown, light brown, pale and white endocardial color represented no ischemia, mild ischemia, severe ischemia and fibrosis, respectively.NTG caused an increase in either arterial or venous SMBF depending on control endocardial color, wall motion and severity of coronary stenosis.

  8. Possible link between strain ST-T change on the electrocardiogram and subendocardial dysfunction assessed by two-dimensional speckle-tracking echocardiography.

    Science.gov (United States)

    Nishikage, Tomoko; Takeuchi, Masaaki; Nakai, Hiromi; Otsuji, Yutaka; Lang, Roberto M

    2010-06-01

    Strain ST-T changes on surface electrocardiogram (ECG) may reflect subendocardial dysfunction. We hypothesized that strain ST-T changes are associated with (i) decrease in longitudinal strain, (ii) decrease in early systolic clockwise twist and early diastolic untwisting, and (iii) augmentation of peak twist due to subendocardial dysfunction. Three levels of left ventricular (LV) short-axis views and three LV apical views were acquired in 46 hypertensive patients with LV hypertrophy and 23 age-matched control subjects using 2D echocardiography. Patients were divided into two groups according to the presence (n = 18) or absence (n = 28) of strain ST-T change on 12-lead ECG. Using 2D strain software, longitudinal, radial, and circumferential strain were measured. Early systolic clockwise twist, end-systolic twist, and untwisting at early diastole were measured from time-domain LV twist curves. No significant intergroup differences in LV ejection fraction were noted. Longitudinal strain was significantly reduced in hypertensive patients with strain ST-T changes compared with those without these changes or control subjects. Although LV twist at end-systole was similar between patients with and without strain ST-T changes, early systolic clockwise twist and untwisting was significantly reduced in strain ST-T change group compared with the no ST-T change group. Multivariate analysis revealed that not LV mass index but strain ST-T change was an independent predictor of global longitudinal strain. The reduction in longitudinal strain, early systolic clockwise twist, and untwisting in hypertensive patients with strain ST-T changes suggests possible link between this ECG abnormality and subendocardial dysfunction, which can be assessed by 2D speckle tracking echocardiography.

  9. Comparison of two- versus three-dimensional myocardial contrast echocardiography for assessing subendocardial perfusion abnormality after percutaneous coronary intervention in patients with acute myocardial infarction.

    Science.gov (United States)

    Iwakura, Katsuomi; Ito, Hiroshi; Okamura, Atsushi; Kurotobi, Toshiya; Koyama, Yasushi; Date, Motoo; Inoue, Koichi; Nagai, Hiroyuki; Imai, Michio; Arita, Yo; Toyoshima, Yuko; Ozawa, Makito; Fujii, Kenshi

    2007-11-15

    Myocardial contrast echocardiography (MCE) visualizes myocardial perfusion abnormalities after acute myocardial infarction. However, the limited view of 2-dimensional echocardiography reduces its ability to estimate perfusion abnormalities, especially in the subendocardial region. Three-dimensional echocardiography provides images of the left ventricular endocardium directly. This study was conducted to evaluate the ability of 3-dimensional MCE to assess abnormalities of subendocardial perfusion. Intracoronary 2- and 3-dimensional MCE was performed after primary percutaneous coronary intervention in 47 patients with acute myocardial infarction. Myocardial perfusion within the risk area was evaluated as good, poor, or no reflow on 2-dimensional MCE or as good, poor, or no myocardial opacification in endocardium on 3-dimensional MCE. The 2 methods showed different distributions of perfusion patterns: good, poor, and no reflow on 2-dimensional MCE in 31 (66%), 9 (19%), and 7 (15%) patients and good, poor, and no myocardial opacification in endocardium on 3-dimensional MCE in 17 (36%), 16 (34%), and 14 (20%) patients, respectively. Although only 19 patients (61%) with good reflow on 2-dimensional MCE showed myocardial perfusion grade 3 on angiography, 16 of 17 patients (94%) with good myocardial opacification in endocardium on 3-dimensional MCE showed myocardial perfusion grade 3. Although there were no significant differences in peak creatine kinase among the 3 subsets classified by 2-dimensional MCE, peak creatine kinase showed significant differences not only among the 3 groups but also among the subsets classified by 3-dimensional MCE. Classification by 3-dimensional MCE also predicted regional wall motion after 4.6 +/- 2.7 months, with significant differences between each pair of groups, whereas there was significant overlap of these values between the group with poor reflow and other 2 groups by 2-dimensional MCE. In conclusion, 3-dimensional MCE is a feasible

  10. Heterogeneous onset of myocardial relaxation in subendocardial and subepicardial layers assessed with tissue strain imaging: comparison of normal and hypertrophied myocardium.

    Science.gov (United States)

    Hasegawa, Takuya; Nakatani, Satoshi; Kanzaki, Hideaki; Abe, Haruhiko; Kitakaze, Masafumi

    2009-06-01

    We sought to investigate the existence of a time difference in myocardial relaxation between the subendocardium and subepicardium in patients with and without myocardial hypertrophy. Regional differences in mechanical and electrical properties between the subendocardium and subepicardium have been described for the left ventricle in animals. However, this difference has not been well evaluated in clinical conditions. Time-to-peak radial strain with reference to the QRS complex was measured at the subendocardium and subepicardium at the mid-posterior wall of the left ventricle in 12 normal subjects, 14 patients with hypertensive heart disease, and 27 patients with aortic stenosis (16 with and 11 without strain electrocardiogram [ECG] pattern) using tissue Doppler-based strain imaging. Time-to-peak radial strain in the subepicardium (381 +/- 60 ms) was shorter than that in the subendocardium (463 +/- 29 ms; p subendocardial relaxation. No significant difference was found between normal subjects and patients with hypertensive heart disease (388 +/- 67 ms for the subepicardium; 455 +/- 36 ms for the subendocardium in hypertensive heart disease). In cases with hypertrophied myocardium due to aortic stenosis, time-to-peak radial strain in the subendocardium was shortened and that in the subepicardium was prolonged. In 10 (63%) of 16 patients with aortic stenosis and strain ECG pattern, the timing of peak strain in the subendocardium (417 +/- 63 ms) preceded that in the subepicardium (452 +/- 62 ms). There is heterogeneous onset of myocardial relaxation in the subendocardial and subepicardial layers at the mid-posterior wall of the left ventricle. Subepicardial myocardial relaxation precedes subendocardial relaxation in normal subjects. In contrast, there is inversion of the transmural sequence of myocardial relaxation between the subendocardium and subepicardium in some patients with aortic stenosis and strain ECG pattern.

  11. The viability of perilabyrinthine osteocytes

    DEFF Research Database (Denmark)

    Bloch, Sune Land; Kristensen, Søren Lund; Sørensen, Mads Sølvsten

    2012-01-01

    Bone remodeling is highly inhibited around the inner ear space, most likely by the anti-resorptive action of the inner ear cytokine osteoprotegerin (OPG) entering perilabyrinthine bone through the lacuno-canalicular porosity (LCP). This extracellular signaling pathway depends on the viability...

  12. A new method of detecting subendocardial ischemia in patients with aortic valvular stenosis without coronary artery disease using thallium-201 single photon emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Umamoto, Ikuo; Sugihara, Hiroki; Harada, Yoshiaki (Kyoto Prefectural Univ. of Medicine (Japan)) (and others)

    1993-02-01

    The purpose of this study was to detect myocardial ischemia in aortic valvular stenosis (AVS) without coronary artery disease by using exercise Tl-201 SPECT. The subjects were 18 AVS patients. Twenty other patients were served as controls. Transient 'left ventricular subendocardial dilation and decreased wall thickness', obtained on early SPECT images, were quantitatively determined by transient dilation index (TDI). Washout rates (WR) were calculated from overlapping early and delayed images to obtain WR map. According to TDI, 18 AVS patients were classified as having TDI[<=]1.11 (Group A, n=9) and TDI>1.11 (Group B, n=9). WR map in Group B presented the direction from the pericardial toward the endocardial side, revealing a pattern of decreased WR and a decreased coronary flow reserve on the endocardial side. Both pressure gradient between the aorta and left ventricle and left ventricular wall thickness were significantly greater in Group B than Group A. In 3 patients in Group B, TDI returned to normal and WR map became homogeneous after aortic valve replacement. In addition, fibrosis was noted in the endocardial site on biopsy. In AVS associated with great pressure gradient, endocardial ischemia may occur on exercise, resulting from a decreased coronary flow reserve, and a decreased compliance due to fibrosis and hypertrophy. Exercise Tl-201 myocardial SPECT is capable of detecting distribution patterns of subendocardial ischemia and coronary flow reserve in AVS. (N.K.).

  13. Concentric hypertrophic remodelling and subendocardial dysfunction in mitochondrial DNA point mutation carriers.

    Science.gov (United States)

    Bates, Matthew G D; Hollingsworth, Kieren G; Newman, Jane H; Jakovljevic, Djordje G; Blamire, Andrew M; MacGowan, Guy A; Keavney, Bernard D; Chinnery, Patrick F; Turnbull, Douglass M; Taylor, Robert W; Trenell, Michael I; Gorman, Grainne S

    2013-07-01

    Hypertrophic remodelling and systolic dysfunction are common in patients with mitochondrial disease and independent predictors of morbidity and early mortality. Screening strategies for cardiac disease are unclear. We investigated whether myocardial abnormalities could be identified in mitochondrial DNA mutation carriers without clinical cardiac involvement. Cardiac magnetic resonance imaging was performed in 22 adult patients with mitochondrial disease due to the m.3243A>G mutation, but no known cardiac involvement, and 22 age- and gender-matched control subjects: (i) Phosphorus-31- magnetic resonance spectroscopy, (ii) cine imaging (iii), cardiac tagging and (iv) late gadolinium enhancement (LGE) imaging. Disease burden was determined using the Newcastle Mitochondrial Disease Adult Scale (NMDAS) and urinary mutation load. Compared with control subjects, patients had an increased left ventricular mass index (LVMI), LV mass to end-diastolic volume (M/V) ratio, wall thicknesses (all P mutation load and NMDAS correlated with the LVMI (r = 0.71 and r = 0.79, respectively, both P G mutation without clinical cardiac disease. Patients with higher mutation loads and disease burden may be at increased risk of cardiac involvement.

  14. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  15. Golden Ratio

    Indian Academy of Sciences (India)

    Our attraction to another body increases if the body is sym- metrical and in proportion. If a face or a structure is in pro- portion, we are more likely to notice it and find it beautiful. The universal ratio of beauty is the 'Golden Ratio', found in many structures. This ratio comes from Fibonacci numbers. In this article, we explore this ...

  16. Golden Ratio

    Indian Academy of Sciences (India)

    Our attraction to another body increases if the body is symmetricaland in proportion. If a face or a structure is in proportion,we are more likely to notice it and find it beautiful.The universal ratio of beauty is the 'Golden Ratio', found inmany structures. This ratio comes from Fibonacci numbers.In this article, we explore this ...

  17. Tychastic measure of viability risk

    CERN Document Server

    Aubin, Jean-Pierre; Dordan, Olivier

    2014-01-01

    This book presents a forecasting mechanism of the price intervals for deriving the SCR (solvency capital requirement) eradicating the risk during the exercise period on one hand, and measuring the risk by computing the hedging exit time function associating with smaller investments the date until which the value of the portfolio hedges the liabilities on the other. This information, summarized under the term “tychastic viability measure of risk” is an evolutionary alternative to statistical measures, when dealing with evolutions under uncertainty. The book is written by experts in the field and the target audience primarily comprises research experts and practitioners.

  18. Isolation and characterization of CD276+/HLA-E+ human subendocardial mesenchymal stem cells from chronic heart failure patients: analysis of differentiative potential and immunomodulatory markers expression.

    Science.gov (United States)

    Anzalone, Rita; Corrao, Simona; Lo Iacono, Melania; Loria, Tiziana; Corsello, Tiziana; Cappello, Francesco; Di Stefano, Antonino; Giannuzzi, Pantaleo; Zummo, Giovanni; Farina, Felicia; La Rocca, Giampiero

    2013-01-01

    Mesenchymal stem cells (MSCs) are virtually present in all postnatal organs as well as in perinatal tissues. MSCs can be differentiated toward several mature cytotypes and interestingly hold potentially relevant immunomodulatory features. Myocardial infarction results in severe tissue damage, cardiomyocyte loss, and eventually heart failure. Cellular cardiomyoplasty represents a promising approach for myocardial repair. Clinical trials using MSCs are underway for a number of heart diseases, even if their outcomes are hampered by low long-term improvements and the possible presence of complications related to cellular therapy administration. Therefore, elucidating the presence and role of MSCs that reside in the post-infarct human heart should provide essential alternatives for therapy. In the current article we show a novel method to reproducibly isolate and culture MSCs from the subendocardial zone of human left ventricle from patients undergoing heart transplant for post-infarct chronic heart failure (HSE-MSCs, human subendocardial mesenchymal stem cells). By using both immunocytochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR), we demonstrated that these cells do express key MSCs markers and do express heart-specific transcription factors in their undifferentiated state, while lacking strictly cardiomyocyte-specific proteins. Moreover, these cells do express immunomodulatory molecules that should disclose their further potential in immune modulation processes in the post-infarct microenvironment. Another novel datum of potentially relevant interest is the expression of cardiac myosin heavy chain at nucclear level in HSE-MSCs. Standard MSCs trilineage differentiation experiments were also performed. The present paper adds new data on the basic biological features of heart-resident MSCs that populate the organ following myocardial infarction. The use of heart-derived MSCs to promote in-organ repair or as a cellular source for cardiomyoplasty

  19. Wildlife Tunnel Enhances Population Viability

    Directory of Open Access Journals (Sweden)

    Rodney van der Ree

    2009-12-01

    Full Text Available Roads and traffic are pervasive components of landscapes throughout the world: they cause wildlife mortality, disrupt animal movements, and increase the risk of extinction. Expensive engineering solutions, such as overpasses and tunnels, are increasingly being adopted to mitigate these effects. Although some species readily use such structures, their success in preventing population extinction remains unknown. Here, we use population viability modeling to assess the effectiveness of tunnels for the endangered Mountain Pygmy-possum (Burramys parvus in Australia. The underpasses reduced, but did not completely remove, the negative effects of a road. The expected minimum population size of a "reconnected" population remained 15% lower than that of a comparable "undivided" population. We propose that the extent to which the risk of extinction decreases should be adopted as a measure of effectiveness of mitigation measures and that the use of population modeling become routine in these evaluations.

  20. Malthus, Boserup and population viability.

    Science.gov (United States)

    Bonneuil, N

    1994-01-01

    The Malthus-Boserup explanatory framework is revisited from the point of view of viability theory. Instead of imposing a univocal relationship between population pressure and level of knowledge, the way technology will change is not determined, it is only constrained. This leads to regard any situation as associated to a set of reachable futures. When no possibility is left for systems to avoid extinction, systems are no longer viable. Hence, the control-phase space can be divided into regions corresponding to gradual danger or security. This point of view allows the introduction of ideas such as incentives to create or to use new knowledge, gives a role to the threatening power of Malthusian checks, and leaves space for a specific variety of behaviors. The Boserupian theme then appears indirectly, emerging from the constraints imposed by the inertia of technological change.

  1. Viability of telework at PROCEMPA.

    Science.gov (United States)

    Fetzner, Maria Amelia de Mesquita

    2003-02-01

    At the end of the 20th century, telework appears as one of the modalities of flexible work, which is related to new organizational structures as well as to increasing use of technology. It revolutionizes the traditional ways of performing work. Its implementation creates a number of questions to be answered by the organizations and the individuals involved. This article presents a case study on the viability of implementing telework at Procempa (The Data Processing Company of the City of Porto Alegre). The case study analyzes the technical, organizational, psychological, legal, and labor union dimensions. As a result of this study, we can identify the organization's stage of readiness for telework, the conditions under which it would be implemented, and the specific issues of an implementation.

  2. Economic viability of anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Wellinger, A. [INFOENERGIE, Ettenhausen (Switzerland)

    1996-01-01

    The industrial application of anaerobic digestion is a relatively new, yet proven waste treatment technology. Anaerobic digestion reduces and upgrades organic waste, and is a good way to control air pollution as it reduces methane and nitrous gas emissions. For environmental and energy considerations, anaerobic digestion is a nearly perfect waste treatment process. However, its economic viability is still in question. A number of parameters - type of waste (solid or liquid), digester system, facility size, product quality and end use, environmental requirements, cost of alternative treatments (including labor), and interest rates - define the investment and operating costs of an anaerobic digestion facility. Therefore, identical facilities that treat the same amount and type of waste may, depending on location, legislation, and end product characteristics, reveal radically different costs. A good approach for evaluating the economics of anaerobic digestion is to compare it to treatment techniques such as aeration or conventional sewage treatment (for industrial wastewater), or composting and incineration (for solid organic waste). For example, the cost (per ton of waste) of in-vessel composting with biofilters is somewhat higher than that of anaerobic digestion, but the investment costs 1 1/2 to 2 times more than either composting or anaerobic digestion. Two distinct advantages of anaerobic digestion are: (1) it requires less land than either composting or incinerating, which translates into lower costs and milder environmental and community impacts (especially in densely populated areas); and (2) it produces net energy, which can be used to operate the facility or sold to nearby industries.

  3. Does the balanced scorecard support organizational viability?

    NARCIS (Netherlands)

    Achterbergh, J.M.I.M.; Beeres, R.J.M.; Vriens, D.J.

    2003-01-01

    In this paper we assess whether the balanced scorecard (BSC) supports the necessary functions for organizational viability. To this purpose, we use the viable system model (VSM) as a means to describe the functions required for organizational viability. Then we use the VSM as a template to assess

  4. Pollen viability and membrane lipid composition

    NARCIS (Netherlands)

    Bilsen, van D.G.J.L.

    1993-01-01

    In this thesis membrane lipid composition is studied in relation to pollen viability during storage. Chapter 1 reviews pollen viability, membranes in the dry state and membrane changes associated with cellular aging. This chapter is followed by a study of age-related changes in phospholipid

  5. The Effects of Diabetes Induction on the Rat Heart: Differences in Oxidative Stress, Inflammatory Cells, and Fibrosis between Subendocardial and Interstitial Myocardial Areas.

    Science.gov (United States)

    Guido, Maria C; Marques, Alyne F; Tavares, Elaine R; Tavares de Melo, Marcelo D; Salemi, Vera M C; Maranhão, Raul C

    2017-01-01

    Diabetic cardiomyopathy (DCM) is characterized by cardiac remodeling and impaired diastolic function that may lead to heart failure. The aim of this study was to evaluate oxidative stress, inflammatory cells, and fibrosis in both subendocardial (SEN) and interstitial (INT) areas of the myocardium. Male Wistar rats were allocated to 2 groups of 9 animals, a control (CT) group and streptozotocin-induced diabetes (DM). After 8 weeks, echocardiography morphometry, protein expression, and confocal microscopy in SEN and INT areas of the left ventricle (LV) were performed. The echocardiographic analysis showed that diabetes induction leads to cardiac dilation, hypertrophy, and LV diastolic dysfunction. As compared to CT, the induction of diabetes increased inflammatory cells and fibrosis in both SEN and INT areas of DM myocardium and increased ROS generation only in SEN. Comparing the SEN and INT areas in the DM group, inflammatory cells and fibrosis in SEN were greater than in INT. In conclusion, diabetic myocardium SEN area, wherein oxidative stress was more pronounced, is more susceptible to cardiac dysfunction than INT area. This finding can be important for the understanding of the heart remodeling process occurring in DCM and perhaps to engender targeted therapies to attenuate or revert DCM-related diastolic dysfunction.

  6. The Effects of Diabetes Induction on the Rat Heart: Differences in Oxidative Stress, Inflammatory Cells, and Fibrosis between Subendocardial and Interstitial Myocardial Areas

    Directory of Open Access Journals (Sweden)

    Maria C. Guido

    2017-01-01

    Full Text Available Diabetic cardiomyopathy (DCM is characterized by cardiac remodeling and impaired diastolic function that may lead to heart failure. The aim of this study was to evaluate oxidative stress, inflammatory cells, and fibrosis in both subendocardial (SEN and interstitial (INT areas of the myocardium. Male Wistar rats were allocated to 2 groups of 9 animals, a control (CT group and streptozotocin-induced diabetes (DM. After 8 weeks, echocardiography morphometry, protein expression, and confocal microscopy in SEN and INT areas of the left ventricle (LV were performed. The echocardiographic analysis showed that diabetes induction leads to cardiac dilation, hypertrophy, and LV diastolic dysfunction. As compared to CT, the induction of diabetes increased inflammatory cells and fibrosis in both SEN and INT areas of DM myocardium and increased ROS generation only in SEN. Comparing the SEN and INT areas in the DM group, inflammatory cells and fibrosis in SEN were greater than in INT. In conclusion, diabetic myocardium SEN area, wherein oxidative stress was more pronounced, is more susceptible to cardiac dysfunction than INT area. This finding can be important for the understanding of the heart remodeling process occurring in DCM and perhaps to engender targeted therapies to attenuate or revert DCM-related diastolic dysfunction.

  7. Terminology for pregnancy loss prior to viability

    DEFF Research Database (Denmark)

    Kolte, A M; Bernardi, L A; Christiansen, O B

    2015-01-01

    Pregnancy loss prior to viability is common and research in the field is extensive. Unfortunately, terminology in the literature is inconsistent. The lack of consensus regarding nomenclature and classification of pregnancy loss prior to viability makes it difficult to compare study results from...... different centres. In our opinion, terminology and definitions should be based on clinical findings, and when possible, transvaginal ultrasound. With this Early Pregnancy Consensus Statement, it is our goal to provide clear and consistent terminology for pregnancy loss prior to viability....

  8. Near viability for fully nonlinear differential inclusions

    National Research Council Canada - National Science Library

    Irina Căpraru; Alina Lazu

    2014-01-01

    .... We establish a viability result under Lipschitz hypothesis on F, that consists in proving the existence of solutions of the differential inclusion above, starting from a given set, which remain...

  9. Poxvirus viability and signatures in historical relics

    National Research Council Canada - National Science Library

    McCollum, Andrea M; Li, Yu; Wilkins, Kimberly; Karem, Kevin L; Davidson, Whitni B; Paddock, Christopher D; Reynolds, Mary G; Damon, Inger K

    2014-01-01

    Although it has been >30 years since the eradication of smallpox, the unearthing of well-preserved tissue material in which the virus may reside has called into question the viability of variola virus decades or centuries...

  10. Intraspecific variation in pollen viability, germination and ...

    African Journals Online (AJOL)

    Oleaceae) cultivars 'Koroneiki', 'Mastoidis' and 'Kalamata' was studied with scanning electron microscopy to identify genotype- distinguishing characters that could be employed for morphological cultivar discrimination. Pollen viability and germination ...

  11. Probiotic viability – does it matter?

    OpenAIRE

    Sampo J. Lahtinen

    2012-01-01

    Probiotics are viable by definition, and viability of probiotics is often considered to be a prerequisite for the health benefits. Indeed, the overwhelming majority of clinical studies in the field have been performed with viable probiotics. However, it has also been speculated that some of the mechanisms behind the probiotic health effects may not be dependent on the viability of the cells, and therefore is also possible that also nonviable probiotics could have some health benefits. The eff...

  12. The clinical significance of the atrial subendocardial smooth muscle layer and cardiac myofibroblasts in human atrial tissue with valvular atrial fibrillation.

    Science.gov (United States)

    Park, Jae Hyung; Pak, Hui-Nam; Lee, Sak; Park, Han Ki; Seo, Jeong-Wook; Chang, Byung-Chul

    2013-01-01

    The existence of myofibroblasts (MFBs) and the role of subendocardial smooth muscle (SSM) layer of human atrial tissue in atrial fibrillation (AF) have not yet been elucidated. We hypothesized that the SSM layer and MFB play some roles in atrial structural remodeling and maintenance of valvular AF in patients who undergo cardiac surgery. We analyzed immunohistochemical staining of left atrial (LA) appendage tissues taken from 17 patients with AF and 15 patients remaining in sinus rhythm (SR) who underwent cardiac surgery (male 50.0%, 54.1 ± 14.2 years old, valve surgery 87.5%). SSM was quantified by α-smooth muscle actin (α-SMA) stain excluding vascular structure. MFB was defined as α-SMA+ cells with disorganized Connexin 43-positive gap junctions in Sirius red-positive fibrotic area. The SSM layer of atrium was significantly thicker in patients with AF than in those with SR (P=.0091). Patients with SSM layer ≥ 14 μm had a larger LA size (P=.0006) and greater fibrotic area (P=.0094) than those patients whose SSM layer <14 μm. MFBs were found in 7 of 17 (41.2%) patients with AF and 2 of 15 (13.3%) in SR group (P=.0456) in SSM area, colocalized with Periodic Acid-Schiff (PAS) stain-positive glycogen storage cells (95.5%). SSM layer was closely related to the existence of AF, degrees of atrial remodeling, and fibrosis in patients who underwent open heart surgery. We found that MFB does exist in SSM layer of human atrial tissue co-localized with PAS-positive cells. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  13. Viability analysis in biological evaluations: Concepts of population viability analysis, biological population, and ecological scale

    Science.gov (United States)

    Gregory D. Hayward; John R. Squires

    1994-01-01

    Environmental protection strategies often rely on environmental impact assessments. As part of the assessment process biologists are routinely asked to evaluate the effects of management actions on plants and animals. This evaluation often requires that biologists make judgments about the viability of affected populations. However, population viability...

  14. Effect of air drying on bacterial viability: A multiparameter viability assessment

    NARCIS (Netherlands)

    Nocker, A.; Fernández, P.S.; Montijn, R.; Schuren, F.

    2012-01-01

    The effect of desiccation on the viability of microorganisms is a question of great interest for a variety of public health questions and industrial applications. Although viability is traditionally assessed by plate counts, cultivation-independent methods are increasingly applied with the aim to

  15. Viability and Resilience of Languages in Competition

    Science.gov (United States)

    Chapel, Laetitia; Castelló, Xavier; Bernard, Claire; Deffuant, Guillaume; Eguíluz, Víctor M.; Martin, Sophie; Miguel, Maxi San

    2010-01-01

    We study the viability and resilience of languages, using a simple dynamical model of two languages in competition. Assuming that public action can modify the prestige of a language in order to avoid language extinction, we analyze two cases: (i) the prestige can only take two values, (ii) it can take any value but its change at each time step is bounded. In both cases, we determine the viability kernel, that is, the set of states for which there exists an action policy maintaining the coexistence of the two languages, and we define such policies. We also study the resilience of the languages and identify configurations from where the system can return to the viability kernel (finite resilience), or where one of the languages is lead to disappear (zero resilience). Within our current framework, the maintenance of a bilingual society is shown to be possible by introducing the prestige of a language as a control variable. PMID:20126655

  16. Probiotic viability – does it matter?

    Directory of Open Access Journals (Sweden)

    Sampo J. Lahtinen

    2012-06-01

    Full Text Available Probiotics are viable by definition, and viability of probiotics is often considered to be a prerequisite for the health benefits. Indeed, the overwhelming majority of clinical studies in the field have been performed with viable probiotics. However, it has also been speculated that some of the mechanisms behind the probiotic health effects may not be dependent on the viability of the cells and, therefore, is also possible that also non-viable probiotics could have some health benefits. The efficacy of non-viable probiotics has been assessed in a limited number of studies, with varying success. While it is clear that viable probiotics are more effective than non-viable probiotics and that, in many cases, viability is indeed a prerequisite for the health benefit, there are also some cases where it appears that non-viable probiotics could also have beneficial effects on human health.

  17. Economic Viability and Marketing Strategies of Periwinkle ...

    African Journals Online (AJOL)

    The economic viability and marketing strategies of periwinkle species in twelve major markets across Rivers State Nigeria were investigated using structured questionnaires. The results indicated that marketing strategies are enroute, through harvesters (collectors), to wholesalers (those who purchase in small quantities ...

  18. Extending the viability of sea urchin gametes.

    Science.gov (United States)

    Spiegler, M A; Oppenheimer, S B

    1995-04-01

    The sea urchin is the material of choice for studying many early developmental events. Methods to extend the viability of sea urchin gametes have not received much attention, but it is well known that the eggs are easily damaged by freezing. This study was designed to extend the viability of Lytechinus pictus eggs and sperm without freezing. Gamete viability measurements were based on relative numbers of fertilized vs unfertilized eggs, percentage fertilization, and on observations of embryonic development. Results indicate that gametes can be stored longer and at lower temperatures than previously described. Sperm were consistently kept viable for at least 12 days with little decrease in viability when stored in glass test tubes or plastic petri dishes and submerged in ice inside a refrigerator at 0 +/- 1 degree C. In one experiment, sperm stored in glass test tubes on ice remained viable up to 20 days after extraction. Eggs were maintained from 1 to 7 days, rather than the 1 day or so previously reported, when stored in glass test tubes submerged in ice in a refrigerator at 0 +/- 1 degree C. Results of egg and sperm experiments varied at different times in the season. Such variations may be caused by seasonal cytoplasmic changes, population differences, or the time mature individuals were maintained unfed in aquaria prior to use. Results from this study should be useful for a variety of research, mariculture, and teaching applications in which sea urchin supplies are limited or when the same gamete population is required for subsequent experiments.

  19. Incorporating evolutionary processes into population viability models

    NARCIS (Netherlands)

    Pierson, J.C.; Beissinger, S.R.; Bragg, J.G.; Coates, D.J.; Oostermeijer, J.G.B.; Sunnucks, P.; Schumaker, N.H.; Trotter, M.V.; Young, A.G.

    2015-01-01

    We examined how ecological and evolutionary (eco-evo) processes in population dynamics could be better integrated into population viability analysis (PVA). Complementary advances in computation and population genomics can be combined into an eco-evo PVA to offer powerful new approaches to understand

  20. Assessment of myocardial viability using PET

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Seok Nam [College of Medicine, Ajou University, Suwon (Korea, Republic of)

    2005-02-15

    The potential for recovery of left ventricular dysfunction after myocardial revascularization represents a practical clinical definition for myocardial viability. The evaluation of viable myocardium in patients with severe global left ventricular dysfunction due to coronary artery disease and with regional dysfunction after acute myocardial infarction is an important issue whether left ventricular dysfunction may be reversible or irreversible after therapy. If the dysfunction is due to stunning or hibernation, functional improvement is observed. But stunned myocardium may recover of dysfunction with no revascularization. Hibernation is chronic process due to chronic reduction in the resting myocardial blood flow. There are two types of myocardial hibernation; 'functional hibernation' with preserved contractile reserve and 'structural hibernation' without contractile reserve in segments with preserved glucose metabolism. This review focus on the application of F-18 FDG and other radionuclides to evaluate myocardial viability. In addition the factors influencing predictive value of FDG imaging for evaluating viability and the different criteria for viability are also reviewed.

  1. Viability of mesenchymal stem cells during electrospinning

    Directory of Open Access Journals (Sweden)

    G. Zanatta

    2012-02-01

    Full Text Available Tissue engineering is a technique by which a live tissue can be re-constructed and one of its main goals is to associate cells with biomaterials. Electrospinning is a technique that facilitates the production of nanofibers and is commonly used to develop fibrous scaffolds to be used in tissue engineering. In the present study, a different approach for cell incorporation into fibrous scaffolds was tested. Mesenchymal stem cells were extracted from the wall of the umbilical cord and mononuclear cells from umbilical cord blood. Cells were re-suspended in a 10% polyvinyl alcohol solution and subjected to electrospinning for 30 min under a voltage of 21 kV. Cell viability was assessed before and after the procedure by exclusion of dead cells using trypan blue staining. Fiber diameter was observed by scanning electron microscopy and the presence of cells within the scaffolds was analyzed by confocal laser scanning microscopy. After electrospinning, the viability of mesenchymal stem cells was reduced from 88 to 19.6% and the viability of mononuclear cells from 99 to 8.38%. The loss of viability was possibly due to the high viscosity of the polymer solution, which reduced the access to nutrients associated with electric and mechanical stress during electrospinning. These results suggest that the incorporation of cells during fiber formation by electrospinning is a viable process that needs more investigation in order to find ways to protect cells from damage.

  2. Pollen viability in Quercus robur L.

    Directory of Open Access Journals (Sweden)

    Batos Branislava

    2017-01-01

    Full Text Available The variability of viability (germination rate and the length of pollen tubes of fresh pedunculate oak (Quercus robur L. pollen grains was studied in vitro on a medium containing 15% sucrose. Spatial variability was studied by sampling fresh pollen grains from a total of thirteen trees at four different sites in the area of Belgrade (Košutnjak, Banovo Brdo, Ada Ciganlija and Bojčin Forest in a single year (2011. In order to assess temporal variability and determine the effects of climate change on a small time scale, we studied the viability of the pollen grains collected from one tree at the Banovo Brdo site in six different years (2004, 2005, 2006, 2007, 2011 and 2012. Interindividual variability was tested on the pollen grains sampled from eight trees at Ada Ciganlija in 2004. The percentage values of the pollen grain germination rate and the pollen tube length showed no statistically significant differences between the sites. However, the studied characteristics of the pollen grain viability (germination rate and pollen tube length showed statistically significant differences in both temporal (between the pollen collection years and interindividual variability. This type of research makes a valuable contribution to pedunculate oak breeding programs through the identification of trees with stable production and a good quality of pollen. Furthermore, it can be important in defining the patterns of spatial, temporal and individual variability of pollen grain viability under the influence of climate factors, which are showing compelling changing trends from year to year.

  3. Activin Receptor Signaling Regulates Prostatic Epithelial Cell Adhesion and Viability

    Directory of Open Access Journals (Sweden)

    Derek P. Simon

    2009-04-01

    Full Text Available Mutational changes coupled with endocrine, paracrine, and/or autocrine signals regulate cell division during carcinogenesis. The hormone signals remain undefined, although the absolute requirement in vitro for fetal serum indicates the necessity for a fetal serum factor(s in cell proliferation. Using prostatic cancer cell (PCC lines as a model of cancer cell proliferation, we have identified the fetal serum component activin A and its signaling through the activin receptor type II (ActRII, as necessary, although not sufficient, for PCC proliferation. Activin A induced Smad2 phosphorylation and PCC proliferation, but only in the presence of fetal bovine serum (FBS. Conversely, activin A antibodies and inhibin A suppressed FBS-induced PCC proliferation confirming activin A as one of multiple serum components required for PCC proliferation. Basic fibroblast growth factor was subsequently shown to synergize activin A-induced PCC proliferation. Inhibition of ActRII signaling using a blocking antibody or antisense-P decreased mature ActRII expression, Smad2 phosphorylation, and the apparent viability of PCCs and neuroblastoma cells grown in FBS. Suppression of ActRII signaling in PCC and neuroblastoma cells did not induce apoptosis as indicated by the ratio of active/inactive caspase 3 but did correlate with increased cell detachment and ADAM-15 expression, a disintegrin whose expression is strongly correlated with prostatic metastasis. These findings indicate that ActRII signaling is required for PCC and neuroblastoma cell viability, with ActRII mediating cell fate via the regulation of cell adhesion. That ActRII signaling governs both cell viability and cell adhesion has important implications for developing therapeutic strategies to regulate cancer growth and metastasis.

  4. Monitoring cell growth, viability, and apoptosis.

    Science.gov (United States)

    Butler, Michael; Spearman, Maureen; Braasch, Katrin

    2014-01-01

    The accurate determination of cell growth and viability is pivotal to monitoring a bioprocess. Direct methods to determine the cell growth and/or viability in a bioprocess include microscopic counting, electronic particle counting, image analysis, in situ biomass monitoring, and dieletrophoretic cytometry. These methods work most simply when a fixed volume sample can be taken from a suspension culture. Manual microscopic counting is laborious but affords the advantage of allowing cell viability to be determined if a suitable dye is included. Electronic particle counting is a rapid total cell count method for replicate samples, but some data distortion may occur if the sample has significant cell debris or cell aggregates. Image analysis based on the use of digital camera images acquired through a microscope has advanced rapidly with the availability of several commercially available software packages replacing manual microscopic counting and viability determination. Biomass probes detect cells by their dielectric properties or their internal concentration of NADH and can be used as a continuous monitor of the progress of a culture. While the monitoring of cell growth and viability is an integral part of a bioprocess, the monitoring of apoptosis induction is also becoming more and more important in bioprocess control to increase volumetric productivity by extending bioprocess duration. Different fluorescent assays allow for the detection of apoptotic characteristics in a cell sample.Indirect methods of cell determination involve the chemical analysis of a culture component or a measure of metabolic activity. These methods are most useful when it is difficult to obtain intact cell samples. However, the relationship between these parameters and the cell number may not be linear through the phases of a cell culture. The determination of nucleic acid (DNA) or total protein can be used as an estimate of biomass, while the depletion of glucose from the media can be used

  5. No. 347-Obstetric Management at Borderline Viability.

    Science.gov (United States)

    Ladhani, Noor Niyar N; Chari, Radha S; Dunn, Michael S; Jones, Griffith; Shah, Prakesh; Barrett, Jon F R

    2017-09-01

    The primary objective of this guideline was to develop consensus statements to guide clinical practice and recommendations for obstetric management of a pregnancy at borderline viability, currently defined as prior to 25+6 weeks. Clinicians involved in the obstetric management of women whose fetus is at the borderline of viability. Women presenting for possible birth at borderline viability. This document presents a summary of the literature and a general consensus on the management of pregnancies at borderline viability, including maternal transfer and consultation, administration of antenatal corticosteroids and magnesium sulfate, fetal heart rate monitoring, and considerations in mode of delivery. Medline, EMBASE, and Cochrane databases were searched using the following keywords: extreme prematurity, borderline viability, preterm, pregnancy, antenatal corticosteroids, mode of delivery. The results were then studied, and relevant articles were reviewed. The references of the reviewed studies were also searched, as were documents citing pertinent studies. The evidence was then presented at a consensus meeting, and statements were developed. The content and recommendations were developed by the consensus group from the fields of Maternal-Fetal Medicine, Neonatology, Perinatal Nursing, Patient Advocacy, and Ethics. The quality of evidence was rated using criteria described in the Grading of Recommendations Assessment, Development and Evaluation methodology framework (reference 1). The Board of the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations, Assessment, Development, and Evaluation methodology framework. The interpretation of strong and weak recommendations is described later. The Summary of Findings is available upon request. A multidisciplinary approach should be used in counselling women and families at borderline

  6. Viability of encapsulated Lactobacillus sp. Mar 8

    Directory of Open Access Journals (Sweden)

    EVI TRIANA

    2006-04-01

    Full Text Available Lactobacillus sp. Mar 8 had advantages as probiotic digestive system cholesterol lowering Lactobacillus. Applying in industry, particular processing technique is necessary for gaining product that ready for marketing and consuming. Spray drying is common technique using in various food processing. High processing temperature, 100-200oC, for 3-10 second become the barrier because cells were under extreme temperature stress. Therefore, encapsulate was needed to protect the cells from those extreme conditions. Viability and survival rate of encapsulated Lactobacillus sp. Mar 8 have been investigated. The result showed that Lactobacillus sp. Mar 8 that was encapsulated by 10% skim milk has higher viability than those by 5% skim milk, namely 72.37% and 51.69% respectively. Survival rate of encapsulated Lactobacillus cells will come to zero in 41.28 years. Therefore, encapsulated Lactobacillus sp. Mar 8 may use as probiotic agent.

  7. Rapid onsite assessment of spore viability.

    Energy Technology Data Exchange (ETDEWEB)

    Branda, Steven; Lane, Todd W.; VanderNoot, Victoria A.; Gaucher, Sara P.; Jokerst, Amanda S.

    2005-12-01

    This one year LDRD addresses problems of threat assessment and restoration of facilities following a bioterror incident like the incident that closed down mail facilities in late 2001. Facilities that are contaminated with pathogenic spores such as B. anthracis spores must be shut down while they are treated with a sporicidal agent and the effectiveness of the treatment is ascertained. This process involves measuring the viability of spore test strips, laid out in a grid throughout the facility; the CDC accepted methodologies require transporting the samples to a laboratory and carrying out a 48 hr outgrowth experiment. We proposed developing a technique that will ultimately lead to a fieldable microfluidic device that can rapidly assess (ideally less than 30 min) spore viability and effectiveness of sporicidal treatment, returning facilities to use in hours not days. The proposed method will determine viability of spores by detecting early protein synthesis after chemical germination. During this year, we established the feasibility of this approach and gathered preliminary results that should fuel a future more comprehensive effort. Such a proposal is currently under review with the NIH. Proteomic signatures of Bacillus spores and vegetative cells were assessed by both slab gel electrophoresis as well as microchip based gel electrophoresis employing sensitive laser-induced fluorescence detection. The conditions for germination using a number of chemical germinants were evaluated and optimized and the time course of protein synthesis was ascertained. Microseparations were carried out using both viable spores and spores inactivated by two different methods. A select number of the early synthesis proteins were digested into peptides for analysis by mass spectrometry.

  8. Viability of pollen grains of tetraploid banana

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares

    2016-01-01

    Full Text Available ABSTRACT Obtaining banana tetraploid cultivars from triploid strains results in total or partial reestablishment of fertility, allowing the occurrence of some fruits with seeds, a feature that is undesirable from a marketing perspective. The objective of this study was to assess the viability of pollen of 12 banana tetraploid hybrids (AAAB by means of in vitro germination and two histochemical tests (acetocarmine and 2,3,5-triphenyltetrazolium chloride. The pollen tube growth was evaluated by germinating grains in three culture media — M1: 0.03% Ca(NO3∙4H2O, 0.02% Mg(SO4∙7H2O, 0.01% KNO3, 0.01% H3BO3 and 15% sucrose; M2: 0.03% Ca(NO3∙4H2O, 0.01% KNO3, 0.01% H3BO3 and 10% sucrose; and M3: 0.015% H3BO3, 0.045% Ca3(PO42 and 25% sucrose. The acetocarmine staining indicated high viability (above 80%, except for the genotypes YB42-17 and Caprichosa, which were 76 and 70%, respectively. However, the in vitro germination rate was lower than 50% for all the genotypes, except for the hybrids YB42-17 (M1 and YB42-47 (M1. The medium M1 provided the greatest germination percentage and pollen tube growth. Among the genotypes assessed, YB42-47 presented the highest germination rate (61.5% and tube length (5.0 mm. On the other hand, the Vitória cultivar had the lowest germination percentage (8.2% in medium M1. Studies of meiosis can shed more light on the differences observed in the evaluated tetraploids, since meiotic irregularities can affect pollen viability.

  9. Serial hCG and progesterone levels to predict early pregnancy outcomes in pregnancies of uncertain viability: A prospective study.

    Science.gov (United States)

    Puget, Claire; Joueidi, Yolaine; Bauville, Estelle; Laviolle, Bruno; Bendavid, Claude; Lavoué, Vincent; Le Lous, Maela

    2018-01-01

    To assess the value of serial hCG and progesterone serum level in the diagnosis of early pregnancy viability. It was a prospective cohort study. Women with a pregnancy of uncertain viability (PUV), defined as the presence of an intra-uterine embryo with a crown-rump length hCG levels on the first day and 48h after as well as the initial progesterone level were evaluated to diagnose pregnancy viability. Pregnancy viability was assessed by TVS 7 to 14days after inclusion. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an hCG H48/H0 ratio increase hCG H48/H0 ratio increase >75% to diagnose a viable pregnancy were 100%, 31%, 45.9% and 100%, respectively. hCG H48/H0 ratio increase hCG H48/H0 ratio increase >75% was associated with 100% of viable pregnancies in 100% of the cases. Serial hCG levels alone permitted an early viability diagnosis within 48h for 41.1% of patients with PUV instead of 7 to 14days with TVS. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Population Viability Analysis of Riverine Fishes

    Energy Technology Data Exchange (ETDEWEB)

    Bates, P.; Chandler, J.; Jager, H.I.; Lepla, K.; Van Winkle, W.

    1999-04-12

    Many utilities face conflkts between two goals: cost-efficient hydropower generation and protecting riverine fishes. Research to develop ecological simulation tools that can evaluate alternative mitigation strategies in terms of their benefits to fish populations is vital to informed decision-making. In this paper, we describe our approach to population viability analysis of riverine fishes in general and Snake River white sturgeon in particular. We are finding that the individual-based modeling approach used in previous in-stream flow applications is well suited to addressing questions about the viability of species of concern for several reasons. Chief among these are: (1) the abiIity to represent the effects of individual variation in life history characteristics on predicted population viabili~, (2) the flexibili~ needed to quanti~ the ecological benefits of alternative flow management options by representing spatial and temporal variation in flow and temperaturty and (3) the flexibility needed to quantifi the ecological benefits of non-flow related manipulations (i.e., passage, screening and hatchery supplementation).

  11. Cytotoxicity and Effects on Cell Viability of Nickel Nanowires

    KAUST Repository

    Rodriguez, Jose E.

    2013-05-01

    Recently, magnetic nanoparticles are finding an increased use in biomedical applications and research. Nanobeads are widely used for cell separation, biosensing and cancer therapy, among others. Due to their properties, nanowires (NWs) are gaining ground for similar applications and, as with all biomaterials, their cytotoxicity is an important factor to be considered before conducting biological studies with them. In this work, the cytotoxic effects of nickel NWs (Ni NWs) were investigated in terms of cell viability and damage to the cellular membrane. Ni NWs with an average diameter of 30-34 nm were prepared by electrodeposition in nanoporous alumina templates. The templates were obtained by a two-step anodization process with oxalic acid on an aluminum substrate. Characterization of NWs was done using X-Ray diffraction (XRD) and energy dispersive X-Ray analysis (EDAX), whereas their morphology was observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cell viability studies were carried out on human colorectal carcinoma cells HCT 116 by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) cell proliferation colorimetric assay, whereas the lactate dehydrogenase (LDH) homogenous membrane fluorimetric assay was used to measure the degree of cell membrane rupture. The density of cell seeding was calculated to obtain a specific cell number and confluency before treatment with NWs. Optical readings of the cell-reduced MTT products were measured at 570 nm, whereas fluorescent LDH membrane leakage was recorded with an excitation wavelength of 525 nm and an emission wavelength of 580 - 640 nm. The effects of NW length, cell exposure time, as well as NW:cell ratio, were evaluated through both cytotoxic assays. The results show that cell viability due to Ni NWs is affected depending on both exposure time and NW number. On the other hand, membrane rupture and leakage was only significant at later exposure times. Both

  12. Exercise regulates breast cancer cell viability

    DEFF Research Database (Denmark)

    Dethlefsen, Christine; Lillelund, Christian; Midtgaard, Julie

    2016-01-01

    Purpose: Exercise decreases breast cancer risk and disease recurrence, but the underlying mechanisms are unknown. Training adaptations in systemic factors have been suggested as mediating causes. We aimed to examine if systemic adaptations to training over time, or acute exercise responses......, in breast cancer survivors could regulate breast cancer cell viability in vitro. Methods: Blood samples were collected from breast cancer survivors, partaking in either a 6-month training intervention or across a 2 h acute exercise session. Changes in training parameters and systemic factors were evaluated...... and pre/post exercise-conditioned sera from both studies were used to stimulate breast cancer cell lines (MCF-7, MDA-MB-231) in vitro. Results: Six months of training increased VO2peak (16.4 %, p

  13. Artificial evolution by viability rather than competition.

    Directory of Open Access Journals (Sweden)

    Andrea Maesani

    Full Text Available Evolutionary algorithms are widespread heuristic methods inspired by natural evolution to solve difficult problems for which analytical approaches are not suitable. In many domains experimenters are not only interested in discovering optimal solutions, but also in finding the largest number of different solutions satisfying minimal requirements. However, the formulation of an effective performance measure describing these requirements, also known as fitness function, represents a major challenge. The difficulty of combining and weighting multiple problem objectives and constraints of possibly varying nature and scale into a single fitness function often leads to unsatisfactory solutions. Furthermore, selective reproduction of the fittest solutions, which is inspired by competition-based selection in nature, leads to loss of diversity within the evolving population and premature convergence of the algorithm, hindering the discovery of many different solutions. Here we present an alternative abstraction of artificial evolution, which does not require the formulation of a composite fitness function. Inspired from viability theory in dynamical systems, natural evolution and ethology, the proposed method puts emphasis on the elimination of individuals that do not meet a set of changing criteria, which are defined on the problem objectives and constraints. Experimental results show that the proposed method maintains higher diversity in the evolving population and generates more unique solutions when compared to classical competition-based evolutionary algorithms. Our findings suggest that incorporating viability principles into evolutionary algorithms can significantly improve the applicability and effectiveness of evolutionary methods to numerous complex problems of science and engineering, ranging from protein structure prediction to aircraft wing design.

  14. The relationship between sperm viability and DNA fragmentation rates.

    Science.gov (United States)

    Samplaski, Mary K; Dimitromanolakis, Apostolos; Lo, Kirk C; Grober, Ethan D; Mullen, Brendan; Garbens, Alaina; Jarvi, Keith A

    2015-05-14

    In humans, sperm DNA fragmentation rates have been correlated with sperm viability rates. Reduced sperm viability is associated with high sperm DNA fragmentation, while conversely high sperm viability is associated with low rates of sperm DNA fragmentation. Both elevated DNA fragmentation rates and poor viability are correlated with impaired male fertility, with a DNA fragmentation rate of >30% indicating subfertility. We postulated that in some men, the sperm viability assay could predict the sperm DNA fragmentation rates. This in turn could reduce the need for sperm DNA fragmentation assay testing, simplifying the infertility investigation and saving money for infertile couples. All men having semen analyses with both viability and DNA fragmentation testing were identified via a prospectively collected database. Viability was measured by eosin-nigrosin assay. DNA fragmentation was measured using the sperm chromosome structure assay. The relationship between DNA fragmentation and viability was assessed using Pearson's correlation coefficient. From 2008-2013, 3049 semen analyses had both viability and DNA fragmentation testing. A strong inverse relationship was seen between sperm viability and DNA fragmentation rates, with r=-0.83. If viability was ≤50% (n=301) then DNA fragmentation was ≥ 30% for 95% of the samples. If viability was ≥75% (n=1736), then the DNA fragmentation was ≤30% for 95% of the patients. Sperm viability correlates strongly with DNA fragmentation rates. In men with high levels of sperm viability≥75%, or low levels of sperm viability≤ 30%, DFI testing may be not be routinely necessary. Given that DNA fragmentation testing is substantially more expensive than vitality testing, this may represent a valuable cost-saving measure for couples undergoing a fertility evaluation.

  15. Bacterial abundance and viability in rainwater associated with cyclones, stationary fronts and typhoons in southwestern Japan

    Science.gov (United States)

    Hu, Wei; Murata, Kotaro; Toyonaga, Satoshi; Zhang, Daizhou

    2017-10-01

    The abundance and viability of bacterial cells in rainwater at a suburban site in southwestern Japan between October 2014 and September 2015 were measured and their distinctiveness, according to synoptic weather systems, i.e., cyclones (cold fronts), stationary fronts (including Meiyu and non-Meiyu fronts) and typhoons, was examined. On average, the cell concentration of bacteria in the rainwater was 2.3 ± 1.5 × 104 cells mL-1, and bacterial viability, the ratio of viable cells to total cells, was 80 ± 10%. In the rainwater of cyclones when clouds were induced by the intrusion of continental air, the bacterial concentration was higher (3.5 ± 1.6 × 104 cells mL-1) and the viability was lower (75 ± 8%) than in the rainwater of other types. In the rainwater of Meiyu fronts and typhoons when clouds were significantly influenced by marine air, bacterial concentrations were 1.5 ± 0.5 × 104 and 1.2 ± 0.3 × 104 cells mL-1, and bacterial viabilities were 84 ± 7% and 85 ± 7%, respectively. In the rainwater of non-Meiyu stationary fronts, the bacterial concentration was 2.4 ± 1.6 × 104 cells mL-1, and the viability was 78 ± 14%. Abundant bacteria were associated with ions nss-SO42-, nss-Ca2+, and NO3- in rainwater, but bacterial concentrations did not correlate with the ratios of airborne particle concentrations to the precipitation amounts. Further investigations with correlation and principal component analysis combining bacteria and ion species revealed that bacteria in the rainwater were likely enclosed in clouds at the stage of cloud formation in addition to below-cloud removal, and bacteria involved in the rainwater did not show confirmable growth.

  16. Effects of ozone gas on skin flaps viability in rats: an experimental study.

    Science.gov (United States)

    Güner, Mehmet Haşim; Görgülü, Tahsin; Olgun, Abdulkerim; Torun, Merve; Kargi, Eksal

    2016-10-01

    The main purpose of this study was to assess the effects of ozone gas on the viability of flaps for reconstruction and to determine the optimum application method. The antioxidant, immunomodulatory, and reperfusion effects of ozone gas have been previously assessed, and successful results have been reported. However, only one study has investigated the effect of ozone gas on flap viability. In the present study, it was hypothesised that the antioxidant and reperfusion effects of ozone gas would enhance flap viability. Forty female Wistar rats were randomly divided into four groups of 10 rats each. A cranial-based, 3 × 11 cm modified McFarlane flap including the panniculus carnosus was raised from the dorsum of a rat and re-sutured to its own bed using 3/0 sharp propylene. Group 1 (n = 10): no pharmacological agent was used after the operation. Group 2 (n = 10): vegetable (olive) oil group; vegetable-oil-impregnated gauze was used as a dressing for 7 days. Group 3 (n = 10): Vegetable (olive) oil with ozone peroxide group; vegetable oil with ozone peroxide-impregnated gauze was used as a dressing for 7 days. Group 4 (n = 10): Hemo-ozone therapy group; hemo-ozone therapy was applied rectally once every day for 7 days. All rats were sacrificed at the end of week 1 and assessed macroscopically and histopathologically. The proportion of substantive necrosis was less in group 4 than in the other three groups. Survival area ratios were better in groups 2 and 3 than in group 1; however, there was no significant difference between groups 2 and 3. No significant differences in the histopathological scores were observed among the groups. Ozone gas enhanced flap viability. No differences in flap viability were observed between the vegetable oil and vegetable oil with ozone peroxide groups. The greatest benefit ratios were found in the hemo-ozone therapy group.

  17. RELATIONSHIP BETWEEN MOTILITY AND VIABILITY PARAMETERS OF FROZEN-THAWED BULL SPERMATOZOA

    Directory of Open Access Journals (Sweden)

    Eliška Špaleková

    2013-02-01

    Full Text Available The aim of this study was to determine relationship between parameters of spermatozoa motility (total motility - TM and progressive movement - PM and viability of bull frozen-thawed spermatozoa (dead spermatozoa ratio, apoptotic spermatozoa ratio and plasma membrane integrity. Motility parameters were evaluated using computer-assisted semen analysis (CASA. Parameters of spermatozoa viability were analysed using fluorescent dyes PNA-FITC (plasma membrane, Yo-Pro-1 and propidium iodide (PI. All bulls (n=6 were divided into two groups. First group (n=3 A – better bulls with total motility after thawing over 40% and the second group (n=3 B – with total motility lower than 40%. It was observed significantly (P<0.001 higher TM and PM in group A. No significant differences in velocity parameters and ALH between the group A and B were detected. Occurrence of spermatozoa with disrupted membranes, dead/necrotic spermatozoa and apoptotic spermatozoa was significantly lower in the group A. Bulls in the group A showed significantly higher cleavage rate of embryos. These motility and viability characteristics are associated with a higher embryo cleavage rate in in vitro fertilizatioThe aim of this study was to determine relationship between parameters of spermatozoa motility (total motility - TM and progressive movement - PM and viability of bull frozen-thawed spermatozoa (dead spermatozoa ratio, apoptotic spermatozoa ratio and plasma membrane integrity. Motility parameters were evaluated using computer-assisted semen analysis (CASA. Parameters of spermatozoa viability were analysed using fluorescent dyes PNA-FITC (plasma membrane, Yo-Pro-1 and propidium iodide (PI. All bulls (n=6 were divided into two groups. First group (n=3 A – better bulls with total motility after thawing over 40% and the second group (n=3 B – with total motility lower than 40%. It was observed significantly (P<0.001 higher TM and PM in group A. No significant differences in

  18. ALCAPA: the role of myocardial viability studies in determining prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Browne, Lorna P.; Krishnamurthy, Rajesh [Texas Children' s Hospital, Department of Diagnostic Imaging, Houston, TX (United States); Kearney, Debra [Texas Children' s Hospital, Department of Pathology, Houston, TX (United States); Taylor, Michael D.; Slesnick, Timothy C.; Nutting, Arni C. [Texas Children' s Hospital, Department of Cardiology, Houston, TX (United States); Chung, Taylor [Children' s Hospital and Research Center, Department of Diagnostic Imaging, Oakland, CA (United States)

    2010-02-15

    ALCAPA is optimally treated by coronary artery reimplantation early in neonatal life. Delayed diagnosis, however, is not infrequent, because symptoms often do not manifest until about 3 months of age, coinciding with the physiological nadir in pulmonary vascular resistance. With delayed diagnosis, there is potential for coronary steal and irreversible myocardial injury, which worsens outcome. To assess the utility of MRI in determining prognosis in children with surgically corrected ALCAPA. A retrospective chart review was performed in two children with ALCAPA who underwent coronary reimplantation and postoperative cardiac MRI. Both children subsequently underwent cardiac transplantation. The imaging findings and pathological findings at explant are presented. In both children, there was severe, globally depressed left ventricular systolic function and abnormal delayed enhancement in a predominantly subendocardial distribution. Pathological examination of the cardiac explants showed extensive fibrotic tissue, which correlated with areas of abnormal delayed enhancement on MRI. Severe reduction in systolic function and presence of delayed enhancement indicate extensive myocardial injury and pathologically correlate with irreversible fibrotic changes, which may help identify a subgroup of children who will not recover ventricular function and ultimately require heart transplantation. (orig.)

  19. Sperm viability staining in ecology and evolution: potential pitfalls

    DEFF Research Database (Denmark)

    Holman, Luke

    2009-01-01

    a number of interesting results, it has some potential pitfalls that have rarely been discussed. In the present paper, I review the major findings of ecology and evolution studies employing sperm viability staining and outline the method's principle limitations. The key problem is that the viability assay......The causes and consequences of variation in sperm quality, survival and ageing are active areas of research in ecology and evolution. In order to address these topics, many recent studies have measured sperm viability using fluorescent staining. Although sperm viability staining has produced...

  20. Assessing the Viability of Tiger Subpopulations in a Fragmented Landscape

    National Research Council Canada - National Science Library

    Matthew Linkie; Guillaume Chapron; Deborah J. Martyr; Jeremy Holden; Nigel Leader-Williams

    2006-01-01

    .... This study aimed to provide such information for tigers in the Kerinci Seblat (KS) region, Sumatra, by identifying and assessing subpopulation viability under different management strategies. 2...

  1. Fault Detection and Isolation using Viability Theory and Interval Observers

    Science.gov (United States)

    Ghaniee Zarch, Majid; Puig, Vicenç; Poshtan, Javad

    2017-01-01

    This paper proposes the use of interval observers and viability theory in fault detection and isolation (FDI). Viability theory develops mathematical and algorithmic methods for investigating the adaptation to viability constraints of evolutions governed by complex systems under uncertainty. These methods can be used for checking the consistency between observed and predicted behavior by using simple sets that approximate the exact set of possible behavior (in the parameter or state space). In this paper, fault detection is based on checking for an inconsistency between the measured and predicted behaviors using viability theory concepts and sets. Finally, an example is provided in order to show the usefulness of the proposed approach.

  2. The effects of storage conditions on the viability of ...

    African Journals Online (AJOL)

    The effects of storage conditions on the viability of enteropathogenics bacteria in biobanking of human stools: Cases of Yersinia enterocolitica, Salmonella enterica Typhimurium and Vibrio cholerae O: 1.

  3. Storage Viability and Optimization Web Service

    Energy Technology Data Exchange (ETDEWEB)

    Stadler, Michael; Marnay, Christ; Lai, Judy; Siddiqui, Afzal; Limpaitoon, Tanachai; Phan, Trucy; Megel, Olivier; Chang, Jessica; DeForest, Nicholas

    2010-10-11

    Non-residential sectors offer many promising applications for electrical storage (batteries) and photovoltaics (PVs). However, choosing and operating storage under complex tariff structures poses a daunting technical and economic problem that may discourage potential customers and result in lost carbon and economic savings. Equipment vendors are unlikely to provide adequate environmental analysis or unbiased economic results to potential clients, and are even less likely to completely describe the robustness of choices in the face of changing fuel prices and tariffs. Given these considerations, researchers at Lawrence Berkeley National Laboratory (LBNL) have designed the Storage Viability and Optimization Web Service (SVOW): a tool that helps building owners, operators and managers to decide if storage technologies and PVs merit deeper analysis. SVOW is an open access, web-based energy storage and PV analysis calculator, accessible by secure remote login. Upon first login, the user sees an overview of the parameters: load profile, tariff, technologies, and solar radiation location. Each parameter has a pull-down list of possible predefined inputs and users may upload their own as necessary. Since the non-residential sectors encompass a broad range of facilities with fundamentally different characteristics, the tool starts by asking the users to select a load profile from a limited cohort group of example facilities. The example facilities are categorized according to their North American Industry Classification System (NAICS) code. After the load profile selection, users select a predefined tariff or use the widget to create their own. The technologies and solar radiation menus operate in a similar fashion. After these four parameters have been inputted, the users have to select an optimization setting as well as an optimization objective. The analytic engine of SVOW is LBNL?s Distributed Energy Resources Customer Adoption Model (DER-CAM), which is a mixed

  4. Incorporating evolutionary processes into population viability models.

    Science.gov (United States)

    Pierson, Jennifer C; Beissinger, Steven R; Bragg, Jason G; Coates, David J; Oostermeijer, J Gerard B; Sunnucks, Paul; Schumaker, Nathan H; Trotter, Meredith V; Young, Andrew G

    2015-06-01

    We examined how ecological and evolutionary (eco-evo) processes in population dynamics could be better integrated into population viability analysis (PVA). Complementary advances in computation and population genomics can be combined into an eco-evo PVA to offer powerful new approaches to understand the influence of evolutionary processes on population persistence. We developed the mechanistic basis of an eco-evo PVA using individual-based models with individual-level genotype tracking and dynamic genotype-phenotype mapping to model emergent population-level effects, such as local adaptation and genetic rescue. We then outline how genomics can allow or improve parameter estimation for PVA models by providing genotypic information at large numbers of loci for neutral and functional genome regions. As climate change and other threatening processes increase in rate and scale, eco-evo PVAs will become essential research tools to evaluate the effects of adaptive potential, evolutionary rescue, and locally adapted traits on persistence. © 2014 Society for Conservation Biology.

  5. Adverse respiratory outcome after premature rupture of membranes before viability.

    Science.gov (United States)

    Verspyck, Eric; Bisson, Violene; Roman, Horace; Marret, Stéphane

    2014-03-01

    To determine whether preterm premature rupture of membranes (PPROM) before 24 weeks is an independent risk factor for poor outcome in preterm neonates. A retrospective comparative cohort study was conducted, including viable premature infants born between 25 and 34-weeks gestation. Each preterm case with early PPROM was matched with two preterm controls of the same gestational age at birth, sex and birth date and who were born spontaneously with intact membranes. Logistic regression was performed to identify independent risk factors associated with composite respiratory and perinatal adverse outcomes for the overall population of preterm infants. Thirty-five PPROM cases were matched with 70 controls. Extreme prematurity (26-28 weeks) was an independent risk factor for composite perinatal adverse outcomes [odds ratio (OR) 43.9; p = 0.001]. Extreme prematurity (OR 42.9; p = 0.001), PPROM (OR 7.1; p = 0.01), male infant (OR 5.2; p = 0.02) and intrauterine growth restriction (IUGR, OR 4.8; p = 0.04) were factors for composite respiratory adverse outcomes. Preterm premature rupture of membranes before viability represents an independent risk factor for composite respiratory adverse outcomes in preterm neonates. Extreme prematurity may represent the main risk factor for both composite respiratory and perinatal adverse outcomes. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  6. Establishing guidelines to retain viability of probiotics during spray drying

    NARCIS (Netherlands)

    Perdana, J.A.; Fox, M.B.; Boom, R.M.; Schutyser, M.A.I.

    2014-01-01

    We present a model-based approach to map processing conditions suitable to spray dry probiotics with minimal viability loss. The approach combines the drying history and bacterial inactivation kinetics to predict the retention of viability after drying. The approach was used to systematically assess

  7. Evaluation of pollen viability, stigma receptivity and fertilization ...

    African Journals Online (AJOL)

    To provide theoretical basis for artificial pollination in Lagerstroemia indica L., pollen viability and stigma receptivity were tested and the morphological change of stigma was observed. Pollen viability tested by in vitro culture, stigma receptivity examined by benzidine-H2O2 testing and fruit set estimated by field artificial ...

  8. Viability of dielectrophoretically trapped neuronal cortical cells in culture

    NARCIS (Netherlands)

    Heida, Tjitske; Vulto, P; Rutten, Wim; Marani, Enrico

    2001-01-01

    Negative dielectrophoretic trapping of neural cells is an efficient way to position neural cells on the electrode sites of planar micro-electrode arrays. The preservation of viability of the neural cells is essential for this approach. This study investigates the viability of postnatal cortical rat

  9. 37 CFR 1.807 - Viability of deposit.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Viability of deposit. 1.807... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit of Biological Material § 1.807 Viability of deposit. (a) A deposit of biological material that is capable of...

  10. Evaluation of pollen viability, stigma receptivity and fertilization ...

    African Journals Online (AJOL)

    AJL

    2013-11-13

    Nov 13, 2013 ... To provide theoretical basis for artificial pollination in Lagerstroemia indica L., pollen viability and stigma receptivity were tested and the morphological change of stigma was observed. Pollen viability tested by in vitro culture, stigma receptivity examined by benzidine-H2O2 testing and fruit set estimated.

  11. Studies On Fermentation, Alcohol Production And Viability In ...

    African Journals Online (AJOL)

    The reverse was true in the sugarcane bagasse medium. Yeasts with high viability tended to have high alcohol production ability in the sucrose medium and vice-versa. KEY WORDS: Alcohol production; fermentation; induced mutants; Saccharomyces cerevisiae; viability. Global Journal of Pure and Applied Sciences ...

  12. The Economy and Democracy: Viability and Challenges for ...

    African Journals Online (AJOL)

    The Economy and Democracy: Viability and Challenges for Sustainable Democratisation in Nigeria. ... Economic and Policy Review ... the viability for developing sustainable democracy in Nigeria against the background of the country's enormous economic potentials and the economic reforms introduced following the ...

  13. Pollen viability and germination in Jatropha ribifolia and Jatropha ...

    African Journals Online (AJOL)

    The aim of this work is to assess pollen viability using the staining technique and in vitro germination with different concentrations of sucrose in Jatropha ribifolia and Jatropha mollissima, contributing to the knowledge of the reproductive biology and subsidizing their conservation, management and utilization. Pollen viability ...

  14. Viability, Advantages and Design Methodologies of M-Learning Delivery

    Science.gov (United States)

    Zabel, Todd W.

    2010-01-01

    The purpose of this study was to examine the viability and principle design methodologies of Mobile Learning models in developing regions. Demographic and market studies were utilized to determine the viability of M-Learning delivery as well as best uses for such technologies and methods given socioeconomic and political conditions within the…

  15. Viability and functional integrity of washed platelets

    Energy Technology Data Exchange (ETDEWEB)

    Pineda, A.A.; Zylstra, V.W.; Clare, D.E.; Dewanjee, M.K.; Forstrom, L.A.

    1989-07-01

    The viability and functional integrity of saline- and ACD-saline-washed platelets were compared with those of unwashed platelets. After template bleeding time (TBT) was measured, 15 healthy volunteers underwent plateletpheresis and ingested 600 mg of aspirin. Autologous /sup 111/In-labeled platelets were transfused: unwashed (n = 5), washed with 0.9 percent saline solution (SS) (n = 5), and washed with a buffered 12.6 percent solution of ACD-A in 0.9 percent saline solution (n = 5). After transfusion, we measured TBT at 1, 4, and 24 hours; platelet survival at 10 minutes and 1, 4, and 24 hours and daily for 6 days; and the percentage of uptake in liver and spleen by quantitative whole-body radionuclide scintigraphy at 24 and 190 hours. We found that saline washing affected platelet recovery, 23.47 +/- 12 percent (p less than 0.001) as compared to 52.43 +/- 17 percent (p less than 0.002) for ACD-saline and 73.17 +/- 8 percent for control; that saline washing resulted in a greater liver uptake than control and ACD-saline-washed platelets (31.9 +/- 8% (p less than 0.001) vs 17.7 +/- 4.1 and 19.3 +/- 2.1% (p greater than 0.1), respectively); that, unlike control and ACD-saline-washed platelets, saline-washed platelets did not shorten bleeding time; and that neither type of washing affected survival. Although ACD-saline washing affects recovery, it also results in intact function, normal survival, higher recovery than SS platelets, and no significant liver uptake.

  16. Assessment of probiotic viability during Cheddar cheese manufacture and ripening using propidium monoazide-PCR quantification

    Directory of Open Access Journals (Sweden)

    Emilie eDesfossés-Foucault

    2012-10-01

    Full Text Available The use of a suitable food carrier such as cheese could significantly enhance probiotic viability during storage. The main goal of this study was to assess viability of commercial probiotic strains during Cheddar cheesemaking and ripening (four to six months by comparing the efficiency of microbiological and molecular approaches. Molecular methods such as quantitative PCR (qPCR allow bacterial quantification, and DNA-blocking molecules such as propidium monoazide (PMA select only the living cells’ DNA. Cheese samples were manufactured with a lactococci starter and with one of three probiotic strains (Bifidobacterium animalis subsp. lactis BB-12, Lactobacillus rhamnosus RO011 or Lactobacillus helveticus RO052 or a mixed culture containing B. animalis subsp. lactis BB-12 and L. helveticus RO052 (MC1, both lactobacilli strains (MC2 or all three strains (MC3. DNA extractions were then carried out on PMA-treated and non-treated cell pellets in order to assess PMA treatment efficiency, followed by quantification using the 16S rRNA gene, the elongation factor Tu gene (tuf or the transaldolase gene (tal. Results with intact/dead ratios of bacteria showed that PMA-treated cheese samples had a significantly lower bacterial count than non-treated DNA samples (P<0.005, confirming that PMA did eliminate dead bacteria from PCR quantification. For both quantification methods, the addition of probiotic strains seemed to accelerate the loss of lactococci viability in comparison to control cheese samples, especially when L. helveticus RO052 was added. Viability of all three probiotic strains was also significantly reduced in mixed culture cheese samples (P<0.0001, B. animalis subsp. lactis BB-12 being the most sensitive to the presence of other strains. However, all probiotic strains did retain their viability (log nine cfu/g of cheese throughout ripening. This study was successful in monitoring living probiotic species in Cheddar cheese samples through PMA-qPCR.

  17. Financial Key Ratios

    OpenAIRE

    Tănase Alin-Eliodor

    2014-01-01

    This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

  18. An Optimized Injectable Hydrogel Scaffold Supports Human Dental Pulp Stem Cell Viability and Spreading

    Directory of Open Access Journals (Sweden)

    T. D. Jones

    2016-01-01

    Full Text Available Introduction. HyStem-C™ is a commercially available injectable hydrogel composed of polyethylene glycol diacrylate (PEGDA, hyaluronan (HA, and gelatin (Gn. These components can be mechanically tuned to enhance cell viability and spreading. Methods. The concentration of PEGDA with an added disulfide bond (PEGSSDA was varied from 0.5 to 8.0% (w/v to determine the optimal concentration for injectable clinical application. We evaluated the cell viability of human dental pulp stem cells (hDPSCs embedded in 2% (w/v PEGSSDA-HA-Gn hydrogels. Volume ratios of HA : Gn from 100 : 0 to 25 : 75 were varied to encourage hDPSC spreading. Fibronectin (Fn was added to our model to determine the effect of extracellular matrix protein concentration on hDPSC behavior. Results. Our preliminary data suggests that the hydrogel gelation time decreased as the PEGSSDA cross-linker concentration increased. The PEGSSDA-HA-Gn was biocompatible with hDPSCs, and increased ratios of HA : Gn enhanced cell viability for 14 days. Additionally, cell proliferation with added fibronectin increased significantly over time at concentrations of 1.0 and 10.0 μg/mL in PEGDA-HA-Gn hydrogels, while cell spreading significantly increased at Fn concentrations of 0.1 μg/mL. Conclusions. This study demonstrates that PEG-based injectable hydrogels maintain hDPSC viability and facilitate cell spreading, mainly in the presence of extracellular matrix (ECM proteins.

  19. Polyvinyl Alcohol/Lithospermum Erythrorhizon Nanofibrous Membrane: Characterizations, In Vitro Drug Release, and Cell Viability

    Directory of Open Access Journals (Sweden)

    Ching-Wen Lou

    2017-11-01

    Full Text Available This study proposes an optimization process of the Lithospermum erythrorhizon (LE extraction with a higher purity of shikonin (SK. The influence of extraction temperature on the concentration of SK is examined, and an in vitro cell viability assay is used to examine the optimal concentration of SK. Afterwards, polyvinyl alcohol (PVA/LE solutions at ratios of 90/10, 80/20, and 70/30 w/w are electrospun into LE electrospun nanofibrous membranes (LENMs. The optimal manufacture parameters of LENMs are evaluated based on the test results of in vitro drug release test and cell viability assay. The optimal concentration occurs when the extraction temperature is −10 °C. The purity of the LE extract reaches 53.8% and the concentration of SK is 1.07 mg/mL. Moreover, the cell viability of nanofibrous membranes significantly increases to 136.8% when 0.7 μM SK is used. The diameter of nanofibers of LENM is decreased by 43.9% when the ratio of PVA solution to LE extract is 70/30 (w/w. 80/20 (w/w LENM has the maximum amount of drug release of 79% for a continuous period of 48 h. In particular, 90/10 (w/w LENM can create the maximum cell proliferation of 157.5% in a 24-h in vitro cell viability assay. This suggests that LENM has great potential to be used in facilitating tissue regeneration and wound healing.

  20. The market viability of nuclear hydrogen technologies.

    Energy Technology Data Exchange (ETDEWEB)

    Botterud, A.; Conzelmann, G.; Petri, M. C.; Yildiz, B.

    2007-04-06

    The Department of Energy Office of Nuclear Energy is supporting system studies to gain a better understanding of nuclear power's potential role in a hydrogen economy and what hydrogen production technologies show the most promise. This assessment includes identifying commercial hydrogen applications and their requirements, comparing the characteristics of nuclear hydrogen systems to those market requirements, evaluating nuclear hydrogen configuration options within a given market, and identifying the key drivers and thresholds for market viability of nuclear hydrogen options. One of the objectives of the current analysis phase is to determine how nuclear hydrogen technologies could evolve under a number of different futures. The outputs of our work will eventually be used in a larger hydrogen infrastructure and market analysis conducted for DOE-EE using a system-level market simulation tool now underway. This report expands on our previous work by moving beyond simple levelized cost calculations and looking at profitability, risk, and uncertainty from an investor's perspective. We analyze a number of technologies and quantify the value of certain technology and operating characteristics. Our model to assess the profitability of the above technologies is based on Real Options Theory and calculates the discounted profits from investing in each of the production facilities. We use Monte-Carlo simulations to represent the uncertainty in hydrogen and electricity prices. The model computes both the expected value and the distribution of discounted profits from a production plant. We also quantify the value of the option to switch between hydrogen and electricity production in order to maximize investor profits. Uncertainty in electricity and hydrogen prices can be represented with two different stochastic processes: Geometric Brownian Motion (GBM) and Mean Reversion (MR). Our analysis finds that the flexibility to switch between hydrogen and electricity leads

  1. COST IMPACT OF ROD CONSOLIDATION ON THE VIABILITY ASSESSMENT DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    D. Lancaster

    1999-03-29

    The cost impact to the Civilian Radioactive Waste Management System of using rod consolidation is evaluated. Previous work has demonstrated that the fuel rods of two assemblies can be packed into a canister that can fit into the same size space as that used to store a single assembly. The remaining fuel assembly hardware can be compacted into the same size canisters with a ratio of 1 hardware canister per each 6 to 12 assemblies. Transportation casks of the same size as currently available can load twice the number of assemblies by placing the compacted assemblies in the slots currently designed for a single assembly. Waste packages similarly could contain twice the number of assemblies; however, thermal constraints would require considering either a low burnup or cooling. The analysis evaluates the impact of rod consolidation on CRWMS costs for consolidation at prior to transportation and for consolidation at the Monitored Geological Repository surface facility. For this study, no design changes were made to either the transport casks or waste packages. Waste package designs used for the Viability Assessment design were employed but derated to make the thermal limits. A logistics analysis of the waste was performed to determine the number of each waste package with each loading. A review of past rod consolidation experience found cost estimates which range from $10/kgU to $32/kgU. $30/kgU was assumed for rod consolidation costs prior to transportation. Transportation cost savings are about $17/kgU and waste package cost savings are about $21/kgU. The net saving to the system is approximately $500 million if the consolidation is performed prior to transportation. If consolidation were performed at the repository surface facilities, it would cost approximately $15/kgU. No transportation savings would be realized. The net savings for consolidation at the repository site would be about $400 million dollars.

  2. Puget Sound steelhead life cycle model analyses - Population Viability Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This research was initiated by the Puget Sound Steelhead Technical Recovery Team to develop viability criteria for threatened Puget Sound steelhead and to support...

  3. Cadmium affects the mitochondrial viability and the acid soluble ...

    African Journals Online (AJOL)

    Cadmium affects the mitochondrial viability and the acid soluble thiols concentration in liver, kidney, heart and gills of Ancistrus brevifilis (Eigenmann, 1920). P Velasquez-Vottelerd, Y Anton, R Salazar-Lugo ...

  4. STUDY ON POLLEN VIABILITY AS BIOINDICATOR OF AIR QUALITY

    Directory of Open Access Journals (Sweden)

    Florentina ŞTEFLEA

    2012-01-01

    Full Text Available The aim of this research is to estimate the relationship between pollen viability and atmospheric pollution (in polluted and non-polluted conditions. The study was carried out in the city of Timisoara. Two areas, with different intensity of road traffic (very high and absent but all characterized by the presence of the same plant species, were selected. The pollen of herbaceous spontaneous species, arboreal species and a shrub species was used (Robinia pseudacacia, Aesculus x carnea, Catalpa bignonioides, Albizzia julibrissin, Rosa canina, Sambucus nigra, Malva neglecta, Ranunculus acer, Trifolium repens, Cichorium intybus. The pollen of these species was treated with TTC (2, 3, 5 Tryphenil-Tetrazolium-Chloride staining solution and viability was then estimated by light microscopy. The results of the mean pollen viability percentage of the examined species are reported. Pollen viability of herbaceous plants is significantly different between the two environments.

  5. Maintaining yeast viability in continuous primary beer fermentation

    National Research Council Canada - National Science Library

    Pires, Eduardo J; Teixeira, José A; Brányik, Tomás; Côrte‐Real, Manuela; Vicente, António A

    2014-01-01

    .... This work was aimed at solving one of the most relevant obstacles to implementing ICT on a large scale in beer fermentations, namely the control of biomass and the maintenance of cell viability in a gas‐lift bioreactor...

  6. Desiccation-induced changes in viability, lipid peroxidation and ...

    African Journals Online (AJOL)

    user

    2012-05-31

    Hendry et al., 1992) and A. saccharinum (Pukacka and Ratajczak, 2006) and intermediate seeds like Azadirachta indica (Varghese and. Naithani, 2002), Coffea Arabica (Dussert et al., 2006), indicating that loss of seed viability ...

  7. Femtosecond optical transfection of cells:viability and efficiency

    National Research Council Canada - National Science Library

    D. Stevenson; B. Agate; X. Tsampoula; P. Fischer; C. T. A. Brown; W. Sibbett; A. Riches; F. Gunn-Moore; K. Dholakia

    2006-01-01

    .... However, there remains no study into the true efficiency of this procedure. Here, we present a detailed analysis of transfection efficiency and cell viability for femtosecond optical transfection using a titanium sapphire laser at 800 nm...

  8. Equine ovarian tissue viability after cryopreservation and in vitro culture

    Science.gov (United States)

    The efficiency of several cryoprotective agents were compared using both slow-freezing and vitrification methods. Results indicate that the viability of ovarian tissue cells increases when DMSO (slow-freezing) and ethylene glycol (vitrification) are used....

  9. Approximate viability for nonlinear evolution inclusions with application to controllability

    Directory of Open Access Journals (Sweden)

    Omar Benniche

    2016-12-01

    Full Text Available We investigate approximate viability for a graph with respect to fully nonlinear quasi-autonomous evolution inclusions. As application, an approximate null controllability result is given.

  10. A key inactivation factor of HeLa cell viability by a plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Takehiko; Yokoyama, Mayo [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Johkura, Kohei, E-mail: sato@ifs.tohoku.ac.jp [Department of Histology and Embryology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621 (Japan)

    2011-09-21

    Recently, a plasma flow has been applied to medical treatment using effects of various kinds of stimuli such as chemical species, charged particles, heat, light, shock wave and electric fields. Among them, the chemical species are known to cause an inactivation of cell viability. However, the mechanisms and key factors of this event are not yet clear. In this study, we focused on the effect of H{sub 2}O{sub 2} in plasma-treated culture medium because it is generated in the culture medium and it is also chemically stable compared with free radicals generated by the plasma flow. To elucidate the significance of H{sub 2}O{sub 2}, we assessed the differences in the effects of plasma-treated medium and H{sub 2}O{sub 2}-added medium against inactivation of HeLa cell viability. These two media showed comparable effects on HeLa cells in terms of the survival ratios, morphological features of damage processes, permeations of H{sub 2}O{sub 2} into the cells, response to H{sub 2}O{sub 2} decomposition by catalase and comprehensive gene expression. The results supported that among chemical species generated in a plasma-treated culture medium, H{sub 2}O{sub 2} is one of the main factors responsible for inactivation of HeLa cell viability. (fast track communication)

  11. Conidial vigor vs. viability as predictors of virulence of entomopathogenic fungi.

    Science.gov (United States)

    Faria, Marcos; Lopes, Rogério Biaggioni; Souza, Daniela Aguiar; Wraight, Stephen P

    2015-02-01

    We tested the hypothesis that debilitated conidia exhibiting slow-germination (requiring>16h to germinate) are less virulent than vigorous conidia exhibiting fast germination (requiring⩽16h to germinate). Preparations of Beauveria bassiana s.l. strain CG 1027 with variable ratios of vigorous to debilitated conidia were assayed against third-instar larvae of Spodoptera frugiperda. As the proportion of debilitated conidia in test preparations increased, LC50 expressed in terms of total viable conidia increased, while LC50 expressed solely in terms of vigorous conidia remained constant, indicating that vigorous conidia were responsible for nearly all mortality observed in the assays. Larvae treated with conidia from low-quality batches (with high proportions of debilitated conidia) survived consistently longer than those treated with comparable doses of conidia from high-quality batches. These results confirm our previous hypotheses that inclusion of debilitated conidia in viability assessments can lead to overestimation of the quality (potency) of mycoinsecticide preparations and support our recommendation for use of short incubation periods for assessing viability whenever viability is relied upon as an indicator of product quality. Copyright © 2015. Published by Elsevier Inc.

  12. Viability of spectral enhancement with harmonic stimuli

    Science.gov (United States)

    Digiovanni, Jeffrey J.

    2003-04-01

    Loss of spectral resolution is an established consequence of sensorineural hearing loss. Traditional hearing aid design includes amplification and compression. These do not, however, account for the loss in frequency resolution. Recently, spectral enhancement processing has been designed to at least partially restore aspects of frequency resolution. The critical feature of this design is to increase the peak to trough ratio of the speech spectrum. These have been implemented with mixed success [e.g., Miller et al. (1999); Franck et al. (1999)]. More recently, DiGiovanni et al. (2002) showed promising results for normal and hearing-impaired subjects with psychophysical noise stimuli. The goal of this study was to expand these results to harmonic stimuli while adding peaks at fixed formant places within the spectrum. In that regard, subjects listened in two psychophysical experiments: detecting an F2-like spectral increment in a broadband harmonic complex and detecting the increment with an additional fixed formant peak added at an appropriate F1 place. Preliminary results show that normally hearing subjects have an improved ability to detect a narrowband tone complex when there is a spectral decrement at frequencies adjacent to the increment. These results are further support that the idea of spectral enhancement is viable.

  13. On savings ratio.

    OpenAIRE

    Xiaochuan, Z.

    2011-01-01

    This paper explores the factors that affect saving and consumption behaviours, in a context where some believe that the high savings ratio of the East Asia and oil-producing countries is one major cause for the global imbalances and the crisis. The paper elaborates on the factors behind the high savings ratios in East Asia and oil producing countries and low savings ratios in the United States. It argues that the high savings in East Asia can mainly be explained by cultural and structural fac...

  14. Comparison of reintroduction and enhancement effects on metapopulation viability

    Science.gov (United States)

    Halsey, Samniqueka J; Bell, Timothy J.; McEachern, Kathryn; Pavlovic, Noel B.

    2015-01-01

    Metapopulation viability depends upon a balance of extinction and colonization of local habitats by a species. Mechanisms that can affect this balance include physical characteristics related to natural processes (e.g. succession) as well as anthropogenic actions. Plant restorations can help to produce favorable metapopulation dynamics and consequently increase viability; however, to date no studies confirm this is true. Population viability analysis (PVA) allows for the use of empirical data to generate theoretical future projections in the form of median time to extinction and probability of extinction. In turn, PVAs can inform and aid the development of conservation, recovery, and management plans. Pitcher's thistle (Cirsium pitcheri) is a dune endemic that exhibited metapopulation dynamics. We projected viability of three natural and two restored populations with demographic data spanning 15–23 years to determine the degree the addition of reintroduced population affects metapopulation viability. The models were validated by comparing observed and projected abundances and adjusting parameters associated with demographic and environmental stochasticity to improve model performance. Our chosen model correctly predicted yearly population abundance for 60% of the population-years. Using that model, 50-year projections showed that the addition of reintroductions increases metapopulation viability. The reintroduction that simulated population performance in early-successional habitats had the maximum benefit. In situ enhancements of existing populations proved to be equally effective. This study shows that restorations can facilitate and improve metapopulation viability of species dependent on metapopulation dynamics for survival with long-term persistence of C. pitcheri in Indiana likely to depend on continued active management.

  15. Dobutamine stress echocardiography and technetium-99m-tetrofosmin/fluorine 18-fluorodeoxyglucose single-photon emission computed tomography and influence of resting ejection fraction to assess myocardial viability in patients with severe left ventricular dysfunction and healed myocardial infarction.

    Science.gov (United States)

    Rambaldi, R; Poldermans, D; Bax, J J; Boersma, E; Valkema, R; Elhendy, A; Vletter, W B; Fioretti, P M; Roelandt, J R; Krenning, E P

    1999-07-15

    The purpose of this study was to compare 2 different techniques--dobutamine-atropine stress echocardiography (DSE) and dual-isotope simultaneous acquisition (technetium-99-m-tetrofosmin/fluorine 18-fluorodeoxyglucose) single-photon emission computed tomography (DISA-SPECT)--for assessment of viable myocardium. One hundred ten patients (mean age 55 +/- 9 years) with left ventricular (LV) dysfunction (mean LV ejection fraction 27 +/- 13%) underwent both DISA-SPECT and DSE. A 16-segment scoring model was adopted for both techniques. Four types of wall motion during DSE were assessed: (1) biphasic, improvement at low dose (10 microg/kg/min) with worsening at high dose; (2) worsening, deterioration without initial improvement; (3) sustained, persistent or late improvement; and (4) no change. Viability criteria were biphasic, worsening, and sustained improvement with DSE. Viability criteria with DISA-SPECT were normal perfusion and metabolism (normal), concordantly mildly reduced perfusion and metabolism (subendocardial scar), or severely reduced perfusion and increased metabolism (mismatch). Myocardium was considered nonviable with DSE in case of unchanged wall motion, or moderate reduction or absence in both technetium-99m-tetrofosmin perfusion and fluorodeoxyglucose uptake with DISA-SPECT. Of 1,756 of 1,760 analyzable LV segments, 1,373 (78%) had severe wall motion abnormalities at baseline (severe hypokinesia, akinesia, or dyskinesia). Of these abnormal segments, 282 (21%) were considered viable during DSE (63 [5%] with biphasic response, 47 [3%] with ischemia, and 172 [13%]) with sustained improvement, whereas 1,091 (79%) were considered nonviable. With DISA-SPECT, 396 (29%) segments were considered viable (312 [23%] with matched perfusion/metabolism and 84 [6%] with mismatch), whereas 977 segments (71%) were considered nonviable. Both techniques showed agreement for viability in 201 segments and 896 were concordantly classified as nonviable. Disagreement was

  16. Difference and ratio plots

    DEFF Research Database (Denmark)

    Svendsen, Anders Jørgen; Holmskov, U; Bro, Peter

    1995-01-01

    hitherto unnoted differences between controls and patients with either rheumatoid arthritis or systemic lupus erythematosus. For this we use simple, but unconventional, graphic representations of the data, based on difference plots and ratio plots. Differences between patients with Burkitt's lymphoma...... and systemic lupus erythematosus from another previously published study (Macanovic, M. and Lachmann, P.J. (1979) Clin. Exp. Immunol. 38, 274) are also represented using ratio plots. Our observations indicate that analysis by regression analysis may often be misleading....

  17. Importance of Donor Chondrocyte Viability for Osteochondral Allografts.

    Science.gov (United States)

    Cook, James L; Stannard, James P; Stoker, Aaron M; Bozynski, Chantelle C; Kuroki, Keiichi; Cook, Cristi R; Pfeiffer, Ferris M

    2016-05-01

    Osteochondral allograft (OCA) transplantation provides a biological treatment option for functional restoration of large articular cartilage defects in multiple joints. While successful outcomes after OCA transplantation have been linked to viable donor chondrocytes, the importance of donor cell viability has not been comprehensively validated. To use a canine model to determine the importance of donor chondrocyte viability at the time of implantation with respect to functional success of femoral condylar OCAs based on radiographic, gross, cell viability, histologic, biochemical, and biomechanical outcome measures. Controlled laboratory study. After approval was obtained from the institutional animal care and use committee, adult female dogs (N = 16) were implanted with 8-mm cylindrical OCAs from male dogs in the lateral and medial femoral condyles of 1 knee. OCAs were preserved for 28 or 60 days after procurement, and chondrocyte viability was quantified before implantation. Two different storage media, temperatures, and time points were used to obtain a spectrum of percentage chondrocyte viability at the time of implantation. A successful outcome was defined as an OCA that was associated with graft integration, maintenance of hyaline cartilage, lack of associated cartilage disorder, and lack of fibrillation, fissuring, or fibrous tissue infiltration of the allograft based on subjective radiographic, gross, and histologic assessments at 6 months after implantation. Chondrocyte viability ranged from 23% to 99% at the time of implantation. All successful grafts had >70% chondrocyte viability at the time of implantation, and no graft with chondrocyte viability <70% was associated with a successful outcome. Live-dead stained sections and histologic findings with respect to cell morphological features suggested that successful grafts were consistently composed of viable chondrocytes in lacunae, while grafts that were not successful were composed of nonviable

  18. A Classification Method for Seed Viability Assessment with Infrared Thermography

    Directory of Open Access Journals (Sweden)

    Sen Men

    2017-04-01

    Full Text Available This paper presents a viability assessment method for Pisum sativum L. seeds based on the infrared thermography technique. In this work, different artificial treatments were conducted to prepare seeds samples with different viability. Thermal images and visible images were recorded every five minutes during the standard five day germination test. After the test, the root length of each sample was measured, which can be used as the viability index of that seed. Each individual seed area in the visible images was segmented with an edge detection method, and the average temperature of the corresponding area in the infrared images was calculated as the representative temperature for this seed at that time. The temperature curve of each seed during germination was plotted. Thirteen characteristic parameters extracted from the temperature curve were analyzed to show the difference of the temperature fluctuations between the seeds samples with different viability. With above parameters, support vector machine (SVM was used to classify the seed samples into three categories: viable, aged and dead according to the root length, the classification accuracy rate was 95%. On this basis, with the temperature data of only the first three hours during the germination, another SVM model was proposed to classify the seed samples, and the accuracy rate was about 91.67%. From these experimental results, it can be seen that infrared thermography can be applied for the prediction of seed viability, based on the SVM algorithm.

  19. Tissue viability 2010 -2015:from good to great.

    Science.gov (United States)

    Milne, Jeanette; Ousey, Karen

    2010-09-01

    This paper explores the challenges of the changing face of the NHS with specific relation to the challenges for community-based tissue viability services following the publication of government documents that identify the need to provide a quality service for all patients in health-care settings. Patients receiving care in the community is paramount to the success of the NHS going forward; service redesign, improvements in quality, outcome tracking, seamless discharge and patient satisfaction/responsibilities has been heralded as the core prerequisites of successful services. Tissue viability is a relatively young specialism, with most services being nurse led and established less than 15 years. It is argued that in order to continue to be successful as a specialism, tissue viability has to challenge traditional patient and nursing beliefs and values.

  20. Multimodality imaging in the assessment of myocardial viability

    Science.gov (United States)

    Partington, Sara L.; Kwong, Raymond Y.

    2014-01-01

    The prevalence of heart failure due to coronary artery disease continues to increase, and it portends a worse prognosis than non-ischemic cardiomyopathy. Revascularization improves prognosis in these high-risk patients who have evidence of viability; therefore, optimal assessment of myocardial viability remains essential. Multiple imaging modalities exist for differentiating viable myocardium from scar in territories with contractile dysfunction. Given the multiple modalities available, choosing the best modality for a specific patient can be a daunting task. In this review, the physiology of myocardial hibernation and stunning will be reviewed. All the current methods available for assessing viability including echocardiography, cardiac magnetic resonance imaging, nuclear imaging with single photon emission tomography and positron emission tomography imaging and cardiac computed tomography will be reviewed. The effectiveness of the various techniques will be compared, and the limitations of the current literature will be discussed. PMID:21069458

  1. Viability of Lucilia sericata maggots after exposure to wound antiseptics.

    Science.gov (United States)

    Daeschlein, Georg; Napp, Matthias; Assadian, Ojan; von Podewils, Sebastian; Reese, Kevin; Hinz, Peter; Matiasek, Johannes; Spitzmueller, Romy; Humphreys, Paul; Jünger, Michael; Kramer, Axel

    2017-06-01

    After debridement and before dressing a wound with maggots of calliphorid flies, one frequently performed step is the application of antiseptics to the prepared wound bed. However, the concomitant application of antiseptic agents during maggot therapy is regarded controversial as antiseptics may interfere with maggots' viability. In this experimental in vitro study, the viability of fly maggots was investigated after exposure to various antiseptics frequently used in wound care. Here, we show that Lucilia sericata fly maggots can survive up to an hour's exposure to wound antiseptics such as octenidine, povidone-iodine or polihexanide. Concomitant short-term application of wound antiseptics together with maggots on wound beds is tolerated by larvae and does not impair their viability. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  2. Economic Viability of Brewery Spent Grain as a Biofuel

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    This report summarizes an investigation into the technical feasibility and economic viability of use grain wastes from the beer brewing process as fuel to generate the heat needed in subsequent brewing process. The study finds that while use of spent grain as a biofuel is technically feasible, the economics are not attractive. Economic viability is limited by the underuse of capital equipment. The investment in heating equipment requires a higher utilization that the client brewer currently anticipates. It may be possible in the future that changing factors may swing the decision to a more positive one.

  3. Economic viability of new launched school lunch programmes

    DEFF Research Database (Denmark)

    Jensen, Jørgen Dejgård; Smed, Sinne; Mørkbak, Morten Raun

    2013-01-01

    The objective of this paper is to investigate determinants for the viability of school lunch programmes with a zero-price start-up period. The study is based on a Danish pilot experiment, in which 38 schools were subsidized to provide free school lunch for all pupils during a two-month start...... activities related to the schools’ support and the users’ feeling of ownership, as well as internal professionalism and leadership in the implementation of the school lunch programme are important for the viability of the programme. Strong performance on the latter factors might to some extent compensate...... for the gap between cost and users’ willingness to pay for school lunches....

  4. Challenge testing of gametes to enhance their viability

    DEFF Research Database (Denmark)

    Callesen, Henrik

    2010-01-01

    of survival mechanism that enables them to come through the process. The details of the mechanism remain unknown but, if identified, it could have immense potential as a new way to improve the viability of embryos produced by ART. However, few publications describe systematic ways to challenge test gametes...... and then to use the results as a basis for improving gamete viability. Furthermore, new methods to monitor the reactions of gametes to such challenge tests are needed. In the present review, these two issues are discussed, as are some of the conditions necessary before a challenge test protocol can be part...

  5. Population-specific life histories contribute to metapopulation viability

    Science.gov (United States)

    Halsey, Samniqueka J.; Bell, Timothy J.; McEachern, A. Kathryn; Pavlovic, Noel B.

    2016-01-01

    Restoration efforts can be improved by understanding how variations in life-history traits occur within populations of the same species living in different environments. This can be done by first understanding the demographic responses of natural occurring populations. Population viability analysis continues to be useful to species management and conservation with sensitivity analysis aiding in the understanding of population dynamics. In this study, using life-table response experiments and elasticity analyses, we investigated how population-specific life-history demographic responses contributed to the metapopulation viability of the Federally threatened Pitcher's thistle (Cirsium pitcheri). Specifically, we tested the following hypotheses: (1) Subpopulations occupying different environments within a metapopulation have independent demographic responses and (2) advancing succession results in a shift from a demographic response focused on growth and fecundity to one dominated by stasis. Our results showed that reintroductions had a positive contribution to the metapopulation growth rate as compared to native populations which had a negative contribution. We found no difference in succession on the contribution to metapopulation viability. In addition, we identified distinct population-specific contributions to metapopulation viability and were able to associate specific life-history demographic responses. For example, the positive impact of Miller High Dunes population on the metapopulation growth rate resulted from high growth contributions, whereas increased time of plant in stasis for the State Park Big Blowout population resulted in negative contributions. A greater understanding of how separate populations respond in their corresponding environment may ultimately lead to more effective management strategies aimed at reducing extinction risk. We propose the continued use of sensitivity analyses to evaluate population-specific demographic influences on

  6. The rectilinear Steiner ratio

    Directory of Open Access Journals (Sweden)

    PO de Wet

    2005-06-01

    Full Text Available The rectilinear Steiner ratio was shown to be 3/2 by Hwang [Hwang FK, 1976, On Steiner minimal trees with rectilinear distance, SIAM Journal on Applied Mathematics, 30, pp. 104– 114.]. We use continuity and introduce restricted point sets to obtain an alternative, short and self-contained proof of this result.

  7. Gender Ratio in Dyslexia.

    Science.gov (United States)

    Miles, T. R.; Haslum, M. N.; Wheeler, T. J.

    1998-01-01

    A study involving 11,804 British children (age 10) found that when specified criteria for dyslexia were used, 269 children qualified as dyslexic. These included 223 boys and 46 girls, for a ratio of 4.51 to 1. Difficulties in interpreting these data are discussed and a defense of the criteria is provided. (Author/CR)

  8. The Reference Return Ratio

    DEFF Research Database (Denmark)

    Nicolaisen, Jeppe; Faber Frandsen, Tove

    2008-01-01

    The paper introduces a new journal impact measure called The Reference Return Ratio (3R). Unlike the traditional Journal Impact Factor (JIF), which is based on calculations of publications and citations, the new measure is based on calculations of bibliographic investments (references) and returns...

  9. Indices of cardiovascular function derived from peripheral pulse wave analysis using radial applanation tonometry: a measurement repeatability study

    OpenAIRE

    Crilly, Mike; Coch, Christoph; Bruce, Margaret; Clark, Hazel; Williams, David

    2007-01-01

    Abstract Pulse wave analysis (PWA) using applanation tonometry is a non-invasive technique for assessing cardiovascular function. It produces three important indices: ejection duration index (ED%), augmentation index adjusted for heart rate (AIX@75), and subendocardial viability ratio (SEVR%). The aim of this study was to assess within- and between-observer repeatability of these measurements. After resting supine for 15 minutes, 20 ambulant patients (16 male) in sinus rhythm under...

  10. The practice of investment viability appraisal in Akure, Nigeria ...

    African Journals Online (AJOL)

    This paper examines the role played by valuers in choosing the right viability appraisal technique for an investment appraisal. Structured questionnaire was administered on Twenty one (21) registered and practicing Estate Surveying and Valuation firms in Akure out of which fourteen (14) were retrieved and found good for ...

  11. Proof of Economic Viability of Blended Learning Business Models

    Science.gov (United States)

    Druhmann, Carsten; Hohenberg, Gregor

    2014-01-01

    The discussion on economically sustainable business models with respect to information technology is lacking in many aspects of proven approaches. In the following contribution the economic viability is valued based on a procedural model for design and evaluation of e-learning business models in the form of a case study. As a case study object a…

  12. Evaluating the Viability of Mobile Learning to Enhance Management Training

    Science.gov (United States)

    Macdonald, Iain; Chiu, Jason

    2011-01-01

    A qualitative research project was conducted to test the viability of augmenting an e-learning program for workplace learners using mobile content delivered through smart phones. Ten learners taking a six week web-based e-learning course were given smart phones which enabled them to access approximately 70% of the course content, in addition to…

  13. Assessment of viability of microorganisms employing fluorescence techniques

    NARCIS (Netherlands)

    Breeuwer, P.

    1996-01-01


    Viability assessment of microorganisms is relevant for a wide variety of applications in industry, including evaluation of inactivation treatments and quality assessment of starter cultures for beer, wine, and yoghurt production.

    Usually, the ability of microbial cells to

  14. Desiccation-induced changes in viability, lipid peroxidation and ...

    African Journals Online (AJOL)

    Intermediate seeds of Mimusopsis elengi showed obvious membrane lipid peroxidation during desiccation. When the moisture content (MC) decreased from initial 41.8 to 6.1%, seed viability significantly decreased from 100 to 23%, consorted with activity changes of a few anti-oxidative enzymes. The activities of superoxide ...

  15. Banana nectar as a medium for testing pollen viability and ...

    African Journals Online (AJOL)

    Administrator

    2007-05-16

    May 16, 2007 ... A quick and reliable method for evaluating pollen quality is essential in a breeding program, especially in a crop such as banana that is characterized by high male and female sterility. In this study the germination and viability of banana pollen was evaluated in a sucrose solution and diluted banana nectar.

  16. Banana nectar as a medium for testing pollen viability and ...

    African Journals Online (AJOL)

    A quick and reliable method for evaluating pollen quality is essential in a breeding program, especially in a crop such as banana that is characterized by high male and female sterility. In this study the germination and viability of banana pollen was evaluated in a sucrose solution and diluted banana nectar. Twenty banana ...

  17. Morphology and viability of castor bean genotypes pollen grains

    Directory of Open Access Journals (Sweden)

    Maria Selma Alves Silva Diamantino

    2016-01-01

    Full Text Available The objective of this work was to characterize the morphology and viability of the pollen of 15 genotypes of castor bean (Ricinus communis L. and to generate information that can assist in the selection of highly promising male parents for future use in genetic improvement programs aimed at producing seeds for oil extraction. Acetolysis and scanning electron microscopy was used to characterize the morphology of the pollen. The viability of the pollen grains was estimated by in vitro germination and colorimetric analysis (acetocarmine 2% and 2, 3, 5-triphenyltetrazolium chloride 1%. For the in vitro germination, pollen grains were grown in 10 types of solidified culture medium consisting of different concentrations of sucrose, boric acid, calcium nitrate, magnesium sulfate and potassium nitrate. The pollen grains had the following characteristics: medium size, isopolar and subspheroidal shape, radial symmetry, circular ambit, 3-colporate, elongated endoapertures, tectate exine and granulated sexine. The acetocarmine dye overestimated pollen viability. The media M5 and M8 were the most efficient at promoting the germination of pollen grains. The studied genotypes had high levels of viability and can therefore be used as male parents in genetic improvement programs.

  18. Low-dose adenosine stress echocardiography: Detection of myocardial viability

    Directory of Open Access Journals (Sweden)

    Nedeljkovic Milan

    2003-06-01

    Full Text Available Abstract Objective The aim of this study was to evaluate the diagnostic potential of low-dose adenosine stress echocardiography in detection of myocardial viability. Background Vasodilation through low dose dipyridamole infusion may recruit contractile reserve by increasing coronary flow or by increasing levels of endogenous adenosine. Methods Forty-three patients with resting dyssynergy, due to previous myocardial infarction, underwent low-dose adenosine (80, 100, 110 mcg/kg/min in 3 minutes intervals echocardiography test. Gold standard for myocardial viability was improvement in systolic thickening of dyssinergic segments of ≥ 1 grade at follow-up. Coronary angiography was done in 41 pts. Twenty-seven patients were revascularized and 16 were medically treated. Echocardiographic follow up data (12 ± 2 months were available in 24 revascularized patients. Results Wall motion score index improved from rest 1.55 ± 0.30 to 1.33 ± 0.26 at low-dose adenosine (p Conclusion Low-dose adenosine stress echocardiography test has high diagnostic potential for detection of myocardial viability in the group of patients with left ventricle dysfunction due to previous myocardial infarction. Low dose adenosine stress echocardiography may be adequate alternative to low-dose dobutamine test for evaluation of myocardial viability.

  19. The effects of storage conditions on the viability of ...

    African Journals Online (AJOL)

    Long-terms recoverability of enteropathogens is necessary for future epidemiological studies to screen stool samples when conditions do not permit immediate processing. The aim of this study was to determine the viability and the recoverability of three enteropathogens bacteria (Yersinia enterocolitica, Vibrio cholerae O: 1 ...

  20. The viability of business data mining in the sports environment ...

    African Journals Online (AJOL)

    Data mining can be viewed as the process of extracting previously unknown information from large databases and utilising this information to make crucial business decisions (Simoudis, 1996: 26). This paper considers the viability of using data mining tools and techniques in sports, particularly with regard to mining the ...

  1. Influence of gamma irradiation on pollen viability, germination ability ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... Effects of gamma radiation on vitality and competitive ability of Cucumis pollen. Euphytica, 32: 677-684. Yanmaz R, Ellialtıoglu S, Taner KY (1999). The effects of gamma irradiation on pollen viability and haploid plant formation in snake cucumber (Cucumis melo L. var. flexuosus Naud.). Acta Hort. 492:.

  2. Low-level waste vitrification contact maintenance viability study

    Energy Technology Data Exchange (ETDEWEB)

    Leach, C.E., Westinghouse Hanford

    1996-07-12

    This study investigates the economic viability of contact maintenance in the Low-Level Waste Vitrification Facility, which is part of the Hanford Site Tank Waste Remediation System. This document was prepared by Flour Daniel, Inc., and transmitted to Westinghouse Hanford Company in September 1995.

  3. Pollen diversity, viability and floral structure of some Musa genotypes

    African Journals Online (AJOL)

    This experiment was designed to study the floral structure, pollen morphology and the potential pollen viability of five Musa genotypes obtained from the Musa field ... Three different types of pollen were encountered viz, big, moderate and small pollens with corresponding big, moderate and small apertures and pores.

  4. Viability of bull semen extended with commercial semen extender ...

    African Journals Online (AJOL)

    Andrea Raseona

    Abstract. The aim of this study was to evaluate the viability of bull spermatozoa diluted with commercial semen extender and two culture media stored at controlled room temperature (24 °C) for 72 hours. Two Nguni bulls were used for semen collection with the aid of an electro-ejaculator. After macroscopic evaluation ...

  5. The economic and social viability of Tanzanian Wildlife Management Areas

    DEFF Research Database (Denmark)

    Homewood, Katherine; Bluwstein, Jevgeniy; Lund, Jens Friis

    This policy brief contributes to assessing the economic and social viability of Tanzania’s Wildlife Management Areas (WMAs) through preliminary findings by the ‘Poverty and ecosystem Impacts of Tanzania’s Wildlife Management Areas’ (PIMA) project, focusing on benefits, costs, and their distribution...

  6. Effect of pretreatments on seed viability during fruit development of ...

    African Journals Online (AJOL)

    Studies to identify the stage at which developing fruits of Irvingia gabonensis (var. excelsa and var. gabonensis), picked from standing trees and/or forest floors, attain maximum viability and germinability were conducted in two harvesting seasons in 2000 and 2001. Some pretreatment methods were used as a means of ...

  7. Viability of bull semen extended with commercial semen extender ...

    African Journals Online (AJOL)

    After macroscopic evaluation, semen was pooled and aliquoted randomly into Triladyl, modified Ham's F10, and TCM-199 culture media, and then stored at 24 °C. Sperm motility parameters, morphology, and viability were analysed with computer aided sperm analysis (CASA) after 0, 24, 48 and 72 hours. The study was ...

  8. A comparison of assays measuring the viability of Legionella ...

    Science.gov (United States)

    Background: The relatively high prevalence of Legionella pneumophila in premise plumbing systems has been widely reported. Published reports indicate Legionella has a comparatively high resistance to chlorine and moreover has the ability to grow in phagocytic amoeba which could provide additional protection in chlorinated drinking water distribution systems. Copper-Silver (Cu-Ag) ionization treatment systems are commercially available for use in large building water systems to help control the risks from Legionella bacteria. The objectives of this study were to develop and optimize Legionella viability assays and use them to investigate the viability of Legionella bacteria after exposure to water treated with coppper and silver ions. Methods: Log phase L. pneumophila cells were used in all experiments and were generated by incubation at 35C for 48 hours in buffered yeast extract broth. Viability assays used included plating on buffered charcoal yeast extract agar to determine the number of culturable cells and treating cells with propidium monoazide (PMA) or ethidium monoazide (EMA) followed by quantitative PCR targeting mip gene of L. pneumophila. The qPCR viability assays were optimized using L. pneumophila inactivated by heat treatment at 65C for 60 min. The effectiveness of Cu-Ag ionization treatment was studied by inoculating L. pneumonia at 105 CFU/mL in water collected directly from a building water system that employed this technology and incubat

  9. Effect of salt hyperosmotic stress on yeast cell viability

    Directory of Open Access Journals (Sweden)

    Logothetis Stelios

    2007-01-01

    Full Text Available During fermentation for ethanol production, yeasts are subjected to different kinds of physico-chemical stresses such as: initially high sugar concentration and low temperature; and later, increased ethanol concentrations. Such conditions trigger a series of biological responses in an effort to maintain cell cycle progress and yeast cell viability. Regarding osmostress, many studies have been focused on transcriptional activation and gene expression in laboratory strains of Saccharomyces cerevisiae. The overall aim of this present work was to further our understanding of wine yeast performance during fermentations under osmotic stress conditions. Specifically, the research work focused on the evaluation of NaCl-induced stress responses of an industrial wine yeast strain S. cerevisiae (VIN 13, particularly with regard to yeast cell growth and viability. The hypothesis was that osmostress conditions energized specific genes to enable yeast cells to survive under stressful conditions. Experiments were designed by pretreating cells with different sodium chloride concentrations (NaCl: 4%, 6% and 10% w/v growing in defined media containing D-glucose and evaluating the impact of this on yeast growth and viability. Subsequent fermentation cycles took place with increasing concentrations of D-glucose (20%, 30%, 40% w/v using salt-adapted cells as inocula. We present evidence that osmostress induced by mild salt pre-treatments resulted in beneficial influences on both cell viability and fermentation performance of an industrial wine yeast strain.

  10. Potential carbon credit and community expectations towards viability ...

    African Journals Online (AJOL)

    The paper presents results of the potential carbon credit and community expectations towards viability of REDD+ projects in Ugalla- Masito ecosystem using a case of Ilagala and Karago villages whereby REDD+ is being piloted. Various data collection methods were employed and these included focused group discussion, ...

  11. Research Note on viability of herbicide and Hormone - treated ...

    African Journals Online (AJOL)

    The responses and viability of acid scarified seeds of four tropical weeds to gibberellic acid and seven herbicides including Galex, Gramoxone, 2 - 4 D, Atrazine, Simazine, Roundup and Primextra in the Laboratory were investigated. The weeds used are Cassia occidentalis, Cassia obtusifolia Cassia hirtusa and ...

  12. Economic Viability of Deficit Irrigation in the Western US

    Science.gov (United States)

    In many arid regions of the world, population growth, groundwater depletion, and uncertain supplies have caused agricultural water to become increasingly scarce. Deficit irrigation (DI) provides a potential response to water scarcity, but no consensus exists on its economic viability. In this pape...

  13. Port viability for choice making among shipping companies in West ...

    African Journals Online (AJOL)

    In this paper, the study of port viability for choice making among shipping companies in West Africa sub-region trade route was conducted. Discriminant analysis was used to ascertain the consistency of the attributes of ports that establish their overall attractiveness to the carriers. The critical valued port attributes deduced ...

  14. The effects of storage conditions on the viability of ...

    African Journals Online (AJOL)

    SARAKA DANIEL

    2015-01-07

    Jan 7, 2015 ... Long-terms recoverability of enteropathogens is necessary for future epidemiological studies to screen stool samples when conditions do not permit immediate processing. The aim of this study was to determine the viability and the recoverability of three enteropathogens bacteria (Yersinia enterocolitica,.

  15. Relationships between cock semen viability and the fertility of ...

    African Journals Online (AJOL)

    CUT User

    Semen was collected from each cock following 5ASM, evaluated for semen viability and 0.05 mL diluted semen used to inseminate five hens per breed, in each experimental group. Significant differences in ejaculation rates and semen quality and quantity were recorded in the four breeds of cocks - with the HP cocks of the ...

  16. Optimizing cell viability in droplet-based cell deposition

    NARCIS (Netherlands)

    Hendriks, Jan; Willem Visser, Claas; Henke, Sieger; Leijten, Jeroen; Saris, Daniël B F|info:eu-repo/dai/nl/241604443; Sun, Chao; Lohse, Detlef; Karperien, Marcel

    2015-01-01

    Biofabrication commonly involves the use of liquid droplets to transport cells to the printed structure. However, the viability of the cells after impact is poorly controlled and understood, hampering applications including cell spraying, inkjet bioprinting, and laser-assisted cell transfer. Here,

  17. Interactions between Plant Extracts and Cell Viability Indicators ...

    African Journals Online (AJOL)

    Interactions between Plant Extracts and Cell Viability. Indicators during Cytotoxicity Testing: Implications for. Ethnopharmacological Studies. Sze Mun Chan1, Kong Soo Khoo2 and Nam Weng Sit1*. 1Department of Biomedical Science, 2Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman,.

  18. Dormancy, activation and viability of Rhizopus oligosporus sporangiospores

    NARCIS (Netherlands)

    Thanh, N.V.; Nout, M.J.R.

    2004-01-01

    Interruption of dormancy to improve viability of Rhizopus oligosporus sporangiospores is crucial for the application of stored starter cultures for fungal (tempe) production. We aimed to assess the extent of dormancy and factors that could result in activation. Whereas heat treatments were

  19. Influence of gamma irradiation on pollen viability, germination ability ...

    African Journals Online (AJOL)

    July 9th, 11th, 15th, 21st and 28th) and pollen age (0th and 1st days) on the pollen viability, germination ability and fruit and seed-set were investigated in pumpkin (Cucurbita moschata Duchesne ex Poir.) and winter squash (Cucurbita maxima ...

  20. Crioablação subendocárdica interpapilar (CSIP para o tratamento da taquicardia ventricular recorrente chagásica (TVR Interpapillary subendocardial cryoablation for the treatment of recurrent ventricular chagasic tachicardia

    Directory of Open Access Journals (Sweden)

    Miguel Barbero-Marcial

    1993-09-01

    Full Text Available Uma nova técnica, a crioablação subendocárdica interpapilar (CSIP, foi empregada em 9 pacientes portadores de taquicardia ventricular recorrente chagásica (TVRCh. O local da TVRCh foi determinado pré-operatoriamente através do mapeamento eletrofisiológico (EEP. Em 8 pacientes encontravase na parede lateral do ventrículo esquerdo (VE na região interpapilar (IP e em 1 na face diafragmática do VE com extensão IP. A operação constituiu na abordagem direta da região IP, eliminando-a, após ventriculotomia, com CSIP. Não foi usado TEF intra-operatório. Em 8 dos 9 pacientes no TEF não pode ser desencadeada a TVRCh. Em 1 paciente, foi desencadeada, em uma única oportunidade; este paciente está assintomático 21 meses após a operação, sem crises de TVRCh. Sete pacientes estão assintomáticos, sem medicação antiarrítmica e em classe funcional I. Uma paciente com miocardiopatia difusa encontra-se em CF II com medicação cardiotônica exclusivamente. Os resultados obtidos permitem acreditar na validade da técnica cirúrgica proposta.A new technique - interpapillary subendocardial cryoablation (CSIP - was used in nine patients suffering from recurrent ventricular tachycardia associated with Chagas disease (TVRCh. Location of the TVRCh was determined preoperatively through electrophysiological imaging (EEF. In eight patients it was located on the lateral wall of the left ventricle (VE in the interpapillary region (IP, and in one patient on the diaphragmatic surface of the VE with IP extension. The surgery consisted in a direct approach to the IP region, which was removed following ventriculotomy with CSIP. Intraoperative EEF was not used. TVRCh could not be relieved in eight of the nine patients on EEF. In one patient it was relieved in one attempt only, the patient being asymptomatic 21 months following surgery, with no TVRCh crises. Seven patients are asymptomatic, without anti-arrhythmic medication and in functional class I

  1. Study of Viability of Phosphate Solubilizing Bacteria in Phosphate granules

    Directory of Open Access Journals (Sweden)

    hajar rajabi

    2017-06-01

    average logarithm of population of bacteria in the granules indicated the highest proportion in the granules on the first day and the lowest population on 120 days (4 months, andthe ratio of 1: 1 inoculant and molasses had the largest population than the 2:1. The highest population was observed in 1:1 dried granules at 28 °C, but, some of 1:1 dried granules at 40 °C were consistent with the defined standards. Overall, bacteria I2-4, Z4 and C5-1 showed the greatest amount of population and the population had more power to maintain the standards among the isolates. The granules produced according to the defined standard (two-month period, 105 cell per gram of fertilizer are dried at 28 °C in both 1: 1 and 2: 1 to the end of 4 months in the standard population. Granules dried at 40 °C for 1: 1 ratio of the population by the end of 4 months in the standard range. In the case of the most isolated granules at the ratio of 2:1 until the end of the second month, the population were within the standard range but at the end of the third month, they come lower than standard except I2-4, Z4 and C5-1. The total population of the granules was as following: Granules 1: 1, 28 °C> 2: 1, 28 °C> 1: 1, 40 °C> 2: 1, 40 °C. Considering to the fact that this standard is undefined for four months, but in this study, the population was 104 granules in the fourth month. Conclusion: Based on the results, some of these conditions could keep their population and population decline was less. In general, it can be concluded that the granular organic fertilizer phosphorus in the industry of phosphate solubilizing bacteria with sugar beet molasses as a binder and drying at 40 °C can be used The results were positive and the granules can be cited to the production of this type of microbial fertilizer. Considering to the results, it was found that the proportion of molasses and inoculant, drying temperature and storage time were effective on viability of bacteria. Also, instead of using a train of

  2. Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Coenen, Adriaan; Lubbers, Marisa M.; Dedic, Admir; Chelu, Raluca G.; Geuns, Robert-Jan M. van; Nieman, Koen [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus University Medical Center, Department of Cardiology, Rotterdam (Netherlands); Kurata, Akira; Kono, Atsushi; Dijkshoorn, Marcel L. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Rossi, Alexia [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Barts Health NHS Trust, NIHR Cardiovascular Biomedical Research Unit at Barts, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Department of Cardiology, London (United Kingdom)

    2017-06-15

    To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Subjects with suspected or known coronary artery disease were prospectively included and underwent a CT-MPI examination. From the CT-MPI time-point data absolute myocardial blood flow (MBF) values were temporally resolved using a hybrid deconvolution model. An absolute MBF value was measured in the suspected perfusion defect. TPR was defined as the ratio between the subendocardial and subepicardial MBF. TPR and MBF results were compared with invasive FFR using a threshold of 0.80. Forty-three patients and 94 territories were analysed. The area under the receiver operator curve was larger for MBF (0.78) compared with TPR (0.65, P = 0.026). No significant differences were found in diagnostic classification between MBF and TPR with a territory-based accuracy of 77 % (67-86 %) for MBF compared with 70 % (60-81 %) for TPR. Combined MBF and TPR classification did not improve the diagnostic classification. Dynamic CT-MPI-based transmural perfusion ratio predicts haemodynamically significant coronary artery disease. However, diagnostic performance of dynamic CT-MPI-derived TPR is inferior to quantified MBF and has limited incremental value. (orig.)

  3. Imaging of tumor viability in lung cancer. Initial results using {sup 23}Na-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Henzler, T.; Apfaltrer, P.; Haneder, S.; Schoenberg, S.O.; Fink, C. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Inst. of Clinical Radiology and Nuclear Medicine; Konstandin, S.; Schad, L. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Schmid-Bindert, G.; Manegold, C. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Interdisciplinary Thoracic Oncology; Wenz, F. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Dept. of Radiation Oncology

    2012-04-15

    {sup 23}Na-MRI has been proposed as a potential imaging biomarker for the assessment of tumor viability and the evaluation of therapy response but has not yet been evaluated in patients with lung cancer. We aimed to assess the feasibility of {sup 23}Na-MRI in patients with lung cancer. Three patients with stage IV adenocarcinoma of the lung were examined on a clinical 3 Tesla MRI system (Magnetom TimTrio, Siemens Healthcare, Erlangen, Germany). Feasibility of {sup 23}Na-MRI images was proven by comparison and fusion of {sup 23}Na-MRI with {sup 1}H-MR, CT and FDG-PET-CT images. {sup 23}Na signal intensities (SI) of tumor and cerebrospinal fluid (CSF) of the spinal canal were measured and the SI ratio in tumor and CSF was calculated. One chemonaive patient was examined before and after the initiation of combination therapy (Carboplatin, Gemcitabin, Cetuximab). All {sup 23}Na-MRI examinations were successfully completed and were of diagnostic quality. Fusion of {sup 23}Na-MRI images with {sup 1}H-MRI, CT and FDG-PET-CT was feasible in all patients and showed differences in solid and necrotic tumor areas. The mean tumor SI and the tumor/CSF SI ratio were 13.3 {+-} 1.8 x 103 and 0.83 {+-} 0.14, respectively. In necrotic tumors, as suggested by central non-FDG-avid areas, the mean tumor SI and the tumor/CSF ratio were 19.4 x 103 and 1.10, respectively. {sup 23}Na-MRI is feasible in patients with lung cancer and could provide valuable functional molecular information regarding tumor viability, and potentially treatment response. (orig.)

  4. Delayed enhancement imaging of myocardial viability: low-dose high-pitch CT versus MRI

    Energy Technology Data Exchange (ETDEWEB)

    Goetti, Robert; Feuchtner, Gudrun; Stolzmann, Paul; Donati, Olivio F.; Frauenfelder, Thomas; Leschka, Sebastian; Alkadhi, Hatem [University Hospital Zurich, Department of Radiology, Zurich (Switzerland); Wieser, Monika; Plass, Andre [University Hospital Zurich, Division of Cardiac and Vascular Surgery, Zurich (Switzerland)

    2011-10-15

    To evaluate the accuracy of high-pitch delayed enhancement (DE) CT for the assessment of myocardial viability with MRI as the reference standard. Twenty-four patients (mean age 66.9 {+-} 9.2 years) with coronary artery disease underwent DE imaging with 128-slice dual-source CT (prospective electrocardiography (ECG)-triggering) and MRI at 1.5 T. Two observers assessed DE transmurality per segment, and measured signal intensity (MRI) or attenuation (CT) in infarcted and healthy myocardium and noise in the left ventricular blood pool for calculating contrast-to-noise ratios (CNR). 75/408 (18.4%) segments in 18/24 patients (75.0%) showed DE in MRI, of which 28 segments in 10/24 (41.7%) patients were non-viable (scar tissue transmurality >50%). Sensitivity, specificity and accuracy of CT for diagnosis of non-viability were 60.7%, 96.8% and 94.4% per segment, and 90.0%, 92.9% and 91.7% per patient. CNR was significantly higher in MR (7.4 {+-} 3.0 vs. 4.6 {+-} 1.5; p = 0.018), and image noise significantly lower (11.6 {+-} 5.7 vs.15.0 {+-} 4.5; p = 0.019). Radiation dose of DECT was 0.89 {+-} 0.07 mSv. CTDE imaging in the high-pitch mode enables myocardial viability assessment at a low radiation dose and good accuracy compared with MR, although associated with a lower CNR and higher noise. (orig.)

  5. Is there a viability-vulnerability tradeoff? Sex differences in fetal programming.

    Science.gov (United States)

    Sandman, Curt A; Glynn, Laura M; Davis, Elysia Poggi

    2013-10-01

    In this paper we evaluate the evidence for sex differences in fetal programming within the context of the proposed viability-vulnerability tradeoff. We briefly review the literature on the factors contributing to primary and secondary sex ratios. Sex differences in fetal programming are assessed by summarizing previously published sex difference findings from our group (6 studies) and also new analyses of previously published findings in which sex differences were not reported (6 studies). The review and reanalysis of studies from our group are consistent with the overwhelming evidence of increasing risk for viability among males exposed to environmental adversity early in life. New evidence reported here support the argument that females, despite their adaptive agility, also are influenced by exposure to early adversity. Two primary conclusions are (i) female fetal exposure to psychobiological stress selectively influences fear/anxiety, and (ii) the effects of female fetal exposure to stress persist into preadolescence. These persisting effects are reflected in increased levels of anxiety, impaired executive function and neurological markers associated with these behaviors. A tacit assumption is that females, with their adaptive flexibility early in gestation, escape the consequences of early life exposure to adversity. We argue that the consequences of male exposure to early adversity threaten their viability, effectively culling the weak and the frail and creating a surviving cohort of the fittest. Females adjust to early adversity with a variety of strategies, but their escape from the risk of early mortality and morbidity has a price of increased vulnerability expressed later in development. © 2013.

  6. Influence of repeated aspiration on viability of fat grafts: a comparative study.

    Science.gov (United States)

    Wang, Rongrong; Sun, Jiaming; Xiong, Lingyun; Yang, Jie

    2015-11-01

    Fat grafting has been increasingly widely used in cosmetic and reconstructive surgery. However, the long-term retention of fat grafts is still unpredictable. Many critical variables have been found to significantly affect the viability of fat grafts; still, some of the ordinary impact factors are overlooked. We performed this study to find out whether repeated aspiration had an impact on fat grafts through an in vitro analysis and a nude mouse model. A 15 cm by 10 cm rectangle was marked at the lower abdomen. The cannula was gently advanced and retracted through the same incision in a fan fashion within the superficial layer to collect fat samples. Based on the sequence of harvesting, the collected adipose tissue was divided into five groups and labeled as syringes 1, 2, 3, 4, and 5. Part of the sample was dissociated and analyzed using cell staining, Cell Counting Kit-8 assay, and flow cytometry. The other part was injected in vivo and analyzed for weight and histology at varying time intervals. Fat grafts from the former syringes were presented with a greater number of viable adipocytes and a higher level of cellular function compared to the latter syringes. Additionally, fat grafts from former syringes had higher graft retention, better vascularity, and less cystic necrosis. Neither the viability of stromal vascular fractions (SVFs) nor the ratio of CD34 + CD45- cells within the SVFs were different among the five groups. Repeated aspiration had a negative impact on the adipocytes, but not on the SVFs. With an increasing time of aspiration, the viability of the adipocytes and long-term retention of fat grafts decreased gradually. Harvested fat grafts from the first few syringes may be more suitable for fat grafting. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  7. Fetal viability as a threshold to personhood. A legal analysis.

    Science.gov (United States)

    Peterfy, A

    1995-12-01

    This essay opens with an examination of US laws concerning fetal viability as they apply to induced abortion, to a mother's right to refuse medical treatment necessary to save the life of a fetus, and to the rights to file suit for the wrongful death of unborn children. The history of abortion policies in the US is traced from the common law period of the early 19th century to the restrictive post-Civil War laws and the decisions of the Supreme Court in Roe vs. Wade, which upheld the constitutionality of previability abortions; Webster vs. Reproductive Health Services, in which the Court assigned viability to the 20th week of pregnancy and acknowledged that States could have a compelling previability interest in the fetus; and the Casey decision, which provided tolerance for limits on the availability of abortion before viability as long as the limits did not create an "undue burden" on the woman seeking the abortion. Courts dealing with the issue of compelling a mother to undergo medical treatment to save her fetus have been inconsistent as they balanced the state's interest in the fetus against the mother's rights to privacy. Judges have tended to err on the side of forcing the medical interventions, but the most recent trend is against this sort of judgement. In these cases, fetal viability has also served as a dividing line. The inconsistency of the legal system is illustrated by the fact that, whereas the fetus now has a legal existence, wrongful death actions entered on behalf of a nonviable fetus have often been denied although courts have been more willing to extend protection to fetuses in wrongful death tort cases than in abortion or medical intervention cases. Criminal law has a unique set of rules for dealing with fetuses as some states have broadened their definitions of "homicide" to include fetuses, even nonviable fetuses. Courts, however, are reluctant to enlarge criminal statutes on their own. While the central position given to the role of

  8. Fungal Spores Viability on the International Space Station

    Science.gov (United States)

    Gomoiu, I.; Chatzitheodoridis, E.; Vadrucci, S.; Walther, I.; Cojoc, R.

    2016-11-01

    In this study we investigated the security of a spaceflight experiment from two points of view: spreading of dried fungal spores placed on the different wafers and their viability during short and long term missions on the International Space Station (ISS). Microscopic characteristics of spores from dried spores samples were investigated, as well as the morphology of the colonies obtained from spores that survived during mission. The selected fungal species were: Aspergillus niger, Cladosporium herbarum, Ulocladium chartarum, and Basipetospora halophila. They have been chosen mainly based on their involvement in the biodeterioration of different substrate in the ISS as well as their presence as possible contaminants of the ISS. From biological point of view, three of the selected species are black fungi, with high melanin content and therefore highly resistant to space radiation. The visual inspection and analysis of the images taken before and after the short and the long term experiments have shown that all biocontainers were returned to Earth without damages. Microscope images of the lids of the culture plates revealed that the spores of all species were actually not detached from the surface of the wafers and did not contaminate the lids. From the adhesion point of view all types of wafers can be used in space experiments, with a special comment on the viability in the particular case of iron wafers when used for spores that belong to B. halophila (halophilic strain). This is encouraging in performing experiments with fungi without risking contamination. The spore viability was lower in the experiment for long time to ISS conditions than that of the short experiment. From the observations, it is suggested that the environment of the enclosed biocontainer, as well as the species'specific behaviour have an important effect, reducing the viability in time. Even the spores were not detached from the surface of the wafers, it was observed that spores used in the

  9. Business sustainability performance measurement: Eco-ratio analysis

    Directory of Open Access Journals (Sweden)

    Collins C. Ngwakwe

    2016-12-01

    Full Text Available Eco-aware customers and stakeholders are demanding for a measurement that links environmental performance with other business operations. To bridge this seemingly measurement gap, this paper suggests ‘Eco-Ratio Analysis’ and proposes an approach for conducting eco-ratio analysis. It is argued that since accounting ratios function as a tool for evaluating corporate financial viability by management and investors, eco-ratio analysis should be brought to the fore to provide a succinct measurement about the linkage between environmental performance and conventional business performance. It is hoped that this suggestion will usher in a nuance debate and approach in the teaching, research and practice of environmental management and sustainability accounting

  10. Tau hadronic branching ratios

    CERN Document Server

    Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    From 64492 selected \\tau-pair events, produced at the Z^0 resonance, the measurement of the tau decays into hadrons from a global analysis using 1991, 1992 and 1993 ALEPH data is presented. Special emphasis is given to the reconstruction of photons and \\pi^0's, and the removal of fake photons. A detailed study of the systematics entering the \\pi^0 reconstruction is also given. A complete and consistent set of tau hadronic branching ratios is presented for 18 exclusive modes. Most measurements are more precise than the present world average. The new level of precision reached allows a stringent test of \\tau-\\mu universality in hadronic decays, g_\\tau/g_\\mu \\ = \\ 1.0013 \\ \\pm \\ 0.0095, and the first measurement of the vector and axial-vector contributions to the non-strange hadronic \\tau decay width: R_{\\tau ,V} \\ = \\ 1.788 \\ \\pm \\ 0.025 and R_{\\tau ,A} \\ = \\ 1.694 \\ \\pm \\ 0.027. The ratio (R_{\\tau ,V} - R_{\\tau ,A}) / (R_{\\tau ,V} + R_{\\tau ,A}), equal to (2.7 \\pm 1.3) \\ \\%, is a measure of the importance of Q...

  11. Potential support ratios

    DEFF Research Database (Denmark)

    Kjærgaard, Søren; Canudas-Romo, Vladimir

    2017-01-01

    The ‘prospective potential support ratio’ has been proposed by researchers as a measure that accurately quantifies the burden of ageing, by identifying the fraction of a population that has passed a certain measure of longevity, for example, 17 years of life expectancy. Nevertheless, the prospect......The ‘prospective potential support ratio’ has been proposed by researchers as a measure that accurately quantifies the burden of ageing, by identifying the fraction of a population that has passed a certain measure of longevity, for example, 17 years of life expectancy. Nevertheless......, the prospective potential support ratio usually focuses on the current mortality schedule, or period life expectancy. Instead, in this paper we look at the actual mortality experienced by cohorts in a population, using cohort life tables. We analyse differences between the two perspectives using mortality models......, historical data, and forecasted data. Cohort life expectancy takes future mortality improvements into account, unlike period life expectancy, leading to a higher prospective potential support ratio. Our results indicate that using cohort instead of period life expectancy returns around 0.5 extra younger...

  12. Economic viability of the piauçu Leporinus macrocephalus (Garavello & Britski, 1988 production

    Directory of Open Access Journals (Sweden)

    Takahashi Leonardo Susumu

    2004-01-01

    Full Text Available Brazilian fish farms presented an accelerated development during the early 90's, mainly because of the increase in fee-fishing operations. To meet the demand of this market, fish production and supply became excessive and, as a consequence, the number of fee-fishing operations, farmers and the final selling price, decreased. This study analyzes the technical aspects, production cost, profitability and economic viability of the production of piauçu (L. macrocephalus in ponds, based on information from a rural property. Feeding and fingerling costs amount to approximately 47.1% of the total production cost, representing together with the final selling price the most important factor affecting profitability. The payback period was 8.3 years, the liquid present value US$ 291.07, the internal return margin 9%, and the income-outcome ratio was 1.01, which represents an unattractive investment as a projection based on current conditions. The improvement in productive efficiency enhances the economic valuation index, and that the relative magnitude of cost and income are the most important points for the economic viability of the studied farm.

  13. VIABILITY OF THE PROBIOTIC BACTERIA L. ACIDOPHILUS IN DAIRY PRODUCTS

    Directory of Open Access Journals (Sweden)

    Janka Koreňová

    2011-12-01

    Full Text Available A number of health benefits have been claimed for probiotic bacteria such as Lactobacillus acidophilus. Because of the potential health benefits, these organisms are increasingly incorporated into dairy foods. Viability of probiotic bacteria is important in order to provide health benefits. However, many studies have shown low viability of probiotics in market preparations. This study cover selective enumeration and survival of probiotic bacteria L. acidophilus in some dairy drinks. L. acidophilus was found in the range from 106 to 107 CFU.g-1 in five types of fermented milk products containing probiotic cultures. Two investigated products were up to standard according to Regulation of Ministry of Agriculture and Ministry of Health of Slovak Republic.doi: 10.5219/147

  14. Nuclear Power Options Viability Study. Volume 4. Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Trauger, D B; White, J D; Sims, J W [eds.

    1986-09-01

    Documents in the Nuclear Power Options Viability Study (NPOVS) bibliography are classified under one of four headings or categories as follows: nuclear options; light water reactors; liquid metal reactors; and high temperature reactors. The collection and selection of these documents, beginning early in 1984 and continuing through March of 1986, was carried out in support of the study's objective: to explore the viabilities of several nuclear electric power generation options for commercial deployment in the United States between 2000 and 2010. There are approximately 550 articles, papers, reports, and books in the bibliography that have been selected from some 2000 surveyed. The citations have been made computer accessible to facilitate rapid on-line retrieval by keyword, author, corporate author, title, journal name, or document number.

  15. Myocardial Viability: From Proof of Concept to Clinical Practice

    Directory of Open Access Journals (Sweden)

    Aditya Bhat

    2016-01-01

    Full Text Available Ischaemic left ventricular (LV dysfunction can arise from myocardial stunning, hibernation, or necrosis. Imaging modalities have become front-line methods in the assessment of viable myocardial tissue, with the aim to stratify patients into optimal treatment pathways. Initial studies, although favorable, lacked sufficient power and sample size to provide conclusive outcomes of viability assessment. Recent trials, including the STICH and HEART studies, have failed to confer prognostic benefits of revascularisation therapy over standard medical management in ischaemic cardiomyopathy. In lieu of these recent findings, assessment of myocardial viability therefore should not be the sole factor for therapy choice. Optimization of medical therapy is paramount, and physicians should feel comfortable in deferring coronary revascularisation in patients with coronary artery disease with reduced LV systolic function. Newer trials are currently underway and will hopefully provide a more complete understanding of the pathos and management of ischaemic cardiomyopathy.

  16. Traffic networks as information systems a viability approach

    CERN Document Server

    Aubin, Jean-Pierre

    2017-01-01

    This authored monograph covers a viability to approach to traffic management by advising to vehicles circulated on the network the velocity they should follow for satisfying global traffic conditions;. It presents an investigation of three structural innovations: The objective is to broadcast at each instant and at each position the advised celerity to vehicles, which could be read by auxiliary speedometers or used by cruise control devices. Namely, 1. Construct regulation feedback providing at each time and position advised velocities (celerities) for minimizing congestion or other requirements. 2. Taking into account traffic constraints of different type, the first one being to remain on the roads, to stop at junctions, etc. 3. Use information provided by the probe vehicles equipped with GPS to the traffic regulator; 4. Use other global traffic measures of vehicles provided by different types of sensors; These results are based on convex analysis, intertemporal optimization and viability theory as mathemati...

  17. Care at the edge of viability: medical and ethical issues.

    Science.gov (United States)

    Haward, Marlyse F; Kirshenbaum, Nancy W; Campbell, Deborah E

    2011-09-01

    Decision-making for extremely immature preterm infants at the margins of viability is ethically, professionally, and emotionally complicated. A standard for prenatal consultation should be developed incorporating assessment of parental decision-making preferences and styles, a communication process involving a reciprocal exchange of information, and effective strategies for decisional deliberation, guided by and consistent with parental moral framework. Professional caregivers providing perinatal consultations or end-of-life counseling for extremely preterm infants should be sensitive to these issues and be taught flexibility in counseling techniques adhering to consistent guidelines. Emphasis must shift away from physician beliefs and behaviors about the boundaries of viability. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Characteristics associated with regional health information organization viability.

    Science.gov (United States)

    Adler-Milstein, Julia; Landefeld, John; Jha, Ashish K

    2010-01-01

    Regional Health Information Organizations (RHIOs) will likely play a key role in our nation's effort to catalyze health information exchange. Yet we know little about why some efforts succeed while others fail. We sought to identify factors associated with RHIO viability. Using data from a national survey of RHIOs that we conducted in mid-2008, we examined factors associated with becoming operational and factors associated with financial viability. We used multivariate logistic regression models to identify unique predictors. We classified RHIOs actively facilitating data exchange as operational and measured financial viability as the percent of operating costs covered by revenue from participants in data exchange (0-24%, 25-74%, 75-100%). Predictors included breadth of participants, breadth of data exchanged, whether the RHIO focused on a specific population, whether RHIO participants had a history of collaborating, and sources of revenue during the planning phase. Exchanging a narrow set of data and involving a broad group of stakeholders were independently associated with a higher likelihood of being operational. Involving hospitals and ambulatory physicians, and securing early funding from participants were associated with a higher likelihood of financial viability, while early grant funding seemed to diminish the likelihood. Finding ways to help RHIOs become operational and self-sustaining will bolster the current approach to nationwide health information exchange. Our work suggests that convening a broad coalition of stakeholders to focus on a narrow set of data is an important step in helping RHIOs become operational. Convincing stakeholders to financially commit early in the process may help RHIOs become self-sustaining.

  19. Effect of Allium sativum (garlic) methanol extract on viability and ...

    African Journals Online (AJOL)

    Effect of Allium sativum (garlic) methanol extract on viability and apoptosis of human leukemic cell lines. ... bromide (MTT) assay at concentrations of 3.125, 6.25, 12.5, 25, 50, 100, 200, 400 and 800 ug/mL of Allium sativum extract following 48-h treatment on U-937, Jurkat Clone E6-1 and K-562 cell lines. The mode of cell ...

  20. Viability and Indication of Pathogenic Microbes in the Environment,

    Science.gov (United States)

    viability of parasitic microbes can be clarified corrently only with consideration of the interaction of the organism with the environment and...adaptation to it. According to this school of thought, the stability of a causative agent in the environment is determined by the specific mechanism through...mechanism of transfer of the contaminating principle, the shorter the period during which the parasitic microbe is in the environment - i.e., the

  1. Effect of Isolation Techniques on Viability of Bovine Blood Neutrophils

    Directory of Open Access Journals (Sweden)

    P. Sláma

    2006-01-01

    Full Text Available The effect of selected isolation methods on the viability of neutrophil granulocytes (neutrophils from the blood of healthy Holstein x Bohemian Red Pied crossbred heifers was evaluated. Two methods of neutrophil isolation were used: a neutrophil isolation on the basis of hypotonic erythrocyte lysis (in two variants: after the erythrocyte lysis proper, the cells were centrifuged at either 200 g or 1000 g, and b neutrophil isolation with FACS Lysing Solution as the lysing agent. The viability of the isolated neutrophils was evaluated on the basis of apoptosis and necrosis. The results obtained with flow cytometry (FCM suggest that, from the isolation techniques used, the method based on FACS Lysing Solution impaired the neutrophil viability least. After the application of this method, 5.36 ± 2.15% of neutrophils were apoptotic and 0.51 ± 0.12% were necrotic. In contrast, when the hypotonic erythrocyte lysis was used, the proportion of apoptotic neutrophils amounted to 42.14 ± 7.12% and 49.00 ± 14.70%, respectively, and 41.12 ± 5.55% and 36.91 ± 24.38% respectively of necrotic neutrophils (P < 0.01. This was also confirmed by the light microscopy. After the isolation with FASC Lysing Solution, 1.92 ± 1.74% of neutrophils were apoptotic and 1.05 ± 0.76% were necrotic, as distinct from after the hypotonic erythrocyte lysis where 9.43 ± 3.69% of neutrophils were apoptotic and 12.67 ± 4.74% of necrotic after centrifugation at 200 g, while 12.60 ± 4.35 were apoptotic and 14.96 ± 12.64% were necrotic after centrifugation at 1000 g. It follows from the above-mentioned data that hypotonic lysis is not a suitable method for the isolation of neutrophils, as the method itself markedly affects cell viability.

  2. Effects of Fluid Shear Stress on Cancer Stem Cell Viability

    Science.gov (United States)

    Sunday, Brittney; Triantafillu, Ursula; Domier, Ria; Kim, Yonghyun

    2014-11-01

    Cancer stem cells (CSCs), which are believed to be the source of tumor formation, are exposed to fluid shear stress as a result of blood flow within the blood vessels. It was theorized that CSCs would be less susceptible to cell death than non-CSCs after both types of cell were exposed to a fluid shear stress, and that higher levels of fluid shear stress would result in lower levels of cell viability for both cell types. To test this hypothesis, U87 glioblastoma cells were cultured adherently (containing smaller populations of CSCs) and spherically (containing larger populations of CSCs). They were exposed to fluid shear stress in a simulated blood flow through a 125-micrometer diameter polyetheretherketone (PEEK) tubing using a syringe pump. After exposure, cell viability data was collected using a BioRad TC20 Automated Cell Counter. Each cell type was tested at three physiological shear stress values: 5, 20, and 60 dynes per centimeter squared. In general, it was found that the CSC-enriched U87 sphere cells had higher cell viability than the CSC-depleted U87 adherent cancer cells. Interestingly, it was also observed that the cell viability was not negatively affected by the higher fluid shear stress values in the tested range. In future follow-up studies, higher shear stresses will be tested. Furthermore, CSCs from different tumor origins (e.g. breast tumor, prostate tumor) will be tested to determine cell-specific shear sensitivity. National Science Foundation Grant #1358991 supported the first author as an REU student.

  3. MODERN TECHNIQUES OF CERVICAL INSTRUMENTATION IN IMMATURE SKELETON: VIABILITY ASSESSMENT

    OpenAIRE

    Aires, Ayrana Soares; Silva, Luís Eduardo Carelli Teixeira da; Barros, Alderico Girão Campos de; Azevedo, Gustavo Borges Laurindo de; Naves, Cleiton Dias

    2017-01-01

    ABSTRACT Objective: This study describes the use of materials for modern cervical instrumentation, evaluating its viability in children and adolescents, and the techniques used in different cases. The efficacy of the techniques was analyzed through improvement of pain, maintenance of cervical range of motion, recovery of craniocervical stability, bone consolidation, and spinal stenosis in the postoperative follow-up. Method: Retrospective study of the clinical and radiological parameters of 2...

  4. Comparison of tissue viability imaging and colorimetry: skin blanching.

    Science.gov (United States)

    Zhai, Hongbo; Chan, Heidi P; Farahmand, Sara; Nilsson, Gert E; Maibach, Howard I

    2009-02-01

    Operator-independent assessment of skin blanching is important in the development and evaluation of topically applied steroids. Spectroscopic instruments based on hand-held probes, however, include elements of operator dependence such as difference in applied pressure and probe misalignment, while laser Doppler-based methods are better suited for demonstration of skin vasodilatation than for vasoconstriction. To demonstrate the potential of the emerging technology of Tissue Viability Imaging (TiVi) in the objective and operator-independent assessment of skin blanching. The WheelsBridge TiVi600 Tissue Viability Imager was used for quantification of human skin blanching with the Minolta chromameter CR 200 as an independent colorimeter reference method. Desoximetasone gel 0.05% was applied topically on the volar side of the forearm under occlusion for 6 h in four healthy adults. In a separate study, the induction of blanching in the occlusion phase was mapped using a transparent occlusion cover. The relative uncertainty in the blanching estimate produced by the Tissue Viability Imager was about 5% and similar to that of the chromameter operated by a single user and taking the a(*) parameter as a measure of blanching. Estimation of skin blanching could also be performed in the presence of a transient paradoxical erythema, using the integrated TiVi software. The successive induction of skin blanching during the occlusion phase could readily be mapped by the Tissue Viability Imager. TiVi seems to be suitable for operator-independent and remote mapping of human skin blanching, eliminating the main disadvantages of methods based on hand-held probes.

  5. Ca-Lignosulphonate and sclerotial viability of Sclerotinia sclerotiorum

    Directory of Open Access Journals (Sweden)

    MATTEO MONTANARI

    2012-01-01

    Full Text Available Lignosulphonates, low cost by-products of the pulping process, have shown suppressive effects against some diseases caused by soil-borne pathogens. In this study, the effect of 1.5% v/v calcium lignosulphonate (Ca-Ls amendment to two commercial potting mixes (peat + coconut fibres; PC; and municipal compost + peat + pumice; MCPP on the viability of Sclerotinia sclerotiorum sclerotia was investigated. Sclerotia were buried in the Ca-Ls amended substrates for 30 days. Non-amended PC and MCPP, sterile sand and sterile PC with and without Ca-Ls were used as controls. The viability of sclerotia recovered from PC and MCPP amended with Ca-Ls was reduced by 50 and 42% respectively compared to control treatments. Ca-Ls amendment decreased sclerotial viability by enhancing the activity of the indigenous mycoparasitic fungi, Fusarium oxysporum, Mucor spp. and Trichoderma spp. The biocontrol ability of Ca-Ls against sclerotia was due to the stimulation of microbial activity and is, therefore, strictly dependent on the microbial composition of the substrate.

  6. Viability studies of optically trapped T-cells

    Science.gov (United States)

    McAlinden, Niall; Glass, David G.; Millington, Owain; Wright, Amanda J.

    2011-10-01

    We present a viability study of optically trapped live T cell hybridomas. T cells form an important part of the adaptive immune response system which is responsible for fighting particular pathogens or diseases. The cells of interest were directly trapped by a laser operating at a wavelength of 1064 nm and their viability measured as a function of time. Cell death was monitored using an inverted fluorescent microscope to observe the uptake by the cell of the fluorescent dye propidium iodide. Studies were undertaken at various laser powers and beam profiles. There is a growing interest in optically trapping immune cells and this is the first study that investigates the viability of a T cell when trapped using a conventional optical trapping system. In such experiments it is crucial that the T cell remains viable and trapping the cell directly means that any artefacts due to a cell-bead interface are removed. Our motivation behind this experiment is to use optical tweezers to gain a greater understanding of the interaction forces between T cells and antigen presenting cells. Measuring these interactions has become important due to recent theories which indicate that the strength of this interaction may underlie the activation of the T-cell and subsequent immune response.

  7. Nuclear cardiac imaging for the assessment of myocardial viability.

    Science.gov (United States)

    Slart, R H J A; Bax, J J; van der Wall, E E; van Veldhuisen, D J; Jager, P L; Dierckx, R A

    2005-11-01

    An important aspect of the diagnostic and prognostic work-up of patients with ischaemic cardiomyopathy is the assessment of myocardial viability. Patients with left ventricular dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischaemia but at the same time benefit most from revascularisation. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy (SPECT), whether using 201thallium, 99mTc-sestamibi, or 99mTc- tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic and perfusion imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularisation. New techniques in the nuclear cardiology field, such as attenuation corrected SPECT, dual isotope simultaneous acquisition (DISA) SPECT and gated FDG PET are promising and will further improve the detection of myocardial viability. Also the combination of multislice computed tomography scanners with PET opens possibilities of adding coronary calcium scoring and noninvasive coronary angiography to myocardial perfusion imaging and quantification.

  8. Different effects of sonoporation on cell morphology and viability

    Directory of Open Access Journals (Sweden)

    Ji-Zhen Zhang

    2012-05-01

    Full Text Available The objective of our study was to investigate changes in cell morphology and viability after sonoporation. Sonoportion was achieved by ultrasound (21 kHz exposure on adherent human prostate cancer DU145 cells in the cell culture dishes with the presence of microbubble contrast agents and calcein (a cell impermeant dye. We investigated changes in cell morphology immediately after sonoporation under scanning electron microscope (SEM and changes in cell viability immediately and 6 h after sonoporation under fluorescence microscope. It was shown that various levels of intracellular calcein uptake and changes in cell morphology can be caused immediately after sonoporation: smooth cell surface, pores in the membrane and irregular cell surface. Immediately after sonoporation, both groups of cells with high levels of calcein uptake and low levels of calcein uptake were viable; 6 h after sonoporation, group of cells with low levels of calcein uptake still remained viable, while group of cells with high levels of calcein uptake died. Sonoporation induces different effects on cell morphology, intracellular calcein uptake and cell viability.

  9. Viability of various weed seeds in anaerobic conditions (biogas plant)

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, S.; Hansen, J.

    1983-04-01

    Seeds from different weeds, Urtica urens L. (nettle), Solanum nigrum L. (nightshade), Avena fatua L. (wild oat-grass), Brassica napus L. (rape), Chenopodium album L. (goose-foot), were put into small polyester net bags, which were placed in biogas reactors containing cattle manure. These ''biogas reactors'' were placed at different temperatures . Net bags were taken out after 4.5, 10.5, 21.5, 38 and 53 days, and the seeds were tested for their viability by germination tests and the tetrazolium method. Concerning all seeds it was manifested that the viability decreased very steeply at 35degC. Most of the seeds had a T/sub 50/ at 2-5 days; Chenopodium album L seeds had a T/sub 50/ at 16 days. After 4.5 days it was not possible to find living Avena fatua L seeds. The decrease in viability was less steep at 20degC and even less steep at 2degC.

  10. Viability of lactobacillus acidophilus in various vaginal tablet formulations

    Directory of Open Access Journals (Sweden)

    Fazeli M.R.

    2006-07-01

    Full Text Available The lactobacilli which are present in vaginal fluids play an important role in prevention of vaginosis and there are considerable interests in formulation of these friendly bacteria into suitable pharmaceutical dosage forms. Formulating these microorganisms for vaginal application is a critical issue as the products should retain viability of lactobacilli during formulation and also storage. The aim of this study was to examine the viability and release of Lactobacillus acidophilus from slow-release vaginal tablets prepared by using six different retarding polymers and from two effervescent tablets prepared by using citric or adipic acid. The Carbomer–based formulations showed high initial viablility compared to those based on HPMC-LV, HPMC-HV, Polycarbophil and SCMC polymers which showed one log decrease in viable cells. All retarding polymers in slow release formulations presented a strong bacterial release at about 2 h except Carbomer polymers which showed to be poor bacterial releasers. Although effervescent formulations produced a quick bacterial release in comparison with polymer based slow-release tablets, they were less stable in cold storage. Due to the strong chelating characteristic of citric acid, the viability was quickly lost for aqueous medium of citric acid in comparison with adipic acid based effervescent tablets.

  11. PET/SPECT imaging: From carotid vulnerability to brain viability

    Energy Technology Data Exchange (ETDEWEB)

    Meerwaldt, Robbert [Department of Surgery, Isala Clinics, Zwolle (Netherlands); Slart, Riemer H.J.A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Dam, Gooitzen M. van [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands); Luijckx, Gert-Jan [Department of Neurology, University Medical Center Groningen, Groningen (Netherlands); Tio, Rene A. [Department of Cardiology, University Medical Center Groningen, Groningen (Netherlands); Zeebregts, Clark J. [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands)], E-mail: czeebregts@hotmail.com

    2010-04-15

    Background: Current key issues in ischemic stroke are related to carotid plaque vulnerability, brain viability, and timing of intervention. The treatment of ischemic stroke has evolved into urgent active interventions, as 'time is brain'. Functional imaging such as positron emission tomography (PET)/single photon emission computed tomography (SPECT) could improve selection of patients with a vulnerable plaque and evaluation of brain viability in ischemic stroke. Objective: To describe the current applications of PET and SPECT as a diagnostic tool in relation to ischemic stroke. Methods: A literature search using PubMed identified articles. Manual cross-referencing was also performed. Results: Several papers, all observational studies, identified PET/SPECT to be used as a tool to monitor systemic atheroma modifying treatment and to select high-risk patients for surgery regardless of the degree of luminal stenosis in carotid lesions. Furthermore, PET/SPECT is able to quantify the penumbra region during ischemic stroke and in this way may identify those patients who may benefit from timely intervention. Discussion: Functional imaging modalities such as PET/SPECT may become important tools for risk-assessment and evaluation of treatment strategies in carotid plaque vulnerability and brain viability. Prospective clinical studies are needed to evaluate the diagnostic accuracy of PET/SPECT.

  12. Dormancy, activation and viability of Rhizopus oligosporus sporangiospores.

    Science.gov (United States)

    Thanh, N V; Nout, M J R

    2004-04-15

    Interruption of dormancy to improve viability of Rhizopus oligosporus sporangiospores is crucial for the application of stored starter cultures for fungal (tempe) production. We aimed to assess the extent of dormancy and factors that could result in activation. Whereas heat treatments were unsuccessful, Malt Extract Broth (MEB) showed to be a good activation medium, with 80% of dormant spores being activated as measured by fluorescence microscopy using a fluorescent marker, compared with 11% with the control. Peptone and yeast extract but not glucose played an important role in activating dormant spores. Metabolically active (fluorescent) and swollen spores, followed by germ tubes were obtained after activation in MEB for 25 min., 2 and 4 h, respectively, at 37 degrees C. Simultaneously, some interesting transitions took place. Dormant spores represent 85-90% of the total spores at harvest and after drying. Their number decreased to 21-32% after activation with MEB with a concomitant increase of metabolically active spores. As a result of storage, some dormancy was lost, yielding an increase of active spores from 11.2% at harvest to 28.8% after 3 months storage. Levels of active spores were well correlated with their viability. By activation of dormant spores, their viability increased; levels of viable and active spores were maximum in 1 month old starter (61.7% and 75.9% of total spores, respectively) but gradually decreased with concomitant increase of the number of dead spores.

  13. Viability And Conidial Production Of Entomopathogenic Fungi Penicillium SP.

    Directory of Open Access Journals (Sweden)

    Nurariaty Agus

    2015-01-01

    Full Text Available Abstract Penicillium sp. order Eurotiales class Eurotiomycetes family Trichocomaceae is one of the entomopathogenic fungi that have the potential to be developed as biological control agent of pests.The study aims to determine the viability and spora production of Entomopathogenic fungi Penicillium sp. Experiments was conducted in Pests Identification and Biological Control laboratory Department of Plant Pest and Disease Faculty of Agriculture Hasanuddin University. The fungus Penicillium sp. cultured in a liquid medium and then added chitin as treatment and others without chitin. The spora viability of fungi was observed on 12th and 24th hours while spora production on 3nd 6th 9th and 12th days after application.The results showed that conidial viability of the fungus Penicillium sp. at 24 hours after application was higher if the medium given chitin than without chitin. The conidial production was higher if given chitin than without chitin. It was highest on 12th day reached 143.4 x 106 conidiaml if media given chitin and on 6th day if without chitin 0.50 x 106 conidiaml.

  14. Cell Viability in Arthroscopic Versus Open Autologous Chondrocyte Implantation.

    Science.gov (United States)

    Biant, Leela C; Simons, Michiel; Gillespie, Trudi; McNicholas, Michael J

    2017-01-01

    Autologous chondrocyte implantation (ACI) is an effective method of repair of articular cartilage defects. It is a 2-stage operation, with the second stage most commonly performed via mini-arthrotomy. Arthroscopic ACI is gaining popularity, as it is less invasive and may accelerate early rehabilitation. However, handling and manipulation of the implant have been shown to cause chondrocyte cell death. To assess the number and viability of cells delivered via an open versus arthroscopic approach in ACI surgery. Controlled laboratory study. Sixteen ACI surgeries were performed on young cadaveric knees by 2 experienced surgeons: 8 via mini-arthrotomy and 8 arthroscopically. Live and dead cells were stained and counted on implants after surgery. The cell number and viability were assessed using confocal laser scanning microscopy. Surgery was timed from knife to skin until the end of cycling the knee 10 times after implantation of the cell-membrane construct. On receipt of cell membranes after transportation from the laboratory, ≥92% of the cells were viable. There were significantly more remaining cells (8.47E+07 arthroscopic vs 1.41E+08 open; P arthroscopic vs 37.34% open; P arthroscopic technique. Open surgery was of a significantly shorter duration (6 vs 32 minutes; P arthroscopic technique. The viability of cells delivered for ACI via an arthroscopic approach was 16 times less than via an open approach. The mini-arthrotomy approach is recommended until long-term clinical comparative data are available.

  15. Population viability impacts of habitat additions and subtractions: A simulation experiment with endangered kangaroo rats

    Science.gov (United States)

    Species viability is influenced by the quality, quantity and configuration of habitat. For species at risk, a principal challenge is to identify landscape configurations that, if realized, would improve a population’s viability or restoration potential. Critical habitat patche...

  16. Viability of Event Management Business in Batangas City, Philippine: Basis for Business Operation Initiatives

    National Research Council Canada - National Science Library

    Jeninah Christia D. Borbon

    2016-01-01

    The research study on Viability of Event Management Business in Batangas City: Basis for Business Operation Initiatives aimed to assess the viability of this type of business using Thompson’s (2005...

  17. Monitoring viability of seeds in gene banks: developing software tools to increase efficiency

    Science.gov (United States)

    Monitoring the decline of seed viability is essential for effective long term seed storage in ex situ collections. Recent FAO Genebank Standards recommend monitoring intervals at one-third the time predicted for viability to fall to 85% of initial viability. This poster outlines the development of ...

  18. Non-disruptive measurement system of cell viability in bioreactors

    Science.gov (United States)

    Rudek, F.; Nelsen, B. L.; Baselt, T.; Berger, T.; Wiele, M.; Prade, I.; Hartmann, P.

    2016-04-01

    Nutrient and oxygen transport, as well as the removal of metabolic waste are essential processes to support and maintain viable tissue. Current bioreactor technology used to grow tissue cultures in vitro has a fundamental limit to the thickness of tissues. Based on the low diffusion limit of oxygen a maximum tissue thickness of 200 μm is possible. The efficiency of those systems is currently under investigation. During the cultivation process of the artificial tissue in bioreactors, which lasts 28 days or longer, there are no possibilities to investigate the viability of cells. This work is designed to determine the influence of a non-disruptive cell viability measuring system on cellular activity. The measuring system uses a natural cellular marker produced during normal metabolic activity. Nicotinamide adenine dinucleotide (NADH) is a coenzyme naturally consumed and produced during cellular metabolic processes and has thoroughly been studied to determine the metabolic state of a cell. Measuring the fluorescence of NADH within the cell represents a non-disruptive marker for cell viability. Since the measurement process is optical in nature, NADH fluorescence also provides a pathway for sampling at different measurement depths within a given tissue sample. The measurement system we are using utilizes a special UV light source, to excite the NADH fluorescence state. However, the high energy potentially alters or harms the cells. To investigate the influence of the excitation signal, the cells were irradiated with a laser operating at a wavelength of 355 nm and examined for cytotoxic effects. The aim of this study was to develop a non-cytotoxic system that is applicable for large-scale operations during drug-tissue interaction testing.

  19. Cost Assessment Methodology and Economic Viability of Tidal Energy Projects

    Directory of Open Access Journals (Sweden)

    Eva Segura

    2017-11-01

    Full Text Available The exploitation of technologies with which to harness the energy from ocean currents will have considerable possibilities in the future thanks to their enormous potential for electricity production and their high predictability. In this respect, the development of methodologies for the economic viability of these technologies is fundamental to the attainment of a consistent quantification of their costs and the discovery of their economic viability, while simultaneously attracting investment in these technologies. This paper presents a methodology with which to determine the economic viability of tidal energy projects, which includes a technical study of the life-cycle costs into which the development of a tidal farm can be decomposed: concept and definition, design and development, manufacturing, installation, operation and maintenance and dismantling. These cost structures are additionally subdivided by considering their sub-costs and bearing in mind the main components of the tidal farm: the nacelle, the supporting tidal energy converter structure and the export power system. Furthermore, a technical study is developed in order to obtain an estimation of the annual energy produced (and, consequently, the incomes generated if the electric tariff is known by considering its principal attributes: the characteristics of the current, the ability of the device to capture energy and its ability to convert and export the energy. The methodology has been applied (together with a sensibility analysis to the particular case of a farm composed of first generation tidal energy converters in one of the Channel Island Races, the Alderney Race, in the U.K., and the results have been attained by means of the computation of engineering indexes, such as the net present value, the internal rate of return, the discounted payback period and the levelized cost of energy, which indicate that the proposed project is economically viable for all the case studies.

  20. Cell structure and percent viability by a slide centrifuge technique.

    Science.gov (United States)

    Fitzgerald, M G; Hosking, C S

    1982-01-01

    It was found that a slide centrifuge (Cytospin) preparation of a cell suspension allowed a reliable assessment of not only cell structure but also the percentage of non-viable cells. The non-viable cells appeared as "smear" cells and paralleled in number the cells taking up trypan blue. Direct experiment showed the unstained viable cells in a trypan blue cell suspension remained intact in a Cytospin preparation while the cells taking up trypan blue were the "smear" cells. The non-viability of the "smear" cells was confirmed by their inability to survive in culture. Images PMID:7040483

  1. Law and ethics at the border of viability.

    Science.gov (United States)

    Krug, E F

    2006-06-01

    The Supreme Court of Texas in the case of Miller v. HCA announced a rule in 2003 (118 s.w. 3d 758) that a physician attending the delivery of a severely premature infant may provide life-sustaining treatment for that infant under 'emergent circumstances' as a matter of law without first obtaining parental consent. This paper examines issues of law and ethics relevant to decisions about infant resuscitation at the border of viability. It is argued that there is typically no emergency when infants are delivered at 23 weeks gestation, and parents should be asked for informed consent before resuscitation in the delivery room.

  2. The Viability of Small Banks in the United States

    OpenAIRE

    R. Alton Gilbert

    2007-01-01

    Small banks have an important role in financing economic activity through their financial services for small businesses. There has been a sharp decline in the number of small banking organizations in the U.S. since the early 1980s. A continuation of this trend would raise important issues about access to financial services for small businesses. Data on the number of banks, their profits, and the distribution of consistent high and low earning banks tend to tell the same story about the viabil...

  3. Methods for isolation and viability assessment of biological organisms

    Science.gov (United States)

    Letant, Sonia Edith; Baker, Sarah Elyse; Bond, Tiziana; Chang, Allan Shih-Ping

    2015-02-03

    Isolation of biological or chemical organisms can be accomplished using a surface enhanced Raman scattering (SERS) system. The SERS system can be a single or a stacked plurality of photonic crystal membranes with noble-metal lined through pores for flowing analyte potentially containing the biological or chemical organisms. The through pores can be adapted to trap individual biological or chemical organisms and emit SERS spectra, which can then be detected by a detector and further analyzed for viability of the biological or chemical organism.

  4. Viability of human corneal keratocytes during organ culture

    DEFF Research Database (Denmark)

    Møller-Pedersen, T; Møller, H J

    1996-01-01

    The viability of human corneal keratocytes was assessed during four weeks of 'closed system' organ culture at 31 degrees C. After 28 days of culturing, the entire keratocyte population was still alive and viable because all cells incorporated uridine; a parameter for RNA-synthesis. During the fir...... of keratan sulphate proteoglycan suggested that approximately 1% of the total content was lost during the period. In conclusion, our current organ culture technique can maintain a viable keratocyte population for four weeks; a viable stroma can be grafted within this period....

  5. Increased viability but decreased culturability of Mycobacterium avium subsp. paratuberculosis in macrophages from inflammatory bowel disease patients under Infliximab treatment.

    Science.gov (United States)

    Nazareth, Nair; Magro, Fernando; Appelberg, Rui; Silva, Jani; Gracio, Daniela; Coelho, Rosa; Cabral, José Miguel; Abreu, Candida; Macedo, Guilherme; Bull, Tim J; Sarmento, Amélia

    2015-12-01

    Mycobacterium avium subsp. paratuberculosis (MAP) has long been implicated as a triggering agent in Crohn's disease (CD). In this study, we investigated the growth/persistence of both M. avium subsp. hominissuis (MAH) and MAP, in macrophages from healthy controls (HC), CD and ulcerative colitis patients. For viability assessment, both CFU counts and a pre16SrRNA RNA/DNA ratio assay (for MAP) were used. Phagolysosome fusion was evaluated by immunofluorescence, through analysis of LAMP-1 colocalization with MAP. IBD macrophages were more permissive to MAP survival than HC macrophages (a finding not evident with MAH), but did not support MAP active growth. The lower MAP CFU counts in macrophage cultures associated with Infliximab treatment were not due to increased killing, but possibly to elevation in the proportion of intracellular dormant non-culturable MAP forms, as MAP showed higher viability in those macrophages. Increased MAP viability was not related to lack of phagolysosome maturation. The predominant induction of MAP dormant forms by Infliximab treatment may explain the lack of MAP reactivation during anti-TNF therapy of CD but does not exclude the possibility of MAP recrudescence after termination of therapy.

  6. Viability and growth promotion of starter and probiotic bacteria in yogurt supplemented with whey protein hydrolysate during refrigerated storage

    Directory of Open Access Journals (Sweden)

    Anna Dąbrowska

    2017-11-01

    Full Text Available The effect of whey protein hydrolysate (WPH addition on growth of standard yoghurt cultures and Bifidobacterium adolescentis during co-fermentation and its viability during storage at 4ºC in yoghurts has been evaluated. WPH was obtained with the use of serine protease from Y. lipolytica yeast. Stirred probiotic yoghurts were prepared by using whole milk standardized to 16% of dry matter with the addition of either whey protein concentrate, skim milk powder (SMP, WPH-SMP (ratio 1:1, WPH. The hydrolysate increased the yoghurt culture counts at the initial stage of fermentation and significantly inhibited the decrease in population viability throughout the storage at 4ºC in comparison to the control. The post-fermentation acidification was also retarded by the addition of WPH. The hydrolysate did not increase the Bifidobacterium adolescentis counts at the initial stage. However, the WPH significantly improved its viability. After 21 days of storage, in the yogurts supplemented with WPH, the population of these bacteria oscillated around 3.04 log10 CFU/g, while in samples where SMP or whey protein concentrate was used, the bacteria were no longer detected.

  7. Cell pairing ratio controlled micro-environment with valve-less electrolytic isolation

    KAUST Repository

    Chen, Yu-Chih

    2012-01-01

    We present a ratio controlled cell-to-cell interaction chip using valve-less isolation. We incorporated electrolysis in a microfluidic channel. In each microfluidic chamber, we loaded two types of different cells at various pairing ratios. More than 80% of the microchambers were successfully loaded with a specific target pairing ratio. For the proof of concept, we have demonstrated the cell-to-cell interaction between prostate cancer cells and muscle stem cells can be controlled by cell pairing ratios through growth factor secretion. The experimental data shows that sealing of microenvironment by air generated from electrolysis does not affect cell viability and cell interaction assay results. © 2012 IEEE.

  8. Resuscitation at the limits of viability--an Irish perspective.

    LENUS (Irish Health Repository)

    Khan, R A

    2012-02-01

    BACKGROUND: Advances in neonatal care continue to lower the limit of viability. Decision making in this grey zone remains a challenging process. OBJECTIVE: To explore the opinions of healthcare providers on resuscitation and outcome in the less than 28-week preterm newborn. DESIGN\\/METHODS: An anonymous postal questionnaire was sent to health care providers working in maternity units in the Republic of Ireland. Questions related to neonatal management of the extreme preterm infant, and estimated survival and long-term outcome. RESULTS: The response rate was 55% (74% obstetricians and 70% neonatologists). Less than 1% would advocate resuscitation at 22 weeks, 10% of health care providers advocate resuscitation at 23 weeks gestation, 80% of all health care providers would resuscitate at 24 weeks gestation. 20% of all health care providers would advocate cessation of resuscitation efforts on 22-25 weeks gestation at 5 min of age. 65% of Neonatologists and 54% trainees in Paediatrics would cease resuscitation at 10 min of age. Obstetricians were more pessimistic about survival and long term outcome in newborns delivered between 23 and 27 weeks when compared with neonatologists. This difference was also observed in trainees in paediatrics and obstetrics. CONCLUSION: Neonatologists, trainees in paediatrics and neonatal nurses are generally more optimistic about outcome than their counterparts in obstetrical care and this is reflected in a greater willingness to provide resuscitation efforts at the limits of viability.

  9. Viability of Hanseniaspora uvarum yeast preserved by lyophilization and cryopreservation.

    Science.gov (United States)

    de Arruda Moura Pietrowski, Giovana; Grochoski, Mayara; Sartori, Gabriela Felkl; Gomes, Tatiane Aparecida; Wosiacki, Gilvan; Nogueira, Alessandro

    2015-08-01

    Hanseniaspora yeasts are known to produce volatile compounds that give fruity aromas in wine and fermented fruit. This study aimed to verify the feasibility of the Hanseniaspora uvarum strain that had been isolated and identified during a previous study and preserved by lyophilization and freezing at -80 °C (cryopreservation). This strain was assessed in relation to its macroscopic and microscopic morphology and for its ability to ferment apple must. After having been subjected to lyophilization and cryopreservation, viability was assessed in relation to these characteristics during 12 months of storage. The strain showed stable colonial features and its microscopic appearance was unchanged during all recoveries. The plate count results showed consistency in both processes. Regarding the fermentative capacity, the kinetic results showed 100% viability for the strain subjected to lyophilization, as well as for those preserved at -80 °C. These results demonstrate that the preservation methods used are compatible with the maintenance of the relevant characteristics of the strain for the period of evaluation of this study (12 months). Copyright © 2015 John Wiley & Sons, Ltd.

  10. Improvement on The Ellis and Roberts Viability Model

    Directory of Open Access Journals (Sweden)

    Guoyan Zhou

    2016-05-01

    Full Text Available With data sets of germination percent and storage time of seed lot of wheat and sorghum stored at three different storage temperature(t, °C with three different water content (m, % of seeds, together with data set of buckwheat and lettuce reported in literatures, the possibility that seed survival curve were transformed into line by survival proportion and the relationship that logarithm of average viability period (logp50 and standard deviation of seed death distribution in time (δwith t, m and interaction between t and m were analysed. Result indicated that survival proportion transformed seed survival curve to line were much easier than the probability adopted by Ellis and Roberts, and the most important factor affecting logp50 and δ of seed lot was interaction between t and m. Thus, Ellis and Roberts viability model were suggested to be improved as Ki=Vi-p/10K-CWT (t×m to predict longevity of seed lot with initial germination percent unknown, a new model of Gi/G0=A-P/10K-CWT(t×m was constructed to predict longevity of seed lot with initial germination percent already known.

  11. A New Methodology for Evaluation of Nematode Viability

    Directory of Open Access Journals (Sweden)

    Sebastião Rodrigo Ferreira

    2015-01-01

    Full Text Available Nematodes infections are responsible for debilitating conditions and economic losses in domestic animals as well as livestock and are considered an important public health problem due to the high prevalence in humans. The nematode resistance for drugs has been reported for livestock, highlighting the importance for development of new anthelmintic compounds. The aim of the current study was to apply and compare fluorimetric techniques using Sytox and propidium iodide for evaluating the viability of C. elegans larvae after treatment with anthelmintic drugs. These fluorescent markers were efficient to stain larvae treated with ivermectin and albendazole sulfoxide. We observed that densitometric values were proportional to the concentration of dead larvae stained with both markers. Furthermore, data on motility test presented an inverse correlation with fluorimetric data when ivermectin was used. Our results showed that lower concentrations of drugs were effective to interfere in the processes of cellular transport while higher drugs concentrations were necessary in order to result in any damage to cell integrity. The methodology described in this work might be useful for studies that aim to evaluate the viability of nematodes, particularly for testing of new anthelminthic compounds using an easy, economic, reproducible, and no time-consuming technique.

  12. Economic viability of cerrado vegetation management under conditions of risk

    Directory of Open Access Journals (Sweden)

    Simão Corrêa da Silva

    2011-06-01

    Full Text Available Cerrado vegetation is Brazil’s second largest biome, comprising about 388 municipalities in Minas Gerais state alone and serving as an important source of natural resources. A large share of the wood charcoal produced in Minas Gerais is sourced from Cerrado vegetation. The objective of this work is to assess the economic viability of Cerrado vegetation management for wood charcoal production, under conditions of risk. The study site is a fragment of Cerrado subjected to five levels of intervention as to basal area removal. For risk analysis, the Monte Carlo method was applied, using charcoal price, interest rate and land value as input variables, and using Net Present Value as output variable over an infinite planning horizon. It was concluded that introducing risk in the economic analysis of the various Cerrado management regimes helped provide additional information to that obtained by deterministic analysis, improving understanding and ensuring safety in decision-making about the economic viability of such regimes. For all treatments, the probability of VPL being negative increases with increasing cutting cycle lengths. For all treatments, the optimal cutting cycle is ten years. Treatments where a larger volume of wood was removed proved less prone to risks of economic inviability since they secure more revenue than treatments where less wood was removed.

  13. Cell viability and angiogenic potential of a bioartificial adipose substitute.

    Science.gov (United States)

    Panneerselvan, Anitha; Nguyen, Luong T H; Su, Yan; Teo, Wee Eong; Liao, Susan; Ramakrishna, Seeram; Chan, Ching Wan

    2015-06-01

    An implantable scaffold pre-seeded with cells needs to remain viable and encourage rapid angiogenesis in order to replace injured tissues, especially for tissue defect repairs. We created a bioartificial adipose graft composed of an electrospun 3D nanofibrous scaffold and fat tissue excised from New Zealand white rabbits. Cell viability and angiogenesis potential of the bioartificial substitute were examined during four weeks of culture in Dulbecco's Modified Eagle Medium by immunohistochemical staining with LIVE/DEAD® cell kit and PECAM-1 antibody, respectively. In addition, a Matrigel® assay was performed to examine the possibility of blood vessels sprouting from the bioartificial graft. Our results showed that cells within the graft were viable and vascular tubes were present at week 4, while cells in a fat tissue block were dead in vitro. In addition, capillaries were observed sprouting from the graft into the Matrigel, demonstrating its angiogenic potential. We expect that improved cell viability and angiogenesis in the bioartificial substitute, compared to intact autologous graft, could potentially contribute to its survival following implantation. Copyright © 2012 John Wiley & Sons, Ltd.

  14. The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

    Science.gov (United States)

    Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

    2011-06-01

    The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

  15. Effect of various commercial buffers on sperm viability and capacitation.

    Science.gov (United States)

    Andrisani, Alessandra; Donà, Gabriella; Ambrosini, Guido; Bonanni, Guglielmo; Bragadin, Marcantonio; Cosmi, Erich; Clari, Giulio; Armanini, Decio; Bordin, Luciana

    2014-08-01

    A wide variety of sperm preparation protocols are currently available for assisted conception. They include density gradient separation and washing methods. Both aim at isolating and capacitating as much motile sperm as possible for subsequent oocyte fertilization. The aim of this study was to examine the effects of four commercial sperm washing buffers on sperm viability and capacitation. Semen samples from 48 healthy donors (normal values of sperm count, motility, morphology, and volume) were analyzed. After separation (density gradient 40/80%), sperm were incubated in various buffers then analysed for reactive oxygen species (ROS) production, viability, tyrosine phosphorylation (Tyr-P), cholera toxin B subunit (CTB) labeling, and the acrosome reaction (AR). The buffers affected ROS generation in various ways resulting either in rapid cell degeneration (when the amount of ROS was too high for cell survival) or the inability of the cells to maintain correct functioning (when ROS were too few). Only when the correct ROS generation curve was maintained, suitable membrane reorganization, evidenced by CTB labeling was achieved, leading to the highest percentages of both Tyr-P- and acrosome-reacted-cells. Distinguishing each particular pathological state of the sperm sample would be helpful to select the preferred buffer treatment since both ROS production and membrane reorganization can be significantly altered by commercial buffers.

  16. Production and economic viability of feedlot beef cattle categories

    Directory of Open Access Journals (Sweden)

    Petrônio Batista dos Santos

    2017-04-01

    Full Text Available This study was realized to evaluate the production and economic viability of finished beef cattle in feedlot in the Cerrado biome of Piauí State, Brazil. One hundred and fifty cattle -50 bulls (B with an body weight of 283.0 ± 20.82 kg, at 30 months of age; and 100 cull cows (CC with an body weight of 296.1 ± 17.80 kg, at 100 months of age- were used in a completely randomized design. The animal performance indicators for the evaluation of economic viability were initial age (months, slaughter age (months, was initial body weight (kg, final body weight (kg, daily feed intake (kg animal-1; kg kg-1 BW, diet cost (R$ kg-1 of diet, cost of kg produced (R$ kg-1 produced, and average price of the kg of meat for finishing (R$. The CC consumed more sorghum silage and concentrate than B (p < 0.05.There was a difference between the categories (p < 0.05 for gross revenue, balance, opportunity cost, and net revenue per animal, with higher values found for the steer category. The animal category did not affect the profitability of the system, although the bulls provided lower revenues than cull cows.

  17. Noninvasive diagnosis of seed viability using infrared thermography.

    Science.gov (United States)

    Kranner, Ilse; Kastberger, Gerald; Hartbauer, Manfred; Pritchard, Hugh W

    2010-02-23

    Recent advances in the noninvasive analyses of plant metabolism include stress imaging techniques, mainly developed for vegetative tissues. We explored if infrared thermography can be used to predict whether a quiescent seed will germinate or die upon water uptake. Thermal profiles of viable, aged, and dead Pisum sativum seeds were recorded, and image analysis of 22,000 images per individual seed showed that infrared thermography can detect imbibition- and germination-associated biophysical and biochemical changes. These "thermal fingerprints" vary with viability in this species and in Triticum aestivum and Brassica napus seeds. Thermogenesis of the small individual B. napus seeds was at the limit of the technology. We developed a computer model of "virtual pea seeds," that uses Monte Carlo simulation, based on the heat production of major seed storage compounds to unravel physico-chemical processes of thermogenesis. The simulation suggests that the cooling that dominates the early thermal profiles results from the dissolution of low molecular-weight carbohydrates. Moreover, the kinetics of the production of such "cooling" compounds over the following 100 h is dependent on seed viability. We also developed a deterministic tool that predicts in the first 3 hours of water uptake, when seeds can be redried and stored again, whether or not a pea seed will germinate. We believe that the early separation of individual, ungerminated seeds (live, aged, or dead) before destructive germination assessment creates unique opportunities for integrative studies on cell death, differentiation, and development.

  18. Effects of drinking desalinated seawater on cell viability and proliferation.

    Science.gov (United States)

    Macarrão, Camila Longhi; Bachi, André Luis Lacerda; Mariano, Mario; Abel, Lucia Jamli

    2017-06-01

    Desalination of seawater is becoming an important means to address the increasing scarcity of freshwater resources in the world. Seawater has been used as drinking water in the health, food, and medical fields and various beneficial effects have been suggested, although not confirmed. Given the presence of 63 minerals and trace elements in drinking desalinated seawater (63 DSW), we evaluated their effects on the behavior of tumorigenic and nontumorigenic cells through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and annexin-V-fluorescein isothiocyanate/propidium iodide staining. Our results showed that cell viability and proliferation in the presence of 63 DSW were significantly greater than in mineral water and in the presence of fetal bovine serum in a dose-dependent manner. Furthermore, 63 DSW showed no toxic effect on murine embryonic fibroblast (NIH-3T3) and murine melanoma (B16-F10) cells. In another assay, we also showed that pre-treatment of non-adherent THP-1 cells with 63 DSW reduces apoptosis incidence, suggesting a protective effect against cell death. We conclude that cell viability and proliferation were improved by the mineral components of 63 DSW and this effect can guide further studies on health effects associated with DSW consumption.

  19. Noninvasive diagnosis of seed viability using infrared thermography

    Science.gov (United States)

    Kranner, Ilse; Kastberger, Gerald; Hartbauer, Manfred; Pritchard, Hugh W.

    2010-01-01

    Recent advances in the noninvasive analyses of plant metabolism include stress imaging techniques, mainly developed for vegetative tissues. We explored if infrared thermography can be used to predict whether a quiescent seed will germinate or die upon water uptake. Thermal profiles of viable, aged, and dead Pisum sativum seeds were recorded, and image analysis of 22,000 images per individual seed showed that infrared thermography can detect imbibition- and germination-associated biophysical and biochemical changes. These “thermal fingerprints” vary with viability in this species and in Triticum aestivum and Brassica napus seeds. Thermogenesis of the small individual B. napus seeds was at the limit of the technology. We developed a computer model of “virtual pea seeds,” that uses Monte Carlo simulation, based on the heat production of major seed storage compounds to unravel physico-chemical processes of thermogenesis. The simulation suggests that the cooling that dominates the early thermal profiles results from the dissolution of low molecular-weight carbohydrates. Moreover, the kinetics of the production of such “cooling” compounds over the following 100 h is dependent on seed viability. We also developed a deterministic tool that predicts in the first 3 hours of water uptake, when seeds can be redried and stored again, whether or not a pea seed will germinate. We believe that the early separation of individual, ungerminated seeds (live, aged, or dead) before destructive germination assessment creates unique opportunities for integrative studies on cell death, differentiation, and development. PMID:20133712

  20. Effect of Antarctic solar radiation on sewage bacteria viability.

    Science.gov (United States)

    Hughes, Kevin A

    2005-06-01

    The majority of coastal Antarctic research stations discard untreated sewage waste into the near-shore marine environment. However, Antarctic solar conditions are unique, with ozone depletion increasing the proportion of potentially damaging ultraviolet-B (UV-B) radiation reaching the marine environment. This study assessed the influence of Antarctic solar radiation on the viability of Escherichia coli and sewage microorganisms at Rothera Research Station, Adelaide Island, Antarctic Peninsula. Cell viability decreased with increased exposure time and with exposure to shorter wavelengths of solar radiation. Cell survival also declined with decreasing cloud cover, solar zenith angle and ozone column depth. However, particulates in sewage increased the persistence of viable bacteria. Ultraviolet radiation doses over Rothera Point were highest during the austral summer. During this time, solar radiation may act to partially reduce the number of viable sewage-derived microorganisms in the surface seawater around Antarctic outfalls. Nevertheless, this effect is not reliable and every effort should be made to fully treat sewage before release into the Antarctic marine environment.

  1. A Review: The Probiotic Bacteria Viability under Different Conditions

    Directory of Open Access Journals (Sweden)

    Lavinia Florina CALINOIU

    2016-11-01

    Full Text Available This review summarized the current knowledge on probiotics and on the effects that different conditions have under this type of bacteria. The purpose of this review was to evaluate the survival rate/resistance or viability of different probiotic bacteria under several conditions, such as: processing, food composition, storage, freezing, thawing, refrigeration, temperature, oxygen, pH, gastrointestinal environment and package. Nowadays, the demand on probiotic functional foods is increasing rapidly, as the consumers became more aware about the potential health benefits, due to the fact that probiotics help in maintaining the balance and composition of intestinal flora and protect it from pathogens. A daily ingestion of 108–109 CFU ml−1 probiotic microorganisms is crucial in order to be able to demonstrate an effect in our organism, considering the dose and the effect of storage/gastrointestinal environments on the probiotic viability. Microencapsulation of probiotics in different polysaccharides was proven to be an ideal way to preserve and protect the cells from detrimental factors during processing, storage or resistance in the gastrointestinal transit, as many studies demonstrate it. There is a general interest in the improvement of the physical and mechanical stability of the polymers used in probiotics encapsulation, to ensure high population of probiotics not only in food during storage, but also after gastrointestinal digestion. Also, the carrier plays a very important role and should be carefully examined.

  2. Effect of magnetic nanoparticle heating on cortical neuron viability.

    Science.gov (United States)

    Rivet, Christopher J; Yuan, Yuan; Gilbert, Ryan J; Borca-Tasciuc, Diana-Andra

    2014-03-01

    Superparamagnetic iron oxide nanoparticles are currently approved for use as an adjunctive treatment to glioblastoma multiforme radiotherapy. Radio frequency stimulation of the nanoparticles generates localised hyperthermia, which sensitises the tumour to the effects of radiotherapy. Clinical trials reported thus far are promising, with an increase in patient survival rate; however, what are left unaddressed are the implications of this technology on the surrounding healthy tissue. Aminosilane-coated iron oxide nanoparticles suspended in culture medium were applied to chick embryonic cortical neuron cultures. Cultures were heated to 37 °C or 45 °C by an induction coil system for 2 h. The latter regime emulates the therapeutic conditions of the adjunctive therapy. Cellular viability and neurite retraction was quantified 24 h after exposure to the hyperthermic events. The hyperthermic load inflicted little damage to the neuron cultures, as determined by calcein-AM, propidium iodide, and alamarBlue® assays. Fluorescence imaging was used to assess the extent of neurite retraction which was found to be negligible. Retention of chick, embryonic cortical neuron viability was confirmed under the thermal conditions produced by radiofrequency stimulation of iron oxide nanoparticles. While these results are not directly applicable to clinical applications of hyperthermia, the thermotolerance of chick embryonic cortical neurons is promising and calls for further studies employing human cultures of neurons and glial cells.

  3. On the Smarandache LCM ratio

    National Research Council Canada - National Science Library

    A A K Majumdar

    2016-01-01

    Two types of the Smarandache LCM ratio functions have been introduced by Murthy [1]. Recently, the second type of the Smarandache LCM ratio function has been considered by Khainar, Vyawahare and Salunke...

  4. Analysis of the effect of cryoprotectant medium composition to viability of autologous hematopoietic cells collected by leukapheresis.

    Science.gov (United States)

    Kozlowska-Skrzypczak, M; Kubiak, A; Bembnista, E; Matuszak, P; Komarnicki, M

    2014-10-01

    Cryopreservation of hematopoietic stem cells intended for autologous transplantation is a crucial element of the banking process. Although cryopreservation techniques are well known, improvement is needed. This study was designed to optimize cryopreservation to improve the quantitative and qualitative parameters of hematopoietic stem cells in the material intended for transplantation. We used available opportunities to provide the best quantitative and qualitative parameters of hematopoietic stem cell transplants processed in a closed system. Two hundred forty-eight products of hematopoietic stem cells collected by leukapheresis from patients with lymphoproliferative disorders create the basis of this report. The material was frozen in a controlled-rate freezer and stored in containers in the vapor phase of LN2 (-160°C). The composition of a cryoprotectant medium was modified. For freezing, 192 probes were used with a cryoprotective medium containing 20% dimethyl sulfoxide (DMSO) and enriched RPMI 1640. For 56 samples, we used 20% DMSO in autologous plasma harvested during leukapheresis. Products of hematopoietic stem cells and cryoprotectant medium were combined in a 1:1 ratio. The final number of nuclear cells did not exceed 2 × 10(8)/mL. Analysis was performed after thawing the probes. Viability of nuclear cells has been assessed using the microscopic technique after incubation in Trypan blue and the CD34+ cells by flow cytometry using the 7-aminoactynomycin D. A statistical analysis has been conducted using the Statistica program (StatSoft, Cracow, Poland). The results show that the application of autologous plasma is linked with higher viability of nuclear cells and CD34+ cells. Moreover, statistical analysis of the nuclear cells and CD34+ cells viability differs significantly between groups frozen using RPMI 1640 and autologous plasma (P < .05). To assess the viability of CD34+, cells frozen using RPMI 1640 results showed a large span of at 16.4% to 99

  5. Polyvinylpyrrolidone-Based Bio-Ink Improves Cell Viability and Homogeneity during Drop-On-Demand Printing.

    Science.gov (United States)

    Ng, Wei Long; Yeong, Wai Yee; Naing, May Win

    2017-02-16

    Drop-on-demand (DOD) bioprinting has attracted huge attention for numerous biological applications due to its precise control over material volume and deposition pattern in a contactless printing approach. 3D bioprinting is still an emerging field and more work is required to improve the viability and homogeneity of printed cells during the printing process. Here, a general purpose bio-ink was developed using polyvinylpyrrolidone (PVP) macromolecules. Different PVP-based bio-inks (0%-3% w/v) were prepared and evaluated for their printability; the short-term and long-term viability of the printed cells were first investigated. The Z value of a bio-ink determines its printability; it is the inverse of the Ohnesorge number (Oh), which is the ratio between the Reynolds number and a square root of the Weber number, and is independent of the bio-ink velocity. The viability of printed cells is dependent on the Z values of the bio-inks; the results indicated that the cells can be printed without any significant impairment using a bio-ink with a threshold Z value of ≤9.30 (2% and 2.5% w/v). Next, the cell output was evaluated over a period of 30 min. The results indicated that PVP molecules mitigate the cell adhesion and sedimentation during the printing process; the 2.5% w/v PVP bio-ink demonstrated the most consistent cell output over a period of 30 min. Hence, PVP macromolecules can play a critical role in improving the cell viability and homogeneity during the bioprinting process.

  6. Polyvinylpyrrolidone-Based Bio-Ink Improves Cell Viability and Homogeneity during Drop-On-Demand Printing

    Science.gov (United States)

    Ng, Wei Long; Yeong, Wai Yee; Naing, May Win

    2017-01-01

    Drop-on-demand (DOD) bioprinting has attracted huge attention for numerous biological applications due to its precise control over material volume and deposition pattern in a contactless printing approach. 3D bioprinting is still an emerging field and more work is required to improve the viability and homogeneity of printed cells during the printing process. Here, a general purpose bio-ink was developed using polyvinylpyrrolidone (PVP) macromolecules. Different PVP-based bio-inks (0%–3% w/v) were prepared and evaluated for their printability; the short-term and long-term viability of the printed cells were first investigated. The Z value of a bio-ink determines its printability; it is the inverse of the Ohnesorge number (Oh), which is the ratio between the Reynolds number and a square root of the Weber number, and is independent of the bio-ink velocity. The viability of printed cells is dependent on the Z values of the bio-inks; the results indicated that the cells can be printed without any significant impairment using a bio-ink with a threshold Z value of ≤9.30 (2% and 2.5% w/v). Next, the cell output was evaluated over a period of 30 min. The results indicated that PVP molecules mitigate the cell adhesion and sedimentation during the printing process; the 2.5% w/v PVP bio-ink demonstrated the most consistent cell output over a period of 30 min. Hence, PVP macromolecules can play a critical role in improving the cell viability and homogeneity during the bioprinting process. PMID:28772551

  7. Polyvinylpyrrolidone-Based Bio-Ink Improves Cell Viability and Homogeneity during Drop-On-Demand Printing

    Directory of Open Access Journals (Sweden)

    Wei Long Ng

    2017-02-01

    Full Text Available Drop-on-demand (DOD bioprinting has attracted huge attention for numerous biological applications due to its precise control over material volume and deposition pattern in a contactless printing approach. 3D bioprinting is still an emerging field and more work is required to improve the viability and homogeneity of printed cells during the printing process. Here, a general purpose bio-ink was developed using polyvinylpyrrolidone (PVP macromolecules. Different PVP-based bio-inks (0%–3% w/v were prepared and evaluated for their printability; the short-term and long-term viability of the printed cells were first investigated. The Z value of a bio-ink determines its printability; it is the inverse of the Ohnesorge number (Oh, which is the ratio between the Reynolds number and a square root of the Weber number, and is independent of the bio-ink velocity. The viability of printed cells is dependent on the Z values of the bio-inks; the results indicated that the cells can be printed without any significant impairment using a bio-ink with a threshold Z value of ≤9.30 (2% and 2.5% w/v. Next, the cell output was evaluated over a period of 30 min. The results indicated that PVP molecules mitigate the cell adhesion and sedimentation during the printing process; the 2.5% w/v PVP bio-ink demonstrated the most consistent cell output over a period of 30 min. Hence, PVP macromolecules can play a critical role in improving the cell viability and homogeneity during the bioprinting process.

  8. Direct In Situ Viability Assessment of Bacteria in Probiotic Dairy Products Using Viability Staining in Conjunction with Confocal Scanning Laser Microscopy

    Science.gov (United States)

    Auty, M. A. E.; Gardiner, G. E.; McBrearty, S. J.; O'Sullivan, E. O.; Mulvihill, D. M.; Collins, J. K.; Fitzgerald, G. F.; Stanton, C.; Ross, R. P.

    2001-01-01

    The viability of the human probiotic strains Lactobacillus paracasei NFBC 338 and Bifidobacterium sp. strain UCC 35612 in reconstituted skim milk was assessed by confocal scanning laser microscopy using the LIVE/DEAD BacLight viability stain. The technique was rapid (diluent. PMID:11133474

  9. Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

    Science.gov (United States)

    Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

    2017-01-01

    The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Advances and Challenges in Viability Detection of Foodborne Pathogens

    Directory of Open Access Journals (Sweden)

    Dexin Zeng

    2016-11-01

    Full Text Available Foodborne outbreaks are a serious public health and food safety concern worldwide. There is a great demand for rapid, sensitive, specific, and accurate methods to detect microbial pathogens in foods. Conventional methods based on cultivation of pathogens have been the gold standard protocols; however, they take up to a week to complete. Molecular assays such as polymerase chain reaction (PCR, sequencing, microarray technologies have been widely used in detection of foodborne pathogens. Among molecular assays, PCR technology conventional and real-time PCR (qPCR is most commonly used in the foodborne pathogen detection because of its high sensitivity and specificity. However, a major drawback of PCR is its inability to differentiate the DNA from dead and viable cells, and this is a critical factor for the food industry, regulatory agencies and the consumer. To remedy this shortcoming, researchers have used biological dyes such as ethidium monoazide (EMA and propidium monoazide (PMA to pretreat samples before DNA extraction to intercalate the DNA of dead cells in food samples, and then proceed with regular DNA preparation and qPCR. By combining PMA treatment with qPCR (PMA-qPCR, scientists have applied this technology to detect viable cells of various bacterial pathogens in foods. The incorporation of PMA into PCR-based assays for viability detection of pathogens in foods has increased significantly in the last decade. On the other hand, some downsides with this approach have been noted, particularly to achieve complete suppression of signal of DNA from the dead cells present in some particular food matrix. Nowadays, there is a tendency of more and more researchers adapting this approach for viability detection; and a few commercial kits based on PMA are available in the market. As time goes on, more scientists apply this approach to a broader range of pathogen detections, this viability approach (PMA or other chemicals such as platinum compound

  11. Cosmological viability of theories with massive spin-2 fields

    Energy Technology Data Exchange (ETDEWEB)

    Koennig, Frank

    2017-03-30

    Theories of spin-2 fields take on a particular role in modern physics. They do not only describe the mediation of gravity, the only theory of fundamental interactions of which no quantum field theoretical description exists, it furthermore was thought that they necessarily predict massless gauge bosons. Just recently, a consistent theory of a massive graviton was constructed and, subsequently, generalized to a bimetric theory of two interacting spin-2 fields. This thesis studies both the viability and consequences at cosmological scales in massive gravity as well as bimetric theories. We show that all consistent models that are free of gradient and ghost instabilities behave like the cosmological standard model, LCDM. In addition, we construct a new theory of massive gravity which is stable at both classical background and quantum level, even though it suffers from the Boulware-Deser ghost.

  12. Ponatinib reduces viability, migration, and functionality of human endothelial cells.

    Science.gov (United States)

    Gover-Proaktor, Ayala; Granot, Galit; Shapira, Saar; Raz, Oshrat; Pasvolsky, Oren; Nagler, Arnon; Lev, Dorit L; Inbal, Aida; Lubin, Ido; Raanani, Pia; Leader, Avi

    2017-06-01

    Tyrosine kinase inhibitors (TKIs) have revolutionized the prognosis of chronic myeloid leukemia. With the advent of highly efficacious therapy, the focus has shifted toward managing TKI adverse effects, such as vascular adverse events (VAEs). We used an in vitro angiogenesis model to investigate the TKI-associated VAEs. Our data show that imatinib, nilotinib, and ponatinib reduce human umbilical vein endothelial cells (HUVECs) viability. Pharmacological concentrations of ponatinib induced apoptosis, reduced migration, inhibited tube formation of HUVECs, and had a negative effect on endothelial progenitor cell (EPC) function. Furthermore, in HUVECs transfected with VEGF receptor 2 (VEGFR2), the effect of ponatinib on tube formation and on all parameters representing normal endothelial cell function was less prominent than in control cells. This is the first report regarding the pathogenesis of ponatinib-associated VAEs. The antiangiogenic effect of ponatinib, possibly mediated by VEGFR2 inhibition, as shown in our study, is another piece in the intricate puzzle of TKI-associated VAEs.

  13. Technical viability and development needs for waste forms and facilities

    Energy Technology Data Exchange (ETDEWEB)

    Pegg, I.; Gould, T.

    1996-05-01

    The objective of this breakout session was to provide a forum to discuss technical issues relating to plutonium-bearing waste forms and their disposal facilities. Specific topics for discussion included the technical viability and development needs associated with the waste forms and/or disposal facilities. The expected end result of the session was an in-depth (so far as the limited time would allow) discussion of key issues by the session participants. The session chairs expressed allowance for, and encouragement of, alternative points of view, as well as encouragement for discussion of any relevant topics not addressed in the paper presentations. It was not the intent of this session to recommend or advocate any one technology over another.

  14. Viability report for the ByWater Lakes project

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, Thomas Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Klise, Geoffrey Taylor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Passell, Howard David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Peplinski, William J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-10-01

    This report presents the results from the hydrological, ecological, and renewable energy assessments conducted by Sandia National Laboratories at the ByWater Lakes site in Espanola, New Mexico for ByWater Recreation LLC and Avanyu Energy Services through the New Mexico small business assistance (NMSBA) program. Sandia's role was to assess the viability and provide perspective for enhancing the site to take advantage of renewable energy resources, improve and sustain the natural systems, develop a profitable operation, and provide an asset for the local community. Integral to this work was the identification the pertinent data and data gaps as well as making general observations about the potential issues and concerns that may arise from further developing the site. This report is informational only with no consideration with regards to the business feasibility of the various options that ByWater and Avanyu may be pursuing.

  15. Reconstruction of boundary conditions from internal conditions using viability theory

    KAUST Repository

    Hofleitner, Aude

    2012-06-01

    This article presents a method for reconstructing downstream boundary conditions to a HamiltonJacobi partial differential equation for which initial and upstream boundary conditions are prescribed as piecewise affine functions and an internal condition is prescribed as an affine function. Based on viability theory, we reconstruct the downstream boundary condition such that the solution of the Hamilton-Jacobi equation with the prescribed initial and upstream conditions and reconstructed downstream boundary condition satisfies the internal value condition. This work has important applications for estimation in flow networks with unknown capacity reductions. It is applied to urban traffic, to reconstruct signal timings and temporary capacity reductions at intersections, using Lagrangian sensing such as GPS devices onboard vehicles.

  16. Relationship between humidity and influenza A viability in droplets and implications for influenza's seasonality.

    Directory of Open Access Journals (Sweden)

    Wan Yang

    Full Text Available Humidity has been associated with influenza's seasonality, but the mechanisms underlying the relationship remain unclear. There is no consistent explanation for influenza's transmission patterns that applies to both temperate and tropical regions. This study aimed to determine the relationship between ambient humidity and viability of the influenza A virus (IAV during transmission between hosts and to explain the mechanisms underlying it. We measured the viability of IAV in droplets consisting of various model media, chosen to isolate effects of salts and proteins found in respiratory fluid, and in human mucus, at relative humidities (RH ranging from 17% to 100%. In all media and mucus, viability was highest when RH was either close to 100% or below ∼50%. When RH decreased from 84% to 50%, the relationship between viability and RH depended on droplet composition: viability decreased in saline solutions, did not change significantly in solutions supplemented with proteins, and increased dramatically in mucus. Additionally, viral decay increased linearly with salt concentration in saline solutions but not when they were supplemented with proteins. There appear to be three regimes of IAV viability in droplets, defined by humidity: physiological conditions (∼100% RH with high viability, concentrated conditions (50% to near 100% RH with lower viability depending on the composition of media, and dry conditions (<50% RH with high viability. This paradigm could help resolve conflicting findings in the literature on the relationship between IAV viability in aerosols and humidity, and results in human mucus could help explain influenza's seasonality in different regions.

  17. Thermoforming of tracheal cartilage: viability, shape change, and mechanical behavior.

    Science.gov (United States)

    Chae, Yongseok; Protsenko, Dmitriy; Holden, Paul K; Chlebicki, Cara; Wong, Brian J F

    2008-10-01

    Trauma, emergent tracheostomy, and prolonged intubation are common causes of severe deformation and narrowing of the trachea. Laser technology may be used to reshape tracheal cartilage using minimally invasive methods. The objectives of this study were to determine: (1) the dependence of tracheal cartilage shape change on temperature and laser dosimetry using heated saline bath immersion and laser irradiation, respectively, (2) the effect of temperature on the mechanical behavior of cartilage, and (3) tissue viability as a function of laser dosimetry. Ex vivo rabbit trachea cartilage specimens were bent and secured around a cylinder (6 mm), and then immersed in a saline bath (45 and 72 degrees C) for 5-100 seconds. In separate experiments, tracheal specimens were irradiated with a diode laser (lambda = 1.45 microm, 220-400 J/cm(2)). Mechanical analysis was then used to determine the elastic modulus in tension after irradiation. Fluorescent viability assays combined with laser scanning confocal microscopy (LSCM) were employed to image and identify thermal injury regions. Shape change transition zones, between 62 and 66 degrees C in the saline heating bath and above power densities of 350 J/cm(2) (peak temperatures 65+/-10 degrees C) for laser irradiation were identified. Above these zones, the elastic moduli were higher (8.2+/-4 MPa) than at lower temperatures (4.5+/-3 MPa). LSCM identified significant loss of viable chondrocytes within the laser-irradiation zones. Our results indicate a change in mechanical properties occurs with laser irradiation and further demonstrates that significant thermal damage is concurrent with clinically relevant shape change in the elastic cartilage tissues of the rabbit trachea using the present laser and dosimetry parameters. (c) 2008 Wiley-Liss, Inc.

  18. Pore architecture and cell viability on freeze dried 3D recombinant human collagen-peptide (RHC)–chitosan scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing; Zhou, Aimei; Deng, Aipeng [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Yang, Yang [Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Gao, Lihu; Zhong, Zhaocai [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Yang, Shulin, E-mail: yshulin@njust.edu.cn [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2015-04-01

    Pore architecture of 3D scaffolds used in tissue engineering plays a critical role in the maintenance of cell survival, proliferation and further promotion of tissue regeneration. We investigated the pore size and structure, porosity, swelling as well as cell viability of a series of recombinant human collagen-peptide–chitosan (RHCC) scaffolds fabricated by lyophilization. In this paper, freezing regime containing a final temperature of freezing (T{sub f}) and cooling rates was applied to obtain scaffolds with pore size ranging from 100 μm to 120 μm. Other protocols of RHC/chitosan suspension concentration and ratio modification were studied to produce more homogenous and appropriate structural scaffolds. The mean pore size decreased along with the decline of T{sub f} at a slow cooling rate of 0.7 °C/min; a more rapid cooling rate under 5 °C/min resulted to a smaller pore size and more homogenous microstructure. High concentration could reduce pore size and lead to thick well of scaffold, while improved the ratio of RHC, lamellar and fiber structure coexisted with cellular pores. Human umbilical vein endothelial cells (HUVECs) were seeded on these manufactured scaffolds, the cell viability represented a negative correlation to the pore size. This study provides an alternative method to fabricate 3D RHC–chitosan scaffolds with appropriate pores for potential tissue engineering. - Highlights: • Fabrication of recombinant human collagen-chitosan scaffolds by freezing drying • Influence of freeze drying protocols on lyophilized scaffolds • Pore size, microstructure, porosity, swelling and cell viability were compared. • The optimized porous scaffold is suitable for cell (HUVEC) seeding.

  19. Sex Ratio Elasticity Influences the Selection of Sex Ratio Strategy

    Science.gov (United States)

    Wang, Yaqiang; Wang, Ruiwu; Li, Yaotang; (Sam) Ma, Zhanshan

    2016-12-01

    There are three sex ratio strategies (SRS) in nature—male-biased sex ratio, female-biased sex ratio and, equal sex ratio. It was R. A. Fisher who first explained why most species in nature display a sex ratio of ½. Consequent SRS theories such as Hamilton’s local mate competition (LMC) and Clark’s local resource competition (LRC) separately explained the observed deviations from the seemingly universal 1:1 ratio. However, to the best of our knowledge, there is not yet a unified theory that accounts for the mechanisms of the three SRS. Here, we introduce the price elasticity theory in economics to define sex ratio elasticity (SRE), and present an analytical model that derives three SRSs based on the following assumption: simultaneously existing competitions for both resources A and resources B influence the level of SRE in both sexes differently. Consequently, it is the difference (between two sexes) in the level of their sex ratio elasticity that leads to three different SRS. Our analytical results demonstrate that the elasticity-based model not only reveals a highly plausible mechanism that explains the evolution of SRS in nature, but also offers a novel framework for unifying two major classical theories (i.e., LMC & LRC) in the field of SRS research.

  20. Variation of Pollen Viability and Storability in Asparagus (Asparagus offcinalis L.) Cultivars

    OpenAIRE

    Ozaki, Yukio; Tashiro, Tomoko; Kurahashi, Tomoko; Okubo, Hiroshi

    1999-01-01

    The optimal culture condition for evaluating pollen viability of asparagus was studied. Sucrose was an effective constituent of the media for raising pollen germination rate. The medium containing 30% sucrose, 0.01% borate and 3% agar was found to be optimum for assessing pollen viability. Effects of temperature and light conditions during in vitro culture on pollen germination rate were not recognized in the range of 20-30℃ in this investigation. Varietal difference of pollen viability and s...

  1. Hesperidin inhibits ovarian cancer cell viability through endoplasmic reticulum stress signaling pathways

    OpenAIRE

    Zhao, Jun; Li, Yali; Gao, Jinfang; De, Yinshan

    2017-01-01

    Hesperidin is a vitamin P flavonoid compound primarily present in citrus fruits. The aim of the present study was to investigate whether hesperidin inhibits ovarian cancer cell viability via endoplasmic reticulum stress signaling pathways. A2780 cells were treated with various doses of hesperidin for 6, 12 or 24 h, and the viability of A2780 cells was assessed using the MTT assay. Hesperidin decreased the viability of A2780 cells and increased cytotoxicity in a dose- and time-dependent manner...

  2. Comparative Efficacy and Economic Viability of Trichoderma Strains ...

    African Journals Online (AJOL)

    FIRST LADY

    cost-ratio. Introduction. Trichoderma species have been known for many years as potential biological control agents against many plant diseases (Adedeji, 2008). The success of. Trichoderma strains as biological control agents is due to their ...

  3. The sex ratio at birth.

    Science.gov (United States)

    Rubin, E

    1967-10-01

    Several aspects of the disparity in birth ratio of males over females are discussed including variations among different races, variations by order of birth, by age of the parent, and in multiple births. Avenues of statistical exploration are suggested in an attempt to indicate certain peculiarities in nature. The Negro population in the United States has a sex ratio of 102 males to 100 females as opposed to 105:100 for whites, a highly significant difference. Inferences from these statistics are suggested for study of the sex ratios of mixed unions. The group classified as Mulatto show a lower sex ratio and further analysis of this was suggested including examination of slave records. For the white population sex ratio declines from 106.2 to 102.9 between 1st order and 7th order births. This is highly significant. However, nonwhite determinations were more irregular. Data limitations on sex ratio by age of parent prevented conclusive results. Multiple births among whites show a decline from 105.3 for single live births to 103.2 for twins and 86.1 for all other plural deliveries. Among nonwhites these ratios are 102.3, 99.7, and 102.6 respectively. Further information should be developed using the multiple facts relating to the sex ratio at birth.

  4. Incentive Ratios of Fisher Markets

    DEFF Research Database (Denmark)

    Chen, Ning; Deng, Xuaitue; Zhang, Hongyang

    2012-01-01

    by misreporting their private information, we show that the percentage of improvement by a unilateral strategic play, called incentive ratio, is rather limited—it is less than 2 for linear markets and at most $e^{1/e}\\thickapprox 1.445$ for Cobb-Douglas markets. We further prove that both ratios are tight....

  5. Holes at High Blowing Ratios

    Directory of Open Access Journals (Sweden)

    Phillip M. Ligrani

    1996-01-01

    Full Text Available Experimental results are presented which describe the development and structure of flow downstream of a single row of holes with compound angle orientations producing film cooling at high blowing ratios. This film cooling configuration is important because similar arrangements are frequently employed on the first stage of rotating blades of operating gas turbine engines. With this configuration, holes are spaced 6d apart in the spanwise direction, with inclination angles of 24 degrees, and angles of orientation of 50.5 degrees. Blowing ratios range from 1.5 to 4.0 and the ratio of injectant to freestream density is near 1.0. Results show that spanwise averaged adiabatic effectiveness, spanwise-averaged iso-energetic Stanton number ratios, surveys of streamwise mean velocity, and surveys of injectant distributions change by important amounts as the blowing ratio increases. This is due to injectant lift-off from the test surface just downstream of the holes.

  6. The viability of native microbial communities in martian environment (model)

    Science.gov (United States)

    Vorobyova, Elena; Cheptcov, Vladimir; Pavlov, Anatolyi; Vdovina, Mariya; Lomasov, Vladimir

    For today the important direction in astrobiology is the experimental simulation of extraterrestrial habitats with the assessment of survivability of microorganisms in such conditions. A new task is to investigate the resistance of native microbial ecosystems which are well adapted to the environment and develop unique protection mechanisms that enable to ensure biosphere formation. The purpose of this research was to study the viability of microorganisms as well as viability of native microbial communities of arid soils and permafrost under stress conditions simulating space environment and martian regolith environment, estimation of duration of Earth like life in the Martian soil. The experimental data obtained give the proof of the preservation of high population density, biodiversity, and reproduction activity under favorable conditions in the Earth analogues of Martian soil - arid soils (Deserts of Israel and Morocco) and permafrost (East Siberia, Antarctica), after the treatment of samples by ionizing radiation dose up to 100 kGy at the pressure of 1 torr, temperature (- 50oC) and in the presence of perchlorate (5%). It was shown that in simulated conditions close to the parameters of the Martian regolith, the diversity of natural bacterial communities was not decreased, and in some cases the activation of some bacterial populations occurred in situ. Our results allow suggesting that microbial communities like those that inhabit arid and permafrost ecosystems on the Earth, can survive at least 500 thousand years under conditions of near surface layer of the Martian regolith. Extrapolation of the data according to the intensity of ionizing radiation to the open space conditions allows evaluating the potential lifespan of cells inside meteorites as 20-50 thousand years at least. In this work new experimental data have been obtained confirming the occurrence of liquid water and the formation of wet soil layer due to sublimation of ice when the temperature of the

  7. Monitoring the viability of citrus rootstocks seeds stored under refrigeration

    Directory of Open Access Journals (Sweden)

    Sérgio Alves de Carvalho

    2013-03-01

    Full Text Available The citrus nursery tree is produced through the bud grafting process, in which rootstock is usually grown from seed germination. The objective of this research was to evaluate, in two dissimilar environmental conditions, the viability and polyembryony expression of five citrus rootstocks seeds stored in different periods under refrigeration. The rootstock varieties evaluated were: Rangpur lime (Citrus limonia Osb. cv. Limeira, Trifoliate orange (Poncirus trifoliata Raf. cv. Limeira, Citrumelo (P. trifoliata x C. paradisi Macf. cv. Swingle, Sunki mandarin (C. sunki Hort. ex Tanaka and Volkamer lemon (C. volkameriana Ten. & Pasq. cv. Catania 2. The experimental design was the randomized blocks in a 11 x 5 x 2 factorial scheme, evaluating from time zero to the tenth month of storage, the five varieties of rootstock in two environments: germination and growth B.O.D type chamber (Biological Oxygen Demand - Eletrolab Brand Model FC 122 at 25 °C; and greenhouse seedbed with partial temperature control (22 °C to 36 °C and humidity control (75-85%. The plot had 24 seeds in four replicates, using trays with substrate in greenhouse and Petri dishes with filter paper in B.O.D. chamber. The seed germination rate and polyembryony expression were evaluated monthly. It was concluded that Trifoliate and Citrumelo Swingle seeds can be stored for up to seven months, while Volkamer lemon, Rangpur lime and Sunki seeds can be stored for up to ten months. The polyembryony expression rate was slightly higher when measured in greenhouse than in B.O.D. chamber and remained stable in both environments until the seventh month, from which dropped sharply. Citrumelo Swingle seeds expressed the highest polyembryony rate (18.8%, followed by Rangpur lime and Volkamer lemon (average value of 13.7%, Sunki (9.4% and Trifoliate (3.2%. Despite some differences among varieties, the viability of rootstock stored seeds can be monitored either in the greenhouse or in B

  8. Identifying genetic variants that affect viability in large cohorts.

    Directory of Open Access Journals (Sweden)

    Hakhamanesh Mostafavi

    2017-09-01

    Full Text Available A number of open questions in human evolutionary genetics would become tractable if we were able to directly measure evolutionary fitness. As a step towards this goal, we developed a method to examine whether individual genetic variants, or sets of genetic variants, currently influence viability. The approach consists in testing whether the frequency of an allele varies across ages, accounting for variation in ancestry. We applied it to the Genetic Epidemiology Research on Adult Health and Aging (GERA cohort and to the parents of participants in the UK Biobank. Across the genome, we found only a few common variants with large effects on age-specific mortality: tagging the APOE ε4 allele and near CHRNA3. These results suggest that when large, even late-onset effects are kept at low frequency by purifying selection. Testing viability effects of sets of genetic variants that jointly influence 1 of 42 traits, we detected a number of strong signals. In participants of the UK Biobank of British ancestry, we found that variants that delay puberty timing are associated with a longer parental life span (P~6.2 × 10-6 for fathers and P~2.0 × 10-3 for mothers, consistent with epidemiological studies. Similarly, variants associated with later age at first birth are associated with a longer maternal life span (P~1.4 × 10-3. Signals are also observed for variants influencing cholesterol levels, risk of coronary artery disease (CAD, body mass index, as well as risk of asthma. These signals exhibit consistent effects in the GERA cohort and among participants of the UK Biobank of non-British ancestry. We also found marked differences between males and females, most notably at the CHRNA3 locus, and variants associated with risk of CAD and cholesterol levels. Beyond our findings, the analysis serves as a proof of principle for how upcoming biomedical data sets can be used to learn about selection effects in contemporary humans.

  9. A Method for Quantitative Determination of Biofilm Viability

    Directory of Open Access Journals (Sweden)

    Maria Strømme

    2012-06-01

    Full Text Available In this study we present a scheme for quantitative determination of biofilm viability offering significant improvement over existing methods with metabolic assays. Existing metabolic assays for quantifying viable bacteria in biofilms usually utilize calibration curves derived from planktonic bacteria, which can introduce large errors due to significant differences in the metabolic and/or growth rates of biofilm bacteria in the assay media compared to their planktonic counterparts. In the presented method we derive the specific growth rate of Streptococcus mutans bacteria biofilm from a series of metabolic assays using the pH indicator phenol red, and show that this information could be used to more accurately quantify the relative number of viable bacteria in a biofilm. We found that the specific growth rate of S. mutans in biofilm mode of growth was 0.70 h−1, compared to 1.09 h−1 in planktonic growth. This method should be applicable to other bacteria types, as well as other metabolic assays, and, for example, to quantify the effect of antibacterial treatments or the performance of bactericidal implant surfaces.

  10. Using Bayesian Population Viability Analysis to Define Relevant Conservation Objectives.

    Directory of Open Access Journals (Sweden)

    Adam W Green

    Full Text Available Adaptive management provides a useful framework for managing natural resources in the face of uncertainty. An important component of adaptive management is identifying clear, measurable conservation objectives that reflect the desired outcomes of stakeholders. A common objective is to have a sustainable population, or metapopulation, but it can be difficult to quantify a threshold above which such a population is likely to persist. We performed a Bayesian metapopulation viability analysis (BMPVA using a dynamic occupancy model to quantify the characteristics of two wood frog (Lithobates sylvatica metapopulations resulting in sustainable populations, and we demonstrate how the results could be used to define meaningful objectives that serve as the basis of adaptive management. We explored scenarios involving metapopulations with different numbers of patches (pools using estimates of breeding occurrence and successful metamorphosis from two study areas to estimate the probability of quasi-extinction and calculate the proportion of vernal pools producing metamorphs. Our results suggest that ≥50 pools are required to ensure long-term persistence with approximately 16% of pools producing metamorphs in stable metapopulations. We demonstrate one way to incorporate the BMPVA results into a utility function that balances the trade-offs between ecological and financial objectives, which can be used in an adaptive management framework to make optimal, transparent decisions. Our approach provides a framework for using a standard method (i.e., PVA and available information to inform a formal decision process to determine optimal and timely management policies.

  11. MODERN TECHNIQUES OF CERVICAL INSTRUMENTATION IN IMMATURE SKELETON: VIABILITY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Ayrana Soares Aires

    Full Text Available ABSTRACT Objective: This study describes the use of materials for modern cervical instrumentation, evaluating its viability in children and adolescents, and the techniques used in different cases. The efficacy of the techniques was analyzed through improvement of pain, maintenance of cervical range of motion, recovery of craniocervical stability, bone consolidation, and spinal stenosis in the postoperative follow-up. Method: Retrospective study of the clinical and radiological parameters of 27 patients aged two to 16 years with cervical spine diseases. Results: Two patients had chronic dislocation in C1-C2, one had congenital axis spondylolisthesis, two had congenital dislocation in C1-C2, three had tumors, one had kyphosis after laminectomy, one had post-infection kyphosis, one had fracture, 11 were syndromic with instabilities, and five had congenital cervical scoliosis. As to surgical approaches, two patients were transorally operated, three by anterior approach, 15 by posterior approach, two by anterior and posterior approaches, and five were treated in three stages (anterior, posterior and anterior approaches. Regarding the technique of cervical stabilization, seven patients were treated by Goel-Harms technique, two received Goel’s facet distraction, and three, Wright translaminar screws. There were complications in four cases. Two patients in the instrumentation of C1 lateral mass due to poor positioning, one with cerebrospinal fluid fistula and one with surgical wound infection. Conclusion: Modern cervical instrumentation in pediatric patients is a safe and effective technique for the treatment of cervical instability.

  12. Viability and heat resistance of murine norovirus on bread.

    Science.gov (United States)

    Takahashi, Michiko; Takahashi, Hajime; Kuda, Takashi; Kimura, Bon

    2016-01-04

    Contaminated bread was the cause of a large-scale outbreak of norovirus disease in Japan in 2014. Contamination of seafood and uncooked food products by norovirus has been reported several times in the past; however the outbreak resulting from the contamination of bread products was unusual. A few reports on the presence of norovirus on bread products are available; however there have been no studies on the viability and heat resistance of norovirus on breads, which were investigated in this study. ce:italic>/ce:italic> strain 1 (MNV-1), a surrogate for human norovirus, was inoculated directly on 3 types of bread, but the infectivity of MNV-1 on bread samples was almost unchanged after 5days at 20°C. MNV-1 was inoculated on white bread that was subsequently heated in a toaster for a maximum of 2min. The results showed that MNV-1 remained viable if the heating period was insufficient to inactivate. In addition, bread dough contaminated with MNV-1 was baked in the oven. Our results indicated that MNV-1 may remain viable on breads if the heating duration or temperature is insufficient. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. [Methods and applications of population viability analysis (PVA): a review].

    Science.gov (United States)

    Tian, Yu; Wu, Jian-Guo; Kou, Xiao-Jun; Wang, Tian-Ming; Smith, Andrew T; Ge, Jian-Ping

    2011-01-01

    With the accelerating human consumption of natural resources, the problems associated with endangered species caused by habitat loss and fragmentation have become greater and more urgent than ever. Conceptually associated with the theories of island biogeography, population viability analysis (PVA) has been one of the most important approaches in studying and protecting endangered species, and this methodology has occupied a central place in conservation biology and ecology in the past several decades. PVA has been widely used and proven effective in many cases, but its predictive ability and accuracy are still in question. Also, its application needs expand. To overcome some of the problems, we believe that PVA needs to incorporate some principles and methods from other fields, particularly landscape ecology and sustainability science. Integrating landscape pattern and socioeconomic factors into PVA will make the approach theoretically more comprehensive and practically more useful. Here, we reviewed the history, basic conception, research methods, and modeling applications and their accuracies of PVA, and proposed the perspective in this field.

  14. Viability of microencapsulated Lactobacillus casei in synbiotic mayonnaise

    Directory of Open Access Journals (Sweden)

    Lieu, M.D.

    2017-07-01

    Full Text Available In this study, whey protein, maltodextrin and GOS (Galacto-oligosaccharides used as microencapsulating agents to protect Lactobacillus casei during spray-drying and mayonnaise storage. The morphology of microcapsules, pH charges, the survival rate during mayonnaise storage as well as survival in simulated gastric fluid (SGF and intestinal fluid (SIF was tested in this study. The results indicated that whey protein showed a protective effect better than maltodextrin during spray-drying. The particles showed spherical shape and typical concavity of all samples and encapsulating agents were not affected by the size and surface structure of particles. The pH charges were not significantly different in all mayonnaise samples in this test. The viability of free cell L. casei after 6 weeks storage was significant decrease about 4 log CFU/g compared to 1.55 to 3.27 log CFU/g in the mayonnaise samples containing microcapsules in which maltodextrin showed the lowest of L. casei survival rate. In SGF and SIF conditions, maltodextrin act as prebiotic sufficiently which do not need adding GOS. The combination of whey protein and maltodextrin in which maltodextrin plays a role as supporting agents for the spray-drying process as well as prebiotic potential, while whey protein with high buffer property which enhancing the survival rate of L. casie in low pH.

  15. Incorporating parametric uncertainty into population viability analysis models

    Science.gov (United States)

    McGowan, Conor P.; Runge, Michael C.; Larson, Michael A.

    2011-01-01

    Uncertainty in parameter estimates from sampling variation or expert judgment can introduce substantial uncertainty into ecological predictions based on those estimates. However, in standard population viability analyses, one of the most widely used tools for managing plant, fish and wildlife populations, parametric uncertainty is often ignored in or discarded from model projections. We present a method for explicitly incorporating this source of uncertainty into population models to fully account for risk in management and decision contexts. Our method involves a two-step simulation process where parametric uncertainty is incorporated into the replication loop of the model and temporal variance is incorporated into the loop for time steps in the model. Using the piping plover, a federally threatened shorebird in the USA and Canada, as an example, we compare abundance projections and extinction probabilities from simulations that exclude and include parametric uncertainty. Although final abundance was very low for all sets of simulations, estimated extinction risk was much greater for the simulation that incorporated parametric uncertainty in the replication loop. Decisions about species conservation (e.g., listing, delisting, and jeopardy) might differ greatly depending on the treatment of parametric uncertainty in population models.

  16. Wastewater treatment to enhance the economic viability of microalgae culture.

    Science.gov (United States)

    Pires, J C M; Alvim-Ferraz, M C M; Martins, F G; Simões, M

    2013-08-01

    Microalgae culture is still not economically viable and it presents some negative environmental impacts, concerning water, nutrient and energy requirements. In this context, this study aims to review the recent advances on microalgal cultures in wastewaters to enhance their economic viability. We focused on three different culture concepts: (1) suspended cell systems, (2) cell immobilization, and (3) microalgae consortia. Cultures with suspended cells are the most studied. The nutrient removal efficiencies are usually high for wastewaters of different sources. However, biomass harvesting is difficult and a costly process due to the small cell size and lower culture density. On the other hand, the cell immobilization systems showed to be the solution for this problem, having as main limitation the nutrient diffusion from bulk to cells, which results in a reduced nutrient removal efficiency. The consortium between microalgae and bacteria enhances the growth of both microorganisms. This culture concept showed to be a promising technology to improve wastewater treatment, regarding not only nutrient removal but also biomass harvesting by bioflocculation. The aggregation mechanism must be studied in depth to find the process parameters that would lead to an effective and cheap harvesting process.

  17. Microscale Electro-Hydrodynamic Cell Printing with High Viability.

    Science.gov (United States)

    He, Jiankang; Zhao, Xiang; Chang, Jinke; Li, Dichen

    2017-12-01

    Cell printing has gained extensive attentions for the controlled fabrication of living cellular constructs in vitro. Various cell printing techniques are now being explored and developed for improved cell viability and printing resolution. Here an electro-hydrodynamic cell printing strategy is developed with microscale resolution (95%). Unlike the existing electro-hydrodynamic cell jetting or printing explorations, insulating substrate is used to replace conventional semiconductive substrate as the collecting surface which significantly reduces the electrical current in the electro-hydrodynamic printing process from milliamperes (>0.5 mA) to microamperes (printed cells. The smallest width of the electro-hydrodynamically printed hydrogel filament is 82.4 ± 14.3 µm by optimizing process parameters. Multiple hydrogels or multilayer cell-laden constructs can be flexibly printed under cell-friendly conditions. The printed cells in multilayer hydrogels kept alive and gradually spread during 7-days culture in vitro. This exploration offers a novel and promising cell printing strategy which might benefit future biomedical innovations such as microscale tissue engineering, organ-on-a-chip systems, and nanomedicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Tissue viability monitoring: a multi-sensor wearable platform approach

    Science.gov (United States)

    Mathur, Neha; Davidson, Alan; Buis, Arjan; Glesk, Ivan

    2016-12-01

    Health services worldwide are seeking ways to improve patient care for amputees suffering from diabetes, and at the same time reduce costs. The monitoring of residual limb temperature, interface pressure and gait can be a useful indicator of tissue viability in lower limb amputees especially to predict the occurrence of pressure ulcers. This is further exacerbated by elevated temperatures and humid micro environment within the prosthesis which encourages the growth of bacteria and skin breakdown. Wearable systems for prosthetic users have to be designed such that the sensors are minimally obtrusive and reliable enough to faithfully record movement and physiological signals. A mobile sensor platform has been developed for use with the lower limb prosthetic users. This system uses an Arduino board that includes sensors for temperature, gait, orientation and pressure measurements. The platform transmits sensor data to a central health authority database server infrastructure through the Bluetooth protocol at a suitable sampling rate. The data-sets recorded using these systems are then processed using machine learning algorithms to extract clinically relevant information from the data. Where a sensor threshold is reached a warning signal can be sent wirelessly together with the relevant data to the patient and appropriate medical personnel. This knowledge is also useful in establishing biomarkers related to a possible deterioration in a patient's health or for assessing the impact of clinical interventions.

  19. Viability of osteocytes in bone autografts harvested for dental implantology

    Energy Technology Data Exchange (ETDEWEB)

    Guillaume, Bernard [CFI-College Francais d' Implantologie, 6 rue de Rome, 75008 Paris (France); Gaudin, Christine; Georgeault, Sonia; Mallet, Romain; Basle, Michel F; Chappard, Daniel, E-mail: daniel.chappard@univ-angers.f [INSERM, U 922-LHEA, Faculte de Medecine, 49045 Angers Cedex (France)

    2009-02-15

    Bone autograft remains a very useful and popular way for filling bone defects. In maxillofacial surgery or implantology, it is used to increase the volume of the maxilla or mandible before placing dental implants. Because there is a noticeable delay between harvesting the graft and its insertion in the receiver site, we evaluated the morphologic changes at the light and transmission electron microscopy levels. Five patients having an autograft (bone harvested from the chin) were enrolled in the study. A small fragment of the graft was immediately fixed after harvesting and a second one was similarly processed at the end of the grafting period when bone has been stored at room temperature for a 20 min +- 33 s period in saline. A net increase in the number of osteocyte lacunae filled with cellular debris was observed (+41.5%). However no cytologic alteration could be observed in the remaining osteocytes. The viability of these cells is known to contribute to the success of autograft in association with other less well-identified factors.

  20. Viability of Variable Generalised Chaplygin gas - a thermodynamical approach

    CERN Document Server

    Panigrahi, D

    2016-01-01

    The viability of the variable generalised Chaplygin gas (VGCG) model is analysed from the standpoint of its thermodynamical stability criteria with the help of an equation of state, $P = - \\frac{B}{\\rho^{\\alpha}}$, where $B = B_{0}V^{-\\frac{n}{3}}$. Here $B_{0}$ is assumed to be a positive universal constant, $n$ is a constant parameter and $V$ is the volume of the cosmic fluid. We get the interesting result that if the well-known stability conditions of a fluid is adhered to, the values of $n$ are constrained to be negative definite to make $ \\left(\\frac{\\partial P}{\\partial V}\\right)_{S} <0$ \\& $ \\left(\\frac{\\partial P}{\\partial V}\\right)_{T} <0$ throughout the evolution. Moreover the positivity of thermal capacity at constant volume $c_{V}$ as also the validity of the third law of thermodynamics are ensured in this case. For the particular case $n = 0$ the effective equation of state reduces to $\\Lambda$CDM model in the late stage of the universe while for $n <0$ it mimics a phantom-like cosmo...

  1. Evaluating the Viability of Mobile Learning to Enhance Management Training

    Directory of Open Access Journals (Sweden)

    Iain Macdonald

    2011-04-01

    Full Text Available A qualitative research project was conducted to test the viability of augmenting an e-learning program for workplace learners using mobile content delivered through smart phones. Ten learners taking a six week web-based e-learning course were given smart phones which enabled them to access approximately 70% of the course content, in addition to having access to the full course via a standard e-learning website. Mobile content was provided in a variety of forms, including text, audio and video files, a mobile multiple-choice quiz website, and links to streaming videos. Study participants who were regular users of mobile phones found the mobile learning materials to be user-friendly, offering increased convenience and flexibility. Use of the mobile content tended to increase as learners spent more time in their day away from locations where Internet-linked computers could be found. Video was found to be the most effective means of presenting content, followed by audio and text. The most promising role of mobile learning appears to be to augment rather than replace e-learning or blended learning.

  2. Demographic rates and population viability of black bears in Louisiana

    Science.gov (United States)

    Laufenberg, Jared S.; Clark, Joseph D.; Hooker, Michael J.; Lowe, Carrie L.; O'Connell-Goode, Kaitlin C.; Troxler, Jesse C.; Davidson, Maria M.; Chamberlain, Michael J.; Chandler, Richard B.

    2015-01-01

    observed 43 yearling litters for 33 females in the TRB and 21 yearling litters for 19 females in the TRC. The estimated number of cubs and number of yearlings produced per breeding adult female was 0.47 and 0.20, respectively, in the TRB and 0.32 and 0.18 in the TRC. On the basis of matrix projection models, asymptotic growth rates ranged from 1.053 to 1.078 for the TRB and from 1.005 to 1.062 for the TRC, depending on how we treated unresolved fates of adult females. Persistence probabilities estimated from stochastic population models based on telemetry data ranged from 0.997 to 0.998 for the TRC subpopulation depending on model assumptions and were >0.999 for the TRB regardless of model assumptions. We extracted DNA from hair collected at baited, barbed-wire enclosures in the TRB, UARB, and LARB to determine individual identities for capture-mark-recapture (CMR) analysis. We used those detection histories to estimate apparent survival (φ), per-capita recruitment (f), abundance (N), realized growth rate (λ), and long-term viability, based on Bayesian hierarchical modeling methods that allowed estimation of temporal process variance and parameter uncertainty. Based on 23,312 hair samples, annual N for females in the TRB ranged from 133 to 164 during 2006–2012, depending on year and how detection heterogeneity was modeled. Geometric mean of λ ranged from 0.996 to 1.002. In the UARB, we collected 11,643 hair samples from 2007 to 2012, from which estimates of N for females ranged from 23 to 43 during the study period, depending on detection heterogeneity model. The geometric mean of λ ranged from 1.038 to 1.059. Estimated N for females in LARB ranged from 69 to 96, and annual λ ranged from 0.80 to 1.11 based on 3,698 hair samples collected during 2010–2012, also depending on year and heterogeneity model. Probabilities of persistence over 100 years for the TRC and TRB based on stochastic matrix projection models that used vital rate estimates from telemetry data were

  3. Chemicals and lemon essential oil effect on Alicyclobacillus acidoterrestris viability

    Directory of Open Access Journals (Sweden)

    Maria Cristina Maldonado

    2013-12-01

    Full Text Available Alicyclobacillus acidoterrestris is considered to be one of the important target microorganisms in the quality control of acidic canned foods. There is an urgent need to develop a suitable method for inhibiting or controlling the germination and outgrowth of A.acidoterrestris in acidic drinks. The aim of this work was to evaluate the chemicals used in the lemon industry (sodium benzoate, potassium sorbate, and lemon essential oil as a natural compound, against a strain of A.acidoterrestris in MEB medium and in lemon juice concentrate. The results pointed out that sodium benzoate (500-1000-2000 ppm and lemon essential oil (0.08- 0.12- 0.16% completely inhibited the germination of A. acidoterrestris spores in MEB medium and LJC for 11 days. Potassium sorbate (600-1200 ppm was more effective to inhibit the growth of the microbial target in lemon juice than in MEB medium. The effect of sodium benzoate, potassium sorbate and essential oil was sporostatic in MEB and LJC as they did not affect spore viability.

  4. Effect of different carbon nanotubes on cell viability and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    De Nicola, Milena [Dipartimento di Biologia, Universita di Roma Tor Vergata (Italy); Gattia, Daniele Mirabile [Divisione nuovi materiali ENEA Casaccia (Italy); Bellucci, Stefano [INFN Laboratori Nazionali di Frascati (Italy); De Bellis, Giovanni [INFN Laboratori Nazionali di Frascati (Italy); Micciulla, Federico [INFN Laboratori Nazionali di Frascati (Italy); Pastore, Roberto [INFN Laboratori Nazionali di Frascati (Italy); Tiberia, Alessandra [INFN Laboratori Nazionali di Frascati (Italy); Cerella, Claudia [Dipartimento di Biologia, Universita di Roma Tor Vergata (Italy); D' Alessio, Maria [Dipartimento di Biologia, Universita di Roma Tor Vergata (Italy); Antisari, Marco Vittori [Divisione nuovi materiali ENEA Casaccia (Italy); Marazzi, Renzo [Divisione nuovi materiali ENEA Casaccia (Italy); Traversa, Enrico [Dipartimento di Chimica, Universita di Roma Tor Vergata (Italy); Magrini, Andrea [Cattedra Medicina del Lavoro, Universita di Roma Tor Vergata (Italy); Bergamaschi, Antonio [Cattedra di Medicina del Lavoro, Universita Cattolica del Sacro Cuore, Rome (Italy); Ghibelli, Lina [Dipartimento di Biologia, Universita di Roma Tor Vergata (Italy)

    2007-10-03

    Carbon nanotubes (CNTs) are a focus of intense research for their potential applications in multiple diverse applications, including innovative biomedical applications. Due to their very recent discovery, little information is available about the biocompatibility and toxicity of this new class of nanoparticle, and a systematic study on biological interference is lacking. Thus, we decided to explore the toxicity of three different types of carbon nanotube, differing in preparation (arc discharge versus catalysed chemical vapour deposition); size (10-50 versus 100-150 nm wide x 1-10 {mu}m long); contaminants (amorphous C, graphite, fullerenes or iron) and morphological type (multi-walled, MW, or single-walled, SW) on human leukemic U937 cells. We found that these carbon nanotubes exert a strong effect on the proliferation of the reporter U937 monocytic cell. However, these CNTs did not significantly affect the cell viability. These results show that CNTs, though not directly exerting a direct cytotoxic effect, are nonetheless able to deeply alter cell behaviour, and thus we recommend thorough analyses to limit health risk due to uncontrolled exposure.

  5. Technical viability of self-compacting concretes with by-products from crushed coarse aggregate production

    Directory of Open Access Journals (Sweden)

    Edgar Bacarji

    Full Text Available Abstract The main objective of this work is to present the technical viability of Self Compacting Concretes (SCC containing by-products from crushed coarse aggregate production. For this purpose, a vast characterization of these by-products was made; six mixtures of SCC were produced using two different aggregates: granite and mica schist. The binder/dry aggregate (b/agg ratio by mass was 1:3. The following properties were analyzed: compressive strength, direct tensile strength, flexural tensile strength and splitting tensile strength. Granite presented the best mechanical performance. The replacement of natural sand by granite sand generated concretes with the same level of compressive strength and caused an increase in tensile strength values. The incorporation of silica fume into concrete with granite produced an increase of 17% in compressive strength. So, the use of these by-product materials can provide a technically feasible solution that is also consistent with the aims of sustainable development and preservation of the environment.

  6. Mapping myocardial viability using interleaved T1-T2* weighted imaging.

    Science.gov (United States)

    Li, Gang; Dai, Guangping; Xiang, Bo; Mark, John; Tomanek, Boguslaw; Liu, Hongyu; Deslauriers, Roxanne; Tian, Ganghong

    2004-04-01

    The present study was to evaluate the efficacy of our interleaved T1-T2* weighted imaging for assessing myocardial viability. The left anterior descending coronary artery (LAD) of pig hearts (n = 7) were occluded for 2 h, followed by 1 h reperfusion. After removed from animals, the hearts were perfused in a Langendorff apparatus with a mixture of pig blood and crystalloid solution in 1:1 ratio. T1 relaxation times of the myocardium were measured with a TurboFLASH inversion-recovery sequence. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) (0.05 mmol/kg body wt) was then injected as a bolus into the aortic perfusion line. The first pass of the contrast agent through the heart was followed using the interleaved T1-T2* imaging sequence. Once the concentration of the contrast agent was in an equilibrium state, T1 relaxation times were measured again. It was found that the percentage recovery of T2* intensity (PRT2*) at the maximum T1 intensity measured during the first pass of the contrast agent with the interleaved T1-T2* imaging was significantly higher in infarcted myocardium than in normal myocardium. Moreover, the regions showing a high T2* percentage recovery on PRT2* maps matched well with the infarcted myocardium demarcated with triphenyl tetrazolium chloride (TTC) staining. We therefore conclude that infarcted myocardium can be delineated using the interleaved T1-T2* imaging method.

  7. Docetaxel-Chitosan nanoparticles for breast cancer treatment: cell viability and gene expression study.

    Science.gov (United States)

    Mirzaie, Zahra H; Irani, Shiva; Mirfakhraie, Reza; Atyabi, Seyed Mohammad; Dinarvand, Meshkat; Dinarvand, Rassoul; Varshochian, Reyhaneh; Atyabi, Fatemeh

    2016-12-01

    Docetaxel acts through the inhibition of tubulin polymerization and reduction in the expression of BCL-2 gene. In this study, nanoparticles containing Docetaxel were prepared and their effects on the gene expression levels of BCL-2 and BAX genes were investigated. The drug was first conjugated to chitosan, and the nanoparticles were assembled in the presence of hyaluronic acid. Conjugations were confirmed by (1) H-NMR, and the obtained nanoparticles were characterized by dynamic light scattering and SEM. Cytotoxicity of the nanoparticles, cellular uptake, and cell death were evaluated. Finally, the effect of nanoparticles on the expression of BAX and BCL-2 genes in MCF-7 cells were investigated through real-time PCR. The results revealed that the prepared NPs had spherical shape with narrow size distribution of nanoparticles and free Docetaxel investigations revealed that increasing the treatment time with nanoparticles led to decrease in the rate of cell viability. BAX and BCL-2 gene expressions were decreased in nanoparticle-treated cells in comparison with intact cells, while the BAX/BCL-2 ratio was significantly elevated compared with free drug-treated cells after 72 h. Docetaxel-conjugated NPs may offer a promising treatment with low off-target toxicity for breast cancer. © 2016 John Wiley & Sons A/S.

  8. Effects of ambroxol on biofilm adhesion and viability of Pseudomonas aeruginosa quorum sensing defective strain

    Directory of Open Access Journals (Sweden)

    Qi LU

    2013-07-01

    Full Text Available Objective To investigate the effects of ambroxol on the biofilm viability and pristine adhesion of Pseudomonas aeruginosa wild (PAO1 and quorum sensing defective strain (QS, gene deletion of ∆lasI and ∆rhlI. Methods The biofilm was treated by different concentrations (0, 1.875, 3.75mg/ml of ambroxol. The number of colony was measured with agar plate, multifunction fluorometer was used to measure the fluorescence intensity of PAO1 and QS strains at the bottom of 96-well plate. The adhesion ratio (% was calculated to determine the effects of ambroxol on bacterial biofilm adhesion. Results Ambroxol treatment reduced the survival rate of the mutant strains compared to that of wild strain, even though the QS strain had increased the adhesion in the presence of ambroxol compared to that of wild strain (P<0.05. Conclusion Ambroxol has a property of significantly antagonizing quorum-sensing system, suggesting that it might be of importance in treatment against chronic Pseudomonasaeruginosainfections.

  9. Assessing the viability of successful reconstruction of the dynamics of dark energy using varying fundamental couplings

    Energy Technology Data Exchange (ETDEWEB)

    Avelino, P.P., E-mail: ppavelin@fc.up.pt [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Losano, L., E-mail: losano@fisica.ufpb.br [Departamento de Fisica, Universidade Federal da Paraiba, 58051-970 Joao Pessoa, Paraiba (Brazil); Centro de Fisica do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Menezes, R., E-mail: rmenezes@dce.ufpb.br [Departamento de Ciencias Exatas, Universidade Federal da Paraiba, 58297-000 Rio Tinto, PB (Brazil); Departamento de Fisica, Universidade Federal de Campina Grande, 58109-970 Campina Grande, Paraiba (Brazil); Oliveira, J.C.R.E., E-mail: jespain@fe.up.pt [Centro de Fisica do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Departamento de Engenharia Fisica da Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal)

    2012-10-31

    We assess the viability of successful reconstruction of the evolution of the dark energy equation of state using varying fundamental couplings, such as the fine structure constant or the proton-to-electron mass ratio. We show that the same evolution of the dark energy equation of state parameter with cosmic time may be associated with arbitrary variations of the fundamental couplings. Various examples of models with the same (different) background evolution and different (the same) time variation of fundamental couplings are studied in the Letter. Although we demonstrate that, for a broad family of models, it is possible to redefine the scalar field in such a way that its dynamics is that of a standard quintessence scalar field, in general such redefinition leads to the breakdown of the linear relation between the scalar field and the variation of fundamental couplings. This implies that the assumption of a linear coupling is not sufficient to guarantee a successful reconstruction of the dark energy dynamics and consequently additional model dependent assumptions about the scalar field responsible for the dark energy need to be made.

  10. Pressure Ratio to Thermal Environments

    Science.gov (United States)

    Lopez, Pedro; Wang, Winston

    2012-01-01

    A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

  11. Evaluation of the viability of HL60 cells in contact with commonly used microchip materials

    NARCIS (Netherlands)

    Wolbers, F.; ter Braak, Paulus Martinus; le Gac, Severine; Lüttge, Regina; Andersson, Helene; Vermes, I.; van den Berg, Albert; Jensen, K.F; Han, J.; Harrison, D.J.; Voldman, J.

    2005-01-01

    This paper presents beneficial data when deciding to perform cell experiments in lab-on- a-chip devices. The choice of material can influence the viability of mammalian cells. PDMS, precoated with serum or not, suits well for HL60 cells, demonstrating the best results in the viability experiments,

  12. Linking population viability, habitat suitability, and landscape simulation models for conservation planning

    Science.gov (United States)

    Michael A. Larson; Frank R., III Thompson; Joshua J. Millspaugh; William D. Dijak; Stephen R. Shifley

    2004-01-01

    Methods for habitat modeling based on landscape simulations and population viability modeling based on habitat quality are well developed, but no published study of which we are aware has effectively joined them in a single, comprehensive analysis. We demonstrate the application of a population viability model for ovenbirds (Seiurus aurocapillus)...

  13. Sustainable model for financial viability of decentralized biomass gasifier based power projects

    NARCIS (Netherlands)

    Palit, D.; Malhotra, R.; Kumar, Atul

    2011-01-01

    This paper made a modest attempt for designing a sustainable model for financial viability of biomass gasifier power projects for enhancing electricity access in India and other developing countries. For long term sustainability of distributed generation projects in remote rural areas, viability

  14. The effect of oestradiol-17β on the motility, viability and the ...

    African Journals Online (AJOL)

    The effect of oestradiol-17β on the motility, viability and the acrosomal status of bull sperm. ... Pooled semen from Holstein bulls were incubated in the presence of 2, 4, and 8 μg E2/mL for 24 h. Semen was also incubated in ... on viability. Keywords: Bovine males, estradiol, acrosome, motility, spermatozoa, in vitro incubation ...

  15. Assessment of factors that impact on the viability of contract farming ...

    African Journals Online (AJOL)

    This research analyses factors that affect the viability of contract farming in the Zimbabwean maize and soya sector. The objective was to analyse how sustainability factors (social, ethical, environmental and economic factors) were integrated to ensure the viability and sustainability of contract ventures. A sample of 70 ...

  16. Criteria for Viability Assessment of Discarded Human Donor Livers during Ex Vivo Normothermic Machine Perfusion

    NARCIS (Netherlands)

    Sutton, Michael E.; op den Dries, Sanna; Karimian, Negin; Weeder, Pepijn D.; de Boer, Marieke T.; Wiersema-Buist, Janneke; Gouw, Annette S. H.; Leuvenink, Henri G. D.; Lisman, Ton; Porte, Robert J.

    2014-01-01

    Although normothermic machine perfusion of donor livers may allow assessment of graft viability prior to transplantation, there are currently no data on what would be a good parameter of graft viability. To determine whether bile production is a suitable biomarker that can be used to discriminate

  17. The Family Farm in California. Final Report of the Small Farm Viability Project.

    Science.gov (United States)

    California State Office of Economic Development, Sacramento. Community Services Administration.

    Most of California's farms are relatively small, family run operations, and their future has been called into question by current agricultural trends. The Small Farm Viability Planning Project was initiated to identify obstacles to small farm economic viability and make recommendations to the state on policies and actions that might reduce these…

  18. Profitability and viability analyses of small-holder cocoa production ...

    African Journals Online (AJOL)

    The data collected were analyzed using descriptive statistics, Benefit Cost Ratio and Net Present Value at 10% discount rate. Results show that cocoa production is profitable and viable in the study area. Also, the three management systems are efficient and practicable. The NPV for owner managed was highest showing ...

  19. Viability of Cryptosporidium parvum during ensilage of perennial ryegrass.

    Science.gov (United States)

    Merry, R J; Mawdsley, J L; Brooks, A E; Davies, D R

    1997-01-01

    The survival of Cryptosporidium parvum during ensilage of perennial ryegrass was examined in laboratory silos with herbage prepared in one of three different ways; either untreated, inoculated with a strain of Lactobacillus plantarum or by direct acidification with formic acid. The pH values of all silages initially fell below 4.5, but only formic acid-treated silage remained stable at less than pH 4 after 106 d, with the pH of the untreated and inoculant-treated silages rising to above 6. The formic acid-treated silage had a high lactic acid concentration (109 g kg-1 dry matter (DM)) and low concentrations of propionic and butyric acids after 106 d. However, the untreated and inoculant-treated silages showed an inverse relationship, with low lactic acid concentrations and high concentrations of acetic, propionic and butyric acids. These silages also contained ammonia-N concentrations in excess of 9 g kg-1 DM. In terms of the viability of Cryptosporidium parvum oocysts very few differences were seen after 14 d of ensilage with ca 50% remaining viable, irrespective of treatment and total numbers had declined from the initial level of 5.9 x 10(4) to 1 x 10(4) g(-1) fresh matter. Total oocyst numbers remained approximately the same until the end of the ensiling period, with the percentage of viable oocysts declining to 46, 41 and 32% respectively for formic acid, inoculant and untreated silages. The results are discussed in terms of changes occurring during the silage fermentation, in particular the products which may influence the survival of Cryptosporidium and implications for agricultural practice and the health of silage fed livestock.

  20. Assessment of donor heart viability during ex vivo heart perfusion.

    Science.gov (United States)

    White, Christopher W; Ambrose, Emma; Müller, Alison; Li, Yun; Le, Hoa; Hiebert, Brett; Arora, Rakesh; Lee, Trevor W; Dixon, Ian; Tian, Ganghong; Nagendran, Jayan; Hryshko, Larry; Freed, Darren

    2015-10-01

    Ex vivo heart perfusion (EVHP) may facilitate resuscitation of discarded donor hearts and expand the donor pool; however, a reliable means of demonstrating organ viability prior to transplantation is required. Therefore, we sought to identify metabolic and functional parameters that predict myocardial performance during EVHP. To evaluate the parameters over a broad spectrum of organ function, we obtained hearts from 9 normal pigs and 37 donation after circulatory death pigs and perfused them ex vivo. Functional parameters obtained from a left ventricular conductance catheter, oxygen consumption, coronary vascular resistance, and lactate concentration were measured, and linear regression analyses were performed to identify which parameters best correlated with myocardial performance (cardiac index: mL·min(-1)·g(-1)). Functional parameters exhibited excellent correlation with myocardial performance and demonstrated high sensitivity and specificity for identifying hearts at risk of poor post-transplant function (ejection fraction: R(2) = 0.80, sensitivity = 1.00, specificity = 0.85; stroke work: R(2) = 0.76, sensitivity = 1.00, specificity = 0.77; minimum dP/dt: R(2) = 0.74, sensitivity = 1.00, specificity = 0.54; tau: R(2) = 0.51, sensitivity = 1.00, specificity = 0.92), whereas metabolic parameters were limited in their ability to predict myocardial performance (oxygen consumption: R(2) = 0.28; coronary vascular resistance: R(2) = 0.20; lactate concentration: R(2) = 0.02). We concluded that evaluation of functional parameters provides the best assessment of myocardial performance during EVHP, which highlights the need for an EVHP device capable of assessing the donor heart in a physiologic working mode.

  1. Detection and Viability of Lactococcus lactis throughout Cheese Ripening

    Science.gov (United States)

    Cocolin, Luca

    2014-01-01

    Recent evidences highlighted the presence of Lactococcus lactis during late cheese ripening. For this reason, the role of this microorganism, well known as dairy starter, should be reconsidered throughout cheese manufacturing and ripening. Thus, the main objective of this study was to develop a RT-qPCR protocol for the detection, quantification and determination of the viability of L. lactis in ripened cheese samples by direct analysis of microbial nucleic acids. Standard curves were constructed for the specific quantification of L. lactis in cheese matrices and good results in terms of selectivity, correlation coefficient and efficiency were obtained. Thirty-three ripened cheeses were analyzed and, on the basis of RNA analysis, twelve samples showed 106 to 108 CFU of L. lactis per gram of product, thirteen from 103 to 105 CFU/g, and in eight cheeses, L. lactis was not detected. Traditional plating on M17 medium led to loads ranging from 105 to 109 CFU/g, including the cheese samples where no L. lactis was found by RT-qPCR. From these cheeses, none of the colonies isolated on M17 medium was identified as L. lactis species. These data could be interpreted as a lack of selectivity of M17 medium where colony growth is not always related to lactococcal species. At the same time, the absence or low abundance of L. lactis isolates on M17 medium from cheese where L. lactis was detected by RT-qPCR support the hypothesis that L. lactis starter populations are mainly present in viable but not culturable state during ripening and, for this reason, culture-dependent methods have to be supplemented with direct analysis of cheese. PMID:25503474

  2. Regional population viability of grassland songbirds: Effects of agricultural management

    Science.gov (United States)

    Perlut, N.G.; Strong, A.M.; Donovan, T.M.; Buckley, N.J.

    2008-01-01

    Although population declines of grassland songbirds in North America and Europe are well-documented, the effect of local processes on regional population persistence is unclear. To assess population viability of grassland songbirds at a regional scale (???150,000 ha), we quantified Savannah Sparrow Passerculus sandwichensis and Bobolink Dolichonyx oryzivorus annual productivity, adult apparent survival, habitat selection, and density in the four most (regionally) common grassland treatments. We applied these data to a female-based, stochastic, pre-breeding population model to examine whether current grassland management practices can sustain viable populations of breeding songbirds. Additionally, we evaluated six conservation strategies to determine which would most effectively increase population trends. Given baseline conditions, over 10 years, simulations showed a slightly declining or stable Savannah Sparrow population (mean bootstrap ?? = 0.99; 95% CI = 1.00-0.989) and severely declining Bobolink population (mean bootstrap ?? = 0.75; 95% CI = 0.753-0.747). Savannah Sparrow populations were sensitive to increases in all demographic parameters, particularly adult survival. However for Bobolinks, increasing adult apparent survival, juvenile apparent survival, or preference by changing habitat selection cues for late-hayed fields (highest quality) only slightly decreased the rate of decline. For both species, increasing the amount of high-quality habitat (late- and middle-hayed) marginally slowed population declines; increasing the amount of low-quality habitat (early-hayed and grazed) marginally increased population declines. Both species were most sensitive to low productivity and survival on early-hayed fields, despite the fact that this habitat comprised only 18% of the landscape. Management plans for all agricultural regions should increase quality on both low- and high-quality fields by balancing habitat needs, nesting phenology, and species' response to

  3. Analysis of the competitive viability of independent middle distillate marketers

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-01

    The viability of the home heating oil dealer is being threatened by changes in the basic conditions of the middle distillate industry. These changes, which were examined over the study period from 1972 through 1978, are summarized below. (1) The overall number of households using home heating oil for space conditioning has declined from 1970 to 1976. This pattern has occurred in an expanding market. The Northeast Census Region is the only area of the country in which the number of households using heating oil shows a net increase. (2) The quantity of home heating oil consumed by the residential sector has declined by 8.3 percent between 1972 and 1977. (3) The average level of consumption per household has declined 5.9 percent from 1970 to 1976. (4) Demand for distillate fuel oil as diesel fuel for on- and off-highway use; for industrial and oil company consumption; for vessels, railroads, and all other uses, has increased 14.5 percent. (5) Total refining capacity that is capable of producing middle distillates has increased 17 percent. (6) Total annual distillate output has increased 18 percent from 1974 through 1978. (7) Prices for home heating oil increased by more than 150 percent from 1972 to 1977, compared with 93 percent for the less expensive natural gas. Home heating oil dealers face a declining market, both in terms of number of households using the product and in terms of sales per household. Although total middle distillate supplies were adequate during the time period studied, the demand for distillate fuel oil for uses other than home heating oil may eventually put pressure on supplies. That is, downward pressure on prices, expected when supplies outstrip demand, may not occur because of the many alternative uses for home heating oil.

  4. Multispectral imaging of organ viability during uterine transplantation surgery

    Science.gov (United States)

    Clancy, Neil T.; Saso, Srdjan; Stoyanov, Danail; Sauvage, Vincent; Corless, David J.; Boyd, Michael; Noakes, David E.; Thum, Meen-Yau; Ghaem-Maghami, Sadaf; Smith, J. R.; Elson, Daniel S.

    2014-02-01

    Uterine transplantation surgery has been proposed as a treatment for permanent absolute uterine factor infertility (AUFI) in the case of loss of the uterus. Due to the complexity of the vasculature correct reanastomosis of the blood supply during transplantation surgery is a crucial step to ensure reperfusion and viability of the organ. While techniques such as fluorescent dye imaging have been proposed to visualise perfusion there is no gold standard for intraoperative visualisation of tissue oxygenation. In this paper results from a liquid crystal tuneable filter (LCTF)-based multispectral imaging (MSI) laparoscope are described. The system was used to monitor uterine oxygen saturation (SaO2) before and after transplantation. Results from surgeries on two animal models (rabbits and sheep) are presented. A feature-based registration algorithm was used to correct for misalignment induced by breathing or peristalsis in the tissues of interest prior to analysis. An absorption spectrum was calculated at each spatial pixel location using reflectance data from a reference standard, and the relative contributions from oxy- and deoxyhaemoglobin were calculated using a least squares regression algorithm with non-negativity constraints. Results acquired during animal surgeries show that cornual oxygenation changes are consistent with those observed in point measurements taken using a pulse oximeter, showing reduced SaO2 following reanastomosis. Values obtained using the MSI laparoscope were lower than those taken with the pulse oximeter, which may be due to the latter's use of the pulsatile arterial blood signal. Future work incorporating immunological test results will help to correlate SaO2 levels with surgical outcomes.

  5. Spatial and Temporal Measurements of Temperature and Cell Viability in Response to Nanoparticle Mediated Photothermal Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, Jon R [ORNL; Rodgers, Amanda [Virginia Polytechnic Institute and State University; Harvie, Erica [Virginia Polytechnic Institute and State University; Carswell, William [Virginia Polytechnic Institute and State University; Torti, Suzy [Wake Forest University, Winston-Salem; Puretzky, Alexander A [ORNL; Rouleau, Christopher M [ORNL; Geohegan, David B [ORNL; Rylander, Christopher [Virginia Polytechnic Institute and State University; Rylander, Nichole M [Virginia Polytechnic Institute and State University

    2012-01-01

    Aim: Nanoparticle enhanced photothermal therapy is a promising alternative to tumor resection. However, quantitative measurements of cellular response to these treatments are limited. This paper introduces a Bimodal Enhanced Analysis of Spatiotemporal Temperature (BEAST) algorithm to rapidly determine the viability of cancer cells in vitro following photothermal therapy alone or in combination with nanoparticles. Materials & Methods: To illustrate the capability of the BEAST viability algorithm, single wall carbon nanohorns were added to renal cancer (RENCA) cells in vitro and time-dependent spatial temperature maps measured with an infrared camera during laser therapy were correlated with post-treatment cell viability distribution maps obtained by cell-staining fluorescent microscopy. Conclusion: The BEAST viability algorithm accurately and rapidly determined the cell viability as function of time, space, and temperature.

  6. LIVE/DEAD YEAST VIABILITY STAINING AS A TOOL FOR IMPROVING ARTISANAL PILSNER BEER PRODUCTION

    Directory of Open Access Journals (Sweden)

    Benedetta Bottari

    2014-10-01

    Full Text Available The production of an artisanal beer, made by brewers using traditional practices on a small scale, is founded on the empirical adjustment of parameters, including yeasts handling and serial repitching. The aim of this study was to monitor yeast viability during different stages of artisanal beer productions through the Live/Dead Yeast viability staining and to correlate it with fermentation dynamics in order to increase process standardization and to maintain the quality of final products. Yeast viability and fermentation activities were evaluated during seven fermentation cycles of an artisanal pilsner beer. Yeast inoculated with higher viability performed generally better in fermentation, resulting in faster sugar consumption, faster ethanol production and stability. Handling yeast and serial repitching based on Live/Dead viability measurements, could be the key way to ensure reliable manufacture of high quality beer and to improve process standardization particularly for microbreweries, where variability of production can be a challenging point.

  7. Pretreatment of algae-laden and manganese-containing waters by oxidation-assisted coagulation: Effects of oxidation on algal cell viability and manganese precipitation.

    Science.gov (United States)

    Lin, Jr-Lin; Hua, Lap-Cuong; Wu, Yuting; Huang, Chihpin

    2016-02-01

    Preoxidation is manipulated to improve performance of algae and soluble manganese (Mn) removal by coagulation-sedimentation for water treatment plants (WTPs) when large amount of soluble Mn presents in algae-laden waters. This study aimed to investigate the effects of preoxidation on the performance of coagulation-sedimentation for the simultaneous removal of algae and soluble Mn, including ionic and complexed Mn. NaOCl, ClO2, and KMnO4 were used to pretreat such algae-laden and Mn containing waters. The variation of algal cell viability, residual cell counts, and concentrations of Mn species prior to and after coagulation-sedimentation step were investigated. Results show that NaOCl dosing was effective in reducing the viability of algae, but precipitated little Mn. ClO2 dosing had a strongest ability to lower algae viability and oxidize ionic and complexed soluble Mn, where KMnO4 dosing oxidized ionic and complexed Mn instead of reducing the viability of cells. Preoxidation by NaOCl only improved the algae removal by sedimentation, whereas most of soluble Mn still remained. On the other hand, ClO2 preoxidation substantially improved the performance of coagulation-sedimentation for simultaneous removal of algae and soluble Mn. Furthermore, KMnO4 preoxidation did improve the removal of algae by sedimentation, but left significant residual Mn in the supernatant. Images from FlowCAM showed changes in aspect ratio (AR) and transparency of algae-Mn flocs during oxidation-assisted coagulation, and indicates that an effective oxidation can improve the removal of most compact algae-Mn flocs by sedimentation. It suggests that an effective preoxidation for reducing algal cell viability and the concentration of soluble Mn is a crucial step for upgrading the performance of coagulation-sedimentation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Inbreeding and parasite sex ratios.

    Science.gov (United States)

    Nee, Sean; West, Stuart A; Read, Andrew F

    2002-04-07

    The breeding system of parasitic protozoa affects the evolution of drug resistance and virulence, and is relevant to disease diagnosis and the development of chemo- and immunotherapy. A major group of protozoan parasites, the phylum Apicomplexa, that includes the aetiological agents of malaria, toxoplasmosis and coccidiosis, all have dimorphic sexual stages. The sex ratio (proportion of males produced by parasites) is predicted to depend upon the inbreeding rate, and it has been suggested that sex-ratio data offer a relatively cheap and easy method for indirectly estimating inbreeding rates. Here, we exploit a new theoretical machinery to show that there are generally valid relationships between f, Wright's coefficient of inbreeding, and sex ratio, z(*), the generality being with respect to population structure. To focus the discussion, we concentrate on malaria and show that the previously derived result, f = 1 - 2z(*), does not depend on the artificial assumptions about population structure that were previously made. Not only does this justify the use of sex ratio as an indirect measure of f, but also we argue that it may actually be preferable to measure f by measuring sex ratios, rather than by measuring departures from Hardy-Weinberg genotypic proportions both in malaria and parasites more generally.

  9. When does the lung die? Kfc, cell viability, and adenine nucleotide changes in the circulation-arrested rat lung.

    Science.gov (United States)

    Jones, D R; Becker, R M; Hoffmann, S C; Lemasters, J J; Egan, T M

    1997-07-01

    Lungs harvested from cadaveric circulation-arrested donors may increase the donor pool for lung transplantation. To determine the degree and time course of ischemia-reperfusion injury, we evaluated the effect of O2 ventilation on capillary permeability [capillary filtration coefficient (Kfc)], cell viability, and total adenine nucleotide (TAN) levels in in situ circulation-arrested rat lungs. Kfc increased with increasing postmortem ischemic time (r = 0.88). Lungs ventilated with O2 1 h postmortem had similar Kfc and wet-to-dry ratios as controls. Nonventilated lungs had threefold (P Kfc at 30 and 60 min postmortem compared with controls. Cell viability decreased in all groups except for 30-min postmortem O2-ventilated lungs. TAN levels decreased with increasing ischemic time, particularly in nonventilated lungs. Loss of adenine nucleotides correlated with increasing Kfc values (r = 0.76). This study indicates that lungs retrieved 1 h postmortem may have normal Kfc with preharvest O2 ventilation. The relationship between Kfc and TAN suggests that vascular permeability may be related to lung TAN levels.

  10. [Generation of a substitute for human oral mucosa and verification of its viability by tissue-engineering].

    Science.gov (United States)

    Marañés Gálvez, C; Liceras Liceras, E; Alaminos, M; Fernández Valadés, R; Ruiz Montes, A M; Garzón, I; Sánchez-Quevedo, M C; Campos, A

    2011-01-01

    Reconstruction of large oral mucosa defects is often challenging, since the shortage of healthy oral mucosa to replace the excised tissues. This way, tissue ingineering techniques may provide a source of autologous tissues available for transplant in these patients. In this work, we have developed a new model for artificial oral mucosa generated by tissue engineering using a fibrin-agarosa scaffold. For that purpose, we have generated primary cultures of human oral mucosa fibroblasts and keratinocytes from small biopsies of normal mucosa oral using enzymatic treatments. Then, we have determined the viability of cultured cells by electron probe quantitative X-ray microanalysis, and we have demonstrated that most of the cells in the primary cultures were alive and hd high K/Na ratios. Once cell viability was determined, we used cultured fibroblasts and keratinocytes to develop an artificial oral mucosa construct by using a fibrin-agarosa extracellular matrix and a sequential culture technique using porous culture inserts. Histological analysis of the artificial tissues showed high similarities with normal oral mucosa controls. The epithelium of the oral substitutes had several layers, with desmosomes and apical microvilli and microplicae. Both the controls and de oral mucosa substitutes showed high suprabasal expression of cytokeratin 13 and low expression of cytokeratin 10. All these results suggest that our model of oral mucosa using fibrin-agarose scaffolds show several similarities with native human oral mucosa.

  11. A Spectrophotometric Assay for Robust Viability Testing of Seed Batches Using 2,3,5-Triphenyl Tetrazolium Chloride: Using Hordeum vulgare L. as a Model

    Directory of Open Access Journals (Sweden)

    Laura Lopez Del Egido

    2017-05-01

    Full Text Available A comparative analysis was carried out of published methods to assess seed viability using 2,3,5-triphenyltetrazolium chloride (TTC based assays of seed batches. The tests were carried out on seeds of barley (Hordeum vulgare cv. Optic as a model. We established that 10% [w/v] trichloroacetic acid (TCA/methanol is superior to the acetone and methanol-only based methods: allowing the highest recovery of formazan and the lowest background optical density (OD readings, across seed lots comprising different ratios of viable and dead seeds. The method allowed a linear-model to accurately capture the statistically significant relationship between the quantity of formazan that could be extracted using the method we developed and the seed temperature-response, and seed viability as a function of artificially aged seed lots. Other quality control steps are defined to help ensure the assay is robust and these are reported in a Standard Operating Procedure.

  12. Monocarboxylate transporter 8 modulates the viability and invasive capacity of human placental cells and fetoplacental growth in mice.

    Directory of Open Access Journals (Sweden)

    Elisavet Vasilopoulou

    Full Text Available Monocarboxylate transporter 8 (MCT8 is a well-established thyroid hormone (TH transporter. In humans, MCT8 mutations result in changes in circulating TH concentrations and X-linked severe global neurodevelopmental delay. MCT8 is expressed in the human placenta throughout gestation, with increased expression in trophoblast cells from growth-restricted pregnancies. We postulate that MCT8 plays an important role in placental development and transplacental TH transport. We investigated the effect of altering MCT8 expression in human trophoblast in vitro and in a Mct8 knockout mouse model. Silencing of endogenous MCT8 reduced T3 uptake into human extravillous trophoblast-like cells (SGHPL-4; 40%, P<0.05 and primary cytotrophoblast (15%, P<0.05. MCT8 over-expression transiently increased T3 uptake (SGHPL-4∶30%, P<0.05; cytotrophoblast: 15%, P<0.05. Silencing MCT8 did not significantly affect SGHPL-4 invasion, but with MCT8 over-expression T3 treatment promoted invasion compared with no T3 (3.3-fold; P<0.05. Furthermore, MCT8 silencing increased cytotrophoblast viability (∼20%, P<0.05 and MCT8 over-expression reduced cytotrophoblast viability independently of T3 (∼20%, P<0.05. In vivo, Mct8 knockout reduced fetal:placental weight ratios compared with wild-type controls at gestational day 18 (25%, P<0.05 but absolute fetal and placental weights were not significantly different. The volume fraction of the labyrinthine zone of the placenta, which facilitates maternal-fetal exchange, was reduced in Mct8 knockout placentae (10%, P<0.05. However, there was no effect on mouse placental cell proliferation in vivo. We conclude that MCT8 makes a significant contribution to T3 uptake into human trophoblast cells and has a role in modulating human trophoblast cell invasion and viability. In mice, Mct8 knockout has subtle effects upon fetoplacental growth and does not significantly affect placental cell viability probably due to compensatory mechanisms in

  13. Population viability analysis of the Endangered shortnose sturgeon

    Energy Technology Data Exchange (ETDEWEB)

    Jager, Yetta [ORNL; Bevelhimer, Mark S [ORNL; Peterson, Douglas L. [University of Georgia, Athens, GA

    2011-07-01

    This study used population viability analysis (PVA) to partition the influences of potential threats to the endangered shortnose sturgeon (Acipenser brevirostrum). A workshop brought together experts to help identify potential threats including groundwater withdrawal, poor water quality, saltwater intrusion, mercury effects, harvest as by-catch, and sedimentation of spawning habitat. During the course of the project, we eliminated some threats and added new ones. Groundwater withdrawal was dismissed after a study failed to identify connection with groundwater and the majority of pumping is from a confined aquifer. We also eliminated activities on Fort Stewart as influences on spawning habitat because any successful spawning must occur upstream of Fort Stewart. We added climate change to the list of threats based on our assessment of temperature effects and expectations of sea-level rise. Our study highlighted the role of populations in nearby rivers in providing metapopulation support, raising the concern that the population in the Ogeechee River acts as a demographic sink. As part of this study, we carried out a field sampling study to analyze effects of training activities on headwater streams. We developed a new methodology for sampling design as part of this effort and used a mixed-modeling approach to identify relationships between land cover-land use, including those associated with military training activity and water quality. We found that tank training was associated with higher suspended sediment and equipment training was associated with higher organic carbon) and water quality. We detected effects of training on suspended sediment and organic carbon. We also carried out a field sampling effort in the Canoochee and Ogeechee Rivers. In the Ogeechee River, we found that dissolved oxygen in 40% of measurements during summer were below 4 mg L-1. To evaluate mercury as a potential threat, we developed a mercury uptake model and analyzed mercury levels in

  14. Proteomic Analysis of Silk Viability in Maize Inbred Lines and Their Corresponding Hybrids.

    Science.gov (United States)

    Ma, Zhihui; Qin, Yongtian; Wang, Yafei; Zhao, Xiaofeng; Zhang, Fangfang; Tang, Jihua; Fu, Zhiyuan

    2015-01-01

    A long period of silk viability is critical for a good seed setting rate in maize (Zea mays L.), especially for inbred lines and hybrids with a long interval between anthesis and silking. To explore the molecular mechanism of silk viability and its heterosis, three inbred lines with different silk viability characteristics (Xun928, Lx9801, and Zong3) and their two hybrids (Xun928×Zong3 and Lx9801×Zong3) were analyzed at different developmental stages by a proteomic method. The differentially accumulated proteins were identified by mass spectrometry and classified into metabolism, protein biosynthesis and folding, signal transduction and hormone homeostasis, stress and defense responses, and cellular processes. Proteins involved in nutrient (methionine) and energy (ATP) supply, which support the pollen tube growth in the silk, were important for silk viability and its heterosis. The additive and dominant effects at a single locus, as well as complex epistatic interactions at two or more loci in metabolic pathways, were the primary contributors for mid-parent heterosis of silk viability. Additionally, the proteins involved in the metabolism of anthocyanins, which indirectly negatively regulate local hormone accumulation, were also important for the mid-parent heterosis of silk viability. These results also might imply the developmental dependence of heterosis, because many of the differentially accumulated proteins made distinct contributions to the heterosis of silk viability at specific developmental stages.

  15. Proteomic Analysis of Silk Viability in Maize Inbred Lines and Their Corresponding Hybrids.

    Directory of Open Access Journals (Sweden)

    Zhihui Ma

    Full Text Available A long period of silk viability is critical for a good seed setting rate in maize (Zea mays L., especially for inbred lines and hybrids with a long interval between anthesis and silking. To explore the molecular mechanism of silk viability and its heterosis, three inbred lines with different silk viability characteristics (Xun928, Lx9801, and Zong3 and their two hybrids (Xun928×Zong3 and Lx9801×Zong3 were analyzed at different developmental stages by a proteomic method. The differentially accumulated proteins were identified by mass spectrometry and classified into metabolism, protein biosynthesis and folding, signal transduction and hormone homeostasis, stress and defense responses, and cellular processes. Proteins involved in nutrient (methionine and energy (ATP supply, which support the pollen tube growth in the silk, were important for silk viability and its heterosis. The additive and dominant effects at a single locus, as well as complex epistatic interactions at two or more loci in metabolic pathways, were the primary contributors for mid-parent heterosis of silk viability. Additionally, the proteins involved in the metabolism of anthocyanins, which indirectly negatively regulate local hormone accumulation, were also important for the mid-parent heterosis of silk viability. These results also might imply the developmental dependence of heterosis, because many of the differentially accumulated proteins made distinct contributions to the heterosis of silk viability at specific developmental stages.

  16. The basic study on application of optical coherence tomography to monitoring of viability in vivo rat brain

    Science.gov (United States)

    Sato, Manabu; Nonaka, Ippei; Kitano, Tetushi; Takahashi, Toshihiro; Nishidate, Izumi

    2013-08-01

    The relations and correlation coefficients (CCs) between the OCT signal and the modified state entropy (MSE) of electroencephalogram (EEG) have been studied. Three dimensional (3D) OCT images of rat brains through the thinned skull and EEG have been measured simultaneously anesthetizing to reduce brain activity with the quadrature fringe widefield OCT. Measured 3D volumes are 4mm × 4mm × 2.8mm (Depth). MSE is the product of state entropy of EEG and its effective value. Depth profiles were obtained at the selected three points on the surface of thinned skull. For chosen each depth, the relative signal intensity (RSI) is defined as the ratios of signal intensity to first signal intensity. Deepening the anesthesia RSI increased and MSE decreased to show negative correlation and CCs from -0.31 to -0.56. These results indicate enhancements of the feasibility of OCT as a tool for monitoring/diagnosing the brain tissue viability.

  17. Fluorescence Microscopy Methods for Determining the Viability of Bacteria in Association with Mammalian Cells

    Science.gov (United States)

    Johnson, M. Brittany; Criss, Alison K.

    2013-01-01

    Central to the field of bacterial pathogenesis is the ability to define if and how microbes survive after exposure to eukaryotic cells. Current protocols to address these questions include colony count assays, gentamicin protection assays, and electron microscopy. Colony count and gentamicin protection assays only assess the viability of the entire bacterial population and are unable to determine individual bacterial viability. Electron microscopy can be used to determine the viability of individual bacteria and provide information regarding their localization in host cells. However, bacteria often display a range of electron densities, making assessment of viability difficult. This article outlines protocols for the use of fluorescent dyes that reveal the viability of individual bacteria inside and associated with host cells. These assays were developed originally to assess survival of Neisseria gonorrhoeae in primary human neutrophils, but should be applicable to any bacterium-host cell interaction. These protocols combine membrane-permeable fluorescent dyes (SYTO9 and 4',6-diamidino-2-phenylindole [DAPI]), which stain all bacteria, with membrane-impermeable fluorescent dyes (propidium iodide and SYTOX Green), which are only accessible to nonviable bacteria. Prior to eukaryotic cell permeabilization, an antibody or fluorescent reagent is added to identify extracellular bacteria. Thus these assays discriminate the viability of bacteria adherent to and inside eukaryotic cells. A protocol is also provided for using the viability dyes in combination with fluorescent antibodies to eukaryotic cell markers, in order to determine the subcellular localization of individual bacteria. The bacterial viability dyes discussed in this article are a sensitive complement and/or alternative to traditional microbiology techniques to evaluate the viability of individual bacteria and provide information regarding where bacteria survive in host cells. PMID:24056524

  18. Cell motility, morphology, viability and proliferation in response to nanotopography on silicon black

    DEFF Research Database (Denmark)

    Lopacinska, Joanna M.; Gradinaru, Cristian; Wierzbicki, Rafal

    2012-01-01

    standard measurements of cell viability, proliferation, and morphology on various surfaces. We also analyzed the motility of cells on the same surfaces, as recorded in time lapse movies of sparsely populated cell cultures. We find that motility and morphology vary strongly with nano-patterns, while...... viability and proliferation show little dependence on substrate type. We conclude that motility analysis can show a wide range of cell responses e. g. over a factor of two in cell speed to different nano-topographies, where standard assays, such as viability or proliferation, in the tested cases show much...

  19. Improvement In Rabbit Corneal Cell Suspension Viability After Freezing With Gingko Biloba Extrakt

    Directory of Open Access Journals (Sweden)

    Murad Aktan

    2007-01-01

    Full Text Available We investigated whether the addition of Gingko Biloba extract (EGb 761 to rabbit corneal epithelial medium before cell freezing improved cell viability after freezing then thawing. After removal of corneas, they were treated with enzymes and the corneal epithelium was prepared as a single cell suspension in freezing media with or without EGb 761. After freezing for two weeks then thawing, a higher cell viability was found in the cornea cell suspensions which had been frozen pretreated with EGb 761 in the media. The improvement with corneal cell viability with EGb 761 pretreatment is postulated to be based on the antioxidant capacity of the plant extract.

  20. Inbreeding and parasite sex ratios

    OpenAIRE

    Nee, Sean; West, Stuart A; Read, Andrew F.

    2002-01-01

    The breeding system of parasitic protozoa affects the evolution of drug resistance and virulence, and is relevant to disease diagnosis and the development of chemo- and immunotherapy. A major group of protozoan parasites, the phylum Apicomplexa, that includes the aetiological agents of malaria, toxoplasmosis and coccidiosis, all have dimorphic sexual stages. The sex ratio (proportion of males produced by parasites) is predicted to depend upon the inbreeding rate, and it has been suggested tha...

  1. Spectacle dispensing in Timor-Leste: tiered-pricing, cross-subsidization and financial viability.

    Science.gov (United States)

    Ramke, Jacqueline; Brian, Garry; Palagyi, Anna

    2012-08-01

    To examine the financial viability of the Timor-Leste National Spectacle Program as it increases spectacle availability, affordability and uptake, particularly for Timor's poor. In rural areas, three models of ready-made spectacles were dispensed according to a tiered pricing structure of US$3.00, 1.00, 0.10 and 0.00. In addition, custom-made spectacles were available in the capital, Dili. Spectacle costs, dispensing data and income for the National Spectacle Program for 18 months from March 2007 were analyzed. Rural services dispensed 3415 readymade spectacles: 47.1% to women, and 51.4% at subsidized prices, being 39.8% at US$0.10 and 11.6% free. A profit of US$1,529 was generated, mainly from the sale of US$3.00 spectacles. Women (odds ratio, OR, 1.3, 95% confidence interval, CI, 1.1-1.4) and consumers aged ≥65 years (OR 2.1; 95% CI 1.7-2.6) were more likely to receive subsidized spectacles. Urban services dispensed 2768 spectacles; mostly US$3.00 readymade (52.8%) and custom-made single vision (29.6%) units. Custom-made spectacles accounted for 36.7% of dispensing, but 73.1% of the US$12,264 urban profit. The combined rural and urban profit covered all rural costs, leaving US$2,200 to meet administration and other urban expenses. It is instructive and encouraging that a national spectacle dispensing program in one of the ten poorest countries of the world can use tiered-pricing based on willingness-to-pay information to cover spectacle stock replacement costs and produce profit, while using cross-subsidization to provide spectacles to the poor.

  2. TRAPPING PROTOCOLS, SAMPLING, AND VIABILITY ANALYSES FOR THE ALABAMA BEACH MICE (PEROMYSCUS POLIONOTUS AMMOBATES): FINAL REPORT

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We performed a comprehensive critique of trapping protocols, data analysis, and population viability analyses conducted to date for the Alabama beach mouse...

  3. Microencapsulation in alginate and chitosan microgels to enhance viability of Bifidobacterium longum for oral delivery

    Directory of Open Access Journals (Sweden)

    Timothy W. Yeung

    2016-04-01

    Full Text Available Probiotic microorganisms are incorporated into a wide variety of foods, supplements, and pharmaceuticals to promote human health and wellness. However, maintaining bacterial cell viability during storage and gastrointestinal transit remains a challenge. Encapsulation of bifidobacteria within food-grade hydrogel particles potentially mitigates their sensitivity to environmental stresses. In this study, Bifidobacterium longum subspecies and strains were encapsulated in core-shell microgels consisting of an alginate core and a microgel shell. Encapsulated obligate anaerobes Bifidobacterium longum subsp. infantis and Bifidobacterium longum subsp. longum exhibited differences in viability in a strain-dependent manner, without a discernable relationship to subspecies lineage. This includes viability under aerobic storage conditions and modeled gastrointestinal tract conditions. Coating alginate microgels with chitosan did not improve viability compared to cells encapsulated in alginate microgels alone, suggesting that modifying the surface charge alone does not enhance delivery. Thus hydrogel beads have great potential for improving the stability and efficacy of bifidobacterial probiotics in various nutritional interventions.

  4. Microfluidic high viability neural cell separation using viscoelastically tuned hydrodynamic spreading

    DEFF Research Database (Denmark)

    Wu, Zhigang; Hjort, Klas; Wicher, Grzegorz

    2008-01-01

    A high viability microfluidic cell separation technique of high throughput was demonstrated based on size difference continuous mode hydrodynamic spreading with viscoelastic tuning. Using water with fluorescent dye as sample fluid and in parallel introducing as elution a viscoelastic biocompatible...

  5. The Effect of Disinfection on Viability and Function of Baboon Red Blood Cells and Platelets

    National Research Council Canada - National Science Library

    Valeri, C

    1997-01-01

    .... For the past 10 years our laboratory has used baboons to evaluate the effects of various disinfection treatments on autologous red blood cell and platelet viability and function in vitro and in vivo...

  6. Recent developments in the use of viability dyes and quantitative PCR in the food microbiology field

    National Research Council Canada - National Science Library

    Elizaquível, P; Aznar, R; Sánchez, G

    2014-01-01

    .... Moreover, those dyes have been explored to monitor different food manufacturing processes as an alternative to classical cultural methods. In this review, state‐of‐the‐art information regarding viability PCR (v‐PCR) is compiled.

  7. Influence of harvesting and processing methods on organic viability of soybean seed

    Directory of Open Access Journals (Sweden)

    Đukanović Lana

    2000-01-01

    Full Text Available Organic viability of soybean seed for three soybean varieties - elite (Bosa, ZPS 015 and Nena depending on methods of manipulation with seeds during harvesting and processing phase were determined in this paper. Trial was conducted in Zemun Polje during 1999; manual and mechanized harvesting or processing methods were applied. Seed germination was tested using ISTA methods (Standard method and Cold test. Following parameters were evaluated: germination viability, germination, rate-speed of emergence, length of hypocotile and main root Rate-speed of emergence was based on number of emerged plants per day. Length of hypocotile or root and percent of germination determined vigour index. Based on obtained results it maybe concluded that methods of seed manipulation during harvesting or processing phase were influenced on soybean seed quality parameters evaluated. Ways of seed manipulation - methods evaluated were influenced organic viability of soybean seed by decreasing germination viability, total germination and length of main root.

  8. Loss of rachis cell viability is associated with ripening disorders in grapes

    OpenAIRE

    Hall, Geoffrey E.; Bondada, Bhaskar R.; Keller, Markus

    2010-01-01

    Rachises of grape (Vitis vinifera L.) clusters that appeared healthy or displayed symptoms of the ripening disorders berry shrivel (BS) or bunch-stem necrosis (BSN) were treated with the cellular viability stain fluorescein diacetate and examined by confocal microscopy. Clusters with BS and BSN symptoms experienced a decrease of cell viability throughout the rachis, and their berries contained 70–80% less sugar than healthy berries. The xylem-mobile dye basic fuchsin, infiltrated via the cut ...

  9. Fluorescence techniques to detect and to assess viability of plant pathogenic bacteria

    OpenAIRE

    Chitarra, L.G.

    2001-01-01

    Plant pathogenic bacteria cause major economic losses in commercial crop production worldwide every year. The current methods used to detect and to assess the viability of bacterial pathogens and to test seed lots or plants for contamination are usually based on plate assays or on serological techniques. Plating methods provide information about cell viability, but are generally laborious and time-consuming. Serological techniques, such as immunofluorescence microscopy (IF) and enzym...

  10. Cell adhesion and viability of human endothelial cells on electrospun polymer scaffolds

    OpenAIRE

    Matschegewski Claudia; Matthies Jörn-Bo; Grabow Niels; Schmitz Klaus-Peter

    2016-01-01

    The usage of electrospun polymer scaffolds is a promising approach for artificial heart valve design. This study aims at the evaluation of biological performance of nanofibrous polymer scaffolds poly(L-lactide) PLLA L210, PLLA L214 and polyamide-6 fabricated by electrospinning via analyzing viability, adhesion and morphology of human umbilical vein endothelial cells (EA.hy926). Nanofibrous surface topography was shown to influence cell phenotype and cell viability according to the observation...

  11. Sex ratio bias and extinction risk in an isolated population of Tuatara (Sphenodon punctatus.

    Directory of Open Access Journals (Sweden)

    Kristine L Grayson

    Full Text Available Understanding the mechanisms underlying population declines is critical for preventing the extinction of endangered populations. Positive feedbacks can hasten the process of collapse and create an 'extinction vortex,' particularly in small, isolated populations. We provide a case study of a male-biased sex ratio creating the conditions for extinction in a natural population of tuatara (Sphenodon punctatus on North Brother Island in the Cook Strait of New Zealand. We combine data from long term mark-recapture surveys, updated model estimates of hatchling sex ratio, and population viability modeling to measure the impacts of sex ratio skew. Results from the mark-recapture surveys show an increasing decline in the percentage of females in the adult tuatara population. Our monitoring reveals compounding impacts on female fitness through reductions in female body condition, fecundity, and survival as the male-bias in the population has increased. Additionally, we find that current nest temperatures are likely to result in more male than female hatchlings, owing to the pattern of temperature-dependent sex determination in tuatara where males hatch at warmer temperatures. Anthropogenic climate change worsens the situation for this isolated population, as projected temperature increases for New Zealand are expected to further skew the hatchling sex ratio towards males. Population viability models predict that without management intervention or an evolutionary response, the population will ultimately become entirely comprised of males and functionally extinct. Our study demonstrates that sex ratio bias can be an underappreciated threat to population viability, particularly in populations of long-lived organisms that appear numerically stable.

  12. Soy milk as a storage medium to preserve human fibroblast cell viability: an in vitro study.

    Science.gov (United States)

    Moura, Camilla Christian Gomes; Soares, Priscilla Barbosa Ferreira; Reis, Manuella Verdinelli de Paula; Fernandes Neto, Alfredo Júlio; Soares, Carlos José

    2012-01-01

    Soy milk (SM) is widely consumed worldwide as a substitute for cow milk. It is a source of vitamins, carbohydrates and sugars, but its capacity to preserve cell viability has not been evaluated. The purpose of the present study was to investigate the efficacy of SM to maintain the viability of human fibroblasts at short periods compared with different cow milks. Human mouth fibroblasts were cultured and stored in the following media at room temperature: 10% Dulbecco's Modified Eagle Medium (DMEM) (positive control group); long shelf-life ultra-high temperature whole cow milk (WM); long shelf-life ultra-high temperature skim cow milk (SKM); powdered cow milk (PM); and soy milk (SM). After 5, 15, 30 and 45 min, cell viability was analyzed using the MTT assay. Data were analyzed statistically by the Kruskal-Wallis test with post-analysis using the Dunn's method (α=0.05). SKM showed the lowest capacity to maintain cell viability in all analyzed times (p<0.05). At 30 and 45 min, the absorbance levels in control group (DMEM) and SM were significantly higher than in SKM (p<0.05). Cell viability decreased along the time (5-45 min). The results indicate that SM can be used as a more adequate storage medium for avulsed teeth. SKM was not as effective in preserving cell viability as the cell culture medium and SM.

  13. Prediction of viability of leek (Allium porrum seeds by a new test

    Directory of Open Access Journals (Sweden)

    I. Güvenç

    2013-12-01

    Full Text Available The objective of this research was to determine the suitability of boiling water test in the prediction of seed viability in leek seed and to compare this test with standard germination and vigour test. Basic principle of boiling water test is the evaluation of radicle protrusion from the seeds immersed to boiling water for certain time. The viability of aged and unaged leek seeds in boiling water test was correlated with standard germination and vigour test. In this research. the mean germination of unaged leek seeds varied from 29,639% to 70,18% depending on the cultivars. While the range of boiling water test in unaged leek seeds was between 35.57% to 51,06%, the range for emergence was between 27,63% to 72,05%. The viability of aged and unaged leek seeds in boiling water test was correlated with standard germination test. According to the results of this research, it might be assessed that boiling water test is a rapid and simple method to measure seed viability by evaluating radicle protrusion of leek seeds in boiling water. In conclusion. boiling water test as a new viability test for leek seed could be used as a rapid method for determining the viability in leek seeds.

  14. Non-invasive imaging in detecting myocardial viability: Myocardial function versus perfusion

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    Iqbal A. Elfigih

    2014-12-01

    Full Text Available Coronary artery disease (CAD is the most prevalent and single most common cause of morbidity and mortality [1] with the resulting left ventricular (LV dysfunction an important complication. The distinction between viable and non-viable myocardium in patients with LV dysfunction is a clinically important issue among possible candidates for myocardial revascularization. Several available non-invasive techniques are used to detect and assess ischemia and myocardial viability. These techniques include echocardiography, radionuclide images, cardiac magnetic resonance imaging and recently myocardial computed tomography perfusion imaging. This review aims to distinguish between the available non-invasive imaging techniques in detecting signs of functional and perfusion viability and identify those which have the most clinical relevance in detecting myocardial viability in patients with CAD and chronic ischemic LV dysfunction. The most current available studies showed that both myocardial perfusion and function based on non-invasive imaging have high sensitivity with however wide range of specificity for detecting myocardial viability. Both perfusion and function imaging modalities provide complementary information about myocardial viability and no optimum single imaging technique exists that can provide very accurate diagnostic and prognostic viability assessment. The weight of the body of evidence suggested that non-invasive imaging can help in guiding therapeutic decision making in patients with LV dysfunction.

  15. IN VITRO ASSESSMENT OF EXPOSURE TO NONYLPHENOL ON VIABILITY OF BOVINE SPERMATOZOA

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    Jana Lukáčová

    2014-02-01

    Full Text Available Nonylphenol (NP is a toxic xenobiotic compound classified as an endocrine disruptor that bioaccumulates in the body and causes endocrine disruption. NP can result in male reproductive dysfunction, altered testicular development and decreased male fertility. The target of this in vitro study was to determine the effect of NP as an endocrine disruptor on the viability of spermatozoa. We examined the dose- and time-dependent effect of nonylphenol (1, 10, 100 and 200 µg/mL dissolved either in 0.1% dimethyl sulfoxide (DMSO and 0.1% ethanol on the viability of bovine spermatozoa after 6 h of in vitro cultivation. The viability of bovine spermatozoa was detected by the MTT cytotoxicity assay. The viability in groups with NP dissolved in 0.1% DMSO was significantly (P 10 µg/mL of NP and was decreased significantly (P<0.001 in all experimental groups with NP dissolved in 0.1% ethanol. After 6 h of culture the MTT assay proved a negative effect of all NP doses on the cell viability. The lowest survival of spermatozoa was determined after the addition of 200 µg/mL of NP. The obtained data indicate that the negative effect of NP on the viability must be seriously considered in the case of exposure to NP in animals and humans.

  16. Cardiac magnetic resonance for the assessment of myocardial viability: from pathophysiology to clinical practice.

    Science.gov (United States)

    Dellegrottaglie, Santo; Guarini, Pasquale; Savarese, Gianluigi; Gambardella, Francesco; Lo Iudice, Francesco; Cirillo, Annapaola; Vitagliano, Alice; Formisano, Tiziana; Pellegrino, Angela M; Bossone, Eduardo; Perrone-Filardi, Pasquale

    2013-12-01

    Cardiac magnetic resonance (CMR) is commonly applied for the assessment of myocardial viability in patients with ischemic ventricular dysfunction, and it holds potential advantages over more traditional imaging modalities, including single-photon emission computed tomography (SPECT) and dobutamine stress echocardiography (DSE). CMR-based techniques for viability assessment include the evaluation of transmural extent of the scar using late gadolinium enhancement (LGE) images, the evaluation of end-diastolic wall thickness from resting cine images and the study of inotropic reserve during low-dose dobutamine infusion. During the past decade, the diffusion of the use of CMR for viability assessment confirmed the clinical strengths of this modality and, at the same time, helped to use old techniques with an increased level of awareness. With LGE CMR, both viable and nonviable dysfunctional myocardium can be visualized in a single image, allowing a direct quantification of the amount of regional viability, with a significant impact on the estimation of chance for recovery. As well, studies with CMR applied in the setting of ischemic heart disease allowed a better understanding of the best way to apply and interpret other tests for viability evaluation. For instance, it has been demonstrated that the transmural extension of the scar may influence the level of concordance between SPECT and DSE in assessing myocardial viability. The transmural extent of scar on LGE CMR also correlates with the timing of postrevascularization recovery of systolic function, with significant impact on the diagnostic accuracy of any applied imaging modality.

  17. Viability of commercial wine yeasts during freezer storage in glycerol-based media.

    Science.gov (United States)

    Sidari, R; Caridi, A

    2009-01-01

    Glycerol-based medium (BM) with and without the addition of 1 g/L ascorbic acid (Asc) and/or 100 mg/L (+/-)-catechin (Cat) was tested for the storage of three commercial wine yeasts at -20 degrees C. The medium supplemented with Asc was also used to store 706 strains to verify the maintenance of the liquid state. A decline in survival throughout the storage period was observed. The media containing Asc maintained viability better than the other three. The BM caused a loss of viability of 7 orders for one strain and of 6 orders for the other two. All three strains exhibited a loss of viability of 4 orders when stored in BM+Asc. Two strains decreased viability by 5 orders while one strain by 4 orders, when stored in BM+Cat. Two strains decreased viability by 6 orders while one strain by 5 orders, when stored in BM+Asc+Cat. Regarding the physical state of the medium tested on 706 yeast strains, three cases were observed: completely liquid (56.5 %), liquid with only the upper part frozen (40.4 %) without involving the yeast biomass settled at the bottom, and completely frozen (3.12 %). It is practicable to prepare a BM that remains liquid at -20 degrees C enhancing yeast viability when Asc is added as cryoprotectant.

  18. Measuring Economies of Size with Expense Ratios

    OpenAIRE

    Langemeier, Michael R.

    2013-01-01

    This paper examines the relationship between three expense ratios: total expense ratio; adjusted total expense ratio; and economic total expense ratio; and discusses economies of size for a sample of Kansas farms. The total expense ratio and the adjusted total expense ratios, though commonly used to examine financial efficiency, are not as good of indicators of economies of size as the economic total expense ratio which includes opportunity costs on unpaid operator and family labor, and farm ...

  19. Odds ratios deconstructed: A new way to understand and explain odds ratios as conditional risk ratios.

    Science.gov (United States)

    Hoppe, Fred M; Hoppe, Daniel J; Walter, Stephen D

    2017-02-01

    The aim of this analysis was to provide an alternative derivation of the odds ratio (OR) to provide an intuitive meaning, freeing it from any mention of odds, which may make it a more useful concept for clinicians to use when describing treatment effect. By examining the four possible combinations of treatment/control and corresponding outcomes, we considered the conditional risk ratio (RR, also known as relative risk) of an event with the treatment compared with an event with the control for pairs of patients for whom treatment and control would yield different results. Both matched and unmatched studies are considered. We found that the OR could be derived as the RR of an outcome with treatment compared with an outcome with control conditional on the treatment and control resulting in different outcomes, thus providing a measure of the net benefit of treatment. It has been claimed that the OR comparing the effect of treatment vs. control does not have the same clinical interpretability as RR because it involves ratios of odds and so is difficult to explain in terms of patient numbers. This new derivation provides an interpretation of the OR as an RR but conditional on treatment and control resulting in different outcomes. This may help explain the reason ORs cause interpretation difficulties in practice. Moreover, the OR may be a more clinically useful parameter to patients because it deals with only those situations where the outcome differs between the two groups. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. GOLD and the fixed ratio

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    Vestbo J

    2012-09-01

    Full Text Available Jørgen VestboUniversity of Manchester, Manchester, UKI read with interest the paper entitled "Diagnosis of airway obstruction in the elderly: contribution of the SARA study" by Sorino et al in a recent issue of this journal.1 Being involved in the Global Initiative for Obstructive Lung Diseases (GOLD, it is nice to see the interest sparked by the GOLD strategy document. However, in the paper by Sorino et al, there are a few misunderstandings around GOLD and the fixed ratio (forced expiratory volume in 1 second/forced volume vital capacity < 0.70 that need clarification.View original paper by Sorino and colleagues.

  1. Ratio Bias and Policy Preferences

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Tue

    2016-01-01

    Numbers permeate modern political communication. While current scholarship on framing effects has focused on the persuasive effects of words and arguments, this article shows that framing of numbers can also substantially affect policy preferences. Such effects are caused by ratio bias, which...... regarding salient political issues such as education and taxes. Furthermore, the effects of numerical framing are found across most groups of the population, largely regardless of their political predisposition and their general ability to understand and use numerical information. These findings have...

  2. Why is the subendocardium more vulnerable to ischemia? A new paradigm

    Science.gov (United States)

    Algranati, Dotan; Kassab, Ghassan S.

    2011-01-01

    Myocardial ischemia is transmurally heterogeneous where the subendocardium is at higher risk. Stenosis induces reduced perfusion pressure, blood flow redistribution away from the subendocardium, and consequent subendocardial vulnerability. We propose that the flow redistribution stems from the higher compliance of the subendocardial vasculature. This new paradigm was tested using network flow simulation based on measured coronary anatomy, vessel flow and mechanics, and myocardium-vessel interactions. Flow redistribution was quantified by the relative change in the subendocardial-to-subepicardial perfusion ratio under a 60-mmHg perfusion pressure reduction. Myocardial contraction was found to induce the following: 1) more compressive loading and subsequent lower transvascular pressure in deeper vessels, 2) consequent higher compliance of the subendocardial vasculature, and 3) substantial flow redistribution, i.e., a 20% drop in the subendocardial-to-subepicardial flow ratio under the prescribed reduction in perfusion pressure. This flow redistribution was found to occur primarily because the vessel compliance is nonlinear (pressure dependent). The observed thinner subendocardial vessel walls were predicted to induce a higher compliance of the subendocardial vasculature and greater flow redistribution. Subendocardial perfusion was predicted to improve with a reduction of either heart rate or left ventricular pressure under low perfusion pressure. In conclusion, subendocardial vulnerability to a acute reduction in perfusion pressure stems primarily from differences in vascular compliance induced by transmural differences in both extravascular loading and vessel wall thickness. Subendocardial ischemia can be improved by a reduction of heart rate and left ventricular pressure. PMID:21169398

  3. Hydrostatic Compress Force Enhances the Viability and Decreases the Apoptosis of Condylar Chondrocytes through Integrin-FAK-ERK/PI3K Pathway

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    Dandan Ma

    2016-11-01

    Full Text Available Reduced mechanical stimuli in many pathological cases, such as hemimastication and limited masticatory movements, can significantly affect the metabolic activity of mandibular condylar chondrocytes and the growth of mandibles. However, the molecular mechanisms for these phenomena remain unclear. In this study, we hypothesized that integrin-focal adhesion kinase (FAK-ERK (extracellular signal–regulated kinase/PI3K (phosphatidylinositol-3-kinase signaling pathway mediated the cellular response of condylar chondrocytes to mechanical loading. Primary condylar chondrocytes were exposed to hydrostatic compressive forces (HCFs of different magnitudes (0, 50, 100, 150, 200, and 250 kPa for 2 h. We measured the viability, morphology, and apoptosis of the chondrocytes with different treatments as well as the gene, protein expression, and phosphorylation of mechanosensitivity-related molecules, such as integrin α2, integrin α5, integrin β1, FAK, ERK, and PI3K. HCFs could significantly increase the viability and surface area of condylar chondrocytes and decrease their apoptosis in a dose-dependent manner. HCF of 250 kPa resulted in a 1.51 ± 0.02-fold increase of cell viability and reduced the ratio of apoptotic cells from 18.10% ± 0.56% to 7.30% ± 1.43%. HCFs could significantly enhance the mRNA and protein expression of integrin α2, integrin α5, and integrin β1 in a dose-dependent manner, but not ERK1, ERK2, or PI3K. Instead, HCF could significantly increase phosphorylation levels of FAK, ERK1/2, and PI3K in a dose-dependent manner. Cilengitide, the potent integrin inhibitor, could dose-dependently block such effects of HCFs. HCFs enhances the viability and decreases the apoptosis of condylar chondrocytes through the integrin-FAK-ERK/PI3K pathway.

  4. Factors determining the viability of radiation processing in developing countries

    Science.gov (United States)

    van der Linde, HJ; Basson, RA

    In the fifteen years since the introduction of radiation processing to South Africa, four commercial irradiation facilities have been established. These are involved in the processing of a large variety of products, from syringes and prostheses to strawberries and sugar yeast. Three of the facilities are devoted mainly to food irradiation and several thousand tonnes are now processed annually. During this period it was repeatedly experienced that the successful introduction of radiation processing in general, and food radurization in particular, on a commercial scale was critically dependent on the following factors: acceptance by the producer, industry and consumer; initial capital expenditure; running costs and overheads in general; and continous throughput. All of these factors contribute to the processing cost which is the ultimate factor in determing the value/price ratio for the potential entrepreneur and customer of this new technology. After a market survey had identified the need for a new food irradiation facility to cope with the growing interest in commercial food radurization in the Western Cape, the above-mentioned factors were of cardinal importance in the design and manufacture of a new irradiator. The resulting batch-pallet facility which was commisioned in August 1986, is rather inefficient as far as energy utilization is concerned but this shortcoming is compensated for by its low cost, versatility and low hold-up. Although the facility has limitations as far as the processing of really large volumes of produce is concerned, it is particularly suitable not only for developing countries, but for developed countries in the introductory phase of commercial food radurization.

  5. Central hemodynamics are associated with cardiovascular disease and albuminuria in type 1 diabetes

    DEFF Research Database (Denmark)

    Theilade, Simone; Hansen, Tine W; Rossing, Peter

    2014-01-01

    BACKGROUND: We sought to investigate associations between central hemodynamic parameters (estimated from radial pulse wave analyses (PWAs)), cardiovascular disease (CVD), and albuminuria in type 1 diabetes. METHODS: We conducted an observational study of 636 type 1 diabetes patients. Central...... hemodynamics were measured by PWA as central aortic systolic pressure (CASP), central aortic pulse pressure (CPP), central aortic diastolic pressure (CADP), and subendocardial viability ratio (SEVR). CVD included revascularization, myocardial infarction, peripheral arterial disease, and stroke. Albuminuria...... models, increased CASP and CPP and decreased CADP and SEVR were associated with presence of CVD (n = 132; P ≤ 0.02) and presence of albuminuria (n = 335; P

  6. The genealogy and genetic viability of reintroduced Yellowstone grey wolves.

    Science.gov (United States)

    Vonholdt, Bridgett M; Stahler, Daniel R; Smith, Douglas W; Earl, Dent A; Pollinger, John P; Wayne, Robert K

    2008-01-01

    The recovery of the grey wolf in Yellowstone National Park is an outstanding example of a successful reintroduction. A general question concerning reintroduction is the degree to which genetic variation has been preserved and the specific behavioural mechanisms that enhance the preservation of genetic diversity and reduce inbreeding. We have analysed 200 Yellowstone wolves, including all 31 founders, for variation in 26 microsatellite loci over the 10-year reintroduction period (1995-2004). The population maintained high levels of variation (1995 H(0) = 0.69; 2004 H(0) = 0.73) with low levels of inbreeding (1995 F(IS) = -0.063; 2004 F(IS) = -0.051) and throughout, the population expanded rapidly (N(1995) = 21; N(2004) = 169). Pedigree-based effective population size ratios did not vary appreciably over the duration of population expansion (1995 N(e)/N(g) = 0.29; 2000 N(e)/N(g) = 0.26; 2004 N(e)/N(g) = 0.33). We estimated kinship and found only two of 30 natural breeding pairs showed evidence of being related (average r = -0.026, SE = 0.03). We reconstructed the genealogy of 200 wolves based on genetic and field data and discovered that they avoid inbreeding through a wide variety of behavioural mechanisms including absolute avoidance of breeding with related pack members, male-biased dispersal to packs where they breed with nonrelatives, and female-biased subordinate breeding. We documented a greater diversity of such population assembly patterns in Yellowstone than previously observed in any other natural wolf population. Inbreeding avoidance is nearly absolute despite the high probability of within-pack inbreeding opportunities and extensive interpack kinship ties between adjacent packs. Simulations showed that the Yellowstone population has levels of genetic variation similar to that of a population managed for high variation and low inbreeding, and greater than that expected for random breeding within packs or across the entire breeding pool. Although short

  7. CONSERVATION OF THE VIABILITY AND VIGOR OF Araucaria angustifolia (Bert. O. Kuntze SEEDS DURING THE STORAGE

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    Cristhyane Garcia

    2014-12-01

    Full Text Available The conservation of Araucaria seeds is widely compromised in function of their recalcitrant feature, which hampers the planning of recovery actions of the degraded populations. Therefore, the objective of this study was to monitor the physiological changes in Araucaria seeds under controlled storage conditions, in order to get insights as to the viability and vigor conservation. The physiological quality of freshly harvested seeds was evaluated and every 60 days throughout the 180 days-storage period in laboratory ambient without thermal control, refrigerator (5 ° C, and freezer (-18 ° C until the final period of 180 days. After each sampling period, the seed viability (germination and tetrazolium tests and vigor (artificial aging, germination speed index – IVG and electrical conductivity were assessed. A reduction in the normal seedlings percentage was noticed over the period of storage of Araucaria seeds. The conservation in freezer and the lack of thermal control caused a complete loss of the seed viability at 60 and 180 days of storage, respectively. However, the refrigerator storage promoted the conservation of seed viability, with 64% germination after 180 days of storage, an event associated with the reduction of the metabolic activity of seeds. Based on the viability and vigor tests, it was concluded that storage in refrigerator provided longer storage periods to Araucaria seeds in comparison to the other storage conditions herein studied.

  8. Lactate as a novel quantitative measure of viability in Schistosoma mansoni drug sensitivity assays.

    Science.gov (United States)

    Howe, Stephanie; Zöphel, Dorina; Subbaraman, Harini; Unger, Clemens; Held, Jana; Engleitner, Thomas; Hoffmann, Wolfgang H; Kreidenweiss, Andrea

    2015-02-01

    Whole-organism compound sensitivity assays are a valuable strategy in infectious diseases to identify active molecules. In schistosomiasis drug discovery, larval-stage Schistosoma allows the use of a certain degree of automation in the screening of compounds. Unfortunately, the throughput is limited, as drug activity is determined by manual assessment of Schistosoma viability by microscopy. To develop a simple and quantifiable surrogate marker for viability, we targeted glucose metabolism, which is central to Schistosoma survival. Lactate is the end product of glycolysis in human Schistosoma stages and can be detected in the supernatant. We assessed lactate as a surrogate marker for viability in Schistosoma drug screening assays. We thoroughly investigated parameters of lactate measurement and performed drug sensitivity assays by applying schistosomula and adult worms to establish a proof of concept. Lactate levels clearly reflected the viability of schistosomula and correlated with schistosomulum numbers. Compounds with reported potencies were tested, and activities were determined by lactate assay and by microscopy. We conclude that lactate is a sensitive and simple surrogate marker to be measured to determine Schistosoma viability in compound screening assays. Low numbers of schistosomula and the commercial availability of lactate assay reagents make the assay particularly attractive to throughput approaches. Furthermore, standardization of procedures and quantitative evaluation of compound activities facilitate interassay comparisons of potencies and, thus, concerted drug discovery approaches. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Towards an understanding of the influence of national culture on organisational viability: An exploratory study

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    Awuzie Bankole O.

    2017-06-01

    Full Text Available ABSTRACT Viability connotes a system’s ability to become ultra-stable through effective self-regulation of its internal processes and information processing among its subsystems. Applying this to an infrastructure delivery system (IDS context, this study proposes that an IDS can successfully deliver on client requirements only if they attain and maintain viability. Research into the influence of National Culture (NC on an IDS’s viability appears to be lacking; hence this study. Adopting a multi-case study, qualitative research design, this study explores three IDSs involved in the delivery of infrastructure projects in two different NC contexts; Nigeria and the United Kingdom. 25 semi-structured interviews were conducted across the cases to provide for an in-depth understanding of existing interactions between participants in these delivery systems: client/project sponsor; main contractor and sub-contractors and to understand the influence of the prevailing national culture on such interactions, if any. Findings indicate that NC in project delivery environments influence the ability of IDSs to attain viability, especially as it pertains to the sustenance of Team Quality Attributes (TWQ within the system. Based on these findings, it is expected that in modelling IDSs for viability, adequate consideration should be given to the prevailing NC by project managers and planners.

  10. Postoperative Hypoparathyroidism and the Viability of the Parathyroid Glands During Thyroidectomy.

    Science.gov (United States)

    Ji, Yong Bae; Song, Chang Myeon; Sung, Eui Suk; Jeong, Jin Hyeok; Lee, Chang Beom; Tae, Kyung

    2017-09-01

    To prevent hypoparathyroidism after thyroidectomy, preservation of the parathyroid glands and their vascularity are essential. The aim of this study was to determine the association between postoperative parathyroid function and the viability of the parathyroid glands during thyroidectomy. We prospectively analyzed 111 patients who underwent total thyroidectomy and in whom all 4 parathyroid glands were preserved in situ during the operation. The surgeons scored the viability of each parathyroid gland from 0 (normal) to 3 (severely compromised viability) based on its gross appearance and vascularity intraoperatively. The index of parathyroid viability score (IPVS) was defined as the sum of the viability scores of the 4 parathyroid glands. We evaluated the relationship between postoperative parathyroid function and IPVS. Transient hypoparathyroidism occurred in 25 patients (22.5%), and permanent hypoparathyroidism in 4 patients (3.6%). The IPVS were significantly different in the three groups: 2.87±1.46 in the normal group, 3.68±1.41 in the transient hypoparathyroidism group and 7.50±1.00 in the permanent hypoparathyroidism group. The rates of transient hypoparathyroidism were 13.6% in patients with IPVS 0-2, 23.8% in patients with IPVS 3-4, and 42.9% in patients with IPVS 5-6. All the patients with IPVS of 7 or more had permanent hypoparathyroidism. IPVS is correlated with the incidence of hypoparathyroidism. It could be a good quantitative indicator of the probability of hypoparathyroidism after thyroidectomy.

  11. FT-IR Characterization of Pollen Biochemistry, Viability, and Germination Capacity in Saintpaulia H. Wendl. Genotypes

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    Erzsebet Buta

    2015-01-01

    Full Text Available FT-IR characterization of pollen biochemistry was analyzed to detect possible connection with the viability (by staining with potassium iodide, 25% and the germination capacity (on solid nutrient medium, in 15 Saintpaulia genotypes. Vibrational spectroscopy indicates that the pollen of S. ionantha genotype “Red Velvet” is rich in proteins, lipids, triglycerides, and esters and has a viability of 88.4% and a low germination capacity (27.16%. For S. ionantha “Jolly Red” and “Lucky Ladybug” genotypes, pollen showed high viability (88.81–91.49% and low germination capacity (23.02–9.17%, even though the pollen is rich in carbohydrates. S. ionantha “Aloha Orchid” genotype has the highest percentage of viability (94.32% and germination capacity (45.73% and a rich content of carbohydrates and polygalacturonic acids. In S. rupicola and S. ionantha genotypes, the rich content of polygalacturonic acids, lipids, and carbohydrates favourably influenced the germination capacity. Spectroscopic result indicates, through different absorbance band intensity, a possible link between biochemical composition, viability, and germination capacity of Saintpaulia pollen. To determine exactly the relation between biochemistry and biological processes, it is necessary to initiate quantitative researches.

  12. LONGEVITY AND VIABILITY OF Taenia solium EGGS IN THE DIGESTIVE SYSTEM OF THE BEETLE Ammophorus rubripes

    Science.gov (United States)

    Gomez-Puerta, Luis Antonio; Lopez-Urbina, Maria Teresa; Garcia, Hector Hugo; Gonzalez, Armando Emiliano

    2015-01-01

    The present study evaluated the capacity of Ammophorus rubripes beetles to carry Taenia solium eggs, in terms of duration and viability of eggs in their digestive system. One hundred beetles were distributed into five polyethylene boxes, and then they were infected with T. solium eggs. Gravid proglottids of T. solium were crushed and then mixed with cattle feces. One gram of this mixture was placed in each box for 24 hours, after which each group of beetles was transferred into a new clean box. Then, five beetles were dissected every three days. Time was strongly associated with viability (r=0.89; Psystem of each beetle were counted and tested for viability. Taenia solium eggs were present in the beetle’s digestive system for up to 39 days (13th sampling day out of 20), gradually reducing in numbers and viability, which was 0 on day 36 post-infection. Egg viability was around 40% up to day 24 post-infection, with a median number of eggs of 11 per beetle at this time. Dung beetles may potentially contribute towards dispersing T. solium eggs in endemic areas. PMID:24728368

  13. Mechanism of H₂O₂-induced oxidative stress regulating viability and biocontrol ability of Rhodotorula glutinis.

    Science.gov (United States)

    Chen, Jian; Li, Boqiang; Qin, Guozheng; Tian, Shiping

    2015-01-16

    The use of antagonistic yeasts to control postharvest pathogens is a promising alternative to fungicides. The effectiveness of the antagonists against fungal pathogens is greatly dependent on their viability, which is usually mediated by reactive oxygen species (ROS). Here, we investigated the effects of H₂O₂-induced oxidative stress on the viability and biocontrol efficacy of Rhodotorula glutinis and, using flow cytometric analysis, observed the changes of ROS accumulation and apoptosis in the yeast cells with or without H₂O₂ treatment. We found that the viability of R. glutinis decreased in a time- and dose-dependent manner under H₂O₂-induced oxidative stress. Compared to the control, yeast cells exposed to oxidative stress exhibited more accumulation of ROS and higher levels of protein oxidative damage, but showed lower efficacy for biocontrol of Penicillium expansum causing blue mold rot on peach fruit. The results indicate that apoptosis is a main cause of the cell viability loss in R. glutinis, which is attributed to ROS accumulation under oxidative stress. These findings offer a plausible explanation that oxidative stress affects biocontrol efficacy of R. glutinis via regulating its viability and cell apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Effect of electrical charges and fields on injury and viability of airborne bacteria.

    Science.gov (United States)

    Mainelis, Gediminas; Górny, Rafał L; Reponen, Tiina; Trunov, Mikhaylo; Grinshpun, Sergey A; Baron, Paul; Yadav, Jagjit; Willeke, Klaus

    2002-07-20

    In this study, the effects of the electric charges and fields on the viability of airborne microorganisms were investigated. The electric charges of different magnitude and polarity were imparted on airborne microbial cells by a means of induction charging. The airborne microorganisms carrying different electric charge levels were then extracted by an electric mobility analyzer and collected using a microbial sampler. It was found that the viability of Pseudomonas fluorescens bacteria, used as a model for sensitive bacteria, carrying a net charge from 4100 negative to 30 positive elementary charges ranged between 40% and 60%; the viability of the cells carrying >2700 positive charges was below 1.5%. In contrast, the viability of the stress-resistant spores of Bacillus subtilis var. niger (used as simulant of anthrax-causing Bacillus anthracis spores when testing bioaerosol sensors in various studies), was not affected by the amount of electric charges on the spores. Because bacterial cells depend on their membrane potential for basic metabolic activities, drastic changes occurring in the membrane potential during aerosolization and the local electric fields induced by the imposed charges appeared to affect the sensitive cells' viability. These findings facilitate applications of electric charging for environmental control purposes involving sterilization of bacterial cells by imposing high electric charges on them. The findings from this study can also be used in the development of new bioaerosol sampling methods based on electrostatic principles. Copyright 2002 Wiley Periodicals, Inc.

  15. Effect of storage temperature on the viability of human periodontal ligament fibroblasts.

    Science.gov (United States)

    Chen, Fubo; Qi, Shengcai; Lu, Liyan; Xu, Yuanzhi

    2015-02-01

    The viability of periodontal ligament fibroblasts (PDLF) can affect the long-term prognosis of replanted avulsed teeth. When immediate replantation of an avulsed tooth is not possible, the cells should be incubated in a physiological storage medium instantly to maintain their biological activity. The ability of different storage media to preserve PDLF viability has been previously evaluated. However, few studies have showed the effect of temperature on the viability of PDLF cultured with various storage media in vitro. This study was designed to measure PDLF activity by CCK-8 assay to compare the effectiveness at 4, 22 (room temperature), and 37°C under various storage media. Statistical analysis demonstrated that tap water, saline, and saliva decreased cell viability as the storage temperature increased. But the temperature played only a minor role on cell viability when cells were incubated in Hank's balanced salt solution (HBSS), Dubelco's modified Eagle's medium (DMEM), or milk. Within the parameters of this study, it seems that room temperature is adequate for storing the avulsed teeth in HBSS, DMEM, or milk in the extra-alveolar period. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. In vitro pollen germination and pollen viability in passion fruit (Passiflora spp.

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares

    2013-12-01

    Full Text Available The use of Passiflora species for ornamental purposes has been recently developed, but little is known about pollen viability and the potential for crossing different species. The objective of this study was to evaluate the pollen viability of six Passiflora species collected from different physiological stages of development through in vitro germination and histochemical analysis using dyes. The pollen was collected in three stages (pre-anthesis, anthesis and post-anthesis. Three compositions of culture medium were used to evaluate the in vitro germination, and two dyes (2,3,5-triphenyltetrazolium chloride, or TTC, and Lugol's solution were used for the histochemical analysis. The culture medium containing 0.03% Ca(NO3 4H2O, 0.02% of Mg(SO4 .7H2O, 0.01% of KNO3, 0,01% of H3BO3, 15% sucrose, and 0.8% agar, pH 7.0, showed a higher percentage of pollen grains germinated. Anthesis is the best time to collect pollen because it promotes high viability and germination. The Lugol's solution and TTC dye overestimated the viability of pollen, as all accessions showed high viability indices when compared with the results obtained in vitro.

  17. Pollen viability and its effect on fruit set of oil palm (Elaeis guineensis Jacq.

    Directory of Open Access Journals (Sweden)

    ALFIN WIDIASTUTI

    2008-01-01

    Full Text Available The research was aimed at studying (1 the decline of pollen viability during storage, and (2 the effect of pollen amount on fruit set of oil palm (Elaeis guineensis Jacq.. The experiment was conducted at PT. Dami Mas Sejahtera and PT. Sinar Mas Agro Resource and Technology (SMART Tbk, Riau from February to August 2004. The first experiment was investigated up to six months storage period in the refrigerator, whereas in the second experiment a randomized complete block design with two factors was used: length of storage, i.e. 0, 1 and 2 months and amount of pollen, i.e. 0.022, 0.044, 0.066, 0.088, and 0.11 g mixed with powder to 10g to pollinate an inflorescence. The result showed that the viability of pollen started to decline three months after storage from about 92% to 83%, and declined to about 75% after six months of storage. Result of the second experiment showed that storage of pollen up to two months did not affect percentage of normal fruit, although the percentage of parthenocarpic fruits was decreased. This could be due to the high viability of pollen as the viability was remained high (about 90% after being stored for two months in the refrigerator. Pollen with high viability could be used in a smaller amount to pollinate a female inflorescence without affecting fruit set of about 70-76%.SD037 had a higher reproductive success than SD038 and SD39.

  18. Institutional Viability Of The Cooperative In Northern Samar And The Variates Affecting It

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    Farah Alo Mdulid

    2015-08-01

    Full Text Available Abstract This study attempted to find out the institutional viability of cooperatives in Northern Samar in terms of profitability liquidity and the variates affecting its viability. Thirty-three 33 registered primary cooperatives were the respondents. It adopted descriptive-evaluative research with multiple regression analysis in testing the relationship of the variables. Findings showed that 15 or 45 percent of the primary cooperatives were viable while 18 or 55 percent were not viable in terms of profitability. In terms of liquidity 28 or 85 percent were viable while 5 or 15 percent were non-viable. Results also revealed that the number of years of operation the number of employees and staff the rate of loan repayments and the amount of current authorized share capital significantly affected the viability of Cooperatives. Generally Cooperatives in Northern Samar are less profitable however majority of them are liquid which implies that the services are continuously rendered to the members. Specifically the finding suggests that the absence of participatory and collaborative management efforts of the members and the officials adversely affect the organizational financial viability. Key Words Institutional liquidity profitability. primary cooperativeratiovariates viability

  19. On the evolution of genetic incompatibility systems. V. Origin of sporophytic self-incompatibility in response to overdominance in viability.

    Science.gov (United States)

    Uyenoyama, M K

    1989-12-01

    Conditions for the origin of partial sporophytic self-incompatibility (SSI) are obtained from two quantitative models, which differ with respect to the determination of offspring viability. Offspring viability depends solely on the source (self or nonself) of the fertilizing pollen in the first model, which describes changes only at a primitive S-locus itself. Two loci evolve in the second model: overdominant viability selection maintains an arbitrary number of alleles at one locus, with SSI under the control of a separate locus. In both cases, the origin of SSI requires that the relative change in the numbers of offspring derived by the two reproductive modes compensate for the twofold cost of outcrossing. In the first model studied, the viability of inbred offspring fully determines the relative change in the numbers of inbred and outbred offspring produced. In the second model, the relative change in offspring numbers depends in addition on associations between the S-locus and the viability locus. Because these two-locus associations are comparable in magnitude to the differences between the viabilities of inbred and outbred offspring, SSI can arise under less restrictive conditions than expected from the one-locus model. Greater allelic multiplicity at the viability locus facilitates the origin of SSI by reducing the relative viability of inbred offspring. Tight linkage between the S-locus and the viability locus and high rates of receipt of self-pollen promote the generation and maintenance of associations between the S-locus and the viability locus. In populations in which more than two viability alleles are maintained, the active S-allele can invade even in the absence of linkage with the viability locus. The present study establishes that incompatibility systems can arise in response to identity disequilibrium between a modifier of incompatibility and a locus subject to overdominant viability selection; in particular, compensation for the twofold cost of

  20. Efficacy of propidium iodide and FUN-1 stains for assessing viability in basidiospores of Rhizopogon roseolus.

    Science.gov (United States)

    Fernández-Miranda, Elena; Majada, Juan; Casares, Abelardo

    2017-01-01

    The use of spores in applications of ectomycorrhizal fungi requires information regarding spore viability and germination, especially in genera such as Rhizopogon with high rates of spore dormancy. The authors developed a protocol to assess spore viability of Rhizopogon roseolus using four vital stains to quantify spore viability and germination and to optimize storage procedures. They showed that propidium iodide is an excellent stain for quantifying nonviable spores. Observing red fluorescent intravacuolar structures following staining with 2-chloro-4-(2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene)-1-phenylquinolinium iodide (FUN-1) can help identify viable spores that are activated. At 6 mo and 1 y, the spores kept in a water suspension survived better than those left within intact, dry gasterocarps. Our work highlights the importance of temperature, nutrients, and vitamins for maturation and germination of spores of R. roseolus during 1 y of storage.

  1. Cell adhesion and viability of human endothelial cells on electrospun polymer scaffolds

    Directory of Open Access Journals (Sweden)

    Matschegewski Claudia

    2016-09-01

    Full Text Available The usage of electrospun polymer scaffolds is a promising approach for artificial heart valve design. This study aims at the evaluation of biological performance of nanofibrous polymer scaffolds poly(L-lactide PLLA L210, PLLA L214 and polyamide-6 fabricated by electrospinning via analyzing viability, adhesion and morphology of human umbilical vein endothelial cells (EA.hy926. Nanofibrous surface topography was shown to influence cell phenotype and cell viability according to the observation of diminished cell spreading accompanied with reduced cell viability on nonwovens. Among those, highest biocompatibility was assessed for PLLA L214, although being generally low when compared to the planar control surface. Electrospinning was demonstrated as an innovative technique for the fabrication of advanced biomaterials aiming at guided cellular behavior as well as the design of novel implant platforms. A better understanding of cell–biomaterial interactions is desired to further improve implant development.

  2. Influence of electrospun scaffolds prepared from distinct polymers on proliferation and viability of endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Matveeva, V. G., E-mail: matveeva-vg@mail.ru; Antonova, L. V., E-mail: antonova.la@mail.ru; Velikanova, E. A.; Sergeeva, E. A.; Krivkina, E. O.; Glushkova, T. V.; Kudryavtseva, Yu. A.; Barbarash, O. L.; Barbarash, L. S. [Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, 650002 (Russian Federation)

    2015-10-27

    We compared electrospun nonwoven scaffolds from polylactic acid (PLA), polycaprolactone (PCL), and polyhydroxybutyrate/valerate (PHBV)/polycaprolactone (PHBV/PCL). The surface of PHBV/PCL and PCL scaffolds was highly porous and consisted of randomly distributed fibers, whilst the surface of PLA scaffolds consisted of thin straight fibers, which located more sparsely, forming large pores. Culture of EA.hy 926 endothelial cells on these scaffolds during 7 days and further fluorescent microscopy demonstrated that the surface of PHBV/PCL scaffolds was most favorable for efficient adhesion, proliferation, and viability of endothelial cells. The lowest proliferation rate and cell viability were detected on PLA scaffolds. Therefore, PHBV/PCL electrospun nonwoven scaffolds demonstrated the best results regarding endothelial cell proliferation and viability as compared to PCL and PLA scaffolds.

  3. Respirator Testing Using Virus Aerosol: Comparison between Viability Penetration and Physical Penetration.

    Science.gov (United States)

    Zuo, Zhili; Kuehn, Thomas H; Pui, David Y H

    2015-07-01

    Viability, fluorescence (particle volume), photometric, viral RNA, and particle number penetration of MS2 bacteriophage through filter media used in three different models of respirators were compared to better understand the correlation between viability and physical penetration. Although viability and viral RNA penetration were better represented by particle volume penetration than particle number penetration, they were several-fold lower than photometric penetration, which was partially due to the difference in virus survival between upstream and downstream aerosol samples. Results suggest that the current NIOSH photometer-based test method can be used as a quick means to roughly differentiate respirators with different performance against virus aerosols. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  4. Improved β Decay Branching Ratios

    Science.gov (United States)

    Iacob, V. E.; Hardy, J. C.; Golovko, V.

    2008-04-01

    The work we report here aims at increasing the precision possible in the measurement of branching ratios for superallowed β^+decays. Such highly accurate values are essential in generating precise ft-values for 0^+->0^+decays, which can then be used to test the Standard Model via the unitarity of the Cabibbo-Kobayashi-Maskawa matrix [1]. The required precision is ˜0.1% or better. While this limit was already achieved in the case of ^34Ar [2], it would have been very difficult, if not impossible, to achieve it for other β^+-decays without an upgrade to our acquisition and data-reduction systems. We have thus improved the controls over all the key elements in our experimental set-up: we now have direct control over the dead-time for the singles and coincidence channels and <0.1 mm control over the source-detector distance. In addition, we have extensively studied the efficiency of the β-detector with source-measurements tested against various Monte Carlo programs [3]. We have tested our new acquisition set-up on ^60Co and ^22Na (β^- and β^+ emitters respectively) to validate our new methods. Preliminary results on the two sources are statistically consistent with the expected values. An ^34Ar decay experiment using the new experimental configuration has already been performed and is currently analyzed. [1] J.C. Hardy and I.S. Towner, PRC 71, 055501 (2005) [2] V. Iacob et al., BAPS 52(3)B16; BAPS 52(9)HF3 [3] V. Golovko et al., BAPS 52(9)DH4; this BAPS

  5. Direct analysis of bacterial viability in endotracheal tube biofilm from a pig model of methicillin-resistant Staphylococcus aureus pneumonia following antimicrobial therapy.

    Science.gov (United States)

    Fernández-Barat, Laia; Li Bassi, Gianluigi; Ferrer, Miquel; Bosch, Anna; Calvo, Maria; Vila, Jordi; Gabarrús, Albert; Martínez-Olondris, Pilar; Rigol, Montse; Esperatti, Mariano; Luque, Néstor; Torres, Antoni

    2012-07-01

    Confocal laser scanning microscopy (CLSM) helps to observe the biofilms formed in the endotracheal tube (ETT) of ventilated subjects and to determine its structure and bacterial viability using specific dyes. We compared the effect of three different treatments (placebo, linezolid, and vancomycin) on the bacterial biofilm viability captured by CLSM. Eight pigs with pneumonia induced by methicillin-resistant Staphylococcus aureus (MRSA) were ventilated up to 96 h and treated with linezolid, vancomycin, or placebo (controls). ETT images were microscopically examined after staining with the live/dead(®) BacLight(™) Kit (Invitrogen, Barcelona, Spain) with a confocal laser scanning microscope. We analyzed 127 images obtained by CLSM. The median ratio of live/dead bacteria was 0.51, 0.74, and 1 for the linezolid, vancomycin, and control groups, respectively (P = 0.002 for the three groups); this ratio was significantly lower for the linezolid group, compared with the control group (P = 0.001). Images showed bacterial biofilm attached and non-attached to the ETT surface but growing within secretions accumulated inside ETT. Systemic treatment with linezolid is associated with a higher proportion of dead bacteria in the ETT biofilm of animals with MRSA pneumonia. Biofilm clusters not necessarily attach to the ETT surface. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  6. Assessment of myocardial viability using 123I-labeled iodophenylpentadecanoic acid at sustained low flow or after acute infarction and reperfusion.

    Science.gov (United States)

    Yang, J Y; Ruiz, M; Calnon, D A; Watson, D D; Beller, G A; Glover, D K

    1999-05-01

    123I-labeled iodophenylpentadecanoic acid (IPPA) is a synthetic fatty acid that may be useful for determination of myocardial viability. We investigated the uptake and clearance kinetics of this tracer in canine models of ischemia and infarction. In protocol 1, 185 MBq (5 mCi) 123I-IPPA were injected intravenously in 19 dogs with 50% left anterior descending artery (LAD) flow reduction. In 9 dogs, 201TI was coinjected. In protocol 2, 5 dogs underwent LAD occlusion for 3 h, and 123I-IPPA was injected 60 min after reperfusion. All dogs had flow measured by microspheres, regional systolic thickening by ultrasonic crystals and measurements of postmortem risk area and infarct size. Tracer activities were quantified by gamma well counting and by serial imaging. In protocol 1 dogs with sustained low flow (50% +/- 4%) and absence of systolic thickening (-3.2% +/- 1%), 123I-IPPA defect magnitude (LAD/left circumflex artery [LCX] count ratios) decreased from 0.65 +/- 0.02 to 0.74 +/- 0.02 at 30 min and to 0.84 +/- 0.03 at 2 h (P IPPA LAD/LCX activity ratio (0.99 +/- 0.05) was significantly greater than the flow ratio (0.53 +/- 0.04) at injection, confirming complete rest redistribution. The final 123I-IPPA activity ratio was significantly greater than the 201TI ratio over the 2-h period (P IPPA, because uptake averaged 64% of normal in the central necrotic region, where flow averaged IPPA imaging may be useful for assessing myocardial viability under conditions of sustained low flow and myocardial asynergy, such as appears to exist in patients with chronic coronary artery disease and depressed left ventricular function. In contrast, 123I-IPPA given early after reperfusion following prolonged coronary occlusion overestimates the degree of viability and therefore may not provide useful information pertaining to the degree of myocardial salvage after reflow in the setting of acute myocardial infarction.

  7. Is cell viability always directly related to corrosion resistance of stainless steels?

    Energy Technology Data Exchange (ETDEWEB)

    Salahinejad, E., E-mail: salahinejad@kntu.ac.ir [Faculty of Materials Science and Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Ghaffari, M. [Bruker AXS Inc., 5465 East Cheryl Parkway, Madison, WI 53711 (United States); Vashaee, D. [Electrical and Computer Engineering Department, North Carolina State University, Raleigh, NC 27606 (United States); Tayebi, L. [Department of Developmental Sciences, Marquette University School of Dentistry, Milwaukee, WI 53201 (United States); Department of Engineering Science, University of Oxford, Oxford OX1 3PJ (United Kingdom)

    2016-05-01

    It has been frequently reported that cell viability on stainless steels is improved by increasing their corrosion resistance. The question that arises is whether human cell viability is always directly related to corrosion resistance in these biostable alloys. In this work, the microstructure and in vitro corrosion behavior of a new class of medical-grade stainless steels were correlated with adult human mesenchymal stem cell viability. The samples were produced by a powder metallurgy route, consisting of mechanical alloying and liquid-phase sintering with a sintering aid of a eutectic Mn–Si alloy at 1050 °C for 30 and 60 min, leading to nanostructures. In accordance with transmission electron microscopic studies, the additive particles for the sintering time of 30 min were not completely melted. Electrochemical impedance spectroscopic experiments suggested the higher corrosion resistance for the sample sintered for 60 min; however, a better cell viability on the surface of the less corrosion-resistant sample was unexpectedly found. This behavior is explained by considering the higher ion release rate of the Mn–Si additive material, as preferred sites to corrosion attack based on scanning electron microscopic observations, which is advantageous to the cells in vitro. In conclusion, cell viability is not always directly related to corrosion resistance in stainless steels. Typically, the introduction of biodegradable and biocompatible phases to biostable alloys, which are conventionally anticipated to be corrosion-resistant, can be advantageous to human cell responses similar to biodegradable metals. - Highlights: • Cell viability vs. corrosion resistance for medical-grade stainless steels • The stainless steel samples were prepared by powder metallurgy. • Unpenetrated additive played a critical role in the correlation.

  8. Optimizing Photo-Encapsulation Viability of Heart Valve Cell Types in 3D Printable Composite Hydrogels.

    Science.gov (United States)

    Kang, Laura Hockaday; Armstrong, Patrick A; Lee, Lauren Julia; Duan, Bin; Kang, Kevin Heeyong; Butcher, Jonathan Talbot

    2017-02-01

    Photocrosslinking hydrogel technologies are attractive for the biofabrication of cardiovascular soft tissues, but 3D printing success is dependent on multiple variables. In this study we systematically test variables associated with photocrosslinking hydrogels (photoinitiator type, photoinitiator concentration, and light intensity) for their effects on encapsulated cells in an extrusion 3D printable mixture of methacrylated gelatin/poly-ethylene glycol diacrylate/alginate (MEGEL/PEGDA3350/alginate). The fabrication conditions that produced desired hydrogel mechanical properties were compared against those that optimize aortic valve or mesenchymal stem cell viability. In the 3D hydrogel culture environment and fabrication setting studied, Irgacure can increase hydrogel stiffness with a lower proportional decrease in encapsulated cell viability compared to VA086. Human adipose derived mesenchymal stem cells (HADMSC) survived increasing photoinitiator concentrations in photo-encapsulation conditions better than aortic valve interstitial cells (HAVIC) and aortic valve sinus smooth muscle cells (HASSMC). Within the range of photo-encapsulation fabrication conditions tested with MEGEL/PEGDA/alginate (0.25-1.0% w/v VA086, 0.025-0.1% w/v Irgacure 2959, and 365 nm light intensity 2-136 mW/cm2), the highest viabilities achieved were 95, 93, and 93% live for HASSMC, HAVIC, and HADMSC respectively. These results identify parameter combinations that optimize cell viability during 3D printing for multiple cell types. These results also indicate that general oxidative stress is higher in photocrosslinking conditions that induce lower cell viability. However, suppressing this increase in intracellular oxidative stress did not improve cell viability, which suggests that other stress mechanisms also contribute.

  9. Assessment of cryopreserved donor skin viability: the experience of the regional tissue bank of Siena.

    Science.gov (United States)

    Pianigiani, E; Tognetti, L; Ierardi, F; Mariotti, G; Rubegni, P; Cevenini, G; Perotti, R; Fimiani, M

    2016-06-01

    Skin allografts from cadaver donors are an important resource for treating extensive burns, slow-healing wounds and chronic ulcers. A high level of cell viability of cryopreserved allografts is often required, especially in burn surgery, in Italy. Thus, we aimed to determine which conditions enable procurement of highly viable skin in our Regional Skin Bank of Siena. For this purpose, we assessed cell viability of cryopreserved skin allografts procured between 2011 and 2013 from 127 consecutive skin donors, before and after freezing (at day 15, 180, and 365). For each skin donor, we collected data concerning clinical history (age, sex, smoking, phototype, dyslipidemia, diabetes, cause of death), donation process (multi-tissue or multi-organ) and timing of skin procurement (assessment of intervals such as death-harvesting, harvesting-banking, death-banking). All these variables were analysed in the whole case study (127 donors) and in different groups (e.g. multi-organ donors, non refrigerated multi-tissue donors, refrigerated multi-tissue donors) for correlations with cell viability. Our results indicated that cryopreserved skin allografts with higher cell viability were obtained from female, non smoker, heartbeating donors died of cerebral haemorrhage, and were harvested within 2 h of aortic clamping and banked within 12 h of harvesting (13-14 h from clamping). Age, cause of death and dyslipidaemia or diabetes did not appear to influence cell viability. To maintain acceptable cell viability, our skin bank needs to reduce the time interval between harvesting and banking, especially for refrigerated donors.

  10. Transgenerational effects of maternal and grandmaternal age on offspring viability and performance in Drosophila melanogaster.

    Science.gov (United States)

    Bloch Qazi, Margaret C; Miller, Paige B; Poeschel, Penny M; Phan, Mai H; Thayer, Joseph L; Medrano, Christian L

    2017-07-01

    In non-social insects, fitness is determined by relative lifetime fertility. Fertility generally declines with age as a part of senescence. For females, senescence has profound effects on fitness by decreasing viability and fertility as well as those of her offspring. However, important aspects of these maternal effects, including the cause(s) of reduced offspring performance and carry-over effects of maternal age, are poorly understood. Drosophila melanogaster is a useful system for examining potential transgenerational effects of increasing maternal age, because of their use as a model system for studying the physiology and genetic architecture of both reproduction and senescence. To test the hypothesis that female senescence has transgenerational effects on offspring viability and development, we measured the effects of maternal age on offspring survival over two generations and under two larval densities in two laboratory strains of flies (Oregon-R and Canton-S). Transgenerational effects of maternal age influence embryonic viability and embryonic to adult viability in both strains. However, the generation causing the effects, and the magnitude and direction of those effects differed by genotype. The effects of maternal age on embryonic to adult viability when larvae are stressed was also genotype-specific. Maternal effects involve provisioning: older females produced smaller eggs and larger offspring. These results show that maternal age has profound, complex, and multigenerational consequences on several components of offspring fitness and traits. This study contributes to a body of work demonstrating that female age is an important condition affecting phenotypic variation and viability across multiple generations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Seed viability of five wild Saudi Arabian species by germination and X-ray tests

    Directory of Open Access Journals (Sweden)

    B.A. Al-Hammad

    2017-09-01

    Full Text Available Our objective was to evaluate the usefulness of the germination vs. the X-ray test in determining the initial viability of seeds of five wild species (Moringa peregrina, Abrus precatorius, Arthrocnemum macrostachyum, Acacia ehrenbergiana and Acacia tortilis from Saudi Arabia. Usually several days were required to determine the viability of all five species via germination tests. However, X-ray test will give immediate results on filled/viable seeds. Seeds of all species, except Acacia ehrenbergiana and Acacia tortilis showed high viability in both germination (96–72% at 25/15 °C, 94–70% at 35/25 °C and X-ray (100–80% test. Furthermore, there was a general agreement between the germination (19%, 14% at 25/15 °C and 17% and 12% at 35/25 °C and X-ray (8%, 4% tests in which seed viability of Acacia ehrenbergiana and Acacia tortilis was very low due to insect damaged embryo as shown in X-ray analysis. Seeds of Abruspreca torius have physical dormancy, which was broken by scarification in concentrated sulfuric acid (10 min, and they exhibited high viability in both the germination (83% at 25/15 °C and 81% at 35/25 °C and X-ray (96% tests. Most of the nongerminated seeds of the five species except those of Acacia ehrenbergiana and Acacia tortilis, were alive as judged by the tetrazolium test (TZ. Thus, for the five species examined, the X-ray test was proved to be a good and rapid predictor of seed viability.

  12. Quantifying spore viability of the honey bee pathogen Nosema apis using flow cytometry.

    Science.gov (United States)

    Peng, Yan; Lee-Pullen, Tracey F; Heel, Kathy; Millar, A Harvey; Baer, Boris

    2014-05-01

    Honey bees are hosts to more than 80 different parasites, some of them being highly virulent and responsible for substantial losses in managed honey bee populations. The study of honey bee pathogens and their interactions with the bees' immune system has therefore become a research area of major interest. Here we developed a fast, accurate and reliable method to quantify the viability of spores of the honey bee gut parasite Nosema apis. To verify this method, a dilution series with 0, 25, 50, 75, and 100% live N. apis was made and SYTO 16 and Propidium Iodide (n = 35) were used to distinguish dead from live spores. The viability of spores in each sample was determined by flow cytometry and compared with the current method based on fluorescence microscopy. Results show that N. apis viability counts using flow cytometry produced very similar results when compared with fluorescence microscopy. However, we found that fluorescence microscopy underestimates N. apis viability in samples with higher percentages of viable spores, the latter typically being what is found in biological samples. A series of experiments were conducted to confirm that flow cytometry allows the use of additional fluorescent dyes such as SYBR 14 and SYTOX Red (used in combination with SYTO 16 or Propidium Iodide) to distinguish dead from live spores. We also show that spore viability quantification with flow cytometry can be undertaken using substantially lower dye concentrations than fluorescence microscopy. In conclusion, our data show flow cytometry to be a fast, reliable method to quantify N. apis spore viabilities, which has a number of advantages compared with existing methods. © 2013 International Society for Advancement of Cytometry.

  13. The effect of glucocorticoids on tendon cell viability in human tendon explants

    Science.gov (United States)

    Lui, Wai Ting; Chuen Fu, Sai; Man Lee, Kwong

    2009-01-01

    Background and purpose Previous studies on the culture of human tenocytes have shown that dexamethasone and triamcino-lone reduce cell viability, suppress cell proliferation, and reduce collagen synthesis. However, such cell cultures lack the extracellular matrix and three-dimensional structure of normal tendons, which affects their response to stimuli. We established a human tendon explant culture system and tested the effects of dexamethasone and triamcinolone on cell viability. Methods Primary human tendon explant cultures were prepared from healthy hamstring tendons. Tendon strips were harvested from hamstring tendons and cultured in 24-well plates in Dulbecco’s modification of Eagle’s Medium (DMEM) supplemented with 2% fetal calf serum. The tendon explants were treated with 0 μM (control), 10 μM, or 100 μM dexamethasone sodium phosphate or 0 μM (control), 10 μM, or 100 μM triamcinolone acetonide in DMEM for 96 h. Cell viability was measured by Alamar blue assay before and after glucocorticoid treatment. Results Incubation with 10 μM and 100 μM dexamethasone reduced cell viability in human tendon explants by 35% and 45%, respectively, as compared to a 6% increase in the controls (p = 0.01, mixed-effects ANOVA). Triamcinolone at 10 μM and 100 μM reduced cell viability by 33% and 36%, respectively, as compared to a 9% increase in the controls (p = 0.07, mixed-effects ANOVA). Interpretation Human tendon explant cultures can be used to study the effects of glucocorticoids on human tendon. Dexamethasone and triamcinolone suppress the cell viability of human tendon in its natural 3-dimensional environment with matrix anchorage. Human tendon explant cultures provide a species-specific model for further investigation of the effects of glucocorticoids on the metabolism of the extracellular matrix of human tendon, and on its mechanical properties. PMID:19421908

  14. Evaluation of myocardial viability with contrast-enhanced magnetic resonance imaging - comparison of the late enhancement technique with positron emission tomography; Myokardiale Vitalitaetsdiagnostik mit kontrastverstaerkter Magnetresonanztomographie - Vergleich des ''late enhancement''-Konzepts mit der Positronen-Emissions-Tomographie

    Energy Technology Data Exchange (ETDEWEB)

    Hunold, P.; Vogt, F.M.; Barkhausen, J. [Inst. fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Essen (Germany); Brandt-Mainz, K.; Freudenberg, L. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Essen (Germany); Neumann, T. [Abt. fuer Kardiologie, Zentrum fuer Innere Medizin, Universitaetsklinikum Essen (Germany); Knipp, S. [Klinik fuer Thorax- und Kardiovaskulaere Chirurgie, Universitaetsklinikum Essen (Germany)

    2002-07-01

    Purpose: To compare contrast-enhanced magnetic resonance imaging (MRI) and positron emission tomography (PET) in the evaluation of myocardial viability. Methods: [{sup 18}F]-FDG-PET, [{sup 201}Tl]-TlCl-SPECT and contrast-enhanced MRI were performed in 29 patients with proven coronary artery disease and impaired left ventricular function to assess myocardial viability. MRI scans were done on a 1.5 T scanner (Magnetom Sonata, Siemens, Germany). After the steady-state free precession cine study, 0.2 mmol/kg BW of Gd-DPTA (Magnevist trademark, Schering, Germany) were administered i.v. For the detection of ''late enhancement'' (LE) indicating scar, left ventricular long axes and contiguous short axis slices of 8 mm thickness were scanned using an inversion recovery turbo gradient echo sequence (TR 8.0 ms; TE 4.0 ms; Tl 180 - 240 ms; FA 20 ). The evaluation of LE and FDG uptake in PET with perfusion defect in SPECT was done using an 8 (basal, mid) and 4 (apical) segment model in all short axes to cover the entire ventricle. The transmural extent of LE was assessed using a 4-point score system. Comparison between the two modalities was performed on a segmental basis. Results: A total of 1753 segments were assessed. In MRI, 40% of the segments showed myocardial scar, whereas PET revealed impaired uptake in 25%. MRI obtained a very low interobserver variability in detecting myocardial scar (kappa 0.92). Using PET as the standard of reference in the segmental comparison, contrast-enhanced MRI yielded a sensitivity of 84% and a specificity of 76% for the detection of scar. 18% of all segments showed LE but normal FDG uptake, 83% of them referred to subendocardial scars. Conclusions: There is close agreement between contrast-enhanced MRI and PET in detecting transmural moycardial scars. Superior spatial resolution enables MRI to detect and quantify even subendocardial scar. Therefore, larger studies using functional recovery after revascularisation as an

  15. Diagnosis of the Viability of Industrial Companies with Treasury Sensitivity Coefficient

    Directory of Open Access Journals (Sweden)

    Bogdan Andronic

    2014-05-01

    Full Text Available Generally, the firm viability can be defined as the ability to ensure a profitable activity in terms of financial equilibrium. Therefore, estimation of viability can be achieved by determining specific profitability and equilibrium indicators to determine the extent to which the economic surplus released by the company's activity, manages, depending on the particularities of the economic and financial structures set up, to turn into cash. This happens because profitability alone is not sufficient to ensure the financial soundness of the company.

  16. In vitro electrochemical corrosion and cell viability studies on nickel-free stainless steel orthopedic implants.

    Science.gov (United States)

    Salahinejad, Erfan; Hadianfard, Mohammad Jafar; Macdonald, Digby Donald; Sharifi-Asl, Samin; Mozafari, Masoud; Walker, Kenneth J; Rad, Armin Tahmasbi; Madihally, Sundararajan V; Tayebi, Lobat

    2013-01-01

    The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments.

  17. Technical Viability of Battery Second Life: A Study from the Ageing Perspective

    DEFF Research Database (Denmark)

    Martinez-Laserna, Egoitz; Sarasketa-Zabala, Elixabet; Stroe, Daniel-Ioan

    2018-01-01

    Reusing electric vehicle batteries once they have been retired from the automotive application is stated as one of the possible solutions to reduce electric vehicle costs. Many publications in literature have analysed the economic viability of such a solution, and some car manufacturers have...... recently started running several projects to demonstrate the technical viability of the so-called battery second life. Nevertheless, the degradation behaviour of second life batteries remains unknown and represents one of the biggest gaps in the literature. The present work aims at evaluating the effects...

  18. In Vitro Electrochemical Corrosion and Cell Viability Studies on Nickel-Free Stainless Steel Orthopedic Implants

    Science.gov (United States)

    Salahinejad, Erfan; Hadianfard, Mohammad Jafar; Macdonald, Digby Donald; Sharifi-Asl, Samin; Mozafari, Masoud; Walker, Kenneth J.; Rad, Armin Tahmasbi; Madihally, Sundararajan V.; Tayebi, Lobat

    2013-01-01

    The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments. PMID:23630603

  19. Effect of Diluent and Relative Humidity on Apparent Viability of Airborne Pasteurella pestis

    Science.gov (United States)

    Won, William D.; Ross, Harold

    1966-01-01

    Airborne Pasteurella pestis (A-1122) at low humidities [20 to 50% relative humidity (RH)] exhibited exponential decay when either 1% peptone or Heart Infusion Broth (HIB) was used as the diluent in the viable assay system. At higher RH values (65 and 87%), however, the 1% peptone diluent adversely affected the viability assay. In contrast, HIB as diluent was remarkably effective in demonstrating a higher number of viable cells in aerosols held at high RH values. Similarly, with HIB as diluent, aerosols were shown to contain viable cells during 90 min of observation; with 1% peptone, viability was not detectable after 20 min in the airborne state. PMID:5970462

  20. Effect of diluent and relative humidity on apparent viability of airborne Pasteurella pestis.

    Science.gov (United States)

    Won, W D; Ross, H

    1966-09-01

    Airborne Pasteurella pestis (A-1122) at low humidities [20 to 50% relative humidity (RH)] exhibited exponential decay when either 1% peptone or Heart Infusion Broth (HIB) was used as the diluent in the viable assay system. At higher RH values (65 and 87%), however, the 1% peptone diluent adversely affected the viability assay. In contrast, HIB as diluent was remarkably effective in demonstrating a higher number of viable cells in aerosols held at high RH values. Similarly, with HIB as diluent, aerosols were shown to contain viable cells during 90 min of observation; with 1% peptone, viability was not detectable after 20 min in the airborne state.

  1. Adherence and viability of primary human keratinocytes and primary human dermal fibroblasts on acrylonitrile-based copolymers with different concentrations of positively charged functional groups.

    Science.gov (United States)

    Trescher, Karoline; Scharnagl, Nico; Kratz, Karl; Roch, Toralf; Lendlein, Andreas; Jung, Friedrich

    2012-01-01

    As shown in several studies, various properties of biomaterials such as stiffness, surface roughness, chemical composition or the amount of functional groups at the surface can influence adhesion, viability, proliferation and functionalities of cells. The aim of this work was to explore whether a cell-selective effect could be achieved for acrylonitrile-based copolymers containing different contents of positively charged functional groups, which were introduced by incorporation of methacrylic acid-2-aminoethylester hydrochloride (AEMA) units. The p(AN-co-AEMA) copolymers were synthesized by suspension polymerization in water and processed into disk shaped test specimen via a sintering process to ensure the absence of organic solvents in the copolymers. Copolymers with an AEMA content of 1.4, 1.6, and 4.4 mol-% were investigated according to their cell-selective capacity, which should support the adhesion, viability and proliferation of keratinocytes, while the adherence of fibroblasts should rather be disabled. The test samples were seeded with primary human keratinocytes and primary human dermal fibroblasts in mono- as well as in co-cultures. Tissue culture plate polystyrene (TCP) was used to control the physiologic growth of the cells. Density and viability of attached and non-adherent cells were analyzed by live/dead staining, lactate dehydrogenase (LDH) assay and flow cytometry with DAPI staining. For the assured discrimination of adherent cell types in coculture a keratin/vimentin-staining was performed. On copolymers with 4.4 mol-% AEMA adherent keratinocytes in monoculture and cocultured keratinocytes and fibroblasts showed a higher viability, a lower impairment of cell membranes and higher densities of viable cells compared to both other copolymers. For adherent fibroblasts these parameters did not differ between the copolymers and an increasing ratio of keratinocytes to fibroblasts in cocultures were found with increasing AEMA content. The results showed

  2. Effect of different calcium phosphate scaffold ratios on odontogenic differentiation of human dental pulp cells

    Energy Technology Data Exchange (ETDEWEB)

    AbdulQader, Sarah Talib [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Department of Pedodontic and Preventive Dentistry, College of Dentistry, University of Baghdad, Baghdad (Iraq); Kannan, Thirumulu Ponnuraj, E-mail: kannan@usm.my [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Rahman, Ismail Ab [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Ismail, Hanafi [School of Materials and Minerals Resource Engineering, Universiti Sains Malaysia, 14300 Penang (Malaysia); Mahmood, Zuliani [School of Dental Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2015-04-01

    Calcium phosphate (CaP) scaffolds have been widely and successfully used with osteoblast cells for bone tissue regeneration. However, it is necessary to investigate the effects of these scaffolds on odontoblast cells' proliferation and differentiation for dentin tissue regeneration. In this study, three different hydroxyapatite (HA) to beta tricalcium phosphate (β-TCP) ratios of biphasic calcium phosphate (BCP) scaffolds, BCP20, BCP50, and BCP80, with a mean pore size of 300 μm and 65% porosity were prepared from phosphoric acid (H{sub 2}PO{sub 4}) and calcium carbonate (CaCO{sub 3}) sintered at 1000 °C for 2 h. The extracts of these scaffolds were assessed with regard to cell viability and differentiation of odontoblasts. The high alkalinity, more calcium, and phosphate ions released that were exhibited by BCP20 decreased the viability of human dental pulp cells (HDPCs) as compared to BCP50 and BCP80. However, the cells cultured with BCP20 extract expressed high alkaline phosphatase activity and high expression level of bone sialoprotein (BSP), dental matrix protein-1 (DMP-1), and dentin sialophosphoprotein (DSPP) genes as compared to that cultured with BCP50 and BCP80 extracts. The results highlighted the effect of different scaffold ratios on the cell microenvironment and demonstrated that BCP20 scaffold can support HDPC differentiation for dentin tissue regeneration. - Highlights: • BCPs of different HA/β-TCP ratios influence cell microenvironment. • BCP20 decreases cell viability of HDPCs as compared to BCP50 and BCP80. • HDPCs cultured with BCP20 express highest ALP activity. • HDPCs cultured with BCP20 up-regulate BSP, DMP-1 and DSPP gene expressions. • BCP20 can support HDPC differentiation for dentin tissue regeneration.

  3. Application of different honey and dilution ratios on sperm quality of Pangasianodon hypopthalmus

    Directory of Open Access Journals (Sweden)

    Harton Arfah

    2015-10-01

    Full Text Available ABSTRACT The aim of this study was to determine the effect of various types of honey (longan honey, lychee honey, and cottonwoods honey on sperm quality of Siamese catfish Pangasianodon hypopthalmus with different dilution ratios after the storage period which includes sperm viability, fertilization rate, and hatching rate. The best treatment was obtained on the aplication of longan honey as a sperm diluent at 1:50 dilution ratio, with sperm viability 96.33±0.58%, fertilization rate 97.10±0.70%, and hatching rate 93.44±2.39%. Keywords: Siamese catfish, Pangasianodon hypophthalmus, honey, sperm dilution ratio  ABSTRAK Tujuan penelitian ini adalah mengevaluasi pengaruh pemberian berbagai jenis madu (madu kelengkeng, madu leci, dan madu randu terhadap kualitas sperma ikan patin siam Pangasianodon hypopthalmus dengan rasio pengenceran berbeda setelah masa penyimpanan, yang meliputi viabilitas sperma, tingkat fertilisasi, dan derajat penetasan. Hasil penelitian menunjukkan bahwa perlakuan terbaik didapatkan pada pemberian madu kelengkeng dengan rasio pengenceran 1:50 dengan viabilitas sperma 96,33±0,58%, tingkat fertilisasi 97,10±0,70%, dan derajat penetasan 93,44±2,39%. Kata kunci: ikan patin, Pangasianodon hypopthalmus, madu, rasio pengenceran sperma 

  4. Intra-procedural determination of viability by myocardial deformation imaging: a randomized prospective study in the cardiac catheter laboratory.

    Science.gov (United States)

    Schuh, Alexander; Karayusuf, Vadim; Altiok, Ertunc; Hamada, Sandra; Schröder, Jörg; Keszei, Andras; Kelm, Malte; de la Fuente, Matias; Frick, Michael; Radermacher, Klaus; Marx, Nikolaus; Becker, Michael

    2017-08-01

    The benefit of revascularization for functional recovery depends on the presence of viable myocardial tissue. Myocardial deformation imaging allows determination of myocardial viability. In a first approach, we assessed the optimal cutoff value to determine preserved viability by layer-specific echocardiographic myocardial deformation imaging at rest and low-dose dobutamine (DSE) echocardiography: regional endocardial circumferential strain (eCS) deformation imaging in the cardiac catheter laboratory (CLab), determination of myocardial viability by regional eCS deformation imaging in the CLab is feasible, safe, and cost effective and may become an emerging alternative to the current practice of two-stage viability diagnostics.

  5. Ciliary neurotrophic factor (CNTF) promotes skeletal muscle progenitor cell (MPC) viability via the phosphatidylinositol 3-kinase-Akt pathway.

    Science.gov (United States)

    Hiatt, Kelly; Lewis, Davina; Shew, Mathew; Bijangi-Vishehsaraei, Khadijeh; Halum, Stacey

    2014-12-01

    Muscle progenitor cells (MPCs) are currently being investigated as cellular vectors to deliver neurotrophic factor (NF) for the promotion of re-innervation after axonal injury. Ideally NF delivery in such a model would enhance axonal regeneration while simultaneously promoting MPC viability. To date, insulin-like growth factor 1 (IGF-1) is one of the few NFs known to promote both re-innervation and MPC viability. We herein identify ciliary neurotrophic factor (CNTF) as a factor that promotes MPC viability in culture, and demonstrate CNTF to impart greater viability effects on MPCs than IGF-1. We demonstrate that pharmacological inhibition via LY294002 results in abrogation of CNTF-mediated viability, suggesting that the CNTF-mediated MPC viability benefit occurs via the PI3-Akt pathway. Finally, we employ a genetic model, establishing MPC cultures from mice deficient in class IA PI-3 K (p85α(-/-) ) mice, and demonstrate that the viability benefit imparted by CNTF is completely abrogated in PI-3 K-deficient MPCs compared to wild-type controls. In summary, our investigations define CNTF as a promoter of MPC viability beyond IGF-1, and reveal that the CNTF-mediated MPC viability effects occur via the PI3-Akt pathway. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Retinoids, retinoid analogs, and lactoferrin interact and differentially affect cell viability of 2 bovine mammary cell types in vitro.

    Science.gov (United States)

    Wang, Y; Baumrucker, C R

    2010-07-01

    Two bovine mammary cell types (BME-UV1 and MeBo cells) were used to evaluate the effect of natural retinoids, retinoid analogs, and bovine lactoferrin (bLf) on cell viability in vitro. Experiments with Alamar Blue showed a linear relationship between fluorescence and cell viability index. The BME-UV1 cells exhibited twice the metabolic activity but required half the doubling time of the MeBo cells. The BME-UV1 cells were very sensitive to all-trans retinoic acid (atRA) inhibition of cell viability (Pretinoid-induced inhibition of cell viability, depending on the type of bovine mammary cell studied.

  7. The Mre11-Nbs1 Interface Is Essential for Viability and Tumor Suppression

    NARCIS (Netherlands)

    Kim, J.H. (Jun Hyun); M. Grosbart (Malgorzata); Anand, R. (Roopesh); C. Wyman (Claire); Cejka, P. (Petr); J.H.J. Petrini (John)

    2017-01-01

    textabstractThe Mre11 complex (Mre11, Rad50, and Nbs1) is integral to both DNA repair and ataxia telangiectasia mutated (ATM)-dependent DNA damage signaling. All three Mre11 complex components are essential for viability at the cellular and organismal levels. To delineate essential and non-essential

  8. Exercise regulates breast cancer cell viability: systemic training adaptations versus acute exercise responses.

    Science.gov (United States)

    Dethlefsen, Christine; Lillelund, Christian; Midtgaard, Julie; Andersen, Christina; Pedersen, Bente Klarlund; Christensen, Jesper Frank; Hojman, Pernille

    2016-10-01

    Exercise decreases breast cancer risk and disease recurrence, but the underlying mechanisms are unknown. Training adaptations in systemic factors have been suggested as mediating causes. We aimed to examine if systemic adaptations to training over time, or acute exercise responses, in breast cancer survivors could regulate breast cancer cell viability in vitro. Blood samples were collected from breast cancer survivors, partaking in either a 6-month training intervention or across a 2 h acute exercise session. Changes in training parameters and systemic factors were evaluated and pre/post exercise-conditioned sera from both studies were used to stimulate breast cancer cell lines (MCF-7, MDA-MB-231) in vitro. Six months of training increased VO2peak (16.4 %, p cancer cell viability in vitro. During 2 h of acute exercise, increases in serum lactate (6-fold, p exercise reduced viability by -9.2 % in MCF-7 (p = 0.04) and -9.4 % in MDA-MB-231 (p exercise session reduced breast cancer viability, while adaptations to 6 months of training had no impact. Our data question the prevailing dogma that training-dependent baseline reductions in risk factors mediate the protective effect of exercise on breast cancer. Instead, we propose that the cancer protection is driven by accumulative effects of repeated acute exercise responses.

  9. Commercial viability of medical devices using Headroom and return on investment calculation

    NARCIS (Netherlands)

    Markiewicz, Katarzyna; van Til, Janine Astrid; Steuten, Lotte Maria Gertruda; IJzerman, Maarten Joost

    2016-01-01

    The market success of a medical product depends on its commercial viability, yet this may be hard to predict during the development process of medical devices. This paper aims to determine if applying the Headroom method combined with return on investment (ROI) analysis allows for estimation of the

  10. Effect of the neurosphere size on the viability and metabolism of ...

    African Journals Online (AJOL)

    2012-02-23

    Feb 23, 2012 ... 1Dalian R&D Center for Stem Cell and Tissue Engineering, Dalian University of Technology, Dalian 116024, China. 2Department of ... diameter distribution of neurospheres, cell viability and metabolic activities were monitored, together with the ..... The application of NSPCs for the treatment of neuro-.

  11. Viability Assessment of a Repository at Yucca Mountain. Volume 1: Introduction and Site Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-01

    This first volume contains an introduction to the viability assessment, including the purpose, scope, waste forms, technical challenges, an historical perspective, regulatory framework, management of the repository, technical components, preparations for the license application, and repository milestones after the assessment. The second part of this first volume addresses characteristics of the Yucca Mountain site.

  12. Density, Viability Conidia And Symptoms of Metarhizium anisopliae infection on Oryctes rhinoceros larvae

    Science.gov (United States)

    Indriyanti, D. R.; Putri, R. I. P.; Widiyaningrum, P.; Herlina, L.

    2017-04-01

    M. anisopliae is parasitic fungus on insect pests; it is used as a biocontrol agent. M. anisopliae can be propagated on maize or rice substrate. M. anisopliae is currently sold in the form of kaolin powder formulations. Before it is used to check the density, viability and pathogenicity of M. anisopliae. However the problem is the kaolin powder very soft, so it difficult to distinguish between kaolin and conidia. This article gives information on how to calculate conidia density, viability and symptoms of M. anisopliae infection on Oryctes rhinoceros larvae. The study was conducted in the laboratory to determine the density and viability. The pathogenicity testing was done using pots. The Pot is containing soil substrate mixed with M. Anispoliae and ten tails O. Rhinoceros larvae per pot. The results showed that the density of M. anisopliae conidia was 1.81 x 108 conidia mL-1 and the viability was 94% within 24 hours. The larval mortality began to emerge in the 1st week, and all larvae died at the sixth week. The symptom of M. anisopliae infection on Oryctes rhinoceros larvae, there was a black spot on the larval integument. The larvae movements become slow and poor appetite; it will die within 3-7 days. The larvae die hard, and the white hyphae grow on the body surface that turns green.

  13. the viability of solar energy for domestic water heating in etidopian ...

    African Journals Online (AJOL)

    inexhaustible and freely available solar radiation. The conversion of solar energy in efficient :way to thermal energy incuts intial cost. If solar energy has to be used for this purpose, it has to bring economic benefit to the potential user by reducing the cost of water h~ting. The viability of solar water heating system to.

  14. Deviations from Hardy-Weinberg proportions for multiple alleles under viability selection.

    Science.gov (United States)

    Alvarez, Gonzalo

    2008-04-01

    Departures of genotype frequencies from Hardy-Weinberg proportions (HWP) for a single autosomal locus due to viability selection in a random mating population have been studied only for the two-allele case. In this article, the analysis of deviations from HWP due to constant viability selection is extended to multiple alleles. The deviations for an autosomal locus with k alleles are measured by means of k fii fixation indices for homozygotes and k(k-1)/2 fij fixation indices for heterozygotes, and expressions are obtained for these indices (FIS statistics) under the multiallele viability model. Furthermore, expressions for fii and fij when the multiallele polymorphism is at stable equilibrium are also derived and it is demonstrated that the pattern of multiallele Hardy-Weinberg deviations at equilibrium is characterized by a global heterozygote excess and a deficiency of each of the homozygotes. This pattern may be useful for detecting whether a given multiallelic polymorphism is at stable equilibrium in the population due to viability selection. An analysis of Hardy-Weinberg deviations from published data for the three-allele polymorphism at the beta-globin locus in human populations from West Africa is presented for illustration.

  15. Effect of the neurosphere size on the viability and metabolism of ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the metabolic activity and viability of the mouse neural stem/progenitor cells (NSPCs) affected by the size of neurospheres. NSPCs dissociated from the forebrain of embryonic 14 days (E14) mice were cultured in flask for 120 h. During cultivation, the diameter distribution of ...

  16. Pedagogical Technology of Improving the Students' Viability Levels in the Process of Mastering Foreign Language

    Science.gov (United States)

    Dmitrienko, Nadezhda; Ershova, Svetlana; Konovalenko, Tatiana; Kutsova, Elvira; Yurina, Elena

    2015-01-01

    The article points out that the process of mastering foreign language stimulates students' personal, professional and cultural growth, improving linguistic, communicative competences and viability levels. A proposed pedagogical technology of modeling different communicative situations has a serious synergetic potential for students' self organized…

  17. Evaluation of Commercial Off-the-Shelf Solutions for Supporting Viability Retention of Yersinia Pestis Cells

    Science.gov (United States)

    2017-11-01

    swabs Thermo Fisher Scientific, Inc. R723140 13 Skim milk (filtered) Cloverland Farms Dairy (Baltimore, MD) – 14 Spent tryptic soy broth (sTSB) Thermo...9 5. Fate of Y. pestis A1122 cells sampled from surfaces and stored in half-strength skim milk ...11 7. Effect of AZTD on sustained viability of sampled Y. pestis in skim milk

  18. Imaging techniques in nuclear cardiology for the assessment of myocardial viability

    NARCIS (Netherlands)

    Slart, RHJA; Bax, JJ; van Veldhuisen, DJ; van der Wall, EE; Dierckx, RAJO; Jager, PL

    The assessment of myocardial viability has become an important aspect of the diagnostic and prognostic work-up of patients with ischemic cardiomyopathy. Although revascularization may be considered in patients with sufficient viable myocardium, patients with predominantly scar tissue should be

  19. Soybean farm-saved seed viability and vigor as influenced by agro ...

    African Journals Online (AJOL)

    SARAH

    2016-05-31

    May 31, 2016 ... ABSTRACT. Objective: The experiment was conducted with the aim of assessing the soybean farm-saved seed viability and vigor as influenced by agro-ecological conditions of Meru South Sub-County, Kenya. Methodology and results: Within one month of harvest, soybean farm-saved-seed was randomly ...

  20. Structural and Economic Viability of 2D/3D Finite Element Analysis ...

    African Journals Online (AJOL)

    Consequently, this paper examines the structural and economic viability of arched conical roof truss system based on 2D/3D finite element method analysis. Analysis of the results showed that truss members were subjected to higher axial forces in 2D analysis than 3D analysis, which will result to overdesign of the structural ...

  1. Myocardial viability estimation during the recovery phase of stress echocardiography after acute beta-blocker administration.

    Science.gov (United States)

    Karagiannis, Stefanos E; Feringa, Harm H H; Bax, Jeroen J; Elhendy, Abdu; Dunkelgrun, Martin; Vidakovic, Radosav; Hoeks, S E; van Domburg, Ron; Valhema, Roelf; Cokkinos, Dennis V; Poldermans, Don

    2007-04-01

    Myocardial viability assessment in severely dysfunctional segments by dobutamine stress echocardiography (DSE) is less sensitive than nuclear scanning. To assess the additional value of using the recovery phase of DSE after acute beta-blocker administration for identifying viable myocardium. The study included 49 consecutive patients with ejection fraction (LVEF)DISA-SPECT) evaluation for viability of severely dysfunctional segments. Patients with >or=4 viable segments were considered viable. Coronary revascularization followed within 3 months in all patients. Radionuclide evaluation of LVEF was performed before and 12 months after revascularization. Viability with DISA-SPECT was detected in 463 (59%) segments, while 154 (19.7%) segments presented as scar. The number of viable segments increased from 415 (53%) at DSE to 463 (59%) at DSE and recovery, and the number of viable patients increased from 43 to 49 respectively. LVEF improved by >or=5% in 27 patients. Multivariate regression analysis showed that, DSE with recovery phase was the only independent predictor of >or=5% LVEF improvement after revascularization (OR 14.6, CI 1.4-133.7). In this study, we demonstrate that the recovery phase of DSE has an increased sensitivity for viability estimation compared to low-high dose DSE.

  2. Viability of Sea Fan Populations Impacted by Disease: Recruitment versus Incidence

    Directory of Open Access Journals (Sweden)

    Alberto M. Sabat

    2015-01-01

    Full Text Available Diseases are a threat to the viability of an increasing number of coral populations. In this study we analyze the effect of infection and recruitment rate on the viability and structure of sea fan (Gorgonia ventalina populations using a size-based matrix model parameterized with data from field studies. The model predicts that the viability of sea fan populations is strongly influenced by disease incidence and recruitment. Under high recruitment rate, the disease incidence threshold for population viability is 0.12/yr. However, populations with no or low incidence may also go locally extinct given persistent low recruitment. The model also predicts an effect of recruitment on disease prevalence. Everything else being equal, sites with low recruitment will exhibit higher disease prevalence than ones with high recruitment, particularly in medium and large colonies. Elasticity analysis reveals that changes in colony survivorship are likely to have the strongest effect on population growth rate, particularly given low recruitment. We conclude that under current levels of incidence sea fan populations in the Caribbean are not at risk. However, future epizootics are likely to produce local extinctions particularly if coinciding spatially or temporally with low recruitment.

  3. Understanding Financial Viability of Urban Consolidation Centres: Regent Street (London), Bristol/Bath & Nijmegen

    NARCIS (Netherlands)

    van Duin, Ron; van Dam, T; Wiegmans, B.; Tavasszy, L.A.

    2016-01-01

    The concept of an urban consolidation centre (UCC) has been extensively researched. Despite the potential positive environmental and social impact, the main obstacle remains the lack of a sustainable business model. The goal of this paper is to understand how to organize UCC viability as a concept

  4. Foam-Mat Freeze-Drying of Bifidobacterium longum RO175: Viability and Refrigerated Storage Stability.

    Science.gov (United States)

    Izquierdo-López, Danilo; Goulet, Jacques; Ratti, Cristina

    2017-01-01

    Foaming as a pretreatment was used prior to freeze-drying of Bifidobacterium longum RO175 to investigate the potential acceleration of the drying rate and increase in microorganism viability after the process. A study on storage of foamed and nonfoamed freeze-dried products at 4 °C completed this study. B. longum RO175 in foamed medium could be freeze-dried in 1/7 to 1/4 of the time required for nonfoamed suspensions. In addition, foamed suspensions presented higher viability immediately after freeze-drying (13.6% compared to 12.81 % or 11.46%, depending on the cryoprotective media). Refrigerated storage led to a reduction in B. longum RO175 viability for all tested protective agents (foamed and nonfoamed). No correlation between glass transition temperature and stability of probiotic powders was observed during storage. In addition, lower viability after 56 d of storage was observed for foamed materials, probably due to foam porous structure and higher hygroscopicity, and oxygen presence and moisture pickup during storage. © 2016 Institute of Food Technologists®.

  5. Development and viability of a translocated beaver Castor fiber population in the Netherlands

    NARCIS (Netherlands)

    Nolet, B.A.; Baveco, J.M.

    1996-01-01

    We monitored survival, reproduction and emigration of a translocated beaver Castor fiber population in the Netherlands for five years and used a stochastic model to assess its viability. Between 1988 and 1991, 42 beavers were released in the Biesbosch National Park. The mortality was initially high

  6. Fatalities at wind turbines may threaten population viability of a migratory bat

    Science.gov (United States)

    W.F. Frick; E.F. Baerwald; J.F. Pollock; R.M.R. Barclay; J.A. Szymanski; Ted Weller; A.L. Russell; Susan Loeb; R.A. Medellin; L.P. McGuire

    2017-01-01

    Large numbers of migratory bats are killed every year at wind energy facilities. However, population-level impacts are unknown as we lack basic demographic information about these species. We investigated whether fatalities at wind turbines could impact population viability of migratory bats, focusing on the hoary bat (Lasiurus cinereus),...

  7. Sperm competition and offspring viability at hybridization in Australian tree frogs, Litoria peronii and L. tyleri.

    Science.gov (United States)

    Sherman, C D H; Wapstra, E; Olsson, M

    2010-02-01

    Hybridization between closely related species often leads to reduced viability or fertility of offspring. Complete failure of hybrid offspring (post-zygotic hybrid incompatibilities) may have an important role in maintaining the integrity of reproductive barriers between closely related species. We show elsewhere that in Peron's tree frog, Litoria peronii, males more closely related to a female sire more offspring in sperm competition with a less related rival male. Observations of rare 'phenotypic intermediate' males between L. peronii and the closely related L. tyleri made us suggest that these relatedness effects on siring success may be because of selection arising from risks of costly hybridization between the two species. Here, we test this hypothesis in an extensive sperm competition experiment, which shows that there is no effect of species identity on probability of fertilization in sperm competition trials controlling for sperm concentration and sperm viability. Instead, there was a close agreement between a male's siring success in isolation with a female and his siring success with the same female in competition with a rival male regardless of species identity. Offspring viability and survival, however, were strongly influenced by species identity. Over a 14-day period, hybrid offspring suffered increasing mortality and developed more malformations and an obvious inability to swim and right themselves, leading to compromised probability of survival. Thus, hybridization in these sympatric tree frogs does not compromise fertilization but has a strong impact on offspring viability and opportunity for reinforcement selection on mate choice for conspecific partners.

  8. Viability and Biochemical Content Changes in Seed Storage of Jabon Putih (Anthocephalus Cadamba (Roxb Miq.

    Directory of Open Access Journals (Sweden)

    Naning Yuniarti

    2015-08-01

    Full Text Available Seed deterioration is the process of deteriorated seed in view of viability that changed the physiological and chemical content. The aim of this research is to find out the effect of moisture content and storage on viability and biochemical content of jabon putih seed. Completely Randomized Design was used for decreasing moisture content based on seed drying time for 0, 24, 48, 72, 96, 120 hours, and Completely Randomized Factorial Design was used for the combination of moisture content (drying time for 0, 24, 48, 72, 96, 120 hours and room storage (ambient room, air-conditioned room, refrigerator. The results of this research are: (1 seed drying time and seed storage affected the change of seed viability and biochemical content, (2 seed drying time and seed storage influence significantly the value of moisture content, germination percentage, and biochemical content (lipid, carbohydrate, protein, (3 The longer time of seed drying and seed storage has decreased the seed moisture content, germination percentage, and the carbohydrate content, but it has increased the content of lipid and protein, and (4 the seeds were stored in refrigerator has better viability compared to dry cold storage and ambient room.

  9. Is oxidative stress involved in the loss of neem (Azadirachta indica) seed viability?

    NARCIS (Netherlands)

    Sacandé, M.; Hoekstra, F.A.; Aelst, van A.C.; Vos, de C.H.R.

    2000-01-01

    Neem (Azadirachta indica) is a valuable multipurpose tree of tropical arid and semi-arid regions. The use of its seeds is hindered by their short storage longevity. The possible causes of rapid loss of viability were investigated on different seed lots during exposure to 32% and 75% RH at 20°C.

  10. Viability, Apoptosis, Proliferation, Activation, and Cytokine Secretion of Human Keratoconus Keratocytes after Cross-Linking

    Directory of Open Access Journals (Sweden)

    Xuefei Song

    2015-01-01

    Full Text Available Purpose. The purpose of this study was to determine the impact of cross-linking (CXL on viability, apoptosis, proliferation, activation, and cytokine secretion of human keratoconus (KC keratocytes, in vitro. Methods. Primary KC keratocytes were cultured in DMEM/Ham’s F12 medium supplemented with 10% FCS and underwent UVA illumination (370 nm, 2 J/cm2 during exposure to 0.1% riboflavin and 20% Dextran in PBS. Twenty-four hours after CXL, viability was assessed using Alamar blue assay; apoptosis using APO-DIRECT Kit; proliferation using ELISA-BrdU kit; and CD34 and alpha-smooth muscle actin (α-SMA expression using flow cytometry. Five and 24 hours after CXL, FGFb, HGF, TGFβ1, VEGF, KGF, IL-1β, IL-6, and IL-8 secretion was measured using enzyme-linked-immunoabsorbent assay (ELISA. Results. Following CXL, cell viability and proliferation decreased (P0.06. Five hours after CXL, FGFb secretion increased significantly (P=0.037; however no other cytokine secretion differed significantly from controls after 5 or 24 hours (P>0.12. Conclusions. Cross-linking decreases viability, triggers apoptosis, and inhibits proliferation, without an impact on multipotent hematopoietic stem cell transformation and myofibroblastic transformation of KC keratocytes. CXL triggers FGFb secretion of KC keratocytes transiently (5 hours, normalizing after 24 hours.

  11. Evaluation of skin viability effect on ethosome and liposome-mediated psoralen delivery via cell uptake.

    Science.gov (United States)

    Zhang, Yong-Tai; Shen, Li-Na; Wu, Zhong-Hua; Zhao, Ji-Hui; Feng, Nian-Ping

    2014-10-01

    This study investigated the effect of skin viability on its permeability to psoralen delivered by ethosomes, as compared with liposomes. With decreasing skin viability, the amount of liposome-delivered psoralen that penetrated through the skin increased, whereas skin deposition of psoralen from both ethosomes and liposomes reduced. Psoralen delivery to human-immortalized epidermal cells was more effective using liposomes, whereas delivery to human embryonic skin fibroblast cells was more effective when ethosomes were used. These findings agreed with those of in vivo studies showing that skin psoralen deposition from ethosomes and liposomes first increased and then plateaued overtime, which may indicate gradual saturation of intracellular drug delivery. It also suggested that the reduced deposition of ethosome- or liposome-delivered psoralen in skin with reduced viability may relate to reduced cellular uptake. This work indicated that the effects of skin viability should be taken into account when evaluating nanocarrier-mediated drug skin permeation. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  12. Fluorescence techniques to detect and to assess viability of plant pathogenic bacteria

    NARCIS (Netherlands)

    Chitarra, L.G.

    2001-01-01

    Plant pathogenic bacteria cause major economic losses in commercial crop production worldwide every year. The current methods used to detect and to assess the viability of bacterial pathogens and to test seed lots or plants for contamination are usually based on plate assays or on

  13. Evaluation of endoscopic vein extraction on structural and functional viability of saphenous vein endothelium.

    Science.gov (United States)

    Hussaini, Bader E; Lu, Xiu-Gui; Wolfe, J Alan; Thatte, Hemant S

    2011-06-10

    Endothelial injury during harvest influences graft patency post CABG. We have previously shown that endoscopic harvest causes structural and functional damage to the saphenous vein (SV) endothelium. However, causes of such injury may depend on the extraction technique. In order to assess this supposition, we evaluated the effect of VirtuoSaph endoscopic SV harvesting technique (VsEVH) on structural and functional viability of SV endothelium using multiphoton imaging, biochemical and immunofluorescence assays. Nineteen patients scheduled for CABG were prospectively identified. Each underwent VsEVH for one portion and "No-touch" open SV harvesting (OSVH) for another portion of the SV. A two cm segment from each portion was immersed in GALA conduit preservation solution and transported overnight to our lab for processing. The segments were labeled with fluorescent markers to quantify cell viability, calcium mobilization and generation of nitric oxide. Morphology, expression, localization and stability of endothelial caveolin, eNOS, von Willebrand factor and cadherin were evaluated using immunofluorescence, Western blot and multiphoton microscopy (MPM). Morphological, biochemical and immunofluorescence parameters of viability, structure and function were well preserved in VsEVH group as in OSVH group. However, tonic eNOS activity, agonist-dependent calcium mobilization and nitric oxide production were partially attenuated in the VsEVH group. This study indicates that VirtuoSaph endoscopic SV harvesting technique preserves the structural and functional viability of SV endothelium, but may differentially attenuate the vasomotor function of the saphenous vein graft.

  14. Life history, population viability, and the potential for local adaptation in isolated trout populations

    Science.gov (United States)

    K. J. Carim; Y. Vindenes; L. A. Eby; C. Barfoot; L. A. Vollestad

    2017-01-01

    Habitat loss and fragmentation have caused population decline across taxa through impacts on life history diversity, dispersal patterns, and gene flow. Yet, intentional isolation of native fish populations is a frequently used management strategy to protect against negative interactions with invasive fish species. We evaluated the population viability and genetic...

  15. Viability costs of reproduction and behavioral compensation in western mosquitofish (Gambusia affinis.

    Directory of Open Access Journals (Sweden)

    Clinton T Laidlaw

    Full Text Available The cost of reproduction hypothesis suggests that current reproduction has inherent tradeoffs with future reproduction. These tradeoffs can be both in the form of energy allocated to current offspring as opposed to somatic maintenance and future reproduction (allocation costs, or as an increase in mortality as a result of morphological or physiological changes related to reproduction (viability costs. Individuals may be able to decrease viability costs by altering behavior. Female western mosquitofish, Gambusia affinis experience a reduction in swimming ability as a consequence of pregnancy. We test for a viability cost of reproduction, and for behavioral compensation in pregnant female G. affinis by measuring survival of females in early and later stages of pregnancy when exposed to predation. Late-stage pregnant females experience a 70% greater probability of mortality compared to early-stage pregnant females. The presence of a refuge roughly doubled the odds of survival of both early and late-stage pregnant females. However, there was no interaction between refuge availability and stage of pregnancy. These data do not provide evidence for behavioral compensation by female G. affinis for elevated viability costs incurred during later stages of pregnancy. Behavioral compensation may be constrained by other aspects of the cost of reproduction.

  16. Transcriptional activity around bacterial cell death reveals molecular biomarkers for cell viability

    NARCIS (Netherlands)

    Kort, R.; Keijser, B.J.; Caspers, M.P.M.; Schuren, F.H.; Montijn, R.

    2008-01-01

    Background: In bacteriology, the ability to grow in selective media and to form colonies on nutrient agar plates is routinely used as a retrospective criterion for the detection of living bacteria. However, the utilization of indicators for bacterial viability-such as the presence of specific

  17. Landscape-based population viability models demonstrate importance of strategic conservation planning for birds

    Science.gov (United States)

    Thomas W. Bonnot; Frank R. Thompson; Joshua J. Millspaugh; D. Todd. Jones-Farland

    2013-01-01

    Efforts to conserve regional biodiversity in the face of global climate change, habitat loss and fragmentation will depend on approaches that consider population processes at multiple scales. By combining habitat and demographic modeling, landscape-based population viability models effectively relate small-scale habitat and landscape patterns to regional population...

  18. The JAMM motif of human deubiquitinase Poh1 is essential for cell viability.

    Science.gov (United States)

    Gallery, Melissa; Blank, Jonathan L; Lin, Yinghui; Gutierrez, Juan A; Pulido, Jacqueline C; Rappoli, David; Badola, Sunita; Rolfe, Mark; Macbeth, Kyle J

    2007-01-01

    Poh1 deubiquitinase activity is required for proteolytic processing of polyubiquitinated substrates by the 26S proteasome, linking deubiquitination to complete substrate degradation. Poh1 RNA interference (RNAi) in HeLa cells resulted in a reduction in cell viability and an increase in polyubiquitinated protein levels, supporting the link between Poh1 and the ubiquitin proteasome pathway. To more specifically test for any requirement of the zinc metalloproteinase motif of Poh1 to support cell viability and proteasome function, we developed a RNAi complementation strategy. Effects on cell viability and proteasome activity were assessed in cells with RNAi of endogenous Poh1 and induced expression of wild-type Poh1 or a mutant form of Poh1, in which two conserved histidines of the proposed catalytic site were replaced with alanines. We show that an intact zinc metalloproteinase motif is essential for cell viability and 26S proteasome function. As a required enzymatic component of the proteasome, Poh1 is an intriguing therapeutic drug target for cancer.

  19. Viability costs of reproduction and behavioral compensation in western mosquitofish (Gambusia affinis).

    Science.gov (United States)

    Laidlaw, Clinton T; Condon, Jacob M; Belk, Mark C

    2014-01-01

    The cost of reproduction hypothesis suggests that current reproduction has inherent tradeoffs with future reproduction. These tradeoffs can be both in the form of energy allocated to current offspring as opposed to somatic maintenance and future reproduction (allocation costs), or as an increase in mortality as a result of morphological or physiological changes related to reproduction (viability costs). Individuals may be able to decrease viability costs by altering behavior. Female western mosquitofish, Gambusia affinis experience a reduction in swimming ability as a consequence of pregnancy. We test for a viability cost of reproduction, and for behavioral compensation in pregnant female G. affinis by measuring survival of females in early and later stages of pregnancy when exposed to predation. Late-stage pregnant females experience a 70% greater probability of mortality compared to early-stage pregnant females. The presence of a refuge roughly doubled the odds of survival of both early and late-stage pregnant females. However, there was no interaction between refuge availability and stage of pregnancy. These data do not provide evidence for behavioral compensation by female G. affinis for elevated viability costs incurred during later stages of pregnancy. Behavioral compensation may be constrained by other aspects of the cost of reproduction.

  20. Low nutrient availability reduces high-irradiance–induced viability loss inoceanic phytoplankton

    NARCIS (Netherlands)

    Kulk, G.; van de Poll, W.H.; Visser, R.J.W.; Buma, A.G.J.

    2013-01-01

    In situ viability of oceanic phytoplankton may be relatively low in open oceans. This is assumed to be related to the high-irradiance and low-nutrient conditions typical for oligotrophic regions. However, experimental evidence for this phenomenon was not yet available. In the present study, the