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Sample records for central blood volume

  1. Reduced central blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Bendtsen, F; Henriksen, Jens Henrik Sahl; Sørensen, T I; Stadeager, C; Ring-Larsen, H

    1989-01-01

    The pathogenesis of ascites formation in cirrhosis is uncertain. It is still under debate whether the effective blood volume is reduced (underfilling theory) or whether the intravascular compartment is expanded (overflow theory). This problem has not yet been solved because of insufficient tools...... for measuring the central blood volume. We have developed a method that enables us to determine directly the central blood volume, i.e., the blood volume in the heart cavities, lungs, and central arterial tree. In 60 patients with cirrhosis and 16 control subjects the central blood volume was assessed...... according to the kinetic theory as the product of cardiac output and mean transit time of the central vascular bed. Central blood volume was significantly smaller in patients with cirrhosis than in controls (mean 21 vs. 27 ml/kg estimated ideal body weight, p less than 0.001; 25% vs. 33% of the total blood...

  2. Reduced central blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Bendtsen, Flemming; Sørensen, T I;

    1989-01-01

    was inversely correlated to the systemic vascular resistance (r = -0.49, p less than 0.001), the latter being significantly reduced in the patient group. Patients with cirrhosis apparently are unable to maintain a normal central blood volume. This may be due to arteriolar vasodilation, portosystemic collateral......The pathogenesis of ascites formation in cirrhosis is uncertain. It is still under debate whether the effective blood volume is reduced (underfilling theory) or whether the intravascular compartment is expanded (overflow theory). This problem has not yet been solved because of insufficient tools...... for measuring the central blood volume. We have developed a method that enables us to determine directly the central blood volume, i.e., the blood volume in the heart cavities, lungs, and central arterial tree. In 60 patients with cirrhosis and 16 control subjects the central blood volume was assessed according...

  3. Effect of volume expansion on systemic hemodynamics and central and arterial blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

    1995-01-01

    BACKGROUND & AIMS: Systemic vasodilatation in cirrhosis may lead to hemodynamic alterations with reduced effective blood volume and decreased arterial blood pressure. This study investigates the response of acute volume expansion on hemodynamics and regional blood volumes in patients with cirrhosis...... and in controls. METHODS: Thirty-nine patients with cirrhosis (12 patients with Child-Turcotte class A, 14 with class B, and 13 with class C) and 6 controls were studied. During hepatic vein catheterization, cardiac output, systemic vascular resistance, central and arterial blood volume, noncentral...... change was found in patients with either class B or class C. Conversely, the noncentral blood volume increased in patients with class B and C. In both patients and controls, the cardiac output increased and the systemic vascular resistance decreased, whereas the mean arterial blood pressure did not...

  4. Colloid volume loading does not mitigate decreases in central blood volume during simulated hemorrhage while heat stressed

    DEFF Research Database (Denmark)

    Crandall, Craig G; Wilson, Thad E; Marving, Jens;

    2012-01-01

    attenuates the reduction in regional blood volumes during a simulated hemorrhagic challenge imposed via lower-body negative pressure (LBNP). Seven subjects underwent 30 mmHg LBNP while normothermic, during passive heat stress (increased internal temperature ~1°C), and while continuing to be heated after......±3%; spleen: 72±5%, all P0.05 relative to heat stress alone). These data suggest that blood volume loading during passive heat stress (via 11 ml/kg of a colloid solution) normalizes regional blood volumes in the torso, but does not mitigate the reduction in central blood volume during a simulated hemorrhagic......Heat stress results in profound reductions in the capacity to withstand a simulated hemorrhagic challenge; however, this capacity is normalized if the individual is volume loaded prior to the challenge. The present study tested the hypothesis that volume loading during passive heat stress...

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

    Science.gov (United States)

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

    2015-09-01

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

  6. Decreased right heart blood volume determined by magnetic resonance imaging: evidence of central underfilling in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Søndergaard, L; Møgelvang, J;

    1995-01-01

    ), and end-systolic volumes (RVSV and LVSV) determined by magnetic resonance imaging (MRI). RVDV (122 vs. control 166 mL, P < .02), RVSV (41 vs. 80 mL, P < .02) and right atrial volume (47 vs. 64 mL, P < .05) were significantly reduced in the patients. In contrast, LVDV (134 vs. 129 mL, NS), LVSV (54 vs...... the cardiac output (CO) multiplied by the central circulation time, was significantly decreased (1.47 vs. 1.81 L, P < .05). The noncentral blood volume (4.43 vs. 3.64 L, P < .02), plasma volume (4.05 vs. 3.27 L, P < .02), and CO (7.11 vs. control 5.22 L/min, P < .01) were significantly increased in...

  7. Decreased right heart blood volume determined by magnetic resonance imaging: evidence of central underfilling in cirrhosis

    DEFF Research Database (Denmark)

    Møller, Søren; Søndergaard, Lise; Møgelvang, J; Henriksen, O; Henriksen, Jens Henrik

    1995-01-01

    ), and end-systolic volumes (RVSV and LVSV) determined by magnetic resonance imaging (MRI). RVDV (122 vs. control 166 mL, P < .02), RVSV (41 vs. 80 mL, P < .02) and right atrial volume (47 vs. 64 mL, P < .05) were significantly reduced in the patients. In contrast, LVDV (134 vs. 129 mL, NS), LVSV (54 vs...... the cardiac output (CO) multiplied by the central circulation time, was significantly decreased (1.47 vs. 1.81 L, P <.05). The noncentral blood volume (4.43 vs. 3.64 L, P < .02), plasma volume (4.05 vs. 3.27 L, P < .02), and CO (7.11 vs. control 5.22 L/min, P < .01) were significantly increased in the...

  8. Circulating atrial natriuretic peptide (ANP) and central blood volume (CBV) in cirrhosis

    DEFF Research Database (Denmark)

    Schütten, H J; Henriksen, Jens Henrik Sahl; Bendtsen, F; Warberg, J

    1986-01-01

    ). Arterial plasma concentration of ANP in supine patients was (mean +/- SEM) 33 +/- 4 vs 41 +/- 10 pg/ml (9.9 +/- 1.2 vs 12.3 +/- 3.0 fmol/l) in controls (n.s.), and there was a weak direct correlation with right atrial pressure (r = 0.36, P = 0.05). There was no relationship with the presence of ascites or...... diuretic treatment. Central blood volume (CBV, i.e. the blood volume in the heart cavities, lungs, and aorta), determined from the mean transit time of 125I-labelled of 125I-labelled albumin and cardiac output, was significantly reduced in cirrhotics compared to controls (1.45 +/- 0.12 vs. 1.83 +/- 0.10 l......, P less than 0.02) and inversely correlated with portal pressure (r = 0.42, P less than 0.05), whereas total plasma volume was somewhat increased (3.51 +/- 0.2 vs. 3.19 +/- 0.2, 0.05 less than P less than 0.1). A high arterio-venous extraction of ANP was found in the splanchnic system (extraction...

  9. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas;

    2010-01-01

    from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole......During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading of...... in the SV to PCWP ratio during LBNP was comparable to that observed during normothermia (4.8 +/- 2.3 ml mmHg(1); P = 0.78). These data support the hypothesis that a Frank-Starling mechanism contributes to compromised blood pressure control during simulated haemorrhage in heat-stressed individuals...

  10. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    OpenAIRE

    Bronzwaer, Anne-Sophie G. T.; Stok, Wim J.; Westerhof, Berend E.; Johannes J. van Lieshout

    2014-01-01

    Rationale: A critical reduction in central blood volume (CBV) is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV). Stroke volume index (SVI) serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI a...

  11. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    OpenAIRE

    Anne-SophieG.T.Bronzwaer; WimJ.Stok; BerendE.Westerhof; JohannesJ.Van Lieshout

    2014-01-01

    Rationale: A critical reduction in central blood volume (CBV) is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV). Stroke volume index (SVI) serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI ...

  12. Hemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

    Science.gov (United States)

    Convertino, V. A.; Thompson, C. A.; Benjamin, B. A.; Keil, L. C.; Savin, W. M.; Gordon, E. P.; Haskell, W. L.; Schroeder, J. S.; Sandler, H.

    1990-01-01

    Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in ten cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 deg head down tilt (HDT) followed by 20 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15, and 30 min of HDT, and 5, 15, and 30 min of seated recovery. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Resting plasma volume (PV) was measured by Evans blue dye and percent changes in PV during posture changes were calculated from changes in hematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. Results indicate that cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man.

  13. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas; Secher, N H; Crandall, C G

    During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading of...... heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males...... in the SV to PCWP ratio during LBNP was comparable to that observed during normothermia (4.8 +/- 2.3 ml mmHg(1); P = 0.78). These data support the hypothesis that a Frank-Starling mechanism contributes to compromised blood pressure control during simulated haemorrhage in heat-stressed individuals...

  14. Specificity of Compensatory Reserve and Tissue Oxygenation as Early Predictors of Tolerance to Progressive Reductions in Central Blood Volume.

    Science.gov (United States)

    Howard, Jeffrey T; Janak, Jud C; Hinojosa-Laborde, Carmen; Convertino, Victor A

    2016-09-01

    We previously reported that measurements of muscle oxygen saturation (SmO2) and the compensatory reserve index (CRI) provided earlier indication of reduced central blood volume than standard vital signs (e.g., blood pressure, heart rate, arterial oxygen saturation). In the present study, we hypothesized that the CRI would provide greater sensitivity and specificity to detect progressive decrease in central circulating blood volume compared with SmO2. Continuous noninvasive measures of CRI (calculated from feature changes in the photoplethysmographic arterial waveforms) were collected from 55 healthy volunteer subjects before and during stepwise lower body negative pressure (LBNP) to the onset of hemodynamic decompensation. Near infrared spectroscopy was used on the forearm to obtain deep SmO2, hydrogen ion concentration ([H]), and hemoglobin volume (HbT; decreases reflect vasoconstriction). CRI decreased by 97% in a linear fashion across progressive blood volume loss, with no clinically significant alterations in vital signs. The receiver operating characteristic (ROC) area under the curve (AUC) for the CRI was 0.91, with a sensitivity of 0.87 and specificity of 0.80, when predicting decompensation at progressive levels of LBNP. In comparison, SmO2, [H], and HbT had significantly lower ROC AUC, sensitivity and specificity values for detecting the same outcome. Consistent with our hypothesis, CRI detected central hypovolemia with significantly greater specificity than measures of tissue metabolism. Single measurement of CRI may enable more accurate triage, while CRI monitoring may allow for earlier detection of casualty deterioration. PMID:27058052

  15. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    Directory of Open Access Journals (Sweden)

    Anne-SophieG.T.Bronzwaer

    2014-04-01

    Full Text Available Rationale:\tA critical reduction in central blood volume (CBV is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV. Stroke volume index (SVI serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI and regional brain perfusion during CBV depletion and repletion in spontaneously breathing volunteers. Methods: This study quantified in 14 healthy subjects (11 male the effects of CBV depletion (by 30 and 70 degrees passive head-up tilt (HUT and a fluid challenge (by tilt back on CBV (thoracic admittance, mean middle cerebral artery (MCA blood flow velocity (Vmean, SVI, cardiac index (CI , PPV and SPV. Results: PPV (103±89%, p< 0.05 and SPV (136±117%, p< 0.05 increased with progression of central hypovolemia manifested by a reduction in thoracic admittance (11±5%, p< 0.001, SVI (28±6%, p< 0.001, CI (6±8%, p< 0.001 and MCAVmean (17±7%, p< 0.05 but not in arterial pressure. The reduction in MCAVmean correlated to the fall in SVI (R2=0.52, p< 0.0001 and inversely to PPV and SPV (R2=0.46 (p< 0.0001 and R2=0.45 (p< 0.0001, respectively. PPV and SPV predicted a ≥15% reduction in MCAVmean and SVI with comparable sensitivity (67%/ 67% vs. 63%/ 68% respectively and specificity (89%/94% vs. 89%/94%, respectively. A rapid fluid challenge by tilt-back restored all parameters to baseline values within one minute. Conclusion: In spontaneously breathing subjects, a reduction in MCAVmean was related to an increase in PPV and SPV during graded CBV depletion and repletion. Specifically, PPV and SPV predicted changes in both SVI and MCAVmean with comparable sensitivity and specificity, however the predictive value is limited in spontaneously breathing subjects.

  16. Determinants of the renin-angiotensin-aldosterone system in cirrhosis with special emphasis on the central blood volume

    DEFF Research Database (Denmark)

    Møller, Søren; Bendtsen, Flemming; Henriksen, Jens Henrik

    2006-01-01

    dysfunction and splanchnic and systemic haemodynamics (r = - 0.56-0.55), but only weakly with CBV (r = - 0.25, p < 0.02). In a multivariate regression analysis, plasma renin was determined by serum sodium, alkaline phosphatases and systolic blood pressure (p < 0.04 to p < 0.001). CONCLUSIONS: CBV correlates...... RAAS, including the CBV. Circulating plasma renin concentrations were measured using an immunoradiometric assay. RESULTS: Arterial renin concentrations were significantly higher in the patients than in the controls (p < 0.003). Plasma renin correlated significantly with several indicators of liver...

  17. Cardiac contractility, central haemodynamics and blood pressure regulation during semistarvation

    DEFF Research Database (Denmark)

    Stokholm, K H; Breum, L; Astrup, A

    1991-01-01

    pressure (BP) declined. The fall in BP was caused by the reduction in cardiac output as the total peripheral resistance was unchanged. Finally, the decline in total blood volume was not significant. These findings together with a reduction in heart rate indicated that a reduced sympathetic tone via......Eight obese patients were studied before and after 2 weeks of treatment by a very-low-calorie diet (VLCD). Cardiac output and central blood volume (pulmonary blood volume and left atrial volume) were determined by indicator dilution (125I-albumin) and radionuclide angiocardiography (first pass and...... equilibrium technique by [99Tcm]red blood cells). Cardiac output decreased concomitantly with the reduction in oxygen uptake as the calculated systemic arteriovenous difference of oxygen was unaltered. There were no significant decreases in left ventricular contractility indices, i.e. the ejection fraction...

  18. Photoplethysmographic variability: spontaneous fluctuations in the tissue blood volume and in the systolic blood volume increase

    Science.gov (United States)

    Nitzan, Meir; Babchenko, Anatoly; Turivnenko, Sergei; Khanokh, Boris

    1997-05-01

    Several parameters of the cardiovascular system such as heart rate, arterial blood pressure and blood flow fluctuate spontaneously due to the autonomic nervous system activity. In the current study, the low frequency fluctuations of the tissue blood volume and the blood volume pulse in the fingertips of healthy subjects were investigated using transmission photoplethysmography (PPG). The baseline of the PPG signal (BL) is inversely related to tissue blood volume so that the parameter BV, defined by: BV equals Const.-BL is directly related to the blood volume. The amplitude (AM) is directly related to the systolic blood volume increase. For most of the examinations BV and AM show positive correlation, which is expected since BV depends on the tissue blood volume and AM depends on the compliance of the blood vessels, both of which decrease during vasoconstriction, which is caused by higher activity of the sympathetic nervous system. The analysis of the PPG signal provides, therefore, a potential tool for study in the mechanism of the regulation of the microcirculation by the sympathetic nerves.

  19. Volume reduction in routine cord blood banking.

    Science.gov (United States)

    Solves, Pilar; Mirabet, Vicente; Roig, Roberto

    2010-12-01

    Umbilical cord blood (UCB) is an alternative source of hematopoietic progenitors for transplantation in the treatment of haematological malignancies, marrow failure, immunodeficiencies, hemoglobinopathies and inherited metabolic diseases. It has greatly contributed to increase the feasibility to transplantation for many patients in need. To date, more than 20,000 UCB transplants have been performed on children and adults, and more than 400,000 UCB units are available in more than 50 public CB banks. One of the most important objectives of banks is to cryopreserve and store high quality UCB units. Volume reduction is a usual process in cord blood banking that has some advantages as reducing the storage space and the DMSO quantity in final product. Volume reduction methodology must guarantee high cell recovery and red blood cell (RBC) depletion by reducing the UCB units to a standard volume. Hydroxyethyl starch (HES) sedimentation was the first method developed for this purpose by the New York Cord Blood Bank and implemented in many banks worldwide. The semi-automated top and bottom system, usually used for blood fractionation was further developed to simplify and short the process. Later, automatic devices as SEPAX and AXP have been developed in last years specifically for UCB volume reduction purpose. This review critically analyses the advantages and disadvantages of the different procedures. All of them have been used in Valencia Cord Blood Bank along 10 years. In general, automatic devices are preferred because of compliance with cGTP, closed systems, higher reproducibility and less influence of technician. PMID:20528760

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

    OpenAIRE

    Oh, Won Sup; Chon, Sung-Bin

    2016-01-01

    Fluid resuscitation, hemostasis, and transfusion is essential in care of hemorrhagic shock. Although estimation of the residual blood volume is crucial, the standard measuring methods are impractical or unsafe. Vital signs, central venous or pulmonary artery pressures are inaccurate. We hypothesized that the residual blood volume for acute, non-ongoing hemorrhage was calculable using serial hematocrit measurements and the volume of isotonic solution infused. Blood volume is the sum of volumes...

  1. Noninvasive measurement of pulmonary blood volume

    International Nuclear Information System (INIS)

    In noninvasive estimation of pulmonary blood volume by radionuclide-angiocardiography, a formula was derived from experiments with heart-lung model, and in vivo experiments PBV = CO x PPT x 0.77. The pulmonary blood volume estimated clinically by this formula was in good agreement with the results obtained invasively before. The compliance (δV/δP) of the pulmonary ''venous'' system was calculated by simultaneous measurement of pressure changes in lung field on leg elevation and changes in pulmonary arterial wedge pressure with Swan-Ganz catheter. The compliances which were calculated in 35 cases of heart diseases by this method were in a considerably good agreement with those which were assessed by analysis of a pulmonary arterial wedge pressure tracing. (Ueda, J.)

  2. Ventilatory response in metabolic acidosis and cerebral blood volume in humans.

    NARCIS (Netherlands)

    Ven, M.T.P. van de; Colier, W.N.J.M.; Sluijs, M.C. van der; Oeseburg, B.; Folgering, H.T.M.

    2001-01-01

    The relationship between alterations in cerebral blood volume (CBV) and central chemosensitivity regulation was studied under neutral metabolic conditions and during metabolic acidosis. Fifteen healthy subjects (5610 years) were investigated. To induce metabolic acidosis, ammonium chloride (NH(4)Cl)

  3. Influence of Gravity on Blood Volume and Flow Distribution

    Science.gov (United States)

    Pendergast, D.; Olszowka, A.; Bednarczyk, E.; Shykoff, B.; Farhi, L.

    1999-01-01

    In our previous experiments during NASA Shuttle flights SLS 1 and 2 (9-15 days) and EUROMIR flights (30-90 days) we observed that pulmonary blood flow (cardiac output) was elevated initially, and surprisingly remained elevated for the duration of the flights. Stroke volume increased initially and then decreased, but was still above 1 Gz values. As venous return was constant, the changes in SV were secondary to modulation of heart rate. Mean blood pressure was at or slightly below 1 Gz levels in space, indicating a decrease in total peripheral resistance. It has been suggested that plasma volume is reduced in space, however cardiac output/venous return do not return to 1 Gz levels over the duration of flight. In spite of the increased cardiac output, central venous pressure was not elevated in space. These data suggest that there is a change in the basic relationship between cardiac output and central venous pressure, a persistent "hyperperfusion" and a re-distribution of blood flow and volume during space flight. Increased pulmonary blood flow has been reported to increase diffusing capacity in space, presumably due to the improved homogeneity of ventilation and perfusion. Other studies have suggested that ventilation may be independent of gravity, and perfusion may not be gravity- dependent. No data for the distribution of pulmonary blood volume were available for flight or simulated microgravity. Recent studies have suggested that the pulmonary vascular tree is influenced by sympathetic tone in a manner similar to that of the systemic system. This implies that the pulmonary circulation is dilated during microgravity and that the distribution of blood flow and volume may be influenced more by vascular control than by gravity. The cerebral circulation is influenced by sympathetic tone similarly to that of the systemic and pulmonary circulations; however its effects are modulated by cerebral autoregulation. Thus it is difficult to predict if cerebral perfusion is

  4. Low central venous pressure reduces blood loss in hepatectomy

    Institute of Scientific and Technical Information of China (English)

    Wei-Dong Wang; Li-Jian Liang; Xiong-Qing Huang; Xiao-Yu Yin

    2006-01-01

    AIM: To investigate the effect of low central venous pressure (LCVP) on blood loss during hepatectomy for hepatocellular carcinoma (HCC).METHODS: By the method of sealed envelope,50 HCC patients were randomized into LCVP group (n = 25) and control group (n = 25). In LCVP group,CVP was maintained at 2-4 mmHg and systolic blood pressure (SBP) above 90 mmHg by manipulation of the patient's posture and administration of drugs during hepatectomy, while in control group hepatectomy was performed routinely without lowering CVP. The patients'preoperative conditions, volume of blood loss during hepatectomy, volume of blood transfusion, length of hospital stay, changes in hepatic and renal functions were compared between the two groups.RESULTS: There were no significant differences in patients' preoperative conditions, maximal tumor dimension, pattern of hepatectomy, duration of vascular occlusion, operationtime, weight of resected liver tissues, incidence of post-operative complications, hepatic and renal functions between the two groups. LCVP group had a markedly lower volume of total intraoperative blood loss and blood loss during hepatectomy than the control group, being 903.9±180.8 mL vs 2 329.4±2 538.4(W=495.5, P<0.01) and 672.4±429.9 mL vs1 662.6± 1932.1 (W=543.5, P<0.01). There were no remarkable differences in the pre-resection and post-resection blood losses between the two groups. The length of hospital stay was significantly shortened in LCVP group as compared with the control group, being 16.3±6.8 d vs21.5 ± 8.6 d (W= 532.5, P<0.05).CONCLUSION: LCVP is easily achievable in technique.Maintenance of CVP≤4 mmHg can help reduce blood loss during hepatectomy, shorten the length of hospital stay, and has no detrimental effects on hepatic or renal function.

  5. Determination of the blood volume of rabbits (1963)

    International Nuclear Information System (INIS)

    The knowledge of the ratio of the blood volume to the weight of an animal is of a great deal in various experiments. Therefore authors have decided to determine this ratio for rabbits by using chromium 51. Results show that the blood volume represents about 54.4 g per kilogram of body weight. (authors)

  6. Pulmonary blood volume measured by RI angiocardiography

    International Nuclear Information System (INIS)

    RI angiocardiography (RACG) was performed in 81 patients with heart disease without congestive heart failure at the time, and the results were compared between the groups with mitral valve disease and other diseases. Cardiac output (CO) and pulmonary mean transit time (PMTT) were compared with the results from the dye dilution method in the same patients. PMTT directly measured by RACG was also compared with the peak to peak time (P-PT). P-PT was expressed as the distance from the right to the left peak time in radiocardiography (RCG). There were good correlations between the CO and PMTT obtained from the RI method and those of the dye dilution method (r = 0.90, r = 0.84). The ralationship between PMTT and P-PT in mitral valve disease was different from that of other diseases. The average value of PMTT was 5.2 +- 1.0 seconds, and pulmonary blood volume (PBV) was 315 +- 57 ml/m2 in the control group. The PBV values were markedly increased in patients with mitral stenosis (558 +- 132 ml/m2) and mitral regurgitation (444 +- 119 ml/m2), and were slightly increased in aortic valve disease, congenital shunt disease and cardiomyopathy. The patients with ischemic heart disease had normal PBV. In mitral valve disease, the direct method using PMTT of RACG is more accurate than the presumption method using P-PT of RCG. The determination of PBV by this method is very important to observe hemodynamic states in mitral valve disease. (J.P.N.)

  7. Continuous monitoring of blood volume changes in humans

    Science.gov (United States)

    Hinghofer-Szalkay, H.; Greenleaf, J. E.

    1987-01-01

    Use of on-line high-precision mass densitometry for the continuous monitoring of blood volume changes in humans was demonstrated by recording short-term blood volume alterations produced by changes in body position. The mass density of antecubital venous blood was measured continuously for 80 min per session with 0.1 g/l precision at a flow rate of 1.5 ml/min. Additional discrete plasma density and hematocrit measurements gave linear relations between all possible combinations of blood density, plasma density, and hematocrit. Transient filtration phenomena were revealed that are not amenable to discontinuous measurements.

  8. On-line dynamic measurement of blood viscosity, hematocrit and change of blood volume

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To develop an on-line system for the measurement of blood viscosity and hematocrit. The dynamic changes of the macrovascular blood volumes,microvascular blood volumes and the total blood volume were observed by means of calculating from the testing result. Methods: Applying traditional viscosity measurement principle and specific wavelength optic density measurement method, an on-line system for the measurement of blood viscosity and hematocrit was developed, and the A/D multifunctionai board and the testing circuit were designed by ourselves. The system was validated by experiments both in vitro and in vivo. Therapeutic effects of hypertonic saline dextran solution (HSD) and Lactatic Ringer's solution at the early stage after burn-blast combined injury were compared by this method. Results: The results showed that the system has attained the goal of the design. The changes of the blood viscosity and hematocrit could be detected effectively and continuously. The changes of macrovascular, microvascular and total blood volume could be calculated approximately. Conclusions: The system and the method can continuously on-line test the blood viscosity and hematocrit, and reveal the change and distribution of blood volumes more accurately and dearly in the therapy process by estimating changes of the macrovascular, microvascular and total blood volumes, respectively. It has confirmed that HSD treatment could increase blood pressure and attenuate tissue edema by significantly increasing total blood volume,improving macrocirculatory and microcirculatory blood volumes. This study suggested that it could be desirable to develop an experiment technique based on the method mentioned above.

  9. Determination of blood volume by pulse CO-oximetry

    International Nuclear Information System (INIS)

    The objective of this study was to determine whether changes in carboxyhaemoglobin (COHb) saturation following carbon monoxide (CO) rebreathing can be accurately detected by pulse CO-oximetry in order to determine blood volume. Noninvasive measurements of carboxyhaemoglobin saturation (SpCO) were continuously monitored by pulse CO-oximetry before, during and following 2 min of CO rebreathing. Reproducibility and accuracy of noninvasive blood volume measurements were determined in 16 healthy non-smoking individuals (15 males, age: 28 ± 2 years, body mass index: 25.4 ± 0.6 kg m−2) through comparison with blood volume measurements calculated from invasive measurements of COHb saturation. The coefficient of variation for noninvasive blood volume measurements performed on separate days was 15.1% which decreases to 9.1% when measurements were performed on the same day. Changes in COHb saturation and SpCO following CO rebreathing were strongly correlated (r = 0.90, p < 0.01), resulting in a significant correlation between invasive and noninvasive blood volume measurements (r = 0.83, p = 0.02). Changes in SpCO following CO rebreathing can be accurately detected by pulse CO-oximetry, which could potentially provide a simplified, convenient and reproducible method to rapidly determine blood volume in healthy individuals

  10. RELATIVE BLOOD VOLUME: THE MEANS OF INTRADIALYSIS HYPOTENSION PREVENTION

    OpenAIRE

    V. A. Terehov; A. G. Strokov

    2010-01-01

    Intravascular volume preservation is the first choice measure for the prevention of intradialysis hypotension. At present there are devices that allow continuous monitoring of relative blood volume (RBV) changes during haemodialysis (HD). The aim of this research was to investigate (i) the regularity of RBV curve during haemo- dialysis and (ii) the efficacy of some measures for intravascular volume preservation. In patients with hyperhydration RBV curves were monotone; in all cases relation ...

  11. Brachial versus central blood pressure and vascular stiffness

    DEFF Research Database (Denmark)

    Rasmussen, Susanne; Hansen, Tine; Frimodt-Møller, Marie

    2010-01-01

    Central blood pressure (BP) estimates the true load imposed on the left ventricle to a higher degree than does brachial BP. Increased aortic pulse wave velocity (aPWV) and central BP are risk markers for cardiovascular disease. Both can be measured by simple and noninvasive methods. Guidelines...

  12. Pulmonary blood volume and transit time in cirrhosis: relation to lung function

    DEFF Research Database (Denmark)

    Møller, Søren; Burchardt, H; Øgard, CG;

    2006-01-01

    BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis and...... cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis....

  13. Pulmonary blood volume and transit time in cirrhosis: relation to lung function

    DEFF Research Database (Denmark)

    Møller, Søren; Burchardt, H; Øgard, CG;

    2006-01-01

    BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis....... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis and...

  14. The determination of chromium-50 in human blood and its utilization for blood volume measurements

    International Nuclear Information System (INIS)

    Possible relationships between insufficient blood volume increases during pregnancy and infant mortality could be established with an adequate measurement procedure. An accurate and precise technique for blood volume measurements has been found in the isotope dilution technique using chromium-51 as a label for red blood cells. However, in a study involving pregnant women, only stable isotopes can be used for labeling. Stable chromium-50 can be determined in total blood samples before and after dilution experiments by neutron activation analysis (NAA) or mass spectrometry. However, both techniques may be affected by insufficient sensitivity and contamination problems at the inherently low natural chromium concentrations to be measured in the blood. NAA procedures involving irradiations with highly thermalized neutrons at a fluence rate of 2x1013 n/cm2xs and low background gamma spectrometry are applied to the analysis of total blood. Natural levels of chromium-50 in human and animal blood have been found to be <0.1 ng/mL; i.e., total chromium levels of <3 ng/mL. Based on the NAA procedure, a new approach to the blood volume measurement via chromium-50 isotope dilution has been developed which utilizes the ratio of the induced activities of chromium-51 to the iron-59 in three blood samples taken from each individual, namely blank, labeled and diluted labeled blood. (author)

  15. Errors of the backextrapolation method in determination of the blood volume

    Science.gov (United States)

    Schröder, T.; Rösler, U.; Frerichs, I.; Hahn, G.; Ennker, J.; Hellige, G.

    1999-01-01

    Backextrapolation is an empirical method to calculate the central volume of distribution (for example the blood volume). It is based on the compartment model, which says that after an injection the substance is distributed instantaneously in the central volume with no time delay. The occurrence of recirculation is not taken into account. The change of concentration with time of indocyanine green (ICG) was observed in an in vitro model, in which the volume was recirculating in 60 s and the clearance of the ICG could be varied. It was found that the higher the elimination of ICG, the higher was the error of the backextrapolation method. The theoretical consideration of Schröder et al ( Biomed. Tech. 42 (1997) 7-11) was proved. If the injected substance is eliminated somewhere in the body (i.e. not by radioactive decay), the backextrapolation method produces large errors.

  16. [Correlation between the regional blood volume and epileptic seizures in Papio papio].

    Science.gov (United States)

    Ancri, D; Naquet, R; Basset, J Y; Ménini, C; Lonchampt, M F; Meldrum, B S; Stutzmann, J M

    1979-07-16

    The method of labelling red cells with technetium-99m was used to measured regional blood volume auring different types of epileptic seizures induced in the Baboon Papio papio. During seizures the cerebral blood volume increases and there is simultaneously a decrease of blood volume in nasal and hepatic regions, and a transitory increase of blood volume in the forepaws. PMID:117933

  17. Study on the Correlation of Central Venous Pressure with Intrathoracic Blood Volume Index and Global End-Diastolic Volume Index after Pulmonary Lobectomy%肺手术后中心静脉压与血容量指数、全心舒张末期容积指数的相关性研究

    Institute of Scientific and Technical Information of China (English)

    王素梅; 黎阳; 黄冰; 茅乃权; 阮林; 彭丹晖; 杜学柯

    2013-01-01

    Objective To investigate the correlation of central venous pressure ( CVP ) with intrathoracic blood volume index(ITBVI) and global end-diastolic volume index(GEDVI) after pulmonary lobectomy,and to dis-cuss the value of CVP as a parameter of volume load after pulmonary lobectomy .Methods Twenty-three cases of ASA I-II grade lung cancer who underwent radical resection were enrolled in the study .Pulse indicator continuous cardiac output ( PiCCO) monitoring technology was used to record their postoperative CVP ,GEDVI and ITBVI at the time of off-lining(T1),after tracheal extubation instantly(T2),2 hours after extubation(T3),5 hours after extubation ( T4 ) ,and 15 hours after extubation ( T5 ) .The correlation of CVP with ITBVI and GEDVI was analyzed .Results The correlation coefficient of CVP and GEDVI was equal to -0 .138 ( P>0 .05 ); The correlation coefficient of CVP and ITBVI was equal to -0.153(P>0.05).Conclusion CVP can not indicate the volume load of patients after pulmonary lobectomy .It should be based on the clinical features or using more monitoring techniques when performing load monitoring and evaluation .%目的:探讨肺手术患者术后胸腔内血容量指数( ITBVI)、全心舒张末期容积指数( GEDVI)与中心静脉压( CVP)的相关性,研究肺手术后CVP用于评价肺手术后容量负荷的价值。方法 ASAⅠ~Ⅱ级行肺癌根治术患者23例,术后应用脉搏指示剂心排量连续监测( PiCCO)技术监测患者脱机后( T1)、拔管后( T2)、拔管后2h(T3)、拔管后5 h(T4)、拔管后15 h(T5)的CVP、ITBVI、GEDVI,分析CVP与ITBVI、GEDVI的相关性。结果 CVP与GEDVI的相关系数为r=-0.138(P>0.05); CVP与ITBVI r为-0.153(P>0.05)。结论CVP不能反映肺手术后机体的容量状态,在容量监测与评估时要根据临床表现或增加其他监测手段。

  18. 21 CFR 862.1130 - Blood volume test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood volume test system. 862.1130 Section 862.1130 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  19. A reference frame for blood volume in children and adolescents

    Directory of Open Access Journals (Sweden)

    Donckerwolcke Raymond

    2006-02-01

    Full Text Available Abstract Background Our primary purpose was to determine the normal range and variability of blood volume (BV in healthy children, in order to provide reference values during childhood and adolescence. Our secondary aim was to correlate these vascular volumes to body size parameters and pubertal stages, in order to determine the best normalisation parameter. Methods Plasma volume (PV and red cell volume (RCV were measured and F-cell ratio was calculated in 77 children with idiopathic nephrotic syndrome in drug-free remission (mean age, 9.8 ± 4.6 y. BV was calculated as the sum of PV and RCV. Due to the dependence of these values on age, size and sex, all data were normalised for body size parameters. Results BV normalised for lean body mass (LBM did not differ significantly by sex (p Conclusion LBM was the anthropometric index most closely correlated to vascular fluid volumes, independent of age, gender and pubertal stage.

  20. Arterial hypertension in cirrhosis: arterial compliance, volume distribution, and central haemodynamics

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Fuglsang, S; Bendtsen, F;

    2006-01-01

    BACKGROUND AND AIMS: Arterial hypertension is a common disorder. Hyperkinetic circulation and reduced effective volaemia are central elements in the haemodynamic dysfunction in cirrhosis. The aim of the present study was to investigate whether cirrhotic patients with arterial hypertension are...... normokinetic and normovolaemic or whether they reveal the same circulatory dysfunction as their normotensive counterparts. MATERIAL AND METHODS: Thirty three patients with arterial hypertension were identified among 648 patients with cirrhosis: 14 in Child class A, 12 in class B, and seven in class C. Controls...... were 130 normotensive cirrhotic patients, 19 controls with normal arterial blood pressure and without liver disease, and 16 patients with essential arterial hypertension. All groups underwent haemodynamic investigation with determination of cardiac output (CO), plasma volume (PV), central blood volume...

  1. Daily liquorice consumption for two weeks increases augmentation index and central systolic and diastolic blood pressure.

    Directory of Open Access Journals (Sweden)

    Miia H Leskinen

    Full Text Available Liquorice ingestion often elevates blood pressure, but the detailed haemodynamic alterations are unknown. We studied haemodynamic changes induced by liquorice consumption in 20 subjects versus 30 controls with average blood pressures of 120/68 and 116/64 mmHg, respectively.Haemodynamic variables were measured in supine position before and after two weeks of liquorice consumption (daily glycyrrhizin dose 290-370 mg with tonometric recording of radial blood pressure, pulse wave analysis, and whole-body impedance cardiography. Thirty age-matched healthy subjects maintaining their normal diet were studied as controls.Two weeks of liquorice ingestion elevated peripheral and central systolic and diastolic blood pressure (by 7/4 and 8/4 mmHg, 95% confidence intervals [CI] 2-11/1-8 and 3-13/1-8, respectively, P<0.05, and increased extracellular volume by 0.5 litres (P<0.05 versus controls. Also augmentation index adjusted to heart rate 75/min (from 7% to 11%, 95% CI for change 0.3-7.5, P<0.05 and aortic pulse pressure (by 4 mmHg, 95% CI 1-7, P<0.05 were elevated indicating increased wave reflection from the periphery. In contrast, peripheral (-3/-0.3 mmHg and central blood pressure (-2/-0.5 mmHg, aortic pulse pressure (-1 mmHg, and augmentation index adjusted to heart rate 75/min (from 9% to 7% decreased numerically but not statistically significantly without changes in extracellular volume in the control group. Heart rate, systemic vascular resistance, cardiac output, and pulse wave velocity did not differ between the groups.Two weeks of daily liquorice consumption increased extracellular volume, amplified pressure wave reflection from the periphery, and elevated central systolic and diastolic blood pressure.EU Clinical Trials Register EudraCT 2006-002065-39 ClinicalTrials.gov NCT01742702.

  2. Changes in circulating blood volume following isoflurane or sevoflurane anesthesia.

    Science.gov (United States)

    Hamada, H; Takaori, M; Kimura, K; Fukui, A; Fujita, Y

    1993-07-01

    Changes of circulating blood volume (CB volume) measured by the dual indicator dilution method were observed in 33 chronically instrumented mongrel dogs following either alpha-chloralose-urethane (C group), additive isoflurane (I group) or sevoflurane anesthesia (S group). These anesthetic groups were each divided into two subgroups with regard to respiratory care, namely Cp, Ip and Sp for those with intermittent positive pressure ventilation (six animals per subgroups), and Cs, Is and Ss for those with spontaneous breathing (five animals per subgroups). The CB volume under positive pressure ventilation remained unchanged in the Ip and Sp groups at both 0.5 and 1.0 MAC, and in the Cp group. The CB volume remained essentially unchanged in the Cs and Is groups at both 0.5 or 1.0 MAC, but the plasma volume tended to increase slightly in the Is group at 1.0 MAC. In the Ss group under spontaneous breathing, however, the CB volume increased from 84.4 +/- 7.0 to 91.4 +/- 7.7 at 0.5 MAC, and to 91.4 +/- 10.2 ml.kg(-1) at 1.0 MAC (0.01 < P < 0.05). These increases were caused by an increase in the plasma volume. The above data suggests that a concomitant increase in the venous pressure associated with an increase in the intrathoracic pressure produced by positive pressure ventilation would attenuate changes in the CB volume during sevoflurane anesthesia. PMID:15278818

  3. Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload

    Institute of Scientific and Technical Information of China (English)

    Mike; Saddon; Karen; McNeil; Philip; Chowienczyk

    2009-01-01

    Objective To determine whether reduction in central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-load or is due to arterial dilation. Methods We compared effects of NTG with those of lower body negative pressure (LBNP). Hemodynamic measurements were made at rest,during LBNP (10,20 and 30 mmHg,each for 15 min) and after NTG (10,30 and 100 μg/min,each dose for 15 min) in ten healthy volunteers. Cardiac pre-load,stroke volume and cardiac output w...

  4. Quantification of cardiopulmonary blood volume turnover using dynamic PET

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Kero, Tanja;

    index, the central circulatory turnover (CCT) which represents the fractional exchange of blood per stroke within the cardiopulmonary blood pool and can be measured from any dynamic PET scan. Methods: Data from 111 clinical patients were analysed retrospectively. Patients underwent a 6-min 15O...... and RV time-activity curves were extracted after which their first-pass peaks were isolated and the centroid of each peak was obtained. Mean pulmonary transit time (MPTT, min) was defined as the difference between the LV centroid and the RV centroid and CCT was defined as 1/(MPTT*heart rate). Results.......001). Decrease of CCT was especially pronounced in severely ischemic patients already at rest Conclusion: Pulmonary transit times and central circulatory turnover can be measured automatically using dynamic PET. Since both are correlated with severity of myocardial ischemia already at rest, they appear to...

  5. Accuracy of a new bedside method for estimation of circulating blood volume

    DEFF Research Database (Denmark)

    Christensen, P; Waever Rasmussen, J; Winther Henneberg, S

    1993-01-01

    To evaluate the accuracy of a modification of the carbon monoxide method of estimating the circulating blood volume.......To evaluate the accuracy of a modification of the carbon monoxide method of estimating the circulating blood volume....

  6. Habitual intake of fruit juice predicts central blood pressure.

    Science.gov (United States)

    Pase, Matthew P; Grima, Natalie; Cockerell, Robyn; Pipingas, Andrew

    2015-01-01

    Despite a common perception that fruit juice is healthy, fruit juice contains high amounts of naturally occurring sugar without the fibre content of the whole fruit. Frequent fruit juice consumption may therefore contribute to excessive sugar consumption typical of the Western society. Although excess sugar intake is associated with high blood pressure (BP), the association between habitual fruit juice consumption and BP is unclear. The present study investigated the association of fruit juice consumption with brachial and central (aortic) BP in 160 community dwelling adults. Habitual fruit juice consumption was measured using a 12 month dietary recall questionnaire. On the same day, brachial BP was measured and central (aortic) BP was estimated through radial artery applanation. Frequency of fruit juice consumption was classified as rare, occasional or daily. Those who consumed fruit juice daily, versus rarely or occasionally, had significantly higher central systolic BP (F (2, 134) = 6.09, p <0.01), central pulse pressure (F (2, 134) = 4.16, p <0.05), central augmentation pressure (F (2, 134) = 5.98, p <0.01) and central augmentation index (F (2, 134) = 3.29, p <0.05) as well as lower pulse pressure amplification (F (2, 134) = 4.36, p <0.05). There were no differences in brachial BP. Central systolic BP was 3-4 mmHg higher for those who consumed fruit juice daily rather than rarely or occasionally. In conclusion, more frequent fruit juice consumption was associated with higher central BPs. PMID:25278432

  7. Variations in gastric compliance induced by acute blood volume changes in anesthetized rats

    Directory of Open Access Journals (Sweden)

    Graça J.R.V.

    2002-01-01

    Full Text Available The impact of acute volume imbalances on gastric volume (GV was studied in anesthetized rats (250-300 g. After cervical and femoral vessel cannulation, a balloon catheter was positioned in the proximal stomach. The opposite end of the catheter was connected to a barostat with an electronic sensor coupled to a plethysmometer. A standard ionic solution was used to fill the balloon (about 3.0 ml and the communicating vessel system, and to raise the reservoir liquid level 4 cm above the animals' xiphoid appendix. Due to constant barostat pressure, GV values were considered to represent the gastric compliance index. All animals were monitored for 90 min. After a basal interval, they were randomly assigned to normovolemic, hypervolemic, hypovolemic or restored protocols. Data were compared by ANOVA followed by Bonferroni's test. Mean arterial pressure (MAP, central venous pressure (CVP and GV values did not change in normovolemic animals (N = 5. Hypervolemic animals (N = 12 were transfused at 0.5 ml/min with a suspension of red blood cells in Ringer-lactate solution with albumin (12.5 ml/kg, which reduced GV values by 11.3% (P0.05. MAP and CVP values increased (P<0.05 after hypervolemia but decreased (P<0.05 with hypovolemia. In conclusion, blood volume level modulates gastric compliance, turning the stomach into an adjustable reservoir, which could be part of the homeostatic process to balance blood volume.

  8. A single-centre study of vasovagal reaction in blood donors: Influence of age, sex, donation status, weight, total blood volume and volume of blood collected

    Directory of Open Access Journals (Sweden)

    Joseph Philip

    2014-01-01

    Full Text Available Context: Vasovagal reactions (VVRs in blood donors. Aim: To find an association of age, sex, donation status, weight, total blood volume and volume of blood collected with occurrence of immediate VVR. Settings and Design: Retrospective single-centre study. Materials and Methods: The study was conducted from March 2000 to November 2010 at a tertiary care blood transfusion centre. All VVRs with or without syncope occurring during or at the end of donation were noted. Statistical Analysis Used: For qualitative association, c 2 -test was used. Unpaired ′t′ test was used for assessing difference between two groups with respect to VVR status. Simultaneous impact of all risk factors was assessed using multivariate logistic regression analysis. The data entry software SPSS (version 17.0 was used for statistical analysis. A P-value <0.05 was considered statistically significant. Results: Overall 1085 VVRs were reported in relation to 88,201 donations, resulting in an overall VVR rate of 1.23%, that is, an incidence of 1 in every 81 donations. Donors with low blood volume, first-time donors, with low weight and female donors had higher absolute donation VVR rates than other donors. Conclusions: Donation-related vasovagal syncopal reactions are a multifactorial process determined largely by weight, age, first-time donor status and total blood volume. Our study reinforces the fact that blood donation is a very safe procedure, which could be made even more event-free by following certain friendly, reassuring practices and by ensuring strict pre-donation screening procedures.

  9. Acute blood volume expansion delays the gastrointestinal transit of a charcoal meal in awake rats

    Directory of Open Access Journals (Sweden)

    de-Oliveira G.R.

    1998-01-01

    Full Text Available The present study evaluates the effect of blood volume expansion on the gastrointestinal transit of a charchoal meal (2.5 ml of an aqueous suspension consisting of 5% charcoal and 5% gum arabic in awake male Wistar rats (200-270 g. On the day before the experiments, the rats were anesthetized with ether, submitted to left jugular vein cannulation and fasted with water ad libitum until 2 h before the gastrointestinal transit measurement. Blood volume expansion by iv infusion of 1 ml/min Ringer bicarbonate in volumes of 3, 4 or 5% body weight delayed gastrointestinal transit at 10 min after test meal administration by 21.3-26.7% (P<0.05, but no effect was observed after 1 or 2% body weight expansion. The effect of blood volume expansion (up to 5% body weight on gastrointestinal transit lasted for at least 60 min (P<0.05. Mean arterial pressure increased transiently and central venous pressure increased and hematocrit decreased (P<0.05. Subdiaphragmatic vagotomy and yohimbine (3 mg/kg prevented the delay caused by expansion on gastrointestinal transit, while atropine (0.5 mg/kg, L-NAME (2 mg/kg, hexamethonium (10 mg/kg, prazosin (1 mg/kg or propranolol (2 mg/kg were ineffective. These data show that blood volume expansion delays the gastrointestinal transit of a charcoal meal and that vagal and yohimbine-sensitive pathways appear to be involved in this phenomenon. The delay in gastrointestinal transit observed here, taken together with the modifications of gastrointestinal permeability to salt and water reported by others, may be part of the mechanisms involved in liquid excess management.

  10. RELATIVE BLOOD VOLUME: THE MEANS OF INTRADIALYSIS HYPOTENSION PREVENTION

    Directory of Open Access Journals (Sweden)

    V. A. Terehov

    2010-06-01

    Full Text Available Intravascular volume preservation is the first choice measure for the prevention of intradialysis hypotension. At present there are devices that allow continuous monitoring of relative blood volume (RBV changes during haemodialysis (HD. The aim of this research was to investigate (i the regularity of RBV curve during haemo- dialysis and (ii the efficacy of some measures for intravascular volume preservation. In patients with hyperhydration RBV curves were monotone; in all cases relation RBV/ ultrafiltration volume (UF did not exceed 2,5%/L. In stable patients the RBV curve was immutable in the course of years. Patients with high RBV/UF ratio (>6%/L formed a high risk group. In these patients stability of RBV was more im- portant and more useful. Isolated UF did not decrease RBV drop, as well as haemodiafiltration online. Albumin administration allows to decrease RBV/UF ratio. After bolus of hypertonic dextrose solution RBV increased for about half of hour. In patients with acute renal injury RBV monitoring was far from reliability in many cases. 

  11. Venous flow velocity, venous volume and arterial blood flow

    International Nuclear Information System (INIS)

    The relationship of arterial blood flow and venous volume to venous flow velocity was studied in normal subjects. The effects of current modes of treatment in venous thrombosis and of a vasodilator drug on venous flow velocity were also investigated. Total calf flow and venous volume were measured by venous occlusion plethysmography while venous flow axial velocity was determined by the transit time of 131I albumin from calf to inguinal region. Local intravenous epinephrine administration induced venoconstriction and increased venous flow velocity. Intra-arterial isoproterenol and angiotensin increased and decreased arterial flow, respectively, with no change in venous flow velocity or volume, but local heat increased arterial flow and venous flow velocity with no change in venous volume. Local cold, despite venoconstriction, decreased venous flow velocity accompanied by decreased arterial flow. Intravenous heparin did not affect venous flow velocity. Intravenous but not oral nylidrin increased venous flow velocity. Therefore venous flow velocity can be significantly increased by venoconstriction, by large increases in arterial flow (local heat), and by a parenteral vasodilator drug. These experiments indicate that there is a basis for applying heat but not cold in the prevention and treatment of venous thrombosis

  12. Resistance exercise with different volumes: blood pressure response and forearm blood flow in the hypertensive elderly

    OpenAIRE

    Brito AF; Oliveira CV; Brasileiro-Santos MS; Santos AC

    2014-01-01

    Aline de Freitas Brito,1 Caio Victor Coutinho de Oliveira,2 Maria do Socorro Brasileiro-Santos,1 Amilton da Cruz Santos1 1Physical Education Department, 2Research Laboratory for Physical Training Applied to Performance and Health, Federal University of Paraíba, João Pessoa, Brazil Background: The purpose of this study was to evaluate the effect of two sessions of resistance exercise with different volumes on post-exercise hypotension, forearm blood flow, and forearm vascular re...

  13. Selective Heart Rate Reduction With Ivabradine Increases Central Blood Pressure in Stable Coronary Artery Disease.

    Science.gov (United States)

    Rimoldi, Stefano F; Messerli, Franz H; Cerny, David; Gloekler, Steffen; Traupe, Tobias; Laurent, Stéphane; Seiler, Christian

    2016-06-01

    Heart rate (HR) lowering by β-blockade was shown to be beneficial after myocardial infarction. In contrast, HR lowering with ivabradine was found to confer no benefits in 2 prospective randomized trials in patients with coronary artery disease. We hypothesized that this inefficacy could be in part related to ivabradine's effect on central (aortic) pressure. Our study included 46 patients with chronic stable coronary artery disease who were randomly allocated to placebo (n=23) or ivabradine (n=23) in a single-blinded fashion for 6 months. Concomitant baseline medication was continued unchanged throughout the study except for β-blockers, which were stopped during the study period. Central blood pressure and stroke volume were measured directly by left heart catheterization at baseline and after 6 months. For the determination of resting HR at baseline and at follow-up, 24-hour ECG monitoring was performed. Patients on ivabradine showed an increase of 11 mm Hg in central systolic pressure from 129±22 mm Hg to 140±26 mm Hg (P=0.02) and in stroke volume by 86±21.8 to 107.2±30.0 mL (P=0.002). In the placebo group, central systolic pressure and stroke volume remained unchanged. Estimates of myocardial oxygen consumption (HR×systolic pressure and time-tension index) remained unchanged with ivabradine.The decrease in HR from baseline to follow-up correlated with the concomitant increase in central systolic pressure (r=-0.41, P=0.009) and in stroke volume (r=-0.61, Phttp://www.clinicaltrials.gov. Unique identifier NCT01039389. PMID:27091900

  14. Hippocampal volume reduction in congenital central hypoventilation syndrome.

    Directory of Open Access Journals (Sweden)

    Paul M Macey

    Full Text Available Children with congenital central hypoventilation syndrome (CCHS, a genetic disorder characterized by diminished drive to breathe during sleep and impaired CO(2 sensitivity, show brain structural and functional changes on magnetic resonance imaging (MRI scans, with impaired responses in specific hippocampal regions, suggesting localized injury.We assessed total volume and regional variation in hippocampal surface morphology to identify areas affected in the syndrome. We studied 18 CCHS (mean age+/-std: 15.1+/-2.2 years; 8 female and 32 healthy control (age 15.2+/-2.4 years; 14 female children, and traced hippocampi on 1 mm(3 resolution T1-weighted scans, collected with a 3.0 Tesla MRI scanner. Regional hippocampal volume variations, adjusted for cranial volume, were compared between groups based on t-tests of surface distances to the structure midline, with correction for multiple comparisons. Significant tissue losses emerged in CCHS patients on the left side, with a trend for loss on the right; however, most areas affected on the left also showed equivalent right-sided volume reductions. Reduced regional volumes appeared in the left rostral hippocampus, bilateral areas in mid and mid-to-caudal regions, and a dorsal-caudal region, adjacent to the fimbria.The volume losses may result from hypoxic exposure following hypoventilation during sleep-disordered breathing, or from developmental or vascular consequences of genetic mutations in the syndrome. The sites of change overlap regions of abnormal functional responses to respiratory and autonomic challenges. Affected hippocampal areas have roles associated with memory, mood, and indirectly, autonomic regulation; impairments in these behavioral and physiological functions appear in CCHS.

  15. Resistance exercise with different volumes: blood pressure response and forearm blood flow in the hypertensive elderly

    Directory of Open Access Journals (Sweden)

    Brito AF

    2014-12-01

    Full Text Available Aline de Freitas Brito,1 Caio Victor Coutinho de Oliveira,2 Maria do Socorro Brasileiro-Santos,1 Amilton da Cruz Santos1 1Physical Education Department, 2Research Laboratory for Physical Training Applied to Performance and Health, Federal University of Paraíba, João Pessoa, Brazil Background: The purpose of this study was to evaluate the effect of two sessions of resistance exercise with different volumes on post-exercise hypotension, forearm blood flow, and forearm vascular resistance in hypertensive elderly subjects.Methods: The study was conducted with ten hypertensive elderly (65±3 years, 28.7±3 kg/m2 subjected to three experimental sessions, ie, a control session, exercise with a set (S1, and exercise with three sets (S3. For each session, the subjects were evaluated before and after intervention. In the pre-intervention period, blood pressure, forearm blood flow, and forearm vascular resistance were measured after 10 minutes of rest in the supine position. Thereafter, the subjects were taken to the gym to perform their exercise sessions or remained at rest during the same time period. Both S1 and S3 comprised a set of ten repetitions of ten exercises, with an interval of 90 seconds between exercises. Subsequently, the measurements were again performed at 10, 30, 50, 70, and 90 minutes of recovery (post-intervention in the supine position.Results: Post-exercise hypotension was greater in S3 than in S1 (systolic blood pressure, −26.5±4.2 mmHg versus −17.9±4.7 mmHg; diastolic blood pressure, −13.8±4.9 mmHg versus −7.7±5 mmHg, P<0.05. Similarly, forearm blood flow and forearm vascular resistance changed significantly in both sessions with an increase and decrease, respectively, that was more evident in S3 than in S1 (P<0.05.Conclusion: Resistance exercises with higher volume were more effective in causing post-exercise hypotension, being accompanied by an increase in forearm blood flow and a reduction of forearm vascular

  16. Oxygenation and Blood Volume Periodic Waveforms in the Brain

    CERN Document Server

    Gersten, Alexander; Raz, Amir

    2011-01-01

    Results of an experiment are presented whose aim is to explore the relationship between respiration and cerebral oxygenation. Measurements of end tidal CO2 (EtCO2) were taken simultaneously with cerebral oxygen saturation (rSO2) using the INVOS Cerebral Oximeter of Somanetics. Due to the device limitations we could explore only subjects who could perform with a breathing rate of around 2/min or less. Six subjects were used who were experienced in yoga breathing techniques. They performed an identical periodic breathing exercise including periodicity of about 2/min. The results of all six subjects clearly show a periodic change of cerebral oxygenation with the same period as the breathing exercises. Similar periodic changes in blood volume index were observed as well.

  17. Peripheral and Central Effects of Melatonin on Blood Pressure Regulation

    Directory of Open Access Journals (Sweden)

    Olga Pechanova

    2014-10-01

    Full Text Available The pineal hormone, melatonin (N-acetyl-5-methoxytryptamine, shows potent receptor-dependent and -independent actions, which participate in blood pressure regulation. The antihypertensive effect of melatonin was demonstrated in experimental and clinical hypertension. Receptor-dependent effects are mediated predominantly through MT1 and MT2 G-protein coupled receptors. The pleiotropic receptor-independent effects of melatonin with a possible impact on blood pressure involve the reactive oxygen species (ROS scavenging nature, activation and over-expression of several antioxidant enzymes or their protection from oxidative damage and the ability to increase the efficiency of the mitochondrial electron transport chain. Besides the interaction with the vascular system, this indolamine may exert part of its antihypertensive action through its interaction with the central nervous system (CNS. The imbalance between the sympathetic and parasympathetic vegetative system is an important pathophysiological disorder and therapeutic target in hypertension. Melatonin is protective in CNS on several different levels: It reduces free radical burden, improves endothelial dysfunction, reduces inflammation and shifts the balance between the sympathetic and parasympathetic system in favor of the parasympathetic system. The increased level of serum melatonin observed in some types of hypertension may be a counter-regulatory adaptive mechanism against the sympathetic overstimulation. Since melatonin acts favorably on different levels of hypertension, including organ protection and with minimal side effects, it could become regularly involved in the struggle against this widespread cardiovascular pathology.

  18. Pulmonary blood volume (PRV) in rats with chronic mountain sickness

    International Nuclear Information System (INIS)

    Upon chronic exposure to severe hypoxia, Hilltop (H) strain of Sprague-Dawley rats develops excessive polycythemia, severe hypervolemia and marked elevation in pulmonary arterial pressure (PAP), whereas Madison (M) strain develops only moderate responses. Hypervolemia is expected to increase the PBV which might contribute to the development of severe pulmonary hypertension. Two groups of 6 animals each of the H and M strains were exposed to sea level (SL) and a simulated altitude of 18,000 ft for 14 days. At the end of exposure each animal was measured for RBC volume (RBCV), total blood volume (TBV), PBV and PAP under normoxia for control and under hypoxia (10% O2) for the hypoxic groups. RBCV was determined by 51Cr-RBC dilution and PBV was trapped by tightening an implanted loose ligature around the ascending aorta and PA. There were not strain differences in all parameters studied at SL. RBCV, TBV and PAP increased with hypoxia in both strains but significantly more so in H than M. PBV per g lung WT decreased in both strains despite elevated TBV and PAP, but more so in M than H. There were good correlations between the PBV and TBV, and between PAP and PBV in the hypoxic H and M rats. The data suggest that chronic hypoxia reduced the distensibility and perhaps the vascular capacity of the lungs such that small relative increase in PBV could significantly contribute to the rise in PAP

  19. [Effects of volume and rate of blood loss on indicators of auto-hemodilution].

    Science.gov (United States)

    Koval'skaia, K S; Baluev, E P; Krivitskiĭ, N M

    1991-06-01

    The results of synchronous monitoring of blood impedance versus body impedance in dog experiments showed that the speed of physiological hemodilution related to blood loss up to 30 ml/kg is poorly dependent on the rate of blood loss (0.4-1.0 ml/kg/min) and averages 0.186 +/- 0.02 ml/min/kg. Termination of blood loss is followed by marked reduction in the rate of auto-hemodilution. In bloodletting the studies revealed a linear dependence between the volume of blood loss up to 30 ml/kg and tissue fluid volume entering the blood stream. In blood loss intestinal absorption of fluid does not block the fluid introduction from the interstice. When associated, both these flows increase volume of fluid filling vascular bed and promote stable recovery of the baseline circulating blood volume. PMID:1893173

  20. Determination of the total blood volume of the rat using chromium 51 (1962)

    International Nuclear Information System (INIS)

    In various experiments it is important that the rat's blood volume should be known and it is essential that it could be worked out by simply weighing the animal. Therefore authors decided to work out systematically with chromium 51 blood volume for rats with different weights. Results have shown that blood volume for 100 g is 5.55 ml and that it does not seen to vary with the weight of animals. (authors)

  1. Correlation between stroke volume variation and blood volume during hypovolemia%低血容量状态下患者每搏量变异度与血容量的相关性

    Institute of Scientific and Technical Information of China (English)

    李文静; 李健; 彭科

    2014-01-01

    Objective To investigate the correlation between stroke volume variation (SVV) and blood volume during hypovolemia.Methods Twenty ASA Ⅰ or Ⅱ patients,aged 20-64 years,with body mass index (BMI) of 20-30 kg/m2,scheduled for elective orthopedic operation were enrolled in this study.Anesthesia was induced with dexamethasone,midazolam,propofol,fentanyl and cisatracurium,and maintained with sevoflurane,fentanyl and cisatracurium.Then the patients received endotracheal intubation and mechanical ventilation.Heart rate (HR),mean arterial blood pressure (MAP),central venous pressure (CVP),arterial pressure-based cardiac output (APCO),SW,systemic vascular resistance (SVR) and cardiac index (Cl) were recorded 5 minutes after endotracheal intubation.Blood was taken from the central vein at a rate of 30-50 ml/min and the volume was 5% of the whole blood volume,and then haemodynamic parameters mentioned above were recorded after the haemodynamics were kept stable for 5 minutes.Blood was taken again with the method mentioned above and the haemodynamic parameters were recorded.Then 6% hydroxyethyl starch (HES) 130/0.4 was infused at 50-70 ml/min via the right internal jugular vein,and the volume was equal to 5% of the whole blood volume,and then haemodynamic parameters were recorded after the haemodynamics was kept stable for 5 minutes.Fluid replacement was performed again using the method mentioned above and the haemodynamic parameters were recorded.Linear correlation of the changes in blood volume (difference between the blood volume at each time point and the baseline value) with dSVV (difference between the value monitored at each time point and the baseline value) was analyzed.Results Significant changes were found in SW,APCO and Cl after each change in blood volume (P < 0.05 or 0.01),while no significant changes were found in HR,MAP,CVP and SVR after each change in blood volume.The change in blood volume was negatively correlated with dSVV (r =-0.875,P < 0

  2. On-line dialysate infusion to estimate absolute blood volume in dialysis patients.

    Science.gov (United States)

    Schneditz, Daniel; Schilcher, Gernot; Ribitsch, Werner; Krisper, Peter; Haditsch, Bernd; Kron, Joachim

    2014-01-01

    It was the aim to measure the distribution volume and the elimination of ultra-pure dialysate in stable hemodialysis patients during on-line hemodiafiltration (HDF). Dialysate was automatically infused as a volume indicator using standard on-line HDF equipment. Indicator concentration was noninvasively measured in the arterial blood-line (using the blood volume monitor, Fresenius Medical Care, Bad Homburg vor der Höhe, Germany), and its time course was analyzed to obtain the elimination rate and the distribution volume V(t) at the time of dilution. Blood volume at treatment start (V0) was calculated accounting for the degree of intradialytic hemoconcentration. Five patients (two females) were studied during 15 treatments. Two to six measurements using indicator volumes ranging from 60 to 210 ml were done in each treatment. V0 was 4.59 ± 1.15 L and larger than the volume of 4.08 ± 0.48 L estimated from anthropometric relationships. The mean half-life of infused volume was 17.2 ± 29.7 min. Given predialysis volume expansion V0 was consistent with blood volume determined from anthropometric measurements. Information on blood volume could substantially improve volume management in hemodialysis patients and fluid therapy in intensive care patients undergoing extracorporeal blood treatment. The system has the potential for complete automation using proper control inputs for BVM and HDF modules of the dialysis machine. PMID:24814842

  3. Do distribution volumes and clearances relate to tissue volumes and blood flows? A computer simulation

    Directory of Open Access Journals (Sweden)

    Lemmens Hendrikus JM

    2006-06-01

    Full Text Available Abstract Background Kinetics of inhaled agents are often described by physiological models. However, many pharmacokinetic concepts, such as context-sensitive half-times, have been developed for drugs described by classical compartmental models. We derived classical compartmental models that describe the course of the alveolar concentrations (FA generated by the physiological uptake and distribution models used by the Gas Man® program, and describe how distribution volumes and clearances relate to tissue volumes and blood flows. Methods Gas Man® was used to generate FA vs. time curves during the wash-in and wash-out period of 115 min each with a high fresh gas flow (8 L.min-1, a constant alveolar minute ventilation (4 L.min-1, and a constant inspired concentration (FI of halothane (0.75%, isoflurane (1.15%, sevoflurane (2%, or desflurane (6%. With each of these FI, simulations were ran for a 70 kg patient with 5 different cardiac outputs (CO (2, 3, 5, 8 and 10 L.min-1 and for 5 patients with different weights (40, 55, 70, 85, and 100 kg but the same CO (5 L.min-1. Two and three compartmental models were fitted to FA of the individual 9 runs using NONMEM. After testing for parsimony, goodness of fit was evaluated using median prediction error (MDPE and median absolute prediction error (MDAPE. The model was tested prospectively for a virtual 62 kg patient with a cardiac output of 4.5 L.min-1 for three different durations (wash-in and wash-out period of 10, 60, and 180 min each with an FI of 1.5% halothane, 1.5% isoflurane, sevoflurane 4%, or desflurane 12%. Results A three-compartment model fitted the data best (MDPE = 0% and MDAPE ≤ 0.074% and performed equally well when tested prospectively (MDPE ≤ 0.51% and MDAPE ≤ 1.51%. The relationship between CO and body weight and the distribution volumes and clearances is complex. Conclusion The kinetics of anesthetic gases can be adequately described e by a mammilary compartmental model. Therefore

  4. A NEW RECIPE FOR OBTAINING CENTRAL VOLUME DENSITIES OF PRESTELLAR CORES FROM SIZE MEASUREMENTS

    International Nuclear Information System (INIS)

    We propose a simple analytical method for estimating the central volume density of prestellar molecular cloud cores from their column density profiles. Prestellar cores feature a flat central part of the column density and volume density profiles of the same size indicating the existence of a uniform-density inner region. The size of this region is set by the thermal pressure force which depends only on the central volume density and temperature of the core, and can provide a direct measurement of the central volume density. Thus, a simple length measurement can immediately yield a central density estimate independent of any dynamical model for the core and without the need for fitting. Using the radius at which the column density is 90% of the central value as an estimate of the size of the flat inner part of the column density profile yields an estimate of the central volume density within a factor of two for well-resolved cores.

  5. Analysis of reasons for discarding blood and blood components in a blood bank of tertiary care hospital in central India: A prospective study

    OpenAIRE

    Alok Kumar; Satish Sharma,; Narayan Shyamrao Ingole; Nitin Gangane

    2014-01-01

    Background: Many modern surgical procedures could not be carried out without the use of blood. There are no substitutes for human blood. Thus, proper utilization of blood is necessary with minimal wasting. Materials and Methods: A total of 10,582 donors donated blood during the study period of 19 months in blood bank of a tertiary care hospital, central India from 1 st of November 2009 to 31 st May 2011, which were screened. Results: A total of 346 whole blood bags were discarded. Out of thes...

  6. Decreased myocardial blood volume is a cause of reduced myocardial blood flow reserve in hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    The purposes of this study are to know whether myocardial blood volume (MBV) is decreased in the left ventricular myocardium of patients with hypertrophic cardiomyopathy (HCM), and to elucidate which of the decreased MBV or of the reduced rate (mean transit rate of the blood) of myocardial blood flow (MBF), is the cause of the reduced MBF at reactive hyperemia. Subjects were 22 non-obstructive HCM patients (M16/F6, mean age 54 y) exhibiting asymmetric ventricular septum hypertrophy in echocardiography (EC) and 9 male age-matched healthy volunteers. The machine used for EC was Sonos 5500 (Philips Medical Systems) and myocardial contrast EC (MCE) was conducted also with the machine and S3 probe with 1.3/2.6 MHz to get harmonic power Doppler image. The contrast medium was Levovist (Schering AG), which was intravenously infused continuously during EC, and adenosine 5'-triphosphate (ATP) was similarly given to induce the reactive hyperemia. MCE images were processed by the software VoluMap-445 (YD LTD) for calculating MBV (%; mL/100 mL). For obtaining MBF (mL/min/g), positron emission tomography (PET) was done with the machine Siemens/CTI ECAT EXACT HR+Scanner, using 15O-water prepared in Sumitomo cyclotron CYPRIS-HM18, in 13 patients and all volunteers. The mean transit rate was calculated by (MBF/MBV) x 1.67/sec. It was found that MBV was decreased relatedly with the local wall thickness of HCM patients' left ventricular myocardium and MBF was reduced dependently on the decreased MBV at the reactive hyperemia. (R.T.)

  7. Cerebral blood volume, genotype and chemosensitivity in oligodendroglial tumours

    Energy Technology Data Exchange (ETDEWEB)

    Jenkinson, Michael D. [Walton Centre for Neurology and Neurosurgery, Department of Neurosurgery, Liverpool (United Kingdom); University of Liverpool, Division of Neuroscience, Liverpool (United Kingdom); Smith, Trevor S. [Walton Centre for Neurology and Neurosurgery, Department of Neuroradiology, Liverpool (United Kingdom); Joyce, Kathy A.; Fildes, Diane [JK Douglas Laboratories, Clatterbridge Cancer Research Trust, Wirral (United Kingdom); Broome, John [Walton Centre for Neurology and Neurosurgery, Department of Neuropathology, Liverpool (United Kingdom); Plessis, Daniel G. du [University of Liverpool, Division of Neuroscience, Liverpool (United Kingdom); Haylock, Brian; Husband, David J. [Clatterbridge Hospital, Clatterbridge Centre for Oncology, Neuro-Oncology, Wirral (United Kingdom); Warnke, Peter C. [Leibniz Institute for Neurobiology, Magdeburg (Germany); Walker, Carol [University of Liverpool, Division of Neuroscience, Liverpool (United Kingdom); JK Douglas Laboratories, Clatterbridge Cancer Research Trust, Wirral (United Kingdom)

    2006-10-15

    The biological factors responsible for differential chemoresponsiveness in oligodendroglial tumours with or without the -1p/-19q genotype are unknown, but tumour vascularity may contribute. We aimed to determine whether dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) could distinguish molecular subtypes of oligodendroglial tumour, and examined the relationship between relative cerebral blood volume (rCBV) and outcome following procarbazine, lomustine and vincristine (PCV) chemotherapy. Pretherapy rCBV was calculated and inter- and intraobserver variability assessed. Allelic imbalance in 1p36, 19q13, 17p13, 10p12-15, and 10q22-26 and p53 mutation (exons 5-8) were determined. rCBV was compared with genotype and clinicopathological characteristics (n=37) and outcome following PCV chemotherapy (n=33). 1p/19q loss was seen in 6/9 grade II oligodendrogliomas, 6/14 grade II oligoastrocytomas, 4/4 grade III oligodendrogliomas, and 3/10 grade III oligoastrocytomas. rCBV measurements had good inter- and intraobserver variability, but did not distinguish histology subtype or grade. Tumours with 1p/19q loss had higher rCBV values (Student's t-test P=0.001). Receiver operating characteristic analysis revealed a cut-off of 1.59 for identifying genotype (sensitivity 92%, specificity 76%). Tumours with high and low rCBV showed response to chemotherapy. The -1p/-19q genotype, but not rCBV, was strongly associated with response, progression-free and overall survival following PCV chemotherapy. Tumours with high rCBV and intact 1p/19q were associated with shorter progression-free and overall patient survival than those with intact 1p/19q and low rCBV or high rCBV and 1p/19q loss. (orig.)

  8. 24-hour central blood pressure and intermediate cardiovascular phenotypes in untreated subjects

    OpenAIRE

    Bednarek, Agnieszka; Jankowski, Piotr; Olszanecka, Agnieszka; Windak, Adam; Kawecka-Jaszcz, Kalina; Czarnecka, Danuta

    2014-01-01

    Background: Recently, 24-hour monitoring of central systolic blood pressure (SBP) has become available. However, the relation between end-organ damage and the 24-hour central SBP profile and variability has not so far been analyzed. Therefore, the aim of this cross-sectional study was to evaluate the relation between 24-hour central SBP, 24-hour central SBP profile as well as central SBP short-term variability and parameters of cardiac and vascular intermediate phenotypes. Methods: The study ...

  9. Changes in circulating blood volume after infusion of hydroxyethyl starch 6% in critically ill patients

    DEFF Research Database (Denmark)

    Christensen, P; Andersson, J; Rasmussen, S E; Andersen, P K; Henneberg, S W

    2001-01-01

    The cardiovascular response to a volume challenge with hydroxyethyl starch (HES) (200/0.5) 6% depends on the relation between the volume of HES 6% infused and the expansion of the blood volume in critically ill patients. However, only relatively limited data exist on the plasma expanding effect o...... infusion of HES 6% in critically ill patients. The purpose of the study was to evaluate the variation in the expansion of the circulating blood volume (CBV) in critically ill patients after infusion of 500 ml of colloid (HES (200/0.5) 6%) using the carbon monoxide method.......The cardiovascular response to a volume challenge with hydroxyethyl starch (HES) (200/0.5) 6% depends on the relation between the volume of HES 6% infused and the expansion of the blood volume in critically ill patients. However, only relatively limited data exist on the plasma expanding effect of...

  10. 3-D volume reconstruction of skin lesions for melanin and blood volume estimation and lesion severity analysis.

    Science.gov (United States)

    D'Alessandro, Brian; Dhawan, Atam P

    2012-11-01

    Subsurface information about skin lesions, such as the blood volume beneath the lesion, is important for the analysis of lesion severity towards early detection of skin cancer such as malignant melanoma. Depth information can be obtained from diffuse reflectance based multispectral transillumination images of the skin. An inverse volume reconstruction method is presented which uses a genetic algorithm optimization procedure with a novel population initialization routine and nudge operator based on the multispectral images to reconstruct the melanin and blood layer volume components. Forward model evaluation for fitness calculation is performed using a parallel processing voxel-based Monte Carlo simulation of light in skin. Reconstruction results for simulated lesions show excellent volume accuracy. Preliminary validation is also done using a set of 14 clinical lesions, categorized into lesion severity by an expert dermatologist. Using two features, the average blood layer thickness and the ratio of blood volume to total lesion volume, the lesions can be classified into mild and moderate/severe classes with 100% accuracy. The method therefore has excellent potential for detection and analysis of pre-malignant lesions. PMID:22829392

  11. Analysis of reasons for discarding blood and blood components in a blood bank of tertiary care hospital in central India: A prospective study

    Directory of Open Access Journals (Sweden)

    Alok Kumar

    2014-01-01

    Full Text Available Background: Many modern surgical procedures could not be carried out without the use of blood. There are no substitutes for human blood. Thus, proper utilization of blood is necessary with minimal wasting. Materials and Methods: A total of 10,582 donors donated blood during the study period of 19 months in blood bank of a tertiary care hospital, central India from 1 st of November 2009 to 31 st May 2011, which were screened. Results: A total of 346 whole blood bags were discarded. Out of these 346 blood bags, 257 (74.30% were discarded because of seropositivity for transfusion transmissible infectious diseases. A total of 542 blood components were discarded against 3702 blood components prepared during the study period. Among blood components discarded, most common units were platelets. The most common cause of discarding the blood components was expiry of date due to non-utilization (87.00%. Conclusion: A properly conducted donor interview, notification of permanently deferred donors will help in discarding less number of bags from collected units. Similarly, properly implemented blood transfusion policies will also help in discarding less number of blood bags due to expiry. These discarded bags, because they are unutilized are both financially as well as socially harmful to the blood bank.

  12. Radionuclide assessment of peripheral hemodynamics: a new technique for measurement of forearm blood volume and flow

    Energy Technology Data Exchange (ETDEWEB)

    Todo, Y.; Tanimoto, M.; Yamamoto, T.; Iwasaki, T.

    1986-02-01

    A new peripheral hemodynamic measurement system using /sup 99m/Tc-labeled red blood cells has been developed. This method was carried out on 22 normal subjects, 29 with coronary artery disease, and two with dilated cardiomyopathy. Peripheral hemodynamic indices obtained from this method included forearm blood volume (FBV), venous capacity (FVC), venous capacity index (VCI), blood flow (FBF), and vascular resistance (FVR), and were compared with the central hemodynamic parameters of left ventricular filling pressure (LVFP), cardiac output (CO), and total systemic vascular resistance (TSVR) obtained with an invasive technique. The normal values were FBV 8.54 +/- 2.04 ml/100 ml; FVC 4.54 +/- 1.23 ml/100 ml; VCI 65.5 +/- 3.8%; FBF 4.26 +/- 0.56 ml/100 ml/min; and FVR 20.9 +/- 4.4 mmHg/ml/100 ml/min. These values were in good agreement with the values reported using conventional plethysmography. The 16 patients with congestive heart failure (NYHA Class II or III) showed significantly lower FBV, FVC, and FBF values and significantly higher VCI and FVR values than the healthy subjects. Capacitance vessel parameters (FBV, FVC, and VCI) and LVFP, FBF and CO, and FVR and TSVR each showed significant correlation; reproducibility was also good. The advantages of this method are (a) the detector does not come in contact with the region being measured; (b) it is possible to ascertain the absolute quantity of blood in the tissue; (c) extravasation of the plasma component can be ignored; and (d) data processing is simple.

  13. Radionuclide assessment of peripheral hemodynamics: a new technique for measurement of forearm blood volume and flow

    International Nuclear Information System (INIS)

    A new peripheral hemodynamic measurement system using /sup 99m/Tc-labeled red blood cells has been developed. This method was carried out on 22 normal subjects, 29 with coronary artery disease, and two with dilated cardiomyopathy. Peripheral hemodynamic indices obtained from this method included forearm blood volume (FBV), venous capacity (FVC), venous capacity index (VCI), blood flow (FBF), and vascular resistance (FVR), and were compared with the central hemodynamic parameters of left ventricular filling pressure (LVFP), cardiac output (CO), and total systemic vascular resistance (TSVR) obtained with an invasive technique. The normal values were FBV 8.54 +/- 2.04 ml/100 ml; FVC 4.54 +/- 1.23 ml/100 ml; VCI 65.5 +/- 3.8%; FBF 4.26 +/- 0.56 ml/100 ml/min; and FVR 20.9 +/- 4.4 mmHg/ml/100 ml/min. These values were in good agreement with the values reported using conventional plethysmography. The 16 patients with congestive heart failure (NYHA Class II or III) showed significantly lower FBV, FVC, and FBF values and significantly higher VCI and FVR values than the healthy subjects. Capacitance vessel parameters (FBV, FVC, and VCI) and LVFP, FBF and CO, and FVR and TSVR each showed significant correlation; reproducibility was also good. The advantages of this method are (a) the detector does not come in contact with the region being measured; (b) it is possible to ascertain the absolute quantity of blood in the tissue; (c) extravasation of the plasma component can be ignored; and (d) data processing is simple

  14. Altered baseline blood volume and the norepinephrine response to stress in humans

    Science.gov (United States)

    Vernikos, J.; Convertino, V. A.

    1992-01-01

    A hypothesis is proposed that a primary physiological purpose of the neural and endocrine response to stressors is the preservation of the blood volume/blood pressure relationship. Changes in blood volume caused by an adaptation to the environmental challenge serve to modulate the neural and endocrine responsiveness to stress. Relationships between changes in vascular volume, vasoconstriction, and norepinephrine (NE) responses during acute and chronic exposure to various stressors are examined. It is noted that the hypothesis is based on numerous observations rather than definitive cause-effect experiments and further investigation is required to prove it.

  15. Public awareness of blood donation in Central Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abolfotouh MA

    2014-08-01

    Full Text Available Mostafa A Abolfotouh,1,2 Mohammed H Al-Assiri,1 Manar Al-Omani,2 Alwaleed Al Johar,3 Abdulaziz Al Hakbani,3 Ahmed S Alaskar1,2 1King Abdullah International Medical Research Center, 2King Saud bin-Abdulaziz University for Health Sciences, 3College of Medicine, King Saud University, Riyadh, Saudi Arabia Introduction: In Saudi Arabia, voluntary donors are the only source of blood donation. The aim of this study was to assess the level of public knowledge and attitude toward blood donation in Saudi Arabia. Methods: Using a previously validated questionnaire that comprises 38 questions to assess the levels of knowledge, attitudes, and motivations towards blood donation, 469 Saudi adults who attended different shopping malls in Riyadh, Saudi Arabia were surveyed. Multiple regression analyses were used to identify the significant predictors of blood donation, with the significance set at P<0.05. Results: Approximately half of all subjects (53.3% reported that they had previously donated blood, 39% of whom had donated more than once. The knowledge percentage mean score was 58.07%, denoting a poor level of knowledge, with only 11.9% reporting a good level of knowledge. The attitude percentage mean score towards donation was 75.45%, reflecting a neutral attitude towards donating blood, with 31.6% reporting a positive attitude. Donation was significantly more prevalent among males than females (66% versus 13.3%; P<0.001. After adjustment for confounders, a higher knowledge score (t=2.59; P=0.01, a higher attitude score (t=3.26; P=0.001, and male sex (t=10.45; P<0.001 were significant predictors of blood donation. An inability to reach the blood donation centers and a fear of anemia were the main reasons for females not donating blood (49.9% and 35.7%, respectively, whereas a lack of time was the main reason for males (59.5%. Conclusion: Prevalence of blood donation was less than satisfactory among the Saudi public, probably due to misconceptions, poor

  16. C-arm flat detector computed tomography parenchymal blood volume imaging: the nature of parenchymal blood volume parameter and the feasibility of parenchymal blood volume imaging in aneurysmal subarachnoid haemorrhage patients

    Energy Technology Data Exchange (ETDEWEB)

    Kamran, Mudassar; Byrne, James V. [University of Oxford, Nuffield Department of Surgical Sciences, Oxford (United Kingdom)

    2015-09-15

    C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) measurements allow assessment of cerebral haemodynamics in the neurointerventional suite. This paper explores the feasibility of C-arm computed tomography (CT) PBV imaging and the relationship between the C-arm CT PBV and the MR-PWI-derived cerebral blood volume (CBV) and cerebral blood flow (CBF) parameters in aneurysmal subarachnoid haemorrhage (SAH) patients developing delayed cerebral ischemia (DCI). Twenty-six patients with DCI following aneurysmal SAH underwent a research C-arm CT PBV scan using a biplane angiography system and contemporaneous MR-PWI scan as part of a prospective study. Quantitative whole-brain atlas-based volume-of-interest analysis in conjunction with Pearson correlation and Bland-Altman tests was performed to explore the agreement between C-arm CT PBV and MR-derived CBV and CBF measurements. All patients received medical management, while eight patients (31 %) underwent selective intra-arterial chemical angioplasty. Colour-coded C-arm CT PBV maps were 91 % sensitive and 100 % specific in detecting the perfusion abnormalities. C-arm CT rPBV demonstrated good agreement and strong correlation with both MR-rCBV and MR-rCBF measurements; the agreement and correlation were stronger for MR-rCBF relative to MR-rCBV and improved for C-arm CT PBV versus the geometric mean of MR-rCBV and MR-rCBF. Analysis of weighted means showed that the C-arm CT PBV has a preferential blood flow weighting (∼60 % blood flow and ∼40 % blood volume weighting). C-arm CT PBV imaging is feasible in DCI following aneurysmal SAH. PBV is a composite perfusion parameter incorporating both blood flow and blood volume weightings. That PBV has preferential (∼60 %) blood flow weighting is an important finding, which is of clinical significance when interpreting the C-arm CT PBV maps, particularly in the setting of acute brain ischemia. (orig.)

  17. Orthostatic leg blood volume changes assessed by near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Truijen, J; Kim, Y S; Krediet, C T P;

    2012-01-01

    Standing up shifts blood to dependent parts of the body, and blood vessels in the leg become filled. The orthostatic blood volume accumulation in the small vessels is relatively unknown, although these may contribute significantly. We hypothesized that in healthy humans exposed to the upright pos...... suggest a non-linear accumulation of blood volume in the small vessels of the leg, with an initial fast phase followed by a more gradual increase at least partly contributing to the relocation of fluid during orthostatic stress....

  18. Blood volume, plasma volume and circulation time in a high-energy-demand teleost, the yellowfin tuna (Thunnus albacares)

    Science.gov (United States)

    Brill; Cousins; Jones; p

    1998-06-01

    We measured red cell space with 51Cr-labeled red blood cells, and dextran space with 500 kDa fluorescein-isothiocyanate-labeled dextran (FITC-dextran), in two groups of yellowfin tuna (Thunnus albacares). Red cell space was 13.8+/-0.7 ml kg-1 (mean +/- s.e.m.) Assuming a whole-body hematocrit equal to the hematocrit measured at the ventral aortic sampling site and no significant sequestering of 51Cr-labeled red blood cells by the spleen, blood volume was 46. 7+/-2.2 ml kg-1. This is within the range reported for most other teleosts (30-70 ml kg-1), but well below that previously reported for albacore (Thunnus alalunga, 82-197 ml kg-1). Plasma volume within the primary circulatory system (calculated from the 51Cr-labeled red blood cell data) was 32.9+/-2.3 ml kg-1. Dextran space was 37.0+/-3.7 ml kg-1. Because 500 kDa FITC-dextran appeared to remain within the vascular space, these data imply that the volume of the secondary circulatory system of yellowfin tuna is small, and its exact volume is not measurable by our methods. Although blood volume is not exceptional, circulation time (blood volume/cardiac output) is clearly shorter in yellowfin tuna than in other active teleosts. In a 1 kg yellowfin tuna, circulation time is approximately 0.4 min (47 ml kg-1/115 ml min-1 kg-1) compared with 1. 3 min (46 ml kg-1/35 ml min-1 kg-1) in yellowtail (Seriola quinqueradiata) and 1.9 min (35 ml kg-1/18 ml min-1 kg-1) in rainbow trout (Oncorhynchus mykiss). In air-breathing vertebrates, high metabolic rates are necessarily correlated with short circulation times. Our data are the first to imply that a similar relationship occurs in fishes. PMID:9450974

  19. The effect of chronic erythrocytic polycythemia and high altitude upon plasma and blood volumes.

    Science.gov (United States)

    Burton, R. R.; Smith, A. H.

    1972-01-01

    Comparison of two kinds of physiological chronic erythrocytic polycythemias in order to differentiate the specific effect of erythrocytic polycythemia from the general effects of high altitude upon the plasma volume. The two kinds were produced hormonally in female chickens, at sea level, or by protracted high-altitude exposures. It appears that the vascular system of the body may account for an increase in red blood cell mass either by reduction in plasma volume, or by no change in plasma volume, resulting in differential changes in total blood volumes.

  20. Changes in circulating blood volume after infusion of hydroxyethyl starch 6% in critically ill patients

    DEFF Research Database (Denmark)

    Christensen, P; Andersson, J; Rasmussen, S E;

    2001-01-01

    The cardiovascular response to a volume challenge with hydroxyethyl starch (HES) (200/0.5) 6% depends on the relation between the volume of HES 6% infused and the expansion of the blood volume in critically ill patients. However, only relatively limited data exist on the plasma expanding effect of...... infusion of HES 6% in critically ill patients. The purpose of the study was to evaluate the variation in the expansion of the circulating blood volume (CBV) in critically ill patients after infusion of 500 ml of colloid (HES (200/0.5) 6%) using the carbon monoxide method....

  1. Blood safety measures and the role of central blood institute in Japan

    Institute of Scientific and Technical Information of China (English)

    Kenji Tadokoro

    2010-01-01

    @@ 1 Japanese Blood Programme Japanese Red Cross Blood Service is the sole conductor of blood service in Japan. It collects 5.3 million volun-tary non-remunerated donations from 127 million popu-lations and distributes 18 million units ( one unit = 200 ml,2 million Liter) blood matching the medical needs.A part of plasma is supplied to the JRCBS fractionation center and other 3 commercial manufacturers for pro-duction of plasma derivatives.

  2. Are you bleeding? Validation of a machine-learning algorithm for determination of blood volume status: application to remote triage.

    Science.gov (United States)

    Rickards, Caroline A; Vyas, Nisarg; Ryan, Kathy L; Ward, Kevin R; Andre, David; Hurst, Gennifer M; Barrera, Chelsea R; Convertino, Victor A

    2014-03-01

    Due to limited remote triage monitoring capabilities, combat medics cannot currently distinguish bleeding soldiers from those engaged in combat unless they have physical access to them. The purpose of this study was to test the hypothesis that low-level physiological signals can be used to develop a machine-learning algorithm for tracking changes in central blood volume that will subsequently distinguish central hypovolemia from physical activity. Twenty-four subjects underwent central hypovolemia via lower body negative pressure (LBNP), and a supine-cycle exercise protocol. Exercise workloads were determined by matching heart rate responses from each LBNP level. Heart rate and stroke volume (SV) were measured via Finometer. ECG, heat flux, skin temperature, galvanic skin response, and two-axis acceleration were obtained from an armband (SenseWear Pro2) and used to develop a machine-learning algorithm to predict changes in SV as an index of central blood volume under both conditions. The algorithm SV was retrospectively compared against Finometer SV. A model was developed to determine whether unknown data points could be correctly classified into these two conditions using leave-one-out cross-validation. Algorithm vs. Finometer SV values were strongly correlated for LBNP in individual subjects (mean r = 0.92; range 0.75-0.98), but only moderately correlated for exercise (mean r = 0.50; range -0.23-0.87). From the first level of LBNP/exercise, the machine-learning algorithm was able to distinguish between LBNP and exercise with high accuracy, sensitivity, and specificity (all ≥90%). In conclusion, a machine-learning algorithm developed from low-level physiological signals could reliably distinguish central hypovolemia from exercise, indicating that this device could provide battlefield remote triage capabilities. PMID:24408992

  3. Mechanisms of proximal tubule sodium transport regulation that link extracellular fluid volume and blood pressure

    OpenAIRE

    McDonough, Alicia A

    2010-01-01

    One-hundred years ago, Starling articulated the interdependence of renal control of circulating blood volume and effective cardiac performance. During the past 25 years, the molecular mechanisms responsible for the interdependence of blood pressure (BP), extracellular fluid volume (ECFV), the renin-angiotensin system (RAS), and sympathetic nervous system (SNS) have begun to be revealed. These variables all converge on regulation of renal proximal tubule (PT) sodium transport. The PT reabsorbs...

  4. Pulmonary capillary blood volume in patients with probable pulmonary Kaposi's sarcoma.

    OpenAIRE

    Camus, F.; de Picciotto, C.; Gerbe, J; S Roy; Bouchaud, O.; E. Casalino; Perronne, C

    1996-01-01

    BACKGROUND: An increase in pulmonary capillary blood volume secondary to angiogenesis has been described in Kaposi's sarcoma. The value of the pulmonary capillary blood volume as an early marker of pulmonary Kaposi's sarcoma was evaluated. METHODS: In a prospective study 45 HIV positive patients (nine asymptomatic for Kaposi's sarcoma, 29 with cutaneous or mucocutaneous Kaposi's sarcoma, and seven with pulmonary Kaposi's sarcoma), underwent pulmonary function tests and determination of transf...

  5. Loss of alveolar membrane diffusing capacity and pulmonary capillary blood volume in pulmonary arterial hypertension

    OpenAIRE

    Farha Samar; Laskowski Daniel; George Deepa; Park Margaret M; Tang WH Wilson; Dweik Raed A; Erzurum Serpil C

    2013-01-01

    Abstract Background Reduced gas transfer in patients with pulmonary arterial hypertension (PAH) is traditionally attributed to remodeling and progressive loss of pulmonary arterial vasculature that results in decreased capillary blood volume available for gas exchange. Methods We tested this hypothesis by determination of lung diffusing capacity (DL) and its components, the alveolar capillary membrane diffusing capacity (Dm) and lung capillary blood volume (Vc) in 28 individuals with PAH in c...

  6. Cerebral blood volume measured using near-infrared spectroscopy and radiolabels in the immature lamb brain.

    Science.gov (United States)

    Barfield, C P; Yu, V Y; Noma, O; Kukita, J; Cussen, L J; Oates, A; Walker, A M

    1999-07-01

    Near-infrared spectroscopy (NIRS) is a technique that is increasingly being used for the noninvasive measurement of cerebral blood volume (CBV) in newborn infants, but it has not been fully validated against established methods. These experiments in immature lambs (gestation 92+/-1 d, mean+/-SEM) compared CBV measured using NIRS-derived estimates of oxygenated Hb (n = 5) with CBV estimated with radiolabeled indicators (125I-labeled serum albumin and 51Cr-labeled red blood cells, n = 10). Total brain CBV (mL/100 g tissue) measured using NIRS was 2.5+/-0.2 compared with 2.5+/-0.2 using radiolabels (NS). Regional tissue plasma, red blood cells, and whole blood volumes from radiolabels varied significantly (p cerebellum > cortex > brain stem = midbrain > white matter. Regional plasma and red blood cell distributions were similar to whole blood, being highest in choroid plexus (13.0+/-1.6 and 3.2+/-0.9, respectively), and least in white matter (0.8+/-0.1 and 0, respectively). These data from the immature lamb brain indicate that total CBV measured with NIRS is essentially identical with the volumes obtained using intravascular radiolabels. Among cerebral regions, white matter contributes little to the global blood volume measured with NIRS because its red blood cell content is very low. PMID:10400134

  7. Experimental Feasibility Study of Estimation of the Normalized Central Blood Pressure Waveform from Radial Photoplethysmogram

    OpenAIRE

    Sohani, Vahid; Ali, M. A. Mohd.; Chellappan, Kalaivani; Beng, Gan Kok

    2015-01-01

    The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN) from the radial photoplethysmogram (PPG) is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN. A total of fifteen second-order autoregressive models with exogenous input were...

  8. Volume-dependent hemodynamic effects of blood collection in canine donors - evaluation of 13% and 15% of total blood volume depletion

    Directory of Open Access Journals (Sweden)

    RUI R.F. FERREIRA

    2015-03-01

    Full Text Available Background: There is no consensus regarding the blood volume that could be safely donated by dogs, ranging from 11 to 25% of its total blood volume (TBV. No previous studies evaluated sedated donors.Aim: To evaluate the hemodynamic effects of blood collection from sedated and non-sedated dogs and to understand if such effects were volume-dependent.Materials and Methods: Fifty three donations of 13% of TBV and 20 donations of 15% TBV were performed in dogs sedated with diazepam and ketamine. Additionally, a total of 30 collections of 13% TBV and 20 collections of 15% TBV were performed in non-sedated dogs. Non-invasive arterial blood pressures and pulse rates were registered before and 15 min after donation. Results: Post-donation pulse rates increased significantly in both sedated groups, with higher differences in the 15% TBV collections. Systolic arterial pressures decreased significantly in these groups, while diastolic pressures increased significantly in 13% TBV donations. Non-sedated groups revealed a slight, but significant, SBP decrease. No clinical signs related to donations were registered.Conclusion: These results suggest that the collection of 15% TBV in sedated donors induces hemodynamic variations that may compromise the harmlessness of the procedure, while it seems to be a safe procedure in non-sedated dogs.

  9. Central Blood Pressure and Chronic Kidney Disease Progression

    Directory of Open Access Journals (Sweden)

    Debbie L. Cohen

    2011-01-01

    Full Text Available Hypertension, diabetes, and proteinuria are well-recognized risk factors for progressive kidney function loss. However, despite excellent antihypertensive and antidiabetic drug therapies, which also often lower urinary protein excretion, there remains a significant reservoir of patients with chronic kidney disease who are at high risk for progression to end-stage kidney disease. This has led to the search for less traditional cardiovascular risk factors that will help stratify patients at risk for more rapid kidney disease progression. Among these are noninvasive estimates of vascular structure and function. Arterial stiffness, manifested by the pulse wave velocity in the aorta, has been established in a number of studies as a significant risk factor for kidney disease progression and cardiovascular endpoints. Much less well studied in chronic kidney disease are measures of central arterial pressures. In this paper we cover the physiology behind the generation of the central pulse wave contour and the studies available using these approaches and conclude with some speculations on the rationale for why measurements of central pressure may be informative for the study of chronic kidney disease progression.

  10. Central injection of captopril inhibits the blood pressure response to intracerebroventricular choline

    Directory of Open Access Journals (Sweden)

    N. Isbil-Buyukcoskun

    2001-06-01

    Full Text Available In the present study, we investigated the involvement of the brain renin-angiotensin system in the effects of central cholinergic stimulation on blood pressure in conscious, freely moving normotensive rats. In the first step, we determined the effects of intracerebroventricular (icv choline (50, 100 and 150 µg on blood pressure. Choline increased blood pressure in a dose-dependent manner. In order to investigate the effects of brain renin-angiotensin system blockade on blood pressure increase induced by choline (150 µg, icv, an angiotensin-converting enzyme inhibitor, captopril (25 and 50 µg, icv, was administered 3 min before choline. Twenty-five µg captopril did not block the pressor effect of choline, while 50 µg captopril blocked it significantly. Our results suggest that the central renin-angiotensin system may participate in the increase in blood pressure induced by icv choline in normotensive rats.

  11. Measurement of blood flow volume of ocular muscles by Xe-133 clearance method

    International Nuclear Information System (INIS)

    The blood flow volume of the ocular muscles was measured in 8 normal volunteers and 12 cases with miscellaneous opthalmic diseases by Xe-133 clearance method. The average of blood flow volume in the normal subjects was 7.45 ± 2.07 ml/min/100 g, and the blood flow volume ratio of right eye to left eye was 0.94 ± 0.07. The blood flow volume of the ocular muscles was decreased in the cases with stenosis of the internal carotid artery (n = 4, 4.3 ± 2.1 ml/min/100 g), glaucoma (n = 3, 4.7 ± 4.1 ml/min/100 g), arterial scleroses (n = 2, 3.8 ± 0.2 ml/min/100 g) and Takayasu's disease (n = 2, 5.6 ± 0.4 ml/min/100 g), and was increased in the acute inflammatory disease (n = 2, 21.5 ± 2.5 ml/min/100 g). Measurement of the blood flow volume of the ocular muscles using Xe-133 clearance method is useful to evaluate the circulatory abnormality in the ophthalmic diseases. (author)

  12. ANALYSIS OF DISCARD OF WHOLE BLOOD AND BLOOD COMPONENTS IN GOVERNMENT HOSPITAL BLOOD BANK IN CENTRAL INDIA

    OpenAIRE

    Vedita Bobde; Sanjay Parate; Dinkar Kumbhalkar

    2015-01-01

    BACKGROUND: Transfusion requests are always more than the supply due to advances in health care delivery . Injudicious use of whole blood and blood components strains the transfusion services. This mandates the proper analysis of real need of transfusion and the discard of this scarce resource. MATERIALS & METHODS: Total 31143 voluntary and...

  13. Measurement of regional extravascular lung density and of pulmonary blood volume with positron emitting isotopes

    International Nuclear Information System (INIS)

    Studies of pulmonary blood volume changes with exercice can be performed after labelling of the blood pool by 11CO inhalation. Positron transaxial tomography permits the quantitative study of density distribution of the chest and of the pulmonary blood volume. This paper represents our preliminary experience with these techniques on models and control patients. We have first verified the linearity of transmission for density distribution below one. The tomographic examination first records a transmission image, then an emission image on the same section. We next normalize emission and transmission values on a region of unit density corresponding to blood: then we substract the emission from the transmission values to measure the extravascular pulmonary density. With crystal probes we record pulmonary blood volume variations before, during and after exercise. Peripheral hemodynamic variations explain the change recorded at the begining and at the end of exercise. Combination of these two techniques should help us to better study the importance of the acute changes in the ''formation'' of pulmonary oedema and its influence on regional pulmonary blood volume

  14. Solar Central Receiver Prototype Heliostat. Volume I. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    The objective of this project was to support the Solar Central Receiver Power Plant research, development and demonstration effort by: (1) Establishment of a heliostat design, with associated manufacturing, assembly, installation and maintenance approaches, that, in quantity production will yield significant reductions in capital and operating costs over an assumed 30 year plant lifetime as compared with existing designs; and (2) Identification of needs for near term and future research and development in heliostat concept, materials, manufacture, installation, maintenance, and other areas, where successful accomplishment and application would offer significant payoffs in the further reduction of the cost of electrical energy from solar central receiver power plants. The prototype heliostat design is presented in detail; and manufacturing, installation, and maintenance procedures described. (WHK)

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

    Science.gov (United States)

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

    1990-01-01

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

  16. Blood Contrast Agents Enhance Intrinsic Signals in the Retina: Evidence for an Underlying Blood Volume Component

    OpenAIRE

    Schallek, Jesse; Ts'o, Daniel

    2011-01-01

    Systemic injections of blood contrast agents nigrosin and indocyanine green increased stimulus-evoked reflectance signals in the retina. The enhancement of signal strength is consistent with neurovascular coupling in response to visual stimulation.

  17. Exercise induced pulmonary, hepatic and splenic blood volume changes in diabetic subjects

    International Nuclear Information System (INIS)

    Exercise induced blood volume changes in visceral organs were determined by scintillation gamma camera imaging in 11 normal healthy male volunteers and 15 NIDDM male diabetics without clinical signs of neuropathy. After in-vivo labelling of red cells with Technetium-99m, the data was acquired in the supine position at rest and immediately after graded upright ergometer bicycle exercise. From rest to peak exercise, pulmonary blood volume increased 19% and 75% in normal volunteers of less than and more than 40 years of age respectively. A decrease of 18% and 42% was noted in the hepatic and splenic blood volume respectively, regardless of the age, in the normal subjects. In contrast to normals, the diabetic patients showed in response to peak exercise as compared to age-matched controls. A significant difference in the drop in pulmonary blood volume 82.37% and 90% was observed between diabetics of more than and less than 7 years duration respectively. The liver and spleen of the diabetic subjects revealed a lesser decrease of 87.6% and 71.33% respectively in response to peak stress in comparison to the age matched controls. The reduction in the hepatic and splenic blood volume was equally evident in diabetics of more than or less than 50 years of age and it was statistically nonsignificant. This study demonstrates that the normal pattern of redistribution of blood volume in response to maximum exercise in diabetics is altered such that there is restricted pulmonary perfusion and diminished vasoconstriction of the hepato splenic vascular bed and the changes in the pulmonary circulation are related to the duration of the diabetics rather than the age of the patient. (author)

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

    Science.gov (United States)

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

    1990-01-01

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

  19. Lung fractional moving blood volume in normally grown and growth restricted foetuses.

    OpenAIRE

    Hernandez-Andrade, Edgar; Thuring, Ann; Jansson, Tomas; Lingman, Göran; Marsal, Karel

    2004-01-01

    Objective: To examine foetal lung blood perfusion using power Doppler ultrasound (PDU) and to compare fractional moving blood volume (FMBV) and mean pixel intensity (MPI) estimations in the lungs of normally grown (NG) foetuses and foetuses with intrauterine growth restriction (IUGR) and also to correlate foetal lung FMBV and MPI with respiratory complications after birth. Methods: Lungs of 47 NG and 25 IUGR foetuses after 32 weeks of gestation were examined with PDU. FMBV and MPI were...

  20. Casein improves brachial and central aortic diastolic blood pressure in overweight adolescents: a randomised, controlled trial

    DEFF Research Database (Denmark)

    Arnberg, Karina; Larnkjær, Anni; Michaelsen, Kim F.;

    2013-01-01

    Arterial stiffness, blood pressure (BP) and blood lipids may be improved by milk in adults and the effects may be mediated via proteins. However, limited is known about the effects of milk proteins on central aortic BP and no studies have examined the effects in children. Therefore, the present...... stiffness or blood lipid concentrations. A high intake of casein improves DBP in overweight adolescents. Thus, casein may be beneficial for younger overweight subjects in terms of reducing the longterm risk of CVD. In contrast, whey protein seems to increase BP compared with drinking water; however, water...... trial examined the effect of milk and milk proteins on brachial and central aortic BP, blood lipids, inflammation and arterial stiffness in overweight adolescents. A randomised controlled trial was conducted in 193 overweight adolescents aged 12–15 years. They were randomly assigned to drink 1 litre of...

  1. Influence of passive stretch on muscle blood flow, oxygenation and central cardiovascular responses in healthy young males.

    Science.gov (United States)

    Kruse, Nicholas T; Silette, Christopher R; Scheuermann, Barry W

    2016-05-01

    The aim of this study was to examine the effect of skeletal muscle stretching on peripheral, central, and autonomic cardiovascular responses in humans. Twelve healthy males completed a controlled passive stretch of the plantar flexors for 4 min at three different intensities. Doppler ultrasound velocimetry and imaging techniques assessed mean leg blood flow (MLBF), antegrade blood flow, and retrograde blood flow of the popliteal artery. Near-infrared spectroscopy assessed the concentration of deoxygenated hemoglobin + myoglobin ([HHb]) and the sum of its deoxygenated and oxygenated forms [i.e., blood volume ([Hbtot])]. Heart rate (HR) and mean arterial pressure were measured simultaneously to peripheral hemodynamic responses. During stretch there was an increase (P < 0.05) in antegrade and retrograde blood flow along with [HHb] and [Hbtot] relative to baseline, whereas MLBF was not altered. HR increased (P < 0.01) in a stretch intensity- and time-dependent manner, suggesting a threshold tension must be met that results in a mechanoreflex-mediated increase in HR. After stretch there was an increase (P < 0.05) in [Hbtot] and MLBF in each condition, suggesting that stretch creates a poststretch hyperemic response. Furthermore, retrograde blood flow was decreased (P < 0.05) after stretch in each stretch condition. Mean arterial pressure was decreased (P < 0.05) after moderate-intensity stretching. Collectively, our data provide novel mechanistic evidence on cardiovascular responses to skeletal muscle stretching in humans. Moreover, the reductions in MAP and retrograde blood flow suggest that stretch transiently reduces myogenic vascular tone in a poststretch resting period. PMID:26945077

  2. Blood volume determination with two radioisotopes: application to non-cardiogenic shock

    International Nuclear Information System (INIS)

    Knowledge of the circulating blood volume may be of great assistance in the study of clinical shock. The isotope dilution principle is used to measure both plasma and red cell volume. Considering the increased capillary permeability in patients in shock, it may be of considerable value to quantify the diffusion of liquid through the capillary walls. A double determination of the volume of distribution of the tracer is to be envisaged. Two methods are described. The first one uses a non-diffusible tracer (sup(99m)Tc-labelled red cells) confined to the intravascular space, giving a measure of the intravascular blood volume. The latter uses 131I-labelled serum albumin which remains, usually, in the vascular bed, but is able to diffuse through the pores of the capillary membrane, because of its low molecular weight. A resulting increase of the tracer volume distribution, with regard to this capillary diffusion is considered. A comparison of the two methods used simultaneously appear to provide information on the possible liquid diffusion in clinical shock. The results obtained in several pathological conditions are described. They enable conclusion to be drawn on the possibility of errors introduced by the use of 131I-labelled serum albumin alone in determining the circulating blood volume in clinical shock

  3. Effect of pertussis toxin pretreated centrally on blood glucose level induced by stress.

    Science.gov (United States)

    Suh, Hong-Won; Sim, Yun-Beom; Park, Soo-Hyun; Sharma, Naveen; Im, Hyun-Ju; Hong, Jae-Seung

    2016-09-01

    In the present study, we examined the effect of pertussis toxin (PTX) administered centrally in a variety of stress-induced blood glucose level. Mice were exposed to stress after the pretreatment of PTX (0.05 or 0.1 µg) i.c.v. or i.t. once for 6 days. Blood glucose level was measured at 0, 30, 60 and 120 min after stress stimulation. The blood glucose level was increased in all stress groups. The blood glucose level reached at maximum level after 30 min of stress stimulation and returned to a normal level after 2 h of stress stimulation in restraint stress, physical, and emotional stress groups. The blood glucose level induced by cold-water swimming stress was gradually increased up to 1 h and returned to the normal level. The intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX, a Gi inhibitor, alone produced a hypoglycemia and almost abolished the elevation of the blood level induced by stress stimulation. The central pretreatment with PTX caused a reduction of plasma insulin level, whereas plasma corticosterone level was further up-regulated in all stress models. Our results suggest that the hyperglycemia produced by physical stress, emotional stress, restraint stress, and the cold-water swimming stress appear to be mediated by activation of centrally located PTX-sensitive G proteins. The reduction of blood glucose level by PTX appears to due to the reduction of plasma insulin level. The reduction of blood glucose level by PTX was accompanied by the reduction of plasma insulin level. Plasma corticosterone level up-regulation by PTX in stress models may be due to a blood glucose homeostatic mechanism. PMID:27610033

  4. Altitude acclimatization and blood volume: effects of exogenous erythrocyte volume expansion

    DEFF Research Database (Denmark)

    Sawka, M N; Young, Jette Feveile; Rock, P B;

    1996-01-01

    blood oxygen content alters erythropoietin responses during altitude acclimatization, and 4) mechanisms responsible for plasma loss at altitude. Sixteen healthy men had a series of hematologic measurements made at sea level, on the first and ninth days of altitude (4,300 m) residence, and after...

  5. North Central Regional geologic characterization report. Volume 1. Final report

    International Nuclear Information System (INIS)

    This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geologic factor and variables include deep mines and quarries, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, groundwater resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies. A discussion is also presented of the relationship between the US Department of Energy Siting Guidelines (10 CFR 960) and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process. 43 figs., 15 tabs

  6. Revised draft: North Central Regional geologic characterization report. Volume 1

    International Nuclear Information System (INIS)

    This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the disqualifying factor and the screening variables to be used in region-to-area screening. These factors and variables include hydrologically significant natural resources, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, water resources, groundwater salinity, and state of stress. Information is presented on age, areal extent, shape, thickness of overburden, composition, texture, degree and type of alteration, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the subject rock bodies. A discussion of the relationship between the DOE Siting Guidelines and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process is also presented

  7. Revised draft: North Central Regional environmental characterization report. Volume 1

    International Nuclear Information System (INIS)

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed federal protected lands, proximity to federal protected lands, existing state protected lands, proximity to state protected lands, population density and distribution, proximity to highly populated areas, national and state forest lands, state wildlife lands, designated critical habitats for threatened and endangered species, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that may be of use at later phases of screening. Also included is a discussion of the relationship between the DOE Siting Guidelines and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  8. North Central Regional environmental characterization report. Volume 1. Final report

    International Nuclear Information System (INIS)

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed Federal-protected lands, proximity to Federal-protected lands, components of national forest lands, existing state-protected lands, proximity to state-protected lands, population density and distribution, proximity to highly populated areas or to 1-mile square areas with 1000 or more persons, national and state forest lands, designated critical habitats for threatened and endangered spcies, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that will be of use at later phases of screening. Also included is a discussion of the relationship between the US Department of Energy Siting Guidelines (10CFR 960) and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  9. Heat pipe central solar receiver. Volume I. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, W. B.; Wolf, D. A.

    1979-04-01

    The objective of this project was the conceptual design of a Central Solar Receiver Gas Turbine Plant which utilizes a high temperature heat pipe receiver. Technical and economic feasibility of such a plant was to be determined and preliminary overall cost estimates obtained. The second objective was the development of the necessary heat pipe technology to meet the requirements of this receiver. A heat pipe receiver is ideally suited for heating gases to high temperatures. The heat pipes are essentially loss free thermal diffusers which accept a high solar flux and transform it to a lower flux which is compatible with heat transferred to gases. The high flux capability reduces receiver heating surface, thereby reducing receiver heat losses. An open recuperative air cycle with a turbine inlet temperature of 816/sup 0/C (1500/sup 0/F) was chosen as the baseline design. This results in peak metal temperatures of about 870/sup 0/C (1600/sup 0/F). The receiver consists of nine modular panels which form the semicircular backwall of a cavity. Gas enters the panels at the bottom and exits from the top. Each panel carries 637 liquid metal heat pipes which are mounted at right angle to the gas flow. The evaporators of the heat pipes protrude from the flux absorbing front surface of the panels, and the finned condensors traverse the gas stream. Capital cost estimates were made for a 10 MW(e) pilot plant. The total projected costs, in mid-1978 dollars, range from $1,947 to $2,002 per electrical kilowatt. On the same basis, the cost of a water/steam solar plant is approximately 50% higher.

  10. Acute attenuation of glycocalyx barrier properties increases coronary blood volume independently of coronary flow reserve

    NARCIS (Netherlands)

    J. Brands; J.A.E. Spaan; B.M. van den Berg; H. Vink; J.W.G.E. VanTeeffelen

    2010-01-01

    Brands J, Spaan JA, Van den Berg BM, Vink H, VanTeeffelen JW. Acute attenuation of glycocalyx barrier properties increases coronary blood volume independently of coronary flow reserve. Am J Physiol Heart Circ Physiol 298: H515-H523, 2010. First published November 25, 2009; doi:10.1152/ajpheart.01306

  11. Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B; Garde, K; Ring, P B; Henriksen, O

    1996-01-01

    PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...

  12. Central Gi(2) proteins, sympathetic nervous system and blood pressure regulation

    Czech Academy of Sciences Publication Activity Database

    Zicha, Josef

    2016-01-01

    Roč. 216, č. 3 (2016), s. 258-259. ISSN 1748-1708 Institutional support: RVO:67985823 Keywords : inhibitory G proteins * sympathetic nervous system * central blood pressure control Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.382, year: 2014

  13. Functional photoacoustic tomography for non-invasive imaging of cerebral blood oxygenation and blood volume in rat brain in vivo

    Science.gov (United States)

    Wang, Xueding; Xie, Xueyi; Ku, Geng; Stoica, George; Wang, Lihong V.

    2005-04-01

    Based on the multi-wavelength laser-based photoacoustic tomography, non-invasive in vivo imaging of functional parameters, including the hemoglobin oxygen saturation and the total concentration of hemoglobin, in small-animal brains was realized. The high sensitivity of this technique is based on the spectroscopic differences between oxy- and deoxy-hemoglobin while its spatial resolution is bandwidth-limited by the photoacoustic signals rather than by the optical diffusion as in optical imaging. The point-by-point distributions of blood oxygenation and blood volume in the cerebral cortical venous vessels, altered by systemic physiological modulations including hyperoxia, normoxia and hypoxia, were visualized successfully through the intact skin and skull. This technique, with its prominent intrinsic advantages, can potentially accelerate the progress in neuroscience and provide important new insights into cerebrovascular physiology and brain function that are of great significance to the neuroscience community.

  14. Determination of cardiac output, tissue blood flow, volume and lipid content in Sprague-Dawley rats

    International Nuclear Information System (INIS)

    One critical aspect of physiologically-based pharmacokinetic (PBPK) model development is the choice of values for organ blood flows, cardiac output and tissue volumes for input into models. These values vary depending upon the strain, size, age, and sex of animal for which a PBPK model is being developed. Tissue blood flows, cardiac output, tissue volume, and lipid content were determined in male S-D rats, (350-375 g, N=8). A radiolabel microsphere method utilizing Scandium (46Sc), Tin (113Sn),and Gadolinium (153Gd) was used to determine blood flow. Each rat received 3 radiolabeled injections. After the third injection, animals were sacrificed, and radioactivity in each tissue was determined in a 3-channel gamma counter. Tissues sampled include brain, heart, kidneys, liver, lungs, spleen, pancreas, adrenals, stomach, intestines, colon, testis, bone and skeletal muscle. Cardiac output was 142 ml/min. Blood flow values for eliminating organs were 0.49 (liver), 16.52 (kidney), and 1.77 (lung) ml/min/g tissue. Tissues which had significantly increased blood flow during the dark cycle included femur, abdonimal fat, triceps brachii and abdominal muscles, stomach, spleen and lung. Dissectable fat, organ volume, and organ lipid content were determined in a separate group of rats (N= 8). Volume and lipid content were determined for the same tissues as blood flow. Body fat was 7.35% of bw and extractable lipid content of eliminating organs was 42.3 (liver), 43.4 (kidney), and 35.9 (lung) mg/g tissue. Precise measurements should improve the accuracy of PBPK model predictions, and therfore help in reducing uncertainites in risk assessment of volatile organics and other pollutnats

  15. Absolute cerebral blood flow and blood volume measured by magnetic resonance imaging bolus tracking: comparison with positron emission tomography values

    DEFF Research Database (Denmark)

    Østergaard, Leif; Smith, D F; Vestergaard-Poulsen, Peter;

    1998-01-01

    blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small...... hypercapnic conditions. After dose normalization and introduction of an empirical constant phi Gd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral...

  16. Central blood pressure assessment using 24-hour brachial pulse wave analysis

    Directory of Open Access Journals (Sweden)

    Muiesan ML

    2014-10-01

    Full Text Available Maria Lorenza Muiesan, Massimo Salvetti, Fabio Bertacchini, Claudia Agabiti-Rosei, Giulia Maruelli, Efrem Colonetti, Anna Paini Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy Abstract: This review describes the use of central blood pressure (BP measurements during ambulatory monitoring, using noninvasive devices. The principles of measuring central BP by applanation tonometry and by oscillometry are reported, and information on device validation studies is described. The pathophysiological basis for the differences between brachial and aortic pressure is discussed. The currently available methods for central aortic pressure measurement are relatively accurate, and their use has important clinical implications, such as improving diagnostic and prognostic stratification of hypertension and providing a more accurate assessment of the effect of treatment on BP. Keywords: aortic blood pressure measurements, ambulatory monitoring, pulse wave analysis

  17. Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

    Science.gov (United States)

    Baum, K.; Essfeld, D.; Stegemann, J.

    To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

  18. The measurement of peripheral blood volume reactions to tilt test by the electrical impedance technique after exercise in athletes

    International Nuclear Information System (INIS)

    We have investigated the distribution of peripheral blood volumes in different regions of the body in response to the tilt-test in endurance trained athletes after aerobic exercise. Distribution of peripheral blood volumes (ml/beat) simultaneously in six regions of the body (two legs, two hands, abdomen, neck and ECG) was assessed in response to the tilt-test using the impedance method (the impedance change rate (dZ/dT). Before and after exercise session cardiac stroke (CSV) and blood volumes in legs, arms and neck were higher in athletes both in lying and standing positions. Before exercise the increase of heart rate and the decrease of a neck blood volume in response to tilting was lower (p <0.05) but the decrease of leg blood volumes was higher (p<0.001) in athletes. The reactions in arms and abdomen blood volumes were similar. Also, the neck blood volumes as percentage of CSV (%/CSV) did not change in the control but increased in athletes (p <0.05) in response to the tilt test. After (10 min recovery) the aerobic bicycle exercise (mean HR = 156±8 beat/min, duration 30 min) blood volumes in neck and arms in response to the tilting were reduced equally, but abdomen (p<0.05) and leg blood volumes (p <0.001) were lowered more significantly in athletes. The neck blood flow (%/CSV) did not change in athletes but decreased in control (p<0.01), which was offset by higher tachycardia in response to tilt-test in controls after exercise. The data demonstrate greater orthostatic tolerance in athletes both before and after exercise during fatigue which is due to effective distribution of blood flows aimed at maintaining cerebral blood flow.

  19. Smart fast blood counting of trace volumes of body fluids from various mammalian species using a compact custom-built microscope cytometer (Conference Presentation)

    Science.gov (United States)

    Smith, Zachary J.; Gao, Tingjuan; Lin, Tzu-Yin; Carrade-Holt, Danielle; Lane, Stephen M.; Matthews, Dennis L.; Dwyre, Denis M.; Wachsmann-Hogiu, Sebastian

    2016-03-01

    Cell counting in human body fluids such as blood, urine, and CSF is a critical step in the diagnostic process for many diseases. Current automated methods for cell counting are based on flow cytometry systems. However, these automated methods are bulky, costly, require significant user expertise, and are not well suited to counting cells in fluids other than blood. Therefore, their use is limited to large central laboratories that process enough volume of blood to recoup the significant capital investment these instruments require. We present in this talk a combination of a (1) low-cost microscope system, (2) simple sample preparation method, and (3) fully automated analysis designed for providing cell counts in blood and body fluids. We show results on both humans and companion and farm animals, showing that accurate red cell, white cell, and platelet counts, as well as hemoglobin concentration, can be accurately obtained in blood, as well as a 3-part white cell differential in human samples. We can also accurately count red and white cells in body fluids with a limit of detection ~3 orders of magnitude smaller than current automated instruments. This method uses less than 1 microliter of blood, and less than 5 microliters of body fluids to make its measurements, making it highly compatible with finger-stick style collections, as well as appropriate for small animals such as laboratory mice where larger volume blood collections are dangerous to the animal's health.

  20. Daily Liquorice Consumption for Two Weeks Increases Augmentation Index and Central Systolic and Diastolic Blood Pressure

    Science.gov (United States)

    Leskinen, Miia H.; Hautaniemi, Elina J.; Tahvanainen, Anna M.; Koskela, Jenni K.; Päällysaho, Marika; Tikkakoski, Antti J.; Kähönen, Mika; Kööbi, Tiit; Niemelä, Onni; Mustonen, Jukka; Pörsti, Ilkka H.

    2014-01-01

    Background Liquorice ingestion often elevates blood pressure, but the detailed haemodynamic alterations are unknown. We studied haemodynamic changes induced by liquorice consumption in 20 subjects versus 30 controls with average blood pressures of 120/68 and 116/64 mmHg, respectively. Methods Haemodynamic variables were measured in supine position before and after two weeks of liquorice consumption (daily glycyrrhizin dose 290–370 mg) with tonometric recording of radial blood pressure, pulse wave analysis, and whole-body impedance cardiography. Thirty age-matched healthy subjects maintaining their normal diet were studied as controls. Results Two weeks of liquorice ingestion elevated peripheral and central systolic and diastolic blood pressure (by 7/4 and 8/4 mmHg, 95% confidence intervals [CI] 2-11/1-8 and 3-13/1-8, respectively, P ClinicalTrials.gov NCT01742702 PMID:25153328

  1. Analytical method of PBDES and PCBS from small volume human blood

    Energy Technology Data Exchange (ETDEWEB)

    Fujimine, Y.; Koizumi, A. [Kyoto Univ. (Japan); Mochizuki, A.; Hirai, T. [Otsuka Pharmaceutical, Tokushima (Japan)

    2004-09-15

    In order to conduct the epidemiological survey for children and old peoples, it is necessary to develop/improve the analytical method with which to conduct the analysis in smaller volume of blood samples because the blood volume from these subjects are normally allowed to take less than 5mL. For these purposes, we developed the Small Volume method (SV-method) using HRGC/HRMS for the PCBs and PBDEs analysis. The SV method for PCB can start the analysis only with 1.0 mL of whole blood and that for PBDE with 1.5 mL of whole blood, respectively; these methods showed the ultra high sensitivity. However the SV-method can not determine all isomer of PCBs and PBDEs but only predominant isomers of those chemicals. In the Healthy volunteers examination, the SV-PCB determined 13 isomers and the SV-PBDE method determined 4 isomers, respectively. By the way, SV-PCB and SV-PBDE method determined almost all levels in the sample; SV-PCB is 75% as compared with sum of all PCB isomers level, SV-PBDE is 82% as compared with sum of all PBDE isomers level. In summary, SV-method using HRGC/HRMS can determine approximate and predominant isomers levels of PCBs and PBDEs, making it possible to evaluate the human exposure to these chemicals. In this paper, the method of SV-PCB and SV-PBDE were described with precision date.

  2. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    International Nuclear Information System (INIS)

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  3. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    International Nuclear Information System (INIS)

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (vp) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. vp and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between vp and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  4. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Artzi, Moran [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Liberman, Gilad; Vitinshtein, Faina; Aizenstein, Orna [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Nadav, Guy [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Faculty of Engineering, Tel Aviv (Israel); Blumenthal, Deborah T.; Bokstein, Felix [Tel Aviv Sourasky Medical Center, Neuro-Oncology Service, Tel Aviv (Israel); Bashat, Dafna Ben [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv (Israel)

    2015-07-15

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (v{sub p}) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. v{sub p} and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between v{sub p} and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  5. Doppler sonography of diabetic feet: Quantitative analysis of blood flow volume

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Lan; Kim, Ho Chul; Choi, Chul Soon; Yoon, Dae Young; Han, Dae Hee; Moon, Jeung Hee; Bae, Sang Hoon [Hallym University College of Medicine, Seoul (Korea, Republic of)

    2002-09-15

    To analyze Doppler sonographic findings of diabetic feet by estimating the quantitative blood flow volume and by analyzing waveform on Doppler. Doppler sonography was performed in thirty four patients (10 diabetic patients with foot ulceration, 14 diabetic patients without ulceration and 10 normal patients as the normal control group) to measure the flow volume of the arteries of the lower extremities (posterior and anterior tibial arteries, and distal femoral artery. Analysis of doppler waveforms was also done to evaluate the nature of the changed blood flow volume of diabetic patients, and the waveforms were classified into triphasic, biphasic-1, biphasic-2 and monophasic patterns. Flow volume of arteries in diabetic patients with foot ulceration was increased witha statistical significance when compared to that of diabetes patients without foot ulceration of that of normal control group (P<0.05). Analysis of Doppler waveform revealed that the frequency of biphasic-2 pattern was significantly higher in diabetic patients than in normal control group(p<0.05). Doppler sonography in diabetic feet showed increased flow volume and biphasic Doppler waveform, and these findings suggest neuropathy rather than ischemic changes in diabetic feet.

  6. Patient-specific coronary artery blood flow simulation using myocardial volume partitioning

    Science.gov (United States)

    Kim, Kyung Hwan; Kang, Dongwoo; Kang, Nahyup; Kim, Ji-Yeon; Lee, Hyong-Euk; Kim, James D. K.

    2013-03-01

    Using computational simulation, we can analyze cardiovascular disease in non-invasive and quantitative manners. More specifically, computational modeling and simulation technology has enabled us to analyze functional aspect such as blood flow, as well as anatomical aspect such as stenosis, from medical images without invasive measurements. Note that the simplest ways to perform blood flow simulation is to apply patient-specific coronary anatomy with other average-valued properties; in this case, however, such conditions cannot fully reflect accurate physiological properties of patients. To resolve this limitation, we present a new patient-specific coronary blood flow simulation method by myocardial volume partitioning considering artery/myocardium structural correspondence. We focus on that blood supply is closely related to the mass of each myocardial segment corresponding to the artery. Therefore, we applied this concept for setting-up simulation conditions in the way to consider many patient-specific features as possible from medical image: First, we segmented coronary arteries and myocardium separately from cardiac CT; then the myocardium is partitioned into multiple regions based on coronary vasculature. The myocardial mass and required blood mass for each artery are estimated by converting myocardial volume fraction. Finally, the required blood mass is used as boundary conditions for each artery outlet, with given average aortic blood flow rate and pressure. To show effectiveness of the proposed method, fractional flow reserve (FFR) by simulation using CT image has been compared with invasive FFR measurement of real patient data, and as a result, 77% of accuracy has been obtained.

  7. Age dependency of central and peripheral systolic blood pressures: Cross-sectional and longitudinal observations in European populations

    OpenAIRE

    Wojciechowska, Wiktoria; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Richart, Tom; Seidlerová, Jitka; Cwynar, Marcin; Thijs, Lutgarde; Li, Yan; Kuznetsova, Tatiana; Filipovský, Jan; Casiglia, Edoardo; Grodzicki, Tomasz; Kawecka-Jaszcz, Kalina; O'Rourke, Michael; Staessen, Jan A.

    2012-01-01

    Abstract Background. As arteries become stiffer with ageing, reflected waves move faster and augment late systolic pressure. We investigated the age dependency of peripheral and central systolic pressure, pressure amplification (peripheral systolic blood pressure - central systolic blood pressure), and peripheral and central systolic augmentation (maximal systolic pressure minus the first peak of the pressure wave). Methods. We randomly recruited 1420 White Europeans (mean age, 41.7 years). p...

  8. Pulmonary diffusing capacity, capillary blood volume, and cardiac output during sustained microgravity

    Science.gov (United States)

    Prisk, G. K.; Guy, Harold J. B.; Elliott, Ann R.; Deutschman, Robert A., III; West, John B.

    1993-01-01

    We measured pulmonary diffusing capacity (DL), diffusing capacity per unit lung volume, pulmonary capillary blood volume (Vc), membrane diffusing capacity (Dm), pulmonary capillary blood flow or cardiac output (Qc), and cardiac stroke volume (SV) in four subjects exposed to nine days of microgravity. DL in microgravity was elevated compared with preflight standing values and was higher than preflight supine because of the elevation of both Vc and Dm. The elevation in Vc was comparable to that measured supine in 1 G, but the increase in Dm was in sharp contrast to the supine value. We postulate that, in 0 G, pulmonary capillary blood is evenly distributed throughout the lung, providing for uniform capillary filling, leading to an increase in the surface area available for diffusion. By contrast, in the supine 1-G state, the capillaries are less evenly filled, and although a similar increase in blood volume is observed, the corresponding increase in surface area does not occur. DL and its subdivisions showed no adaptive changes from the first measurement 24 h after the start of 0 G to eight days later. Similarly, there were no trends in the postflight data, suggesting that the principal mechanism of these changes was gravitational. The increase in Dm suggests that subclinical pulmonary edema did not result from exposure to 0 G. Qc was modestly increased inflight and decreased postflight compared with preflight standing. Compared with preflight standing, SV was increased 46 percent inflight and decreased 14 percent in the 1st week postflight. There were temporal changes in Qc and SV during 0 G, with the highest values recorded at the first measurement, 24 h into the flight. The lowest values of Qc and SV occurred on the day of return.

  9. Reduction of pulmonary capillary blood volume in patients with severe unexplained pulmonary hypertension.

    OpenAIRE

    Borland, C.; Cox, Y.; Higenbottam, T

    1996-01-01

    BACKGROUND: Unexplained or primary pulmonary hypertension results in an obliteration and obstruction of resistance pulmonary arteries. In these patients gas exchange is impaired and the measurement of gas transfer for carbon monoxide is usually reduced. This has been thought to represent a reduction in pulmonary alveolar capillary blood volume (Vc). A single breath test, measuring simultaneously the uptake of both nitric oxide (NO) and carbon monoxide (CO), provides a simple and practical mea...

  10. Assessing Pulmonary Perfusion in Emphysema Automated Quantification of Perfused Blood Volume in Dual-Energy CTPA

    OpenAIRE

    Meinel, Felix G.; Graef, Anita; Thieme, Sven F.; Bamberg, Fabian; Schwarz, Florian; Sommer, Wieland; Helck, Andreas D.; Neurohr, Claus; Reiser, Maximilian F.; Johnson, Thorsten R. C.

    2013-01-01

    Objectives: The objective of this study was to determine whether automated quantification of lung perfused blood volume (PBV) in dual-energy computed tomographic pulmonary angiography (DE-CTPA) can be used to assess the severity and regional distribution of pulmonary hypoperfusion in emphysema. Materials and Methods: We retrospectively analyzed 40 consecutive patients (mean age, 67 13] years) with pulmonary emphysema, who have no cardiopulmonary comorbidities, and a DE-CTPA negative for pulmo...

  11. Immunity to diphtheria and tetanus among blood donors in Arak, central province of Iran.

    OpenAIRE

    Ali Eslamifar; Amitis Ramezani; Mohammad Banifazl; Masoomeh Sofian; Fatemeh-Alsadat Mahdaviani; Farhad Yaghmaie; Arezoo Aghakhani

    2014-01-01

    Background and Objectives Tetanus and diphtheria are vaccine-preventable, infectious diseases with significant morbidity and mortality. Immunization by the diphtheria and tetanus toxoid (DT) has been applied in Iran for almost 50 years. However, there are very few data about the rate of immunity to these diseases in the adult population. the humoral immunity to tetanus and diphtheria among blood donors in Arak city, central provice of Iran were investigated. Patients & Methods A total of 530 ...

  12. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill;

    2009-01-01

    Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...

  13. Experimental feasibility study of estimation of the normalized central blood pressure waveform from radial photoplethysmogram.

    Science.gov (United States)

    Zahedi, Edmond; Sohani, Vahid; Ali, M A Mohd; Chellappan, Kalaivani; Beng, Gan Kok

    2015-01-01

    The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN) from the radial photoplethysmogram (PPG) is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN. A total of fifteen second-order autoregressive models with exogenous input were investigated using system identification techniques. Among these 15 models, the model producing the lowest coefficient of variation (CV) of the fitness during the five days was selected as the reference model. Results show that the proposed model is able to faithfully reproduce CBPN (mean fitness = 85.2% ± 2.5%) from the radial PPG for all 15 segments during the five recording days. The low CV value of 3.35% suggests a stable model valid for different recording days. PMID:25708380

  14. Experimental Feasibility Study of Estimation of the Normalized Central Blood Pressure Waveform from Radial Photoplethysmogram

    Directory of Open Access Journals (Sweden)

    Edmond Zahedi

    2015-01-01

    Full Text Available The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN from the radial photoplethysmogram (PPG is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN. A total of fifteen second-order autoregressive models with exogenous input were investigated using system identification techniques. Among these 15 models, the model producing the lowest coefficient of variation (CV of the fitness during the five days was selected as the reference model. Results show that the proposed model is able to faithfully reproduce CBPN (mean fitness = 85.2% ± 2.5% from the radial PPG for all 15 segments during the five recording days. The low CV value of 3.35% suggests a stable model valid for different recording days.

  15. Central and peripheral blood pressures in relation to plasma advanced glycation end products in a Chinese population.

    Science.gov (United States)

    Huang, Q-F; Sheng, C-S; Kang, Y-Y; Zhang, L; Wang, S; Li, F-K; Cheng, Y-B; Guo, Q-H; Li, Y; Wang, J-G

    2016-07-01

    We investigated the association of plasma AGE (advanced glycation end product) concentration with central and peripheral blood pressures and central-to-brachial blood pressure amplification in a Chinese population. The study subjects were from a newly established residential area in the suburb of Shanghai. Using the SphygmoCor system, we recorded radial arterial waveforms and derived aortic waveforms by a generalized transfer function and central systolic and pulse pressure by calibration for brachial blood pressure measured with an oscillometric device. The central-to-brachial pressure amplification was expressed as the central-to-brachial systolic blood pressure difference and pulse pressure difference and ratio. Plasma AGE concentration was measured by the enzyme-linked immunosorbent assay method and logarithmically transformed for statistical analysis. The 1051 participants (age, 55.1±13.1 years) included 663 women. After adjustment for sex, age and other confounding factors, plasma AGE concentration was associated with central but not peripheral blood pressures and with some of the pressure amplification indexes. Indeed, each 10-fold increase in plasma AGE concentration was associated with 2.94 mm Hg (P=0.04) higher central systolic blood pressure and 2.39% lower central-to-brachial pulse pressure ratio (P=0.03). In further subgroup analyses, the association was more prominent in the presence of hypercholesterolemia (+8.11 mm Hg, P=0.008) for central systolic blood pressure and in the presence of overweight and obesity (-4.89%, P=0.009), diabetes and prediabetes (-6.26%, P=0.10) or current smoking (-6.68%, P=0.045) for central-to-brachial pulse pressure ratio. In conclusion, plasma AGE concentration is independently associated with central systolic blood pressure and pulse pressure amplification, especially in the presence of several modifiable cardiovascular risk factors. PMID:26084655

  16. Minimal volume regulation after shrinkage of red blood cells from five species of reptiles

    DEFF Research Database (Denmark)

    Kristensen, Karina; Berenbrink, Michael; Koldkjær, Pia;

    2008-01-01

    Red blood cells (RBCs) from most vertebrates restore volume upon hypertonic shrinkage and the mechanisms underlying this regulatory volume increase (RVI) have been studied extensively in these cells. Despite the phylogenetically interesting position of reptiles, very little is known about their red...... cell function. The present study demonstrates that oxygenated RBCs in all major groups of reptiles exhibit no or a very reduced RVI upon ~ 25% calculated hyperosmotic shrinkage. Thus, RBCs from the snakes Crotalus durissus and Python regius, the turtle Trachemys scripta and the alligator Alligator...... mississippiensis showed no statistically significant RVI within 120 min after shrinkage, while the lizard Tupinambis merianae showed 22% volume recovery after 120 min. Amiloride (10- 4 M) and bumetanide (10- 5 M) had no effect on the RVI in T. merianae, indicating no involvement of the Na+/H+ exchanger (NHE) or...

  17. Age-related changes in regional cerebral blood flow and brain volume in healthy subjects

    International Nuclear Information System (INIS)

    Using the xenon-133 inhalation method, we studied the age-related decline in regional cerebral blood flow, calculated as the initial slope index (ISI), in neurologically normal subjects without any risk factors for cerebral arteriosclerosis (154 men and 123 women), ranging in age from 19 to 88 years. The decline in the ISI was rapid in younger age groups and gradual in older age groups. The ISI was higher in women than in men older than 40 years. Using computed tomography, we studied the age-related decline in brain volume index (BVI; 100% X brain volume/cranial cavity volume) in neurologically normal subjects without any risk factors for cerebral arteriosclerosis (92 men and 49 women), ranging in age from 37 to 86 years. The decline in the BVI was gradual in younger age groups and rapid in older age groups. The BVI was higher in women than in men older than 60 years

  18. THE CENTRAL DISTRIBUTION OF ADRENOMEDULLIN AND ITS EFFECTS ON BLOOD PRESSURE AND HEART RATE IN RATS

    Institute of Scientific and Technical Information of China (English)

    魏英杰; 李倩虹; 宋良文; 赵东; 张肇康; 何瑞荣; 汤健

    1996-01-01

    The present study was designed to make certairt whether there exists adrenomedullinrat central nervous system and evaluated the hemodynamic actions of in(ADM) in the administration(ICVA) of human ADM[13-52]. By immunobistochemistry (ABC method), We tound that there was a discrete localization of ADM positive immunoreactivity in the rat central system including cerebral cortex,paravent ricular tissues, hypothalamus, cerehellla cortex, mesencephalon and medulla oblongata. By reverse transcription polymerase chain reaction (RT-PCR) analysis, rat ADM mRNA was found to be expressed in rat brain. These above results of irnmunohistochemistry and RT PCR suggest that ADM exists in the rat brain. We also found that centrally administered ADM[13-52 in a dose of 0. 4 to 3.2 nmol/kg provoked marked, prolonged and dosedeioeudent increases in mean arteriBl blood pressure (MABP) and heart rate(HR). To clarify the mechanisms of the bemudynamic changes induced by centrally administered ADM[13-52], the effect of centrally administered ADM[13-52] on renal sympathetic nerve activity(RSNA)was studied, The result showed that centrally admiaaistered ADM [13-52] (1. 6 nmol/kg) provoked a marked increase in RSNA, therefore, the increases in MABP and HR induced by centrally administered ADM[13-52]might he due to the stimulation of central sympathetic mechanism. In eddtion,we also compared the relationship of activity and structure among the different fragments of ADM. In conclusion,ADM exists in the rat brain,and it may play an important role in the central control of cardiovascular system.

  19. Study of the spatial distribution of the absorbed dose in blood volumes irradiated using a teletherapy unit

    International Nuclear Information System (INIS)

    Blood irradiation can be performed using a dedicated blood irradiator or a teletherapy unit. A thermal device providing appropriate storage conditions during blood components irradiation with a teletherapy unit has been recently proposed. However, the most appropriated volume of the thermal device was not indicated. The goal of this study was to indicate the most appropriated blood volume for irradiation using a teletherapy unit in order to minimize both the dose heterogeneity in the volume and the blood irradiation time using these equipments. Theoretical and experimental methods were used to study the dose distribution in the blood volume irradiated using a linear accelerator and a cobalt-60 therapy machine. The calculation of absorbed doses in the middle plane of cylindrical acrylic volumes was accomplished by a treatment planning system. Experimentally, we also used cylindrical acrylic phantoms and thermoluminescent dosimeters to confirm the calculated doses. The data obtained were represented by isodose curves. We observed that an irradiation volume should have a height of 28 cm and a diameter of 28 cm and a height of 35 cm and a diameter of 35 cm, when the irradiation is to be performed by a linear accelerator and a cobalt-60 teletherapy unit, respectively. Calculated values of relative doses varied from 93% to 100% in the smaller volume, and from 66% to 100% in the largest one. A difference of 5.0%, approximately, was observed between calculated and experimental data. The size of these volumes permits the irradiation of blood bags in only one bath without compromising the homogeneity of the absorbed dose over the irradiated volume. Thus, these irradiation volumes can be recommend to minimize the irradiation time when a teletherapy unit is used to irradiate blood.

  20. Solar central receiver prototype heliostat CDRL item B. d. Final technical report, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Easton, C. R.

    1978-08-01

    This is volume II of a two volume report which presents the results of a study to define a low-cost approach to the production, installation, and operation of heliostats for central receiver solar thermal power plants. Performance and cost analyses are presented, and critical R and D areas are identified. Also, computer printed work sheets are included for heliostat investment, maintenance equipment investment, initial spares investment, and first years operations and maintenance for 2,500, 25,000, 250,000, and 1,000,000 units per year production. (WHK)

  1. Central hemodynamics in risk assessment strategies: additive value over and above brachial blood pressure.

    Science.gov (United States)

    Yannoutsos, Alexandra; Rinaldi, Elisa R; Zhang, Yi; Protogerou, Athanassios D; Safar, Michel E; Blacher, Jacques

    2015-01-01

    Although the clinical relevance of brachial blood pressure (BP) measurement for cardiovascular (CV) risk stratification is nowadays widely accepted, this approach can nevertheless present several limitations. Pulse pressure (PP) amplification accounts for the notable increase in PP from central to peripheral arterial sites. Target organs are more greatly exposed to central hemodynamic changes than peripheral organs. The pathophysiological significance of local BP pulsatility, which has a role in the pathogenesis of target organ damage in both the macro- and the microcirculation, may therefore not be accurately captured by brachial BP as traditionally evaluated with cuff measurements. The predictive value of central systolic BP and PP over brachial BP for major clinical outcomes has been demonstrated in the general population, in elderly adults and in patients at high CV risk, irrespective of the invasive or non-invasive methods used to assess central BP. Aortic stiffness, timing and intensity of wave reflections, and cardiac performance appear as major factors influencing central PP. Great emphasis has been placed on the role of aortic stiffness, disturbed arterial wave reflections and their intercorrelation in the pathophysiological mechanisms of CV diseases as well as on their capacity to predict target organ damage and clinical events. Comorbidities and age-related changes, together with gender-related specificities of arterial and cardiac parameters, are known to affect the predictive ability of central hemodynamics on individual CV risk. PMID:25341861

  2. Ionic events during the volume response of human peripheral blood lymphocytes to hypotonic media. I. Distinctions between volume- activated Cl- and K+ conductance pathways

    OpenAIRE

    1984-01-01

    Human peripheral blood lymphocytes (PBL), when placed into hypotonic media, first swell and then shrink back to their original volumes because of a rapid KCl leakage via volume-activated K+ and anion permeation pathways. By using gramicidin, a cation channel-forming ionophore, cation transport through the cell membrane can be shunted so that the salt fluxes and thus the volume changes are limited by the rate of the net anion movements. The "gramicidin method," supplemented with direct measure...

  3. Central limit theorems for the excursion sets volumes of weakly dependent random fields

    CERN Document Server

    Bulinski, Alexander; Timmermann, Florian

    2010-01-01

    The multivariate central limit theorems (CLT) for the volumes of excursion sets of stationary quasi-associated random fields on $\\mathbb{R}^d$ are proved. Special attention is paid to Gaussian and shot noise fields. Formulae for the covariance matrix of the limiting distribution are provided. Statistical versions of the CLT are considered as well. They employ three different estimators of the asymptotic covariance matrix. Some numerical results are also discussed.

  4. In vivo volume and hemoglobin dynamics of human red blood cells.

    Directory of Open Access Journals (Sweden)

    Roy Malka

    2014-10-01

    Full Text Available Human red blood cells (RBCs lose ∼30% of their volume and ∼20% of their hemoglobin (Hb content during their ∼100-day lifespan in the bloodstream. These observations are well-documented, but the mechanisms for these volume and hemoglobin loss events are not clear. RBCs shed hemoglobin-containing vesicles during their life in the circulation, and this process is thought to dominate the changes in the RBC physical characteristics occurring during maturation. We combine theory with single-cell measurements to investigate the impact of vesiculation on the reduction in volume, Hb mass, and membrane. We show that vesicle shedding alone is sufficient to explain membrane losses but not volume or Hb losses. We use dry mass measurements of human RBCs to validate the models and to propose that additional unknown mechanisms control volume and Hb reduction and are responsible for ∼90% of the observed reduction. RBC population characteristics are used in the clinic to monitor and diagnose a wide range of conditions including malnutrition, inflammation, and cancer. Quantitative characterization of cellular maturation processes may help in the early detection of clinical conditions where maturation patterns are altered.

  5. Impedance cardiography: Pulsatile blood flow and the biophysical and electrodynamic basis for the stroke volume equations

    Directory of Open Access Journals (Sweden)

    Donald P Bernstein

    2010-01-01

    Full Text Available Impedance cardiography (ICG is a branch of bioimpedance pimarily concerned with the determination of left ventricular stroke volume (SV. As implemented, using the transthoracic approach, the technique involves applying a current field longitudinally across a segment of thorax by means of a constant magnitude, high frequency, low amplitude alternating current (AC. By Ohm's Law, the voltage difference measured within the current field is proportional to the electrical impedance Z (Ω. Without ventilatory or cardiac activity, Z is known as the transthoracic, static base impedance Z0. Upon ventricular ejection, a characteristic time dependent cardiac-synchronous pulsatile impedance change is obtained, ΔZ(t, which, when placed electrically in parallel with Z0, constitutes the time-variable total transthoracic impedance Z(t. ΔZ(t represents a dual-element composite waveform, which comprises both the radially-oriented volumetric expansion of and axially-directed forward blood flow within both great thoracic arteries. In its majority, however, ΔZ(t is known to primarily emanate from the ascending aorta. Conceptually, commonly implemented methods assume a volumetric origin for the peak systolic upslope of ΔZ(t, (i.e. dZ/dtmax, with the presumed units of Ω·s-1. A recently introduced method assumes the rapid ejection of forward flowing blood in earliest systole causes significant changes in the velocity-induced blood resistivity variation (Δρb(t, Ωcm·s-1, and it is the peak rate of change of the blood resistivity variation dρb(t/dtmax (Ωcm·s-2 that is the origin of dZ/dtmax. As a consequence of dZ/dtmax peaking in the time domain of peak aortic blood acceleration, dv/dtmax (cm·s-2, it is suggested that dZ/dtmax is an ohmic mean acceleration analog (Ω·s-2 and not a mean flow or velocity surrogate as generally assumed. As conceptualized, the normalized value, dZ/dtmax/Z0, is a dimensionless ohmic mean acceleration equivalent (s-2

  6. Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    2014-01-01

    Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

  7. Variation of red blood cell distribution width and mean platelet volume after moderate endurance exercise.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Tarperi, Cantor; Guidi, Gian Cesare; Schena, Federico

    2014-01-01

    Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217 ± 32 min/week) who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC), reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV); mean corpuscular hemoglobin (MCH); reticulocyte haemoglobin content (Ret CHR); RBC distribution width (RDW), mean platelet volume (MPV). No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease. PMID:25197280

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

    Science.gov (United States)

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

    2016-01-01

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

  9. Immunity to diphtheria and tetanus among blood donors in Arak, central province of Iran.

    Directory of Open Access Journals (Sweden)

    Ali Eslamifar

    2014-06-01

    Full Text Available Tetanus and diphtheria are vaccine-preventable, infectious diseases with significant morbidity and mortality. Immunization by the diphtheria and tetanus toxoid (DT has been applied in Iran for almost 50 years. However, there are very few data about the rate of immunity to these diseases in the adult population. the humoral immunity to tetanus and diphtheria among blood donors in Arak city, central provice of Iran were investigated.A total of 530 consecutive blood donor samples were collected from Blood Transfusion Organization, Central province of Iran. All samples were tested for diphteria and tetanus IgG antibodies using enzyme-linked immunosorbent assay (ELISA.From 530 cases, 91.9% were male and 8.1% were female. 99.6% of cases had protective levels of diphtheria antibody. Protective levels of tetanus antibody were found in 96% of subjects. There was not any significant difference between diphtheria and tetanus antibodies levels and age and sex.The obtained data showed that high proportion of the adult population in Arak have sufficient protection against diphtheria and tetanus. The high protective level of immunity to diphtheria and tetanus in Iran can be due to widespread use of booster vaccines in Iranian high schools and during the military services or for pregnant women in their 3(rd trimester.

  10. Rapid multi-wavelength optical assessment of circulating blood volume without a priori data

    Science.gov (United States)

    Loginova, Ekaterina V.; Zhidkova, Tatyana V.; Proskurnin, Mikhail A.; Zharov, Vladimir P.

    2016-03-01

    The measurement of circulating blood volume (CBV) is crucial in various medical conditions including surgery, iatrogenic problems, rapid fluid administration, transfusion of red blood cells, or trauma with extensive blood loss including battlefield injuries and other emergencies. Currently, available commercial techniques are invasive and time-consuming for trauma situations. Recently, we have proposed high-speed multi-wavelength photoacoustic/photothermal (PA/PT) flow cytometry for in vivo CBV assessment with multiple dyes as PA contrast agents (labels). As the first step, we have characterized the capability of this technique to monitor the clearance of three dyes (indocyanine green, methylene blue, and trypan blue) in an animal model. However, there are strong demands on improvements in PA/PT flow cytometry. As additional verification of our proof-of-concept of this technique, we performed optical photometric CBV measurements in vitro. Three label dyes—methylene blue, crystal violet and, partially, brilliant green—were selected for simultaneous photometric determination of the components of their two-dye mixtures in the circulating blood in vitro without any extra data (like hemoglobin absorption) known a priori. The tests of single dyes and their mixtures in a flow system simulating a blood transfusion system showed a negligible difference between the sensitivities of the determination of these dyes under batch and flow conditions. For individual dyes, the limits of detection of 3×10-6 M‒3×10-6 M in blood were achieved, which provided their continuous determination at a level of 10-5 M for the CBV assessment without a priori data on the matrix. The CBV assessment with errors no higher than 4% were obtained, and the possibility to apply the developed procedure for optical photometric (flow cytometry) with laser sources was shown.

  11. Ischaemic cerebral infarction combined determination of regional cerebral blood flow and volume via SPECT

    International Nuclear Information System (INIS)

    A combined measurement of regional cerebral blood flow (r CBF) and volume (r CBV) by SPECT was performed in 15 patients with ischaemic cerebral infarction. For measurement of r CBF 99mTc-HMPAO was used, and for r CBV 99mTc-labelled red blood cells. Patients with acute or subacute cerebral infarction (n=10) showed elevation of r CBV whereas r CBF was either reduced or elevated. Patients with chronic cerebral infarction (n=5) showed reduction of both r CBF and R CBV. The combined measurement of both r CBF and r CBV by SPECT allows imaging and semiquantitative evaluation of haemodynamic changes in ischaemic cerebral infarction at various stages. The resulting data may be helpful in describing the pathophysiologic compensatory mechanisms. (orig.)

  12. The importance of neurotransmitters in the central control of the blood pressure

    International Nuclear Information System (INIS)

    In anaesthetized cats, the nucleus tractus solitarii (NTS) and the locus coeruleus (LC) were bilaterally superfused through push-pull cannulae with artificial cerebrospinal fluid. Catecholamines were determined in the superfusate by a radioenzymatic assay, gamma-aminobutyric acid (GABA) was determined in the superfusate and homogenate with glutamate by an enzymatic and fluorimetric assay. In the NTS and LC the resting release of catecholamines varied rhythmically. To investigate the function of catecholaminergic neurons and GABAergic neurons of the NTS in cardiovascular control, the influence of experimentally induced blood pressure changes on the rates of release of the endogenous catecholamines dopamine, noradrenaline and adrenaline in the NTS was observed. The decreased noradrenaline and adrenaline release elicited by increases in blood pressure and the reduced release of dopamine induced by decreases in blood pressure suggest a hypertensive function of noradrenaline and adrenaline and a hypotensive role of dopamine at the level of the rostral and intermediate NTS. Bilateral carotid occlusion led to a very pronounced increase in the release rate of GABA in the rostral NTS. This result demonstrate the hypertensive function of GABA in the NTS. Thus underlining the importance of catecholaminergic and GABAergic neurons of the NTS in central cardiovascular control. The GABA-transaminase inhibitor Vigabatrin was injected wistar Kyoto rats and spontaneously hypertensive rats. GABA-Transaminase inhibition was accompanied by an increase of GABA concentration in the rat brain. The administration of Vigabatrin had no influence on the blood pressure but on the body wight of the rats. (Author)

  13. Optimal velocity encoding during measurement of cerebral blood flow volume using phase-contrast magnetic resonance angiography

    Institute of Scientific and Technical Information of China (English)

    Gang Guo; Yonggui Yang; Weiqun Yang

    2011-01-01

    This study investigated the effect of velocity encoding on measurement of brain blood flow and blood volume of inflow and outflow using phase-contrast magnetic resonance angiography. A single two-dimensional phase-contrast magnetic resonance angiography slice was applied perpendicular to the internal carotid artery and the vertebral artery at C2 level. For each subject, the velocity encoding was set from 30 to 90 cm/s with an interval of 10 cm/s for a total of seven settings. Various velocity encodings greatly affected blood flow volume, maximal blood flow velocity and mean blood flow velocity in the internal carotid artery, but did not significantly affect vertebral arteries and jugular veins. When velocity encoding was 60-80 cm/s, the inflow blood volume was 655 ± 118 mL/min, and the outflow volume was 506 ± 186 mL/min. The ratio of outflow/inflow was steady at 0.78-0.83, and there was no aliasing in any of the images. These findings suggest that velocity encodings of 60-80 cm/s should be selected during measurement of cerebral blood flow volume using phase-contrast magnetic resonance angiography.

  14. Scintigraphic method for evaluating reductions in local blood volumes in human extremities

    DEFF Research Database (Denmark)

    Blønd, L; Madsen, Jan Lysgård

    2000-01-01

    experiment. Evaluation of one versus two scintigraphic projections, trials for assessment of the reproducibility, a comparison of the scintigraphic method with a water-plethysmographic method and registration of the fractional reduction in blood volume caused by exsanguination as a result of simple elevation...... were carried out. No significant differences between results obtained by the use of one or two scintigraphic projections were found. The between-subject coefficient of variation was 14% in the lower limb experiment and 11% in the upper limb experiment. The within-subject coefficient of variation was 6...

  15. Effects of thermal stress and exercise on blood volume in humans

    Science.gov (United States)

    Harrison, M. H.

    1985-01-01

    The available experimental data base on the effects of exercise, posture and the environment (heat) on the blood volume, composition and concentration in humans is surveyed in depth to synthesize supportable conclusions. A large disparity is noted in the effective controls which were initiated in previous experimental conditions, resulting in contradictory findings regarding, e.g., hemoconcentrations and hemodilution in response to exercise. Comparisons between the results of exercise and of supine, seated and upright subjects has underscored the importance of gravity in hemoconcentration, particularly in the legs, and the generation of aldotestosterone. Hemoconcentration has been confirmed to increase with exercise in a seated or supine position. Exercise in a heated environment transfers cardiac output from core areas and reduces filtration efficiencies. Also, plasma volume increases, an action which cannot yet be associated with crystalloidal or colloidal influences on the osmotic behavior of cell walls.

  16. Bi-level CPAP does not change central blood flow in preterm infants with respiratory distress syndrome

    OpenAIRE

    Aquilano, Giulia; Galletti, Silvia; Aceti, Arianna; Vitali, Francesca; Faldella, Giacomo

    2014-01-01

    Background Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow. Objective To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support. Design A prospective st...

  17. Model estimation of cerebral hemodynamics between blood flow and volume changes: a data-based modelling approach

    OpenAIRE

    Wei, H L; Zheng, Y; Pan, Y.; Coca, D.; Li, L M; Mayhew, J.E.W.; S. A. Billings

    2008-01-01

    It is well known that there is a dynamic relationship between cerebral blood flow (CBF) and cerebral blood volume (CBV). With increasing applications of functional magnetic resonance imaging (fMRI), where the blood oxygen level dependent (BOLD) signals are recorded, the understanding and accurate modelling of the hemodynamic relationship between CBF and CBV becomes increasingly important. This study presents an empirical and data-based modelling framework for model identification from CBF and...

  18. Clinical significance of regional cerebral blood volume and flow-to-volume ratio in ischemic cerebrovascular disease measeured by SPECT

    International Nuclear Information System (INIS)

    Regional cerebral blood volume (rCBV) and flow-to-volume ratio (rCBF/rCBV) were evaluated for clinical significance in comparison to rCBF and findings in X-ray CT (XCT) and radionuclide (RNA) and contrast angiography (CAG). A total of 109 cases were studied within 90 days after cerebrovascular ischemic attack. CBV SPECT was performed following CBF SPECT with I-123-IMP and RNA with Tc-99m-RBC, and processed for subtraction of I-123 contamination fraction. CBF/CBV images was obtained as the count ratio of CBF to CBV image at the same slice-level. Parametric rCBV and rCBF/rCBV were estimated as the count ratio of the focus to the contralateral normal region of interest. Image findings were scored by visual judgement. Student's t-test was applied for statistical analysis with a significance level of p=0.01. The rCBV-ratio was inversely proportional to rCBF/rCBV-ratio, and was different between the two groups with high and low score on flip-flop perfusion in RNA and among three groups with different postictal neurological course. The ratio was the highest for the group of improved course. The rCBF/rCBV-ratio was possibly correlated to rCBF-ratio, and was different between the two groups with high and low score on low density area in XCT, early perfusion in RNA and arterial stenosis in CAG. In the group of improved course, the ratio was different between the second and the third postictal week's duraiton. These results, therefore, suggest that rCBV-ratio reflects collateral perfusion, and is valuable for assessing postictal prognosis in cerebrovascular disease, and that rCBF/rCBV-ratio may reflect regional oxygen extraction fraction, and is valuable for speculating cerebral perfusion reserve. (author)

  19. Feasibility of Quantifying Arterial Cerebral Blood Volume Using Multiphase Alternate Ascending/Descending Directional Navigation (ALADDIN).

    Science.gov (United States)

    Kim, Ki Hwan; Choi, Seung Hong; Park, Sung-Hong

    2016-01-01

    Arterial cerebral blood volume (aCBV) is associated with many physiologic and pathologic conditions. Recently, multiphase balanced steady state free precession (bSSFP) readout was introduced to measure labeled blood signals in the arterial compartment, based on the fact that signal difference between labeled and unlabeled blood decreases with the number of RF pulses that is affected by blood velocity. In this study, we evaluated the feasibility of a new 2D inter-slice bSSFP-based arterial spin labeling (ASL) technique termed, alternate ascending/descending directional navigation (ALADDIN), to quantify aCBV using multiphase acquisition in six healthy subjects. A new kinetic model considering bSSFP RF perturbations was proposed to describe the multiphase data and thus to quantify aCBV. Since the inter-slice time delay (TD) and gap affected the distribution of labeled blood spins in the arterial and tissue compartments, we performed the experiments with two TDs (0 and 500 ms) and two gaps (300% and 450% of slice thickness) to evaluate their roles in quantifying aCBV. Comparison studies using our technique and an existing method termed arterial volume using arterial spin tagging (AVAST) were also separately performed in five subjects. At 300% gap or 500-ms TD, significant tissue perfusion signals were demonstrated, while tissue perfusion signals were minimized and arterial signals were maximized at 450% gap and 0-ms TD. ALADDIN has an advantage of visualizing bi-directional flow effects (ascending/descending) in a single experiment. Labeling efficiency (α) of inter-slice blood flow effects could be measured in the superior sagittal sinus (SSS) (20.8±3.7%.) and was used for aCBV quantification. As a result of fitting to the proposed model, aCBV values in gray matter (1.4-2.3 mL/100 mL) were in good agreement with those from literature. Our technique showed high correlation with AVAST, especially when arterial signals were accentuated (i.e., when TD = 0 ms) (r = 0

  20. Feasibility of Quantifying Arterial Cerebral Blood Volume Using Multiphase Alternate Ascending/Descending Directional Navigation (ALADDIN)

    Science.gov (United States)

    Kim, Ki Hwan; Choi, Seung Hong; Park, Sung-Hong

    2016-01-01

    Arterial cerebral blood volume (aCBV) is associated with many physiologic and pathologic conditions. Recently, multiphase balanced steady state free precession (bSSFP) readout was introduced to measure labeled blood signals in the arterial compartment, based on the fact that signal difference between labeled and unlabeled blood decreases with the number of RF pulses that is affected by blood velocity. In this study, we evaluated the feasibility of a new 2D inter-slice bSSFP-based arterial spin labeling (ASL) technique termed, alternate ascending/descending directional navigation (ALADDIN), to quantify aCBV using multiphase acquisition in six healthy subjects. A new kinetic model considering bSSFP RF perturbations was proposed to describe the multiphase data and thus to quantify aCBV. Since the inter-slice time delay (TD) and gap affected the distribution of labeled blood spins in the arterial and tissue compartments, we performed the experiments with two TDs (0 and 500 ms) and two gaps (300% and 450% of slice thickness) to evaluate their roles in quantifying aCBV. Comparison studies using our technique and an existing method termed arterial volume using arterial spin tagging (AVAST) were also separately performed in five subjects. At 300% gap or 500-ms TD, significant tissue perfusion signals were demonstrated, while tissue perfusion signals were minimized and arterial signals were maximized at 450% gap and 0-ms TD. ALADDIN has an advantage of visualizing bi-directional flow effects (ascending/descending) in a single experiment. Labeling efficiency (α) of inter-slice blood flow effects could be measured in the superior sagittal sinus (SSS) (20.8±3.7%.) and was used for aCBV quantification. As a result of fitting to the proposed model, aCBV values in gray matter (1.4–2.3 mL/100 mL) were in good agreement with those from literature. Our technique showed high correlation with AVAST, especially when arterial signals were accentuated (i.e., when TD = 0 ms) (r = 0

  1. Infiltration Pattern of Blood Monocytes into the Central Nervous System during Experimental Herpes Simplex Virus Encephalitis.

    Directory of Open Access Journals (Sweden)

    Rafik Menasria

    Full Text Available The kinetics and distribution of infiltrating blood monocytes into the central nervous system and their involvement in the cerebral immune response together with resident macrophages, namely microglia, were evaluated in experimental herpes simplex virus 1 (HSV-1 encephalitis (HSE. To distinguish microglia from blood monocyte-derived macrophages, chimeras were generated by conditioning C57BL/6 recipient mice with chemotherapy regimen followed by transplantation of bone morrow-derived cells that expressed the green fluorescent protein. Mice were infected intranasally with a sub-lethal dose of HSV-1 (1.2 x 10(6 plaque forming units. Brains were harvested prior to and on days 4, 6, 8 and 10 post-infection for flow cytometry and immunohistochemistry analysis. The amounts of neutrophils (P < 0.05 and "Ly6C hi" inflammatory monocytes (P < 0.001 significantly increased in the CNS compared to non-infected controls on day 6 post-infection, which corresponded to more severe clinical signs of HSE. Levels decreased on day 8 for both leukocytes subpopulations (P < 0.05 for inflammatory monocytes compared to non-infected controls to reach baseline levels on day 10 following infection. The percentage of "Ly6C low" patrolling monocytes significantly increased (P < 0.01 at a later time point (day 8, which correlated with the resolution phase of HSE. Histological analysis demonstrated that blood leukocytes colonized mostly the olfactory bulb and the brainstem, which corresponded to regions where HSV-1 particles were detected. Furthermore, infiltrating cells from the monocytic lineage could differentiate into activated local tissue macrophages that express the microglia marker, ionized calcium-binding adaptor molecule 1. The lack of albumin detection in the brain parenchyma of infected mice showed that the infiltration of blood leukocytes was not necessarily related to a breakdown of the blood-brain barrier but could be the result of a functional recruitment. Thus

  2. Next generation of non-mammalian blood-brain barrier models to study parasitic infections of the central nervous system

    OpenAIRE

    Siddiqui, Ruqaiyyah; Edwards-Smallbone, James; Flynn, Robin; Khan, Naveed Ahmed

    2012-01-01

    Transmigration of neuropathogens across the blood-brain barrier is a key step in the development of central nervous system infections, making it a prime target for drug development. The ability of neuropathogens to traverse the blood-brain barrier continues to inspire researchers to understand the specific strategies and molecular mechanisms that allow them to enter the brain. The availability of models of the blood-brain barrier that closely mimic the situation in vivo offers unprecedented o...

  3. The forgotten role of central volume in low frequency oscillations of heart rate variability.

    Directory of Open Access Journals (Sweden)

    Manuela Ferrario

    Full Text Available The hypothesis that central volume plays a key role in the source of low frequency (LF oscillations of heart rate variability (HRV was tested in a population of end stage renal disease patients undergoing conventional hemodialysis (HD treatment, and thus subject to large fluid shifts and sympathetic activation. Fluid overload (FO in 58 chronic HD patients was assessed by whole body bioimpedance measurements before the midweek HD session. Heart Rate Variability (HRV was measured using 24-hour Holter electrocardiogram recordings starting before the same HD treatment. Time domain and frequency domain analyses were performed on HRV signals. Patients were retrospectively classified in three groups according to tertiles of FO normalized to the extracellular water (FO/ECW%. These groups were also compared after stratification by diabetes mellitus. Patients with the low to medium hydration status before the treatment (i.e. 1st and 2nd FO/ECW% tertiles showed a significant increase in LF power during last 30 min of HD compared to dialysis begin, while no significant change in LF power was seen in the third group (i.e. those with high pre-treatment hydration values. In conclusion, several mechanisms can generate LF oscillations in the cardiovascular system, including baroreflex feedback loops and central oscillators. However, the current results emphasize the role played by the central volume in determining the power of LF oscillations.

  4. Low Prevalence of Brucella Agglutinins in Blood Donors in Central Province of Iran

    Directory of Open Access Journals (Sweden)

    Masoomeh Sofian

    2013-03-01

    Full Text Available Background: Brucellosis is a zoonotic disease of worldwide distribution and has great economic importance. Despite its control in many countries, it remains endemic in Iran. Brucellosis was investigated in many high risk occupational groups; however, few studies on the prevalence of brucellosis among blood donors are available. To determine the seroprevalence of brucellosis antibodies in blood donors, a serological study was carried out in central province of Iran.Materials and Methods: A total of 897 healthy blood donors with mean age 37.23 ± 10.9 years were enrolled in the study. Laboratory tests including Standard Tube Agglutination Test (STA and 2-mercaptoethanol (2ME agglutination were checked in all samples. STA dilution ≥ 1:80, and in the presence of 2-mercaptoethanol (2ME agglutination ≥ 20 was considered positive.Results: Out of 897 cases, 11.9% were inhabitants of rural areas. 41.5% had history of consumption of unpasteurized dairy products and 9.3% had history of contact with domestic animals. A very low level of Brucella agglutinins was present in 3(0.33% of the samples and only one sample (0.11% was found to be truly positive for Brucella agglutinins. 2ME was negative in all samples. None of these 4 subjects showed signs and symptoms of brucellosis in 6 months follow-up.Conclusion: On the basis of our data, brucellosis has no epidemiological and clinical importance in our blood donors; therefore, it is not recommended to perform screening tests such as, STA and 2ME to identify brucellosis antibodies in the sera of blood donors.

  5. Endotracheal cuff pressure and tracheal mucosal blood flow: endoscopic study of effects of four large volume cuffs.

    OpenAIRE

    Archer, P; Brooker, J

    1984-01-01

    Large volume, low pressure endotracheal tube cuffs are claimed to have less deleterious effect on tracheal mucosa than high pressure, low volume cuffs. Low pressure cuffs, however, may easily be overinflated to yield pressures that will exceed capillary perfusion pressure. Various large volume cuffed endotracheal tubes were studied, including Portex Profile, Searle Sensiv, Mallinkrodt Hi-Lo, and Lanz. Tracheal mucosal blood flow in 40 patients undergoing surgery was assessed using an endoscop...

  6. Atrial natriuretic peptide decreases blood volume in intact and anephric rats

    International Nuclear Information System (INIS)

    Atrial natriuretic peptide (ANP) reportedly lowers atrial pressure and increases hematocrit, suggesting venodilation and/or decreased blood volume (BV). To examine these possibilities, rat ANP (99-126) was administered to Inactinanesthetized rats (313 +/- 9 g, +/- SE) at 0.5 μg/kg/min for 30 minutes. Urine flow increased by 0.05 ml/min (p 51Cr-RBC) decreased by 3.4 ml/kg (p < 0.001). Mean circulatory filling pressure, measured by inflating an intracardiac balloon to briefly stop the circulation, did not change. Distribution of BV between the thoracic and spanchnic organs (whole-animal freezing in liquid nitrogen) was not measurably altered. The results suggest that the decrease in CVP was related more to decreased BV than to venodilation. To investigate possible mechanisms for the decreased BV, the same dose of ANP was administered to anephric rats. MAP decreased by 8 mmHg (p < 0.001); hematocrit increased by 2.4 units (p < 0.001) and BV decreased by 1.7 ml/kg (p < 0.05). The results indicate that short-term administration of ANP decreases blood volume by causing intravascular fluid to shift into the interstitium as well as by inducing diuresis

  7. Blood Volume Changes Induced By Low-Intensity Intradialytic Exercise in Long-Term Hemodialysis Patients.

    Science.gov (United States)

    Ookawara, Susumu; Miyazawa, Haruhisa; Ito, Kiyonori; Ueda, Yuichiro; Kaku, Yoshio; Hirai, Keiji; Hoshino, Taro; Mori, Honami; Yoshida, Izumi; Morishita, Yoshiyuki; Tabei, Kaoru

    2016-01-01

    Intradialytic exercise-induced blood volume (BV) reduction may cause intradialytic hypotension in hemodialysis (HD) patients. However, BV recovery time after intradialytic exercise remains unknown. Hemodialysis patients were recruited, and their relative BV change (%ΔBV) were measured with intradialytic exercise (n = 12). After confirming the linearity of %ΔBV for 30 min, patients exercised using a stationary cycle in the supine position. The target exercise intensity was a 10% increase in heart rate (HR), corresponding to relatively low-intensity exercise. Baseline %ΔBV (assumed baseline) were calculated for the 30 min before exercise using linear regression analysis. The mean intradialytic exercise start and end times after HD initiation were 93.0 ± 8.4 and 116.4 ± 8.3 min, respectively, a mean exercise duration of 23.5 ± 2.6 min. Percentage change in blood volume declined rapidly upon exercise initiation and gradually increased above the assumed baseline throughout HD. At the end of HD, %ΔBV in the exercise group was significantly higher than the assumed baseline (measured - assumed baseline %ΔBV: 2.17 ± 0.62%; p = 0.02). Intradialytic exercise with low intensity in the supine position attenuated ultrafiltration-induced BV reduction at the end of HD. Therefore, intradialytic exercise may prevent intradialytic hypotension during later HD, although its intensity was relatively low level. PMID:26720736

  8. The role of blood vessels in high-resolution volume conductor head modeling of EEG.

    Science.gov (United States)

    Fiederer, L D J; Vorwerk, J; Lucka, F; Dannhauer, M; Yang, S; Dümpelmann, M; Schulze-Bonhage, A; Aertsen, A; Speck, O; Wolters, C H; Ball, T

    2016-03-01

    Reconstruction of the electrical sources of human EEG activity at high spatio-temporal accuracy is an important aim in neuroscience and neurological diagnostics. Over the last decades, numerous studies have demonstrated that realistic modeling of head anatomy improves the accuracy of source reconstruction of EEG signals. For example, including a cerebro-spinal fluid compartment and the anisotropy of white matter electrical conductivity were both shown to significantly reduce modeling errors. Here, we for the first time quantify the role of detailed reconstructions of the cerebral blood vessels in volume conductor head modeling for EEG. To study the role of the highly arborized cerebral blood vessels, we created a submillimeter head model based on ultra-high-field-strength (7T) structural MRI datasets. Blood vessels (arteries and emissary/intraosseous veins) were segmented using Frangi multi-scale vesselness filtering. The final head model consisted of a geometry-adapted cubic mesh with over 17×10(6) nodes. We solved the forward model using a finite-element-method (FEM) transfer matrix approach, which allowed reducing computation times substantially and quantified the importance of the blood vessel compartment by computing forward and inverse errors resulting from ignoring the blood vessels. Our results show that ignoring emissary veins piercing the skull leads to focal localization errors of approx. 5 to 15mm. Large errors (>2cm) were observed due to the carotid arteries and the dense arterial vasculature in areas such as in the insula or in the medial temporal lobe. Thus, in such predisposed areas, errors caused by neglecting blood vessels can reach similar magnitudes as those previously reported for neglecting white matter anisotropy, the CSF or the dura - structures which are generally considered important components of realistic EEG head models. Our findings thus imply that including a realistic blood vessel compartment in EEG head models will be helpful to

  9. Improved motion robustness of remote-PPG by using the blood volume pulse signature

    International Nuclear Information System (INIS)

    Remote photoplethysmography (rPPG) enables contact-free monitoring of the blood volume pulse using a color camera. Essentially, it detects the minute optical absorption changes caused by blood volume variations in the skin. In this paper, we show that the different absorption spectra of arterial blood and bloodless skin cause the variations to occur along a very specific vector in a normalized RGB-space. The exact vector can be determined for a given light spectrum and for given transfer characteristics of the optical filters in the camera. We show that this ‘signature’ can be used to design an rPPG algorithm with a much better motion robustness than the recent methods based on blind source separation, and even better than the chrominance-based methods we published earlier. Using six videos recorded in a gym, with four subjects exercising on a range of fitness devices, we confirm the superior motion robustness of our newly proposed rPPG methods. A simple peak detector in the frequency domain returns the correct pulse-rate for 68% of total measurements compared to 60% for the best previous method, while the SNR of the pulse-signal improves from  − 5 dB to  − 4 dB. For a large population of 117 stationary subjects we prove that the accuracy is comparable to the best previous method, although the SNR of the pulse-signal drops from  + 8.4 dB to  + 7.6 dB. We expect the improved motion robustness to significantly widen the application scope of the rPPG-technique. (paper)

  10. Mechanisms of proximal tubule sodium transport regulation that link extracellular fluid volume and blood pressure.

    Science.gov (United States)

    McDonough, Alicia A

    2010-04-01

    One-hundred years ago, Starling articulated the interdependence of renal control of circulating blood volume and effective cardiac performance. During the past 25 years, the molecular mechanisms responsible for the interdependence of blood pressure (BP), extracellular fluid volume (ECFV), the renin-angiotensin system (RAS), and sympathetic nervous system (SNS) have begun to be revealed. These variables all converge on regulation of renal proximal tubule (PT) sodium transport. The PT reabsorbs two-thirds of the filtered Na(+) and volume at baseline. This fraction is decreased when BP or perfusion pressure is increased, during a high-salt diet (elevated ECFV), and during inhibition of the production of ANG II; conversely, this fraction is increased by ANG II, SNS activation, and a low-salt diet. These variables all regulate the distribution of the Na(+)/H(+) exchanger isoform 3 (NHE3) and the Na(+)-phosphate cotransporter (NaPi2), along the apical microvilli of the PT. Natriuretic stimuli provoke the dynamic redistribution of these transporters along with associated regulators, molecular motors, and cytoskeleton-associated proteins to the base of the microvilli. The lipid raft-associated NHE3 remains at the base, and the nonraft-associated NaPi2 is endocytosed, culminating in decreased Na(+) transport and increased PT flow rate. Antinatriuretic stimuli return the same transporters and regulators to the body of the microvilli associated with an increase in transport activity and decrease in PT flow rate. In summary, ECFV and BP homeostasis are, at least in part, maintained by continuous and acute redistribution of transporter complexes up and down the PT microvilli, which affect regulation of PT sodium reabsorption in response to fluctuations in ECFV, BP, SNS, and RAS. PMID:20106993

  11. Optical oximetry of volume-oscillating vascular compartments: contributions from oscillatory blood flow.

    Science.gov (United States)

    Kainerstorfer, Jana M; Sassaroli, Angelo; Fantini, Sergio

    2016-10-01

    We present a quantitative analysis of dynamic diffuse optical measurements to obtain oxygen saturation of hemoglobin in volume oscillating compartments. We used a phasor representation of oscillatory hemodynamics at the heart rate and respiration frequency to separate the oscillations of tissue concentrations of oxyhemoglobin (O) and deoxyhemoglobin (D) into components due to blood volume (subscript V V ) and blood flow (subscript F F ): O=O V +O F O=OV+OF , D=D V +D F D=DV+DF . This is achieved by setting the phase angle Arg(O F )−Arg(O) Arg(OF)−Arg(O) , which can be estimated by a hemodynamic model that we recently developed. We found this angle to be −72  deg −72  deg for the cardiac pulsation at 1 Hz, and −7  deg −7  deg for paced breathing at 0.1 Hz. Setting this angle, we can obtain the oxygen saturation of hemoglobin of the volume-oscillating vascular compartment, S V =|O V |/(|O V |+|D V |) SV=|OV|/(|OV|+|DV|) . We demonstrate this approach with cerebral near-infrared spectroscopy measurements on healthy volunteers at rest (n=4 n=4 ) and during 0.1 Hz paced breathing (n=3 n=3 ) with a 24-channel system. Rest data at the cardiac frequency were used to calculate the arterial saturation, S (a) S(a) ; over all subjects and channels, we found ⟨S V ⟩=⟨S (a) ⟩=0.96±0.02 ⟨SV⟩=⟨S(a)⟩=0.96±0.02 . In the case of paced breathing, we found ⟨S V ⟩=0.66±0.14 ⟨SV⟩=0.66±0.14 , which reflects venous-dominated hemodynamics at the respiratory frequency. PMID:26926870

  12. Central blood circulation in children at chronic combined low dose radiation and chemical action

    International Nuclear Information System (INIS)

    The state of central blood circulation and its hormonal regulation were studied in 1465 children living permanently under chronic low dose radiation and chemical action. Basic group consisted of 1093 children (579 boys and 514 girls) . 372 children (115 boys and 227 girls permanently living on 'clean' areas) were investigated in control group. Average age was 10,8 years old in basic group and 10,4 years old in the control group. Such parameters as arterial pressure, level of lead in blood and urine, adrenaline, noradrenaline and dophamine content in urine, thyroxine, iodothyronine, prostaglandins and cyclic AMP content in the blood serum has been controlled. Hypotensive states were determined to prevail in children living permanently under chronic low dose radiation and chemical action. The main pathogenic mechanism of this defeat is consider to be a reduction of the sympathoadrenal system activity combined with a decreasing of the thyroid system activity and of cyclic AMP level as well as predominance of prostaglandin depressive activity

  13. Evaluation of line focus solar central power systems. Volume II. Systems evaluation

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-15

    An evaluation was completed to ascertain the applicability of line focus technologies to electrical power applications and to compare their performance and cost potential with point focus central receiver power systems. It was concluded that although the high temperature line focus (SRI) and fixed mirror line focus (GA) concepts duplicate the heat source characteristics and power conversion technology of the central receiver concepts these configurations do not offer a sufficient improvement in cost to warrant full scale development. The systems are, however, less complex than their point focus counterpart and should the central receiver system development falter they provide reasonable technology alternatives. The parabolic trough concept (BDM) was found to provide a low temperature technology alternative to the central receiver concept with promising performance and cost potential. Its continued development is recommended, with special emphasis on lower temperature (< 700/sup 0/F) applications. Finally, a variety of new promising line focus power system configurations were identified for a range of utility and industrial applications and recommendations were made on their implementation. This volume contains the detailed report. (WHK)

  14. Forecasting the Future Food Service World of Work. Final Report. Volume II. Centralized Food Service Systems. Service Management Reports.

    Science.gov (United States)

    Powers, Thomas F., Ed.; Swinton, John R., Ed.

    Volume II of a three-volume study on the future of the food service industry considers the effects that centralized food production will have on the future of food production systems. Based on information from the Fair Acres Project and the Michigan State University Vegetable Processing Center, the authors describe the operations of a centralized…

  15. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume III. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    The overall, long term objective of the Solar Central Receiver Hybrid Power System is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumpton, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains appendices to the conceptual design and systems analysis studies gien in Volume II, Books 1 and 2. (WHK)

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

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Marlies, E-mail: marlies.wagner@kgu.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Kyriakou, Yiannis, E-mail: yiannis.kyriakou@siemens.com [Siemens AG, Health Care Sector (Germany); Mesnil de Rochemont, Richard du, E-mail: mesnil@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Singer, Oliver C., E-mail: o.singer@em.uni-frankfurt.de [Hospital of Goethe University, Department of Neurology (Germany); Berkefeld, Joachim, E-mail: berkefeld@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany)

    2013-08-01

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

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

    International Nuclear Information System (INIS)

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

  18. Reference values of central blood pressure and pulse wave velocity in relation with 24 hours ambulatory blood pressure monitoring in Belgian healthy young subjects

    OpenAIRE

    Saint-Remy, Annie; Krzesinski, Jean-Marie

    2010-01-01

    The present study aimed to define reference values of central blood pressure (cBP) and Pulse Wave Velocity (PWV) together with 24H ABPM in healthy normotensive young adults before starring a follow-up of their CV profile modifications over time. Peer reviewed

  19. Reference values of central blood pressure and pulse wave velocity in relations with 24 hours ambulatory blood pressure monitoring in Belgian normotensive young subjects

    OpenAIRE

    Saint-Remy, Annie; Krzesinski, Jean-Marie

    2010-01-01

    The present study aimed to define reference values of central blood pressure (cBP) and Pulse Wave Velocity (PWV) together with 24H APPM in healththy normotensive young adults before starting a follow-up of their CV profile modifications over time. Peer reviewed

  20. Perfusion computed tomography of intracranial meningiomas: In vivo correlation of cerebral blood volume and vascular permeability

    Science.gov (United States)

    Granata, Francesca; Morabito, Rosa; Alafaci, Concetta; Barresi, Valeria; Tomasello, Francesco; Vinci, Sergio; Calamuneri, Alessandro; Grasso, Giovanni; Salpietro, Francesco Maria; Longo, Marcello

    2015-01-01

    Background A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Methods Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour were obtained. Two correspondent regions of interest (ROIs) were drawn on CBV and PS maps. Central and peripheral CBV and PS mean values were calculated. PCT parameters were correlated to CD-34 and endoglin. Results There was a positive correlation between PS and CD-34. No correlation was found between PS values and endoglin, CBV values and CD-34 and endoglin values. Conclusion Our findings suggest that PCT may support conventional morphological imaging in predicting meningioma grading before surgery. PMID:26246100

  1. Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B;

    1996-01-01

    to be in accordance with results obtained by other methods. Noncontrast functional MR (fMR) imaging showed signal increases in gray matter, but also inconsistent changes in some white matter regions. CONCLUSION: In this experiment, contrast-enhanced imaging seemed to show a somewhat higher sensitivity towards changes......PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... by fitting a gamma-variate function to the data. The tissue concentration vs time curves were deconvoluted using an input function obtained by arterial sampling. RESULTS: The ratio of gray to white matter CBV (1.9-2.5) as well as the fractional increase in rCBV during hypercapnia (about 30%) was found...

  2. Reference values for total blood volume and cardiac output in humans

    Energy Technology Data Exchange (ETDEWEB)

    Williams, L.R. [Indiana Univ., South Bend, IN (United States). Division of Liberal Arts and Sciences

    1994-09-01

    Much research has been devoted to measurement of total blood volume (TBV) and cardiac output (CO) in humans but not enough effort has been devoted to collection and reduction of results for the purpose of deriving typical or {open_quotes}reference{close_quotes} values. Identification of normal values for TBV and CO is needed not only for clinical evaluations but also for the development of biokinetic models for ultra-short-lived radionuclides used in nuclear medicine (Leggett and Williams 1989). The purpose of this report is to offer reference values for TBV and CO, along with estimates of the associated uncertainties that arise from intra- and inter-subject variation, errors in measurement techniques, and other sources. Reference values are derived for basal supine CO and TBV in reference adult humans, and differences associated with age, sex, body size, body position, exercise, and other circumstances are discussed.

  3. The pleth variability index as an indicator of the central extracellular fluid volume in mechanically ventilated patients after anesthesia induction: Comparison with initial distribution volume of glucose

    OpenAIRE

    Lu, Wenqing; Dong, Jing; Xu, Zifeng; Shen, Hao; Zheng, Jijian

    2014-01-01

    Background The pleth variability index (PVI) has been demonstrated to be a useful, noninvasive indicator of continuous fluid responsiveness. Whether PVI can be used to assess the changes of intravascular volume status remains to be elucidated. Material/Methods Using correlation analysis and receiver operating characteristic (ROC) curves, we sought a correlation between PVI and the initial distribution volume of glucose (IDVG), evaluating PVI as an indicator of the central extracellular fluid ...

  4. Loss of alveolar membrane diffusing capacity and pulmonary capillary blood volume in pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Farha Samar

    2013-01-01

    Full Text Available Abstract Background Reduced gas transfer in patients with pulmonary arterial hypertension (PAH is traditionally attributed to remodeling and progressive loss of pulmonary arterial vasculature that results in decreased capillary blood volume available for gas exchange. Methods We tested this hypothesis by determination of lung diffusing capacity (DL and its components, the alveolar capillary membrane diffusing capacity (Dm and lung capillary blood volume (Vc in 28 individuals with PAH in comparison to 41 healthy individuals, and in 19 PAH patients over time. Using single breath simultaneous measure of diffusion of carbon monoxide (DLCO and nitric oxide (DLNO, DL and Dm were respectively determined, and Vc calculated. Dm and Vc were evaluated over time in relation to standard clinical indicators of disease severity, including brain natriuretic peptide (BNP, 6-minute walk distance (6MWD and right ventricular systolic pressure (RVSP by echocardiography. Results Both DLCO and DLNO were reduced in PAH as compared to controls and the lower DL in PAH was due to loss of both Dm and Vc (all p CO of PAH patients did not change over time, DLNO decreased by 24 ml/min/mmHg/year (p = 0.01. Consequently, Dm decreased and Vc tended to increase over time, which led to deterioration of the Dm/Vc ratio, a measure of alveolar-capillary membrane functional efficiency without changes in clinical markers. Conclusions The findings indicate that lower than normal gas transfer in PAH is due to loss of both Dm and Vc, but that deterioration of Dm/Vc over time is related to worsening membrane diffusion.

  5. Effect of Model Type on the Accuracy of Polarization and Nephelometric Measurements of Red-Blood-Cell Volume

    Science.gov (United States)

    Kugeiko, M. M.; Smunev, D. A.

    2016-05-01

    The effect of using different mathematical models of a red blood cell on the accuracy of the measured average volume for a population of red blood cells was evaluated. The accuracy was estimated based on regression equations between the retrieved microphysical and measured optical properties. Models of a sphere, oblate spheroid, and biconcave discoid represented as a disc with rounded edges and concavities in the middle were analyzed. It was shown that the error of the regression equations when determining the average red-blood-cell volume using the biconcave discoid model was 1%; spheroid, ~8%; and sphere, ~21%. The error of the average volume due to the model is a few percent for the spheroid and ~20% for the sphere.

  6. Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

    International Nuclear Information System (INIS)

    Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMRglu) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMRglu measurements also were obtained. Before PVC, regional values of CBF were significantly (pglu in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMRglu, but not CBF, was detected in hippocampus and amygdala, before but not after PVC. PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes. (orig.)

  7. Influence of regional cerebral blood volume on voxel-based morphometry.

    Science.gov (United States)

    Zheng, Lei; Cleppien, Dirk; Gass, Natalia; Falfan-Melgoza, Claudia; Vollmayr, Barbara; Hesser, Jürgen; Weber-Fahr, Wolfgang; Sartorius, Alexander

    2016-06-01

    The investigation of structural brain alterations is one focus in research of brain diseases like depression. Voxel-based morphometry (VBM) based on high-resolution 3D MRI images is a widely used non-invasive tool for such investigations. However, the result of VBM might be sensitive to local physiological parameters such as regional cerebral blood volume (rCBV) changes. In order to investigate whether rCBV changes may contribute to variation in VBM, we performed analyses in a study with the congenital learned helplessness (cLH) model for long-term findings. The 3D structural and rCBV data were acquired with T2 -weighted rapid acquisition with relaxation enhancement (RARE) pulse sequences. The group effects were determined by standard statistical parametric mapping (SPM) and biological parametric mapping (BPM) and examined further using atlas-based regions. In our genetic animal model of depression, we found co-occurrence of differences in gray matter volume and rCBV, while there was no evidence of significant interaction between both. However, the multimodal analysis showed similar gray matter differences compared with the standard VBM approach. Our data corroborate the idea that two group VBM differences might not be influenced by rCBV differences in genetically different strains. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27074152

  8. Postoperative volume balance

    DEFF Research Database (Denmark)

    Frost, H; Mortensen, C.R.; Secher, N H;

    2016-01-01

    In healthy humans, stroke volume (SV) and cardiac output (CO) do not increase with expansion of the central blood volume by head-down tilt or administration of fluid. Here, we exposed 85 patients to Trendelenburg's position about one hour after surgery while cardiovascular variables were determined...

  9. Correlation between stroke volume variation and blood volume during hypovolemia%低血容量状态下患者每搏量变异度与血容量的相关性

    Institute of Scientific and Technical Information of China (English)

    李文静; 李健; 彭科; 姜亚辉; 张慧娟; 嵇富海

    2012-01-01

    目的 探讨低血容量状态下患者每搏量变异度(SVV)与血容量的相关性.方法 择期骨科手术患者20例,年龄20 ~ 64岁,BMI 20 ~ 30 kg/m2,ASA分级Ⅰ或Ⅱ级.气管插管后,稳定5 min,记录HR、MAP、CVP、动脉压力波形监测的心排量(APCO)、SVV、全身血管阻力(SVR)和心脏指数(CI).以30 ~ 50 ml/min的速率从中心静脉取血,取血量为全身血容量的5%,待血液动力学稳定5 min后记录上述血液动力学指标;再次以上述方法采血并记录血液动力学指标;随后以50 ~ 70 ml/min的速率经右侧颈内静脉输注相当于全身血容量5%的6%羟乙基淀粉130/0.4,待血液动力学稳定5 min后记录血液动力学指标;再次以上述方法补液并记录血液动力学指标.血容量变化(各时点血容量与基础值的差值)与dSVV(各时点监测值与基础值的差值)行线性相关分析.结果 每次血容量变化后SVV、APCO和CI与前一状态比较差异均有统计学意义(P<0.05或0.01),每次血容量变化后HR、MAP、CVP和SVR与前一状态比较差异并非均有统计学意义;dSVV与血容量变化呈负相关(r=-0.875,P<0.01).结论 低容量状态下SVV与血容量的相关性较高,可准确反映血容量的变化,可用于指导低血量容状态下的容量治疗.%Objective To investigate the correlation between stroke volume variation (SVV) and blood volume during hypovolemia.Methods Twenty ASA Ⅰ or Ⅱ patients,aged 20-64 yr,with body mass index 20-30 kg/m2,scheduled for elective orthopedic operation,were studied.Anesthesia was induced with dexamethasone,midazolam,propofol,fentanyl and cisatracurium and maintained with sevoflurane,fentanyl and cisatracurium.The patients were tracheal intubated and mechanically ventilated.HR,MAP,CVP,arterial pressure-based cardiac output (APCO),SVV,systemic vascular resistance (SVR) and cardiac index (CI) were recorded 5 min after tracheal intubation.Blood was taken from central vein at a

  10. Relationship of blood pressure variability and heart rate variability with prostatic volume in patients with benign prostatic hyperplasia

    Institute of Scientific and Technical Information of China (English)

    金江丽

    2014-01-01

    Objective To investigate the relationship of blood pressure variability(BPV)and heart rate variability(HRV)with prostatic volume(PV)in patients with benign prostatic hyperplasia(BPH).Methods A total of133 patients admitted to our department between January2011 and April 2013 were analyzed retrospectively.The patients were divided into BPH group and non-BPH group according to the PV value.The ambulatory blood

  11. Functional Response of Tumor Vasculature to PaCO2: Determination of Total and Microvascular Blood Volume by MRI

    Directory of Open Access Journals (Sweden)

    Scott D. Packard

    2003-07-01

    Full Text Available In order to identify differences in functional activity, we compared the reactivity of glioma vasculature and the native cerebral vasculature to both dilate and constrict in response to altered PaCO2. Gliomas were generated by unilateral implantation of U87MGdEGFR human glioma tumor cells into the striatum of adult female athymic rats. Relative changes in total and microvascular cerebral blood volume were determined by steady state contrast agent-enhanced magnetic resonance imaging for transitions from normocarbia to hypercarbia and hypocarbia. Although hypercarbia induced a significant increase in both total and microvascular blood volume in normal brain and glioma, reactivity of glioma vasculature was significantly blunted in comparison to normal striatum; glioma total CBV increased by 0.6±0.1%/mm Hg CO2 whereas normal striatum increased by 1.5±0.2%/mm Hg CO2, (P < .0001, group t-test. Reactivity of microvascular blood volume was also significantly blunted. In contrast, hypocarbia decreased both total and microvascular blood volumes more in glioma than in normal striatum. These results indicate that cerebral blood vessels derived by tumor-directed angiogenesis do retain reactivity to CO2. Furthermore, reduced reactivity of tumor vessels to a single physiological perturbation, such as hypercarbia, should not be construed as a generalized reduction of functional activity of the tumor vascular bed.

  12. Reduction in cerebral blood flow volume in infants complicated with hypoxic ischemic encephalopathy resulting in cerebral palsy.

    Science.gov (United States)

    Fukuda, Sumio; Mizuno, Keisuke; Kawai, Satomi; Kakita, Hiroki; Goto, Tatenobu; Hussein, Mohamed Hamed; Daoud, Ghada A; Ito, Tetsuya; Kato, Ineko; Suzuki, Satoshi; Togari, Hajime

    2008-04-01

    Hypoxic ischemic brain can result in cerebral palsy, mental retardation, and learning disabilities in surviving children. The purpose of this study was to elucidate the cerebral blood flow volume in infants complicated with brain damage after the birth. Nine term infants with hypoxic ischemic encephalopathy and 41 normal term infants were studied. Four infants with HIE suffered from CP or mental retardation, and the other five infants exhibited normal neurodevelopment. The mean blood flow velocity and diameter of the internal carotid artery and the vertebral artery were measured for 28 days. The intravascular flow volume was determined by calculating the flow velocity and the cross-sectional area. The ejection fraction and cardiac output were obtained, and the mean blood pressures were recorded. The summed flow volumes in both the ICA and VA, and the total CBFV increased after the birth in both the normal infants and the infants diagnosed with HIE with no disability complications. The total blood flow volume was significantly lower in infants with HIE and CP than in normal infants on days 0, 2, 5, 7, 10, 21, and 28, and significantly lower in infants with HIE and CP than in normal infants with HIE on days 2, 4, and 7. The ejection fraction was significantly lower in infants with HIE than in normal infants only on day 0. Our results suggest that the total cerebral blood supply is decreased in infants with HIE in those complicated with brain damage. PMID:17950550

  13. Determination of the volume of circulating blood by means of in vivo labelled red blood cells with 99mTc pertechnetate and use of a Bulgarian kit

    International Nuclear Information System (INIS)

    A method was proposed for determination of the circulating blood volume (CBV) by means of in vivo labelled red blood cells, which was compared to the routine method with 51Cr-sodium chromate. To the patients concecutively was given 1 g of potassium perchlorate (for blocking of the organs, which actively absorbed the perchnetate ion) and 500 mkg of tin pyrophosphate (Bulgarian kit) with subsequent labelling of the red blood cells with 99mTc-pertechnate (1,8 - 3,7 MBq). The volume of the red blood cells, and hence also CBV, was measured with the use of a modified by the authors formula, in which correction for the individual effectiveness of the cell labelling was done. In comparison with the standard method for in vitro labelling of the red blood cells with 51Cr sodium chromate, the method proposed gave an insignificant difference of 4,16%, but when compared to the commercial tin pyrophosphate (of the firm Mallinckrot - Holland), the Bulgarian kit displayed equivalent qualities. It was concluded that the method has a high accuracy and was easy for execution, cause a low radiation burden of the patient and is suitable for application in nuclear cardiology and radionuclide angiography

  14. Methodology and technology for peripheral and central blood pressure and blood pressure variability measurement: current status and future directions - Position statement of the European Society of Hypertension Working Group on blood pressure monitoring and cardiovascular variability.

    Science.gov (United States)

    Stergiou, George S; Parati, Gianfranco; Vlachopoulos, Charalambos; Achimastos, Apostolos; Andreadis, Emanouel; Asmar, Roland; Avolio, Alberto; Benetos, Athanase; Bilo, Grzegorz; Boubouchairopoulou, Nadia; Boutouyrie, Pierre; Castiglioni, Paolo; de la Sierra, Alejandro; Dolan, Eamon; Head, Geoffrey; Imai, Yutaka; Kario, Kazuomi; Kollias, Anastasios; Kotsis, Vasilis; Manios, Efstathios; McManus, Richard; Mengden, Thomas; Mihailidou, Anastasia; Myers, Martin; Niiranen, Teemu; Ochoa, Juan Eugenio; Ohkubo, Takayoshi; Omboni, Stefano; Padfield, Paul; Palatini, Paolo; Papaioannou, Theodore; Protogerou, Athanasios; Redon, Josep; Verdecchia, Paolo; Wang, Jiguang; Zanchetti, Alberto; Mancia, Giuseppe; O'Brien, Eoin

    2016-09-01

    Office blood pressure measurement has been the basis for hypertension evaluation for almost a century. However, the evaluation of blood pressure out of the office using ambulatory or self-home monitoring is now strongly recommended for the accurate diagnosis in many, if not all, cases with suspected hypertension. Moreover, there is evidence that the variability of blood pressure might offer prognostic information that is independent of the average blood pressure level. Recently, advancement in technology has provided noninvasive evaluation of central (aortic) blood pressure, which might have attributes that are additive to the conventional brachial blood pressure measurement. This position statement, developed by international experts, deals with key research and practical issues in regard to peripheral blood pressure measurement (office, home, and ambulatory), blood pressure variability, and central blood pressure measurement. The objective is to present current achievements, identify gaps in knowledge and issues concerning clinical application, and present relevant research questions and directions to investigators and manufacturers for future research and development (primary goal). PMID:27214089

  15. Rapid and Efficient Generation of Transgene-Free iPSC from a Small Volume of Cryopreserved Blood.

    Science.gov (United States)

    Zhou, Hongyan; Martinez, Hector; Sun, Bruce; Li, Aiqun; Zimmer, Matthew; Katsanis, Nicholas; Davis, Erica E; Kurtzberg, Joanne; Lipnick, Scott; Noggle, Scott; Rao, Mahendra; Chang, Stephen

    2015-08-01

    Human peripheral blood and umbilical cord blood represent attractive sources of cells for reprogramming to induced pluripotent stem cells (iPSCs). However, to date, most of the blood-derived iPSCs were generated using either integrating methods or starting from T-lymphocytes that have genomic rearrangements thus bearing uncertain consequences when using iPSC-derived lineages for disease modeling and cell therapies. Recently, both peripheral blood and cord blood cells have been reprogrammed into transgene-free iPSC using the Sendai viral vector. Here we demonstrate that peripheral blood can be utilized for medium-throughput iPSC production without the need to maintain cell culture prior to reprogramming induction. Cell reprogramming can also be accomplished with as little as 3000 previously cryopreserved cord blood cells under feeder-free and chemically defined Xeno-free conditions that are compliant with standard Good Manufacturing Practice (GMP) regulations. The first iPSC colonies appear 2-3 weeks faster in comparison to previous reports. Notably, these peripheral blood- and cord blood-derived iPSCs are free of detectable immunoglobulin heavy chain (IGH) and T cell receptor (TCR) gene rearrangements, suggesting they did not originate from B- or T- lymphoid cells. The iPSCs are pluripotent as evaluated by the scorecard assay and in vitro multi lineage functional cell differentiation. Our data show that small volumes of cryopreserved peripheral blood or cord blood cells can be reprogrammed efficiently at a convenient, cost effective and scalable way. In summary, our method expands the reprogramming potential of limited or archived samples either stored at blood banks or obtained from pediatric populations that cannot easily provide large quantities of peripheral blood or a skin biopsy. PMID:25951995

  16. Expression of Astrocytic Type 2 Angiotensin Receptor in Central Nervous System Inflammation Correlates With Blood-Brain Barrier Breakdown

    DEFF Research Database (Denmark)

    Füchtbauer, Laila; Toft-Hansen, Henrik; Khorooshi, Reza;

    2010-01-01

    The blood-brain barrier (BBB), a complex of endothelial and glial barriers, controls passage of cells and solutes between the blood and central nervous system (CNS). Blood-brain barrier breakdown refers to entry of cells and/or solutes. We were interested whether the renin-angiotensin system is...... involved during BBB breakdown. We studied the type 2 angiotensin receptor AT(2) because of its suggested neuroprotective role. Two models of brain inflammation were used to distinguish solute versus cellular barrier functions. Both leukocytes and horseradish peroxidase (HRP) accumulated in the perivascular...

  17. Next generation of non-mammalian blood-brain barrier models to study parasitic infections of the central nervous system

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Edwards-Smallbone, James; Flynn, Robin; Khan, Naveed Ahmed

    2012-01-01

    Transmigration of neuropathogens across the blood-brain barrier is a key step in the development of central nervous system infections, making it a prime target for drug development. The ability of neuropathogens to traverse the blood-brain barrier continues to inspire researchers to understand the specific strategies and molecular mechanisms that allow them to enter the brain. The availability of models of the blood-brain barrier that closely mimic the situation in vivo offers unprecedented opportunities for the development of novel therapeutics. PMID:21921682

  18. Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI) as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels) were studied with percent flow volume (the ratio of actual flow volume to measured flow volume). The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries. (author)

  19. Knowledge and Attitude about Blood Donation Amongst Undergraduate Students of Pravara Institute of Medical Sciences Deemed University of Central India

    Directory of Open Access Journals (Sweden)

    Purushottam A Giri

    2012-01-01

    Full Text Available Background: The major part of demand for blood in India is met through voluntary blood donations. Students consists a large and healthy group who are able to provide a large number of blood donation. However, there is a paucity of studies on knowledge and attitude among undergraduate students from medical and paramedical branches. Objectives: A present study was conducted to assess the knowledge and attitude about blood donation among undergraduate medical science university students. Materials and Methods: A cross-sectional study was conducted among 400 final year undergraduate students from medical, dental, nursing, and physiotherapy disciplines in a Pravara institute of Medical Sciences University campus of central India during the period of May- August 2011. Data was analyzed in the form of percentage and proportions and Chi-square test. Results: The overall knowledge on blood donation was good; however, majority (52.5% of students never donated blood. Knowledge level was found highest among medical students (53.1% and lowest among physiotherapy students (20.7%. Non-consideration, forgetfulness, and lack of time were the major reasons for not donating blood. A significant association was observed between different streams of students and levels of knowledge and attitude about blood donation. Conclusion: This study elicits the importance of adopting effective measures in our campus to motivate about voluntary blood donation among students.

  20. Predictors of high central blood pressure in young with isolated systolic hypertension

    Directory of Open Access Journals (Sweden)

    Radchenko GD

    2016-08-01

    Full Text Available G D Radchenko, O O Torbas, Yu M Sirenko State Institute National Scientific Center, M.D. Strazhesko Institute of Cardiology, National Academy of Medical Science, Kyiv, Ukraine Objective: According to the European Society of Cardiology/European Society of Hypertension 2013 guidelines, evaluation of aortic blood pressure (BP is needed in young with isolated systolic hypertension (ISH, but using special devices is not common, especially in Ukraine, where only a few centers have these devices. The purpose of our study was to identify the simple clinical predictors for differentiation (with or without elevated aortic systolic BP [SBP] of the young with ISH without the need for further extensive work-up. Patients and methods: The study included 44 young men (mean age: 32.2±1.3 years with office SBP ≥140 mmHg and office diastolic BP (DBP <90 mmHg (average: 153.4±2.1 mmHg and 83.4±1.7 mmHg, respectively. The following procedures were performed in all the subjects: body weight and height evaluation; measurement of office SBP, DBP, and heart rate; ambulatory BP monitoring; measurement of pulse wave velocity in arteries of elastic and muscle types and central SBP (cSBP; biochemical blood tests; electrocardiography; echocardiography; and carotid ultrasound investigations. Step-by-step multifactor regression analyses were used for finding the predictors of high cSBP. Results: Depending on the cSBP level, all the patients were divided into two groups: first group (n=17, subjects with normal cSBP, and second group (n=27, subjects with elevated cSBP. Patients in the second group were significantly older, with less height and higher body mass index; they had significantly higher levels of office SBP and DBP. Characteristics of target organ damage were within normal limits in both groups and did not differ significantly. Only pulse wave velocity in arteries of elastic type was significantly higher in the second group. The independent predictors of

  1. Left ventricular volume unloading with axial and centrifugal rotary blood pumps.

    Science.gov (United States)

    Giridharan, Guruprasad A; Koenig, Steven C; Soucy, Kevin G; Choi, Young; Pirbodaghi, Tohid; Bartoli, Carlo R; Monreal, Gretel; Sobieski, Michael A; Schumer, Erin; Cheng, Allen; Slaughter, Mark S

    2015-01-01

    Axial (AX) and centrifugal (CFG) rotary blood pumps have gained clinical acceptance for the treatment of advanced heart failure. Differences between AX and CFG designs and mechanism of blood flow delivery may offer clinical advantages. In this study, pump characteristics, and acute physiologic responses during support with AX (HeartMate II) and CFG (HVAD) left ventricular assist devices (LVAD) were investigated in mock loop and chronic ischemic heart failure bovine models. In the mock loop model, pump performance was characterized over a range of pump speeds (HeartMate II: 7,000-11,000 rpm, HVAD: 2,000-3,600 rpm) and fluid viscosities (2.7 cP, 3.2 cP, 3.7 cP). In the ischemic heart failure bovine model, hemodynamics, echocardiography, and end-organ perfusion were investigated. CFG LVAD had a flatter HQ curve, required less power, and had a more linear flow estimation relation than AX LVAD. The flow estimation error for the AX LVAD (±0.9 L/min at 2.7 cP, ±0.7 L/min at 3.2 cP, ±0.8 L/min at 3.7 cP) was higher than the CFG LVAD (±0.5 L/min at 2.7 cP, ±0.2 L/min at 3.2 cP, ±0.5 L/min at 3.7 cP). No differences in acute hemodynamics, echocardiography, or end-organ perfusion between AX and CFG LVAD over a wide range of support were statistically discernible. These findings suggest no pronounced acute differences in LV volume unloading between AX and CFG LVAD. PMID:25635936

  2. Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

    Energy Technology Data Exchange (ETDEWEB)

    Giovacchini, Giampiero [University Milano-Bicocca, Milan (Italy); Bonwetsch, Robert; Theodore, William H. [National Institute of Neurological Diseases and Strokes, Clinical Epilepsy Section, Bethesda, MD (United States); Herscovitch, Peter [National Institutes of Health, PET Department, Clinical Center, Bethesda, MD (United States); Carson, Richard E. [Yale PET Center, New Haven, CT (United States)

    2007-12-15

    Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR{sub glu}) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR{sub glu} measurements also were obtained. Before PVC, regional values of CBF were significantly (p<0.05) lower in TLE patients than in controls in all regions, except the fusiform gyrus contralateral to the epileptic focus. After PVC, statistical significance was maintained in only four regions: ipsilateral inferior temporal cortex, bilateral insula and contralateral amygdala. There was no significant difference between patients and controls in CBF asymmetry indices (AIs) in any region before or after PVC. In TLE patients, AIs for CBF were significantly smaller than for CMR{sub glu} in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR{sub glu}, but not CBF, was detected in hippocampus and amygdala, before but not after PVC. PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes. (orig.)

  3. A study on the pulmonary mean transit time and the pulmonary blood volume by RI-cardiogram

    International Nuclear Information System (INIS)

    The pulmonary mean transit time and the pulmonary blood volume in cases of cardio-pulmonary disease were measured using Giuntini's method which is considered the most appropriate among radiocardiographic methods. The errors in this method were confirmed to be almost negligible. The results obtained were as follows: 1) The pulmonary mean transit time was related to the systemic mean transit time and markedly prolonged in left heart failure. On the other hand, it was markedly shortened in some cases of chronic pulmonary disease, particularly pulmonary emphysema. 2) The pulmonary blood volume tended to increase in left heart disorders and mitral valve disease and tended to decrease in the chronic pulmonary disease. The decrease was conspicuous particularly in some cases of pulmonary emphysema. 3) A structural change of the pulmonary vascular system in the chronic pulmonary disease appeared to bring about shortening of the pulmonary mean transit time and a decrease in the pulmonary blood volume. The pathophysiology of cardio-pulmonary disease can be more clarified by the RI-cardiogram used in this study, in which the pulmonary mean transit time and the pulmonary blood volume are used as the indicator. (author)

  4. Quantitative measurement of human tissue hepatic blood volume by C{sup 15}O inhalation with positron-emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Hiroki; Masuyama, Mamoru; Koyama, Hiroshi; Oguro, Atsushi; Takahashi, Toshio [Kyoto Prefectural Univ. of Medicine, First Dept. of Surgery, Kyoto (Japan)

    1996-08-01

    In order to estimate the tissue liver function, tissue hepatic blood volume was measured quantitatively and non-invasively using C{sup 15}0 inhalation in conjunction with positron-emission tomography. Fifty-eight patients with normal liver function, 14 patients with chronic hepatitis, 28 patients with hepatic cirrhosis, and 4 patients with obstructive jaundice were studied by positron-emission tomography scan after the single breath inhalation of 20 mCi of high specific activity {sup 1}25O-labeled carbon monoxide. The mean tissue hepatic blood volume was significantly grater in patients with normal livers in patients with chronic hepatitis or hepatic cirrhosis (mean: 20.5, 18.2, and 16.1 ml per 100 cm{sup 3}, respectively, p=8.6x10{sup -8}). Tissue hepatic blood volume (tHBV) correlated with the reaction of the mesenchymal system and protein synthesis, because there was a potent correlation between tHBV and hepatic fibrosis. In normal livers, we were able to demonstrate significant differences in tissue hepatic blood volume among liver segments. (au) 8 refs.

  5. Importance of blood cultures from peripheral veins in pediatric patients with cancer and a central venous line

    DEFF Research Database (Denmark)

    Handrup, Mette Møller; Møller, Jens Kjølseth; Rutkjaer, Cecilie; Schrøder, Henrik

    2015-01-01

    When an infection is suspected in a child with cancer and a central venous line (CVL), cultures are often only obtained from the CVL and not from a peripheral vein (PV). This study was undertaken to evaluate the importance of concomitant blood cultures from the CVL and a PV....

  6. MR-based cerebral blood volume maps as a diagnostic tool for brain tumours

    International Nuclear Information System (INIS)

    Today contrast enhanced MR imaging is a reliable method for detecting mostly distinguishing between different histological types of tumours. In this study we use a MR-based method to measure the regional cerebral blood volume (rCBV). Using this technique we try to judge the grading and vitality of the tumours. 26 patients with various types of brain tumours were examined. To calculate rCBV-maps of one slice, low-dosed Gd-DTPA was injected as a bolus. Using the relaxation effect the obtained signal intensity-time curves were converted pixel-wise into rCBV images. For the tumours rCBV-ratios were calculated relative to the corresponding area in the contralateral hemisphere. In the investigated group all tumours were detected on the basis of a raised rCBV-ratio. Since only vital parts of the tumour are perfused, the rCBV maps may be used to determine the place of biopsy. (orig./MG)

  7. Pulmonary blood volume imaging with dual-energy computed tomography: Spectrum of findings

    Energy Technology Data Exchange (ETDEWEB)

    Hagspiel, K.D., E-mail: kdh2n@virginia.edu [Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, Virginia (United States); Flors, L.; Housseini, A.M.; Phull, A. [Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, Virginia (United States); Ali Ahmad, E. [Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, Virginia (United States); Department of Radiology, Minia University, Minia (Egypt); Bozlar, U.; Norton, P.T. [Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, Virginia (United States); Bonatti, H.J.R. [Department of Surgery, University of Virginia Health System, Charlottesville, Virginia (United States)

    2012-01-15

    Dual-energy (DE) pulmonary blood volume (PBV) computed tomography (CT) has recently become available on clinical CT systems. The underlying physical principle of DECT is the fact that the photoelectric effect is strongly dependent on the CT energies resulting in different degrees of x-ray attenuation for different materials at different energy levels. DECT thus enables the characterization and quantification of iodine within tissues via imaging at different x-ray energies and analysis of attenuation differences. Technical approaches to DECT include dual-source scanners acquiring two scans with different energy levels simultaneously, and single-source CT scanners using sandwich detectors or rapid voltage switching. DE PBV CT enables the creation of iodine maps of the pulmonary parenchyma. Experience to date shows that these studies can provide additional physiological information in patients with acute or chronic pulmonary embolism beyond the pure morphological assessment a standard CT pulmonary angiography (CTPA) provides. It appears also to be promising for the evaluation of patients with obstructive airways disease. This article reviews the physics and technical aspects of DE PBV CT as well as the appearance of normal and abnormal lung tissue on these studies. Special consideration is given to pitfalls and artefacts.

  8. Comparison of pathogen DNA isolation methods from large volumes of whole blood to improve molecular diagnosis of bloodstream infections.

    Directory of Open Access Journals (Sweden)

    Anne J M Loonen

    Full Text Available For patients suffering from bloodstream infections (BSI molecular diagnostics from whole blood holds promise to provide fast and adequate treatment. However, this approach is hampered by the need of large blood volumes. Three methods for pathogen DNA isolation from whole blood were compared, i.e. an enzymatic method (MolYsis, 1-5 ml, the novel non-enzymatic procedure (Polaris, 1-5 ml, and a method that does not entail removal of human DNA (Triton-Tris-EDTA EasyMAG, 200 µl. These methods were evaluated by processing blood spiked with 0-1000 CFU/ml of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Downstream detection was performed with real-time PCR assays. Polaris and MolYsis processing followed by real-time PCRs enabled pathogen detection at clinically relevant concentrations of 1-10 CFU/ml blood. By increasing sample volumes, concurrent lower cycle threshold (Ct values were obtained at clinically relevant pathogen concentrations, demonstrating the benefit of using larger blood volumes. A 100% detection rate at a concentration of 10 CFU/ml for all tested pathogens was obtained with the Polaris enrichment, whereas comparatively lower detection rates were measured for MolYsis (50-67% and EasyMAG (58-79%. For the samples with a concentration of 1 CFU/ml Polaris resulted in most optimal detection rates of 70-75% (MolYsis 17-50% and TTE-EasyMAG 20-36%. The Polaris method was more reproducible, less labour intensive, and faster (45 minutes (including Qiagen DNA extraction vs. 2 hours (MolYsis. In conclusion, Polaris and MolYsis enrichment followed by DNA isolation and real-time PCR enables reliable and sensitive detection of bacteria and fungi from 5 ml blood. With Polaris results are available within 3 hours, showing potential for improved BSI diagnostics.

  9. Volume Transmission in Central Dopamine and Noradrenaline Neurons and Its Astroglial Targets.

    Science.gov (United States)

    Fuxe, Kjell; Agnati, Luigi F; Marcoli, Manuela; Borroto-Escuela, Dasiel O

    2015-12-01

    Already in the 1960s the architecture and pharmacology of the brainstem dopamine (DA) and noradrenaline (NA) neurons with formation of vast numbers of DA and NA terminal plexa of the central nervous system (CNS) indicated that they may not only communicate via synaptic transmission. In the 1980s the theory of volume transmission (VT) was introduced as a major communication together with synaptic transmission in the CNS. VT is an extracellular and cerebrospinal fluid transmission of chemical signals like transmitters, modulators etc. moving along energy gradients making diffusion and flow of VT signals possible. VT interacts with synaptic transmission mainly through direct receptor-receptor interactions in synaptic and extrasynaptic heteroreceptor complexes and their signaling cascades. The DA and NA neurons are specialized for extrasynaptic VT at the soma-dendrtitic and terminal level. The catecholamines released target multiple DA and adrenergic subtypes on nerve cells, astroglia and microglia which are the major cell components of the trophic units building up the neural-glial networks of the CNS. DA and NA VT can modulate not only the strength of synaptic transmission but also the VT signaling of the astroglia and microglia of high relevance for neuron-glia interactions. The catecholamine VT targeting astroglia can modulate the fundamental functions of astroglia observed in neuroenergetics, in the Glymphatic system, in the central renin-angiotensin system and in the production of long-distance calcium waves. Also the astrocytic and microglial DA and adrenergic receptor subtypes mediating DA and NA VT can be significant drug targets in neurological and psychiatric disease. PMID:25894681

  10. Solar central receiver hybrid power system, Phase I. Volume 3. Appendices. Final technical report, October 1978-August 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-01

    A design study for a central receiver/fossil fuel hybrid power system using molten salts for heat transfer and heat storage is presented. This volume contains the appendices: (A) parametric salt piping data; (B) sample heat exchanger calculations; (C) salt chemistry and salt/materials compatibility evaluation; (D) heliostat field coordinates; (E) data lists; (F) STEAEC program input data; (G) hybrid receiver design drawings; (H) hybrid receiver absorber tube thermal math model; (I) piping stress analysis; (J) 100-MWe 18-hour storage solar central receiver hybrid power system capital cost worksheets; and (K) 500-MWe 18-hour solar central receiver hybrid power system cost breakdown. (WHK)

  11. Blood Volume, Plasma Volume and Circulation Time in a High-Energy-Demand Teleost, the Yellowfin Tuna (Thunnus Albacares)

    DEFF Research Database (Denmark)

    Brill, R.W.; Cousins, K.L.; Jones, D.R.;

    1998-01-01

    We measured red cell space with 51Cr-labeled red blood cells, and dextran space with 500 kDa fluorescein-isothiocyanate-labeled dextran (FITC-dextran), in two groups of yellowfin tuna (Thunnus albacares). Red cell space was 13.8+/-0.7 ml kg-1 (mean +/- s.e.m.) Assuming a whole- body hematocrit eq...

  12. Analysis of decrease in lung perfusion blood volume with occlusive and non-occlusive pulmonary embolisms

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Yohei, E-mail: ypfranky1@ybb.ne.jp [Department of Radiology, Niigata University Graduate School of Medical and Dental Science (Japan); Yoshimura, Norihiko [Department of Radiology, Niigata University Graduate School of Medical and Dental Science (Japan); Hori, Yoshiro [Department of Radiology, Showa University Fujigaoka Hospital (Japan); Horii, Yosuke; Ishikawa, Hiroyuki [Department of Radiology, Niigata University Graduate School of Medical and Dental Science (Japan); Yamazaki, Motohiko [Department of Radiology, Niigata City General Hospital (Japan); Noto, Yoshiyuki [Department of Radiology, Niigata University Medical and Dental Hospital (Japan); Aoyama, Hidefumi [Department of Radiology, Niigata University Graduate School of Medical and Dental Science (Japan)

    2014-12-15

    Highlights: • The proportion of preserved PE lesions in the non-occlusive group was 76.7% (33/43). • HUs of the iodine map were significantly higher in the non-occlusive group than in the occlusive group. • There was no significant difference in HUs between the non-occlusive and corresponding normal group. - Abstract: Purpose: The aim of this study was to determine if lung perfusion blood volume (lung PBV) with non-occlusive pulmonary embolism (PE) differs quantitatively and visually from that with occlusive PE and to investigate if lung PBV with non-occlusive PE remains the same as that without PE. Materials and methods: Totally, 108 patients suspected of having acute PE underwent pulmonary dual-energy computed tomography angiography (DECTA) between April 2011 and January 2012. Presence of PE on DECTA was evaluated by one radiologist. Two radiologists visually evaluated the PE distribution (segmental or subsegmental) and its nature (occlusive or non-occlusive) on DECTA and classified perfusion in lung PBV as “decreased,” “slightly decreased,” and “preserved”. Two radiologists used a lung PBV application to set a region of interest (ROI) in the center of the lesion and measured HU values of an iodine map. In the same slice as the ROI of the lesion and close to the lesion, another ROI was set in the normal perfusion area without PE, and HUs were measured. The proportion of lesions was compared between the occlusive and non-occlusive groups. HUs were compared among the occlusive, non-occlusive, and corresponding normal groups. Results: Twenty-five patients had 80 segmental or subsegmental lesions. There were 37 and 43 lesions in the occlusive and non-occlusive groups, respectively. The proportion of decreased lesions was 73.0% (27/37) in the occlusive group, while that of preserved lesions in the non-occlusive group was 76.7% (33/43). There was a significant difference in the proportion of lesions (P < 0.001) between the two groups. HUs of the

  13. Analysis of decrease in lung perfusion blood volume with occlusive and non-occlusive pulmonary embolisms

    International Nuclear Information System (INIS)

    Highlights: • The proportion of preserved PE lesions in the non-occlusive group was 76.7% (33/43). • HUs of the iodine map were significantly higher in the non-occlusive group than in the occlusive group. • There was no significant difference in HUs between the non-occlusive and corresponding normal group. - Abstract: Purpose: The aim of this study was to determine if lung perfusion blood volume (lung PBV) with non-occlusive pulmonary embolism (PE) differs quantitatively and visually from that with occlusive PE and to investigate if lung PBV with non-occlusive PE remains the same as that without PE. Materials and methods: Totally, 108 patients suspected of having acute PE underwent pulmonary dual-energy computed tomography angiography (DECTA) between April 2011 and January 2012. Presence of PE on DECTA was evaluated by one radiologist. Two radiologists visually evaluated the PE distribution (segmental or subsegmental) and its nature (occlusive or non-occlusive) on DECTA and classified perfusion in lung PBV as “decreased,” “slightly decreased,” and “preserved”. Two radiologists used a lung PBV application to set a region of interest (ROI) in the center of the lesion and measured HU values of an iodine map. In the same slice as the ROI of the lesion and close to the lesion, another ROI was set in the normal perfusion area without PE, and HUs were measured. The proportion of lesions was compared between the occlusive and non-occlusive groups. HUs were compared among the occlusive, non-occlusive, and corresponding normal groups. Results: Twenty-five patients had 80 segmental or subsegmental lesions. There were 37 and 43 lesions in the occlusive and non-occlusive groups, respectively. The proportion of decreased lesions was 73.0% (27/37) in the occlusive group, while that of preserved lesions in the non-occlusive group was 76.7% (33/43). There was a significant difference in the proportion of lesions (P < 0.001) between the two groups. HUs of the

  14. Radionuclide left ventricular absolute volume determination by ejection fraction measurement data and a left posterior oblique blood pool image

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Shinichiro (Saitama Medical School, Moroyama (Japan))

    1989-09-01

    A new method for the calculation of left ventricular volumes called the 'semi-geometric' method, was reported by Nichols et al in 1984. This method, however, still had certain limitations for practical use. This paper describes a modified semi-geometric method in which the left ventricular volume was obtained from conventional left ventricular ejection fraction measurement data collected from the modified left anterior oblique position with a caudal tilt of 10 degrees or more and a left posterior oblique blood pool image. The left ventricular end-diastolic volumes obtained by this method were compared with those calculated by combining the thermodilution cardiac output and the left ventricular ejection fraction. The correlation coefficient was r=0.93 (n=20). In the phantom experiment, the true volumes and those obtained by this method showed an excellent correlation (r=0.99). This method is considered accurate and practical. (author).

  15. Body Weight and Not Exercise Capacity Determines Central Systolic Blood Pressure, a Surrogate for Arterial Stiffness, in Children and Adolescents.

    Science.gov (United States)

    Müller, Jan; Meyer, Joanna; Elmenhorst, Julia; Oberhoffer, Renate

    2016-08-01

    Cardiopulmonary fitness benefits cardiovascular health. Various studies have shown a strong negative correlation between exercise capacity and arterial stiffness in adults. However, evidence for this connection in children and adolescents is scarce. About 320 healthy children and adolescents (252 male, 14.0±2.1 years) were evaluated with regard to their demographic, anthropometric and hemodynamic parameters, and their peak oxygen uptake. Peripheral and central systolic blood pressures were measured with patients in a supine position using an oscillometric device. Peak oxygen uptake was assessed by cardiopulmonary exercise testing. In multivariate regression, only peripheral systolic blood pressure (β=0.653, P<.001) and body weight (β=0.284, P<.001) emerged as independent determinants for central systolic blood pressure. Body weight therefore determines central systolic blood pressure in children and adolescents rather than measures of cardiorespiratory fitness. The prevention of overweight in childhood is necessary to reduce stiffening of the arteries and delay the onset of cardiovascular disease. PMID:26689169

  16. The heritability of glaucoma-related traits corneal hysteresis, central corneal thickness, intraocular pressure, and choroidal blood flow pulsatility.

    Directory of Open Access Journals (Sweden)

    Ellen E Freeman

    Full Text Available PURPOSE: The purpose of this work was to investigate the heritability of potential glaucoma endophenotypes. We estimated for the first time the heritability of the pulsatility of choroidal blood flow. We also sought to confirm the heritability of corneal hysteresis, central corneal thickness, and 3 ways of measuring intraocular pressure. METHODS: Measurements were performed on 96 first-degree relatives recruited from Maisonneuve-Rosemont Hospital in Montreal. Corneal hysteresis was determined using the Reichert Ocular Response Analyser. Central corneal thickness was measured with an ultrasound pachymeter. Three measures of intraocular pressure were obtained: Goldmann-correlated and corneal compensated intraocular pressure using the Ocular Response Analyser, and Pascal intraocular pressure using the Pascal Dynamic Contour Tonometer. The pulsatility of choroidal blood velocity and flow were measured in the sub-foveolar choroid using single-point laser Doppler flowmetry (Oculix. We estimated heritability using maximum-likelihood variance components methods implemented in the SOLAR software. RESULTS: No significant heritability was detected for the pulsatility of choroidal blood flow or velocity. The Goldman-correlated, corneal compensated, and Pascal measures of intraocular pressure measures were all significantly heritable at 0.94, 0.79, and 0.53 after age and sex adjustment (p = 0.0003, p = 0.0023, p = 0.0239. Central corneal thickness was significantly heritable at 0.68 (p = 0.0078. Corneal hysteresis was highly heritable but the estimate was at the upper boundary of 1.00 preventing us from giving a precise estimate. CONCLUSION: Corneal hysteresis, central corneal thickness, and intraocular pressure are all heritable and may be suitable as glaucoma endophenotypes. The pulsatility of choroidal blood flow and blood velocity were not significantly heritable in this sample.

  17. Positron emission tomography in cerebrovascular disease: The relationship between regional cerebral blood flow, blood volume and oxygen metabolism

    International Nuclear Information System (INIS)

    Positron emission tomography in cerebrovascular disease has demonstrated the importance of the relationship between regional cerebral blood flow and the cerebral metabolic activity. In acute stroke it has been found that within the first hours after the onset of symptoms cerebral blood flow in the affected area is more depressed than cerebral oxygen utilisation. This relative preservation of oxygen utilisation results from an increase in the oxygen extraction ratio far above its normal value. However, the oxygen extraction fraction subsequently falls in the following days indicating the transition from a situation of possibly reversible ischaemia to irreversible infarction. In patients with carotid occlusive disease an increase in the oxygen extraction ratio has been observed only in very few cases. It has been shown, however, that at an earlier stage the relationship between CBF and CBV (as CBF/CBV-ratio) provides a sensitive measure of diminished perfusion pressure which could be helpful for the selection of patients for EC-IC bypass surgery. In patients with sickle cell anaemia it has been found that oxygen delivery to the brain is maintained by an increase in cerebral blood flow, whereas the oxygen extraction ratio is not increased despite the presence of a low oxygen affinity haemoglobin. Preliminary observations in classical migraine suggest an ischaemic situation during the attack. (orig.)

  18. Irradiation of blood, blood compounds and cell culture in equipment of radiotherapy of clinical usage. Study about volume and ideal dose

    International Nuclear Information System (INIS)

    The irradiation of blood bags with the objective of minimizing the graft-versus-host disease in the proceedings of blood transfusion has been consolidated as an indispensable step in the advances of hematopoietic system diseases therapeutics. This practice performed in the great oncological treatment centers requires appropriate equipment (cell irradiators), that due to the high coast, is inaccessible to the majority of the services. The main objective of this work is the show the technique developed by the Radiological Physics Service of the Hospital A. C. Camargo Radiation Department, using the teletherapy equipment of clinical usage available at the Institution. The literature shows that a total dose of 2000 to 3500 c Gy must be administered to all target volume to get an ideal dose/volume relation that proportionates better therapeutic results, neutralizing the cells which are causative of post transfusion reactions of rejection, without prejudicing the other cells that are necessary to the maintenance and preservation of the transplanted person's hematopoietic system functions. With the technic developed for optimization of the irradiation. it is possible to conclude that the utilization of radiotherapy equipment of clinical usage for blood irradiation, substituting cells irradiators, is a good option, permitting safe transfusion of products irradiated with adequate dose. (author)

  19. Evaluation of adjusted central venous blood gases versus arterial blood gases of patients in post-operative paediatric cardiac surgical intensive care unit

    Directory of Open Access Journals (Sweden)

    Naveen G Singh

    2015-01-01

    Full Text Available Background and Aims: Central venous catheters are in situ in most of the intensive care unit (ICU patients, which may be an alternative for determining acid-base status and can reduce complications from prolonged arterial cannulation. The aim of this study was to examine the reliability between adjusted central venous blood gas (aVBG and arterial blood gas (ABG samples for pH, partial pressure of carbon-di-oxide (pCO2, bicarbonate (HCO3−, base excess (BE and lactates in paediatric cardiac surgical ICU. Methods: We applied blood gas adjustment rule, that is aVBG pH = venous blood gas (VBG pH +0.05, aVBG CO2 = VBG pCO2 - 5 mm Hg from the prior studies. In this study, we validated this relationship with simultaneous arterial and central venous blood obtained from 30 patients with four blood sample pairs each in paediatric cardiac surgical ICU patients. Results: There was a strong correlation (R i.e., Pearson's correlation between ABG and aVBG for pH = 0.9544, pCO2 = 0.8738, lactate = 0.9741, HCO3− = 0.9650 and BE = 0.9778. Intraclass correlation co-efficients (ICCs for agreement improved after applying the adjustment rule to venous pH (0.7505 to 0.9454 and pCO2 (0.4354 to 0.741. Bland Altman showed bias (and limits of agreement for pH: 0.008 (−0.04 to + 0.057, pCO2: −3.52 (–9.68 to +2.65, lactate: −0.10 (−0.51 to +0.30, HCO3−: −2.3 (–5.11 to +0.50 and BE: −0.80 (−3.09 to +1.49. Conclusion: ABG and aVBG samples showed strong correlation, acceptable mean differences and improved agreement (high ICC after adjusting the VBG. Hence, it can be promising to use trend values of VBG instead of ABG in conjunction with a correction factor under stable haemodynamic conditions.

  20. The measurement of red blood cell volume change induced by Ca2+ based on full field quantitative phase microscopy

    Science.gov (United States)

    Lee, Seungrag; Lee, Ji Yong; Yang, Wenzhong; Kim, Dug Young

    2009-02-01

    We present the measurement of red blood cell (RBC) volume change induced by Ca2+ for a live cell imaging with full field quantitative phase microscopy (FFQPM). FFQPM is based on the Mach-Zehnder interferometer combined with an inverted microscopy system. We present the effective method to obtain a clear image and an accurate volume of the cells. An edge detection technique is used to accurately resolve the boundary between the cell line and the suspension medium. The measurement of the polystyrene bead diameter and volume has been demonstrated the validity of our proposed method. The measured phase profile can be easily converted into thickness profile. The measured polystyrene bead volume and the simulated result are about 14.74 μm3 and 14.14 μm3, respectively. The experimental results of our proposed method agree well with the simulated results within less than 4 %. We have also measured the volume variation of a single RBC on a millisecond time scale. Its mean volume is 54.02 μm3 and its standard deviation is 0.52 μm3. With the proposed system, the shape and volume changes of RBC induced by the increased intracellular Ca2+ are measured after adding ionophore A23187. A discocyte RBC is deformed to a spherocyte due to the increased intracellular Ca2+ in RBC. The volume of the spherocyte is 47.88 μm3 and its standard deviation is 0.19 μm3. We have demonstrated that the volume measurement technique is easy, accurate, and robust method with high volume sensitivity (<0.0000452 μm3) and this provides the ability to study a biological phenomenon in Hematology.

  1. V1a vasopressin receptors maintain normal blood pressure by regulating circulating blood volume and baroreflex sensitivity

    OpenAIRE

    Koshimizu, Taka-aki; Nasa, Yoshihisa; Tanoue, Akito; Oikawa, Ryo; Kawahara, Yuji; Kiyono, Yasushi; ADACHI, TETSUYA; Tanaka, Toshiki; Kuwaki, Tomoyuki; Mori, Toyoki; Takeo, Satoshi; Okamura, Hitoshi; Tsujimoto, Gozoh

    2006-01-01

    Arginine-vasopressin (AVP) is a hormone that is essential for both osmotic and cardiovascular homeostasis, and exerts important physiological regulation through three distinct receptors, V1a, V1b, and V2. Although AVP is used clinically as a potent vasoconstrictor (V1a receptor-mediated) in patients with circulatory shock, the physiological role of vasopressin V1a receptors in blood pressure (BP) homeostasis is ill-defined. In this study, we investigated the functional roles of the V1a recept...

  2. Practical Suitability of a Stand-Alone Oscillometric Central Blood Pressure Monitor: A Review of the Microlife WatchBP Office Central.

    Science.gov (United States)

    Verberk, Willem J; Cheng, Hao-Min; Huang, Li-Chih; Lin, Chia-Ming; Teng, Yao-Pin; Chen, Chen-Huan

    2016-04-01

    Accumulating evidence indicates that central blood pressure (CBP) is a better cardiovascular risk predictor than brachial blood pressure (BP). Although more additional benefits of CBP-based treatment above usual hypertension treatment are to be demonstrated, the demand for implementing CBP assessment in general clinical practice is increasing. For this, the measurement procedure must be noninvasive, easy to perform, and cost- and time-efficient. Therefore, oscillometric devices with the possibility to assess CBP seem the best option. Recently, such an oscillometric BP monitor, the Microlife WatchBP Office Central, was developed, which demonstrated its high accuracy in a validation study against invasive BP measurement. Calibration errors of this device are limited because the procedure is automated, standardized, and performed at the same place of and within 30 s from pulse wave assessment. The transformation from the peripheral pulse wave to CBP is done by means of an individual-based pulse wave analysis according to a theory of arterial compliance and wave reflections. In addition, the device has demonstrated to enable a more reliable diagnosis of hypertension by CBP than by peripheral BP, with a lower frequency of over- and underdiagnosis. Altogether, the available clinical evidence suggests that the Microlife WatchBP Office Central fulfills the criteria for general clinical use. PMID:27195242

  3. A volume-limited sample of X-ray galaxy groups and clusters: III. Central abundance drops

    CERN Document Server

    Panagoulia, Electra K; Fabian, Andy C

    2014-01-01

    We present the results of a search and study of central abundance drops in a volume-limited sample (z<=0.071) of 101 X-ray galaxy groups and clusters. These are best observed in nearby, and so best resolved, groups and clusters, making our sample ideal for their detection. Out of the 65 groups and clusters in our sample for which we have abundance profiles, 8 of them have certain central abundance drops, with possible central abundance drops in another 6. All sources with central abundance drops have X-ray cavities, and all bar one exception have a central cooling time <=1 Gyr. These central abundance drops can be generated if the iron injected by stellar mass loss processes in the core of these sources is in grains, which then become incorporated in the central dusty filaments. These, in turn, are dragged outwards by the bubbling feedback process in these sources. We find that data quality significantly affects the detection of central abundance drops, inasmuch as a higher number of counts in the centr...

  4. The alveolar-capillary membrane diffusing capacity and the pulmonary capillary blood volume in heart transplant candidates

    OpenAIRE

    Al-Rawas, O; Carter, R.; Stevenson, R; Naik, S; Wheatley, D

    2000-01-01

    OBJECTIVES—To determine the mechanism of impairment of pulmonary transfer factor for carbon monoxide (TLCO) in heart transplant candidates, as this is the most common lung function abnormality.
SETTING—Regional cardiopulmonary transplant centre.
METHODS—TLCO and its components (the diffusing capacity of the alveolar-capillary membrane (DM) and the pulmonary capillary blood volume (VC)) were measured using the Roughton and Forster method and the single breath technique in 38 patients with seve...

  5. Dynamic Contrast-Enhanced MRI Assessment of Hyperemic Fractional Microvascular Blood Plasma Volume in Peripheral Arterial Disease: Initial Findings

    OpenAIRE

    Bas Versluis; Marjolein H G Dremmen; Nelemans, Patty J; Wildberger, Joachim E.; Geert-Willem Schurink; Tim Leiner; Walter H Backes

    2012-01-01

    OBJECTIVES: The aim of the current study was to describe a method that assesses the hyperemic microvascular blood plasma volume of the calf musculature. The reversibly albumin binding contrast agent gadofosveset was used in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) to assess the microvascular status in patients with peripheral arterial disease (PAD) and healthy controls. In addition, the reproducibility of this method in healthy controls was determined. MATERIALS AND METH...

  6. Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas

    DEFF Research Database (Denmark)

    Thomsen, Henrik; Larsson, Elna-Marie; Steffensen, Elena

    2012-01-01

    Background: Perfusion magnetic resonance imaging (MRI) is increasingly used in the evaluation of brain tumors. Relative cerebral blood volume (rCBV) is usually obtained by dynamic susceptibility contrast (DSC) MRI using normal appearing white matter as reference region. The emerging perfusion...... glioblastomas. Results: rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r ¼ 0.60) and to the cerebellum (r ¼ 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated...

  7. Ultrasound-mediated blood-brain barrier disruption for targeted drug delivery in the central nervous system

    OpenAIRE

    Aryal, Muna; Arvanitis, Costas D.; Alexander, Phillip M.; McDannold, Nathan

    2014-01-01

    The physiology of the vasculature in the central nervous system (CNS), which includes the blood-brain barrier (BBB) and other factors, complicates the delivery of most drugs to the brain. Different methods have been used to bypass the BBB, but they have limitations such as being invasive, non-targeted or requiring the formulation of new drugs. Focused ultrasound (FUS), when combined with circulating microbubbles, is a noninvasive method to locally and transiently disrupt the BBB at discrete t...

  8. The Heritability of Glaucoma-Related Traits Corneal Hysteresis, Central Corneal Thickness, Intraocular Pressure, and Choroidal Blood Flow Pulsatility

    OpenAIRE

    Freeman, Ellen E.; Roy-Gagnon, Marie-Hélène; Descovich, Denise; Massé, Hugues; Mark R. Lesk

    2013-01-01

    Purpose The purpose of this work was to investigate the heritability of potential glaucoma endophenotypes. We estimated for the first time the heritability of the pulsatility of choroidal blood flow. We also sought to confirm the heritability of corneal hysteresis, central corneal thickness, and 3 ways of measuring intraocular pressure. Methods Measurements were performed on 96 first-degree relatives recruited from Maisonneuve-Rosemont Hospital in Montreal. Corneal hysteresis was determined u...

  9. Changes in central retinal artery blood flow after ocular warming and cooling in healthy subjects

    Directory of Open Access Journals (Sweden)

    Shamshad M

    2010-01-01

    Full Text Available Context: Retinal perfusion variability impacts ocular disease and physiology. Aim: To evaluate the response of central retinal artery (CRA blood flow to temperature alterations in 20 healthy volunteers. Setting and Design: Non-interventional experimental human study. Materials and Methods: Baseline data recorded: Ocular surface temperature (OST in °C (thermo-anemometer, CRA peak systolic velocity (PSV and end diastolic velocity (EDV in cm/s using Color Doppler. Ocular laterality and temperature alteration (warming by electric lamp/cooling by ice-gel pack were randomly assigned. Primary outcomes recorded were: OST and intraocular pressure (IOP immediately after warming or cooling and ten minutes later; CRA-PSV and EDV at three, six and nine minutes warming or cooling. Statistical Analysis: Repeated measures ANOVA. Results: (n = 20; μ±SD: Pre-warming values were; OST: 34.5±1.02°C, CRA-PSV: 9.3±2.33cm/s, CRA-EDV: 4.6±1.27cm/s. OST significantly increased by 1.96°C (95% CI: 1.54 to 2.37 after warming, but returned to baseline ten minutes later. Only at three minutes, the PSV significantly rose by 1.21cm/s (95% CI: 0.51to1.91. Pre-cooling values were: OST: 34.5±0.96°C, CRA-PSV: 9.7±2.45 cm/s, CRA-EDV: 4.7±1.12cm/s. OST significantly decreased by 2.81°C (95% CI: -2.30 to -3.37 after cooling, and returned to baseline at ten minutes. There was a significant drop in CRA-PSV by 1.10cm/s (95% CI: -2.05 to -0.15 and CRA-EDV by 0.81 (95% CI: -1.47 to -0.14 at three minutes. At six minutes both PSV (95% CI: -1.38 to -0.03 and EDV (95% CI: -1.26 to -0.02 were significantly lower. All values at ten minutes were comparable to baseline. The IOP showed insignificant alteration on warming (95% CI of difference: -0.17 to 1.57mmHg, but was significantly lower after cooling (95% CI: -2.95 to -4.30mmHg. After ten minutes, IOP had returned to baseline. Conclusion : This study confirms that CRA flow significantly increases on warming and decreases on cooling

  10. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, J.; Insel, T.R.; Berman, K.F.; Foa, E.B.; Hill, J.L.; Weinberger, D.R.

    1989-06-01

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO/sub 2/ did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow.

  11. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    International Nuclear Information System (INIS)

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO2 did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow

  12. Benidipine has effects similar to losartan on the central blood pressure and arterial stiffness in mild to moderate essential hypertension

    Institute of Scientific and Technical Information of China (English)

    Sang-Hyun Ihm; Hui-Kyung Jeon; Shung Chull Chae; Do-Sun Lim; Kee-Sik Kim; Dong-Ju Choi; Jong-Won Ha

    2013-01-01

    Background Central blood pressure (BP) is pathophysiologically more important than peripheral BP for the pathogenesis of cardiovascular disease.Arterial stiffness is also a good predictor of cardiovascular morbidity and mortality.The effects of benidipine,a unique dual L-/T-type calcium channel blocker,on central BP have not been reported.This study aimed to compare the effect of benidipine and losartan on the central BP and arterial stiffness in mild to moderate essential hypertensives.Methods This 24 weeks,multi-center,open label,randomized,active drug comparative,parallel group study was designed as a non-inferiority study.The eligible patients (n=200) were randomly assigned to receive benidipine (n=101)or losartan (n=99).Radial artery applanation tonometry and pulse wave analysis were used to measure the central BP,pulse wave velocity (PWV) and augmentation index (Alx).We also measured the metabolic and inflammatory markers.Results After 24 weeks,the central BP decreased significantly from baseline by (16.8+14.0/10.5+9.2) mmHg (1mmHg =0.133 kPa) (systolic/diastolic BP; P <0.001) in benidipine group and (18.9+14.7/12.1+10.2) mmHg (P <0.001)in losartan group respectively.Both benidipine and losartan groups significantly lowered peripheral BP (P <0.001) and Alx (P <0.05),but there were no significant differences between the two groups.The mean aortic,brachial and femoral PWV did not change in both groups after 24-week treatment.There were no significant changes of the blood metabolic and inflammatory biomarkers in each group.Conclusion Benidipine is as effective as losartan in lowering the central and peripheral BP,and improving arterial stiffness.

  13. Hydration and blood volume effects on human thermoregulation in the heat: Space applications

    Science.gov (United States)

    Sawka, Michael N.; Gonzalez, Richard R.; Pandolf, Kent B.

    1994-01-01

    Astronauts exposed to prolonged weightlessness will experience deconditioning, dehydration, and hypovolemia which all adversely affect thermoregulation. These thermoregulatory problems can be minimized by several countermeasures that manipulate body water and vascular volumes. USARIEM scientists have extensively studied dehydration effects and several possible countermeasures including hyperhydration, plasma and erythrocyte volume expansion. This paper reviews USARIEM research into these areas.

  14. Effects of 5-HT1B/1D receptor agonist rizatriptan on cerebral blood flow and blood volume in normal circulation.

    Science.gov (United States)

    Okazawa, Hidehiko; Tsuchida, Tatsuro; Pagani, Marco; Mori, Tetsuya; Kobayashi, Masato; Tanaka, Fumiko; Yonekura, Yoshiharu

    2006-01-01

    To investigate the vasoconstrictor effect of 5-hydroxytryptamine (5-HT1B/1D) receptor agonists for migraine treatment, changes in cerebral blood flow (CBF) and blood volume induced by rizatriptan were assessed by positron emission tomography (PET). Eleven healthy volunteers underwent PET studies before and after rizatriptan administration. Dynamic PET data were acquired after bolus injection of H2(15)O to analyze CBF and arterial-to-capillary blood volume (V0) images using the three-weighted integral method. After a baseline scan, three further acquisitions were performed at 40 to 50, 60 and 70 to 80 mins after drug administration. Global and regional differences in CBF and V0 between conditions were compared using absolute values in the whole brain and cortical regions, as well as statistical parametric mapping (SPM) analysis. The global and regional values for CBF and V0 decreased significantly after rizatriptan administration compared with the baseline condition. However, both values recovered to baseline within 80 mins after treatment. The maximal reduction in global CBF and V0 was approximately 13% of baseline value. The greatest decrease in CBF was observed approximately 60 mins after drug administration, whereas the maximal reduction in V0 was observed approximately 5 mins earlier. Statistical parametric mapping did not highlight any regional differences between conditions. Thus, in brain circulation, rizatriptan caused significant CBF and V0 decreases, which are consistent with the vasoconstrictor effect of triptans on the large cerebral arteries. The gradual recovery in the late phase from the maximal CBF and V0 decrease suggests that rizatriptan does not affect the cerebral autoregulatory response in small arteries induced by CBF reduction. PMID:15944648

  15. [Measurement of blood cholesterol, decentralized, using a Reflotron, or centralized in a laboratory. A comparison].

    Science.gov (United States)

    Christensen, T E; Agner, E; Jensen, S E; Jacobsen, K; Mahnfeldt, M S; Baastrup, A

    1990-11-01

    In connection with an extensive screening programme for blood cholesterol, the cholesterol values in 105 participants were measured on a sample of capillary blood employing a Reflotron and, simultaneously, samples of venous blood were examined by conventional enzymatic analysis in a laboratory. Whereas the day-to-day variation and the scatter involved were quite limited in the laboratory, the variation scatter between the two methods of measurement was 0.65 mmol/l. This figure was, however, no greater than that described between different laboratories in USA. Nevertheless, it is an important problem with the Reflotron method that even slight deviations from the recommended procedure of withdrawing blood involve a systematic risk for erroneously low cholesterol results. PMID:2238225

  16. Validation of the pulse decomposition analysis algorithm using central arterial blood pressure

    OpenAIRE

    Baruch, Martin C; Kalantari, Kambiz; Gerdt, David W; Adkins, Charles M

    2014-01-01

    Background There is a significant need for continuous noninvasive blood pressure (cNIBP) monitoring, especially for anesthetized surgery and ICU recovery. cNIBP systems could lower costs and expand the use of continuous blood pressure monitoring, lowering risk and improving outcomes. The test system examined here is the CareTaker® and a pulse contour analysis algorithm, Pulse Decomposition Analysis (PDA). PDA’s premise is that the peripheral arterial pressure pulse is a superposition of five ...

  17. Effect of Sulfonylureas Administered Centrally on the Blood Glucose Level in Immobilization Stress Model

    OpenAIRE

    Sharma, Naveen; Sim, Yun-Beom; Park, Soo-hyun; Lim, Su-Min; Kim, Sung-Su; Jung, Jun-Sub; Hong, Jae-Seung; Suh, Hong-Won

    2015-01-01

    Sulfonylureas are widely used as an antidiabetic drug. In the present study, the effects of sulfonylurea administered supraspinally on immobilization stress-induced blood glucose level were studied in ICR mice. Mice were once enforced into immobilization stress for 30 min and returned to the cage. The blood glucose level was measured 30, 60, and 120 min after immobilization stress initiation. We found that intracerebroventricular (i.c.v.) injection with 30 µg of glyburide, glipizide, glimepir...

  18. Integrated analysis of halogenated organic pollutants in sub-millilitre volumes of venous and umbilical cord blood sera

    Energy Technology Data Exchange (ETDEWEB)

    Grimalt, Joan O.; Carrizo, Daniel; Otero, Raquel; Vizcaino, Esther [Institute of Environmental Assessment and Water Research (IDAeA-CSIC), Department of Environmental Chemistry, Barcelona, Catalonia (Spain); Howsam, Mike [Universite de Lille 2, Centre Universitaire de Mesure et d' Analyse, Faculte de Pharmacie, Lille (France); Rodrigues de Marchi, Mary Rosa [Institute of Chemistry UNESP, Department of Analytical Chemistry, Araraquara, SP (Brazil)

    2010-03-15

    A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs, polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD) and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000{mu}L were extracted and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction of small volumes ({>=}300 {mu}L) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability ranged from 0.1-14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n=73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned halogenated pollutants using this method and the results are briefly described. (orig.)

  19. Detecting variations of blood volume shift due to heart beat from respiratory inductive plethysmography measurements in man

    International Nuclear Information System (INIS)

    The simultaneous study of the cardiac and respiratory activities and their interactions is of great physiological and clinical interest. For this purpose, we want to investigate if respiratory inductive plethysmography (RIP) can be used for cardiac functional exploration. We propose a system, based on RIP technology and time-scale approaches of signal processing, for the extraction of cardiac information. This study focuses on the monitoring of blood volume shift due to heart beat, noted ▵Vtrc and investigates RIP for the detection of ▵Vtrc variations by comparison to stroke volume (SV) variations estimated by impedance cardiography (IMP). We proposed a specific respiratory protocol assumed to induce significant variations of the SV. Fifteen healthy volunteers in the seated and supine positions were asked to alternate rest respiration and maneuvers, consisting in blowing into a manometer. A multi-step treatment including a variant of empirical mode decomposition was applied on RIP signals to extract cardiac volume signals and estimate beat-to-beat ▵Vtrc. These were averaged in quasi-stationary states at rest and during the respiratory maneuvers, and analysed in view of SV estimations from IMP signals simultaneously acquired. Correlation and statistical tests over the data show that RIP can be used to detect variations of the cardiac blood shift in healthy young subjects. (paper)

  20. CORRELATION OF VOLUME BLOOD CIRCULATION IN THE HEPATIC ARTERY AND THE STATE OF MICROCIRCULATORY BLOODSTREAM OF THE TRANSPLANTED LIVER AFTER ITS REVASCULIZATION

    Directory of Open Access Journals (Sweden)

    D. A. Granov

    2014-01-01

    Full Text Available Aim: optimization of the surgical treatment policy with orthotopic liver transplantation (OLT depending on the results of intraoperative fl owmetry and the state of intrahepatic microcirculatory bloodstream according to immunohistochemical (IHC study of microspecimens of the donor’s liver.Materials and methods. 60 patients are included in the study. Group I (n = 30 comprised of patients for whom it was not necessary to perform any additional interventions on the bloodstream in the hepatopancreatobiliary area during OLT. Group II (n = 30 had patients with insuffi cient arterial blood supply for the graft in the intraoperative stage where it was needed to perform additional and/or repeated interventions in the arteries of the hepatopancreatobilliary area. Intraoperative fl owmetry with assessment of the volume blood circulation (VBC in the hepatic artery (HA was carried out in the both studied groups. Reference value of VBC was 100 ml/min and higher. Before and after reperfusion in the liver biopsy material we performed immunohistochemical study with the use of endothelial marker CD 31 with subsequent morphometric estimation of the specifi c square of the microvascular bloodstream.Results. In both groups there was no change in the specifi c square in the areas of portal tract and central vein before and after restoring blood fl ow. In the second group, an 8 times increase of the specifi c square of sinusoids was observed after restoring blood fl ow (р < 0,01.Conclusion. Intraoperative fl owmetric control of the blood fl ow allows in due time to perform surgical correction of the graft arterial blood supply during OLT, and it reduces the risk of thrombosis up to 0%. The value of VBC in the hepatic artery (HA has reliable dependence upon the state of microcirculatory bloodstream of cadaveric donor’s liver after reperfusion.

  1. Carotid blood flow measured by an ultrasonic volume flowmeter in carotid stenosis and patients with dementia.

    OpenAIRE

    UEMATSU, S.; Folstein, M F

    1985-01-01

    The volume flowmeter is a simple, noninvasive Doppler ultrasound technique that provides accurate measurement of carotid artery diameter and flow. The device provides a useful laboratory test that can aid significantly in diagnosis of carotid stenosis and dementia.

  2. Intraprocedural blood volume measurement using C-arm CT as a predictor for treatment response of malignant liver tumours undergoing repetitive transarterial chemoembolization (TACE)

    International Nuclear Information System (INIS)

    To evaluate feasibility of measuring parenchymal blood volume (PBV) of malignant hepatic tumours using C-arm CT, test the changes in PBV following repeated transarterial chemoembolization (TACE) and correlate these changes with the change in tumour size in MRI. 111 patients with liver malignancy were included. Patients underwent MRI and TACE in a 4- to 6-week interval. During intervention C-arm CT was performed. Images were post-processed to generate PBV maps. Blood volume data in C-arm CT and change in size in MRI were evaluated. The correlation between PBV and size was tested using Spearman rank test. Pre-interventional PBV maps showed a mean blood volume of 84.5 ml/1000 ml ± 62.0, follow-up PBV maps after multiple TACE demonstrated 61.1 ml/1000 ml ± 57.5. The change in PBV was statistically significant (p = 0.02). Patients with initial tumour blood volume >100 ml/1000 ml dropped 7.1 % in size and 47.2 % in blood volume; 50-100 ml/1000 ml dropped 4.6 % in size and 25.7 % in blood volume; and <50 ml/1000 ml decreased 2.8 % in size and increased 82.2 % in blood volume. PBV measurement of malignant liver tumours using C-arm CT is feasible. Following TACE PBV decreased significantly. Patients with low initial PBV show low local response rates and further increase in blood volume, whereas high initial tumour PBV showed better response to TACE. (orig.)

  3. Intraprocedural blood volume measurement using C-arm CT as a predictor for treatment response of malignant liver tumours undergoing repetitive transarterial chemoembolization (TACE)

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, Thomas J.; Schaefer, Patrik; Lehnert, Thomas; Mbalisike, Emmanuel; Hammerstingl, Renate; Eichler, Katrin; Zangos, Stephan [Johann Wolfgang Goethe-University Frankfurt, Institute for Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Nour-Eldin, Nour-Eldin A. [Johann Wolfgang Goethe-University Frankfurt, Institute for Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Cairo University, Department of Radiology, Faculty of Medicine (Kasr Al-Ainy), Cairo (Egypt); Ackermann, Hanns [Johann Wolfgang Goethe-University Frankfurt, Department of Biomedical Statistics, Frankfurt am Main (Germany); Naguib, Nagy N.N. [Johann Wolfgang Goethe-University Frankfurt, Institute for Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Alexandria University, Department of Radiology, Faculty of Medicine, Alexandria (Egypt)

    2016-03-15

    To evaluate feasibility of measuring parenchymal blood volume (PBV) of malignant hepatic tumours using C-arm CT, test the changes in PBV following repeated transarterial chemoembolization (TACE) and correlate these changes with the change in tumour size in MRI. 111 patients with liver malignancy were included. Patients underwent MRI and TACE in a 4- to 6-week interval. During intervention C-arm CT was performed. Images were post-processed to generate PBV maps. Blood volume data in C-arm CT and change in size in MRI were evaluated. The correlation between PBV and size was tested using Spearman rank test. Pre-interventional PBV maps showed a mean blood volume of 84.5 ml/1000 ml ± 62.0, follow-up PBV maps after multiple TACE demonstrated 61.1 ml/1000 ml ± 57.5. The change in PBV was statistically significant (p = 0.02). Patients with initial tumour blood volume >100 ml/1000 ml dropped 7.1 % in size and 47.2 % in blood volume; 50-100 ml/1000 ml dropped 4.6 % in size and 25.7 % in blood volume; and <50 ml/1000 ml decreased 2.8 % in size and increased 82.2 % in blood volume. PBV measurement of malignant liver tumours using C-arm CT is feasible. Following TACE PBV decreased significantly. Patients with low initial PBV show low local response rates and further increase in blood volume, whereas high initial tumour PBV showed better response to TACE. (orig.)

  4. Imaging changes in blood volume and oxygenation in the newborn infant brain using three-dimensional optical tomography

    International Nuclear Information System (INIS)

    Induced haemodynamic and blood oxygenation changes occurring within the brain of a ventilated newborn infant have been imaged in three dimensions using optical tomography. Noninvasive measurements of the flight times of transmitted light were acquired during illumination of the brain by laser pulses at wavelengths of 780 nm and 815 nm. The oxygen and carbon dioxide partial pressures were adjusted through alterations to the ventilator settings, resulting in changes to the cerebral blood volume and oxygenation. Three-dimensional images were generated using the physiologically associated differences in the measured data, obviating the need for data calibration using a separate reference measurement. The results exhibit large changes in absorption coefficient at both wavelengths. Images corresponding to differences in concentrations of oxy- and deoxyhaemoglobin are in qualitative agreement with known physiological data

  5. Spatiotemporal characteristics of cerebral blood volume changes in different microvascular compartments evoked by sciatic nerve stimulation in rat somatosensory cortex

    Science.gov (United States)

    Li, Pengcheng; Luo, Qingming; Luo, Weihua; Chen, Shanbin; Cheng, Haiying; Zeng, Shaoqun

    2003-07-01

    The spatio-temporal characteristics of changes in cerebral blood volume associated with neuronal activity were investigated in the hindlimb somatosensory cortex of α-chloralose/urethan anesthetized rats (n=10) with optical imaging at 570nm through a thinned skull. Activation of cortex was carried out by electrical stimulation of the contralateral sciatic nerve with 5Hz, 0.3V pulses (0.5ms) for duration of 2s. The stimulation evoked a monophasic optical reflectance decrease at cortical parenchyma and arteries sites rapidly after the onset of stimulation, whereas no similar response was observed at vein compartments. The optical signal changes reached 10% of the peak response 0.70+/-0.32s after stimulation onset and no significant time lag in this 10% start latency time was observed between the response at cortical parenchyma and arteries compartments. The evoked optical reflectance decrease reached the peak (0.25%+/-0.047%) 2.66+/-0.61s after the stimulus onset at parenchyma site, 0.40+/-0.20s earlier (P<0.05) than that at arteries site (0.50+/-0.068% 3.06+/-0.70s). Variable location within the cortical parenchyma and arteries compartment themselves didn"t affect the temporal characteristics of the evoked signal significantly. These results suggest that the sciatic nerve stimulation evokes a local blood volume increase at both capillaries (cortical parenchyma) and arterioles rapidly after the stimulus onset but the evoked blood volume increase in capillaries could not be entirely accounted for by the dilation of arterioles.

  6. Anthropometric correlates of blood pressure among school children in Nagpur city, central India: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Deepak Kishanrao Lone

    2014-10-01

    Full Text Available Context: On the basis of emerging evidence, it is now apparent that primary hypertension is detectable in the young and that it occurs commonly. The long-term health risks for hypertensive children and adolescents can be substantial. Early diagnosis of hypertension (HT is an important strategy in its control. Previous studies have documented that hypertension may begin in adolescence, perhaps even in childhood. Aims: To determine the prevalence of hypertension and its correlation with anthropometric variables like height, weight and body mass index (BMI among school-going children in Nagpur city, Central India. Settings and Design: Cross-sectional study done in one randomly selected school. Materials and Methods: School-going children aged between 12 and 16 years were included in the study. The weight and height were measured using a standard procedure. Blood pressure measurements were taken by a mercury sphygmomanometer. Hypertension was diagnosed if blood pressure was more than 95 th percentile for the age and height. The distributions of blood pressure by anthropometric characteristics were studied. Statistical Analysis Used: Mean, standard deviation, correlation coefficient and χ2 test were used for statistical analysis. Results: The overall prevalence of hypertension was found to be 11.77%. Blood pressure of both genders appears to have positive correlation with anthropometric characteristics. Conclusions: Increase in anthropometric measurements like height, weight and BMI were found to be positively correlated with hypertension among school children in the present study.

  7. Simultaneous evaluation of brain tumour metabolism, structure and blood volume using [(18)F]-fluoroethyltyrosine (FET) PET/MRI

    DEFF Research Database (Denmark)

    Henriksen, Otto M; Larsen, Vibeke A; Muhic, Aida; Hansen, Adam E; Larsson, Henrik B W; Poulsen, Hans S; Law, Ian

    2016-01-01

    at least one modality for any pair of modalities. In 56 % of the patients susceptibility artefacts in DSC BV maps overlapped the tumour on MRI. CONCLUSION: The study demonstrated that although tumour volumes determined by BV MRI and FET PET were quantitatively correlated, their spatial congruence in......PURPOSE: Both [(18)F]-fluoroethyltyrosine (FET) PET and blood volume (BV) MRI supplement routine T1-weighted contrast-enhanced MRI in gliomas, but whether the two modalities provide identical or complementary information is unresolved. The aims of the study were to investigate the feasibility of...... simultaneous structural MRI, BV MRI and FET PET of gliomas using an integrated PET/MRI scanner and to assess the spatial and quantitative agreement in tumour imaging between BV MRI and FET PET. METHODS: A total of 32 glioma patients underwent a 20-min static simultaneous PET/MRI acquisition on a Siemens m...

  8. Effect of Buddhist meditation on serum cortisol and total protein levels, blood pressure, pulse rate, lung volume and reaction time.

    Science.gov (United States)

    Sudsuang, R; Chentanez, V; Veluvan, K

    1991-09-01

    Serum cortisol and total protein levels, blood pressure, heart rate, lung volume, and reaction time were studied in 52 males 20-25 years of age practicing Dhammakaya Buddhist meditation, and in 30 males of the same age group not practicing meditation. It was found that after meditation, serum cortisol levels were significantly reduced, serum total protein level significantly increased, and systolic pressure, diastolic pressure and pulse rate significantly reduced. Vital capacity, tidal volume and maximal voluntary ventilation were significantly lower after meditation than before. There were also significant decreases in reaction time after mediation practice. The percentage decrease in reaction time during meditation was 22%, while in subjects untrained in meditation, the percentage decrease was only 7%. Results from these studies indicate that practising Dhammakaya Buddhist meditation produces biochemical and physiological changes and reduces the reaction time. PMID:1801007

  9. Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

    International Nuclear Information System (INIS)

    Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR) can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking complements and provides incremental information compared to particle

  10. Effects on Peripheral and Central Blood Pressure of Cocoa With Natural or High-Dose Theobromine A Randomized, Double-Blind Crossover Trial

    NARCIS (Netherlands)

    B. van den Bogaard; R. Draijer; B.E. Westerhof; A.H. van den Meiracker; G.A. van Montfrans; B.J.H. van den Born

    2010-01-01

    Flavanol-rich cocoa products have been reported to lower blood pressure. It has been suggested that theobromine is partially responsible for this effect. We tested whether consumption of flavanol-rich cocoa drinks with natural or added theobromine could lower peripheral and central blood pressure. I

  11. Effects on peripheral and central blood pressure of cocoa with natural or high-dose theobromine: A randomized, double-blind crossover trial

    NARCIS (Netherlands)

    B. van den Bogaard (Bas); R. Draijer (Richard); B.E. Westerhof (Berend); A.H. van den Meiracker (Anton); G.A. van Montfrans (Gert); B.J.H. van den Born

    2010-01-01

    textabstractFlavanol-rich cocoa products have been reported to lower blood pressure. It has been suggested that theobromine is partially responsible for this effect. We tested whether consumption of flavanol-rich cocoa drinks with natural or added theobromine could lower peripheral and central blood

  12. Comparative evaluation of cerebral blood volume and cerebral blood flow in acute ischemic stroke by using perfusion-weighted MR imaging and SPECT

    International Nuclear Information System (INIS)

    Purpose: To investigate the relationship between relative cerebral blood volume (CBV) measured with perfusion-weighted (PW) MR imaging and relative cerebral blood flow (CBF) measured with SPECT in acute ischemic stroke. Material and Methods: Fifteen patients who had acute unilateral middle cerebral artery occlusion underwent both PW MR imaging and 99mTc-HMPAO SPECT with an interval less than 20 minutes between the two examinations within 6 hours after stroke onset. Lesion-to-contralateral relative CBV and CBF ratios measured in multiple regions of interest were compared to evaluate the relationship of the two parameters. Results: An overall linear relationship was found between relative CBV and relative CBF ratios (R2=0.54, p0.05). Regions with evolving infarction had more severe hypoperfusion (mean relative CBF ratio, 0.38±0.22) than regions without (mean relative CBF ratio, 0.70±0.13) (p<0.0001). Conclusion: A significant linear relationship existed between relative CBV and relative CBF in acute ischemic stroke, although relative CBV did not change linearly to relative CBF in mild hypoperfusion. Relative CBV can be used as an alternative to relative CBF within 6 hours after stroke onset, particularly in regions with severe hypoperfusion proceeding to infarction

  13. Elevated HbA1c Levels Are Associated with the Blunted Autonomic Response Assessed by Heart Rate Variability during Blood Volume Reduction.

    Science.gov (United States)

    Kamakura, Miho; Maruyama, Ryoko

    2016-01-01

    A high glycemic status increases the risk for autonomic dysfunction and cardiovascular failure. The aim of this study was to investigate time-dependent changes in the autonomic response and cardiovascular dynamics and the association between the level of hemoglobin A1c (HbA1c) and autonomic response during blood volume reduction. The study population consisted of 26 preoperative participants who were scheduled for autologous blood donation (200-400 mL of whole blood) for intraoperative or postoperative use. These participants without circulatory, respiratory, or brain disease and diabetes mellitus were grouped according to their HbA1c levels: rate variability (HRV) to quantify cardiac autonomic regulation throughout blood donation. During blood volume reduction, which was about 10% of the circulating blood volume, the BP and heart rate varied within normal ranges in both groups. The high-frequency (HF) component, an index of parasympathetic nerve activity, and the ratio of low-frequency (LF) to HF components (LF/HF), an index of sympathetic nerve activity, significantly decreased and increased with the progression of blood volume reduction, respectively, in the HbA1c < 6.5% group. In contrast, in the HbA1c ≥ 6.5% group, the HF component did not significantly change, and the increase in the LF/HF ratio was delayed. Time-dependent changes in HRV were related to blood volume reduction only in the HbA1c < 6.5% group. Thus, elevated HbA1c levels are associated with the decrease in the autonomic response induced by blood volume reduction. PMID:27615262

  14. Comparison of blood volume pulse and skin conductance responses to mental and affective stimuli at different anatomical sites

    International Nuclear Information System (INIS)

    Measurements of blood volume pulse (BVP) and skin conductance are commonly used as indications of psychological arousal in affective computing and human–machine interfaces. To date, palmar surfaces remain the primary site for these measurements. Placement of sensors on palmar surfaces, however, is undesirable when recordings are fraught with motion and pressure artifacts. These artifacts are frequent when the human participant has involuntary movements as in hyperkinetic cerebral palsy. This motivates the use of alternative measurement sites. The present study examined the correlation between measurements of blood volume pulse and skin conductance obtained from three different sites on the body (fingers, toes and ear for BVP; fingers, toes and arch of the foot for skin conductance) in response to cognitive and affective stimuli. The results of this pilot study indicated significant inter-site correlation among signal features derived from different sites, with the exception of BVP amplitude, the number of electrodermal reactions and the slope of the electrodermal activity response. We attribute these differences in part to inter-site discrepancies in local skin conditions, such as skin temperature. Despite these differences, significant changes from baseline were present in the responses to the cognitive and affective stimuli at non-palmar sites, suggesting that these sites may provide viable signal measurements for use in affective computing and human–machine interface applications

  15. Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure

    International Nuclear Information System (INIS)

    A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s−1 and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P < 0.0001). At all cuff pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P < 0.05). At 40 mmHg cuff pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures

  16. Macrophages regulate salt-dependent volume and blood pressure by a vascular endothelial growth factor-C-dependent buffering mechanism.

    Science.gov (United States)

    Machnik, Agnes; Neuhofer, Wolfgang; Jantsch, Jonathan; Dahlmann, Anke; Tammela, Tuomas; Machura, Katharina; Park, Joon-Keun; Beck, Franz-Xaver; Müller, Dominik N; Derer, Wolfgang; Goss, Jennifer; Ziomber, Agata; Dietsch, Peter; Wagner, Hubertus; van Rooijen, Nico; Kurtz, Armin; Hilgers, Karl F; Alitalo, Kari; Eckardt, Kai-Uwe; Luft, Friedrich C; Kerjaschki, Dontscho; Titze, Jens

    2009-05-01

    In salt-sensitive hypertension, the accumulation of Na(+) in tissue has been presumed to be accompanied by a commensurate retention of water to maintain the isotonicity of body fluids. We show here that a high-salt diet (HSD) in rats leads to interstitial hypertonic Na(+) accumulation in skin, resulting in increased density and hyperplasia of the lymphcapillary network. The mechanisms underlying these effects on lymphatics involve activation of tonicity-responsive enhancer binding protein (TonEBP) in mononuclear phagocyte system (MPS) cells infiltrating the interstitium of the skin. TonEBP binds the promoter of the gene encoding vascular endothelial growth factor-C (VEGF-C, encoded by Vegfc) and causes VEGF-C secretion by macrophages. MPS cell depletion or VEGF-C trapping by soluble VEGF receptor-3 blocks VEGF-C signaling, augments interstitial hypertonic volume retention, decreases endothelial nitric oxide synthase expression and elevates blood pressure in response to HSD. Our data show that TonEBP-VEGF-C signaling in MPS cells is a major determinant of extracellular volume and blood pressure homeostasis and identify VEGFC as an osmosensitive, hypertonicity-driven gene intimately involved in salt-induced hypertension. PMID:19412173

  17. Predictors of high central blood pressure in young with isolated systolic hypertension

    OpenAIRE

    Radchenko, Ganna; Torbas,Olena; Sirenko, Yuriy

    2016-01-01

    G D Radchenko, O O Torbas, Yu M Sirenko State Institute National Scientific Center, M.D. Strazhesko Institute of Cardiology, National Academy of Medical Science, Kyiv, Ukraine Objective: According to the European Society of Cardiology/European Society of Hypertension 2013 guidelines, evaluation of aortic blood pressure (BP) is needed in young with isolated systolic hypertension (ISH), but using special devices is not common, especially in Ukraine, where only a few centers ha...

  18. Does caval aorta index correlate with central venous pressure in intravascular volume assessment in patients undergoing endoscopic transuretheral resection of prostate?

    Directory of Open Access Journals (Sweden)

    G F El-Baradey

    2016-01-01

    Full Text Available Background and Objective: Ultrasonography has been suggested as a useful noninvasive tool for intravascular volume assessment in critically ill-patients. Fluid absorption is an inevitable complication of transurethral resection of the prostate (TURP. However, there are few data comparing the caval aortic index with central venous pressure (CVP measurement for intravascular volume assessment in patients undergoing TURP. Materials and Methods: This is a prospective observer blinded study carried out on 50 patients who underwent elective TURP. The primary outcome measure of our study was the correlation of the caval aorta (Ao index with CVP, and the secondary outcome measures were the sensitivity and specificity of the caval Ao index. Results: There was a positive correlation of inferior vena cava/Ao (IVC/Ao index to CVP (R = 0.9 and significant P = 0.001FNx01. The sensitivity and specificity of the IVC/Ao index were measured to predict the CVP. A CVP ≤7 cm H 2 O correlated with IVC/Ao index 0.8 ± 0.3 mean ± standard deviation (SD (sensitivity 0.93, specificity 0.66, a CVP of 8-12 cm H 2 O correlated with IVC/Ao index 1.5 ± 0.2 mean ± SD (sensitivity 0.96, specificity 0.42, and a CVP >12 cm H 2 O correlated with IVC/Ao index 1.8 ± 0.07 mean ± SD (sensitivity 0.93, specificity 0.58. Conclusion: Sonographic caval Ao index is useful for the evaluation of preoperative and intraoperative volume status, especially in major surgeries with marked fluid shift or blood loss and had the advantage of being noninvasive, safe, quick, and easy technique with no complications.

  19. Association between cell-bound blood amyloid-β(1–40) levels and hippocampus volume

    OpenAIRE

    Sotolongo-Grau, Oscar; Pesini, Pedro; Valero, Sergi; Lafuente, Asunción; Buendía, Mar; Pérez-Grijalba, Virginia; José, Itziar San; Ibarria, Marta; Tejero, Miguel A; Giménez, Joan; Hernández, Isabel; Tárraga, Lluís; Ruiz, Agustín; Boada, Mercé; Sarasa, Manuel

    2014-01-01

    Introduction The identification of early, preferably presymptomatic, biomarkers and true etiologic factors for Alzheimer’s disease (AD) is the first step toward establishing effective primary and secondary prevention programs. Consequently, the search for a relatively inexpensive and harmless biomarker for AD continues. Despite intensive research worldwide, to date there is no definitive plasma or blood biomarker indicating high or low risk of conversion to AD. Methods Magnetic resonance imag...

  20. Model estimation of cerebral hemodynamics between blood flow and volume changes: a data-based modeling approach.

    Science.gov (United States)

    Wei, Hua-Liang; Zheng, Ying; Pan, Yi; Coca, Daniel; Li, Liang-Min; Mayhew, J E W; Billings, Stephen A

    2009-06-01

    It is well known that there is a dynamic relationship between cerebral blood flow (CBF) and cerebral blood volume (CBV). With increasing applications of functional MRI, where the blood oxygen-level-dependent signals are recorded, the understanding and accurate modeling of the hemodynamic relationship between CBF and CBV becomes increasingly important. This study presents an empirical and data-based modeling framework for model identification from CBF and CBV experimental data. It is shown that the relationship between the changes in CBF and CBV can be described using a parsimonious autoregressive with exogenous input model structure. It is observed that neither the ordinary least-squares (LS) method nor the classical total least-squares (TLS) method can produce accurate estimates from the original noisy CBF and CBV data. A regularized total least-squares (RTLS) method is thus introduced and extended to solve such an error-in-the-variables problem. Quantitative results show that the RTLS method works very well on the noisy CBF and CBV data. Finally, a combination of RTLS with a filtering method can lead to a parsimonious but very effective model that can characterize the relationship between the changes in CBF and CBV. PMID:19174333

  1. Combined cycle solar central receiver hybrid power system study. Volume III. Appendices. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    A design study for a 100 MW gas turbine/steam turbine combined cycle solar/fossil-fuel hybrid power plant is presented. This volume contains the appendices: (a) preconceptual design data; (b) market potential analysis methodology; (c) parametric analysis methodology; (d) EPGS systems description; (e) commercial-scale solar hybrid power system assessment; and (f) conceptual design data lists. (WHK)

  2. North Central Regional geologic characterization report. Volume 2. Plates. Final report

    International Nuclear Information System (INIS)

    Volume 8(2) contains the following maps: Geologic map of the Lake Superior Region (Minnesota, Wisconsin, and northern Michigan); Index Map; Overburden Thickness; Faults and Ground Acceleration; Rock and Mineral Resources; Ground Water Basins and Potential Major Discharge Zones; and Ground Water Resource Potential

  3. A Central Limit Theorem for the Volumes of High Excursions of Stationary Associated Random Fields

    Directory of Open Access Journals (Sweden)

    Vadim Demichev

    2015-05-01

    Full Text Available We prove that under certain conditions the excursion sets volumes of stationary positively associated random fields converge after rescaling to the normal distribution as the excursion level and the size of the observation window grow. In addition, we provide a number of examples.

  4. Effects of CO2 pneumoperitoneum on blood flow vol-ume of abdominal organs of rabbits with controlled hem-orrhagic shock and liver impact injuries

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lian-yang; ZHAO Song; LI Yong; MA Xiao-lin

    2009-01-01

    Objective: To investigate the effects of CO2 pneumo-peritoneum on blood flow volume of abdominal organs of rabbits with controlled hemorrhagic shock model and liver impact injuries.Methods: After controlled hemorrhagic shock and liver impact injuries, the rabbit model was established. Eighteen rabbits subjected to hemorrhagic shock and liver impact inju-ries were divided into 3 groups randomly according to the volume of lost blood: light hemorrhagic shock (blood loss volume was 10%, 6 ml/kg), moderate hemorrhagic shock (20%, 12 ml/kg) and severe hemorrhagic shock (40%, 22 ml/kg). Intraabdominal pressures of CO2 pneumoperitoneum was 10 mmHg. Color-labeled microspheres were used to mea-sure the blood flow volume of the liver, kidney and stomach before pneumoperitoneum at 30 minutes and 2 hours after pneumoperitoneum and 30 minutes after deflation. And the mortality and hepatic traumatic condition of rabbits were recorded.Results: Of the 18 rabbits, there were 9 with liver impact injuries at Grade Ⅰ, 8 at Grade Ⅱ and Ⅰ at Grade Ⅲ (according to AIS-2005). The mortality rate in light hemorrhagic shock group was 33.33%, and that in moderate or severe hemor-rhagic shock group was 100% within 30 minutes and 2 hours after pneumoperitoneum, respectively. The blood flow vol-ume in the organs detected decreased at 30 minutes under pneumoperitoneum in light and moderate hemorrhagic shock groups. At the same time, the blood flow volume of the liver in moderate hemorrhagic shock group decreased more sig-nificantly than that in light hemorrhagic shock group.Conclusions: The blood flow volume of abdominal organs in rabbits is decreased obviously under CO2 pneumoperitoneum, with fairly high mortality rate. It is be-lieved that CO2 pneumoperitoneum should cautiously be used in abdominal injury accompanied with hemorrhagic shock, especially under non-resuscitation conditions.

  5. High prevalence of anti-hepatitis E virus antibodies among blood donors in central Italy, February to March 2014.

    Science.gov (United States)

    Lucarelli, Claudia; Spada, Enea; Taliani, Gloria; Chionne, Paola; Madonna, Elisabetta; Marcantonio, Cinzia; Pezzotti, Patrizio; Bruni, Roberto; La Rosa, Giuseppina; Pisani, Giulio; Dell'Orso, Luigi; Ragone, Katia; Tomei, Carla; Ciccaglione, Anna Rita

    2016-07-28

    Prevalence of anti-hepatitis E virus (HEV) antibodies is highly variable in developed countries, which seems partly due to differences in assay sensitivity. Using validated sensitive assays, we tested 313 blood donors attending a hospital transfusion unit in central Italy in January and February 2014 for anti-HEV IgG and IgM and HEV RNA. Data on HEV exposure were collected from all donors. Overall anti-HEV IgG prevalence was 49% (153/313). Eating raw dried pig-liver sausage was the only independent predictor of HEV infection (adjusted prevalence rate ratio = 2.14; 95% confidence interval: 1.23-3.74). Three donors were positive for either anti-HEV IgM (n = 2; 0.6%) or HEV RNA (n = 2; 0.6%); they were completely asymptomatic, without alanine aminotransferase (ALT) abnormalities. Of the two HEV RNA-positive donors (both harbouring genotype 3), one was anti-HEV IgG- and IgM-positive, the other was anti-HEV IgG- and IgM-negative. The third donor was positive for anti-HEV IgG and IgM but HEV RNA-negative. HEV infection is therefore hyperendemic among blood donors (80% men 18-64 years-old) from central Italy and associated with local dietary habits. Nearly 1% of donors have acute or recent infection, implying potential transmission to blood recipients. Neither ALT nor anti-HEV IgM testing seems useful to prevent transfusion-transmitted HEV infection. PMID:27494608

  6. Impedance cardiography: Pulsatile blood flow and the biophysical and electrodynamic basis for the stroke volume equations

    OpenAIRE

    Bernstein, Donald P.

    2010-01-01

    Impedance cardiography (ICG) is a branch of bioimpedance pimarily concerned with the determination of left ventricular stroke volume (SV). As implemented, using the transthoracic approach, the technique involves applying a current field longitudinally across a segment of thorax by means of a constant magnitude, high frequency, low amplitude alternating current (AC). By Ohm's Law, the voltage difference measured within the current field is proportional to the electrical impedance Z (&Omega...

  7. Initial study of 3D perfused blood volume imaging using 64-detector CT in hyperacute cerebral infarction

    International Nuclear Information System (INIS)

    Objective: To evaluate the value of three dimensional CT whole brain perfused blood volume (3D-PBV) based on CTA row data in hyperacute cerebral infarction. Methods: 38 patients with stroke within 12 hours performed plain CT and CTA scans. 3D software Neuro PBV was applied to process the CTA row data and 3D-PBV of brain was obtained. MR examinations were performed within 2 hours after CT scans. The numbers of ischemic lesions on plain CT, 3D-PBV and MRI-DWI were recorded. The volumes of ischemic lesions on 3D-PBV and MR -DWI were measured. Results: In 38 patients, the number of infarct lesion detected by MRI-DWI, PBV, and plain CT was 45, 41, and 16 respectively. Kappa test showed a substantial agreement (κ=0.78) between 3D-PBV and MRI-DWI in detecting ischemic lesions. The detectability of plain CT showed fair or slight agreements to 3D-PBV and MR-DWI (κ=0.24, 0.18, respectively). The lesion volumes did not differ on 3D-PBV and MR-DWI (t=7.249, P>0.05). Conclusion: 3D-PBV combined with CTA can detect ischemic lesion and evaluate perfusion. It had important value in diagnosing hyperacute cerebral infarction. (authors)

  8. Higher blood volumes improve the sensitivity of direct PCR diagnosis of blood stream tuberculosis among HIV-positive patients: an observation study

    OpenAIRE

    Bwanga, Freddie; Disqué, Claudia; Lorenz, Michael G.; Allerheiligen, Vera; Worodria, William; Luyombya, Allan; Najjingo, Irene; Weizenegger, Michael

    2015-01-01

    Background Blood stream tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB) is common among HIV-positive patients, turning rapidly fatal unless detected and treated promptly. Blood culture is currently the standard test for the detection of MTB in whole blood but results take weeks; patients deteriorate markedly and often die before a diagnosis of blood stream TB is made. Rapid molecular tests on whole blood, with potential for same day diagnosis of blood stream TB usually show low ...

  9. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume II. Plant specifications

    Energy Technology Data Exchange (ETDEWEB)

    Price, R. E.

    1983-12-31

    The specifications and design criteria for all plant systems and subsystems used in developing the preliminary design of Carrisa Plains 30-MWe Solar Plant are contained in this volume. The specifications have been organized according to plant systems and levels. The levels are arranged in tiers. Starting at the top tier and proceeding down, the specification levels are the plant, system, subsystem, components, and fabrication. A tab number, listed in the index, has been assigned each document to facilitate document location.

  10. Imaging transient blood vessel fusion events in zebrafish by correlative volume electron microscopy.

    Directory of Open Access Journals (Sweden)

    Hannah E J Armer

    Full Text Available The study of biological processes has become increasingly reliant on obtaining high-resolution spatial and temporal data through imaging techniques. As researchers demand molecular resolution of cellular events in the context of whole organisms, correlation of non-invasive live-organism imaging with electron microscopy in complex three-dimensional samples becomes critical. The developing blood vessels of vertebrates form a highly complex network which cannot be imaged at high resolution using traditional methods. Here we show that the point of fusion between growing blood vessels of transgenic zebrafish, identified in live confocal microscopy, can subsequently be traced through the structure of the organism using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM and Serial Block Face/Scanning Electron Microscopy (SBF/SEM. The resulting data give unprecedented microanatomical detail of the zebrafish and, for the first time, allow visualization of the ultrastructure of a time-limited biological event within the context of a whole organism.

  11. Central and peripheral venous lines-associated blood stream infections in the critically ill surgical patients

    Directory of Open Access Journals (Sweden)

    Ugas Mohamed

    2012-09-01

    Full Text Available Abstract Critically ill surgical patients are always at increased risk of actual or potentially life-threatening health complications. Central/peripheral venous lines form a key part of their care. We review the current evidence on incidence of central and peripheral venous catheter-related bloodstream infections in critically ill surgical patients, and outline pathways for prevention and intervention. An extensive systematic electronic search was carried out on the relevant databases. Articles were considered suitable for inclusion if they investigated catheter colonisation and catheter-related bloodstream infection. Two independent reviewers engaged in selecting the appropriate articles in line with our protocol retrieved 8 articles published from 1999 to 2011. Outcomes on CVC colonisation and infections were investigated in six studies; four of which were prospective cohort studies, one prospective longitudinal study and one retrospective cohort study. Outcomes relating only to PICCs were reported in one prospective randomised trial. We identified only one study that compared CVC- and PICC-related complications in surgical intensive care units. Although our search protocol may not have yielded an exhaustive list we have identified a key deficiency in the literature, namely a paucity of studies investigating the incidence of CVC- and PICC-related bloodstream infection in exclusively critically ill surgical populations. In summary, the diverse definitions for the diagnosis of central and peripheral venous catheter-related bloodstream infections along with the vastly different sample size and extremely small PICC population size has, predictably, yielded inconsistent findings. Our current understanding is still limited; the studies we have identified do point us towards some tentative understanding that the CVC/PICC performance remains inconclusive.

  12. Solar Central Receiver Prototype Heliostat. Volume II. Phase II planning (preliminary)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    A currently planned DOE program will develop and construct a 10 MW/sub e/ Pilot Plant to demonstrate the feasibility and operational characteristics of Solar Central Receiver Power Generation. The field of heliostats is a major element of the Solar Central Receiver Power Generation system. The primary objective of the program described is to establish and verify the manufacturability, performance, durability, and maintenance requirements of the commercial plant heliostat design. End products of the 16 month effort include: (1) design, fabrication, and test of heliostats; (2) preliminary designs of manufacturing, assembly, installation, and maintenance processes for quantity production; (3) detailed design of critical tooling or other special equipment for such processes; (4) refined cost estimates for heliostats and maintenance; and (5) an updated commercial plant heliostat preliminary design. The program management and control system is discussed. (WHK)

  13. Blood Pressure Quiz

    Science.gov (United States)

    ... page please turn Javascript on. Feature: High Blood Pressure Blood Pressure Quiz Past Issues / Fall 2011 Table of Contents ... About High Blood Pressure / Treatment: Types of Blood Pressure Medications / Blood Pressure Quiz Fall 2011 Issue: Volume 6 Number ...

  14. Dynamic contrast-enhanced MRI assessment of hyperemic fractional microvascular blood plasma volume in peripheral arterial disease: initial findings.

    Directory of Open Access Journals (Sweden)

    Bas Versluis

    Full Text Available OBJECTIVES: The aim of the current study was to describe a method that assesses the hyperemic microvascular blood plasma volume of the calf musculature. The reversibly albumin binding contrast agent gadofosveset was used in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI to assess the microvascular status in patients with peripheral arterial disease (PAD and healthy controls. In addition, the reproducibility of this method in healthy controls was determined. MATERIALS AND METHODS: Ten PAD patients with intermittent claudication and 10 healthy control subjects were included. Patients underwent contrast-enhanced MR angiography of the peripheral arteries, followed by one DCE MRI examination of the musculature of the calf. Healthy control subjects were examined twice on different days to determine normative values and the interreader and interscan reproducibility of the technique. The MRI protocol comprised dynamic imaging of contrast agent wash-in under reactive hyperemia conditions of the calf musculature. Using pharmacokinetic modeling the hyperemic fractional microvascular blood plasma volume (V(p, unit: % of the anterior tibial, gastrocnemius and soleus muscles was calculated. RESULTS: V(p was significantly lower for all muscle groups in PAD patients (4.3±1.6%, 5.0±3.3% and 6.1±3.6% for anterior tibial, gastrocnemius and soleus muscles, respectively compared to healthy control subjects (9.1±2.0%, 8.9±1.9% and 9.3±2.1%. Differences in V(p between muscle groups were not significant. The coefficient of variation of V(p varied from 10-14% and 11-16% at interscan and interreader level, respectively. CONCLUSIONS: Using DCE MRI after contrast-enhanced MR angiography with gadofosveset enables reproducible assessment of hyperemic fractional microvascular blood plasma volume of the calf musculature. V(p was lower in PAD patients than in healthy controls, which reflects a promising functional (hemodynamic biomarker for the

  15. National hydroelectric power resources study. Preliminary inventory of hydropower resources. Volume 4. Lake Central region

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-07-01

    The estimates of existing, incremental and the undeveloped hydropower potential for all states in the various regions of the country are presented. In the Lake Central region, the maximum physical potential for all sites exceeds 26,000 MW with an estimated average annual energy of more than 75,000 GWH. By comparison, these values represent about 5% of both the total potential capacity and hydroelectric energy estimated for the entire US. Of the total capacity estimated for the region, 2600 MW has been installed. The remainder (23,600 MW) is the maximum which could be developed by upgrading and expanding existing projects (15,800 MW), and by installing new hydroelectric power capacity at all potentially feasible, undeveloped sites (7800 MW). Small-scale facilities account for some 24% of the region's total installed capacity, but another 900 MW could be added to these and other small water-resource projects. In addition, 900 MW could be installed at potentially feasible, undeveloped small-scale sites. The small-scale resource varies considerably, with the states of Michigan and Wisconsin having the largest potential for incremental development at existing projects in the Lake Central region. This Lake Central region is composed of Minnesota, Wisconsin, Michigan, Ohio, Indiana, Illinois, Kentucky, Missouri, and Iowa.

  16. 每搏量变异度与患者血容量变化的相关性%Correlation between stroke volume variation and blood volume

    Institute of Scientific and Technical Information of China (English)

    王合梅; 贾慧群; 雍芳芳; 李超; 王勇; 赵伟

    2010-01-01

    Objective To evaluate the correlation between stroke volume variation (SVV) and the blood volume. Methods Forty-eight ASA Ⅱ male patients, aged 50-60 yr, scheduled for elective radical operation for gastric cancer, were studied. Anesthesia was induced with fentanyl 4 μg/kg, propofol 2 mg/kg and cis-atracurium 0.15 mg/kg and maintained with inhalation of 2%-3% sevoflurane. 6% HES 130/0.4 was infused intravenously at a rate of 0.67 ml· kg - 1 · min - 1 30 min after induction. SVV,cardiac output (CO),SV and cardiac index (CI) were monitored and recorded using the FloTrac/Vigileo (Edwards Lifesciences, USA) system before HES was infused and when the dose of HES reached 2, 4, 6, 8, 10, 12, 14, 16 and 18 ml/kg. CVP was also recorded at the corresponding time points. Spearman's rank sum correlation coefficient was used to analyze the data. Results Correlation coefficients between the amount of HES infused and CO, SV, CI or CVP were rSVV = - 0.91 ± 0.06,rCO = 0.83 ± 0.04, rSV = 0.86 ± 0.09, rCI = 0.86 ± 0.09 and rCVP = 0.90 ± 0.03. Among the 5 correlation coefficients, rSVV was the highest, rCVP was significantly higher than rCO, rSV and rCI (P < 0.05), and there was no significant difference among rCO, rSV and r CI (P > 0. 05). Conclusion SVV is highly correlated with the blood volume and can be used to guide volume therapy.%目的 评价每搏量变异度(SVV)与患者血容量变化的相关性.方法 择期胃癌根治术男性患者48例,年龄50~60岁,ASA分级Ⅱ级.麻醉诱导后30 min静脉输注6%羟乙基淀粉130/0.40.67 ml·kg-1·min-1,分别于输注前、输注羟乙基淀粉剂量达2、4、6、8、10、12、14、16、18 ml/kg时,记录SVV、CO、SV、CI和CVP.SVV、CO、SV、CI和CVP与羟乙基淀粉输注量行Spearman等级相关分析.结果 SVV、CO、SV、CI和CVP与羟乙基淀粉输注量之间的相关系数分别为:rSVV=-0.91±0.06,rCO=0.83±0.04,rSV=0.86±0.09,rCI=0.86±0.09,rCVP=0.90±0.03.5个相关系数中,rSVV最高,r

  17. Interaction of central Angiotensin II and estrogen on systolic blood pressure in female DOCA-salt treated rats

    Science.gov (United States)

    Kafami, Marzieh; Hosseini, Mahmoud; Niazmand, Saeed; Hadjzadeh, Mousa Alreza; Farrokhi, Esmaeil; Mazloum, Tahereh; Shafei, Mohammad Naser

    2016-01-01

    Background: There is a probable interaction of central angiotensin II (Ang II) and estrogen (Est) on blood pressure in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Therefore, in the present study, the interaction between Ang II and Est in ovariectomized (Ovx) and Sham rats that were treated with DOCA- salt was evaluated. Materials and Methods: The female rats were divided into 10 groups as follows: Sham, Ovx, Sham-DOCA, Ovx-DOCA, Sham-DOCA-estrogen (E), Ovx DOCA-E, Sham-DOCA-losartan (L), Ovx-DOCA-L, Sham–DOCA-L-E, and Ovx-DOCA-L-E. The Est groups received estradiol valerate (2 mg/kg; daily; subcutaneously (s.c)) for four weeks. Following that, several doses of Ang II (0.5, 5, 50, 500, 5000 ng/5 μl) were injected via the intracerebroventricular (i.c.v) route and the changes in systolic blood pressure (SBP) were evaluated. In the losartan groups, 200 μg losartan was injected (i.c.v) 15 minutes after the Ang II injection and the blood pressure was recorded. Treatment by DOCA was performed by removal of one kidney, injection of DOCA (45 mg/kg i.p), and adding of sodium chloride (NaCl) (1%) and potassium chloride (KCl) (0.1%) in the drinking water. Results: The SBP was increased by Ang II and this effect in DOCA-salt treated rat was higher than in the untreated groups. The effect of Ang II on SBP in groups that were treated with Est and L was lower than that in the DOCA-salt groups. Increase in SBP was strongly attenuated by Ang II in groups that were co-treated with both Est and L compared to the DOCA-treated rats. These results showed that Est significantly attenuated the effect of central Ang II on SBP in the DOCA-salt treated rats. Conclusion: We suggest that there are interactions between E and Ang II in the control of blood pressure in DOCA-salt treated rats. PMID:27195251

  18. Factors affecting the lung perfused blood volume in patients with intrapulmonary clots after anti-coagulation therapy

    International Nuclear Information System (INIS)

    Highlights: • Dual-energy CT can provide morphological and functional lung images in the same examination. • The subsequent dual-energy CT demonstrates the increased whole lung perfused blood volume (V120) despite the residual intrapulmonary clots after treatment in one examination. • The increased whole lung perfusion (V120) and a decreased low perfusion volume (V5) result in the improvement in the low perfusion rate (%V5) in the patients with acute pulmonary embolism after treatment. - Abstract: Objectives: Factors affecting the improvement in the lung perfused blood volume (LPBV) were evaluated based on the presence of intrapulmonary clots (IPCs) after anti-coagulation therapy using 64-slice dual-energy CT. Materials and methods: 96 patients exhibiting venous thromboembolism underwent initial and repeated LPBV examinations between December 2008 and July 2014. Fifteen patients were excluded due to pulmonary comorbidities, and a total of 81 patients were included in this study. Acute pulmonary embolism (PE) was diagnosed in 46 of the patients (56.7%). LPBV images were three-dimensionally reconstructed with two threshold ranges: 1–120 HU (V120) and 1–5 HU (V5), and the relative value of V5 per V120 expressed as %V5. These values were subsequently compared with indicators of the severity of PE, such as the D-dimer level, heart rate and CT measurements. This study was approved by the local ethics committee. Results: In patients with IPCs, the D-dimer, V5 and %V5values were significantly larger (p ≤ 0.01) in the initial LPBV, although these differences disappeared in subsequent LPBV after treatment. The right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio and %V5 values were also significantly reduced, whereas the V5 value did not significantly decrease (p = 0.07), but V120 value significantly increased (p < 0.001) after treatment. However, in patients with IPCs the change rate in %V5 [(subsequent-initial)/initial %V5] showed a

  19. Factors affecting the lung perfused blood volume in patients with intrapulmonary clots after anti-coagulation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Masuda, Yu [4th Grade of 6-year Medicine Doctor Program, Department of Medicine, Yamaguchi University Faculty of Medicine and Health Sciences 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru [Department of Radiology, Yamaguchi Grand Medical Center, Oosaki 77, Hofu, Yamaguchi 747-8511 (Japan); Nomura, Takafumi; Nakao, Sei [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Suga, Kazuyoshi [Department of Radiology, St Hills Hospital, Imamurakita 3-7-18, Ube, Yamaguchi 755-0155 (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan); Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan)

    2015-08-15

    Highlights: • Dual-energy CT can provide morphological and functional lung images in the same examination. • The subsequent dual-energy CT demonstrates the increased whole lung perfused blood volume (V{sub 120}) despite the residual intrapulmonary clots after treatment in one examination. • The increased whole lung perfusion (V{sub 120}) and a decreased low perfusion volume (V{sub 5}) result in the improvement in the low perfusion rate (%V{sub 5}) in the patients with acute pulmonary embolism after treatment. - Abstract: Objectives: Factors affecting the improvement in the lung perfused blood volume (LPBV) were evaluated based on the presence of intrapulmonary clots (IPCs) after anti-coagulation therapy using 64-slice dual-energy CT. Materials and methods: 96 patients exhibiting venous thromboembolism underwent initial and repeated LPBV examinations between December 2008 and July 2014. Fifteen patients were excluded due to pulmonary comorbidities, and a total of 81 patients were included in this study. Acute pulmonary embolism (PE) was diagnosed in 46 of the patients (56.7%). LPBV images were three-dimensionally reconstructed with two threshold ranges: 1–120 HU (V{sub 120}) and 1–5 HU (V{sub 5}), and the relative value of V{sub 5} per V{sub 120} expressed as %V{sub 5}. These values were subsequently compared with indicators of the severity of PE, such as the D-dimer level, heart rate and CT measurements. This study was approved by the local ethics committee. Results: In patients with IPCs, the D-dimer, V{sub 5} and %V{sub 5}values were significantly larger (p ≤ 0.01) in the initial LPBV, although these differences disappeared in subsequent LPBV after treatment. The right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio and %V{sub 5} values were also significantly reduced, whereas the V{sub 5} value did not significantly decrease (p = 0.07), but V{sub 120} value significantly increased (p < 0.001) after treatment. However, in

  20. Blood characteristics, tracheal volume and heart mass of burrowing owls (Athene cunicularia) and bobwhite (Colinus virginianus).

    Science.gov (United States)

    Boggs, D F; Birchard, G F; Kilgore, D L

    1983-01-01

    1. Measurements of certain hematological and morphological characteristics were made in burrowing owls and bobwhite in search of features that could be associated with the previously described ventilatory adaptations of the burrowing owl to hypoxia and hypercarbia. 2. Values for burrowing owls and bobwhite, respectively, were: P50 = 44.9, 46.0 torr; Hct = 36.6, 38.8 vol%, Hb = 12, 12.3 (g/100 ml); RBC = 2.72 X 10(6), 3.02 X 10(6); log P50/pH = -0.412, -0.485; delta log PCO2/delta pH = -1.39, -1.585. 3. The owls had greater heart weights and smaller tracheal volumes than the bobwhite or the predicted value. 4. No hematological characteristics of the burrowing bird distinguish it from the non-burrowing bird. PMID:6132713

  1. Hypercoagulability in response to elevated body temperature and central hypovolemia

    DEFF Research Database (Denmark)

    Meyer, Martin; Ostrowski, Sisse R; Overgaard, Flemming Anders;

    2013-01-01

    Coagulation abnormalities contribute to poor outcomes in critically ill patients. In trauma patients exposed to a hot environment, a systemic inflammatory response syndrome, elevated body temperature, and reduced central blood volume occur in parallel with changes in hemostasis and endothelial...

  2. Acanthamoeba produces disseminated infection in locusts and traverses the locust blood-brain barrier to invade the central nervous system

    Directory of Open Access Journals (Sweden)

    Kirk Ruth

    2010-07-01

    Full Text Available Abstract Background Many aspects of Acanthamoeba granulomatous encephalitis remain poorly understood, including host susceptibility and chronic colonization which represent important features of the spectrum of host-pathogen interactions. Previous studies have suggested locusts as a tractable model in which to study Acanthamoeba pathogenesis. Here we determined the mode of parasite invasion of the central nervous system (CNS. Results Using Acanthamoeba isolates belonging to the T1 and T4 genotypes, the findings revealed that amoebae induced sickness behaviour in locusts, as evidenced by reduced faecal output and weight loss and, eventually, leading to 100% mortality. Significant degenerative changes of various tissues were observed by histological sectioning. Both isolates produced disseminated infection, with viable amoebae being recovered from various tissues. Histological examination of the CNS showed that Acanthamoeba invaded the locust CNS, and this is associated with disruption of the perineurium cell/glial cell complex, which constitutes the locust blood-brain barrier. Conclusions This is the first study to demonstrate that Acanthamoeba invades locust brain by modulating the integrity of the insect's blood-brain barrier, a finding that is consistent with the human infection. These observations support the idea that locusts provide a tractable model to study Acanthamoeba encephalitis in vivo. In this way the locust model may generate potentially useful leads that can be tested subsequently in mammalian systems, thus replacing the use of vertebrates at an early stage, and reducing the numbers of mammals required overall.

  3. Real-time contrast-enhanced ultrasound determination of microvascular blood volume in abdominal subcutaneous adipose tissue in man. Evidence for adipose tissue capillary recruitment

    DEFF Research Database (Denmark)

    Tobin, L; Simonsen, L; Bülow, J

    2010-01-01

    The adipose tissue metabolism is dependent on its blood perfusion. During lipid mobilization e.g. during exercise and during lipid deposition e.g. postprandial, adipose tissue blood flow is increased. This increase in blood flow may involve capillary recruitment in the tissue. We investigated the...... basic and postprandial microvascular volume in adipose tissue using real-time contrast-enhanced ultrasound (CEU) imaging in healthy normal weight subjects. In nine subjects, CEU was performed in abdominal subcutaneous adipose tissue and in the underlying skeletal muscle after a bolus injection of...... ultrasound contrast agent to establish the reproducibility of the technique. In nine subjects, the effect of an oral glucose load on blood flow and microvascular volume was measured in abdominal subcutaneous adipose tissue and forearm skeletal muscle. ¹³³Xe washout and venous occlusion strain...

  4. Influence of Resting Venous Blood Volume Fraction on Dynamic Causal Modeling and System Identifiability.

    Science.gov (United States)

    Hu, Zhenghui; Ni, Pengyu; Wan, Qun; Zhang, Yan; Shi, Pengcheng; Lin, Qiang

    2016-01-01

    Changes in BOLD signals are sensitive to the regional blood content associated with the vasculature, which is known as V0 in hemodynamic models. In previous studies involving dynamic causal modeling (DCM) which embodies the hemodynamic model to invert the functional magnetic resonance imaging signals into neuronal activity, V0 was arbitrarily set to a physiolog-ically plausible value to overcome the ill-posedness of the inverse problem. It is interesting to investigate how the V0 value influences DCM. In this study we addressed this issue by using both synthetic and real experiments. The results show that the ability of DCM analysis to reveal information about brain causality depends critically on the assumed V0 value used in the analysis procedure. The choice of V0 value not only directly affects the strength of system connections, but more importantly also affects the inferences about the network architecture. Our analyses speak to a possible refinement of how the hemody-namic process is parameterized (i.e., by making V0 a free parameter); however, the conditional dependencies induced by a more complex model may create more problems than they solve. Obtaining more realistic V0 information in DCM can improve the identifiability of the system and would provide more reliable inferences about the properties of brain connectivity. PMID:27389074

  5. Blood volume increase in salt-induced pulmonary hypertension, heart failure and ascites in broiler and White Leghorn chickens.

    Science.gov (United States)

    Mirsalimi, S M; O'Brien, P J; Julian, R J

    1993-01-01

    In this study we tested the hypothesis that excess dietary salt produces an expansion of extracellular fluid volume which may be associated with pulmonary hypertension-induced right ventricular failure in chickens with rapid growth rates. One-week-old broiler and White Leghorn chickens were given 0.5% salt in their drinking water for three weeks. Saline water had a minimal effect on White Leghorns. The hypothesis appears to be correct since salt-treatment in broilers resulted in up to 30% expansion in blood volume and there was 50% mortality from pulmonary hypertension-induced right ventricular failure and ascites. There was marked (up to 88% in some broilers) right ventricular hypertrophy, an indicator of pulmonary hypertension. There was less left ventricular hypertrophy as shown by an increase in the ratio of the right to total ventricle weight. There was up to 32% decrease in growth rate. There was renal hypertrophy in the salt-treated birds as shown by a higher kidney to body weight ratio. PMID:8490804

  6. Seroepidemiology of HIV, syphilis and hepatitis B and C viruses among blood donors in Bangui, Central African Republic.

    Science.gov (United States)

    Nambei, W S; Rawago-Mandjiza, D; Gbangbangai, E

    2016-05-01

    The aim of this study was to determine the seroprevalence of HIV, the hepatitis B and C viruses, and syphilis as well the risk factors for these diseases among blood donors in Bangui, Central Africa Republic. This cross-sectional study examined samples from donors giving blood in August and September, 2013. HIV1/2 antibodies was screened with the Determine and Unigold HIV tests. Hepatitis B surface antigens were detected by sandwich immunochromatographic methods (DIAspot HBsAg test), and antibodies to HCV by the DIAspot test strip. Syphilis was diagnosed with the VDRL and TPHA methods (Omega Diagnostic, UK). The Chi(2) test was used for statistical analysis. The study included samples from 551 individuals, 350 (63.52%) of whom were frequent volunteer donors. In all, 132 (23.95%) were infected with at least one pathogen. The overall seroprevalence rate was 8.89% for HBV, 4.72% for HCV, 4.36% for syphilis, and 5.98% for HIV. Eight patients had two concomitant infections, with HIV-HBV the most common combination. Compared to long-term volunteers, first-time donors were more often infected by at least one of the pathogens we screened for, most especially HVB (OR = 5.06; 95% CI = 4.22-7.11) and syphilis (OR = 2.05; 95% CI = 2.02-7.44). Our findings indicate the high seroprevalence of transfusion-transmitted infections in blood donated in Bangui. The most common combined infections were HIV-HBV. The most common risk factor was a family history of HBV infection, and especially, mother-child transmission. PMID:27412978

  7. Water level and volume estimations of the Albano and Nemi lakes (central Italy

    Directory of Open Access Journals (Sweden)

    A. Mazzoni

    2008-06-01

    Full Text Available In April 2006 an airborne laser scanning (LIDAR survey of the Albano and Nemi craters was carried out to obtain a high resolution digital terrain model (DTM of the area. We have integrated the LIDAR survey of the craters and the recent bathymetry of the Albano lake to achieve a complete DTM, useful for morphological studies. In addition, with a GPS RTK survey (July 2007 we estimated the Albano and Nemi mean lake levels respectively at 288.16 m and 319.02 m (asl. Based on the integrated DTM and the newly estimated water level values, we evaluated about 21.7·106 m3 the water volume loss of the Albano lake from 1993 to 2007, with an average rate of about 1.6·106 m3/yr.

  8. The imidazoline receptors and the central regulation of the arterial blood pressure: a minireview

    Directory of Open Access Journals (Sweden)

    Eduardo Tibiriça

    1993-06-01

    Full Text Available Recently, we proposed the hypothesis according to wich the central hypotensive effect of clonidine and related substances could be related to an action upon specific receptors, requiring the imidazoline or imidazoline-like structures, rather than alpha2-adrenoceptors. Since then, direct evidences have been accumulated to confirm the existence of a population of imidazoline specific binding sites in the brainstem of animals and man, more precisely in the Nucleus Reticularis Lateralis (NRL region of the ventrolateral medulla (VLM, site of the antihypertensive action of clonidine. The purification of the putative endogenous ligand of the imidazoline receptors - named endazoline - is currently being attempted from human brain extracts. This new concept might at last lead to the expected dissociation of the pharmacological mechanisms involved, on the one hand, in the therapeutic antihypertensive effect, and on the other, in their major side-effect, which is sedation. In fact, it has been recently confirmed that hypotension is mediated by the activation of imidazoline preferring receptors (IPR within the NRL region, while sedation is attributed to the inhibition of alpha2-adrenergic mechanisms in the locus coeruleus, which is involved in the control of the sleep-waking cycle. The IPRmay constitute on interesting target for new drugs in the treatment of arterial hypertension. Finally, dysfunctions of this modulatory system which could be involved in the pathophysiologyof some forms of the hypertensive disease are under investigation.

  9. Blood biochemical profiles of thai indigenous and Simmental x Brahman crossbred cattle in the Central Thailand.

    Science.gov (United States)

    Boonprong, S; Sribhen, C; Choothesa, A; Parvizi, N; Vajrabukka, C

    2007-03-01

    Plasma biochemical profiles were studied in 112 mature (3 to 5-year-old) healthy cattle comprised of 61 Thai indigenous and 51 Simmental x Brahman crossbred male and cyclic female cattle at Nongkwang (Central Thailand) Livestock Research and Breeding Center, Thailand. Data were analysed for the effect of breed and sex. The results showed that the plasma glucose and gamma-glutamyl transferase (GGT) in the two breeds were significantly (P < 0.05) different. Furthermore, the urea, creatinine, albumin, total protein, aspartate amino transferase (AST), alanine amino transferase (ALT) and alkaline phosphatase (ALP) levels in Thai indigenous were significantly (P < 0.01) higher than in crossbred cattle. However, creatine kinase did not significantly differ in crossbred and indigenous animals. A sex difference was found in glucose level with male Thai indigenous having significantly higher levels (P < 0.05) than the other three groups. Plasma urea concentration in male crossbred cattle was lower than in the other groups (P < 0.05). Female crossbred cattle had significantly (P < 0.05) lower plasma creatinine levels than the other animals. Furthermore, levels of albumin in male and total protein in female crossbred were the lowest (P < 0.05) among the groups. The AST, ALT, ALP and GGT levels were significantly (P < 0.05) different between male and female. Female crossbred cattle had the lowest (P < 0.05) AST and GGT levels, whereas lowest (P < 0.05) ALT and ALP concentration was determined in male individuals of these breeds. PMID:17305967

  10. Le gouvernement international des frontières d’Asie centrale (Volumes 1 & 2)

    OpenAIRE

    Bigo, Didier; Martin-Maze, Médéric

    2013-01-01

    Le gouvernement international des frontières d’Asie centrale (Kirghizstan, Tadjikistan, Ouzbékistan, Kazakhstan, Turkménistan) comprend les projets de gestion des frontières conduits par l’OSCE, la Commission européenne, l’ONUDC et l’OIM entre 1992 et 2012. Ils organisent l’import/export d’une expertise alignant les limites étatiques dans cette région sur un double impératif de mobilité et de sécurité. Comment ces savoirs sur la frontière circulent-ils à travers ces dernières ? Les projets p...

  11. Blood volume-monitored regulation of ultrafiltration in fluid-overloaded hemodialysis patients: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Hecking Manfred

    2012-06-01

    Full Text Available Abstract Background Data generated with the body composition monitor (BCM, Fresenius show, based on bioimpedance technology, that chronic fluid overload in hemodialysis patients is associated with poor survival. However, removing excess fluid by lowering dry weight can be accompanied by intradialytic and postdialytic complications. Here, we aim at testing the hypothesis that, in comparison to conventional hemodialysis, blood volume-monitored regulation of ultrafiltration and dialysate conductivity (UCR and/or regulation of ultrafiltration and temperature (UTR will decrease complications when ultrafiltration volumes are systematically increased in fluid-overloaded hemodialysis patients. Methods/design BCM measurements yield results on fluid overload (in liters, relative to extracellular water (ECW. In this prospective, multicenter, triple-arm, parallel-group, crossover, randomized, controlled clinical trial, we use BCM measurements, routinely introduced in our three maintenance hemodialysis centers shortly prior to the start of the study, to recruit sixty hemodialysis patients with fluid overload (defined as ≥15% ECW. Patients are randomized 1:1:1 into UCR, UTR and conventional hemodialysis groups. BCM-determined, ‘final’ dry weight is set to normohydration weight −7% of ECW postdialysis, and reached by reducing the previous dry weight, in steps of 0.1 kg per 10 kg body weight, during 12 hemodialysis sessions (one study phase. In case of intradialytic complications, dry weight reduction is decreased, according to a prespecified algorithm. A comparison of intra- and post-dialytic complications among study groups constitutes the primary endpoint. In addition, we will assess relative weight reduction, changes in residual renal function, quality of life measures, and predialysis levels of various laboratory parameters including C-reactive protein, troponin T, and N-terminal pro-B-type natriuretic peptide, before and after the first study

  12. The Pilot Study of Evaluating Fluctuation in the Blood Flow Volume of the Radial Artery, a Site for Traditional Pulse Diagnosis

    Directory of Open Access Journals (Sweden)

    Masashi Watanabe

    2016-05-01

    Full Text Available Background: Radial artery (RA pulse diagnosis has been used in traditional Asian medicine. Blood pressure (BP and pulse rate related to heart rate variability (HRV can be monitored via the RA. The fluctuation in these parameters has been assessed using fast Fourier transform (FFT analytical methods that calculate power spectra. Methods: We measured blood flow volume (Volume in the RA and evaluated its fluctuations. Normal participants (n = 34 were enrolled. We measured the hemodynamics of the right RA for approximately 50 s using ultrasonography. Results: The parameters showed the center frequency (CF of the power spectrum at low frequency (LF and high frequency (HF. More than one spectral component indicated that there were fluctuations. The CF at LF for Volume was significantly different from that for vessel diameter (VD; however, it was significantly correlated with blood flow velocity (Velocity. On the other hand, the CF at HF for Volume was significantly different from that for Velocity; however, it was significantly correlated with VD. Conclusion: It is suggested that fluctuation in the Volume at LF of RA is influenced by the fluctuation in Velocity; on the other hand, fluctuation in the Volume at HF is influenced by the fluctuation in VD.

  13. Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

    Directory of Open Access Journals (Sweden)

    Arheden Håkan

    2011-04-01

    Full Text Available Abstract Background Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Methods Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Results Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Conclusion Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking

  14. Combined cycle solar central receiver hybrid power system study. Final technical report. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    This study develops the conceptual design for a commercial-scale (nominal 100 MWe) central receiver solar/fossil fuel hybrid power system with combined cycle energy conversion. A near-term, metallic heat pipe receiver and an advanced ceramic tube receiver hybrid system are defined through parametric and market potential analyses. Comparative evaluations of the cost of power generation, the fuel displacement potential, and the technological readiness of these two systems indicate that the near-term hybrid system has better potential for commercialization by 1990. Based on the assessment of the conceptual design, major cost and performance improvements are projected for the near-term system. Constraints preventing wide-spread use were not identified. Energy storage is not required for this system and analyses show no economic advantages with energy storage provisions. It is concluded that the solar hybrid system is a cost effective alternative to conventional gas turbines and combined cycle generating plants, and has potential for intermediate-load market penetration at 15% annual fuel escalation rate. Due to their flexibility, simple solar/nonsolar interfacing, and short startup cycles, these hybrid plants have significant operating advantages. Utility company comments suggest that hybrid power systems will precede stand-alone solar plants.

  15. Central Line Associated Blood Stream Infection Rate after Intervention and Comparing Outcome with National Healthcare Safety Network and International Nosocomial Infection Control Consortium Data

    OpenAIRE

    Bukhari, SZ; Banjar, A.; Baghdadi, SS; Baltow, BA; Ashshi, AM; Hussain, WM

    2014-01-01

    Background: Benchmarking of central line associated blood stream infection (CLABSI) rates remains a problem in developing countries due to the variations in surveillance practices and/or infection risk as non-availability of national data. Aim: The aim of the following study was to find out the CLABSI rate before and after central line (CL) bundle intervention and compare the outcome with international surveillance data. Subjects and Methods: This prospective longitudinal cohort study on adul...

  16. Effects on peripheral and central blood pressure of cocoa with natural or high-dose theobromine: A randomized, double-blind crossover trial

    OpenAIRE

    Bogaard, Bas; Draijer, Richard; Westerhof, Berend; Meiracker, Anton; Montfrans, Gert; Born, B.J.H.

    2010-01-01

    textabstractFlavanol-rich cocoa products have been reported to lower blood pressure. It has been suggested that theobromine is partially responsible for this effect. We tested whether consumption of flavanol-rich cocoa drinks with natural or added theobromine could lower peripheral and central blood pressure. In a double-blind, placebo-controlled 3-period crossover trial we assigned 42 healthy individuals (age 62±4.5 years; 32 men) with office blood pressure of 130 to 159 mm Hg/85 to 99 mm Hg...

  17. Ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan mountains, central Asia, by ground penetrating radar survey

    Indian Academy of Sciences (India)

    Puyu Wang; Zhongqin Li; Shuang Jin; Ping Zhou; Hongbing Yao; Wenbin Wang

    2014-04-01

    The results of radar survey for three times are presented, aiming to determine ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan Mountains, central Asia. Results show that the distribution of ice is more in the center and lesser at both ends of the glacier. The bedrock is quite regular with altitudes decreasing towards the ice front, showing the U-shaped subglacial valley. By comparison, typical ice thinning along the centerline of the East Branch of the glacier was 10–18 m for the period 1981–2006, reaching a maximum of ∼30 m at the terminus. The corresponding ice volume was 10296.2 × 104 m3, 8797.9 × 104 m3 and 8115.0 × 104 m3 in 1981, 2001 and 2006, respectively. It has decreased by 21.2% during the past 25 years, which is the direct result of glacier thinning. In the same period, the ice thickness, area and terminus decreased by 12.2%, 10.3%, and 3.6%, respectively. These changes are responses to the regional climatic warming, which show a dramatic increase of 0.6°C (10 a)−1 during the period 1981–2006.

  18. Blood pressure levels, left ventricular mass and function are correlated with left atrial volume in mild to moderate hypertensive patients.

    Science.gov (United States)

    Milan, A; Caserta, M A; Dematteis, A; Naso, D; Pertusio, A; Magnino, C; Puglisi, E; Rabbia, F; Pandian, N G; Mulatero, P; Veglio, F

    2009-11-01

    Arterial hypertension is associated with an increased risk of atrial fibrillation (AF), and leads to a pronounced increase in morbidity and mortality. Left atrial volume (LAV) is an important prognostic marker in the older populations. The aim of our study was to identify the clinical and echocardiographic determinants of LAV in middle-aged (<70 years old) essential hypertensive patients.We evaluated cardiac structure and function in 458 patients, 394 treated and untreated mild to moderate essential hypertensives patients (mean+/-s.d. age 48.4+/-11.1 years) with no associated clinical condition and 64 normotensive control participants (age 45.7+/-12.8 years; P=0.12). A multivariate analysis was performed to calculate the relative weight of each of the variables considered able to predict LAV. The LAV index (LAVi) was significantly increased in the essential hypertensive group vs the control group and was significantly dependent on blood pressure levels (SBP and DBP, P<0.05 for both) and body mass index (BMI) (P<0.0001). Considering the left ventricular (LV) variables, the LV mass index (LVMI) (R(2)=0.19, P<0.001) and LAV were increased in essential hypertensive patients with left ventricular hypertrophy (LVH), and patients with enlarged LAV showed lower systolic and diastolic function and an increased LVMI. The LAVi is dependent on blood pressure levels and anthropometric variables (age and BMI). Further structural (LVMI) and functional (systolic and diastolic) variables are related to the LAVi; LVMI is the most important variable associated with LAV in mild to moderate essential hypertensive adult patients. These findings highlight the importance of left atrium evaluation in adult, relatively young, essential hypertensive patients. PMID:19262581

  19. Effect of saline infusion for the maintenance of blood volume on pulmonary gas exchange during temporary abdominal aortic occlusion

    Directory of Open Access Journals (Sweden)

    F.F. Amorim

    2007-03-01

    Full Text Available We analyzed the effects of saline infusion for the maintenance of blood volume on pulmonary gas exchange in ischemia-reperfusion syndrome during temporary abdominal aortic occlusion in dogs. We studied 20 adult mongrel dogs weighing 12 to 23 kg divided into two groups: ischemia-reperfusion group (IRG, N = 10 and IRG submitted to saline infusion for the maintenance of mean pulmonary arterial wedge pressure between 10 and 20 mmHg (IRG-SS, N = 10. All animals were anesthetized and maintained on spontaneous ventilation. After obtaining baseline measurements, occlusion of the supraceliac aorta was performed by the inflation of a Fogarty catheter. After 60 min of ischemia, the balloon was deflated and the animals were observed for another 60 min of reperfusion. The measurements were made at 10 and 45 min of ischemia, and 5, 30, and 60 min of reperfusion. Pulmonary gas exchange was impaired in the IRG-SS group as demonstrated by the increase of the alveolar-arterial oxygen difference (21 ± 14 in IRG-SS vs 11 ± 8 in IRG after 60 min of reperfusion, P = 0.004 in IRG-SS in relation to baseline values and the decrease of oxygen partial pressure in arterial blood (58 ± 15 in IRG-SS vs 76 ± 15 in IRG after 60 min of reperfusion, P = 0.001 in IRG-SS in relation to baseline values, which was correlated with the highest degree of pulmonary edema in morphometric analysis (0.16 ± 0.06 in IRG-SS vs 0.09 ± 0.04 in IRG, P = 0.03 between groups. There was also a smaller ventilatory compensation of metabolic acidosis after the reperfusion. We conclude that infusion of normal saline worsened the gas exchange induced by pulmonary reperfusion injury in this experimental model.

  20. Evaluation of the cardiac performance in patients with coronary arterty disease by the pulmonary blood volume change in exercise testing

    International Nuclear Information System (INIS)

    Evaluation of the cardiac performance was studied by the change of the pulmonary blood volume (PBV) during the exercise testing in 17 normal subjects (group N), 18 patients with angina pectoris (group A) and 25 with both old myocardial infarction and angina pectoris (group M). The exercise testing was performed by bicycle ergometer in supine position. Blood pressure, heart rate, cardiac output measured by dye dilution method, left ventricular ejection fraction (EF) by multi-gate method, pulmonary artery pressure by Swan-Ganz catheter and PBV was measured during exercise. PBV was estimated by the radioactivity of the systemically administered Tc-99m labeled RBC in the lung field. ROI was adjusted over the right upper and lower lung field. And also the effect of the nitroglycerin was examined. In the result, (1) EF at the peak exercise increased in group N but decreased in Groups A and M. (2) Increased pulmonary artery diastolic pressure at the peak exercise (PAd at exercise) was remarkably higher in groups A and M than group M. (3) PBV was unchanged in group N; however, increased 9.6% in group A and 10.9% in group M. (4) Increased rate of PBV revealed good correlation with ΔEF (r=-0.68, p<0.01) and PAd at exercise (r=0.83, p<0.01), and was considered as the pulmonary congestion due to left ventricular dysfunction. (5) After the sublingual administration of nitroglycerin, the increased PAd and PBV at the peak exercise was suppressed. Particularly, it was remarkable in group A. Thus it was concluded that the noninvasive measurement of PBV during exercise could suggest the extent of the pulmonary congestion and was very useful for evaluation of the cardiac performance in coronary artery disease. (author)

  1. Blood-retinal barrier glycerol permeability in diabetic macular edema and healthy eyes: estimations from macular volume changes after peroral glycerol

    DEFF Research Database (Denmark)

    Thornit, Dorte Nellemann; Vinten, Carl Martin; Sander, Birgit;

    2010-01-01

    PURPOSE: To compare the changes in macular volume (MV) between healthy subjects and patients with diabetic macular edema (DME) after an osmotic load and to determine the glycerol permeability (P(gly)) of the blood-retinal barrier (BRB). METHODS: In this unmasked study, 13 patients with DME and 5...

  2. Validation of quantitative estimation of tissue oxygen extraction fraction and deoxygenated blood volume fraction in phantom and in vivo experiments by using MRI.

    Science.gov (United States)

    Sedlacik, Jan; Reichenbach, Jürgen R

    2010-04-01

    The blood oxygenation level dependent signal of cerebral tissue can be theoretically derived using a network model formed by randomly oriented infinitely long cylinders. The validation of this model by phantom and in vivo experiments is still an object of research. A network phantom was constructed of solid polypropylene strings immersed in silicone oil, which essentially eliminated the effect of spin diffusion. The volume fraction and magnetic property of the string network was predetermined by independent methods. Ten healthy volunteers were measured for in vivo demonstration. The gradient echo sampled spin echo signal was evaluated with the cylinder network model. We found a strong interdependency between the two network characterizing parameters deoxygenated blood volume and oxygen extraction fraction. Here, different sets of deoxygenated blood volume/oxygen extraction fraction values were able to describe the measured signal equally well. However, by setting one parameter constant to a predetermined value, reasonable estimates of the other parameter were obtained. The same behavior was found for the in vivo demonstration. The signal theory of the cylinder network was validated by a well-characterized phantom. However, the found interdependency that was found between deoxygenated blood volume and oxygen extraction fraction requires an independent estimation of one variable to determine reliable values of the other parameter. PMID:20373392

  3. The evolution of the cerebral blood volume abnormality in patients with ischemic stroke: a CT perfusion study

    Energy Technology Data Exchange (ETDEWEB)

    D' Esterre, Christopher D.; Lee, Ting Yim (Lawson Health Research Inst., London (Canada); Robarts Research Inst., London (Canada)), email: tlee@robarts.ca; Aviv, Richard I. (Sunnybrook Health Sciences Centre, Toronto (Canada))

    2012-05-15

    Background: Accurate identification of the acute infarct core abnormality is important for guiding acute stroke treatment. Abnormality volumes from diffusion-weighted MRI (DWI) and CT perfusion (CTP)-cerebral blood volume (CBV) are highly correlated. DWI lesions have been shown to be reversible at 24 h. Purpose: To examine the temporal profile of the CT perfusion (CTP)-derived CBV abnormality out to 7 days post ischemic stroke. Material and Methods: Twenty-six patients were included. Group A (n = 13) underwent a noncontrast CT (NCCT), CTP/CT angiography (CTA) within 6 h of stroke onset, CTP/CTA at 24 h, and CTP/NCCT at 5-7 days post stroke. Group B (n = 13) underwent a NCCT, CTP/CTA within 6 h of stroke onset, and NCCT at 5-7 days. Recanalization status was established in all patients. For both groups, infarct volumes were traced on 5-7 day NCCT images and superimposed onto all CTP-CBV functional maps to determine CBV. Group B (n = 13) admission images were used to define CBV infarct thresholds for gray and white matter. CBV-lesion overestimation was determined for Group A using the thresholds from Group B. Results: CBV (ml x 100g- 1; mean +- stdev) for gray/white matter, within confirmed infarcted regions (CBVI) at admission, 24 h, and 5-7 days were 1.82 +- 0.56, 1.56 +- 0.42, 1.75 +- 0.31, and 1.38 +- 0.65, 1.13 +- 0.31, 1.32 +- 0.44, respectively, when averaged over all patients (P > 0.05). Four patients had tissue time-density curves from ischemic lesions (TDCi) with an incomplete contrast medium wash-out phase (truncation) at admission and/or 24 h. Compared to admission, gray matter CBVI was higher at 5-7 days for patients with TDCi truncation (P < 0.05). There were no significant CBVI increases for the eight patients without truncation (P > 0.05). Over-estimation of acute CBV lesion was present in 3/4 (75%) and 1/9 (11%) of patients with/without TDCi truncation, respectively. Conclusion: CTP-derived CBV lesion reversal is associated with TDCi truncation

  4. Angiotensin II type 1 receptors and systemic hemodynamic and renal responses to stress and altered blood volume in conscious rabbits

    Directory of Open Access Journals (Sweden)

    RogerGeorgeEvans

    2011-07-01

    Full Text Available We examined how systemic blockade of type 1 angiotensin (AT1- receptors affects reflex control of the circulation and the kidney. In conscious rabbits, the effects of candesartan on responses of systemic and renal hemodynamics and renal excretory function to acute hypoxia, mild hemorrhage and plasma volume expansion were tested. Candesartan reduced resting mean arterial pressure (MAP, -8 ± 2% without significantly altering cardiac output (CO, increased renal blood flow (RBF, +38 ± 9% and reduced renal vascular resistance (RVR, -32 ± 6%. Glomerular filtration rate (GFR was not significantly altered but sodium excretion (UNa+V increased four-fold. After vehicle treatment, hypoxia (10% inspired O2 for 30 min did not significantly alter MAP or CO, but reduced HR (-17 ± 6%, increased RVR (+33 ± 16% and reduced GFR (-46 ± 16% and UNa+V (-41 ± 17%. Candesartan did not significantly alter these responses. After vehicle treatment, plasma volume expansion increased CO (+35 ± 7%, reduced total peripheral resistance (TPR, -26 ± 5%, increased RBF (+62 ± 23% and reduced RVR (-32 ± 9%, but did not significantly alter MAP or HR. It also increased UNa+V (803 ± 184% yet reduced GFR (-47 ± 9%. Candesartan did not significantly alter these responses. After vehicle treatment, mild hemorrhage did not significantly alter MAP but increased HR (+16 ± 3%, reduced CO (-16 ± 4% and RBF (-18 ± 6%, increased TPR (+18 ± 4% and tended to increase RVR (+18 ± 9%, P = 0.1, but had little effect on GFR or UNa+V. But after candesartan treatment MAP fell during hemorrhage (-19 ± 1%, while neither TPR nor RVR increased, and GFR (-64 ± 18% and UNa+V (-83 ± 10% fell. AT1-receptor activation supports MAP and GFR during hypovolemia. But AT1-receptors appear to play little role in the renal vasoconstriction, hypofiltration and antinatriuresis accompanying hypoxia, or the systemic and renal vasodilatation and natriuresis accompanying plasma volume expansion.

  5. The safest parameters for FUS-induced blood-brain barrier opening without effects on the opening volume

    Science.gov (United States)

    Tung, Yao-Sheng; Olumolade, Yemi; Wang, Shutao; Wu, Shih-Ying; Konofagou, Elisa E.

    2012-11-01

    Acoustic cavitation has been identified as the main physical mechanism for the focused ultrasound (FUS) induced blood-brain barrier (BBB) opening. In this paper, the mechanism of stable cavitation (SC) and inertial cavitation (IC) responsible for BBB opening was investigated. Thirty-three (n=33) mice were intravenously injected with bubbles of 4-5 μm in diameter. The right hippocampus was then sonicated using focused 1.5-MHz ultrasound and three different studies were carried out. First, pulse lengths (PLs) of 0.1, 0.5, 2, and 5 ms at 0.18- MPa peak rarefactional pressure with 5-Hz pulse repetition frequency (PRF) and 5-minute duration were used to identify the threshold of PL using SC. Second, the effects of the duty cycle and exposure time were investigated. Third, the BBB opening size was compared between the SC and the IC. In the case of IC-induced BBB opening, a burst sequence (3-cycles PL; 5-Hz burst repetition frequency (BRF); 30 s duration) at 0.45 MPa was applied. Passive cavitation detection was performed with each sonication to detect whether a broadband response was obtained, i.e., if IC occurred, during BBB opening. The properties of BBB opening were measured through MRI. The threshold of PL for BBB opening was identified between 0.1 and 0.5 ms using SC, but the BBB can be opened in few cycles using IC. The BBB opening volume and normalized intensity increased with the PL, but reached saturation when the PL was above 2 ms. Once the PL threshold was reached, the same exposure time induced a similar BBB opening volume, but longer sonication duration induced higher MR intensity. The duty cycle was found not to play an important role on the BBB opening. Comparable BBB opening volume (20-25 mm3) could be reached between long PL (7500 cycles, i.e., 5 ms) at 0.18 MPa and 3 cycles at 0.45 MPa. 3-kDa fluorescently tagged dextran may be able to diffuse to the parenchyma after IC-induced BBB opening at 0.45 MPa but not after SC-induced BBB opening at 0.18 MPa.

  6. MR-based cerebral blood volume maps as a diagnostic tool of stroke: results of a clinical pilot study

    International Nuclear Information System (INIS)

    In this study the sensitivity of proving a stroke using regional cerebral blood volume (rCBV) maps were investigated. Another aim was to evaluate the strength of the ischaemia. Seven patients were examined during the acute phase of a stroke, eight during the subacute or chronically stage. To calculate rCBV-maps of one slice low dosed Gd-DTPA was injected as a bolus. Using the relaxation-effect the obtained signal intensity-time curves were converted pixel-wise to rCBV images. For the region of the infarction rCBV ratios were calculated relative to the corresponding area in the contralateral hemisphere. Only 63% of the investigations carried out during the acute phase were utilizable. In all those cases a decrease of rCBV was found. The infarct area could only be visually recognized if the rCBV ratio was lower than 0.7. The ratios of completely and partical necrotic areas of the infarctions were 0.481 and 1.028 respectively. With a p=0.0015 these values are even statistically different. During the acute stage the sensitivity of the rCBV measurement was not as high as that of morphological MR imaging. However, rCBV maps make it possible to estimate the strength of the ischaemia even during the first hours. (orig./MG)

  7. Non-invasive estimation of the human pulmonary blood volume with gamma camera and RI-angiocardiography

    International Nuclear Information System (INIS)

    A new, non-invasive method for the estimation of the human pulmonary blood volume (PBV), existing between the pulmonary artery bifurcation (PAB) and the left atrium (LA), has been developed in this laboratory, in the form of PBV = PPT sub(RCG) x 0.77 x CO, equation (6), given in Appendix. This was an extension of the classical Stewart-Hamilton method of indicator dilution, applied to radioisotope angiocardiography. Using a gamma-camera, the radio-isotope (99 m Tc-albumin) dilution curves were recorded externally at the region of PAB, LA and LV (left ventricle), among other things, in human subjects in supine position. The mean transit time (MTT) was determined for each region, and the difference in MTT, e.g., ΔMTT sub(PAB-LA), was measured. We calculated PBV between PAB and LA as PBV = ΔMTT sub(PAB-LA) x CO, equation (1) given in Appendix. Empirical time relations between ΔMTT sub(PAB-LA) and PPT sub(RCG) were examined in mechanical models and human subjects, through several steps represented by equations (2) to (5), given in Appendix, and our tentatively final formula was equation (6). The values of PBV estimated in this way were in good agreement with those of PBV measured invasively in the past, using two injection sites (PA and LA) and one sampling site (artery). (author)

  8. Influence of vascular enhancement, age and gender on pulmonary perfused blood volume quantified by dual-energy-CTPA

    Energy Technology Data Exchange (ETDEWEB)

    Meinel, Felix G., E-mail: felix.meinel@med.uni-muenchen.de; Graef, Anita, E-mail: anita.graef@med.uni-muenchen.de; Sommer, Wieland H., E-mail: wieland.sommer@uni-muenchen.de; Thierfelder, Kolja M., E-mail: kolja.thierfelder@uni-muenchen.de; Reiser, Maximilian F., E-mail: maximilian.reiser@med.uni-muenchen.de; Johnson, Thorsten R.C., E-mail: thorsten.johnson@med.uni-muenchen.de

    2013-09-15

    Objectives: To determine the influence of technical and demographic parameters on quantification of pulmonary perfused blood volume (PBV) in dual energy computed tomography pulmonary angiography (DE-CTPA). Materials and methods: Pulmonary PBV was quantified in 142 patients who underwent DE-CTPA for suspected pulmonary embolism but in whom no thoracic pathologies were detected. Multivariate linear regression analysis was performed to calculate the influence of age, gender, enhancement of pulmonary trunk and enhancement difference between pulmonary trunk and left atrium (as a measure of timing) on PBV values. The resulting regression coefficients were used to calculate age-specific ranges of normal for PBV values adjusted for vascular enhancement and timing. Results: Enhancement of the pulmonary trunk (β = −0.29, p = 0.001) and enhancement difference between pulmonary trunk and left atrium (β = −0.24, p = 0.003) were found to significantly influence PBV values. Age (β = −0.33, p < 0.001) but not gender (β = 0.14, p = 0.05) had a significant negative influence on pulmonary PBV values. There was a 20% relative decrease of pulmonary PBV from patients aged <30 to patients over 80 years of age. Conclusions: DE-CTPA derived PBV values need to be corrected for age, vascular enhancement and timing but not for gender. The age-specific ranges of normal derived from this study can be used as a reference in future studies of PBV in pulmonary pathologies.

  9. Pre-operative grading of intracranial glioma. Comparison of MR-determined cerebral blood volume maps with thallium-201 SPECT

    International Nuclear Information System (INIS)

    Aim: To compare the accuracy of MR-determined cerebral blood volume (CBV) maps with SPECT imaging with thallium-201 in pre-operative grading of intracranial glioma. Material and Methods: Nineteen patients (7 female and 12 male, mean age 46.8 years) with intracranial gliomas were examined with MR perfusion imaging pre-operatively. Sixteen of these patients were also examined with SPECT imaging with thallium-201. The tumour to contralateral white matter NI (negative integral) and tracer uptake ratios were evaluated. The ratios in high-grade and low-grade tumours were compared. Results: The maximum CBV ratios of grades I and II gliomas (2.958±2.217) were significantly lower than the maximum CBV ratio of grades III and IV (9.484±4.520), p<0.001. There was no statistical difference when CBV ratios of grades I and II (p=0.381), grades II and III (p=0.229) and grades III and IV (p=0.476) gliomas were compared. Thallium SPECT imaging showed no difference in tumour uptake ratio between low-grade and high-grade gliomas (p=0.299). Conclusion: MR-determined NI was useful for pre-operative grading of intracranial gliomas but SPECT thallium-201 imaging was not

  10. Partial volume correction of the microPET blood input function using ensemble learning independent component analysis

    International Nuclear Information System (INIS)

    Medical images usually suffer from a partial volume effect (PVE), which may degrade the accuracy of any quantitative information extracted from the images. Our aim was to recreate accurate radioactivity concentration and time-activity curves (TACs) by microPET R4 quantification using ensemble learning independent component analysis (EL-ICA). We designed a digital cardiac phantom for this simulation and in order to evaluate the ability of EL-ICA to correct the PVE, the simulated images were convoluted using a Gaussian function (FWHM = 1-4 mm). The robustness of the proposed method towards noise was investigated by adding statistical noise (SNR = 2-16). During further evaluation, another set of cardiac phantoms were generated from the reconstructed images, and Poisson noise at different levels was added to the sinogram. In real experiments, four rat microPET images and a number of arterial blood samples were obtained; these were used to estimate the metabolic rate of FDG (MRFDG). Input functions estimated using the FastICA method were used for comparison. The results showed that EL-ICA could correct PVE in both the simulated and real cases. After correcting for the PVE, the errors for MRFDG, when estimated by the EL-ICA method, were smaller than those when TACs were directly derived from the PET images and when the FastICA approach was used.

  11. Influence of vascular enhancement, age and gender on pulmonary perfused blood volume quantified by dual-energy-CTPA

    International Nuclear Information System (INIS)

    Objectives: To determine the influence of technical and demographic parameters on quantification of pulmonary perfused blood volume (PBV) in dual energy computed tomography pulmonary angiography (DE-CTPA). Materials and methods: Pulmonary PBV was quantified in 142 patients who underwent DE-CTPA for suspected pulmonary embolism but in whom no thoracic pathologies were detected. Multivariate linear regression analysis was performed to calculate the influence of age, gender, enhancement of pulmonary trunk and enhancement difference between pulmonary trunk and left atrium (as a measure of timing) on PBV values. The resulting regression coefficients were used to calculate age-specific ranges of normal for PBV values adjusted for vascular enhancement and timing. Results: Enhancement of the pulmonary trunk (β = −0.29, p = 0.001) and enhancement difference between pulmonary trunk and left atrium (β = −0.24, p = 0.003) were found to significantly influence PBV values. Age (β = −0.33, p < 0.001) but not gender (β = 0.14, p = 0.05) had a significant negative influence on pulmonary PBV values. There was a 20% relative decrease of pulmonary PBV from patients aged <30 to patients over 80 years of age. Conclusions: DE-CTPA derived PBV values need to be corrected for age, vascular enhancement and timing but not for gender. The age-specific ranges of normal derived from this study can be used as a reference in future studies of PBV in pulmonary pathologies

  12. Non-invasive laser Doppler perfusion measurements of large tissue volumes and human skeletal muscle blood RMS velocity

    International Nuclear Information System (INIS)

    This study proposes the implementation of an algorithm allowing one to derive absolute blood root-mean-square (RMS) velocity values from laser Doppler perfusion meter (LDP) data. The algorithm is based on the quasi-elastic light scattering theory and holds for multiple scattering. While standard LDP measurements are normally applicable to a small region of interest (∼1 mm2), the present method allows the analysis of both small and large tissue volumes with small and large interoptode spacings (e.g., 1.5 cm). The applicability and the limits of the method are demonstrated with measurements on human skeletal muscle using a custom-built near-infrared LDP meter. Human brachioradialis muscle RMS velocity values of 9.99 ± 0.01 and 5.58 ± 0.03 mm s-1 at 1.5 cm and of 5.18 ± 0.01 and 2.54 ± 0.09 mm s-1 at 2 cm were found when the arm was (a) at rest and (b) occluded, respectively. At very large optode spacings or very high moving particle densities, the theory developed here would need to be amended to take into account second-order effects

  13. Evaluation of absolute left ventricular volume by gated equilibrium blood pool scintigraphy using count-based method. Clinical study

    Energy Technology Data Exchange (ETDEWEB)

    Anno, Hirofumi; Takeuchi, Akira; Ejiri, Kazutaka

    1987-12-01

    In order to estimate the absolute left ventricular volume (LVV) and the cradiac output (CO), gated equilibrium blood pool scintigraphy was performed. CO by radionuclide (RN) method was compared with CO simultaneously measured by thermodilution method (TDM) using Swan-Ganz catheter in 22 patients with cardiac diseases. To improve these determinations by RN, LVV using the count-based method was corrected by each of four transmission factors (TF1 = 1, TF2 (water) = e/sup -0.15d/, TF3 = e/sup -0.13d/ and TF4 = 1 - (1 - e/sup -0.125d/)/sup 1.26/ d: depth). We compared CO by RN with by TDM. CO by RN was significantly correlated with TDM: TF1 (CO (RN) = 0.23 x CO (TDM) + 0.08, r = 0.628, p < 0.002), TF (CO (RN) = 1.10 x CO (TDM) - 0.47, r = 0.914, p < 0.001), TF3 (CO (RN) = 0.89 x CO (TDM) - 0.30, r = 0.912, p < 0.001), and TF4 (CO (RN) = 0.71 x CO (TDM) - 0.23, r = 0.911, p < 0.001), respectively. These results indicate that the linear sttenuation correction is necessary and sufficient for accurate measurement of LVV and CO by RN using count-based method in clinical use.

  14. Correlation of compliance with central line associated blood stream infection guidelines and outcomes: a review of the evidence

    Directory of Open Access Journals (Sweden)

    Gerkin R

    2012-05-01

    Full Text Available Background Clinical practice guidelines are developed to assist in patient care but the evidence basis for many guidelines has been called into question. Methods We conducted a literature review using PubMed and analyzed the overall quality of evidence and made strength of recommendation behind 8 Institute of Health Care (IHI guidelines for prevention of central line associated blood stream infection (CLABSI. Quality of evidence was assessed by the American Thoracic Society (ATS levels of evidence (levels I through III. We also examined data from our intensive care units (ICUs for evidence of a correlation between guideline compliance and the development of VAP.Results None of the guidelines was graded at level I. Two of the guidelines were graded at level II and the remaining 6 at level III. Despite the lack of evidence, 2 of the guidelines (hand hygiene, sterile gloves were given a strong recommendation. Chlorhexidine and use of nonfemoral sites were given a moderate recommendation. In our ICUs compliance with the use of chlorhexidine correlated with a reduction in CLABSI (p<0.02 but the remainder did not.Conclusions The IHI CLABSI guidelines are based on level II or III evidence. Data from our ICUs supported the use of chlorhexidine in reducing CLABSI. Until more data from well-designed controlled clinical trials become available, physicians should remain cautious when using current IHI guidelines to direct patient care decisions or as an assessment of the quality of care.

  15. In Vitro Mean Red Blood Cell Volume Change Induced by Diode Pump Solid State Low-Level Laser of 405 nm

    Science.gov (United States)

    Jafar, Mohamad Suhaimi; Al-Gailani, Bassam T.; Ahmed, Naser Mahmoud; Suhaimi, Fatanah Mohamad; Suardi, Nursakinah

    2016-01-01

    Abstract Objective: This study was conducted to investigate the effects of low-level laser (LLL) doses on human red blood cell volume. The effects of exposure to a diode pump solid state (DPSS) (λ = 405 nm) laser were observed. Background data: The response of human blood to LLL irradiation gives important information about the mechanism of interaction of laser light with living organisms. Materials and methods Blood samples were collected into ethylenediaminetetraacetic acid (EDTA)-containing tubes, and each sample was divided into two equal aliquots, one to serve as control and the other for irradiation. The aliquot was subjected to laser irradiation for 20, 30, 40, or 50 min at a fixed power density of 0.03 W/cm2. Mean cell volume (MCV) and red blood cell (RBC) counts were measured immediately after irradiation using a computerized hemtoanalyzer. Results: Significant decrease in RBC volume (p < 0.05, p < 0.0001, p < 0.0001, and p < 0.05, respectively) was induced with variation in laser doses.The highest response was observed with an exposure time of 40 min. This result was reproduced in RBCs suspended in a buffered NaCl solution. In contrast to this finding, laser-induced RBC volume change was completely abolished by suspending RBCs in a solution containing a higher concentration of EDTA. Conclusions: It was suggested that LLL can reduce RBC volume possibly because of the increased free intracellular Ca+2 concentrations, which activate Ca+2-dependent K+ channels with consequent K+ ion efflux and cell shrinkage. PMID:26966989

  16. The influence of hyperoxia on regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV) and cerebral blood flow velocity in the middle cerebral artery (CBFVMCA) in human volunteers.

    Science.gov (United States)

    Kolbitsch, Christian; Lorenz, Ingo H; Hörmann, Christoph; Hinteregger, Martin; Löckinger, Alexander; Moser, Patrizia L; Kremser, Christian; Schocke, Michael; Felber, Stephan; Pfeiffer, Karl P; Benzer, Arnulf

    2002-09-01

    Conflicting results reported on the effects of hyperoxia on cerebral hemodynamics have been attributed mainly to methodical and species differences. In the present study contrast-enhanced magnetic resonance imaging (MRI) perfusion measurement was used to analyze the influence of hyperoxia (fraction of inspired oxygen (FiO2) = 1.0) on regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) in awake, normoventilating volunteers (n = 19). Furthermore, the experiment was repeated in 20 volunteers for transcranial Doppler sonography (TCD) measurement of cerebral blood flow velocity in the middle cerebral artery (CBFV(MCA)). When compared to normoxia (FiO2 = 0.21), hyperoxia heterogeneously influenced rCBV (4.95 +/- 0.02 to 12.87 +/- 0.08 mL/100g (FiO2 = 0.21) vs. 4.50 +/- 0.02 to 13.09 +/- 0.09 mL/100g (FiO2 = 1.0). In contrast, hyperoxia diminished rCBF in all regions (68.08 +/- 0.38 to 199.58 +/- 1.58 mL/100g/min (FiO2 = 0.21) vs. 58.63 +/- 0.32 to 175.16 +/- 1.51 mL/100g/min (FiO2 = 1.0)) except in parietal and left frontal gray matter. CBFV(MCA) remained unchanged regardless of the inspired oxygen fraction (62 +/- 9 cm/s (FiO2 = 0.21) vs. 64 +/- 8 cm/s (FiO2 = 1.0)). Finding CBFV(MCA) unchanged during hyperoxia is consistent with the present study's unchanged rCBF in parietal and left frontal gray matter. In these fronto-parietal regions predominantly fed by the middle cerebral artery, the vasoconstrictor effect of oxygen was probably counteracted by increased perfusion of foci of neuronal activity controlling general behavior and arousal. PMID:12413599

  17. Quantification of serial changes in cerebral blood volume and metabolism in patients with recurrent glioblastoma undergoing antiangiogenic therapy

    International Nuclear Information System (INIS)

    Highlights: • Antiangiogenic therapy can lead to a decreased in CBV in normal brain tissue. • Responding and pseudoresponding lesions to AAT showed a similar CBV decrease. • Cho and NAA allowed for a distinction of responding and pseudoresponding lesions. • Cr ratios are not suited for evaluation of antiangiogenic therapy response. • Responders to AAT may have an increased risk for remote progression of the GBM. - Abstract: Objectives: To evaluate the usefulness of quantitative advanced magnetic resonance imaging (MRI) methods for assessment of antiangiogenic therapy (AAT) response in recurrent glioblastoma multiforme (GBM). Methods: Eighteen patients with recurrent GBM received bevacizumab and 18 patients served as control group. Baseline MRI and two follow-up examinations were acquired every 3–5 months using dynamic susceptibility-weighted contrast (DSC) perfusion MRI and 1H-MR spectroscopic imaging (1H-MRSI). Maps of absolute cerebral blood volume (aCBV) were coregistered with choline (Cho) and N-acetyl-aspartate (NAA) concentrations and compared to usually used relative parameters as well as controls. Results: Perfusion significantly decreased in responding and pseudoresponding GBMs but also in normal appearing brain after AAT onset. Cho and NAA concentrations were superior to Cr-ratios in lesion differentiation and showed a clear gap between responding and pseudoresponding lesions. Responders to AAT exceptionally frequently (6 out of 8 patients) showed remote GBM progression. Conclusions: Quantification of CBV reveals changes in normal brain perfusion due to AAT, which were not described so far. DSC perfusion MRI seems not to be suitable for differentiation between response and pseudoresponse to AAT. However, absolute quantification of brain metabolites may allow for distinction due to a clear gap at 6–9 months after therapy onset

  18. Do Sustained Lung Inflations during Neonatal Resuscitation Affect Cerebral Blood Volume in Preterm Infants? A Randomized Controlled Pilot Study.

    Directory of Open Access Journals (Sweden)

    Bernhard Schwaberger

    Full Text Available Sustained lung inflations (SLI during neonatal resuscitation may promote alveolar recruitment in preterm infants. While most of the studies focus on respiratory outcome, the impact of SLI on the brain hasn't been investigated yet.Do SLI affect cerebral blood volume (CBV in preterm infants?Preterm infants of gestation 28 weeks 0 days to 33 weeks 6 days with requirement for respiratory support (RS were included in this randomized controlled pilot trial. Within the first 15 minutes after birth near-infrared spectroscopy (NIRS measurements using 'NIRO-200-NX' (Hamamatsu, Japan were performed to evaluate changes in CBV and cerebral tissue oxygenation. Two groups were compared based on RS: In SLI group RS was given by applying 1-3 SLI (30 cmH2O for 15 s continued by respiratory standard care. Control group received respiratory standard care only.40 infants (20 in each group with mean gestational age of 32 weeks one day (±2 days and birth weight of 1707 (±470 g were included. In the control group ΔCBV was significantly decreasing, whereas in SLI group ΔCBV showed similar values during the whole period of 15 minutes. Comparing both groups within the first 15 minutes ΔCBV showed a tendency toward different overall courses (p = 0.051.This is the first study demonstrating an impact of SLI on CBV. Further studies are warranted including reconfirmation of the present findings in infants with lower gestational age. Future investigations on SLI should not only focus on respiratory outcome but also on the consequences on the developing brain.German Clinical Trials Register DRKS00005161 https://drks-neu.uniklinik-freiburg.de/drks_web/setLocale_EN.do.

  19. Added value of lung perfused blood volume images using dual-energy CT for assessment of acute pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Kunihiro, Yoshie [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru [Department of Radiology, Yamaguchi Grand Medical Center, Oosaki 77, Hofu, Yamaguchi 747-8511 (Japan); Nomura, Takafumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Kudomi, Shohei; Yonezawa, Teppei [Department of Radiology, Yamaguchi University Hospital, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Suga, Kazuyoshi [Department of Radiology, St. Hills Hospital, Imamurakita 3-7-18, Ube, Yamaguchi 755-0155 (Japan); Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan)

    2015-01-15

    Purpose: To investigate the added value of lung perfused blood volume (LPBV) using dual-energy CT for the evaluation of intrapulmonary clot (IPC) in patients suspected of having acute pulmonary embolism (PE). Materials and methods: Institutional review board approval was obtained for this retrospective study. Eighty-three patients suspected of having PE who underwent CT pulmonary angiography (CTPA) using a dual-energy technique were enrolled in this study. Two radiologists who were blinded retrospectively and independently reviewed CTPA images alone and the combined images with color-coded LPBV over a 4-week interval, and two separate sessions were performed with a one-month interval. Inter- and intraobserver variability and diagnostic accuracy were evaluated for each reviewer with receiver operating characteristic (ROC) curve analysis. Results: Values for inter- and intraobserver agreement, respectively, were better for CTPA combined with LPBV (ICC = 0.847 and 0.937) than CTPA alone (ICC = 0.748 and 0.861). For both readers, diagnostic accuracy (area under the ROC curve [A{sub z}]) were also superior, when CTPA alone (A{sub z} = 0.888 [reader 1] and 0.912 [reader 2]) was compared with that after the combination with LPBV images (A{sub z} = 0.966 [reader 1] and 0.959 [reader 2]) (p < 0.001). However, A{sub z} values of both images might not have significant difference in statistics, because A{sub z} value of CTPA alone was high and 95% confidence intervals overlapped in both images. Conclusion: Addition of dual-energy perfusion CT to CTPA improves detection of peripheral IPCs with better interobserver agreement.

  20. Quantification of serial changes in cerebral blood volume and metabolism in patients with recurrent glioblastoma undergoing antiangiogenic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Stadlbauer, Andreas, E-mail: andi@nmr.at [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria); Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen (Germany); Department of Radiology and Nuclear Medicine, Medical University Vienna, Währinger Gürtel 18-20, A-1097 Vienna (Austria); Pichler, Petra [First Department of Internal Medicine, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Poelten (Austria); Karl, Marianne [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria); Brandner, Sebastian [Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen (Germany); Lerch, Claudia [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria); Renner, Bertold [Institute of Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nürnberg, Erlangen (Germany); Heinz, Gertraud [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria)

    2015-06-15

    Highlights: • Antiangiogenic therapy can lead to a decreased in CBV in normal brain tissue. • Responding and pseudoresponding lesions to AAT showed a similar CBV decrease. • Cho and NAA allowed for a distinction of responding and pseudoresponding lesions. • Cr ratios are not suited for evaluation of antiangiogenic therapy response. • Responders to AAT may have an increased risk for remote progression of the GBM. - Abstract: Objectives: To evaluate the usefulness of quantitative advanced magnetic resonance imaging (MRI) methods for assessment of antiangiogenic therapy (AAT) response in recurrent glioblastoma multiforme (GBM). Methods: Eighteen patients with recurrent GBM received bevacizumab and 18 patients served as control group. Baseline MRI and two follow-up examinations were acquired every 3–5 months using dynamic susceptibility-weighted contrast (DSC) perfusion MRI and {sup 1}H-MR spectroscopic imaging ({sup 1}H-MRSI). Maps of absolute cerebral blood volume (aCBV) were coregistered with choline (Cho) and N-acetyl-aspartate (NAA) concentrations and compared to usually used relative parameters as well as controls. Results: Perfusion significantly decreased in responding and pseudoresponding GBMs but also in normal appearing brain after AAT onset. Cho and NAA concentrations were superior to Cr-ratios in lesion differentiation and showed a clear gap between responding and pseudoresponding lesions. Responders to AAT exceptionally frequently (6 out of 8 patients) showed remote GBM progression. Conclusions: Quantification of CBV reveals changes in normal brain perfusion due to AAT, which were not described so far. DSC perfusion MRI seems not to be suitable for differentiation between response and pseudoresponse to AAT. However, absolute quantification of brain metabolites may allow for distinction due to a clear gap at 6–9 months after therapy onset.

  1. The value of maximal blood flow volume on duplex ultrasonography for the diagnosis of arteriogenic erectile dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Ku, Ja Hyeon [Soonchunhyang University School of Medicine, Chunan (Korea, Republic of); Song, Yun Seob; Kim, Min Eui; Park, Young Ho; Lee, Hye Kyoung [Seoul and Military Manpower Administration, Taejeon (Korea, Republic of)

    2001-03-15

    To evaluate the usefulness of maximal blood flow volume (MBFV) measured by duplex ultrasonography (US) compared with penile tumescence measured by RigiScan in the diagnosis of arteriogenic erectile dysfunction (ED). This study included twenty six patients who performed both RigiScan and duplex US after intracorporeal injection of Prostaglandin EL. We measured tumescences of penile tip and base using RigiScan and maximal arterial diameter (MAD) and peak systolic velocity (PSV) using a 7 MHz color Doppler unit. MBFV was defined as (MAD/2){sup 2} X pi X PSV. Based on normal value, we compared MAD and MBFV, and PSV and MBFV and the correlations of each measurements were evaluated with Spearman's correlation analysis. The level of significance was P<0.05. The results between MAD and MBFV, and PSV ad MBFV based on normal values were similar, respectively. Tumescences of penile tip and base were significantly correlated with MAD (r=0.409, r=0.52, p<0.05), and PSV (r=0.565, r=0.396, p<0.05). MBFV was also significantly correlated with tumescences od penile tip and base (r=0.502, r=0.563, p<0.05). In 4 patients with abnormal MAD and normal PSV, 3 had abnormal MBFV and 1 had normal MBFV. All 3 patients with abnormal MBFV had abnormal penile tumescence and 1 patients with normal MBFV had normal tumescence. One patients with normal MAD and abnormal PSV had abnormal MBFV and penile tumescence. In our study, MBFV was accurate in the diagnosis of arteriogenic ED. Moreover, MBFV was usefulness in the diagnosis of arteriogenic ED as it could explain the case where MAD and PSV are not accoded.

  2. The value of maximal blood flow volume on duplex ultrasonography for the diagnosis of arteriogenic erectile dysfunction

    International Nuclear Information System (INIS)

    To evaluate the usefulness of maximal blood flow volume (MBFV) measured by duplex ultrasonography (US) compared with penile tumescence measured by RigiScan in the diagnosis of arteriogenic erectile dysfunction (ED). This study included twenty six patients who performed both RigiScan and duplex US after intracorporeal injection of Prostaglandin EL. We measured tumescences of penile tip and base using RigiScan and maximal arterial diameter (MAD) and peak systolic velocity (PSV) using a 7 MHz color Doppler unit. MBFV was defined as (MAD/2)2 X π X PSV. Based on normal value, we compared MAD and MBFV, and PSV and MBFV and the correlations of each measurements were evaluated with Spearman's correlation analysis. The level of significance was P<0.05. The results between MAD and MBFV, and PSV ad MBFV based on normal values were similar, respectively. Tumescences of penile tip and base were significantly correlated with MAD (r=0.409, r=0.52, p<0.05), and PSV (r=0.565, r=0.396, p<0.05). MBFV was also significantly correlated with tumescences od penile tip and base (r=0.502, r=0.563, p<0.05). In 4 patients with abnormal MAD and normal PSV, 3 had abnormal MBFV and 1 had normal MBFV. All 3 patients with abnormal MBFV had abnormal penile tumescence and 1 patients with normal MBFV had normal tumescence. One patients with normal MAD and abnormal PSV had abnormal MBFV and penile tumescence. In our study, MBFV was accurate in the diagnosis of arteriogenic ED. Moreover, MBFV was usefulness in the diagnosis of arteriogenic ED as it could explain the case where MAD and PSV are not accoded.

  3. Relative cerebral blood volume measurements of low-grade gliomas predict patient outcome in a multi-institution setting

    International Nuclear Information System (INIS)

    Background/purpose: The prognostic value of defining subcategories of gliomas is still controversial. This study aims to determine the utility of relative cerebral blood volume (rCBV) in predicting clinical response in patients with low-grade glioma at multiple institutions. Materials and methods: Sixty-nine patients were studied with dynamic susceptibility contrast-enhanced perfusion MRI at two institutions. The pathologic diagnoses of the low-grade gliomas were 34 astrocytomas, 20 oligodendroglioma, 9 oligoastrocytomas, 1 ganglioglioma and 5 with indeterminate histology. Wilcoxon tests were used to compare patients in different response categories with respect to baseline rCBV. Kaplan-Meier curve and log-rank tests were used to predict the association of rCBV with time to progression. Results: At both institutions, patients with an adverse event (progressive disease or death) had a significantly higher baseline rCBV than those without (complete response or stable disease) (p value = 0.0138). The odds ratio for detecting an adverse event when using rCBV was 1.87 (95% confidence interval: 1.14-3.08). rCBV was significantly negatively associated with time to progression (p = 0.005). The median time to progression among subjects with rCBV > 1.75 was 365 days, while there was 95% confidence that the median time to progression was at least 889 days among subjects with rCBV < 1.75. Conclusion: Our study suggests not only that rCBV measurements correlate well with time to progression or death, but also that the findings can be replicated across institutions, which supports the application of rCBV as an adjunct to pathology in predicting glioma biology.

  4. Central role for sodium in the pathogenesis of blood pressure changes independent of angiotensin, aldosterone and catecholamines in type 1 (insulin-dependent) diabetes mellitus

    DEFF Research Database (Denmark)

    Feldt-Rasmussen, B; Mathiesen, E R; Deckert, T; Giese, J; Christensen, N J; Bent-Hansen, L; Nielsen, M D

    1987-01-01

    We studied 73 Type 1 (insulin-dependent) diabetic patients, 18 to 50 years of age, with a diabetes duration of more than five years. Group 1: normal urinary albumin excretion below 30 mg per 24 h (n = 19); group 2: microalbuminuria, 30-300 mg per 24 h (n = 36); and group 3: diabetic nephropathy...... = 0.41, p less than 0.01). Extracellular volume was increased in patients (p less than 0.05), whereas plasma volume wasnormal. Supine serum angiotensin II was suppressed in the patients (p less than 0.001). A negative correlation was found between mean blood pressure and supine serum aldosterone (n...

  5. Cryopreservation of blood mononuclear leukocytes and stem cells suspended in a large fluid volume. A preclinical model for a blood stem cell bank.

    Science.gov (United States)

    Fliedner, T M; Körbling, M; Calvo, W; Bruch, C; Herbst, E

    1977-09-29

    It was the purpose of this study to establish and evaluate a freezing-and-thawing method for preservation of hemopoietic stem cells from the peripheral blood. Blood leukocytes collected by means of an IBM Blood-Cell-Separator were frozen in plastic bags using 10% DMSO and controlled cooling rates. Thawing was performed rapidly, and DMSO was diluted and removed prior to the in-vitro and in-vivo assays. The mean recovery of mononuclear cells collected from 82 leukaphereses was 86%. To assess the recovery of cryopreserved hemopoietic stem cells, the soft agar culture method adapted for the dog was used. There was no significant difference in the CFUc recovery per 1 X 10(6) mononuclear cells or in per leukapheresis after different cryopreservation times (1--6 and 7--27 months). To evaluate the hemopoietic repopulation capability of cryopreserved blood stem cells, leukapheresis-derived leukocytes were transfused into 1200 R whole body x-irradiated dogs. The hemopoietic repopulation pattern at day 10 after transfusion of comparable numbers of fresh or frozen leukocytes was not significantly different, as measured in bone marrow smears and sections and by granulocyte concentration in the peripheral blood. PMID:912104

  6. A new method to study changes in microvascular blood volume in muscle and adipose tissue: Real time imaging in humans and rat

    DEFF Research Database (Denmark)

    Sjøberg, Kim Anker; Rattigan, Stephen; Hiscock, Natalie J;

    2011-01-01

    We employed and evaluated a new application of contrast enhanced ultrasound for real time imaging of changes in microvascular blood volume (MVB) in tissues in females, males and rat. Continuous real time imaging was performed using contrast enhanced ultrasound to quantify infused gas filled micro...... real time imaging the method has wide applications for determining MBV in different organs during various physiological or pathophysiological conditions....

  7. Bidirectional Contrast agent leakage correction of dynamic susceptibility contrast (DSC)-MRI improves cerebral blood volume estimation and survival prediction in recurrent glioblastoma treated with bevacizumab.

    OpenAIRE

    Ab, KL; Boxerman, JL; Lai, A.; Nghiemphu, PL; Pope, WB; Cloughesy, TF; Ellingson, BM

    2016-01-01

    To evaluate a leakage correction algorithm for T1 and T2* artifacts arising from contrast agent extravasation in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) that accounts for bidirectional contrast agent flux and compare relative cerebral blood volume (CBV) estimates and overall survival (OS) stratification from this model to those made with the unidirectional and uncorrected models in patients with recurrent glioblastoma (GBM).We determined median rCBV within contras...

  8. Carbogen Breathing Differentially Enhances Blood Plasma Volume and 5-Fluorouracil Uptake in Two Murine Colon Tumor Models with a Distinct Vascular Structure

    Directory of Open Access Journals (Sweden)

    Hanneke W.M. van Laarhoven

    2006-06-01

    Full Text Available For the systemic treatment of colorectal cancer, 5-fluorouracil (FU-based chemotherapy is the standard. However, only a subset of patients responds to chemotherapy. Breathing of carbogen (95% O2 and 5% CO2 may increase the uptake of FU through changes in tumor physiology. This study aims to monitor in animal models in vivo the effects of carbogen breathing on tumor blood plasma volume, pH, and energy status, and on FU uptake and metabolism in two colon tumor models C38 and C26a, which differ in their vascular structure and hypoxic status. Phosphorus-31 magnetic resonance spectroscopy (MRS was used to assess tumor pH and energy status, and fluorine-19 MRS was used to follow FU uptake and metabolism. Advanced magnetic resonance imaging methods using ultrasmall particles of iron oxide were performed to assess blood plasma volume. The results showed that carbogen breathing significantly decreased extracellular pH and increased tumor blood plasma volume and FU uptake in tumors. These effects were most significant in the C38 tumor line, which has the largest relative vascular area. In the C26a tumor line, carbogen breathing increased tumor growth delay by FU. In this study, carbogen breathing also enhanced systemic toxicity by FU.

  9. Impact of 4D-18FDG-PET/CT imaging on target volume delineation in SBRT patients with central versus peripheral lung tumors. Multi-reader comparative study

    International Nuclear Information System (INIS)

    Purpose: Evaluation of the effect of co-registered 4D-18FDG-PET/CT for SBRT target delineation in patients with central versus peripheral lung tumors. Methods: Analysis of internal target volume (ITV) delineation of central and peripheral lung lesions in 21 SBRT-patients. Manual delineation was performed by 4 observers in 2 contouring phases: on respiratory gated 4DCT with diagnostic 3DPET available aside (CT-ITV) and on co-registered 4DPET/CT (PET/CT-ITV). Comparative analysis of volumes and inter-reader agreement. Results: 11 cases of peripheral and 10 central lesions were evaluated. In peripheral lesions, average CT-ITV was 6.2 cm3 and PET/CT-ITV 8.6 cm3, resembling a mean change in hypothetical radius of 2 mm. For both CT-ITVs and PET/CT-ITVs inter reader agreement was good and unchanged (0.733 and 0.716; p = 0.58). All PET/CT-ITVs stayed within the PTVs derived from CT-ITVs. In central lesions, average CT-ITVs were 42.1 cm3, PET/CT-ITVs 44.2 cm3, without significant overall volume changes. Inter-reader agreement improved significantly (0.665 and 0.750; p < 0.05). 2/10 PET/CT-ITVs exceeded the PTVs derived from CT-ITVs by >1 ml in average for all observers. Conclusion: The addition of co-registered 4DPET data to 4DCT based target volume delineation for SBRT of centrally located lung tumors increases the inter-observer agreement and may help to avoid geographic misses

  10. Cerebral blood volume calculated by dynamic susceptibility contrast-enhanced perfusion MR imaging: preliminary correlation study with glioblastoma genetic profiles.

    Directory of Open Access Journals (Sweden)

    Inseon Ryoo

    Full Text Available PURPOSE: To evaluate the usefulness of dynamic susceptibility contrast (DSC enhanced perfusion MR imaging in predicting major genetic alterations in glioblastomas. MATERIALS AND METHODS: Twenty-five patients (M:F = 13∶12, mean age: 52.1±15.2 years with pathologically proven glioblastoma who underwent DSC MR imaging before surgery were included. On DSC MR imaging, the normalized relative tumor blood volume (nTBV of the enhancing solid portion of each tumor was calculated by using dedicated software (Nordic TumorEX, NordicNeuroLab, Bergen, Norway that enabled semi-automatic segmentation for each tumor. Five major glioblastoma genetic alterations (epidermal growth factor receptor (EGFR, phosphatase and tensin homologue (PTEN, Ki-67, O6-methylguanine-DNA methyltransferase (MGMT and p53 were confirmed by immunohistochemistry and analyzed for correlation with the nTBV of each tumor. Statistical analysis was performed using the unpaired Student t test, ROC (receiver operating characteristic curve analysis and Pearson correlation analysis. RESULTS: The nTBVs of the MGMT methylation-negative group (mean 9.5±7.5 were significantly higher than those of the MGMT methylation-positive group (mean 5.4±1.8 (p = .046. In the analysis of EGFR expression-positive group, the nTBVs of the subgroup with loss of PTEN gene expression (mean: 10.3±8.1 were also significantly higher than those of the subgroup without loss of PTEN gene expression (mean: 5.6±2.3 (p = .046. Ki-67 labeling index indicated significant positive correlation with the nTBV of the tumor (p = .01. CONCLUSION: We found that glioblastomas with aggressive genetic alterations tended to have a high nTBV in the present study. Thus, we believe that DSC-enhanced perfusion MR imaging could be helpful in predicting genetic alterations that are crucial in predicting the prognosis of and selecting tailored treatment for glioblastoma patients.

  11. Rising trends of HCV infection over a period of 4 years among blood donors in central India: A retrospective study

    Directory of Open Access Journals (Sweden)

    Alok Kumar

    2010-10-01

    Full Text Available Objective: The aim of the study was to find out the sero-prevalence of Hepatitis C infection among blood donors. Materials and Methods: All collected blood bags were screened for anti-hepatitis C virus antibodies (HCV Ab; MicroELISA 3rd generation, J. Mitra during the study period of 4 years and data were analyzed. Results: A total of 28621 blood donors were screened for transfusion transmissible infections (TTIs in which 80 donors were positive for Hepatitis C infection, constituted 11% of total sero-reactive donors. In 2009, only 10 cases were sero-reactive while in 2012, 36 cases were sero-reactive for Hepatitis C infection. Conclusions: Hepatitis C infection among blood donors are in rising trends in this study area. Voluntary donors are safer than replacement donors as they have very low sero-prevalence. As these blood donors represent the highly selective community of a general population in most of the countries. So the actual sero-prevalence of hepatitis C infection may be more in the general population. Promoting HCV screening, voluntary blood donation, diagnosis and treatment among blood donors are very important measures to control the transmission of HCV infection, decrease sero-reactive cases and ensure safe blood collection.

  12. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 4. Commercial and pilot plant cost data. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    This volume of the advanced central receiver final report presents the cost data using the cost breakdown structure identified in the preliminary specification. Cost summaries are presented in the following sections for the 100-MWe and 281-MWe commercial plant and a 10-MWe pilot plant. Cost substantiation data for this volume are presented in the appendices. Other cost summary data include Nth plant data for the 100-MWe and 281-MWe commercial plants, and a summary for the alternative concept air-rock storage system. The main description of the plant costing technique occurs as part of Section II for the 100-MWe baseline concept.

  13. [Interpretation and use of routine pulmonary function tests: Spirometry, static lung volumes, lung diffusion, arterial blood gas, methacholine challenge test and 6-minute walk test].

    Science.gov (United States)

    Bokov, P; Delclaux, C

    2016-02-01

    Resting pulmonary function tests (PFT) include the assessment of ventilatory capacity: spirometry (forced expiratory flows and mobilisable volumes) and static volume assessment, notably using body plethysmography. Spirometry allows the potential definition of obstructive defect, while static volume assessment allows the potential definition of restrictive defect (decrease in total lung capacity) and thoracic hyperinflation (increase in static volumes). It must be kept in mind that this evaluation is incomplete and that an assessment of ventilatory demand is often warranted, especially when facing dyspnoea: evaluation of arterial blood gas (searching for respiratory insufficiency) and measurement of the transfer coefficient of the lung, allowing with the measurement of alveolar volume to calculate the diffusing capacity of the lung for CO (DLCO: assessment of alveolar-capillary wall and capillary blood volume). All these pulmonary function tests have been the subject of an Americano-European Task force (standardisation of lung function testing) published in 2005, and translated in French in 2007. Interpretative strategies for lung function tests have been recommended, which define abnormal lung function tests using the 5th and 95th percentiles of predicted values (lower and upper limits of normal values). Thus, these recommendations need to be implemented in all pulmonary function test units. A methacholine challenge test will only be performed in the presence of an intermediate pre-test probability for asthma (diagnostic uncertainty), which is an infrequent setting. The most convenient exertional test is the 6-minute walk test that allows the assessment of walking performance, the search for arterial desaturation and the quantification of dyspnoea complaint. PMID:26657268

  14. Susceptibility Contrast Magnetic Resonance Imaging Determination of Fractional Tumor Blood Volume: A Noninvasive Imaging Biomarker of Response to the Vascular Disrupting Agent ZD6126

    International Nuclear Information System (INIS)

    Purpose: To assess tumor fractional blood volume (ξ), determined in vivo by susceptibility contrast magnetic resonance imaging (MRI) as a noninvasive imaging biomarker of tumor response to the vascular disrupting agent ZD6126. Methods and Materials: The transverse MRI relaxation rate R2* of rat GH3 prolactinomas was quantified prior to and following injection of 2.5 mgFe/kg feruglose, an ultrasmall superparamagnetic iron oxide intravascular contrast agent, and ξ (%) was determined from the change in R2*. The rats were then treated with either saline or 50 mg/kg ZD6126, and ξ measured again 24 hours later. Following posttreatment MRI, Hoechst 33342 (15 mg/kg) was administered to the rats and histological correlates from composite images of tumor perfusion and necrosis sought. Results: Irrespective of treatment, tumor volume significantly increased over 24 hours. Saline-treated tumors showed no statistically significant change in ξ, whereas a significant (p = 0.002) 70% reduction in ξ of the ZD6126-treated cohort was determined. Hoechst 33342 uptake was associated with viable tumor tissue and was significantly (p = 0.004) reduced and restricted to the rim of the ZD6126-treated tumors. A significant positive correlation between posttreatment ξ and Hoechst 33342 uptake was obtained (r = 0.83, p = 0.002), providing validation of the MRI-derived measurements of fractional tumor blood volume. Conclusions: These data clearly highlight the potential of susceptibility contrast MRI with ultrasmall superparamagnetic iron oxide contrast agents to provide quantitative imaging biomarkers of fractional tumor blood volume at high spatial resolution to assess tumor vascular status and response to vascular disrupting agents

  15. Rising trends of HCV infection over a period of 4 years among blood donors in central India: A retrospective study

    OpenAIRE

    Alok Kumar; Satish Sharma,; Narayan Ingole; Nitin Gangane

    2010-01-01

    Objective: The aim of the study was to find out the sero-prevalence of Hepatitis C infection among blood donors. Materials and Methods: All collected blood bags were screened for anti-hepatitis C virus antibodies (HCV Ab; MicroELISA 3rd generation, J. Mitra) during the study period of 4 years and data were analyzed. Results: A total of 28621 blood donors were screened for transfusion transmissible infections (TTIs) in which 80 donors were positive for Hepatitis C infection, constituted 11% of...

  16. Isolation of mesenchymal stromal/stem cells from small-volume umbilical cord blood units that do not qualify for the banking system.

    Science.gov (United States)

    Yoshioka, Satoshi; Miura, Yasuo; Iwasa, Masaki; Fujishiro, Aya; Yao, Hisayuki; Miura, Masako; Fukuoka, Masaaki; Nakagawa, Yoko; Yokota, Asumi; Hirai, Hideyo; Ichinohe, Tatsuo; Takaori-Kondo, Akifumi; Maekawa, Taira

    2015-08-01

    The clinical application of mesenchymal stromal/stem cells (MSCs) has been extensively explored. In this study, we examined the availability of freshly donated umbilical cord blood (UCB) units that do not qualify for the Japanese banking system for transplantation because of their small volume as a source of MSCs. Forty-five UCB units were used. The median volume of each UCB unit and number of nucleated cells per unit were 40 mL and 5.39 × 10(8), respectively. MSCs were successfully isolated from 18 of 45 units (40 %). The MSC isolation rate was not affected by cell processing method or the interval between delivery and cell processing. The volume of the UCB unit and the mononuclear cell count were predictive factors of the MSC isolation rate. MSCs were effectively isolated by selecting UCB units with a volume of ≥54 mL and containing ≥1.28 × 10(8) mononuclear cells, yielding a MSC isolation rate of >70 %. UCB-derived MSCs were similar to bone marrow-derived MSCs in terms of their morphology, surface marker expression, and differentiation potential, apart from adipogenesis. Our data indicate that UCB units that are currently discarded due to inadequate volume should be reconsidered as a source of MSCs using the well-established UCB banking system. PMID:26121953

  17. Iodine status and its correlations with age, blood pressure, and thyroid volume in South Indian women above 35 years of age (Amrita Thyroid Survey

    Directory of Open Access Journals (Sweden)

    Vadayath Usha Menon

    2011-01-01

    Full Text Available Background: Thyroid disorders are more commonly seen among females and the prevalence increases with age. There is no population data from India focusing on iodine levels and their correlations with thyroid volume and other factors in adult women. Aim: This study was designed to establish the iodine status and its relation with various factors including thyroid volume measured by ultrasound among the females of Kerala. Materials and Methods: This was a cross sectional house to house survey among the females above 35 years of age in a randomly selected urban area in Cochin Corporation, Kerala State, India. Selected subjects were interviewed, examined and blood and urine tests were done. Thyroid volume was calculated using ultrasound. Results: Among the 508 subjects who participated in the checkup, 471 subjects were included for analysis. Mean age was 50.3 + 10.7 years and 53.2% were postmenopausal. A total of 98% of the subjects were using iodized salt and median urinary iodine excretion (UIE was 162.6 mcg/l. UIE had negative correlation with age and systolic blood pressure (BP, but had no correlation with thyroid volume (TV, thyroid nodularity, free thyroxine 4 (FT4, thyroid stimulating hormone (TSH or anti thyroid peroxidase (TPO levels. Iodine deficiency was more commonly seen in subjects with hypertension and also among postmenopausal females. Conclusions: This study showed that females > 35 years were iodine sufficient, though one third of the subjects had UIE levels less than the recommended level. Iodine levels had significant negative correlation with age and systolic BP and no correlation with thyroid volume or biochemical parameters. Iodine deficiency was significantly higher in subjects with new and known hypertension and this relation merits further evaluation.

  18. Dynamic contrast-enhanced x-ray CT measurement of cerebral blood volume in a rabbit tumor model

    Science.gov (United States)

    Cenic, Aleksa; Lee, Ting-Yim; Craen, Rosemary A.; Gelb, Adrian W.

    1998-07-01

    Cerebral blood volume (CBV) is a major determinant of intracranial pressure (ICP). Hyperventilation is commonly employed to reduce raised ICP (e.g. in brain tumour patients) presumably through its effect on CBV. With the advent of slip- ring CT scanners, dynamic contrast-enhanced imaging allows for the measurement of CBV with high spatial resolution. Using a two-compartment model to characterize the distribution of X- ray contrast agent in the brain, we have developed a non- equilibrium CT method to measure CBV in normal and pathological regions. We used our method to investigate the effect of hyperventilation on CBV during propofol anaesthesia in rabbits with implanted brain tumours. Eight New Zealand White rabbits with implanted VX2 carcinoma brain tumours were studied. For each rabbit, regional CBV measurements were initially made at normocapnia (PaCO2 40 mmHg) and then at hyperventilation (PaCO2 25 mmHg) during propofol anaesthesia. The head was positioned such that a coronal image through the brain incorporated a significant cross-section of the brain tumour as well as a radial artery in a forelimb. Images at the rate of 1 per second were acquired for 2 minutes as Omnipaque 300 (1.5 ml/kg rabbit weight) was injected via a peripheral vein. In these CT images, regions of interest in the brain tissue (e.g. tumour, contra-lateral normal, and peri-tumoural) and the radial artery were drawn. For each region, the mean CT number in pre-contrast images was subtracted from the mean CT number in post-contrast images to produce either the tissue contrast concentration curve, or the arterial contrast concentration curve. Using our non- equilibrium analysis method based on a two-compartment model, regional CBV values were determined from the measured contrast concentration curves. From our study, the mean CBV values [+/- SD] in the tumour, peri-tumoural, and contra-lateral normal regions during normocapnia were: 5.47 plus or minus 1.97, 3.28 plus or minus 1.01, and 1

  19. Two-modality γ detection of blood volume by camera imaging and nonimaging stethoscope for kinetic studies of cardiovascular control in nuclear medicine

    Science.gov (United States)

    Eclancher, Bernard; Chambron, Jacques; Dumitresco, Barbu; Karman, Miklos; Pszota, Agnes; Simon, Atilla; Didon-Poncelet, Anna; Demangeat, Jean

    2002-04-01

    The quantification of rapid hemodynamic reactions to wide and slow breathing movements has been performed, by two modalities (gamma) -left ventriculography of 99mTc-labeled blood volume, in anterior oblique incidence on standing and even exercising healthy volunteers and cardiac patients. A highly sensitive stethoscope delivered whole (gamma) -counts acquired at 30 msec intervals in a square field of view including the left ventricle, in a one dimensional low resolution imaging mode for beat to beat analysis. A planar 2D (gamma) -camera imaging of the same cardiac area was then performed without cardiac gating for alternate acquisitions during deep inspiration and deep expiration, completed by a 3D MRI assessment of the stethoscope detection field. Young healthy volunteers displayed wide variations of diastolic times and stroke volumes, as a result of enhanced baroreflex control, together with +/- 16% variations of the stethoscope's background blood volume counts. Any of the components of these responses were shifted, abolished or even inverted as a result of either obesity, hypertension, aging or cardiac pathologies. The assessment of breathing control of the cardiovascular system by the beat to beat (gamma) -ventriculography combined with nuclear 2D and 3D MRI imaging is a kinetic method allowing the detection of functional anomalies in still ambulatory patients.

  20. Dual energy CT pulmonary blood volume assessment in acute pulmonary embolism - correlation with D-dimer level, right heart strain and clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Ralf W.; Frellesen, Claudia; Schell, Boris; Lehnert, Thomas; Jacobi, Volkmar; Vogl, Thomas J.; Kerl, J.M. [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Renker, Matthias [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Medical University of South Carolina, Heart and Vascular Center, Ashley River Tower, Charleston, SC (United States); Ackermann, Hanns [Clinic of the Goethe University, Department of Biostatistics and Mathematical Modelling, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Heart and Vascular Center, Ashley River Tower, Charleston, SC (United States)

    2011-09-15

    To investigate the role of perfusion defect (PD) size on dual energy CT pulmonary blood volume assessment as predictor of right heart strain and patient outcome and its correlation with d-dimer levels in acute pulmonary embolism (PE). 53 patients with acute PE who underwent DECT pulmonary angiography were retrospectively analyzed. Pulmonary PD size caused by PE was measured on DE iodine maps and quantified absolutely (VolPD) and relatively to the total lung volume (RelPD). Signs of right heart strain (RHS) on CT were determined. Information on d-dimer levels and readmission for recurrent onset of PE and death was collected. D-dimer level was mildly (r = 0.43-0.47) correlated with PD size. Patients with RHS had significantly higher VolPD (215 vs. 73 ml) and RelPD (9.9 vs. 2.9%) than patients without RHS (p < 0.003). There were 2 deaths and 1 readmission due of PE in 18 patients with >5% RelPD, while no such events were found for patients with <5% RelPD. Pulmonary blood volume on DECT in acute PE correlates with RHS and appears to be a predictor of patient outcome in this pilot study. (orig.)

  1. Fixed-Combination Olmesartan/Amlodipine Was Superior to Perindopril + Amlodipine in Reducing Central Systolic Blood Pressure in Hypertensive Patients With Diabetes.

    Science.gov (United States)

    Ruilope, Luis M

    2016-06-01

    This post hoc analysis from the Sevikar Compared to the Combination of Perindopril Plus Amlodipine on Central Arterial Blood Pressure in Patients With Moderate-to-Severe Hypertension (SEVITENSION) study assessed the efficacy and tolerability of olmesartan (OLM) and amlodipine (AML) in reducing central systolic blood pressure (CSBP) compared with perindopril (PER) plus AML in hypertensive patients with type 2 diabetes. Patients were randomized to OLM/AML 40/10 mg or PER/AML 8/10 mg for 24 weeks. The primary efficacy endpoint was the absolute change in CSBP from baseline to week 24, which was greater with OLM/AML (-13.72±1.14 mm Hg) compared with PER/AML (-10.21±1.11 mm Hg). The between-group difference was -3.51±1.60 mm Hg (95% confidence interval, -6.66 to -0.36 mm Hg) and was within the noninferiority margin (2 mm Hg) as well as the superiority margin (0 mm Hg). In addition, OLM/AML was associated with a higher proportion of patients achieving blood pressure normalization. In hypertensive patients with diabetes, the fixed-dose combination of OLM/AML was superior to PER/AML in reducing CSBP, as well as other secondary endpoints. PMID:26395174

  2. Combined SPECT imaging of regional cerebral blood flow (99mTc-hexamethyl-propyleneamine oxime, HMPAO) and blood volume (99mTc-RBC) to assess regional cerebral perfusion reserve in patients with cerebrovascular disease

    International Nuclear Information System (INIS)

    In 53 patients with cerebrovascular disease (CDV), regional cerebral blood flow (CBF) and blood volume (CBV) were imaged by SPECT within one session. Slice division (CBF:CBV) yielded distribution of regional cerebral perfusion reserve (CPR). Semiquantitative evaluation was obtained from manually set ROIs by interhemispherical ratios (for CBF, CBV and CPR), using 2 SD from a normal group (n=10) as a threshold. Sensitivity was 59% for CBF, 94% for CBV and 83% for CPR. Combined sensitivity was 98%. Establishing three constellations for CBF, CBV and CPR, regionally normal CBFs but quantitatively increased CBVs (+69%) and decreased CPRs (-31%) were found in relatively early stages of CVD. Very advanced cases showed decreased CBFs (-65%), CBVs (-40%), CPRs (-49%) and a surrounding penumbra. In 87% (46/53 patients), such rheologically postulated constellations could be demonstrated. We conclude that combined CBF and CBV SPECT, assisted by CPR images, is a promising tool to detect CVD and to assess its individual regional severity. (orig.)

  3. Spatio-temporal characteristics of cerebral blood volume changes in different microvascular compartments evoked by sciatic nerve stimulation in rat somatosensory cortex

    Science.gov (United States)

    Li, Pengcheng; Luo, Qingming; Luo, Weihua; Chen, Shangbin; Chen, Haiying; Zeng, Shaoqun

    2003-10-01

    The spatio-temporal characteristics of changes in cerebral blood volume associated with neuronal activity were investigated in the hindlimb somatosensory cortex of α-chloralose/urethan anesthetized rats (n=10) with optical imaging at 570nm through a thinned skull. Activation of cortex was carried out by electrical stimulation of the contralateral sciatic nerve with 5Hz, 0.3V pulses (0.5ms) for duration of 2s. The stimulation evoked a monophasic optical reflectance decrease at cortical parenchyma and arteries sites rapidly after the onset of stimulation, whereas no similar response was observed at vein compartments. The optical signal changes reached 10% of the peak response 0.70+/-0.32s after stimulation onset and no significant time lag in this 10% start latency time was observed between the response at cortical parenchyma and arteries compartments. The evoked optical reflectance decrease reached the peak (0.25%+/-0.047%)2.66+/-0.61s after the stimulus onset at parenchyma site, 0.40+/-0.20s earlier (P<0.05) than that at arteries site (0.50%+/-0.068% 3.06+/-0.70s). Variable location within the cortical parenchyma and arteries compartment themselves didn"t affect the temporal characteristics of the evoked signal significantly. These results suggest that the sciatic nerve stimulation evokes a local blood volume increase at both capillaries (cortical parenchyma) and arterioles rapidly after the stimulus onset but the evoked blood volume increase in capillaries could not be entirely accounted for by the dilation of arterioles.

  4. Quantification of cellular volume and sub-cellular density fluctuations: comparison of normal peripheral blood cells and circulating tumor cells identified in a breast cancer patient

    Directory of Open Access Journals (Sweden)

    KevinGregoryPhillips

    2012-08-01

    Full Text Available Cancer metastasis, the leading cause of cancer-related deaths, is facilitated in part by the hematogenous transport of circulating tumor cells (CTCs through the vasculature. Clinical studies have demonstrated that CTCs circulate in the blood of patients with metastatic disease across the major types of carcinomas, and that the number of CTCs in peripheral blood is correlated with overall survival in metastatic breast, colorectal, and prostate cancer. While the potential to monitor metastasis through CTC enumeration exists, the basic physical features of CTCs remain ill defined and moreover, the corresponding clinical utility of these physical parameters is unknown. To elucidate the basic physical features of CTCs we present a label-free imaging technique utilizing differential interference contrast (DIC microscopy to measure cell volume and to quantify sub-cellular mass-density variations as well as the size of subcellular constituents from mass-density spatial correlations. DIC measurements were carried out on CTCs identified in a breast cancer patient using the high-definition (HD CTC detection assay. We compared the biophysical features of HD-CTC to normal blood cell subpopulations including leukocytes, platelets, and red blood cells. HD-CTCs were found to possess larger volumes, decreased mass-density fluctuations, and shorter-range spatial density correlations in comparison to leukocytes. Our results suggest that HD-CTCs exhibit biophysical signatures that might be used to potentially aid in their detection and to monitor responses to treatment in a label-free fashion. The biophysical parameters reported here can be incorporated into computational models of CTC-vascular interactions and in vitro flow models to better understand metastasis.

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

    OpenAIRE

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

    2016-01-01

    Background and Objectives Leukocyte and platelet have been found to be associated with metabolic syndrome (MetS). We aimed to determine the usefulness of a novel marker named white blood cell count to mean platelet volume ratio (WMR) for predicting outcomes of non-ST elevation acute coronary syndrome (NSTE-ACS) with or without MetS. Subjects and Methods A total of 331 NSTE-ACS individuals (60±12.5 years, 57.4% male) were enrolled and followed for a median of 24 months. MetS was identified usi...

  6. C-arm computed tomography parenchymal blood volume measurement in evaluation of hepatocellular carcinoma before transarterial chemoembolization with drug eluting beads

    OpenAIRE

    Syha, Roland; Grözinger, Gerd; Grosse, Ulrich; Maurer, Michael; Zender, Lars; Horger, Marius; Nikolaou, Konstantin; Ketelsen, Dominik

    2015-01-01

    Background C-arm computed tomography (CT) guided intervention is an increasingly applied technique in transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). The aim of this study was to analyse the value of parenchymal blood volume (PBV) maps acquired during C-arm CT acquisition, for pre-treatment evaluation and planning of TACE in HCC patients. Methods A total of 64 HCC lesions in 29 patients (median age, 73 years, range, 62–77 years) were included in this retrospective st...

  7. Oxidative mitochondrial DNA damage in peripheral blood mononuclear cells is associated with reduced volumes of hippocampus and subcortical gray matter in chronically HIV-infected patients

    Science.gov (United States)

    Kallianpur, Kalpana J.; Gerschenson, Mariana; Mitchell, Brooks I.; LiButti, Daniel E.; Umaki, Tracie M.; Ndhlovu, Lishomwa C.; Nakamoto, Beau K.; Chow, Dominic C.; Shikuma, Cecilia M.

    2016-01-01

    Cross-sectional relationships were examined between regional brain volumes and mitochondrial DNA (mtDNA) 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral blood mononuclear cells (PBMCs) of 47 HIV patients [mean age 51 years; 81% with HIV RNA ≤50 copies/mL] on combination antiretroviral therapy. The gene-specific DNA damage and repair assay measured mtDNA 8-oxo-dG break frequency. Magnetic resonance imaging was performed at 3 T. Higher mtDNA 8-oxo-dG was associated with lateral ventricular enlargement and with decreased volumes of hippocampus, pallidum, and total subcortical gray matter, suggesting the involvement of systemic mitochondrial-specific oxidative stress in chronic HIV-related structural brain changes and cognitive difficulties. Clarification of the mechanism may provide potential therapeutic targets. PMID:26923169

  8. Epidemiology of hepatitis B virus infection in first-time blood donors in the southwestern region of Goiás, central Brazil

    Directory of Open Access Journals (Sweden)

    Giulena Rosa Leite Cardoso dos Anjos

    2011-02-01

    Full Text Available INTRODUCTION: Little is known about the epidemiology of hepatitis B virus (HBV infection in populations from inner cities, especially in Central Brazil. Thus the objective of this study was to estimate the prevalence of HBV infection, and to analyze the factors associated with HBV infection, in a population of first-time blood donors in the southwestern region of Goiás, Central Brazil. METHODS: A total of 984 individuals were interviewed and gave blood samples to detect serological markers of HBV (HBsAg, anti-HBs, and anti-HBc by enzyme linked immunosorbent assays. RESULTS: An overall prevalence of 6.9% was found for HBV, with constituent prevalence rates of 3.6% and 11.6%, in subjects classified as fit and unfit to donate blood according the epidemiological screening, respectively. Only three individuals were positive for anti-HBs alone, suggesting previous vaccination against HBV. The variables of prior blood transfusion (OR = 2.3, tattoo/piercing (OR = 2.1, illicit drug use (OR = 2.3, sex with a partner with hepatitis (OR = 14.7, and history of sexually transmitted diseases (OR = 2.9 were independently associated with HBV-positivity. These data suggested a low endemicity of hepatitis B in the studied population. CONCLUSION: The findings of low hepatitis B immunization coverage and the association of hepatitis B with risky behavior highlight that there is a need to intensify hepatitis B prevention programs in the southwest region of Goiás.

  9. 每搏量变异度与单肺通气患者血容量变化的相关性%Correlation between stroke volume variation and blood volume during one-lung ventilation

    Institute of Scientific and Technical Information of China (English)

    王合梅; 李超; 雍芳芳; 贾慧群

    2012-01-01

    Objective To evaluate the correlation between stroke volume variation (SVV) and blood volume during one-lung ventilation (OLV).Methods Forty ASA Ⅱ male patients,aged 50-60 yr,with body mass index 20-25 kg/m2,scheduled for elective resection of esophageal cancer,were studied.Anesthesia was induced with fentanyl 4 μg/kg,propofol 2 mg/kg,and rocuronium 0.6 mg/kg.Double-lumen tube was inserted.Correct position was verified by fiberoptic bronchoscopy.The patients were mechanically ventilated (VT 8 ml/kg,RR 15 bpm,Ⅰ ∶ E 1 ∶ 2).6% hydroxyethyl statch (HES) 130/0.4 was infused intravenously at a rate of 0.67 ml· kg-1 · min-1 starting from 30 min of OLV.SVV,cardiac output (CO),SV and cardiac index (CI) were monitored and recorded using the FloTrac/Vigileo (Edwards Lifesciences,USA) system before HES was infused and when the dose of HES reached 2,4,6,8,10 and 12 ml/kg.Spearman rank sum correlation coefficient was used to analyze the data.Results SVV was negatively correlated with the blood volume during OLV and the correlation coefficient was rSVV =-0.249.CI,CO and SV were positively correlated with the blood volume during OLV and the correlation coefficients were rCO =0.570,rSV =0.552 and rCI =0.550,respectively.Conclusion SVV is poorly correlated with the blood volume during OLV and can not reflect the blood volume accurately.%目的 探讨每搏量变异度(Svv)与单肺通气患者血容量变化的相关性.方法 择期拟行食管癌切除术患者40例,男性,年龄50~ 60岁,体重指数20 ~ 25 kg/m2,ASA分级Ⅱ级.麻醉诱导后经口明视插入F39右侧双腔支气管导管,经两肺听诊和纤维支气管镜定位后,连接麻醉机行单肺通气,设定潮气量8 ml/kg、呼吸频率15次/min、吸呼比1∶2.单肺通气30 min时静脉输注6%羟乙基淀粉130/0.4,速率为0.67 ml· kg-1·min-1,分别在输注前、输注羟乙基淀粉剂量达2、4、6、8、10、12 ml/kg时采用FloTrac/Vigileo心输出量监测系统记录SVV、CO

  10. EFFECTS OF A BASKETBALL ACTIVITY ON LUNG CAPILLARY BLOOD VOLUME AND MEMBRANE DIFFUSING CAPACITY, MEASURED BY NO/CO TRANSFER IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Rim Dridi

    2006-09-01

    Full Text Available In both children and adults, acute exercise increases lung capillary blood volume (Vc and membrane factor (DmCO. We sought to determine whether basketball training affected this adaptation to exercise in children. The purpose of this study was to determine the effects of two years sport activity on the components of pulmonary gas transfer in children. Over a 2-yr period, we retested 60 nine year old boys who were initially separated in two groups: 30 basketball players (P (9.0 ± 1.0 yrs; 35.0 ± 5.2 kg; 1.43 ± 0.05 m, and matched non players controls (C (8.9 ± 1.0 yrs; 35.0 ± 6.0 kg; 1.44 ± 0.06 m who did not perform any extracurricular activity, Vc and DmCO were measured by the NO/CO transfer method at rest and during sub-maximal exercise. Maximal aerobic power and peak power output was 12% higher in the trained group compared to matched controls (p < 0.05. Nitric oxide lung transfer (TLNO per unit lung volume and thus, DmCO per unit of lung volume (VA were higher at rest and during exercise in the group which had undergone regular basketball activity compared to matched controls (p < 0.05. Neither lung capillary blood volume nor total lung transfer for carbon monoxide (TLCO were significantly different between groups. These results suggest that active sport can alter the properties of the lung alveolo-capillary membrane by improving alveolar membrane conductance in children

  11. Color-coded perfused blood volume imaging using multidetector CT: initial results of whole-brain perfusion analysis in acute cerebral ischemia

    International Nuclear Information System (INIS)

    Computed tomography (CT) is still the primary imaging modality following acute stroke. To evaluate a prototype of software for the calculation of color-coded whole-brain perfused blood volume (PBV) images from CT angiography (CTA) and nonenhanced CT (NECT) scans, we studied 14 patients with suspected acute ischemia of the anterior cerebral circulation. PBV calculations were performed retrospectively. The detection rate of ischemic changes in the PBV images was compared with NECT. The volume of ischemic changes in PBV was correlated with the infarct volume on follow-up examination taking potential vessel recanalization into account. PBV demonstrated ischemic changes in 12/12 patients with proven infarction and was superior to NECT (8/12) in the detection of early ischemia. Moreover, PBV demonstrated the best correlation coefficient with the follow-up infarct volume (Pearson's R = 0.957; P = 0.003) for patients with proven recanalization of initially occluded cerebral arteries. In summary, PBV appears to be more accurate in the detection of early infarction compared to NECT and mainly visualizes the irreversibly damaged ischemic tissue. (orig.)

  12. Immune invasion of the central nervous system parenchyma and experimental allergic encephalomyelitis, but not leukocyte extravasation from blood, are prevented in macrophage-depleted mice

    DEFF Research Database (Denmark)

    Tran, E H; Hoekstra, K; van Rooijen, N;

    1998-01-01

    /J mice was abrogated by Cl2MDP-mnL treatment. CD4+ T cell and MHC II+ B220+ B cell extravasation from blood vessels and Th1 cytokine production were not inhibited. However, invasion of the central nervous system intraparenchymal tissues by lymphocytes, F4/80+, Mac-1+, and MOMA-1+ macrophages was almost....../microglial activation, was inhibited. This intervention reveals a role for macrophages in regulating the invasion of autoreactive T cells and secondary glial recruitment that ordinarily lead to demyelinating pathology in EAE and multiple sclerosis....

  13. Methotrexate reduces hippocampal blood vessel density and activates microglia in rats but does not elevate central cytokine release

    NARCIS (Netherlands)

    Seigers, Riejanne; Timmermans, Jessica; van der Horn, Hans J.; de Vries, Erik F. J.; Dierckx, Rudi A.; Visser, Lydia; Schagen, Sanne B.; van Dam, Frits S. A. M.; Koolhaas, Jaap M.; Buwalda, Bauke

    2010-01-01

    Methotrexate is a cytostatic drug applied in adjuvant chemotherapy and associated with cognitive impairment in part of the cancer patients. In this paper we studied in rats whether a reduction in blood supply to the brain or neuroinflammation are possible mediators of this cognitive dysfunctionality

  14. Middle cerebral artery blood velocity during rowing

    DEFF Research Database (Denmark)

    Secher, Niels Henry; Pott, F; Knudsen, L.;

    1997-01-01

    original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler......original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler...

  15. Annual exceedance probabilities and trends for peak streamflows and annual runoff volumes for the Central United States during the 2011 floods

    Science.gov (United States)

    Driscoll, Daniel G.; Southard, Rodney E.; Koenig, Todd A.; Bender, David A.; Holmes, Jr., Robert R.

    2014-01-01

    During 2011, excess precipitation resulted in widespread flooding in the Central United States with 33 fatalities and approximately $4.2 billion in damages reported in the Red River of the North, Souris, and Mississippi River Basins. At different times from late February 2011 through September 2011, various rivers in these basins had major flooding, with some locations having multiple rounds of flooding. This report provides broadscale characterizations of annual exceedance probabilities and trends for peak streamflows and annual runoff volumes for selected streamgages in the Central United States in areas affected by 2011 flooding. Annual exceedance probabilities (AEPs) were analyzed for 321 streamgages for annual peak streamflow and for 211 streamgages for annual runoff volume. Some of the most exceptional flooding was for the Souris River Basin, where of 11 streamgages considered for AEP analysis of peak streamflow, flood peaks in 2011 exceeded the next largest peak of record by at least double for 6 of the longest-term streamgages (75 to 108 years of peak-flow record). AEPs for these six streamgages were less than 1 percent. AEPs for 2011 runoff volumes were less than 1 percent for all seven Souris River streamgages considered for AEP analysis. Magnitudes of 2011 runoff volumes exceeded previous maxima by double or more for 5 of the 7 streamgages (record lengths 52 to 108 years). For the Red River of the North Basin, AEPs for 2011 runoff volumes were exceptional, with two streamgages having AEPs less than 0.2 percent, five streamgages in the range of 0.2 to 1 percent, and four streamgages in the range of 1 to 2 percent. Magnitudes of 2011 runoff volumes also were exceptional, with all 11 of the aforementioned streamgages eclipsing previous long-term (62 to 110 years) annual maxima by about one-third or more. AEPs for peak streamflows in the upper Mississippi River Basin were not exceptional, with no AEPs less than 1 percent. AEPs for annual runoff volumes

  16. Relationship of blood pressure with some cardiovascular disease risk factors in a rural population of Plateau State, North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Basil N Okeahialam

    2015-01-01

    Full Text Available Background: Hypertension is associated with certain cardiovascular disease (CVD risk factors which vary from one place to the other depending on community sophistication. We decided to obtain the situation as it affects this rural Nigerian community to be in an evidence-based position to initiate individual and group prevention strategies. Design: Cross-sectional population survey. Materials and Methods: We surveyed for CVD risk factors among subjects 15 years and above in this rural community using a questionnaire requesting personal, medical and anthropometric information. One in three of them were randomly assigned to laboratory investigations. Results: Of the 840 subjects studied, 25% were males. The population mean age was 45.5 (18.2 standard deviation (SD, with 1.8% smokers and 4.1% using alcohol. Systolic blood pressure (SBP correlated with age, body mass index (BMI, total cholesterol (TC and uric acid (UA; while diastolic blood pressure (DBP correlated with age, BMI, TC, UA and atherogenic index (AI. SBP and DBP improved with exercise but not salt intake. The local seasonings used in cooking had no impact on blood pressure. Conclusion: To reduce cardiovascular morbidity in this and probably other rural sub-Saharan African communities, BMI, TC, UA and salt intake in diet should be targeted for reduction. Physical activity should be encouraged. Interestingly, these fall into the sphere of healthy lifestyle which should be encouraged and re-inforced.

  17. Relationship of blood pressure with some cardiovascular disease risk factors in a rural population of Plateau State, North Central Nigeria

    Science.gov (United States)

    Okeahialam, Basil N.; Ogbonna, Chikaike; Joseph, Dele E.; Chuhwak, Evelyn K.; Isiguzoro, Ikechukwu O.

    2015-01-01

    Background: Hypertension is associated with certain cardiovascular disease (CVD) risk factors which vary from one place to the other depending on community sophistication. We decided to obtain the situation as it affects this rural Nigerian community to be in an evidence-based position to initiate individual and group prevention strategies. Design: Cross-sectional population survey. Materials and Methods: We surveyed for CVD risk factors among subjects 15 years and above in this rural community using a questionnaire requesting personal, medical and anthropometric information. One in three of them were randomly assigned to laboratory investigations. Results: Of the 840 subjects studied, 25% were males. The population mean age was 45.5 (18.2) standard deviation (SD), with 1.8% smokers and 4.1% using alcohol. Systolic blood pressure (SBP) correlated with age, body mass index (BMI), total cholesterol (TC) and uric acid (UA); while diastolic blood pressure (DBP) correlated with age, BMI, TC, UA and atherogenic index (AI). SBP and DBP improved with exercise but not salt intake. The local seasonings used in cooking had no impact on blood pressure. Conclusion: To reduce cardiovascular morbidity in this and probably other rural sub-Saharan African communities, BMI, TC, UA and salt intake in diet should be targeted for reduction. Physical activity should be encouraged. Interestingly, these fall into the sphere of healthy lifestyle which should be encouraged and re-inforced. PMID:26229231

  18. Gray matter blood flow and volume are reduced in association with white matter hyperintensity lesion burden: a cross-sectional MRI study.

    Science.gov (United States)

    Crane, David E; Black, Sandra E; Ganda, Anoop; Mikulis, David J; Nestor, Sean M; Donahue, Manus J; MacIntosh, Bradley J

    2015-01-01

    Cerebral White Matter Hyperintensities (WMH) are associated with vascular risk factors and age-related cognitive decline. WMH have primarily been associated with global white matter and gray matter (GM) changes and less is known about regional effects in GM. The purpose of this study was to test for an association between WMH and two GM imaging measures: cerebral blood flow (CBF) and voxel-based morphometry (VBM). Twenty-six elderly adults with mild to severe WMH participated in this cross-sectional 3 Tesla magnetic resonance imaging (MRI) study. MRI measures of GM CBF and VBM were derived from arterial spin labeling (ASL) and T1-weighted images, respectively. Fluid-attenuated inversion recovery (FLAIR) images were used to quantify the WMH lesion burden (mL). GM CBF and VBM data were used as dependent variables. WMH lesion burden, age and sex were used in a regression model. Visual rating of WMH with the Fazekas method was used to compare the WMH lesion volume regression approach. WMH volume was normally distributed for this group (mean volume of 22.7 mL, range: 2.2-70.6 mL). CBF analysis revealed negative associations between WMH volume and CBF in the left anterior putamen, subcallosal, accumbens, anterior caudate, orbital frontal, anterior insula, and frontal pole (corrected p lingual gyrus, intracalcarine, and bilateral hippocampus (corrected p < 0.05). The visual rating scale corroborated the regression findings (corrected p < 0.05). WMH lesion volume was associated with intra-group GM CBF and structural differences in this cohort of WMH adults with mild to severe lesion burden. PMID:26217223

  19. Zooplankton biomass (displacement volume, dry mass, ash-free dry mass) data collected in Eastern Central Atlantic during CIPREA project from 1978-07-25 to 1978-09-12 by France (NODC Accession 0070783)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton biomass (displacement volume, dry mass, and ashfree dry mass) data collected in Eastern Central Atlantic during CIPREA project in Jul - Sep 1978 by...

  20. Xenon/CT blood flow mapping of the liver using multidetector-row computed tomography. Compensation of respiratory misregistration by volume data

    International Nuclear Information System (INIS)

    For improvement in the accuracy of xenon/CT blood flow mapping of the liver, this study was conducted to assess whether volume-data obtained by multidetector-row helical CT could compensate for the slice misregistration caused by inconstant breath depth. Using imaging phantoms scanned on both multidetector-row and single-detector CT, suitable parameters were decided. In the phantom studies, axial scan with multidetector-row CT showed significantly greater variance of CT value than that of single detector row CT (SDCT). On multidetector-row CT, variances of the CT values maintained in low (80 kV) tube voltage, which is advantageous for detecting subtle enhancement of the liver. Images reconstructed with 10-mm thickness showed smaller variance than those of 5-mm thickness on low-pitch helical scan. Remarkable helical artifacts were seen on the high-pitch helical scan. Following the phantom studies, 7 examinees were scanned using xenon/CT with a predetermined scan protocol (80 kV, collimation 5 mm, thickness 10 mm, low-pitch helical scan). In all cases, slice compensation was necessary and was successfully performed. The number of pixels which constituted blood flow map increased after the compensation. No patients showed any significant adverse effects. In conclusion, multidetector-row helical CT has the potential for providing accurate quantification of xenon/CT blood flow mapping of liver by compensating for respiratory misregistration. (author)

  1. Lycopersicon esculentum lectin: an effective and versatile endothelial marker of normal and tumoral blood vessels in the central nervous system

    Directory of Open Access Journals (Sweden)

    S Mazzetti

    2009-06-01

    Full Text Available The binding of Lycopersicon esculentum lectin (LEA to the vascular endothelium was studied in the central nervous system of rat, mouse and guinea pig at different developmental ages, and in a gliosarcoma model. Our observations showed that LEA consistently stained the entire vascular tree in the spinal cord and in the brain of all animal species at all developmental ages investigated. In the tumor model, the staining of the vascular network was very reproducible, enabled an easy identification of vascular profiles and displayed a higher efficiency when compared to two other commonly used vascular marker (EHS laminin and PECAM-1. Moreover, our results showed that LEA staining was comparable in both vibratome and paraffin sections and could be easily combined with other markers in double labeling experiments. These observations indicate that LEA staining may represent an effective and versatile endothelial marker for the study of the vasculature of the central nervous system in different animal species and experimental conditions.

  2. Urban Services Delivery and the Poor : The Case of Three Central American Cities, Volume 2. City Reports

    OpenAIRE

    World Bank

    2002-01-01

    The present study describes, and quantifies the provision of basic urban services to the poor, in three Central American cities in El Salvador, Honduras, and, Panama. It also identifies priority areas for government intervention, using specialized household surveys to quantify current deficits, and to rank households from poor to rich, using aggregate consumption as the measure of welfare....

  3. Average Volume-Assured Pressure Support in a 16-Year-Old Girl with Congenital Central Hypoventilation Syndrome

    OpenAIRE

    Vagiakis, Emmanouil; Koutsourelakis, Ioannis; Perraki, Eleni; Roussos, Charis; Mastora, Zafeiria; Zakynthinos, Spyros; Kotanidou, Anastasia

    2010-01-01

    Congenital central hypoventilation syndrome (CCHS) is an uncommon disorder characterized by the absence of adequate autonomic control of respiration, which results in alveolar hypoventilation and decreased sensitivity to hypercarbia and hypoxemia, especially during sleep.1 Patients with CCHS need lifelong ventilatory support. The treatment options for CCHS include intermittent positive pressure ventilation administered via tracheostomy, noninvasive positive pressure ventilation, negative-pres...

  4. Financial and Fiscal Instruments for Catastrophe Risk Management : Addressing Losses from Flood Hazards in Central Europe, Volume 2. Statistical Annex

    OpenAIRE

    World Bank

    2012-01-01

    This report addresses the large flood exposures of Central Europe and proposes efficient financial and risk transfer mechanisms to mitigate fiscal losses from natural catastrophes.. The report is primarily addressed to the governments of the region which should build into their fiscal planning, the necessary contingent funding mechanisms, based on their exposures. While there exist pan-Eur...

  5. Measuring citalopram in blood and central nervous system: revealing a distribution pattern that differs from other antidepressants.

    Science.gov (United States)

    Paulzen, Michael; Lammertz, Sarah E; Gründer, Gerhard; Veselinovic, Tanja; Hiemke, Christoph; Tauber, Simone C

    2016-05-01

    The aim of this study was to measure blood and cerebrospinal fluid concentrations of citalopram and its weakly active N-demethylated metabolite desmethylcitalopram to account for the distribution between the two compartments. The findings are discussed in the context with own preceding studies on the distribution pattern of different antidepressants. Concentrations of citalopram were measured in blood serum and cerebrospinal fluid of 18 patients treated with daily doses of 10-40 mg. Daily doses were correlated with serum and cerebrospinal fluid concentrations, and serum concentrations were correlated with concentrations in cerebrospinal fluid. Serum concentrations of citalopram and desmethylcitalopram showed no significant correlation to the daily dose, r=0.164, P=0.515, and r=0.174, P=0.505, respectively, whereas citalopram concentrations in serum and cerebrospinal fluid were highly correlated (r=0.763, Pcitalopram (total=bound+unbound concentration) varied between 0.14 and 0.86 (mean 0.35, SD 0.16). By correcting the mean cerebrospinal fluid/serum ratio for 80% plasma protein binding, cerebrospinal fluid concentrations of citalopram were on average 77% higher than the calculated unbound serum concentration with a ratio of 1.77 (SD 0.81, range 0.68-4.29). Findings indicate a very good ability of citalopram to cross the blood-brain and cerebrospinal fluid barrier. High concentrations of citalopram in the cerebrospinal fluid are indicative of active transport of citalopram into or missing active transport out of the cerebrospinal fluid. The results suggest a high ability of citalopram to enter the brain with sufficiently high drug concentrations at the target sites within the brain, contributing toward clinical efficacy. PMID:26650488

  6. An intact central nervous system is not necessary for insulin-mediated increases in leg blood flow in humans

    DEFF Research Database (Denmark)

    Dela, Flemming; Stallknecht, B.; Biering-Sørensen, Fin

    in turn could be modulated by vasoconstrictive sympathetic nervous activity. Five men with complete motoric lesions of their cervical spinal cord (SCI) and nine healthy (H) men underwent a hyperinsulinemic (480 mU x min(-1) x m(-2)), euglycemic clamp combined with arterio-venous catheterization of...... one leg and microdialysis of the thigh muscle. In response to hyperinsulinemia leg blood flow increased similarly in the two groups. Leg glucose extraction and uptake were significantly lower in SCI compared with H. Two hours post clamp, leg glucose uptake rates had not yet returned to basal values...

  7. Cerebral cortical neurons with activity linked to central neurogenic spontaneous and evoked elevations in cerebral blood flow

    Science.gov (United States)

    Golanov, E. V.; Reis, D. J.

    1996-01-01

    We recorded neurons in rat cerebral cortex with activity relating to the neurogenic elevations in regional cerebral blood flow (rCBF) coupled to stereotyped bursts of EEG activity, burst-cerebrovascular wave complexes, appearing spontaneously or evoked by electrical stimulation of rostral ventrolateral medulla (RVL) or fastigial nucleus (FN). Of 333 spontaneously active neurons only 15 (5%), in layers 5-6, consistently (P neurons in deep cortical laminae whose activity correlates with neurogenic elevations of rCBF. These neurons may function to transduce afferent neuronal signals into vasodilation.

  8. Optimum coil shape for a given volume of conductor to obtain maximum central field in an air core solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, P. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    This paper is an expansion of engineering notes prepared in 1961 to address the question of how to wind circular coils so as to obtain the maximum axial field with the minimum volume of conductor. At the time this was a germain question because of the advent of superconducting wires which were in very limited supply, and the rapid push for generation of very high fields, with little concern for uniformity.

  9. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 2, Book 2. Appendices. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    The appendices include: (A) design data sheets and P and I drawing for 100-MWe commercial plant design, for all-sodium storage concept; (B) design data sheets and P and I drawing for 100-MWe commercial plant design, for air-rock bed storage concept; (C) electric power generating water-steam system P and I drawing and equipment list, 100-MWe commercial plant design; (D) design data sheets and P and I drawing for 281-MWe commercial plant design; (E) steam generator system conceptual design; (F) heat losses from solar receiver surface; (G) heat transfer and pressure drop for rock bed thermal storage; (H) a comparison of alternative ways of recovering the hydraulic head from the advanced solar receiver tower; (I) central receiver tower study; (J) a comparison of mechanical and electromagnetic sodium pumps; (K) pipe routing study of sodium downcomer; and (L) sodium-cooled advanced central receiver system simulation model. (WHK)

  10. Quantitation of regional cerebral blood flow corrected for partial volume effect using O-15 water and PET

    DEFF Research Database (Denmark)

    Iida, H; Law, I; Pakkenberg, B;

    2000-01-01

    onto the PET images in which regional CBF values and the water perfusable tissue fraction for the cortical gray matter tissue (hence the volume of gray matter) were estimated. After the PET study, the animals were killed and stereologic analysis was performed to assess the gray matter mass in the...... that included two parallel tissue compartments demonstrated better results with regards to the agreement of tissue time-activity curve and the Akaike's Information Criteria. Error sensitivity analysis suggested the model that fits three parameters of the gray matter CBF, the gray matter fraction, and...

  11. Reforming Urban Water Utilities in Western and Central Africa : Experiences with Public-Private Partnerships, Volume 2. Case Studies

    OpenAIRE

    Fall, Matar; Marin, Philippe; Locussol, Alain; Verspyck, Richard

    2009-01-01

    The Western and Central Africa has one of the longest experiences with public-private partnerships (PPPs) in the developing world, both for water supply and for combined power and water supply utilities. Cote d'Ivoire has a successful partnership dating from 1959, and over the last two decades as many as 15 countries (out of 23 in the region) have experimented with PPPs: eight for water su...

  12. In their blood : understanding heritage meanings through the socio-historical experience of Hong Kong's Central police station

    OpenAIRE

    Kilias, Antonios Constantinos

    2014-01-01

    This dissertation focuses on the personal layers of meaning attached to a heritage site, using the case study of Hong Kong’s old Central Police Station (CPS). It is a way to enhance the understanding of the site in a way that goes beyond the scope of ‘official’ records and histories, such as those found in conservation reports, government documents, etc. These documents focus heavily on the significant historical stories attached to the site and the site’s formal architectural qualities as a ...

  13. Sedentary Behavior and Light Physical Activity Are Associated with Brachial and Central Blood Pressure in Hypertensive Patients

    DEFF Research Database (Denmark)

    Gerage, A. M.; Benedetti, T. R. B.; Farah, B. Q.; Santana, F. D.; Ohara, D.; Andersen, Lars Bo; Ritti-Dias, R. M.

    2015-01-01

    pressure. Arterial stiffness parameters (augmentation index and pulse wave velocity) and cardiac autonomic modulation (sympathetic and parasympathetic modulation in the heart) were also obtained as secondary outcomes. Results Sedentary activities and light physical activities were positively and inversely......Background Physical activity is recommended as a part of a comprehensive lifestyle approach in the treatment of hypertension, but there is a lack of data about the relationship between different intensities of physical activity and cardiovascular parameters in hypertensive patients. The purpose of...... this study was to investigate the association between the time spent in physical activities of different intensities and blood pressure levels, arterial stiffness and autonomic modulation in hypertensive patients. Methods In this cross-sectional study, 87 hypertensive patients (57.5 +/- 9.9 years of...

  14. Comparative study on triangular and quadrilateral meshes by a finite-volume method with a central difference scheme

    KAUST Repository

    Yu, Guojun

    2012-10-01

    In this article, comparative studies on computational accuracies and convergence rates of triangular and quadrilateral meshes are carried out in the frame work of the finite-volume method. By theoretical analysis, we conclude that the number of triangular cells needs to be 4/3 times that of quadrilateral cells to obtain similar accuracy. The conclusion is verified by a number of numerical examples. In addition, the convergence rates of the triangular meshes are found to be slower than those of the quadrilateral meshes when the same accuracy is obtained with these two mesh types. © 2012 Taylor and Francis Group, LLC.

  15. Large volume injection of 1-octanol as sample diluent in reversed phase liquid chromatography: application in bioanalysis for assaying of indapamide in whole blood.

    Science.gov (United States)

    Udrescu, Stefan; Sora, Iulia Daniela; Albu, Florin; David, Victor; Medvedovici, Andrei

    2011-04-01

    Large volume injection of samples in strong diluents immiscible with the mobile phases used in reversed phase liquid chromatography (RPLC) has been recently introduced in practice. In the present work, the potential of the technique has been evaluated for bioanalytical applications. The process consists of the liquid-liquid extraction of indapamide from whole blood into 1-octanol, followed by the direct injection from the organic layer into the LC. Detection was made through negative electrospray ionization (ESI) and tandem mass spectrometry (MS(2)). The method was developed, validated, and successfully applied to a large number of samples in two bioequivalence studies designed for indapamide 1.5mg sustained release and 2.5mg immediate release pharmaceutical formulations. The performance of the analytical method is discussed based on data resulting from the validation procedure and the completion of the bioequivalence studies. PMID:21195573

  16. Effects of electrostimulation on the vastus medialis in the deoxygenation and the blood volume signals obtained by near-infrared spectroscopy

    Science.gov (United States)

    Verdaguer-Codina, Joan

    1996-12-01

    The electrotherapy field has been generated as a technique to improve the muscles of people affected by various pathologies. For this reason the electrotherapy is increasing its use as part of a treatment in muscle therapy. However there are not studies related to electrostimulation and near-IR spectroscopy. This work was designed to assess by near-IR spectroscopy the effects of electrostimulation in the vastus medialis, applying a tetanic contraction in this muscle with a compensated rectangular impulse at 100Hz, tolerating the subject 10mA of current. In the results obtained, we have not observed significant variations in the deoxygenation and blood volume signals, whereas as light change was observed comparing the calibration signals before and after to apply electrostimulation. It is postulated that electrostimulation only increases the diameter of the vessels, because the muscle doesn't do a metabolic work, and the heart rate frequency of the subject has not increased.

  17. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 2. Conceptual design, Sections 5 and 6

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains the detailed conceptual design and cost/performance estimates and an assessment of the commercial scale solar central receiver hybrid power system. (WHK)

  18. Characterization of alternative electric generation technologies for the SPS comparative assessment: volume 2, central-station technologies

    International Nuclear Information System (INIS)

    The SPS Concept Development and Evaluation Program includes a comparative assessment. An early first step in the assessment process is the selection and characterization of alternative technologies. This document describes the cost and performance (i.e., technical and environmental) characteristics of six central station energy alternatives: (1) conventional coal-fired powerplant; (2) conventional light water reactor (LWR); (3) combined cycle powerplant with low-Btu gasifiers; (4) liquid metal fast breeder reactor (LMFBR); (5) photovoltaic system without storage; and (6) fusion reactor

  19. Correlation between tumor size and blood volume in lung tumors: a prospective study on dual-energy gemstone spectral CT imaging.

    Science.gov (United States)

    Aoki, Masahiko; Takai, Yoshihiro; Narita, Yuichiro; Hirose, Katsumi; Sato, Mariko; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Miura, Hiroyuki; Ono, Shuichi

    2014-09-01

    The purpose of this study was to investigate the relationship between tumor size and blood volume for patients with lung tumors, using dual-energy computed tomography (DECT) and a gemstone spectral imaging (GSI) viewer. During the period from March 2011 to March 2013, 50 patients with 57 medically inoperable lung tumors underwent DECT before stereotactic body radiotherapy (SBRT) of 50-60 Gy in 5-6 fractions. DECT was taken for pretreatment evaluation. The region-of-interest for a given spatial placement of the tumors was set, and averages for CT value, water density and iodine density were compared with tumor size. The average values for iodine density in tumors of ≤ 2 cm, 2-3 cm, and >3 cm maximum diameter were 24.7, 19.6 and 16.0 (100 µg/cm(3)), respectively. The average value of the iodine density was significantly lower in larger tumors. No significant correlation was detected between tumor size and average CT value or between tumor size and average water density. Both the average water density and the average CT value were affected by the amount of air in the tumor, but the average iodine density was not affected by air in the tumor. The average water density and the average CT value were significantly correlated, but the average iodine density and the average CT value showed no significant correlation. The blood volume of tumors can be indicated by the average iodine density more accurately than it can by the average CT value. The average iodine density as assessed by DECT might be a non-invasive and quantitative assessment of the radio-resistance ascribable to the hypoxic cell population in a tumor. PMID:24829253

  20. Correlation between tumor size and blood volume in lung tumors. A prospective study on dual-energy gemstone spectral CT imaging

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the relationship between tumor size and blood volume for patients with lung tumors, using dual-energy computed tomography (DECT) and a gemstone spectral imaging (GSI) viewer. During the period from March 2011 to March 2013, 50 patients with 57 medically inoperable lung tumors underwent DECT before stereotactic body radiotherapy (SBRT) of 50-60 Gy in 5-6 fractions. DECT was taken for pretreatment evaluation. The region-of-interest for a given spatial placement of the tumors was set, and averages for CT value, water density and iodine density were compared with tumor size. The average values for iodine density in tumors of ≤ 2 cm, 2-3 cm, and > 3 cm maximum diameter were 24.7, 19.6 and 16.0 (100 μg/cm3), respectively. The average value of the iodine density was significantly lower in larger tumors. No significant correlation was detected between tumor size and average CT value or between tumor size and average water density. Both the average water density and the average CT value were affected by the amount of air in the tumor, but the average iodine density was not affected by air in the tumor. The average water density and the average CT value were significantly correlated, but the average iodine density and the average CT value showed no significant correlation. The blood volume of tumors can be indicated by the average iodine density more accurately than it can by the average CT value. The average iodine density as assessed by DECT might be a non-invasive and quantitative assessment of the radio-resistance ascribable to the hypoxic cell population in a tumor. (author)

  1. Computational approaches to the prediction of blood-brain barrier permeability: A comparative analysis of central nervous system drugs versus secretase inhibitors for Alzheimer's disease.

    Science.gov (United States)

    Rishton, Gilbert M; LaBonte, Kristen; Williams, Antony J; Kassam, Karim; Kolovanov, Eduard

    2006-05-01

    This review summarizes progress made in the development of fully computational approaches to the prediction of blood-brain barrier (BBB) permeability of small molecules, with a focus on rapid computational methods suitable for the analysis of large compound sets and virtual screening. A comparative analysis using the recently developed Advanced Chemistry Development (ACD/Labs) Inc BBB permeability algorithm for the calculation of logBB values for known Alzheimer's disease medicines, selected central nervous system drugs and new secretase inhibitors for Alzheimer's disease, is presented. The trends in logBB values and the associated physiochemical properties of these agents as they relate to the potential for BBB permeability are also discussed. PMID:16729726

  2. Pathologic and Protective Roles for Microglial Subsets and Bone Marrow- and Blood-Derived Myeloid Cells in Central Nervous System Inflammation

    DEFF Research Database (Denmark)

    Wlodarczyk, Agnieszka; Cédile, Oriane; Jensen, Kirstine Nolling;

    2015-01-01

    Inflammation is a series of processes designed for eventual clearance of pathogens and repair of damaged tissue. In the context of autoimmune recognition, inflammatory processes are usually considered to be pathological. This is also true for inflammatory responses in the central nervous system...... (CNS). However, as in other tissues, neuroinflammation can have beneficial as well as pathological outcomes. The complex role of encephalitogenic T cells in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE) may derive from heterogeneity of the myeloid cells with...... three populations of myeloid cells: CD11c(+) microglia, CD11c(-) microglia, and CD11c(+) blood-derived cells in terms of their pathological versus protective functions in the CNS of mice with EAE. Our data show that CNS-resident microglia include functionally distinct subsets that can be distinguished...

  3. Central Receiver Solar Thermal Power System, Phase 1: CDRL Item 2, Pilot plant preliminary design report. Volume 1. Executive overview

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1977-10-01

    This summary introduces the McDonnell Douglas Astronautics Company (MDAC) Central Receiver System Preliminary Design and reports the results of the Subsystem Research Experiments (SRE) recently completed. The baseline central receiver concept defined by the MDAC team consists of the following features: (A) An external receiver mounted on a tower, and located in a 360-deg array of sun-tracking heliostats which comprise the collector subsystem. (B) Feedwater from the electrical power generation subsystem is pumped through a riser to the receiver, where the feedwater is converted to superheated steam in a single pass through the tubes of the receiver panels. (C) The steam from the receiver is routed through a downcomer to the ground and introduced to a turbine directly for expansion and generation of electricity, and/or to a thermal storage subsystem, where the steam is condensed in charging heat exchangers to heat a dual-medium oil and rock thermal storage unit (TSU). (D) Extended operation after daylight hours is facilitated by discharging the TSU to generate steam for feeding the admission port of the turbine. (E) Overall control of the system is provided by a master control unit, which handles the interactions between subsystems that take place during startup, shutdown, and transitions between operating modes.

  4. SU-E-J-241: Wavelet-Based Temporal Feature Extraction From DCE-MRI to Identify Sub-Volumes of Low Blood Volume in Head-And-Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    You, D; Aryal, M; Samuels, S; Eisbruch, A; Cao, Y [University of Michigan, Ann Arbor, MI (United States)

    2015-06-15

    Purpose: A previous study showed that large sub-volumes of tumor with low blood volume (BV) (poorly perfused) in head-and-neck (HN) cancers are significantly associated with local-regional failure (LRF) after chemoradiation therapy, and could be targeted with intensified radiation doses. This study aimed to develop an automated and scalable model to extract voxel-wise contrast-enhanced temporal features of dynamic contrastenhanced (DCE) MRI in HN cancers for predicting LRF. Methods: Our model development consists of training and testing stages. The training stage includes preprocessing of individual-voxel DCE curves from tumors for intensity normalization and temporal alignment, temporal feature extraction from the curves, feature selection, and training classifiers. For feature extraction, multiresolution Haar discrete wavelet transformation is applied to each DCE curve to capture temporal contrast-enhanced features. The wavelet coefficients as feature vectors are selected. Support vector machine classifiers are trained to classify tumor voxels having either low or high BV, for which a BV threshold of 7.6% is previously established and used as ground truth. The model is tested by a new dataset. The voxel-wise DCE curves for training and testing were from 14 and 8 patients, respectively. A posterior probability map of the low BV class was created to examine the tumor sub-volume classification. Voxel-wise classification accuracy was computed to evaluate performance of the model. Results: Average classification accuracies were 87.2% for training (10-fold crossvalidation) and 82.5% for testing. The lowest and highest accuracies (patient-wise) were 68.7% and 96.4%, respectively. Posterior probability maps of the low BV class showed the sub-volumes extracted by our model similar to ones defined by the BV maps with most misclassifications occurred near the sub-volume boundaries. Conclusion: This model could be valuable to support adaptive clinical trials with further

  5. The reproducibility of left ventricular volume and mass measurements: a comparison between dual-inversion-recovery black-blood sequence and SSFP

    International Nuclear Information System (INIS)

    The aim of this study was to compare a dual-inversion-recovery black-blood (BB) magnetic resonance imaging (MRI) sequence with steady-state free precession (SSFP) for the assessment of left ventricular parameters. The improved endocardial border definition seen with SSFP was not observed at the epicardial border. Improvements in segmentation at the left ventricular epicardial border have been observed with this black-blood sequence. Left ventricular (LV) mass and LV end-diastolic volume (EDV) measurements as well as inter-observer and intra-observer variability were compared between images acquired with a dual inversion BB and SSFP sequence. The mean±1 standard deviation (SD) for LV EDV was 178.3±52.7 ml measured with SSFP and 158.8±62.2 ml with BB. This difference was not statistically significant (p=0.22). For SSFP, the mean value of LV mass was 124.0±27.0 g and 147.5±37.4 g for BB, a statistically significant difference (p<0.0001). The dual-inversion-recovery BB imaging showed improved reproducibility for LV mass measurements compared with SSFP and improved spatial resolution. For studies requiring LV mass measurements, the dual-inversion-recovery BB sequence offers improved spatial resolution and improved reproducibility to SSFP. (orig.)

  6. Cerebral blood flow volume measurements of the carotid artery and ipsilateral branches using two-dimensional phase-contrast magnetic resonance angiography

    Institute of Scientific and Technical Information of China (English)

    Gang Guo; Yonggui Yang; Weiqun Yang

    2011-01-01

    The optimal velocity encoding of phase-contrast magnetic resonance angiography (PC MRA) in measuring cerebral blood flow volume (BFV) ranges from 60 to 80 cm/s. To verify the accuracy of two-dimensional (2D) PC MRA, the present study localized the region of interest at blood vessels of the neck using PC MRA based on three-dimensional time-of-flight sequences, and the velocity encodingwas set to 80 cm/s. Results of the measurements showed that the error rate was 7.0 ± 6.0%in the estimation of BFV in the internal carotid artery, the external carotid artery and the ipsilateralcommon carotid artery. There was no significant difference, and a significant correlation in BFV between internal carotid artery + external carotid artery and ipsilateral common carotid artery. Inaddition, the BFV of the common carotid artery was correlated with that of the ipsilateral internal carotid artery. The main error was attributed to the external carotid artery and its branches. Therefore,after selecting the appropriate scanning parameters and protocols, 2D PC MRA is more accuratein the determination of BFV in the carotid arteries.

  7. MR vascular fingerprinting: A new approach to compute cerebral blood volume, mean vessel radius, and oxygenation maps in the human brain.

    Science.gov (United States)

    Christen, T; Pannetier, N A; Ni, W W; Qiu, D; Moseley, M E; Schuff, N; Zaharchuk, G

    2014-04-01

    In the present study, we describe a fingerprinting approach to analyze the time evolution of the MR signal and retrieve quantitative information about the microvascular network. We used a Gradient Echo Sampling of the Free Induction Decay and Spin Echo (GESFIDE) sequence and defined a fingerprint as the ratio of signals acquired pre- and post-injection of an iron-based contrast agent. We then simulated the same experiment with an advanced numerical tool that takes a virtual voxel containing blood vessels as input, then computes microscopic magnetic fields and water diffusion effects, and eventually derives the expected MR signal evolution. The parameter inputs of the simulations (cerebral blood volume [CBV], mean vessel radius [R], and blood oxygen saturation [SO2]) were varied to obtain a dictionary of all possible signal evolutions. The best fit between the observed fingerprint and the dictionary was then determined by using least square minimization. This approach was evaluated in 5 normal subjects and the results were compared to those obtained by using more conventional MR methods, steady-state contrast imaging for CBV and R and a global measure of oxygenation obtained from the superior sagittal sinus for SO2. The fingerprinting method enabled the creation of high-resolution parametric maps of the microvascular network showing expected contrast and fine details. Numerical values in gray matter (CBV=3.1±0.7%, R=12.6±2.4μm, SO2=59.5±4.7%) are consistent with literature reports and correlated with conventional MR approaches. SO2 values in white matter (53.0±4.0%) were slightly lower than expected. Numerous improvements can easily be made and the method should be useful to study brain pathologies. PMID:24321559

  8. Simultaneous evaluation of brain tumour metabolism, structure and blood volume using [18F]-fluoroethyltyrosine (FET) PET/MRI: feasibility, agreement and initial experience

    International Nuclear Information System (INIS)

    Both [18F]-fluoroethyltyrosine (FET) PET and blood volume (BV) MRI supplement routine T1-weighted contrast-enhanced MRI in gliomas, but whether the two modalities provide identical or complementary information is unresolved. The aims of the study were to investigate the feasibility of simultaneous structural MRI, BV MRI and FET PET of gliomas using an integrated PET/MRI scanner and to assess the spatial and quantitative agreement in tumour imaging between BV MRI and FET PET. A total of 32 glioma patients underwent a 20-min static simultaneous PET/MRI acquisition on a Siemens mMR system 20 min after injection of 200 MBq FET. The MRI protocol included standard structural MRI and dynamic susceptibility contrast (DSC) imaging for BV measurements. Maximal relative tumour FET uptake (TBRmax) and BV (rBVmax), and Dice coefficients were calculated to assess the quantitative and spatial congruence in the tumour volumes determined by FET PET, BV MRI and contrast-enhanced MRI. FET volume and TBRmax were higher in BV-positive than in BV-negative scans, and both VOLBV and rBVmax were higher in FET-positive than in FET-negative scans. TBRmax and rBVmax were positively correlated (R2 = 0.59, p < 0.001). FET and BV positivity were in agreement in only 26 of the 32 patients and in 42 of 63 lesions, and spatial congruence in the tumour volumes as assessed by the Dice coefficients was generally poor with median Dice coefficients exceeding 0.1 in less than half the patients positive on at least one modality for any pair of modalities. In 56 % of the patients susceptibility artefacts in DSC BV maps overlapped the tumour on MRI. The study demonstrated that although tumour volumes determined by BV MRI and FET PET were quantitatively correlated, their spatial congruence in a mixed population of treated glioma patients was generally poor, and the modalities did not provide the same information in this population of patients. Combined imaging of brain tumour metabolism and perfusion using

  9. Simultaneous evaluation of brain tumour metabolism, structure and blood volume using [{sup 18}F]-fluoroethyltyrosine (FET) PET/MRI: feasibility, agreement and initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, Otto M.; Hansen, Adam E.; Law, Ian [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Clinical Physiology Nuclear Medicine and PET, Copenhagen (Denmark); Larsen, Vibeke A. [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Radiology, Copenhagen (Denmark); Muhic, Aida; Poulsen, Hans S. [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Oncology, Copenhagen (Denmark); Larsson, Henrik B.W. [Copenhagen University Hospital Rigshospitalet Glostrup, Functional Imaging Unit, Department of Clinical Physiology Nuclear Medicine and PET, Glostrup (Denmark)

    2016-01-15

    Both [{sup 18}F]-fluoroethyltyrosine (FET) PET and blood volume (BV) MRI supplement routine T1-weighted contrast-enhanced MRI in gliomas, but whether the two modalities provide identical or complementary information is unresolved. The aims of the study were to investigate the feasibility of simultaneous structural MRI, BV MRI and FET PET of gliomas using an integrated PET/MRI scanner and to assess the spatial and quantitative agreement in tumour imaging between BV MRI and FET PET. A total of 32 glioma patients underwent a 20-min static simultaneous PET/MRI acquisition on a Siemens mMR system 20 min after injection of 200 MBq FET. The MRI protocol included standard structural MRI and dynamic susceptibility contrast (DSC) imaging for BV measurements. Maximal relative tumour FET uptake (TBR{sub max}) and BV (rBV{sub max}), and Dice coefficients were calculated to assess the quantitative and spatial congruence in the tumour volumes determined by FET PET, BV MRI and contrast-enhanced MRI. FET volume and TBR{sub max} were higher in BV-positive than in BV-negative scans, and both VOL{sub BV} and rBV{sub max} were higher in FET-positive than in FET-negative scans. TBR{sub max} and rBV{sub max} were positively correlated (R{sup 2} = 0.59, p < 0.001). FET and BV positivity were in agreement in only 26 of the 32 patients and in 42 of 63 lesions, and spatial congruence in the tumour volumes as assessed by the Dice coefficients was generally poor with median Dice coefficients exceeding 0.1 in less than half the patients positive on at least one modality for any pair of modalities. In 56 % of the patients susceptibility artefacts in DSC BV maps overlapped the tumour on MRI. The study demonstrated that although tumour volumes determined by BV MRI and FET PET were quantitatively correlated, their spatial congruence in a mixed population of treated glioma patients was generally poor, and the modalities did not provide the same information in this population of patients. Combined

  10. Seismic hazard methodology for the central and eastern United States. Volume 10. Tectonic interpretations by Rondout Associates, Incorporated. Final report

    International Nuclear Information System (INIS)

    The EPRI seismic hazards research program is the combined effort of seismologists, geologists, geophysicists, and statisticians to provide state-of-the-art probabilistic earthquake hazard assessment for the east and central United States. Six teams, called Tectonic Evaluation Teams (TECs), each of which combined the expertise of a seismologist, a geologist, and a geophysicist, provided seismology and tectonic input for probabilistic hazard analyses. The work described in the following report is the result of one Tectonic Evaluation Team. We followed the same procedures as did five other tectonic evaluation teams to assess the current state of stress, the earthquake potential of tectonic features, the seismologic potential of seismic source zones, and the seismicity parameters of seismic source zones

  11. Solar central receiver hybrid power system, Phase I. Volume 2. Conceptual design. Final technical report, October 1978-August 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-01

    The objectives of this study were to develop a hybrid power system design that (1) produces minimum cost electric power, (2) minimizes the capital investment and operating cost, (3) permits capacity displacement, (4) and achieves utility acceptance for market penetration. We have met the first three of these objectives and therefore believe that the fourth, utility acceptance, will become a reality. These objectives have been met by utilizing the Martin Marietta concept that combines the alternate central receiver power system design and a high-temperature salt primary heat transfer fluid and thermal storage media system with a fossil-fired nonsolar energy source. Task 1 reviewed the requirements definition document and comments and recommendations were provided to DOE/San Francisco. Task 2 consisted of a market analysis to evaluate the potential market of solar hybrid power plants. Twenty-two utilities were selected within nine regions of the country. Both written and verbal correspondence was used to assess solar hybrid power plants with respect to the utilities' future requirements and plans. The parametric analysis of Task 3 evaluated a wide range of subsystem configurations and sizes. These analyses included subsystems from the solar standalone alternate central receiver power system using high-temperature molten salt and from fossil fuel nonsolar subsystems. Task 4, selection of the preferred commerical system configuration, utilized the parametric analyses developed in Task 3 to select system and subsystem configurations for the commercial plant design. Task 5 developed a conceptual design of the selected commercial plant configuration and assessed the related cost and performance. Task 6 assessed the economics and performance of the selected configuration as well as future potential improvements or limitations of the hybrid power plants.

  12. Incorporating surface indicators of reservoir permeability into reservoir volume calculations: Application to the Colli Albani caldera and the Central Italy Geothermal Province

    Science.gov (United States)

    Giordano, Guido; De Benedetti, Arnaldo Angelo; Bonamico, Andrea; Ramazzotti, Paolo; Mattei, Massimo

    2014-01-01

    The Quaternary Roman Volcanic Province extends for over 200 km along the Tyrrhenian margin of the Italian peninsula and is composed of several caldera complexes with significant associated geothermal potential. In spite of the massive programs of explorations conducted by the then state-owned ENEL and AGIP companies between the 1970s and 1990s, and the identification of several high enthalpy fields, this resource remains so far unexploited, although it occurs right below the densely populated metropolitan area of Roma capital city. The main reason for this failure is that deep geothermal reservoirs are associated with fractured rocks, the secondary permeability of which has been difficult to predict making the identification of the most productive volumes of the reservoirs and the localisation of productive wells uncertain. As a consequence, almost half of the many exploration deep bore-holes drilled in the area reached a dry target. This work reviews available data and re-assesses the geothermal potential of caldera-related systems in Central Italy, by analysing in detail the case of the Colli Albani caldera system, the closest to Roma capital city. A GIS based approach identifies the most promising reservoir volumes for geothermal exploitation and uses an improved volume method approach for the evaluation of geothermal potential. The approach is based on a three dimensional matrix of georeferenced spatial data; the A axis accounts for the modelling of the depth of the top of the reservoirs based on geophysical and direct data; the B axis accounts for the thermal modelling of the crust (i.e. T with depth) based on measured thermal gradients. Both A and B data are necessary but not sufficient to identify rock volumes actually permeated by geothermal fluids in fractured reservoirs. We discuss the implementation of a C axis that evaluates all surface data indicating permeability in the reservoir and actual geothermal fluid circulation. We consider datasets on: i

  13. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume III, Book 1. Design description

    Energy Technology Data Exchange (ETDEWEB)

    1983-12-31

    The design of the 30 MWe central receiver solar power plant to be located at Carrisa Plains, San Luis Obispo County, California, is summarized. The plant uses a vertical flat-panel (billboard solar receiver located at the top of a tower to collect solar energy redirected by approximately 1900 heliostats located to the north of the tower. The solar energy is used to heat liquid sodium pumped from ground level from 610 to 1050/sup 0/F. The power conversion system is a non-reheat system, cost-effective at this size level, and designed for high-efficiency performance in an application requiring daily startup. Successful completion of this project will lead to power generation starting in 1986. This report discusses in detail the design of the collector system, heat transport system, thermal storage subsystem, heat transport loop, steam generation subsystem, electrical, instrumentation, and control systems, power conversion system, master control system, and balance of plant. The performance, facility cost estimate and economic analysis, and development plan are also discussed.

  14. The Fixed-Dose Combination of Olmesartan/Amlodipine Was Superior in Central Aortic Blood Pressure Reduction Compared with Perindopril/Amlodipine: A Randomized, Double-Blind Trial in Patients with Hypertension

    OpenAIRE

    Ruilope, Luis; Schaefer, Angie

    2013-01-01

    Introduction Central blood pressure (BP), an important measure of cardiovascular risk, has been shown to be effectively reduced by calcium channel blockade with amlodipine (AML) plus renin–angiotensin system blockade by the angiotensin-converting enzyme inhibitor, perindopril (PER). The aim of the SEVITENSION study was to compare the central effects of PER/AML against renin–angiotensin system blockade with the angiotensin II receptor blocker olmesartan (OLM) plus AML. Methods In this multicen...

  15. Exploiting Growing Stock Volume Maps for Large Scale Forest Resource Assessment: Cross-Comparisons of ASAR- and PALSAR-Based GSV Estimates with Forest Inventory in Central Siberia

    Directory of Open Access Journals (Sweden)

    Christian Hüttich

    2014-07-01

    Full Text Available Growing stock volume is an important biophysical parameter describing the state and dynamics of the Boreal zone. Validation of growing stock volume (GSV maps based on satellite remote sensing is challenging due to the lack of consistent ground reference data. The monitoring and assessment of the remote Russian forest resources of Siberia can only be done by integrating remote sensing techniques and interdisciplinary collaboration. In this paper, we assess the information content of GSV estimates in Central Siberian forests obtained at 25 m from ALOS-PALSAR and 1 km from ENVISAT-ASAR backscatter data. The estimates have been cross-compared with respect to forest inventory data showing 34% relative RMSE for the ASAR-based GSV retrievals and 39.4% for the PALSAR-based estimates of GSV. Fragmentation analyses using a MODIS-based land cover dataset revealed an increase of retrieval error with increasing fragmentation of the landscape. Cross-comparisons of multiple SAR-based GSV estimates helped to detect inconsistencies in the forest inventory data and can support an update of outdated forest inventory stands.

  16. Measurements of diagnostic examination performance and correlation analysis using microvascular leakage, cerebral blood volume, and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

    International Nuclear Information System (INIS)

    To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades. A prospective study of 79 patients with cerebral glial tumors underwent DSC-MR imaging. Normalized relative CBV (rCBV) and relative CBF (rCBF) from tumoral (rCBVt and rCBFt), peri-enhancing region (rCBVe and rCBFe), and the value in the tumor divided by the value in the peri-enhancing region (rCBVt/e and rCBFt/e), as well as MVL, expressed as the leakage coefficient K2 were calculated. Hemodynamic variables and tumor grades were analyzed statistically and with Pearson correlations. Receiver operating characteristic (ROC) curve analyses were also performed for each of the variables. The differences in rCBVt and the maximum MVL (MVLmax) values were statistically significant among all tumor grades. Correlation analysis using Pearson was as follows: rCBVt and tumor grade, r = 0.774; rCBFt and tumor grade, r = 0.417; MVLmax and tumor grade, r = 0.559; MVLmax and rCBVt, r = 0.440; MVLmax and rCBFt, r = 0.192; and rCBVt and rCBFt, r = 0.605. According to ROC analyses for distinguishing tumor grade, rCBVt showed the largest areas under ROC curve (AUC), except for grade III from IV. Both rCBVt and MVLmax showed good discriminative power in distinguishing all tumor grades. rCBVt correlated strongly with tumor grade; the correlation between MVLmax and tumor grade was moderate. (orig.)

  17. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 1. Conceptual design, Sections 1 through 4

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume presents in detail the market analysis, parametric analysis, and the selection process for the preferred system. (WHK)

  18. High-order central ENO finite-volume scheme for hyperbolic conservation laws on three-dimensional cubed-sphere grids

    Science.gov (United States)

    Ivan, L.; De Sterck, H.; Susanto, A.; Groth, C. P. T.

    2015-02-01

    A fourth-order accurate finite-volume scheme for hyperbolic conservation laws on three-dimensional (3D) cubed-sphere grids is described. The approach is based on a central essentially non-oscillatory (CENO) finite-volume method that was recently introduced for two-dimensional compressible flows and is extended to 3D geometries with structured hexahedral grids. Cubed-sphere grids feature hexahedral cells with nonplanar cell surfaces, which are handled with high-order accuracy using trilinear geometry representations in the proposed approach. Varying stencil sizes and slope discontinuities in grid lines occur at the boundaries and corners of the six sectors of the cubed-sphere grid where the grid topology is unstructured, and these difficulties are handled naturally with high-order accuracy by the multidimensional least-squares based 3D CENO reconstruction with overdetermined stencils. A rotation-based mechanism is introduced to automatically select appropriate smaller stencils at degenerate block boundaries, where fewer ghost cells are available and the grid topology changes, requiring stencils to be modified. Combining these building blocks results in a finite-volume discretization for conservation laws on 3D cubed-sphere grids that is uniformly high-order accurate in all three grid directions. While solution-adaptivity is natural in the multi-block setting of our code, high-order accurate adaptive refinement on cubed-sphere grids is not pursued in this paper. The 3D CENO scheme is an accurate and robust solution method for hyperbolic conservation laws on general hexahedral grids that is attractive because it is inherently multidimensional by employing a K-exact overdetermined reconstruction scheme, and it avoids the complexity of considering multiple non-central stencil configurations that characterizes traditional ENO schemes. Extensive numerical tests demonstrate fourth-order convergence for stationary and time-dependent Euler and magnetohydrodynamic flows on

  19. Production waters associated with the Ferron coalbed methane fields, central Utah: Chemical and isotopic composition and volumes

    Science.gov (United States)

    Rice, C.A.

    2003-01-01

    This study investigated the composition of water co-produced with coalbed methane (CBM) from the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale in east-central Utah to better understand coalbed methane reservoirs. The Ferron coalbed methane play currently has more than 600 wells producing an average of 240 bbl/day/well water. Water samples collected from 28 wellheads in three fields (Buzzards Bench, Drunkards Wash, and Helper State) of the northeast-southwest trending play were analyzed for chemical and stable isotopic composition.Water produced from coalbed methane wells is a Na-Cl-HCO3 type. Water from the Drunkards Wash field has the lowest total dissolved solids (TDS) (6300 mg/l) increasing in value to the southeast and northeast. In the Helper State field, about 6 miles northeast, water has the highest total dissolved solids (43,000 mg/l), and major ion abundance indicates the possible influence of evaporite dissolution or mixing with a saline brine. In the southern Buzzards Bench field, water has variable total dissolved solids that are not correlated with depth or spatial distance. Significant differences in the relative compositions are present between the three fields implying varying origins of solutes and/or different water-rock interactions along multiple flow paths.Stable isotopic values of water from the Ferron range from +0.9??? to -11.4??? ?? 18O and -32??? to -90??? ?? 2H and plot below the global meteoric water line (GMWL) on a line near, but above values of present-day meteoric water. Isotopic values of Ferron water are consistent with modification of meteoric water along a flow path by mixing with an evolved seawater brine and/or interaction with carbonate minerals. Analysis of isotopic values versus chloride (conservative element) and total dissolved solids concentrations indicates that recharge water in the Buzzards Bench area is distinct from recharge water in Drunkards Wash and is about 3 ??C warmer. These variations in

  20. A 2D-QSPR approach to predict blood-brain barrier penetration of drugs acting on the central nervous system

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    Matheus Malta de Sá

    2010-12-01

    Full Text Available Drugs acting on the central nervous system (CNS have to cross the blood-brain barrier (BBB in order to perform their pharmacological actions. Passive BBB diffusion can be partially expressed by the blood/brain partition coefficient (logBB. As the experimental evaluation of logBB is time and cost consuming, theoretical methods such as quantitative structure-property relationships (QSPR can be useful to predict logBB values. In this study, a 2D-QSPR approach was applied to a set of 28 drugs acting on the CNS, using the logBB property as biological data. The best QSPR model [n = 21, r = 0.94 (r² = 0.88, s = 0.28, and Q² = 0.82] presented three molecular descriptors: calculated n-octanol/water partition coefficient (ClogP, polar surface area (PSA, and polarizability (α. Six out of the seven compounds from the test set were well predicted, which corresponds to good external predictability (85.7%. These findings can be helpful to guide future approaches regarding those molecular descriptors which must be considered for estimating the logBB property, and also for predicting the BBB crossing ability for molecules structurally related to the investigated set.Fármacos que atuam no sistema nervoso central (SNC devem atravessar a barreira hematoencefálica (BHE para exercerem suas ações farmacológicas. A difusão passiva através da BHE pode ser parcialmente expressa pelo coeficiente de partição entre os compartimentos encefálico e sanguíneo (logBB, brain/blood partition coefficient. Considerando-se que a avaliação experimental de logBB é dispendiosa e demorada, métodos teóricos como estudos das relações entre estrutura química e propriedade (QSPR, Quantitative Structure-Property Relationships podem ser utilizados na previsão dos valores de logBB. Neste estudo, uma abordagem de QSPR-2D foi aplicada a um conjunto de 28 moléculas com ação central, usando logBB como propriedade biológica. O melhor modelo de QSPR [n = 21, r = 0,94 (r

  1. Relationship between ischemic ST depression pattern and coronary blood volume. Study using [sup 13]NH[sub 3] positron emission computed tomography under light exercise

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Takuya; Okazaki, Osamu; Michihata, Tetsuo; Hara, Toshihiko; Harumi, Kenichi (National Nakano Hospital, Tokyo (Japan)); Akutsu, Yasushi; Yamanaka, Hideyuki; Katagiri, Takashi

    1994-09-01

    To determine the relationship between ST depression pattern and coronary blood volume in exercise induced myocardial ischemia, exercise-induced ST changes on ECG and regional myocardial blood flow (RMBF) on positron emission computed tomography (PET) were examined. The subjects were 41 patients with myocardial infarction and 30 with angina pectoris, consisting of 55 men and 16 women. Five normal men served as controls. In the group of ST depression, maximum PRP and age were significantly high, and patients with multiple vessel disease accounted for 63.6%. RMBF, as shown on PET, increased by 10% or more after exercise in 71.1% in the group of non ST change and in the control group. In 60.6% of the patients having ST depression, there was a decrease in RMBF or an unfavorable increase in RMBF. Among 33 patients in the group of ST depression, 17 had a sagging type. Of these 17, 12 (70.6%) showed a decrease of RMBF or an unfavorable increase in RMBF, and 10 had triple vessel disease. Sixteen patients had a horizontal type, 8 of whom (50.0%) had a decrease or unfavorable increase in RMBF. These findings suggest that a decrease or unfavorable increase (an increased rate of 10% or less) may be involved in the occurrence of ST depression induced by exercise. In particular, patients with a sagging type ST depression should be monitored during exercise because many of these patients may have triple vessel disease and a decrease or unfavorable increase in RMBF. (N.K.).

  2. Relationship between ischemic ST depression pattern and coronary blood volume. Study using 13NH3 positron emission computed tomography under light exercise

    International Nuclear Information System (INIS)

    To determine the relationship between ST depression pattern and coronary blood volume in exercise induced myocardial ischemia, exercise-induced ST changes on ECG and regional myocardial blood flow (RMBF) on positron emission computed tomography (PET) were examined. The subjects were 41 patients with myocardial infarction and 30 with angina pectoris, consisting of 55 men and 16 women. Five normal men served as controls. In the group of ST depression, maximum PRP and age were significantly high, and patients with multiple vessel disease accounted for 63.6%. RMBF, as shown on PET, increased by 10% or more after exercise in 71.1% in the group of non ST change and in the control group. In 60.6% of the patients having ST depression, there was a decrease in RMBF or an unfavorable increase in RMBF. Among 33 patients in the group of ST depression, 17 had a sagging type. Of these 17, 12 (70.6%) showed a decrease of RMBF or an unfavorable increase in RMBF, and 10 had triple vessel disease. Sixteen patients had a horizontal type, 8 of whom (50.0%) had a decrease or unfavorable increase in RMBF. These findings suggest that a decrease or unfavorable increase (an increased rate of 10% or less) may be involved in the occurrence of ST depression induced by exercise. In particular, patients with a sagging type ST depression should be monitored during exercise because many of these patients may have triple vessel disease and a decrease or unfavorable increase in RMBF. (N.K.)

  3. Characteristics of HCV co-infection among HIV infected individuals from an area with high risk of blood-borne infections in central China.

    Directory of Open Access Journals (Sweden)

    Tiejun Zhang

    Full Text Available OBJECTIVE: Hepatitis C virus (HCV and human immunodeficiency virus (HIV co-infection has been proved to be a growing public health concern. The prevalence and genotypic pattern vary with geographic locations. Limited information is available to date with regard to HCV genotype and its clinical implications among those former commercial blood donor communities. The aims of this study were to genetically define the HCV genotype and associated clinical characteristics of HIV/HCV co-infected patients from a region with commercial blood donation history in central China. METHODS: A cross sectional study, including 164 HIV infected subjects, was conducted in Shanxi province central China. Serum samples were collected and HCV antibody testing, AST and ALT testing were performed. Seropositive samples were further subjected to RT-PCR followed by direct sequence coupled with phylogenetic analysis of Core-E1 and NS5B regions performed in comparison with known reference genotypes. FINDINGS: A total of 139 subjects were HCV antibody positive. Genotype could be determined for 88 isolates. Phylogenetic analysis revealed that the predominant circulating subtype was HCV 1b (65.9%, followed by HCV 2a (34.1%. The HCV viral load in the subjects infected with HIV1b was significantly higher than those infected with HCV 2a (P = 0.006. No significant difference for HCV RNA level was detected between ART status, CD4+ cell count level and HIV RNA level. Serum AST and ALT level were likely to increase with HCV RNA level, although no significance was observed. Those who had conducted commercial donation later than 1991 (OR 3.43, 95% CI: 1.12-10.48 and had a short duration of donation (OR 0.35, 95% CI: 0.13-0.96 were more likely to be infected with HCV 1b. CONCLUSION: These results suggest that HCV subtype 1b predominates in this population, and the impact of HIV status and ART on HCV disease progression is not significantly correlated.

  4. Effect of steroid on brain tumors and surround edemas : observation with regional cerebral blood volume (rCBV) maps of perfusion MRI

    International Nuclear Information System (INIS)

    To observe the hemodynamic change in brain tumors and peritumoral edemas after steroid treatment, and then investigate the clinical usefulness of perfusion MRI. We acquired conventional and perfusion MR images in 15 patients with various intracranial tumors (4 glioblastoma multiformes, 4 meningiomas, 3 metastatic tumors, 1 anaplastic ependymoma, 1 anaplastic astrocytoma, 1 hemangioblastoma, and 1 pilocytic astrocytoma). For perfusion MR imaging, a 1.5T unit employing the gradient-echo EPI technique was used, and further perfusion MR images were obtained 2-10 days after intravenous steroid therapy. After processing of the raw data, regional cerebral blood volume (rCBV) maps were reconstructed. The maps were visually evaluated by comparing relative perfusion in brain tumors and peritumoral edemas with that in contralateral white matter. Objective evaluations were performed by comparing the perfusion ratios of brain tumors and peritumoral edemas. Visual evaluations of rCBV maps, showed that in most brain tumors (67%, 10/15), perfusion was high before steroid treatment and showed in (80%, 12/15) decreased afterwards. Objective evaluation, showed that in all brain tumors, perfusion decreased. Visual evaluation of perfusion change in peritumoral edemas revealed change in only one case, but objective evaluation indicated that perfusion decreased significantly in all seven cases. rCBV maps acquired by perfusion MR imaging can provide hemodynamic information about brain tumors and peritumoral edemas. Such maps could prove helpful in the preoperative planning of brain tumor surgery and the monitoring of steroid effects during conservative treatment. (author)

  5. Membrane diffusion- and capillary blood volume measurements are not useful as screening tools for pulmonary arterial hypertension in systemic sclerosis: a case control study

    Directory of Open Access Journals (Sweden)

    Spreeuwenberg Marieke D

    2008-10-01

    Full Text Available Abstract Background There is no optimal screening tool for the assessment of pulmonary arterial hypertension (PAH in patients with systemic sclerosis (SSc. A decreasing transfer factor of the lung for CO (TLCO is associated with the development of PAH in SSc. TLCO can be partitioned into the diffusion of the alveolar capillary membrane (Dm and the capillary blood volume (Vc. The use of the partitioned diffusion to detect PAH in SSc is not well established yet. This study evaluates whether Dm and Vc could be candidates for further study of the use for screening for PAH in SSc. Methods Eleven SSc patients with PAH (SScPAH+, 13 SSc patients without PAH (SScPAH- and 10 healthy control subjects were included. Pulmonary function testing took place at diagnosis of PAH. TLCO was partitioned according to Roughton and Forster. As pulmonary fibrosis in SSc influences values of the (partitioned TLCO, these were adjusted for fibrosis score as assessed on HRCT. Results TLCO as percentage of predicted (% was lower in SScPAH+ than in SScPAH- (41 ± 7% vs. 63 ± 12%, p vs. 39 ± 12%, p Conclusion SScPAH+ patients have lower Dm% than SScPAH- patients. There are no correlations between Dm% and hemodynamic parameters of PAH in SScPAH+. These findings do not support further study of the role of partitioning TLCO in the diagnostic work- up for PAH in SSc.

  6. Effect of steroid on brain tumors and surround edemas : observation with regional cerebral blood volume (rCBV) maps of perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ju Youl; Sun, Joo Sung; Kim, Sun Yong; Kim, Ji Hyung; Suh, Jung Ho; Cho, Kyung Gi; Kim, Jang Sung [Ajou University, School of Medicine, Su won (Korea, Republic of)

    2000-01-01

    To observe the hemodynamic change in brain tumors and peritumoral edemas after steroid treatment, and then investigate the clinical usefulness of perfusion MRI. We acquired conventional and perfusion MR images in 15 patients with various intracranial tumors (4 glioblastoma multiformes, 4 meningiomas, 3 metastatic tumors, 1 anaplastic ependymoma, 1 anaplastic astrocytoma, 1 hemangioblastoma, and 1 pilocytic astrocytoma). For perfusion MR imaging, a 1.5T unit employing the gradient-echo EPI technique was used, and further perfusion MR images were obtained 2-10 days after intravenous steroid therapy. After processing of the raw data, regional cerebral blood volume (rCBV) maps were reconstructed. The maps were visually evaluated by comparing relative perfusion in brain tumors and peritumoral edemas with that in contralateral white matter. Objective evaluations were performed by comparing the perfusion ratios of brain tumors and peritumoral edemas. Visual evaluations of rCBV maps, showed that in most brain tumors (67%, 10/15), perfusion was high before steroid treatment and showed in (80%, 12/15) decreased afterwards. Objective evaluation, showed that in all brain tumors, perfusion decreased. Visual evaluation of perfusion change in peritumoral edemas revealed change in only one case, but objective evaluation indicated that perfusion decreased significantly in all seven cases. rCBV maps acquired by perfusion MR imaging can provide hemodynamic information about brain tumors and peritumoral edemas. Such maps could prove helpful in the preoperative planning of brain tumor surgery and the monitoring of steroid effects during conservative treatment. (author)

  7. Reliability of perfusion MR imaging in symptomatic carotid occlusive disease. Cerebral blood volume, mean transit time and time-to-peak

    International Nuclear Information System (INIS)

    Purpose: Perfusion MR imaging offers an easy quantitative evaluation of relative regional cerebral blood volume (rrCBV), relative mean transit time (rMTT) and time-to-peak (TTP). The purpose of this study was to investigate the reliability of these parameters in assessing the hemodynamic disturbance of carotid occlusive disease in comparison with normative data. Material and Methods: Dynamic contrast-enhanced T2*-weighted perfusion MR imaging was performed in 19 patients with symptomatic unilateral internal carotid artery occlusion and 20 control subjects. The three parameters were calculated from the concentration-time curve fitted by gamma-variate function. Lesion-to-contralateral ratios of each parameter were compared between patients and control subjects. Results: Mean±SD of rrCBV, rMTT and TTP ratios of patients were 1.089±0.118, 1.054±0.031 and 1.062±0.039, respectively, and those of control subjects were 1.002±0.045, 1.000±0.006, 1.001±0.006, respectively. The rMTT and TTP ratios of all patients were greater than 2SDs of control data, whereas in only 6 patients (32%), rrCBV ratios were greater than 2SDs of control data. The three parameter ratios of the patients were significantly high compared with those of control subjects, respectively (p<0.01 for rrCBV ratios, p<0.0001 for rMTT ratios, and p<0.0001 for TTP ratios). Conclusion: Our results indicate that rMTT and TTP of patients, in contrast to rrCBV, are distributed in narrow ranges minimally overlapped with control data. The rMTT and TTP could be more reliable parameters than rrCBV in assessing the hemodynamic disturbance in carotid occlusive disease

  8. Analysis of regional cerebral blood flow and distribution volume in Machado-Joseph disease by iodine-123I IMP single photon emission computed tomography

    International Nuclear Information System (INIS)

    Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia. Its clinical features vary greatly in different generations of the same family. Regional cerebral blood flow (rCBF) and distribution volume (Vd) in the pons, cerebellum, and cerebral cortex were measured in 12 patients with MJD by autoradiography (ARG) and the table look-up (TLU) method of iodine-123 IMP (123I-IMP) single photon emission computed tomography (SPECT). Representative cases were as follows: A 46-year-old woman first experienced gait ataxia at age 38. Computed tomography (CT) and magnetic resonance imaging (MRI) showed no atrophy in the pons or cerebellum, but rCBF measured by the 123I-IMP SPECT ARG method detected hypoperfusion in the pons, and cerebellar vermis and hemisphere. A 76-year-old woman first experienced gait ataxia at age 69. CT and MRI findings showed severe atrophy in the pons, and cerebellar vermis and hemisphere. Moreover, rCBF was decreased in the pons, whereas it was not decreased in the cerebellar vermis and hemisphere. In the pons of patients with MJD, rCBF was markedly decreased regardless of disease severity. Because this SPECT finding for the pons looked like a 'dot', we have called it the 'pontine dot sign'. In the MJD group, rCBF was significantly decreased in the pons (Student's t test, pd was also significantly decreased in the pons (pd for the pons and age at onset (r=0.59, pd in the cerebellar hemispheres and International Cooperative Ataxia Rating Scale (r=0.644, pd obtained by 123I-IMP SPECT for patients with MJD identified by gene analysis. Our study shows that SPECT measurement of rCBF and Vd is useful for understanding the pathophysiology of MJD. (author)

  9. EFFECTS OF LOW-INTENSITY CYCLE TRAINING WITH RESTRICTED LEG BLOOD FLOW ON THIGH MUSCLE VOLUME AND VO2MAX IN YOUNG MEN

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    Takashi Abe

    2010-09-01

    Full Text Available Concurrent improvements in aerobic capacity and muscle hypertrophy in response to a single mode of training have not been reported. We examined the effects of low-intensity cycle exercise training with and without blood flow restriction (BFR on muscle size and maximum oxygen uptake (VO2max. A group of 19 young men (mean age ± SD: 23.0 ± 1.7 years were allocated randomly into either a BFR-training group (n=9, BFR-training or a non-BFR control training group (n=10, CON-training, both of which trained 3 days/wk for 8 wk. Training intensity and duration were 40% of VO2max and 15 min for the BFR-training group and 40% of VO2max and 45 min for the CON-training group. MRI-measured thigh and quadriceps muscle cross-sectional area and muscle volume increased by 3.4-5.1% (P < 0.01 and isometric knee extension strength tended to increase by 7.7% (p < 0.10 in the BFR-training group. There was no change in muscle size (~0.6% and strength (~1.4% in the CON-training group. Significant improvements in VO2max (6.4% and exercise time until exhaustion (15.4% were observed in the BFR-training group (p < 0.05 but not in the CON-training group (-0.1 and 3. 9%, respectively. The results suggest that low-intensity, short-duration cycling exercise combined with BFR improves both muscle hypertrophy and aerobic capacity concurrently in young men.

  10. The feasibility and clinical application of flat-panel detector computer tomography in evaluating cerebral blood volume: an initial prospective study

    International Nuclear Information System (INIS)

    Objective: To investigate the feasibility and clinical value of the determination of cerebral blood volume (CBV) map by using flat-panel detector computer tomography (FDCT) angiography system. Methods: A prospective self-control clinical trial was conducted in 20 patients with cerebral ischemia who were encountered during the period from June 2010 to March 2011. All the patients were diagnosed as cerebral ischemic diseases and were scheduled to take interventional procedures. All patients underwent cerebral perfusion computer tomography (PCT) and CBV map exam which was performed by flat-panel detector computer tomography (FDCT-CBV). The CBV values obtained by the two exam types were analyzed and compared with each other by using statistic methods. Results: All PCT and FDCT-CBV exams were successfully accomplished in all the twenty patients. A significant correlation existed between the CBV images and CBV values obtained by the two exam types. The correlation coefficient was 0.68 (P<0.01). The Bland-Altman analysis showed a mean difference of -0.25±2.79 between FDCT-CBV and PCT-CBV, indicating that FDCT-CBV values were only slightly lower than those of PCT-CBV. Conclusion: CBV exam by using flat-panel detector angiography system is clinically feasible and the results of FDCT-CBV is comparable to those of PCT-CBV. As the FDCT-CBV can offer functional images of the whole brain within the catheter lab, this technique is very helpful in making the reasonable operation plan and in improving the safety of endovascular procedures in neurosurgery. (authors)

  11. Human T cell leukemia virus type I and neurologic disease: events in bone marrow, peripheral blood, and central nervous system during normal immune surveillance and neuroinflammation.

    Science.gov (United States)

    Grant, Christian; Barmak, Kate; Alefantis, Timothy; Yao, Jing; Jacobson, Steven; Wigdahl, Brian

    2002-02-01

    Human T cell lymphotropic/leukemia virus type I (HTLV-I) has been identified as the causative agent of both adult T cell leukemia (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Although the exact sequence of events that occur during the early stages of infection are not known in detail, the initial route of infection may predetermine, along with host, environmental, and viral factors, the subset of target cells and/or the primary immune response encountered by HTLV-I, and whether an HTLV-I-infected individual will remain asymptomatic, develop ATL, or progress to the neuroinflammatory disease, HAM/TSP. Although a large number of studies have indicated that CD4(+) T cells represent an important target for HTLV-I infection in the peripheral blood (PB), additional evidence has accumulated over the past several years demonstrating that HTLV-I can infect several additional cellular compartments in vivo, including CD8(+) T lymphocytes, PB monocytes, dendritic cells, B lymphocytes, and resident central nervous system (CNS) astrocytes. More importantly, extensive latent viral infection of the bone marrow, including cells likely to be hematopoietic progenitor cells, has been observed in individuals with HAM/TSP as well as some asymptomatic carriers, but to a much lesser extent in individuals with ATL. Furthermore, HTLV-I(+) CD34(+) hematopoietic progenitor cells can maintain the intact proviral genome and initiate viral gene expression during the differentiation process. Introduction of HTLV-I-infected bone marrow progenitor cells into the PB, followed by genomic activation and low level viral gene expression may lead to an increase in proviral DNA load in the PB, resulting in a progressive state of immune dysregulation including the generation of a detrimental cytotoxic Tax-specific CD8(+) T cell population, anti-HTLV-I antibodies, and neurotoxic cytokines involved in disruption of myelin-producing cells and neuronal degradation

  12. Variação do fluxo sanguíneo da artéria central da retina durante as diferentes fases do ciclo menstrual ovulatório Central retinal artery blood flow variation during menstrual cycle

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Viana

    2007-03-01

    Full Text Available OBJETIVO: avaliar a resistência vascular da artéria central da retina, por meio do fluxo Doppler, nas diferentes fases do ciclo menstrual ovulatório. MÉTODOS: estudo observacional, longitudinal e prospectivo com avaliação de 34 mulheres saudáveis, submetidas a estudo dopplerfluxométrico do fundo do olho para avaliação da resistência vascular da artéria central da retina nas posições sentada e deitada, durante quatro fases do ciclo menstrual: fase folicular inicial, fase folicular média, fase periovulatória e fase lútea média. A confirmação da ovulação no ciclo de estudo foi feita pela dosagem de progesterona sérica na fase lútea média. Foram avaliados os índices de pulsatilidade (IP e de resistência, e as velocidades máxima, mínima e média. RESULTADOS: a idade média foi de 29,7 anos. Não foram observadas diferenças entre os índices obtidos para ambos os olhos; assim, utilizamos as médias dos índices para realizar o cálculo estatístico. Quando comparadas às posições de realização do exame, detectou-se um IP maior na posição sentada; assim, as análises foram avaliadas em separado, respeitando-se a posição da paciente. O IP da artéria central da retina, avaliado com a paciente deitada, variou durante o ciclo menstrual, apresentando-se significativamente mais baixo nas fases folicular média (1,5±0,3 e periovulatória (1,5±0,3 quando comparadas às fases folicular precoce (1,7±0,4 e lútea média (1,7±0,4. Quando a avaliação foi feita com a paciente sentada não foram observadas diferenças para as diferentes fases do ciclo. CONCLUSÕES: num ciclo menstrual ovulatório ocorre diminuição da resistência vascular na artéria central da retina e posterior reversão do efeito, como demonstrado pelas variações do IP.PURPOSE: to evaluate the vascular blood flow of the central retinal arteries using dopplervelocimetry in the different phases of the ovulatory menstrual cycle. METHODS: we performed

  13. Cellular immune surveillance of central nervous system bypasses blood-brain barrier and blood-cerebrospinal-fluid barrier: revealed with the New Marburg cerebrospinal-fluid model in healthy humans.

    Science.gov (United States)

    Kleine, Tilmann O

    2015-03-01

    In healthy human brain/spinal cord, blood capillaries and venules are locked differently with junctions and basement membrane (blood-brain barrier, blood-venule barrier). In choroid plexus, epithelial tight junctions and basement membrane lock blood-cerebrospinal-fluid (CSF) barrier. Lymphocytic cell data, quantified with multicolour flow-cytometry or immuno-cytochemical methods in sample pairs of lumbar CSF, ventrictricular CSF and peripheral venous blood, are taken from references; similarly, data of thoracic duct chyle and blood sample pairs. Through three circumventricular organs (median eminence, organum vasculosum lamina terminalis, area postrema), 15-30 μl blood are pressed by blood pressure through fenestrated capillaries, matrix/basement membrane spaces and ependyma cell lacks into ventricular/suboccipital CSF to generate CD3(+) , CD4(+) , CD8(+) , CD3(+) HLA-DR(+) , CD16(+) 56(+) 3(-) NK, CD19(+) 3(-) B subsets; some B, few NK cells adhere in circumventricular organs. Into lumbar CSF, 10-15 μl thoracic chyle with five lymphocyte subsets (without CD3(+) HLA-DR(+) cells) reflux, when CSF drains out with to-and-fro movements of chyle/CSF along nerve roots. Lymphocytes in lumbar CSF represent a mixture of blood and lymph lymphocytic cells with similar HLA-DR(+) CD3(+) cell counts in ventricular and lumbar CSF, higher CD3(+) , CD4(+) , CD8(+) subsets in lumbar CSF, and few NK and B cells due to absorption in circumventricular organs. The Marburg CSF Model reflects origin and turnover of lymphatic cells in CSF realistically; the model differs from ligand-multistep processes of activated lymphocytes through blood-brain-, blood-venule-, and blood-CSF-barriers; because transfer of inactivated native lymphocytes through the barriers is not found with healthy humans, although described so in literature. PMID:25641944

  14. Blood Clots

    Science.gov (United States)

    ... Index A-Z Blood Clots Blood clots are semi-solid masses of blood that can be stationary (thrombosis) ... treated? What are blood clots? Blood clots are semi-solid masses of blood. Normally, blood flows freely through ...

  15. Presence of anti-Leishmania (Viannia braziliensis antibodies in blood donors in the West-Central region of the State of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Lais de Souza Braga

    2015-10-01

    Full Text Available ABSTRACTINTRODUCTION:Serological screening in blood banks does not include all transmittable diseases. American cutaneous leishmaniasis (ACL has a high detection rate in the municipalities of the State of Paraná.METHODS:This study analyzed the presence of anti- Leishmania braziliensisantibodies in 176 blood donors who live in these endemic areas. The variables were analyzed with the χ2 test and Stata 9.1 software. RESULTS: Twenty (11.4% samples were positive for the presence of anti- L. braziliensisantibodies. CONCLUSIONS: The high percentage of donors with anti- Leishmania spp. antibodies indicates the need to study the risk of ACL transmission through blood donors.

  16. Limit of blank and limit of detection of Plasmodium falciparum thick blood smear microscopy in a routine setting in Central Africa

    OpenAIRE

    Joanny, Fanny; Löhr, Sascha JZ; Engleitner, Thomas; Lell, Bertrand; Mordmüller, Benjamin

    2014-01-01

    Background Proper malaria diagnosis depends on the detection of asexual forms of Plasmodium spp. in the blood. Thick blood smear microscopy is the accepted gold standard of malaria diagnosis and is widely implemented. Surprisingly, diagnostic performance of this method is not well investigated and many clinicians in African routine settings base treatment decisions independent of microscopy results. This leads to overtreatment and poor management of other febrile diseases. Implementation of q...

  17. Study of the multifragmentation in central collisions of the system: 129Xe + natSn between 32 and 50 MeV/A: measurement of collective expansion energy and of freeze-out volume

    International Nuclear Information System (INIS)

    The multifragmentation of the nuclear system formed in the central collisions of the Xe+Sn reaction between 32 and 50 MeV/A has been studied with the INDRA detector. A tensorial analyse is used to select central collisions. An important part of the charge (about 85 %) is isotropically emitted. The charge partitions have the characteristics of a simultaneous multiple fragment emission. The shape of the fragment kinetic energy distributions together with the reduced velocity correlation functions indicate that the fragmentation is a simultaneous process that occurs at low density. A comparison between the experimental data and predictions of the statistical multifragmentation model of Copenhagen (SMM) shows that charge partitions agree with the hypothesis of a thermodynamical equilibrium, whereas, kinetic observables are more constraining to the model and difficult to reproduce. However, fragments correlation functions are used in order to extract the freeze-out volume and the collective radial energy. At 50 MeV/A, the freeze-out volume is estimated to be 2.7 times the normal volume. It decreases with incident energy to be nearly twice the normal volume at 32 MeV/S. The collective energy evolves from 0 to 1.3 MeV/A with the bombarding energy. This expansion is not purely thermal and originates probably from a dynamical compression developed in the early stage of the collision. (author)

  18. Analysis of regional cerebral blood flow and distribution volume in Machado-Joseph disease by iodine-{sup 123}I IMP single photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Tsunemi; Nakajima, Takashi; Fukuhara, Nobuyoshi [National Saigata Hospital, Ohagata, Niigata (Japan)

    2001-09-01

    Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia. Its clinical features vary greatly in different generations of the same family. Regional cerebral blood flow (rCBF) and distribution volume (V{sub d}) in the pons, cerebellum, and cerebral cortex were measured in 12 patients with MJD by autoradiography (ARG) and the table look-up (TLU) method of iodine-123 IMP ({sup 123}I-IMP) single photon emission computed tomography (SPECT). Representative cases were as follows: A 46-year-old woman first experienced gait ataxia at age 38. Computed tomography (CT) and magnetic resonance imaging (MRI) showed no atrophy in the pons or cerebellum, but rCBF measured by the {sup 123}I-IMP SPECT ARG method detected hypoperfusion in the pons, and cerebellar vermis and hemisphere. A 76-year-old woman first experienced gait ataxia at age 69. CT and MRI findings showed severe atrophy in the pons, and cerebellar vermis and hemisphere. Moreover, rCBF was decreased in the pons, whereas it was not decreased in the cerebellar vermis and hemisphere. In the pons of patients with MJD, rCBF was markedly decreased regardless of disease severity. Because this SPECT finding for the pons looked like a 'dot', we have called it the 'pontine dot sign'. In the MJD group, rCBF was significantly decreased in the pons (Student's t test, p<0.01) and cerebellar vermis (p<0.05). The V{sub d} was also significantly decreased in the pons (p<0.005) in comparison with that for normal subjects. Pearson's correlation analysis yielded a significant relationship between the rCBF in the pons and age at onset (r=0.578, p<0.05). There was a strong correlation between the V{sub d} for the pons and age at onset (r=0.59, p<0.05). Person's correlation analysis also showed a significant relationship between the V{sub d} in the cerebellar hemispheres and International Cooperative Ataxia Rating Scale (r=0.644, p<0.05). The pontine rCBFs in patients with early onset MJD

  19. Measurement of Anterior-Posterior Diameter of Inferior Vena Cava by Ultrasonography: A Non-Invasive Method for Estimation of Central Venous Pressure

    OpenAIRE

    R Nafisi-Moghadam; Mansourian, H.R

    2007-01-01

    Background and Objective: The assessment of blood volume is now one of the most commonly needed interventions in the first line of care and severe ill patients. Measuring central venous pressure (CVP) is an invasive method, most frequently used in clinical practice for the assessment of volume status. The di-ameter of the inferior vena cava (IVC) is a parameter to estimate central venous pressure. The purpose of this study was to determine whether measurement of the anterior-posterior diamete...

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

    Science.gov (United States)

    Miller, Wayne L

    2016-08-01

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

  1. 正常高值血压者的中心动脉压对动脉弹性功能的影响%The changes of central blood pressure and artery elasticity in individuals with high-normal blood pressure

    Institute of Scientific and Technical Information of China (English)

    王华伟; 金丹丹; 汪世军; 吴小庆; 耿伯春; 唐关敏

    2016-01-01

    Objective To evaluate the changes of central blood pressure and artery elasticity in individuals with high- normal blood pressure (HNBP). Methods A total of 138 subjects underwent health examination were divided into ideal blood pressure group (n=72) and HNBP group (n=66) according to blood pressure. The central systolic blood pressures (CSBP) was measured indirectly by Ormon- Colin non- invasive radial artery pulse wave measurement device, and carotid- femoral pulse wave velocity (cfPWV) were measured by Complior device. Regression analysis was performed to determine the relationship between CSBP and cfPWV. Results CSBP and cfPWV were significantly higher in HNBP group than in ideal blood pressure group (P<0.01). CSBP was positively related to cfPWV (r=0.53, P<0.01). Stepwise regression analysis showed that CSBP was the risk factor for cfPWV (β=0.449, P<0.01). Conclusion Central blood pressure increases with decrease of artery elasticity in individuals with normal- high blood pressure.%目的探讨正常高值血压者中心动脉压与动脉弹性的变化。方法选取在医院体检中心行健康体检者138例,根据血压分为理想血压组72例和正常高值血压组66例,采用Ormon- Colin公司的无创桡动脉脉波检测装置测量中心动脉收缩压(CSBP),应用Complior脉搏波速度测定仪测量颈股脉搏波传导速度(cfPWV)。采用回归分析方法比较CSBP与cfPWV的变化及两者的相关性。结果正常高值血压组中心动脉压和cfPWV均高于理想血压组(均P<0.05)。中心动脉压与cfPWV呈正相关(r=0.53,P<0.01)。逐步回归分析显示中心动脉压是cfPWV的主要影响因素(β=0.449,P<0.01)。结论正常高值血压者中心动脉压增高,动脉弹性下降。

  2. Study of the multifragmentation in central collisions of the system: {sup 129}Xe + {sup nat}Sn between 32 and 50 MeV/A: measurement of collective expansion energy and of freeze-out volume; Etude de la multifragmentation dans les collisions centrales pour le systeme {sup 129}Xe + {sup nat}Sn entre 32 et 50 MeV/A: mesure de l`energie collective d`expansion et du volume de freeze-out

    Energy Technology Data Exchange (ETDEWEB)

    Salou, S

    1997-12-05

    The multifragmentation of the nuclear system formed in the central collisions of the Xe+Sn reaction between 32 and 50 MeV/A has been studied with the INDRA detector. A tensorial analyse is used to select central collisions. An important part of the charge (about 85 %) is isotropically emitted. The charge partitions have the characteristics of a simultaneous multiple fragment emission. The shape of the fragment kinetic energy distributions together with the reduced velocity correlation functions indicate that the fragmentation is a simultaneous process that occurs at low density. A comparison between the experimental data and predictions of the statistical multifragmentation model of Copenhagen (SMM) shows that charge partitions agree with the hypothesis of a thermodynamical equilibrium, whereas, kinetic observables are more constraining to the model and difficult to reproduce. However, fragments correlation functions are used in order to extract the freeze-out volume and the collective radial energy. At 50 MeV/A, the freeze-out volume is estimated to be 2.7 times the normal volume. It decreases with incident energy to be nearly twice the normal volume at 32 MeV/S. The collective energy evolves from 0 to 1.3 MeV/A with the bombarding energy. This expansion is not purely thermal and originates probably from a dynamical compression developed in the early stage of the collision. (author) 88 refs.

  3. Central and peripheral contributors to skeletal muscle hyperemia: response to passive limb movement

    OpenAIRE

    McDaniel, John; Fjeldstad, Anette S.; Ives, Steve; Hayman, Melissa; Kithas, Phil; Richardson, Russell S.

    2009-01-01

    The central and peripheral contributions to exercise-induced hyperemia are not well understood. Thus, utilizing a reductionist approach, we determined the sequential peripheral and central responses to passive exercise in nine healthy men (33 ± 9 yr). Cardiac output, heart rate, stroke volume, mean arterial pressure, and femoral blood flow of the passively moved leg and stationary (control) leg were evaluated second by second during 3 min of passive knee extension with and without a thigh cuf...

  4. Gulf of Mexico sales 147 and 150: Central and western planning areas. Draft environmental impact statement. Volume 2. Sections IV.D through IX. Draft report

    International Nuclear Information System (INIS)

    Contents: environmental impacts of the proposed actions and alternatives; proposed central gulf sale 147; proposed western gulf sale 150; analysis of a large oil spill; consultation and coordination; bibliography and special references; glossary; appendices

  5. Model 1: Blood

    International Nuclear Information System (INIS)

    Because most radiopharmaceuticals are introduced into the body via the vascular system and may remain in the circulation for prolonged periods of time, it is useful to have a model of the blood as an aid in the estimation of radiation dose. It is extremely difficult to devise a precise blood model; the geometry is complex and distribution of blood may vary with position, physiological state and disease process. Estimates of blood volume distribution vary among investigators. Furthermore, the regional hematocrit varies throughout the body, thus affecting distribution of the labeled material according to whether it is attached to cellular elements or in the plasma. The size of the blood pool volumes range from the heart to the capillaries. Variable amounts of non-penetrating radiation contributions to organs depend on the volume of blood in the various sized vessels and the energy of the electrons which may penetrate into tissue from the blood vessel. The present model represents an advance in that it takes into account to some extent the distribution of significant blood pools in the body. Further refinement of the macro-geometry is possible with data which can now be obtained from modern radionuclide imaging equipment. A more difficult problem is definging the micro-geometry relative to the distribution of blood in capillaries and sinusoids, and their relationship to one another

  6. Quantitative assessment of P-glycoprotein function in the rat blood-brain barrier by distribution volume of [C-11]verapamil measured with PET

    NARCIS (Netherlands)

    Bart, J; Willemsen, ATM; Groen, HJM; van der Graaf, WTA; Wegman, TD; Vaalburg, W; de Vries, EGE; Hendrikse, NH

    2003-01-01

    The blood-brain barrier (BBB) is a functional barrier that hampers the delivery of various drugs to the brain by its physicoanatomical properties and by the presence of ATP-driven drug efflux pumps, such as P-glycoprotein (P-gp). The aims of this study were (1) to study whether the distribution volu

  7. Preferencias alimentarias de Triatoma dimidiata (Hemiptera: Reduvíidae procedente de la meseta central de Costa Rica a finales del siglo XX BLOOD SOURCES OF Triatoma dimidiata (Hemiptera: Reduvidae IN THE CENTRAL PLATEAU OF COSIA RICA AT THE END OF THE XX CENTURY

    Directory of Open Access Journals (Sweden)

    OLGER CALDERÓN-ARGUEDAS

    2001-07-01

    Full Text Available RESUMEN Se colectaron 267 ejemplares de Triatoma dimidiata procedentes de comunidades costarricenses ubicadas en tres regiones epidemiológicamente importantes por la Enfermedad de Chagas. A partir de cada insecto, se prepararon extractos de contenido intestinal los cuales fueron utilizados para determinar la presencia de sangres de diferentes vertebrados en un sistema de doble inmunodifusión (Outcherlony. También los insectos fueron sometidos a un análisis de contenido fecal para determinar la posible infección con T. cruzi. El 67% de las muestras fue positiva por sangre de humano, lo que constituyó la fuente de alimentación más importante (p 267 kissing hugs Triatoma dimidiata (Hemiptera: Reduvidae were collected in peridomestic habitats located in tthree Chagas' disease epidemiological regions of the Central plateau of Costa Rica. Gut extract were prepared from each triatomine. They were assayed in an immuno double-diffusion system (Outcherlony for detecting the presence of different kind of vertebrate bloods. Trypanosoma cruzi infection was also tested by microscopical observation of fecal smear. 67.0% of the samples were positive for human blood, that was the most important food source for the insect (p < 0.05. Dog was another important host and the blood was found in 49.8% of the samples. Rat, mouse, didelphid and chicken bloods were positive in porcentajes under 15.0%. The data can not demostrate that T. dimidata has special preferences for the avian blood. However, when the data are evaluated as exhausted and excluyent categories, chicken blood represents the second in frequency (9.0%. It could means that T. dimidata can choose the chickens as host, when humans or dogs are not available. The T. cruzi infection rate was higher in insects that were positive by opposum and rodent bloods. It suggest the role that these kind of animals can play as selvatic and domestic T. cruzi reservoirs.

  8. Age-Related Differences in Memory and Executive Functions in Healthy "APOE"[epsilon]4 Carriers: The Contribution of Individual Differences in Prefrontal Volumes and Systolic Blood Pressure

    Science.gov (United States)

    Bender, Andrew R.; Raz, Naftali

    2012-01-01

    Advanced age and vascular risk are associated with declines in the volumes of multiple brain regions, especially the prefrontal cortex, and the hippocampus. Older adults, even unencumbered by declining health, perform less well than their younger counterparts in multiple cognitive domains, such as episodic memory, executive functions, and speed of…

  9. Right ventricular volume determination by continuous [sup 81m]Kr infusion and [sup 99m]Tc blood pool imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Shinichiro; Yamashita, Saburo; Suzuki, Tetsuo; Muramatsu, Toshihiro; Ide, Masao; Suzuki, Shigeo; Dohi, Yutaka; Nishimura, Katsuyuki; Miyamae, Tatsuya (Saitama Medical School, Moroyama (Japan))

    1992-10-01

    Our newly developed radionuclide method for the calculation of right ventricular (RV) volume was examined. Using a semi-geometric count-based method, volume can be measured by the following equation: Cv=Cm/(L/d). V=(Ct/Cv)xd[sup 3]=(Ct/Cm)xLxd[sup 2]. (V=volume, Cv=voxel count, Cm=the maximum count of a container, Ct=the total count of the container, L=maximum length of the image of the container, L=maximum length of the image of the container obtained from a direction perpendicular to the direction where the count data were collected, and d=pixel size). A phantom study was performed by setting a cylindrical container in a system which circulated 5 liters of water per minute. [sup 81m]Kr solution was infused continuously into the container, and images of the container were collected for one minute. Cm and Ct were obtained, and because the container was cylindrical, the maximum width of the image of the container was measured as L. The volume of the container was calculated using the above equation. This theorem was applied to RV images obtained in the 30 degree right anterior oblique position by continuous infusion of the [sup 81m]Kr solution. Multiple gated acquisition was performed and RV end-diastolic maximum counts and total counts were obtained. The RV maximum width was measured as L on the end-diastolic cardiac pool image with [sup 99m]Tc-D-HSA collected in the 40 degree left anterior oblique position. The values obtained from these two images were substituted in the above equation and the RV end-diastolic volume (RV-EDV) was calculated. The RV ejection fraction (RV-EF) was obtained from the [sup 81m]Kr image. The RV stroke volume (SV) was calculated from multiplying the RV-EDV by the RV-EF. This value was compared to the SV with thermodilution. The correlation of these two values was r=0.90. This new method for calculating RV volume was thus considered useful. (author).

  10. Central and peripheral blood flow during exercise with a continuous-flow left ventricular assist device: constant versus increasing pump speed: a pilot study

    DEFF Research Database (Denmark)

    Brassard, Patrice; Jensen, Annette S; Nordsborg, Nikolai;

    2011-01-01

    Background- End-stage heart failure is associated with impaired cardiac output (CO) and organ blood flow. We determined whether CO and peripheral perfusion are maintained during exercise in patients with an axial-flow left ventricular assist device (LVAD) and whether an increase in LVAD pump speed...... with work rate would increase organ blood flow. Methods and Results- Invasively determined CO and leg blood flow and Doppler-determined cerebral perfusion were measured during 2 incremental cycle exercise tests on the same day in 8 patients provided with a HeartMate II LVAD. In random order, patients...... exercised both with a constant (˜9775 rpm) and with an increasing pump speed (+400 rpm per exercise stage). At 60 W, the elevation in CO was more pronounced with increased pump speed (8.7±0.6 versus 8.1±1.1 L · min(-1); mean±SD; P=0.05), but at maximal exercise increases in CO (from 7.0±0.9 to 13.6±2.5 L...

  11. Grey matter blood flow and volume are reduced in association with white matter hyperintensity lesion burden: a cross-sectional MRI study

    OpenAIRE

    David Ellis Crane; Black, Sandra E.; Mikulis, David J; Nestor, Sean M.; Donahue, Manus J; MacIntosh, Bradley J.

    2015-01-01

    Cerebral White Matter Hyperintensities (WMH) are associated with vascular risk factors and age-related cognitive decline. WMH have primarily been associated with global white matter and grey matter (GM) changes and less is known about regional effects in GM. The purpose of this study was to test for an association between WMH and two GM imaging measures: cerebral blood flow (CBF) and voxel-based morphometry. Twenty-six elderly adults with mild to severe WMH participated in this cross-secti...

  12. Systematic survey of the design, statistical analysis, and reporting of studies published in the 2008 volume of the Journal of Cerebral Blood Flow and Metabolism

    OpenAIRE

    Vesterinen, Hanna V; Egan, Kieren; Deister, Amelie; Schlattmann, Peter; Macleod, Malcolm R.; Dirnagl, Ulrich

    2010-01-01

    Translating experimental findings into clinically effective therapies is one of the major bottlenecks of modern medicine. As this has been particularly true for cerebrovascular research, attention has turned to the quality and validity of experimental cerebrovascular studies. We set out to assess the study design, statistical analyses, and reporting of cerebrovascular research. We assessed all original articles published in the Journal of Cerebral Blood Flow and Metabolism during the year 200...

  13. Quantitation of regional cerebral blood flow corrected for partial volume effect using O-15 water and PET: I. Theory, error analysis, and stereologic comparison

    DEFF Research Database (Denmark)

    Lida, H; Law, I; Pakkenberg, B;

    2000-01-01

    the white matter fraction with fixed white matter CBF as the most reliable and suitable for estimating the gray matter CBF. Reproducibility with this model was 11% for estimating the gray matter CBF. The volume of gray matter tissue can also be estimated using this model and was significantly...... formulated four mathematical models that describe the dynamic behavior of a freely diffusible tracer (H215O) in a region of interest (ROI) incorporating estimates of regional tissue flow that are independent of PVE. The current study was intended to evaluate the feasibility of these models and to establish a...... onto the PET images in which regional CBF values and the water perfusable tissue fraction for the cortical gray matter tissue (hence the volume of gray matter) were estimated. After the PET study, the animals were killed and stereologic analysis was performed to assess the gray matter mass in the...

  14. Drivers of Sustainable Rural Growth and Poverty Reduction in Central America : Guatemala Case Study, Volume 2. Background Papers and Technical Appendices

    OpenAIRE

    World Bank

    2004-01-01

    This regional study encompasses three Central American countries: Nicaragua, Guatemala and Honduras. The focus of this report is Guatemala. The study is motivated by several factors: First is the recognition that sub-national regions are becoming increasingly heterogeneous, and economically differentiated as part of ongoing processes of development and diversification, with some areas adva...

  15. Drivers of Sustainable Rural Growth and Poverty Reduction in Central America : Guatemala Case Study, Volume 1. Executive Summary and Main Text

    OpenAIRE

    World Bank

    2004-01-01

    This regional study encompasses three Central American countries: Nicaragua, Guatemala and Honduras. The focus of this report is Guatemala. The study is motivated by several factors: First is the recognition that sub-national regions are becoming increasingly heterogeneous, and economically differentiated as part of ongoing processes of development and diversification, with some areas adva...

  16. Line-focus solar central power system, Phase I. Final report, 29 September 1978 to 30 April 1980. Volume II. Text

    Energy Technology Data Exchange (ETDEWEB)

    Slemmons, A J

    1980-04-01

    The conceptual design, parametric analysis, cost and performance analysis, and a commercial assessment of a 100-MWe high-temperature line-focus central power system are presented. Parametric analyses and conceptual design of the heliostat subsystem, receiver subsystem, heat transport subsystem, energy storage subsystem, electrical power generating subsystem, and master control subsystem are included. A market analysis and development plan are given. (WHK)

  17. Clinical application of a right ventricular pressure-volume loop determined by gated blood-pool imaging and simultaneously measured right ventricular pressure

    International Nuclear Information System (INIS)

    The data obtained by ECG-gated radionuclide angiography were collected simultaneously with right ventricular pressure and thermal cardiac output (CO) obtained by a Swan-Ganz catheter in Scintipac 1200 (Shimazu Co) in order to create a right ventricular pressure-volume (RV P-V) loop. Subjects consisted of 15 patients with old myocardial infarction (MI group), seven with angina pectoris (AP group), six with congestive cardiomyopathy (CCM group) and five with neurocirculatory asthenia (NCA group). Right ventricular end-diastolic volume (RVEDV) was calculated as RVEDV = CO/(EF x HR) (CO = cardiac output; HR = heart rate). Systolic work (W sub(S)), diastolic work (W sub(D)) and net work (W sub(N)) were calculated from a RV P-V loop by Simpson's method. The measurements were performed before and 5 min after sublingual administration of nitroglycerin (NG) (0.3 mg). The results were as follows: 1. RV P-V loops shifted towards the left lower part of the P-V plane after sublingual administration of nitroglycerin, indicating the reduction of pressure and volume of the right ventricle. 2. Right ventricular ejection fraction (RVEF) in the MI, AP and CCM groups showed smaller values than that of the NCA group. 3. Right ventricular end-diastolic volume index (RVEDVI) showed a converse relation with RVEF. 4. Cardiac index in all groups decreased after NG and a statistical significance was seen in the MI, AP and NCA groups (p<0.05). 5. RV W sub(S), RV W sub(D) and RV W sub(N) showed no difference among each groups in the control state, and significantly decreased after NG. We conclude that the present method using RV P-V loop might be useful as a noninvasive bedside monitoring and permits the evaluation of RV function in a clinical setting

  18. Clinical application of a right ventricular pressure-volume loop determined by gated blood-pool imaging and simultaneously measured right ventricular pressure

    Energy Technology Data Exchange (ETDEWEB)

    Yasue, Takao; Watanabe, Sachiro; Sugishita, Nobuyoshi; Tanaka, Tsutomu; Yokoyama, Hideo (Prefectural Gifu Hospital (Japan))

    1983-09-01

    The data obtained by ECG-gated radionuclide angiography were collected simultaneously with right ventricular pressure and thermal cardiac output (CO) obtained by a Swan-Ganz catheter in Scintipac 1200 (Shimazu Co) in order to create a right ventricular pressure-volume (RV P-V) loop. Subjects consisted of 15 patients with old myocardial infarction (MI group), seven with angina pectoris (AP group), six with congestive cardiomyopathy (CCM group) and five with neurocirculatory asthenia (NCA group). Right ventricular end-diastolic volume (RVEDV) was calculated as RVEDV = CO/(EF x HR) (CO = cardiac output; HR = heart rate). Systolic work (W sub(S)), diastolic work (W sub(D)) and net work (W sub(N)) were calculated from a RV P-V loop by Simpson's method. The measurements were performed before and 5 min after sublingual administration of nitroglycerin (NG) (0.3 mg). The results were as follows: 1. RV P-V loops shifted towards the left lower part of the P-V plane after sublingual administration of nitroglycerin, indicating the reduction of pressure and volume of the right ventricle. 2. Right ventricular ejection fraction (RVEF) in the MI, AP and CCM groups showed smaller values than that of the NCA group. 3. Right ventricular end-diastolic volume index (RVEDVI) showed a converse relation with RVEF. 4. Cardiac index in all groups decreased after NG and a statistical significance was seen in the MI, AP and NCA groups (p<0.05). 5. RV W sub(S), RV W sub(D) and RV W sub(N) showed no difference among each groups in the control state, and significantly decreased after NG. We conclude that the present method using RV P-V loop might be useful as a noninvasive bedside monitoring and permits the evaluation of RV function in a clinical setting.

  19. Acanthamoeba produces disseminated infection in locusts and traverses the locust blood-brain barrier to invade the central nervous system

    OpenAIRE

    Kirk Ruth; Goldsworthy Graham; Mortazavi Parisa N; Khan Naveed A.

    2010-01-01

    Abstract Background Many aspects of Acanthamoeba granulomatous encephalitis remain poorly understood, including host susceptibility and chronic colonization which represent important features of the spectrum of host-pathogen interactions. Previous studies have suggested locusts as a tractable model in which to study Acanthamoeba pathogenesis. Here we determined the mode of parasite invasion of the central nervous system (CNS). Results Using Acanthamoeba isolates belonging to the T1 and T4 gen...

  20. Rac1-mediated signaling plays a central role in secretion-dependent platelet aggregation in human blood stimulated by atherosclerotic plaque

    OpenAIRE

    Khandoga Anna L; Pandey Dharmendra; Dwivedi Suman; Brandl Richard; Siess Wolfgang

    2010-01-01

    Abstract Background Platelet activation requires rapid remodeling of the actin cytoskeleton which is regulated by small GTP-binding proteins. By using the Rac1-specific inhibitor NSC23766, we have recently found that Rac1 is a central component of a signaling pathway that regulates dephosphorylation and activation of the actin-dynamising protein cofilin, dense and α-granule secretion, and subsequent aggregation of thrombin-stimulated washed platelets. Objectives To study whether NSC23766 inhi...

  1. Blood pressure

    Science.gov (United States)

    ... the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart contracts, which ... as it relaxes, which is called diastole. Normal blood pressure is considered to be a systolic blood pressure ...

  2. Blood transfusions

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000431.htm Blood transfusions To use the sharing features on this ... several sources of blood which are described below. Blood From the Public (Volunteer Blood Donation) The most ...

  3. Blood Basics

    Science.gov (United States)

    ... Patient Group Links Advocacy Toolkit Home For Patients Blood Basics Blood is a specialized body fluid. It ... about 9 pints. Jump To: The Components of Blood and Their Importance Many people have undergone blood ...

  4. Blood Thinners

    Science.gov (United States)

    If you have some kinds of heart or blood vessel disease, or if you have poor blood flow to your brain, your doctor may recommend that you take a blood thinner. Blood thinners reduce the risk of heart ...

  5. Blood culture

    Science.gov (United States)

    Culture - blood ... A blood sample is needed . The site where blood will be drawn is first cleaned with an antiseptic such ... organism from the skin getting into (contaminating) the blood sample and causing a false-positive result (see ...

  6. Gray matter blood flow and volume are reduced in association with white matter hyperintensity lesion burden: a cross-sectional MRI study

    OpenAIRE

    Crane, David E.; Black, Sandra E.; Ganda, Anoop; Mikulis, David J; Nestor, Sean M.; Donahue, Manus J; MacIntosh, Bradley J.

    2015-01-01

    Cerebral White Matter Hyperintensities (WMH) are associated with vascular risk factors and age-related cognitive decline. WMH have primarily been associated with global white matter and gray matter (GM) changes and less is known about regional effects in GM. The purpose of this study was to test for an association between WMH and two GM imaging measures: cerebral blood flow (CBF) and voxel-based morphometry (VBM). Twenty-six elderly adults with mild to severe WMH participated in this cross-se...

  7. Rapid quantification of conjugated and unconjugated bile acids and C27 precursors in dried blood spots and small volumes of serum[S

    OpenAIRE

    Janzen, N; Sander, S.; Terhardt, M.; Das, A.M; Sass, J.O.; Kraetzner, R.; Rosewich, H.; Peter, M.; Sander, J.

    2010-01-01

    The aim of the study was to develop a method for fast and reliable diagnosis of peroxisomal diseases and to facilitate differential diagnosis of cholestatic hepatopathy. For the quantification of bile acids and their conjugates as well as C27 precursors di- and trihydroxycholestanoic acid (DHCA, THCA), in small pediatric blood samples we combined HPLC separation on a reverse-phase C18 column with ESI-MS/MS analysis in the negative ion mode. Analysis was done with good precision (CV 3,7%–11.1%...

  8. The course of lung inflation alters the central pattern of tracheobronchial cough in cat-The evidence for volume feedback during cough.

    Science.gov (United States)

    Poliacek, Ivan; Simera, Michal; Veternik, Marcel; Kotmanova, Zuzana; Pitts, Teresa; Hanacek, Jan; Plevkova, Jana; Machac, Peter; Visnovcova, Nadezda; Misek, Jakub; Jakus, Jan

    2016-07-15

    The effect of volume-related feedback and output airflow resistance on the cough motor pattern was studied in 17 pentobarbital anesthetized spontaneously-breathing cats. Lung inflation during tracheobronchial cough was ventilator controlled and triggered by the diaphragm electromyographic (EMG) signal. Altered lung inflations during cough resulted in modified cough motor drive and temporal features of coughing. When tidal volume was delivered (via the ventilator) there was a significant increase in the inspiratory and expiratory cough drive (esophageal pressures and EMG amplitudes), inspiratory phase duration (CTI), total cough cycle duration, and the duration of all cough related EMGs (Tactive). When the cough volume was delivered (via the ventilator) during the first half of inspiratory period (at CTI/2-early over inflation), there was a significant reduction in the inspiratory and expiratory EMG amplitude, peak inspiratory esophageal pressure, CTI, and the overlap between inspiratory and expiratory EMG activity. Additionally, there was significant increase in the interval between the maximum inspiratory and expiratory EMG activity and the active portion of the expiratory phase (CTE1). Control inflations coughs and control coughs with additional expiratory resistance had increased maximum expiratory esophageal pressure and prolonged CTE1, the duration of cough abdominal activity, and Tactive. There was no significant difference in control coughing and/or control coughing when sham ventilation was employed. In conclusion, modified lung inflations during coughing and/or additional expiratory airflow resistance altered the spatio-temporal features of cough motor pattern via the volume related feedback mechanism similar to that in breathing. PMID:27125979

  9. Reforming Urban Water Utilities in Western and Central Africa : Experiences with Public-Private Partnerships, Volume 1. Impact and Lessons Learned

    OpenAIRE

    Fall, Matar; Marin, Philippe; Locussol, Alain; Verspyck, Richard

    2009-01-01

    The Western and Central Africa has one of the longest experiences with public-private partnerships (PPPs) in the developing world, both for water supply and for combined power and water supply utilities. Cote d'Ivoire has a successful partnership dating from 1959, and over the last two decades as many as 15 countries (out of 23 in the region) have experimented with PPPs: eight for water su...

  10. Initial distribution volume of glucose can be approximated using a conventional glucose analyzer in the intensive care unit

    OpenAIRE

    Ishihara, Hironori; Nakamura, Hitomi; Okawa, Hirobumi; Takase, Hajime; Tsubo, Toshihito; Hirota, Kazuyoshi

    2005-01-01

    Introduction We previously reported that initial distribution volume of glucose (IDVG) reflects central extracellular fluid volume, and that IDVG may represent an indirect measure of cardiac preload that is independent of the plasma glucose values present before glucose injection or infusion of insulin and/or vasoactive drugs. The original IDVG measurement requires an accurate glucose analyzer and repeated arterial blood sampling over a period of 7 min after glucose injection. The purpose of ...

  11. Central blood pressure and pulse wave velocity: relationship to target organ damage and cardiovascular morbidity-mortality in diabetic patients or metabolic syndrome. An observational prospective study. LOD-DIABETES study protocol

    Directory of Open Access Journals (Sweden)

    Castaño-Sánchez Carmen

    2010-03-01

    Full Text Available Abstract Background Diabetic patients show an increased prevalence of non-dipping arterial pressure pattern, target organ damage and elevated arterial stiffness. These alterations are associated with increased cardiovascular risk. The objectives of this study are the following: to evaluate the prognostic value of central arterial pressure and pulse wave velocity in relation to the incidence and outcome of target organ damage and the appearance of cardiovascular episodes (cardiovascular mortality, myocardial infarction, chest pain and stroke in patients with type 2 diabetes mellitus or metabolic syndrome. Methods/Design Design: This is an observational prospective study with 5 years duration, of which the first year corresponds to patient inclusion and initial evaluation, and the remaining four years to follow-up. Setting: The study will be carried out in the urban primary care setting. Study population: Consecutive sampling will be used to include patients diagnosed with type 2 diabetes between 20-80 years of age. A total of 110 patients meeting all the inclusion criteria and none of the exclusion criteria will be included. Measurements: Patient age and sex, family and personal history of cardiovascular disease, and cardiovascular risk factors. Height, weight, heart rate and abdominal circumference. Laboratory tests: hemoglobin, lipid profile, creatinine, microalbuminuria, glomerular filtration rate, blood glucose, glycosylated hemoglobin, blood insulin, fibrinogen and high sensitivity C-reactive protein. Clinical and 24-hour ambulatory (home blood pressure monitoring and self-measured blood pressure. Common carotid artery ultrasound for the determination of mean carotid intima-media thickness. Electrocardiogram for assessing left ventricular hypertrophy. Ankle-brachial index. Retinal vascular study based on funduscopy with non-mydriatic retinography and evaluation of pulse wave morphology and pulse wave velocity using the SphygmoCor system. The

  12. Central receiver solar thermal power system. Phase 1. CDRL item 2; Pilot Plant preliminary design report. Volume II. System decription and system analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1977-10-01

    An active system analysis and integration effort has been maintained. These activities have included the transformation of initial program requirements into a preliminary system design, the evolution of subsystem requirements which lay the foundation for subsystem design and test activity, and the overseeing of the final preliminary design effort to ensure that the subsystems are operationally compatible and capable of producing electricity at the lowest possible cost per unit of energy. Volume II of the Preliminary Design Report presents the results of the overall system effort that went on during this contract. The effort is assumed to include not only the total system definition and design but also all subsystem interactions.

  13. Gulf of Mexico Sales 157 and 161: Central and western planning areas final environmental impact statement, Volume I: Sections I through IV.C

    International Nuclear Information System (INIS)

    This Final Environmental Impact Statement (EIS) covers the proposed 1996 Gulf of Mexico OCS oil and gas lease sales [Central Gulf of Mexico Sale 157 (March 1996) and Western Gulf of Mexico Sale 161 (August 1996)]. This document includes the purpose and background of the proposed actions, the alternatives, the descriptions of the affected environment, and the potential environmental impacts of the proposed actions and alternatives. Proposed mitigating measures and their potential effects are analyzed, in addition to potential cumulative impacts resulting from proposed activities

  14. Gulf of Mexico Sales 147 and 150: Central and Western planning areas. Final environmental impact statement, Volume 1: Sections 1 through 4.C

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    This Final Environmental Impact Statement (EIS) covers the proposed 1994 Gulf of Mexico OCS oil and gas lease sales [Central Gulf of Mexico Sale 147 (March 1994) and Western Gulf of Mexico Sale 150 (August 1994)]. This document includes the purpose and background of the proposed actions, the alternatives, the descriptions of the affected environment, and the potential environmental impacts of the proposed actions and alternatives. Proposed mitigating measures and their effects are analyzed, in addition to potential cumulative impacts resulting from proposed activities.

  15. Gulf of Mexico sales 147 and 150: Central and western planning areas. Draft environmental impact statement. Volume 1. Sections I through IV.C. Draft report

    International Nuclear Information System (INIS)

    The Draft Environmental Impact Statement (EIS) covers the proposed 1994 Gulf of Mexico OCS oil and gas lease sales (Central Gulf of Mexico Sale 147 (March 1994) and Western Gulf of Mexico Sale 150 (August 1994)). The document includes the purpose and background of the proposed actions, the alternatives, the description of the affected environment, and the potential environmental impacts of the proposed actions and alternatives. Proposed mitigating measures and their effects are analyzed, in addition to potential cumulative impacts resulting from proposed activities

  16. Solar Pilot Plant, Phase I. Preliminary design report. Volume II, Book 2. Central receiver optical model users manual. CDRL item 2. [HELIAKI code

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-05-01

    HELIAKI is a FORTRAN computer program which simulates the optical/thermal performance of a central receiver solar thermal power plant for the dynamic conversion of solar-generated heat to electricity. The solar power plant which this program simulates consists of a field of individual sun tracking mirror units, or heliostats, redirecting sunlight into a cavity, called the receiver, mounted atop a tower. The program calculates the power retained by that cavity receiver at any point in time or the energy into the receiver over a year's time using a Monte Carlo ray trace technique to solve the multiple integral equations. An artist's concept of this plant is shown.

  17. Integrative Analysis of mRNA, microRNA, and Protein Correlates of Relative Cerebral Blood Volume Values in GBM Reveals the Role for Modulators of Angiogenesis and Tumor Proliferation

    Science.gov (United States)

    Rao, Arvind; Manyam, Ganiraju; Rao, Ganesh; Jain, Rajan

    2016-01-01

    Dynamic susceptibility contrast-enhanced magnetic resonance imaging is routinely used to provide hemodynamic assessment of brain tumors as a diagnostic as well as a prognostic tool. Recently, it was shown that the relative cerebral blood volume (rCBV), obtained from the contrast-enhancing as well as -nonenhancing portion of glioblastoma (GBM), is strongly associated with overall survival. In this study, we aim to characterize the genomic correlates (microRNA, messenger RNA, and protein) of this vascular parameter. This study aims to provide a comprehensive radiogenomic and radioproteomic characterization of the hemodynamic phenotype of GBM using publicly available imaging and genomic data from the Cancer Genome Atlas GBM cohort. Based on this analysis, we identified pathways associated with angiogenesis and tumor proliferation underlying this hemodynamic parameter in GBM. PMID:27053917

  18. Electroencephalography reveals lower regional blood perfusion and atrophy of the temporoparietal network associated with memory deficits and hippocampal volume reduction in mild cognitive impairment due to Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Moretti DV

    2015-02-01

    Full Text Available Davide Vito MorettiNational Institute for the research and cure of Alzheimer’s disease, S. John of God, Fatebenefratelli, Brescia, Italy Background: An increased electroencephalographic (EEG upper/lower alpha power ratio has been associated with less regional blood perfusion, atrophy of the temporoparietal region of the brain, and reduction of hippocampal volume in subjects affected by mild cognitive impairment due to Alzheimer’s disease as compared with subjects who do not develop the disease. Moreover, EEG theta frequency activity is quite different in these groups. This study investigated the correlation between biomarkers and memory performance.Methods: EEG α3/α2 power ratio and cortical thickness were computed in 74 adult subjects with prodromal Alzheimer’s disease. Twenty of these subjects also underwent assessment of blood perfusion by single-photon emission computed tomography (SPECT. Pearson’s r was used to assess the correlation between cortical thinning, brain perfusion, and memory impairment.Results: In the higher α3/α2 frequency power ratio group, greater cortical atrophy and lower regional perfusion in the temporoparietal cortex was correlated with an increase in EEG theta frequency. Memory impairment was more pronounced in the magnetic resonance imaging group and SPECT groups.Conclusion: A high EEG upper/low alpha power ratio was associated with cortical thinning and less perfusion in the temporoparietal area. Moreover, atrophy and less regional perfusion were significantly correlated with memory impairment in subjects with prodromal Alzheimer’s disease. The EEG upper/lower alpha frequency power ratio could be useful for identifying individuals at risk for progression to Alzheimer’s dementia and may be of value in the clinical context.Keywords: electroencephalography, perfusion, atrophy, temporoparietal network, memory deficits, hippocampal volume, mild cognitive impairment, Alzheimer’s disease

  19. Long-term storage of authentic postmortem forensic blood samples at -20°C: measured concentrations of benzodiazepines, central stimulants, opioids and certain medicinal drugs before and after storage for 16-18 years.

    Science.gov (United States)

    Karinen, Ritva; Andresen, Wenche; Smith-Kielland, Anne; Mørland, Jørg

    2014-01-01

    The long-term stability of benzodiazepines, opioids, central stimulants and medicinal drugs in authentic postmortem blood samples was studied. All together, 73 samples were reanalyzed after storage at -20°C for 16-18 years. At reanalysis samples containing diazepam, nordiazepam and flunitrazepam demonstrated only small changes during long-term storage when mean and median drug concentrations were compared, while clonazepam concentrations tended to decrease. Samples containing amphetamine, morphine, codeine and 'acidic' medicinal drugs as paracetamol and meprobamate also showed small changes over 16-18 years in mean and median drug concentrations at a group level. For many drugs, however, single samples could demonstrate marked concentration changes, both increases and decreases during storage. For 'alkaline' medicinal drugs, concentration losses were observed in most cases. PMID:25015743

  20. Changes in central and peripheral blood pressures before and after treadmill exercise among aircrew and non-aircrew%空勤人员与非空勤人员运动前后中心与外周血压的变化规律

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Objective This study was designed to compare the central and peripheral blood pressure changes before and after treadmill stress test among the aircrew and the non-aircrew, to examine the regularity of the changes in blood pressures of the aircrew and the effect of long term physical exercise on their vascular health, and to explore the blood pressure management and the value of central arterial blood pressure in the physical fitness assessment among the aircrew. Methods After collecting the medical history and recording the general information, the subjects were informed and asked to sign the informed consent form. The subjects were allowed to rest on examination table for 10 minutes before the blood pressure measurement. The peripheral blood pressure at the left brachial artery was measured with mercury sphygmomanometer, while the central arterial blood pressure was measured with a noninvasive aortic pulse wave analyzer. The subjects were asked to undergo the treadmill stress test until the target heart rates were reached. The subjects were allowed to lie on the examination table for six minutes before having their ECG and central arterial blood pressure examined. Results Among the aircrew, there were significant changes in peripheral arterial systolic blood pressure(SBP) and diastolic blood pressure (DBP) before and after the treadmill stress test (P0.05). Among the non-aircrew, there were no significant changes in peripheral arterial systolic blood pressure and diastolic blood pressure before and after the treadmill stress test (P>0.05). However, there was significant change in the central systolic blood pressure (CSBP) before and after the treadmill stress test (P0.05). Conclusions ①For the aircrew, the peripheral blood pressure changed significantly after the treadmill stress test, while the central arterial blood pressure was relatively stable. ②The effect of heart rate was significant on the peripheral blood pressure of the aircrew, but not significant

  1. Validation of Indian diabetic risk score in diagnosing type 2 diabetes mellitus against high fasting blood sugar levels among adult population of central India.

    Science.gov (United States)

    Bhadoria, Ajeet Singh; Kasar, Pradeep Kumar; Toppo, Neelam Anupama

    2015-01-01

    Globally the increasing prevalence of diabetes mellitus (DM) is major public health concern. The Indian Diabetes Risk Score (IDRS) was developed by Madras Diabetes Research Foundation (MDRF) as a simple tool to help detect undiagnosed type 2 DM (T2DM) in the community. We conducted a study among 911 adults of Jabalpur District to validate the IDRS score against increased fasting blood sugar levels in diagnosing T2DM. T2DM was confirmed either by history of previously known disease or fasting plasma glucose ≥126 mg/dl on two occasions. Sensitivity, specificity, positive predictive value, negative predictive value, Youden index (sensitivity + specificity -1), likelihood ratio for positive test, and likelihood ratio for negative test were calculated for IDRS cut-offs of ≥20, ≥40, ≥60, and ≥80 against the presence of T2DM (either known diabetic or fasting plasma glucose >126 mg/dl on two occasions). The overall prevalence of T2DM was 9.99% (95% confidence interval, 8.04-11.94%). In the Receiver operating characteristic analysis, IDRS had an area under the curve of 0.736 (P indicate that IDRS has excellent predictive value for detecting undiagnosed diabetes in the community and IDRS is also a much stronger risk indicator than examining individual risk factors like age, family history, obesity, or physical activity. PMID:25355391

  2. Simultaneous in vivo synchrotron radiation computed tomography of regional ventilation and blood volume in rabbit lung using combined K-edge and temporal subtraction

    Energy Technology Data Exchange (ETDEWEB)

    Suhonen, H [Department of Physical Sciences, University of Helsinki (Finland); Porra, L [Department of Physical Sciences, University of Helsinki (Finland); Bayat, S [Universite de Picardie Jules Verne, Faculte de Medecine, PERITOX (EA-INI RIS) and Cardiologie et Pneumo-Allerglogie Pediatriques, CHU Amiens (France); Sovijaervi, A R A [Department of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, Helsinki (Finland); Suortti, P [Department of Physical Sciences, University of Helsinki (Finland)

    2008-02-07

    In K-edge subtraction (KES) imaging with synchrotron radiation computed tomography (SRCT), two images are taken simultaneously using energies above and below the K-absorption edge of a contrast agent. A logarithmic difference image reveals the contrast agent concentration with good accuracy. Similarly, in temporal subtraction imaging (TSI) the reference image is taken before the introduction of the contrast agent. Quantitative comparisons of in vivo images of rabbit lung indicated that similar results for concentrations of iodine in blood vessels and xenon in airways are obtained by KES and TSI, but the level of noise and artifacts was higher in the latter. A linear fit showed that in the lung parenchyma {rho}{sub TSI} = (0.97 {+-} 0.03){rho}{sub KES} + (0.00 {+-} 0.05) for xenon and {rho}{sub TSI} = (1.21 {+-} 0.15){rho}{sub KES} + (0.0 {+-} 0.1) for iodine. For xenon the calculation of time constant of ventilation gave compatible values for both of the methods. The two methods are combined for the simultaneous determination of the xenon concentration (by KES) and the iodine concentration (by TSI) in lung imaging, which will allow simultaneous in vivo determination of ventilation and perfusion.

  3. Contributo da curva de débito-volume na detecção da obstrução da via aérea central

    OpenAIRE

    Raposo, Liliana Bárbara Perestrelo de Andrade e

    2010-01-01

    RESUMO: Introdução: A obstrução da via aérea central (OVAC) refere-se a um processo patológico que conduz a limitação do fluxo de ar ao nível do espaço glótico e subglótico, traqueia e brônquios principais. O seu correcto diagnóstico e tratamento constituem um território de interesse e preocupação para os profissionais de saúde, e requerem um profundo conhecimento da sua etiologia, fisiologia, diagnóstico e opções terapêuticas dado o potencial em originar significativa morbilidade e mortalida...

  4. Antihypertensive Treatment and Change in Blood Pressure Are Associated With the Progression of White Matter Lesion Volumes: The Three-City (3C)-Dijon Magnetic Resonance Imaging Study

    International Nuclear Information System (INIS)

    Background-Blood pressure (BP) is recognized as a major risk factor for white matter lesions (WMLs), but longitudinal data are scarce, and there is insufficient evidence for the benefit of antihypertensive therapy on WML progression. We studied the relationship between BP change and WML volume progression over time in a sample of 1319 elderly individuals who had 2 cerebral magnetic resonance imaging examinations 4 years apart. We also examined the impact of antihypertensive treatment on WML progression. Methods and Results-Subjects were participants from the Three-City (3C)-Dijon Magnetic Resonance Imaging Study, a prospective population-based cohort of elderly ≥65 years of age. WML volumes and their progression were estimated with the use of a fully automatic procedure. We performed ANCOVA models first to assess the association between BP change and WML progression and second to estimate the relation between antihypertensive treatment and WML load progression. Baseline and change in BP were significant predictors of higher WML progression over time after controlling for potential confounders. Among subjects with high SBP (160 mm Hg) at baseline not treated by antihypertensive medication, antihypertensive treatment started within 2 years was related to a smaller increase in WML volume at a 4-year follow-up (0.24 cm3; SE0.44 cm3) than no hypertensive treatment (1.60 cm3; SE0.26 cm3; P0.0008) on multivariable modeling. Conclusions-Our findings reinforce the hypothesis that hypertension is a strong predictor of WML and that adequate treatment may reduce the course of WML progression. Because WMLs are linked to both dementia and stroke risks, these results could have implications for future preventive trials. (authors)

  5. Absence of CCL2 and CCL3 Ameliorates Central Nervous System Grey Matter But Not White Matter Demyelination in the Presence of an Intact Blood-Brain Barrier.

    Science.gov (United States)

    Janssen, Katharina; Rickert, Mira; Clarner, Tim; Beyer, Cordian; Kipp, Markus

    2016-04-01

    A broad spectrum of diseases is characterized by myelin abnormalities, oligodendrocyte pathology, and concomitant glia activation, among multiple sclerosis (MS). Our knowledge regarding the factors triggering gliosis and demyelination is scanty. Chemokines are pivotal for microglia and astrocyte activation and orchestrate critical steps during the formation of central nervous system (CNS) demyelinating lesions. Redundant functions of chemokines complicate, however, the study of their functional relevance. We used the cuprizone model to study redundant functions of two chemokines, CCL2/MCP1 and CCL3/MIP1α, which are critically involved in the pathological process of cuprizone-induced demyelination. First, we generated a mutant mouse strain lacking functional genes of both chemokines and demonstrated that double-mutant animals are viable, fertile, and do not present with gross abnormalities. Astrocytes and peritoneal macrophages, cultured form tissues of these animals did neither express CCL2 nor CCL3. Exposure to cuprizone resulted in increased CCL2 and CCL3 brain levels in wild-type but not mutant animals. Cuprizone-induced demyelination, oligodendrocyte loss, and astrogliosis were significantly ameliorated in the cortex but not corpus callosum of chemokine-deficient animals. In summary, we provide a novel powerful model to study the redundant function of two important chemokines. Our study reveals that chemokine function in the CNS redounds to region-specific pathophysiological events. PMID:25663168

  6. Blood Types

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Blood Types KidsHealth > For Teens > Blood Types Print A A ... or straight hair instead of curly. ...Make Eight Blood Types The different markers that can be found in ...

  7. Blood Types

    Science.gov (United States)

    ... confidence to respond in emergency situations with the skills that can help to save a life. Learn more » Red Cross Information Donating Blood Learn About Blood Hosting a Blood Drive For Hospitals Engage with Us About Us Media ...

  8. Plasma volume changes during hypoglycaemia

    DEFF Research Database (Denmark)

    Hilsted, J; Bendtsen, F; Christensen, N J;

    1990-01-01

    To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate of...... albumin in arterial and venous blood in seven healthy subjects before and during insulin-induced hypoglycaemia. In both vascular sites blood 51Cr content and the haematocrit increased, plasma volume and intravascular albumin content decreased and the transcapillary escape rate of albumin increased during...

  9. Immunoelectrophoresis - blood

    Science.gov (United States)

    IEP - serum; Immunoglobulin electrophoresis - blood; Gamma globulin electrophoresis; Serum immunoglobulin electrophoresis ... A blood sample is needed. For information on how this is done, see: Venipuncture

  10. Dose and Volume of the Irradiated Main Bronchi and Related Side Effects in the Treatment of Central Lung Tumors With Stereotactic Radiotherapy.

    Science.gov (United States)

    Duijm, Marloes; Schillemans, W; Aerts, Joachim G; Heijmen, B; Nuyttens, Joost J

    2016-04-01

    High radiation dose to the main bronchi can result in stenosis, occlusion or fistula formation, and death. Only 8 articles have reported side effects to the main bronchi from stereotactic body radiation therapy (SBRT), mostly with only one symptomatic complication per article. Therefore, we calculated the dose to the bronchial structures, such as trachea; mainstem bronchi; intermediate bronchus; upper-, middle-, and lower-lobe bronchus; and the segmental bronchi in 134 patients with central tumors and calculated the normal tissue complication probability (NTCP) for each of these structures, with toxicity determination based upon computed tomography imaging. No side effects were found in the trachea, and only stenosis occurred in the main bronchus and bronchus intermedius. Higher grades of side effects, such as occlusion and atelectasis, were only seen in the upper-, middle-, and lower bronchi and the segmental bronchi. When 0.5cc of a segmental bronchi was irradiated to 50Gy in 5 fractions, it was about 50% likely to be occluded radiographically. For grade 1 radiographically evident side effects, the 50% risk level for a 5-fraction Dmax was 55Gy for mid-bronchi and 65Gy for mainstem bronchi. To assure the relationship between clinical toxicity and side effects to the bronchi, further investigation is needed. PMID:27000511

  11. RCRA Facility Investigation/Remedial Investigation Report with Baseline Risk Assessment for the Central Shops Burning/Rubble Pit (631-6G), Volume 1 Final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The Burning/Rubble Pits at the Savannah River Site were usually shallow excavations approximately 3 to 4 meters in depth. Operations at the pits consisted of collecting waste on a continuous basis and burning on a monthly basis. The Central Shops Burning/Rubble Pit 631- 6G (BRP6G) was constructed in 1951 as an unlined earthen pit in surficial sediments for disposal of paper, lumber, cans and empty galvanized steel drums. The unit may have received other materials such as plastics, rubber, rags, cardboard, oil, degreasers, or drummed solvents. The BRP6G was operated from 1951 until 1955. After disposal activities ceased, the area was covered with soil. Hazardous substances, if present, may have migrated into the surrounding soil and/or groundwater. Because of this possibility, the United States Environmental Protection Agency (EPA) has designated the BRP6G as a Solid Waste Management Unit (SWMU) subject to the Resource Conservation Recovery Act/Comprehensive Environmental Response, Compensation and Liability Act (RCRA/CERCLA) process.

  12. Conceptual design of solar central-receiver hybrid power system: sodium-cooled-receiver concept. Volume I of II. Conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    A market analysis is reported consisting of estimates of overall market size derived from projections of electric power growth, examination of utility plans, and projections of potential regulatory action. Market share is projected by comparisons of the levelized costs of busbar power produced by hybrid coal solar units with costs of other electric power producers such as coal only, nuclear and solar only units. Parametric analyses of the major subsystems, consisting of the collector, receiver, storage, non-solar, electric power generation, and master control subsystems were conducted over a wide range of independent parameters in order to define subsystem operation and interfaces for use in the preferred system selection studies. The selection of the system, subsystems, and components of the 0.8 and 1.4 solar multiple sodium-cooled hybrid central receiver configurations were done. Technically feasible alternatives were compared on an economic basis. Detailed conceptual designs of the selected system concepts for the 0.8 and 1.4 solar multiple plants are presented. Cost estimates are also presented for both plants based on the conceptual designs. (LEW)

  13. Central receiver solar thermal power system, Phase 1: CDRL Item 2, pilot plant preliminary design report. Volume VII. Pilot plant cost and commercial plant cost and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1980-05-01

    Detailed cost and performance data for the proposed tower focus pilot plant and commercial plant are given. The baseline central receiver concept defined by the MDAC team consists of the following features: (A) an external receiver mounted on a tower, and located in a 360/sup 0/ array of sun-tracking heliostats which comprise the collector subsystem. (B) feedwater from the electrical power generation subsystem is pumped through a riser to the receiver, where the feedwater is converted to superheated steam in a single pass through the tubes of the receiver panels. (C) The steam from the receiver is routed through a downcomer to the ground and introduced to a turbine directly for expansion and generation of electricity, and/or to a thermal storage subsystem, where the steam is condensed in charging heat exchangers to heat a dual-medium oil and rock thermal storage unit (TSU). (D) Extended operation after daylight hours is facilitated by discharging the TSU to generate steam for feeding the admission port of the turbine. (E) Overall control of the system is provided by a master control unit, which handles the interactions between subsystems that take place during startup, shutdown, and transitions between operating modes. (WHK)

  14. A Case of Unrecognized Intrathoracic Placement of a Subclavian Central Venous Catheter in a Patient with Large Traumatic Hemothorax

    Directory of Open Access Journals (Sweden)

    Dina Wallin

    2015-01-01

    Full Text Available Traditional recommendations suggest placement of a subclavian central venous catheter (CVC ipsilateral to a known pneumothorax to minimize risk of bilateral pneumothorax. We present the case of a 65-year-old male with a right hemopneumothorax who was found to have intrathoracic placement of his right subclavian CVC at thoracotomy despite successful aspiration of blood and transduction of central venous pressure (CVP. We thus recommend extreme caution with the interpretation of CVC placement by blood aspiration and CVP measurement alone in patients with large volume ipsilateral hemothorax.

  15. Equações de volume para Eucalyptus dunnii Maiden, determinadas para a depressão central do Estado do Rio Grande do Sul Equations for Eucalyptus dunnii maiden volume determination on the central depression of State Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Paulo Renato Schneider

    1997-08-01

    Full Text Available O estudo foi realizado para definir equações de volume total com casca e comercial sem casca para Eucalyptus dunnii Maiden, na idade de 6,5 anos, implantado em espaçamento 3 x 2m. Foram cubadas, pelo método de Smaliam, 80 árvores distribuídas em classe diamétrica e de forma proporcional em quatro hortos florestais. As equações de volume total com casca e comercial sem casca foram determinadas através do procedimento "stepwise" de regressão, de forma independente, para cada local e, posteriormente, foi estudada a possibilidade de agrupamento destas equações em um modelo único. A análise de covariância aplicada aos dados indicou a possibilidade do emprego de uma única equação para estimar o volume da espécie em toda a região. Selecionou-se pelo alto coeficiente de determinação e baixo erro padrão da estimativa a equação log v = - 9,06566 + 0,93016 . log(d² h para o volume total com casca e log v = -14,14078 + 1,39608 . log(d² h para o volume comercial sem casca. Além disso, não observou-se diferenças na forma do tronco e por conseqüência no volume das árvores nos quatro locais estudados.This study has been carried out to define total bulk volume equations for Eucalyptus dunni Maiden, 6.5 years old, lined up along a 3 by 2 meter-spaced planted setting. These equations were supposed to both trees with and without bark. Eighty trees were cubed by Smalian's method distributed according to diameter classes and following a proportional way, over four forest sites. Equations were determinated through stepwise regression procedure, following an independent process for each site. A second step was evaluate the possiblility of these equations to be reduced into a single one. The covariance analysis applied to data showed the possibility of using an unique one equation to estimate the tree bulk volume to the region. Two equations were selected: one to calculate the total volume of trees with bark and another to determine the

  16. Perioperative neonatal and paediatric blood transfusion

    Directory of Open Access Journals (Sweden)

    Avnish Bharadwaj

    2014-01-01

    Full Text Available Paediatric patients undergoing surgical procedures commonly require some volume of blood or blood component replacement in the perioperative period. Paediatric patients undergoing major surgery associated with substantial blood loss should be evaluated pre-operatively. Pre-operative correction of anaemia may be done considering the age, plasma volume status, clinical status and comorbidities. Maximum allowable blood loss (MABL for surgery must be calculated, and appropriate quantity of blood and blood components should be arranged. Intraoperative monitoring of blood loss should be done, and volume of transfusion should be calculated in a protocol based manner considering the volemia and the trigger threshold for transfusion for the patient and the MABL. Early haemostasis should be achieved by judicious administration of red blood cells, blood components and pharmacological agents.

  17. Supine exercise restores arterial blood pressure and skin blood flow despite dehydration and hyperthermia.

    Science.gov (United States)

    González-Alonso, J; Mora-Rodríguez, R; Coyle, E F

    1999-08-01

    We determined whether the deleterious effects of dehydration and hyperthermia on cardiovascular function during upright exercise were attenuated by elevating central blood volume with supine exercise. Seven trained men [maximal oxygen consumption (VO(2 max)) 4.7 +/- 0. 4 l/min (mean +/- SE)] cycled for 30 min in the heat (35 degrees C) in the upright and in the supine positions (VO(2) 2.93 +/- 0.27 l/min) while maintaining euhydration by fluid ingestion or while being dehydrated by 5% of body weight after 2 h of upright exercise. When subjects were euhydrated, esophageal temperature (T(es)) was 37. 8-38.0 degrees C in both body postures. Dehydration caused equal hyperthermia during both upright and supine exercise (T(es) = 38. 7-38.8 degrees C). During upright exercise, dehydration lowered stroke volume (SV), cardiac output, mean arterial pressure (MAP), and cutaneous vascular conductance and increased heart rate and plasma catecholamines [30 +/- 6 ml, 3.0 +/- 0.7 l/min, 6 +/- 2 mmHg, 22 +/- 8%, 14 +/- 2 beats/min, and 50-96%, respectively; all P < 0. 05]. In contrast, during supine exercise, dehydration did not cause significant alterations in MAP, cutaneous vascular conductance, or plasma catecholamines. Furthermore, supine versus upright exercise attenuated the increases in heart rate (7 +/- 2 vs. 9 +/- 1%) and the reductions in SV (13 +/- 4 vs. 21 +/- 3%) and cardiac output (8 +/- 3 vs. 14 +/- 3%) (all P < 0.05). These results suggest that the decline in cutaneous vascular conductance and the increase in plasma norepinephrine concentration, independent of hyperthermia, are associated with a reduction in central blood volume and a lower arterial blood pressure. PMID:10444482

  18. Short and Long-Term Effects of the Angiotensin II Receptor Blocker Irbesartan on Intradialytic Central Hemodynamics: A Randomized Double-Blind Placebo-Controlled One-Year Intervention Trial (the SAFIR Study.

    Directory of Open Access Journals (Sweden)

    Christian Daugaard Peters

    Full Text Available Little is known about the tolerability of antihypertensive drugs during hemodialysis treatment. The present study evaluated the use of the angiotensin II receptor blocker (ARB irbesartan.Randomized, double-blind, placebo-controlled, one-year intervention trial.Eighty-two hemodialysis patients with urine output >300 mL/day and dialysis vintage <1 year.Irbesartan/placebo 300 mg/day for 12 months administered as add-on to antihypertensive treatment using a predialytic systolic blood pressure target of 140 mmHg in all patients.Cardiac output, stroke volume, central blood volume, total peripheral resistance, mean arterial blood pressure, and frequency of intradialytic hypotension.At baseline, the groups were similar regarding age, comorbidity, blood pressure, antihypertensive medication, ultrafiltration volume, and dialysis parameters. Over the one-year period, predialytic systolic blood pressure decreased significantly, but similarly in both groups. Mean start and mean end cardiac output, stroke volume, total peripheral resistance, heart rate, and mean arterial pressure were stable and similar in the two groups, whereas central blood volume increased slightly but similarly over time. The mean hemodynamic response observed during a dialysis session was a drop in cardiac output, in stroke volume, in mean arterial pressure, and in central blood volume, whereas heart rate increased. Total peripheral resistance did not change significantly. Overall, this pattern remained stable over time in both groups and was uninfluenced by ARB treatment. The total number of intradialytic hypotensive episodes was (placebo/ARB 50/63 (P = 0.4. Ultrafiltration volume, left ventricular mass index, plasma albumin, and change in intradialytic total peripheral resistance were significantly associated with intradialytic hypotension in a multivariate logistic regression analysis based on baseline parameters.Use of the ARB irbesartan as an add-on to other antihypertensive

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

    Science.gov (United States)

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

    1984-01-01

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

  20. 集中式清洗消毒采血持针器的效果分析%Effect of centralized cleaning and disinfection of blood collection needle holders

    Institute of Scientific and Technical Information of China (English)

    黄朝晖; 陈严伟; 何湘军; 高玉华

    2013-01-01

    OBJECTIVE To investigate the effect of centralized cleaning and disinfection of blood collection needle holders so as to standardize the cleaning and disinfection of the blood collection needle holders and ensure the safety of patients. METHODS A total of 1000 used blood collection needle holders were selected and randomly divided into two groups with 500 in each, the control group was treated by using conventional cleaning and disinfection method, with the needle holders immersed in 500 mg/L active chlorine solution for 30 minutes; while the study group was treated with multiple-enzyme fully automatic cleaning and disinfection machine. After the cleaning and disinfection, the cleanliness of the needles holders of the two groups was examined by visual observation, and the residual bacteria colony of the two groups was detected by ATP bioluminescence method. RESULTS After the cleaning and disinfection, the qualified rate of the visual examined cleanliness was 90. 2% in the control group and 98. 2% in the study group, while the qualified rate of the ATP content was 63. 2% in the control group and 100. 0% in the study group, the difference between the two was statistically significant (P < 0. 05). CONCLUSION The centralized cleaning and disinfection can not only standardize the cleaning and disinfection of the blood collection needle holders as well as the procedure of cleaning and disinfection by fully automatic cleaning machine, but also improve the quality of the cleaning and disinfection. It plays an important role in the control and prevention of nosocomial infections , with the human resource saved, the incidence of occupational exposure reduced, the work efficiency improved, and the cost cut.%目的 探讨集中式统一清洗消毒采血持针器的效果,以规范采血持针器清洗消毒的方法,确保患者安全.方法 选择使用过的采血持针器1000个,随机分为两组各500个,对照组使用传统式的清洗消毒法,用500 mg

  1. Technical efficiency of blood component preparation in blood centres of 10 European countries

    OpenAIRE

    Veihola, Marketta

    2008-01-01

    Various reasons, such as ethical issues in maintaining blood resources, growing costs, and strict requirements for safe blood, have increased the pressure for efficient use of resources in blood banking. The competence of blood establishments can be characterized by their ability to predict the volume of blood collection to be able to provide cellular blood components in a timely manner as dictated by hospital demand. The stochastically varying clinical need for platelets (PLTs) sets a specif...

  2. Cardiovascular and fluid volume control in humans in space

    DEFF Research Database (Denmark)

    Norsk, Peter

    2005-01-01

    The human cardiovascular system and regulation of fluid volume are heavily influenced by gravity. When decreasing the effects of gravity in humans such as by anti-orthostatic posture changes or immersion into water, venous return is increased by some 25%. This leads to central blood volume...... on this complex interaction, because it is the only way to completely abolish the effects of gravity over longer periods. Results from space have been unexpected, because astronauts exhibit a fluid and sodium retaining state with activation of the sympathetic nervous system, which subjects during...... simulations by head-down bed rest do not. Therefore, the concept as to how weightlessness affects the cardiovascular system and modulates regulation of body fluids should be revised and new simulation models developed. Knowledge as to how gravity and weightlessness modulate integrated fluid volume control is...

  3. Importance of the splanchnic vascular bed in human blood pressure regulation.

    Science.gov (United States)

    Rowell, L. B.; Detry, J.-M. R.; Blackmon, J. R.; Wyss, C.

    1972-01-01

    Three-part experiment in which five subjects were exposed to lower body negative pressure (LBNP) at -50 mm Hg below the iliac crests. Duration of LBNP to earliest vagal symptoms was 7 to 21 min; all data are expressed as changes from control period to the last measurements before these symptoms. In part I, forearm blood flow (by Whitney gauge) fell 45% during LBNP. In part II, splanchnic blood flow (from arterial clearance hepatic extraction of indocyanine green) fell 32% and splanchnic vascular resistance rose 30%. In part III, cardiac output fell 28%, stroke volume 51%, and central blood volume 21%. Total peripheral resistance and heart rate rose 19% and 52%. Of the reduction in total vascular conductance, decreased splanchnic conductance accounted for approximately 33%; skin plus muscle conductance decreased similarly.

  4. Artificial blood

    Directory of Open Access Journals (Sweden)

    Sarkar Suman

    2008-01-01

    Full Text Available Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  5. Use of blood and blood products.

    Science.gov (United States)

    Hunt, E; Wood, B

    1999-11-01

    It is sometimes necessary for the practitioner to transfuse the ruminant with whole blood or plasma. These techniques are often difficult to perform in practice, are time-consuming, expensive, and stressful to the animal. Acute loss of 20% to 25% of the blood volume will result in marked clinical signs of anemia, including tachycardia and maniacal behavior. The PCV is only a useful tool with which to monitor acute blood loss after intravascular equilibration with other fluid compartments has occurred. An acutely developing PCV of 15% or less may require transfusion. Chronic anemia with PCV of 7% to 12% can be tolerated without transfusion if the animal is not stressed and no further decline in erythrocyte mass occurs. Seventy-five percent of transfused bovine erythrocytes are destroyed within 48 hours of transfusion. A transfusion rate of 10 to 20 mL/kg recipient weight is necessary to result in any appreciable increase in PCV. A nonpregnant donor can contribute 10 to 15 mL of blood/kg body weight at 2- to 4-week intervals. Sodium citrate is an effective anticoagulant, but acid citrate dextrose should be used if blood is to be stored for more than a few hours. Blood should not be stored more than 2 weeks prior to administration. Heparin is an unsuitable anticoagulant because the quantity of heparin required for clot-free blood collection will lead to coagulation defects in the recipient. Blood cross-matching is only rarely performed in the ruminant. In field situations, it is advisable to inject 200 mL of donor blood into the adult recipient and wait 10 minutes. If no reaction occurs, the rest of the blood can probably be safely administered as long as volume overload problems do not develop. Adverse reactions are most commonly seen in very young animals or pregnant cattle. Signs of blood or plasma transfusion reaction include hiccoughing, tachycardia, tachypnea, sweating, muscle tremors, pruritus, salivation, cough, dyspnea, fever, lacrimation, hematuria

  6. Blood smear

    Science.gov (United States)

    ... osmotic fragility ) Deficiency of an enzyme called lecithin cholesterol acyl transferase Abnormalities of hemoglobin , the protein in ... sickle and Pappenheimer Red blood cells, target cells Formed elements of blood References Bain BJ. The peripheral ...

  7. The hydrostatic pressure indifference point underestimates orthostatic redistribution of blood in humans

    DEFF Research Database (Denmark)

    Petersen, L G; Carlsen, Jonathan F.; Nielsen, Michael Bachmann; Damgaard, M; Secher, N H

    2014-01-01

    ). During graded (± 20°) head-up (HUT) and head-down tilt (HDT) in 12 male volunteers, we determined HIP from central venous pressure and VIP from redistribution of both blood, using ultrasound imaging of the inferior caval vein (VIPui), and fluid volume, by regional electrical admittance (VIPadm...... of pressure and filling of the inferior caval vein as well as fluid distribution, we found HIP located corresponding to the diaphragm while VIP was placed low in the abdomen, and that medical antishock trousers elevated both HIP and VIP. The low indifference point for volume shows that the...

  8. Volume Entropy

    OpenAIRE

    Astuti, Valerio; Christodoulou, Marios; Rovelli, Carlo

    2016-01-01

    Building on a technical result by Brunnemann and Rideout on the spectrum of the Volume operator in Loop Quantum Gravity, we show that the dimension of the space of the quadrivalent states --with finite-volume individual nodes-- describing a region with total volume smaller than $V$, has \\emph{finite} dimension, bounded by $V \\log V$. This allows us to introduce the notion of "volume entropy": the von Neumann entropy associated to the measurement of volume.

  9. Continuous blood pressure monitoring in cirrhosis. Relations to splanchnic and systemic haemodynamics

    DEFF Research Database (Denmark)

    Møller, S; Christensen, E; Henriksen, Jens Henrik Sahl

    1997-01-01

    a high post-sinusoidal resistance, a low plasma volume, a short central circulation time, and the presence of ascites. In contrast, a low intra-arterial blood pressure was determined by a low serum sodium, a low haemoglobin, and a high cardiac output. Diuretic treatment did not influence this model......BACKGROUND/AIMS: Low arterial blood pressure is recognised as a distinctive factor in the hyperdynamic circulation in cirrhosis. 24-hour monitoring of the blood pressure and heart rate has recently revealed a reduced circadian variation with relation to liver function. However, associations with...... other clinical and haemodynamic characteristics have not been investigated and the aim of the present study was to identify splanchnic and systemic determinants of the 24-h blood pressure and heart rate in cirrhosis. METHODS: The variables were measured by an automatic ambulant device for monitoring...

  10. Radiolabelled Cellular Blood Elements

    International Nuclear Information System (INIS)

    This volume contains the abstracts of the 5th International Symposion on Radiolabelling of Cellular Blood Elements to be held in Vienna, Austria, September 10-14, 1989. The Meeting is the fifth in a series of meetings designed to discuss the basics and clinical application of radiolabelling techniques. In these days, beside the search for new labelling agents and extending the knowledge in clinical use, the use of monoclonal antibodies is a big new challenge. All reviewed contributions that have been accepted for presentation are contained in this volume. (authors) 58 of them are of INIS scope

  11. Cord Blood

    Directory of Open Access Journals (Sweden)

    Saeed Abroun

    2014-05-01

    Full Text Available   Stem cells are naïve or master cells. This means they can transform into special 200 cell types as needed by body, and each of these cells has just one function. Stem cells are found in many parts of the human body, although some sources have richer concentrations than others. Some excellent sources of stem cells, such as bone marrow, peripheral blood, cord blood, other tissue stem cells and human embryos, which last one are controversial and their use can be illegal in some countries. Cord blood is a sample of blood taken from a newborn baby's umbilical cord. It is a rich source of stem cells, umbilical cord blood and tissue are collected from material that normally has no use following a child’s birth. Umbilical cord blood and tissue cells are rich sources of stem cells, which have been used in the treatment of over 80 diseases including leukemia, lymphoma and anemia as bone marrow stem cell potency.  The most common disease category has been leukemia. The next largest group is inherited diseases. Patients with lymphoma, myelodysplasia and severe aplastic anemia have also been successfully transplanted with cord blood. Cord blood is obtained by syringing out the placenta through the umbilical cord at the time of childbirth, after the cord has been detached from the newborn. Collecting stem cells from umbilical blood and tissue is ethical, pain-free, safe and simple. When they are needed to treat your child later in life, there will be no rejection or incompatibility issues, as the procedure will be using their own cells. In contrast, stem cells from donors do have these potential problems. By consider about cord blood potency, cord blood banks (familial or public were established. In IRAN, four cord blood banks has activity, Shariati BMT center cord blood bank, Royan familial cord blood banks, Royan public cord blood banks and Iranian Blood Transfusion Organ cord blood banks. Despite 50,000 sample which storage in these banks, but the

  12. Integrated separation of blood plasma from whole blood for microfluidic paper-based analytical devices.

    Science.gov (United States)

    Yang, Xiaoxi; Forouzan, Omid; Brown, Theodore P; Shevkoplyas, Sergey S

    2012-01-21

    Many diagnostic tests in a conventional clinical laboratory are performed on blood plasma because changes in its composition often reflect the current status of pathological processes throughout the body. Recently, a significant research effort has been invested into the development of microfluidic paper-based analytical devices (μPADs) implementing these conventional laboratory tests for point-of-care diagnostics in resource-limited settings. This paper describes the use of red blood cell (RBC) agglutination for separating plasma from finger-prick volumes of whole blood directly in paper, and demonstrates the utility of this approach by integrating plasma separation and a colorimetric assay in a single μPAD. The μPAD was fabricated by printing its pattern onto chromatography paper with a solid ink (wax) printer and melting the ink to create hydrophobic barriers spanning through the entire thickness of the paper substrate. The μPAD was functionalized by spotting agglutinating antibodies onto the plasma separation zone in the center and the reagents of the colorimetric assay onto the test readout zones on the periphery of the device. To operate the μPAD, a drop of whole blood was placed directly onto the plasma separation zone of the device. RBCs in the whole blood sample agglutinated and remained in the central zone, while separated plasma wicked through the paper substrate into the test readout zones where analyte in plasma reacted with the reagents of the colorimetric assay to produce a visible color change. The color change was digitized with a portable scanner and converted to concentration values using a calibration curve. The purity and yield of separated plasma was sufficient for successful operation of the μPAD. This approach to plasma separation based on RBC agglutination will be particularly useful for designing fully integrated μPADs operating directly on small samples of whole blood. PMID:22094609

  13. The clot burden score, the Boston Acute Stroke Imaging Scale, the cerebral blood volume ASPECTS, and two novel imaging parameters in the prediction of clinical outcome of ischemic stroke patients receiving intravenous thrombolytic therapy

    International Nuclear Information System (INIS)

    Recently two classification methods based on the location and the extent of thrombosis detected with CT angiography have been introduced: the Boston Acute Stroke Imaging Scale (BASIS) and the clot burden score (CBS). We studied the performance of BASIS and CBS in predicting good clinical outcome (mRS ≤2 at 90 days) in an acute (<3 h) stroke cohort treated with intravenous thrombolytic therapy. Eighty-three consecutive patients who underwent multimodal CT were analyzed. Binary logistic regression model was used to assess how BASIS, CBS, and cerebral blood volume (CBV) ASPECTS predict favorable clinical outcome. Diagnostic sensitivities and specificities were calculated and compared. Patients with low CBS and CBV ASPECTS scores and major strokes according to BASIS had significantly higher admission NIHSS scores, larger perfusion defects, and more often poor clinical outcome. In logistic regression analysis, CBV ASPECTS, CBS and BASIS were significantly associated with the clinical outcome. The performance of BASIS improved when patients with thrombosis of the M2 segment of the middle cerebral artery were classified as having minor stroke (M1-BASIS). In the anterior circulation, the sum of CBS and CBV ASPECTS (CBSV) proved to be the most robust predictor of favorable outcome. CBV ASPECTS and CBS had high sensitivity but moderate to poor specificity while BASIS was only moderately sensitive and specific. CBS, BASIS, and CBV ASPECTS are statistically robust and sensitive but unspecific predictors of good clinical outcome. Two new derived imaging parameters, CBSV and M1-BASIS, share these properties and may have increased prognostic value. (orig.)

  14. The clot burden score, the Boston Acute Stroke Imaging Scale, the cerebral blood volume ASPECTS, and two novel imaging parameters in the prediction of clinical outcome of ischemic stroke patients receiving intravenous thrombolytic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sillanpaa, Niko; Hakomaki, Jari; Lahteela, Arto; Dastidar, Prasun; Soimakallio, Seppo [Tampere University Hospital, Medical Imaging Center, Tampere (Finland); Saarinen, Jukka T.; Numminen, Heikki; Elovaara, Irina [Tampere University Hospital, Department of Neurology, Tampere (Finland); Rusanen, Harri [Oulu University Hospital, Department of Neurology, Oulu (Finland)

    2012-07-15

    Recently two classification methods based on the location and the extent of thrombosis detected with CT angiography have been introduced: the Boston Acute Stroke Imaging Scale (BASIS) and the clot burden score (CBS). We studied the performance of BASIS and CBS in predicting good clinical outcome (mRS {<=}2 at 90 days) in an acute (<3 h) stroke cohort treated with intravenous thrombolytic therapy. Eighty-three consecutive patients who underwent multimodal CT were analyzed. Binary logistic regression model was used to assess how BASIS, CBS, and cerebral blood volume (CBV) ASPECTS predict favorable clinical outcome. Diagnostic sensitivities and specificities were calculated and compared. Patients with low CBS and CBV ASPECTS scores and major strokes according to BASIS had significantly higher admission NIHSS scores, larger perfusion defects, and more often poor clinical outcome. In logistic regression analysis, CBV ASPECTS, CBS and BASIS were significantly associated with the clinical outcome. The performance of BASIS improved when patients with thrombosis of the M2 segment of the middle cerebral artery were classified as having minor stroke (M1-BASIS). In the anterior circulation, the sum of CBS and CBV ASPECTS (CBSV) proved to be the most robust predictor of favorable outcome. CBV ASPECTS and CBS had high sensitivity but moderate to poor specificity while BASIS was only moderately sensitive and specific. CBS, BASIS, and CBV ASPECTS are statistically robust and sensitive but unspecific predictors of good clinical outcome. Two new derived imaging parameters, CBSV and M1-BASIS, share these properties and may have increased prognostic value. (orig.)

  15. Significant association between ABO blood group and pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Julia; B; Greer; Mark; H; Yazer; Jay; S; Raval; M; Michael; Barmada; Randall; E; Brand; David; C; Whitcomb

    2010-01-01

    AIM:To evaluate whether the ABO blood group is related to pancreatic cancer risk in the general population of the United States.METHODS:Using the University of Pittsburgh's clinicalpancreatic cancer registry,the blood donor database from our local blood bank (Central Blood Bank),and the blood product recipient database from the regional transfusion service (Centralized Transfusion Service) in Pittsburgh,Pennsylvania,we identified 274 pancreatic cancer patients with previously determined serological ABO bloo...

  16. Assessing intravascular volume by difference in pulse pressure in pigs submitted to graded hemorrhage.

    Science.gov (United States)

    Pestel, Gunther J; Hiltebrand, Luzius B; Fukui, Kimiko; Cohen, Delphine; Hager, Helmut; Kurz, Andrea M

    2006-10-01

    We assessed changes in intravascular volume monitored by difference in pulse pressure (dPP%) after stepwise hemorrhage in an experimental pig model. Six pigs (23-25 kg) were anesthetized (isoflurane 1.5 vol%) and mechanically ventilated to keep end-tidal CO2 (etCO2) at 35 mmHg. A PA-catheter and an arterial catheter were placed via femoral access. During and after surgery, animals received lactated Ringer's solution as long as they were considered volume responders (dPP>13%). Then animals were allowed to stabilize from the induction of anesthesia and insertion of catheters for 30 min. After stabilization, baseline measurements were taken. Five percent of blood volume was withdrawn, followed by another 5%, and then in 10%-increments until death from exsanguination occurred. After withdrawal of 5% of blood volume, all pigs were considered volume responders (dPP>13%); dPP rose significantly from 6.1+/-3.3% to 19.4+/-4.2%. The regression analysis of stepwise hemorrhage revealed a linear relation between blood loss (hemorrhage in %) and dPP (y=0.99*x+14; R2=0.7764; P<.0001). In addition, dPP was the only parameter that changed significantly between baseline and a blood loss of 5% (P<0.01), whereas cardiac output, stroke volume, heart rate, MAP, central venous pressure, pulmonary artery occlusion pressure, and systemic vascular resistance, respectively, remained unchanged. We conclude that in an experimental hypovolemic pig model, dPP correlates well with blood loss. PMID:16980887

  17. Blood / Money

    OpenAIRE

    Strong, Thomas

    1997-01-01

    Marilyn Strathern has argued that "nature" in Euro-American culture has appeared as constraint; it has figured the givens of existence on which human artifice is seen to construct "society" or "culture."(5) Among those givens is the notion that human beings are naturally individuals. And blood, too, images individuality: "The very thought of blood, individual blood, touches the deepest feelings in man about life and death" ([RIchard Titmuss] 16.) Transfusion medicine, then, draws on a series ...

  18. Studies of deionization and impedance spectroscopy for blood analyzer

    Science.gov (United States)

    Kwong, Charlotte C.; Li, Nan; Ho, Chih-Ming

    2005-11-01

    Blood analysis provides vital information for health conditions. For instance, typical infection response is correlated to an elevated White Blood Cell (WBC) count, while low Red Blood Cell (RBC) count, hemoglobin and hematocrit are caused by anemia or internal bleeding. We are developing two essential modules, deionization (DI) chip and microfluidic cytometer with impedance spectroscopy flow, for enabling the realization of a single platform miniaturized blood analyzer. In the proposed analyzer, blood cells are preliminarily sorted by Dielectrophoretic (DEP) means into sub-groups, differentiated and counted by impedance spectroscopy in a flow cytometer. DEP techniques have been demonstrated to stretch DNA, align Carbon Nanotubes (CNT) and trap cells successfully. However, DEP manipulation does not function in biological media with high conductivity. The DI module is designed to account for this challenge. H Filter will serve as an ion extraction platform in a microchamber. Sample and buffer do not mix well in micro scale allowing the ions being extracted by diffusion without increasing the volume. This can keep the downstream processing time short. Micro scale hydrodynamic focusing is employed to place single cell passing along the central plane of the flow cytometer module. By applying an AC electrical field, suspended cells are polarized, membrane capacitance C m, cytoplasm conductivity σ c, and cytoplasm permittivity ɛ c will vary as functions of frequency. Tracing back the monitored current, the numbers of individual cell species can be evaluated.

  19. Blood donor management in china.

    Science.gov (United States)

    Shi, Ling; Wang, Jingxing; Liu, Zhong; Stevens, Lori; Sadler, Andrew; Ness, Paul; Shan, Hua

    2014-07-01

    Despite a steady increase in total blood collections and voluntary non-remunerated blood donors, China continues to have many challenges with its blood donation system. The country's donation rate remains low at 9%o, with over 60% of donors being first-time donors. Generally there is a lack of adequate public awareness about blood donation. The conservative donor selection criteria, the relatively long donation interval, and the small donation volume have further limited blood supply. To ensure a sufficient and safe blood supply that meets the increasing clinical need for blood products, there is an urgent need to strengthen the country's blood donor management. This comprehensive effort should include educating and motivating more individuals especially from the rural areas to be involved in blood donation, developing rational and evidence-based selection criteria for donor eligibility, designing a donor follow-up mechanism to encourage more future donations, assessing the current donor testing strategy, improving donor service and care, building regional and national shared donor deferral database, and enhancing the transparency of the blood donation system to gain more trust from the general public. The purpose of the review is to provide an overview of the key process of and challenges with the blood donor management system in China. PMID:25254023

  20. Human blood glucose dynamics

    OpenAIRE

    Rahaghi, Farbod N.

    2007-01-01

    The control of blood glucose concentration has become central to the prevention of morbidity in diabetes. Currently sensors are becoming available to make available near continuous measurements of tissue glucose concentrations. Frequently measured values provide an opportunity to analyze the dynamics of these measurements in addition to statistical analysis. The dynamics can be used to verify sensor validity, to provide a physiologic control target, and serve as a tool to diagnose and monitor...