Investigation of venous blood cells parameters among 1180 healthy people in Tianjin area

International Nuclear Information System (INIS)

Jiang Liping; Hao Jianxiu; Li Jin; Xing Zhiwei; Zhao Xinran; Jiang Bo; Wang Xiaoguang; Jiang Enhai

2013-01-01

Objective: To investigate the reference values of 18 parameters of venous blood cells among healthy adults in Tianjin area. Methods: The values of 18 parameters of venous blood from 1180 healthy adults in Tianjin area were measured by Sysmex KX-21 hematology analyzer and the results were analyzed. Results: The statistical analysis of the test reveals that significant differences exist in most parameters of venous blood cells according to the gender and age of people. Except the parameters of mean corpuscular volume, lymphocytes percentage, mean platelet volume, platelet distribution width,there were significant differences in the remaining parameters between the males group and the females group. Except the parameters of white blood count,platelet count, mean corpuscular hemoglobin, neutrophil percentage,absolute neutrophil count, mean platelet volume, platelet distribution width, there were significant differences in the remaining parameters between the old male group and the adult male group. Except the parameters of white blood count, mean corpuscular volume, mean corpuscular hemoglobin, there was no significant difference in the remaining parameters between the old female group and the adult female group. Conclusions: There are some differences between the findings and the reference range provided by the National Guide to Clinical laboratory Procedure. Therefore, it is necessary for laboratory to establish the reference values of venous blood cells according to concrete conditions. (authors)

Central venous oxygen saturation during hypovolaemic shock in humans

DEFF Research Database (Denmark)

Madsen, P; Iversen, H; Secher, N H

1993-01-01

We compared central venous oxygen saturation and central venous pressure (CVP) as indices of the effective blood volume during 50 degrees head-up tilt (anti-Trendelenburg's position) induced hypovolaemic shock in eight healthy subjects. Head-up tilt increased thoracic electrical impedance from 31...... (28-36) (median and range) to 34 (30-40) Ohm, mean arterial pressure (MAP) from 79 (70-88) to 86 (80-99) mmHg, heart rate (HR) from 67 (56-71) to 99 (78-119) beats min-1 (p ....05) but thereafter remained stable. In contrast, central venous oxygen saturation showed a linear decrease with time from 0.75 (0.69-0.78) at rest to 0.60 (0.49-0.67) (p measurement of central venous oxygen saturation...

Vasopressin-induced changes in splanchnic blood flow and hepatic and portal venous pressures in liver resection.

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Bown, L Sand; Ricksten, S-E; Houltz, E; Einarsson, H; Söndergaard, S; Rizell, M; Lundin, S

2016-05-01

To minimize blood loss during hepatic surgery, various methods are used to reduce pressure and flow within the hepato-splanchnic circulation. In this study, the effect of low- to moderate doses of vasopressin, a potent splanchnic vasoconstrictor, on changes in portal and hepatic venous pressures and splanchnic and hepato-splanchnic blood flows were assessed in elective liver resection surgery. Twelve patients were studied. Cardiac output (CO), stroke volume (SV), mean arterial (MAP), central venous (CVP), portal venous (PVP) and hepatic venous pressures (HVP) were measured, intraoperatively, at baseline and during vasopressin infusion at two infusion rates (2.4 and 4.8 U/h). From arterial and venous blood gases, the portal (splanchnic) and hepato-splanchnic blood flow changes were calculated, using Fick's equation. CO, SV, MAP and CVP increased slightly, but significantly, while systemic vascular resistance and heart rate remained unchanged at the highest infusion rate of vasopressin. PVP was not affected by vasopressin, while HVP increased slightly. Vasopressin infusion at 2.4 and 4.8 U/h reduced portal blood flow (-26% and -37%, respectively) and to a lesser extent hepato-splanchnic blood flow (-9% and -14%, respectively). The arterial-portal vein lactate gradient was not significantly affected by vasopressin. Postoperative serum creatinine was not affected by vasopressin. Short-term low to moderate infusion rates of vasopressin induced a splanchnic vasoconstriction without metabolic signs of splanchnic hypoperfusion or subsequent renal impairment. Vasopressin caused a centralization of blood volume and increased cardiac output. Vasopressin does not lower portal or hepatic venous pressures in this clinical setting. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

ABO blood groups and risk of deep venous thromboembolism in Chinese Han population from Chaoshan region in South China

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Min Yu

2017-04-01

Full Text Available Objectives: To demonstrate the prevalence of ABO blood groups with deep venous thromboembolism in Chinese Han population. Methods: A retrospective study was conducted between January 2010 and March 2015 in The First Affiliated Hospital of Shantou University Medical College in Chaoshan District of Guangdong Province in South China. Eighty nine patients with confirmed diagnosis of deep venous thromboembolism were included. Frequency of blood groups was determined. Results: Of 89 patients with deep venous thromboembolism, 28 patients had blood group A (31.5%, 28 patients had blood group B (31.5%, 13 patients had blood group AB (14.6%, and 20 patients had blood group O (22.5%. Compared with O blood type, the odds ratios of deep venous thromboembolism for A, B and AB were 2.23 (95% CI, 1.27-3.91, 2.34 (95% CI, 1.34-4.09 and 4.43 (95% CI, 2.24-8.76. Conclusion: There is a higher risk of venous thromboembolism in non-O blood groups than O group.

ABO blood groups and risk of deep venous thromboembolism in Chinese Han population from Chaoshan region in South China.

Science.gov (United States)

Yu, Min; Wang, Cantian; Chen, Tingting; Hu, Shuang; Yi, Kaihong; Tan, Xuerui

2017-04-01

 Objectives: To demonstrate the prevalence of ABO blood groups with deep venous thromboembolism in Chinese Han population. A retrospective study was conducted between January 2010 and March 2015 in The First Affiliated Hospital of Shantou University Medical College in Chaoshan District of Guangdong Province in South China. Eighty nine patients with confirmed diagnosis of deep venous thromboembolism were included. Frequency of blood groups was determined. Results: Of 89 patients with deep venous thromboembolism, 28 patients had blood group A (31.5%), 28 patients had blood group B (31.5%), 13 patients had blood group AB (14.6%), and 20 patients had blood group O (22.5%). Compared with O blood type, the odds ratios of deep venous thromboembolism for A, B and AB were 2.23 (95% CI, 1.27-3.91), 2.34 (95% CI, 1.34-4.09) and  4.43 (95% CI, 2.24-8.76). Conclusion: There is a higher risk of venous thromboembolism in non-O blood groups than O group.

Vasopressin and nitroglycerin decrease portal and hepatic venous pressure and hepato-splanchnic blood flow.

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Wisén, E; Svennerholm, K; Bown, L S; Houltz, E; Rizell, M; Lundin, S; Ricksten, S-E

2018-03-26

Various methods are used to reduce venous blood pressure in the hepato-splanchnic circulation, and hence minimise blood loss during liver surgery. Previous studies show that combination of vasopressin and nitroglycerin reduces portal pressure and flow in patients with portal hypertension, and in this study we investigated this combination in patients with normal portal pressure. In all, 13 patients were studied. Measurements were made twice to confirm baseline (C1 and BL), during vasopressin infusion 4.8 U/h (V), and during vasopressin infusion combined with nitroglycerin infusion (V + N). Portal venous pressure (PVP), hepatic venous pressure (HVP), central haemodynamics and arterial and venous blood gases were obtained at each measuring point, and portal (splanchnic) and hepato-splanchnic blood flow changes were calculated. Vasopressin alone did not affect PVP, whereas HVP increased slightly. In combination with nitroglycerin, PVP decreased from 10.1 ± 1.6 to 8.9 ± 1.3 mmHg (P HVP decreased from 7.9 ± 1.9 to 6.2 ± 1.3 mmHg (P = 0.001). Vasopressin reduced portal blood flow by 47 ± 19% and hepatic venous flow by 11 ± 18%, respectively. Addition of nitroglycerin further reduced portal- and hepatic flow by 55 ± 13% and 30 ± 13%, respectively. Vasopressin alone had minor effects on central haemodynamics, whereas addition of nitroglycerin reduced cardiac index (3.2 ± 0.7 to 2.7 ± 0.5; P < 0.0001). The arterial-portal vein lactate gradient was unaffected. The combination of vasopressin and nitroglycerin decreases portal pressure and hepato-splanchnic blood flow, and could be a potential treatment to reduce bleeding in liver resection surgery. © 2018 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

A simple method for measurement of cerebral blood flow using 123I-IMP SPECT with calibrated standard input function by one point blood sampling. Validation of calibration by one point venous blood sampling as a substitute for arterial blood sampling

International Nuclear Information System (INIS)

Ito, Hiroshi; Akaizawa, Takashi; Goto, Ryoui

1994-01-01

In a simplified method for measurement of cerebral blood flow using one 123 I-IMP SPECT scan and one point arterial blood sampling (Autoradiography method), input function is obtained by calibrating a standard input function by one point arterial blood sampling. A purpose of this study is validation of calibration by one point venous blood sampling as a substitute for one point arterial blood sampling. After intravenous infusion of 123 I-IMP, frequent arterial and venous blood sampling were simultaneously performed on 12 patients of CNS disease without any heart and lung disease and 5 normal volunteers. The radioactivity ratio of venous whole blood which obtained from cutaneous cubital vein to arterial whole blood were 0.76±0.08, 0.80±0.05, 0.81±0.06, 0.83±0.11 at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivities were always 20% lower than those of arterial blood radioactivity during 50 min. However, the ratio which obtained from cutaneous dorsal hand vein to artery were 0.93±0.02, 0.94±0.05, 0.98±0.04, 0.98±0.03, at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivity was consistent with artery. These indicate that arterio-venous difference of radioactivity in a peripheral cutaneous vein like a dorsal hand vein is minimal due to arteriovenous shunt in palm. Therefore, a substitution by blood sampling from cutaneous dorsal hand vein for artery will be possible. Optimized time for venous blood sampling evaluated by error analysis was 20 min after 123 I-IMP infusion, which is 10 min later than that of arterial blood sampling. (author)

Retinal venous blood carbon monoxide response to bright light in male pigs: A preliminary study.

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Oren, Dan A; Duda, Magdalena; Kozioł, Katarzyna; Romerowicz-Misielak, Maria; Koziorowska, Anna; Sołek, Przemysław; Nowak, Sławomir; Kulpa, Magdalena; Koziorowski, Marek

2017-03-01

The physical mechanism by which light is absorbed in the eye and has antidepressant and energizing effects in Seasonal Affective Disorder and other forms of psychiatric major depression is of scientific interest. This study was designed to explore one specific aspect of a proposed humoral phototransduction mechanism, namely that carbon monoxide (CO) levels increase in retinal venous blood in response to bright light. Eleven mature male pigs approximately six months of age were kept for 7days in darkness and fasted for 12h prior to surgery. Following mild sedation, anesthesia was induced. Silastic catheters were inserted into the dorsal nasal vein through the angular vein of the eye to reach the ophthalmic sinus, from which venous blood outflowing from the eye area was collected. The animals were exposed to 5000lx of fluorescent-generated white light. CO levels in the blood were analyzed by gas chromatography before and after 80min of light exposure. At baseline, mean CO levels in the retinal venous blood were 0.43±0.05(SE)nmol/ml. After bright light, mean CO levels increased to 0.54±0.06nmol/ml (two-tailed t-test plight exposure raises carbon monoxide levels in ophthalmic venous blood. Copyright © 2017 Elsevier B.V. All rights reserved.

Child Abuse, Resting Blood Pressure, and Blood Pressure Reactivity to Psychosocial Stress.

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Gooding, Holly C; Milliren, Carly E; Austin, S Bryn; Sheridan, Margaret A; McLaughlin, Katie A

2016-01-01

Childhood trauma is associated with hypertension in adults. It is unknown whether childhood trauma predicts elevated blood pressure earlier in development. We investigated whether the trauma of child abuse was associated with blood pressure in adolescents. The sample included 145 adolescents aged 13-17 years, 40% with exposure to child abuse. The mean age of participants was 14.93 years (SD = 1.33); 58% were female. The majority self-identified as non-Hispanic White (43%), with the remainder identifying as non-Hispanic Black (17%), Hispanic (17%), or other/mixed race (23%). We used established age/sex/height-specific cutoffs to determine the prevalence of prehypertension and hypertension in the sample. We used two-sample t tests to examine associations of abuse with resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) and blood pressure reactivity to the Trier Social Stress Test and a frustration task. We used linear regression to adjust for potential confounders including sociodemographic variables, body mass index, smoking, and psychopathology. Mean resting SBP and DBP were 114.07 mmHg and 61.35 mmHg in those with a history of abuse and 111.39 mmHg and 56.89 mmHg in those without a history of abuse. This difference was significant for DBP only. Twelve percent of participants met criteria for prehypertension or hypertension based on resting blood pressure values; this did not differ between those with and without an abuse history. Child abuse was associated with lower DBP and SBP reactivity to laboratory stress tasks and reduced DBP reactivity to frustration. These associations were robust to adjustment for potential confounders. Child abuse is associated with higher resting DBP and blunted DBP and SBP reactivity to laboratory stress in adolescence. These findings suggest a potential pathway by which child abuse leads to hypertension. © The Author 2015. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All

Calculating acid-base and oxygenation status during COPD exacerbation using mathematically arterialised venous blood

DEFF Research Database (Denmark)

Rees, Stephen Edward; Rychwicka-Kielek, Beate A; Andersen, Bjarne F

2012-01-01

Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission...... for exacerbation of chronic obstructive pulmonary disease (COPD). Methods: Simultaneous arterial and peripheral venous blood was analysed. Venous values were used to calculate arterial pH, PCO2 and PO2, with these compared to measured values using Bland-Altman analysis and scatter plots. Calculated values of PO2......H, PCO2 and PO2 were 7.432±0.047, 6.8±1.7 kPa and 9.2±1.5 kPa, respectively. Calculated and measured arterial pH and PCO2 agreed well, differences having small bias and SD (0.000±0.022 pH, -0.06±0.50 kPa PCO2), significantly better than venous blood alone. Calculated PO2 obeyed the clinical rules...

Order of draw practices in venous blood sampling at clinical biochemistry departments in the Danish health care system

DEFF Research Database (Denmark)

Jacobsen, Katja Kemp; Brandt, Ida; Christensen, Anne Vindahl

2018-01-01

the procedures in venous blood sampling among clinical biochemistry departments to assess the uniformity of order of blood draw and adherence to international guidelines in the Danish health care system. METHODS: We collected venous order of draw procedures from 49 clinical biochemistry departments at 22 public...... 15189:2012 accreditation (p = .57). CONCLUSIONS: Venous order of draw procedures is diverse at Danish clinical biochemistry departments and show moderate adherence to international guidelines....

Do the venous blood samples replicate malaria parasite densities found in capillary blood? A field study performed in naturally-infected asymptomatic children in Cameroon.

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Sandeu, Maurice M; Bayibéki, Albert N; Tchioffo, Majoline T; Abate, Luc; Gimonneau, Geoffrey; Awono-Ambéné, Parfait H; Nsango, Sandrine E; Diallo, Diadier; Berry, Antoine; Texier, Gaétan; Morlais, Isabelle

2017-08-17

The measure of new drug- or vaccine-based approaches for malaria control is based on direct membrane feeding assays (DMFAs) where gametocyte-infected blood samples are offered to mosquitoes through an artificial feeder system. Gametocyte donors are identified by the microscopic detection and quantification of malaria blood stages on blood films prepared using either capillary or venous blood. However, parasites are known to sequester in the microvasculature and this phenomenon may alter accurate detection of parasites in blood films. The blood source may then impact the success of mosquito feeding experiments and investigations are needed for the implementation of DMFAs under natural conditions. Thick blood smears were prepared from blood obtained from asymptomatic children attending primary schools in the vicinity of Mfou (Cameroon) over four transmission seasons. Parasite densities were determined microscopically from capillary and venous blood for 137 naturally-infected gametocyte carriers. The effect of the blood source on gametocyte and asexual stage densities was then assessed by fitting cumulative link mixed models (CLMM). DMFAs were performed to compare the infectiousness of gametocytes from the different blood sources to mosquitoes. Prevalence of Plasmodium falciparum asexual stages among asymptomatic children aged from 4 to 15 years was 51.8% (2116/4087). The overall prevalence of P. falciparum gametocyte carriage was 8.9% and varied from one school to another. No difference in the density of gametocyte and asexual stages was found between capillary and venous blood. Attempts to perform DMFAs with capillary blood failed. Plasmodium falciparum malaria parasite densities do not differ between capillary and venous blood in asymptomatic subjects for both gametocyte and trophozoite stages. This finding suggests that the blood source should not interfere with transmission efficiency in DMFAs.

Substitution of Fingertip Blood for Venous Blood in the Measurement of Hematocrit and Hemoglobin Following Exercise

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Fahey, Thomas D.; And Others

1977-01-01

Results from comparative testing indicate that fingertip blood is a valid indicator of antecubital venous hematocrit (hct) and hemoglobin (hgb), and that hct ratios determined on the Coulter counter are comparable to those found by the microhematocrit method. (MB)

Venous ulcers -- self-care

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... surgery to improve blood flow through your veins. Prevention If you are at risk for venous ulcers, take the steps listed above under Wound Care. ... weight if you are overweight. Manage your blood pressure and cholesterol levels. ... Venous leg ulcers - self-care; Venous insufficiency ulcers - self-care; Stasis ...

Arterio-venous flow between monochorionic twins determined during intra-uterine transfusion. Nonlinear decay of adult red blood cells

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Gemert, Martin J C van; Wijngaard, Jeroen P H M van den [Laser Centre and Department of Obstetrics, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Pasman, Suzanne A; Vandenbussche, Frank P H A [Division of Fetal Medicine, Department of Obstetrics, Leiden University Medical Centre, Leiden (Netherlands); Lopriore, Enrico [Division of Neonatology, Department of Pediatrics, Leiden University Medical Centre, Leiden (Netherlands)], E-mail: m.j.vangemert@amc.uva.nl

2008-07-07

Recently, we derived equations relating the flow of adult red blood cells through a placental arterio-venous anastomosis with intra-uterine and post-natal measured adult hemoglobin concentrations. In this letter, we re-derived the equations, now including a more realistic nonlinear decay of adult red blood cells, and re-evaluated the measurement accuracy of the arterio-venous flow and the lifetime of the red blood cells. (letter to the editor)

Mercury levels in cord blood and meconium of healthy newborns and venous blood of their mothers: Clinical, prospective cohort study

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Unuvar, Emin [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey)]. E-mail: Eunuvar@superonline.com; Ahmadov, Hasan [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey); Kiziler, Ali Riza [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey); Istanbul University, Cerrahpasa Medical Faculty, Department of Biophysics, Istanbul (Turkey); Aydemir, Birsen [Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul (Turkey); Istanbul University, Cerrahpasa Medical Faculty, Department of Biophysics, Istanbul (Turkey); Toprak, Sadik [Gazi Osman Pasa University, Department of Forensic Pathology, Tokat (Turkey); Ulker, Volkan [Bakirkoy Government Hospital, Istanbul (Turkey); Ark, Cemal [Bakirkoy Government Hospital, Istanbul (Turkey)

2007-03-01

Objectives: The purpose of this study is to investigate the chronic mercury intoxication in pregnant women and newborns living in Istanbul, Turkey. Methods: The research was carried out as a prospective with 143 pregnant women and their newborns. Venous blood from the mother, cord blood from the neonate, and meconium were collected for mercury analysis. Frequency of fish and vegetable-eating and the number of teeth filled were investigated. Analyses were made in cold vapor Atomic Absorption Spectrophotometer (AAS, {mu}g/L). Results: Mercury levels were 0.38 {+-} 0.5 {mu}g/L (0-2.34) in venous blood of pregnant women, 0.50 {+-} 0.64 {mu}g/L (0-2.36) in umbilical cord blood and 9.45 {+-} 13.8 {mu}g/g (0-66.5) in meconium. Maternal blood mercury level was lower than the known toxic limit for humans (EPA, 5 {mu}g/L). Mercury levels of the maternal venous blood were significantly correlated with umbilical cord blood. The primary risk factors affecting mercury levels were eating fishmeals more than twice a week and having filled teeth more than five. The fact that the mother had a regular vegetable diet everyday reduced the mercury levels. Increased levels of mercury in the mother and umbilical cord blood could lead to retarded newborns' weight and height. Conclusion: Pregnant women living in Istanbul may be not under the risk of chronic mercury intoxication. Fish consumption more than twice per week and tooth-filling of mother more than five may increase mercury level. On the contrary, regular diet rich in vegetable decreases the mercury level.

Mercury levels in cord blood and meconium of healthy newborns and venous blood of their mothers: Clinical, prospective cohort study

International Nuclear Information System (INIS)

Unuvar, Emin; Ahmadov, Hasan; Kiziler, Ali Riza; Aydemir, Birsen; Toprak, Sadik; Ulker, Volkan; Ark, Cemal

2007-01-01

Objectives: The purpose of this study is to investigate the chronic mercury intoxication in pregnant women and newborns living in Istanbul, Turkey. Methods: The research was carried out as a prospective with 143 pregnant women and their newborns. Venous blood from the mother, cord blood from the neonate, and meconium were collected for mercury analysis. Frequency of fish and vegetable-eating and the number of teeth filled were investigated. Analyses were made in cold vapor Atomic Absorption Spectrophotometer (AAS, μg/L). Results: Mercury levels were 0.38 ± 0.5 μg/L (0-2.34) in venous blood of pregnant women, 0.50 ± 0.64 μg/L (0-2.36) in umbilical cord blood and 9.45 ± 13.8 μg/g (0-66.5) in meconium. Maternal blood mercury level was lower than the known toxic limit for humans (EPA, 5 μg/L). Mercury levels of the maternal venous blood were significantly correlated with umbilical cord blood. The primary risk factors affecting mercury levels were eating fishmeals more than twice a week and having filled teeth more than five. The fact that the mother had a regular vegetable diet everyday reduced the mercury levels. Increased levels of mercury in the mother and umbilical cord blood could lead to retarded newborns' weight and height. Conclusion: Pregnant women living in Istanbul may be not under the risk of chronic mercury intoxication. Fish consumption more than twice per week and tooth-filling of mother more than five may increase mercury level. On the contrary, regular diet rich in vegetable decreases the mercury level

Correlation between arterial and venous blood gas analysis parameters in patients with acute exacerbation of chronic obstructive pulmonary disease

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Novović Miloš

2012-01-01

Full Text Available Introduction. Arterial blood gas (ABG analyses have an important role in the assessment and monitoring of the metabolic and oxygen status of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD. Arterial puncture could have a lot of adverse effects, while sampling of venous blood is simpler and is not so invasive. Objective. The aim of this study was to evaluate whether venous blood gas (VBG values of pH, partial pressure of carbon dioxide (PCO2, partial oxygen pressure (PO2, bicarbonate (HCO3, and venous and arterial blood oxygen saturation (SO2 can reliably predict ABG levels in patients with acute exacerbation of COPD. Methods. Forty-seven patients with a prior diagnosis of COPD were included in this prospective study. The patients with acute exacerbation of this disease were examined at the General Hospital EMS Department in Prijepolje. ABG samples were taken immediately after venous sampling, and both were analyzed. Results. The Pearson correlation coefficients between arterial and venous parameters were 0.828, 0.877, 0.599, 0.896 and 0.312 for pH, PCO2, PO2, HCO3 and SO2, respectively. The statistically significant correlation between arterial and venous pH, PCO2 and HCO3, values was found in patients with acute exacerbation of COPD (p<0.001. Conclusion. When we cannot provide arterial blood for analysis, venous values of the pH, Pv,CO2 and HCO3 parameters can be an alternative to their arterial equivalents in the interpretation of the metabolic status in patients with acute exacerbation of COPD, while the values of venous Pv,O2 and Sv,O2 cannot be used as predictors in the assessment of oxygen status of such patients.

The effect of resting blood flow occlusion on exercise tolerance and W'.

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Broxterman, Ryan M; Craig, Jesse C; Ade, Carl J; Wilcox, Samuel L; Barstow, Thomas J

2015-09-15

It has previously been postulated that the anaerobic work capacity (W') may be utilized during resting blood flow occlusion in the absence of mechanical work. We tested the hypothesis that W' would not be utilized during an initial range of time following the onset of resting blood flow occlusion, after which W' would be utilized progressively more. Seven men completed blood flow occlusion constant power severe intensity handgrip exercise to task failure following 0, 300, 600, 900, and 1,200 s of resting blood flow occlusion. The work performed above critical power (CP) was not significantly different between the 0-, 300-, and 600-s conditions and was not significantly different from the total W' available. Significantly less work was performed above CP during the 1,200-s condition than the 900-s condition (P W' available (P W' during resting blood flow occlusion did not begin until 751 ± 118 s, after which time W' was progressively utilized. The current findings demonstrate that W' is not utilized during the initial ∼751 s of resting blood flow occlusion, but is progressively utilized thereafter, despite no mechanical work being performed. Thus, the utilization of W' is not exclusive to exercise, and a constant amount of work that can be performed above CP is not the determining mechanism of W'. Copyright © 2015 the American Physiological Society.

The influence of venous blood flow on the retinal ganglion cell complex in patients with primary open angle glaucoma

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N. I. Kurysheva

2014-07-01

Full Text Available Purpose: To study the influence of venous blood flow on the ganglion cell complex (GCC in patients with preperimetric and perimetric open angle glaucoma.Methods: 74 patients were included in the research. 59 eyes and 62 eyes were diagnosed with preperimetric and perimetric open angle glaucoma respectively. The mean age was 56.5±10.5 years. 22 (12 female and 10 male healthy individuals constituted the control group. The ganglion cell complex and retinal nerve fibre layer were evaluated with the help of optical coherence tomography (RTVue-100 OCT, Optovue, Inc., Fremont, CA. Ocular blood flow was measured by Color Doppler Imaging (multifunctional VOLUSON 730 ProSystem. The statistical analysis included correlation between GCC and RNFL thickness in both glaucoma groups.Results: The results showed a statistically significant reduction of venous blood flow velocity in both glaucoma groups compared to the control group. No difference in venous blood flow parameters between two glaucoma groups was found, except resistance index, which was higher in perimetric group in comparison to preperimetric group. A correlation was also obtained between venous blood flow parameters and GCC and RNFL thickness in both glaucoma groups.Conclusion: Early GCC damage in glaucoma might occur due to venous blood flow reduction. This fact may be of great value in understanding glaucoma pathogenesis and search for novel treatment options.

Effect of prewarming the forearm on the measurement of regional cerebral blood flow with one-point venous sampling by autoradiography method

International Nuclear Information System (INIS)

Itoh, Youko H.; Kurabe, Teruhisa; Kazaoka, Yoshiaki; Ishiguchi, Tsuneo; Kawashima, Sadao

2004-01-01

Autoradiography (ARG) using 123 I-iodoamphetamine ( 123 I-IMP) is widely performed as an efficient method of measuring local cerebral blood flow. Recently, ARG by a single collection of venous blood has been appreciated as a simple method. In this study, we investigated the effect of warming of the site for collecting venous blood (forearm). The coefficient of correlation of the local cerebral blood flow value obtained from arterial and venous blood samples was 0.766 (p<0.05) in the group without warming (38 patients). The coefficient of correlation similarly obtained in the group with warming (53 patients) was 0.908 (p<0.05). The difference in the correlation efficient was significant (p<0.05) between the two groups. From these results it was concluded that warming the blood-collecting site decreased the difference between the arterial and venous radioactive concentrations and increased the precision of the test. (author)

Peripheral venous distension elicits a blood pressure raising reflex in young and middle-aged adults.

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Matthews, Evan L; Brian, Michael S; Coyle, Dana E; Edwards, David G; Stocker, Sean D; Wenner, Megan M; Farquhar, William B

2016-06-01

Distension of peripheral veins in humans elicits a pressor and sympathoexcitatory response that is mediated through group III/IV skeletal muscle afferents. There is some evidence that autonomic reflexes mediated by these sensory fibers are blunted with increasing age, yet to date the venous distension reflex has only been studied in young adults. Therefore, we tested the hypothesis that the venous distension reflex would be attenuated in middle-aged compared with young adults. Nineteen young (14 men/5 women, 25 ± 1 yr) and 13 middle-aged (9 men/4 women, 50 ± 2 yr) healthy normotensive participants underwent venous distension via saline infusion through a retrograde intravenous catheter in an antecubital vein during limb occlusion. Beat-by-beat blood pressure, muscle sympathetic nerve activity (MSNA), and model flow-derived cardiac output (Q), and total peripheral resistance (TPR) were recorded throughout the trial. Mean arterial pressure (MAP) increased during the venous distension in both young (baseline 83 ± 2, peak 94 ± 3 mmHg; P blood pressure, MSNA, and TPR were similar between young and middle-aged adults. Additionally, no correlation was found between age and the response to venous distension (all P > 0.05). These findings suggest that peripheral venous distension elicits a pressor and sympathetic response in middle-aged adults similar to the response observed in young adults. Copyright © 2016 the American Physiological Society.

Effect of PEEP, blood volume, and inspiratory hold maneuvers on venous return.

Science.gov (United States)

Berger, David; Moller, Per W; Weber, Alberto; Bloch, Andreas; Bloechlinger, Stefan; Haenggi, Matthias; Sondergaard, Soren; Jakob, Stephan M; Magder, Sheldon; Takala, Jukka

2016-09-01

According to Guyton's model of circulation, mean systemic filling pressure (MSFP), right atrial pressure (RAP), and resistance to venous return (RVR) determine venous return. MSFP has been estimated from inspiratory hold-induced changes in RAP and blood flow. We studied the effect of positive end-expiratory pressure (PEEP) and blood volume on venous return and MSFP in pigs. MSFP was measured by balloon occlusion of the right atrium (MSFPRAO), and the MSFP obtained via extrapolation of pressure-flow relationships with airway occlusion (MSFPinsp_hold) was extrapolated from RAP/pulmonary artery flow (QPA) relationships during inspiratory holds at PEEP 5 and 10 cmH2O, after bleeding, and in hypervolemia. MSFPRAO increased with PEEP [PEEP 5, 12.9 (SD 2.5) mmHg; PEEP 10, 14.0 (SD 2.6) mmHg, P = 0.002] without change in QPA [2.75 (SD 0.43) vs. 2.56 (SD 0.45) l/min, P = 0.094]. MSFPRAO decreased after bleeding and increased in hypervolemia [10.8 (SD 2.2) and 16.4 (SD 3.0) mmHg, respectively, P waterfall. Copyright © 2016 the American Physiological Society.

Evaluation of factor for one-point venous blood sampling method based on the causality model

International Nuclear Information System (INIS)

Matsutomo, Norikazu; Onishi, Hideo; Kobara, Kouichi; Sasaki, Fumie; Watanabe, Haruo; Nagaki, Akio; Mimura, Hiroaki

2009-01-01

One-point venous blood sampling method (Mimura, et al.) can evaluate the regional cerebral blood flow (rCBF) value with a high degree of accuracy. However, the method is accompanied by complexity of technique because it requires a venous blood Octanol value, and its accuracy is affected by factors of input function. Therefore, we evaluated the factors that are used for input function to determine the accuracy input function and simplify the technique. The input function which uses the time-dependent brain count of 5 minutes, 15 minutes, and 25 minutes from administration, and the input function in which an objective variable is used as the artery octanol value to exclude the venous blood octanol value are created. Therefore, a correlation between these functions and rCBF value by the microsphere (MS) method is evaluated. Creation of a high-accuracy input function and simplification of technique are possible. The rCBF value obtained by the input function, the factor of which is a time-dependent brain count of 5 minutes from administration, and the objective variable is artery octanol value, had a high correlation with the MS method (y=0.899x+4.653, r=0.842). (author)

Perceived unfairness at work, social and personal resources, and resting blood pressure.

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Ford, Michael T

2014-02-01

By drawing from theoretical perspectives suggesting that unfair conditions threaten fundamental psychological needs, perceived unfairness at work was proposed and tested as a predictor of resting blood pressure. As part of the Midlife Development in the United States Biomarkers project, participants completed questionnaires measuring perceived unfairness, self-esteem and coworker support. Resting blood pressure readings were also recorded as part of a larger physical examination. Results indicate that perceived unfairness at work was associated with higher resting diastolic and systolic blood pressure. Perceived unfairness was most strongly related to diastolic and systolic blood pressure among women with low levels of coworker support. Contrary to predictions, self-esteem did not moderate the association between perceived unfairness and blood pressure. These results suggest that high blood pressure may be a mechanism linking unfairness to negative health outcomes and point to coworker support as a moderator of the perceived unfairness-blood pressure relationship among women. Further research is needed exploring the mediating mechanisms linking unfair treatment at work to blood pressure and health. Copyright © 2013 John Wiley & Sons, Ltd.

Comparison of oxidative/antioxidative status of penile corpus cavernosum blood and peripheral venous blood.

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Yeni, E; Gulum, M; Selek, S; Erel, O; Unal, D; Verit, A; Savas, M

2005-01-01

The aim of the study is to determine and to compare the oxidative and antioxidative status of penile corpus cavernosum and peripheral venous blood. A total of 28 adult healthy males were included in the study. Whole blood was simultaneously withdrawn from penile corpus cavernosum and the cubital vein and their plasma separated. Total antioxidant capacity (TAC), vitamin C, total protein, albumin, uric acid, bilirubin and total peroxide (TP) levels of both plasma samples were measured and compared. While TAC, total protein, albumin, bilirubin and uric acid levels were higher, vitamin C levels were lower in cavernosal blood than that of peripheral blood. On the other hand, TP level was found to be higher in penile blood samples than that of peripheral blood. We thought that the normal erectile process of the penile cavernosal body leads to increased production of oxidants as in the mechanism of ischaemia-reperfusion; however, the increase of TAC can prevent development of oxidative injury.

Blood flow in exercising muscles by xenon clearance and by microsphere trapping

International Nuclear Information System (INIS)

Cerretelli, P.; Marconi, C.; Pendergast, D.; Meyer, M.; Heisler, N.; Piiper, J.

1984-01-01

The accuracy of muscle blood flow measurement by the 133 Xe clearance method (Qxe) was assessed against direct venous outflow (Qv) and microsphere trapping flow (Qμ) determinations in isolated perfused dog gastrocnemius both at rest and during graded stimulation [O 2 consumption (Vo 2 ) up to 12 ml x 100 g -1 x min -1 ] and in the gastrocnemius, vastus lateralis, and triceps of intact dogs at rest and while running on a treadmill at varied speeds up to maximum Vo 2 . In 29 measurements performed in 11 isolated muscles, Qμ was in good agreement with Qv at rest and at all stimulation levels (Qμ/Qv = 1.0 r = 0.98). 133 Xe clearance yielded much lower blood flows than the venous outflow and the microsphere trapping methods. In 43 measurements in 11 muscles, the mean Qxe/Qv ratio was 0.57 +/- 0.03 (SE), independent of blood flow. Similarly, in 65 measurements in 2 intact dogs, the mean Qxe/Qμ ratio in all tested muscles was 0.49 +/- 0.02 (SE), independent of blood flow. These results show that the 133 Xe clearance method considerably underestimates blood flow in dog muscles

How does the blood leave the brain? A systematic ultrasound analysis of cerebral venous drainage patterns

International Nuclear Information System (INIS)

Doepp, Florian; Schreiber, Stephan J.; Muenster, Thomas von; Rademacher, Joerg; Valdueza, Jose M.; Klingebiel, Randolf

2004-01-01

The internal jugular veins are considered to be the main pathways of cerebral blood drainage. However, angiographic and anatomical studies show a wide anatomical variability and varying degrees of jugular and non-jugular venous drainage. The study systematically analyses the types and prevalence of human cerebral venous outflow patterns by ultrasound and MRI. Fifty healthy volunteers (21 females; 29 males; mean age 27±7 years) were studied by color-coded duplex sonography. Venous blood volume flow was measured in both internal jugular and vertebral veins in the supine position. Furthermore, the global arterial cerebral blood volume flow was calculated as the sum of volume flows in both internal carotid and vertebral arteries. Three types of venous drainage patterns were defined: a total jugular volume flow of more than 2/3 (type 1), between 1/3 and 2/3 (type 2) and less than 1/3 (type 3) of the global arterial blood flow. 2D TOF MR-venography was performed exemplarily in one subject with type-1 and in two subjects with type-3 drainage. Type-1 drainage was present in 36 subjects (72%), type 2 in 11 subjects (22%) and type 3 in 3 subjects (6%). In the majority of subjects in our study population, the internal jugular veins were indeed the main drainage vessels in the supine body position. However, a predominantly non-jugular drainage pattern was found in approximately 6% of subjects. (orig.)

Venous pump of the calf: a study of venous and muscular pressures.

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Alimi, Y S; Barthelemy, P; Juhan, C

1994-11-01

Little data are available concerning the relation between the muscular pumping mechanism and the variation of superficial and deep venous pressure during normal action of the calf pump; therefore we undertook this study to determine the pressure values in three compartments of the calf and in the deep and the superficial venous system and to establish correlation between muscular and venous pressure. Nine healthy young women with a mean age of 23 years (range 19 to 28 years) were examined. In the same calf, a muscular catheter was placed in the deep posterior compartment (DPC), in the superficial posterior compartment (SPC), and in the anterior tibial compartment (ATC), and a vascular catheter was placed in the popliteal vein and in the greater saphenous vein (GSV). The five lines of pressure were simultaneously recorded in the following situations: at rest, during Valsalva maneuver, foot flexion, and foot extension. The situation was studied with the patient in the following positions: decubitus, sitting, standing, and squatting. A final continuous recording was carried out after the patient had been walking for 5 minutes. Mean values with standard errors of muscular and venous pressure were established in each situation. At rest and during Valsalva maneuver, the muscular pressures did not vary, whereas venous pressures increased significantly when the patient was sitting and standing. On the other hand, squatting was associated with a rise in the muscular and vein pressures. Foot flexion entailed a significant increase in the ATC pressure and a rise in the GSV pressure, whereas foot extension caused the DPC pressure to rise without venous pressure modifications. Walking was associated with an alternating increase in the DPC, SPC, GSV and popliteal vein pressures when the foot was compressed to floor followed by a significant decrease when the foot pressure was released. The variations in the deep and superficial venous pressures when the patient is sitting and

Clinicopathologic analysis of Passeriform venous blood reflects transitions in elevation and habitat

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Heatley JJ

2013-06-01

Full Text Available J Jill Heatley,1 Jennifer Cary,2 Karen E Russell,3 Gary Voelker2 1Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, 2Department of Wildlife and Fisheries Sciences and Texas A&M Biodiversity Research and Teaching Collections, Texas A&M University, 3Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, College Station, TX, USA Abstract: Jugular blood samples from 110 Passeriformes collected at several Texas locations were analyzed for multiple clinicopathologic parameters between April 2010 and August 2011. Electrolyte, blood gas, and select erythrocyte parameters were analyzed on site with a point of care analyzer, and gender, age, body condition score, location, and species were recorded. Many analytes exhibited a Gaussian distribution across species and are reported as a single range. Taxon affected electrolyte and red blood cell parameters, but not most blood gas or acid base variables. Migratory status affected select electrolytes but few blood gas variables. Red blood cell parameters were affected the most by variables of age, taxonomic group, and gender, but not migratory life history. We found significant changes in glucose and numerous acid base analytes in birds sampled from habitats with evolutionarily recent ecologic degradation. We advocate the use of these analytes, particularly venous blood gas values, as determined by a point of care analyzer, as reasonable biomarkers for determination of Passeriform population health, but also recommend that red blood cell parameters and electrolyte concentrations be controlled for age, species, and gender in future studies. Further, based on our investigation, venous blood gas values and acid base balance in Passeriformes can assess the health of an ecosystem. Keywords: avian, biochemistry, blood gas, electrolyte, hematology, Passerine

Capillary versus Venous Hemoglobin Determination in the Assessment of Healthy Blood Donors

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Patel, Abhilasha J.; Wesley, Robert; Leitman, Susan F.; Bryant, Barbara J.

2013-01-01

Background and Objectives To determine the accuracy of fingerstick hemoglobin assessment in blood donors, the performance of a portable hemoglobinometer (HemoCue Hb 201+) was prospectively compared with that of an automated hematology analyzer (Cell-Dyn 4000). Hemoglobin values obtained by the latter were used as the “true” result. Material and Methods Capillary fingerstick samples were assayed by HemoCue in 150 donors. Fingerstick samples from two sites, one on each hand, were obtained from a subset of 50 subjects. Concurrent venous samples were tested using both HemoCue and Cell-Dyn devices. Results Capillary hemoglobin values (HemoCue) were significantly greater than venous hemoglobin values (HemoCue), which in turn were significantly greater than venous hemoglobin values by Cell-Dyn (mean ± SD: 14.05 ± 1.51, 13.89 ± 1.31, 13.62 ± 1.23, respectively; phemoglobin screening criteria (≥12.5 g/dL) by capillary HemoCue, but were deferred by Cell-Dyn values (false-pass). Five donors (3%) were deferred by capillary sampling, but passed by Cell-Dyn (false-fail). Substantial variability in repeated fingerstick HemoCue results was seen (mean hemoglobin 13.72 vs. 13.70 g/dL, absolute mean difference between paired samples 0.76 g/dL). Hand dominance was not a factor. Conclusions Capillary samples assessed via a portable device yielded higher hemoglobin values than venous samples assessed on an automated analyzer. False-pass and false-fail rates were low and acceptable in the donor screening setting, with “true” values not differing by a clinically significant degree from threshold values used to assess acceptability for blood donation. PMID:23294266

A comparison of capillary and venous blood haematocrits of pregnant women in Nigeria: the impact on diagnosis and prevalence of anaemia in pregnancy.

Science.gov (United States)

Dim, Cyril Chukwudi; Ugwu, Emmanuel Onyebuchi; Anyaehie, Ugochukwu Bond; Obioha, Kingsley Chukwu

2014-01-01

Volume of red cells in capillary blood varies from that of venous blood. The magnitude of this variation as well as its impact on the diagnosis of anaemia in pregnancy needs to be studied. This study demonstrates the disparity between capillary and venous PCV in pregnancy. To determine whether capillary blood PCV (cPCV) differed from venous blood PCV (vPCV) of normal pregnant women in Enugu, Nigeria, and its effect on diagnosis and prevalence of anaemia. PCV was estimated using pairs of venous and capillary blood samples from 200 consecutive pregnant women at the Antenatal Clinic of University of Nigeria Teaching Hospital, Enugu, Nigeria. Participants' cPCV (median = 34.0%, IQR = 31.0-35.8) was significantly lower than their vPCV (median = 34.0%, IQR = 32.0-37.0) (Z = -6.85, P prevalence of anaemia among participants using capillary and venous blood was 33.5% (67/200) and 28.0% (56/200), respectively (O.R = 1.3 (CI 95%: 0.85, 1.98),  P = 0.233). Capillary blood PCV was lower than vPCV among pregnant women in Enugu, Nigeria. Nevertheless, the prevalence of anaemia derived from cPCV did not differ significantly from that of vPCV.

Measurement of regional cerebral blood flow using one-point venous blood sampling and causality model. Evaluation by comparing with conventional continuous arterial blood sampling method

International Nuclear Information System (INIS)

Mimura, Hiroaki; Sone, Teruki; Takahashi, Yoshitake

2008-01-01

Optimal setting of the input function is essential for the measurement of regional cerebral blood flow (rCBF) based on the microsphere model using N-isopropyl-4-[ 123 I]iodoamphetamine ( 123 I-IMP), and usually the arterial 123 I-IMP concentration (integral value) in the initial 5 min is used for this purpose. We have developed a new convenient method in which 123 I-IMP concentration in arterial blood sample is estimated from that in venous blood sample. Brain perfusion single photon emission computed tomography (SPECT) with 123 I-IMP was performed in 110 cases of central nervous system disorders. The causality was analyzed between the various parameters of SPECT data and the ratio of octanol-extracted arterial radioactivity concentration during the first 5 min (Caoct) to octanol-extracted venous radioactivity concentration at 27 min after intravenous injection of 123 I-IMP (Cvoct). A high correlation was observed between the measured and estimated values of Caoct/Cvoct (r=0.856) when the following five parameters were included in the regression formula: radioactivity concentration in venous blood sampled at 27 min (Cv), Cvoct, Cvoct/Cv, and total brain radioactivity counts that were measured by a four-head gamma camera 5 min and 28 min after 123 I-IMP injection. Furthermore, the rCBF values obtained using the input parameters estimated by this method were also highly correlated with the rCBF values measured using the continuous arterial blood sampling method (r=0.912). These results suggest that this method would serve as the new, convenient and less invasive method of rCBF measurement in clinical setting. (author)

Serial blood pressure measurements

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N.R. Koehler

2002-05-01

Full Text Available The objective of the present investigation was to study the effects of a 60-s interval of venous congestion between two noninvasive measurements of arterial blood pressure (ABP on the fluctuation of ABP, assessed by the standard deviation of the differences between two readings. ABP was measured in 345 successive patients, at rest, four times each. For 269 participants, one pair of readings was obtained with a 60-s interval and the other pair without an interval. For 76 patients, the first pair was read at the same interval, and the second pair had venous congestion interposed and there was no waiting interval. There was no increased ABP oscillation, either when there was no interval between ABP readings, or when venous congestion was interposed compared to pairs of ABP measurements performed with a 60-s interval. There was no increase in ABP oscillations when successive ABP readings were taken without an interval or even with venous congestion interposed. Contrary to the present belief, there seems to be no loss of reliability when blood pressure recordings are taken immediately one after another, in the clinical setting.

Effects of aging on blood pressure variability in resting conditions

NARCIS (Netherlands)

Veerman, D. P.; Imholz, B. P.; Wieling, W.; Karemaker, J. M.; van Montfrans, G. A.

1994-01-01

The objective of this study was to determine the effect of aging on beat-to-beat blood pressure and pulse interval variability in resting conditions and to determine the effect of aging on the sympathetic and vagal influence on the cardiovascular system by power spectral analysis of blood pressure

Blood pressure normalization post-jugular venous balloon angioplasty.

Science.gov (United States)

Sternberg, Zohara; Grewal, Prabhjot; Cen, Steven; DeBarge-Igoe, Frances; Yu, Jinhee; Arata, Michael

2015-05-01

This study is the first in a series investigating the relationship between autonomic nervous system dysfunction and chronic cerebrospinal venous insufficiency in multiple sclerosis patients. We screened patients for the combined presence of the narrowing of the internal jugular veins and symptoms of autonomic nervous system dysfunction (fatigue, cognitive dysfunction, sleeping disorders, headache, thermal intolerance, bowel/bladder dysfunction) and determined systolic and diastolic blood pressure responses to balloon angioplasty. The criteria for eligibility for balloon angioplasty intervention included ≥ 50% narrowing in one or both internal jugular veins, as determined by the magnetic resonance venography, and ≥ 3 clinical symptoms of autonomic nervous system dysfunction. Blood pressure was measured at baseline and post-balloon angioplasty. Among patients who were screened, 91% were identified as having internal jugular veins narrowing (with obstructing lesions) combined with the presence of three or more symptoms of autonomic nervous system dysfunction. Balloon angioplasty reduced the average systolic and diastolic blood pressure. However, blood pressure categorization showed a biphasic response to balloon angioplasty. The procedure increased blood pressure in multiple sclerosis patients who presented with baseline blood pressure within lower limits of normal ranges (systolic ≤ 105 mmHg, diastolic ≤ 70 mmHg) but decreased blood pressure in patients with baseline blood pressure above normal ranges (systolic ≥ 130 mmHg, diastolic ≥ 80 mmHg). In addition, gender differences in baseline blood pressure subcategories were observed. The coexistence of internal jugular veins narrowing and symptoms of autonomic nervous system dysfunction suggests that the two phenomena may be related. Balloon angioplasty corrects blood pressure deviation in multiple sclerosis patients undergoing internal jugular vein dilation. Further studies should investigate the

Reliable rapid blood test for the exclusion of venous thromboembolism in symptomatic outpatients

NARCIS (Netherlands)

Turkstra, F.; van Beek, E. J.; ten Cate, J. W.; Büller, H. R.

1996-01-01

In this study we assessed the reliability of a rapid bed-side whole blood D-dimer assay prospectively in patients with clinically suspected venous thromboembolism, referred to the Academic Medical Centre, Amsterdam. In consecutive outpatients with clinically suspected deep vein thrombosis or

Combination of phlebography and sanguinous measurement of venous blood pressure

International Nuclear Information System (INIS)

Weber, J.

1988-01-01

Phlebographic visualisation offers the highest spatial resolution of all imaging methods both in respect of veins of the leg and pelvis and of the abdomen. Phlebography offers optimal conditions for assessing morphological changes at the veins and in their direct neighbourhood. No quantitative information is available via phlebography if haemodynamics are disturbed; qualitative information is yielded merely to a restricted extent (by assessing flow velocity and collaterals). Direct sanguinous measurement of venous blood pressure is particularly suitable for the quantitative and qualitative assessment of disturbed haemodynamic conditions; in this respect it stands out among the function tests based on the employment of apparatures. If it is combined with phlebography, it is possible not only to optimise the diagnostic yield in the hands of one investigator, but also to reduce the invasiveness of both methods to one single puncture, since the puncture needle is at the same time also an instrument to measure the pressure. The article points out the possibilities and limitations of combining a) ascending phlebography of the leg and pelvis with peripheral venous pressure measurement (phlebodynamometry) and b) visualisation of the veins of the pelvis and vena cava inferior with central sanguinous venous pressure measurement (CP). Indicatious and technical execution are described. (orig.) [de

LETTER TO THE EDITOR: Arterio-venous flow between monochorionic twins determined during intra-uterine transfusion. Nonlinear decay of adult red blood cells

Science.gov (United States)

van Gemert, Martin J. C.; Pasman, Suzanne A.; van den Wijngaard, Jeroen P. H. M.; Lopriore, Enrico; Vandenbussche, Frank P. H. A.

2008-07-01

Recently, we derived equations relating the flow of adult red blood cells through a placental arterio-venous anastomosis with intra-uterine and post-natal measured adult hemoglobin concentrations. In this letter, we re-derived the equations, now including a more realistic nonlinear decay of adult red blood cells, and re-evaluated the measurement accuracy of the arterio-venous flow and the lifetime of the red blood cells.

Effect of furosemide on pulmonary blood flow distribution in resting and exercising horses

Science.gov (United States)

Erickson, H. H.; Bernard, S. L.; Glenny, R. W.; Fedde, M. R.; Polissar, N. L.; Basaraba, R. J.; Walther, S. M.; Gaughan, E. M.; McMurphy, R.; Hlastala, M. P.

1999-01-01

We determined the spatial distribution of pulmonary blood flow (PBF) with 15-micron fluorescent-labeled microspheres during rest and exercise in five Thoroughbred horses before and 4 h after furosemide administration (0.5 mg/kg iv). The primary finding of this study was that PBF redistribution occurred from rest to exercise, both with and without furosemide. However, there was less blood flow to the dorsal portion of the lung during exercise postfurosemide compared with prefurosemide. Furosemide did alter the resting perfusion distribution by increasing the flow to the ventral regions of the lung; however, that increase in flow was abated with exercise. Other findings included 1) unchanged gas exchange and cardiac output during rest and exercise after vs. before furosemide, 2) a decrease in pulmonary arterial pressure after furosemide, 3) an increase in the slope of the relationship of PBF vs. vertical height up the lung during exercise, both with and without furosemide, and 4) a decrease in blood flow to the dorsal region of the lung at rest after furosemide. Pulmonary perfusion variability within the lung may be a function of the anatomy of the pulmonary vessels that results in a predominantly fixed spatial pattern of flow distribution.

A Comparison of Capillary and Venous Blood Haematocrits of Pregnant Women in Nigeria: The Impact on Diagnosis and Prevalence of Anaemia in Pregnancy

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Cyril Chukwudi Dim

2014-01-01

Full Text Available Background. Volume of red cells in capillary blood varies from that of venous blood. The magnitude of this variation as well as its impact on the diagnosis of anaemia in pregnancy needs to be studied. This study demonstrates the disparity between capillary and venous PCV in pregnancy. Objectives. To determine whether capillary blood PCV (cPCV differed from venous blood PCV (vPCV of normal pregnant women in Enugu, Nigeria, and its effect on diagnosis and prevalence of anaemia. Methods. PCV was estimated using pairs of venous and capillary blood samples from 200 consecutive pregnant women at the Antenatal Clinic of University of Nigeria Teaching Hospital, Enugu, Nigeria. Results. Participants’ cPCV (median=34.0%, IQR=31.0–35.8 was significantly lower than their vPCV (median=34.0%, IQR=32.0–37.0 (Z=-6.85, P<0.001. However, women’s cPCV had strong positive correlation with their vPCV (r=0.883, P<0.001. The prevalence of anaemia among participants using capillary and venous blood was 33.5% (67/200 and 28.0% (56/200, respectively (O.R=1.3 (CI 95%: 0.85, 1.98,  P=0.233. Conclusions. Capillary blood PCV was lower than vPCV among pregnant women in Enugu, Nigeria. Nevertheless, the prevalence of anaemia derived from cPCV did not differ significantly from that of vPCV.

Blood flow vs. venous pressure effects on filtration coefficient in oleic acid-injured lung.

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Anglade, D; Corboz, M; Menaouar, A; Parker, J C; Sanou, S; Bayat, S; Benchetrit, G; Grimbert, F A

1998-03-01

On the basis of changes in capillary filtration coefficient (Kfc) in 24 rabbit lungs, we determined whether elevations in pulmonary venous pressure (Ppv) or blood flow (BF) produced differences in filtration surface area in oleic acid-injured (OA) or control (Con) lungs. Lungs were cyclically ventilated and perfused under zone 3 conditions by using blood and 5% albumin with no pharmacological modulation of vascular tone. Pulmonary arterial, venous, and capillary pressures were measured by using arterial, venous, and double occlusion. Before and during each Kfc-measurement maneuver, microvascular/total vascular compliance was measured by using venous occlusion. Kfc was measured before and 30 min after injury, by using a Ppv elevation of 7 cmH2O or a BF elevation from 1 to 2 l . min-1 . 100 g-1 to obtain a similar double occlusion pressure. Pulmonary arterial pressure increased more with BF than with Ppv in both Con and OA lungs [29 +/- 2 vs. 19 +/- 0.7 (means +/- SE) cmH2O; P Kfc (200 +/- 40 vs. 83 +/- 14%, respectively; P < 0.01) and microvascular/total vascular compliance ratio (86 +/- 4 vs. 68 +/- 5%, respectively; P < 0.01) increased more with BF than with Ppv. In conclusion, for a given OA-induced increase in hydraulic conductivity, BF elevation increased filtration surface area more than did Ppv elevation. The steep pulmonary pressure profile induced by increased BF could result in the recruitment of injured capillaries and could also shift downstream the compression point of blind (zone 1) and open injured vessels (zone 2).

Cardiorespiratory effects of venous lipid micro embolization in an experimental model of mediastinal shed blood reinfusion

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Dencker Magnus

2009-09-01

Full Text Available Abstract Background Retransfusion of the patient's own blood during surgery is used to reduce the need for allogenic blood transfusion. It has however been found that this blood contains lipid particles, which form emboli in different organs if the blood is retransfused on the arterial side. In this study, we tested whether retransfusion of blood containing lipid micro-particles on the venous side in a porcine model will give hemodynamic effects. Methods Seven adult pigs were used. A shed blood surrogate containing 400 ml diluted blood and 5 ml radioactive triolein was produced to generate a lipid embolic load. The shed blood surrogate was rapidly ( Results A more than 30-fold increase in pulmonary vascular resistance was observed, with subsequent increase in pulmonary artery pressure, and decrease in cardiac output and arterial pressure. This response was transient, but was followed by a smaller, persistent increase in pulmonary vascular resistance. Only a small portion of the infused triolein passed the lungs, and only a small fraction could be recirculated by increasing cardiac output and pulmonary pressure. Conclusion Infusion of blood containing lipid micro-emboli on the venous side leads to acute, severe hemodynamic responses that can be life threatening. Lipid particles will be trapped in the lungs, leading to persistent effects on the pulmonary vascular resistance.

Standardised Resting Time Prior to Blood Sampling and Diurnal Variation Associated with Risk of Patient Misclassification

DEFF Research Database (Denmark)

Bøgh Andersen, Ida; Brasen, Claus L.; Christensen, Henry

2015-01-01

.9×10-7) and sodium (p = 8.7×10-16). Only TSH and albumin were clinically significantly influenced by diurnal variation. Resting time had no clinically significant effect. CONCLUSIONS: We found no need for resting 15 minutes prior to blood sampling. However, diurnal variation was found to have a significant......BACKGROUND: According to current recommendations, blood samples should be taken in the morning after 15 minutes' resting time. Some components exhibit diurnal variation and in response to pressures to expand opening hours and reduce waiting time, the aims of this study were to investigate...... the impact of resting time prior to blood sampling and diurnal variation on biochemical components, including albumin, thyrotropin (TSH), total calcium and sodium in plasma. METHODS: All patients referred to an outpatient clinic for blood sampling were included in the period Nov 2011 until June 2014 (opening...

Radioimmunological determination of 5a-pregnane-3,20-dione and progesterone in arterial and venous blood from the umbilical cord

International Nuclear Information System (INIS)

Tannich, E.

1985-01-01

Radioimmunological investigations of arterial and venous blood from the umbilical cord for 5a-DHP and progesterone were carried out in 60 newly delivered infants using 3 H as a tracer substance. The following findings were revealed: 1) The correlation between progesterone and 5a-DHP was better in the venous blood than in the arterial blood from the umbilical cord and the concentrations measured for the two hormones were higher in the vein. 2) Both the umbilical vein and artery showed more elevated hormone levels in male infants as compared to female infants. 3) The duration of gestation, the concentration of hydrogen ions in the fetal plasma and various other maternal and fetal factors have an influence on the height of the 5a-DHP and progesterone levels in the umbilical blood. This was also concluded from the fact that the (arterial and venous) hormone concentrations measured in infants from primiparae were higher than those in infants from multiparae. The metabolisation of 5a-DHP varies between the sexes, which does not hold true for progosterone. (TRV) [de

Single pyruvate intake induces blood alkalization and modification of resting metabolism in humans.

Science.gov (United States)

Olek, Robert A; Luszczyk, Marcin; Kujach, Sylwester; Ziemann, Ewa; Pieszko, Magdalena; Pischel, Ivo; Laskowski, Radoslaw

2015-03-01

Three separate studies were performed with the aim to 1) determine the effect of a single sodium pyruvate intake on the blood acid-base status in males and females; 2) compare the effect of sodium and calcium pyruvate salts and establish their role in the lipolysis rate; and 3) quantify the effect of single pyruvate intake on the resting energy metabolism. In all, 48 individuals completed three separate studies. In all the studies, participants consumed a single dose of pyruvate 0.1 g/kg 60 min before commencing the measurements. The whole blood pH, bicarbonate concentration, base excess or plasma glycerol, free fatty acids, glucose concentrations, or resting energy expenditure and calculated respiratory exchange ratio were determined. The analysis of variance for repeated measurements was performed to examine the interaction between treatment and time. The single dose of sodium pyruvate induced blood alkalization, which was more marked in the male than in the female participants. Following the ingestion of sodium or calcium pyruvate, the blood acid-base parameters were higher than in the placebo trial. Furthermore, 3-h postingestion glycerol was lower in both pyruvate trials than in placebo. Resting energy expenditure did not differ between the trials; however, carbohydrate oxidation was increased after sodium pyruvate ingestion. Pyruvate intake induced mild alkalization in a sex-dependent fashion. Moreover, it accelerated carbohydrate metabolism and delayed the rate of glycerol appearance in the blood, but had no effect on the resting energy expenditure. Furthermore, sodium salt seems to have had a greater effect on the blood buffering level than calcium salt. Copyright © 2015 Elsevier Inc. All rights reserved.

A Computational Study on the Relation between Resting Heart Rate and Atrial Fibrillation Hemodynamics under Exercise.

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Matteo Anselmino

Full Text Available Clinical data indicating a heart rate (HR target during rate control therapy for permanent atrial fibrillation (AF and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model.The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task-MET and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running, considering different resting HR (70 bpm for the slower resting HR-SHR-simulations, and 100 bpm for the higher resting HR-HHR-simulations. To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI-the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations-was calculated at each exercise grade (VCI4, VCI6 and VCI8.Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77, while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56.The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase.

A Computational Study on the Relation between Resting Heart Rate and Atrial Fibrillation Hemodynamics under Exercise.

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Anselmino, Matteo; Scarsoglio, Stefania; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca

2017-01-01

Clinical data indicating a heart rate (HR) target during rate control therapy for permanent atrial fibrillation (AF) and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model. The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task-MET) and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running), considering different resting HR (70 bpm for the slower resting HR-SHR-simulations, and 100 bpm for the higher resting HR-HHR-simulations). To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI)-the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations-was calculated at each exercise grade (VCI4, VCI6 and VCI8). Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77), while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56). The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase.

rCBF measurement by one-point venous sampling with the ARG method

International Nuclear Information System (INIS)

Yoshida, Nobuhiro; Okamoto, Toshiaki; Takahashi, Hidekado; Hattori, Teruo

1997-01-01

We investigated the possibility of using venous blood sampling instead of arterial blood sampling for the current method of ARG (autoradiography) used to determine regional cerebral blood flow (rCBF) on the basis of one session of arterial blood sampling and SPECT. For this purpose, the ratio of the arterial blood radioactivity count to the venous blood radioactivity count, the coefficient of variation, and the correlation and differences between arterial blood-based rCBF and venous blood-based rCBF were analyzed. The coefficient of variation was lowest (4.1%) 20 minutes after injection into the dorsum manus. When the relationship between venous and arterial blood counts was analyzed, arterial blood counts correlated well with venous blood counts collected at the dorsum manus 20 or 30 minutes after intravenous injection and with venous blood counts collected at the wrist 20 minutes after intravenous injection (r=0.97 or higher). The difference from rCBF determined on the basis of arterial blood was smallest (0.7) for rCBF determined on the basis of venous blood collected at the dorsum manus 20 minutes after intravenous injection. (author)

Dietary sodium bicarbonate, cool temperatures, and feed withdrawal: impact on arterial and venous blood-gas values in broilers.

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Wideman, R F; Hooge, D M; Cummings, K R

2003-04-01

Sodium bicarbonate (NaHCO3) has been used successfully in mammals and birds to alleviate pulmonary hypertension. Experiment 1 was designed to provide measurements of arterial and venous blood-gas values from unanesthetized male broilers subjected to a cool temperature (16 degrees C) challenge and fed either a control diet or the same diet alkalinized by dilution with 1% NaHCO3. The incidences of pulmonary hypertension syndrome (PHS, ascites) for broilers fed the control or bicarbonate diets were 15.5 and 10.5%, respectively (P = 0.36, NS). Non-ascitic broilers fed the control diet were heavier than those fed the bicarbonate diet on d 49 (2,671 vs. 2,484 g, respectively); however, other comparisons failed to reveal diet-related differences in heart weight, pulse oximetry values, electrocardiogram amplitudes, or blood-gas values (P > 0.05). When the data were resorted into categories based on right:total ventricular weight ratios (RV:TV) indicative of normal (RV:TV or = 0.28) pulmonary arterial pressures, broilers with elevated RV:TV ratios had poorly oxygenated arterial blood that was more acidic, had high partial pressure of CO2 (PCO2), and had higher HCO3 concentrations when compared with broilers with normal RV:TV ratios. Experiment 2 was conducted to determine if metabolic variations associated with differences in feed intake or environmental temperature potentially could mask an impact of diet composition on blood-gas values. Male broilers maintained at thermoneutral temperature (24 degrees C) either received feed ad libitum or had the feed withdrawn > or = 12 h prior to blood sampling. Broilers fed ad libitum had lower venous saturation of hemoglobin with O2, higher venous PCO2, and higher arterial HCO3 concentrations than broilers subjected to feed withdrawal. Broilers in experiment 2 fed ad libitum and exposed to cool temperatures (16 degrees C) had lower arterial partial pressure of O2 and higher venous PCO2 than broilers fed ad libitum and maintained at 24

Coupling between arterial and venous cerebral blood flow during postural change

DEFF Research Database (Denmark)

Ogoh, Shigehiko; Washio, Takuro; Sasaki, Hiroyuki

2016-01-01

In supine humans the main drainage from the brain is through the internal jugular vein (IJV) but the vertebral veins (VV) become important during orthostatic stress because the IJV is partially collapsed. To identify the effect of this shift in venous drainage from the brain on the cerebral...... blood flow (r=0.649, P=0.004) and the two flows were coupled during manipulation of the end-tidal CO2 tension (supine, r=0.551, P=0.004; seated, r=0.612, P

Radioimmunoassay of estrone, estradiol, estriol, progesterone, cortisol and prolactin in maternal venous blood and the cord blood of the newborn child

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Fritschi, J

1980-01-01

The estrone analyses showed that E/sub 1/ levels are not sex-dependent. The Prog/E/sub 2/ ratio changed when the children were in states of exceptional stress; analogous findings were obtained in the acidose group. Due to the wide range of variations of E/sub 3/, it was found to be impossible to determine the stage of pregnancy from the E/sub 3/ level. Progesterone levels were significantly higher in the blood of the umbilical vein than in the umbilical artery. Prolactine levels of both the umbilical vein and the umbilical artery are significantly higher than in the mother's venous blood. Cortisol levels differed with the type of delivery, especially when comparing Caesareon with normal delivery. Also, differences were found between deliveries with more or less stress. There is no significant difference between E/sub 2//prog ratios measured during induced labour, immature delivery, application of analgetics; instead, cortisol levels are best correlated with the clinical criteria of birth stress, especially during the expulsion period in which stress factors are highest. Further, there is a correlation between the cortisol levels of the umbilical vein and the mother's venous-blood.

Radioimmunoassay of estrone, estradiol, estriol, progesterone, cortisol and prolactin in maternal venous blood and the cord blood of the newborn child

International Nuclear Information System (INIS)

Fritschi, J.

1980-01-01

The estrone analyses showed that E 1 levels are not sex-dependent. The Prog/E 2 ratio changed when the children were in states of exceptional stress; analogous findings were obtained in the acidose group. Due to the wide range of variations of E 3 , it was found to be impossible to determine the stage of pregnancy from the E 3 level. Progesterone levels were significantly higher in the blood of the umbilical vein than in the umbilical artery. Prolactine levels of both the umbilical vein and the umbilical artery are significantly higher than in the mother's venous blood. Cortisol levels differed with the type of delivery, especially when comparing Caesareon with normal delivery. Also, differences were found between deliveries with more or less stress. There is no significant difference between E 2 /prog ratios measured during induced labour, immature delivery, application of analgetics; instead, cortisol levels are best correlated with the clinical criteria of birth stress, especially during the expulsion period in which stress factors are highest. Further, there is a correlation between the cortisol levels of the umbilical vein and the mother's venous-blood. (orig./MG) [de

Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe.

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Brøndum, E; Hasenkam, J M; Secher, N H; Bertelsen, M F; Grøndahl, C; Petersen, K K; Buhl, R; Aalkjaer, C; Baandrup, U; Nygaard, H; Smerup, M; Stegmann, F; Sloth, E; Ostergaard, K H; Nissen, P; Runge, M; Pitsillides, K; Wang, T

2009-10-01

How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended in the upright position so that we could lower the head. In the upright position, mean arterial pressure (MAP) was 193 +/- 11 mmHg (mean +/- SE), carotid flow was 0.7 +/- 0.2 l/min, and carotid cross-sectional area was 0.85 +/- 0.04 cm(2). Central venous pressure (CVP) was 4 +/- 2 mmHg, jugular flow was 0.7 +/- 0.2 l/min, and jugular cross-sectional area was 0.14 +/- 0.04 cm(2) (n = 4). Carotid arterial and jugular venous pressures at head level were 118 +/- 9 and -7 +/- 4 mmHg, respectively. When the head was lowered, MAP decreased to 131 +/- 13 mmHg, while carotid cross-sectional area and flow remained unchanged. Cardiac output was reduced by 30%, CVP decreased to -1 +/- 2 mmHg (P blood in the veins. When the head was raised, the jugular veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head is lowered, blood accumulates in the vein, affecting MAP.

Comparison of arterial and venous blood biomarker levels in chronic obstructive pulmonary disease [v1; ref status: indexed, http://f1000r.es/9x

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Emer Kelly

2013-04-01

Full Text Available Purpose: The development of novel biomarkers is an unmet need in chronic obstructive pulmonary disease (COPD. Arterial blood comes directly from the lung and venous blood drains capillary beds of the organ or tissue supplied. We hypothesized that there would be a difference in levels of the biomarkers metalloproteinase 9 (MMP-9, vascular endothelial growth factor A (VEGF-A and interleukin 6 (IL-6 in arterial compared with venous blood.  Methods: Radial artery and brachial vein blood samples were taken simultaneously in each of 12 patients with COPD and seven controls with normal lung function. Circulating immunoreactive MMP-9, VEGF-A and IL-6 levels in serum were measured using quantitative enzyme-linked immunosorbent assays. Results were compared using a Student’s paired t test. The study was powered to determine whether significant differences in cytokine levels were present between paired arterial and venous blood samples.   Results: In the 12 patients with COPD, four were female, and age ranged 53-85 years, mean age 69 years. Three patients in the control group were female, with age range 46-84 years, mean age 64.7 years. In the COPD group, three patients had mild, five moderate and four severe COPD. No significant difference was found between arterial and venous levels of MMP-9, VEGF-A or IL-6.  Conclusions: In this pilot study, levels of the measured biomarkers in arterial compared with venous blood in both COPD patients and healthy controls did not differ. This suggests that as we continue to chase the elusive biomarker in COPD as a potential tool to measure disease activity, we should focus on venous blood for this purpose.

Comparison of two analyzers to determine selected venous blood analytes of Quaker parrots (Myiopsitta monachus).

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Rettenmund, Christy L; Heatley, J Jill; Russell, Karen E

2014-06-01

Point of care devices can assess electrolyte, blood gas, biochemical, and hematologic values in a critical care setting. Although these devices are commonly used in humans and companion mammals, few studies have assessed their use in avian species. This study compares electrolyte, hemoglobin (Hgb), hematocrit (Hct), acid-base, and venous blood gas parameters between the i-STAT and IRMA TruPoint blood gas analysis systems for 35 Quaker parrots. Agreement between the two analyzers and the effect of gender, time lag between sample analysis, and cartridge expiration were evaluated. Male birds had increased Hgb and Hct compared with females, independent of analyzer method. In expired i-STAT cartridges, only glucose significantly increased. Packed cell volume determined by centrifugation was higher than Hct, as calculated by either analyzer. The analyzers had good agreement for total carbon dioxide, bicarbonate, pH, and Hgb, fair agreement for potassium (K), ionized calcium (iCa), venous partial pressure of carbon dioxide, and base excess, and poor agreement for sodium (Na), venous partial pressure of oxygen (PO2), and oxygen saturation (SO2). Values for Na, iCa, PO2, and SO2 were significantly higher on the IRMA than the i-STAT, while K was significantly lower on the IRMA when compared with the i-STAT. The time lag between sample analyses on the i-STAT and IRMA did not be correlate to any analyte changes. Despite these differences, both the i-STAT and the IRMA appear to be acceptable clinical tools in avian critical care, although reference ranges for each analyzer should be created.

Cerebral venous outflow and cerebrospinal fluid dynamics

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Clive B. Beggs

2014-12-01

Full Text Available In this review, the impact of restricted cerebral venous outflow on the biomechanics of the intracranial fluid system is investigated. The cerebral venous drainage system is often viewed simply as a series of collecting vessels channeling blood back to the heart. However there is growing evidence that it plays an important role in regulating the intracranial fluid system. In particular, there appears to be a link between increased cerebrospinal fluid (CSF pulsatility in the Aqueduct of Sylvius and constricted venous outflow. Constricted venous outflow also appears to inhibit absorption of CSF into the superior sagittal sinus. The compliance of the cortical bridging veins appears to be critical to the behaviour of the intracranial fluid system, with abnormalities at this location implicated in normal pressure hydrocephalus. The compliance associated with these vessels appears to be functional in nature and dependent on the free egress of blood out of the cranium via the extracranial venous drainage pathways. Because constricted venous outflow appears to be linked with increased aqueductal CSF pulsatility, it suggests that inhibited venous blood outflow may be altering the compliance of the cortical bridging veins.

Average blood flow and oxygen uptake in the human brain during resting wakefulness

DEFF Research Database (Denmark)

Madsen, P L; Holm, S; Herning, M

1993-01-01

tracer between the brain and its venous blood is not reached. As a consequence, normal values for CBF and CMRO2 of 54 ml 100 g-1 min-1 and 3.5 ml 100 g-1 min-1 obtained with the Kety-Schmidt technique are an overestimation of the true values. Using the Kety-Schmidt technique we have performed 57...... the measured data, we find that the true average values for CBF and CMRO2 in the healthy young adult are approximately 46 ml 100 g-1 min-1 and approximately 3.0 ml 100 g-1 min-1. Previous studies have suggested that some of the variation in CMRO2 values could be ascribed to differences in cerebral venous...

Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood.

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Hussein, H A; Aamer, A A

2013-01-01

The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10), at RT of about 22-25 ºC (Group II, n = 10) and in an incubator adjusted to 37 ºC (Group III, n = 10) for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0), there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (ppO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (preference range and it may be of clinical diagnostic use for up to 6 h.

Risk of venous thromboembolism and myocardial infarction associated with factor V Leiden and prothrombin mutations and blood type

DEFF Research Database (Denmark)

Sode, Birgitte F; Allin, Kristine H; Dahl, Morten

2013-01-01

ABO blood type locus has been reported to be an important genetic determinant of venous and arterial thrombosis in genome-wide association studies. We tested the hypothesis that ABO blood type alone and in combination with mutations in factor V Leiden R506Q and prothrombin G20210A is associated...

Cerebral Blood Flow during Rest Associates with General Intelligence and Creativity

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Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Nagase, Tomomi; Nouchi, Rui; Kawashima, Ryuta

2011-01-01

Recently, much scientific attention has been focused on resting brain activity and its investigation through such methods as the analysis of functional connectivity during rest (the temporal correlation of brain activities in different regions). However, investigation of the magnitude of brain activity during rest has focused on the relative decrease of brain activity during a task, rather than on the absolute resting brain activity. It is thus necessary to investigate the association between cognitive factors and measures of absolute resting brain activity, such as cerebral blood flow (CBF), during rest (rest-CBF). In this study, we examined this association using multiple regression analyses. Rest-CBF was the dependent variable and the independent variables included two essential components of cognitive functions, psychometric general intelligence and creativity. CBF was measured using arterial spin labeling and there were three analyses for rest-CBF; namely mean gray matter rest-CBF, mean white matter rest-CBF, and regional rest-CBF. The results showed that mean gray and white matter rest-CBF were significantly and positively correlated with individual psychometric intelligence. Furthermore, mean white matter rest-CBF was significantly and positively correlated with creativity. After correcting the effect of mean gray matter rest-CBF the significant and positive correlation between regional rest-CBF in the perisylvian anatomical cluster that includes the left superior temporal gyrus and insula and individual psychometric intelligence was found. Also, regional rest-CBF in the precuneus was significantly and negatively correlated with individual creativity. Significance of these results of regional rest-CBF did not change when the effect of regional gray matter density was corrected. The findings showed mean and regional rest-CBF in healthy young subjects to be correlated with cognitive functions. The findings also suggest that, even in young cognitively intact

HIV-1 viral load measurement in venous blood and fingerprick blood using Abbott RealTime HIV-1 DBS assay.

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Tang, Ning; Pahalawatta, Vihanga; Frank, Andrea; Bagley, Zowie; Viana, Raquel; Lampinen, John; Leckie, Gregor; Huang, Shihai; Abravaya, Klara; Wallis, Carole L

2017-07-01

HIV RNA suppression is a key indicator for monitoring success of antiretroviral therapy. From a logistical perspective, viral load (VL) testing using Dried Blood Spots (DBS) is a promising alternative to plasma based VL testing in resource-limited settings. To evaluate the analytical and clinical performance of the Abbott RealTime HIV-1 assay using a fully automated one-spot DBS sample protocol. Limit of detection (LOD), linearity, lower limit of quantitation (LLQ), upper limit of quantitation (ULQ), and precision were determined using serial dilutions of HIV-1 Virology Quality Assurance stock (VQA Rush University), or HIV-1-containing armored RNA, made in venous blood. To evaluate correlation, bias, and agreement, 497 HIV-1 positive adult clinical samples were collected from Ivory Coast, Uganda and South Africa. For each HIV-1 participant, DBS-fingerprick, DBS-venous and plasma sample results were compared. Correlation and bias values were obtained. The sensitivity and specificity were analyzed at a threshold of 1000 HIV-1 copies/mL generated using the standard plasma protocol. The Abbott HIV-1 DBS protocol had an LOD of 839 copies/mL, a linear range from 500 to 1×10 7 copies/mL, an LLQ of 839 copies/mL, a ULQ of 1×10 7 copies/mL, and an inter-assay SD of ≤0.30 log copies/mL for all tested levels within this range. With clinical samples, the correlation coefficient (r value) was 0.896 between DBS-fingerprick and plasma and 0.901 between DBS-venous and plasma, and the bias was -0.07 log copies/mL between DBS-fingerprick and plasma and -0.02 log copies/mL between DBS-venous and plasma. The sensitivity of DBS-fingerprick and DBS-venous was 93%, while the specificity of both DBS methods was 95%. The results demonstrated that the Abbott RealTime HIV-1 assay with DBS sample protocol is highly sensitive, specific and precise across a wide dynamic range and correlates well with plasma values. The Abbott RealTime HIV-1 assay with DBS sample protocol provides an

Determination of reference intervals and comparison of venous blood gas parameters using standard and non-standard collection methods in 24 cats.

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Bachmann, Karin; Kutter, Annette Pn; Schefer, Rahel Jud; Marly-Voquer, Charlotte; Sigrist, Nadja

2017-08-01

Objectives The aim of this study was to determine in-house reference intervals (RIs) for venous blood analysis with the RAPIDPoint 500 blood gas analyser using blood gas syringes (BGSs) and to determine whether immediate analysis of venous blood collected into lithium heparin (LH) tubes can replace anaerobic blood sampling into BGSs. Methods Venous blood was collected from 24 healthy cats and directly transferred into a BGS and an LH tube. The BGS was immediately analysed on the RAPIDPoint 500 followed by the LH tube. The BGSs and LH tubes were compared using paired t-test or Wilcoxon matched-pairs signed-rank test, Bland-Altman and Passing-Bablok analysis. To assess clinical relevance, bias or percentage bias between BGSs and LH tubes was compared with the allowable total error (TEa) recommended for the respective parameter. Results Based on the values obtained from the BGSs, RIs were calculated for the evaluated parameters, including blood gases, electrolytes, glucose and lactate. Values derived from LH tubes showed no significant difference for standard bicarbonate, whole blood base excess, haematocrit, total haemoglobin, sodium, potassium, chloride, glucose and lactate, while pH, partial pressure of carbon dioxide and oxygen, actual bicarbonate, extracellular base excess, ionised calcium and anion gap were significantly different to the samples collected in BGSs ( P glucose and lactate can be made based on blood collected in LH tubes and analysed within 5 mins. For pH, partial pressure of carbon dioxide and oxygen, extracellular base excess, anion gap and ionised calcium the clinically relevant alterations have to be considered if analysed in LH tubes.

Arterio-venous concentration difference of [51Cr]EDTA after a single injection in man. Significance of renal function and local blood flow

DEFF Research Database (Denmark)

Rehling, M; Hyldstrup, L; Henriksen, Jens Henrik Sahl

1989-01-01

, whereas the difference was very sensitive to even small changes in forearm blood flow within the physiological range. For measurement of renal plasma clearance it is recommended to use one long period: from the time of injection until 300 min p.i. or longer. If the clearance period is too short, the use...... introduced in the measurement of renal plasma clearance and total plasma clearance by using venous blood samples instead of arterial. In 13 patients with GFR ranging from 29 to 150 ml min-1, Ca was higher than Cv immediately after the injection. After mean 38 min (range 12-82 min) the two curves crossed...... of venous samples will overestimate the true renal clearance. Plasma clearance determined by venous and arterial blood samples does not differ significantly as long as the concentration is followed from the time of injection and a long period is applied. When simplified plasma clearance techniques are used...

Comparative biochemical analyses of venous blood and peritoneal fluid from horses with colic using a portable analyser and an in-house analyser.

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Saulez, M N; Cebra, C K; Dailey, M

2005-08-20

Fifty-six horses with colic were examined over a period of three months. The concentrations of glucose, lactate, sodium, potassium and chloride, and the pH of samples of blood and peritoneal fluid, were determined with a portable clinical analyser and with an in-house analyser and the results were compared. Compared with the in-house analyser, the portable analyser gave higher pH values for blood and peritoneal fluid with greater variability in the alkaline range, and lower pH values in the acidic range, lower concentrations of glucose in the range below 8.3 mmol/l, and lower concentrations of lactate in venous blood in the range below 5 mmol/l and in peritoneal fluid in the range below 2 mmol/l, with less variability. On average, the portable analyser underestimated the concentrations of lactate and glucose in peritoneal fluid in comparison with the in-house analyser. Its measurements of the concentrations of sodium and chloride in peritoneal fluid had a higher bias and were more variable than the measurements in venous blood, and its measurements of potassium in venous blood and peritoneal fluid had a smaller bias and less variability than the measurements made with the in-house analyser.

Blood flow distribution in dog gastrocnemius muscle at rest and during stimulation

International Nuclear Information System (INIS)

Piiper, J.; Pendergast, D.R.; Marconi, C.; Meyer, M.; Heisler, N.; Cerretelli, P.

1985-01-01

The distribution of blood flow within the isolated perfused dog gastrocnemius muscle (weight 100-240 g) was studied by intra-arterial injection of radioactively labeled microspheres (diameter 15 micron) at rest and during supramaximal stimulation to rhythmic isotonic tetanic contractions of varied frequency against varied loads. After the experiment the muscle was cut into 180-250 pieces of approximately 0.75 g each, and the blood flow to each muscle piece was determined from its radioactivity. The inhomogeneity of blood flow was represented as the frequency distribution of the ratios of regional specific blood flow, i.e., blood flow per unit tissue weight of the piece, QR, to the overall specific blood flow of the muscle, Q. The QR/Q values for the individual pieces of a muscle were found to vary widely both at rest and during stimulation. With rising work load the frequency distribution had a tendency to broaden and flatten, indicating increasing perfusion inhomogeneity. On the average of the experiments, there was no significant difference in specific blood flow between the three anatomic components of the gastrocnemius (lateral and medial heads of gastrocnemius and flexor digitorum superficialis) nor between the superficial and deep portions within these anatomic components, only the distal third of the muscle was relatively less perfused compared with the proximal two-thirds. The considerable inhomogeneity of blood flow as revealed by microsphere embolization and by other methods is expected to exert important limiting effects on local O 2 supply, particularly during exercise

Automated artery-venous classification of retinal blood vessels based on structural mapping method

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Joshi, Vinayak S.; Garvin, Mona K.; Reinhardt, Joseph M.; Abramoff, Michael D.

2012-03-01

Retinal blood vessels show morphologic modifications in response to various retinopathies. However, the specific responses exhibited by arteries and veins may provide a precise diagnostic information, i.e., a diabetic retinopathy may be detected more accurately with the venous dilatation instead of average vessel dilatation. In order to analyze the vessel type specific morphologic modifications, the classification of a vessel network into arteries and veins is required. We previously described a method for identification and separation of retinal vessel trees; i.e. structural mapping. Therefore, we propose the artery-venous classification based on structural mapping and identification of color properties prominent to the vessel types. The mean and standard deviation of each of green channel intensity and hue channel intensity are analyzed in a region of interest around each centerline pixel of a vessel. Using the vector of color properties extracted from each centerline pixel, it is classified into one of the two clusters (artery and vein), obtained by the fuzzy-C-means clustering. According to the proportion of clustered centerline pixels in a particular vessel, and utilizing the artery-venous crossing property of retinal vessels, each vessel is assigned a label of an artery or a vein. The classification results are compared with the manually annotated ground truth (gold standard). We applied the proposed method to a dataset of 15 retinal color fundus images resulting in an accuracy of 88.28% correctly classified vessel pixels. The automated classification results match well with the gold standard suggesting its potential in artery-venous classification and the respective morphology analysis.

Tracer disposition kinetics in the determination of local cerebral blood flow by a venous equilibrium model, tube model, and distributed model

International Nuclear Information System (INIS)

Sawada, Y.; Sugiyama, Y.; Iga, T.; Hanano, M.

1987-01-01

Tracer distribution kinetics in the determination of local cerebral blood flow (LCBF) were examined by using three models, i.e., venous equilibrium, tube, and distributed models. The technique most commonly used for measuring LCBF is the tissue uptake method, which was first developed and applied by Kety. The measurement of LCBF with the 14 C-iodoantipyrine (IAP) method is calculated by using an equation derived by Kety based on the Fick's principle and a two-compartment model of blood-tissue exchange and tissue concentration at a single data point. The procedure, in which the tissue is to be in equilibrium with venous blood, will be referred to as the tissue equilibration model. In this article, effects of the concentration gradient of tracer along the length of the capillary (tube model) and the transverse heterogeneity in the capillary transit time (distributed model) on the determination of LCBF were theoretically analyzed for the tissue sampling method. Similarities and differences among these models are explored. The rank order of the LCBF calculated by using arterial blood concentration time courses and the tissue concentration of tracer based on each model were tube model (model II) less than distributed model (model III) less than venous equilibrium model (model I). Data on 14 C-IAP kinetics reported by Ohno et al. were employed. The LCBFs calculated based on model I were 45-260% larger than those in models II or III. To discriminate among three models, we propose to examine the effect of altering the venous infusion time of tracer on the apparent tissue-to-blood concentration ratio (lambda app). A range of the ratio of the predicted lambda app in models II or III to that in model I was from 0.6 to 1.3

Abnormal Resting State Corticolimbic Blood Flow in Depressed Unmedicated Patients With Major Depression: A 15O-H2O PET Study

OpenAIRE

Monkul, E. Serap; Silva, Leandro A.P.; Narayana, Shalini; Peluso, Marco A.M.; Zamarripa, Frank; Nery, Fabiano G.; Najt, Pablo; Li, John; Lancaster, Jack L.; Fox, Peter T.; Lafer, Beny; Soares, Jair C.

2011-01-01

We investigated the differences in the resting state corticolimbic blood flow between 20 unmedicated depressed patients and 21 healthy comparisons. Resting state cerebral blood flow (CBF) was measured with H215O PET. Anatomical MRI scans were performed on an Elscint 1.9 T Prestige system for PET-MRI coregistration. Significant changes in cerebral blood flow indicating neural activity were detected using an ROI-free image subtraction strategy. In addition, the resting blood flow in patients wa...

Reduction of carboxyhaemoglobin levels in the venous blood of cigarette smokers following the administration of carbogen

International Nuclear Information System (INIS)

Macdonald, Graham; Kondor, Natalie; Yousefi, Vandad; Green, Alex; Wong, Frances; Aquino-Parsons, Christina

2004-01-01

Cigarette smokers have high carboxyhaemoglobin levels which can promote tumour radioresistance. Inhalation of carbogen gas shortens the half-life of carboxyhaemoglobin, increasing tumour radiosensitivity in animal models. Breathing 2.5% carbogen for 30 min results in a greater reduction in venous blood COHb levels than breathing 5% carbogen for 7 min

Identification of Voxels Confounded by Venous Signals Using Resting-State fMRI Functional Connectivity Graph Clustering

Directory of Open Access Journals (Sweden)

Klaudius eKalcher

2015-12-01

Full Text Available Identifying venous voxels in fMRI datasets is important to increase the specificity of fMRI analyses to microvasculature in the vicinity of the neural processes triggering the BOLD response. This is, however, difficult to achieve in particular in typical studies where magnitude images of BOLD EPI are the only data available. In this study, voxelwise functional connectivity graphs were computed on minimally preprocessed low TR (333 ms multiband resting-state fMRI data, using both high positive and negative correlations to define edges between nodes (voxels. A high correlation threshold for binarization ensures that most edges in the resulting sparse graph reflect the high coherence of signals in medium to large veins. Graph clustering based on the optimization of modularity was then employed to identify clusters of coherent voxels in this graph, and all clusters of 50 or more voxels were then interpreted as corresponding to medium to large veins. Indeed, a comparison with SWI reveals that 75.6 ± 5.9% of voxels within these large clusters overlap with veins visible in the SWI image or lie outside the brain parenchyma. Some of the remainingdifferences between the two modalities can be explained by imperfect alignment or geometric distortions between the two images. Overall, the graph clustering based method for identifying venous voxels has a high specificity as well as the additional advantages of being computed in the same voxel grid as the fMRI dataset itself and not needingany additional data beyond what is usually acquired (and exported in standard fMRI experiments.

Regular sports activities decrease the risk of venous thrombosis

NARCIS (Netherlands)

van Stralen, K. J.; le Cessie, S.; Rosendaal, F. R.; Doggen, C. J. M.

2007-01-01

BACKGROUND: Stasis of the blood has been postulated as a major cause of venous thrombosis. However, little is known about the effect of stimulating the blood flow in order to prevent venous thrombosis through, for example, sports activities. OBJECTIVES: In a large population-based case-control study

The post-occipital spinal venous sinus of the Nile crocodile (Crocodylus niloticus: Its anatomy and use for blood sample collection and intravenous infusions

Directory of Open Access Journals (Sweden)

Jan G. Myburgh

2014-05-01

Full Text Available The post-occipital sinus of the spinal vein is often used for the collection of blood samples from crocodilians. Although this sampling method has been reported for several crocodilian species, the technique and associated anatomy has not been described in detail in any crocodilian, including the Nile crocodile (Crocodylus niloticus. The anatomy of the cranial neck region was investigated macroscopically, microscopically, radiographically and by means of computed tomography. Latex was injected into the spinal vein and spinal venous sinus of crocodiles to visualise the regional vasculature. The spinal vein ran within the vertebral canal, dorsal to and closely associated with the spinal cord and changed into a venous sinus cranially in the post-occipital region. For blood collection, the spinal venous sinus was accessed through the interarcuate space between the atlas and axis (C1 and C2 by inserting a needle angled just off the perpendicular in the midline through the craniodorsal cervical skin, just cranial to the cranial borders of the first cervical osteoderms. The most convenient method of blood collection was with a syringe and hypodermic needle. In addition, the suitability of the spinal venous sinus for intravenous injections and infusions in live crocodiles was evaluated. The internal diameter of the commercial human epidural catheters used during these investigations was relatively small, resulting in very slow infusion rates. Care should be taken not to puncture the spinal cord or to lacerate the blood vessel wall using this route for blood collection or intravenous infusions.

CD4+ LYMPHOCYTES IMPROVE VENOUS BLOOD FLOW IN EXPERIMENTAL ARTERIOVENOUS FISTULAE

Science.gov (United States)

Duque, Juan C.; Martinez, Laisel; Mesa, Annia; Wei, Yuntao; Tabbara, Marwan; Salman, Loay H.; Vazquez-Padron, Roberto I.

2015-01-01

Background The role of immune cells in arteriovenous fistulae (AVF) maturation is poorly understood and has received, until quite recently, little attention. This study examines the role of T lymphocytes in AVF vascular remodeling. Methods Experimental fistulae were created in athymic rnu nude rats lacking mature T lymphocytes and euthymic control animals by anastomosing the left superior epigastric vein to the nearby femoral artery. Blood flow rates, wall morphology and histological changes were assessed in AVF 21 days after creation. The effect of CD4+ lymphocytes on AVF maturation in athymic animals was analyzed by adoptive transfer of cells after fistula creation. Results The absence of T lymphocytes compromised blood flow in experimental fistulae. Histopathological inspection of AVF from athymic rats revealed that T cell immunodeficiency negatively affected venous vascular remodeling, as evidenced by a reduced lumen, a thick muscular layer and a low number of inflammatory cells compared to control animals. Adoptive transfer of CD4+ lymphocytes from euthymic rats into athymic animals before and after fistula creation improved blood flow and reduced intima-media thickness. Conclusion These results point at the protective role of CD4+ lymphocytes in the remodeling of the AVF vascular wall. PMID:25999254

Rapid dual-injection single-scan 13N-ammonia PET for quantification of rest and stress myocardial blood flows

International Nuclear Information System (INIS)

Rust, T C; DiBella, E V R; McGann, C J; Christian, P E; Hoffman, J M; Kadrmas, D J

2006-01-01

Quantification of myocardial blood flows at rest and stress using 13 N-ammonia PET is an established method; however, current techniques require a waiting period of about 1 h between scans. The objective of this study was to test a rapid dual-injection single-scan approach, where 13 N-ammonia injections are administered 10 min apart during rest and adenosine stress. Dynamic PET data were acquired in six human subjects using imaging protocols that provided separate single-injection scans as gold standards. Rest and stress data were combined to emulate rapid dual-injection data so that the underlying activity from each injection was known exactly. Regional blood flow estimates were computed from the dual-injection data using two methods: background subtraction and combined modelling. The rapid dual-injection approach provided blood flow estimates very similar to the conventional single-injection standards. Rest blood flow estimates were affected very little by the dual-injection approach, and stress estimates correlated strongly with separate single-injection values (r = 0.998, mean absolute difference = 0.06 ml min -1 g -1 ). An actual rapid dual-injection scan was successfully acquired in one subject and further demonstrates feasibility of the method. This study with a limited dataset demonstrates that blood flow quantification can be obtained in only 20 min by the rapid dual-injection approach with accuracy similar to that of conventional separate rest and stress scans. The rapid dual-injection approach merits further development and additional evaluation for potential clinical use

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

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....

Evaluation of venous congestion in dural arteriovenous fistulae using the acetazolamide test

International Nuclear Information System (INIS)

Deguchi, Jun; Yamada, Makoto; Kobata, Hitoshi; Kuroiwa, Toshihiko

2002-01-01

The pattern of venous drainage determines the clinical presentation of dural arteriovenous fistulas (AVFs). We assessed the degree of venous congestion in dural AVFs using acetazolamide test and stable Xenon-CT. In 11 patients (8 sigmoid-transverse dural AVFs, 3 cavernous dural AVFs) before treatment and in 8 patients 6 months after treatment, cerebral hemodynamics were studied by stable Xenon-CT. Regions of interest (ROI) were placed in the temporo-occipital region in cases of sigmoid-transverse AVFs, and in the frontal operculum in cases of cavernous AVFs. Patients were classified into 5 groups according to Cognard's classification. In the groups without venous reflux (Cognard type I) and reflux only to the venous sinus (type IIa), regional cerebral blood flow (rCBF) at rest and after acetazolamide challenge were normal. In the group showing reflux to the cortical vein (type IIb), the increase in rCBF after acetazolamide challenge on the lesion side was less than that on the opposite side. In the group showing reflux to both cortical vein and sinus (type IIa+b), rCBF did not increase after acetazolamide challenge. The CBF and increase in rCBF after acetazolamide in the symptomatic group were significantly lower than those in the asymptomatic group. After embolization, the increase in rCBF by acetazolamide improved in all except for type III cases. Cerebral venous hypertension in dural AVFs causes weak response to acetazolamide challenge. The degree of venous hypertension can be evaluated quantitatively by acetazolamide challenge and stable Xenon-CT. Therefore acetazolamide challenge is useful for determination of the embolization of dural AVFs. (author)

Bone blood flow in conscious dogs at rest and during exercise

International Nuclear Information System (INIS)

Toendevold, E.; Buelow, J.

1983-01-01

Using the microsphere technique bone flow was measured in different anatomical and functional regions in long bones in conscious dogs. The measurements were performed during physical exercise upon a treadmill, and the bone blood flow values were obtained as prework resting values after 1 and 2 hours of exercise and after 1 hour of rest. The perfusion rates increased 50 per cent from 1.6 to 2.5 ml x 100 g tissue - 1 x min - 1 in the femoral and tibial cortical bones during work. In the cancelleous bone of the femoral head an increase from 12.6 to 20.6 ml x 100 g tissue - 1 x min - 1 was found. Equal flow responses were determined in the fat-filled tibia-condylar and femoral supracondylar bone. The increase took place after 2 hours' exercise, but nonstatistically verified increased perfusion was found after 1 hour's work. The alternation in bone blood flow suggest that bone has a capability of physical vasodilatation during muscular work but the flow response is slow and therefore the vasodilatation seems mediated by a metabolically induced stimulus. (author)

Relationship between Resting Heart Rate, Blood Pressure and Pulse Pressure in Adolescents.

Science.gov (United States)

Christofaro, Diego Giulliano Destro; Casonatto, Juliano; Vanderlei, Luiz Carlos Marques; Cucato, Gabriel Grizzo; Dias, Raphael Mendes Ritti

2017-05-01

High resting heart rate is considered an important factor for increasing mortality chance in adults. However, it remains unclear whether the observed associations would remain after adjustment for confounders in adolescents. To analyze the relationship between resting heart rate, blood pressure and pulse pressure in adolescents of both sexes. A cross-sectional study with 1231 adolescents (716 girls and 515 boys) aged 14-17 years. Heart rate, blood pressure and pulse pressure were evaluated using an oscillometric blood pressure device, validated for this population. Weight and height were measured with an electronic scale and a stadiometer, respectively, and waist circumference with a non-elastic tape. Multivariate analysis using linear regression investigated the relationship between resting heart rate and blood pressure and pulse pressure in boys and girls, controlling for general and abdominal obesity. Higher resting heart rate values were observed in girls (80.1 ± 11.0 beats/min) compared to boys (75.9 ± 12.7 beats/min) (p ≤ 0.001). Resting heart rate was associated with systolic blood pressure in boys (Beta = 0.15 [0.04; 0.26]) and girls (Beta = 0.24 [0.16; 0.33]), with diastolic blood pressure in boys (Beta = 0.50 [0.37; 0.64]) and girls (Beta = 0.41 [0.30; 0.53]), and with pulse pressure in boys (Beta = -0.16 [-0.27; -0.04]). This study demonstrated a relationship between elevated resting heart rate and increased systolic and diastolic blood pressure in both sexes and pulse pressure in boys even after controlling for potential confounders, such as general and abdominal obesity. A frequência cardíaca de repouso é considerada um importante fator de aumento de mortalidade em adultos. Entretanto, ainda é incerto se as associações observadas permanecem após ajuste para fatores de confusão em adolescentes. Analisar a relação entre frequência cardíaca de repouso, pressão arterial e pressão de pulso em adolescentes dos dois sexos. Estudo transversal

Chronic impairment of leg muscle blood flow following cardiac catheterization in childhood

International Nuclear Information System (INIS)

Skovranek, J.; Samanek, M.

1979-01-01

In 99 patients with congenital heart defects or chronic respiratory disease without clinical symptoms of disturbances in peripheral circulation, resting and maximal blood flow in the anterior tibial muscle of both extremities were investigated 2.7 yrs (average) after cardiac catheterization. The method used involved 133 Xe clearance. Resting blood flow was normal and no difference could be demonstrated between the extremity originally used for catheterization and the contralateral control extremity. No disturbance in maximal blood flow could be proved in the extremity used for catheterization by the venous route only. Maximal blood flow was significantly lower in that extremity where the femoral artery had been catheterized or cannulated for pressure measurement and blood sampling. The disturbance in maximal flow was shown regardless of whether the arterial catheterization involved the Seldinger percutaneous technique, arteriotomy, or mere cannulation of the femoral artery. The values in the involved extremity did not differ significantly from the values in a healthy population

Evaluation of potentially significant increase of lead in the blood during long-term bed rest and space flight.

Science.gov (United States)

Kondrashov, Vladislav; Rothenberg, Stephen J; Chettle, David; Zerwekh, Joseph

2005-02-01

We address a gap in the knowledge of lead turnover under conditions of prolonged bed rest and microgravity by developing a quantitative model of the amount of lead returned to blood circulation from bone. We offer the hypothesis that skeletal unloading, such as typically occurs during extended bed rest or microgravity, will result in bone lead being released to the blood, as has already been demonstrated in the case of calcium. We use initial bone lead concentrations to develop predictive models of blood lead elevation. Our theoretical calculations with typical bone lead loads measured in today's 40-60-year-old generation, suggest that the estimated blood lead concentrations in long duration (e.g., 100 days) space flight could average between 20 and 40 microg dl(-1), a range with well-established toxic effects. For a similar duration of bed rest, estimated blood lead concentration could be as high as 10-20 microg dl(-1), which is a level of concern, particularly if we consider females of childbearing age. The preliminary experimental results were obtained under multi-institutional collaborations, with the main outcome received from an on-going bed rest study, Prevention of Microgravity-Induced Stone Risk by KMgCitrate, conducted at the General Clinical Research Center (GCRC) of the University of Texas Southwestern Medical Center, Dallas. Based on theoretical modeling and some preliminary experimental results, this concept may have important clinical implications by allowing prediction of the magnitude of blood lead elevation, thereby establishing the means to prevent lead toxicity during long duration space flight of astronauts and in conditions of prolonged bed rest such as complicated pregnancy, spinal cord injury induced paralysis and comatose patients.

Thromboelastometry versus standard coagulation tests versus restrictive protocol to guide blood transfusion prior to central venous catheterization in cirrhosis: study protocol for a randomized controlled trial.

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Rocha, Leonardo Lima; Pessoa, Camila Menezes Souza; Neto, Ary Serpa; do Prado, Rogerio Ruscitto; Silva, Eliezer; de Almeida, Marcio Dias; Correa, Thiago Domingos

2017-02-27

Liver failure patients have traditionally been empirically transfused prior to invasive procedures. Blood transfusion is associated with immunologic and nonimmunologic reactions, increased risk of adverse outcomes and high costs. Scientific evidence supporting empirical transfusion is lacking, and the best approach for blood transfusion prior to invasive procedures in cirrhotic patients has not been established so far. The aim of this study is to compare three transfusion strategies (routine coagulation test-guided - ordinary or restrictive, or thromboelastometry-guided) prior to central venous catheterization in critically ill patients with cirrhosis. Design and setting: a double-blinded, parallel-group, single-center, randomized controlled clinical trial in a tertiary private hospital in São Paulo, Brazil. adults (aged 18 years or older) admitted to the intensive care unit with cirrhosis and an indication for central venous line insertion. Patients will be randomly assigned to three groups for blood transfusion strategy prior to central venous catheterization: standard coagulation tests-based, thromboelastometry-based, or restrictive. The primary efficacy endpoint will be the proportion of patients transfused with any blood product prior to central venous catheterization. The primary safety endpoint will be the incidence of major bleeding. Secondary endpoints will be the proportion of transfusion of fresh frozen plasma, platelets and cryoprecipitate; infused volume of blood products; hemoglobin and hematocrit before and after the procedure; intensive care unit and hospital length of stay; 28-day and hospital mortality; incidence of minor bleeding; transfusion-related adverse reactions; and cost analysis. This study will evaluate three strategies to guide blood transfusion prior to central venous line placement in severely ill patients with cirrhosis. We hypothesized that thromboelastometry-based and/or restrictive protocols are safe and would significantly

Abnormal resting state corticolimbic blood flow in depressed unmedicated patients with major depression: a (15)O-H(2)O PET study.

Science.gov (United States)

Monkul, E Serap; Silva, Leandro A P; Narayana, Shalini; Peluso, Marco A M; Zamarripa, Frank; Nery, Fabiano G; Najt, Pablo; Li, John; Lancaster, Jack L; Fox, Peter T; Lafer, Beny; Soares, Jair C

2012-02-01

We investigated the differences in the resting state corticolimbic blood flow between 20 unmedicated depressed patients and 21 healthy comparisons. Resting state cerebral blood flow (CBF) was measured with H(2)(15)O PET. Anatomical MRI scans were performed on an Elscint 1.9 T Prestige system for PET-MRI coregistration. Significant changes in cerebral blood flow indicating neural activity were detected using an ROI-free image subtraction strategy. In addition, the resting blood flow in patients was correlated with the severity of depression as measured by HAM-D scores. Depressed patients showed decreases in blood flow in right anterior cingulate (Brodmann areas 24 and 32) and increased blood flow in left and right posterior cingulate (Brodmann areas 23, 29, 30), left parahippocampal gyrus (Brodmann area 36), and right caudate compared with healthy volunteers. The severity of depression was inversely correlated with the left middle and inferior frontal gyri (Brodmann areas 9 and 47) and right medial frontal gyrus (Brodmann area 10) and right anterior cingulate (Brodmann areas 24, 32) blood flow, and directly correlated with the right thalamus blood flow. These findings support previous reports of abnormalities in the resting state blood flow in the limbic-frontal structures in depressed patients compared to healthy volunteers. Copyright © 2011 Wiley Periodicals, Inc.

The effects of hypotension on differences between the results of simultaneous venous and arterial blood gas analysis

Directory of Open Access Journals (Sweden)

Farhad Shirani

2011-01-01

Full Text Available Background: Analysis of venous blood gas (VBG can represent arterial blood gas (ABG analysis in patients with various diseases. The effects of hypotension on differences between the results of simultaneous venous and arterial blood gas analyses were reviewed. Methods: This observational, cross-sectional study was conducted from March to October 2010 in emergency depart-ments of two university hospitals in Tehran (Iran on consecutive adult patients for whom ABG had been indicated for diagnosis/treatment. Arterial and peripheral venous bloods were simultaneously sampled with blood pressure measure-ment. The VBG-ABG amount of difference regarding pH, HCO 3 , PCO 2 , PO 2 , SO 2 , and Base Excess (BE was com-pared between those with and without hypotension. Results: During the study, 192 patients (51.6 ± 23.6 years, 67.7% males were entered into the hypotension (n = 78 and normotensive groups (n = 114. The average VBG-ABG amount of difference (95% limits of agreement in the hypotension versus normotensive group were -0.030 (-0.09 to 0.03 vs. -0.016 (-0.1 to 0.068 for pH (p = 0.01, 1.79 (-1.91 to 5.49 vs. 1.32 (-1.94 to 4.58 mEq/L for HCO 3 (p = 0.032, 2.69 (-20.43 to 25.81 vs. 2.03 (-7.75 to 11.81 mmHg for PCO 2 (p = 0.295, -35.97 (-130.17 to 58.23 vs. -32.65 (-104.79 to 39.49 mmHg for PO 2 (p = 0.293, -18.58 (-14.66 to 51.82 vs. -9.06 (-31.28 to 13.16 percent (p < 0.001 for SO 2 , and 0.25 (-3.73 to 4.23 vs. 0.79 (-2.51 to 4.09 for BE (p = 0.036. Conclusions: Hypotensive status is associated with an increase in the amount of difference between VBG and ABG analysis regarding pH, HCO 3 , and BE, though the amount of increase does not seem to be clinically important. Studying the precise effects of replacing ABG with VBG on the clinical decision-making and the following outcomes is worth-while.

The Essentials of Parathyroid Hormone Venous Sampling

Energy Technology Data Exchange (ETDEWEB)

Taslakian, Bedros, E-mail: btaslakian@gmail.com [NYU Langone Medical Center, Department of Radiology, NYU School of Medicine (United States); Trerotola, Scott O., E-mail: streroto@uphs.upenn.edu [Perelman School of Medicine of the University of Pennsylvania, Department of Radiology (United States); Sacks, Barry, E-mail: bsacks@bidmc.harvard.edu [Beth Israel Deaconess Medical Center, Department of Interventional Radiology (United States); Oklu, Rahmi, E-mail: oklu.rahmi@mayo.edu [Mayo Clinic, Department of Interventional Radiology (United States); Deipolyi, Amy, E-mail: deipolya@mskcc.org [Memorial Sloan Kettering Cancer Center, Department of Radiology (United States)

2017-01-15

Hyperparathyroidism is an excess of parathyroid hormone in the blood due to over-activity of one or more parathyroid gland. Localization of abnormal glands with noninvasive imaging modalities, such as technetium sestamibi scan and cross-sectional imaging, has a high success rate. Parathyroid venous sampling is performed for patients with persistent or recurrent disease after previous parathyroid surgery, when repeat noninvasive imaging studies are negative or discordant. The success of invasive localization studies and results interpretation is dependent on the interventional radiologist’s understanding of the normal and ectopic anatomic locations of parathyroid glands, as well as their blood supply and venous drainage. Anatomic and technical considerations for selective parathyroid venous sampling are reviewed.

Air travel and venous thrombosis : results of the WRIGHT study : Part I: Epidemiology

NARCIS (Netherlands)

Kuipers, Saskia

2009-01-01

In venous thrombosis, a blood clot develops in a vein, usually a deep vein of the leg, causing obstruction of the blood flow. Venous thrombosis is a multicausal disease, in which genes and environment interact. One of the environmental factors that increases the risk of venous thrombosis is long

Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe

DEFF Research Database (Denmark)

Brøndum, E.; Hasenkam, John Michael; Secher, Niels H.

2009-01-01

How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended...... veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head...... in the upright position so that we could lower the head. In the upright position, mean arterial pressure (MAP) was 193 +/- 11 mmHg (mean +/- SE), carotid flow was 0.7 +/- 0.2 l/min, and carotid cross-sectional area was 0.85 +/- 0.04 cm(2). Central venous pressure (CVP) was 4 +/- 2 mmHg, jugular flow was 0...

Near-infrared vascular imaging in peripheral venous and arterial access

OpenAIRE

Cuper, N.J.

2012-01-01

Venous and arterial access are among the most widespread medical procedures performed in children. Especially in young children venous and arterial access can be problematic due to tiny blood vessels that are difficult to localize beneath a layer of baby fat. This thesis describes the development and clinical evaluation of the VascuLuminator, a guidance tool for peripheral venous and arterial access by visualizing blood vessels underneath the skin with near-infrared light. In a third to a fif...

Venous Thromboembolism in Patients With Thrombocytopenia

DEFF Research Database (Denmark)

Bælum, Jens Kristian; Ellingsen Moe, Espen; Nybo, Mads

2017-01-01

BACKGROUND: Venous thromboembolism (VTE) is a frequent and potentially lethal condition. Venous thrombi are mainly constituted of fibrin and red blood cells, but platelets also play an important role in VTE formation. Information about VTE in patients with thrombocytopenia is, however, missing. O...... having thrombocytopenia with VTE seem to be safely treated with anticoagulants without increased occurrence of bleeding....

Diagnosis and endovascular treatment of multiple cerebral venous and venous sinuses thrombosis

International Nuclear Information System (INIS)

Li Baomin; Zhang Ji; Yin Ling; Huang Xusheng; Jiang Jinli; Liu Jun; Lang Senyang; Zhou Dingbiao; Zhu Ke

2000-01-01

Objective: Eighty-five cases with multiple cerebral venous and venous sinuses thrombosis including the diagnosis and endovascular therapy were reported. Methods: The long T2 and short T1 signals in the related regions of multiple venous sinuses on MRI and prolonged blood circulation time of the brain with tortuous dilatation of vein in angiography were the important characteristics for the diagnosis. Of the 85 cases, the treatment procedures were consisted of injecting urokinase intermittently via common carotid artery and intra-sinus contact thrombolysis as well as warfarin intake orally. Results: Intracranial pressure of 80 cases reduced down between 230 and 300 mm H 2 O, and clinical deficits were markedly improved within 10 days. Re-angiography of 18 cases revealed recanalization partly in 5 cases and circulation time appeared near normal i 8 cases during one week after therapy. Conclusions: Combined intraarterial thrombolysis consecutively with general anticoagulation for the treatment of multiple thrombosis in cerebral venous sinuses may be one of the effective means

Effect of Smoking on Blood Pressure and Resting Heart Rate

DEFF Research Database (Denmark)

Linneberg, Allan; Jacobsen, Rikke K; Skaaby, Tea

2015-01-01

BACKGROUND: -Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. METHODS AND RESULTS: -Data on 141,317 participants (62,666 never, 40,669 former, 37,982 current smokers) from 23 population-based studies were...... for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower SBP, DBP, and lower hypertension risk, but with higher resting heart rate. In observational analyses amongst current smokers, one cigarette/day higher level of smoking...... heaviness was associated with higher (0.21 beats/minute; 95% CI 0.19; 0.24) resting heart rate, and slightly higher DBP (0.05 mmHg; 95% CI 0.02; 0.08) and SBP (0.08 mmHg; 95% CI 0.03; 0.13). However, in MR analyses amongst current smokers, while each smoking increasing allele of rs16969968/rs1051730...

Modulation of blood pressure response to exercise by physical activity and relationship with resting blood pressure during pregnancy.

Science.gov (United States)

Bisson, Michèle; Rhéaume, Caroline; Bujold, Emmanuel; Tremblay, Angelo; Marc, Isabelle

2014-07-01

To determine whether physical activity and blood pressure (BP) response to exercise in early pregnancy are related to resting BP at the end of pregnancy. Understanding physiological BP responses to exercise during pregnancy will help in improving BP profile and guiding exercise recommendations in pregnant women. Maternal physical activity, cardiorespiratory fitness (VO2peak) and BP (systolic and diastolic) at rest and during exercise (submaximal and relative response) were assessed at 16 weeks of gestation in 61 normotensive pregnant women. BP at 36 weeks of gestation and obstetrical outcomes were collected from maternal charts. Related to resting DBP at 16 weeks (r =  -0.28, P = 0.028), total energy expenditure spend at any physical activity in early pregnancy was also associated with resting SBP at 36 weeks (r =  -0.27, P = 0.038). On the contrary, although related to VO2peak (r =  -0.57, P sports and exercise (r =  -0.29, P = 0.024), the relative SBP response to exercise at 16 weeks was not associated with resting BP at 36 weeks. Strongly associated with resting BP at 16 weeks and also with total energy expenditure, submaximal BP response to exercise at 16 weeks was related to resting SBP and DBP at 36 weeks (r = 0.41, P = 0.001 and r = 0.26, P = 0.051, respectively). In normotensive women, physical activity performed in early pregnancy appears to slightly modulate resting BP in early and late pregnancy. However, further investigations are needed to determine which physical activity-related parameter in response to exercise best predicts BP variations during pregnancy.

Impaired autoregulation of blood flow in subcutaneous tissue of long-term type 1 (insulin-dependent) diabetic patients with microangiopathy

DEFF Research Database (Denmark)

Kastrup, J; Nørgaard, T; Parving, H H

1985-01-01

subjects. Blood flow was measured by the local 133Xenon washout technique. Mean arterial blood pressure was reduced by a maximum of 23 mmHg by elevating the limb above heart level and elevating to a maximum of 70 mmHg by head-up tilt; in the latter position venous pressure was kept constant and low...... with clinical microangiopathy, autoregulation of blood flow was impaired, blood flow changing approximately 20% per 10 mmHg change in arterial blood pressure; the slope of the autoregulation curves was significantly higher compared with the two control groups (p less than 0.02). Resting mean arterial blood...

The Effect of Low Volume Interval Training on Resting Blood Pressure in Pre-hypertensive Subjects: A Preliminary Study.

Science.gov (United States)

Skutnik, Benjamin C; Smith, Joshua R; Johnson, Ariel M; Kurti, Stephanie P; Harms, Craig A

2016-01-01

Clinically pre-hypertensive adults are at a greater risk of developing hypertension, stiffened arteries, and other cardiovascular risks. Endurance exercise training has been shown to improve elevated resting blood pressure and C-reactive protein (CRP) levels. However, a primary barrier preventing individuals from engaging in regular physical activity is a lack of time. The purpose of our study was to determine if a high-intensity interval training (HIIT) protocol would be as effective as continuous aerobic endurance training (ET) on resting blood pressure in pre-hypertensive participants. Additionally, this study investigated the effects of HIIT vs. ET on CRP. Twelve pre-hypertensive participants (33.3±6.1 yrs; 3M/9W) participated in 8 weeks of cycle ergometer exercise training. The ET exercised for 30 continuous min/day, 4 days/week at 40% VO2max reserve. The HIIT exercised at a 1:1 work-to-rest for 20 min/day, 3 days/week at 60% peak power. Resting mean arterial pressure and CRP were compared throughout the study. Both groups showed decreases (pHIIT: -8.6 ± 4.8 mmHg) following the 8 weeks. For CRP, there was a significant decrease (p=0.014) as a main effect of time. VO2max increased (pHIIT and ET. These preliminary data suggest HIIT and ET similarly decreased resting blood pressure and increased VO2max.

Effect of PTA on blood pressure, renal plasma flow and renal venous renin activity in renovascular hypertension

International Nuclear Information System (INIS)

Arlart, I.P.; Dewitz, H. von; Rosenthal, J.

1983-01-01

Percutaneous transluminal angioplasty (PTA) is more and more accepted for interventional management of renal artery stenosis in hypertensive patients. This study was carried out to assess the behaviour of arterial blood-pressure, renal plasma flow and renal venous rening activity in renovascular hypertension following catheter dilatation. Using the data the possibility is calculated to predict the effect of PTA on blood pressure preinterventionally. The results demonstrate that a successful employment of PTA depends on a normal contralateral renal plasma flow and a normalization of plasma flow of the poststenotic kidney. Determination of plasma renin activity is only of restricted value. (orig.)

The increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood during vagal afferents stimulation or after angiotensin II infusion

International Nuclear Information System (INIS)

Goraca, A.; Orlowska-Majdak, M.; Traczyk, W.Z.

1996-01-01

It has previously been demonstrated that the cardiodepressant activity is present in the bovine hypothalamic extract and in the fluid incubating the posterior pituitary lobe i n situ . The present study was an attempt to reveal if the cardiodepressant factor and vasopressin were simultaneously released from the pituitary into blood. The samples of venous blood flowing from the sella turcica and, for comparison, from the posterior paw were collected in anesthetized rats. Blood from the sella turcica was collected with a fine cannula inserted into the internal maxillary vein. The concentration of vasopressin in blood plasma was determined by radioimmunoassay and cardiodepressant activity-using a biological test on a spontaneously discharged pacemaker tissue of the right auricle of the right heart atrium. Stimulation of the central ends of the cut vagus nerves or intra-arterial infusion of angiotensin II simultaneously caused an increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood. The cardiodepressant activity and vasopressin concentration was also enhanced to some degree in blood outflowing from the posterior paw. Present results indicate that both vasopressin and the cardiodepressant factor are released into blood from the posterior pituitary lobe. (author). 37 refs, 4 figs

Is Rest Really Rest? Resting State Functional Connectivity during Rest and Motor Task Paradigms.

Science.gov (United States)

Jurkiewicz, Michael T; Crawley, Adrian P; Mikulis, David J

2018-04-18

Numerous studies have identified the default mode network (DMN) within the brain of healthy individuals, which has been attributed to the ongoing mental activity of the brain during the wakeful resting-state. While engaged during specific resting-state fMRI paradigms, it remains unclear as to whether traditional block-design simple movement fMRI experiments significantly influence the default mode network or other areas. Using blood-oxygen level dependent (BOLD) fMRI we characterized the pattern of functional connectivity in healthy subjects during a resting-state paradigm and compared this to the same resting-state analysis performed on motor task data residual time courses after regressing out the task paradigm. Using seed-voxel analysis to define the DMN, the executive control network (ECN), and sensorimotor, auditory and visual networks, the resting-state analysis of the residual time courses demonstrated reduced functional connectivity in the motor network and reduced connectivity between the insula and the ECN compared to the standard resting-state datasets. Overall, performance of simple self-directed motor tasks does little to change the resting-state functional connectivity across the brain, especially in non-motor areas. This would suggest that previously acquired fMRI studies incorporating simple block-design motor tasks could be mined retrospectively for assessment of the resting-state connectivity.

Relationship between retinal blood flow and arterial oxygen.

Science.gov (United States)

Cheng, Richard W; Yusof, Firdaus; Tsui, Edmund; Jong, Monica; Duffin, James; Flanagan, John G; Fisher, Joseph A; Hudson, Chris

2016-02-01

Vascular reactivity, the response of the vessels to a vasoactive stimulus such as hypoxia and hyperoxia, can be used to assess the vascular range of adjustment in which the vessels are able to compensate for changes in PO2. Previous studies in the retina have not accurately quantified retinal vascular responses and precisely targeted multiple PaO2 stimuli at the same time as controlling the level of carbon dioxide, thus precluding them from modelling the relationship between retinal blood flow and oxygen. The present study modelled the relationship between retinal blood flow and PaO2, showing them to be a combined linear and hyperbolic function. This model demonstrates that the resting tonus of the vessels is at the mid-point and that they have great vascular range of adjustment, compensating for decreases in oxygen above a PETCO2 of 32-37 mmHg but being limited below this threshold. Retinal blood flow (RBF) increases in response to a reduction in oxygen (hypoxia) but decreases in response to increased oxygen (hyperoxia). However, the relationship between blood flow and the arterial partial pressure of oxygen has not been quantified and modelled in the retina, particularly in the vascular reserve and resting tonus of the vessels. The present study aimed to determine the limitations of the retinal vasculature by modelling the relationship between RBF and oxygen. Retinal vascular responses were measured in 13 subjects for eight different blood gas conditions, with the end-tidal partial pressure of oxygen (PETCO2) ranging from 40-500 mmHg. Retinal vascular response measurements were repeated twice; using the Canon laser blood flowmeter (Canon Inc., Tokyo, Japan) during the first visit and using Doppler spectral domain optical coherence tomography during the second visit. We determined that the relationship between RBF and PaO2 can be modelled as a combination of hyperbolic and linear functions. We concluded that RBF compensated for decreases in arterial oxygen content

Pathophysiology of spontaneous venous gas embolism

Science.gov (United States)

Lambertsen, C. J.; Albertine, K. H.; Pisarello, J. B.; Flores, N. D.

1991-01-01

The use of controllable degrees and durations of continuous isobaric counterdiffusion venous gas embolism to investigate effects of venous gas embolism upon blood, cardiovascular, and respiratory gas exchange function, as well as pathological effects upon the lung and its microcirculation is discussed. Use of N2O/He counterdiffusion permitted performance of the pathophysiologic and pulmonary microstructural effects at one ATA without hyperbaric or hypobaric exposures.

Absence of resting cardiovascular dysfunction in middle-aged endurance-trained athletes with exaggerated exercise blood pressure responses.

Science.gov (United States)

Currie, Katharine D; Sless, Ryan T; Notarius, Catherine F; Thomas, Scott G; Goodman, Jack M

2017-08-01

Untrained individuals with exaggerated blood pressure (EBP) responses to graded exercise testing are characterized as having resting dysfunction of the sympathetic and cardiovascular systems. The purpose of this study was to determine the resting cardiovascular state of endurance-trained individuals with EBP through a comparison of normotensive athletes with and without EBP. EBP was defined as a maximal systolic blood pressure (SBP) at least 190 mmHg and at least 210 mmHg for women and men respectively, in response to a graded exercise test. Twenty-two life-long endurance-trained athletes (56 ± 5 years, 16 men) with EBP (EBP+) and 11 age and sex-matched athletes (55 ± 5 years, eight men) without EBP (EBP-) participated in the study. Sympathetic reactivity was assessed using BP responses to a cold pressor test, isometric handgrip exercise, and postexercise muscle ischemia. Resting left ventricular structure and function was assessed using two-dimensional echocardiography, whereas central arterial stiffness was assessed using carotid-to-femoral pulse wave velocity. Calf vascular conductance was measured at rest and peak postexercise using strain-gauge plethysmography. All sympathetic reactivity, left ventricular, and arterial stiffness indices were similar between groups. There was no between-group difference in resting vascular conductance, whereas peak vascular conductance was higher in EBP+ relative to EBP- (1.81 ± 0.65 vs. 1.45 ± 0.32 ml/100 ml/min/mmHg, P < 0.05). Findings from this study suggest that athletes with EBP do not display the resting cardiovascular state typically observed in untrained individuals with EBP. This response in athletes, therefore, is likely a compensatory mechanism to satisfy peripheral blood-flow demands rather than indicative of latent dysfunction.

Comparison of renal venous blood flow between normal pregnant women and non-pregnant women by colour and duplex doppler sonography

International Nuclear Information System (INIS)

Khan, S.; Butt, R.W.; Masoud, R; Umar, M.; Shakil, U.

2012-01-01

To investigate whether normal pregnancy has a significant effect on intrarenal venous blood flow and to assess whether the physiological maternal pyelocaliectasis causes a measurable change in venous impedance indices in pregnant women. Study Design: Cross sectional comparative study. Place and duration of study: Radiology Departments, KRL Hospital Islamabad and Combined Military Hospital Lahore from Jan 2010 to Jul 2010 Patients and Methods: A total of 50 normal pregnant women in their second and third trimester and 50 controls, i.e. normal non-pregnant married healthy women of childbearing age were included in the study. Confounding variables were controlled by excluding subjects having recent or previous renal calculi, pathological renal conditions or congenital renal anomalies or generalized disorders affecting haemodynamics ruled out by history, clinical examination and ultrasound examination in both pregnant and non-pregnant women. Results: After grading the degree of hydronephrosis, venous impedance index was obtained from the interlobar veins. Overall the collecting system dilatation was present in 60 % of 50 right kidneys and 42 % of 50 left kidneys in the pregnant women. The venous impedance indices were significantly lower in 50 pregnant women than the values in non-pregnant subjects (p< 0.001 for the right and the left kidney). The overall difference in venous impedance indices between right and left kidneys was not significant in pregnant women (p = 0.11). There was an inverse correlation between the grade of pelvicalyceal dilatation and the venous impedance indices in both kidneys in 50 pregnant women. Conclusion: Normal pregnancy causes dilatation of the pelvicalyceal system and significant reduction in renal venous impedance index values in second and third trimesters. Therefore one should be careful in interpretation of an abnormally reduced venous impedance index and hydronephrosis as a sign of pathological ureteral obstruction in pregnant women

Quantitative assessment of limb blood flow using Tc-99m labeled red blood cells

International Nuclear Information System (INIS)

Itoh, Kazuo; Shougase, Takashi; Kawamura, Naoyuki; Tsukamoto, Eriko; Nakada, Kunihiro; Sakuma, Makoto; Furudate, Masayori

1987-01-01

A quantitative assessment of limb blood flow using a non-diffusible radioindicator, Tc-99m labeled red blood cells, was reported. This was an application of venous occlusion plethysmography using radionuclide which was originally proposed by M. Fukuoka et al. The peripheral blood flow (mean ± s.e.) of 30 legs in a normal control group was 1.87 ± 0.08 ml/100 ml/min. In heart diseases (46 legs), it was 1.49 ± 0.13 ml/100 ml/min. The limb blood flow between a control group and heart diseases was statistically significant (p < 0.01) in the t-test. The peripheral blood flow at rest between diseased legs and normal legs in occlusive arterial disorders was also statistically significant (p < 0.01) in a paired t-test. RAVOP was done after the completion of objective studies such as radionuclide angiography or ventriculography. Technique and calculation of a blood flow were very easy and simple. RAVOP study which was originally proposed by Fukuoka et al. was reappraised to be hopeful for quantitative measurement of limb blood flow as a non-invasive technique using Tc-99m labeled red blood cells. (author)

Autologous blood sequestration using a double venous reservoir bypass circuit and polymerized hemoglobin prime.

Science.gov (United States)

Neragi-Miandoab, Siyamek; Guerrero, J Luis; Vlahakes, Gus J

2002-01-01

Cardiac surgery often necessitates transfusion of homologous blood. Hemoglobin based oxygen carrying solutions (HBOCs) transport oxygen, suggesting use in cardiopulmonary bypass. HBOC was used in a novel oxygenator double-reservoir circuit that permits acute sequestration of a portion of the autologous blood volume during bypass. Two groups of seven mongrel dogs each were studied in an experimental bypass model using global myocardial ischemia and cardioplegia protection: HBOC group, initial venous return drained to a separate reservoir and hypothermic bypass was conducted with HBOC containing perfusate in a second bypass reservoir; Control group, crystalloid prime in a conventional circuit. Hemodynamics and metabolic and hematologic parameters were measured before and 60 min after aortic clamp removal and reinfusion of sequestered autologous blood. Blood gases, base excess, hematocrit, total hemoglobin, and platelet counts were measured. In the HBOC group, metabolic acidosis did not occur, and ventricular function was preserved. Net conservation of platelets was noted at study conclusion: control 33+/-13 x 10(3) per mm3 versus HBOC 48+/-13 x 10(3), p conservation of the platelet mass occurs, a portion of which is not exposed to the deleterious effects of hypothermia and cardiopulmonary bypass.

Computed tomographic manifestations of abdominal and pelvic venous collaterals

International Nuclear Information System (INIS)

Pagani, J.J.; Thomas, J.L.; Bernardino, M.E.

1982-01-01

Obstruction of blood flow through the inferior vena cava and portal vein may produce venous collaterals. These include the paravertebral venous system and its communications with the ascending lumbar veins and azygous/hemiazygous system; gonadal, periureteric, and other retroperitoneal veins; abdominal wall veins; hemorrhoidal venous plexus; and the portal venous system. The anatomic location of these vessels is discussed. Computed tomography demonstrates them as round or tubular structures that are isodens when compared with other venous structures following contrast material administration. Techniques of examination and methods of differentiation of these vascular structures from other abnormalities, especially lymphadenopathy, are discussed

[Venous thrombosis associated with central venous catheter use in patients with cancer].

Science.gov (United States)

Iglesias Rey, Leticia; Fernández Pérez, Isaura; Barbagelata López, Cristina; Rivera Gallego, Alberto

2015-01-01

The use of central venous catheters for various applications (administration of chemotherapy, blood products and others) in patients with cancer is increasingly frequent. The association between thrombosis and catheter use has been fully established but aspects such as its causes, diagnosis, prophylaxis and treatment have not. We describe a case of thrombosis in a patient with cancer treated with chemotherapy who carried a central venous catheter. We also perform a review of the risk factors, the role of the prophylaxis and the treatment. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Venous and Arterial Thromboses: Two Sides of the Same Coin?

Science.gov (United States)

Lippi, Giuseppe; Favaloro, Emmanuel J

2018-04-01

Arterial and venous thromboses are sustained by development of intraluminal thrombi, respectively, within the venous and arterial systems. The composition and structure of arterial and venous thrombi have been historically considered as being very different. Arterial thrombi (conventionally defined as "white") have been traditionally proposed to be composed mainly of fibrin and platelet aggregates, whilst venous thrombi (conventionally defined as "red") have been proposed as mostly being enriched in fibrin and erythrocytes. This archaic dichotomy seems ever more questionable, since it barely reflects the pathophysiology of thrombus formation in vivo. Both types of thrombi are actually composed of a complex fibrin network but, importantly, also contain essentially the same blood-borne cells (i.e., red blood cells, leukocytes, and platelets), and it is only the relative content of these individual elements that differ between venous and arterial clots or, otherwise, between thrombi generated under different conditions of blood flow and shear stress. Convincing evidence now suggests that either white or red intracoronary thrombi may be present in patients with myocardial infarction and, even more importantly, red thrombi may be more prone to distal embolization during percutaneous coronary intervention than those with lower content of erythrocytes. Conversely, it is now accepted that components traditionally considered to be involved "only" in arterial thrombosis are also represented in venous thrombosis. Thus, platelets comprise important components of venous clots, although they may be present in lower amounts here than in arterial thrombi, and von Willebrand factor is also represented in both arterial and venous thrombi. Of importance, such evidence thus supports the concept that adjunctive treatment normally associated to prevention of arterial thrombosis (e.g., aspirin) may have a role also in prevention and treatment of venous thrombosis. Thieme Medical

Diurnal variations in lower leg subcutaneous blood flow rate in patients with chronic venous leg ulcers

DEFF Research Database (Denmark)

Sindrup, J H; Kastrup, J; Kristensen, J K

1991-01-01

The blood flow rate in subcutaneous adipose tissue was measured on the lower legs of 11 patients with chronic lower-leg venous insufficiency and ulceration and in eight age-matched control subjects for 12-20 h, under ambulatory conditions, using the 133Xe wash-out technique with portable Cadmium...... telluride (CdTe(Cl)) detectors. In both groups, the change from an upright to a supine position at the beginning of the night period elicited an instantaneous increment in the blood flow rate of 30-40% with a decrease in the central and local postural sympathetic vasoconstrictor activity. After...... approximately 1 h of sleep, a considerable increase in blood flow rate was seen in both patient and control groups which persisted for nearly 100 min. In the patient group, the mean increase was 137% compared to a mean increase of 68% in the control group (P less than 0.01). The blood flow then returned...

Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood

Directory of Open Access Journals (Sweden)

H.A. Hussein

2013-01-01

Full Text Available The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10, at RT of about 22-25 ºC (Group II, n = 10 and in an incubator adjusted to 37 ºC (Group III, n = 10 for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0, there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (p<0.05, the pH value of refrigerated blood samples exhibited insignificant changes during the study (p<0.05. Mean values of pCO2 showed a significant increase in Group I and Group III after 1 h then a progressive decrease after 12 h in all Groups. Mean pO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (p<0.05. In general, base excess decreased significantly for all the groups during the study especially in Groups II and III. In comparison with baseline values, in all groups, bicarbonate (HCO3 increased between 1 h and 6 h (p<0.05, and later decreased at the end of the study (p<0.05. In conclusion, status of acid-base indices of the samples stored at refrigerator and RT were found within normal reference range and it may be of clinical diagnostic use for up to 6 h.

Arterial versus venous lactate: a measure of sepsis in children.

Science.gov (United States)

Samaraweera, Sahan Asela; Gibbons, Berwyck; Gour, Anami; Sedgwick, Philip

2017-08-01

This study assessed the agreement between arterial and venous blood lactate and pH levels in children with sepsis. This retrospective, three-year study involved 60 PICU patients, with data collected from electronic or paper patient records. The inclusion criteria comprised of children (≤17 years old) with sepsis and those who had a venous blood gas taken first with an arterial blood gas taken after within one hour. The lactate and pH values measured through each method were analysed. There is close agreement between venous and arterial lactate up to 2 mmol/L. As this value increases, this agreement becomes poor. The limits of agreement (LOA) are too large (±1.90 mmol/L) to allow venous and arterial lactate to be used interchangeably. The mean difference and LOA between both methods would be much smaller if derived using lactate values under 2.0 mmol/L. There is close agreement between arterial and venous pH (MD = -0.056, LOA ± 0.121). However, due to extreme variations in pH readings during sepsis, pH alone is an inadequate marker. A venous lactate ≤2 mmol/L can be used as a surrogate for arterial lactate during early management of sepsis in children. However, if the value exceeds 2 mmol/L, an arterial sample must confirm the venous result. What is known: • In children with septic shock, a blood gas is an important test to show the presence of acidosis and high lactic acid. Hyperlactataemia on admission is an early predictor of outcome and is associated with a greater mortality risk. • An arterial sample is the standard for lactate measurement, however getting a sample may be challenging in the emergency department or a general paediatric ward. Venous samples are quicker and easier to obtain. Adult studies generally advise caution in replacing venous lactate values for the arterial standard, whilst paediatric studies are limited in this area. What is new: • This is the first study assessing the agreement between arterial and peripheral venous

The increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood during vagal afferents stimulation or after angiotensin II infusion

Energy Technology Data Exchange (ETDEWEB)

Goraca, A.; Orlowska-Majdak, M.; Traczyk, W.Z. [Akademia Medyczna, Lodz (Poland). Katedra Fizjologii

1996-12-31

It has previously been demonstrated that the cardiodepressant activity is present in the bovine hypothalamic extract and in the fluid incubating the posterior pituitary lobe {sup i}n situ{sup .} The present study was an attempt to reveal if the cardiodepressant factor and vasopressin were simultaneously released from the pituitary into blood. The samples of venous blood flowing from the sella turcica and, for comparison, from the posterior paw were collected in anesthetized rats. Blood from the sella turcica was collected with a fine cannula inserted into the internal maxillary vein. The concentration of vasopressin in blood plasma was determined by radioimmunoassay and cardiodepressant activity-using a biological test on a spontaneously discharged pacemaker tissue of the right auricle of the right heart atrium. Stimulation of the central ends of the cut vagus nerves or intra-arterial infusion of angiotensin II simultaneously caused an increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood. The cardiodepressant activity and vasopressin concentration was also enhanced to some degree in blood outflowing from the posterior paw. Present results indicate that both vasopressin and the cardiodepressant factor are released into blood from the posterior pituitary lobe. (author). 37 refs, 4 figs.

Measuring vascular reactivity with resting-state blood oxygenation level-dependent (BOLD) signal fluctuations: A potential alternative to the breath-holding challenge?

Science.gov (United States)

Jahanian, Hesamoddin; Christen, Thomas; Moseley, Michael E; Pajewski, Nicholas M; Wright, Clinton B; Tamura, Manjula K; Zaharchuk, Greg

2017-07-01

Measurement of the ability of blood vessels to dilate and constrict, known as vascular reactivity, is often performed with breath-holding tasks that transiently raise arterial blood carbon dioxide (P a CO 2 ) levels. However, following the proper commands for a breath-holding experiment may be difficult or impossible for many patients. In this study, we evaluated two approaches for obtaining vascular reactivity information using blood oxygenation level-dependent signal fluctuations obtained from resting-state functional magnetic resonance imaging data: physiological fluctuation regression and coefficient of variation of the resting-state functional magnetic resonance imaging signal. We studied a cohort of 28 older adults (69 ± 7 years) and found that six of them (21%) could not perform the breath-holding protocol, based on an objective comparison with an idealized respiratory waveform. In the subjects that could comply, we found a strong linear correlation between data extracted from spontaneous resting-state functional magnetic resonance imaging signal fluctuations and the blood oxygenation level-dependent percentage signal change during breath-holding challenge ( R 2  = 0.57 and 0.61 for resting-state physiological fluctuation regression and resting-state coefficient of variation methods, respectively). This technique may eliminate the need for subject cooperation, thus allowing the evaluation of vascular reactivity in a wider range of clinical and research conditions in which it may otherwise be impractical.

Analysis of the dynamics of venous blood flow in the context of lower limb temperature distribution and tissue composition in the elderly.

Science.gov (United States)

Skomudek, Aleksandra; Gilowska, Iwona; Jasiński, Ryszard; Rożek-Piechura, Krystyna

2017-01-01

The elderly are particularly vulnerable to degenerative diseases, such as circulatory and respiratory system and vascular system diseases. The objective of this study was therefore to evaluate the distribution of temperature and the dynamics of venous blood flow in the lower limbs (LLs) and to assess the interdependence of these parameters in terms of the somatic components in males and females participating in activities at the University of the Third Age. The study included 60 females (mean age 67.4 years) and 40 males (mean age 67.5 years). A body composition assessment was performed using the bioimpedance technique - Tanita BC-418MA. The following parameters were examined: fat%, fat mass, fat-free mass, and total body water. The minimal, maximal, and mean temperature values and their distributions were examined using infrared thermographic camera VarioCAM Head. Measurements of the venous refilling time and the work of the LL venous pump were examined using a Rheo Dopplex II PPG. In males, the mean value of the right LL temperature was 30.58 and the mean value of the left LL was 30.28; the P -value was 0.805769. In females, the mean value of the right LL temperature was 29.58 and the mean value of the left limb was 29.52; the P -value was 0.864773. In males, the right limb blood flow was 34.17 and the left limb blood flow was 34.67; the P -value was 0.359137. In females, the right limb blood flow was 26.89 and the left limb blood flow was 26.09; the P -value was 0.796348. Research results showed that the temperature distribution and the dynamics of blood flow are not significantly different between the right and left extremities in both males and females. However, significant temperature differences were found between the gender groups. Significantly higher temperature values in both the right and left extremities were recorded in males than in females.

Mean 24-hours sympathetic nervous system activity decreases during head-down tilted bed rest but not during microgravity

Science.gov (United States)

Christensen, Nj; Heer, M.; Ivanova, K.; Norsk, P.

Sympathetic nervous system activity is closely related to gravitational stress in ground based experiments. Thus a high activity is present in the standing-up position and a very low activity is observed during acute head-out water immersion. Adjustments in sympathetic activity are necessary to maintain a constant blood pressure during variations in venous return. Head-down tilted bed rest is applied as a model to simulate changes observed during microgravity. The aim of the present study was to test the hypothesis that mean 24-hours sympathetic activity was low and similar during space flight and in ground based observation obtained during long-term head-down tilted bed rest. Forearm venous plasma noradrenaline was measured by a radioenzymatic technique as an index of muscle sympathetic activity and thrombocyte noradrenaline and adrenaline were measured as indices of mean 24-hours sympathoadrenal activity. Previous results have indicated that thrombocyte noradrenaline level has a half-time of 2 days. Thus to reflect sympathetic activity during a specific experiment the study period must last for at least 6 days and a sample must be obtained within 12 hours after the experiment has ended. Ten normal healthy subjects were studied before and during a 14 days head-down tilted bed rest as well as during an ambulatory study period of a similar length. The whole experiment was repeated while the subjects were on a low calorie diet. Thrombocyte noradrenaline levels were studied in 4 cosmonauts before and within 12 hours after landing after more than 7 days in flight. Thrombocyte noradrenaline decreased markedly during the head-down tilted bed rest (pdifferent in cosmonauts and in subjects participating in the head down tilted bed rest study (170± 29% (Mean± SEM) vs. 57± 7%, respectively; presponse to combined effects of a reduced plasma volume and an increased vascular capacity in flight.

Venous thromboembolism and arterial complications.

Science.gov (United States)

Prandoni, Paolo; Piovella, Chiara; Pesavento, Raffaele

2012-04-01

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, smoking, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Pediatric central venous access devices: nursing interventions

Directory of Open Access Journals (Sweden)

Duffy EA

2017-05-01

Full Text Available Elizabeth A Duffy, Kathryn N Nelson Department of Health Behavior and Biological Sciences, The University of Michigan School of Nursing, Ann Arbor, MI, USA Abstract: A central venous catheter (CVC is an indwelling catheter that provides permanent or temporary stable venous access for both acute and chronically ill pediatric patients. These catheters provide stable venous access that can be used for a variety of medical purposes including drawing blood, hemodynamic monitoring, infusion of intravenous medications, infusion of intravenous fluids, chemotherapy, blood products, and parenteral nutrition. Each day, nurses access and care for CVCs in infants, children, and adolescents; the precision of this care can prevent life-threatening complications. The purpose of this review and the case study is to highlight the importance and components of evidence-based nursing practice in pediatric CVC care. A historical perspective of CVC care is provided in conjunction with current national initiatives to improve patient outcomes for children with CVCs. Infection prevention, clinical practice guidelines, quality improvement, and evidence-based care bundles are discussed. Keywords: pediatric nursing, central venous catheters, central line-associated bloodstream infection, care bundles, pediatric case study 

Resting quantitative cerebral blood flow in schizophrenia measured by pulsed arterial spin labeling perfusion MRI

OpenAIRE

Pinkham, Amy; Loughead, James; Ruparel, Kosha; Wu, Wen-Chau; Overton, Eve; Gur, Raquel; Gur, Ruben

2011-01-01

Arterial spin labeling imaging (ASL) perfusion MRI is a relatively novel technique that can allow for quantitative measurement of cerebral blood flow (CBF) by using magnetically labeled arterial blood water as an endogenous tracer. Available data on resting CBF in schizophrenia primarily comes from invasive and expensive nuclear medicine techniques that are often limited to small samples and yield mixed results. The noninvasive nature of ASL offers promise for larger-scale studies. The utilit...

Effects of Long Duration Spaceflight on Venous and Arterial Compliance in Astronants

Science.gov (United States)

Platts, Steven; Ribeiro, L. Christine

2014-01-01

noninvasive measures of venous and arterial compliance are altered by long-duration spaceflight exposure in ISS astronauts and whether these changes are related to the development of the VIIP syndrome. (Flight) 2. To determine whether previous spaceflight experience predispose astronauts to lower venous compliance and/or the development of the VIIP syndrome. (Ground + Flight) 3. To use a 14-day, 6deg head-down-tilt bed rest as a model of spaceflight, to evaluate the effect of aging on vascular compliance using a subject population similar to younger (25-35 yr) and older (45-55 yr) astronaut cohorts. (Bed Rest) 4. To determine what factors contribute to lower venous compliance and/or the development of the VIIP syndrome in astronauts. (Data Mining) 3. Earth Applications This research may inform the mechanisms that regulate blood/fluid flow in and out of the brain in the head and neck. This information may help with understanding of the mechanisms behind idiopathic intracranial hypertension. 4. Link to NASA Taskbook Entry Not Yet Available

Resting state cerebral blood flow with arterial spin labeling MRI in developing human brains.

Science.gov (United States)

Liu, Feng; Duan, Yunsuo; Peterson, Bradley S; Asllani, Iris; Zelaya, Fernando; Lythgoe, David; Kangarlu, Alayar

2018-07-01

The development of brain circuits is coupled with changes in neurovascular coupling, which refers to the close relationship between neural activity and cerebral blood flow (CBF). Studying the characteristics of CBF during resting state in developing brain can be a complementary way to understand the functional connectivity of the developing brain. Arterial spin labeling (ASL), as a noninvasive MR technique, is particularly attractive for studying cerebral perfusion in children and even newborns. We have collected pulsed ASL data in resting state for 47 healthy subjects from young children to adolescence (aged from 6 to 20 years old). In addition to studying the developmental change of static CBF maps during resting state, we also analyzed the CBF time series to reveal the dynamic characteristics of CBF in differing age groups. We used the seed-based correlation analysis to examine the temporal relationship of CBF time series between the selected ROIs and other brain regions. We have shown the developmental patterns in both static CBF maps and dynamic characteristics of CBF. While higher CBF of default mode network (DMN) in all age groups supports that DMN is the prominent active network during the resting state, the CBF connectivity patterns of some typical resting state networks show distinct patterns of metabolic activity during the resting state in the developing brains. Copyright © 2018 European Paediatric Neurology Society. All rights reserved.

Direct Open Venous Drainage: An Alternative Choice for Flap Congestion Salvage.

Science.gov (United States)

Park, Su Han; Choi, Woo Young; Son, Kyung Min; Cheon, Ji Seon; Yang, Jeong Yeol

2015-12-01

In this report, we present a scalp defect reconstruction with lateral arm free flap. We highlight the difficulty in obtaining a recipient vein and the venous drainage managed through an open end of the donor vein. A 52-year-old woman presented with a pressure sore on the left scalp. A lateral arm free flap was transferred to cover this 8×6 cm defect. The arterial anastomosis was successful, but no recipient vein could be identified within the wound bed. Instead, we used a donor venous end for the direct open venous drainage. In order to keep this exposed venous end patent, we applied heparin-soaked gauze dressing to the wound. Also, the vein end was mechanically dilated and irrigated with heparin solution at two hour intervals. Along with fluid management and blood transfusion, this management was continued for the five days after the operation. The flap survived well without any complication. Through this case, we were able to demonstrate that venous congestion can be avoided by drainage of the venous blood through an open vessel without the use of leeches.

Magnetic resonance measurements of azygos and portal venous blood flow under fasting and postprandial conditions in healthy controls and cirrhotics

International Nuclear Information System (INIS)

Takamura, Naoko

2001-01-01

Using MR velocity mapping, we studied measurements azygos (A) and portal venous blood flow (P) under fasting and postprandial conditions in 7 healthy controls (C) and 10 cirrhotics (LC). Fasting A in LC was higher than that in C. Fasting P in C was higher than that in LC. Variability of repeated measuring A and P was low in C and LC. A postprandial increase of A in LC was higher than that in C. Fasting A/P ratio in LC was higher than that in C. Our results suggest that MR velocity mapping is expected as the reproducible method for monitoring the hemodynamic change in the azygos and portal venous system. (author)

Scintigraphy and venous sampling in endocrine adrenal diseases. Clinical results in 85 patients

International Nuclear Information System (INIS)

Feltrin, G.P.; Maffessanti, M.; Miotto, D.; Mantero, F.; Macri, G.; Romani, S.

1979-01-01

The results obtained by adrenal scanning and venous sampling in 85 patients affected by various forms of adrenal pathology are reported and discussed. Pheochromocytoma rarely needs venous catheterization and blood sampling, since arteriography is almost always capable to visualize it. Scintigraphy alone is generally accurate enough to distinguish between bilateral hyperplasia and tumors in Cushing's and adrenogenital syndromes (100% of personal observations); only a tumoral situation benefits by venous catheterization. Blood samples and venography must be preceded by scintigraphy in Conn's syndrome

Epidural venous stasis in spinal stenosis

International Nuclear Information System (INIS)

Kaiser, M.C.; Capesius, P.; Poos, D.; Gratia, G.; Roilgen, A.; Sandt, G.

1984-01-01

Computed tomography permits reliable demonstration of the spinal canal and its contents. Measurements of the sagittal diameter of the bony canal do not take into consideration size, shape and state of intraspinal soft tissue structures, i.e. the thecal sac and its own contents, epidural fat and blood circulation pattern. Three particularly illustrative cases were selected in which obvious epidural venous engorgement was visualized in association with spinal stenosis. The authors think that epidural venous stasis occuring in segmental spinal stenosis is a CT sign of clinically significant narrowing of the neural canal. Accurate recognition of the type of lumbar stenosis together with epidural blood flow alterations permits a better understanding of the existing lesions. Thus, a more precise and specific surgical approach is possible. (orig.)

The difference between fingerstick and venous hemoglobin and hematocrit varies by sex and iron stores.

Science.gov (United States)

Cable, Ritchard G; Steele, Whitney R; Melmed, Russell S; Johnson, Bryce; Mast, Alan E; Carey, Patricia M; Kiss, Joseph E; Kleinman, Steven H; Wright, David J

2012-05-01

Fingerstick blood samples are used to estimate donor venous hemoglobin (Hb). Fingerstick Hb or hematocrit (Hct) was determined routinely for 2425 selected donors at six blood centers, along with venous Hb. Using sex and measures of iron status including absent iron stores (AIS; ferritin < 12 ng/mL), linear regression models were developed to predict venous Hb from fingerstick. Across all subjects, fingerstick Hb was higher than venous Hb in the higher part of the clinical range, but lower in the lower part of the range. The relationship varied by sex and iron status. Across centers, a female donor had on average a venous Hb result 0.5 to 0.8 g/dL lower than a male donor with the same fingerstick Hb and iron status. Similarly, a donor with AIS had on average a venous Hb result 0.3 to 1.1 g/dL lower than an iron-replete donor with the same fingerstick value and sex. An iron-replete male donor with a fingerstick result at the cutoff (Hb 12.5 g/dL) had an acceptable expected venous Hb (12.8 to 13.8 g/dL). A female donor with AIS with a fingerstick result at the cutoff had an expected venous Hb below 12.5 g/dL (11.7 to 12.4 g/dL). Of females with AIS, 40.2% donated blood when their venous Hb was less than 12.5 g/dL. Fingerstick is considered a useful estimator of venous Hb. However, in some donor groups, particularly female donors with AIS, fingerstick overestimates venous Hb at the donation cutoff. This significant limitation should be considered in setting donor fingerstick Hb or Hct requirements. © 2011 American Association of Blood Banks.

Nitrite and S-Nitrosohemoglobin Exchange Across the Human Cerebral and Femoral Circulation: Relationship to Basal and Exercise Blood Flow Responses to Hypoxia.

Science.gov (United States)

Bailey, Damian M; Rasmussen, Peter; Overgaard, Morten; Evans, Kevin A; Bohm, Aske M; Seifert, Thomas; Brassard, Patrice; Zaar, Morten; Nielsen, Henning B; Raven, Peter B; Secher, Niels H

2017-01-10

The mechanisms underlying red blood cell (RBC)-mediated hypoxic vasodilation remain controversial, with separate roles for nitrite () and S-nitrosohemoglobin (SNO-Hb) widely contested given their ability to transduce nitric oxide bioactivity within the microcirculation. To establish their relative contribution in vivo, we quantified arterial-venous concentration gradients across the human cerebral and femoral circulation at rest and during exercise, an ideal model system characterized by physiological extremes of O 2 tension and blood flow. Ten healthy participants (5 men, 5 women) aged 24±4 (mean±SD) years old were randomly assigned to a normoxic (21% O 2 ) and hypoxic (10% O 2 ) trial with measurements performed at rest and after 30 minutes of cycling at 70% of maximal power output in hypoxia and equivalent relative and absolute intensities in normoxia. Blood was sampled simultaneously from the brachial artery and internal jugular and femoral veins with plasma and RBC nitric oxide metabolites measured by tri-iodide reductive chemiluminescence. Blood flow was determined by transcranial Doppler ultrasound (cerebral blood flow) and constant infusion thermodilution (femoral blood flow) with net exchange calculated via the Fick principle. Hypoxia was associated with a mild increase in both cerebral blood flow and femoral blood flow (Pflow during exercise (Pvenous; Parterial; P0.05). These findings suggest that hypoxia and, to a far greater extent, exercise independently promote arterial-venous delivery gradients of intravascular nitric oxide, with deoxyhemoglobin-mediated reduction identified as the dominant mechanism underlying hypoxic vasodilation. © 2016 American Heart Association, Inc.

Sources of variability of resting cerebral blood flow in healthy subjects

DEFF Research Database (Denmark)

Henriksen, Otto Mølby; Kruuse, Christina Rostrup; Olesen, Jes

2013-01-01

Measurements of cerebral blood flow (CBF) show large variability among healthy subjects. The aim of the present study was to investigate the relative effect of established factors influencing CBF on the variability of resting CBF. We retrospectively analyzed spontaneous variability in 430 CBF...... measurements acquired in 152 healthy, young subjects using (133)Xe single-photon emission computed tomography. Cerebral blood flow was correlated positively with both end-tidal expiratory PCO2 (PETCO2) and female gender and inversely with hematocrit (Hct). Between- and within-subject CO2 reactivity...... when Hct was also accounted for. The present study confirms large between-subject variability in CBF measurements and that gender, Hct, and PETCO2 explain only a small part of this variability. This implies that a large fraction of CBF variability may be due to unknown factors such as differences...

The investigation of complete blood counting parameters in deep venous thrombosis

Directory of Open Access Journals (Sweden)

Ahmet Çalışkan

2014-03-01

Full Text Available Objective: The role of inflammation in the deep venous thrombosis (DVT process has been explained in various studies. Hence, the role of inflammatory markers in this illness has been researched previouslyin the literature. Recent years, such as parameters, neutrophil lymphocyte ratio (NLR and platelet lymphocyte ratio (PLR, among complete blood count have been frequently started to use as an expression of inflammatory marker. In the current study, the relation between complete blood count parameters and DVT was investigated. Methods: 50 patients admitted to our clinic with the diagnosis of acute DVT (28 female, 22 male were included in the study. The patients were diagnosed by clinical symptoms and Doppler USG. Patients with additional illness that can form an inflammatory response were excluded. 30 healthy volunteers were included as a control group. Routine complete blood counts of these patients were examined retrospectively. Routine complete blood counts and nonselective inflammatory markers, red cell distribution width (RDW, white cells (WBC, NLR, and PLR measurements were examined statistically. Results: The mean age of patients included in study was 46.2±14.2 and 53% of them were female. When the groups were examined in terms of hematological parameters, lymphocyte (2.6±0.8 and 2.1±0.7, p=0.003 and platelet (322±144 and 264±66, p=0.042 values were detected to be higher. Hemoglobin (13.2±2.0 and 14.6±1.5, p=0.002 and hematocrit (38.7±5.1 and 42.8±6.9, p<0.001 values were detected to be less while the WBC, neutrophil, NLR, RDW and PLR were similar. Regarding the two groups with and without anticoagulant therapy, in the DVT group, there were no significant differences detected in terms of age, gender, and hematological parameters. Conclusion: In this study, there were no significant differences between healthy volunteers blood count parameters of patients taken into consideration with pure DVT. There is no significant change shown.

Venous or arterial blood components trigger more brain swelling, tissue death after acute subdural hematoma compared to elderly atrophic brain with subdural effusion (SDE) model rats.

Science.gov (United States)

Wajima, Daisuke; Sato, Fumiya; Kawamura, Kenya; Sugiura, Keisuke; Nakagawa, Ichiro; Motoyama, Yasushi; Park, Young-Soo; Nakase, Hiroyuki

2017-09-01

Acute subdural hematoma (ASDH) is a frequent complication of severe head injury, whose secondary ischemic lesions are often responsible for the severity of the disease. We focused on the differences of secondary ischemic lesions caused by the components, 0.4ml venous- or arterial-blood, or saline, infused in the subdural space, evaluating the differences in vivo model, using rats. The saline infused rats are made for elderly atrophic brain with subdural effusion (SDE) model. Our data showed that subdural blood, both venous- and arterial-blood, aggravate brain edema and lesion development more than SDE. This study is the first study, in which different fluids in rats' subdural space, ASDH or SDE are compared with the extension of early and delayed brain damage by measuring brain edema and histological lesion volume. Blood constituents started to affect the degree of ischemia underneath the subdural hemorrhage, leading to more pronounced breakdown of the blood-brain barrier and brain damage. This indicates that further strategies to treat blood-dependent effects more efficiently are in view for patients with ASDH. Copyright © 2017 Elsevier B.V. All rights reserved.

Altered cerebral blood flow velocity features in fibromyalgia patients in resting-state conditions.

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Rodríguez, Alejandro; Tembl, José; Mesa-Gresa, Patricia; Muñoz, Miguel Ángel; Montoya, Pedro; Rey, Beatriz

2017-01-01

The aim of this study is to characterize in resting-state conditions the cerebral blood flow velocity (CBFV) signals of fibromyalgia patients. The anterior and middle cerebral arteries of both hemispheres from 15 women with fibromyalgia and 15 healthy women were monitored using Transcranial Doppler (TCD) during a 5-minute eyes-closed resting period. Several signal processing methods based on time, information theory, frequency and time-frequency analyses were used in order to extract different features to characterize the CBFV signals in the different vessels. Main results indicated that, in comparison with control subjects, fibromyalgia patients showed a higher complexity of the envelope CBFV and a different distribution of the power spectral density. In addition, it has been observed that complexity and spectral features show correlations with clinical pain parameters and emotional factors. The characterization features were used in a lineal model to discriminate between fibromyalgia patients and healthy controls, providing a high accuracy. These findings indicate that CBFV signals, specifically their complexity and spectral characteristics, contain information that may be relevant for the assessment of fibromyalgia patients in resting-state conditions.

The role of stress hormones in the relationship between resting blood pressure and coagulation activity.

Science.gov (United States)

Wirtz, Petra H; Ehlert, Ulrike; Emini, Luljeta; Rüdisüli, Katharina; Groessbauer, Sara; Mausbach, Brent T; von Känel, Roland

2006-12-01

Systemic hypertension confers a hypercoagulable state. We hypothesized that resting mean blood pressure (MBP) interacts with stress hormones in predicting coagulation activity at rest and with acute mental stress. We measured plasma clotting factor VII activity (FVII:C), FVIII:C, fibrinogen, D-dimer, epinephrine and norepinephrine, and saliva cortisol in 42 otherwise healthy normotensive and hypertensive medication-free men (mean age 43 +/- 14 years) at rest, immediately after stress, and twice during 60 min of recovery from stress. At rest, the MBP-by-epinephrine interaction predicted FVII:C (beta = -0.33, P AUC) predicted D-dimer AUC (beta = 0.34, P = 0.04) independent of MBP. The MBP-by-epinephrine AUC interaction predicted FVII:C AUC (beta = 0.28) and fibrinogen AUC (beta = -0.30), and the MBP-by-norepinephrine AUC interaction predicted FVIII:C AUC (beta = -0.28), all with borderline significance (Ps < 0.09) and independent of age and BMI. MBP significantly altered the association between stress hormones and coagulation activity at rest and, with borderline significance, across the entire stress and recovery interval. Independent of MBP, catecholamines were associated with procoagulant effects and cortisol reactivity dampened the acute procoagulant stress response.

Abnormalities in the cellular phase of blood fibrinolytic activity in systemic lupus erythematosus and in venous thromboembolism

International Nuclear Information System (INIS)

Moroz, L.A.; MacLean, L.D.; Langleben, D.

1986-01-01

Fibrinolytic activities of whole blood and plasma were determined by 125 I-fibrin radiometric assay in 16 normal subjects, and in 11 patients with systemic lupus erythematosus (SLE), 14 with progressive systemic sclerosis (PSS), 23 with venous thromboembolic disease, and 20 patients awaiting elective surgery. Mean whole blood and plasma activities for patients with PSS, and for those awaiting elective surgery, were similar to normal values, as was the mean plasma activity in patients with SLE. However, mean whole blood activity in SLE was significantly decreased compared with normals (p less than 0.05), with mean plasma activity accounting for 44% of mean whole blood activity (compared with 17% in normal subjects), representing a 67% decrease in mean calculated cellular phase activity in SLE, when compared with normals. Since the numbers of cells (neutrophils, monocytes) possibly involved in cellular activity were not decreased, the findings suggest a functional defect in fibrinolytic activity of one or more blood cell types in SLE. An additional finding was the participation of the cellular phase as well as the well-known plasma phase of blood in the fibrinolytic response to thromboembolism

Deep venous thrombus characterization: ultrasonography, elastography and scattering operator

OpenAIRE

Thibaud Berthomier; Ali Mansour; Luc Bressollette; Frédéric Le Roy; Dominique Mottier

2017-01-01

A thrombus or a blood clot is the result of blood coagulation which is a natural process to prevent bleeding. An inappropriate formation of a thrombus in a deep vein is known as Deep Venous Thrombosis (DVT). The main complication of a DVT is a Pulmonary Embolism (PE) which occurs when a thrombus breaks loose and travels to the lungs. DVT, PE, or both are also known as Venous thromboembolism (VTE). It affects an estimated 300,000–600,000 Individuals just in the United States per year and can c...

Evaluating the optimum rest period prior to blood collection for fractionated plasma free metanephrines analysis

LENUS (Irish Health Repository)

Griffin, T.P.

2016-05-01

The high diagnostic accuracy of plasma metanephrines (PMets) in the di-agnosis of Phaeochromocytoma\\/Paraganglioma (PPGL) is well established. Considerable controversy exists regarding optimum sampling conditions for PMets. The use of reference intervals that do not compromise diagnostic sensitivity is recommended. However, the optimum rest period prior to sampling has yet to be clearly established. The aim of this study was to evaluate PMets concentrations in paired blood samples collected following 30 and 40 min seated-rest prior to sampling, in patients in whom it was clinically rea-sonable to suspect that PPGL may be present.

Effect of exercise on erythrocyte count and blood activity concentration after technetium-99m in vivo red blood cell labeling

International Nuclear Information System (INIS)

Konstom, M.A.; Tu'meh, S.; Wynne, J.; Beck, J.R.; Kozlowski, J.; Holman, B.L.

1982-01-01

The effects of exercise on blood radiotracer concentration after technetium-99m in vivo red blood cell labeling was studied. After red blood cell labeling, 13 subjects underwent maximal supine bicycle exercise. Radioactivity, analyzed with a well counter, was measured in heparinized venous blood samples drawn at rest and during peak exercise. Changes in activity were compared with changes in erythrocyte count. Activity and erythrocyte counts increased in erythrocyte count (r=0.78), but did not correlate with either duration of exercise or maximal heart rate. Twenty minutes after termination of exercise, activity and erythrocyte count had decreased from peak exercise values but remained higher than preexercise values. In nine nonexercised control subjects, samples drawn 20 minutes apart showed no change in activity or in erythrocyte count. It was concluded that exercise increases blood activity, primarily because of an increase in erythrocyte count. During radionuclide ventriculography, blood activity must be measured before and after any intervention, particularly exercise, before a change in left ventricular activity can be attributed to a change in left ventricular volume

Regional cerebral blood flow using 133Xenon intra-venous technique, 1

International Nuclear Information System (INIS)

Yonekura, Masahiro; Teramoto, Shigeyoshi; Moriyama, Tadayoshi

1990-01-01

We used the noninvasive 133 Xenon venous technique to measure 3622 regional cerebral blood flows (rCBFs) in 1955 cases for last about six years. The majority of patients was in their fifties or sixties, and their diagnosis was ischemic cerebrovascular disease. Sixty-four healthy, non-hospitalized volunteers (10∼76 years) were studied as control value. The age-related curve of rCBF showed a rapid decrease in young age groups and a gradual decrease in older age groups. The curve was well fitted to the hyperbola (X-13.0621)(Y-42.6038)=556.493. The correlation coefficient was 0.93. This finding showed that the declined rCBF related with age was attributed to more than two factors. When cerebrovascular CO 2 reactivity was tested in the healthy control group, the rCBF on average increased to 90.5 ml/100 g/min from 70.2 ml/100 g/min (28.9%) being accompanied with the elevation of Pco 2 of 11.4 mmHg in arterial blood gas on average. The CO 2 reactivity index was 2.75 ± 1.65 on average. On the other hand, following an intravenous injection of Diamox (1 g) the rCBF increased to 80.0 ml/100 g/min from 59.6 ml/100 g/min (34.2%) on average in the control group. (author)

Biochemical assessment of growth factors and circulation of blood components contained in the different fractions obtained by centrifugation of venous blood.

Science.gov (United States)

Corigiano, M; Ciobanu, G; Baldoni, E; Pompa, G

2014-01-01

The aim of this study was to evaluate a biochemical marker with different elements of a normal blood serum and centrifuged blood serum after a different rotation system. For this technique, we used five fractions of a blood Concentrated Growth Factors system (bCGF) and a particular device for the different rotation program. Blood samples were collected from 10 volunteers aged between 35 and 55 in the Operative Unit of the “Sapienza” University of Rome with only a fraction of different biochemical elements. Through an individual blood phase separator tube of venous blood, active factions of serum and 4 fractions of red buffy coat were taken. The biochemical markers with 14 elements were examined at times: P1-11 minutes, P2-12minutes, P3-15 minutes. Exclusively biological materials which are normally applied in the regeneration techniques for different defects and lesions were used with this technique. After specific rotation programs, a different result was obtained for each cycle: P1, P2, P3. In test tubes obtained by separated blood, we observed a higher concentration of proteins, ions, and other antigens compared to normal blood plasma. Examining the biochemical results of different elements, we observed an increase (P≤0,01). Since each person’s DNA is different, we could not have the same results in 5 fractions of blood concentration, we did, however, find a good increase in only a fraction of proteins, immunoglobulin and different ions. We obtained five fractions after centrifugation, and we had an increase in different biochemical elements compared to normal blood (P≤0,01) which is significant at different times. These biochemical elements were stimulated by different growth factors, which are used by the immune system, and they induced the formation of hard and soft tissues and good regeneration.

Reverse Trendelenburg position is a safer technique for lowering central venous pressure without decreasing blood pressure than clamping of the inferior vena cava below the liver.

Science.gov (United States)

Yoneda, Godai; Katagiri, Satoshi; Yamamoto, Masakazu

2015-06-01

anesthesia was not significantly lower than that during supine position (P = 0.9934). Mean systolic blood pressure was significantly decreased during inferior vena cava clamping (P = 0.0024), but not during reverse Trendelenburg position (P = 0.6344). Reverse Trendelenburg position decreased central venous pressure without significantly decreasing the systolic blood pressure, suggesting that it is possible to perform hepatectomy with reverse Trendelenburg position more safely than with inferior vena cava clamping. © 2015 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Near-infrared vascular imaging in peripheral venous and arterial access

NARCIS (Netherlands)

Cuper, N.J.

2012-01-01

Venous and arterial access are among the most widespread medical procedures performed in children. Especially in young children venous and arterial access can be problematic due to tiny blood vessels that are difficult to localize beneath a layer of baby fat. This thesis describes the development

Selective impairments of resting-state networks in minimal hepatic encephalopathy.

Directory of Open Access Journals (Sweden)

Rongfeng Qi

Full Text Available BACKGROUND: Minimal hepatic encephalopathy (MHE is a neuro-cognitive dysfunction characterized by impairment in attention, vigilance and integrative functions, while the sensorimotor function was often unaffected. Little is known, so far, about the exact neuro-pathophysiological mechanisms of aberrant cognition function in this disease. METHODOLOGY/PRINCIPAL FINDINGS: To investigate how the brain function is changed in MHE, we applied a resting-state fMRI approach with independent component analysis (ICA to assess the differences of resting-state networks (RSNs between MHE patients and healthy controls. Fourteen MHE patients and 14 age-and sex-matched healthy subjects underwent resting-state fMRI scans. ICA was used to identify six RSNs [dorsal attention network (DAN, default mode network (DMN, visual network (VN, auditory network (AN, sensorimotor network (SMN, self-referential network (SRN] in each subject. Group maps of each RSN were compared between the MHE and healthy control groups. Pearson correlation analysis was performed between the RSNs functional connectivity (FC and venous blood ammonia levels, and neuropsychological tests scores for all patients. Compared with the healthy controls, MHE patients showed significantly decreased FC in DAN, both decreased and increased FC in DMN, AN and VN. No significant differences were found in SRN and SMN between two groups. A relationship between FC and blood ammonia levels/neuropsychological tests scores were found in specific regions of RSNs, including middle and medial frontal gyrus, inferior parietal lobule, as well as anterior and posterior cingulate cortex/precuneus. CONCLUSIONS/SIGNIFICANCE: MHE patients have selective impairments of RSNs intrinsic functional connectivity, with aberrant functional connectivity in DAN, DMN, VN, AN, and spared SMN and SRN. Our fMRI study might supply a novel way to understand the neuropathophysiological mechanism of cognition function changes in MHE.

Altered Coupling Between Resting-State Cerebral Blood Flow and Functional Connectivity in Schizophrenia.

Science.gov (United States)

Zhu, Jiajia; Zhuo, Chuanjun; Xu, Lixue; Liu, Feng; Qin, Wen; Yu, Chunshui

2017-10-21

Respective changes in resting-state cerebral blood flow (CBF) and functional connectivity in schizophrenia have been reported. However, their coupling alterations in schizophrenia remain largely unknown. 89 schizophrenia patients and 90 sex- and age-matched healthy controls underwent resting-state functional MRI to calculate functional connectivity strength (FCS) and arterial spin labeling imaging to compute CBF. The CBF-FCS coupling of the whole gray matter and the CBF/FCS ratio (the amount of blood supply per unit of connectivity strength) of each voxel were compared between the 2 groups. Whole gray matter CBF-FCS coupling was decreased in schizophrenia patients relative to healthy controls. In schizophrenia patients, the decreased CBF/FCS ratio was predominantly located in cognitive- and emotional-related brain regions, including the dorsolateral prefrontal cortex, insula, hippocampus and thalamus, whereas an increased CBF/FCS ratio was mainly identified in the sensorimotor regions, including the putamen, and sensorimotor, mid-cingulate and visual cortices. These findings suggest that the neurovascular decoupling in the brain may be a possible neuropathological mechanism of schizophrenia. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com

Varicose Veins: Role of Mechanotransduction of Venous Hypertension

Science.gov (United States)

Atta, Hussein M.

2012-01-01

Varicose veins affect approximately one-third of the adult population and result in significant psychological, physical, and financial burden. Nevertheless, the molecular pathogenesis of varicose vein formation remains unidentified. Venous hypertension exerted on veins of the lower extremity is considered the principal factor in varicose vein formation. The role of mechanotransduction of the high venous pressure in the pathogenesis of varicose vein formation has not been adequately investigated despite a good progress in understanding the mechanomolecular mechanisms involved in transduction of high blood pressure in the arterial wall. Understanding the nature of the mechanical forces, the mechanosensors and mechanotransducers in the vein wall, and the downstream signaling pathways will provide new molecular targets for the prevention and treatment of varicose veins. This paper summarized the current understanding of mechano-molecular pathways involved in transduction of hemodynamic forces induced by blood pressure and tries to relate this information to setting of venous hypertension in varicose veins. PMID:22489273

Analysis of the dynamics of venous blood flow in the context of lower limb temperature distribution and tissue composition in the elderly

Directory of Open Access Journals (Sweden)

Skomudek A

2017-08-01

Full Text Available Aleksandra Skomudek,1,2 Iwona Gilowska,1,3 Ryszard Jasiński,4 Krystyna Rożek-Piechura4 1Department of Physical Education and Physiotherapy, Opole University of Technology, Opolskie, 2Department of Clinical Physiotherapy, 3Department of Biochemistry and Physiology, 4Department of Physiotherapy and Occupational Therapy in Conservative and Interventional Medicine, University of Physical Education in Wroclaw, Wroclaw, Poland Objective: The elderly are particularly vulnerable to degenerative diseases, such as circulatory and respiratory system and vascular system diseases. The objective of this study was therefore to evaluate the distribution of temperature and the dynamics of venous blood flow in the lower limbs (LLs and to assess the interdependence of these parameters in terms of the somatic components in males and females participating in activities at the University of the Third Age. Materials and methods: The study included 60 females (mean age 67.4 years and 40 males (mean age 67.5 years. A body composition assessment was performed using the bioimpedance technique – Tanita BC-418MA. The following parameters were examined: fat%, fat mass, fat-free mass, and total body water. The minimal, maximal, and mean temperature values and their distributions were examined using infrared thermographic camera VarioCAM Head. Measurements of the venous refilling time and the work of the LL venous pump were examined using a Rheo Dopplex II PPG. Results: In males, the mean value of the right LL temperature was 30.58 and the mean value of the left LL was 30.28; the P-value was 0.805769. In females, the mean value of the right LL temperature was 29.58 and the mean value of the left limb was 29.52; the P-value was 0.864773. In males, the right limb blood flow was 34.17 and the left limb blood flow was 34.67; the P-value was 0.359137. In females, the right limb blood flow was 26.89 and the left limb blood flow was 26.09; the P-value was 0.796348. Conclusion

Central venous stenosis among hemodialysis patients is often not associated with previous central venous catheters.

Science.gov (United States)

Kotoda, Atsushi; Akimoto, Tetsu; Kato, Maki; Kanazawa, Hidenori; Nakata, Manabu; Sugase, Taro; Ogura, Manabu; Ito, Chiharu; Sugimoto, Hideharu; Muto, Shigeaki; Kusano, Eiji

2011-01-01

It is widely assumed that central venous stenosis (CVS) is most commonly associated with previous central venous catheterization among the chronic hemodialysis (HD) patients. We evaluated the validity of this assumption in this retrospective study. The clinical records from 2,856 consecutive HD patients with vascular access failure during a 5-year period were reviewed, and a total of 26 patients with symptomatic CVS were identified. Combined with radiological findings, their clinical characteristics were examined. Only seven patients had a history of internal jugular dialysis catheterization. Diagnostic multidetector row computed tomography angiography showed that 7 of the 19 patients with no history of catheterization had left innominate vein stenosis due to extrinsic compression between the sternum and arch vessels. These patients had a shorter period from the time of creation of the vascular access to the initial referral (9.2 ± 7.6 months) than the rest of the patients (35.5 ± 18.6 months, p = 0.0017). Our findings suggest that cases without a history of central venous catheterization may not be rare among the HD patients with symptomatic CVS. However, those still need to be confirm by larger prospective studies of overall chronic HD patients with symptomatic CVS.

Systems biology of coagulation initiation: kinetics of thrombin generation in resting and activated human blood.

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Manash S Chatterjee

2010-09-01

Full Text Available Blood function defines bleeding and clotting risks and dictates approaches for clinical intervention. Independent of adding exogenous tissue factor (TF, human blood treated in vitro with corn trypsin inhibitor (CTI, to block Factor XIIa will generate thrombin after an initiation time (T(i of 1 to 2 hours (depending on donor, while activation of platelets with the GPVI-activator convulxin reduces T(i to ∼20 minutes. Since current kinetic models fail to generate thrombin in the absence of added TF, we implemented a Platelet-Plasma ODE model accounting for: the Hockin-Mann protease reaction network, thrombin-dependent display of platelet phosphatidylserine, VIIa function on activated platelets, XIIa and XIa generation and function, competitive thrombin substrates (fluorogenic detector and fibrinogen, and thrombin consumption during fibrin polymerization. The kinetic model consisting of 76 ordinary differential equations (76 species, 57 reactions, 105 kinetic parameters predicted the clotting of resting and convulxin-activated human blood as well as predicted T(i of human blood under 50 different initial conditions that titrated increasing levels of TF, Xa, Va, XIa, IXa, and VIIa. Experiments with combined anti-XI and anti-XII antibodies prevented thrombin production, demonstrating that a leak of XIIa past saturating amounts of CTI (and not "blood-borne TF" alone was responsible for in vitro initiation without added TF. Clotting was not blocked by antibodies used individually against TF, VII/VIIa, P-selectin, GPIb, protein disulfide isomerase, cathepsin G, nor blocked by the ribosome inhibitor puromycin, the Clk1 kinase inhibitor Tg003, or inhibited VIIa (VIIai. This is the first model to predict the observed behavior of CTI-treated human blood, either resting or stimulated with platelet activators. CTI-treated human blood will clot in vitro due to the combined activity of XIIa and XIa, a process enhanced by platelet activators and which proceeds

Venous and autonomic function in formerly pre-eclamptic women and BMI-matched controls.

Science.gov (United States)

Heidema, Wieteke M; van Drongelen, Joris; Spaanderman, Marc E A; Scholten, Ralph R

2018-03-25

Pre-pregnancy reduced plasma volume increases the risk on subsequent pre-eclamptic pregnancy. Reduced plasma volume is thought to reflect venous reserve capacity, especially when venous vasculature is constricted and sympathetic tone is elevated. As obesity might affect these variables and also relates to pre-eclampsia, increased body weight may underlie these observations. We hypothesized that the relationship between reduced venous reserve and preeclampsia is independent of body mass index (BMI). We compared the non-pregnant venous reserve capacity in 30 formerly pre-eclamptic women, equally divided in 3 BMI-classes (BMI 19.5-24.9, BMI 25-29.9, BMI ≥30) to 30 controls. Cases and controls were matched for BMI, age and parity. The venous reserve capacity was quantified by assessing plasma volume and venous compliance. The autonomic nervous system regulating the venous capacitance was evaluated with heart rate variability analysis in resting supine position and during positive head-up tilt (HUT). Formerly pre-eclamptic women had in supine position lower plasma volume than controls (1339 ± 79 vs 1547 ± 139 ml/m 2 (pBMI-matched controls, reduced venous reserve capacity. This is reflected by lower plasma volume and venous compliance, the autonomic balance is shifted towards sympathetic dominance and lower baroreceptor sensitivity. This suggests that not BMI, but underlying reduced venous reserve relates to pre-eclampsia. This article is protected by copyright. All rights reserved.

Relationship between insulin resistance and tissue blood flow in preeclampsia.

Science.gov (United States)

Anim-Nyame, Nick; Gamble, John; Sooranna, Suren R; Johnson, Mark R; Steer, Philip J

2015-05-01

Preeclampsia is characterized by generalized endothelial dysfunction and impaired maternal tissue perfusion, and insulin resistance is a prominent feature of this disease. The aim of this study was to test the hypothesis that insulin resistance in preeclampsia is related to the reduced resting tissue blood flow. We used venous occlusion plethysmography to compare the resting calf muscle blood flow (measured as QaU) in 20 nulliparous women with preeclampsia and 20 normal pregnant controls matched for maternal age, gestational age, parity and BMI during the third trimester. Fasting blood samples were obtained to measure the plasma concentrations of insulin and glucose, and to calculate the fasting insulin resistance index (FIRI), a measure of insulin resistance in both groups of women. Calf blood flow was significantly reduced in the preeclampsia group (1.93 ± 0.86 QaU), compared with normal pregnant controls (3.94 ± 1.1 QaU, P insulin concentrations and Insulin Resistance Index were significantly higher in preeclampsia compared with normal pregnancy (P insulin concentrations (r = -0.57, P = 0.008) and FIRI (r = -0.59, P = 0.006) in preeclampsia, but not in normal pregnancy. These findings support our hypothesis and raise the possibility that reduced tissue blood flow may a play a role in the increased insulin resistance seen in preeclampsia.

Real-time magnetic resonance imaging of deep venous flow during muscular exercise-preliminary experience.

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Joseph, Arun Antony; Merboldt, Klaus-Dietmar; Voit, Dirk; Dahm, Johannes; Frahm, Jens

2016-12-01

The accurate assessment of peripheral venous flow is important for the early diagnosis and treatment of disorders such as deep-vein thrombosis (DVT) which is a major cause of post-thrombotic syndrome or even death due to pulmonary embolism. The aim of this work is to quantitatively determine blood flow in deep veins during rest and muscular exercise using a novel real-time magnetic resonance imaging (MRI) method for velocity-encoded phase-contrast (PC) MRI at high spatiotemporal resolution. Real-time PC MRI of eight healthy volunteers and one patient was performed at 3 Tesla (Prisma fit, Siemens, Erlangen, Germany) using a flexible 16-channel receive coil (Variety, NORAS, Hoechberg, Germany). Acquisitions were based on a highly undersampled radial FLASH sequence with image reconstruction by regularized nonlinear inversion at 0.5×0.5×6 mm 3 spatial resolution and 100 ms temporal resolution. Flow was assessed in two cross-sections of the lower leg at the level of the calf muscle and knee using a protocol of 10 s rest, 20 s flexion and extension of the foot, and 10 s rest. Quantitative analyses included through-plane flow in the right posterior tibial, right peroneal and popliteal vein (PC maps) as well as signal intensity changes due to flow and muscle movements (corresponding magnitude images). Real-time PC MRI successfully monitored the dynamics of venous flow at high spatiotemporal resolution and clearly demonstrated increased flow in deep veins in response to flexion and extension of the foot. In normal subjects, the maximum velocity (averaged across vessel lumen) during exercise was 9.4±5.7 cm·s -1 for the right peroneal vein, 8.5±4.6 cm·s -1 for the right posterior tibial vein and 17.8±5.8 cm·s -1 for the popliteal vein. The integrated flow volume per exercise (20 s) was 1.9, 1.6 and 50 mL (mean across subjects) for right peroneal, right posterior tibial and popliteal vein, respectively. A patient with DVT presented with peak flow velocities of only

Sex-dependent alterations in resting-state cerebral blood flow, amplitude of low-frequency fluctuations and their coupling relationship in schizophrenia.

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Ma, Xiaomei; Wang, Di; Zhou, Yujing; Zhuo, Chuanjun; Qin, Wen; Zhu, Jiajia; Yu, Chunshui

2016-04-01

We aimed to investigate sex-dependent alterations in resting-state relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling in patients with schizophrenia. Resting-state functional magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling imaging were performed to obtain resting-state amplitude of low-frequency fluctuations and relative cerebral blood flow in 95 schizophrenia patients and 99 healthy controls. Sex differences in relative cerebral blood flow and amplitude of low-frequency fluctuations were compared in both groups. Diagnostic group differences in relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling were compared in male and female subjects, respectively. In both healthy controls and schizophrenia patients, the males had higher relative cerebral blood flow in anterior brain regions and lower relative cerebral blood flow in posterior brain regions than did the females. Compared with multiple regions exhibiting sex differences in relative cerebral blood flow, only the left middle frontal gyrus had a significant sex difference in amplitude of low-frequency fluctuations. In the females, schizophrenia patients exhibited increased relative cerebral blood flow and amplitude of low-frequency fluctuations in the basal ganglia, thalamus and hippocampus and reduced relative cerebral blood flow and amplitude of low-frequency fluctuations in the frontal, parietal and occipital regions compared with those of healthy controls. However, there were fewer brain regions with diagnostic group differences in the males than in the females. Brain regions with diagnostic group differences in relative cerebral blood flow and amplitude of low-frequency fluctuations only partially overlapped. Only the female patients exhibited increased relative cerebral

Alpha adrenergic receptor blockade increases capillarisation and fractional O2 extraction and lowers blood flow in contracting human skeletal muscle

DEFF Research Database (Denmark)

Mortensen, Stefan P; Egginton, Stuart; Madsen, Mads

2017-01-01

AIM: To investigate the effect of elevated basal shear stress on angiogenesis in humans, and the role of enhanced skeletal muscle capillarisation on blood flow and O2 extraction. METHODS: Limb haemodynamics and O2 extraction was measured at rest and during one-leg knee-extensor exercise (12 and 24W......) in 10 healthy untrained young men before and after 4 weeks treatment with an α1 receptor-antagonist (Terazosin, 1-2 mg day(-1) ). Corresponding biopsies were taken from the m. vastus lateralis. RESULTS: Resting leg blood flow was increased by 57% 6 hours following Terazosin treatment (P... basal capillary-to-fibre ratio was 1.69±0.08 and increased to 1.90±0.08 after treatment (Pblood flow and venous lactate levels lower (6-7%; P

Brachial blood flow under relative levels of blood flow restriction is decreased in a nonlinear fashion.

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Mouser, J Grant; Ade, Carl J; Black, Christopher D; Bemben, Debra A; Bemben, Michael G

2018-05-01

Blood flow restriction (BFR), the application of external pressure to occlude venous return and restrict arterial inflow, has been shown to increase muscular size and strength when combined with low-load resistance exercise. BFR in the research setting uses a wide range of pressures, applying a pressure based upon an individual's systolic pressure or a percentage of occlusion pressure; not a directly determined reduction in blood flow. The relationship between relative pressure and blood flow has not been established. To measure blood flow in the arm under relative levels of BFR. Forty-five people (18-40 years old) participated. Arterial occlusion pressure in the right arm was measured using a 5-cm pneumatic cuff. Blood flow in the brachial artery was measured at rest and at pressures between 10% and 90% of occlusion using ultrasound. Blood flow decreased in a nonlinear, stepped fashion. Blood flow decreased at 10% of occlusion and remained constant until decreasing again at 40%, where it remained until 90% of occlusion. The decrease in brachial blood flow is not proportional to the applied relative pressure. The prescription of blood flow restriction should take into account the stimulus provided at each relative level of blood flow. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

CARCINOEMBRYONIC ANTIGEN LEVELS IN THE PERIPHERAL AND MESENTERIC VENOUS BLOOD OF PATIENTS WITH RECTAL CARCINOMA

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Herminio Cabral de REZENDE JUNIOR

2013-12-01

Full Text Available Context The serum carcinoembryonic antigen (CEA is an important prognostic factor in colorectal cancer, however the rectum presents different routes of venous drainage, stating that the level of CEA in peripheral and mesenteric rectal tumors may be different, depending on the location of the tumor in the rectal segment. Objective The goal of this study was to evaluate the relationship between the peripheral and mesenteric venous levels of CEA and the association between these levels and the tumour location in the rectums of patients successfully operated on for rectal carcinoma. Methods Thirty-two patients who were surgically treated for rectal carcinoma were divided into patients with tumours located in the upper rectum (n = 11 or lower rectum (n = 21. The CEA values were assessed by electrochemiluminescence immunoassay. Serum and mesenteric CEA levels were associated with the tumour anatomopathological characteristics: location, histological type, cellular differentiation grade, depth of invasion into the rectal wall, angiolymphatic invasion, tumour, node, and metastasis staging; and the CEA index (≤1.0 or ≥1.0 ng /mL. Results Analysis of the serum CEA values using clinical and anatomopathological parameters revealed no significant association with tumour location, histological type, cellular differentiation grade, depth of invasion into the intestinal wall, and tumour, node, and metastasis staging. The mesenteric CEA levels were significantly associated with the tumour location (P = 0.01. The CEA values in the mesenteric venous blood and the presence of angiolymphatic invasion (P = 0.047 were significantly different. A significant relationship was found between the CEA index value and the rectal tumour location (P = 0.0001. Conclusions The CEA levels were higher in the mesenteric vein in tumours located in the upper rectum and in the presence of angiolymphatic invasion. CEA drainage from lower rectum adenocarcinomas preferentially occurs

Current concepts in repair of extremity venous injury.

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Williams, Timothy K; Clouse, W Darrin

2016-04-01

Extremity venous injury management remains controversial. The purpose of this communication is to offer perspective as well as experiential and technical insight into extremity venous injury repair. Available literature is reviewed and discussed. Historical context is provided. Indication, the decision process for repair, including technical conduct, is delineated. In particular, the authors' experiences in both civilian and wartime injury are used for perspective. Extremity venous injury repair was championed within data from the Vietnam Vascular Registry. However, patterns of extremity venous injury differ between combat and civilian settings. Since Vietnam, civilian descriptive series opine the benefits and potential complications associated with both venous injury repair and ligation. These surround extremity edema, chronic venous insufficiency, thromboembolism, and limb loss. Whereas no clear superiority in either approach has been identified to date, there appears to be no increased risk of pulmonary embolism or chronic venous changes with repair. Newer data from the wars in Iraq and Afghanistan and meta-analysis have reinforced this and also have suggested limb salvage benefit for extremity venous repair in combined arterial and venous injuries in modern settings. The patient's physiologic state and associated injury drive five triage categories suggesting vein injury management. Vein repair thrombosis occurs in a significant proportion, yet many recanalize and possibly have a positive impact on limb venous return. Further, early decompression favors reduced blood loss, acute edema, and inflammation, supporting collateral development. Large soft tissue injury minimizing collateral capacity increases the importance of repair. Constructs of repair are varied with modest differences in patency. Venous shunting is feasible, but specific roles remain nebulous. An aggressive posture toward extremity venous injury repair seems justified today because of the likely

Comparison of arterial and venous blood gases and the effects of analysis delay and air contamination on arterial samples in patients with chronic obstructive pulmonary disease and healthy controls.

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O'Connor, T M; Barry, P J; Jahangir, A; Finn, C; Buckley, B M; El-Gammal, A

2011-01-01

Arterial blood gases (ABGs) are often sampled incorrectly, leading to a 'mixed' or venous sample. Delays in analysis and air contamination are common. We measured the effects of these errors in patients with chronic obstructive pulmonary disease (COPD) exacerbations and controls. Arterial and venous samples were analyzed from 30 patients with COPD exacerbation and 30 controls. Venous samples were analysed immediately and arterial samples separated into non-air-contaminated and air-contaminated specimens and analysed at 0, 30, 60, 90 and 180 min. Mean venous pH was 7.371 and arterial pH was 7.407 (p Air contamination was associated with a clinically significant increase in PO₂ in all samples, including those that were immediately analyzed. Arterial and venous pH differ significantly. Venous pH cannot accurately replace arterial pH. Temporal delays in ABG analysis result in a significant decline in measured pH. ABGs should be analysed within 30 min. Air contamination leads to an immediate increase in measured PO₂, indicating that air-contaminated ABGs should be discarded. Copyright © 2010 S. Karger AG, Basel.

Methods for the determination of skeletal muscle blood flow: development, strengths and limitations

DEFF Research Database (Denmark)

Gliemann, Lasse; Mortensen, Stefan P.; Hellsten, Ylva

2018-01-01

Since the first measurements of limb blood flow at rest and during nerve stimulation were conducted in the late 1800s, a number of methods have been developed for the determination of limb and skeletal muscle blood flow in humans. The methods, which have been applied in the study of aspects...... such as blood flow regulation, oxygen uptake and metabolism, differ in terms of strengths and degree of limitations but most have advantages for specific settings. The purpose of this review is to describe the origin and the basic principles of the methods, important aspects and requirements of the procedures....... One of the earliest methods, venous occlusion plethysmography, is a noninvasive method which still is extensively used and which provides similar values as other more direct blood flow methods such as ultrasound Doppler. The constant infusion thermodilution method remains the most appropriate...

Cord lactate, pH, and blood gases from healthy neonates.

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Shirey, T; St Pierre, J; Winkelman, J

1996-01-01

Lactate, pH, pO2, and pCO2 were determined in arterial, venous, and free-flowing mixed umbilical cord blood obtained from deliveries of apparently healthy neonates. The goals of this study were to establish reference ranges for lactate and pH against which results in cases of high-risk labor and delivery could be compared, to see how the gases correlated with these values, and to determine whether easily accessible mixed umbilical cord blood can serve as the sample in lieu of cord arterial or cord venous blood. Arterial and venous cord lactates were 2.98 mmol/l (+/- 1.40) and 2.80 mmol/l (+/- 1.35), respectively, from 85 cords obtained from vaginal and cesarean deliveries. Mixed cord blood lactate, obtained on 48 cords, was 2.72 mmol/l (+/- 1.28) versus 3.14 and 2.97 mmol/l for the arterial and venous samples from those cords, respectively, and correlated quite well with lactate from the venous specimens (r = 0.97). Differences of > 0.5 mmol/l occurred between mixed and arterial cord bloods in 21 patients, and between mixed and venous cord bloods in 6 of the 48 patients, respectively. We conclude that (1) less than 2.5% of deliveries of apparently healthy neonates have arterial, venous, or mixed cord lactates > or = 7.0 mmol/l and pH pO2 nor pCO2 correlate well with cord venous lactate, and (3) readily available mixed cord blood is a satisfactory specimen for the measurement of venous cord latate.

The effects of arterial carbon dioxide partial pressure and sevoflurane on capillary venous cerebral blood flow and oxygen saturation during craniotomy.

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Klein, Klaus Ulrich; Glaser, Martin; Reisch, Robert; Tresch, Achim; Werner, Christian; Engelhard, Kristin

2009-07-01

Intraoperative routine monitoring of cerebral blood flow and oxygenation remains a technological challenge. Using the physiological principle of carbon dioxide reactivity of cerebral vasculature, we investigated a recently developed neuromonitoring device (oxygen-to-see, O2C device) for simultaneous measurements of regional cerebral blood flow (rvCBF), blood flow velocity (rvVelo), oxygen saturation (srvO2), and hemoglobin amount (rvHb) at the capillary venous level in patients subjected to craniotomy. Twenty-six neurosurgical patients were randomly assigned to anesthesia with 1.4% or 2.0% sevoflurane end-tidal concentration. After craniotomy, a fiberoptic probe was applied on a macroscopically healthy surface of cerebral tissue next to the site of surgery. Simultaneous measurements in 2 and 8 mm cerebral depth were performed in each patient during lower (35 mm Hg) and higher (45 mm Hg) levels (random order) of arterial carbon dioxide partial pressure (PaCO2). The principle of these measurements relies on the combination of laser-Doppler flowmetry (rvCBF, rvVelo) and photo-spectrometry (srvO2, rvHb). Linear models were fitted to test changes of end points (rvCBF, rvVelo, srvO2, rvHb) in response to lower and higher levels of PaCO2, 1.4% and 2.0% sevoflurane end-tidal concentration, and 2 and 8 mm cerebral depth. RvCBF and rvVelo were elevated by PaCO2 independent of sevoflurane concentration in 2 and 8 mm depth of cerebral tissue (P oxygen was decreased by elevated PaCO2. Unchanged levels of rvHb signify that there was no blood loss during measurements. Data suggest that the device allows detection of local changes in blood flow and oxygen saturation in response to different PaCO2 levels in predominant venous cerebral microvessels.

Cardiovascular reflexes during rest and exercise modified by gravitational stresses

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Bonde-petersen, Flemming

The hypotheses tested were whether variations in central venous pressure via the low pressure baroreceptors would take over or modify the arterial baroreceptor function, and further to which extent local and "whole body" hydrostatic stresses influence blood flow distribution. We investigated total forearm and skin blood flow (venous occlusion plethysmography and 133-Xe clearance) and cardiac output (rebreathing method) among other parameters. Hypo-and hypergravitational stresses were simulated by LBNP, LBPP, water immersion and lowering of the arm. The changes in flow distribution in the arm were ascribed to arterial baroreceptor function and not to low pressure baroreceptor activity. The enhancement of venous return during water immersion increased exercise tolerance during heat stress presumably due both to increased stroke volume and decreased venous pooling. The response to sustained handgrip exercise during LBNP and LBPP was not different from control measurements and the effects explained by arterial baroreceptor function. Application of exercise and local hydrostatic stresses in combination with gravitational stresses represent an interesting model for further study of the mechanisms behind the distribution of cardiac output to the peripheral organs.

Measurement of organ blood flow using tritiated water. II. Uterine blood flow in conscious pregnant ewes

International Nuclear Information System (INIS)

Brown, B.W.; Oddy, V.H.; Jones, A.W.

1982-01-01

Total uterine blood flow was measured with a tritiated water (TOH) diffusion method and with radioactive microspheres in six, conscious, pregnant ewes. With continuous infusion of TOH, equilibrium between the TOH concentration in utero-ovarian venous blood and arterial blood was attained within 50 min of the start of the infusion. The concentration of TOH in uterine and foetal tissue and in foetal blood water was the same as that in uterine venous water by 40 min; at this time, the concentration of TOH in the water of amniotic and allantoic fluids was 96% of that in uterine venous blood water. Estimates of total uterine blood flow obtained using TOH were highly correlated with those obtained with microspheres and the corresponding mean flow values obtained with the two techniques did not significantly differ. The percentage of the total uterine blood flow passing through arteriovenous anastomoses ranged from 1.4 to 3.3%

Thermodilution-determined Internal Jugular Venous Flow

DEFF Research Database (Denmark)

Rasmussen, Peter; Widmer, Mario; Hilty, Matthias P

2017-01-01

PURPOSE: Cerebral blood flow (CBF) increases ~20% during whole body exercise although a Kety-Schmidt-determined CBF is reported to remain stable; a discrepancy that could reflect evaluation of arterial vs. internal jugular venous (IJV) flow and/or that CBF is influenced by posture. Here we test...

Effect of exercise on erythrocyte count and blood activity concentration after /sup 99m/Tc in vivo red blood cell labeling

International Nuclear Information System (INIS)

Konstam, M.A.; Tu'meh, S.; Wynne, J.; Beck, J.R.; Kozlowski, J.; Holman, B.L.

1982-01-01

We studied the effect of exercise on blood radiotracer concentration after /sup 99m/Tc in vivo red blood cell labeling. After red blood cell labeling, 13 subjects underwent maximal supine bicycle exercise. Radioactivity, analyzed with a well counter, was measured in heparinized venous blood samples drawn at rest and during peak exercise. Changes in activity were compared with changes in erythrocyte count. Activity and erythrocyte counts increased during exercise in all 13 subjects. Percent increase in activity correlated with percent increase in erythrocyte count (r . -0.78), but did not correlate with either duration of exercise or maximal heart rate. Twenty minutes after termination of exercise, activity and erythrocyte count had decreased from peak exercise values but remained higher than preexercise values. In nine nonexercised control subjects, samples drawn 20 minutes apart showed no change in activity or in erythrocyte count. We conclude that exercise increases blood activity, primarily because of an increase in erythrocyte count. During radionuclide ventriculography, blood activity must be measured before and after any intervention, particularly exercise, before a change in left ventricular activity can be attributed to a change in left ventricular volume

Role of adenosine in the regulation of coronary blood flow in swine at rest and during treadmill exercise

NARCIS (Netherlands)

D.J.G.M. Duncker (Dirk); R. Stubenitsky (René); P.D. Verdouw (Pieter)

1998-01-01

textabstractA pivotal role for adenosine in the regulation of coronary blood flow is still controversial. Consequently, we investigated its role in the regulation of coronary vasomotor tone in swine at rest and during graded treadmill exercise. During exercise,

Electrical foot stimulation and implications for the prevention of venous thromboembolic disease.

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Kaplan, Robert E; Czyrny, James J; Fung, Tat S; Unsworth, John D; Hirsh, Jack

2002-08-01

Venous stasis caused by immobility is an important risk factor for deep vein thrombosis following surgery and lower limb trauma, in bed-ridden medical patients, and in high-risk long distance air travelers. A safe and convenient method for reducing venous stasis would be useful in patients while in hospital and after discharge during their rehabilitation. 49 healthy subjects aged 51-76 were seated for 4 hours during which they received mild electrical stimulation of the calf, or sole of the foot (plantar muscles). Popliteal and femoral venous blood flow velocities were measured via doppler ultrasound. The non-stimulated lower extremity served as the simultaneous control. Subjects completed a questionnaire regarding their acceptance and tolerance of the electrical stimulation. There was a significant increase in venous femoral and popliteal blood flow for both calf (p < 0.035, p < 0.003), and plantar muscles (p < 0.0001, p < 0.009) on the stimulated side compared to the unstimulated side. The magnitude of the effect was similar for calf and plantar muscle stimulation. Subjects did not find the experience uncomfortable, and would use an electrical stimulator if told by their physician that they were at risk for developing blood clots. Mild electrical stimulation of the feet, as well as the calf, is a safe effective and convenient method for counteracting venous stasis and therefore has the potential to reduce the risk of deep vein thrombosis and pulmonary embolism for subjects who are immobilized.

Serious Complication of Central Venous Catheterization Due to Hemothorax: Hemothorax

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Ümmügülsüm Gaygısız

2017-12-01

Full Text Available Central venous catheterization may cause life-threatening complications including pneumothorax and hemothorax. We report a case of multiple trauma complicated with an incidence of hemothorax due to a misplaced central venous catheter. Firstly, the tip of the guide-wire was ruptured in subcutaneous tissue and, secondly, the catheter came out of the vessel and caused hemothorax. During left subclavian catheterization, in this 47-years-old male patient, we could not advance the guide wire forward easily in the first attempt and tried to draw it back. In the second attempt, we inserted a new catheter without any difficulty. The blood gas analyses through the catheter for verification of location revealed its venous nature. After the catheterization, 500 mL hemorrhagic fluid was drained through the ipsilateral chest tube. Control chest X-ray showed that the catheter was in the left hemithorax and a piece of the guide wire was present below the left clavicle. Thorax computerized tomography showed that the catheter entered the thoracic cavity and extended to the paramediastinal region. An emergency surgery was performed to remove the piece of the guide wire and the catheter extending out of the vessel. A common method to check the intravenous insertion of a central catheter into a vein is to verify that the easily drawn blood has the nature of venous blood. This method, however, does not exclude the extravascular placement of the catheter in the presence of ipsilateral hemothorax.

Virtual Resting Pd/Pa From Coronary Angiography and Blood Flow Modelling: Diagnostic Performance Against Fractional Flow Reserve.

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Papafaklis, Michail I; Muramatsu, Takashi; Ishibashi, Yuki; Bourantas, Christos V; Fotiadis, Dimitrios I; Brilakis, Emmanouil S; Garcia-Garcia, Héctor M; Escaned, Javier; Serruys, Patrick W; Michalis, Lampros K

2018-03-01

Fractional flow reserve (FFR) has been established as a useful diagnostic tool. The distal coronary pressure to aortic pressure (Pd/Pa) ratio at rest is a simpler physiologic index but also requires the use of the pressure wire, whereas recently proposed virtual functional indices derived from coronary imaging require complex blood flow modelling and/or are time-consuming. Our aim was to test the diagnostic performance of virtual resting Pd/Pa using routine angiographic images and a simple flow model. Three-dimensional quantitative coronary angiography (3D-QCA) was performed in 139 vessels (120 patients) with intermediate lesions assessed by FFR. The resting Pd/Pa for each lesion was assessed by computational fluid dynamics. The discriminatory power of virtual resting Pd/Pa against FFR (reference: ≤0.80) was high (area under the receiver operator characteristic curve [AUC]: 90.5% [95% CI: 85.4-95.6%]). Diagnostic accuracy, sensitivity and specificity for the optimal virtual resting Pd/Pa cut-off (≤0.94) were 84.9%, 90.4% and 81.6%, respectively. Virtual resting Pd/Pa demonstrated superior performance (pvirtual resting Pd/Pa and FFR (r=0.69, pVirtual resting Pd/Pa using routine angiographic data and a simple flow model provides fast functional assessment of coronary lesions without requiring the pressure-wire and hyperaemia induction. The high diagnostic performance of virtual resting Pd/Pa for predicting FFR shows promise for using this simple/fast virtual index in clinical practice. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Performance and safety of femoral central venous catheters in pediatric autologous peripheral blood stem cell collection.

Science.gov (United States)

Cooling, Laura; Hoffmann, Sandra; Webb, Dawn; Yamada, Chisa; Davenport, Robertson; Choi, Sung Won

2017-12-01

Autologous peripheral blood hematopoietic progenitor cell collection (A-HPCC) in children typically requires placement of a central venous catheter (CVC) for venous access. There is scant published data regarding the performance and safety of femoral CVCs in pediatric A-HPCC. Seven-year, retrospective study of A-HPCC in pediatric patients collected between 2009 and January 2017. Inclusion criteria were an age ≤ 21 years and A-HPCC using a femoral CVC for venous access. Femoral CVC performance was examined by CD34 collection rate, inlet rate, collection efficiency (MNC-FE, CD34-FE), bleeding, flow-related adverse events (AE), CVC removal, and product sterility testing. Statistical analysis and graphing were performed with commercial software. A total of 75/119 (63%) pediatric patients (median age 3 years) met study criteria. Only 16% of children required a CVC for ≥ 3 days. The CD34 collect rate and CD34-FE was stable over time whereas MNC-FE decreased after day 4 in 80% of patients. CD34-FE and MNC-FE showed inter- and intra-patient variability over time and appeared sensitive to plerixafor administration. Femoral CVC showed fewer flow-related AE compared to thoracic CVC, especially in pediatric patients (6.7% vs. 37%, P = 0.0005; OR = 0.12 (95%CI: 0.03-0.45). CVC removal was uneventful in 73/75 (97%) patients with hemostasis achieved after 20-30 min of pressure. In a 10-year period, there were no instances of product contamination associated with femoral CVC colonization. Femoral CVC are safe and effective for A-HPCC in young pediatric patients. Femoral CVC performance was maintained over several days with few flow-related alarms when compared to thoracic CVCs. © 2017 Wiley Periodicals, Inc.

High spatial resolution magnetic resonance imaging of experimental cerebral venous thrombosis with a blood pool contrast agent

International Nuclear Information System (INIS)

Spuentrup, E.; Wiethoff, A.J.; Parsons, E.C.; Spangenberg, P.; Stracke, C.P.

2010-01-01

Purpose: The purpose of this study was to investigate the feasibility of clot visualization in small sinus and cortical veins with contrast enhanced MRA in a cerebral venous thrombosis animal model using a blood pool contrast agent, Gadofosveset, and high spatial resolution imaging. Material and methods: For induction of cerebral venous thrombosis a recently developed combined interventional and microsurgical model was used. Cerebral sinus and cortical vein thrombosis was induced in six pigs. Two further pigs died during the procedure. Standard structural, time-of-flight- and phase contrast-angiograms were followed by fast time resolved high resolution 3D MRA (4D MRA) and subsequent high spatial resolution 3D MRA in the equilibrium phase with and without addition of parallel imaging. Visualization of the clots using the different sequences was subjectively compared and contrast-to-noise ratio (CNR) was assessed. Results: In the remaining six animals the procedure and MR-imaging protocol including administration of Gadofosveset was successfully completed. The 3D high resolution MRA in the equilibrium phase without the addition of parallel imaging was superior to all the other applied MR measurement techniques in terms of visualization of the clots. Only applying this sequence bridging vein thromboses were also seen as a small filling defect with a high CNR of >18. Conclusion: Only the non-accelerated high spatial resolution 3D MRA in the equilibrium in conjunction with the blood pool agent Gadofosveset allows for high-contrast visualization of very small clots in the cerebral sinus and cortical veins. Statement clinical impact: Detection of cortical vein thrombosis is of high clinical impact. Conventional MRI sequences often fail to visualize the clot. We could demonstrate that, in contrast to conventional sequences, with high spatial resolution 3D MRA in the equilibrium in conjunction with the blood pool agent Gadofosveset very small clots in the cerebral sinus and

ABO Blood Group and Risk of Thromboembolic and Arterial Disease

DEFF Research Database (Denmark)

Vasan, Senthil K; Rostgaard, Klaus; Majeed, Ammar

2016-01-01

BACKGROUND: ABO blood groups have been shown to be associated with increased risks of venous thromboembolic and arterial disease. However, the reported magnitude of this association is inconsistent and is based on evidence from small-scale studies. METHODS AND RESULTS: We used the SCANDAT2...... (Scandinavian Donations and Transfusions) database of blood donors linked with other nationwide health data registers to investigate the association between ABO blood groups and the incidence of first and recurrent venous thromboembolic and arterial events. Blood donors in Denmark and Sweden between 1987......-up. Compared with blood group O, non-O blood groups were associated with higher incidence of both venous and arterial thromboembolic events. The highest rate ratios were observed for pregnancy-related venous thromboembolism (incidence rate ratio, 2.22; 95% confidence interval, 1.77-2.79), deep vein thrombosis...

Risk Factors for Venous Thromboembolism in Hospitalized Patients in the Chinese Population

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Wang Chunling

2018-04-01

Full Text Available Venous thromboembolism (VTE refers to the formation of a blood clot inside veins and has a high risk of inducing medical accidents. An effective risk assessment model will help screen high risk populations and prevent the occurrence of VTE. In this study, 287 VTE cases were collected and analyzed for risk factors in a Chinese population. The risks of VTE were evaluated using the Caprini and Padua models. Our results indicated that the Caprini model was more effective in evaluating VTE risk among hospitalized patients than the Padua model. As well, the Caprini model was more relevant in VTE risk assessment among surgery patients compared with internal medicine patients, while the Padua model showed no significant differences. In our studies, the most frequent risk factors included obesity, medical patients currently at bed rest, and severe lung disease. Our studies provide clinical support on selecting the suitable risk assessment model of VTE in the Chinese population.

Assessment of resting-state blood flow through anterior cerebral arteries using trans-cranial doppler recordings.

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Huang, Hanrui; Sejdić, Ervin

2013-12-01

Trans-cranial Doppler (TCD) recordings are used to monitor cerebral blood flow in the main cerebral arteries. The resting state is usually characterized by the mean velocity or the maximum Doppler shift frequency (an envelope signal) by insonating the middle cerebral arteries. In this study, we characterized cerebral blood flow in the anterior cerebral arteries. We analyzed both envelope signals and raw signals obtained from bilateral insonation. We recruited 20 healthy patients and conducted the data acquisition for 15 min. Features were extracted from the time domain, the frequency domain and the time-frequency domain. The results indicate that a gender-based statistical difference exists in the frequency and time-frequency domains. However, no handedness effect was found. In the time domain, information-theoretic features indicated that mutual dependence is higher in raw signals than in envelope signals. Finally, we concluded that insonation of the anterior cerebral arteries serves as a complement to middle cerebral artery studies. Additionally, investigation of the raw signals provided us with additional information that is not otherwise available from envelope signals. Use of direct trans-cranial Doppler raw data is therefore validated as a valuable method for characterizing the resting state. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

[Digital blood flow measurement by venous occlusion plethysmography in Raynaud's phenomenon. Value of the rewarming test].

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Cristol, R; Debray, J

1986-01-01

The fingertip blood flow measured by mercury strain gauge plethysmography with venous occlusion, at 22 degrees C room temperature, had significantly lower mean values in 190 patients with Raynaud's phenomenon (55 men aged 49 yrs +/- 16, 135 women aged 48 yrs +/- 16) than in 40 age and sex matched controls: 18 ml/100 ml/minute +/- 14.6 versus 35 ml/100 ml/minute +/- 15 at level p less than 0.01. The mean fingertip blood flow was significantly lower (p less than 0.01) in 31 cases of scleroderma and 32 cases of pulpar necrosis (respectively 13 ml +/- 13 and 11 ml +/- 8) than in 55 cases of primary Raynaud's disease (no detectable etiology and normal capillaroscopy 5 years after onset) or in 34 cases of mild Raynaud's phenomenon (respectively 21.6 +/- 16 and 24.4 +/- 18). A warming test (both hands in water at 45 degrees C during 3 minutes) was performed in 50 cases with low basal fingertip blood flow. It induced a "normalized" flow in 22 cases (mostly primary or mild Raynaud), a partly improved flow in 20 cases (mostly secondary Raynaud) and no improvement in 8 cases (scleroderma). The warming test appears to be clinically useful to assess the vasospasm and the vasodilating capabilities.

Wide-area mapping of resting state hemodynamic correlations at microvascular resolution with multi-contrast optical imaging (Conference Presentation)

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Senarathna, Janaka; Hadjiabadi, Darian; Gil, Stacy; Thakor, Nitish V.; Pathak, Arvind P.

2017-02-01

Different brain regions exhibit complex information processing even at rest. Therefore, assessing temporal correlations between regions permits task-free visualization of their `resting state connectivity'. Although functional MRI (fMRI) is widely used for mapping resting state connectivity in the human brain, it is not well suited for `microvascular scale' imaging in rodents because of its limited spatial resolution. Moreover, co-registered cerebral blood flow (CBF) and total hemoglobin (HbT) data are often unavailable in conventional fMRI experiments. Therefore, we built a customized system that combines laser speckle contrast imaging (LSCI), intrinsic optical signal (IOS) imaging and fluorescence imaging (FI) to generate multi-contrast functional connectivity maps at a spatial resolution of 10 μm. This system comprised of three illumination sources: a 632 nm HeNe laser (for LSCI), a 570 nm ± 5 nm filtered white light source (for IOS), and a 473 nm blue laser (for FI), as well as a sensitive CCD camera operating at 10 frames per second for image acquisition. The acquired data enabled visualization of changes in resting state neurophysiology at microvascular spatial scales. Moreover, concurrent mapping of CBF and HbT-based temporal correlations enabled in vivo mapping of how resting brain regions were linked in terms of their hemodynamics. Additionally, we complemented this approach by exploiting the transit times of a fluorescent tracer (Dextran-FITC) to distinguish arterial from venous perfusion. Overall, we demonstrated the feasibility of wide area mapping of resting state connectivity at microvascular resolution and created a new toolbox for interrogating neurovascular function.

Hypodense bubbles in acute extradural haematomas following venous sinus tear

International Nuclear Information System (INIS)

Chee, C.P.; Habib, Z.A.

1991-01-01

Between January 1982 and December 1989, 12 patients with 13 acute extradural haematomas as a result of injury involving the venous sinuses were treated by the first author. The CT scan apperances in 6 cases were remarkable in that there were large bubbles of low density in the hyperdense haematomas and liquid blood was found during the operation. The possible underlying pathophysiological changes that gave rise this appearance are discussed. The CT scan appearance and the proximity of the clot to the venous sinuses should alert the neurosurgeon to the high probabilities of venous sinus tear such that proper treatment can be offered. (orig.)

Hypodense bubbles in acute extradural haematomas following venous sinus tear

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Chee, C.P.; Habib, Z.A. (Malaya Univ. Hospital, Kuala Lumpur (Malaysia). Neurosurgical and Radiological Services)

1991-04-01

Between January 1982 and December 1989, 12 patients with 13 acute extradural haematomas as a result of injury involving the venous sinuses were treated by the first author. The CT scan apperances in 6 cases were remarkable in that there were large bubbles of low density in the hyperdense haematomas and liquid blood was found during the operation. The possible underlying pathophysiological changes that gave rise this appearance are discussed. The CT scan appearance and the proximity of the clot to the venous sinuses should alert the neurosurgeon to the high probabilities of venous sinus tear such that proper treatment can be offered. (orig.).

Uso de sangue arterial e venoso no exame do equilíbrio ácido-básico de novilhos normais ou com acidose metabólica Arterial and venous blood in the assessment of blood gas and acid-base status in healthy steers or steers with metabolic acidosis

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Maria Claudia Araripe Sucupira

2003-10-01

Full Text Available Doze novilhos foram utilizados para comparar os resultados hemogasométricos de sangue arterial e venoso. Esses animais foram divididos em três grupos idênticos, recebendo: 1- dieta balanceada, proporcionando ganho de peso de 600g/d; 2- dieta de mantença em proteína e energia e 3- dieta com teores 20% abaixo da mantença. Amostras de sangue arterial (artéria auricular caudal e venoso (veia jugular foram colhidas por 11 quinzenas consecutivas, num total de 132 amostras. Ao término do experimento, os animais dos grupos 2 e principalmente 3 apresentaram acidose metabólica moderada. Maiores valores de pH e de pO2 foram constatados no sangue arterial enquanto os teores de bicarbonato, TCO2, BE e pCO2 foram superiores no sangue venoso. Existiram altas correlações entre os valores do sangue arterial e venoso para o pH (r = 0,81, bicarbonato e TCO2 (r = 0,94, sendo esta correlação média, mas significativa, no caso da pCO2 (r = 0,56 e inexistente na pO2 (r= -0,06. Quanto maiores foram os valores de pCO2 maiores foram os teores de bicarbonato (r = 0,54 e TCO2 (r =0,56. Apesar das discrepâncias de pH, das concentrações de bicarbonato, TCO2, e mesmo de pCO2 obtidos no sangue venoso e arterial, é possível estimar, adequadamente, a partir do primeiro esses valores nas amostras arteriais em novilhos normais e com moderado grau de acidose metabólica. Nos casos de alterações respiratórias, amostras de sangue arterial devem ser colhidas para determinação de pO2. A colheita de sangue venoso foi mais facilmente realizada que do sangue arterial.Twelve steers were used to compare the blood gas and acid-base status. The animals were randomly divided in three equal groups according to the following diets: 1- adequate, for gaining 600g/head/d ; 2- protein and energy levels to meet the maintenence; 3- protein and energy 20% below the maintenance levels. One hundred thirty-two arterial blood (caudal auricular artery or venous blood (jugular vein

Reduction in central venous pressure enhances erythropoietin synthesis

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Montero, D.; Rauber, S.; Gøtze, Jens Peter

2016-01-01

AIMS: Erythropoiesis is a tightly controlled biological event, but its regulation under non-hypoxic conditions, however, remains unresolved. We examined whether acute changes in central venous blood pressure (CVP) elicited by whole-body tilting affect erythropoietin (EPO) concentration according...

HTA of genetic testing for susceptibility to venous thromboembolism in Italiy

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Betti Silvia

2012-06-01

Full Text Available Venous thromboembolism (VTE is a condition in which a thrombus (a solid mass of blood constituents forms in a vein. VTE represents an extremely common medical problem manifested as either deep venous thrombosis (DVT or pulmonary embolism (PE affecting apparently healthy as well as hospitalized patients. Often PE is the physiopathological consequence of the DVT of low extremities vessels, in particular of the calve......

Plasma volume shifts with immersion at rest and two exercise intensities.

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Ertl, A C; Bernauer, E M; Hom, C A

1991-04-01

Eight men were studied to determine the effect of cycling exercise on plasma volume (PV) during water immersion to the xiphoid process (WIX). In all protocols the subjects were seated upright. After 30 min of rest, subjects were immersed in 34.5 degrees C water and seated on a cycling ergometer. During three 1 h WIX protocols, subjects either remained at rest (No Ex) or pedaled from minutes 20 to 30 at 38% (Ex1) or 62% (Ex2) of peak oxygen consumption (VO2peak). Hematocrit (Hct) and hemoglobin concentration [( Hb]) from venous blood samples were compared pre-WIX and at minutes 20, 30, 40, and 60. Percent change in PV (delta PV) was calculated from pre-WIX Hct and [Hb] within each protocol. Hct and [Hb] decreased after 20 min of resting WIX (P less than 0.017). In the No Ex protocol, there were no further significant changes in these variables, with delta PV values of +10.4% at minute 20 and at a peak of +13.5% at minute 40. In Ex1 and Ex2, cycling increased Hct and [Hb] (P less than 0.01, minute 30 vs No Ex), with delta PV values at minute 30 of +3.7% and -0.9%, respectively, vs +12.8% in No Ex. Minute 60 values between protocols were not significantly different (mean delta PV of +10.8 +/- 0.6% SD). The hemodilution associated with WIX was either partially or completely attenuated by cycling exercise; the degree of hemoconcentration was related to exercise intensity. The exercise-induced hemoconcentration was reversed by 30 min of resting WIX. Exercise during WIX appears to cause similar decreases in PV, as does exercise in air provided that postural hemoconcentration prior to exercise is not already maximal.

Disrupted functional connectivity of the anterior cingulate cortex in cirrhotic patients without overt hepatic encephalopathy: a resting state fMRI study.

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Long Jiang Zhang

Full Text Available BACKGROUND: To evaluate the changes of functional connectivity of the anterior cingulate cortex (ACC in patients with cirrhosis without overt hepatic encephalopathy (HE using resting state functional MRI. METHODOLOGY/PRINCIPAL FINDINGS: Participants included 67 cirrhotic patients (27 minimal hepatic encephalopathy (MHE and 40 cirrhotic patients without MHE (non-HE, and 40 age- and gender- matched healthy controls. rsfMRI were performed on 3 Telsa scanners. The pregenual ACC resting-state networks (RSNs were characterized by using a standard seed-based whole-brain correlation method and compared between cirrhotic patients and healthy controls. Pearson correlation analysis was performed between the ACC RSNs and venous blood ammonia levels, neuropsychological tests (number connection test type A [NCT-A] and digit symbol test [DST] scores in cirrhotic patients. All thresholds were set at P<0.05, with false discovery rate corrected. Compared with controls, non-HE and MHE patients showed significantly decreased functional connectivity in the bilateral ACC, bilateral middle frontal cortex (MFC, bilateral middle cingulate cortex (MCC, bilateral superior temporal gyri (STG/middle temporal gyri (MTG, bilateral thalami, bilateral putamen and bilateral insula, and increased functional connectivity of bilateral precuneus and left temporo-occipital lobe and bilateral lingual gyri. Compared with non-HE patients, MHE showed the decreased functional connectivity of right MCC, bilateral STG/MTG and right putamen. This indicates decreased ACC functional connectivity predominated with the increasing severity of HE. NCT-A scores negatively correlated with ACC functional connectivity in the bilateral MCC, right temporal lobe, and DST scores positively correlated with functional connectivity in the bilateral ACC and the right putamen. No correlation was found between venous blood ammonia levels and functional connectivity in ACC in cirrhotic patients. CONCLUSIONS

A study on regional cerebral blood flow at rest and stress state in anxiety disorder patients

International Nuclear Information System (INIS)

Wan Li; Liu Jian

2002-01-01

Objective: To investigate he characteristics of rest and stress regional cerebral blood flow (rCBF) in naive anxiety disorder patients. Methods: Twenty naive anxiety disorder patients were enrolled in the study with twenty healthy volunteers as controls. The rest and stress 99 Tc m -ethylene cystein dimer (ECD) SPECT were performed separately at 2 consecutive days, Raven reasoning test was used as a stressor. Results: 1) Compared to the healthy controls, the patients' rest rCBF of the frontal lobe, temporal lobe, thalamus and basal ganglia were significantly lower (P<0.05 and 0.01). 2)The patients' stress rCBF of the frontal lobe, temporal lobe, part occipital lobe, part parietal lobe, thalamus and basal ganglia were significantly lower compared to the healthy controls' (P<0.05 and 0.01). 3) Opposite to the healthy controls, the rCBF of patients increased significantly after stressor simulating. Conclusions: The hypofunction of frontal lobe, temporal lobe, thalamus and basal ganglia may exist in naive anxiety disorder patients. The abnormal rCBF of patients after simulating may be one of the characteristics of anxiety disorder

Transplacental diffusion and blood flow of gravid bovine uterus

International Nuclear Information System (INIS)

Reynolds, L.P.; Ferrell, C.L.; Ford, S.P.

1985-01-01

Electromagnetic blood flow transducers and uterine arterial, uterine venous, umbilical venous, fetal femoral arterial, and fetal femoral venous catheters were implanted in 11 cows on day 161 +/- 4 of gestation. Antipyrine (0.66 M) plus NaCl (0.16 M) dissolved in deuterium oxide (D 2 O), or H 2 O, was infused at a constant rate into the fetal femoral vein catheter. Concentrations of antipyrine and D 2 O in uterine arterial and venous blood and antipyrine in fetal arterial and umbilical venous blood, as well as middle uterine arterial blood flow (electromagnetic transducer), were determined. Antipyrine and D 2 O gave similar estimates (steady-state diffusion method) of gravid uterine blood flow. In addition, the slope of the regression of D 2 O on antipyrine estimates was not different from one. Electromagnetic transducers gave estimates of uterine blood flow that were 32-42% of those obtained with steady-state diffusion but were correlated with estimates obtained by use of both antipyrine and D 2 O. The transplacental clearance rate of antipyrine was similar (per kg placenta) to that observed in ewes. It was suggested that the maternal and fetal microvasculatures of the bovine placenta could have a concurrent arrangement with vascular shunts or maldistribution of flows, as has been suggested for the ewe

Regional cerebral blood flow in psychiatry: The resting and activated brains of schizophrenic patients

International Nuclear Information System (INIS)

Gur, R.E.

1984-01-01

The investigation of regional brain functioning in schizophrenia has been based on behavioral techniques. Although results are sometimes inconsistent, the behavioral observations suggest left hemispheric dysfunction and left hemispheric overreaction. Recent developments in neuroimaging technology make possible major refinements in assessing regional brain function. Both anatomical and physiological information now be used to study regional brain development in psychiatric disorders. This chapter describes the application of one method - the xenon-133 technique for measuring regional cerebral blood flow (rCBF) - in studying the resting and activated brains of schizoprenic patients

The effect of CPAP treatment on venous lactate and arterial blood gas among obstructive sleep apnea syndrome patients.

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Lin, Ting; Huang, Jie-Feng; Lin, Qi-Chang; Chen, Gong-Ping; Wang, Bi-Ying; Zhao, Jian-Ming; Qi, Jia-Chao

2017-05-01

The aim of this observational study was to investigate the influence of continuous positive airway pressure (CPAP) on arterial blood gas and venous lactate, markers of tissue hypoxia, among obstructive sleep apnea syndrome (OSAS) patients, and determine the risk factor of serum lactate and hydrogen ion concentration (PH) in OSAS patients. One-hundred and nine patients with newly diagnosed OSAS were enrolled in the study. All individuals were treated with CPAP for one night. Venous lactate and arterial blood gas were gathered from all subjects in the morning at the end of polysomnography and the next morning after CPAP treatment. Of the 109 selected subjects, the average lactate level was 2.23 ± 0.59 mmol/L, and the mean PH, PaO 2 , and PaCO 2 were 7.380 ± 0.23, 88.14 ± 17.83 mmHg, and 38.70 ± 4.28 mmHg, respectively. Compared to baseline, lactic acid significantly decreased (2.10 ± 0.50 mmol/L, p = 0.03), while PH increased (7.388 ± 0.27, p treatment. In addition, neck circumference and the polysomnographic parameters, including apnea-hypopnea index, oxygen desaturation index (ODI), mean oxygen saturation (SpO 2 ), and the percentage of sleep time with SpO 2 treatment could reduce serum lactate and increase PH in OSAS patients and might alleviate acid-base balance disorders in OSAS. Furthermore, TS90 % was a risk factor for elevated lactate, and age was independently associated with PH.

Renal and femoral venous blood flows are regulated by different mechanisms dependent on α-adrenergic receptor subtypes and nitric oxide in anesthetized rats.

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Fioretti, Alexandre C; Ogihara, Cristiana A; Cafarchio, Eduardo M; Venancio, Daniel P; de Almeida, Roberto Lopes; Antonio, Bruno B; Sato, Monica A

2017-12-01

Venous and arterial walls are responsive to sympathetic system and circulating substances, nevertheless, very few is known about the venous blood flow regulation simultaneously to arterial vascular beds. In this study, we compared the venous and arterial blood flow regulation in visceral and muscular beds upon injection of different doses of vasoactive drugs which act in arterial vascular beds. Anesthetized adult male Wistar rats underwent to right femoral artery and vein cannulation for hemodynamic recordings and infusion of drugs. Doppler flow probes were placed around the left renal artery and vein, and left femoral artery and vein to evaluate the changes in flood flow. Phenylephrine (PHE) injection (α 1 -adrenergic receptor agonist) elicited vasoconstriction in all arteries and veins. Intravenous prazosin (PZS) (1mg/kg, α 1 -adrenergic receptor blocker) caused renal artery vasodilation, but not in the other beds. Vasoconstrictor effect of PHE was abolished by PZS in all vascular beds, except in femoral vein. Phentolamine (PTL) injection (1mg/kg, α 1 /α 2 -adrenergic receptor blocker) produced renal artery vasodilation with no change in other beds. After PTL, the vasoconstriction evoked by PHE was abolished in all vascular beds. Sodium Nitroprusside (SNP), a nitric oxide donor, elicited vasodilation in all beds, and after PTL but not post PZS injection, SNP enhanced the vasodilatory effect in femoral vein. Our findings suggest that the vasoconstriction in renal and femoral veins is mediated by different subtypes of α-adrenoceptors. The nitric oxide-dependent vasodilation in femoral vein enhances when α 2 -adrenoceptors are not under stimulation, but not in the other vascular beds investigated. Copyright © 2017 Elsevier Inc. All rights reserved.

Venous access: options, approaches and issues

International Nuclear Information System (INIS)

Asch, M.R.

2001-01-01

Venous access is an essential part of medical practice. It is needed to obtain blood samples to make the diagnosis and to administer fluids or medicines as part of treatment. Although relatively new in the history of medicine, the placement and maintenance of the various venous access devices now occupies a significant portion of many vascular and interventional radiology practices. Thus, it is important to have a thorough understanding of these devices and their uses. The first long-term venous access devices were used in 1973. These were placed via a surgical cut-down on the subclavian vein. In 1982, the first subcutaneous implantable ports were described. These procedures were initially performed by surgeons, but over the last 5-10 years, both the insertion and management of these devices has shifted to interventional radiologists. Peripherally inserted central catheter (PICC) lines have almost completely supplanted the use of standard central lines (Fig. 1). A number of factors have facilitated this - namely, ready and less expensive room access, outpatient procedure and radiologists' accessibility and familiarity with image-guidance procedures and catheters and guide wires. (author)

When one port does not return blood: two case reports of rare causes for misplaced central venous catheters

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Sandra Pereira

2016-01-01

Full Text Available We present two cases of misplaced central venous catheters having in common the absence of free blood return from one lumen immediately after placement. The former is a case of right hydrothorax associated with central venous catheterization with the catheter tip in intra-pleural location. In this case the distal port was never patent. In the latter case there was an increased aspiration pressure through the middle port due to a catheter looping.The absence of free flow on aspiration from one lumen of a central catheter should not be undervalued. In these circumstances the catheter should not be used and needs to be removed. Resumo: Apresentamos dois casos de mau posicionamento de cateter venoso central. Têm em comum a ausência do retorno sanguíneo livre em um dos lúmens imediatamente após a colocação. O primeiro é um caso de hidrotórax direito associado ao cateterismo venoso central, com a ponta do cateter em localização intrapleural. Nesse caso, a porta distal nunca esteve patente. No segundo caso houve um aumento da pressão de aspiração através da porta medial por causa da formação de alça no cateter.A ausência de fluxo livre na aspiração de um lúmen do cateter central não deve ser subestimada. Nessas circunstâncias, o cateter não deve ser usado e deve ser removido. Keywords: Central venous catheter, Hydrothorax, Looping, Malposition, Palavras-chave: Cateter venoso central, Hidrotórax, Alça, Mau posicionamento

Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

International Nuclear Information System (INIS)

Qi, Rongfeng; Zhang, Long Jiang; Zhong, Jianhui; Zhang, Zhiqiang; Ni, Ling; Zheng, Gang; Lu, Guang Ming

2013-01-01

Background and purpose: Little is known about the role of thalamus in the pathophysiology of minimal hepatic encephalopathy (MHE). The purpose of this study was to investigate whether the thalamic functional connectivity was disrupted in cirrhotic patients with MHE by using resting-state functional magnetic resonance imaging (rs-fMRI). Materials and Methods: Twenty seven MHE patients and twenty seven age- and gender- matched healthy controls participated in the rs-fMRI scans. The functional connectivity of 11 thalamic nuclei were characterized by using a standard seed-based whole-brain correlation method and compared between MHE patients and healthy controls. Pearson correlation analysis was performed between the thalamic functional connectivity and venous blood ammonia levels/neuropsychological tests scores of patients. Results: The ventral anterior nucleus (VAN) and the ventral posterior medial nucleus (VPMN) in each side of thalamus showed abnormal functional connectivities in MHE. Compared with healthy controls, MHE patients demonstrated significant decreased functional connectivity between the right/left VAN and the bilateral putamen/pallidum, inferior frontal gyri, insula, supplementary motor area, right middle frontal gyrus, medial frontal gyrus. In addition, MHE patients showed significantly decreased functional connectivity with the right/left VPMN in the bilateral middle temporal gyri (MTG), temporal lobe, and right superior temporal gyrus. The venous blood ammonia levels of MHE patients negatively correlated with the functional connectivity between the VAN and the insula. Number connecting test scores showed negative correlation with the functional connectivity between the VAN and the insula, and between the VPMN and the MTG. Conclusion: MHE patients had disrupted thalamic functional connectivity, which mainly located in the bilateral ventral anterior nuclei and ventral posterior medial nuclei. The decreased connectivity between thalamus and many

Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

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Qi, Rongfeng [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Zhang, Long Jiang, E-mail: kevinzhanglongjiang@yahoo.com.cn [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Zhong, Jianhui [Department of Biomedical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, Zhiqiang; Ni, Ling; Zheng, Gang [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China); Lu, Guang Ming, E-mail: cjr.luguangming@vip.163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing 210002 (China)

2013-05-15

Background and purpose: Little is known about the role of thalamus in the pathophysiology of minimal hepatic encephalopathy (MHE). The purpose of this study was to investigate whether the thalamic functional connectivity was disrupted in cirrhotic patients with MHE by using resting-state functional magnetic resonance imaging (rs-fMRI). Materials and Methods: Twenty seven MHE patients and twenty seven age- and gender- matched healthy controls participated in the rs-fMRI scans. The functional connectivity of 11 thalamic nuclei were characterized by using a standard seed-based whole-brain correlation method and compared between MHE patients and healthy controls. Pearson correlation analysis was performed between the thalamic functional connectivity and venous blood ammonia levels/neuropsychological tests scores of patients. Results: The ventral anterior nucleus (VAN) and the ventral posterior medial nucleus (VPMN) in each side of thalamus showed abnormal functional connectivities in MHE. Compared with healthy controls, MHE patients demonstrated significant decreased functional connectivity between the right/left VAN and the bilateral putamen/pallidum, inferior frontal gyri, insula, supplementary motor area, right middle frontal gyrus, medial frontal gyrus. In addition, MHE patients showed significantly decreased functional connectivity with the right/left VPMN in the bilateral middle temporal gyri (MTG), temporal lobe, and right superior temporal gyrus. The venous blood ammonia levels of MHE patients negatively correlated with the functional connectivity between the VAN and the insula. Number connecting test scores showed negative correlation with the functional connectivity between the VAN and the insula, and between the VPMN and the MTG. Conclusion: MHE patients had disrupted thalamic functional connectivity, which mainly located in the bilateral ventral anterior nuclei and ventral posterior medial nuclei. The decreased connectivity between thalamus and many

Use of the direct puncture technique in management of capillaro-venous malformations: case report

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Tyagi Isha

2002-03-01

Full Text Available Abstract Background Preoperative devascularization of the capillaro-venous malformations located in the aero-digestive tract is important for surgeons, to minimize blood loss during surgical excision of malformations. Case presentation Here we present two cases of capillaro-venous malformation in which we could successfully achieve preoperative devascularization, by directly injecting n-butyl cyano acrylate into the capillaro-venous bed. This technique is relatively easy, safe and cheap, and can be carried out immediately before surgery.

A novel approach for assessing the progression of deep venous thrombosis by area of venous thrombus in ultrasonic elastography.

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Wang, Chao; Wang, Lei; Zhang, Yuhui; Chen, Ming

2014-04-01

Exact age determination of deep venous thrombosis (DVT) is important for an appropriate treatment. The purpose of this present study is to assess the age of acute DVT with the area of venous thrombi in elasticity imaging during the thrombosis procession. The thrombus area is obtained from a specially designed program. It was applied to clot specimens induced in human great saphenous (n = 15) at selected time points following the initiation of thrombosis. The relative mean proportion of blood clots was 50.01% ± 12.44% at day 1; 69.94% ± 8.19% at day 3; 81.93% ± 6.15% at day 6; and 92.37% ± 4.06% at day 9. The results indicated that the thrombus area increased significantly over time, while the normalized strain values inside the thrombus changed only a little. The pathological analyses also showed the same results. Therefore, we conclude that the area of venous thrombi in elasticity imaging may be a novel function for acute DVT staging.

Venous and arterial thrombosis: Two aspects of the same disease?

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Paolo Prandoni

2009-01-01

Full Text Available Paolo PrandoniDepartment of Cardiothoracic and Vascular Sciences, Thromboembolism Unit, University Hospital of Padua Padua, ItalyAbstract: An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.Keywords: venous thromboembolism, deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke, atherosclerosis

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to Vitis vinifera L. seeds extract and maintenance of normal venous blood flow pursuant to Article 13(5) of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

Following an application from Nutrilinks Sarl, submitted pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Belgium, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim...... related to Vitis vinifera L. seeds extract and maintenance of normal venous blood flow. The Panel considers that the food constituent, which is the subject of the health claim, is sufficiently characterised. The claimed effect, maintenance of normal venous blood flow, is a beneficial physiological effect...... and did not measure venous blood flow, the Panel considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim. The Panel concludes that a cause and effect relationship has not been established between the consumption of Vitis vinifera L. seeds extract...

Relationship Between Blood Flow and Performance Recovery: A Randomized, Placebo-Controlled Study.

Science.gov (United States)

Borne, Rachel; Hausswirth, Christophe; Bieuzen, François

2017-02-01

To investigate the effect of different limb blood-flow levels on cycling-performance recovery, blood lactate concentration, and heart rate. Thirty-three high-intensity intermittent-trained athletes completed two 30-s Wingate anaerobic test sessions, 3 × 30-s (WAnT 1-3) and 1 × 30-s (WAnT 4), on a cycling ergometer. WAnT 1-3 and WAnT 4 were separated by a randomly assigned 24-min recovery intervention selected from among blood-flow restriction, passive rest, placebo stimulation, or neuromuscular electrical-stimulation-induced blood flow. Calf arterial inflow was measured by venous occlusion plethysmography at regular intervals throughout the recovery period. Performance was measured in terms of peak and mean power output during WAnT 1 and WAnT 4. After the recovery interventions, a large (r = .68 [90% CL .42; .83]) and very large (r = .72 (90% CL .49; .86]) positive correlation were observed between the change in calf arterial inflow and the change in mean and peak power output, respectively. Calf arterial inflow was significantly higher during the neuromuscular-electrical-stimulation recovery intervention than with the blood-flow-restriction, passive-rest, and placebo-stimulation interventions (P .05). No recovery effect was linked to heart rate or blood lactate concentration levels. For the first time, these data support the existence of a positive correlation between an increase in blood flow and performance recovery between bouts of high-intensity exercise. As a practical consideration, this effect can be obtained by using neuromuscular electrical stimulation-induced blood flow since this passive, simple strategy could be easily applied during short-term recovery.

Comparison of arterial and venous blood gases and the effects of analysis delay and air contamination on arterial samples in patients with chronic obstructive pulmonary disease and healthy controls.

LENUS (Irish Health Repository)

O'Connor, T M

2012-01-31

BACKGROUND: Arterial blood gases (ABGs) are often sampled incorrectly, leading to a \\'mixed\\' or venous sample. Delays in analysis and air contamination are common. OBJECTIVES: We measured the effects of these errors in patients with chronic obstructive pulmonary disease (COPD) exacerbations and controls. METHODS: Arterial and venous samples were analyzed from 30 patients with COPD exacerbation and 30 controls. Venous samples were analysed immediately and arterial samples separated into non-air-contaminated and air-contaminated specimens and analysed at 0, 30, 60, 90 and 180 min. RESULTS: Mean venous pH was 7.371 and arterial pH was 7.407 (p < 0.0001). There was a correlation between venous and arterial pH (r = 0.5347, p < 0.0001). The regression equation to predict arterial pH was: arterial pH = 4.2289 + 0.43113 . venous pH. There were no clinically significant differences in arterial PO associated with analysis delay. A statistically significant decline in pH was detected at 30 min in patients with COPD exacerbation (p = 0.0042) and 90 min in controls (p < 0.0001). A clinically significant decline in pH emerged at 73 min in patients with COPD exacerbation and 87 min in controls. Air contamination was associated with a clinically significant increase in PO in all samples, including those that were immediately analyzed. CONCLUSIONS: Arterial and venous pH differ significantly. Venous pH cannot accurately replace arterial pH. Temporal delays in ABG analysis result in a significant decline in measured pH. ABGs should be analysed within 30 min. Air contamination leads to an immediate increase in measured PO, indicating that air-contaminated ABGs should be discarded.

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.

Preoperative sclerotherapy of facial venous malformations: impact on surgical parameters and long-term follow-up.

Science.gov (United States)

James, Charles A; Braswell, Leah E; Wright, Lonnie B; Roberson, Paula K; Moore, Mary B; Waner, Milton; Buckmiller, Lisa M

2011-07-01

To analyze the operative benefit of preoperative sclerotherapy of facial venous malformations and assess long-term patient outcome. Preoperative sclerotherapy was performed in 24 consecutive patients referred before resection of facial venous malformation. Pretreatment imaging was reviewed for malformation dimensions (length, width, and height), and volumes were estimated. Sclerotherapy was performed with 3% sodium tetradecyl in the first 15 patients and 98% dehydrated alcohol in the remaining 9 patients. Operative blood loss, operative time, transfusion requirement, and hospital stay were recorded. Operative time per lesion volume and operative blood loss per lesion volume were calculated. Results were compared with 15 historical control patients who underwent resection of facial venous malformations without preoperative sclerotherapy. Long-term follow-up of study and control patients was performed. Compared with controls, patients undergoing preoperative venous sclerotherapy were significantly older (P = .0206) and had larger lesions in all three dimensions (height, P = .0002; length, P = .0010; width, P = .0004). Patients receiving sclerotherapy had shorter operative time per lesion volume (P lesion volume (P nerve paresis occurred in 8.3% of cases. Long-term follow-up revealed retreatment was required in 2 of 24 patients (8.3%). Preoperative sclerotherapy of venous malformations was associated with less operative time per lesion volume and less operative blood loss per lesion volume. Long-term follow-up revealed a low need for retreatment. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

Central Venous Occlusion in the Hemodialysis Patient.

Science.gov (United States)

Krishna, Vinay Narasimha; Eason, Joseph B; Allon, Michael

2016-11-01

Central venous stenosis (CVS) is encountered frequently among hemodialysis patients. Prior ipsilateral central venous catheterization and cardiac rhythm device insertions are common risk factors, but CVS can also occur in the absence of this history. Chronic CVS can cause thrombosis with partial or complete occlusion of the central vein at the site of stenosis. CVS is frequently asymptomatic and identified as an incidental finding during imaging studies. Symptomatic CVS presents most commonly as an upper- or lower-extremity edema ipsilateral to the CVS. Previously unsuspected CVS may become symptomatic after placement of an ipsilateral vascular access. The likelihood of symptomatic CVS may be affected by the central venous catheter (CVC) location; CVC side; duration of CVC dependence; type, location, and blood flow of the ipsilateral access; and extent of collateral veins. Venous angiography is the gold standard for diagnosis. Percutaneous transluminal angioplasty and stent placement can improve the stenosis and alleviate symptoms, but CVS typically recurs frequently, requiring repeated interventions. Refractory symptomatic CVS may require ligation of the ipsilateral vascular access. Because no available treatment option is curative, the goal should be to prevent CVS by minimizing catheters and central vein instrumentation in patients with chronic kidney disease and dialysis patients. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Investigation of cerebral venous outflow in microgravity.

Science.gov (United States)

Taibi, A; Gadda, G; Gambaccini, M; Menegatti, E; Sisini, F; Zamboni, P

2017-10-31

The gravitational gradient is the major component to face when considering the physiology of venous return, and there is a growing interest in understanding the mechanisms ensuring the heart filling, in the absence of gravity, for astronauts who perform long-term space missions. The purpose of the Drain Brain project was to monitor the cerebral venous outflow of a crew member during an experiment on the International Space Station (ISS), so as to study the compensatory mechanisms that facilitate this essential physiological action in subjects living in a microgravity environment. Such venous function has been characterized by means of a novel application of strain-gauge plethysmography which uses a capacitive sensor. In this contribution, preliminary results of our investigation have been presented. In particular, comparison of plethysmography data confirmed that long duration spaceflights lead to a redistribution of venous blood volume, and showed interesting differences in the amplitude of cardiac oscillations measured at the level of the neck veins. The success of the experiment has also demonstrated that thanks to its easy portability, non-invasiveness, and non-operator dependence, the proposed device can be considered as a novel tool for use aboard the ISS. Further trials are now under way to complete the investigation on the drainage function of the neck veins in microgravity.

Independent association of resting energy expenditure with blood pressure: confirmation in populations of the African diaspora.

Science.gov (United States)

Creber, Chloe; Cooper, Richard S; Plange-Rhule, Jacob; Bovet, Pascal; Lambert, Estelle V; Forrester, Terrence E; Schoeller, Dale; Riesen, Walter; Korte, Wolfgang; Cao, Guichan; Luke, Amy; Dugas, Lara R

2018-01-10

Obesity is a major risk factor for hypertension, however, the physiologic mechanisms linking increased adiposity to elevations in blood pressure are not well described. An increase in resting energy expenditure (REE) is an obligatory consequence of obesity. Previous survey research has demonstrated that REE is an independent predictor of blood pressure, and eliminates the co-linear association of body mass index. This observation has received little attention and there have been no attempts to provide a causal explanation. At baseline in an international comparative study on obesity, 289 participants aged 25-44 were recruited from communities in the US, the Seychelles, Ghana and South Africa and had REE measured with indirect calorimetry. All participants were thought to be free of major illness. In multivariate regression models, both systolic and diastolic blood pressure were positively associated with REE (p < 0.01), while body mass index and fat mass were negatively correlated with systolic blood pressure (p < 0.01, and p < 0.05 respectively), but not diastolic blood pressure. These data confirm previous reports and suggest that a common physiologic abnormality links REE and blood pressure. Elevated catecholamines, a putative metabolic characteristic of obesity, is a possible candidate to explain this association. The direct role of excess adipose tissue is open to question.

The role of central venous oxygen saturation, blood lactate, and central venous-to-arterial carbon dioxide partial pressure difference as a goal and prognosis of sepsis treatment.

Science.gov (United States)

Wittayachamnankul, Borwon; Chentanakij, Boriboon; Sruamsiri, Kamphee; Chattipakorn, Nipon

2016-12-01

The current practice in treatment of severe sepsis and septic shock is to ensure adequate oxygenation and perfusion in patients, along with prompt administration of antibiotics, within 6 hours from diagnosis, which is considered the "golden hour" for the patients. One of the goals of treatment is to restore normal tissue perfusion. With this goal in mind, some parameters have been used to determine the success of treatment and mortality rate; however, none has been proven to be the best predictor of mortality rate in sepsis patients. Despite growing evidence regarding the prognostic indicators for mortality in sepsis patients, inconsistent reports exist. This review comprehensively summarizes the reports regarding the frequently used parameters in sepsis including central venous oxygen saturation, blood lactate, and central venous-to-arterial carbon dioxide partial pressure difference, as prognostic indicators for clinical outcomes in sepsis patients. Moreover, consistent findings and inconsistent reports for their pathophysiology and the potential mechanisms for their use as well as their limitations in sepsis patients are presented and discussed. Finally, a schematic strategy for potential management and benefits in sepsis patients is proposed based upon these current available data. There is currently no ideal biomarker that can indicate prognosis, predict progression of the disease, and guide treatment in sepsis. Further studies are needed to be carried out to identify the ideal biomarker that has all the desired properties. Copyright © 2016 Elsevier Inc. All rights reserved.

DETERMINATION OF AMMONIA IN EAR-LOBE CAPILLARY BLOOD IS AN ALTERNATIVE TO ARTERIAL BLOOD AMMONIA

NARCIS (Netherlands)

HUIZENGA, [No Value; GIPS, CH; CONN, HO; JANSEN, PLM

1995-01-01

Blood ammonia determination is a laboratory test to diagnose hepatic encephalopathy. Arterial blood is superior to peripheral venous blood ammonia because of ammonia metabolism in muscle. We have compared capillary with arterial whole blood ammonia as capillary sampling is an attractive alternative.

Determination of ammonia in ear-lobe capillary blood is an alternative to arterial blood ammonia

NARCIS (Netherlands)

Huizenga, J. R.; Gips, C. H.; Conn, H. O.; Jansen, P. L.

1995-01-01

Blood ammonia determination is a laboratory test to diagnose hepatic encephalopathy. Arterial blood is superior to peripheral venous blood ammonia because of ammonia metabolism in muscle. We have compared capillary with arterial whole blood ammonia as capillary sampling is an attractive alternative.

Effect of acute inspiratory muscle exercise on blood flow of resting and exercising limbs and glucose levels in type 2 diabetes.

Science.gov (United States)

Corrêa, Ana Paula dos Santos; Antunes, Cristiano Fetter; Figueira, Franciele Ramos; de Castro, Marina Axmann; Ribeiro, Jorge Pinto; Schaan, Beatriz D'Agord

2015-01-01

To evaluate the effects of inspiratory loading on blood flow of resting and exercising limbs in patients with diabetic autonomic neuropathy. Ten diabetic patients without cardiovascular autonomic neuropathy (DM), 10 patients with cardiovascular autonomic neuropathy (DM-CAN) and 10 healthy controls (C) were randomly assigned to inspiratory muscle load of 60% or 2% of maximal inspiratory pressure (PImax) for approximately 5 min, while resting calf blood flow (CBF) and exercising forearm blood flow (FBF) were measured. Reactive hyperemia was also evaluated. From the 20 diabetic patients initially allocated, 6 wore a continuous glucose monitoring system to evaluate the glucose levels during these two sessions (2%, placebo or 60%, inspiratory muscle metaboreflex). Mean age was 58 ± 8 years, and mean HbA1c, 7.8% (62 mmol/mol) (DM and DM-CAN). A PImax of 60% caused reduction of CBF in DM-CAN and DM (Pexercise was blunted during 60% of PImax in DM-CAN and DM, and augmented in C (Pexercise that recruits the diaphragm can abruptly reduce glucose levels.

Understanding Blood Pressure Readings

Science.gov (United States)

... Venous Thromboembolism Aortic Aneurysm More Understanding Blood Pressure Readings Updated:Jun 1,2018 What do your blood ... and Live Our Interactive Cardiovascular Library has detailed animations and illustrations to help you learn about conditions, ...

Commercial Hy-Line W-36 pullet and laying hen venous blood gas and chemistry profiles utilizing the portable i-STAT®1 analyzer.

Science.gov (United States)

Schaal, T P; Arango, J; Wolc, A; Brady, J V; Fulton, J E; Rubinoff, I; Ehr, I J; Persia, M E; O'Sullivan, N P

2016-02-01

Venous blood gas and chemistry reference ranges were determined for commercial Hy-Line W-36 pullets and laying hens utilizing the portable i-STAT®1 analyzer and CG8+ cartridges. A total of 632 samples were analyzed from birds between 4 and 110 wk of age. Reference ranges were established for pullets (4 to 15 wk), first cycle laying hens (20 to 68 wk), and second cycle (post molt) laying hens (70 to 110 wk) for the following traits: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iCa mmol/L), glucose (Glu mg/dl), hematocrit (Hct% Packed Cell Volume [PCV]), pH, partial pressure carbon dioxide (PCO2 mm Hg), partial pressure oxygen (PO2 mm Hg), total concentration carbon dioxide (TCO2 mmol/L), bicarbonate (HCO3 mmol/L), base excess (BE mmol/L), oxygen saturation (sO2%), and hemoglobin (Hb g/dl). Data were analyzed using ANOVA to investigate the effect of production status as categorized by bird age. Trait relationships were evaluated by linear correlation and their spectral decomposition. All traits differed significantly among pullets and mature laying hens in both first and second lay cycles. Levels for K, iCa, Hct, pH, TCO2, HCO3, BE, sO2, and Hb differed significantly between first cycle and second cycle laying hens. Many venous blood gas and chemistry parameters were significantly correlated. The first 3 eigenvalues explained ∼2/3 of total variation. The first 2 principal components (PC) explained 51% of the total variation and indicated acid-balance and relationship between blood O2 and CO2. The third PC explained 16% of variation and seems to be related to blood iCa. Establishing reference ranges for pullet and laying hen blood gas and chemistry with the i-STAT®1 handheld unit provides a mechanism to further investigate pullet and layer physiology, evaluate metabolic disturbances, and may potentially serve as a means to select breeder candidates with optimal blood gas or chemistry levels on-farm. © The Author 2015. Published by Oxford University

Repeatability of popliteal blood flow and lower limb vascular conductance at rest and exercise during body tilt using Doppler ultrasound

International Nuclear Information System (INIS)

Villar, R; Hughson, R L

2013-01-01

We tested the data repeatability for popliteal blood flow velocity (PBV), popliteal arterial diameter (AD pop ), popliteal blood flow (PBF) and lower limb vascular conductance (VC) at rest and exercise in three body positions, two work rates and two inspired oxygen fractions. Fifteen, eleven and ten healthy volunteers participated in the three phases of the studies. Resting protocols were performed in horizontal (HOR), 35° head-down tilt (HDT) and 45° head-up tilt (HUT) for 5 min in each body position. Participants also exercised at lower and higher power outputs (repeated plantar flexion contractions at 20% and 30% maximal voluntary contraction, respectively) in HOR, HDT and HUT and in normoxia (21%O 2 ) and hypoxia (14%O 2 ) with the same work rates and body positions. PBV and AD pop were measured by ultrasound to determine PBF, and VC was estimated by dividing PBF by muscle perfusion pressure (MPP). PBV, AD pop , PBF and VC were not different, demonstrated good agreement and consistency between the two days of testing during both rest and exercise conditions regardless of body position. Therefore, these data support the utilization of Doppler and echo Doppler ultrasound as a reproducible method to measure PBV and AD pop and consequently estimate PBF and VC responses in such conditions. (paper)

Effects of long-term head-down-tilt bed rest and different training regimes on the coagulation system of healthy men.

Science.gov (United States)

Haider, Thomas; Gunga, Hanns-Christian; Matteucci-Gothe, Raffaella; Sottara, Elke; Griesmacher, Andrea; Belavý, Daniel L; Felsenberg, Dieter; Werner, Andreas; Schobersberger, Wolfgang

2013-11-01

Immobility plus preexisting chronic disease or acute trauma can activate the coagulation system, thus increasing the risk for thromboembolic events. The effects of long-term bed-rest immobility and microgravity on the coagulation system of healthy persons (e.g., during crewed Mars missions) have not yet been studied. The main objective of the second Berlin BedRest Study (BBR2-2) "Coagulation Part" was to investigate adaptations of the hemostatic system during long-term bed rest (60 days) under simulated microgravity (6° head-down-tilt [6°HDT]) and after mobilization in three different volunteer groups (randomly assigned to CTR= inactive control group; RE= resistive exercise only group; and RVE= resistive exercise with whole-body vibration group). In 24 males (aged 21-45 years), before, during, and after long-term bed rest, key parameters of coagulation were measured from venous blood samples: D-dimer (DD), thrombin-antithrombin III complex (TAT), and prothrombin fragment F1 + 2 (PT-F1 + 2). Additionally, modified rotational thrombelastometry (ROTEM (®) ) analysis was performed. Times of exploratory analyses were as follows: baseline data collection 2 days before bed rest (BDC-2); eight different days of 6°HDT bed rest (HDT1-HDT60), and two different days after reambulation (R + 3 and R + 6). We found significant changes in DD, TAT, and PT-F1 + 2 over the total time course, but no consistent effect of physical interventions (RE, RVE) on these parameters. Notably, no parameter reached levels indicative of intravascular thrombin formation. All ROTEM® parameters remained within the normal range and no pathological traces were found. Sixty days of 6°HDT bed rest are not associated with pronounced activation of the coagulation system indicative of intravascular thrombus formation in healthy volunteers independent of the training type during the bed rest.

Red blood cell rheology in patients with chronic venous disease (CVD)

NARCIS (Netherlands)

Chwała, Maciej; Spannbauer, Anna; Teległów, Aneta; Cencora, Andrzej; Marchewka, Anna; Hardeman, Max R.; Dabrowski, Zbigniew

2009-01-01

Rheological studies concerning aggregation and elongation of erythrocytes were carried out in 21 patients (mean age 56 years) with chronic venous disease (CVD) and 10 (mean age 45 years) healthy control subjects, with the use of a LORCA device. Higher values of parameters characterizing both

Types of Blood Pressure Medications

Science.gov (United States)

... Disease Venous Thromboembolism Aortic Aneurysm More Types of Blood Pressure Medications Updated:Nov 6,2017 Prescription blood pressure ... This content was last reviewed October 2017. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

Regional cerebral blood flow during rest and skilled hand movements by xenon-133 inhalation and emission computerized tomography

DEFF Research Database (Denmark)

Lauritzen, M; Henriksen, L; Lassen, N A

1981-01-01

Regional cerebral blood flow (CBF) was studied in 16 normal adult volunteers during rest and in 10 the study was repeated during skilled hand movements. A fast-rotating ("dynamic"), single-photon emission computerized tomograph (ECT) with four detector heads was used. Xenon-133 was inhaled over a 1...... motor area on both sides by 34 +/- 15% (p less than 0.025)....

L-lysine escinat, thiotriazolin, gordox and mydocalm influence on oxygen tension in the intestinal wall and acid-base balance and limited proteolysis in intestinal venous blood in terms of intraabdominal hypertension modeling

Directory of Open Access Journals (Sweden)

Sapegin V.I.

2014-11-01

Full Text Available In acute experiments on rabbits there were studied changes in oxygen tension in the intestinal wall tissues, acid-base balance and limited proteolysis and its inhibitors in intestinal venous blood, protective action of L-lysine escinat (0,15 mg/kg / single dose, thiotriazolin (25 mg/kg / single dose, aprotinin (gordox (10,000 units/kg / single dose in sequential modeling of standard levels increasing of intra-abdominal hypertension (IAH — 50, 100, 150, 200, 250, 300, 350 m H2O, and also of tolperison (mydocalm (5 mg/kg / single dose on modeling of stable 3-hour IAH 200 m H2O. The IAH modeling was performed by means of stand of our construction. Under the influence of IAH the compensated metabolic acidosis in intestinal venous blood with a compensative hyperpnoe develops, decline of oxygen tension in tissues and activating of a limited proteolysis as well as decline of its inhibitors activity in intestinal venous blood occur. By the degree of metabolic acidosis prevention investigational preparations were distributed as follows gordox > thiotriazolin = L-lysine escinat = mydocalm, and by prevention of decline of oxygen tension in tissues — thiotriazolin > L-lysine escinat > mydocalm > gordox, it is is connected with different rate of methabolic products excretion into the blood, due to the influence on blood circulation and transcapilary exchange. By the degree of prevention of proteolytic activity and inhibitory potential changes, investigational preparations were distributed as follows: gordox > mydocalm > thiotriazolin > L-lysine escinat, this is connected with inhibition of proteolysis in gordox, and in other ones – with reduction of ischemic damage of tissues. Owing to different mechanism of action thiotriazolin, L-lysine escinat and mydocalm may be simultaneously recommended for a conservative treatment of patients with intraabdominal hypertension syndrome.

Effects of blood transfusion on oxygen extraction ratio and central venous saturation in children after cardiac surgery.

Science.gov (United States)

Nasser, Bana; Tageldein, Mohmad; AlMesned, Abdulrahman; Kabbani, Mohammad

2017-01-01

Red blood cell transfusion is common in critically ill children after cardiac surgery. Since the threshold for hemoglobin (Hb) transfusion need is not well defined, the threshold Hb level at which dependent critical oxygen uptake-to-delivery (VO2-DO2) status compensation is uncertain. To assess the effects of blood transfusion on the oxygen extraction ratio (O2ER) and central venous oxygen saturation (ScvO2) to identify a critical O2ER value that could help us determine the critical need for blood transfusion. Prospective, observational cohort study. Cardiac Surgical Intensive Care Unit at Prince Sultan Cardiac Center in Qassim, Saudi Arabia. Between January 2013 and December 2015, we included all children with cardiac disease who underwent surgery and needed a blood transfusion. Demographic and laboratory data with physiological parameters before and 1 and 6 hours after transfusion were recorded and O2ER before and 6 hours after transfusion was computed. Cases were divided into two groups based on O2ER: Patients with increased O2ER (O2ER > 40%) and normal patients without increased O2ER (O2ER transfusion. Changes in O2ER and ScvO2 following blood transfusion. Of 103 patients who had blood transfusion, 75 cases had normal O2ER before transfusion while 28 cases had increased O2ER before transfusion. Following blood transfusion, O2ER and ScvO2 improved in the group that had increased O2ER before transfusion, but not in the group that had normal O2ER before transfusion. The clinical and hemodynamic indicators O2ER and ScvO2 may be considered as markers that can indicate a need for blood transfusion. The limitation of this study is the small number of patients that had increased O2ER before transfusion. There were few available variables to assess oxygen consumption.

Pdgfrb-Cre targets lymphatic endothelial cells of both venous and non-venous origins.

Science.gov (United States)

Ulvmar, Maria H; Martinez-Corral, Ines; Stanczuk, Lukas; Mäkinen, Taija

2016-06-01

The Pdgfrb-Cre line has been used as a tool to specifically target pericytes and vascular smooth muscle cells. Recent studies showed additional targeting of cardiac and mesenteric lymphatic endothelial cells (LECs) by the Pdgfrb-Cre transgene. In the heart, this was suggested to provide evidence for a previously unknown nonvenous source of LECs originating from yolk sac (YS) hemogenic endothelium (HemEC). Here we show that Pdgfrb-Cre does not, however, target YS HemEC or YS-derived erythro-myeloid progenitors (EMPs). Instead, a high proportion of ECs in embryonic blood vessels of multiple organs, as well as venous-derived LECs were targeted. Assessment of temporal Cre activity using the R26-mTmG double reporter suggested recent occurrence of Pdgfrb-Cre recombination in both blood and lymphatic ECs. It thus cannot be excluded that Pdgfrb-Cre mediated targeting of LECs is due to de novo expression of the Pdgfrb-Cre transgene or their previously established venous endothelial origin. Importantly, Pdgfrb-Cre targeting of LECs does not provide evidence for YS HemEC origin of the lymphatic vasculature. Our results highlight the need for careful interpretation of lineage tracing using constitutive Cre lines that cannot discriminate active from historical expression. The early vascular targeting by the Pdgfrb-Cre also warrants consideration for its use in studies of mural cells. genesis 54:350-358, 2016. © 2016 The Authors. Genesis Published by Wiley Periodicals, Inc. © 2016 The Authors. Genesis Published by Wiley Periodicals, Inc.

Splanchnic blood flow and hepatic glucose production in exercising humans

DEFF Research Database (Denmark)

Bergeron, R; Kjaer, M; Simonsen, L

2001-01-01

The study examined the implication of the renin-angiotensin system (RAS) in regulation of splanchnic blood flow and glucose production in exercising humans. Subjects cycled for 40 min at 50% maximal O(2) consumption (VO(2 max)) followed by 30 min at 70% VO(2 max) either with [angiotensin-converti......The study examined the implication of the renin-angiotensin system (RAS) in regulation of splanchnic blood flow and glucose production in exercising humans. Subjects cycled for 40 min at 50% maximal O(2) consumption (VO(2 max)) followed by 30 min at 70% VO(2 max) either with [angiotensin......-converting enzyme (ACE) blockade] or without (control) administration of the ACE inhibitor enalapril (10 mg iv). Splanchnic blood flow was estimated by indocyanine green, and splanchnic substrate exchange was determined by the arteriohepatic venous difference. Exercise led to an approximately 20-fold increase (P ...-blockade group vs. the control group, hormones, metabolites, VO(2), and RER followed the same pattern of changes in ACE-blockade and control groups during exercise. Splanchnic blood flow (at rest: 1.67 +/- 0.12, ACE blockade; 1.59 +/- 0.18 l/min, control) decreased during moderate exercise (0.78 +/- 0.07, ACE...

Reference data for distal blood pressure in healthy elderly and middle-aged individuals measured with the strain gauge technique. Part I: Resting distal blood pressure

DEFF Research Database (Denmark)

Arveschoug, Anne Kirstine; Vammen, Birthe; Yoshinaka, Emmy

2008-01-01

pressure and DBPtoe - DBPankle) were found in the new reference data compared to the old. No significant difference between the mean values of the gradient (DBPankle - systolic arm blood pressure) was found between the old and new reference data, although the variation was significantly wider in the new......Objective. Most patients referred to our department for distal blood pressure (DBP) determination on suspicion of arterial peripheral vascular disease (apvd) are more than 60 years of age, whereas the only available reference data for resting pressure are based on data from healthy individuals aged....... Material and methods. Group I comprised 31 healthy persons aged between 61 and 87 years and group II 14 healthy middle-aged hospital staff members aged between 45 and 58 years. Strict rules of inclusion were followed. Results. For group I, significantly greater gradients (DBPtoe - systolic arm blood...

Regional cerebral blood flow of the patients with schizophrenia. A study using 99mTc-ECD SPECT at rest and activation

International Nuclear Information System (INIS)

Hu Ping; Wu Kening; Zeng Shiquan; Lin Zengtao; Yu Jinlong

1996-01-01

Regional cerebral blood flow (rCBF) changes of the patients with schizophrenia were observed. 99m Tc-ECD SPECT was performed on 22 patients with schizophrenia and 10 healthy volunteers at rest and activation with a cognitive task: a modified Wisconsin Card Sorting Test. At rest state, only 4 patients have abnormal rCBF pattern: left hemisphere over-perfusion relative to the right. A significant relative activation deficit in the left inferior prefrontal region was revealed in the patients during activation. The patients with schizophrenia may have frontal lobe dysfunction

Blood Clotting and Pregnancy

Medline Plus

Full Text Available ... known as venous thromboembolism, are highly preventable (see prevention tips below). The U.S. Surgeon General has issued ... blood conditions and increase research on the causes, prevention, and treatment. Blood clots are also potentially dangerous ...

A Technique for Autologous Priming of the Veno-Venous Bypass Circuit during Liver Transplantation

OpenAIRE

Shackelford, Anthony G.; Hodge, Ashley B.; Chavin, Kenneth D.; Baliga, Prabhakar K.

2011-01-01

Orthotopic liver transplantations (OLT) have been associated with significant blood loss and hemodilution, necessitating significant homologous blood component replacement. Increasing administration of homologous blood products has been found to be inversely related to patient and graft survival. Various methods to reduce the amount of blood products patients receive during OLT, such as antifibrinolytic therapy, thromboelastography-guided transfusion, phlebotomy, reduced central venous pressu...

Resting-state FMRI confounds and cleanup

Science.gov (United States)

Murphy, Kevin; Birn, Rasmus M.; Bandettini, Peter A.

2013-01-01

The goal of resting-state functional magnetic resonance imaging (FMRI) is to investigate the brain’s functional connections by using the temporal similarity between blood oxygenation level dependent (BOLD) signals in different regions of the brain “at rest” as an indicator of synchronous neural activity. Since this measure relies on the temporal correlation of FMRI signal changes between different parts of the brain, any non-neural activity-related process that affects the signals will influence the measure of functional connectivity, yielding spurious results. To understand the sources of these resting-state FMRI confounds, this article describes the origins of the BOLD signal in terms of MR physics and cerebral physiology. Potential confounds arising from motion, cardiac and respiratory cycles, arterial CO2 concentration, blood pressure/cerebral autoregulation, and vasomotion are discussed. Two classes of techniques to remove confounds from resting-state BOLD time series are reviewed: 1) those utilising external recordings of physiology and 2) data-based cleanup methods that only use the resting-state FMRI data itself. Further methods that remove noise from functional connectivity measures at a group level are also discussed. For successful interpretation of resting-state FMRI comparisons and results, noise cleanup is an often over-looked but essential step in the analysis pipeline. PMID:23571418

Detailed examination of the adrenal glands by angiography and radioimmunologic measurement of hormones in adrenal venous blood

International Nuclear Information System (INIS)

Yugrinov, O.G.; Slavnov, V.N.; Komissarenko, I.V.; Olejnik, V.A.; Benikova, E.A.

1984-01-01

In 222 patients the adrenal glands were examined in detail by arteriography and venography, and if indicated also the ovaries, kidneys, bladder and other organs were checked up. Blood samples were taken from the adrenal glands, renal veins and the vena cava inferior in the bifurcational and subdiaphragmatic region. According to the clinical requirements cortisol, corticotropine, aldosterone, adrenaline, noradrenaline and renine activity were determined. Comprehensive angiographic and radioimmunologic studies revealed in 54 patients tumors of the adrenal cortex. Tumors of the adrenal medulla were detected in 43 of the cases. In 103 cases a morbus Icenko-Cushing was found. The basic examination of the diagnostic schedule was selective adrenal venography. Adrenal arteriography and measurement of venous hormone levels were complementary investigations and were rarely used as independent methods. (author)

Severe hypoxemia during veno-venous extracorporeal membrane oxygenation: exploring the limits of extracorporeal respiratory support

Directory of Open Access Journals (Sweden)

Liane Brescovici Nunes

2014-03-01

Full Text Available OBJECTIVE: Veno-venous extracorporeal oxygenation for respiratory support has emerged as a rescue alternative for patients with hypoxemia. However, in some patients with more severe lung injury, extracorporeal support fails to restore arterial oxygenation. Based on four clinical vignettes, the aims of this article were to describe the pathophysiology of this concerning problem and to discuss possibilities for hypoxemia resolution. METHODS: Considering the main reasons and rationale for hypoxemia during veno-venous extracorporeal membrane oxygenation, some possible bedside solutions must be considered: 1 optimization of extracorporeal membrane oxygenation blood flow; 2 identification of recirculation and cannula repositioning if necessary; 3 optimization of residual lung function and consideration of blood transfusion; 4 diagnosis of oxygenator dysfunction and consideration of its replacement; and finally 5 optimization of the ratio of extracorporeal membrane oxygenation blood flow to cardiac output, based on the reduction of cardiac output. CONCLUSION: Therefore, based on the pathophysiology of hypoxemia during veno-venous extracorporeal oxygenation support, we propose a stepwise approach to help guide specific interventions.

A postscript to Circulation of the blood: men and ideas.

Science.gov (United States)

Riley, R L

1982-10-01

Since 1964, when Fishman and Richards published Circulation of the Blood: Men and Ideas, Guyton's model of the circulation, in which mean circulatory pressure serves as the upstream pressure for venous return, has been extended, and the concept of vascular smooth muscle tone acting like the pressure surrounding a Starling resistor has been postulated. According to this scheme, the positive zero flow intercepts of rapidly determined arterial pressure-flow curves are the effective downstream pressures for arterial flow to different tissues. The arterioles, like Starling resistors, determine the downstream pressures and are followed by abrupt pressure drops, or "waterfalls." Capillary pressures are closely linked to those of the venules into which they flow. Capillary-venular pressures are the upstream pressures for venous return. In exercising muscles, reduced arteriolar tone lowers arteriolar pressure and increases arterial flow. This, in turn, raises capillary-venular pressure and increases venous flow. The arteriolar-capillary waterfall is decreased or eliminated. Total blood flow is increased by diversion of blood from tissues with slow venous drainage to muscles with fast venous drainage (low resistance X compliance). The heart pumps away the increased venous return by shifting to a new ventricular function curve.

Venous hemodynamic changes in lower limb venous disease

DEFF Research Database (Denmark)

Lee, Byung Boong; Nicolaides, Andrew N; Myers, Kenneth

2016-01-01

). Their aim was to confirm or dispel long-held hemodynamic principles and to provide a comprehensive review of venous hemodynamic concepts underlying the pathophysiology of lower limb venous disorders, their usefulness for investigating patients and the relevant hemodynamic changes associated with various...... forms of treatment. Chapter 1 is devoted to basic hemodynamic concepts and normal venous physiology. Chapter 2 presents the mechanism and magnitude of hemodynamic changes in acute deep vein thrombosis indicating their pathophysiological and clinical significance. Chapter 3 describes the hemodynamic...... changes that occur in different classes of chronic venous disease and their relation to the anatomic extent of disease in the macrocirculation and microcirculation. The next four chapters (Chapters 4-7) describe the hemodynamic changes resulting from treatment by compression using different materials...

Electrical stimulation of acupoint combinations against deep venous thrombosis in elderly bedridden patients after major surgery.

Science.gov (United States)

Hou, Lili; Chen, Cuiping; Xu, Lei; Yin, Peihao; Peng, Wen

2013-04-01

To compare the effects of electrical stimulation of different acupoint combinations among postoperative bedridden elderly patients on hemorheology and deep venous blood flow velocity and investigate the.role of electrical stimulation against deep vein thrombosis (DVT). From November 2010 to October 2011, a total of 160 elderly bedridden patients after major surgery were divided into the conventional care group, invigorating and promoting Qi group, blood-activating and damp-eliminating group, and acupoint-combination stimulation group. Whole blood viscosity, plasma viscosity, D-dimer levels, lower limb skin temperature, lower limb circumference, and flow velocities of the external iliac vein, femoral vein, popliteal vein, and deep calf veins in all patients were documented and compared among the four groups. Whole blood viscosity, plasma viscosity, D-dimer levels, and lower limb circumference were significantly reduced in the blood-activating and damp-eliminating group compared with the conventional care group (P 0.05). Lower limb venous flow velocities were accelerated in the invigorating and promoting Qi group compared with the other groups, excluding the acupoint-combination stimulation group (P bedridden elderly patients were improved after combined electrical stimulation at Yinlingquan (SP 9) and Sanyinjiao (SP 6). Combined electrical stimulation at Zusanli (ST 36) and Taichong (LR 3), on the other hand, accelerated lower limb venous flow.

Blood venous sample collection: Recommendations overview and a checklist to improve quality.

Science.gov (United States)

Giavarina, Davide; Lippi, Giuseppe

2017-07-01

The extra-analytical phases of the total testing process have substantial impact on managed care, as well as an inherent high risk of vulnerability to errors which is often greater than that of the analytical phase. The collection of biological samples is a crucial preanalytical activity. Problems or errors occurring shortly before, or soon after, this preanalytical step may impair sample quality and characteristics, or else modify the final results of testing. The standardization of fasting requirements, rest, patient position and psychological state of the patient are therefore crucial for mitigating the impact of preanalytical variability. Moreover, the quality of materials used for collecting specimens, along with their compatibility, can guarantee sample quality and persistence of chemical and physical characteristics of the analytes over time, so safeguarding the reliability of testing. Appropriate techniques and sampling procedures are effective to prevent problems such as hemolysis, undue clotting in the blood tube, draw of insufficient sample volume and modification of analyte concentration. An accurate identification of both patient and blood samples is a key priority as for other healthcare activities. Good laboratory practice and appropriate training of operators, by specifically targeting collection of biological samples, blood in particular, may greatly improve this issue, thus lowering the risk of errors and their adverse clinical consequences. The implementation of a simple and rapid check-list, including verification of blood collection devices, patient preparation and sampling techniques, was found to be effective for enhancing sample quality and reducing some preanalytical errors associated with these procedures. The use of this tool, along with implementation of objective and standardized systems for detecting non-conformities related to unsuitable samples, can be helpful for standardizing preanalytical activities and improving the quality of

Effects of aerobic training intensity on resting, exercise and post-exercise blood pressure, heart rate and heart-rate variability.

Science.gov (United States)

Cornelissen, V A; Verheyden, B; Aubert, A E; Fagard, R H

2010-03-01

We aimed to investigate the effects of endurance training intensity (1) on systolic blood pressure (SBP) and heart rate (HR) at rest before exercise, and during and after a maximal exercise test; and (2) on measures of HR variability at rest before exercise and during recovery from the exercise test, in at least 55-year-old healthy sedentary men and women. A randomized crossover study comprising three 10-week periods was performed. In the first and third period, participants exercised at lower or higher intensity (33% or 66% of HR reserve) in random order, with a sedentary period in between. Training programmes were identical except for intensity, and were performed under supervision thrice for 1 h per week. The results show that in the three conditions, that is, at rest before exercise, during exercise and during recovery, we found endurance training at lower and higher intensity to reduce SBP significantly (Pendurance training did not affect the response of SBP after an acute bout of exercise. The effect of training on HR at rest, during exercise and recovery was more pronounced (Pendurance training had no significant effect on sympathovagal balance. In conclusion, in participants at higher age, both training programmes exert similar effects on SBP at rest, during exercise and during post-exercise recovery, whereas the effects on HR are more pronounced after higher intensity training.

Use of Capillary Blood Samples Leads to Higher Parasitemia Estimates and Higher Diagnostic Sensitivity of Microscopic and Molecular Diagnostics of Malaria than Venous Blood Samples.

Science.gov (United States)

Mischlinger, Johannes; Pitzinger, Paul; Veletzky, Luzia; Groger, Mirjam; Zoleko-Manego, Rella; Adegnika, Ayola A; Agnandji, Selidji T; Lell, Bertrand; Kremsner, Peter G; Tannich, Egbert; Mombo-Ngoma, Ghyslain; Mordmüller, Benjamin; Ramharter, Michael

2018-05-25

Diagnosis of malaria is usually based on samples of peripheral blood. However, it is unclear whether capillary (CAP) or venous (VEN) blood samples provide better diagnostic performance. Quantitative differences of parasitemia between CAP and VEN blood and diagnostic performance characteristics were investigated. Patients were recruited between September 2015 and February 2016 in Gabon. Light microscopy and qPCR quantified parasitemia of paired CAP and VEN samples, whose preparation followed the exact same methodology. CAP and VEN performance characteristics using microscopy were evaluated against a qPCR gold-standard. Microscopy revealed a median (IQR) parasites/L of 495 (853,243) in CAP and 429 (524,074) in VEN samples manifesting in a +16.6% (p=0.04) higher CAPparasitemia compared with VENparasitemia. Concordantly, qPCR demonstrated that -0.278 (p=0.006) cycles were required for signal detection in CAP samples. CAPsensitivity of microscopy relative to the gold-standard was 81.5% (77.485.6%) versus VENsensitivity of 73.4% (68.878.1%), while CAPspecificity and VENspecificity were 91%. CAPsensitivity and VENsensitivity dropped to 63.3% and 45.9%, respectively for a sub-population of low-level parasitemias while specificities were 92%. CAP sampling leads to higher parasitemias compared to VEN sampling and improves diagnostic sensitivity. These findings may have important implications for routine diagnostics, research and elimination campaigns of malaria.

Hemodynamic variables during exercise in childhood and resting systolic blood pressure levels 6 years later in adolescence: the European Youth Heart Study

DEFF Research Database (Denmark)

Grøntved, Anders; Andresen, Brage Storstein; Møller, N C

2011-01-01

of Danish children followed longitudinally for 6 years. The study comprised 226 children randomly sampled at age 9, who had their blood pressure and HR measured during ergometer exercise to exhaustion and was reassessed in adolescence. SBP and RPP during exercise in stage two of the test were positively......The aim of this study was to analyze whether systolic blood pressure (SBP), heart rate (HR) and rate pressure product (RPP) during exercise in childhood can predict resting SBP levels in adolescence independent of resting SBP and conventional cardiovascular risk factors. We studied this in a sample...... remained significant (P=0.059 and P=0.012, respectively). No significant independent associations were observed for HR during exercise, but associations were in the same direction. Our results supports that measuring SBP and RPP, during a standard acute ergometer exercise test in children, improves...

Involvement of pterygoid venous plexus in patulous eustachian tube symptoms.

Science.gov (United States)

Oshima, Takeshi; Ogura, Masaki; Kikuchi, Toshiaki; Hori, Yoko; Mugikura, Shunji; Higano, Shuichi; Takahashi, Shoki; Kawase, Tetsuaki; Kobayashi, Toshimitsu

2007-07-01

The pterygoid venous plexus (PVP) is an important factor in the mechanism of eustachian tube (ET) closure under conditions that can cause increased venous pressure in the head, such as during neck compression and postural change from the sitting/standing to the recumbent position. The symptoms of patulous ET are usually improved by neck compression or postural change (from sitting/standing to recumbent position). Venous congestion around the ET and/or gravitational change may be involved in the changing degree of symptoms, but its mechanism is not understood. This study investigated whether the PVP is involved. The dimensions of soft tissues surrounding ET were measured on magnetic resonance images before and after neck compression. The lateral pterygoid muscle became enlarged after neck compression. Simultaneously, the volume of venous plexus observed between the medial pterygoid muscle and tensor veli palatini muscle was increased. Such enlargement was probably due to blood pooling in the PVP, resulting in protrusion of the ET anterior wall to the luminal side, and decreased ET patency.

Plasma volume changes during hypoglycaemia: the effect of arterial blood sampling

DEFF Research Database (Denmark)

Hilsted, J; Bendtsen, Flemming; 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...... hypoglycaemia. The magnitude of the changes in arterial and venous blood were not significantly different. These results indicate that the above changes in blood volume and composition are whole-body phenomena: furthermore, the major part of the changes are likely to occur in tissues other than upper extremity...... 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...

Commercial Hy-Line W-36 pullet and laying hen venous blood gas and chemistry profiles utilizing the portable i-STAT?1 analyzer

OpenAIRE

Schaal, T. P.; Arango, J.; Wolc, A.; Brady, J. V.; Fulton, J. E.; Rubinoff, I.; Ehr, I. J.; Persia, M. E.; O'Sullivan, N. P.

2015-01-01

Venous blood gas and chemistry reference ranges were determined for commercial Hy-Line W-36 pullets and laying hens utilizing the portable i-STAT?1 analyzer and CG8+ cartridges. A total of 632 samples were analyzed from birds between 4 and 110 wk of age. Reference ranges were established for pullets (4 to 15 wk), first cycle laying hens (20 to 68 wk), and second cycle (post molt) laying hens (70 to 110 wk) for the following traits: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iC...

Validation of transit-time flowmetry for chronic measurements of regional blood flow in resting and exercising rats

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S.L. Amaral

1997-07-01

Full Text Available The objective of the present study was to validate the transit-time technique for long-term measurements of iliac and renal blood flow in rats. Flow measured with ultrasonic probes was confirmed ex vivo using excised arteries perfused at varying flow rates. An implanted 1-mm probe reproduced with accuracy different patterns of flow relative to pressure in freely moving rats and accurately quantitated the resting iliac flow value (on average 10.43 ± 0.99 ml/min or 2.78 ± 0.3 ml min-1 100 g body weight-1. The measurements were stable over an experimental period of one week but were affected by probe size (resting flows were underestimated by 57% with a 2-mm probe when compared with a 1-mm probe and by anesthesia (in the same rats, iliac flow was reduced by 50-60% when compared to the conscious state. Instantaneous changes of iliac and renal flow during exercise and recovery were accurately measured by the transit-time technique. Iliac flow increased instantaneously at the beginning of mild exercise (from 12.03 ± 1.06 to 25.55 ± 3.89 ml/min at 15 s and showed a smaller increase when exercise intensity increased further, reaching a plateau of 38.43 ± 1.92 ml/min at the 4th min of moderate exercise intensity. In contrast, exercise-induced reduction of renal flow was smaller and slower, with 18% and 25% decreases at mild and moderate exercise intensities. Our data indicate that transit-time flowmetry is a reliable method for long-term and continuous measurements of regional blood flow at rest and can be used to quantitate the dynamic flow changes that characterize exercise and recovery

Interventional radiology in the provision and maintenance of long-term central venous access

International Nuclear Information System (INIS)

Lyon, S.M.; Given, M.; Marshall, N.L.

2008-01-01

Establishing and maintaining venous access forms an increasing proportion of the workload in interventional radiology. Several patient groups require medium-term to long-term venous catheters for a variety of purposes, including chemotherapy, long-term antimicrobials, parenteral nutrition, short-term access for haemodialysis or exhausted haemodialysis. Often, these catheters are required for treatment and frequent blood testing, which can quickly exhaust the peripheral veins. Venous access devices include implantable catheters (ports), tunnelled catheters and peripherally inserted central catheters, which have different functions, advantages and limitations. Imaging-guided placement is the preferred method of insertion in many institutions because of higher success rates and radiologists are well suited to address catheter complications.

Cerebral venous system and anatomical predisposition to high-altitude headache

NARCIS (Netherlands)

Wilson, Mark H.; Davagnanam, Indran; Holland, Graeme; Dattani, Raj S.; Tamm, Alexander; Hirani, Shashivadan P.; Kolfschoten, Nicky; Strycharczuk, Lisa; Green, Cathy; Thornton, John S.; Wright, Alex; Edsell, Mark; Kitchen, Neil D.; Sharp, David J.; Ham, Timothy E.; Murray, Andrew; Holloway, Cameron J.; Clarke, Kieran; Grocott, Mike P. W.; Montgomery, Hugh; Imray, Chris; Ahuja, V.; Aref-Adib, G.; Burnham, R.; Chisholm, A.; Clarke, K.; Coates, D.; Coates, M.; Cook, D.; Cox, M.; Dhillon, S.; Dougall, C.; Doyle, P.; Duncan, P.; Edsell, M.; Edwards, L.; Evans, L.; Gardiner, P.; Grocott, M.; Gunning, P.; Hart, N.; Harrington, J.; Harvey, J.; Holloway, C.; Howard, D.; Hurlbut, D.; Imray, C.; Ince, C.; Jonas, M.; van der Kaaij, J.

2013-01-01

As inspired oxygen availability falls with ascent to altitude, some individuals develop high-altitude headache (HAH). We postulated that HAH results when hypoxia-associated increases in cerebral blood flow occur in the context of restricted venous drainage, and is worsened when cerebral compliance

Effect of cerebral blood flow on consciousness and outcome after head injury. Assessment by jugular bulb venous metabolism and IMP-SPECT

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Imaizumi, Shigeki; Onuma, Takehide; Motohashi, Osamu; Kameyama, Motonobu; Ishii, Kiyoshi [Sendai City Hospital (Japan)

2002-10-01

This study was performed to elucidate the therapeutical value of arteriojugularvenous oxygen difference (AVDO{sub 2}) in the ultra-emergent period after head injury. Rational therapeutic strategy after severe head injury needs information concerning the dynamical change of cerebral blood flow (CBF) and metabolism. We monitored the cerebral venous metabolism within 6 hours after head injury until the day IMP-SPECT was performed. Whole brain cerebral blood flow detected by IMP-SPECT and AVDO{sub 2} at the same day was compared, which restored to the period within 6 hours after head injury. From this procedure, we could outline cerebral blood flow conditions by only AVDO{sub 2} without IMP-SPECT in the ultra-emergent period. Eighty-six patients with head injury who were carried to our emergency center in the period of recent 2 years aged ranging from 15 to 94 years were the subjects. They all performed jugular bulb cannulation within 6 hours after the accident (Martin's phase I: day 0) to know saturation of jugular vein (SjO{sub 2}), AVDO{sub 2} and AVL. They were monitored until the day IMP-SPECT was performed (Martin's phase II; day 1-3 or phase III; day 4-15). The correlation between CBF and AVDO{sub 2}. The effect of CBF and cerebral venous metabolism on consciousness and outcome was also analyzed. CBF and AVDO{sub 2} in phase II and III were reversely correlated (p<0.0001). Normal CBF corresponded with 5.0 vol% in AVDO{sub 2}. AVDO{sub 2} in all cases changed 6.2 vol% at phase I, 4.5 vol% at phase II and 5.1 vol% at phase III. Glasgow comascale (GCS) on admission under 8 (n=47) and over 9 (n=39) significantly differed in AVDO{sub 2} and CBF in the period of II and III. The patients with favorable consciousness showed low AVDO{sub 2} and hyperemia afterwards. Dead cases in phase I (n=19) showed high AVDO{sub 2} and low SjO{sub 2}. The patients with severe disability (SD) (n=13) showed high AVDO{sub 2} and low CBF and the patients with good recovery (GR

Direct venous thrombolysis and venous angioplasty in the upper extremity

International Nuclear Information System (INIS)

Hollmann, J.P.; Guenther, R.W.

1987-01-01

Venous thromboses of stenoses in the upper extremity are often the result of a compression syndrome of the shoulder girdle, the Paget-von Schroetter syndrome, vascular surgery, space-occupying lesions in the mediastinum or the result of catheterisation. Direct venous thrombolysis and venous angioplasty were performed successfully in six patients. (orig.) [de

Analysis of the vertebral venous system in relation to cerebral venous drainage on MR angiography

International Nuclear Information System (INIS)

Baik, Seung Kug; Sohn, Chul Ho; Kim, Gab Chul; Kim, Yong Sun

2004-01-01

In the supine position, cerebral venous drainage occurs primarily through the internal jugular veins, as seen on venous phase cerebral angiography. However, in the erect position, the vertebral venous system represents the major alternative pathway of cerebral venous drainage, while outflow through the internal jugular veins is absent or negligible. The purpose of this study is to evaluate the vertebral venous system and its relationship between the surrounding venous structures using magnetic resonance angiography (MRA) in the case of subjects in the supine position. We retrospectively reviewed the results of 65 patients (M:F = 31: 34, mean age 61.6 years) who underwent multi-phase contrast-enhanced carotid MRA. The imaging studies were performed using a 3.0 T MR unit (TR: 5.2, TE: 1.1, FA: 20, 3.8 thickness, EC: 1). We analyzed the appearance and extent of the vertebral venous system (vertebral venous plexus and vertebral artery venous plexus) and the internal jugular vein on the venous phase images. We also evaluated the main drainage pattern of the cerebral venous drainage and the drainage pattern of the vertebral venous system. The visualized vertebral venous system was defined as either poor, vertebral venous plexus dominant, vertebral artery venous plexus dominant or mixed. In the vertebral venous system, the vertebral artery venous plexus was visualized in 54 cases (83%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 39 cases (72%) and asymmetrical in 15 cases (28%). The extent of the visualized vertebral artery venous plexus was partial in 26 cases (48%) and complete in 28 cases (52%). The vertebral venous plexus was visualized in 62 cases (95%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 43 cases (69%) and asymmetrical in 19 cases (31%). The extent of the visualized vertebral artery venous plexus was partial in 35 cases (56%) and complete in 27 cases (44%). The appearance of the

Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans

Science.gov (United States)

Cui, Jian; McQuillan, Patrick M.; Blaha, Cheryl; Kunselman, Allen R.

2012-01-01

We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects. PMID:22707559

Regional cerebral blood flow in mood disorders. I. Comparison of major depressives and normal controls at rest

International Nuclear Information System (INIS)

Sackeim, H.A.; Prohovnik, I.; Moeller, J.R.; Brown, R.P.; Apter, S.; Prudic, J.; Devanand, D.P.; Mukherjee, S.

1990-01-01

We measured regional cerebral blood flow with the xenon 133 inhalation technique in 41 patients with major depressive disorder and 40 matched, normal controls during an eyes-closed, resting condition. The depressed group had a marked reduction in global cortical blood flow. To examine topographic abnormalities, traditional multivariate analyses were applied, as well as a new scaled subprofile model developed to identify abnormal functional neural networks in clinical samples. Both approaches indicated that the depressed sample had an abnormality in topographic distribution of blood flow, in addition to the global deficit. The scaled subprofile model identified the topographic abnormality as being due to flow reduction in the depressed patients in selective frontal, central, superior temporal, and anterior parietal regions. This pattern may reflect dysfunction in the parallel distributed cortical network involving frontal and temporoparietal polymodal association areas. The extent of this topographic abnormality, as revealed by the scaled subprofile model, was associated with both patient age and severity of depressive symptoms

A technique for autologous priming of the veno-venous bypass circuit during liver transplantation.

Science.gov (United States)

Shackelford, Anthony G; Hodge, Ashley B; Chavin, Kenneth D; Baliga, Prabhakar K

2011-06-01

Orthotopic liver transplantations (OLT) have been associated with significant blood loss and hemodilution, necessitating significant homologous blood component replacement. Increasing administration of homologous blood products has been found to be inversely related to patient and graft survival. Various methods to reduce the amount of blood products patients receive during OLT, such as antifibrinolytic therapy, thromboelastography-guided transfusion, phlebotomy, reduced central venous pressures intraoperatively, and the use of the veno-venous bypass (VVB) circuit, have been explored.The asanguineous priming volume of the VVB circuit increases the likelihood of the patient receiving homologous blood products due to hemodilution. It was reasoned that autologous priming of the VVB circuit in OLT surgery was a plausible adjunctive blood conservation technique given its application to the extracorporeal circuit during cardiac surgery. We describe our technique of modifying the VVB circuit for autologous priming. This technique adds minimal risk and a small amount of cost to the procedure, requires slightly more communication among members of the surgical team, and with proper sequencing, adds no additional length to the surgical procedure. It is recommended that this technique be considered for addition to the arsenal of blood conservation techniques when VVB is used during OLT.

Optoacoustic monitoring of central and peripheral venous oxygenation during simulated hemorrhage

Science.gov (United States)

Petrov, Andrey; Kinsky, Michael; Prough, Donald S.; Petrov, Yuriy; Petrov, Irene Y.; Henkel, S. Nan; Seeton, Roger; Salter, Michael G.; Khan, Muzna N.; Esenaliev, Rinat O.

2014-03-01

Circulatory shock may be fatal unless promptly recognized and treated. The most commonly used indicators of shock (hypotension and tachycardia) lack sensitivity and specificity. In the initial stages of shock, the body compensates by reducing blood flow to the peripheral (skin, muscle, etc.) circulation in order to preserve vital organ (brain, heart, liver) perfusion. Characteristically, this can be observed by a greater reduction in peripheral venous oxygenation (for instance, the axillary vein) compared to central venous oxygenation (the internal jugular vein). While invasive measurements of oxygenation are accurate, they lack practicality and are not without complications. We have developed a novel optoacoustic system that noninvasively determines oxygenation in specific veins. In order to test this application, we used lower body negative pressure (LBNP) system, which simulates hemorrhage by exerting a variable amount of suction on the lower body, thereby reducing the volume of blood available for central circulation. Restoration of normal blood flow occurs promptly upon cessation of LBNP. Using two optoacoustic probes, guided by ultrasound imaging, we simultaneously monitored oxygenation in the axillary and internal jugular veins (IJV). LBNP began at -20 mmHg, thereafter was reduced in a step-wise fashion (up to 30 min). The optoacoustically measured axillary oxygenation decreased with LBNP, whereas IJV oxygenation remained relatively constant. These results indicate that our optoacoustic system may provide safe and rapid measurement of peripheral and central venous oxygenation and diagnosis of shock with high specificity and sensitivity.

Effect of oral acetyl L-carnitine arginate on resting and postprandial blood biomarkers in pre-diabetics

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Tucker Patrick S

2009-06-01

Full Text Available Abstract Background Resting and postprandial oxidative stress is elevated in those with metabolic disorders such as diabetes. Antioxidant supplementation may attenuate the rise in oxidative stress following feeding. Therefore we sought to determine the effects of acetyl L-carnitine arginate (ALCA on resting and postprandial biomarkers of glucose and lipid metabolism, as well as oxidative stress. Methods Twenty-nine pre-diabetic men and women were randomly assigned to either 3 g·day-1 of ALCA (n = 14; 31 ± 3 yrs or placebo (n = 15; 35 ± 3 yrs in a double-blind design, to consume for eight weeks. Fasting blood samples were taken from subjects both pre and post intervention. After each fasting sample was obtained, subjects consumed a high fat, high carbohydrate meal and additional blood samples were taken at 1, 2, 4, and 6 hours post meal. Samples were analyzed for a variety of metabolic variables (e.g., glucose, HbA1c, lipid panel, C-reactive protein, nitrate/nitrite, and several markers of oxidative stress. Area under the curve (AUC was calculated for each variable measured post meal, both pre and post intervention. Results ALCA, but not placebo, resulted in an increase in nitrate/nitrite (25.4 ± 1.9 to 30.1 ± 2.8 μmol·L-1 from pre to post intervention, with post intervention values greater compared to placebo (p = 0.01. No other changes of statistical significance were noted (p > 0.05, although ALCA resulted in slight improvements in glucose (109 ± 5 to 103 ± 5 mg·dL-1, HbA1c (6.6 ± 1.1 to 6.2 ± 1.2%, and HOMA-IR (3.3 ± 1.3 to 2.9 ± 1.2. AUC postprandial data were not statistically different between ALCA and placebo for any variable (p > 0.05. However, nitrate/nitrite demonstrated a moderate effect size (r = 0.35 for increase from pre (139.50 ± 18.35 μmol·L-1·6 hr-1 to post (172.40 ± 21.75 μmol·L-1·6 hr-1 intervention with ALCA, and the magnitude of decrease following feeding was not as pronounced as with placebo

The Need of Slanted Side Holes for Venous Cannulae

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Joong Yull Park

2012-01-01

Full Text Available Well-designed cannulae must allow good flow rate and minimize nonphysiologic load. Venous cannulae generally have side holes to prevent the rupture of blood vessel during perfusion. Optimizing side hole angle will yield more efficient and safe venous cannulae. A numerical modeling was used to study the effect of the angle (0°–45° and number (0–12 of side holes on the performance of cannulae. By only slanting the side holes, it increases the flow rate up to 6% (in our models. In addition, it was found that increasing the number of side holes reduces the shear rate up to 12% (in our models. A new parameter called “penetration depth” was introduced to describe the interfering effect of stream jets from side holes, and the result showed that the 45°-slanted side holes caused minimum interfering for the flow in cannula. Our quantitative hemodynamic analysis study provides important guidelines for venous cannulae design.

Elevated plasma factor VIII enhances venous thrombus formation in rabbits: contribution of factor XI, von Willebrand factor and tissue factor.

Science.gov (United States)

Sugita, Chihiro; Yamashita, Atsushi; Matsuura, Yunosuke; Iwakiri, Takashi; Okuyama, Nozomi; Matsuda, Shuntaro; Matsumoto, Tomoko; Inoue, Osamu; Harada, Aya; Kitazawa, Takehisa; Hattori, Kunihiro; Shima, Midori; Asada, Yujiro

2013-07-01

Elevated plasma levels of factor VIII (FVIII) are associated with increased risk of deep venous thrombosis. The aim of this study is to elucidate how elevated FVIII levels affect venous thrombus formation and propagation in vivo. We examined rabbit plasma FVIII activity, plasma thrombin generation, whole blood coagulation, platelet aggregation and venous wall thrombogenicity before and one hour after an intravenous infusion of recombinant human FVIII (rFVIII). Venous thrombus induced by the endothelial denudation of rabbit jugular veins was histologically assessed. Thrombus propagation was evaluated as indocyanine green fluorescence intensity. Argatroban, a thrombin inhibitor, and neutralised antibodies for tissue factor (TF), factor XI (FXI), and von Willebrand factor (VWF) were infused before or after thrombus induction to investigate their effects on venous thrombus formation or propagation. Recombinant FVIII (100 IU/kg) increased rabbit plasma FVIII activity two-fold and significantly enhanced whole blood coagulation and total plasma thrombin generation, but did not affect initial thrombin generation time, platelet aggregation and venous wall thrombogenicity. The rFVIII infusion also increased the size of venous thrombus 1 hour after thrombus induction. Argatroban and the antibodies for TF, FXI or VWF inhibited such enhanced thrombus formation and all except TF suppressed thrombus propagation. In conclusion, elevated plasma FVIII levels enhance venous thrombus formation and propagation. Excess thrombin generation by FXI and VWF-mediated FVIII recruitment appear to contribute to the growth of FVIII-driven venous thrombus.

Glucose kinetics in gluconeogenesis-inhibited rats during rest and exercise

International Nuclear Information System (INIS)

Turcotte, L.P.; Rovner, A.S.; Roark, R.R.; Brooks, G.A.

1990-01-01

To evaluate the role played by gluconeogenesis in blood glucose homeostasis, female Sprague-Dawley rats were injected with mercaptopicolinic acid (MPA), a gluconeogenic inhibitor. Glucose kinetics were assessed by primed, continuous infusion of [U-14C]- and [6(-3)H]glucose via an indwelling jugular catheter at rest and during submaximal exercise at 13.4 m/min on level grade. Blood samples were taken from carotid catheters and analyzed for glucose and lactate concentrations and specific activities. Tissue glycogen samples were obtained from rats after exercise as well as from unexercised animals. When compared with the sham-injected animals, MPA-treated animals had 22% lower (5.92 +/- 0.36 vs. 7.62 +/- 0.21 mM) and 44% higher (1.90 +/- 0.11 vs. 1.32 +/- 0.09 mM) resting arterial glucose and lactate concentrations, respectively. Resting glucose appearance (Ra) rates were 20% lower in the MPA-treated animals (57.2 +/- 7.5 mumol.kg-1.min-1) than in the sham-injected animals (71.1 +/- 12.1 mumol.kg-1.min-1). During exercise, Ra increased to 174.7 +/- 32.8 mumol.kg-1.min-1 in sham-injected animals. In the MPA-treated animals, there was a 35% increase during the first 15 min of exercise, followed by a decrease to the resting values. MPA-treated animals had no measurable glucose recycling at rest or during exercise. Exercise decreased blood glucose concentration (35%) and increased blood lactate concentration (160%) in the MPA-treated animals. Exercising sham-injected animals had increased blood glucose (9.8%) but no change in blood lactate concentration. Moderate depletions in liver and skeletal muscle glycogen contents were observed after exercise

Endothelial function after 10 days of bed rest in individuals at risk for type 2 diabetes and cardiovascular disease

DEFF Research Database (Denmark)

Sonne, Mette Paulii; Højbjerre, Lise; Alibegovic, Amra C

2011-01-01

Aims: Physical inactivity is considered to be deleterious to vascular health, and in particular first degree relatives to patients with type 2 diabetes (FDR) and persons born with low birth weight (LBW) who may later in life develop cardiovascular disease. A period of imposed physical inactivity...... could unmask this risk. We hypothesized that the impact of physical inactivity on endothelial function would be more marked in subjects at increased risk for type 2 diabetes and cardiovascular disease, (LBW and FDR) compared with a matched control group (CON); all recruited via advertisements and via...... the Danish Birth Registry.Methods and Results: Twenty LBW and twenty CON and thirteen FDR were studied before and after ten days of bed rest. Forearm blood flow (FBF) was measured by venous occlusion plethysmography during brachial intra-arterial infusions of acetylcholine and adenosine at baseline...

Influence of intranasal and carotid cooling on cerebral temperature balance and oxygenation

DEFF Research Database (Denmark)

Nybo, Lars; Wanscher, Michael; Secher, Niels H.

2014-01-01

temperatures were measured to assess the cerebral heat balance and corresponding paired blood samples were obtained to evaluate cerebral metabolism and oxygenation at rest, following 60 min of intranasal cooling, 5 min of nasal ventilation, and 15 min with carotid cooling. Intranasal cooling induced a parallel......The present study evaluated the influence of intranasal cooling with balloon catheters, increased nasal ventilation, or percutaneous cooling of the carotid arteries on cerebral temperature balance and oxygenation in six healthy male subjects. Aortic arch and internal jugular venous blood...... drop in jugular venous and arterial blood temperatures by 0.30 ± 0.08°C (mean ± SD), whereas nasal ventilation and carotid cooling failed to lower the jugular venous blood temperature. The magnitude of the arterio-venous temperature difference across the brain remained unchanged at -0.33 ± 0.05°C...

Common High Blood Pressure Myths

Science.gov (United States)

... Disease Venous Thromboembolism Aortic Aneurysm More Common High Blood Pressure Myths Updated:May 4,2018 Knowing the facts ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

Blood Pressure vs. Heart Rate

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... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Nov 13,2017 ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

Arterial and venous plasma levels of bupivacaine following epidural and intercostal nerve blocks.

Science.gov (United States)

Moore, D C; Mather, L E; Bridenbaugh, P O; Bridenbaugh, L D; Balfour, R I; Lysons, D F; Horton, W G

1976-07-01

Arterial and peripheral venous plasma levels of bupivacaine were determined in 30 patients following epidural anesthesia using 150 and 225 mg, as well as following intercostal nerve block with 400 mg. Arterial levels were consistently higher than levels in simultaneously sampled venous blood, and the highest levels occurred with bilateral intercostal nerve block. No evidence of systemic toxicity was observed. The results suggest that bupivacaine may have a wider margin of safety in man than is now stated.

Multilocus analyses of renin-angiotensin-aldosterone system gene variants on blood pressure at rest and during behavioral stress in young normotensive subjects

NARCIS (Netherlands)

Ge, Dongliang; Zhu, Haidong; Huang, Ying; Treiber, Frank A.; Harshfield, Gregory A.; Snieder, Harold; Dong, Yanbin

The renin-angiotensin-aldosterone system (RAAS) is a proteolytic cascade that regulates and maintains blood pressure (BP). This study aimed to explore the interactive and integrative effects of multiple RAAS polymorphisms on BP at rest and during behavioral stress in a normotensive population. A

Two divergent paths: compression vs. non-compression in deep venous thrombosis and post thrombotic syndrome

Directory of Open Access Journals (Sweden)

Eduardo Simões Da Matta

Full Text Available Abstract Use of compression therapy to reduce the incidence of postthrombotic syndrome among patients with deep venous thrombosis is a controversial subject and there is no consensus on use of elastic versus inelastic compression, or on the levels and duration of compression. Inelastic devices with a higher static stiffness index, combine relatively small and comfortable pressure at rest with pressure while standing strong enough to restore the “valve mechanism” generated by plantar flexion and dorsiflexion of the foot. Since the static stiffness index is dependent on the rigidity of the compression system and the muscle strength within the bandaged area, improvement of muscle mass with muscle-strengthening programs and endurance training should be encouraged. Therefore, in the acute phase of deep venous thrombosis events, anticoagulation combined with inelastic compression therapy can reduce the extension of the thrombus. Notwithstanding, prospective studies evaluating the effectiveness of inelastic therapy in deep venous thrombosis and post-thrombotic syndrome are needed.

Correlation between arterial blood gas analysis and peripheral blood gas analysis in acid-base unbalance state

Directory of Open Access Journals (Sweden)

Hyun Lee Kim

2012-06-01

Full Text Available Acid-base unbalance is most common problem in severe ill patient, especially in condition of abnormal renal function state. Acid-base unbalances are respiratory acidosis, respiratory alkalosis, metabolic acidosis, and metabolic alkalosis. Metabolic acidosis is frequently appeared in clinical state. Arterial blood gas analysis is considered as a basic test to the intensive care unit patient and emergency state. Recently some researches were done, comparing with arterial blood gas analysis and venous blood gas analysis. Because of venous blood sampling is safer than arterial blood gas analysis, and beside not so different among them for detecting pH, pCO2, HCO3, except pO2 measuring. This research was done in emergency room, and for explaining no different between arterial blood gas analysis and peripheral blood gas analysis result in acid-base unbalance state patient. Especially in kidney functions decreased state. : The study was done from March, 2010 to January, 2011. The object was 89 peoples who came to emergency room for treating internal medicine problem. (Women 53, average age: 66.7±12.1 Then compare between arterial blood gas analysis and peripheral blood gas analysis. Result: The mean arterial minus venous difference for pH, pCO2, and bicarbonate was −0.0170, 2.6528, and 0.6124. Bland-Altman plot was done for predicting agreement of two groups, and the scale was pH −2.95 to 4.17, pCO2 −4.45 to 9.76, bicarbonate −2.95 to 4.16, in 95% relative. Conclusion: The peripheral blood gas pH, pCO2, bicarbonate level is almost same as arterial blood gas analysis results. And enough to measuring acid-base unbalance state, in absent of arterial blood testing.

Central venous pressure and mean circulatory filling pressure in the dogfish Squalus acanthias: adrenergic control and role of the pericardium.

Science.gov (United States)

Sandblom, Erik; Axelsson, Michael; Farrell, Anthony P

2006-11-01

Subambient central venous pressure (Pven) and modulation of venous return through cardiac suction (vis a fronte) characterizes the venous circulation in sharks. Venous capacitance was estimated in the dogfish Squalus acanthias by measuring the mean circulatory filling pressure (MCFP) during transient occlusion of cardiac outflow. We tested the hypothesis that venous return and cardiac preload can be altered additionally through adrenergic changes of venous capacitance. The experiments involved the surgical opening of the pericardium to place a perivascular occluder around the conus arteriosus. Another control group was identically instrumented, but lacked the occluder, and was subjected to the same pharmacological protocol to evaluate how pericardioectomy affected cardiovascular status. Routine Pven was negative (-0.08+/-0.02 kPa) in control fish but positive (0.09+/-0.01 kPa) in the pericardioectomized group. Injections of 5 microg/kg body mass (Mb) of epinephrine and phenylephrine (100 microg/kg Mb) increased Pven and MCFP, whereas isoproterenol (1 microg/kg Mb) decreased both variables. Thus, constriction and relaxation of the venous vasculature were mediated through the respective stimulation of alpha- and beta-adrenergic receptors. Alpha-adrenergic blockade with prazosin (1 mg/kg Mb) attenuated the responses to phenylephrine and decreased resting Pven in pericardioectomized animals. Our results provide convincing evidence for adrenergic control of the venous vasculature in elasmobranchs, although the pericardium is clearly an important component in the modulation of venous function. Thus active changes in venous capacitance have previously been underestimated as an important means of modulating venous return and cardiac performance in this group.

What Is High Blood Pressure?

Science.gov (United States)

... Disease Venous Thromboembolism Aortic Aneurysm More What is High Blood Pressure? Updated:Feb 27,2018 First, let’s define high ... resources . This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

Quantitative assessment of cerebral blood flow by 123I-IMP SPECT

International Nuclear Information System (INIS)

Moriwaki, Hiroshi; Matsumoto, Masayasu; Hashikawa, Kazuo

1993-01-01

To establish a noninvasive, quantitative method for measuring regional cerebral blood flow (rCBF) by N-isopropyl-p-[ 123 I]iodoamphetamine ( 123 I-IMP) SPECT, we attempted to employ continuous venous sampling instead of arterial sampling. Forty two patients with cerebrovascular disease were classified into two groups, with (group II: n=35) and without (group I: n=7) hand warming. In group II, either hand was warmed, wrapping in a hot blanket (group IIA) or immersed in a 44degC water bath (group IIB). Immediately after intravenous bolus injection of 222 MBq IMP, arterial and venous blood samples were collected continuously for 5 min from the radial artery and the cubital vein, respectively. By octanol extraction, IMP was divided into the unmetabolized and metabolized fractions. The ratio of 123 I-IMP of venous blood to arterial blood (pass ratio, referred to as %PR) was calculated in the whole blood, unmetabolized, and metabolized fractions. Using these parameters, we assessed the possibility to estimate the amount of unmetabolized IMP fraction of arterial blood, usually used as an input function, from venous samples. In group I, %PR demonstrated a considerable variation between individuals (whole IMP, 47.5±24.6%; unmetabolized IMP, 46.0±24.5%; metabolized IMP, 51.8±27.4%). In group II, especially in group IIB, both increase of %PR value and the decrease in variation (whole, 77.9±5.6%; unmetabolized, 75.7±5.7%; metabolized, 86.7±8.7%) were observed, permitting the further calculation based on the assumption that %PR value was constant in each IMP fraction. The coefficient of variation of the difference between estimated arterial IMP radioactivity from venous samples and actual arterial IMP was 9.0% and 7.5%. The use of venous sampling coupled with a hand warming technique allowed the estimation of the arterial unmetabolized IMP radioactivity from venous samples with a reliability of 90% or more. (author)

The effect of a cryotherapy gel wrap on the microcirculation of skin affected by Chronic Venous Disorders

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Mueller, Martina; Zapka, Jane G.; King, Dana E.

2011-01-01

Aim This randomized clinical trial was conducted 2008 – 2009 to investigate a cryotherapy (cooling) gel wrap applied to lower leg skin affected by chronic venous disorders to determine whether therapeutic cooling improves skin microcirculation. Impaired skin microcirculation contributes to venous leg ulcer development, thus new prevention therapies should address the microcirculation to prevent venous leg ulcers. Data Sources Sixty participants (n = 30 per group) were randomized to receive one of two daily 30-minute interventions for four weeks. The treatment group applied the cryotherapy gel wrap around the affected lower leg skin, or compression and elevated the legs on a special pillow each evening at bedtime. The standard care group wore compression and elevated the legs only. Laboratory pre- and post-measures included microcirculation measures of skin temperature with a thermistor, blood flow with a laser Doppler flowmeter, and venous refill time with a photoplethysmograph. Review methods Data were analysed using descriptive statistics, paired t-tests or Wilcoxon signed ranks tests, logistic regression analyses, and mixed model analyses. Results Fifty-seven participants (treatment = 28; standard care = 29) completed the study. The mean age was 62 years, 70% female, 50% African American. In the final adjusted model, there was a statistically significant decrease in blood flow between the two groups (−6.2[−11.8; −0.6], P = 0.03). No statistically significant differences were noted in temperature or venous refill time. Conclusion Study findings suggest that cryotherapy improves blood flow by slowing movement within the microcirculation and thus might potentially provide a therapeutic benefit to prevent leg ulcers. PMID:21592186

[Correlation between resting heart rate and blood glucose level in elderly patients with coronary heart disease and diabetes mellitus].

Science.gov (United States)

Liang, Dong-Liang; Li, Xiao-Ying; Wang, Lin; Xu, Hao; Tuo, Xi-Ping; Jian, Zai-Jin; Wang, Xiao-Na; Yun, Ji-Li; Zhang, Xu; Wang, Si-Yue

2016-05-01

To explore the correlation between resting heart rate (RHR) and blood glucose level in elderly patients with coronary heart disease (CHD) complicated by diabetes mellitus. Between April and July, 2011, a total of 1336 outpatients over 60 years of age recruited from 165 hospitals were asked to complete a questionnaire and received blood glucose and RHR examination. According to baseline RHR, the patients were divided into 3 groups with HRH blood glucose control rate. HbA1c levels in the total, male and female patients differed significantly among the 3 groups (F=15.436, 15.436, and 24.270, respectively, PBlood glucose control rate in the total, male and female patients also differed significantly among the 3 groups (χ(2)=13.471, 6.752, and 6.522, respectively, Pblood glucose control failure of 1.99 (95% CI: 1.23-2.37, Pblood glucose level, and an increased RHR is associated with an increased risk of poor blood glucose control. Rigorous RHR control in such high-risk patients may prove beneficial for both blood glucose control and secondary prevention of CHD.

Acute changes in forearm venous volume and tone using radionuclide plethysmography

International Nuclear Information System (INIS)

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

1988-01-01

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

Gestational related changes in the deep venous system of the lower limb on light reflection rheography in pregnancy and the puerperium

Energy Technology Data Exchange (ETDEWEB)

Calderwood, C.J. [St John' s Hospital, Livingston and Simpson Centre for Reproductive Health, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom)], E-mail: catherine.calderwood@luht.scot.nhs.uk; Jamieson, R. [Princess Royal Maternity Unit, Glasgow Royal Infirmary, Glasgow (United Kingdom); Greer, I.A. [Hull York Medical School, University of York, York (United Kingdom)

2007-12-15

Objective: To assess whether light reflection rheography testing is affected by the changes that occur in the deep venous system of the lower limb in pregnancy and the puerperium. Methods: Twenty five women with a singleton pregnancy were recruited to undergo duplex Doppler ultrasound examinations of the common femoral vein to measure the vessel diameter and the blood flow velocity. Light reflection rheography testing was subsequently performed and the rate of venous emptying in the lower limb calculated. Serial measurements using both techniques were made at 15, 28, 36 weeks, and term gestation and at 2 days and 6 weeks postpartum. Results: Duplex Doppler ultrasound confirmed that there is progressive dilatation of the deep venous system in pregnancy, which reaches a maximum at term and reverses after delivery. There is an accompanying reduction in blood flow velocity, which reaches a nadir at term and increases after delivery. The rate of venous emptying as measured by light reflection rheography decreases with increasing gestation, but did not fall to a level consistent with venous occlusion by a deep venous thrombosis. Conclusions: Light reflection rheography has been shown to provide reliable results in pregnancy and the puerperium. Therefore, it is a potential tool for screening for deep venous thrombosis in this population.

Gestational related changes in the deep venous system of the lower limb on light reflection rheography in pregnancy and the puerperium

International Nuclear Information System (INIS)

Calderwood, C.J.; Jamieson, R.; Greer, I.A.

2007-01-01

Objective: To assess whether light reflection rheography testing is affected by the changes that occur in the deep venous system of the lower limb in pregnancy and the puerperium. Methods: Twenty five women with a singleton pregnancy were recruited to undergo duplex Doppler ultrasound examinations of the common femoral vein to measure the vessel diameter and the blood flow velocity. Light reflection rheography testing was subsequently performed and the rate of venous emptying in the lower limb calculated. Serial measurements using both techniques were made at 15, 28, 36 weeks, and term gestation and at 2 days and 6 weeks postpartum. Results: Duplex Doppler ultrasound confirmed that there is progressive dilatation of the deep venous system in pregnancy, which reaches a maximum at term and reverses after delivery. There is an accompanying reduction in blood flow velocity, which reaches a nadir at term and increases after delivery. The rate of venous emptying as measured by light reflection rheography decreases with increasing gestation, but did not fall to a level consistent with venous occlusion by a deep venous thrombosis. Conclusions: Light reflection rheography has been shown to provide reliable results in pregnancy and the puerperium. Therefore, it is a potential tool for screening for deep venous thrombosis in this population

Age and regional cerebral blood flow at rest and during cognitive activity

International Nuclear Information System (INIS)

Gur, R.C.; Gur, R.E.; Obrist, W.D.; Skolnick, B.E.; Reivich, M.

1987-01-01

The relationship between age and regional cerebral blood flow (rCBF) activation for cognitive tasks was investigated with the xenon (Xe 133) inhalation technique. The sample consisted of 55 healthy subjects, ranging in age from 18 to 72 years, who were studied during rest and during the performance of verbal analogy and spatial orientation tasks. The dependent measures were indexes of gray-matter rCBF and average rCBF (gray and white matter) as well as the percentage of gray-matter tissue. Advanced age was associated with reduced flow, particularly pronounced in anterior regions. However, the extent and pattern of rCBF changes during cognition was unaffected by age. For the percentage of gray matter, there was a specific reduction in anterior regions of the left hemisphere. The findings suggest the utility of this research paradigm for investigating neural underpinnings of the effects of dementia on cognitive functioning, relative to the effects of normal aging

Brain-Derived Neurotrophic Factor Val66Met Polymorphism Affects the Relationship Between an Anxiety-Related Personality Trait and Resting Regional Cerebral Blood Flow.

Science.gov (United States)

Wei, Shau-Ming; Eisenberg, Daniel P; Nabel, Katherine G; Kohn, Philip D; Kippenhan, J Shane; Dickinson, Dwight; Kolachana, Bhaskar; Berman, Karen F

2017-03-01

Brain-derived neurotrophic factor (BDNF) is an important modulator of constitutive stress responses mediated by limbic frontotemporal circuits, and its gene contains a functional polymorphism (Val66Met) that may influence trait stress sensitivity. Reports of an association of this polymorphism with anxiety-related personality traits have been controversial and without clear neurophysiological support. We, therefore, determined the relationship between resting regional cerebral blood flow (rCBF) and a well-validated measure of anxiety-related personality, the TPQ Harm Avoidance (HA) scale, as a function of BDNF Val66Met genotype. Sixty-four healthy participants of European ancestry underwent resting H215O positron emission tomography scans. For each genotype group separately, we first determined the relationship between participants' HA scores and their resting rCBF values in each voxel across the entire brain, and then directly compared these HA-rCBF relationships between Val66Met genotype groups. HA-rCBF relationships differed between Val homozygotes and Met carriers in several regions relevant to stress regulation: subgenual cingulate, orbital frontal cortex, and the hippocampal/parahippocampal region. In each of these areas, the relationship was positive in Val homozygotes and negative in Met carriers. These data demonstrate a coupling between trait anxiety and basal resting blood flow in frontolimbic neurocircuitry that may be determined in part by genetically mediated BDNF signaling. Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Acute vascular effects of waterpipe smoking: Importance of physical activity and fitness status.

Science.gov (United States)

Alomari, Mahmoud A; Khabour, Omar F; Alzoubi, Karem H; Shqair, Dana M; Stoner, Lee

2015-06-01

While new forms of tobacco, including waterpipe (WP) smoking, continue to gain popularity, limited literature has examined the vascular health consequences. The purpose of the current study was to examine: (i) the acute WP-induced changes in vascular function; (ii) whether acute changes in vascular function are modified by lifestyle behaviors (habitual physical activity, physical fitness). Fifty three (22.7 y, 36% F, 23.4 kg/m(2)) otherwise healthy WP smokers were recruited. Strain-gauge plethysmography was used to measure forearm blood flow, vascular resistance, venous capacitance, and venous outflow at rest and following occlusion. Habitual physical activity was determined using the Arabic version of short-form international physical activity questionnaire, while physical fitness was assessed using the 6 min walk test and handgrip strength. Partial correlations were used to examine the relationships between post-smoking vascular function and lifestyle behaviors, controlling for pre-smoking vascular measures. (i) WP had a small effect on forearm post-occlusion blood flow (d = -0.19), a moderate effect on venous outflow (d = 0.30), and a moderate effect on post-occlusion vascular resistance (d = 0.32). (ii) Total habitual physical activity strongly correlated with resting blood flow (r = 0.50) and moderately with vascular resistance (r = -0.40). Handgrip strength moderately correlated with venous capacitance (r = 0.30) and post-occlusion blood flow (r = 0.30), while 6 min walked distance moderately correlated with resting venous capacitance (r = 0.30). Waterpipe smoking is associated with immediate changes in vascular function, which are exacerbated in individuals with low habitual physical activity and physical fitness levels in young otherwise healthy individuals. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

DEFF Research Database (Denmark)

Clemmesen, Jens-Otto; Giraldi, Annamaria; Ott, Peter

2008-01-01

AIM: To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with cirrhosis. Phosphodiesterase type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liv...... type-5 inhibitor sildenafil, the present study could not demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG....

Resting venous plasma adrenalin in 70-year-old men correlated positively to survival in a population study: the significance of the physical working capacity

DEFF Research Database (Denmark)

Christensen, Niels Juel; Schultz-Larsen, K

1994-01-01

in a comprehensive medical examination. INTERVENTIONS. Plasma NA and A were measured in blood samples collected after the subjects had rested in the supine position for 15 min. The subjects have now been followed for 7 years. MAIN OUTCOME MEASURES. Seven years later, 115 men and 63 women had died. RESULTS. Cox...... of physical working capacity was included in the Cox regression analysis, both plasma NA and plasma A became insignificant, whereas a strong positive correlation appeared between physical working capacity and survival (P

Spatial heterogeneity of the relation between resting-state connectivity and blood flow: an important consideration for pharmacological studies.

Science.gov (United States)

Khalili-Mahani, Najmeh; van Osch, Matthias J; de Rooij, Mark; Beckmann, Christian F; van Buchem, Mark A; Dahan, Albert; van Gerven, Johannes M; Rombouts, Serge A R B

2014-03-01

Resting state fMRI (RSfMRI) and arterial spin labeling (ASL) provide the field of pharmacological Neuroimaging tool for investigating states of brain activity in terms of functional connectivity or cerebral blood flow (CBF). Functional connectivity reflects the degree of synchrony or correlation of spontaneous fluctuations--mostly in the blood oxygen level dependent (BOLD) signal--across brain networks; but CBF reflects mean delivery of arterial blood to the brain tissue over time. The BOLD and CBF signals are linked to common neurovascular and hemodynamic mechanisms that necessitate increased oxygen transportation to the site of neuronal activation; however, the scale and the sources of variation in static CBF and spatiotemporal BOLD correlations are likely different. We tested this hypothesis by examining the relation between CBF and resting-state-network consistency (RSNC)--representing average intranetwork connectivity, determined from dual regression analysis with eight standard networks of interest (NOIs)--in a crossover placebo-controlled study of morphine and alcohol. Overall, we observed spatially heterogeneous relations between RSNC and CBF, and between the experimental factors (drug-by-time, time, drug and physiological rates) and each of these metrics. The drug-by-time effects on CBF were significant in all networks, but significant RSNC changes were limited to the sensorimotor, the executive/salience and the working memory networks. The post-hoc voxel-wise statistics revealed similar dissociations, perhaps suggesting differential sensitivity of RSNC and CBF to neuronal and vascular endpoints of drug actions. The spatial heterogeneity of RSNC/CBF relations encourages further investigation into the role of neuroreceptor distribution and cerebrovascular anatomy in predicting spontaneous fluctuations under drugs. Copyright © 2012 Wiley Periodicals, Inc.

Petechiae: reproducible pattern of distribution and increased appearance after bed rest.

Science.gov (United States)

Ganse, Bergita; Limper, Ulrich; Bühlmeier, Judith; Rittweger, Jörn

2013-08-01

Exposure to acceleration can cause petechial hemorrhages, called G measles. Petechiae usually start to develop between 5 and 9 G with a high interindividual variance. Centrifuge training delays the onset to higher G levels. One might expect onset at lower G levels after bed rest; however, there is no evidence in the literature. A case of petechiae formation after bed rest is presented here. Orthostatic tolerance was tested using a tilt table and lower body negative pressure before and after bed rest in both campaigns of a 2 x 21-d bed rest study with 6 degrees head-down tilt. A 42-yr-old male Caucasian without any history of thrombosis, venous disease, hemorrhage, or petechiae, and with a negative thrombophilia screening, took part in the bed rest study as 1 out of 10 subjects. He was the only one to develop petechiae during the orthostatic tests after, but not before, bed rest in both campaigns. Petechiae were distributed throughout the lower legs and most pronounced at the shin in a stocking-like fashion, surprisingly reoccurring in an identical pattern of distribution. Petechiae appeared slowly over minutes during hyperemia. This case indicates that prolonged bed rest decreases the threshold for petechiae formation. A reproducible distribution pattern suggests that factors predisposing to petechiae formation keep their local distribution over time (possibly due to local vessel structures). Mechanisms of adaptation and interindividual variance are unclear. Findings are of clinical relevance as such cases might occur after prolonged bed rest in patients without need of expensive testing.

Clinical applications of resting state functional connectivity

Directory of Open Access Journals (Sweden)

Michael D Fox

2010-06-01

Full Text Available During resting conditions the brain remains functionally and metabolically active. One manifestation of this activity that has become an important research tool is spontaneous fluctuations in the blood oxygen level dependent (BOLD signal of fMRI. The identification of correlation patterns in these spontaneous fluctuations has been termed resting state functional connectivity (fcMRI and has the potential to greatly increase the translation of fMRI into clinical care. In this article we review the advantages of the resting state signal for clinical applications including detailed discussion of signal to noise considerations. We include guidelines for performing resting state research on clinical populations, outline the different areas for clinical application, and identify important barriers to be addressed to facilitate the translation of resting state fcMRI into the clinical realm.

Dried blood spot measurement: application in tacrolimus monitoring using limited sampling strategy and abbreviated AUC estimation.

Science.gov (United States)

Cheung, Chi Yuen; van der Heijden, Jaques; Hoogtanders, Karin; Christiaans, Maarten; Liu, Yan Lun; Chan, Yiu Han; Choi, Koon Shing; van de Plas, Afke; Shek, Chi Chung; Chau, Ka Foon; Li, Chun Sang; van Hooff, Johannes; Stolk, Leo

2008-02-01

Dried blood spot (DBS) sampling and high-performance liquid chromatography tandem-mass spectrometry have been developed in monitoring tacrolimus levels. Our center favors the use of limited sampling strategy and abbreviated formula to estimate the area under concentration-time curve (AUC(0-12)). However, it is inconvenient for patients because they have to wait in the center for blood sampling. We investigated the application of DBS method in tacrolimus level monitoring using limited sampling strategy and abbreviated AUC estimation approach. Duplicate venous samples were obtained at each time point (C(0), C(2), and C(4)). To determine the stability of blood samples, one venous sample was sent to our laboratory immediately. The other duplicate venous samples, together with simultaneous fingerprick blood samples, were sent to the University of Maastricht in the Netherlands. Thirty six patients were recruited and 108 sets of blood samples were collected. There was a highly significant relationship between AUC(0-12), estimated from venous blood samples, and fingerprick blood samples (r(2) = 0.96, P AUC(0-12) strategy as drug monitoring.

Glucose kinetics at rest and during exercise in gluconeogenesis-inhibited rats

International Nuclear Information System (INIS)

Turcotte, L.P.

1988-01-01

To evaluate the role played by gluconeogenesis in blood glucose homeostasis, untrained and trained rats were injected with mercaptopicolinic acid (MPA), a known inhibitor of the gluconeogenic enzyme, phosphoenolpyruvate carboxykinase. Glucose turnover, recycling and oxidation rates were assessed by primed-continuous infusion of [U- 14 C]- and [6- 3 H] glucose at rest and during submaximal exercise at 13.4 m/min on level grade. When compared to the untrained sham-injected animals, the untrained MPA-treated animals had 22% lower and 44% higher resting blood glucose and lactate concentrations, respectively. Resting glucose turnover, calculated from [6- 3 H]glucose, was 32% lower in the MPA-treated animals than in the sham-injected animals. During exercise, turnover increased in the sham-injected animals but remained unchanged in the MPA-treated animals. MPA-treated animals had no glucose recycling at rest or during exercise. Exercise further decreased blood glucose concentration and increased blood lactate concentration in the MPA-treated animals, but MPA treatment did not change the exercise-induced increases in glucose oxidation rate, % total VCO 2 arising from glucose oxidation and metabolic clearance rate of glucose

Rapid computation of single PET scan rest-stress myocardial blood flow parametric images by table look up.

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Guehl, Nicolas J; Normandin, Marc D; Wooten, Dustin W; Rozen, Guy; Ruskin, Jeremy N; Shoup, Timothy M; Woo, Jonghye; Ptaszek, Leon M; Fakhri, Georges El; Alpert, Nathaniel M

2017-09-01

We have recently reported a method for measuring rest-stress myocardial blood flow (MBF) using a single, relatively short, PET scan session. The method requires two IV tracer injections, one to initiate rest imaging and one at peak stress. We previously validated absolute flow quantitation in ml/min/cc for standard bull's eye, segmental analysis. In this work, we extend the method for fast computation of rest-stress MBF parametric images. We provide an analytic solution to the single-scan rest-stress flow model which is then solved using a two-dimensional table lookup method (LM). Simulations were performed to compare the accuracy and precision of the lookup method with the original nonlinear method (NLM). Then the method was applied to 16 single scan rest/stress measurements made in 12 pigs: seven studied after infarction of the left anterior descending artery (LAD) territory, and nine imaged in the native state. Parametric maps of rest and stress MBF as well as maps of left (f LV ) and right (f RV ) ventricular spill-over fractions were generated. Regions of interest (ROIs) for 17 myocardial segments were defined in bull's eye fashion on the parametric maps. The mean of each ROI was then compared to the rest (K 1r ) and stress (K 1s ) MBF estimates obtained from fitting the 17 regional TACs with the NLM. In simulation, the LM performed as well as the NLM in terms of precision and accuracy. The simulation did not show that bias was introduced by the use of a predefined two-dimensional lookup table. In experimental data, parametric maps demonstrated good statistical quality and the LM was computationally much more efficient than the original NLM. Very good agreement was obtained between the mean MBF calculated on the parametric maps for each of the 17 ROIs and the regional MBF values estimated by the NLM (K 1map LM  = 1.019 × K 1 ROI NLM  + 0.019, R 2  = 0.986; mean difference = 0.034 ± 0.036 mL/min/cc). We developed a table lookup method for fast

Prevention of catheter-related blood stream infection.

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Byrnes, Matthew C; Coopersmith, Craig M

2007-08-01

Catheter-related blood stream infections are a morbid complication of central venous catheters. This review will highlight a comprehensive approach demonstrated to prevent catheter-related blood stream infections. Elements of prevention important to inserting a central venous catheter include proper hand hygiene, use of full barrier precautions, appropriate skin preparation with 2% chlorhexidine, and using the subclavian vein as the preferred anatomic site. Rigorous attention needs to be given to dressing care, and there should be daily assessment of the need for central venous catheters, with prompt removal as soon as is practicable. Healthcare workers should be educated routinely on methods to prevent catheter-related blood stream infections. If rates remain higher than benchmark levels despite proper bedside practice, antiseptic or antibiotic-impregnated catheters can also prevent infections effectively. A recent program utilizing these practices in 103 ICUs in Michigan resulted in a 66% decrease in infection rates. There is increasing recognition that a comprehensive strategy to prevent catheter-related blood stream infections can prevent most infections, if not all. This suggests that thousands of infections can potentially be averted if the simple practices outlined herein are followed.

Effect of exercise therapy on lower extremity deep venous thrombosis after total knee arthoplasty

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Zhong-Wu Huang

2016-11-01

Full Text Available Objective: To explore the effect of exercise therapy in preventing the lower extremity deep venous thrombosis (DVT after total knee arthoplasty (TKA. Methods: A total of 153 patients with osteoarthritis who were admitted in our hospital for TKA were included in the study and randomized into the observation group and the control group. The patients in the observation group were given continuous passive motion (CPM in combined with exercise therapy, while the patients in the control group were only given CPM. After 2-week treatment, the related coagulation indicators and femoral venous blood flow in the two groups were detected and compared. The occurrence rate of DVT in the two groups was calculated. Results: PT and APTT from 2 weeks to 2 months after operation in the two groups were shortened first and extended later when compared with before operation, while FIB and D-D contents were elevated first and reduced later, and the coagulation indicator levels 2 months after treatment in the two groups were significantly different from those before operation. The femoral venous blood flow peak and average velocity 1 week after operation in the two groups were significantly elevated when compared with before operation. The femoral venous blood flow peak and average velocity 1 week after operation in the observation group were significantly higher than those in the control group. The occurrence rate of DVT in the observation group was significantly lower than that in the control group. Conclusions: CPM in combined with exercise therapy for patients after TKA can effectively prevent the formation of DVT, with a significant effect.

Venous Ulcers

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Caprini, J.A.; Partsch, H.; Simman, R.

2013-01-01

Venous leg ulcers are the most frequent form of wounds seen in patients. This article presents an overview on some practical aspects concerning diagnosis, differential diagnosis and treatment. Duplex ultrasound investigations are essential to ascertain the diagnosis of the underlying venous pathology and to treat venous refluxes. Differential diagnosis includes mainly other vascular lesions (arterial, microcirculatory causes), hematologic and metabolic diseases, trauma, infection, malignancies. Patients with superficial venous incompetence may benefit from endovenous or surgical reflux abolition diagnosed by Duplex ultrasound. The most important basic component of the management is compression therapy, for which we prefer materials with low elasticity applied with high initial pressure (short-stretch bandages and Velcro-strap devices). Local treatment should be simple, absorbing and not sticky dressings keeping adequate moisture balance after debridement of necrotic tissue and biofilms are preferred. After the ulcer is healed compression therapy should be continued in order to prevent recurrence. PMID:26236636

Nonarterialized Venous Replantation of Part of Amputated Thumb—A Case Report and Review of the Literature

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Kalimuthu, Ramasamy

2006-01-01

Since the first successful replantation of a human thumb reported by Komatsu and Tamai in 1968, thousands of severed digits and body parts have been successfully salvaged. Restoration of anatomic form and function are the goals of replantation after traumatic tissue amputation. Regardless of anatomic location, methods include microsurgical replantation and nonmicrosurgical replantation, such as composite graft techniques. Numerous techniques to maximize tissue survival after revascularization have been described, including “pocket procedures” to salvage composite grafts, interposition vein grafts, and medicinal leeches to name a few. Artery-to-venous anastomoses have been performed with successful “arterialization” of the distal venous system in fingertip replantation. Although there is documented survival of free venous cutaneous flaps, to our knowledge this is the first report of a replanted composite body part (bone, tendon, soft tissues, and skin) utilizing exclusively multiple, microvascular, nonarterialized venous–venous anastomoses. We present a patient with an isolated band saw fillet amputation to the back of the thumb at the metacarpal–phalangeal joint region, resulting in a composite graft composed of bone, tendon, soft tissue, and skin. The hand wound provided no viable regional arterial inflow source, but there were multiple good caliber superficial veins present. The amputated tissues were replanted and revascularized by using only venous blood flow. The replanted part survival was 100% with excellent function of the digit. We conclude that a hand composite body part involving bone, tendon, soft tissues, and skin can survive replantation with a strict venous blood supply if sufficient good caliber, microvascular, venous–venous anastomoses are performed, granted that arterial inflow options are not available. This is an isolated case, yet introduces a new way of thinking regarding tissue replantation. PMID:18780032

Assessment of liver circulation by quantitative scintiangiography: Evaluation of the relative contribution of the hepatic arterial and portal venous blood flows to liver perfusion

International Nuclear Information System (INIS)

Molino, G.; Squadrone, E.; Baccegal, M.; Magnani, C.

1989-01-01

Quantitative hepatic scintiangiography was previously used for evaluating the relative contribution of hepatic arterial and portal venous blood flows to the hepatic circulation. The present study compares 3 different procedures (automatic and manual integration, and slope fitting methods) for analyzing the hepatic time activity curves obtained after bolus i.v. injection of 370 MBq 99m Tc-diethylentriaminopentacetic acid. Twenty five subjects were studied: Five controls, ten cirrhotics, and ten portal hypertensive patients previously submitted to side to side portacaval anastomosis. The correspondence between results given by the different methods was satisfactory only in shunted patients, and the reproducibility of computed parameters was quite poor for all procedures. Accordingly, none of the methods can be considered as supporting reliable quantitative pathophysiological evaluations. However, the hepatic arterial/portal venous flow ratio was found to be increased in liver cirrhosis and in shunted patients and therefore, in spite of the limitations underlined before and of the absence of data on the reproducibility of consecutive injections, hepatic scintiangiography may be of some clinical utility. (orig.)

High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

Science.gov (United States)

Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

2011-03-01

Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

DEFF Research Database (Denmark)

Clemmesen, J.O.; Giraldi, A.; Ott, P.

2008-01-01

AIM: To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with cirrhosis. Phosphodiesterase type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liv...... type-5 inhibitor sildenafil, the present study could not demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG Udgivelsesdato: 2008/10/28...

Slaughter value, meat quality, creatine kinase activity and cortisol levels in the blood serum of growing-finishing pigs slaughtered immediately after transport and after a rest period.

Science.gov (United States)

Smiecińska, K; Denaburski, J; Sobotka, W

2011-01-01

The experimental materials comprised 44 hybrid [female (Polish Large White x Polish Landrace) x male Duroc] growing-finishing pigs. The animals were randomly divided into two groups: 24 pigs were slaughtered immediately after transport and 20 pigs were slaughtered after a 24-hour rest period in the lairage. The meat content of pork carcasses, carcass dressing percentage, the proximate chemical composition, physicochemical and sensory properties of meat and shear force values were determined. Serum creatine kinase activity and cortisol levels were determined in blood samples collected before transport and during carcass bleeding. Pigs slaughtered immediately after transport, compared with those slaughtered after a 24-hour rest period, were characterized by a higher meat content of the carcass and a higher carcass dressing percentage. Pre-slaughter handling had no effect on pork quality. The incidence of normal-quality meat, partially PSE (pale, soft, exudative) meat and PSE meat was similar in both groups. Chemical analysis showed that the content of dry matter, total protein, fat and minerals in meat was comparable in both groups. As regards the functional properties of the pork, samples from the carcasses of pigs that had rested before slaughter had a higher contribution of the red color component. Meat from pigs slaughtered immediately after transport had more desirable sensory properties. Pre-slaughter resting had a significant effect on those analyzed physiological parameters which were found to be good indicators of pre-slaughter stress. Serum creatine kinase activity and cortisol levels were higher in blood samples collected after transport (during carcass bleeding) than in samples collected before transport, pointing to a strong stress response of animals to pre-slaughter treatment. The decrease in serum cortisol levels in blood samples collected during bleeding from the carcasses of pigs slaughtered after a 24-hour rest period, compared with samples

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.

Low-protein vegetarian diet does not have a short-term effect on blood acid–base status but raises oxygen consumption during submaximal cycling

Directory of Open Access Journals (Sweden)

Hietavala Enni-Maria

2012-11-01

Full Text Available Abstract Background Acid–base balance refers to the equilibrium between acids and bases in the human body. Nutrition may affect acid–base balance and further physical performance. With the help of PRAL (potential renal acid load, a low-protein vegetarian diet (LPVD was designed to enhance the production of bases in body. The aim of this study was to investigate if LPVD has an effect on blood acid–base status and performance during submaximal and maximal aerobic cycling. Methods Nine healthy, recreationally active men (age 23.5 ± 3.4 yr participated in the study and were randomly divided into two groups in a cross-over study design. Group 1 followed LPVD for 4 days and group 2 ate normally (ND before performing a cycle ergometer test. The test included three 10-min stages at 40, 60 and 80% of VO2max. The fourth stage was performed at 100% of VO2max until exhaustion. After 10–16 days, the groups started a second 4-day diet, and at the end performed the similar ergometer test. Venous blood samples were collected at the beginning and at the end of both diet periods and after every stage cycled. Results Diet caused no significant difference in venous blood pH, strong ion difference (SID, total concentration of weak acids (Atot, partial pressure of CO2 (pCO2 or HCO3- at rest or during cycling between LPVD and ND. In the LPVD group, at rest SID significantly increased over the diet period (38.6 ± 1.8 vs. 39.8 ± 0.9, p=0.009. Diet had no significant effect on exercise time to exhaustion, but VO2 was significantly higher at 40, 60 and 80% of VO2max after LPVD compared to ND (2.03 ± 0.25 vs. 1.82 ± 0.21 l/min, p=0.035; 2.86 ± 0.36 vs. 2.52 ± 0.33 l/min, p Conclusion There was no difference in venous blood acid–base status between a 4-day LPVD and ND. VO2 was increased during submaximal cycling after LPVD suggesting that the exercise economy was poorer. This had no further effect on maximal aerobic performance. More studies are needed to

The use of medicinal leeches in fingertip replantation without venous anastomosis - case report of a 4-year-old patient.

Science.gov (United States)

Streit, L; Dvořák, Z; Novák, O; Stiborová, S; Veselý, J

2014-01-01

Replantation of amputated fingertip is a technical challenge to the microsurgeons. The success rate depends directly on the availability and the size of preserved vessels and on the degree of their damage. In distal digital amputations, veins are usually not easily recovered or even absent, and thus high number of replantation procedures fails because of the venous congestion. The use of medicinal leeches is a treatment option for venous congestion of replanted fingers. A case report of a 4-year-old patient after fingertip replantation without venous anastomosis when temporary venous drainage was provided by an application of medicinal leeches is reported together with literature review. We observed an unusually short duration of venous congestion (48 hours) and there was no need of blood transfusion.

Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

DEFF Research Database (Denmark)

Clemmesen, Jens-Otto; Giraldi, Annamaria; Ott, Peter

2008-01-01

AIM: To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with cirrhosis. Phosphodiesterase type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liver...

Detecting deep venous thrombosis with limited flip angle gradient refocused MR imaging

International Nuclear Information System (INIS)

Spritzer, C.E.; Sussman, S.K.; Herfkens, R.J.; Blinder, R.A.; Saeed, M.; Vogler, J.A.; Baker, M.E.

1987-01-01

This study was undertaken to determine if limited flip angle gradient refocused MR pulse sequences (GRASS) could be used to accurately diagnose deep venous thrombosis (DVT). Sixteen patients (17 extremities) with possible DVT were prospectively evaluated with MR imaging and venography. Typical imaging parameters included a 16-msec echo time, 33-msec repetition time, 30 0 flip angle, and section thickness of 2 nex. MR imaging correctly disclosed the presence (nine cases) or absence (eight cases) of DVT. In one study, GRASS images overestimated the extent of clot due to slow venous blood flow. Subsequently the flip angle was varied to distinguish between venous thrombus and slow flow. When this technique was used, no false-positive studies occurred in the remaining patients. MR gradient refocused imaging appears to be an accurate aid for the diagnosis of DVT

The Ovine Cerebral Venous System: Comparative Anatomy, Visualization, and Implications for Translational Research

Science.gov (United States)

Nitzsche, Björn; Lobsien, Donald; Seeger, Johannes; Schneider, Holm; Boltze, Johannes

2014-01-01

Cerebrovascular diseases are significant causes of death and disability in humans. Improvements in diagnostic and therapeutic approaches strongly rely on adequate gyrencephalic, large animal models being demanded for translational research. Ovine stroke models may represent a promising approach but are currently limited by insufficient knowledge regarding the venous system of the cerebral angioarchitecture. The present study was intended to provide a comprehensive anatomical analysis of the intracranial venous system in sheep as a reliable basis for the interpretation of experimental results in such ovine models. We used corrosion casts as well as contrast-enhanced magnetic resonance venography to scrutinize blood drainage from the brain. This combined approach yielded detailed and, to some extent, novel findings. In particular, we provide evidence for chordae Willisii and lateral venous lacunae, and report on connections between the dorsal and ventral sinuses in this species. For the first time, we also describe venous confluences in the deep cerebral venous system and an ‘anterior condylar confluent’ as seen in humans. This report provides a detailed reference for the interpretation of venous diagnostic imaging findings in sheep, including an assessment of structure detectability by in vivo (imaging) versus ex vivo (corrosion cast) visualization methods. Moreover, it features a comprehensive interspecies-comparison of the venous cerebral angioarchitecture in man, rodents, canines and sheep as a relevant large animal model species, and describes possible implications for translational cerebrovascular research. PMID:24736654

Prevention of venous pain and phlebitis caused by epirubicin hydrochloride.

Science.gov (United States)

Sugimoto, Masakazu; Matsui, Masateru; Harada, Masanori; Yamauchi, Yumiko; Moriyama, Nao; Andou, Kanae; Yamamoto, Makoto; Yamaoka, Hisayo; Ono, Chiemi; Ishikawa, Mami; Kamo, Nobuyuki; Ikeda, Tadashi; Yamaoka, Keiko

2009-06-01

Many patients complain of venous pain or develop phlebitis following treatment with epirubicin hydrochloride(EPI). To ensure effective and safe treatment with this drug, it is essential to deal with the adverse events associated with it appropriately. At our hospital, EPI was previously administered by drip infusion(diluted with 50mL of physiological saline)over 15 minutes after pretreatment(EPI main route). With this method of treatment, venous pain and phlebitis developed in 14 of 15 cases. In 3 of these 14 cases, the regimen was modified. Following this experience, EPI administration was switched to drip infusion from the fully-opened side tube used for pretreatment(EPI sub-route). Switching to this route resulted in a sharp decrease in the incidence of venous pain and phlebitis, to only 1 of 15 cases. Stimulation of vascular tunica intima by EPI has been considered a factor principally responsible for the venous pain and phlebitis seen after EPI therapy. To prevent these adverse reactions, it is necessary to modify the method of administration so that strong or long-term exposure of blood vessels to EPI can be reduced. The results of this study suggest that the EPI sub-route we devised is useful in achieving this goal.

Fingertip replantation without venous anastomosis.

Science.gov (United States)

Chen, Yi-Chieh; Chan, Fuan Chiang; Hsu, Chung-Chen; Lin, Yu-Te; Chen, Chien-Tzung; Lin, Chih-Hung

2013-03-01

Replantation of amputated fingertips is a technical challenge, as many salvage procedures fail because no suitable vein in the fingertip is available for anastomosis. In this study, we examined our experience in fingertip replantation in cases without venous anastomosis with our established fingertip replantation treatment protocol. Between August 2002 and August 2010, a retrospective study examined all patients who had undergone fingertip replantation at Chang-Gung Memorial Hospital. All the patients (n = 24) suffered from complete digital amputations at or distal to the interphalangeal joint of the thumb, or distal to distal interphalangeal joint of the fingers. A total of 30 fingertips that were salvaged by microsurgical anastomosis of the digital arteries but not of digital veins were included in this study. On satisfactory arterial anastomosis, a 2-mm incision was made over the fingertip with a number 11 Scalpel blade, and 0.1 to 0.2 mL heparin (5000 IU/mL) was injected subcutaneously around the incision immediately and once per day thereafter to ensure continuous blood drainage from the replanted fingertip. None of the replanted nail plate was removed, and no medical leeches were used. The perfusion of the replanted digits and patient's hemoglobin level were closely monitored. The wound bleeding was maintained until physiologic venous outflow was restored. Of 30 fingertips, 27 (90%) replanted fingertips survived. The average length needed for maintaining external bleeding by chemical leech was 6.8 days (range, 5-10 days). Twelve patients (including a 2-year-old child) received blood transfusions. The average amount of blood transfusion in the 23 adults was 4.0 units (range, 0-16 units) for each patient or 3.29 units (range, 0-14 units) for each digit. A 2-year-old child received 100 mL blood transfusion or 50 mL for each digit. This study showed that a protocol that promotes controlled bleeding from the fingertip is essential to achieve consistent high

Medical management of venous ulcers.

Science.gov (United States)

Pascarella, Luigi; Shortell, Cynthia K

2015-03-01

Venous disease is the most common cause of chronic leg ulceration and represents an advanced clinical manifestation of venous insufficiency. Due to their frequency and chronicity, venous ulcers have a high socioeconomic impact, with treatment costs accounting for 1% of the health care budget in Western countries. The evaluation of patients with venous ulcers should include a thorough medical history for prior deep venous thrombosis, assessment for an hypercoagulable state, and a physical examination. Use of the CEAP (clinical, etiology, anatomy, pathophysiology) Classification System and the revised Venous Clinical Severity Scoring System is strongly recommended to characterize disease severity and assess response to treatment. This venous condition requires lifestyle modification, with affected individuals performing daily intervals of leg elevation to control edema; use of elastic compression garments; and moderate physical activity, such as walking wearing below-knee elastic stockings. Meticulous skin care, treatment of dermatitis, and prompt treatment of cellulitis are important aspects of medical management. The pharmacology of chronic venous insufficiency and venous ulcers include essentially two medications: pentoxifylline and phlebotropic agents. The micronized purified flavonoid fraction is an effective adjunct to compression therapy in patients with large, chronic ulceration. Copyright © 2015 Elsevier Inc. All rights reserved.

Diagnosis of venous disorders

International Nuclear Information System (INIS)

Minar, E.

1993-01-01

Limited accuracy in the clinic diagnosis of deep vein thrombosis (VT) makes such diagnostic tests such as duplex sonography or venography necessary. Exact information on the age and extent of the thrombus are necessary for the clinician to optimize the therapeutric management. The correct diagnosis of calf vein thrombosis and of recurrent VT in patients with postphlebitis changes also has implications for treatment. After exclusion of thrombosis, the radiologist should evaluate the leg for other possible causes of symptoms besides VT. Investigation of the venous sytem also has a role in the diagnosis in patients with suspected pulmonary embolism. In patients with chronic venous insuffficiency the deep venous system should assessed for patency and venous valve function. The superficial veins should be differentiated in segments with sufficient or insufficient venous valves, and it is also necessary to look for insufficiency of the perforrating veins. In patients with superficial phlebitis there is risk of propagation into the deep venous system. (orig.) [de

Brain venous pathologies: MRI findings

International Nuclear Information System (INIS)

Salvatico, Rosana; Gonzalez, Alejandro; Yanez, Paulina; Romero, Carlos; Trejo, Mariano; Lambre, Hector

2006-01-01

Purpose: To describe MRI findings of the different brain venous pathologies. Material and Methods: Between January 2002 and March 2004, 18 patients were studied 10 males and 8 females between 6 and 63 years old; with different brain venous pathologies. In all cases brain MRI were performed including morphological sequences with and without gadolinium injection and angiographic venous sequences. Results: 10 venous occlusions were found, 6 venous angiomas, and 2 presented varices secondary to arteriovenous dural fistula. Conclusion: Brain venous pathologies can appear in many different clinical contexts, with different prognosis and treatment. In all the cases brain MRI was the best imaging study to disclose typical morphologic abnormalities. (author) [es

Use of Dried Capillary Blood Sampling for Islet Autoantibody Screening in Relatives: A Feasibility Study.

Science.gov (United States)

Bingley, Polly J; Rafkin, Lisa E; Matheson, Della; Steck, Andrea K; Yu, Liping; Henderson, Courtney; Beam, Craig A; Boulware, David C

2015-12-01

Islet autoantibody testing provides the basis for assessment of risk of progression to type 1 diabetes. We set out to determine the feasibility and acceptability of dried capillary blood spot-based screening to identify islet autoantibody-positive relatives potentially eligible for inclusion in prevention trials. Dried blood spot (DBS) and venous samples were collected from 229 relatives participating in the TrialNet Pathway to Prevention Study. Both samples were tested for glutamic acid decarboxylase, islet antigen 2, and zinc transporter 8 autoantibodies, and venous samples were additionally tested for insulin autoantibodies and islet cell antibodies. We defined multiple autoantibody positive as two or more autoantibodies in venous serum and DBS screen positive if one or more autoantibodies were detected. Participant questionnaires compared the sample collection methods. Of 44 relatives who were multiple autoantibody positive in venous samples, 42 (95.5%) were DBS screen positive, and DBS accurately detected 145 of 147 autoantibody-negative relatives (98.6%). Capillary blood sampling was perceived as more painful than venous blood draw, but 60% of participants would prefer initial screening using home fingerstick with clinic visits only required if autoantibodies were found. Capillary blood sampling could facilitate screening for type 1 diabetes prevention studies.

Cerebral venous angiomas

International Nuclear Information System (INIS)

Agnoli, A.L.; Hildebrandt, G.

1985-01-01

Clinical symptoms and radiological signs in 15 patients with cerebral venous malformations are presented and the diagnostic problems discussed. The circulation time in combination with cerebral malformations and angiomas of the scalp are described. CT findings in cases of venous malformations of the brain stem are evaluated. Spot-like enhancement, as well as sharply demarcated round shaped enhancement are characteristic for venous angiomas. Cavernous angiomas usually present as homogenous or inhomogenous round shaped enhanced areas. (Author)

The Effects of a 10-Week Water Aerobic Exercise on the Resting Blood Pressure in Patients with Essential Hypertension

OpenAIRE

Farahani, Ali Vasheghani; Mansournia, Mohammad-Ali; Asheri, Hossein; Fotouhi, Akbar; Yunesian, Masud; Jamali, Mohsen; Ziaee, Vahid

2010-01-01

Purpose To investigate the effects of a 10-week water aerobic exercise on the resting blood pressure in patients with stage 1 or 2 hypertension referring to Tehran University Clinics. Methods Forty men with stage 1 or 2 essential hypertension were assigned to two groups of intervention [n = 12; aged 48.33±10.74 years (mean±SD)] and control [n = 28; aged 46.96±11.58 years (mean±SD)]. Subjects in the intervention group participated ...

The venous manifestations of pulse wave encephalopathy: windkessel dysfunction in normal aging and senile dementia

Energy Technology Data Exchange (ETDEWEB)

Bateman, Grant A. [Locked Bag 1, Newcastle Region Mail Center, Department of Medical Imaging, John Hunter Hospital, Newcastle (Australia); Levi, Christopher R.; Wang, Yang; Lovett, Elizabeth C. [Hunter Medical Research Institute, Clinical Neurosciences Program, Newcastle (Australia); Schofield, Peter [James Fletcher Hospital, Neuropsychiatry Unit, Newcastle (Australia)

2008-06-15

Cerebral arterial, venous and cerebrospinal fluid (CSF) pulsations are closely coupled and this produces pulsation dampening or the windkessel effect. Normal pressure hydrocephalus is a manifestation of the breakdown of this windkessel effect with altered CSF and venous pulsations being noted. The aim of this study was to show that dysfunction of the windkessel mechanism is also a component of normal aging and senile dementia. The study group comprised 24 patients classified as either early senile dementia of Alzheimer's type (SDAT) or vascular dementia (VaD). The patients with dementia were compared with 12 age-matched non-cognitively impaired subjects, and 12 normal young individuals were compared with the normal aging group. MRI flow quantification was used to measure the nonpulsatile and pulsatile components of blood flow as well as the pulsation at the tentorial incisura. With normal aging blood flow decreased but arterial pulsations increased in volume by 49% (P = 0.003). The CSF vented via the tentorial incisura does not change significantly with age and therefore increased venous pulsation is necessary. In patients with VaD the arterial pulse volume was higher by 24% and the straight sinus pulsation was higher by 57% than in normal aging subjects (P = 0.05 and P = 0.03, respectively). In patients with SDAT the total venous pulsation volumes were similar to those in normal aging subjects but there was less basal sinus pulsation. Normal aging, SDAT and VaD are associated with alterations in venous pulsation due to a breakdown of the windkessel effect. (orig.)

Bone blood flow and metabolism in humans

DEFF Research Database (Denmark)

Heinonen, Ilkka; Kemppainen, Jukka; Kaskinoro, Kimmo

2012-01-01

Human bone blood flow and metabolism during physical exercise remains poorly characterised. In the present study we measured femoral bone blood flow and glucose uptake in young healthy subjects by positron emission tomography in three separate protocols. In six women, blood flow was measured...... in femoral bone at rest and during one leg intermittent isometric exercise with increasing exercise intensities. In nine men, blood flow in femur was determined at rest and during dynamic one leg exercise, and two other physiological perturbations: moderate systemic hypoxia (14 O(2) ) at rest and during...... exercise, and during intra-femoral infusion of high-dose adenosine. Bone glucose uptake was measured at rest and during dynamic one leg exercise in five men. The results indicate that isometric exercise increased femoral bone blood flow from rest (1.8 ± 0.6 ml/100g/min) to low intensity exercise (4.1 ± 1...

Relationship of 133Xe cerebral blood flow to middle cerebral arterial flow velocity in men at rest

Science.gov (United States)

Clark, J. M.; Skolnick, B. E.; Gelfand, R.; Farber, R. E.; Stierheim, M.; Stevens, W. C.; Beck, G. Jr; Lambertsen, C. J.

1996-01-01

Cerebral blood flow (CBF) was measured by 133Xe clearance simultaneously with the velocity of blood flow through the left middle cerebral artery (MCA) over a wide range of arterial PCO2 in eight normal men. Average arterial PCO2, which was varied by giving 4% and 6% CO2 in O2 and by controlled hyperventilation on O2, ranged from 25.3 to 49.9 mm Hg. Corresponding average values of global CBF15 were 27.2 and 65.0 ml 100 g min-1, respectively, whereas MCA blood-flow velocity ranged from 42.8 to 94.2 cm/s. The relationship of CBF to MCA blood-flow velocity over the imposed range of arterial PCO2 was described analytically by a parabola with the equation: CBF = 22.8 - 0.17 x velocity + 0.006 x velocity2 The observed data indicate that MCA blood-flow velocity is a useful index of CBF response to change in arterial PCO2 during O2 breathing at rest. With respect to baseline values measured while breathing 100% O2 spontaneously, percent changes in velocity were significantly smaller than corresponding percent changes in CBF at increased levels of arterial PCO2 and larger than CBF changes at the lower arterial PCO2. These observed relative changes are consistent with MCA vasodilation at the site of measurement during exposure to progressive hypercapnia and also during extreme hyperventilation hypocapnia.

Effective flow performances and dialysis doses delivered with permanent catheters: a 24-month comparative study of permanent catheters versus arterio-venous vascular accesses.

Science.gov (United States)

Canaud, Bernard; Leray-Moragues, Hélène; Kerkeni, Nadia; Bosc, Jean-Yves; Martin, Katja

2002-07-01

Permanent venous catheters have emerged as a long-term vascular access option for renal replacement therapy in end-stage renal disease patients. The design and venous location of catheter devices bear intrinsic flow limitations that may negatively affect the adequacy of dialysis and the patient outcome. There is limited data comparing the long-term dialysis adequacy delivered with permanent catheters vs arterio-venous vascular accesses (AVA). To explore this problem, we conducted a prospective 24-month trial comparing the flow performances and dialysis dose (Kt/Vdp) deliveries of both access options in a group of 42 haemodialysis patients during two study phases. During the first 12 months the patients completed a treatment period by means of permanent dual silicone catheters (DualKT). Then they were transferred to an AVA (40 native arterio-venous fistulas and two PTFE grafts) and monitored for an additional 12-month period. Assessments of flow adequacy and dialysis quantification were performed monthly. Dialysis adequacy was achieved in all cases. No patient had to be transferred prematurely to the AVA because of catheter failure. Three catheters had to be replaced due to bacteraemia in three patients. The mean effective blood flow rates achieved were 316+/-3.5 ml/min and 340+/-3.3 ml/min with DualKT and AVA, respectively, for a pre-set machine blood flow of 348+/-2.2 ml/min. Recirculation rates evaluated with the 'slow blood flow' method were 8.6+/-0.6 and 12.1+/-0.8% for DualKT and AVA using mean values of the solute markers urea and creatinine. Due to the possibility of a comparison veno-venous vs arterio-venous blood circulation, a corrected arterio-venous access recirculation could be derived from the difference between the two, which was around 3%. The blood flow resistance of the DualKT was slightly higher than with AVA as indicated by venous pressure differences. Kt/Vdp delivered was 1.37+/-0.02 and 1.45+/-0.02 with DualKT and AVA access respectively. The

Evaluation by means of ECG-gated cardiac blood pool scintigraphy of global and regional left ventricular function at rest and during exercise in patients with coronary artery disease

International Nuclear Information System (INIS)

Sauer, E.; Sebening, H.; Lutilsky, L.; Dressler, H.; Hoer, G.; Pabst, H.W.; Bloemer, H.; Technische Univ. Muenchen

1978-01-01

ECG-gated cardiac blood pool scintigraphy permits a non-invasive determination of the end-diastolic and end-systolic ventricular volumens and of the ejection fraction as well as a qualitative description of regional ventricular wall motion at rest and during exercise. In 6 healthy persons a significant increase of the ejection fraction from 66 +- 7% at rest to 78 +- 3% during exercise (p [de

Monitoring arterio-venous differences of glucose and lactate in the anesthetized rat with or without brain damage with ultrafiltration and biosensor technology

NARCIS (Netherlands)

Leegsma-Vogt, G; Venema, K; Postema, F; Korf, J

2001-01-01

Continuous monitoring of arterio-venous glucose and lactate differences may serve as a diagnostic tool to assess normal brain function and brain pathology. We describe a method and some results obtained with arterio-venous measurements of glucose and lactate in the blood of the

A first look into the influence of triathlon wetsuit on resting blood pressure and heart rate variability

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A Prado

2016-12-01

Full Text Available The purpose of this study was to investigate the effects of wearing a wetsuit on resting cardiovascular measures (blood pressure (BP, heart rate variability (HRV. The influence of position (upright, prone and wetsuit size were also explored. Participants (n=12 males, 33.3±12.1 years had BP and HRV measured during six resting conditions: standing or prone while not wearing a wetsuit (NWS, wearing the smallest (SWS, or largest (LWS wetsuit (based upon manufacturer guidelines. Heart rate was recorded continuously over 5-mins; BP was measured three times per condition. HRV was represented by the ratio of low (LF and high (HF frequency (LF/HF ratio; mean arterial pressure (MAP was calculated. Each dependent variable was analyzed using a 2 (position x 3 (wetsuit repeated measures ANOVA (α=0.05. Neither HRV parameter was influenced by position x wetsuit condition interaction (p>0.05 and MAP was not influenced by position (p=0.717. MAP and LF/HF ratio were both influenced by wetsuit condition (p<0.05 with higher during SWS than NWS (p=0.026 while LF/HF ratio was lower during SWS compared to NWS (p=0.032. LF/HF ratio was influenced by position being greater during standing vs. prone (p=0.001. It was concluded that during resting while on land (i.e., not submerged in water, wearing a small, tight-fitting wetsuit subtlety altered cardiovascular parameters for healthy, normotensive subjects.

Models of the venous system

DEFF Research Database (Denmark)

Mehlsen, J

2000-01-01

Cardiac output is largely controlled by venous return, the driving force of which is the energy remaining at the postcapillary venous site. This force is influenced by forces acting close to the right atrium, and internally or externally upon the veins along their course. Analogue models of the v......Cardiac output is largely controlled by venous return, the driving force of which is the energy remaining at the postcapillary venous site. This force is influenced by forces acting close to the right atrium, and internally or externally upon the veins along their course. Analogue models...... of the venous system require at least three elements: a resistor, a capacitor and an inductor, with the latter being of more importance in the venous than in the arterial system. Non-linearities must be considered in pressure/flow relations in the small venules, during venous collapse, or low flow conditions...

The resting sites and blood-meal sources of Anopheles minimus in Taiwan.

Science.gov (United States)

Chang, Mei-Chun; Teng, Hwa-Jen; Chen, Chen-Fu; Chen, Yung-Chen; Jeng, Chian-Ren

2008-06-09

The WHO declared Taiwan free from malaria in 1965, but in 2003 the reporting of two introduced cases in a rural area suggested a possible local transmission of this disease. Therefore, understanding the resting sites and the blood sources of Anopheles minimus is crucial in order to provide information for implementing vector control strategies. During a two-year survey, mosquitoes were collected in houses and their surrounding areas and at the bank of larval habitats by backpack aspirators in 17 villages in rural areas of southern and eastern Taiwan for 1 hr. On the same day, blacklight traps were hung downward overnight. Blood-fed mosquito samples were analysed by PCR. Of the 195 total households surveyed by backpack aspirators, no Anopheles adults were collected inside the houses, while a single Anopheles minimus and a single Anopheles maculatus were collected outside of the houses. On the same day, 23 An. minimus, two An. maculatus, two Anopheles ludlowae, two Anopheles sinensis, and one Anopheles tessellatus were collected along the bank of larval habitats. In blacklight traps hung outside of the houses in the villages, 69 An. minimus, 62 An. ludlowae, 31 An. sinensis, and 19 An. maculatus were collected. In larval habitats, 98 An. ludlowae, 64 An. minimus, 49 An. sinensis, and 14 An. maculatus were collected. Of a total of 10 blood-fed samples, An. minimus fed on four animals including bovine (60%), dogs (20%), pig (10%), and non-chicken avian (10%). Anopheles minimus, an opportunist feeder in Taiwan, was not collected inside the houses, but was found outside of the houses in villages and surrounding larval habitats. Therefore, an outdoor transmission of malaria is likely to occur and, thus, the bed nets, which are favoured for controlling the late biting of An. minimus, should be a very efficient and effective method for those local residents who sleep outdoors. Additionally, space spray of insecticides for Anopheles at night, as well as residual spray inside

Venous, Arterialized-Venous, or Capillary Glucose Reference Measurements for the Accuracy Assessment of a Continuous Glucose Monitoring System.

Science.gov (United States)

Kropff, Jort; van Steen, Sigrid C; deGraaff, Peter; Chan, Man W; van Amstel, Rombout B E; DeVries, J Hans

2017-11-01

Different reference methods are used for the accuracy assessment of continuous glucose monitoring (CGM) systems. The effect of using venous, arterialized-venous, or capillary reference measurements on CGM accuracy is unclear. We evaluated 21 individuals with type 1 diabetes using a capillary calibrated CGM system. Venous or arterialized-venous reference glucose samples were taken every 15 min at two separate visits and assessed per YSI 2300 STAT Plus. Arterialization was achieved by heated-hand technique. Capillary samples were collected hourly during the venous reference visit. The investigation sequence (venous or arterialized-venous) was randomized. Effectiveness of arterialization was measured by comparing free venous oxygen pressure (PO2) of both visit days. Primary endpoint was the median absolute relative difference (ARD). Median ARD using arterialized-venous reference samples was not different from venous samples (point estimated difference 0.52%, P = 0.181). When comparing the three reference methods, median ARD was also not different over the full glycemic range (venous 9.0% [n = 681], arterialized-venous 8.3% [n = 684], and capillary 8.1% [n = 205], P = 0.216), nor over the separate glucose ranges. Arterialization was successful (PO2 venous 5.4 kPa vs. arterialized-venous 8.9 kPa, P reference measurements did not significantly impact CGM accuracy. Venous reference seems preferable due to its ease of operation.

Monstrous venous haemangioma tumor of the retroperitonial space - Diagnosis and diagnostic problems

International Nuclear Information System (INIS)

Leinung, S.; Wuerl, P.; Frey, A.; Schoenfelder, M.; Lotz, I.; Lochhaas, L.

2000-01-01

The preoperative diagnosis and its inherent problems are illustrated using a coincidentally diagnosed monstrous haemangioma tumor of the retroperitonial space in a twenty year old patient. With respect to our patient, X-ray, computer tomography and angiography all failed as diagnostic tools. Only the use of Doppler sonographic flow signals suggested the presence of a haemangioma. The morphology, prognosis and clinical significance of blood vessel tumors are multifaceted. The most important differential diagnoses to the venous haemangioma are the cavernous and the cappilliary haemangioma. The venous haemangioma distinguishes itself through the presence of blood vessel walls. Haemangiomas are common benign tumors. In the presence of highly developed muscular components, there exists a transition to angiomyomas and to leiomyomas. Venal haemangiomas are extremely rare in the demonstrated localisation of the retroperitoneal space. Here they can grow to monstrous preportions whilst remaining undetected. Thus the patient is under the potential danger of bleeding to death through trivial injuries. The therapy of choice reamins total surgical excision. (orig.) [de

Plasma volume changes during hypoglycaemia: the effect of arterial blood sampling

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...... hypoglycaemia. The magnitude of the changes in arterial and venous blood were not significantly different. These results indicate that the above changes in blood volume and composition are whole-body phenomena: furthermore, the major part of the changes are likely to occur in tissues other than upper extremity...

Computed tomographic characteristics of collateral venous pathways in dogs with caudal vena cava obstruction.

Science.gov (United States)

Specchi, Swan; d'Anjou, Marc-André; Carmel, Eric Norman; Bertolini, Giovanna

2014-01-01

Collateral venous pathways develop in dogs with obstruction or increased blood flow resistance at any level of the caudal vena cava in order to maintain venous drainage to the right atrium. The purpose of this retrospective study was to describe the sites, causes of obstruction, and configurations of venous collateral pathways for a group of dogs with caudal vena cava obstruction. Computed tomography databases from two veterinary hospitals were searched for dogs with a diagnosis of caudal vena cava obstruction and multidetector row computed tomographic angiographic (CTA) scans that included the entire caudal vena cava. Images for each included dog were retrieved and collateral venous pathways were characterized using image postprocessing and a classification system previously reported for humans. A total of nine dogs met inclusion criteria and four major collateral venous pathways were identified: deep (n = 2), portal (n = 2), intermediate (n = 7), and superficial (n = 5). More than one collateral venous pathway was present in 5 dogs. An alternative pathway consisting of renal subcapsular collateral veins, arising mainly from the caudal pole of both kidneys, was found in three dogs. In conclusion, findings indicated that collateral venous pathway patterns similar to those described in humans are also present in dogs with caudal vena cava obstruction. These collateral pathways need to be distinguished from other vascular anomalies in dogs. Postprocessing of multidetector-row CTA images allowed delineation of the course of these complicated venous pathways and may be a helpful adjunct for treatment planning in future cases. © 2014 American College of Veterinary Radiology.

Central venous catheter-related bloodstream infections in cancer patients

International Nuclear Information System (INIS)

Butt, T.; Afzal, R.K.; Ahmad, R.N.; Hussain, I.; Anwar, M.

2004-01-01

Objective: To determine the frequency of central venous catheter-related bloodstream infections (CR-BSI) in cancer patients and the antimicrobial susceptibility pattern of the isolates. Subjects and Methods: Cancer patients requiring short or long-term central venous catheterization at the time of admission or thereafter were included. Catheter tips on removal were cultured quantitatively; specimens of blood and pus were cultured qualitatively. Isolates were identified and antimicrobial susceptibility testing was performed by standard techniques. Results: Eighty-nine patients were included in the study. The frequency of CR-BSI was 17%. Out of the 19 organisms isolated, 10 (53%) were Gram-positive cocci, 8 (42%) were Gram-negative rods and 1 (5%) was a fungus. Coagulase negative staphylococci (27%) were the predominant pathogens. Among the staphylococci, 46% of the isolates were methicillin-resistant. All Gram-positive isolates were susceptive to glycopeptides. Gram-negative rods were resistant to most of the commonly used antimicrobial groups. Conclusion: Central venous catheter is an important source of bloodstream infections in cancer patients. Most of the infections are caused by Gram-positive cocci. Rigorous infection control measures and continuous surveillance is required to curb the frequency of these infections. (author)

Characterizing Resting-State Brain Function Using Arterial Spin Labeling

Science.gov (United States)

Jann, Kay; Wang, Danny J.J.

2015-01-01

Abstract Arterial spin labeling (ASL) is an increasingly established magnetic resonance imaging (MRI) technique that is finding broader applications in studying the healthy and diseased brain. This review addresses the use of ASL to assess brain function in the resting state. Following a brief technical description, we discuss the use of ASL in the following main categories: (1) resting-state functional connectivity (FC) measurement: the use of ASL-based cerebral blood flow (CBF) measurements as an alternative to the blood oxygen level-dependent (BOLD) technique to assess resting-state FC; (2) the link between network CBF and FC measurements: the use of network CBF as a surrogate of the metabolic activity within corresponding networks; and (3) the study of resting-state dynamic CBF-BOLD coupling and cerebral metabolism: the use of dynamic CBF information obtained using ASL to assess dynamic CBF-BOLD coupling and oxidative metabolism in the resting state. In addition, we summarize some future challenges and interesting research directions for ASL, including slice-accelerated (multiband) imaging as well as the effects of motion and other physiological confounds on perfusion-based FC measurement. In summary, this work reviews the state-of-the-art of ASL and establishes it as an increasingly viable MRI technique with high translational value in studying resting-state brain function. PMID:26106930

Morphologic changes of cerebral veins in hypertensive rats: venous collagenosis is associated with hypertension.

Science.gov (United States)

Zhou, Min; Mao, Lijuan; Wang, Ying; Wang, Qian; Yang, Zhiyun; Li, Shurong; Li, Ling

2015-03-01

The aims of this study were to determine whether arterial hypertension could affect the venous system of brain and to find out the consequent pathologic changes of cerebral veins. Thirty male Sprague-Dawley rats were divided into 2 groups: a sham-clipped group and a stroke-prone renovascular hypertensive rat group. A 2-kidney 2-clip rat model was used to induce renovascular hypertension in the hypertensive group. Systolic blood pressure was measured by tail cuff once each week. Susceptibility-weighted imaging (SWI) was performed at 12, 16, and 20 weeks after surgery. All the rats were sacrificed after the SWI examination at 20 weeks after surgery. The brains were extracted and embedded in paraffin for histologic examination. Masson trichrome staining was performed to identify venous collagenosis. The sham group demonstrated less prominence of cerebral veins compared with hypertensive groups (P veins on SWI as a sign of venous hypertension and the thickened cerebral venous walls (venous collagenosis), which may play a role in cerebral ischemia and/or infarction, are both consequences of long-term hypertension in hypertensive rats. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Thermographic venous blood flow characterization with external cooling stimulation

Science.gov (United States)

Saxena, Ashish; Ng, E. Y. K.; Raman, Vignesh

2018-05-01

Experimental characterization of blood flow in a human forearm is done with the application of continuous external cooling based active thermography method. Qualitative and quantitative detection of the blood vessel in a thermal image is done, along with the evaluation of blood vessel diameter, blood flow direction, and velocity in the target blood vessel. Subtraction based image manipulation is performed to enhance the feature contrast of the thermal image acquired after the removal of external cooling. To demonstrate the effect of occlusion diseases (obstruction), an external cuff based occlusion is applied after the removal of cooling and its effect on the skin rewarming is studied. Using external cooling, a transit time method based blood flow velocity estimation is done. From the results obtained, it is evident that an external cooling based active thermography method can be used to develop a diagnosis tool for superficial blood vessel diseases.

Magnetic resonance angiography with blood-pool contrast agents: future applications

International Nuclear Information System (INIS)

Fink, C.; Goyen, M.; Lotz, J.

2007-01-01

Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

Magnetic resonance angiography with blood-pool contrast agents: future applications

Energy Technology Data Exchange (ETDEWEB)

Fink, C. [Univ. Hospitals, Grosshadern, Munich (Germany); Goyen, M. [Univ. Medical Center, Hamburg-Eppendorf, Hamburg (Germany); Lotz, J. [Hannover Medical School, Hannover (Germany)

2007-03-15

Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

Early results from an angiosome-directed open surgical technique for venous arterialization in patients with critical lower limb ischemia

Directory of Open Access Journals (Sweden)

Kim Houlind

2013-12-01

Full Text Available Background: Patients with critical lower limb ischemia without patent pedal arteries cannot be treated by the conventional arterial reconstruction. Venous arterialization has been suggested to improve limb salvage in this subgroup of patients but has not gained wide acceptance. We report our early experience after implementing deep and superficial venous arterialization of the lower limb. Materials and methods: Ten patients with critical ischemia and without crural or pedal arteries available for conventional bypass surgery or angioplasty were treated with distal venous arterialization. Inflow was from the most distal unobstructed segment. Run-off was the dorsal pedal venous arch (n=5, the dorsal pedal venous arch and a concomitant vein of the posterior tibial artery (n=3, or the dorsal pedal venous arch and a concomitant vein of the common plantar artery (n=2 depending on the location of the ischemic lesion. Venous valves were destroyed using antegrade valvulotomes, guide wires, knob needles, or retrograde valvulotomes via an extra incision. Results: Seven of the operated limbs were amputated after 23 (1–256 days (median [range]. The main reasons for amputation were lack of healing of either the original wound, of incisional wounds on the foot, or persisting pain at rest. In three cases, the bypass was open at the time of amputation. Two patients experienced complete wound healing after 231 and 342 days, respectively. By the end of follow-up, the last patient was ambulating with slow wound healing but without pain 309 days after surgery. Conclusion: Venous arterialization may be used as a treatment of otherwise unsalveable limbs. The success rate is, however, limited. Technical optimization of the technique is warranted.

Prophylaxis of Venous Thrombosis.

Science.gov (United States)

Goldhaber, Samuel Z.

2001-06-01

Mechanical measures such as graduated compression stockings and intermittent compression boots are available for venous thrombosis prophylaxis, but compliance may be limited. Plantar venous pneumatic compression devices have attained widespread acceptance by both patients and nurses because of their comfort and compact size, but their track record for efficacy is poor. Inferior vena cava filters prevent pulmonary embolism, but do not halt the thrombotic process or prevent venous thrombosis. Pharmacologic prophylaxis traditionally has relied upon minidose unfractionated heparin; however, re-examination is warranted in the face of increasingly ill and complex patients. My opinion is that small, fixed doses of once-daily low molecular weight heparin will eventually replace minidose unfractionated heparin as the standard pharmacologic prophylaxis regimen for most surgical and medical patients. Prolongation of prophylaxis after hospital discharge should receive increased emphasis. Most patients being transferred to a skilled nursing facility should receive venous thromboembolism prophylaxis. Similarly, most patients undergoing total hip or knee replacement should receive prolonged preventive regimens, with at least 1 month of anticoagulation. Despite advances, certain aspects of venous thrombosis prophylaxis remain problematic. First, a surprisingly high number of hospitalized patients develop venous thrombosis because of failed (rather than omitted) prophylaxis. Second, many patients in intensive care have a combination of peripheral vascular disease and active bleeding (usually gastrointestinal) that precludes mechanical or pharmacologic prophylaxis. Third, neurosurgical patients undergoing craniotomy for brain tumors suffer a high rate of venous thrombosis and major pulmonary embolism despite the routine use of combined mechanical and pharmacologic prophylaxis. My opinion is that these three areas, in addition to the hospital culture of prophylaxis, should receive

Correcting for Blood Arrival Time in Global Mean Regression Enhances Functional Connectivity Analysis of Resting State fMRI-BOLD Signals.

Science.gov (United States)

Erdoğan, Sinem B; Tong, Yunjie; Hocke, Lia M; Lindsey, Kimberly P; deB Frederick, Blaise

2016-01-01

Resting state functional connectivity analysis is a widely used method for mapping intrinsic functional organization of the brain. Global signal regression (GSR) is commonly employed for removing systemic global variance from resting state BOLD-fMRI data; however, recent studies have demonstrated that GSR may introduce spurious negative correlations within and between functional networks, calling into question the meaning of anticorrelations reported between some networks. In the present study, we propose that global signal from resting state fMRI is composed primarily of systemic low frequency oscillations (sLFOs) that propagate with cerebral blood circulation throughout the brain. We introduce a novel systemic noise removal strategy for resting state fMRI data, "dynamic global signal regression" (dGSR), which applies a voxel-specific optimal time delay to the global signal prior to regression from voxel-wise time series. We test our hypothesis on two functional systems that are suggested to be intrinsically organized into anticorrelated networks: the default mode network (DMN) and task positive network (TPN). We evaluate the efficacy of dGSR and compare its performance with the conventional "static" global regression (sGSR) method in terms of (i) explaining systemic variance in the data and (ii) enhancing specificity and sensitivity of functional connectivity measures. dGSR increases the amount of BOLD signal variance being modeled and removed relative to sGSR while reducing spurious negative correlations introduced in reference regions by sGSR, and attenuating inflated positive connectivity measures. We conclude that incorporating time delay information for sLFOs into global noise removal strategies is of crucial importance for optimal noise removal from resting state functional connectivity maps.

Cerebral blood flow measured by arterial spin labeling MRI at resting state in normal aging and Alzheimer's disease.

Science.gov (United States)

Zhang, Nan; Gordon, Marc L; Goldberg, Terry E

2017-01-01

Arterial spin labeling (ASL) magnetic resonance imaging uses arterial blood water as an endogenous tracer to measure cerebral blood flow (CBF). In this review, based on ASL studies in the resting state, we discuss state-of-the-art technical and data processing improvements in ASL, and ASL CBF changes in normal aging, mild cognitive impairment (MCI), Alzheimer's disease (AD), and other types of dementia. We propose that vascular and AD risk factors should be considered when evaluating CBF changes in aging, and that other validated biomarkers should be used as inclusion criteria or covariates when evaluating CBF changes in MCI and AD. With improvements in hardware and experimental design, ASL is proving to be an increasingly promising tool for exploring pathogenetic mechanisms, early detection, monitoring disease progression and pharmacological response, and differential diagnosis of AD. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

A novel approach to the management of critically ill neonatal Ebstein's anomaly: Veno-venous extracorporeal membrane oxygenation to promote right ventricular recovery.

Science.gov (United States)

Bauser-Heaton, Holly; Nguyen, Charles; Tacy, Theresa; Axelrod, David

2015-01-01

This is the first report of the use of veno-venous extracorporeal membrane oxygenation in a neonate with severe Ebstein's anomaly. The report suggests the use of veno-venous extracorporeal membrane oxygenation in the immediate neonatal period may be a useful therapy in severe Ebstein's anomaly. By providing adequate oxygenation independent of the patient's native pulmonary blood flow, veno-venous extracorporeal membrane oxygenation allows the pulmonary vascular resistance to decrease and may promote right ventricular recovery.

Blood sample collection and patient identification demand improvement: a questionnaire study of preanalytical practices in hospital wards and laboratories.

Science.gov (United States)

Wallin, Olof; Söderberg, Johan; Van Guelpen, Bethany; Stenlund, Hans; Grankvist, Kjell; Brulin, Christine

2010-09-01

Scand J Caring Sci; 2010; 24; 581-591 
 Blood sample collection and patient identification demand improvement: a questionnaire study of preanalytical practices in hospital wards and laboratories   Most errors in venous blood testing result from human mistakes occurring before the sample reach the laboratory.   To survey venous blood sampling (VBS) practices in hospital wards and to compare practices with hospital laboratories.   Staff in two hospitals (all wards) and two hospital laboratories (314 respondents, response rate 94%), completed a questionnaire addressing issues relevant to the collection of venous blood samples for clinical chemistry testing.   The findings suggest that instructions for patient identification and the collection of venous blood samples were not always followed. For example, 79% of the respondents reported the undesirable practice (UDP) of not always using wristbands for patient identification. Similarly, 87% of the respondents noted the UDP of removing venous stasis after the sampling is finished. Compared with the ward staff, a significantly higher proportion of the laboratory staff reported desirable practices regarding the collection of venous blood samples. Neither education nor the existence of established sampling routines was clearly associated with VBS practices among the ward staff.   The results of this study, the first of its kind, suggest that a clinically important risk of error is associated with VBS in the surveyed wards. Most important is the risk of misidentification of patients. Quality improvement of blood sample collection is clearly needed, particularly in hospital wards. © 2009 The Authors. Journal compilation © 2009 Nordic College of Caring Science.

Genomewide linkage scan of resting blood pressure: HERITAGE Family Study. Health, Risk Factors, Exercise Training, and Genetics.

Science.gov (United States)

Rice, Treva; Rankinen, Tuomo; Chagnon, Yvon C; Province, Michael A; Pérusse, Louis; Leon, Arthur S; Skinner, James S; Wilmore, Jack H; Bouchard, Claude; Rao, Dabeeru C

2002-06-01

The purpose of this study was to search for genomic regions influencing resting systolic (SBP) and diastolic (DBP) blood pressure (BP) in sedentary families (baseline), and for resting BP responses (changes) resulting from a 20-week exercise training intervention (post-training-baseline) in the Health, Risk Factors, Exercise Training, and Genetics (HERITAGE) Family Study. A genome-wide scan was conducted on 317 black individuals from 114 families and 519 white individuals from 99 families using a multipoint variance-components linkage model and a panel of 509 markers. Promising results were primarily, but not exclusively, found in the black families. Linkage evidence (PHERITAGE data, in conjunction with results from previous genomewide scans, provide a basis for planning future investigations. The major areas warranting further study involve fine mapping to narrow down 3 regions on 2q, 3p, and 12q that may contain "novel" hypertension genes, additional typing of some biological candidate genes to determine whether they are the sources of these and other signals, multilocus investigations to understand how and to what extent some of these candidates may interact, and multivariate studies to characterize any pleiotropy.

Local release of ATP into the arterial inflow and venous drainage of human skeletal muscle: insight from ATP determination with the intravascular microdialysis technique

DEFF Research Database (Denmark)

Mortensen, Stefan; Thaning, Pia; Nyberg, Michael Permin

2011-01-01

is released into plasma, we measured plasma [ATP] with the intravascular microdialysis technique at rest and during dynamic exercise (normoxia and hypoxia), passive exercise, thigh compressions and arterial ATP, tyramine and ACh infusion in a total of 16 healthy young men. Femoral arterial and venous...

Human skeletal muscle fatty acid and glycerol metabolism during rest, exercise and recovery

DEFF Research Database (Denmark)

Van Hall, Gerrit; Sacchetti, M; Rådegran, G

2002-01-01

glycerol uptake was observed, which was substantially higher during exercise. Total body skeletal muscle FA and glycerol uptake/release was estimated to account for 18-25 % of whole body R(d) or R(a). In conclusion: (1) skeletal muscle FA and glycerol metabolism, using the leg arterial-venous difference......This study was conducted to investigate skeletal muscle fatty acid (FA) and glycerol kinetics and to determine the contribution of skeletal muscle to whole body FA and glycerol turnover during rest, 2 h of one-leg knee-extensor exercise at 65 % of maximal leg power output, and 3 h of recovery....... To this aim, the leg femoral arterial-venous difference technique was used in combination with a continuous infusion of [U-(13)C]palmitate and [(2)H(5)]glycerol in five post-absorptive healthy volunteers (22 +/- 3 years). The influence of contamination from non-skeletal muscle tissues, skin and subcutaneous...

Plasmodium falciparum malaria associated with ABO blood ...

African Journals Online (AJOL)

The present study was carried out to investigate the relationship between blood group types and P. falciparum malaria, as well as malaria preventive measures. The venous blood specimens were collected, processed, Giemsa-stained and examined microscopically. ABO groups were determined by agglutination test using ...

Deep venous thrombus characterization: ultrasonography, elastography and scattering operator

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Thibaud Berthomier

2017-04-01

Full Text Available A thrombus or a blood clot is the result of blood coagulation which is a natural process to prevent bleeding. An inappropriate formation of a thrombus in a deep vein is known as Deep Venous Thrombosis (DVT. The main complication of a DVT is a Pulmonary Embolism (PE which occurs when a thrombus breaks loose and travels to the lungs. DVT, PE, or both are also known as Venous thromboembolism (VTE. It affects an estimated 300,000–600,000 Individuals just in the United States per year and can cause considerable morbidity and mortality. This multifactorial disease related to advanced age, immobility, surgery or obesity is an important public health issue. Our project is looking to link the VTE epidemiology (risk factors, patient history, PE to the thrombus structure. To reach our goals, we are collecting ultrasonography (echogenicity and elastography (stiffness of human thrombus. This manuscript describes our approach to create and preprocess a database using Toshiba Aplio 500. Our approaches to characterize the thrombus structure with ultrasound images are also described. The feature extraction is made with the scattering operator. Obtained features are then reduced using Principal Component Analysis and are analyzed to evaluate our approach.

How High Blood Pressure Can Lead to Stroke

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... Disease Venous Thromboembolism Aortic Aneurysm More How High Blood Pressure Can Lead to Stroke Updated:Jan 29,2018 ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

Slower lower limb blood pooling in young women with orthostatic intolerance.

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Lindenberger, Marcus; Länne, Toste

2015-01-01

What is the central question of this study? Orthostatic stress is mostly caused by venous blood pooling in the lower limbs. Venous distension elicits sympathetic responses, and increased distension speed enhances the cardiovascular response. We examine whether lower limb blood pooling rate during lower body negative pressure is linked to orthostatic intolerance. What is the main finding and its importance? A similar amount of blood was pooled in the lower limb, but at a slower rate in women who developed signs of orthostatic intolerance. The difference in blood pooling rate increased with orthostatic stress and was most prominent at a presyncope-inducing level of lower body negative pressure. The findings have implications for the pathophysiology as well as treatment of orthostatic intolerance. Vasovagal syncope is common in young women, but its aetiology remains elusive. Orthostatic stress-induced lower limb blood pooling is linked with central hypovolaemia and baroreceptor unloading. Venous distension in the arm elicits a sympathetic response, which is enhanced with more rapid distension. Our aim was to study both the amount and the speed of lower limb pooling during orthostatic stress and its effects on compensatory mechanisms to maintain cardiovascular homeostasis in women with orthostatic intolerance. Twenty-seven healthy women, aged 20-27 years, were subjected to a lower body negative pressure (LBNP) of 11-44 mmHg. Five women developed symptoms of vasovagal syncope (orthostatic intolerant) and were compared with the remaining women, who tolerated LBNP well (orthostatic tolerant). Lower limb blood pooling, blood flow and compensatory mobilization of venous capacitance blood were measured. Lower body negative pressure induced equal lower limb blood pooling in both groups, but at a slower rate in orthostatic intolerant women (e.g. time to 50% of total blood pooling, orthostatic intolerant 44 ± 7 s and orthostatic tolerant 26 ± 2 s; P intolerant women (P = 0

Effects of walking in deep venous thrombosis: a new integrated solid and fluid mechanics model.

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López, Josep M; Fortuny, Gerard; Puigjaner, Dolors; Herrero, Joan; Marimon, Francesc; Garcia-Bennett, Josep

2017-05-01

Deep venous thrombosis (DVT) is a common disease. Large thrombi in venous vessels cause bad blood circulation and pain; and when a blood clot detaches from a vein wall, it causes an embolism whose consequences range from mild to fatal. Walking is recommended to DVT patients as a therapeutical complement. In this study the mechanical effects of walking on a specific patient of DVT were simulated by means of an unprecedented integration of 3 elements: a real geometry, a biomechanical model of body tissues, and a computational fluid dynamics study. A set of computed tomography images of a patient's leg with a thrombus in the popliteal vein was employed to reconstruct a geometry model. Then a biomechanical model was used to compute the new deformed geometry of the vein as a function of the fiber stretch level of the semimembranosus muscle. Finally, a computational fluid dynamics study was performed to compute the blood flow and the wall shear stress (WSS) at the vein and thrombus walls. Calculations showed that either a lengthening or shortening of the semimembranosus muscle led to a decrease of WSS levels up to 10%. Notwithstanding, changes in blood viscosity properties or blood flow rate may easily have a greater impact in WSS. Copyright © 2016 John Wiley & Sons, Ltd.

The effect of altering pulmonary blood flow on pulmonary gas exchange in the turtle Trachemys (Pseudemys) scripta.

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Hopkins, S R; Wang, T; Hicks, J W

1996-10-01

In resting reptiles, the PO2 of pulmonary venous return (PLAO2; left atrial blood) may be 20 mmHg (1 mmHg = 0.1333 kPa) lower than the PO2 of gas in the lung. This level of PO2 is considerably higher than that observed in resting mammals and birds and results from ventilation-perfusion (V/Q) heterogeneity, pulmonary diffusion limitation and intrapulmonary shunting. However, the relative contribution of each of these factors is unknown. Many reptiles, particularly chelonians, exhibit an intermittent ventilation pattern where pulmonary blood flow (QL) increases during the ventilatory periods and, therefore, we hypothesized that V/Q matching would improve with increasing QL. We applied the multiple inert gas elimination technique in anaesthetized turtles at 22 degrees C. Turtles were continuously ventilated at a rate of 140 ml kg-1 min-1, equivalent to the rate of ventilation within a ventilatory period. Trace amounts of six inert gases were infused through the jugular vein. Blood samples from the pulmonary artery and the left atrium and mixed expired gases were collected for analysis. QL was reduced by a factor of six (low flow) using a vascular occluder placed around the common pulmonary artery or increased by a factor of two (high flow) through bolus injection of adrenaline. V/Q heterogeneity was significantly reduced with increasing pulmonary blood flow (P means +/- S.E.M.) and PLAO2 increased significantly (P < 0.05) from 88 +/- 17 mmHg (low flow) to 120 +/- 14 mmHg (high flow). There was evidence of pulmonary diffusion limitation under all conditions, which was unchanged with increasing blood flow. These findings suggest that increased pulmonary blood flow during a ventilatory period results in both temporal and spatial matching of ventilation and perfusion, without altering pulmonary diffusion limitation.

Attempts at estimating mixed venous carbon dioxide tension by the single-breath method.

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Ohta, H; Takatani, O; Matsuoka, T

1989-01-01

The single-breath method was originally proposed by Kim et al. [1] for estimating the blood carbon dioxide tension and cardiac output. Its reliability has not been proven. The present study was undertaken, using dogs, to compare the mixed venous carbon dioxide tension (PVCO2) calculated by the single-breath method with the PVCO2 measured in mixed venous blood, and to evaluate the influence of variations in the exhalation duration and the volume of expired air usually discarded from computations as the deadspace. Among the exhalation durations of 15, 30 and 45 s tested, the 15 s duration was found to be too short to obtain an analyzable O2-CO2 curve, but at either 30 or 45 s, the calculated values of PVCO2 were comparable to the measured PVCO2. A significant agreement between calculated and measured PVCO2 was obtained when the expired gas with PCO2 less than 22 Torr was considered as deadspace gas.

Arterial supply, venous drainage and collateral circulation in the nose of the anaesthetized dog.

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Lung, M A; Wang, J C

1987-01-01

1. In pentobarbitone-anaesthetized dogs, nasal blood flows were measured with electromagnetic flow sensors. 2. The terminal internal maxillary artery was found to supply 22 +/- 2.2 ml min-1 (one side) to the nasal mucosa via the sphenopalatine and major palatine branches; the artery was found to receive multiple supply routes from common carotid, vertebral and subclavian arteries. 3. Nasal mucosa was found to receive collateral flow from contralateral terminal internal maxillary artery (about 5 to 10% of normal flow) and branches of subclavian arteries (about 36% of normal flow). 4. Nasal mucosa was found to have two venous systems: the low-flow (12 +/- 1.0 ml min-1; both sides) and low-pressure (7 +/- 0.6 mmHg) sphenopalatine veins draining the posterior nasal cavity and the high-flow (30 +/- 1.4 ml min-1; both sides) and high-pressure (17 +/- 1.0 mmHg) dorsal nasal veins draining the anterior nasal cavity. 5. PO2 of nasal venous blood was found to range from 62 +/- 2.9 mmHg to 65 +/- 3.4 mmHg. During nitrogen challenge to the nose, the sphenopalatine venous PO2 dropped to 35 +/- 3.0 mmHg while the dorsal nasal venous PO2 remained unchanged, suggesting that the sphenopalatine veins were responsible for draining capillary flow and dorsal nasal veins arteriovenous anastomotic flow as well. 6. Microscopic examination of the vascular casts confirmed that arteriovenous anastomoses were located only in the anterior nasal cavity. Images Fig. 5 Plate 1 Plate 2 PMID:3443958

Fingertip Reconstruction Using Free Toe Tissue Transfer Without Venous Anastomosis

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Won Young Yoon

2012-09-01

Full Text Available BackgroundThis study was designed to introduce the feasibility of toe tissue transfer without venous outflow for fingertip reconstruction.MethodsFive cases of fingertip defects were treated successfully with this method. Four cases were traumatic fingertip defects, and one case was a hook-nail deformity. The lateral pulp of a great toe or medioinferior portion of a second toe was used as the donor site. An arterial pedicle was dissected only within the digit and anastomosis was performed within 2 cm around the defect margin. The digital nerve was repaired simultaneously. No additional dissection of the dorsal or volar pulp vein was performed in either the donor or recipient sites. Other surgical procedures were performed following conventional techniques. Postoperative venous congestion was monitored with pulp temperature, color, and degree of tissue oxygen saturation. Venous congestion was decompressed with a needle-puncture method intermittently, but did not require continuous external bleeding for salvage.ResultsVenous congestion was observed in all the flaps, but improved within 3 or 4 days postoperatively. The flap size was from 1.5×1.5 cm2 to 2.0×3.0 cm2. The mean surgical time was 2 hours and 20 minutes. A needle puncture was carried out every 2 hours during the first postoperative day, and then every 4 hours thereafter. The amount of blood loss during each puncture procedure was less than 0.2 mL. In the long-term follow-up, no flap atrophy was observed.ConclusionsWhen used properly, the free toe tissue transfer without venous anastomosis method can be a treatment option for small defects on the fingertip area.

Continuous insulin administration via complex central venous catheter infusion tubing is another risk factor for blood glucose imbalance. A retrospective study.

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Maury, Eric; Vitry, Paola; Galbois, Arnauld; Ait-Oufella, Hafid; Baudel, Jean-Luc; Guidet, Bertrand; Offenstadt, Georges

2012-06-14

We assessed the potential impact of infusion tubing on blood glucose imbalance in ICU patients given intensive insulin therapy (IIT). We compared the incidence of blood glucose imbalance in patients equipped, in a nonrandomized fashion, with either conventional tubing or with a multiport infusion device. We retrospectively analyzed the nursing files of 35 patients given IIT through the distal line of a double-lumen central venous catheter. A total of 1389 hours of IIT were analyzed for occurrence of hypoglycemic events [defined as arterial blood glucose below 90 mg/dL requiring discontinuation of insulin]. Twenty-one hypoglycemic events were noted (density of incidence 15 for 1000 hours of ITT). In 17 of these 21 events (81%), medication had been administered during the previous hour through the line connected to the distal lumen of the catheter. Conventional tubing use was associated with a higher density of incidence of hypoglycemic events than multiport infusion device use (23 vs. 2 for 1,000 hours of IIT; rate ratio = 11.5; 95% confidence interval, 2.71-48.8; p tubing carrying other medications can lead to the delivery of significant amounts of unscheduled products. Hypoglycaemia observed during IIT could be related to this phenomenon. The use of a multiport infusion device with a limited dead volume could limit hypoglycemia in patients on IIT.

Resting-State Functional Connectivity and Cognitive Impairment in Children with Perinatal Stroke

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Nigul Ilves

2016-01-01

Full Text Available Perinatal stroke is a leading cause of congenital hemiparesis and neurocognitive deficits in children. Dysfunctions in the large-scale resting-state functional networks may underlie cognitive and behavioral disability in these children. We studied resting-state functional connectivity in patients with perinatal stroke collected from the Estonian Pediatric Stroke Database. Neurodevelopment of children was assessed by the Pediatric Stroke Outcome Measurement and the Kaufman Assessment Battery. The study included 36 children (age range 7.6–17.9 years: 10 with periventricular venous infarction (PVI, 7 with arterial ischemic stroke (AIS, and 19 controls. There were no differences in severity of hemiparesis between the PVI and AIS groups. A significant increase in default mode network connectivity (FDR 0.1 and lower cognitive functions (p<0.05 were found in children with AIS compared to the controls and the PVI group. The children with PVI had no significant differences in the resting-state networks compared to the controls and their cognitive functions were normal. Our findings demonstrate impairment in cognitive functions and neural network profile in hemiparetic children with AIS compared to children with PVI and controls. Changes in the resting-state networks found in children with AIS could possibly serve as the underlying derangements of cognitive brain functions in these children.

Filterability of freshly-collected sickle erythrocytes under venous oxygen pressure without exposure to air.

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Shah, Siddharth; Acholonu, Rhonda Graves; Ohene-Frempong, Kwaku; Asakura, Toshio

2015-12-01

We previously found that blood samples collected from steady-state patients with sickle cell disease (SCD) without exposure to air contain a new type of reversibly sickled cells (RSCs) with blunt edges at a level of as high as 78%. Since partial oxygenation of once-deoxygenated sickled cells with pointy edges to near venous oxygen pressure generates similar sickled cells with blunt edges in vitro, we named them as partially oxygenated sickled cells (POSCs). On the other hand, partial deoxygenation of once-oxygenated SS cells to venous oxygen pressure generates partially deoxygenated sickled cells (PDSCs) with pointy edges. In this study, we obtained blood samples from 6 steady-state patients with SCD under venous oxygen pressure without exposure to air, subjected them to various oxygenation/deoxygenation/reoxygenation cycles, and studied their filterability through a membrane filter with pore diameter of 3μm, the theoretical minimum diameter of a capillary. Our results indicated that discocytes, POSCs with blunt edges, and irreversibly sickled cells could deform and pass through the filter, while PDSCs with pointy edges were rigid and could not. The filterability of SS cells seems to be related to the length and amount of deoxy-hemoglobin S fibers in the cells. Copyright © 2015. Published by Elsevier Inc.

Importance of the spinal venous system in the formation of metastases

International Nuclear Information System (INIS)

Gowin, W.

1983-01-01

The vertebral veins and their anastomoses to the other venous vascular regions are presented in their anatomy, physiological and pathophysiological function, with a special reference to the spreading of tumor cells through the veins of the vertebral column. The causes of the accumulation of metastases in the trunk skeleton and brain is pointed out by malignant tumors of the prostata, of the ren, of the lung, of the mamma, of the genital organs and the thyroid gland. The signification of the vertebral venous system as a spread of metastases is emphasized under consideration of the tumor cell kinetics in the blood-flow and the different forms of the metastatic formations, and is verifying by experienced clinical cases and reviews of the literature. (orig.) [de

In hypertrophic cardiomyopathy reduction of relative resting myocardial blood flow is related to late enhancement, T2-signal and LV wall thickness.

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Katja Hueper

Full Text Available To quantify resting myocardial blood flow (MBF in the left ventricular (LV wall of HCM patients and to determine the relationship to important parameters of disease: LV wall thickness, late gadolinium enhancement (LGE, T2-signal abnormalities (dark and bright signal, LV outflow tract obstruction and age.Seventy patients with proven HCM underwent cardiac MRI. Absolute and relative resting MBF were calculated from cardiac perfusion MRI by using the Fermi function model. The relationship between relative MBF and LV wall thickness, T2-signal abnormalities (T2 dark and T2 bright signal, LGE, age and LV outflow gradient as determined by echocardiography was determined using simple and multiple linear regression analysis. Categories of reduced and elevated perfusion in relation to non- or mildly affected reference segments were defined, and T2-signal characteristics and extent as well as pattern of LGE were examined. Statistical testing included linear and logistic regression analysis, unpaired t-test, odds ratios, and Fisher's exact test.804 segments in 70 patients were included in the analysis. In a simple linear regression model LV wall thickness (p<0.001, extent of LGE (p<0.001, presence of edema, defined as focal T2 bright signal (p<0.001, T2 dark signal (p<0.001 and age (p = 0.032 correlated inversely with relative resting MBF. The LV outflow gradient did not show any effect on resting perfusion (p = 0.901. Multiple linear regression analysis revealed that LGE (p<0.001, edema (p = 0.026 and T2 dark signal (p = 0.019 were independent predictors of relative resting MBF. Segments with reduced resting perfusion demonstrated different LGE patterns compared to segments with elevated resting perfusion.In HCM resting MBF is significantly reduced depending on LV wall thickness, extent of LGE, focal T2 signal abnormalities and age. Furthermore, different patterns of perfusion in HCM patients have been defined, which may represent different stages of

A PILOT STUDY ON THE EFFECTS OF MAGNESIUM SUPPLEMENTATION WITH HIGH AND LOW HABITUAL DIETARY MAGNESIUM INTAKE ON RESTING AND RECOVERY FROM AEROBIC AND RESISTANCE EXERCISE AND SYSTOLIC BLOOD PRESSURE

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Lindsy S. Kass

2013-03-01

Full Text Available The effects of magnesium supplementation on blood pressure (BP have been studied for over 25 years and results have been inconsistent. Blood pressure reductions in randomized studies have varied from 12 mmHg reductions to no reduction. The objective of this pilot intervention was to investigate the effect of magnesium supplementation on systolic blood pressure whilst resting and during recovery from aerobic and resistance exercise and on performance. A further objective was to see whether the effect of a high vs low habitual dietary magnesium intake affected these results. Sixteen male volunteers were randomly assigned to either a 300 mg·d-1 magnesium oxide supplementation (MO or a control group (CG for 14 days. Resting blood pressure (BP and heart rate (HR were measured before subjects performed a maximal 30 minute cycle, immediately followed by three x 5 second isometric bench press, both at baseline and after the intervention. Blood pressure and heart rate were recorded immediately post exercise and after five minutes recovery. A 3 day food diary was recorded for all subjects to measure dietary magnesium intake. At the end of the intervention, the supplemented group, had a reduction in mean resting systolic BP by 8.9 mmHg (115.125 ± 9.46 mmHg, p = 0.01 and post exercise by 13 mmHg (122.625 ± 9. 88 mmHg, p = 0.01. Recovery BP was 11.9 mmHg lower in the intervention group compared to control (p = 0.006 and HR decreased by 7 beats per minute in the experimental group (69.0 ± 11.6 bpm, p = 0. 02. Performance indicators did not change within and between the groups. Habitual dietary magnesium intake affected both resting and post exercise systolic BP and the subsequent effect of the magnesium supplementation. These results have an implication in a health setting and for health and exercise but not performance.

Extrahepatic portal venous obstruction: The effects of early ligation of splenic artery during splenectomy.

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Gazula, Suhasini; Pawar, D K; Seth, T; Bal, C S; Bhatnagar, V

2009-10-01

To objectively demonstrate the gain in blood volume and blood components following early ligation of splenic artery during splenectomy and splenorenal shunts in children with extra hepatic portal venous obstruction (EHPVO). Twenty-eight children (20 males and 8 females, mean age: 9.9 (+/-3.2) years) with EHPVO and hypersplenism were recruited. We followed a protocol of systematically locating and ligating the splenic artery first, followed by a 30-minute waiting period to allow the massive spleen to decongest via the splenic vein and venous collaterals and then completing the splenectomy by standard procedure. No intravenous fluid was administered during this 30-minute period. Blood samples were drawn just prior to splenic artery ligation and soon after splenectomy for the estimation of hematological and biochemical parameters. We noticed a highly significant increase in the hemoglobin, hematocrit, leukocyte, platelet, and RBC counts by early ligation of the splenic artery (p platelet count was equivalent to a platelet transfusion of atleast 4 units of platelet concentrates in an adult. There is a positive correlation between the splenic weight and the platelet gain (p= 0.0568) and the splenic volume on preoperative imaging and the platelet gain (p= 0.0251). Early ligation of the splenic artery during splenectomy results in passive splenic decongestion and thereby a significant gain in blood components. This protocol appears to be a feasible blood conservation method to avoid blood transfusions in this group of hypersplenic EHPVO patients.

Complications of central venous stenosis due to permanent central venous catheters in children on hemodialysis.

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Rinat, Choni; Ben-Shalom, Efrat; Becker-Cohen, Rachel; Feinstein, Sofia; Frishberg, Yaacov

2014-11-01

Central venous catheters are frequently used as access for hemodialysis (HD) in children. One of the known complications is central venous stenosis. Although this complication is not rare, it is often asymptomatic and therefore unacknowledged. Superior vena cava (SVC) stenosis is obviously suspected in the presence of upper body edema, but several other signs and symptoms are often unrecognized as being part of this syndrome. We describe four patients with various manifestations of central venous stenosis and SVC syndrome. These sometimes life- or organ-threatening conditions include obstructive sleep apnea, unresolving stridor, increased intracranial pressure, increased intraocular pressure, right-sided pleural effusion, protein-losing enteropathy and lymphadenopathy. The temporal relationship of these complications associated with the use of central venous catheters and documentation of venous stenosis, together with their resolution after alleviation of high venous pressure, points to a causal role. We suggest pathophysiological mechanisms for the formation of each of these complications. In patients with occlusion of the SVC, various unexpected clinical entities can be caused by high central venous pressure. As often the etiology is not obvious, a high index of suspicion is needed as in some cases prompt alleviation of the high pressure is mandatory.

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.

Basic studies on the estimation of the capacitance of human pulmonary 'venous' system using radionuclide angiocardiography

International Nuclear Information System (INIS)

Fujiwara, Hideki; Gotoh, Kohshi; Suzuki, Takahiko; Ohsumi, Yukio; Yagi, Yasuo; Hirakawa, Senri

1993-01-01

To establish the methodology to assess the capacitance of human pulmonary 'venous' system, using radionuclide angiocardiography and passive leg elevation, some basic aspects of the method were investigated. The pulmonary 'venous' system consisted of pulmonary veins and the left atrium. A short segment of the volume-pressure curve in human pulmonary 'venous' system was obtained as a line connecting the 2 points. (1) Pulmonary 'venous' volume-mean pulmonary capillary wedge pressure plot (P 'V' V-PCW plot) in supine position, where P 'V' V=0.7 x PBV. Pulmonary blood volume (PBV) was obtained by radionuclide angiocardiography, while mean pulmonary capillary wedge pressure (PCW) was simultaneously recorded by a floating catheter. (2) ΔP 'V' V-ΔPCW relation where ΔP 'V' V=0.8 x ΔPBV. Increment of the pulmonary blood volume (ΔPBV) during passive elevation of legs was measured from the baseline PBV and the percentage increase in the radioactivity over the right anterior chest during the leg elevation, after correction for (a) radioactivity from chest wall origin, and for (b) attenuation of the radioactive beams by the lung and the anterior chest wall. ΔPCW was the increase in PCW during leg elevation. The present study focussed on the details of the two corrections, (a) and (b), using, in parts, mechanical models. The present study also focussed on the reproducibility of the ΔP 'V' V, ΔPCW and Cp'v' (compliance of the pulmonary 'venous' system). The coefficient of variation was ±23% in ΔP 'V' V, ±18% in ΔPCW and ±18% in Cp'v', indicating a fair degree of reproducibility. (author)

Femoral venous catheters: a safe alternative for delivering parenteral alimentation.

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Friedman, B; Kanter, G; Titus, D

1994-04-01

Femoral vein catheterization is an alternative method of obtaining central venous access. Placement of femoral venous catheters (FVCs) is possible in the majority of patients, suitable for most indications, and associated with a low complication rate during insertion. We wished to determine the incidence of infections or other complications resulting when parenteral nutrition was delivered through FVCs. Fifty-two patients were followed from a hospital-wide population including patients in the critical care units. Triple-lumen catheters were placed by using the sterile Seldinger technique, and sites were examined daily for inflammation. Bacteriologic surveillance was accomplished by submitting the catheter tip for semiquantitative cultures. If catheter line sepsis was suspected, blood samples for cultures were drawn through the catheter and peripherally. The rate of occurrence of colonized catheters was 9.6% (five of 52), and catheter sepsis was found in one case (1.9%). Other than inflammation at six (11.5%) of 52 catheter sites, noninfectious complications of FVCs were not found. On the basis of these findings, we consider FVC-delivered parenteral alimentation a safe and effective alternative to other forms of central venous access.

Simultaneous estimation of arterial and venous oxygen saturation using a camera

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van Gastel, Mark; Liang, Hangbing; Stuijk, Sander; de Haan, Gerard

2018-02-01

Optical monitoring of arterial blood oxygenation, SpO2, using cameras has recently been shown feasible by measuring the relative amplitudes of the remotely sensed PPG waveforms captured at different wavelengths. SvO2 measures the venous blood oxygenation which together with SpO2 provides an indication of tissue oxygen consumption. In contrast to SpO2 it usually still requires a blood sample from a pulmonary artery catheter. In this work we present a method which suggests simultaneous estimation of SpO2 and SvO2 with a camera. Contrary to earlier work, our method does not require external cuffs leading to better usability and improved comfort. Since the arterial blood varies synchronously with the heart rate, all frequencies outside the heart rate band are typically filtered out for SpO2 measurements. For SvO2 estimation, we include intensity variations in the respiratory frequency range since respiration modulates venous blood due to intrathoracic pressure variations in the chest and abdomen. Consequently, under static conditions, the two dominant components in the PPG signals are respiration and pulse. By measuring the amplitude ratios of these components, it seems possible to monitor both SpO2 and SvO2 continuously. We asked healthy subjects to follow an auditory breathing pattern while recording the face and hand. Results show a difference in estimated SpO2 and SvO2 values in the range 5-30 percent for both anatomical locations, which is normal for healthy people. This continuous, non-contact, method shows promise to alert the clinician to a change in patient condition sooner than SpO2 alone.

Caffeine reduces resting-state BOLD functional connectivity in the motor cortex.

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Rack-Gomer, Anna Leigh; Liau, Joy; Liu, Thomas T

2009-05-15

In resting-state functional magnetic resonance imaging (fMRI), correlations between spontaneous low-frequency fluctuations in the blood oxygenation level dependent (BOLD) signal are used to assess functional connectivity between different brain regions. Changes in resting-state BOLD connectivity measures are typically interpreted as changes in coherent neural activity across spatially distinct brain regions. However, this interpretation can be complicated by the complex dependence of the BOLD signal on both neural and vascular factors. For example, prior studies have shown that vasoactive agents that alter baseline cerebral blood flow, such as caffeine and carbon dioxide, can significantly alter the amplitude and dynamics of the task-related BOLD response. In this study, we examined the effect of caffeine (200 mg dose) on resting-state BOLD connectivity in the motor cortex across a sample of healthy young subjects (N=9). We found that caffeine significantly (pcaffeine. These results suggest that caffeine usage should be carefully considered in the design and interpretation of resting-state BOLD fMRI studies.

The resting sites and blood-meal sources of Anopheles minimus in Taiwan

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Chen Yung-Chen

2008-06-01

Full Text Available Abstract Background The WHO declared Taiwan free from malaria in 1965, but in 2003 the reporting of two introduced cases in a rural area suggested a possible local transmission of this disease. Therefore, understanding the resting sites and the blood sources of Anopheles minimus is crucial in order to provide information for implementing vector control strategies. Methods During a two-year survey, mosquitoes were collected in houses and their surrounding areas and at the bank of larval habitats by backpack aspirators in 17 villages in rural areas of southern and eastern Taiwan for 1 hr. On the same day, blacklight traps were hung downward overnight. Blood-fed mosquito samples were analysed by PCR. Results Of the 195 total households surveyed by backpack aspirators, no Anopheles adults were collected inside the houses, while a single Anopheles minimus and a single Anopheles maculatus were collected outside of the houses. On the same day, 23 An. minimus, two An. maculatus, two Anopheles ludlowae, two Anopheles sinensis, and one Anopheles tessellatus were collected along the bank of larval habitats. In blacklight traps hung outside of the houses in the villages, 69 An. minimus, 62 An. ludlowae, 31 An. sinensis, and 19 An. maculatus were collected. In larval habitats, 98 An. ludlowae, 64 An. minimus, 49 An. sinensis, and 14 An. maculatus were collected. Of a total of 10 blood-fed samples, An. minimus fed on four animals including bovine (60%, dogs (20%, pig (10%, and non-chicken avian (10%. Conclusion Anopheles minimus, an opportunist feeder in Taiwan, was not collected inside the houses, but was found outside of the houses in villages and surrounding larval habitats. Therefore, an outdoor transmission of malaria is likely to occur and, thus, the bed nets, which are favoured for controlling the late biting of An. minimus, should be a very efficient and effective method for those local residents who sleep outdoors. Additionally, space spray of

The prevalence of malarial parasitaemia among blood donors in ...

African Journals Online (AJOL)

BACKGROUND: Blood serves as a vehicle for transmission of blood-borne pathogens and transfusion-associated malaria is a major concern in malaria endemic countries. The study was conducted to determine the prevalence of malaria parasite among blood donors in Zaria, Nigeria. METHODS: A total of 160 venous ...

Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

NARCIS (Netherlands)

van Beest, Paul A.; van der Schors, Alice; Liefers, Henriëtte; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michaël A.; Spronk, Peter E.

2012-01-01

Objective: The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design: Prospective observational controlled study. Setting: Nonacademic university-affiliated

Neuromuscular and blood lactate responses to squat power training with different rest intervals between sets.

Science.gov (United States)

Martorelli, André; Bottaro, Martim; Vieira, Amilton; Rocha-Júnior, Valdinar; Cadore, Eduardo; Prestes, Jonato; Wagner, Dale; Martorelli, Saulo

2015-06-01

Studies investigating the effect of rest interval length (RI) between sets on neuromuscular performance and metabolic response during power training are scarce. Therefore, the purpose of this study was to compare maximal power output, muscular activity and blood lactate concentration following 1, 2 or 3 minutes RI between sets during a squat power training protocol. Twelve resistance-trained men (22.7 ± 3.2 years; 1.79 ± 0.08 cm; 81.8 ± 11.3 kg) performed 6 sets of 6 repetitions of squat exercise at 60% of their 1 repetition maximum. Peak and average power were obtained for each repetition and set using a linear position transducer. Muscular activity and blood lactate were measured pre and post-exercise session. There was no significant difference between RI on peak power and average power. However, peak power decreased 5.6%, 1.9%, and 5.9% after 6 sets using 1, 2 and 3 minutes of RI, respectively. Average power also decreased 10.5% (1 min), 2.6% (2 min), and 4.3% (3 min) after 6 sets. Blood lactate increased similarly during the three training sessions (1-min: 5.5 mMol, 2-min: 4.3 mMol, and 3-min: 4.0 mMol) and no significant changes were observed in the muscle activity after multiple sets, independent of RI length (pooled ES for 1-min: 0.47, 2-min: 0.65, and 3-min: 1.39). From a practical point of view, the results suggest that 1 to 2 minute of RI between sets during squat exercise may be sufficient to recover power output in a designed power training protocol. However, if training duration is malleable, we recommend 2 min of RI for optimal recovery and power output maintenance during the subsequent exercise sets. Key pointsThis study demonstrates that 1 minute of RI between sets is sufficient to maintain maximal power output during multiple sets of a power-based exercise when it is composed of few repetitions and the sets are not performed until failure. Therefore, a short RI should be considered when designing training programs for the development of

Hypertension (High Blood Pressure)

Science.gov (United States)

... Safe Videos for Educators Search English Español Hypertension (High Blood Pressure) KidsHealth / For Teens / Hypertension (High Blood Pressure) What's ... rest temperature diet emotions posture medicines Why Is High Blood Pressure Bad? High blood pressure means a person's heart ...

Acute sodium bicarbonate loading has negligible effects on resting and exercise blood pressure but causes gastrointestinal distress.

Science.gov (United States)

Kahle, Laura E; Kelly, Patrick V; Eliot, Kathrin A; Weiss, Edward P

2013-06-01

Oral ingestion of sodium bicarbonate (bicarbonate loading) has acute ergogenic effects on short-duration, high-intensity exercise. Because sodium bicarbonate is 27% sodium, ergogenic doses (ie, 300 mg∙kg⁻¹) result in sodium intakes well above the Dietary Reference Intakes upper limit of 2300 mg/day. Therefore, it is conceivable that bicarbonate loading could have hypertensive effects. Therefore, we performed a double-blind crossover trial to evaluate the hypothesis that bicarbonate loading increases resting and exercise blood pressure (BP). A secondary hypothesis was that bicarbonate loading causes gastrointestinal distress. Eleven endurance-trained men and women (exercise frequency, 4.6 ± 0.4 sessions/wk; duration, 65 ± 6 min/session) underwent testing on two occasions in random sequence: once after bicarbonate loading (300 mg∙kg⁻¹) and once after placebo ingestion. BP and heart rate were measured before bicarbonate or placebo consumption, 30 minutes after consumption, during 20 min of steady state submaximal cycling exercise, and during recovery. Bicarbonate loading did not affect systolic BP during rest, exercise, or recovery (P = .38 for main treatment effect). However, it resulted in modestly higher diastolic BP (main treatment effect, +3.3 ± 1.1 mmHg, P = .01) and higher heart rate (main treatment effect, +10.1 ± 2.4 beats per minute, P = .002). Global ratings of gastrointestinal distress severity (0-10 scale) were greater after bicarbonate ingestion (5.1 ± 0.5 vs 0.5 ± 0.2, P bicarbonate loading. In conclusion, although a single, ergogenic dose of sodium bicarbonate does not appear to have acute, clinically important effects on resting or exercise BP, it does cause substantial gastrointestinal distress. Copyright © 2013 Elsevier Inc. All rights reserved.

A novel approach to the management of critically ill neonatal Ebstein′s anomaly: Veno-venous extracorporeal membrane oxygenation to promote right ventricular recovery

Directory of Open Access Journals (Sweden)

Holly Bauser-Heaton

2015-01-01

Full Text Available This is the first report of the use of veno-venous extracorporeal membrane oxygenation in a neonate with severe Ebstein′s anomaly. The report suggests the use of veno-venous extracorporeal membrane oxygenation in the immediate neonatal period may be a useful therapy in severe Ebstein′s anomaly. By providing adequate oxygenation independent of the patient′s native pulmonary blood flow, veno-venous extracorporeal membrane oxygenation allows the pulmonary vascular resistance to decrease and may promote right ventricular recovery.

Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation

NARCIS (Netherlands)

van Beest, Paul A.; van der Schors, Alice; Liefers, Henriette; Coenen, Ludo G. J.; Braam, Richard L.; Habib, Najib; Braber, Annemarije; Scheeren, Thomas W. L.; Kuiper, Michael A.; Spronk, Peter E.

2012-01-01

Objective:  The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients. Design:  Prospective observational controlled study. Setting:  Nonacademic university-affiliated

Automatic collection of bovine blood samples | Hale | South African ...

African Journals Online (AJOL)

A technique is described which allows automatic collection of jugular venous blood from tethered cows. In this system, blood is pumped continuously from an intravenous cannula which has a double lumen while an anticoagulant is pumped through the second opening. Diluted blood is collected in a fraction collector which ...

Successful medical management of emphysematous gastritis with concomitant portal venous air: a case report

Directory of Open Access Journals (Sweden)

Weiss Stan L

2010-05-01

Full Text Available Abstract Introduction The causes of diffuse abdominal pain following pelvic surgery are numerous. We present a rare case of acute abdominal pain in a woman in the post-partum period. Case presentation A 25-year-old Caucasian woman with neurofibromatosis type 1 presented to our hospital with diffuse abdominal pain immediately after a cesarean section. The patient was acutely ill and toxic with a fever of 38.8°C, a pulse of 120 beats per minute and a distended abdomen with absent bowel sounds. A computed tomography scan showed air in the wall of the stomach and portal venous system. The patient was successfully treated with intravenous antibiotics, bowel rest and total parenteral nutrition. Conclusion It is rare for a case of emphysematous gastritis associated with portal venous air to be treated successfully without surgery. To the best of our knowledge, to date there has been no reported association of emphysematous gastritis with neurofibromatosis.

Effects of parental smoking on exercise systolic blood pressure in adolescents.

Science.gov (United States)

Hacke, Claudia; Weisser, Burkhard

2015-05-11

In adults, exercise blood pressure seems to be more closely related to cardiovascular risk than resting blood pressure; however, few data are available on the effects of familial risk factors, including smoking habits, on exercise blood pressure in adolescents. Blood pressure at rest and during exercise, parental smoking, and other familial risk factors were investigated in 532 adolescents aged 12 to 17 years (14.6±1.5 years) in the Kiel EX.PRESS. (EXercise PRESSure) Study. Exercise blood pressure was determined at 1.5 W/kg body weight using a standardized submaximal cycle ergometer test. Mean resting blood pressure was 113.1±12.8/57.2±7.1 mm Hg, and exercise blood pressure was 149.9±19.8/54.2±8.6 mm Hg. Parental smoking increased exercise systolic blood pressure (+4.0 mm Hg, 3.1 to 4.9; P=0.03) but not resting blood pressure of the subjects (adjusted for age, sex, height, body mass index percentile, fitness). Parental overweight and familial hypertension were related to both higher resting and exercise systolic blood pressure values, whereas associations with an inactive lifestyle and a low educational level of the parents were found only with adolescents' blood pressure during exercise. The cumulative effect of familial risk factors on exercise systolic blood pressure was more pronounced than on blood pressure at rest. Parental smoking might be a novel risk factor for higher blood pressure, especially during exercise. In addition, systolic blood pressure during a submaximal exercise test was more closely associated with familial risk factors than was resting blood pressure, even in adolescents. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

High Blood Pressure, Afib and Your Risk of Stroke

Science.gov (United States)

... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More High Blood Pressure, AFib and Your Risk of Stroke Updated:Aug ... have a stroke for the first time have high blood pressure . And an irregular atrial heart rhythm — a condition ...

The Anatomical Correlation between the Internal Venous Vertebral System and the Cranial Venae Cavae in Rabbit.

Science.gov (United States)

Mazensky, David; Petrovova, Eva; Danko, Jan

2013-01-01

The aim of this study was to describe the possible variations in the connection between the internal venous vertebral system and the cranial vena cava in rabbit using corrosion technique. The study was carried out on 40 adult New Zealand white rabbits. The venous system was injected by using Batson's corrosion casting kit number 17. We found the connection between the internal venous vertebral system and the cranial vena cava by means of the vertebral veins and the right azygos vein. The vertebral vein was present as independent tributary in 36 cases (90%). In the rest of the cases, it was found as being double, being triple, or forming a common trunk with other veins. The azygos vein was present as independent tributary of the cranial vena cava in 39 cases (97.5%). We found also a common trunk formed by the junction of the deep cervical vein, the right vertebral vein, and the azygos vein in one case (2.5%). The azygos vein received 6, 7, 8, or 9 pairs of dorsal intercostal veins. Documenting the anatomical variations in the rabbit will aid in the planning of future experimental studies and determining the clinical relevance on such studies.

Regional cerebral blood flow using sup 133 Xenon intra-venous technique, 2; Evaluation of regional cerebral blood flow in patients with cerebrovascular ischemic disease

Energy Technology Data Exchange (ETDEWEB)

Yonekura, Masahiro; Teramoto, Shigeyoshi; Moriyama, Tadayoshi (Nagasaki Chuo National Hospital (Japan))

1990-12-01

Using the {sup 133}Xenon venous method, we have studied the regional cerebral blood flow (rCBF) in 947 patients with cerebrovascular ischemic disease. In 116 stroke or TIA patients with internal carotid artery occlusion or severe stenosis, their rCBF revealed 48.9 ml/100 g/min on average in the group of one side occlusion, 46.7 ml/100 g/min in the group of both sides occlusion. These values reduced approximately 12%, 16% and 15% of the rCBF in healthy volunteers of same age, respectively. In 28 patients with moya moya disease, their rCBF tended to be higher in younger cases and lower with advanced age. In the majority of the cases, their rCBF was age-dependent with 20{similar to}25 ml/100 g/min below the curve of age-matched rCBF of healthy volunteers. The reduction of rCBF was observed in 69 (48.3%) of 143 cases clinically diagnosed as small vessel disease, in 58 (41.4%) of 140 cases with vertebro-basilar insufficiency and in 23 (44.2%) of 52 cases with syncopal attack compared with the rCBF of healthy volunteers. (author).

Protocol for the realization of venous mapping by chronic venous insufficiency in lower limbs under sonographic guide

International Nuclear Information System (INIS)

Blanco Rojas, Diego Jose

2013-01-01

The current state of knowledge is reviewed with respect to the realization of lower limbs venous mapping. Venous mapping is obtained by the use of color and spectral Doppler ultrasound. Doppler ultrasound has provided a precise graphical representation of the superficial and deep venous systems. The performance of the venous mapping is considered essential for the correct handling of venous diseases. The anatomical and pathophysiological basic concepts are defined to realize the sonographic assessment of the veins of the lower limbs. The required technical aspects are revised for the realization of sonographic exploration of the patient with venous insufficiency. Sonographic findings are characterized to support the diagnostic of venous insufficiency of the lower limbs. The CEAP (clinical-etiologic-anatomic-pathophysiologic) classification is utilized to differentiate forms and degrees of severity of the disorder, and has allowed an interinstitutional comparison in clinical studies, the evaluation of treatment and monitoring of patients. A proposal is designed to perform reports that have served of guide surgical to vascular surgeons [es

Human cerebral venous outflow pathway depends on posture and central venous pressure

DEFF Research Database (Denmark)

Gisolf, J; van Lieshout, J J; van Heusden, K

2004-01-01

Internal jugular veins are the major cerebral venous outflow pathway in supine humans. In upright humans the positioning of these veins above heart level causes them to collapse. An alternative cerebral outflow pathway is the vertebral venous plexus. We set out to determine the effect of posture...... and during a Valsalva manoeuvre in both body positions, correlate highly with model simulation of the jugular cross-sectional area (R(2) = 0.97). The results suggest that the cerebral venous flow distribution depends on posture and CVP: in supine humans the internal jugular veins are the primary pathway...

Vascular access in neonatology: peripherally inserted central catheter and peripheral venous catheter

Directory of Open Access Journals (Sweden)

Marcia Lienemann

2014-04-01

The objective of this paper is to present aspects of peripherally inserted central catheter and peripheral venous catheter, highlighting important points in choosing the type of access. For the passage of peripherally inserted central catheter is previously performing specific course necessary, while the primary indication occurs when it is necessary to access the patient's stay for a long period of time. Whereas peripheral venipuncture is the most appropriate in cases of needing an IV line quickly and safely, for the administration of fluids, blood collection, blood transfusion and other.

Effects of cord compression on fetal blood flow distribution and O2 delivery

International Nuclear Information System (INIS)

Itskovitz, J.; LaGamma, E.F.; Rudolph, A.M.

1987-01-01

The authors used the radionuclide microsphere technique in nine fetal lambs to examine the effect of partial cord compression on distribution of cardiac output and O 2 delivery to fetal organs and venous flow patterns. With a 50% reduction in umbilical blood flow the fraction of fetal cardiac output distributed to the brain, heart, carcass, kidneys, and gastrointestinal tract increased. Pulmonary blood flow fell. O 2 delivery to the brain and myocardium was maintained but was reduced to peripheral, renal, and gastrointestinal circulations. Hepatic blood flow decreased and O 2 delivery fell by 75%. The proportion of umbilical venous blood passing through the ductus venosus increased from 43.9 to 71.8%. The preferential distribution of ductus venosus blood flow through the foramen ovale was enhanced and the proportion of O 2 delivery to upper body organs derived from the ductus venosus increased. Abdominal inferior vena caval blood flow increased, and it was also preferentially distributed through the foramen ovale and constituted the major fraction of the arterial blood supply to the upper body organs. Thus cord compression modified the distribution of cardiac output and the patterns of venous returns in the fetus. This pattern of circulatory response differs from that observed with other causes of reduced O 2 delivery

Optoacoustic measurement of central venous oxygenation for assessment of circulatory shock: clinical study in cardiac surgery patients

Science.gov (United States)

Petrov, Irene Y.; Prough, Donald S.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. Nan; Seeton, Roger; Salter, Michael G.; Esenaliev, Rinat O.

2014-03-01

Circulatory shock is a dangerous medical condition, in which blood flow cannot provide the necessary amount of oxygen to organs and tissues. Currently, its diagnosis and therapy decisions are based on hemodynamic parameters (heart rate, blood pressure, blood gases) and mental status of a patient, which all have low specificity. Measurement of mixed or central venous blood oxygenation via catheters is more reliable, but highly invasive and associated with complications. Our previous studies in healthy volunteers demonstrated that optoacoustic systems provide non-invasive measurement of blood oxygenation in specific vessels, including central veins. Here we report our first results of a clinical study in coronary artery bypass graft (CABG) surgery patients. We used a medical-grade OPO-based optoacoustic system developed in our laboratory to measure in real time blood oxygenation in the internal jugular vein (IJV) of these patients. A clinical ultrasound imaging system (GE Vivid e) was used for IJV localization. Catheters were placed in the IJV as part of routine care and blood samples taken via the catheters were processed with a CO-oximeter. The optoacoustic oxygenation data were compared to the CO-oximeter readings. Good correlation between the noninvasive and invasive measurements was obtained. The results of these studies suggest that the optoacoustic system can provide accurate, noninvasive measurements of central venous oxygenation that can be used for patients with circulatory shock.

The effect of EC-IC bypass surgery on resting cerebral blood flow and cerebrovascular reserve capacity studied with stable Xe-CT and acetazolamide test

Energy Technology Data Exchange (ETDEWEB)

Yamashita, T.; Kashiwagi, S.; Nakano, S.; Takasago, T.; Abiko, S.; Shiroyama, Y.; Hayashi, M.; Ito, H. (Yamaguchi Univ. School of Medicine (Japan). Dept. of Neurosurgery)

1991-06-01

Cerebral blood flow (CBF) and cerebrovascular reserve capacity (CRC) were measured by stable xenon computerized tomography (Xe-CT) and acetazolamide test in 15 patients with cerebrovascular disease before and after extracranial-intracranial (EC-IC) bypass surgery for minor stroke, reversible ischemic neurological deficit or transient ischemic attack. All had angiographically shown occlusive lesions of the major arterial trunk. In the present series, global analysis showed that the bypass did not increase the resting rCBF, but did increase the rCRC. We divided the patients into four groups according to the preoperative resting rCBF and rCRC. All 3 patients with normal resting rCBF and reduced rCRC showed postoperative improvement of rCRC. Of 6 patients with reduced CBF and reduced CRC, three had postoperative increase in resting CBF and four had increased CRC. One of two patients with reduced CBF and normal CRC showed only an increase in CRC. We propose that reduced CRC or reduced CBF with reduced CRC are criteria for selection of candidates for bypass surgery. We conclude that Xe-CT with the Diamox test is a useful and simple method for evaluating cerebral hemodynamics. Preoperative grouping with a combination of preoperative resting rCBF and preoperative rCRC is useful for predicting the effect of EC-IC bypass surgery. (orig.).

Single-scan rest/stress imaging: validation in a porcine model with {sup 18}F-Flurpiridaz

Energy Technology Data Exchange (ETDEWEB)

Guehl, Nicolas J.; Normandin, Marc D.; Wooten, Dustin W.; Sitek, Arkadiusk; Shoup, Timothy M.; El Fakhri, Georges; Alpert, Nathaniel M. [Harvard Medical School, Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA (United States); Rozen, Guy; Ruskin, Jeremy [Harvard Medical School, Cardiac Arrhythmia Service, Department of Medicine, Massachusetts General Hospital, Boston, MA (United States); Ptaszek, Leon M. [Harvard Medical School, Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA (United States); Harvard Medical School, Cardiac Arrhythmia Service, Department of Medicine, Massachusetts General Hospital, Boston, MA (United States)

2017-08-15

{sup 18}F-labeled myocardial flow agents are becoming available for clinical application but the ∝2 hour half-life of {sup 18}F complicates their clinical application for rest-stress measurements. The goal of this work is to evaluate in a pig model a single-scan method which provides quantitative rest-stress blood flow in less than 15 minutes. Single-scan rest-stress measurements were made using {sup 18}F-Flurpiridaz. Nine scans were performed in healthy pigs and seven scans were performed in injured pigs. A two-injection, single-scan protocol was used in which an adenosine infusion was started 4 minutes after the first injection of {sup 18}F-Flurpiridaz and followed either 3 or 6 minutes later by a second radiotracer injection. In two pigs, microsphere flow measurements were made at rest and during stress. Dynamic images were reoriented into the short axis view, and regions of interest (ROIs) for the 17 myocardial segments were defined in bull's eye fashion. PET data were fitted with MGH2, a kinetic model with time varying kinetic parameters, in which blood flow changes abruptly with the introduction of adenosine. Rest and stress myocardial blood flow (MBF) were estimated simultaneously. The first 12-14 minutes of rest-stress PET data were fitted in detail by the MGH2 model, yielding MBF measurement with a mean precision of 0.035 ml/min/cc. Mean myocardial blood flow across pigs was 0.61 ± 0.11 mL/min/cc at rest and 1.06 ± 0.19 mL/min/cc at stress in healthy pigs and 0.36 ± 0.20 mL/min/cc at rest and 0.62 ± 0.24 mL/min/cc at stress in the ischemic area. Good agreement was obtained with microsphere flow measurement (slope = 1.061 ± 0.017, intercept = 0.051 ± 0.017, mean difference 0.096 ± 0.18 ml/min/cc). Accurate rest and stress blood flow estimation can be obtained in less than 15 min of PET acquisition. The method is practical and easy to implement suggesting the possibility of clinical translation. (orig.)

Colorectal cancer with venous tumor thrombosis

OpenAIRE

Kensuke Otani; Soichiro Ishihara; Keisuke Hata; Koji Murono; Kazuhito Sasaki; Koji Yasuda; Takeshi Nishikawa; Toshiaki Tanaka; Tomomichi Kiyomatsu; Kazushige Kawai; Hiroaki Nozawa; Hironori Yamaguchi; Toshiaki Watanabe

2018-01-01

Summary: Colorectal cancer is seldom accompanied by venous tumor thrombosis, and little is known about the features of venous tumor thrombosis in colorectal cancer. However, some reports show that colorectal cancer patients can develop venous tumor thrombosis and warn clinicians not to overlook this complication. In this report, we perform a review of 43 previously reported cases and investigate the characteristics of colorectal cancer accompanied by venous tumor thrombosis. The histological ...

Developmental venous anomaly in the newborn brain

International Nuclear Information System (INIS)

Horsch, S.; Govaert, P.; Cowan, F.M.; Benders, M.J.N.L.; Groenendaal, F.; Vries, L.S. de; Lequin, M.H.; Saliou, G.

2014-01-01

Cerebral developmental venous anomaly (DVA) is considered a benign anatomical variant of parenchymal venous drainage; it is the most common vascular malformation seen in the adult brain. Despite its assumed congenital origin, little is known about DVA in the neonatal brain. We report here the first cohort study of 14 neonates with DVA. Fourteen infants (seven preterm) with DVA diagnosed neonatally using cranial ultrasound (cUS) and magnetic resonance imaging (MRI) from three tertiary neonatal units over 14 years are reviewed. DVA was first detected on cUS in 6 and on MRI in 8 of the 14 infants. The cUS appearances of DVA showed a focal fairly uniform area of increased echogenicity, often (86 %) adjacent to the lateral ventricle and located in the frontal lobe (58 %). Blood flow in the dilated collector vein detected by Doppler ultrasound (US) varied between cases (venous flow pattern in ten and arterialized in four). The appearance on conventional MRI was similar to findings in adults. Serial imaging showed a fairly constant appearance to the DVAs in some cases while others varied considerably regarding anatomical extent and flow velocity. This case series underlines that a neonatal diagnosis of DVA is possible with carefully performed cUS and MRI and that DVA tends to be an incidental finding with a diverse spectrum of imaging appearances. Serial imaging suggests that some DVAs undergo dynamic changes during the neonatal period and early infancy; this may contribute to why diagnosis is rare at this age. (orig.)

Developmental venous anomaly in the newborn brain

Energy Technology Data Exchange (ETDEWEB)

Horsch, S. [Erasmus MC-Sophia Children' s Hospital, Department of Neonatology, Rotterdam (Netherlands); Helios Klinikum Berlin-Buch, Department of Neonatology, Berlin (Germany); Govaert, P. [Erasmus MC-Sophia Children' s Hospital, Department of Neonatology, Rotterdam (Netherlands); Cowan, F.M. [Hammersmith Hospital, Department of Paediatrics, Imperial College Healthcare NHS Trust, London (United Kingdom); Benders, M.J.N.L.; Groenendaal, F.; Vries, L.S. de [University Medical Centre Utrecht, Wilhelmina Children' s Hospital, Department of Neonatology, Utrecht (Netherlands); Lequin, M.H. [Erasmus MC/Sophia Children' s Hospital, Department of Paediatric Radiology, Rotterdam (Netherlands); Saliou, G. [University Hospital, Department of Neuroradiology, Le Kremlin-Bicetre (France)

2014-07-15

Cerebral developmental venous anomaly (DVA) is considered a benign anatomical variant of parenchymal venous drainage; it is the most common vascular malformation seen in the adult brain. Despite its assumed congenital origin, little is known about DVA in the neonatal brain. We report here the first cohort study of 14 neonates with DVA. Fourteen infants (seven preterm) with DVA diagnosed neonatally using cranial ultrasound (cUS) and magnetic resonance imaging (MRI) from three tertiary neonatal units over 14 years are reviewed. DVA was first detected on cUS in 6 and on MRI in 8 of the 14 infants. The cUS appearances of DVA showed a focal fairly uniform area of increased echogenicity, often (86 %) adjacent to the lateral ventricle and located in the frontal lobe (58 %). Blood flow in the dilated collector vein detected by Doppler ultrasound (US) varied between cases (venous flow pattern in ten and arterialized in four). The appearance on conventional MRI was similar to findings in adults. Serial imaging showed a fairly constant appearance to the DVAs in some cases while others varied considerably regarding anatomical extent and flow velocity. This case series underlines that a neonatal diagnosis of DVA is possible with carefully performed cUS and MRI and that DVA tends to be an incidental finding with a diverse spectrum of imaging appearances. Serial imaging suggests that some DVAs undergo dynamic changes during the neonatal period and early infancy; this may contribute to why diagnosis is rare at this age. (orig.)

Estimation of gingival crevicular blood glucose level for the screening of diabetes mellitus: A simple yet reliable method.

Science.gov (United States)

Parihar, Sarita; Tripathi, Richik; Parihar, Ajit Vikram; Samadi, Fahad M; Chandra, Akhilesh; Bhavsar, Neeta

2016-01-01

This study was designed to assess the reliability of blood glucose level estimation in gingival crevicular blood(GCB) for screening diabetes mellitus. 70 patients were included in study. A randomized, double-blind clinical trial was performed. Among these, 39 patients were diabetic (including 4 patients who were diagnosed during the study) and rest 31 patients were non-diabetic. GCB obtained during routine periodontal examination was analyzed by glucometer to know blood glucose level. The same patient underwent for finger stick blood (FSB) glucose level estimation with glucometer and venous blood (VB) glucose level with standardized laboratory method as per American Diabetes Association Guidelines. 1 All the three blood glucose levels were compared. Periodontal parameters were also recorded including gingival index (GI) and probing pocket depth (PPD). A strong positive correlation ( r ) was observed between glucose levels of GCB with FSB and VB with the values of 0.986 and 0.972 in diabetic group and 0.820 and 0.721 in non-diabetic group. As well, the mean values of GI and PPD were more in diabetic group than non-diabetic group with the statistically significant difference ( p  blood glucose level as the values were closest to glucose levels estimated by VB. The technique is safe, easy to perform and non-invasive to the patient and can increase the frequency of diagnosing diabetes during routine periodontal therapy.

Effects of endurance training on blood pressure, blood pressure-regulating mechanisms, and cardiovascular risk factors.

Science.gov (United States)

Cornelissen, Véronique A; Fagard, Robert H

2005-10-01

Previous meta-analyses of randomized controlled trials on the effects of chronic dynamic aerobic endurance training on blood pressure reported on resting blood pressure only. Our aim was to perform a comprehensive meta-analysis including resting and ambulatory blood pressure, blood pressure-regulating mechanisms, and concomitant cardiovascular risk factors. Inclusion criteria of studies were: random allocation to intervention and control; endurance training as the sole intervention; inclusion of healthy sedentary normotensive or hypertensive adults; intervention duration of > or =4 weeks; availability of systolic or diastolic blood pressure; and publication in a peer-reviewed journal up to December 2003. The meta-analysis involved 72 trials, 105 study groups, and 3936 participants. After weighting for the number of trained participants and using a random-effects model, training induced significant net reductions of resting and daytime ambulatory blood pressure of, respectively, 3.0/2.4 mm Hg (Phypertensive study groups (-6.9/-4.9) than in the others (-1.9/-1.6; Pendurance training decreases blood pressure through a reduction of vascular resistance, in which the sympathetic nervous system and the renin-angiotensin system appear to be involved, and favorably affects concomitant cardiovascular risk factors.

Single-scan rest/stress imaging: validation in a porcine model with 18F-Flurpiridaz.

Science.gov (United States)

Guehl, Nicolas J; Normandin, Marc D; Wooten, Dustin W; Rozen, Guy; Sitek, Arkadiusk; Ruskin, Jeremy; Shoup, Timothy M; Ptaszek, Leon M; El Fakhri, Georges; Alpert, Nathaniel M

2017-08-01

18 F-labeled myocardial flow agents are becoming available for clinical application but the ∼2 hour half-life of 18 F complicates their clinical application for rest-stress measurements. The goal of this work is to evaluate in a pig model a single-scan method which provides quantitative rest-stress blood flow in less than 15 minutes. Single-scan rest-stress measurements were made using 18 F-Flurpiridaz. Nine scans were performed in healthy pigs and seven scans were performed in injured pigs. A two-injection, single-scan protocol was used in which an adenosine infusion was started 4 minutes after the first injection of 18 F-Flurpiridaz and followed either 3 or 6 minutes later by a second radiotracer injection. In two pigs, microsphere flow measurements were made at rest and during stress. Dynamic images were reoriented into the short axis view, and regions of interest (ROIs) for the 17 myocardial segments were defined in bull's eye fashion. PET data were fitted with MGH2, a kinetic model with time varying kinetic parameters, in which blood flow changes abruptly with the introduction of adenosine. Rest and stress myocardial blood flow (MBF) were estimated simultaneously. The first 12-14 minutes of rest-stress PET data were fitted in detail by the MGH2 model, yielding MBF measurement with a mean precision of 0.035 ml/min/cc. Mean myocardial blood flow across pigs was 0.61 ± 0.11 mL/min/cc at rest and 1.06 ± 0.19 mL/min/cc at stress in healthy pigs and 0.36 ± 0.20 mL/min/cc at rest and 0.62 ± 0.24 mL/min/cc at stress in the ischemic area. Good agreement was obtained with microsphere flow measurement (slope = 1.061 ± 0.017, intercept = 0.051 ± 0.017, mean difference 0.096 ± 0.18 ml/min/cc). Accurate rest and stress blood flow estimation can be obtained in less than 15 min of PET acquisition. The method is practical and easy to implement suggesting the possibility of clinical translation.

Optoacoustic technique for noninvasive monitoring of blood oxygenation: a feasibility study

Science.gov (United States)

Esenaliev, Rinat O.; Larina, Irina V.; Larin, Kirill V.; Deyo, Donald J.; Motamedi, Massoud; Prough, Donald S.

2002-08-01

Replacement of invasive monitoring of cerebral venous oxygenation with noninvasive techniques offers great promise in the management of life-threatening neurologic illnesses including traumatic brain injury. We developed and built an optoacoustic system to noninvasively monitor cerebral venous oxygenation; the system includes a nanosecond Nd:YAG laser and a specially designed optoacoustic probe. We tested the system in vitro in sheep blood with experimentally varied oxygenation. Our results demonstrated that (1) the amplitude and temporal profile of the optoacoustic waves increase with blood oxygenation in the range from 24% to 92%, (2) optoacoustic signals can be detected despite optical and acoustic attenuation by thick bone, and (3) the system is capable of real-time and continuous measurements. These results suggest that the optoacoustic technique is technically feasible for continuous, noninvasive monitoring of cerebral venous oxygenation.

Multiresolution analysis of pathological changes in cerebral venous dynamics in newborn mice with intracranial hemorrhage: adrenorelated vasorelaxation

International Nuclear Information System (INIS)

Pavlov, A N; Pavlova, O N; Tuchin, V V; Semyachkina-Glushkovskaya, O V; Zhang, Y; Bibikova, O A; Huang, Q; Zhu, D; Li, P; Luo, Q

2014-01-01

Intracranial hemorrhage (ICH) is the major problem of modern neonatal intensive care. Abnormalities of cerebral venous blood flow (CVBF) can play a crucial role in the development of ICH in infants. The mechanisms underlying these pathological processes remain unclear; however it has been established that the activation of the adrenorelated vasorelaxation can be an important reason. Aiming to reach a better understanding of how the adrenodependent relaxation of cerebral veins contributes to the development of ICH in newborns, we study here the effects of pharmacological stimulation of adrenorelated dilation of the sagittal sinus by isoproterenol on the cerebral venous hemodynamics. Our study is performed in newborn mice at different stages of ICH using the laser speckle contrast imaging and wavelet analysis of the vascular dynamics of CVBF. We show that the dilation of the sagittal sinus with the decreased velocity of blood flow presides to the stress-induced ICH in newborn mice. These morphofunctional vascular changes are accompanied by an increased variance of the wavelet-coefficients in the areas of endothelial and non-endothelial (K ATP -channels activity of vascular muscle) sympathetic components of the CVBF variability. Changes in the cerebral venous hemodynamics at the latent stage of ICH are associated with a high responsiveness of the sagittal sinus to isoproterenol quantifying by wavelet-coefficients related to a very slow region of the frequency domain. The obtained results certify that a high activation of the adrenergic-related vasodilatory responses to severe stress in newborn mice can be one of the important mechanisms underlying the development of ICH. Thus, the venous insufficiency with the decreased blood outflow from the brain associated with changes in the endothelial and the sympathetic components of CVBF-variability can be treated as prognostic criteria for the risk of ICH during the first days after birth. (paper)

Significance of venous anastomosis in fingertip replantation.

Science.gov (United States)

Hattori, Yasunori; Doi, Kazuteru; Ikeda, Keisuke; Abe, Yukio; Dhawan, Vikas

2003-03-01

Adequate venous outflow is the most important factor for successful fingertip replantation. The authors have attempted venous anastomosis in all cases of fingertip replantation to overcome postoperative congestion. In this article, the significance of venous repair for fingertip replantation is described from the authors' results of 64 complete fingertip amputations in 55 consecutive patients, which were replanted from January of 1996 to June of 2001. The overall survival rate was 86 percent. Of the 44 replantations in zone I, 37 survived, and the success rate was 84 percent. Of the 20 replantations in zone II, 18 survived, and the success rate was 90 percent. Venous anastomosis was attempted in all cases, but it was possible in 39 zone I and in all zone II replantations. For arterial repair, vein grafts were necessary in 17 of the 44 zone I and in one of the 20 zone II replantations; for venous repair, they were necessary in six zone I replantations and one zone II replantation. Postoperative vascular complications occurred in 15 replantations. There were five cases of arterial thrombosis and 10 cases of venous congestion. Venous congestion occurred in nine zone I and one zone II replantations. In five of these 10 replantations, venous anastomosis was not possible. In another five replantations, venous outflow was established at the time of surgery, but occlusion occurred subsequently. Except for the five failures resulting from arterial thrombosis, successful venous repair was possible in 49 of 59 replantations (83 percent). Despite the demand for skillful microsurgical technique and longer operation time, the authors' results using venous anastomosis in successful fingertip replantations are encouraging. By performing venous anastomosis, external bleeding can be avoided and a higher survival rate can be achieved. Venous anastomosis for fingertip replantation is a reliable and worthwhile procedure.

Chronic venous leg ulcers – role of topical zinc

Directory of Open Access Journals (Sweden)

Maher SF

2015-06-01

Full Text Available Sara F Maher Physical Therapy Program, Department of Healthcare Sciences, Wayne State University, Detroit, MI, USA Abstract: Topical zinc has been used in the treatment of wounds for over 3,000 years, and is reported to have antiseptic, astringent, anti-inflammatory, antimicrobial, and wound healing properties. Fourteen studies were identified and reviewed, to assess the efficacy of this treatment modality as either a bandage or skin protectant in the treatment of venous ulcers. The authors of three studies reported improved healing time or success rate in wounds treated with zinc-based products. However, the authors of one study attributed the faster healing rate mainly to the extra compression (that improved venous blood return, delivered by the non-elastic paste bandage, and not by the zinc oxide alone. The quality of evidence is fair, as 50% of the studies were conducted prior to 2000 and 50% of the studies utilized fewer than 45 patients randomized to two or more groups. Other treatments have been reported to be more cost-effective than zinc, including hydrocolloids, four-layer compression systems, and CircAid Thera-boots. Finally, zinc was reported to be less comfortable, less easy to use, and caused increased pain, in comparison to other products on the market. This literature review, therefore, demonstrated that current evidence is insufficient to determine the effectiveness of zinc-based products in the treatment of venous wounds. Future research is needed focusing on larger, high-quality trials with an emphasis on quality of life issues and cost-effectiveness of treatment. Keywords: chronic wounds, leg ulcers, venous insufficiency, topical zinc

Fanconi anaemia with bilateral diffuse pulmonary arterio venous fistulae: a case report

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Samarakoon Lasitha

2012-03-01

Full Text Available Abstract Background We report a patient with cytogenetically confirmed Fanconi anaemia with associated diffuse bilateral pulmonary arterio-venous fistulae. This is only the second reported case of diffuse pulmonary arterio-venous fistulae with Fanconi anaemia. Case Presentation A 16 year old Sri Lankan boy, with a cytogenetically confirmed Fanconi anaemia was admitted to University Medical Unit, National Hospital of Sri Lanka for further assessment and treatment. Both central and peripheral cyanosis plus clubbing were noted on examination. The peripheral saturation was persistently low on room air and did not improve with supplementary Oxygen. Contrast echocardiography failed to demonstrate an intra cardiac shunt but showed early crossover of contrast, suggesting the possibility of pulmonary arterio-venous fistulae. Computed tomography pulmonary angiogram was inconclusive. Subsequent right heart catheterisation revealed bilateral diffuse arterio-venous fistulae not amenable for device closure or surgical intervention. Conclusion To our knowledge, this is the second reported patient with diffuse pulmonary arterio-venous fistulae associated with Fanconi anaemia. We report this case to create awareness among clinicians regarding this elusive association. We recommend screening patients with Fanconi anaemia using contrast echocardiography at the time of assessment with transthoracic echocardiogram. Though universal screening may be impossible given the cost constraints, such screening should at least be performed in patients with clinical evidence of desaturation or when a therapeutic option such as haematopoietic stem cell transplantation is considered. Treatment of pulmonary arteriovenous fistulae would improve patient outcome as desaturation by shunting worsens the anaemic symptoms by reducing the oxygen carrying capacity of blood.

Effects of head-down-tilt bed rest on cerebral hemodynamics during orthostatic stress

Science.gov (United States)

Zhang, R.; Zuckerman, J. H.; Pawelczyk, J. A.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

1997-01-01

Our aim was to determine whether the adaptation to simulated microgravity (microG) impairs regulation of cerebral blood flow (CBF) during orthostatic stress and contributes to orthostatic intolerance. Twelve healthy subjects (aged 24 +/- 5 yr) underwent 2 wk of -6 degrees head-down-tilt (HDT) bed rest to simulate hemodynamic changes that occur when humans are exposed to microG. CBF velocity in the middle cerebral artery (transcranial Doppler), blood pressure, cardiac output (acetylene rebreathing), and forearm blood flow were measured at each level of a ramped protocol of lower body negative pressure (LBNP; -15, -30, and -40 mmHg x 5 min, -50 mmHg x 3 min, then -10 mmHg every 3 min to presyncope) before and after bed rest. Orthostatic tolerance was assessed by using the cumulative stress index (CSI; mmHg x minutes) for the LBNP protocol. After bed rest, each individual's orthostatic tolerance was reduced, with the group CSI decreased by 24% associated with greater decreases in cardiac output and greater increases in systemic vascular resistance at each level of LBNP. Before bed rest, mean CBF velocity decreased by 14, 10, and 45% at -40 mmHg, -50 mmHg, and maximal LBNP, respectively. After bed rest, mean velocity decreased by 16% at -30 mmHg and by 21, 35, and 39% at -40 mmHg, -50 mmHg, and maximal LBNP, respectively. Compared with pre-bed rest, post-bed-rest mean velocity was less by 11, 10, and 21% at -30, -40, and -50 mmHg, respectively. However, there was no significant difference at maximal LBNP. We conclude that cerebral autoregulation during orthostatic stress is impaired by adaptation to simulated microG as evidenced by an earlier and greater fall in CBF velocity during LBNP. We speculate that impairment of cerebral autoregulation may contribute to the reduced orthostatic tolerance after bed rest.

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

Science.gov (United States)

Ugas, Mohamed Ali; Cho, Hyongyu; Trilling, Gregory M; Tahir, Zainab; Raja, Humaera Farrukh; Ramadan, Sami; Jerjes, Waseem; Giannoudis, Peter V

2012-09-04

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.

Intrinsic regulation of blood flow in adipose tissue

DEFF Research Database (Denmark)

Henriksen, O; Nielsen, Steen Levin; Paaske, W

1976-01-01

Previous studies on intact human subcutaneous tissue have shown, that blood flow remains constant during minor changes in perfusion pressure. This so-called autoregulatory response has not been demonstrable in isolated preparations of adipose tissue. In the present study on isolated, denervated...... subcutaneous tissue in female rabbits only 2 of 12 expts. revealed an autoregulatory response during reduction in arterial perfusion pressure. Effluent blood flow from the tissue in the control state was 15.5 ml/100 g-min (S.D. 6.4, n = 12) corresponding to slight vasodilatation of the exposed tissue...... vasoconstriction with pronounced flow reduction. These two reactions may be important for local regulation of blood flow in subcutaneous tissue during orthostatic changes in arterial and venous pressure. It is concluded that the response in adipose tissue to changes in arterial pressure (autoregulation), venous...

D-Dimer and prothrombin fragment 1 + 2 in urine and plasma in patients with clinically suspected venous thromboembolism.

Science.gov (United States)

Wexels, Fredrik; Seljeflot, Ingebjørg; Pripp, Are H; Dahl, Ola E

2016-06-01

Increased levels of urine prothrombin fragment 1 + 2 was recently reported to be associated with imaging-verified venous thromboembolism. In this study we evaluated the relationship between plasma D-dimer and plasma and urine prothrombin fragment 1 + 2 in patients with suspected venous thromboembolism. Urine and blood samples were collected from patients with suspected pulmonary embolism or deep vein thrombosis. The samples were analysed with commercially available ELISA kits. The diagnosis of venous thromboembolism was verified with contrast-enhanced computer tomography of the pulmonary arteries or lower extremity deep vein compression ultrasound and venography as appropriate. Venous thromboembolism was diagnosed in 150 of 720 patients. Significantly higher levels of plasma D-dimer and prothrombin fragment 1 + 2 in plasma and urine were found in those with imaging-confirmed venous thromboembolism versus those without (P fragment 1 + 2 in plasma. Further development of ELISA analyses for urine testing of prothrombin fragment 1 + 2 may improve its diagnostic accuracy.

Venous abnormalities demonstrated by computed tomography

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, T; Tsukune, Y; Ashida, H; Tokuda, M; Oyama, Y [St. Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

1980-05-01

CT is capable of demonstrating various venous changes. However, little have been described on this subject in the literature. Examples of various venous abnormalities such as obstructed jugular vein, superior and inferior vena cava (IVC), tumor invasion of IVC and renal vein and venous changes in portal hypertension were presented. It was stressed that noninvasive CT is a good tool in diagnosis of some of venous changes and may be able to eliminate angiography in such cases.

Mean Platelet Volume in Patients with Chronic Venous Insufficiency

Directory of Open Access Journals (Sweden)

Mehmet Akif Sarıca

2016-03-01

Full Text Available Objective: the mean platelet volume (MPV is a good indicator of platelet activity; it is reported to increase in diseases associated with inflammatory processes and in vascular diseases. This study investigated the importance of mean platelet volume in patients with chronic venous insufficiency (CVI and whether the MPV was likely to be a predictor of the CVI. Methods: 117 patients who were diagnosed as CVI by colored Doppler Ultrasound (CDU method and 49 healthy volunteers (forming the control group were en­rolled to this study, which was planned retrospectively. The patients’ blood count values taken within one month before and after the CDU evaluation were recorded by the hospital information system. The complete blood count, routine biochemical tests and thyroid function tests of the patients diagnosed with CVI were compared to the control group. Results: Significant differences were not detected be­tween the patients and the control group in terms of the levels of creatinine, aspartate aminotransferase, total cholesterol, LDL cholesterol, HDL cholesterol, triglycer­ides, erythrocyte, sedimentation speed, leukocyte, hae­moglobin and thrombocyte (p>0.05. The thyroid stimulat­ing hormone and the MPV levels were significantly lower in the control group (p<0.05. Conclusion: MPV levels as an easy, cheap and practi­cal data extracted from complete blood count, were found higher in patients diagnosed with CVI compared to the control group. This may be originated from endothelium changes as an answer to venous hypertension and dila­tation in CVI. MPV can be used as a follow-up marker in CVI patients. J Clin Exp Invest 2016; 7 (1: 73-77

Venous Access Ports: Indications, Implantation Technique, Follow-Up, and Complications

Energy Technology Data Exchange (ETDEWEB)

Walser, Eric M., E-mail: walser.eric@mayo.edu [Mayo Clinic, Department of Radiology (United States)

2012-08-15

The subcutaneous venous access device (SVAD or 'port') is a critical component in the care of patients with chronic disease. The modern SVAD provides reliable access for blood withdrawal and medication administration with minimal disruption to a patient's lifestyle. Because of improved materials and catheter technology, today's ports are lighter and stronger and capable of high-pressure injections of contrast for cross-sectional imaging. The majority of SVAD placement occurs in interventional radiology departments due to their ability to provide this service at lower costs, lower, complication rates, and greater volumes. Port-insertion techniques vary depending on the operator, but all consist of catheter placement in the central venous circulation followed by subcutaneous pocket creation and port attachment to the catheter with fixation and closure of the pocket. Venous access challenges occasionally occur in patients with central vein occlusions, necessitating catheterization of collateral veins or port placement in alternate locations. Complications of SVADs include those associated with the procedure as well as short- (<30 days) and long-term problems. Procedural and early complications are quite rare due to the near-universal use of real-time ultrasound guidance for vein puncture, but they can include hematoma, catheter malposition, arrhythmias, and pneumothorax. Late problems include both thrombotic complications (native venous or port-catheter thrombosis) and infections (tunnel or pocket infections or catheter-associated bloodstream infections). Most guidelines suggest that 0.3 infections/1000 catheter days is an appropriate upper threshold for the insertion of SVADs.

Current status of malaria parasite among blood donors in Port ...

African Journals Online (AJOL)

This study was carried out to determine the prevalence of malaria parasite among blood donors at the Police Clinic Port Harcourt, Rivers State, Nigeria. The standard parasitological techniques using both thick and thin blood films from the donors for the detection of malaria parasite was followed. Venous blood was ...

Altered Venous Function during Long-Duration Spaceflights

Directory of Open Access Journals (Sweden)

Jacques-Olivier Fortrat

2017-09-01

Full Text Available Aims: Venous adaptation to microgravity, associated with cardiovascular deconditioning, may contribute to orthostatic intolerance following spaceflight. The aim of this study was to analyze the main parameters of venous hemodynamics with long-duration spaceflight.Methods: Venous plethysmography was performed on 24 cosmonauts before, during, and after spaceflights aboard the International Space Station. Venous plethysmography assessed venous filling and emptying functions as well as microvascular filtration, in response to different levels of venous occlusion pressure. Calf volume was assessed using calf circumference measurements.Results: Calf volume decreased during spaceflight from 2.3 ± 0.3 to 1.7 ± 0.2 L (p < 0.001, and recovered after it (2.3 ± 0.3 L. Venous compliance, determined as the relationship between occlusion pressure and the change in venous volume, increased during spaceflight from 0.090 ± 0.005 to 0.120 ± 0.007 (p < 0.01 and recovered 8 days after landing (0.071 ± 0.005, arbitrary units. The index of venous emptying rate decreased during spaceflight from −0.004 ± 0.022 to −0.212 ± 0.033 (p < 0.001, arbitrary units. The index of vascular microfiltration increased during spaceflight from 6.1 ± 1.8 to 10.6 ± 7.9 (p < 0.05, arbitrary units.Conclusion: This study demonstrated that overall venous function is changed during spaceflight. In future, venous function should be considered when developing countermeasures to prevent cardiovascular deconditioning and orthostatic intolerance with long-duration spaceflight.

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

Quantitative assessment of cerebral blood flow employing the Rutland method using N-isopropyl-(123I)-p-iodoamphetamine

International Nuclear Information System (INIS)

Aoki, Shigeru; Kitano, Tokio.

1992-01-01

The purpose of this study is to evaluate clinical usefulness as the quantitative assessment of the cerebral blood flow by venous sampling supersede arterial sampling using N-isopropyl-( 123 I)-p-iodoamphetamine (IMP) and single-photon emission computed tomography. The method employed Ono's report using the Rutland method. The mean value of total cerebral blood flow by arterial sampling was 388.0±79.4 (standard deviation) ml/min, and that by venous sampling was 448.5±110.3 ml/min. The value of temporal lobe, including basal ganglia where there was no evidence of neurological, electroencephalographic, and other imaging findings was 44.0±3.8 ml/100g/min using arterial sampling and 49.7±6.0 ml/100g/min using venous sampling. (n=22, mean age 57.6) The value of cases with poor peripheral circulation varied a great deal between the arterial and venous samplings. There was a good correlation between arterial and venous samplings in 76 patients without poor peripheral circulation. In conclusion, this method is available for noninvasive quantitative assessment of the cerebral blood flow in patients without poor peripheral circulation. (author)

Blood flow in the forearm in patients with Rheumatoid arthritis and healthy subjects under local thermotherapy

Directory of Open Access Journals (Sweden)

C. Mucha

2002-02-01

Full Text Available Objectives: Muscle blood flow in the forearm of patients with rheuma-toid arthritis and healthy volunteers following treatment with temperature increasingarm baths, mudpacks and short- or decimeter-wave diathermy was studied in thisinvestigation. The aim of the study was to find out the difference of reactive hyperemia between the different temperature methods as well as the influence on theconsensual reaction. Subjects: Eighty patients with rheumatoid arthritis, stage 3 according toSteinbrocker, as well as 80 healthy human subjects had been assigned numerically in the four therapy- and controlgroups. Patients with diseases influencing the peripheral blood flow were excluded. Design: Blood flow was measured by venous occlusion plethysmography in both forearms with the subjects lyingsupine. The application of the local heat therapies had been excluded on the left forearm. The forearm blood flow wasmonitored before heat therapy, directly after as well as in two further 10 minutes intervals. An analysis of variancewas used to determine the influence on blood flow of the response to the heat therapies in patients with rheumatoidarthritis and healthy subjects.Results: Under homogeneous starting conditions and a statistically uniformed high blood flow in rest the reactive values of blood flow on the left-hand side of application and the right consensual side showed high significant differencesbetween all methods of therapy. Differences between the patients and the healthy subjects only showed tendencies withpartially lower reactions, concerning the patients with rheumatoid arthritis. All methods of heat therapy caused a statistically provable consensual reaction that turned out smaller after diathermic methods. Here the post therapeuticreaction of the blood flow on the side of application was also lower or rather shorter. Conclusion: Greater differences of the blood flow in rest between the patients with rheumatoid arthritis and healthysubjects

Visualization of portal venous system by single photon emission CT

Energy Technology Data Exchange (ETDEWEB)

Kashiwagi, T; Ikawa, T; Azuma, M; Matsuda, H; Yoshioka, H; Mitsutani, N; Koizumi, T

1987-03-01

Single photon emission CT (SPECT) was performed for the intra-abdominal blood pool with /sup 99m/Tc autologous red blood cells (RBC) in 15 patients with liver cirrhosis. Twenty mCi of /sup 99m/Tc-RBC labeled by in vivo technique were administered intravenously and tomographic imaging of the intra-abdominal vascular blood pool was performed as follows. For each subject, 64 views were obtained over 360 deg of elliptic rotation at 30 seconds per view using a high resolution low energy parallel-hole collimator. Portal vein and portosystemic collaterals were clearly observed in coronal images. In 12 of 15 patients, portal vein was delineated. Portosystemic collaterals such as coronary vein, splenorenal shunt and umbilical vein were also shown in 12 patients. These images were consistent with images obtained by scintiphotosplenoportography or arterial portography. Therefore, it is considered that SPECT study for the intra-abdominal blood pool is clinically very useful for the diagnosis of abnormality of portal venous system in portal hypertension.

Combined oral contraceptives: venous thrombosis.

Science.gov (United States)

de Bastos, Marcos; Stegeman, Bernardine H; Rosendaal, Frits R; Van Hylckama Vlieg, Astrid; Helmerhorst, Frans M; Stijnen, Theo; Dekkers, Olaf M

2014-03-03

Combined oral contraceptive (COC) use has been associated with venous thrombosis (VT) (i.e., deep venous thrombosis and pulmonary embolism). The VT risk has been evaluated for many estrogen doses and progestagen types contained in COC but no comprehensive comparison involving commonly used COC is available. To provide a comprehensive overview of the risk of venous thrombosis in women using different combined oral contraceptives. Electronic databases (Pubmed, Embase, Web of Science, Cochrane, CINAHL, Academic Search Premier and ScienceDirect) were searched in 22 April 2013 for eligible studies, without language restrictions. We selected studies including healthy women taking COC with VT as outcome. The primary outcome of interest was a fatal or non-fatal first event of venous thrombosis with the main focus on deep venous thrombosis or pulmonary embolism. Publications with at least 10 events in total were eligible. The network meta-analysis was performed using an extension of frequentist random effects models for mixed multiple treatment comparisons. Unadjusted relative risks with 95% confidence intervals were reported.Two independent reviewers extracted data from selected studies. 3110 publications were retrieved through a search strategy; 25 publications reporting on 26 studies were included. Incidence of venous thrombosis in non-users from two included cohorts was 0.19 and 0.37 per 1 000 person years, in line with previously reported incidences of 0,16 per 1 000 person years. Use of combined oral contraceptives increased the risk of venous thrombosis compared with non-use (relative risk 3.5, 95% confidence interval 2.9 to 4.3). The relative risk of venous thrombosis for combined oral contraceptives with 30-35 μg ethinylestradiol and gestodene, desogestrel, cyproterone acetate, or drospirenone were similar and about 50-80% higher than for combined oral contraceptives with levonorgestrel. A dose related effect of ethinylestradiol was observed for gestodene

Biochemical characterization of blood plasma of coronary artery ...

Indian Academy of Sciences (India)

This study aimed to investigate the biochemical profile of blood plasma of patients with coronary artery disease (CAD) and angiographically normal subjects (controls) to determine biomarkers for their differentiation. In this double blind study, 5 mL venous blood was drawn before angiography from CAD patients (n=60) and ...

Venous chest anatomy: clinical implications

International Nuclear Information System (INIS)

Chasen, M.H.; Charnsangavej, C.

1998-01-01

This article provides a practical approach to the clinical implications and importance of understanding the collateral venous anatomy of the thorax. Routine radiography, conventional venography, computed tomography (CT), and magnetic resonance (MR) imaging studies provide correlative anatomic models for the demonstration of how interconnecting collateral vascular networks within the thorax maintain venous stability at all times. Five major systems comprise the collateral venous network of the thorax ( Fig. 1 ). These include the paravertebral, azygos-hemiazygos, internal mammary, lateral thoracic, and anterior jugular venous systems (AJVS). The five systems are presented in the following sequence: (a) a brief introduction to the importance of catheter position and malposition in understanding access to the thoracic venous system, (b) the anatomy of the azygos-hemiazygos systems and their relationship with the paravertebral plexus, (c) the importance of the AJVS, (d) 'loop' concepts interconnecting the internal mammary and azygos-hemiazygos systems by means of the lateral thoracic and intercostal veins, and (e) the interconnecting venous networks on the thoracic side of the thoracoabdominal junction. Certain aspects of the venous anatomy of the thorax will not be discussed in this chapter and include (a) the intra-abdominal anastomoses between the superior and inferior vena cavae (IVC) via the internal mammary, lateral thoracic, and azygos-hemiazygos systems (beyond the scope of this article), (b) potential collateral vessels involving vertebral, parascapular, thyroidal, thymic, and other smaller veins that might anastomose with the major systems, and (c) anatomic variants and pitfalls that may mimic pathologic conditions (space limitations). (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Sonographic detection of portal venous gas

International Nuclear Information System (INIS)

Lee, Wang Yul; Lee, S. K.; Cho, O. K.

1989-01-01

Portal venous gas suggests underlying bowel disease such as strangulating intestinal obstruction and its demonstration carries with it an important implications with respect to patient management. Radiography has been the gold standard for the detection of portal venous gas. We have experienced two cases of portal venous gas diagnosed by ultrasound. Sonographic findings were floating echoes in the main portal vein and highly echogenic linear or patchy echoes within the hepatic parenchyma. Simple abdominal films of those cases failed to demonstrate gas in the portal venous system