Search results for "Blood volume"

Higher vascularity at infiltrated peripheral edema differentiates proneural glioblastoma subtype

2020

[EN] Background and purpose Genetic classifications are crucial for understanding the heterogeneity of glioblastoma. Recently, perfusion MRI techniques have demonstrated associations molecular alterations. In this work, we investigated whether perfusion markers within infiltrated peripheral edema were associated with proneural, mesenchymal, classical and neural subtypes. Materials and methods ONCOhabitats open web services were used to obtain the cerebral blood volume at the infiltrated peripheral edema for MRI studies of 50 glioblastoma patients from The Cancer Imaging Archive: TCGA-GBM. ANOVA and Kruskal-Wallis tests were carried out in order to assess the association between vascular fea…

Insulin resistance syndrome and autonomically mediated physiological responses to experimentally induced mental stress in adolescent boys

1996

We investigated the relationship between hemodynamic and other autonomically mediated responses to experimentally induced mental stress and the parameters of the insulin resistance syndrome (IRS) in 48 healthy adolescent boys. Mental stress was induced with mental arithmetic and the Stroop Color-Word Test. Heart rate (HR), finger blood volume (FBV), and skin conductance level (SCL) were recorded continuously during task performance. IRS parameters measured were serum insulin, high-density lipoprotein (HDL) cholesterol, serum triglyceride (TG), systolic blood pressure (SBP), subscapular skinfold (SSF), and subscapular to triceps skinfold ratio (STR). The results indicated that a high level a…

Blood Infusion and the Risk of Haemorrhage in Patients Undergoing Cardiac Surgery with Extracorporeal Circulation.

2016

Purpose: Patients undergoing cardiac surgery with extracorporeal circulation (ECC) frequently present haemorrhages as a complication associated with high morbidity and mortality. One of the factors that influences this risk is the volume of blood infused during surgery. The objective of this study was to determine the optimal volume of autologous blood that can be processed during cardiac surgery with ECC. We also determined the number of salvaged red blood cells to be reinfused into the patient in order to minimize the risk of haemorrhage in the postoperative period. Methods: This was an observational retrospective cross-sectional study performed in 162 ECC cardiac surgery patients. Data r…

Lethal Anaphylactic Reaction to Intravenous Gelatin in the Course of Surgery

2016

Plasma volume expanders (PVEs) are widely used to increase circulating blood volume. Gelatins used as PVEs are heterogeneous mixtures of polypeptides, usually prepared by hydrolysis of bovine collagen containing large amounts of proline and hydroxyproline residues. It has been shown that gelatins can cause anaphylactic reactions. We describe the case of a 73-year-old man who during surgery for intestinal obstruction presented a lethal anaphylactic reaction after the administration of a PVE containing gelatin lysate. The reaction occurred 10 minutes after the start of plasma expander infusion. Then, patient became comatose, and he died without awakening after 76 days. Necroptic aspects and h…

Diagnostic performance of whole brain volume perfusion CT in intra-axial brain tumors: preoperative classification accuracy and histopathologic corre…

2012

Abstract Background To evaluate the preoperative diagnostic power and classification accuracy of perfusion parameters derived from whole brain volume perfusion CT (VPCT) in patients with cerebral tumors. Methods Sixty-three patients (31 male, 32 female; mean age 55.6 ± 13.9 years), with MRI findings suspected of cerebral lesions, underwent VPCT. Two readers independently evaluated VPCT data. Volumes of interest (VOIs) were marked circumscript around the tumor according to maximum intensity projection volumes, and then mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability Ktrans perfusion datasets. A second VOI was placed in the contra lateral cortex, as cont…

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

2015

Background A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Methods Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour w…

Blood circulation of long bones in trained growing rats and mice

1975

The effect of physical training on the blood circulation of long bones was studied in growing rats and mice of NMRI-strain. The animals to be trained and their controls were about 2 weeks old at the beginning of the training. The training took place on a 5 degree inclined treadmill 5 days a week for 3 weeks in experiment I and 7 weeks in experiments II and III. The duration of the daily exercise was progressively increased over 3 weeks. The final exercise bouts were 80 min for moderate and 180 min for intensive training programs. The circulating red cell volume (ml/100 g bone) of the humeral, femoral and tibial bones of the trained animals was lower compared to the controls in all three exp…

The effects of skin and core tissue cooling on oxygenation of the vastus lateralis muscle during walking and running

2016

Skin and core tissue cooling modulates skeletal muscle oxygenation at rest. Whether tissue cooling also influences the skeletal muscle deoxygenation response during exercise is unclear. We evaluated the effects of skin and core tissue cooling on skeletal muscle blood volume and deoxygenation during sustained walking and running. Eleven male participants walked or ran six times on a treadmill for 60 min in ambient temperatures of 22°C (Neutral), 0°C for skin cooling (Cold 1), and at 0°C following a core and skin cooling protocol (Cold 2). Difference between oxy/deoxygenated haemoglobin ([diffHb]: deoxygenation index) and total haemoglobin content ([tHb]: total blood volume) in the vastus lat…

Micro-circulation of skin blood: optical monitoring by advanced photoplethysmography techniques

2003

Blood micro-circulation in upper skin layers has been studied experimentally in real time by advanced two-channel photoplethysmography (PPG) techniques. The blood volume changes caused by micro-vessel expansion and dilution during the cardiac cycles have been detected by infrared optical contact sensors. A newly developed portable monitoring device comprising a lap-top computer was used for accumulation and processing of the bio-signals. Shapes of the PPG signals detected at different sites of the body were compared with these obtained by computer modeling.

2006

Introduction The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using highfrequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. Methods With institutional review board approval, the hemodynamics, blood gas analysis, TPP, and pulmonary shunt fraction were obtained in six anesthetized pigs before and after saline lung lavage. Measurements were acquired during pressure-controlled ventilation (PCV) prior to and after lung damage, and during a LVOP with HFOV. The LVOP comprised a recruitment maneuver with a continuous distending pressure (CDP) of 45 mbar …