Search results for "Circulation"
showing 10 items of 1137 documents
Effect of acute systemic hypoxia on human cutaneous microcirculation and endothelial, sympathetic and myogenic activity
2015
The regulation of cutaneous vascular tone impacts vascular vasomotion and blood volume distribution as a challenge to hypoxia, but the regulatory mechanisms yet remain poorly understood. A skin has a very compliant circulation, an increase in skin blood flow results in large peripheral displacement of blood volume, which could be controlled by local and systemic regulatory factors. The aim of this study was to determine the acute systemic hypoxia influence on blood flow in skin, local regulatory mechanism fluctuations and changes of systemic hemodynamic parameters. Healthy subjects (n=11; 24.9±3.7years old) participated in this study and procedures were performed in siting position. After 2…
Retinal vessel analysis and heart rate variability
2014
Heart rate variability (HRV) is used to index the vegetative nervous system and is linked with cardiovascular and nervous diseases [1]. Funduscopic assessment of the retinal vasculature can be utilized to evaluate the health status of microcirculation and to assess the predisposition of major vascular diseases [2]. The purpose of this study was, for the first time, to examine the influence of HRV on microcirculation as an early marker of cardiovascular alteration. The study population was comprised of apparently healthy employees of a high-tech company in Germany. The participants spanned the entire age of the work force (18–65 years) and all levels of socioeconomic status. A total of 292 s…
Changes in cerebellar activation pattern during two successive sequences of saccades
2002
The changes in the cerebellar activation pattern of two successive fMRI scanning runs were determined for visually guided to‐and‐fro saccades in 12 healthy volunteers familiar with the study paradigm. Group and single subject‐analyses revealed a constant activation of the paramedian cerebellar vermis (uvula, tonsils, tuber, folium/declive), which reflects constant ocular motor activity in both runs. A significant decrease in activation of the cerebellar hemispheres found in the second run is best explained by either a decrease in attention or the effects of motor optimization and learning. The significant, systematic changes of the cerebellar activation pattern in two successive runs were n…
Human cerebral microcirculation and oxygen saturation during propofol-induced reduction of bispectral index †
2011
† This study investigates the effects of propofol-induced changes in bispectral index (BIS) on cerebral microcirculation and oxygenation during craniotomies. † In 2 mm cerebral depth, an increase in propofol dosage resulted in increased oxygen saturation (srvO2 )w ithout reduction of capillary venous blood flow (rvCBF). † Difference in oxygen content (avDO2) and approximated cerebralmetabolicrateofoxygen (aCMRO2) decreased with an increase in propofol dosage in 2 mm cerebral depth. † Alterations in BIS showed no effect on rvCBF, srvO2 ,a nd haemoglobin amount (rvHb) or on avDO2 or aCMRO2 in 8 mm cerebral depth. † These findings suggest that the CBF/CMRO2 ratio is altered by propofol in a re…
Sulodexide and the microcirculatory component in microphlebopathies.
1992
A double-blind, placebo-controlled study was carried out in 36 patients, aged 30 to 50 years, to evaluate the effectiveness of oral sulodexide in the treatment of chronic venous insufficiency due to idiopathic varices. Patients were allocated at random to receive either oral sulodexide as 2 capsules (each containing 250 lipoproteinolipase releasing units) twice daily or 2 identical placebo capsules twice daily over a period of 45 days. Using strain gauge plethysmographic data, assessments were made of the microcirculatory effects of treatment by calculating the coefficient of capillary filtration from measurements made on both legs of each patient on entry and after 30 and 45 days of treatm…
Central activation by histamine-induced itch: analogies to pain processing: a correlational analysis of O-15 H2O positron emission tomography studies
2001
The aim of this study was to identify the functional cerebral network involved in the central processing of itch and to detect analogies and differences to previously identified cerebral activation patterns triggered by painful noxious stimuli. Repeated positron emission tomography regional cerebral blood flow (rCBF) measurements using O15-labeled water were performed in six healthy right-handed male subjects (mean age 32 +/- 2 years). Each subject underwent 12 sequential rCBF measurements. In all subjects a standardized skin prick test was performed on the right forearm 2 min before each rCBF measurement. For activation, histamine was applied in nine tests in logarithmically increasing con…
Effects of grip and push forces on the acute response of the hand-arm system under vibrating conditions
1993
The purpose of the occupational medicine component of a joint research project was to study the effects of grip and push forces on the acute reaction of the hand-arm system under vibrating conditions. Several series of experiments were carried out by means of a vibration simulator in a laboratory environment in order to study biodynamic vibration behaviour, muscle response, skin temperature, shifts of the vibration perception threshold and the intensity of subjective vibration perception; in addition, field tests with hammer drills were conducted. On the whole, the findings obtained suggest that the coupling of the hand with the handle involved in using vibrating tools has a considerable im…
Transitional hemodynamics in infants of diabetic mothers by targeted neonatal echocardiography, electrocardiography and peripheral flow study
2017
Objective: Metabolic alterations of intrauterine environment in diabetes mellitus (DM) lead to fetal cardiac dysfunctions that can persist after birth. The aim of the study was to assess the cardiovascular adaptation in infants born to diabetic mothers (IDM) with different degrees of glycometabolic control, in relation to revised guidelines for diagnosis of DM and quality improvements in neonatal care. Materials and methods: An observational case-control study was conducted on IDM with gestational, type 1 and type 2âDM. Relevant maternal and neonatal anamnestic, clinical and laboratory data were analyzed. Electrocardiographic and echocardiographic analyses, including structural and systo-…
Effects of Fractionated Plasma Separation and Adsorption on Survival in Patients With Acute-on-Chronic Liver Failure
2012
BACKGROUND & AIMS: Fractionated plasma separation and adsorption (FPSA) is an extracorporeal procedure that supports liver function by removing endogenous toxins that cause complications from acute-on-chronic liver failure (AOCLF). We performed a randomized trial to investigate survival of patients with AOCLF treated with FPSA. METHODS: Patients with AOCLF were randomly assigned to groups given a combination of FPSA and standard medical therapy (SMT) (FPSA group, n = 77) or only SMT (SMT group, n = 68). The Prometheus liver support system was used to provide 8 to 11 rounds of FPSA (minimum of 4 hours each) for 3 weeks. Primary end points were survival probabilities at days 28 and 90, irresp…
In vivo evaluation of periodontal microcirculatory changes associated with endodontic treatment.
2014
The purpose of this study was to investigate in vivo the gingival microcirculatory changes associated with endodontic treatment using the continuous wave of condensation technique. MATERIALS AND METHODS: Twenty necrotic one canal roots of 20 cooperative patients of both sexes, aged between 20 and 43 years, were selected. All patients were examined by capillaroscopy before, immediately after endodontic treatment, and after 7 days. The last examination was carried out by the same operator, and repeated twice for each examined area: masticatory, buccal and labial mucosa corresponding to the endodontically treated root. All canals were prepared using a simultaneous technique with Ni-Ti files (M…