Validation of a third-generation Doppler system for studies of detailed aortic flow

1984 ◽  
Vol 247 (5) ◽  
pp. H847-H856
Author(s):  
J. A. Rumberger ◽  
C. F. Fastenow ◽  
D. L. Laughlin ◽  
M. L. Marcus
Keyword(s):  
Velocity Profile ◽  
Volume Flow ◽  
Aortic Diameter ◽  
Doppler Velocity ◽  
Third Generation ◽  
Flow Rates ◽  
Doppler System ◽  
Aortic Hemodynamics

A multigated, third-generation Doppler velocity system has been developed and validated for detailed studies of aortic hemodynamics. The Doppler system employs a single 3-mm, 5-MHz crystal applied to the aorta at a fixed angle with respect to the flow axis and is capable of measuring velocity profile, blood vessel diameter, and integrated volume flow on a continuous, real-time basis. This represents a major developmental advance over existing first-generation, continuous-wave and second-generation, single-gated pulsed Doppler systems. Validation studies have been performed in vitro and in dogs. Aortic diameter was measured simultaneously with the volumetric Doppler system and with sonomicrometer probes. During changes in aortic diameter between 8 and 18 mm (n = 18), produced by temporary pulmonary artery occlusion or epinephrine infusion, quantitative agreement between the Doppler and sonomicrometer probes was found (r = 0.96). Velocity profile measurements and axial velocity values made with the Doppler system compared favorably with hot-film anemometry studies in vitro and in vivo. Although the current system is nondirectional, measurements of phasic aortic volume flow and absolute-time-averaged changes in flow rates showed an excellent correlation with chronically placed electromagnetic flow probes over a broad range of flow rates in vivo (1-5 l/min, n = 36, r = 0.95). This third-generation Doppler system should prove useful in clinical and research studies of detailed aortic hemodynamics.

scholarly journals A third-generation bisphosphonate, minodronic acid (YM529), successfully prevented the growth of bladder cancer in vitro and in vivo

2006 ◽  
Vol 95 (10) ◽  
pp. 1354-1361 ◽  
Author(s):  
K Sato ◽  
T Yuasa ◽  
M Nogawa ◽  
S Kimura ◽  
H Segawa ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Third Generation ◽  
Minodronic Acid

scholarly journals Assessment of Lentiviral Vector Mediated CFTR Correction in Mice Using an Improved Rapid in vivo Nasal Potential Difference Measurement Protocol

2021 ◽  
Vol 12 ◽  
Author(s):  
P. Cmielewski ◽  
J. Delhove ◽  
M. Donnelley ◽  
D. Parsons
Keyword(s):  
Ion Transport ◽  
Lentiviral Vector ◽  
Chloride Transport ◽  
Diagnostic Technique ◽  
Potential Difference ◽  
Third Generation ◽  
Flow Rates ◽  
Measurement Protocol ◽  
Nasal Potential Difference

Cystic Fibrosis (CF) is caused by a defect in the CF transmembrane conductance regulator (CFTR) gene responsible for epithelial ion transport. Nasal potential difference (PD) measurement is a well established diagnostic technique for assessing the efficacy of therapies in CF patients and animal models. The aim was to establish a rapid nasal PD protocol in mice and quantify the efficacy of lentiviral (LV) vector-based CFTR gene therapy. Anaesthetised wild-type (WT) and CF mice were non-surgically intubated and nasal PD measurements were made using a range of buffer flow rates. Addition of the cAMP agonist, isoproterenol, to the buffer sequence was then examined. The optimised rapid PD technique was then used to assess CFTR function produced by second and third generation LV-CFTR vectors. V5 epitope tagged-CFTR in nasal tissue was identified by immunohistochemistry. When intubated, mice tolerated higher flow rates. Isoproterenol could discriminate between WT and CF mice. Improved chloride transport was observed for the second and third generation LV-CFTR vectors, with up to 60% correction of the cAMP-driven chloride response towards WT. V5-CFTR was located in ciliated epithelial cells. The rapid PD technique enables improved functional assessment of the bioelectrical ion transport defect for both current and potential CF therapies.

scholarly journals Mechanism of action of the third generation benzopyrans and evaluation of their broad anti-cancer activity in vitro and in vivo

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Alexander J. Stevenson ◽  
Eleanor I. Ager ◽  
Martina A. Proctor ◽  
Dubravka Škalamera ◽  
Andrew Heaton ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Third Generation ◽  
The Third ◽  
Anti Cancer ◽  
Cancer Activity

scholarly journals Unsteady Unidirectional MHD Flow of Voigt Fluids Moving between Two Parallel Surfaces for Variable Volume Flow Rates

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Wei-Fan Chen ◽  
Hsin-Yi Lai ◽  
Cha'o-Kuang Chen
Keyword(s):  
Velocity Profile ◽  
Volume Flow Rate ◽  
Linear Acceleration ◽  
Mhd Flow ◽  
Volume Flow ◽  
Magnetic Field Effects ◽  
Piston Motion ◽  
Transform Method ◽  
Flow Rates ◽  
Parallel Surfaces

The velocity profile and pressure gradient of an unsteady state unidirectional MHD flow of Voigt fluids moving between two parallel surfaces under magnetic field effects are solved by the Laplace transform method. The flow motion between parallel surfaces is induced by a prescribed inlet volume flow rate that varies with time. Four cases of different inlet volume flow rates are considered in this study including (1) constant acceleration piston motion, (2) suddenly started flow, (3) linear acceleration piston motion, and (4) oscillatory piston motion. The solution for each case is elaborately derived, and the results of associated velocity profile and pressure gradients are presented in analytical forms.

scholarly journals ANTIPSYCHOTICS: FROM THE FIRST TO THE THIRD GENERATION

2020 ◽  
Author(s):  
Nataliia N. Petrova ◽  
Alexander G. Sofronov
Keyword(s):  
Comparative Analysis ◽  
Negative Symptoms ◽  
Third Generation ◽  
Antipsychotic Therapy ◽  
Persistent Symptoms ◽  
D3 Receptors ◽  
The Third ◽  
Personalized Approach

The review is devoted to comparative analysis of antipsychotics of three generations. When writing the review, a systematic search in the databases PubMed, Medline, Elsevier was carried out, a simple filter for keywords was used. Pharmacological and clinical issues of antipsychotic therapy were considered, the mechanisms of action of antipsychotics of different generations were revealed. Current trends in the development of approaches to the therapy of schizophrenia and the concept of atypicality of antipsychotics were discussed. A comparative analysis of indications for use, tolerance (safety of use) and efficacy of various antipsychotic drugs with an emphasis on the effect on negative (primary, persistent) symptoms has been conducted. The hypothesis underlying new approaches to the therapy of schizophrenia, based on the effect on dopamine autoreceptors, consisting of a high density of D2 and low density of D3 receptors, has been presented. It has been shown that antipsychotics of the third generation open up new possibilities in the therapy of psychosis within the framework of a personalized approach in psychiatry with the achievement of functional recovery of patients. The characteristics of the drugs representatives of the third generation of antipsychotics aripiprazole and cariprazine were given. The uniqueness of cariprazine as the only drug that inhibits D3 receptors in vitro, as well as in vivo in patients with schizophrenia was emphasized. The data of evidence-based studies of the effectiveness of cariprazine in the treatment of negative, including predominant negative symptoms were presented.

Novel catheterization technique for the in vivo measurement of pulmonary vascular responses in rats

1998 ◽  
Vol 274 (4) ◽  
pp. H1218-H1229 ◽  
Author(s):  
Albert L. Hyman ◽  
Qingzhong Hao ◽  
Allen Tower ◽  
Philip J. Kadowitz ◽  
Hunter C. Champion ◽  
...  
Keyword(s):  
Pulmonary Arterial Pressure ◽  
Flow Curves ◽  
Pressure Flow ◽  
Flow Rates ◽  
Rat Lungs ◽  
Pulmonary Vasodilator ◽  
Catheterization Technique ◽  
Pulmonary Arterial

A novel cardiac catheterization technique was devised to investigate the pulmonary arterial pressure-blood flow relationship in intact spontaneously breathing rats (ISBR) under physiological conditions with constant left atrial pressure and controlled blood flow within the normal range. Observations using this new technique in vivo were contrasted with data derived with isolated perfused rat lungs in vitro. Unlike results in in vitro isolated perfused rat lungs, the pressure-flow curves in vivo were curvilinear, with pulmonary artery pressure increasing more rapidly at low pulmonary blood flows of 4–8 ml/min and less rapidly at higher flow rates. Pressure-flow curves were reproducible and were not altered by 1–1.5 h of arrested perfusion, cyclooxygenase blockade, or perfusion with aortic or mixed venous blood. In contrast to results in in vitro isolated perfused rat lungs, N G-nitro-l-arginine methyl ester (l-NAME) increased pulmonary arterial pressure at all but the lowest flow rates with a slight effect on the curvilinear pressure-flow relationship. l-NAME reversed pulmonary vasodilator responses to acetylcholine and bradykinin and enhanced the pulmonary vasodilator response to nitroglycerin. The present data suggest that actively induced pulmonary hypertension is under greater control by endothelium-derived relaxing factor (EDRF). Unlike previous results in in vitro perfused rat lungs, results in ISBR demonstrate that the pulmonary vasodilator response to adrenomedullin-(13—52) is not mediated by calcitonin gene-related peptide receptors, which are not coupled to the release of EDRF. These results indicate that this novel technique may provide a useful model for the study of the pulmonary circulation in the intact chest rat.

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