Annals of the New York Academy of Sciences, ISSN 0077-8923 Volume 473, Issue 1 (December 15, 1986)
xii, 560 stran : ilustrace ; 23 cm
- MeSH
- Behavior drug effects MeSH
- Electrochemistry MeSH
- Brain Chemistry MeSH
- Neurochemistry methods MeSH
- Perfusion MeSH
- Psychiatry MeSH
- Publication type
- Congress MeSH
- Collected Work MeSH
- Conspectus
- Psychologie
It has been shown that besides positron emission tomography, single photon emission computed tomography and magnetic resonance imaging; contrast echocardiography can be used for qualitative and quantitative myocardial perfusion assessment. In this review, the properties of ultrasound contrast agents, imaging techniques and acquisition methods are shortly described and the possibilities of perfusion echocardiography are summarized. The main focus is put on the description of three perfusion models: mathematical models, physical models assuming an ideal inflow and physical models including inflow measurement.
- MeSH
- Echocardiography MeSH
- Image Interpretation, Computer-Assisted MeSH
- Contrast Media diagnostic use MeSH
- Coronary Circulation MeSH
- Humans MeSH
- Models, Cardiovascular MeSH
- Predictive Value of Tests MeSH
- Myocardial Perfusion Imaging methods MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Review MeSH
A convenient geometrical description of the microvascular network is necessary for computationally efficient mathematical modelling of liver perfusion, metabolic and other physiological processes. The tissue models currently used are based on the generally accepted schematic structure of the parenchyma at the lobular level, assuming its perfect regular structure and geometrical symmetries. Hepatic lobule, portal lobule, or liver acinus are considered usually as autonomous functional units on which particular physiological problems are studied. We propose a new periodic unit-the liver representative periodic cell (LRPC) and establish its geometrical parametrization. The LRPC is constituted by two portal lobulae, such that it contains the liver acinus as a substructure. As a remarkable advantage over the classical phenomenological modelling approaches, the LRPC enables for multiscale modelling based on the periodic homogenization method. Derived macroscopic equations involve so called effective medium parameters, such as the tissue permeability, which reflect the LRPC geometry. In this way, mutual influences between the macroscopic phenomena, such as inhomogeneous perfusion, and the local processes relevant to the lobular (mesoscopic) level are respected. The LRPC based model is intended for its use within a complete hierarchical model of the whole liver. Using the Double-permeability Darcy model obtained by the homogenization, we illustrate the usefulness of the LRPC based modelling to describe the blood perfusion in the parenchyma.
- MeSH
- Central Venous Catheters utilization MeSH
- Vascular Access Devices utilization MeSH
- Chemotherapy, Cancer, Regional Perfusion * methods utilization MeSH
- Cytostatic Agents * administration & dosage therapeutic use MeSH
- Humans MeSH
- Antineoplastic Agents administration & dosage therapeutic use MeSH
- Statistics as Topic MeSH
- Outcome and Process Assessment, Health Care * methods utilization MeSH
- Check Tag
- Humans MeSH
- MeSH
- Tomography, Emission-Computed, Single-Photon methods instrumentation utilization MeSH
- Humans MeSH
- Image Processing, Computer-Assisted methods utilization MeSH
- Software MeSH
- Statistics as Topic MeSH
- Models, Theoretical MeSH
- User-Computer Interface MeSH
- Myocardial Perfusion Imaging methods instrumentation utilization MeSH
- Check Tag
- Humans MeSH
Long-term continuous protein production can be reached by perfusion operation. Through the continuous removal of waste metabolites and supply of nutrients, steady-state (SS) conditions are achieved after a certain transient period, where the conditions inside the reactor are not only uniform in space but also constant in time. Such stable conditions may have beneficial influences on the reduction of product heterogeneities. In this study, we investigated the impact of perfusion cultivation on the intracellular physiological state of a CHO cell line producing a monoclonal antibody (mAb) by global transcriptomics and proteomics. Despite stable viable cell density was maintained right from the beginning of the cultivation time, productivity decrease, and a transition phase for metabolites and product quality was observed before reaching SS conditions. These were traced back to three sources of transient behaviors being hydrodynamic flow rates, intracellular dynamics of gene expression as well as metabolism and cell line instability, superimposing each other. However, 99.4% of all transcripts and proteins reached SS during the first week or were at SS from the beginning. These results demonstrate that the stable extracellular conditions of perfusion lead to SS also of the cellular level.
- MeSH
- Cell Culture Techniques methods MeSH
- CHO Cells MeSH
- Cricetulus MeSH
- Glycosylation MeSH
- Antibodies, Monoclonal analysis genetics MeSH
- Perfusion methods MeSH
- Proteome analysis genetics MeSH
- Proteomics methods MeSH
- Transcriptome * MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Cíl: Zhodnotit možnosti provedení zátěžové perfuze mozku po aplikaci acetazolamidu a možnosti posouzení cerebrovaskulární rezervy (CVR). Metoda: Během 12 měsíců bylo provedeno celkem deset vyšetření objemového perfuzního CT mozku v zátěži po podání 1000 mg acetazolamidu intravenózně, jednalo se o sedm mužů a tři ženy (průměrný věk 54,4 let, rozpětí 28-72 let). V souboru byl sledován stav cerebrovaskulární rezervy pomocí porovnání klidové a zátěžové perfuzní mapy s hodnocením perfuzního objemu (CBV) a středního tranzitního času (MTT). Výsledky: U všech čtyř nemocných s okluzí vnitřní krkavice na podkladě spontánní disekce nebylo prokázáno snížení CVR. Ze šesti nemocných s aterosklerotickou okluzí vnitřní krkavice nebylo snížení CVR přítomné u dvou nemocných, ze čtyř nemocných s vyčerpáním CVR byl u třech nemocných proveden EC-IC bypass. Závěr: Zátěžové perfuzní zobrazení mozku s podáním acetazolamidu pomocí CT je testem vhodným k posouzení CVR u nemocných, u nichž je zvažována indikace EC-IC bypassu. Nejvhodnějšími mapami pro posuzování CVR jsou mapy MTT.
Aim: To assess the effectiveness of acetazolamide challenge perfusion CT of the brain in detection of cerebrovascular reserve. Method: During twelve months, 10 examinations of volume perfusion CT of the brain was performed during acetazolamide challenge. The sample of patients consisted of 7 males and 3 females (mean age 54,4 years, range 28-72). The cerebrovascular reserve (CVR) was assessed using the comparison of perfusion maps during rest and challenge, cerebral blood volume (CBV) and mean transit time (MTT) were used. Results: Significant decrease of CVR was not found in any of four patients with occlusion of internal carotid after spontaneous dissection. In four of six patients with atherosclerotic occlusion of internal carotid, the significant decrease of CVR was found; three of them underwent EC-IC bypass graft surgery. In remaining two patients was found no decrease of CVR. Conclusion: Acetazolamide challenge test is useful test in detection of CVR, according tis test is possible to stratify the patients in whom the EC-IC surgery may improve the brain blood perfusion.
- MeSH
- Acetazolamide * diagnostic use MeSH
- Carotid Arteries physiology pathology MeSH
- Cerebrovascular Disorders diagnosis complications MeSH
- Humans MeSH
- Cerebrovascular Circulation * drug effects MeSH
- Perfusion Imaging methods instrumentation utilization MeSH
- Tomography, X-Ray Computed * methods instrumentation utilization MeSH
- Retrospective Studies MeSH
- Cerebral Revascularization methods utilization MeSH
- Statistics as Topic MeSH
- Outcome and Process Assessment, Health Care MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Je podán přehled o současném stavu nukleární kardiologie, zejména o pokroku v zobrazování myokardiální perfuze jednofotonovou emisní výpočetní tomografií (SPECT). Standardem je v současnosti gated SPECT vyšetření umožňující posouzení perfuze i funkce levé komory. Kvantifikace rozsahu a závažnosti perfuzních defektů pomocí stanovení sumačního zátěžového skóre (SSS) přináší důležité informace při rozhodování o dalším terapeutickém postupu. U pacientů s normální perfuzí resp. s mírně abnormální perfuzí (SSS 4 - 8) je riziko srdeční smrti nízké (< 1 % ročně) a lze upřednostnit medikamentózní terapii. Naopak u pacientů se střední resp. těžkou abnormalitou perfuze (SSS > 8) je preferována invazivní strategie.
A review is given about the present state of nuclear cardiology, particularly about the progress in single photon emission computed tomography (SPECT). ECG-gated SPECT examination is a current standard which makes possible the evaluation of left ventricular (LV) myocardial perfusion and function. A spectrum of patients referred for this examination changes significantly. Myocardial perfusion SPECT plays the important role in diagnostics of coronary artery disease (CAD), however, there is nowadays growing significance of the evaluation of prognosis in patients known or suspected CAD, detection of ischemia CAD in some patients after coronary revascularization, and viability assessment in patients with LV dysfunction. Quantification of the extent and severity of perfusion defects by means of a summed stress score (SSS) yields important information on decision concerning further therapy. In patients with the normal perfusion (SSS 0–3) or with the mildly abnormal perfusion (SSS 4–8) the risk of heart death is low (< 1 % annually) and medicamentous therapy can be preferred. On the contrary, in patients with the moderate or severe abnormality of perfusion (SSS > 8) preference is given to the invasive strategy.
BACKGROUND: Regional hypoperfusion has been associated with the development of postoperative organ dysfunction in cardiac surgery involving cardiopulmonary bypass (CPB). Direct tissue oxymetry is a potentially new method for monitoring the quality of the peripheral tissue perfusion during CPB. The aim of this study was to assess the effects of CPB in skeletal muscle oxygenation when measured in the deltoid muscle by direct oxymetry during perioperative period. METHOD: Seven patients underwent on-pump coronary artery bypass grafting. Direct oxymetry was performed by an optical cathether introduced into the deltoid muscle. Continuous measurement was made during the surgical procedure and the postoperative period. Mean arterial blood pressure, blood flow during CPB, laboratory markers of tissue hypoperfusion, blood gases and body temperature were also recorded. RESULTS: Interstitial muscle tissue oxygen tension (pO(2)) decreased after the introduction to anaesthesia and, more significantly, during CPB. After the disconnection from CPB at the end of the operation, the pO(2) returned to pre-anaesthetic values. During the first hours after admission of the patients to the intensive care unit, the pO(2) progressively decreased, reached a minimum value after four hours, and increased slowly thereafter. There was a significant correlation of pO(2) with mean arterial blood pressure and blood flow during that time. CONCLUSION: The result of this first measurement seems to demonstrate that the standard technique of conducting cardiopulmonary bypass produces low muscle oxygen tension and, thus, little perfusion of skeletal muscle. The data also indicate that both high mean arterial blood pressure and high flow are necessary during CPB to ensure skeletal muscle perfusion. The investigation is continuing.
- MeSH
- Blood Gas Analysis MeSH
- Cardiopulmonary Bypass instrumentation methods MeSH
- Coronary Artery Bypass instrumentation methods MeSH
- Blood Pressure MeSH
- Oxygen metabolism MeSH
- Humans MeSH
- Deltoid Muscle metabolism MeSH
- Oximetry instrumentation methods MeSH
- Perfusion instrumentation methods MeSH
- Preoperative Period MeSH
- Regional Blood Flow MeSH
- Aged MeSH
- Body Temperature MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
