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Doppler parameters of myocardial dysfunction in very low birth weight infants
Širc, Jan ; Straňák, Zbyněk (advisor) ; Plavka, Richard (referee) ; Janota, Jan (referee)
Preterm neonate is exposed to significant hemodynamic changes after delivery. Cardiac and extracardiac shunts, especially ductus arteriosus, play an important role in this process. Failure of postnatal adaptation and persistent patent ductus arteriosus (PDA) may lead to cardiac overload and circulatory failure with hypoperfusion of vital organs and in turn adversely affect the short-term and long-term morbidity and mortality of these patients. Newborns with very low birth weight are at highest risk, however the possibilities for diagnosing circulatory failure in this patient group are limited. Clinical presentation and physical examination are nonspecific and involve subjective measures. Functional echocardiography provides information on systolic and diastolic heart function as well as the possibility to measure cardiac output and superior vena cava flow (SVC flow). Much of what is known about ventricular function pertains to systole rather than diastole. Near infrared spectroscopy provides another noninvasive method, enabling the measurement of tissue oxygenation including that of the brain. Cerebral oxygenation can be measured by placing the probe on the head of the neonate. Further possibility to help diagnose circulatory system failure are biochemical markers, commonly used in diagnosing...
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Lung Biotrauma
Vobruba, Václav ; Martásek, Pavel (advisor) ; Straňák, Zbyněk (referee) ; Pachl, Jan (referee)
The aim of this study was to investigate longitudinal changes of the pulmonary inflammatory process as a result of mechanical stress due to mechanical ventilation (MV). The concentrations of IL-8, TNF-α, MIP-1β, nitrites/nitrates and inducible nitric oxide synthases (iNOS) were investigated indicate in bronchoalveolar lavage (BAL). 23 piglets were divided into three groups. Group I: animals breathing spontaneously; group II: MV (TV=7 ml/kg, PEEP= 5 cmH2O); group III: MV (TV=15 ml/kg ; PEEP= 0 cmH20). The focus of the study was the influence of CMV on the hemodynamics, pulmonary function, changes in certain chemokine and cytokine levels, and the inducible NOS and nitrite/nitrate production in BAL. A significant increase in heart rate was found in Group III during the 3rd hour of the experiment - both in relation the the initial levels and to the levels of the other groups (p = 0.01 and 0.008 respectively). During the same time period, a significant drop in blood pressure readings was detected in this group as well. A significant increase of the CVP levels was found in Group III starting already from the 1st hour of the experiment. CMV with high tidal volumes lead to a sinificant decrease in lung compliance in Group III already from the 1st hour of the experiment (p < 0.001). Concentrations of...
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Nanotechnology in the intensive care: Intravascular biocompatibility of carbon nanomaterials-effect of carbon nanotubes on blood platelets
Šemberová, Jana ; Straňák, Zbyněk (advisor) ; Dyr, Jan (referee) ; Hubálek Kalbáčová, Marie (referee)
Nanotechnology in the intensive care: Intravascular biocompatibility of carbon nanomaterials - effect of carbon nanotubes on blood platelets. EFFECT OF CARBON NANOTUBES ON BLOOD PLATELETS Carbon nanotubes (CNTs) are among the principal materials currently used in biomedical nanotechnologies. CNTs possess superior mechanical and chemical characteristics including enormous tensile strength, elasticity and conductivity. As a result they are very popular and attractive for use in various biomedical applications. Many of these applications may lead ultimately to contact of carbon nanomaterials and blood. Furthermore, CNTs may also be present intravascularly as a result of environmental or occupational exposure. Therefore, the investigation of the intravascular biocompatibility of CNTs is a critical safety issue. We studied the effects of structurally different purified CNT materials from different manufacturers on human platelets and compared their effects to amorphous carbon black nanoparticles (ACB), fullerene C60, fullerenol C60(OH)24 and NIST standard polystyrene nanobeads (PNBs). Using light transmission aggregometry of human platelet rich plasma, we found that various CNTs induce PLT aggregation and this occurs in a concentration dependent manner. In contrast to CNTs, ball-like shaped fullerene...
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How to decrease severe hospital acquired infection in newborns admitted to NICU
Bořkovcová, Tereza ; Straňák, Zbyněk (advisor)
With the rapid development of science and technology and related advances in medical care, pediatricians are, respectively, neonatologové, to save less and still nezralejší newborn. To care for critically ill newborns often (premature low gestational age or congenital defects) are inherently large number of invasive diagnostic and therapeutic procedures, bringing a number of risks as nosocomial infections (in Anglo-Saxon literature referred to as NI = nosocomial infection, HAI = Hospital-Acquired infection or healthcare-associated infection). These are today high time contributor to perinatal morbidity and mortality. And not only that. Extension of stay in NICU newborns increases additional risk of hospital infections, prolong suffering, and suffering newborns and families themselves, and not increase the extent cost of hospital care. As is clear from the conclusions various international studies, regular and consistent compliance often quite elementary hygiene habits (such as hand washing and disinfection of medical and parents before any contact with the newborn, disinfection stethoscope, etc..), can prevent the emergence of nosocomial infections or at least substantially reduce this risk.
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Actual options in prevention of premature labor
Hjertaas, Benedikte ; Straňák, Zbyněk (advisor)
The aim of this thesis is to review the current options for treating premature labor. It will focus on evaluating the efficacy of the various therapies based on the comparisons of data presented in available articles on clinical trials. The results show that many of the treatments used today yield little or no improvement. And for those that are proven to be effective it is difficult to distinguish the patients that can benefit from the treatment from those that will not.
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Actual options in prevention of premature labour
Michalcová, Jana ; Straňák, Zbyněk (advisor)
Premature labour is the main cause of neonatal morbidity and mortality in developed countries and represents a major perinatology and socio-economic problem. Currently we speak about preterm parturition syndrome, that can be induced by various factors, from which inflammation is considered as the most important, mainly of infectious etiology. Combination of anamnesis, ultrasound cervicometry and cervicovaginal fetal fibronectin test is presently considered as the most reliable in diagnostics of premature labour. These examinations have a high negative predictive value. The primary objective of tocolysis is to delay delivery in order to save time for induction of lung maturity and transfer in utero to specialized centres. Oxytocin antagonists are currently considered as ideal tocolytics. Administration of antibiotics at spontaneous premature labour with intact membranes and without any signs of infection is not recommended. In case of premature rupture of membranes, infection may represent its cause or possible secondary complication as well. That is why antibiotics should always be administered in this case, ideally erythromycin. Further management depends paricularly on gestational age of the fetus. Efficacious primary prevention of premature labour is not possible so far. The means of secondary prevention...
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The mechanism of The Influence of Hypoxia on The Fetoplacental Vascular Bed
Jakoubek, Vít ; Hampl, Václav (advisor) ; Zoban, Petr (referee) ; Vízek, Martin (referee) ; Straňák, Zbyněk (referee)
Placental hypoxia is commonly considered to play an important role in the development of several perinatal and neonatal diseases such as intrauterine growth retardation (IUGR) or preeclampsia. In this disertation we therefore tried to (at least partially) solve this problem by answering the question how do acute and chronic hypoxia affect fetoplacentar vasculature. Unlike all vascular beds with the exception of the pulmonary circulation, fetoplacental vessels respond to acute hypoxia with vasoconstriction ( HFPV). This mechanism presumably diverts blood flow from poorly oxygenated areas towards regions with better O2 supply. We already know, that hypoxia inhibits potassium channels and thus causes depolarization in fetoplacental vascular smooth muscle. We propose that this hypoxia-induced depolarization leads to vasoconstriction by activating voltage- dependent calcium (Ca) channels and Ca influx. We performed our first experiment on the preparation of dually perfused cotyledon of the human placenta, which we gained immediately after uncomplicated spontaneus deliveries or elective caesarian sections. The preparation was perfused with Krebs' saline with dextran and meclophenamate and gased with 40% O2, 5% CO2 a 55% N2. We compared HFPV, which was elicited by changing gasing of the perfusate to the...
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