18F-fluorodeoxyglucose accumulation in the heart, brain and skeletal muscle of rats; the influence of time after injection, depressed lipid metabolism and glucose-insulin

BACKGROUND: to study the effect of lipid depressing drugs on 18FDG myocardial concentration. The changes of 18FDG uptake in myocardium, brain and skeletal muscle of rats were compared as influenced by acipimox, tyloxapol and glucose with insulin. MATERIAL AND METHODS: 5.55 MBq of 18FDG were administered to Wistar rats. Control rats were killed 15, 30, 45 and 60 minutes following intravenous injection and the radioactivity concentration (cpm/g of tissue) in relation to injected cpm was determined in a well crystal adjusted to 511 KeV in order to check the time of maximal 18FDG tissue uptake. The radioactivity in myocardium, skeletal muscle and brain in intact animals was compared with that of rats treated with tyloxapol (tritton WR 1339, 125 mg intravenously immediately before 18FDG injection), acipimox (nicotinic acid derivative, 25 mg by stomach cannula 15 minutes before 18FDG), or glucose with insulin (intravenous injection of 0.04 g and 0.04 UI immediately before 18FDG). The animals were killed 45 minutes following 18FDG injection. RESULTS: Tyloxapol and acipimox significantly elevated myocardial 18FDG concentration (tyloxapol +37% and acipimox +48%), but the increase in 18FDG concentration after glucose and insulin was slight and insignificant. The changes in skeletal muscle after lipid depressing agents were quite contrasting; the decrease in 18FDG concentration was -74% after tyloxapol and -44% following acipimox administration. The accumulation of 18FDG in brain was not influenced markedly by the drugs used or by glucose with insulin. CONCLUSION: The highest 18FDG uptake in myocardium could be achieved by depressing the lipid metabolism and not by administration of glucose with insulin only. A marked increase in glucose accumulation in myocardium is not possible without previous shift from the utilisation of fatty acids. This finding is fully in agreement with present knowledge about energetic metabolism of myocardium

Pretest clinical diagnosis of coronary artery disease and stress myocardial perfusion scintigram.

BACKGROUND: To assess the probability of perfusion defects at exercise stress myocardial perfusion SPECT scintigraphy from pretest clinical diagnosis (medical personal history, previous ergometric investigation). To determine the value of clinical facors for probability of scintigraphic defects with respect to avoiding unnecessary investigation in subjects with low probability of abnormal scintigrams. MATERIAL AND METHODS: 2143 subjects (1235 men, 908 women) were investigated by SPECT perfusion scintigraphy at stepwise increasing exercise stress. They were divided into three groups with regard to their medical history and exercise test at scintigraphy: subjects without any signs of coronary artery disease (CAD), patients with high likelihood of CAD (i.e., typical anginal pain, in particular at stress, positive stress ECG changes, angiographically documented important CAD) and patients after myocardial infarction (MI). Important risk factors (hypertension, diabetes, age and sex), as well as the role of revascularisation procedures, were taken into account for multiple logistic regression in order to express their importance for the odds of scintigraphic defect visualisation. RESULTS: Perfusion scintigraphic defects (PSD) were found in 5.2% of subjects without signs of CAD, in contrast to patients with manifest CAD (68.8% with PSD) and in those after MI (90.2% with PSD). There were other important factors corroborating the likelihood of PSD (in decreasing order of importance): dia- betes, male, ECG changes at stress, increasing age. Successful revascularisation improved scintigraphic images. CONCLUSION: The examination of CAD symptom-free subjects, in particular with atypical chest discomfort, is useless. SMPS in patients after documented MI is to be carried out for other intended purposes, not for CAD diagnosis only. SMPS is highly recommended in patients with CAD symptoms and high CAD probability in order to decide further treatment and prognosis

Chirurgicke reseni extremni obezity. Laparoskopicka neadjustabilni gastricka bandaz.

Gastric banding as one of the possible surgical treatments for controlling morbid obesity is available, effective method for long-term controlling morbid obesity. The most frequent late complication after GB is upper pouch dilatation and slippage of anterior stomach wall above bandage. To prevent this complication we modified method of laparoscopic nonadjustable gastric banding. We create the cuff of anterior stomach wall about bandage. On the base of results of our study we can prove, that modification of LNGB with creating cuff over the banding is satisfactory. Our study showed decrease of dilatation and slippage in experimental group and the mean volume of gastric pouch was smaller in this group then in control group.Summary in EnglishAvailable from STL, Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Kostni densitometrie. Indikace k vysetreni u osteoporozy a nektere metodicke problemy v klinicke praxi.

Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Uncertainty-adjusted inductive matrix completion with Graph Neural Networks

Ministry of Education, Singapore under its Academic Research Funding Tier

The chlorophyll a fluorescence induction pattern in chloroplasts upon repetitive single turnover excitations: Accumulation and function of QB-nonreducing centers

The increase of chlorophyll fluorescence yield in chloroplasts in a 12.5 Hz train of saturating single turnover flashes and the kinetics of fluorescence yield decay after the last flash have been analyzed. The approximate twofold increase in Fm relative to Fo, reached after 30-40 flashes, is associated with a proportional change in the slow (1-20 s) component of the multiphasic decay. This component reflects the accumulation of a sizeable fraction of QB-nonreducing centers. It is hypothesized that the generation of these centers occurs in association with proton transport across the thylakoid membrane. The data are quantitatively consistent with a model in which the fluorescence quenching of QB-nonreducing centers is reversibly released after second excitation and electron trapping on the acceptor side of Photosystem I