[Spontaneous reperfusion of the infarct-related artery in patients with ST elevated myocardial infarction].

AIM: To characterize a clinical course of ST elevation myocardial infarction (STEMI) and spontaneous reperfusion of the coronary arteries (SR) as well as in patients after reperfusion thrombolytic therapy (TLT) and/or transluminal balloon coronary angioplasty (TBCA); to compare effectiveness of different approaches to treatment of SR patients: conservative--early medication and active--TBCA on the first postmyocardial 24 hours. MATERIAL AND METHODS: We studied 479 patients admitted to hospital not later than 6 hours since STEMI onset and either having SR (n = 49) or treated using active methods of coronary circulation restoration--prehospital thrombolysis (n = 127), thrombolysis after hospitalization (n = 127), primary TBCA (n = 60) and TBCA after initiation of TLT (n = 116). We made a more detailed analysis on the sample of 149 SR patients. RESULTS: SR was diagnosed in 10.2% cases with STEMI and occurred much earlier than recovery of coronary circulation due to TLT and/or TBCA. Patients with SR developed Q-MI, right ventricular infarction, cardiac failure and atrioventricular block less frequently. They had the lowest peak activity of creatin phosphokinase and a higher left ventricular ejection fraction versus patients without SR (50.7 +/- 6.8 and 45.4 +/- 6.6%, respectively; p < 0.05). As shown by coronaroangiography, SR patients had no "no reflow" phenomenon (0% and 17%, respectively). Active policy of SR patients treatment had no significant advantages over conservative treatment. CONCLUSION: Early SR had more favourable course of MI, less mass of the affected myocardium and better contractile function of the left ventricle. The conservative policy of STEMI treatment in the presence of SR is more effective than the active one if a due control over the patients' condition is provided.

[The role of multidetector computed tomography in detection of myocardial infarction].

UNLABELLED: The aim of the study was to assess the diagnostic value of multidetector computed tomography (MDCT) in detection of myocardial infarction (MI) in acute and chromic stages. MATERIAL AND METHODS: 49 patients with suspected MI were included in the study. In 44 patients the diagnosis of acute MI had been confirmed according to standard criteria. Contrast-enhanced MDCT of the heart and vessels was performed with 4-row MDCT scanner. RESULTS: MDCT detected areas of MI in 39 of 44 patients with proven MI. In 66,7% of cases they were transmural and in 33,3% -- subendocardial. In arterial phase the density of infarcted area was significantly lower than in normal myocardium (mean, 32,6 +/- 3,7 HU versus 101,9 +/- 3,7 HU, correspondingly, p < 0,0001). Mean values of myocardial density in the area of the MI did not change during follow-up (32,6 +/- 3,7 HU vs 41,3 +/- 4,5 HU, ns). In comparison to SPECT, sensitivity and specificity of MDCT in detection of transmural MI were 96,9% and 100%. corr. In the whole group of patients, taking results of troponin test as a gold standard, the sensitivity of MDCT in detection of Q-MI and non-Q MI were 89,1% and 93,5%, correspondingly. CONCLUSION: Cardiac MDCT can reliably detect and localize areas of acute and chronic MI. Contrary to SPECT, it also gives information about stenosis and occlusions in the coronary arteries.

A microdialysis investigation of the release of norepinephrine in the hypothalamus induced by 2-deoxyglucose in awake rats.

The level of norepinephrine in the extracellular space of the lateral hypothalamus was measured by means of intracerebral microdialysis in awake rats. The introduction of desipramine (10 mumole) into the perfusing medium did not affect the basal level of norepinephrine, but increased the release of norepinephrine during local K(+)-stimulation. Neuroglycopenia created under the influence of 500 mg/kg of 2-deoxyglucose induced a threefold increase in the level of norepinephrine in the extracellular space of the hypothalamus, which achieved a maximal value in the first 40 min following the introduction of the substance, and thereafter gradually decreased to the basal level.

[Complex characteristics of the alterations of oncogenes HER-2/ERBB-2, HER-1/ERBB-1, HRAS-1, C-MYC and antioncogenes p53, RB1, as well as deletions of loci of chromosome 17 in colon carcinoma]. / Kompleksnaia kharakteristika povrezhdenii onkogenov HER-2/ERBB-2, HER-1/ERBB-1, HRAS-1, C-MYC i antionkogenov p53, RB1, a takzhe deletsii lokusov khromosomy 17 v kartsinomakh tolstoi kishki.

Abnormalities of some oncogenes, antioncogenes and losses of heterozygosity (LOH) of chromosome 11p, 17p, and 17q in colorectal carcinomas (CC) was studied. Amplification of ERBB-1/HER-1 oncogene was detected in 2 of 56 cases; ERBB-2/HER-2- in 4 of 62. There was a lack of evidence for C-MYC oncogene amplification (67 cases). LOH of chromosome 11p (HRAS-1 probe) was found in 2 of 37 informative (heterozygous) cases; such events were not accompanied by point mutations in "hot" codons (12th or 61st) in the remaining allele. Prevalence of A3 and A4 alleles of HRAS-1 oncogene (68 cases) as compared to healthy donors was noted. RB-1 (41 cases) and p53 (62 cases) suppressor genes did not show any alterations in Southern-blot analysis. LOH of chromosome 17p (YNZ-22 probe) was found in 15 of 26 heterozygous CC; 17q (THH-59 probe)--in 4 of 16. Analysis of 175th codon of p53 gene revealed only one case of mutation in 35 CC studied. Finally, we were able to detect genetic alterations in 23 of 40 (58%) CC, that were studied on each parameter using Southern-blot. We failed to find any correlation between various molecular abnormalities or clinical characteristics. The data obtained are in disagreement with the view concerning frequent involvement of p53 antioncogene in chromosome 17p deletions.

[Simple methods of enzymatic amplification of DNA for clinical practice]. / Prostye metody énzimaticheskoi amplifikatsii DNK dlia klinicheskoi praktiki.

The methods for enzymatic DNA amplification in vitro that allow to avoid the step of preliminary DNA extraction and purification are proposed. Lysates of blood cells in the solution or immobilized on the nylon membrane filters and dried blood spots on the filter paper blotters were used directly in amplification permitting one to solve the problems of adapting the method of polymerase chain reaction in clinical practice, for instance, in massive screening of genome mutations, viral infections etc.

[Nutrients of natural origin for prevention and treatment of radiation disease in experiment]. / Issledovanie radiozashchitnykh svoistv produktov prirodnogo proiskhozhdeniia pri odnokratnom total'nom obluchenii myshei.

The preventive and medical effect of some nutrients of plant origin suggested as food supplement was studied in mice subjected to acute irradiation. The evidence of increased radioresistance was revealed.

[The activity of the monoaminergic systems of the rat hypothalamus in acute stress after chronic stressing]. / Aktivnost' monoaminergicheskikh sistem gipotalamusa krys pri ostrom stresse posle khronicheskogo stressirovaniia.

The influence of chronic stress (footshock combined with randomized light flashes) on acute stress-induced (immobilization) release of noradrenaline, dopamine and serotonin in rat lateral hypothalamus was assessed by microdialysis. The chronic stress resulted in an increase and prolongation of the acute stress-induced release of noradrenaline but not of dopamine and serotonin. The increased rate of accumulation of dioxyphenylacetic acid and unchanged accumulation of homovanillic acid (dopamine metabolites) and dopamine during and after the acute stress in chronically stressed animals reflect a rise of synthetic activity of catecholaminergic systems in response to acute stress and reuptake increase. Marked stress-induced increase in hydroxyindoleacetic acid in chronically stressed rats without any changes in the ST dynamics may be regarded in a similar way. A significant increase in potassium-stimulated release of all the studied monoamines was found while their basal level remained unchanged. The conclusions was made that the hyperergic release of neurotransmitters may be the basis of an inadequate response of animals to acute stress, i.e., one of the neurotic symptoms.

[Features of myocardial metabolism of adenylic nucleotides in patients with paroxysmal tachycardias]. / Osobennosti obmena adenilovykh nukleotidov miokarda u bol'nykh s paroksizmal'nymi takhikardiiami.

The authors revealed that concentrations of inosin, hypoxanthine and their total levels in the arterial blood and the blood of the coronary sinus in patients with paroxysmal tachycardias are higher than the corresponding levels in patients with chronic forms of coronary heart disease and neurocirculatory dystonia. In the absence of tachycardia, there was an accelerated metabolism of adenyl nucleotides of the myocardium: the myocardium produced inosin and extracted hypoxanthine. It is suggested that this type of metabolism of adenyl nucleotides requires additional energy expenditures as compared with the energy supply of the nucleotide metabolism of the healthy myocardium and may be one of the reasons underlying the development of tachycardiac paroxysm, with the place of the localization of the re-entry and/or the presence of coronary heart disease having no significant effect on the metabolism of adenyl nucleotides of the myocardium in such patients. The emergence of tachycardia leads to a decreased extraction of hypoxanthine by the myocardium as compared to the baseline and to insignificant elevation in the production of inosin which causes an increase in the levels of these metabolites in the arterial blood and the blood of the coronary sinus.

[Effect of myocardial ischemia on adenine nucleotide metabolism]. / Vliianie ishemii miokarda na obmen adenilovykh nukleotidov.

Patients with coronary heart disease (CHD), neurocirculatory dystonia and acute myocardial infarction showed statistically significant, positive linear correlations between the levels of inosine and hypoxanthine as well as the total concentration in the arterial blood and the blood from the coronary sinus. The correlation analysis ascertained that CHD patients in the initial state exhibited a considerable extraction of inosine by the myocardium as compared to patients with neurocirculatory dystonia and that in electrically stimulated ischemia it was sharply reduced. Electrostimulation in the group of patients with neurocirculatory dystonia had no effect on the rate of inosine extraction. Acute myocardial infarction was related to a higher rate of inosine extraction and to inosine production in the myocardium, the latter being explained by the degradation of adenyl nucleotides in conditions of acute ischemia. It is outlined that the total level of inosine and hypoxanthine in the arterial blood of patients with acute myocardial infarction may indicate the severity of infarction while its variations over time may be prognostically valuable.

[The role of the endothelium in the reactions of the vascular wall to mechanical stretching and the action of neuromediators]. / Rol' éndoteliia v reaktsiiakh sosudistoi stenki na mekhanicheskoe rastiazhenie i deistvie neiromediatorov.

In isolated rings of the rat aorta, the responses of the smooth muscles to mechanical stretching were studied: the endothelium cells potentiated the relaxation under the stretching. After removal of endothelium cells, acetylcholine induced contraction of the smooth muscle.

[A microdialysis study of noradrenaline release in the hypothalamus evoked by 2-deoxyglucose in waking rats]. / Mikrodializnoe issledovanie vybrosa noradrenalina v gipotalamuse, vyzvannogo 2-dezoksigliukozoi u bodrstvuiushchikh krys.

Intracerebral microdialysis was used to examine extracellular concentrations of noradrenaline (NA) in the lateral hypothalamus of alert rats. Desipramine (0.01 mmol) added to the perfusion medium did not change basal NA release. 2-deoxyglucose-induced (500 mg/kg) neuroglycopenia led to an increase in extracellular NA in hypothalamus which reached maximum 10-30 min after drug administration.

[The effect of tyrosine-containing dipeptide on neuroglycopenia-induced changes in the activities of the sympathetic nervous system and of the systemic hemodynamics in waking rats]. / Vliianie tirozinsoderzhashchego dipeptida na vyzvannye neiroglikopeniei izmeneniia aktivnosti simpaticheskoi nervnoi sistemy i sistemnoi hemodinamiki u bodrstvuiushchikh krys.

A modulatory role of the precursor of catecholamines--tyrosine (TYR)--in 2-deoxyglucose (2DG)-induced changes in blood pressure (BP), renal sympathetic nerve activity (renSNA), plasma levels of epinephrine (EPI) and norepinephrine (NE), total spillover of NE (TSO), and sensitivity of baroreceptor reflex (SBR) is studied. Chronically instrumented male Wistar rats were injected with 2DG (125 - 500 mg/kg iv), and BP, heart rate (HR), renSNA, TSO, EPI, NE, plasma clearance NE (CINE) and SBR were monitored before and after 2DG administration. The responses to 2 DG in control rats were compared with those in rats pretreated with tyrosile-tyrosine dipeptide (TYR-TYR). SBR was estimated by bolus i.v. sodium nitroprusside injection. 2DG evoked an increase in renSNA by 23%, 40-fold and 2.5-fold increases in EPI and NE concentrations, 2,7-fold increase in TSO, a decrease in HR by 5% in 45 min without reliable changes in BP and CINE. TYR-TYR administration did not affect 2DG-induced changes in HR, TSO, EPI and NE concentrations, but potentiated changes in renSNA by 53% and significantly increased BP by 10%. 2DG produced an increase in the chronotropic (by 87%) and sympathetic (by 72%) components of SBR. TYR-TYR restored the normal values of SBR in 2DG-treated rats. Thus, tyrosine modulates 2DG-induced changes in hemodynamic parameters and renSNA and normalizes SBR via central mechanisms.

[Selective activation of adrenaline secretion by the rat adrenal in neuroglycopenia detected via microdialysis]. / Izbiratel'naia aktivatsiia sekretsii adrenalina nadpochechnikom krysy pri neiroglikopenii, obnaruzhivaemaia s pomoshch'iu mikrodializa.

Secretion of adrenaline (A) and noradrenaline (NA) was measured in conscious Wistar rats using the microdialysis probe implanted into the adrenal gland. Changes in contents of A and NA in plasma as well as in dialysate samples in response to i. v. administration of 500 mg/kg 2-deoxy-D-glucose (2-DG) were measured by HPLC with electrochemical detection. 2-DG-induced neuroglycopenia led to a selective increase in adrenal secretion of A which reached maximum 20 m after 2-DG administration, whereas an increase in A and NA contents occurred in plasma. Elevation in the plasma NA content seems to reflect an enhancement in sympathetic nervous activity.

[A microdialysis study of catecholamine secretion in the rat adrenal gland during hypovolemic hypotension]. / Mikrodializnoe issledovanie sekretsii katekholaminov v nadpochechnike krysy pri gipovoliumicheskoi gipotenzii.

In anesthetized rats, concentrations of adrenaline and noradrenaline in sequential 20-min microdialysis samples were measured. Central activation of adrenal secretory function induced by controlled bleeding, increased catecholamine levels in dialysate but the maximal levels were reached after hemorrhage when a decrease in the blood pressure had been stabilized. The results of parallel measurements of catecholamine concentration in dialysate and blood samples suggest that reflex endocrine response of the adrenal gland during hypovolemic hypotension significantly exceeds sympathetic neural response.

[The reactivity and functional heterogeneity of the cerebral arteries]. / O reaktivnosti i funktsional'noi neodnorodnosti arterii golovnogo mozga.

The reactivity and functional heterogeneity of cerebral arteries are maintained by the participation of the endothelium in the regulation of the smooth muscles and by the influence of vasoactive peptides upon the neurotransmitter mechanisms. The initial level of the basal tone plays a major role, too.

[Pharmacological analysis of the role of central alpha-2 adrenergic and imidazoline receptors in mechanism of the hypotensive effect of clonidine in rats]. / Farmakologicheskii analiz roli tsentral'nykh al'fa2-adrenergicheskikh i imidazolinovykh retseptorov v mekhanizme gipotenzivnogo deistviia klonidina u krys.

The role of alpha 2-adrenergic and imidazoline receptors in the hemodynamic response to clonidine (manifested by reduced arterial pressure, heart rate, and renal blood flow rate) was studied by injecting their antagonists with different affinity (yohimbine and idazoxan) into narcotized Sprague--Dawley rats. The local introduction (microinjection into rostral ventrolateral medulla) and systemic administration (intraperitoneal injection) of the drugs showed that the hemodynamic effect of clonidine is mediated predominantly by the central alpha 2-adrenergic receptors, rather than by the imidazoline receptors.

["Silent" myocardial ischemia and the activity of the sympathetic-adrenal system in hypertension patients]. / "Nemaia" ishemiia miokarda i aktivnost' simpatiko-adrenalovoi sistemy u bol'nykh gipertonicheskoi bolezn'iu.

The aim of the study was to assess the sympathoadrenal activity at the time of silent ischemia event in hypertensive patients. In 15 hospitalized hypertensive patients having silent ischemia event during Holter ECG monitoring while walking, blood samples for catecholamines were taken at the time of silent ischemia event, pointed with alarm by the real time ECG "Q Med" monitor (USA). Control blood samples were taken under the same conditions without ST-segment depression. Plasma noradrenaline (NA) during silent ischemia was significantly higher than the control level without ischemia (458 +/- 71 ng/l vs 717 +/- 95 ng/l) (p less than 0.01). The changes in plasma NA correlated with left ventricular mass assessed by echocardiography (r = 0.70, p less than 0.01). The role of sympathoadrenal hyperactivity in the genesis of silent myocardial ischemia in patients with essential hypertension is discussed.

[Study of the bending and torsion rigidity of the flexible elements of endoscopes]. / Issledovanie zhestkosti na izgib i kruchenie gibkikh élementov éndoskopov.

The method and a special set for measuring the rigidity in bending and the torsion rigidity of flexible endoscopic elements under experimental and operating conditions are described. The set consists of the following components: a base, two racks, three removable holders, a height gauge, a set of weights, a set of inserts allowing flexible endoscopic pieces 4-16 mm in diameter to be fixed in the holder. Some experimental results are given.

[Study of catecholamine secretion by the rat adrenal glands using microdialysis in vivo]. / Issledovanie sekretsii katekholaminov v nadpochechnike krysy s pomoshch'iu mikrodializa in vivo.

Microdialysis technique has been developed to study secretory function of the adrenal gland in anesthesized rats. Concentration of adrenaline and noradrenaline in sequential 20 min microdialysis samples was measured by HPLC with electrochemical detection. The suitability of method was tested by local and central stimulation of catecholamine secretion. In the first case 100 mmol of KCl or 1 mmol of carbachol were added to perfusion medium, in the second one hypovolemic hypotension was applied. All the stimuli used increased catecholamine levels in the adrenal gland dialysates. Institute of Experimental Cardiology of the All-Union.

[Effect of nitrobenzylthioinosine accumulated by the heart in rats and guinea pigs on the release of adenine nucleotide breakdown products during ischemia and reperfusion]. / Vliianie nitrobenziltioinozina, nakoplennogo serdtsem krys i morskikh svinok, na vysvobozhdenie produktov raspada adeninnukleotidov pri ishemii i reperfuzii.

The uptake kinetics of nitrobenzyl thioinosine (NBTI), a nucleoside transport inhibitor, was studied in the isolated Langendorf-perfused guinea pig and rat hearts. In rats the rate constant of NBTI uptake was higher and the extent of NBTI accumulation was less than in guinea pig hearts. Heart-accumulated NBTI inhibited the total release of adenine nucleotide degradation products (ANDP) during reperfusion 25 min after global ischemia. The effect was more pronounced in guinea-pig hearts-in accordance with observed higher myocardial concentration of NBTI. Unlike other ANDP, the release adenosine by guinea-pig hearts was unchanged and that by rat hearts increased. In spite of significant NBTI-induced decrease of ANDP losses recovery of contractile function during reperfusion was not observed to improve.