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Biomedical subjects

D Novosel

Publications and source records attributed to D Novosel.

At least 19 recordsLinked to original sources
PubMed1992

Assessment of right ventricle dimensions with microsonometry in anesthetized rabbits.

Dimension measurements of the right ventricle are difficult to obtain because of its complex geometry, thus we evaluated a method of right ventricular dimension measurements. Crystals were placed on the ventral and dorsal side of the right ventricular free wall, approximately one-fourth of the right ventricular semicircle away from the septum, in the middle of a cranio-caudal axis of the ventricles. The effects of an increased (infusion of 20 mL/kg of 5% glucose for 3 min into seven rabbits), as well as decreased preload (nitroglycerin, 5 micrograms/kg/min i.v. n = 6) were measured and compared with changes during a placebo infusion (n = 6). The change in shortening of the right ventricle wall segment correlated with changes in both atrial natriuretic factor (ANF) plasma concentration (r = 0.89, p < 0.05) and central venous pressure (CVP) (r = 0.94, p < 0.05), respectively. Both these variables are influenced by right ventricular function and dimensions in healthy animals. Dimension measurements obtained across the free wall of the right ventricle appear to reflect right ventricular function well and should be useful in assessing the effects of drugs intended for the treatment of angina pectoris or heart failure.

Animals↗
PubMed1992

Effect of spirapril on left ventricular hypertrophy due to volume overload in rats.

The effect of the angiotensin-converting enzyme (ACE) inhibitor spirapril on structural and functional parameters of volume-overloaded rat hearts was evaluated in a time-course study. Left ventricular hypertrophy (LVH) was induced by graded disruption of the aortic valve in male Wistar rats. Four weeks later, structural (LV mass and LV wall thickness) as well as functional parameters [LV end-systolic and end-diastolic volumes, stroke volume (SV), ejection fraction (EF)] were determined in anesthetized animals by magnetic resonance imaging (MRI). The rats were then divided into two groups, one of them receiving spirapril (10 mg/kg/day) in food. LV parameters were evaluated by MRI at 4, 18, 25, and 32 days after treatment was started. MRI analysis before the start of treatment showed that both groups had developed a similar degree of eccentric LV hypertrophy. Similarly, LV wall thickness, end-systolic and end-diastolic volumes, SV, and EF did not differ between the groups. Treatment with spirapril resulted in stable LV weight during the follow-up period of 32 days, whereas the untreated group showed a significant steady increase in heart weight. LV end-diastolic volume, LV end-systolic volume, and SV were smaller in the spirapril group when measured after 25 and 32 days, but only the difference in end-diastolic volume reached statistical significance. LV wall thickness and EF were not affected by spirapril. After the last MRI determinations, blood pressure (BP) and the response to angiotensin I (ANGI) were measured in conscious animals. Systolic BP (SBP) and mean arterial pressure (MAP) were significantly lower in spirapril-treated rats, and the dose-response curve to ANGI was shifted to the right.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

Autonomic nervous system dysfunction alters drug effects: implications for testing drugs for the treatment of heart failure.

Blunted cardiac responses to sympathetic and vagal activation are key features of heart failure. Since the modulation of drug effects by a selective autonomic dysfunction is little known, we developed an acute rabbit model imitating these defects. Anesthetized rabbits were subject to cervical vagotomy and propranolol (1 mg/kg i.v.) pretreatment, thus eliminating vagally and sympathetically mediated cardiac responses, while maintaining the responsiveness of the peripheral circulation to these reflexes ("V-B" animals). Responses to drugs were altered in V-B compared with normal animals: Ouabain (5-50 micrograms/kg) increased myocardial contractile force more and milrinone (30-300 micrograms/kg) less, yet it increased the heart rate more; the reflex tachycardia to nitroprusside (1-10 micrograms/kg/min) was blunted and spirapril (0.1 and 1 mg/kg, all i.v.) decreased the central venous pressure only in V-B animals. Several drug effects were thus strongly modulated by autonomic dysfunction and responses of V-B animals were closer to those of heart failure patients than the responses of the normal animals, especially for milrinone.

Animals↗
PubMedDate not supplied

[A computer program for the interpretation of the acid-base status and respiratory gases].

A computer program for analysing the parameters of the acid-base status and respiratory gases has been designed. The program separates cases which are included into classical picture of certain respiratory, metabolic and mixed disorders. Out of a test series of 200 findings, 93% findings have been accurately interpreted. The program is written in BASIC, translated into machine code and occupies about 25 Kbyte computer memory. The main parts of the program use commands which do not favorize any version of BASIC increasing the program portability to other systems. The classification of respiratory gases and acid-base status was based on the already known facts.

Acid-Base Equilibrium↗