Search PubMed⌕ Search

Biomedical subjects

N Hugo

Publications and source records attributed to N Hugo.

At least 55 records · Page 3Linked to original sources
PubMed1988

Comparison of blood flow parameters measured by Doppler ultrasound and radionuclide techniques in the baboon (Papio ursinus).

Ascending aortic blood velocity was measured in the baboon (Papio ursinus) by using continuous wave Doppler ultrasound. The blood flow parameters thus obtained were compared to those by the standardized radionuclide technique. It appears that, due to the anatomical position of the ascending aorta and brachiocephalic trunks in relation to the ultrasound beam, Doppler ultrasound does not provide an accurate method of measuring aortic blood velocity in the baboon, which could be the reason for the poor correlation of the results from the two techniques.

Animals↗
PubMed1988

Scintigraphic phase analysis of abnormal A-V conduction in a baboon.

During an interventional cardiac investigation on an anaesthetised baboon (Papio ursinus) the animal developed A-V block. Scintigraphic phase analysis leading to quantified intraventricular delays and histogram characteristics pointed to abnormalities which persisted even after A-V block was replaced by nodal tachycardia as was reflected by the electrocardiogram. This indicated towards an increased diagnostic sensitivity with the use of phase analytical methods.

Animals↗
PubMed1988

A positive wave at the J-point of electrocardiograms of anaesthetized baboons (Papio ursinus).

Electrocardiograms were performed on 50 anaesthetized baboons (Papio ursinus). A positive deflection, referred to by us as the H-wave, consistently occurs at the junction between the QRS complex and the S-T segment. The significance of this deflection at the J-point, as the junction is known, is still to be established; however, characterization of the H-wave regarding amplitude and position with respect to the R-wave is done.

Animals↗
PubMed1987

Phase mapping from left ventricular radionuclide ventriculograms: interobserver reliability and accuracy of the programme.

Phase analysis of data from radionuclide ventriculograms is known to provide space-time information on the mechanical emptying of pixels located in the ventricular regions. It could therefore perhaps be useful for detecting abnormal sequences of contraction of the ventricles as well as to localize sites of premature electromechanical action. The phase programme used in this investigation is designed to trace the electromechanical action of the ventricles from colour-coded phase images (first harmonic Fourier transform), not only visually from a cinematic representation, but particularly from a data output of x, y coordinates and phase angles of sites chosen as they empty in the ventricular regions. Six healthy baboons were subjected to conventional radionuclide ventriculography, performed hourly for the duration of 11 h under anaesthesia. The programme was used by two independent observers to map the progression of emptying for each of the thus acquired 66 left ventricular phase images. The interobserver reliability and the accuracy achieved in mapping normal contraction patterns was found to be good. Abnormalities which appeared during the prolonged anaesthesia and which were confirmed with 12 lead electrocardiography were likewise detected consistently.

Animals↗
PubMed1987

The sensitivity of radionuclide and thermodilution techniques to detect cardiac dysfunction in the baboon model during prolonged anaesthesia.

This study was undertaken to evaluate the fluctuations of cardiac parameters in a baboon model during pentobarbitone anaesthesia which will serve as a baseline control for shock studies. Thermodilution and radionuclide methods were used to determine cardiac parameters. Radionuclide studies were repeated without any cardiac catheters to assess the effect of these on cardiac performance. The results represent baseline fluctuations in cardiac parameters against which cardiac dysfunction can be diagnosed in shock studies. The results also indicate that cardiac catheterisation does not affect cardiac performance significantly.

Anesthesia, Intravenous↗
PubMed1987

Comparative radionuclide and thermodilution determinations of cardiac output and stroke volume in the baboon (Papio ursinus).

Thermodilution cardiac output determinations and multigated equilibrium blood-pool scintigraphy were performed in ten healthy chacma baboons (Papio ursinus). The correlation was moderately good between both the radionuclide and thermodilution stroke volume (r = 0.58, SEE = 3 ml; SVth = 0.78SVr + 15.6 ml) as well as the cardiac output (r = 0.72, SEE = 0.2 liter/min; COth = 0.56 Cor + 2.1 liter/min). The attenuation depth dr as determined by radionuclide techniques was found to correlate well with the radiologically determined values dx (r = 0.8, SEE = 0.4 cm; dx = 0.87dr + 0.72 cm) which validated the depth values used in the calculations.

Animals↗
PubMed1982

A modified neutral sucrose centrifugation method for rapid detection of DNA damaged by gamma-radiation and repair in human lymphocytes.

1. The influence of 60Co gamma-radiation on the sedimentation behaviour of human lymphocyte nucleoids in neutral sucrose gradients was studied with the aid of a modified fluorescent monitor system consisting of the DNA-binding dye, Hoechst 33258 and a vertical centrifuge rotor. 2. A combined method employing the sedimentation procedure and the incorporation of tritiated nucleosides was utilized to evaluate the repair of gamma-radiated DNA.

Centrifugation, Density Gradient↗
PubMed1980

The ultrastructure of epithelioid cells in the avian (Gallus domesticus) carotid body.

10 clinically healthy white leghorn males were utilised for this investigation. Apart from toluidine blue-pyronin-stained Araldite sections, uranyl acetate and lead monoxide staining revealed three types of epithelioid cells. Nuclear and cytoplasmic contents, especially three types of granules, conveniently designated as q, r and p granules, are described in detail and tabulated. Technical difficulties in obtaining carotid body tissue as well as clear-stained sections for ultastructural studies are mentioned.

Animals↗
PubMed1979

A possible causal relationship between defective fibrinolysis and pulmonary hypertension.

Pulmonary hypertension may be associated with multiple thrombi in the pulmonary arteries or with diffuse microembolization from a cryptic source. A 27-year-old man without any of the recognized clinical risk factors for venous thrombo-embolic disease presented with repeated attacks of chest pain and dyspnoea. Haemodynamic studies were compatible with the diagnosis of primary pulmonary hypertension. Despite intensive study there was no evidence of peripheral venous thrombosis. A survey of the plasma fibrinolytic profile showed unequivocal evidence of low spontaneous plasma fibrinolytic activity. The plasminogen activator activity of the venous wall was also markedly reduced. From these findings it would seem that a defective fibrinolytic defence mechanism may be an important predisposing factor in the pathogenesis of 'primary' pulmonary hypertension.

Adult↗
PubMed1978

Histocytology of the avian (Gallus domesticus) carotid body.

The histotopography of the silvery-white glistening carotid body and the branchial derivates in the cranial thoracic inlets as well as the histocytology of the particular organ were revealed by various microtechniques. Three types of randomly distributed epithelioid cells, many capillaries, and small and large sinuses are observable. Myelinated fibres are sparsely distributed. 25 clinically healthy white leghorn males were used for this investigation.

Animals↗