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Biomedical subjects

D Boişteanu

Publications and source records attributed to D Boişteanu.

14 recordsLinked to original sources
PubMedDate not supplied

[Nitric oxide and bronchopulmonary reactivity].

After a brief review concerning NO biosynthesis, distribution and actions, its main normal and pathological implications are presented. The NO modulatory role on the bronchiolar and vascular smooth muscle basal tone, as well as its involvement in local inflammatory reactions are shown. Physiopathological broncho-pulmonary NO implications are completed with data concerning its inhalatory use in the treatment of pulmonary arterial hypertension, acute respiratory distress syndrome and severe pneumonia.

Animals↗
PubMedDate not supplied

[Dipsogenic behavior].

Hydroelectrolytic homeostasis assumes balance between the intake and elimination of water and electrolyte, according to the necessities of the organism. The water intake is made mainly by fluid ingestion. The necessity to drink is a subjective sensation which is the expression of an objective situation, because it translates the homeostatic deviations. The ingestion of water is motivated (reparatory thirst), when it appears after hydric and electrolytic imbalances (ex. a decrease of the fluid volume, increase in the plasmatic osmolarity) or is manifested without an objective reason (unreparatory thirst).

Animals↗
PubMedDate not supplied

Role of the epithelial derived factors on airway reactivity.

A tracheobronchial smooth muscle reactivity study on isolated guinea pig tracheal rings was done. The existence of two different factors active on the smooth muscle, an inhibiting one as well as an activating one were identified. Generated on different pathways, the epithelial derived relaxing factor is a cyclooxygenase dependent prostaglandin, while the activating epithelial factor seems to be a thromboxane derivative.

Airway Resistance↗
PubMedDate not supplied

[Experimental data on epithelial factors modulating bronchial reactivity].

A tracheobronchial smooth muscle reactivity study on isolated guinea pig tracheal rings was done. The presence of two different factors active on smooth muscle, an inhibiting one, as well as an activating one was identified. Generated on different pathways, the epithelial derived relaxing factor is a cyclooxygenase dependent prostaglandin, while the activating epithelial factor seems to be a thromboxane derivate.

Animals↗
PubMedDate not supplied

[Variations in plasma angiotensin-converting enzyme and renin in sarcoidosis].

A comparative study of plasma angiotensin-converting enzyme and renin activity was carried out in 55 patients with sarcoidosis and other pulmonary diseases. The converting enzyme activity was significantly increased in active sarcoidosis, showing a tendency to return to normal values after corticoid treatment, while plasma renin activity remained unaltered both before and after corticotherapy. The obtained results confirm the usefulness of the converting enzyme measurements, as already shown by others. Attention is drawn on the possible involvement of the pulmonary renin-angiotensin system in the local vascular and enzymo-chemical alterations, suggesting the possibility of associating the converting enzyme inhibitors to the corticotherapy of sarcoidosis.

Fluorometry↗
PubMedDate not supplied

[A comparative study of plasma converting enzyme and renin in sarcoidosis].

The paper reports on a comparative study of the conversion enzyme and plasmatic renin performed on a group of 55 patients, with clinical diagnosis of sarcoidosis and other lung diseases. Whereas the conversion enzyme showed important increases in active sarcoidosis and a tendency to the normal state after treatment with corticoids, the activity of the plasmatic renin remained the same, both before and after corticotherapy. The result obtained prove the practical usefulness of the dosage test of the conversion enzyme, in agreement with the literature data. They also point to the possible participation of the pulmonary SRA in the vascular and local enzymatic-chemical imbalances, suggesting the possibility of associating the conversion enzyme inhibitors to the treatment of sarcoidosis with corticoids.

Clinical Enzyme Tests↗
PubMedDate not supplied

[The effect of captopril on the coronary circulation in a clinical and experimental study].

Taking into account the well-known angiotensin II-induced coronary constriction, in a first series of experiments the effects of captopril were studied upon the rabbit, guinea pig and rat coronary circulation during perfusion with oxygenated Krebs-Henseleit solution at 37 degrees C under constant pressure and variable flow according to the Langendorf technique. The inhibition of angiotensin I to angiotensin II conversion enzyme with captopril (5-500 microgr./ml) resulted in a coronary dose dependent dilation as a consequence of a reduction in the basal coronary tonus. Testing the coronary distensibility by using pressure and flow variations revealed a significantly increased distensibility when the conversion enzyme was specifically blocked with captopril. The anginal threshold of the atrial electrostimulation was increased after captopril (25-50 mg i.v.) in 15 out of 18 patients with coronary insufficiency by a mean value of 17%, white the systolic dynamics was significantly better. The obtained results bring new arguments in favour of the intrinsic renin-angiotensin system participation in maintaining the basal vascular tonus and of the increased coronary distensibility in the presence of captopril as an inhibitor of the local synthesis of the vasoconstrictor angiotensin II.

Adult↗
PubMedDate not supplied

Cardiovascular effects of L-arginine as physiological precursor of nitric oxide.

In this study the cardiovascular effects of L-arginine were investigated. Perfusion with sorbitol L-arginine 5% solution induced a significant decrease of the systolic blood pressure in the human arterial hypertension. The hypotensive effects of L-arginine are accompanied by an increase of the ventricular ejection fraction. In vitro, L-arginine as physiologic precursor of nitric oxide induced a smooth muscle relaxation more evident in the coronary vessels than in the thoracic aorta rings. Selective inhibition of NO-synthetise with L-NAME reduced the L-arginine vasodilation and intensified the vasoconstrictor effect of phenylephrine.

Amino Acid Oxidoreductases↗
PubMedDate not supplied

[The oxygen paradox].

Even essential for the aerobic organisms survive and cellular respiration through the redox energogen reaction, the oxygen seems to be not only a "life support" but also a start point for a type of tissular injuries recognized with the generic term of "oxidative stress". In fact, if the most part of the cellular oxygen is normally metabolized through a citochromoxidase enzyme, 2-5% of it escape from this bivalent reduction and choose the monovalent one, resulting in toxic free radicals. Their implication is well known in some physiological but also pathological processes. So, the last two decades data justify the idea that oxygen role is as complex as paradoxical.

Animals↗