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Biomedical subjects

P Groza

Publications and source records attributed to P Groza.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Changes in some digestive enzymes after a seven-day orbital flight.

Changes in some digestive enzymes (amylase, lipase, uropepsinogen) were studied in the serum and urine of one of the participants in the Soviet-Romanian seven-day space flight on the Soyuz 40-Saliut 6 complex. On the first day after landing it was found an increased total serum and urinary amylase, resulting from the separate increase of pancreatic and salivary amylase, determined by Skude and Ihse's method [14]. In both serum and urine, pancreatic amylase was found in higher amounts than the salivary one. Lipase was also increased. These modifications are in general in keeping with those recorded after different flights of similar duration and are part of the anabolic response. The pancreatic and salivary amylase were first investigated separately. Under the same conditions uropepsinogen was decreased, an unexpected result. Serum gastrin was increased, in agreement with a generally increased digestive activity.

Adult↗
PubMedDate not supplied

Modifications of the digestive tract in rats submitted to an orbital flight aboard the Soviet satellite Cosmos 1129.

Investigations carried out on the digestive tract of rats submitted to an 18 1/2-day orbital flight aboard the Soviet biosatellite Cosmos 1129 revealed that flight produces a reduction of the glycoproteins (GP) of the submaxillary glands, gastric mucosa and the goblet cells of the small and large intestine, the last being the most nonreactive, as well as an augmented staining for leucine-aminopeptidase (LAP) and acid phosphatase (AP). In lamina propria an accumulation of eosinophils was noticed. These changes were more intense than those produced in the groups of rats maintained "synchronous" under environmental conditions similar to flight. On the basis of previous data obtained by various authors and by ourselves on hypokinetic rats from the biosatellite Cosmos 936, it can be concluded that these reactions have a nonspecific, stress character. A stress of restraint applied daily for 2 1/2 hours during a period of 6 days to the animals immediately after landing produced modifications similar to those following flight but more intense, thus underlying the hypothesis of a stress reaction.

Acid Phosphatase↗
PubMedDate not supplied

Systolic time intervals after a seven-day orbital flight.

Heart rate (HR), systolic time intervals (STI) (pre-ejection period--PEP, left ventricular ejection time--LVET, PEP/LVET ratio indirect ejection fraction--EF, stroke volume--SV and QT interval of two cosmonauts (Leonid Popov--LP and Dumitru Prunariu--DP), were studied before, during and after an ergometric bicyle exercise test performed before and after the seven-day Soviet-Romanian orbital flight on the Soyuz 40--Saliut 6 Complex in May 1981. To this purpose one precordial electrocardiogram (Ecg) and the ear densitogram (Den) were recorded simultaneously. The method used permitted clear recordings even during exercise. Ecg and Den signals were stored on magnetic tape, processed in an analogue device and in a digital computer. The data obtained after landing suggest a slight cardiac deconditioning in LP, demonstrated especially by PEP augmentation, which was unchanged in DP corresponding to a better cardiac contractility. It is concluded that the seven-day orbital flight has not produced important cardiovascular alteration.

Adult↗
PubMedDate not supplied

Systolic time intervals in passive head down position (-85 degrees) and exercise.

Variations of cardiac time intervals (CTI) in head-down (HD) condition and during an 120 watts bicycle exercise were investigated by the method of ear densitogram associated with an automatic system of evaluation of systolic time intervals (STI), in young subjects, aged 25-30 years. In the HD experiment unchanged heart rate (HR) and left ventricular ejection time (LVET) values were increased, whereas pre-ejection time (PEP) values decreased. Exercise increased HR and decreased PEP and LVET values. Two different mechanisms are involved in the decrease of PEP in the two circumstances, by increasing the end diastolic volume and, respectively, by a sympatho-adrenergic reaction.

Adult↗
PubMedDate not supplied

Small intestine biopotentials in rats after hypokinesia.

In order to study the effect of hypokinesia on rats' small intestine biopotentials it was first necessary to characterize it. Biopotentials were recorded by intracellulary microelectrodes from oral and caudal segments of the small intestine. The morphology of rat's small intestine biopotentials differs from that of other species (man, cat, rabbit, dog, e.a.) the slow waves being smaller and the frequency of basal electrical rhythm higher (approximately 31.23 c/min oraly and approximately 24.50 aboraly), and by waxing and waning waves that are more frequently encountered suggesting a greater number of plateaus potentials. Spike potentials are inscribed on the descending slope of the slow waves but delayed in each successive wave with a regular interval. Hypokinesia obtained by introducing rats in small cages for two weeks, increases the slow waves amplitude. Frequency of basic electric rhythm and other parameters are not specifically changed.

Action Potentials↗