Biomedical subjects

G Viscor

Publications and source records attributed to G Viscor.

24 records · Page 2Linked to original sources

PubMed1987

Relationships between morphological parameters in birds with different flying habits.

1. Data on morphological and physiological parameters from 346 species of birds were collected from diverse sources. 2. The observed relationships among some pairs of variables showed differences between the five flight styles into which the studied birds were classified. 3. The characteristic kind of flight for each species is related to four easily obtainable non-invasive parameters: body weight (BW), wing area (WA), wing span (WS) and boyd length (BL). 4. Wing-loading index (BW2/3/WA) gives the most effective variable to describe the flying habits of any species.

Animals↗

PubMed1987

On the preservation of avian blood cells.

The functional state of erythrocytes from hen during their conservation with a preserving solution for 24 days at 4 degrees C, has been estimated by studying some biochemical and hemorheological parameters. Results show an initial phase in the preservation period (4-5 days) in which red blood cells maintain their values at levels similar to those at the beginning of the experience, except for osmotic resistance. Furthermore a progressive erythrocyte deformability loss, linked to ATP depletion (with rise in inorganic phosphate levels) as well as a gradually higher rate of hemolysis, were detected.

Adenosine Triphosphate↗

PubMed1985

Cardiovascular and organ weight adaptations as related to flight activity in birds.

Pectoral muscle, heart and body weight, wing surface, blood volume, hemoglobin content and blood oxygen capacity were measured in three birds: pigeon, gull and hen. A relationship was found between flying activity and organ weight, blood volume and hematocrit. No significant differences were found in the O2 carrying capacity of hemoglobin in these birds.

Adaptation, Physiological↗

PubMed1982

Method of determining the osmotic fragility curves of erythrocytes in birds.

The osmotic fragility of erythrocytes in 3 species of birds (Gallus gallus domesticus, Coturnix coturnix japonica, Columba livia) and the rat was determined. The results of this study point to a smaller osmotic fragility. Birds, with elliptical erythrocytes, have a lower osmotic fragility than species with round erythrocytes, like most of the mammals.

Animals↗

PubMedDate not supplied

Capillarity and fibre types in locomotory muscles of wild yellow-legged gulls (Larus cachinnans).

This study analyzes the capillarity and fibre-type distribution of six locomotory muscles of gulls. The morphological basis and the oxygen supply characteristics of the skeletal muscle of a species with a marked pattern of gliding flight are established, thus contributing to a better understanding of the physiology of a kind of flight with low energetic requirements. The four wing muscles studied (scapulotriceps, pectoralis, scapulohumeralis, and extensor metacarpi) exhibited higher percentages of fast oxidative glycolytic fibres (>70%) and lower percentages of slow oxidative fibres (<16%) than the muscles involved in nonflight locomotion (gastrocnemius and iliotibialis). Capillary densities ranged from 816 to 1,233 capillaries mm(-2), having the highest value in the pectoralis. In this muscle, the fast oxidative glycolytic fibres had moderate staining for succinate dehydrogenase and relatively large fibre sizes, as deduced from the low fibre densities (589-665 fibres mm(-2)). All these findings are seen as an adaptive response for gliding, when the wing is held outstretched by isometric contractions. The leg muscles studied included a considerable population of slow oxidative fibres (>14% in many regions), which suggests that they are adapted to postural activities. Regional variations in the relative distributions of fibre types in muscle gastrocnemius may reflect different functional demands placed on this muscle during terrestrial and aquatic locomotion. The predominance of oxidative fibres and capillary densities under 1,000 capillaries mm(-2) in leg muscles is probably a consequence of an adaptation for slow swimming and maintenance of the posture on land rather than for other locomotory capabilities, such as endurance or sprint activities.

Animals↗

PubMedDate not supplied

Hematologic and plasma chemistry values in captive psittacine birds.

Reference values for some hematologic parameters in 19 species and plasma chemical values in 11 species of Psittacine birds, including cockatoos, parrots, amazons, macaws, conures, and lories, were established for use in veterinary medicine. The following parameters were studied: hematocrit, hemoglobin concentration, erythrocyte number, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, erythrocyte dimensions, leukocyte number and differential leukocyte count, glucose, urea, uric acid, cholesterol, triglycerides, creatinine, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine phosphokinase, lactic dehydrogenase, gamma glutamyl transpeptidase, total plasma protein, albumin, globulins, albumin-globulin ratio, sodium, potassium, calcium, magnesium, total phosphorus, chloride, and osmolality. Hematologically, the Psittacine is a very homogeneous avian group, with small differences between species. They are, however, different from other groups of birds.

Animals↗