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At least 19 recordsLinked to original sources
PubMed1978

Fine structure of the homologous tergo-coxal muscles of flying and flightless beetles.

The flight-related tergo-coxal muscles of flying and flightless beetles are compared. In the flying beetle, Pachynoda sinuata, the myofibrils and cylindrical and the myofilaments packed in double hexagonal arrays. The sarcomeres are short (2.8 micrometer) and wide with many large, closely packed adjacent mitochondria but the sarcoplasmic reticulum is poorly developed in this fibrillar (asynchronous) muscle. Sarcoplasmic glycogen in rosette form is abundant. In the flightless beetle, Anthia thoracica, the myofibrils are lamellar-like with sarcomeres of 5.3 micrometer. The myosin filaments form a single hexagonal array each thick filament having an orbital of 11 to 12 thin filaments. The width of the Z-line (120 nm) of A. thoracia muscle was twice that of the Z-line of P. sinuata muscle. The sarcoplasmic reticulum and T-system are well-developed in this afibrillar (synchronous) muscle. Few glycogen granules are present. Triangular projections of the sarcolemma occur regularly opposite the Z-lines in A. thoracica and they appear to extend into the Z-lines. Membranous connections joint adjacent Z-lines in A. thoracica and occasionally in P. sinuata.

Animals↗
PubMed1978

Growth and muscle protein turnover in the chick.

The growth rates of young chicks were varied from 0 to 10% per day by manipulation of the adequacy of the amino acid and energy supply. The rates of protein synthesis in the white breast (pectoralis thoracica) muscle and the dark leg (gastrocnemius and peronaeus longus) muscles were estimated by feeding l-[U-(14)C]tyrosine in amino acid/agar-gel diets (;dietary infusion'). This treatment rapidly and consistently produced an isotopic equilibrium in the expired CO(2) and in the free tyrosine of plasma and the muscles. Wholebody protein synthesis in 2-week-old chicks was estimated from the tyrosine flux and was 6.4g/day per 100g body wt. In 1-week-old chicks the rate of protein synthesis was more rapid in the breast muscles than in the leg muscles, but decreased until the rates were similar in 2-week-old birds. Synthesis was also more rapid in fast-growing Rock Cornish broilers than in medium-slow-growing New HampshirexSingle Comb White Leghorn chicks. No or barely significant decrease in the high rates of protein synthesis, in the protein/RNA ratio and in the activity of RNA for protein synthesis occurred in non- or slow-growing chicks fed on diets deficient in lysine, total nitrogen or energy. Thus the machinery of protein synthesis in the young chick seems to be relatively insensitive to dietary manipulation. In the leg muscles, there was a small but significant correlation between the fractional rate of growth and protein synthesis. A decrease in the fractional rate of degradation, however, appeared to account for much of the accumulation of muscle protein in rapidly growing birds. In addition, the rapid accumulation of breast-muscle protein in rapidly growing chicks appeared to be achieved almost entirely by a marked decrease in the fractional rate of degradation.

Age Factors↗
PubMed1976

Blood parasites of Taiwan birds.

Blood films were examined from 1477 birds of Taiwan (193 species, 49 families). Haemoproteus Kruse was by far the commonest parasite, with Leucocytozoon Danilewski a not very close second. it is probable that some of the Haemoproteus infections represented new species, and 1 occurring in the Bamboo Partridge (Bambusicola thoracica sonorivox Gould) seemed characteristic enough to justify recognition as such; the name Haemoproteus bambusicolae sp. n. is proposed for this organism. Malaria was found in 77 birds, the greatest number of infections occurring in the Bamboo Partridge. Most of them were caused by Plasmodium juxtanucleare Versiani & Gomes, a pathogen of chickens, but a number were due to an undetermined species of Plasmodium. The Bamboo Partridge may be a reservoir host of the former. A few other identified species (P. rouxi Sergent & Sergent, P. hexamerium Huff, P. tenue Laveran & Mesnil) were seen, as well as some unidentified ones. Plasmodium tenue was seen in Garrulax canorus taewanus Swinhoe, a babbler: until now it was known only from the Pekin Robin (Leiothrix luteus Scopoli), also a babbler, in which we have found it extremely common. Sixty-four microfilarial infections were identified; they were especially frequent in the Button Quail (Turnix suscitator rostrata Swinhoe).

Animals↗
PubMed1976

[Reactivity of isolated arteries from hypertensive rabbits].

Isolated vessels (aorta thoracica, a pulmonalis, a. femoralis, a. renalis) of neurogenous-interoceptive and nephrogenous hypertensive rabbits showed a changed sensitivity to several vasoactive agents. An increased reactivity to noradrenaline, histamine, and serotonin in the aorta of neurogenous hypertensive rabbits, in the a. pulmonalis of neurogenous and renal hypertensive rabbits and in the a. femoralis of renal hypertensive animals in comparison with controls could be shown. Also registered was a hyperactivity to BaCl2 and KCl. All vessels of hypertensive rabbits were hyporeactive to angiotensin. They increased vascular reactivity was seen already in the 3rd week after removal of one kideny and pressoric receptors respectively. It is supposed that a "true supersensitivity" of the vascular smooth muscle cells of the hypertensive arteries does exist.

Angiotensin II↗
PubMed1977

[Tensibility measurements on the rats aorta (author's transl)].

II. Elasticity Parameters in Various Ages Power-extension diagrams of longitudinal and transversal stripes of the Aorta thoracica were recorded by means of an elctro-mechanical measuring instrument. The samples were taken from 108 male Sprague-Dawley rats aged 9, 15 and 24 months. The following parameters describing age-dependent alterations were calculated from the hysteresis loops of three consecutive extension-relaxation cycles: 1. the maximum power 2. the area of the first hysteresis loop 3. the characteristic of the relaxation-part of the third cycle. The maximum power and partly the areas of the hysteresis loops increased with age. The curves obtained by longitudinal stripes were approximated to a linear function (y = a + bx) plus a power-function (y = cxd). Their constants were explained as indices to the plasticity of the aorta, the retraction-power of the elastic fibres, the degree of the spiralization of the collagen fibres and the amount and/or the stability of the collagen. The ageing changes of these parameters indicated an increase of plasticity, an increase in the retraction-power of the elastic fibres, a rise of the pitch of the collagen spiral and an increase in the amount and/or in the stability of collagen. The curves from the extension of the transversal stripes revealed a different extension characteristic and could be described as the sum of two power functions. The causes of this different behaviour are not yet clearly understood.

Age Factors↗
PubMedDate not supplied

[Vasomotor innervation of the arteries and veins of Rana temporaria frogs].

Adrenergic and cholinergic innervation of frog arteries and veins has been studied histochemically using glyoxilic acid and the method of Karnovsky--Roots. It was shown that the vessels studied differ in catecholamine-containing structures, the intensity of fluorescence of adrenergic nerve endings, the density of nervous plexus and the direction of nerve fibers. It was found that adrenergic innervation is present not only in the arteries, but in the veins as well. Morphometrical analysis indicates that the density of adrenergic plexus per volume unit of vascular wall in the veins investigated is higher than the density of adrenergic nerves in the arteries. This finding suggests that the nervous control of the veins appears in evolution beginning from amphibians, but not from reptiles. It was reliably demonstrated that aorta thoracica and pulmonary artery receive cholinergic innervation, the density of cholinergic plexus in the latter being twice higher than that of adrenergic one.

Abdomen↗
PubMed1978

A histological study of post mortem changes in the skeletal muscle of the fowl (Gallus domesticus). I. The muscle fibres.

The changes in the histology of skeletal muscle post mortem have been studied with the light and electron microscopes in the pectoralis thoracica and iliotibialis muscles of the fowl (Gallus domesticus). The carcasses were stored at 40 degrees C and samples removed at various times post mortem. Kinking, contractures, transverse splitting and disintegration were seen in muscle fibres from post mortem muscle. The variation in time and frequency of occurrence of these was wide but no consistent difference between the pectoralis and iliotibialis muscles was found. An attempt was made to integrate the results from the light and electron microscopes to gain insight into the nature of the modifications occurring in the histology of post mortem muscle fibres.

Animals↗
PubMed1978

A histological study of post mortem changes in the skeletal muscle of the fowl (Gallus domesticus). II. The cytoarchitecture.

Changes in the histology of skeletal muscle at an ultrastructural level have been studied in the pectoralis thoracica and iliotibialis muscles of the fowl (Gallus domesticus). The carcasses were stored at 40 degrees C and samples removed at various times post mortem. The Z discs and I bands degenerate rapidly (less than 4 hours) but the thick filaments of the A band are remarkably resistant to change (greater than 24 hours). The sarcolemma, mitochondria, glycogen content, sarcotubular system and myonuclei also show marked changes in less than 4 hours. Myelin figures and autophagic vacuoles are among other features seen in post mortem tissue. There are more degenerate mitochondria and vesicular remnants of the sarcotubular system in the iliotibialis than in the pectoralis muscle, but this reflects a differing concentration of these organelles in vivo. No other consistent difference in the post mortem histology of these muscles has been observed.

Animals↗
PubMed1977

[Wide-spread haemangioma racemosum of the mediastinum associated with paresis of the diaphragm; a finding to be considered in the differential diagnosis of the arteriovenous aneurysm of the thorax (author's transl)].

The paper reports on a 5 year old boy showing a sprawling haemangioma racemosum of the right side of the mediastinum. The vascular tumor is fed by a tortuous A. thoracica interna dextra and numerous arterial vessels arising from the right subclavian artery and from the aorta including the right coronary artery and branches from the abdominal aorta. The child presents also paresis of the right diaphragm probably secondary to the pressure of the pulsatile tumore along the course of the phrenic nerve. After ligation of three major feeding arteries the continuous murmur disappeared and fatigability and anorexia became less. Apart from this report a review of the literature on vascular malformations of the arterio-venous fistula type within the thorax sums up the most important features of these vascular anomalies: haemodynamics, localisation, clinical signs, therapy, natural history, therapy and etiology.

Arteriovenous Malformations↗
PubMed1976

The lateral photoreceptor of the barnacle, Balanus eburneus: quantitative morphology and fine structure.

The lateral eye of the barnacle, Balanus eburneus, fixed in highly concentrated osmium is a lens-shaped body of approximately 250 mum in diameter and about 75 mum thick. It contains three photoreceptor cells which occupy about 42% of its volume. The photoreceptor cells are irregularly shaped and extend countless dendritic processes which bear rhabdomeres at their ends. Individual rhabdomeres come into contact with rhabdomeres originating from dendrites of the same or of one of the other visual cells. Thirteen per cent of the volume of the photoreceptor cells is taken up by the rhabdomeres. The membranes of the rhabdomeric microvilli contain globular subunits which suggest a 70 A spacing of rhodopsin molecules. There are two kinds of glial cells. One kind, type A glial cells, makes contact with the fibrous capsule of the photoreceptor. The other kind, type B glial cells, is associated with the photoreceptor cells and extends countless tiny cytoplasmic extensions which interdigitate with similar extensions of the receptor cells. There are approximately 95 type B glial cells and 130 type A glial cells in the receptor. The cytoplasm of the photoreceptor cells contains countless small Golgi fields, mitochondria, microtubules, multivesicular and multilamellar bodies. The extracellular space of the photoreceptor is less than 0.1% of its total volume.

Animals↗
PubMed1975

Effects of pH and ionic strength on the potassium system in the internally perfused giant barnacle muscle fibre.

Membrane potentials in single barnacle muscle fibres of Megabalanus psittacus, internally perfused with 200 mM K-acetate (KAc) solution of pH 7.5 were in the range --53 to --60 mV. These were followed as a function of pH of the external chloride saline. Decrease of pH of the Cl-saline from 8.5 to 3.5 hyperpolarized the membrane reversibly by about 8 mV. On further decrease of pH to 3.0, a transient hyperpolarization (from --60 to --65 mV) followed by a sudden and irreversible drop of potential to --40 mV was observed. Replacement of the external Cl-saline by acetate saline in the pH range 8.5 to 6.5 had no effect on the membrane potential. Further decrease of pH to 5.0 brought about an irreversible reduction of membrane potential. For fibres bathing in Cl- or Ac-saline at pH 7.5 when the internal pH was changed to 5.5, a transient hyperpolarization in Cl-saline and a sustained hyperpolarization in Ac-saline were observed. Further studies of membrane potential changing the concentration of external K, keeping the concentration of Cl or Ac constant, and changing the concentration of Cl or Ac, keeping the concentration of K constant, at different internal and external pHs showed that as the pH was reduced the membrane became more permeable to anions, Cl being more permeable than Ac. Experiments in which the membrane potential was controlled showed that when the internal pH of 200 mM KAc solution was reduced from 7.5 to 6.5 or raised to 8.5, the changes in outward K currents at various depolarizations were negligible. However, when the pH was reduced to 5.5 or 5.0, there was a progressive decrease in the outward K currents. The leakage currents in all these cases were relatively small. Use of high ionic strength solution of 580 mM KAc internally protected the K system in that when the pH was lowered the depression of the outward K current was smaller than that observed at a corresponding pH when the internal solution was 200 mM KAc. Use of low ionic strength solution of 50 mM KAc had the opposite effect. The results have been explained in terms of the ion exchange theory by postulating that the membrane has fixed amphoteric groups.

Acetates↗
PubMed1976

Localization of calcium binding sites associated with the calcium spike in barnacle muscle.

La ion behaves as a competitive inhibitor of Ca ions on the calcium spike in the giant muscle fiber of the barnacle, Balanus nubilus. La-treated muscle fibers, in which the rate of rise of the spike was diminished to a known degree, have been examined with the electron-microscope. In such fibers dense particles are seen in association with the surface membrane and external lamina of the cell. La particles are not seen in association with fibers that have been allowed to recover from La inhibition before fixation. The number of La particles seen in association with the muscle fiber increases with increasing La concentration when the Ca and Mg concentrations are held constant and decreases with increasing Ca and Mg concentration when the La concentration is held constant. The results suggest that the La visible in the electron-microscope under the conditions of these experiments is bound to a class of sites similar to those involved in the Ca spike.

Animals↗