Comparative histometric study in the aortic arch of birds.

A histometric method was here adopted to study the concentration of elastic and collagenous fibers, muscle cells and cellular population of the mesarteria of the middle portion of the aortic arch of several species of birds were studied. The statistical analysis consist of the F test followed by Snedecor 's contrast test. The results obtained show that the concentration decrease on the sequential order of: fibers elastic, muscle cells and collagenous fibers in the goose, duck, black-culture and turkey, while in the peking duck the collagenous fibers were in more amount the muscular tissue, but not exceed the elastic fibers. From the variations pointed out here for the differents elements studied, only those of the muscular tissue have demonstrated a relative statistical signification.

Postnatal growth of skeletal muscle fibres of the rat.

Cross sectional area [micron] of Red, Intermediate, and White fibres of M. extensor carpi radialis longus of Wistar rats at frequent age intervals were measured and then calculated the growth equations, the growth rate equations, the growth rates, and the asymptotes of each kind of fibre. Muscled fibres of 12 d old rats were round in shape, presenting a somewhat uniform SDH activity. By 23 d and thereafter, muscle fibres were polygonal in shape, with different degree of enzyme activity and cross sectional areas. There was a close relationship between cross sectional area and in age. Individual fibres revealed distinct growth curves. The higher growth rates were observed at 23 and 45 d. After this ages, a markedly fall in growth rates for the 3 kind of fibres were observed. Growth rates of White fibres were higher than that of Red and Intermediate fibres.

Fine structure of the epidermal cuticle of some Brazilian earthworms (Oligochaeta: Annelida).

Electron microscopic techniques were adopted to study the epidermal cuticle of 4 species of brazilian earthworms. Basically this structure consists of collagenous fibers arranged in alternate layers and embedded in an amorphous and fibrillar matrix. Of characteristics, the ellipsoidal projections of the cuticle of P. hawayana were found to be enclosed between 2 parallel layers, where each layer consists of 2 electron dense lines, separated by a space filled with an electron dense material.

On the cross sectional area of skeletal muscle fibres of the rat.

Serial cryostat sections of M. gracilis (pars caudalis) were stained to demonstrate succinic dehydrogenase activity and then used to study the cross sectional area along the length of each category of muscle fibre. The results indicated that the mean area showed no appreciable variation. This finding support the evidence that the cross sectional area is the same along the course of a muscle fibre. Some sources of variation were also discussed.

Postnatal growth of fibres on M. gracilis (pars caudalis) in both sexes of rat.

Measurements of cross sectional area on individual fibres of M. gracilis (pars caudalis) of Wistar rats of both sexes in different ages were done. Growth equations pattern and growth rates equations pattern of each muscle fibre type were also determined. In rats 12 d old, muscle fibres present a somewhat uniform SDH activity. By 23 d and thereafter, SDH technique revealed a mixed population of red, intermediate and white fibres. There was a close relationship between cross sectional area and age, where each fibre type presents a distinct exponential growth curve pattern. The highest growth rates were observed at 23 and 45 d. After this age, a markedly fall in growth rates occurs, except for white fibres, where this decrease was less intense. Red and intermediate muscle fibres tend to estabilize their growth earlier than white fibres.

Fibre types of M. pectineus of the cat (Felis domestica).

As revealed by the NADH-diaphorase, SDH and myosin ATPase, the M. pectineus of the cat possesses at least 3 main kind of fibres, with different distribution on the superficial and deep portions of the muscle. The superficial portion revealed that 23.6% are FOG fibres: 17.8% are SO fibres and 58.6% are FG fibres. Already the deep portion revealed that 61.4% are FOG fibres: 14.5% are SO fibres and 24.1% are FG fibres. The myosin ATPase reaction was used to demonstrate contracting characteristics. These findings suggest that the movements of fast contraction of M. pectineus are predominant.

Anatomical aspects of the lacrimal gland of the tufted capuchin (Cebus apella).

In the tufted capuchin (Cebus apella) the main lacrimal gland is composed of 2 distinct portions with an intraorbital and extraorbital localisation, interconnected by a bridge of glandular tissue which crosses the lateral orbital wall through the lateral orbital fissure located in the sphenozygomatic suture. The intraorbital lacrimal gland is flattened and extremely thin, with a variable outline. It lies on the upper and outer third of the globe of the eye, and the aponeurosis and the belly of the lateral rectus muscle, extending antero-posteriorly from the upper lateral angle of the orbit midway along the orbital cavity. The extraorbital lacrimal gland is compact, halfmoon-shaped, with 3 surfaces, 3 borders and 2 extremities. It lies in the temporal fossa between the temporalis muscle and the temporal surface of the zygomatic bone, fitting into a depression in this bone, and totally surrounded by adipose tissue. The secretory cells have a flocculent appearance and either low or high density. They possess a basal region containing the nucleus and rich in granular endoplasmic reticulum, and an apical region filled with secretory granules varying in size, form and density.

On the microscopic anatomy of periadventitial tissue of Cisterna chyli and Ductus thoracicus of the cat (Felix domestica).

Anatomical and histological techniques were adopted to study the structure of periadventitial tissue of Cisterna chyli and Ductus thoracicus of the cat. Basically this tissue is represented by a loose connective tissue, presenting a relatively large amount of unilocular adipocytes. Inside the periadventitial tissue there is a predominantly collagenous membrane and it seems to link the cisterna chyli and the ductus thoracicus to the adventitia of the Aorta.

Histochemical study of mucopolysaccharides in epidermal mucous cells and subjacent granular cells of Glossoscolex uruguayensis L. (Righi, 1978).

Histochemical study of mucopolysaccharides of both mucous secreting and subjacent granular cells of the epidermis of Glossoscolex uruguayensis L (Righi, 1978), has been done. Histochemical tests revealed two major types of mucous cells: large ortochromatic mucous cells and metachromatic mucous cells. The first ones possess alpha-amylase resistant, PAS-positive material, together with little mucic acid, and the latter present a very low rate of neutral mucopolysaccharides and to a variable degree, both carboxylate and sulphate mucopolysaccharides. A third cell type was also detected, presenting a frothy acid like material. Subjacent epidermal granular cells display alpha-amylase resistant, PAS-positive granules, with no acid mucus.