Neuroendocrine epithelial cells in the broncho-parabronchial transition of embryonic, immature and mature quail (Coturnix coturnix).

The main objective of this integrated light microscopic, transmission and scanning electron microscopic study was to describe in greater detail the structural pattern and developmental stages of pulmonary neuroendocrine epithelial cells (PNECs) in the broncho-parabronchial transition (BPT) of both developing and mature quail. In mature quail the BPT appeared as a diaphragm opening into the parabronchial vestibulum. Perpendicular sections revealed two bilayered crest-like entrance folds invested by a uniform population of granular cells with lamellar bodies and a brush border of blunt microvilli.

Lamellar inclusions and trilaminar substance in the parabronchial epithelium of the quail (Coturnix coturnix).

The fine structure of the epithelial cells of the parabronchus and their secretory products have been the subject of many studies and have given rise to considerable controversy about their configuration and ultrastructure. The aim of the present study was to investigate the mode of formation and discharge of lamellar bodies of granular cells and the trilaminar substance produced and discharged by the embryologically related squamous atrial and respiratory epithelial cells. The material for light and transmission electron microscopic analysis was collected from 10 mature quail and 3 individuals aged 2 days.

A scanning and transmission electron microscopy study of the parabronchial unit in quail (Coturnix coturnix) and town pigeons (Columba livia).

A combined scanning electron (SEM) and transmission electron microscopy (TEM) investigation was undertaken to gain insight into the complex structural pattern of the atrial compartment and the gas exchange tissue of parabronchial units in quail and town pigeons. The aim was also to depict the changes taking place in the parabronchial unit in the late prehatching and early posthatching periods in quail. The standard SEM and TEM investigation was carried out in 13 mature quail and 8 town pigeons.

The development and differentiation of the parabronchial unit in quail (Coturnix coturnix).

The present study has been inspired by the conflicting data in the relevant literature concerning the embryogenesis of cell types of the parabronchial epithelium and the formation, discharge and distribution of trilaminar substance and lamellar bodies. Lung tissue from embryonic, newly hatched, immature and mature quail was subjected to standard processing for light and transmission electron microscopy. The parabronchial rudiments form shallow primitive atria on embryonic day 13.

An SEM and TEM study of the transition of the bronchus to the parabronchus in quail (Coturnix coturnix).

The main objective was to analyse the transition of the bronchus to the parabronchus in birds and to describe its specific structure in an integrated light microscopic, transmission electron microscopic (TEM) and scanning electron microscopic (SEM) study. Lung tissue from immature and mature quail was subjected to standard processing for paraffin light microscopy, TEM and SEM after intratracheal inflation with fixative. In transverse paraffin and Durcupan semithin sections, the partition incompletely closing the broncho-parabronchial transition has the appearance of a crest-like fold delineating the entrance to the underlying parabronchial vestibulum.

Lymphatics in the lung of a precocial bird before and after hatching.

A light and electron microscopic study of pulmonary lymphatics was carried out in quail embryos (embryonic day; ED 13-17), completed with samples of lungs of quail 90 min, 24 h after hatching and two 2-day-old and three adult quail. The aim of the study was to depict the morphology of pulmonary lymphatics by determining the dynamics in ontogeny and to establish the rules of their distribution. The primitive lymphatics appear on ED 13 and 14 as closed thin-walled tubes in abundant interparabronchial mesenchyme.

An electron microscopic study of the parabronchial epithelium in the mature lung of four bird species.

Background: No integrated comprehensive description of the ultrastructure of the parabronchial epithelium is available. The origin, discharge, and occurrence of the trilaminar substance have not yet been sufficiently studied. Therefore, the main objectives were to classify the cell types of the parabronchial epithelium and to describe their role in manufacturing the trilaminar substance.

Anchoring and support system of pulmonary gas-exchange tissue in four bird species.

Avian air capillaries are delicate structures compared to the mammalian pulmonary alveolus. A transmission and scanning electron microscopic study was carried out on several species of birds with the aim of determining the support structures of the avian gas-exchange mantle. Lung tissue of two bird species belonging to strong flying birds (pigeon and barn owl) and two relatively flightless species (domestic fowl and quail) was subjected to standard processing for transmission and scanning electron microscopy after intratracheal inflation.

Pulmonary macrophages in birds (barn owl, Tyto tyto alba), domestic fowl (Gallus gallus f. domestica), quail (Coturnix coturnix), and pigeons (Columbia livia).

Background: Birds have a limited number of resident macrophages in the normal steady-state respiratory tract. The discovery of phagocytes in lavages of lung from birds contrasts with findings that phagocytes are seldom seen in investigations in situ. An electron microscopic study was performed in the respiratory units, the parabronchi, and air capillaries in particular in several adult bird species to localize the seat of respiratory macrophages.

[Early changes in the structure of venous grafts, their prevention and significance].

The authors investigated, using optic and electron microscopy, the course of regressive changes in smooth muscle cells of the media in venous grafts, in relation to various physical and chemical factors. They recorded the influence of a temperature of 4 degrees C and 22 degrees C, the influence of various types of crystalloid and colloid solutions and some pharmaceutical preparations. In previous work they found that, as a result of ischaemia, regressive changes take place in the smooth muscle cells of the media, while plasmatic structures of these cells and fibrillar structures of the venous wall remain intact.

[Early changes in the structure of vein grafts and their significance in the development of complications after revascularization surgery].

By means of light and electron microscopy the development of regressive changes in the media of vascular graft were studied. The authors found out that as a result of warm and cold ischaemia to which the vascular graft is exposed before implantation changes in nuclei of smooth muscle cells arise. The development of these changes can be postponed by keeping the graft in a suitable medium before implantation.

[Fine morphology of the lymphatics and tissue spaces in the liver parenchyma in man and its significance in hepatobiliary surgery].

The authors investigated the intrahepatic lymphatic vessels of the human liver under a light and electron microscope. The histological material was obtained from 10 patients operated on account of simple cholecystolithiasis. The beginnings of the lymphatic capillaries are in the periphery of the perilobular connective tissue of the portobiliary space in the vicinity of openings of Mall's space.

Relationship between the saccus endolymphaticus and the fourth ventricle of the brain of the domestic fowl (Gallus gallus f. domestica).

The fine structure of the wall of the SE was determined exactly and its relationship to the cisternae (the evaginations of the roof of the fourth ventricle extending to the SE) was defined. The way in which the cisterna is formed was defined and the development of its fine structure was described by comparing serial sections from 19-day embryos and adult fowls. Like the SE, the cisternae are lodged in the angle between the cerebellum and the medulla oblongata, in the subarachnoid space.

[Ultrastructure of the air-blood-intestinal respiration barrier of the American sheatfish Hoplosternum thoracatum].

The fish, Hoplosternum thoracatum, lives in water with a permanently reduced content of oxygen. The respiratory gut as an accessory respiratory organ makes it possible to breath atmospheric oxygen and facilitates gaseous interchange. It forms a large, dilated tube containing a voluminous bubble of air.

[Changes the structural elements of the organs of bats during periods of activity and hibernation].

In hibernated animals (Myotis myotis) morphological changes are characterized by certain peculiarities in structure of the mitochondrial apparatus and some other cellular organells. In the animals, which are in the state of hibernation, the main plan of cardiomyocytes structure in the pulmonary vein wall, as well as in the myocardium itself does not change, as compared to those in the animals which are in the active state. The ultrastructure of the skeletal muscle fibers also does not undergo any essential alterations.

[Participation of the myocardium in the formation of the pulmonary vein wall of small mammals (a quantitative study)].

The thickness of the layer of cardiac muscle cells in the wall of the pulmonary veins was studied and quantitatively evaluated. The thickness of the intrapulmonary myocardial layer in the tunica adventitia of the venous wall depends on the body mass of the animal. This relation can be expressed by a hyperbola.