Study on the morphology of the gall-bladder of the goat

200 gall-bladders of goat were studied for histology and histochemistry. The lining epithelium is tall columnar with striated border. The glands are mucous and serous, and the secretion of both surface and glands is a polyssaccharide-protein complex. The regional differences at neck, body and fundus of the gall-bladder are described. Few enterochromaffin cells with granules, which are PAS-positive and contain 5-hydroxytryptamine, are encountered at the wedge between the granular epithelial cells and the cells lining the crypts. The relationship between these cells and lymphocytic infiltration is discussed. The thick circular muscle layer at the neck region is considered a sphincter of the gall-bladder.     

Perspectives of the conservation of the marine and coastal ecosystems in the frame of the realization of the Convention on Biological Diversity

The specifics of the international and regional activity in the context of the realization of the Convention on Biological Diversity has been analyzed. The global aims, tasks, and criteria of the working program of the Convention on marine and coastal biodiversity are discussed. The actual direction of the investigations is analyzed; program actions are planned; arrangements essential for conservation of the biodiversity of marine and coastal ecosystems are proposed.     

The ultrastructure of the sinuatrial ring bundle and of the caudal extension of the sinus node in the right atrium of the rabbit heart

Summary The cells of the sinuatrial ring bundle are smaller than the ordinary myocardial cells; they have a regular outline and a large content of myofibrils exhibiting distinct H-bands and M-lines. Rudimentary T-tubules are found. The cells are connected by frequent nexus junctions, desmosomes and regions of interfibrillar contact, both on the well developed intercalated discs and at the periphery of the cells.The cells in the cauda of the sinus node, which extends alongside the crista terminalis together with the right branch of the sinuatrial ring bundle, are irregularly outlined and have a highly variable diameter (1–10 m). They occur in clusters of closely packed cells. The content of myofibrils is sparse and the fibrils exhibit no M-lines and only weak H-bands. No T-tubules are found. The cells are not connected by intercalated discs and no nexus junctions are found.Both tissues contain unmyelinated nerves and nerve fibres. Varicosities with mitochondria and vesicles are found in close apposition to the muscle cells.     

Ultrastructure of synapses in the nucleus of the trapezoid body of the bat]

The subsynaptic structure of the synapses in the medial nucleus of the trapezoid body was studied in the bat Myotis oxygnatus. The synaptic endings in the nucleus are represented by large-cup-shaped and small loop-shaped terminations. The cup-shaped terminations are formed of large branches originating from a thick myelinated fibre after loss of myelin from it. Each branch forms a series of contacts alternating with vast enlargements of extracellular space, on the body of the cell and its processes. Large branches are filled with synaptic vesicles, neurofilaments and neurotubules, mitochondria; all these components are distributed rather regularly along the branch diameter. In fine branches of the cup the synaptic vesicles are the main and often the only component. The pattern of the cup branch changes as the distance from the main fibre increases, namely the amount of neurofilaments and neurotubules diminishes up to their disappearance, while the amount and the density of synaptic vesicles increases. The small loop-shaped treminals are different from the cup-shaped ones by the composition of the synaptic vesicles and the structure of the contact zone. In addition to agranular vesicles there are also granular ones. Both types of terminations--cup-shaped and loop-shaped ones -- are found both on the bodies and dendrites. On distal portions of dendrites the terminations are disposed in nests.     

Ultrastructure of the stria vascularis of the auricular labyrinth of the rabbit]

In the composition of the stria vascularis of the rabbit cochlea there are three types of cells: edging, medial and basal cells. The structure of these cells, their disposition and interrelationships within the stria vascularis are described. The nodes of the basal membrane whose ramification covers long mitichondria concentrating at the basement of edging cells are found in the structure of capillaries of the cochlea stria vascularis. It may be supposed that this powerful mitochondrial apparatus refers to the capillary system of the stria vascularis and represents a hypertrophic mitochondrial apparatus of pericytes. The capillaries of the stria vascularis are distributed mainly in longitudinal direction while the capillaries disposed transversely which are likely to be anastomoses were also found.     

Demonstration of the heterogeneity of the mast cell population on the basis of the mucopolysaccharide content.

From the aspect of its mucopolysaccharide content the mast cell population is not homogeneous. The pulmonary and heart muscle mast cells of the rat are alcian blue positive, the mast cells of the thyroid gland, lymph nodes, subcutaneous connective tissue, mesentery and peripheral nerve are safranin positive, whereas among the mast cells of the peritoneal cavity and the thymus there are both alcian blue and saffranin positive forms. The least acid mucopolysaccharides are in the mast cells of the peritoneal fluid, the mesentery and the lungs, whereas the most acid ones are in the mast cells of the lymph nodes, the subcutaneous connective tissue and the thyroid gland. There is a considerable difference between the two last mentioned organs. The mast cells of the subcutaneous connective tissue are end-product cells without amine or precursor turnover, whereas the mast cells of the thyroid gland incorporate and deliver amines, which may participate in the regulation of the host gland.     

Growth of a graft from the septal region of the brain in the anterior chamber of the eye

The neural tissue (the hippocamp and septal cerebral area) obtained from rat embryos is transplanted into the anterior eye chamber of mature animals. The developing grafts are sized and measured and light optic microscopy is performed 3-4 months after transplantation. Essential differences in development and organization of the septal cerebral area (SCAG) and the hippocampal (HG) grafts are revealed. The SCAG have a spherical form, a limited contact with the host iris and are vascularized by one--two ingrowing and branching vessels. The HG are elongated in their form, have contacts with the host iris by the wide plane parallel to their long axis and a great number of blood vessels growing into them. The size of the HG is much larger than that of the SCAG. The latter contain diffusely scattered multipolar neurons, while the HG neurons are organized as a layer with their apical dendrites oriented towards the iris.     

Topography of the contours of the inner surface of the wall of the left ventricle of the heart in systole

Chosen at random 38 diastolic preparations of human hearts from persons having not any cardiac pathology, as demonstrate the postmortem examination, have been investigated. The left ventricle casts have been made during the first 24 hours after death according to a strictly fixed technique by means of filling the cardiac chambers with polymere mass--protacryl--under a physiological pressure of the diastolic filling. The trabecules are arranged as a spiral from the apex of the ventricle up to the atrioventricular fibrous ring, with approaching the apex the spiral step increases and the trabecules straighten. The left ventricle cast is devided into some planes, the envelopes and the trabecularity lines are measured. Average values of the shift in the trabecularity lines I, II, III and in the cross sections B, C, D, E are defined in relation to the plane A and in every case in relation to the previous plane Cn-1. The data obtained are presented in tables and diagrams. The greatest shift demonstrate the trabecularity lines I running predominantly along the posterior wall of the left ventricle in the planes B and which are situated nearer to the atrioventricular ring projection. Owing to the presence of the spiral-shaped course of the trabecules, it is possible to suppose that it influences the blood stream twisting clockwise in the left ventricle during the diastole phase. This indicates the necessity to work out some new constructions of artificial cardiac valves, securing the twisted blood stream. The condition mentioned should be taken into consideration while making prostheses of the cardiac valves.     

Histochemistry of the placenta of the pig

Summary The distribution of glycogen, RNA, lipid, acid mucopolysaccharides, diastase-resistant PAS-positive material, hydrolytic enzymes, specific and non-specific alkaline phosphatases, and carbohydrate dehydrogenases is described in the foetal and maternal placenta of the pig throughout gestation. The results are compared with the findings in similar and other placental types, and some deductions regarding the functional significance of the enzymes in the structures in which they are observed are made.     

Structure of the cross-striated adductor muscle of the scallop

The structure of the cross-striated adductor muscle of the scallop has been studied by electron microscopy and X-ray diffraction using living relaxed, glycerol-extracted (rigor), fixed and dried muscles. The thick filaments are arranged in a hexagonal lattice whose size varies with sarcomere length so as to maintain a constant lattice volume. In the overlap region there are approximately 12 thin filaments about each thick filament and these are arranged in a partially disordered lattice similar to that found in other invertebrate muscles, giving a thin-to-thick filament ratio in this region of 6:1.The thin filaments, which contain actin and tropomyosin, are about 1 μm long and the actin subunits are arranged on a helix of pitch 2 × 38.5 nm. The thick filaments, which contain myosin and paramyosin, are about 1.76 μm long and have a backbone diameter of about 21 nm. We propose that these filaments have a core of paramyosin about 6 nm in diameter, around which the myosin molecules pack. In living relaxed muscle, the projecting myosin heads are symmetrically arranged. The data are consistent with a six-stranded helix, each strand having a pitch of 290 nm. The projections along the strands each correspond to the heads of one or two myosin molecules and occur at alternating intervals of 13 and 16 nm. In rigor muscle these projections move away from the backbone and attach to the thin filaments.In both living and dried muscle, alternate planes of thick filaments are staggered longitudinally relative to each other by about 7.2 nm. This gives rise to a body-centred orthorhombic lattice with a unit cell twice the volume of the basic filament lattice.     

Ultrastructure of the respiratory epithelium in the lungs of the tortoise,Testudo graeca

The respiratory epithelium in the lungs of the tortoise (Testudo graeca) has been studied by electron microscopy. The epithelium consists of a mosaic of two different cell types (here called "pneumonocytes"). Type I pneumonocytes are roughly squamous and possess attenuated flanges of cytoplasm which extend over the septal capillaries. Localized cytoplasmic expansions are often present near the periphery of these flanges. Most of the organelles are concentrated in the perinuclear region; the most prominent of these are the mitochondria and osmiophilic inclusions. In contrast, type II pneumonocytes are cuboidal and are richly endowed with organelles including large Golgi complexes, extensive endoplasmic reticulum and numerous inclusion bodies. The morphological evidence suggests that type I pneumonocytes are involved in the secretion of osmiophilic material (presumed to be pulmonary surfactant) and in maintaining the integrity of the air-blood barrier. Type II pneumonocytes appear to be concerned solely with the production of surfactant.     

A review of the phylogeny and classification of the Asteraceae

The Asteraceae are commonly divided into two large subfamilies, the Cichorioideae (syn. Lactucoideae; Mutisieae, Cardueae, Lactuceae, Vernonieae, Liabeae, Arctoteae) and the Asteroideae (Inuleae, Astereae, Anthemideae, Senecioneae, Calenduleae, Heliantheae, Eupatorieae). Recent phylogenetic analyses based on morphological and chloroplast DNA data conclusively show that the Mutisieae-Barnadesiinae are the sister group to the rest of the family and that the Asteroideae tribes form a monophyletic group. The Vernonieae and Liabeae are sister tribes and the Eupatorieae are nested within a paraphyletic Heliantheae; otherwise tribal interrelationships are still largely uncertain. The Mutisieae-Barnadesiinae are excluded from the Mutisieae and elevated to the new subfamily Barnadesioideae. The two subfamilies Barnadesioideae and Asteroideae are monophyletic, whereas the status of the Cichorioideae remains uncertain. Analyses of chloroplast DNA data support the monophyly of the Cichorioideae; however, morphological data indicate that the subfamily is paraphyletic. Further studies are needed to test the monophyly of the Cichorioideae, as well as to further resolve tribal interrelationships in the two larger subfamilies.     

Ultrastructure of the ultimobranchial follicles of the laying chicken

Summary The ultimobranchial gland of the laying chicken consists of groups of C cells interspersed among a collection of intercommunicating follicles and ducts of variable size and shape. The epithelium lining this system ranges from squamous to columnar and includes stratified squamous and pseudostratified columnar elements. Four cell types are distinguished in this epithelium: F, mucous, C, and basal cells. F cells show microvilli and microfilaments. Pinocytotic activity and images of fusion of coated vesicles with the plasma membrane are evident. The rough-surfaced endoplasmic reticulum (RER) and the Golgi complex are moderately developed. Dense bodies are encountered apically in some cells. Mucous cells possess microvilli and secretory material in the typical form of partially fused droplets. C cells contain secretory granules and are invariably separated from the follicular lumen by other cell types. The smaller, pyramidal basal cells contain filaments, RER, small Golgi complexes, free ribosomes and hemidesmosomes. The lumina contain flocculent or granular material, cellular debris and desquamated cells. Morphological evidence demonstrates that features of the pharyngeal epithelium are retained and that the majority of the cell types, with the exception of C cells, are presumably nonendocrine.Supported by grant HES 75-09030 from the National Science FoundationThe technical assistance of Quan Nguyen is gratefully acknowledged     

Light microscopy of the medial wall of the cerebral cortex of the lizard Psammodromus algirus

The telencephalic medial wall of the lizard Psammodromus algirus was studied using Golgi and conventional light microscopic techniques. The area is formed by two different cytological fields—medial cortex and dorsomedial cortex. These two cortices possess three layers dorsoventrally: a superficial plexiform layer, a cellular layer, and a deep plexiform layer. The alveus, a deep fiber system, runs adjacent to the ependyma. Four classes of neurons are found in the cellular layer of the medial cortex on the basis of soma shape, dendritic pattern, and position in the layer: horizontal, double pyramidal, and candelabra cells. Solitary cells are present in the superficial and deep plexiform layers of the medial cortex. Those of the superficial plexiform layer are stellate cells. Horizontal and vertical cells are found in the deep plexiform layer. Double pyramidal cells are the most frequently impregnated in the cellular layer of the dorsomedial cortex. In addition, candelabra cells are present at the lateral end of the layer. Two cell types are found in the deep plexiform layer of the dorsomedial cortex: solitary pyramidal cells and, among the fibers of the alveus, horizontal cells. Ependymal tanycytes line the ventricular surface, and protoplasmic astrocytes are found in the plexiform layers of both medial and dorsomedial cortices.     

Some regularities of the regeneration of the musculature of internal organs]

The paper summarizes the data of the author and his co-workers on regulation of the musculature of vessels, digestive tract, uterus, ureters and urinary bladder. The smooth muscle cells have different degrees of differentiation. The muscular tissue of the vessels is most differentiated. The uterus musculature is very plastical. After injury mature myocytes are the first to undergo destruction. The intermedial substance is more stable. Myoblasts, young elements of the fibroblast row and the subendothelial layer cells are the origin of muscular regeneration. Figures of mitosis and amitosis are noted. Mature myocytes and intercellular substance are formed in the process of differentiation of the regeneration. The content of RNP in the regeneration cells is high, but in the process of differentiation of its elements it becomes lower. The DNP level has inconsiderable fluctuations. In early experiments PAS-positive substances are revealed in greater degree than in later ones. The content of acid mucopolysaccharides decreases in the process of fibrillogenesis. In all internal organs under study the muscular tissue regenerated. The degree of differentiation, severity of the lesion and functional peculiarities of the organ determine the completeness of the tissue reparation. The musculature of the intestinal tract and vessels regenerates more completely. Mighty layers of connective tissue with de novo formed blood vessels are disposed among the bundles of the repaired muscular tissue of the uterus and urine bladder wall. Simultaneously a part of regeneration cells are destroyed. These are two sides of a single process of development.     

Role of physiological factors in predicting the risk of oncological diseases on the basis of the polymorphism of the xenobiotic metabolism enzyme system

Summarized recent data on the polymorphism of the xenobiotic metabolism and detoxification enzyme (XMDE) system in humans are presented. The current notions on the molecular mechanisms of metabolic processes and the role of genetic polymorphism are reviewed. The roles of transport proteins and nuclear receptors in the regulation of the activity of the XMDE system are shown. The possibilities of using the polymorphism of the XMDE system as the basis for predicting the risk of oncological diseases are considered. Experimental modeling of different levels of the epoxide synthetase and epoxide hydratase activities revealed their close relationship with the toxic, mutagenic, and carcinogenic actions of polycyclic aromatic hydrocarbons. The data indicating the necessity of considering the physiological factors that could influence xenobiotic metabolism and the development of pathological changes are given.     

On the nature of the horny scales of the pangolin

The pangolin scale is a horny derivative of the epidermis. It is complex in structure and is divisible into three distinct regions. The dorsal plate forms approximately one-sixth of the scale thickness. It is composed of flattened solid keratinized cells without basophilic nuclear remnants. This region tends to fray easily. The dorsal plate contains bound phospholipids and sulphydryl groups but is weak in disulphide bonds.
The bulk of the scale is made up of the intermediate plate formed of less flattened cells without basophilic nuclei. This region is rich in disulphide bonds but contains no appreciable bound phospholipids or sulphydryl groups.
The ventral plate is only a few cells thick and is rich in bound phospholipids, which also occur in the underlying scale bed epidermis.
These three regions of the scale are formed from separate epidermal germinal areas which do not develop a granular layer. Keratohyalin granules are, however, formed in the epidermis between the scales.
It is suggested on the basis of histological structure and dishribution of chemical constituents that pangolin scales are probably homologous with primate nails.
Evidence against the views that they are homologous with reptilian scales or are derived from compressed hairs is presented.     

Ultrastructure of the endolymphatic sac in the larva of the Japanese red-bellied newt Cynops pyrrhogaster

The ultrastructure of the endolymphatic sac (ES) of the late stage larva of the Japanese red-bellied newt, Cynops pyrrhogaster (stage 57), was examined by light and transmission electron microscopy. The two endolymphatic sacs are located at the dorsal-medial side of the otic vesicle on the dorsal-lateral side of the midbrain in the cranial cavity. The wall of the sac is composed of a layer of cubical epithelial cells with loose, interposed intercellular spaces. The sac contains a large luminal cavity, in which endolymph and numerous otoconia are present. The epithelial cells of different portions of the sac have a similar structure. These cells contain an abundance of cytoplasmic organelles, including ribosomes, Golgi complexes, and numerous vesicles. Two types of vesicles are found in the epithelial cells: the “floccular” vesicle and the “granular” vesicle. The floccular vesicles are located in the supra- and lateral-nuclear cytoplasm and contain flocccular material. The granular vesicles have a fine granular substance and are usually situated apposed to the apical cell membrane. The granular vesicles are suggested to be secreted into the lumen, while the floccular vesicles are thought to be absorbed from the lumen and conveyed to the intercellular spaces by the epithelial cells. The apical surfaces of the epithelial cells bear numerous microvilli. Apparently floating cells, which bear long microvilli on the free surfaces, are observed in the lumen of the ES. Based on the fine structure, the function of the endolymphatic sac of the newt Cynops pyrrhogaster is discussed.     

Synaptic nature of the principal components of the evoked potential in the general cortex of the turtle forebrain

The nature of the principal components of the evoked potential of the general cortex of the turtle forebrain was studied in response to electrical stimulation of the contralateral optic nerve. Comparison of these components with postsynaptic potentials of the neurons of this structure showed that the four fast negative waves of the evoked potential correspond to fast EPSPs, which are independent of one another. The positive wave of the evoked potential is the sum of several IPSPs. The slow negative and, to some extent, the positive wave are a reflection of the slow EPSP. It is shown that early EPSPs are generated on portions of the apical dendrites which are further from the soma than those generating late fast EPSPs and also the IPSP and slow EPSP. Axo-somatic contacts are perhaps also concerned in the generation of the last-named potential.M. V. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 5, No.3, pp.261–271, May–June, 1973.