bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative comparison of the amygdala in insectivores and primates
Authors: Stephan H. , Andy O.J.
Published: February 2009

Comparative architectonic studies have resulted in a classification of the amygdaloid complex which differs somewhat from the commonly used classification (first proposed by Humphrey, 1936) by separating the cortical amygdaloid nucleus from the centromedial group and assigning it to the basolateral group, which then forms a cortico-basolateral group. The size changes of these groups and of the nucleus of the lateral olfactory tract (belonging to the centromedial group) and the large-celled part of the basal nucleus (belonging to the cortico-basolateral group) have been investigated in representatives of an ascending primate scale. In all structural complexes investigated so far, the small-celled part of the cortico-basolateral group is the most progressive. In descending order of progression there follow: the cortico-basolateral group as a whole, the amygdala as a whole, and the large-celled basal nucleus. No clear changes were found in the centromedial group as a whole, whereas the size of the nucleus of the lateral olfactory tract, which represents a small component of this latter group, shows a strong reduction. These differences in the developmental trends point to increasing or decreasing capacities of the functional (limbic and olfactory) systems, to which these structures are related.
Appearance of free histones within nuclei of differentiating cells in the developing rat embryo
Authors: Csaba G. , Bukta Andrea , Kovács P.
Published: February 2009

Having applied the picric acid-bromphenol blue (BPB) and the phosphomolybdic acid-benzidine (PMA-B) methods – the first method detecting the total histone content, the second one only free histones – we have found that cell nuclei of the rat embryos permanently contain histones, nevertheless, in such a pattern that the free histone appears only at a well-defined stage of the embryogenesis. Strong PMA-B reaction is observable in the nuclei of some mesenchymal cells and in the reorganizing somites’ cell nuclei of the 13-day-old embryo as well as in the hemopoietic elements of the 15- and 17-day old embryos’ liver. Within nuclei of the red blood cells of the 13-day-old embryo an extremely intense reaction is seen which then disappears till the 15th day, while the BPB reaction shows a gradual intensification up to the neonatal age. The experiments support the former model of one of the authors for a histone-nonhistone control of ontogenesis.
Ultrastructure of the human aortic valve
Authors: Missirlis Yannis F. , Armeniades C.D.
Published: February 2009

The human aortic valve is examined histologically by light, transmission electron and scanning electron microscopy. The observations show that the valve leaflets are multi-laminated structures, whose laminae do not have very distinct boundaries. Through the whole thickness of the leaflets, the load-bearing collagenous fibers are preferentially oriented in the transverse direction. Elastin networks are found only in the ventricular area. The leaflets attach themselves to the ventricular musculature through very dense collagenous meshworks known as the aortic ring. The whole structure is very efficient for its function of sustaining large pressures when closed and opening under minimal pressure gradients in systole.
Sexual dimorphism of bone robusticity in different strains of rats
Authors: Riesenfeld Alphonse
Published: February 2009

A quantitative method was used to establish the sexual dimorphism of bone robusticity in 10 domesticated strains of rats and in wild rats. Sexual dimorphism had its highest frequency in the pelvis, followed by the ulna, the skull, and the femur and tibia. Humerus and tail showed the lowest frequency of such sexual dimorphism. This distribution in an unspecialized mammal such as the rat, in which selective pressures are at their minimum because of the factor of domestication, can serve as a baseline for comparison with taxa in which selective forces are more strongly active.
Ultrastructural characteristics of tuft cells in mouse gallbladder epithelium
Authors: Nevalainen Timo J.
Published: February 2009

Mouse gallbladder was fixed by perfusion or immersion in glutaraldehyde and/or osmium tetroxide for electron microscopy. Besides usual columnar epithelial cells there were infrequent tuft cells in the epithelium. The cells rested on the basal lamina and extended to the gallbladder lumen. The microvilli on the apical cell surface were tall and thick and there was a rich network of microfilaments radiating from the core of the microvilli to the apical and juxta-nuclear cytoplasm. Among the bundles of microfilaments there were vertically oriented microtubules in the apical cytoplasm. Although the function of the tuft cells in the gallbladder epithelium remains unknown, it is proposed that their unique morphology may reflect a specialized resorptive function involving motility of microvilli and other cell organelles.
Innervation of the carotid body, types of nerve endings and their possible significance
Authors: Vázquez-Nin Gerardo , Costero Isaac , Λguila Roberto , Echeverria Olga M.
Published: February 2009

The nerve endings in the carotid body of normal cats are investigated by means of serial sections. Two types of endings not described previously are especially studied: the non-synaptic bouton and the meniscus with prolongations. The first is a small nerve ending with abundant mitochondria and glycogen which is devoid of synaptic vesicles. The second is a normal meniscus which presents prolongations containing the same cytological elements of the nonsynaptic boutons. It is proposed that some menisci are lateral endings of an afferent fiber. Relating these results with well-known functional characteristics of the carotid body, the existence of axonal reflexes is suggested. These views can explain apparently contradictory facts.
Observations on the growth of the normal male mouse
Authors: Silbermann Michael , Kedar Tamar
Published: February 2009

The pattern of body weight gain, the longitudinal growth of the humerus and the changes in the width of its proximal growth plate were determined in normal ICR male mice. The respective growth rates were calculated and compared throughout the animals’ first year of life. It was found that the overall growth period can be divided into four phases which differ markedly in their growth rates. Whereas skeletal maturation is reached at the age of 20 weeks, the animals’ body weight continues to increase up to the end of the 52nd week. The humeral growth plate retains its existence and function until old age is reached, i.e. 15 months. During the period of highest growth activity extending between weanling and sexual maturation, the growth velocities of the various parameters do not coincide.
Molar odontogenesis in the hairless mouse
Authors: Payne Michael , Gartner Leslie P. , Hiatt James L. , Provenza Vincent
Published: February 2009

Molar odontogenesis was studied in the hairless mouse from the initiation of the dental lamina through apposition. The dental lamina stage of the first molar was recognized on the 13th day, the bud on day 14th, cap on the 16th, bell on the 18th and apposition on the 20th day after conception. The morphology of the various stages and their temporal sequence were compared with those of other rodents.
Culture in vitro de cellules de liquide peritoneal humain
Authors: Gotzos Vassilis
Published: February 2009

The author has studied the behaviour of cells from human ascitic fluid in long-term culture (5–6 months). Three cellular types are described with different morphological features, namely the cellular shape, the fashion in which the cell spreads on the glass, the nucleo-cytoplasmic ratio, the chromatin appearance and the abundance of mitochondria. The three cellular types can phagocytose, but each one in a different way. The first one phagocytoses exclusively erythrocytes ‘by contact’ without emission of pseudopods; the second one phagocytoses degenerating nucleated cells in the same way as the first; the third type phagocytoses degenerating nucleated cells by emission of long pseudopods. The origin of these three cellular types is discussed; it is felt that they are transformed mesothelial cells. According to this study, it cannot be excluded, especially for the second and the third type, that they are histiocytes coming from serous membranes. The life in vitro of the three cellular types is depending upon the composition of nourishing medium. Cells can divide by mitosis only during the first 10–15 days of culture (mitotic index 0.1–3.0‰). Nuclear amitosis, nucleolus expulsion into cytoplasm and cytoplasmatic DNA synthesis can be observed in healthy cells.
Regeneration of masseter muscle following lidocaine-induced degeneration
Authors: Dolwick M.F. , Bush F.M. , Seibel H.R.
Published: February 2009

The histoenzymatic characteristics of regenerating myofibers of rat masseter muscle following injection of 2% lidocaine, as well as morphometric and histochemical characteristics of the typical myofibers, were investigated. Myoblasts appeared initially by day 1 among numerous macrophages within the confines of degenerating myofibers. Myotubes predominated by the 3rd day. Complete regeneration of the muscle occurred by at least 45 days. Phosphorylase activity was absent at day 1 and reappeared by the 5th day when the regenerating myofibers showed slight activity. By the 15th day the myofiber types had partly differentiated; red myofibers were smaller and stained less intensely than the white myofibers. Myotubes stained uniformly for succinic dehydrogenase activity from 3 until 5 days. After 5 days this staining increased gradually. Myofiber types began differentiation by 15 days and were fully differentiated by 45 days. ATPase activity was barely evident by 1–3 days. This activity appeared uniformly low up to 5 days and increased to an intensity comparable with that of the typical myofiber by 15 days. Slight leucine aminopeptidase activity occurred in macrophages 1 day following injection. By 3 days this activity appeared in the remaining myoblasts and in the myotubes. Some activity was found in the fibroblasts. This staining intensity at 5 days .was equal to that of earlier lesions. A trace of this activity was found at 7 days, and none at 15 days. Glucose-6-phosphate dehydrogenase activity was present in the macrophages by day 1. It increased by 3 days and occurred mainly in myoblasts and myotubes. This activity decreased by 5 days, and none was found by 7 days.
Effects of ionizing radiation on incisor development of the prenatal mouse
Authors: Gartner Leslie P. , Hiatt James L. , Provenza Vincent
Published: February 2009

The effects of 400 rad of X-irradiation of incisor development in CD1 mice were studied. 24 pregnant mice were irradiated on the 12th day post coitum and sacrificed from the 14th through the 20th gestational days. The 191 irradiated fetuses were smaller than those not irradiated, their crania and necks were malformed and their lower extremities were poorly developed. The developing incisors of the irradiated animals were retarded, the pulpal vessels were enlarged and the vessel walls did not maintain their structural integrity. The cells of the future pulp were necrotic, and the basement membranes appeared hyalinized. Ameloblasts and odontoblasts were abnormal in morphology and the formation of dental hard tissue was inhibited in places. Complete absence of incisor tooth germ was noted in three of the fetuses.
An unusual flexor of the fifth finger
Authors: Carr N.D. , O’Callaghan J.D. , Vaughan R.
Published: February 2009

An unusual digastric flexor muscle of the 5th finger is described arising from the medial epicondyle of the right humerus and being inserted into the proximal phalanx of the 5th finger. Also observed was the absence of flexor digiti minimi and the unusual smallness of the tendon of flexor digitorum superficialis of this finger.
Enigmatic bodies in human corticotroph cells
Authors: Horvath E. , Ilse G. , Kovacs K.
Published: February 2009

Fine-structural study of large, vacuole-like structures of the human corticotroph cell (‘enigmatic body’; EB) revealed that these bodies have a preferential juxtanuclear position in the vicinity of the Golgi complex. EBs have rugged outlines, frequently a narrow electron-dense rim and numerous membrane-bound compartments in an almost homogeneous matrix of low electron density. Fusion between EBs and secretory granules and other cytoplasmic components was noted. The peripheral rim and the matrix exhibited moderate to strong acid phosphatase activity. The inner compartments were consistently negative. It is proposed that EBs represent special lysosomes and serve as centers for recycling secretory material, as well as for storage and release of degraded products.
Gross and microscopic anatomy of the major salivary glands of the ferret
Authors: Poddar S. , Jacob S.
Published: February 2009

The gross and microscopic anatomy of the major salivary glands of the ferretwas studied. There were 5 pairs of major salivary glands, parotid, submandibular, sublingual, molar and zygomatic. They were of compound tubuloacinar type and consisted of numerous lobes and lobules. The parotid gland was grossly similar to the parotids in other mammals but histologically it was seromucous as in the carnivores dog and cat. The parotid duct opened into the vestibule of the mouth opposite the upper third premolar tooth. The submandibular gland was single on each side, oval in shape and cervical in position. Histologically it was entirely mucous. The submandibular duct opened at a sublingual papilla in the oral cavity at the side of the frenulum of the tongue. The sublingual gland was the smallest of the major salivary glands. It was single on each side and lay deep to the digastric muscle. It opened by several small ductules into the submandibular duct. It was mainly mucous and did not contain intercalated and striated ducts. The molar gland was located superficially near the angle of the mouth. It was irregularly pyramidal and opened by several small ducts into the vesibule opposite the lower molar teeth. It was predominantly mucous. There were no intercalated or striated ducts. The zygomatic gland was present deep to the masseter and related to the orbit in the infra-temporal fossa. The gland opened by several small ducts into the vestibule opposite the upper molar teeth. It was also predominantly mucous and there were no intercalated or striated ducts.
Measurements on the kidneys and vasa recta of various mammals in relation to urine concentrating capacity
Authors: Munkácsi Istvan , Palkovits Miklós
Published: February 2009

Maximum urine-concentrating capacity (UCC) differs widely among mammals of different species, being very high in some desert species (e.g. kangaroo rats) and very low in freshwater aquatic species (e.g. beaver). In this study, kidneys of 21 species of mammals from widely different habitats were studied in histological sections to determine whether differences in UCC can be attributed to differences in kidney structure. Parameters studied included the ratio of medullary to cortical thickness, the proportional subdivision of the medulla into inner and outer zones, and the dimensions of the vasa recta expressed in terms of the total area and the number of lumens within the vascular bundles. Determinations were made at a level where the size of individual vasa recta bundles has reached a constant maximum size, i.e. in the distal half of the outer zone. A positive correlation was found between the UCC and the ratio of medullary length to cortical thickness. No clear correlation existed between the proportion of the medullary length comprised of outer or inner zones and the UCC, although a trend to higher UCC in animals with relatively longer inner zones was apparent. Thus, it appears that the relative length of the entire medullary region is a major factor determining UCC, but the length of individual medullary zones is of lesser importance. A correlation was also found between the density of vasa recta per cubic millimeter of medullary tissue (the number of lumens regardless of identity in bundles, based on the number counted at the level sampled) and the UCC of the species. Data reported here support the view that UCC can be correlated with two parameters of kidney structure – the length of medulla relative to that of cortex and the density of vasa recta within the outer zone. It is proposed that the anatomical characteristics of the vascular supply to the medulla – that is, the vasa recta – are equally as important for the concentration of urine as is the primary mechanism determined by the characteristics of the loop of Henle and collecting ducts.
Absence of mitral cells in monolayer in monotremes
Authors: Switzer, III Robert C. , Johnso John Irwin
Published: February 2009

An invariant feature of the olfactory bulb in placental and marsupial mammals is the arrangement of the perikarya of mitral cells in a monolayer. Contrasting with this is the arrangement found in the olfactory bulbs of the monotremes, platypus and echidna, where the large perikarya are not only absent from the position of a monolayer (usually forming the external boundary of the internal plexiform layer) but occupy a region which would characterize them as tufted cells. In other classes of amniote vertebrates, reptiles and birds, the placement of large perikarya in the olfactory bulb ranges from a compact layer to a broad band. Such an overview among several vertebrate classes suggests that a monolayer of mitral cells may be a specialized subset of the tufted-mitral cell population. The accessory olfactory formation among mammals also exhibits variation in the compactness of the large perikarya: a broadband in most but a compact layer in a few others such as the chinchilla and the capybara. Such specialized alignment of perikarya (and, consequently, of their dendritic and axonal elements) may enable more refined signal processing than does random alignment of these elements. Such speculations can be tested using appropriate phylogenetic sampling, and monotremes provide particularly advantageous test cases.
Somata of feline extra-ocular muscle proprioceptors
Authors: Sivanandasingham P.
Published: February 2009

The somata of proprioceptive fibres in extra-ocular muscles have been localised to the trigeminal meseneephalic nucleus in twelve cats. This has been achieved by the demonstration of unequivocal changes of chromatolysis in the neurons of this nucleus following selective orbital resection of extra-ocular muscles. The localization of the somata has been shown to be bilateral, and a topographical subdivision in the nucleus in which different muscle groups are represented in different areas of the nucleus has also been demonstrated.
The roll of the antagonistic muscles in the calculation of muscle moments during trochlearthrosis work
Authors: Santos Luis
Published: February 2009

From the biomechanic point of view, the osteo-myo-articular system works as a physical pulley instead of working as a simple closing and opening of the angle formed between two arms of lever turning around the same point of support. The vector which expresses the force of muscular flexion being always ‘sliding’; its moment is constant independently of the angular value between the bone segments which are in flexion.
Excision and localisation of the avian (Gallus domesticus) carotid body
Authors: Dreyer Maria V. , De Boom H.P.A. , De Wet P.D. , Le Roux J.M.W , Coetzer D.J. , Eloff F.
Published: February 2009

The ‘anatotopography of cranial thoracic inlets, the carotid body and associated structures in the caudal pole of the thyroid gland are described. The source from which the various groups of fowls (n = 65) were obtained as well as the varied localisation of the carotid body are indicated. In this investigation, the carotid body was found to be situated mostly (49 cases) either on or in the immediate vicinity of blood vessels (carotid and inferior thyroid artery) and only in 14 cases in close association with the parathyroids.
Blood supply to the testis of a Brazilian marsupial (Didelphis azarae) and its abdominotesticular temperature gradient
Authors: Godinho H.P. , Cardoso F.M. , Nogueira J.C.
Published: February 2009

The testicular arteries of Didelphis azarae originate from the abdominal aorta either independently from each other or by way of a common trunk. Accessory testicular arteries may be found. At the spermatic cord they form a rete mirabile having 26.8 ± 5.0 and 29.3 ± 4.9 slender branches on the right and left sides, respectively. The arterial branches are intermingled with veins of similar caliber and number. Near the testis the branches of the rete reunite in a single vessel which then penetrates the parenchyma of the testis. Inside the testis the artery divides usually into two main branches that course toward the caudal pole. The rectal, scrotal and testicular temperatures were 32, 28.5 and 30.4 °C, respectively, appearing that an abdominotesticular gradient temperature exists in this animal. Whether this mechanism is thermoregulatory for the normal spermatogenesis cannot be inferred from the present work.
Effects of corticosteroid hormone on the epiphyseal growth center of immature pregnant mice
Authors: Silbermann Michael , Levitan Shoshana
Published: February 2009

Immature pregnant mice treated with glucocorticoid hormone (triamcinolone hexacetonide) were killed 1 week following delivery. The epiphyseal growth plates of the humerus and their cellular constituents were analyzed quantitatively. It became evident that pregnancy per se evokes a marked suppressive effect upon young cartilage cells, thus interfering with the normal process of endochondral bone formation. Pregnant mice treated with glucocorticoid hormone experienced an even higher degree of chondrocytic derangement, however, to a lesser extent than chondrocytes of nonpregnant mice treated with the hormone. It therefore appears that pregnancy-induced elevation of systemic estrogens and progesterone provides some kind of a protection against the antianabolic activity of glucocorticoids upon chondrocytes.
Ultrastructure of the uterine epithelium of mice treated neonatally with estrogen
Authors: Mori T.
Published: February 2009

In neonatally estrogenized mice, uterine epithelial cells possessed a few microvilli on the fuzzy-appearing apical surface, regardless of the presence or the absence of estrogen. The cells showed well-developed rough endoplasmic reticulum and a large number of mitochondria, suggesting that the cells were actively functioning. At 13 months of age, the uterine epithelium of neonatally estrogenized mice was sometimes stratified and squamous. Spherical basal cells like those appearing in cancerous vagina in estrogen-treated mice made their appearance. These cells may have the capacity of autonomous proliferation.
Persistent hypoglossal artery in the fetus
Authors: Khodadad G.
Published: February 2009

The hypoglossal artery in a human fetus studied by post mortem angiography and microdissection is described. In contrast to the fetal form of the trigeminal artery which differs from the adult form by possessing branches supplying the pons and anastomotic branches to the cerebellar and internal auditory arteries, there were no major anatomical differences between the fetal and the adult form of the hypoglossal artery. The incompetence of the vertebral arteries in the presence of a hypoglossal artery is also emphasized.
Histogenesis of colon glands during postnatal growth
Authors: Maskens Alain P.
Published: February 2009

The development of colon mucosa during postnatal growth was analyzed in male BD IX rats using histological and radioautographic methods. Newborn animals already exhibited clearly recognizable crypts of Lieberkühn. DNA synthesis activity predominated in the lower two thirds of those crypts, as it constantly did during subsequent growth and in adult colons. The height of crypts at birth was already half the adult size. There was, in contrast, a dramatic increase in their number (more than 1,000% from birth to the 10th week, as observed on transverse sections). The mechanism by which new glands derive from the mucosal epithelium implies a longitudinal fission of preexisting glands.
Nucleolar activity in the primate dorsal root ganglion cells associated with dietary protein malnutrition
Authors: Manocha Sohan L. , Sharma S.P.
Published: February 2009

The nucleolar changes in the dorsal root ganglion cells of the squirrel monkey, Saimiri sciureus, have been investigated by the use of histological and histochemical methods in the healthy neonates (born to mothers maintained on 25% protein diet during gestation) and young adults, and compared with those observed in the protein-malnourished neonates (born to mothers maintained on a 8% protein diet during gestation). Also studied were young adults maintained on a high protein diet (25% protein) as well as on a low protein diet (2% protein content) for a period of 15 weeks. Whereas in the healthy animals (neonates and young adults) only a few cells show nucleolar budding and finally their extrusion into the cytoplasm, the protein-malnourished animals show a significantly enhanced nucleolar activity in the form of increased size (3–4 times the original) and active budding either from one focal point or at several places on the body of the nucleolus. In the neurons which show chromatolytic changes, these extrusions migrate to the nuclear membrane, wherefrom they pass on to the cytoplasm through an evagination of the nuclear envelope. Such a migration appears to occur by a focal dissolution of the nuclear membrane. It appears that, under conditions of severe malnutrition and advanced chromatolytic changes in the neuronal cytoplasm, the nucleolar material provides a compensatory mechanism for the increased cytoplasmic catabolism and loss of ribonucleoprotein material in order to facilitate additional protein synthesis for cell survival.
Effects of mitomycin C in postnatal tooth development in mice with special reference to neural crest cells
Authors: Nozue Tetuo , Kayano Teruo
Published: February 2009

Neural crest cells in the pre- and postnatal development of mice showed a specific sensitivity to mitomycin C. In mice injected with mitomycin C 24–48 h after birth and surviving up to the 9th day, a free or attached denticle in the pulp and a fibroma or excessive cell proliferation in the dental follicle or the periodontal ligament were seen; further, a dentinoma developed.
Electron-microscopic study of collagenous fibers of cultures of bone marrow from healthy children
Authors: Shvelidze T.I. , Tsagareli Z.G.
Published: February 2009

Bundles of collagenous fibers have been detected by means of the electron microscope in the intercellular space among hematogenic and stromal cells of 9- and 13-day cultures of bone marrow of two 6-year-old healthy children in course of formation of fibroblast-like cells. Detection of the latter in the cultures during growth gives rise to the suggestion that collagen-producing cells (true fibroblasts) may be formed in vitro. The data obtained are discussed in connection with the question of fibroblast-like cells transformed in vitro to true fibroblasts.
Muscle spindles in the inferior constrictor pharyngis muscle of the crab-eating monkey (Macaca irus)
Authors: Sengupta B.N. , Sengupta S.
Published: February 2009

Pharyngeal muscles were considered to be lacking in spindles. A search was made for the same in the inferior constrictor pharyngis muscle of the crab-eating monkey (Macaca irus). Muscle spindles were found for the first time in this muscle. Transverse serial sections and teased preparations were obtained from this muscle belonging to six such animals, and these tissues were stained by Masson’s trichrome and Ranvier’s gold method, respectively. Both the methods were successful in revealing these receptors. The potential significance of this finding was discussed in relation to the activities of the pharyngeal muscles and a suggestion for a thorough re-investigation of the so-called spindleless muscles was made.
Fine structure of canine thymus
Authors: Gorgollón Pedro , Ottone-Anaya Mirella
Published: February 2009

Normal thymuses of young-to-adult healthy dogs have been studied with light and electron microscopy. Two well-defined zones are observed both in the medulla and in the cortex. In the outer cortex including the subcapsular region, reticular cells and mitotic lymphoblasts are more numerous than in the inner cortex, whereas in the central portion of the medulla the small proportion of free lymphoid cells is more evident than in the outer medulla. Reticular cells can be classified into two main groups according to some morphologic features: epithelial and mesenchymal. Epithelial reticular cells seem to undergo a gradual transformation from the subcapsular region to the medulla, and finally they may become heterogeneous Hassall corpuscles. Mesenchymal reticular cells are represented by macrophages and dendritic-like cells. The latter cells are located in the inner medulla and fill the intercellular spaces with their long cytoplasmic processes. In some occasions these processes appear degenerated and plasma cells and eosinophilic leucocytes are found. This fact suggests different functional stages and a possible participation of the normal thymic medulla of the adult dog as a peripheral lymphoid organ.
Definition of the stages of the cycle of the seminiferous epithelium of the opossum (Didelphis azarae, Temminck, 1825)
Authors: Orsi Antonio Marcos , Ferreira Affonso Luiz
Published: February 2009

Spermatogenesis of the opossum (Didelphis azarae, Temminck, 1825) as revealed by the ferric hematoxylin technique is described. The spermiogenesis is subdivided in 15 steps characterized by changes observed in the nucleus and in the acrosomic structure of the spermatids. Using the morphological changes during the spermatids’ maturation, a classification into 10 stages is proposed for the various cellular associations during the cycle of the seminiferous epithelium of the opossum.
Electron-microscopic analysis of the mouse facial nerve near the geniculate ganglion
Authors: Shimozawa Atsumi
Published: February 2009

An electron-microscopic analysis of the mouse facial nerve near the geniculate ganglion shows that there are, on the average, 603 more nerve fibers in the portion of the nerve distal to the geniculate ganglion than there are in the part proximal to the ganglion. The average distal increase in the number of unmyelinated fibers is 444 and that in the myelinated fibers is 165. The somatic motor nerve fibers and the parasympathetic fibers in the mouse facial nerve may not contribute to the distal excess. It is possible that the increase in the number of unmyelinated fibers distal to the geniculate ganglion is mainly due to the presence of postganglionic sympathetic fibers in the facial trunk distal to the geniculate ganglion and the greater petrosal nerve. The distal increase in the number of myelinated fibers may be mainly contiibuted by the sensory fibers.
Surface coat in steroid-secreting cells of the mouse ovary
Authors: Familiari Giuseppe , Renda Tindaro , Motta Pietro
Published: February 2009

Steroid-secreting cells (luteal, thecal and interstitial cells) of the mouse ovary have been studied with the ruthenium red method to stain the ‘cell coat’. The results showed that a typical cell coat covers the entire surface of the plasma membrane except where the cells are connected by specific cell junctions. Further, particularly heavy concentration of ruthenium-red-reacting material was demonstrated in pericapillary and intercellular spaces. The differences in the thickness of the cell coat and its topographical modifications among different groups of steroidogenic cells may be related not only to intercellular adhesion and interactions but also concerned with a function of control in which the cell permeability is modified in relation with phenomena of cell recognition.
Ultrahistochemistry of matrix vesicles in elastic cartilage
Authors: Nielsen Ellen Holm
Published: February 2009

Matrix vesicles in the elastic cartilage of epiglottis were negative for acid phosphatase, alkaline phosphatase, and ATPase. This is in agreement with the very rare occurrence of mineralization of elastic cartilage. Only the lysosomes of the chondrocytes showed a positive reaction for acid phosphatase, and a positive reaction for alkaline phosphatase and ATPase was found in relation to the cells of the perichondrium.
KristaIlisation und Auflösung von Kollagenfibrillen während der Histogenese der Zwischenwirbelscheibe
Authors: Knese K.-H.
Published: February 2009

We studied the modifications of collagen fibrils during the histogenesis of the intervertebral disc of cats. In connexion with these studies it is necessary to distinguish between the fibrillar (functional) structure, the arrangement of fibrils, and the nature of fibrils, their diameter, period and other properties. Collagen fibrils (40–50 nm) of the anulus fibrosus enter in hyaline cartilage and split off in thin fibrils (8–10 nm). In this area the cartilage fibrils have a diameter of 20–22 m, in a greater distance the diameter is diminished to 7–8 nm. Analogous to the changing of the nature of fibrils, the number of the cells related to the sectional area is diminished. The cells of the anulus fibrosus resemble those of tendons. In the transition area their shape becomes roundish, the number of granular membranes is increased, a voluminous Golgi-Apparatus appears for a short time. Finally, the cells are once transformed in cartilage cells with a small reticulum or cells of fibrocartilage with a capsule and a decreased cytoplasm; some cells are disintegrated. In the capsule of the fibrocartilage cells, parallel orientated filaments exhibit a periodical arrangement. In the border of the capsule, filaments change into periodical fibrils. Therefore, we must regard cells and their surrounding intercellular substance as metabolic unity which in the cartilage may be characterized as the chondron.
Neural tube lesions in the offspring of hamsters given single oral doses of lathyrogens early in gestation
Authors: Wiley M.J. , Joneja M.G.
Published: February 2009

The lathyrogens aminoacetonitrile, D-penicillamine and semicarbazide were tested for their teratogenicity in hamster on day 7 of gestation at three different dose levels. The results showed that aminoacetonitrile and penicillamine were typical teratogens in hamsters, capable of causing significant embryotoxic effects consisting of increased fetal mortality, growth retardation and malformation. Semicarbazide at a dose of 100 mg/kg had only minor teratogenic effects, while slightly higher doses were lethal to the dams. The most severe fetal malformations following maternal exposure to aminoacetonitrile or penicillamine were exencephaly and encephalocele. Since lathyrogens inhibit the process of collagen cross-linking, the results of this study indicate that there may be an important relationship between collagen fiber formation in the embryo and neural tube closure.
Ausbildung und Topographie des Ganglion pelvinum beim Gerbil
Authors: Frewein J.
Published: February 2009

In the gerbil the nerve cells of the plexus pelvinus are concentrated on each side in a solid ganglion pelvinum. This deviates essentially from the pattern in man and the domestic animals where these cells are scattered all over the plexus pelvinus. The large ganglion pelvinum is connected craniodorsally with the nervus hypogastricus and dorsally with the nervi pelvini (from the first 2 or 3 sacral nerves and the last lumbar nerve). The apertura pelvis cranialis appears long and very oblique and, therefore, in the gerbil the ganglion pelvinum is located on each side cranially to the corpus ossis pubis and can be reached by a ventral laparotomy.
Additional effects of postpuberal estrogen injections on the vaginal epithelium in neonatally estrogenized mice
Authors: Mori T. , Nishizuka M.
Published: February 2009

In ovariectomized mice given 10 injections of 100 µg 17/3-estradiol at intervals of 2 weeks from 60 days of age, the vaginal epithelium was atrophic when killed more than 2 months after the last injection. If mice given 3 daily injections of 20 µg 17β-estradiol from the day of birth were similarly treated with estradiol after postpuberal ovariectomy, the vaginal epithelium was stratified and hyperplastic at autopsy performed more than 2 months later. These changes in the epithelium persisted for at least 30 days after transplantation of the vaginae to normal ovariectomized hosts. Neonatal treatments only did not produce such persistent vaginal changes. In view of these results, additional effects of neonatal and postpuberal injections of estrogen on the vaginal epithelium are evident. However, effects of such neonatal and postpuberal injections of estrogen might be transient on the uterine epithelium, since abnormal proliferation was not observed in it.
The ovarian and uterine ligaments: a light- and electron-microscopic study in the rat and guinea pig
Authors: Musgrove C. , Gosling J.A. , Dixon J.S.
Published: February 2009

Histological and histochemical light-microscopy techniques, supplemented by electron microscopy have been used to study the structure and autonomic innervation of the uterine and ovarian ligaments in the adult rat and guinea pig. In both species, the smooth muscle of the uterine ligament was continuous with that of the myometrium at the tubouterine junction and with the smooth muscle of the ovarian ligament. The musculature of the latter also extended into the mesosalpinx and the ovarian bursa, capsule and hilus. Using electron microscopy, smooth muscle cells of both ligaments were usually separated from their neighbours by small amounts of connective tissue, although regions of close approach between adjacent cells were frequently observed. In these areas, the plasma membranes of apposing smooth muscle cells were separated by 10–15 nm and were devoid of an intervening basal lamina. Concerning the arrangement of autonomic nerves, the smooth muscle of the uterine and ovarian ligaments in both species was not supplied by acetylcholinesterase-containing nerves. In the guinea pig, however, numerous noradrenergic nerves were observed amongst the smooth muscle cells of the uterine and ovarian ligaments, the mesosalpinx and the ovarian capsule and bursa. These findings were confirmed using the electron microscope, in which nerve terminal regions*containing characteristic small, dense-cord vesicles were encountered lying 50–100 nm from adjacent muscle cells. In contrast, the smooth muscle cells of the rat uterine and ovarian ligaments were devoid of a noradrenergic nerve supply. These results have been correlated with the observations of previous workers, and the significance of the present findings, particularly in relation to the functional activity of the adult uterine and ovarian ligaments, has been discussed.
Development of cartilage in transplanted future coronal sutures
Authors: Markens I.S. , Taverne A.A.R.
Published: February 2009

From fetal rat skulls, tissue containing the 19-day-old presumptive coronal suture was excised and transplanted onto the exposed dura mater of adult rats. Host animals were sacrificed after 1, 2, 3, 4, 5 and 6 days. From the results of these experiments, the following conclusions can be drawn: (1) in all transplants chondrogenic activity occurred, resulting in the production of ectopic cartilage, and (2) cartilage development only starts on the cerebral side of the transplanted embryonic dura mater just beneath the area of the presumptive suture. Transplanted presumptive sutures of 21-day-old rats do not produce cartilage. These findings suggest that the suture undergoes a process of maturation. The existence of an osteogenesis-inhibiting mechanism, located in embryonic sutural tissue and being transmitted to the developing dura, is discussed.
Transport of fat through jejunal absorptive epithelium in vitro
Authors: Mohiuddin A. , Ahmed M.M. , Chan H.L.
Published: February 2009

The mucosa of excised pieces of jejunum of fasting rats was exposed for 10 min to fresh chyme obtained from other rats which had been digesting either buttered bread or bread alone. The mucosa was then processed for electron microscopy of lipid material. After exposure to fatty chyme, fat globules were scattered throughout the cytoplasm of absorptive epithelial cells, and concentrated in both supranuclear and infranuclear components of the Golgi apparatus. They were also present within lymphatics of the villus. After exposure to both types of chyme, the basal parts of the cells were much elongated through collection of a finely granular deposit of non-lipid material. This collection was probably due to failure of clearance of absorbed material from the cells in the absence of blood flow through the villus.
Structure of the respiratory system of sheep as related to heat tolerance
Authors: Shafie M.M. , Abdelghany F.M.
Published: February 2009

This work was carried out in the Research Station for Animal Production (Faculty of Agriculture, Cairo University) to study the breed difference of native Rahmani and imported merino sheep in the structure of the respiratory system as related to heat tolerance. 12 animals from each breed were slaughtered to obtain the respiratory system for anatomical studies, 3 of each breed at 1, 4, 8 and 16 months of age. The main results were: The volume of the lung was larger in merino than in Rahmani (Egyptian native breed) sheep at all ages, nevertheless both breeds had an equal lung volume per 1 kg body weight at a given age. The native Rahmani breed has the privilege of larger dead space than the merino. The volume of the dead space was 125, 215, 291 and 386 cm3 in the Rahmani sheep and 76, 141, 195 and 251 cm3 in the merino at 1, 4, 8 and 16 months of age, respectively. The volume of respiratory space, on the other hand, was larger in the merino. It was 81, 182, 312 and 590 cm3 in the Rahmani and 90, 209 367 and 692 cm3 in the merino at the successive ages. The number of alveoli in the lung was greater in the merino than in the Rahmani. In both breeds, the number of alveoli in the lung increased with age up to 8 months. There was a high negative correlation between density and size of alveoli in both breeds. The merino had a vast surface of alveoli. The respiratory surface of the alveoli in the lung was around 11, 19, 30 and 43 m2 in the Rahmani, 13, 23, 37 and 55 m2 in the merino at 1, 4, 8 and 16 months of age. The native Egyptian sheep possessed a greater ratio deadspace/respiratory space than the merino. This is an anatomical adaptation of the Egyptian (subtropical) breed for efficient heat dissipation via the respiratory system without interference with the C02 and alkali reserve in the body.
Some observations on the morphological evidence for mechanism of the bile secretion
Authors: Shin Young Chul
Published: February 2009

The morphological evidence of the intracellular route of bile secretion was investigated in the liver of goldfish (Carassius auratus) as revealed by electron microscopy. Smooth surfaced tubules or cisterns within or adjacent to the Golgi apparatus showed linear saccular forms and contained sparse particulate or cloudy materials of low electron density. The isolated vacuoles were restrictedly found between the Golgi apparatus and the intracellular bile canaliculus or hepatocytic side at the zone of transition. These vacuoles showed no reaction for acid phosphatase activity, and contained only a few cloudy materials similar to those found in the saccular tubules and within the bile canaliculus. Some of these vacuoles fused with the luminal cytolemmas of the bile canaliculus. Based on these findings, it was assumed that these vacuoles are structures participating in transport and secretion of bile constituents and derive from the linearly sacculated tubules or cisterns in the Golgi zone. Duct cells showed no morphological evidence to suggest bile secretion.
Experimental protein malnutrition in squirrel monkeys: cytochemical interaction of nucleolus and cytoplasm in the anterior horn cells of the spinal cord of Saimiri sciureus
Authors: Sharma S.P. , Manocha Sohan L.
Published: February 2009

Nucleolo-cytoplasmic relationships have been studied using histochemical techniques in the spinal cord of healthy neonates compared with those born to mothers malnourished through most of the gestation period, and healthy and severely protein-malnourished young adult squirrel monkeys. Formaldehyde-fixed as well as fresh frozen tissues were used for histological study and for histochemical techniques to demonstrate lipids, carbohydrates, nucleic acids and enzymes of various metabolic cycles. Changes in the neuronal cytoplasm of the low protein animals appear to be related to impaired protein metabolism and energy transport. The nucleolus reacts to cytoplasmic changes by enlarging its size and by active synthesis of secretion of nucleolar material, which is then passed into the cytoplasm through an evagination of the nuclear envelope. The greater the degree of chromatolysis in the cytoplasm, the more active the nucleolus appears to be in terms of its enlarged size and transfer of secretion products into the cytoplasm. It is believed that the perinuclear accumulation of secretion products in the neuronal cytoplasm of the protein-deficient animals has its origin in the nucleolus. Such an accumulation in the severely malnourished animals appears to be a compensatory mechanism for the increased cytoplasmic 0 catabolism and loss of ribonucleoprotein material in order to facilitate additional protein synthesis for cell survival.
Comparative neurohistological observations on the pancreatic duct in certain birds and mammals as revealed by cholinesterase technique
Authors: Purwar R.S.
Published: February 2009

A comparative study of pancreatic duct innervation of Francolinus pondicerianus (grey partridge or safed teeter) and Suncus murinus (Indian musk shrew) as revealed by cholinesterase technique has been done for investigation. In Suncus pancreas, the AChE-positive ganglia, elongated and irregularly shaped, medium and large-sized, were recorded either on the periphery of the excretory duct or on the wall of the duct. No ganglia were recorded on the periphery, although the fibres of the ganglia were in close association with the periductular plexus and the fibres of the peri-insular plexus in Francolinus. In Suncus, multipolar and AChE-positive ganglia of various shapes, arranged in chain-like fashion on the duct, were recorded, whereas in Francolinus the multipolar ganglia of AChE-positive nature and of various shapes, arranged in chain-like fashion, were observed in the duct region.
The collagen of the gingiva and of its blood vessels
Authors: Alvarez-Morujo A.J. , Alvarez-Morujo S. , Alvarez-Morujo A.
Published: February 2009

The collagen of the gingiva and that of its blood vessels of several animal species and of man were studied with the scanning electron microscope following corrosion with pancreatin at 0.3%. The gingival collagen forms fundamental cells or fasciculi that are distributed throughout the entire territory. In the interior of the cells there are small balls either detached or in clusters. Because of the contact and the fusion of these balls with the collagenic fasciculi, and due to their resistance to the pancreatin corrosion procedure, we believe them to be condensations of collagen. The approximate size of these balls was 2 μm. The fasciculi that surround these cells have either the form of bundles or are united in bands. There is an abundance of blood vessels in the gingiva and they are surrounded by collagen. This collagen can assume any of varied positions. The relations that exist between the vascular collagen and that of the gingiva are different in every case.