bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histomorphic changes following chronic adrenocortical activation and inhibition in the pigeon
Authors: Bhattacharyya Tapan K. , Ghosh Asok 
Published: February 2005

AbstractGravimetric and histologic modifications in the pigeon were studied following chronic therapy with ACTH and metopirone (SU 4885) for a period of 15 days. The organs studied were proventriculus, duodenum, heart, kidney, salivary gland, pancreas, liver, uropygial gland, thymus, spleen, bursa fabricii, testis, ovary, islets of Langerhans, adenohypophysis, thyroid and interrenal and chromaffin tissue of the adrenal gland. Induced states of hyper‐ and hypoadrenocorticalism elicited pathomorphic changes in endocrine and reproductive systems and some other organs of the pigeon. There were many differences and similarities in the nature of response of some organs following the two experimental conditions. Many of these cellular interactions might have resulted from alteration of interrenal function in the pigeon.
Haemocytes in the repair of wounds in an insect (Rhodnius prolixus)
Authors: Lai‐Fook Joan 
Published: February 2005

AbstractFour types of haemocytes may be distinguished in Rhodnius adults, based on their fine structure. The plasmatocytes are most active in the repair of an integumental wound. They contain dens homogeneous granules whose contents become less dense in response to wounding until microtubules about 150å in diameter are distinguishable. The significance of these changes is not yet known. Tight and intermediate junctions, and septate desmosomes appear between haemocytes which have accumulated in an excision.
The fine structure of the trout blastoderm,Salvelinus fontinalis(Mitchill)
Authors: Dickson D. H. , Battle Helen I. 
Published: February 2005

AbstractThe Speckled Trout blastoderm at the late high blastula stage is characterized by two different cell populations. The “light” blastomeres comprise one cell type while the “dark” and “medium” blastomeres appear to differ from one another only in degree and thus may be considered as the second type.“Dark” and “medium” blastomeres are irregular in shape, are located centrally and deep in the blastoderm, have an abundance of smooth endoplasmic reticulum with associated 520 Å glycogen particles and a single mitochondrial profile. The “light” blastomeres have randomly arranged glycogen particles in minimal quantities in contrast to the “medium” and “dark” blastomeres and in addition exhibit three mitochondrial profiles, which could however represent artifacts.It is postulated that in the Speckled Trout cellular differentiation has commenced by the third day of incubation at 10°C and that this is manifested visually by the appearance of two different cell populations; the more differentiated “dark” and “medium” blastomeres possibly destined to give rise to the hypoblast and the less differentiated “light” blastomeres.
Histology of the alimentary canal during the metamorphosis of Hyalophora cecropia (L.)
Authors: Judy Kenneth J. , Gilbert Lawrence I. 
Published: February 2005

AbstractThe histology of the alimentary canal is described for the last instar larva, pupa, and adult Hyalophora cecropia (L.). Particular attention is given to the changes occurring in the midgut during the larval‐pupal transformation and in the hindgut during the pupal‐adult transformation. Descriptions are made as to the nature of the imaginal rings at each end of the midgut and a new structure is described in the larval ileum. The formation of adult rectal pads is followed in detail.
Cyclic changes in the testis of the brook stickleback Eucalia inconstans (Kirtland)
Authors: Ruby Sylvia M. , McMillan Donald B. 
Published: February 2005

AbstractThe cyclic changes in the testis of the five‐spined stickleback Eucalia inconstans (Kirtland) were studied histologically. Specimens were trapped between July 1965 and July 1967 in a shallow pond near London, Ontario.A three‐dimensional microscopic study showed a main vas deferens and a system of primary, secondary and tertiary tubules.The testis cycle was divided into seven arbitrary stages. Spawning takes place from mid‐April to mid‐July. This is followed by the division of primary spermatogonia which are located along the walls of the tubules, producing cysts of spermatogonia enclosed in connective tissue which is surrounded by a thin epithelium. Both primary and secondary spermatocytes develop within these cysts. Breakdown of the cysts occurs with the development of spermatids and spermiogenesis occurs while spermatids are free in the tubules. Over‐wintering of mature sperm takes place. Development of mature sperm from primary spermatogonia takes about 156 days.Germinal epithelium is absent but primary germ cells are believed to be those cells occupying the spaces between the tubules of the testis. No tissue which might be implicated in hormone production was observed.Phagocytic invasion of the testis has been studied. Massive infiltration by phagocytes is believed to be responsible for the sudden increase in testis weight observed during spawning. These cells ingest sperm nuclei and groups of them have been observed in the lumen of the tubules and the vas deferens, probably on their way out of the body.
An ultrastructural study of the submandibular glands of the squirrel monkey, Saimiri sciureus
Authors: Cowley Linda H. , Shackleford John M. 
Published: February 2005

AbstractIn squirrel monkey (Saimiri sciureus) the position of submandibular glands in the neck, on either side of the trachea, more closely resembles that of rodents than that of other primates. The glands exhibit seromucous acini and mucous tubules with seromucous demilunes. Electron microscopy shows basal cytoplasmic folds and well‐developed intercellular tissue spaces and canaliculi only in relation to seromucous cells. Greatly dilated cisternae of the granular endoplasmic reticulum and prominent Golgi membranes are characteristic of the mucous cells. The secretory granules of seromucous and mucous cells are morphologically distinct and indicate chemically different products for the two cell types. Histochemically, the seromucous cell shows the presence of acid mucosubstance as indicated by the PAS and Alcian blue techniques. Preliminary studies showed no appreciable quantity of amylase in submandibular glands. The intercalated duct cell is juxtaposed with the acinar cell or mucous tubule cell. Short luminal microvilli, prominent Golgi complexes and scant apical granules are notable features of intercalated duct cells. Four cell types compose the striated ducts, viz., granular light cells, agranular dark cells, vesiculated dark cells, and basal cells. Peripheral nerves are found in five different locations: in the connective tissue (interstitial), between adjacent myoepithelial and mucous‐secreting cells, in the intercellular space between adjacent secretory cells, and between basal plications of striated ducts and between adjacent myoepithelial and intercalated duct cells.
The effects of essential fatty acid deficiency on the fine structure of mouse skin
Authors: Menton David N. 
Published: February 2005

AbstractMice raised from weaning on a diet free of essential fatty acids (EFA) develop a greatly thickened epidermis and stratum corneum with a concomitant increase in transepidermal water loss. The hyperplastic epidermis of EFA deficient mice is characterized by widely separated columnar cells in the stratum basale, an abundance of keratinosomes at the periphery of the cells in the stratum spinosum, and an unusually well‐developed stratum granulosum in which many keratinosomes are fused with the plasma membranes. Many vacuoles, lacking a membrane, are observed in the stratum granulosum and stratum corneum; these presumably correspond to histochemically demonstrable droplets of phospholipid. The horny cells in the stratum corneum of deficient mice also contain many membrane bound vesicles many of which can be identified as mitochondria. The most striking change in the horny cells, however, is the wide separation of epidermal filaments which may allow free diffusion of bulk water through the stratum corneum. The low rate of transepidermal water loss in normal skin may result in part from the ability of the stratum corneum to bind water in the small intersticies between the keratin filaments. The EFA, i.e., arachidonic acid, may serve to bind phospholipids to the structural protein of filaments and membranes thus binding water at these protein‐lipid interfaces.
An electron microscopic study of the spermathecal complex of virgin aedes Aegypti mosquitoes
Authors: Jones Jack Colvard , Fischman D. A. 
Published: February 2005

AbstractVirgin mosquitoes were studied with the electron microscope. Spermathecal duct walls contain cuticle, epithelium, and a richly innervated spiral muscle; myocytes are linked by desmosome‐like attachment plaques to the underlying epithelium. Periductal cells along upper portions of the ducts have a large secretory droplet within a highly irregular extracellular lacuna and are attached to a long secretory ductule through which finely granular material is delivered to the duct lumen and this enters the spermathecae. Basal gland cells of spermathecae have short ductules containing secretion in virgins. Secretory material in spermathecae of virgins does not form a complete internal membrane.
Comparative morphology, homologies, and functions of the male system in oribatid mites (Arachnida: Acari)
Authors: Woodring J. P. 
Published: February 2005

AbstractThe penis is basically a double‐walled oval cone. The weak type penis (only 2 species) has a weak tongue, lacks a bridge, and is elongate. The strong type (all others) has a bridge, a strong tongue, thicker walls, and is short. An accessory gland and a common vas deferens always open into the inner cup lumen (= ejaculatory duct). The massive tongue muscles may open the penal orifice. A pair of penal retractor muscles originate on the body wall. Penal protrusion and perhaps partial extrusion of stalk substance is by hemolymph pressure. The penis is completely homologous to the ovipositor. The genital discs are cuticular cups containing glandular tissue and are retractible by muscles originating on the body wall. The minute, rod‐like, immobile sperm are mixed with seminal fluid and stalk material secreted by seminal vesicle cells. This mixture is carried via the vase deferentia by peristalsis to the penis. Semen and stalk substance (protein) are somehow separated in the ejaculatory duct into separate pools, with stalk substance nearest the penal orifice. Upon penal protrusion, a bit of stalk material is extruded and fastened to the ground, and upon raising of the mite's body the stalk is “drawn out.” Finally, the ball of semen, adhering to the stalk tip, is pulled through the penal orifice.
Cell proliferation in vivo and in vitro in visceral organs of the adult newt, Triturus cristatus carnifex
Authors: Monnickendam Marjorie A. , Millar John L. , Balls Michael 
Published: February 2005

AbstractThe mitotic and labelling incidence of intestine, liver, spleen and pancreas cells of Triturus cristatus carnifex adults kept at 15°C, 20°C, 25°C and 30°C were examined. Intestine mitotic and labelling incidences were highest at 25°C and lowest at 30°C. There was no significant difference between 15°C and 20°C. No such relationship could be shown for liver, spleen or pancreas, which had very much lower mitotic and labelling incidences. In culture, intestine mitotic and labelling incidences fell significantly within the first four hours, and maintained these low levels for the next five days. In contrast, liver mitotic and labelling incidences rose for 9–11 days, and then began to fall, while pancreas mitotic and labelling incidences reached peak values at day 5, and were kept in good condition for up to 14 days.
A possible neuroendocrine system in polynoid polychaetes
Authors: Baskin Denis G. 
Published: February 2005

AbstractWithin the supraesophageal ganglion of polynoids is a vertical fiber tract which has the appearance of a “Y” in transverse sections of the brain, and contains the axons of many neurosecretory cells. The granule‐filled terminals of these neurosecretory fibers are found at the base of the tract where they are in contact with the inner surface of the sheath covering the ventral surface of the brain. This sheath separates these neurosecretory endings from an underlying pericapsular epithelium which is thicker in this region. Beneath this pericapsular epithelium is a coelomic sinus. The dorsal blood vessel is located within this sinus and is “innervated” by a pair of fiber bundles that pass out of the brain at the base of the vertical fiber tract. The outer surface of the vessel is covered by epithelioid cells which contact these fiber bundles and the thickened pericapsular epithelium, and sometimes contain granular cytoplasmic inclusions. The lumen of the vessel is continuous with the lumina of a pair of cellular, thickwalled structures of unknown function which are attached to the ventro‐lateral margins of the brain. The relationship between neurosecretory endings, enlarged pericapsular cells, coelomic sinus and blood vessel provides morphological evidence for the hypothesis that these structures are elements of a neuroendocrine system, similar in some respects to the brain‐infracerebral gland complex of nereid and nephtyid polychaetes.
The prenatal morphogenesis of the lateral nasal wall in the rat (Mus rattus)
Authors: Vidić Branislav 
Published: February 2005

AbstractIn the course of this investigation 24 fetuses of the Sprague‐Dawley rats were used. Pregnant animals were sacrificed at 12, 14, 16, 18, and 20 days of gestation. The fetuses were removed and fixed in buffered formalin solution. The heads were dehydrated, embedded in paraffin, and the nasal cavities were sectioned serially. Light microscope observations were made on 10 to 15 μ thick sections stained with H and E, Mallory's trichrome stain, and Gomori's alkaline phosphatase stain. The 12 day old fetus possessed well developed olfactory depression with a thick epithelial covering. The olfactory fossa was still separated from the buccal cavity by a solid layer of young mesenchyme. In the 14 day old fetus the communication between the nasal and buccal cavities was established. The palatal shelves developed still vertically. All the turbinates and the nasal capsule were already differentiated. The glandular system was represented with the main and two to three accessory excretory ducts. During the sixteenth day of prenatal development, the sinus and the sinus related glands became for the first time evident. The ossification of the membranous parts of the lateral nasal wall was initiated. In the next two developing stages the maturation of the cartilage, the increasing ossification in the membrane, and the further differentiation of the glands were the major morphological changes in the formation of the lateral nasal wall.
Ultrastructure of the excretory tubes of the mite Macrocheles muscaedomesticae (Mesostigmata, Macrochelidae) with notes on altered mitochondria
Authors: Coons Lewis B. , Axtell Richard C. 
Published: February 2005

AbstractThe fine structure of the excretory tubes of the mesostigmatid mite Macrocheles muscaedomesticae were investigated. These paired tubes are partially ensheathed by fat body and invested throughout by a branching system of visceral muscles. The fine structure of the cells of the excretory tube is in general similar with only minor differences found throughout its length. The basal region of each epithelial cell of the excretory tube borders the hemocoel and is divided into many compartments by the extensive infolding of the plasma membrane. Mitochondria and vacuolar inclusions are often closely associated with these compartments. More than one morphological type of mitochondria was found distributed throughout the cells of the excretory tubes. The most commonly encountered type had well developed cristae and an electron dense matrix. Less commonly, mitochondria with somewhat poorly developed cristae and a translucent matrix often containing myelin‐like figures of varying complexity were observed. It is suggested that they represent part of a normal process of mitochondrial degeneration. The apical region of the cell has a border composed of plate‐like folds of the plasma membrane termed microlamellae. The lumen contains abundant granules of the excretory product.
Genesis of the reproductive system of mosquitoes. III. Supernumerary male genitalia
Authors: Voorhees Frank Ray , Horsfall William R. 
Published: February 2005

AbstractThe origin of supernumerary gonapophyses in a polymorphic variant of Aedes stimulans has been determined histologically. Genotypic males (Mm) will develop gonapophyses on abdominal segment 8 when primordia on the larvae are subjected to a high‐to‐low thermal regimen. The gonapophyses develop from the normally evanescent podal buds of the eighth imaginal disc. Their course of development is similar to that of the normal gonapophyses that arise from the podal buds of the ninth imaginal disc.
Morphology of neuroglia in the hypothalamus of the opossum (Didelphis virginiana), armadillo (Dasypus novemcinctus mexicanus) and cat (Felis domestica)
Authors: Royce G. James 
Published: February 2005

AbstractThe hypothalamus of the opossum (Didelphis virginiana), the armadillo (Dasypus novemcinctus mexicanus), and the cat (Felis domestica) was studied using Del Rio Hortega's silver carbonate technique, as modified by Scharenberg ('60). This technique demonstrates astrocytes, oligodendroglia, and neuronal perikarya, but does not impregnate microglia. The morphology of macroglia was observed in ten comparable nuclei in each of the three species. The subpial and subependymal areas were also examined.Astrocytes display more cell body angularity and have more processes in most hypothalamic regions of the cat when compared to similar regions of the opossum and armadillo.In the anterior hypothalamic nucleus, the ventromedial and the dorsomedial hypothalamic nuclei, and the medial mammillary nucleus of all three species, astrocytes send processes to neurons, but neuronal and astrocytic perikarya are usually not directly contiguous. However, oligodendrocytes in a perisomatic position on neurons are a consistent feature in these nuclei.A closer relationship appears to exist between astrocytes and neurons in the neurosecretory nuclei. In the supraoptic nucleus and paraventricular nucleus of all three species a basket‐like structure, designated a „pericellular envelope”︁ was observed surrounding neuronal perikarya. This structure is composed of astrocytic and oligodendroglial cell bodies and processes, and is most highly developed in the cat.A dense astrocytic plexus was observed in the suprachiasmatic nucleus of the cat, and in the comparable nuclei of the armadillo and opossum. The most prominent macroglial cell type of the lateral hypothalamic and lateral mammillary nuclei of all three species is the interfascicular oligodendrocyte. The posterior hypothalamic nucleus of each species has many perisomatic oligodendrocytes, and in the armadillo and cat astrocytes are closely related to the larger neurons.A subpial plexus, consisting of a palisade of small glial cells with many processes, is present in the hypothalamus of the three species. Ependymal cells have long projecting processes throughout the length of the third ventricle in the armadillo hypothalamus, but such processes are only apparent in the region of the infundibular nucleus and median eminence in the opossum and cat.
A structural and functional analysis of walking in the turtle, Chrysemys picta marginata
Authors: Walker Warren F. 
Published: February 2005

AbstractWalking of Chrysemys has been studied by cinephotography and x‐rays. The lateral sequence, diagonal couplet gait, limb support sequence, and wide track provide great stability, yet a slight pitch and roll cause some plastral drag. Velocity ranges from 28 mm to 51 mm/second, and fluctuates within a stride. Limb movements and structure resemble those of other ectotherms, but incorporate modifications reflecting the animal's short, broad trunk encased in a shell and carried close to the ground. The triradiate pectoral girdle so articulates with the shell as to act as a truss for weight transfer to the ground. Girdle rotation increases the efficiency of the girdle as a truss, and contributes to locomotor efficiency. The glenoid cavities are more than twice as far apart as the acetabula, so a thrust from the pectoral girdle has less propulsive efficiency on the center of gravity than one from the acetabulum. The humerus and femur are protracted to a greater extent than in other ectotherms and their horizontal arcs of retraction are less. Rotation of these elements about their longitudinal axes contributes to the length of a stride and to foot placement and withdrawal. Differences in the movements of comparable segments of front and hind limbs correlate with differences in the width of the girdles, a crus longer than the antebrachium, and different capacities for joint rotation.
Tooth replacement in the red‐backed salamander, plethodon cinereus
Authors: Lawson Ronald , Wake David B. , Beck Nancy T. 
Published: February 2005

AbstractThe developmental cycle of the teeth in Plethodon cinereus is analyzed on morphological grounds using alizarin preparations. All the stages in development do not occupy the same proportion of the life cycle time. Functional teeth and germs at an early stage in development occupy a large proportion of the life cycle time, whereas the processes of tooth shedding and ankylosis occur very quickly. The time during which any locus does not bear a functional tooth, and is therefore a non‐functional locus, is reduced to a minimum. P. cinereus has a basic pattern of tooth replacement which is consistent with Zahnreihen which are 2.0 tooth spaces apart. Variations in the replacement pattern are common and these are produced by relatively small fluctuations in the spacing of the Zahnreihen around the „mean„ of 2.0. Localized disturbances which produce breaks in the replacement pattern and cause waves to cross also occur. These may be due to the failure of tooth germs to develop, the fusion of tooth germs, or may be the result of the inherent variability in a complex biological system. This variability causes individual tooth germs to develop too slowly or too quickly and hence assume an „abnormal”︁ position thus causing breaks in the replacement pattern. Tooth replacement may be controlled by an intra‐local mechanism(s) rather than by stimuli which travel along the jaw.
Comparative cardiac anatomy of the reptilia. I. The chambers and septa of the varanid ventricle
Authors: Webb Grahame , Heatwole Harold , De Bavay John 
Published: February 2005

AbstractExamination of the cardiac anatomy of lizards of the family Varanidae revealed that much of the previous literature contained basic errors both in description and interpretation. These are corrected and terminology of various authors is standardized.The varanid ventricle is similar to that of most other lizards in not being elongated, in having the base at right angles to the longitudinal axis, and in having the vertical septum weakly developed. However, it is not a typical lacertilian heart in that it has a number of characteristic ophidian features such as a muscular cone surrounding the cavum latero‐dorsale and a prominent twisting of the cava. It lacks a gubernaculum cordis and a cartilaginous rod in the septum aortico‐pulmonale, both of which are present in many non‐varanid lizards, but seldom occur in snakes. The location of the heart is more posterior in the body than is true of other lizards.