bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Spermatozoa of the Thysanuran Insects Petrobius brevistylis Carp. and Lepisma saccharina L.
Authors: Wingstrand Karl Georg 
Published: April 2010

AbstractThe spermatozoa of Petrobius and Lepisma share a few general insect features (filamentous shape, two mitochondria, compact acrosome vesicle, bilateral symmetry) but differ fundamentally with regard to specializations. In Petrobius, a long coiled acrosome, a coiled nucleus, and a “body” with axonema, two mitochondria, and a pair of lateral bodies follow each other in normal sequence. In Lepisma the acrosome is a small vestige in the spoon‐shaped anterior end, the centriole is dislocated anteriorly, and nucleus, two mitochondria and axonema run like parallel filaments through most of the spermatozoon. The centriole adjunct develops into a postnuclear body in Lepisma but forms a pair of complicated “lateral bodies” in Petrobius. It is concluded that ancestral forms must have had fairly primitive spermatozoa and that specialization has proceeded independently within each evolutionary line.
On a Peculiar Mode of Germ‐Layer Formation
Authors: Nørrevang Arne 
Published: April 2010

AbstractIn some planulae of the alcyonarian Gersemia rubiformis an interior structure was found in the entodermal cavity. It consisted of two layers separated by a basement membrane, the inner layer facing a central cavity. The outer layer was structurally identical with the inner “entomesoderm” of the body wall, while the inner layer of the “ball” was provided with numerous cilia and a brushborder. The development of the interior structure is described as appearing from the structural findings in different planulae. This development is very different from any other developmental process described so far.
Morphogenetic Actions of 5‐hydroxytryptamine and Some Analogous Substances on the Regeneration of the Planarian Worm Dugesia tigrina
Authors: Lenicque Pierre M. 
Published: April 2010

AbstractThe effects on regeneration of serotonin and analagous substances such as tryptamine, DMT, bufotenine, melatonin, auxin and gramine were studied on small pieces of D. tigrina. By comparison with results obtained in previous works with DOPA, α methyl DOPA and noradrenaline, and also with substances of the series of tetrahydrocannabinol it is shown that the normal morphogenetic action of the neurohormone is dependant of the presence of a free hydroxyl on a flat ring (phenol or indole) and of a free amine on the lateral chain of the molecule. Essays to detect the mechanism of the morphogenetic action did not allow to give any clear conclusion.
Antennal Sensory Hairs in Talitrid Amphipods (Crustacea)
Authors: Dahl Erik 
Published: April 2010

AbstractSensory hairs from antennulae and antennae of the two species Orchestia platensis Krøyer and Talorchestia deshayesii Audouin were studied by means of light microscopy and scanning and transmission electron microscopy. The complicated cuticular structures of the hair wall are described and figured. The central hair cavity opens in a rather wide terminal pore. Dendritic cilia from sensory neurons with perikarya inside the antennae run the whole length of the hair and terminate in the pore opening. The distal parts of the cilia contain osmiophilic material. It is concluded on morphological grounds that the hairs are chemosensory organs.
Intestinal Enterochromaffin Cells in Branchiostoma lanceolatum, Studied by Fluorescence and Electron Microscopy
Authors: Hulting Gunnar 
Published: April 2010

AbstractUsing the Falck‐Hillarp method for demonstration of biogenic amines, the presence of indole alkylamine (possibly 5‐hydroxytryptamine) containing enterochromaffin cells in strongly ciliated areas of the lancelet intestine was confirmed. An electron microscopic investigation of these areas, i.e. the “lateral ciliated tract” and the “dorsal ciliated tract”, revealed two cell types. 1. Mucous cells, equipped with tall cilia and giant rootlets, constitute the dominating type. 2. Enterochromaffin cells, containing numerous electron dense granules, are sparsely scattered among the mucous cells. The intestinal indole alkylamine is believed to be involved in the regulation of ciliary activity.
A Second Granular Cell in the Endocrine Pancreas of the Hagfish Myxine glutinosa?
Authors: Thomas N.W. , Östberg Y. , Falkmer S. 
Published: April 2010

AbstractA light and electron microscopic re‐investigation of the pancreatic islet organ of the hagfish, Myxine glutinosa, has confirmed earlier observations that agranular and granular β‐cells are the predominant cell types. However, in addition a rare second granular parenchymal cell was observed in which the granules are spherical in shape with a mean diameter of 213 nm, contrasting with the predominantly ellipsoid granules which characterise the β‐cell. At present, this allegedly second granular parenchymal cell cannot be unequivocally equated with a named islet cell type and its nature remains somewhat problematic.
Effets de l'ablation de l'œil sur la morphogenèse du chondrocrâne et du crâne osseux de Salmo irideus Gib
Authors: Pinganaud‐Perrin G. 
Published: April 2010

AbstractThe effects of eye ablation in the morphogenesis of the trout skull (Salmo irideus Gib.)Removal of one or both eyes in rainbow trout (from 8 days before hatching to 6 days after) causes some malformations of development of chondrocranium and skull bones. The observations prove that they have a mechanical origin: they are due to a modification of the forces existing in the orbit region during the morphogenesis. Height of orbit is reduced by taenia marginalis sliding down, and length of orbit is reduced by lamina orbitonasalis moving backwards. The bone reproduces exactly cartilage deformations.RésuméDes ablations unilatérales et bilatérales du globe oculaire sont pratiquées sur des alevins de Truite à des stades variant de 8 jours avant à 6 jours après l'éclosion. A la suite de ces opérations, il apparaît que les malformations obtenues au niveau du chondrocrâne comme du crâne osseux sont d'origine mécanique et liées à des modifications des forces qui s'exercent au cours de la morphogenèse dans la région orbitaire. l'orbite est réduite dorsoventralement par l'abaissement de la taenia marginalis et dans son diamètre antéro‐postérieur par le recul de la lame orbitonasale. l'os suit fidèlement les déformations du cartilage.
Action de la prolactine chez l'Anguille intacte et hypophysectomisée
Authors: Lemoine Anne‐Marie , Olivereau Madeleine 
Published: April 2010

AbstractAction of prolactin in intact and hypophysectomized eels. IX Effect on N‐acetyl‐neuraminic acid (ANAN) content of the skin, in sea waterIntact male silver eels were gradually transferred from fresh water to sea water. The ANAN content of the skin is significantly reduced after 50 days in sea water. Ovine prolactin injected for 10 days is without effect on skin mucus.Eels were hypophysectomized the day before their transfer; after 20, 30 and 50 days in salt water, ANAN content is progressively reduced; prolactin injection starting just after hypophysectomy has no effect after 20 days, prevents the ANAN decrease after 30 days and significantly increases skin ANAN after 50 days. These effects are compared with those obtained after similar treatments in fresh water: in both media, mucus production is stimulated after prolactin treatment in hypophysectomized eels, but is not increased in intact animals. Simultaneous plasma sodium changes are discussed in the light of recent data on eel osmoregulation.RésuméChez l'Anguille intacte transférée graduellement en eau de mer, la teneur en ANAN de la peau subit une chute lente, significative au 50e jour. l'injection de prolactine pendant 10 jours n'a pas d'effet net.l'hypophysectomie pratiquée la veille du transfert en eau de mer provoque une diminution significative de la concentration en ANAN, 20, 30 et 50 j après l'opération. La prolactine ovine, injectée aussitôt après l'ablation, reste sans effet apparent après 20 j, puis normalise (30 j) et accroît nettement (50 j) le taux de l'ANAN cutané, reflet de la quantité de mucus. Ces réponses sont comparées à celles obtenues en eau douce, ainsi qu'aux variations de la natrémie dans ces deux milieux et discutées à la lumière de données récentes sur l'osmorégulation de l'Anguille.
Melanophore Responses and Intermediatelobe Activity in the Eel Anguilla anguilla after Injection of 6‐OH‐dopamine
Authors: Fremberg Monica , Olivereau Madeleine 
Published: April 2010

AbstractWhen 6‐OH dopamine (6‐OHDA) was injected into the body cavity of eels (Anguilla anguilla L.), which had been kept on a light background with continuous artificial illumination or a natural day‐night regime in May and June, evident but heterogeneous chromatic reactions were induced. After peripheral drug effects during the first 6 hours, the eels became darker for 2 or 3 days, whereupon the melanophore index (MI), in most cases, decreased. Darkening was accompanied by significant nuclear hypertrophy and moderate degranulation of the MSH (melanophore‐stimulating hormone) cells. Probably only some of the adrenergic nerves in the neural lobe were affected. The blood supply to the brain was decreased for several days after each injection. The results support the assumption that in the eel catecholamines released from nerve endings in the neural lobe inhibit the release of MSH from intermedia cells by their own action as an inhibiting factor, or by affecting an MIF (MSH‐release inhibiting factor) and/or an MRF (MSH‐releasing factor).
The Structure of the Hypothalamohypophysial Portal Vascular System in Acipenser ruthenus L. (Chondrostei)
Authors: Hansen Georg Nørgaard 
Published: April 2010

AbstractThe vascularization of the pituitary region in Acipenser ruthenus L. (Chondrostei) is described. The adenohypophysis has no direct arterial supply but is fed exclusively by a pituitary portal system supplied through a pair of infundibular arteries. Distinct portal vessels connect the lateral part of the primary plexus of the neurohaemal area (the median eminence) with the secondary plexus of the pituitary gland. The primary plexus enters the pars distalis paramedially, apparently without the formation of distinct portal vessels. The neuro‐intermediate lobe receives its blood supply exclusively from the primary plexus. The plexus intermedius gives off capillaries to the parenchyma of the intermediate lobe (an intermediate lobe sinus system). The saccus vasculosus receives (1) a “direct” supply, i.e. branches originating directly from the cerebral arteries and (2) an “indirect” supply, i.e. capillaries from the primary plexus. The pars distalis is drained into an unpaired ventral hypophysial vein, while a dorsal hypophysial vein, also unpaired, drains the plexus intermedius. These two veins join to form the unpaired hypophysial vein. The findings are discussed from comparative and functional viewpoints.
The Olfactory System in the Hagfish Myxine glutinosa
Authors: Holmberg Kaj , Lundin Vanja 
Published: April 2010

AbstractIn the hagfish Myxine glutinosa nerve fiber bundles in the lamina propria of the olfactory lamellae run dorsally and collect to form dorsal nerves which posteriorly enter the olfactory bulb. The nerve fibers in the lamina propria and in the transitional regions between the lamina propria of each lamella and the dorsal nerves display two different appearances: 1. Small fibers (olfactory axons) range approximately between 85 and 165 nm in diameter; the cytoplasm is more electron dense than that of large fibers; one or a few microtubuli are frequently seen in the cytoplasm, whereas mitochondria are seldom observed; 2. Large fibers range approximately between 500 and 1200 nm in diameter; the cytoplasm is electron translucent and mitochondria occur frequently. Nerve fibers in the dorsal nerves have a diameter of 100 to 500 nm and within a nerve bundle they are grouped in fasciculi with an estimated fiber density of 16/μm2. Figers with diameter exceeding 500 nm are very seldom seen in the dorsal nerves.The small fibers are with great certainty olfactory receptor cell axons, since their size, fine structure and organization in fasciculi is entirely similar to that described in other species. The structure and distribution of large nerve fibers are discussed with regard to the possibility that they either are efferent fibers which constitute an extrinsic innervation of the olfactory epithelium or are the axons of olfactory receptor cells.
Untersuchungen zum circadianen Sekretionszyklus der neurosekretorischen Kerngebiete der Maus*
Authors: Martin Dieter , Luppa Hans 
Published: April 2010

Abstract Investigations on the circadian cycle of secretion in the neurosecretory nuclei of mouse. The circadian cycle of secretion of both hypothalamic neurosecretory nuclei N. supraopticus and N. paraventricularis in mice was studied by histological, histochemical, biochemical and electron‐microscopical methods. Both areas undergo a circadian secretion cycle (24 h‐rhytm).The activity of metabolism increases at the beginning of night, whereas by day the cells are considered to be in a phase of restitution and transportation of the secretion. Especially increases the volume of the cell nuclei (synthesis of RNA and proteins) and the activity of the extralysosomal unspecific esterase rises to maximal values.From midnight till the beginning of the light‐phase the cells show a maximal volume of the nuclei and an increased secretion as well as higher activity of acid phosphatase and lactate dehydrogenase. Unspecific esterase activity, on the other hand, diminished. There was a noticable increase in the quantity of neurosecretion in both areas, it reached a maximum at the beginning of the light‐phase, whereas the volume of the nuclei and the activity of acid phosphatase and thiamine pyrophosphatase diminished. The neurosecretion is more and more transported to the hypophysis. The cells restitute during the light‐phase and reach their starting level.
Seasonal Changes in the Newt, Trituroides hongkongensis, Testis. II. An Ultrastructural Study on the Lobule Boundary Cell
Authors: Tso E. C.‐F. , Lofts B. 
Published: April 2010

AbstractAn electron microscopical study was made on the lobule boundary cells. They were found to show characteristic ultrastructures of a typical steroid‐producing cell. Changes in these cells were divided into five stages according to the development within the lobules. The possible significance of the changes and their correlation with the degree of steroid production at different stages are discussed.
Ultrastructure of the Testicular Interstitial Tissue of the Hagfish Eptatretus stouti
Authors: Tsuneki Kazuhiko , Gorbman Aubrey 
Published: April 2010

AbstractUltrastructure of the somatic components of the testis of the Pacific hagfish was studied. Interstitial cells, equivalent to Leydig cells of higher vertebrates, containing smooth‐surfaced endoplasmic reticulum and mitochondria with tubular cristae were found in the interstitial tissue, as well as leucocytes, fibroblasts and other cells of unknown role. Two kinds of somatic cells were observed in the testicular follicles: Sertoli cells and “stellate cells”. The significance of interstitial cells was discussed in relation to possible involvement in steroidogenesis.
Blood and Spleen Response to Isolation and Cold Stress in Little Brown Bats, Myotis lucifugus
Authors: Martin Kathryn H. , Stehn Robert A. 
Published: April 2010

AbstractFemale bats were housed singly or in groups and maintained at 5° or 23 °C. Red blood cell life spans were determined utilizing the disappearance of labeled sodium chromate (Cr51). Red cell counts, hematocrits, reticulocyte percentages and diameters, white cell differentials, and spleen histology were determined for bats subjected to three weeks of stress treatment. Isolated animals (warm and cold) had significantly lower hematocrits and red cell counts and significantly higher reticulocyte diameters and percentages than grouped bats. Random destruction of erythrocytes was initially higher in isolated bats. In cold and isolated animals the white pulp of the spleen was most reduced in quantity and in proliferative activity. Red pulp became highly engorged with erythrocytes and showed a hypertrophy of reticuloendothelial elements. Higher rates of random destruction are closely correlated with increased splenic erythrophagocytosis. Gold or isolation imposed separately are mild stress factors in little brown bats, while a severe stress response occurs when the two stressors are imposed simultaneously.
The Distribution of Sudoriferous Glands in the Hairy Skin of Reindeer (Rangifer tarandus L.)
Authors: Källquist Lollo , Mossing Torgny 
Published: April 2010

AbstractSkin samples were taken from forest reindeer (Rangifer tarandus L.) in order to study the distribution of apocrine tubular glands. Glands with well‐developed secretory epithelium were restricted to certain areas of the body, namely the foreleg pit, a narrow strip on the belly, the groin and on the legs. Well‐developed glands were also found in the oral angle and in the rump patch. The greatest amount was found in the ventral interdigital skin of both fore and hindfeet. In other parts of the body could only the excretory duct and a thin walled extension but no developed secretory epithelium be seen.
Functional Anatomy of the Alimentary Canal in the Fruit Bat, Eidolon helvum, and the Insect Bat, Tadarida nigeriae
Authors: Okon Eyo E. 
Published: April 2010

AbstractThe gastrointestinal anatomy of the frugivorous bat, Eidolon helvum was compared with that of the insectivorous bat, Tadarida nigeriae. Both show modifications related to differences in their food habits as well as other anatomical peculiarities. The gastroesophageal junction in Eidolon helvum possesses a sphincter‐like protrusion. The posterior 10 mm of the esophagus in the same bat has well developed gastric glands, while the stomach is unexpectedly very rich in zymogenic and parietal cells. The intestine in this species is about 170 cm long; the posterior 30 cm of this is of colonic histology, though showing no external morphological difference from the small intestine. The anterior duodenum of Tadarida nigeriae has an external protuberance consisting of mucus secreting glands. The intestine of this bat has no colon, but a very short rectum of goblet cells is present.
The Maturation of the Ovary in Wild Rabbits, Oryctolagus cuniculus, in South Sweden
Authors: Andersson Mats , Meurling Patrick 
Published: April 2010

AbstractIn the ovaries of wild yearling rabbits the histologic changes occurring between September and March were determined and related to age and season. It was found that a considerable part of the ovarian development is characterized by the growth of follicles which soon become atretic and form interstitial gland tissue. The ovarian development up to a “sub‐ovulatory” stage may be completed in the autumn in rabbits born early in the season, and later in those born late, so that by mid‐winter they are all in this stage. No ovulation was found in rabbits in the early stages of development, and it is suggested that the presence of interstitial tissue is essential for full reproductive capacity.
Effects of Hypophysectomy and Prolactin Replacement on Eel Kidney Structure During Adaptation to Sea Water
Authors: Olivereau Madeleine , Olivereau Jacqueline 
Published: April 2010

AbstractAfter 20 to 50 days in sea water (SW), regressive changes of the kidney occur at the same rate in intact and hypophysectomized eels (Anguilla anguilla). In SW, ovine prolactin (oPRL) increases plasma electrolytes and restores a fresh water (FW) kidney structure; cell height and nuclear area increase in main segments of the nephron: first (P1) and second proximal (P2), distal (D) and initial collecting (C) tubules. A differentiation of new tubules also occurs. This effect is less intense after hypophysectomy and greater in FW. A dose of 10 μg/g body weight/day for 10 days in SW produces some harmful renal effects, barely detected at 6 μg/g/day. The kidney plays a minor role in osmotic adjustment in SW when PRL secretion is reduced (intact eels) or suppressed (hypophysectomized); PRL treatment reverses effects of SW adaptation. An inhibition of gill sodium extrusion may explain the high blood sodium level; however, kidney histological changes suggest a renal participation, perhaps through reduced water permeability as in Platichthys.
Studies on the Fibrous Components of the Test of Ciona intestinalis Linnæus. I. Cellulose‐like Polysaccharide
Authors: De Leo Giacomo , Patricolo Eleonora , Lunetta Giuseppina D'Ancona 
Published: April 2010

AbstractChemical, histochemical and electron microscopic studies on the fibrous polysaccharide component of the test of Ciona intestinalis L. were made. The results showed cellulose‐like fibres to be present in the cuticle layer and in the ground substance. Bundles of fibres varying in diameter from 80 to 600 nm interweave to form a conspicuous network. The bundle appears to be formed of flat fibres, 10–13 nm in width, while the fibre is composed of fibrils 3.5–5 nm; the rectangular cross section of fibres can be supposed. The probable rôle of this polysaccharide is discussed.
The Ultrastructure of the Indirect Flight Muscles of the Monarch Butterfly, Danaus plexippus (L.) with Implications for Fuel Utilization
Authors: Wensler Rita J. 
Published: April 2010

AbstractThe fine structure of the dorsal longitudinal flight muscle of the monarch butterfly, Danaus plexippus (L.), is described. The high actin: myosin filament ratio in this fast muscle is likely related to extensive actin‐myosin filament interaction which must occur when tension is increased and maintained by repeated nervous stimulation as demonstrated by Kammer (1967) during the long downstroke of the wingbeat cycle.Glycogen particles are present in the granular fraction of the interfibrillar sacroplasm and among the myofilaments of the flight muscle of young butterflies. The distribution of the granules appears to be related to spatial forces within the muscle fibril for in resting butterflies the intermyofilament particles are generally located in rows parallel to the myofilaments, while they are in transverse bands in the H and I zones of animals fixed immediately after flight. Since the glycogen particles were not depleted during flight, this redistribution does not appear to be related to glycogen metabolism.Glycogen in the flight muscle was depleted during eight days of adulthood in butterflies fed on honey solutions, but lipid reserves increased in the same period.
Compound Eyes of Some Deep‐Sea and Fiord Mysid Crustaceans
Authors: Elofsson Rolf , Hallberg Eric 
Published: April 2010

AbstractThe compound eyes of the deep‐sea mysid Boreomysis scyphops and the two mysid species Amblyops abbreviata and Pseudomma affine, which are indigenous to deep fiords in Norway, have been investigated. The eye stalks are greatly transformed, but contain hypertrophied retinas. The ommatidia of all three species lack a dioptric apparatus, possessing only retinular cells, which are arranged in a cylinder‐like fashion. Folds from the retinular cells project into the “cylinder” and are covered with microvilli. The arrangement is explained functionally by an increase in the photopigment‐bearing surface as an adaptation to low‐light intensities. The orderly arrangement of microvilli in most arthropod compound eyes has been lost, and the arrangement is thus multidirectional in these mysids. With the photopigment dipoles arranged along the microvillar axis, the disorderly arrangement of microvilli signifies a more efficient capture of non‐polarized light. It is concluded that the mysid compound eyes show adaptations to low‐light intensities probably acquired during the species' evolutionary descent into deep‐sea habitats. Amblyops abbreviata and Pseudomma affine, belonging to genera with entirely transformed eyes and with an ultrastructure less “normal” than that of Boreomysis scyphops are believed to be earlier descendants into the deep‐sea habitats than the latter species, which belongs to a genus in which most of the species have well‐developed eyes.