bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phagocytic Cells in the Peripheral Blood of the Dogfish Scyliorhinus canicula L. I. In Vitro Studies
Authors: Parish N. , Wrathmell A. , Hart S. , Harris J. E. 
Published: April 2010

AbstractIn vitro phagocytosis by peripheral blood leucocytes of the dogfish Scyliorhinus canicula L. was examined by exposing adherent cells to a variety of particulate and soluble antigens and inert material. Their subsequent uptake was monitored by light, scanning and transmission electron microscopy. The monocyte and the neutrophil‐like granulocyte were found to be the major phagocytic cells. Larger particles like yeasts and erythrocytes were the most avidly phagocytosed. From studies on the effects of pH, temperature and the presence of plasma, metabolic inhibitors and divalent ions, it appeared that optimum phagocytosis occurred at pH 7.0 and between 10 and 20°C. Serum factors did not enhance the process in this species. Finally, the in vitro clearance of 5 bacterial species indicated that the presence of blood phagocytes had little or no effect on bacterial numbers.
The Different Vascular Patterns of Slime Glands in the Hagfishes, Myxine glutinosa Linnaeus and Eptatretus stouti Lockington A Scanning Electron Microscope Study of Vascular Corrosion Casts*
Authors: Lametschwandtner A. , Lametschwandtner U. , Patzner R. A. 
Published: April 2010

AbstractThe vascular patterns of the epidermally derived slime glands of the Atlantic hagfish, Myxine glutinosa, and of the Pacific hagfish, Eptatretus stouti, have been studied by scanning electron microscopy of vascular corrosion casts. In Myxine a simple two‐dimensional vascular network sheaths the slime glands, while in Eptatretus there is also a great number of capillary loops of different lengths arising from the sheathing network and extending into the interior of the glands. These basic differences in slime glands vascular patterns are thought to reflect substantially different physiological behaviour of the slime glands in Myxine and Eptatretus.
Self‐Inhibition of Egg Laying in Physa sp. (A Freshwater Pulmonate)
Authors: Chaudhry M. Asghar 
Published: April 2010

AbstractFactors affecting the fecundity of Physa sp. were studied in the laboratory. Aging of the culture medium resulted in a significant decline in oviposition of this snail species. Changes in ionic levels of the rearing water did not seem to affect egg laying under the experimental conditions. Conspecific snail‐conditioned water and faecal homogenates to some extent effectively inhibited oviposition, but spinach infusion had no such effect. The results are consistent with the suggestion that some sort of oviposition inhibitor(s) is released by the snails in the culture water. The inhibitor compound(s) is denatured on boiling or after incubation with a protease.
Colony Growth Pattern in Electra pilosa (Linnaeus) and Comparable Encrusting Cheilostome Bryozoans
Authors: Silén Lars 
Published: April 2010

AbstractColony growth pattern is described in E. pilosa, an abundant cheilostome bryozoan commonly found as an epiphyte of Laminaria. Each zooid has 4 potential budding loci—one distal, two lateral and one proximal. The ancestrula buds daughter zooids from all of these loci; the two lateral buds appear first, followed by the distal bud and, after a long delay, the proximal bud. The laterally budded zooids curve inwards as they grow to form a triad with their distally budded sibling zooid. ‘Mature’ multiserial colonies growing on flat substrata consist of a series of radially diverging sectors. Each sector has an axis, generally of 3 parallel rows of zooids, flanked by wings consisting of rows of zooids originating as lateral buds from the section axis which infills the area between the axes. Occasional colonies occur with uniserial or semiuniserial growth patterns. These resemble colonies of the obligatory uniserial species Pyripora catenularia and poorly fed colonies of the related Conopeum tenuissimum, which is normally multiserial like E. pilosa. The ‘composite multiserial’ colonies of E. pilosa differ in several respects from ‘unitary multiserial’ colonies characteristic of most sheet‐like cheilostomes, including the well‐known Membranipora membranacea. Composite and unitary multiserial growth patterns may have evolved independently from uniserial ancestors.
Anatomy and Ultrastructure of Ventral Pharyngeal Organs and their Phylogenetic Importance in Polychaeta (Annelida). IV. The Pharynx and Jaws of the Dorvilleidae
Authors: Purschke Günter 
Published: April 2010

AbstractAn anatomical and ultrastructural investigation of the ventral pharyngeal organ, jaws and replacement of jaws was carried out in Ophryotrocha gracilis and Protodorvillea kefersteini (Dorvilleidae). The pharynx exhibits the following features: jaw apparatus present, consisting of paired mandibles and rows of maxillary plates, the latter are fused to form a single piece; cuticular jaws electron‐dense, in P. kefersteini with collagen fibres; muscle bulbus solid, composed of muscle cells only; parallel running myofilaments, centrally located mitochondria and nuclei, bulbus epithelium containing the mandibles and gland cells, maxillary plates lying on folds corresponding to a tongue‐like organ, connected with mandibles by longitudinal investing muscles; numerous gland cells not united to distinct salivary glands. Development of jaw replacements occurs in epithelial cavities beside the functional maxillae. Shape of maxillary plates is preformed by microvilli carrying cell processes. Maxilloblasts change their shape during the development. Synapomorphic structures occurring in ventral pharyngeal organs of other species outside the Eunicea are not present and even the closely related Dinophilidae exhibit a completely different pharyngeal organ. Therefore, convergent evolution of these organs is the most probable explanation. These findings do not agree with the hypothesis of the homology of the ventral pharyngeal organs in the Polychaeta.
Energetics of Growth in a Temperate Zone Toad, Bufo bufo: Effects of Growth Hormone
Authors: Jørgensen C. Barker , Wind‐Larsen H. 
Published: April 2010

AbstractYoung toads were kept on a diet of meal‐worms and their growth was followed in terms of gains in organic matter and its constituents, protein, fat and glycogen. Growth hormone increased the yield and the retention of protein. Presumably, growth hormone stimulated growth indirectly through increased food intake and growth rate and not by affecting metabolic efficiency. The increases in body matter, expressed as mass, protein and nonprotein matter, were linearly correlated with food intake. In energetic terms about 60% of caloric equivalents ingested in excess of maintenance requirements were retained as body mass. At an absorption efficiency of 90% this amounted to an energetic cost of growth corresponding to one third of the absorbed food above the maintenance requirements.
An Angiocardiographic Analysis of the Central Circulation in the Air Breathing Teleost Channa argus
Authors: Andresen J.H. , Ishimatsu A. , Johansen K. , Glass M.L. 
Published: April 2010

AbstractThe unique anatomy of the double ventral aorta outflow system in the air breathing teleost Channa argus (Ophiocephalus) showing an anterior and posterior ventral aorta is described. The marked trabeculation of the ventricle and bulbus arteriosus and the arrangement of central veins are used as a basis for the hypothesis that Channa may selectively channel the well oxygenated blood draining the air breathing organs via the anterior cardinal vein to the posterior ventral aorta, which forms the systemic arterial circulation. An angiocardiographic technique was used to test this hypothesis, as well as to delineate the functional role of the heart chambers in the cardiac cycle. No reflux of contrast to the sinus venosus during atrial filling and no ventricular filling before atrial contraction were apparent, which makes the atrium the main determinant of the ventricular end‐diastolic volume. Ventricular contraction left a small or no residual volume. The ventricular ejectate was initially nearly completely absorbed by the very elastic bulbus arteriosus, acting as a pressure chamber (Windkessel) stabilizing and prolonging ventral aortic blood flow. Contrast medium was not selectively passed from the anterior cardinal vein to the posterior ventral aorta. However, the diameter of this vessel and its density of contrast were greater than in the anterior aorta, suggesting a preference for a greater blood flow from the air breathing organ through the heart to the posterior aorta.
Notes on Some Annexa Oculi in the Osteolepiform Freshwater Fish Eusthenopteron foordi from the Upper Devonian Escuminac Formation of Miguasha, Eastern Canada
Authors: Bjerring Hans C. 
Published: April 2010

AbstractThe orbit of the Upper Devonian piscine osteolepipod Eusthenopteron foordi has a distinct endocranial depression postero‐ventrally at the base of the basipterygoid process and lateral to the hypophysis. Compared with what is known of extant osteolepipods, this depression is a myodomus retractricis bulbi. From the evidence of this myodome for attachment of retractor bulbi musculature, the hypothesis is presented that Eusthenopteron foordi had a palpebra tertia and, as a corollary, that it also had a musculus levator bulbi, a glandula palpebrae tertiae and a ductus nasolacrimalis. These annexal eye structures would have made it possible for this pulmonate fish to leave the water to bask without being dazzled by sunlight.
Histochemical Investigations of Tardigrada. IV. Alkaline Phosphatase (ALP), Aminopeptidase (AMP) and Gonad Development in Eutardigrades
Authors: Raineri Margherita 
Published: April 2010

AbstractIn tardigrades of the genus Macrobiotus histochemically localized alkaline phosphatase (ALP) and aminopeptidase (AMP) are taken as markers of absorptive/secretory cells. The enzyme reaction intensity is also related to different metabolic activities of the body tissues and compared with other histochemical and histological features of the cells. ALP and AMP distribution pattern is investigated in the Malpighian tubules, the gut, ovary, testicle and the storage and epidermal cells during female and male gonad development. The results strongly support the hypothesis that the Malpighian tubules are osmoregulatory‐excretory organs and may also perform secretory functions. They show morpho‐functional variations which are related to sexual maturity and differ in the female and the male: possible physiological roles are discussed. In the female all the tissues here examined undergo changes in size, enzyme activities and other features that show a relationship with phases of both oogenesis and molt: a physiological explanation is suggested that takes into account previously obtained evidence of neuroendocrine regulation. In the male the stages of testicle maturity and molt seem to be independent of each other and the changes of the body tissues found in the female are less or not evident.
Lymphoid Components in the Branchial Cavernous Body of the Ammocoete of Petromyzon marinus
Authors: Ardavin C.F. , Zapata A. 
Published: April 2010

AbstractThe cavernous body of the ammocoetes of the anadromous sea lamprey Petromyzon marinus was ultrastructurally analyzed with special emphasis on its lymphoid components. It is a vascular structure differentiated from the afferent artery of each gill filament and contains a specialized phagocytic endothelial cell, named the cavernous body (CB) cell. In the vascular spaces of the cavernous body there occur numerous lymphoid cells, including lymphocytes, lymphoblasts, mature and developing plasma cells and large macrophages, which make contact with the CB cells. The role of these cells is discussed as to the suggested functions of the cavernous body in the defence mechanisms of lampreys.
Calcareous Concretions and Non‐Calcified Hooks in the Body Wall of Nemertean Worms
Authors: Strieker Stephen A. , Cavey Michael J. 
Published: April 2010

AbstractTwo types of refractile inclusions in the integument of nemertean worms have been studied by X‐ray microanalysis and electron microscopy. The body wall of Tetrastemma bilineatum contains ovoid concretions that are 10–20 μm long. Qualitative X‐ray microanalyses indicate that the concretions are composed of calcium, phosphorus, barium and perhaps magnesium and sodium. In Zygonemertes sp. and Z. virescens minute hook‐like structures occur throughout the epidermis. The hooks develop by one week post‐fertilization and appear to be non‐calcified in both larvae and adults. Each hook is formed within a large vacuole and consists of several fused subunits. The subunits lack well defined cortical and medullary regions and seem to be produced by the rough endoplasmic reticulum of the epidermal secretory cell. The possible relationships between the calcareous concretions and proboscidial stylets of nemerteans are discussed and the structure of the integumentary hooks is compared to that of rhabdite‐like bodies secreted by other invertebrates.
The Cloaca and Spermatheca of the Female Smooth Newt, Triturus vulgaris L. (Amphibia: Urodela: Salamandridae)
Authors: Verrell Paul A. , Sever David M. 
Published: April 2010

AbstractThe anatomy and histology of the cloaca and spermatheca of 13 female smooth newts (Triturus vulgaris) were studied by light microscopy. The cloaca consists of a short, anterior tube (which receives the oviducts), which opens into a larger, more posterior chamber. The spermatheca, which is the only gland in the cloaca, consists of a mass of exocrine, acinar tubules which empty individually and dorsolaterally into the posterior part of the cloacal tube and all but the most posterior part of the cloacal chamber. Stored sperm are most abundant in the spermathecal tubules during the peak of the breeding season (in May and June); during their period of storage, the sperm do not appear to make intimate contact with the epithelial cells lining the spermathecal tubules. Longterm storage of viable sperm from one breeding season to the next is probably absent in the smooth newt. Sperm storage by and multiple insemination of females both occur in this species and are necessary preconditions for competition between the sperm of different males for the fertilization of eggs. However, sperm competition has not been demonstrated in the smooth newt.
Effect of social environment on the proctodaeal glands of Microtus agrestis L.
Authors: Khan Tasneem Y. , Stoddart D. Michael 
Published: April 2010

AbstractThe effect of social environment on the proctodaeal glands of male Microtus agrestis L. was assessed by examining a number of physical parameters of the glands, as well as of the testes and of the blood, following a range of socialisation treatments. Social isolation depresses glandular development; vole odour from the stock room does not restore gland size. Socialisation with members of the opposite sex restores gland size, but replacement of females twice a week is less effective than constancy of partner. The glands respond to the level of blood testosterone, but glandular development appears to be heavily influenced by other factors.
Blood Vessels and Related Structures in the Gill Bars of Glossobalanus minutus (Enteropneusta)
Authors: Pardos Fernando , Benito Jesús 
Published: April 2010

AbstractThe branchial circulatory system of Glossobalanus minutus (Enteropneusta) is investigated by means of transmission electron microscopy. Primary gill bars, or septa, have a single blood vessel longitudinally located along the outer edge of the bar. Secondary gill bars, or tongue bars, show a vessel in their inner, pharyngeal edge. The walls of both vessels are made up of the basement membranes of surrounding epithelia, lacking an endothelium. No definite limits between the vessel lumen and the skeletal rods inside the bars can be seen. Furthermore, the blood seems to penetrate into the rods of both primary and secondary gill bars. In the secondary bars such a phenomenon gives rise to the so‐called ‘lateral vessels’ reported in the light microscopical literature. The significance of these observations is discussed, with special reference to the gill circulatory system of amphioxus, which seems to be strongly similar from a morphological and ultrastructural point of view.
Surface Markers on the Haemocytes of the Freshwater Snail Planorbarius corneus (L.) (Gastropoda, Pulmonata)
Authors: Ottaviani Enzo 
Published: April 2010

AbstractThe present study probes the occurence of specific components associated with haemocyte surface membranes of Planorbarius corneus. The positive response to PHA. anti‐HLADR and other markers are discussed and possible resemblances with the T cells examined.
The Ultrastructure of the Endocrine Pancreas of the Grass Lizard, Mabuya quinquetaeniata*
Authors: El‐Salhy Magdy , Grimelius Lars 
Published: April 2010

AbstractFour endocrine cell types were identified ultrastructurally in the pancreas of the grass lizard, Mabuya quinquetaeniata. These cells were similar in shape, location and frequency to the previously described B‐, A‐, D‐ and PP‐cells. The secretory granules of the B‐cells were round or oval in profile, with an internal core of variable shape. The mean diameter of the B‐cell granules was 780 nm (range 350–1000 nm). The A‐cell granules were round, oval or irregular in shape and highly electron dense, with a narrow electron lucent space between the core and the limiting membrane. The mean diameter of these granules was 450 nm (range 200–750 nm). The D‐cell granules were round, oval or irregular and of moderate electron density, with an average diameter of 340 nm (range 200–500 nm). The limiting membrane was closely apposed to the core or separated from it by a narrow lucent space. PP‐cell granules were round with high electron density and with a narrow space between the core and the limiting membrane, and their average diameter was 150 nm (range 50–350 nm); these secretory granules accumulated at the cytoplasmic process. Tracing of the cytoplasmic processes of PP‐cells in serially cut ultrathin sections revealed that most of these processes ended in the vicinity of blood capillaries, indicating that the PP‐cells were endocrine rather than paracrine.
Ultrastructural Observations on the Epidermis of Xenoturbella bocki Westblad, 1949; With a Discussion of Epidermal Cytoplasmic Filament Systems of Invertebrates
Authors: Pedersen Knud Jørgen , Pedersen Lars Ryde 
Published: April 2010

AbstractThe highly complex epidermis of Xenoturbella bocki has been studied, mainly employing transmission electron microscopical and histochemical methods. The epidermal organization is described to best advantage in terms of the various cell types present, their intricate interrelationships and their interaction with the highly developed subepidermal membrane complex (SMC). The epidermis is composed mainly of ciliated epidermal supporting cells, at least two types of gland cells (one dominant mucous type with basophilic, alcian blue‐positive granules; another possessing acidophilic, PAS‐positive granules), several types of nerve cells present in the intraepidermal nerve layer and, finally, some peculiar basally arranged ‘pillow cells’. Junctional structures are sparsely developed. The epidermal supporting cell is provided with a distinct cell web, but diagnostic for this cell type is the presence of a very prominent single supporting fibre (SF) composed of supporting filaments. Distally some of these filaments may terminate on the tapering proximal ends of ciliary rootlets, a highly unusual phenomenon. Basally the SF is attached to the SMC in a complex arrangement. The possible relationship of the supporting filaments to cytoskeletal intermediate filaments is discussed. The SF is compared to other cytoplasmic filament systems in mammals and various invertebrates. The ultrastructural organization of Xenoturbella is now fairly well understood, nevertheless, our conclusion must be that it is still not possible to assign an appropriate place for this animal in the systematic‐phylogenetic system.
Tail Regeneration in Normal, Blinded and Pinealectomized Gekkonid Lizards, Hemidactylus flaviviridis, Exposed to Four Different Light Conditions During Three Seasons (Temperatures)
Authors: Ramachandran A. V. , Ndukuba Patrick I. 
Published: April 2010

AbstractTail regeneration was followed for 60 days in 1470 normal (NL), blinded (BL) and pinealectomized (PX) gekkonid lizards, Hemidactylus flaviviridis, fed on cockroaches ad libitum and exposed to continuous light of high intensity (2500 lux), continuous light of low intensity (638 lux), 12 h of light (high intensity) and 12 h of darkness and continuous darkness in summer (March – May; cage temperature 30°C) monsoon (August – October; cage temperature 26°C) and winter (November – January; cage temperature 17°C) seasons. A comparative assessment of the new growth (regenerate) showed that the initiation of regeneration, the daily growth, the total length of tail replaced at the end of regeneration and the total percentage replacement of the lost (autotomized) tails were all enhanced by continuous light and depressed by continuous darkness. Furthermore, there was no significant difference between any of the parameters in NL and BL Hemidactylus; however, PX lizards generally showed retardation in the regeneration process. Seasonal differences in tail regeneration were noted—the best regenerative performance was obtained during the summer months and the worst during the winter months, with the regenerative performance during the monsoon season in between. Thermal and photoperiodic influences on tail regeneration in lizards are discussed.
Reproductive Cycle and Developmental Processes During Embryogenesis of Clavularia hamra (Cnidaria, Octocorallia)
Authors: Benayahu Y. 
Published: April 2010

AbstractClavularia hamra Gohar, 1948 is a common octocoral on the reefs of the Gulf of Eilat (northern Red Sea). Reproductive biology of C. hamra was studied for two years. Direct observations of spawning were conducted in situ and in aquaria. Cleavage of eggs and further embryo metamorphosis into mature planulae were examined by scanning electron microscopy and histological sections.Clavularia hamra is dioecious. Young oocytes appear annually in September, gradually grow in size and attain maturity within 11 months. The main spawning event of the population is highly synchronized, occurring on a single night each year between the last quarter and the new moon in mid summer.The released orange eggs are held together by mucus and remain attached amongst the polyps on the outside of the female colonies. Twelve hours after spawning, the young embryos have blastomeres of equal size with numerous microvilli on their external surface. Due to unequal cleavage, bizarre embryos are also formed. By 48 h a blastopore is visible, indicating that a gastrula is developing. Eight days after spawning mature planulae are observed.The external mode of embryo development on the surface of the parent colony reduces dispersal of the planulae. However, this reproductive feature enhances formation of locally dense populations of C. hamra, with distinct habitat preferences.