bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of the avian coelom with associated vitelline blood circulation by Rauber's sickle derived junctional endoblast and its fundamental role in heart formation
Authors: Callebaut Marc , Van Nueten Emmy , Bortier Hilde , Harrisson Fernand 
Published: December 2003

AbstractIn histological sections through chicken blastoderms of different ages we describe the temporospatial relationship between junctional endoblast, the formation of blood islands (appearing first from a peripherally migrating mesoblastic blastema), and the formation of coelomic vesicles developing later in/and from a more superficially extending mesoblastic blastema (coelomic mesoblast). After unilateral removal of the Rauber's sickle‐derived junctional endoblast in early streak blastoderms (stage 2–4; Vakaet [1970] Arch Biol 81:387–426) and culture to stage 11 (Hamburger and Hamilton [1951] J Morphol 88:49–92), we observed that the early formation of the coelomic cavity was locally or totally disturbed in the operated area. Besides the simultaneous absence of blood islands, the coelomic vesicles did not form normally. Instead of regularly aligned coelomic vesicles, progressively forming the coelomic cavity by fusion, some voluminous irregular cavities appeared. Thus, the extent of the coelomic cavity was greatly reduced and the operated side was considerably smaller than the unoperated side. Furthermore, in the youngest operated blastoderms the cranial portion of the involved coelomic cavity (hemipericardial cavity) exhibited rudimentary development and usually did not reach the region of the foregut endoderm. This resulted in the absence of the myoepicardium and associated endocardium at this side. In another experiment, after removal of the junctional endoblast at one side of the chicken blastoderm, a fragment of quail junctional endoblast was placed isotopically. This resulted, after further in vitro culture, in the restoration of the formation of coelomic vesicles and accompanying subjacent blood islands in the immediate neighborhood of the apposed quail junctional endoblast. Also, the pericardium and primary heart tube developed normally. Similarly, by using the quail‐chicken chimera technique, we demonstrated that the splanchnic mesoderm cells of the pericardium develop in intimate association with the most cranial part of the junctional endoblast (derived from the Rauber's sickle horns). Our experiments indicate that the coelom and, in particular, the pericardium and primary heart tube form progressively (in time and space) under the inductory influence of Rauber's sickle and junctional endoblast. J. Morphol. 259:21–32, 2004. © 2003 Wiley‐Liss, Inc.
Blubber development in bottlenose dolphins (Tursiops truncatus)
Authors: Struntz D.J. , McLellan W.A. , Dillaman R.M. , Blum J.E. , Kucklick J.R. , Pabst D.A. 
Published: December 2003

AbstractBlubber, the lipid‐rich hypodermis of cetaceans, functions in thermoregulation, buoyancy control, streamlining, metabolic energy storage, and locomotion. This study investigated the development of this specialized hypodermis in bottlenose dolphins (Tursiops truncatus) across an ontogenetic series, including fetuses, neonates, juveniles, subadults, and adults. Blubber samples were collected at the level of the mid‐thorax, from robust specimens (n = 25) that stranded along the coasts of North Carolina and Virginia. Blubber was dissected from the carcass and its mass, and the depth and lipid content at the sample site, were measured. Samples were prepared using standard histological methods, viewed by light microscopy, and digital images of blubber captured. Images were analyzed through the depth of the blubber for morphological and structural features including adipocyte size, shape, and numbers, and extracellular, structural fiber densities. From fetus to adult, blubber mass and depth increased proportionally with body mass and length. Blubber lipid content increased dramatically with increasing fetal length. Adult and juvenile blubber had significantly higher blubber lipid content than fetuses, and this increase was reflected in mean adipocyte size, which increased significantly across all robust life history categories. In juvenile, subadult, and adult dolphins, this increase in cell size was not uniform across the depth of the blubber, with the largest increases observed in the middle and deep blubber regions. Through‐depth counts of adipocytes were similar in all life history categories. These results suggest that blubber depth is increased during postnatal growth by increasing cell size rather than cell number. In emaciated adults (n = 2), lipid mobilization, as evidenced by a decrease in adipocyte size, was localized to the middle and deep blubber region. Thus, in terms of both lipid accumulation and depletion, the middle and deep blubber appear to be the most metabolically dynamic. The superficial blubber likely serves a structural role important in streamlining the animal. This study demonstrates that blubber is not a homogeneous tissue through its depth, and that it displays life history‐dependent changes in its morphology and lipid content. J. Morphol. 259:7–20, 2004. © 2003 Wiley‐Liss, Inc.
Effects of noradrenaline administration on the interrenal gland of the newt, Triturus carnifex: Evidence of intra‐adrenal paracrine interactions
Authors: Capaldo A. , Gay F. , Valiante S. , Laforgia V. , Varano L. 
Published: December 2003

AbstractThe existence of paracrine control of steroidogenic activity by adrenochromaffin cells in Triturus carnifex was investigated by in vivo noradrenaline (NA) administration. The effects were evaluated by examination of the ultrastructural morphological and morphometrical features of the tissues as well as the serum levels of aldosterone, NA, and adrenaline (A). In March and July, NA administration increased aldosterone release (from 187.23 ± 2.93 pg/ml to 878.31 ± 6.13 pg/ml in March; from 314.60 ± 1.34 pg/ml to 622.51 ± 2.65 pg/ml in July) from steroidogenic cells. The cells showed clear signs of stimulation, as evidenced by a strong reduction of lipid content. Moreover, NA administration decreased the mean total number of secretory vesicles in the chromaffin cells in March (from 7.24 ± 0.18 granules/μ2 to 5.57 ± 1.88 granules/μ2) and July (from 7.74 ± 0.74 granules/μ2 to 6.04 ± 1.13 granules/μ2). In March, however, when T. carnifex chromaffin cells contain both catecholamines, NA (3.88 ± 0.13 granules/μ2) and A (3.36 ± 0.05 granules/μ2) in almost equal quantities, NA administration reduced A content (1.29 ± 1.04 granules/μ2) in the chromaffin cells, enhancing adrenaline secretion (from 681.27 ± 1.83 pg/ml to 1527.02 ± 2.11 pg/ml). In July, when the chromaffin cells contain almost exclusively NA granules (NA: 7.42 ± 0.86 granules/μ2; A: 0.32 ± 0.13 granules/μ2), NA administration reduced the number of NA granules (5.45 ± 1.10 granules/μ2), thereby increasing noradrenaline release from the chromaffin cells (from 640.19 ± 1.65 pg/ml to 1217.0 ± 1.14 pg/ml). The results of this study indicate that NA influences the steroidogenic cells, eliciting aldosterone release. Noradrenalin effects on the chromaffin cells, increase of NA or A secretion, according to the period of chromaffin cell functional cycle, may be direct and/or mediated through the steroidogenic cells. The existence of intra‐adrenal paracrine interactions in T. carnifex is discussed. J. Morphol. 259:33–40, 2004. © 2003 Wiley‐Liss, Inc.
Pattern and rate of ovary differentiation with reference to somatic development in anuran amphibians
Authors: Ogielska Maria , Kotusz Agnieszka 
Published: December 2003

AbstractThe rate of somatic development of anuran amphibians is only roughly correlated with the rate of gonad differentiation and varies among species. The somatic stage of a tadpole often does not reflect its age, which seems to be crucial for gonad differentiation rate. We compared the morphology and differentiation of developing ovaries at the light and electron microscopy level, with reference to somatic growth and age of a female. Our observations were performed on 12 species of six families (Rana lessonae, R. ridibunda, R. temporaria, R. arvalis, R. pipiens, R. catesbeiana, Bombina bombina, Hyla arborea, Bufo bufo. B. viridis, Xenopus laevis, Pelobates fuscus) and compared with the results obtained by other authors. This allowed us to describe the unified pattern of anuran female gonad differentiation. Ovary differentiation was divided into 10 stages: I–III, undifferentiated gonad; IV, sexual differentiation; V, first nests of meiocytes; VI, first diplotene oocytes; VII–IX, increasing number of diplotene oocytes and decreasing number of oogonia and nests; X, fully developed ovary composed of diplotene oocytes with rudimental patches of oogonia. We distinguished three types of ovary differentiation rate: basic (most species), retarded (genus Bufo), and accelerated (green frogs of the subgenus Pelophylax genus Rana). J. Morphol. 259:41–54, 2004. © 2003 Wiley‐Liss, Inc.
A pair of rosette glands in the embryo and zoeal larva of an estuarine crab Sesarma haematocheir, and classification of the tegumental glands in the embryos of other crabs
Authors: Ikeda Hideki , Hirano Yuriko , Saigusa Masayuki 
Published: December 2003

AbstractA pair of rosette glands (one of the tegumental glands in crustaceans) is present at the root of the dorsal spine of the thorax in mature embryos of the estuarine crab Sesarma haematocheir. Each rosette gland is spherical, 45–50 μm in diameter. This gland consists of three types of cells: 18–20 secretory cells, one central cell, and one canal cell. The secretory cells are further classified into two types on the basis of the morphology of secretory granules. There are 17–19 a cells, and only one b cell per rosette gland. An a cell contains spherical secretory granules of 2–3 μm in diameter. The granules are filled with highly electron‐dense materials near the nucleus but have lower electron‐density near the central cell. The secretory granules contained in the b cell have an irregular shape and are 1–1.5 μm in diameter. The density of the materials in the granules is uniform throughout the cytoplasm. The secretory granules contained in both the a and b cells are produced by the rough endoplasmic reticulum. Materials in the granules are exocytotically discharged into the secretory apparatus inside the secretory cell, sent to the extracellular channels in the central cell, and secreted through the canal cell. The rosette gland can be distinguished from the epidermal cells 2 weeks after egg‐laying and the gland matures just before hatching. Materials produced by this gland are secreted after hatching and secretion continues through five stages of zoeal larvae. These rosette glands were never found in the megalopal larva. Rosette glands are found in the embryos of Sesarma spp. and Uca spp. In other crabs, tegumental glands are also found at the same position as in the embryo of S. haematocheir, but the fine structure of their glands is largely different from that of the rosette gland. On the basis of the morphology of secretory cells (a–g cell types), the tegumental glands of a variety of crab embryos can be classified into four types, including rosette glands (type I–IV). The function of these tegumental glands is not yet known, but different types of the gland seem to reflect the phylogeny of the crabs rather than differences of habitat. J. Morphol. 259:55–68, 2004. © 2003 Wiley‐Liss, Inc.
Roles of actin networks in peristaltic squeezing of sperm bundles in Bombyx mori
Authors: Sahara Ken , Kawamura Naoko 
Published: December 2003

AbstractTwo types of sperm are produced in the silkworm, Bombyx mori. Nucleate eupyrene sperm is an ordinary sperm that contributes to fertilization, while anucleate apyrene sperm is considered to play important roles in assisting eupyrene sperm. At the very late stage of spermatogenesis, a phenomenon called “peristaltic squeezing” occurs in both types of sperm, whereby cytoplasm of the eupyrene and nuclei of the apyrene sperm are discarded from the posterior end, forming matured sperm. In this study, rhodamine‐phalloidin staining for actin was applied to sperm bundles. Before the start of peristaltic squeezing, actin filament networks are spread on the cyst cells and constrictions by the networks appear in several places of the bundles. Actin particles, which are later recognized as circlets, are localized within the bundles. Squeezing action by the networks occurs from the anterior region and transfers toward the posterior, eliminating cytoplasm together with circlets from the posterior end. It seems that actin filaments contribute to the peristaltic squeezing of the sperm bundles in Bombyx mori. J. Morphol. 259:1–6, 2004. © 2003 Wiley‐Liss, Inc.
Ovarian histology of the placentotrophic Mabuya mabouya (Squamata, Scincidae)
Authors: Gómez Duperly , Ramírez‐Pinilla Martha Patricia 
Published: December 2003

AbstractOvarian structure and folliculogenesis of females at different reproductive stages are described for the viviparous placentotrophic lizard Mabuya mabouya. The small ovaries have a thin wall formed by the ovarian epithelium and a thin tunica albuginea. One to two germinal beds that contain numerous oogonia and developing primordial follicles are derived from the ovarian epithelium and are next to the ovarian hilum. The ovarian cortex contains follicles at different stages of development, corpora lutea, and atretic follicles. The yolk nucleus and Balbiani complex were not evident in the ooplasm of previtellogenic follicles. The follicular epithelium of these follicles is polymorphic, as in other species of Squamata, but the larger cells are spherical and monolayered rather than pyriform. The zona radiata of the preovulatory follicles is less developed than in lecithotrophic species. These features suggest a decrease in metabolic and absorptive processes during follicular growth. In preovulatory follicles (1.5–1.8 mm diameter), primordial yolk vacuoles and small cortical granules are deposited in the ooplasm instead of fatty yolk platelets, so that only one stage of vitellogenesis is observed. Polyovular atretic follicles occur in some females. Follicular atresia is minimal for preovulatory follicles, but is more frequent in follicles with polymorphic epithelia. In the corpus luteum, the luteal tissue is formed from granulosa cells and luteolysis occurs during the late gastrula – late neurula embryonic stages. Thus, the maintenance of gestation from the pharyngula to preparturition stages seems to be related to secretion of extraluteal progesterone, possibly of placental origin. These observed ovarian features are related to the high degree of placental complexity of this species and show that the evolution of advanced placentotrophy in species of this lineage has been accompanied by concomitant changes in ovarian function. J. Morphol. 259:90–105, 2004. © 2003 Wiley‐Liss, Inc.
Studies of male sexual tubes in hermit crabs (crustacea, decapoda, anomura, paguroidea). I. Morphology of the sexual tube in Micropagurus acantholepis (Stimpson, 1858), with comments on function and evolution
Authors: Tudge Christopher , Lemaitre Rafael 
Published: December 2003

AbstractThe external morphology and internal structure of the male sexual tube of the hermit crab Micropagurus acantholepis, a member of the family Paguridae from Australian waters, is described in detail using histological thick sectioning and scanning and transmission electron microscopy techniques. This is the first in‐depth study of a sexual tube in the Paguroidea, a group where a remarkable number of genera (55.9% in the family Paguridae) with species having these intriguing sexual structures are known. In M. acantholepis a sexual tube is present on the left side, whereas only a gonopore is present on the right side. The tube is used for the delivery of spermatophores to the female and consists of a sheath of cuticular origin surrounding an internal, functional extension of the posterior vas deferens. Pedunculate spermatophores were observed within the lumen and partially extruding from the terminal opening of the tube in preserved specimens. The tube protrudes from the left coxa of the fifth pereopod as an elongate 3‐mm‐long, hollow, coiled structure with a terminal opening. Exteriorly the tube consists of a conspicuous thick chitinous cuticular ridge throughout its length, and a thin chitinous cuticle with sparse, regularly arranged simple setae. Interior to the cuticle, the tube contains loose connective tissue, secretory cells, oblique muscle, circular muscle, and epithelial cells. The latter cells line a central lumen that runs the length of the sexual tube. The morphology, cellular composition, and function of the tube are discussed. J. Morphol. 259:106–118, 2004. © 2003 Wiley‐Liss, Inc.
Modelling paired categorical outcomes in clinical trials
Authors: Dmitrienko Alex 
Published: December 2003

AbstractThe goal of this paper is to discuss methods for testing the homogeneity of treatment‐induced changes in trials with paired categorical responses. Widely used marginal homogeneity tests ignore the information contained in concordant pairs of observations and become highly underpowered for configurations of parameters encountered in real trials. This paper considers models for paired binary or ordinal outcomes based on both discordant and concordant pairs that provide a natural extension of marginal models. Likelihood‐ratio tests associated with these models are developed and are demonstrated to be at least as powerful as or more powerful than marginal homogeneity tests. The proposed models are easy to fit using standard statistical software. Copyright © 2003 John Wiley & Sons, Ltd.
An improved concordance correlation coefficient
Authors: Liao Jason J. Z. 
Published: December 2003

AbstractIt is often required to compare two measurements in medicine and other experimental sciences. This problem covers a broad range of data, and examples can be found in different industries. In this paper, a new index on measuring agreement is proposed, which is similar to Lin's concordance correlation coefficient but derived from a criterion which is more conceptually appealing and which offers improvements. An example is used to demonstrate the benefit of using the new index. Copyright © 2003 John Wiley & Sons, Ltd.
Possible mechanisms of action of the neutral extract from Bidens pilosa L. leaves on the cardiovascular system of anaesthetized rats
Authors: Dimo T. , Nguelefack T. B. , Tan P. V. , Yewah M. P. , Dongo E. , Rakotonirina S. V. , Kamanyi A. , Bopelet M. 
Published: December 2003

AbstractThe aim of this study was to investigate the hypotensive and cardiac effects of the neutral extract from Bidens pilosa leaves. Intravenous administration of the extract resulted in a biphasic dose‐related hypotensive activity. In normotensive rats (NTR), B. pilosa decreased systolic blood pressure by 18.26%, 42.5% and 30% at doses of 10, 20 and 30 mg/kg, respectively. In spontaneously hypertensive rats (SHR), the decrease in systolic blood pressure was 25.77%, 38.96% and 28.64% at the above doses, respectively. These doses induced hypotension by 27%, 34.13% and 18.73% respectively in salt‐loaded hypertensive rats. In NTR, B. pilosa reduced heart rate by 23.68% and 61.18% at doses of 20 and 30 mg/kg, respectively. The force of contraction of the heart was only affected at 30 mg/kg. The initial phase of hypotensive response was partially inhibited by atropine while propranolol increased this effect. These results suggest that B. pilosa exhibited its ﬁrst hypotensive effects by acting on the cardiac pump efﬁciency and secondly through vasodilation.
Relaxant effects of different fractions of essential oil from Carum copticum on guinea pig tracheal chains
Authors: Boskabady M. H. , Ramazani M. , Tabei T. 
Published: December 2003

AbstractIn previous studies, the relaxant and anticholinergic (functional antagonism), histamine(H1) inhibitory, and xanthine‐like activity effect of Carum copticum have been demonstrated on guinea pig tracheal chains. To investigate the effective component(s) of this plant, responsible for the observed bronchodilatory effect, fractionation of the essential oil from Carum copticum was carried out and the relaxant effects of different fractions were examined in this study. The bronchodilatory effect of different fractions of essential oil from Carum copticum and theophylline in comparison with ethanol was examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1) and 10 µM methacholine in two different conditions including: non‐incubated tissues (group 2) and incubated tissues with 1 µM propranolol and 1 µM chlorpheniramine (group 3). In addition the relaxant effect of carvacrol was also examined on precontracted tracheal chains of guinea pig by 10 µM methacholine (group 4), (for each group, n = 5). In group 1 experiments, only theophylline and fraction 2 showed signiﬁcant relaxant effect compared to that of ethanol. Fraction 2 and 3 of essential oil from carum copticum showed potent and volume (concentration) dependent relaxant effects comparable to that of theophylline in groups 2 and 3 experiments. The relaxant effects of different volumes of these two fractions were signiﬁcantly higher than that of ethanol (p < 0.05 to p < 0.002 ). The volumes of fraction 1 showed relatively small relaxant effects in groups 2 and 3 experiments which were not signiﬁcantly different from that of ethanol. However, the relaxant effect of different volumes of fractions 2 and 3 obtained in group 2 experiments were not signiﬁcantly different from those of group 3 experiments. The volumes of fraction 4 did not show any relaxant effects. In addition volumes of carvacrol also showed comparable relaxant effect with those of fraction 2 and theophylline which was signiﬁcantly greater than that of ethanol. These results indicate that the relaxant effect of essential oil from carum copticum is mainly due to its fraction 2 which is presumably carvacrol and to lesser extent due to fraction 3, and their relaxant effects are not due to anticholinergic or β‐adrenegic stimulatory effects. Copyright © 2003 John Wiley & Sons, Ltd.
Cytotoxicity and antimicrobial activity of goniothalamin isolated from Bryonopsis laciniosa
Authors: Mosaddik M. Ashik , Haque M. Ekramul 
Published: December 2003

AbstractThe cytotoxicity and antimicrobial activity of goniothalamin isolated from Bryonopsis laciniosa was investigated. Goniothalamin showed potent cytotoxicity with LC50 values (5.03 µg/mL) comparable with the reference standard agent, gallic acid. It also showed weak antibacterial and signiﬁcant antifungal activity against a wide range of gram positive and gram negative bacteria and fungi. The antibacterial (minimum inhibitory concentration) effect against Bacillus cereus and Shigella shiga was found to be 64 µg/mL. Copyright © 2003 John Wiley & Sons, Ltd.