bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fish gill morphology: inside out
Authors: Wilson Jonathan M. , Laurent Pierre 
Published: August 2002

AbstractIn this short review of fish gill morphology we cover some basic gross anatomy as well as in some more detail the microscopic anatomy of the branchial epithelia from representatives of the major extant groups of fishes (Agnathans, Elasmobranchs, and Teleosts). The agnathan hagfishes have primitive gill pouches, while the lampreys have arch‐like gills similar to the higher fishes. In the lampreys and elasmobranchs, the gill filaments are supported by a complete interbranchial septum and water exits via external branchial slits or pores. In contrast, the teleost interbranchial septum is much reduced, leaving the ends of the filaments unattached, and the multiple gill openings are replaced by the single caudal opening of the operculum. The basic functional unit of the gill is the filament, which supports rows of plate‐like lamellae. The lamellae are designed for gas exchange with a large surface area and a thin epithelium surrounding a well‐vascularized core of pillar cell capillaries. The lamellae are positioned for the blood flow to be counter‐current to the water flow over the gills. Despite marked differences in the gross anatomy of the gill among the various groups, the cellular constituents of the epithelium are remarkably similar. The lamellar gas‐exchange surface is covered by squamous pavement cells, while large, mitochondria‐rich, ionocytes and mucocytes are found in greatest frequency in the filament epithelium. Demands for ionoregulation can often upset this balance. There has been much study of the structure and function of the branchial mitochondria‐rich cells. These cells are generally characterized by a high mitochondrial density and an amplification of the basolateral membrane through folding or the presence of an intracellular tubular system. Morphological subtypes of MRCs as well as some methods of MRC detection are discussed. © 2002 Wiley‐Liss, Inc.
Tissue interactions and antlerogenesis: New findings revealed by a xenograft approach
Authors: Li Chunyi , Harris A. John , Suttie James M. 
Published: August 2002

AbstractTissue interactions play a pivotal role in organogenesis. Here we describe a xenograft approach to investigate how heterotypic tissue interactions control antler formation in deer. Deciduous antlers grow from the apices of permanent protuberances, called pedicles. Histogenesis of pedicles depends on the antlerogenic periosteum (AP). Pedicles and growing antlers are made up of interior osseocartilage (a mixture of bone and cartilaginous tissue) and exterior skin. In a previous study we hypothesised that pedicle growth may result from mechanical interactions between the interior and exterior components whereas antler generation from a pedicle would involve molecules communicating between the interior and exterior components. To test this hypothesis, we subcutaneously transplanted AP of red deer (Cervus elaphus), either alone or with future pedicle skin, onto nude mice. The results showed that under the nude mouse skin, subcutaneously xenografted AP alone not only could form pedicle‐shaped protuberances but also could differentiate into well‐organised pedicle‐like structures. The overlying mouse skin accommodated the expansion of the grafted AP by initial mechanical stretching and subsequent formation of new skin. Nude mouse skin was not capable of participating in antler tissue formation. However, grafted deer skin together with AP may have successfully rescued this failure after wounding, which highlights the necessity of the specificity of the overlying skin for antler tissue generation. Therefore, we conclude that it is the interaction between the antlerogenic tissue and the overlying skin that results in antlerogenesis: reciprocal mechanical interactions cause pedicle formation, whereas reciprocal instructive interactions induce first antler generation. J. Exp. Zool. 290:18–30, 2001. © 2001 Wiley‐Liss, Inc.
Expression of the human SRY protein during development in normal male gonadal and sex‐reversed tissues
Authors: Salas‐Cortés Laura , Jaubert Francis , Bono María Rosa , Fellous Marc , Rosemblatt Mario 
Published: August 2002

AbstractSex determination in mammals is controlled by the SRY gene located on the Y chromosome. It encodes a protein containing a DNA‐binding and DNA‐bending domain. In spite of recent advances in the identification of the mechanisms that regulate male sex determination in mammals, the expression profile of the SRY protein in normal and sex‐reversed human tissues is not well established. In order to localize the SRY protein and determine its cellular distribution and expression at different stages of development, we prepared monoclonal antibodies (mAb) against the recombinant SRY protein. One of these antibodies, LSRY1.1, recognizes a protein of 27 kDa in total lysates of HeLa SRYB3, a human cell line transfected with the SRY gene under the control of the SV40 promoter. Immunocytochemical analysis in the cell lines shows nuclear localization of the SRY protein. We have studied SRY protein expression in human tissues at different stage of fetal development until adult life and have demonstrated that the SRY protein is located in the nuclei of somatic cells and germ cells in the genital ridge during testis development. After testis determination, it can be detected until the adult stage in both germ cells and Sertoli cells. The presence of the SRY protein was also analyzed in biopsies of gonadal tissues of sex‐reversal patients such as SRY‐positive 46,XX males or SRY‐positive 46,XX true hermaphrodites. SRY protein is detected in the nuclei of Sertoli cells of the testis and in the nuclei of granulosa cells in the ovotestis in these patients and in the nuclei of germ cells of both tissue types. These results suggest a common cellular origin for both Sertoli cells and granulosa cells. J. Exp. Zool. 290:607–615, 2001. © 2001 Wiley‐Liss, Inc.
Glucagon effects on brain carbohydrate and ketone body metabolism of rainbow trout
Authors: Magnoni Leonardo J. , Míguez Jesús M. , Soengas José L. 
Published: August 2002

AbstractThe levels of glycogen in brain, lactate and acetoacetate in brain and plasma, glucose in plasma and the activities of brain key enzymes of glycogen metabolism (glycogen phosphorylase, GPase, glycogen synthetase, GSase), gluconeogenesis (fructose 1,6‐bisphosphatase, FBPase), and glycolysis (6‐phosphofructo 1‐kinase, PFK) were evaluated in rainbow trout, Oncorhynchus mykiss, from 0.5 to 3 hr after intraperitoneal injection of 1 ml/kg–1 body weight of saline alone (controls) or containing bovine glucagon at three different doses: 10, 50, and 100 ng/g–1 body weight. The results obtained demonstrate, for the first time in a teleost fish, the existence of changes in brain carbohydrate and ketone body metabolism following peripheral glucagon treatment. A clear stimulation of brain glycogenolytic potential was observed after glucagon treatment, as judged by the time‐ and dose‐dependent changes observed in brain glycogen levels (up to 88% decrease), and GPase (up to 30% increase) and GSase (up to 42% decrease) activities. In addition, clear time‐ and dose‐dependent increased and decreased levels were observed in brain of glucagon‐treated rainbow trout for lactate (up to 60% increase) and acetoacetate (up to 67% decrease), respectively. In contrast, no significant changes were observed after glucagon treatment in those parameters related to glycolytic/gluconeogenic capacity of rainbow trout brain. Altogether, these in vivo results suggest that glucagon may play a role (direct or indirect) in the regulation of carbohydrate and ketone body metabolism in brain of rainbow trout. J. Exp. Zool. 290:662–671, 2001. © 2001 Wiley‐Liss, Inc.
Characterization of duplicated zebrafish cyp19 genes
Authors: Chiang Evelyn Feng‐Lin , Yan Yi‐Lin , Tong Sok‐Keng , Hsiao Pei‐Hung , Guiguen Yann , Postlethwait John , Chung Bon‐Chu 
Published: August 2002

AbstractThe zebrafish has recently been developed as a good genetic model system. We report here the use of zebrafish to study the regulation of estrogen biosynthesis. The CYP19 gene encodes cytochrome P450 aromatase, which catalyzes the synthesis of estrogens. Two cyp19 genes, termed cyp19a and cyp19b, have been isolated from zebrafish. Sequence comparison shows that Cyp19a and Cyp19b belong to two separate Cyp19 subfamilies. The cyp19a gene is expressed in the ovary, whereas cyp19b is expressed in the brain. The cyp19a and cyp19b genes are located on zebrafish chromosomes LG 18 and 25, respectively. Our data indicate that these gene loci arose through an ancient chromosomal duplication event. The expression of duplicated genes in distinct tissues may have evolutionary significance. J. Exp. Zool. 290:709–714, 2001. © 2001 Wiley‐Liss, Inc.
Histochemical analysis of sperm storage in Helicolenus dactylopterus dactylopterus (Teleostei: Scorpaenidae)
Authors: Muñoz Marta , Koya Yasunori , Casadevall Margarida 
Published: August 2002

AbstractThe bluemouth rockfish, Helicolenus dactylopterus dactylopterus (De la Roche, 1809), is a zygoparous species with internal fertilization. The male urogenital papilla acts as the copulating organ, and the females retain the spermatozoa in their ovaries for up to 10 months. The objective of this study is to extend our knowledge of the mechanisms that allow the sperm to be retained in the ovaries for prolonged periods. To this end, we analyze the histochemical properties of: 1) the epithelium of the testicular sperm duct, 2) the sperm of the males, 3) the internal epithelium of the ovary wall, 4) the ovarian fluid, and 5) the spermatozoa storage crypts of females. The PAS (Periodic acid‐Schiff) and bright Coomassie blue positive reactions of the epithelium of the spermatic duct point to the secretion of polysaccharides and proteins that could promote the bundling of the spermatozoa. The internal epithelium of the ovarian wall secretes polysaccharides, protein, and lipid compounds throughout the storage and spawning period. The acid nature of the ovarian fluid during the storage period may maintain the bundling of spermatozoa when they enter the ovary and may also inhibit sperm motility until the moment of fertilization. The polysaccharide granules that come from the cryptal epithelium into the cavity where spermatozoa are maintained may supply them with nutrients for the storage period. The presence of glucosaminoglycans on the surface of the sperm is probably related to the inhibition of spermatic motility produced by the acidic environment. They are absent in the spermatozoa located in the testicular ducts, relatively scarce in those of the duct of the copulating organ, and abundant in those within the intraovarian cryptal structures. J. Exp. Zool. 292:156–164, 2002. © 2002 Wiley‐Liss, Inc.
Homology and evolutionary novelty in the deployment of extracellular matrix molecules during pigment pattern formation in the salamanders Taricha torosa and T. rivularis (Salamandridae)
Authors: Parichy David M. 
Published: August 2002

AbstractSalamander larvae exhibit a diverse array of pigment patterns shortly after hatching. Previous studies have identified roles for the extracellular matrix and lateral line sensory system in promoting the development of a phylogenetically common pattern of horizontal melanophore stripes. In contrast, salamanders in the genus Taricha exhibit evolutionarily derived pigment patterns and pattern‐forming mechanisms. Taricha torosa larvae exhibit compact melanophore stripes that develop via redundant, lateral line‐independent mechanisms, whereas T. rivularis larvae lack stripes and instead have melanophores uniformly distributed over the flank. In this study, I test roles for candidate patterning molecules of the extracellular matrix in promoting the development of species‐specific pigment patterns in Taricha. I show that tenascin deposition is negatively correlated with melanophore distributions both intraspecifically and interspecifically: this matrix molecule is present where melanophores do not localize in T. torosa and is absent from these same regions where melanophores are abundant in T. rivularis. Embryological manipulations further indicate that transient expression of tenascin in a prospective interstripe region of T. torosa reflects a phylogenetically conserved effect of lateral line development. Finally, anti‐laminin immunoreactivity is negatively correlated with melanophore distributions in T. torosa, and this species exhibits a general retardation of extracellular matrix development that may allow persistent, evolutionarily novel melanophore motility in this species. Together these findings identify tenascin and laminin, or molecules co‐regulated with these matrix components, as candidates for promoting early larval pigment pattern development in Taricha. J. Exp. Zool. (Mol. Dev. Evol.) 291:13–24, 2001. © 2001 Wiley‐Liss, Inc.
Characterisation and expression of Sox9 in the Leopard gecko, Eublepharis macularius
Authors: Valleley Elizabeth M.A. , Cartwright Elizabeth J. , Croft Nirvana J. , Markham Alexander F. , Coletta P. Louise 
Published: August 2002

AbstractSince the discovery of the sex‐determining gene, Sry, a number of genes have been identified which are involved in sex determination and gonadogenesis in mammals. Although Sry is known to be the testis‐determining factor in mammals, this is not the case in non‐mammalian vertebrates. Sox9 is another gene that has been shown to have a male‐specific role in sex determination, but, unlike Sry, Sox9 has been shown to be involved in sex determination in mammals, birds, and reptiles. This is the first gene to be described that has a conserved role in sex determination in species with either chromosomal or environmental sex‐determining mechanisms. Many reptiles do not have sex chromosomes but exhibit temperature‐dependent sex determination (TSD). Sox9 has been shown to be expressed in both turtle and alligator during gonadogenesis. To determine if Sox9 also has a role in a gecko species with TSD, we studied gonadal expression of Sox9 during embryonic development of the Leopard gecko (Eublepharis macularius). Gecko Sox9 was found to be highly conserved at the nucleotide level when compared to other vertebrate species including human, chick, alligator, and turtle. Sox9 was found to be expressed in embryos incubated at the male‐producing temperature (32.5°C) as well as in embryos incubated at the female‐producing temperatures (26 and 34°C), Northern blot analysis showed that Sox9 was expressed at both temperatures from morphological stages 31 to 37. mRNA in situ hybridisation on isolated urogenital systems showed expression at both female‐ and male‐producing temperatures up to stage 36. After this stage, no expression was seen in the female gonads but expression remained in the male. These data provide further evidence that Sox9 is an essential component of a testis‐determining pathway that is conserved in species with differing sex‐determining mechanisms. J. Exp. Zool. (Mol. Dev. Evol.) 291:85–91, 2001. © 2001 Wiley‐Liss, Inc.
A note on Ramsey size‐linear graphs
Authors: Balister P.N. , Schelp R.H. , Simonovits M. 
Published: August 2002

AbstractWe show that if G is a Ramsey size‐linear graph and x,y ∈ V (G) then if we add a sufficiently long path between x and y we obtain a new Ramsey size‐linear graph. As a consequence we show that if G is any graph such that every cycle in G contains at least four consecutive vertices of degree 2 then G is Ramsey size‐linear. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 1–5, 2002
On Vertices of outdegree n in minimally n‐connected digraphs
Authors: Mader W. 
Published: August 2002

AbstractLet |D| and |D|+n denote the number of vertices of D and the number of vertices of outdegree n in the digraph D, respectively. It is proved that every minimally n‐connected, finite digraph D has |D|+n ≥ n + 1 and that for n ≥ 2, there is a cn > 0 such that $|D|^+_n > C_n \sqrt{|D|}$ for all minimally n‐connected, finite digraphs D. Furthermore, case n = 2 of the following conjecture is settled which says that every minimally n‐connected, finite digraph has a vertex of indegree and outdegree equal to n. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 129–144, 2002
Path factors in cubic graphs
Authors: Kawarabayashi Ken‐ichi , Matsuda Haruhide , Oda Yoshiaki , Ota Katsuhiro 
Published: August 2002

AbstractLet ℱ be a set of connected graphs. An ℱ‐factor of a graph is its spanning subgraph such that each component is isomorphic to one of the members in ℱ. Let Pk denote the path of order k. Akiyama and Kano have conjectured that every 3‐connected cubic graph of order divisible by 3 has a {P3}‐factor. Recently, Kaneko gave a necessary and sufficient condition for a graph to have a {P3, P4, P5}‐factor. As a corollary, he proved that every cubic graph has a {P3, P4, P5}‐factor. In this paper, we prove that every 2‐connected cubic graph of order at least six has a {Pk ∣ k ≥ , 6}‐factor, and hence has a {P3, P4}‐factor. © 2002 Wiley Periodicals, Inc. J Graph Theory 39: 188–193, 2002; DOI 10.1002/jgt.10022
The senile mind: Psychology and old age in the 1930s and 1940s
Authors: Davidow Hirshbein Laura 
Published: August 2002

AbstractIn the 1930s, some psychologists began to study and discuss the normal and pathological mental abilities of old age. This paper explores this research and its implications for an emerging definition of old age in the 1930s and 1940s. The argument is that these psychologists explained old age in terms of tests they had performed on children and young adults. In addition, these professionals projected their culturally bound assumptions onto their study of old age. In the process, psychologists helped to define old age as a problem that required a professional solution. © 2002 Wiley Periodicals, Inc.
Globalization and restructuring in the South African automotive industry
Authors: Black Anthony 
Published: August 2002

AbstractThe South African automotive industry has been subjected to rapid structural change as a result of policies, which have liberalized imports but also encouraged exports. The sector has become much more internationally integrated with a particularly rapid increase in exports. This paper assesses these developments. It is argued that the costs of liberalization have been fairly low partly because of the strong encouragement given by the programme for major foreign firms to draw South African operations into their international networks. In spite of the successes, structural problems remain such as the limited rationalization that has so far taken place. Also there are question marks over the nature and sustainability of export expansion. Copyright © 2001 John Wiley & Sons, Ltd.
A small‐scale synthesis and enantiomeric resolution of (RS)‐[1‐14C]‐2‐Phenylpropionic acid and biosynthesis of its diastereomeric acyl glucuronides
Authors: Shackleford David M. , Hayball Peter J. , Reynolds Geoffrey D. , Hamon David P.G. , Evans Allan M. , Milne Robert W. , Nation Roger L. 
Published: August 2002

AbstractThe 3 step synthesis for (RS)‐[1‐14C]‐2‐phenylpropionic acid having overall yield of 30% is reported. The enantiomers were separated to an optical purity of 95 % (90 % ee) by semi‐preparative chiral HPLC using an α1‐acid glycoprotein‐based column (which has not previously been reported for this separation). Subsequently, the diastereomeric acyl glucuronides of (R)‐ and (S)‐[1‐14C]‐2‐phenylpropionic acid were biosynthesised using a recirculating‐mode isolated perfused rat liver preparation. The procedure for purification of the glucuronides by semi‐preparative HPLC was optimised to ensure the biosynthetic products did not undergo degradation via acyl migration or hydrolysis. Copyright © 2001 John Wiley & Sons, Ltd.
Syntheses of the phosphodiesterase‐4 inhibitors [11C]Ro 20‐1724, R‐, R/S‐ and S‐[11C]rolipram
Authors: DaSilva Jean N. , Lourenco Celia M. , Wilson Alan A. , Houle Sylvain 
Published: August 2002

AbstractThe high affinity and selective cAMP‐specific phosphodiesterase‐4 inhibitors Ro 20‐1724, R‐, R/S‐ and S‐rolipram were labeled with 11C by O‐[11C]methylation of their respective phenolic precursors using [11C]methyl iodide. The desmethyl precursor of Ro 20‐1724 was prepared by selective dealkylation with iodotrimethylsilane, whereas, dealkylation of racemic rolipram was not selective and yielded several products. Enantiomeric separation of R‐ and S‐desmethylrolipram was carried out by chiral semi‐preparative high performance liquid chromatography. The final 11C‐labeled products were prepared in high radiochemical purity (>99%), yields (45‐75%, decay‐corrected) and specific activities [18.5‐92.5 GBq/µmol], within 30 min from end‐of‐bombardment. Copyright © 2001 John Wiley & Sons, Ltd.
A convenient synthesis of [2,6‐14C]‐2‐chloroisonicotinic acid
Authors: Kelly Terence P. , Rodgers Thomas R. , Wright Christopher 
Published: August 2002

Abstract[2,6‐14C]‐2‐chloroisonicotinic acid (1) was prepared by kinetically controlled lithiation and carbonation of [2,6‐14C]‐2,6‐dichloropyridine, followed by reduction using hydrazine and potassium hydroxide. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and characterisation of 13C and 15N isotopomers of a 1‐acyl‐7‐nitroindoline
Authors: Corrie John E. T. , Barth Andreas , Papageorgiou George 
Published: August 2002

AbstractEfficient methods are described for synthesis of isotopomers of the water‐soluble, photolabile 1‐acyl‐7‐nitroindoline 5 with either 13C in the carbonyl of the acyl substituent or 15N in the nitro group. The isotopic incorporations were verified by IR difference spectroscopy coupled with flash photolysis.
Synthesis of 3H‐(–)‐galanthamine
Authors: Linnemann Elmar , Fels Gregor 
Published: August 2002

Abstract3‐(–)‐galanthamine (0.881 TBq/mmol) was synthesized via stereoselective reduction of (–)‐narwedine with tritiated L‐Selectride®. This reaction sequence was favored over an exchange of aromatic bromine with lithium aluminium tritide. Copyright © 2001 John Wiley & Sons Ltd.
The sequential syntheses of [76Br]FBAU 3′,5′‐dibenzoate and [76Br]FBAU
Authors: Kao Chih‐Hao K. , Sassaman Mark B. , Szajek Lawrence P. , Ma Ying , Waki Atsuo , Eckelman William C. 
Published: August 2002

AbstractThymidine analogs labeled with positron emitting radionuclides are potential proliferation markers for positron emission tomography (PET). Bromine‐76 (T1/2=16.2 h) is our choice of radionuclide, because it allows for maximal DNA incorporation of the tracer. Following the literature descriptions, 76Br was produced using the 75As (3He, 2n) 76Br reaction. We then recovered 76Br from the target in the form of [76Br]NH4Br with a yield of 60±12% (n=32). Peracetic acid was used as the oxidant for electrophilic bromodestannylation to prepare [76Br]FBAU 3′,5′‐dibenzoate (71.2±12.1%, RCY) and a basic hydrolysis of the dibenzoate then yielded [76Br]FBAU. The yield of the hydrolysis reaction was 53.1±9.2% when heated at 100°C for 15 min or quantitative (decay corrected) when left at room temperature overnight. The sequential synthesis of [76Br]FBAU 3′,5′‐dibenzoate and [76Br]FBAU allowed us to perform a side‐by‐side comparison of their metabolic stabilities. While [76Br]FBAU 3′,5′‐dibenzoate was hydrolyzed to [76Br]FBAU within 10 minutes by hepatocyte at 37°C, [76Br]FBAU was stable and no [76Br]Br− was released from either radiopharmaceutical. Both compounds are potential proliferation markers for PET. Copyright © 2001 John Wiley & Sons, Ltd.