bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure of the posthepatic septum and its influence on visceral topology in the tegu lizard, Tupinambis merianae (Teiidae: Reptilia)
Authors: Klein Wilfried , Abe Augusto S. , Andrade Denis V. , Perry Steven F.
Published: September 2003

The posthepatic septum (PHS) divides the body cavity of Tupinambis merianae into two parts: the cranial one containing the lungs and liver and the caudal one containing the remaining viscera. The PHS is composed of layers of collagenous fibers and bundles of smooth muscle, neither of which show systematic orientation, as well as isolated blood vessels, lymphatic vessels, and nerves. Striated muscle of the abdominal wall does not invade the PHS. The contractions of the smooth muscles may stabilize the pleurohepatic cavity under conditions of elevated aerobic needs rather than supporting breathing on a breath‐by‐breath basis. Surgical removal of the PHS changes the anatomical arrangement of the viscera significantly, with stomach and intestine invading the former pleurohepatic cavity and reducing the space for the lungs. Thus, the PHS is essential to maintain the visceral topography in Tupinambis. J. Morphol. 258:151–157, 2003. © 2003 Wiley‐Liss, Inc.
Morphogenesis of extraembryonic membranes and placentation in Mabuya mabouya (Squamata, Scincidae)
Authors: Jerez Adriana , Ramírez‐Pinilla Martha Patricia
Published: September 2003

Topological and histological analyses of Mabuya mabouya embryos at different developmental stages showed an extraembryonic membrane sequence as follows: a bilaminar omphalopleure and progressive mesodermal expansion around the whole yolk sac at gastrula stages; mesodermal split and formation of an exocoelom in the entire embryonic chamber at neurula stages; beginning of the expansion of the allantois into the exocoelom to form a chorioallantoic membrane at pharyngula stages; complete extension of the allantois into the exocoelom between limb‐bud to preparturition stages. Thus, a placental sequence could be enumerated: bilaminar yolk sac placenta; chorioplacenta; allantoplacenta. All placentas are highly specialized for nutrient absorption from early developmental stages. The bistratified extraembryonic ectoderm possesses an external layer with cuboidal cells and a microvillar surface around the whole yolk sac, which absorbs uterine secretions during development of the bilaminar yolk sac placenta and chorioplacenta. During gastrulation, with mesodermal expansion a dorsal absorptive plaque forms above the embryo and several smaller absorptive plaques develop antimesometrially. Both structures are similar histologically and are active in histotrophic transfer from gastrula stages until the end of development. The dorsal absorptive plaque will constitute the placentome and paraplacentome during allantoplacental development. At late gastrula–early neurula stages some absorptive plaques form chorionic concavities or chorionic bags that are penetrated by a long uterine fold and seem to have a specialized histotrophic and/or metabolic role. The extraembryonic mesoderm does not ingress into the yolk sac and neither an isolated yolk mass nor a yolk cleft are formed. This derived pattern of development may be related to the drastic reduction of the egg size and obligatory placentotrophy from early developmental stages. Our results show new specialized placentotrophic structures and a novel arrangement of extraembryonic membrane morphogenesis for Squamata. J. Morphol. 258:158–178, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructure of the mature spermatozoa of caecilians (Amphibia: Gymnophiona)
Authors: Scheltinga David M. , Wilkinson Mark , Jamieson Barrie G.M. , Oommen Oommen V.
Published: September 2003

The spermatozoa of Gymnophiona show the following autapomorphies: 1) penetration of the distal centriole by the axial fiber; 2) presence of an acrosomal baseplate; 3) presence of an acrosome seat (flattened apical end of nucleus); and 4) absence of juxta‐axonemal fibers. The wide separation of the plasma membrane bounding the undulating membrane is here also considered to be apomorphic. Three plesiomorphic spermatozoal characters are recognized that are not seen in other Amphibia but occur in basal amniotes: 1) presence of mitochondria with a delicate array of concentric cristae (concentric cristae of salamander spermatozoa differ in lacking the delicate array); 2) presence of peripheral dense fibers associated with the triplets of the distal centriole; and 3) presence of a simple annulus (a highly modified, elongate annulus is present in salamander sperm). The presence of an endonuclear canal containing a perforatorium is a plesiomorphic feature of caecilian spermatozoa that is shared with urodeles, some basal anurans, sarcopterygian fish, and some amniotes. Spermatozoal synapomorphies are identified for 1) the Uraeotyphlidae and Ichthyophiidae, and 2) the Caeciliidae and Typhlonectidae, suggesting that the members of each pair of families are more closely related to each other than to other caecilians. Although caecilian spermatozoa exhibit the clear amphibian synapomorphy of the unilateral location of the undulating membrane and its axial fiber, they have no apomorphic characters that suggest a closer relationship to either the Urodela or Anura. J. Morphol. 258:179–192, 2003. © 2003 Wiley‐Liss, Inc.
Diversification of brain and sense organ morphology in antarctic dragonfishes (Perciformes: Notothenioidei: Bathydraconidae)
Authors: Eastman Joseph T. , Lannoo Michael J.
Published: September 2003

In the subzero shelf waters of Antarctica, fishes of the perciform suborder Notothenioidei dominate the fish fauna and constitute an adaptive radiation and a species flock. The 16 species of dragonfishes of the family Bathydraconidae live from surface waters to nearly 3,000 m and have the greatest overall depth range among notothenioid families. We examined the anatomy and histology of the brain, retina, and cephalic lateral line system of nine bathydraconid species representing 8 of the 11 known genera. We evaluate these data against a cladogram identifying three clades in the family. We provide a detailed drawing of the brain and cranial nerves of Gymnodraco acuticeps and Akarotaxis nudiceps. Bathydraconid brain morphology falls into two categories. Brains of most species are similar to those of generalized perciforms and some basal notothenioids (Class I). However, brains of deep‐living bathydraconids (members of the tribe Bathydraconini minus Prionodraco) have a reduced telencephalon and tectum that renders the neural axis visible — the stalked brain morphology (Class II). All bathydraconids have duplex (rod and cone) retinae but there is considerable interspecific variation in the ratio of cones:rods and in the number of cells in the internal nuclear layer. Retinal histology reflects habitat depth but is not tightly coupled to phylogeny. Although the deep‐living species of Bathydraconini have rod‐dominated retinae, the retinae of some sister species are photopic. An expanded cephalic lateral line system is also characteristic of all members of the Bathydraconini as exemplified by Akarotaxis. This morphology includes large lateral line pores, wide membranous canals, hypertrophied canal neuromasts, and large anterodorsal lateral line nerves, eminentia granulares, and crista cerebellares. The saccular otoliths are also enlarged in members of this tribe. Neural diversification among bathydraconids on the Antarctic shelf has not involved the evolution of sensory specialists. Brain and sense organ morphologies do not approach the specialized condition seen in primary deep‐sea fishes or even that of some secondary deep‐sea fishes including sympatric non‐notothenioids such as liparids (snailfishes) and muraenolepidids (eel cods). The brains and sense organs of bathydraconids, including the deep‐living species, reflect their heritage as perciform shorefishes. J. Morphol. 258:130–150, 2003. © 2003 Wiley‐Liss, Inc.
Fetal development of the segment‐specific papillary body in the equine hoof
Authors: Bragulla Hermann
Published: September 2003

Fetal development of the unique papillary body and its localized peculiarities in the equine hoof are described based on the study of 51 fetuses, nine newborn foals, and five adult horses. The shape and dimensions of the dermal papillae and lamellae have a formative influence on the structure and physical quality of the corneous hoof capsule with its horn tubules and lamellae. The size and arrangement of these horn structures determine the mechanical quality of hoof horn. Proper horn quality is a prerequisite for the various functions of the hoof capsule, such as protecting the living dermis supporting the hoof capsule, shock absorption, and formation of the suspensory apparatus of the distal phalanx. Development of the segment‐specific papillary body is initiated by the increasing mitotic activity of the epidermal cells invaginating the dermal surface, thus forming dermal microridges. These microridges are transformed into single dermal papillae, which are arranged in rows, or enlarged to become primary and secondary dermal lamellae. The formation of a segment‐specific papillary body enables the increasing keratinization ratio in the hoof epidermis and the formation of the characteristic tubular and lamellar horn responsible for the special mechanical properties of hoof horn. J. Morphol. 258:207‐224, 2003. © 2003 Wiley‐Liss, Inc.
The term “lateral recess” and craniofacial pneumatization in old world monkeys (Mammalia, Primates, Cercopithecoidea)
Authors: Rae Todd C. , Koppe Thomas
Published: September 2003

The primate superfamily Cercopithecoidea (or Old World monkeys) is characterized by a widespread lack of the maxillary sinus, a paranasal pneumatic space found in most other eutherian mammals. Previous discussions of the distribution of pneumatization in the group, however, have been ambiguous and contradictory, and have been further complicated by discussion of a poorly defined structure named the “lateral recess,” linked implicitly to the maxillary sinus. Computed tomography (CT) was applied to dry crania of all cercopithecoid genera to evaluate the morphological relevance of the term “lateral recess.” Results suggest that the “lateral recess” is a structural consequence of changes in skull form unrelated to pneumatization. Thus, the term should be abandoned. All Old World monkeys (except the genus Macaca) are found to lack the maxillary sinus, but a previously undescribed bulla, only separated from the nasal cavity anteriorly, was discovered in the Chinese golden monkey Rhinopithecus. If this bulla is related to the paranasal sinuses, it suggests that the initial change in cercopithecoid cranial evolution was a suppression of pneumatic development, which may have been subsequently reversed twice in the history of the group, in Macaca and Rhinopithecus. J. Morphol. 258:193–199, 2003. © 2003 Wiley‐Liss, Inc.
Alimentary tract of kowalevskiidae (appendicularia, tunicata) and evolutionary implications
Authors: Brena Carlo , Cima Francesca , Burighel Paolo
Published: September 2003

The alimentary tract of Kowalevskia tenuis and K. oceanica, the only species of the appendicularian family Kowalevskiidae, was studied both at the light and electron microscope levels and compared with species belonging to the other two families of the class. Kowalevskids show interesting specializations: 1) the pharynx opens on both sides through two opposing spiracles, modified into long ciliated fissures, and possesses an original filtering system of ciliated combs arranged in two pairs of opposing longitudinal rows; 2) the endostyle is absent, its place being taken by a ciliated groove without any glandular cell; 3) posterior to the esophagus, the globular stomach and rectum form a digestive nucleus comprising a few, large cells including two well‐developed, specialized valves, cardiac and pyloric; 4) special apical junctions bearing characteristics of both gap and adherens junctions are diffuse along the gut epithelium; 5) the heart is absent. Our data suggest that Kowalevskiidae underwent a high degree of specialization for food filtering and are more closely related to Fritillariidae, with which they share several characters, rather than Oikopleuridae, the latter probably representing the most primitive family of appendicularians. J. Morphol. 258:225–238, 2003. ©2003 Wiley‐Liss, Inc.
Patterns of ossification in the manus of the harbor porpoise (Phocoena phocoena): Hyperphalangy and delta‐shaped bones
Authors: Dawson Susan D.
Published: September 2003

With the transition from terrestrial to aquatic habitats, cetacean forelimbs have undergone significant modifications in bone morphology and soft tissue distribution. Some, but not all, of these modifications are also demonstrated in other lineages of extant and extinct secondarily aquatic tetrapods. This study examines the ontogenetic pattern of ossification of the manus of the harbor porpoise (Phocoena phocoena), using plain film radiography. Two modifications examined are hyperphalangy (number of phalanges per digit increased beyond the typical mammalian number) and the morphology of delta‐shaped bones. Hyperphalangy in Phocoena phocoena is apparent in digits 2 and 3. Phalangeal counts in all digits are variable (sometimes between the right and left flippers of the same individual) and are not necessarily correlated with age. Phalangeal ossification and epiphyseal fusion proceeds along the proximo–distal axis within each digit. In addition, digits 2 and 3 are at a more advanced stage of ossification than more abaxial digits. Delta‐shaped bones appear to be a normal stage in the ossification of phalanges in all digits except the third, and may persist in the adult in certain digits. In humans, this morphology is a developmental anomaly usually associated with other malformations, such as polydactyly or syndactyly. Delta‐shaped bones in the cetacean manus display a consistent orientation and the process by which they are formed may be similar to that in extinct marine reptiles. J. Morphol. 258:200–206, 2003. © 2003 Wiley‐Liss, Inc.
Scale microornamentation of uropeltid snakes
Authors: Gower David J.
Published: September 2003

Microornamentation was examined on the exposed oberhautchen surface of dorsal, lateral, and ventral scales from the midbody region of 20 species of the fossorial snake family Uropeltidae and seven species of fossorial scolecophidian and anilioid outgroups. No substantial variation was observed in microornamentation from the different areas around the midbody circumference within species. All oberhautchen cells were flat and exhibited no major surface features other than occasional posterior margin denticulations, small pores/pits, and narrow, low ridges. This is largely consistent with the hypothesis that friction reduction and dirt shedding are the main selective pressures on microornamentation, given that reducing shine is not of key importance in fossorial animals. Variations among taxa were observed in the shape and size of oberhautchen cells, in the presence of pores/pits, in the presence and size of denticulations on posterior cell margins, and in the level or imbricate nature of cell borders. Six microornamentation characters were formulated, scored, and plotted onto a selected phylogeny. Character evolution and phylogenetic signal were explored, accepting the incomplete understanding of intraspecific variation and of uropeltid interrelationships. There is evidence that all but one of these characters evolved homoplastically, probably by multiple independent origin. There is no clear evidence for character state reversal, but greater phylogenetic resolution is required to test this further. Phylogenetic signal appears to exist in some instances, including possible microornamentation synapomorphies for Uropeltidae and Melanophidium. These derived character states are found elsewhere within Squamata. A microornamentation of narrow, finely, and regularly spaced ridges is associated with scale iridescence. These ridges, and possibly pores/pits, are also associated with scales that are less wettable, and that therefore might be expected to be better at shedding dirt in moist conditions. Testable hypotheses are presented that might explain minor variations in the form of ridges and pits among uropeltids. J. Morphol. 258:249–268, 2003. © 2003 Wiley‐Liss, Inc.
Morphology of the midgut trunk in the penaeid shrimp, Sicyonia ingentis, highlighting novel nuclear pore particles and fixed hemocytes
Authors: Martin Gary G. , Chiu Alice
Published: September 2003

The morphology of the midgut trunk (MGT) in the penaeid shrimp Sicyonia ingentis was examined by light and scanning and transmission electron microscopy. Although the function of the MGT is poorly understood, it is not involved with the digestion and absorption of nutrients, and it appears to be the surface of a shrimp least protected from penetration by potential pathogens. As described for other decapod crustaceans, the MGT in shrimp is composed of a simple columnar epithelium separated from a layer of connective tissue by a thick basal lamina. Beneath the basal lamina is a previously unreported layer of hemocytes, exclusively of the granulocyte variety, embedded in a matrix continuous with the basal lamina and extending into the connective tissue. This layer was observed in four other species of penaeid shrimp. Granulocytes in circulation can phagocytose and encapsulate foreign material and the granules contain antibacterial molecules, lysosomal enzymes, and prophenoloxidase. We suggest that the granulocytes associated with the basal lamina have matured at this site and are well positioned to fight potential pathogens that have penetrated the epithelial layer of the MGT. A second observation is the presence of clusters of cylinders bound to the nuclear pores of the epithelial cells. The possibility that these clusters are viruses, organelles, or abnormal organelles induced by disease or toxic materials is discussed. These unique particles were observed in S. ingentis but none of the other penaeid shrimp we examined. J. Morphol. 258:239–248, 2003. © 2003 Wiley‐Liss, Inc.
Role of manganese(II), micelles, and inorganic salts on the kinetics of the redox reaction of L‐sorbose and chromium(VI)
Authors: Kabir‐Ud‐Din  , Morshed Abu Mohammad Azmal , Khan Zaheer
Published: September 2003

The kinetics of the reduction of chromium(VI) to chromium(III) by L‐sorbose in HClO4 was studied between 30 and 80°C at various concentrations of reactants and acidities in both aqueous and micellar sodium dodecyl sulfate (SDS)/TritonX‐100(TX‐100) solutions. Under pseudo‐first‐order conditions the reaction rate is fractional‐order in [L‐sorbose] and [H+], and first‐order in [CrVI] both in the absence and in the presence of surfactant micelles. The reaction is accelerated by addition of manganese(II) and is routed through the same mechanism as shown by the kinetic studies in the absence and presence of surfactants. The rate enhancement in presence of SDS/TX‐100 micelles indicates that essentially all the reactive species are bound to micelles under the experimental conditions. The observed catalyses are explained with the modified Menger and Portnoy model. Inorganic salts (NaBr, LiBr, NH4Br) inhibit the reaction in presence of SDS micelles, which confirms exclusion of the reactive species of chromium(VI) from the reaction site. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 543–554, 2003
Kinetics and mechanisms of transalkylation and disproportionation of meta‐diethylbenzene by triflic acid catalyst
Authors: Al‐Zahrani S. M. , Al‐Kinany M. C. , Al‐Humaizi K. I. , Al‐Khowaiter S. H.
Published: September 2003

The kinetics of transalkylation and isomerization of meta‐diethylbenzene in the presence of benzene using triflic acid as a catalyst has been investigated. High catalytic activity of the triflic acid catalyst was observed in homogeneous liquid‐phase reactions. On the basis of the product distribution obtained, transalkylation, disproportionation, and isomerization reactions have been considered and the main product of the reaction was ethylbenzene. These reactions are conducted in a closed liquid batch reactor with continuous stirring under dry nitrogen and atmospheric pressure over the temperature range of 288–308 K. The main transalkylation, disproportionation, and isomerization reactions occurred simultaneously and were considered as elementary reactions. The apparent activation energy of the transalkylation reaction was found to be 35.5 kJ/mol, while that of disproportionation reaction was 42.3 kJ/mol. The reproducibility of the experimental product distribution occurred with an average relative error of ±2%. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 555–563, 2003
Kinetics of amino acid racemization (epimerization) in the dentine of fossil and modern bear teeth
Authors: Canoira Laureano , García‐Martínez Maria‐Jesús , Llamas Juan F. , Ortíz José E. , Torres Trinidad De
Published: September 2003

The present study examines the question of whether heating experiments on modern bear teeth dentine model the pattern of D/L racemization in fossil teeth. Using samples of modern bear teeth dentine heated at 65°C, 85°C (up to 53 days), and 105°C (up to 71 days), and three independently dated fossil bear teeth, we have compared the modes of racemization induced by temperature in the modern samples and by time on the fossil samples. We have studied seven amino acids (aspartic and glutamic acids, alanine, valine, leucine, isoleucine, and phenylalanine) that follow a reversible first‐order kinetic model of racemization (epimerization) either at low or high temperature. We have estimated the Arrhenius parameters, the activation energy Ea and the frequency factor A, first based on the heating experiments, and later including the fossil data. Valine shows no appreciable differences in Ea and A in both estimations, and could then be used with confidence in dating studies. In a lesser extension this also applies to alanine, phenylalanine, leucine, and glutamic acid. Aspartic acid shows a great difference between the temperature‐induced and the time‐induced racemization kinetic models, and it should be used with special care in dating studies, since diagenetic racemization in aspartic acid is extremely sensitive to the thermal history of the site. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 576–591, 2003
Experimental and kinetic modeling study of the effect of NO and SO2 on the oxidation of COH2 mixtures
Authors: Dagaut Philippe , Lecomte Franck , Mieritz Jacob , Glarborg Peter
Published: September 2003

The effect of NO and SO2 on the oxidation of a COH2 mixture was studied in a jet‐stirred reactor at atmospheric pressure and for various equivalence ratios (0.1, 1, and 2) and initial concentrations of NO and SO2 (0–5000 ppm). The experiments were performed at fixed residence time and variable temperature ranging from 800 to 1400 K. Additional experiments were conducted in a laminar flow reactor on the effect of SO2 on COH2 oxidation in the same temperature range for stoichiometric and reducing conditions. It was demonstrated that in fuel‐lean conditions, the addition of NO increases the oxidation of the COH2 mixture below 1000 K and has no significant effect at higher temperatures, whereas the addition of SO2 has a small inhibiting effect. Under stoichiometric and fuel‐rich conditions, both NO and SO2 inhibit the oxidation of the COH2 mixture. The results show that a COH2 mixture has a limited NO reduction potential in the investigated temperature range and rule out a significant conversion of HNO to NH through reactions like HNO + CO ⇔︁ NH + CO2 or HNO + H2 ⇔︁ NH + H2O. The chain terminating effect of SO2 under stoichiometric and reducing conditions was found to be much more pronounced than previously reported under flow reactor conditions and the present results support a high rate constant for the H + SO2 + M ⇔︁ HOSO + M reaction. The reactor experiments were used to validate a comprehensive kinetic reaction mechanism also used to simulate the reduction of NO by natural gas blends and pure C1 to C4 hydrocarbons. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 564–575, 2003
Salt effects on the reactivity of the base‐catalyzed hydrolysis of some novel low‐spin hydrophobic Fe(II)–amino acid azomethine chelates
Authors: Shaker Ali M. , Nassr Lobna A. E.
Published: September 2003

Salt effects on the reactivity of base hydrolysis of Fe(II) chelates [naphthylideneisoleucinate (nili), naphthylideneleucinate (nli), naphthylideneserinate (nsi), salicylideneisoleucinate (sili), salicylideneleucinate (sli), salicylidenemethioninate (smi), and salicylidenetryptophanate (sti)] have been investigated in aqueous media containing alkali metal halides and tetra‐n‐butylammonium bromide (TBAB). NaCl and NaBr exhibited different reactivity trends from those of KBr and TBAB.

The observed patterns vary markedly with complex hydrophobicity. Generally, the presence of the salt markedly enhances the rate compared to its absence. This behavior agrees with the anionic nature of the transient species. With increasing added NaCl and NaBr, the rate of the reaction decreases. The rate decreases and then increases on increasing the concentration of KBr and TBAB. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 592–601, 2003
Spectroscopy of hydrothermal reactions, part 26: Kinetics of decarboxylation of aliphatic amino acids and comparison with the rates of racemization
Authors: Li Jun , Brill Thomas B.
Published: September 2003

The kinetics of decarboxylation of six α‐amino acids (glycine, alanine, aminobutyric acid, valine, leucine, and isoleucine) and β‐aminobutyric acid were studied in aqueous solution at 310–330ˆC and 275 bar over the pH25 range 1.5–8.5 by using an in situ FT‐IR spectroscopy flow reactor. Based on the rate of formation of CO2, the first‐order or pseudo‐first‐order rate constants were obtained along with the Arrhenius parameters. The decarboxylation rates of amino acids follow the order Gly > Leu ≈ Ile ≈ Val > Ala > α‐Aib > β‐Aib. Differences in the concentration between 0.05 and 0.5 m had only a minor effect on the decarboxylation rate. The effect of the position of the amino group on the decarboxylation rate was investigated for α‐, β‐, and γ‐aminobutyric acid and the order was found to be α > β ≫ γ. Although the pH dependence is complex, the decarboxylation rates of α‐amino acids qualitatively have the inverse trend of the racemization rates. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 602–610, 2003
The vascular network of tumours — what is it not for?
Authors: Sivridis Efthimios , Giatromanolaki Alexandra , Koukourakis Michael I
Published: September 2003

It is becoming almost a dogma that tumours cannot grow beyond 1–2 mm3unless they are supported by a rich vascular supply1. It is true that tumours promote angiogenesis and that highly vascularized carcinomas have, in general, a more aggressive clinical course than carcinomas of low vascularization2,3. However, a study of intratumoral angiogenesis reveals that the newly formed vessels are commonly deprived of those structural qualities that would allow them to perform an optimal oxygenation function3. Thus, most tumours, irrespective of their angiogenic status, behave as if they were ‘hypoxic’, urging (via angiogenic mediators) for, what would look paradoxical at first sight, more defective angiogenesis. It is hypothesized that tumour cells can grow into solid neoplasms by exploiting the host's pre‐existing vessels, without the need for new blood vessel formation. Neovascularization, however, may be important for tumours with an exophytic pattern of growth as these, by their very nature, lose the host's sheltering stroma. Shifting to anaerobic glycolysis and activation of anti‐apoptotic pathways are complementary mechanisms for tumour cell survival and growth. Besides, continuous and indiscriminate production of a defective vascular network ensures an increased metastatic potential since the newly formed intratumoral vessels, simulating venular‐like spaces, are easily permeable to tumour cells, facilitating metastases. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of novel proteins associated with hepatocellular carcinomas using protein microarrays
Authors: Tannapfel Andrea , Anhalt Kathrin , Häusermann Philip , Sommerer Florian , Benicke Markus , Uhlmann Dirk , Witzigmann Helmut , Hauss Johann , Wittekind Christian
Published: September 2003

Characterization of the protein profiles expressed by hepatocellular carcinomas (HCCs) may identify the genes involved in hepatocellular carcinogenesis and offers the possibility of elucidating clinical biomarkers. In an effort to discover such proteins and pathways that are deregulated in hepatocellular carcinogenesis, cellular proteomes of matched normal liver cells and carcinoma were analysed by tissue microdissection and protein microarrays. Using protein microarrays made up of 83 different antibodies, it was possible to monitor alterations of the protein levels in HCC and non‐neoplastic liver tissue. Further analysis of altered proteins was performed using western blot analysis and tissue microarrays (TMAs) containing 210 HCC specimens and corresponding liver tissue. The protein microarray approach revealed differential expression between HCC and normal liver of 32 of the 83 proteins examined: 21 of these were up‐regulated and 11 down‐regulated. IGF (insulin growth factor) II, ADAM (a disintegrin and metalloproteases) 9, STAT (signal transducers and activators of transcription) 3, SOCS (suppressors of cytokine signalling) 3, and cyclin D1 were significantly up‐regulated and collagen I, SMAD 4, FHIT (fragile histidine triad), and SOCS1 were down‐regulated. The differential expression of these proteins was confirmed using western blot analysis and TMAs. Correlation of differentially regulated proteins with clinico‐pathological data showed that cyclin D1 and SOCS1 were associated with tumour prognosis in univariate analysis, but not multivariate analysis. These data indicate that the development of an array‐based approach for the determination of protein profiles in HCC may facilitate the identification of new proteins associated with carcinogenesis or prognosis. Copyright © 2003 John Wiley & Sons, Ltd.
The effect of gender on Helicobacter felis‐mediated gastritis, epithelial cell proliferation, and apoptosis in the mouse model
Authors: Court M , Robinson PA , Dixon MF , Jeremy AHT , Crabtree JE
Published: September 2003

The murine Helicobacter felis model has been extensively used to investigate the importance of host factors in the development of chronic gastritis. The effect of gender in this murine model is unknown. Male and female C57BL/6J mice were infected with H felis for up to 1 year. At 4, 8, 19, 36, and 52 weeks post‐infection, gastric histopathology, epithelial cell proliferation, and apoptosis were examined and compared with age‐ and gender‐matched controls. In female mice, infection with H felis resulted in an earlier onset of chronic gastric inflammation, epithelial hyperplasia, and oxyntic cell loss than males. In females, there was a trend towards increased gastric pathology compared with males, with long‐term‐infected female mice having significantly greater (p < 0.05) chronic inflammation than male mice. The histopathological differences in male and female mice did not relate to the density of H felis infection. Female mice infected with H felis had significantly increased gastric epithelial cell proliferation in the cardia and corpus at both 8 and 52 weeks post‐infection (p < 0.05). Epithelial cell apoptosis in the glandular mucosa of the corpus at 36 and 52 weeks post‐infection was significantly increased (p < 0.05) in female mice compared with uninfected gender controls. In contrast, there was no significant increase in epithelial cell proliferation or apoptosis in any area of the stomach at any time point after H felis infection in male mice. These results demonstrate that there are gender differences in the gastric inflammatory and epithelial response to H felis in the murine model. The functional importance of gender should be considered in future murine studies on H felis‐ and H pylori‐induced chronic gastritis. Copyright © 2003 John Wiley & Sons, Ltd.
Expression of AP‐2α, c‐kit, and cleaved caspase‐6 and ‐3 in naevi and malignant melanomas of the skin. A possible role for caspases in melanoma progression?
Authors: Woenckhaus Christian , Giebel Jürgen , Failing Klaus , Fenic Irina , Dittberner Thomas , Poetsch Micaela
Published: September 2003

Progression of melanoma is associated with loss of the transcription factor AP‐2α and tyrosine‐kinase receptor c‐kit. However, the mechanisms by which these two proteins are down‐regulated have not been fully elucidated. Fifty non‐selected melanomas comprising ten superficial spreading melanomas (five exhibiting a radial growth phase and five a vertical growth phase), ten primary nodular melanomas, 30 melanoma metastases, and 16 naevi were investigated by direct sequencing analysis of the AP‐2α and c‐kit genes and by immunohistochemistry for the respective proteins. Because it has recently been demonstrated that AP‐2α is preferentially cleaved by caspase‐6 and to a lesser extent by caspase‐3, immunohistochemistry for the cleaved (activated) forms of caspase‐6 (c‐casp‐6) and caspase‐3 (c‐casp‐3) was carried out. No mutations were identified in the c‐kit gene, but three different point mutations were demonstrated in the activation motif of AP‐2α in four tumours: one vertical growth phase superficial spreading melanoma, one nodular melanoma, and two metastases. Immunohistochemistry revealed progressive loss of the AP‐2α and c‐kit proteins in primary melanomas and metastases when compared with naevi. The decrease of both markers was more accentuated in the dermal component of all primary tumours, with c‐kit more affected than AP‐2α. All invasive melanomas and metastases expressed c‐casp‐6. c‐casp‐3 was expressed by 83% of the metastases and in the dermal component of one nodular melanoma. These findings suggest that the loss of AP‐2α protein expression during the progression of melanoma could be related to mutation of the gene in only a small number of tumours, whereas the expression and activation of caspases, most prominently caspase‐6, may be an important factor for the down‐regulation of AP‐2α protein. Furthermore, this study supports recent data that the activation of caspases does not inevitably result in apoptosis, but may also contribute to tumour progression in melanomas. Copyright © 2003 John Wiley & Sons, Ltd.
CD40 ligand is selectively expressed on CD4+ T cells and platelets: implications for CD40–CD40L signalling in atherosclerosis
Authors: Büchner Kerstin , Henn Volker , Gräfe Michael , de Boer Onno J , Becker Anton E , Kroczek Richard A
Published: September 2003

Atherosclerosis is a degenerative inflammatory disease of the vascular system. Endothelial cells (ECs), smooth muscle cells, and macrophages, key elements in atherosclerosis, all have the potential to express the CD40 receptor and are thus susceptible to potent pro‐inflammatory signals by CD40 ligand (CD40L)‐bearing cells. CD40L is a TNF‐α‐related membrane protein originally identified on activated T cells. The recent recognition of platelets as an abundant source of CD40L led to a reassessment of the involvement of CD40L in atherosclerosis. In the present report, CD40L+ T cells were identified in the intima of atherosclerotic tissues within macrophage infiltrates and in areas of neovascularization. These CD40L+ T cells were CD4+, CD69+, but negative for CD8, CD25, CD28, and ICOS. In some specimens, CD40L+ platelets were identified in the intima and in plaque ruptures. Contrary to previous reports, CD40L was not observed on ECs, smooth muscle cells, and macrophages in atherosclerotic tissues or in vitro at the protein and mRNA levels. Functionally, flow chamber experiments demonstrated that stimulation of ECs via CD40 is sufficient to recruit neutrophils and T cells from whole blood to ECs and suggested that CD40L+ platelets contribute significantly to the recruitment of inflammatory cells to damaged endothelium in vivo. However, due to the short half‐life of platelet CD40L, the chronic CD40L‐driven inflammatory component can only be sustained by activated CD4+ T cells. Contrary to current understanding, the contribution of CD40L to chronic inflammation in atherosclerosis is thus antigen‐driven and MHC‐dependent. This conclusion has significant therapeutic implications. Copyright © 2003 John Wiley & Sons, Ltd.
Frequent loss of Fas expression and function in human lung tumours with overexpression of FasL in small cell lung carcinoma
Authors: Viard‐Leveugle Isabelle , Veyrenc Sylvie , French Lars E , Brambilla Christian , Brambilla Elisabeth
Published: September 2003

Fas (CD95) and its ligand FasL signal apoptosis and are involved in tissue homeostasis and the elimination of target cells by cytotoxic T cells. Corruption of this signalling pathway in tumour cells, for example by reduced Fas expression or increased FasL expression, can participate in tumour development and immune escape. The present study has analysed Fas/FasL expression and Fas death signalling function in vivo in lung tumour tissues [57 non‐small cell lung carcinomas and 64 neuroendocrine lung tumours including small cell lung carcinoma (SCLC)] in comparison with normal lung tissue, and in vitro in neuroendocrine tumour cell lines in comparison with normal human bronchial epithelial cells. The Fas expression score was markedly decreased compared with normal lung tissue in 90% of the 121 lung tumours and was completely lost in 24%. The Fas staining pattern suggested cytoplasmic Fas expression in tumours, whereas membrane expression was observed in normal lung tissue. Loss of Fas at the cell surface was also shown in vitro by FACS analysis of neuroendocrine tumour cell lines and was concomitant with the resistance of tumour cells to FasL‐mediated apoptosis according to in vitro cell viability. The lack of cell surface Fas expression in tumour cell lines resulted from the lack of intracellular Fas protein due to impaired Fas gene transcription. The FasL expression score was also decreased in most non‐small cell lung carcinomas compared with normal bronchial cells, whereas 91% of SCLCs had higher expression than normal cells. FasL overexpression was related to advanced tumour stage as well as to a Fas/FasL ratio less than 1. It is concluded that a marked decrease in Fas expression may be part of lung tumourigenesis allowing tumour cells to escape from apoptosis. FasL overexpression in the context of Fas down‐regulation in SCLC predicts the ability of SCLC cells to induce paracrine killing of Fas‐expressing cytotoxic T cells. In lung tumours, Fas restoration may represent a key, although not unique, step in therapeutic strategies to reconstitute the ability of tumour cells to undergo apoptosis. Copyright © 2003 John Wiley & Sons, Ltd.
Inhibition of advanced glycation end‐products protects against retinal capillary basement membrane expansion during long‐term diabetes
Authors: Gardiner TA , Anderson HR , Stitt AW
Published: September 2003

The purpose of this study was to investigate the advanced glycation end‐product (AGE)‐inhibitory properties of aminoguanidine and to determine whether treatment in long‐term diabetic rats can prevent basement membrane lesions of diabetic retinopathy. Four groups of male Wistar rats were studied: untreated diabetics injected with 45 mg/kg streptozotocin, aminoguanidine‐treated diabetics, untreated controls, and aminoguanidine‐treated controls. After 12 months' diabetes, the retinas from six animals were processed for electron microscopy or the retinal microvasculature was isolated using the trypsin digest technique. Stereological analysis was used to estimate quantitative ultrastructural changes in the retinal capillary‐associated basement membrane. Serum AGEs were quantified by competitive AGE‐ELISA, while microvascular‐associated, immunoreactive AGEs were analysed on retinal trypsin digests. Aminoguanidine significantly reduced serum AGEs in the diabetic group (p < 0.001). In the retinal capillaries, there was a marked reduction in AGE immunoreactivity in the aminoguanidine‐treated diabetics when compared with untreated diabetics. The surface area and absolute volume of the retinal capillary basement membrane were significantly increased in the diabetic rats when compared with non‐diabetic controls (p < 0.001 and p < 0.001, respectively). Aminoguanidine treatment of diabetic rats protected against basement membrane expansion when compared with untreated diabetic counterparts. Aminoguanidine treatment prevents the development of diabetes‐induced basement membrane expansion in retinal capillaries. The AGE inhibition properties of aminoguanidine suggest that AGEs play an important role in the complex pathogenesis of basement membrane thickening during diabetic retinopathy. Copyright © 2003 John Wiley & Sons, Ltd.
Mature adipocytes, but not preadipocytes, promote the growth of breast carcinoma cells in collagen gel matrix culture through cancer–stromal cell interactions
Authors: Manabe Yasushi , Toda Shuji , Miyazaki Kohji , Sugihara Hajime
Published: September 2003

Interaction between cancer and stromal cells is critical for tumour cell growth and invasion. It has recently been suggested that mature adipocytes, a specific type of stromal cell that is abundant in the breast, affect the biological behaviour of some epithelial cell types. However, the nature of the interaction between mature adipocytes and breast cancer cells remains unclear. The present study has examined the effects of mature rat adipocytes, as the main cell type in adipose tissue, on the growth, apoptosis, and cell adhesion of breast carcinoma cell lines [human oestrogen receptor (ER)‐positive cell lines MCF‐7, ZR75‐1, and T47‐D; and the ER‐negative mouse cell line MMT 060562] by analysing bromodeoxyuridine (BrdU) uptake, apoptotic indices, and immunohistochemical expression of E‐cadherin. As a reference, the effects of rat preadipocytes (immature adipocytes) on the behaviour of the cell lines were examined. The cell lines were cultured in a three‐dimensional collagen gel matrix with mature adipocytes or preadipocytes. Mature adipocytes significantly promoted BrdU uptake by all cell lines other than MMT 060562 cells. Preadipocytes decreased the uptake of T47‐D cells and had no effect on that of MCF‐7, ZR75‐1 or MMT 060562 cells. Mature adipocytes or preadipocytes did not affect the apoptotic indices of any of the cell lines. Mature adipocytes did not influence E‐cadherin expression in any of the cell lines, but preadipocytes clearly promoted E‐cadherin expression by MCF‐7 and T47‐D cells, but not by R75‐1 and MMT 060562 cells. These data suggest that mature adipocytes may be involved in the mechanisms regulating the growth of breast cancer mass through their growth‐promoting effect on ER‐positive tumour cells. Copyright © 2003 John Wiley & Sons, Ltd.
Tight junctional abnormality in multiple sclerosis white matter affects all calibres of vessel and is associated with blood–brain barrier leakage and active demyelination
Authors: Kirk John , Plumb Jonnie , Mirakhur Meenakshi , McQuaid Stephen
Published: September 2003

Blood–brain barrier (BBB) hyperpermeability in multiple sclerosis (MS) is associated with lesion pathogenesis and has been linked to pathology in microvascular tight junctions (TJs). This study quantifies the uneven distribution of TJ pathology and its association with BBB leakage. Frozen sections from plaque and normal‐appearing white matter (NAWM) in 14 cases were studied together with white matter from six neurological and five normal controls. Using single and double immunofluorescence and confocal microscopy, the TJ‐associated protein zonula occludens‐1 (ZO‐1) was examined across lesion types and tissue categories, and in relation to fibrinogen leakage. Confocal image data sets were analysed for 2198 MS and 1062 control vessels. Significant differences in the incidence of TJ abnormalities were detected between the different lesion types in MS and between MS and control white matter. These were frequent in oil‐red O (ORO)+ active plaques, affecting 42% of vessel segments, but less frequent in ORO− inactive plaques (23%), NAWM (13%), and normal (3.7%) and neurological controls (8%). A similar pattern was found irrespective of the vessel size, supporting a causal role for diffusible inflammatory mediators. In both NAWM and inactive lesions, dual labelling showed that vessels with the most TJ abnormality also showed most fibrinogen leakage. This was even more pronounced in active lesions, where 41% of vessels in the highest grade for TJ alteration showed severe leakage. It is concluded that disruption of TJs in MS, affecting both paracellular and transcellular paths, contributes to BBB leakage. TJ abnormality and BBB leakage in inactive lesions suggests either failure of TJ repair or a continuing pathological process. In NAWM, it suggests either pre‐lesional change or secondary damage. Clinically inapparent TJ pathology has prognostic implications and should be considered when planning disease‐modifying therapy. Copyright © 2003 John Wiley & Sons, Ltd.
Reduced expression of oestrogen receptor β in invasive breast cancer and its re‐expression using DNA methyl transferase inhibitors in a cell line model
Authors: Skliris George P , Munot Kailas , Bell Sandra M , Carder Pauline J , Lane Sally , Horgan Kieran , Lansdown Mark RJ , Parkes Alicia T , Hanby Andrew M , Markham Alexander F , Speirs Valerie
Published: September 2003

To gain insights into the possible role of oestrogen receptor (ER) β in breast carcinogenesis, immunohistochemical analysis of ER β was performed on 512 breast specimens encompassing normal (n = 138), pure ductal carcinoma in situ (n = 16), invasive cancers (n = 319), lymph node metastases (n = 31), and recurrences (n = 8). Real‐time polymerase chain reaction (PCR) was used to investigate the methylation status of the ER β gene in the ER β negative breast cancer cell lines SkBr3 and MDA‐MB‐435. A gradual reduction in, but not a complete loss of, ER β expression was observed during the transition from normal and pre‐invasive lesions to invasive cancers, where ER β was lost in 21% of cases. This was more pronounced in invasive ductal than in lobular carcinomas, a significantly higher proportion of which were ER β‐positive (74% compared with 91%, respectively, p = 0.0004). Examination of paired primary cancers with their axillary lymph node metastases showed that if ER β was present in the primary tumour, it persisted in the metastasis. Treatment of ER β‐negative cell lines with DNA methyl transferase inhibitors restored ER β expression, providing experimental evidence that silencing of ER β in breast carcinomas could be due to promoter hypermethylation. These results suggest that loss of ER β expression is one of the hallmarks of breast carcinogenesis and that it may be a reversible process involving methylation. Copyright © 2003 John Wiley & Sons, Ltd.