bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of recombinant porcine IGFBP‐3 on IGF‐I and long‐R3‐IGF‐I‐stimulated proliferation and differentiation of L6 myogenic cells
Authors: Xi G. , Kamanga‐Sollo E. , Pampusch M.S. , White M.E. , Hathaway M.R. , Dayton William R.
Published: March 2004

Insulin‐like growth factor (IGF)‐I stimulates both proliferation and differentiation of myogenic precursor cells. In vivo, IGFs are bound to one of the members of a family of six high‐affinity IGF binding proteins (IGFBP 1–6) that regulate their biological activity. One of these binding proteins, IGFBP‐3, affects cell proliferation via both IGF‐dependent and IGF‐independent mechanisms and it has generally been shown to suppress proliferation of cultured cells; however, it also may stimulate proliferation depending upon the cell type and the assay conditions. Cultured porcine embryonic myogenic cells (PEMCs) produce IGFBP‐3 and its level drops significantly immediately prior to differentiation. Additionally, IGFBP‐3 suppresses both IGF‐I and Long‐R3‐IGF‐I‐stimulated proliferation of embryonic porcine myogenic cells. In this study, we have examined the effects of recombinant porcine IGFBP‐3 (rpIGFBP‐3) on IGF‐I‐ and Long‐R3‐IGF‐I‐stimulated proliferation and differentiation of the L6 myogenic cell line. L6 cells potentially provide a good model for studying the actions of IGFBP‐3 on muscle because they contain no non‐muscle cells and they do not produce detectable levels of IGFBP‐3. RpIGFBP‐3 suppresses both IGF‐I and Long‐R3‐IGF‐I‐stimualted proliferation of L6 cells, indicating that it suppresses proliferation via both IGF‐dependent and IGF‐independent mechanisms. Our data also show that rpIGFBP‐3 causes IGF‐independent suppression of proliferation without increasing the level of phosphosmad‐2 in L6 cultures. Additionally, rpIGFBP‐3 suppresses IGF‐I‐stimulated differentiation of L6 cells. In contrast, however, rpIGFBP‐3 does not suppress Long‐R3‐IGF‐I‐stimulated differentiation. This suggests that rpIGFBP‐3 does not have IGF‐independent effects on L6 cell differentiation. © 2004 Wiley‐Liss, Inc.
Characterization of the biological activities of uridine diphosphate in human dendritic cells: Influence on chemotaxis and CXCL8 release
Authors: Idzko Marco , Panther Elisabeth , Sorichter Stephan , Herouy Yared , Berod Luciana , Geissler Michael , Mockenhaupt Maja , Elsner Peter , Girolomoni Giampiero , Norgauer Johannes
Published: March 2004

Uridine nucleotides are endogenous nucleotides which are released into the extracellular space from mechanical stressed endothelial and epithelial cells as well as lipopolysaccharide (lps)‐stimulated monocytes. Here, we studied the biological activity of the selective purinoreceptor P2Y6 (P2YR6) agonist Uridine 5′diphosphate (UDP) as well as the P2YR2‐ and P2YR4‐activating uridine 5′triphosphate (UTP) on human dendritic cells (DC). These cells in their immature state have the ability to migrate from blood to peripheral target sites where they sense dangerous signals and capture potential antigens. Moreover, mature DC induce innate immune responses and migrate from peripheral tissues to secondary lymphoid organs in order to activate naive T cells and initiate adaptive immunity. Here, we were able to show that uridine nucleotides stimulated Ca2+ transients, actin polymerization, and chemotaxis in immature DC. Experiments with pertussis toxin, the stable pyrimidine agonist uridine 5′‐O‐(2‐thiodiphosphate) (UDPγS) and receptor antagonists, as well as desensitization studies suggested that these uridine nucleotides activities were mediated by different Gi protein‐coupled receptors. During lps‐induced maturation, DC lost their ability to respond towards uridine nucleotides with these activities. Instead, UDP, but not UTP, stimulated the release of the CXC‐chemokine 8 (CXCL8) from mature DC in a reactive blue sensitive manner. Moreover, our study indicates that UDP stimulates different signaling pathways in immature and mature DC in order to favor the accumulation of immature DC and to augment the capacity to secrete CXCL8 in mature DC. © 2004 Wiley‐Liss, Inc.
Optimized procedures for microarray analysis of histological specimens processed by laser capture microdissection
Authors: Upson John J. , Stoyanova Radka , Cooper Harry S. , Patriotis Christos , Ross Eric A. , Boman Bruce , Clapper Margie L. , Knudson Alfred G. , Bellacosa Alfonso
Published: March 2004

Analysis of cell‐specific gene expression patterns using microarrays can reveal genes that are differentially expressed in diseased and normal tissue, as well as identify genes associated with specialized cellular functions. However, the cellular heterogeneity of the tissues precludes the resolution of expression profiles of specific cell types. While laser capture microdissection (LCM) can be used to obtain purified cell populations, the limited quantity of RNA isolated makes it necessary to perform an RNA amplification step prior to microarray analysis. The linearity and reproducibility of two RNA amplification protocols—the Baugh protocol (Baugh et al., 2001, Nucleic Acids Res 29:E29) and an in‐house protocol have been assessed by conducting microarray analyses. Cy3‐labeled total RNA from the colorectal cell line Colo‐205 was compared to Cy5‐labeled Colo‐205 amplified RNA (aRNA) generated with each of the two protocols, using a human 10K cDNA array. The correlation of the gene intensities between amplified and total RNA measured in the two channels of each microarray was 0.72 and 0.61 for the Baugh protocol and the in‐house protocol, respectively. The two protocols were further evaluated using aRNA obtained from normal colonic crypt cross‐sections isolated via LCM. In both cases a microarray profile representative of colonic mucosa was obtained; statistically, the Baugh protocol was superior. Furthermore, a substantial overlap between highly expressed genes in the Colo‐205 cells and colonic crypts underscores the reliability of the microarray analysis of LCM‐derived material. Taken together, these results demonstrate that LCM‐derived tissue from histological specimens can generate abundant amounts of high‐quality aRNA for subsequent microarray analysis. J. Cell. Physiol. 201: 366–373, 2004. © 2004 Wiley‐Liss, Inc.
Use of RNA amplification in the optimal characterization of global gene expression using cDNA microarrays
Authors: Stoyanova Radka , Upson John J. , Patriotis Christos , Ross Eric A. , Henske Elizabeth P. , Datta Ketaki , Boman Bruce , Clapper Margie L. , Knudson Alfred G. , Bellacosa Alfonso
Published: March 2004

Microarray analysis of human tissue is frequently hindered by the limited amount of RNA available. Although amplification protocols can be utilized, the relative representation of transcripts present in the starting material must remain unaltered. In this study, 200 ng of total RNA derived from cultured renal epithelial cells from tuberous sclerosis complex (TSC) carriers and control individuals was amplified by in vitro transcription with T7 RNA polymerase. The resulting Cy‐labeled cDNAs (from total or amplified RNA (aRNA)) were analyzed as direct replicates and dye‐flips on slides containing 10,000 human cDNAs. The Pearson correlation coefficients for the direct replicate experiments were 0.80 (20 μg total RNA), 0.85 (40 μg total RNA), and 0.93 (2 μg of aRNA). Comparisons between the array data revealed that the majority of genes expressed in total RNA (97% for 20 μg and 85% for 40 μg) were also detected in aRNA. The correlation coefficient of the expression ratios for genes detected in both total RNA (40 μg) and aRNA was 0.63. Further, Student's t‐test indicated no significant difference (P = 0.83) between these ratios. These results indicate that the number of expressed genes detected with total RNA is proportional to the amount of RNA used and underscore the requirement of large amounts of total RNA for a comprehensive characterization of gene expression profiles. RNA amplification allows the detection of a large number of genes expressed in the starting RNA population without altering their relative intensities significantly. Thus, an RNA amplification step improves the quality of gene expression results obtained by microarray analysis. This study indicates that high quality microarray data can be generated from small amounts of RNA, including those extracted from limiting clinical samples and microdissected histological specimens. © 2004 Wiley‐Liss, Inc.
Bioremediation of DDT‐contaminated soil: enhancement by seaweed addition
Authors: Kantachote D , Naidu R , Williams B , McClure N , Megharaj M , Singleton I
Published: April 2004

DDT [1,1,1‐trichloro‐2,2‐bis (p‐chlorophenyl) ethane] is a major environmental pollutant and economical methods to remove DDT from the environment are required. In this work we used seaweed (dried and ground) to enhance DDT transformation in waterlogged soils. Initial daily rates of DDT biodegradation increased in the following order relating to the percentage by weight of added seaweed to soil 0.5 > 1 > 0 > 3 > 5 > 13 (w/w). The actual percentages of DDT biodegradation occurring within 6 weeks were 80, 64, 60, 50, 40 and 34 respectively. During soil incubation DDD [1,1,1‐trichloro‐2,2‐bis (p‐chlorophenyl) ethane] was the major metabolite found with small amounts of DDE [1,1,1‐trichloro‐2,2‐bis (p‐chlorophenyl) ethane] produced. The maximum amount of 4,4′‐dichlorobenzophenone (DBP) (2.5%) produced was found in soil amended with 0.5% (w/w) seaweed, indicating that further degradation of DDD occurred. High levels of dissolved organic carbon (DOC), between 309 and 509 mg kg−1 soil, were present in soil amended with 3–13% (w/w) seaweed immediately after seaweed addition. It is possible that the high levels of DOC in soils amended with larger amounts of seaweed significantly retarded DDT biodegradation, possibly due to binding of DDT to DOC and subsequently decreasing the bioavailability of DDT to soil microbes. Copyright © 2004 Society of Chemical Industry
Degradation of benzene, toluene ethylbenzene and p‐xylene (BTEX) in aqueous solutions using UV/H2O2 system
Authors: Daifullah Abdel Hakim AM , Mohamed Mohamed Mokhtar
Published: April 2004

The homogeneous degradation of benzene (B), toluene (T), ethylbenzene (E) and p‐xylene (X) (BTEX) was studied in aqueous solutions, at pH 3.0, of hydrogen peroxide (5.8 mM) under UV irradiation in a photoreactor equipped with a 300 nm lamp of light intensity 3.5 × 10−5 Ein L−1 min−1. BTEX was substantially degraded by the H2O2/UV system, with >90% disappearing in 10 min of irradiation. The decomposition of BTEX was studied either as single or as multi‐component systems. The effects of irradiation time, amounts of H2O2 in molar ratios, rate of degradation and competition between components were thoroughly examined. It can be stated that the rate of BTEX degradation in mixture was higher than those for the individual components due to external effects of the absorption of UV light by the mixture, and their effects on enhancing the formation of OH• radicals. The appropriate figure of merit, the electrical energy per mass (EE/M), was estimated at various molar ratios and it was confirmed that the best value was the one depicted for p‐xylene (0.065 kWh kg−1). A theoretical model for the degradation pathway was proposed. Copyright © 2004 Society of Chemical Industry
11th conference of the central european division e.V. of the international isotope society
Authors: Pounds S. , Hickey M. J. , Kingston L. P. , Mather A. N. , Wilkinson D. J. , Sidorov G. V. , Zverkov Yu. B. , Myasoedov N. F. , Karpenko I. L. , Shirokova E. A. , Yanvarev D. M. , Yasko M. V. , Skoblov Yu. S. , Susan A. B. , Myasoedov N. F. , Nagaev I. Y. , Shevchenko V. P. , Susan A. B. , Rotert G. , Krüger Jens , Fels Gregor , Wuest F. , Mäding P. , Zessin J. , Pleiß U. , Wüst F. , Bloom A. J. , Derdau V. , Oekonomopulos R. , Schubert G. , Andres H. , Burtscher P. , Metz Y. , Moenius Th. , Kaegi F. , Metz Y. , Rodriguez I. , Ruetsch R. , Janssen C. G. M. , Verreet B. , Lenoir H. A. C. , Thijssen J. B. A. , Stuerm Rolf P. , Krins Andreas , Rausch E. , Breyer M. , Hucke K. , Gaefke D. , Schmeer K.
Published: March 2004

S Pounds [PerkinElmer Life and Analytical Sciences, Inc., USA]—Preparation of carrier – free [Methyl‐3H] Methyl Nosylate and its Use as a Radiochemically Stable Methylating reagent.

DJ Wilkinson, AN Mather, MJ Hickey, LP Kingston [Astra Zeneca, UK]—Tritio‐Dehalogenation: New Variants on an Old Theme.

VG Sidorov, YB Zverkov, NF Myasoedov, IMG, Russia; IL Karpenko, EA Shirokova, DM Yanvarev, MV Yasko, YS Skoblov [EIMB, Russia], AB Susan, [IICH, USA]—The Syntheses of Labeled 3 ‘‐Azido‐3’‐Deoxythymidine Derivatives Displaying Anti‐HIV Activity.

NF Myasoedov, IY Nagaev, VP Shevchenko [IMG, Russia], AB Susan [IICH, USA], G Rotert [Abbott, USA]—Synthesis of Radiolabeled [3H]ABT‐578 for ADME Studies.

J Krueger, E Linnemann, G Fels [University of Paderborn, Germany]—(‐)‐[3H]Galanthamine – Labelling, Derivatization, and Application as Photoaffinity Probe.

F Wuest [Research Centre Rossendorf, Germany]—Carbon‐11 Labeled Compounds in the Development of Pharmaceuticals.

P Maeding, J Zessin, F Wüst [Research Centre Rossendorf, Germany], U Pleiss [Bayer HealthCare AG, Germany]—11C‐Labeling of a Taxane Derivative by [1‐11C] Acetylation.

J Bloom [Amersham Biosciences, UK]—The Preparation of 2‐Methyl [ring‐2‐14C] benzyl chloride.

V Derdau, R Oekonomopulos, G Schubert, H Heitsch [Aventis Pharma Deuschland GmbH, Germany]—Synthesis of 14C Labeled Angiotensin‐(1‐7)‐Receptor Agonist AVE 0991.

H Andres, P Burtscher, Y Metz, T Moenius [Novartis Pharma AG, Switzerland]—C‐14 Labeling of the β‐Amino Carboxyl Moiety–Alternatives to the Acrylate Approach.

F Kaegi, Y Metz, I Rodriguez, R Ruetsch [Novartis Pharma AG, Switzerland]—Effective Carbon‐14 Labelling under Microwave Irradiation.

CGM Janssen, B Verreet, HAC Lenoir, JBA Thijssen [Johnson & Johnson, Belgium]—Stable Isotope Labeled Compounds as Internal Standards for LC‐MS/MS, Requirements and Some Synthetic Approaches.

RP Stuerm [SafPro AG, Switzerland]—Models for Calculating the Radiation Dose after Incorporation of 3H and 14C.

A. Krins [VKTA Nuclear Engineering and Analytics e.V., Germany]—Dosimetry of C‐14 Labeled Organic Compounds.

E Rausch [Raytest GmbH, Germany], M Breyer, K Hucke, D Gaefke, K Schmeer [Bayer HealthCare AG, Germany]—A New Option of 14C‐Detection in Combination with Micro HPLC.
Antennulary sensory organs in cyprids of Octolasmis and Lepas (Crustacea: Thecostraca: Cirripedia: Thoracica): A scanning electron microscopic study
Authors: Blomsterberg Mikkel , Høeg Jens T. , Jeffries William B. , Lagersson Niklas C.
Published: March 2004

Cypris larvae of the pedunculate barnacles Octolasmis angulata (Poecilasmatidae), Lepas australis, L. pectinata, and Dosima fascicularis (Lepadidae) were studied with scanning electron microscopy, focusing on the sensory setae and the attachment disc on the antennules. The antennules of O. angulata did not exhibit any remarkable trait, but carry the same number of setae as seen in most other thoracicans. The third segment is bell‐shaped and quite distinct from the second and its attachment disc is surrounded by a skirt. We found several potential synapomorphies in antennulary morphology between cyprids of the lepadid species but none of them were shared with the cyprids of Octolasmis; the list of unique lepadid characters includes: one additional, preaxial seta on the second segment; multiple similar (up to eight) postaxial setae (PS3) on the third segment, unlike all other thoracicans, where there is only a single PS3; the third segment consists almost entirely of the attachment disc, which is distended and surrounded by two parallel rows of radial setae; on the fourth segment the terminal seta E is diminutive. We found no traits in cyprids of Octolasmis that seem to be adaptations to their attachment site within the branchial chamber of swimming crabs and, in particular, no similarities with cyprids of rhizocephalan barnacles, many of which also attach in the gill chamber. The synapomorphies between cyprids of the lepadid species may be adaptations to their life in the neuston. J. Morphol. 260:141–153, 2004 © 2004 Wiley‐Liss, Inc.
Growth and molting in epizoic pedunculate barnacles genus Octolasmis (Crustacea: Thecostraca: Cirripedia: Thoracica)
Authors: Blomsterberg Mikkel , Glenner Henrik , Høeg Jens T.
Published: March 2004

Scanning electron microscopy, light microscopy, and histology were used to study growth in species of the pedunculate barnacle genus Octolasmis (O. angulata, O. cor, O. californiana, O. mülleri). These species are epizoic in the gill chamber of portunid crabs and have highly reduced capitular shell plates, with large areas of general cuticle in between. The external integument grows by means of a system of narrow growth zones, one encircling the peduncle and a Y‐shaped system on either side of the capitulum. Growth is by a regular series of molts, but shedding of old cuticle and production of new layers is entirely restricted to the growth zones. Just prior to ecdysis, the new cuticle lies in a highly folded fashion beneath the old cuticle that is about to be shed. At ecdysis, the old cuticle breaks along the margins of the growth zones and the resulting scars remain as a system of “ecdysial lines” along either side of the zone. Once exposed after ecdysis, the new cuticle remains as a part of the permanent external integument. The growth zones divide the externa into five cuticular areas, two on the peduncle and three on the capitulum. The calcareous shell plates (carina, paired scuta, and, when present, paired terga) all lie within the capitular regions and the ecdysial lines pass across, not around, these mineralized areas. The number, relative spacing, and topology of the ecdysial lines form a record of the growth history of the specimen. These and other growth patterns demonstrate that size increase is due to the formation of new cuticle by molting in the growth zones, while expansion of the shell plates by mineralization follows only after production of the new cuticle. Thus, although specialized, growth in Octolasmis still complies with the general crustacean model, complicated only by the mineralization of parts of the capitular cuticle into shell plates. The results are compared with the very scarce information on molting in other barnacles. We argue that at least the circular peduncular growth zone is omnipresent in the Cirripedia Thoracica. J. Morphol. 260:154–164, 2004. © 2004 Wiley‐Liss, Inc.
Differentiation of the cardiac outflow tract components in alevins of the sturgeon Acipenser naccarii (Osteichthyes, Acipenseriformes): Implications for heart evolution
Authors: Guerrero Alejandro , Icardo José M. , Durán Ana C. , Gallego Alejandro , Domezain Alberto , Colvee Elvira , Sans‐Coma Valentín
Published: March 2004

Previous work showed that in the adult sturgeon an intrapericardial, nonmyocardial segment is interposed between the conus arteriosus of the heart and the ventral aorta. The present report illustrates the ontogeny of this intermediate segment in Acipenser naccarii. The sample studied consisted of 178 alevins between 1 and 24 days posthatching. They were examined using light and electron microscopy. Our observations indicate that the entire cardiac outflow tract displays a myocardial character during early development. Between the fourth and sixth days posthatching, the distal portion of the cardiac outflow tract undergoes a phenotypical transition, from a myocardial to a smooth muscle‐like phenotype. The length of this region with regard to the whole outflow tract increases only moderately during subsequent developmental stages, becoming more and more cellularized. The cells soon organize into a pattern that resembles that of the arterial wall. Elastin appears at this site by the seventh day posthatching. Therefore, two distinct components, proximal and distal, can be recognized from the fourth day posthatching in the cardiac outflow tract of A. naccarii. The proximal component is the conus arteriosus, characterized by its myocardial nature and the presence of endocardial cushions. The distal component transforms into the intrapericardial, nonmyocardial segment mentioned above, which is unequivocally of cardiac origin. We propose to designate this segment the “bulbus arteriosus” because it is morphogenetically equivalent to the bulbus arteriosus of teleosts. The present findings, together with data from the literature, point to the possibility that cells from the cardiac neural crest are involved in the phenotypical transition that takes place at the distal portion of the cardiac outflow tract, resulting in the appearance of the bulbus arteriosus. Moreover, they suggest that the cardiac outflow tract came to be formed by a bulbus arteriosus and a conus arteriosus from an early period of the vertebrate evolutionary story. Finally, we hypothesize that the embryonic truncus of birds and mammals is homologous to the bulbus arteriosus of fish. J. Morphol. 260:172–183, 2004. © 2004 Wiley–Liss, Inc.
Atrial natriuretic peptide (ANP) system in the lung of Rana esculenta
Authors: Tei Simonetta , Di Rosa Ines , Clarioni Romina , Vagnetti Daniela
Published: March 2004

The atrial natriuretic peptide (ANP)‐system was examined in Rana esculenta lung with cytochemical and immunocytochemical methods. The results showed a cellular type that synthesizes the hormone and the presence of receptors in various components of the lung. The lung, therefore, produces ANP and at the same time is a target organ for the hormone. ANP may play an important physiological role in pulmonary function and in protecting against pulmonary edema. J. Morphol. 260:184–192, 2004. © 2004 Wiley‐Liss, Inc.
Induction and improved embryonic development by the nucleus of pander in associated avian blastoderm parts: Influence of δ or γ ooplasm
Authors: Callebaut Marc , Van Nueten Emmy , Harrisson Fernand , Bortier Hilde
Published: March 2004

After placing in vitro, central subgerminal ooplasm (containing a central nucleus of Pander) from a quail germ disc of a prelaid egg (before symmetrization) on the upper layer of an isolated chicken antisickle, we observed the induction of a radially oriented preneural plate (without interference of chordamesoblast). This observation suggests the primary existence during the period of symmetrization in utero of an until now unknown temporospatially linked “vertical” effect, emanating from the nucleus of Pander, on the parallel (pre)neural plate anlage forming part of the area centralis in the overlying blastoderm. For comparison, we “sandwiched” in vitro a quail sickle endoblast fragment between the deep side of the upper layer of an isolated chicken antisickle region and a central subgerminal ooplasmic mass. This resulted in a colonization of the subgerminal ooplasmic mass by quail sickle endoblast cells followed by improved neurulation and/or gastrulation phenomena. The latter never occurs in the absence of central subgerminal ooplasm. In both types of experiments there seems to exist a common link between the observed induction phenomena: the presence of δ ooplasm in the involved deep structures. Indeed, the nucleus of Pander contains δ ooplasm as well as the structures derived from it, i.e., endophyll with primordial germ cells (Callebaut [1987] Arch Biol (Brux) 98:441–473) and sickle endoblast‐derived cells after colonization of the neighboring central ooplasm (present study). Therefore, we think that the preneural plate‐inducing effect observed after placing a nucleus of Pander on the antisickle region is due to the presence of a factor in the δ ooplasm that diffuses in the neighborhood. The appearance of gastrulation phenomena in the second type of experiment seems to be due to colonization of the more peripheral part of the central subgerminal ooplasm containing the more superficial and peripheral γ ooplasm in which Rauber's sickle material can develop. This suggests that the kind of involved ooplasm (δ or γ) can predetermine the inductive activity of the deep structures that contain it: the central part of the nucleus of Pander and/or endophyll for preneurulation phenomena and sickle endoblast (in the presence of central subgerminal ooplasm) for gastrulation and/or neurulation phenomena. J. Morphol. 260:201–208, 2004. © 2004 Wiley‐Liss, Inc.
Muscles of the pes of hylid frogs
Authors: Burton Thomas C.
Published: March 2004

Complete or partial dissection of the foot musculature of 404 hylid frogs representing 247 species and 33 genera, along with representatives of eight other families, revealed a number of apomorphic characters that distinguish the hyloid frogs (Hylidae plus Allophryne and Centrolenidae) from other bufonoid frogs. Additional characters were found to define some of the hylid subfamilies. Addition of characters from the foot musculature to Duellman's (2001) phylogenetic tree of the hyloids produced a tree in which Allophryne and Centrolenidae are nested within Hylidae. Support was found for the monophyly of the 30‐chromosome group within Hyla, and for a large number of the groups that comprise “Boana,” viz., the Hyla albomarginata, H. albopunctata, H. boans (except H. vasta), H. geographica, and H. pulchella groups, but foot muscle characters provide no information relating to relationships of the West Indies hylines. J. Morphol. 260:209–233, 2004. © 2004 Wiley‐Liss, Inc.
Sexual dimorphism of the flounder Bothus robinsi (Pisces: Bothidae)
Authors: Kobelkowsky Abraham
Published: March 2004

The anatomical organization of the reproductive system of the flounder, Bothus robinsi, is similar to other fish in the order Pleuronectiformes. Accentuated, external secondary sexual characters are observed in males such as increased body length, larger left pectoral fin, and greater interorbital distance. As a qualitative character, the rostral spine, which is part of the maxillary bone, is pronounced. The interorbital distance implies noticeable internal sexual differences, such as the broadening of the left frontal and lateral ethmoid bones, and a greater length of the oblique muscles of both eyes, the optic nerves, and the left olfactory nerve. Five male specimens examined had female external secondary sexual characters. J. Morphol. 260:165–171, 2004. © 2004 Wiley‐Liss, Inc.
Vasculature of the parotoid glands of four species of toads (bufonidae: bufo)
Authors: Hutchinson Deborah A. , Savitzky Alan H.
Published: March 2004

The parotoid glands of toads (Bufonidae) consist of large aggregations of granular glands located between the otic region of the skull and the scapular region. To determine the circulatory pattern of these glands, we perfused the vascular systems of Bufo alvarius, B. marinus, B. terrestris, and B. valliceps with either India ink or Microfil, a fine latex. The perfused glands were studied by gross dissection, microscopic examination, and histology. The vascular patterns of the parotoid glands were compared to the arrangement of vessels in the dorsal skin of Rana sphenocephala (Ranidae), a frog that lacks parotoid glands. The parotoid glands of the four species of toads are supplied with blood by the lateral and dorsal cutaneous arteries and are drained by one or more branches of the internal jugular vein. The dorsal cutaneous artery supplies most of the blood to the parotoid glands in B. terrestris and B. valliceps. In B. alvarius and B. marinus, both the lateral and dorsal cutaneous arteries serve major roles in the blood supply of the glands. These patterns of blood flow have not been described previously for parotoid glands and conflict with earlier accounts for B. alvarius and B. marinus. The arteries and veins associated with the parotoid glands of toads are present in R. sphenocephala, but are arranged differently. In R. sphenocephala, the lateral cutaneous artery supplies the dorsal and lateral skin posterior to the shoulder region, whereas the dorsal cutaneous artery supplies the skin of the shoulder region. In toads, both the lateral and dorsal cutaneous arteries supply the skin of the shoulder region and ramify into subcutaneous capillaries that surround the secretory units of the parotoid glands. Extensive vasculature presumably is important for delivering cholesterol and other precursor molecules to the parotoid glands, where those compounds are converted into toxins. J. Morphol. 260:247–254, 2004. © 2004 Wiley‐Liss, Inc.
Ultrastructure of the calcium‐sequestering gastrodermal cell in the hydroid Hydractinia symbiolongicarpus (Cnidaria, Hydrozoa)
Authors: Dandar‐Roh Alicia M. , Rogers‐Lowery Constance L. , Zellmann Erhard , Thomas Mary Beth
Published: March 2004

Large, free‐floating crystals of calcium carbonate occur in vacuoles of gastrodermal cells of the hydroid Hydractinia symbiolongicarpus. Here, morphological details about the process by which these cells accumulate and sequester calcium are provided by a cytochemical method designed to demonstrate calcium at the ultrastructural level. Electron‐dense material presumably indicative of the presence of calcium was EGTA‐sensitive and was shown by parallel electron energy loss spectroscopy (EELS) and energy spectroscopic imaging (ESI) to contain calcium. Calcium occurred in only one cell type, the endodermally derived gastrodermal cell. In these cells, the electron‐dense material appeared first as a fine precipitate in the cytosol and nucleus and later as larger deposits and aggregates in the vacuole. During the life cycle, gastrodermal cells of the uninduced planula and the planula during metamorphic induction sequestered calcium. In primary polyps and polyps from established colonies, gastrodermal cells sequestered calcium, but the endodermal secretory cells did not. Our observations support the hypothesis that gastrodermal cells function as a physiological sink for calcium that enters the organism in conjunction with calcium‐requiring processes such as motility, secretion, and metamorphosis. J. Morphol. 260:255–270, 2004. © 2004 Wiley‐Liss, Inc.
Simultaneous determination of Δ9‐tetrahydrocannabinol, 11‐hydroxy‐Δ9‐tetrahydrocannabinol and 11‐nor‐9‐carboxy‐ Δ9‐tetrahydrocannabinol in human plasma by high‐performance liquid chromatography/tandem mass spectrometry
Authors: Maralikova Barbora , Weinmann Wolfgang
Published: April 2004

A rapid and sensitive method for the simultaneous confirmatory analysis of three forensic most relevant cannabinoids, Δ9‐tetrahydrocannabinol (THC), 11‐hydroxy‐Δ9‐tetrahydrocannabinol (11‐OH‐THC) and 11‐nor‐9‐carboxy‐Δ9‐tetrahydrocannabinol (THC‐COOH), by means of high‐performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) in human plasma was developed and fully validated. Sample clean‐up was performed by automated silica‐based solid‐phase extraction and the separation was carried out using a PhenylHexyl column (50 × 2 mm i.d., 3 µm) and acetonitrile–5 mM ammonium acetate gradient elution. Data were acquired with an API 3000 LC/MS/MS system equipped with a turboionspray interface and triple quadrupole mass analyzer using positive electrospray ionization and multiple reaction monitoring. Two MS/MS transitions for each substance were monitored and deuterated analogues of analytes were used as internal standards for quantitation. The limit of quantitation was 0.8 ng ml−1 for THC, 0.8 ng ml−1 for 11‐OH‐THC and 4.3 ng ml−1 for THC‐COOH and linearity with a correlation coefficient r2 = 0.999 was achieved up to 100 ng ml−1 for THC and 11‐OH‐THC and 500 ng ml−1 for THC‐COOH. The limits of detection were 0.2 ng ml−1 for THC, 0.2 ng ml−1 for 11‐OH‐THC and 1.6 ng ml−1 for THC‐COOH. The developed LC/MS/MS method was also successfully used for the determination of THC‐COOH‐glucuronide, the phase II metabolite of THC‐COOH. Copyright © 2004 John Wiley & Sons, Ltd.
C6 cells express a sodium‐calcium exchanger/GM1 complex in the nuclear envelope but have no exchanger in the plasma membrane: Comparison to astrocytes
Authors: Xie Xin , Wu Gusheng , Ledeen Robert W.
Published: April 2004

Previous work demonstrated the presence of an isoform of Na+/Ca2+ exchanger in the nuclear envelope of neurons and NG108‐15 cells that is tightly associated with GM1 ganglioside and potentiated by the latter. This contrasted with the Na+/Ca2+ exchanger(s) in the plasma membrane, which were suggested to associate more loosely with GM1. To study these aspects of Na+/Ca2+ exchanger expression in nonneuronal neural cells, we have examined nuclear and plasma membrane exchanger patterns in astrocytes and C6 cells, a glia‐derived line. We find both cell types contain the tightly associated exchanger/GM1 complex in the nuclear envelope but, surprisingly, only astrocytes possess Na+/Ca2+ exchanger activity in the plasma membrane. This is the first reported example of a cell (C6) with Na+/Ca2+ exchangers in the nuclear envelope but not in the plasma membrane. RT‐PCR established the presence of the NCX1 subtype in C6 cells and both NCX1 and NCX2 in astrocytes. Comparison was made with NG108‐15 cells, which have Na+/Ca2+ exchangers in both nuclear and plasma membranes, and Jurkat cells, which have no Na+/Ca2+ exchanger in either membrane. Culturing of C6 cells in the presence dibutyryl‐cAMP caused upregulation of a high molecular weight isoform of the exchanger together with GM1 in the nuclear envelope, resulting in significant elevation of Na+/Ca2+ exchanger activity in the latter. Application of exogenous GM1 to nuclei from non‐treated cells also potentiated exchanger activity, although to a lesser degree. The Na+/Ca2+ exchanger/GM1 complex occurs in the inner membrane of the nuclear envelope, suggesting a functional role in transferring Ca2+ between nucleoplasm and the envelope lumen. © 2004 Wiley‐Liss, Inc.
γ‐Aminobutyric acid type B receptors facilitate L‐type and attenuate N‐type Ca2+ currents in isolated hippocampal neurons
Authors: Carter Thomas J. , Mynlieff Michelle
Published: April 2004

Activation of presynaptic γ‐aminobutyric acid type B (GABAB) receptors inhibits neurotransmitter release at many synapses (both excitatory and inhibitory), and activation of postsynaptic GABAB receptors leads to a general inhibition of the postsynaptic cell in mature neurons. Although the action of GABAB receptors at the soma of excitatory hippocampal pyramidal cells has been resolved to be regulation of a potassium or calcium conductance, it is not clear that all neurons in the hippocampus demonstrate similar effects of GABAB receptor activation. In the current study, GABAB receptor‐mediated effects on calcium currents in acute cultures composed of heterogeneous cells from the superior region of neonatal hippocampi were studied. In 54.5% of cells, the GABAB receptor agonist baclofen (10 μM) attenuated the whole‐cell calcium current by 21.0% ± 1.1%. In 29.9% of cells, baclofen facilitated the calcium current by 43.5% ± 8.1%. The component of current attenuated by baclofen was blocked by the N‐type calcium channel antagonist ω‐conotoxin GVIA (3 μM). The component of current facilitated by baclofen was blocked by the L‐type channel antagonist nimodipine (20 μM). For cells that showed calcium current facilitation, baclofen shifted the half‐maximal activation by approximately –14 mV. The data indicate that activation of GABAB receptors in neurons of the superior hippocampus attenuates current through N‐type channels and facilitates current through L‐type channels. The two opposing effects of GABAB receptor activation may reflect the heterogeneity of the cultured cells or may be a developmentally regulated phenomenon. © 2004 Wiley‐Liss, Inc.
Hot‐stage Raman spectroscopic study of the thermal decomposition of saléeite
Authors: Frost Ray L. , Weier Matt L.
Published: April 2004

Hot‐stage Raman spectroscopy was used to study the changes in structure of the mineral saléeite, Mg(UO2)2(PO4)2·10H2O, during dehydration. Raman spectra were obtained using a Renishaw Raman microscope coupled with a Linkam thermal stage. Temperatures for Raman spectroscopic analysis were selected by studying the high‐resolution thermogravimetric analysis of saléeite. Five stages of dehydration are observed at 43, 73, 87, 231 and 376°C with the loss of 3, 3, 2, 1 and 1 mol of water, respectively. Three antisymmetric PO4 stretching vibrations are observed at 1007, 994 and 980 cm−1. No symmetric stretching vibration is observed until after significant dehydration has occurred at 75°C, when a low‐intensity band at 927 cm−1 is observed. Two bands at 843 and 827 cm−1 are attributed to the symmetric stretching modes of the two UO2 vibrational modes resulting from the two non‐equivalent UO bonds. The low‐intensity band at 894 cm−1 is assigned to the UO2 antisymmetric stretching mode. The complexity that is observed in the ν3 antisymmetric stretching region of the PO4 units is also observed in the PO4 ν2 bending region. Four bands are observed at 471, 446, 405 and 376 cm−1. Two bands observed at 283 and 234 cm−1 are assigned to the (UO2)2+ bending modes. After dehydration, it is suggested that the structure loses its distortion, takes on a tetragonal structure and hence the Raman spectra become less complex upon thermal treatment. Copyright © 2004 John Wiley & Sons, Ltd.
Performance evaluation of cylindrical fiber optic light diffusers for biomedical applications
Authors: Vesselov Leonid M. , Whittington William , Lilge Lothar
Published: April 2004

Background and Objectives

Dosimetry for intracavity and interstitial light delivery requires next to the knowledge of tissue optical properties and models describing light propagation in tissue also exact knowledge of the spatial light source emission characteristics. However, the emission characteristics of cylindrical diffusers are often ill defined by the manufacturer, and not regularly determined by the end user, thus limiting the attainable dosimetry accuracy.

Study Design/Materials and Methods

Commercial cylindrical diffusers, with active diffusive lengths of 1–2 cm and outer diameters of ≤1 mm, were evaluated regarding their photometric emission characteristics. In addition to traditional tests of homogeneity such as light intensity emitted along the diffuser length and around its circumference (polar angle), azimuth emission was also measured.

Results

It was demonstrated that the light emission distribution is specific to the diffuser manufacturer, and while good polar isotropy is often attained, azimuth isotropy can vary by more than a factor of 5. In hollow organs the latter can result in over treatment of tissue distal to the actual placement of the cylindrical diffusers.

Conclusions

To enable light dosimetry and treatment planning for applications such as photodynamic therapy or interstitial laser hyperthermia or photocoagulation, standardization of emission properties reporting for optical fiber diffusers is required. Lasers Surg. Med. 34:348–351, 2004. © 2004 Wiley‐Liss, Inc.
Determination of the dynamics of restored teeth by 3D electronic speckle pattern interferometry
Authors: Lang H. , Rampado M. , Müllejans R. , Raab W.H.‐M.
Published: April 2004

Background and Objectives

The difficulties typically encountered in studying the effects of restorations on tooth reinforcement are often due to the 3‐dimensional (3D) nature of deformation. Therefore, electronic 3D‐Speckle‐Interferometry (3D‐ESPI) was used to assess the impact of different restorative materials on the deformation of teeth.

Study Design/Materials and Methods

Small and large MOD‐preparations in extracted premolars were restored with gold inlays, ceramic inlays, composite resin inlays, amalgam, or composite resin. The restorations and cusps were loaded (90 N) and the deformation was assessed by 3D‐ESPI.

Results

Teeth with small restorations were deformed only slightly and the differences between the materials were minimal (P>0.05). In contrast, teeth with large restorations displayed material‐specific deformation patterns: (a) all materials led to decreased deformation as compared with unfilled teeth, (b) elastic materials caused only local deformation, (c) non‐adhesive materials resulted in translation of the restoration and marginal discrepancies, (d) adhesive inlays brought about increased deformation of the luting resin composite, (e) loading of the cusps caused higher deformation than loading of the restorations, and (f) bonded restorations stabilized the cusps.

Conclusions

The results show that the deformation pattern of restored teeth is material‐specific but the extent of deformation is primarily limited by the remaining tooth substance. Lasers Surg. Med. 34:300–309, 2004. © 2004 Wiley‐Liss, Inc.
Analysing absence behaviour using event history models
Authors: Barmby Tim , Sibly Suzyrman
Published: March 2004

This paper analyses the absence behaviour of a group of industrial workers. Part of their remuneration scheme comprises an experience rated sick‐pay scheme (linking level of sickpay to past absence) which determines the cost of a day's absence for a worker, both contemporaneously and in terms of expected future cost. This cost is explicitly computed for each worker and we show that this cost is negatively related to absence. Using an event history model with a Markov structure for the absence histories the size of this effect is shown to depend on the state occupied. Copyright © 2004 John Wiley & Sons, Ltd.
Endogenous R&D spillovers and locational choice with discriminatory pricing
Authors: Piga Claudio , Poyago‐Theotoky Joanna
Published: March 2004

We present a model of spatial price discrimination where R&D spillovers are endogenous as they depend on firms' location. We establish that both the distance between locations and R&D efforts are an increasing function of the transportation cost coefficient and show that there is a continuum of cases where firms will choose an intermediate location. The managerial implications from the model are discussed using examples of marketing behavior by Internet retailers. Copyright © 2004 John Wiley & Sons, Ltd.
Fixed cost, marginal cost, and the decision to buy or make
Authors: E. Hegji Charles
Published: March 2004

The paper builds a formal model of the costs and benefits of producing intermediate goods internally as compared to buying partially produced inputs on the open market. The model centers on the link between the purchase of assets specific to a production process and the mean and variance of profits from the purchase. The central point of the paper is that even though purchases of assets specific to a production process can have an ambiguous impact on profits of the decision to make, the purchase of such assets has a tendency to reduce the variability of profits. This trade‐off is at the heart of decision to buy or make. Copyright © 2004 John Wiley & Sons, Ltd.
Alliances and cost declaration
Authors: Gensemer Susan , Kanagaretnam Kiridaran
Published: March 2004

Our model explores the co‐existence of both cooperative and competitive behaviors in an alliance setting. Specifically, when alliance partners cooperatively choose observable contributions given reported costs, their self‐interested behavior may lead to misreporting of costs related to these contributions.

We show that truthful cost reporting by an alliance firm is valuable, thereby establishing that accurate cost reports are a determinant of successful alliance performance. Next we show that an alliance firm's cost reporting behavior may depend on the type of payoffs it receives from alliance, i.e., a share of profit or revenue, and also on the type of relationship between contributions, i.e., whether they are technical substitutes or complements. While we have focussed on highlighting factors which underlie cost misreporting, this study also may serve as a basis for investigating ways to design contracts to diminish the loss an alliance suffers from cost misreporting of the firms, thus increasing the chance that an alliance will be successful. Copyright © 2004 John Wiley & Sons, Ltd.
R&D spillovers and strategic delegation in oligopolistic contests
Authors: Kräkel Matthias
Published: March 2004

Considering oligopolistic contests with R&D spillovers and strategic delegation three results can be obtained: (1) There exist multiple asymmetric equilibria where one owner highly favors sales as a basis for his manager's incentives which drives the other firm out of the market. (2) If R&D spillovers are zero, a managerial firm will have a strong strategic advantage when competing with an entrepreneurial firm. If both owners endogenously decide about delegation, each owner's dominant strategy will be to delegate, given that the manager's reservation value is not too large. (3) If R&D spillovers are maximal, collusive market outcomes become very likely, which makes strategic delegation less important. Copyright © 2004 John Wiley & Sons, Ltd.
Causes and effects of multimarket activity from theory to empirical analysis
Authors: Vannoni Davide
Published: March 2004

In this paper some of the results emerged in the empirical literature on diversification are put into perspective against the background of a simple integrative model of multiproduct firms. By letting diversification strategies depend on the simultaneous play of four factors (demand relationships and technological links between goods, collusion within a market and across markets), the latter provides an illustrative framework which is useful to discuss how effectively the issue of ambiguous findings has been tackled in applied works. In some cases scholars have devoted substantial effort in order to build tests which can successfully discriminate among the different views on the causes and effects of diversification, while in other circumstances empirical investigations have been conducted with much less care. Other then criticising some of the methods used in the past, the paper provides a number of suggestions that can help guiding future empirical work on corporate diversification. Copyright © 2004 John Wiley & Sons, Ltd.
Neurotrophic activities of trk receptors conserved over 600 million years of evolution
Authors: Beck Gad , Munno David W. , Levy Zehava , Dissel Helga M. , van‐Minnen Jan , Syed Naweed I. , Fainzilber Mike
Published: April 2004

The trk family of receptor tyrosine kinases is crucial for neuronal survival in the vertebrate nervous system, however both C. elegans and Drosophila lack genes encoding trks or their ligands. The only invertebrate representative of this gene family identified to date is Ltrk from the mollusk Lymnaea. Did trophic functions of trk receptors originate early in evolution, or were they an innovation of the vertebrates? Here we show that the Ltrk gene conserves a similar exon/intron order as mammalian trk genes in the region encoding defined extracellular motifs, including one exon encoding a putative variant immunoglobulin‐like domain. Chimeric receptors containing the intracellular and transmembrane domains of Ltrk undergo ligand‐induced autophosphorylation followed by MAP kinase activation in transfected cells. The chimeras are internalized similarly to TrkA in PC12 cells, and their stimulation leads to differentiation and neurite extension. Knock‐down of endogenous Ltrk expression compromises outgrowth and survival of Lymnaea neurons cultured in CNS‐conditioned medium. Thus, Ltrk is required for neuronal survival, suggesting that trophic activities of the trk receptor family originated before the divergence of molluscan and vertebrate lineages approximately 600 million years ago. © 2004 Wiley Periodicals, Inc. J Neurobiol 60: 12–20, 2004
A comparative experiment in the consolidation of cremated bone
Authors: Rossi D. , De Gruchy S. , Lovell N. C.
Published: March 2004

This experiment assessed whether consolidation of cremated remains facilitated cross‐sectioning and grinding, which often are required for microstructural analyses such as the histomorphometric estimation of age and the examination of pathological lesions. Green, bovine femoral diaphyses were cremated at three temperature ranges (346–357°C; 610–755°C; 684–838°C) in an electric furnace and then consolidated with Acryloid B‐72 or Butvar B‐98 using simple brushing and immersion techniques. After consolidation was complete, bone pieces were cross‐sectioned and ground to a thickness of 100–120 μm. Results indicate that specimens treated with Acryloid B‐72 are harder and stronger than Butvar treated and untreated control specimens. Acryloid B‐72 is, therefore, recommended for the consolidation of cremated remains in preparation for microstructural analysis. Copyright © 2004 John Wiley & Sons, Ltd.