bluuebunny/crossref_metadata_2025 huggingface dataset:
c-kit Receptor Expression in Ewing’s Sarcoma: Lack of Prognostic Value but Therapeutic Targeting Opportunities in Appropriate Conditions
Authors: Scotlandi Katia , Manara Maria Cristina , Strammiello Rosaria , Landuzzi Lorena , Benini Stefania , Perdichizzi Stefania , Serra Massimo , Astolfi Alessia , Nicoletti Giordano , Lollini Pier-Luigi , Bertoni Franco , Nanni Patrizia , Picci Piero
Published: May 2003

Purpose: Autocrine/paracrine stimulation of c-kit has been recently observed in Ewing’s sarcoma (ES) cell lines. In this study, we tested the prognostic and therapeutic role of the receptor in this tumor.

Methods: One hundred one ES tumor biopsies were evaluated for the expression of c-kit by the avidin-biotin-peroxidase procedure. Effectiveness of STI-571 (Gleevec; Novartis, Basel, Switzerland), a selective inhibitor of specific tyrosine kinases, was analyzed with respect to in vitro growth and migration inhibition, as single agent or in combination with doxorubicin.

Results: Approximately 30% of patients expressed c-kit in their primary tumors. No significant association between the expression of the receptor and the clinical outcome was observed. In vitro growth of ES cell lines showing high levels of c-kit demonstrated limited inhibition by exposure to STI-571 (10 μmol/L is required to obtain 40% to 50% of growth inhibition). A decrease of stem-cell factor–mediated ES cell migration was also found. The drug acted additively with doxorubicin in inhibiting ES cell growth.

Conclusion: The negative prognostic findings and the limited in vitro therapeutic activity of STI-571 indicate that the putative aberrant signaling provided by c-kit overexpression may be dispensable for ES development and unlikely to constitute a critical therapeutic target. Accordingly, the dose of STI-571 required to give a significant ES growth inhibition is much higher than for those tumors in which mutations of c-kit constitute a relevant pathogenetic event. Nevertheless, in the subset of ES patients showing a high level of c-kit expression, the activity of the drug may be exploited in combination with standard therapy.
Differential Regulation of Proteasome-Dependent Estrogen Receptor α and β Turnover in Cultured Human Uterine Artery Endothelial Cells
Authors: Tschugguel Walter , Dietrich Wolf , Zhegu Zyhdi , Stonek Felix , Kolbus Andrea , Huber Johannes C.
Published: May 2003

Estrogen-induced loss of estrogen receptor (ER) α expression limits estrogen responsiveness in many target cells. However, whether such a mechanism contributes to changes in vascular endothelial ERα and/or ERβ levels is unclear. Using RT-PCR assays, we did not find any regulation of ERα or ERβ mRNA expression in human uterine artery endothelial cell (HUAEC) nuclear extracts on stimulation with 17β-estradiol for 1 or 2 h. By contrast, Western analysis on HUAEC extracts revealed that 17β-estradiol was capable of down-regulating both ERα and ERβ protein starting 1 h after treatment, an effect that can be blocked by pretreatment with tamoxifen as well as with the proteasome inhibitor lactacystin. The proteolysis inhibitors insulin, cycloheximide, and puromycin impede ERα, but not ERβ, turnover. Ubiquitin, but not its competitive inhibitor methyl-ubiquitin, induces rapid turnover of both ERs in a cell-free system of MCF-7 and HUAEC extracts. We, thus, propose the existence of estrogen-induced ER degradation that serves to control physiological responses in an estrogen target tissue, i.e. human vascular endothelium, by down- regulating ERα as well as ERβ through different proteasomal uptake mechanisms.
Progestagenic Effects of Tibolone on Human Endometrial Cancer Cells
Authors: Blok L. J. , De Ruiter P. E. , Kühne E. C. M. , Hanekamp E. E. , Grootegoed J. A. , Smid-Koopman E. , Gielen S. C. J. P. , De Gooyer M. E. , Kloosterboer H. J. , Burger C. W.
Published: May 2003

Tibolone, a synthetic steroid acting in a tissue-specific manner and used in hormone replacement therapy, is converted into three active metabolites: a Δ4 isomer (exerting progestagenic and androgenic effects) and two hydroxy metabolites, 3α-hydroxytibolone (3α-OH-tibolone) and 3β-OH-tibolone (exerting estrogenic effects). In the present study an endometrial carcinoma cell line (Ishikawa PRAB-36) was used to investigate the progestagenic properties of tibolone and its metabolites. This cell line contains progesterone receptors A and B, but lacks estrogen and androgen receptors.

When tibolone was added to the cells, complete conversion into the progestagenic/androgenic Δ4 isomer was observed within 6 d. Furthermore, when cells were cultured with tibolone or when the Δ4 isomer or the established progestagen medroxyprogesterone acetate was added to the medium, marked inhibition of growth was observed. Interestingly, 3β-OH-tibolone also induces some inhibition of growth. These growth inhibitions were not observed in progesterone receptor-negative parental Ishikawa cells, and progestagen-induced growth inhibition of PRAB-36 cells could readily be reversed using the antiprogestagen Org-31489. Upon measuring the expression of two progesterone-regulated genes (fibronectin and IGF-binding protein-3), tibolone, the Δ4 isomer and medroxyprogesterone acetate showed similar gene expression regulation.

These results indicate that tibolone, the Δ4 metabolite, and to some extent 3β-OH-tibolone exert progestagenic effects. Tibolone and most likely 3β-OH-tibolone are converted into the Δ4 metabolite.
Treatment of Type II Amiodarone-Induced Thyrotoxicosis by Either Iopanoic Acid or Glucocorticoids: A Prospective, Randomized Study
Authors: Bogazzi Fausto , Bartalena Luigi , Cosci Chiara , Brogioni Sandra , Dell’Unto Enrica , Grasso Lucia , Aghini-Lombardi Fabrizio , Rossi Giuseppe , Pinchera Aldo , Braverman Lewis E. , Martino Enio
Published: May 2003

Amiodarone-induced thyrotoxicosis (AIT) may occur either in the presence of underlying thyroid disease (type I AIT) or in apparently normal thyroid glands (type II AIT). Type II AIT, a destructive thyroiditis, often favorably responds to glucocorticoids. Iopanoic acid (IopAc) is an iodinated cholecystographic agent that inhibits deiodinase activity and reduces the conversion of T4 toT3. It has recently been reported that cholecystographic agents restore euthyroidism in patients with type II AIT. We describe the results of a prospective randomized study conducted in 12 patients with type II AIT treated with either iopanoic acid (group A, n = 6) or glucocorticoids (group B, n = 6). Serum free T3 levels normalized rapidly in both groups after 7 d, from 0.75 ± 0.20 ng/dl (11.5 ± 3.1 pmol/liter) to 0.46 ± 0.10 ng/d (7.1 ± 1.7 pmol/liter), P < 0.01, and from 0.58 ± 0.10 ng/dl (9.0 ± 1.2 pmol/liter) to 0.34 ± 0.03 ng/dl (5.2 ± 0.5 pmol/liter), P < 0.003, in groups A and B, respectively (P = NS). Serum free T4 levels reduced at 6 months in group B [from 2.70 ± 0.32 ng/dl (35.1 ± 4.1 pmol/liter) to 1.0 ± 0.04 ng/dl (13.4 ± 0.6 pmol/liter), P < 0.0001] but not in group A (from 2.90 ± 0.6 ng/dl (38.0 ± 7.5 pmol/liter) to 2.30 ± 0.4 ng/dl (35.6 ± 6.1 pmol/liter, P = 0.39; P = 0.005 group B vs. group A). All patients in both groups became euthyroid and had their amiodarone-induced destructive thyroiditis cured as defined by normalization of both serum free T4 and free T3 levels, during both drugs therapy. However, patients in group B were cured more rapidly than patients in group A (43 ± 34 d vs. 221 ± 111 d, respectively, P < 0.002). This study shows that, albeit both drugs are effective, glucocorticoids are probably the drug of choice for more rapidly curing type II AIT.
Personalised prescribing for asthma - is pharmacogenetics the answer?
Authors: Dewar Jane C , Hall Ian P
Published: May 2003

An individual's response to anti-asthma medication is likely to arise from a complex interaction between social, environmental and inherited factors. Studies indicate that genetic factors may account for 60–80% of the heterogeneity in treatment responsiveness in asthmatics. Identifying the genetic variants responsible may potentially lead to the development of novel treatments, improved effectiveness in the use of existing treatments and better prediction of efficacy in phase II and III trials. This article will briefly outline the current methods of identifying relevant treatment-responsive genes and their genetic variants. The pharmacogenetics of the main asthma treatment groups will then be reviewed in detail. Finally, the impact of pharmacogenetics on the pharmaceutical industry, and clinical practice in the future will be discussed.
Improvement of (+)-catechin inhibitory activity on human PMN respiratory burst by (+)-3-O-propionyl and (-)-3-O-valeryl substitution
Authors: Vuotto Maria Luisa , Miranda Rosario , Ritieni Alberto , Basile Adriana , Ricciardi Luca , Di Prisco Rocco , Nicolosi Giovanni , Mascolo Nicola
Published: May 2003

Catechins and their derivatives are abundant flavanols in the plant kingdom. Usually, catechin activity correlates with chemical structure. We hypothesized that by adding hydrophobic groups to the native catechin, we could ameliorate penetration of the cell and make the derivatives more active than native molecule in inhibiting polymorphonuclear leucocyte (PMN) oxidative burst. This study was designed to compare the antioxidant activity of native catechin with that of (+)-3-propionylcatechin and (-)-3-O-valerylcatechin esters by two cell-free colorimetric methods and by their effects on whole blood leucocytes as well as on isolated PMN chemiluminescence activity. The results showed that the colorimetric methods did not detect differences between catechins. On the contrary, cellular chemiluminescence studies showed that light emission by resting, as well as by phorbol myristate acetate (PMA)-stimulated PMNs and whole blood leucocytes was inhibited by catechin esters more intensively than native catechin. The compartmental chemiluminescence evaluation showed that the extracellular activity was similar with all catechins, while the intracellular activity was higher with esters. PMN pre-incubation, with catechins at various times before stimulation with PMA, enhanced the inhibitory activity of all compounds. Since the esterification with propionic or valeric acid increased the lipophilicity of (+)- catechin, we hypothesized that native and esterified catechins have different intracellular availability and therefore differ in effectiveness. An ancillary result obtained is that a single approach, chemical or cellular, is not sufficient to evaluate overall antioxidant activity in biological sytems. The results indicate that modified catechins may be very intriguing as possible future leucocyte modulating drugs, with possible applications in vascular and inflammatory diseases.
The polysaccharide from Tamarindus indica (TS-polysaccharide) protects cultured corneal-derived cells (SIRC cells) from ultraviolet rays
Authors: Raimondi L , Lodovici M , Guglielmi F , Banchelli G , Ciuffi M , Boldrini E , Pirisino R
Published: May 2003

The aim of this work was to investigate the possible protective effect of a new viscosising agent, TS-polysaccharide, on corneal-derived cells (SIRC) exposed to ultraviolet-B rays. To verify this, SIRC cells were first exposed, in the absence or in the presence of TS-polysaccharide (1% w/v), for 9 s at the UV-B source and then post-incubated for 45 min at 37°C. After this period the hydrogen peroxide (H2O2) accumulated in the medium and the concentration of 8-hydroxy-2′-deoxy-guanosine (8-OHdG) in cell DNA was measured. In addition, the amount of 3H-methyl-thymidine incorporated in cellular DNA was evaluated after 18 h from irradiation. Our results show that cells exposed to UV-B rays accumulate H2O2, and have higher levels of 8OHdG and a lower amount of 3H-methyl-thymidine incorporated in DNA than control cells. In the presence of TS-polysaccharide, the H2O2 and 8-OHdG accumulation, and the 3H-methyl-thymidine incorporation were significantly reduced with respect to the values measured in cells exposed in the absence of the polysaccharide. We propose a protective role of the polysaccharide in reducing UV-B derived DNA damage to eye cells. This finding could be of some clinical importance when the polysaccharide is used as a delivery system for ophthalmic preparations.
Butein suppresses myofibroblastic differentiation of rat hepatic stellate cells in primary culture
Authors: Woo Sun Wook , Lee Sung Hee , Kang Hee-Chul , Park Eun-Jeon , Zhao Yu-Zhe , Kim Youn-Chul , Sohn Dong Hwan
Published: May 2003

Hepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis. In this study, we investigate the inhibitory effect of butein on the activation and proliferation of rat primary cultured hepatic stellate cells. Possible cytotoxic effects were measured on stellate cells and hepatocytes using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The effects of butein on the production of collagen and smooth muscle α-actin proteins were examined at the same concentration, by western blot. The effects of butein on α1(I) collagen, tissue inhibitor of metalloproteinase-1, and metalloproteinase-13 gene expression in activated stellate cells were investigated by measuring mRNA levels using reverse transcription polymerase chain reaction. The effect of butein on DNA synthesis was also determined. Butein, at a concentration of 1 μg mL−1, reduced DNA synthesis without affecting cell viability, and downregulated smooth muscle α-actin and type-I collagen expression, and α1(I) collagen and tissue inhibitor of metalloproteinase-1 mRNA expression, while treatment with butein induced metalloproteinase-13 mRNA expression. These findings suggest that butein is a potent inhibitor of stellate cell transformation.
Investigation on the antiplatelet activity of pyrrolo[3,2-c]pyridine-containing compounds
Authors: Voskressensky Leonid G , de Candia Modesto , Carotti Andrea , Borisova Tatiana N , Kulikova Larisa N , Varlamov Alexey V , Altomare Cosimo
Published: May 2003

A series of 4,5,6,7-tetrahydro-1H-pyrrolo[3,2-c]pyridines (THPPs), mostly C(2)-substituted derivatives, and some 2, 3, 4, 5-tetrahydro-1H-pyrido[4, 3-b]indoles (THPIs) were synthesized and tested in-vitro for their ability to inhibit aggregation of human platelet-rich plasma (PRP) induced by adenosine 5′-diphosphate (ADP) and adrenaline (epinephrine). 5-Benzyl THPP (3), 2-(benzylamino)methyl THPP (5f) and 2-ethyl THPI (6) moderately and dose-dependently inhibited platelet aggregation induced by adrenaline and, to a lesser extent, by ADP. These compounds inhibited the second phase of the PRP aggregation triggered by adrenaline, which largely depends upon thromboxane A2 production and ADP release. In the adrenaline-stimulated aggregation, the THPI derivative 6 was found to be nearly equipotent with aspirin, their IC50 values (concentration effecting 50% inhibition of aggregation) being 90 and 60 μM, respectively. A relation between activity and calculated octanol-water partition coefficient suggested that a log P value around 2.5 should be the optimal lipophilicity value for the activity of THPP-containing compounds.
The effect of protective agents on the stability of plasmid DNA by the process of spray-drying
Authors: Kuo Jung-hua Steven
Published: May 2003

The effect of several protective agents was assessed on the stability of spray-dried plasmid DNA. The spray-drying process had adverse effects on the tertiary structure of plasmid DNA with the protective agents of sucrose, glycine and agarose. With the protection of these noncondensing agents, a band corresponding to the linear form of plasmid DNA was observed in the gel electrophoresis between the supercoiled circular (SC) form and the open circular (OC) form. On the contrary, spray-dried plasmid DNA maintained some degree of structural integrity under the protection of condensing agents. For the protection by neutral condensing polymers, such as polyethylene glycol 1000 and 4000, no linear form between the SC form and the OC form of plasmid DNA was revealed in the gel electrophoresis. Also, excess cationic condensing polymer, polyethyleneimine, had the ability to provide the plasmid DNA with protection from degradation as indicated by the preservation in SC and OC forms of plasmid DNA on the agarose gel electrophoresis. Moreover, DNA topology was unchanged after six-month storage at 4°C by the protection of these neutral and cationic condensing agents. Accordingly, DNA condensation induced by condensing agents may provide a way to minimize damage to plasmid DNA by the process of spray drying.
Changes of materials that scavenge 1, 1-diphenyl-2-picrylhydrazyl radicals in plasma by per-oral administration of Kampo medicine, Ninjin-yoei-to in rats
Authors: Egashira Toru , Takayama Fusako , Komatsu Yasuhiro
Published: May 2003

The Kampo medicine, Ninjin-yoei-to, scavenged 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent fashion as did ascorbic acid and α-tocopherol. Ninjin-yoei-to, which is composed of 12 herbs, had a potent DPPH radical scavenging ability. We investigated the transition of the materials that scavenge DPPH radicals in plasma after oral administration of Ninjin-yoei-to to rats. When 1.0 g kg−1 Ninjin-yoei-to was administered, the DPPH radical scavenging ability increased at 30 min and biphasic peaks were observed at 2 h and at 10h. From the response-time profile, kinetic parameters including values for Ka (absorption rate constant), tmax (peak concentration time), t1/2 (half-life) and MRT (mean residence time) of the radical scavenging ability in plasma could be calculated for DPPH radicals. Ka values were 0.53 ± 0.03 and 0.36 ± 0.07 h, tmax values were 2.1 ± 1.04 and 8.56 ± 2.69 h, t1/2 values were 1.60 ± 0.12 and 3.39 ± 1.72 h, and MRT values were 4.14 ± 1.59 and 8.18 ± 2.55 h, respectively. These parameters calculated from the antioxidation dynamics were considered to offer a very meaningful procedure for examining the effects of Ninjin-yoei-to.
Pleiotropic effect due to targeted depletion of secretory rhoptry protein ROP2 inToxoplasma gondii
Authors: Nakaar Valerian , Ngô Huân M. , Aaronson Emily P. , Coppens Isabelle , Stedman Timothy T. , Joiner Keith A.
Published: May 2003

Long after their discovery, the function and biogenesis of rhoptries remain enigmatic. In Apicomplexan parasites, these organelles discharge and their contents are exocytosed at the time of host cell invasion, and are thus proposed to play an essential role in establishing the parasitophorous vacuole. In Toxoplasma gondii, ROP2 is suspected to serve as the molecular link between host cell mitochondria and parasitophorous vacuole membrane. In this study we addressed the function of ROP2. Targeted depletion of ROP2 using a ribozyme-modified antisense RNA strategy resulted in multiple effects on parasite morphology because of a disruption in the formation of mature rhoptries, and an arrest in cytokinesis. The association of host cell mitochondria with the parasitophorous vacuole membrane was abolished and the ROP2-deficient parasites had a reduced uptake of sterol from the host cell. Furthermore, these parasites invaded human fibroblasts poorly and had markedly attenuated virulence in mice. We conclude that rhoptry discharge, and in particular release of ROP2, are essential for parasite invasion, replication and host cell-parasite interaction.
Kinesin II and regulated intraflagellar transport ofChlamydomonasaurora protein kinase
Authors: Pan Junmin , Snell William J.
Published: May 2003

The assembly and functioning of cilia and flagella depend on a complex system of traffic between the organelles and the cell body. Two types of transport into these organelles have been identified. The best characterized is constitutive: in a process termed intraflagellar transport (IFT), flagellar structural components are continuously carried into cilia and flagella on transport complexes termed IFT particles via the microtubule motor protein kinesin II. Previous studies have shown that the flagella of the unicellular green alga Chlamydomonas exhibit a second type of protein import that is regulated. During fertilization, the Chlamydomonas aurora protein kinase CALK undergoes regulated translocation from the cell body into the flagella. The motor that powers this second, regulated type of movement is unknown. Here, we have examined the cellular properties of the CALK in Chlamydomonas and used a kinesin II mutant to test the idea that the motor protein is essential for regulated translocation of proteins into flagella. We found that the CALK that is transported into flagella of wild-type gametes becomes part of a membrane-associated complex, that kinesin II is essential for the normal localization of this Chlamydomonasaurora protein kinase in unactivated gametes and that the cAMP-induced translocation of the protein kinase into flagella is disrupted in the fla10 mutants. Our results indicate that, in addition to its role in the constitutive transport of IFT particles and their cargo, kinesin II is essential for regulated translocation of proteins into flagella.
Differential requirements of novel A1PiZ degradation deficient (ADD)genes in ER-associated protein degradation
Authors: Palmer Elizabeth A. , Kruse Kristina B. , Fewell Sheara W. , Buchanan Sean M. , Brodsky Jeffrey L. , McCracken Ardythe A.
Published: May 2003

In the eukaryotic cell, a protein quality control process termed endoplasmic reticulum-associated degradation (ERAD) rids the ER of aberrant proteins and unassembled components of protein complexes that fail to reach a transport-competent state. To identify novel genes required for ERAD, we devised a rapid immunoassay to screen yeast lacking uncharacterized open reading frames that were known targets of the unfolded protein response (UPR),a cellular response that is induced when aberrant proteins accumulate in the ER. Six genes required for the efficient degradation of the Z variant of theα1-proteinase inhibitor (A1PiZ), a known substrate for ERAD, were identified, and analysis of other ERAD substrates in the six A1PiZ-degradation-deficient (add) mutants suggested diverse requirements for the Add proteins in ERAD. Finally, we report on bioinformatic analyses of the new Add proteins, which will lead to testable models to elucidate their activities.
Requirement for Pax6 in corneal morphogenesis: a role in adhesion
Authors: Davis Janine , Duncan Melinda K. , Robison W. Gerald , Piatigorsky Joram
Published: May 2003

The Pax6 transcription factor functions early during embryogenesis to control key steps in brain, pancreas, olfactory and ocular system development. A requirement for Pax6 in proper formation of lens, iris and retina is well documented. By examining the corneas of heterozygous Small eye (SEY) mice,this report shows that Pax6 is also necessary for normal corneal morphogenesis. In particular, the epithelial component of the postnatal and adult SEY (+/–) cornea is thinner owing to a reduction in the number of cell layers, despite a tenfold increase in the proliferative index and no change in TUNEL labeling. Ultrastructural views revealed large gaps between corneal epithelial cells and a change in the appearance of desmosomes,suggesting that adhesion abnormalities contribute to the corneal phenotype of SEY (+/–) mice. Western blot analysis and immunofluorescence showed equivalent amounts and normal localization of E-cadherin in SEY (+/–)corneas, and the actin cytoskeleton appeared normal as judged by phalloidin staining. By contrast, the levels of desmoglein, β-catenin andγ-catenin were reduced in the SEY (+/–) cornea. In addition, the amount of keratin-12 mRNA and protein, the major intermediate filament, was reduced in SEY (+/–) corneal epithelium as shown by in situ hybridization and immunohistochemistry. Finally, the SEY (+/–) corneal epithelium adheres less well than wild-type when challenged with gentle rubbing using a microsponge. In conclusion, our results indicate that cellular adhesion is compromised in the SEY (+/–) corneal epithelium and suggests a role for Pax6 in the proper generation and maintenance of the adult cornea.
Genes coding for intermediate filament proteins: common features and unexpected differences in the genomes of humans and the teleost fishFugu rubripes
Authors: Zimek Alexander , Stick Reimer , Weber Klaus
Published: May 2003

We screened the genomic sequences of the teleost fish Fugu rubripes for genes that encode cytoplasmic intermediate filament (IF)proteins. Here, we compare the number of genes per subfamily (I to IV) as well as the gene mapping in the human and fish genomes. There are several unexpected differences. F. rubripes has a sizeable excess of keratin type I genes over keratin type II genes. Four of the six keratin type II genes map close to four keratin type I genes. Thus, a single keratin II gene cluster(as in mammals) seems excluded. Although a continuous genome sequence is not yet available for F. rubripes, it is difficult to see how all 19 keratin type I genes can be collected as in the human genome into a single cluster without the presence of type II genes and various unrelated genes. F. rubripes has more type III and type IV genes than humans. Some of the type IV genes acquired additional novel intron positions. One gene even harbors (in addition to the two type IV introns) three novel introns and three introns usually present only in mammalian and F. rubripes type I-III genes. This mixture of type IV and type I-III intron positions poses a problem for the traditional view that the first type IV gene arose in evolution by a mRNA-mediated translocation event. In the 42 F. rubripes genes analysed here, there are several differences in intron patterns compared with mammalian genes. Most correspond to additional introns in the fish genes. A search for genes encoding nuclear lamins reveals the four established fish lamins (A, B1, B2 and LIII) as well as an unexpected second lamin A.
Disturbed Ca2+ kinetics in N-deacetylase/N-sulfotransferase-1 defective myotubes
Authors: Jenniskens Guido J. , Ringvall Maria , Koopman Werner J. H. , Ledin Johan , Kjellén Lena , Willems Peter H. G. M. , Forsberg Erik , Veerkamp Jacques H. , van Kuppevelt Toin H.
Published: May 2003

The biosynthesis of heparan sulfate, present on the cell surface and in the basal lamina surrounding cells, is a multistep process in which each step is mediated by a specific enzyme. The initial modification of the precursor polysaccharide, N-deacetylation followed by N-sulfation of selected N-acetyl-D-glucosamine residues, is catalyzed by the enzyme glucosaminyl N-deacetylase/N-sulfotransferase (NDST). This event is a key step that regulates the overall sulfate content of the polysaccharide. Here, we report on the effects of NDST deficiency on Ca2+ kinetics in myotubes from NDST-1- and NDST-2-deficient mice,indicating a novel role for heparan sulfate in skeletal muscle physiology.

Immunostaining for specific heparan sulfate epitopes showed major changes in the heparan sulfate composition in skeletal muscle tissue derived from NDST-1–/– mice and NDST–/–cultured myotubes. Biochemical analysis indicates a relative decrease in both N-sulfation and 2-O-sulfation of skeletal muscle heparan sulfate. The core protein of heparan sulfate proteoglycan perlecan was not affected, as judged by immunohistochemistry. Also, acetylcholine receptor clustering and the occurrence of other ion channels involved in excitation-contraction coupling were not altered. In NDST-2–/– mice and heterozygous mice no changes in heparan sulfate composition were observed. Using high-speed UV confocal laser scanning microscopy, aberrant Ca2+ kinetics were observed in NDST-1–/– myotubes, but not in NDST-2–/– or heterozygous myotubes. Electrically induced Ca2+ spikes had significantly lower amplitudes, and a reduced removal rate of cytosolic Ca2+, indicating the importance of heparan sulfate in muscle Ca2+ kinetics.
Drosophila skpA, a component of SCF ubiquitin ligases, regulates centrosome duplication independently of cyclin E accumulation
Authors: Murphy Terence D.
Published: May 2003

Centrosome duplication must be coupled to the main cell cycle to ensure that each cell has precisely two centrosomes at the onset of mitosis. Supernumerary centrosomes are commonly observed in cancer cells, and may contribute to tumorigenesis. Drosophila skpA, a component of SCF ubiquitin ligases, regulates the link between the cell and centrosome cycles. Lethal skpA null mutants exhibit dramatic centrosome overduplication and additional defects in chromatin condensation, cell cycle progression and endoreduplication. Surprisingly, many mutant cells are able to organize pseudo-bipolar spindles and execute a normal anaphase in the presence of extra functional centrosomes. SkpA mutant cells accumulate higher levels of cyclin E than wildtype cells during S and G2, suggesting that elevated cdk2/cyclin E activity may account for the supernumerary centrosomes in skpA– cells. However, centrosome overduplication still occurs in skpA–;cycE– mutant animals, demonstrating that high cyclin E levels are not necessary for centrosome overduplication. These data suggest that additional SCF targets regulate the centrosome duplication pathway.
Male-like behavioral patterns and physiological alterations induced by androgenic gland implantation in female crayfish
Authors: Barki Assaf , Karplus Ilan , Khalaila Isam , Manor Rivka , Sagi Amir
Published: May 2003

The androgenic gland (AG) has been shown to regulate male sexual differentiation and secondary male characteristics in Crustacea. This study presents for the first time in crustaceans evidence for masculinization effects of the AG on reproductive behavior, in addition to morpho-anatomical and physiological effects. AG implantation into immature female red claw crayfish Cherax quadricarinatus inhibited secondary vitellogenesis and development of the ovaries, as well as morphological traits that facilitate maternal egg brooding; it also caused the appearance of secondary male characteristics. However, primary male characteristics and a masculine reproductive system were not developed. In pair encounters, aggression was substantially lower in interactions between AG-implanted and intact females than in interactions within AG-implanted or intact pairs. Moreover, elements of mating behavior, i.e. male courtship displays and false copulations, were exhibited by AG-implanted females in several encounters with intact females. In addition to known morpho-anatomical and physiological effects of the AG in crustaceans, the present study suggests that the AG has novel effects on the neural network that generates social behavior.
Unconventional ventral attachment of time–depth recorders as a new method for investigating time budget and diving behaviour of seabirds
Authors: Tremblay Yann , Cherel Yves , Oremus Marc , Tveraa Torkild , Chastel Olivier
Published: May 2003

We tested the use of commercially available electronic time–depth recorders (TDRs) to quantify activities and thus total time budgets of seabirds. This new method involved first fitting TDRs onto the birds' bellies(not on their backs), and, secondly, analysing continuous recordings of temperature, light and pressure to differentiate activities on land and at sea. The birds studied were 12 common guillemots Uria aalge rearing chicks at Hornøya, in northern Norway. The method successfully recorded five different activities: at the colony, flying, diving, and resting or active at the sea surface. Overall, common guillemots spent 68% of their time at the colony and 32% at sea. While at sea, the birds spent the majority (77%)of their time at the surface, during which they were active 64% of the time,and rested only 13%. Birds engaged in the costly behaviours of flying and diving for shorter times (11% and 12% of their time at sea, respectively). The method allowed us to differentiate between two types of trips to sea based on the presence (foraging trips: 77% of the total number of trips) or absence(non-foraging trips: 23%) of dives. On average, foraging trips lasted 3.2 h,but most trips were shorter (<1 h), during which the mean estimated travel distance from the colony was 11 km. Diving occurred in bouts of 7.7±6.6 dives (mean ± S.D.). The mean maximum dive depth was 10.2±7.6 m(deepest dive: 37 m), and the mean dive duration and post-dive intervals were 38.7±21.3 s (longest dive: 119 s) and 20±12 s, respectively. Direct and indirect evidence suggests that common guillemots had no difficulty in finding food during the study period, and that the TDRs had minimal effects on the birds' behaviour and physiology. The method is easy to use in the field and is applicable to many other flying seabird species; it is therefore an efficient way of collecting information on time budgets and diving behaviour in the context of various ecological and monitoring studies.
The role of visual landmarks in the avian familiar area map
Authors: Holland Richard A.
Published: May 2003

The question of whether homing pigeons use visual landmarks for orientation from distant, familiar sites is an unresolved issue in the field of avian navigation. Where evidence has been found, the question still remains as to whether the landmarks are used independent of the map and compass mechanism for orientation that is so important to birds. Recent research has challenged the extent to which experiments that do not directly manipulate the visual sense can be used as evidence for compass-independent orientation. However, it is proposed that extending a new technique for research on vision in homing to include manipulation of the compasses used by birds might be able to resolve this issue. The effect of the structure of the visual sense of the homing pigeon on its use of visual landmarks is also considered.
Metabolic and ionic responses of trout hepatocytes to anisosmotic exposure
Authors: Krumschnabel Gerhard , Gstir Ronald , Manzl Claudia , Prem Caroline , Pafundo Diego , Schwarzbaum Pablo J.
Published: May 2003

Trout hepatocytes exposed to hypo- or hyperosmotic conditions respond by swelling and shrinking, respectively, followed by regulatory volume changes that almost, although not completely, restore cell volume. These anisosmotic conditions have a significant impact on metabolic functions. In hyposmotic medium, oxygen consumption(V̇O2) and glucose production rates were significantly reduced, whereas lactate accumulation was not significantly affected. By contrast, hyperosmotic conditions did not affect V̇O2 and lactate production but caused a sustained reduction in glucose production. Volume changes were also accompanied by alterations in intracellular free calcium ([Ca2+]i). At the cell population level,hyposmotic exposure evoked a moderate and slowly developing increase in[Ca2+]i, whereas hyperosmolarity caused a pronounced and sustained increase, which peaked at the time of maximum cell shrinkage but clearly exceeded a mere concentration effect due to volume reduction. Responses of individual cells were highly variable in hyposmotic medium, with only 60% showing a clear increase in [Ca2+]i, while in hyperosmotic conditions all cells displayed elevated[Ca2+]i levels. A decrease in intracellular pH (pHi)observed in hyposmotic medium was insensitive to EIPA, an inhibitor of Na+/H+ exchange, and SITS, an inhibitor of Cl–/HCO3– exchange, but was prevented in Cl–-free medium. In hyperosmotic medium, pHi increased. This alkalinization did not occur under conditions of blocked Na+/H+ exchange and was significantly diminished upon inhibition of Cl–/HCO3– exchange,suggesting an important role of these ion transporters in regulatory volume increase of trout hepatocytes.
Stimulation of JH biosynthesis by the corpora allata of adult female Aedes aegypti in vitro: effect of farnesoic acid and Aedesallatotropin
Authors: Li Yiping , Unnithan Gopalan C. , Veenstra Jan A. , Feyereisen René , Noriega Fernando G.
Published: May 2003

Previous studies have demonstrated that the synthesis of juvenile hormone(JH) by the isolated corpora allata (CA) complex in vitro as well as the JH titer in the yellow fever mosquito Aedes aegypti are elevated before feeding and low after a blood meal. In the present study, we used an in vitro radiochemical assay to analyze the effect of farnesoic acid(FA) and Aedes allatotropin (Aedes-AT) on the biosynthesis of JH and methyl farnesoate (MF) by the isolated CA complex of A. aegypti adult female. CA complex from day-0 females (0–1 h after emergence) exhibited a low basal juvenile hormone III (JH III) biosynthetic activity and did not respond to either allatotropic or FA stimulation. However, incubation of CA complexes from newly emerged females with Aedes-AT plus FA resulted in very high production of JH III. This is the first report suggesting that allatotropin makes corpora allata in newly emerged females capable for JH biosynthesis. When we studied CA complexes dissected from females 1 day after emergence, the stimulatory action of Aedes-AT was strong and dose-dependent,with maximum stimulation in the range of 10–8–10–9 mol l–1,suggesting that Aedes-AT is indeed a true allatotropin (a molecule with allatotropic activity) in A. aegypti. The addition to the culture medium of 40 μmol l–1 FA, a JH precursor, resulted in a 9-fold increase in JH III biosynthesis in 2-, 4- and 6-day-old sugar-fed females. The two major labeled products synthesized by the stimulated CA complex were identified as JH III and MF by RP-HPLC and GC–MS. Treatment of CA complexes with FA, but not Aedes-AT, resulted in an increase in MF. Application of both Aedes-AT and FA to the CA complexes of 2-, 4- and 6-day-old females resulted in the same effects as FA alone. These data suggest that in sugar-fed females, FA and Aedes-AT exert different effects on the terminal steps in JH biosynthesis.
Distribution and serotonin-induced activation of vacuolar-type H+-ATPase in the salivary glands of the blowflyCalliphora vicina
Authors: Zimmermann Bernhard , Dames Petra , Walz Bernd , Baumann Otto
Published: May 2003

Secretory activity in blowfly salivary glands is activated by the hormone serotonin. We have investigated the distribution and activity of two cation pumps that are possibly involved with transepithelial ion transport, i.e. Na+/K+-ATPase and vacuolar-type H+-ATPase(V-ATPase). By immunofluorescence labelling of secretory cells,Na+/K+-ATPase was localized on the basolateral plasma membrane and V-ATPase on the highly folded apical membrane. Activities of both ATPases were probed in salivary gland homogenates by applying specific inhibitors for these ion pumps, namely ouabain and bafilomycin A1. In control glands, bafilomycin-A1-sensitive V-ATPase activity and ouabain-sensitive Na+/K+-ATPase activity accounted for 36% and 19%, respectively, of the total ATPase activity. V-ATPase activity increased approximately twofold after stimulation with serotonin, whereas Na+/K+-ATPase activity was not significantly affected. Biochemical assays provided evidence that the serotonin-induced activation of V-ATPase activity was accompanied by a recruitment of peripheral V1subunits from the cytosol to the plasma membrane, indicative of the assembly of V0V1 holoenzymes.

These data show that a V-ATPase located in the apical plasma membranes of the secretory cells is a component of the apical `potassium pump' that has been identified previously by physiological approaches. The V-ATPase energizes the apical membrane and provides the primary driving force for fuelling a putative K+/nH+ antiporter and, thus, for fluid secretion. Serotonin-induced assembly of V0V1holoenzymes might constitute a regulatory mechanism for the control of pump activity.
A [3+2]-Photocycloaddition of 9,10-Dicyanophenanthrene to 1,3-Butadiene
Authors: Kubo Yasuo , Kusumoto Kouhei , Nakajima Satoshi , Inamura Isamu
Published: May 2003

In the photoreactions of 9,10-dicyanophenanthrene (6) with 1,3-butadiene (7) a novel [3+2]-photocycloaddition at the 9,10-position of the phenanthrene ring of 6 to one of the double bond of 7 and a [2+2]-cycloaddition at the 9,10-position of 6 were found to proceed from the singlet and the triplet excited states of 6, respectively.
Monitoring of Hydrothermal Reactions in 3 ms Using Fused-Silica Capillary Tubing
Authors: Kawamura Kunio
Published: May 2003

Monitoring of hydrothermal reactions in the time range of 3 - 1000 ms was succeeded by flow reactor using fused-silica capillary tubing. The technique was applied for measuring the hydrolysis rate of ATP at 250 °C in which the minimum monitoring time was 3.1 ms. The rate constants of ATP hydrolysis was consistent with that was extrapolated of the Arrhenius plots in our previous study. This method enables milli-second monitoring of hydrothermal reactions.
Construction of a Multiple Porphyrin System Using a de novo Designed Peptide Porphyrin and Hemin
Authors: Ushiyama Masato , Arisaka Fumio , Yamamura Takeshi
Published: May 2003

Multiple porphyrin systems were constructed using a Zn(II) porphyrin, A, which is a de novo designed peptide porphyrin, and Fe(III) protoporphyrin IX chloride, B. A forms a dimer in buffer solution containing 2,2,2-trifluoroethanol. However, A forms a trimer by incorporating three equivalents of B per A. The results suggest that the A/B solution achieves a 12-porphyrin system consisting of different kinds of metalloporphyrins.
Unusual Oxidation Reaction of an Overcrowded Thiagermacyclohexene Derivative
Authors: Tokitoh Norihiro , El-Sayed Ibrahim El-Tantawy , Okazaki Renji
Published: May 2003

Oxidation of extremely overcrowded 1,2-thiagermacyclohex-4-ene derivatives with m-chloroperbenzoic acid resulted in competitive formation of the ring expanded 1,2,7-oxathiagermacyclohept-4-ene derivatives and the ring contracted 1,2,3-oxathiagermacyclopentane derivatives. The latter reaction products are found to isomerize into the former ones very slowly at room temperature not only in solution but also in the crystalline state.
The Formation of a Hydrogencarbonato-bridged Dinuclear Copper(II) Complex by Fixation and Activation of Atmospheric CO2
Authors: Nishida Yasuko , Yatani Akihiro , Nakao Yasuo , Taka Jyun-ichiro , Kashino Setsuo , Mori Wasuke , Suzuki Shinnichiro
Published: May 2003

The first hydrogencarbonato-bridged dinuclear copper(II) complex [Cu2(L)(HCO3)](BF4)2·5H2O, 1 was obtained by allowing of acetone solution containing a copper(II) complex [Cu2(L)(OH)](BF4)2·6H2O, where HL is N,N,N′,N′-tetrakis[(1-methyl-2-benzimidazolyl)methyl]-2-hydroxy-1,3-diaminopropane. The crystal structure of 1 was determined by X-ray crystallography and characterized by the magnetic susceptibility and infrared and visible absorption spectrum.
Synthetic Study of Zoanthamine Alkaloids: The C-ring Model Possessing Three Consecutive Quaternary Carbons
Authors: Hirai Go , Oguri Hiroki , Hirama Masahiro
Published: May 2003

Stereo-controlled construction of the C-ring model (4) of zoanthamine alkaloids was achieved via a SmI2-mediated Simmons-Smith reaction.
Inhibition of 2,7-Dideoxy-7-fluoro-2,3-didehydrosialic Acid for Binding of Influenza Virus H1 Hemagglutinin to GM3
Authors: Sate Toshinori , Ohtake Fuyuka , Ohira Yutaka , Okahata Yoshio
Published: May 2003

A sialidase inhibitor, 2,7-dideoxy-7-fluoro-2,3-didehydrosialic acid was found to effectively inhibit the binding of influenza virus H1 hemagglutinin to ganglioside GM3.
Hydrogen Evolution from Glucose with the Combination of Glucose Dehydrogenase and Hydrogenase from A. eutrophus H16
Authors: Inoue Tomoyuki , Kumar Shrestha Niranjan , Kamachi Toshiaki , Okura Ichiro
Published: May 2003

Hydrogen production system from glucose consisting of glucose dehydrogenase from Bacillus sp. and hydrogenase from Alcaligenes eutrophus H16 was established. When the solution containing glucose, glucose dehydrogenase, NAD, and hydrogenase was incubated at 30 °C, hydrogen evolution was observed.
First Observation That Electroinactively Bound Cations in Clay Can Participate in Electrocatalytic Reaction
Authors: Ilangovan G , Zen J-M
Published: May 2003

The electrocatalytic oxidation of guanine by nontronite-bound electroinactive Fe(bpy)32+ has been identified with a catalytic rate constant of 5.84 × 104 M s−1.
Reductive Degradation of a [2Fe-2S] Cluster of Chlorella Ferredoxin Studied by Circular Dichroism Spectroscopy
Authors: Nishiyama Katsuhiko , Yamashita Ryu , Ishida Makoto , Taniguchi Isao
Published: May 2003

Chlorella ferredoxin is thermostable for several hours at 50 °C. However, in the presence of 9,10-phenanthrorine or 2,2′-bipyridine, the oxidized [2Fe-2S] cluster of ferredoxin undergoes spontaneous reduction to the reduced state without adding other reducing agents.
Synthesis and Spectral Properties of Novel Si-Ru-Ru-Si-C6H4 Polymers
Authors: Nombel Paul , Hatanaka Yasuo , Shimada Shigeru , Tanaka Masato
Published: May 2003

Dehydrogenative coupling reactions of bis(hydrosilyl)benzenes with [Ru3(CO)12] afford moderate yields of the polymers [-SiRR′-Ru(CO)4-Ru(CO)4-SiRR′-C6H4-]n which exhibit large solvent-dependent change of the UV-VIS spectra. The absorption maximum of the polymer is markedly red-shifted, compared with monomeric complex [PhMe2SiRu(CO)4Ru(CO)4SiMe2Ph].
High-Spin Oxyphenylbenzo-Annelated Dehydro[12]annulene
Authors: Pu Yong-Jin , Takahashi Masahiro , Tsuchida Eishun , Nishide Hiroyuki
Published: May 2003

A ground state quartet molecule, 2,8,14-trisoxyphenyltribenzotrisdehydro[12]annulene, was synthesized; the dehydroannulene acted as an effective ferromagnetic coupler for the pendant spins.
Conformational and Intramolecular Hydrogen-Bonding Properties of Substituted Dithia[3.3]metacyclophanes
Authors: Moriguchi Tetsuji , Sakata Kazunori , Tsuge Akihiko
Published: May 2003

Conformational properties and intramolecular hydrogen-bondings of dithia[3.3]metacyclophanes carrying one or two amino group on their internal positions were studied by 1H-NMR, IR spectra and X-ray structural analyses. It was found out that intramolecular hydrogen-bonding network between amino protons and bridge sulfur atoms is formed and it is closely related to the conformations of cyclophanes.
One-way cis to trans Photoisomerization in Styrylnaphthalene Derivative: Role of Substituents and Solvent
Authors: Bushan K Mani , Ayodele E Temidayo , Gopal V Raj , Soujanya T , Rao V Jayathirtha
Published: May 2003

One-way cis to trans photoisomerization is achieved in styrylnaphthalene derivative (3) by suppressing the trans to cis isomerization with the use of suitable substituents and solvents.
Photoreactions of N-Methyl-1,8-naphthalimide with Methylbenzenes: [3+3]-Additions and Water-Incorporated Additions
Authors: Kubo Yasuo , Fuseya Nobuhiro , Nakajima Satoshi
Published: May 2003

Novel [3+3]-additions and water (methanol)-incorporated additions were observed in the photoreactions of N-methyl-1,8-naphthalimide with methylbenzenes, such as xylenes, mesitylene, and durene, in acetonitrile. A mechanism for the reactions is proposed on the basis of the fluorescence quenching examinations, calculations of ΔG associated with the electron transfer, and deuteration studies.
Regiocontrol of Diels-Alder Reaction of Conjugate 1-Trienol Ether in Chiral Tropilidene with TCNE
Authors: Sugimura Takashi , Nagano Shinya , Kohno Harumi , Fujita Morifumi , Tai Akira
Published: May 2003

The Diels-Alder reaction of tetracyanoethylene (TCNE) with a 1-trienol unit in the tropilidenes at the 1,4-position was a quick and reversible process, whereas the 3,6-addition only proceeded in polar solvent and was irreversible.
The Most Effective Packing of Layers: Synthesis and Structure of [Ni(4,4′-bipyridine)2(NCS)2]n
Authors: Zhang Yugen , Jianmin Li , Wei Deng , Nishiura Masayoshi , Imamoto Tsuneo
Published: May 2003

The complex [Ni(4,4′-bipyridine)2(NCS)2]n, in which nickel atoms are linked by two different Ni-4,4′-bpy-Ni assemblies to form two-dimensional distorted square net structure and the most effective packing of layers, has been isolated and structurally characterized.
A New Approach to Organic/Inorganic Composites. Thin Film Coating of CaCO3 on a Chitin Fiber in the Presence of Acid-Rich Macromolecules
Authors: Kato Takashi , Amamiya Takahiro
Published: May 2003

Thin film coating of CaCO3 crystals on a chitin fiber from CaCO3 solution in the presence of an acid-rich macromolecule leads to the fabrication of a novel type of organic/inorganic composites. Molecular interactions between functional groups of these organic matrices play a key role for this control of inorganic crystallization.