bluuebunny/crossref_metadata_2025 huggingface dataset:
The pathway of CO binding to cytochrome c oxidase Can the gateway be closed?
Authors: Hill Bruce C.
Published: July 2002

Addition of cyanide to the CO complex of cytochrome oxidase reduces the apparent photosensitivity of the Fe–CO bond. This effect is not seen with azide, or when cyanide is added to ferromyoglobin‐CO. It is proposed that cyanide binds to CuB, and restricts the passage of CO out of the protein. This restriction favors geminate recombination of CO and ferrocytochrome a
3, thereby lowering the apparent quantum yield for CO photolysis. The apparent K
d of cyanide for CuB is 15.4 mM. These data support a direct role for CuB in ligand binding by cytochrome c oxidase.
Determination of the molecular mass of the native β‐cell sulfonylurea receptor
Authors: Skeer Jacqueline M. , Dégano Pilar , Coles Barbara , Potier Michel , Ashcroft Frances M. , Ashcroft Stephen J.H.
Published: July 2002

In the present study we have determined the molecular mass of the β‐cell sulfonylurea receptor in its native form by two different experimental approaches; gel filtration chromatography and radiation inactivation analysis. We first confirmed that the denatured photolabelled MIN6 β‐cell receptor had a molecular size of 141 ± 2 kDa (mean ± S.E., n = 8). Under non‐denaturing conditions, using gel filtration chromatography, apparent molecular masses of 166 ± 1 kDa (mean ± S.E., n = 3) and 182 ± 5 kDa (mean ± S.E., n = 4) were determined for the photoaffinity‐labelled and unlabelled sulfonylurea receptor, respectively. We conclude that in the solubilized state the receptor exists as a monomer. Radiation inactivation analysis indicated that the receptor has a target size of 250 ± 30 kDa (mean ± S.E., n = 7). This value for the molecular mass is larger than that obtained from SDS‐PAGE following photolabelling of the receptor (141 kDa) suggesting that the β‐cell sulfonylurea receptor is composed of more than one subunit in the native membrane.
The chaperone connection to the origins of the eukaryotic organelles
Authors: Viale Alejandro M. , Arakaki Adrián K.
Published: July 2002

The heat‐shock 60 proteins (Hsp60) constitute a subset of molecular chaperones essential for the survival of the cell, present in eubacteria as well as in eukaryotic organelles. Here, we have employed these highly conserved proteins for the inferences of the origins of the organelles. Hsp60s present in mitochondria from different eukaryotic lineages formed a clade, which showed the closest relationship to that of the Ehrlichia/Rickettsia cluster among the α‐Proteobacteria. This, in addition to phenotypic characteristics, suggests that these obligate intracellular parasites and the lineage that generated the mitochondrion shared last common ancestry. In turn, Hsp60s present in chloroplasts from plants and a red alga, respectively, clustered specifically with those of the cyanobacteria, suggesting that all plastids derive exclusively from this eubacterial lineage.
Proteolysis of thrombospondin during cathepsin‐G‐induced platelet aggregation: functional role of the 165‐kDa carboxy‐terminal fragment
Authors: Rabhi-Sabile Samia , Pidard Dominique , Lawler Jack , Renesto Patricia , Chignard Michel , Legrand Chantal
Published: July 2002

The serine‐proteinase cathepsin G (CG) is a potent agonist of platelet aggregation inducing the release and surface expression of α‐granule adhesive proteins such as fibrinogen (Fg) and thrombospondin‐1 (TSP‐1). Because Fg and TSP‐1 are potential substrates for the enzymatic activity of CG, we investigated the fate of these proteins during CG‐induced platelet aggregation using an immunoblot technique. Only a small proportion of secreted Fg was proteolyzed by CG and platelet aggregation was efficiently inhibited by anti‐fibrinogen Fab fragments. In contrast, TSP‐1 was extensively proteolyzed on aggregated platelets releasing in the milieu a fragment with M
r ≈ 28 000, corresponding to the amino‐terminal heparin‐binding domain (HBD). Several antibodies, directed against the cell‐associated carboxy‐terminal TSP‐1f fragment (M
r ≈ 165 000) impaired the formation of stable macroaggregates, indicating that this fragment may contribute to platelet aggregation in the absence of the HBD.
Antigen binding of antiganglioside antibodies in vitro is strongly influenced by the ganglioside composition of the sample
Authors: Hildebrandt Herbert
Published: July 2002

The ability of antiganglioside antibodies to detect their respective antigens in various environments was studied. In contrast to sensitive detection of pure ganglioside standards by ELISA, antibody binding to mixtures of gangliosides was drastically reduced. This loss of sensitivity also occurred with immunostaining of gangliosides absorbed to silica gel. Moreover, absorption of antibodies to antigen‐containing lipid vesicles failed, if the vesicles were prepared together with other gangliosides. These data indicate that antigen accessibility is strongly influenced by surrounding gangliosides. This should be considered whenever gangliosides are traced by antibodies. The ELISA procedure appears useful to test for such properties.
Strong control on the transit time in metabolic channelling
Authors: Kholodenko Boris N. , Sakamoto Naoto , Puigjaner Joaquim , Westerhoff Hans V. , Cascante Marta
Published: July 2002

A suite of different characteristic times is used to describe the temporal behavior of a metabolic pathway. Here we focus on the ‘transit’ time that is the average time it takes for a molecule entering the steady‐state pathway as a substrate to exit the pathway as a product. We show that metabolic channelling results in dramatic changes in control exerted by pathway enzymes on the transit time. In an ‘ideal’ pathway a doubling of the enzyme concentrations halves the transit time. In a dynamic channel such an increase can reduce the transit time by a factor of four or more.
Ureaplasma urealyticum cervical colonization as a marker for pregnancy complications
Authors: Horowitz S. , Horowitz J. , Mazor M. , Porath A. , Glezerman M.
Published: July 2002

Objectives: To determine the clinical significance of cervical colonization with (Ureaplasma urealyticum (Uu) and its possible relationship to pregnancy outcome. Methods: Cervical cultures for Uu and serum antibodies to Uu were determined in four groups of pregnant women: (1) 117 women who underwent mid‐trimester amniocentesis; (2) 47 women with preterm labor and intact membranes; (3) 34 women with preterm premature rupture of membranes; and (4) a control group of 315 healthy women with normal pregnancies. Statistical methods used were the chi‐square and Fisher's exact tests. Results: A significant increase in the cervical colonization rate with Uu was detected in all study groups (62%, 77% and 74%, respectively) when compared with the control group (42%). Women at mid‐trimester of pregnancy with a positive cervical culture and high levels of antibodies, had a higher rate of pregnancy complications than those with a negative culture and absence of antibodies (62 vs. 28%, respectively; P = 0.0006). Conclusion: Cervical colonization with Uu when associated with elevated titers of antibodies to Uu, may serve as a marker for the identification of a subpopulation of women who are at high risk for the development of pregnancy complications.
Criteria for the diagnosis of diffuse uterine myohypertrophy
Authors: Traiman P. , Saldiva P. , Haiashi A. , Franco M.
Published: July 2002

Objectives: Diffuse uterine myohypertrophy (DUMH) is a condition clinically diagnosed by the presence of uterine bleeding, homogeneous and diffuse uterine enlargement, and absence of any myoendometrial cause of bleeding. Since the morphologic criteria for the diagnosis of this entity are still controversial, this study aimed to investigate the clinical presentation and the morphologic findings of the cases of DUMH presenting at the University Hospital of Botucatu, São Paulo, Brazil. Methods: We retrospectively studied 43 consecutive patients with DUMH submitted to hysterectomy (test group) and compared the findings with those obtained from 28 patients submitted to hysterectomy due to a prolapsed uterus (control group). There were no significant differences in age, weight or height between the two groups. Results: The uterine weight of the DUMH group (mean ± S.D. 157.4 ± 46.4 g) was significantly heavier than that of the control group (99.5 ± 35.4 g) and myometrial thickness was significantly greater in the DUMH group (2.5 ± 0.5 cm) than in the control group (1.9 ± 0.4 cm). No positive correlation was observed between increased uterine weight and parity, but there was a positive correlation between uterine weight and myometrial thickness. On the basis of the present study, we suggest that the diagnosis of DUMH be made clinically and in cases of uterine weight ≥ 120 g and myometrial thickness ≥ 2.0 cm. In addition, 10 cases of each group were analyzed by morphometry to evaluate interstitial fibrosis and myometrial hypertrophy. The data showed that the increase in uterine weight in DUMH is caused by enlargement of individual myometrial fibers rather than accumulation of interstitial collagen. Conclusion: Discriminant analysis to estimate the diagnostic significance of a number of clinical and pathologic variables (age, parity, uterine weight and morphometric parameters) was able to differentiate cases of DUMH from controls in 100% of the patients.
The perspective of management of sleep disorders in Japan
Authors: Okuma T
Published: July 2002

Increases in psychosocial stress and disruption of the biological clock due to irregular sleep-wake schedules as well as an increase in the elderly population have resulted in an increase in sleep disorders, most notably insomnia. In order to manage insomnia, correction of a poor sleep environment is of primary importance. We now have many good GABA A receptor agonists such as benzodiazepines and cyclopyrrolones (zopiclone) for use as hypnotics, but to achieve improvements in nocturnal sleep and restoration of daytime functions, short- or ultra-short acting hypnotics are recommended. Zopiclone has been reported to show weaker effects on sleep architecture than other benzodiazepines and does not exacerbate mild or moderate sleep apnea syndrome. Some patients are therapeutic-dose dependent on hypnotics or anxiolytics without showing detectable side effects. It may be possible for some insomniacs, particularly forelderly people, to use the minimum necessary dose of hypnotics to achieve good sleep and live a happy life from the standpoint of good quality of life.
Lack of specificity of the traditional criteria for conversion disorders
Authors: Chabrol H , Peresson G , Clanet M
Published: July 2002

Psychological and physical signs traditionally considered as indicators of conversion disorder had never been confirmed through empirical data. Nineteen of these signs were sought in 40 patients with proved neurological disorder and in 15 patients with conversion disorder. All neurological patients but one showed at least one of these signs and most presented several signs. All the signs but one were as frequent in neurological patients as in patients with conversion disorder. These signs are lacking specificity. Even when several signs are present, this finding has no diagnostic specificity.
Catalase activity of oxygenase domain of rat neuronal nitric oxide synthase. Evidence for product formation from L‐arginine
Authors: Adhikari Sanjay , Ray Soma , Gachhui Ratan
Published: July 2002

Nitric oxide synthases (NOSs) catalyze the formation of nitric oxide from L‐arginine. We purified the heme containing, tetrahydrobiopterin‐free, oxygenase domain of rat neuronal nitric oxide synthase (nNOSox) overexpressed in Escherichia coli. We found catalase activity in nNOSox. This is significant because H2O2 may also be a product of nitric oxide synthases. We found H2O2 assisted product formation from N‐hydroxy‐L‐arginine and even from L‐arginine both in the presence and in absence of tetrahydrobiopterin. We propose how heme moiety of the oxygenase domain alone is sufficient to carry out both steps of the NOS catalysis.
31P‐CP–MAS NMR studies on TPP+ bound to the ion‐coupled multidrug transport protein EmrE
Authors: Glaubitz Clemens , Gröger Adriane , Gottschalk Kay , Spooner Paul , Watts Anthony , Schuldiner Shimon , Kessler Horst
Published: July 2002

The binding of tetraphenylphosphonium (TPP+) to EmrE, a membrane‐bound, 110 residue Escherichia coli multidrug transport protein, has been observed by 31P cross‐polarisation–magic‐angle spinning nuclear magnetic resonance spectroscopy (CP–MAS NMR). EmrE has been reconstituted into dimyristoyl phosphatidylcholine bilayers. CP–MAS could selectively distinguish binding of TPP+ to EmrE in the fluid membrane. A population of bound ligand appears shifted 4 ppm to lower frequency compared to free ligand in solution, which suggests a rather direct and specific type of interaction of the ligand with the protein. This is also supported by the observed restricted motion of the bound ligand. The observation of another weakly bound substrate population arises from ligand binding to negatively charged residues in the protein loop regions.
Evidence showing that the two‐chain form of vitronectin is produced in the liver by a selective furin cleavage
Authors: Seger Dalia , Shaltiel Shmuel
Published: July 2002

The adhesive protein vitronectin (75 kDa) occurs in human blood fluid in a one‐chain (Vn75) or a two‐chain form (Vn65+10), and is produced by a specific cleavage (at Arg379–Ala380), by a proteinase not identified hitherto. These two forms were shown to be functionally different and therefore, this cleavage may have a regulatory significance in vivo. Here, we report the use of a tailored one‐chain recombinant Vn, a specific protein kinase A phosphorylation at Ser378, and sequence analysis to show: (1) that none of the proteinases originating from blood, previously thought to be the endogenous proteinase (plasmin, thrombin, tPA, and uPA), is indeed the in vivo convertase; and (2) that furin, a serine endoproteinase residing in the secretory pathway of hepatocytes, where Vn is synthesized, specifically cleaves Vn at the endogenous cleavage site. Consequently, we propose that the Vn75 to Vn65+10 conversion takes place in the liver (not in blood) and is carried out by furin.
Functional involvement of a deoxy‐D‐xylulose 5‐phosphate reductoisomerase gene harboring locus of Synechococcus leopoliensis in isoprenoid biosynthesis
Authors: Miller Barbara , Heuser Thomas , Zimmer Wolfgang
Published: July 2002

The present work aimed to proof the functionality of the non‐mevalonate pathway in cyanobacteria. It was intended to isolate the 1‐deoxy‐D‐xylulose 5‐phosphate (DXP) reductoisomerase gene (dxr), as this gene encodes the enzyme which catalyzes a pathway‐specific, indicative step of this pathway. For this purpose, a segment of dxr was amplified from Synechococcus leopoliensis SAUG 1402‐1 DNA via PCR using oligonucleotides for conserved regions. Subsequent hybridization screening of a genomic cosmid library of S. leopoliensis with the PCR segment led to the identification of a 26.5 kbp locus on which a dxr homologous gene and two adjacent open reading frames organized in one operon were localized by DNA sequencing. The functionality of the gene was demonstrated expressing the gene in Escherichia coli and using the purified gene product in a photometrical NADPH dependent test based on the substrate DXP generating system. While the content of one of the central intermediates of the isoprenoid biosynthesis (dimethylallyl diphosphate=DMADP) was significantly (P≤0.001) increased in E. coli cells overexpressing the DXP synthase gene (dxs) of S. leopoliensis, overexpression of dxr does not lead to an elevated DMADP level. Since even in strains harboring an expression fusion of dxs the additional overexpression of dxr does not influence the DMADP content, it is concluded that Dxs but not Dxr catalyzes a rate limiting step of the non‐mevalonate isoprenoid biosynthesis.
Myeloperoxidase binds to low‐density lipoprotein: potential implications for atherosclerosis
Authors: Carr Anitra C. , Myzak Melinda C. , Stocker Roland , McCall Mark R. , Frei Balz
Published: July 2002

Myeloperoxidase (MPO), an abundant heme enzyme released by activated phagocytes, catalyzes the formation of a number of reactive species that can modify low‐density lipoprotein (LDL) to a form that converts macrophages into lipid‐laden or ‘foam’ cells, the hallmark of atherosclerotic lesions. Since MPO has been shown to bind to a number of different cell types, we investigated binding of MPO to LDL. Using the precipitation reagents phosphotungstate or isopropanol, MPO co‐precipitated with LDL, retaining its catalytic activity. The association of MPO with LDL was confirmed using native gel electrophoresis. MPO was also found to co‐precipitate with apolipoprotein B‐100‐containing lipoproteins in whole plasma. No precipitation of MPO was observed in lipoprotein‐deficient plasma, and there was a dose‐dependent increase in precipitation following addition of LDL to lipoprotein‐deficient plasma. Binding of MPO to LDL could potentially enhance site‐directed oxidation of the lipoprotein and limit scavenging of reactive oxygen species by antioxidants.
The semaphorin 3A receptor may directly regulate the activity of small GTPases
Authors: Rohm Beate , Rahim Belquis , Kleiber Bedriska , Hovatta Iiris , Püschel Andreas W.
Published: July 2002

The axon guidance signal semaphorin 3A induces the rapid collapse of growth cones by activating a receptor complex that contains neuropilin‐1 as the ligand‐binding and a plexin as the signal‐transducing subunit. Here we show that plexins bind Rho‐like GTPases and may directly regulate their activity. The cytoplasmic domain of plexins shows sequence similarity to GTPase activating proteins (GAPs) and mutation of two arginines that correspond to the catalytic residues of Ras GAPs inactivates plexin‐A1. Our data suggest that plexins may be integral membrane proteins with an intrinsic GAP activity that is essential for their ability to induce growth cone collapse.
Hepatic maturation in differentiating embryonic stem cells in vitro
Authors: Hamazaki Takashi , Iiboshi Yasuhiko , Oka Masahiro , Papst Philip J. , Meacham Amy M. , Zon Leonard I. , Terada Naohiro
Published: July 2002

We investigated the potential of mouse embryonic stem (ES) cells to differentiate into hepatocytes in vitro. Differentiating ES cells expressed endodermal‐specific genes, such as α‐fetoprotein, transthyretin, α 1‐anti‐trypsin and albumin, when cultured without additional growth factors and late differential markers of hepatic development, such as tyrosine aminotransferase (TAT) and glucose‐6‐phosphatase (G6P), when cultured in the presence of growth factors critical for late embryonic liver development. Further, induction of TAT and G6P expression was induced regardless of expression of the functional SEK1 gene, which is thought to provide a survival signal for hepatocytes during an early stage of liver morphogenesis. The data indicate that the in vitro ES differentiation system has a potential to generate mature hepatocytes. The system has also been found useful in analyzing the role of growth factors and intracellular signaling molecules in hepatic development.
The potato leafroll virus 17K movement protein is phosphorylated by a membrane‐associated protein kinase from potato with biochemical features of protein kinase C
Authors: Sokolova Marianna , Prüfer Dirk , Tacke Eckhard , Rohde Wolfgang
Published: July 2002

The 17 kDa protein (pr17), the phloem‐limited movement protein (MP) of potato leafroll luteovirus (PLRV), is associated with membranous structures and localized to plasmodesmata [Tacke et al. (1993) Virology 197, 274–282; Schmitz, J. (1995) Ph.D. Thesis, University of Cologne]. In planta the protein is predominantly present in its phosphorylated form, but it is rapidly dephosphorylated during isolation under native conditions. In an effort to examine the nature of the protein kinase(s) involved in the phosphorylation reaction, pr17 deletion mutants were expressed as fusion proteins in a bacterial expression vector system and tested for their ability to be phosphorylated by potato membrane preparations as well as by commercially available kinases. A fusion protein containing the nucleic acid‐binding, basic, C‐proximal domain (pr17C1) was identified to be phosphorylated by a Ca2+‐ and phospholipid‐dependent, membrane‐associated protein kinase. This protein kinase activity was inhibited by the addition of (19–36) protein kinase C (PKC) inhibitory peptide, known to be a highly specific inhibitor of mammalian PKC. Moreover, also the mammalian PKC from rat was able to phosphorylate pr17 in vitro. The results suggest that phosphorylation of pr17 takes place at membranous structures, possibly at the deltoid plasmodesmata connecting the sieve cell‐companion cell complex of the phloem, by the activity of PKC‐related, membrane‐associated protein kinase activity.
Induction of nuclear factor κB and activation protein 1 in postischemic myocardium
Authors: Chandrasekar Bysani , Freeman Gregory L
Published: July 2002

Ischemia/reperfusion induces nuclear factor κB (NF‐κB) and AP‐1 in rat hearts after 15 min of ischemia followed by reperfusion (R) for various periods of time (15 and 30 min, 1, 2, 3, 6, 12, and 24 h). Low levels of NF‐κB and no signal for AP‐1 were detected in shams and in non‐ischemic tissue distant from the ischemic zone. In postischemic tissue, NF‐κB levels increased biphasically with peak levels at 15 min and again at 3 h R. Immunoblotting showed minimal NF‐κB p50 subunit at all times, with changes in p65 similar to EMSA results. Northern blots showed low p50 and increased p65 expression levels at both 2 and 3 h R. By contrast, AP‐1 increased monophasically, with peak levels at 15 min R, which dropped steadily thereafter. These results indicate that NF‐κB and AP‐1 are differentially regulated during reperfusion, which may be a control mechanism for gene expression in reperfused myocardium.
Distribution of sphingosine 1‐phosphate, a bioactive sphingolipid, in rat tissues
Authors: Yatomi Yutaka , Welch Robert J. , Igarashi Yasuyuki
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Tissue specific variants of glutamate transporter GLT‐1
Authors: Utsunomiya-Tate Naoko , Endou Hitoshi , Kanai Yoshikatsu
Published: July 2002

cDNA cloning of glutamate transporter GLT‐1 from mouse brain and liver has revealed that 5′‐ends of the messages are different between brain and liver. In addition, one of the GLT‐1 cDNAs isolated from liver has been found to possess a 3′‐end different from those of the others. Reverse transcription polymerase chain reaction (RT‐PCR) amplification using primers specific for altered 5′‐ends has confirmed that brain and liver messages possess their own specific 5′‐ends. Both of the two 3′‐ends have been demonstrated by RT‐PCR to be present not only in liver but also in brain, indicating both brain and liver GLT‐1 possess two types of 3′‐ends. Although functional properties are not changed by the alteration of N‐termini and C‐termini when expressed in Xenopus laevis oocytes, co‐expression of two liver type GLT‐1 with different C‐termini (mGLT‐1A and mGLT‐1B) has been found to result in the increase in V
max of transport without changing K
m. These results suggest the tissue specific alternative splicing at 5′‐ends of GLT‐1 messages and the interesting association of spliced variants with different C‐termini.
Cloning of two novel human importin‐α subunits and analysis of the expression pattern of the importin‐α protein family
Authors: Köhler Matthias , Ansieau Stéphane , Prehn Siegfried , Leutz Achim , Haller Hermann , Hartmann Enno
Published: July 2002

The import of many proteins into the nucleus is mediated by the importin‐α/β heterodimer. While only one importin‐β gene has been found, several forms of importin‐α have been described. In addition to the three human importin‐αs already identified, we report here the primary structure of two new human importin‐α proteins. The five known human importin‐α subunits can be classified into three subfamilies that appear conserved in higher eukaryotic organisms. We show by immunoblotting that the different importin‐α subfamilies are expressed in a variety of human tissues and mammalian cell lines.
Evidence for a loop mechanism of protein transport by the thylakoid Delta pH pathway
Authors: Fincher Vivian , McCaffery Michael , Cline Kenneth
Published: July 2002

The thylakoid Delta pH pathway is a protein transport system with unprecedented characteristics. To investigate its mechanism, the topology of precursor insertion was determined. A fusion protein comprising a large polypeptide domain fused to the amino terminus of pOE17 (a Delta pH pathway precursor) was efficiently processed by thylakoid membranes. The amino terminus, including the targeting peptide, remained on the cis side of the membrane. Mature OE17 was transported to the lumen. These experiments demonstrate that Delta pH directed precursors enter the thylakoid membrane in a loop, implying that the Delta pH pathway has evolved from an export‐type protein translocation system.
Vitamin C attenuates nitrate tolerance independently of its antioxidant effect
Authors: Hinz Burkhard , Schröder Henning
Published: July 2002

In LLC‐PK1 kidney epithelial cells, a 5‐h pretreatment with glyceryl trinitrate (GTN) resulted in substantial desensitization of the intracellular cyclic GMP response to a subsequent 10‐min challenge with GTN (1 μM). GTN‐tolerant cells were fully sensitive to the spontaneous nitric oxide (NO) donor spermine NONOate, which does not require enzymatic bioactivation. Cyclic GMP stimulation by GTN was up to 3.1‐fold higher when vitamin C (1–10 mM) was present during the pretreatment period. In contrast, other oxygen radical scavengers such as tiron or dimethylsulfoxide and the NO scavenger PTIO left tolerance induction unaltered. Together, our results suggest that reactive oxygen species or NO do not contribute to the development of nitrate tolerance. Tolerance reduction by vitamin C may be due to a stabilizing effect on enzymes involved in the bioconversion of GTN to NO.
31P NMR study of the interactions between oligodeoxynucleotides containing (6‐4) photoproduct and Fab fragments of monoclonal antibodies specific for (6‐4) photoproduct
Authors: Torizawa Takuya , Kato Koichi , Kimura Yoshiko , Asada Takako , Kobayashi Hiroyuki , Komatsu Yasuo , Morioka Hiroshi , Nikaido Osamu , Ohtsuka Eiko , Shimada Ichio
Published: July 2002

A31P nuclear magnetic resonance (NMR) study of the interactions between oligonucleotides containing the (6‐4) photoproduct and the Fab fragments of monoclonal antibodies (64M3 and 64M5) recognizing the (6‐4) photoproduct is reported. The31P chemical shift data indicate that backbone conformation of (6‐4) adduct is affected by the presence of flanking oligodeoxynucleotides, and (6‐4) adducts with different backbone conformations are accommodated in the antigen binding sites of these antibodies. It was also revealed that epitopes for these antibodies consist of not only the (6‐4) adduct but the flanking di‐ or tri‐deoxynucleotides on both the 5′ and 3′ sides as well.
Galectin‐3 gene (LGALS3) expression in experimental atherosclerosis and cultured smooth muscle cells
Authors: Arar Chantal , Gaudin Jean-Charles , Capron Loı̈c , Legrand Alain
Published: July 2002

The galectin‐3 gene (LGALS3) encodes a β‐galactose binding lectin. LGALS3 expression is associated with neoplastic transformation and with differentiation of monocytes to macrophages. Factors involved in migration, proliferation, adhesion and differentiation of vascular smooth muscle cells (SMC) play a major role during atherosclerosis development. Expression of the galectin‐3 gene was not detected in quiescent SMC but was activated in aortas of hypercholesterolemic rabbits, in aortas of rats after balloon injury and in cultured SMC. These results suggest that galectin‐3 production is involved in the developmental process of atherogenesis.
tRNA‐guanine transglycosylase from Escherichia coli: recognition of full‐length ‘queuine‐cognate' tRNAs
Authors: Kung Fan-Lu , Garcia George A
Published: July 2002

A key enzyme involved in the incorporation of the modified base queuine into tRNA (position 34) is tRNA‐guanine transglycosylase (TGT). Studies of the recognition of truncated tRNAs by the Escherichia coli TGT have established a minimal recognition motif involving a minihelix with a 7 base loop containing a U‐‐U sequence (where G is replaced with queuine) [Curnow, A.W. and Garcia, G.A. (1995) J. Biol. Chem. 270, 17264–17267; Nakanishi, S. et al. (1994) J. Biol. Chem. 269, 32221–32225]. Still, a clearer understanding of the recognition of full‐length ‘queuine‐cognate' tRNAs by TGT remains lacking. In this paper, we report the in vitro transcription and enzymological characterization (K
m and k
cat) of all four ‘queuine‐cognate' tRNAs from E. coli and from Saccharomyces cerevisiae with the TGT from E. coli. No primary or secondary structures emerge as important recognition elements from this study. The modest differences in substrate specificity (relative k
cat/K
m values vary from 0.5 to 8.4) seen among these ‘queuine‐cognate' tRNAs most likely result from the accumulated effects of many subtle factors. Interestingly, the yeast tRNAs are essentially equivalent to the E. coli tRNAs as substrates for TGT, indicating that there is nothing intrinsic to the yeast tRNAs that accounts for the absence of queuine in yeast.
Clofibrate‐inducible, 28‐kDa peroxisomal integral membrane protein is encoded by PEX11
Authors: Abe Isao , Okumoto Kanji , Tamura Shigehiko , Fujiki Yukio
Published: July 2002

We cloned a human PEX11 cDNA by expressed sequence tag homology search using yeast Candida boidinii PEX11, followed by screening of human liver cDNA library. PEX11 encoded a peroxisomal protein Pex11p comprising 247 amino acids, with two transmembrane segments and a dilysine motif at the C‐terminus. Pex11p comigrated in SDS‐PAGE with a 28‐kDa peroxisomal integral membrane protein (PMP28) isolated from the liver of clofibrate‐treated rats and was crossreactive to anti‐PMP28 antibody, thereby indicating PEX11 to encode PMP28. Pex11p exposes both N‐ and C‐terminal parts to the cytosol. PEX11 was not responsible for ten complementation groups of human peroxisome deficiency disorders.
Biosynthetic processing and quaternary interactions of proprotein convertase SPC4 (PACE4)
Authors: Nagahama Masami , Taniguchi Takazumi , Hashimoto Emi , Imamaki Akiyoshi , Mori Kenji , Tsuji Akihiko , Matsuda Yoshiko
Published: July 2002

SPC4 (PACE4), a member of the eukaryotic family of subtilisin‐like proprotein convertases, is synthesized as a proenzyme (proSPC4) which undergoes proteolytic removal of N‐terminal propeptide during transit through the secretory pathway. As this propeptide processing seems to be a key event in the functional expression of SPC4, we have investigated its mechanism and the intracellular site where it occurs. In transfected fibroblast cells, the 110‐kDa proSPC4 undergoes slow cleavage to generate a 103‐kDa mature enzyme in the endoplasmic reticulum (ER). Site‐directed mutagenesis studies demonstrate that the proteolytic activation of SPC4 occurs mainly through a unimolecular autocatalytic process and propeptide cleavage is a prerequisite for its export from the ER. Sedimentation velocity and chemical cross‐linking analysis demonstrate that the precursor protein in the cells exists as both a monomer and a dimer‐sized complex whereas mature SPC4 exists only as a monomer. These results suggest that the cleavage of the N‐terminal propeptide of SPC4 plays a regulatory role in its activation and secretion through the change in its oligomeric state.
Δ9‐Tetrahydrocannabinol induces apoptosis in C6 glioma cells
Authors: Sánchez Cristina , Galve-Roperh Ismael , Canova Cecile , Brachet Philippe , Guzmán Manuel
Published: July 2002

Δ9‐Tetrahydrocannabinol (THC), the major active component of marijuana, induced apoptosis in C6.9 glioma cells, as determined by DNA fragmentation and loss of plasma membrane asymmetry. THC stimulated sphingomyelin hydrolysis in C6.9 glioma cells. THC and N‐acetylsphingosine, a cell‐permeable ceramide analog, induced apoptosis in several transformed neural cells but not in primary astrocytes or neurons. Although glioma C6.9 cells expressed the CB1 cannabinoid receptor, neither THC‐induced apoptosis nor THC‐induced sphingomyelin breakdown were prevented by SR141716, a specific antagonist of that receptor. Results thus show that THC‐induced apoptosis in glioma C6.9 cells may rely on a CB1 receptor‐independent stimulation of sphingomyelin breakdown.
Calcium‐dependent interaction of annexin I with annexin II and mapping of the interaction sites
Authors: Lee Kyoung Hoa , Na Doe Sun , Kim Jung Woo
Published: July 2002

Annexins are multifunctional intracellular proteins with Ca2+‐ and phospholipid‐binding properties. Their structures consist of four conserved repeat domains that form the core and a diverse N‐terminal tail, from which their functional differences may arise. We searched for cellular proteins that interact with the N‐terminal tail plus domain I of annexin I (ANX1) by using the yeast two‐hybrid method. Screening of a HeLa cell cDNA library yielded annexin II (ANX2) cDNA. The interaction between ANX1 and ANX2 also occurred in vitro in a Ca2+‐dependent manner. Mapping of the interaction sites revealed that interaction between domain I of ANX1 and domain IV of ANX2 was stronger than the other combinations.
Interaction of a lectin from Psathyrella velutina mushroom with N‐acetylneuraminic acid
Authors: Ueda Haruko , Kojima Kyoko , Saitoh Takeshi , Ogawa Haruko
Published: July 2002

A lectin from the fruiting body of Psathyrella velutina has been used as a specific probe for non‐reducing terminal N‐acetylglucosamine residues. We reveal in this report that P. velutina lectin recognizes a non‐reducing terminal N‐acetylneuraminic acid residue in glycoproteins and oligosaccharides. Binding of biotinyl P. velutina lectin to N‐acetylneuraminic acid residues was prevented by desialylation of glycoconjugates and was distinguished from the binding to N‐acetylglucosamine. Sialooligosaccharides were retarded or bound and eluted with N‐acetylglucosamine on a P. velutina lectin column, being differentiated from each other and also from the oligosaccharides with non‐reducing terminal N‐acetylglucosamine which bound more strongly to the column.
Endothelin‐1 induces expression of fetal genes through the interleukin‐6 family of cytokines in cardiac myocytes
Authors: Saito Shuichi , Aikawa Ryuichi , Shiojima Ichiro , Nagai Ryozo , Yazaki Yoshio , Komuro Issei
Published: July 2002

We here examined the role of the interleukin‐6 (IL‐6) family of cytokines in endothelin‐1 (ET‐1)‐induced hypertrophic responses using cultured cardiac myocytes of neonatal rats. ET‐1 induced expression of IL‐6 and leukemia inhibitory factor (LIF) genes. ET‐1‐induced LIF gene expression was abolished by inhibition of protein kinase C activity. ET‐1 activated the promoter of atrial natriuretic peptide and β‐type myosin heavy chain genes through the tyrosine kinase pathway and IL‐6 receptor gp130. These results suggest that the IL‐6 family of cytokines mediates ET‐1‐induced expression of some fetal genes in cardiac myocytes.
GDNF triggers a novel Ret‐independent Src kinase family‐coupled signaling via a GPI‐linked GDNF receptor α1
Authors: Poteryaev Dmitry , Titievsky Alexey , Sun Yun Fu , Thomas-Crusells Judith , Lindahl Maria , Billaud Marc , Arumäe Urmas , Saarma Mart
Published: July 2002

Glial cell line‐derived neurotrophic factor (GDNF) has potentially great clinical importance in the treatment of Parkinson's disease and several other neurodegenerative diseases, however its intracellular signaling mechanisms are poorly understood. Here we show that upon GDNF binding glycosyl‐phosphatidylinositol (GPI)‐linked GDNF receptor α1 (GFRα1) activates cytoplasmic Src family tyrosine kinase(s) in Ret tyrosine kinase‐deficient cultured mouse dorsal root ganglion neurons and in two Ret‐negative cell lines. GFRα1‐mediated Src‐type kinase activation subsequently triggers phosphorylation of mitogen‐activated protein kinase, cAMP response element binding protein and phospholipase Cγ. We therefore conclude that GDNF can activate intracellular signaling pathways Ret‐independently via GPI‐linked GFRα1.
Subcutaneous transposition of the ovary following hysterectomy
Authors: Fujiwara K. , Mohri H. , Yoshida T. , Yamauchi H. , Kohno I.
Published: July 2002

Objectives: Preservation of ovarian function at hysterectomy in pre‐menopausal women is desirable. A possibly malignant tumor from retained ovary is a concern. We demonstrate a new technique for exteriorization of the ovaries. Method: In 27 patients, the infundibulopelvic ligament was mobilized. The retroperitoneal space was then widely opened. The ovary was gently pulled through a fascial incision and fixed on the fascia followed by skin closure. Results: Cystic formation was common (66.7%). Four patients had extreme enlargement of the transposed ovary. A needle puncture revealed intra‐ovarian hematomas or fluid retention. One had puncture of the translocated ovary for in vitro fertilization more than two years following transposition. Conclusions: Possible advantages are (1) early detection and diagnosis of ovarian cysts, (2) easy surgical access to remove ovarian cysts, (3) transposition of ovaries outside the radiation field and (4) in vitro fertilization is facilitated. Comparative study for ovarian function is ongoing.
Gender violence and reproductive health
Authors: Diniz S.G , d'Oliveira A.F
Published: July 2002

The available literature reflects the growing interest in gender violence and reproductive health. Violence is generally studied by identifying pathologies, measuring their demands on services and evaluating their repercussions on fetal outcome. Institutional violence, however, has received little attention and is mainly concerned with the consequences of inappropriate use of technologies. Data from the Sexuality and Health Feminist Collective shows that among patients, 20.5% stated that they have never talked about their sexual life with their partners; 38.3% stated that they have had sexual intercourse against their will, including situations ranging from sexual harassment to rape which was referred by 12.3% of them. One of the most relevant issues arising from the anamnesis and interviews of these women was the violence to which they were submitted by health services. The high prevalence of violent situations indicates the urgency of incorporating an approach which deals with gender violence and promotes the empowerment of women into the routine of reproductive health services.
Egg activation: Upstream of the fertilization calcium signal
Authors: Ciapa Brigitte , Chiri Sandrine
Published: July 2002

Interaction of sperm and egg at fertilization induces well‐coordinated molecular events including specific recognition between species, adhesion and fusion, that lead to the formation of a zygote, a totipotent cell that develops into a new individual. A calcium signal, common to a great number of species, from marine invertebrates to mammals, is essential to activate the metabolism of the unfertilized oocyte. However, how fertilization triggers this calcium signal and initiates development of the early embryo is far from understood. The signaling pathways activated in eggs may be similar to those described in somatic cells, since changes in intracellular free calcium and in mitosis activating protein (MAP) kinase activity occur in both systems after activation. Several hypotheses are currently proposed, implying a spermatic ligand binding to a specific receptor expressed at the egg surface, or where the fused sperm either allows the transit of external calcium into the egg or injects one (or several) activating factor(s). It is still not known which of these ideas is true. We concentrate in this review on the possible signaling pathways involving IP3 (inositol trisphosphate), since its production is involved in most species to generate the fertilization calcium wave.
Removal of N‐glycans from cell surface proteins induces apoptosis by reducing intracellular glutathione levels in the rhabdomyosarcoma cell line S4MH
Authors: Calle Yolanda , Palomares Teodoro , Castro Begoña , Del Olmo Maite , Alonso‐Varona Ana
Published: July 2002

Summry— Expression of determined Asn‐bound glycans (N‐glycans) in cell surface glycoproteins regulates different processes in tumour cell biology. Specific patterns of N‐glycosylation are displayed by highly metastatic cells and it has been shown that inhibition of N‐glycan processing restrains cell proliferation and induces cell death via apoptosis. However, the mechanisms by which different N‐glycosylation states may regulate cell viability and growth are not understood. Since malignant cells express high levels of intracellular glutathione (GSH) and a reduction of intracellular GSH induces cell death via apoptosis, we investigated whether GSH was involved in the induction of apoptosis by removal of cell surface N‐glycans. We found that removal of N‐glycans from cell surface proteins by treating the rhabdomyosarcoma cell line S4MH with tunicamycin or N‐glycosidase resulted in a reduction in intracellular GSH content and cell death via apoptosis. Moreover, GSH depletion caused by the specific inhibitor of GSH synthesis BSO induced apoptosis in S4MH cells. This data indicates that adequate N‐glycosylation of cell surface glycoproteins is required for maintenance of intracellular GSH levels that are necessary for cell survival and proliferation.
A meta‐analysis of doctoral dissertations in purchasing
Authors: Das Ajay , Handfield Robert B.
Published: July 2002

Purchasing, as a distinct business function, has grown immensely in strategic stature over the past decade. However, the academic development of the field has not paralleled this turn of events. While the academic evolution of any field can be assessed in a variety of ways, doctoral dissertation research provides a useful method of evaluating the intellectual health of a discipline. We analyze doctoral dissertation research in the field of purchasing since 1987, identify key areas of study, examine shifts in topical coverage, evaluate methodological sophistication and the extent of theory development and discuss gaps in research areas. We find that dissertation research in purchasing is still largely exploratory, lacking in dominant paradigms and unifying theories. On a more positive note, our analysis reveals an encouraging trend towards causal and confirmatory research designs and the growing use of organizational, marketing and economic theory to explain purchasing phenomena.
Configurations in manufacturing strategy: a review and directions for future research
Authors: Bozarth Cecil , McDermott Chris
Published: July 2002

Configuration models have generated a great deal of interest in the business strategy area, as witnessed by a recent special issue in The Academy of Management Journal (Meyer et al., 1993). Despite this, there has been no effort to examine the current state or future role of configurational research in the manufacturing strategy area. This paper attempts to fill this gap. The first half positions configurations as a unique way of studying strategic fit issues. The second half of the paper examines the current state of configurational research in the manufacturing strategy area. We compare and contrast existing typologies and taxonomies, identify trends, and highlight possible gaps in the literature. Finally, we discuss how configuration models can play an important role in the study of dynamic manufacturing issues; specifically, the development, implementation, and change of manufacturing strategies.
A new rabbit model for the study on cervical compressive myelopathy
Authors: Kanchiku Tsukasa , Taguchi Toshihiko , Kaneko Kazuo , Yonemura Hiroshi , Kawai Shinya , Gondo Toshikazu
Published: July 2002

Development process and pathology of myelopathy due to chronic spinal cord compression have not been fully elucidated. This study was conducted in order to establish an experimental model which can efficiently produce myelopathy and be useful in the studies on myelopathy due to chronic spinal cord compression. Under electrophysiological monitoring of the spinal cord, anterior compression was produced on C5 using a plastic screw. Two weeks later, a plastic plate was inserted under the C5 arch. For the subsequent 10 months on average, walking pattern and MR images were periodically monitored. Before the sacrifice, electro‐physiological test was performed and then histopathological examination was done. Palsy appeared at 5 months on average after the addition of posterior compression. Mean compression ratio of the spinal cord calculated on MR images was 34%. All animals with compression showed a high intramedullary signal intensity, and the mean contrast‐to‐noise ratio (CNR) in the compressed area was 49%. Electrophysiological test showed a significant decrease in the amplitude of spinal cord evoked potentials (SCEPs) at the given compression level. Histology showed flattening of the anterior horn, disappearance and necrosis of anterior horn cells in the gray matter; and demyelination and axonal degeneration in the white matter. The antero‐posterior compression produces the condition of spinal canal stenosis. Repeated antero‐posterior compression to the spinal cord is important in establishing myelopathy. The present animal model was evaluated to be useful in the studies on myelopathy. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
GDF‐5 deficiency in mice alters the ultrastructure, mechanical properties and composition of the Achilles tendon
Authors: Mikic Borjana , Schalet Benjamin J. , Clark Randall T. , Gaschen Veronique , Hunziker Ernst B.
Published: July 2002

Acromesomelic dysplasia of the Hunter‐Thompson and Grebe types are rare human disorders based on growth/differentiation factor (GDF)‐5/CDMP‐1 genetic mutations. Numerous skeletal abnormalities are present in these individuals, including shortened limb bones and severe dislocations of the knee. In the GDF‐5 deficient brachypodism mouse, similar, although less severe, phenotypes are observed. It is unknown whether the joint dislocations observed in these disorders are due to a defect in the original formation of joints such as the knee, or to abnormalities in the tendons and ligaments themselves. We hypothesized that tendons from GDF‐5 deficient mice would exhibit altered composition, mechanical properties, and ultrastructure when compared with heterozygous control littermates. GDF‐5 deficient Achilles tendons were structurally weaker than controls, and structural strength differences appeared to be caused by compromised material properties: after normalizing by collagen per unit length, mutant tendons were still 50% weaker (P < 0.0001) and 50% more compliant (P < 0.001) than controls. Despite comparable levels of skeletal maturity in the two cohorts, the majority of mutant tendon failures occurred in the mid‐substance of the tendon (64% of all failures), whereas the majority of control failures occurred via avulsion (92% of all failures). Mutant Achilles tendons contained 40% less collagen per microgram of DNA when compared to controls (P = 0.004). No significant difference in glycosaminoglycan (GAG)/DNA was detected. Ultrastructural analyses indicated a slight trend toward increased frequency of small diameter (30‐100 nm) collagen fibrils in the mutant Achilles. Our findings suggest that increased tendon and ligament laxity may be the cause of the joint dislocations seen in patients with Hunter—Thompson and Grebe type dysplasia, rather than developmental abnormalities in the joints themselves. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.