bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of bioactive glass particles and their ionic products on intracellular concentrations
Authors: Laquerriere Patrice , Jallot Edouard , Kilian Laurence , Benhayoune Hicham , Balossier Gérard
Published: May 2003

Numerous studies have described the bioactive properties of glass particles in the SiO2‐CaO‐Na2O‐P2O5 system. This kind of material is capable of developing a direct contact with bone through dissolution and physicochemical reactions. We have investigated the influence of bioactive particles, and ionic products from the same particles, on the intracellular concentrations in monocyte cells, which are among the first cells to colonize implantation sites. The only way to access these concentrations and particularly diffusible ionic concentrations (potassium, sodium, and chlorine) is to use cryomethods coupled to electron probe microanalysis. We have paid particular attention to the potassium:sodium ratio, the most sensitive criterion of viability. We have cultured cells with bioactive glass particles and in a conditioned medium obtained from the dissolution of the glass particles in the standard medium. Our study demonstrates that cells cultured in a conditioned medium are more active than cells cultured in a standard medium, or cells exposed to bioactive particles, and particles are more toxic for cells than are ionic products. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 441–446, 2003
Biodegradation of polyurethane under fatigue loading
Authors: Wiggins Michael J. , Anderson James M. , Hiltner Anne
Published: May 2003

A method utilizing expansion of a diaphragm‐type film specimen was developed to study in vitro biodegradation of poly(etherurethane urea) (PEUU) under conditions of dynamic loading (fatigue). A finite element model was used to describe the strain state, which ranged from uniaxial at the edges of the film to balanced biaxial tensile strain at the center. During testing, the film was exposed to a H2O2/CoCl2 solution, which simulated in vivo oxidative biodegradation of PEUU. The extent of chemical degradation was determined by infrared analysis. Physical damage of the film surface was characterized by optical microscopy and scanning electron microscopy. Dynamic loading did not affect the rate of degradation relative to unstressed and constant stress (creep) controls in regions of the film that experienced primarily uniaxial fatigue; however, degradation was accelerated in regions that experienced balanced biaxial or almost balanced biaxial fatigue. It was concluded that the combination of dynamic loading and biaxial tensile strain accelerated oxidative degradation in this system. Chemical degradation produced a brittle surface layer that was marked by numerous pits and dimples. Physical damage of the surface in the form of cracking occurred only in fatigue experiments. Cracking was not observed in unstressed or creep tests. Cracks initiated at the dimples produced by chemical degradation, and propagated in a direction that was determined by the strain state. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 524–535, 2003
hMad4, c‐Myc endogenous inhibitor, induces a replicative senescence‐like state when overexpressed in human fibroblasts
Authors: Marcotte Richard , Qian Jing‐Fang , Chen James , Wang Eugenia
Published: May 2003

Mad family proteins have an antagonistic action on Myc‐dependent cell proliferation and transformation. We isolated a human cDNA clone, human Mad4 (hMad4), encoding a polypeptide of 209 amino acid residues, exhibiting 90% identity with mouse Mad4. Northern blot analysis shows that hMad4 probe hybridizes to a 3.8 kb message; its expression is highest in quiescent human WI38 fibroblasts. Among tissues, hMad4 mRNA is most abundant in brain, lung, and muscle. Consistent with other members of the Mad family, hMad4 can repress the transactivation activity of Myc/Max heterodimers on an E‐box chloramphenicol acteyl transferase (CAT) reporter plasmid; inhibition of both proliferation and clonogenic formation of hMad4‐infected cells correlates with the in vitro reporter repression. Moreover, infection of young human fibroblasts induces a replicative senescence‐like state. This phenotype was accompanied by s‐β‐galactosidase and PAI‐1 expression. These results suggest that hMad4 might be an important regulator of replicative senescence in human cells. J. Cell. Biochem. 89: 576–588, 2003. © 2003 Wiley‐Liss, Inc.
Expression of CXCR4 and CXCL12 (SDF‐1) in human prostate cancers (PCa) in vivo
Authors: Sun Yan‐Xi , Wang Jingcheng , Shelburne Charles E. , Lopatin Dennis E. , Chinnaiyan Arul M. , Rubin Mark A. , Pienta Kenneth J. , Taichman Russell S.
Published: May 2003

Human prostate cancers (PCa) express great variability in their ability to metastasize to bone. The identification of molecules associated with aggressive phenotypes will help to define PCa subsets and will ultimately lead to better treatment strategies. The chemokine stromal‐derived factor‐1 (SDF‐1 or CXCL12) and its receptor CXCR4 are now known to modulate the migration and survival of an increasing array of normal and malignant cell types including breast, pancreatic cancers, glioblastomas, and others. The present investigation extends our previous investigations by determining the expression of CXCR4 and CXCL12 in humans using high‐density tissue microarrays constructed from clinical samples obtained from a cohort of over 600 patients. These data demonstrate that CXCR4 protein expression is significantly elevated in localized and metastastic cancers. At the RNA level, human PCa tumors also express CXCR4 and message, but overall, they were not significantly different suggesting post‐transcriptional regulation of the receptor plays a major role in regulating protein expression. Similar observations were made for CXCL12 message, but in this case more CXCL12 message was expressed by metastastic lesions as compared to normal tissues. PCa cell lines also express CXCL12 mRNA, and regulate mRNA expression in response to CXCL12 and secrete biologically active protein. Furthermore, neutralizing antibody to CXCL12 decreased the proliferation of bone homing LNCaP C4‐2B and PC3 metastastic tumor cells. These investigations provide important new information pertaining to the molecular basis of how tumors may ‘home’ to bone, and the mechanisms that may account for their growth in selected end organs. © 2003 Wiley‐Liss, Inc.
Identification of a domain within MDMX‐S that is responsible for its high affinity interaction with p53 and high‐level expression in mammalian cells
Authors: Rallapalli Ravikumar , Strachan Gordon , Tuan Rocky S. , Hall David J.
Published: May 2003

The MDMX gene product is related to the MDM2 oncoprotein, both of which interact with the p53 tumor suppressor. A novel transcript of the MDMX gene has been previously identified that has a short internal deletion of 68 base pairs, producing a shift in the reading frame after codon 114, resulting in the inclusion of 13 novel amino acids (after residue 114) followed by a stop codon at amino acid residue 127. This truncated MDMX protein, termed MDMX‐S, represents only the p53 binding domain and binds and inactivates p53 better than full‐length MDMX or MDM2. Here we show that when expressed in cells, MDMX‐S is targeted more efficiently to the nucleus than MDMX. MDMX‐S suppresses p53‐mediated transcription from a p53 target promoter better than full‐length MDMX. The DNA damage inducibility of these p53 responsive promoters was suppressed better by MDMX‐S than by MDMX. Analysis of the MDMX‐S protein indicated that the 13 novel amino acids at its carboxy terminus was responsible for high affinity binding to p53 in vitro and for high level expression of the protein in cells. Deletion of this 13 amino acid sequence resulted in a protein that was not able to bind p53 and was not able to be expressed well in cells. Taken together, these data point to an important domain within MDMX‐S that enables it to function well in vivo to block p53 activity. Published 2003 Wiley‐Liss, Inc.
Apoptotic effect of cleaved high molecular weight kininogen is regulated by extracellular matrix proteins
Authors: Guo Yan‐Lin , Wang Shujie , Cao Dian J. , Colman Robert W.
Published: May 2003

We previously reported that cleaved high molecular weight kininogen (HKa) and its domain 5 (D5) inhibit critical steps required for angiogenesis and in vivo neovascularization (Colman et al. 2000: Blood 95:543–550). We have further shown that D5 is able to induce apoptosis of endothelial cells, which may represent a critical part of the anti‐angiogenic activity of HKa and D5 (Guo et al. 2001: Arterioscler Thromb Vasc Biol 21:1427–1433). In this study, we demonstrate that HKa‐ and D5‐induced apoptosis is closely correlated with their anti‐adhesive effect. An important new finding is that the apoptotic activity of HKa and D5 is highly regulated by their interactions with different extracellular matrix (ECM) proteins. HKa inhibited cell adhesion to vitronectin (Vn, 90%) and gelatin (Gel) (40%), but it had no apparent effect on cell adhesion to fibronectin (Fn). D5 showed a similar pattern on cell adhesion but was less potent than HKa. HKa induced apoptosis of endothelial cells grown on Vn and Gel but not cells grown on Fn which closely parallels with its anti‐adhesive potency. Further results revealed that the anti‐adhesive effect and the apoptotic effect of HKa are associated with its ability to inhibit phosphorylation of focal adhesion kinase (FAK) and paxillin, two important signal molecules required for cell adhesion and cell viability. We conclude that the anti‐adhesive activity of HKa and D5 is responsible for their apoptotic effect and that Vn is likely an ECM component that mediates the effect of HKa and D5. © 2003 Wiley‐Liss, Inc.
Phytoestrogen genistein acts as an estrogen agonist on human osteoblastic cells through estrogen receptors α and β
Authors: Rickard D.J. , Monroe D.G. , Ruesink T.J. , Khosla S. , Riggs B.L. , Spelsberg T.C.
Published: May 2003

Genistein, a soybean isoflavone, has estrogen‐like activity in mammals, including the prevention of bone loss. However, whether its mechanism of action on bone turnover is distinct from that of estrogen or raloxifene is unknown. Although genistein has been reported to bind both estrogen receptor (ER) isoforms (α and β), little is known concerning differential activation of gene expression via these ER isoforms. To examine this question, comparison of the responses of normal fetal osteoblast (hFOB) cells stably expressing either ERα (hFOB/ERα9) or ERβ (hFOB/ERβ6), to treatment with genistein, 17β‐estradiol (E2) or raloxifene were conducted. In hFOB/ERα9 cells, both genistein and E2 increased the endogenous gene expression of the progesterone receptor (PR), the proteoglycan versican, and alkaline phosphatase (AP), but inhibited osteopontin (OP) gene expression and interleukin‐6 (IL‐6) protein levels. Raloxifene had no effect on these bone markers. Genistein, but not raloxifene, also mimicked E2 action in the hFOB/ERβ6 cells increasing PR gene expression and inhibiting IL‐6 production. To determine whether the gene regulatory actions of genistein in human osteoblast cells occur at the level of transcription, its action on the transcriptional activity of a PR‐A promoter‐reporter construct was assessed. Both genistein and E2 were found to stimulate the PR promoter in the hFOB cell line when transiently co‐transfected with either ERα or ERβ. Whereas hFOB cell proliferation was unaffected by E2, raloxifene or genistein at low concentrations, higher concentrations of genistein, displayed significant inhibition. Together, these findings demonstrate that genistein behaves as a weak E2 agonist in osteoblasts and can utilize both ERα and ERβ. © 2003 Wiley‐Liss, Inc.
Impact on survivors of retinoblastoma when informed of study results on risk of second cancers
Authors: Schulz Charlene J. , Riddle Mary P. , Valdimirsdottir Heiddis B. , Abramson David H. , Sklar Charles A.
Published: May 2003

Background

To assess the impact of providing research feedback to retinoblastoma survivors or their parents regarding the risk of second cancers.

Procedure

A four‐page survey was sent to 801 retinoblastoma survivors and 55 parents to ascertain their reactions to a “results‐letter.” The “results‐letter” provided feedback from a study indicating that retinoblastoma survivors may be at increased risk of second cancers.

Results

Three hundred and thirty‐nine (339) retinoblastoma survivors and 43 parents responded to the survey. Eighty‐four percent (84%) of respondents found the “results‐letter” “very” to “extremely” understandable and 72% found it “very” to “extremely” useful. Participants scored “very” to “extremely” to the following emotions: frightened = 28%, anxious = 27%, sad = 25%, overwhelmed = 15%, angry = 11%, and guilty = 6%. Five (1.4%) respondents stated that they would have preferred not to receive the results. Responses did not vary significantly between survivors with different risks of second cancers. No significant differences were observed between males and females. However, parents were significantly more likely to report feelings of anxiety, guilt, anger, being overwhelmed, and frightened compared to adult retinoblastoma survivors (P < 0.05). Individuals with less than a college education were significantly more sad, angry, overwhelmed, and frightened by the information than individuals with a college degree or higher (P < 0.05). Eighteen percent (18%) of all respondents shared the feedback with their physician. The method of choice for receiving results was by letter with contact names and phone numbers.

Conclusions

These findings indicate that research participants want feedback even when the information is upsetting. Additional studies are needed to identify individuals who experience greater levels of distress following feedback in an attempt to provide improved methods of feedback and support. Med Pediatr Oncol 2003;41:36–43. © 2003 Wiley‐Liss, Inc.
Computation of infinite integrals involving three Bessel functions by introduction of new formalism
Authors: Fabrikant V.I.
Published: May 2003

It has been accepted by many scientists, that whatever can be done in the field of evaluation of integrals of Bessel functions, had already been done, and that nothing new or important can be introduced at this stage. This article is written to disprove such a notion. Introduction of a new and elegant formalism not only allows simple computations of various integrals in terms of elementary functions, it also allows to discover errors (or misprints) in long standing results, which by now have entered practically all respectable tables of integrals.
Effect of transmembrane Ca2+ gradient on Gs function
Authors: Fan Gao-feng , Huang You-guo , Bai Yan-hong , Yang Fu-yu
Published: May 2003

Gs and adenylate cyclase from bovine brain cortices were co‐reconstituted into asolectin liposomes with or without 1000‐fold transmembrane Ca2+ gradient. Obtained results showed that Gs activities of both binding GTPγS and stimulating adenylate cyclase were the highest in proteoliposomes, with a transmembrane Ca2+ gradient similar to the physiological situation and the lowest while the transmembrane Ca2+ gradient was in the inverse direction. Such a difference could be diminished following the dissipation of the transmembrane Ca2+ gradient by A23187. Time‐resolved fluorescence anisotropy of diphenylhexatriene (DPH) has been used to compare the physical state of phospholipids among those proteoliposomes. It is suggested that a proper transmembrane Ca2+ gradient is essential for higher membrane fluidity, which may favor Gs function with higher GTP‐binding activity and stimulation of adenylate cyclase.
Transcriptional repression mediated by the serum response factor
Authors: Ernst Wolfram H. , Janknecht Ralf , Cahill Michael A. , Nordheim Alfred
Published: May 2003

The serum response element (SRE) contributes to transcriptional repression of the c‐fos proto‐oncogene. We show that the transcription factor SRF is able to repress SRE‐dependent transcription, apparently by sequestering a co‐activator. Only the DNA‐binding core region is required for this SRE‐dependent repression. Furthermore the phosphorylation status at potential casein kinase II sites within an N‐terminal repression domain affects SRE‐independent transcription. SRF may thus pleiotropically influence cellular transcription, representing a novel aspect of SRF function.
A 70 kDa protein is transferred from the outer acrsomal to the plasma membrane during capacitation
Authors: Spungin Ben , Margalit Ilana , Breitbart Haim
Published: May 2003

Bull sperm plasma and outer acrosomal membranes were analyzed by SDS‐PAGE. Analysis of the plasma membrane proteins revealed the presence of a 70 kDa band the prominence of which is enhanced after capacitation. This protein was found to bind to zona pellucida intact oocytes. PAGE analysis of outer acrosomal membrane proteins also reveals the presence of a 70 kDa band, but its prominence decreases after capacitation. This protein also binds to zona pellucida intact oocytes. Futhermore, the 70 kDa outer acrosomal membrane protein is recognized in Western blot analysis by antibodies to plasma membrane proteins and vice versa. The results indicate that the 70 kDa acrosomal and plasma membrane proteins are the same. This 70 kDa protein would thus be a zona pellucida binding protein which is initially stored in the outer acrosomal membrane and transferred to the plasma membrane during capacitation, enabling it to function in egg‐sperm binding.
A human de‐ubiquitinating enzyme with both isopeptidase and peptidase activities in vitro
Authors: Falquet Laurent , Paquet Nicole , Frutiger Séverine , Hughes Graham J. , Hoang-Van Khan , Jaton J.-C.
Published: May 2003

Some enzymatic and physicochemical properties of a human ubiquitin‐specific isopeptidase are reported. The enzyme was purified to homogeneity from red blood cells and its specificity towards polymeric ubiquitin substrates suggests a de‐ubiquitinating activity capable of cleaving ‘head‐to‐tail’ polyUb chains as well as isoamide ‘branched’ Ub dimers. K
M values show a 10 fold preference for the cleavage of branched Ub dimers over head‐to‐tail Ub dimers. The enzymatic activity can be strongly inhibited by various peptides containing either of the cleavage site sequences found in Ub polymers, but not by unrelated peptides. The enzyme is monomeric under reducing conditions and exhibits a globular shape with an average diameter of 9 nm, an S20,w value of 5.2 S and a molar mass of 110 kDa ± 10%. Because the enzyme cleaves both peptide‐linked and isopeptide‐linked Ub moieties from substrates, we propose to name it de‐ubiquitinase rather than isopeptidase.
Squamous cell carcinoma antigen is a potent inhibitor of cysteine proteinase cathepsin L
Authors: Takeda Atsushi , Yamamoto Takako , Nakamura Yoshiko , Takahashi Tadahito , Hibino Toshihiko
Published: May 2003

A squamous cell carcinoma antigen (SSCA), which is a member of the serpin family of proteinase inhibitors, was purified from sera of cancer patients. It did not inhibit serine proteinases. However, it non‐competitively inhibited human cathepsin L with a K
i of 0.064 nM, but not cathepsins B and H among cysteine proteinases. These results indicated that SCCA is a non‐functional serpin that inhibits cathepsin L in cancer cells.
Dual effects of microwaves on single Ca2+‐activated K+ channels in cultured kidney cells Vero
Authors: Geletyuk Vitaliy I. , Kazachenko Vladimir N. , Chemeris Nicolay K. , Fesenko Evgeniy E.
Published: May 2003

Using the patch voltage‐clamp method, possible effects of millimetre microwaves (42.25 GHz) on single Ca2+‐activated K+ channels in cultured kidney cells (Vero) were investigated. It was found that exposure to the field of non‐thermal power (about 100 μW/cm2) for 20–30 min greatly modifies both the Hill coefficient and an apparent affinity of the channels for Cai
2+. The data suggest that the field alters both cooperativity and binding characteristics of the channel activation by internal Ca2+. The effects depend on initial sensitivity of the channels to Ca2+ and the Ca2+ concentration applied.
A ciliary K+ conductance sensitive to charibdotoxin underlies inhibitory responses in toad olfactory receptor neurons
Authors: Morales Bernardo , Labarca Pedro , Bacigalupo Juan
Published: May 2003

In olfactory neurons from Caudiverbera caudiverbera, a mixture of putrid odorants trigger an inhibitory, K+‐selective current and a hyperpolarizing receptor potential. The current‐voltage relation resembles that of a Ca2+‐activated K+ conductance; their amplitude depends on extracellular Ca2+. 10 nM charibdotoxin, a blocker of K+‐selective channels, including Ca2+‐activated ones, reversibly abolished inhibitory currents and receptor potentials. Focal stimulation demonstrates that the underlying transduction mechanism is confined to the cilia. This represents the first evidence for inhibitory responses in vertebrate olfactory cells mediated by a ciliary CTX‐sensitive K+ conductance, most likely a Ca2+‐activated one.
Mitochondrial presequences can induce aggregation of unfolded proteins
Authors: Endo Toshiya , Mitsui Satoko , Roise David
Published: May 2003

We have studied the interactions between various synthetic peptides and two model unfolded proteins, reduced α‐lactalbumin and reduced and carboxymethylated α‐lactalbumin. We found that mitochondrial presequences could induce aggregation of the unfolded α‐lactalbumins but not of the native α‐lactalbumin. The presequence‐induced aggregation of unfolded α‐lactalbumin was dependent on electrostatic interactions and on the amphiphilicity of the presequences. Since positive charge and amphiphilicity are necessary for the targeting function of mitochondrial presequences, presequence‐induced aggregation may be responsible for the instability of mitochondrial precursor proteins and may need to be inhibited by binding factors in the cytosol.
Binding of progastrin fragments to the 78 kDa gastrin‐binding protein
Authors: Baldwin Graham S.
Published: May 2003

The non‐selective gastrin/cholecystokinin receptor antagonists proglumide and benzotript inhibit colon carcinoma cell proliferation by binding to the 78 kDa gastrin‐binding protein (GBP) (Baldwin, Proc. Natl. Acad. Sci. USA, 91 (1994) 7593–7597). However, although most colon carcinoma cell lines synthesize progastrin, production of mature amidated gastrin17 has not been observed. In order to define the structural requirements for the binding of gastrin to the GBP the affinities of various fragments of amidated and C‐terminally extended gastrin17 for the GBP have been measured. The results indicate that the GBP recognizes both N‐ and C‐termini of gastrin17. Moreover since C‐terminal amidation is not a prerequisite for binding of gastrin to the GBP, the GBP is a potential target for the autocrine effects of progastrin.
Expression and folding of an interleukin‐2‐proinsulin fusion protein and its conversion into insulin by a single step enzymatic removal of the C‐peptide and the N‐terminal fused sequence
Authors: Castellanos-Serra Lila R. , Hardy Eugenio , Ubieta Raimundo , Vispo Nelson S. , Fernandez Cesar , Besada Vladimir , Falcon Viviana , Gonzalez Marta , Santos Alicia , Perez Gudelia , Silva Alejandro , Herrera Luis
Published: May 2003

We report the expression in E. coli of a proinsulin fusion protein carrying a modified interleukin‐2 N‐terminal peptide linked to the N‐terminus of proinsulin by a lysine residue. The key aspects investigated were: (a) the expression of the fused IL2‐PI gene, (b) the folding efficiency of the insulin precursor when still carrying the N‐fused peptide and (c) the selectivity of the enzymatic cleavage reaction with trypsin in order to remove simultaneously the C‐peptide and the N‐terminal extension. It was found that this construction expresses the chimeric proinsulin at high level (20%) as inclusion bodies; the fused protein was refolded at 100–200 μg/ml to yield about 80% of correctly folded proinsulin and then it was converted into insulin by prolonged reaction (5 h) with trypsin and carboxypeptidase B at a low enzyme/substrate rate (1:600). This approach is based on a single enzymatic reaction for the removal of both the N‐terminal fused peptide and the C‐peptide and avoids the use of toxic cyanogen bromide.
Ascorbate is the natural substrate for plant peroxidases
Authors: Mehlhorn H. , Lelandais M. , Korth H.G. , Foyer C.H.
Published: May 2003

Ascorbate‐dependent detoxification of hydrogen peroxide by guaiacol‐type peroxidases is increased considerably in the presence of 3,4‐dihydroxyphenolic compounds, suggesting that ascorbate is the natural substrate for many types of peroxidase in situ and not just the ascorbate‐specific peroxidases. The ascorbate‐dependent destruction of hydrogen peroxide in the more acidic cellular compartments such as the vacuole may be an important function of such non‐specific peroxidases. The stress‐induced production of phenolic compounds would render the guaiacol peroxidases in other less acidic‐cellular sites effective as ascorbate‐dependent H2O2‐detoxifying enzymes.
Presence of long and short dystrophin and/or utrophin products in Torpedo marmorata peripheral nerves
Authors: Rivier François , Robert Agnès , Latouche Jacqueline , Hugon Gérald , Mornet Dominique
Published: May 2003

Peripheral nerves from rabbit and Torpedo marmorata were comparatively analyzed for the presence of short dystrophin products. Western blot analyses of Torpedo marmorata peripheral nerve extracts revealed the existence of three proteins belonging to the dystrophin family: a M
r 400 kDa protein band detected with dystrophin/utrophin, dystrophin‐specific and Torpedo utrophin‐specific antibodies, a molecule identified as Dp116 and, for the first time at the protein level, a new protein probably corresponding to Up116. All of these products were carefully identified according to the specificities of the monoclonal antibodies used. In immunofluorescence studies, clear staining of the thin rim surrounding each Schwann cell‐axon unit was observed in both Torpedo marmorata and rabbit peripheral nerves, showing colocalization of all of these molecules. Their potential functions were discussed in comparison to similar products found in rabbit peripheral nerves.
Effects of pathological mutations on the stability of a conserved amino acid triad in retinoschisin
Authors: Fraternali Franca , Cavallo Luigi , Musco Giovanna
Published: May 2003

A three‐dimensional model has been calculated for the discoidin domain of retinoschisin (RS1), the protein involved in the X‐linked juvenile retinoschisis. The model allows for a mapping of the pathological retinoschisis missense mutations and a rationale for the structural effects of an evolutionary conserved surface exposed triad (W122–R200–W163). Molecular dynamics simulations of the triad mutants models, together with ab initio energy calculations of the complexes corresponding to the triad show that the observed pathological mutations sensibly destabilize local interactions and the entire fold. Moreover the presented model reveals evidence of a putative site for membrane association.
Pretreatment of indole‐3‐carbinol augments TRAIL‐induced apoptosis in a prostate cancer cell line, LNCaP
Authors: Jeon Kye-Im , Rih Jeong-Keun , Kim Hee Jeong , Lee Yong J , Cho Chi-Heum , Goldberg Itzhak D , Rosen Eliot M , Bae Insoo
Published: May 2003

Prostate cancer is one of the most common cancers in men and is the second leading cause of cancer‐related deaths in the USA. Many anti‐tumor agents against prostate cancer cells have been developed, but their unacceptable systemic toxicity to normal tissues frequently limits their usage in clinics. Several previous studies have demonstrated that tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) can induce cell death in a variety of transformed cells including prostate cancer cells, but not normal cells. Indole‐3‐carbinol (I3C), a phytochemical that is produced in fruits and vegetables, may play an important role in the prevention of many types of cancer, including hormone‐related ones such as breast and prostate cancer. In this study, we examined the potential sensitizing effects of I3C on TRAIL‐mediated apoptosis in a prostate cancer cell line, LNCaP. When LNCaP cells were incubated with I3C (either 30 or 90 μM) for 24 h and then treated with TRAIL (100 ng/ml), enhanced TRAIL‐mediated apoptosis was observed. The enhanced apoptosis measured by poly(ADP‐ribose) polymerase and caspase 3 cleavage. We also observed that loss of cell viability after treatment with I3C/TRAIL is greater compared with I3C and TRAIL alone. To determine the molecular mechanisms involved in the enhanced apoptosis, we examined the expression of two TRAIL death receptors (DR4 and DR5) and two TRAIL decoy receptors (DcR1 and DcR2). We found that treatment with I3C induced DR4 and DR5 expression at both transcriptional and translational levels. These findings suggest that I3C may be an effective sensitizer of TRAIL treatment against TRAIL‐resistant prostate cancer cell lines such as LNCaP.
Unusual nucleotide‐binding properties of the chloroplast protein import receptor, atToc33
Authors: Aronsson Henrik , Combe Jonathan , Jarvis Paul
Published: May 2003

Arabidopsis Toc33 (atToc33) is a GTP‐binding protein of the chloroplast outer envelope membrane. We studied its nucleotide‐binding properties in vitro, and found that it binds GTP, GDP and XTP, with similar efficiencies, but not ATP. We further demonstrated that atToc33 has intrinsic GTPase activity. Mutations within the putative G4 motif of the atToc33 nucleotide‐binding domain (D217N, D219N and E220Q) had no effect on nucleotide specificity or GTPase activity. Similarly, a mutation in the newly assigned G5 motif (E208Q) did not affect nucleotide specificity or GTPase activity. Furthermore, the D217N and D219N mutations did not affect atToc33 functionality in vivo. The data demonstrate that atToc33 belongs to a novel class of GTPases with unusual nucleotide‐binding properties.
Quaternary structure of alpha‐crustacyanin from lobster as seen by small‐angle X‐ray scattering
Authors: Dellisanti Cosma D , Spinelli Silvia , Cambillau Christian , Findlay John B.C , Zagalsky Peter F , Finet Stéphanie , Receveur-Bréchot Véronique
Published: May 2003

The structure of α‐crustacyanin, the blue carotenoprotein of lobster (Homarus gammarus) carapace, has been investigated for the first time using small‐angle X‐ray scattering. In this paper, we have determined the dimensions of this protein composed of eight heterodimeric subunits of β‐crustacyanin. Analysis of the scattering spectra and estimation of the shape of α‐crustacyanin show that the protein fits into a cylinder with an axial length of 238 Å and a radius of 47.5 Å, in which the eight β‐crustacyanin molecules are probably arranged in a helical manner.
Subsite mapping of human salivary α‐amylase and the mutant Y151M
Authors: Kandra Lili , Gyémánt Gyöngyi , Remenyik Judit , Ragunath Chandran , Ramasubbu Narayanan
Published: May 2003

This study characterizes the substrate‐binding sites of human salivary α‐amylase (HSA) and its Y151M mutant. It describes the first subsite maps, namely, the number of subsites, the position of cleavage sites and apparent subsite energies. The product pattern and cleavage frequencies were determined by high‐performance liquid chromatography, utilizing a homologous series of chromophore‐substituted maltooligosaccharides of degree of polymerization 3–10 as model substrates. The binding region of HSA is composed of four glycone and three aglycone‐binding sites, while that of Tyr151Met is composed of four glycone and two aglycone‐binding sites. The subsite maps show that Y151M has strikingly decreased binding energy at subsite (+2), where the mutation has occurred (−2.6 kJ/mol), compared to the binding energy at subsite (+2) of HSA (−12.0 kJ/mol).
An archaeal homing endonuclease I‐PogI cleaves at the insertion site of the neighboring intron, which has no nested open reading frame1
Authors: Nakayama Hitoshi , Morinaga Yayoi , Nomura Norimichi , Nunoura Takuro , Sako Yoshihiko , Uchida Aritsune
Published: May 2003

Homing endonucleases (HEs) of the LAGLIDADG family cleave intron/inteinless cognate DNA at, or near, the insertion site (IS) of their own intron/intein. Here, we describe a notable exception to this rule. Two introns, Pog.S1205 (length 32 bp) and Pog.S1213 (664 bp), whose ISs are 8 bp apart, exist within the 16S rRNA gene of the archaeon Pyrobaculum oguniense. Pog.S1213 harbors a nested open reading frame (ORF) encoding a 22 kDa monomeric protein, I‐PogI, which contains two LAGLIDADG motifs and has optimal DNA cleavage activity at 90°C. Intriguingly, I‐PogI cleaves the Pog.S1205‐less substrate DNA in the presence or absence of Pog.S1213. The cleavage site (CS) of I‐PogI does not coincide with the IS of Pog.S1213 but with that of Pog.S1205. Thus, I‐PogI activity both promotes the homing of its own intron, Pog.S1213, and guarantees co‐conversion of the ORF‐less intron Pog.S1205.
Cytokine induction of prolactin receptors mediates prolactin inhibition of nitric oxide synthesis in pulmonary fibroblasts
Authors: Corbacho Ana M. , Macotela Yazmin , Nava Gabriel , Eiserich Jason P. , Cross Carroll E. , Martı́nez de la Escalera Gonzalo , Clapp Carmen
Published: May 2003

Prolactin (PRL) has been implicated as a modulator of immune function, and some of its actions may be linked to NO synthesis. Because NO acts as a mediator of inflammation, we speculated that an inflammatory milieu could unmask pathways by which PRL could affect NO synthesis. Here, we show that pro‐inflammatory cytokines induce the expression of PRL receptors in pulmonary fibroblasts, allowing PRL to inhibit cytokine‐induced NO production and the expression of the inducible nitric oxide synthase (iNOS). Inhibition of iNOS expression by PRL correlates with the phosphorylation of STAT‐5b (signal transducer and activator of transcription 5b) and the suppression of expression of IRF‐1 (interferon regulatory factor 1), a transcription factor for iNOS. These results reveal previously unrecognized mechanisms by which PRL and PRL receptors may play significant modulatory roles during immune–inflammatory processes.
Induction of MafBx and Murf ubiquitin ligase mRNAs in rat skeletal muscle after LPS injection
Authors: Dehoux Mischaël J.M , van Beneden Ronald P , Fernández-Celemı́n Laura , Lause Pascale L , Thissen Jean-Paul M
Published: May 2003

MafBx and Murf are two new rat E3 ubiquitin ligases induced in muscle atrophy. Our goal was to investigate whether lipopolysaccharide (LPS) injection, a model of muscle catabolism, is associated with increased expression of MafBx and Murf. LPS (750 μg/100 g body weight) induces MafBx and Murf mRNA (respectively, 23‐fold and 33‐fold after 12 h; P<0.001). A transient induction of tumor necrosis factor‐α mRNA (21‐fold; P<0.001 at 3 h) and a decrease of insulin like growth factor‐I mRNA (50%; P<0.001 at 6 h), two potential regulators of the ubiquitin–proteasome system were also demonstrated. In summary, MafBx and Murf mRNA are up‐regulated in response to LPS and might play a role in the muscle proteolysis observed.
Monovalent cation dependence and preference of GHKL ATPases and kinases1
Authors: Hu Xiaojian , Machius Mischa , Yang Wei
Published: May 2003

The GHKL phosphotransferase superfamily, characterized by four sequence motifs that form the ATP‐binding site, consists of the ATPase domains of type II DNA topoisomerases, Hsp90, and MutL, and bacterial and mitochondrial protein kinases. In addition to a magnesium ion, which is essential for catalysis, a potassium ion bound adjacent to the triphosphate moiety of ATP in a rat mitochondrial protein kinase, BCK (branched‐chain α‐ketoacid dehydrogenase kinase), has been shown to be indispensable for nucleotide binding and hydrolysis. Using X‐ray crystallographic, biochemical, and genetic analyses, we find that the monovalent cation‐binding site is conserved in MutL, but both Na+ and K+ support the MutL ATPase activity. When Ala100 of MutL is substituted by proline, mimicking the K+‐binding environment in BCK, the mutant MutL protein becomes exclusively dependent on Na+ for the ATPase activity. The coordination of this Na+ ion is identical to that of the K+ ion in BCK and involves four carbonyl oxygen atoms emanating from the hinges of the ATP lid and a non‐bridging oxygen of the bound nucleotide. A similar monovalent cation‐binding site is found in DNA gyrase with additional coordination by a serine side chain. The conserved and protein‐specific monovalent cation‐binding site is unique to the GHKL superfamily and probably essential for both ATPase and kinase activity. Dependence on different monovalent cations for catalysis may be exploited for future drug design specifically targeting each individual member of the GHKL superfamily.
Modulation of the classical multidrug resistance (MDR) phenotype by RNA interference (RNAi)
Authors: Nieth Christiane , Priebsch Axel , Stege Alexandra , Lage Hermann
Published: May 2003

For reversal of MDR1 gene‐dependent multidrug resistance (MDR), two small interfering RNA (siRNA) constructs were designed to inhibit MDR1 expression by RNA interference. SiRNA duplexes were used to treat human pancreatic carcinoma (EPP85‐181RDB) and gastric carcinoma (EPG85‐257RDB) cells. In both cellular systems, siRNAs could specifically inhibit MDR1 expression up to 91% at the mRNA and protein levels. Resistance against daunorubicin was decreased to 89% (EPP85‐181RDB) or 58% (EPG85‐257RDB). The data indicate that this approach may be applicable to cancer patients as a specific means to reverse tumors with a P‐glycoprotein‐dependent MDR phenotype back to a drug‐sensitive one.
Baseline personality functioning correlates with 6 month outcome in schizophrenia
Authors: Fassino Secondo , Pierò Andrea , Mongelli Elena , Caviglia Maria Luisa , Delsedime Nadia , Busso Federica , Gramaglia Carla , Abbate Daga Giovanni , Leombruni Paolo , Ferrero Andrea
Published: May 2003

Objective

The assessment of outcome in schizophrenic patients should consider both the response to treatment and the recovery of social skills. The aim was to evaluate the outcome and related psychostructural and clinical factors in schizophrenic patients after they underwent 6 months of residential multimodal treatment.

Methods

Fifty-two schizophrenic patients enrolled in a multimodal treatment program were included in the study. Symptomatology and social functioning were assessed with the Brief Psychiatric Rating Scale (BPRS) and the Social and Occupational Functioning Assessment Scale (SOFAS). The Karolinska Psychodynamic Profile (KAPP) was used for the psychostructural evaluation.

Results

After 6 months there was a significant improvement in the global scores of BPRS, SOFAS, and some areas of KAPP. The personality (KAPP) and social-occupational functioning (SOFAS) at baseline (T0) correlated with the global score of BPRS at 6 months (T6); moreover, SOFAS at T6 correlated with BPRS and KAPP at T0 and with the illness duration.

Conclusions

The better the personality functioning in schizophrenic patients the better seems to be the response to treatment, with regard to symptoms as well as rehabilitation. Personality assessment might be useful for the individualisation of therapies, even within the context of a standardised program.
Recent evidence for dopamine abnormalities in schizophrenia
Authors: Abi-Dargham A.
Published: May 2003

Neuroreceptor imaging has been used to examine dopamine function in schizophrenia. The evidence from PET and SPECT studies suggests that there is excess dopamine release subcortically, in the striatum, and that dopaminergic transmission may be abnormal in the cortex also, because of an upregulation in D1 receptors. We have found that patients with schizophrenia have higher subcortical levels of intrasynaptic dopamine (and have a greater proportion of D2 receptors occupied by dopamine) at baseline than controls. Those patients who had the highest levels of dopamine were the ones whose positive symptoms responded best to six weeks of treatment with an antipsychotic. Recent studies have also produced new evidence of dopaminergic disturbance in the cortex. When controls were compared with patients with schizophrenia, we found a significant increase in D1 receptors in patients, but only in the dorsolateral prefrontal cortex. Patients were also studied while they undertook a test of working memory. While there was no relationship between test performance and D1 binding potential for controls, those patients with the highest densities (most pathological levels) of D1 receptors performed the worst on the test. Both the D1 upregulation and the poor working memory may be secondary to a chronic, possibly neurodevelopmental deficit in dopamine innervation of the dorsolateral prefrontal cortex in schizophrenia. The D1 binding potential may prove to be a good biomarker with which to identify those patients suffering from schizophrenia who are most likely to benefit from treatment with a D1 agonist. A D1 receptor radiotracer that is sensitive to endogenous dopamine competition would be very valuable in the further exploration of this area.
Russian banks’ profit strategies: the evidence from various types of banks
Authors: Gnezditskaia A.
Published: May 2003

This paper offers an analysis of profit strategies pursued by Russian banks depending on their ownership type, including federal state banks, banks of mixed ownership, banks connected to enterprises producing for the final consumers, and regional pocket banks owned by one particular business group or enterprise. The paper outlines a set of factors that capture a range of potential hindrances on the way to banks’ involvement in Russian economy. It traces how the characteristics of the state regulation and peculiarities of the economic sectors affect the proliferation of certain type of banks—pocket banks—at the expense of others. It looks into how the various types of banks function under the given set of political and economic constraints, and how these constraints shape the banking system in Russia and its relationships with the enterprises and sectors.
Small business in Russia—factors that slowed its development: an analysis
Authors: Kihlgren Alessandro
Published: May 2003

In Russia the growth of small business has been much slower compared with the leading transition countries (Poland, the Czech Republic and Hungary). In Poland, and to a lesser degree in the Czech Republic and Hungary, this sector has been the engine of the economic recovery. A natural question is why Russia differs. Apart from the fact that in contrast to these countries Russia does not have an entrepreneurial tradition and has experienced communist rule longer what is especially distinctive about Russia has been the strong influence of interest groups during the transition process which favoured the allocation of entrepreneurship to largely unproductive activities.
The paper‐bill spread and real output: what matters more, a change in the paper rate or a change in the bill rate?
Authors: Ewing Bradley T , Lynch Gerald J , Payne James E
Published: May 2003

This paper adds to the literature on the information content of the paper‐bill spread by explicitly taking into account the two sources of wider spreads, rises in the paper rate and declines in the bill rate. Results from impulse response analysis and variance decompositions suggest that decreases in real output are greater and last longer when a widening of the paper‐bill spread comes from an increase in the paper rate rather than from an equivalent decrease in the bill rate. This is consistent with the idea that changes in the commercial paper rate have greater information content about future business cycles than do changes in the Treasury bill rate.
Reduced‐intensity allogeneic hematopoietic cell transplantation: Graft versus tumor effects with decreased toxicity
Authors: Schwartz Jennifer E. , Yeager Andrew M.
Published: May 2003

Abstract: The potentially curative role of allogeneic hematopoietic cell transplantation (HCT) in neoplastic and non‐neoplastic diseases is offset by the substantial risks of morbidity and mortality from complications of the intensive myeloablative and immunosuppressive preparative regimen. These regimen‐related toxicities have restricted allogeneic HCT to young, otherwise healthy individuals without comorbid diseases. Pediatric patients undergoing conventional allogeneic HCT have lower procedure‐related mortality but are at risk for non‐fatal late effects of the high‐dose pretransplant chemoradiotherapy, such as growth retardation, sterility and other endocrine dysfunction. Evaluation of reduced‐intensity preparative regimens is the major focus of current clinical research in allogeneic HCT. Reduced‐intensity HCT (RI‐HCT) relies on the use of immunosuppressive but non‐myeloablative agents that allow engraftment of donor cells, which provide adoptive allogeneic cellular immunotherapy and graft versus tumor (GVT) effects, with decreased regimen‐related toxicities. Although the experience with RI‐HCT in pediatric patients is very limited at this time, results in adults indicate that attenuated‐dose preparative regimens allow older patients and those with organ dysfunction to undergo successful allogeneic HCT with acceptable morbidity and mortality. In adults, the potency of the allogeneic GVT effect varies among neoplastic diseases, with better results observed in patients with indolent hematological malignancies or renal cell carcinoma. The effectiveness of RI‐HCT as treatment for children with hemoglobinopathies, chronic granulomatous disease and cellular immunodeficiencies is encouraging, and the role of reduced‐intensity preparative regimens for allogeneic HCT in pediatric malignancies is under investigation.
Successful treatment of a patient with subcutaneous panniculitis‐like T‐cell lymphoma with high‐dose chemotherapy and total body irradiation
Authors: Mukai Harumi Y. , Okoshi Yasushi , Shimizu Seiichi , Katsura Yukitaka , Takei Naoko , Hasegawa Yuichi , Kojima Hiroshi , Mori Naoyoshi , Nagasawa Toshiro
Published: May 2003

Abstract: A 24‐yr‐old man was referred for fever, right cheek swelling, subcutaneous tumor and liver dysfunction. Physical examination showed an elastic hard subcutaneous tumor on the right cheek, left axillary lymph node swelling and multiple small subcutaneous tumors in the trunk. Laboratory examinations showed elevated levels of transaminase, soluble interleukin‐2 receptor and ferritin. Biopsy of the subcutaneous tumor showed proliferation of medium‐sized cells with abundant clear cytoplasm and hyperchromatic nuclei among the subcutaneous fat tissues. These cells showed CD3+, CD4−, CD8+, CD56− and CD20− phenotype and possessed cytotoxic molecules such as granzyme B and T‐cell intracellular antigen‐1. Bone marrow aspiration showed proliferation of small numbers of abnormal lymphocytes with severe hemophagocytosis. He was thus diagnosed as having subcutaneous panniculitis‐like T‐cell lymphoma (SPTCL) and treated with dose‐escalated CHOP regimen. After three courses of the chemotherapy, he was further treated with high‐dose chemotherapy and total body irradiation (TBI) with autologous peripheral blood stem cell rescue. Thereafter, he has been in remission for more than 2 yr. We consider that SPTCL with hemophagocytosis is an extremely aggressive disease, and high‐dose chemotherapy and TBI should be included for the choice of the treatment.