bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pro‐apoptotic therapy with the oligonucleotide GenasenseTM (oblimersen sodium) targeting Bcl‐2 protein expression enhances the biological anti‐tumour activity of rituximab
Authors: Ramanarayanan Jeyanthi , Hernandez‐Ilizaliturri Francisco J. , Chanan‐Khan Asher , Czuczman Myron S. 
Published: November 2004

SummaryNew strategies have evolved in the treatment of patients with non‐Hodgkin's lymphoma (NHL). Anti‐sense oligonucleotides (ASO) and monoclonal antibody (mAb) therapy, though proven to be safe and effective, have not demonstrated to be curative when used as single agents. We tested an innovative combination strategy involving various mAbs and ASO against Bcl‐2 (G3139) in aggressive preclinical models. G3139, under optimal transfection conditions, decreased the proliferation rate of lymphoma cells by 60–75% when compared with controls. In addition, apoptosis was demonstrated in Raji (25%) and DHL‐4 cells (30%) treated with Genasense following downregulation of Bcl‐2 protein. Downregulation of Bcl‐2 by G3139 was associated with a higher degree of rituximab‐associated, complement‐mediated cytotoxicity and antibody dependent cellular cytotoxicity when compared with rituximab alone‐treated controls. In vivo studies in severe combined immunodeficiency (SCID) mice clearly demonstrated synergistic activity between G3139 and rituximab. Treatment of lymphoma‐bearing SCID mice with G3139 for two consecutive days prior to each rituximab dose resulted in better disease control and survival than treatment with either agent alone or controls. Our findings suggest that Bcl‐2 downregulation by G3139, followed by the administration of rituximab is an efficient anti‐tumour strategy associated with improved survival in lymphoma‐bearing SCID mice.
Characterization of the imprinted polycomb gene L3MBTL, a candidate 20q tumour suppressor gene, in patients with myeloid malignancies
Authors: Bench Anthony J. , Li Juan , Huntly Brian J. P. , Delabesse Eric , Fourouclas Nasios , Hunt Adrienne R. , Deloukas Panos , Green Anthony R. 
Published: November 2004

SummaryChromosome 20q deletion is a recurrent chromosomal abnormality associated with myeloid malignancies. L3MBTL represents a strong candidate tumour suppressor gene since it lies within the common deleted region, is a member of the Polycomb‐like family, encodes the human homologue of a Drosophila tumour suppressor and is expressed within haematopoietic progenitor cells. We describe the structure of L3MBTL, identify two putative promoters each associated with two CpG islands and characterize a complex pattern of alternative splicing events. Mutation analysis of the gene in patients with and without a 20q deletion identified several polymorphisms but no acquired mutations. The two CpG islands spanning promoter 2 undergo monoallelic methylation in normal haematopoietic cells consistent with imprinting of L3MBTL. Samples from patients with a 20q deletion retained either the methylated or unmethylated allele but retention of the methylated allele did not correlate with reduction in L3MBTL mRNA levels. The absence of a correlation between L3MBTL methylation and transcription could be shown to reflect loss of imprinting in one patient. In addition, our results demonstrate that inactivation of L3MBTL is not a common occurrence in patients with a 20q deletion or in cytogenetically normal patients with polycythaemia vera.
Antibody levels in adult patients with coeliac disease during gluten‐free diet: a rapid initial decrease of clinical importance
Authors: Midhagen G. , Åberg A.‐K. , Olcén P. , Järnerot G. , Valdimarsson T. , Dahlbom I. , Hansson T. , Ström M. 
Published: November 2004

Abstract.Objective. Analysis of antibodies against tissue transglutaminase (tTG) has been shown valuable in the diagnosis of coeliac disease (CD) but how quickly serum titres decrease after introduction of a gluten‐free diet (GFD) is not known in adults. CD is a well‐recognized disorder amongst the general population and many persons try a GFD for fairly vague symptoms before they seek medical advice. Therefore, it is important to determine the time that the serologic tests remain predictive of the disease after the introduction of a GFD.Methods. Sera were taken from 22 consecutively biopsy‐proven adult patients with CD in connection with the diagnostic biopsy. The patients were followed for 1 year and sera were taken after 1, 3, 6 and 12 months after start of a GFD. Sera were stored at −20 °C and analysed for IgA antibodies against gliadin, endomysium and two different commercial tTG assays based on recombinant human tTG (tTGrh) and guinea‐pig liver (tTGgp).Results. Twenty patients could be followed during GFD and all antibody titres fell sharply within 1 month after introduction of a GFD and continued to decline during the survey interval. Thirty days after beginning the diet only 58, 84, 74 and 53% of all patients had positive antibody levels of tTGrh, tTGgp, EmA and AGA respectively.Conclusions.As the antibodies used to confirm the diagnosis of CD fall rapidly and continue to decline following the introduction of a GFD, it is important that health care providers carefully inquire about the possibility of self‐prescribed diets before patients sought medical attention.
The association between total energy intake and early mortality: data from the Malmö Diet and Cancer Study
Authors: Leosdottir M. , Nilsson P. , Nilsson J.‐Å. , Månsson H. , Berglund G. 
Published: November 2004

Abstract.Objectives.  In animal studies, low energy intake (EI) has been associated with a longer lifespan. We examine whether EI is an independent risk factor for prospective all‐cause mortality, cardiovascular and cancer mortality in humans.Design.  Population‐based, prospective cohort study.Setting and subjects.  The Malmö Diet and Cancer Study is a population‐based prospective cohort study. A total of 28 098 individuals, mean age 58.2 years, completed questionnaires on diet and life‐style and attended a physical examination during 1991–96.Main outcome measures.  Information on mortality was acquired from national registries during a mean follow‐up time of 6.6 years. Subjects were categorized by quartiles of total EI. The first quartile was used as a reference point in estimating multivariate relative risks (RR; 95% CI, Cox's regression model). Adjustments were made for confounding by age and various life‐style factors.Results.  The lowest total mortality was observed for women in the third quartile (RR: 0.74; CI: 0.57–0.96) and for men in the second and third quartiles (RR: 0.85; CI: 0.69–1.04 and RR: 0.85; CI: 0.69–1.04 respectively). Similar U‐shaped patterns were observed for cardiovascular mortality amongst women and cancer mortality amongst men. A statistically significant trend (P = 0.029) towards lower cardiovascular mortality from the first to the fourth quartile was observed for men.Conclusions.  Low caloric consumers did, on average, not have lower mortality than average or high caloric consumers. Generally, individuals approximately meeting national recommendations for total EI had the lowest mortality. For men, high caloric intake was associated with lower cardiovascular mortality.
A Pseudomonas aeruginosa quorum‐sensing molecule influences Candida albicans morphology
Authors: Hogan Deborah A. , Vik Åshild , Kolter Roberto 
Published: November 2004

Summary Candida albicans is an opportunistic pathogen that is commonly found as a member of the human microflora. The ability of C. albicans to alter its cellular morphology has been associated with its virulence; yeast cells are more prevalent in commensal interactions whereas filamentous cells appear important in opportunistic infections. C. albicans encounters a multitude of other microbial species in the host environment and it is likely that they impact the C. albicans transition between virulent and non‐virulent states. Here, we report that C. albicans morphology is significantly affected by the presence of Pseudomonas aeruginosa, another opportunistic pathogen. In a screen using a C. albicans HWP1–lacZ strain to indicate regions of filamentous growth, we identified P. aeruginosa mutants incapable of inhibiting C. albicans filamentation. Through these studies, we found that 3‐oxo‐C12 homoserine lactone, a cell–cell signalling molecule produced by P. aeruginosa, was sufficient to inhibit C. albicans filamentation without affecting fungal growth rates. Both microscopic analysis and real‐time reverse transcription polymerase chain reaction analysis of morphology‐specific markers confirmed that filamentation was suppressed by 200 µM 3‐oxo‐C12 homoserine lactone. Structurally related compounds with a 12‐carbon chain length, e.g. C12‐acyl homoserine lactone and dodecanol also affected C. albicans filamentation at similar concentrations. In contrast, other acylated homoserine lactones of different chain lengths did not affect fungal morphology. The activity of 3OC12HSL is compared with that of farnesol, a C. albicans‐produced molecule also with a C12‐backbone. The effects that bacteria have on the morphology of C. albicans represents one of the ways by which bacteria can influence the behaviour of fungal cells.
The ATP‐dependent ClpXP and Lon proteases regulate expression of the Yersinia pestis type III secretion system via regulated proteolysis of YmoA, a small histone‐like protein
Authors: Jackson Michael W. , Silva‐Herzog Eugenia , Plano Gregory V. 
Published: November 2004

SummaryThe Yersinia pestis plasmid pCD1‐encoded type III secretion system (T3SS) is essential for the pathogenicity of Y. pestis in mammalian hosts. T3SS‐associated genes are maximally expressed at 37°C in the absence of extracellular calcium. Expression of T3SS genes requires LcrF, an AraC‐like transcriptional activator, and is repressed by YmoA, a small histone‐like protein. The mechanism by which temperature regulates T3SS gene expression has not been determined; however, changes in DNA topology have been implicated in this process. We report here that a Y. pestis strain deficient in production of the ClpXP and Lon proteases does not express a functional T3SS partly because of high cytosolic levels of YmoA. YmoA is rapidly degraded at 37°C in wild‐type Y. pestis, but remains stable in a clpXPlon deletion mutant. The stability of YmoA in wild‐type Y. pestis increased as the growth temperature of the culture decreased; in contrast, YmoA was stable at all temperatures examined in the clpXPlon deletion mutant. These results indicate that the ClpXP and Lon proteases contribute to the environmental regulation of the Y. pestis T3SS system through regulated proteolysis of YmoA.
A potential role for ICP, a leishmanial inhibitor of cysteine peptidases, in the interaction between host and parasite
Authors: Besteiro Sébastien , Coombs Graham H. , Mottram Jeremy C. 
Published: November 2004

SummaryThe biological role of a natural inhibitor of cysteine peptidases (designated ICP) of Leishmania has been investigated by genetic manipulation of the parasite. Null mutants grew normally in vitro, were as infective to macrophages in vitro as wild‐type parasites, but had reduced infectivity to mice. Mutants re‐expressing ICP from a single gene gave partial restoration of virulence in vivo, whereas mutants overexpressing ICP secreted the inhibitor and showed markedly reduced virulence in mice. Promastigotes of the null mutants had similar cysteine peptidase activities as the wild‐type parasites, suggesting that ICP is not required for the expression or processing of the enzymes. The only proteins found to bind to ICP in promastigote cell lysates were fully processed forms of CPA and CPB, showing that ICP does not bind in abundance either to zymogens of the cysteine peptidases or other leishmanial proteins. However, only a small proportion of ICP colocalized with CPA and CPB in the promastigote (in the endoplasmic reticulum and Golgi) and the majority of ICP resided in vesicles that are apparently distinct from endosomes and the multivesicular tubule (MVT)‐lysosome. These data suggest that ICP has a role other than modulation of the activity of the parasite’s own cysteine peptidases and their normal trafficking to the MVT‐lysosome via the flagellar pocket. The finding that ICP partially colocalized with an endocytosed cysteine peptidase leads us to postulate that ICP has a role in protection of the parasite against the hydrolytic environment of the sandfly gut and/or the parasitophorous vacuole of host macrophages.
The RNase E of Escherichia coli has at least two binding sites for DEAD‐box RNA helicases: functional replacement of RhlB by RhlE
Authors: Khemici Vanessa , Toesca Isabelle , Poljak Leonora , Vanzo Nathalie F. , Carpousis Agamemnon J. 
Published: November 2004

SummaryThe non‐catalytic region of Escherichia coli RNase E contains a protein scaffold that binds to the other components of the RNA degradosome. Alanine scanning yielded a mutation, R730A, that disrupts the interaction between RNase E and the DEAD‐box RNA helicase, RhlB. We show that three other DEAD‐box helicases, SrmB, RhlE and CsdA also bind to RNase E in vitro. Their binding differs from that of RhlB because it is not affected by the R730A mutation. Furthermore, the deletion of residues 791–843, which does not affect RhlB binding, disrupts the binding of SrmB, RhlE and CsdA. Therefore, RNase E has at least two RNA helicase binding sites. Reconstitution of a complex containing the protein scaffold of RNase E, PNPase and RhlE shows that RhlE can furnish an ATP‐dependent activity that facilitates the degradation of structured RNA by PNPase. Thus, RhlE can replace the function of RhlB in vitro. The results in the accompanying article show that CsdA can also replace RhlB in vitro. Thus, RhlB, RhlE and CsdA are interchangeable in in vitro RNA degradation assays.
Identification of a polar targeting determinant for Bacillus subtilis DivIVA
Authors: Perry S. E. , Edwards D. H. 
Published: November 2004

SummaryThe Bacillus subtilis protein DivIVA controls both the positioning of the vegetative cell division site and the polar attachment of the chromosome during sporulation. In vegetative growth DivIVA attracts the bipartite cell division inhibitor MinCD away from the cell centre and towards the cell pole. This process ensures the inactivation of old polar division sites and leaves the cell centre free for the assembly of a new cell division complex. During sporulation MinCD and DivIVA levels fall, but DivIVA remains at the cell poles and becomes involved in the migration of the chromosomes to the pole. In order to investigate polar targeting of DivIVA, we undertook a mutational analysis of the 164‐amino‐acid protein. These studies identified one mutant (divIVAR18C) that could not localize to the cell pole but which retained the ability to support both vegetative growth and 50% sporulation efficiency. Further analysis revealed that, in the absence of polar targeting, DivIVAR18C localized to the nucleoid during vegetative growth in a Spo0J/Soj‐dependent manner and required Spo0J/Soj and MinD to orientate the chromosomes correctly during sporulation. We demonstrate that polar targeting of DivIVAR18C is not essential during vegetative growth because the mutant can recognize the cell division site and influences the localization of MinD. Similarly we show that DivIVAR18C can function during sporulation because it can support the Spo0J/Soj orientation of the chromosome. In addition, we establish that both residues 18 and 19 constitute a DivIVA polar targeting determinant.
Clp ATPases are required for stress tolerance, intracellular replication and biofilm formation in Staphylococcus aureus
Authors: Frees Dorte , Chastanet Arnaud , Qazi Saara , Sørensen Karen , Hill Philip , Msadek Tarek , Ingmer Hanne 
Published: November 2004

SummaryThe Hsp100/Clp ATPases constitute a family of closely related proteins of which some members function solely as chaperones whereas others additionally can associate with the unrelated ClpP peptidase forming a Clp proteolytic complex. We have investigated the role of four Clp ATPases in the versatile pathogen, Staphylococcus aureus. Previously, we showed that ClpX is required for expression of major virulence factors and for virulence of S. aureus, but not for survival during heat shock. In the present study, we have inactivated clpC, clpB and clpL and, while none of these mutations affected toxin production, both ClpC and ClpB and to a minor extent ClpL were required for intracellular multiplication within bovine mammary epithelial cells. These defects were paralleled by an inability of the clpC mutant to grow at high temperature and of the clpB mutant to induce thermotolerance indicating that the protective functions of these proteins are required both at high temperature and during infection. By primer extension analysis and footprint studies, we show that expression of clpC and clpB is controlled by the negative heat‐shock regulator, CtsR, and that ClpC is required for its repressor activity. Thus, ClpC is a likely sensor of stress encountered during both environmental stress and infection. In addition to virulence factor production the ability to form biofilms is of importance to S. aureus as a nosocomial pathogen. Interestingly, biofilm formation was reduced in the absence of ClpX or ClpC whereas it was enhanced in the absence of ClpP. Thus, our data show that Clp proteolytic complexes and the Clp ATPases control several key processes of importance to the success of S. aureus as a pathogen.
Negative chronotropic response to adenosine receptor stimulation in rat right atria after run training
Authors: Priviero Fernanda , De Nucci Gilberto , Antunes Edson , Zanesco Angelina 
Published: November 2004

Summary1. The aim of the present study was to evaluate the potency and maximal responses (Emax) to the adenosine receptor agonists N6‐cyclopentyladenosine (CPA), N‐ethylcarboxamidoadenosine (NECA) and N6‐(3‐iodobenzyl)‐5′‐N‐methylcarbaxamidoadenosine (IB‐MECA) in right atria from trained rats. We also investigated the interaction between the training bradycardia and the sensitivity of the chronotropic response mediated by adenosine receptor stimulation.2. Animals were submitted to run training for 60 min, 5 days a week, over a period of 8 weeks. Mean blood pressure and heart rate were measured in conscious animals. Right atria were isolated and concentration–response curves to CPA, NECA and IB‐MECA were obtained.3. A reduction in heart rate was found in trained rats, indicating that the training programme was successful in inducing physical conditioning. The three adenosine receptor agonists induced a concentration‐dependent negative chronotropic response. The rank order of potency and Emax for the three adenosine receptor agonists was CPA > NECA > IB‐MECA.4. Dynamic exercise for 8 weeks did not alter the Emax for CPA, NECA and IB‐MECA. Similarly, the potencies of CPA and NECA were not affected by run training, whereas the potency of IB‐MECA was reduced (6.10 ± 0.09 vs 5.66 ± 0.10 for sedentary and trained groups, respectively).5. In conclusion, run training for 8 weeks induced a desensitization of the chronotropic response to IB‐MECA without changing the potency of CPA and NECA. These findings exclude the participation of adenosine receptors in the training bradycardia.
High‐salt diet and responses of the pressurized mesenteric artery of the dog to noradrenaline and acetylcholine
Authors: Sofola OA , Knill A , Myers D , Hainsworth R , Drinkhill MJ 
Published: November 2004

Summary1. A high‐salt diet in rats has been shown to result in enhanced vasoconstrictor and/or reduced vasodilator responses of isolated arteries to agonists. The present experiments were designed to investigate the effects of dietary salt on the responses of the pressurized mesenteric resistance artery of the dog to constrictor and dilator agents.2. Dogs were fed diets containing three different levels of salt with sodium concentrations (in mmol/kg per day) of 0.4 (low salt; LS), 3.0 (intermediate salt; IS) and 6.0 (high salt; HS) for a period of 4 weeks. At the end of the feeding period, animals were killed and lengths of third‐order mesenteric artery were obtained and mounted in a perfusion myograph and changes in internal diameter were measured using a microscope and video‐tracking device. The responses to noradrenaline (NA), acetylcholine (ACh) and sodium nitroprusside (SNP) were then determined.3. The vasoconstrictor responses to NA were identical in the three groups. However, the relaxation response of the vessels to ACh was attenuated in HS dogs compared with LS dogs (P < 0.05), but not with IS dogs. The application of NG‐nitro‐l‐arginine methyl ester, an inhibitor of nitric oxide synthase, reduced the relaxation responses to ACh comparably in all three groups. The relaxation responses of the vessels to SNP were similar in all groups.4. These results indicate that, in the dog mesenteric resistance artery, a high‐salt diet does not affect vasoconstrictor responses to NA, but does attenuate the vasorelaxant action of ACh, largely by inhibiting the production of endothelium‐derived relaxing factor.
Upregulation of Fas/Fas ligand‐mediated apoptosis by gossypol in an immortalized human alveolar lung cancer cell line
Authors: Chang Jung‐San , Hsu Ya‐Ling , Kuo Po‐Lin , Chiang Lien‐Chai , Lin Chun‐Ching 
Published: November 2004

Summary1. Gossypol has wide antineoplastic effects in vitro, but its effects on human lung cancer have not been explored.2. To evaluate the activity of gossypol against alveolar cell lung cancer and to provide information on the mechanism of action, we examined the effects of gossypol on the proliferation of A549 cells indirectly using an XTT assay and on the distribution of cells within the phases of the cell cycle using flow cytometry. We also examined several factors that may affect apoptosis, including p53, p21/WAF1, Fas receptor, Fas ligand (FasL) and caspase 8 activity.3. The results showed that gossypol inhibited proliferation of A549 cells at a concentration of 0.5 µmol/L after 12 h treatment. The effect was both dose‐ and time‐dependent by the induction of apoptosis without the effect of p53 and p21/WAF1.4. Upregulation of Fas/FasL, in association with the activation of downstream caspase 8 activity, was observed following treatment with gossypol. The Fas/FasL pathway accounted for 75% of gossypol‐mediated apoptosis.5. We suggest that the Fas/FasL apoptotic system is the major pathway for gossypol‐mediated apoptosis of A549 cells.6. Gossypol had no effect on the distribution of A549 cells within the phases of the cell cycle.7. In conclusion, gossypol inhibited A549 cells mainly by induction of the Fas/FasL apoptotic pathway, but not the p53 and p21/WAF1 pathway.