bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compound heterozygosity of novel missense mutations in the gamma-glutamyl-carboxylase gene causes hereditary combined vitamin K–dependent coagulation factor deficiency
Authors: Darghouth Dhouha , Hallgren Kevin W. , Shtofman Rebecca L. , Mrad Amel , Gharbi Youssef , Maherzi Ahmed , Kastally Radhia , LeRicousse Sophie , Berkner Kathleen L. , Rosa Jean-Philippe 
Published: May 2006

AbstractHereditary combined vitamin K–dependent (VKD) coagulation factor deficiency is an autosomal recessive bleeding disorder associated with defects in either the γ-carboxylase, which carboxylates VKD proteins to render them active, or the vitamin K epoxide reductase (VKORC1), which supplies the reduced vitamin K cofactor required for carboxylation. Such deficiencies are rare, and we report the fourth case resulting from mutations in the carboxylase gene, identified in a Tunisian girl who exhibited impaired function in hemostatic VKD factors that was not restored by vitamin K administration. Sequence analysis of the proposita did not identify any mutations in the VKORC1 gene but, remarkably, revealed 3 heterozygous mutations in the carboxylase gene that caused the substitutions Asp31Asn, Trp157Arg, and Thr591Lys. None of these mutations have previously been reported. Family analysis showed that Asp31Asn and Thr591Lys were coallelic and maternally transmitted while Trp157Arg was transmitted by the father, and a genomic screen of 100 healthy individuals ruled out frequent polymorphisms. Mutational analysis indicated wild-type activity for the Asp31Asn carboxylase. In contrast, the respective Trp157Arg and Thr591Lys activities were 8% and 0% that of wild-type carboxylase, and their compound heterozygosity can therefore account for functional VKD factor deficiency. The implications for carboxylase mechanism are discussed.
Impaired “outside-in” integrin αIIbβ3 signaling and thrombus stability in TSSC6-deficient mice
Authors: Goschnick Matt W. , Lau Lai-Man , Wee Janet L. , Liu Yong S. , Hogarth P. Mark , Robb Lorraine M. , Hickey Michael J. , Wright Mark D. , Jackson Denise E. 
Published: May 2006

AbstractWe investigated the role of the hematopoietic-specific tetraspanin superfamily member, TSSC6, in platelet function using wild-type mice and TSSC6-deficient mice. TSSC6 is expressed on the surface of murine platelets and is up-regulated by thrombin stimulation, indicating an intracellular pool of TSSC6. Immunoprecipitation/Western blot studies reveal a constitutive physical association of TSSC6 with the integrin αIIbβ3 complex under strong detergent conditions. In vivo evaluation of hemostasis by tail bleeding revealed increased bleeding time, volume of blood lost, and evidence of tail rebleeds in TSSC6 null mice, indicating unstable hemostasis. Using ex vivo techniques, we showed that TSSC6-deficient platelets exhibited impaired kinetics of clot retraction, platelet aggregation at lower doses of PAR-4, and collagen and platelet spreading on fibrinogen in the presence of normal integrin αIIbβ3 expression. TSSC6-deficient platelets showed normal alpha granule secretion, normal “insideout” integrin αIIbβ3 signaling (fluorescein isothiocyanate [FITC]–fibrinogen and JON/A binding), and normal platelet adhesion on fibrinogen. Furthermore, we show that absence of platelet TSSC6 affects the secondary stability of arterial thrombi in vivo upon vascular injury. These data demonstrate that TSSC6 appears to regulate integrin αIIbβ3 “outside-in” signaling events in platelets and is necessary for stability of arterial thrombi in vivo.
Impaired megakaryocytopoiesis in type 2B von Willebrand disease with severe thrombocytopenia
Authors: Nurden Paquita , Debili Najet , Vainchenker William , Bobe Regis , Bredoux Raymonde , Corvazier Elisabeth , Combrie Robert , Fressinaud Edith , Meyer Dominique , Nurden Alan T. , Enouf Jocelyne 
Published: May 2006

AbstractIn type 2B von Willebrand disease, there is spontaneous binding of mutated von Willebrand factor (VWF) multimers to platelets. Here we report a family in which severe thrombocytopenia may also be linked to abnormal megakaryocytopoiesis. A heterozygous mutation in the VWF A1 domain gave a R1308P substitution in an interactive site for glycoprotein Ibα (GPIbα). Electron microscopy showed clusters of platelets in close contact. Binding of antibodies to the GPIbα N-terminal domain was decreased, whereas GPIX and GPV were normally detected. In Western blotting (WB), GPIbα, αIIb, and β3 were normally present. Proteins involved in Ca2+ homeostasis were analyzed by quantitating platelet mRNA or by WB. Plasma membrane Ca2+ ATPase (PMCA)-4b and type III inositol trisphosphate receptor (InsP3-R3) were selectively increased. The presence of degradation products of polyadenosine diphosphate (ADP)-ribose polymerase protein (PARP) suggested ongoing caspase-3 activity. These were findings typical of immature normal megakaryocytes cultured from peripheral blood CD34+ cells with TPO. Significantly, megakaryocytes from the patients in culture produced self-associated and interwoven proplatelets. Immunolocalization showed VWF not only associated with platelets, but already on the megakaryocyte surface and within internal channels. In this family, type 2B VWD is clearly associated with abnormal platelet production.
Thrombin-induced endothelial microparticle generation: identification of a novel pathway involving ROCK-II activation by caspase-2
Authors: Sapet Cédric , Simoncini Stéphanie , Loriod Béatrice , Puthier Denis , Sampol José , Nguyen Catherine , Dignat-George Françoise , Anfosso Francine 
Published: May 2006

AbstractThrombin exerts pleiotropic effects on endothelial cells, including the release of microparticles (EMPs) that disseminate and exchange information with vascular cells. Nevertheless, the mechanisms leading to their generation are not elucidated. We performed microarray analysis to identify genes involved in EMP release by the endothelial cell line HMEC-1 in response to thrombin. We identified a group of genes linked to the cytoskeleton reorganization family. Among these, the Rho-kinase ROCK-II presented a high transcription rate. ROCK-I, another Rho-kinase isoform, was not modulated by thrombin. Pharmacologic inhibition of Rho-kinases or specific depletion of ROCK-II by short interfering (si) RNA inhibited thrombin-induced EMP release. In contrast, ROCK-I mRNA silencing did not modify EMP generation by thrombin. Exposure of HMEC-1 to thrombin in presence of the caspase-2 selective inhibitor Z-VDVAD-FMK prevented ROCK-II cleavage and inhibited the thrombin-induced EMP release. These events were observed in absence of cell death. Our data clearly identified ROCK-II as a target of thrombin in EMP generation. They indicated that the 2 Rho-kinases did not share identical functions. The involvement of caspase-2 in ROCK-II activation independently of cell death points out a novel signaling pathway that emphasizes the proteolytic activity of caspase in EMP generation in response to cell activation.
Evaluation of the safety and pharmacodynamics of Hematide, a novel erythropoietic agent, in a phase 1, double-blind, placebo-controlled, dose-escalation study in healthy volunteers
Authors: Stead Richard B. , Lambert John , Wessels Dawie , Iwashita Julie S. , Leuther Kerstin K. , Woodburn Kathryn W. , Schatz Peter J. , Okamoto Douglas M. , Naso Robert , Duliege Anne-Marie 
Published: May 2006

AbstractHematide is an investigational pegylated synthetic peptide that stimulates erythropoiesis in animal models and is being developed for the treatment of anemia associated with chronic renal failure and cancer. This study evaluated the safety and pharmacodynamics of single, intravenous doses (0.025, 0.05, and 0.1 mg/kg) of Hematide in 28 healthy male volunteers. All doses of Hematide were well tolerated, with safety profiles similar to those of placebo. Hematide showed a dose-dependent increase in reticulocytes. The 0.1-mg/kg dose was associated with a statistically significant increase in hemoglobin (Hgb) from baseline compared to the placebo group (13.6 ± 3.9 g/L [1.36 ± 0.39 g/dL] versus 3.9 ± 3.8 g/L [0.39 ± 0.38 g/dL]; P < .001) that was sustained for longer than 1 month. These results support phase 2 studies in patients with anemia associated with chronic kidney disease or cancer and suggest that Hematide administered as infrequently as once a month may result in a sustained elevation of Hgb levels. (Please note that Hematide is a proposed trade name; the compound does not yet have a nonproprietary name.)
Identification of a Bacillus thuringiensis Cry11Ba toxin-binding aminopeptidase from the mosquito, Anopheles quadrimaculatus
Authors: Abdullah Mohd Amir F , Valaitis Algimantas P , Dean Donald H 
Published: May 2006

Abstract

Background
Aminopeptidase N (APN) type proteins isolated from several species of lepidopteran insects have been implicated as Bacillus thuringiensis (Bt) toxin-binding proteins (receptors) for Cry toxins. We examined brush border membrane vesicle (BBMV) proteins from the mosquito Anopheles quadrimaculatus to determine if APNs from this organism would bind mosquitocidal Cry toxins that are active to it.

Results
A 100-kDa protein with APN activity (APNAnq 100) was isolated from the brush border membrane of Anopheles quadrimaculatus. Native state binding analysis by surface plasmon resonance shows that APNAnq 100 forms tight binding to a mosquitocidal Bt toxin, Cry11Ba, but not to Cry2Aa, Cry4Ba or Cry11Aa.

Conclusion
An aminopeptidase from Anopheles quadrimaculatus mosquitoes is a specific binding protein for Bacillus thuringiensis Cry11Ba.
Expression of carbonic anhydrases IX and XII during mouse embryonic development
Authors: Kallio Heini , Pastorekova Silvia , Pastorek Jaromir , Waheed Abdul , Sly William S , Mannisto Susanna , Heikinheimo Markku , Parkkila Seppo 
Published: May 2006

Abstract

Background
Of the thirteen active carbonic anhydrase (CA) isozymes, CA IX and XII have been linked to carcinogenesis. It has been suggested that these membrane-bound CAs participate in cancer cell invasion, which is facilitated by an acidic tumor cell environment. Since active cell migration is a characteristic feature of embryonic development, we set out to explore whether these isozymes are expressed in mouse embryos of different ages. The studies were focused on organogenesis stage.

Results
Immunohistochemistry demonstrated that both CA IX and XII are present in several tissues of the developing mouse embryo during organogenesis. Staining for CA IX revealed a relatively wide distribution pattern with moderate signals in the brain, lung, pancreas and liver and weak signals in the kidney and stomach. The expression pattern of CA XII in the embryonic tissues was also relatively broad, although the intensity of immunostaining was weak in most tissues. The CA XII-positive tissues included the brain, where the most prominent staining was seen in the choroid plexus, and the stomach, pancreas, liver and kidney.

Conclusion
Membrane-bound CA isozymes IX and XII are expressed in various tissues during mouse organogenesis. These enzymes may regulate ion and pH homeostasis within the developing embryo.
Comparative genomic mapping of the bovine Fragile Histidine Triad (FHIT) tumour suppressor gene: characterization of a 2 Mb BAC contig covering the locus, complete annotation of the gene, analysis of cDNA and of physiological expression profiles
Authors: Uboldi Cristina , Guidi Elena , Roperto Sante , Russo Valeria , Roperto Franco , Di Meo Giulia Pia , Iannuzzi Leopoldo , Floriot Sandrine , Boussaha Mekki , Eggen André , Ferretti Luca 
Published: May 2006

Abstract

Background
The Fragile Histidine Triad gene (FHIT) is an oncosuppressor implicated in many human cancers, including vesical tumors. FHIT is frequently hit by deletions caused by fragility at FRA3B, the most active of human common fragile sites, where FHIT lays. Vesical tumors affect also cattle, including animals grazing in the wild on bracken fern; compounds released by the fern are known to induce chromosome fragility and may trigger cancer with the interplay of latent Papilloma virus.

Results
The bovine FHIT was characterized by assembling a contig of 78 BACs. Sequence tags were designed on human exons and introns and used directly to select bovine BACs, or compared with sequence data in the bovine genome database or in the trace archive of the bovine genome sequencing project, and adapted before use. FHIT is split in ten exons like in man, with exons 5 to 9 coding for a 149 amino acids protein. VISTA global alignments between bovine genomic contigs retrieved from the bovine genome database and the human FHIT region were performed. Conservation was extremely high over a 2 Mb region spanning the whole FHIT locus, including the size of introns. Thus, the bovine FHIT covers about 1.6 Mb compared to 1.5 Mb in man. Expression was analyzed by RT-PCR and Northern blot, and was found to be ubiquitous. Four cDNA isoforms were isolated and sequenced, that originate from an alternative usage of three variants of exon 4, revealing a size very close to the major human FHIT cDNAs.

Conclusion
A comparative genomic approach allowed to assemble a contig of 78 BACs and to completely annotate a 1.6 Mb region spanning the bovine FHIT gene. The findings confirmed the very high level of conservation between human and bovine genomes and the importance of comparative mapping to speed the annotation process of the recently sequenced bovine genome. The detailed knowledge of the genomic FHIT region will allow to study the role of FHIT in bovine cancerogenesis, especially of vesical papillomavirus-associated cancers of the urinary bladder, and will be the basis to define the molecular structure of the bovine homologue of FRA3B, the major common fragile site of the human genome.
Causal inference of regulator-target pairs by gene mapping of expression phenotypes
Authors: Kulp David C , Jagalur Manjunatha 
Published: May 2006

Abstract

Background
Correlations between polymorphic markers and observed phenotypes provide the basis for mapping traits in quantitative genetics. When the phenotype is gene expression, then loci involved in regulatory control can theoretically be implicated. Recent efforts to construct gene regulatory networks from genotype and gene expression data have shown that biologically relevant networks can be achieved from an integrative approach. In this paper, we consider the problem of identifying individual pairs of genes in a direct or indirect, causal, trans-acting relationship.

Results
Inspired by epistatic models of multi-locus quantitative trait (QTL) mapping, we propose a unified model of expression and genotype to identify quantitative trait genes (QTG) by extending the conventional linear model to include both genotype and expression of regulator genes and their interactions. The model provides mapping of specific genes in contrast to standard linkage approaches that implicate large QTL intervals typically containing tens of genes. In simulations, we found that the method can often detect weak trans-acting regulators amid the background noise of thousands of traits and is robust to transcription models containing multiple regulator genes. We reanalyze several pleiotropic loci derived from a large set of yeast matings and identify a likely alternative regulator not previously published. However, we also found that many regulators can not be so easily mapped due to the presence of cis-acting QTLs on the regulators, which induce close linkage among small neighborhoods of genes. QTG mapped regulator-target pairs linked to ARN1 were combined to form a regulatory module, which we observed to be highly enriched in iron homeostasis related genes and contained several causally directed links that had not been identified in other automatic reconstructions of that regulatory module. Finally, we also confirm the surprising, previously published results that regulators controlling gene expression are not enriched for transcription factors, but we do show that our more precise mapping model reveals functional enrichment for several other biological processes related to the regulation of the cell.

Conclusion
By incorporating interacting expression and genotype, our QTG mapping method can identify specific regulator genes in contrast to standard QTL interval mapping. We have shown that the method can recover biologically significant regulator-target pairs and the approach leads to a general framework for inducing a regulatory module network topology of directed and undirected edges that can be used to identify leads in pathway analysis.
No direct effect of the -521 C/T polymorphism in the human dopamine D4 receptor gene promoter on transcriptional activity
Authors: Kereszturi Eva , Kiraly Orsolya , Barta Csaba , Molnar Noemi , Sasvari-Szekely Maria , Csapo Zsolt 
Published: May 2006

Abstract

Background
The human dopamine D4 receptor (DRD4) gene has been studied extensively as a candidate gene for certain psychological traits and several behavioural and psychiatric disorders. Both the 5' regulatory region and the coding sequence contain a number of polymorphisms. The promoter variants have received particular attention in the past few years due to their possible role in the regulation of gene transcription. Previously, the -521C/T SNP was shown to influence promoter activity. The aim of this study is to perform an in-depth analysis of this effect in the context of various neural cell lines.

Results
Endogenous mRNA expression of the DRD4 gene was demonstrated in two neuroblastoma (SK-N-F1, IMR32) and one retinoblastoma cell line (Y79) by RT-PCR. In addition, very low DRD4 mRNA levels were also detected in HeLa cells. The transcriptional activity of a series of 5' promoter deletion mutants was determined by transient transfection of luciferase reporter constructs. The activity profile of these promoter fragments was similar in each of the cell lines tested. The highest luciferase reporter activity was obtained with a construct containing promoter sequences between nucleotides -668 to -389, while a putative silencer region was localised spanning from nucleotide -1571 to -800. Surprisingly, the -521 C/T polymorphism had no significant effect on transcriptional activity of the reporter construct with the highest activity (-668 to -389) in any of the three cell lines tested.

Conclusion
Our results do not confirm previous data assigning different transcriptional activities to the -521 C/T alleles of the human DRD4 promoter. Furthermore, these findings highlight the need for further characterization of the 5' regulatory region of the DRD4 gene and identification of additional functional promoter polymorphic sites, especially in the context of haplotype.
An exploratory study of GP awareness of carer emotional needs in Western Australia
Authors: Bulsara Caroline E , Fynn Noreen 
Published: May 2006

Abstract

Background
The impact of caring for a family member or friend is a life changing experience. Often carers are struggling to cope with ongoing demands of caring for someone. At some point, most carers will approach their family physician for advice on aspects of their role. Carers Western Australia sought information and opinions of General Practitioners (GPs) regarding being a carer. This exploratory survey was to assess the perceptions of Western Australian GPs regarding their role in providing information and support to carers and their awareness of carer needs and issues.

Methods
A telephone survey design of an opportunistic sample of 66 Western Australian GPs was conducted. The responses were both closed and open-ended questions to allow for probing of responses. Responses were analysed using both qualitative and quantitative analysis.

Results
GPs are generally aware of their role in regard to carers and most doctors (88%) said that they had been approached for help in accessing services by carers. A majority of respondents said that carers and spoken to them (70%) and asked for help with (77%) emotional needs. However, when asked how these needs are met, GPs tended to provide practical assistance for the care recipient and carer as a means of addressing those needs. This primarily included providing referral to services to ensure that the carer has practical assistance in caring for the person. However, GPs are less able to provide the necessary emotional or psychological support needed by carers before crisis point is reached. Most doctors said that they had experienced difficulties in providing assistance to carers (84%) at some time.

Conclusion
GPs may be unable or unwilling to provide the necessary assistance to carers who are showing signs of carer burnout and stress. The GP needs to adopt a more holistic approach when treating a patient as to the interaction with the caregiver.
Recurrent bacteremia with Helicobacter cinaedi: case report and review of the literature
Authors: Uçkay Ilker , Garbino Jorge , Dietrich Pierre-Yves , Ninet Béatrice , Rohner Peter , Jacomo Véronique 
Published: May 2006

Abstract

Background

Helicobacter cinaedi is a rare pathogen in humans, occurring mostly in immuno-compromised patients, with a high potential for recurrence. We describe a case of a patient with lymphoma hospitalized for chemotherapy.

Case presentation
At admission, the patient presented with an indolent and non-prurigenic macular rash around her implantable venous access device. Gram staining of blood cultures revealed the presence of spiral-shaped gram-negative rods that could not be grown upon subculture. Helicobacter cinaedi was identified by PCR. No other symptoms or pathology were observed in a whole body CT scan. The implantable venous access device was removed and empiric therapy by ceftriaxone and gentamicin for 2 weeks was initiated, followed by peroral clarithromycin 2 × 500 mg/day and later by levofloxacin 2 × 500 mg/day for 7 weeks. Oncologic remission was achieved 3 months later. However, the patient was re-hospitalized 2 months later for fever, shivering, reappearance of the macular non-prurigenic rash, diarrhea, cough and asthenia. Blood cultures grew H. cinaedi. Multiple investigations could not identify the source. Empiric antibiotic therapy of ceftriaxone and doxycycline was started for 2 weeks with resolution of symptoms, followed by an oral combination of amoxicillin, metronidazole and doxycycline for 2 months; doxycycline was continued for another month. Bacteremia has not recurred for a period of 19 months.

Conclusion
Although H. cinaedi is considered to be a low virulent bacteria, its potential to cause recurrent bacteremia should not be underestimated. H. cinaedi could have an endovascular source of infection and should be treated for an adequate duration with combined antibiotherapy.