1,522 research outputs found

    Functional characterisation of a novel nucleoporin gene NUP98 in zebrafish embryo.

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    Oral PresentationINTRODUCTION: The nucleoporin gene nup98 is important for the regulation of cytoplasmic-nuclear trafficking. Frequent disruptions of NUP98 during chromosomal translocation in acute myeloid leukaemia suggest that it may play a role in normal haematopoiesis. nup98-knockout mice has resulted in early embryonic lethality. Therefore, its role in embryonic haematopoiesis remains unclear. In this study, we have cloned a zebrafish nup98 gene and examined its role in embryonic development, with particular reference to haematopoiesis. METHODS: Two expressed sequence tags with translated sequence homologous to human NUP98 were identified. The gene was cloned by PCR from cDNA of zebrafish embryos. Expression of nup98 in zebrafish embryos was investigated spatially by whole-mount in-situ hybridisation and temporally by RT-PCR. The functions of nup98 were examined by morpholino knockdown and the effects on embryonic development evaluated by gene expression studies and confocal microscopy. Cellular functions of zebrafish nup98 were investigated in HeLa cells. RESULTS: Zebrafish nup98 gene shared 65% identity to human NUP98 homolog in protein sequence. The gene was expressed during early embryonic development since 1-cell stage and diffusely in eyes and the developing brain since 18 hpf. About 30% nup98-knockdown embryos developed intracranial haemorrhage at 48 hpf, resulting from disrupted blood vessels. nup98-knockdown upregulated pu.1 and scl as evaluated by quantitative RT-PCR. Moreover, ectopic expression of zebrafish nup98 rescued the defective mRNA export due to NUP98 knockdown in HeLa cells. CONCLUSION: A novel zebrafish nup98 gene was shown to exhibit conserved function in mRNA trafficking. Its role in embryonic development should be further evaluated.published_or_final_versio

    Methylation of cyclin-dependent kinase inhibitors, XAF1, JUNB, CDH13 and soluble Wnt inhibitors in essential thrombocythaemia

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    Background: Methylation of genes regulating cell-cycle check-point (INK4 cyclin-dependent kinase inhibitors), apoptosis (XAF1), adhesion (CDH13), JUNB and Wnt signalling (soluble Wnt inhibitors) has been implicated in pathogenesis of haematological and epithelial cancers. Method The authors studied the methylation status of CDKN2A, CDKN2B, XAF1, CDH13, JUNB and a panel of soluble Wnt inhibitors including WIF1, DKK3, APC, SFRP1, SFRP2, SFRP4 and SFRP5 by methylation-specific PCR in 31 bone marrow and 21 peripheral blood samples of patients with essential thrombocythaemia. Results and discussion: There was no evidence of hypermethylation of all these genes in both the BM and PB samples. Therefore, in contrast to myeloid leukaemias, methylation of these genes regulating the cell cycle, apoptosis, adhesion and Wnt signalling does not play an important role in the pathogenesis of myeloproliferative diseases. Whether differential methylation may occur in the progenitor or mature blood cell compartments remains to be verified. Our study contributes to the literature on methylation in chronic myeloproliferatve diseases.published_or_final_versio

    Differential NOD/SCID mouse engraftment of peripheral blood CD34 + cells and JAK2V617F clones from patients with myeloproliferative neoplasms

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    We evaluated the NOD/SCID engraftment of CD34 + cells from polycythemia vera (PV) and secondary polycythemia patients (SP) and the JAK2V617F clone before and after transplantation. Peripheral blood CD34 + cells were transplanted intra-femorally. In the injected BM, successful engraftment (>0.1%) occurred in 8/26 mice transplanted with CD34+ cells from 5/13 PV patients (median: 4.26%, range: 0.3-5.56%), in contrast to 0/14 mice from 9 SP patients (P=0.017). The engrafting PV cells were of multi-lineage. JAK2V617F/total JAK2 ratios decreased after transplantation (initial: 65.9% versus 6-week: 13.0%, P=0.001). Essential thrombocythemia (ET) BM cells also exhibited a similar decrease in JAK2V617F clone. The results suggested that events in addition to JAK2V617F are involved in the pathogenesis of PV and ET. © 2010 Elsevier Ltd.postprin

    Ultrafast non-inverting wavelength conversion by cross-absorption modulation in silicon wire waveguides.

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    Abstract We demonstrate all-optical wavelength conversion by means of cross absorption effect induced by Two Photon Absorption (TPA) in submicron sized Si wire waveguides. Optical pulses of 1.6 ps at 1GHz repetition rate were successfully converted from 1550nm to 1532nm. We discuss the performance at higher speed. Our results showed that silicon waveguides have potential applications in high speed photonic signal processing

    Genetic and clinical features of hemoglobin H disease in Chinese patients

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    Background. Normally, one pair of each of the two α-globin genes, α1 and α2, resides on each copy of chromosome 16. In hemoglobin H disease, three of these four α-globin genes are affected by a deletion, a mutation, or both. We studied the α-globin gene abnormalities and the clinical and hematologic features of Chinese patients with hemoglobin H disease in Hong Kong. Methods. We assessed the clinical features, hematologic values, serum ferritin levels, and liver function of 114 patients with hemoglobin H disease. We also performed echocardiography and magnetic resonance imaging of the liver and examined the two pairs of α-globin genes. Results. Hemoglobin H disease in 87 of the 114 patients (76 percent) was due to the deletion of three of the four α-globin genes (--/-α), a combination termed the deletional type of hemoglobin H. The remaining 27 patients (24 percent) had the nondeletional type of hemoglobin H disease, in which two α-globin genes are deleted and a third is mutated (--/αα(T)). All 87 patients with the deletional type of hemoglobin H were double heterozygotes in whom there was a deletion of both α-globin genes from one chromosome, plus a deletion of the α1 or α2 gene from the other chromosome (--/α- or --/-α). A variety of mutated α-globin genes was found in the patients with nondeletional type of hemoglobin H disease. Patients with the nondeletional type of the H disease had more symptoms at a younger age, more severe hemolytic anemia, and larger spleens and were more likely to require transfusions than patients with deletional hemoglobin H disease. The severity of iron overload was not related to the genotype. Conclusions. Chinese patients in Hong Kong with the nondeletional type of hemoglobin H disease have more severe disease than those with the deletional type of the disease. Iron overload is a major cause of disability in both forms of the disease. (C) 2000, Massachusetts Medical Society.published_or_final_versio

    Stage-specific manifestation of mold infections in bone marrow transplant recipients: Risk factors and clinical significance of positive concentrated smears

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    Potassium hydroxide-concentrated smears, prepared from sedimented remains of clinical specimens, were used to distinguish between mold infection and exogenous contamination in fungal culture-positive specimens. This method was applied in the study of 3,857 clinical specimens from 230 bone marrow transplant recipients who were followed up prospectively for infectious complications. Concentrated smears of only 86 (from 21 infected patients) of 149 fungal culture-positive specimens were positive for hyphae; 82 of the strains were Aspergillus species. Concentrated smears of the remaining 63 fungal culture-positive specimens were negative; the strains identified by culture were considered as exogenous contaminants (87% of which were Penicillium species). A stage-specific manifestation of mold infection was observed: 67% of mold infections occurred during acute graft-vs.-host disease (GVHD) a median of 47 days after transplantation, whereas 9% of mold infections occurred as rapidly fatal invasive disease before engraftment. Overall, of the 21 patients with mold infection, 17 (81%) had invasive mold disease, and four (19%) had mold colonization of airways secondary to chronic GVHD after day 100. The significant risk factors for mold infection were total-body irradiation and grade 2-4 acute GVHD. Because of our high mortality rate (82%), the consideration of antimold prophylaxis for such patients may be warranted.published_or_final_versio

    The rise of digital direct-to-consumer advertising?: Comparison of direct-to-consumer advertising expenditure trends from publicly available data sources and global policy implications

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    BACKGROUND: Pharmaceutical marketing is undergoing a major shift in the United States, in part due to new transparency regulations under the healthcare reform act. Changes in pharmaceutical marketing practices include a possible shift from more traditional forms of direct-to-consumer advertising towards emerging use of Internet-based DTCA (“eDTCA”) given the growing importance of digital health or “eHealth.” Though legally allowed only in the U.S. and New Zealand, eDTCA poses novel regulatory challenges, as it can cross geopolitical boundaries and impact health systems and populations outside of these countries. METHODS: We wished to assess whether changes in DTCA and eDTCA expenditure trends was occurring using publicly available pharmaceutical marketing data. DTCA data was analyzed to compare trends in aggregate marketing expenditures and to assess if there were statistically significant differences in trends and magnitudes for data sources and DTCA sub-categories (including eDTCA). This was accomplished using regression lines of DTCA trend data and conducting pairwise comparisons of regression coefficients using t-tests. Means testing was utilized for comparing magnitude of DTCA expenditure. RESULTS: Data from multiple data sources indicate that aggregate DTCA expenditures have slightly declined during the period from 2005–2009 and are consistent with results from other studies. For DTCA sub-categories, television remained the most utilized form of DTCA, though experienced trends of declining expenditures (−13.2 %) similar to other traditional media platforms such as radio (−30.7 %) and outdoor ads (−12.1 %). The only DTCA sub-category that experienced substantial increased expenditures was eDTCA (+109.0 %) and it was the only medium that had statistically significant differences in its marketing expenditure trends compared to other DTCA sub-categories. CONCLUSIONS: Our study indicates that traditional DTCA marketing may be on the decline. Conversely, the only DTCA sub-category that experienced significant increases was eDTCA. However, to fully understand this possible shift to “digital” DTCA, improvements in publicly available DTCA data sources are necessary to confirm changing trends and validate existing data. Hence, utilizing the newly implemented U.S. physician-payment expenditure transparency requirements, we advocate for the mandatory disclosure of DTCA/eDTCA in order to inform future domestic and international health policy efforts regarding appropriate regulation of pharmaceutical promotion

    Observational study of the association of first insulin type in uncontrolled type 2 diabetes with macrovascular and microvascular disease

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    <p>Aims: To compare the risk of vascular disease, HbA1c and weight change, between first prescribed insulins in people with type 2 diabetes.</p> <p>Methods: People included in THIN United Kingdom primary care record database who began insulin (2000–2007) after poor control on oral glucose-lowering agents (OGLD) were grouped by the number of OGLDs in their treatment regimen immediately before starting insulin (n = 3,485). Within OGLD group, Cox regression compared macrovascular (all-cause mortality, myocardial infarction, acute coronary syndrome and stroke) and microvascular disease (peripheral neuropathy, nephropathy, and retinopathy) between insulin type (basal, pre-mix or Neutral Protamine Hagedorn, NPH) while ANCOVAs compared haemoglobin A1c (HbA1c) and weight change.</p> <p>Results: Mean follow-up was 3.6 years. Rates of incident macrovascular events were similar when basal insulin was compared to pre-mix or NPH, adjusted hazard ratio versus basal: pre-mix 1.08 (95% CI 0.73, 1.59); NPH 1.00 (0.63, 1.58) after two OGLDs, and pre-mix 0.97 (0.46, 2.02); NPH 0.77 (0.32, 1.86) after three OGLDs. An increased risk of microvascular disease in NPH versus basal after 3 OGLDs, adjusted hazard ratio1.87 (1.04, 3.36), was not seen after two agents or in comparisons of basal and pre-mix. At one year, after two OGLDs, weight increase was less with basal compared with pre-mix. After three OGLDs, mean HbA1c had reduced less in basal versus pre-mix or NPH at 6–8 and at 9–11 months, and versus pre-mix at 12–14 months.</p> <p>Conclusion: We found no difference in the risk of macrovascular events between first insulins in the medium term when started during poor glycaemia control. The increased risk of microvascular events with NPH warrants further study. In certain groups, first use of basal insulin was associated with less gain in weight and decrease in HbA1c compared to other insulins.</p&gt
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