3,767 research outputs found
Reconciling and translating migration data collected over time intervals of different widths
No full textIn this paper we describe and contrast the age and spatial structures of migration identified by data collected over one-year and five-year time intervals, by focusing, in particular, on the generation and distribution components of age- and origin-destination-specific migration flows. We explore the contributions of primary, return, and onward migration defined by fixed interval migration data, and we outline a crude translation procedure for transforming the one-year migration flow data into an estimated five-year counterpart. The data used in this study represent several migration periods drawn from recent U.S. and Canadian censuses and surveys. Differences between the structures exhibited by U.S. and Canadian migration patterns, collected over one-year and five-year migration time intervals, are carefully examined and contrasted.
Versions of this paper were presented in February, 2002 at the annual meetings of the Western Regional Science Association in Monterey, California and in May, 2002 at the annual meetings of the Population Association of America in Atlanta, Georgia. The authors would like to thank Professor Frans Willekens at the University of Groningen in the Netherlands for his collaboration on earlier work that focused on migration spatial structure, of which this paper is a continuation. Also, our appreciation goes to the three anonymous reviewers for their comments and suggestions
Evaluating alternatives to the Standardized Mortality Rates
No full textStephen Birch, John Eyles, K. Bruce Newbold
Equitable access to health care
No full textStephen Birch, John Eyles, K. Bruce Newbold. --Bibliography: leaves 29-34
Antigens on the Plasmodium falciparum infected erythrocyte surface are parasite derived: a reply.
No full textIn this article Chris Newbold and Kevin Marsh describe the evidence for the co-existence of both modified host proteins and of parasite determinants at the infected erythrocyte surface. The stable characteristics of infected cells may in part stem from parasite-induced changes in band 3 molecules, thus explaining some of the cytoadherence properties of uninfected, but abnormal cells (as in sickle-cell disease and diabetes). However, Newbold and Marsh suggest that it is difficult to explain the astonishing diversity of antigens that have been observed at the surface of infected red cells unless such molecules have been synthesized by the parasite
Exploring the relationship between mixing, radiation and NOx emissions from natural gas flames
No full textG.J. Nathan, D.S. Nobes, J. Mi, G.M. Schneider, G.J.R. Newbold, Z.T. Alwahabi, R.E. Luxton, K. D. Kinghttp://www.amazon.com/Combustion-emissions-control-III-development/dp/090259755
A well-conserved Plasmodium falciparum var gene shows an unusual stage-specific transcript pattern
No full textThe var multicopy gene family encodes Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variant antigens, which, through their ability to adhere to a variety of host receptors, are thought to be important virulence factors. The predominant expression of a single cytoadherent PfEMP1 type on an infected red blood cell, and the switching between different PfEMP1 types to evade host protective antibody responses, are processes thought to be controlled at the transcriptional level. Contradictory data have been published on the timing of var gene transcription. Reverse transcription-polymerase chain reaction (RT-PCR) data suggested that transcription of the predominant var gene occurs in the later (pigmented trophozoite) stages, whereas Northern blot data indicated such transcripts only in early (ring) stages. We investigated this discrepancy by Northern blot, with probes covering a diverse var gene repertoire. We confirm that almost all var transcript types were detected only in ring stages. However, one type, the well-conserved varCSA transcript, was present constitutively in different laboratory parasites and does not appear to undergo antigenic variation. Although varCSA has been shown to encode a chondroitin sulphate A (CSA)-binding PfEMP1, we find that the presence of full-length varCSA transcripts does not correlate with the CSA-binding phenotype
2019 European Thyroid Association Guidelines for the Treatment and Follow-Up of Advanced Radioiodine-Refractory Thyroid Cancer
No full textThe vast majority of thyroid cancers of follicular origin (TC) have a very favourable outcome, but 5-10% of cases will develop metastatic disease. Around 60-70% of this subset, hence less than 5% of all patients with TC, will become radioiodine refractory (RAI-R), with a significant negative impact on prognosis and a mean life expectancy of 3-5 years. Since no European expert consensus or guidance for this challenging condition is currently available, a task force of TC experts was nominated by the European Thyroid Association (ETA) to prepare this document based on the principles of clinical evidence. The task force started to work in September 2018 and after several revision rounds, prepared a list of recommendations to support the treatment and follow-up of patients with advanced TC. Criteria for advanced RAI-R TC were proposed, and the most appropriate diagnostic tools and the local, systemic and palliative treatments are described. Systemic therapy with multikinase inhibitors is fully discussed, including recommendations on how to start it and at which dosage, on the duration of treatment, and on the management of side effects. The appropriate relationship between the specialist and the patient/family as well as ethical issues are covered. Based on the available studies and on personal experience, the experts provided 39 recommendations aimed to improve the management of advanced RAI-R TCs. Above all of them is the indication to treat and follow these patients in a specialized setting which allows the interaction between several specialists in a multidisciplinary team
Thyroid cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up
No full textThis ESMO Clinical Practice Guidelines provide updated state-of-the-art recommendations on management of thyroid cancer (diagnosis, treatment and follow-up), compiled by a multidisciplinary author panel and accompanied by level of evidence and grade of recommendation, depending on the strength of supporting data and magnitude of benefit from particular intervention
There is no correlation between c-Myc mRNA expression and telomerase activity in human breast cancer
No full textBackground
Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal length and stability thus leading to cellular immortalisation. The hTERT (human telomerase reverse transcriptase) subunit seems to be the rate-limiting determinant of telomerase and knowledge of factors controlling hTERT transcription may be useful in therapeutic strategies. The hTERT promoter contains binding sites for c-Myc and there is experimental and in vitro evidence that c-Myc may increase hTERT expression.
Materials and methods
RNA was extracted from 18 breast carcinomas and c-Myc mRNA expression was estimated by quantitative reverse transcriptase-PCR (RT-PCR) with Taqman methodology. These tumours had already been analysed for ER and PgR status using ligand-binding assays and had had their DNA ploidy and S-phase fractions measured by flow cytometry. Telomerase activity had already been determined by using a modified telomeric repeat and amplification protocol (TRAP) assay.
Results
Telomerase activity ranged from 0 to 246 units of Total Protein Generated (TPG), where one unit of TPG was equal to 600 molecules of telomerase substrate primers extended by at least three telomeric repeats. Median levels of TPG were 60 and mean levels 81. There was no significant correlation between levels of c-Myc mRNA expression, telomerase activity, S phase fraction or PgR. There was a significant negative correlation with ER status.
Conclusion
Although the hTERT promoter contains potential binding sites for c-Myc oncoprotein, we have found no correlation between c-Myc mRNA levels and telomerase activity
The mRNA expression of hTERT in human breast carcinomas correlates with VEGF expression
No full textBackground
Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalisation. hTERT (human telomerase reverse transcriptase) is the rate-limiting determinant of telomerase reactivation. Telomerase has been associated with negative prognostic indicators in some studies. The present study aims to detect any correlation between hTERT and the negative prognostic indicators VEGF and PCNA by quantitatively measuring the mRNA expression of these genes in human breast cancer and in adjacent non-cancerous tissue (ANCT).
Materials and methods
RNA was extracted from 38 breast carcinomas and 40 ANCT. hTERT and VEGF165, VEGF189 and PCNA mRNA expressions were estimated by reverse transcriptase-PCR (RT-PCR) and Taqman methodology.
Results
The level of expression of VEGF-165 and PCNA was significantly higher in carcinoma tissue than ANCT (p = 0.02). The ratio of VEGF165/189 expression was significantly higher in breast carcinoma than ANCT (p = 0.025). hTERT mRNA expression correlated with VEGF-189 mRNA (p = 0.008) and VEGF165 (p = 0.07).
Conclusions
hTERT mRNA expression is associated with the expression of the VEGF189 and 165 isoforms. This could explain the poorer prognosis reported in breast tumours expressing high levels of hTERT. The relative expression of the VEGF isoforms is significantly different in breast tumour to ANCT, and this may be important in breast carcinogenesis
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