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Biomedical subjects

E Cameron

Publications and source records attributed to E Cameron.

At least 19 recordsLinked to original sources
PubMed2005

Endoscopy waiting times and impact of the two week wait scheme on diagnosis and outcome of upper gastrointestinal cancer.

The NHS has introduced the two week wait scheme to detect upper gastrointestinal cancers at an early stage and improve survival rates The aim of this study was to assess the impact of this scheme and changes in endoscopy waiting times on tumour stage and resection rates over a four year period. Data were analysed prospectively for all patients diagnosed with oesophagogastric cancer between September 1998 and September 2002 and from those referred under the two week wait scheme since its introduction in 2000. Of those tumours diagnosed by this scheme (15%) only 5% were early disease (stage 1 or 2). Patients with early cancer, mainly diagnosed by routine gastroscopy, do not present with symptoms meeting the two week wait criteria. An increase in the resection rates for early disease will most probably be seen with a reduction in routine endoscopy waiting times.

Ambulatory Care↗
PubMed2004

Nest architecture and genetic differentiation in a species complex of Australian stingless bees.

We investigated the taxonomic significance of nest shape and its putative role in speciation in Trigona (Heterotrigona) carbonaria and T. (H.) hockingsi, two sibling species of stingless bee species from eastern Australia. These species are primarily distinguished by their nest architecture, as in all other respects they are nearly identical. We genotyped 130 colonies from six locations in Queensland at 13 microsatellite loci together with 106 additional colonies from six other Indo-Pacific Trigona species. Whether they were present in allopatry or in sympatry, colonies that displayed the T. carbonaria or the T. hockingsi nest architecture could be unambiguously differentiated at the genetic level. However, T. hockingsi colonies were classifiable into two highly differentiated paraphyletic and geographically separate populations, one in northern and one in southern Queensland. These two populations probably belong to two distinct species, T. hockingsi and T. davenporti nov. sp. Our results suggest that nest architecture characters are relevant but not sufficient criteria to identify species in this group. Consequently, modifications of nest architecture are probably not of prime importance in the speciation process of Australian stingless bees, although nest architecture differences probably result from relatively simple mechanisms. The rare interspecific hybrid colonies detected did not display a nest with an intermediate form between T. hockingsi and T. carbonaria.

Animals↗
PubMed2003

Sexual conflict and indirect benefits.

Recent work on sexual selection and sexual conflict has explored the influence of indirect effects on the evolution of female mating behaviour. It has been suggested that the importance of these effects has been underestimated and that the influence of indirect effects may actually be of relatively greater significance than direct effects. Additionally, it has also been suggested that all indirect effects, both good genes and sexy son, are qualitatively equivalent. Here a counterpoint to these suggestions is offered. We argue two main points: (1) it is unlikely that indirect effects will commonly outweigh direct effects, and (2) that there are important differences between good genes and sexy son indirect effects that must be recognized. We suggest that acknowledgement of these distinctions will lead to increased understanding of processes operating in both sexual conflict and sexual selection.

Adaptation, Physiological↗
PubMed2001

Validity and sensitivity of a pen computer battery of performance tests.

This study compared administration of performance tests and visual analogue scales (VAS) using a newly developed pen computer (PenC) battery with established tests using either pencil-and-paper (PP) or conventional computer. The performance of 47 subjects (23 male, age 18-45 years, weight 51-112 kg) was compared on the two systems after a dose of ethanol (0.8 g/kg up to a maximum of 60 g for males, 50 g for females) or placebo in a double-blind two-period randomized crossover study. Mean (SD) blood ethanol concentrations (breathalyser) were 94.5 mg/100 ml (21.9) at the start of the test battery (30 min post-drink) and 80.2 (13.0) at the end of the battery (75 min post-drink). Ethanol effects were found in all tests, with most outcome measures showing significant slowing or loss of accuracy. Results from the Rapid Visual Information Processing, Sentence Verification and Continuous Attention tasks show that the ethanol-placebo difference and the statistical significance of this difference are in close correspondence for the two modes of administration. The pen computer versions of these tasks may therefore be used as direct replacements for the previous versions. Digit-Symbol and maze tasks did not correspond so closely both showing differences in the speed-accuracy trade-off between the two modes. These tests, however, are sensitive to the effects of ethanol, and may be useful in their own right. Principal component analysis suggested that VAS may be grouped into two factors: (1) 'functional integrity', including measures of alertness and perceived proficiency, and (2) 'mood', including happiness and sociability. Factor 1 showed substantial effects of ethanol, while factor 2 was unchanged. There was close agreement between the results from PP and PenC for both factors as well as for the Sober-Drunk scale, which showed the expected effects of ethanol. Thus pen computer VAS perform in a similar way to the PP versions.

Adolescent↗
PubMed2000

Pulmonary endothelial permeability and circulating neutrophil-endothelial markers in patients undergoing esophagogastrectomy.

OBJECTIVE: Esophagogastrectomy is an established surgical treatment for esophageal malignancy. The postoperative period may be complicated by the development of acute lung injury syndromes and thus, may provide a useful model in which to study the early pathogenic mechanisms of inflammatory lung injury. DESIGN: Open, prospective study. SETTING: High dependency and intensive therapy units. PATIENTS: Eight healthy male volunteers and 20 patients in the early postoperative period INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The lung protein accumulation index (PAI) of radiolabeled transferrin was determined by using a portable, double-isotope system. The following circulating inflammatory markers-thought to reflect neutrophil-endothelial activation and injury including circulating neutrophil elastase-soluble L-, E-, and P-selectins and thrombomodulin and von Willebrand factor antigen were assayed from venous blood samples The PAI for healthy volunteers was median -0.5 (range, -1.73 to 0.27) x 10(-3)/min and for patients undergoing esophagogastrectomy -0.005 (range, -1.53 to 2.28) x 10(-3)/min. There was no statistical difference between the two groups. In the postesophagogastrectomy group, a significant elevation in circulating levels of neutrophil elastase, soluble P- and E-selectin, thrombomodulin, and von Willebrand factor antigen were observed relative to the control group but only circulating plasma elastase demonstrated a significant correlation with the PAI (r2 = .23, p =.03). CONCLUSIONS: The data suggest patients undergoing esophagogastrectomy develop a inflammatory response but this is not a surrogate of permeability and other factors are likely to determine persistent injury to the alveolar-capillary barrier function in this patient group.

Aged↗
PubMed2000

The deafening silence of AIDS.

For most of those attending the XIII International AIDS Conference in Durban, the Jonathan Mann Memorial Lecture delivered by Justice Edwin Cameron on Monday, 10 July 2000, was one of the highlights of the conference. The presentation is a passionate and compelling appeal to make medical care and treatment accessible and affordable to the more than 30 million people in resource-poor countries who face death from AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Inhibition and binding studies of coenzyme A and bovine phenol sulfotransferase.

Phenol sulfotransferases (PSTs, EC 2.8.2.1) catalyze sulfonyl group transfer from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to the hydroxyl oxygen of aromatic acceptor substrates. The structural overlap between PAPS and coenzyme A (CoA) suggested a possible role of this common acyl carrier in modulating PST activity. To test this hypothesis, purified recombinant bovine PST was examined by kinetic and affinity chromatographic approaches. After demonstrating PST enzyme inhibition by CoA, systematic variation of CoA and PAPS concentrations indicated simple competitive inhibition with K(i) = 1. 3 microM. PST bound to CoA-agarose, attached via the pantetheinyl thiol group, was eluted with PAP but not by 2-naphthol. This observation was consistent with the pattern of inhibition. Additional members of the sulfotransferase superfamily, as well as acylated CoAs, should be further investigated.

Animals↗
PubMed1998

Effects of IFN-beta on human cerebral blood flow distribution.

The effect of interferon-beta1b (IFN-beta) on human cerebral blood flow distribution was examined in five multiple sclerosis patients using functional brain single-photon emission tomography (SPECT). Of nine regions of interest studied, only the basal ganglia exhibited a significant change (increase) in relative photon emission intensity (i.e., relative blood flow) when comparing SPECT scans obtained 6 h after s.c. IFN-beta injection with scans obtained at the same time of day (noon) 30 h after IFN-beta injection (IFN-beta-free day). The increase in relative blood flow to the basal ganglia following IFN-beta injection correlated positively with changes in mean arterial pressure (MAP). Additional studies will be required to determine the relevance of these observations for IFN-beta-induced central nervous system side effects.

Adult↗
PubMed1997

Proviral insertions induce the expression of bone-specific isoforms of PEBP2alphaA (CBFA1): evidence for a new myc collaborating oncogene.

The til-1 locus was identified as a common retroviral integration site in virus-accelerated lymphomas of CD2-myc transgenic mice. We now show that viral insertions at til-1 lead to transcriptional activation of PEBP2alphaA (CBFA1), a transcription factor related to the Drosophila segmentation gene product, Runt. Insertions are upstream and in the opposite orientation to the gene and appear to activate a variant promoter that is normally silent in T cells. Activity of this promoter was detected in rodent osteogenic sarcoma cells and primary osteoblasts, implicating bone as the normal site of promoter activity. The isoforms encoded by the activated gene all encompass the conserved runt DNA-binding domain and share a novel N terminus different from the previously reported PEBP2alphaA products. Minor products include isoforms with internal deletions due to exon skipping and a novel C-terminal domain unrelated to known runt domain factors. The major isoform expressed from the activated til-1 locus (G1) was found to account for virtually all of the core binding factor activity in nuclear extracts from its corresponding lymphoma cell line. Another member of this gene family, AML1(CBFA2), is well known for its involvement in human hemopoietic tumors. These results provide evidence of a direct oncogenic role for PEBP2alphaA and indicate that the Myc and Runt family genes can cooperate in oncogenesis.

Amino Acid Sequence↗
PubMed1996

til-1: a novel proviral insertion locus for Moloney murine leukaemia virus in lymphomas of CD2-myc transgenic mice.

Moloney murine leukaemia virus (MoMLV) markedly accelerates thymic lymphoma development in mice carrying a transgene in which the human c-myc gene is linked to the CD2 locus control region. To investigate the mechanism of synergy and identify the genes which collaborate with myc in these clonal tumours, we analysed the sites of MoMLV insertion. Analysis of known viral integration loci revealed only a small number of insertions at bmi-1, pim-1 and ahi-1. Further cloning and hybridization analysis revealed a new common integration locus, designated til-1, which was occupied in 25 out of 77 lymphomas examined, with evidence of multiple clonal insertions in some cases. Mapping relative to established chromosomal markers in interspecific backcross mice located til-1 to mouse chromosome 17, distal to pim-1 and tic-1. These results suggest that the til-1 locus may harbour a novel myc-collaborating gene which acts as a target for activation in T cell lymphomas.

Animals↗
PubMed1994

Simultaneous development of diffuse immunoblastic lymphoma in recipients of renal transplants from a single cadaver donor: transmission of Epstein-Barr virus and triggering by OKT3.

Rapidly progressive diffuse immunoblastic lymphoma is an uncommon but devastating complication of organ transplantation that typically occurs early in the postoperative period. The fulminant course is characterized by progressive encephalopathy and coagulopathy, with malignant B-cell infiltration in the graft and other sites. Both de novo infection with Epstein-Barr virus (EBV) and treatment with the monoclonal antibody OKT3 have been implicated in the development of this disorder. We report two patients who received renal transplants from the same cadaver donor, with transmission of EBV from the same source, in whom treatment with OKT3 for acute rejection triggered the simultaneous development of fulminant and fatal B-cell immunoblastic lymphoma. We suggest that antilymphocyte agents be used with caution in EBV-seronegative graft recipients who receive a transplant from an EBV-seropositive donor to minimize the risk of this lethal complication.

Adolescent↗