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Biomedical subjects

R Jackson

Publications and source records attributed to R Jackson.

At least 163 records · Page 9Linked to original sources
PubMed1997

Declining rates of coronary heart disease in New Zealand and Australia, 1983-1993.

The authors report the results of 10 years of monitoring of trends in the rates of major nonfatal and fatal coronary events and in case fatality in Auckland, New Zealand, and in Newcastle and Perth, Australia. Continuous surveillance of all suspected myocardial infarctions and coronary deaths in people aged 35-64 years was undertaken in the three centers as part of the World Health Organization's Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) Project. For nonfatal definite myocardial infarction, there were statistically significant declines in rates in all centers in both men and women, with estimated average changes between 2.5% and 3.7% per year during the period 1984-1993. Rates of all coronary deaths also declined significantly in all three populations for both men and women. In absolute terms, there was, in general, a greater reduction in prehospital deaths than in deaths after hospitalization. Although 28-day case fatality remains high at between 35% and 50%, in the Australian centers it declined significantly by between 1.0% and 2.9% per year, and in Auckland there was also a small decline. However, since most deaths occur outside the hospital in people without a previous history of coronary heart disease, an increased emphasis on primary prevention is necessary.

Adult↗
PubMed1997

An homogeneous fluorescence polymerase chain reaction assay to identify Salmonella.

We have developed a semiquantitative homogeneous fluorescence assay that combines polymerase chain reaction (PCR) amplification with direct fluorescence detection (HF-PCR). The assay eliminates the need to perform gel electrophoresis on test samples. Using a set of Salmonella-specific primers, this system was used to verify suspect colonies from culture plates as Salmonella. The fluorescence signal is generated by a nucleic acid dye, YO-PRO-1, that is included in the amplification reaction. This homogeneous PCR assay was used to test 84 Salmonella strains picked from selective culture plates. All data indicated positive results when compared with 17 non-Salmonella strains (in general, Citrobacter, Hafnia, Proteus, and Escherichia). The HF-PCR assay is a sensitive, simple, accurate, and reproducible method that correlates well with size-exclusion high-performance liquid chromatography and gel electrophoresis techniques as a means to monitor PCR-mediated DNA amplification. This assay can confirm suspect colonies within 2.5 h.

Bacterial Typing Techniques↗
PubMed1997

Migraine: a risk factor for motor vehicle driver injury?

To test the hypothesis that migraine is associated with motor vehicle driver injury, data collected from 10,529 individuals on personal history of migraine and motor vehicle injury were analysed cross-sectionally. In multiple logistic regression analyses, the adjusted odds ratio for motor vehicle driver injury associated with migraine was 2.3 [95% confidence interval (CI) 1.9-2.7]. After excluding those who also had a history of head injury, the odds ratio was 1.5 (95% CI: 1.2-2.0). These results suggest that migraine may be associated with a 50% increase in the risk of motor vehicle driver injury and that in this population may account for as many as one in every 20 motor vehicle driver injuries. These findings require confirmation in prospective studies of motor vehicle driver injuries.

Accidents, Traffic↗
PubMed1997

Progress towards using recombinant myxoma virus as a vector for fertility control in rabbits.

The history of myxoma virus, its use in Australia as a mortality agent and the development of the virus as a vector for controlling fertility in wild rabbit populations in Australia is reviewed. Myxoma virus recombinants have been constructed to express model antigens. Four potential insertion sites in the genome have been identified and two have been used to construct single and double recombinant viruses expressing Escherichia coli enzymes beta-galactosidase and beta-glucuronidase. Another recombinant expressing an influenza virus haemagglutinin gene (A/PR8/34) induced high and sustained antibody responses following intradermal inoculation in rabbits. To demonstrate the potential of introducing a recombinant virus into wild rabbit populations, a virus containing a natural deletion was released at four field locations. Preliminary analysis of the data has shown that the introduced virus spread well on 3 of the 4 locations. The steps being taken to address the ethical and safety implications of the introduction of a recombinant virus into the field are discussed.

Animals↗
PubMed1997

Specificity of the high-mannose recognition site between Enterobacter cloacae pili adhesin and HT-29 cell membranes.

Enterobacter cloacae has been implicated as one of the causative agents in neonatal infection and causes a septicemia thought to be initiated via the gastrointestinal tract. The adhesion of radiolabeled E. cloacae to HT-29 cells was concentration and temperature dependent and was effectively blocked by unlabeled bacteria or by millimolar concentrations of alpha-mannosides and micromolar concentrations of high-mannose oligosaccharides. A variety of well-characterized mannose oligosaccharides were tested as inhibitors of adhesion. The best inhibitor was the Man9(GlcNAc)2-tyrosinamide, which was considerably better than other tyrosinamide-linked oligosaccharides such as Man7(GlcNAc)2, Man6(GlcNAc)2 or Man5(GlcNAc)2. Further evidence that the bacteria preferred Man9(GlcNAc)2 structures was obtained by growing HT-29 cells in the presence of glycoprotein processing inhibitors that block mannosidase I and increase the amount of protein-bound Man9(GlcNAc)2 at the cell surface. Such cells bound 1.5- to 2-fold more bacteria than did control cells. The adhesin involved in binding to high-mannose structures was purified from isolated pili. On sodium dodecyl sulfate-gels, a 35-kDa protein was identified by its specific binding to a mannose-containing biotinylated albumin. The amino acid sequences of several peptides from the 35-kDa subunit showed over 85% identity to FimH, the mannose-specific adhesin of Salmonella typhimurium. Pili were labeled with 125I and examined for the ability to bind to HT-29 cells. Binding showed saturation kinetics and was inhibited by the addition of Man9(GlcNAc)2-tyrosinamide but not by oligosaccharides with fewer mannose residues. Polyclonal antibody against this 35-kDa protein also effectively blocked adhesion of pili or E. cloacae, but no effect was observed with nonspecific antibody. These studies demonstrate that the 35-kDa pilus subunit is a lectin whose specificity is directed toward Man, (GlcNAc)2 oligosaccharides.

1-Deoxynojirimycin↗
PubMed1997

Information systems on the Internet: time to make the move.

World Wide Web-based systems are the way to go, say the experts. They are less costly and often more flexible than internal systems. And, the experts say, concerns about security and speed, though justified, need not stop organizations from making the switch.

Computer Communication Networks↗
PubMed1997

Marketing healthcare globally: make it work for your organization.

Geographic location and good patient care alone will not guarantee a successful international program. Organizations attracting foreign patients talk about weighing the chances of successfully launching a program, making sure the system is ready to provide customized patient services and--instead of advertising their services--marketing one-on-one.

Advertising↗
PubMed1997

Medical instruments in the Roman world.

By the beginning of the 1st century AD Roman medical instruments had begun to acquire the distinctive forms which they were to retain, more or less unchanged, for the next half millennium. They were carefully-designed, highly-crafted precision tools well-adapted to the range of surgical interventions and operations described in the contemporary medical texts. Their versatility and multiplicity of function is discussed, as also is the evidence derived from apparently complete instrumentaria, which sheds light on the form of medical practise undertaken by the people who used them.

Equipment and Supplies↗
PubMed1996

HIV replication in CD4+ T cells of HIV-infected individuals is regulated by a balance between the viral suppressive effects of endogenous beta-chemokines and the viral inductive effects of other endogenous cytokines.

This study demonstrates that the beta-chemokines macrophage inflammatory proteins 1 alpha and 1 beta (MIP-1 alpha and MIP-1 beta) and, RANTES (regulated on activation, normally T-cell expressed and secreted) inhibit human immunodeficiency virus (HIV) replication in anti-CD3 or recall antigen-stimulated peripheral blood mononuclear cells (PBMCs) of asymptomatic HIV-infected subjects. Significant levels of beta-chemokines were produced by both CD4+ and CD8+ PBMC subsets from HIV-infected individuals. Neutralization of endogenous MIP-1 alpha, MIP-1 beta, and RANTES did not rescue HIV replication in cultures to which greater than 10% CD8+ T cells had been added, indicating that the HIV suppressor activity of CD8+ T cells cannot be explained entirely by the beta-chemokines. However, significant enhancement of viral replication was observed upon neutralization of endogenous beta-chemokines in CD8-depleted or CD4+ PBMCs from most donors, particularly in cultures with low inducible levels of HIV production. In contrast, certain endogenous proinflammatory cytokines induced HIV replication in these same cells. These data suggest that the levels of HIV replication in CD4+ PBMC reflect the balance of the opposing effects of endogenous suppressive factors, such as the beta-chemokines, and HIV-inducing cytokines, such as tumor necrosis factor alpha and interleukin 1 beta.

CD4-Positive T-Lymphocytes↗
PubMed1996

A mutation in the transforming growth factor beta type II receptor gene promoter associated with loss of gene expression.

Expression of transforming growth factor beta type II receptors (TbetaR-IIs) is either greatly decreased or absent in many tumors, implying that the loss of TbetaR-II function is one of the mechanisms leading to tumor development. In this report, we examine the expression of the TbetaR-II receptor in a squamous carcinoma cell line that expressed reduced levels of TbetaR-II mRNA. We found an A --> G mutation at position -364 of the 5' untranslated region of the TbetaR-II gene. This mutation results in significantly decreased transcriptional activity by the TbetaR-II gene promoter, suggesting that it is a primary mechanism of loss of TbetaR-II expression in this tumor cell line.

Cell Line↗