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Biomedical subjects

E M Campbell

Publications and source records attributed to E M Campbell.

At least 19 recordsLinked to original sources
PubMed2005

Comparison of laser ion acceleration from the front and rear surfaces of thin foils.

The comparative efficiency and beam characteristics of high-energy ions generated by high-intensity short-pulse lasers (approximately 1-6 x 10(19) W/cm2) from both the front and rear surfaces of thin metal foils have been measured under identical conditions. Using direct beam measurements and nuclear activation techniques, we find that rear-surface acceleration produces higher energy particles with smaller divergence and a higher efficiency than front-surface acceleration. Our observations are well reproduced by realistic particle-in-cell simulations, and we predict optimal criteria for future applications.

Journal Article↗
PubMed2005

Gene therapy progress and prospects: viral trafficking during infection.

The intracellular steps involved in viral infection, namely cytoplasmic trafficking and nuclear import, are critical events in the viral life cycle that have lagged behind other areas of viral research. This review examines recent advances in our understanding of these steps for viruses commonly employed as viral gene delivery vectors. Steps governing the cytoplasmic trafficking and nuclear import of Herpes Simplex virus, Human Immunodeficiency virus and Adenovirus are reviewed in this article.

Adenoviridae↗
PubMed2003

Spatial uniformity of laser-accelerated ultrahigh-current MeV electron propagation in metals and insulators.

The evolution of laser-generated MeV, MA electron beams propagating through conductors and insulators has been studied by comparing measurement and modeling of the distribution of MeV protons that are sheath accelerated by the propagated electrons. We find that electron flow through metals is uniform and can be laser imprinted, whereas propagation through insulators induces spatial disruption of the fast electrons. Agreement is found with material dependent modeling.

Journal Article↗
PubMed2001

Fast ignition by intense laser-accelerated proton beams.

The concept of fast ignition with inertial confinement fusion (ICF) is a way to reduce the energy required for ignition and burn and to maximize the gain produced by a single implosion. Based on recent experimental findings at the PETAWATT laser at Lawrence Livermore National Laboratory, an intense proton beam to achieve fast ignition is proposed. It is produced by direct laser acceleration and focused onto the pellet from the rear side of an irradiated target and can be integrated into a hohlraum for indirect drive ICF.

Journal Article↗
PubMed2001

An updated linkage and comparative map of porcine chromosome 18.

Swine chromosome 18 (SSC18) has the poorest marker density in the USDA-MARC porcine linkage map. In order to increase the marker density, seven genes from human chromosome 7 (HSA7) expected to map to SSC18 were selected for marker development. The genes selected were: growth hormone releasing hormone receptor (GHRHR), GLI-Kruppel family member (GLI3), leptin (LEP), capping protein muscle Z-line alpha 2 subunit (CAPZA2), beta A inhibin (INHBA), T-cell receptor beta (TCRB) and T-cell receptor gamma (TCRG). Large-insert clones (YACs, BACs and cosmids) that contained these genes, as well as two previously mapped microsatellite markers (SW1808 and SW1984), were identified and screened for microsatellites. New microsatellite markers were developed from these clones and mapped. Selected clones were also physically assigned by fluorescence in situ hybridization (FISH). Fifteen new microsatellite markers were added to the SSC18 linkage map resulting in a map of 28 markers. Six genes have been included into the genetic map improving the resolution of the SSC18 and HSA7 comparative map. Assignment of TCRG to SSC9 has identified a break in conserved synteny between SSC18 and HSA7.

Animals↗
PubMed2000

Intense high-energy proton beams from Petawatt-laser irradiation of solids.

An intense collimated beam of high-energy protons is emitted normal to the rear surface of thin solid targets irradiated at 1 PW power and peak intensity 3x10(20) W cm(-2). Up to 48 J ( 12%) of the laser energy is transferred to 2x10(13) protons of energy >10 MeV. The energy spectrum exhibits a sharp high-energy cutoff as high as 58 MeV on the axis of the beam which decreases in energy with increasing off axis angle. Proton induced nuclear processes have been observed and used to characterize the beam.

Journal Article↗
PubMed2000

Accidents in older people living at home: a community-based study assessing prevalence, type, location and injuries.

OBJECTIVES: To assess the prevalence, type, location of and injuries from home accidents, including falls and other accidents, and to explore whether variables including socio-demographic characteristics, medication use and home hazards were associated with all home accidents and falls. METHOD: 657 older people were interviewed about accidents in the previous four weeks. For a subsample (n = 425), a home hazard check was completed. RESULTS: Of the 101 accidents reported, 51% (n = 51) were falls and 50% (n = 50) were other accidents. The most common location for all accidents was outside (30%). Most resulted in minor injury to the legs (43%) or arms (39%). Medical treatment was sought for 14% of accidents. Having more than five hazards and infrequent home visits by healthcare providers were associated with having at least one accident and at least one fall. Use of a walking aid was also associated with falling. CONCLUSION: Rates of falls and other accidents are considerable. IMPLICATIONS: Work is required to confirm the importance of the relationships suggested and to provide data on the burden of injury associated with non-fall accidents.

Accidental Falls↗
PubMed2000

Collecting cancer risk factor data from hospital outpatients: use of touch-screen computers.

The aim of this study was to assess the prevalence of selected cancer risk factor data from hospital outpatients and the proportion of "at risk" patients who would like help from hospital staff to reduce risk factors. A touch-screen computer collected data from outpatients in Newcastle, NSW, Australia. Eight hundred and nineteen outpatients completed the computerized interview. Of these, 35% were smokers, of whom 25% said that they would like help to stop smoking; 47% were overweight, with 48% indicating that they wanted assistance; 17% consumed harmful levels of alcohol, with 2% wanting help; 30% of eligible women were overdue for a Pap test, of whom 75% said that they wanted a referral to be screened, and 25% were overdue for a mammogram, of whom 83% said that they would like a referral for an examination. Touch-screen computerized health risk assessments are practical for collecting and monitoring valid cancer risk factor data for hospital outpatients.

Adolescent↗
PubMed1999

Monocyte chemoattractant protein-1 mediates cockroach allergen-induced bronchial hyperreactivity in normal but not CCR2-/- mice: the role of mast cells.

Bronchial eosinophil and mononuclear cell infiltrates are a hallmark of the asthmatic lung and are associated with the induction of reversible airway hyperreactivity. In these studies, we have found that monocyte chemotactic protein-1 (MCP-1), a CC (beta) chemokine, mediates airway hyperreactivity in normal and allergic mice. Using a murine model of cockroach Ag-induced allergic airway inflammation, we have demonstrated that anti-MCP-1 Abs inhibit changes in airway resistance and attenuate histamine release into the bronchoalveolar lavage, suggesting a role for MCP-1 in mast cell degranulation. In normal mice, instillation of MCP-1 induced prolonged airway hyperreactivity and histamine release. In addition, MCP-1 directly induced pulmonary mast cell degranulation in vitro. These latter effects would appear to be selective because no changes were observed when macrophage-inflammatory protein-1alpha, eotaxin, or MCP-3 were instilled into the airways of normal mice or when mast cells were treated in vitro. Airway hyperreactivity was mediated by MCP-1 through CCR2 because allergen-induced as well as direct MCP-1 instilled-induced changes in airway hyperreactivity were significantly attenuated in CCR2 -/- mice. The neutralization of MCP-1 in allergic animals and instillation of MCP-1 in normal animals was related to leukotriene C4 levels in the bronchoalveolar lavage and was directly induced in pulmonary mast cells by MCP-1. Thus, these data identify MCP-1 and CCR2 as potentially important therapeutic targets for the treatment of hyperreactive airway disease.

Administration, Intranasal↗
PubMed1999

Anti-inflammatory actions of interleukin-13: suppression of tumor necrosis factor-alpha and antigen-induced leukocyte accumulation in the guinea pig lung.

The Th2 cytokine interleukin (IL)-13 is believed to play an important role in the development of allergy, although it has also been ascribed anti-inflammatory roles in several experimental models. In this study, we have examined the effects of human recombinant IL-13 on eosinophilic lung inflammation in the guinea pig. IL-13 (1 to 100 ng, given by intratracheal instillation) did not elicit airway eosinophil recruitment. A pronounced accumulation of eosinophils, as well as monocyte/macrophages, was elicited by intratracheal instillation of guinea pig tumor necrosis factor alpha (gpTNF-alpha). Intratracheal administration of IL-13 (1 to 100 ng) given immediately prior to exposure to gpTNF-alpha resulted in a dose-related suppression of eosinophil and monocyte/macrophage accumulation in the airways, as assessed by bronchoalveolar lavage (BAL) and eosinophil peroxidase activity in whole-lung homogenates. IL-13 treatment also reduced BAL fluid (BALF) leukocyte accumulation induced by subsequent aerosol antigen challenge of sensitized guinea pigs. Antigen challenge also resulted in elevated levels of immunoreactive eotaxin and eosinophil-stimulating activity in BALF, although only the latter was reduced significantly by IL-13 instillation prior to challenge. In contrast to the suppressive effects of IL-13, instillation of human recombinant IL-4 (100 ng) alone elicited an increase in BALF monocyte/macrophage numbers, and IL-4 was unable to inhibit gpTNF-alpha-induced leukocyte accumulation. Hence, IL-13 (but not human IL-4) exhibits an anti-inflammatory action in the airways of gpTNF-alpha- or antigen-challenged guinea pigs, by mechanisms that may involve the decreased generation of eosinophil-stimulating activity in the airways.

Animals↗
PubMed1998

Temporal role of chemokines in a murine model of cockroach allergen-induced airway hyperreactivity and eosinophilia.

The increase in inner-city asthma among children appears to be due to allergic responses to several allergens. Recent studies have demonstrated that Ags derived from cockroaches are especially prominent in these settings and a significant health concern for the induction of asthma in children. In the present study, we have outlined the development of a murine model of cockroach allergen-induced airway disease and assessed specific mechanisms of the response, which resembles atopic human asthma. The allergic responses in this model include allergen-specific airway eosinophilia and significantly altered airway physiology, which directly correlates with inflammation. We have further utilized this allergen to establish primary and secondary rechallenge stages of late phase hyperreactivity exacerbation. This latter stage is characterized by greater changes in airway physiology than the primary stage, and it is likely due to the preexisting peribronchial inflammation present at the time of the second allergen rechallenge. We have identified specific roles for CC chemokines during these stages, with MIP-1alpha being an important eosinophil attractant during the primary stage and eotaxin during the secondary rechallenge stage. The development of these models allows the evaluation of mediators involved in both stages of cockroach allergen challenge, as well as the testing of specific therapeutic modalities.

Allergens↗
PubMed1998

Breaking bad news. 3: Encouraging the adoption of best practices.

Steps to encourage clinicians to adopt the best practices for communicating bad news to patients are outlined. First, official, credible guidelines endorsed by key organizations or professional bodies, giving a clear message about the components and importance of the best practices, must be produced. Second, the guidelines should be disseminated; publication in journals or mailing to clinicians is unlikely to be sufficient. Third, clinicians should be provided with feedback on whether their performance meets established standards. This requires acceptable systems to collect valid and reliable performance data. Fourth, clinicians need contingencies for providing best practice care. Fifth, barriers to improvement should be explored and strategies to address them, including interactional skills training, implemented. Continuous quality assurance, commitment, and evaluations will help clinicians use the best practices for breaking bad news to patients.

Benchmarking↗
PubMed1997

Recombinant guinea pig and human RANTES activate macrophages but not eosinophils in the guinea pig.

To characterize the biologic activities of potential mediators of allergic inflammation, we have cloned, expressed, and purified guinea pig RANTES (gpRANTES). cDNA for gpRANTES was cloned from Con A-stimulated guinea pig spleen cells. A high level of gpRANTES expression in Escherichia coli was achieved by mutation of a human RANTES (hRANTES) expression construct to obtain a 68-amino acid protein identical with the predicted guinea pig amino acid sequence, assuming an equivalent amino terminus as the human protein. Purified gpRANTES was an effective stimulus of human eosinophils as assessed by increases in intracellular free calcium in fura-2-loaded cells and chemotactic responses in vitro. gpRANTES exhibits similar potency and efficacy to hRANTES. In marked contrast, neither gpRANTES nor hRANTES was able to activate guinea pig peritoneal eosinophils in these assays, even in the presence of IL-5. However, gpRANTES was found to be a potent stimulator of guinea pig peritoneal macrophages. Following tracheal instillation of gpRANTES, a dose-dependent increase in macrophages, but not eosinophils, was observed in gpBAL. Macrophage accumulation was detectable by 6 h and sustained for at least 48 h. These results indicate that RANTES in the guinea pig may have a different cellular selectivity than that described in the human, which may be important in the use of animal models in the analysis of allergic disorders. These selectivities do not appear to be accounted for by differences in guinea pig and human RANTES sequences.

Amino Acid Sequence↗
PubMed1997

Environmental hazards in the homes of older people.

OBJECTIVES: To investigate (i) the prevalence of environmental safety hazards in the homes of people aged 70 years and over, (ii) their knowledge of causes of injuries to older people and the safety measures they can implement to prevent such injuries and (iii) the relationship between socio-demographic characteristics of this population group and levels of home environmental hazards. METHOD: A cross-sectional survey of 425 people aged 70 years and older living in a defined geographical area of Australia. Participants were recruited through their general practitioners. A structured interview completed with each participant included questions on demographics and home safety issues. A home safety inspection was also undertaken using a predetermined rating format. RESULTS: 80% (n = 342) of homes inspected had at least one hazard and 39% (n = 164) had > 5 hazards. The bathroom was identified as the most hazardous room, with 66% (n = 279) of bathrooms having at least one hazard. Hazards relating to floor surfaces (62% of homes had one 'flooring' hazard) and absence of appropriate grab or handrails (60% of homes had one or more hazards relating to this) were prevalent. Eighty-eight percent (n = 374) of older people were able to identify falls as the most common cause of injury and 87% (n = 368) were able to accurately name at least one safety measure. Although a significant association was found between the older people's self-assessment of their home's safety and the presence of more than 5 hazards, 30% of those rating their homes as very safe (n = 289) had more than 5 hazards. Logistic regression analysis identified one variable--contact with healthcare service providers--as predictive of the hazard level in older people's homes. Older people who were never visited by service providers were twice as likely to have more than 5 hazards as those who were visited weekly or more often (OR 2.12, 95% CI 1.104, 4.088). CONCLUSION: Many older people are living in potentially hazardous environments. As yet, a causal link between the presence of environmental hazards and falls in older people has not been established. More definitive work in this area needs to be carried out.

Aged↗