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Biomedical subjects

A Hope

Publications and source records attributed to A Hope.

At least 19 recordsLinked to original sources
PubMed2006

No changes in lung function after a saturation dive to 2.5 MPa with intermittent reduction in Po2 during decompression.

Decompression stress and exposure to hyperoxia may cause a reduction in transfer factor of the lung for carbon monoxide and in maximal aerobic capacity after deep saturation dives. In this study lung function and exercise capacity were assessed before and after a helium-oxygen saturation dive to a pressure of 2.5 MPa where the decompression rate was reduced compared with previous deep dives, and the hyperoxic exposure was reduced by administering oxygen intermittently at pressures of 50 and 30 kPa during decompression. Eight experienced divers of median age 41 years (range 29-48) participated in the dive. The incidence of venous gas microemboli was low compared with previous deep dives. Except for one subject having treatment for decompression sickness, no changes in lung function or angiotensin converting enzyme, a marker of pulmonary endothelial cell damage, were demonstrated. The modified diving procedures with respect to decompression rate and hyperoxic exposure may have contributed to the lack of changes in lung function in this dive compared with previous deep saturation dives.

Adult↗
PubMed2003

Strong association of the Saitohin gene Q7 variant with progressive supranuclear palsy.

Recent reports are inconclusive in showing that the Q7R polymorphism of the novel Saitohin gene, nested in intron 9 of the tau gene, is associated with AD. The authors show that this polymorphism is in complete linkage disequilibrium with the extended tau H1/H2 haplotype and that the Q variant and QQ genotype of Q7R are strongly associated with progressive supranuclear palsy, implicating it as a possibly important pathogenic candidate.

Aged↗
PubMed2003

Pathological inclusion bodies in tauopathies contain distinct complements of tau with three or four microtubule-binding repeat domains as demonstrated by new specific monoclonal antibodies.

Pathological inclusions containing fibrillar aggregates of hyperphosphorylated tau protein are a characteristic feature in the tauopathies, which include Alzheimer's disease, frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), progressive supranuclear palsy, corticobasal degeneration and Pick's disease. Tau isoform composition and cellular and regional distribution as well as morphology of these inclusions vary in each disorder. Recently, several pathological missense and exon 10 splice-donor site mutations of the tau gene were identified in FTDP-17. Exon 10 codes for the second of four microtubule-binding repeat domains. The splice-site mutations result in increased inclusion of exon 10 which causes a relative increase in tau isoforms containing four microtubule-binding repeat domains over those containing three repeat domains. This could be a central aetiological mechanism in FTDP-17 and, perhaps, other related tauopathies. We have investigated changes in the ratio and distribution of three-repeat and four-repeat tau in the different tauopathies as a basis of the phenotypic range of these disorders and the selective vulnerability of different subsets of neurones. In this study, we have developed two monoclonal antibodies, RD3 and RD4 that effectively distinguish these closely related tau isoforms. These new isoform-specific antibodies are useful tools for analysing tau isoform expression and distribution as well as pathological changes in the human brain.

Animals↗
PubMed2003

Increased oxygen before and during decompression reduces bubble formation in rats.

The aim of this study was to test the hypothesis that increased oxygen partial pressure shortly before and during decompression from hyperbaric pressures would decrease venous gas bubble formation. Bubbles were detected by an ultrasound Doppler technique in conscious, freely moving rats. All rats were exposed twice to 6 bar for 2 hours. In exposure A, the breathing gas mixture was 1 bar O2 and 5 bar N2. In exposure B, the breathing gas was changed to 2 bar O2 and 4 bar N2, 5 min prior to decompression. The decompression rate was 0.1 bar x s(-1) in both groups. Significantly fewer bubbles were detected after decompression in exposure B compared to A. The angiotensin converting enzyme (ACE) concentration in serum was measured as an indicator of possible damage to the pulmonary endothelium induced by bubbles. However, no correlation between ACE and bubble amount was found. In conclusion, this study in conscious rats indicates that safer decompression may be obtained by increasing the oxygen partial pressure before and during decompression.

Animals↗
PubMed2002

Impact evaluation of an oral health intervention amongst primary school children in Ireland.

A pilot oral health programme was developed which aimed to improve dental health knowledge and behaviour amongst Irish school children aged 7-12 years. The programme comprised two integral components: a television campaign, run over a 6-week period, was incorporated into the children's programme 'Den TV' on national television, with video clips of a member of the music band Boyzone promoting key oral health messages; and a Smile of the Year contest. Concurrently, a dental nurse delivered an interactive talk with pupils, showed a video of the Den TV oral health programme and distributed posters and leaflets. The aim of this study was to assess the impact of the overall intervention on school pupils' dental health knowledge and reported behaviour. Thirty-two primary schools in two health board regions in the Republic of Ireland participated in the study. At baseline and after 6 weeks, 1534 school children completed specially developed questionnaires. There was a positive net effect of the dental nurse intervention in all but one question. The percentage of children who reported using the recommended amount of toothpaste and brushing for 3 min appeared to have been further increased having observed the television campaign. These results are in line with the argument that mass media campaigns work to supplement the one-to-one activities of health professionals in order to effect knowledge and behavioural change.

Child↗
PubMed2001

Dehydration and body fluid-regulating hormones during sweating in warm (38 degrees C) fresh- and seawater immersion.

Body weight (BW) reductions of more than 4 kg have been observed during diving with the open hot water suit, a technique in which heated seawater (SW) continuously floods the skin surface. To test the hypothesis that osmotic effects may be involved in these fluid-loss processes, head-out immersion experiments in 38 degrees C freshwater (FW) and SW for 4 h were performed. Average BW reduction was 2.5 and 1.9 kg in SW and FW head-out immersion, respectively (P < 0.01). Atrial natriuretic peptide increased during the first 30 min of SW immersion (5.6-13.4 pmol/l, P < 0.01) followed by a reduction to 7.6 pmol/l (P < 0.01). This paralleled an initial decrease in aldosterone (from 427 to 306 pmol/l, P < 0.05) followed by an increase to 843 pmol/l (P < 0.01). The effects of temperature on fluid loss were studied in thermoneutral (34.5 degrees C) and 38 degrees C SW for 2 h. In thermoneutral SW, calculated sweat production was negligible (0.05 kg) compared with 1.2 kg in warm SW. We recommend that, if a dive is planned to last for more than 4 h, a mandatory break for fluid intake should be incorporated in the diving regulations.

Adult↗
PubMed2001

A rapid access husky voice clinic: useful in diagnosing laryngeal pathology.

A new established pilot husky voice clinic with agreed referral protocols for patients at risk of developing laryngeal malignancy was audited. Thirty-four patients were seen, 41.2 per cent having abnormal findings on flexible nasendoscopy, 29.4 per cent requiring rigid endoscopy, 38.1 per cent were discharged after the initial visit. One case of early laryngeal cancer was picked up during this period from this group of patients. The data for the remaining population in Portsmouth was examined, and a further eight cases of laryngeal cancer were diagnosed in keeping with national incidences. A rapid access clinic with agreed protocols that referring practitioners adhered to, was useful for diagnosing laryngeal cancer and should meet the requirements of the government's 14-day rule.

Adult↗
PubMed2001

Thermal insulation properties of argon used as a dry suit inflation gas.

Uncontrolled observations from the "technical" diving community claim superior thermal comfort when replacing air with argon as dry suit inflation gas during diving. The objective of the present experiment was to evaluate the effectiveness of argon compared to air during cold water diving. Body weight, urinary output, and rectal and skin temperatures were measured in six naval divers during two dives to approximately 10 m for 60 min. Level of thermal comfort was reported. Dry suit gas was either argon or air, divers and scientists were blinded for gas identity. Urinary output was approximately 200 ml less (P < 0.05) during the air than the argon dives. Rectal and all skin temperatures decreased significantly in both groups during the dive but no difference was measured between argon and air dives. Thermal comfort was not different between the groups. Replacing air with argon neither improves subjective impression of thermal comfort nor attenuates core or skin cooling during cold water diving to 10 meters of sea water for 60 min.

Adult↗
PubMed2000

Modification of a bovine ELISA to detect camelid antibodies to Mycobacterium paratuberculosis.

Mycobacterium avium subsp. paratuberculosis infection, or Johne's disease, reportedly has a low prevalence in South American camelid populations. Recently, however, single cases in the United States as well as an outbreak of the disease in Australian alpacas (Lama pacos) have been described. To provide a rapid and cost-effective method of diagnosing Johne's disease in this species, the bovine Parachek((R)) Johne's Absorbed EIA (CSL, Vic., Australia) was modified to create a camelid-specific serum antibody assay. An anti-llama IgG conjugated to horseradish peroxidase replaced the anti-bovine immunoglobulin. Checkerboard titration of principal reagents was performed using serum from nine tissue and/or fecal culture-positive camelids. Optimal dilutions of key components were determined in order to provide clear discrimination between positive and negative controls. Completion of a kinetic assay determined the optical density at which the enzyme-substrate reaction should be stopped. A herd of 100 camelids with no history of disease or exposure to M. a. paratuberculosis, a subset of which were tissue and/or fecal culture-negative, was tested to establish a cut-off value. Sample results were expressed as a percentage of the results for control sera by transforming optical density values to ELISA values (EV%). A preliminary EV% cut-off of 20 was established. Using this prototype assay, culture-positive animals showed significantly different antibody responses from culture-negative animals. These results indicate that this camelid-specific ELISA, once refined, may be a useful tool for screening camelid herds for M. a. paratuberculosis infection.

Animals↗
PubMed2000

A community needs assessment for rural mental health promotion.

This paper describes the needs assessment phase of a mental health promotion programme for rural communities in Ireland. As part of a larger study encompassing four rural communities, a cross-sectional study of the mental health beliefs and perceptions of 1014 people was carried out. Employing a combination of interviewer-administered questionnaire and the vignette method, the needs assessment explores the levels of awareness, current practices, attitudes and stigma concerning depression and suicide among a randomly selected quota sample of community members. Lower levels of awareness, less confidence in dealing with mental health issues, negative attitudes to help-seeking and social stigma emerge as particular issues for men and the under 40 age group. Women were found to have more positive attitudes generally, were more likely to use informal social support networks and were more open about discussing mental health matters. The predominant interpretation of the depression vignette was to view it as a mental health problem with good prospects for recovery given appropriate help. Social relationships, negative thinking patterns and social stresses were perceived as being particularly important in explaining the origins of depression. The implications of the findings for planning the intervention phase of the project are considered.

Adult↗
PubMed2000

DNA fingerprinting of Australian isolates of Mycobacterium avium subsp paratuberculosis using IS900 RFLP.

OBJECTIVES: To evaluate additional restriction enzymes for IS900 RFLP of Mycobacterium avium subsp paratuberculosis and examine the genetic diversity among Australian isolates for epidemiological studies of Johne's disease. DESIGN AND PROCEDURE: Seventy-one isolates of M paratuberculosis from cattle, sheep, goat, alpaca and rhinoceros in six Australian States and the Northern Territory, reference strains and reference DNA from previously characterised strains were tested for genetic variation. Bst EII, Pvu II and Pst I restriction enzymes were used, and four others (Bam HI, Alu I, Xho I and Dra I) were assessed for their ability to detect polymorphisms. Multiple isolates from some animals were tested. RESULTS: Bam HI, was the most effective enzyme for identifying polymorphisms (12 types), followed by Bst EII (11 types). Both Pvu II and Pst I were relatively ineffectual. Fifteen different types were identified, 12 in clinical isolates. Most isolates were cattle (C) strains and fell into the C1 (n = 28) and C3 (n = 32) groupings. All isolates from alpaca were type C1, and bovine isolates were commonly C1 (n = 15) or C3 (n = 28). All of the sheep were infected with sheep (S) strains; no S strains were identified in cattle. Two of six isolates from one animal had single band differences. CONCLUSION: The epidemiological features of M paratuberculosis in Australia are similar to those reported in New Zealand, where cattle and sheep are commonly infected with different strains. However, because of the lack of polymorphism identified within the major groups, it is unlikely that DNA fingerprinting will have a significant role in epidemiological studies of Johne's disease, unless an unusual strain in being studied.

Animals↗
PubMed2000

Specificity of four serologic assays for Mycobacterium avium ss paratuberculosis in llamas and alpacas: a single herd study.

An investigation was conducted for Mycobacterium avium ss paratuberculosis infections in a research herd of llamas and alpacas. Herd culture-negative status was established over a 23-month period by screening any individuals with any signs compatible with paratuberculosis (n = 1), high serology values (n = 8), or other health and research related reasons (n = 24). There were no M. avium ss paratuberculosis isolates from radiometric cultures of multiple tissue and fecal samples from these individuals and no known sources of exposure. Paratuberculosis is uncommon in North American llamas and alpacas: only 5 cases were identified after an extensive search of the Veterinary Medical Data Base, diagnostic laboratory records, publication databases, and personal communications. Therefore, serum samples from llamas (n = 84) and alpacas (n = 16) in the culture-negative herd were used to obtain preliminary estimates of test specificity for 3 enzyme-linked immunoassays (ELISAs) and an agar gel immunodiffusion (AGID) assay kit for detecting serum antibodies to M. avium ss paratuberculosis in South American camelids. The ELISAs were modifications of established bovine assays for antibody detection. With provisional cutoffs, ELISA-A had 52 false positives (specificity 48%), ELISA-B had 8 false positives (specificity 92%), ELISA-C had two false positives (specificity 98%), and the AGID had 0 false positives (specificity 100%). The range of ELISA values for culture-positive llamas and alpacas (n = 10) from other herds overlapped the range of values for culture-negative llamas and alpacas. The accuracy of the ELISAs may be improved by using age- and sex-specific cutoffs because uninfected male llamas and alpacas that were older than 1 year had higher values for some tests. These tests can be used for either llamas or alpacas; the protein-G conjugate ELISA (ELISA-B) may be useful for multispecies applications. These assays are best used for rapid presumptive diagnoses of llamas and alpacas with diarrhea and weight loss and as a screening tool for herds known to be exposed to infection. All seropositive results should be confirmed with culture.

Animals↗
PubMed1999

Health and safety practices among farmers and other workers: a needs assessment.

The development of appropriate health and safety interventions for farmers and agri-workers is important world-wide but data on present practices and attitudes to change are lacking. A representative quota sample (n = 1,938) of the Irish population was surveyed on lifestyle practices and workplace risk assessment and control measures, in relation to chemical exposure, manual handling and machinery. Focus group discussions were conducted also with 47 representatives of national farming organizations. As compared with the general workforce, farmers had a significantly (p < 0.01) lower level of assessment of risk hazards associated with manual handling and machinery. Both farmers and employees in workplaces with less than 20 employees reported a significantly lower level of safety training. Male farmers had a particularly negative health profile with only 18% reporting regular dental checks, 26% practising skin protection and 29% taking regular exercise. Discussions indicated that barriers to change included low perceived susceptibility, lack of time and resources. Mental health issues were particularly highlighted. We conclude farmers differ significantly in many instances from the rest of the workforce in regard to occupational health and safety issues and specific interventions in key areas are required for the agri-sector.

Adolescent↗
PubMed1998

Lifestyle practices and the health promoting environment of hospital nurses.

Lifestyle practices and the health promoting environment of hospital nurses This paper examined the lifestyle practices of hospital nurses and the impact of specific interventions in the hospital environment. The perception of nurse as health promoter and as carer of AIDS patients was also examined. A self-administered questionnaire was used to collect data at two different time periods. The sample represented 729 nurses (at pre- and post-time periods), both qualified and student nurses. Qualified nurses reported the highest stress levels while student nurses reported more negative lifestyle practices such as smoking, alcohol consumption and drug use. A greater number of current smokers (29%) consumed alcohol and used drugs than non-smokers. The impact of intervention strategies around compliance with smoking policy and work-site walk routes reduced exposure to passive smoking at work for qualified nurses and increased exercise participation for both groups of nurses. Workplace was identified as the main source of stress which included relationships at work and demands of the job. Hospital nurses experiencing high work stress were more likely to use professional support and personal coping (discuss problems with friends/family, have a good cry and eat more) than others. Nurses believed in the importance of health promotion as part of their work; however, qualified nurses felt more confident and gave more health related information than student nurses. Student nurses perceived a lower risk of contacting AIDS through work and a higher concern/worry in caring for AIDS patients than qualified nurses.

Adaptation, Psychological↗
PubMed1997

Differentiation of Australian isolates of Mycobacterium paratuberculosis using pulsed-field gel electrophoresis.

OBJECTIVES: To examine strain variation amongst Australian isolates of Mycobacterium paratuberculosis. DESIGN: Pulsed field gel electrophoresis was optimised for differentiation of M paratuberculosis strains, and this typing technique was then applied to a collection of Australian isolates. PROCEDURE: DNAs from 35 Australian isolates of M paratuberculosis and a UK reference strain were digested with one or other of three restriction endonucleases. The banding patterns obtained after pulsed field gel electrophoresis of the DNA fragments were compared. RESULTS: The Australian isolates were divided into two groups on the basis of their DNA banding pattern. Both were different from the UK reference strain. Seven isolates from cattle in Victoria and the Northern Territory had the same pattern as five isolates from alpacas in Victoria and Western Australia. Another 20 isolates from cattle in Victoria, Western Australia and the Northern Territory had the same pattern as isolates from two sheep and a goat in New South Wales. CONCLUSION: Pulsed field gel electrophoresis was a useful tool for strain typing of M paratuberculosis, and could be used to study the transmission of strains in Australia.

Animals↗
PubMed1996

Chrysotile asbestos fibers mediate homologous recombination in Rat2 lambda fibroblasts: implications for carcinogenesis.

Asbestos fibers are widespread environmental carcinogens whose mutagenicity is now established. Nonetheless, the molecular nature of these mutations and the mechanisms by which they accelerate carcinogenesis remain poorly understood. We have assessed the ability of asbestos fibers to promote homologous recombination, a potent mechanism for generating intrachromosomal rearrangements, such as deletions, and mitotic recombination. For this, we have developed a new assay which determines the extent to which a marker gene present in DNA introduced by asbestos can recombine with homologous genes residing in a transfected cell. We have demonstrated that Calidria chrysotile fibers are mutagenic and are able to mediate transfection of molecularly marked mutant lacI genes in a manner that results in their preferential recombination with homologous wild-type genes in the transfected cell. Asbestos induced recombination events may play a significant role in asbestos mutagenesis and carcinogenesis, and promotion of recombination may underlie the well-recognized synergy of asbestos with other carcinogens.

Animals↗
PubMed1995

The molecular basis for the green-blue sensitivity shift in the rod visual pigments of the European eel.

When the European eel matures sexually and migrates back to deep sea breeding grounds the visual pigments in its rod photoreceptors change from being maximally sensitive to green light to being maximally sensitive to blue light. In part, this change in sensitivity is due to a change in the opsin component of the visual pigment molecule. We used hormone injection to induce these developmental changes in a group of eels and from these animals an opsin coding region was cloned and sequenced using cDNA made from retinal mRNA. From the retinae of hormone-injected eels and those not injected with hormones, distinct opsin mRNAs were isolated. These mRNAs encode two rod opsin proteins that are very similar but have significant amino acid substitutions in key positions that are likely to be involved in spectral tuning of the eel green and blue sensitive rod visual pigment molecules.

Amino Acid Sequence↗