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Biomedical subjects

M Dobson

Publications and source records attributed to M Dobson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Field trial of oxygen concentrators in upper Egypt.

Technical problems in developing countries often require more than just technological solutions. Many small hospitals in rural areas are without a reliable oxygen supply; small oxygen concentrators offer a solution, but simply sending out machines is ineffective. This account details the setting up and first year's operation of a project to test oxygen concentrations in a developing country. A co-ordinated strategy has been developed to include machines, supplies, education, training, and feedback. Initial results are encouraging, and support the idea that suitably installed and maintained concentrations can have a valuable role in bringing oxygen therapy to patients and hospitals in countries which have so far been denied it.

Anesthesiology↗
PubMed1996

The Australian Vietnam Veterans Health Study: I. study design and response bias.

BACKGROUND: The Australian Vietnam Veterans Health Study was set up to examine the post-war health of former soldiers 20 or more years after service and to examine the relation of combat exposure to physical and mental health. METHOD: A prospective cohort study of a simple random sample of 1000 male Australian Army Vietnam veterans used information gathered from Army records, from personnel interview and questionnaires. Military records were used to examine response bias by determining the differences between 641 interviewed veterans, 50 known deceased veterans and 309 non-respondents (including 48 refusers and 213 non-traceable). RESULTS: Differences were evident between respondents and non-respondents, with logistic regression modelling pointing to pre-enlistment employment, antisocial behaviour, intelligence and post-Vietnam AWOL (absent without leave) as the most important discriminants with non-respondents performing worse. Compared to respondents, deceased left school earlier, had higher rank in Vietnam and at discharge, had a higher overall number of charges but not a higher rate overall, and were less likely to have gone AWOL. Deceased also received more casualty reports than respondents and non-respondents, were better behaved during service, and were better emotionally adjusted than non-respondents. Respondents compared with the Australian population had equivalent or better current socioeconomic status. CONCLUSION: There seems little bias due to non-response, but deceased tend to come from and older cohort than in the other two groups.

Adult↗
PubMed1996

The Australian Vietnam Veterans Health Study: II. self-reported health of veterans compared with the Australian population.

BACKGROUND: Self-reported physical health status of Australian Vietnam veterans was determined 20-25 years after the war and its relation to combat was investigated. METHOD: An epidemiological cohort study of a simple random sample of Army veterans posted to Vietnam between 1964 and 1972 was conducted with personal interviews using the Australian Bureau of Statistics Health Interview Survey questionnaire to compare veterans with the Australian population and a 21-item combat exposure index used to measure the relationship of combat to physical health. RESULTS: Veterans reported greater health service usage and more recent health actions than population expectations. They also reported excess health problems in almost all recent illness disease categories except endocrine conditions and cardiovascular conditions; only 6 of 37 chronic disease groups were not elevated compared to the population. Adjustment for non-response changed estimates only slightly. Combat exposure was significantly related to reports of recent and chronic mental disorders, recent hernia and chronic ulcer, recent eczema and chronic rash, deafness, chronic infective and parasitic disease, chronic back disorders and symptoms, signs and ill-defined conditions. CONCLUSION: Combat exposure may have significantly increased reports of only some health problems. A general position to complain as a result of psychological conditions due to combat is not consistent with the lack of relationship between combat and reports of physical conditions.

Adult↗
PubMed1996

The Australian Vietnam Veterans Health Study: III. psychological health of Australian Vietnam veterans and its relationship to combat.

BACKGROUND: Self-reported psychiatric status of Australian Vietnam war veterans was determined 20-25 years after the war and its relation to combat was investigated. METHOD: A simple random sample of Australian Army Vietnam veterans was interviewed nationally using standardized interviews and self-completion tests to assess the prevalence of lifetime and current psychiatric illness and its relationship to combat. Army records were used to extract data on the cohort for use in regression-based adjustment for non-response. RESULTS: The conditions mainly affecting the Australian veterans were alcohol abuse or dependence, post-traumatic stress disorder, somatization disorder were significantly related to combat exposure but not with posting to a combat unit. Less than half of the current one-month diagnoses were related to combat, possibly because of low power conferred by the relative rarity of these conditions. CONCLUSIONS: The results confirm a range of psychological problems in former warriors may linger 20 or more years from their war exposure and may be directly affected by exposure to war trauma.

Australia↗
PubMed1996

A randomised trial investigating the dose intensity of primary chemotherapy in patients with ovarian carcinoma: a comparison of chemotherapy given every four weeks with the same chemotherapy given at three week intervals.

BACKGROUND: The dose intensity of chemotherapy for patients with ovarian carcinoma remains a controversial issue. Few randomised trials have been conducted examining dose intensity using the same total dose of chemotherapy. This study was designed to investigate two schedules of chemotherapy using standard and higher dose intensity with both groups receiving the same total dose. PATIENTS AND METHODS: Patients with FIGO stage IC, II, III and IV epithelial ovarian carcinoma were randomised to receive cycles of cyclophosphamide (600 mg/m2) and carboplatin (300 mg/m2) alternating with doxorubicin (50 mg/ m2) and ifosfamide (5 g/m2) at either four-weekly (n = 47) or three-weekly (n = 97) intervals (1:2 randomisation). At randomisation patients were stratified according to histological grade and amount of post operative residual tumour (greater or less than 2 cm). The two arms of the study were well balanced in terms of the major prognostic features. RESULTS: There was no difference in either progression free survival or overall survival between the two arms. The median overall survival was 730 days for the three-weekly treatment and 740 days in the four-weekly arm (progression-free survival was 500 days and 483 days, respectively). The combined overall response rate (complete and partial response) in the 114 assessable patients was 65.7% (66.7% for the three-weekly treatment and 64% for the four-weekly treatment). These differences were not statistically different. CONCLUSIONS: A modest increase in the dose intensity of chemotherapy (1:3 fold) failed to improve the response rate, progression-free survival and overall survival in patients with ovarian carcinoma.

Adult↗
PubMed1996

Australian Vietnam veterans: factors contributing to psychosocial problems.

OBJECTIVE: The objective of the present paper is to present comprehensive models of the current psychosocial morbidity of Australian Vietnam veterans. Seldom has research in this area attempted to 'untangle' direct and indirect influences on current functioning via possible pre-army, Vietnam and homecoming pathways. METHOD: The Australian Vietnam Veterans' Health Study gathered data on a sample of 641 veterans throughout Australia drawn randomly from army Vietnam tour lists of the era. The data arose from interview and army records of the era, and fall into four temporal categories: pre-army, Vietnam service, homecoming after Vietnam, and current state. Path analysis models of the veterans' current psychological morbidities and social wellbeing are used to identify direct aetiological influences of earlier era constructs on current state, free of confounding by indirect (often selection) effects. RESULTS: Our results indicate that psychological morbidity (particularly posttraumatic stress disorder) is largely influenced by combat and poor homecoming experiences, although pre-military characteristics do play some direct roles in symptomatology. Social dysfunction measures show smaller effects of the Vietnam War, which may be accounted for by an indirect association with Vietnam-related psychological morbidity. Some social measures show evidence of compensatory influences of combat, high combat leading to social dysfunction because of morbidity, but simultaneously being associated with healthier social disposition (possibly because of increased exservice activity). CONCLUSIONS: For Australian Vietnam veterans, combat-related and homecoming effects persist on a range of psychosocial endpoints 20-30 years after exposure. These effects are not explicable in terms of veterans pre-Vietnam characteristics.

Adolescent↗
PubMed1993

Measuring utility values for QALYs: two methodological issues.

Two methodological concerns in utility estimation, the development of health state descriptions (scenarios) and the interpretation of interval scale anchor points, are examined in the context of disease-specific cost utility analyses (CUA). It is contended that results in CUA can be fundamentally biased by: (i) how the information presented in a scenario is generated; and (ii) the researcher's 'definition' of anchor points, when these are used as bounds to the interval scale. A number of recommendations are made, in particular for a more explicit reporting of these issues in CUA, to facilitate greater consistency in the application of utility measurement techniques.

Cost of Illness↗
PubMed1993

Framing and labelling effects in health descriptions: quality adjusted life years for treatment of breast cancer.

At present there is a growing interest in the use of cost-utility analysis (CUA) to a point where it merits serious consideration by health care decision makers. However, there remain a number of theoretical and practical issues to be resolved including the way in which quality of life information is presented and described to subjects. Two potential sources of influence in the construction of the quality adjusted life year (QALY) values elicited for a recent Australian CUA of mammography screening have been investigated. 180 subjects were randomly allocated to nine different presentations of two breast cancer health descriptions to investigate the impact of some framing and labelling effects. No statistically significant differences were found in the valuations placed on these descriptions when framing and labelling effects were taken into account, either as separate framing and labelling factors or as interactions with one another. A significant difference was found in the particular values of descriptions that were written in the third person that differed in terms of whether the word "cancer" was used. The main contribution of these data is to the robustness of the health descriptions used in the cost-utility analysis of mammography screening.

Aged↗
PubMed1993

Imagery ability and source monitoring: implications for eyewitness memory.

The present study investigated the effect of self-reported vividness of visual imagery on the ability to discriminate between memories derived from two external sources of information. Subjects were shown a film of a crime and were then given a written description of the event which included information not seen in the film. In a source monitoring task, high and low imagers were found to be equally proficient in recognizing items as previously presented, but high imagers were poorer at discriminating the source of items based on the written description. This finding is considered in terms of possible encoding and retrieval differences resulting from imagery vividness. The role of vivid visual imagery as a variable underpinning confusions in eyewitness testimony is discussed.

Cues↗
PubMed1992

Searching for synaptonemal complex proteins and their genes.

As an alternative to the production and use of monoclonal antisynaptonemal complex (SC) antibodies to isolate SC genes, we have explored the use of polyclonal anti-SC antibodies to identify SC genes from a cDNA expression library. The method proved relatively simple, reliable, and fast and has yielded two SC genes. A homologue of one of these genes from a different species has previously been isolated in another laboratory.

Animals↗
PubMed1992

Individual differences in anxiety level and eyewitness memory.

The present study investigated the relationship between individual differences in anxiety and eyewitness performance. Instructions designed to produce evaluative threat were given to anxious and nonanxious subjects at encoding and/or at retrieval. The performance of those subjects who were given anxiety-arousing instructions at encoding and retrieval and who scored high on the Test Anxiety Scale (TAS; Sarason, 1972) was less accurate on an eyewitness task than was that of the subjects who scored low on the scale. This difference in performance was attributable to improvement in the performance of nonanxious subjects, rather than debilitation in the performance of anxious subjects. Faced with the threat of failure, low-anxious subjects appeared to have the potential for increased effort. High-anxious subjects seemed to perform at or near capacity under all the experimental conditions because of their predisposition for task-irrelevant worry, which limited the possibility of an increase in working memory capacity.

Adult↗
PubMed1990

Expression of the Aspergillus niger glucose oxidase gene in A. niger, A. nidulans and Saccharomyces cerevisiae.

We report the cloning of the Aspergillus niger glucose oxidase gene and its use to elevate glucose oxidase productivity in A. niger by increasing the gene dosage. In addition, the gene has been introduced into A. nidulans where it provides the novel capacity to produce glucose oxidase. A plasmid, in which DNA encoding the mature form of glucose oxidase was preceded by a Saccharomyces cerevisiae secretion signal, effected high-level production of extracellular glucose oxidase in this yeast.

Amino Acid Sequence↗
PubMed1988

Purification and partial characterization of a plasminogen activator inhibitor from the human glioblastoma, U138.

A plasminogen activator inhibitor was purified to apparent homogeneity from conditioned media of U138 cells. The inhibitor is a glycoprotein with a pI of 5.4 and an apparent molecular weight of 45,000. The inhibitor forms sodium dodecyl sulfate-stable complexes with plasminogen activators and trypsin but not with plasmin, thrombin, or pancreatic kallikrein. Some biochemical and immunochemical characteristics of the U138 inhibitor distinguish it from other known plasminogen activator inhibitors. The expression of this inhibitor by U138 cells could be modulated by incubation in phorbol myristate acetate, interleukin-1, tumor necrosis factor, and gamma interferon, but not in beta interferon. Thus, the expression of the plasminogen activator inhibitor can be influenced by biological response modifiers known to be active in the brain and in the neural response to inflammatory stimuli. Therefore, this inhibitor, along with protease nexin, may be involved in brain development and regulation.

Autoradiography↗