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Biomedical subjects

L D Thomas

Publications and source records attributed to L D Thomas.

6 recordsLinked to original sources
PubMed2000

Catalase immunization from Pseudomonas aeruginosa enhances bacterial clearance in the rat lung.

Pseudomonas aeruginosa is a common cause of infection in immunocompromised patients and is the major contributor to morbidity in individuals with cystic fibrosis (CF). The antibiotic resistance shown by this pathogen and morbidity in patients with chronic infection has encouraged investigations into the development of a vaccine. This study reports the purification of a 60 kDa protein, isolated from a mucoid strain of P. aeruginosa, identified by amino acid sequence analysis as the catalase protein (KatA). A rat model of acute P. aeruginosa respiratory infection was used to investigate the immunogenicity of KatA and determine the potential of mucosal immunization with KatA to protect against infection. Immunization regimens compared a single intra-Peyer's patch (IPP) immunization with an IPP primary inoculation followed by an intratracheal boost to the lungs. Mucosal immunization with KatA resulted in significant pulmonary clearance of both homologous (p<0.001) and heterologous (p<0.05) strains of P. aeruginosa. Both immunization regimens enhanced bacterial clearance, increased the rate of recruitment of phagocytes to the bronchoalveoli and induced KatA-specific antibody. However, the regimen that included a boost induced a more effective immune response that also resulted in better clearance of P. aeruginosa from the lungs. Mucosal immunization induced KatA- specific antibodies in the serum and the bronchoalveolar lavage, and KatA-specific lymphocyte proliferation in vitro in cells isolated from the mesenteric lymph nodes of immunized rats. The data presented suggests that KatA has the potential to afford a protective immune response against pulmonary infection by P. aeruginosa

Animals↗
PubMed1997

Pills or therapy--which is better?

The debate about the strengths and limitations of psychotherapy in the treatment of depression has been bolstered in a critique by Mufioz et al (1994) of the US Agency for Health Care Policy and Research (AHCPR) 'Depression in Primary Care' guidelines. The author's evaluation of the guidelines suggest that psychotherapy alone is more effective than medication and that combined psychotherapy with medication is no more effective than psychotherapy alone. Such data has important implications for the management of depressions in Australia and provides support for the role of the nurse/therapist within the treatment team.

Antidepressive Agents↗
PubMed1996

Neuropsychological correlates of amyloid precursor protein in Alzheimer's disease.

The comprehensive cognitive screens for dementia, the Cambridge Cognitive screen (CAMCOG) and the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) were used for assessing use of the putative Alzheimer's disease biological marker, plasma amyloid precursor protein (APP), in Alzheimer's disease and Down syndrome. The analysis suggested that there were significant correlations between amyloid precursor protein and cognitive decline as assessed by the IQCODE. Preliminary investigations of Down syndrome suggest amyloid precursor protein levels are associated with duration of dementia in the group. The findings imply circulating amyloid precursor protein has a more central role in the pathogenesis of Alzheimer's disease.

Adult↗
PubMed1992

An abnormality of plasma amyloid protein precursor in Alzheimer's disease.

beta A4 amyloid deposition in the brain, which is characteristic of Alzheimer's disease (AD), may result from either overexpression of the amyloid protein precursor (APP) or failure of APP to be correctly processed. A blood marker reflecting this abnormal metabolism would be of diagnostic value and would provide a means of monitoring the efficacy of therapeutic interventions. We analyzed immunoblots of plasma APP enriched by heparin-Sepharose chromatography from patients with moderate to severe AD dementia (n = 34) and control subjects (n = 77) and found an approximately 50% increase in the proportion of 130-kd APP species in patients with AD (p less than 0.001), no difference in the 110-kd form, a 15 to 30% decrease in the 65-kd form (p less than 0.001), and a 20 to 35% decrease in the proportion of 42-kd APP (p less than 0.001). These species of APP were soluble, lacked the carboxyl terminus, and the 110- and 42-kd species were shown to be consistent with degradation products derived from the 130-kd species. A comparison of levels of 130-kd plasma APP from moderately to severely demented patients with AD and control subjects distinguished the two groups with a specificity of 87.0% and a sensitivity of 79.4%.

Alzheimer Disease↗
PubMed1991

Optimum doses of deuterium oxide and sodium bromide for the determination of total body water and extracellular fluid.

A practical approach for determining optimum tracer doses is described for measurements of total body water (TBW) and extracellular water (ECW) based on dilution of deuterium oxide and sodium bromide with respective analyses by nuclear magnetic resonance and anion-exchange chromatography. Using these techniques and plasma concentrations corresponding to adult doses up to 1.5 g kg-1 body weight of deuterium oxide and 0.05 g kg-1 of sodium bromide, the variations of analyses of these tracers, at these respective doses, were calculated. TBW determination with an RSD of less than 2% was found to require administration of 0.4 g kg-1 of deuterium oxide. Because basal concentrations of bromide are quantifiable, the accuracy of the extracellular water determination depends upon the magnitude of the increase in plasma bromide concentration; a sodium bromide dose of 0.01 g kg-1 provides a deviation in the determined ECW volume of approximately 1%.

Body Water↗