Biomedical subjects

N Strachan

Publications and source records attributed to N Strachan.

6 recordsLinked to original sources

PubMed2002

On-line microbial biosensing and fingerprinting of water pollutants.

The potential for biosensors to contribute to on-line toxicity testing for monitoring of water quality is currently constrained both by the relevance of the biosensors available and the technology for biosensor delivery. This paper reports the use of novel slow release biosensor delivery for on-line monitoring instrumentation, with environmentally relevant bacteria for both simple toxicity testing and more complex toxicity fingerprinting of industrial effluents. The on-line toxicity test, using bioluminescence-based biosensors, proved to be as sensitive and reliable as the corresponding batch test, with comparable contaminant EC(50) values from both methods. Toxicity fingerprinting through the investigation of the kinetics (dose-response) and the dynamics (response with time) of the biosensor test response proved to be diagnostic of both effluent type and composition. Furthermore, the slow release of biosensors immobilised in a polyvinyl alcohol (PVA) matrix greatly improved biosensor delivery, did not affect the sensitivity of toxicity testing, and demonstrated great potential for inclusion in on-line monitoring instrumentation.

Biosensing Techniques↗

PubMed2001

Soil solution extraction techniques for microbial ecotoxicity testing: a comparative evaluation.

The suitability of two different techniques (centrifugation and Rhizon sampler) for obtaining the interstitial pore water of soil (soil solution), integral to the ecotoxicity assessment of metal contaminated soil, were investigated by combining chemical analyses and a luminescence-based microbial biosensor. Two different techniques, centrifugation and Rhizon sampler, were used to extract the soil solution from Insch (a loamy sand) and Boyndie (a sandy loam) soils, which had been amended with different concentrations of Zn and Cd. The concentrations of dissolved organic carbon (DOC), major anions (F- , CI-, NO3, SO4(2-)) and major cations (K+, Mg2+, Ca2+) in the soil solutions varied depending on the extraction technique used. Overall, the concentrations of Zn and Cd were significantly higher in the soil solution extracted using the centrifugation technique compared with that extracted using the Rhizon sampler technique. Furthermore, the differences observed between the two extraction techniques depended on the type of soil from which the solution was being extracted. The luminescence-based biosensor Escherichia coli HB101 pUCD607 was shown to respond to the free metal concentrations in the soil solutions and showed that different toxicities were associated with each soil, depending on the technique used to extract the soil solution. This study highlights the need to characterise the type of extraction technique used to obtain the soil solution for ecotoxicity testing in order that a representative ecotoxicity assessment can be carried out.

Biological Assay↗

PubMed1999

Prescription and nonprescription drug use among at-risk community-dwelling seniors in Ottawa-Carleton.

BACKGROUND: The Council on Aging Ottawa-Carleton conducted an evaluation study aimed at reducing the inappropriate use of medication by community-dwelling seniors. During a 17-month period from 1990 to 1992, 278 of 415 seniors consented to participate. All were new referrals to home care, all were 65 years of age or older and all were taking a minimum of six prescription medications. OBJECTIVE: To describe the patterns of prescription and nonprescription drug use among high risk elderly people living in the Ottawa-Carleton region. ANALYSIS: Descriptive statistics and logistic regression were used to explore relationships between the numbers of drugs (prescription and nonprescription), drug classes and drug subclasses, and sex, age and number of prescribing physicians. RESULTS: The top 10 prescription or nonprescription drugs taken by study participants were consistent among diseases and health problems most commonly found among the elderly. Comparisons by rank for subclasses of drugs indicated that eye, ear, nose and throat (EENT), and respiratory drugs were considerably more prevalent among males than females, while women took more hormones and anxiolytics, sedatives and hypnotics. Age also appeared to have an effect; the proportions of respiratory drugs and hormones decreased with age. In contrast, vitamins and EENT drugs were most prevalent among the oldest seniors. These findings were supported by the results of multivariate analyses. Having three or more prescribing doctors was positively associated with the use of laxatives. Findings from multivariate analyses indicated that for prescription drugs, the youngest age group was about four times more likely than the oldest age group to be taking at least eight drugs. For nonprescription drugs, the only statistically significant finding was that those with three or more doctors were twice as likely as those with one or two doctors to take at least one nonprescription drug.

Aged↗

PubMed1997

Oculopharyngeal muscular dystrophy (OPMD)--report and genetic studies of an Australian kindred.

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset autosomal dominant disease. Due to a founder effect, it is most commonly found in the French Canadian population. The gene has recently been mapped to chromosome 14q11.2-q13 in some of these families. Here we report an Australian kindred of German descent with OPMD. Linkage analysis supports its locus to chromosome 14q. Repeat expansion studies were also carried out, but a CAG trinucleotide repeat expansion detected did not cosegregate with the disease. We conclude that there is no evidence of genetic heterogeneity or involvement of repeat expansion in OPMD.

Australia↗

PubMed1994

Familial testicular carcinoma: in search of genetic triggers.

Two cases of testicular tumours in non-twin brothers of a cancer-prone family are described. Cytogenetic studies of these two patients and human leucocyte antigen (HLA) typing of the family failed to identify any genetic defects. The authors propose using linkage analysis for further genetic studies but would require additional families for this to be performed.

Adult↗

PubMed1986

A family study of the prevalence of antibodies to the rheumatoid arthritis associated nuclear antigen (RANA).

Sera from families with at least two members suffering from seropositive rheumatoid arthritis (RA) were examined for the prevalence of antibodies to the RA associated nuclear antigen (RANA). It was found that consanguineous relatives of patients had a significantly increased prevalence of anti-RANA antibodies compared to sera from a control group of families. Anti-RANA antibodies were also significantly more prevalent in the sera of familial RA patients who possessed HLA-DR4. No correlation of anti-RANA antibodies with disease associated haplotypes was observed in these families.

Adult↗