Biomedical subjects

M Collinson

Publications and source records attributed to M Collinson.

8 recordsLinked to original sources

PubMed2007

Piezoelectric generators for biomedical and dental applications: effects of cyclic loading.

This paper presents the results of a study of the effect of cyclic loading parameters on the performance of piezo crystals. The output power of the crystals was observed to increase with parameters such as the cyclic frequency and the dynamic load range. However, the output power also decreased with increasing mean load. The efficiency of the crystal was calculated based on the mechanical energy applied to the piezo crystal. The ratio of the electrical output to mechanical energy input was taken as the efficiency of the crystal. This ratio was seen to increase with the cycling frequency, and also with the dynamic load range. However, increasing mean load caused the efficiency to drop significantly. The implications of the results are discussed for possible applications implanted bioMEMS and microelectronics systems.

Biomechanical Phenomena↗

PubMed2004

Undiagnosed pulmonary tuberculosis deaths in rural South Africa.

This research explores death from pulmonary tuberculosis (PTB) using a verbal autopsy (VA) tool within the established Agincourt Health and Demographic Surveillance System site in South Africa's rural northeast. Previous work on active case finding in the area highlighted a modest burden of undiagnosed PTB in the community. This VA research confirms the existence of undiagnosed PTB deaths, with 13 (46%) of 28 PTB deaths among the permanent adult population (n = 38,251) going undetected by the health service. There was a median duration of coughing in the community of 16 weeks among these undiagnosed PTB deaths. As most undiagnosed cases present to the health service at some point during their illness, intervention strategies to support early diagnosis at this level can only be re-emphasised by this work.

Adult↗

PubMed2002

Molecular epidemiological analysis of community circulating respiratory syncytial virus in rural South Africa: Comparison of viruses and genotypes responsible for different disease manifestations.

Human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infection in children in both the industrialized and developing world. Most molecular epidemiological studies have, until now, focused on isolates from hospitalized infants in industrialized countries. Limited data have been available with regard to community circulating RSV, especially from Africa. The present study compares RSV isolates from infants attending rural community clinics in the Northern province of South Africa, with isolates from hospitalized infants in Soweto, near Johannesburg, South Africa, during the same period. A multiplex nested polymerase chain reaction was developed for analyzing the clinical specimens, a technique that permits subtyping and nucleotide sequence analysis of the second variable region of the G-protein gene. Community- and hospital-based isolates from young children in South Africa, as well as isolates from Mozambique were compared phylogenetically. One subgroup B community isolate was identified that had a G-protein truncated by approximately 35 amino acids, however, the other community isolates were not significantly different from hospital isolates. Evidence was found that the same RSV genotypes and viruses could cause mild upper respiratory tract infections or lower respiratory tract infections or severe RSV in young infants.

Amino Acid Sequence↗

PubMed1999

Evaluating computerized health information systems: hardware, software and human ware: experiences from the Northern Province, South Africa.

Despite enormous investment world-wide in computerized health information systems their overall benefits and costs have rarely been fully assessed. A major new initiative in South Africa provides the opportunity to evaluate the introduction of information technology from a global perspective and assess its impact on public health. The Northern Province is implementing a comprehensive integrated hospital information system (HIS) in all of its 42 hospitals. These include two mental health institutions, eight regional hospitals (two acting as a tertiary complex with teaching responsibilities) and 32 district hospitals. The overall goal of the HIS is to improve the efficiency and effectiveness of health (and welfare) services through the creation and use of information, for clinical, administrative and monitoring purposes. This multi-site implementation is being undertaken as a single project at a cost of R130 million (which represents 2.5 per cent of the health and welfare budget on an annual basis). The implementation process commenced on 1 September 1998 with the introduction of the system into Mankweng Hospital as the pilot site and is to be completed in the year 2001. An evaluation programme has been designed to maximize the likelihood of success of the implementation phase (formative evaluation) as well as providing an overall assessment of its benefits and costs (summative evaluation). The evaluation was designed as a form of health technology assessment; the system will have to prove its worth (in terms of cost-effectiveness) relative to other interventions. This is more extensive than the traditional form of technical assessment of hardware and software functionality, and moves into assessing the day-to-day utility of the system, the clinical and managerial environment in which it is situated (humanware), and ultimately its effects on the quality of patient care and public health. In keeping with new South African legislation the evaluation process sought to involve as many stakeholders as possible at the same time as creating a methodologically rigorous study that lived within realistic resource limits. The design chosen for the summative assessment was a randomized controlled trial (RCT) in which 24 district hospitals will receive the HIS either early or late. This is the first attempt to carry out an RCT evaluation of a multi-site implementation of an HIS in the world. Within this design the evaluation will utilize a range of qualitative and quantitative techniques over varying time scales, each addressing specific aims of the evaluation programme. In addition, it will attempt to provide an overview of the general impact on people and organizations of introducing high-technology solutions into a relatively unprepared environment. The study should help to stimulate an evaluation culture in the health and welfare services in the Northern Province as well as building the capacity to undertake such evaluations in the future.

Computers↗

PubMed1999

Delivery of non-surgical oncology care.

The changes and options for future change in the provision of non-surgical oncology care within the UK are discussed in the context of the recommendations of the Calman report, the drive towards site specialization and the changing nature of the specialties of clinical and medical oncology. Options for the creation of an improved and more flexible service are discussed.

Humans↗

PubMed1997

Two enhancer domains control early aspects of the complex expression pattern of Msx1.

To understand how the complex embryonic expression pattern of the Msx1 gene is produced a transgenic analysis of 13 kb of DNA around the Msx1 locus was carried out. Most of the extensive expression pattern of the Msx1 gene was reproduced in transgenics using the LacZ gene fused to 5 kb of Msx1 5' flanking DNA. Two enhancer domains were identified which produced this pattern. The distal element produced expression in the first arch and the nasal epithelium and was restricted to 240 bp. However, the proximal element which produced expression in superficial nasal epithelium, dorsal and ventral myotome, limb mesenchyme, eye, ear, roof plate, second arch, genital ridge and epiphysis, was contained in only 78 bp.

Animals↗

PubMed1994

Intravenous pamidronate: infusion rate and safety.

In view of previous animal studies showing that pamidronate (Aredia) can cause renal damage, and human data indicating that pamidronate in doses of 60-90 mg is more effective in the control of tumor-induced hypercalcemia than when given at lower doses, we decided to investigate whether pamidronate 90 mg infused over 60 minutes at weekly intervals had any adverse effects on renal function in patients with bone metastases. Twelve patients, 7 female (all with breast cancer) and 5 male (4 with prostate cancer, 1 with bladder cancer) were entered into the trial. Each patient received weekly intravenous infusions of pamidronate 90 mg in 250 ml normal saline over 60 minutes for 4 weeks. 51Cr-EDTA clearances showed no significant changes in renal function. Urinary N-acetyl-B-D-glucosaminidase/creatinine ratios fluctuated considerably, but no consistent changes were found. No patient with a normal level of urinary beta 2-microglobulin had elevated levels at the end of the trial. Serum creatinine levels did not change significantly, though 1 patient had a corrected serum calcium level of < 2 mmol/L on a single occasion on day 8. No evidence of renal toxicity was detected. However, the possibility that neprohtoxicity would ultimately appear cannot be excluded, and these favourable short-term results cannot be extrapolated to patients with impaired renal function.

Adult↗

PubMed1991

Evaluation of blood pressure screening at the Alexandra Health Centre.

A review of patient registers and records at the Alexandra Health Centre and University Clinic (AHC) revealed that less than 10% of the expected number of hypertensive subjects in Alexandra are attending the twice a week hypertension clinic. In the adult outpatient department most patients are not screened for hypertension. Patients are more likely to be screened if they have symptoms suggestive of high blood pressure and are seen in the morning by a primary health care nurse. Age and sex of patients are not important determinants of hypertension screening. It is thus apparent that primary care consultations at the AHC are not used as opportunities for screening for a serious and common illness for which there is ready treatment. However, before the AHC embarks on a massive case-finding programme there is a need to develop efficient and affordable treatment programmes.

Adolescent↗