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Biomedical subjects

M A Hamilton

Publications and source records attributed to M A Hamilton.

83 records · Page 5Linked to original sources
PubMed1977

The treatment and prevention of chronic otorrhoea in the Northland health district.

The operation of a mobile ear clinic within the school medical service in Northland is described. The major justification for the use of a sophisticated unit lies in the opportunity which it affords for the education of children and adults on aural health. The higher costs of treatment may well be more than offset by the long-term benefits resulting from increased awareness and better understanding in our population on the causation of supporative otitis media.

Child↗
PubMed1976

New assay of protective activity of Rocky Mountain spotted fever vaccines.

Areas under the fever curves of guinea pigs inoculated with Rocky Mountain spotted fever vaccine over a restricted dose range and infected with a standardized dose of Rickettsia rickettsii varied linearly with log10 dose of vaccine. A calculator was programmed to plot fever curves and calculate the vaccine dose that reduced the fever of infected animals by 50%.

Animals↗
PubMed1975

Statistical inferences about injury and persistence of environmentally stressed bacteria.

A standard technique for ascertaining the survival characteristics of bacteria after being environmentally stressed is to incubate the bacteria on both selective and non-selective media and count the colonies produced. Based on these colony counts, indexes of injury and persistence of the bacteria are calculated. To compare the stress of two different environments, a persistence ratio is calculated. In this paper, methods of statistical inference concerning these indexes and ratios are presented. These statistical methods use well-known procedures for analysis of binomial data and 2 times 2 table data, and are appropriate when the colony counts follow a Possion distribution.

Bacteria↗
PubMedDate not supplied

Repeatability and reproducibility of germicide tests: a literature review.

The results of a quantitative antimicrobial assay can be summarized by the log reduction value. For an assay to be proposed as a standard method, it is usually necessary to conduct a collaborative study to demonstrate that the repeatability and reproducibility standard deviations (SDs) of the log reduction values are sufficiently small. It is not clear, however, precisely how small those SDs should be. This paper describes the results of a literature review conducted to determine the range of repeatability and reproducibility SDs for standard quantitative antimicrobial assays. The underlying premise is that, for an assay to have been accepted as a standard method, its repeatability and reproducibility SDs must have been sufficiently small. This premise implies that the repeatability and reproducibility SDs of standard assays establish de facto guidelines for acceptability. The survey comprised papers where the SDs could be extracted directly or where they could be calculated from accessible data. Papers describing suspension tests as well as hard surface tests were included. For the standard antimicrobial assays reviewed, repeatability SDs ranged from 0.25 to 1.21 and the reproducibility SDs ranged from 0.31 to 1.54.

Anti-Bacterial Agents↗
PubMedDate not supplied

The life stages of weight: setting achievable goals appropriate to each woman.

Weight is a preoccupation in America, especially among women. Using body mass index (BMI) as the measure, many women are found to be overweight (BMI 25-30 kg/m2) or obese (BMI >30 kg/m2). A BMI that is less than 18.5 kg/m2 reflects underweight, which is best considered separately. This paper is concerned with the classification of body weight, the distribution of body fat, and the nutritional, medical, and stage-of-life factors that affect fat deposition and weight. The main stages of life in regard to adiposity are the prenatal period, infancy and the period of adiposity rebound (childhood), adolescence, and finally adulthood, with some special considerations at and after menopause.

Adult↗
PubMedDate not supplied

Hard surface carrier test as a quantitative test of disinfection: a collaborative study.

The hard surface carrier test (HSCT) recently was proposed as a qualitative test for disinfectant efficacy. A collaborative study of HSCT led to a suggested performance standard of < or = 2 or 3 positive carriers out of 60 tested. Subsequently, it was discovered that HSCT can be used as a quantitative test, because the HSCT protocol requires measurement of inoculum level on some carriers. The data allow estimation of the log10 reduction in number of active bacteria. Producers, consumers, and policymakers will be better able to discuss merits of alternative performance standards if the focus is on log reduction of organisms rather than on number of positive carriers. Data from the collaborative study were reanalyzed from this quantitative viewpoint. If the point estimate of log reduction in LR and the 99% lower confidence limit estimate is LLR, the LR values ranged from 7.0 to 9.0 and the LLR values were greater than 6.0 for all disinfectants except the negative control formulation. The total variance for estimated LR is the sum of interlaboratory and intralaboratory variances. The total variance for LR was 0.095 for Pseudomonas aeruginosa, 0.251 for Staphylococcus aureus, and 0.118 for Salmonella choleraesuis. Percentages of the variance due to interlaboratory variability were 11% for P. aeruginosa, 52% for S. aureus, and 25% for S. choleraesuis. Chances of making false-effective and false-ineffective decisions can be calculated for the quantitative HSCT. The performance standard can be based on LLR.

Analysis of Variance↗