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Biomedical subjects

D Griffiths

Publications and source records attributed to D Griffiths.

100 records · Page 6Linked to original sources

Avoidance-modified generalised distributions and their application to studies of superparasitism.

Given an underlying distribution for the number of encounters between parasites and a host this may be generalised by the distribution of the number of eggs per encounter. If eggs are already present, a parasite may avoid oviposition at subsequent encounters. A class of avoidance-modified generalised distributions is presented to model such situations. The case of a solitary (single egg-laying) parasite and a Poisson distribution for the number of encounters gives rise to a distribution of particular interest. Various properties of this distribution are derived and alternative estimation procedures investigated. Estimators based on the method of mean and zero frequency are shown to have the dual advantages over other estimators that have been proposed of simplicity of computation and increased efficiency. Over a wide range of parameter values there is virtually no loss of efficiency in comparison with maximum likelihood estimation.

Animals↗

Rathke-cleft cyst.

A patient is reported who presented with signs of hypopituitarism. On surgical exploration, she was found to have an intrasellar cyst containing creamy mucoid substance resembling pus. Microscopic examination revealed the lesion to be a Rathke-cleft cyst. These rare lesions are associated with a better prognosis than the typical craniopharyngioma. The distinguishing features between a Rathke-cleft cyst and a craniopharyngioma are discussed.

Adolescent↗

Twenty four-hour monitoring of incontinence and bladder function in a community hospital.

We wished to determine whether 24-hour monitoring of urinary incontinence without video urodynamics would provide adequate information for treatment. Twelve subjects with urinary incontinence (seven women and five men) were investigated, average age 75 years (range 44 to 89 years). Setting was a community hospital (80 beds), a nursing home, and a lodge, 60 miles from the nearest assessment center. Twenty four-hour monitoring consisted of 2 hourly preweighed pad changes, postchange weighing, Uroflow set-up in subject's bathroom, fluid intake record, and 1 postvoid residual ultrasonogram. All subjects had history and physical and evaluation of medications. Findings included probable urge incontinence, stress incontinence, chronic retention with overflow, and normal bladder function. Recommendations included oxybutynin chloride, timed toileting, timed fluid restriction, diuretic manipulation, intermittent catheterization, pessary, and surgery. At 6 weeks, 25% (4/12) were better (three with urge incontinence and one after operation for stress incontinence). Video urodynamics were conducted only for the patient with stress incontinence after operation. We suggest that 24-hour monitoring is noninvasive, is less disruptive and less expensive than video urodynamics, and provides adequate information for initial treatment in many patients with urinary incontinence.

Adult↗