Biomedical subjects

A Kingman

Publications and source records attributed to A Kingman.

75 records · Page 5Linked to original sources

PubMed1978

Double-blind trial of tetracycline in recurrent aphthous ulceration.

A double-blind trial of a tetracycline suspension was carried out in 25 patients with recurrent aphthous oral ulcerations. A combined topical-systemic treatment procedure was used. Both the placebo and tetracycline group experienced reductions in ulcer incidence during the treatment period, whereas only the tetracycline group showed significant reductions in ulcer duration, size, and pain. Tetracylcine treatment apparently alters the severity of the ulcer, but does not appear to affect those factors responsible for recurrences. The side effects recorded in patients taking tetracycline were comparable to those in patients on placebo.

Administration, Oral↗

PubMedDate not supplied

Cationic liposome-mediated gene transfer to rat salivary epithelial cells in vitro and in vivo.

BACKGROUND: Previously we have shown that gene transfer to salivary gland epithelial cells readily occurs via recombinant adenoviruses, although the response is short-lived and results in a potent host immune response. The aim of the present study was to assess the feasibility of using cationic liposomes to mediate gene transfer to rat salivary cells in vitro and in vivo. METHODS: Initially, for transfection in vitro, we used two cationic liposome formulations (GAP-DLRIE/DOPE and DOSPA/DOPE) complexed with plasmid encoding human growth hormone (hGH) as a reporter gene. Thereafter, using GAP-DLRIE/DOPE, plasmids were transferred to rat salivary glands in vivo, and hGH levels measured in saliva, serum and gland extracts. RESULTS: Under optimal conditions, transfection of rat submandibular glands (SMGs) was consistently observed. Approximately 95% of the cells transfected with a plasmid encoding beta-galactosidase were acinar cells. Maximal hGH expression was obtained during the first 48 h post-transfection using a plasmid encoding the hGH cDNA and complexed with GAP-DLRIE/DOPE. hGH was detected in gland extracts and saliva, and occasionally in serum. No systemic or local gland pathology was consistently or significantly observed. CONCLUSIONS: The levels of the reporter gene product, hGH, obtained after GAP-DLRIE/DOPE-mediated gene transfer are considerably lower (<0.5%) than those achieved with adenoviral vectors (10(8) PFU). Nonetheless, cationic liposome-mediated gene transfer to salivary glands may be useful for potential therapeutic applications.

Amylases↗

PubMedDate not supplied

Some power considerations when deciding to use transformations.

Conventional wisdom suggests that for small data sets having substantial skew, one should attempt to determine the correct distributional form, if possible, and apply statistical methods appropriate for that distribution. Transformations such as the log or square root are often used. If an appropriate distributional form cannot be determined, a distribution-free procedure such as a rank transformation or a randomization test procedure can be used. To better appreciate the effect of such alternatives on both the type I error and power of detecting differences between treatment groups, simulation studies were conducted for responses having specific gamma G(r, theta) and log-normal ln(M, V) distributions. The gamma and log-normal distributions were selected so that they had the same first two moments. A simple two group design was assumed. The reference group always had an average disease level mu = 3.0 (mu = r theta for gamma, mu = M for log-normal), and the treatment group always had means whose reductions ranged from 0 per cent to 50 per cent. The effect of distributional type and the degree of skewness was investigated by varying the population parameter values. Six statistical test procedures were compared for the gamma distributions. All test procedures were robust relative to the type I error. The UMP test based on a ratio of sample means produced the greatest power for all combinations of n, r and RT. The power losses associated with the randomization test, the t-test on original scale, and the t-test on the square root scale were very small, (3 per cent to 6 per cent in absolute value) for n = 10 and 15, and less than 2 per cent for group sizes of 25 or more. The power loss associated with the t-test on the log scale was much larger, ranging from 5 per cent to 10 per cent smaller power than the t-test on original scale. The Wilcoxon rank test produced similar results to that of the LOG t-test for small samples. The power for the shifted LOG (X+c) test increased monotonically to the asymptotic value of the ORIG t-test. The same five test procedures based on differences in sample means were then compared for the corresponding log-normal distributions. The UMP test, that is, LOG(X), produced the highest power. There was very little power lost for the SQRT t-test. The loss in power varied between 2 per cent and 5 per cent for the RANK test.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical Trials as Topic↗