Search PubMed⌕ Search

Biomedical subjects

C M Stewart

Publications and source records attributed to C M Stewart.

47 records · Page 3Linked to original sources
PubMed1983

A standardized monitor for the control of ethylene oxide sterilization cycles.

The resistance of spores of B. subtilis var. niger produced in liquid synthetic medium and exposed to ethylene oxide on a nylon surface, has been shown to the almost identical to that for spores produced on a traditional solidified complex medium with exposure to the sterilant on aluminium foil. The use of short lengths of nylon tube as carriers allowed easy production and handling, with self-protection of the spore-bearing surface. Addition of a dye provided visual evidence of inoculation without affecting resistance to ethylene oxide. Such a monitor is suitable for use as a standardized biological challenge in routine ethylene oxide sterilization cycles.

Bacillus subtilis↗
PubMed1980

Effects of cholesterol on lipid organization in human erythrocyte membrane.

The molar ratio of cholesterol to phospholipid (C/P) in human erythrocyte membrane is modified by incubating the cells with liposomes of various C/P ratios. The observed increase in cell surface area may be accounted for by the addition of cholesterol molecules. Fusion between liposomes and cells or attachment of liposomes to cells is not a significant factor in the alteration of C/P ratio. Onset temperatures for lipid phase separation in modified membranes are measured by electron diffraction. The onset temperature increases with decreasing C/P ration from 2 degrees C at C/P = 0.95 to 20 degrees C at C/P = 0.5. Redistribution of intramembrane particles is observed in membranes freeze-quenched from temperatures below the onset temperature. The heterogeneous distribution of intramembrane particles below the onset temperature suggests phase separation of lipid, with concomitant segregation of intramembrane protein into domains, even in the presence of an intact spectrin network.

Cholesterol↗
PubMed1978

Effects of intermaxillary elastic traction on orthodontic tooth movement.

Intermaxillary elastics are commonly used in orthodontic treatment, yet the exact mechanism by which they effect tooth movement has been unclear. A photoelastic model was produced to stimulate this type of therapy in examples of Class II and III malocclusions. In the open situation, inter-arch activity precipitated occlusal plane rotation; counter clockwise in Class II malocclusion and clockwise in Class III. Comment is made on the force vectors involved when using intermaxillary elastics.

Dental Stress Analysis↗
PubMedDate not supplied

Comparison between saliva stimulants and a saliva substitute in patients with xerostomia and hyposalivation.

The purpose of this study was to assess patient preference and product efficacy of three non-prescription products for the symptomatic relief of xerostomia. The study group consisted of 80 individuals with a complaint of chronic (> six months) xerostomia and an unstimulated salivary flow rate of < 0.1 mL/min. The three products--a sorbitol/xylitol-sweetened chewing gum, a sorbitol-sweetened sour lemon lozenge, and a sorbitol/xylitol-sweetened artificial saliva substitute spray--were assigned in a permuted block randomization scheme. Each product was used for two weeks with an interval of one week between trials. The study did not identify any product to be statistically significant in terms of patient preference. Kruskal-Wallis testing revealed no statistical significance (P > 0.589) among the products. No product demonstrated marked efficacy in stimulating salivary output. ANOVA analysis followed by Tukey HSD testing revealed no significant difference between the baseline paraffin-stimulated mean flow rate and the gum- and lozenge-stimulated flow rates.

Adult↗
PubMedDate not supplied

Assessment of bromhexine as a treatment regimen in Sjögren's syndrome-like disease in the NOD (non-obese diabetic) mouse.

OBJECTIVE: Bromhexine has been reported to alleviate the xerostomia and xerophthalmia associated with secondary Sjögren's syndrome. The aim of this study was to determine if it might prove useful in the treatment of Sjögren's syndrome-like disease of the NOD mouse model for autoimmune sialoadenitis. METHODS: Groups of mice were divided into sets receiving 60 mg/kg bromhexine in drinking water and control pair-fed animals. The efficacy of drug treatment was assessed by weekly measurement of stimulated saliva volumes, protein concentration, and amylase activity. At termination (20 weeks) submandibular and lacrimal glands were removed to assess the levels of lymphocytic infiltration by histological evaluation under light microscopy. RESULTS: Control and bromhexine-treated groups of mice showed no difference in the loss or rate of reduction in stimulated saliva flow over the 12 weeks of treatment. No differences were noted in the protein concentration and amylase loss with increasing age of the animals. Similar temporal changes in total protein profiles and aberrant expression of the 20 kDa parotid secretory protein isoform were observed by SDS-polyacrylamide gel profiles and Western bolt analysis. Histological evaluation of exocrine gland sections failed to detect any reduction in focal lymphocyte infiltration. CONCLUSION: Bromhexine therapy did not alter the development or severity of Sjögren's syndrome-like disease in the NOD mouse model for autoimmune sialoadenitis.

Amylases↗