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Biomedical subjects

R R Marples

Publications and source records attributed to R R Marples.

At least 73 records · Page 4Linked to original sources
PubMed1978

The dimensions of skin fragments dispersed into the air during activity.

There was a 1000-fold difference between the highest and the lowest mean rate of dispersal of bacteria-carrying particles during exercise among a group of three male and three female subjects. Differences in the numbers of skin fragments dispersed and in the proportion of these carrying bacteria were almost equally responsible for this. Since there is little difference between individuals in the rate of skin replacement the differences in the rates of dispersal of skin fragments during exercise must reflect large variations in the amount of skin surface removed in other ways. The skin fragments dispersed had a wide size range extending below 5 micrometer for the minimum projected diameter (MPD). The median MPD was about 20 micrometer with 7-10% less than 10 micrometer. Many of the particles could therefore pass freely through tightly woven fabrics with pores up to 10-15 micrometer which might seem to be impenetrable to whole corneocytes, typically larger than 30 X 40 micrometer in the hydrated state.

Air Microbiology↗
PubMed1978

Microbiology of normal and seborrheic canine skin.

Quantitative and qualitative bacterial assays were performed on the skin of 15 normal and 32 seborrheic dogs. Nonionic detergent scrubs were made on areas demarcated by glass sidearm cylinders. Quantitative analysis was accomplished by the serial dilution technique, and the bacteria were identified by individual and colonial morphology and by enzyme production. Areas measured on control dogs had a markedly lower total bacterial count than similar areas measured on seborrheic animals. Control dogs had a flora consisting primarily of coagulase-negative cocci, whereas seborrheic dogs usually had a cutaneous flora composed primarily of Stahylococcus aureus, coagulase-positive.

Animals↗
PubMed1978

Ivestigation of coagulase-negative staphylococci from infections in surgical patients.

All available isolates of coagulase-negative staphylococci from patients admitted to a unit for cardiac surgery during a 14-month period were examined. During this time 382 operations, in 220 of which a prosthetic valve was implanted, were performed. 65 patients suffered 76 episodes of postoperative infection. All coagulase-negative staphylococci isolated were classified by biochemical typing, bacteriophage typing and testing of anitbiotic susceptibility. The results of this investigation were reported and discussed especially from an epidemiological point of view.

Adult↗
PubMed1976

Ultrasonic methods for sampling human skin micro-organisms.

Methods of sampling the microflora of human skin by means of a generator of ultrasonic impulses were compared with the standard washing method in which the skin surface is rubbed manually. The ultrasonic method, at a power setting of 50 W or more, gave essentially similar results to those obtained by the standard method but removed fewer corneocytes.

Bacteriological Techniques↗
PubMed1975

Quantitative microbiology of the scalp in non-dandruff, dandruff, and seborrheic dermatitis.

The composition of the scalp microflora was assessed quantitatively in normal individuals and in patients with dandruff and seborrheic dermatitis, disorders characterized by increasing scaling. Three organisms were constantly found: (1) Pityrosporum, (2) aerobic cocci, and (3) Corynebacterium acnes. Pityrosporum (mainly Pityrosporum ovale) made up 46% of the total microflora in normals, 74% in dandruff, and 83% in seborvheic dermatitis. The geometric mean number of organisms per cm-2 in non-dandruff subjects was 5.04 times 10-5; 9.22 times 10-5 in dandruff subjects; and 6.45 times 10-5 in those with seborrheic dermatitis. The cocci were dominantly Baird-Parker type SII and no quantitative or qualitative change occurred in the scaling disorders. C. acnes comprised 26% of the flora on the normal scalp, 6% in dandruff, and only 1% in seborrheic dermatitis. These results differ significantly from previous reports which describe a much more complex microflora and suggest an etiologic role for microorganisms in dandruff.

Apicomplexa↗
PubMed1974

Methods for evaluating topical antibacterial agents on human skin.

Three procedures were presented for appraising the ability of antibacterial chemicals and formulations to suppress the growth of microorganisms on human skin. In each of these, the microflora was quantified after the skin had been occlusively covered for a day or more, a circumstance which, in the absence of a deterrent, led to an explosive overgrowth by resident organisms. The data obtained related to (i) the capacity to prevent expansion of the normal microflora, (ii) the suppression of an already expanded flora, and (iii) the persistence of antibacterial effect 3 days after the last application.

Administration, Topical↗