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Biomedical subjects

R Marks

Publications and source records attributed to R Marks.

At least 325 records · Page 18Linked to original sources
PubMed1986

Squamous cell carcinoma of the skin. Accuracy of clinical diagnosis and outcome of follow-up in Australia.

The accuracy of the clinical diagnosis of 1292 non-melanotic skin tumours that were submitted to a private pathology service in 1980-1981 was determined. The clinical diagnosis that was written on the pathology slip which was submitted with the tumour was correlated with the histological diagnosis and the type of medical practitioner submitting the lesion. The clinical diagnosis was most accurate in the case of basal cell carcinoma; dermatologists most often reached this diagnosis correctly. For squamous cell carcinoma, although most frequently the lesions were diagnosed correctly clinically by dermatologists, their clinical diagnosis was confirmed in only 51% of cases. On average, 36% of squamous cell carcinomas were diagnosed clinically as basal cell carcinomas. The clinical course of 299 patients with a total of 305 squamous cell carcinomas that were selected from the squamous cell carcinomas that were submitted in 1980-1981 was traced. Four tumours (1.6%) which occurred in sun-exposed areas of the body metastasized, and 18 (7.5%) recurred locally. We conclude that those non-melanotic skin tumours which have the most potential to metastasize (squamous cell carcinomas) are those which are most poorly diagnosed clinically. It is recommended that patients with non-melanotic skin cancers should undergo biopsy as a routine to confirm the clinical diagnosis. Those who have a squamous cell carcinoma removed should be followed up for at least two years after the initial treatment.

Adult↗
PubMed1986

A fluorescence NK assay using flow cytometry.

A flow cytometric NK assay was developed in which the K562 targets were labelled with the fluorogenic substrate, carboxyfluorescein diacetate (c'FDA). This new assay compared favourably with results obtained using the conventional 51Cr-release assay. c'FDA was not toxic to target cells and did not inhibit lysis. The assay permits the evaluation of various aspects of NK activity such as the activity of NK-enriched, IFN-alpha-activated, and ALG-inhibited populations. The assay can be used in place of 51Cr-release, and has the advantages of being able to directly monitor target cell lysis of reducing overall assay time, and the avoidance of radioisotope usage.

Adult↗
PubMed1986

Techniques for assessing the activity of topically applied retinoids.

The retinoid drugs have profound effects on many aspects of skin biology. The exact activity profile depends on the particular analog and its route of administration. The topical retinoids used at present have marked therapeutic effects on epidermal cell production and desquamation. All-trans-retinoic acid (tretinoin) also acts on dermal connective tissue and microvasculature in a way that is less well established but may also be of therapeutic benefit. We investigated both tretinoin and motretinide in normal subjects and in patients with ichthyosis. The quantitative dansyl chloride test has been particularly useful in monitoring the desquamatory action of these topically applied retinoids. Both compounds resulted in enhanced rates of epidermopoiesis and desquamation. Marked changes in the cytochemical profile of the epidermis were also detected, changes that differed somewhat from the alterations induced by the systemic administration of etretinate. Changes in dermal structure and vascularization were monitored by A-scan ultrasound and laser Doppler flowmetry. However, only minor changes were recorded, probably because of the comparatively short application time. These newer techniques for investigating skin structure and function offer considerable opportunities for delineating the action of retinoids.

Administration, Topical↗
PubMed1986

Hair follicle-like change over histiocytomas.

Epidermal hyperplasia is a common finding overlying histiocytomas. Occasionally, a distinctive type of basaloid hyperplasia occurs, with differentiation into primitive hair follicle tissue. This study attempts to characterize this change and determine whether it is associated with any particular clinical or histological feature. Data from patients with histiocytomas displaying induction of pilar epithelium in the epidermis above the lesions was compared with data from controls who did not show this change. The size, site, and duration of histiocytomas were similar in both groups, as were the predominant cell type and distance of histiocytoma from the epidermis. Serial sectioning of histiocytomas showed that the induction of pilar epithelium was a focal phenomenon, often missed in routine sections. It is suggested that histiocytoma cells may produce a "hair organizing mediator."

Epidermis↗
PubMed1986

The effects of an aromatic retinoid (etretinate) on epidermal cell production and metabolism in normal and ichthyotic patients.

Normal subjects and ichthyotic patients were biopsied before and after etretinate (Tigason) therapy. Histometric and cell kinetic measurements showed minimal changes following treatment. The metabolic activity across the epidermis was measured by a novel approach using the Quantimet 720 image analyser, and was significantly increased in the normal subjects as demonstrated by glucose-6-phosphate dehydrogenase (G6PDH), succinic dehydrogenase (SDH) and non-specific esterase (NSE) activities. In the ichthyotics studied the levels of G6PDH and SDH activity were significantly lowered following etretinate therapy, to levels similar to those demonstrated in normal subjects. In contrast, the activity of NSE was increased in the ichthyotics after etretinate therapy. It is suggested that the effect of retinoids is to 'normalize' the process of epidermal differentiation when it is abnormal.

Adult↗
PubMed1986

Spontaneous remission of solar keratoses: the case for conservative management.

One thousand and forty people aged 40 years and over, 616 (59.2%) of whom had solar keratoses, were followed for 12 months. Two hundred and twenty-four people (36.4%) had a spontaneous remission of at least one of their solar keratoses. A total of 485 lesions (25.9%) underwent spontaneous remission out of the 1873 lesions that were present at the first examination of these 224 people. There was no significant difference between the number of lesions present at the initial examination in those who had a spontaneous remission compared with those who did not. There was a 21.8% increase in the total number of solar keratoses in the 1040 people studied in the 12-month period, due to new lesions forming at the same time as remissions were occurring. The incidence rate of squamous cell carcinoma occurring in the people with solar keratoses was 0.24% for each solar keratosis present at the original examination. With a substantial proportion of solar keratoses remitting spontaneously, plus the low rate of malignant transformation and the low potential for metastasis to occur from squamous cell carcinoma arising in a solar keratosis, the rationale of treating all solar keratoses appears questionable.

Adult↗
PubMed1986

Clinical evaluation of fenticonazole cream in cutaneous fungal infections: a comparison with miconazole cream.

A randomized, double-blind, parallel-group, multi-centre clinical trial was undertaken in 60 patients with dermatophytosis or pityriasis versicolor to compare topical 2% fenticonazole cream with topical 2% miconazole cream. Treatment, by twice-daily application, was for 4 weeks or until earlier complete resolution of disease. Assessment was by laboratory mycological investigation and regular clinical/symptomatic evaluation, both during and for 2 to 6 weeks after therapy. Fifty-three patients satisfactorily completed the trial, 28 of whom received fenticonazole and 25 miconazole. The groups were adequately well-matched. All assessment criteria showed fenticonazole to be at least as efficacious as miconazole, with no statistically significant differences between the two treatments. A number of assessment criteria, however, did show trends in favour of fenticonazole. Fenticonazole resulted in mycological findings becoming negative in 92%, i.e. all but 2 of 25 patients, by the end of treatment and a similar proportion (91%, 21 of 23 patients) remained mycologically negative 2 to 4 weeks after the end of therapy. With miconazole, only 79% (19 of 24 patients) became mycologically negative during treatment and this figure decreased further to 74% (14 of 19 patients) after therapy. Essentially similar results were seen for clinical assessments of erythema, itching and desquamation, these features being significantly and progressively eliminated or improved by both treatments in high proportions of patients during therapy, followed by little tendency to return after the cessation of therapy. Overall clinical assessments demonstrated statistically significant improvement during the second, third and fourth weeks of treatment with both drugs. Only 4 patients (two with each treatment) were reported as showing clinical deterioration at any stage during the trial, in all cases after the end of therapy. There were no reports of local or systemic adverse reactions to either drug, and laboratory screening investigations failed to reveal any signs of toxicity. These results indicate that a 4-week course of twice daily topical 2% fenticonazole cream is extremely well tolerated and is at least as efficacious as an equivalent regimen of 2% miconazole for the treatment of cutaneous dermatophytosis or pityriasis versicolor. Trends in the results suggest that fenticonazole may prove to be more efficacious than miconazole, particularly in relation to elimination of laboratory evidence of persistent fungal infection, which could be reflected in a lower incidence of subsequent relapse of the disease.

Adolescent↗
PubMed1986

Glucocorticoid-induced vasoconstriction in human skin. An inhibitory role on phospholipase A2 activity.

The ability of topically applied betamethasone valerate to reduce erythema produced by a variety of vasodilators was assessed. The steroid significantly reduced the erythema induced by topical arachidonic acid, intradermal histamine, and compound 48/80. We postulated that the steroid reduced endogenous phospholipase activity either before or after application of the vasodilators, or both. This action may explain the mechanism of glucocorticoid-induced vasoconstriction in the skin and part of the steroids' action in acute inflammatory skin disease.

Administration, Topical↗