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Biomedical subjects

R Marks

Publications and source records attributed to R Marks.

At least 271 records · Page 15Linked to original sources
PubMed1989

The incidence of non-melanocytic skin cancers in an Australian population: results of a five-year prospective study.

Two thousand, six hundred and sixty-nine persons who were aged 40 years and older attended for examination of the light-exposed areas of the head and neck, forearms and dorsa of the hands during a skin-cancer survey of the population of Maryborough, which was conducted annually for five years from 1982-1986 inclusive. Sixty (2.25%) persons--12 persons each with a squamous-cell carcinoma and 48 persons with a total of 51 basal-cell carcinomas--had at least one non-melanocytic skin cancer at the first examination. One thousand, nine hundred and eighty-one (74% of the study population) persons were seen on more than one occasion, which allowed for 6288 person-years of follow-up for the determination of the incidence of new cancers. The findings showed a calculated minimal age-standardized incidence rate of 873 non-melanocytic skin cancers/100,000 population each year. The minimal incidence rate for basal-cell carcinomas was 672 cases/100,000 population each year and for squamous-cell carcinomas was 201 cases/100,000 population each year. The rate ratio of the incidence of basal-cell carcinomas to that of squamous-cell carcinomas was 3.34 to one. Age, sex, skin reaction to sunlight and occupation all were significant factors in the determination of the risk of developing non-melanocytic skin cancers. The enormous costs that are involved in the treatment of non-melanocytic skin cancers and related lesions suggest that more time, effort and money need to be spent to reduce what has become a major public-health problem in Australia.

Adult↗
PubMed1989

Distribution of pain provoked from lumbar facet joints and related structures during diagnostic spinal infiltration.

This paper describes the patterns of pain induced from lumbar facet joints, from the posterior primary rami of L5, and from the medial articular branches of the posterior primary rami from T11 to L4 in patients undergoing diagnostic spinal infiltrations for chronic pain. No consistent segmental or sclerotomal pattern was found in 385 observations on 138 patients. Pain radiating to the buttock or trochanteric region occurred mostly from the L4 and L5 levels, while groin pain was produced from L2 to L5. The nerves supplying the facet joints gave rise to distal referral of pain significantly more commonly than the joints themselves.

Back Pain↗
PubMed1989

Epidermal dysplasia and cyclosporine therapy in renal transplant patients: a comparison with azathioprine.

The prevalence of dysplastic cutaneous lesions was determined in a group of 68 renal transplant patients whose immunosuppressive therapy included cyclosporine but not azathioprine. The mean age of the patients was 41 years (range 17-67), and the mean transplant time was 44 months (range 24-75). Dysplastic cutaneous lesions were found in 14 out of 68 patients, a prevalence of 20.6%. Although the lesions arose on sun-exposed sites, there was no apparent correlation with previous sun-exposure. The cumulative prevalence of dysplastic cutaneous lesions in 64 patients who had received cyclosporine for between 24 and 72 months was compared with 33 renal transplant patients who had been treated with azathioprine over a similar period of time. The overall prevalence of cutaneous dysplasia was 22% in the cyclosporine group and 9% in the azathioprine group. The cumulative prevalence of cutaneous dysplasia in the cyclosporine group was greater at all time points studied. In contrast to previous reports, we have found no evidence that the risk of cutaneous malignancy in patients treated with cyclosporine is less than that found in patients maintained on azathioprine.

Adolescent↗
PubMed1989

Two novel techniques for the evaluation of barrier creams.

There are few methods for assessment of the efficacy of barrier cream preparations that can be used in vivo. This paper describes two such tests. The first relies on the ability of a topically applied barrier preparation to prevent dyes from reaching the stratum corneum from filter paper discs in small aluminium chambers. The amount of dye crossing the barrier cream and reaching the stratum corneum was assessed by removing the superficial layers by skin surface biopsy and eluting out the dye. The second test employed dilutions of sodium hydroxide as indicator reagents. The degree to which these solutions penetrated the barrier on the skin was assessed by measuring the skin blood-flow using the laser Doppler method. It was concluded that both methods could be usefully employed to assess the degree of efficacy of barrier cream preparations.

Adult↗
PubMed1989

The use of A-scan ultrasound in the assessment of small skin tumours.

This study describes the use of A-scan ultrasound for the measurement and characterization of tumour tissue in small skin tumours--basal cell carcinoma, melanocytic naevus, hypertrophic scars and intraepidermal epithelioma. Assessment of the A-scan traces by measurement of: (i) the amplitude of echoes within the area of interest; (ii) the density (number per unit depth) of these echoes; (iii) the regularity of spacing and amplitude of the echoes, and (iv) the amplitude of echoes beneath the area of interest, was used to assist in the differential diagnosis. The results show significant differences in echo amplitude between all the tumours and normal skin. When the tumour A-scan traces were analysed the results indicated that the best discriminating feature between tumours was that of amplitude, followed by regularity, density, non-normalized thickness and finally amplitude of echoes from beneath the tumour. Ultrasound-derived skin thickness measurements were compared to histological measurements for the lesions, and an excellent correlation was found (r = 0.96). It was considered that the A-scan ultrasound investigation of small tumours of the skin was able to provide information on the nature of the tissues contained and may assist in their differential diagnosis.

Adult↗
PubMed1989

The significance of the Darier-like solar keratosis and acantholytic change in preneoplastic lesions of the epidermis.

Fifty-two lesions of solar keratosis from 40 patients were studied prospectively for the presence of Darier-like changes and acantholysis. Twenty-seven per cent of specimens showed some degree of these changes. The affected lesions tended to be larger and were less common on the hands, but were otherwise clinically indistinguishable from other solar keratoses. Histologically, the specimens with Darier-like changes were significantly thicker and more dysplastic. The autoradiographic labelling index was not different for the lesions with these changes indicating similar cell kinetic characteristics. It is suggested that acantholytic separation of epidermal cells within a solar keratosis may signify that the lesion has a greater invasive potential than a solar keratosis not showing this change.

Acantholysis↗
PubMed1989

Changes in endothelial cell mass, luminal volume and capillary number in the gravitational syndrome.

The histopathological changes in the skin of 31 patients with the gravitational syndrome and 10 normal control subjects were studied. To quantify the clinical severity of the syndrome, a new index of severity was used. Histometric evaluation of the cutaneous vasculature was performed on biopsies taken from the edge of the ulcers in the 31 patients and from the medical aspect of the lower legs in control subjects. Endothelial cell mass did not correlate with the clinical index of disease severity, suggesting that angiogenesis did not necessarily signal healing. The mean luminal volume appeared to be of greater prognostic value as there was a significant negative correlation of this parameter with the index of clinical severity. The degree of epidermal hyperplasia was found to be related to both the amount of inflammatory cell infiltrate present and the endothelial cell mass per unit tissue volume. The results also showed that the clinical index of disease severity was positively correlated to the mean epidermal thickness. The quantitative evaluation of biopsy material can be used to provide prognostic information in the gravitational syndrome.

Adult↗
PubMed1989

Assessment of disease progress in psoriasis.

Effective methods of recording and measuring progress of the signs of psoriasis are essential and central to the accurate assessment of therapy. Currently there is wide variation in assessment methods used, and even well-designed clinical assessment techniques have a wide observer error: objective assessment methods may have advantages. The clinical assessment techniques used in 30 clinical trials of treatment in chronic plaque psoriasis in 1985 and 1986 were reviewed and a detailed analysis is presented. In only 18 trials were individual regions assessed, and widely differing methods of scoring signs were used. Reproducibility of the assessment by clinicians of area of skin involvement by psoriasis was studied. Ten patients with chronic plaque psoriasis had standardized photography, and four clinicians assessed area of involvement from the photographs. The clinicians significantly differed in their rank ordering of the area of psoriatic skin involvement. Area of involvement by psoriasis in the same photographs was assessed objectively using computer-assisted planimetry. Although the clinicians' assessment did not differ randomly from the objective measurement, the accuracy of subjective area assessment is not the same for all clinicians. As even experienced clinical observers show wide variation when attempting to record clinical severity of psoriasis, there is clearly a need for better objective measures of psoriasis severity.

Adolescent↗
PubMed1988

Malignant transformation of solar keratoses to squamous cell carcinoma.

1689 people aged 40 years and over were examined over a 5-year period to determine the incidence of malignant transformation of solar keratoses. They were seen on 2 consecutive years on 4267 occasions; a total of 21,905 solar keratoses were present on the first visit. A squamous cell carcinoma (SCC) developed within 12 months on 28 of the 4267 occasions. Where accurate mapping of both SCCs and pre-existing solar keratoses was available, it was found that 10/17 (60%) SCCs arose from a lesion diagnosed clinically as a solar keratosis in the previous year and the other 7 (40%) SCCs on what had been clinically normal skin 12 months previously. The risk of malignant transformation of a solar keratosis to SCC within 1 year was less than 1/1000. The cost-effectiveness of treating all solar keratoses to prevent the development of SCC is questionable.

Aged↗
PubMed1988

Incidence of non-melanocytic skin cancer treated in Australia.

In 1985, as part of a national random household omnibus survey by a market research company, 30,976 Australians (mostly of European origin) were asked whether they had ever been treated by a doctor for skin cancer. The treating doctor or hospital was then approached for confirmation of the diagnosis of all those people who claimed to have been so treated within the past 12 months. Demographic data were also collected, permitting analysis by age, sex, country of birth, current residence, and skin reaction to strong sunlight. Melanomas accounted for less than 5% of the tumours treated. The world standardised incidence of melanoma was 19/100,000 population. The standardised incidence of treated non-melanocytic skin cancer in Australia was estimated to be 823/100,000. The standardised rates for basal cell carcinoma and squamous cell carcinoma were 657 and 166/100,000 respectively, yielding a standardised rate ratio of about 4:1. Standardised rates based on medically confirmed cases only were 555, 443, and 112/100,000 for all non-melanocytic skin cancers, basal cell carcinomas, and squamous cell carcinomas respectively. Significant differences and trends in incidence were noted with respect to age and sex. Rates in men were higher than those in women but significantly so only after the age of 60. People born in Australia had a rate of 936/100,000 compared with 402/100,000 in British migrants. Rates for non-melanocytic skin cancer showed a gradient with respect to latitude within Australia. The rate in people residing north of 29 degrees S was 1242/100,000 compared with a rate of 489/100,000 in those living south of 37 degrees S. A person's skin reaction to strong sunlight was a good indicator of the risk of skin cancer, tanning ability being inversely related to its incidence. The rate in those who always burnt and never tanned when exposed to strong sunlight was 1764/100,000 compared with a rate of 616/100,000 in those who always tanned and never burnt. These findings have important implications for public education programmes in relation to exposure to sunlight in Australia.

Adolescent↗
PubMed1988

Growth and antigenic characteristics of basal cell carcinoma in culture.

Basal cell carcinomas (BCCs) were cultured using an explant method and compared with normal cultured skin. Immunohistochemical staining revealed reduced beta 2 microglobulin uptake by BCCs in frozen section, but normal staining of the tumours in culture. In culture, fibronectin was detected on the cell surface of normal keratinocytes but not on BCCs. The above differences may explain some of the behaviour of BCCs in vivo.

Antigens, Neoplasm↗
PubMed1988

Clinical response and tissue effects of etretinate treatment of patients with solar keratoses and basal cell carcinoma.

Patients with basal cell carcinoma and solar keratoses were treated with etretinate. Substantial and prolonged clinical improvement was seen. All patients with solar keratoses showed a decrease in the mean area and number of lesions and eight patients demonstrated complete healing clinically. Two patients experienced recurrence at 9 months after completion of treatment. Histometric and cell kinetic measurements on the epidermis of skin samples from these patients were performed. They revealed epidermal thickening and increased deoxyribonucleic acid (DNA) synthesis both in lesions and in clinically uninvolved skin following treatment. Assessments were also made of enzyme activities in lesions and uninvolved skin with the use of established quantitative cytochemical techniques. Significant reduction in levels of succinic dehydrogenase activity following etretinate treatment was detected in solar keratoses and in basal cell carcinomas. This was also the case for uninvolved skin of patients with solar keratoses. Glucose-6-phosphate dehydrogenase (G6PD) activity was significantly reduced following etretinate treatment in solar keratoses and in basal cell carcinomas, but uninvolved skin did not exhibit significant changes. These changes are in contrast to those previously reported in normal subjects, where the activity increased, but are similar to those observed in patients with ichthyotic disorders. The alterations in the cytochemical profile following administration of etretinate in the lesions of patients reported here are consistent with the view that the drug promotes a more normal pattern of epidermal differentiation. We favor the view that etretinate's antineoplastic action is exerted by preferentially allowing differentiation of normal epidermal cells and inhibiting dysplastic cells.

Aged↗
PubMed1988

Skin cancer in a Queensland population.

In the present study we have estimated the current prevalence of actinic skin disease in young and middle-aged adults in Queensland, Australia by surveying a representative community. It was found that 4.6% of persons aged 20 to 69 years had skin cancer, mostly basal cell carcinoma, and 40% had solar keratoses. The age distribution and site distribution of actinic lesions in this population were not as classically described; persons below age 40 years exhibited substantial sun-related skin damage, and a large proportion of actinic lesions occurred on sites other than the head, backs, of hands, or forearms. Allowing for age and sex, the strongest risk factors for skin cancer and solar keratoses were fair skin, as assessed by a dermatologist, and clinical signs of solar damage such as solar lentigines, facial telangiectasia, and actinic elastosis of the neck. Associations with self-reported tendencies toward sunburn, frequent painful sunburns, occupational sun exposure, and a previous history of skin cancer were confirmed.

Adult↗
PubMed1988

Measurement of subcutaneous fat thickness with high frequency pulsed ultrasound: comparisons with a caliper and a radiographic technique.

This paper reports the use of a 10 MHz pulsed A-scan ultrasound system to measure the thickness of subcutaneous fat and its comparison with two other established techniques. Measurements using both ultrasound and Harpenden's skin calipers were made on the abdomen, over the scapula region, over the triceps and on the front of the thigh. Computerised axial tomography (CAT) was also used to obtain measurements of subcutaneous fat over the abdomen. In most instances the different techniques were significantly correlated. The ultrasound method showed non-dependency or bias upon the size of measurement when compared with the other two techniques. In addition, the ultrasound method was considered more accurate, reproducible and sensitive compared with the caliper technique and much more convenient than CAT scanning. However, the presence of septa at some sites in the more obese subjects was revealed by CAT scanning and made ultrasound assessment at these sites more difficult.

Adipose Tissue↗