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Biomedical subjects

R Marks

Publications and source records attributed to R Marks.

At least 199 records · Page 11Linked to original sources
PubMed1993

Trends in non-melanocytic skin cancer treated in Australia: the second national survey.

An Australia-wide survey in 1985 recorded the highest rates of medically treated non-melanocytic skin cancer (NMSC) ever reported. We report the findings of a repeat survey conducted in 1990. This second survey confirmed the differences, by age, sex, body site, latitude, country of birth and skin reaction to strong sunlight, that were observed in 1985. Over the 5-year period certain changes were noted: the incidence of NMSCs increased by 19%, of basal-cell carcinomas (BCC) by 11% and of squamous-cell carcinomas (SCC) by 51%. With advancing age, men and women differed in their incidence, and this difference was greater for SCC than for BCC. Log-linear modelling, however, failed to detect either a cohort or a survey effect between the 2 surveys. The proportional distribution of BCCs and SCCs by body site indicated an increase in BCCs on the trunk in both men and women, and half the proportion of SCCs on the head and neck in women as compared with men. The latitudinal gradients observed in 1985 were even stronger in 1990; the population living north of 37 degrees S experienced a 30% increase in the incidence of treated NMSC between 1985 and 1990, while the population living south of 37 degrees S had a 25% decrease. The implications of these findings for cancer-control initiatives are discussed.

Adult↗
PubMed1993

The effect of isometric quadriceps strength training in mid-range for osteoarthritis of the knee.

This case report describes the effect of strengthening the quadriceps of an effused osteoarthritic knee joint of a 53-year-old man isometrically in mid-range. The instruments included an isokinetic dynamometer, a knee scoring inventory, and a visual analog scale. The outcome measures of isometric quadriceps torque and work, clinical status, and pain were recorded before and after the exercise intervention. The exercises were carried out three times per week for a 6-week period with the subject seated on an exercise chair. Following training, quadriceps torque increased, clinical status improved, and pain with walking decreased. Subject to further investigation, isometric training of the quadriceps in mid-range could prove useful for improving the function of persons with painful or effused knees who might otherwise experience muscle inhibition by exercising in the more traditional inner ranges of knee extension.

Exercise Therapy↗
PubMed1993

Proprioceptive sensibility in women with normal and osteoarthritic knee joints.

The objective of this study was to quantify the effect of degenerative joint change on the proprioceptive acuity of women with osteoarthritis (OA) of the knee. Middle-aged women with OA of the knee, age-matched healthy women, and younger healthy women were studied. Tests examined the ability of subjects to correctly reproduce knee angles in weightbearing and non-weightbearing situations. The knee angles were photographed and measured in degrees. The absolute error (AE) of each matching test was calculated and the mean AE of two tests was used as the criterion variable in a three-way analysis of variance (ANOVA). The relationship between the reproduction error and the osteoarthritic subjects' self-paced walking speed was also examined. Under both test conditions the AE of the osteoarthritic subjects was greater than that of the healthy subjects (p < .05). There was, however, no significant relationship between the AE measurements of the patients and their walking speed. These data indicate that while women with OA may have poorer proprioception than healthy controls, this impairment may not affect their walking ability.

Adult↗
PubMed1993

The acute effects of ultraviolet-B radiation on c-myc and c-Ha ras expression in normal human epidermis.

It is well known that ultraviolet radiation (UVR) causes DNA damage due to the formation of photoproducts which result in the inhibition of DNA synthesis. It has been reported that DNA damage by physical agents such as UVR and chemical carcinogens induces alteration of certain gene expressions. Recently the transient induction of c-myc and c-Ha ras proto-oncogene expressions has been observed in a human keratinocyte cell line in vitro. The present study was designed to investigate whether the induction of these proto-oncogenes occurs in normal human epidermis after UVR in vivo and to relate these findings to DNA synthesis. C-myc and c-Ha ras transcripts were detected throughout human epidermis before and after UVR. C-myc expression increased significantly 5 h after two times the minimal erythema dose (2 x MED) of UVR, while DNA synthesis of the irradiated skin had recovered from the UVR-induced inhibition. The intensity of c-Ha ras expression remained unchanged at both 5 and 24 h after UVR. These results suggest that the c-myc gene plays an important role in the recovery of keratinocytes from acute damage following UVR.

Adult↗
PubMed1993

Changes in sun-related attitudes and behaviours, and reduced sunburn prevalence in a population at high risk of melanoma.

This study aimed to determine trends in exposure to sunlight in the context of a melanoma prevention programme by monitoring the prevalence of sunburn and sun-related attitudes and behaviours. Telephone interviews were conducted in a baseline summer (December 1987 to February 1988) and two subsequent summers after the introduction of the SunSmart health promotion campaign. Interviewing a sample of 4,428 adult residents of the Australian city of Melbourne took place throughout summer on Monday evenings. Behavioural and sunburn data were reported for the previous weekend and relevant attitudinal data were collected. After adjusting for ambient ultraviolet radiation levels and temperature, survey month, age, sex and skin type, a significant reduction in sunburn was found. The crude proportion of sunburnt dropped from 11% to 10% to 7% over 3 years and the adjusted odds ratios (and 95% confidence intervals) were as follows: Year 1/Year 2; 0.75 (CI 0.57-0.99) and Year 1/Year 3; 0.59 (CI 0.43-0.81). Substantial attitudinal shifts occurred over the 3 years. Hat wearing increased significantly each year (19%, 26%, 29%), as did sunscreen use (12%, 18%, 21%). However, the trends in mean proportion of body surface area covered by clothing were less clear cut (0.67, 0.64, 0.71). It is concluded that melanoma risk factor exposure of populations can change fairly rapidly and that well-conducted health promotion campaigns can play a part in producing such change.

Adolescent↗
PubMed1993

Acral epidermolytic hyperkeratosis.

We present a family with a distinctive pattern of epidermolytic hyperkeratosis which is mild, restricted to the distal parts of the limbs, and non-disabling. Features of the other variants of epidermolytic hyperkeratosis are discussed.

Child↗
PubMed1993

The frequency of reactions to sunscreens: results of a longitudinal population-based study on the regular use of sunscreens in Australia.

Six-hundred-and-three people aged 40 or more years, from Maryborough in central Victoria, were enrolled in a randomized longitudinal study, which required daily application of either a SPF 15+, broad-spectrum, water-resistant sunscreen cream or the cream base without the active ingredients. The study duration was 7 months, from September 1991 until April 1992. One-hundred-and-fourteen (18.9%) of these subjects developed an adverse reaction to the cream they were applying. Patch testing, photopatch testing and scratch testing with the ingredients of the creams revealed that only a small proportion (< 10%) of the inflammatory eruptions were allergic in nature. None of the people tested was allergic to the sunscreen active ingredients. History and examination findings, where available, suggested that the majority of adverse responses were consistent with an irritant reaction, both to the sunscreen preparation and the base cream control. A higher than expected proportion of the people who developed an adverse reaction had a personal history consistent with atopy. Other reactions included acneiform eruptions and contact urticaria. A frequency of reactions to sunscreen preparations of over 15% means that further work is necessary to improve both the formulation of such products, and the manner and conditions under which they are used, to ensure satisfactory compliance.

Adult↗
PubMed1993

A model of measured percussive mechanical trauma and its effects on skin.

In this study, the role of mechanical trauma to skin in industrial dermatitis is considered. The percussive component of mechanical trauma to skin is investigated by modelling it, using an oscillating device which can supply a range of percussive trauma doses. The instrument is electronically controlled, and contains sensors which monitor the force and displacement throughout each impact. From this information, a value proportional to the dose delivered to the skin is calculated and used, rather than the driving power of the percussor. The rate of dose is also controlled. In this study, doses were delivered at a frequency of 7 Hz. Eight volunteers were given regimens of percussive trauma at regular intervals over a 5-day period. Half the group received a dose of 4 mJ/cm2 per impact, the other half received double this dose. The skin response was evaluated using non-invasive measurements of transepidermal water loss, skin thickness, and erythema. The results demonstrate that erythema, skin thickness and transepidermal water loss are all increased after mechanical challenge--erythema and water loss by amounts dependent upon the trauma dose applied. The transepidermal water loss results indicate that for the subjects used in our study, there was a trauma threshold reached after a cumulative dose of greater than 250 J/cm2.

Dermatitis, Occupational↗
PubMed1993

Cyclosporin greatly improves the quality of life of adults with severe atopic dermatitis. A randomized, double-blind, placebo-controlled trial.

A multicentre, randomized, double-blind, controlled crossover clinical trial was conducted on 33 patients with severe refractory atopic dermatitis, to determine the effects of cyclosporin (5 mg/kg/day) on their health-related quality of life. Treatments were administered for 8-week periods. One group (n = 16) received placebo followed by cyclosporin, and the other (n = 17) received cyclosporin and then placebo. Health-related quality of life was assessed at 0, 8 and 16 weeks using a general measure, the United Kingdom Sickness Impact Profile (UKSIP), an eczema-specific measure, the Eczema Disability Index (EDI), and a global 5-point rating scale of overall health (very good to very poor). In addition, clinical assessments (i.e. extent and activity of disease) were made by the investigators. UKSIP and EDI scores indicated significant improvement in quality of life (P < 0.05-P < 0.01) of patients with atopic dermatitis after treatment with cyclosporin. Although no patient required withdrawal from the study, 20 patients receiving cyclosporin reported adverse events, compared with eight taking placebo. There was a close correlation (P < 0.05-P < 0.01) between the UKSIP and EDI scores. In contrast, there was either no correlation, or only a very poor correlation, between the quality of life parameters and clinical measures of extent and activity of eczema. When cyclosporin was stopped, relapse was rapid, but the mean scores for disease activity and extent of disease were less than their baseline values (i.e. an improvement of greater than 25% was maintained in 11 patients at week 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1993

Collodion baby dehydration: the danger of high transepidermal water loss.

We describe transepidermal water loss (TEWL) measurements in a collodion baby suffering from severe hypernatraemic dehydration and hypothermia, who required intravenous fluid therapy in a special incubator. The TEWL values 4 days after birth were abnormally high compared with normal infants of the same age. The TEWL measurements returned towards normal within the first month, in parallel with the improvement of both the skin signs and the electrolyte and fluid balance.

Dehydration↗
PubMed1993

Medical maintenance: a pilot study.

In a one year study, 130 methadone maintained subjects with a six month history of good treatment performance were assigned randomly to an experimental condition of one monthly non-random urine screen, one monthly counseling session, one monthly doctor visit, two times per month methadone pick up, a quarterly true random urine screen and participation in a diversion control program or to a control condition of staying under standard conditions for six months and then being transferred to the experimental condition for six months. Results of urine screens and scores on the Addiction Severity Index (ASI) at entrance and six month intervals showed no differences between groups. Three out of four subjects completed the year in good standing. Subject satisfaction was such that the IRB judged that return to standard conditions would be a hardship. Experimental conditions were cheaper such that resources freed up could be applied to the HIV epidemic.

Adult↗
PubMed1993

Adverse reactions to oral retinoids. An update.

Retinoids, both naturally occurring and synthetic, are analogues of vitamin A. They represent a major advance in the treatment of acne and psoriasis, as well as rarer conditions such as the ichthyoses. The more frequent and widespread use of these drugs requires that the dermatologist be aware of the wide spectrum of adverse events that may be encountered with their use. Some are serious and irreversible, such as teratogenicity, necessitating great care if these drugs are given to women of childbearing potential. Other effects may be less severe, dose dependent and reversible. Although not devastating to the patient, appropriate advice may reduce morbidity.

Administration, Oral↗
PubMed1993

Effect of fatiguing maximal isokinetic quadriceps contractions on ability to estimate knee-position.

This randomized controlled study compared the accuracy of knee positioning by 8 women after fatiguing maximal isokinetic contractions of the quadriceps with those of 8 controls who performed no exercise. The mean algebraic error (AE) and variable error (VE) showed a significant posttest improvement for the control group after a 5-min, intertrial period. There was no change in accuracy of knee positioning postexercise, however, for the experimental group. These findings suggest that, while a single bout of fatiguing knee exercises may not alter absolute accuracy of knee positioning, the movements may undermine the relative proficiency attainable by learning. They suggest a role for central as well as peripheral mechanisms in mediating this sensory modality.

Adolescent↗
PubMed1993

Reliability and validity of the measurement of position sense in women with osteoarthritis of the knee.

OBJECTIVE: We examined the test-retest reliability and the construct validity of the measurement of knee position sense for describing the functional weightbearing performance of women with osteoarthritis (OA) of the knee. METHODS: For the purpose of this study, position sense was defined as the error occurring when subjects attempted to reproduce a criterion angle in standing with visual cues eliminated. Five such tests were recorded photographically on 3 different occasions. On each occasion the 10 subjects also completed a self-paced walking test over a 13 m indoor walkway. RESULTS: The photographic measurements were reproducible (r = 0.90) and there was no change in positioning accuracy across sessions. There was a significant (p < 0.05) inverse correlation of 0.70 between the standard deviation of the mean individual measurements of position sense (precision of the test) and those of walking speed. CONCLUSION: Our study demonstrates good measurement reliability and a comparable mean angular error with repeated tests. It also suggests the amplitude of the variability of this error is a strong determinant of an individual OA patient's functional performance in walking.

Aged↗