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Biomedical subjects

R M Herd

Publications and source records attributed to R M Herd.

At least 19 recordsLinked to original sources

A clinical and histologic prospective controlled comparative study of the picosecond titanium:sapphire (795 nm) laser versus the Q-switched alexandrite (752 nm) laser for removing tattoo pigment.

BACKGROUND: Theory predicts that picosecond lasers should be more effective than the currently available nanosecond lasers in removing tattoo ink. In addition to thermal confinement, such pulse widths cause optimal photomechanical disruption of the target. OBJECTIVE: This study compared the efficacy of the picosecond titanium:sapphire (795 nm, 500 psec) laser and the Q-switched alexandrite (752 nm, 50 nsec) laser in the treatment of tattooed guinea pigs. METHODS: Six albino guinea pigs, each with 6 uniformly 1 cm circular black tattoos, were treated. Three of the tattoos were divided into 2; one half was treated with the titanium:sapphire laser and the other half with the alexandrite laser. Fluences used for both lasers were 6.11, 4.24, and 2.39 J/cm2 with spot sizes of 1.25, 1.5, and 2 mm, respectively. The remaining spots served as control. Clinical evaluation and biopsies were performed at baseline and at 11 and 16 weeks after a single laser treatment. RESULTS: Greater clearance of tattoo was observed in titanium:sapphire laser-treated areas in 2 of the 4 surviving guinea pigs. In some areas total clearing was observed after the single titanium:sapphire laser treatment. Clearing improved with higher fluences. No scarring was present. Histologic results showed similar findings. CONCLUSION: Our findings suggest that the picosecond titanium:sapphire laser is more effective than the Q-switched alexandrite laser in removing tattoo pigment and may be of significant clinical utility.

Animals

A rational approach to melanoma follow-up in patients with primary cutaneous melanoma. Scottish Melanoma Group.

From the Scottish Melanoma Group database for south-east Scotland we evaluated 5-year follow-up in patients with cutaneous malignant melanoma excised between 1979 and 1994 and devised an 'evidence-based' review protocol. Of the 1568 with stage I melanoma, 293 (19%) developed a recurrence, 32 had a second primary melanoma and 97 had an in-situ melanoma. The disease-free interval shortened progressively with increasing tumour thickness. Overall, 80% of recurrences were within the first 3 years, but a few patients (< 8%) had recurrences 5 or 10 years after the initial surgery. In-situ melanomas did not recur. Almost half (47%) the recurrences were noted first by the patient, and only 26% were detected first at a follow-up clinic. One hundred and thirty-nine patients (89%) were still under review when their recurrences were detected, and 102 (65%) had been seen within the previous 3 months. Questionnaires were completed by 120 patients: sun protection and avoidance, and mole examination were more likely after melanoma excision. We recommend 3-monthly review of patients with invasive lesions for the first 3 years. Thereafter, those with lesions >/= 1.0 mm need two further annual reviews. Patients with in-situ lesions should be reviewed once, to confirm adequate excision (0.5 cm margins) and to give appropriate education. Surveillance beyond 5 years is only justified if there are special risk factors.

Clinical Protocols

Familial halo naevi.

The incidence of halo naevi in the population has been estimated to be 1%. We now report the simultaneous occurrence of such naevi in four members of a family previously resident in New Zealand.

Adolescent

Keratosis follicularis spinulosa decalvans: confirmation of linkage to Xp22.13-p22.2.

Keratosis follicularis spinulosa decalvans (KFSD) is a rare, X linked disorder with skin and eye involvement (MIM 308800). We have studied a large British family with KFSD using polymorphic markers from Xp21-p23 and obtained a lod score of 2.056 at theta=0 with markers proximal and distal to the KFSD candidate region Xp22.13-p22.2 identified by Oosterwijk et al. Our data confirm the linkage to Xp22.13-p22.2 observed in the previously reported Dutch family, but fail to narrow the candidate interval for the KFSD locus.

Darier Disease

Basic laser principles.

Skin diseases have been treated with lasers since the early 1960s. The three principal chromophores in the skin--hemoglobin, melanin, and water--have different absorption spectra that selectively absorb certain wavelengths of electromagnetic radiation. A given wavelength and pulse duration will selectively treat a target containing a chromophore. The wide variety of lasers and their applications are discussed.

Dermatologic Surgical Procedures

Optimum postweaning test for measurement of growth rate, feed intake, and feed efficiency in British breed cattle.

The optimum duration of test for measurement of growth rate, feed intake, feed conversion, and residual feed intake was examined using postweaning feed intake and weight data from 760 Angus, Hereford, Polled Hereford, and Shorthorn heifer and Angus bull progeny from 78 sires. Variance components, heritability, phenotypic and genetic correlations, and the efficiency of selection using shortened tests compared with a 199-d test were used as criteria to assess the optimum test length. The results indicated that a 35-d test was sufficient for measurement of feed intake, whereas a 70-d test was required to measure growth rate, feed conversion, and residual feed intake without compromising the accuracy of measurement. When a 70-d test is used to measure growth rate, feed conversion, and residual feed intake there is minimal loss in accuracy when weights are collected every 2 wk instead of weekly, but a further increase in the interval between weights to 5 wk caused a decline in the accuracy of the test. Therefore a 70-d test with cattle weighed every 2 wk seems to be optimal for measuring these traits in British breed cattle.

Animal Feed

Measurement of quality of life in atopic dermatitis: correlation and validation of two different methods.

Atopic dermatitis is a chronic relapsing condition that can have considerable effects on the lives of sufferers. It is apparent that good, valid measures of life quality are necessary for quantifying the patients' perspective of the severity of their disease and the Dermatology Life Quality Index is often employed in clinical research. In a community study of atopic dermatitis we have assessed disability using the Dermatology Life Quality Index and the Patient Generated Index and compared the results from both indices. The results were significantly correlated and reflected the range of disability in patients in the community. Some items of the Dermatology Life Quality Index were not relevant for atopic dermatitis patients in the community and others, including swimming and sleep loss, were often cited in the Patient Generated Index but are not included in the Dermatology Life Quality Index. The Patient Generated Index is a novel, flexible approach to quality of life measurement that may be suitable for reflecting the wide variety of disability that is experienced by dermatological patients.

Activities of Daily Living

Keratosis follicularis spinulosa decalvans: report of a new pedigree.

Keratosis follicularis spinulosa decalvans is a rare, X-linked genodermatosis characterized by follicular hyperkeratosis, scarring alopecia of the scalp, eyebrows and eyelashes, corneal dystrophy and photophobia. We describe two cases from a large family, the first with keratosis follicularis spinulosa decalvans to be reported in the U.K.

Adult

Prevalence of atopic eczema in the community: the Lothian Atopic Dermatitis study.

An epidemiological study of atopic eczema (AE), based on a semirural community in Scotland, using sound diagnostic criteria, has yielded prevalence data for all age groups including infants and adults. The overall 1-year period prevalence, age-standardized to the Scottish population, was 2.3%. The 1-year period prevalence was highest in the under 2s (9.8%), and showed a continuous reduction with increasing age. Over the age of 40, AE was found to be relatively rare, with a 1-year period prevalence of 0.2%. Adults over 16 years made up 38% of all patients with AE.

Adolescent

The cost of atopic eczema.

Atopic eczema affects 2.3% of the U.K. population. We have carried out a community study in a semi-rural area to assess its economic impact. One hundred and fifty-five patients with atopic eczema were identified and expenditure was assessed over a 2-month period. The mean personal cost to the patient was pounds 25.90, while the mean cost to the health service was pounds 16.20. There were 58 lost working days and 17 lost school days. A cohort of 10 severely affected patients attending the Royal Infirmary of Edinburgh were studied; each patient spent, on average, pounds 325 in 2 months, and lead to a mean health service expenditure per patient of pounds 415, in 2 months. If these results were extrapolated to the U.K. population, the annual personal cost to patients with atopic eczema would be pounds 297m, the cost to the health service would be pounds 125m, and the annual cost to society of lost working days would be pounds 43m, making the total expenditure on atopic eczema pounds 465m.

Adolescent

Neonatal cerebral arterial flow velocity waveforms in term infants with and without metabolic acidosis at delivery.

To define the effects of acid base status at delivery on neonatal cerebral artery flow velocity waveform patterns obtained using Doppler ultrasound during the first week of life, a longitudinal comparative study of neonates born at term with and without evidence of metabolic acidosis in the umbilical artery was undertaken. Eighty-two appropriate for gestational age infants delivered after uncomplicated pregnancies with non-acidotic umbilical artery blood gases and in whom no neonatal complications were noted were studied to establish reference values of neonatal cerebral arterial vascular resistance index (RI) in normal term infants during the first week of life. A further 189 infants were grouped according to the presence and severity of metabolic acidosis at delivery, and also the presence of high risk features in the antenatal period. In the normal non-acidotic infants, over the first 24 h of life, there was a significant fall in the cerebral arterial resistance index (RI) in all the vessels examined, after which a steady state value was attained with no significant changes in vascular resistance index being noted during the remainder of the study period. The fall in RI between 12 and 24 h of age was consistent in all study groups. Infants with metabolic acidosis at delivery had blood flow patterns compatible with decreased resistance to flow in both anterior and middle cerebral arteries which persisted throughout the first week of life. This reduction in cerebral vascular resistance was most marked in those infants with severe metabolic acidosis. The majority of severely acidotic infants had a benign clinical outcome in the first week of life and all infants had normal cerebral ultrasound scans during the neonatal period. These findings suggest that metabolic acidosis at birth is associated with changes in neonatal cerebral arterial vascular resistance during the first week of life, and in the presence of benign clinical course the significance of this observation with regard to neurodevelopmental outcome requires evaluation.

Acidosis

Cutaneous malignant melanoma. Publicity, screening clinics and survival--the Edinburgh experience 1982-90.

The incidence of cutaneous malignant melanoma has increased considerably in south-east Scotland over recent years. In 1987 the Cancer Research Campaign launched a project to aid the early detection, diagnosis and treatment of malignant melanoma. Edinburgh, chosen as one of seven centres in the U.K. to participate in the study, was provided with funding for a direct access pigmented lesion clinic from 1987 to 1989. The changes in the pattern of cutaneous malignant melanoma before, during and after the publicity campaign have been examined; between 1982 and 1990. The incidence of malignant melanoma doubled from 5.7 to 11.4/100,000 per annum. The percentage of thin tumours (Breslow thickness < or = 1.5 mm) increased steadily and significantly (from 43% in 1982 to 68% in 1990), but the number of thick tumours (Breslow thickness > 3.0 mm) remained constant over the same period (22 +/- 3.8). The influence of publicity was assessed using a questionnaire. Those who were influenced by publicity were significantly younger and had more thin tumours (Breslow < or = 1.5 mm) than those who were uninfluenced by publicity. Five-year survival has significantly increased from 70% in the 1982-84 cohort to 84% in the 1987-89 cohort. The effect of the publicity campaign has been beneficial, but the impact on mortality cannot yet be assessed.

Female

Agminate Spitz naevi arising on hyperpigmented patches.

In 1948 Dr Sophie Spitz described criteria that distinguished juvenile melanoma from malignant melanoma. Since then the cases of eruptive Spitz naevi have been reported arising on normal skin, on lightly pigmented patches and on hypopigmented patches. There are only 12 reports of Spitz naevi arising on hyperpigmented patches: we describe here three further cases, all on the arms of children, seen in our department in a single year.

Child

Cardiac effects of sodium stibogluconate: myocardial, electrophysiological and biochemical studies.

The pentavalent antimonial sodium stibogluconate is the mainstay of anti-leishmanial therapy. Sodium stibogluconate is less cardiotoxic than antimony and the trivalent derivatives, but has been associated with dose-related electrocardiographic changes. The effect of the currently-used regimen of sodium stibogluconate (20 mg/kg/day for 20 days) on cardiac function is uncertain. We studied 12 soldiers, mean age 24 years, with proven cutaneous leishmaniasis treated with this regimen. There were no significant changes in echocardiographic indices of left ventricular systolic or diastolic function during treatment. Indices of myocardial electrical stability (heart-rate variability and episodes of overt supraventricular and ventricular arrhythmias) were unchanged, but there was a reversible decrease in T-wave amplitude during treatment. Systolic and diastolic blood pressure fell and the heart rate increased during treatment. This regimen of sodium stibogluconate does not measurably impair left ventricular systolic or diastolic function. Minor T-wave changes occur during treatment, but there is no increase in arrhythmia frequency or change in heart-rate variability. In most young fit patients, this regimen has no cardiac side-effects. However, idiosyncratic reactions cannot be excluded, and patients with malnutrition, impaired renal function or pre-existing heart disease may be more sensitive to any cardiotoxic properties of sodium stibogluconate.

Adult

Linear lichen planus and lichen striatus--opposite ends of a spectrum.

The linear pattern of lichen planus (LP) is extremely rare. In six publications 1256 patients with LP have been reviewed and only three cases of linear LP (LLP) are reported. The differential diagnosis of LLP includes a number of linear dermatoses in particular lichen striatus (LS) and the extent of overlap between these syndromes remains contentious.

Adult

Excision biopsy of malignant melanoma by general practitioners in south east Scotland 1982-91.

OBJECTIVE: To examine the management of patients who had a malignant melanoma excised initially by general practitioners in south east Scotland over the past 10 years and to assess the impact of the April 1990 contract on this. DESIGN: A retrospective case-control study. SETTING: South east Scotland. SUBJECTS: All patients in south east Scotland who had malignant melanomas excised by general practitioners in 1982-91. OUTCOME MEASURES: Demographic details of patients; Breslow thickness, clearance of excision. RESULTS: 42 patients had malignant melanomas excised by general practitioners in 1982-91: 15 in 1982-9 and 27 in 1990-1. These patients were significantly younger than those who had their tumours excised initially in hospital. Although the longest diameter of melanomas excised by general practitioners was significantly less than of those excised in hospital, the Breslow thicknesses were similar. Completeness of initial excision was doubtful or incomplete in nine (23%) general practitioner excisions compared with 4% of hospital excisions, but the time interval between excision biopsy and wide excision was similar. Pathology requests accompanying excision biopsies mentioned melanoma as a possible diagnosis in 15% (6/40) of general practitioner cases compared with 79% of hospital cases. Thirty nine general practitioners responded to a questionnaire and only 12 had considered melanoma in the differential diagnosis. CONCLUSIONS: General practitioners need to think more often of malignant melanoma when they excise pigmented lesions and when they consider this tumour a possibility should perform an excision biopsy with a lateral clearance of at least 2 mm.

Adult