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Biomedical subjects

R P Dawber

Publications and source records attributed to R P Dawber.

At least 19 recordsLinked to original sources
PubMed1998

The incidence and prognosis of nail apparatus melanoma. A retrospective study of 105 patients in four English regions.

Our population-based study establishes epidemiological data on age-specific incidence rates, clinical presentation, Breslow microstaging, treatment and survival of nail apparatus melanoma (NAM) patients in England. Four cancer registries, covering a population of 10.6 million, recorded 105 cases of NAM during the period 1984-93. During the same decade there was a total of 7585 patients with cutaneous melanoma and NAM represents 1.4% of all cutaneous melanoma. The incidence rate of NAM in English patients is 0.1 per 100,000 of the population per annum. Amelanotic melanoma was the clinical presentation in 24 of our NAM cases. The overall prognosis is poor with an observed 5 year survival of only 51%. Patients with NAM less than 2.5 mm Breslow depth have a 5 year survival of 88% and are twice as likely to survive compared with those with tumours greater or equal to 2.5 mm in thickness (P < 0. 05). NAM patients are best managed by a multidisciplinary team approach in a few key skin cancer centres.

Adult↗
PubMed1998

Treatment of cutaneous Bowen's disease with particular emphasis on the problem of lower leg lesions.

Bowen's disease has a particular predilection for the lower leg, especially in women. A review of the literature for treating Bowen's disease is presented and the problems associated with treating the lower leg emphasized. Evidence for the various treatment modalities used to treat Bowen's disease largely comes from studies that lack good methodology in terms of standardized techniques, patient controls and adequate follow-up. In particular the widely accepted recommendation for excision is not supported by evidence that this treatment is superior to other modalities. The choice of treatment for Bowen's disease should take into account the patient's general condition, the site and size of the lesion.

Bowen's Disease↗
PubMed1998

Subungual squamous cell carcinoma presenting with minimal nail changes: a factor in delayed diagnosis?

Squamous cell carcinoma of the nail bed is a relatively uncommon tumour that may be diagnosed only after considerable delay. The first case presented is a 79-year-old man with a history of discomfort and discoloration affecting the right thumbnail of 3 years duration. The second case is a 70-year-old man who presented with a recurrent, offensive discharge from beneath the left thumbnail of 40 years duration. Clinical examination of the affected digits revealed minor nail abnormalities. The presence of tumour was fully apparent only after removal of the nail plate and inspection and biopsy of the nail bed. The cases demonstrate that subungual squamous cell carcinoma may present with prolonged symptoms and a deceptively benign appearance. The importance of consideration of the possibility of malignancy, removal of the nail plate for inspection of the nail bed and appropriate biopsy is emphasized.

Aged↗
PubMed1998

Erythrokeratoderma variabilis: case report and review of the literature.

We report two patients, mother and daughter, with Erythrokeratoderma variabilis (EV). This rare genodermatosis is characterized by the presence of two components: migratory erythema and fixed hyperkeratosis. Our patients experienced symptomatic relief of pruritus associated with erythema with the use of an oral, low-sedating H1-antihistamine. Revision of the literature in order to allocate the frequency of pruritus in EV and discussion of this association will follow.

Adolescent↗
PubMed1997

Treatment of lentigo maligna.

Lentigo maligna (LM) is the in situ phase of lentigo maligna melanoma (LMM) and, if left untreated, 30-50% of cases will progress to LMM, which is now thought to behave as aggressively as any other melanoma. Literature on the of treatment of LM including conventional surgery, micrographic Mohs surgery, cryosurgery, radiotherapy, electrodesiccation and curettage. 5-fluorouracil (5-FU), azelaic acid, retinoic acid and lasers are reviewed. It is concluded that micrographic Mohs surgery has the lowest recurrence rates and that conventional surgery, cryosurgery and radiotherapy all have recurrence rates in the order of 7-10%. Therefore, on the basis of the current literature available, all three of these methods could be recommended as primary treatment of LM. It is extremely important when choosing one of the above treatments that the physician is adequately trained in the appropriate technique and understands the limitation of the method used and the need for close follow up of the patient.

Chemotherapy, Adjuvant↗
PubMed1997

An organic refrigerant for cryosurgery: fact or fiction?

Dimethylether/propane is an organic substance used as a refrigerant in a new cryodelivery system marketed for the treatment of warts. The objective was first to determine the temperatures achieved by this delivery system, both at the end of the applicator and in the tissues and, second, to compare with liquid nitrogen delivered via standard cryospray equipment (CryAC). Temperature probes were used to measure temperature 1 mm below the epidermis of pig trotters after freezing with the two delivery systems for 20 and 40 s. After freezing with dimethylether/propane, results showed tissue temperatures were 3 degrees C at 20 s and 0 degree C at 40 s. Freezing with liquid nitrogen achieved -20 degrees C at 20 s and -57 degrees C at 40 s. It was concluded that dimethylether/propane does not achieve tissue temperatures below 0 degree C and is not recommended in the use of malignant or premalignant lesions.

Animals↗
PubMed1996

Linkage of monilethrix to the trichocyte and epithelial keratin gene cluster on 12q11-q13.

Monilethrix is characterized by beaded or moniliform hair, which results from the periodic thinning of the hair shaft. The beaded hair thus produced is subject to excess weathering and premature fracturing at the internodes. Clinically, monilethrix presents with short, fragile, broken hair. The follicular abnormalities range from subtle perifollicular abnormalities range from subtle perifollicular erythema and hyperkeratosis to horny follicular papule formation. At the ultrastructural level, cytolysis and keratin tonofilament clumping (epidermolysis) are seen in the cortical cells of the bulb of the hair follicle. Microsatellite markers flanking the keratin gene clusters at 17q12-q21 and 12q11-q13 were used to perform linkage analysis in a monilethrix pedigree. This study demonstrates linkage of monilethrix in a pedigree to microsatellite DNA loci mapping to the region on chromosome 12 containing the type II keratin cluster. A major group of structural hair proteins, the basic type II trichocyte keratins, map within this epithelial cytokeratin gene cluster. This study implicates a mutation in a trichocyte keratin gene in the pathogenesis of a structural hair disorder.

Chromosomes, Human, Pair 12↗
PubMed1995

Cryosurgery of malignant and premalignant diseases of the skin: a simple approach.

Cryosurgical treatment of skin cancer and premalignant conditions of the skin has been in widespread use for 20 years. Data accumulated over this period suggest that if attention is paid to the treatment technique and to lesion selection, then cure rates equivalent to radiotherapy, simple surgical excision, and curettage and cautery can be achieved reliably. Moh's micrographic surgery offers a higher cure rate for skin cancer, but is not suitable for the vast majority of lesions seen in clinical practice. The decision to use cryosurgery to treat any particular lesion will therefore be influenced by a number of other considerations. Cryosurgery competes well on morbidity and cosmetic outcome and is the quickest, easiest, cheapest and most readily available of the treatment options. As such it has earned its place among the recognized treatment modalities for skin cancers as well as premalignant conditions of the skin. Cryosurgery is commonly delivered empirically without record of the dose delivered and without audit of the outcome. The aim of this review is to describe in detail one standard technique of therapy that is easily reproduced and has been audited; the timed spot freeze technique. This technique can be used, even by those inexperienced in cryosurgery, to achieve predictable success rates. Many other techniques do exist, but either have not been audited or are unnecessarily cumbersome.

Basal Cell Carcinoma↗
PubMed1995

Golf tee hairs in Netherton disease.

We present a case of Netherton disease, where the hairs lacked the characteristic microscopic feature of trichorrhexis invaginata. In its place were certain hairs with a golf tee morphology. These represent the proximal half of the invaginate node seen in typical Netherton disease. Scanning electron microscopy demonstrated the three-dimensional quality of this abnormality, which is subtle when assessed by light microscopy alone. We describe this sign so that it might be recognized when seen in isolation, as here, and allow the diagnosis of Netherton disease to be confirmed.

Child, Preschool↗
PubMed1994

Alopecia neoplastica without alopecia: a unique presentation of breast carcinoma scalp metastasis.

The scalp is a relatively common site of cutaneous metastasis. The usual presentation is of single or multiple firm scalp nodules. A well-recognized but rarer presentation is alopecia neoplastica that is seen as single or multiple areas of cicatricial alopecia. We describe a unique presentation of scalp metastasis in a patient with breast carcinoma in whom hair loss was clinically inconspicuous. The metastasis responded to combination chemotherapy.

Adenocarcinoma↗
PubMed1994

Cheveux incoiffables--diagnostic, clinical and hair microscopic findings, and pathogenic studies.

Three possible mechanisms of the hair shaft abnormality in cheveux incoiffables have been investigated in nine patients. Cheveux incoiffables hairs were found to exhibit a normal distribution of cystine-rich protein within both the cuticle and the cortex, as determined by silver methenamine ultrastructural cytochemistry. Resistance to stretching, at 65% relative humidity and constant temperature, was similar to normal controls. Resistance to bending forces was also assessed, and was equivalent in both groups. On scanning electron microscopy, all patients with cheveux incoiffables demonstrated longitudinal grooving of the hair shaft, and the hairs were triangular or heart-shaped in cross-section. In addition, there appeared to be minimal cuticular weathering. Even hairs of 20-30 cm length showed only minimal cuticular and cortical weathering, compared with normal hair shafts of similar length and diameter. It is possible that the reduced progressive weathering renders the hair shaft more rigid, and could serve to explain the 'stand on end' appearance of the hair which is typical of this condition. However, the characteristic cross-sectional shape of the hair shaft in cheveux incoiffables may render it more rigid and resistant to bending forces. This latter theory has yet to be fully investigated.

Child↗