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D De Berker

Publications and source records attributed to D De Berker.

At least 19 recordsLinked to original sources
PubMed2000

Keratin expression in the normal nail unit: markers of regional differentiation.

Differentiation within the nail unit was examined using a range of antikeratin monoclonal antibodies including the recently described antibody LHTric-1, specific to the acidic hair-type keratin Ha1. Keratinocytes of the nail matrix, nail bed and the digit pulp were characterized by different patterns of keratin expression. Nail matrix was the sole site of expression of Ha1, which colocalized in suprabasal matrix epidermis with epidermal keratins K1 and K10. Small amounts of K17 were found at the apex of the matrix in some cases. K6 and K16 were found where the epidermal surface folds forwards to become the ventral aspect of the proximal nail fold. The nail bed was distinguished by the absence of hair-type keratin Ha1 and the absence of markers of cornified epidermis and mucosal differentiation K1/K10 and K4/K13, respectively, while K6, K16 and K17 were detected. The basal keratin conformation marker, LH6, was expressed suprabasally throughout the nail bed. This complement of keratins exists in the nail bed in the absence of notable proliferative activity, and suggests a state of minimally developed differentiation which may be afforded by the physical or biological properties of the overlying nail. Keratins, K6, K16 and K17 were all found in the digit pulp in limited amounts, possibly in association with the epidermal component of the eccrine duct. The simple epithelial keratins, K7, K8 and K18, were found in small amounts in the specimens from younger individuals, mainly in epibasal cells of the apex of the matrix and in putative Merkel cells.

Cell Differentiation↗
PubMed1997

Characterization of LHTric-1, a new monospecific monoclonal antibody to the trichocyte keratin Ha1.

The hair follicle is a heterogeneous tissue involving differentiation of both hair forming (trichocyte) and non-hair forming (root sheath) cells; while there are many antibody markers available which can determine the distribution of 'soft' epithelial keratins, fewer have been described which are truly monospecific for hair specific 'hard' keratins. We employed the proven strategy of raising monoclonal antibodies to a short synthetic peptide from the carboxy-terminal sequence of mouse Ha1 and report here the successful production of a monospecific monoclonal antibody which we have called LHTric-1. We have characterized the antibody using immunostaining on rat and human tissues and by immunoblotting against an extract of human follicles. The antibody cross-reacted between rat and human tissue but did not stain formalin-fixed tissue. LHTric-1 localized very specifically to the pre-cortical region of the hair follicle in early anagen and to pre-cortical cells in the upper bulb in anagen. Telogen follicles did not react. LHTric-1 immunoreacted within tongue and nail, staining being restricted to the mid-line above the connective tissue core in tongue and to the suprabasal layers of the nail matrix. The antibody did not react with the fully keratinized hair or nail plate. Finally, in immunoblotting, LHTric-1 reacted with a single band of 44 kDa, suggesting that a single protein was recognized. We conclude that this antibody, by virtue of its known antigen sequence specificity, will be useful in research into the formation of hair and nail in normal and diseased states.

Animals↗
PubMed1997

The scleroatrophic syndrome of Huriez.

We have examined 14 of 28 members of a four-generation family, 10 of whom demonstrated the clinical features of the scleroatrophic syndrome of Huriez, a cancer-prone dermatosis. Several members of this family demonstrated additional features, previously unrecorded in this syndrome, including poikiloderma-like changes on the nose, flexion contractures of the little finger, a distinctive little finger nodule, and telangiectasia on the lips. Genetic linkage was excluded to distal chromosome 4q (LOD score-4.399 at theta = 0.001). This concurs with the recent reappraisal study of one of the two original families described by Huriez, in which no evidence of linkage between this syndrome and the MNSs erythrocytic system (mapped to 4q28-q31) was found. This is the first report of a family from the U.K. with this syndrome.

Adolescent↗
PubMed1996

Spontaneous regression in angiocentric T-cell lymphoma.

An 8-year-old boy presented with a 10-week history of ulcerating lesions which were histologically and immunocytochemically consistent with the diagnosis of angiocentric T-cell lymphoma. The disease was limited to the skin and resolved with no chemotherapy. Angiocentric T-cell lymphoma is commonly a disease with considerable morbidity and is often fatal. Epstein-Barr virus (EBV) could not be identified in involved tissue by immunostaining or by in situ hybridization. We consider whether the uncharacteristic absence of EBV in this case has prognostic significance.

Child↗
PubMed1996

Quantification of regional matrix nail production.

The relative nail producing capacity of different regions within the nail matrix has not been quantified. In order to do this, the number of nail plate cells in the dorsoventral axis of 12 human great toenails was counted at five sites in the longitudinal axis, and compared with direct measurements of nail plate thickness at the same sites. The mean number of nail cells in the nail plate reached a maximum at the lunula, with no further increase along the length of the nail bed. At the mid-point between the proximal tip of the germinal matrix and lunula, mean cell numbers achieved 81% of the value at the lunula. Mean nail thickness was only 90% of its maximum at the lunula, with a further significant increase (P = 0.02) between the lunula and end of the nail bed. These observations suggest that the proximal nail matrix is the main source of nail within the matrix. This is consistent with clinical experience where distal matrix surgery has a low potential for scarring in comparison with proximal matrix surgery. The additional finding of increased nail thickness, but not cell numbers, along the nail bed make it likely that cells within the nail plate change shape as they move distally.

Adolescent↗
PubMed1995

Normal sweat secretion rate in patients with alopecia areata.

We have examined sweat secretion rates in 22 patients with alopecia areata, and 22 age- and sex-matched controls. Mean sweat rate on the forearm in patients with alopecia areata was 20 mg/cm2 per h (95% confidence limits 15-25 mg/cm2 per h), and in controls was 24.1 mg/cm2 per h (95% confidence limits 19.1-29.1 mg/cm2 per h). Sweat secretion was higher in males than females in both the disease and control groups (27.8 mg/cm2 per h [95% confidence limits 21.3-34.3 mg/cm2 per h], compared with 18.08 mg/cm2 per h [95% confidence limits 14.63-21.6 mg/cm2]; P > 0.01). Our results confirm the previously reported sex difference in sweat secretion rate, and demonstrate that there is no statistically significant difference between patients with alopecia areata and controls. We discuss our results in the light of a previous report claiming that patients with alopecia areata have reduced rates of cholinergic-induced sweating.

Adult↗
PubMed1995

Keratin expression in cutaneous lichen planus.

The characteristic expression of keratins by keratinocytes is well documented. A typical 'hyperproliferative' profile of epidermal keratin expression occurs in psoriasis, wound healing and warts. This study analyses keratin expression in cutaneous lichen planus to determine abnormalities of differentiation occurring in this inflammatory disorder. Using a panel of monoclonal antibodies 28 samples (20 patients) were studied. The results showed that squamous differentiation was unaffected, with keratins K1 and K10 being expressed normally for the site sampled. The main abnormalities included extension of reactivity of the basal cell marker, LH8, into the suprabasal compartment. Keratin K17, usually restricted to adnexal structures, was variably expressed in the basal and suprabasal layers of the interfollicular epithelium of affected epidermis. Keratins K6 and K16, found suprabasally in hyperproliferative states, were detected both basally and suprabasally in all diseased samples. The keratin profile in lichen planus is analogous to the wound healing response. Suprabasal keratin K17 is found in psoriasis, wound healing and viral warts so the changes in keratin K17 may reflect hyperproliferative changes. It is likely that the changes in epidermal keratin expression are due to up-regulation of specific keratin genes by the production of cytokines and inflammatory mediators from the lymphocytic infiltrate typical of lichen planus.

Antibodies, Monoclonal↗
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↗
PubMed1992

Bullous and haemorrhagic lichen sclerosus with scalp involvement.

We describe a patient who developed a generalized blistering eruption due to lichen sclerosus and who was observed to have scalp involvement. Both are unusual manifestations of this disease which merit consideration. Lichen sclerosus is an uncommon disease that most frequently affects the external genitalia of perimenopausal women. The aetiology is unknown. Approximately 20% of affected patients have extragenital lesions that present as small, ivory, shiny round macules or papules that later become atrophic; extragenital lesions are generally asymptomatic. Bullous and haemorrhagic forms may occur but these are generally localized and reports of extensive or generalized involvement are rare. We describe an elderly woman with generalized bullous lichen sclerosus. As an incidental finding, she was observed to have lichen sclerosus affecting her scalp. This has rarely been described and it would appear that she is the third reported case of scalp involvement.

Aged↗