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Biomedical subjects

C M Perret

Publications and source records attributed to C M Perret.

18 recordsLinked to original sources
PubMed1994

Cytokeratin expression in alopecia areata hair follicles.

Alopecia areata is a human hair disease of unknown etiology. Immunological mechanisms, alterations in the extracellular matrix and follicular growth abnormalities have been suggested as a possible cause. Here we compare the expression of cytokeratins in normal hair follicles to that of alopecia areata using immunohistology with monoclonal antibodies. A number of cytokeratins were specifically expressed in defined anatomical parts of the follicle; however, no gross qualitative or quantitative differences were found between normal and diseased scalp. Interestingly, the expression of cytokeratin 16, which is modulated by conditions that affect the rate of keratinocyte proliferation, was found to be unchanged in the outer root sheet of alopecia areata follicles. This is in contrast with earlier observations of a decrease in the expression of the proliferation-associated, Ki-67 nuclear antigen.

Alopecia Areata↗
PubMed1992

Abnormal expression of Ki-67 antigen in hair follicle of alopecia areata.

The monoclonal antibody Ki-67 was used to determine the numbers of cycling cells in hair follicles both in alopecia areata and in normal scalp skin. Pronounced nuclear staining was limited to the area below the critical line of Auber and the exterior part of the outer root sheath. In alopecia areata there is reduced nuclear Ki-67 binding in the bulb of anagen hair follicles. These findings indicate that inhibition of keratinocyte proliferation might be a pathogenetic mechanism in alopecia areata.

Alopecia Areata↗
PubMed1991

Expression of tenascin in perifollicular connective tissue: comparison of normal scalp and alopecia areata.

Tenascin, a recently discovered extracellular matrix protein, was demonstrated in perifollicular connective tissue of normal human scalp using immunohistochemistry. Its localization was different from other well-known extracellular matrix components, like fibronectin, laminin and heparan sulphate proteoglycan. A comparison between alopecia areata and normal scalps did not reveal major qualitative differences, except for an increased expression near heavily infiltrated follicles.

Alopecia Areata↗
PubMed1991

Prognostic factors in the treatment of alopecia areata with diphenylcyclopropenone.

One hundred thirty-nine patients with alopecia areata were treated with diphenylcyclopropenone. Before treatment, 85 patients had subtotal or total hair loss (greater than 90% bald area) and in the remaining patients scalp involvement was between 40% and 90%. The following three factors were found to be of prognostic significance: type of alopecia areata as documented before treatment, duration of the disease before therapy, and presence of nail changes. Other factors such as age at onset, sex, presence of atopic features, the extent of variation in the range of diphenylcyclopropenone concentrations during treatment, and sleep disturbances caused by pruritus did not influence the prognosis significantly.

Adolescent↗
PubMed1991

Treatment of alopecia areata with diphenylcyclopropenone.

One hundred thirty-nine patients with severe alopecia areata (the majority with the subtotal, total, or universalis type) were treated with topical immunotherapy (diphenylcyclopropenone). Patients were initially treated unilaterally; the other side of the scalp served as a control. In 50.4% of the patients the response was either excellent (total regrowth) or satisfactory (subtotal regrowth with only a few remaining bald patches). The most frequent side effects were eczematous reactions with blistering, spreading of the induced contact eczema, and sleep disturbances.

Administration, Topical↗
PubMed1990

Ichthyosis bullosa of Siemens: further delineation of the phenotype.

We report a third family affected with ichthyosis bullosa of Siemens, and we further delineate the clinical spectrum of this mild type of epidermolytic hyperkeratosis. Erythroderma had never been present in any of the affected individuals. All of them exhibited a brownish, rimpled hyperkeratosis, the main characteristic sites being the joints, the shins and the periumbilical region. Blistering occurred after slight mechanical trauma and even after sweating, resulting in superficially denuded areas. Two affected family members also suffered from chronic, relapsing pustular eruptions surrounded by a transient erythematous flare. Light- and electron-microscopic examination revealed epidermolytic hyperkeratosis limited to the upper part of the epidermis. The pustular lesions were found to be subcorneal blisters filled with neutrophils. Ichthyosis bullosa of Siemens can be clearly distinguished from bullous ichthyosiform erythroderma. The observation of subcorneal pustular dermatosis occurring in this phenotype provides further evidence for the genetic heterogeneity of epidermolytic hyperkeratosis.

Acitretin↗
PubMed1990

Erythema multiforme-like eruptions: a rare side effect of topical immunotherapy with diphenylcyclopropenone.

We report 3 cases of erythema multiforme following topical application of diphenylcyclopropenone (DCP) for the treatment of alopecia areata. This eruption represents a rare side effect which could be controlled with corticosteroids given both systemically and topically. When this unusual reaction occurred, treatment with DCP was stopped. In one of the patients, subsequent topical immunotherapy with squaric acid dibutylester was not complicated by this side effect and resulted in complete hair regrowth.

Administration, Topical↗
PubMed1990

Cryosectioning of hair follicles. An improved method using liquid nitrogen conduction freezing.

Horizontal sectioning of scalp biopsies is especially useful in hair diseases characterized by a reduction of follicles in size or number. Horizontal sectioning using standard cryo-microtomes is hampered by the differences in cutting properties between hair follicles and fatty tissue, resulting in loss of topography. We report a simple, inexpensive method to temporarily cool the specimen to an appropriate temperature by means of a conduction system using liquid nitrogen. Immunohistological methods such as immunofluorescence and immunoperoxidase techniques can be applied without restrictions.

Alopecia Areata↗
PubMed1989

Contact sensitivity to diazolidinyl urea (Germall II).

Diazolidinyl urea (DU; trade name Germall II), a new broad spectrum preservative, was tested from July 1984 to September 1988 in 2400 consecutive patients with eczemas possibly caused or complicated by a contact allergy. In addition to the European standard series (Trolab), a supplementary test battery including DU 2% in water was used. A sensitization to DU was seen in 13 patients (0.54%). Of 13 patients 7 reacted only to DU, but not to formaldehyde (FA) or FA releasers; in these patients, the reaction can be attributed to sensitivity to DU itself. Six of the 13 patients reacted to DU as well as FA and all FA releasers tested; in these patients, the reaction to DU is probably due to released FA. For practical reasons, DU should be added to the list of FA releasers. In some of the patients, concomitant sensitization to frequent contact allergens such as nickel, cobalt, chromate, or a long history of skin disease could be found; it seems reasonable to assume that in these cases the sensitization to DU was enhanced by an eczematous skin with a reduced barrier function. Patients reacting to FA should be advised to perform a repeated open application test (ROAT) before using a cosmetic containing DU as a preservative, to prevent possible adverse effects from released FA.

Adult↗
PubMed1988

[Goltz-Gorlin syndrome without focal dermal hypoplasia].

An unusual type of pigmentary disturbance is described in a 24-year-old man. The skin lesions consisted of patchy hyperpigmentation and hypopigmentation intermingled with teleangiectasias. They were distributed in a nevoid pattern following the lines of Blaschko. The patient had, in addition, multiple skin-colored papules in the cranial area of the gluteal fold, a fovea coccygea, and mild clinodactyly of both hands. Histopathologically, the dermis was of normal thickness and herniation of subcutaneous adipose tissue was absent in all five biopsies. This phenotype can be best explained as a case of Goltz-Gorlin syndrome without focal dermal hypoplasia. If this holds true, focal dermal hypoplasia in terms of a reduced thickness of the dermis is no longer a prerequisite for the diagnosis of the Goltz-Gorlin syndrome.

Adult↗
PubMed1987

Extensive necrobiosis in metastatic Crohn's disease.

This report is on a 33-year-old female patient with Crohn's disease of the intestine and nonhealing leg ulcers which histologically showed the typical noncaseating epithelioid granulomas of sarcoid structure defining the so-called 'metastatic Crohn's disease'. Furthermore, as a very rare pattern, extensive necrobiotic areas surrounded by sarcoid granulomas were observed.

Adult↗