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Biomedical subjects

A J Mitchell

Publications and source records attributed to A J Mitchell.

At least 37 records · Page 2Linked to original sources
PubMed1995

Microbial colonization of the Groningen speaking valve and its relationship to valve failure.

Speaking valve failure may be related to biofilm development. An inter-observer validated method of assessing microbial overgrowth in defective prostheses was developed. Two independent observers recorded colonisation of the valves on a 100 mm linear analogue scale in several defined areas. Inter-observer agreement was high in all areas. In vitro opening pressure and derived forward resistances were measured. The relationship between colonization of the valves and the in vitro measurements was investigated. Significant correlations for a two-tailed Spearman's test were recorded between the resistance and microbial colonization of the hinge and oesophageal areas (rs 0.22: P < 0.05, rs 0.25: P < 0.05, n = 80). There was no significant association for resistance and colonization of the tracheal surface, and no significant association between the opening pressure and the colonization. This work suggests that microbial colonization of the prosthesis in the oesophageal and hinge areas is associated with valve failure.

Colony Count, Microbial↗
PubMed1987

Epidermodysplasia verruciformis. A case associated with primary lymphatic dysplasia, depressed cell-mediated immunity, and Bowen's disease containing human papillomavirus 16 DNA.

Epidermodysplasia verruciformis is a rare, often hereditary disease characterized by a generalized cutaneous infection with human papillomavirus (HPV), depressed cell-mediated immunity, and a propensity for transformation of the warty lesions to squamous cell carcinoma on primarily sun-exposed areas of the skin. A 37-year-old man with congenital lymphatic dysplasia and a history of squamous cell carcinoma of the groin and foot was observed by us to have edema of all four extremities, numerous flat warts, and pityriasis versicolor-like papules over the trunk and arms. Condylomatous lesions were noted in the groin and a periungual verrucous nodule on the thumb. Biopsies showed the trunk and arm lesions to be verrucae and the thumb lesion to be Bowen's disease. Results of molecular hybridization studies from four lesions of the arms showed the presence of only HPV 3 DNA; HPV 16-related DNA was detected in the intraepidermal carcinoma on the thumb. Immunologic evaluation revealed anergy to routine skin testing, depressed mitogen-stimulated lymphocyte transformation, decreased B-lymphocyte count, and a severe reversal of the T-lymphocyte helper:suppressor ratio.

Adult↗
PubMed1987

Alopecia areata, endocrine function, and autoantibodies in patients 16 years of age or younger.

Forty-five children with alopecia areata were prospectively studied by means of both clinical and laboratory evaluation for evidence of endocrine diseases and autoantibodies. Twenty-four percent had an abnormality as determined by one or more thyroid function studies (thyroxine, triiodothyronine, and thyroid-stimulating hormone) and/or elevation of microsomal antibody levels. In 16%, smooth muscle antibody was present, and in 4%, parietal cell antibody was present. Routine thyroid function testing is recommended for all children with alopecia areata.

Adolescent↗
PubMed1987

Alopecia areata.

Although a specific etiology remains undetermined, most evidence points to an autoimmune pathogenesis for alopecia areata. Treatments for alopecia areata are likely to remain palliative until its etiology is better understood. Even it prolonged remissions cannot always be achieved with the treatments presently available, preservation of hair regrowth with maintenance therapy is a reasonable goal. When this is not possible, the value of supportive interaction with patient and family should not be minimized, as the psychologic effects of the disease can be great. Support groups such as those sponsored by the Alopecia Areata Foundation cna assist the physician in this endeavor.

Alopecia Areata↗
PubMed1986

Confluent and reticulated papillomatosis responsive to selenium sulfide.

Confluent and reticulated papillomatosis of Gougerot and Carteaud (CRP) is a distinctive clinicopathologic entity, of unknown etiology, which shows some resemblance to pityriasis versicolor. A case of CRP that showed a significant therapeutic response to topical selenium sulfide is reported. In previously described cases, response to this agent and to other medications, both antifungal and keratolytic, has been variable. A review of these cases reveals conflicting evidence regarding the questionable role of Malassezia furfur in CRP.

Administration, Topical↗
PubMed1985

Topical photochemotherapy for alopecia areata.

Twenty-two patients with alopecia areata were treated with a combination of topical 0.1% 8-methoxypsoralen and UVA (PUVA). Eight of the twenty-two patients (36.3%) responded with excellent regrowth (terminal hair in at least 75% of the treated scalp), and two patients (9.1%) showed good regrowth (terminal hair in 50% to 75% of the treated scalp). The mean total UVA exposure and the mean total number of treatments for the entire treatment course for these responders was 171.7 joules/cm2 and 47.4 treatments, respectively. Eight of the nine responders available for follow-up experienced some degree of relapse when PUVA treatments were tapered or during a follow-up period (mean, 8.3 months) after treatment was discontinued. Despite the failure of topical PUVA to change the long-term course of alopecia, the combination of PUVA with other therapeutic modalities may result in the prolongation of the beneficial effect in selected patients. The mechanism of action of PUVA in alopecia areata might involve an immunomodulatory effect.

Adolescent↗
PubMed1985

Cutaneous B cell lymphoma: diagnostic use of monoclonal antibodies.

A patient presented with a solitary plaque initially interpreted on light microscopy as benign lymphoplasia. Monoclonal antibody studies were used to define the B cell origin of the infiltrate and to characterize its probable malignant potential. Monoclonal antibody typing is a useful technique to evaluate lymphocytic infiltrates that may be difficult to categorize on the basis of routine light microscopy.

Antibodies, Monoclonal↗
PubMed1984

Topical therapy of alopecia areata with squaric acid dibutylester.

The efficacy of the topical allergen squaric acid dibutylester (SADBE) was investigated in the treatment of twenty-six patients with alopecia areata or alopecia totalis. The patients had their disease for a mean duration of 8.3 years (range, 3 months to 27 years). Sensitization was attempted with 2% SADBE in acetone. Five individuals could not be sensitized. The twenty-one sensitized patients were treated with topical applications of 0.001% to 1.0% SADBE in acetone adjusted to produce and maintain dermatitis for an average of 21 weeks. Eleven (52%) had excellent responses consisting of complete regrowth in six and cosmetically acceptable regrowth in five. The average treatment time for regrowth was 11 weeks (range, 5-20 weeks). Ten (48%) had no clinical response after an average of 19 weeks of therapy (range, 4-42 weeks). Topical SADBE is an effective therapy for some patients with long-standing alopecia areata.

Administration, Topical↗
PubMed1984

Alopecia areata: pathogenesis and treatment.

Although its etiology remains unknown, evidence has accumulated to support an autoimmune pathogenesis for alopecia areata. Our review summarizes the immunologic data and also examines the role of genetics, atopy, and psychologic stress in this disorder. Until etiology is better understood, treatments for alopecia areata are likely to remain palliative. Nevertheless, newer therapies such as photochemotherapy, topical immunotherapy, and perhaps systemic immunotherapy (e.g., inosiplex) offer new hope for patients with extensive disease.

Adrenal Cortex Hormones↗
PubMed1984

Recurrent granulomatous dermatitis with eosinophilia. Wells' syndrome.

A 27-year-old woman developed a chronic, recurrent eruption of the face and upper extremities with the clinical and histopathologic features of recurrent granulomatous dermatitis with eosinophilia (Wells' syndrome). As described in 15 previously reported cases, this disorder is characterized by two clinical phases (eosinophilic cellulitis and granulomatous plaque phase) and three histopathologic stages. The latter are particularly remarkable for a diffuse dermal and subcutaneous eosinophilia in acute lesions and scattered flame figures in chronic lesions. Distinctive findings in this case were the predominance of facial involvement and the symptomatic response to topical corticosteroids. Although etiology and pathogenesis are unknown, we feel that Wells' syndrome is a unique yet rarely recognized clinicopathologic entity.

Adult↗
PubMed1983

Subcutaneous alternariosis.

Alternaria species are common plant pathogens, but a rare cause of human infection. Previously reported cases of cutaneous alternariosis (Alternaria alternata) in both healthy and immunosuppressed hosts have been characterized by a chronic localized ulcerative eruption in exposed sites. Dermal granulomatous infiltration and variable epidermal changes, with hyphae in both the dermis and epidermis, are characteristic. We present a case with certain unique features. This is the first reported human infection with Alternaria dianthicola. In addition, our patient showed the unusual presentation of clinically noninflammatory subcutaneous nodules of the chest wall. The subcutaneous location of the granulomatous process may have been attributable to deep traumatic inoculation. The circumscribed nodular quality of the infection allowed a surgical therapeutic approach.

Alternaria↗
PubMed1982

Pathogenicity and histopathology of an unusually intense infection of white grubs (Posthodiplostomum m. minimum) in the fathead minnow (Pimephales promelas).

A massive infection of metacercariae, particularly of the white grub (Posthodiplostomum m. minimum), was found in fathead minnows (Pimephales promelas) taken in November, 1979 from a commercial baitfish farm in Missouri. More than 2000 metacercariae were found in one fish 6 cm long. Low-grade mortality was occurring, and histologic sections showed that an intensive inflammatory response had resulted from the infection. The body cavity also contained a large volume of ascitic fluid with many blood cells, of which 92% were leucocytes. Moderate numbers of metacercariae caused a lesser inflammatory response.

Animals↗