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Biomedical subjects

J M Marks

Publications and source records attributed to J M Marks.

At least 37 records · Page 2Linked to original sources

Laparoscopic repair of a diaphragmatic laceration.

The role of laparoscopy in the management of trauma patients has yet to be determined. In the stable patient, laparoscopy can be used to verify peritoneal penetration and intra-abdominal organ injuries. This report describes a diaphragmatic laceration in a 17-year-old boy secondary to a single stab wound. This injury of the left hemidiaphragm was identified and repaired using laparoscopic techniques. This case demonstrates the value of laparoscopy as both a diagnostic and a therapeutic tool in the management of trauma patients.

Adolescent↗

Dermatology examination performance: wide variation between different teaching centres.

Three hundred and one clinical medical students in four universities took the same 50 question MCQ dermatology examination after their dermatology teaching. In one centre, half the students had had additional teaching; these students performed better (mean score 47.5%, n = 29) than those who had no extra teaching (mean score 40.9%, n = 29). In another centre, the students' mean score improved from 24.1 (SD = 6.7) before to 41.6 (SD = 7) (n = 46, P < 0.001) after their dermatology teaching. The different subject areas covered by the examination were analysed separately. In the lowest scoring centre (mean score 34.0, SD = 9.4) the students scored lowest in 9 of the 14 subject areas. In the highest scoring centre (mean score 47.5, SD = 9.9) students scored highest in 7 of these 14 subject areas. This study enabled questions of high discriminatory value to be identified for future use. The use of the same examination in different centres provides feedback for the centres concerning strengths and weaknesses of their teaching.

Dermatology↗

Dermatitis herpetiformis and established coeliac disease.

Fifteen (5.3%) of 282 patients with dermatitis herpetiformis (DH) were diagnosed as suffering from coeliac disease before the onset of their DH. This group showed a female preponderance, and a later than usual onset of DH. The mean age at which DH developed was 40.0 years, and there was a mean interval of 13.2 years between the two diagnoses. Seven patients had stopped their gluten-free diet, and a further four were poor compliers. Persistent gluten ingestion in coeliacs with a specific genetic predisposition may result in the development of DH.

Adolescent↗

Prevalence of skin and other cancers in patients with psoriasis.

The prevalence of skin and internal malignancies was estimated from the general practitioners' notes of 2247 patients with psoriasis and 4494 age- and sex-matched controls. The prevalence of skin cancer in the psoriatics was 155% that of controls, but this was not significant at the 5% level. Subgroup analysis showed an increase in skin cancers in women (P < 0.05). There was no difference in the age of onset of skin cancers between psoriatics and controls and there was no evidence of a cumulative therapeutic risk. There was no difference in the prevalence of non-skin cancers between psoriatics and controls.

Adult↗

Pheomelanin as well as eumelanin is present in human epidermis.

There are two types of melanin in mammals, the brownish black eumelanin and the reddish yellow pheomelanin. Eumelanin and pheomelanin are present in human hair and this study was carried out to see whether both pigments are also present in human epidermis. Samples of epidermis were obtained from suction blisters raised in the upper arm of 13 Caucasian subjects of skin types I, II, and III and analyzed for both eumelanin and pheomelanin using a procedure involving high-performance liquid chromatography. Eumelanin and pheomelanin were found in all epidermal samples and their relative proportions correlated well with those found in samples of hair taken from the same subjects. The lowest concentrations of eumelanin were found in subjects of skin type I, with higher levels in skin types II and III. The concentrations of pheomelanin were more variable and showed no relationship to skin type. Increases in the concentrations of both pigments occurred following PUVA therapy, but whereas the largest increases in eumelanin were seen in skin types II and III, the increases in pheomelanin showed little relationship to skin type. Unlike eumelanin, epidermal pheomelanin also showed little relationship to PUVA-induced tanning. The present findings could be particularly significant in view of recent suggestions that pheomelanin, rather than protecting the skin against UV radiation, may actually contribute to UV-induced skin damage.

Epidermis↗

Cyclosporin A in atopic dermatitis: therapeutic response is dissociated from effects on allergic reactions.

Fourteen patients with severe chronic atopic dermatitis were treated with cyclosporin A (CyA, Sandimmun; 5 mg/kg/day) for 7-16 weeks. All showed a marked clinical improvement and half could omit topical corticosteroid treatment during therapy. Adverse effects were minor, but two patients relapsed despite continued treatment. In the others, the disease recurred soon after stopping CyA. Serum IgE levels and prick-test responses were unchanged by CyA. Immediate and late-phase cutaneous responses to intradermal house dust mite antigen (HDM) were significantly increased during treatment; but a delayed response, present at 24 and 48 h, was unaffected. Four of six patients challenged with HDM patch tests to tape-stripped skin during treatment showed eczematous reactions at 48 h. Thus, cyclosporin A has a powerful therapeutic effect in atopic dermatitis but does not reduce allergic responses to inhalant antigens.

Adolescent↗

Seasonally recurrent granuloma annulare of the elbows.

Granuloma annulare may be recurrent and various precipitating factors have been described but seasonal cases have not been previously reported. We describe two patients with granuloma annulare on the elbows which developed in spring and resolved spontaneously in October each year. We believe that this type of seasonally recurrent granuloma annulae has not been previously described.

Adult↗

[Cyclosporin A in atopic dermatitis: therapeutic effect and effect on allergic reactions are dissociated from each other].

Fourteen patients with severe chronic atopic dermatitis were treated with cyclosporin A (CyA, Sandimmun; 5 mg/kg/day) for 7-16 weeks. All showed a marked clinical improvement and half could omit topical corticosteroid treatment during therapy. Adverse effects were minor, but two patients relapsed despite continued treatment. In the others, the disease recurred soon after stopping CyA. Serum IgE levels and prick-test responses were unchanged by CyA. Immediate and late-phase cutaneous responses to intradermal house dust mite antigen (HDM) were significantly increased during treatment; but a delayed response, present at 24 and 48 h, was unaffected. Four of six patients challenged with HDM patch tests to tape-stripped skin during treatment showed eczematous reactions at 48 h. Thus, cyclosporin A has a powerful therapeutic effect in atopic dermatitis but does not reduce allergic responses to inhalant antigens.

Adolescent↗

Tyrosinase synthesis in different skin types and the effects of alpha-melanocyte-stimulating hormone and cyclic AMP.

Tyrosinase synthesis and its regulation in human melanocytes was studied by measuring the incorporation of [35S] methionine into incubated skin biopsies. Tyrosinase was detected in all skin samples with the highest levels in skin type IV and the lowest levels in skin type I. Following psoralen ultraviolet A (PUVA) therapy for several weeks, significant increases in the amounts of tyrosinase were found in skin types III and IV. The presence of alpha-melanocyte-stimulating hormone (alpha-MSH) (100 mumol/l) or the long-acting analogue [Nle4, DPhe7] alpha-MSH (1-10 mumol/l) in the incubation medium failed to alter tyrosinase levels in the skin biopsies taken from patients both before and after receiving PUVA therapy. Bromo-adenosine 3,5-cyclic monophosphate sodium salt (8-bromo-cAMP) (10 mmol/l), on the other hand, increased the amounts of tyrosinase both before and after PUVA, but these effects were only seen in biopsies of type III and IV skin. These results indicate that MSH fails to stimulate tyrosinase synthesis in human melanocytes. Nevertheless, tyrosinase synthesis and its regulation by cyclic AMP-dependent mechanisms could be important control points in the pigmentary response.

8-Bromo Cyclic Adenosine Monophosphate↗