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Biomedical subjects

L Secher

Publications and source records attributed to L Secher.

At least 19 recordsLinked to original sources

The dermatoscopic ABCD rule does not improve diagnostic accuracy of malignant melanoma.

The dermatoscopic ABCD rule has been suggested to improve diagnostic performance regarding cutaneous malignant melanoma. Using this rule, a total dermatoscopy score is calculated from the presence of various dermatoscopic elements. A total dermatoscopy score above 4.75 signifies possible and 5.45 probable melanoma. We compared the diagnostic accuracy of dermatoscopy with and without the use of the ABCD rule. Furthermore, receiver operating characteristic analysis was performed for the ABCD rule. The area under the receiver operating characteristic curve was 0.854 (range 0.777-0.906) demonstrating that in 85.4% of the cases, cutaneous malignant melanomas were rated higher than the non-melanoma skin lesions. Sensitivity for the melanoma diagnosis was higher for simple dermatoscopy than when the ABCD rule was used (p<0.05). There was no difference in specificity when a total dermatoscopy score of 4.75 was used as cut-off point, but specificity was lower for simple dermatoscopy than when the total dermatoscopy score of 5.45 was used. Diagnostic accuracy was higher for simple dermatoscopy than for the ABCD rule (p<0.01). In conclusion, the dermatoscopic ABCD rule was not superior to simple dermatoscopy, and fewer malignant melanomas were identified with this rule.

Biopsy, Needle↗

Clinical and dermatoscopic diagnosis of malignant melanoma. Assessed by expert and non-expert groups.

We investigated the nosographic and diagnostic probabilities and likelihood ratios of dermatoscopy in order to evaluate the method's role in decision-making regarding melanoma. Clinical slides and dermatoscopic photos were obtained from 232 patients referred for dermatoscopy. Four dermatoscopy "experts" and 5 "non-experts" assessed the slides. Diagnoses were compared with histopathology. Sensitivity of the clinical assessments was 0.78 vs. 0.69 ("experts" vs. "non-experts"), sensitivity of dermatoscopy assessment was 0.83 vs. 0.69 (p = 0.04). The expert group demonstrated increased specificity (from 0.89 to 0.94) when applying dermatoscopy compared with clinical assessment alone (p=0.03). Positive likelihood ratios were doubled in the "expert group" and the negative likelihood ratios improved 25% with dermatoscopy compared with clinical assessment.

Data Interpretation, Statistical↗

Gene rearrangement in positive patch tests.

Lymphoproliferative disorders are usually characterized by lymphoid infiltrates that demonstrate clonality in contrast to inflammatory or reactive infiltrates of the skin that are polyclonal without detectable monoclonal populations of T-cells. Probably the southern blot analysis of TCR gene rearrangement can help to delineate the reactive from the malignant processes. In this study, we applied the technique on benign reactive processes in the skin. We examined biopsies from positive patch tests from patients with a delayed hypersensitivity reaction. We found the same gene rearrangement configuration in 11 of 17 patients with positive patch tests. The extra band revealed in these cases was situated in the EcoR1 digested DNA lane at the 8.0 Kb, between the 2 germline bands at the 11 Kb and the 4 Kb respectively. This observation was not correlated to the degree of the inflammatory response or to the specific hapten induced reaction. This pattern was not found in any of 107 patients with malignant diagnoses, but also in six of 43 patients with benign diseases. The clinical implication may suggest the presence or development of clonality in benign inflammatory disorders.

Biopsy↗

Treponema pallidum in leukoderma syphiliticum demonstrated by electron microscopy.

Punch biopsies from syphilitic leukoderma lesions and from unaffected skin in 3 patients with secondary syphilis were studies in the transmission electron microscope. In one of the patients the pigment disorder was not preceded by any visible syphilids, and in the biopsy from the leukodermal skin in this patient Treponemata pallidium were demonstrated around vessels and inside nerve fibres in which the myelin sheaths of the axons showed evidence of degeneration. In the other 2 patients the depigmented areas appeared while macular and papular syphilitic lesions were healing. In the biopsies from the leukodermal lesions of these 2 patients and from unaffected skin of all 3 patients, no treponemes were demonstrated. The study indicates that syphilitic leukoderma is not invariably a post-inflammatory phenomenon, but the pigmented skin lesions may themselves represent stigmata of an active syphilitic infection.

Adult↗

Ultrastructural changes of Treponema pallidum isolated from secondary syphilitic skin lesions.

Treponema pallidum was isolated from various types of secondary syphilitic skin lesions. From moist genital papules and from condylomata lata several treponemes were isolated whereas few were isolated from dry papules of the trunk. One third of the observed treponemes were morphologically different from treponemes isolated from human chancres. Especially the nose-piece structures of the terminal parts of the treponemes were deviating. Some nose-pieces were coated by a fuzzily outlined electron dense substance, whereas others were degenerated or nearly separated from the cytoplasmic body. Other treponemes were missing their nose-piece as avirulent saprophytic treponemes. Recent studies have indicated that the nose-pieces are essential for the tissue attachment of treponemes and the treponemal virulence. The significance of the altered nose-piece structure observed is discussed.

Adult↗

Recurrent genital herpes on the buttocks: "herpes disciformis".

We report a clinical variety of recurrent genital herpes on the buttocks of seven women ranging in age from thirty-four to eighty-one years. The lesions had recurred for one to nine years and had produced a characteristic cicatricial rounded area within the S2 to S3 dermatomes on one buttock. Herpes disciformis is believed to be an anatomical variant of the common genital herpes infection. We have only noted it in middle-aged or older women with no history of genital herpes.

Adult↗

Penicillin concentrations in serum following weekly injections of benzathine penicillin G.

Twelve patients with syphilis were treated weekly with injections of 1.44 g (2.4 X 10(6) IU) of benzathine penicillin G for up to 3 weeks. Almost daily, serum penicillin concentrations were measured by a sensitive microbiological agar cup method. An individual and interindividual variation was found. Concentrations below the recommended 0.018 micrograms/ml were found 7 days after the first or second injection in 5 samples. Shorter intervals between injections are recommended.

Absorption↗

Treponema pallidum in macular and papular secondary syphilitic skin eruptions.

The ultrastructure of biopsies from dry macular and papular secondary syphilitic skin lesions of 10 patients were studied by electron microscopy. In all biopsies few diffusely distributed treponemes were observed. This may explain the difficulties in demonstrating treponemes by darkfield examination of tissue fluid from dry secondary syphilitic skin lesions. The outlines of treponemes were less distinct as compared to those of primary syphilis. The periplastic membranes were almost invariably absent and the cytoplasmic membranes appeared in close contact with an enclosing layer of irregularly demarcated, electron dense amorphous substance. This substance may be a manifestation of the immune reaction of the host cells to the treponemes. Degenerations were noted in both unmyelinated and myelinated nerve tissue. This accounts for the fact that skin lesions in secondary syphilis are usually without symptoms. Also in the vessel walls treponemes were demonstrated. The vascular endothelial cells were proliferating and the basement membranes were multilaminated and split.

Endothelium↗

Treponema pallidum in human chancre tissue: an electron microscopic survey.

In biopsies obtained from syphilitic chancres of varying ages in 10 patients, a total of 766 ultrathin sections of Treponema pallidum were studied by electron microscopy. The course and number of axial filaments observed reveal that one bunch of 3-4 filaments without interruption entwine the whole cytoplasmic body. In 9.2% of the sections a trilaminar or a fragmentary trilaminar periplastic membrane was observed outside the cytoplasmic membrane and the axial filaments. The occurrence of the periplastic membrane decreased with advancing ages of the chancres. A protective function of the membrane is discussed. A peritreponemal fine reticular halo demonstrable in most fragments is supposed to be due to fixation induced shrinkage of treponemal hyaluronidase-influenced semifluid glycosaminoglycans. Peritreponemal reticular halos were also observed in collagen tissue. A destructive effect of the treponemes on collagen fibres could explain how the organisms penetrate through the collagen rich meninges into the central nervous system. A surface associated narrow border of electron dense amorphous substance, probably originating from the host organism, yields to tangentially cut treponemes a spiny caterpillar-like appearance.

Cell Membrane↗

The ultrastructure of treponema pallidum isolated from human chancres. Morphologic variations from Nichols' strain.

The ultrastructure of treponema pallidum obtained directly from human chancres by biopsy was studied by electron microscopy. The treponemes were enveloped by a trilaminar cytoplasmic membrane and a trilaminar periplastic membrane. The central part of the periplastic membrane corresponds to the protective mucoid layer. In undamaged organisms bunches of axial filaments were seen to entwine the whole cytoplasmic body without any disruption or overlapping. The number of axial filaments varied between three and four. Identical nose pieces were demonstrable in both ends of the treponemes. Axial filaments and nose pieces seem to differ from those of Nichols' strain.

Chancre↗

Pityriasis rosea eruption in secondary syphilis: an isomorphic phenomenon?

A 41-year-old man was referred because of a slightly pruritic eruption, and a classic case of pityriasis rosea was diagnosed on the first examination. Results of routine tests for syphilis were strongly positive, and on repeated examination the eruption had grown further. Skin biopsy specimens showed plasma cells and Treponema pallidum. All symptoms disappeared following antisyphilitic treatment. The possibility of an isomorphic response is discussed.

Adult↗

Antigen-free diet in adult patients with atopic dermatitis. A double-blind controlled study.

The efficacy of an antigen-free diet on the activity of atopic dermatitis was examined in a double-blind study, comprising 33 adults with severe atopic dermatitis. The antigen-free diet (Vivasorb) was compared to a placebo diet during three weeks of hospitalization. Twenty-five patients were evaluable, two of whom had their diet stopped after a few days due to exacerbation. Nine patients improved, while 16 patients were unchanged. Among those who improved five patients had Vivasorb and four placebo diet. In the remaining group 11 patients had Vivasorb and five had placebo. Four patients reported of less pruritus, sleeplessness and antihistamine consumption (three Vivasorb, one placebo) while 21 did not (13 Vivasorb, eight placebo). Thus, there were no significant differences between the groups. Paraclinical studies of circulating eosinophilocytes, serum IgE, orosomucoid, HLA-antigens, and immunofluorescence of skin biopsies showed no differences between the Vivasorb and the placebo groups. The results from the examination of this relatively small number of patients suggest that elementary intolerance plays little role in the etiology of atopic dermatitis in adults.

Adolescent↗

Pseudo-Kaposi sarcoma of the feet: an electron microscopic investigation.

A case of pseudo-Kaposi sarcoma of the feet (acroangiodermatitis) is reported. The patient showed clinical and light-microscopic signs closely resembling Kaposi's sarcoma, but by electron microscopy of skin biopsies definite signs of degeneration of vascular walls and infiltrating cells were demonstrated. Electron microscopy should be applied when conventional histology is inconclusive or fits poorly to the anamnestic information and/or clinical appearance of the lesions.

Acrodermatitis↗

Treponema pallidum in peripheral nerve tissue of syphilitic chancres.

Biopsies for electron microscopy were obtained from syphilitic chancres of 7 patients, 6 males and one female. In 4 of the patients, Treponemata pallida were seen gathering around peripheral nerves and invading the spaces between Schwann cells and their basal lamina. No definite degenerative changes were seen in the axons. In all patients, Treponemata pallida were gathering around the small blood vessels. The fine structure of Treponema pallidum in the lesions included a twined cytoplasmic cylinder with an inner and an outer lamina, an axial fibril consisting of three to five parallel filaments, each consisting of six microtubules, and a covering, outpouching periplastic membrane.

Adult↗