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Biomedical subjects

T Kaaman

Publications and source records attributed to T Kaaman.

33 records · Page 2Linked to original sources
PubMed1984

Brittle hair in osteogenesis imperfecta: transmission and scanning electron microscopy and mycologic assay.

The brittle hair fibres from a case of osteogenesis imperfecta were studied by scanning and transmission electron microscopy. Normal hair fibres are extremely difficult to infect with T. mentagrophytes. As a tentative assay for biochemical defects of hair fibres, experimental dermatophytic infection of the hair with T. mentagrophytes was performed. The massive growth induced suggested that the experimental fungal infection may indeed indicate a biochemical defect in the hairs from our case of osteogenesis imperfecta.

Adult↗
PubMed1983

Human epidermal Langerhans cells induce cellular immune response to trichophytin in dermatophytosis.

Human epidermal cell suspensions were prepared from patients sensitized to trichophytin. The cells were 75% to 95% viable, and contained 2% to 6% Langerhans cells as judged by immunofluorescence staining with an anti-DR antiserum. T lymphocytes from the same patients were co-cultured with trichophytin, with or without epidermal cells or macrophages. Proliferative T-cell response to trichophytin was obtained in cultures containing epidermal cells or macrophages. Pretreatment of the epidermal cells with anti-DR antiserum abolished the response, but normal rabbit serum did not, indicating that HLA-DR positive Langerhans cells are able to induce the cellular immune response to trichophytin. These data indicate that Langerhans cells play an important role in dermatophytosis.

Dermatomycoses↗
PubMed1983

Dermatophytid--a misdiagnosed entity?

A mycological and immunological survey was performed in 26 patients with clinical signs of dermatophytid. Only 10 patients fulfilled the main criteria of dermatophytid reactions, i.e. positive delayed skin test to trichophytin and dermatophyte isolated by culture. Trichophyton mentagrophytes--especially the zoophilic variant--was found in 9 patients of 10. In the majority of cases, inflammatory tinea pedis caused the dermatophytid reaction which appeared as vesicles localized to the palms. Relying on clinical appearance only implies an obvious risk of erroneously including pyoderma and various eczemas, e.g. pompholyx and contact dermatitis, as dermatophytids. Mycological culture and skin test with a reliable trichophytin antigen preparation ought to be applied in order to avoid misdiagnosis.

Dermatomycoses↗
PubMed1982

Leukoderma syphiliticum: ultrastructural observations on melanocyte function.

A case of genital leukoderma syphiliticum was analysed submicroscopically. No treponema pallidum organisms could be detected intra- or extracellularly in the epidermis or in the dermis. The melanocytes were only slightly reduced in number and had mostly normal outlines. The melanogenesis was impaired and small melanosomes with decreased deposition of melanin were mostly produced at the expense of normal melanin granules. A partial block in the melanin transfer mechanism seems to be in evidence. As no direct destructive action of spirochetes on the melanocytes is observed, an indirect effect is assumed, e.g. by a tyrosinase inhibitor.

Adult↗
PubMed1982

The changing clinical picture of Microsporum canis infections in Sweden.

All 22 cases of infections with Microsporum canis verified by culture during a five-year period were surveyed. Only tinea corporis was found. The clinical picture was varied and in more than half of the cases the preliminary diagnosis was other than tinea. The classical tinea capitis was not found in any case. Direct KOH-mounts showed poor correlation to the cultural findings (positive in 33%). It is concluded that mycological screening of certain dermatological disorders should be performed by culturing.

Adolescent↗
PubMed1981

T-lymphocyte subpopulations in patients with chronic dermatophytosis.

T lymphocytes with Fc receptors for IgM (Tm cells) or IgG (Tg cells), known under certain conditions to exert help or suppression, and T-helper and T-suppressor cells, defined by fluorescein-isothiocyanate-conjugated monoclonal antibodies, were determined in 7 patients with chronic dermatophytosis. There appeared to be a relation between severity of the disease and decreased proportion of Tm cells with concomitant increase of Tg cells. However, only in 1 severe case there was also a shift of T-helper and T-suppressor cells as defined by monoclonal antibodies.

Adult↗
PubMed1981

Cell-mediated reactivity in dermatophytosis: differences in skin responses to purified trichophytin in tinea pedis and tinea cruris.

Cell-mediated immune responses were measured in 91 patients with dermatophytosis by means of delayed-type skin hypersensitivity to a purified trichophytin preparation (ethylene glycol method) and to tuberculin (purified protein derivative, PPD). The findings indicate that dermatophytes differ in their sensitizing capacity as measured by trichophytin skin sensitivity. Trichophyton mentagrophytes appeared to be a potent sensitizer compared with Trichophyton rubrum (p < 0.01), whereas Epidermophyton floccosum appeared as a moderate sensitizer. The localization of infection also affected the cell-mediated response to trichophytin, i.e. the frequency of reactions was 44% in tinea cruris and 33% in tinea pedis, while tinea pedis with nail infections elicited delayed-type reactivity in 60% of cases. On the basis of the significant difference (p < 0.001) in cell-mediated reactivity between chronically and non-chronically infected subjects as measured with trichophytin, it is concluded that the cell-mediated response is of importance for the development of host resistance to dermatophytic infections. This study provides further evidenced in support of the view that a partial defect in the cell-mediated system may be responsible for establishment of chronic dermatophytosis.

Adult↗
PubMed1981

Cell mediated cross-reactivity in vivo and in vitro to purified dermatophyte antigen preparations in sensitized guinea pigs.

Guinea pigs were sensitized to either Trichophyton rubrum, Trichophyton mentagrophytes, or Epidermophyton floccosum. Cross-reactivity experiments were performed in vivo and in vitro with purified antigen preparations prepared from the respective dermatophyte according to the ethylene glycol method. All sensitized animals responded with delayed-type skin reactions to all three antigen preparations, although the strongest reactivity observed was to the homologous antigen. Spleen and blood lymphocytes from many (but not all) animals were stimulated by these antigens and the response to the homologous antigen was always more pronounced. The findings indicate the presence of a common group-specific dermatophyte antigen as well as the possibility of species-specific antigens in the experimental system studied.

Animals↗
PubMed1981

ELISA-determined serological reactivity against purified trichophytin in dermatophytosis.

Serological activity in 62 patients wih dermatophytosis was investigated using purified trichophytin preparation as antigen (produced by the ethylene glycol method). Antibodies of IgG and IgM classes were determined by means of ef enzyme linked immunosorbent assay (ELISA). In comparison with 79 controls consisting of groups of healthy blood donors and dermatological outpatients, the dermatophyte-infected patients showed a significantly higher mean IgG response to trichophytin antigen preparation. On the other hand several individual cases were low responders. In a group of 10 control children, no IgG activity against trichophytin could be demonstrated. IgM class antibodies showed no significant differences between the groups investigated. These findings indicate that differences in the amounts of antibodies of IgG class against trichophytin as measured by the ELISA method reflect differences in the degree of mycotic sensitization between groups of individuals having experienced varying degrees of exposure to dermatophytes. Nevertheless, the determination of IgG antibodies in dermatophytosis seems to be of limited clinical value.

Antibody Formation↗
PubMed1979

In vivo and in vitro immune responses to trichophytin in dermatophytosis.

Cell-mediated immunity in patients with verified dermatophytosis was investigated by means of skin test and lymphocyte stimulation test (LST) using purified trichophytin, prepared by the ethylene glycol method, and commercially available trichophytin. The purified trichophytin seemed to be more specific and sensitive both in skin test and in LST. In the majority of cases skin-positive patients were also positive in LST, especially when T. mentagrophytes or E. floccosum was the causative organism. Patients with non-chronic infections also showed a close correlation between skin reactivity and LST. Patients with chronic mycosis or infected with T. rubrum, on the other hand, were often skin-negative. Their lymphocyte reactivity in vitro, however, was usually positive, thus showing a discrepancy in the ability of these two methods to measure cell-mediated immunity.

Antigens↗
PubMed1978

The clinical significance of cutaneous reactions to trichophytin in dermatophytosis.

An intracutaneous test was performed in 114 patients with dermatophytosis verified by culture and in 32 control subjects, unsing purified trichophytin (according to the ethylene glycol method) and commercially available trichophytin. Immediate reactions occurred with both trichophytin antigens at a similar frequency in 12-14% of cases. Delayed reactions occurred significantly more often to the purified trichophytin in patients with dermatophytosis (36%) but in none of the controls. Immediate reactions to purified trichophytin occurred in 26% of the chronically infected patients. Delayed reactions were correlated to patients with tinea cruris (50% positive reactions), to infections with Epidermophyton floccosum (50%) and to patients not chronically infected. Thus, chronic dermatophytosis was characterized by immediate reactions to purified trichophytin and few delayed reactions. In contrast, patients not chronically infected were characterized by delayed reactions and few immediate reactions.

Antigens↗
PubMed1976

An evaluation of delayed hypersensitivity in guinea pigs to various trichophytin preparations.

Guinea pigs immunized with mycelium from Trichophyton mentagrophytes in Freund's complete adjuvant were tested intradermally with the following trichophytin preparations: TrI extracted by ethylene glycol, TrII extracted by phenol and TrII, a commercially obtained preparation fromSächsisches Serumverk KG. In our experience, TrI was found to be superior to the other preparations. It showed signifiicant delayed skin reactions in all sensitized animals and none in the controls. Lymphocyte stimulation test with this preparation (TrI) gave positive results.

Animals↗