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Biomedical subjects

D Bang

Publications and source records attributed to D Bang.

At least 55 records · Page 3Linked to original sources
PubMed1991

Absence of lupus anticoagulants in Behçet's disease.

The presence of a lupus anticoagulant was evaluated in patients with Bechet's disease by the kaolin clotting time method. Four percents (three patients) of 69 patients analyzed were found positive for the lupus anticoagulant. However, no statistically significant association existed between the presence of this antibody and the presence of thrombosis, clinical activity, clinical type, antinuclear antibodies and the positive VDRL test.

Behcet Syndrome↗
PubMed1990

Effects of recombinant human granulocyte colony stimulating factor and granulocyte-monocyte colony stimulating factor on in vitro hemopoiesis in the myelodysplastic syndromes.

We evaluated the effects of recombinant human granulocyte colony stimulating factor (rhG-CSF) and granulocyte-monocyte colony stimulating factor (rhGM-CSF) on the in vitro proliferative, differentiative, and regenerative responsiveness of marrow cells from myelodysplastic syndrome patients (MDS) in comparison to those from normal individuals. Our studies showed decreased primary clonogenicity of myeloid (CFU-GM) and erythroid (BFU-E) hemopoietic progenitor cells from the MDS patients. rhGM-CSF had more potent stimulatory effects than rhG-CSF for MDS marrow CFU-GM growth; no enhanced cellular proliferation in the MDS patients was observed in liquid culture with either rhGM-CSF or rhG-CSF. Decreased myeloid clonal cell self-generation and/or recruitment occurred in the MDS patients upon exposure to either rhG-CSF or rhGM-CSF. rhG-CSF demonstrated more potent granulocytic differentiation effects than rhGM-CSF both for normals and MDS patients using marrow enriched for immature myeloid cells with lesser differentiation noted for MDS. Cytogenetic abnormalities, present with or without additional normal karyotypes in native marrow of four MDS patients, persisted after culture with rhG-CSF, indicating induced differentiation of both normal and abnormal clones. Although proliferative and differentiative effects were seen with both factors these data show MDS marrow cells in vitro to have predominantly differentiative responsiveness to rhG-CSF and proliferative responsiveness to rhGM-CSF.

Adult↗
PubMed1989

Scanning electron microscopy of Malassezia furfur in tinea versicolor.

Morphologic features of Malassezia(M.) furfur in the horny layer from clinical lesions of tinea versicolor were examined by scanning electron microscopy and compared with the appearance of fungus in the horny layer from normal skin and in culture. In skin lesions of tinea versicolor, M. furfur showed a variety of growth and reproduction patterns. Although the main patterns were budding yeast forms, various patterns suggesting yeast-mycelial conversion were observed and mycelial hyphae were more prominent in the deeper horny layer than in the superficial layers. However, in the skin of normal persons and in culture, M. furfur existed only as yeast forms and no mycelial hyphae or yeast-mycelial conversion forms were seen. This suggests that the morphologic change of M. furfur, from a yeast form to a mycelial hypha one, may play a role in the induction of the clinical lesion of tinea versicolor.

Biopsy↗
PubMed1989

Pilar sheath acanthoma--report of a case with review of the literature.

A 52-year-old male presented with a solitary asymptomatic, skin-colored nodule with a central pore on the skin of the left cheek of one year duration. An excisional biopsy was performed. The skin biopsy finding showed the typical histological picture of pilar sheath acanthoma. A description of the lesion and a review of the literature are given.

Diagnosis, Differential↗
PubMed1989

Assessment of apoptosis of infiltrating lymphocytes in erythema nodosum-like lesions of corticosteroid-treated patients with Behçet's syndrome.

Biopsy specimens of recurrent erythema nodosum-like lesions from corticosteroid-treated and non-treated patients with Behçet's syndrome were examined with the electron microscope to determine the incidence of apoptotic cell death of infiltrating lymphocytes in connective tissue. Apoptosis of infiltrating lymphocytes was detected in all corticosteroid-treated patients, but not in non-treated patients. While part of this phenomenon is undoubtedly due to a direct action of corticosteroids on the lymphocytes themselves, it seems likely that indirect action of the corticosteroids such as inhibition of lymphokine or interleukin production may deprive lymphocytes of proliferative and other stimuli and therefore also play some part in the overall response.

Adrenal Cortex Hormones↗
PubMed1988

Appearance of membranocystic lesion (Nasu)-like changes in Behçet's syndrome. An electron microscopic study of erythema nodosum-like lesions.

Membranocystic lesion (Nasu)-like changes were seen in the subcutaneous fat tissues of erythema nodosum-like lesions in three of 18 patients with Behçet's syndrome. The membranocystic structures, which were derived from degenerative fat cells with a loss of the cell membrane, were observed in the edematous connective tissues accompanied by fibrin deposition and diapedesis of erythrocytes. Electron microscopic evaluation revealed two different patterns of peculiar membranous structures in the cytoplasm of the degenerative fat cells. One was proliferating membrane structures such as well developed Golgi-endoplasmic reticulum, and the other was minute tubular structures such as intracytoplasmic microvesicles. These degenerative fat cells are considered to be derived from abnormal fat cells which lack a cell membrane, but whose cellular and nuclear configurations appear to be normal morphologically, because the cytoplasm of these abnormal cells showed the same tubular structures as those seen in the characteristic architecture of membranocystic lesion-like change. The relation between the appearance of such abnormal cells and the pathologic conditions of erythema nodosum-like lesions in Behçet's syndrome was discussed.

Adipose Tissue↗
PubMed1988

Ultrastructure of vascular changes in cutaneous manifestations of Behçet's disease.

We observed small dermal blood vessels embolized by thrombus at the sites of needle-prick reaction as well as erythema nodosum-like lesions in 4 patients with Behçet's disease, by means of electron microscopy. The ultrastructural finding associated with overproductive proliferation of the endothelial cells leading to obliteration of the vascular lumen was the sporadical appearance of degenerated cells among proliferating endothelial cells in both cutaneous manifestations. These degenerated cells showed contraction changes and may be involved in thrombogenesis.

Behcet Syndrome↗
PubMed1988

Topical application of cyclosporine on guinea pig allergic contact dermatitis.

Topical cyclosporine applied to the test site substantially inhibited the elicitation reaction of contact sensitivity in the guinea pigs previously sensitized with 2,4-dinitrochlorobenzene (DNCB). This suppressive effect of the drug was short lived and reversible. Cyclosporine was not effective when given six hours or later after antigenic challenge to the test site. Cyclosporine had no effect on the toxic contact reaction in normal animals either to croton oil or to DNCB in high concentration. Cyclosporine applied topically to the challenge site also resulted in a reduction of retest and flare-up reactions of contact sensitivity to DNCB, but did not affect the production of generalized rash in the same animals. These results indicate that in the future local topical application of cyclosporine may make treatment of human cutaneous immune-mediated disorders a possibility without serious side effects.

Administration, Topical↗
PubMed1987

Delayed-type skin reaction to 2,4-dinitrophenylated epidermal cells in guinea pigs with contact sensitivity to 2,4-dinitrochlorobenzene.

Contact sensitivity (CS) induced by hapten has been thought to be analogous to delayed-type hypersensitivity, such as the Mantoux reaction, because of outstanding similarities between the two phenomena. It can be suggested that animals with CS respond also to intradermal injection of the conjugate of hapten and protein as well as to epicutaneous application of hapten. However, evidence against this has been reported. In the present experiments, delayed-type skin reaction (DSR) was successfully obtained in JY1 strain guinea pigs sensitized by painting the skin with 2,4-dinitrochlorobenzene using in vitro dinitrophenylated epidermal cell suspension (DNP-EC) as antigen for a delayed intradermal test. The experiment using anti-Ia alloantiserum and complement showed that the elicitation of DSR is due to the presence of Ia-positive cells (presumably Langerhans cells) among DNP-ECs. The delayed intradermal test with the conjugates such as haptenated ECs in the animals with CS is considered to be an experimentally useful way of analysing the antigen in the sensitivity.

Administration, Topical↗
PubMed1987

Histological study on the fate of haptenated epidermal cells injected intradermally in guinea pigs.

The percutaneous administration of in vitro haptenated epidermal cells (EC) has become established as a procedure to produce contact sensitivity (CS) in experimental animals for routine use. The cells have also been found to elicit a significant delayed-type skin reaction by intradermal test in the animals sensitized by painting the skin with the hapten. The fate of 2,4-dinitrophenylated (DNP) isogeneic epidermal cell suspensions (EC) injected intradermally was investigated histologically in intact or 2,4-dinitrochlorobenzene (DNCB)-sensitized strain 13 guinea pigs to study the role of the cells in CS. DNP-EC were found to proliferate actively in the dermis and formed EC nests with central keratinization and then elicited inflammatory reaction associated with necrosis of the epidermal structures 7 days after injection in the intact animals. DNP-EC injected intradermally into the animals which had received and reacted against DNCB underwent a suppression of EC proliferation. These findings are discussed in relation to the role of the haptenated EC in CS.

Animals↗
PubMed1987

The pathogenesis of vascular changes in erythema nodosum-like lesions of Behçet's syndrome: an electron microscopic study.

The probable sequence of microvascular changes affecting endothelial cells in erythema nodosum-like lesions was examined by electron microscopy in 18 patients with typical Behçet's syndrome. Dark endothelial cells in the superficial and deep dermis exhibited degeneration with contraction changes. Consequently, degenerated endothelial cells showed nuclear and cytoplasmic condensation, vacuolization in the cytoplasm, and rich ribosomes. Moreover, blood vessels which were enveloped by cuffs of lymphocytes simultaneously exhibited both endothelial cell hypertrophy and endothelial cell necrosis. The implied associations between perivascular lymphocytic cuffs and blood vessels exhibiting endothelial cell alterations indicate that microvascular changes in erythema nodosum-like lesions may be closely associated with the delayed-type hypersensitivity reaction.

Behcet Syndrome↗