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Biomedical subjects

C U Brand

Publications and source records attributed to C U Brand.

51 records · Page 3Linked to original sources
PubMed1996

Investigation of skin-derived lymph: an approach to get insight into the skin immune system.

The skin acts as a mechanical, physicochemical and immunological control and defense system, and its lymphatic vessels play a role in the regulation of cell hydration and osmosis, as well as in immunological responses. Skin-derived signals, produced in response to various agents acting on the skin, arrive with the afferent lymph at the regional lymph nodes. These signals reflect the immunological processes in the skin and may also determine the reactions in the lymph node. By analyzing afferent lymph derived from specific skin lesions it should therefore be possible to get insight into local pathomechanisms as well as the signal transmission in skin disorders. In this report, we present methodological aspects of such skin-derived lymph studies and review the results obtained from studies of sodium-lauryl-sulfate-induced irritative contact dermatitis in humans.

Cytokines↗
PubMed1996

Combined surgical and X-ray treatment for angiosarcoma of the scalp: report of a case with a favourable outcome.

Classic angiosarcoma is an uncommon malignant neoplasm of vascular differentiation which is highly aggressive. The diagnosis is often delayed and, since the response to treatment mainly depends on the size of the tumour, the prognosis is usually poor. Here we report a 76-year-old man in whom an extensive angiosarcoma of the scalp was treated by excision followed by wide-field radiotherapy. More than 4 years later there are no signs of local recurrence or of metastasis.

Aged↗
PubMed1995

[Lymphocyte stimulation test, a possible alternative for verifying chloroacetophenone sensitization].

We report on a case of pronounced sensitization to chloroacetophenone tear gas that developed after repeated occupational skin exposure in a 57-year-old police officer. Mainly in the presence of moisture and occlusion, cutaneous application of chloroacetophenone leads to severe irritant, and often also allergic, skin reactions. In patch testing the demonstration of allergic contact dermatitis in response to chloroacetophenone is hampered by the irritative potential of this substance even at low concentrations. This diagnostic bias can be overcome by the lymphocyte proliferation assay.

Dermatitis, Occupational↗
PubMed1995

Activated immunocompetent cells in human skin lymph derived from irritant contact dermatitis: an immunomorphological study.

By means of microsurgical lymph cannulation, skin lymph was sampled in the course of a sodium lauryl sulphate (SLS)-induced irritant contact dermatitis in human volunteers. The lymph cells were isolated by centrifugation, and then characterized immunocytochemically using different monoclonal antibodies, and in the late phase of the skin reaction also by electron microscopy. Analyses of lymph cells before the induction of the contact dermatitis revealed median values of about 60% T cells (CD4/CD8 ratio about 2:1), 4% Langerhans cells (LCs), and 1% B cells. The remainder were varying proportions of erythrocytes and uncharacterized cells. During the skin reaction, and even after resolution of the clinical signs of dermatitis, a relative and absolute increase of T and B cells, as well as of HLA-DR positive cells, paralleled the previously reported increased of LCs; a high percentage of the T cells were CD4 and CD8 negative. In addition, surface markers such as CD11a, CD25, CD54 and CD58 were detected on lymph cells sampled during the irritant skin reaction. Cell rosettes observed in the lymph throughout the experiment were analysed in the late phase of the skin reaction, and showed a central LC with three to five peripheral, in part activated, T cells, ultrastructurally revealing gap junction-like structures between the two cell types. These data indicate that immunocompetent cells in the skin are activated by a variety of non-immunological stimuli such as operative trauma and irritant contact dermatitis.

Adult↗
PubMed1994

Complement profiles in human skin lymph during the course of irritant contact dermatitis.

Using microsurgery a superficial peripheral lymph vessel draining the skin of the upper and medial part of the foot was cannulated on the lower leg of two healthy human volunteers. An irritant contact dermatitis was induced 2 days later by the application of 10% sodium lauryl sulphate to the drained skin area. After a further 3 days the spontaneously regressing skin reaction was treated with clobetasol propionate. Lymph was continuously collected in two aliquots per day for 7 days. The levels of total protein, of albumin and globulins, and of complement components of the classical, the alternative and the lytic pathway as well as the C4A and C4B gene products and the regulatory proteins FB, C1INH, C4BP, FH and FI were determined by ELISA and radial immunodiffusion techniques. Postoperatively, the levels of complement proteins and globulins in the lymph were 5-10 times lower than those in normal human serum, but increased during the course of the skin reaction, while the irritant contact dermatitis did not induce a change in their plasma concentration. In comparison to the baseline, the mean values for C1q, C1r, C2, C5, C6, C7, C8, C9, FB, C1INH, C4BP, FH and FI exhibited a 3-5-fold increase, C3, total C4, albumin and the alpha 1-globulin fraction a 6-9-fold increase, and C1s, C4A, C4B, FB and alpha 2-, beta- and gamma-globulins a 10-20-fold increase.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1994

Reduced number of Langerhans cells in oral mucosal washings from HIV-1 seropositives.

In order to elucidate mucosal immunity in HIV-1 seropositive individuals, we investigated oral mucosa washings from 20 HIV-1 seropositive patients for the presence of Langerhans cells (LC) and HIV-1 antigen-positive cells, and compared the results with those obtained from 20 HIV-1 seronegative healthy individuals. Monoclonal antibodies directed against CD1a, HLA-DR, CD3, and p24 were used to identify LC, T cells and HIV-1 core-antigens, respectively. In oral mucosa washings from HIV-1 seropositive patients there was a significant reduction in the number of CD1a+ cells as compared with the healthy subjects. HIV-1 antigen-positive cells were not detected. The reduction of LC in oral mucosa washings from HIV-1 seropositive patients is probably associated with HIV-1 infection. The frequent occurrence of oral mucosal disorders in HIV-1 infected patients may in part be caused by a reduced LC-number and/or function.

AIDS-Related Opportunistic Infections↗
PubMed1993

Large increase of Langerhans cells in human skin lymph derived from irritant contact dermatitis.

In order to monitor the kinetics of Langerhans cells in the afferent lymph during contact dermatitis, a superficial peripheral lymph vessel draining the skin of the upper and medial part of the foot was cannulated by means of microsurgery on the lower leg of four healthy volunteers. After 2 days an irritant contact dermatitis was induced by application of 10% sodium lauryl sulphate to the area of skin drained by the cannulated lymph vessel. Three days later the spontaneously regressing skin reaction was treated with clobetasol propionate in two of the subjects. Lymph was collected twice daily for 8 days. Langerhans cells were identified by immunofluorescence microscopy of cytocentrifuge slide preparations from the lymph, using a monoclonal anti-CD1a antibody. In the late phase of the contact dermatitis the output, i.e. both the absolute number and the percentage of Langerhans cells in the lymph dramatically increased. At the end of the experiment, when there were no remaining clinical signs of contact dermatitis, the Langerhans cell output still markedly exceeded the initial values. These results are the first direct evidence in humans that migration of Langerhans cells from the skin to the regional lymph nodes is a major feature of irritant contact dermatitis.

Adult↗
PubMed1993

Phenotype of Langerhans cells in human afferent skin lymph derived from allergic contact dermatitis.

By means of microsurgical lymph cannulation human skin lymph derived from the late phase of an elicitation reaction to diphenylcyclopropenone was sampled. Cells were isolated by centrifugation and then treated with mouse anti-CD1a monoclonal antibodies and sheep antimouse antibody-coated Dynabeads. Ultrastructural and immunocytochemical analyses revealed anti-CD1a/Dynabead-rosetted CD1a- and protein S-100-positive cells which did not express monocyte surface markers, but surface antigens such as HLA-DR, ICAM-1 and, in part, LFA-3. In comparison to freshly prepared human epidermal Langerhans cells (LC), a large fraction of these cells contained no or markedly fewer Birbeck granules and exhibited extensive ruffling of the surface. These data suggest that the phenotype of LC in skin lymph derived from the elicitation phase of allergic contact dermatitis is similar to LC cultured in vitro. In the functional concept of LC of our time, these cells correspond to the dendritic cells designated as "veiled".

Adult↗
PubMed1992

Isolation of human skin-derived lymph: flow and output of cells following sodium lauryl sulphate-induced contact dermatitis.

By means of microsurgery a peripheral subcutaneous lymph vessel draining a defined skin area was isolated and cannulated on the lower leg of six healthy volunteers. Lymph was collected over a period of 8 days. During the first 2 days baseline values for lymph flow and output of cells were established. A contact dermatitis was then induced in the drained skin area by the application of 10% sodium lauryl sulphate. All six probands developed a mild to moderate irritant contact dermatitis. Lymph flow as well as output of cells increased with the intensity of the skin reaction. Subsequent local treatment with clobetasol propionate decreased the cell output, but the lymph flow increased further. Neither lymph flow nor output of cells returned to the initial baseline values at the end of the study, when the clinical signs of contact dermatitis had completely disappeared. During the experiment significant individual variations were found, with means ranging from 0.10 to 0.48 ml/h for lymph flow and from 8700 to 174000/h for cells, which probably depended mainly on the different topographies and calibres of the cannulated lymph vessels.

Adult↗
PubMed1992

Studies on human skin lymph containing Langerhans cells from sodium lauryl sulphate contact dermatitis.

Immunologic processes in diseased human skin have been extensively investigated, but little is known about the effect of skin diseases on human afferent skin lymph. Starting in the papillary dermis, the skin lymphatics drain the adjacent tissue in a one-way flow toward the regional lymph nodes. The composition of the afferent lymph, therefore, reflects the immunologic inflammatory processes in the drained tissue. To obtain afferent lymph to investigate its content, we inserted a cannula, by means of microsurgery, into a superficial peripheral lymph vessel draining a defined skin area. By manipulating the drained skin area and subsequent examination of the lymph we established an in vivo system for investigating the kinetics of lymph changes during the course of skin reactions. In lymph derived from a mild sodium lauryl sulphate (SLS)--induced contact dermatitis we could demonstrate an increase of both flow and cells. In particular, the number of Langerhans cells (LC) increased enormously during the course of the skin reaction. It, therefore, seems that a large increase in the migration of LC from the skin to the regional lymph nodes is a major feature of SLS-induced contact dermatitis, suggesting that LC may play a major role in the irritant contact dermatitis reaction.

Cell Count↗
PubMed1992

Increased levels of inflammatory cytokines in human skin lymph derived from sodium lauryl sulphate-induced contact dermatitis.

A superficial peripheral lymph vessel draining the skin of the upper and medial part of the foot was cannulated on the lower leg of six healthy human volunteers. After 2 days an irritant contact dermatitis was induced by application of 10% sodium lauryl sulphate to the area of skin drained by the lymph vessel. Three days later the spontaneously regressing skin reaction was treated with clobetasol propionate. Lymph was collected twice daily for 7 days, and the levels of various cytokines (IL-1 alpha, IL-1 beta, IL-2 and soluble IL-2 receptors, IL-6, IL-8, TNF-alpha, GM-CSF) were determined by ELISA technique. In the majority of the volunteers all cytokines examined were detected in several lymph samples, with the exception of IL-1 alpha and IL-8. In parallel with the clinical symptoms of the contact dermatitis the levels of IL-6 and TNF-alpha increased 8-10-fold, whereas for IL-1 beta, IL-2, IL-2 receptors, and GM-CSF there was a delayed, 2-3-fold increase. These results suggest that cytokines, in particular IL-6 and TNF-alpha, may actively participate in the immunological reactions in the skin and in the regional lymph nodes during contact dermatitis.

Cytokines↗
PubMedDate not supplied

Characterization of human skin-derived CD1a-positive lymph cells.

The phenotype and function of CD1a+ lymph cells is of considerable interest. By means of microsurgical lymph cannulation human lymph derived from normal skin was sampled. Cells were isolated and processed for immunocytochemistry, electron microscopy, flow cytometry and functional assays. The majority of the cells, (62%), were T cells. The other cells comprised CD1a+ cells (7%), monocytes/macrophages (8%), and B cells (1%); the remainder were erythrocytes or uncharacterized cells. The CD1a+ cells reacted with antibodies against protein S-100, HLA-DR, the Lag antigen, CD4, CD11a, CD11b, CD18, CD25, CD40, CD54, CD80 and CD86. Interestingly, a small prolow portion the of CD1a+ cells (about 5%) reacted with an antibody to CD14. The CD1a+ cells did not react with an antibody against human follicular dendritic cells nor were they CD19-, CD23-, E-cadherin- or factor XIIIa-positive. Both allogenic and antigen-specific T cell proliferation stimulated by antigen-presenting lymph cells were strongly inhibited by adding anti-CD80 and anti-CD86 antibodies. By electron microscopy Birbeck granules were detected in only 22% of the CD1a+ lymph cells and these cells exhibited an extensive ruffling of the surface. These findings demonstrate that CD1a+ lymph cells, which do not express the dermal dendritic cell marker factor XIIIa, resemble dendritic cells formerly designated as 'veiled' as well as lymphoid dendritic cells, suggesting that after migration to the regional lymphoid organs, Langerhans cells form a more differentiated population of dendritic cells specialized in sensitizing T lymphocytes. Our results add further support to the view that resident Langerhans cells may be precursors of lymphoid dendritic cells acquiring the final phenotype in the microenvironment of the lymph node.

Adult↗