Biomedical subjects
J D Bos
Publications and source records attributed to J D Bos.
Immunocompetent cells in psoriasis. In situ immunophenotyping by monoclonal antibodies.
Immunocompetent cells in exacerbating untreated psoriasis vulgaris skin lesions were immunophenotypically studied by the application of a selection of monoclonal antibodies in a two-stage immunoperoxidase technique. Epidermal changes include: focal accumulation of immunoglobulins in the stratum corneum, as demonstrated by a mixture of monoclonal anti-kappa and anti-lambda antibodies; focal accumulation of OKM-1 positive but Mo-2 negative cells high in the epidermis, reflecting granulocytes in Munro's abscesses; a marked decrease in epidermal Langerhans cells with focal abnormal clumping and smaller dendrites, as demonstrated by monoclonal anti-HLA-DR and anti-T6 (OKT-6) antibodies; and, sporadic exocytosis of mainly T1 (Leu-1), T8 (Leu-2a) positive suppressor/cytotoxic T lymphocytes. The dermal infiltrates were found to consist mainly of partically activated T1 (Leu-1), T4 (Leu-3a) positive T-helper/inducer cells with a smaller compartment of T1 (Leu-1), T8 (Leu-2a) positive suppressor/cytotoxic lymphocytes. These cells were found in close apposition to T6 (OKT-6), HLA-DR positive Langerhans cells and further accompanied by a minor compartment of OKM-1, Mo-2 positive monocytes. No B-cells or plasma cells could be demonstrated in the dermis. Natural killer cells were observed only incidentally. These results fit best with the hypothesis that psoriasis is a chronic inflammatory condition as a result of persistent stimulation of T cells by immunogen(s) of epidermal origin.
Trigeminal trophic syndrome: a successful treatment with transcutaneous electrical stimulation.
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Natural killer cells involved in lymphomatoid granulomatosis.
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Fluorescent treponemal antibody-absorption (FTA-ABS) test.
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Antitreponemal IgE in early syphilis.
Using a solid-phase radioimmunoassay technique, mean serum IgE concentrations were found to be raised in patients with early syphilis. Antitreponemal specificity of the IgE response was investigated by the fluorescent treponemal antibody absorption test using a fluorescein-isothiocyanate-labelled antiserum against the Fc-fragment of human IgE. Validity of this test procedure was assessed by blocking experiments. The results provide evidence of the antitreponemal specificity of the IgE response in syphilis and indicate a possible role for antitreponemal IgE in the pathogenesis of the Jarisch-Herxheimer reaction and in the immune-complex origin of some of the lesions of secondary syphilis.
Immunoglobulin-bearing lymphoid cells in primary syphilis. Quantitative and elution studies.
The delay in antibody production in response to infection with Treponema pallidum may be caused by a block in the differentiation of antigen-stimulated B (Bursa-dependent) lymphoid cells towards plasma cells. This hypothesis was tested by a study to detect clonal expansion of immunoglobulin-bearing B lymphoid cells by in-vitro immunofluorescence tests in patients with primary syphilis. In addition, antibodies eluted from circulating lymphoid cells were investigated for treponemal binding by the enzyme-linked immunosorbent assay, the T pallidum immobilisation test, and the immunoglobulin class-specific FTA-ABS test. Results indicated that the number of IgG-bearing lymphoid cells were increased in patients with primary syphilis. However, in only a few cases could antitreponemal antibodies be eluted from isolated lymphoid cells. For this reason, the original hypothesis was rejected.
T lymphoid cells in primary syphilis. Quantitative studies.
In previous studies to assess the role of cell-mediated immunity in Treponema pallidum infection investigations of delayed type skin hypersensitivity tests, lymphocyte transformation test, leucocyte migration inhibition tests, and histological studies of the reticuloendothelial system have been performed. In this study, the numbers of T (thymus-dependent ) lymphoid cells in 10 patients with primary syphilis (eight untreated) were estimated by the rosette technique. Results indicate a significant decrease in the number of T lymphoid cells in patients with primary syphilis.
Immunoglobulin-bearing polymorphonuclear leucocytes in primary syphilis.
Non-specific defence mechanisms are thought to be ineffective in eliminating Treponema pallidum after infection in the early stages, but studies aimed at the elucidation of this phenomenon are few. In this study, the number of IgG-bearing polymorphonuclear leucocytes in patients with primary syphilis was increased; this is most probably a normal phenomenon of infection.
Cultured fibroblasts from chronic diabetic wounds on the lower extremity (non-insulin-dependent diabetes mellitus) show disturbed proliferation.
Patients with diabetes mellitus experience impaired wound healing often resulting in chronic foot ulcers. Hospital discharge data indicate that 6-20% of all diabetic individuals hospitalized (mostly with type 2 diabetes) have a lower extremity ulcer. Maintaining glucose levels at acceptable levels (below 10 mmol/l) is considered to be an important part of the clinical treatment, but the exact mechanism by which diabetes delays wound repair is not yet known. We studied this phenomenon by determining the potential of fibroblasts isolated from the ulcer sites of four patients with non-insulin-dependent diabetes mellitus to proliferate in vitro. Controls were fibroblasts isolated from normal skin of the upper leg of five healthy age-matched volunteers and of six non-insulin-dependent diabetes patients. Proliferative capacity was analysed by evaluation of plates after trypsinization and [3H]thymidine incorporation. Fibroblast morphology was studied by light and transmission electron microscopy. Diabetic ulcer fibroblasts, measured by [3H]thymidine incorporation, proliferated significantly more slowly than the nonlesional control fibroblasts (P < 0.00047) and age-matched control fibroblasts (P < 0.00003). After culturing the fibroblasts for a prolonged period in high-glucose (27.5 mM) and low-glucose (5.5 mM, i.e. physiological) medium, this difference in proliferation rate between diabetic ulcer fibroblasts and nonlesional diabetic fibroblasts remained (P < 0.0001 for high-glucose and P < 0.0009 for low-glucose on day 7). Fibroblast proliferation in all three groups was slightly lower in high-glucose than in low-glucose medium, although not significantly at any time-point. Light microscopy showed diabetic ulcer fibroblasts to be large and widely spread. Transmission electron microscopy of cultured diabetic ulcer fibroblasts and nonlesional diabetic skin fibroblasts revealed a large dilated endoplasmic reticulum, a lack of microtubular structures and multiple lamellar and vesicular bodies. These results show a diminished proliferative capacity and abnormal morphology of fibroblasts derived from diabetic ulcers of non-insulin-dependent diabetes patients.
Pathogenic aspects of psoriasis. Introduction.
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Use of cyclosporin in psoriasis.
In the treatment of severe psoriasis, cyclosporin may achieve improvement or remission at low doses, but relapse usually occurs on withdrawal of treatment. An initial dose of 3 mg/kg per day is recommended. Complete remission should not be the objective, and the role of long-term maintenance cyclosporin therapy is uncertain because of potential side-effects--especially nephrotoxicity, hypertension, and a predisposition to malignancy. Guidelines are proposed for the assessment of such treatment.
Defensins and complement systems from the perspective of skin immunity and autoimmunity.
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Cyclosporine immunotherapy.
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Efficient debridement of necrotic wounds using proteolytic enzymes derived from Antarctic krill: a double-blind, placebo-controlled study in a standardized animal wound model.
Wound healing can be accelerated by removing necrotic tissue. Various methods of wound debridement have been developed, including enzymatic debridement. Recently potent proteolytic enzymes were isolated from the intestine of Euphausia superba (Antarctic krill) that might be useful for degrading necrotic tissue. The purpose of this study was to evaluate the debriding properties of krill enzymes, using a specially designed animal model and a computerized analysis system. In 10 female domestic pigs, each weighing 20 kg, 6 artificial ulcers were made on each animal's back using electrokeratome, followed by application of trichloracetic acid. Ulcers were treated twice daily for 7 days with either krill enzymes at different concentrations or with saline. Reduction of necrotic tissue was measured daily using computerized wound analysis. Histological examination included the determination of bromodeoxyuridine incorporation in order to detect cell proliferation as well as routine stains. The debriding effect of krill enzymes at a concentration of >/= 3.0 casein units per ml was significantly better than saline control treatment (p < 0.05). The effect was dose dependent, and granulation tissue formation was enhanced. In conclusion, krill enzymes are effective in wound debridement, as measured in this animal model.
Treponemicidal levels of amoxicillin in cerebrospinal fluid after oral administration.
Seven patients in various stages of syphilis were treated by oral administration of amoxicillin (6 g daily) and probenecid (2 g daily) for 15 days. The treponemicidal level of amoxicillin was studied by a Treponema pallidum immobilization assay and found to be 0.070 micrograms/ml, as compared with 0.003 micrograms of penicillin/ml. Taking into account the WHO-recommended level of 0.018 micrograms/ml of penicillin, the minimal level of amoxicillin was estimated as 0.42 micrograms/ml. This level was obtained in serum and cerebrospinal fluid (CSF) of all patients treated with the above mentioned oral combination. It is concluded that treponemicidal levels of amoxicillin can be obtained in CSF after oral administration. The amoxicillin regimen described may be a valuable alternative to single-dose parenteral penicillin in the treatment of syphilitic patients with suspected CNS involvement, provided that reasonable compliance can be obtained.