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Biomedical subjects

T Hunziker

Publications and source records attributed to T Hunziker.

At least 91 records · Page 5Linked to original sources
PubMed1992

[Palpable purpura].

Non-thrombocytopenic palpable purpura is a characteristic lesion of cutaneous leukocytoclastic vasculitis. In association with manifestations in the gastrointestinal tract, kidney and/or joints, it forms the clinical entity of Henoch-Schönlein purpura. Among 27,510 inpatients in the years 1974 to 1989 from the CHDM Berne/St. Gallen, 2 developed one, and a further patient as many as 4 episodes of leukocytoclastic vasculitis limited to the skin, which were probably related to drugs (most often compounds containing a sulfonamide, related structures or a penicillin). In contrast, among 8 additional cases from the same cohort, in which Henoch-Schönlein syndrome was diagnosed on admission to hospital, a drug etiology was suspected only in one patient. In these patients an involvement in addition to that of the skin of at least two other organ systems was documented. In our experience, a drug etiology should be considered in every case of leukocytoclastic vasculitis, but will mainly be validated in cases in which the lesions are limited to the skin.

Aged↗
PubMed1992

[Vasculitic skin lesions caused by nonsteroidal anti-inflammatory agents].

Today, non-steroidal anti-inflammatory drugs are very frequently prescribed agents. These drugs are responsible for side effects which are rarely recognized and poorly understood. One of these side effects is leukocytoclastic vasculitis with or without skin ulcerations. Rheumatoid arthritis and other mixed connective tissue diseases may also lead to vasculitis ulcerations, which explains the difficulty of correct diagnosis in each case. In addition, disease-modifying drugs such as methotrexate, frequently used in the above-mentioned syndromes, further complicate the situation because these agents may also produce vasculitis. In the present case study we analyze and discuss the diagnosis and follow-up in three of our patients with vasculitis skin ulcerations. In two of them, the vasculitis was attributed to the use of naproxen. Despite thorough examination and documentation of all three cases, etiologic evaluation was difficult and complex.

Aged↗
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

Co-culture of human keratinocytes on post-mitotic human dermal fibroblast feeder cells: production of large amounts of interleukin 6.

A large synthesis of human IL-6 was demonstrated in co-cultures of human keratinocytes on post-mitotic human dermal fibroblast (HDF) feeder layers. Immunoreactive IL-1 beta could be detected in the co-cultures and the addition of rabbit anti-IL-1 beta antibodies to the co-cultures considerably reduced the IL-6 synthesis, suggesting that it was induced by endogenous IL-1 beta. Addition of saturating concentrations of IL-1 beta to HDF feeder layers as well as to subcultures of keratinocytes induced in both similar but moderate IL-6 production. Conditioned medium from keratinocyte cultures induced IL-6 secretion in HDF feeder cells, whereas the conditioned medium from HDF feeder layers led to only minimal increase of keratinocyte IL-6 production. The co-cultures of keratinocytes on HDF feeder layers produced much larger amounts of IL-6 than the sum of the IL-6 produced by the feeder cell and keratinocyte cultures after the addition of IL-1 beta. The co-cultures of keratinocytes with HDF feeder layers separated by a permeable membrane in a two-chamber system produced significantly lower amounts of IL-6 than the unseparated co-cultures. These findings indicate that a direct cell contact between keratinocytes and feeder cells is involved in the overproportioned increase of IL-6 production and secretion into the medium.

Cell Communication↗
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↗
PubMed1992

Circulating immune complexes in patients with psoriasis: do they exist?

Sera from 16 patients suffering from active psoriasis without arthropathy (2 guttate, 10 nummular, and 4 mixed type) were examined for the presence of circulating immune complexes. Five routine laboratory assay systems were used, based on C1q-binding or detection of IgG-coupled C1q and C3-breakdown products. In 14 patients, no elevated levels of circulating immune complexes were detected. One patient, who additionally suffered from late-phase HIV-1 infection, showed C1q-binding activities as well as levels of IgG-coupled C1q and C3-breakdown products in four of the assay systems, which indicated the presence of immune complexes in his serum. In another patient, with nummular psoriasis, slightly elevated levels of circulating immune complexes were measured by two of the assay systems. These results question the hypothesis of an essential pathogenic role of circulating immune complexes in psoriasis.

Adult↗
PubMed1992

Sensitization to the isothiazolinone biocide. Report of the Swiss Contact Dermatitis Research Group 1988-1990.

The rate of sensitization to isothiazolinones (Kathon CG) detected in Switzerland rose from 3.5% (out of 2,491 patients) in 1987 to 6.3% (out of 982 patients) in 1988 and 5.6% (out of 2,295 patients) in 1989-90. This rate of sensitization appears to be related to the more and more widespread use of isothiazolinone biocide in cosmetics, domestic products and in industry.

Cosmetics↗
PubMed1991

Experimental modulation of the differentiated phenotype of keratinocytes from epidermis and hair follicle outer root sheath and matrix cells.

Follicles of human anagen hair were separated into morphologically distinct compartments (by sequential trypsinization and microdissection) for the biochemical and immunological analysis of keratins as differentiation markers to diagnose the type of epithelial differentiation. While outer root sheath contained throughout the "soft" (cyto)keratins K5, 6, 14, 16, and 17, and hair cortex contained exclusively a set of acidic and basic "hard" alpha-keratins (consistent up to the hair tip), in inner root sheath and hair cuticle peptides related or derived from suprabasal epidermal keratins K1 and 10 were detected. These keratin profiles served as in vivo correlates for the evaluation of type and degree of differentiation achieved by the respective isolated epithelial cells, comparing different growth or culture conditions. Cultures of ORS cells and hair matrix cells (PHS cells) as well as normal keratinocytes were initiated using postmitotic human dermal fibroblasts as efficient feeder cells. On lifted collagen gels populated with HDF ("surface" cultures), ORS and PHS cells formed stratified epithelial expressing epidermal differentiation markers such as keratins K1 and 10, involucrin, and filaggrin. Compared with NEK "surface" cultures, balance between growth and differentiation was better maintained by both follicular cell types. In contrast, epidermal tissue homeostasis was largely normalized in transplants on nude mice regardless of the epithelial cell type, apparent from orderly tissue structure, regular distribution of keratin K10, filaggrin, and involucrin, and distinct continuous deposition of basement membrane components at the epithelium-collagen interface. Embedded in Matrigel (on top of HDF collagen gels) ORS cells and NEK formed spheroids exhibiting inward-directed epidermoid differentiation, increasing with time. All epidermal maturation products found in "surface" cultures were likewise expressed, and again differentiation greatly outbalanced proliferation in spheroids of NEK but not of ORS cells. PHS cells embedded together with HDF in Matrigel produced similar spheroids as ORS cells. Size of spheroids and degree of epidermoid differentiation were dramatically reduced when HDF were replaced by follicular DP cells, demonstrating the crucial role of the mesenchymal "companion" cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Differentiation↗
PubMed1991

Restoration of the epidermal phenotype by follicular outer root sheath cells in recombinant culture with dermal fibroblasts.

In order to better understand how outer root sheath (ORS) cells are able to reepithelialize superficial skin wounds, the level of epidermal differentiation achieved by isolated ORS cells in vitro was determined. Using postmitotic human dermal fibroblasts (HDF) as efficient feeder cells, large numbers of ORS cells from individual follicles were generated. Passaged ORS cells were grown exposed to air on HDF-populated collagen gels in the CRD device (Noser and Limat, In vitro 23, 541-545, 1987) which allows histiotypic tissue organization. In such recombinant organotypic cultures, ORS cells developed distinct epidermal strata comparable to interfollicular keratinocytes (NEK). Ultrastructurally, desmosomes and intermediate filaments increased in number toward the epithelial surface and small keratohyalin (KH) granules (but no large irregular KH granules as in NEK) were abundant, adjacent to an electrondense stratum corneum. Also, synthesis of epidermal suprabasal keratins (K1 and 10;2D gels) was lower in ORS cultures, but clearly visible suprabasally by immunofluorescence along with other epidermal markers (involucrin, filaggrin, surface glycoprotein gp80, pemphigus vulgaris antigen). Basement membrane components (laminin, type IV collagen, bullous pemphigoid antigen) were detectable in both ORS and NEK in these assays. Thus, phenotypic expression was largely comparable, but, whereas terminal differentiation (keratinization) was progressing in NEK cultures limiting their lifespan, this seemed to be better controlled in ORS cultures and viable cell layers persisted resulting in longer survival time.

Adult↗
PubMed1991

Quantitative nailfold capillary microscopy in cutaneous and systemic lupus erythematosus and localized and systemic scleroderma.

Quantitative television microscopy of nailfold capillaries of the fingers was performed in 12 patients with cutaneous lupus erythematosus (six with discoid type and six with disseminated type), in six patients with localized scleroderma (two with circumscribed type, two with linear types, and two with atrophic type), in 10 patients with systemic lupus erythematosus, and in eight patients with systemic scleroderma. The following features were analyzed and compared with a control group (n = 15) of similar age: venous plexus visibility; density of capillaries; avascular fields; hemorrhages; giant capillaries; diameters of the transitional segment, the arterial, and the venous limbs; loop width; and flow stop caused by local cooling test. The patient groups with cutaneous lesions only showed no essential differences as compared with the controls. Patients with systemic scleroderma differed in almost every finding from the controls and from patients with localized scleroderma. Patients with systemic lupus erythematosus exhibited significant differences in several findings as compared with the controls and the cutaneous lupus erythematosus group, but there was overlap.

Adolescent↗
PubMed1991

[Sneddon syndrome].

A 44-year-old female with Sneddon's syndrome, i.e. generalized racemose livedo and recurrent cerebrovascular disease, is presented. Significant levels of IgG anticardiolipin antibodies were found in her serum.

Adult↗
PubMed1990

Effects of culture and incubation conditions on membrane fluidity in monolayers of cultured cells measured as fluorescence anisotropy using trimethylammoniumdiphenylhexatriene (TMA-DPH).

Membrane fluidity of coverslip attached living cells was measured as fluorescence anisotropy using 5 microM trimethylammoniumdiphenylhexatriene (TMA-DPH) as fluorescent probe. Fluorescence anisotropy is inversely related to membrane fluidity. Cells were grown on glass coverslips that were inserted and directly incubated in quarz cuvettes. The coverslips were fixed with special holders at an angle of 30 degrees in respect to the incident light. Effects of incubation temperature, of cell growth and densities and of the ionic and nonionic composition of the incubation medium on membrane fluorescence anisotropy were measured. Membranes of growing cells were more fluid than those of stationary cells, while cell densities had no effect except at very low cell numbers. Calcium concentrations increasing from 0 to 8 mmol/l in the incubation medium proportionally decreased membrane fluidity. Hypotonicity of the incubation media increased membrane fluidity while hypertonicity compared to normotonicity had no effect. Differentiated human fibroblasts from different origins exhibited similar membrane fluidities. They were, however, different from those of rat cells. Membrane fluidity of rat brain tumor cells increased with age in culture while membrane fluidity of primary differentiating rat brain cells decreased in with age in culture. Measurement of fluorescence anisotropy in living cells attached to glass coverslips is a convenient tool to study effects of culture--as well as of environmental--conditions on membrane fluidity.

Animals↗
PubMed1990

Postmitotic human dermal fibroblasts preserve intact feeder properties for epithelial cell growth after long-term cryopreservation.

In vitro, human dermal fibroblasts (HDF) differentiate through morphologically and biochemically identified compartments. In the course of this spontaneous differentiation through mitotic and postmitotic states, a tremendous increase in cellular and nuclear size occurs. Induction of postmitotic states can be accelerated by chemical (e.g., mitomycin C) or physical (e.g., x-ray) treatments. Such experimentally induced postmitotic HDF cells support very efficiently the growth of cutaneous epithelial cells, i.e. interfollicular keratinocytes and follicular outer root sheath cells, especially in primary cultures starting from very low cell seeding densities. The HDF feeder system provides more fundamental and also practical advantages, i.e. use of initially diploid human fibroblasts from known anatomic locations, easy handling and excellent reproducibility, and the possibility of long-term storage by incubation at 37 degrees C. Conditions for the cryogenic storage of postmitotic HDF cells in liquid nitrogen are presented and related to the feeder capacity for epithelial cell growth. Because postmitotic HDF cells preserve intact feeder properties after long-term storage, the immediate availability of feeder cells and the possibility to repeat experiments with identical materials further substantiate the usefulness of this feeder system.

Cell Division↗
PubMed1990

Mastocytosis and atopy: a study of 33 patients with urticaria pigmentosa.

Thirty-three patients with histologically verified urticaria pigmentosa were studied for coexisting atopic disease by means of history, skin prick testing with five common inhalants and serological investigation for total IgE and specific IgE antibodies to five common inhalants. The prevalence of atopy in urticaria pigmentosa was similar to that observed in the normal Swiss population, both on the basis of history (7/33 = 21%) and of positive skin prick tests to common inhalants (12/33 = 36%). However, total serum IgE levels were significantly lower (geometric mean value 16.8 kU/l) than in a control group of 52 Swiss blood donors of comparable age and sex distribution (geometric mean value 43.0 kU/l, t = 2.93, P less than 0.005). Specific IgE antibodies to common inhalants were also observed less frequently in urticaria pigmentosa patients than in controls, although this difference was not statistically significant. Low total and specific IgE values in patients with urticaria pigmentosa may be explained by increased absorption of circulating IgE to abundant tissue mast cells.

Adolescent↗
PubMed1989

In vitro pemphigus vulgaris model using organotypic cultures of human epidermal keratinocytes.

Using the Combi-ring-dish (CRD), a new culture device, organotypic cultures of human epidermal keratinocytes were grown on bovine eye lens capsules. In these highly differentiated cultures, typical suprabasal acantholysis was induced by pemphigus vulgaris antibodies. This in vitro pemphigus vulgaris model may be used to analyse keratinocyte-derived factors causing acantholysis in experimental pemphigus.

Acantholysis↗