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Biomedical subjects

Jürg Hafner

Publications and source records attributed to Jürg Hafner.

At least 19 recordsLinked to original sources
PubMed2006

Immunohistochemical differentiation and localization analysis of sweat glands in the adult human axilla.

BACKGROUND: The classic concept of axillary glands differentiates between eccrine glands, producing abundant clear, nonodorous sweat; and apocrine glands, excreting small amounts of turbid, odorous milky sweat. A third type of sweat glands, the "apoeccrine" glands, were recently identified. To define the different types of sweat glands and their location and number, the authors carried out a prospective histologic study on adult human axillary skin, including various immunohistochemical markers. METHODS: Forty-three consecutive Caucasian, subjectively normhidrotic patients, who underwent a surgical procedure in the axilla unrelated to the axillary glands, were included in the study. For verification of normhidrosis, the gravimetric test was carried out by measuring the amount of sweat secretion per minute. Then, a 1 x 1-cm measuring piece of skin and subcutaneous tissue was excised in the apex of the axilla, divided into three samples--altogether, 129 samples--and processed for histologic examination. RESULTS: In the dermis, the authors found only very few eccrine (average, 0.3 gland/cm in only 12 percent of all patients) and apocrine glands (average, 0.1 gland/cm in only 4.7 percent of patients), and no apoeccrine glands in any patient. In the subcutaneous tissue, the mean number of glands per centimeter squared was 10 for the eccrine glands, nine for the apocrine glands, and six for the apoeccrine glands. CONCLUSIONS: In the authors' Caucasian subjects, all or most of the sweat glands were found in the subcutaneous tissue near the border to the dermis and not in the dermis. For extremely hyperfunctioning sweat glands, the authors recommend less radical surgical methods, with the preservation of skin, based on the knowledge that most glands are localized in the subcutaneous tissue.

Adult↗
PubMed2006

Measurement of lower leg compression in vivo: recommendations for the performance of measurements of interface pressure and stiffness: consensus statement.

BACKGROUND: Interface pressure and stiffness characterizing the elastic properties of the material are the parameters determining the dosage of compression treatment and should therefore be measured in future clinical trials. OBJECTIVE: To provide some recommendations regarding the use of suitable methods for this indication. METHOD: This article was formulated based on the results of an international consensus meeting between a group of medical experts and representatives from the industry held in January 2005 in Vienna, Austria. RESULTS: Proposals are made concerning methods for measuring the interface pressure and for assessing the stiffness of a compression device in an individual patient. CONCLUSIONS: In vivo measurement of interface pressure is encouraged when clinical and experimental outcomes of compression treatment are to be evaluated.

Bandages↗
PubMed2006

A novel bioreactor microcarrier cell culture system for high yields of proliferating autologous human keratinocytes.

Rapid and efficient resurfacing of various skin defects by autologous keratinocyte transplantation is significant in skin wound healing. We developed a novel bioreactor microcarrier cell culture system (Bio-MCCS) to produce autologous human keratinocytes on a large scale. In this Bio-MCCS we used porcine gelatin microbeads as microcarriers for autolgous keratinocytes and spinning bottles as fermentation tanks. First, the microbeads were modified by culturing them with autologous dermal fibroblasts that were subsequently killed when they proliferated to confluence on the microbeads. We then performed the Bio-MCCS by expanding ketatinocytes on the microbeads in spinning bottles at 37 degrees C, 5% CO2. Our results showed that keratinocytes rapidly attached to and actively proliferated on the modified microbeads in the Bio-MCCS, achieving high cell densities on the modified microbeads (MTT assay and PI staining). Keratinocytes cultured on the modified microbeads in the Bio-MCCS remained proliferating potentials as shown by positive PCNA staining and BrdU labeling. In contrast, keratinocytes cultured on nonmodified microbeads in the Bio-MCCS proliferated slowly, rapidly ceased to proliferate, and finally dislodged from the microbeads. When removed from the Bio-MCCS and cultured under static conditions, keratinocytes were able to leave the modified microbeads and formed a multilayered epidermal equivalent on the culture surfaces. While stored at room temperature, keratinocytes remained at higher viabilities on the modified microbeads when compared to those on nonmodified microbeads. The achievement of high yields of proliferating autologous keratinocytes by this Bio-MCCS offers a practical potential of resurfacing various skin defects by direct administration of autologous keratinocyte microbeads on various skin defects.

Animals↗
PubMed2006

High yields of autologous living dermal equivalents using porcine gelatin microbeads as microcarriers for autologous fibroblasts.

Permanent skin replacement requires a dermal component to ensure adequate long-term graft stability and to prevent wound contraction. This study was to construct a bioreactor microcarrier cell culture system (Bio-MCCS) to produce autologous living dermal equivalents on a large scale. Autologous fibroblasts were isolated from split-thickness skin biopsy from a leg ulcer patient, inoculated onto macroporous porcine gelatin microbeads, and incubated in a bioreactor (Cellspin) in serum-free fibroblast growth medium or in DMEM medium containing 10% fetal calf serum (FCS). Fibroblasts rapidly adhered to and actively proliferated on the microbeads in the bioreactor in both serum-free and serum-containing medium. MTT assay showed the number of fibroblasts on the microbeads reached up to 5.3- or 4.0-fold the cells seeded in DMEM medium containing 10% FCS or serum-free medium, respectively. When removed from Bio-MCCS and cultured under static conditions, fibroblasts were able to leave the microbeads and proliferate to confluence on the bottom of tissue culture flasks. When stored at room temperature in DMEM containing 10% FBS, fibroblast cultured on the microbeads retained highest viabilities for at least 3 weeks, up to 82% of originals. This Bio-MCCS using porcine gelatin microbeads as carriers for fibroblasts offers a new option of mass production of autologous living dermal equivalents.

Animals↗
PubMed2004

Imiquimod treatment induces expression of opioid growth factor receptor: a novel tumor antigen induced by interferon-alpha?

PURPOSE: Imiquimod represents a synthetic local immune response modifier that has demonstrated efficacy in clearing basal cell carcinoma. Via interaction with Toll-like receptor 7 on immune cells, imiquimod induces local production of cytokines, such as interferon (IFN)-alpha. EXPERIMENTAL DESIGN: To more closely define and elucidate mechanisms leading to basal cell carcinoma clearance in vivo, we examined gene expression profiles of skin basal cell carcinoma before and after treatment with 5% imiquimod cream (Aldara) by using high-density oligonucleotide arrays. RESULTS: We show that imiquimod predominantly induces genes involved in different aspects of immune response. In addition to effects on immunity, imiquimod treatment modulates the expression of genes involved in the control of apoptosis and oncogenesis. Array data indicated that imiquimod treatment induces expression of opioid growth factor receptor, a molecule recently reported to be a target for antitumor antibody responses. Immunohistochemistry revealed in vivo up-regulation of opioid growth factor receptor protein on tumor and on infiltrating cells after treatment. By using basal cell carcinoma cell lines treated with IFN-alpha or imiquimod, we show that opioid growth factor receptor up-regulation is IFN-alpha-mediated, rather then directly imiquimod-mediated. By using tissue microarray containing 52 basal cell carcinomas, we demonstrate opioid growth factor receptor expression in almost half of the cases. Expression of opioid growth factor receptor correlated with a longer recurrence-free period in basal cell carcinoma that recurred after radiotherapy (Kaplan-Meier analysis, P = 0.041). CONCLUSIONS: In addition to its immunomodulatory and antiproliferative activity, opioid growth factor receptor seems to have a prognostic significance in basal cell carcinoma patients. Our data add to the growing list of basal cell carcinoma-associated tumor antigens.

Adjuvants, Immunologic↗
PubMed2004

Topical photodynamic therapy in the treatment of actinic keratoses and Bowen's disease in transplant recipients.

BACKGROUND: Transplant recipients (TR) have a dramatically increased risk for widespread epithelial neoplasms of the skin. Thus, there is a need to treat initial stages of these neoplasms such as actinic keratoses (AK) and Bowen's disease (BD) to prevent progression to invasive and potentially fatal squamous cell carcinoma. Topical photodynamic therapy (PDT) has been proven to be an effective treatment for AK and BD in immunocompetent patients, but no prospective trials in immunocompromised TR have been performed so far. METHODS: Twenty TR and 20 controls with histologically confirmed AK or BD underwent either a single or two consecutive treatments of topical PDT in an open trial. The application of 20% 5-aminolevulinic acid (ALA) for 5 hours was followed by illumination with 75 J/cm2 of visible light delivered at 80 mW/cm2 by an incoherent light source. RESULTS: The overall complete response rates in TR at 4, 12, and 48 weeks were 0.86, 0.68, and 0.48, respectively. The cure rates in both patient groups were comparable at 4 weeks but were significantly lower in TR than in controls at 12 and 48 weeks (P<0.05). Side effects included erythema, edema, and crust formation after illumination. Cosmetic results were excellent without scar formation or alterations in pigmentation. CONCLUSIONS: Topical PDT with 20% 5-ALA is an effective and safe treatment for AK and BD in immunosuppressed TR, with initial response rates comparable with those in immunocompetent patients. It is particularly useful in TR because of the possibility for repeated treatment of large lesional areas.

Administration, Topical↗
PubMed2004

Febrile ulceronecrotic Mucha-Habermann disease with clonality: a cutaneous T-cell lymphoma entity?

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD) is a severe variant of pityriasis lichenoides et varioliformis acuta (PLEVA). PLEVA patients only very rarely have systemic signs; the cutaneous lesions are usually asymptomatic, but may be pruritic and may heal with scarring. FUMHD often starts out as classic PLEVA, but goes on to develop widespread ulceronecrotic lesions and is associated with a high mortality rate. Whether Pityriasis lichenoides chronica (PLC) and PLEVA form a spectrum rather than single entities of clonal lymphoproliferative diseases has been discussed. Recently, it has been proposed that FUMHD, too, is a clonal lymphoproliferative disorder. Here, we report two cases of FUMHD with monoclonal T-cell population, as detected by Southern blot analysis. We propose that clonal FUMHD represents a cutaneous T-cell lymphoma entity.

Adult↗
PubMed2004

Bioreactor microcarrier cell culture system (Bio-MCCS) for large-scale production of autologous melanocytes.

Restoration of cutaneous pigmentation can be achieved in stable vitiligo by autologous cultured melanocyte transplantation. It was the goal of this study to construct a bioreactor microcarrier cell culture system (Bio-MCCS) to produce autologous melanocytes in large scale. In this Bio-MCCS, porcine gelatin microbeads were used as microcarriers, spinning bottle as fermented tank. Autologous melanocytes were able to attach to and proliferate on the gelatin microbeads in serum-free melanocyte medium in the Bio-MCCS, reaching up to 24-fold the cells seeded on day 15 (MTT assay). These autologous melanocytes cultured on gelatin microbeads could leave the microbeads and proliferate on the bottom of tissue culture flasks. Although Pluronic F68 has been widely used to protect animal cells from hydrodynamic stress in animal cell bioreactors, Pluronic F68 at a concentration of 0.25-1.0% showed no significant protective effects on the autologous melanocytes cultured on the microbeads and subjected to mechanical stress in the Bio-MCCS. This Bio-MCCS using porcine gelatin microbeads as microcarriers enabled large-scale production of autologous melanocytes, offering a potential treatment for large-area stable vitiligo by direct administration of the melanocytes cultured on the gelatin microbeads to the vitiliginous site.

Adult↗
PubMed2003

CO2 laser treatment of warts in immunosuppressed patients.

BACKGROUND: A large proportion of chronically immunosuppressed patients suffer from recalcitrant viral warts. Furthermore, the incidence of nonmelanoma skin cancer is clearly elevated in this patient group and human papillomavirus is most likely to play a causal role in these neoplasms. OBJECTIVE: To analyze the effectiveness of treatment of viral warts with the CO(2) laser in immunosuppressed patients. METHODS: Multiple viral warts of 13 patients with immunosuppression, a majority of them renal allograft recipients, were treated with CO(2) laser in local or regional anesthesia. In case of recurrences, the lesions were treated again after 3 months. RESULTS: 12 of 13 patients experienced dramatic improvement after 1-3 treatment sessions, 6 of these patients showed full remission. Side effects such as postoperative pain or scarring were minimal. CONCLUSION: CO(2) laser treatment of recalcitrant warts in immunosuppressed patients shows promising results which are comparable to those in immunocompetent hosts. This offers a welcome enlargement of the array of therapies in this otherwise difficult-to-treat group of patients and may contribute to the reduction of risk factors for nonmelanoma skin cancer.

Adolescent↗
PubMed2002

Repair of cutaneous defects after skin cancer surgery.

The goal of this chapter is to present an overview of the main clinical applications of surgical repair in the various anatomical regions of the head. Special consideration will be given to the areas that require reconstruction and to possible problems and complications. Although the skin lesion often dictates the type of incision made, there are various options. The biggest advantage of flaps is the excellent aesthetic result; this is feasible because the skin is similar in color and texture to that being replaced, and moreover no contracture occurs. On the other hand, a flap requires additional incisions and tissue movement, which increases the risks of postoperative complications. The range of flaps that can be used is discussed in detail. Full-thickness skin grafts are an important and necessary tissue source for reconstructive surgery in the face. They must meet the functional and aesthetic challenge posed by the surgical defect and are usually chosen because of the lack of adjacent tissue. Whenever possible, the skin grafts should resemble the surrounding skin in texture, color and thickness.

Head and Neck Neoplasms↗