Biomedical subjects

H Sudhoff

Publications and source records attributed to H Sudhoff.

54 records · Page 3Linked to original sources

PubMed1999

[Autologous perichondrium-cartilage graft in the treatment of total or subtotal perforations of the tympanic membrane].

BACKGROUND: In myringoplasty or tympanoplasty, fascia of the temporalis muscle and perichondrium or cartilage-perichondrium composite grafts are most commonly used to reconstruct the tympanic membrane (TM). Primary failures or recurrent perforations in the anterior part of the TM frequently occur in cases of eustachian tube dysfunction or total perforations of the TM. The purpose of this paper is to introduce a perichondrium-cartilage composite graft for closure of total perforations of the TM. Twenty-one patients (17 adults, 4 children) were included in this study, all of whom had a total perforation of the TM. METHODS: An oval shaped piece of cartilage with perichondrium on one side was harvested from the cavum conchae. The cartilage was cut in the shape of a U without removing the inner layer of perichondrium. The inner diameter of the cartilage ring should be nearly the same as the diameter of the tympanic ring. This cartilage framework stabilizes and fixes the perichondrium and prevents the perichondrium from subsiding into the middle ear cavity. Shrinking of the perichondrium is also reduced by the cartilage ring. In all patients introduced in this study, the TM was closed and no residual perforation occurred. The hearing results in tympanoplasty were the same as in other techniques with a residual air-bone gap of about 20 dB. CONCLUSIONS: This technique seems to be a valuable method for the closure of total perforations of the TM. Especially in perforations near the anterior anular region the underlay technique with fascia or perichondrium is an uncertain method. The soft material which is only fixed by adhesion can easily be displaced during wound healing. The hearing results are comparable to that achieved in other techniques. Further studies with greater number of patients are necessary to assess long term results.

Adolescent↗

PubMed1998

[Tissue engineering of cartilagenous tissue. Vital cryopreservation].

The characteristics of in vitro synthesized cartilage tissue using tissue engineering techniques before and after cryopreservation are described. We determined cell survival, growth of extracellular matrix (collagen and proteoglycan) using a computer analysis system, and characterized the cell phenotype with a monoclonal antibody specific for collagen type II. Chondrocytes maintained a differentiated phenotype with collagen and proteoglycan synthesis before and after cryopreservation.

Cartilage↗

PubMed1997

A possible role of Helicobacter pylori infection in the etiology of chronic laryngitis.

In order to study a possible role of Helicobacter pylori infection in chronic laryngitis, we performed endoscopic and histological assessments in addition to a urease test for the bacterium in 35 patients with chronic hoarseness. Six of the patients investigated (17.1%) revealed a positive urease test of the laryngeal biopsy (four male and two female patients). These H. pylori-positive patients were treated with omeprazole and an antibiotic regimen using clarithromycin and metronidazole. This led to an eradication of the H. pylori and resolution of clinical signs and symptoms. These findings show a possible role of H. pylori infection in the etiology of chronic laryngitis in certain patients and can be important for clinical diagnosis and treatment.

Adult↗

PubMed1997

[Immunohistochemical studies with middle ear mucosal remnants in cholesteatoma].

The development of a middle ear cholesteatoma is usually associated with chronic inflammation and displacement of the mucosa present by the invading squamous epithelium. To analyze the clinically different behaviors of both epithelia, we used immunohistochemical methods to study the distribution and expression of interleukin-1 (Il-1), transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), epidermal growth factor-receptor (EGF-R), the proliferation marker MIB 1, c-myc proto-oncogene product and activation marker 4F2. Results stromal that keratinocytes in a cholesteatoma exhibited a much higher activation and proliferation rate when compared to middle ear mucosa cells. Middle ear epithelial cells showed no immunoreactivity for TGF-alpha, EGF-R, Il-1 and c-myc in contrast to the markedly positive immunoreactivity found in cholesteatoma matrix. The local release of cytokines and growth factors, such as TGF-alpha, EGF and Il-1 by inflammatory cells seems to be an important factor for the hyper-proliferative behavior of cholesteatoma epithelium. Our findings could contribute to the pathogenesis of middle ear cholesteatoma and give a possible explanation for the sustained progression of its growth leading to displacement of the middle ear mucosa.

Biomarkers↗

PubMed1997

Argyrophilic nucleolar organizer regions in auditory meatal skin and middle ear cholesteatoma.

Comparative silver-staining of argyrophilic nuclear organizer regions (AgNORs) was performed to study the proliferative activity of auditory meatal skin and middle ear cholesteatoma. AgNOR expression patterns were counted by standardized methods in two centres, Bochum and London, and mean numbers of dots per nucleus were calculated. Specimens of normal auditory meatal skin showed 1.54 dots/nucleus (n = 12) in the Bochum study, whereas cholesteatoma had 3.71 dots/nucleus (n = 21). In the London study normal meatal skin showed two dots/nucleus (n = 4), whereas acquired cholesteatoma (n = 8) gave a mean of 4.90 dots/nucleus and congenital cholesteatoma a mean of 4.70 dots/nucleus (n = 2). Our findings confirm the hyperproliferative state of middle ear cholesteatoma, suggest that the congenital variety of cholesteatoma may have a similar activity and indicate that AgNOR staining is a useful technique for assessing cellular proliferation in cholesteatoma and objectifying and quantifying its aggressive behaviour.

Cell Division↗

PubMed1996

Interleukin 1 (IL-1) and IL-1-receptor antagonist (IL-1-RA) in middle ear cholesteatoma: an analysis of protein production and biological activity.

Cytokine networks are now presumed to play an essential role in the pathogenesis of middle ear cholesteatoma. Of the factors identified in cholesteatoma, interleukin-I (IL-1)-alpha appears to be especially important because of its stimulation of keratinocyte proliferation as well induction of bone resorption. To further characterize the possible role of IL-1 in the pathogenesis of cholesteatoma, we quantified the levels of IL-1 and IL-1-receptor antagonist (IL-1-RA) present using the bicinchonic acid protein assay and enzyme-linked immunosorbent assay (ELISA) on tissue extracts from 20 cholesteatoma specimens. The presence of biologically active IL-1 was also analyzed, using the cell line LBRM-33 and an ELISA for the detection of interleukin-2 (IL-2). Human skin obtained from the external ear canal was used as control. The amounts of IL-1-alpha in cholesteatoma (34.9 +/- 19.5) were higher than in human skin (6.7 +/- 2.8). The observed differences were statistically significant by Student's t-test (P < 0.01). Skin samples showed elevated concentrations of IL-1-RA (248.3 +/- 30.2) in comparison to that in the cholesteatoma (80.8 +/- 13.5). This was also statistically significant (P < 0.01). Whereas IL-1 activity was not detected in skin samples, all cholesteatoma specimens studied showed a stimulation effect on the production of IL-2 when incubated with the cell line LBRM-33. The results point to an over-expression of IL-1 concurrent with a decreased secretion of IL-1-RA in middle ear cholesteatoma. Furthermore IL-1-RA production is deficient relative to total IL-1 production, resulting in the presence of active IL-1.

Biological Assay↗

PubMed1996

Immunohistochemical detection of proliferating cell nuclear antigen in middle ear cholesteatoma.

Cholesteatoma epithelium is characterized by a keratinocyte dysregulation accompanied by destruction of the ossicles and temporal bone. Immunohistochemical methods using antibodies to cell-cycle-related antigens can be used as a means for assessing various aspects of proliferation in cholesteatoma tissue. They also have the important advantage of preserving the spatial orientation of proliferating cells in histological sections. Proliferating cell nuclear antigen (PCNA) is a 36 kDa DNA-delta-polymerase-associated protein that is directly involved in the mechanisms of DNA synthesis. In the present study the expression of PCNA was investigated in formalin-fixed, paraffin-embedded biopsy specimens of cholesteatomas and normal skin. Normal skin revealed nuclear staining in a small number of keratinocytes (PCNA grade, 1.5) located in the basal cell layer. In contrast, an increased number of PCNA-labeled basal and suprabasal epidermal cells (PCNA grade, 9.3) were found in cholesteatoma samples. Our findings indicate that PCNA represents a reliable marker for epithelial proliferation, showing that cholesteatoma epithelium proliferates at a higher rate than normal epidermis. These findings also support the concept of keratinocyte dysregulation in middle ear cholesteatoma.

Cell Division↗

PubMed1996

Monoclonal antibodies against human chondrocytes.

Cell-specific antigens are mainly found in cells or membrane surfaces rather than in the surrounding matrix. However, until now it was not possible to produce antibodies specific for cellular structures of chondrocytes. In 1989, Lance (Immunol. Lett. 21:63-73; 1989) first established specific monoclonal antibodies for human articular chondrocytes tested only by immunofluorescence. Studies describing the specificity of these five antibodies (HUMC 1-5) and their relevance for immunohistological analysis of cartilage tissue were not available until now. Therefore, the aim of the following study was to investigate the distribution of HUMC 1, 2, 3, 4, and 5 in mesenchymal cells in vivo and in vitro immunohistochemically. Further investigations concentrate on the localization of chondrocyte specific antigens using immunoelectron microscopy. Immunohistological studies showed positive immunostainings with all five antibodies in human chondrocytes in vivo and in vitro. A cross-reaction with human fibroblasts and osteoblasts for the antibodies HUMC 2 and HUMC 5 was observed. Furthermore, a parallel loss of immunoreactivity for HUMC 1, HUMC 3, and HUMC 4 was observed in cultured chondrocytes indicating that the specific antigens vanish during differentiation observed in vitro. Subsequent immunoblot analysis employing collagens as antigens did not show any reactivity. Using immunoelectron microscopy, gold particle labeling was observed in intracytoplasmatic vesicles of isolated chondrocytes. Our results indicate that HUMC 1, HUMC 3, and HUMC 4 are specific for cartilage cells and might be suitable for immunohistological analysis of different cartilage tissues and pathologically altered chondrocytes.

Antibodies, Monoclonal↗

PubMed1996

Basement membrane in middle ear cholesteatoma. Immunohistochemical and ultrastructural observations.

We investigated the distribution of basement membrane zone (BMZ) components collagen type IV, collagen type VII, and fibronectin in human middle ear cholesteatoma, auditory meatal skin, and middle ear mucosa using both immunohistochemical and ultrastructural methods. Collagen type IV immunoreactivity of skin and middle ear mucosa is continuous in the BMZ, whereas cholesteatoma frequently showed absent immunoreactivity or focal discontinuities. Collagen type VII immunoreactivity is detected similarly within the BMZ of cholesteatoma and skin. Fibronectin immunoreactivity is observed within the dermoepithelial junction of skin and middle ear mucosa. In cholesteatoma, however, fibronectin immunoreactivity is markedly increased within the extrinsic BMZ and the subepithelial connective tissue. The ultrastructural arrangement of the BMZ of cholesteatoma is like that of skin; however, it exhibits distinct alterations of the lamina fibroreticularis and lamina densa. Our results outline cholesteatoma as a disease with disturbed cell matrix interactions analogous to those of wound reepithelialization.

Basement Membrane↗

PubMed1996

Epidermal growth factor receptor (EGF-R) in human middle ear cholesteatoma: an analysis of protein production and gene expression.

Previous studies have shown an altered epithelial cell proliferation in middle ear cholesteatoma, reporting an aberrant expression of epidermal growth factor receptor (EGF-R) glycoprotein by immunohistochemistry. In this study, we quantified the presence of EGF-R using enzyme-linked immunosorbent assays (ELISAs) on tissue extracts, as well as the EGF-R gene expression by in situ hybridization on frozen sections. Human skin obtained from the external ear canal was used as control. The amounts of EGF-R glycoprotein in cholesteatoma were very similar to those in human skin. Human skin showed EGF-R messenger RNA (mRNA) only in the basal layer. A higher percentage of cells hybridized for the anti-sense probes EGF-R was found in cholesteatoma epithelium. Furthermore, we could find suprabasal cells with EGF-R mRNA. Our results confirm that the abnormal growth of cholesteatoma epithelium is reflected in an aberrant expression of EGF receptor.

Binding Sites↗

PubMed1995

Determination of viability of cryopreserved cartilage grafts.

Although transplantation of preserved cartilage has assumed a role of great importance in reconstructive surgery, there are many divergent and contradictory opinions with regard to the outcome of cryopreserved cartilage. This study was formulated to assess the functional state of chondrocytes after cryopreservation. Freeze injury and survival were studied using the trypan blue dye exclusion test, functional assay for cell adhesion and transmission electron microscopy. The methods applied clearly proved that a greater part of the cartilage cells was irreversibly damaged by cryopreservation. Findings demonstrated that cryopreserved cartilage remained non-viable and was not able to originate new cartilage. Thus, such cartilage will be subject to resorption processes and not practical for reconstruction of parts of the skeleton subject to mechanical stress. The feasibility of cryopreservation techniques for providing vital cartilage substitutes needs further evaluation.

Adult↗

PubMed1995

Expression of a cell-cycle-associated nuclear antigen (MIB 1) in cholesteatoma and auditory meatal skin.

Middle ear cholesteatoma is often invasive with consequent bone destruction. Inflammatory stimulation of the underlying connective tissue, as well as an autocrine mechanism, may be responsible for the dysregulation and abnormal proliferative features of the keratinocytes in cholesteatoma. Comparative investigations were performed to assess the epithelial cell kinetics of cholesteatoma and normal auditory meatal skin. Monoclonal antibody MIB 1 immunostaining (which recognizes a nuclear antigen expressed by dividing cells) was applied using the alkaline phosphatase antialkaline phosphatase immunolabeling method. Specimens of normal auditory meatal skin (n = 7) revealed an average MIB 1 score (quotient of the MIB 1-positive cells and the total number of cells) of 7.6 +/- 2.2%. Cholesteatoma samples (n = 13) showed an average MIB 1 score of 17.4 +/- 8.9% and a heterogeneity of proliferating epithelial areas. Epithelial cones growing toward the underlying stroma exhibited high mitotic activity. Statistically, the results of this study confirm a highly significant increase in the proliferation rate of cholesteatoma keratinocytes, which had an MIB 1 score that was 2.3 times higher than the score for keratinocytes of normal external auditory meatal skin.

Antibodies, Monoclonal↗

PubMed1994

AgNOR counts in preneoplastic lesions of the bronchus.

Silver staining of argyrophil nucleolar organizer regions (AgNORs) has become a valuable method to assess cell kinetics in paraffin sections and separate benign from malignant lesions. As a putative technique for the distinction between regenerative and preneoplastic alterations of the bronchial mucosa we employed the Ag-staining method, evaluating the number of dots/nucleus and shape of the dots. Dots/nucleus were counted by by standardized methods, and mean and standard deviation were calculated. Comparative investigations were performed in bioptically obtained specimens of normal bronchial epithelium (1.94 +/- 0.1 dots/nucleus, n = 12), basal cell hyperplasia (2.22 +/- 0.13 dots/nucleus, n = 15), goblet cell hyperplasia (2.38 +/- 0.16 dots/nucleus, n = 17), squamous cell metaplasia (2.58 +/- 0.17 dots/nucleus, n = 25), squamous cell metaplasia with mild and moderate dysplasia (2.50 +/- 0.5 dots/nucleus, n = 15), squamous cell metaplasia with severe dysplasia and carcinoma in situ (3.10 +/- 0.47 dots/nucleus, n = 17), micropapillomatosis (2.20 +/- 0.21 dots/nucleus, n = 13) and early squamous cell carcinoma of the bronchus (4.40 +/- 0.74, n = 13). In preneoplastic lesions a variability in form and size of the dots was found. Though showing an increase in the number of dots/nucleus coincidentally with the degree of proliferative activity, the AgNOR method cannot be considered as a statistically significant tool in the evaluation of regenerative and preneoplastic lesions in bioptically obtained specimens.

Bronchi↗

PubMed1994

Functional characterization of middle ear mucosa residues in cholesteatoma samples.

Cholesteatoma epithelium is characterized by a keratinocyte dysregulation with an aggressive growth that leads to the destruction of normal middle ear mucosa. The abnormal behavior of cholesteatoma epithelium seems to be induced by the presence of a heavy immune cell infiltrate releasing different cytokines and growth factors in high amounts. Middle ear mucosa rests are often observed within the cholesteatoma stroma or adjacent to the advancing front of cholesteatoma epithelium. This study investigated the presence of interleukin-1 (IL-1), transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and epidermal growth factor-receptor (EGF-R) in the mucosa rests as well as the expression of an activation marker, 4F2. The findings were correlated with the features of a surrounding stroma with an enhanced immune cell infiltrate. Cholesteatoma epithelium showed a high staining intensity of IL-1, TGF-alpha, and EGF-R. In contrast to this, middle ear mucosa did not show any positive reactions for the mentioned factors. Epidermal growth factor immunoreactivity was found in neither cholesteatoma epithelium nor in middle ear mucosa residues. The authors found a high concentration of lymphocytes and macrophages in the surrounding stroma. Most of these cells expressed TGF-alpha, IL-1, and 4F2, suggesting an activated form. Results indicate that keratinocytes present in the middle ear mucosa do not appear to react to the stimuli released by the inflamed stroma, reflecting important differences in the cell biological features of the keratinocytes that form parts of both types of epithelium.

Cholesteatoma↗

PubMed1981

[Reference values for a new alpha-amylase determination in serum and urine (author's transl)].

Reference values for a new alpha-amylase estimation using maltoheptaose as substrate were determined in 251 healthy men and women in serum at 25 degrees C and at 30 degrees C and in urine at 25 degrees C. Sex dependency was not demonstrable. The following reference ranges are suggested: 30-100 U/l in serum at 25 degrees C, 40-130 U/l in serum at 30 degrees C, and 500 U/l in urine at 25 degrees C. In addition reference values for the relative percentual amylase-creatinine clearance (25 degrees C) of 0.25-4% and for amylase activity per mg creatinine (urine 25 degrees C) of 0.02-0.25 U/mg creatinine are suggested.

Adolescent↗

PubMed1981

[Pancreatic lipase: reference values at 25 degrees C (author's transl)].

Development of a new specific test for estimation of pancreatic lipase activity (EC 3.1.1.3.) required establishment of reference values. An upper reference range of 170 to 190 U/l at 25 degrees C was determined from a group of 368 females and 435 males aged 20 to 70 years. Values below 170 U/l are very likely to be normal, values above 190 U/l are considered pathological. Values between 170 and 190 U/l require further controls. For practical reasons age and sex dependency need not be accounted for as these influences are negligible.

Age Factors↗

PubMedDate not supplied

Identification of proliferating keratinocytes in middle ear cholesteatoma using the monoclonal antibody Ki-67.

Cholesteatoma epithelium is characterized by a keratinocyte dysregulation with aggressive growth subsequently destroying the middle ear mucosa. The monoclonal antibody Ki-67 recognizes a nuclear antigen expressed by cells in the G1, S, and G2/M phases being used to determine the growing cell fraction in tissue samples. Cryostat sections of skin and cholesteatoma biopsies were examined immunohistochemically for reactivity with Ki-67 using the alkaline phosphatase-anti-alkaline phosphatase method. Nuclear staining was seen in a small number of keratinocytes located in the basal cell layer of normal auditory meatal skin. In contrast, numerous cells of the basal and suprabasal layers in cholesteatoma were found to react with Ki-67. A cytoplasmic staining was also observed in both skin and cholesteatoma. In cholesteatoma, the cytoplasmic staining was stronger. These results clearly show that cholesteatoma epithelium proliferates at a higher rate than normal epidermis, confirming the hyperproliferative behavior of cholesteatoma.

Antibodies, Monoclonal↗

PubMedDate not supplied

[Angiogenesis in cholesteatoma of the middle ear].

Middle ear cholesteatoma is characterized by the presence of a keratinizing squamous epithelium with hyperproliferative features. Such growth can only be supported by abundant blood vessels. The presence and distribution of blood vessels in cholesteatoma was studied to determine the mechanisms responsible for its origin and maintenance. Cholesteatoma (n = 30) and retroauricular skin samples (n = 30) were studied with indirect immunoperoxidase and alkaline phosphatase anti-alkaline phosphatase methods. Antibodies were used to recognize endothelial cells (von Willebrand Factor VII), vascular basal membrane components (type VI collagen), intercellular adhesion molecules (ICAM-1, 1CAM-2), human histocompatibility antigen (HLA-II) as a marker for cellular activation, angiogenetic growth factors and their receptors (TGF-alpha and VEGF), lymphocytes (CD3), and macrophages (KiM8). The cholesteatoma stroma had numerous vessels with intact basal membrane. The vessel concentration was higher in regions with abundant macrophage infiltration. Perivascular cell infiltrates were positive for antibodies against angiogenetic factors and HLA-II. Endothelial cells had increased expression of intercellular adhesion molecules and angiogenetic growth factor receptors. These results confirm the presence of increased vascularization in cholesteatoma, which may play an important role in sustaining continuous abnormal growth.

Cell Adhesion Molecules↗