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Biomedical subjects

U Geissler

Publications and source records attributed to U Geissler.

At least 19 recordsLinked to original sources
PubMed2002

Proliferation and differentiation of rat calvarial osteoblasts on type I collagen-coated titanium alloy.

Several attempts have been made to improve osseointegration of titanium alloy as an implant material by modification of its surface. In the present study, proliferation, differentiation, and mineralization of osteoblasts on type I collagen-coated Ti6Al4V were investigated. The activity of alkaline phosphatase and the accumulation of calcium by osteoblasts grown on titanium alloy were significantly higher compared to cells grown on polystyrene. Precoating of the implant surface with type I collagen did not extensively affect proliferation, the activity of alkaline phosphatase, collagen synthesis, calcium accumulation, or the mRNA levels for collagen I alpha1, osteopontin, osteocalcin, MMP-2, and TIMP-2. Maximum collagen synthesis by osteoblasts was observed at day 4 of culture independent of the type of implant material. The specific activity of alkaline phosphatase reached its maximum at day 18 of culture. Accumulation of calcium and elevated mRNA levels for osteocalcin were found at day 22. These results indicate that collagen-coating alone is not sufficient to accelerate differentiation of rat calvarial osteoblasts on Ti6Al4V.

Alloys↗
PubMed2000

Collagen type I-coating of Ti6Al4V promotes adhesion of osteoblasts.

The initial contact of osteoblasts with implant surfaces is an important event for osseointegration of implants. Osseointegration of Ti6Al4V may be improved by precoating of its surface with collagen type I. In this study, the adhesion of rat calvarial osteoblasts to uncoated and collagen type I-coated titanium alloy was investigated over a period of 24 h. Collagen type I-coating accelerates initial adhesion of osteoblasts in the presence of fetal calf serum. One hour after plating, no differences in the percentage of adherent cells between the surfaces investigated were found. Adhesion of osteoblasts to uncoated surfaces was reduced by the GRGDSP peptide by about 70%, whereas adhesion to collagen type I-coated surfaces remained unaffected by treatment of the cells with the peptide. Cell adhesion to coated materials was reduced by about 80% by anti-integrin beta1 antibody. The integrin beta1 antibody did not influence the adhesion to uncoated titanium alloy. The results suggest that osteoblasts adhere to collagen type I-coated materials via integrin beta1 but not by interacting with RGD peptides, whereas adhesion to uncoated titanium alloy is mediated by RGD sequences but not via integrin beta1. Fibronectin does not seem to be involved in the adhesion of osteoblasts to either coated or uncoated titanium alloy.

Adsorption↗
PubMed1997

Diagnostic and prognostic relevance of malignancy-associated changes in cervical smears.

OBJECTIVE: For approximately 15 years, malignancy-associated changes (MACs) have been consistently found by means of high-resolution cytometry in different tissues, especially in visually normal appearing cervical cells. Their biologic nature is not yet fully understood. The aim of this investigation was to assess the expression of MACs in cervical smears and to evaluate their prognostic relevance. STUDY DESIGN: This study was performed on normal intermediate cells obtained from 53 cytologically positive and 78 cytologically negative cervical smears. From a second sample, 31 cases showing negative cytology were selected for a prospective longitudinal study. Densitometric and texture features were generated, and MACs were described on the basis of multivariate discriminant analysis. RESULTS: Discrimination between positive and negative cases was possible, with a correct classification rate of approximately 80%. After a mean period of 29.5 months, we noted no statistically significant increase in the incidence of cervical intraepithelial neoplasia in the group of healthy but MAC-positive women as compared to those who were MAC negative. CONCLUSION: MACs were constantly expressed in the epithelium of the cervix. Although their prognostic relevance remains unclear, MACs play an important role in the effort to automate cervical cytology.

Adult↗
PubMed1990

[Image analysis study of squamous epithelial cells in cytological smears of the uterine cervix].

The automated image analysis is a method, which may model essential effects of the cytologist's perception, combined with an increase of objectivity. We studied 9136 epithelial cells from 105 suspension smears of the cervix by means of image analysis. The results show that the process of maturation of squamous cells can be represented by image analysis parameters. Such a model enables an opposition of processes of differentiation and dedifferentiation. Furthermore subvisual changes in visual inconspicuous intermediate cells can be proved, too which appear in different degree correlated with the grade of dedifferentiation. At present a study is designed to investigate cases without any atypical cells, but having been classified as "positive cases" by the evaluation of intermediate cells in a long term follow-up.

Carcinoma, Squamous Cell↗
PubMed1989

[Non-puerperal breast secretion].

This study is a general review about the nonpuerperal secretion of the mammary gland, the cause and the diagnosis. The consequence is unimportant for the diagnosis of carcinoma. About 5 per cent of the breast cancer have pathologic secretion, in most cases a blood-stained one.

Breast Neoplasms↗
PubMed1989

[Epidemiology and clinical aspects of adenomatous and squamous epithelial cancers of the uterine cervix].

Compared studies on the epidemiology and clinic of adeno- and squamous-cell carcinoma of the uterine cervix are being carried out by means of a retrospective investigation. 1,481 cervix cancer patients were treated from 1972-1983. Among them were 64 adenocarcinoma patients who were compared with a group of squamous-cell cancer patients equal in number. It could be found out that the number of adenomatous cervical cancer has not become more frequent during the last 20 years - with 4.3% taking only a comparatively small portion within cancer of cervix uteri. There are not any appreciable differences between both cancer groups regarding such epidemiological features like average age, menarche, kohabitarche, number of pregnancies and deliveries as well as high risk behaviour and contraceptive habits. Chronic or frequent occurring cervicitis seems to be a common risk factor. For that reason it is of great importance to pay special attention to diagnosis and therapy of inflammations in the uterine cervix. Although 36% of the women treated took oral contraceptives a causal connection between the taking in of these preparations and the development of neoplasia could not be confirmed. Progress of the disease and healing tendencies have shown that adequate therapy - being in accordance to the respective stages - is effective in the mentioned histological variants of cervical cancer. Adeno- and squamous-cell carcinoma do not differ essentially concerning epidemiological and clinical features. It is assumed that pathological epithelial qualities show similar carcinogeneses.

Adenocarcinoma↗
PubMed1988

[Morphologic changes in the epithelium of the uterine cervix in long-term administration of the 19-norsteroid-containing oral hormonal contraceptives Non-Ovlon and gravistat].

The objective of this study was to give a contribution to the question whether there are changes in the uterine cervix after longterm application of 19-norsteroid-containing contraceptives Non-Ovlon and Gravistat relating to carcinogenesis. Histologic examinations have been performed on 19,760 cervical sections obtained from 280 women aged 25-45 years. 141 women had taken Non-Ovlon or Gravistat for at least 5 years, 139 women had never taken hormonal contraceptives. The cervices were equally obtained from surgical- and conization material from 1976 to 1982. The evaluation was made according to 108 single characteristics of quality, semiquantity and topography. These characteristics were evaluated by electronic data processing. Our investigations revealed no morphological evidence for a relation between longterm application of Non-Ovlon or Gravistat and the occurrence of squamous epithelial or adenomatous cervical neoplasias.

Adult↗
PubMed1988

[Abdominal metastasis in breast cancer].

Report about three patients which were operated on due to a suspicion of ovarian cancer. In all three cases we could observed metastases of a primary breast cancer. This could be confirmed clinically, mammographically and histologically. In this connection problems of early detection and differential diagnosis have been discussed.

Abdominal Neoplasms↗
PubMed1984

[Peritoneal cytology in the follow-up control of malignant ovarian tumors].

From 1976 to 1982 we practised 247 transvaginal punctures with peritoneal lavage with the aim of cytological follow-up of ovarian malignomas. Those who were submitted to this treatment were 73 women with ovarian carcinoma of stage I to III, in whom after operation, antineoplastic chemotherapy and possibly radiotherapy no tumor was no longer detectable clinically. In case of positive cytology puncture was repeated in intervals of three months, in case of negative findings of 6 to 8 months. 31.6 per cent of all puncture smears were cytologically positive and 53.8 per cent certainly negative. In 14.6 per cent of all cases no well defined statement could be allotted. We can recommend peritoneal lavage for monitoring of efficiency of therapy of ovarian carcinomas on account of its high evidence and trifling annoyance.

Cytological Techniques↗
PubMed1981

[Stepped therapy for patients with cervical carcinoma - precancerous and early phases (author's transl)].

Reported in this paper are 806 cases of carcinoma in situ and micro-invasive carcinoma of the uterine cervix (Phases 0 and Ia). All patients had been attended to in the Gynaecological Department of the Medical Academy "Carl Gustav Carus", Dresden, between 1969 and 1978. - The histological diagnosis was based on conisation. Conisation or hysterectomy with vaginal cuff was used for therapy. Reference is made to recurrences.

Adnexa Uteri↗
PubMed1980

[Malignant melanoma of the vagina].

The authors present the case of a malignant melanoma of the vagina. Simultaneously was noted a pigmented nodule on the left lower eyelid. This tumour was also diagnosed as a malignant melanoma. On the 38-year-old female patient a radical abdominal hysterectomy with total colpectomy and pelvic lymphadenectomy was performed. Thereafter the tumour of the left eyelid was excised and a bilateral groin dissection was performed. One left inguinal lymph node was pathologically positive involved. In addition the patient was subsequently treated with chemotherapy. She had a disease-free interval of 29 months following the radical surgery. Actual aspects of the therapy of this disease are discussed.

Adult↗