Biomedical subjects

J H Davina

Publications and source records attributed to J H Davina.

6 recordsLinked to original sources

PubMed1986

Feasibility of a concanavalin A-peroxidase labeling method to detect cancerous and precancerous lesions of the uterine cervix.

For the detection of cancerous and precancerous lesions in cervical cytopathology, the feasibility of a concanavalin A-peroxidase labeling procedure was tested and compared with the Papanicolaou method. To this end, the percentage of labeled flattened epithelial cells with a morphologically normal appearance present in cervical cell suspensions was determined. It was found that the mean labeling percentage of the control group was 71% (SD, 11%). The means for mild, moderate, and severe dysplasia groups were, respectively, 54% (SD, 19%), 48% (SD, 13%), and 44% (SD, 16%). The mean for the carcinoma in situ group was 32% (SD,11%), and for the squamous cell carcinoma group 16% (SD, 5%). It appeared that the labeling percentage gradually decreases with increasing atypia of the epithelium as confirmed by histological observation. A complete dissimilarity was found between healthy individuals and cancer patients. In a follow-up study it was found that the mean labeling percentage did not alter in cases of an unchanged stage of disease. A reestablishment of the normal concanavalin A-peroxidase labeling percentage often appeared once the cancerous or precancerous lesion was treated. In conclusion, the concanavalin A-peroxidase labeling method can be considered as a supplementary technique to the Papanicolaou method for the early detection of cervical cancer. It reduces the effect of sampling and screening errors of the Papanicolaou method, and it allows a more objective cytological diagnosis. In addition, it may possess prognostic significance.

Carcinoma in Situ↗

PubMed1985

Concanavalin A-peroxidase labeling in cervical exfoliative cytopathology. I. Labeling of normal squamous cells and the detection of cancer.

The lectin binding capacity of the cell surface of normal flattened exfoliated epithelial cells of the uterine cervix was investigated looking for differences between specimens from normal and cancer patients. The method used was a modified concanavalin A-horseradish peroxidase (Con A-HRP) labeling procedure. Both normal and cancer specimens contain labeled as well as unlabeled usual flattened cells. There is a distinct difference between the labeling intensity of labeled and that of unlabeled cells. Quantification of the labeling results has been achieved using a light microscope equipped with a computerized video system. Apparently healthy persons, having a percentage of labeled flattened cells between 54 and 94% (mean = 73%, SD = 10%, N = 40), were totally discriminated by this method from the cancer patients. These patients with a histologically confirmed squamous cell carcinoma, showed a labeling percentage between 10 and 22% (mean = 15%, SD = 4%, N = 10). Hormonal factors, such as phase of cycle and pill use, appeared to have no significant influence. Statistical analysis revealed that at least 99% of all healthy persons will have a labeling percentage above 45%, while at most 1% of the cancer patients will show a labeling percentage above 30%. When choosing the labeling percentage of 45% as critical value, the Con A-HRP labeling might serve as an additional detection method for cancer of the uterine cervix. Moreover, as it is based on the abundantly present normal cells, and not on the often scarce abnormal cells, the method is not liable to sampling and screening errors.

Adult↗

PubMed1985

Concanavalin A-peroxidase labeling in cervical exfoliative cytopathology. II. Routine assessment of labeling results.

Concanavalin A-peroxidase (Con A-HRP) labeling of exfoliated cells of the uterine cervix have been shown to possess clinical significance in the detection of cancer. In the present study, a more simple method is used instead of the earlier applied complicated method. These two procedures for the assessment of the labeling results are compared. The first method is an objective machine-aided assessment procedure, consisting of a light microscope connected with a video system used in the sliced mode. The second is a more subjective method using human visual assessment with a light microscope only. The latter method would be suitable for routine use, if it shows similar Con A-HRP labeling results as obtained with the machine-aided procedure. In comparison with the machine-aided assessment procedure, the visual assessment procedure is less accurate. Moreover, the visual assessment is accompanied by intraobserver (between day) and interobserver variations. Although the discriminatory capacity in the detection of cancer patients is significantly lower for the human visual assessment procedure, this difference is small. It is of clinical relevance that in general a complete discrimination of healthy individuals and cancer patients is still possible. Therefore, visual assessment with a light microscope only, is preferred because of its simple equipment, which allows this procedure to be used as a routine method.

Carcinoma, Squamous Cell↗

PubMed1984

Tannic acid binding of cell surfaces in normal, premalignant, and malignant squamous epithelium of the human uterine cervix.

Alterations in tannic acid (TA) binding capacity of cell surface carbohydrates in normal, premalignant, and malignant squamous epithelium of the human uterine cervix have been studied using electron microscopic visualization in combination with microdensitometric evaluation. While in normal epithelium there is distinct binding in four to five cell layers of the deep intermediate zone, cells of carcinoma in situ and invasive cancer lesions lack TA binding. In moderate dysplasia an intermediate reacting pattern is found. Deep intermediate cells in areas bordering the carcinoma in situ lesions do not show any binding, although their ultrastructure cannot be distinguished from similar cells in normal tissue. The TA deposition within the deep intermediate zone is probably related to the presence here of glycoprotein-containing membrane-coating granules. The finding that TA binding discriminates between cells in normal squamous epithelium and morphologically normal cells in juxtaposition with lesional areas in premalignant and malignant epithelium opens the possibility for a more reliable cytologic diagnosis of cervical epithelial neoplasia.

Carcinoma in Situ↗

PubMed1981

Cell surface morphology in epithelial malignancy and its precursor lesions.

The cell surface organization of cancer cells is of potentially great significance, as it may not only allow (early) diagnosis, but as it may also harbour markers for refined prognosis (degree of oncogenetic and metastatic potential), and targets for selective cancer (chemo- and immuno) therapy. With these aspects in mind, the present review deals with SEM work done on (pre-) malignant cells, both in vivo and in vitro, and in animal models. Attention, however, is focused on human cancer cells. Cancer cells in vitro may lose many of their original malignant characteristics, and show adaptations to culture conditions. Many other factors have been shown to influence cell surface morphology, such as cell cycle, cell contacts, and preparations technique. Cancer cells differ in their surface morphology from normal cells, and have an extra ordinary amount of surface activity. Human malignant epithelial cells show abundant long. pleomorphic microvilli, especially those present in effusions. In squamous epithelium (bladder, cervix) microridge system present on normal superficial cells are progressively replaced by microvilli which increase in number and degree of pleomorphism during experimental and clinical oncogenesis. The question of whether or not the appearance of long. Pleomorphic microvilli reflects an irreversible alteration of the epithelium, and thus provides an early marker of irreversible neoplastic transformation is considered and assessed on the basis of our work with (pre-) malignant cells of the human uterine cervix. Although SEM has contributed significantly to the description of oncogenesis, up to now it has no early diagnostic, prognostic or therapeutic significance.

Carcinoma, Squamous Cell↗

PubMed1981

Surface pattern differentiation of the epithelial cells of the human uterine ectocervix.

This review considers the SEM cell surface pattern of the human ectocervical stratified squamous epithelium and its differentiation during migration from the basal to the exfoliating layer. The outer surface of flattened superficial cells has been generally characterized by microridges. Although this surface pattern is indeed relatively stable -as follows from an apparently limited sensitivity to preparation factors- it also shows dependency on the hormonal state of the patient. In contrast to the superficial cells very little information is available on the surface structure of the normal intermediate, parabasal and basal cells. The deep surfaces of the superficial cell layers have been examined using a stripping technique, whereas the surfaces of the deeper cell layers have been investigated with a freeze-fracturing technique. During migration from the basal cell layer upwards, the following structural parameters change gradually: the shape of the cells, the size of the intercellular space and the length and width of the cellular processes. As a result of the differentiation process the flattened cells of the superficial zone acquire microridges and crests on the luminal side. These interdigitate respectively, with globular microvilli and furrows present on the basal side of the overlying cell. Crests and furrows delineate regions on the cell surface in which variable microridge- and microvillus-patterns appear. Because crests and furrows are not present on the cell margins but also more centrally on the surface, the cell surface shown "regional" differences. The functional significance of the cell surface structure is discussed. Whereas the surface processes of the basal and parabasal cells presumably are engaged in the enhancement of intercellular contact and must permit metabolic interchange with the intercellular space, the interdigitating processes of superficial cells probably deal with an increase of the surface adhesiveness and in particular the resistance to sideways movements.

Cell Adhesion↗