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Biomedical subjects

I Nenci

Publications and source records attributed to I Nenci.

At least 37 records · Page 2Linked to original sources
PubMed1990

Assessment of proliferative rate of breast cancer by Ki-67 monoclonal antibody.

The proliferative activity of 163 primary breast cancers was assessed by immunocytochemistry with the mouse monoclonal antibody Ki-67, which recognizes a nuclear antigen expressed in all phases of the cell cycle except for Go. The overall frequency distribution of Ki-67 staining was of exponential type, with percentage of positive staining cells ranging from 0.3 to 88.3%, with a median value of 10.1%. No relationship was observed between Ki-67 values and menopausal status of patients. A significant positive correlation was found between Ki-67 values and tumor grade, especially mitotic grade. Estrogen Receptors (ER) were assayed by immunocytochemistry with ER-ICA method and by dextran-coated charcoal method (DCC) in 129 and 141 tumors, respectively. A negative correlation was found between the ER content by both methods and Ki-67 score. Eighty-nine percent of cases with Ki-67 value less than 10.1% contained more than 10% ER-ICA-positive cells. Progesterone receptors (PgR) were assayed by immunocytochemistry with PgR-ICA method and by DCC in 62 and 141 tumors, respectively. A negative correlation was observed between the PgR content by both methods and Ki-67 score. No correlation was found between Ki-67 score and lymph node involvement by tumor. These findings suggests that Ki-67 score could be used as an independent prognostic marker, useful to distinguish different risk for recurrence within the two clinically heterogeneous groups of N- and N+ patients.

Adult↗
PubMed1989

Monoclonal antibodies for specific immunoperoxidase detection of Campylobacter pylori.

Monoclonal antibodies were raised against Campylobacter pylori to detect the organism in clinical specimens by the immunoperoxidase technique. Twenty-one hybridoma cultures obtained were screened on tissue sections of gastric mucosa to identify antibodies that did not cross-react with host cells. To select antibodies with high grade of specificity to C. pylori, hybridomas were also screened by an enzyme-linked immunosorbent assay against a wide panel of gram-negative bacteria. Fifteen antibodies showed a variable grade of cross-reactivity with gastric mucosa, indicating the presence of at least three epitopes shared by C. pylori and epithelial cells. Three of the six antibodies non-reacting with gastric mucosa (CB-1, CB-26, and CB-31) also were found to be specific for C. pylori. Using CB-26 in an indirect immunoperoxidase test, gastric brushings from 60 patients consecutively undergoing endoscopic examination were examined. By light microscopy, we observed the presence of large amounts of C. pylori in smears from all the 32 patients with positive culture. A small number of bacterial cells were also seen in 8 of 28 patients whose cultures were negative. These findings suggest that the monoclonal antibody CB-26 might be of value for rapid and specific detection of C. pylori.

Animals↗
PubMed1988

Expression of p21 ras gene products in breast cancer relates to histological types and to receptor and nodal status.

Expression of the p21 product of the ras gene family was investigated in a series of 142 infiltrating primary breast tumors by two specific ras p21 monoclonal antibodies with an immunocytochemical technique. The majority of tumors demonstrated a varying number of positive cells. A significant association between p21 expression and tumor histotype was found: among ductal carcinomas the comedo variety was always positive; conversely, lobular tumors were more frequently negative. Nodal status was recorded for all patients. A significant difference was found in nodal status with respect to p21 expression: tumors with more than 50% positive cells were more often N+. Estrogen receptor (ER) status was determined in 77 tumors. Tumors with higher levels of p21 contained a high percentage of estrogen receptor positive cells. The present results show that p21 expression in human breast cancer could be a marker of tumor aggressiveness and might thus improve the predictive power of known prognostic factors such as estrogen receptor and nodal status.

Breast Neoplasms↗
PubMed1988

Commentary on human mammary preneoplasia. The estrogen receptor-promotion hypothesis.

In the carcinogenic process, promotion is the process whereby an initiated tissue develops focal proliferations which act as proximate precursors. The evidence obtained from the immunocytochemical staining by monoclonal anti-receptor antibodies indicates that the early steps (atypical hyperplasias) in the carcinogenic process of the breast show an increased and homogeneous expression of the estrogen receptor. These observations suggest that the persistent sensitivity to estrogen may be critical in sustaining the growth of mammary preneoplastic changes and their progression to ultimate precursors and to invasive cancer.

Breast Neoplasms↗
PubMed1987

Immunocytochemical demonstration of estrogen receptors by monoclonal antibodies in human breast cancer: correlation with estrogen receptor assay by dextran-coated charcoal method.

Immunocytochemical demonstration of estrogen receptors in 115 human breast cancer specimens was performed using mouse monoclonal antibodies against estrogen receptor and avidin-biotin as the displaying system. The antibody indicated a highly heterogeneous endowment of neoplastic cells with estrogen receptor at both nuclear and cytoplasmic levels. The percentage of labeled cells within each tumor specimen was recorded to compare this immunocytochemical assay with the biochemical assay of estrogen receptors by the dextran-coated charcoal method. A significant correlation was observed between these two assays. The present results show that estrogen receptors can be confidently demonstrated at the single cell level, thus providing additional information to quantitative biochemical assays. Their prognostic and therapeutic predictive powers may be usefully integrated, particularly in view of the heterogeneous distribution of receptors among cancer cells.

Antibodies, Monoclonal↗
PubMed1987

Pathophysiology of estrogen receptors in mammary tissue by monoclonal antibodies.

Identification of preneoplastic lesions of the breast has mainly rested on morphological grounds, supported by epidemiological data. These studies assign a definite precancerous potential to a group of atypical hyperplastic lesions and in situ carcinoma. In spite of much effort no criteria are yet available to understand which, among these lesions, is committed to infiltrative growth, in other words, to understand the risk to a single patient. Estrogens are know to play a critical role in the etiology of breast cancer. The hypothesis is investigated that this role is dependent on a modified expression of their receptor. To approach this question estrogen receptor expression was traced by specific monoclonal anti-receptor antibodies and immunocytochemistry, on a spectrum of breast tissue changes, from normal tissue to infiltrating cancer. Estrogen receptor expression is heterogeneous in normal tissue and in infiltrating cancer, and on the contrary is homogeneous in proliferative atypical lesions and in in situ carcinomas. Present results show that receptor expression is enhanced and becomes homogeneous, maybe constitutive, in atypical hyperplasia and in in situ carcinoma and that this phenomenon could subserve important changes of proliferative capacity which are necessary and possibly sufficient for autonomous growth.

Breast↗
PubMed1985

Expression and modulation of estrogen receptors in human breast cancer.

Estrogen receptors have been traced at the tissue level in premalignant and malignant changes of human mammary gland by an immunoperoxidase technique using a monoclonal antibody against the receptor protein. Proliferative premalignant cells show an increased and homogeneous expression of the estrogen receptor by this technique; it seems that a constitutive expression of the receptor may play a role in the promotional carcinogenetic process. Moreover, infiltrating tumors show a striking heterogeneity in the cellular expression of estrogen receptor, which seems related to differentiation level.

Antibodies, Monoclonal↗
PubMed1981

Estrogen receptor cytochemistry in human breast cancer: status and prospects.

Advances in knowledge of the endocrine control of neoplastic growth can be expected to stem directly from advances in pertinent techniques. Following this theme, the present paper describes how recent development in cytochemical techniques for estrogen receptors may maintain this expectation and lead to significant progress in the basic knowledge of breast cancer that can influence the treatment approach. Cytochemical techniques have shown that the binding of estrogen to target cells and tissues can be specifically visualized: moreover, estrogen binding sites characterized cytochemically under controlled conditions have proved to fulfill the accepted criteria for estrogen receptors. Some working solutions to basic questions concerning the tumor hormone-responsiveness have been provided and more precise explanations of fundamental growth-regulatory mechanisms are expected to emerge from the approach to breast cancer by cytologic endocrinology. However, in the present state of the art and in spite of tantalizing bits of data, cytochemical techniques for estrogen receptors do not seem extensible to routine purposes, as alternative to biochemical receptor assays in selecting patients for endocrine therapy. One must have strong reservations on their clinical use because of the almost complete lack of information about correlations of cytochemical results with the response to endocrine therapy. More studies evaluating the practical validity of estrogen receptor cytochemistry are required.

Breast Neoplasms↗
PubMed1980

Possible indication of breast cancer risk through discriminant functions.

In the Ferrara province of Italy, a screening programme for the detection of breast cancer was initiated in 1965; by 1976, 21,120 women had been examined. The biologic history of the women participating in the program is routinely collected at registration. Several biological variables can be extracted from the history. We used 15 biologic variables in order to construct discriminant functions between women affected by breast cancer and a group of control women. It was found that four variables suffice to separate the group of the women with breast cancer from the control group, although with some degree of uncertainty. The theory was advanced that the individual values of a discriminant function may be associated with the risk of healthy women for developing breast cancer. Data collected after the construction of the discriminant function hint at such an association. We have attempted to calculate a discriminant value for healthy women participating in screening programs, so that those having a discriminant value below a given threshold may be considered at higher risk than those above the threshold. The women in the high-risk group may then be submitted to an appropriate examination schedule.

Adult↗
PubMed1980

Intracellular flow of particulate steroid-receptor complexes in steroid target cells.

The structural expression of nuclear transportation of receptor-bound oestradiol was investigated by immunoelectron microscopy on human breast cancer cells. In oestradiol-treated cells during transportation, oestradiol antibodies attached to cytoplasmic oestradiol-bearing particles which seemed to interact with the nuclear membrane. These particles, subserving the intracellular flow of steroid-receptor complexes, could constitute a special cellular system of macromolecular transport, communication and compartmentalisation.

Antibodies↗