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Biomedical subjects

V Natoli

Publications and source records attributed to V Natoli.

At least 19 recordsLinked to original sources

[Evaluation of two rapid tests for the determination of microalbuminuria and the urinary albumin/creatinine ratio].

OBJECTIVE: Microalbuminuria screening is justified on the grounds of its cost-benefit ratio in patients at risk of kidney damage while the process is still reversible. The aim of the present study was to evaluate the DCA 2000 analyser and the Clinitek 50 system (Bayer), which simultaneously measure urinary albumin and creatinine levels to adopt them as rapid methods for microalbuminuria detection. METHODS: One hundred twenty-seven urine samples from pediatric patients with various disorders were assessed. Albumin, creatinine, and the albumin/creatinine ratio were determined using the DCA 2000 analyzer and the Clinitek 50 system, which were compared against the usual reference laboratory methods. RESULTS: The correlation coefficient of nephelometric values vs the DCA 2000 analyzer was 0.914 for albumin, 0.970 for creatinine and 0.839 for the albumin/creatinine ratio. At an albumin cut-off concentration of 30 mg/l, the sensitivity, specificity, positive predictive value and negative predictive value were 100 %, 93 %, 84 % and 100 % for the DCA 2000 analyzer and 91.7 %, 86 %, 55 % and 98 % for the Clinitek 50 system. ROC curve analysis showed that the DCA 2000 system was more effective than the Clinitek 50 in microalbuminuria screening. CONCLUSIONS: The data obtained with the DCA 2000 system showed close agreement with those obtained with reference laboratory methods. The immediate availability of results is a great advantage in clinical practice. The Clinitek-Microalbumin dipstick system is a semiquantitative method that is easy to use, low in cost, simple and useful for screening, but it is less reliable as a follow-up method.

Adolescent↗

Effect of natural beta-interferon on cell proliferation and steroid receptor level in human breast cancer cells.

The effect of natural beta-interferon (beta-IFN) on cell proliferation and steroid receptor level was investigated in CG-5 human breast cancer cell line. beta-interferon determines an appreciable diminution of cell growth, at concentrations ranging from 100 to 1000 IU/ml, which is enhanced when serum content of the culture medium is lowered. Low concentrations of beta-IFN (10-100 IU/ml) produce, after a 5-day treatment, an increase in estrogen receptors (ER) and progesterone receptors (PR). No variation of ER and PR levels is observed when beta-IFN is added directly to the cell homogenate before the assay. Our data suggest that beta-IFN could affect hormone sensitivity through a modification of ER and PR in neoplastic mammary cells.

Breast Neoplasms↗

Estrogen responsive creatine kinase in human breast cancer cells.

The brain type (BB) isoenzyme of creatine kinase (CK) is a very sensitive marker of estrogen action in rat uterus and in experimental mammary tumors. In order to detect useful markers for estrogen dependent human breast cancer cell proliferation we measured CK levels and isoenzyme composition in the CG5 cells, an estrogen supersensitive variant of the MCF-7 human breast cancer cell line. Under basal conditions, CK-BB accounted for 10%-15% of total enzymatic activity, while the MM isoenzyme represented the overwhelming component. In cells cultured in the presence of 5% charcoal-treated fetal calf serum, physiological concentrations (0.1-1 nM) of estradiol increased CK-BB levels in a dose- and time-related fashion. The effect was specific for estrogens and was prevented by antiestrogens. Our results show that CK-BB is estrogen regulated in the CG5 cells and suggest a possible role for this enzyme as an additional marker of the hormonal responsiveness of breast cancer.

Breast Neoplasms↗

A monoclonal antibody (AB/3) reactive with human breast cancer.

Monoclonal antibody AB/3 was produced from a fusion of spleen cells of a human breast cancer cell-primed BALB/c mouse with the murine myeloma cell line P3-NS1-Ag4-1. The antibody reacted strongly with the plasma membrane of human breast cancer cells. Tissue sections of both malignant and benign human mammary carcinomas and tumors of non-breast origin as well as apparently normal tissues were tested with immunoperoxidase. Ninety-six of 124 (77%) primary human breast cancers, 12 of 14 (86%) metastatic breast lesions, and 12 of 44 (27%) benign breast lesions reacted positively. Little or no appreciable reactivity was observed with apparently normal human tissues and carcinomas of non-breast origin, with the exception of colon carcinoma. Antibody AB/3 did not immunoprecipitate any identifiable protein from radiolabeled extracts of the immunizing cell line.

Animals↗

Estrogen stimulates cell proliferation and the increase of a 52,000 dalton glycoprotein in human breast cancer cells.

In an estrogen supersensitive variant of the MCF-7 cell line, CG-5, estrogen was found to stimulate the labelling of a glycoprotein released into the culture medium which has the same electrophoretic migration pattern as that previously reported in MCF-7 cells (Biochem. Biophys. Res. Commun., 90: 410-416, 1979). To test the possibility that the 52 K is a marker of estrogen-dependent breast cancer cell proliferation, we have correlated the effect of estrogen and antiestrogen on protein labelling and cell proliferation under different experimental conditions. In cells cultured in the presence of 5% charcoal-treated fetal calf serum, physiological concentrations (0.1-1 nM) of estradiol stimulated in a dose- and time-related fashion both 52 K labelling and cell proliferation. However at high concentrations (10-100 nM) estrogen decreased 52 K labelling while it still stimulated cell proliferation. Concentrations of the tamoxifen derivative, 4-hydroxytamoxifen, which effectively prevented estrogen-stimulated cell proliferation also blocked estrogen-stimulated increase of 52 K labelling. Time-course experiments suggest that the estrogen-stimulated increase of 52 K labelling (detectable after 22 h of hormone exposure) precedes the effect of cell proliferation (detectable after 3 days of hormone exposure). In cells cultured under serum-free conditions there was no effect of estradiol at any of the concentrations and times used on either 52 K labelling or cell proliferation.

Breast Neoplasms↗

Two new estrogen-supersensitive variants of the MCF-7 human breast cancer cell line.

Two new estrogen-sensitive variants of MCF-7 human breast cancer cells, CG-4 and CG-5, are described in this report. These cells were derived from a casual contamination by MCF-7 cells of primary cultures from a human adenocarcinoma of the breast and a pleural effusion of a patient with advanced breast cancer, respectively. Careful characterization of these variants revealed chromosomal properties highly similar to and alloenzyme phenotypes identical to those of MCF-7 cells which were simultaneously cultured in the laboratory. MCF-7, CG-4 and CG-5 cells were tested for estrogen responsiveness under identical growth conditions, that is in the presence of culture medium supplemented with 5% charcoal-treated serum. While the number of MCF-7 cells increases by about 40% over the controls in the presence of physiological concentrations of estradiol, the number of CG-4 cells doubles and the number of CG-5 cells triples. All these cell lines have approximately the same number of estrogen, androgen, glucocorticoid, and progesterone receptor sites/cell. Since several difficulties arise in demonstrating the estrogen responsive growth stimulation of currently available human breast cancer cells, these two new variants, characterized by a high and reproducible estrogen responsiveness, afford a new model for studying the mechanisms by which estrogen regulates cell proliferation. The problems related to the careful characterization of every established cell line are discussed.

Adenocarcinoma↗

Presence and steroid inducibility of glutamine synthetase in human leukemic cells.

Glutamine synthetase (EC 6.3.1.2; GS) is present in lymphoblasts from patients with acute lymphoblastic leukemia (ALL) as well as in normal peripheral blood lymphocytes. In 16 out of 20 ALL patients studied exposure of the cells to physiological concentrations of dexamethasone in vitro increased enzyme activity above the control levels. The increase was specific for glucocorticoid receptor ligands. A direct correlation was found between the magnitude of glucocorticoid-mediated increase of GS activity and the cellular levels of specific glucocorticoid receptors assayed in the same cell specimen. Moreover, the basal levels of the enzyme measured in cells prior to exposure to dexamethasone correlated negatively with receptor density. It is suggested that the presence of steroid-inducible GS in ALL cells may prove to be a marker for functional receptor sites.

Enzyme Induction↗

Steroid-induced proteins in human endometrium.

The synthesis of soluble proteins in human endometria at various phases of menstrual cycle was evaluated by polyacrylamide gel electrophoresis of [35S]methionine-labeled proteins. Densitometric analysis of the gels revealed alterations in the rate of synthesis of single protein bands throughout the cycle. Administration of conjugated estrogens (Premarin) to women undergoing hysterectomy, or exposure, in vitro, of the endometrial tissue to 17 beta-estradiol produced an increased incorporation of [35S]methionine into a specific protein which migrated on SDS-polyacrylamide gels at a molecular weight of about 55 000. Induction of this protein was observed only in those endometria showing a secretory histological appearance. The protein was resolved into at least 2 different spots in two-dimensional gel electrophoresis. An increase in the rate of synthesis of another endometrial protein with an apparent molecular weight of 51 000 was observed in tissues exposed in vitro to medroxyprogesterone acetate. These steroid-induced proteins may be a useful marker for studying hormone action in both normal and neoplastic endometria.

Electrophoresis, Polyacrylamide Gel↗