Biomedical subjects

R Spaventi

Publications and source records attributed to R Spaventi.

24 records · Page 2Linked to original sources

PubMed1990

Insulin and insulin-like growth factor I (IGF I) in early mouse embryogenesis.

Growth factors have an important role in the regulation of cell growth, division and differentiation. They are also involved in the regulation of embryonic growth and differentiation. Insulin and insulin-like growth factor I (IGF I) play an important part in these events in the later stages of embryogenesis, when organogenesis is completed. In this study, we are presenting evidence that insulin and IGF I are also secreted by embryonic tissues during the prepancreatic stage of mouse development. We found measurable amounts of insulin and IGF I in 8- to 12-day-old mouse embryos. We also showed that embryonic cells derived from 8-, 9- and 10-day-old mouse embryos secrete insulin, IGF I and/or related molecules. Furthermore, the same growth factors, when added to the culture of 9-day-old mouse embryonic cells, stimulate their proliferation. These results lead to the conclusion that insulin can stimulate the growth of embryonic cells during the period when pancreas is not yet formed, which is indirect evidence for a paracrine (or autocrine) type of action.

Animals↗

PubMed1989

Growth factors in human tumors.

Various human tumor tissues contain different growth factors. In some cases progression of tumors is paralleled by elevated levels of these substances in blood or in tumor tissue. There is evidence that these growth promoting peptides might stimulate tumor growth. The growth of most tumors was associated with insulin-like substances (MW 45,000). We isolated and purified a substance immunologically cross-reactive with insulin (SICRI) from human melanoma. We found the molecular weight of affinity purified SICRI to be approximately 120,000. Our in vitro experiments with human renal carcinoma cells and growth factors suggest an important role of these molecules in tumor progression.

Cell Division↗

PubMedDate not supplied

nm23-H1 gene expression in ovarian tumors--a potential tumor marker.

Ovarian carcinomas that have a distinctive natural history with early dissemination are particularly problematic. The aim of this immunohistochemical study was to assess whether the nm23-H1 gene product, which in some tumors shows inverse association with metastatic potential, could serve as a prognostic marker for ovarian carcinomas. The study, based on 73 benign and 54 malignant ovarian tumors, showed clear differences in the frequency of nm23-H1-positive samples, the intensity of staining and the histological localization of this protein. Differences were observed between normal ovary samples and benign lesions as well as between benign tumors and ovarian carcinomas and were highly significant. Furthermore, carcinomas that had detectable metastasis at the time of surgery were negative for nm23-H1 protein more frequently than those that did not. Although this is a prospective study in which collection of clinical data is ongoing, the results strongly suggest that nm23-H1 may serve as a potentially valuable marker for ovarian tumors.

Adenoma↗

PubMedDate not supplied

Prognostic significance of transforming growth factor alpha TGF-alpha) in human lung carcinoma: an immunohistochemical study.

Despite emerging data relating oncogene expression, growth factors and/or their receptors to the etiology of lung cancer, standard clinicopathological evaluation is still used for the diagnostic and prognostic purposes. Recent studies have shown that expression of some oncogenes and growth factors/receptors may be useful as markers in routine diagnostic and prognostic processes. For example, EGF/erb-B family of peptides may play a role in lung carcinogenesis. Similarly, expression of TGF-alpha mRNA and peptide has been shown to occur in various human lung carcinomas in vivo and in vitro. However, results concerning the role of TGF-alpha in lung carcinoma are conflicting and therefore its clinical value still remains obscure. To better evaluate the potential value of TGF-alpha in clinical application we have investigated the relationship between TGF-alpha expression in 51 lung carcinomas and 26 different clinical and clinicopathological parameters. The only significant correlation noted was between TGF-alpha and venous blood erythrocytes and eosinophils. This study suggests a relationship between metastasis and aggressive behavior of lung cancer. This data shows that TGF-alpha expression can not serve as an independent tumor marker for lung cancer.

Biomarkers, Tumor↗

PubMedDate not supplied

Immunohistochemical detection of TGF-alpha, EGF-R, c-erbB-2, c-H-ras, c-myc, estrogen and progesterone in benign and malignant human breast lesions: a concomitant expression.

The expression of transforming growth factor-alpha (TGF-alpha), epidermal growth factor receptor (EGF-R) and oncogenes c-erbB-2, c-H-ras, c-myc, as well as estrogen (ER) and progesterone (PR) receptors were studied immunohistochemically in the tissue of 21 benign and 58 malignant human breast lesions. Twenty nine (50%) of 58 carcinomas were positive for EGF-R and c-erbB-2 product, 55 (94.8%) for c-myc product, 9 (15.5%) for c-H-ras product and 17 (29%) for TGF-alpha. Eighteen of 58 (31%) carcinomas were estrogen receptor positive and 22 (38%) were positive for progesterone receptor. No correlation was found between expression of each investigated parameter and the clinical stage or degree of histological differentiation of the carcinomas. However, a significant positive correlation was observed between lymph node involvement and c-erbB-2 and EGF-R/c-erbB-2 positive tumors. A strong correlation was also observed between high levels of EGF-R and low levels of estrogen receptor. In 15 of 17 cases we found simultaneous expression of EGF-R and TGF-alpha. We also found interesting patterns in concomitant expression of the investigated parameters suggesting a possible cascade of events that occur in breast cancer cells.

Breast Diseases↗

PubMedDate not supplied

[Genetic basis of tumors of the colon].

Recent advances in understanding the genetic basis of malignant disease have been dominated by research in colorectal cancer. It has been postulated in previous studies that colorectal adenomas and cancer occur in several rare inherited syndromes and more commonly as sporadic cases. However, new evidence suggests that inherited susceptibility may also be important in a large fraction of so-called sporadic cases. These discoveries will, in very near future, inevitably lead to radical changes in the clinical management of this disease, particularly with the introduction of molecular diagnostic procedures, new chemoprevention protocols, and possibly gene therapy. This review discusses the current developments in colorectal cancer genetics which will be central to such changes.

Colorectal Neoplasms↗