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Biomedical subjects

S Pilotti

Publications and source records attributed to S Pilotti.

At least 163 records · Page 9Linked to original sources
PubMed1992

Comparison of Southern blot analysis with isotopic and nonisotopic in situ hybridization for the detection of human papillomavirus sequences in invasive carcinoma of the uterine cervix.

To compare the efficiency of hybridization methods for the detection of HPV genome, 22 cases of invasive squamous cell carcinoma of the uterine cervix were analyzed by Southern blot analysis and in situ hybridization carried out with 35S- and biotin-labeled probes. These cases contained from less than one to as many as 50 copies per cell of HPV 16 and 18 types. To increase the sensitivity of biotinylated probes, a silver enhancement procedure of the peroxidase reaction product was applied. Results showed that in situ hybridization performed with isotopic probes is as sensitive as Southern blot analysis and is more sensitive than that performed with biotin-labeled probe. However, the application of the silver enhancement procedure increases the percentage of HPV-positive cases from 27 to 50%.

Base Sequence↗
PubMed1992

Human papillomavirus genomes in male urethral cells.

Sixty-four samples of urethral cells from male sexual partners of women with genital human papillomavirus (HPV) infection were analyzed for the presence of HPV types 6, 11, 16, and 18 by polymerase chain reaction (PCR) followed by slot blot hybridization. Additional samples from 37 of these subjects were analyzed for the presence of viral cytopathic effects by conventional cytology. By PCR, HPV DNA was detected in 21% (14/64) of samples. By cytology, 16% (6/37) of the samples showed cellular changes consistent with HPV infection. Polymerase chain reaction and cytology results were concordant for presence and absence of HPV in 5 and 28 cases, respectively. Three additional HPV-positive cases were obtained with PCR in the cytologically negative samples. The cytologic abnormalities were found to be associated with the presence of both low-risk HPV types and meatal acetoreactivity. On the contrary, HPV DNA positivity by PCR was unrelated to viral type and peniscopic findings. Urethral HPV infection was detected by PCR in 30% of males with visible penile lesions and in 18% of those without. These results indicate that PCR analysis of urethral samples is a helpful adjunct to cytology for the detection of HPV DNA in absence of cytologic evidence of infection.

Base Sequence↗
PubMed1992

Overexpression of the c-MET/HGF receptor gene in human thyroid carcinomas.

The receptor for Hepatocyte Growth Factor is a transmembrane tyrosine kinase encoded by the c-MET oncogene. We have previously shown that the Met protein is expressed in several human epithelial tissues. The receptor is barely detectable, however, in normal thyroids and in specimens from patients affected by non-neoplastic thyroid diseases. Now we report that the expression of the Met/HGF receptor is increased a hundred fold in 22 out of 41 human carcinomas derived from the thyroid follicular epithelium. A comprehensive analysis of 15 cases showed that the overexpressing carcinomas belong to histotype variants correlated with negative prognosis and in all but one case there were evidences of locally advanced disease and/or distant metastases. The 11 benign adenomas and the 5 medullary carcinomas tested were negative. Western blot analysis with monoclonal antibodies directed against either the intracellular or the extracellular receptor domains failed to reveal major structural alterations. Southern blot analysis also demonstrated that the c-MET gene was not amplified nor rearranged. These data suggest a role for the overexpression of c-MET oncogene in the pathogenesis and progression of thyroid tumors derived from the follicular epithelium.

Adolescent↗
PubMed1992

DNA methylation of coding and non-coding regions of the human H-RAS gene in normal and tumor tissues.

To study a possible role of DNA methylation in the regulation of expression of the human H-RAS gene in vivo, 41 samples of different normal tissues and 33 tumors of various histotypes were analysed for DNA methylation. In a subset of normal tissues the RNA expression was also examined. The promoter region of the gene showed the features of a CpG island being CpG rich and unmethylated in all the normal tissues and tumors. The coding region displayed an intermediate level of methylation in the majority of normal and tumor tissues. Among the normal tissues only thymus DNA was found to be hypermethylated, while testes and sperm cells DNAs were hypomethylated. The 3' region was found to be completely methylated only in sperm cells and was never completely demethylated. The majority of the tissues showed an intermediate level of methylation, and a certain tissue specificity emerged by comparing tissues of the same and different histotypes. However, the overall methylation of both coding and 3' regions did not correlate with the levels of tissue-specific RNA expression. In heterozygous individuals, allelic methylation of the 3' region showed either perfectly balanced or slightly unbalanced methylation of the two alleles in normal tissues, while an allele-specific methylation was found in 5 out of 12 fresh tumor samples.

Alleles↗
PubMed1992

Estrogen and progesterone receptors in breast cancer. Immunohistochemical assay on scraping material.

In order to demonstrate the reliability of immunocytochemical results on cytologic specimens for receptor analysis, the expression of estrogen and progesterone receptors was investigated using immunohistochemistry on frozen sections and on scraping material from the same samples of 50 breast carcinomas. The level of agreement between the two procedures was evaluated by the kappa statistic, as was that between each immunohistochemical procedure and the dextran-coated-charcoal assay since the latter is still the assay employed most frequently for steroid receptor determination and is used for official reports. Statistical results revealed very good agreement regarding the estrogen receptor analysis, with kappa values of .910 and .952 for the comparison of the dextran-coated-charcoal assay with immunocytochemistry on frozen sections and on scrapes, respectively, and .950 for the comparison between the two immunocytochemical procedures. As to progesterone receptors, the kappa values were .795 and .712 for the comparison between the biochemical and immunocytochemical results and .915 for agreement evaluation between the two immunocytochemical procedures. The study showed that the scraping procedure is a valuable tool for the immunocytochemical assessment of steroid receptors in small mammary tumors; it yields representative cellular samples, thus permitting the investigation of heterogeneously distributed substances in tissues.

Adult↗
PubMed1991

Genital human papilloma virus infection in males. A clinico-pathologic study.

From March 1987 to December 1988, 402 male sexual partners of 317 women with human papilloma virus (HPV) infection of the lower genital tract and 85 with HPV-associated cervical and/or vulvar intraepithelial neoplasia (CIN and/or VIN) were submitted to clinical examination and peniscopy. The latter was performed at a 6-15 X magnification after a 3 min exposure to 5% acetic acid solution. Visible lesions were biopsied. Thirty-one patients had clinical evidence of HPV infection in the glans, penile shaft or urethra, and 222 had peniscopic evidence of subclinical aceto-white lesions. Of 31 patients with clinical lesions, 11 showed also aceto-white subclinical lesions. Of 253 peniscopically positive males, 237 were biopsied and 191 of these were histologically ascertained. Three patients had penile intraepithelial neoplasia, one with clinical appearance of a Buschke-Löwenstein tumor. The incidence of HPV infection in male sexual partners of women affected by HPV infection of the lower genital tract associated or not with intraepithelial neoplasia is lower than expected. However, clinically negative males should not be considered disease free; in fact, 12 patients, negative at the first examination, showed histological evidence of HPV infection at subsequent controls. Therefore, follow-up of at least 6 months should be allowed to identify HPV bearing males. The reported low frequency of HPV infection may be due to the fact that the males may harbour the virus in the urethra, prostate or seminal vesicles or penis without any clinical evidence of disease. Although research for HPV-DNA in intraurethral and penile scraping material might be useful for diagnosis, peniscopy with a 5% acetic acid application remains the clinical test for evaluating HPV infection in males. The importance of peniscopy should be viewed with respect to the prevention of infection or reinfection of the female sexual partners, in addition to the specific diagnostic purpose in male patients.

Adolescent↗
PubMed1991

Cytogenetic abnormalities and overexpression of receptors for growth factors in normal bronchial epithelium and tumor samples of lung cancer patients.

A cytogenetic analysis was performed on direct preparations and short-term cell cultures of lung tumor and normal bronchial epithelium of 19 patients carrying either a first or a second primary lung cancer. In 9 tumors (6 squamous cell carcinomas, 1 adenocarcinoma, 1 mucoepidermoid carcinoma, and 1 small cell lung carcinoma) successfully analyzed, pseudodiploid and hyperdiploid karyotypes were observed with a heterogeneous pattern of chromosome abnormalities but with a consistent involvement (5 cases) of the short or the long arm of chromosome 3. The normal bronchial epithelial cells had a normal karyotype in 11 patients, whereas in 6 patients clonal and nonclonal chromosomal abnormalities were observed. Involvement of chromosome 7 was present in 4 cases. In addition, overexpression of the growth factor receptors, epidermal growth factor receptor and HER-2/neu, was found in 9 of 18 tumors and in 6 of 13 bronchial epithelium samples. These findings suggest that early genetic lesions could be present in the normal bronchial epithelial cells that are the target of further complex and multiple genetic changes occurring during the pathogenesis of lung cancer.

Aged↗
PubMed1991

Argyrophilic carcinoma of the male breast. A neuroendocrine tumor containing predominantly chromogranin B (secretogranin I).

Argyrophilic tumors were diagnosed in 28 of 134 (20.8%) consecutive male patients who had a carcinoma of the breast removed between 1961 and 1990. Histologically, most argyrophilic tumors showed uniform cellularity and prevalent expansive growth. Ultrastructural observation disclosed the presence of electron-dense cored granules in the cytoplasm of the tumor cells. By immunocytochemistry, 17 of 28 argyrophilic tumors (60.7%) contained chromogranin B (secretogranin I)-immunoreactive cells, whereas chromogranin A was present in four of these 17 tumors only (14.2%). Immunoblotting studies showed chromogranin B immunoreactivity similar to that found in normal neuroendocrine cells. Despite these findings, which would argue for a distinct morphologic and immunochemical entity, no statistically significant differences between argyrophilic and common male breast carcinomas were found when a number of clinicopathologic features and relapse-free survival were considered.

Adult↗
PubMed1990

Diagnostic efficacy of physical examination, mammography, fine needle aspiration cytology (triple-test) in solid breast lumps: an analysis of 1708 consecutive cases.

The clinical-radiologic-cytologic triplet was used for diagnostic evaluation in 1708 women over 30 years old with a breast lump. All the lumps were subjected to surgery except for 258 cases in which clinical resolution took place within 1-2 months. Seven-hundred and ninety-three out of 1450 nodules removed were cancers. Sensitivity of the clinical, mammographic and cytologic examinations was 82%, 73% and 68%, respectively. It increased to 95% when they were associated. Specificity was 63%, 80% and 97%, respectively. The predictive value of positive results of the triple test was 100%. No patient with malignant cytology was subsequently shown to have benign disease. The systematic use of the triple test in solid breast lumps for the early detection of cancer is recommended as a routine procedure. However, participation of experienced radiologists and pathologists as well as physicians skilled in fine needle puncture is required.

Biopsy, Needle↗
PubMed1990

Relationships among tumor responsiveness, cell sensitivity, doxorubicin cellular pharmacokinetics and drug-induced DNA alterations in two human small-cell lung cancer xenografts.

In an attempt to understand the underlying cellular/biochemical factors of sensitivity/resistance in human small-cell lung cancer (SCLC), 2 SCLC tumor lines were compared with respect to tumor responsiveness to drug treatment, cell sensitivity, cellular doxorubicin accumulation, and DNA topoisomerase-II-mediated DNA cleavage. The tumor lines growing in nude mice with similar growth characteristics (doubling time around 10 days) were selected since one (POCI tumor) was found to be hypersensitive and the other (POSG tumor) resistant to doxorubicin treatment. The pattern of anti-tumor drug response of the doxorubicin-resistant tumor was atypical (i.e., non-adherent to the well-characterized multi-drug-resistant phenotype), since it responded to vincristine. The markedly different in vivo tumor response reflected the intrinsic cellular sensitivity to doxorubicin. No correlation was found between cellular drug accumulation and doxorubicin sensitivity following in vitro exposure to the drug. In agreement with this observation, the expression of mdr-I gene was undetectable in these tumors. Thus, in the POSG tumor, resistance to doxorubicin occurred without expression of the P-glycoprotein and reduction of cellular drug accumulation. In contrast, the extent of DNA cleavage produced by doxorubicin was markedly higher in the doxorubicin-hypersensitive than in the doxorubicin-resistant tumor. These results, taken together with previous observations in SCLC cell lines, support the important role of DNA topoisomerase-mediated effects in the sensitivity of SCLC to doxorubicin.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

Immunocytochemical localization and identification of members of the pancreatic polypeptide (PP)-fold family in human thyroid C cells and medullary carcinomas.

An increasing number of regulatory peptides not coded by the calcitonin genes are known to occur in the thyroid C cells. We have now carried out light and electron microscopic immunocytochemical analyses on specimens of normal human thyroids and medullary carcinomas to establish the occurrence of members of the PP-PYY-NPY family in the C cell system. By means of site-directed immunocytochemistry we provide the first evidence that a molecule closely related to proNPY is present in normal and pathologic C cells, and is co-stored with calcitonin in the cytoplasmic dense-core granules. Preliminary observations also suggest that high levels of expression of NPY-gene products help to define a subset of tumours with a less aggressive behaviour.

Calcitonin↗
PubMed1990

t(11;22) in three cases of peripheral neuroepithelioma.

Short-term cultures of three cases of peripheral neuroepitheliomas were studied using G-banding technique. A t(11;22)(q24;q12) was recognized in all three tumors. The results strengthen the hypothesis of a common histogenesis for neuroepithelioma, Ewing's sarcoma, and the Askin tumor.

Adolescent↗
PubMed1990

Immunocytochemical localization and identification of prosomatostatin gene products in medullary carcinoma of human thyroid gland.

Thirty-three cases of histologically proven calcitonin-positive medullary thyroid carcinoma were studied immunocytochemically for the occurrence of prosomatostatin-related peptides. Positive cells, identified with a panel of antisera raised against four different regions of the prosomatostatin molecule, were found in 100% of the tumors. Most but not all somatostatin-positive cells were also immunoreactive for calcitonin. Notably, seven patients harboring somatostatin-rich tumors revealed a more favorable clinical course. The results (1) indicate that somatostatin production is a universal concomitant of thyroid medullary carcinoma, (2) suggest that these cells are likely to produce a somatostatin precursor molecule similar to mammalian prosomatostatin, and (3) imply that somatostatin-reactive cells may have as yet unknown roles in these tumors, possibly in the realm of paracrine and autocrine regulation of cell growth.

Adolescent↗
PubMed1990

cis-platinum/vinblastine/bleomycin combination chemotherapy in advanced or recurrent granulosa cell tumors of the ovary.

Seven consecutive patients with advanced/recurrent granulosa cell tumors were treated with PVB (cis-platinum, 20 mg/m2, Days 1-5; vinblastine, 6 mg/m2, Days 1 and 2; and bleomycin, 18 mg/m2, Days 2, 9, and 16). The median age at the start of PVB treatment was 53 years (15-57); three patients had stage III disease and four presented with abdominal recurrences. Prior to PVB, all but one patient underwent surgical treatment, and in six patients gross residual disease was documented. No patient received prior chemotherapy or radiotherapy. The median number of PVB cycles was 5. Three complete (one pathologically documented) and one partial response were observed, for an over-all response rate of 66%. Two complete responders were alive without evidence of disease 7 and 26 months from the start of treatment; the remaining patient relapsed at 15 months. Two patients progressed during treatment, and one died because of sepsis in agranulocytosis. Signs of peripheral neurotoxicity were documented in three patients. The present data confirm the therapeutic activity of the PVB regimen in advanced/recurrent granulosa cell tumors, but the cost/benefit ratio should be clearly assessed.

Adolescent↗
PubMed1990

Vulvar carcinomas: search for sequences homologous to human papillomavirus and herpes simplex virus DNA.

Ten cases of intraepithelial carcinoma, five with Bowenoid features and five with early invasion, and ten cases of invasive vulvar carcinoma were examined by in situ hybridization and Southern blot analysis using DNA probes for human papillomavirus (HPV) types 6, 11, 16, 18 and 31. HPV DNA was detected in 90% of the intraepithelial cases and in 10% of the invasive cases. All positive cases showed the presence of DNA of HPV type 16. The cases with intraepithelial lesions revealed a strong correlation between the presence of HPV type 16 DNA, cigarette smoking habit, other potential cofactors such as herpes simplex (HSV) DNA sequences and the use of contraceptive drugs, and clinicopathologic features of Bowen's type in situ squamous cell carcinoma. Similar associations were not observed among the cases with invasive disease. While HPV-16 is associated with differentiated Bowenoid type vulvar intraepithelial neoplasia, which appears to be the most common form of early carcinoma of the vulva, the same association was not seen with respect to advanced vulvar invasive squamous cell carcinoma.

Base Sequence↗
PubMed1989

In vivo and in vitro growth of SCLC cells derived from biopsies.

In order to increase the availability of SCLC cells derived from biopsies, in vivo and in vitro growth methods were investigated. The cells grown in both conditions were periodically monitored for reactivity with 2 monoclonal antibodies (MAbs): MLuC1 directed against SCLC cells and IM1 which recognizes the class II antigen on activated lymphocytes and macrophages. About 50% of the 28 analyzed SCLC specimens were found to proliferate in one or both systems. The in vitro-grown cells exhibited the same heterogeneity found in the original cell suspensions and moreover, in some cases only normal cells were recovered after several in vitro passages. From the subcutaneous transplanted tumors a large number of MLuC1-positive tumor cells could easily be recovered, thus indicating the validity of the in vivo methodology. The MBr1 MAb, directed against an epithelial antigen, was found to react with about 50% of the 26 tested tumors, mainly those which demonstrated in vivo and/or in vitro growth capacity. These data suggest that only some tumors, presumably with peculiar biological characteristics, can efficiently grow in these artificial systems.

Adult↗
PubMed1989

Relationship between CaMBr1 expression and tumor progression in small cell lung carcinomas.

In order to study the possible relationship between antigenic phenotype and tumor progression, 63 small cell lung carcinomas (SCLC) biopsies derived from primary or metastatic tumors were tested by immunofluorescence and immunoperoxidase techniques with an anti-carcinoma monoclonal antibody designated MBr1. Primary tumors were found to be less reactive with MBr1 than the local and distant metastatic lesions (57% versus 75% and 89% positivity respectively). A life table analysis on the tested cases indicated an inverse association between the expression of the marker recognized by the MBr1 MAb (CaMBr1) and overall survival (p less than 0.01): patients with MBr1-positive tumors showed a shorter survival time in comparison to patients whose tumors did not express the marker. The same correlation between survival and CaMBr1 expression was found even when only the 31 cases of early stage disease patients were considered (p less than 0.05). Different tumor aggressiveness or resistance to therapy of MBr1-positive tumors could be responsible for the shorter survival time of the patients.

Antibodies, Monoclonal↗