Biomedical subjects

F Commo

Publications and source records attributed to F Commo.

7 recordsLinked to original sources

PubMed2004

Histopathological validation of the sentinel node concept in cervical cancer.

BACKGROUND: The sentinel node (SN) is defined as the first node in the lymphatic system that drains a tumor site. If the SN is not metastatic, then all other nodes should also be disease-free. We used serial sections and immunohistochemical (IHC) staining to examine both sentinel and non-sentinel nodes (non-SNs). MATERIALS AND METHODS: From July 2001 to March 2003, 18 patients (median age, 48 years) with cervical cancer (stage IA2, one patient; stage IB1, nine patients; stage IB2, three patients; stage IIA, three patients; and stage IIB, two patients) underwent a laparoscopic SN procedure based on a combined detection method, followed by complete laparoscopic pelvic lymphadenectomy. If the SN was free of metastasis by both hematoxylin and eosin (H&E) and IHC staining, all non-SNs were also examined by the combined staining method. RESULTS: A mean of 2.4 SNs (range 1-5) and 8 non-SNs (range 4-14) were excised per patient. Eight SNs (18.2%) from five patients (27.8%) were found to be metastatic at the final histological assessment, including two macrometastatic SNs, three micrometastatic SNs and isolated tumor cells in three SNs. In 13 patients, no metastatic SN involvement was detected by H&E and IHC staining. In these 13 patients, 106 non-SNs were examined by serial sectioning and IHC, and none was found to be metastatic. CONCLUSIONS: The SN procedure appears to reliably predict the metastatic status of the regional lymphatic basin in patients with cervical cancer.

Adenocarcinoma↗

PubMed2001

Telomerase activation cooperates with inactivation of p16 in early head and neck tumorigenesis.

Alteration of the p16/pRb pathway may cooperate with telomerase activation during cellular immortalization and tumour progression. We studied p16 expression status by immunohistochemistry and telomerase activity using the TRAP assay in 21 premalignant lesions of the head and neck epithelium as well as 27 squamous-cell carcinomas. We also examined expression of other components of the pathway (cyclin D1 and pRb) as well as presence of human papillomavirus genomes which can target these molecules. 4 of 9 mild dysplastic lesions (44%), 8 of 12 moderate/severe dysplastic lesions (67%), and 25 of 27 squamous-cell carcinomas (92%) demonstrated high telomerase activity (P = 0.009). There was a parallel increase with severity of lesions for the trend in proportions of cases demonstrating p16 inactivation or cyclin D1 overexpression (P = 0.02 and P = 0.01, respectively). For Ki67, a marker of cell proliferation, this trend was not significant (P = 0.08). Human papillomavirus infection was only found in 4 cases among the 48 samples tested (8.3%). In conclusion, progression of disease is accompanied by a parallel and continuous increase in telomerase activity and alterations in cell cycle regulators (p16, cyclin D1), as proposed by in vitro models.

Adult↗

PubMed2000

CFTR, MDR1, and MRP1 immunolocalization in normal human nasal respiratory mucosa.

CFTR (cystic fibrosis transmembrane conductance regulator), MDR1 (multidrug resistance), and MRP1 (multidrug resistance-associated protein), members of the ABC transporter superfamily, possess multiple functions, particularly Cl(-), anion, and glutathione conjugate transport and cell detoxification. They are also hypothesized to have a number of complementary functions. It is generally accepted that data obtained from nasal mucosa can be extrapolated to lower airway cell physiology. The aim of the present study was to investigate by immunohistochemistry the differential localization of CFTR, MDR1, and MRP1 in the normal mucosa of 10 human nasal turbinates. In ciliated epithelial cells, CFTR was inconstantly expressed at the apical cell surface, intense membranous labeling was observed for MDR1, and intense cytoplasmic labeling was observed for MRP1. In the glands, a higher level of expression was observed on serous cells, at the apical surface (for CFTR), on lateral membranes (for MDR1), and with an intracytoplasmic distribution (for MRP1). In conclusion, CFTR, MDR1 and MRP1 are expressed in the epithelium and glands of the nasal respiratory mucosa, but with different patterns of expression. These results suggest major roles for CFTR, MDR1, and MRP1 in serous glandular cells and a protective function for MDR1 and MRP1 in respiratory ciliated cells. (J Histochem Cytochem 48:1215-1222, 2000)

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

MDR1-Pgp 170 expression in human bronchus.

MDR1 P-glycoprotein (Pgp 170), a member of the adenosine triphosphate (ATP) binding cassette transporters, acts as an efflux pump for various hydrophobic agents, particularly for xenobiotics such as benzo(a)pyrene. It has also been shown to regulate cell-volume activated chloride channels. Pgp 170 could, therefore, be of particular importance in cellular mechanisms of defence in the airways and in the control of mucus layer composition. For these reasons, we evaluated the precise localization of Pgp 170 in human adult airways. Fresh non-neoplastic bronchial specimens were collected from 33 patients (26 smokers, four exsmokers and three nonsmokers) who underwent surgery for lung carcinoma. The presence of MDR1 messenger ribonucleic acid (mRNA) was demonstrated by reverse transcriptase chain reaction (RT-PCR) in bronchial epithelial cells collected by gentle scraping from either smokers, exsmokers or nonsmokers. Immunodetection of Pgp 170 using a panel of monoclonal antibodies (MRK16, JSB1, C219, C494) was performed either on cryostat or paraffin-embedded sections of histologically normal bronchial tissue. Pgp 170 was constantly detected with intense labelling at the apical surface of ciliated epithelial cells from the surface epithelium or ciliated collecting ducts, and on apical and lateral surfaces of serous cells from bronchial glands. No staining of mucus-secreting cells was observed. Pgp 170 was also demonstrated at the luminal surface of endothelial cells of bronchial capillaries. In conclusion, the expression of MDR1 P-glycoprotein in bronchial structures, particularly at the epithelial apical surface, suggests important roles for this transmembrane protein in human airways.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1996

[Effect of microwave pretreatment on the detection of Epstein-Barr virus EBER RNA's using in situ hybridization].

We have tested the influence of microwave pretreatment of tissue sections on in situ hybridization applied to the detection of Epstein-Barr virus-encoded small RNAs (EBER). To this end, different protocols have been tested on slides of 4 lymph node lymphomas: microwave pretreatment, proteinase K pretreatment, microwave followed by proteinase K and no pretreatment. To compare the sensitivity of each technique, several dilutions of oligoprobes were used. Hybrids have been detected by immunohistochemistry. The analysis of the nuclear stainings obtained shows an enhancement of the sensitivity in protocols using microwaves.

Endopeptidase K↗

PubMed1995

Enhancement of mRNA in situ hybridization signal by microwave heating.

BACKGROUND: Optimization of in situ hybridization protocols is of real interest when trying to detect small amounts of mRNA or when using low concentrations of probes. To enhance the hybridization signal, we have developed a modification of an in situ hybridization (ISH) protocol with radiolabeled cRNA probes. The detailed protocol of ISH used for paraffin sections is also described. EXPERIMENTAL DESIGN: In microwave (MW) heating, the tissue sections are heated in a sodium citrate buffer (0.01 M, pH 6). The effects of the pretreatment with MW were studied on kidneys and adrenals of young rats and on human pathologic samples using [35S]-RNA probes complementary to the mRNAs of some components of the renin angiotensin system. RESULTS: The heating pretreatment with the MW permitted us to obtain an enhancement of the hybridization signal, especially when using low doses of radioactive probes. This enhancement could be evaluated to 60 to 120% by computer-assisted quantification of the signal. Furthermore, the histologic structures and the staining with toluidine blue were not impaired by the heating treatment. CONCLUSIONS: The enhancing effect of the hybridization signal obtained using MW allows shorter autoradiographic exposure times and/or the use of lower concentrations of radioactive probes for the detection of mRNA or the detection of mRNA expressed at the threshold of detection with usual protocols.

Adrenal Glands↗

PubMed1995

Expression of p53 protein related to the presence of human papillomavirus infection in precancer lesions of the larynx.

The aim of this study was to gain some insight into the relationship of human papillomavirus (HPV) infection to p53 expression and to some pathological parameters in precancerous lesions of the larynx. Formalin-fixed paraffin-embedded tissue sections containing human laryngeal precancerous lesions were screened for p53 protein by immunohistochemistry with the monoclonal antibody DO7 and for the presence of HPV infection by polymerase chain reaction with consensus primers directed against the E6 gene. The presence of p53 protein was detected in 31 of 57 specimens (54.4%) including 7 of 9 cases with mild dysplasia (78%), in 4 of 9 cases with moderate dysplasia (44%), and in 15 of 23 cases with severe dysplasia (65%). Of 16 samples with keratotic benign squamous metaplasia, 5 were also p53 positive (31%). Of 6 samples that were HPV positive, all were of type 16. Interestingly, 3 of the 6 HPV-positive samples were p53 negative. There was 1 HPV-positive case with strong p53 staining and 2 HPV-positive cases with minimal p53 staining. The 2 HPV-positive cases with minimal p53 staining had mild dysplasia. The HPV-positive case with strong p53 staining displayed severe dysplasia. Of 23 cases that were both HPV and p53 negative, 11 presented with keratosis and no dysplasia, 5 with moderate dysplasia, and 7 with severe dysplasia. Our data indicate that nuclear accumulation of p53 protein, presumably resulting from p53 gene mutation, may occur in HPV-infected epithelial tissues. On the other hand, there are many precancer lesions, some exhibiting moderate or severe dysplasia, that are both HPV negative and p53 unreactive, suggesting that alterations of genes other than the E6 oncogene and the p53 tumor suppressor gene play a role in early laryngeal carcinogenesis.

Adult↗