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Biomedical subjects

G Flamini

Publications and source records attributed to G Flamini.

At least 37 records · Page 2Linked to original sources
PubMed1997

Immunohistochemical analysis of p53 protein in transplant recipients with Kaposi's sarcoma.

PURPOSE: Kaposi's sarcoma (KS) is a proliferative process of suspected viral aetiology associated with immune deficiency. In transplanted patients, lesions regress on discontinuation of immunosuppressive therapy. The purpose of this work was to analyse the expression of the p53 oncosuppressor gene product, a proliferation regulator overexpressed in both malignant and non-malignant conditions, with the aim of better qualifying KS proliferation characteristics. METHODS: We analysed p53 expression in a group of transplanted, cyclosporin A-treated, KS patients by immunohistochemistry, utilizing the DO-7 (with and without the antigen retrieval pretreatment), and the PAb 240 monoclonal anti-p53 antibodies, the latter of which is able to detect a mutated epitope, and evaluating staining intensity and localization, whether cytoplasmic or nuclear. RESULTS: Seventy five percent of KS lesions from transplanted patients presented both nuclear and cytoplasmic positive p53 immunostaining with DO-7 antibody, thus demonstrating a presumably functional inactivation; one case also presented immunoreactivity with the PAb 240 antibody. CONCLUSIONS: On the basis of the results obtained and in the presence of lesion regression upon immunosuppression withdrawal, it may be concluded that KS in transplanted patients can be considered a non-malignant proliferative process, and that the cytoplasmic expression of p53 may stand for a functional inactivation pattern.

Female↗
PubMed1996

Detection of oncogene mutation from neoplastic colonic cells exfoliated in feces.

PURPOSE: Best chances of a cure from colorectal cancer are obtained before metastatic spread. Lack of specific tests allowing early diagnosis of the tumor accounts for investigation of gene alterations involved in carcinogenesis by a noninvasive method. In the present study, K-ras codons 12 and 13 mutations were studied in neoplastic cells shed from the bowel into the stool and those contained in the tumor and normal mucosa. Moreover, healthy patients and a few others with precancerous conditions were examined. METHODS: Stool, tumor, and mucosa samples were taken from 25 patients with colorectal adenocarcinoma. Stool and mucosa samples were obtained from 11 healthy patients, and stool, pathologic bowel tissue, and normal mucosa samples were obtained from 3 patients with adenoma (1) or ulcerative colitis (2). Polymerase chain reaction amplification and restriction enzyme analysis were performed. RESULTS: K-ras codon 12 mutations were detected in both tumor and stool samples of 10 cancer patients, and no gene alterations were observed in 14 patients. In one patient with a tumor, a mutation was shown in only the tumor tissue. The agreement rate in tumor and stool analysis was 96 percent. A normal pattern of K-ras codons 12 and 13 was observed in the bowel mucosa. All stool and mucosa samples from healthy patients were not altered in K-ras. Agreement was registered between samples taken from patients with preneoplastic lesions. CONCLUSIONS: These preliminary findings show a high rate of accuracy in the investigation of K-ras alterations in the colorectal cells shed into the feces, suggesting that such an approach could be used to study other gene alterations and, prospectively, to identify early colorectal cancers.

Aged↗
PubMed1996

Prognostic significance of cytoplasmic p53 overexpression in colorectal cancer. An immunohistochemical analysis.

p53 overexpression was studied by immunohistochemistry in 96 consecutive colorectal cancer patients, subdividing positive specimens according to two staining patterns: cytoplasmic or nuclear. Forty-seven per cent of the cases were p53 positive, a significant correlation being found with Dukes' stage (P = 0.0036). A prevalence of nuclear staining was observed in Dukes' B and cytoplasmic in Dukes' D stages. After 36 months, 23% of the patients had a recurrence, and 45% were p53 positive, all Dukes' C-D stage with cytoplasmic staining. The Kaplan-Meier curve showed a significant correlation between p53 cytoplasmic staining and disease-free survival period (P = 0.002). With respect to disease-free survival, the Cox proportional hazard regression test, comparing p53 positivity with Dukes' stage, showed the latter to be the most significant variable. In our series of patients, advanced Dukes' stage tumours were localised in the right colon, where a higher percentage of p53 positivity (67% versus 40% of the left side), as well as a higher frequency of cytoplasmic staining was observed. In conclusion, from the data obtained, a strong correlation between p53 cytoplasmic staining and patient prognosis is clearly indicated.

Adult↗
PubMed1996

Immunohistochemical quantitation of 4-aminobiphenyl-DNA adducts and p53 nuclear overexpression in T1 bladder cancer of smokers and nonsmokers.

An immunoperoxidase method, using a monoclonal antibody which recognizes 4-aminobiphenyl (4-ABP)-DNA adducts, was developed for the detection and quantitation of DNA damage in bladder tissue and applied to stored paraffin blocks of transurethral resection specimens of 46 patients with T1 bladder cancer. Mean relative staining intensity for 4-ABP-DNA adducts was significantly higher in current smokers (275 +/- 81, n = 24) compared to nonsmokers (113 +/- 71, n = 22) (P < 0.0001). There was a linear relationship between mean levels of relative staining and number of cigarettes smoked with lower levels in the 1-19 cig/day group (205 +/- 30, n = 5), compared to the 20-40 (289 +/- 40, n = 7) and the >40 cig/day group (351 +/- 57, n = 3)(P < 0.001). Nuclear overexpression of p53, analyzed by immunoperoxidase staining, was observed in 27 (59%) of the 45 stage T1 tumors analyzed. There was a significant correlation between p53 overexpression and recurrence of disease (odds ratio = 12.3, P < 0.01). Nuclear staining of p53 was also correlated with smoking status, cig/day and 4-ABP-DNA adducts. This work demonstrates that the immunohistochemical method has sufficient sensitivity for detection of 4-ABP-DNA adducts in human bladder samples. The method has several advantages including small sample size, the possibility of retrospective analysis of stored paraffin blocks, the ability to analyze binding in specific cell types, and a relatively low cost.

Aged↗
PubMed1995

Expression of alpha 3 beta 1 integrin receptor and its ligands in human lung tumors.

Increasing experimental evidence demonstrates that malignant transformation is associated with changes in the repertoire of expression of the integrin family of molecules, which mediate cell-matrix and cell-cell interactions. We have analyzed immunohistochemically and immunochemically the expression of VLA-3 integrin and its known ligands, namely, laminin (LM), fibronectin (FN), collagen type IV (Coll IV), nicein (NIC), and entactin/nidogen (ENT), in lung tumors of various histological types. alpha 3 beta 1 was detectable in normal bronchial epithelium and along basement membranes of alveolar walls. In non-small cell lung carcinomas (NSCLC) the integrin was expressed in 82% of the cases, independently of histological type and degree of differentiation of the tumors. On the other hand, only 13% of the small cell lung carcinomas (SCLC) displayed a weak and heterogeneous distribution of the alpha 3 beta 1 complex. Our findings were confirmed immunochemically using long-term tumor cell lines. While the expression of both alpha 3 beta 1 and ligands LM, FN, Coll IV, and Ent correlated in NSCLC with the presence of basement membranes, FN was the only ligand detectable in the stroma of SCLCs. A selective loss of nicein in basement membranes was demonstrated in NSCLC indicating an impairment of expression of this glycoprotein following malignant transformation.

Adenocarcinoma↗
PubMed1995

Structure/activity relationship of some natural monoterpenes as acaricides against Psoroptes cuniculi.

The pharmacological activity of many essential oils on a large number of human and animal pathogens, as used in folk medicine, has been confirmed world-wide by several laboratory investigations. Unfortunately, the biological properties of essential oils can be extremely inconsistent because of the variability of their chemical composition. The acaricidal activities of some natural terpenoids, which are the main constitutents of several essential oils, were evaluated in vitro against the mange mite (Psoroptes cuniculi) of the rabbit, by direct contact and by inhalation. Because the test components represent different chemical classes (hydrocarbons, alcohols, and phenols, with free and esterified or etherified functional groups), it was also possible to discern in a preliminary fashion a correlation between chemical structure and acaricidal activity. The results obtained suggest that molecules possessing free alcoholic or phenolic groups showed the most potent acaricidal activity.

Animals↗
PubMed1994

Acaricidal agents of natural origin against Psoroptes cuniculi.

Lavandula angustifolia Miller essential oil and some of its main constituents, i.e. linalool, linalyl acetate, and camphor were tested in vitro for their bioactivities against Psoroptes cuniculi (Delafond, 1859), mite of the rabbit. The essential oil and linalool were found to have very powerful miticidal activities.

Acyclic Monoterpenes↗
PubMed1993

Flavonoids and a saponin from Spartium junceum.

Two new flavonoids, 5,8-dihydroxy-4'-methoxy-6,7-methylenedioxyisoflavone and carthamidin-7-O-alpha-L-rhamnopyranoside and a new triterpenoid saponin, 3 beta,16 beta,22 beta,24-tetrahydroxy-olean-12- ene-3-beta-yl-]beta-D-glucopyranosyl (1-->2)]-alpha-L-rhamnopyranoside (junceoside), were isolated from Spartium junceum. Their structures were elucidated by means of IR, UV, MS, 1H, 13C NMR, 13C NMR DEPT and 2D NMR experiments. Apigenin-7-O-beta-D-glucopyranoside and genistein-8-C-beta-D-glucopyranoside, never previously found in this plant, were also isolated.

Carbohydrate Sequence↗
PubMed1993

Composition and antimicrobial properties of essential oils of four Mediterranean Lamiaceae.

Essential oils from Satureja montana L., Rosmarinus officinalis L., Thymus vulgaris L., and Calamintha nepeta (L.) Savi, were chemically analysed and their antimicrobial and fungicide activities evaluated on the basis of their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). All four oils have a biotoxic effect, the most active being those from Calamintha and Thymus.

Anti-Bacterial Agents↗
PubMed1992

Vasoconstrictor activity of 8-O-acetylharpagide from Ajuga reptans.

The traditional therapeutic indications for the use of Ajuga reptans (Labiatae) have been investigated. The H2O-soluble part of a crude and partially purified MeOH extract and two isolated iridoids (8-O-acetylharpagide and harpagide), were tested for a biological activity on isolated smooth muscle preparations from guinea pig.

Animals↗
PubMed1991

Idiotypic replica of an anti-human tumour-associated antigen monoclonal antibody. DNA sequence comparison between Ab1 and Ab3.

2G-3 is an anti-anti-idiotypic MoAb (Ab3) obtained upon immunization with a monoclonal Ab2 (A3B10), which behaves as the 'internal image' of CaMBr1, a saccharide epitope defined by MoAb MBr1 (Ab1). CaMBr1 is expressed on glycoconjugates of the human mammary carcinoma cell line MCF-7 and on normal and neoplastic mammary gland epithelial cells. Ab1 and Ab3, although exhibiting, in many respects, superimposable paratopic and idiotopic specificities, show a non-identical fine immunoreactivity, since 2G-3 has a preferential reactivity with the saccharidic epitope mounted on glycoproteins, while MBr1 reacts with both glycoproteins and glycolipids. V-region sequence analysis has shown that: (i) the VK genes employed belong to different families (VK1 and VK10); (ii) the JK2 segment is shared by the two L chains (thus a high degree of homology is observed between VK CDR3s); (iii) the VH genes employed derive from the same family VHIIB/J558 (but show CDR homology only in CDR2); (iv) different JH region genes are employed. These data, together with the comparison of deduced secondary structure parameters, give further evidence for the possible production of similar combining sites using different VH and VL germ-line genes.

Amino Acid Sequence↗
PubMed1991

Bilateral bronchoalveolar lavage in progressive systemic sclerosis: interlobar variability, lymphocyte subpopulations, and functional correlations.

Bilateral bronchoalveolar lavage (BAL) was carried out in right middle and left upper lobes of 22 nonsmoking females suffering from progressive systemic sclerosis in order to assess interlobar differences and functional correlation of the BAL composition. The patients' age ranged from 20 to 66 years, and the mean disease duration was 10.4 years. The most frequent finding was a mild BAL lymphocytosis (right in 11 of 22 patients; left in 8 of 22), but eosinophilic (right in 11 of 22; left in 5 of 22 patients) and neutrophilic (right in 9 of 22 patients; left in 1 of 22) alveolitis was recognized as well. Differential counts suggestive of alveolitis limited to one of the lavaged lobes were demonstrated in about one fourth of the cases. Including increased cellularity among the criteria of pathological BAL fluid composition, 14% of the subjects showed bilateral BAL results within the normal range. OKT8-positive lymphocytes were significantly increased in 3 patients, but the mean values were not. Total lung capacity, vital capacity, and forced expiratory volume in 1 s correlated inversely with BAL neutrophil (p less than 0.05) and granulocytic (p less than 0.01) differential counts; the strongest, positive correlation was demonstrated regarding the lymphocyte/granulocyte ratios (p less than 0.0005). In conclusion, several patterns of alveolitis as well as a bilaterally normal BAL composition were found in our series; moreover, even if inhomogeneous alveolitis did occur, a single lavage performed in the right middle lobe correctly detected or excluded the presence of an alveolitis in 95% of our patients.

Adult↗
PubMed1989

Idiotypic replica of an anti-human tumor-associated antigen monoclonal antibody. Analysis of monoclonal Ab1 and Ab3 fine specificity.

CaMBr1 is a tissue-specific and tumor-associated saccharidic epitope, defined by mAb MBr1 (Ab1), expressed on glycoconjugates of the human mammary carcinoma cell line MCF-7 and of normal and neoplastic mammary epithelial cells. An anti-anti-idiotypic monoclonal Ab3, 2G-3, identifying a human breast tumor associated antigen, was raised by using as immunogen a mouse anti-idiotypic monoclonal Ab2, A3B10, which behaves as the internal image of CaMBr1. mAb 2G-3, as well as MBr1, defines a saccharidic epitope on glycoconjugates extracted from MCF-7 cells and shows MBr1-like reactivity on normal and neoplastic-tissues. Experimental evidence, however, suggests that the fine immunoreactivity of the two antibodies is not identical, because MBr1 has a preferential reactivity with glycolipids and 2G-3 with glycoproteins. We suggest that a possible biologic explanation for our findings could reside in the nature of the immunogens used to raise the two mAb (glycolipid vs protein "internal image").

Animals↗
PubMed1988

Chromatographic and electrophoretic studies of immune complexes in non-A, non-B hepatitis.

Immune complexes isolated from two patients with chronic non-A, non-B hepatitis, one patient with acute non-A, non-B hepatitis and one patient with juvenile rheumatoid arthritis were examined by means of a combined chromatographic and electrophoretic method. Both analyses showed the presence of complexes consisting of IgG, IgM, complement c1q factor and albumin; no antigen constituents were detected. The IgG-to-IgM ratio varied from 1:1 to 4:1, suggesting that one could be dealing with complexes of both IgG-IgM and IgG-IgG types. Moreover, the detectable presence of c1q factor might indicate that such complexes were capable of activating complement.

Antigen-Antibody Complex↗