Search PubMed⌕ Search

Biomedical subjects

E Brambilla

Publications and source records attributed to E Brambilla.

At least 145 records · Page 8Linked to original sources
PubMed1996

Apoptosis-related factors p53, Bcl2, and Bax in neuroendocrine lung tumors.

Neuroendocrine (NE) lung tumors comprise four classes of progressive aggressiveness for which proliferation and apoptosis rates could both contribute to their distinctive behavior. As p53 mutations may favor escape from apoptosis through changes in Bcl2-Bax expression balance, which are survival and apoptotic genes, respectively, we studied 121 NE lung tumors (16 typical carcinoids (TC), 5 atypical carcinoids (AC), 29 large-cell NE carcinomas (LCNECs), and 71 small-cell lung carcinomas (SCLCs) using immunohistochemistry. We quantified apoptosis by terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) in 31 of these cases. There was a significant increase of p53 mutant immunophenotype (defined as immunoreactivity with at least two antibodies for at least 20% of tumor cells) between atypical/typical carcinoids group and the LCNEC/SCLC group (P = 0.0003). There was an inverse correlation (P < 0.0001) between the scores of Bax and Bcl2 expression in individual tumors and a significant inversion of the Bcl2. Bax ratio between low-grade (typical and atypical carcinoids) and high-grade (LCNECs and SCLCs) tumors with a predominant Bax expression in the first group and predominant Bcl2 expression in the second. Whereas carcinoids had variable apoptotic indexes, LCNECs had high indexes (1.3 to 6.8%), Bcl2 overexpression, Bax down-regulation, and Bcl2.Bax ratio > 1 correlated with lower apoptotic index in both LCNEC and the pool of LCNECs and SCLCs (P < 0.05) and a lower survival rate in the group of atypical and typical carcinoids and LCNECs (P < 0.002). The highest levels of Bcl2 expression and Bcl2.Bax ratios were associated with p53 mutant immunophenotype (P = 0.02). Our results suggest that aggressiveness in NE lung tumors could be linked, in addition to proliferation, to apoptosis-related factors.

Apoptosis↗
PubMed1996

An electron microscopy study into the mechanism of gene transfer with lipopolyamines.

Cationic amphiphiles have been shown to mediate gene transfer to eukaryotic cells, although the nature and fate of the lipid-DNA complexes is still a matter of debate. Negative staining transmission electron microscopy (TEM) of the complexes in physiological medium, as well as thin-section TEM of transfected cells has been used to visualize the particles and the possible pathways leading to transgene expression. Lipopolyamines form a network of tubular micelles into which plasmid DNA is intertwined and condensed; the cationic particles contain hundreds of plasmid molecules and are heterogeneous with respect to size (0.1-0.5 microgram) and shape. Adherent cells (293M, 3T3, MRC5, primary leptomeningeal cells) take them up readily within minutes by spontaneous endocytosis. Among suspension cells, lymphocytes only incidentally show cytoplasmic inclusions and monocytes degrade the particles by phagocytosis. The marked decrease in transfection efficiency generally observed between adherent and nonadherent cells is thus due to reduce cell binding. This suggests that cationic particles bind to membrane components responsible for Ca2+-mediated cell anchoring to the extracellular matrix. Cation/anion-mediated endocytosis leads to endosomes that are entirely filled with the particles. Consequently, two escape mechanisms may operate: disruption of the lamellar envelope in close contact with tubular micelles, and endosome buffering by the lipopolyamine in response to proton entry, leading to osmotic swelling and endosome rupture. Even for moderately transfected MRC5 cells, 10(2)-10(3) particles are found either free or in cytoplasmic vacuoles 24 h after transfection, highlighting a very inefficient nuclear translocation process. Such high numbers are also the clue to the small concentration window between transfection and cytotoxicity that is often observed with nonviral vectors. Nuclear particle inclusions are sometimes seen, yet it is unclear whether plasmid uncoating (before expression) takes place by anion exchange in the cytoplasm or in the nucleus. The still lower efficiency of free plasmid translocation to the nucleus suggests an active role for the cationic lipid during this step. Although the last stages of the transfection mechanism remain unclear, the present work shows that the major barrier which hampers in vitro gene delivery with cationic vectors is nuclear translocation (and cell entry for nonadherent cells), providing precise targets for the design of improved nonviral vectors.

3T3 Cells↗
PubMed1995

Mucinous cystadenoma of the lung.

BACKGROUND: Mucinous cystadenoma is an unusual pulmonary tumor that must be distinguished from mucinous cystic carcinoma and mucinous cystic tumors of borderline malignancy. METHODS: This study of two cases was performed to characterize mucinous cystadenoma clinically and immunohistochemically, using proliferation markers (proliferating cell nuclear antigen [PCNA], MIB1) and carcinoembryonic antigen expression. RESULTS: Pathologic examination in each instance showed unilocular cysts containing abundant clear mucus. The cysts were lined by tall mucinous epithelium, with absence of cytologic atypia and invasive growth. Proliferation markers using immunohistochemical methods showed less than 10% and 5% of labeled nuclei, respectively. Carcinoembryonic antigen immunostaining in both cases was negative. Patients remained free from recurrence for at least 2 years after surgery. CONCLUSIONS: Mucinous cystadenoma of the lung appears to be a benign neoplasm because of its clinical course and immunohistochemical low expression of proliferation markers such as PCNA and MIB1.

Adult↗
PubMed1995

Contribution of apoptosis to the phenotypic changes of adrenocortical cells in primary culture.

The aim of this study was to evaluate the occurrence and physiological consequences of apoptosis in primary cultures of bovine adrenocortical cells (of fasciculata-reticularis origin). Under ACTH-free culture conditions, we observed apoptotic cells in the cell layer and the accumulation of apoptotic bodies in the culture medium. These were hardly detectable in ACTH-supplemented cultures. Under ACTH-free conditions, the DNA content of apoptotic bodies collected over 48 h represented up to 10-15% of that of the cell layer at the onset of the culture (as compared to 3% in ACTH-supplemented cultures). Past the fourth day of culture in the absence of ACTh, most cells lacked several markers of their originating fasciculata-reticularis phenotype and progressively evolved to an undifferentiated phenotype. The vast majority of the apoptotic bodies released during the first 4 days of culture were immunoreactive for P450 17 alpha. Inversely, during the same period of time, the proliferating cells (PCNA-positive) did not appear to express P450 17 alpha. Therefore, apoptosis could contribute, together with dedifferentiation, to the phenotype shift observed in ACTH-depleted cultures of adrenal fasciculata-reticularis cells. These observations also characterize this endocrine cell system as an in vitro model for the study of hormone-repressed apoptosis.

Adrenal Cortex↗
PubMed1995

Interferon-gamma induces T lymphocyte proliferation in multiple sclerosis via a Ca(2+)-dependent mechanism.

The intracellular mechanisms underlying T lymphocyte activation leading to demyelination in multiple sclerosis (MS) have not yet been clarified. We have recently reported that interferon (IFN)-gamma activates a novel trans-plasmalemma Ca2+ influx on T lymphocytes (mainly CD4+) from patients with MS which induces intracellular Ca2+ ([Ca2+]i) elevation. Since Ca2+ is an essential second messenger in regulating transcription of T lymphocyte activation genes, we have evaluated how [Ca2+]i elevation due to the activity of this particular influx affects T lymphocyte proliferative behaviour in 12 influx-positive relapsing-remitting MS (RR-MS) patients. Fourteen influx-negative RR-MS patients and 14 healthy donors were used as controls. In lymphocytes from healthy controls, a significant correlation (r = 0.62; P < 0.001) was found between [Ca2+]i levels and proliferation rate after phytohemagglutinin (PHA) stimulation. Sustained proliferation was induced in T lymphocytes by > or = 10 micrograms/ml of PHA, a dose leading to a [Ca2+]i increase of at least 45% over basal level. Similar [Ca2+]i elevations were obtained when > or = 10 micrograms/ml of PHA were used on cells from RR-MS patients. However, T lymphocytes from RR-MS patients, but not from healthy donors, proliferated also in response to 1 micrograms/ml of PHA, indicating a state of preactivation. Moreover, 1 microgram/ml of PHA used in combination with suboptimal doses of IFN-gamma (5 UI/ml) doubled the proliferation rate of influx-positive MS cells, but not influx-negative MS cells or cells from healthy donors compared to the values obtained using PHA alone (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Rapidly alternating combination of cisplatin-based chemotherapy and hyperfractionated accelerated radiotherapy in split course for stage IIIA and stage IIIB non-small cell lung cancer: results of a phase I-II study by the GOTHA group. Group d'Oncologie Thoracique des Régions Alpines.

The prognosis of stage III non-small cell lung cancer (NSCLC) can be improved by a combination of radiotherapy (RT) and chemotherapy (CT). In this study, the GOTHA group evaluated the feasibility, tolerance, tumour response, pattern of failure and effect on survival of a combination alternating accelerated hyperfractionated (AH) RT and CT in patients with tumour stage III NSCLC. 65 patients received 3 cycles of cisplatin 60 mg/m2 and mitomycin C 8 mg/m2 on day 1, and vindesin 3 mg/m2 on days 1 and 8 in weeks 1-2, 5-6 and 9-10, alternating with AHRT, 2 daily 1.5 Gy fractions, 5 days/week, in weeks 2-3 (30 Gy) and weeks 6-7 (33 Gy). The dose actually delivered was > 98% for RT, and 85-100% for CT. Mean duration before last CT cycle was 9.5 weeks. Toxic effects were leucopenia, nausea and vomiting, mucositis, diarrhoea, alopecia and peripheral neuropathy. 1 patient died of bronchial haemorrhage at the end of RT. 1 of 5 patients, who underwent secondary pulmonary resections, died of acute respiratory distress syndrome. Evaluation of tumour response was hampered by lung condensations in radiation fields. Some long-term survivors had an initial tumour response assessed as partial response or no change. First failures were more frequent outside (34) than within (21) radiation fields. The median survival was 15.7 months and the 5 year survival rate was 15% (95% CI = 6-26%). 1 patient died of bladder cancer and another of myocardial infarction. Alternating CT and AHRT, as used in this study, were well tolerated and allowed full dose delivery within less than 12 weeks. Initial response was not predictive of survival. The survival curve is encouraging and the 5 year survival is superior to the 5% generally observed with conventionally fractionated radiotherapy.

Adult↗
PubMed1995

Differential c-myc, c-jun, c-raf and p53 expression in squamous cell carcinoma of the head and neck: implication in drug and radioresistance.

The expression of oncogenes c-myc, c-jun and c-raf and tumour suppressor gene p53 was assessed by northern blot analysis of 42 tumours and p53 protein expression by immunohistochemistry on paraffin-embedded sections from 36 specimens of squamous cell carcinoma of the head and neck (SCCHN) obtained before therapy. Of the 42 tumours, 89, 100 and 100% expressed c-myc, c-jun and c-raf oncogenes, respectively. These oncogene expressions did not correlate with sex, age or clinical stage of the disease. However, an association was found between low c-myc expression (P = 0.0001) and high c-jun expression (P = 0.0001) and absence of tumoral response to neoadjuvant chemotherapy. On the other hand, c-raf overexpression was observed in patients resistant to radiation therapy (P = 0.0494). Forty-two per cent of the tumours showed p53 protein overexpression, which did not correlate with any clinical parameter. This p53 protein overexpression was associated with high p53 mRNA levels (REL) (P = 0.0223). A correlation was found between increased c-myc RNA expression and lack of p53 protein expression (P = 0.0407). In addition, a lack of p53 protein expression was indicative of tumour relapse (P = 0.05). None of these biological parameters were associated with disease-free survival (Cox-Mantel test). In conclusion, the overexpression of c-myc, c-jun and c-raf may be independently associated to tumoral response to chemotherapy or radiotherapy, or to tumour relapse, but fail to predict long-term survival.

Adult↗
PubMed1995

Coexistence of plasma cell granulomas of lung and central nervous system.

A rare case of concurrent plasma cell granulomas (PCG) of the lung and the central nervous system (CNS) is reported. A 30-year-old man was presented with recurrent left headaches lasting for two years. Computerized tomographic (CT) scan and magnetic resonance imaging (MRI) of the head disclosed a process extending from the lateral aspect of the left cavernous sinus to the tentorium cerebelli and the infratemporal fossa through the foramen ovale. At the same time, chest-X ray and CT scan showed three symptomless masses of the pulmonary right lower lobe. Histological examination of cerebral samples and of one of the pulmonary nodules revealed the presence of a fibrous tissue containing numerous lymphocytes and plasma cells as well as remnants of vascular and respiratory structures. Immunohistochemical study proved these cells to be polyclonal. Ultrastructural analysis confirmed the presence of lymphoid cells and failed to disclose any argument for meningioma or histiocytosis X. The differential diagnostic problems of PCG are discussed as well as considerations about clinicopathological features, histogenesis and pathogenesis of inflammatory pseudotumours (IPT).

Adult↗
PubMed1995

Immunohistochemical detection of p53 protein in preneoplastic lesions and squamous cell carcinoma of the head and neck.

Alterations in the p53 tumor suppressor gene are the most frequent genetic abnormalities in human cancers. The p53 protein is present in normal cells, and is assumed to induce G1 arrest or apoptosis in the presence of DNA lesion. The mutant protein lacks this property. Squamous cell carcinomas of the head and neck (SCCHN) are related to carcinogens in tobacco and alcohol, and provide a good model of multiple-step carcinogenesis in association with DNA damage and p53-related tumorigenesis. Stabilization of the mutant p53 protein allows immunohistochemical analyses (IHC) to be routinely used to demonstrate the mutant p53 protein in tissue samples, whereas normal p53 protein is undetectable. Ninety-nine squamous cell carcinomas, 8 in situ carcinomas, 31 preneoplastic lesions and 79 normal carcinogen-exposed mucosas of the head and neck from a total of 107 patients were examined for the expression of p53 tumor suppressor gene protein. Samples were collected before treatment, and stained with p53 specific mono- and polyclonal antibodies (DO-7, Pab 1801 and 240, CM1) using an indirect immunoperoxidase technique. Proliferating cell nuclear antigen (PCNA) provided semiquantitative estimates of proliferation. The main localizations were the pharynx (64/107) and the larynx (21/107). Positive IHC detection of p53 was observed in 9% of normal-appearing carcinogen-exposed mucosas, 37% of hyperplasias, 68% of dysplasias, 75% of in situ carcinomas, and 56/99 (56.5%) of primary tumor samples. Mucosas from 15 control patients under 10 years of age were negative. There was no correlation between p53 IHC and localization, differentiation or TNM staging.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Expression of c-ets-1, collagenase 1, and urokinase-type plasminogen activator genes in lung carcinomas.

The c-ets-1 transcription factor has been involved in the in vitro transactivation of matrix-degrading protease genes that might play an important role in tumor invasion. Using in situ hybridization, we analyzed serial frozen sections for c-ets-1, collagenase 1, and urokinase-type plasminogen activator gene expression in 54 lung carcinomas including 34 non-neuroendocrine carcinomas (18 squamous carcinomas, 10 adenocarcinomas, 3 large cell carcinomas, and 3 basaloids) and 20 neuroendocrine carcinomas (7 small cell lung carcinomas, 4 large cell neuroendocrine carcinomas, 4 well differentiated neuroendocrine carcinomas, and 5 carcinoids). c-ets-1 gene was expressed in stromal cells in 44/54 lung carcinomas including one metastasizing carcinoid. c-ets-1 transcripts were also detected in cancer cells more frequently in neuroendocrine than in non-neuroendocrine carcinomas (P = 0.0059) and in stages III and IV and metastasis more frequently than in stages I and II ( P = 0.0065). Collagenase 1 gene was expressed in 16/34 non-neuroendocrine tumors and in 1/20 neuroendocrine tumors, either in stromal (12/17) or in cancer cells (6/17). Urokinase-type plasminogen activator mRNAs were expressed in 45/54 lung carcinomas in stromal and/or cancer cells. In non-neuroendocrine tumors, c-ets-1 and collagenase 1 gene expressions in stromal cells were correlated. These results demonstrate that the transcription factor c-ets-1, collagenase 1, and urokinase-type plasminogen activator are involved in lung cancer invasion and suggest that c-ets-1 protein might transactivate collagenase 1 gene during tumor invasion.

Carcinoma↗
PubMed1995

[Diffuse pulmonary infiltration at the onset of Waldenström's disease].

The case of an 52 years old female presenting dyspnea and pulmonary infiltration is reported. A transbronchial biopsy showing a lymphomatous infiltrate with immunohistochemistry using anti-IgM antibody on paraffine embedded section helped to diagnose. A monoclonal increase in seric immunoglobin M, led to the diagnosis of Waldrenström's macroglobulinemia. An initial therapeutic response to Chlorambucil was obtained. But a quick recurrence was observed, with an increase of seric IgG.

Female↗
PubMed1995

[Basal cell (basaloid) carcinoma of the bronchi].

Basal cell carcinomas (BCC) have been described in various locations such as skin, anal canal, tongue, larynx and recently the lungs. These tumors seem to have a poor prognosis. A series of 115 surgically resected lung tumors, previously classified as poorly or undifferentiated carcinoma was retrospectively reviewed. From those 37 cases were reclassified as BCC and were compared in terms of clinical features and survival with 40 cases reclassified as poorly differentiated squamous cell carcinoma (PDSC) of the lung. There was no difference between the groups with respect to age, clinical presentation, pattern of relapse and cause of death. Median and overall survival were different between the 2 groups, especially for stage I and II patients: 5 years actuarial survival in BCC was 15% and in PDSC 47% p = 0.009). There was also a difference in survival when we studied the patients alive 4 weeks after surgery (p = 0.04). This subset of non small cell lung cancer (NSCLC) has a worse prognosis than other NSCLC.

Actuarial Analysis↗
PubMed1994

Loss of heterozygosity at the RB locus correlates with loss of RB protein in primary malignant neuro-endocrine lung carcinomas.

RB protein expression and loss of heterozygosity (LOH) in the RB gene were studied in 77 primary lung carcinomas of all histological types. RB protein expression was studied by immunohistochemistry with 3 anti-RB antibodies, and was found altered in 23/29 (79%) neuro-endocrine (NE) carcinomas and in 18/48 (37%) non-NE carcinomas. RB gene allele status was studied with 3 probes detecting RFLP in RB locus. Fifty-five patients were informative, and loss of heterozygosity was detected in 29 (52%) of the corresponding tumors with 1 of the 3 probes used; 89% of the informative NE carcinomas, excluding carcinoids, and only 13% of the non-NE carcinomas exhibited LOH and loss of RB-protein expression. LOH at the RB locus was strongly correlated with the absence of RB protein in malignant NE carcinomas, and this association was strongly correlated with the neuro-endocrine phenotype. Inactivation of the RB protein in primary NE carcinomas, excluding carcinoids, therefore seems to imply in the majority of cases the mutation of one allele and loss of the remaining allele of the RB gene, leading to loss of RB-protein expression. In contrast, RB-protein expression was independent of allele status in non-NE carcinomas and carcinoids.

Gene Deletion↗
PubMed1994

p53 genetic abnormalities and myc activation in human lung carcinoma.

p53 mutations and myc gene amplification and expression were studied in 119 lung carcinomas of all histological types. A mutant p53 immunophenotype was previously found in 47% of these tumors by immunohistochemical analysis. Seven cases exhibited p53 genomic rearrangements on Southern blots. Elevated levels of p53 transcript were found in 12 carcinomas (10%) and decreased levels in 27 carcinomas (23%) on Northern blots. In most of the cases, low levels of transcript were associated with negative immunostaining, whereas elevated levels of mRNA were related to positive immunostaining (mutant immunophenotype). p53 RT/PCR analysis in 10 tumors with absence of transcript on Northern blots revealed only weak or absent expression of normal and/or altered size transcripts. These abnormal transcripts showed deletions, insertions or splicing abnormalities. Taken together, p53 abnormalities were found in 66% of lung carcinomas [52% of neuroendocrine (NE) carcinomas and 75% of NSCLC]. c-myc was found to be activated in 24% (10/42) of these NE and in 48% (33/69) of these NSCLC carcinomas using Southern- and Northern-blot techniques. In addition, L- and N-myc genes were also activated in 26% (10/42) of NE carcinomas. No correlation was found between p53 mutations and myc activation in SCLC or in NSCLC, but their association was significantly more frequent in NSCLC than in SCLC. These results indicate that the p53-positive immunophenotype uncovers the occurrence of p53 point mutations in lung cancer and that p53 and c-myc gene alterations are important but represent independent occurrences in the development of lung tumors.

Base Sequence↗
PubMed1994

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) affects the actin cytoskeleton and calcium level of Swiss 3T3 mouse fibroblasts.

Organization of the actin cytoskeleton, the cytosolic free-calcium concentrations and ATP levels were analyzed in 3T3 mouse fibroblasts treated with 0.75 or 1.5 mM MPTP. In the presence of the drug actin filaments were time- and dose-dependently disorganized, ATP level was unaffected and intracellular calcium increased within 5 s. The correlation between MPTP cytotoxicity and [Ca2+]i level emerging from these results, suggests that the primary effect of the molecule itself is on the plasma membrane's integrity for calcium ion regulation.

Actins↗
PubMed1994

Basaloid bronchial carcinoma. A histologic group with a poor prognosis.

BACKGROUND: Basal cell carcinomas (BCCs) have been described in various locations, such as skin, anal canal, tongue, larynx, and recently, the lungs. These tumors seem to have a poor prognosis. METHODS: A series of 115 surgically resected lung tumors, previously classified as poorly or undifferentiated carcinoma, were reviewed retrospectively. From these, 37 cases were reclassified as BCCs and were compared in terms of clinical features and survival, with 40 cases reclassified as poorly differentiated squamous cell (PDSC) carcinoma of the lung. RESULTS: There was no difference between the groups regarding age, clinical presentation, pattern of relapse, and cause of death. Median and overall survival were different between the two groups, especially for Stage I and II patients: 5-year actuarial survival in the BCC group was 15% and in the PDSC group 47% (P = 0.004). CONCLUSIONS: This subset of non-small cell lung cancer (NSCLC) has a worse prognosis than other NSCLC, and this should be considered in survival studies and new treatment trials.

Adult↗