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R Soares

Publications and source records attributed to R Soares.

At least 19 recordsLinked to original sources
PubMed2004

Evidence for the notch signaling pathway on the role of estrogen in angiogenesis.

We have investigated the molecular mechanisms involved in 17 beta-estradiol-induced angiogenic pathway. We show here that 17 beta-estradiol promoted a 6-fold increase in Jagged1 expression and an 8-fold increase in Notch1 expression by cDNA arrays in breast cancer MCF7 cells. Interestingly, Jagged1 was abrogated by incubation with the estrogen antagonist, ICI182,780. A similar up-regulation of both Notch1 receptor and Jagged1 ligand was found in endothelial cells. Additionally, imperfect estrogen-responsive elements were found in the 5' untranslated region of Notch1 and Jagged1 genes. Treatment with 17 beta-estradiol also led to an activation of Notch signaling in MCF7 cells expressing Notch1 reporter gene or by promoting Jagged1-induced Notch signaling in coculture assays. Inoculation of MCF7 cells in 17 beta-estradiol-treated nude mice resulted in up-regulation of Notch1 expression as well as increased number of tumor microvessels in comparison to placebo-treated mice. Notch1-expressing endothelial cell cultures formed cord-like structures on Matrigel in contrast to cells expressing a dominant-negative form of Notch1, emphasizing the relevance of Notch1 pathway in vessel assembly. Finally, Notch1-expressing MCF7 cells up-regulated hypoxia-inducible factor 1 alpha gene, a well-known angiogenic factor that clustered with Notch1 gene. This study implicates Notch signaling in the cross talk between 17 beta-estradiol and angiogenesis.

Animals↗
PubMed2002

[Analysis of mutations in genes BRCA1 and BRCA2 among patients with breast and ovarian cancer in northern Portugal and Galicia].

OBJECTIVE: To detect mutations in the BRCA1 and BRCA2 genes by means of the protein truncation test (PTT) in a population in northern Portugal and Galicia with breast and ovarian cancer. DESIGN: Prospective study. SETTING: Patients in northern Portugal and Galicia with family history of breast and/or ovarian cancer.Patients. A total of 76 women with family history of breast cancer according to the BCLC criteria (Breast Cancer Linkage Consortium) were studied at IPATIMUP. MAIN RESULTS: Five cases (6.5%) with changes in the normal sequence in genes BRCA1 and BRCA2 were identified; three of these mutations occurred in the gene BRCA1 and the other two in the gene BRCA2. Two out of the three mutations found in the gene BRCA1 were de novo mutations. Changes detected in the normal sequence in the gene BRCA2 were mutations reported for the first time among the study population, according to the information obtained through the BCIC database (Breast Cancer Information Core). CONCLUSIONS: This was the first study in detecting individuals carrying mutations in the susceptibility breast cancer genes BRCA1 and BRCA2 among the population of northern Portugal and Galicia.

Breast Neoplasms↗
PubMed2002

Comparison of chickpea rhizobia isolates from diverse Portuguese natural populations based on symbiotic effectiveness and DNA fingerprint.

AIMS: To test the hypothesis that differences in chickpea yields obtained in four distinct Portuguese regions (Beja, Elvas-Casas Velhas, Elvas-Estação Nacional de Melhoramento de Plantas (ENMP) and Evora) could be due to variation between the natural rhizobia populations. METHODS AND RESULTS: Estimation of the size of the different rhizobial populations showed that Elvas-ENMP population was the largest one. Elvas-ENMP population also revealed a higher proportion of isolates carrying more than one plasmid. Assessment of genetic diversity of the native rhizobia populations by a DNA fingerprinting PCR method, here designated as DAPD (Direct Amplified Polymorphic DNA), showed a higher degree of variation in Elvas-ENMP and Beja populations. The symbiotic effectiveness (SE) of 39 isolates was determined and ranged 13-34%. Statistical analysis showed that SE was negatively correlated with plasmid number of the isolate. CONCLUSIONS: The largest indigenous rhizobia population was found in Elvas-ENMP. DAPD pattern and plasmid profile analysis both suggested a higher genetic diversity among the populations of Elvas-ENMP and Beja. No relationship was found between SE of the isolates and their origin site. SIGNIFICANCE AND IMPACT OF STUDY: The large native population, rather than the symbiotic performance of individual rhizobia, could contribute to the higher chickpea yields obtained in Elvas-ENMP.

Cicer↗
PubMed2002

Cyclo-oxygenase 2 expression is associated with angiogenesis and lymph node metastasis in human breast cancer.

AIMS: Cyclo-oxygenases 1 and 2 (COX-1 and COX-2) are key enzymes in prostaglandin biosynthesis. COX-2 is induced by a wide variety of stimuli, and present during inflammation. COX-2 overexpression has been observed in colon, head and neck, lung, prostate, stomach, and breast cancer. In colon and gastric cancer, COX-2 expression was associated with angiogenesis. The aim of this study was to determine the relation between COX-2 expression and angiogenesis in breast cancer, and to correlate the expression of this enzyme with classic clinicopathological parameters. METHODS: COX-2 expression was investigated by immunohistochemistry and western blotting analysis. The expression of COX-2 was then related to age, histological grade, nodal status, oestrogen receptor status, p53 expression,c-erb-B2 overexpression, mitotic counts, MIB-1 labelling index, apoptotic index, sialyl-Tn expression, transforming growth factor alpha expression, microvessel density, and disease free survival in 46 patients with invasive ductal breast carcinoma. RESULTS: By means of immunohistochemistry, COX-2 expression was detected in eight of the 46 carcinomas studied. Western blotting showed COX-2 protein expression in the same breast tumours, but not in normal adjacent tissues. The density of microvessels immunostained with anti-F-VIII related antigen was significantly higher in patients with COX-2 expression than in those without expression (p = 0.03). In addition, COX-2 was significantly associated with the presence of sialyl-Tn expression (p = 0.02), lymph node metastasis (p = 0.03), a high apoptotic index (p = 0.03), and a short disease free survival (p = 0.03) in univariate analyses. CONCLUSIONS: These data suggest that COX-2 expression is associated with angiogenesis, lymph node metastasis, and apoptosis in human breast cancer. Moreover, these results warrant further studies with larger series of patients to confirm the association with short disease free survival in patients with breast cancer.

Adult↗
PubMed2000

Unstable angina: individualized stratification and prognosis.

OBJECTIVE: To analyse the methodology of risk stratification and the prognosis of patients admitted with unstable angina. POPULATION AND METHODS: This retrospective study involved a population of 68 patients (43 males and 25 females with a mean age of 65.8 +/- 9.8 years) consecutively admitted for suspected unstable angina during the year of 1996. Thirty six patients (52.9%) had angina at rest, 13 patients (19.1%) had both exertional and rest angina, 9 patients (13.2%) crescendo angina, 6 patients (8.8%) new onset exertional angina (less than 1 month), and 4 patients (5.8%) post-infarction angina (less than 2 weeks). The risk stratification was individualized. The coronary angiography (35 patients) was only performed when the medical therapy failed in patients with recurrent angina, or with proved ischemia after an exercise test and/or thallium 201 stress scintigraphy. Thirteen patients (19.1%) did not undergo these tests (advanced age and or bad general condition, or refusal). The follow-up of patients with and without ST-T changes was compared, as well as those revascularized versus non-revascularized. It was possible to achieve a mean follow-up of 13.7 +/- 6.2 months (3 to 25 months). RESULTS: The exercise test and/or thallium-201 stress scintigraphy were positive for myocardial ischemia in 28 pts (41.1%) and negative in 7 patients (10.2%). The coronary angiography revealed three-vessel coronary artery disease in 18 patients (26.4%), one vessel disease in 11 patients (16.1%) and two-vessel disease in 5 patients (7.3%). One patient had normal coronary arteries. Medical therapy was the initial approach. Coronary surgery was urgently performed in 3 patients and coronary angioplasty in 5 patients for refractory unstable angina. In the whole group coronary artery surgery was undertaken in 14 patients (20.5%) and coronary angioplasty in 12 patients (17.6%). A mean follow-up of 13.7 +/- 6.2 months was obtained in the 68 patients. During this period 6 patients (8.8%) died due to cardiac causes and 16 patients (23.5%) were readmitted: 8 patients (11.7%) for unstable angina, 5 patients (7.3%) for congestive heart failure and 3 patients (4.4%) for myocardial infarction. Fifty two patients (76.4%) remained free of cardiac events. The patients with transitory ST-T changes had more cardiac events (unstable angina, myocardial infarction, mortality) than the patients without ECG changes (13/30 vs 2/30, p = 0.003). When the revascularized patients were compared to the non revascularized no significant differences were observed regarding myocardial infarction and mortality, however revascularized pts had a less significant incidence of rehospitalization for unstable angina (0/26 vs 8/42 p = 0.02). CONCLUSIONS: An individualized strategy can be effective in pts with unstable angina. In this study 76.4% of patients remained free of cardiac events during the follow-up, 23.6% had severe cardiac events and the cardiac mortality was 8.8%. The patients with transitory ST-T changes had more cardiac events and worse prognosis. No patients significant difference was observed in the revascularized versus non revascularized patients for myocardial infarction and mortality; however, the revascularized patients had less significant incidence of rehospitalization for unstable angina.

Adult↗
PubMed1999

Microsatellite instability in medullary breast carcinomas.

Microsatellite instability (MSI) has been reported to occur in a wide variety of sporadic tumours, such as colorectal and gastric cancers. MSI positivity has been associated with a particular clinico-pathologic profile, including the presence of abundant lymphoid infiltration, poor differentiation and a relatively good outcome for the patients. Since medullary breast carcinomas (MBCs) share these clinico-pathologic features with the MSI-positive tumours described above, we evaluated MSI in this particular histologic type of breast cancer. DNA of 24 MBC cases was extracted from formalin-fixed, paraffin-embedded tissue. The presence of MSI was analysed using BAT-26. We also searched mutations in 2 target genes: TGF-beta RII and BAX. Five cases of the series were also analysed for 1 (CA) dinucleotide tandem repeat sequence (D1S158), 8 tetranucleotide repeat sequences (D3S1358, D5S818, D7S820, D8S1179, D13S317, D21S11, FGA and VWA) and 1 pentanucleotide repeat (dAAAAT), localized in intron 1 of p53 gene. We found 2 carcinomas (8.3%) with BAT-26 instability. None of the cases had mutations in the "target genes", TGF-beta RII and BAX, including the 2 cases with BAT-26 instability. No MSI was observed using the panel of tetra- and pentanucleotide markers. Loss of heterozygosity was found in some loci. No significant difference in mean MIB-1 index according to RER status was observed. The low frequency of MSI in MBC is similar to that of other histologic types of breast cancer. Although MBCs share some clinico-pathologic features with colorectal and gastric carcinomas, which exhibit a high frequency of MSI, the underlying genetic events leading to this breast tumour are different from those leading to tumours of the digestive tract.

Breast Neoplasms↗
PubMed1998

Detection of numerical chromosome 17 abnormalities in fine-needle aspirates of breast cancer using a novel in situ hybridization signal amplification method.

We describe a method of in situ hybridization (ISH) to assess numerical chromosome abnormalities on alcohol-fixed smears obtained by fine-needle aspiration from breast cancer patients, using a commercially available amplification kit to demonstrate numerical chromosome alterations of chromosome 17. In this staining procedure after detection of the biotin-labeled alpha-satellite probe for chromosome 17 with avidin-biotin-peroxidase, we incorporated a signal amplification based on the peroxidase-catalyzed deposition of a biotinylated phenolic compound followed by a secondary reaction with peroxidase. The reactions are revealed by deposition of diaminobenzidine and can be analyzed in an optical microscope, with total preservation of the morphology, allowing a direct morphologic-cytogenetic correlation. A series of 25 cases of aspirates from breast cancer were analyzed with this methodology. Aneusomy was found in 14 cases (56%), whereas 11 (44%) had a normal number of chromosome 17 copies. Polysomy occurred in all aneusome cases except one. We did not find concordance between numerical chromosome abnormalities of chromosome 17 and nuclear grading as well as with the immunoexpression of p53 and c-erbB2 studied in the smears. We conclude that the application of the ISH signal amplification method on alcohol-fixed smears will eliminate the need for fresh material and will provide several advantages, such as improvement of morphological concomitant analysis without the need for a fluorescence microscope; utilization, whenever malignancy is found, without necessity to reaspirate the patient; and adequacy of archival material.

Adult↗
PubMed1998

PCR amplification of DNA obtained from archived hematoxylin-eosin--and giemsa-stained breast cancer aspirates.

The study of DNA abnormalities in fine-needle aspiration (FNA) specimens for breast cancer could be helpful in improving the capacity of diagnosis and specially to obtain prognostic or predictive information. The aim of the present study was to verify whether it is possible to perform molecular analysis in slides of breast cancer FNA specimens. previously stained by hematoxylineosin (H&E) and Giemsa, stored at least for 3 years. For this purpose, 10 cases of FNA obtained from breast cancer patients diagnosed between 1993 and 1994 in our institute were used. Five cytologic smears were alcohol-fixed and stained with H&E. The other five were air-fixed and Giemsa stained. DNA was isolated from the cytologic smears and amplified by using radioactive polymerase chain reaction (PCR) aimed at BAT-26 marker. Our results demonstrate that archived stained smears prepared for cytologic examinations can be used for molecular analyses by using a PCR amplification method. DNA could be isolated and PCR amplified independently of the prior fixation and staining procedures. So, we conclude that the application of molecular biology techniques to the existing archival smears may become a valuable tool to detect genetic changes in samples from breast cancer aspirates.

Adult↗
PubMed1998

Bilateral apocrine carcinoma of the breast. Molecular and immunocytochemical evidence for two independent primary tumours.

Apocrine carcinoma is an uncommon variant of breast cancer. The frequency of bilaterality in patients who have apocrine carcinoma in one breast is not significantly different from that for bilateral mammary carcinomas in general, but bilateral apocrine carcinomas are very uncommon. We report on a bilateral apocrine carcinoma of the breast in a 74-year-old woman. The apocrine differentiation in both tumours was confirmed by the positivity of the cytoplasmic granules for PAS after diastase digestion and immunoreactivity for GCDFP-15 and sialyl-Tn. The tumour in the right breast showed immunohistochemical expression of p53, and a mutation was demonstrated by PCR-SSCP; the tumour in the left breast was negative for p53 on immunohistochemistry, and no mutation was found at the molecular level. c-erbB2 expression was not detected in the right tumour but there was overexpression (at the cell membrane) in the left tumour. Both tumours were aneuploid: the right tumour displayed multiple stemlines, whereas the left tumour had a triploid profile. Using the fluorescence in situ hybridization technique we demonstrated that both tumours displayed chromosome 17 polysomy and numerical abnormalities of chromosome 1, polysomy in the right and monosomy in the left tumour. We conclude that the two tumours are probably independent, as are most bilateral carcinomas of the breast.

Aged↗
PubMed1998

P53 in breast carcinomas: association between presence of mutation and immunohistochemical expression using a semiquantitative approach.

The aim of this study was to evaluate the concordance between the presence of p53 mutations in breast carcinomas expressing the protein by immunohistochemistry. A series of 60 breast carcinomas was evaluated by immunohistochemistry using monoclonal antibodies against p53 protein (DO 7 and PAb 1801). Twenty cases classified as being positive for p53 according to the current approach (if 5% or more of neoplastic cells contained reaction product in the nucleus) were used for molecular studies. These cases were re-assessed semi-quantitatively using a scoring system based on intensity and percentage of stained cells. DNA was phenol-chloroform extracted from microdissected normal and tumour cells obtained from formalin-fixed, paraffin-embedded tissue sections. Mutations in the p53 gene were analysed by SSCP (single strand conformational polymorphism) with primers covering exons 2-3 to 11. Ten out of the 20 p53-positive cases presented mutations detected by SSCP analysis. Mutations have been found in several exons ranging from exon 4 to exon 10. We observed a positive relationship between the presence of mutations and immunohistochemical evaluation of p53 protein expression using a semiquantitative scoring system. All cases with more than 2/3 stained tumour cells and strong intensity of staining exhibited p53 mutations. At variance, no p53 mutations were found in cases with less than 1/3 stained tumour cells and moderate intensity of staining. Therefore, only the identification of positivity for p53 detected by immunohistochemistry did not always reflect the detection of p53 mutations in breast cancer, however the use of a semi-quantitative approach seems to be useful as an indicator of the presence of mutation.

Adult↗
PubMed1998

Reduction in temporal N-acetylaspartate and creatine (or choline) ratio in temporal lobe epilepsy: does this 1H-magnetic resonance spectroscopy finding mean poor seizure control?

BACKGROUND: Proton magnetic resonance spectroscopy (1H-MRS) is a potentially useful tool in the in vivo investigation of brain metabolites in intractable temporal lobe epilepsy (TLE). Focal N-acetylaspartate (NAA) reductions have been correlated with mesial temporal sclerosis (MTS) in surgically resected epileptogenic foci. OBJECTIVE: To evaluate the abnormalities in the metabolites NAA, creatine+ phosphocreatine (Cr), and choline containing compounds (Cho) in the temporal lobe of medically refractory patients with temporal lobe epilepsy, seizure free patients with temporal lobe epilepsy, and normal controls. PATIENTS AND METHODS: Ten refractory patients, 12 seizure free patients with temporal lobe epilepsy, and 10 age matched normal controls were studied by 1H-magnetic resonance spectroscopy. All patients had consistently unilateral temporal EEG abnormalities and a normal brain MRI. Proton MR spectra were obtained from an 8 ml volume in the medial temporal lobes in patients with temporal lobe epilepsy (ipsilateral to EEG foci) and the normal controls. The signals measured were expressed in terms of NAA/Cr, NAA/Cho, and Cho/Cr. RESULTS: When compared with seizure free patients with temporal lobe epilepsy and normal controls, the 10 refractory patients with temporal lobe epilepsy had a lower mean (SEM) NAA/Cr ratio (1.65 (0.53) v 2.62 (0.60), and 2.66 (0.73); p<0.002 and p<0.006) and a lower mean NAA/Cho ratio (1.59 (0.79) v 2.83 (1.33) and 2.58 (0.67); p<0.02 and p<0.007). Furthermore, the two patients showing the lowest NAA/Cr ratios (1.47 and 1.73) in the seizure free group had had a past period of poor seizure control. CONCLUSIONS: There were reduced temporal NAA/Cr and NAA/Cho ratios, suggesting neuronal loss or damage, associated with past or present poor seizure control in the patients with temporal lobe epilepsy, but it does not exclude the possibility of a future complete seizure control (seizure free patients with temporal lobe epilepsy at the time of 1H-MRS). This study warrants further 1H-MRS investigation with a larger series of patients with temporal lobe epilepsy.

Adolescent↗
PubMed1997

Angiogenesis in breast cancer is related to age but not to other prognostic parameters.

Angiogenesis is essential for tumour growth and metastasis. In spite of its relevant biological significance, recent studies have produced conflicting results regarding the capacity of microvessel quantifications in breast carcinomas to predict patients' outcome and the existence of metastasis. In order to provide further information in this issue, we evaluated tumour angiogenesis in a series of 45 primary breast carcinomas (mean age: 55.3 +/- 14.2) and examined their association with established or potentially useful prognostic parameters. Microvessels were highlighted by immunohistochemical staining for factor VIII-related antigen and counted in the three most vascularized areas in a 200 x field (0.74 mm2) by four observers simultaneously. Results were analysed for the average vessel count of each case. The mean intratumoural microvessel count was 57.7 +/- 24.4 (range: 24.3 to 127.7). We found a statistically significant association between angiogenesis and age. The microvessels count in patients younger than 50 years was 67.8 +/- 26.4, from 51 to 70 years, 52.0 +/- 22.8 and over 71 years, 46.1 +/- 14.2 (p = 0.03). Node positive patients had slightly higher microvessel counts (60.3 +/- 25.3) than node negative ones (54.4 +/- 23.5); this difference was not significant (p = 0.42), even when we considered each age group per se. No association was found between angiogenesis and tumour size, histologic grade, estrogen receptor, MIB-1 index, ploidy and expression of p53 and c-erbB-2. Our results suggest that invasive breast carcinoma-induced angiogenesis is age-dependent.

Adult↗
PubMed1996

Expression of sialyl-Tn in breast cancer. Correlation with prognostic parameters.

To investigate the expression of a simple mucin-type carbohydrate antigen (Sialyl-Tn/STn) and its putative relationship with established or potentially useful clinico-pathologic prognostic parameters in breast cancer, we studied forty-six cases of invasive breast carcinoma in formalin-fixed, paraffin-embedded tissue sections. STn antigen was detected by the HB-STn antibody using an avidin-biotin-peroxidase method. The parameters studied were tumour size, histologic grade, nodal status, proliferative index (with MIB-1), ER expression, ploidy, c-erbB-2 and p53 expression. STn expression was observed in 18 cases (39%) of breast cancer. The expression of STn was associated with axillary node metastasis, ER negativity and c-erbB-2 expression. A tendency towards an association between STn immunoreactivity and high histologic grade was also found. No correlation was observed between STn immunoreactivity and age, tumour size, proliferative index, ploidy and p53 expression. We conclude that the detection of STn immunoreactivity may be useful for predicting the likelihood of lymph node metastasis and that the outcome of patients with breast cancer should be further investigated in order to find whether or not the data of the present study are confirmed in larger series.

Adult↗