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Biomedical subjects

I Roa

Publications and source records attributed to I Roa.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Immunohistochemical expression of epidermal growth factor receptor (EGFR) in epidermoid carcinoma of the cervix uteri and its precursor lesions].

The epidermal growth factor receptor (EGFR) immunohistochemical expression was determined in 24 histological samples of squamous cell carcinoma of the cervix, 81 cervical squamous intraepithelial lesions (47 low-grade and 34 high grade), 20 normal squamous epithelia, 11 squamous mature metaplasias and 14 cervical adenocarcinomas. In 30 cases, it was determined by means in situ hybridization the presence of Human Papillomaviruses 6/11, 16/18 and 31/33/35. The immunohistochemical EGFR expression was higher in high-grade epithelial lesions (64.7%), particularly moderate dysplasia (72.2%), than in low-grade lesions (44.7%) and squamous carcinoma (45.8%), with significance differences only between high-grade lesions and normal squamous epithelia (p < 0.02). There were not EGFR expression differences between cervical squamous carcinoma (45.8%) and adenocarcinoma (42.9%). These findings suggest that the elevated expression of EGFR may be linked, at least initially, to the malignant state of the cervical squamous epithelia. On the other hand, the higher presence of HPV 16/18 than other HPV types in EGFR positive lesions, indicates some association between both factors.

Adenocarcinoma↗
PubMed1994

[Proliferating cell nuclear antigen (PCNA) in patients with malabsorption syndrome: comparative study with morphometric parameters].

The study of small bowel mucosa is routine in the study of patients with malabsorption. We report 16 children aged from 8 months to 6 years old (2 with giardiasis, 8 with primary malnutrition and 5 with celiac disease) in whom a morphometric and PCNA immunostaining was performed in the small intestinal biopsy. Positivity for PCNA was found in the lower portion of the crypts reaching 156 microns of heigh in patients with giardiasis, 103 microns in primary malnutrition and 182 microns in celiac disease (p < 0.01 compared to primary malnutrition). A negative and significant correlation was found between the degree of architectural disorder (expressed the mucosal index) and the proliferative portion of the crypts (expressed as the percentage of PCNA(+) crypts. We propose these methods as complements to the small bowel mucosa histopathological study in the diagnosis of celiac disease, to assess the degree of architectural disorder and the proliferative activity.

Child↗
PubMed1994

[Expression of p29, estrogen receptor related protein in primary breast carcinoma. Methodological, anatomoclinical, and DNA content analysis].

The aim of this work was to assess the immunohistochemical detection of a estrogen receptor related protein (p29) in 48 histological samples of primary mammary carcinoma and its relationship to clinical, morphological and ADN content parameters. p29 protein was positive in 62.5% of samples. Over 50% of samples had a moderate or intense immunohistochemical staining (staining index over 16) and 77% has a heterogeneous expression of p29 protein. Seventy six percent of p29 positive and 53% of p29 negative tumors had a proliferation fraction over 10% (determined by the S fraction with flux cytometry). No relationship between p29 expression and the analyzed anatomoclinical variables was found. These results highlight this immunohistochemical method as an alternative to more complex and difficult biochemical techniques. On the other hand, the good results obtained in formalin fixed tissues allow retrospective studies in mammary carcinoma samples.

Biomarkers, Tumor↗
PubMed1994

[Gallbladder cancer in the IX Region of Chile. Impact of the anatomopathological study of 474 cases].

We studied prospectively 474 cases (83% female with a female:male ratio of 5:1) of gallbladder carcinoma diagnosed in a period of 7 years. Twenty two percent of patients were younger than 50 years old. Ninety percent of tumors were adenocarcinomas. In 1987, 45% of cases were diagnosed in metastases compared to 1993, when only 10% of tumors were diagnosed in such histological material. Thirty four percent of tumors were not macroscopically identified; all these inapparent tumors were advanced in 1987, whereas 53% were incipient in 1993. Moreover, inapparent tumors had a significantly lower degree of gallbladder wall infiltration and higher degree of differentiation. Well differentiated tumors had a lesser degree of wall infiltration. It is concluded that the careful histopathological study of gallbladder cancer has allowed a thorough knowledge of the natural history and clinical presentation of gallbladder carcinoma.

Adenocarcinoma↗
PubMed1994

[Breast cancer and flow cytometry: comparative study of DNA ploidy pattern with clinicopathological parameters].

There is evidence that DNA quantization and histopathological classification of breast cancer may be useful for its therapeutic management. DNA flow cytometry, clinical and anatomopathological features of 60 paraffin embedded primary breast cancer tissue samples were studied. The aneuploidy percentage was 67%. There was a correlation between DNA index and degree of cellular pleomorphism, degree of differentiation and the fraction of cells in S phase. Likewise a correlation was found between the degree of cellular pleomorphism and the mitotic index. DNA cytophotometry was useful to solve cases of difficult diagnosis with flow cytometry ("near" diploid and tetraploid tumors). No correlation was found between aneuploidy, percentage of cells in phase S, degree of cellular atypia and mitotic degree with clinical stage, degree of lymph node involvement, tumoral size or age. It is suggested that these variables may have an independent behavior.

Adult↗
PubMed1994

[Gallbladder carcinoma: expression of the c-myc and ras-p-21 oncogene products].

The expression of c-myc and p-ras-21 oncogenes was studied using an immunohistochemical method with monoclonal antibodies in 126 samples of gallbladder carcinoma (103 primary tumors and 23 metastatic lesions). Twenty five gallbladder samples without tumor evidence were used as controls. C-myc oncoprotein was positive in one control sample and p-ras-21 oncoprotein was negative in all. Among primary carcinomas c-myc was positive in 9 (9%) and p-ras-21 in 4 (4%); among metastatic carcinomas c-myc was positive in 6 (26%, p = 0.03 vs primary carcinoma) and p-ras-21 in 11 (48%, p < 0.001 vs primary carcinoma). There was a non significant association between c-myc and p-ras-21 expression and degree of histological differentiation and level of tumoral infiltration. It is concluded that c-myc and p-ras-21 oncoprotein expression is observed in less than 10% of primary gallbladder carcinomas and that this expression is significantly higher in metastatic carcinomas. This may reflect an activation or overexpression of these oncogenes in metastatic cells.

Amino Acid Sequence↗
PubMed1994

[Determination of DNA content using cytophotometry in nuclear suspension conserved for prolonged periods (preliminary study)].

The variations in cytophotometric determination of DNA content were studied in a concentrated suspension of nuclei stored for prolonged periods. These came from normal and tumoral cells of an uterine leiomyosarcoma, fixed in formalin and included in paraffin. DNA was measured in normal and tumoral cells at days 0, 1, 7, 11, 19, 27 and 33. No significant variations in DNA measurement were observed. In a same day, there was an uniform DNA content, ploidy pattern and DNA index and an aneuploid pattern was diagnosed in all histograms. These results suggest that nuclear suspensions can be conserved for long periods and used for DNA content determination, allowing the access of remote places to these techniques.

Cytophotometry↗
PubMed1994

[Nucleolar organizer region in bladder cancer. Relationship with histologic grade, stage, and prognosis].

By means of silver staining, 31 transitional bladder cancer were studied in order to quantify the number of the nucleolar organizer regions and ist relationship with histological grade, tumoral stage and prognosis of the disease. The group under study was composed by 18 cases superficial carcinomas (T1 stage), and 13 deep carcinomas (T2 and T3b stage). A significant difference between normal and neoplastic bladder mucosa, and between T1 and t3b stage was demonstrated (p = 0.03). However, ther was not difference between patients whom develop recurrences. In this study we were not able to demonstrate the importance of the count of the nucleolar organizer regions as prognostic factor in bladder cancer.

Aged↗
PubMed1993

Proliferating cell nuclear antigen in gallbladder carcinoma.

Proliferating cell nuclear antigen (PCNA) expression was studied in 103 gallbladder carcinomas and 23 metastatic lesions as well as in 25 control non-neoplastic gallbladder specimens. Positive nuclear staining was observed in 88% of controls, in 92% of carcinomas and in 70% of metastases. The mean number of positive cells was 21.2% in controls, 44.1% in primary carcinomas and 32% in metastatic cancer cells. Differences which were significant were control v. primary tumour, P < 0.000001; control v. metastasis, P < 0.01 and primary tumour v. metastasis, P < 0.006. In 57 (60%) of the primary tumours there was positive staining in over 40% of tumour cells. We were not able to demonstrate any relationship between macroscopic or microscopic features and PCNA expression. However, tumours confined to the mucosa expressed PCNA more frequently than did more advanced tumours.

Biomarkers, Tumor↗
PubMed1993

DNA content in gallbladder carcinoma: a flow cytometric study of 96 cases.

The DNA content in gallbladder carcinoma and its relation to histological and cytological features was studied in 79 primary gallbladder carcinomas and 16 metastases. Abnormal DNA content was observed in 48 (51%) of 95 cases. In primary carcinomas, 44 (55.6%) showed a diploid DNA content, and 35 (44.4%) were aneuploid. The majority of the metastatic lesions were aneuploid DNA (81.3%; P = 0.006). Marked differences in the coefficient of variation estimated by manual, Kosugi and Dean methods were detected (P = 0.005). Seventy-one per cent of early gallbladder carcinomas had a normal DNA content. In contrast 54% of the cases with subserosal or serosal infiltration had normal DNA content. In primary tumours the degree of architectural atypia had a close relationship with the degree of cellular atypia (P = 0.00001). Only two (15%) of 13 cases with mild architectural atypia, and 34 (51.5%) of 66 cases with marked architectural atypia were aneuploid. Only one (10%) of 10 cases with mild cellular atypia and 35 (51%) of 69 with high cellular atypia had abnormal DNA content (P = 0.01) The importance of DNA content as a marker in gallbladder carcinoma remains uncertain and its clinical importance requires further clinicopathological studies.

Adenocarcinoma, Papillary↗
PubMed1993

[Nucleolar organizer regions in uterine cervical cancer and its precursor epithelial lesions].

The number of nucleolar organizer regions was assessed in 115 histological samples of uterine cervical carcinoma or precursor epithelial lesions. Normal endocervical or exocervical epithelial tissues were used as controls. Nucleolar organizer regions were stained with colloidal silver in formalin fixed histological samples and quantified in 100 cells, according to Crocker's method. The mean number of nucleolar organizer regions were 13.7 in infiltrative carcinoma, 9.15 in carcinoma in situ, 9.3 in severe dysplasia, 8.4 in moderate dysplasia, 7.5 in mild dysplasia, 6.4 in condylomas and 3.2 and 2.9 in normal exocervical and endocervical epithelia respectively. There were significant differences in the number of nucleolar organizer regions between normal and abnormal tissues and between the different lesions except between moderate and mild dysplasia and between carcinoma in situ and moderate and severe dysplasia. The highest number of nucleolar organizer lesions was always observed in the basal strata of both normal and abnormal tissues. It is concluded that nucleolar organizer regions are a good index of cellular proliferation in uterine epidermoid cervical carcinoma and its precursor lesions, and have a diagnostic value in infiltrative carcinoma.

Analysis of Variance↗
PubMed1993

[Mutagen extraction from bile of patients with inflammatory biliary pathology: Ames test using blue rayon].

Gallbladder carcinoma is frequent in Chile. The aim of this study was to report the mutagenicity of whole human bile, using the Ames/Salmonella microsome assay with Salmonella typhimurium TA98. The bile of 19 patients, aged 23 to 64 years old, subjected to cholecystectomy was examined, and mutagen activity was found in 13 (72%). Mutagens were extracted using blue rayon and three dilutions for the eluted material from blue rayon were used (50, 100 and 200 ul). The best result was obtained using 200 ul. In some cases, the amount of revertive colonies was very high (over 5 times the control value). We propose that the bile from these patients possibly contains mutagenic substances with frame shift mutagenic activity and that these substances may be related to gallbladder carcinoma. Our results have addressed the importance of bile studies to elucidate the pathogenesis of gallbladder carcinoma.

Adult↗
PubMed1993

[Epithelial lesions associated with gallbladder carcinoma. A methodical study of 32 cases].

Using mapping techniques, 32 consecutive gallbladder carcinomas diagnosed in our department were studied. The defined lesions were dysplasia, carcinoma in situ and superficial spreading carcinoma. A total of 2257 lesions were recorded from 1072 inclusions. All the defined lesions were present in about 10% of all sections. However, if each case is considered separately, dysplasia was present in 81.3% of cases, carcinoma in situ in 65.6% of cases and superficial spreading carcinoma in 68.8% of cases. An isolated focus of atypical epithelium without anatomic relation with the main tumor was demonstrated in only 3 cases and a close relation between invasive carcinoma and dysplastic lesions was observed in the remainder. Infiltration of Rokistansky-Aschoff sinuses was observed in 40% of cases. We were not able to demonstrate, on histological basis, differences between superficial spreading carcinoma and carcinoma in situ. We conclude that atypical lesions of the gallbladder are not frequently seen and that their presence must prompt the search of a carcinomatous lesion by means of serial sections of all the histological sample.

Carcinoma in Situ↗
PubMed1993

[Cervix uteri cancer: determination of DNA content by means of cytophotometry].

ADN content was measured using cytofluorometry in 31 infiltrative uterine cervical carcinomas, using 22 routine cytologic cervical spreads (18 from archives) and 9 cellular spreads obtained from the fresh surgical specimen. Results were correlated to the clinical staging and morphological parameters of the tumor. Eight samples (25.8%) were diploid and 23 (74.2%) aneuploid. Women with diploid tumors were not significantly older. No correlation was found between ADN content and clinical staging, degree of histological differentiation, degree of cervical wall infiltration or the presence of vascular tumor permeations. All the cytological spreads were adequate for the cytofluorometric study. It is concluded that a high percentage of cervical carcinomas are aneuploid and that the present technique can be applied successfully to cytological samples.

Adenocarcinoma↗
PubMed1993

[Stomach and gallbladder cancer. Analysis of cell cycle phases by means of flow cytometry].

The characteristics of the different phases of cell cycle were analyzed in paraffin embedded samples of gall bladder cancer (n = 96) and gastric cancer (n = 40). Computational programs that included Dean, Kosugi and manual methods were used. No differences in variation coefficients were observed between tumors with normal or aneuploid ADN content, with any of the employed methods. Histograms with variation coefficients over 10% were not considered. No differences were observed between the two forms of analysis of Kosugi's method; however there were differences between the manual method and Kosugi's and Dean's methods. The percentage of cells in G0/G1 phase varied between 74.1 and 81.5% according to the employed method. The obtained percentages with Kosugi's method with normal distribution were significantly lower in all the studied groups. These percentages fluctuated between 79.7 and 94.4% in tumors with normal ADN content and between 60.3 and 80.4% in tumors with abnormal ADN content. The proportion of cells in phase G2/M was lower and in phase S lower and more homogeneous among diploid compared to aneuploid tumors. These differences were observed only in primary tumors and not in metastases.

Aneuploidy↗
PubMed1993

[Determination of DNA content by means of cytophotometry. Technical and methodological considerations and its application in tumor pathology].

The cytofluorometric determination of ADN content in tumoral cells from 33 tumors is reported. Twenty five epithelial (2 benign and 23 malignant) and 8 non epithelial tumors (1 benign and 7 malignant) were studied. All the benign tumors had a normal ADN content (2c); on the other hand, 65% of malignant tumors had an abnormal ADN content. All non epithelial malignant tumors were aneuploid. Among aneuploid tissues, epithelial tumors were frequently tetraploid (4c) and non epithelial tumors were frequently polyploid 6c, 8c, 12c). It is concluded that this technique gives valuable information about the biological characteristics of tumoral cells and that its results could be incorporated to the routine anatomopathological study of tumoral lesions.

Aneuploidy↗
PubMed1992

Gallbladder cancer in Chile. A report on 54 potentially resectable tumors.

Fifty-four patients with potentially resectable gallbladder tumors, chosen from 205 cases diagnosed at the Pathologic Unit of the authors' institution, were included in a prospective protocol of management. Of the potentially resectable tumors, only four were indicated before cholecystectomy (7.4%). Inconspicuous tumors were frequently observed, explaining in part the poor results of ultrasonogram for diagnosis. Poorly differentiated tumors were related to a greater rate of metastasis and shorter survival. Likewise, younger patients were associated with a worse prognosis. Patients with tumor confined to the mucosal layer were followed-up only during their postoperative courses. Patients with tumor involvement of the subserosa or muscular layer were offered treatment of a second operation, which included a lymphadenectomy and a liver wedge resection. For patients with serosal involvement, a more aggressive approach was proposed. Metastatic lymph node involvement was found in 9 of the 25 (36%) patients in whom dissection was performed. However, tumor invasion of the liver was seen in 10 of the 24 (41.6%) patients who underwent a liver resection. Patients who had a curative resection had a significantly longer survival in comparison with those who had a palliative resection or simple cholecystectomy.

Adenocarcinoma↗