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J C Araya

Publications and source records attributed to J C Araya.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1992

[Gastric cancer: epidermal growth factor and epidermal growth factor receptor].

In 19 patients with advanced gastric cancer the expression of epidermal growth factor receptor and epidermal growth factor (EGF) were studied using immunohistochemical techniques. There were 12 males and the mean age of the group was 54.8 years. Most cases belonged in Borrmann's types III or IV. Tumoral cells were positive for EGF receptor in 9 patients (47%), with a strong reaction in 6. Thirteen of 18 subjects were positive for EGF. The reaction for EGF receptor was positive in 20% of 12 patients with intestinal type tumors and in 67% of 7 patients with diffuse tumors. Reaction for EGF was positive in 80% of intestinal type tumors and 64% of diffuse tumors. Simultaneous positive reactions for both antigens was observed in 5 of 18 patients, all with diffuse type tumors. Signet ring cell tumors showed less positivity than less differentiated ones. Thus, the expression of EGF and EGF receptor was higher in our patients with advanced gastric cancer than reported elsewhere.

Adult↗
PubMed1992

[Characteristics of gastric cancer in the IX region of Chile].

The results of a prospective protocol for the management of patients with gastric cancer applied from May 1988 to June 1991 are reported. 123 patients were operated on and a resection performed in 55%. Only 14 patients had incipient tumor and 44 had "curative" surgery. There was a preponderance of non differentiated tumors located high in the stomach. Endoscopy and biopsy were performed in cases with positive diagnosis in 91 and 93%, respectively. The overall actuarial survival rate was 37% at 38 months, rising to 50% for patients undergoing resection and to 82% in patients with "curative" resection.

Adult↗
PubMed1992

[Gallbladder cancer: immunohistochemical expression of CA-19-9, epithelial membrane antigen, dupan-2 and carcinoembryonic antigen].

The immunohistochemical expression of CA19-9, epithelial membrane antigen (EMA), and carcinoembryonic antigen (CEA) was studied in 103 tissue samples of gallbladder cancer and 25 samples of non tumoral gallbladder lesions. CA19-9 and EMA were positive in over 90% of cancers and non tumoral lesions. Dupan-2 expression was observed in 100% of non tumoral lesions and 78% of cancers. CEA expression was observed in 12% of non tumoral lesions and 89% of cancers. The magnitude of immunohistochemical staining was moderate or intense for all antibodies, except Dupan-2. No differences were observed in the location of positive staining in superficial or deep parts of the tumor. In these lesions the positive staining was cytoplasmatic with a granular and irregular pattern; on the contrary, in the non tumoral lesions, staining was seen in the apical parts of the cell. Calculated sensitivity, specificity and positive predictive value for CEA was 89%, 88% and 96% respectively. If future studies disclose a good correlation between serological and immunohistochemical detection of this antigen, its determination would be potentially useful in clinical grounds.

Antigens, Neoplasm↗
PubMed1992

[Immunohistochemical demonstration of pepsinogens I and II in the gallbladder].

The immunohistochemical expression of pepsinogen I (PI) and pepsinogen II (PII) was studied in 103 gallbladder carcinomas, 25 non tumoral gallbladder lesions and 23 gallbladder cancer metastases. PI was positive in 6% of carcinomas and only in 2% of non tumoral contiguous mucosa. PII was positive in 46% of carcinomas and 43% of controls. Metastases were negative for both enzymes. Pyloric gland metaplasia of non tumoral mucosa adjacent to the tumor expressed PII in 68.9% and PI in 3.4% of cases. The same lesion in non tumoral gallbladders was positive for PII in 66.6% of cases, and no case expressed PI. There was no relationship between PI expression and the histological degree of differentiation. Only tumors with serosal or subserosal involvement were positive for PI. PII had a higher expression in early or well differentiated tumors. Tumors with pyloric gland metaplasia in the contiguous non tumoral mucosa expressed PII more frequently. Our results, based on the expression of PI and PII, suggest a relationship between the presence of pyloric gland metaplasia and some types of gallbladder cancer.

Biomarkers, Tumor↗
PubMed1991

Pilonidal disease: 25 cases treated by the Dufourmentel technique.

Twenty-five patients with pilonidal disease were treated by the Dufourmentel technique between 1984 and 1989. In this series, 18 patients (72 percent) were women and 7 (28 percent) were men (mean age, 24 years); hospital stay averaged 4 days. There were no recurrences and no reports of surgical wound infection. Diagnosis was confirmed histologically in all cases.

Adolescent↗
PubMed1991

[Immunohistochemical expression of the carcinoembryonic antigen in gallbladder cancer].

Immunohistochemical techniques using monoclonal antibodies were used to investigate the carcinoembryonic antigen (CEA) in gallbladders from 26 patients with gallbladder cancer and 26 patients without cancer, including normal mucosa, areas of pyloric metaplasia and areas identified by the presence of "clear cells". All carcinomas were strongly positive for CEA but 61% of noncancerous samples were also positive. However, only 1 of the last samples was strongly positive. According to histologic type the positivity for CEA in noncancerous samples was 6/11 in normal mucosa, 6/8 in samples with intestinal metaplasia and 1/8 in samples with pyloric metaplasia (p less than 0.05). Thus a negative reaction for CEA is 100% specific for absence of cancer. If mild reactions are disregarded, a strong reaction for CEA is 81% specific for cancer.

Antibodies, Monoclonal↗
PubMed1991

[Regeneration of gastric mucosa after endoscopic biopsy].

Eleven gastric mucosal defects produced by endoscopic biopsy in non-tumoral areas were histologically studied in gastrectomy specimens. The biopsies had been performed from one up to seven days before the operation. The base of each defect was formed by submucosa infiltrated by erythrocytes, fibrin and neutrophils, which were later replaced by small blood vessels, fibroblasts and collagen fibrils. The mucosa of the margins bowed down towards the base of the defect. This marginal mucosa showed dedifferentiation of the glandular epithelial cells, increased mitotic index and some cystic glandular structures lined by basophilic cells. The defect was progressively covered by a layer of flattened or cuboidal cells in which no mitoses were observed; their cytoplasm contained mucosubstances similar to those of the superficial epithelium of the remaining mucosa, either foveolar- or intestinal metaplastic-type. From this layer, simple gland-like invaginations to the underlying connective tissue were observed. The findings are consistent with the regenerative events described in experimental gastric ulcers in animals. The method employed may be useful to study specific aspects on the regeneration of the human gastric mucosa.

Biopsy↗
PubMed1991

[Stomach neoplasms in the IX Region of Chile: comparison of the anatomo-pathological study of lymph node emptying in 2 periods].

Complete resection of lymph nodes may help achieve a cure in patients with gastric cancer. In this paper we evaluate the yield of a careful search for lymph nodes in fresh tissue obtained immediately after resection. A mean of 42.5 nodes per gastric piece was obtained, which is significantly higher than that previously reported with examination of fixed tissue. The yield was higher for all node groups except the left para-cardial one.

Carcinoma↗
PubMed1991

[Advanced stomach neoplasms: expression of the fixation index of bromodeoxyuridine in vivo].

We studied fixation of bromodeoxyuridine by immunohistochemistry in 17 patients with advanced gastric cancer. Macroscopically, they corresponded to Borman's types III (n = 10), IV (5) I (1) and unclassified (1). 11 patients had a diffuse lesion, 5 an intestinal type lesion and 1 an epidermoid carcinoma. Positive reactions were observed in 27.7% of cells (95% CL 10-48%). No difference was observed in positivity of superficial (29%) or deep areas of the tumor (27%). Greater fixation rates were observed in patients under 50 years, of age compared to older patients. The percentage of positive reactive cells was not related to macroscopic or histologic tumor type. Greater fixation rates were observed in this series compared to those previously reported, suggesting greater proliferation rates in these patients.

Adenocarcinoma↗
PubMed1991

[Nucleolus organizer regions and ploidy pattern of DNA in stomach neoplasms].

We studied 20 gastric adenocarcinoma to determine DNA ploidy pattern by flow cytometry and nucleolar organizer regions by the colloidal silver method. There were 12 diffuse and 8 intestinal type lesions. 11 tumors were classified as diploid and 9 as aneuploid. No correlation was observed between DNA ploidy pattern and mean number of nucleolar organizer regions. The histologic type was significantly related to the number of nucleolar organizer regions (p < 0.01). Poorly differentiated lesions had significantly less nucleolar organizer regions than intestinal type lesions. Lesions with ring cells (n = 6) had similar number of nucleolar organizer regions than poorly differentiated lesions.

Adenocarcinoma↗