Biomedical subjects

C A Rubio

Publications and source records attributed to C A Rubio.

At least 145 records · Page 8Linked to original sources

PubMed1984

Partial colon resection as a promotor of cancer growth in the rat.

Sprague-Dawley rats were treated with dimethylhydrazine (DMH) once a week for three months. After a treatment-free period of five months, they were subjected to minimal colon resection with an end-to-end anastomosis. Autopsy (one year after the discontinuation of DMH treatment, and seven months after surgery) demonstrated anastomotic tumors in 50% of the animals. Conclusions were that the carcinogen had induced genetic changes in the nonmigrating stem cells in the colonic crypts and that the chronic reparative process resulting from surgical trauma may have promoted colonic cells to induce tumors at the suture line.

Adenocarcinoma, Mucinous↗

PubMed1984

Carcinogenesis at colonic anastomotic sites. An animal study.

For three months 65 male Sprague-Dawley rats received subcutaneous 1,2-dimethylhydrazine (DMH) weekly. Of the 65 animals, 45 were subjected to resection of the transverse colon, which subsequently was stitched to the abdominal wall. The remaining 20 animals were sham-operated controls. Fifty-four per cent of the tumors occurred either at the anastomotic site in the functioning colon (31 per cent) or at the anastomotic site of the isolated and defunctionalized colonic loop (23 per cent). On the other hand, only 10 per cent of the tumors occurred in the transverse colon of sham-operated controls. The difference was significant (P less than 0.001).

1,2-Dimethylhydrazine↗

PubMed1984

Villous dysplasia. An ominous histologic sign in colitic patients.

Preoperative biopsies and colectomy specimens from 40 patients with long-standing ulcerative colitis (of whom 20 had adenocarcinoma at colectomy) were searched for the presence of villous adenomatous changes with or without cellular dysplasia. Villous adenomatous changes were found in available preoperative punch biopsies in nearly 70 per cent of the patients with carcinoma, but in none of the preoperative punch biopsies from the 20 patients without cancer. Only three of the preoperative biopsies from patients with carcinoma showed severe dysplasia, and also one of the 20 colitic patients without carcinoma. The mucosal tip in villous adenomatous changes was usually covered by columnar epithelium without dysplasia. In preoperative punch biopsies from patients with long-standing ulcerative colitis, the presence of structures compatible with villous adenoma--even those without cellular dysplasia--should be considered an ominous histologic sign and, thus, an indication for panproctocolectomy.

Adenoma↗

PubMed1984

Ectopic colonic mucosa in ulcerative colitis and in Crohn's disease of the colon.

Colectomy specimens from 62 patients (22 with ulcerative colitis, 20 with Crohn's disease of the colon, and 20 with invasive adenocarcinoma [without inflammatory bowel disease]) were reviewed for the presence of ectopic colonic mucosa. One or more foci of ectopic colonic mucosa were found in 16 of the 22 specimens (72 per cent) with ulcerative colitis and in 11 of the 20 specimens (55 per cent) with Crohn's disease of the colon. None of the 20 specimens having adenocarcinoma (without chronic inflammatory bowel disease) had ectopic colonic epithelium. The presence of ectopic colonic mucosa was found to be dependent on the age of the patients (more frequent among younger patients) and on the number of sections per specimen. One adenocarcinoma in a case of long-standing ulcerative colitis had apparently originated in ectopic colonic mucosa.

Adolescent↗

PubMed1984

The intramucosal cysts of the stomach. VI. Their quantitative and qualitative characteristics in focal (elevated) neoplastic lesions.

The topographical position of the atypical epithelium replacing the lining of intramucosal gastric cysts was systematized in 88 Japanese resected stomachs having focal (elevated) neoplastic lesions. In the majority of lesions (87.5%) the atypical epithelium had replaced part of the luminal aspect of the cysts, suggesting that the replacement of the cysts by the atypical epithelium followed a downwards direction (i.e. towards the muscularis mucosa). Micrometric determinations indicated that the intramucosal cysts were larger beneath focal (elevated) neoplastic lesions than in the adjacent non-neoplastic gastric mucosa, suggesting that the cause (s) responsible for the retention of secretion had been present for a longer time in the former lesions. In some cysts, clusters of atypical cells or papillary formations with atypical cells were present at the narrowest part of the outlet from the glands, substantiating an obstructive-causal mechanism in those cysts.

Cysts↗

PubMed1984

A quantitative method of estimating inflammation in the rectal mucosa. IV. Ulcerative colitis in remission.

Histological preparations of the rectal mucosa were analyzed quantitatively in 61 patients with ulcerative colitis in remission (UCR). Four histological variables were recorded: the diameter (minor axis) of the lumen of 10 consecutive (transversally cut) glands, the interglandular linear distance between 10 consecutive glands, the number of glands at high-power field examination, and the number of nuclei in 10 consecutive areas of lamina propria. The most important feature to differentiate UCR patients from non-colitic patients was the distance between glands and the number of glands per area. The sum of the values of the four variables demonstrated that 84% of the patients with UCR had scores of 22 or more, whereas only 1 of 124 non-colitic patients (that is, 0.8%) had similar scores.

Cell Count↗

PubMed1984

Antitumoral activity of indomethacin on experimental esophageal tumors.

The effect of treatment with indomethacin on diethylnitrosamine (DENA, CAS:55-18-5; N-nitrosodiethylamine)-induced esophageal tumors was investigated in 128 C57BL mice. The number of DENA-induced esophageal tumors was significantly reduced when indomethacin was given together with DENA from the outset, suggesting that indomethacin may prevent the induction of esophageal tumors in the C57BL mouse. Similarly, esophageal tumors were significantly reduced when indomethacin was given 4 months after DENA treatment, suggesting that the delayed indomethacin administration may inhibit the further appearance of additional esophageal tumors in the C57BL mouse.

Animals↗

PubMed1983

Studies on the distribution of abnormal cells in cytologic preparations. VI. Pressure exerted by the gynecologist during smearing.

A model system consisting of exfoliated abnormal cells and acellular viscous, mucus-like material was used to investigate the effect of the pressure exerted during smearing on the number of abnormal cells present in the preparations. Smears were made with a cotton swab applicator from left to right with parallel strokes, without overlapping smearing and without rotating the instrument of cell collection. Light and heavy pressures done during smearing procedure were recorded by the aid of an automatic scale. By means of the smearing technique, a gradual decrease in the total number of cells was recorded along the pathway of smearing. By using heavy pressure, however, cell accumulation also occurred at the end of the pathway of the last smearing strokes. Smears made with heavy pressure contained 13% more tumor cells than those made with light pressure. It is concluded that the pressure exerted by the operator during smearing may be an important parameter influencing both the number and the distribution of abnormal cells on smear preparations. These considerations may be of significance in screening programs for tumor cell detection.

Animals↗

PubMed1983

Epithelial lesions antedating oesophageal carcinoma. I. Histologic study in mice.

The histological changes occurring in the oesophageal mucosa after protracted topical treatment with diethylnitrosamine was investigated in 87 C57B1 mice. The histological changes were classified into slight, moderate, severe dysplasia, carcinoma in situ, questionable invasive carcinoma and invasive carcinoma. Starting from moderate dysplasia, the epithelial-stroma border became irregular with formation of buds bulging into the stroma. Similar histological changes have been found in the same strain of animals during carcinogenesis of the cervix uteri, another organ covered by squamous epithelium. The findings strongly suggest an association between the degree of cellular atypia, the formation of epithelial buds and progression towards invasive carcinoma.

Animals↗

PubMed1983

Classification of intramucosal cysts of the stomach.

The occurrence of intramucosal cysts in the mucosa of resected stomachs was recorded in 91 consecutive patients having synchronous focal (elevated) dysplasia and/or adenocarcinoma elsewhere in the stomach. Intramucosal cysts were classified into foveolar cysts, pyloric gland cysts, fundic gland cysts, intestinal metaplastic cysts and ciliated-cell cysts. The most common type was intestinal metaplastic cyst, which was present in 60% of the patients.

Adenocarcinoma↗

PubMed1983

The intramucosal cysts of the stomach. III. In Japanese subjects with gastric or duodenal ulcers.

Gastrectomy specimens from 102 Japanese patients with peptic ulcer disease were examined for intramucosal cysts. The number of cysts for each centimeter of mucosa analyzed (cyst index) was calculated. The intramucosal cysts occurred in 90% of the patients. The mean number of cysts in the 102 specimens was 12.3 (SD +/- 23.45). The resulting cyst index was 3.4 (SD +/- 6.6). Earlier studies have demonstrated a significantly lower cyst index in Swedish patients with peptic ulcer disease. A significantly higher cyst index was found in Japanese and Swedish patients with focal elevated dysplasias and in patients with early gastric cancer. The possibility that some intramucosal cysts of the stomach may be symptomatic of lesions antedating malignant transformation in that organ has been discussed.

Adult↗

PubMed1983

Ectopic intestinal glands after segmental small bowel irradiation in the cat.

Following segmental irradiation of the small bowel, 5 of 64 cats demonstrated ectopic intestinal glands in the submucosal tissue. In addition, one of these 5 cats had foci of abnormal glands in the muscularis mucosae. In 2 of the 5 animals, cellular polymorphism, nucleolar irregularity and loss of cellular polarity were present in irradiation-induced ectopic intestinal glands. The review of the literature indicates that intestinal irradiation may induce intestinal adenocarcinomas with metastatic growth. The possibility that ectopic intestinal glands are precancerous lesions in the irradiated cat is discussed.

Animals↗

PubMed1983

The intramucosal cysts of the stomach in Japanese subjects having focal (elevated) dysplasia.

The frequency of intramucosal cysts underneath focal (elevated) neoplastic lesions (which include epithelial dysplasia and early gastric cancer) was recorded in eighty-eight resected stomachs. The mean cyst index (i.e. the amount of intramucosal cysts divided by the amount--in cm--of gastric mucosa analyzed) underneath such lesions was 30.9 (SD +/- 16.9), while in adjacent normal-looking gastric mucosa it was 9.4 (SD +/- 8). The difference was significant (P less than 0.001). The cyst index was highest in female patients, underneath focal (elevated) dysplasias. Previous work indicated that the normal-looking gastric mucosa in Japanese patients with peptic ulcer disease was 3.4 (SD +/- 6.6). The present findings appear to suggest that cystic formation in gastric mucosa may herald an early neoplastic growth at the luminal aspect in some of the cysts.

Age Factors↗

PubMed1982

Non-dysplastic villous changes in endoscopic biopsies in ulcerative colitis with carcinoma.

Three cases of long-standing ulcerative colitis and invasive adenocarcinoma are described. In all three cases, pre-operative rectal and/or colonoscopic biopsies demonstrated the presence of a villous adenoma: two without dysplasia and the third with moderate dysplasia. The presence of structures compatible with villous adenoma should be, even in the absence of epithelial dysplasia, an indication for panproctocolectomy in patients with long-standing ulcerative colitis.

Adenocarcinoma, Mucinous↗

PubMed1982

The histological classification of early gastric cancer (micro-invasive carcinoma of the stomach).

During a 3.5-year period, January 1976 to June 1979, eleven cases of micro-invasive carcinoma of the stomach (early gastric cancer) were detected in 45 gastrectomy specimens having a pre-operative diagnosis of gastric carcinoma. The histological types found in the surgical specimens were highly differentiated (1), moderately differentiated (4), poorly differentiated (3) adenocarcinomas, one specimen had undifferentiated carcinoma, and in the remaining two cases mixed types were found. Multiple lesions were present in five specimens. In ten of the eleven specimens, focal cystic dilatation of the deeper part of the gastric glands were found in areas overlapped by micro-invasive carcinoma and/or in areas overlapped by mucosa showing chronic inflammation. The frequency of cystic dilatation of the gastric gland was much lower in specimens from patients with gastric or duodenal peptic ulcers. Thus, focal cystic dilatation present in negative gastric biopsies should be reported, thereby alerting the referring physician as to the possibility of a gastric malignancy.

Adenocarcinoma↗

PubMed1982

The intramucosal cysts of the stomach. II. Late glandular changes after partial gastrectomy.

Micrometric determinations of the diameter of the gastric glands, of the linear distance between those glands, and of the number of chronic inflammatory cells were performed on gastric biopsies from 71 patients. Forty of the patients had been operated on with a Billroth II and 12 with a Billroth I gastrectomy 5-45 years previously. The mean diameter of the gastric glands was significantly larger for patients with a Billroth II gastrectomy than for those of the Billroth I group or for non-operated control patients with chronic gastritis. The difference was marked for Billroth II patients operated on 26 or more years previously. Contrariwise, the linear distance between glands was significantly smaller in Billroth II patients than in the other two groups. The number of inflammatory cells was somewhat lower in biopsies from operated patients than in controls. The significance and pathogenesis of dilated gastric glands in long-time Billroth-II-gastrectomized patients (a high-risk group for cancer development in the gastric stump) is discussed.

Biopsy↗

PubMed1982

Surgical resection of the rat colon: effects on carcinogenesis by 1,2-dimethylhydrazine.

Following a 3-month treatment with 1,2-dimethylhydrazine (DMH) given weekly (sc), outbred Sprague-Dawley rats were subjected to partial resection of the transverse colon. After surgery, DMH treatment was continued for 6 months, after which the rats were killed. At autopsy, 63% of the tumors were found in the transverse colon. By contrast, only 29% of the tumors found in the "sham-operated" control animals occurred in the transverse colon. Surgical trauma in the colon mucosa subjected to the action of carcinogenic agents appeared to promote the conditions suitable for the development of tumors in that organ.

Animals↗

PubMed1982

The intramucosal cysts of the stomach. I. In Swedish subjects with gastric or duodenal ulcers.

Gastrectomy specimens from 51 patients operated on because of peptic ulcer disease were searched histologically for the presence of intramucosal cysts. The number of cysts for each cm of mucosa analyzed (cystic index) was calculated. Intramucosal cysts occurred in 34 per cent of the patients. The resultant cystic index was 0.19 (S.D. +/- 0.40). The cystic index was not correlated to age or sex. Comparative studies demonstrated significantly higher (p less than 0.001) proportions of intramucosal cysts in the non-tumoral mucosa from patients with early gastric cancer (cystic index 3.13 - S.D. +/- 3.55). The possible association between benign intramucosal cystic dilatation of the gastric glands and the occurrence of gastric carcinoma deserves further investigation. The occurrence of intramucosal cysts in a biopsy specimen should intensify the search for an early gastric cancer.

Adult↗