Search PubMed⌕ Search

Biomedical subjects

C A Rubio

Publications and source records attributed to C A Rubio.

At least 73 records · Page 4Linked to original sources
PubMed1995

Ergonomics for industrially developing countries: an alternative approach.

The main focus of ergonomics is the improvement of working conditions and safety. Studies of workers in industrialized countries (ICs) have focused on subjects like occupational health, work physiology, biomechanics, design, and cognition. However, in industrially developing countries (IDCs), the characteristics and conditions of the worker and his workplace are different. This paper suggests an alternative approach to improve working conditions for ergonomists in industrially developing countries. Together with the ergonomic factors previously stated, this approach also considers the broader social and cultural context within which the worker and his workplace exist. The operator is regarded as a product of his socio-cultural environment. His work place (e.g. its ambience, organization, shopfloor conditions, and the state of technology) and his work practices (e.g. attitudes, behavior, ethics, and problem-solving abilities) are affected by societal conditions (like quality of training and education, technical infrastructure, and technical culture).

Culture↗
PubMed1994

"Nonspecific" erosions and ulcers of the colonic mucosa.

A total of 26 cases of "nonspecific" erosions and ulcers of the colonic mucosa are reported. The most common causes were previous abdominal irradiation or ischemic disease due to arteriosclerosis. The lesions were localized to all segments of the colon. Of the 26 cases, five (19.2%) had erosions (ie, not penetrating beyond the muscularis mucosae) and the remaining 21, ulcers (ie, penetrating beyond the muscularis mucosae). In seven of the 26 cases (26.9%) more than one ulcer was found in the same specimen. Erosions may heal completely by epithelial regeneration (ie, restitutio ad integrum) while ulcers usually heal by replacing scarring tissue. Thus, the two lesions may not be clinically synonymous. The relatively high proportion of erosions among nonspecific ulcerations of the colonic mucosa has not been previously pointed out in the literature.

Adult↗
PubMed1994

The costs of colonoscopy in patients with ulcerative pan-colitis in Sweden.

The costs of colonoscopy examinations at a hospital in Sweden were calculated in ten consecutive patients with ulcerative pan-colitis. Since colonoscopy in such patients is incomplete if not followed by microscopic study of the state of the colon mucosa, the costs of both the endoscopic and histological examinations were calculated together. The costs of the material used (disposable items, recycled items and durable items) and the wages for personnel involved (endoscopists, pathologists, nurses, laboratory technicians, secretaries and clerks) were calculated for each colonoscopic and histological examination. The mean cost per complete examination was US$223, which is moderate despite the high personnel costs in Sweden. Since the biopsy material obtained in an endoscopic examination is of value not only for conventional histological study but also for DNA analysis, periodic colonoscopy is still to be recommended in patients with long-standing ulcerative pan-colitis until new methods of cancer detection and prevention become available.

Adult↗
PubMed1994

Frequency of atypical mitosis in intestinal metaplasia of the gastric mucosa in Japanese patients.

The morphologic characteristics of the mitotic figures present in intestinal metaplasia (IM) of the gastric mucosa were investigated in 70 consecutive gastrectomy specimens from Japanese nationals. The specimens contained, in addition, early gastric cancer of intestinal type (n = 44) or of diffuse type (n = 22). The remaining 4 were recorded as mixed. One hundred or more consecutive mitoses/specimens were studied by high-power microscopy in hematoxylin and eosin-stained preparations (at x1000). A total of 7259 mitoses were recorded (mean 103.7 mitoses/case). Of these, 1089 mitoses (i.e. 19.1%) were considered as atypical according to a previous classification. The percentage of atypical mitoses was found to be unrelated to the gender, to the increasing age of the patients, to the histologic type of the adenocarcinoma contained in the specimens, or to the anatomic site (e.g. corpus or antrum or tumor proximity). Comparative studies were done with gastrectomy specimens from Swedish nationals (a population with a 4-times-lower incidence of gastric carcinoma than the Japanese). The results showed a much lower frequency of mitotic figures/specimen and only occasional atypical mitosis. Since atypical mitosis has so far been reported only for neoplastic lesions in the gastrointestinal tract, it is suggested that IM with atypical mitosis may be a genuine precancerous lesion in the gastric mucosa in Japanese subjects.

Adult↗
PubMed1994

Gastric cell phenotypes and intestinal metaplasia in Polynesian and non-Polynesian residents of New Zealand.

Previous studies have indicated that the frequency of different cell phenotypes as well as of the mucosal extension of intestinal metaplasia (IM) in the gastric mucosa varies in different geographic regions (Scandinavia, Japan, Mexico, Hawaii, and mainland U.S.A.). These variations appear to be influenced by environmental factors but not by the race of the individuals. In the present work, 241 gastrectomy specimens from the two main racial groups in New Zealand, indigenous Pacific Island Polynesians (mainly Maoris) and non-Polynesian settlers (mainly of European ancestry), were examined. The occurrence of histologic changes known to be influenced by the environment such as intramucosal gastric cysts, intestinal metaplasia (IM), ciliated metaplastic cells, and cells with large vacuoles were recorded. The mucosal extension of IM was classified into low IM (having one to five areas with IM in at least one of the sections) and high IM (having one area with IM in all microscopic fields in at least one of the sections or occupying entire fields in one or more sections). Polynesians with adenocarcinomas and peptic ulcers were younger than non-Polynesians. The gastric mucosa in younger Polynesians harboring an intestinal type carcinoma or a peptic ulcer differed from that of non-Polynesians; Polynesians more often had intramucosal cysts, high IM scores, or ciliated metaplastic cells at a younger age than non-Polynesians. These results suggest that the gastric mucosa of Polynesians may be exposed to environmental factors (ulcerogenic or carcinogenic) at an earlier age than the gastric mucosa of non-Polynesians in New Zealand.

Adult↗
PubMed1994

Difference in histology and size in colonic tumors of rats receiving two different carcinogens.

We investigated the histologic phenotype of experimentally induced colonic tumors in 412 rats: 300 Sprague-Dawley rats (treated with dimethylhydrazine = DMH) and 112 F-344 rats (treated with glutamic acid pyrolysate = Glu). Of the 300 DMH-treated Sprague-Dawley rats, 278 (92.6%) developed a total of 358 colonic tumors: 60 adenomas and 298 invasive adenocarcinomas. Of the 60 adenomas, 45 (75.0%) were exophytic adenomas and the remaining 15 (25.0%) were flat adenomas. Of the 298 adenocarcinomas, 82 (27.5%) were exophytic adenocarcinomas arising in exophytic adenomas, 39 (13%) were flat adenocarcinomas originating in flat adenomas (n = 38) or intramucosal (n = 1), 90 (30.2%) were lymphoid-associated adenocarcinomas (LAC), arising in lymphoid-associated mucosa, and the remaining 87 (29.2%) were overt adenocarcinomas (usually signet-ring cell type carcinomas). In contrast, among the 112 Glu-treated F-144 rats, 62 (55.3%) developed a total of 63 colonic tumors: 52 adenomas and 11 adenocarcinomas. All 52 adenomas were exophytic adenomas and all 11 adenocarcinomas were exophytic tumors originating in exophytic adenomas. No flat neoplastic lesions or LAC were found. Glu-tumors were located predominantly in the cecum and in the right colon and were either tubular adenomas or tubular adenocarcinomas. In contrast, the tumors in the cecum and in the right colon in DMH-treated rats were usually LAC of signet-ring cell type. Neither flat adenomatous lesions (flat adenomas or flat adenocarcinomas) nor LAC were recorded in F-344 rats treated with Glu. The colonic adenomas found in the F-344 rats attained a huge size (when compared with those seen in DMH-treated rats). While the cause(s) of the difference in the histologic phenotypes and their localization as well as of the difference in the size of the tumors between the two experimental groups remains unclear, it is conceivable that Glu binds, mutates, suppresses, or interacts with oncogenes in colonic epithelial cells in a different fashion than DMH. A review of the literature indicates that the genetic differences in the two strains of rats used in the present work may not account for the difference in the results obtained.

Adenocarcinoma↗
PubMed1993

Liver fibrosis quantified by image analysis in methotrexate-treated patients with psoriasis.

BACKGROUND: Histopathologic monitoring of the liver is mandatory during methotrexate (MTX) treatment. Fibrosis is an important histologic feature of liver damage. OBJECTIVE: Our purpose was to supply an independent measure to histopathologic grading of hepatic changes in MTX-treated patients with psoriasis. METHODS: Forty-six liver biopsy specimens from 26 patients with psoriasis evaluated for or treated with MTX were histopathologically classified and their collagen content quantified by image analysis after staining with Sirius Red F3BA. RESULTS: Fibrosis in normal liver biopsy specimens (controls) amounted to 0.9% +/- 0.1% and in patients with psoriasis varied between 9.3% +/- 1.4% and 24.0% +/- 4.9%. An effect of MTX on liver fibrosis was not discerned. No correlation was obtained between fibrosis and histologic grades, intake of alcohol, lean tissue mass, or age of the patient. CONCLUSION: Two changes occurred in the psoriatic liver; the collagen content was increased at least tenfold when compared with controls, and significant heterogeneity in collagen content was present among patients (p < 0.001).

Adult↗
PubMed1993

Atypical mitosis in gastric intestinal metaplasia in Japanese patients.

The characteristics of the mitotic figures occurring in intestinal metaplasia of the gastric mucosa were investigated in 50 consecutive gastrectomy specimens. The specimens contained, in addition, early gastric cancer of intestinal type (n = 38) or of diffuse type (n = 12). One hundred or more consecutive mitoses/specimen were studied by high-power microscopy (x 1000). Of the 5,140 mitoses, 1,030 (i.e. 20.0%, range 8-34%) were considered as atypical according to a previous classification. The presence of atypical mitosis was not influenced by the gender or age of the patient, or the histological type of the tumor present in the specimen. Studies of gastrectomy specimens from Swedish patients with early gastric cancer showed a much lower frequency of mitotic figures/specimen and occasional atypical mitosis. The high frequency of atypical mitosis in intestinal metaplasia in the gastric mucosa of Japanese nationals may mirror a profound genetic instability in that mucosa, and suggests that intestinal metaplasia with atypical mitosis may be a precancerous lesion in the Japanese.

Female↗
PubMed1993

Gastric intestinal metaplasia eleven years after randomized selective proximal vagotomy for peptic ulcer.

The presence of intestinal metaplasia (IM) 11 years after selective proximal vagotomy (SPV), selective proximal vagotomy with pyloroplasty (SPV + PP) and selective vagotomy with pyloroplasty (SV + PP) was investigated in 38 consecutive patients. IM was significantly more frequent in SPV than in SV + PP, SPV + PP or in unoperated controls of matching ages. IM occurred more frequently both at an older age (> or = 60 years) in SPV and in a larger number of gastric areas than in the other group of patients. Reports in the literature indicate that vagotomy may increase the risk of gastric carcinoma and that IM may antedate malignant transformation. It would thus appear that patients previously operated with SPV (without pyloroplasty) having IM, should be the group of patients to be enrolled in endoscopical surveillance programs for detection of possible cancer development.

Adult↗
PubMed1992

Normal colon of Sprague-Dawley rats. An immunohistochemical study.

The patterns of expression of the human-tumor-associated antigens, CO17-1A, GA73-3, BR55-2, GICA19-9, CA50 and carcino-embryonic antigen (CEA) were studied in the normal colonic mucosa (the last three also in the serum) of Sprague-Dawley rats. Four immunohistochemically different segments were identified: caecum, ascending colon, transverse colon and descending colon. The immunohistochemical reactions of the cells at the lower part of the crypt were essential for the distinction of the four segments. In the caecum, the MAbs 17-1A, 73-3 and 19-9 stained the glycocalyx of the cells of the lower part of the crypts and the Golgi apparatus of the intercalated cells (IC). MAb55-2 stained very weakly the goblet-like cells (GLC) of the lower part of the crypt of transverse colon, in addition to a nearly complete lack of reaction in the upper part of the crypts. In the ascending colon, the lower part of the crypts showed a characteristic diffuse staining of the intercalated cells with MAb55-2. The perinuclear and mucosal staining observed in the GLC of the transverse colon with MAbs 17-1A, 73-3 and 19-9 as against the supranuclear and Golgi zone staining observed in the GLC/goblet cells (GC)/columnar cells (CC) of the lower part of crypts of the descending colon with the same MAbs, distinguished the former segment from the latter. The IC demonstrated by immunohistochemistry in the lower parts of the crypts of caecum and ascending colon appear to correspond to the replicating cells of the colonic crypts.

Animals↗
PubMed1992

Five types of pyloric cells in the antral mucosa of the stomach.

Only one type of pyloric cells in the exocrine antral glands is usually described in the literature. The review of 100 gastrectomy specimens revealed 5 types of pyloric cells: one composed of "ordinary" pyloric cells (i.e. cuboidal cells with ill-defined borders, pale, bubbly cytoplasm with an inconspicuous cytoplasmic network). The second type was characterized by pyloric cells with a small, regular vacuole, usually in a subnuclear position. The vacuole in such cells was negative for mucous stains. The third type of pyloric cells had a large intracytoplasmatic vacuole. Cells with this characteristic were found in cystically dilated pyloric glands. The vacuoles in such cells were usually negative for mucous stains although a rim of PAS or alcian blue positive substance was found in some vacuoles. The fourth type of pyloric cells had eosinophilic granules in the cytoplasm. These granules were proven to contain lysozyme. The fifth type had a non-vacuolated, homogeneous ("glassy") cytoplasm which was weakly positive for PAS but negative for acid mucins or mannosides. While the significance of the various types of pyloric cells herein described remains unclear, their easy identification in H & E stained preparations would permit more elaborated studies with histochemistry, immunohistochemistry and/or transmission electron microscopy in the future.

Cytoplasm↗
PubMed1992

The characteristics of mitotic figures in jejunal mucosa of patients with celiac disease.

The morphologic characteristics of the mitotic figures present in the jejunal mucosa of 23 pediatric patients having gluten enteropathy were recorded. Of the 851 mitoses found, 4.9% were in prophase, 39.9% in prometaphase, 29.5% in metaphase, 22.3% in anaphase, and 3.3% in telophase. Of the 851 mitoses found, 98.8% were considered to be morphologically normal and the remaining 1.2% were considered atypical. The occurrence of atypical mitoses in the jejunal mucosa of pediatric patients was unexpected. However, because jejunal adenocarcinomas in celiac patients are known to be rare, the plausible explanation for the present findings is that the occurrence of atypical mitoses may mirror morphologic variations from the normal mitotic pattern occurring in a rapidly proliferating mucosa, such as that of patients with gluten enteropathy.

Celiac Disease↗
PubMed1992

Low frequency of intestinal metaplasia in gastric biopsies from Mexican patients: a comparison with Japanese and Swedish patients.

A systematic analysis of the cellular and structural components of intestinal metaplasia (IM) was carried out in 691 consecutive endoscopic gastric biopsies from Mexicans patients. Two-thirds of the patients (461 or 66.7%) had chronic gastritis, 27.6% (or 191 patients) had gastric ulcers and 5.6% (39 patients) gastric carcinomas. IM was found in 17.4% of the gastric biopsies. While IM was present in 27.7% of patients with gastric peptic ulcer, patients with gastric malignancy had only 18.7%, and the lowest rate (13.4%) was found in 461 biopsies from patients with chronic gastritis. IM was influenced by the age but not by the sex of the patients. Only one of 120 biopsies with IM (0.8%) had incomplete IM (a lesion claimed to be a precursor of gastric carcinoma). In a previous study it was found that 32.3% of 359 Swedish patients and 59.2% of 625 Japanese patients with chronic gastritis had IM, the proportion of incomplete IM being 23.3% and 25.1%, respectively. The low frequency of IM among Mexicans (a population with a low incidence of gastric carcinoma), contrasts with the moderate frequency of IM among Swedes (who have a moderate gastric cancer incidence) and with the high frequency of IM among Japanese (with a high incidence of gastric carcinoma). These findings recorded in disparate geographical regions strongly support the view that IM is a lesion evoked by environmental factors and associated with gastric carcinogenesis.

Adult↗
PubMed1992

Quantitation of gastric intestinal metaplasia by morphometry in Japanese patients.

With the aid of an image processor, the length of the intestinal metaplasia (IM) was recorded in 33 gastrectomy specimens (23 with early gastric cancer and 10 with gastric peptic ulcer). A total of 1917 sections were analyzed. The length of the areas with IM and the total length of the muscularis mucosa were measured in individual sections. The resulting ratio (length of IM/length of muscularis mucosa) was noted as the intestinal metaplasia index (IMI), as an expression of the extension of IM in the specimens. The IMI was influenced by the age of the patient and by the histologic type of the tumor: a higher IMI was found among older patients and among patients with adenocarcinoma of intestinal type. A comparison with a similar study done in gastrectomy specimens from Swedish patients indicates that despite the latter group being older, and the tumors being more advanced, the IM was much more extended in the gastric mucosa of the Japanese patients with gastric adenocarcinomas of intestinal type. From the results it is suggested that extended IM in the gastric mucosa may have some bearing on the histogenesis of gastric carcinomas, particularly adenocarcinomas of intestinal type.

Adenocarcinoma↗
PubMed1992

Eosinophilic bodies in pyloric and Brunner's gland cells.

A previously unreported cell phenotype occurred in the pyloric and Brunner glands in two gastrectomy specimens. The cells were characterised by homogeneous, eosinophilic material in the cytoplasm. The eosinophilic material had an abnormally strong reactivity for Cystatin C, a protein found recently in the normal secretion of pyloric and Brunner's gland cells. The reason for the apparent cytoplasmic accumulation of cystatin C in the two patients described remains unclear.

Brunner Glands↗
PubMed1991

Barrett's mucosa in conjunction with squamous carcinoma of the esophagus.

Fifty esophagectomies (32 specimens with squamous cell carcinoma and 18 with adenocarcinoma) were reviewed for the presence of Barrett's mucosa. The whole resected specimens were cut, and a total of 1677 blocks (measuring up to 4.0 x 0.5 cm) were obtained. In resections with squamous cell carcinoma, a mean of 33.6 sections (range, 16 to 55 sections) were excised, and in those with adenocarcinomas, a mean of 33.4 sections (range, ten to 60 sections) were cut. Barrett's mucosa (without or with dysplasia) was present in all 18 specimens with an adenocarcinoma (100%) and in 13 of the 32 specimens (40.6%) with squamous cell carcinoma. In ten of the 13 specimens with squamous cell carcinoma, adjacent areas with high-grade squamous cell dysplasia were found. The squamous cell carcinoma and/or the adjacent squamous cell dysplasia were found separated from the Barrett's mucosa by normal squamous epithelium, supporting the view that these two lesions are not related to one another. Early clinical and experimental data showed that squamous cell dysplasia antedated the development of squamous cell carcinoma in that organ. One possible suggestive of these findings is that the detection of a Barrett's esophagus (without or with dysplasia) should prompt the endoscopist also to examine carefully the rest of the esophagus to exclude mucosal alterations possibly connected with squamous cell carcinogenesis in that organ.

Adenocarcinoma↗