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Biomedical subjects

J Lechago

Publications and source records attributed to J Lechago.

At least 73 records · Page 4Linked to original sources
PubMed1981

Abnormal aminopyrine metabolism in patients with chronic hepatitis.

Aminopyrine metabolism was studied by the aminopyrine breath test in 21 control subjects, 24 patients with untreated chronic active hepatitis (CAH), 4 patients with treated CAH and 17 patients with chronic persistent hepatitis (CPH). Aminopyrine breath tests gave abnormal results in 20 of 24 patients with untreated CAH. Findings were normal in all patients with treated CAH or with CPH. This test may be helpful in discriminating between CAH and other forms of chronic hepatitis.

Adult↗
PubMed1979

Physiological and morphological characteristics of progressive disruption of the canine gastric mucosal barrier.

The investigation had two major goals: to define the progression of physiological changes associated with disruption of the gastric mucosal barrier to sodium and hydrogen and to identify the morphological correlates of the physiological alterations. Fluxes of ions and water were determined before and after treatment of oxyntic mucosa with graded concentrations of butyric acid using dogs with gastric pouches. Three phases of barrier disruption were characterized: I, acceleration of normal Na+/H+ exchange; II, neutralization of H+; III, exudation of interstitial fluid. Parallel studies assessed morphological damage associated with these phases. In Phase I, cellular bulging into the lumen and dilation of intercellular spaces were evident. Some cellular erosion and extreme intercellular dilation were prominent in Phase II. Phase III was represented by necrotic changes and desquamation. It is concluded that disruption of transport mechanisms occurs sequentially and is closely correlated with morphological signs of progressive damage.

Animals↗
PubMed1979

Simultaneous visualization of two antigens in the same tissue section by combining immunoperoxidase with immunofluorescence techniques.

A simple method was developed whereby immunoperoxidase and immunofluorescence techniques were applied in consecutive steps to demonstrate the presence of two antigens in the same tissue section. This method was applied in three model, two antigens were shown: a) each (gastrin and pepsinogen II) inside one of two different cell types (gastrin (G) and antral peptic cells), b) each (kappa or gamma light chains) inside different cells of the same type (plasma cells); also, both (kamma and gamma light chains) inside the same cell (Reed-Sternberg cell), and c) both (pepsinogen I and II) inside the same cell (chief cell of oxyntic glands). The results could be viewed and photographed either simultaneously, when the antigens were in different cells, or sequentially, when the antigens were in the same cells.

Antigens↗
PubMed1977

A restaining method to restore fluorescence in faded preparations of tissues treated with the indirect immunofluorescence technique.

We report a restainin method for restoring fluorescence in paraffin-embedded tissue sections previously treated with the indirect immunofluorescence technique. Antisera to gastrin and group II pepsinogens were used. Fluorescence was restored in completely faded sections retrived from storage files, as well as in sections that had faded partially either with exposure to fluorescence microscope illumination or after counterstaining with hematoxylin and eosin.

Fluorescent Antibody Technique↗
PubMed1977

Gastrin cell immunofluorescence in conventionally fixed and stained tissue sections.

We describe a method for visualizing gastrin cells by immunofluorescence that can be applied to tissues conventionally fixed and previously stained with hematoxylin and eosin. It results in a clear demonstration of surrounding structures. This technique permits the use of a broad of histological specimens for gastrin immunofluorescence and may also prove useful in the immunohistochemistry of other gastrointestinal endocrine cells.

Duodenum↗
PubMed1976

Cholinergic innervation of the simian oxyntic gastric mucosa.

The innervation of the oxyntic gastric mucosa was studied by light and electron microscopy in the rhesus monkey. An abundant net of acetylcholinesterase-positive nerves was seen in the lamina propria, with many slender fibers noted close to the basal lamina of the glands. Electron microscopic observation disclosed the presence of nerve fibers containing axons and varicosities in the lamina propria, often in very close proximity to the epithelial glandular cells. Nerve endings partly enveloped by a Schwann cell were occasionally seen in direct contact with a parietal cell.

Animals↗
PubMed1976

Leukoplakia of the anal canal.

Two cases of leukoplakia of the anal canal are presented, with illustrations of the typical gross and microscopic appearance. The lesions were asymptomatic, and were discovered by routine rectal examination. Histological findings included hyperkeratosis and acanthosis extending cephalad from the anal verge to the dentate line. Followup after 3 and 15 years revealed no evidence of dysplastic changes, and a review of the literature did not uncover any reported cases with dysplasia or with documented evolution to malignancy. There is little evidence that leukoplakia of the anal canal is premalignant but patients should be followed carefully, since the natural history of this rare lesion is unknown.

Adult↗
PubMed1976

Experience with jejunoileal bypass for obesity.

Fifty-eight patients less than 30 years old but who are more than 300 pounds in weight were considered for investigation of jejunoileal bypass. Thirty patients had operations, and the functioning bypass included 40 centimeters of jejunum and 10 centimeters of ileum. In 14 patients, intestinal continuity was restored by either end-to-end or end-to-side anastomosis according to random choice, and in 16 patients, end-to-end anastomoses were used. At present, the follow-up period is one to four years, and the weight loss, so far, has not been significantly related to the type of reconstruction used. Weight loss correlated possitively with the preoperative weights up to one year after operation. Also, weight loss correlated positively with the total measured length of the small intestine during the first six postoperative months, but this correlation currently is showing a trend toward negativity. Food intake decreased by 2,682+/-690 calories per day at six months after operation as a result of the bypass. Chronic acidosis was common. Results of an endocrine evaluation revealed an unexpected significant decrease in parathormone levels within the normal range. A new complication, colonic pseudo-obstruction, has occurred one year or more after operation in five patients or 17 per cent of our group. This complication is related to the intestinal anaerobic flora in proximity of the defunctionalized limb; its symptoms and signs can be alleviated by giving antibiotics or Lactobacillus to change the intestinal flora. Although 90 per cent of our patients are pleased with their progress and the results of routine evaluation corroborate their satisfaction, detailed analysis of the research data available to us revealed that only 43 per cent have had beneficial effects from a jejunoileal bypass without any of the serious sequelae. We consider jejunoileal bypass for obesity justified when carried out by interdisciplinary groups dedicated to the long term follow-up study of the patient and periodic reporting of the results. The long term future for the operation is, as yet, not completely understood, and when the conditions we have recommended are not present, we cannot currently endorse the operation.

Adult↗
PubMed1976

Immunofluorescence studies of gastric heterotopia of the small intestine in Crohn's disease.

A patient with long-standing Crohn's disease of the large and small intestine was found to have extensive gastric metaplasia of the ileum. Most metaplastic glands were of the pyloric type, but numerous oxyntic glands with parietal and chief cells were also seen. By immunofluorescence the chief cells contained both the group I and group II pepsinogens, while the pyloric gland cells contained only the group II pepsinogens. Gastric-containing or other endocrine cells were not detected in the metaplastic pyloric and oxyntic glands. The latter findings are consistent with the concept expressed by Pearse that the endocrine and exocrine cells of the gastrointestinal mucosa may originate from different precursor elements during embryogenesis.

Choristoma↗
PubMed1975

Depression of antral and serum gastrin concentration by food deprivation in the rat.

In rats fasted 4 days, immunoreactive gastrin concentrations decreased to one-third of the fed levels in antral tissue and to one-eight of the fed levels in serum. The number of antral cells that reacted with fluorescent antigastrin antiserum was also correspondingly decreased. After refeeding, serum gastrin returned to normal levels in 6 days, whereas antral gastrin concentration recovered after 9 days. Normal gastrin levels were maintained in rats fed a nutritious liquid diet over a 6-day period, whereas tissue and serum hormone concentrations decreased to low levels in rats placed on a high bulk non-nutritive diet over the same period. These results suggest that food in the gastrointestinal tract is necessary for the maintenance of normal serum and antral gastrin concentration in rats. The effect of food is most likely attributable to chemical constituents and not distention by bulk.

Animals↗
PubMed1975

Culture of Zollinger-Ellison tumor cells.

We have successfully grown six Zollinger-Ellison tumors in vitro with use of a monlayer tissue culture technique. The initial gastrin concentration in the medium varied between 0 and 100 ng per ml. Many cytoplasmic secretory granules were seen in the cells of one culture population. Gastrin secretion was stimulated by the addition of fresh medium to the culture flasks. Both the culture cells and the medium were found to contain primarily big gastrin (G-34) but smaller amounts of little gastrin (G-17) were also present. Gastrin concentration in the medium decreased with time in culture until no hormone was detected between 2 and 6 weeks, possibly because of endocrine cell dedifferentiation and an increased proportion of fibroblasts in the population.

Animals↗
PubMed1973

Staining procedures for the endocrine cells of the upper gastrointestinal mucosa: light-electron microscopic correlation for the gastrin-producing cell.

Although histochemical, immunohistochemical, and electron microscopic methods have led to the identification of a large variety of endocrine cells in the upper gastrointestinal mucosa, no conventional light microscopic technique capable of the simultaneous identification of these cells has been reported. Such a staining method would be of considerable value to the pathologist as the malfunction of the endocrine cells of the gut, which produce numerous digestive hormones and biogenic amines, is closely related to a number of clinical conditions afflicting man. In this work, after testing three different polychrome staining methods, it has been concluded that a slightly modified Herlant's tetrachrome in tissues fixed in Zenker-formol is the procedure of choice. This method allows the distinction of several different cell types in the upper gastrointestinal mucosa of man and dog and permits the easy identification of the gastrin-producing cells on a routine basis. This identification has been confirmed in the case of two patients with gastrin cell hyperplasia, seen by both light and electron microscopy. Herlant's tetrachrome has proven valuable in the screening of human as well as experimental gastrointestinal tissues and it has been found to be very suitable for recognizing gastrin-producing cell hyperplasias. The usefulness of this method is expected to increase with the establishment of further correlations between the light and electron microscopy of the endocrine cells of the gut.

Adenocarcinoma↗