Search PubMed⌕ Search

Biomedical subjects

I T Beck

Publications and source records attributed to I T Beck.

At least 73 records · Page 4Linked to original sources
PubMed1979

Transition from diffuse esophageal spasm to achalasia.

A 19-year-old man first presented with clinical, radiological, and manometric features of diffuse spasm. Within a year his motility disorder progressed to "vigorous" and, finally, classic achalasia. After pneumatic dilatation and subsequent long myotomy, the features of classic achalasia disappeared and he again exhibited radiological and manometric evidence of "vigorous" achalasia. The evolution of this patient's disease provides evidence that diffuse spasm and achalasia are different stages of the same disease and lie at opposite ends of a spectrum of related esophageal motility disorders.

Adult↗
PubMed1979

The ultrastructure of blebs induced in the hamster jejunum by ethanol.

Previous light microscopic studies showed that perfusion of the hamster jejunum with 4.8% ethanol (ethanol period) in vivo produced fluid-filled subepithelial blisters (blebs) on the villi. These blebs had virtually disappeared within 45 min after the discontinuation of the ethanol perfusion (recovery period). The present study examined these ethanol-induced changes in the jejunum by scanning (SEM) and transmission (TEM) electron microscopy. TEM revealed that ethanol did not damage epithelial cells in areas where blebs were not present. In these areas the basal surfaces of the epithelial cells were attached to the basal lamina, and the lateral intercellular spaces (LIS) were open. In the areas where blebs formed, the stretched epithelial cells which covered the blebs lost their basal anchoring and so could not maintain their LIS. Both SEM and TEM indicate that there was a decrease in the quantity of glycocalyx at the surfaces of cells which covered blebs. Our findings indicate that ethanol does not directly damage epithelial cells but that the cellular damage is due to detachment over the blebs. It is likely that ethanol at first traverses the epithelial layer and then produces stasis in the villus core. Continued fluid transport by the epithelial layer in the presence of statis results in accumulation of the fluid and widely dilated LIS. With subsequent enlargement of the LIS the bases of the cells detach from the basal lamina and blebs are formed.

Animals↗
PubMed1979

Effect of ethanol on disaccharidases of hamster jejunal brush border membrane.

This study was undertaken to investigate the effect of alcohol on the activity of jejunal disaccharidases (DS). The activity of DS in a preparation of purified brush border membrane of hamster jejunum was measured in the absence and in the presence (0.8 to 6.4% wt/vol) of ethanol. To compare the effect of alcohol on DS with its action on a brush border enzyme of a different group, we also measured the activity of alkaline phosphatase (AP) under similar conditions. Ethanol depressed the activity of sucrase, maltase, and lactase in a dose-dependent and time-dependent manner, but it stimulated the activity of AP. The ethanol-induced inhibition of DS was completely reversible. Kinetic studies indicate that ethanol depressed the Vmax and increased the Km of sucrase and lactase. The Vmax of maltase also decreased, but the Km of this hydrolase was not affected by ethanol. From the results of this study it would appear that acute exposure of the jejunal brush border to ethanol depresses the DS activity of the membrane and that (because the AP was not depressed) the ethanol-induced inhibition of DS is not the result of a general inhibition of all enzymes of the brush border.

Alkaline Phosphatase↗
PubMed1978

Effect of ethanol on glucose and water absorption in hamster jejunum in vivo. Methodological problems: anesthesia, nonabsorbable markers, and osmotic effect.

We studied the effect of ethanol on glucose and water absorption in vivo. In preliminary experiments, using sodium amytal anesthesia, we found that control animals, whose jejunal segment was perfused without ethanol, required more anesthetic agent than those perfused with ethanol. Thus, to allow for unbiased comparison of the absorption data between the two groups of animals, all absorption studies were carried out on conscious restrained hamsters. We found that ethanol did not influence the permeability of the jejunum to polyethylene glycol (PEG) and meglumine diatrizoate. In addition, ethanol did not influence the time required for the onset of steady-state absorption. Using both the gravimetric and the electrical methods, we were unable to show any measurable osmotic pressure exerted by ethanol (150-1050 mM) on the hamster jejunum. In the absorption studies we found that perfusion of the hamster jejunum with five increasing concentration of ethanol (450-1050 mM) appeared to cause a concentration-dependent depression in steady-state glucose transport. Water transport was depressed only when 4.8% (1050 mM) ethanol was perfused.

Alcoholic Intoxication↗
PubMed1978

Effect of ethanol on the morphology of hamster jejunum.

In order to study the morphological effects of exposure of the jejunum to low ethanol concentrations, we perfused hamster jejunum with 2.1-4.8% ethanol. Following 45 min exposure, many of the villi developed fluid-filled blisters. To compare these findings to the effect of an inert solute at similar concentrations, we perfused hamster jejuna with mannitol. This caused necrosis of the villus tips but no blister formation. Therefore the blisters were the result of the action of ethanol. The rat jejunum was less resistant to ethanol than that of the hamster. We suggest that the initial insult of the freely permeant ethanol is deep to the epithelium, resulting in accumulation of edema under the epithelium.

Alcoholic Intoxication↗
PubMed1978

The correlation of ethanol-induced depression of glucose and water transport with morphological changes in the hamster jejunum in vivo.

Glucose and water transport is depressed in the hamster jejunum in vivo by ethanol (4.8%) which also produced fluid-filled blebs at the tips of the villi. The epithelial cells over the blebs appeared stretched and cuboidal, the lateral intercellular spaces (LIS) were no longer recognizable, and the lacteals were closed. Forty-five minutes after discontinuation of the ethanol, water transport returned to normal while glucose transport remained depressed. At this time the villus structure had returned to normal. The blebs had disappeared, the LIS were again recognizable, and their appearance and number were similar to those in the control animals. Thus, the depression of water transport correlated with the obvious structural changes caused by ethanol; however, the depression of glucose absorption is associated with some effect of ethanol not evident by routine light microscopy.

Animals↗
PubMed1977

Diarrhea.

Explore the source record for details and available documents.

Diarrhea↗
PubMed1977

On the mechanism of the inhibitory effect of ethanol on intestinal glucose and water absorption.

Experiments were performed to investigate whether the inhibitory effect of ethanol on intestinal glucose transport is related to its action on the brush border or on the ATPase-dependent sodium pump of the basolateral membrane of the enterocyte. We compared the effect of ethanol on glucose and water transport when it was added either to the mucosal or to the serosal solution of an in vitro preparation of hamster jejunum. The purpose of the addition of ethanol to the serosal solution was to mimic a situation similar to that produced when ouabain is placed on the serosal side to inhibit the ATPase-dependent sodium pump at the basolateral membrane. The presence of 450 mM ethanol (2.07%) in the mucosal solution depressed glucose and water transport by 40 and 63%, respectively, but the presence of the same concentration of ethanol on the serosal side had no effect on glucose and water absorption. These findings seem to indicate that the depressing effect of ethanol on intestinal glucose and water transport cannot be ascribed to the inhibition of the Na+, K+-sensitive ATPase-dependent sodium pump located at the basolateral membrane.

Adenosine Triphosphatases↗
PubMed1977

Normal sugar uptake in vitro by small-bowel biopsies from a patient with cholera.

We have investigated the 3-O-methyl-D-glucose (3MG) absorption by jejunal biopsies obtained from a patient with cholera. The absorption of 3MG (as measured from the determination of intracellular accumulation of this sugar) was found to occur against a concentration gradient and to be a saturable process that follows Michaelis-Menten kinetics. There was no appreciable difference in 3MG absorption between the biopsies from the normal volunteers and those from the patient with cholera.

Adult↗
PubMed1977

Methods for the study of antidiarrheal agents. Study of commonly used protective and adsorbent agents.

Several agents were employed to induce diarrhea in squirrel monkeys: (1) diarrhaogenic diets, (2) various doses of cholera toxin, (3) prostaglandin derivatives, (4) bile, (5) lactulose, (6) phenolphthalein, (7) castor oil. Kaolin, pectin, Kaopectate and placebo were used as antidiarrheal treatment. Evaluation was based on (a) frequency, (b) consistency, (c) total and dry weight of the stools, and (d) electrolyte loss. The spectrum of procedures employed appeared to be suitable for the evaluation of antidiarrheal agents of the protective and adsorbent class.

Animals↗
PubMed1977

Herpes simplex ulcerative esophagitis in a healthy subject.

A 20-year old white male developed a self-limited ulcerative esophagitis followed by a transient vesicular skin eruption due to infection by herpes simplex virus Type I (HSV-I). While herpetic esophagitis has been described previously, this case appears to be unique in that there was no concomitant serious delibitating illness or pharmacological immunosuppression. Herpes simplex Type I should be included in the differential diagnosis of unusual esophageal ulceration in otherwise healthy patients.

Adult↗
PubMed1976

A case of cholera in Kingston, Ont.

A case of cholera occurred in Kingston, Ont. in 1974 in a traveller from South Africa. Treatment, based on an understanding of the pathophysiology of cholera diarrhea and the mechanism of action of the Vibrio cholerae enterotoxin on gastrointestinal fluid loss, consisted of correcting the severe loss of fluid and electrolytes and the metabolic acidosis, as soon as the patient could tolerate taking fluids orally, further fluid replacement consisted increasingly of oral administration of glucose and saline. Tetracycline therapy was given only to shorten the duration of the acute illness.

Acidosis↗
PubMed1976

Sugar absorption by small bowel biopsy samples from patients with primary lactase deficiency and with adult celiac disease.

The present study was undertaken to compare the 3-O-methyl-D-glucose (3MG) absorption by jejunal biopsies from normal human subjects (N = 3) with that by the jejunum of the rat (N = 8) and of the hamster (N = 8), and to examine whether jejunal biopsies from normal subjects (N = 3), patients with primary lactase deficiency (N = 5) and from patients with celiac sprue (N = 5) follow the same pattern of sugar absorption as usually observed in vivo. The results indicate that under the conditions of our experiments the estimated affinity of carrier for 3MG (ie, apparent Km) in the biopsies from normal subjects did not differ significantly from that in rat or hamster jejunum. The estimated capacity of carriers for 3MG absorption (ie, Vmax) appeared to be similar in biopsies from normal subjects and in hamster jejunum, but significantly lower in rat jejunum. There was no difference in apparent Km between the biopsies from normal subjects and those from the patients with lactase deficiency. Although the Vmax for the lactase deficient patients was substantially higher than that for the normal subjects, the difference was not statistically significant. The absorption of 3MG by the biopsies from patients with celiac sprue did not follow Michaelis-Menten kinetics and was compatible with that of passive diffusion or low saturation conditions. Since the intracellular concentration of 3MG in all biopsies from celiac patients exceeded the concentration of the media, sugar transport could not have occurred by diffusion, and it is concluded that the absence of Michaelis-Menten kinetics was the result of low saturation conditions. This active transport with low saturation kinetics in patients with celiac disease suggests that in these patients not only the number of functioning carrier molecules is diminished but also the affinity of the existing carrier for sugar molecule is reduced. This situation, at least in some patients, seems to improve after treatment with gluten-free diet.

Adult↗