Search PubMedSearch

SEARCH · Search PubMed

Results for “Cecum”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Cigarette smoking and nicotine delay postprandial mouth-cecum transit time.

The acute effects of both cigarette smoking and nicotine on postprandial mouth-cecum transit were studied in 20 habitual smokers, 10 males and 10 females. Mouth-cecum transit time was measured by the breath hydrogen technique, following ingestion of a standard mixed liquid meal. Each subject was studied on four separate occasions, either (1) sham or actively smoking two standard cigarettes, commencing 20 min after the meal, or (2) chewing two placebo or nicotine tablets over a 60-min period, commencing immediately after the meal. The time of administration of these stimuli was designed to minimize the effects on mouth-cecum transit time of alterations in gastric emptying. Mouth-cecum transit time was prolonged in response to both smoking [median and interquartile range: 120 (95, 150) min vs 100 (75, 140) min, P = 0.01] and nicotine [120 (80, 170) min vs 100 (70, 140) min, P = 0.002]. No difference was observed between sexes with respect to nicotine; the effect of smoking on mouth-cecum transit time, however, was less pronounced in females compared to males [difference active-placebo: 10 (10, 20) min vs 35 (20, 60) min, P = 0.01]. We conclude that acute cigarette smoking delays mouth-cecum transit time, an effect most likely due to nicotine.

Adult

Effect of prolonged, continuous rectal distention on mouth-to-cecum and colonic transit time in pigs.

The effect of prolonged (6 h), continuous rectal distention on mouth-to-cecum and colonic transit time was studied in four unrestrained pigs. Mouth-to-cecum transit time was determined from samples of cecal efflux using the phenol red dye technique. Colonic transit time was assessed with radiopaque markers that were injected into the cecum before each trial. Rectal distention was applied 2-1/2 h before feeding, during feeding, and 3-1/2 h after feeding. No distention was applied during control conditions. Stools were collected for 48 h after marker application. Rectal distention increased mouth-to-cecum transit time (p < 0.05). Colonic transit time was also prolonged by rectal distention as shown by a significant decrease in the number of markers excreted within 36 h (p < 0.05). Rectal distention for 6 h increased colonic transit time up to 30 h following distention and prolonged mouth-to-cecum transit of a high fat liquid meal.

Animals

Anatomy of the cecum of the dwarf hamster (phodopus sungorus).

The cecal anatomy of the dwarf hamster, Phodopus sungorus, was investigated macroscopically and at the light, transmission electron microscopic and scanning electron microscopic levels. In addition, the arterial supply to the cecum and connecting mesenteries were elucidated. The cecum is divisible into an ampulla ceci and a corpus ceci. In the former, the differentiation of the ileocecal orifice and circumventing fold is described. Scanning electron microscopically, the surface topography of the cecum appears as ring-walled elevations with a central depression and looped configurations, which correlate light microscopically to a "rolling-hills" type mucosa with wide-opened crypts. This type of mucosa is set in contrast to the classically described large intestinal mucosa in man and some other mammals. The present observations are compared with descriptions made on the cecum of the common field vole, Microtus agrestis, also a myomorph but belonging to another subfamily.

Animals

Anatomy of the rabbit cecum.

The anatomy of the rabbit cecum was investigated using macroscopic dissections, vascular injections, dried total specimens, light microscopy, and scanning and electron microscopy. The morphology of the three portions of the cecum (ampulla coli, corpus ceci and appendix vermiformis) is described. For comparison, the proximal colon, ileum and sacculus rotundus were also investigated. The thickness of the different layers of the intestinal wall of each area was measured. The arterial supply and mesenteries of the cecum were also studied. The rabbit cecum represents structurally a highly developed organ.

Animals

Hormonal and pharmacologic regulation of sodium absorption in rabbit cecum in vitro.

The rabbit cecum is a moderately tight epithelium with amiloride-resistant but phenamil-sensitive electrogenic Na absorption. We performed flux and electrical studies under short-circuit conditions in vitro to further characterize the mechanisms of ion transport in cecum in normal and animals pretreated with methylprednisolone (MP) and deoxycorticosterone acetate (DOCA). MP treatment increased Na absorption and decreased tissue conductance. In contrast, DOCA increased Isc but did not significantly alter Na or Cl fluxes. Amiloride analogs with primary specificity for Na channel and Na/H exchanger both inhibited Isc and Na absorption. Ethacrynic acid, but not bumetanide, inhibited Isc. Nystatin and amphotericin B increased Isc. We conclude that: (1) Steroids have a differential effect on cecal ion transport; methylprednisolone increases Na absorption, but DOCA does not. (2) The response to amiloride analogs is different from other electrogenic transport systems, suggesting a distinct mechanism of Na transport in cecum. (3) The effect of ethacrynic acid was unexpected, suggesting an inhibitory response on an alternate transport system. (4) The effects of polyene antibiotics are similar to those found in other tight epithelia. Electrogenic Na absorption in rabbit cecum represents a distinct transport system, significantly different from Na absorptive mechanisms in other segments of the gut.

Amiloride

Carcinoma of the cecum.

During the ten year period of this retrospective study, 66 of 1,451 patients with carcinoma of the colon and rectum had carcinoma of the cecum. The most frequent symptoms were nonspecific and caused by anemia which, in some instances, were treated without adequate investigation. The standard and most appropriate treatment for carcinoma of the cecum is a right hemicolectomy with ileotranversostomy and, when necessary and feasible, en bloc resection of involved parts of the abdominal wall. In the absence of nodal disease or distant metastases, extension to the abdominal wall does not adversely influence the prognosis. The surgeon must remain aware of the possibility of coexisting carcinoma of the cecum and appendicitis. Any patient with a mass or a persistent draining sinus after an appendectomy or drainage of an appendical abscess should be suspected of having carcinoma of the cecum. The over-all five year survival rate in this series is 33%, and if curative resections alone are considered, it is 44%, with an operative mortality of 3%. More recent evidence indicates that there has been a shortening of the delay in treatment, and we believe future studies will show an improvement in these figures.

Adenocarcinoma

Induction of Na-K-ATPase in plasma membranes to rat cecum mucosa by diet: time course and kinetics.

Dietary polyethylene glycol (PEG) induces an increase in the specific activity of Na+-K+-activated adenosine triphosphatase (Na-K-ATPase) in the cecum mucosa of rats. Using cecum mucosa homogenates and cellular subfractions obtained by differential centrifugation, the induction process was studied with respect to time course, subcellular distribution and properties of the enzyme. In comparison with controls, Na-K-ATPase specific activity was stimulated in PEG treated rats in the total homogenate and the microsomal (105000 X g) but not in the mitochondrial (9000 X g) or nuclear (1000 X g) sediment. The specific activity of Mg-ATPase did not change in any of the fractions. Na-K-ATPase induction was statistically significant after 2 days and complete after 1-2 weeks, in parallel with the previously described stimulation in net sodium absorption. Kinetic analysis showed Vmax for ATP to be doubled while Km for ATP, Na and K as well as the optimal Mg/ATP ratio and Ki for ouabain remained unchanged. It is proposed that Na-K-ATPase and active sodium transport are closely associated in rat cecum and that dietary Na-K-ATPase stimulation is due to the induction of more enzyme molecules per unit basolateral cell membrane.

Adenosine Triphosphatases

What is the optimal depth for core-out toward the foramen cecum in a thyroglossal duct cyst operation?

The high recurrence rate of thyroglossal duct cyst operations is well documented. Sistrunk's operation is widely accepted as the best procedure to prevent recurrence. Nonetheless, the optimum depth of core-out is still not well documented. We previously reported a standard running pattern of the thyroglossal duct in an anatomical reconstruction study. In more detailed pathological studies, we have tried to determine the optimal depth for core-out toward foramen cecum and the optimal width of the hyoid bone to be resected. The following items were clarified. (1) Double the horizontal distance from midline to the most distant thyroglossal duct in front of the hyoid bone was 2.4 to 9.6 mm. (2) The length of the single duct above the hyoid bone which spreads into many ductuli as it approaches the foramen cecum was about 3 to 5 mm in 2- to 6-year old children. (3) The diameter of the thyroglossal duct at the level of the cranial top of the hyoid bone was 175 to 1,400 microns. Half of the examined cases were less than 500 microns, which may have rendered direct dissection impossible. Based on these studies, we propose: (1) that a minimum of 10 mm of the hyoid bone should be resected, and for the sake of safety, more than 15 mm is preferable; and (2) that the depth of the core-out should be less than 5 mm in young children to avoid the breakdown of the branched ductuli near the foramen cecum.

Cecum

Bacteria isolated from the duodenum, ileum, and cecum of young chicks.

Facultatively anaerobic and strictly anaerobic bacteria colonizing the intestinal tracts of 14-day-old chicks fed a corn-based diet were enumerated, isolated, and identified. Colony counts from anaerobic roll tubes (rumen fluid medium) or aerobic plates (brain heart infusion agar) recovered from homogenates of the duodenum, upper and lower ileum, and cecum varied appreciably among samples from individual birds. Anaerobic and aerobic counts from the duodenum and ileum were similar. Anaerobic counts were highest from the cecum (0.7 X 10(11) to 1.6 X 10(11)/g of dry tissue) and exceeded aerobic plate counts by a factor of at least 10(2). Facultatively anaerobic groups (Streptococcus, Staphylococcus, Lactobacillus, and Escherichia coli) comprised the predominant flora of the duodenum and ileum, although large numbers of anaerobes (9 to 39% of the small intestine isolates), represented by species of Eubacterium, Propionibacterium, Clostridium, Gemmiger, and Fusobacterium, were also recovered. Strict anaerobes (anaerobic gram-positive cocci, Eubacterium, Clostridium Gemmiger, Fusobacterium, and Bacteriodes) made up nearly the entire microbial population of the cecum. Scanning electron microscopy of the intestinal epithelia of chicks revealed populations of microbes on the duodenal, ileal, and cecal mucosal surfaces.

Anaerobiosis

Comparison of bacterial populations of the pig cecum and colon based upon enumeration with specific energy sources.

Concentrations of bacteria in the ceca and colons of pigs were measured by determinations of colony counts on rumen fluid-based media in anaerobic roll tubes. With our most complete medium (medium CCA), the mean colony count of cecal samples from 20 pigs was 2.37 X 10(10) +/- 1.0 X 10(10) (+/- standard deviation)/g (wet weight). The mean number of bacteria attached to or associated with cecal epithelial tissues from three pigs on medium CCA was 2.67 X 10(7) +/- 0.81 X 10(7)/cm2 of tissue. The proportions of gut bacterial populations able to use various energy substrates were estimated on the basis of relative colony counts. The following substrates are listed in descending order of their capacity to support growth of cecal bacteria: glucose, starch, cellobiose, xylose, Trypticase, gastric mucin from swine, mannitol, glycerol, and lactate. The effect of diet upon this distribution was not examined. The relative proportions of bacteria from a given population that were able to grow on various selective media were used as population profiles. Comparisons of populations in this way indicated that differences could be detected between (i) populations from the cecum of littermate pigs, (ii) populations from the cecum and colon of the same pig, and (iii) populations in the lumen of the cecum as compared with populations associated with cecal mucosa.

Animals

Grain overload in cattle and sheep: changes in microbial populations in the cecum and rumen.

Samples from the rumen and cecum of cattle and sheep were cultured to determine changes in microbial populations resulting from overfeeding with grain. Before the animals were overfed, the predominant organisms from both sides were those that grew anaerobically on a relatively nonselective ruminal fluid medium and would not grow on selective mediums designed to culture lactobacilli, streptococci, coliforms, or Clostridium perfringens. By 24 hours after overfeeding, lactic acid bacteria had increased in numbers so that they were the most numerous organisms in both the rumen and the cecum. The concentrations of coliforms and C perfringens also increased after overfeeding and were generally higher in the cecum than in the rumen.

Animal Feed

Anatomy of the cecum of the vole, microtus agrestis.

The anatomy of the cecum of the vole, Microtus agrestis, was investigated using macroscopic dissections, "wet" and dried total specimens, and correlated light, scanning and electron microscopy. The cecum of the vole reveals a series of structural differentiations including a mural lip in the ampulla ceci and a spiral fold in the corpus ceci. The mucosa covering the cecal wall possesses short, wide-opened crypts and differs from the classical descriptions of the large intestinal mucosa. Fine structural observations suggest the cecal epithelium to be capable of active absorption. The morphological findings are correlated with the herbivorous habit of the vole and compared with observations in the rabbit and other rodents.

Animals

Nucleic acid and protein content of rat cecum mucosa in dietary adaptation-growth by cellular hyperplasia.

The deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and protein content of the isolated cecum mucosa was determined in control rats and rats with adaptive cecum growth induced by dietary polyethylene glycol. Feeding the polymer resulted in an increase in the total amount of mucosal nucleic acids and protein which was statistically significant after 2-4 days and reached twice the control value after 2 months. During growth, the protein/DNA, protein/RNA and RNA/DNA ratios remained unaltered, indicating hyperplasia and not hypertrophy of the epithelial cells. The water content of the mucosa increased from 75 to 81% during adaptation, possibly related to the stimulation in active sodium transport reported earlier. Recalculation of parallel Na-K-ATPase data on the basis of DNA demonstrated a doubling of Na-K-ATPase activity per mg DNA in the fully adapted cell.

Adaptation, Physiological

Effects of diets containing dried whey on the lactase activity of the small intestinal mucosa and the contents of the small intestine and cecum of the pig.

Two studies were conducted to establish the effects of dietary lactose supplied from dried whey on the lactase activity in the contents of the small intestine and cecum as well as the mucosa of the small intestine. In the first study, feeding 0, 10, 25, or 40% dried whey for 120 days did not alter the mucosal lactase specific activity (mumoles galactose released/mg protein) in the duodenum, upper jejunum, or lower ileum. In the second study, total lactase activity in the small intestine was estimated from the total activity found in 10-cm segments of each meter of small intestine. Feeding a diet containing 40% whey continuously from weaning at 5 weeks of age or from 12 weeks of age did not alter the total lactase activity of pigs killed at 21 weeks of age. Dietary lactose tended to increase the lactase activity in the contents of the cecum and small intestine, but the increases were not always statistically significant. In the second study, Chester White pigs had approximately threefold greater mucosal lactase activities than that of Hampshires. These two breeds may be suitable models for detailed studies into the relationships between lactase deficiency and lactose intolerance.

Animals

Characteristics of Bacteroides isolates from the cecum of conventional mice.

Bacteroides isolates from the cecum of conventional mice were characterized and grouped according to their ability to ferment or hydrolyze carbohydrates and other compounds believed to be present in the intestinal ecosystem. The isolates were divided into 11 groups on the basis of the fermentation of glucose, cellobiose, gum arabic and xylan (hemicelluloses), N-acetylglucosamine, and dextrin; the hydrolysis of starch and casein (proteolysis); and the production of indole. Stock cultures of B. fragilis, B. distasonis, B. ovatus, B. vulgatus, and B. ruminicola were characterized in the same way. The strains isolated most frequently from the mouse cecum resembled B. fragilis (except that arabinose was fermented) and B. thetaiotaomicron.

Animals

Experimental botulism in chickens: the cecum as the site of production and absorption of botulinum toxin.

Highly purified preparations of Clostridium botulinum toxins were administered to chickens by various routes. Chickens were highly susceptible to type A toxin, but relatively resistant to toxins of other types. Type C toxin (12S) at a dose of 1 X 10(7) mouse ip LD50 failed to kill the chicken by the oral route. Oral administration of 10 or more of type A, C, or D spores killed normal chickens, whereas cecoligated chickens were insusceptible to oral administration of 10(6) spores. These results show that the site of production and absorption of botulinum toxin in chickens is the cecum. Peroral administration of spores of a type C strain cured of its prophages and producing the C2 factor only also killed normal chickens. Chickens appeared to the more susceptible to the C2 factor than to the C1 toxin. The C2 factor, therefore, may play more important role in chicken deaths from toxico-infection with type C organisms. The optimum temperature for growth of C. botulinum types C and D was found to be 40-42 C. Type C and D toxins were significantly more stable than type A toxin in the cecum contents with pH above 7. These characteristics and the high density of distribution of type C spores in the environment may explain prevailing cases of type C botulism among broiler chickens.

Animals

HgCl2 inhibition of Na-independent L-proline transport in chicken proximal cecum.

The proximal cecum of 5- and 13-wk-old chickens takes up L-proline (Pro) by two saturable pathways that differ in their requirement of Na+. The kinetic properties of Pro influx in cecal segments incubated in Na(+)-free conditions, have been studied and the effect of HgCl2 on the uptake process has been tested. Experiments were carried out using an in vitro everted-sleeve method. Kinetic parameters were estimated by nonlinear regression analysis. One min Pro fluxes in tissues incubated in presence of HgCl2 fit a straight line, indicating that a Na-independent saturable component was inhibited. Estimated Kd* values are the same in 5- and 13-wk-old chickens, 0.023 +/- 0.001 and 0.027 +/- 0.001 microliters.mg-1 x min-1, respectively. HgCl2-sensitive fluxes fit a Michaelis hyperbola, with similar Km* values, 4.85 +/- 1.86 (5-wk) and 9.47 +/- 3.0 (13-wk) mmol/l. However, Vmax* in 5-wk chickens (0.662 +/- 0.053 nmol.mg-1 x min-1) is higher than in 13-wk birds (0.420 +/- 0.039), in accordance with previous results. The present data give further support to the existence of a Na-independent L-proline carrier in the chicken proximal cecum which is inhibitable by HgCl2.

Age Factors

Biochemical and cytochemical studies of digestive-absorptive functions of esophagus, cecum, and tequment in Schistosoma mansioni: acid phosphatase and tracer studies.

Acid phosphatase activity was examined, both cytochemically and biochemically, using beta-glycerophosphate (betaGP) and p-nitrophenyl phosphate (NPP) as substrates. The hydrolysis of these substrates differs in pH optimum and sensitivity to some inhibitors. A latent component of the enzyme activity could be demonstrated with betaGP but not with NPP as substrate. These differences suggest the presence of multiple enzymes operative at acid pH in S. mansoni. Cytochemical localization of the sites of hydrolysis of these substrates shows the major activity of the digestive system to be in the posterior portion of the esophagus and in the cecum. The reaction product in the posterior esophagus is found in small dumbbell-shaped vesicles and in the basal infoldings, while in the cecum it occurs on the apical plasmalemma, basal infoldings, and in pleiomorphic vesicles. The electron-dense tracers, ferritin, peroxidase, Thorotrast, and latex beads were all ingested but none was phagocytized. Tracer material was found in some "apparent" vesicles with subsequently were shown by the lanthanum staining technique to be in communication with the extracellular space.

4-Nitrophenylphosphatase