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PubMed1975

Stochastic model of contractions at a point in the duodenum.

Contractions at one point in the human duodenum were studied as a time series. Manometric records were made over long time periods from the duodenum in fed human subjects. A 5-s grid was superimposed on the time axis of the records. Each 5-s interval was treated as a slow-wave cycle within which either a contraction or a no-contraction could occur. The resulting series of alternating runs of contractions and no-contractions was tested for the existence of trends. Trends were found indicating possible temporal dependence. A Markov-type model was used to try to generate data similar to the real data. Success was achieved by a model that assumed a probability of contraction dependent on the three previous slow-wave cycles. The frequency distributions obtained from the real and generated data were compared using Chi-square goodness-of-fit tests and found to be statistically similar. The correlations in time found for the contractions might be due to a time dependency in the controls for contraction over four successive slow-wave periods, 20 s in humans.

Animals↗
PubMed1975

Mechanisms of disposal of acid and alkali in rabbit duodenum.

Stripped duodenal mucosa of rabbits was mounted in Ussing chambers containing a Ringer solution gassed with 100% O2. The disappearance of acid or alkali from the mucosal solution of short-circuited tissue was measured with a pH stat while the serosal pH was kept at 7.4. The duodenum rapidly disposed of both acid and alkali; neither property was altered by gassing with N2 while iodoacetate was in the perfusing solutions. Prevention of release of CO2 from the mucosal chamber obliterated the early rapid phase of acid disposal by the mucosa while a similar maneuver in the serosal chamber increased the appearance of serosal acid without altering the rate of acid disposal. Gut sacs of rabbit duodenum in vitro and in vivo showed a positive correlation between acid disposal and the rate of luminal CO2 production. While acid disposal progressively decreased with time for the in vitro gut sacs, the in vivo gut sac showed no fatigue in this respect. Luminal acidification in the Ussing chamber was associated with a profound reduction in short-circuit current (Isc), partially reversible by elevation of the mucosal pH but not by luminal glucose. Our data suggest that acid disposal occurs in part by intraluminal neutralization and in part by diffusion into the mucosa.

Acid-Base Equilibrium↗
PubMed1992

Characteristics of spontaneous and evoked motility in the isolated perfused porcine duodenum.

The aims of the study were to evaluate characteristics of spontaneous motility and of the ascending excitatory peristaltic reflex (AEPR) and intraluminal cross-sectional area in the isolated perfused porcine duodenum. The parameters were measured by an intraluminal catheter by use of the perfused side-hole technique and impedance planimetry. Respiratory parameters such as pH and oxygen consumption and the arterial perfusion pressure were monitored and did not vary significantly throughout the study time. Spontaneous motility was intense at the beginning but declined and disappeared within 45-90 min. It was abolished by atropine, epinephrine, and UK-14,304 (an alpha 2-adrenoceptor agonist). Secondary motility was evoked by intraluminal balloon distensions by raising the balloon pressure to 1.5 kPa for 1-min periods. Reproducible results regarding the AEPR, external balloon diameters to elicit the AEPR, and intraluminal cross-sectional area were obtained. The order of potency (pD2 values) for inhibition of the AEPR was the selective M3-receptor antagonist 4-DAMP greater than atropine greater than the selective M2-receptor antagonist AFDX-116 greater than the selective M1-receptor antagonist pirenzepine greater than hexamethonium. 4-DAMP was 16 and 29 times more potent than AFDX-116 (P less than 0.02) and pirenzepine (P less than 0.02). None of the drugs altered the intraluminal cross-sectional area during the balloon distensions. The model provides the opportunity for physiological and pharmacological studies of duodenal motility and duodenal cross-sectional area devoid of extrinsic neural and endocrine effects. The abolishment of the AEPR by atropine is caused by blockade of the M3-receptor in the porcine duodenum.

Animals↗
PubMedDate not supplied

Stimulatory effect of nitric oxide on bicarbonate secretion in bullfrog duodenums in vitro.

The effect of nitric oxide (NO) on HCO-3 secretion was examined in vitro using an isolated preparation of bullfrog duodenum. The tissue was bathed in unbuffered Ringer's solution gassed with 100% O2 on the mucosal side and HCO-3 Ringer's solution gassed with 95% O2-5% CO2 on the serosal side. The HCO-3 secretion was measured by the pH-stat method using 2 mmol/l HCl as the titrant to keep the mucosal pH at 7.4. (+/-)-(E)-Ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamine (NOR3) was used as a NO donor and added to the serosal solution. To analyze the NOR3 action on HCO-3 secretion, the effects of dibutyryl adenosine-3',5'-cyclic monophosphate (dbcAMP), dibutyryl guanosine-3',5'-cyclic monophosphate (dbcGMP), methylene blue, and indomethacin on the HCO-3 response were also examined. NOR3 (1x10(-4) and 3x10(-4) mol/l) caused an increase in HCO-3 secretion in a dose-dependent manner, and this effect appeared with an about 30-min time lag, reaching the level of 1.5-2.5 times greater than basal values at 1-2 h later. Both dbcAMP (1x10(-3) mol/l) and dbcGMP (1x10(-3) mol/l) also caused a significant increase in HCO-3 secretion in bullfrog duodenums in vitro, although the onset of the HCO-3 response to dbcGMP was delayed as compared to the former. The stimulatory action of NOR3 on duodenal HCO-3 secretion was significantly attenuated by methylene blue (5x10(-5) mol/l) and indomethacin (1x10(-5) mol/l), the latter also inhibiting the HCO-3 response to dbcGMP. The release of prostaglandin E2 in the serosal solution was significantly increased after addition of NOR3 (3x10(-4) mol/l) and dbcGMP (1x10(-3) mol/l) in an indomethacin-sensitive manner. These results suggest that the NO donor increases duodenal HCO-3 secretion in vitro, and this action of NO donor is cGMP-dependent and mediated by endogenous prostaglandins. Duodenal HCO-3 secretion may be regulated locally by NO/cGMP in addition to prostaglandin/cAMP.

Animals↗
PubMed2004

Outcome of duodenum-preserving resection of the head of the pancreas for intraductal papillary-mucinous neoplasm.

BACKGROUND: The standard surgical procedure for intraductal papillary-mucinous neoplasm of the pancreatic head is pylorus-preserving pancreatoduodenectomy. A less extensive resection may be justified because most intraductal papillary-mucinous neoplasms are benign or of low-grade malignancy. AIMS AND METHODS: The outcome of duodenum-preserving pancreatic head resection with preservation of the main bile duct was evaluated retrospectively in 13 patients with a branch-type intraductal papillary-mucinous neoplasm in the head of the pancreas and with a median (range) follow-up of 60.0 (0.3-99.5) months. RESULTS: Post-operative complications included anastomotic leakage (n=3), bile duct perforation (n=1), intra-abdominal bleeding (n=3), delayed gastric emptying (n=2) and death (n=2). All the resection margins were clear of tumour on histological examination. Ten of 11 patients maintained over 90% of their pre-operative body weight. Glucose tolerance improved in 4 of 11 evaluable patients, was unchanged in 6 and worsened in 1 patient. Biliary scintigraphy showed that bile flow was delayed compared with that before surgery (8.8 +/- 1.1 vs. 19.6 +/- 4.6 min; p = 0.03). Neither recurrence nor metastasis was observed. CONCLUSION: The results of duodenum-preserving pancreatic head resection for branch duct-type intraductal papillary-mucinous neoplasm were satisfactory and provided a good quality of life.

Adenocarcinoma, Mucinous↗
PubMed1987

Argyrophil cells in the rat duodenum after gastrectomy.

Two different techniques of reconstruction after total gastrectomy were performed in rats: Roux-en-Y (RY) and jejunal interposition (JI). Sham-operated rats were used as controls. Sixteen weeks after surgery the animals were sacrificed. The distribution of the enteroendocrine cells in the duodenal and proximal jejunal mucosa was examined using the Grimelius silver nitrate stain. The frequency of the Grimelius-positive cells was estimated as number of cells per square millimeter of gut surface and as number of cells per transverse section of intestine. Intestinal villi height was also measured in the same duodenojejunal tracts. After gastrectomy, the JI rats showed a better weight gain than RY rats (p less than 0.05). A significant difference in the distribution of intestinal argyrophil cells was seen. The bypassed duodenojejunal tracts in RY rats showed a marked reduction of the Grimelius-positive cells in comparison with JI rats and controls (p less than 0.01). A reduction in the number of argyrophil cells in the proximal duodenum was also noticed in the JI rats in comparison with controls (p less than 0.01). A decrease in the villi height resulted in all the gastrectomized rats (p less than 0.01), but a significant decrease was also noticed in RY rats in comparison with JI (p less than 0.01). Our experimental observations suggested that the exclusion of the duodenum from intestinal transit after gastrectomy caused atrophy of the gut mucosa and a marked reduction in the number of argyrophil enteroendocrine cells in the bypassed tracts.

Anastomosis, Roux-en-Y↗
PubMed1991

Elastic properties of the isolated perfused porcine duodenum.

The aim was to investigate elastic wall properties of the isolated perfused porcine duodenum using manometry and impedance planimetry. Distension of an intraluminal balloon with definite pressure steps of 0.5, 1.0, 2.0, 3.0 and 5.0 kPa was done with simultaneous recording of balloon pressure and balloon cross-sectional area (Bcsa). Wall thickness of the relaxed intestine was estimated from measurement of tissue density. The elastic wall parameters were calculated from these measurements. Balloon inflation elicited a phase of rapid Bcsa increase followed by an accommodation phase of slow Bcsa increase. At steady state, the circumferential and the radial wall stress increased as linear functions of the applied balloon pressure, while the circumferential and the radial wall strain increased nonlinearly. The incremental elastic moduli increased exponentially. Our model allows the study of passive biomechanical wall properties of the intact duodenum. The duodenal wall showed qualitatively and also quantitatively an elastic nature.

Animals↗
PubMed1997

Effect of tea decoction given to rats ad libitum for a relatively long time on body weight gains and iron, copper, zinc, magnesium concentrations in blood, liver, duodenum and spleen.

The aim of our study was to examine the influence of tea decoction given ad libitum for 15 days on body weight gains and on nonheme iron, copper, zinc and magnesium concentrations in the blood from a semisynthetic diet provided to healthy rats. We have also evaluated the reserves of these essential minerals in the liver, duodenum and spleen. Our findings indicate that the tea decoction significantly reduced the total body weight growth in the tea group as compared to the control group (p < 0.0001). The total body weight gains for the control and tea groups were 13.2 and 2.4%, respectively. On the other hand, our data show that the tea decoction significantly reduced nonheme iron concentration in the total blood by 31.8% (p < 0.001). Similarly, the reserve of iron stored in the liver and the duodenum declined more significantly by 57% (p < 1.10(-7) and 50.5% (p < 1.10(-6)). respectively. In contrast to the inhibitory effect on iron concentration and its stored reserve, tea decoction significantly increased zinc, copper and magnesium concentrations in the total blood. Zinc, copper and magnesium concentrations increased by 29.4 (p < 0.05), 69.0 (p < 0.001) and 48.7% (p < 0.001), respectively. Moreover, tea decoction treatment did not raise the reserve of zinc or copper significantly but it increased the reserve of magnesium stored in the liver (p < 0.05).

Animals↗
PubMed1975

The motor-stimulating effect of natural motilin on the lower esophageal sphincter fundus, antrum and duodenum in dogs.

Natural motilin was investigated for its effect on gastrointestinal motor activity in anesthetized dogs. In doses starting from 10 ng/kg as single injection and 100 ng/kg-h as intravenous infusion, motilin induced phasic pressure changes in the lower esophageal sphincter (LES) and in the lumen of the fundus, antrum, and duodenum. Tachyphylaxis was seen in 6 out of 10 dogs. Motilin had no effect on isolated muscle strip preparations of the LES, fundus, antrum, and duodenum in this species.

Animals↗
PubMed1982

Effect of fixation on the light microscopical visualization of mast cells in the mucosa and connective tissue of the human duodenum.

Mast cells have been studied in the mucosa and connective tissue of 28 biopsies of human duodenum. They were collected from individuals who for various reasons had to undergo upper intestinal endoscopy. Tissues were fixed in both standard formalin and a formalin-acetic acid (FA) fixative developed for visualization of mucosal mast cells. With both fixatives connective tissue mast cells (CTMC) were equally well recognized. Only with the FA fixative, an additional population of mast cells was observed both in the mucosa and the connective tissue. The population consisted of round cells, always smaller than CTMC, with a number of granules staining violet with toluidine blue. These mast cells comprised two cell types, differing in size, the larger being present in both the mucosa and the connective tissue, the smaller ones in a subepithelial position in the crypts of Lieberkühn and in the adjacent submucosa. It was suggested that this first mentioned additional population was similar to the mucosal mast cells (MMC) observed in rats and mice. The subepithelially located metachromatic cells differed in morphology from the globule leukocytes found in rats and mice. It was concluded that in the human duodenum a population of cells with MMC staining characteristics is present, which can only be visualized under special fixation conditions. Their further characterization and role in various disease conditions remains to be elucidated.

Acetates↗
PubMed1987

Antigenic stimulation with proteins of cow's milk via the oral route in guinea pigs and rats. 1. Measurement of antigenically intact beta-lactoglobulin and casein in the gastrointestinal contents of duodenum, jejunum and ileum.

Guinea pigs and rats drinking cow's milk ad libitum have had the contents of their stomach, duodenum, jejunum and ileum examined for antigenically native, undigested beta-lactoglobulin and casein. The whey protein was present, in every case, in higher concentration and could be found, although in decreasing amounts, right down to the ileum. In the rat, casein could not be shown at any level of the small intestine and in the guinea pig only at the level of the duodenum.

Administration, Oral↗
PubMed1968

Response of the canine duodenum to intraluminal challenge with cholera exotoxin.

In response to intraluminal challenge with crude cholera exotoxin, canine Thiry-Vella duodenal loops consistently produced isotonic fluid for a 24-36 hr period. Isotonic fluid production generally began within 15 min after challenge. Mean bicarbonate concentration of fluid produced by duodenal loops was 24+/-6 (SD) mEq/liter. Perfusion of exotoxin-treated duodenal loops with an isotonic electrolyte solution containing glucose 60 mOsm/liter caused a significant decrease in exotoxin-induced isotonic fluid output. The net effects of glucose on isotonic fluid absorption by perfused duodenal loops were not significantly different before and after administration of crude cholera exotoxin. The response of canine duodenal loops to challenge by cholera exotoxin differs from responses of jejunal and ileal loops in a) absence of a detectable "lag period" between administration of exotoxin and initiation of net fluid output; b) a longer period of fluid production following exotoxin administration; and c) a significantly greater net fluid output per unit length of gut. The mean bicarbonate concentration of the fluid produced by duodenum is less than that produced by ileum, but is not significantly different from that produced by jejunum. The duodenal response is similar to that of the more distal small bowel segments in that an effect on isotonic fluid movement is observed shortly after exotoxin administration and the maximum rate of exotoxin-induced isotonic fluid production is not reached until 4-5 hr after exotoxin administration. The basis for the consistent delay of 4-5 hr between intraluminal exotoxin administration and maximum gut fluid production has not yet been determined. Current data are consistent with the hypothesis that the rate of secretion of isotonic fluid induced by cholera exotoxin is not significantly different per unit length, in duodenum and ileum and that the lesser net fluid output in the ileum is due to the greater capacity for isotonic fluid absorption by the more distal small bowel segment.

Animals↗
PubMed2000

Developmental mucin gene expression in the gastroduodenal tract and accessory digestive glands. II. Duodenum and liver, gallbladder, and pancreas.

Studies were undertaken to provide information regarding cell-specific expression of mucin genes and their relation to developmental and neoplastic patterns of epithelial cytodifferentiation. In situ hybridization was used to study mRNA expression of mucin genes in duodenum and accessory digestive glands (liver, gallbladder, pancreas) of 13 human embryos and fetuses (6. 5-27 weeks' gestation), comparing these with normal and neoplastic adult tissues. These investigations demonstrated that the pattern of mucin gene expression in fetal duodenum reiterated the patterns we observed during gastric and intestinal ontogenesis, with MUC2 and MUC3 expression in the surface epithelium and MUC6 expression associated with the development of Brünner's glands. In embryonic liver, MUC3 was already expressed at 6.5 weeks of gestation in hepatoblasts. As in adults, MUC1, MUC2, MUC3, MUC5AC, MUC5B, and MUC6 were expressed in fetal gallbladder, whereas MUC4 was not. In contrast, MUC4 was strongly expressed in gallbladder adenocarcinomas. MUC5B and MUC6 were expressed in fetal pancreas, from 12 weeks and 26 weeks of gestation, respectively. Surprisingly, MUC3 which is strongly expressed in adult pancreas, was not detected in developmental pancreas. Taken together, these data show complex spatio-temporal regulation of the mucin genes and suggest a possible regulatory role for mucin gene products in gastroduodenal epithelial cell differentiation.

Adenocarcinoma↗
PubMed1986

Vascular compression of the duodenum.

Compression of the third or fourth part of the duodenum by the superior mesenteric artery or one of its branches is the anatomic basis for some cases of duodenal obstruction. Two cases of vascular obstruction of the duodenum after surgical correction of scoliosis are presented. The embryologic and pathoanatomic bases for this condition, and the rationale for treatment, are described.

Adolescent↗
PubMed1985

1,25-Dihydroxyvitamin D3-induced calcium-binding protein: localization in organ-cultured embryonic chick duodenum.

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) induces de novo biosynthesis of a specific calcium-binding protein (CaBP) in embryonic chick duodenum in organ culture. Using a highly sensitive and specific, peroxidase-antiperoxidase immunocytochemical procedure, 1,25(OH)2D3-induced CaBP in the organ-cultured duodenum was found only in the cytoplasm of absorptive cells, corresponding to its localization in rachitic chick duodenal cells after a single injection of 1,25(OH)2D3 in vivo. This observation, along with evidence correlating CaBP with calcium transport, strongly supports the use of the embryonic chick duodenal organ culture system as a physiologically relevant model of the vitamin D-dependent calcium absorptive mechanism.

Absorption↗
PubMed1986

In situ detection of vitamin D-induced calcium-binding protein (9-kDa CaBP) messenger RNA in rat duodenum.

We have previously described the molecular cloning of a cDNA fragment synthesized from rat duodenal mRNA coding for a 9000-dalton vitamin D-induced calcium-binding protein (9-kDa CaBP) (3). We now report the use of this cloned cDNA to study the cytological distribution of 9-kDa CaBP mRNA in rat duodenum by in situ hybridization. Tissue sections, fixed in ethanol:acetic acid, were hybridized to the 3H-cDNA probe and processed for autoradiography. The specificity of the CaBP mRNA-DNA hybrid formation was checked using 3H-labeled plasmid pBR322 DNA as a control probe. 9k-Da CaBP mRNA, visualized by silver grains, was found only in the absorptive epithelial cells, and the concentration was greater in the cells at the villous tips than in those of the crypts. The 9k-Da CaBP mRNA was observed mainly in the cytoplasm of the columnar cells and less frequently in the nucleus. Labeling was not seen in the brush border and goblet cells. The submucosa, with Brunner's glands and muscularis, also showed no specific 9-kDa CaBP mRNA concentration. This demonstration of 9-kDa CaBP gene activity in the columnar cells of the rat duodenum illustrates the usefulness of in situ hybridization for characterization of specific cells involved in the expression of 1,25(OH)2 D3 activity.

Animals↗
PubMed2003

Dieulafoy's lesion of duodenum: a case report.

BACKGROUND: Dieulafoy's lesion is an uncommon but important cause of recurrent upper gastrointestinal bleeding. Extragastric location of Dieulafoy's lesion is rare. We report two cases of Dieulafoy's lesion of the duodenum and discuss the management of this extremely uncommon entity. CASE PRESENTATION: Two cases of massive upper gastro-intestinal bleeding in young adults due to Dieulafoy's lesion of the duodenum are reported. Endoscopic diagnosis was possible in both cases. Hemostasis was achieved successfully by endoscopic adrenaline injection. The endoscopic appearance, pitfalls in the diagnosis and management of this rare lesion are discussed. CONCLUSIONS: Endoscopic diagnosis of extragastric Dieulafoy's lesion can be difficult because of the small size and obscure location of the lesion. Increased awareness and careful and early endoscopic evaluation following the bleeding episode are the key to accurate diagnosis. Adrenaline injection is one of the important endoscopic modalities for control of bleeding.

Adult↗
PubMed1981

Transition from neurogenic to myogenic receptivity for thyrotropin-releasing hormone (TRH) in the duodenum of the neonatal rat.

A tetrodotoxin- and hexamethonium-sensitive response to thyrotropin-releasing hormone (TRH), an in vitro contraction, first appeared in the duodenum of the 3 day old rat, was increased by day 16, decreased there-after and was extinguished after weaning. A tetrodotoxin-resistant response to TRH, a relaxation, appeared at day 13 and became distinct after weaning. The development of neurogenic receptivity for TRH precedes the appearance of myogenic receptivity in the rat duodenum.

Acetylcholine↗