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PubMed1996

Physicochemical characteristics of emulsions during fat digestion in human stomach and duodenum.

Seven fasting subjects were fitted with nasogastric and nasoduodenal tubes and received intragastrically a coarsely emulsified test meal. Gastric and duodenal aspirates were collected after 1, 2, 3, and 4 h. In the duodenum, most lipids (> 90%) were present as emulsified droplets 1-100 microns in size. Large droplets and unemulsified material present in the test meal (> 100 micron) disappeared, whereas smaller droplets (1-50 microns) were generated after 1 h of digestion. Thus the median lipid droplet diameter significantly decreased (19.6 vs. 56.5 microns in the test meal) and the droplet surface area significantly increased (1.58 vs. 0.70 micron2/g fat). Intermediate droplet diameters were 34.3, 46.3, and 27.6 microns after 2, 3, and 4 h, respectively. In the stomach, a comparable emulsion particle size pattern was observed, with median droplet diameters of 17.2, 37.9, 52.4, and 41.6 microns after 1, 2, 3, and 4 h, respectively. However, the extent of triglyceride hydrolysis was much lower in the stomach (6-16%) than in the duodenum (42-45%), where small droplets were enriched in lipolytic products, cholesterol, and phospholipids. The present findings show for the first time that most dietary lipids are present in the human duodenum as emulsified droplets 1-50 microns in size and that no further marked emulsification of dietary fat occurs in the duodenum compared with the stomach.

Adult↗
PubMed1993

Multielectrode mapping of slow-wave activity in the isolated rabbit duodenum.

The technique of multiple simultaneous recordings from a large number of extracellular electrodes (> 100) is currently used in the study of normal and abnormal electrical conduction in the heart and the genesis of cardiac arrhythmias. To investigate whether such a system could also be applied in gastrointestinal electrophysiology, several studies were performed with this technique on segments of isolated rabbit duodenum. A multiple-electrode assembly consisting of 240 silver wires was positioned on the serosal surface of the duodenum, and the recorded signals were, after suitable processing, stored. Thereafter, analysis of all simultaneously recorded slow waves during a selected period of time was performed to reconstruct the pattern of conduction in the duodenum. The first results show that there is a considerable variation in conduction pattern, which is determined by the site of the natural pacemaker. Several experiments were performed to rule out possible deleterious effects of positioning the multiple-electrode assembly on the duodenum. Furthermore, prolonged periods of recording did not influence propagation speed and pattern provided that the positioning of the multiple electrode assembly was performed with care. Entrainment of the natural pacemaker was possible by applying electrical stimuli through 2 of the 240 extracellular electrodes during simultaneous recordings. In conclusion, multisite extracellular mapping of gastrointestinal smooth muscle is possible and can be used to study origin and spread of slow-wave activity.

Animals↗
PubMed1987

Role of the proximal duodenum in gastrin regulation following antrectomy.

Antrectomy is accepted as the most effective surgical treatment of recurrent duodenal ulcer after complete vagotomy. Although antrectomy is aimed at reducing serum gastrin levels, both human and experimental reports seem to indicate that gastrin concentrations may be unchanged following this operation. The probable source of gastrin has been considered to be the proximal third of the duodenum, since at this level increased tissue gastrin concentrations were found after antrectomy. The present study was carried out in order to gain insight into the mechanism by which the duodenum may compensate for the removal of the antrum. Forty white rats were randomly divided into two equal groups and underwent antrectomy with gastroduodenostomy or simple laparotomy. Three to four months after surgery, serum gastrin determinations were carried out by radioimmunoassay both in fasted and freely fed rats. The duodenum was then removed and its proximal third was used for G cell counts (immunoperoxidase method) and for assessment of G cell cytoplasmic granule distribution (electron-microscopic examination). Antrectomy significantly increased fasting serum gastrin levels (p less than 0.01), while it completely abolished the gastrin response to food ingestion (p less than 0.001). In antrectomized rats, the duodenal G cell number was significantly higher than in control rats (p less than 0.001), whilst the G cell cytoplasmic granule number remained unchanged. In conclusion, the present study indicates that in the rat the proximal duodenum increases its content of tissue gastrin following antrectomy mainly by enhancing the regional G cell density.

Animals↗
PubMed1981

Vitamin D3 metabolite injections to thyroparathyroidectomized pregnant rats: effects on calcium-binding proteins of maternal duodenum and of fetoplacental unit.

Fetomaternal relationships with respect to vitamin D metabolism were investigated in thyroparathyroidectomized (TPTX) pregnant rats, with or without treatment with different vitamin D3 metabolites. Calcium-binding protein (CaBP) in maternal duodenum was used as an index of 1,25-(OH)2D3 status of the mother. Pregnant rats were TPTX on day 12.5 and CaBP was measured on 21.5 days of gestation by RIA in maternal duodenal mucosa and in the fetoplacental unit (placenta, fetal membranes, and fetal intestine). In the duodenum of TPTX mothers, the CaBP concentration was reduced by 50%. This fall was associated with a decrease of 1,25-(OH)2D in maternal plasma. CaBP in maternal duodenum increased by the administration of 1,25-(OH)2D3 or 1,24,25-(OH)3D3. In contrast, 24,25-(OH)2D3 injections to TPTX mothers were ineffective. In both placenta and fetal membranes, CaBPs decreased by 20% in TPTX mothers and were normalized only in 1.25-(OH)2D3-treated TPTX mothers. In the fetal intestine, CaBP variations paralleled those of maternal duodenal CaBP. The data indicate that plasma levels of 1,25-(OH)2D in TPTX pregnant rats are partly under the control of maternal parathyroid glands, and they support that even in pregnancy, the CaBP concentration in maternal duodenum may well reflect the 1,25-(OH)2D status of the mother. The CaBP synthesis in placenta and fetal membranes are vitamin D-dependent, and their regulation differs from that of intestinal CaBP. It app]ears that 1 alpha-hydroxylase activities of the fetoplacental unit (placenta and fetal kidney) are blunted in TPTX animals and that CaBP synthesis in the fetus depends on the presence of 1 alpha-hydroxylated vitamin D3 metabolites in the mother.

24,25-Dihydroxyvitamin D 3↗
PubMed1989

Pathogenesis of the earliest epithelial cell damage induced by mepirizole and cysteamine in the rat duodenum.

Mepirizole (200 mg/kg) and cysteamine (100 mg/kg) induced epithelial cell damage in the proximal duodenum of rats within 30 min after s.c. administration. The injury induced was severe 60 min later. Gastric acid secretion determined in intact animals was stimulated by these agents 30 and 60 min later when the intraluminal pH of the duodenum was significantly decreased. Duodenal blood flow was significantly decreased beginning 5 min after administration up to 60 min. Oral treatment with sodium bicarbonate (300 mg/kg), cimetidine (100 mg/kg), omeprazole or NC-1300 (gastric proton pump inhibitors, 30 mg/kg) and 16,16-dimethyl prostaglandin E2 (10 micrograms/kg) protected the epithelium from damage induced by the two duodenal ulcerogens. Epithelial cell damage in the duodenum in response to mepirizole and cysteamine appears to be related to the increased gastric acid secretion followed by lowered intraduodenal pH of the duodenum having decreased blood flow.

Animals↗
PubMed1988

[Pyloroplasty and motile functions of the stomach and duodenum].

Mongrel dogs were prepared by attaching 2 and 1 silver needle bipolar electrodes on the gastric antrum and bulbus of the duodenum, respectively. Among the obtained active potential from these dogs at chronic stage, investigations were performed mainly on the discharge frequency of spikes, propagation pattern of electrical excitation, and relationship of the stomach and duodenum. In addition, barium was loaded as the stomach contents and extraction dynamics of the loads were observed radiologically. The following was these investigations concerning about the pyloroplasty and motile functions of the stomach and duodenum. Experimental methods 1) Electromyography and extraction dynamics of stomach contents were observed in no treated control dogs. 2) Heineke-Mikulicz type pyloroplasty, Finney type pyloroplasty, or pylorectomy was performed on the above described control dogs. Electromyographical comparison was made among the types of pyloroplasty. 3) Dogs subjected to selective vagolysis (SV), selective proximal vagotomy (SPV), or gastric transection (Tr) were divided into groups with and without pyloroplasty. Electromyography and extraction dynamics of stomach contents were observed in these groups of animals. Results 1) In the control dogs, the mean discharge frequency of spikes in the gastric antrum at fasting time was 4.86 cycle/minute. The spikes propagated to the pyloric side periodically. The discharge frequency of spikes was reduced by the load of stomach contents which took about 120 minutes to be extracted. 2) When the types of pyloroplasty were compared, smaller electromyographical changes were obtained in dogs subjected to Heineke-Mikulicz type pyloroplasty. 3) Pyloroplasty did not affect the discharge frequency of spikes at fasting time, whereas, high incidences of antiperistaltic propagation pattern of electrdcal excitation were observed in dogs subjected to SPV. 4) When stomach contents were loaded, drainage effects of pyloroplasty were suggested from the discharge frequency of spikes, propagation pattern of electrical excitation, and findings in extraction dynamics of the stomach contents. In the dogs subjected to SPV, pylorplasty induced no significant fluctuations in the discharge frequency of spikes. Dogs subjected to Tr showed no improvement in the frequent antiperistaltic propagation pattern of electrical excitement after the pyloroplasty. 5) By pyloroplasty, the frequency of simultaneous generation of spikes in the gastric antrum and duodenum was decreased in the SV and Tr groups, while it was increased in the SPV group.

Action Potentials↗
PubMed2001

Comparison of the bacterial flora of the duodenum in healthy cats and cats with signs of gastrointestinal tract disease.

OBJECTIVE: To determine whether a colony environment predisposes healthy cats to high bacterial counts, including counts of obligate anaerobes, in the duodenum and whether increased numbers of bacteria could be found in the duodenum of cats with signs of chronic gastrointestinal tract disease. DESIGN: Prospective study. ANIMALS: 20 healthy control cats (10 from a colony environment and 10 pet cats) and 19 cats with a history of chronic gastrointestinal tract disease. PROCEDURE: Undiluted duodenal fluid was quantitatively and qualitatively assessed by bacteriologic culture under aerobic and anaerobic conditions. Serum concentrations of cobalamin and folate were also measured. RESULTS: Significant differences were not detected in the numbers of bacteria found in the duodenum of cats housed in a colony environment, compared with pet cats fed an identical diet prior to sampling. All healthy cats were, therefore, combined into 1 control group. Compared with healthy cats, cats with clinical signs of gastrointestinal tract disease had significantly lower counts of microaerophilic bacteria, whereas total, anaerobic, and aerobic bacterial counts were not significantly different. None of the cats with disease had total bacterial counts higher than expected from the range established in the control cats. Differences were not detected in regard to serum folate or cobalamin concentrations between diseased and healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE: These findings indicated that healthy colony cats and pet cats have high numbers of bacteria in the duodenum, including high numbers of obligate anaerobes. Our findings also suggest that bacterial overgrowth in the small intestine is not a common clinical syndrome in cats with chronic nonobstructive gastrointestinal tract disease.

Animals↗
PubMed1977

Effects of cholecystokinin on the motility of the distal duodenum and the proximal jujunum in man.

Electrical spike potentials and intraluminal pressure variations were recorded in the distal part of the duodenum and proximal part of the jejunum in 5 normal human subjects before and after a bolus injection of cholecystokinin. A considerable increase in activity was observed in the jejunum after the hormone, whereas there was no response in the distal duodenum. Absence of reaction in the proximal duodenum and an increase in the motility in the distal ileum has previously been demonstrated after cholecystokinin administration. It is concluded that the human duodenum differs from the rest of the small intestine in its reaction to cholecystokinin. The change in reaction appears to occur on a level with the ligament of Treitz.

Cholecystokinin↗
PubMed1977

Malrotation of the duodenum. Frequency in a radiographic control group.

In a prospective radiographic study, abnormal configurations with kinking and torsion (malrotation) of the duodenum were found in 41% of 150 non-dyspeptic subjects. Malrotation of the duodenum (MD) was more frequent before the age of 30, and in the entire series the frequency decreased significantly with age from approximately 60% at 20 years to approximately 25% in individual aged 35 years or more. It should be considered whether the same radiographic configuration as in MD up to the age of 30--35 years is merely due to uncompleted disposition and fixation of the duodenum, so that the diagnosis of MD cannot be definitely established until after that age. In the presence of MD, the luminal diameter of the duodenum was larger than normal, and there was a greater tendency to gastric retention at 4 hours after the barium meal.

Adolescent↗
PubMed1980

[Relation between dopamine and serotonin motor effects on isolated rat duodenum. Possible participation of an excitatory dopaminergic receptor].

The experimental facts presented here allow us to establish a relationship between DA motor effects on isolated rat duodenum, studied in a previous work, (excito-motor between 10(-9) M and 10(-5) M and inhibitor beyond 10(-5) M) and the functional aptitude of this duodenum to answer to 5-HT : 5-HT excito-motor effects are amplified by DA at concentrations less than or equal to 2.6 X 10(-6) M and on the contrary antagonized by DA at concentrations above 5 X 10(-6) M. On the other hand, DA excito-motor effects do not appear on 5-HT-desensitized duodenums. The study of 5-HT dose-response curves in the presence of different concentrations of DA suggests that the amplification of serotonergic effects observed with small DA concentrations can be possibly related to the additional effects of 5-HT on its own receptors and of DA on another receptor. The receptor involved in DA excito-motor action seems to be closely related to the 5-HT receptor since its effects are blocked by the same molecules (methylsergide, cyproheptadine) and since DA excito-motor action is no more evident on 5-HT-desensitized duodenums, but several arguments support the specificity of this receptor for DA (though it is not blocked by haloperidol). Some of its effects are in line with those of DA receptors made conspicuous in other territories and not blocked by haloperidol : central and human colon receptors. On the contrary, DA used at high concentrations (greater than or equal to 5 X 10(-6) M) seems to be able to occupy serotonergic sites, preventing 5-HT access to its receptors until its concentration is high enough to displace DA. From a functional point of view, this antagonistic effect of DA at high concentrations against 5-HT excito-motor effects could facilitate alpha- and beta-mediated inhibitory effects.

Acetylcholine↗
PubMed2001

Accuracy and precision of computer models to predict passage of crude protein and amino acids to the duodenum of lactating cows.

To evaluate the ability of several models to accurately and precisely predict the passage of crude protein (CP) and amino acids to the duodenum of lactating cows, we simulated data from six published studies using the 1989 National Research Council equations, the Mepron Dairy Ration Evaluator (version 1.1), the University of Pennsylvania release of the Net Carbohydrate and Protein System (version 2.12p), the Cornell Net Carbohydrate and Protein System (version 3), and CPM Dairy (version 1.0). Models overestimated the passage of CP from microbes by an average of 323 g/d, and underestimated the passage of CP from feed by an average of 874 g/d. These two errors were partially canceled when CP from microbes and feed were summed to estimate passage of total CP to the duodenum. Many dietary composition variables appeared to bias the predictions; however, the influence of any one variable was small. The efficiency of modeling was high for most predictions but was variable for predicting passage of specific individual amino acids to the small intestine depending on the model selected. These simulations indicated no obvious advantage for any model over the others tested. The models responded to changes in diets by altering the amount of protein from microbes and feed that reached the duodenum, resulting in improved accuracy of predictions of duodenal CP passage compared with simply assuming a constant value for passage of CP to the duodenum.

Amino Acids↗
PubMed2004

Brunner's gland adenoma of duodenum: a case report and literature review.

AIM: To analyze the clinicopathological features of Brunner's gland adenoma of the duodenum. METHODS: A rare case of Brunner's gland adenoma of the duodenum was described and related literature was reviewed. RESULTS: Brunner's gland adenoma of the duodenum appeared to be nodular hyperplasia of the normal Brunner's gland with an unusual admixture of normal tissues, including ducts, adipose tissue and lymphoid tissue. We suggested that it might be designated as a duodenal hamartoma rather than a true neoplasm. CONCLUSION: The most common location of the lesion is the posterior wall of the duodenum near the junction of its first and second portions. It can result in gastrointestinal hemorrhage and duodenal obstruction. Endoscopic polypectomy is a worthy treatment for benign Brunner's gland adenomas, as malignant changes in these tumors have never been proven.

Adenoma↗
PubMed1998

Distention of the fetal duodenum: abnormal finding?

We investigated whether a fluid-filled duodenum is observed in normal fetuses. In part 1 of the study a view in the region of the duodenum was obtained during routine obstetric ultrasonography from 123 low-risk patients. All examinations demonstrated a collapsed duodenum. No gastrointestinal abnormalities were found in these infants. In part 2 of the study, 1163 fetuses (both high-risk and low-risk) were evaluated with real-time scanning, and duodenal fluid without a "double bubble" was seen in one fetus who had a duodenal web. We conclude that a nondistended fetal duodenum is the norm. If fetal duodenal dilation is visualized, this may allow for earlier detection of duodenal obstructions.

Body Fluids↗
PubMedDate not supplied

What should be the standard operation in chronic pancreatitis: Whipple or duodenum-preserving pancreatic head resection?

Surgical options in the treatment of chronic pancreatitis have undergone both development and controversial discussion in the past decades. Operations such as the classical and pylorus-preserving Whipple resections are more and more being replaced by operations such as the duodenum-preserving pancreatic head resection, which preserves extrapancreatic organs like the stomach, the duodenum and the extrapancreatic bile duct. The latter operation preserves a normal food passage and glucose metabolism after surgical intervention. In addition, the duodenum-preserving pancreatic head resection provides long-term pain relief and reduction in up to 90% of chronic pancreatitis patients, as well as a general improvement in quality of life. This article will summarize and compare the surgical options in the treatment of chronic pancreatitis and will provide arguments why the duodenum-preserving pancreatic head resection should replace the classical and the pylorus-preserving Whipple resections as the standard surgical procedure used to treat chronic pancreatitis-related complications.

Chronic Disease↗
PubMedDate not supplied

[An intramural hematoma of the duodenum].

Intramural hematoma of the duodenum is a rare event which is usually associated with trauma. Because of the rarity of this problem, there has been little conformity of opinions as to diagnosis and treatment of this disease. The authors report on a case of intramural hematoma of the duodenum post-traumatically occurred in a young woman. Etiopathogenesis, diagnosis and treatment of hematoma of the duodenum are thoroughly examined in the present study. Plain abdominal radiography, oral barium study, ultrasound examination, CT and RNM are diagnostic tools in this disease. It appears that most patients with intramural hematoma of the duodenum would respond well to conservative management; surgery should be reserved for those cases that remain obstructed over seven days or have evidence of peritonitis. However surgery is mandatory in cases of uncertain diagnosis. The evacuation of hematoma is considered the most effective and safest surgical treatment.

Abdominal Injuries↗
PubMedDate not supplied

Segmental resection of the third and fourth portions of the duodenum after intestinal derotation for a GIST: a case report.

We describe a case in which segmental resection of the third and fourth portion of the duodenum was performed for a very rare duodenal gastrointestinal tumor (GIST). A 58-year old man presented with melena. Capsule endoscopy revealed a pathological bleeding of the duodenum and oral contrast-CT enema confirmed a lesion of the duodenum inferior knee, measuring 3.5 cm in diameter. Such an image suggested a duodenal leiomyoma. Segmental resection of the third and fourth portion of the duodenum after intestinal derotation (Valdoni-Strong's procedure) was carried out and there were no post-operative complications. Pancreas sparing duodenal resection is at the present time indicated only in selected cases. The duodenal resection associated with bowel and right colon derotation has proved to be a safe and adequate procedure and could be preferred to other procedures.

Digestive System Surgical Procedures↗
PubMed2006

Iron regulatory proteins 1 and 2 in human monocytes, macrophages and duodenum: expression and regulation in hereditary hemochromatosis and iron deficiency.

BACKGROUND AND OBJECTIVES: The functions of the iron regulatory proteins (IRP1 and IRP2), which control cellular iron homeostasis are similar but not identical. As an inappropriate up-regulation of total IRP activity has been found in the duodenum and monocytes of patients with hereditary hemochromatosis (HH), we investigated the respective roles of IRP1 and IRP2 in these settings. DESIGN AND METHODS: Specific antibodies were used in RNA-supershift, immunoblotting and immunohistochemistry assays to evaluate IRP1 and IRP2 separately in monocytes, macrophages and duodenum of control subjects, and patients with HH or iron-deficiency anemia. RESULTS: The activity of both IRP1 and IRP2 and the levels of IRP2 were: (i) higher in monocytes and macrophages of HH patients than in those of control subjects; (ii) increased in the duodenal samples of the patients with HH and iron-deficiency anemia. IRP2 levels increased when monocytes differentiated to macrophages. Under all of the examined conditions, IRP2 was induced to a greater extent. In the duodenum of HH and anemic patients, IRP1 was shifted from the aconitase form (present in controls) to the apoform, whereas the IRP1 in monocytes/macrophages was always in the apoform, in both the patients and controls. The RNA-bound fraction of IRP1 was small in all of the samples. Both IRP were expressed more in the villi than in the crypts of the duodenum, with no differences in localization or expression between the patients and controls. INTERPRETATION AND CONCLUSIONS: These findings of the first extensive investigation of the comparative expression of the two IRP in human tissues and blood cells indicate that IRP2 is the major regulator of intracellular iron homeostasis in humans.

Adult↗
PubMed2006

Gene chip analyses reveal differential genetic responses to iron deficiency in rat duodenum and jejunum.

Previous studies revealed novel genetic changes in the duodenal mucosa of iron-deprived rats during postnatal development. These observations are now extended to compare the genetic response to iron deficiency in the duodenum versus jejunum of 12-wk-old rats. cRNA samples were prepared from the duodenal and jejunal mucosa of three groups each of control and iron-deficient rats and hybridized with RAE 230A and 230B gene chips (Affymetrix). Stringent data reduction strategies were employed. Results showed that several genes were similarly induced in both gut segments, including DMT1, Dcytb, transferrin receptor 1, heme oxygenase 1, metallothionein, the Menkes copper ATPase (ATP7A), tripartitie motif protein 27, and the sodium-dependent vitamin C transporter. However, a subset of genes showed regulation in only one or the other gut segment. In duodenum only, gastrokine 1, trefoil factor 1 and claudin 2 were induced by iron-deficiency. Other genes previously identified were only regulated in the duodenum. Overall, these studies demonstrate similarities and distinct differences in the genetic response to iron deprivation in the duodenum versus jejunum and provide evidence that more distal gut segments also may play a role in increasing iron absorption in iron-deficiency anemia.

Animals↗