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At least 163 records · Page 9Linked to original sources
PubMed1991

Epidemiology of adenocarcinomas of the small intestine: is bile a small bowel carcinogen?

Using pathology reports and other data from the Cancer Surveillance Program, the population-based cancer registry of Los Angeles County, we evaluated demographic characteristics and the detailed subsite distribution of adenocarcinomas of the small intestine for the period 1972-1985. The most striking finding was the great preponderance of these tumours in the duodenum, especially in comparison with other histologic types of small bowel cancers. Fifty percent of all small intestinal adenocarcinomas occurred at this location, even though the duodenum comprises just 4% of the entire length of the small bowel. Furthermore, after excluding those cases occurring in the duodenum but with indeterminate subsite, 57% of these duodenal primaries could be mapped to the 2nd portion of the duodenum, a six to seven centimeter segment containing the Ampulla of Vater. We could pinpoint the location for 48 of the 77 tumours (62%) occurring in this segment, specifically to areas adjacent to the Ampulla. We also confirmed the high male to female ratio of small bowel adenocarcinomas in blacks and non-Latino whites, but could find no evidence of such an effect in Latinos or Asians; however, the number of cases was not large in these latter two racial-ethnic groups.

Adenocarcinoma↗
PubMed1989

[Experimental study of injury on the small intestine in acute portal vein occlusion and the following restoration of portal vein flow in rats--free radicals in the small intestine and lipid peroxidation].

Free radicals in the small intestine were quantified by using an electron spin resonance spectrometer, and the amounts of TBA (thiobarbituric acid) reactants in arterial plasma, portal venous plasma and intestinal tissue were determined at the several stages. The effects of allopurinol, alpha-tocopherol, the simultaneous occlusion of superior mesenteric artery or the porto-jugular venous bypass, with the temporary occlusion of the portal vein, were also investigated. 1) Free radical concentration (mostly, semiquinones of CoQ and/or flavin in mitochondria) decreased with portal vein occlusion but showed a temporary increase at 10 sec after reperfusion. Allopurinol suppressed such temporary increase. 2) TBA reactants increased with the temporary occlusion of the portal vein. TBA reactants decreased during the portal vein occlusion with alpha-tocopherol and during reperfusion with allopurinol. Lipid peroxidation in the small intestine was also diminished by using the methods of simultaneous occlusion of the superior mesenteric artery or the porto-jugular venous bypass. In conclusion, there may be three sources for the generation of superoxide: the xanthine oxidase system, semiquinone radicals and paramagnetic metal irons. They may induce lipid a peroxidation, which accelerates the injury on the small intestine, in acute portal vein occlusion and the following restoration of portal vein flow in rats.

Allopurinol↗
PubMed1976

Vitamin K2 absorption by rat everted small intestinal sacs.

Small intestinal absorption of vitamin K2 was investigated in vitro. Experiments with increasing concentrations of the vitamin up to 900 nM revealed linerity between the concentration and the rate of absorption (r = 0.99). Addition of metabolic uncouplers and inhibitors such as 2,4-dinitrophenol, sodium azide, and potassium cyanide did not decrease the rate of absorption of the vitamin (P less than 0.05). Absorption rate of the vitamin increased when taurocholate was replaced by a nonionic detergent, Pluronic F-68. The addition of butyric and octanoic acids to the incubation solution caused an increase in the absorption rate of vitamin K2. No change in the absorption of the vitamin occurred in the presence of oleic and linoleic acid. Addition to vitamins K1 and K3 to the incubation solution did not change the rate of vitamin K2 absorption. These findings suggest that vitamin K2 is absorbed by the small bowel by a passive noncarrier-mediated diffusion process. The rate of diffusion varied when the lipid and bile salt composition of the incubation solution was modified. Distal intestinal absorption of vitamin K from bacterial sources coupled with colonic absorption of the vitamin may be the major constant source of vitamin K in mammals.

Animals↗
PubMed2001

Small intestine contrast ultrasonography (SICUS) in the diagnosis of small intestine lesions.

After the ingestion of iso-osmolar polyethylene glycol solution, the small bowel can be visualized on ultrasonography. The aim of this study was to assess sensitivity and specificity of SICUS in diagnosis of small bowel lesions. A total of 53 consecutive patients with suspected intestinal pathology underwent a diagnostic workup, including a small bowel follow-through and SICUS performed by independent operators. The sonologist was unaware of the clinical data. Diagnostic sensitivity and specificity were assessed using radiologic findings. Diagnostic sensitivity of SICUS was 100%, with a specificity of 97%. The concordance index was 0.956 (p < 0.003, kappa statistics) and the conformity between SICUS and radiology was 1. The diagnostic accuracy of SICUS to detect small bowel lesions is comparable to that of small bowel follow-through. Results of this study support the use of noninvasive, widely available, inexpensive, and nondemanding SICUS as an initial investigation in patients with suspected small bowel disease.

Adolescent↗
PubMed1999

Sodium recirculation and isotonic transport in toad small intestine.

Isolated small intestine of toad (Bufo bufo) was mounted on glass tubes for perfusion studies with oxygenated amphibian Ringer's solution containing glucose and acetate. Under open-circuit conditions (Vt = -3.9 +/- 1.8 mV, N = 14) the preparation generated a net influx of 134Cs+. The time course of unidirectional 134Cs+-fluxes was mono-exponential with similar rate constants for influx and outflux when measured in the same preparation. The flux-ratio was time invariant from the beginning of appearance of the tracers to steady state was achieved. Thus, just a single pathway, the paracellular pathway, is available for transepithelial transport of Cs+. From the ratio of unidirectional Cs+-fluxes the paracellular force was calculated to be, 18.2 +/- 1.5 mV (N = 6), which is directed against the small transepithelial potential difference. The paracellular netflux of cesium ions, therefore, is caused by solvent drag. The flux of 134Cs+ entering and trapped by the cells was of a magnitude similar to that passing the paracellular route. Therefore, independent of the convective flux of 134Cs+, every second 134Cs+ ion flowing into the lateral space was pumped into the cells rather than proceeding, via the low resistance pathway, to the serosal bath. It is thus indicated that the paracellular convective flow of 134Cs+ is driven by lateral Na+/K+-pumps. Transepithelial unidirectional 42K+ fluxes did not reach steady state within an observation period of 70 min, indicating that components of the fluxes in both directions pass the large cellular pool of potassium ions. The ratio of unidirectional 24Na+ fluxes was time-variant and declined from an initial value of 3.66 +/- 0.34 to a significantly smaller steady-state value of 2.57 +/- 0.26 (P < 0.001, N = 5 paired observations), indicating that sodium ions pass the epithelium both via the paracellular and the cellular pathway. Quantitatively, the larger ratio of paracellular Na+ fluxes, as compared to that of paracellular Cs+ fluxes, is compatible with convective flow of the two alkali metal ions through the same population of water-filled pores. With a new set of equations, the fraction of the sodium flux passing the basement membrane barrier of the lateral space that is recirculated through the cellular compartment is estimated. This fraction was, on average, 0.72 +/- 0.03 (N = 5). It is concluded that isotonicity of the transportate can be maintained by producing a hypertonic fluid emerging from the lateral space combined with reuptake of salt via the cells.

Animals↗
PubMed1985

[Function tests of the lower small intestine with 75selenium-labeled homotaurocholic acid in Crohn disease and resections of the small intestine].

UNLABELLED: Faecal excretion of bile acids was investigated using 75Se-homotaurocholic acid (75SeHCAT) in a total of 75 patients: 9 with irritable colon, 58 with Crohn's disease and 8 with small-bowel resection due to various indications but without Crohn's disease. Bile acid malabsorption, taken as a pathological bile acid retention of less than 19%, was found present in 43 patients with diseased terminal ileum or with more than 20 cm resection of this organ, except in one case (12 cm). On the other hand a normal bile acid retention (21 to 27%) was found in 29 of 72 patients (including 9 patients with irritable colon) who showed either no radiologically detectable lesion of the ileum (n = 21) or changes involving an extension of up to 30 cm (inflammation or resection) in the terminal ileum (n = 8), with the exception of one case (50 cm). Three patients had a raised bile acid excretion contrary to clinical expectation: they had colitis Crohn without radiologically detectable involvement of the small intestine. Thus using the 75SeHCAT-retention test it seems possible to recognize functional disorders in diseased segments of the bowel before the appearance of radiologically detectable changes. CONCLUSION: 75SeHCAT is a suitable substance for investigations on the function of the lower small intestine.

Adolescent↗
PubMed1988

Results of laparotomy in immunoproliferative small intestinal disease.

Immunoproliferative small intestinal diseases (IPSID), previously known as Mediterranean Lymphomas, constitute more than 60% of the non-Burkitt's small intestinal lymphomas in Tunisia. A multidisciplinary study of IPSID was undertaken by the Tunisian/French Lymphoma Study Group in 1980 to reach a better understanding of the two subgroups of the disease: secreting IPSID (essentially alpha-chain disease [ACD]); and nonsecreting IPSID (NS-IPSID) (extensive small intestinal lymphomas without gammopathy). The results of initial exploratory laparotomy performed in 38 cases of IPSID (17 ACD and 21 NS-IPSID) are described here, and show notable similarities between the two groups: the extensive pattern of the abnormal cell infiltrate along the major part of the small intestine; frequent and extensive involvement of the mesenteric lymph nodes; the existence of several degrees of severity in small intestinal mesenteric lymph nodes; and other intraabdominal organ involvement. Certain differences also were observed: the relatively high degree of tropism of the NS-IPSID towards the gastric mucosa which was absent in the ACD of this series; and the more frequent involvement of the entire length of the small bowel in ACD. In spite of these discrete differences, the IPSID form a homogeneous group which is definitely distinguishable from the segmentary small intestinal lymphomas known as Western-type, and which account for approximately one third of our non-Burkitt's small bowel lymphomas.

Adolescent↗
PubMed1985

[Nitrogen and amino acid resorption in the small intestine of growing swine. 1. Animal study method, nitrogen content and amino acid composition of the small intestine chyme by administration of various proteins].

The amount of endogenous N in the chyme at the end of the small intestine and the amino acid composition of the ileum chyme were ascertained with growing pigs with ileorectostomy after feeding qualitatively differentiated protein sources. In dependence on the protein used, distinct differences turned out for some amino acids with regard to their content in the ileum chyme. Bacteriologic and histologic investigations subsequent to the dissection of the test animals showed that - in comparison to the control animals-the functions of the small intestine remained the same during the time of the experiment. The experiment method described appears to be suitable for absorption investigations up to the end of the small intestine of growing pigs.

Amino Acids↗
PubMed1979

Immunoelectrophoretic studies on human small intestinal brush border proteins. A quantitative study of brush border enzymes from single small intestinal biopsies.

A method for measuring brush border membrane enzymes from small intestinal biopsies by crossed immunoelectrophoresis is presented. The use of a brush border specific antiserum made isolation of the brush border membrane before analysis unnecessary. This prevented loss of material which, together with inactivation of enzymes, was a limiting factor in previous studies of brush border enzymes from peroral biopsies. In 58 biopsies from patients without gastrointestinal disorders a close correlation between antigenic activity and corresponding enzymatic activity was shown for the following enzymes: sucrase-isomaltase (EC 3.2.1.48-EC 3.2.1.10), lactase-phlorizin hydrolase (EC 3.2.1.23-EC 3.2.1.62), microvillus aminopeptidase (microsomal, EC 3.4.11.2) and dipeptidyl peptidase IV (EC 3.4.14.X). The immunoelectrophoretic patterns of intestinal mucosa near the ligament of Treitz, and in jejunum and ileum were established. The method presented is thought to be of value in further studies of the molecular basis of brush border diseases.

Aminopeptidases↗