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PubMed1993

Directional porosity of porcine small-intestinal submucosa.

Small-intestinal submucosa (SIS) has been shown to be a promising biomaterial for vascular graft applications. This study examines the directionality property of SIS porosity using 35 SIS specimens from 13 pigs. In addition, the effects of the weight of the donor pig, pre-conditioning of 13 additional SIS specimens, and the duration of the test of five additional SIS specimens on such porosity are reported. The porosity from serosal to mucosal direction was found to be four times greater than the porosity in the opposite direction. The weight of the donor pig was not found to be an important factor in SIS porosity. Preconditioning served to increase the average serosal porosity index at 120 mm Hg static water pressure from 2.99 to 8.33 mL/(min cm2). The porosity in the mucosal direction was not affected by preconditioning. Porosity in both directions decreased with increasing test duration. The directionality property of SIS porosity may be an important factor in its success as a vascular graft. The term 'porosity' is used throughout this article, but current standards also refer to the term 'permeability' to describe the passage of liquid through a vascular graft.

Animals↗

PubMed1984

Uptake of uric acid, xanthine and hypoxanthine by brush-border membrane vesicles from mouse small intestine.

Using mouse small intestine brush-border membrane vesicles virtually free of xanthine oxidase (EC 1.2.3.2) and free of uricase (EC 1.7.3.3) the uptake of the purines uric acid, xanthine and hypoxanthine have been studied. The sodium-dependent overshoot phenomenon shown to exist for the uptake into the vesicles for D-glucose and L-phenylalanine was not observed with the purines. However, the uptake of the three purines in the presence of NaCl or KCl was greater than the uptake in the presence of either NaSCN or mannitol. Although 12.9% of the xanthine uptake and 17.6% of the hypoxanthine uptake was attributed to binding to the membranes, almost all the uric acid uptake was due to transport into an osmotically active space. The apparent intravesicular volume, calculated after 60 min incubation, for the three purines was consistently greater than the values obtained with D-glucose, L-glucose and L-phenylalanine equilibration, suggesting slow continuing penetration of purines associated with swelling or an apparent accumulation of purines within the vesicles associated with normal vesicle volume.

Animals↗

PubMed1989

Swelling of the Golgi apparatus and decrease of galactosyltransferase in polyamine-deficient bovine lymphocytes and epithelium of mouse small intestine.

When bovine small lymphocytes stimulated by concanavalin A were treated with inhibitors (alpha-difluoromethylornithine (5 mM) and ethylglyoxal bis(guanylhydrazone) (100 microM)] of polyamine biosynthesis, swelling of the Golgi apparatus was observed. This was accompanied by decreases in the amount of the Golgi apparatus and of the specific activity of galactosyltransferase. Both spermidine and spermine, at physiological concentrations, stimulated galactosyltransferase activity 2-3-fold. When mice were treated with these inhibitors, the following changes were observed in the epithelial cells of small intestine: swelling of the Golgi apparatus; decrease in the amount of the Golgi apparatus; and decrease of galactosyltransferase activity.

Animals↗

PubMed2006

Cytogenetic and clinicopathological characterization by fluorescence in situ hybridization on paraffin-embedded tissue sections of twenty-six cases with malignant lymphoma of small intestine.

OBJECTIVE: In small intestinal malignant lymphoma (SIML), the correlation between specific chromosomal abnormalities and clinicopathological features remains unclear. The aim of this study was to determine the frequency of chromosomal translocations involving the BCL1, BCL2, c-MYC, BCL6 and MALT1 genes by using fluorescence in situ hybridization directly on paraffin-embedded tissue sections (tissue-FISH). MATERIAL AND METHODS: Twenty-six cases diagnosed as having SIML between 1996 and 2003 were the subjects of the clinicopathological investigation conducted in this study. Tissue-FISH was performed with specific probes on paraffin-embedded tissue sections as described previously. RESULTS: The primary site was frequently located at the duodenum (9 cases, 35%). In accordance with the World Health Organization classification, 14 (53%) cases were diagnosed as having diffuse large B-cell lymphoma (DLBCL) and 6 (23%) as marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). Macroscopically, DLBCL and MALT lymphoma displayed various macroscopic features. Cytogenetically, IGH-BCL2 translocation was detected in 3 (21%) out of 14 DLBCL cases, but in none of the MALT lymphomas. BCL6 translocation was detected in 5 (35%) of 14 DLBCL cases and in 1 (17%) of 6 MALT lymphoma cases (17%). API2-MALT1 translocation was detected in 1 (7%) of 14 DLBCL cases and in 1 (17%) of 6 MALT lymphoma cases. CONCLUSIONS: The duodenum was preferentially involved in SIML. DLBCL and MALT lymphoma showed various macroscopic features. Tissue-FISH analysis disclosed that DLBCL is cytogenetically heterogeneous. Furthermore, our study validated tissue-FISH as an additional promising diagnostic tool for detecting specific chromosomal translocations in NHL.

Adolescent↗

PubMed1998

Posthatch development of mucosal function in the broiler small intestine.

Changes in small intestinal morphology, in the indices of cellular development, and in the activities of some mucosal enzymes were examined in broilers from hatch through 14 d. In addition the effects of holding birds without access to feed for 36 h and of deutectomy were examined. Development of the intestine was rapid from 2 d after hatch although rates of development were different in duodenum, jejunum, and ileum. Villus volume in the duodenum reached a plateau after 7 d although it continued to increase in the jejunum and ileum. Enterocyte density changed little with age. Indices of tissue activity, ribosomal capacity, and cell size decreased with age but at differing rates at the three intestinal sites. Sucrase-maltase activity was low in the duodenum and highest in jejunum and ileum and increased in the jejunum to a maximum 2 d after hatch, then decreased. Delayed access to feed after hatch depressed mucosal development for several days, with the duodenum generally reaching control values earlier than the jejunum. Morphological changes following delayed access to feed included some clumping of microvilli on Day 1 after hatching and abnormal crypt structure between Days 7 and 9. Deutectomy resulted in initial decreased intestinal growth, but this was compensated for by 6 to 8 d in the duodenum, after which development was parallel to that of normal chicks. It appears that nutrient supply from yolk is less crucial for mucosal development then withholding feed for 36 h, which delays normal intestinal development.

Aging↗

PubMed1971

Adrenoceptors in the human foetal small intestine.

Human foetal small intestine was shown to contain both alpha- and beta-adrenoceptors with a predominance of beta-adrenoceptors. The tissue examined was obtained from foetuses of gestational age between 8 and 26 weeks.

Acetylcholine↗

PubMed1999

Repair of a full thickness corneoscleral defect in a German shepherd dog using porcine small intestinal submucosa.

Porcine small intestinal submucosa (SIS) was used, in conjunction with a conjunctival graft, to repair a full thickness corneoscleral defect resulting from the excision of a limbal melanoma in a German shepherd dog. The SIS was found to provide adequate mechanical support and to act as a suitable physical barrier in place of the excised cornea and sclera. Corneal vascularisation was present distant to the graft by two weeks postoperatively but this was effectively controlled with topical cyclosporin. By six weeks postoperatively, the graft had become incorporated into the cornea and sclera, and the associated corneal neovascularisation had resolved. From this initial case, porcine SIS would appear to be a suitable material for the repair of corneoscleral defects in dogs.

Animals↗

PubMed1993

Thiamine outflow from the enterocyte: a study using basolateral membrane vesicles from rat small intestine.

1. Rat small intestinal basolateral membrane vesicles (BLMVs) were prepared and found to be 31% non-vesiculated and 69% vesiculated, 4.9% right side out and 63.8% inside out. 2. Thiamine uptake by BLMVs followed a hyperbolic time course reaching equilibrium after 60-90 min incubation. Uptake was not affected by the transmembrane potential or by the presence or absence of Na+ or K+ in the incubation medium. 3. At concentrations below 1.25 microM, [3H]thiamine was taken up mainly by a saturable mechanism with an apparent Michaelis-Menten constant (Km) = 1.32 microM and maximal flux (Jmax) = 1.93 pmol (mg protein)-1 (4 s)-1. At higher concentrations, a non-saturable mechanism prevailed. 4. Only 29% of [3H]thiamine taken up by the vesicles was membrane bound, the remaining being translocated into the vesicular space. No thiamine phosphoesters could be detected inside the vesicles. 5. In the absence of ATP, the Na(+)-K(+)-ATPase inhibitors ouabain, frusemide and vanadate reduced thiamine uptake by 35, 30 and 15% respectively. 6. In experiments conducted with K+ inside the vesicles and Na+, Mg2+ and ATP outside, the time course of thiamine uptake by BLMVs displayed an overshoot (80-90% increment) at 30 s incubation as compared to controls. When ATP was replaced with phosphocreatine, or when NaCl was replaced with isosmotic amounts of KCl, the overshoot disappeared. 7. The thiamine analogues pyrithiamine, amprolium and 4'-oxythiamine decreased the ATPase-dependent transport of [3H]thiamine by 100, 86 and 31% respectively. 8. These results provide evidence that the transport of thiamine by BLMVs is coupled directly to the hydrolysis of ATP (primary active transport).

Adenosine Triphosphate↗

PubMedDate not supplied

[The x-ray microanalysis of the mucosa of the rat small intestine].

A rat small intestine mucosa is shown to accumulate significant amount of potassium and chloride. There was found a correlation between the content of these chemical elements and glycoprotein compartmentalization in goblet cell secret, brush border of enterocytes and a mucus layer. In this connection a role of mucus glycoproteins in membrane digestion is discussed. For preparation of samples the cryotechniques of electron microscopy are used.

Animals↗

PubMed1985

Scanning electron microscopical observation on the isolated mucosa of rat small intestine: with special reference to the intestinal crypt.

The small intestinal mucosa of rats (male, aged 8 weeks) was isolated by the Bjerknes and Cheng's method (1981): the anesthetized rats were perfused through the left ventricle with a solution of ethylenediaminetetraacetic acid (30 mmol/l) in calcium-magnesium-free Hanks' solution, and then the mucous epithelium was removed from a segment of the duodenum, jejunum and ileum by means of vibration. Three-dimensional images of crypts on the isolated mucosa were obtained by scanning electron microscopy. The length and number of the crypts between the villi were observed to decrease along the intestine from the duodenum to the ileum. The majority of intestinal crypts were simple non-branched tubular glands, however, budding and bifurcation of the crypt ends were often observed. It was relatively rare to find longitudinally split crypts. The shapes of the crypts seems to denote various stages of the proliferation of crypts.

Animals↗

PubMed1978

Fucosidosis and I-cell disease: a fine structural and silver-staining study of abnormal inclusion bodies in small-intestinal cells.

Small-intestinal cells of children with fucosidosis or the I-cell type of lysosomal storage disease were investigated with special attention to the fine structure and silver-staining patterns of abnormal inclusion bodies. The results indicate an accumulation of mucopolysaccharide and or glycoprotein, and lipid materials in the greater part of these inclusion bodies. The significantly enlarged lysosome-like bodies in the absorptive cells of these patients showed the same silver-stain affinity as the Golgi apparatus, apical vesicles and tubules, and the cell coat. This might indicate a crinophagic function of the lysosome-like bodies in the transport or secretion of cell coat material. Additional information is given on the storage of material in the significantly enlarged inclusion bodies in cultured fibroblasts and in the abnormal vacuoles of peripheral blood lymphocytes in I-cell disease.

Adolescent↗

PubMed1997

Mucosal morphogenesis and cytodifferentiation in fetal porcine small intestine.

BACKGROUND: Development of the small intestine is essential for proper nutrition of the fetus and the neonate. This investigation examines the morphogenesis and cytodifferentiation of developing fetal porcine small intestinal mucosa. METHODS: Fetuses were collected from gilts after hysterectomy. Small intestinal segments were removed and processed for light and electron microscopy. RESULTS: Fetal porcine small intestine developed from a simple tube of stratified epithelium to a tube containing villus and intervillus regions of simple columnar epithelium. This development occurred in a proximal to distal direction. By Day 40 of gestation, cytodifferentiation was evident with the presence of goblet cells and enteroendocrine cells in the duodenum. As development progressed, microvilli lengthened and components of the apical endocytic complex (AEC) were observed. By Day 110 of gestation, tubular and vesicular components of the AEC were confined to the jejunum, whereas large lysosomal vacuoles were observed in the distal jejunum. Duodenal epithelium at Day 110 was similar to postnatal epithelium. CONCLUSIONS: The pattern of fetal porcine small intestinal development is similar to that reported for fetal human small intestine. Villus development and cytodifferentiation occur at similar relative times in gestation when compared to the human. These observations support the use of the fetal pig as a model for investigations of human small intestinal development.

Animals↗

PubMed1996

Rare causes of occult small intestinal bleeding, including aortoenteric fistulas, small bowel tumors, and small bowel ulcers.

The most common cause for gastrointestinal bleeding of small bowel origin is angiodysplasia, followed by tumors of the small intestine, and various other causes, including small bowel ulcers and aortienteric fistulas. With the advent of improved diagnostic tests, including push and sonde enteroscopy, timely endoscopic diagnosis of these rare small bowel lesions has become possible, enabling the clinician to make better therapeutic decisions. This article focuses on the rare small bowel sources of intermittent and chronic gastrointestinal blood loss.

Endoscopy, Gastrointestinal↗

PubMed1975

Measures to minimize small intestine injury in the irradiated pelvis.

Small intestine injury causes long-term suffering and high mortality. Five of 187of our patients had developed serious small intestine injury. Four patients had corrective surgery. Three patients died. All were women. Subsequently, all patients who received definitive pelvic irradiation had small intestine roentgenograms to determine itslocation and mobility. Female patients, thin patients, and elderly patients had larger amounts of small intestine in the whole pelvis, a deeper cul de sac, and a greater incidence of relatively immobile small intestine. Patients with relativelyimmobile small intestine in the treatment field may be predisposed to injury. There wasno relationship of the incidence of relatively immobile small intestine to prior pelvicsurgery. We used the findings from the small intestine roentgenograms to modify indiviually the radiotherapy regimen so as to minimize the risk for small intestine injury. Patients were placed in the prone position to displace the small intestineout of the treatment fields used for booster dose irradiation. The treatment field wasmodified to exclude the small intestine. The total tumor dose delivered was determinedby expectations for curve vs. complications. To date, none of the patients in this study group has developed small intestine injury. Cadaver studies showed the feasibility of elective shortening of the pelvic cul de sac. The small intestine can be displacedaway from the bladder, prostate, or cervix.

Age Factors↗

PubMed1995

The impact of surgical technique on the development of graft versus host disease in a rat small intestinal transplant model.

The small intestine and its mesentery contain a large amount of lymphoid tissue that can mediate graft-versus-host disease (GVHD) in small intestinal transplant recipients. To assess the impact of surgical technique and the retention of the recipient's small intestine on GVHD intensity, 12 adult Lewis rats received heterotopic small bowel transplants and 12 received orthotopic small bowel transplants from Brown Norway donors. Twelve Lewis to Lewis heterotopic small-bowel-transplanted animals served as the control group. All recipients were given cyclosporine (10 mg/kg/alternate days) subcutaneously. The parameters followed were: weight gain and feed intake; clinical signs of GVHD; relative spleen weight; popliteal lymph node enlargement assay; and histological evaluation of spleen, liver, skin, native intestine, and transplanted intestine. According to the clinical scoring system, heterotopically transplanted animals were found to have a more severe GVHD than the orthotopic group. There were statistically significant differences between the relative spleen weights of the heterotopic transplant group and the control group (P = 0.001, 0.004, and 0.007 on days 7, 14, and 21, respectively) and between the heterotopic and orthotopic groups at 7 days (P = 0.037). Lymph node enlargement assays were statistically different between heterotopic and orthotopic groups (P = 0.019, 0.020, and 0.007 on days 7, 14, and 21, respectively). Histological evaluation of skin biopsy specimens also demonstrated that GVHD was indeed more severe in the heterotopic transplanted group when compared with orthotopically transplanted animals. These findings confirm that retention of the native small intestine in the heterotopic intestinal transplant model significantly increases the severity of GVHD following transplantation.

Animals↗

PubMed1988

The effect of splanchnic nerve stimulation and neuropeptide Y on cholera secretion and release of vasoactive intestinal polypeptide in the feline small intestine.

The effect of sympathetic nerve stimulation and intra-arterial infusion of neuropeptide Y (NPY) on net fluid secretion and release of vasoactive intestinal polypeptide (VIP) was studied in the cat small intestine during a secretion due to cholera toxin. Activation of the splanchnic nerves (4 Hz, 5 ms, 5 V) decreased net fluid secretion to 57 +/- 10% of control. Concomitantly, the release of VIP was reduced to less than 50%. Furthermore, close i.a. infusion of NPY (estimated increase in plasma concentration 75 nmol l-1) reduced the net fluid secretion and VIP release to 27 +/- 5 and 28 +/- 4% of the pre-stimulatory value. The correlation between the decrease in net fluid secretion and reduction in VIP release showed a strong positive correlation (r = 0.83). These results strongly indicate that the antisecretory effect of sympathetic nerve stimulation during cholera diarrhoea is mediated by inhibition of secretory VIP neurons in the intestinal mucosa. A similar mechanism is also proposed for the intravascularly administered NPY.

Animals↗

PubMed1998

[Prognostic differences in primary malignancies of the small intestine].

Malignant small bowel tumours are rare, with about 320 deaths every year due to metastases. Tumours of differing histologic entitites (adenocarcinomas, leimyosarcomas, non-Hodgkin, lymphomas, carcinoids) are detected at late stages of the disease because of non-specific symptoms. Valuable diagnostic means are small bowel enema, intestinoscopy and abdominal CT/ultrasound. Five-year survival rates are poor for carcinomas (21%), for sarcomas (37%), lymphomas (44%) and best for carcinoids (100%). Surgical options are poor for carcinomas with a high number of R2 resections and bypass operations. Multivisceral surgery is beneficial for sarcomas and lymphomas, followed by local radiation therapy or chemotherapy.

Adolescent↗

PubMed1997

Comparative assessment of D-xylose absorption between small intestine and large intestine.

The present study aimed to evaluate the absorption of D-xylose, a passively absorbed five-carbon monosaccharide, from the large intestine compared with the small intestine, in order to explore the absorption potential of the large intestine. D-Xylose absorption was evaluated in the intestinal loop and everted sacs in rats and comparisons were made between small intestine (mid-gut) and large intestine (colon). The absorption of D-xylose was smaller, by an order of magnitude or more, after administration into the loop of large intestine than after administration into that of small intestine, based on appearance in plasma and disappearance from the intestinal loop. D-Xylose absorption was practically insignificant (nominal 4.9%) in 60 min in the large intestine, whereas it was moderate (57.0%) in the small intestine. Consistently, the uptake of D-xylose in everted sacs was about 20 times larger in the small intestine than in the large intestine. Thus the passive membrane permeability of D-xylose was demonstrated to be negligible in the large intestine, even though the small intestine was fairly permeable. This result helps rationalize kinetic modelling strategies assuming the small intestine as the sole absorption site for gastrointestinal absorption in-vivo. It also suggests that hydrophilic drugs with molecular size similar to or larger than D-xylose may not be good candidates for colonic drug delivery by controlled release.

Animals↗