Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Intestine, Small”

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 973 records · Page 54Linked to original sources
PubMed1978

Regional and central hemodyanamics during segmental ischemia of the small intestine in the rat.

The influence of segmental small intestinal ischemia on the central circulation and on the regional blood flow to consecutive segments of the small intestine in the rat was investigated with the microscphere method. Ischemia was established by ligating 11 arterial mesenteric end arcades, corresponding to one quarter of the total length of the small intestine. The blood supply to different organs and central circulatory variables were determined before, and 10 min, 30 min, 2 h and 14 days after the establishment of the ischemia. After 10 min of ischemia, there was an increase of the blood flow to the segments distal to the ischemic region but after 30 min, this blood flow was the same as the control flow. The central circulatory variables weere not affected. After 2 h of ischemia, the blood supply to both the ischemic and the non-ischemic part of the small intestine had deteriorated considerably. Thus, the vascular resistance in the ischemic segments and the segments surrounding it was increased. Cardiac output was reduced by about 50%. In the experimental group investigated 14 days after establishment of the ischemia, the mortality rate was about 50%. In the survivors, the intestinal blood supply had returned to normal.

Animals↗
PubMed2004

[Establishment and characteristics of orthotopically transplanted model of human primary malignant small intestinal lymphoma in nude mice].

OBJECTIVE: To establish orthotopically transplanted model of human malignant small intestinal lymphoma in nude mice and analyze their biologic characteristics. METHODS: Small intestinal lymphoma tissues from 5 patients were transplanted into intestinal mucosa of nude mice. Tumorgenecity, invasion and metastasis of the transplanted tumors were observed by morphological analyses (light microscopy, electron microscopy and immunohistochemistry), karyotyping and DNA quantitative assay. RESULTS: Tumor tissues from 3 lymphoma patients were successfully transplanted. According to the World Health Organization classification, the three models were classified into non-Hodgkin's lymphoma (B cell) of human small intestine (HSIL-1), high metastasis of non-Hodgkin's lymphoma (B cell) of human small intestine (HSIL-2) and non-Hodgkin's lymphoma (T cell) of human small intestine (HSIL-3), respectively. Immunohistochemistry showed that CD19, CD20, CD22, CD40, CD45 and CD72 were positive in HSIL-1 and HSIL-2, whereas CD3, CD7 and CD45RO were positive in HSIL-3. The karyotypes of the transplanted tumors were all hypotriploid with modal numbers from 55 to 69 and the DNA index (DI) was 1.46 approximately 1.71. The three models had been passaged for 32, 27 and 21 generations respectively in 433 nude mice. The growth rate, resuscitation rate of the liquid nitrogen preserved tumor cells and spontaneous metastasis rate upon transplantation were all 100%. We observed an invasive growth of the transplanted tumors in small intestine, which resulted in disrupting of the intestinal wall, hematogenous metastasis, lymph node metastasis and seeding metastasis. The features of the transplanted tumors were similar to the original tumors in histopathology, ultrastructure, DNA content and karyotype. CONCLUSION: Three strains of orthotopically transplanted model of human primary malignant small intestinal lymphoma in nude mice were successfully developed. The result of research will provide ideal animal models for further studies on mechanism of tumorigenesis, invasion and metastasis of malignant small intestinal lymphoma and experimental therapy.

Adult↗
PubMed1984

Radioautographic visualization of differences in the pattern of [3H]uridine and [3H]orotic acid incorporation into the RNA of migrating columnar cells in the rat small intestine.

The epithelium of rat small intestine was radioautographed to examine whether RNA is synthesized by the salvage pathway as shown after [3H]uridine injection or by the de novo pathway as shown after [3H]orotic acid injection. The two modes of RNA synthesis were thus investigated during the migration of columnar cells from crypt base to villus top, and the rate of synthesis was assessed by counting silver grains over the nucleolus and nucleoplasm at six levels along the duodenal epithelium--that is, in the base, mid, and top regions of the crypts and in the base, mid, and top regions of the villi. Concomitant biochemical analyses established that, after injection of either [5-3H]uridine or [5-3H]orotic acid: (a) buffered glutaraldehyde fixative was as effective as perchloric acid or trichloracetic acid in insolubilizing the nucleic acids of rat small intestine; (b) a major fraction of the nucleic acid label was in RNA, that is, 91% after [3H]uridine and 72% after [3H]orotic acid, with the rest in DNA; and (c) a substantial fraction of the RNA label was in poly A+ RNA (presumed to be messenger RNA). In radioautographs of duodenum prepared after [3H] uridine injection, the count of silver grains was high over nucleolus and nucleoplasm in crypt base cells and gradually decreased at the upper levels up to the villus base. In the rest of the villus, the grain count over the nucleolus was negligible, while over the nucleoplasm it was low but significant. After [3H]-orotic acid injection, the number of silver grains over the nucleolus was negligible at all levels, whereas over the nucleoplasm the number was low in crypt cells, but high in villus cells with a peak in mid villus. The interpretation is that, except for a small amount of label incorporated into DNA from either precursor by crypt cells, the bulk of the label is incorporated into RNA as follows. In the crypts, cells make almost exclusive use of uridine, that is, of the salvage pathway, for the synthesis of ribosomal RNA in the nucleolus and of messenger and transfer RNA in the nucleoplasm. However, when cells pass from crypt to villus, they mainly utilize orotic acid--i.e., the de novo pathway--for the synthesis of messenger and transfer RNA within the nucleoplasm.

Animals↗
PubMed2001

Myoelectric response of the small intestine to the orad presence of the tapeworm Hymenolepis diminuta.

During its 24-hr migratory cycle in the small intestine, Hymenolepis diminuta is located in the orad part of the small intestine during the early morning hours and then in the caudad part of the small intestine during the late afternoon and early evening. During the later period, tapeworm-induced alterations of interdigestive myoelectric activity, a correlate of smooth muscle contraction or intestinal motility, are most intense in the ileal region. The hypothesis tested was that the tapeworm-induced changes in intestinal motility are local responses of the intestine responding to the close proximity of the lumenally positioned tapeworm and to the nutritional state of the host. The small intestine was monitored before and for 20 days after infection using electrodes implanted on the serosa of the small intestine. Myoelectric recordings were analyzed for the frequency of the normal patterns of interdigestive myoelectric spiking patterns and the altered myoelectric spiking related to tapeworm infection. During the morning hours, when the tapeworms are situated in the orad small intestine, no changes were observed during the normal myoelectric pattern of the digestive phase in any region of the intestine. When examined after the conversion of the digestive to interdigestive phase of motility, only on day 10 postinfection was the interdigestive phase significantly altered. It was concluded that the presence of the tapeworm in the orad small intestine during the satiety stage of the rat causes no changes in the electric events of the small intestine, with the exception of day 10 postinfection. Because tapeworms in the orad small intestine do not induce the tapeworm-altered myoelectric activity observed in the afternoon and evening with caudally positioned tapeworms, tapeworm-altered motility is not simply a response of the small intestine to the local presence of the tapeworm.

Animals↗
PubMedDate not supplied

Diagnosis of small intestinal bacterial overgrowth in clinical praxis: a comparison of the culture of small bowel aspirate, duodenal biopsies and gastric aspirate.

BACKGROUND/AIMS: This study was undertaken to validate the usefulness of the culture of duodenal biopsy specimens and gastric aspirate compared to the culture of small bowel aspirate for diagnosing small intestinal bacterial overgrowth. We also investigated the occurrence of predisposing conditions in these patients. METHODOLOGY: Seventy five consecutive patients, admitted because of symptoms which caused us to suspect small intestinal bacterial overgrowth, were studied. For all patients, specimens for the culture of small bowel aspirate, duodenal biopsies and gastric aspirate were obtained during upper endoscopy. RESULTS: Eighteen patients showed growth of gram negative bacteria, 22 growth of gram positive bacteria and 35 showed no significant growth in cultures of small bowel aspirate. Cultures of duodenal biopsies revealed gram negative bacteria in 11 patients, gram positive bacteria in 9 and no growth in 55. Cultures of gastric aspirate revealed gram negative bacteria in 7 patients, gram positive bacteria in 12 and no growth in 51. Ten of the 18 patients with gram negative overgrowth and 13 of the 22 patients with gram positive overgrowth had a predisposing condition. In contrast, only 4 of the 35 without overgrowth had a predisposing condition. CONCLUSIONS: The culture of duodenal biopsy specimens or gastric aspirate is a less sensitive method than the culture of small bowel aspirate. Most patients with culture-proven small intestinal bacterial overgrowth had at least one predisposing condition.

Adult↗
PubMed2000

[Mono-contrast distension study of the small intestine. Comparison of conventional small bowel follow-through with enteroclysis].

PURPOSE: Development of a new monocontrast examination of the small bowel. MATERIAL AND METHODS: The new examination was applied to 20 patients with suspected bowel obstruction or inflammatory bowel disease. A contrast mixture, containing gelatin, a water-soluble contrast medium (Peritrast) and water (GPW-mixture) was given over an intestinal tube. The viscosity of the new contrast mixture was measured by rotation and flow viscosimetry. The diagnostic value and the degree of small bowel distension were determined independently by 3 examiners. By comparison 20 randomized selected small bowel follow-through examinations (SBFT) and 20 small bowel enemas were examined. Special questionnaires were used to determine subjective compatibility and discomfort. RESULTS: Due to the viscosity of the new contrast medium and the administration over an intestinal tube, a good bowel distension was achieved with the GPW mixture. The bowel distension (p: < 0.01) and the diagnostic value (p: < 0.01) of the new examination in comparison to the SBFT was characterized as being significantly better. In comparison to the small bowel enema, distension was not significantly better (p: 0.31-1.0). The diagnostic value of the small bowel enema was characterized as significantly better by one of the three examiners in comparison to the new monocontrast-distenson examination (p-level < 0.01). CONCLUSION: The monocontrast-distension examination is a potential alternative in patients in whom a small bowel enema with barium sulfate is contraindicated.

Abdomen, Acute↗
PubMedDate not supplied

[Transit-slowing anastomosis by 180 degree axial rotation of the upper intestinal segment after massive resection of the small intestine. Preliminary note on an experimental study in the adult dog].

After massive resection of 85 p. cent of the small intestine in the dog, there occurs diarrhoea and malabsorption. These consequences may be palliated by an oblique end-to-end anastomosis with 180 rotation on the intestinal axis of the jejunal sugment above in relation to the ileal segment below. The authors noted slowing of the transit in the 10 operated dogs. The experimental conditions and the results obtained suggest that the technic may be applicable in man.

Animals↗
PubMed1994

Molecular cloning of a human small intestinal apolipoprotein B mRNA editing protein.

Mammalian small intestinal apolipoprotein B (apo B) mRNA undergoes posttranscriptional cytidine deamination with the production of an in frame stop codon and the translation of apo B48. We have isolated a cDNA from human jejunum which mediates in vitro editing of a synthetic apo B RNA template upon complementation with chicken intestinal S100 extracts. The cDNA specifies a 236 residue protein which is 69% identical to the apo B mRNA editing protein (REPR) cloned from rat small intestine [Teng, B., Burant, C. F. and Davidson, N. O. (1993) Science 260, 1816-1819] and which, by analogy, is referred to as HEPR. HEPR does not contain the carboxyl-terminus leucine zipper motif identified in REPR but contains consensus phosphorylation sites as well as the conserved histidine and both cysteine residues identified as a Zn2+ binding motif in other cytidine deaminases. The distribution of HEPR mRNA was predominantly confined to the adult small intestine with lower levels detectable by reverse-transcription polymerase chain reaction amplification in the stomach, colon and testis. These differences in the structure and distribution of the human as compared to the rat apo B mRNA editing protein suggest an important evolutionary adaptation in the mechanisms restricting apo B48 production to the small intestine.

APOBEC-1 Deaminase↗
PubMed1989

Short-term regulation of glycolysis by vasoactive intestinal peptide in epithelial cells isolated from rat small intestine.

In epithelial cells isolated from rat small intestine, we have studied the influence of vasoactive intestinal peptide (VIP), a neurotransmitter which markedly increases enterocyte cyclic AMP, and of two cyclic AMP analogues (8-bromo cyclic AMP and N6,2'-O-dibutyryl cyclic AMP) on the rate of glycolysis, fructose 2,6-bisphosphate concentration and 6-phosphofructo-2-kinase activity, as well as on the rate of 3-O-methyl-D-[14C]glucose uptake. Our results show that, without affecting the rate of 3-O-methyl-D-[14C]glucose accumulation, VIP and cyclic AMP analogues were able to inhibit glucose consumption and L-lactate formation by isolated rat enterocytes. These effects occurred parallel to a significant decrease in the cellular concentration of fructose 2,6-bisphosphate and to a partial inactivation of 6-phosphofructo-2-kinase. These findings support the hypothesis that VIP inhibits glycolysis in rat enterocytes through a cyclic AMP-dependent mechanism.

3-O-Methylglucose↗
PubMed2004

Porcine small intestine submucosa for soft tissue augmentation.

OBJECTIVE: Porcine small intestine submucosa was evaluated as a material for soft tissue augmentation in the hairless guinea pig model. MATERIALS AND METHODS: Small intestine submucosa was formed into strips and rolls and implanted into the dorsum of the hairless guinea pig. The animals were divided into three groups and the implants were evaluated grossly and microscopically for persistence, infection, and inflammation. A total of 116 implants were evaluated grossly. RESULTS: Selected samples from the 1- and 3-month cohorts and all identifiable samples from the 5-month cohort were evaluated microscopically. Some implants were not located, likely due to migration. With one exception, the identified implants in the 5-month cohort exhibited minimal inflammation and appeared well tolerated. The eight-ply small intestine submucosa material appears well tolerated and provided increased soft tissue volume at 5 months. CONCLUSION: Small intestine submucosa may represent an alternative to autologous and homologous materials for soft tissue augmentation.

Animals↗
PubMed1989

Localization and characterization of prostaglandin E1 receptors in rat small intestine.

While prostaglandins of the E series are known to affect several small intestinal functions, their cellular mechanisms are poorly understood. The purposes of our study were to determine whether receptors for PGE are present in rat small intestine and to locate and characterize the receptor binding in the subcellular fractions. Small intestinal binding of prostaglandin E1 was significantly higher than that of prostaglandin E2. Highest receptor binding for prostaglandin E1 was found in the plasma membrane fraction of isolated small intestinal enterocytes. Curvilinearity of prostaglandin E1 binding in plasma membranes upon Scatchard analysis indicated two receptor binding sites in rat small intestine. Competitive binding studies demonstrated that receptor binding was highest for prostaglandins of the E series. These studies are the first to demonstrate specific prostaglandin E1 receptors in different subcellular fractions of rat small intestine. We suggest that receptor binding of prostaglandin E may be an important initial step in the mechanism of prostaglandin-E-induced responses in the small intestine.

Animals↗
PubMed1989

Differentiation of intestinal epithelial cell line (IEC-18) by an acid extract of rat small intestine.

A factor which may induce differentiation of intestinal epithelial cell lines in vitro was found in an acid extract of adult rat small intestine. The addition of a partially purified acetic acid extract of rat small intestine to IEC-18 cell culture dishes increased sucrase activity within 48 h. Thymidine incorporation markedly decreased within 24 h. Significant development of microvilli-like structures was observed on the acid extract-treated IEC-18 cells, compared with controls. This activity of rat acid extract was heat-stable and the apparent molecular weight of the factor was 400-800. These findings suggested that the factor may be related to the epithelial differentiation of rat small intestinal crypt cells.

Animals↗
PubMed1975

Distribution of disaccharidases, alkaline phosphatase, and some intracellular enzymes along the human small intestine.

The longitudinal distribution of various enzymes along the human small intestine was studied by analysis of biopsies from different parts of the small intestine, obtained from 13 patients during shunt-operation for severe obesity. Alkaline phosphatase and 3 glycolytic enzyme activities studied were rather uniformly distributed along the small intestine. Acid beta-galactosidase and hetero beta-galactosidase activities were highest in the proximal small intestine with a gradual decline throughout the intestine. The activity in the distal ileum was about half of the maximum activity. Maltase, isomaltase, sucrase, and trehalase activity had a broad maximum in the proximal and middle small intestine with a rather sharp decrease in the distal ileum. Lactase activity had a more pronounced maximum in the middle intestine with a pronounced decrease towards the proximal and distal ends. The disaccharidase activities in surgical biopsies taken 5 cm distal to the ligament of Treitz were about 10% higher than in peroral biopsies taken just at the ligament.

Adult↗
PubMed1998

Early induction and augmentation of parasitic antigen-specific antibody-producing B lymphocytes in the non-Peyer's patch region of the small intestine.

In this study, B lymphocytes from the small intestine of immunized rats were examined for their expression of specific antibodies against Trichinella spiralis (TS) antigen. The isotypes of the antigen-specific antibodies on B cells were examined via immunofluorescence microscopy. Monoclonal mouse anti-rat IgE, IgG1, IgG2a, IgG2b, IgG2c, IgA and IgM primary antibodies in conjunction with FITC-conjugated goat anti-mouse Ig secondary antibody and XRITC-conjugated 9D4 T. spiralis antigen were used to study the dynamics of the appearance of activated B lymphocytes in the small intestine, Peyer's patch, both the germinal center (PP-GC) and the non-germinal center (PP-NGC), the mesenteric lymph node (MLN), and the spleen. The results demonstrate that activated B cells are elicited by TS in the non-Peyer's patch region of the small intestine to express all isotypes of antibodies against TS antigen. IgG- and IgE-producing cells (Ab-PC) began proliferation only 1 and 2 days after infection, respectively. The strongest response was mounted by the IgE-PC in the lamina propria of the intestine. The response by IgA-PC generated was not only significantly delayed and also much weaker than that of the IgE- and IgG-PC. Peyer's patches failed to be a significant contributor in this immune response. Although this antigen-specific immune response was produced in the MLN and the spleen, it was weaker than that of the small intestine. The study indicates the potential ability of an immunized host to generate an early, yet effective, humoral immunity against T. spiralis in the non-Peyer's patch region of the small intestine."

Animals↗
PubMed1996

Malignant melanomas in the small intestine: a study of 103 patients.

OBJECTIVES: Malignant melanoma shows an unusual predilection to metastasize to the small intestine. A proportion of small bowel melanomas occur without history of an antecedent primary. We evaluated a group of patients with malignant melanoma in the small intestine to further our understanding of this disease. METHODS: We reviewed 103 cases of malignant melanoma in the small intestine (77 surgical resections and 26 autopsies) accessioned at the Armed Forces Institute of Pathology between 1945 and 1991 for demographic, chronological, and pathological features. RESULTS: Mean age at time of primary was 45.6 yr for surgical and 34.1 yr for autopsy cases (p = 0.01). Mean age at time of small intestinal involvement was 52.2 yr for surgical and 42.7 yr for autopsies (p = 0.03). Primary lesions preceded intestinal disease by an average of 5.6 yr for surgical and 2.1 yr for autopsies. The age distribution of surgical patients with and without known primary melanomas at the time of small intestinal melanoma was not significantly different. The same was true for autopsy patients. Using regression analysis, the linear relationship of age at primary melanoma (AAP) on age at small intestinal melanoma (AASI) was given by AAP = 2.30 + 0.85 (AASI), and that of AASI on AAP was given by AASI = 3.94 + 1.02 (AAP) (r = 0.93 and p < 0.0001 for both regressions). CONCLUSIONS: Our data and results support the concept that small bowel involvement by melanoma, even without a known primary, is most probably metastatic. The age at which an unknown primary occurred in cases of intestinal melanoma, or the age at which intestinal metastasis may appear in cases with known primary melanoma, can be estimated. There appear to be two subsets of primary melanoma: one that occurs among younger patients and is more aggressive with rapid metastasis and early death and one that occurs among older patients, is more indolent, and metastasizes less rapidly.

Adult↗
PubMed1994

Does long-term inhibition of gastric acid secretion with omeprazole lead to small intestinal bacterial overgrowth?

OBJECTIVE: Gastric acid secretion and small intestinal motility are the main mechanisms of defense against bacterial overgrowth of the proximal digestive tract. Bacterial colonization of the stomach during gastric acid inhibition has been documented, but is probably without clinical consequence. However, small intestinal bacterial overgrowth can have serious clinical implications with malabsorption and diarrhoea. METHODS: We prospectively investigated small intestinal bacterial overgrowth in 40 patients receiving long-term omeprazole treatment using the [14C]glycocholic breath test. Tests were performed before omeprazole treatment, after 6 weeks treatment with 40 mg o.m. and after 26 weeks treatment with 20 mg; in the test each patient served as his own control. RESULTS: Breath tests, using individual curves, peak values, time at which the peak appeared and the area under the curve, did not differ significantly during treatment from those before treatment. CONCLUSIONS: We conclude that long-term strong inhibition of gastric acid secretion does not lead to small intestinal bacterial overgrowth.

Adult↗
PubMed1998

Small intestine dysmotility and bacterial overgrowth in cirrhotic patients with spontaneous bacterial peritonitis.

Patients with bacterial overgrowth of the small intestine developed spontaneous bacterial peritonitis (SBP) more frequently than patients without bacterial overgrowth of the small intestine. The objective of this study was to determine whether the incidences of small intestine dysmotility and bacterial overgrowth are higher in cirrhotic patients with a history of SBP than in cirrhotic patients without SBP. Forty cirrhotic patients were enrolled in this study. There were 20 patients with a history of SBP and 20 patients without a history of SBP. Small intestine bacterial overgrowth was diagnosed by breath hydrogen test. Small intestine motility was recorded, by a 3-channel solid-state manometric catheter, for 24 hours. There were no statistical differences in age or sex between the two groups. The Child-Pugh scores in the SBP group were higher than in the non-SBP group (10.5 +/- 2.1 vs. 8.1 +/- 1.9, P < .01). The incidence of bacterial overgrowth of the small intestine was higher in the SBP group than in the non-SBP group (70% vs. 20%, P < .01). The amplitude and duration of migrating motor complex (MMC) activity fronts, as well as the number of clusters per hour, were similar in both groups. However, the frequency of MMC activity fronts was higher in the non-SBP group than in the SBP group (4.8 +/- 2.3/24 hours vs. 3.5 +/- 1.2/24 hours, P < .05). In addition, the MMC velocity was significantly higher in the non-SBP group (8.3 +/- 2.6 vs. 5.3 +/- 2.1 cm/min, P < .01). The incidence of bacterial overgrowth of the small intestine was higher in cirrhotic patients with history of SBP than in those without SBP. Small intestine motility dysfunction was more severe in cirrhotic patients with history of SBP. Impaired motility of the small intestine, causing bacterial overgrowth of the small intestine, may be one of the explanations for recurrent SBP in cirrhotic patients.

Adult↗
PubMed2000

Rifaximin versus chlortetracycline in the short-term treatment of small intestinal bacterial overgrowth.

BACKGROUND: Bacterial overgrowth of the small intestine is a condition characterized by nutrient malabsorption due to an excessive number of bacteria in the lumen of the small intestine. Current treatment is based on empirical courses of broad spectrum antibiotics; few controlled data, with respect to the duration and choice of antibiotic drug, exist at present. The recent availability of rifaximin, a non-absorbable rifamycin derivative, highly effective against anaerobic bacteria, prompted us to carry out a randomized, double-blind controlled trial in order to compare its efficacy and tolerability to those of tetracycline, currently considered the first-choice drug. METHODS: In 21 patients affected by small intestinal bacterial overgrowth, fasting, peak and total H2 excretion after ingestion of 50 g glucose and severity of symptoms were evaluated before and after a 7-day course of rifaximin, 1200 mg/day (400 mg t.d.s.), or chlortetracycline, 1 g/day (333 mg t.d.s. ). RESULTS: Fasting, peak and total H2 excretion decreased significantly in the group of patients treated with rifaximin whereas chlortetracycline did not modify these parameters. The H2 breath test normalized in 70% of patients after rifaximin and in 27% of patients after chlortetracycline. The improvement in symptoms was significantly higher in patients treated with rifaximin. CONCLUSIONS: Rifaximin is a promising, easily-handled and safe drug for the short-term treatment of small intestinal bacterial overgrowth.

Adult↗