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At least 1,207 records · Page 67Linked to original sources
PubMed1982

Intestinal absorption of several beta-lactam antibiotics. IV. Binding to the various components in the intestinal mucosa of rat and role in absorption process.

The binding characteristics of zwitterionic and monobasic beta-lactam antibiotics to the components in the intestinal mucosa of rat was investigated. From the binding experiments using the brush border membrane preparation and the insoluble cellular fractions, there was no correlation between the binding behavior and the absorption characteristics. However, there was a highly significant correlation between the affinity to the soluble F1 fraction and the absorption characteristics of these antibiotics. It was also found that the binding of these antibiotics to the other soluble protein fractions were significantly smaller than that to F1 fraction. It was postulated that the binding properties of these antibiotics to soluble F1 fraction play an important role in the absorption process.

Animals↗
PubMed1984

Intestinal absorption mechanism of amino-beta-lactam antibiotics. III. Kinetics of carrier-mediated transport across the rat small intestine in situ.

The transport kinetics of amino-beta-lactam antibiotics was studied by an in situ rat small intestinal recirculating perfusion technique. The disappearance rates of the antibiotics from the perfusing luminal solution followed mixed-type kinetics with saturable and nonsaturable processes. The kinetic parameters were determined. Pharmacokinetic analysis of the time courses of luminal disappearance, tissue accumulation, and blood concentration indicated that the transfer of the antibiotics from the in situ luminal solution to tissue is nearly irreversible. On the assumption that the saturable transport process involves a common carrier for these antibiotics, the predicted extents of mutual inhibition using the in situ kinetic parameters were in good agreement with the experimental values for cephalexin and cephradine. The effects of cephalexin and cefadroxil on the absorption of cyclacillin were also consistent with a common transport mechanism. The dipeptides, carnosine and L-phenylalanylglycine markedly inhibited cyclacillin absorption in a competitive fashion. Furthermore, cyclacillin inhibited the absorption of carnosine. The results indicate that the absorption of amino-beta-lactam antibiotics is closely related with that of dipeptides.

Animals↗
PubMed2002

Contrast-enhanced power Doppler sonography of the intestinal wall in the differentiation of hypervascularized and hypovascularized intestinal obstructions in patients with Crohn's disease.

OBJECTIVE: To use power Doppler sonography to quantify the vascularization in the area of stenosed bowel segments in patients with Crohn's disease and to draw conclusions from these findings with regard to the development of these stenoses. METHODS: The study collective included 11 patients with confirmed Crohn's disease and sonographically visualized stenoses of the small bowel together with intermittent abdominal cramping as a clinical correlate. Power mode examination was repeated after application of a sonographic signal-enhancing agent. Semiquantitative evaluation based on the sonographically indicated degree of vascularization led to the presumptive diagnosis of either inflammatory or cicatricial intestinal obstruction. Sonographic diagnoses were compared with the findings of surgery and subsequent histologic examination or with patients' clinical responses to conservative therapy. RESULTS: Nine of 11 patients underwent surgery within 1 year of examination. All 3 cases in which sonography had facilitated the diagnosis of cicatricial stenosis were confirmed at postoperative histologic examination; similarly, the surgical and histologic findings in the other 6 patients confirmed the sonographic diagnosis of inflammatory stenosis. CONCLUSIONS: Power Doppler sonography in combination with the use of a signal-enhancing agent appears to be effective in the recognition of predominantly cicatricial stenoses in patients with Crohn's disease.

Adult↗
PubMed2006

Segmental defect of intestinal musculature: a rare cause of intestinal obstruction in children.

A 3 years old female child was brought to the emergency department with acute abdomen. Laparotomy disclosed multiple segmental dilatations in the middle third of the ileum which was resected and anastomosed. Post-operative recovery was uneventful. Histopathological findings showed lack of smooth and longitudinal muscles in dilated segments of the intestine with intact mucosa without any evidence of necrosis and inflammation.

Abdomen, Acute↗
PubMed1992

[Mucus models for investigation of intestinal absorption mechanisms. 2. Mechanisms of drug interactions with intestinal mucus].

Using in vitro models previously described [1] mucus retention and mucus diffusion of polar and non-polar drugs were measured. It could be shown that drug interaction with pig intestinal mucus was based on non-specific binding. The pH-dependence of retention by mucus does not confirm electrostatic interaction of drugs with mucus but favour drug distribution to hydrophobic areas within the mucus. High lipophilicity and retention by mucus correlate with low diffusion of drugs through mucus.

Chemical Phenomena↗
PubMed1992

[The effects of dachengqi decoction, shaogan decoction, emodin and sennoside on the histamine level of intestinal mucosa in intestinally obstructed rats].

The experimental intestinal obstruction model was made by partly ligating the ileum in rat. The histamine levels of obstruction groups (8.14 +/- 2.28 micrograms/g) were obviously lower than those of control groups (P < 0.01). After administration of Dachengqi decoction, Shaogan decoction, emodin and sennoside, the levels of histamine were significantly higher than those of obstruction groups, but there were no significant differences as compared with control groups.

Animals↗
PubMed1991

[A preliminary study on substance P and vasoactive intestinal polypeptide contents in intestinal mucosa of chronic diarrhea with splenic weakness].

By means of radioimmunoassay, the mucosal substance P (SP) and vasoactive intestinal polypeptide (VIP) concentration in distal ileum, transverse colon and sigmoid colon in 30 patients of chronic diarrhea with splenic weakness was determined and compared with that in 28 patients of chronic diarrhea without splenic weakness and in 15 controls without chronic diarrhea. In patients of chronic diarrhea with splenic weakness, the SP contents in the mucosa of distal ileum (120.95 +/- 90.70 pg/mg wet weight) was significantly increased compared with that in controls without diarrhea (47.86 +/- 35.49 pg/mg wet weight) and in chronic diarrhea without splenic weakness (52.50 +/- 42.49 pg/mg wet weight), P less than 0.01 and 0.01 less than P less than 0.05 respectively. The VIP contents of sigmoid mucosa in patients of chronic diarrhea with splenic weakness (510.63 +/- 265.22 pg/mg wet weight) was markedly increased in comparison of that in controls without chronic diarrhea (308.67 +/- 204.49 pg/mg wet weight), 0.01 less than P less than 0.05, and was not significantly augmented compared with that in chronic diarrhea without splenic weakness (398.97 +/- 240.80 pg/mg wet weight), but the tendency of increase was present. Our results suggested that the increased SP and VIP in patients of chronic diarrhea with splenic weakness might be closely related to the symptom of chronic diarrhea. According to the general function of VIP, the authors predicted that VIP might play a more important role in the pathogenetic action of chronic diarrhea with splenic weakness.

Adult↗
PubMed1991

[Roles of the sympathetic nervous system in the local release of vasoactive intestinal polypeptide (VIP) from the small intestine of anesthetized dogs].

To investigate roles of the sympathetic nervous system in the local release of VIP, pharmacological alpha (phenoxybenzamine), beta (propranolol) adrenergic blockade or surgical sympathectomy by the ganglionectomy of splanchnic plexus was performed in anesthetized dogs. Portal and venous plasma VIP levels during intrajejunal infusion of 0.1 N HCl solution at a rate 1.5 ml/min for 20 minutes were observed before and after these procedures. The plasma VIP levels during the intrajejunal HCl infusion were significantly increased after blocking of alpha-adrenoceptors and surgical sympathectomy but showed no change after blocking of beta-adrenoceptors. These results suggest the inhibitory mechanism of the sympathetic nervous system on the local release of VIP from the canine small intestine. In addition, the increase of portal blood flow and bile secretion, and the elevation of bicarbonate concentration in the secreted bile during the intrajejunal HCl infusion were significantly higher after surgical sympathectomy than before, and plasma VIP levels were also significantly higher.

Anesthesia↗
PubMed1990

[The cytomorphology of goblet cells of the fetal intestine. Studies of the large intestine of cattle (Bos primigenius taurus)].

In the region of the base of the intestinal crypts undifferentiated goblet cells display a configuration and constellation of organelles and membrane structures that are indicative of their importance for function. These images at this stage of development deliver a scenario of the mechanism of secretory granule production: aggregates of protein vesicles from the "transitional elements" (PALADE) of the granular endoplasmic reticulum are, so to speak, rolled up on the trans side of the Golgi apparatus by inversion of peripheral membrane segments of the innermost Golgi lamellae, thereby forming corpuscles. The origin of the capsulated vacuoles, which contain vesicles as single elements or as conglomerates, is well established. Their capsule consists of a trilaminar external and external and internal membrane; between them lies condensed material of the Golgi apparatus. In the opinion of the present author, the development of the ensheathed vacuoles represents a basic, more general mechanism. In contrast, the further steps of synthesis, for the formation of secretory granules, are more heterogeneous. Condensation of the vesicles and the inner capsular membrane results in the formation of a prosecretory granule, which in the basic element in the process of secretory granule production. The prosecretory granules develop singly or by fusion with other granules to give primary secretory granules. The complexity of this mechanism of secretory granule formation, however, becomes evident when considering the apposition of capsulated vacuoles and prosecretory--primary--secondary secretory granules, of prosecretory and primary secretory granules as well as prosecretory granules and secondary secretory granules. Generally, primary granules show a tendency to become secondary secretory granules or to fuse with them. During maturation of the goblet cells the secretory granules fuse to form larger mucous bodies in the theca by fusion of the laminae of the membranes; a final product, there is a homogeneous mucous mass devoid of membranes.

Animals↗
PubMed1990

Opioid modulation of basal intestinal fluid transport in the mouse: actions at central, but not intestinal, sites.

Central and peripheral sites of opioid action on net basal fluid transport were studied in loops of jejunum in urethane-anesthetized mice. Intracerebroventricular administration of morphine, [D-Ala2, N-MePhe4, Gly-ol]enkephalin (DAMGO), D-Pen2, D-Pen5] enkephalin (DPDPE) or U50,488H produced dose-related increases in net basal intestinal absorption. Intracerebroventricular DAMGO was approximately 2.6, 1278 and 2674 times more potent than morphine, DPDPE and U50,488H, respectively. The increase in net basal fluid absorption mediated by i.c.v. administration of all these compounds, except DPDPE, was antagonized in a dose-related manner by coadministration of i.c.v. naloxone, an opioid antagonist which did not produce any effects when given alone. Neither the increase in net basal fluid absorption produced by DPDPE nor the fluid transport effects produced by the other agonists tested was antagonized by the delta antagonist, N,N-diallyl-Tyr-alpha-aminoisobutyric acid [( Aib]-Aib-Phe-Leu-OH) and no effects were observed with this delta antagonist alone. Intracerebroventricular administration of beta-funaltrexamine (18.8 nmol, 4 hr before testing) blocked the i.c.v. effects of DAMGO, but not those of U50,488H. In contrast to the effects seen following i.c.v. administration of these agonists, no changes in net basal fluid transport were obtained by the i.p. route for DAMGO, DPDPE, [D-Ala2,D-Leu5]enkephalin, [D-Ala2, Met5]enkephalinamide or U50,488H; of the compounds tested, only morphine produced an increase in net basal fluid absorption after i.p. administration. The effects of i.c.v. or i.p. morphine were blocked by i.c.v. SR 58002C, a quaternary opioid antagonist which had no effects alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesics↗
PubMed1990

[Experimental studies of the possibilities of radioimmunodetection of cancer of the large intestine by subcutaneous administration of iodinated antibodies to intestinal antigen beta1-MA].

131I- and 125I-labeled rabbit antibodies (AB) to the specific human intestinal beta 1MA were administered sc and iv to nude mice xenografts of human colon carcinoma. A study was made of the pharmacokinetics of labeled AB in the recipients' organs and tissues, measuring the radioactivity of tissue specimens on days 2, 3, 4 and 7 after injection with a gamma-counter, calculating specific radioactivity and accumulation indices. Tumors were visualized with a gamma-camera and a scanner. Proceeding from the comparison of the results of sc and iv administration of iodinated AB, a conclusion has been made of the applicability of sc injections of the agent for immunoscintigraphy.

Animals↗
PubMed1989

[Effect of intestinal necrosis in the postoperative prognosis of acute intestinal obstruction. Experiences with 123 cases surgically treated at Bujumbura Hospital (Burundi)].

The review of 123 cases of patients operated for acute intestinal obstruction emphasises the principal epidemiological factors and the necessity of a very brief delay between the first signs of obstruction and the therapeutic procedure. The high mortality in the series (25%) was due to the high incidence of necrosis observed (40%).

Acute Disease↗
PubMed1987

Vasoactive intestinal peptide and intraocular pressure: adenylate cyclase activation and binding sites for vasoactive intestinal peptide in membranes of ocular ciliary processes.

Vasoactive intestinal peptide (VIP)-responsive adenylate cyclase and VIP binding sites were investigated in membranes prepared from ciliary processes dissected from albino rabbit eyes. High-affinity binding sites for VIP (Kd, 0.95 nM; 607 fmol/mg of protein), in addition to beta adrenergic sites labeled by dihydroalprenolol (Kd, 0.48 nM; 123 fmol/mg of protein), were present. Activation of adenylate cyclase by VIP had a Ka of 65 nM, and the maximal response was 3.3-fold greater than that for I-isoproterenol (Ka, 102 nM). A peptide fragment of VIP (sequence 10-28) was inactive in all assays and did not inhibit VIP-stimulated adenylate cyclase at 10 microM. Responses to VIP and isoproterenol in combination were additive at lower doses but less than additive at maximal doses. Responses to VIP in combination with a low dose of forskolin (0.1 microM) were potentiated at all dose levels, whether assays were done in presence of MgCl2 or MnCl2. VIP- and forskolin-activated adenylate cyclase was associated with the nonpigmented epithelial cell fraction and not with pigmented epithelial cells separated on Percoll density gradients after dissociation of cells from processes by collagenase digestion. Intravitreous injection of 10 nmol of VIP into the rabbit eye caused a maximal reduction in intraocular pressure at 40 to 50 hr lasting beyond 72 hr. VIP-responsive and beta adrenergic-responsive adenylate cyclase are present on the same cell type (nonpigmented epithelial cells) and appear to share components of the adenylate cyclase system in the same membrane. VIP may participate in the physiologic regulation of aqueous humor secretion at the level of the epithelial cell membrane.

Adenylyl Cyclases↗
PubMed1987

Characterization of vasoactive intestinal peptide receptors by a photoaffinity label. Site-specific modification of vasoactive intestinal peptide by derivatization of the receptor-bound peptide.

The biological effects of vasoactive intestinal peptide (VIP) are mediated by binding to a membrane-bound receptor. Probes designed to trap this receptor by binding to it in a covalent way may suffer from a greatly reduced affinity. We report here, for the VIP receptor, the use of a photoaffinity probe obtained by derivatization of receptor-bound VIP with para-azidophenylglyoxal. This method protected the parts of the molecule essential for receptor binding. The VIP derivative thus obtained became covalently linked when irradiated. In the dark, however, it exhibited normal VIP-like behavior and retained its biological activity. This derivatization method might be generally applicable when hormone analogues have to be prepared without loss of receptor affinity. Receptor characterization studies on liver plasma membranes showed the presence of high- and low-affinity binding sites with KD = 0.1 and 5 nM, respectively. Treatment of membranes with dithiothreitol causes loss of high-affinity binding. The high-affinity site, trapped by the photoaffinity probe, resolved into two molecular mass forms, 50 and 200-250 kDa. Reduction of the receptor-probe complex left the 50-kDa form intact, whereas the amount of the 200-250-kDa form greatly diminished. We demonstrate the importance of the presence of disulfide bonds in one of the molecular forms involved in high-affinity binding.

Affinity Labels↗
PubMed1979

[Intestinal invagination caused by lipoma of the small intestine].

A case of ileo-colic invagination caused by lipoma of the last loop of the small intestine is reported. The anatomo-clinical features of this neoformation are illustrated and stress is laid on certain special aspects: the rarity (about 300 cases have been described in the literature), the lack of symptomatology and its insidious development without pathognomonic sign up to the occurrence of occlusive episodes. The surgery carried out and the result obtained are reported.

Adult↗
PubMed1980

Vasoactive intestinal peptide- and adrenocorticotropin-stimulated adenyl cyclase in cultured adrenal tumor cells: evidence for a specific vasoactive intestinal peptide receptor.

Vasoactive intestinal peptide (VIP) has been shown to be steroidogenic in monolayer cultures of a murine adrenal tumor but must be present at concentrations about 100-fold greater than ACTH to elicit the same degree of stimulation. Both peptides enhanced cAMP synthesis, although there was again a difference of 2 orders of magnitude in the dose-response curves. In contrast, VIP stimulated adenyl cyclase activity of tumor membranes in the same concentration range as ACTH. Maximum activity with VIP was less than that with ACTH in the absence or presence of a saturating amount of guanylyl imido-diphosphate. Saturating amounts of both peptides stimulated activity to levels greater than that with either ACTH or VIP alone, but the activity was not fully additive. An o-nitrophenyl sulfenyl derivative of ACTH inhibited ACTH-stimulated adenyl cyclase activity but not VIP-stimulated activity. Low concentrations of calcium potentiated the ability of submaximal doses of ACTH to stimulate adenyl cyclase but had no effect on the response to VIP. Concentrations of secretin or glucagon comparable to that of VIP did not stimulate steroidogenesis in intact cells. These data suggest that VIP may bind to a unique receptor which may be distinct from that of ACTH.

Adenylyl Cyclases↗
PubMed1983

[Intestinal anastomosis using the invagination technic without intestinal wall sutures in small animals].

After resection of a part of the ileac section of the gut, end-to-end anastomosis was performed in fifteen healthy test dogs and two cats by the method of the invagination of the cranial segment of the gut into the caudal segment without gut wall suture. Healing was controlled in several time intervals after operation (by clinical and histopathological examination). The main advantage of this technique is the speed and easiness of operation and a small tissue reaction with the formation of a minimum amount of adhesions, combined with the fact that by this method the passage of the intestines is not reduced. On the basis of the results and literary data, this technique is recommended for clinical use mainly in those cases when, owing to an alteration of the general health state, minimum time is left for an operation and, thereby, for a narcosis. However, the course of healing should be further studied in patients with an indication of enterectomy.

Animals↗