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N Imeryüz

Publications and source records attributed to N Imeryüz.

8 recordsLinked to original sources
PubMed2001

Gender influence on jejunal migrating motor complex.

The role of gender and the menstrual cycle in small bowel motility has not been clearly elucidated. Jejunal motility was recorded with a nasojejunal catheter incorporating five solid-state pressure transducers in ambulatory menstruating women and men of comparable age over 24 h. All women were studied twice, in the early follicular (early-F) and midluteal (mid-L) phases of the menstrual cycle, verified by determining serum levels of gonadal steroids and gonadotropins. The propagation velocity of phase III was slow and the contraction amplitude was high in both menstrual cycle phases compared with men, and these parameters were correlated with serum estrogen levels in the mid-L phase. In the early-F phase, migrating motor complex (MMC) cycle duration during sleep was long compared with other groups and positively correlated with estrogen concentrations, whereas in the mid-L phase MMC cycle duration during sleep was negatively correlated with serum progesterone levels. In all groups, the frequency of phase III contractions was low and the intercontractile interval measured from pressure peak to peak was long during sleep compared with the awake state. Postprandial motility did not display gender difference in any parameter examined. The results demonstrate that the majority of patterns of motility are similar in menstruating women and men, whereas certain aspects of the MMC, most conspicuously propagation velocity and phase III contraction amplitude, differ. We have also documented circadian variation of phase III contraction frequency in both women and men.

Adult↗
PubMed2001

Inhibition of gastric emptying by acarbose is correlated with GLP-1 response and accompanied by CCK release.

We investigated the effect of acarbose, an alpha-glucosidase and pancreatic alpha-amylase inhibitor, on gastric emptying of solid meals of varying nutrient composition and plasma responses of gut hormones. Gastric emptying was determined with scintigraphy in healthy subjects, and all studies were performed with and without 100 mg of acarbose, in random order, at least 1 wk apart. Acarbose did not alter the emptying of a carbohydrate-free meal, but it delayed emptying of a mixed meal and a carbohydrate-free meal given 2 h after sucrose ingestion. In meal groups with carbohydrates, acarbose attenuated responses of plasma insulin and glucose-dependent insulinotropic polypeptide (GIP) while augmenting responses of CCK, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY). With mixed meal + acarbose, area under the curve (AUC) of gastric emptying was positively correlated with integrated plasma response of GLP-1 (r = 0.68, P < 0.02). With the carbohydrate-free meal after sucrose and acarbose ingestion, AUC of gastric emptying was negatively correlated with integrated plasma response of GIP, implying that prior alteration of carbohydrate absorption modifies gastric emptying of a meal. The results demonstrate that acarbose delays gastric emptying of solid meals and augments release of CCK, GLP-1, and PYY mainly by retarding/inhibiting carbohydrate absorption. Augmented GLP-1 release by acarbose appears to play a major role in the inhibition of gastric emptying of a mixed meal, whereas CCK and PYY may have contributory roles.

Acarbose↗
PubMed1998

The distribution of HLA-DRB alleles in ulcerative colitis patients in Turkey.

Recently described distinct associations of HLA class II genes with ulcerative colitis (UC) suggest a genetic heterogeneity for disease susceptibility. In this study, HLA-DRB alleles of UC patients (n = 59) from Turkey were investigated and compared with healthy controls (n = 244). Using molecular genotyping by polymerase chain reaction (PCR) and sequence-specific oligonucleotide hybridization, we have shown a positive association of UC patients with the HLA-DRB1*1502 allele (10/59 vs. 16/244; P = 0.02; OR: 2.9) and a negative association with the DRB1*13 allele (7/59 vs. 64/244; P = 0.03; OR: 0.38) compared to controls. HLA-DRB1*0701 was significantly increased in perinuclear antineutrophil cytoplasmic antibody (pANCA)-positive UC patients compared to pANCA-negative patients (8/32 vs. 0/27; P = 0.005), whereas DRB1*1502 was observed more frequently in pANCA-negative patients (8/27 vs. 2/32; P = 0.03). These results extended the reported positive association of DRB1*1502 with UC to another population and supported the genetic susceptibility associated with HLA genes for disease development.

Adult↗
PubMed1998

Corticosteroid therapy augments gastroduodenal permeability to sucrose.

OBJECTIVE: The aim of the present study was to investigate whether corticosteroid therapy alters gastroduodenal mucosal permeability and whether permeability alteration is associated with macroscopic mucosal damage. METHODS: Eight patients taking oral corticosteroid therapy (total prednisone-equivalent dose, 1.5+/-0.1 g; duration, approximately 30 days), nine patients with multiple sclerosis taking high-dose intravenous methyl-prednisolone therapy (total dose, 11.7+/-0.5 g; duration, approximately 9 days), and 20 age- and gender-matched controls were studied. Gastroduodenal permeability was determined using sucrose as a site-specific permeability probe. Five-hour urine was collected after ingesting 100 g of sucrose and its urinary excretion rate was measured using high-pressure liquid chromatography. Gastroduodenal endoscopy was performed before steroid therapy to exclude subjects with evidence of macroscopic mucosal lesions. The sucrose test and endoscopy were repeated after completion of corticosteroid therapy. RESULTS: The urinary sucrose excretion rates were similar in the control group and in patient groups before corticosteroid therapy. The median excretion rate of sucrose increased four (one to 28)- and eight (two to 35)-fold, respectively, as compared with pretreatment values in patients taking oral steroid and high-dose intravenous methyl-prednisolone therapy (p < 0.01). Considering all patients together, subjects who received a mean prednisone-equivalent dose of 8.4+/-1.5 g exhibited mucosal lesions, whereas patients who received 3.3+/-1.8 g did not (p = 0.06). The post-therapy increments in sucrose excretion rates were associated with neither the presence of macroscopic lesions nor with the total steroid dose received. CONCLUSIONS: Corticosteroid therapy augments gastroduodenal permeability and high doses are associated with macroscopic mucosal lesions. Steroid-induced permeability increase does not appear to be associated with the presence of macroscopic mucosal lesions.

Administration, Oral↗
PubMed1998

Interaction of omeprazole with enteric-coated salicylate tablets.

OBJECTIVE: Enteric-coated tablets are designed to resist gastric fluids and to disrupt and dissolve in the alkaline medium of the small intestine. Main objective of the present study was to investigate whether the increase in gastric pH due to omeprazole treatment alters the release rate of a drug from enteric-coated formulation. To this end, we have compared the single dose pharmacokinetics of a single-unit enteric-coated salicylate to that of uncoated acetylsalicylic acid tablets in the presence and absence of omeprazole treatment. METHODS: Study was carried out according to 4 x 4 Latin square design. Eight healthy subjects received either uncoated acetylsalicylic acid tablets or single-unit enteric-coated sodium salicylate tablets alone or following 4 days of treatment with single-dose 20 mg omeprazole, and blood samples were collected for 24 hours. Serum salicylate levels were determined by the modified spectrophotometric method of Brodie et al. [1994]. RESULTS: Salicylate was absorbed rapidly from uncoated tablets but absorption of salicylate from enteric-coated tablets was delayed, as expected. According to our results, omeprazole treatment did not influence the bioavailability from uncoated acetylsalicylic acid tablets but the absorption rate of salicylate from enteric-coated tablets was increased significantly. CONCLUSION: Findings of the present study demonstrate that omeprazole treatment significantly increases the rate of absorption of single-unit enteric-coated medication. Enhanced rate of absorption is most probably due to an early disruption of enteric coating and the intragastric release of the drug secondary to an omeprazole-mediated increase in gastric pH. The results of the present study also corroborate previous findings which have demonstrated highly variable absorption of enteric-coated single units.

Adult↗
PubMed1997

Glucagon-like peptide-1 inhibits gastric emptying via vagal afferent-mediated central mechanisms.

Exogenous administration of glucagon-like peptide-1-(7-36) amide (GLP-1), an insulinotropic hormone, inhibits gastric emptying and acid secretion in humans. The role of GLP-1 as a regulator of gastric function is elusive. In gastric fistula rats, vagal afferent denervation and peripheral administration of the GLP-1 receptor antagonist exendin-(9-39) amide enhanced emptying of a glucose meal, whereas intracerebroventricular exendin was ineffective. The rate of saline emptying was attenuated by peripheral as well as by central administration of GLP-1, and pretreatment with exendin by the respective routes reversed the inhibition by GLP-1. Vagal afferent denervation abolished the central and peripheral action of GLP-1 on gastric emptying. Neither peripheral cholinergic nor adrenergic blockade altered the delay of methyl cellulose meal emptying by intracisternal GLP-1 injection. Acid secretion in conscious pylorus-ligated rats was inhibited by intracisternal GLP-1 administration, whereas systemic GLP-1 was ineffective. These results support the notion that GLP-1 receptors participate in the central and peripheral regulation of gastric function. Furthermore, vagal afferent nerves mediate the inhibitory action of GLP-1 on gastric motor function. GLP-1 may be a candidate brain-gut peptide that acts as a physiological modulator of gastric function.

Animals↗
PubMed1994

Pericardial and pulmonary involvement in rheumatoid arthritis in Turkey.

Pericardial and lung involvement in rheumatoid arthritis (RA), suspected to be less severe in a developing nation (Turkey), have been evaluated. We have studied clinical, echocardiographic and pulmonary findings (radiological and functional) in 93 consecutive Turkish patients with definite/classical RA. Findings were compared with those of a group of patients with osteoarthritis or local rheumatological conditions (n = 60) in a blind protocol. Fifty patients with systemic lupus (SLE) were studied as a high risk control group for pericardial involvement. While pericardial disease was detected in 5.5% (5/90) of RA patients, it was detected in 6.6% (4/60) of the control patients. SLE patients had a 26% (13/50) prevalence. Interstitial lung disease was found in 27.7% of RA patients but it was present in 6.6% (4/60) of the control patients. We observed that a group of patients with RA in Turkey had a low prevalence of pericardial disease. This is further evidence that RA has a mild course in developing countries.

Adult↗