Biomedical subjects

M Deniz

Publications and source records attributed to M Deniz.

7 recordsLinked to original sources

PubMed2004

Blood flow alterations in TNBS-induced colitis: role of endothelin receptors.

OBJECTIVES: The aim of the present study was to investigate the time dependent changes in hemodynamic parameters and to assess the role of endothelin (ET) receptors in trinitrobenzene sulfonic acid (TNBS) induced colitis. MATERIALS: Inferior mesenteric artery (IMA) hemodynamics, myeloperoxidase activity (MPO) and damage scores were measured immediately or 1, 3, 5 and 14 days after colitis. TREATMENTS: Another group of rats received a nonselective ET receptor antagonist bosentan (30 mg/kg/day), ET-A receptor antagonist BQ485 (60 microg/rat/day) or ET-B receptor antagonist BQ788 (60 microg/rat/day) prior to and on the 1st, 2nd and 3rd days after TNBS administration. RESULTS: IMA flow significantly increased at 90 min followed by a substantial decrease through days 1-5. Tissue MPO activity and macroscopic damage score increased on 1st day after the induction of colitis and remained elevated 3, 5 and 14 days following colitis. Treatment with bosentan or ET-A receptor antagonist largely prevented the colitis-induced reduction in blood flow and tissue injury whereas ET-B receptor antagonist did not attenuate tissue injury or reductions in blood flow. CONCLUSIONS: Our results demonstrate that time-dependent abnormalities occur in IMA hemodynamics following TNBS administration. Our findings also indicate that ET-A receptors but not ET-B receptors play an important role in the colonic inflammation following TNBS administration.

Animals↗

PubMed2003

Morphologic study of left ventricular bands.

The presence of left ventricular bands has drawn attention to their possible clinical importance, though there are no concrete data to support their role in serious clinical diseases. We have investigated the incidence, location, microscopic and macroscopic structure of left ventricular bands in the human and animals. We examined 100 hearts: 28 human and 72 animal (dog, goat, sheep). Left ventricular bands were present in 13 of 28 (46%) human hearts and 62 of 72 (86%) animal hearts. The bands usually extended from the interventricular septum to the free walls in human hearts and from the papillary muscles to the interventricular septum in animal hearts. They were composed of muscle tissue in various proportions in human and dog hearts, and of connective and conductive tissue in sheep and goat hearts.

Anatomy, Comparative↗

PubMed2003

Echocardiographic and morphologic examination of left ventricular false tendons in human and animal hearts.

False tendons are thin, fibrous or fibromuscular structures that traverse the cavity of the left ventricle with no connection to the valvular cusps; they may be single or multiple. We retrospectively analyzed echocardiograms for the prevalence of false tendons in the hearts of 368 (231 male, 137 female) newborns, infants, and children (mean age = 6.28 +/- 4.32 years) who were referred for echocardiography because of suspected acquired or congenital heart disease, but in whom no cardiac pathology was found. In addition, we studied the prevalence of false tendons in 90 hearts from three species of animals (dog, sheep, goat) and eight cadaveric human hearts. In our echocardiographic study, false tendons were detected in 97 of 368 hearts (26.4%). In our gross morphologic studies, false tendons were observed in most of the animal and human hearts: they were present in 5 of 8 (62.5%) human hearts, 14 of 20 (70%) dog hearts, 41 of 50 (82%) sheep hearts, and 16 of 20 (80%) goat hearts. The overall prevalence in animal hearts was 71 of 90 (78.8%). Histologic examination showed the false tendons to be composed of cardiac muscle, blood vessels, fibrous tissue, and Purkinje cells. The possible role of false tendons in innocent murmurs, cardiac rhythm disorders, or left ventricular dysfunction is discussed.

Adolescent↗

PubMed2001

The effects of GnRH analogues and antiandrogenes in preventing the gonadotoxic effects of COPP chemotherapy.

BACKGROUND: In this study we aimed to discuss whether the gonadal suppression is effective or not in preventing the gonadal toxic effects of some chemotherapeutics. METHODS: Forty Sprague-Dawley adult male rats were randomised into 4 groups, each consisting of 10. No drugs were given to the first group. The second group received GnRH agonist and antiandrogen, the third group received COPP chemotherapy protocol and the last group received COPP together with GnRH agonist and antiandrogen. Ninety days after drug application we sacrificed all rats. Total body weight, testicular weight and testicular size measurements were all recorded. All testicular tissues were examined histologically for the ratio of active seminiferous tubules. RESULTS: There was no difference in total body weight. The weight and measurements of testicular tissues were decreased in-group 3 and 4 when compared with 1 and 2. The amount of active seminiferous tubules was significantly less in the third group. CONCLUSIONS: As a conclusion we think that gonadal suppression applied during chemotherapy regimen could decrease the testicular toxic effects of chemotherapeutic but more clinical investigations needed for routine application.

Androgen Antagonists↗

PubMed2000

Cefaclor, a cephalosporin antibiotic, delays gastric emptying rate by a CCK-A receptor-mediated mechanism in the rat.

Studies in vitro suggest that cephalosporin antibiotics release the gut hormone cholecystokinin. Cholecystokinin is known to inhibit gastric emptying. Here we examine the effects of cefaclor on gastric emptying and intestinal motility. Male Sprague-Dawley rats were fitted with gastric cannulas. Following a 3-week recovery, the rate of gastric emptying of saline, peptone (4.5%) or cefaclor was determined after instillation into the gastric cannula, while intestinal transit was measured by using the propagation of arabic gum + charcoal mixture given intraduodenally. Gastric emptying of saline was significantly delayed by the addition of cefaclor (3, 10, 30 or 100 mM). The CCK-A antagonist SR-27897B (1 mg kg(-1), i.p.) reversed the delay induced by 10 mM cefaclor, whereas the CCK-B antagonist CI-988 (1 mg kg(-1), i.p.) had no significant effect. In capsaicin-treated rats, 10 mM cefaclor emptied more rapidly than in vehicle-treated animals. Thirty-minute intestinal transit was increased at 30 and 100 mM of cefaclor, while the gastric acid secretion following cefaclor instillation was no different than the group which received saline. The cephalosporin antibiotic cefaclor appears to be a potent stimulant of CCK release from gut endocrine cells, resembling the effects of peptone. Cefaclor delays gastric emptying via capsaicin-sensitive afferent pathways, which involve CCK-A receptor interaction.

Animals↗

PubMed1999

Calcitonin treatment in osteoectasia with hyperphosphatasia (juvenile Paget's disease): radiographic changes after treatment.

Osteoectasia with hyperphosphatasia is a rare skeletal disorder, characterised by demineralisation and expansion of tubular bones and elevated serum alkaline phosphatase. We present a girl diagnosed as having osteoectasia with hyperphosphatasia who had swelling of phalanges of both hands and motor retardation. She was treated with synthetic human calcitonin. Clinical and radiological findings showed remarkable improvement after 2 years' treatment.

Acid Phosphatase↗

PubMedDate not supplied

Morphological alterations in small intestine of rats with myenteric plexus denervation.

We aimed to investigate the effect of myenteric denervation by benzalkonium chloride (BAC) on small intestine morphology in the rat, and whether segmental myenteric denervation alters morphology elsewhere in the small intestine. Forty male Sprague-Dawley rats were equally divided into 4 groups: control (0.9% NaCl); denervation (0.062% BAC); chemical inflammation (5% acetic acid), and intraluminal stasis produced by partial obstruction. 28 days after operation tissue samples were taken from the treated segment, 10 cm distal to the treated segment, and 20 cm proximal to the treated segment. Morphological changes and the number of ganglion cells were examined under the light microscope. BAC application reduced the number of myenteric neurons by 85% in the treated segment. Denervation increased villus height and crypt depth in the treated and proximal segments. But changes in muscle thickness were seen throughout the intestine. As a result, although myenteric plexus denervation caused mucosa morphology in the treated and proximal segments, it caused smooth muscle changes throughout the small intestine.

Animals↗