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Biomedical subjects

Y Ergün

Publications and source records attributed to Y Ergün.

14 recordsLinked to original sources
PubMed2005

Differential effects of nifedipine and verapamil on non-adrenergic non-cholinergic relaxations at different levels of active tone: assessment of the contribution of nerve-derived hyperpolarizing factor.

1. The objective was to investigate a possible contribution of a nerve-derived hyperpolarizing factor to the differences between non-adrenergic non-cholinergic (NANC) nerve-mediated relaxations in different states of active tone in the rat gastric fundus. 2. NANC relaxations induced by electrical field stimulation (ES: 0.1, 0.5 and 1 Hz; 25 V; 1 ms; 10 s) in 40% contracted strips (S40) were greater when compared with those in 80% contracted strips (S80). 3. ES-induced relaxations were effectively attenuated by N(omega)-nitro-L-arginine (L-NNA; 100 microm) in S40 and S80. Percentage reduction of the responses obtained in the presence of L-NNA in S40 group was less than that of S80. 4. In S40 group, nifedipine (0.5-1 microm) and verapamil (0.5-1 microm) inhibited the responses to 0.1 and 0.5 Hz. Nifedipine (1 microm) and verapamil (0.5 microm) caused no change in the responses to ES in S80. 5. In S40, when L-NNA (100 microm) and nifedipine or verapamil, either in 1 microm concentration, were administered together, the inhibition on the electrical relaxations were more than that of each drug alone. 6. In conclusion, NANC nerve-mediated relaxations are increased when studied in an active state of 40%, and a factor, sensitive to nifedipine seems to be responsible for this distinction.

Animals↗
PubMed2001

The influence of nitric oxide donors on the responses to nitrergic nerve stimulation in the mouse duodenum.

We investigated whether exogenous nitric oxide (NO) donors have a prejunctional and/or postjunctional inhibitory effect on the nitrergic responses and whether this inhibitory effect was mediated by NO itself and in part, by cyclic GMP in mouse duodenal strips. N(omega)-nitro-L-arginine inhibited relaxations induced by electrical field stimulation of nitrergic nerves, but not those with acidified NaNO2. Furthermore, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) inhibited both types of relaxations while 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) and N-ethylmaleimide were ineffective. NO donors, nitroglycerin and sodium nitroprusside, inhibited relaxations induced by nitrergic nerve stimulation, but not those with acidified NaNO2. Hemoglobin, exogenous Cu(2+)/Zn(2+) superoxide dismutase, diethyldithiocarbamic acid and pyrogallol did not influence the relaxation with nitrergic nerve stimulation. However, hemoglobin, diethyldithiocarbamic acid, pyrogallol and diethyldithiocarbamic acid plus pyrogallol attenuated the inhibitory effect of NO donors on relaxation with nitrergic nerve stimulation, and exogenous superoxide dismutase potentiated this inhibitory effect. Moreover, nitrergic nerve-mediated relaxations were inhibited by 8-bromo-cyclic GMP, but not by 8-bromo-cyclic AMP. These results suggest that exogenous NO donors have a prejunctional inhibitory effect on the nerve-mediated nitrergic relaxation and that the inhibitory effects of nitroglycerin and sodium nitroprusside are NO-dependent, but not related to NO metabolites such as peroxynitrite or a nitrosothiol intermediate. However, a contribution of S-nitrosothiol formed intracellularly cannot be entirely ruled out. Also, this prejunctional inhibition is mediated, at least in part, by the cyclic GMP, but not the cyclic AMP, pathway.

Animals↗
PubMed2001

Involvement of nitric oxide in non-adrenergic non-cholinergic relaxation and action of vasoactive intestinal polypeptide in circular muscle strips of the rat gastric fundus.

We examined the characteristics of the non-adrenergic non-cholinergic (NANC) nerve induced relaxation and the possible interaction between nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) on the basal tone of the circular muscle of the rat gastric fundus. Electrically induced NANC relaxations were partly inhibited by N(omega)-nitro-L-arginine (100 microM), whereas sodium nitroprusside (SNP; 10 microM) and VIP (5 nM) induced relaxations were not affected. 2-Amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT; 5 microM) also inhibited the responses to electrical stimuli to a similar extent as N(omega)-nitro-L-arginine but not VIP. However, AMT plus N(omega)-nitro-L-arginine did not give an additional inhibition above that of each drug alone on NANC relaxations, and dexamethasone (10 microM) had no effect on NANC nerve induced relaxations. 1H-[1,2,4,]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 microM), a selective inhibitor of guanylate cyclase, abolished the responses to NANC nerve stimulation and SNP, while VIP responses were not influenced. N-ethylmaleimide (100 microM), an adenylate cyclase inhibitor, attenuated relaxations to NANC nerve stimulation, VIP and isoproterenol (1 nM), while having no effect on those to SNP, but in combination with N(omega)-nitro-L-arginine, there was no additional inhibition on the responses to nerve stimulation. Alpha-chymotrypsin (10 u ml(-1)) severely diminished VIP induced relaxations, but did not reduce electrical responses. In conclusion, these results suggest that NO is involved in the relaxations induced by short-term electrical stimulation. However, another possible unidentified transmitter that can trigger the accumulation of cyclic GMP is not entirely ruled out and there is no interaction between NO and VIP in the circular muscle strip of the rat gastric fundus, even in the basal state of the tissue.

Adenylyl Cyclase Inhibitors↗
PubMed2001

4-Methylcarbazole-3-carboxylic acid.

The title compound, C(14)H(11)NO(2), consists of a carbazole skeleton with carboxylic acid and methyl groups at positions 3 and 4, respectively. Molecules are linked about inversion centres by O-H.O hydrogen bonds [O.O 2.620 (3) A] to form centrosymmetric dimers.

Journal Article↗
PubMed2001

Evidence for the interaction between nitric oxide and vasoactive intestinal polypeptide in the mouse gastric fundus.

The involvement of nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) in nonadrenergic noncholinergic (NANC) nerve-induced relaxation and the interaction between NO and VIP were investigated in the mouse gastric fundus. N(omega)-nitro-L-arginine (L-NOARG; 100 microM) completely inhibited the NANC relaxations induced by electrical stimulation (ES) (0.5, 1, 2, 4, and 8 Hz; 25 V; 1 ms; 15-s trains). Hemoglobin (20 microM), hydroxocobalamin (100 microM), and 1H-[1,2,4,]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 microM) diminished ES-induced relaxations, but alpha-chymotrypsin (10 U/ml) and VIP antiserum (1/200 dilution) had no effect on NANC relaxations. L-NOARG (100 microM) did not have any effect, whereas ODQ (10 microM) attenuated sodium nitroprusside (SNP; 100 nM)-induced relaxations. alpha-Chymotrypsin (10 U/ml) had no effect on the response to SNP. Furthermore, alpha-chymotrypsin (10 U/ml) abolished and VIP antiserum (1/200 dilution) diminished VIP (50 nM)-induced relaxations. L-NOARG (100 microM) caused an inhibition of VIP-induced relaxation that was reversed by L-arginine (1 mM) but not by D-arginine (1 mM). Similarly, ODQ (10 microM) inhibited the responses to VIP. 2-Amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (5 microM) had no effect on these relaxations. L-NOARG (100 microM) and ODQ (10 microM) did not affect isoproterenol (10 nM)-induced relaxations. In conclusion, these results provide evidence that NO is involved in NANC nerve-induced relaxation and the participation of VIP (and related neuropeptides) cannot be excluded in causing relaxation of mouse gastric fundus muscle strips. These findings support the idea that VIP directly stimulates the production of NO by increasing NOS activity and thereby activating soluble guanylyl cyclase in smooth muscle.

Adrenergic beta-Agonists↗
PubMed2000

Possible postsynaptic action of aminoglycosides in the frog rectus abdominis.

The present study was undertaken to investigate the postsynaptic effects of aminoglycosides on contractions evoked by acetylcholine (ACh), KCl, electrical field stimulation (EFS) and Na(+)- and Ca(2+)-free Ringer solution with 0.2 mM Na2 EDTA (NaFCaFR) in the isolated frog rectus abdominis. Neomycin inhibited contraction elicited by ACh, NaFCaFR, and EFS at the higher frequencies (8 and 10 Hz) but not those elicited by KCl and EFS at the lower frequencies (2, 3 and 5 Hz). D-tubocurarine inhibited ACh-induced contractions in a concentration-dependent manner. In addition, drug reduced EFS-evoked contractions to a limited extent. Lower concentrations (10(-5), 5 x 10(-5), 10(-4), 2 x 10(-4) and 3 x 10(-4) M) but not higher concentrations (4 x 10(-4) and 5 x 10(-4) M) of methoxyverapamil exhibited a concentration-dependent inhibitory action on NaFCaFR-induced contractions. Similar inhibitions of the same type of contraction were displayed by aminoglycosides (neomycin, streptomycin, netilmycin, gentamycin and amikacin). These results suggest that in addition to their antagonistic action on nicotinic receptors in the frog rectus abdominis, aminoglycosides may exert stabilizing effects on some functional components contributing to contractions at the membrane.

Acetylcholine↗
PubMed1998

Complications of radical hysterectomy: clinical experience of 115 early stage cervical cancers.

We evaluated the clinical experience of 115 women with early stage cervical cancer who had been operated in our Gynecologic Oncology Clinic. Of these, 85 were in stage I, and 30 in stage II. Intraoperative complications occurred in 16 patients including 3 cases concerning bladder, 1 ureter, 1 aorta, 5 v.cava inferior, 1 internal iliac a., 3 internal iliac v., 1 obturator nerve and 1 rectovaginal septum hematoma formation. Postoperative complications were observed in 38 patients. These were 14 bladder dysfunctions, 10 lymphocyst formations, 6 urinary infections, 12 wound infections, 3 pelvic infections, 2 eviscerations and 1 incisional hernia. However, no death occurred due to intraoperative or postoperative complications. Pelvic lymph node metastases were observed in 32 patients of whom 17 had only unilateral involvement, most often in the obturator region. Para-aortic lymph node metastases were diagnosed in 4 patients, all of whom were in stage II.

Blood Vessels↗
PubMed1997

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of choledochal cysts.

Choledochal cysts are an uncommon anomaly of the biliary system manifested by cystic dilatation of the extra or intrahepatic biliary tree or both. It is most frequently found in Orientals and in females. Endoscopic retrograde cholangiopancreatography is a valuable imaging technique in the diagnosis of choledochal cysts in adults. Additionally, in selected cases, a choledochocele may be effectively managed by endoscopic sphincterotomy. We present clinical and endoscopic findings of six adult patients with choledochal cysts. Clinical symptoms were characterized by abdominal pain, jaundice and cholangitis. Associated hepatobiliary pathologic findings included cholelithiasis, recurrent acute pancreatitis, gallbladder carcinoma, Cystolithiasis, choledocholithiasis, biliary stricture and hepatic abscess.

Adult↗
PubMed1996

Vulvar syringoma exacerbated during pregnancy.

Although syringoma of the eyelids and the cheeks are well known and defined, vulvar syringoma is a rare clinical variant of this benign eccrine tumor. A case of syringoma of the vulva exacerbated during pregnancies with regression in the periods in between is presented. Histopathological examination showed typical features of syringomas. Only 20 patients with vulvar syringoma have been previously reported in the literature.

Female↗
PubMedDate not supplied

Cases of acute mountain sickness on Mount Agri.

Between 1983 and 1990 a total of 74 freestyle mountaineers and 88 mountaineers with skis attempted to climb Mount Agri (Ararat). From the freestyle group two mountaineers were affected by acclimatisation disorder at 3200 m and seven at 4200 m above sea level. Acute mountain sickness (AMS) affected four mountaineers at 4200 m, eight at 4700 m, two at 5000 m and two at 5165 m, while 49 reached the summit. Only one of the mountaineers with skis was affected by AMS (at 4200 m), while all the others reached the summit. The symptoms of acclimatisation disorder and AMS, according to their degree of frequency, were headache, weakness, dyspnoea and palpitation, anorexia, nausea, vomiting, giddiness, ataxia and insomnia. Pulse rates varied between 115 and 124/min, and breathing between 30 and 38/min.

Acute Disease↗
PubMedDate not supplied

Is there any relationship between pica and liver failure?

Pica is defined as the compulsive eating of anything and has been known for more than a hundred years. It is a worldwide problem which can be seen in every race, age, sex and geographic region. Its true incidence is not known and may be greater than expected. Although it is a widespread phenomenon, the causes and risk factors of pica are not well established. Clinical signs and symptoms of pica syndrome are numerous but liver disorder associated with this syndrome is not widely reported. We reported here liver disorder possibly related with pica.

Adolescent↗