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Biomedical subjects

S Yildirim

Publications and source records attributed to S Yildirim.

At least 37 records · Page 2Linked to original sources
PubMed2002

Effect of chronic renal failure on the purinergic responses of corpus cavernosal smooth muscle in rabbits.

OBJECTIVE: To examine purinergic relaxation responses in chronic renal failure (CRF) in an experimental rabbit model, and thus evaluate the possible involvement of the purinergic system in erectile dysfunction with CRF. MATERIALS AND METHODS: The relaxant effects of ATP were measured in strips of corpus cavernosum smooth muscle taken from control and CRF rabbits. CRF was induced in New Zealand white rabbits as previously described. Penises were excised from CRF rabbits 4 weeks after inducing uraemia. In an organ bath the strips from controls and CRF rabbit corpus cavernosum were pre-contracted with phenylephrine and increasing doses of adenosine and ATP added. RESULTS: In the pre-contracted rabbit cavernosal tissue the relaxations induced by adenosine and ATP were unchanged in CRF. CONCLUSION: The lack of any relaxant effect of adenosine or ATP on the relaxation of cavernosal smooth muscle in rabbits with CRF might be because the relaxant effects of these agents are endothelium-independent and the endothelial purinergic receptor density was unchanged in CRF.

Adenosine↗
PubMed2002

Bcl-2 expression in preinvasive and invasive cervical lesions.

PURPOSE: To determine the correlation between bcl-2 expression and clinicopathological findings in cervical intraepithelial neoplasias (CIN I, II, III) and invasive cervical lesions, and its effect on overall survival rate. METHODS: Fifty specimens derived from 22 preinvasive and invasive cervical cancer cases up to surgical stage IIb (21 squamous cervical carcinoma and 7 adenocarcinoma cases) were preserved in paraffin blocks from primary surgery and constituted the study group. Tissues were processed and stained by immunohistochemical methods to assess the degree of bcl-2 expression. RESULTS: Positive bcl-2 expression was detected in 54% (13/21) of invasive lesions, while negative in 46% of cases. In CIN's, overall bcl-2 positivity was detected in 68% of cases. Bcl-2 expression was highly relevant between low grade (CIN I) and high grade (CIN II-III) lesions (p < 0.05). As regards degree of tissue staining for bcl-2 in CIN III cases, a statistically relevant difference was detected in comparison with low-grade preinvasive lesions (p < 0.05). In invasive cervical cancer cases, patients with bcl-2 positivity had a longer survival rate. By using the Cox regression model, univariate analysis did not show any specific prognostic factor to be important for survival rate, whereas, on multivariate analysis, histopathologic subtypes (p = 0.0390) and stage of tumor (p = 0.0451) had a statistically significant impact on overall survival rate. CONCLUSIONS: Bcl-2 expression, especially in preinvasive lesions, may play a role in the apoptotic process and be regarded as a marker for disease progression. In invasive cervical carcinomas, bcl-2 expression has not been shown to be effective in overall survival rates.

Adenocarcinoma↗
PubMed2002

Hyperbaric oxygen improves healing in experimental rat colitis.

This study was designed to investigate therapeutic effects of hyperbaric oxygen on experimentally induced colitis in rats by assessing oxidative tissue damage, neutrophil accumulation and histological changes. Six groups of animals were used. No procedures were done in the sham group. In the vehicle group, 50% ethanol-induced colitis, and in four other groups, 2,4,6-trinitrobenzene sulphonic acid-induced colonic inflammation was achieved. In acute and chronic colitis non-treatment groups, no other procedure was done. In acute and chronic colitis hyperbaric oxygen treatment groups, rats underwent hyperbaric oxygen treatment for two or fourteen days. On the third and fifteenth days respectively tissue and blood samples were taken for microscopic and macroscopic damage assessment, myeloperoxidase activity and serum carbonyl content measurements. There was significant colonic tissue damage in non-treatment groups at 48 hours and 14 days. Hyperbaric oxygen treatment ameliorated the macroscopic damage significantly in chronic colitis. Amelioration of microscopic changes was not significant in each hyperbaric oxygen-treated group. Hyperbaric oxygen treatment significantly reduced tissue myeloperoxidase activity in acute colitis and decreased plasma carbonyl content in chronic colitis. In the present study, hyperbaric oxygen treatment significantly ameliorated trinitrobenzene sulphonic acid-induced chronic colitis in rats.

Analysis of Variance↗
PubMed2001

Inhibitor effect of omeprazole in isolated human myometrial smooth muscle.

The aim of the present study was to investigate the effect of omeprazole, an H+-K+-ATPase inhibitor, in myometrial smooth muscle strips from women undergoing elective caesarean section at term. Isolated myometrial strips taken with informed consent were obtained from eight pregnant women undergoing elective caesarean section at term (not in labour) and mounted in organ baths for recording of isometric tension. We recorded the effect of increasing concentrations of omeprazole on spontaneous and Ca2+-induced contractions of myometrial smooth muscle and on contractions of myometrial smooth muscle pretreated with indomethacin (3 x 10(-6) M) and L-NAME (3 x 10(-5) M). Omeprazole (10(-4)-10(-3) M) decreased the amplitude and frequency of spontaneous contractions in a time- and concentration-dependent manner in all myometrial smooth muscle isolated from pregnant women. The decrease in amplitude of contractions in myometrial smooth muscle reached statistical significance beginning from the concentration of 3 x 10(-4) M. Addition of indomethacin (3 x 10(-6) M) and L-NAME (3 x 10(-5) M) in to the organ baths 30 min before did not change relaxation responses to omeprazole. When 8 mM Ca2+-precontracted in Ca2+-free medium myometrial smooth muscle were exposed to increasing concentrations of omeprazole (10(-5)-10(-3) M), omeprazole produced relaxation responses in a time- and concentration-dependent manner, reaching statistical significance at 10(-4) M. These results show: (1) omeprazole time- and concentration-dependently decreased spontaneous contractile activity in myometrial smooth muscle isolated from pregnant women, (2) omeprazole-induced relaxations was not influenced by indomethacin and N(G)-nitro-L-arginine methyl ester (L-NAME), suggesting that it is not mediated by cyclooxygenase products and nitric oxide, and (3) omeprazole brought about time- and concentration-dependently relaxation of myometrial smooth muscle precontracted by 8 mM Ca2+ in Ca2+-free medium. This effect of omeprazole may be due to blockade of the calcium channels.

Calcium↗
PubMed2001

Relaxant effects of some benzothiazolinone derivatives on isolated rabbit corpus cavernosum.

In the present study, two 6-(fluorobenzoyl)-3-piperazinomethyl-2-benzothiazolinone derivatives were synthesized and their relaxant effects on isolated rabbit corpus cavernosum investigated. Compounds Y-16 and Y-21 can alter the ability of corpus cavernosum smooth muscle to contract. Strips of rabbit corpus cavernosum smooth muscle were mounted in isolated tissue baths for measurement of isometric contractile force. Compounds (10(-6) - 10(-3) M) did not cause contraction but induced relaxation in precontracted corpus cavernosum smooth muscle. Neither N-nitro-L-arginine methylester (L-NAME) nor indomethacin affected the relaxant effect of these compounds. Glibenclamide and tetraethylammonium chloride (TEA) also did not influence the relaxation induced by the compounds. In conclusion, in isolated rabbit corpus cavenosum, Y16 and Y21 have a relaxant potency equal or superior to known vasoactive agents. Further investigations are needed to show the importance of these effects for the diagnosis and treatment of erectile dysfunction.

Animals↗
PubMed2001

Effects of the specific phosphodiesterase inhibitors on alloxan-induced diabetic rabbit cavernous tissue in vitro.

An experimental study was done to examine a potential role of phosphodiesterase (PDE) inhibitors in the treatment of diabetic erectile dysfunction. Relaxant effect of specific PDE inhibitors were measured in strips of corpus cavernosum smooth muscle taken from control and diabetic groups. Diabetes mellitus was induced in New Zealand white rabbits using alloxan. Penises excised from diabetic rabbits 8 weeks after the induction of diabetes mellitus. In the organ bath strips from control and diabetic rabbit corpus cavernosum were precontracted and increasing doses of several PDE inhibitors were added. In the precontracted rabbit cavernous tissue, sulmazole and zaprinast specific PDE V inhibitors were equally potent and efficacious in vitro but amrinone, a specific PDE III inhibitor, exhibits low relaxant effects. All PDE inhibitors tested showed a similar relaxation effect on corpus cavernosum smooth muscle from control and 8-week diabetic rabbits. The present study provides the possibility of using selective PDE III and V inhibitors in the treatment of diabetic impotence.

Amrinone↗
PubMed2001

The effect of Helicobacter pylori eradication on gastric juice and blood ammonia concentrations and on visual evoked potentials in cirrhotics.

BACKGROUND: The primary source of ammonia is the gut. Ammonia can also be generated by the urease activity of Helicobacter pylori in the gastric mucosa. The aim of this study was to investigate the effect of H. pylori eradication on blood and gastric juice ammonia levels and on visual evoked potential (VEP) recordings in cirrhotic patients. MATERIALS AND METHODS: Male patients with cirrhosis and H. pylori infection were prospectively evaluated. All patients were given triple regimen for eradication for 10 days. Gastroscopy together with gastric juice sampling for ammonia and mucosal sampling for H. pylori status was performed before and after therapy. Gastric juice and blood ammonia levels were measured and VEP recordings were obtained before and after treatment. RESULTS: Twenty-seven patients were included in the study. Patients with overt clinical hepatic encephalopathy were excluded from the study. Twenty-four out of twenty-seven patients became H. pylori-negative after the treatment. Ammonia measurements and VEP recordings were evaluated in the 24 patients in whom eradication was successful. A slight but statistically significant decrease in blood and a considerable decrease in gastric juice ammonia levels were observed after treatment [from 44.23 micromol/l to 41.6 micromol/l compared with 3234 micromol/l to 2709 micromol/l, respectively (p <.05)] in patients in whom H. pylori was eradicated. VEP recordings were abnormal in 14 out of 24 patients before the treatment. Only four of these 14 patients with abnormal recordings showed improvement. (p > .05). CONCLUSIONS: Helicobacter pylori eradication in cirrhotics decreases blood and gastric juice ammonia concentrations whereas it does not provide an improvement in VEP recordings.

Ammonia↗
PubMed2001

Relaxation induced by omeprazole does not change in diabetic rabbit corpus cavernosum.

OBJECTIVE: To investigate the changes in relaxation responses to omeprazole in corpus cavernosal strips from rabbits with diabetes induced by alloxan. MATERIALS AND METHODS: Diabetes was induced in 10 New Zealand white rabbits. After 8 weeks, the reactivity to electrical-field stimulation, carbachol and omeprazole of corporal strips from the penises of the diabetic animals and from 10 untreated controls was assessed in organ chambers. RESULTS: In the diabetic group, the relaxation responses of corpus cavernosal strips to omeprazole were comparable with those of the control group, whereas the relaxation responses to electrical field stimulation and carbachol were impaired. CONCLUSION: The relaxant effect of omeprazole in corpus cavernosum was not affected by diabetes, in which neurogenic and endothelium-mediated relaxations were impaired.

Animals↗
PubMed2001

CagA status in dyspeptic patients with and without peptic ulcer disease in Turkey: association with histopathologic findings.

BACKGROUND: CagA seropositivity is closely associated with that of vacuolating cytotoxin (VacA). Helicobacter pylori strains positive for both VacA and CagA were reported to be strongly associated with peptic ulcer disease. Different results reporting that cagA gene is not associated with more serious diseases, lowers the importance of CagA protein as a marker. In this study, CagA seropositivity is examined in Turkish peptic ulcer and nonulcer dyspepsia patients; histopathologic scores of CagA (+) and CagA (-) groups were compared. MATERIALS AND METHODS: Sixty consecutive patients (one gastric ulcer, 13 duodenal ulcer and 46 nonulcer dyspepsia) (mean age 40.9 +/- 14.7; 33 women, 27 men) with dyspeptic complaints who underwent upper gastrointestinal (GI) endoscopy were included. Biopsies from the antrum and corpus were used for histopathologic examination and for rapid urease test. H. pylori-negative patients comprised the control group. Histopathologic findings were graded using a previously described grading system (for inflammation, activity, atrophy, intestinal metaplasia and H. pylori, grades from 0 to 3 were used to quantify the findings). In H. pylori-positive patients, antibodies against CagA protein were determined using an ELISA METHOD: RESULTS: H. pylori was (+) in 46 patients. One duodenal ulcer and 13 nonulcer dyspepsia patients were negative for H. pylori. CagA positivity is significantly higher in peptic ulcer patients [12/12] than in nonulcer dyspepsia patients [25/33]. While inflammation, activity and atrophy scores were significantly higher in CagA positive patients, intestinal metaplasia and H. pylori load scores were not. Although the histopathologic scores in controls were lower than CagA (-) group, statistical significance was observed only in inflammation and intestinal metaplasia scores. CONCLUSION: Development of more prominent gastritis and severe atrophy in CagA (+) patients is an indicator of the importance of CagA rather than H. pylori load. Therefore, we suggest that nonulcer dyspepsia patients should also be tested for CagA status along with the tests for H. pylori status; and a positive CagA testing should be considered as an indication for eradication treatment. If CagA is negative, further assesment should be performed to decide whether or not to treat the patient.

Adult↗
PubMed2001

De novo malignant eccrine spiradenoma with an interesting and unusual location.

BACKGROUND: Reports in the literature reveal that malignant eccrine spiradenomas (MES) are exceedingly rare, and represent aggressive tumors arising in long-standing benign eccrine spiradenomas (ES). OBJECTIVE: We present a de novo case of MES of the nose, in contrast to reports in the literature of progression from long-standing benign lesions. METHODS: Case report and brief review of the literature. RESULTS: Our case was accepted as de novo MES because there was no evidence of ES on pathologic examination. It was treated by surgical excision with 1 cm tumor-free margins. No recurrence or complications were observed for 2 months, but long-term follow-up could not be performed because the patient died of adenocarcinoma of the colon. CONCLUSION: Although previously reported lesions have arisen in long-standing benign ESs, usually on the trunk or extremities, this report shows that MES may occur as a primary malignant tumor and may occur in unusual locations such as the nose.

Adenocarcinoma↗
PubMed2001

The use of combined nasolabial V-Y advancement and glabellar flaps for large medial canthal defects.

BACKGROUND: Reconstruction of the medial canthal area presents many challenges for surgeons. It has many functional and cosmetic peculiarities. The combined use of glabellar and nasolabial V-Y advancement flaps is an effective method for repairing large medial canthal defects. OBJECTIVE: To describe and illustrate a technique to repair medial canthal defects. METHODS: Our experience with combined usage of nasolabial V-Y flap and glabellar flaps for medial canthal closure after tumor resection in 23 patients is reported. RESULTS: All resections and reconstructive procedures were performed under local anesthesia. All patients were treated without any complications such as flap loss, wound dehiscence, lymphedema, or ectropion. Fine results were achieved from both the functional and aesthetic point of view. CONCLUSION: This combination has many advantages over skin grafts and other local flaps. It is easy to design, reliable, and offers good cosmetic results. This combination is recommended to plastic surgeons as a safe and effective procedure for reconstruction of medial the canthal area.

Basal Cell Carcinoma↗
PubMed2001

Nasolabial V-Y advancement for closure of the midface defects.

BACKGROUND: V-Y subcutaneous advancement flaps receive an excellent blood supply from subcutaneous tissue and are ideal for use on the face. Also it is advantageous cosmetically compared to other local flaps. OBJECTIVE: Nasolabial V-Y advancement flaps are very useful in closing defects of the midface region after tumor resection. METHODS: Our experience with nasolabial V-Y flaps in 22 patients is reported. The average defect size was 2.4 cm x 3.2 cm. RESULTS: Minor flap necrosis occurred in one patient and simple lower eyelid ectropion in another. CONCLUSION: Nasolabial V-Y advancement flap is a simple and satisfactory alternative for closing relatively large defects in the midface when compared with other methods such as skin graft and rotation or transposition flaps. It is easy to design, reliable, and offers good cosmetic results.

Aged↗
PubMed2001

The activities of carbonic anhydrase and alkaline phosphatase in ancient human bones. Purification and characterization of outer peripheral, cytosolic, inner peripheral, and integral CA.

In the present study, bone carbonic anhydrase was isolated from ancient human bones and its characteristic features were determined. For this purpose, the skull bone of about 3000 years age was used. The purification was performed in four steps. Four different isoenzymes of CA, including outer peripheral, inner peripheral, integral, and cytosolic were purified and characterized. Affinity chromatography using Sepharose-4B-L-tyrosyn sulfanilamide as a support material was used in its purification. Two different methods were used for enzymatic activity determination: a) hydratase, and b) esterase methods. Bradford and Coomassie Brillant Blue methods were used for protein determination. Optimal pH, temperature, and molecular weight determinations were performed by conventional methods. The purification degree and the subunits, if present, were determined by SDS-PAGE. The effects of some chemicals on the enzyme were also investigated. The most cardinal finding was that the enzymatic activity has been found in antique human bone, showing some other enzymatic activity. That the alkaline phosphatase activity has been determined in the same sample supports the finding of carbonic anhydrase.

Alkaline Phosphatase↗
PubMed2001

Hydatid cyst in the soft tissue of the face without any primary.

Hydatid cyst of the subcutaneous tissue is rare, and often presents as a simple soft-tissue mass. A case of primary subcutaneous hydatid disease arising in the malar region is reported. Histopathological examination revealed the characteristic findings, which are consistent with soft-tissue hydatid disease. There was no sign of echinococcal involvement of organs other than the soft tissue of the face. To the authors' knowledge, this is the first reported case of a primary subcutaneous hydatid cyst arising in the skin in the absence of internal involvement. The patient remains disease free 14 months after surgery. The authors present their clinical findings, diagnostic techniques, and treatment of the patient, and review the literature.

Adult↗