PubMed Health⌕ Search

Biomedical subjects

I Koçak

Publications and source records attributed to I Koçak.

At least 19 recordsLinked to original sources
PubMed2006

Retrobulbar blood flow in patients with cataract.

OBJECTIVE: To investigate retrobulbar haemodynamics in patients with cataract. SUBJECTS AND METHODS: Colour Doppler imaging of the ophthalmic artery was carried out on the eye scheduled for surgery in 30 patients with cataract and in one randomly selected eye of 100 healthy controls. The peak systolic velocity, mean velocity, end diastolic velocity and resistivity index in the ophthalmic artery were computed and adjusted for the influence of age and mean arterial pressure. Cataract type was recorded and lens opacity was measured with an opacity lensmeter. Odds ratio (OR) for cataract was analysed in a logistic regression model, depending on the adjusted blood-flow parameters, age and smoking status. RESULTS: The mean (SD) age was 45.5 (17.7) and 67.6 (5.8) years in controls and patients with cataract, respectively (p<0.001). The female to male ratio was 54:46 and 13:17, respectively (p = 0.41). Significant predictors of cataract in a forward stepwise logistic regression analysis were age (OR = 1.194; 95% confidence interval (CI) = 1.103 to 1.292; p<0.001), smoking status (OR = 14.119; 95% CI = 2.753 to 72.398; p = 0.002) and mean blood-flow velocity in the ophthalmic artery (OR = 0.731; 95% CI = 0.607 to 0.881; p = 0.001). Adjusted mean velocity was significantly lower in patients with cataract, even when only age-matched (age >55 years) non-smokers (31 controls, 19 patients with cataract) were considered (p = 0.003). Lens opacity and the type of cataract had no influence on the present findings. CONCLUSION: High mean velocity in the ophthalmic artery may be associated with a reduced risk of cataract.

Adult↗
PubMed2005

Effects of sildenafil on blue-on-yellow and white-on-white Humphrey perimetry in 3 months regular use.

PURPOSE: To assess the effects of sildenafil on blue-on-yellow (B/Y) and white-on-white (W/W) Humphrey perimetry in a group of men with erectile dysfunction in 3 months regular use. METHODS: In this prospective study, 14 patients with erectile dysfunction received 50 mg doses of sildenafil (Viagra, Pfizer) two times per week regularly for 3 months. Patients underwent best-corrected visual acuity (BCVA), colour vision, anterior segment and fundus examination, and B/Y and W/W Humphrey perimetry in each eye before and after sildenafil treatment. Changes in mean deviations (MD) were compared separately for both eyes. RESULTS: No significant changes from baseline were observed in BCVA and colour vision after sildenafil treatment. The anterior segment and fundus examinations revealed no abnormalities. There was no change on B/Y and W/W Humphrey visual field. MD values of B/Y and W/W Humphrey perimetry remained nonsignificant for both eyes after 3 months regular use of sildenafil (P=0.133, and 0.092, respectively, for right, and P=0.221 and 0.925, respectively, for left eyes). CONCLUSION: Oral sildenafil used regularly for 3 months produced no effect on B/Y and W/W Humphrey perimetry.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2002

Pro-inflammatory cytokine response of the fluid contents of spermatoceles and epididymal cysts.

The aim of the study was to determine the cellular contents and concentrations of interleukin 6 (IL-6), interleukin 8 (IL-8) and tumour necrosis factor alpha (TNF-alpha) in fluids of patients with spermatocele or epididymal cyst. Twenty-five symptomatic patients, 14 with epididymal cysts and 11 with spermatoceles, were included in the study. Fluids were obtained during surgical excision of the cysts and cytological smears were stained with May-Gruenwald-Giemsa to establish cell components. The concentrations of IL-6, IL-8 and TNF-alpha were measured by chemiluminescent immunometric assay. Cytological analysis of the fluids demonstrated various sperm forms ranging from immature germ cells to degenerated spermatozoa without inflammatory cells such as neutrophils and macrophages. The concentrations (mean+/- SEM, pg/mg protein) of IL-6, IL-8 and TNF-alpha were 13.52 +/- 1.40, 22.20 +/- 2.43, 3.51 +/- 1.43 in spermatocele fluids and 5.76 +/- 0.48, 11.57 +/- 1.89, 2.53 +/- 0.41 in epididymal cyst fluids. Both IL-6 and IL-8 concentrations in the spermatocele group were higher than in the epididymal cyst group (P < 0.0001). There were no differences in TNF-alpha concentrations between the groups (P > 0.05). These findings indicate that local production of pro-inflammatory cytokines is involved in cyst formation. The presence of immunologic activation in these fluids advocates a policy of selective surgical intervention in patients with spermatocele or epididymal cyst.

Adult↗
PubMed2002

Changes in urethral connective tissue after estrogen replacement therapy in ovariectomized rats.

OBJECTIVE: Genuine stress urinary incontinence is a common problem after the middle age. Various treatment modalities have been tried as a treatment for this entity and estrogens are one of the most common alternatives. Their effects on the urethral mucosa have been described in many studies, while the impact on the urethral connective tissue has been evaluated only in a few reports. In this study, we aimed to investigate the effect of estrogen on urethral connective tissue in ovariectomized rats. MATERIAL AND METHODS: Thirty-six Wistar rats (4 months old, 250-300 g weight) were included in the study. They were organized as group 1 (ovariectomized, n = 10), group 2 (ovariectomized + late estrogen treatment, n = 10), group 3 (ovariectomized + early estrogen treatment, n = 10) and group 4 (sham operated, n = 6). Rats in group 1 were killed 6 weeks after the ovariectomy. Group 2 was ovariectomized 6 weeks before treatment and then received estradiol for 6 weeks. Group 3 was treated with estradiol for 6 weeks immediately after the ovariectomy. After killing the rats, urethral tissues were removed. Quantitative analysis of collagen fiber content was done by computerized image analyzer system in specimens stained with Masson's trichrome technique. RESULTS: Percentages of collagen fiber content (mean +/- standard error of mean) were 58.4 +/- 5.9% in group 1; 53.3 +/- 4.8% in group 2; 46.3 +/- 3.4% in group 3 and 40.2 +/- 3.2% in group 4. There was not any significant difference among the groups (p > 0.05). CONCLUSIONS: Our results suggest that early and late estrogen replacements do not seem to have a discriminating effect on the urethral connective tissue. Further studies are needed to assess the preventive effect of estrogen on urethra.

Animals↗
PubMed2001

A new experimental model for cryptorchidism: inguinoscrotal approach.

We investigated the effect of inguinal canal closure as a new mechanically induced cryptorchid rat model. The effectiveness of this new model was evaluated by histopathological examination. Thirty-one 21-day-old Wistar rats were divided into four groups. In groups 1 (n = 6), 2 (n = 6) and 3 (n = 7), unilateral undescended testis was created by performing inguinal canal closure with inguinoscrotal approach. Sham-operated rats were used as controls in group 4 (n = 12). The rats were killed on day 30 after surgery in group 1, day 45 in group 2 and day 60 in group 3. The seminiferous tubular diameter, number of tubules with mature germ cell and Leydig cell clusters were evaluated. None of the rats were lost during the study period. Signs of infection were not detected in operation site although antibiotics were not used. Overall only three (16%) testes descended into scrotum in study groups. The operation time was 3-4 min for each rat. Histopathological examination revealed detrimental effects of cryptorchidism on testicular growth in study groups. In all groups, except the sham group, the mean tubular diameter and the number of tubules with mature germ cells in the left testicle were significantly decreased compared to the right ones. Our findings were in correlation with other experimental studies using different rat models of cryptorchidism. This new model of cryptorchidism is considered to provide a simple and effective technique for investigating the impaired development of the testes in cryptorchidism.

Animals↗
PubMed2001

The effect of estrogen-replacement therapy on clitoral-cavernosal tissue in oophorectomized rats: a histo-quantitative study by image analyzer.

Sexual dysfunction is an important problem for aging females. However, little attention has been paid to female sexual dysfunction. The clitoris is an important organ for physiological sexual function in females. There is a close relationship between the presence of sexual complaints and levels of estrogen. Using the rat as an experimental model, we evaluated the effect of estrogen-replacement therapy and its timing on clitoral-cavernosal collogen fiber content after oophorectomy. Four-month-old female Wistar rats (n = 36) weighing 230-250 g were used. They were categorized into four groups: oophorectomized (Group 1: n = 10); oophorectomized delayed estrogen replacement (group 2: n = 10); oophorectomized + immediate estrogen replacement (group 3: n = 10); and sham operated (group 4: n = 6). The estrogen replacement used was 17-beta-estradiol. All rats were euthanized at the same age. The specimens were stained with Masson's trichome technique, and computerized image analysis was used to quantify the collagen-fiber content of clitoral-cavernous tissue. The clitoral collagen-fiber percentages in the different groups were as follows: group 1: 64.17 +/- 5.01%; group 2: 62.57 +/- 5.37%; group 3: 56.33 +/- 3.85%; group 4: 51.48 +/- 6.37%, respectively. Although there was a tendency in the untreated group for a higher collagen-fiber content, no statistically significant difference was found among groups (P > 0.05). Although the results of this study were not statistically significant, estrogen did appear to decrease clitoral-cavernosal collagen-fiber content. These findings may be important in the pathophysiology of postmenopausal female sexual dysfunction.

Animals↗
PubMed2001

Subclinical chorioamnionitis as an etiologic factor in preterm deliveries.

OBJECTIVE: This study was performed to determine the possible relationship between histologic chorioamnionitis and genital tract cultures and their contribution to preterm delivery. METHODS: The study group consisted of 45 preterm and 37 term pregnancies. Cervico-vaginal cultures were obtained from all patients at admission and placentas were histopathologically evaluated and graded for inflammation of the chorial plate, amniochorionic membrane, umbilical cord and villi. Inflammation scores and presence of pathogenic bacteria were compared between the preterm and term patients. RESULTS: Severe chorionic plate inflammation was present in 35.5% of 45 preterm deliveries as compared to 5.4% of 37 term deliveries. Amniochorionic-decidual inflammation was not present in 14 of the term deliveries (38%), mild (Grade 1--2) in 20 (54%) and severe (Grade 3--4) in 3 (8%) as compared to 14 (31%), 17 (38%), and 14 (31%) in the preterm group, respectively (P<0.05). Pathogenic bacteria were isolated from the lower genital tracts of all patients who had severe chorionic plate (CP) and/or chorioamnionic (CA) inflammation while this was true only in 37.5% of the patients with no or only mild chorionic plate inflammation (P<0.001 for CP, P<0.01 for CA). CONCLUSION: Our results show that pathogenic bacterial colonisation of the cervicovaginal region is closely associated with placental inflammation, preterm labor and cervico-vaginal cultures which may be useful in determining the pregnancies at risk for preterm labor.

Adult↗
PubMed2001

Evaluation of side effects of sildenafil in group of young healthy volunteers.

We evaluated the safety and side effects of sildenafil in a group of sexually active volunteers younger than 40 years under conditions without sexual stimulation. Single oral dose of 50 mg dildenafil (n = 20) or placebo (n = 20) was randomly administered to 40 sexually active volunteers with the mean age of 26.80 +/- 5.29 in sildenafil group and 25.70 +/- 4.95 in placebo group. All the subjects were informed about the study, but not about the medicine. The following tests were performed immediately before and 90 minutes after the administration of the medicine: resting heart rate, blood pressure, electrocardiogram, visual acuity, color vision. The subjects were also asked to describe any discomfort or difference. Mann Whitney U test was used for statistical analyses. The only statistically significant difference was between heart rates before and after the administration of the sildenafil (p = 0.02). Color vision, visual acuity tests yielded no differences. The decrease in blood pressure was not significant. The most common side effects were flushing (75% and 0%), headache (50% and 5%), dyspepsia (15% and 5%), unintentional incomplete sexual arousal (15% and 0%) and palpitation (15% and 10%) in groups of sildenafil and placebo, respectively. The only serious side effect requiring medical treatment was arthralgia on the knee in one subject. Although these side effects can be acceptable, the likelihood of these side effects needs to be made clear to potential users of this medication.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2001

Effect of sildenafil on ocular haemodynamics.

PURPOSE: To study the effect of sildenafil, which is an effective agent for the treatment of erectile dysfunction, on ocular haemodynamics. METHODS: In this prospective study we examined the effect of a single oral dose of 50 mg sildenafil (Viagra) in a group of healthy young male volunteers, by using colour Doppler ultrasound imaging to measure haemodynamic variables in the central retinal artery (CRA), short temporal posterior ciliary artery (STPCA) and ophthalmic artery (OA). The following examinations were performed on both eyes immediately before and 1 h after a single oral dose of 50 mg sildenafil: visual acuity, intraocular pressure (IOP), colour vision, anterior segment, fundus appearance, resting heart rate, blood pressure and colour Doppler measurements. RESULTS: After sildenafil administration, peak systolic velocity, mean velocity and end-diastolic velocity significantly increased in the OA of both eyes. All Dopper indices remained non-significant for the CRA and STPCA of both eyes. Sildenafil did not cause any significant change in IOP, colour vision, visual acuity, systolic blood pressure or diastolic blood pressure. However, heart rate measurements increased significantly after sildenafil administration compared with baseline (p = 0.003). CONCLUSION: The increased flow velocity in the ophthalmic artery seems to be due to a vasodilator effect of sildenafil.

Adult↗
PubMed2001

Treatment of chronic anovulation resistant to clomiphene citrate (CC) by using gonadotrophin-releasing hormone agonist (GnRH-a) ovarian suppression followed by recombinant follicle-stimulating hormone (r-hFSH) treatment (Suprecur, Puregon).

We performed a prospective study to assess the effects of a starting dose of 50 units of recombinant follicle stimulating hormone (Puregon) during gonadotrophin-releasing hormone agonist therapy (Suprecur) on follicular development in patients with clomiphene citrate-resistant polycystic ovary syndrome (PCOS). In a prospective clinical trial, 25 women with clomiphene citrate-resistant PCOS who wanted to become pregnant were treated by a low-dose step-up protocol of SC recombinant follicle stimulating hormone administration during gonadotrophin-releasing hormone agonist therapy, monitored by transvaginal ultrasonography and retrospectively by serum endocrine assays taken at each monitoring visit. Cancellation of cycles, ovulation, rate and size of follicles growth, serum E2 concentration and pregnancy were recorded. All patients exhibited a response: 22 patients ovulated, of whom 10 conceived. Using the low-dose protocol during gonadotrophin-releasing hormone agonist therapy permitted induction of ovulation safely and successfully in patients with clomiphene citrate-resistant PCOS who were patients previously difficult to treat with the conventional ovulation induction protocol.

Journal Article↗
PubMed2001

Liposarcoma of the spermatic cord.

A 64-year-old male presented with a 4-year history of a mass in the left scrotum. Radical orchiectomy was performed. Pathological analysis demonstrated a well-differentiated liposarcoma. No evidence of recurrence or metastasis has been noted during the 3-month follow-up without any postoperative adjuvant therapy.

Genital Neoplasms, Male↗
PubMed2001

Serum nitric oxide and glutathione levels in preeclamptic and normotensive women during labor.

This study was performed on 38 preeclamptic women, including 26 severely preeclamptic and eclamptic cases, as well as 50 normotensive pregnant controls. Twenty cases in the preeclamptic group and 34 cases in the control group were in labor. Serum nitric oxide levels were measured as total nitrites after reduction of nitrates to nitrites. Among the control subjects, nitric oxide levels were significantly lower in the cases in labor when compared to those not in labor (p < 0.05), but glutathione levels were not significantly different (p >0.05). Among the preeclamptic patients, although nitric oxide levels were not significantly different between the cases in and not in labor (p > 0.05), glutathione levels were significantly higher in the latter group (p < 0.05). Thus, in preeclamptic patients there might be a compensatory increase in nitric oxide production during labor in order to maintain the systemic circulation. Glutathione levels might also be increased to compensate for the marked oxidative stress.

Adult↗
PubMed2000

Effect of hypothyroidism on the testes in mature rats and treatment with levothyroxine and zinc.

This study was performed to investigate the effect of propylthiouracil (PTU) on rat testis, and to compare the results of the different treatment regimens of levothyroxine and zinc. Twenty sexually mature Wistar albino rats were subjected to PTU for 14 days intraperitoneally to make them hypothyroidic. The effect of PTU on testicular function was assessed histopathologically after unilateral orchiectomy on day 15, and treatment was evaluated by measuring serum thyroid-stimulating hormone (TSH), T3, T4, and zinc levels on days 0, 7, and 15. The rats were then divided into five groups which were given levothyroxine and/or zinc treatment for 15 days. Orchiectomies were repeated on day 30, and specimens were evaluated histopathologically. Although serum T3, T4 and zinc levels decreased, serum TSH levels increased in PTU-treated rats, and the difference to the control group was statistically significant (P < 0.001). Maturation arrest of spermatogenesis, a reduced number of Sertoli and Leydig cells, a decreased tubular diameter, interstitial oedema, and thickening of basal membrane were observed in hypothyroidic testicles. After treatment, testicular histology and spermatogenesis gradually recovered in all groups with hypothyroidism, but maximum improvement was achieved in the levothyroxine + zinc sulphate replacement group, indicating a possible role of zinc in testicular function.

Animals↗
PubMed2000

Effects of Seprafilm (sodium hyaluranate-based bioresorbable), Sepracoat (0.4% hyaluronic acid), and Ringer's lactate on the prevention of postsurgical adhesion formation in rat models.

Forty adult female rats were randomly divided into four groups. Before the standard surgical procedure which consisted of creating a lesion with a lancet over the right uterine horn. Group I received no medication. Ringer's lactate (RL) solution was applied intraperitoneally to Group II at the end of the surgery. Sepracoat solution was applied intraperitoneally to Group III at the onset of the surgery. Group IV randomly received Seprafilm wrapped over the entire right uterine horn. Re-laparotomy was performed 3 weeks later to evaluate the adhesions. The mean adhesion scores were (mean+/-SD) 2.90+/-0.18, 1.00+/-0.36, 0.50+/-0.17 and 0.40+/-0.16 in Groups I, II, III, IV, respectively. The postsurgical adhesions were significantly less in the groups treated with Seprafilm and Sepracoat.

Journal Article↗
PubMed1999

Reduction of adhesion formation with cross-linked hyaluronic acid after peritoneal surgery in rats.

OBJECTIVE: To examine the effectiveness of a cross-linked hyaluronan solution (auto-cross-linked polysaccharide [ACP] gel) for the prevention of postsurgical adhesions. DESIGN: A randomized blinded study using a rat model of laparotomy. SETTING: Surgical Research Laboratory in a university medical school. ANIMAL(S): Sixty-seven sexually mature rats. INTERVENTION(S): Standardized surgical trauma was induced in the rat uterine horn to induce adhesion formation. After trauma, group-1 animals (n = 23) received no treatment, group 2 (n = 21) received noncross-linked hyaluronic acid (HA), and group 3 (n = 23) received cross-linked HA applied on the lesion. MAIN OUTCOME MEASURE(S): Six weeks after laparotomy, repeat laparotomy was performed and the adhesions were scored according to Blauer's scoring system. RESULT(S): Overall, 84% of the untreated animals and 65% of the animals treated with noncross-linked HA presented with severe adhesions. The mean (+/-SEM) increase in the adhesion score was 2.46+/-0.23 in the untreated group, 2.23+/-0.29 in the group receiving noncross-linked HA, and 1.27+/-0.12 in the ACP gel group. CONCLUSION(S): ACP gel holds promise as a novel resorbable biomaterial for the reduction of postoperative adhesions after laparotomy.

Animals↗
PubMed1999

Helicobacter pylori seropositivity in patients with hyperemesis gravidarum.

OBJECTIVE: The aim of this study was to analyze the hypothesis that there was an association between hyperemesis gravidarum (HG) and Helicobacter pylori (HP) infection. METHODS: The study group consisted of 95 pregnant women with HG and 116 asymptomatic pregnant women who were admitted to our hospital between January 1997 and October 1998. Specific serum immunoglobulin G for HP was assayed in the sera of the study group after informed consent was obtained. Chi-square and Student's t-test were used accordingly for statistical analysis of the data. RESULTS: Serologically positive HP infection was detected in 87 of the 95 patients with HG (91.5%) whereas 52 of the 116 asymptomatic gravidas (44.8%) serving as the control group had positive antibody concentrations against HP. The ratio of HP positivity in pregnant women with HG was significantly higher than asymptomatic pregnant women (P < 0.001). The mean index percentages of IgG titers were 73.8 +/- 9.7% in the hyperemesis gravidarum and 25.8 +/- 5.6% control group (P < 0.01). CONCLUSION: HP infection seemed to be significantly associated with hyperemesis gravidarum in our pregnant patient population with hyperemesis gravidarum.

Adult↗