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Biomedical subjects

S Coskun

Publications and source records attributed to S Coskun.

At least 19 recordsLinked to original sources
PubMed2005

Plasma transglutaminase factor XIII induces microvessel ingrowth into biodegradable hydroxyapatite implants in rats.

Coagulation factor XIII is a member of the transglutaminase-family. Transgluaminases cross-link either fibrin monomers in blood coagulation or extracellular proteins in extracellular matrix formation. In early stages of bone healing migration and proliferation of endothelial cells lead to formation of new vessels. The aim of this study was to investigate the angiogenetic activity of plasma factor XIII in bone defects filled with nanoparticulate hydroxyapatite paste. A critical size defect was created in the tibial head of rats which was not filled in group I. In group II the defect was filled with hydroxyapatite paste, and in group III with hydroxyapatite paste enriched with factor XIII. Ten days after surgery angiogenesis in the defects was assessed using immunohistochemistry and confocal laser scanning microscopy. Ac16 antibody was used to detect activation of factor XIII into factor XIIIA. In defects without biomaterial (group I) vessel-rich connective tissue and diffuse distribution of capillaries was observed. In defects filled with pure hydroxyapatite (group II) formation of capillaries was limited to the host bone-hydroxyapatite interface. In contrast, addition of plasma factor XIII to hydroxyapatite (group III) stimulated formation of vessels within the biomaterial. The current study reveals that factor XIII can improve angiogenesis in hydroxyapatite.

Absorbable Implants↗
PubMed2005

Lipid peroxides in obese patients and effects of weight loss with orlistat on lipid peroxides levels.

OBJECTIVE: Obesity is a well-known risk factor of atherosclerosis. Recent studies showed that obesity is associated with enhanced lipid peroxidation. The aim of this study is to investigate the effect of weight reduction with orlistat treatment on lipid peroxidation levels. We assessed lipid peroxidation by measuring the concentration of plasma malondialdehyde (MDA). DESIGN: A randomized, controlled, open-label 6-month study. SUBJECTS: In total, 36 obese (body mass index (BMI) >30 kg/m2) and 11 healthy age-matched control subjects were enrolled in the study. MEASUREMENTS: Fasting glucose, triglyceride, total cholesterol, HDL cholesterol and LDL cholesterol and MDA levels were measured in both groups. Obese subjects received orlistat, 120 mg three times daily together with hypocaloric diet. After 6 months of treatment laboratory tests were repeated. RESULTS: MDA levels were significantly higher in obese patients than the control group (P<0.0001). After 6 months of treatment in obese subjects, the mean weight of the patients decreased by 6.8 kg, the BMI by 3.2 kg/m2. Plasma MDA levels were significantly reduced by weight loss from 2+/-0.77 to 0.89+/-0.41 nmol/ml (P<0.001). BMI correlated with MDA levels at baseline (r=0.6, P<0.0001). Changes in BMI was positively associated with plasma MDA level reduction (r=0.36, P<0.05). CONCLUSION: These results indicate that obesity is associated with increases in endogenous lipid peroxides. Our data show that the indicator of lipid peroxidation-MDA-falls markedly in association with weight loss with orlistat. The demonstration of decreased free radical generation has important implications for oxidative mechanism underlying obesity-associated disorders.

Adult↗
PubMed2001

Chloralhydrate in children undergoing echocardiography.

Transthoracic echocardiography (TTE) is a painless, noninvasive and risk-free diagnostic method in children with known or suspected congenital heart disease. Sedation is frequently required for an optimal achievement of this procedure. The purpose of this study was to determine the safety and efficacy of chloral hydrate (CH) sedation in undergoing TTE. The study population included 360 patients with a median age of 19 months. (2 weeks to 8 years). The median dosage of CH given was 75 mg/kg (ranging 50 and 100 mg), with either oral or rectal administration. Oral administration could not be achieved successfully in 90 patients (20%) because of the bitter taste of the drug, in the other 108 patients (30%), vomiting occurred immediately after drug administration. Prior to CH administration and until discharge; respiratory rate; heart rate, blood pressure and oxygen saturation were recorded. Sedation was successfully achieved in 342 (95%) of the patients. No child had a clinically significant change in heart rate, blood pressure and respiratory rate during sedation. There were also no significant differences in heart rate, respiratory rate, blood pressure and oxygen saturation before and after sedation. Although CH has a bitter taste and is a gastric irritant for oral medication, because of the minimal side effects and efficacy for sedation, it remains as a safe and successful drug for use in children for TTE.

Analysis of Variance↗
PubMed2001

Lower arrythmogenic risk of low dose albuterol plus ipratropium.

OBJECTIVE: Wheezy infants are in need of urgent bronchodilatation owing to their intermittent bronchoconstriction. beta 2 agonists are frequently used in emergencies and have previously shown to increase the QT dispersion (QTd), which may be associate with high risk of cardiac arrhythmia, in asthmatics. However, effect of low dose beta 2 agonist therapy in combination with the anticholinergic agents on QTd in wheezy infants is not known. This study aimed to assess the effect of standard dose of nebulized albuterol (NAB) and low doses of NAB combined with ipratropium-bromide (NIB) on QTd in wheezy infants. METHODS: Twenty-nine children, under 2 years old, with the diagnosis of wheezy infant with acute exacerbation were enrolled in the study. Thirteen were treated by standard dose of NA therapy (0.15 mg/kg) and low doses of NAB (0.075 mg/kg) plus NIB (250 micrograms/dose) therapy was given to the remaining subjects. Respiratory distress score, O2 saturation and side effects were studied and QTd were measured from the standard electrocardiograms at baseline and after treatment. Significant improvement was achieved in clinical score and oxygenation of both groups. RESULT: The evaluation of the corrected QTd (QTcd) showed that there was no significant difference between pretreatment values of both groups (p > 0.05). However, while there was no statistically significant difference in the pre and post-treatment values of QTcd of infants treated with combination therapy, QTcd was found to be significantly increased in NAB group after treatment (p < 0.05). CONCLUSION: Our results suggest that, while clinical improvement is same, the increase of the QT dispersion is more prominent with the use of standard dose of NAB compared to low dose NAB plus NIB therapy. So, low dose of beta 2 agonist in combination with anticholinergic agents may much safer than the use of standard dose of beta 2 agonists alone in regard to preventing the possibility of arrythmogenic effects in wheezy infants with acute exacerbation.

Albuterol↗
PubMed2001

Effects of the hypo-osmotic swelling test on the outcome of intracytoplasmic sperm injection for patients with only nonmotile spermatozoa available for injection: a prospective randomized trial.

OBJECTIVE: Hypo-osmotic swelling test (HOST) has been shown to be an effective method for the selection of live sperm. On-going pregnancies were obtained by using HOST-selected sperm. The aim of this study was to evaluate the effect of using HOST-selected "live" sperm versus nonselected sperm on the outcome of intracytoplasmic sperm injection cycles when only nonmotile sperm were available for injection. DESIGN: Prospective randomized study. SETTING: Governmental tertiary care hospital. PATIENT(S): Thirty ICSI cycles with no motile sperm were included in this study. INTERVENTION(S): For the HOST group, potentially live spermatozoa detected by hypo-osmotic reaction of the tail were injected into oocytes. For the No-HOST group, the sperm were randomly injected into the oocytes without checking the viability. MAIN OUTCOME MEASURE(S): The fertilization, cleavage, embryo quality, pregnancy, and implantation rates were assessed for the two groups. RESULT(S): Among 30 cycles, 15 fall into each group. Fertilization, cleavage rates, and the number of good quality embryos were similar between two groups. CONCLUSION(S): HOST-selected live spermatozoa can be safely used for intracytoplasmic sperm injection to establish pregnancies. There is a tendency for higher pregnancy and implantation rates to result, but it does not reach statistical significance.

Embryo Implantation↗
PubMed2001

Standard dose of inhaled albuterol significantly increases QT dispersion compared to low dose of albuterol plus ipratropium bromide therapy in moderate to severe acute asthma attacks in children.

BACKGROUND: Beta-2 agonist therapy has previously shown to increase the QT dispersion (QTd) in asthmatic patients and increased QTd has been well documented in association with cardiac arrhythmias and sudden death. However, the data concerning the effect of low doses of beta-2 agonist therapy in combination with the anticholinergic agents to potentiate bronchodilatation on QTd in asthmatic children are limited. The objectives of this study was to investigate the changes on QTd during both the standard dose of nebulized albuterol therapy and low dose nebulized albuterol plus inhaled ipratropium therapyn to assess the potential arrhythmogenic risk of these two treatment strategies in children with acute asthmatic attacks. METHODS: Forty-three children with the diagnosis of moderate to severe acute asthma were enrolled in the study. Standard dose of nebulized albuterol therapy (0.15 mg/kg) were administered to 20 patients (group 1) and low dose of nebulized albuterol (0.075 mg/kg) plus nebulized ipratropium bromide therapy (250 microg/dose) were given to the remaining 23 patients (group 2). Respiratory distress score, peak expiratory flow rate, arterial blood pressure, O2 saturation, serum potassium and urea nitrogen levels were studied and QT interval parameters were measured from the standard 12-lead electrocardiograms at baseline and after treatment. RESULTS: Significant improvement was achieved in respiratory distress score and peak expiratory flow rate after three dose inhalation. No significant difference was observed between the pre and post-treatment values of serum potassium, blood urea nitrogen, O2 saturation and arterial blood pressure values. The evaluation of the corrected QTd (QTcd) showed that while there was no statistical difference in the pre and post-treatment values in group 2 (30.4+/-3.1 msn vs 32.1+/-3.9 msn), QTcd was found to be significantly increased in group 1 after treatment (29.0+/-3 msn vs 40.6+/-5.1 msn, P<0.0001). CONCLUSION: The data of the present study suggest that the increase of the QTd is more prominent with the use of a standard dose of albuterol compared to low dose albuterol plus ipratropium therapy. Therefore, it may be concluded that a low dose of albuterol plus ipratropium bromide therapy may be preferred to avoid rhythm disturbances in asthmatic children.

Acute Disease↗
PubMed2001

Non-invasive evaluation of the adaptations of cardiac function in the neonatal period: a comparison of healthy infants delivered by vaginal route and caesarean section.

Postnatal adaptations of cardiac hemodynamics in infants born vaginally or by caesarean section may be different. These cardiac functions were evaluated by Doppler echocardiography to assess adaptation differences. Cardiac output, heart rate, stroke volume, mean arterial pressure, total systemic vascular resistance, ejection fraction, and ductus arteriosus diameter were determined and compared at 1, 24 and 72 h of life in 22 infants born vaginally (group 1) and 23 born by caesarean section (group 2). One hour after delivery, heart rate, mean blood pressure, and total systemic resistance were found to be higher in group 1 infants (P < 0.01, P < 0.05, P < 0.05 respectively). Stroke-volume measurements were significantly higher in group 2 (P < 0.05). The ejection fraction and cardiac output values were similar in both groups. At 24 and 72 h, no significant differences were observed in measurements of infants born vaginally or by caesarean section. We did not find a parameter negatively affecting healthy newborns in either mode of delivery. However, under pathological conditions affecting the cardiovascular system at 1 h of life, including perinatal infections and hypoxemia, a lower stroke volume, higher heart rate, higher mean blood pressure, and higher peripheral resistance may cause additional work load to the cardiovascular system in infants born vaginally.

Cesarean Section↗
PubMed2001

Poor correlation between "fix-follow-maintain" monocular/binocular fixation pattern evaluation and presence of functional amblyopia.

PURPOSE: To assess the reliability of visual screening with fix- follow-maintain (FFM) method in early detection of amblyopia in children who are not able to cooperate in testing with Allen Figures or Snellen E-chart. METHODS: Followup records of 89 patients that were examined in our pediatric ophthalmology department between May 1996 and May 1999 were evaluated retrospectively. The visual acuities that were measured with FFM method at the first visit were compared with the visual acuity levels that were measured with the Snellen E-chart at later followup visits. Functional amblyopia was defined as a difference of 2 or more Snellen lines between the two eyes. RESULTS: Amblyopia was later definitively diagnosed on the E-chart in only 17 (32.6%) of the 52 eyes that were estimated to have a significantly lower visual acuity than the fellow eye with the FFM method. Sensitivity of the FFM method in diagnosing amblyopia was found to be 53.1% and the specificity was 38.5%. CONCLUSIONS: The use of the FFM monocular/binocular fixation pattern to determine visual acuity and the possible presence of amblyopia is so insensitive, and so unspecific, that its reliability is very low and the results of such testing are therefore virtually useless, if not medically hazardous. There is, therefore, a need to make more universally available more sophisticated tests of vision (preferential looking, VEP); where they are not available, further emphasis should be placed on Snellen equivalent vision testing as with Allen Cards, Tumbling E, HOTV Test, Lea Figures etc. so as to obtain an accurate direct visual acuity at as young an age as possible. Amblyopia treatment should not be initiated solely on the basis of FFM testing.

Amblyopia↗
PubMed2000

Day 5 versus day 3 embryo transfer: a controlled randomized trial.

Blastocyst transfer has been suggested to improve implantation rate without affecting pregnancy rate. The aim of this study was to compare the pregnancy and implantation rates of day 3 and 5 transfers in a prospective randomized manner. Patients with four or more zygotes were randomly allocated on day 1 to either day 3 or 5 transfers. Fertilization was achieved through regular IVF or intracytoplasmic sperm injection. Zygotes were kept in Medicult IVF medium for day 3 transfers and transferred into G1.2 and G2.2 on day 1 and 3 respectively for day 5 transfers. The morphologically best two or three embryos or blastocysts were chosen for transfer in both groups. Overall pregnancy rates per embryo transfer were the same (39%) in day 3 and 5 transfers. Implantation rates were 21 and 24% for day 3 and 5 transfers respectively. The pregnancy and implantation rates for day 5 transfers were significantly affected by the availability of at least one blastocyst to transfer and the number of zygotes. The number of good quality embryos on day 3 also significantly affected pregnancy and implantation rates on day 5 transfers. Multiple gestation rate, number of abortions and ongoing pregnancies were similar in both groups. In conclusion, day 3 and 5 transfer had similar pregnancy, implantation and twinning rates. Currently, day 5 transfers have no advantages over day 3 transfers.

Adult↗
PubMed2000

Localization of connective tissue growth factor in human uterine tissues.

Connective tissue growth factor (CTGF) is a recently described heparin-binding mitogen for fibroblasts and smooth muscle cells. The aim of this study was to investigate the production of CTGF by human uterine tissues using immunohistochemical and Northern blotting analyses. For immunohistochemistry, formalin-fixed human proliferative (n = 5), early secretory (n = 5; days 15-19), mid-secretory (n = 5; days 20-23), late secretory (n = 5; days 24-28) endometrial, and decidual (n = 5) tissues were stained using a highly specific affinity-purified polyclonal antibody raised against residues 81-94 of human CTGF. Myometrial (n = 5) and leiomyoma (n = 5) tissues were also used for CTGF immunochemistry. In proliferative endometrium, epithelial and vascular endothelial cells showed strong CTGF immunoreactivity, whereas stromal cells were negative or only weakly positive for the CTGF protein. Throughout the entire secretory stage, CTGF was detected in epithelial and endothelial cells of endometrium. Stromal cells showed strong immunoreactivity to CTGF only in oedematous areas for early and mid-secretory endometrium, and in decidualized regions of late secretory endometrium. During pregnancy, the decidual, epithelial and endothelial cells of the endometrium were all immunoreactive to CTGF. In myometrial and leiomyoma samples, CTGF immunoreactivity was found only in the endothelial cells. Northern blotting of mRNA from normal uterus (n = 2) or leiomyoma (n = 6) using a 320 bp human CTGF cDNA probe revealed a single 2.4 kb transcript. This study is the first to demonstrate CTGF gene expression and localization of its encoded protein in human uterine tissues. The cell- and cycle-specific localization of CTGF support a role for this molecule in regulating aspects of uterine cell growth, migration, and/or matrix production during the menstrual cycle and pregnancy.

Adult↗
PubMed1999

Advanced surgical sperm recovery is a viable option for intracytoplasmic sperm injection in patients with obstructive or nonobstructive azoospermia.

OBJECTIVE: To determine whether advanced sperm retrieval is appropriate in cases of obstructive and nonobstructive azoospermia. DESIGN: Prospective controlled study. SETTING: Tertiary care center. PATIENT(S): Men with obstructive and nonobstructive azoospermia, and their partners. INTERVENTION(S): Surgical sperm retrieval followed by intracytoplasmic sperm injection (ICSI) after 4 or 48 hours. MAIN OUTCOME MEASURE(S): Fertilization and pregnancy rates. RESULT(S): Advanced and fresh surgical sperm recoveries for ICSI were performed in 54 and 230 cycles, respectively. Patient demographics and cycle parameters were comparable. Two hundred forty-one (56.3%) of 428 injected eggs in the advanced retrieval group were fertilized, compared with 955 (56.6%) of 1,686 eggs in the fresh retrieved group (P=.94). There was no statistically significant difference in the pregnancy rates per ET between groups: 38.2% (18 of 47) in the advanced retrieval group and 39.9% (73 of 183) in the fresh sperm recovery group (P=.97). CONCLUSION(S): Testicular and epididymal sperm recovery can be safely performed 48 hours before ICSI. This facilitates planning, and, in cases of failure to retrieve sperm, hCG administration and ovum pick-up can be canceled, thereby reducing costs and eliminating the risk of ovarian hyperstimulation.

Biopsy↗
PubMed1999

Embryo development and pregnancies from in-vitro matured and fertilized human oocytes.

There is an increasing interest in retrieving immature oocytes in the absence of or with limited gonadotrophin exposure, with the aim of maturing them in vitro for embryo transfer purposes. The aim of this report is to present our experience of fertilization, embryonic development and pregnancies from in-vitro maturation cycles. A total of 18 patients underwent 21 cycles in which an average of 8.1 immature oocytes was retrieved after limited exposure to human menopausal gonadotrophin (HMG) and no exposure to human chorionic gonadotrophin (HCG). In one cycle, no oocytes were recovered. The oocytes were cultured for 44 h and 121 oocytes which reached MII were injected with a single spermatozoon. A total of 71 oocytes showed two pronuclei and 53 zygotes cleaved. Forty-four embryos were transferred in 17 cycles. Five weeks after embryo transfer, ultrasound examination indicated the presence of one gestational sac and one fetal heart beat in two patients. The results suggest that in-vitro matured oocytes can undergo fertilization and the resulting embryos may result in pregnancies. However, the success rate was not sufficient to recommend widespread use of the technique without further research.

Cytoplasm↗
PubMed1998

Effects of ovarian source, patient age, and menstrual cycle phase on in vitro maturation of immature human oocytes.

OBJECTIVE: To determine the efficiency of in vitro maturation, expressed by nuclear maturation, of oocytes aspirated during gynecologic surgeries or collected from excised ovaries. To assess the effect of patient age and cycle phase at collection on the oocyte's ability to mature in vitro. To examine the time course of oocyte maturation in vitro. DESIGN: Nuclear maturation based on patient criteria compared. SETTING: University-based IVF program and research center. PATIENT(S): Consented patients undergoing gynecologic surgeries or patients undergoing oophorectomy. INTERVENTION(S): Oocytes were maintained in culture for 48 hours and evaluated for maturation. MAIN OUTCOME MEASURE(S): Nuclear maturation evaluated as germinal vesicle breakdown (GVBD) or progression to the metaphase II (MII) stage. RESULT(S): A significantly higher percentage of oocytes collected during the follicular phase of the menstrual cycle underwent GVBD than did oocytes collected during the luteal phase (60% versus 48%, respectively). The percentage of oocytes reaching the MII stage, from these two groups, was not different. No statistically significant differences in maturation were observed in oocytes from different ovarian sources or from patients >40 or <40 years of age. CONCLUSION(S): These data suggest that oocytes collected during the follicular phase are more likely to undergo GVBD than oocytes collected during the luteal phase. In this study, ovarian source, age, or cycle phase did not influence the final meiotic maturation of oocytes to metaphase II.

Adult↗
PubMed1998

Activin A stimulates meiotic maturation of human oocytes and modulates granulosa cell steroidogenesis in vitro.

OBJECTIVE: To test the hypothesis that activin A promotes in vitro human oocyte meiotic maturation while inhibiting steroid secretion by nonluteinized antral granulosa cells. DESIGN: Prospective randomized controlled study. SETTING: A university medical center. PATIENT(S): Nine women ranging in age from 31-44 years who were undergoing oophorectomy for nonovarian pathology. INTERVENTION(S): Analysis of meiotic maturation of oocytes and steroid secretion by granulosa cells cultured in the presence or absence of activin A. MAIN OUTCOME MEASURE(S): Germinal vesicle breakdown (GVBD) and attainment of metaphase II (MII) in oocytes, and progesterone and E2 secretion by granulosa cells. RESULT(S): Activin A significantly enhanced GVBD (91% vs. 65%) for control and maturation to MII (56% vs. 35% for control) of immature oocytes. Activin A significantly suppressed basal, and inhibin A-and FSH-stimulated progesterone and E2 secretion by nonluteinized granulosa cells. CONCLUSION(S): Activin A is a promoter of oocyte maturation in vitro and a modulator of granulosa cell steroidogenesis in culture.

Activins↗
PubMed1998

Effects of reducing insemination time in human in vitro fertilization and embryo development by using sibling oocytes.

PURPOSE: Recent studies showed a beneficial effect of reducing the time of sperm-oocyte interaction on fertilization, division, and implantation rates of the oocytes obtained from randomized patients. In the present study, the effects of reduced insemination time on fertilization and embryo development were evaluated by using sibling oocytes from the same patient. METHODS: A total of 464 oocytes from 36 patients was randomly allocated to be inseminated for either 1 hr (reduced) or 18 hr (regular). RESULTS: Fertilization rates were not significantly different between reduced (135/229; 59%) and regular (150/235; 64%) groups. Cleavage rates and embryo quality were similar in both groups. A total of 135 embryos (73 from the reduced and 62 from the regular group) was transferred to 36 patients. Thirty-four embryos implanted in 18 patients (25.2% implantation and 50.0% pregnancy rates). CONCLUSIONS: Fertilization, cleavage, and embryo development from 1-hr insemination is comparable, not superior, to those from an 18-hr insemination time, which is commonly used in in vitro fertilization programs. These data suggest that reduced insemination time can be used during in vitro fertilization to avoid unnecessarily longer exposure to spermatozoa.

Adult↗
PubMed1998

Recovery and maturation of immature oocytes in patients at risk for ovarian hyperstimulation syndrome.

PURPOSE: Our purpose was to examine the rate of immature oocyte recovery and their potential for in vitro maturation from canceled human menopausal gonadotropin cycles due to the risk of having ovarian hyperstimulation syndrome develop. METHODS: Patients underwent ultrasound-guided immature oocyte pickup. The number of oocytes recovered from these patients was recorded, and then cultured in vitro. Cumulus expansion and the stage of nuclear maturation were observed after 24 and 48 hr, respectively. RESULTS: Seventeen patients underwent 20 immature oocyte recoveries. A total of 162 oocytes (8.1 oocytes/patient) was obtained. All of the oocytes were enclosed in dense layers of cumulus cells. Among them, 78.4% showed cumulus expansion after 24 hr and 66% completed meiotic maturation to metaphase II after 48 hr in culture. There was only one immature oocyte pickup in which no oocytes were recovered (95% recovery rate). None of the patients had ovarian hyperstimulation syndrome develop. CONCLUSIONS: Immature oocytes can be recovered from canceled human menopausal gonadotropin cycles in patients who are at potential risk for severe hyperstimulation syndrome. These oocytes can be matured in vitro and can be used for clinical and research purposes as well.

Antineoplastic Agents, Hormonal↗