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Öğe Correlation between developmental stages of the human heart and gestational ages(SAUDI MED J, 2005) Uysal, II; Karabulut, AK; Salbacak, A; Buyukmumcu, M; Seker, MObjectives: In this study we aimed to investigate the normal developmental pattern of the human fetal heart in second and third trimester, and to evaluate the correlation of the values with the gestational age (GA). Methods: Seventy spontaneously aborted human fetuses with no external malformations were investigated and 11 parameters from each were assessed. The relationship of these parameters with the GA was evaluated by linear regression and correlation analyses using statistical methods. In addition, the values were compared to the gender and sides of the heart using Student t-test. This study was performed at the Department of Anatomy, Meram Medical Faculty, Selcuk University, Konya, Turkey, during the period from 2000 to 2004. Results: There was a statistically significant linear relationship between the heart wall thicknesses, the development of the valves of the heart and GA. The mean values of the right side of the heart were found to be higher than those of the left side, and differences were statistically significant (p < 0.05). Although, most of the parameters were found to be higher in females, only 2 of them were statistically significant. All parameters of the cardiac valves measured were significantly higher in the second trimester. There was no difference regarding the correlation ratio of the trimesters between the pulmonary valve diameter and GA. The measurement of the cardiac valves did not show any differences regarding the gender. Conclusion: This study presents the normal values of the development of the fetal heart in second and third trimester that may provide useful background information for clinical approaches.Öğe An investigation of non-depolarizing muscle relaxants on embryonic development in cultured rat embryos(LIPPINCOTT WILLIAMS & WILKINS, 2004) Karabulut, AK; Reisli, R; Uysal, II; Celik, JB; Ziylan, TBackground and objective: We have investigated the toxic and teratogenic effects of certain non-depolarizing muscle relaxants on embryonic development in cultured rat embryos. Methods: Rat embryos of 9.5 days were explanted and cultured in vitro for 48 h in rat serum. Whole rat serum was used as a culture medium for the control group while different concentrations of atracurium, cis-atracurium, rocuronium and mivacurium were added to rat serum for the experimental groups. Dose-dependent effects of these agents on embryonic developmental parameters were compared using morphological and biochemical methods. Each embryo was evaluated for the presence of any malformations. Results: When compared to the control embryos, the muscle relaxants significantly decreased all growth and developmental parameters dose dependently with an increase in overall dismorphology. Among these malformations, maxillary deformity was most frequently observed. These effects were observed in much lower doses with atracurium and cis-atracurium compared to those with rocuronium and mivacutium. Conclusions: Our results suggest that non-depolarizing muscle relaxants cause dose-dependent toxicity on rat embryos at concentrations much greater than those in clinical practice. Although, these agents seems to have a low potential for causing developmental toxicity during organogenesis, because of the lower toxic effects observed with rocuronium and mivacurium, these agents may be preferred when recurrent administrations are necessary for parturients.Öğe The mechanism of growth-promoting effects of prolactin in embryogenesis - Links to growth factors(KARGER, 1999) Karabulut, AK; Layfield, R; Pratten, MKThe polypeptide hormone prolactin (PRL) has been implicated in the regulation of embryonic growth and development, but the control mechanisms involved in the effects of the hormone are poorly understood. Several investigators suggested that there may be a possible link between the effects of PRL and insulin-like growth factors (IGFs). Recent studies have also shown that ligand-induced activation of PRL receptors leads to tyrosine phosphorylation of multiple intracellular proteins, and tyrosine kinase activation takes place in mediating the mitogenic action of PRL. In order to determine whether IGFs are involved in mediating the growth-promoting effect of PRL, rat embryos were culture in vitro for 48 h in whole rat serum and serum depleted of low molecular weight molecules (30 kD retenate) supplemented with rat PRL in the presence and absence of antisera against rat PRL, IGF I and IGF II. To investigate the effects of inhibiting the signal transduction of the PRL receptors, the embryos were preincubated for 2 h in retenate in the presence of tyrosine kinase inhibitors, tyrphostin 47 and genistein, then rat PRL was added to the culture medium. Embryos cultured in retenate showed severe growth retardation, and the addition of rat PRL caused significant increase in growth and development of the embryos suggesting that embryos may be able to utilize maternally derived PRL during organogenesis. The presence of antiserum against rat PRL abolished the PRL-induced increase in development and antibodies against IGF I and II had a similar effect,, suggesting that IGFs may be involved in the effect of the hormone. The 2-hour preincubation with genistein and tyrphostin also abolished the PRL-induced increase in development. These results indicate that functional PRL receptors are present in rat embryos at this stage which may play an important role in the control of growth and development and this may be linked to growth factors and their receptors.Öğe Possibility of middle meningeal artery-to-petrous internal carotid artery bypass: An anatomic study(THIEME MEDICAL PUBL INC, 2004) Ustun, ME; Buyukmumcu, M; Seker, M; Karabulut, AK; Uysal, II; Ziylan, TThe possibility of creating a middle meningeal. artery (MMA)-to-petrous internal carotid artery (ICA) bypass was investigated in si cadavers (bilaterally). Such a procedure could be used to treat patients with high cervical vascular lesions and those with tumors of the infratemporal fossa invading the high cervical ICA. After a frontotemporal craniotomy, the foramen spinosum and foramen ovale were exposed extradurally. Immediately posterior to the foramen ovale and medial to the foramen spinosum, the petrous portion of the ICA was exposed with a diamond-tipped drill. The MMA was lifted from its groove, and a sufficient length was transected to perform a bypass with the petrous ICA medially. The mean width of the MMA at the site of anastomosis was 2.3 +/- 0.35 mm. The mean length of MMA from the foramen spinosum to the site of the anastomosis was 9.6 +/- 1.7 mm. Based on these measurements, width and length of MMA appear to be sufficient for a bypass with petrous ICA.
