Zebrabalığı'nın (Brachydaniorerio) embriyolojik gelişimi üzerine kadmiyum klorür ve çinko klorür gibi çevre kirleticilerinin etkileri

TEZ2034Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 1996.Kaynakça (s. 49-53) var.vii, 53 s. ; rnk. res. ; 30 cm.

The effects of zinc chloride during early embryonic development in zebrafish (Brachydanio rerio)

This study investigated the developmental toxicity of zinc chloride (ZnCl2) in zebrafish embryos (Brachydanio rerio, Cyprinidae, Cypriniformes). Zebrafish embryos were exposed to 5 different concentrations of ZnCl2, from the blastula stage, for 15 days under static renewal test conditions. As a result, the corresponding median lethal concentration (LC50) value determined for ZnCl2 exposure was 1.36 mg/L (0.65 mg/L as a lone Zn2+ ion). At 1.0 mg/L ZnCl2, the exposed group’s hatching began at 7 days instead of at 4 days, and most of the embryos died in the chorion without hatching at 11 and 12 days. Developmental deformities such as abnormal embryogenesis, low hatchability, delayed hatching, and reduction of newly hatched larvae, and a poor survival ratio (mortality ratio of 1.5 and 10 mg/L concentrations compared to control, P < 0.001), were observed during the embryo larval stage due to zinc exposure. Based on these results, we observed that critical and teratogenic effects of ZnCl2 on embryonic development of zebrafish occurred at concentrations greater than 0.5 mg/L. Moreover, our results confirm that the zebrafish embryo teratogenesis assay can be a useful pretest for integrated biological hazard assessment of chemical agents used in industrial production and drug development technologies.This study investigated the developmental toxicity of zinc chloride (ZnCl2) in zebrafish embryos (Brachydanio rerio, Cyprinidae, Cypriniformes). Zebrafish embryos were exposed to 5 different concentrations of ZnCl2, from the blastula stage, for 15 days under static renewal test conditions. As a result, the corresponding median lethal concentration (LC50) value determined for ZnCl2 exposure was 1.36 mg/L (0.65 mg/L as a lone Zn2+ ion). At 1.0 mg/L ZnCl2, the exposed group’s hatching began at 7 days instead of at 4 days, and most of the embryos died in the chorion without hatching at 11 and 12 days. Developmental deformities such as abnormal embryogenesis, low hatchability, delayed hatching, and reduction of newly hatched larvae, and a poor survival ratio (mortality ratio of 1.5 and 10 mg/L concentrations compared to control, P < 0.001), were observed during the embryo larval stage due to zinc exposure. Based on these results, we observed that critical and teratogenic effects of ZnCl2 on embryonic development of zebrafish occurred at concentrations greater than 0.5 mg/L. Moreover, our results confirm that the zebrafish embryo teratogenesis assay can be a useful pretest for integrated biological hazard assessment of chemical agents used in industrial production and drug development technologies

Clinical and radiological findings in cervicocranial artery dissection

INTRODUCTION: Cervicocranial artery dissections account for 25% of ischaemic strokes in young adults. Numerous risk factors that can damage the structure of the vessel walls have been identified. Dissections can present with various forms of stroke, and are diagnosed using magnetic resonance angiography or digital subtraction angiography. In our study, we aimed to evaluate the clinical and radiological characteristics of cervicocranial artery dissections. METHODS: We retrospectively analysed 45 patients, twenty-nine (64%) males and 16 (36%) females, pre-diagnosed with dissection in the Angiography Unit of the Bakirkoy Mazhar Osman State Training and Research Hospital for Psychiatric and Neurological Diseases. The mean age of females and males was 35 and 39 years, respectively. RESULTS: Forty-one (91%) patients presented with transient ischaemic attack and/or ischaemic stroke. Isolated 12th nerve paralysis was found in one patient, and headache was the only symptom in another. Digital subtraction angiography was performed in all the patients, and bilateral dissection was detected in six patients. From the angiography results, three different types of vessel pathologies were detected: 1) long-segment irregularities (65%), 2) tapering occlusion (35%) and 3) pseudoaneurysm (16%). Radiological follow-up was done for 19 (42%) patients; eight of them completely recovered showing normal imaging findings. DISCUSSION AND CONCLUSION: Dissection can present with a broad clinical spectrum, and it should be suspected in cases with unusual neck movement and mild-to-severe trauma. Digital subtraction angiography is still the best modality for the diagnosis of dissection