Hale Oktem

Dose-related immunohistochemical and ultrastructural changes after oral methylphenidate administration in cerebrum and cerebellum of the rat

Methylphenidate is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder of children and young adults. Our aim is to investigate dose-dependent dopamine-2 receptor and glial fibrillary acidic protein expression and ultrastructural changes of the rat brain, to demonstrate possible toxicity of the long-term and high dose use of the methylphenidate. In this study, 27 female prepubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) were treated orally with methylphenidate dissolved in saline solution for 5 days per week during 3 months. At the end of the third month, tissues were removed and sections were collected for immunohistochemical and ultrastructural studies. We believe that methylphenidate causes dose-related activation of the dopaminergic system in several brain regions especially in ventral tegmental area and also causing neuronal degeneration and capillary wall structural changes such as basal membrane thickness and augmentation of the pinostatic vesicle in the endothelial cells. Also, increased dose of Ritalin is inducing astrocytes hypertrophy especially astrogliosis in pia-glial membrane and this is the result of the degenerative changes in prefrontal cortex region due to high dose methylphenidate administration. The dose-related accumulation of the astrocytes in capillary wall might well be a consequence of the need for nutrition of the neuronal tissue, due to transport mechanism deficiency related to neuronal and vascular degeneration. Thus, we believe that the therapeutic dose of methylphenidate must be kept in minimum level to prevent ultrastructural changes.

Morphometric Study of a Horseshoe Kidney

Objective: To describe a horseshoe kidney, a congenital anomaly of the upper urinary tract. Clinical Presentation: A case study of horseshoe kidney harvested from a 62-year-old cadaver at Gazi University Medical School is presented. Results: The right and left kidneys were fused at their lower poles by a parenchymal isthmus located ventral to the abdominal aorta and formed a U-shape with two unequal arms.The isthmus of the ectopic kidney was placed obliquely to the left at the level of the fourth and fifth lumbar vertebra. The left kidney was larger and longer than the right one. The kidneys were supplied by three renal arteries arising from the abdominal aorta. Two arteries on the right side supplied blood of the two kidneys, while the third artery that directly originated from the aorta, above the origin of inferior mesenteric artery, supplied the isthmus. Venous drainage of the both kidneys and the isthmus were drained by three veins that opened independently into the inferior vena cava. The right ureter was duplicated in origin. Conclusion: This report shows that knowledge of anomalies such as this is very important in planning and conducting surgical procedures.

Dose‐Dependent Immunohistochemical and Ultrastructural Changes After Oral Methylphenidate Administration in Rat Heart Tissue

Methylphenidate, more commonly known as Ritalin, is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder, one of the most common behavioural disorders of children and young adults. Our aims were to investigate dose‐dependent immunohistochemical D2 expression and ultrastructural changes of the rat heart tissue, and to demonstrate possible toxicity of the long‐term and high dose use of the methylphenidate. In this study, 27 female pre‐pubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) and their control groups, were used. They were treated orally with methylphenidate dissolved in saline solution for 5 days/week during 3 months. At the end of the third month, after perfusion fixation, left ventricle of cardiac tissue was removed. Paraffin, semi‐thin and thin sections were collected and immunohistochemical, terminal deoxynucleotidyl transferase‐mediated Dig‐dUTP nick end labelling assay and ultrastructural studies were performed. In conclusion, we believe that Ritalin is dose‐related affecting dopaminergic system to increase heart rhythm and contraction. Thus, this drug may cause degenerative ultrastructural changes in mitochondrial path.

Morphological variation of carotid artery bifurcation level in digital angiography.

Knowing of the level of carotid artery bifurcation (CB) is important for vascular surgery in the neck, radical neck dissections, carotid sinus baroreceptor stimulation, catheterisations, and aneurysms. The aim of this study was to determine the CB level in relation with the cervical vertebral levels, compare them on the right and the left sides, and investigate the relation of CB level with the length of neck. In this study, 100 conventional carotid angiographies were performed. The CB level was determined in relation with 10 different levels which were the levels of the cervical vertebrae and intervertebral disks, and the relation of CB level with the length of neck was investigated. The right and left CB levels of the patients were also determined, and compared. The highest level of CB was at the level of C2 vertebra, and the lowest level of CB was at the level of C6-C7 intervertebral disk in both male and female. When all patients were taken into consideration, CB level was most frequently seen at the level of C4-C5 (29%) on the right side, and at the level of C4 (26%) on the left side. The CB levels were not symmetrical in 10 female and 23 male. Knowing of the anatomical variations of CB level is important in surgical procedures. The anatomical differences must be taken into consideration since the neighbouring structures of CB change in case of variations. We believe that the results of this study will shed light to planning of all interventional methods concerning common carotid artery and its branches as well as surgery in the neck, and will help to minimise the complications.

Localization of the Carotid Bifurcation According to Hyoid Bone and Mandibular Angle

El objetivo de este estudio fue determinar el nivel de bifurcacion carotidea en relacion con el hueso hioides y el angulo de la mandibula. La arteria carotida comun es la arteria mas grande del cuello, y tiene dos ramas terminales, las arterias carotidas externa e internas. El nivel de bifurcacion muestra variaciones, sin embargo suele situarse a nivel de la cuarta vertebra cervical o en el margen superior del cartilago tiroideo. Por otro lado, la bifurcacion carotidea puede estar situada tan baja como a nivel de la tercera vertebra toracica, o tan alta como a nivel del hueso hioides. En este estudio se utilizaron imagenes angiograficas convencionales de 112 pacientes. Se midieron las distancias de la bifurcacion carotidea con el hueso hioides y el angulo de la mandibula en esas imagenes. Ademas, se determino la diferencia entre los lados derecho e izquierdo. La distancia entre el nivel de bifurcacion carotidea y el angulo de la mandibula se midio, siendo de 21,26 ± 8,57 mm a la derecha y 20,25 ± 8,75 mm en el lado izquierdo, en los hombres, y 19,72 ± 8,89 a la derecha y 18,5 ± 9,25 mm a la izquierda en mujeres. La distancia entre el nivel de bifurcacion de la carotida y el hueso hioides oscilo entre 1,94 ± 12,69 mm en mujeres y, 3,04 ± 9,00 mm en hombres, en el lado izquierdo. La informacion sobre el nivel de bifurcacion carotidea es importante en los procedimientos quirurgicos y radiologicos para determinar el procedimiento quirurgico apropiado y prevenir complicaciones. Creemos que los resultados de este estudio arrojaran luz a la planificacion de las intervenciones relacionadas con la arteria carotida comun.

Dose‐Dependent Immunohistochemical Changes in Rat Cornea and Retina after Oral Methylphenidate Administration

Methylphenidate hydrochloride (MPH), more commonly known as Ritalin, is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder, one of the most common behavioural disorders of children and young adults. The aim of this study was to investigate dose‐dependent immunohistochemical Dopamine 2 receptor (D2) expression and apoptosis in the rat cornea and cornea. In this study, 27 female pre‐pubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) and their control groups, were used. They were treated orally with methylphenidate dissolved in saline solution for 5 days per week during 3 months. At the end of the third month, after perfusion fixation, eye tissue was removed. Paraffin sections were collected for immunohistochemical and terminal deoxynucleotidyl‐transferase‐mediated dUTP‐biotin nick end labelling assay studies. In our study, we observed that the cornea D2 receptor reactivity showed a dose‐related increase after MPH treatment, especially in basal cells of the epithelium and a dose‐dependent decrease in the retinal ganglion cell which was statistically meaningful. Analysis of the cornea thickness results showed no meaningful difference between groups. Apoptotic cell number showed a meaningful increase in the high dose treated group compared to the other groups of the study. The data suggest that Ritalin has degenerative effect on the important functional part of the eye, such as cornea and retina and its activating dopaminergic mechanism via similar neuronal paths, functionally and structurally, to induce morphological changes. As a result, we believe that this morphological changes negatively effecting functional organization of the affected cornea and retina.