Ufuk Ö. Mete

Preventative effect of deferoxamine on degenerative changes in the optic nerve in experimental retrobulbar haematoma

Purpose: Changes in the optic nerve due to the breakdown of blood elements and the effect of deferoxamine on these changes were evaluated.

Ultrastructural Effects of Topical Beta-Adrenergic Antagonists and an Alpha-Adrenergic Agonist on the Rabbit Cornea

In the present study the effects of β-adrenergic antagonist and α-adrenergic agonist drugs on rabbit corneas were evaluated in vivo by using transmission electron microscopy. Twenty-four New Zealand albino rabbits were divided into six groups according to the drug applied. The rabbits to which only balanced salt solution (BSS) or BSS and benzalkonium chloride (BAC) were applied were taken as the control groups. The other four groups consisted of the rabbits to which Timoptic 0.5%, Betagan 0.5%, Betoptic 0.5% and Iopidine 1% were applied, respectively. All of drugs were instilled topically twice daily for 6 weeks. In the BSS group, all layers of the cornea were ultrastructurally normal. In the BSS and BAC group slight epithelial and endothelial changes were found. However, in the other groups, loss of microvilli, increase in glycogen particles, nuclear indentation, widening of the intercellular spaces and cytoplasmic vacuolization in epithelium were observed. No significant abnormality was found in the basal lamina, stroma and Descemet’s membrane. Slight ultrastructural changes were noted in the endothelium such as vacuolization due to dilatation of the endoplasmic reticulum cisternae and focal cytoplasmic lytic areas. The results of this study indicate that various ultrastructural changes occur in groups treated with antiglaucomatous drug and that topical treatment with timolol and apraclonidine for 6 weeks is more toxic to the rabbit cornea than levobunolol and betaxolol.

Ultrastructural changes in rat thyroid tissue after acute organophosphate poisoning and effects of antidotal therapy with atropine and pralidoxime: A single-blind, ex vivo study

BACKGROUND Organophosphate (OP) insecticides are widely used in both agricultural and landscape pest control, and the potential for human exposure to these compounds is significant. OBJECTIVES The aims of this study were to investigate the effects of acute poisoning with the OP methamidophos and the effects of antidotal therapy with atropine and pralidoxime on rat thyroid tissue ultrastructure. METHODS In this single-blind, ex vivo study, male Wistar albino rats weighing 220 to 230 g were divided into 4 treatment groups. Group 1 received a median lethal dose of methamidophos (30 mg/kg) via oral gavage. Group 2 received saline via oral gavage and served as the control group for group 1. Group 3 received methamidophos (30 mg/kg) via oral gavage, and after 8 minutes atropine 0.05 mg/kg and pralidoxime chloride (2-FAM) (40 mg/kg) were administered intraperitoneally (IP). Atropine was titrated to reverse signs of cholinergic excess. Group 4 received saline via oral gavage followed by IP injections and served as the control for group 3. Rat thyroid tissues were examined using electron microscopy, and the histologic changes were examined by a histopathologist who was blinded to treatment. All rats were euthanized by intracardiac blood collection. The rats in groups 1 and 2 were euthanized 8 minutes after treatment. The rats in groups 3 and 4 were euthanized 96 hours after treatment. RESULTS Thirty-four male rats (aged 16 weeks) were included in the study. The rats were grouped accordingly: group 1 (n = 10); group 2 (n = 7); group 3 (n = 10); and group 4 (n = 7). The mean (SD) pseudocholinesterase (FCE) activity was significantly lower in the methamidophos-treated rats (group 1) compared with the corresponding control group (group 2) (32.6 [17.0] vs 579.4 [59.0] U/L, respectively; P < 0.001). PCE activity was significantly higher in rats treated with atropine and 2-PAM (group 3) (392.5 [39.4] U/L; P < 0.001) compared with those not receiving antidotal therapy (group 1). Group 1 experienced changes in thyrocytes and organelles that were not detected in the antidote-treated rats in group 3. These changes included follicular cell nuclei exhibiting an increase in chromatin content, pyknotic nuclei, mitochondrial degeneration, dilated granular endoplasmic reticulum cisternae, reduced microvilli, and intraluminal cellular debris. Within follicular cells, formation of vacuoles filled with fine granular material was noted. CONCLUSION Acute OP poisoning was associated with histopathologic effects in rat thyroid tissue that appeared to be mitigated by antidotal therapy in this small animal study. More extensive studies using immunohistochemical methods are needed.

Ultrastructural and surface-area changes of acute and traditionally expanded full thickness skin grafts

The purpose of this study was to determine the effect of expansion on the survival of full thickness skin grafts. In eight pigs 300 ml rectangular tissue expanders were placed into subcutaneous pockets. In four pigs (group I), the expanders were inflated rapidly with a mean 200 ml saline. In the other four pigs (group II), a mean total of 300 ml saline was injected in weekly increments over eight weeks. At the completion of expansion, full thickness skin grafts were taken from the expanded area and sutured back to the donor defects. In both groups surviving graft areas were similar to controls (p greater than 0.06). This study showed that acute and traditional expansion does not lead to increased loss of full thickness skin grafts of the expanded skin.

Ultrastructural Effects of Acute Organophosphate Poisoning on Rat Kidney

We investigated the ultrastructural effects of the organophosphate compound methamidophos and treatment with atropine and pralidoxime (2-PAM) on rat kidneys. Male Wistar albino rats were assigned to four groups. Group 1 received 30 mg/kg methamidophos, the LD50 for this compound in rats, via oral gavage. Group 2 received only physiologic saline. Group 3 rats received 30 mg/kg methamidophos and were treated with 2-PAM and atropine via intraperitoneal injection when cholinergic symptoms were noted. Group 4 served as a control, and received physiologic saline in equivalent volumes and routes to Group 3. Kidney tissues were prepared for electron microscopic studies. No ultrastructural changes were detected in Group 1 after acute poisoning with methamidophos and in Group 3 treated with antidotes after poisoning. Acute organophosphate poisoning and antidotal treatment in this model are not associated with histopathological changes in the rat kidney but the models with different organophosphate compounds, by administrating the different dosages, may be more illuminative in explaining the effects of these chemicals in kidney.

Ultrastructural changes in the contralateral lung tissue following unilateral lung ischemia: an experimental study in rabbits.

AbstractPurpose. To investigate the acute ultrastructural changes that may occur in the contralateral nonischemic lung tissue after unilateral ischemia of a lung in a rabbit model. Methods. The animals were divided into three main groups of eight; namely, a 2-h procedure group, a 4-h procedure group, and an 8-h procedure group. Each of these groups was further divided into two subgroups of four rabbits each; namely, a control group, given a sham operation without any ischemic insult, and an ischemia group, in which the main pulmonary arteries, the pulmonary veins, and the main bronchi of the left lungs were ligated after thoracotomy. Tissue samples were taken from the left and right lungs to examine the ultrastructural changes after 2, 4, and 8 h of ischemia. Each sample was given a semiquantitative histological injury score. Statistical analysis was done by the Mann-Whitney U-test. Results. Contralateral ultrastructural damage, evident by heterochromatin in the nuclei, mitochondrial degeneration, cisternal widening of the endoplasmic reticulum, increased lipid droplets, and lysosomes, was determined by electron microscopy after unilateral lung ischemia. The contralateral lung injury was significantly correlated with the duration of ischemia. Conclusions. Unilateral lung ischemia affected the bilateral lungs in a rabbit model. Therefore, in operations such as single-lung transplantation, pulmonectomy, or lobectomy, if the procedure is unnecessarily prolonged, the contralateral lung may be damaged, which could seriously affect the prognosis of the patient.

Effects of vitamin D on ovary in DHEA-treated PCOS rat model: A light and electron microscopic study

ABSTRACT Aim: The aim of this study was to investigate the effects of vitamin D treatment on ovary in experimentally designed polycystic ovary syndrome of female rats using light and electron microscopic techniques. Methods: Twenty-four female pre-pubertal rats were divided into control, DHEA and DHEA+Vit.D groups. In DHEA group, the PCOS rat model was developed by 6mg/kg/day dehydroepiandrosterone administration as subcutaneously injections. In DHEA+Vit.D group, 6 mg/kg/day DHEA and 120ng/100g/week 1,25(OH)2D3 was performed simultaneously. Controls were injected with vehicle alone. At the end of the 28 days, blood samples were collected and the ovarian tissues were taken for histological examinations. Results: FSH, LH levels, LH/FSH ratio, and testosterone levels showed a significant increase in DHEA group when compared with the control group. Moreover, these measurements were lower in the treatment group than the DHEA group. In DHEA group, increased number of atretic follicles and cystic follicles were seen with light microscopic analysis. Cystic follicles with attenuated granulosa cell layers and thickened theca cell layers and lipid accumulation in interstitial cells were observed by electron microscope. It is observed that atretic and cystic follicles were decreased as a result of vitamin D treatment. Conclusion: Our results indicate the curative role of vitamin D treatment on the androgen excess in PCOS rat model which causes abnormalities in ovarian morphology and functions. Vitamin D has positive effects on the hormonal and structural changes observed in PCOS, but it has been concluded that long-term use may be more beneficial.

Investigation of the uterine structural changes in the experimental model with polycystic ovary syndrome and effects of vitamin D treatment: An ultrastructural and immunohistochemical study

In this study, we aimed to investigate the structural changes seen in the endometrium in experimental PCOS rat model and the effects of vitamin D treatment on these changes at immunohistochemical and electron microscopic levels. 24 prepubertal female rats were divided into three groups. Two groups were injected with dehydroepiandrosterone and one of them was treated with 1,25(OH)2 D3 at the same time. The control group was injected with sesame oil. At the end of the 28th day, the blood samples were collected. Uterus tissues were prepared for light and electron microscopic examinations. Epithelial, stromal and endometrial thickness measurements were investigated. Immunohistochemical staining was applied against caspase-3 and Ki-67. Serum AMH and estradiol levels were higher in PCOS group compared to the control group. Serum progesterone levels were similar in all groups. Endometrial, epithelial and stromal thickness measurements were increased in PCOS group compared to the control group, and decreased in the vitamin D treatment group compared to the PCOS group. Light and electron microscopic results of PCOS group showed an increase in apoptosis and proliferation. In the PCOS group, immunohistochemical staining of caspase-3 and Ki-67 were found to be higher than in the control group, but stainings were decreased with vitamin D treatment compared to PCOS group. Structural changes observed in endometrium may be related to implantation problems seen in patients with PCOS. Our studies suggest that vitamin D therapy may be beneficial in these patients.

Comparison of Amphotericin B Lipid Complex (Abelcet) and Liposomal Amphotericin B (Ambisome) on Rat Kidney: a Morphological Evaluation

El objetivo de nuestro estudio fue comparar los efectos nefrotoxicos de la anfotericina B liposomal (AmBisome) y anfotericina B en complejo lipidico (Abelcet) sobre rinones de ratas, en el tratamiento de aplicacion a corto (14 dias) y largo plazo (28 dias). Fueron incluidas en el estudio 36 ratas Wistar machos, divididas en seis grupos (n = 6). Los Grupos 1 y 4 fueron grupos de control mediante la administracion intraperitoneal (ip) de 0, 9 Molar de suero fisiologico durante un periodo de 14 y 28 dias respectivamente. Los Grupos 2 y 3 fueron tratados con 5 mg/kg de Ambisome y 5 mg/kg Abelcet durante 14 dias respectivamente, y finalmente los grupos Grupos 5 y 6 tratados con los mismos agentes durante 28 dias, respectivamente. Luego, las ratas fueron perfundidas via transcardiaca, y se tomaron muestras de la corteza y la medula renal. Las micrografias de los grupos 1 y 4 se observaron normal. En el tratamiento a corto plazo, algunos cambios morfologicos se observaron en las celulas del tubulo proximal en el grupo 3, mientras que en el grupo 2 los graficos se observaron normales. Sin embargo, despues de utilizar la droga a largo plazo en los grupos 5 y 6 hubo vacuolizacion, aumento de las estructuras lisosomales y un profundo plegamiento basal de las celulas del lumen tubular. Estos experimentos establecen que el dano renal se produce en el uso a corto y largo plazo de Abelcet, y largo plazo de Ambisome.

Ultrastructural and hormonal changes in the contralateral adrenal gland in unilateral adrenal gland ischemia: An experimental study in rats

While it is well known that unilateral tissue ischemia may result in contralateral damage in some paired organs, there is no universally accepted mechanism to explain why these contralateral changes occur. The aim of the present study was to investigate the ultrastructural and hormonal changes that occur in the contralateral nonischemic adrenal gland after unilateral ischemia of an adrenal gland in a rat model. The animals were divided into four groups of four rats each; namely, a control group which received a sham operation without any ischemic insult, a 2-h ischemic group, a 4-h ischemic group, and an 8-h ischemic group. The left adrenal blood vessels were ligated in all ischemia groups and blood samples were taken for hormonal study 2, 4, and 8h later, after which bilateral adrenalectomy was performed to determine the ultrastructural changes. The plasma concentrations of aldosterone and cortisol were determined by radioimmunoassays. There was an increase in both aldosterone and cortisol levels related to the duration of the ischemia, but the differences among the groups were not statistically significant. Contralateral ultrastructural damage such as heterochromatin in nuclei, mitochondrial degeneration, endoplasmic reticulum cisternal widening, increased lipid droplets, and lysosomes, were demonstrated electron-microscopically after unilateral adrenal ischemia.