Therapeutic effects of melatonin in long-term exposure to 2100MHz radiofrequency radiation on rat sperm characteristics / Efectos terapéuticos de la melatonina en la exposición a largo plazo a la radiación de radiofrecuencia de 2100MHz en las características del esperma de rata

Introduction: Radiofrequency electromagnetic fields (RF-EMFs) are one of the risk factors for male reproductive health and melatonin can be an ideal candidate for therapeutic development against RF-induced male fertility problems due to its antioxidant properties. The possible therapeutic role of melatonin in the destructive effects of 2100MHz RF radiation on rat sperm characteristics is investigated in the present study. Methods: Wistar albino rats were divided into four groups and the experiment continued for ninety consecutive days; Control, Melatonin (10mg/kg, subcutaneously), RF (2100MHz, thirty minutes per day, whole-body), and RF+Melatonin groups. Left caudal epididymis and ductus deferens tissues were placed in sperm wash solution (at 37°C) and dissected. The sperms were counted and stained. Measurements of the perinuclear ring of the manchette and posterior portion of the nucleus (ARC) were performed and the sperms were examined at an ultrastructural level. All of the parameters were evaluated statistically. Results: The percentages of abnormal sperm morphology were significantly increased with RF exposure, while the total sperm count was significantly decreased. RF exposure also showed harmful effects on acrosome, axoneme, mitochondrial sheath, and outer dense fibers at the ultrastructural level. The number of total sperms, sperms with normal morphology increased, and ultrastructural appearance returned to normal by melatonin administration. Discussion: The data showed that melatonin may be a beneficial therapeutic agent for long-term exposure of 2100MHz RF radiation-related reproductive impairments. (AU)

Introducción: Los campos electromagnéticos de radiofrecuencia (RF-EMF) son uno de los factores de riesgo para la salud reproductiva masculina y la melatonina puede ser un candidato ideal para el desarrollo terapéutico contra los problemas de fertilidad masculina inducidos por RF debido a sus propiedades antioxidantes. En el presente estudio se investiga el posible papel terapéutico de la melatonina en los efectos destructivos de la radiación RF de 2100MHz en las características del esperma de rata. Métodos: Se dividieron ratas albinas Wistar en 4 grupos y se continuó el experimento durante 90 días consecutivos: grupos control, melatonina (10mg/kg, por vía subcutánea), RF (2100MHz, 30min por día, cuerpo entero) y RF+melatonina. Los tejidos del epidídimo caudal izquierdo y del conducto deferente se colocaron en una solución de lavado de esperma (a 37°C) y se diseccionaron. Los espermatozoides fueron contados y teñidos. Se realizaron mediciones del anillo perinuclear del manchette y de la porción posterior del núcleo (ARC) y se examinaron los espermatozoides a nivel ultraestructural. Todos los parámetros fueron evaluados estadísticamente. Resultados: Los porcentajes de morfología anormal de los espermatozoides aumentaron significativamente con la exposición a RF, mientras que el recuento total de espermatozoides disminuyó significativamente. La exposición a RF también mostró efectos nocivos en el acrosoma, el axonema, la vaina mitocondrial y las fibras densas externas a nivel ultraestructural. El número total de espermatozoides, los espermatozoides con morfología normal aumentaron y la apariencia ultraestructural volvió a la normalidad mediante la administración de melatonina. Discusión: Los datos mostraron que la melatonina puede ser un agente terapéutico beneficioso para la exposición a largo plazo de las deficiencias reproductivas relacionadas con la radiación de RF de 2100MHz. (AU)

Therapeutic effects of melatonin in long-term exposure to 2100MHz radiofrequency radiation on rat sperm characteristics.

INTRODUCTION: Radiofrequency electromagnetic fields (RF-EMFs) are one of the risk factors for male reproductive health and melatonin can be an ideal candidate for therapeutic development against RF-induced male fertility problems due to its antioxidant properties. The possible therapeutic role of melatonin in the destructive effects of 2100MHz RF radiation on rat sperm characteristics is investigated in the present study. METHODS: Wistar albino rats were divided into four groups and the experiment continued for ninety consecutive days; Control, Melatonin (10mg/kg, subcutaneously), RF (2100MHz, thirty minutes per day, whole-body), and RF+Melatonin groups. Left caudal epididymis and ductus deferens tissues were placed in sperm wash solution (at 37°C) and dissected. The sperms were counted and stained. Measurements of the perinuclear ring of the manchette and posterior portion of the nucleus (ARC) were performed and the sperms were examined at an ultrastructural level. All of the parameters were evaluated statistically. RESULTS: The percentages of abnormal sperm morphology were significantly increased with RF exposure, while the total sperm count was significantly decreased. RF exposure also showed harmful effects on acrosome, axoneme, mitochondrial sheath, and outer dense fibers at the ultrastructural level. The number of total sperms, sperms with normal morphology increased, and ultrastructural appearance returned to normal by melatonin administration. DISCUSSION: The data showed that melatonin may be a beneficial therapeutic agent for long-term exposure of 2100MHz RF radiation-related reproductive impairments.

The effect of di-n-butyl phthalate on testis and the potential protective effects of resveratrol.

This study aimed to observe the possible protective effects of resveratrol (RSV) against the damage of di-n-butyl phthalate (DBP) on the testis. The study was conducted in 6 groups of rats with 6 animals in each group aged 20 days. The groups include group 1: control group; group 2: solvent (carboxymethylcellulose (CMC), 10 ml/kg); group 3: 500 mg/kg/day DBP; group 4: 500 mg/kg/day DBP + 20 mg/kg/day RSV; group 5: 1000 mg/kg/day DBP; and group 6: 1000 mg/kg/day DBP + 20 mg/kg/day RSV. Groups were treated by gavage for 30 days. Indirect immunohistochemical staining was performed with c-kit, AT1, and ER-α antibodies. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) method was used for apoptosis. It was found in the DBP-applied groups the C-kit immunostaining, which is parallel to increasing dose, decreased in comparison with the control. C-kit reactivity was similar to that of the control group in the group applied with 500 mg/kg/day + RSV; however, the reactivity was not same in the 1000 mg/kg/day DBP-applied group. It was observed that the reactivity of AT1 increased in the DBP-applied groups. RSV reversed these changes with its protective effects. While there was not much difference between the groups in terms of estrogen receptor reactivity, it was observed that the high dose of DBP reduced the level of estrogen receptor and the resveratrol was not at enough levels in all doses. In TUNEL analysis, high doses of DBP increased the apoptosis in all types of cells; nevertheless, the resveratrol application decreased the apoptosis in the low-level DBP dose. In the statistical analysis, while the length of epithelium and the diameter of seminiferous tubules decreased for all the other groups, it reverted to its original state in the RSV-applied groups. In conclusion, DBP (with increasing dose) administration caused cycle and hormonal changes in testis, resveratrol were recovered the cyclic changes but in hormonal changes, RSV is efficient too but inadequate.

Biochemical and histopathological effects of catechin on experimental peripheral nerve injuries.

AIM: Catechin is a type of polyphenol, along with epicatechin, epigallocatechin, and epigallocatechin-gallate (EGCG). This study aims to investigate the effect of EGCG, a major metabolite of catechin, which is the principle bioactive compound in green tea, on rats with peripheral nerve injury. MATERIAL AND METHODS: A total of 74 rats were divided into six groups, namely the control, the trauma, the normal saline, a 25mg/kg EGCG, a 50mg/kg EGCG and a daily consumption group (10mg/kg EGCG was given intraperitoneally for 14 days before the trauma). Except the first group, the other groups underwent a 1-minute sciatic nerve compression by clip with 50gr/cm2 pressure. Nerve samples were obtained at 28 day after trauma for the biochemical and histopathological analysis. RESULTS: Our study showed that the Daily consumption, 25mg/kg EGCG and 50mg/kg EGCG groups demonstrated statistically significant decreased lipid peroxidation levels and particularly daily consumption, and the 25mg/kg EGCG group showed a favourable reduction of degeneration and edema histologically. CONCLUSION: This study shows that Catechin and its derivatives have a protective effect on peripheral nerve injury.

Protective effects of resveratrol against di-n buthyl phthalate induced toxicity in ductus epididymis and ductus deferens in rats.

OBJECTIVE: This study aimed to observe the possible protective effects of resveratrol (RSV) against damage induced by di-n-butylphthalate (DBP), on the ductus epididymis and deferens in rats. MATERIALS AND METHODS: Six groups of rats were used in the experiment: Group 1: Control group; Group 2: Solvent (carboxymethylcellulose (CMC), 10 ml/kg); Group 3: 500 mg/kg/day DBP; Group 4: 500 mg/kg/day DBP+20 mg/kg/day RSV; Group 5: 1000 mg/kg/day DBP; Group 6: 1000 mg/kg/day DBP + 20 mg/kg/day RSV. Groups were treated by gavage for 30 days. Immunohistochemical, electronmicroscopic and histomorphometric examinations were carried out in the epididymis and deferens. RESULTS: In the ductus epididymis and deferens mitochondrial crystolysis, exfoliation of the stereocilia and openings in lateral surface increased with DBP dosage, but these structures were recovered with RSV. DBP reduced the epithelial height of epididymis and vas deferens. Lumen dilatation was observed in both tissues. These disorders may lead to dysfunction of epithelial absorption. In the TUNEL examinations in both tissues, there were no apoptotic cells or apoptotic bodies. CONCLUSION: In conclusion, DBP administration caused structural degeneration in the epididymis and deferens, parallel to dose evaluation and RSV can reverse these changes with its protective effects.

The neuroprotective effects of rituximab in rat spinal cord injury model: an immunohistochemical study.

AIM: In the present study, we investigate the neuroprotective effects of rituximab, a monoclonal antibody directed towards B cell mediated humoral immunity, on a rat spinal cord injury (SCI) model with immunohistochemical methods. MATERIAL AND METHODS: Twenty-four rats were used for the study. Rats were divided as control, SCI, and rituximab-treated SCI groups. Intraperitoneal rituximab administration was performed on days 0, 3 and 5 in the third group. Rats were sacrificed 7 days after trauma. Antibodies against IL-1ß, IL-6, TNF-α and CD20 were studied with the ELISA method together with electron microscopic analysis. RESULTS: It was found that rituximab suppressed oligodendrocytes at the phagocytic stage but was still inefficient for the regenerative phase. TNF-α expression was markedly increased in rats subjected to SCI and suppressed after rituximab treatment. Decreased CD20 expression was another prominent finding in rats under rituximab therapy. However, expressions of IL-1ß and IL-6 were both increased in glial cells without significant change after rituximab administration. CONCLUSION: TNF-α expression was augmented at the level of SCI both in neuronal and glial cells, particularly in oligodendrocytes. All were suppressed after rituximab administration and rituximab reduced CD20 expression both in neuronal and supportive glial cells which may be related to neural healing.

Tobacco-induced neuronal degeneration via cotinine in rats subjected to experimental spinal cord injury.

OBJECTIVES: Cigarette smoke contains over 4000 chemicals including well-characterized toxicants and carcinogens, among which is cotinine. Cotinine is the principal metabolite of nicotine that has adverse affects on the microcirculation via vasoconstriction, hypoxia and the wound-healing cascade. Its impact on spinal cord injury (SCI) has not been investigated yet. The aim of the present study is to investigate the cotinine effect on SCI. METHODS: 48 male Wistar rats were divided into six groups as follows: sham-control, sham-trauma, vehicle-control, vehicle-trauma, cotinine-control, and cotinine-trauma. Initially, a defined concentration of cotinine blood level was maintained by daily intraperitoneal injection of cotinine for 14 days in the cotinine groups. The concentration was similar to the cotinine dose in the blood level of heavy smokers. Only ethyl alcohol was injected in the vehicle groups during the same period. Then, SCI was performed by a Tator clip. The cotinine groups were compared with rats subjected to vehicle and sham groups by immunohistochemical biomarkers such as glial fibrillary acidic protein (GFAP) and 2,3-cyclic nucleotide 3-phosphodiesterase (CNP) expressions. Electron microscopic examination was also performed. RESULTS: GFAP-positive cells were noted to be localized around degenerated astrocytes. Marked vacuolization with perivascular and perineural edema was seen in the cotinin consumption groups. These findings showed the inhibition of regeneration after SCI. Similarly, vacuolization within myelin layers was noted in the cotinine groups, which was detected through reduced CNP expression. CONCLUSION: Cotinine, a main metabolite of nicotine, has harmful effects on SCI via GFAP and CNP expression. The findings of the present study support the hypothesis that tobacco causes neuronal degeneration via cotinine.

Bacterial biofilm formation in the middle-ear mucosa of chronic otitis media patients.

Biofilm formation is present in the middle-ear mucosa of chronic otitis media (COM) patients and COM is a biofilm-related disease. Biofilms are organized and complex communities in which bacteria communicate to each other and gain tremendous advantages. In this unique structure, bacteria can diffuse nutrients, gain resistance to antimicrobials agents and host defense mechanisms. Recently bacterial biofilms have been proven to be important in infectious diseases of head and neck region. A prospective case-control study was conducted. The study group comprised of patients with chronic otitis media and patients undergoing surgery for cochlear implantation was involved in the control group. Study group also divided to subgroups SSA and SSB according to history of ear discharge within last six months. Direct microscopy (DM) and transmission electron microscopy (TEM) were used to assess presence of biofilms. Totally 19 patients, 10 with ear discharge history within last 6 months and 9 without discharge comprised the study group. Control group comprised of 9 patients undergone cochlear implantation. In all of the patients with ear discharge history and in two of the patients without ear discharge history, biofilm formation was detected by both DM and TEM. All control group members were free of biofilm formation. The differences were statistically significant between study and control groups (p = 0.002) and between study subgroups (p < 0.001); but not significant between study subgroup without ear discharge history and control group (p = 0.470). In the middle ear mucosa of patients with chronic otitis media, biofilm formation is common, especially when ear discharge history is present.

The morphological evaluation of ipsilateral and contralateral vasa deferentia in a rat model of unilateral spermatic cord torsion.

AIM: Spermatic cord torsion is a surgical emergency that requires early intervention to protect the effected testicle. The literature review about this ischemic reperfusion (I/R) injury reveals not only ipsilateral, but also contralateral testicular and epididymal injuries in a broad fashion. However, there is no data about vas deferens injury related with this surgical emergency. The aim of the study is to evaluate the morphological changes of the vas deferens due to testicular I/R injury. MATERIALS AND METHODS: Eighteen Wistar-Albino rats were allocated to three groups. Bilateral vasa deferentia of control group (Gr C, n = 6) were harvested without any surgical intervention. The torsion group was subjected to 2 h torsion and 2 h detorsion of the left testicle (Gr T, n = 6) and the third group underwent sham operations (Gr S, n = 6). Bilateral vasa deferentia of Gr T and S were harvested after surgery. The either side of the vas deferens was divided into three equal segments and these regions (adjacent to urinary bladder, medial and adjacent to testicle) were evaluated histopathologically. RESULTS: The electron microscopic evaluation of bilateral vasa deferentia of Gr T revealed different degrees of degeneration on either side. The region adjacent to testicle of the contralateral vas deferens was the most effected segment when compared with the other segments. CONCLUSION: In the light of these findings, it can be said that testicular I/R injury effects not only testis and epididymis, but also the adjacent vas deferens. This effect seems to be bilateral, like the testis and epididymis injury. Moreover, it mostly seems to depend on the apoptotic processes.

Histologic and morphologic effects of valproic acid and oxcarbazepine on rat uterine and ovarian cells.

PURPOSE: To determine the histologic and morphologic effects of valproic acid (VPA) and oxcarbazepine (OXC) on rat uterine and ovarian cells. METHODS: Fifty-six female prepubertal Wistar rats (21-24 days old and weighing between 47.5 and 58.1 g) were divided equally into four groups, which were given drinking water (controls), 300 mg/kg/day of VPA, 100 mg/kg/day of OXC or VPA + OXC via gavage, for 90 days. Ovaries and uteri of rats on proestrous and diestrous phases of estrous cycle were extirpated and placed in a fixation solution. The tissue specimens were assessed with apoptosis (TUNEL) staining protocols, eosinophil counting, and electron microscopic techniques. RESULTS: In uteri, apoptosis in stroma, mitochondrial swelling, and cristolysis were observed in the VPA group, and OXC led to negative effects on epithelial cell and intracellular edema. In ovaries, both drugs increased apoptosis and intracytoplasmic edema. Organelle structure disruption was also observed in the OXC group. More conspicuous degenerative modifications were determined in the VPA + OXC group. In uteri, the number of TUNEL-positive luminal epithelial cells was 7.20 +/- 1.32 in controls, and significantly increased to 29.60 +/- 1.58, 34.20 +/- 2.53, and 54.80 +/- 2.04 in VPA, OXC, and VPA + OXC groups, respectively (p < 0.001). The highest number of TUNEL-positive glandular epithelium cells was observed in the VPA + OXC group; however, the number of TUNEL-positive stroma cells was highest in the VPA group. The highest number of eosinophils in stroma was in the VPA group. CONCLUSION: VPA and OXC trigger apoptotic and degenerative effects on rat uterine and ovarian cells. VPA also prevents implantation of embryo to the uterus and causes abortion via endometrial eosinophil infiltration.

The effects of resveratrol on cyclooxygenase-1 and cyclooxygenase-2 mRNA and protein levels in diabetic rat kidneys.

Cyclooxygenase (COX), which have the isoforms of COX-1 and COX-2, is the key enzyme of prostaglandins biosynthesis. Especially, COX-2 is induced in inflammatory disease such as Diabetes Mellitus (DM). Resveratrol (RSV), a natural antioxidant, has a beneficial role in prevention of inflammatory disease. We investigated the changes of COX-1 and COX-2 mRNA expression and protein level in diabetic rat kidney after RSV treatment. Three months-old, 44 Wistar albino male rats, which were divided into six groups such as control group, sodium citrate buffer (sham control) group, diabetic group (DM), Dimethyl Sulfoxide induced control group, RSV treated sham control group (RSV) and RSV treated diabetic group (DM + RSV) were used for the study. Experimental diabetes was induced by intraperitoneal injection of 55 mg/kg Streptozotocin. After the induction of chronic diabetes 10 mg/kg per day RSV was administered intraperitoneally for 4 weeks. In this study. RSV has no significant effect on COX-1 mRNA expression in diabetic rat kidney (P > 0.05). Immunohistochemical study showed that COX-1 expression was slightly inhibited in RSV group and was not significantly supressed in DM + RSV group. When comparing control and treated groups, there were no significant differences in COX-2 mRNA or protein levels (P > 0.05). In conclusion, our results indicate that resveratrol do not significantly affect COX gene and protein expression. Therefore, different therapy strategies such as combination with other antidiabetic drugs may tried in STZ induced animal model for reducing diabetic symptoms and altering COX-1 and COX-2 mRNA or protein levels.

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.

High dose cotinine may induce neural tube defects in a chick embryo model.

AIM: Nicotine is a well-known agent among 4000 chemicals in cigarettes. About 70 to 80% of nicotine is converted to cotinine, a major metabolite. The aim of the present study is to investigate the effect of cotinine on neural tube development in a chick embryo model. MATERIAL AND METHODS: Sixty fertile, specific pathogen free eggs were divided into 6 groups for this study. In the first group, a fixed cotinine concentration for each egg was calculated just to simulate the concentration of a smoker's blood level. A second experimental group was designed at a higher cotinine concentration. Embryos that succeeded to reach Hamburger-Hamilton stage 12 from each group were then embedded into paraffin for permanent sections. These two groups were compared with eggs subjected to vehicle (standard alcohol and ten times more alcohol concentration) and control groups (saline and sham groups). RESULTS: Embryos of the cotinine (regular dose), vehicle and control groups were normal, but embryos subjected to higher cotinine concentrations were malformed at the cranial part of the thoracic neural tube. CONCLUSION: Association of cotinine with neural tube defects was demonstrated in the present study. Cigarette smoking may induce hazardous effects on neural tube development.

Effects of metformin on mammalian target of rapamycin in a mouse model of endometrial hyperplasia.

OBJECTIVE: The effects of metformin on S6K1, which is a crucial effector of mTOR signaling, and on endometrium were studied in a mouse model of endometrial hyperplasia induced by unopposed estradiol or tamoxifen. STUDY DESIGN: Forty-eight oophorectomized Balb/c mice were randomly assigned to receive saline, tamoxifen citrate (4 mg/kg), 17-beta estradiol hemihydrate (4 mg/kg), metformin (50 mg/kg), tamoxifen citrate (4 mg/kg) with metformin (50 mg/kg), or estradiol (4 mg/kg) with metformin (50 mg/kg) for 3 days. Histological markers of uterotrophy, including luminal epithelial cell height and density of endometrial glands were quantified for each slide. Immunohistochemical expression of PCNA and S6K1 was evaluated. H-score was used for S6K1 expression. Statistical analysis was performed using Student's t-test for comparison of two continous variables and one-way ANOVA for comparison of multiple variables. RESULTS: Mice treated either with tamoxifen or estradiol had significantly increased density of endometrial glands and epithelial heights compared to vehicle-only or metformin-only group (p<0.001). Addition of metformin to tamoxifen or estradiol treated mice significantly decreased the density of endometrial glands and epithelial cell heights (p<0.05). Addition of metformin to tamoxifen significantly decreased the H-score of S6K1 (p<0.05) and the immunohistochemical expression of PCNA (p<0.05) in uterine lining epithelium, glandular and stromal cells. Addition of metformin to estradiol significantly decreased the H-score of S6K1 (p<0.05) and the immunohistochemical expression of PCNA (p<0.05) in uterine lining epithelium, glandular and stromal cells. CONCLUSION: Metformin seems to have possible antiproliferative effects on the endometrium of estradiol or tamoxifen treated mice via inhibiting the mTOR mediated S6K1 activation.

RAD001 (Everolimus) Can prevent tamoxifen-related endometrial and stromal hyperplasia.

The mechanism of tamoxifen-associated endometrial hyperplasia and cancer is not elicited. RAD001 inhibits a target protein in phosphatidyl kinase pathway, which is involved in endometrial hyperplasia and cancer. We investigated whether endometrial hyperplasia can be prevented through inhibition of the target of rapamycin by RAD001. Sixty BALB/c mice underwent oophorectomy and were divided into 6 groups: group 1, placebo group; group 2, tamoxifen-treated (4 mg/kg per 24 hours); group 3, estradiol-treated (4 mg/kg per 24 hours); group 4, RAD001-treated (1.5 mg/kg per 24 hours); group 5, tamoxifen (4 mg/kg per 24 hours)-and-RAD001 (1.5 mg/kg per 24 hours)-treated; and group 6, estradiol (4 mg/kg per 24 hours)-and-RAD001 (1.5 mg/kg per 24 hours)-treated. The count of glands, the length of epithelium, and immunohistochemical staining of proliferating cell nuclear antigen were analyzed. The count of total glands and the epithelial length were 30.8 (7.1) and 126 (43.4) microm, 53 (8.1) and 162.5 (34.8) microm, 65.2 (13.6) and 401.4 (44.0) microm, and 82.0 (5.2) and 444.7 (57.8) microm in the placebo-, the RAD001-, the tamoxifen-, and the estradiol-treated groups, respectively (P < 0.05). Although addition of RAD001 to estradiol did not decrease the count of total glands and the epithelial length, addition of RAD001 to tamoxifen did (43.3 [13.3] and 218.0 [29.2] microm, P < 0.05). The immunoreactive score of proliferating cell nuclear antigen is significantly decreased by the addition of RAD001 to either tamoxifen or estradiol in the epithelial and glandular cells. RAD001 can prevent tamoxifen-associated and estrogen-related endometrial hyperplasias in mice. RAD001 also decreases stromal cell proliferation in the tamoxifen-treated mice.

Retinal ganglion cell toxicity due to oxcarbazepine and valproic acid treatment in rat.

PURPOSE: To evaluate and to compare the possible toxic effects of oxcarbazepine (OXC) and valproic acid (VPA) on retinal ganglion cells (RGCs) in rat. METHODS: Forty female Wistar rats (21-24 days old and weighted between 44.6 and 57.3g) were divided equally into 4 experimental groups which were applied tap water (group 1), 300mg/(kgday) VPA (group 2), 100mg/(kgday) OXC (group 3), and both VPA and OXC (group 4) via gavage for 90 days. Enucleation was performed for histopathologic analysis. RGCs were counted under the light microscopic examination. RESULTS: RGC numbers in OXC and combined OXC-VPA groups were found to be lower than those of control group. On the other hand RGC number was comparable with those of control group in VPA group. CONCLUSION: OXC seems to be toxic to RGCs at 100mg/kg dose when it is been given as a monotherapy or combined with VPA. Single VPA treatment has no effect on RGC number.

Ciliary body toxicity of subconjunctival suramin compared with mitomycin-C in the rabbit eye: determining the toxic concentration.

BACKGROUND/AIMS: To evaluate the safety of suramin compared with mitomycin-C (MMC) as an adjunctive agent in trabeculectomy by determining its ciliary body toxicity at predetermined effective dosages in rabbit eyes. METHODS: Thirty-two New Zealand albino rabbits received either suramin (200, 300, 400, or 800 mg/ml) or MMC (0.2, 0.3, 0.4, or 0.8 mg/ml) injections subconjunctivally in the right eye. Enucleations were performed on the 1st, 3rd, 7th and 28th day. Untreated left eyes were injected with balanced salt solution and served as controls. The injection-exposed ciliary body specimens were processed to be investigated under the light microscope and transmission electron microscope. RESULTS: There was no pathologic abnormality in specimens under light microscopy. The morphologic evaluation with transmission electron microscopy showed severe changes in structure, except for eyes treated with 200 mg/ml suramin and 0.2 mg/ml of MMC. These changes were more prominent in eyes exposed to MMC, and appeared earlier compared to suramin-treated eyes. CONCLUSIONS: Suramin 200 mg/ml and MMC 0.2 mg/ml seem to be comparatively nontoxic to the ciliary body of the rabbit eye. Concentrations higher than these values caused severe damage.

Continuous or intermittent noise exposure, does it cause vestibular damage? An experimental study.

OBJECTIVE: Aim of this study was to compare vestibular changes in guinea pigs exposed to same level of continuous and intermittent noise by electron microscopy. METHODS: The study included 10 adult albino guinea pigs. In a silent room, a 4-kHz octave band noise at an intensity of 120 dB SPL was presented. Six animals were exposed to continuous noise for 6h, and four animals were exposed to 12h intermittent noise. One day after noise exposure eight guinea pigs were decapitated and temporal bones of one side were removed. Ten days after continuous noise exposure two guinea pigs were decapitated. They were examined with an electron microscope. RESULTS: The most characteristic changes in the macula of the continuous noise exposure group were degeneration of the epithelial cells and separation in their layers. Marked crystolysis and stromal cell apoptosis were also noted in this group compared to the intermittent noise exposure group. Effect of noise was more obvious in the group that continuous noise was applied. The histological changes in group which examined after 10 days were similar to the group that examined after 1 day. CONCLUSION: Continuous noise can cause more damage to the vestibular system compared with intermittent noise and histological changes after continuous noise are permanent.

Dose-dependent ultrastructural changes in rat cornea after oral methylphenidate administration.

OBJECTIVE: To investigate dose-dependent ultrastructural changes in rat cornea after oral methylphenidate Ritalin administration. METHODS: This study was conducted in the Department of Anatomy, Gazi University Faculty of Medicine, Ankara, Turkey between March and May 2005, with a total of 27 female prepubertal Wistar albino rats, divided into 3 different dose groups 5mg/kg, 10 mg/kg, 20 mg/kg, and their control groups. They were treated orally with methylphenidate, and eye tissue was removed to process for electron microscopic studies. RESULTS: We observed that all cells, and prominently basal cells of the corneal epithelium show dose-dependent degenerative changes such as apoptotic bodies, chromatin condensation, and ondulation in their nuclei and crystolysis of the mitochondrion. In the stroma, the most evident finding was the increase of the collagen fiber. In addition to dose-dependent changes related to the apoptotic process, which is chromatin condensation in their nuclei, electron dense material accumulation, and pericellular edema in the cytoplasm were also seen. In the endothelial cell lines, disruption of the junctional complexes, vacuolization in the cell cytoplasms, and crystolysis of the mitochondrion's with rough endoplasmic reticulum cisternae activity were observed. CONCLUSION: Ritalin is inducing an evident degeneration, especially in epithelium cells with increasing doses. Ultrastructural cell organelle composition degeneration with stromal fibrosis has a negative effect on cornea dehydration. In light of these findings, we believe that the Ritalin treatment doses need to be kept to a minimum to maintain healthy cornea ultrastructure and related physiology.

Ultrastructural damage in lung tissues in rats treated with doxorubicin and paclitaxel.

INTRODUCTION: The aim of this study was to determine the ultrastructural effects of doxorubicin (Adriblastina; Pharmacia and Upjohn, Milan, Italy), paclitaxel (Taxol; BMS, Princeton, NJ), Cremophor EL (a diluent of paclitaxel) and doxorubicin/paclitaxel combinations on normal lung tissues. METHODS: In the experimental protocol, 50 Wistar albino rats were used, divided into five different groups: the control group (n=10), the doxorubicin group (1 mg/kg) (n=10), the paclitaxel group (2 mg/kg) (n=10), the Cremophor EL group (150 mg/kg) (n=10) and the paclitaxel/doxorubicin group (2 mg/kg+ 1 mg/kg) (n=10). The drugs were administered weekly to rats via intraperitoneal injections for 14 weeks. After 3 weeks of observation, the rats were killed with thiopental sodium (30 mg/kg) and their left median lung tissues were removed and examined with a Carl Zeiss EM 900 transmission electron microscope. RESULTS: Our experiments showed doxorubicin to cause an increase in collagen fibre content of the alveolar wall, and paclitaxel to cause degenerations in cellular organelles. In the group in which the two agents were administered together, both effects were observed, although the effects of paclitaxel were seen to be dominant. Ultrastructural appearance was similar in the Cremophor EL group compared to the control group. CONCLUSION: It was detected that doxorubicin and paclitaxel caused ultrastructural degenerations in normal lung tissues and Cremophor EL seemed to be unaccountable for these degenerations.