Yusuf Nergiz

Effects of soft contact lenses on conjunctival surface.

Purpose To examine the effects of soft contact lenses on tear breakup time (TBUT), basal Schirmer test result, and the conjunctival surface in patients wearing contact lenses. Methods In this study, conjunctival cytologic changes, TBUT, and Schirmer test function alterations of soft contact lens wearers were evaluated by impression cytology. The study included 100 eyes of 50 soft contact lens wearers who were followed up in the Department of Ophthalmology of Dicle University and 80 eyes of 40 subjects as a control group. After TBUT and basal Schirmer test, conjunctival surface epithelial morphology was investigated using impression cytology. After the materials were appropriately stained, they were evaluated according to the Nelson grading scale. Results Contact lens wearers were divided into three groups according to the duration of contact lens wear. When these groups were evaluated according to the Nelson grading method, 21% of cases were grade 0; 32% were grade 1; and 28% were grade 3. There were statistically significant differences in epithelial cell morphology, goblet cell density, snakelike chromatin changes, TBUT, and basal Schirmer test result between the control and study groups. Conclusions We suggest that TBUT and Schirmer test result be carefully monitored in contact lens wearers. Impression cytology may be used as a safe, simple, and noninvasive method in the diagnosis of ocular surface alternations in patients with contact lens intolerance.

Intracellular Ca2+ levels in rat ventricle cells exposed to extremely low frequency magnetic field

Objective: Electromagnetic fields can affect intracellular Ca2+ levels. The aim of this study was to determine the changes intracellular Ca2+ concentration in cardiac ventricle cells of rats exposed to 0.25 mT (2.5 Gauss) magnetic field. Methods: Forty-five male rats were introduced to this study. The rats were divided into three groups: control, sham, and experiment. The experimental group was exposed to 0.25 mT extremely low frequency (ELF) magnetic field for 14 days, 3 h/day. The sham group was treated like the experimental group, except for elf-magnetic field exposure. The control group was not subjected to anything and differed from the experimental group and sham group. In the end of experiment, rats were sacrificed, cardiac tissue was removed, and these were fixed in 10% neutral formalin. Then, ventricular cells were stained by Alizarin red staining method. Results: In the light microscopic examinations of control groups, in myofibril structures between groups, changes were not observed. In myofibril regions of the experimental group compared to other groups, increased heterogen Ca2+ accumulations were found. Conclusion: ELF magnetic fields are used in daily life. The results of this study show that intracellular Ca2+ accumulation in cardiac ventricles can increase in rats exposed to ELF magnetic field.

Impression cytology, tear film break up, and Schirmer test in patients with inactive trachoma.

Schirmer I and tear film break up time (BUT) test were used to determine cytological changes and conjunctival surface epithelial morphology was investigated using impression cytology in patients with inactive trachoma; patients with mild and severe scarring, and control subjects, were compared. Schirmer I, BUT, and goblet cell populations were significantly lower whereas the grade of squamous metaplasia was significantly higher in patients with inactive trachoma. There was a close correlation between our findings and the clinical severity of trachoma.

Potentiation of cisplatin-induced nephrotoxicity in rats by allopurinol.

Cisplatin (CDDP) is an effective chemotherapeutic agent used against various human malignancies. However, it induces nephrotoxicity, a severe side effect in which oxygen free radicals have been implicated to play an important role. The effect of allopurinol (Allp) given in a dose of 50 mg/kg subcutaneously (s.c.) for five days was examined on induced nephrotoxicity by a single dose of 5 mg/kg CDDP intraperitoneally (i.p.) in male wistar rats. Serum creatinine and blood urea nitrogen (BUN) concentrations were found significantly higher in the group given both Allp and CDDP than in the group given CDDP alone, p < 0.001, and histopathological examination showed more excessive degree of proximal tubular necrosis in the kidneys of animals given CDDP plus Allp than in those treated with CDDP alone. Increased renal lipid peroxidation, p < 0.001 associated with these pathological alterations suggested that oxidative stress may be involved in the potentiation of CDDP-induced nephrotoxicity by Allp.

The Effects of Electromagnetic Fields on the Ultrastructure of Heart

El uso y la comodidad de los aparatos electricos en nuestra vida cotidiana cada vez mas son causa de efectos perjudiciales debido a los campos electromagneticos(CEM).El objetivo de este estudio fue investigar el efecto de los CEM sobre la ultraestructura del corazon en ratas. Fueron utilizadas 45ratas Sprague Daw ley, con peso entre 260 y 280gramos. Las ratas fueron divididas en 3 grupos: control (n: 15); Sham (n:15), y grupo expuesto a CEM (n:15) durante 14 dias,3 horas por dia. Se aplico niveles de 2,5gaussal grupo expuesto a CEM, mientras que el grupo de tratamiento simulado en el mismo entorno en jaulas plexiglas se mantuvo durante14 dias3 horas dia, sin exposicion a campo electromagnetico. Grupo control alimentado en jaulas normales durante 14 dias con ciclo luz/oscuridad de 14/10.Al termino de dos semanas las ratas fueron sacrificadas por medio de anestesia Ketalar 50mg/kg y el tejido del corazon fijado engluteraldehido al 2,5. Se realizo seguimiento de rutina con correspondiente evaluacion de microscopia electronica. Las estructuras mitocondriales y celular es observadas en todos los grupos eran normales. No se observo perdida miofibrilar, tampoco aumento del volumen mitocondrial ni dilatacion del reticulo endoplasmico lisoocristalysis. No se observo degeneracion de los discosintercaladoso apoptosis de nucleo. Por lo tanto,y como resultado de nuestro estudio no encontramos diferencias entre los grupos control y CEM.

The effects of intracameral ropivacaine on the corneal endothelium.

Topical and intracameral anesthesia have been popularized as new techniques for use in cataract surgery, and these anesthetic routes have potential safety advantages over traditional techniques such as retrobulbar and peribulbar anesthesia. Intracameral techniques have included the use of preservative-free (PF) lidocaine hydrochloride 1% or PF bupivacaine hydrochloride 0.5%. Ropivacaine is a long-acting local anesthetic agent that has a greater margin of safety regarding cardiac and central nervous system toxicity than bupivacaine. Although ropivacaine has started to be used in topical anesthesia, it has not yet been used in intracameral anesthesia. Martini et al. reported that topical ropivacaine 1% performed at least as well as lidocaine 4% in cataract surgery. Moreover, it resulted in better subjective pain scores. Ropivacaine takes longer to become completely effective; however, it provides a longer postoperative analgesic effect.Although the higher incidence of corneal edema with ropivacaine may be a concern, the edema resolves rapidly and the medium-term endothelial data indicate that ropivacaine is safe for the endothelium. Therefore, ropivacaine seems to be a good alternative to lidocaine for topical use in cataract surgery. There is concern about the efficacy and safety of this procedure, particularly toxicity to the corneal endothelium. Animal studies are helpful in indicating potential toxicity, but application and relevance to human in vivo conditions is limited. No studies in the literature have investigated the effects of ropivacaine on ocular tissues. We carried out experimental studies on the effects of intracameral irrigation of ropivacaine on the corneal endothelial ultrastructure using transmission electron microscropy (TEM).

Protective effects of ethyl pyruvate in cisplatin-induced nephrotoxicity

This study was performed to investigate the effect of ethyl pyruvate on changes in renal functions and oxidative stress related renal injury caused by cisplatin (cis-dichlorodiammine platinum-II; CDDP). Male Wistar albino rats were divided into four groups (n = 8): (1) control group (1 ml Ringers lactate solution i.p.); (2) ethyl pyruvate (EP) group (50 mg/kg Ringers EP solution (REPS) i.p.); (3) cisplatin group (a single dose of cisplatin (5 mg/kg, i.p.); and (4) cisplatin + EP group (a single dose of cisplatin (5 mg/kg, i.p.) + REPS 50 mg/kg/day, i.p.) for five days. At the sixth day, kidneys of rats were mounted to a Langendorff apparatus. Renal perfusion pressures were recorded. Blood samples were taken for serum urea, creatinine, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stres index (OSI) evaluations. Kidney tissues were obtained for malondialdehyde (MDA) analyses and histopathological examination. Perfusion pressures, serum urea, creatinine, TOS, OSI and tissue MDA levels were found significantly higher, whereas TAS was notably lower in cisplatin group. Histopathological examination showed apparent renal paranchymal injury in cisplatin group. In cisplatin + REPS group, perfusion pressures, serum urea, creatinine and tissue MDA levels were decreased. Moreover, EP co-administration provided less inflammatory cell infiltration, tubular dilatation, whereas TOS, TAS and OSI improved significantly versus cisplatin group. These findings show that EP has protective effects against cisplatin nephrotoxicity.

Effects of hyperbaric oxygen on crystalline lens and retina in nicotine-exposed rats.

Objective: To determine histopathological changes on crystalline lens and retina of rats after subcutaneous injection of nicotine and to examine the effects of hyperbaric oxygen (HBO) on these changes related to nicotine exposure. Methods: Twenty-eight female Sprague-Dawley rats were enrolled in the study and the rats were divided into four equal sized groups randomly (Group N: the rats exposed only to nicotine, group HB: the rats received only HBO, group N+HB: the rats that underwent to nicotine injection and subsequently received HBO, group C: the control group that neither exposed to nicotine nor received HBO). The rats were sacrified by decapitation method and all were enucleated immediately after scarification. Tissue samples from crystalline lens, lens capsule, and the retina from the right eyes of the rats were examined by light microscopy. Results: While the histological appearances of the retina and the lens was similar in group HB, group N+HB, and the control group; group N showed some pathological changes like decrement in the retinal ganglion cell density, atrophy of the retinal nerve fiber layer, congestion of the vessels in the optic nerve head, thinning of the internal plexiform layer, thinning of the lens capsule, and transformation of the anterior subcapsular epithelium into squamous epithelia. Discussion: Subcutaneous injection of nicotine was found to be related with some pathological changes in the retina and lens of the Sprague-Dawley rats. However HBO caused no significant negative effect. Furthermore, the histopathological changes related to nicotine exposure in the lens and retina of the rats recovered by the application of HBO.

Protective Effects of Melatonin on Testicular Torsion and Detorsion Damage in Sprague-Dawley Rats

Se evaluaron, en un modelo de torsion/detorsion (T/D) testicular en rata, los cambios ultraestructurales producidos en los testiculos, posterior a la administracion sistemica de diferentes dosis de melatonina, durante el periodo de isquemia. La lesion de isquemia-reperfusion (I/R) testicular fue inducida por la torsion del testiculo izquierdo, con un giro de 720 grados del cordon espermatico con el fin de producir una oclusion total de los testiculos durante 2,5 horas. Posteriormente, los mismos testiculos fueron detorsionados. De acuerdo con el procedimiento quirurgico en cada grupo, fueron realizados examenes histopatologicos de las orquiectomias unilaterales. Los grupos fueron divididos en grupo control, grupo torsion (T), grupo torsion/destorsion (T/D), y grupo torcion/destorsion con melatonina (T/D +20, 50 y 100 mg/kg de la melatonina). Para el examen histologico, los tejidos testiculares fueron fijados en soluciones de glutaraldehido al 2,5% y postfijados al 1% en acido osmico. Luego fueron examinados, despues de la aplicacion de contrastes de colores, a traves de microscopia electronica de transmision. En las secciones transversales del grupo con torsion testicular, fueron visibles residuos citoplas-maticos de espermatozoides maduros y grandes estructuras vacuolares. En las secciones transversales del grupo con destorsion testicular, se observaron disociaciones en los nucleos espermaticos, numerosas vacuolas y particulas residuales derivadas de la degeneracion de organelos; ademas de espacios localizados en el citoplasma de las espermatogonias, dilatacion en el reticulo endoplasmatico rugoso, grandes gotas de lipidos y particulas de cromatidas, junto con cristalisis mitocondrial. En las secciones transversales del grupo T/D +50 mg/kg de administracion de melatonina, celulas sustentaculares y espermatogonias mostraron estructuras tipo membrana y vacios citoplasmaticos. Las secciones transversales del grupo con torsion en las que fue administrado 50 mg/kg de melatonina mostraron mitocondrias pequenas y estructuras como vacuolas ubicadas en el borde. Las secciones transversales testiculares de las ratas en las que fue administrado 100 mg/kg de melatonina, se observaron caracteristicas similares a los controles a nivel microestructural. Como resultado, la dosis mas eficaz de melatonina utilizada para la prevencion del dano por isquemia-reperfusion (I/R) fue de 100 mg/kg.

Effects of trypan blue on corneal endothelium and anterior lens capsule in albino wistar rats: An investigator-masked, controlled, two-period, experimental study.

BACKGROUND The development of continuous curvilinear capsulorrhexis (CCC) has contributed significantly to the tolerability and effectiveness of cataract extraction and intraocular lens implantation. Staining of the anterior capsule has become a popular method of increasing visibility when performing CCC. OBJECTIVE The aim of this study was to determine, using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the highest concentrations of trypan blue dye that would not cause long-term toxicity after injection into the anterior chamber of rat eyes. METHODS The eyes of healthy female albino Wistar rats were used in this investigator-masked, controlled, 2-period, experimental study conducted over 12 weeks at the Dicle University Experimental Animal Laboratory, Diyarbakir, Turkey. The rats were randomly divided into 5 groups of 4 using a random-number table. Each rat was administered a 0.05-mL injection of trypan blue into the right eye in 1 of the following concentrations: 0.4%, 0.2%, 0.1%, 0.05%, or 0.025%. A 0.05-mL pH-balanced saline solution was injected into the left eye of each rat to act as a control. At 1 day after injection and 4 weeks after injection (early period), 1 rat from each concentration group was euthanized and their eyes were enucleated. At 12 weeks after injection (late period) the remaining 2 rats from each group were euthanized and their eyes were enucleated. Corneal endothelial cells and the anterior lens capsule of the enucleated eyes were analyzed using SEM and TEM, and the results were compared with those of the control group. In the TEM analysis, the primary end point was the histopathologic changes in the cellular organelles when compared with those in the control group. In the SEM analysis, the primary end point was changes in cell shape, intracellular junctions, and density of the microvilli when compared with those in the control group. RESULTS Forty eyes from 20 albino Wistar rats (mean [SD] age, 8.2 [1.6] weeks; mean [SD] weight, 175.6 [16.5] g) were used in the study. Each group of rats received a different concentration of trypan blue in the right eye. In the early period, both the 0.4% and 0.2% concentrations were associated with the impairment of the hexagonal structure of corneal endothelial cells and intercellular junctions. Those concentrations were also associated with an increased occurrence of cellular vacuolation, cytoplasmic edema, extensive granulation of the endoplasmic reticulum, pyknotic nuclei, and mitochondrial degeneration. In the late period, these changes were observed as persisting in a decreasing manner. With the 0.1% and 0.05% concentrations, the density of microvilli decreased, nuclei appeared normal, granulation of the endoplasmic reticulum and Golgi apparatus was active, and minimal levels of mitochondrial degeneration were observed. CONCLUSIONS In this small experimental study in rat eyes, trypan blue at concentrations >0.025% was associated with impaired morphology and structure of corneal endothelial cells after short-term exposure. This effect continued in a decreasing fashion after long-term exposure. No significant changes were noted in the control group or the group administered the 0.025% concentration.