In vitro viability of choroidal melanomata following pre-enucleation irradiation

In a group of eighteen patients with uveal melanomas, seven underwent low-dose pre-enucleation irradiation of approximately 2000 cGy. All the tumours were propagated in tissue culture and the growth characteristics of tumour cells from irradiated eyes were compared with tumour cells from non-irradiated eyes. Cultures were observed with phase-contrast microscopy, and radioactive thymidine labelling was used to study cell turnover. Although tissue samples from peripheral areas of irradiated tumours produced a mixture of viable and non-viable cells, with reduced ability to attach to substrate, central regions of irradiated tumours contained viable cells which propagated freely in tissue culture.

REACTIVE OXYGEN SPECIES AND THE STRUCTURAL REMODELING OF THE VISUAL SYSTEM AFTER OCULAR ENUCLEATION

Redox processes associated with controlled generation of reactive oxygen species (ROS) by NADPH oxidase (Nox) add an essential level of regulation to signaling pathways underlying physiological processes. We evaluated the ROS generation in the main visual relays of the mammalian brain, namely the superior colliculus (SC) and the dorsal lateral geniculate nucleus (DLG), after ocular enucleation in adult rats. Dihydroethidium (DHE) oxidation revealed increased ROS generation in SC and DLG between 1 and 30 days postlesion. ROS generation was decreased by the Nox inhibitors diphenyleneiodonium chloride (DPI) and apocynin. Real-time PCR results revealed that Nox 2 was upregulated in both retinorecipient structures after deafferentation, whereas Nox 1 and Nox 4 were upregulated only in the SC. To evaluate the role of ROS in structural remodeling after the lesions, apocynin was given to enucleated rats and immunohistochemistry was conducted for markers of neuronal remodeling into SC and DLG. Immunohistochemical data showed that ocular enucleation produces an increase of neurofilament and microtubule-associated protein-2 immunostaining in both SC and DLG, which was markedly attenuated by apocynin treatment. Taken together, the findings of the present study suggest a novel role for Nox-induced ROS signaling in mediating neuronal remodeling in visual areas after ocular enucleation. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Demecolcine Effects on Microtubule Kinetics and on Chemically Assisted Enucleation of Bovine Oocytes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chemically Assisted Enucleation Results in Higher G6PD Expression in Early Bovine Female Embryos Obtained by Somatic Cell Nuclear Transfer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Five years follow-up of a keratocyst odontogenic tumor treated by marsupialization and enucleation: a case report and literature review

Odontogenic cysts are considered as nonneoplasic benign lesions. Among the cysts, keratocyst odontogenic tumor (KCOT) is an intra‑osseous tumor characterized by parakeratinized stratified squamous epithelium and a potential for aggressive, infiltrative behavior, and for the possibility to develop carcinomas in the lesion wall. Thus, the aim of this study was to describe a clinical case of KCOT in a young patient and discuss the treatment alternatives to solve this case. A 15‑year‑old male was referred for treatment of a giant lesion in his left side of the mandible. After the biopsy, a diagnostic of KCOT was made, and the following procedures were planned for KCOT treatment. Marsupialization was performed for lesion decompression and consequent lesion size reduction. Afterward, enucleation for complete KCOT removal was performed followed by third mandibular molar extraction. After 5 years, no signs of recurrence were observed. The treatment proposed was efficient in removing the KCOT with minimal surgical morbidity and optimal healing process, and the first and second mandibular molars were preserved with pulp vitality. In conclusion, this treatment protocol was an effective and conservative approach for the management of the KCOT, enabling the reduction of the initial lesion, the preservation of anatomical structures and teeth, allowing quicker return to function. No signs of recurrence after 5 years were observed.

Double-setting alpha-tricalcium phosphate cement provided with interconection channels in rabbits after enucleation: a potential implant for the anophthalmic socket

The purpose of this study was to evaluate the macroscopy and microstructure of a double setting alpha-tricalcium phosphate bone cement sphere provided with interconnection channels (alpha-TCP-i), as well as the integration of the implant with the rabbits' orbital tissue, through macroscopic analysis and histopathology. The external and internal surfaces of the alpha-TCP-i were evaluated macroscopically and by electron microscopy. Twelve New Zealand rabbits received 12mm implants of alpha-TCP-i following enucleation of the left eye. The clinical assessment was undertaken daily during the first 15 days, followed by fortnightly assessment until the end of the study period. For the morphological analysis, exenteration was performed in 3 animals per experimental period (15, 45, 90 and 180 days). The external and internal surfaces of the implant appeared solid, smooth and compact, with six channels which interconnected centrally. The micro-architecture was characterized by the formation of columns of hexagonal crystals. No signs of infection, exposure, dehiscence of sutures or extrusion of the implant were noted in any of the animals during the entire period of the study. The morphological evaluation demonstrated the presence of a thin capsule around the implant, from whence appeared fibro-vascular projections, which penetrated it through the interconnecting channels. In the first days after the insertion of the implant, an intense inflammatory reaction was noted. At 180 days, however, there were no signs of inflammation. The alpha-tricalcium phosphate cement implant was well tolerated in this rabbit model and appeared to be relatively inert with some fibrovascular ingrowth through the large channels.

Eye enucleation activates the transcription nuclear factor kappa-B in the rat superior colliculus

Ocular enucleation produces significant morphological and physiological changes in central visual areas. However, our knowledge of the molecular events resulting from eye enucleation in visual brain areas remains elusive. We characterized here the transcription nuclear factor kappa-B (NF-kappa B) activation induced by ocular enucleation in the rat superior colliculus (SC). We also tested the effectiveness of the synthetic glucocorticoid dexamethasone in inhibiting its activation. Electrophoretic mobility shift assays to detect NF-kappa B indicated that this transcription factor is activated in the SC from 1 h to day 15 postlesion. The expression of p65 and p50 proteins in the nuclear extracts was also increased. Dexamethasone treatment was able to significantly inhibit NF-kappa B activation. These findings suggest that this transcriptional factor is importantly involved in the visual system short-term processes that ensue after retinal lesions in the adult brain. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Inflammatory responses in the rat superior colliculus after eye enucleation

Ocular enucleation induces profound morphological alterations in central visual areas. However, little is known about the response of glial cells and possible inflammatory processes in visual brain areas resulting from eye enucleation. In this study, immunoblotting and immunostaining assays revealed increased expression of astrocyte and microglia markers in the rat superior colliculus (SC) between 1 and 15 days after contralateral enucleation. A transient increase of neuronal COX-2 protein expression was also found in the SC. To evaluate the role of an anti-inflammatory drug in attenuating both COX-2 and glial cell activation, the synthetic glucocorticoid dexamethasone (DEX) was administered (1mg/kg i.p., for 3 days) to enucleated rats. Immunoblotting data revealed that DEX treatment significantly inhibited COX-2 protein expression. Postlesion immunostaining for astrocyte and microglia markers was also significantly reduced by DEX treatment. These findings suggest that the removal of retinal ganglion cell input generates inflammatory responses in central retinorecipient structures

Prenatal monocular enucleation induces a selective loss of low-spatial-frequency cortical responses to the remaining eye.

During early development, interactions between the two eyes are critical in the formation of eye-specific domains within the lateral geniculate nucleus and the visual cortex. When monocular enucleation is done early in prenatal life, it induces remarkable anatomical and functional reorganizations of the visual pathways. Behavioral data have shown a loss in sensitivity to low-spatial-frequency gratings in cats. To correlate the behavioral observations with a possible change in the analysis of contrast at the level of primary visual areas we recorded visual evoked potentials at the 17/18 border in two cats enucleated prenatally (gestational age at enucleation, 39-42 days), three neonatal, two control animals, and one animal with a surgical removal of Y-ganglion fibers. Our results show a strong attenuation in the amplitude of response at all contrast values for gratings of low spatial frequency in prenatally enucleated cats, whereas neonatally enucleated and control animals present responses of comparable amplitude. We conclude that the behavioral results reflect the reduced sensitivity for low frequencies of visual cortical neurons. In addition, we define a critical period for the development of the contrast-sensitivity function that seems to be limited to the prenatal gestation period. We suggest that the prenatal interruption of binocular interactions leads to a functional elimination of the Y-ganglion system.

Factors Affecting De Novo Urinary Retention after Holmium Laser Enucleation of the Prostate

Objective Patients can experience urinary retention (UR) after Holmium laser enucleation of the prostate (HoLEP) that requires bladder distension during the procedure. The aim of this retrospective study is to identify factors affecting the UR after HoLEP. Materials and Methods 336 patients, which underwent HoLEP for a symptomatic benign prostatic hyperplasia between July 2008 and March 2012, were included in this study. Urethral catheters were routinely removed one or two days after surgery. UR was defined as the need for an indwelling catheter placement following a failure to void after catheter removal. Demographic and clinical parameters were compared between the UR (n = 37) and the non-urinary retention (non-UR; n = 299) groups. Results The mean age of patients was 68.3 (±6.5) years and the mean operative time was 75.3 (±37.4) min. Thirty seven patients (11.0%) experienced a postoperative UR. UR patients voided catheter free an average of 1.9 (±1.7) days after UR. With regard to the causes of UR, 24 (7.1%) and 13 (3.9%) patients experienced a blood clot-related UR and a non-clot related UR respectively. Using multivariate analysis (p<0.05), we found significant differences between the UR and the non-UR groups with regard to a morcellation efficiency (OR 0.701, 95% CI 0.498–0.988) and a bleeding-related complication, such as, a reoperation for bleeding (OR 0.039, 95% CI 0.004–0.383) or a transfusion (OR 0.144, 95% CI 0.027–0.877). Age, history of diabetes, prostate volume, pre-operative post-void residual, bladder contractility index, learning curve, and operative time were not significantly associated with the UR (p>0.05). Conclusions De novo UR after HoLEP was found to be self-limited and it was not related to learning curve, patient age, diabetes, or operative time. Efficient morcellation and careful control of bleeding, which reduces clot formation, decrease the risk of UR after HoLEP.