The role of reactive oxygen species (ROS) in bladder cancer progression remains an unexplored field. Expression levels of enzymes regulating ROS levels are often altered in cancer. Search of publicly available micro-array data reveals that expression of mitochondrial manganese superoxide dismutase (Sod2), responsible for the conversion of superoxide (O 2 -. ) to hydrogen peroxide (H 2 O 2 ), is consistently increased in high grade and advanced stage bladder tumors. Here we aim to identify the role of Sod2 expression and ROS in bladder cancer. Using an in vitro human bladder tumor model we monitored the redox state of both non-metastatic (253J) and highly metastatic (253J B-V) bladder tumor cell lines. 253J B-V cells displayed significantly higher Sod2 protein and activity levels compared to their parental 253J cell line. The increase in Sod2 expression was accompanied by a significant decrease in catalase activity, resulting in a net increase in H 2 O 2 production in the 253J B-V line. Expression of pro-metastatic and -angiogenic factors, matrix metalloproteinase 9 (MMP-9) and vascular endothelial derived growth factor (VEGF), respectively, were similarly upregulated in the metastatic line. Expression of both MMP-9 and VEGF were shown to be H 2 O 2 -dependent, as removal of H 2 O 2 by overexpression of catalase attenuated their expression. Similarly, expression of catalase effectively reduced the clonogenic activity of 253J B-V cells. These findings indicate that metastatic bladder cancer cells display an altered antioxidant expression profile, resulting in a net increase in ROS production, which leads to the induction of redox-sensitive protumorigenic and pro-metastatic genes such as VEGF and MMP-9.
The anti-inflammatory effect, visual recovery, and IOP of patients using topical difluprednate or loteprednol gel after cataract surgery are equivalent. There may be an additional short-term benefit of loteprednol gel in protecting the ocular surface after cataract surgery.
There have been various modifications in traditional evisceration technique to provide better cosmetic and functional outcome to the patient. Smith et al. 1 retrospectively reviewed the 201 cases which had undergone evisceration by the "2 scleral flaps" technique. They concluded that this technique is a simple, safe, and useful procedure that enables the placement of adequately sized implants. However, their study lacks a few important things. First, the authors have not adequately analyzed the motility of the implant and prosthesis. Though all patients were pleased with their cosmetic result after prosthesis fitting, the objective assessment of motility was not carried out. Moreover, postoperative motility depends upon various factors depending upon each case. For example, cases with trauma and retinal detachment (with scleral buckling) may not have adequate preoperative motility, and these accounted for the majority of cases (130 out of 201 cases) in the study. We believe that postoperative motility in such cases may not be adequate when compared to other cases.Secondly, the "2 scleral flaps" technique involves sclerotomy from the limbus to the optic nerve in 2 quadrants, after which flaps are released from the optic nerve. This would cause more disturbances of the orbital tissue, suspensory ligament, and physiologic dynamics of muscle. We know that the rectus muscles pass through the connective tissue sleeves or pulleys, located close to the equator of the globe, which stabilizes the position of the recti relative to the orbit during eye movements. These pulleys are dependent upon the intermuscular septum and Tenon's fascia for their support and are believed to be the functional origin of the muscle. So when scleral flaps are made, damage to this important structure is bound to occur, especially in trauma and retinal detachment, where they are already compromised. This is also reflected in the present study by Smith et al. 1 , who noted the implant exposure in 3 cases, out of which 2 occurred in cases with etiology of severe trauma.Third, separation of the scleral flaps from the optic nerve is a further disadvantage because nerve will retract posteriorly, and thereby, the central retinal artery cannot aid in fibrovascular growth in the implant. Moreover, an open scleral cavity posteriorly can cause implant migration out of the central space. We also believe that though the separation of scleral flaps from the optic nerve reduces the tension on sclera anteriorly, it could possibly exert more tension on the conjunctiva and Tenon's fascia. This is because the optic nerve in addition to the recti would prevent the anterior movement of the implant and sclera.In the scleral quadrisection technique described by Yang et al. 2 and Sales-Sanz and Sanz-Lopez, 3 the implant is covered anteriorly by 2 layers of sclera. Thus, chances of exposure are minimized. The evisceration by the 2 scleral flaps technique does not provide this advantage.The evisceration technique should be performed so as to minimally disturb the orbita...
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