Effects of p67phox on the mitochondrial oxidative state in the kidney of Dahl salt-sensitive rats: optical fluorescence 3-D cryoimaging.

The goal of the present study was to quantify and correlate the contribution of the cytosolic p67(phox) subunit of NADPH oxidase 2 to mitochondrial oxidative stress in the kidneys of the Dahl salt-sensitive (SS) hypertensive rat. Whole kidney redox states were uniquely assessed using a custom-designed optical fluorescence three-dimensional cryoimager to acquire multichannel signals of the intrinsic fluorophores NADH and FAD. SS rats were compared with SS rats in which the cytosolic subunit p67(phox) was rendered functionally inactive by zinc finger nuclease mutation of the gene (SS(p67phox)-null rats). Kidneys of SS rats fed a 0.4% NaCl diet exhibited significantly (P = 0.023) lower tissue redox ratio (NADH/FAD; 1.42 ± 0.06, n = 5) than SS(p67phox)-null rats (1.64 ± 0.07, n = 5), indicating reduced levels of mitochondrial electron transport chain metabolic activity and enhanced oxidative stress in SS rats. When fed a 4.0% salt diet for 21 days, both strains exhibited significantly lower tissue redox ratios (P < 0.001; SS rats: 1.03 ± 0.05, n = 9, vs. SS(p67phox)-null rats: 1.46 ± 0.04, n = 7) than when fed a 0.4% salt, but the ratio was still significantly higher in SS(p67phox) rats at the same salt level as SS rats. These results are consistent with results from previous studies that found elevated medullary interstitial fluid concentrations of superoxide and H2O2 in the medulla of SS rats. We conclude that the p67(phox) subunit of NADPH oxidase 2 plays an important role in the excess production of ROS from mitochondria in the renal medulla of the SS rat.

A rare case of intramedullary cervical spinal cord meningioma and review of the literature.

STUDY DESIGN: Case report. SETTINGS: Department of Neurosurgery, Imam Hospital, Faculty of Medicine, Tabriz University of Medical Sciences, Daneshgah Street, Tabriz, East Azerbayjan, Iran. REPORT: A 21-year-old man presented with progressive paraesthesia and weakness in the four limbs, with disturbances in the vibration and positional senses. Magnetic resonance imaging revealed a cervical intramedullary tumour from the cervicomedullary junction to C3. Radical resection of the tumour was performed and histology revealed a meningioma. His clinical outcome after a 3-year follow-up is relatively good. CONCLUSION: Intramedullary cervical meningiomas are very rare and have been reported only five times before. Because of its tendency to recur after surgery and because of a possible aggressive behaviour, meticulous histopathological examination is mandatory to predict the evolution and plan the follow-up. Outcome is mainly related to the type of tumour and the complete removal.