Effect of tempol and tempol plus catalase on intra-renal haemodynamics in spontaneously hypertensive stroke-prone (SHSP) and Wistar rats

Vasoconstriction within the renal medulla contributes to the development of hypertension. This study investigated the role of reactive oxygen species (ROS) in regulating renal medullary and cortical blood perfusion (MBP and CBP respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar rats. CBP and MBP were measured using a laser-Doppler flow meter before and after intra-renal infusion of tempol, the superoxide dismutase (SOD) mimetic or tempol plus catalase, the hydrogen peroxide-degrading enzyme. Tempol infusion significantly elevated blood perfusion within the renal medulla (MBP) in both SHRSP (by 43 ± 7%, P < 0.001) and Wistar rats (by 17 ± 2%, P < 0.05) but the magnitude of the increase was significantly greater in the SHRSP (P < 0.01). When the enzyme catalase and tempol were co-infused, MBP was again significantly increased in SHRSP (by 57 ± 6%, P < 0.001) and Wistar rats (by 33 ± 6%, P < 0.001), with a significantly greater increase in perfusion being induced in the SHRSP relative to the Wistar rats (P < 0.01). Notably, this increase was significantly greater than in those animals infused with tempol alone (P < 0.01). These results suggest that ROS plays a proportionally greater role in reducing renal vascular compliance, particularly within the renal medulla, in normotensive and hypertensive animals, with effects being greater in the hypertensive animals. This supports the hypothesis that SHRSP renal vasculature might be subjected to elevated level of oxidative stress relative to normotensive animals.     

Practice with confidence: Analyzing confidence level of final year dental students from four Saudi dental colleges in Riyadh

ObjectiveTo investigate the confidence level of final year dental students in Riyadh.MaterialsCross-sectional study was conducted at four dental colleges in Riyadh (N = 312, 220 and 70,5% responded). Oneway ANOVA and post hoc Tukey-Kramer was used.ResultsThe greatest self-reported confidence scores were for pit fissure sealent (4.6(0.7)). Whereas, students reported least confidence in conducting surgical extractions (2.7 (1.2)). Females were found more confident in conducting preventive resin restorations, oral hygiene instructions, and rubber dam placement as compared to male who were more confident in surgical extraction, copy dentures, veneer preparation and managing orthodontic emergencies.ConclusionAll students were confident in performing essential dental procedures however higher confidence was observed in performing simple procedures compared to more complex ones.