Activation of the cannabinoid receptor 2 increases renal perfusion.

Acute kidney injury (AKI) is an increasing clinical problem that is associated with chronic kidney disease progression. Cannabinoid receptor 2 (CB2) activation has been shown to mitigate some of the deleterious tubular effects due to AKI, but its role on the renal vasculature has not been fully described. In this study, we investigated the effects of our novel CB2 receptor agonist, SMM-295, on renal vasculature by assessing cortical perfusion with laser Doppler flowmetry and changes in luminal diameter with isolated afferent arterioles. In this study, intravenously infused SMM-295 (6 mg/kg) significantly increased cortical renal perfusion (13.8 ± 0.6%; P < 0.0001; n = 7) compared with vehicle (0.1 ± 1.5%; n = 10) normalized to baseline values in anesthetized C57BL/6J mice. This effect was not dependent upon activation of the CB1 receptor (met-anandamide; 6 mg/kg iv) and was predominantly abolished in Cnr2 knockout mice with SMM-295 (6 mg/kg iv). Ablation of the renal afferent nerves with capsaicin blocked the SMM-295-dependent increase in renal cortical perfusion, and the increased renal blood flow was not dependent upon products synthesized by cyclooxygenase or nitric oxide synthase. The increased renal perfusion by CB2 receptor activation is also attributed to a direct vascular effect, since SMM-295 (5 µM) engendered a significant 37 ± 7% increase ( P < 0.0001; n = 4) in luminal diameters of norepinephrine-preconstricted afferent arterioles. These data provide new insight into the potential benefit of SMM-295 by activating vascular and nonvascular CB2 receptors to promote renal vasodilation, and provide a new therapeutic target to treat renal injuries that impact renal blood flow dynamics.

A comparative clinical study of various methods of caries removal in children.

AIM: The aim of the study was to compare the efficacy of caries removal, time taken and to evaluate the pain threshold experienced by children during various caries removal methods. METHODS: One hundred and twenty patients aged between 4 and 14 years requiring dental restorations were selected. Caries removal was completed using an air-rotor, hand instruments, Carisolv and polymer burs. The efficacy, time taken and pain thresholds were evaluated during caries removal by Ericsson et al. scale, visual analogue scale and verbal pain scale, respectively. STATISTICAL ANALYSIS: Data was collected and statistically analysed using one-way analysis of variance followed by Post Hoc comparison by Bonferroni method. The skewed data was analysed amongst groups by applying Kruskal-Wallis test followed by probability adjustment by Mann-Whitney test. RESULT: These results indicated that the efficacy of caries removal was highest with air-rotor and was least by the hand instrument, whilst Carisolv® was least painful and the most time-consuming method. CONCLUSIONS: Caries removal with polymer burs and Carisolv were found to be as effective in caries removal and could be considered as alternatives to painful procedures as air-rotor in management of caries especially in children.

Mechanism(s) Involved in Carbon Monoxide-releasing Molecule-2-mediated Cardioprotection During Ischaemia-reperfusion Injury in Isolated Rat Heart.

The purpose of the present study was to determine the mechanism(s) involved in carbon monoxide-releasing molecule-2, carbon monoxide-releasing molecule-2-induced cardioprotection. We used the transition metal carbonyl compound carbon monoxide-releasing molecule-2 that can act as carbon monoxide donor in cardiac ischaemia-reperfusion injury model using isolated rat heart preparation. Langendorff's perfused rat hearts when treated with carbon monoxide-releasing molecule-2 (50 µM) for 10 min before global ischaemia exhibited significant reduction in postischaemic levels of myocardial injury markers, creatine kinase and lactate dehydrogenase in coronary effluent. Similarly, pretreatment with carbon monoxide-releasing molecule-2 showed significantly improved postischaemic recovery of heart rate, coronary flow rate, cardiodynamic parameters and reduced infarct size as compared to vehicle control hearts. Perfusion with p38 mitogen-activated protein kinase inhibitor, SB203580, a specific inhibitor of α and ß isoform, before and concomitantly with carbon monoxide-releasing molecule-2 treatment abolished carbon monoxide-releasing molecule-2-induced cardioprotection. However, p38 mitogen-activated protein kinase alpha inhibitor, SCIO-469, was unable to inhibit the cardioprotective effect of carbon monoxide-releasing molecule-2. Furthermore, protective effect of carbon monoxide-releasing molecule-2 was significantly inhibited by the protein kinase C inhibitor, chelerythrine, when added before and concomitantly with carbon monoxide-releasing molecule-2. It was also observed that, perfusion with phosphatidylinositol 3-kinase inhibitor, wortmannin, before and concomitantly with carbon monoxide-releasing molecule-2 was not able to inhibit carbon monoxide-releasing molecule-2-induced cardioprotection. Interestingly, we observed that wortmannin perfusion before ischaemia and continued till reperfusion significantly inhibited carbon monoxide-releasing molecule-2-mediated cardioprotection. Our findings suggest that the carbon monoxide-releasing molecule-2 treatment may activate the p38 mitogen-activated protein kinase ß and protein kinase C pathways before ischaemia and phosphatidylinositol 3-kinase pathway during reperfusion which may be responsible for the carbon monoxide-releasing molecule-2-mediated cardioprotective effect.

Gaucher's disease.

Gaucher's disease is the most common group of lysosomal storage disorders caused by defective activity of an enzyme beta-glucosidase leading to accumulation of glucocerebroside in cells of macrophage lineage. Accumulation of glucosylceramide in tissues leads to multisystem organ involvement viz. liver, spleen, bone marrow, lungs and central nervous system. Serum beta=glucosidase levels <15% of mean normal activity confirms the diagnosis, enzyme replacement being the only definitive treatment. We report a clinical case of a 21 year male with Gaucher's disease. To the best of our knowledge only six cases of Gaucher's disease have been reported from India so far.

Electroconvulsive therapy in drug resistant neuroleptic malignant syndrome.

We report a case of a 20 years female referred to us with a history of a brief psychotic episode for which she was given inj. Haloperidol. The patient presented in an unconscious state with high grade fever. The diagnosis was kept as neuroleptic malignant syndrome after ruling out other possibilities. The patient did not respond to Bromocriptine and Dantrolene. With the recent evidence of electroconvulsive therapy being useful in these patients, we went ahead with the same. We present this case to share our experience of the excellent response of neuroleptic malignant syndrome to electroconvulsive therapy.