A single sub-anesthetic dose of ketamine exerts rapid and sustained antidepressant effects. Here, we examined the role of the ventral hippocampus (vHipp)-medial prefrontal cortex (mPFC) pathway in ketamine's antidepressant response. Inactivation of the vHipp with lidocaine prevented the sustained, but not acute, antidepressant-like effect of ketamine as measured by the forced swim test (FST). Moreover, optogenetic as well as pharmacogenetic specific activation of the vHipp-mPFC pathway using DREADDs (designer receptors exclusively activated by designer drugs) mimicked the antidepressant-like response to ketamine; importantly, this was pathway specific, in that activation of a vHipp to nucleus accumbens circuit did not do this. Furthermore, optogenetic inactivation of the vHipp/mPFC pathway at the time of FST completely reversed ketamine's antidepressant response. In addition, we found that a transient increase in TrkB receptor phosphorylation in the vHipp contributes to ketamine's sustained antidepressant response. These data demonstrate that activity in the vHipp-mPFC pathway is both necessary and sufficient for the antidepressant-like effect of ketamine.

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The success of surgical management of lower pole stones is principally dependent on stone fragmentation and residual stone clearance. Choice of surgical method depends on stone size, yet all methods are subject to post-surgical complications resulting from residual stone fragments. Here we present a novel method and device to reposition kidney stones using ultrasound radiation force delivered by focused ultrasound and guided by ultrasound imaging. The device couples a commercial imaging array with a focused annular array transducer. Feasibility of repositioning stones was investigated by implanting artificial and human stones into a kidney-mimicking phantom that simulated a lower pole and collecting system. During experiment, stones were located by ultrasound imaging and repositioned by delivering short bursts of focused ultrasound. Stone motion was concurrently monitored by fluoroscopy, ultrasound imaging, and video photography, from which displacement and velocity were estimated. Stones were seen to move immediately after delivering focused ultrasound and successfully repositioned from the lower pole to the collecting system. Estimated velocities were on the order of 1 cm/s. This in vitro study demonstrates a promising modality to facilitate spontaneous clearance of kidney stones and increased clearance of residual stone fragments after surgical management.

Introduction: Dermatological conditions are common complications of Chronic Kidney Disease (CKD) affecting all most all patients. Present study aimed to evaluate the dermatological conditions and their association with age, sex and severity of CKD - without and with maintenance hemodialysis (MHD).Methods: It is a cross sectional and comparative study. Eighty-three patients with established CKD, without MHD (n=35) and with MHD (n= 48), attending nephrology unit, Bir Hospital and Shree Birendra Hospital from June 2008 to May 2009 were examined for dermatological disorders.Results: The mean age of patients were 46+15.6 years with male to female ratio of 1.8:1. Comparison of CKD without MHD and with MHD showed no statistical difference of age, sex, duration of treatment, blood urea and haemoglobin and significant difference of serum creatinine (5.3 + 3.0 mg/dl vs 9.1 + 4.5 mg/dl, p<0.001) respectively.Dermatological conditions were found in 100% CKD patients with pallor 91.5%, xerosis 75.9%, pigmentary changes 65%, pruritus 60.2%, skin infection 36.9%, vascular changes 16.8%, mucosal changes 67.4%, hair changes 59%, non -specific nail changes 81.9% and specific nail changes14.4%,.Specific (23.2% vs. 8.4%, p<0.03) and non- specific (91.4% vs 75%, p < 0.05) nail changes and hair abnormalities (74.3% vs. 47.9%, p<0.01) were significantly higher in CKD without MHD.Conclusions: Dermatological conditions are present in all CKD patients with or without MHD. A further prospective study is necessary to find out pathophysiology and beneficial effect of dialysis and transplantation in these conditions.Key words: chronic kidney disease, dermatological disorder, maintenance hemodialysis.