Digital Commons Network^™

Kalium Channelrhodopsins Are Natural Light-Gated Potassium Channels That Mediate Optogenetic Inhibition, Elena G Govorunova, Yueyang Gou, Oleg A Sineshchekov, Hai Li, Xiaoyu Lu, Yumei Wang, Leonid S Brown, François St-Pierre, Mingshan Xue, John L Spudich

Journal Articles

Channelrhodopsins are used widely for optical control of neurons, in which they generate photoinduced proton, sodium or chloride influx. Potassium (K+) is central to neuron electrophysiology, yet no natural K+-selective light-gated channel has been identified. Here, we report kalium channelrhodopsins (KCRs) from Hyphochytrium catenoides. Previously known gated potassium channels are mainly ligand- or voltage-gated and share a conserved K+-selectivity filter. KCRs differ in that they are light-gated and have independently evolved an alternative K+ selectivity mechanism. The KCRs are potent, highly selective of K+ over Na+, and open in less than 1 ms following photoactivation. The permeability ratio PK/PNa of …

The Dietary Management Of Potassium In Children With Ckd Stages 2-5 And On Dialysis-Clinical Practice Recommendations From The Pediatric Renal Nutrition Taskforce., An Desloovere, José Renken-Terhaerdt, Jetta Tuokkola, Vanessa Shaw, Larry A. Greenbaum, Dieter Haffner, Caroline Anderson, Christina L. Nelms, Michiel J S Oosterveld, Fabio Paglialonga, Nonnie Polderman, Leila Qizalbash, Bradley A. Warady, Rukshana Shroff, Johan Vande Walle

Manuscripts, Articles, Book Chapters and Other Papers

Dyskalemias are often seen in children with chronic kidney disease (CKD). While hyperkalemia is common, with an increasing prevalence as glomerular filtration rate declines, hypokalemia may also occur, particularly in children with renal tubular disorders and those on intensive dialysis regimens. Dietary assessment and adjustment of potassium intake is critically important in children with CKD as hyperkalemia can be life-threatening. Manipulation of dietary potassium can be challenging as it may affect the intake of other nutrients and reduce palatability. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, has developed clinical practice recommendations …

Evaluation Of Serum Magnesium Differences In Hypertensive Crises And Control Patients: A Randomly Matched Case-Control Study, Ifeanyi Chukwu O. Onor, Emily K. Johnston, Nicole G. Little, Lashira M. Hill, Oluwabunmi E. Lawal, Casey J. Payne, Mallory R. Coleman, Carolkim H. Huynh, Sarah E. Bilbe, Ahlam A. Ayyad, Kabrea J. Jones, Jasmine D. Kinnard, Rosanna Dastoori, Devinn K. Rolland, Amanda S. Miller, Robbie A. Beyl, Christopher J. Gillard, John I. Okogbaa, Daniel F. Sarpong, Rim M. Hadgu, Amne Borghol, Samuel C. Okpechi, Mihran V. Naljayan, Shane E. Sanno, Shane G. Guillory

School of Medicine Faculty Publications

Although the role of magnesium in blood pressure has been well studied among hypertensive patients, no study has explored the role of magnesium in hypertensive crises. The primary objective of this study is to evaluate the differences in serum magnesium levels between hypertensive crises patients and matched controls (age-, sex-, race-, and diabetes-matched) in a 1:1 random match. This study is a single-center, retrospective, chart review, case-control study of patients with hypertensive crises (case group) and patients without hypertensive crises (control group). Patients were included in the case group if they were 18 years of age or older with hypertensive …

Translational Evaluation Of Acid/Base And Electrolyte Alterations In Rodent Model Of Focal Ischemia, Sarah R. Martha, Lisa A. Collier, Stephanie M. Davis, Hilary A. Seifert, Christopher C. Leonardo, Craig T. Ajmo, Elspeth A. Foran, Justin F. Fraser, Keith R. Pennypacker

Neurology Faculty Publications

BACKGROUND AND PURPOSE: Acid/base and electrolytes could provide clinically valuable information about cerebral infarct core and penumbra. We evaluated associations between acid/base and electrolyte changes and outcomes in 2 rat models of stroke, permanent, and transient middle cerebral artery occlusion.

METHODS: Three-month old Sprague-Dawley rats underwent permanent or transient middle cerebral artery occlusion. Pre- and post-middle cerebral artery occlusion venous samples for permanent and transient models provided pH, carbon dioxide, oxygen, glucose, and electrolyte values of ionized calcium, potassium, and sodium. Multiple regression determined predictors of infarct volume from these values, and Kaplan-Meier curve analyzed morality between permanent and transient …

Attenuation Of Na/K-Atpase Mediated Oxidant Amplification With Pnaktide Ameliorates Experimental Uremic Cardiomyopathy, Jiang Liu, Jiang Tian, Muhammad Chaudhry, Nader G. Abraham, Joseph Shapiro

NYMC Faculty Publications

We have previously reported that the sodium potassium adenosine triphosphatase (Na/K-ATPase) can effect the amplification of reactive oxygen species. In this study, we examined whether attenuation of oxidant stress by antagonism of Na/K-ATPase oxidant amplification might ameliorate experimental uremic cardiomyopathy induced by partial nephrectomy (PNx). PNx induced the development of cardiac morphological and biochemical changes consistent with human uremic cardiomyopathy. Both inhibition of Na/K-ATPase oxidant amplification with pNaKtide and induction of heme oxygenase-1 (HO-1) with cobalt protoporphyrin (CoPP) markedly attenuated the development of phenotypical features of uremic cardiomyopathy. In a reversal study, administration of pNaKtide after the induction of uremic …

Randomised Clinical Trial: Polyethylene Glycol 3350 With Sports Drink Vs. Polyethylene Glycol With Electrolyte Solution As Purgatives For Colonoscopy--The Incidence Of Hyponatraemia., Rebecca Matro, Constantine Daskalakis, Dan Negoianu, Leo Katz, Cassandra Henry, Michael Share, David Kastenberg

Division of Gastroenterology and Hepatology Faculty Papers

BACKGROUND: Polyethylene glycol 3350 plus sports drink (PEG-SD) is a hypo-osmotic purgative commonly used for colonoscopy, though little safety data are available.

AIM: To evaluate the effect of PEG-SD on serum sodium (Na) and other electrolytes compared with PEG-electrolyte solution (PEG-ELS).

METHODS: We performed a single center, prospective, randomised, investigator-blind comparison of PEG-ELS to PEG-SD in out-patients undergoing colonoscopy. Laboratories were obtained at baseline and immediately before and after colonoscopy. The primary endpoint was development of hyponatraemia (Na/L) the day of colonoscopy. Changes in electrolyte levels were computed as the difference between the lowest value on the day of colonoscopy …