Balaji Tamarappoo

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Five single-point aquaporin-2 (AQP2) mutations that cause non-X-linked nephrogenic diabetes insipidus (NDI) were characterized to establish the cellular defect and to develop therapeutic strategies. In Xenopus oocytes expressing AQP2 cRNAs, single-channel water permeabilities of mutants L22V, T126M, and A147T were similar to that of wild-type AQP2, whereas(More)
A cDNA has been isolated from human hippocampus that appears to encode a novel Na(+)-dependent, Cl(-)-independent, neutral amino acid transporter. The putative protein, designated SATT, is 529 amino acids long and exhibits significant amino acid sequence identity (39-44%) with mammalian L-glutamate transporters. Expression of SATT cDNA in HeLa cells induced(More)
This review summarizes recent progress in water-transporting mechanisms across cell membranes. Modern biophysical concepts of water transport and new measurement strategies are evaluated. A family of water-transporting proteins (water channels, aquaporins) has been identified, consisting of small hydrophobic proteins expressed widely in epithelial and(More)
UNLABELLED A recently developed camera system for high-speed SPECT (HS-SPECT) myocardial perfusion imaging shows excellent correlation with conventional SPECT. Our goal was to test the diagnostic accuracy of an automated quantification of combined upright and supine myocardial SPECT for detection of coronary artery disease (CAD) (≥ 70% luminal diameter(More)
OBJECTIVES We aimed to evaluate whether pericardial fat has value in predicting the risk of future adverse cardiovascular outcomes. BACKGROUND Pericardial fat volume (PFV) and thoracic fat volume (TFV) can be routinely measured from noncontrast computed tomography (NCT) performed for calculating coronary calcium score (CCS) and may predict major adverse(More)
INTRODUCTION Pericardial fat is emerging as an important parameter for cardiovascular risk stratification. We extended previously developed quantitation of thoracic fat volume (TFV) from non-contrast coronary calcium (CC) CT scans to also quantify pericardial fat volume (PFV) and investigated the associations of PFV and TFV with CC and the Metabolic(More)
Controversy exists concerning the relation between diagonal ear lobe crease (DELC) and coronary artery disease (CAD). We examined whether DELC is associated with CAD using coronary computed tomography (CT) angiography. We studied 430 consecutive patients without a history of coronary artery intervention who underwent CT angiography on a dual-source scanner.(More)
OBJECTIVES We evaluated the association between pericardial fat and myocardial ischemia for risk stratification. BACKGROUND Pericardial fat volume (PFV) and thoracic fat volume (TFV) measured from noncontrast computed tomography (CT) performed for calculating coronary calcium score (CCS) are associated with increased CCS and risk for major adverse(More)
We reported that several aquaporin-2 (AQP2) point mutants that cause nephrogenic diabetes insipidus (NDI) are retained in the endoplasmic reticulum (ER) of transfected mammalian cells and degraded but can be rescued by chemical chaperones to function as plasma membrane water channels (Tamarappoo, B. K., and Verkman, A. S. (1998) J. Clin. Invest. 101,(More)
In mammalian cells, the basal Na+-dependent uptake for many of the neutral amino acids is mediated by a transport activity designated System ASC. A cloned human brain cDNA sequence, ASCT1, encodes a Na+-dependent neutral amino acid transport activity that exhibits a substrate specificity similar to that commonly associated with System ASC. However, the(More)