Mitchell L. Halperin

Learn More
OBJECTIVE To develop hyponatremia (plasma sodium concentration [P(Na)] <136 mmol/L), one needs a source of water input and antidiuretic hormone secretion release to diminish its excretion. The administration of hypotonic maintenance fluids is common practice in hospitalized children. The objective of this study was to identify risk factors for the(More)
Significant gaps remain in our knowledge of the pathways of amino acid catabolism in humans. Further quantitative data describing amino acid metabolism in the kidney are especially needed as are further details concerning the pathways utilized for certain amino acids in liver. Sufficient data do exist to allow a broad picture of the overall process of amino(More)
BACKGROUND It is widely presumed that the development of postoperative hyponatremia (which may be severe) results from administration of hypotonic fluids while antidiuretic hormone is acting. OBJECTIVE To show that hyponatremia would occur in patients 24 hours after surgery if only near-isotonic solutions are given and to evaluate the mechanisms(More)
It is not uncommon for patients to present to the emergency room with severe weakness and a markedly low plasma potassium concentration. We attempted to identify useful clues to the diagnosis of hypokalaemic periodic paralysis (HPP), because its acute treatment aims are unique. We retrospectively reviewed charts over a 10-year period: HPP was the initial(More)
To maintain acid-base balance, the kidney must generate new bicarbonate by metabolizing glutamine and excreting ammonium (NH4 +). During chronic metabolic acidosis, the kidney should respond by increasing the rate of excretion of NH4 + to 200–300 mmol/day. If the rate of excretion of NH4 + is much lower, the kidney is responsible for causing or perpetuating(More)
BACKGROUND The reported prevalence of cerebral salt wasting has increased in the past three decades. A cerebral lesion and a large natriuresis without a known stimulus to excrete so much sodium (Na ) constitute its essential two elements. OBJECTIVES To review the topic of cerebral salt wasting. There is a diagnostic problem because it is difficult to(More)
BACKGROUND Gitelman syndrome (GS) most often results from mutations in the thiazide-sensitive sodium chloride cotransporter (NCC). Although the severity of symptoms may vary in patients who have the same mutations, a markedly different clinical presentation in family members with identical mutations is truly rare. METHODS Five patients (3 women and 2 men)(More)
BACKGROUND Hypokalemia and paralysis may be due to a short-term shift of potassium into cells in hypokalemic periodic paralysis (HPP) or due to a large deficit of potassium in non-HPP. Failure to make a distinction between HPP and non-HPP may lead to improper management. Therefore, we evaluated the diagnostic value of spot urine tests in patients with(More)
A new clinical approach to patients with disorders of potassium excretion is reported. This approach uses a urinary index, the ratio of potassium concentrations in the urine to vein after adjusting the urine potassium concentration for medullary water abstraction. This index provides a semiquantitative assessment of the apparent transtubular potassium(More)
It is advantageous to make an independent assessment of the potassium (K) secretory process and the luminal flow rate in the renal cortex to evaluate K handling by the kidney during hypokalemia or hyperkalemia. The transtubular potassium concentration gradient (TTKG) is a semiquantitative index of the activity of the K secretory process. The purpose of this(More)