George D. Ludwig

Incomplete renal tubular acidosis: Physiologic studies in three patients with a defect in lowering urine pH

Abstract A defect in ability to lower urine pH in response to ammonium chloride loading in the absence of systemic acidosis is defined as the syndrome of incomplete renal tubular acidosis. Three patients are described who had recurrent nephrolithiasis in association with incomplete renal tubular acidosis. Two of these had hypercalciuria, one of whom had nephrocalcinosis. The third patient had nephrocalcinosis without hypercalciuria. All patients had low urinary citrate levels. Two had defects of the renal concentrating mechanism, one of whom had potassium depletion. In one patient classic renal tubular acidosis subsequently developed. The ability to lower urine pH was tested by acute and chronic ammonium chloride loading and by sodium sulfate infusion. In two patients minimum urine pH after sodium sulfate infusion was approximately 1 pH unit lower than after ammonium chloride loading. In one patient sodium restriction prior to acute ammonium chloride loading interfered with the patients ability to lower urine pH. A possible mechanism for the defect in ability to generate a steep blood-to-urine hydrogen ion gradient in patients with renal tubular acidosis is suggested.

A Genetic Study of Two Families Having the Acute Intermittent Type of Porphyria

Excerpt The prevalence of acute intermittent porphyria is greater than has been supposed, as a number of recent authors have emphasized (1-4), because so many cases with clinical expression of this...

Ochronosis from Quinacrine (Atabrine)

Excerpt Ochronosis is usually associated with the rare hereditary metabolic disease, alcaptonuria, in which there is a defect in the hepatic enzyme, homogentisic acid oxidase, and consequently an a...

Sarcoidosis of the skull.

Abstract One of the rarest manifestations of sarcoidosis is involvement of the skull; only five cases have been reported (1-5). Bone lesions of any type are rare, and osseous localization is usuall...

Effects of Beta-Adrenergic Blockade in the Carcinoid Syndrome.

Excerpt Although serotonin may be responsible for the diarrhea of the carcinoid syndrome, recent evidence suggests that bradykinen induces the flushes and the vascular phenomena. A rise in hepatic ...

Cerebral Gigantism with Intermittent Fractional Hypopituitarism and Normal Sella Turcica

Excerpt A syndrome of cerebral gigantism with normal sella turcica occurring in childhood has recently been described by Sotos and co-workers (1). In all of their patients the growth spurt leading ...

Biochemical Mechanism of Photohemolysis of Erythrocytes in Erythropoietic Protoporphyria.

Excerpt Erythropoietic protoporphyria (EPP), an inborn error of metabolism transmitted as a mendelian dominant trait, is characterized by increased erythrocyte protoporphyrin (EP) concentrations, s...