Maher, Frank T.

Familial metaphysial dysostosis has been described as it occurred among 18 members of a family in seven generations. The roentgenologic changes were very similar to those seen in vitamin D resistant rickets. No biochemical defect could be detected. Studies of renal function with special reference to tubular reabsorption of phosphorus gave normal values. The treatment of choice is osteotomy, after epiphysial closure has occurred, to correct the pronounced bowing of the legs. Administration of vitamin D in high doses has no effect on the course of this disease.

A fluorometric method was used to quantitate plasma epinephrine and norepinephrine during hemorrhagic and anaphylactic shock in healthy adult dogs anesthetized with pentobarbital. Arterial plasma was analyzed before and after hemorrhage in four dogs. Loss of approximately 18% of blood volume through rapid arterial bleeding caused no remarkable change in pressor amines. Loss of approximately one-third of the total blood volume decreased the mean arterial pressure by a range of 56–81% and invariably caused increased concentration of plasma pressor amines. The average concentration of epinephrine increased from 1.0 to 7.8 µg/1. of plasma, and that of norepinephrine increased from 2.5 to 3.6 µg. Additional bleeding caused further increase of plasma pressor amines. Seven dogs were given egg white intravenously to sensitize them. Subsequently, whenever a severe reaction (hypotension, bradycardia and respiratory depression) resulted from intravenous administration of egg white, venous plasma pressor amines increased. The average concentration of epinephrine increased from 0.7 to 7.7 µg/1. of plasma; norepinephrine increased in three dogs but remained unchanged or decreased in the remaining animals. Without a preceding ‘shock’ reaction, change in concentration of epinephrine-like substance was unremarkable. Intravenous administration of 1 mg of histamine base produced hypotension and usually slight increase of plasma pressor amines.

Application of hemodialysis to dogs has been complicated by an acute reaction consisting of hypotension, bradycardia and respiratory depression followed by instability and a mortality rate of about 30 per cent. This reaction appears to be a response to homologous blood used to fill the dialyzers. Sensitization occurs in survivors, and accentuated reactions with marked hemolysis are noted on subsequent challenge. Cross matching the donor and recipient bloods has not permitted an adequate determination of compatibility under the conditions of hemodialysis. Satisfactory hemodialysis may be accomplished in dogs by using autogenous blood or blood substitutes to fill the dialyzers.

The pharmacological and biochemical tests available for the diagnosis of pheochromocytoma were evaluated among 28 patients with proved tumors and 148 other patients in whom the diagnosis was suspected. Of the biochemical tests on urine, determinations of total metanephrines (MN) and of vanilmandelic acid (VMA) were much less subject to false-positive results than was determination of catecholamines (CA). Since urinary MN values changed the most in tumor patients, MN determination is preferred as the current screening test. Of the pharmacological tests, the histamine test continues to be the most valuable, especially when combined with determination of plasma CA concentration. The phentolamine (Regitine) test has not proved to be of any distinct value as a primary diagnostic aid. Any of the chemical or pharmacological tests occasionally may give a false-positive result. The urinary output of excessive amounts of homovanillic acid (HVA) was an indication of the presence of pheochromocytoma with some features histologically similar to other neural crest tumors but was not an indication of malignancy. Reliable diagnosis of pheochromocytoma still must be based on multiple studies in an appropriate clinical setting.

Renal performance of seven patients undergoing replacement of the aortic valve was investigated. The initial portion of cardiopulmonary bypass was characterized by low arterial blood pressure and anuria. With a subsequent rise in arterial pressure during bypass, urine flow suddenly increased in five patients. In two patients urine flow did not resume until immediately after cardiopulmonary bypass. The high rate of urine flow at these times is thought to be partially due to a glucose-induced osmotic diuresis. The glomerular filtration rate (inulin clearance) and the effective renal plasma flow (PAH clearance) fell with induction of anesthesia and opening of the chest, but there was no further drop in these functions as a result of total body perfusion. Urine osmolality fell significantly during and immediately after cardiopulmonary bypass. The changes in urine osmolality are thought to be due in part to the osmotic diuresis and in part to a temporary reduction in the renal medullary hyperosmolality secondary to hemodynamic changes. All of the alterations in renal function were reversible in the patients studied.