Harry G. Preuss

The Effect of Bence Jones Protein on the in vitro Function of Rabbit Renal Cortex

Processes which take place in a distinct part of the kidney, such as the proximal tubule, can be investigated in vitro. PAH accumulation, a proximal tubule function, was used to ind

Renotropic Factor(s) in Plasma from Uninephrectomized Rats

The nature of the stimulus(i) that initiates renal hypertrophy and hyperplasia is unknown. This investigation assays plasma of uninephrectomized rats for activity of renotropin(s), a humoral factor(s)

Renal Glutamate Metabolism in Acute Metabolic Acidosis

Four hours following oral NH4Cl, renal glutamate concentrations in rats decreased from 31.1 µ moles/g dry wgt to 23.5 µ m/g dry weight (p

Hypomagnesemia Following the Diuresis of Post-Renal Obstruction and Renal Transplant

Three unusual cases are described which demonstrated hypomagnesemia and symptoms resembling magnesium deficiency syndrome. The hypomagnesemia was most likely secondary to urinary losses from diuresis following release of post-renal obstruction and renal homotransplantation. Heretofore, this association has not been described. Case 1 was unique because of the post-obstructive diuresis in the face of marked renal impairment. Case 2 is noteworthy because of the profound hypomagnesemia, 0.4 mEq/1, and because of the development of congestive heart failure. The rapid improvement noted in cardiac function with magnesium replacement suggests a relationship to magnesium deficiency.

Glutamate Metabolism and Ammonia Production in Dog Kidneys

In vivo, over a short 2-hour period, renal ammonia production in dogs increased (+41%) and renal glutamate concentrations decreased (-21%) following acid challenge. Since glutamate is an inhibitor of glutamine deamidating enzyme, glutaminase I, these results are compatible with the concept that during acid challenge, lowered concentrations of glutamate increase ammoniagenesis via accelerated glutamine deamidation. However, glutamate infusions in vivo into dogs do not alter ammoniagenesis from glutamine. To explain this paradox, evidence is presented that exogenous glutamate does not reach ammonia producing sites. In vivo, exogenous glutamate neither increases nor decreases renal ammonia production; whereas exogenous alanine, which must form glutamate through transamination in order to be deaminated, produces a good deal of ammonia. That both the amino nitrogen of glutamine and the amino nitrogen of alanine produced more ammonia than the amino nitrogen of glutamate at equimolar concentrations in isolated dog tubules suggests that there is a relative impermeability of glutamate to ammonia producing sites even in vitro. Despite this relative barrier, dog tubules do produce ammonia from glutamate allowing one to conclude that this substrate does reach ammonia producing sites in vitro. Here, exogenous glutamate added to incubation medium did depress utilization of glutamine significantly. We conclude that there may be an important role for glutamate concentrations at ammonia producing sites in regulating renal ammoniagenesis.

Renal Ammonia Production in the Presence of Citric Acid Cycle Blockade

Summary The addition of 1.0 mM fluorocitrate to kidney slices markedly inhibited gluconeogenesis from citrate, while 10.0 mM malonate did the same to gluconeogenesis from glutamate. Both inhibitors increased ammonia production from glutamate by kidney slices. Injections of malonate and fluorocitrate into rats increased ammonia excretion in vivo despite no significant change in urine volume or pH. Therefore, both in vivo and in vitro, a slow down in citric acid cycle activity by two agents blocking at different points in the cycle resulted in augmented renal ammoniagenesis.

Influence of Extracellular and Intracellular Factors on Hippurate Uptake by Rat Kidney Cortex: Acid-Base Effects

Summary The studies presented show that the accumulation of hippurate and presumably other organic anions is modified by a complex of several intra- and extracellular events during changing acid-base states. These extra- and intracellular events may act in seemingly opposite ways to determine the final sum total of hippurate accumulation by the slice.

Azotemic Inhibition of Renal Hippurate Accumulation in Vivo

Inhibition of renal hippurate transport in vitro has been reported previously. Since many assessments of renal blood flow and tubule function are dependent on hippurate transport, t

Poster 159 Anti-inflammatory Actions of Low-dose Chondroitin Sulfate in Annulus Fibrosus Cells

Disclosures: M. L. Noon, none. Objective: To evaluate the screening practices and preparticipation evaluation (PPE) forms used to identify, or raise suspicion of, cardiovascular abnormalities in collegiate student athletes. Design: A total of 347 National Collegiate Athletic Association (NCAA) Division I universities were surveyed in 2010, with 257 participated in the telephone survey (74%) and 287 PPE forms collected (83%). Setting: NCAA Division I universities; telephone and/or e-mail survey based from the Medical College of Wisconsin. Participants: 347 NCAA Division I universities. Interventions: N/A. Main Outcome Measures: Information about the nature of the preparticipation screening process was requested from team physicians and certified athletic trainers during a telephone or e-mail survey. In addition, a copy of their PPE form was requested to evaluate for inclusion of the 12 specific American Heart Association (AHA) recommendations (2007 consensus) for cardiovascular screening of competitive athletes. Results: All 257 universities (100%) who participated in the telephone or e-mail survey required preparticipation screening for freshman and transfer athletes; however, only 83 universities (32%) required an annual PPE for returning athletes. At 84.8% of universities, the preparticipation screening must be done by a team physician or at campus health services, while 15.2% allowed athletes to have the PPE completed by their own family physician prior to arriving on campus. Standardized PPE forms were used at 242 universities (94%). Eleven universities (4%) were using the recently updated American College of Sports Medicine, 4th edition PPE. Sixteen universities (6%) were using the 3rd edition of the PPE. The remaining 260 universities (90%) were not using either of these forms. Of the PPE forms that were analyzed from 287 Division I universities, 44% of the universities included 9 or more AHA recommended screening items, 54% had 5-8 items and 2% had 4 or less AHA recommended screening items. Conclusions: The majority of current PPE forms used by NCAA Division I universities do not meet the AHA recommendations, therefore, may not be effectively screening collegiate student athletes for cardiovascular abnormalities that may lead to sudden cardiac death. Poster 159 Anti-inflammatory Actions of Low-dose Chondroitin Sulfate in Annulus Fibrosus Cells. Gwendolyn A. Sowa, MD, PhD (University of Pittsburgh, Pittsburgh, PA, United States); Judith Balk, Paulo Coelho, James D. Kang, MD, Michael Liggon, Carolyn Moore, Harry G. Preuss, MD, Nam V. Vo, PhD.

Poster 123 Increased Proinflammatory Gene Expression in Annulus Fibrosis Cells Exposed to Omega-3 Fatty Acids

Disclosures: J. Diaz-Ruiz, none. Patients or Programs: A 77-year-old man with progressive gait abnormality and behavioral and cognitive abnormalities. Program Description: A 77-year-old man with a history of chronic alcohol abuse and chronic gastritis was referred to the physiatrist due to lower limb weakness. He had paresthesia in his hands and feet of 1 year, with progressive lower limb weakness, gait abnormality, frequent falling, and instability. He also presented with recent memory loss, visual hallucinations, delirium, and irritability. Seven months after onset of symptoms, he became wheelchair bound. On physical examination, he had lower limb spasticity, vibratory and thermal sensory abnormalities, areflexia, and Babinski sign. A Functional Independence Measure of 50 was established. The patient’s history did not reveal preexisting diseases. Cervical and thoracic magnetic resonance imaging showed posterior myelopathy. The N19 latency was significantly prolonged on median somatosensory evoked potentials, and a posterior tibial somatosensory evoked potential had an absent P45. Nerve conduction studies and electromyography were both normal. Laboratory tests showed megaloblastic anemia and low vitamin B12 levels. Cyanocobalamin was started. Setting: A university hospital. Results: Three months after cyanocobalamin administration, improvement in gait was observed. The patient could walk with a cane, and cognitive and psychiatric symptoms improved. The Functional Independence Measure score improved to 106; N19 and P45 also improved. Discussion: This is a typical case of cyanocobalamin deficiency with encephalomyelopathy that markedly improved with vitamin B12 administration despite the severity of symptoms. Conclusions: Cyanocobalamin deficiency is an important cause of myelopathy and of psychiatric and cognitive symptoms in the elderly that produces severe functional impairment and that dramatically improves with the administration of the vitamin.