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Biomedical subjects

G S Lefavour

Publications and source records attributed to G S Lefavour.

8 recordsLinked to original sources

Effect of variations in dietary sodium intake on sodium excretion in mature rats.

Sprague-Dawley rats weighing 400 g or more were studied to determine whether their continued weight gain affects renal sodium handling. Rats maintained on a wide range of sodium intakes gained 3.9 +/- 0.4 g/day. The intercept of a linear regression of intake against urinary excretion provided an estimate of the minimum daily requirement for sodium intake of 247 +/- 33 microEq/day. When more than this required amount was ingested, the animals excreted the excess quantitatively in the urine. When less was ingested they continued to gain weight at a slower rate, 1.6 +/- 0.6 g/day, and remained in positive sodium balance. Nonetheless, they developed a sodium deficit manifested as retention of a sodium challenge. Thus, on an adequate dietary intake the normal physiological state of Sprague-Dawley rats of this size is one of chronic sodium retention rather than neutral sodium balance. In contrast, when inadequate sodium is ingested a deficit develops in the absence of external losses. These observations have important implications for the interpretation of studies of renal sodium handling in these animals.

Animals↗

Demonstration of an antibody to tubular epithelium in glomerulonephritis associated with obstructive uropathy.

It has been postulated that in some patients with obstructive and reflux uropathy proteinuria develops through an intermediate mechanism of immune complex glomerulonephritis involving antigenic material of renal tubular epithelium. A patient with a unilateral ureterocele and nephrotic syndrome underwent bilateral renal biopsies during surgical correction of the obstruction. The obstructed kidney showed mild pyelonephritis, but both kidneys showed a glomerulopathy with electron-dense deposits in the mesangial and paramesangial regions associated with positive immunofluorescence for immunoglobulin M (IgM) and the third component of complement (C3). An IgM antibody was eluted from the biopsy specimens and it reacted by indirect immunofluorescence with normal renal tubular epithelium and with the patient's renal tubular epithelium. The eluate also reacted with pre-eluted glomeruli of the patient, but not with normal glomeruli. All antibody activity could be removed from the eluate by pre-incubation with normal kidney. It is concluded that the unilateral renal obstruction produced tubular injury so that as yet unidentified antigens were recognized by the immune system. The resultant antibody response gave rise to circulating immune complexes which were then deposited in glomeruli with subsequent glomerular damage and nephrotic syndrome.

Adult↗

Persistent hypophosphatemia following parathyroidectomy in end-stage renal disease: report of three patients.

Immediate and persistent hypophosphatemia following subtotal parathyroidectomy, despite discontinuation of phosphate binders, developed in three chronic hemodialysis patients. Although the serum phosphorous level is regularly reduced by parathyroidectomy in such patients, prolonged hypophosphatemia has not previously been reported. This observation supports the concept that parathyroid overactivity in end-stage renal disease is a major determinant of hyperphosphatemia.

Adult↗

Physician knowledge and practice patterns relating to diabetic nephropathy.

OBJECTIVE: To assess the knowledge and practice patterns of primary care physicians relating to the detection and treatment of diabetic nephropathy and to compare these findings with current standards of care. DESIGN: National survey. PARTICIPANTS: 1,000 randomly selected physicians. SETTING: Primary care. INTERVENTION: Mailed questionnaire consisting of a six-page "Diabetes Survey." RESULTS: Among the 1,000 primary care physicians, 950 were considered eligible for the survey. Sufficiently completed surveys were returned by 216 physicians, yielding an adjusted response rate of 22%. In general, patients with type 1 diabetes were monitored more intensively than those with type 2 diabetes. Primary care physicians were more likely to monitor patients for overt proteinuria (86%) than microalbuminuria (58%). Of the physicians who claimed to monitor patients for microalbuminuria, 39% chose inappropriate methods for detection, which lowers the percentage of physicians who correctly monitored for microalbuminuria to 37%. More than 95% of the respondents were aware of the benefits of angiotensin-converting enzyme inhibitors (ACEIs) in delaying the progression of diabetic nephropathy. Patients with proteinuria (86%) were more likely to be treated with an ACEI than were patients with microalbuminuria (79%). If a patient presented with proteinuria but without hypertension, the use of ACEIs fell to 75%. Rates of referral to a nephrologist were low at early stages of the disease (3% to 11%) and remained relatively low (28%) at later stages, even when serum creatinine was greater than 3 mg/dL. CONCLUSION: Further efforts directed toward education of primary care physicians about diabetic nephropathy have the potential to improve the care of patients with this disorder. These findings demonstrate a unique opportunity for pharmacists to become educators to physicians in their community.

Diabetic Nephropathies↗