Biomedical subjects

J M Lembke

Publications and source records attributed to J M Lembke.

4 recordsLinked to original sources

PubMed2000

Universal newborn hearing screening.

BACKGROUND: New technology has made universal newborn hearing screening possible. Our goal was to investigate the feasibility of universal newborn screening using distortion product otoacoustic emissions (DPOAE) on infants in a community hospital in a normal newborn nursery. METHODS: We used DPOAE to screen newborn infants from February 1997 to March 1999. RESULTS: Of 1002 infants, 111 failed the initial screen (11.1%). When screening was repeated, only 2 infants failed. One infant failed the second screen and a tympanogram. He was treated and he passed a third use of DPOAE. An additional infant failed the repeat screen but passed the tympanogram. That infant was referred on for auditory brain response testing. CONCLUSIONS: DPOAE testing can be accomplished easily in a normal newborn nursery with an acceptable false-positive rate when a two-stage approach is used. The cost for each test was $19.88. The cost to find the 1 infant with sensory neural hearing loss was $22,114.

Acoustic Impedance Tests↗

PubMed1994

Systemic factors and renal hemodynamic effects of high-protein meal versus low-protein meal in conscious dogs.

The effects of a high-protein (HP) and low-protein (LP) meal on glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and renal vascular resistance (RVR) were examined in conscious dogs. Ingestion of the HP and LP meal produced a temporary increase in systemic hemodynamic parameters due in part to a 'cephalic phase' of sympathetic excitement. However only the HP significantly altered renal hemodynamics, i.e. GFR, ERPF and RVR. Plasma renin activity (PRA), serum aldosterone and plasma atrial natriuretic peptide (ANP) concentrations were not significantly altered by either a HP or LP meal. Of all the serum electrolytes measured, serum Ca2+ concentrations were significantly lower after a HP meal. It would appear that protein-meal-induced changes in renal hemodynamics are independent of changes in systemic hemodynamics. The exact mechanism of action of a HP meal on renal hemodynamics is not clear, but it appears that one mechanism by which a HP meal may alter renal hemodynamics is by altered calcium homeostasis.

Animals↗

PubMed1993

High-calcium diet in spontaneously hypertensive rats: intervention with calcium antagonist verapamil.

A number of studies have shown an antihypertensive effect for high-calcium diets, but others have found no effect or, even a prohypertensive effect. Because of these disparate results, studies were conducted in spontaneously hypertensive rats (SHR) fed either a normal calcium diet (1.0% calcium) or a high-calcium diet (4.0% calcium) with or without verapamil HCl (50 mg/kg body weight) from ages 5 to 12 weeks. Systolic blood pressure (SBP) and heart rate (HR) were measured by indirect tail cuff method. During the analysis of the electrolytes and vasoactive hormones monitored in this study, it was found that rats fed high-calcium diet had significantly elevated serum ionized and total calcium and calcium excretion. Systolic blood pressure for the verapamil-normal calcium diet (week 5, 148 +/- 4 mm Hg; week 7, 162 +/- 4 mm Hg) did not differ significantly from that of normal calcium diet (week 5, 152 +/- 2 mm Hg; week 7, 160 +/- 1 mm Hg). The high-calcium diet potentiated the development of hypertension, i.e., SBP was (157 +/- 2 mm Hg) on the 5th week and (174 +/- 4 mm Hg) on the 7th week. Conversely, verapamil high-calcium diet prevented the development of hypertension (week 5, SBP was 139 +/- 4 mm Hg; week 7, SBP was 146 +/- 3 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Influence of calcium infusion on plasma atrial natriuretic peptide in conscious dogs: intervention with calcium antagonist, verapamil.

In studies in conscious dogs, 1 liter 0.3% calcium chloride infusion resulted in a 163% increase in serum ionized calcium (iCa2+), 166% increase in plasma immunoreactive atrial natriuretic peptide (irANP) and 33% increase in mean blood pressure with significant positive correlation between serum iCa2+ and plasma irANP levels. Pretreatment with verapamil reversed the effects of calcium infusion. These studies have demonstrated that calcium ions play an important role in ANP secretion with reversal by calcium antagonist, verapamil. Hyponatremia seen with calcium infusion could reflect calcium-enhanced sodium excretion. Hypercalcemia was accompanied by non-significant changes in plasma renin activity and significantly elevated serum aldosterone not reversed by verapamil.

Acute Disease↗