Otoacoustic emissions as a screening test for hearing impairment in children

Transient evoked otoacoustic emissions (TEOAEs) are low amplitude sound waves produced by the healthy cochlea. They can be recorded with a microphone in the external ear. TEOAEs are abolished by hearing losses of 30 dB or more. The feasibility of using TEOAEs as a screening test for hearing loss in children was studied. TEOAE recordings were attempted in 56 children attending an audiology clinic. Recordings were possible from both ears in 52 children; of these 104 ears, 32 had hearing deficits of 30 dB or more. Hearing status was compared with the results of six TEOAE screening criteria. All criteria had a sensitivity of 1.00. Four standard TEOAE criteria yielded specificities of 0.46-0.58. Two new criteria derived from analysis of limited frequencies from the TEOAE waveform gave specificities of 0.76 and 0.82. It can be concluded that, when appropriate pass/fail criteria are employed, TEOAEs are a feasible screening test in children.     

Isolation, culture, and characterization of endothelial cells from mouse glomeruli

BACKGROUND: Cloned glomerular endothelial cells (GENC) have many potential uses and applications in immunologic and physiologic studies. Propagation of GENC has been difficult and available homogeneous GENC, particularly from mice, are limited. Herein we report isolation, cloning, propagation, and characterization of GENC from mice. METHODS: tsA58 immorto mice were used to isolate glomerular cells. Glomeruli were isolated by differential sieving, and decapsulated explants were cultured in permissive and optimal conditions for endothelial cells. The primary cells from glomerular outgrowths were expanded, taking advantage of the temperature-sensitive tsA58 gene, and then the cells were allowed to undergo spontaneous transformation. The cells were then sorted using anti-CD31 antibodies and their capacity to uptake acetylated-low-density lipoprotein (LDL). Individual subclones isolated by patch cloning were characterized using multiple markers. RESULTS: One of the homogeneous clones was morphologically endothelial-like, positive for CD31, CD106, CD62E, CD54, and acetylated-LDL uptake, formed tubes, and was negative for epithelial and mesangial cell markers. The functional properties of this GENC clone appeared to be intact, and signaling pathway was not altered. Two of the clones displayed the characteristics of either visceral epithelial or mesangial cells. CONCLUSION: The identified clones should have utility in multiple areas of investigation.     

The diagnosis of glomerular diseases: acute glomerulonephritis and the nephrotic syndrome

Rapid and efficient diagnosis of diseases presenting as acute glomerulonephritis and/or nephrotic syndrome is critical for early and appropriate therapy aimed at preservation of renal function. Although there may be overlap in clinical presentation, and some patients present with clinical features of both syndromes, this analysis serves as an initial framework to proceed with serologic testing and/or pathologic confirmation en route to final diagnosis. Efficient and timely diagnosis is essential in these situations because progression to end-stage renal disease may result if the underlying disease is not promptly treated.     

Diagnosis and treatment of nephrotic syndrome

Prompt diagnosis is essential in the planning of effective treatment for the underlying diseases responsible for nephrotic syndrome. In this review, the typical clinical and laboratory features that facilitate diagnosis of these disorders are discussed. The distinction between systemic diseases, involving the kidney, and primary glomerular diseases is emphasised. These clinical and pathological distinctions influence prognosis, and form the basis of therapy to treat the underlying disorders. Our discussion focuses on diagnosis and specific treatment of these diseases, as well as therapy of the clinical consequences of nephrotic syndrome per se.