Genomic structure and identification of novel mutations in usherin, the gene responsible for Usher syndrome type IIa.

Usher syndrome type IIa (USHIIa) is an autosomal recessive disorder characterized by moderate to severe sensorineural hearing loss and progressive retinitis pigmentosa. This disorder maps to human chromosome 1q41. Recently, mutations in USHIIa patients were identified in a novel gene isolated from this chromosomal region. The USH2A gene encodes a protein with a predicted molecular weight of 171.5 kD and possesses laminin epidermal growth factor as well as fibronectin type III domains. These domains are observed in other protein components of the basal lamina and extracellular matrixes; they may also be observed in cell-adhesion molecules. The intron/exon organization of the gene whose protein we name "Usherin" was determined by direct sequencing of PCR products and cloned genomic DNA with cDNA-specific primers. The gene is encoded by 21 exons and spans a minimum of 105 kb. A mutation search of 57 independent USHIIa probands was performed with a combination of direct sequencing and heteroduplex analysis of PCR-amplified exons. Fifteen new mutations were found. Of 114 independent USH2A alleles, 58 harbored probable pathologic mutations. Ten cases of USHIIa were true homozygotes and 10 were compound heterozygotes; 18 heterozygotes with only one identifiable mutation were observed. Sixty-five percent (38/58) of cases had at least one mutation, and 51% (58/114) of the total number of possible mutations were identified. The allele 2299delG (previously reported as 2314delG) was the most frequent mutant allele observed (16%; 31/192). Three new missense mutations (C319Y, N346H, and C419F) were discovered; all were restricted to the previously unreported laminin domain VI region of Usherin. The possible significance of this domain, known to be necessary for laminin network assembly, is discussed in the context of domain VI mutations from other proteins.

Hospital admission following ambulatory surgery.

BACKGROUND: Ambulatory surgery continues to grow in quantity and complexity of procedures. Effective measures of "quality" are not readily apparent. "Unplanned admission rate" may well reflect the quality of care in this area. Identifying factors related to this event could be helpful in quality assessment and improvement. METHODS: A review of all unplanned admissions for a 3-year period in a University-affiliated teaching hospital. RESULTS: An overall rate of 0.85% (129/15,132) was observed. Rate varies by specialty and no one procedure was at higher risk. Pain control, cardiopulmonary, and bleeding problems as well as larger than anticipated procedures accounted for 73% of the admissions. CONCLUSIONS: Unplanned admission following ambulatory surgery is relatively rare but could reflect overall quality in terms of the system, physician, and patient. Comparisons between institutions and within institution requires defining key demographic elements whose identification for now remains a challenge.

Computer applications to electrophysiologic studies.

The automated studies performed at implant require little extra time and provide essential information for postoperative troubleshooting and patient management. The automated testing and analysis system is but one component in a comprehensive patient management system designed for and dedicated to pacing; the system is an integral part of a complete data management system which includes extensive follow-up and management sections.