Repair of severe winter xylem embolism supports summer water transport and carbon gain in flagged crowns of the subalpine conifer Abies veitchii.

Xylem embolism induced by winter drought is a serious dysfunction in evergreen conifers growing at wind-exposed sites in the mountains. Some coniferous species can recover from winter embolism. The aim of this study was to determine whether wind direction influences embolism formation and/or repair dynamics on short windward and long leeward branches of asymmetrical `flagged' crowns.

Bundle sheath lignification mediates the linkage of leaf hydraulics and venation.

The lignification of the leaf vein bundle sheath (BS) has been observed in many species and would reduce conductance from xylem to mesophyll. We hypothesized that lignification of the BS in lower-order veins would provide benefits for water delivery through the vein hierarchy but that the lignification of higher-order veins would limit transport capacity from xylem to mesophyll and leaf hydraulic conductance (K ). We further hypothesized that BS lignification would mediate the relationship of K to vein length per area.

Clinical features of patients with GJB2 (connexin 26) mutations: severity of hearing loss is correlated with genotypes and protein expression patterns.

Mutations in the GJB2 (connexin 26, Cx26) gene are the major cause of nonsyndromic hearing impairment in many populations. Genetic testing offers opportunities to determine the cause of deafness and predict the course of hearing, enabling the prognostication of language development. In the current study, we compared severity of hearing impairment in 60 patients associated with biallelic GJB2 mutations and assessed the correlation of genotypes and phenotypes.

Deafness due to A1555G mitochondrial mutation without use of aminoglycoside.

Objectives/hypothesis: The objective was to clarify the characteristics of deafness associated with the A1555G mutation within mitochondrial 12S ribosomal RNA gene in the absence of aminoglycoside exposure.

Study Design: Clinical and genetic studies in family members with the A1555G mitochondrial mutation were performed.

Methods: The subjects were 123 maternally related members of a large Japanese family with the A1555G mutation.

Mutations in the COCH gene are a frequent cause of autosomal dominant progressive cochleo-vestibular dysfunction, but not of Meniere's disease.

The COCH gene is the only gene identified in man that causes autosomal dominantly inherited hearing loss associated with vestibular dysfunction. The condition is rare and only five mutations have been reported worldwide. All affected families showed a similar progressive hearing loss and vestibular dysfunction.

GJB2 deafness gene shows a specific spectrum of mutations in Japan, including a frequent founder mutation.

Mutations in the GJB2 gene (connexin 26) are the major cause of autosomal recessive non-syndromic hearing impairment in many populations. In contrast to the volume of information regarding the involvement of GJB2 mutations in hearing impairment in populations of European ancestry, less is known regarding other ethnic groups. In this study, we analyzed the GJB2 gene for mutations in 1227 hearing-impaired Japanese individuals.

Identification of 605ins46, a novel GJB2 mutation in a Japanese family.

Connexin 26 gene (GJB2) mutations are known to be responsible for a significant portion (30-80%) of autosomal recessive congenital severe to profound deafness. More than 60 recessive mutations in GJB2 have been reported and most consist of point mutations of a nucleotide. We report here a novel insertional GJB2 mutation consisting of a long repetitive nucleotide sequence.