Different prognoses in patients with profound sudden sensorineural hearing loss.

Background: Inner ear hemorrhage is increasingly recognized as a cochlear lesion that can cause profound sudden sensorineural hearing loss (SSNHL). Objectives: To investigate changes of cochlear and vestibular function and to compare therapeutic recovery from profound SSNHL induced by different etiologies. Material and methods: Eighty patients with profound SSNHL (≥90 dB) were divided into an inner ear hemorrhage group and a non-inner ear hemorrhage group by MRI. Statistical analysis was performed to compare the therapeutic effects from vertigo and hearing loss and the outcomes of follow-up in the two groups. Results: There were significant differences between the two groups in terms of the overall 14-day therapeutic response rate (20 vs. 48%), the incidence of imbalance (26.7 vs. 6%), the incidence of semicircular canal dysfunction on the affected side (60 vs. 20%), the incidence of abnormal C-VEMP and O-VEMP on the affected side (63.3 vs. 38%; and 60 vs. 30%, respectively), the average hearing threshold (74.2 ± 10.7 vs. 53.6 ± 11.4 dB), and the word recognition score (65.5 ± 21.7 vs. 83.5 ± 24.5%) at a 12-month follow-up. Conclusions and significance: A higher percentage of patients with profound SSNHL induced by inner ear hemorrhage were associated with vertigo and had a poor prognosis.

Serum selenium level in healthy Koreans.

Of trace elements in the serum of living organisms, selenium (Se) is an essential mineral and plays the role of an antioxidant as selenoproteins protecting the organism against oxidative damage induced by hydrogen peroxide, other lipid hydroperoxides, and their derivatives. The aim of this study was to determine the mean serum Se levels in healthy Korean volunteers (50 males and 50 females) by using an inductively coupled plasma-mass spectrometry method. The samples were collected at the Health Promotion Centre of Kangnam St. Mary's Hospital, College of Medicine, the Catholic University of Korea, Kangnam District, Seoul in accordance with procedures approved by the Institutional Review Board of the Catholic University of Korea. The mean serum Se level in healthy subjects was 112.05 +/- 30.42 microg/l. For gender, it was 120.81 +/- 27.37 microg/l for females and 103.29 +/- 31.05 microg/l for males. From the study result, there was a significant difference between the mean Se concentrations of gender groups (p = 0.0035). Also, the study indicated no effect of age on Se levels (p > 0.05) in the healthy individuals.

A nuclear restorer-of-fertility mutation disrupts accumulation of mitochondrial ATP synthase subunit alpha in developing pollen of S male-sterile maize.

Mitochondrial biogenesis and function depend upon the interaction of mitochondrial and nuclear genomes. Forward genetic analysis of mitochondrial function presents a challenge in organisms that are obligated to respire. In the S-cytoplasmic male sterility (CMS-S) system of maize, expression of mitochondrial open reading frames (orf355-orf77) conditions collapse of developing haploid pollen. Nuclear restorer-of-fertility mutations that circumvent pollen collapse are often homozygous lethal. These spontaneous mutations potentially result from disruption of nuclear genes required for mitochondrial gene expression, in contrast to homozygous-viable restorer-of-fertility alleles that function to block or compensate for the expression of mitochondrial CMS genes. Consistent with this hypothesis, the homozygous-lethal restoring allele historically designated RfIII was shown to be recessive in diploid pollen produced by tetraploid CMS-S plants. Accordingly, the symbol for this allele has been changed to restorer-of-fertility lethal 1 (rfl1). In haploid rfl1 pollen, orf355-orf77 transcripts and mitochondrial transcripts encoding the alpha-subunit of the ATP synthase (ATPA) were decreased in abundance. Haploid rfl1 pollen failed to accumulate wild-type levels of ATPA protein, indicating that functional requirements for mitochondrial protein accumulation are relaxed in maize pollen. The CMS-S system and rfl mutations therefore allow for the selection of nuclear mutations disrupting mitochondrial biogenesis in a multicellular eukaryote.