The sake yeast YHR032W/ERC1 allele contributes to the regulation of the tetrahydrofolate content in the folate synthetic pathway in sake yeast strains.

To elucidate the mechanism underlying tetrahydrofolate (THF) accumulation in sake yeast strains compared with that in laboratory yeast strains, we performed a quantitative trait locus (QTL) analysis. The results revealed that the sake yeast ERC1 allele contributes to an increase in the ratio of THF to the total folate content in sake yeast.

Sake yeast YHR032W/ERC1 haplotype contributes to high S-adenosylmethionine accumulation in sake yeast strains.

Sake yeasts are ideally suited for sake making, producing higher levels of ethanol, proliferating at lower temperatures, and producing greater levels of various aromatic components and nutrients than laboratory yeasts. To elucidate the mechanism underlying S-adenosylmethionine (SAM) accumulation in sake yeast strains compared with that in laboratory yeast strains, we performed quantitative trait locus (QTL) analysis and identified a significant QTL on chromosome VIII. Of the 165 genes mapped at 49.8 cM from the left-end DNA marker of chromosome VIII, we focused on the YHR032W/ERC1 gene, encoding a member of the multi-drug and toxin extrusion family having antiporter activity and involved in SAM accumulation and ethionine resistance. Expression of the sake yeast ERC1 haplotype (K7ERC1) in a low- and high-copy number plasmid BYΔerc1 resulted in intracellular SAM accumulation, whereas expression of the laboratory yeast ERC1 haplotype (XERC1) did not. Comparison between DNA sequences of K7ERC1 and XERC1 revealed three amino acid substitutions: S51N, V263I, and N545I. Site-directed mutagenesis revealed that the N545I frameshift mutation was responsible for the K7ERC1 phenotype. These results indicate that K7ERC1 contributes to SAM accumulation in sake yeast strains.

Clinical prediction rule for neurological sequelae due to acute encephalopathy: a medical community-based validation study in Harima, Japan.

OBJECTIVES: This study aimed to verify the screening performance of our clinical prediction rule for neurological sequelae due to acute encephalopathy (NSAE-CPR), which previously identified the following three variables as predictive of poor outcomes: (1) refractory status epilepticus; (2) consciousness disturbance and/or hemiplegia at 6 hours from onset and (3) aspartate aminotransferase >90 IU/L within 6 hours of onset. DESIGN: Medical community-based multicentre retrospective cohort study. SETTING: Six regional hospitals in Harima and one tertiary centre in Kobe, Japan, from 2008 to 2012. PARTICIPANTS: We enrolled a total of 1612 patients aged <16 years who met the diagnostic criteria for an initial diagnosis of complex febrile seizure. Patients with a history of neurological disease and those included in the derivation cohort were excluded. PRIMARY OUTCOME MEASURES: Univariate and multivariate analyses were performed to determine the association between each of the three predictor variables and poor AE outcome (Pediatric Cerebral Performance Category score ≥2). Receiver operating characteristic curve (ROC) analysis was also performed to assess the screening performance of the NSAE-CPR. RESULTS: The ROC analysis identified at least one of the three predictive variables as an optimal cut-off point, with an area under the curve of 0.915 (95% CI 0.825 to 1.000). The sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios and Matthews correlation coefficient were 0.867, 0.954, 0.149, 0.999, 18.704, 0.140 and 0.349, respectively. CONCLUSIONS: Our findings indicate that the NSAE-CPR can be used for the screening and identification of patients with poor outcomes due to acute encephalopathy within 6 hours of onset.

Development of an enzyme-linked immunosorbent assay for serological diagnosis of tick-borne encephalitis using subviral particles.

The similarity of symptoms produced by tick-borne encephalitis (TBE) and Japanese encephalitis (JE) and the high degree of cross-reactivity between TBE and JE viruses by serological tests make the development of a differential diagnostic test a priority. In this study, recombinant prM/E proteins of TBE virus strain Oshima 5-10 expressed in mammalian cells resulted in the release of subviral particles (SPs) into the culture medium. Using the SPs as antigens, enzyme-linked immunosorbent assay (ELISA) systems were developed to detect TBE virus-specific IgM and IgG antibodies, designated SP-IgG and SP-IgM ELISAs, respectively. Of 83 serum samples from encephalitis patients in Khabarovsk, Russia, which were positive with the neutralization test (NT), 82 were positive by the SP-IgG ELISA, for a sensitivity of 98.8%, which was higher than that of a commercial ELISA kit. All 12 NT-negative samples were also negative by the SP-IgG ELISA (specificity, 100%). Of 17 patient samples that were NT-positive, 16 (94.1%) were positive by the SP-IgM ELISA. Of 15 paired serum samples that yielded equivocal results by NT, 11 had positive results with the SP-IgM ELISA, indicating a diagnosis of TBE infection. The SP-IgG and SP-IgM ELISAs showed no cross-reactivity with antibodies to the JE virus. The results indicate that these ELISAs will be useful for the detection of TBE-specific antibodies.