Selective hydrolysis of the 3,6-anhydrogalacotosidic linkage in red algal galactan: a combination of reductive acid hydrolysis and anhydrous mercaptolysis.

Here we report a simple method for the structural analysis of red algal galactan containing 3,6-anhydrogalactose. Structural heterogeneity in the galactan was demonstrated by this method. For selective hydrolysis of 3,6-anhydrogalactosidic linkages in the galactan, conditions for reductive mild acid hydrolysis were examined by characterizing the resulting oligosaccharide alditols by anhydrous mercaptolysis. Residues other than alditols at the reducing ends, including labile 3,6-anhydrogalactose, were liberated quantitatively as diethyl dithioacetal derivatives, whereas alditols at the reducing ends were not derivatized and were liberated as alditols intact. The liberated sugars were then separated and measured quantitatively by gas-liquid chromatography. Heating of agarose in reductive hydrolysis with 0.3 M trifluoroacetic acid in the presence of an acid-stable reducing agent, 4-methyl morpholine borane, at 80 °C for 90 min and for 90 °C for 45 min was found to be optimum for the selective hydrolysis of 3,6-anhydrogalactosidic bonds, without detectable cleavage of other glycosidic bonds.

Direct metagenomic detection of viral pathogens in nasal and fecal specimens using an unbiased high-throughput sequencing approach.

With the severe acute respiratory syndrome epidemic of 2003 and renewed attention on avian influenza viral pandemics, new surveillance systems are needed for the earlier detection of emerging infectious diseases. We applied a "next-generation" parallel sequencing platform for viral detection in nasopharyngeal and fecal samples collected during seasonal influenza virus (Flu) infections and norovirus outbreaks from 2005 to 2007 in Osaka, Japan. Random RT-PCR was performed to amplify RNA extracted from 0.1-0.25 ml of nasopharyngeal aspirates (N = 3) and fecal specimens (N = 5), and more than 10 microg of cDNA was synthesized. Unbiased high-throughput sequencing of these 8 samples yielded 15,298-32,335 (average 24,738) reads in a single 7.5 h run. In nasopharyngeal samples, although whole genome analysis was not available because the majority (>90%) of reads were host genome-derived, 20-460 Flu-reads were detected, which was sufficient for subtype identification. In fecal samples, bacteria and host cells were removed by centrifugation, resulting in gain of 484-15,260 reads of norovirus sequence (78-98% of the whole genome was covered), except for one specimen that was under-detectable by RT-PCR. These results suggest that our unbiased high-throughput sequencing approach is useful for directly detecting pathogenic viruses without advance genetic information. Although its cost and technological availability make it unlikely that this system will very soon be the diagnostic standard worldwide, this system could be useful for the earlier discovery of novel emerging viruses and bioterrorism, which are difficult to detect with conventional procedures.

Mutation analyses of genes on 6p12-p11 in patients with juvenile myoclonic epilepsy.

Juvenile myoclonic epilepsy (JME) is a distinct form of idiopathic generalized epilepsy (IGE). One of the candidate regions for human JME has been mapped on chromosome band 6p11-p12 by linkage analyses and is termed EJM1 (MIM 254770). Recently, we reported the reduction of the EJM1 region to 3.5cM that contains 18 genes, the exclusion of three genes (LRRC1, GCLC, KIAA0057) by mutation analyses, and the identification of Myoclonin1/EFHC1 as the EJM1 gene. Here, we describe detailed physical and transcriptome maps of the 3.5cM EJM1 region, and detailed results of mutation analyses for the remained 14 genes (HELO1, GCMA, KIAA0936, FBXO9, GSTA3, GSTA4, PTD011, KIAA0576, LMPB1, IL17F, MCM3, PKHD1, KIAA0105, TFAP2B) in patients with JME. We identified 49 single nucleotide changes in eight genes. Twelve amino acid substitutions occurred in two genes, 11 silent mutations in seven genes, and 26 in the non-coding or intronic regions of seven genes. Twelve amino acid substitutions in the two genes (IL17F, PKHD1) were also observed in healthy control individuals or did not co-segregate with the disease phenotypes in other family members. Thus, the absence of significant and potentially functional mutations in the remaining 14 genes further supports the concept that Myoclonin1/EFHC1 is the EJM1 gene in chromosome 6p12.

Wavelet-transform analysis of spectral shearing interferometry for phase reconstruction of femtosecond optical pulses.

We introduce a novel method for retrieving the phase from a spectral shearing interferogram, based on wavelet-transform technique. We demonstrate with both theoretical and experimental data that this technique provides an alternative and reliable technique for phase retrieval, particularly for highly structured pulse spectra.

Mutations in EFHC1 cause juvenile myoclonic epilepsy.

Juvenile myoclonic epilepsy (JME) is the most frequent cause of hereditary grand mal seizures. We previously mapped and narrowed a region associated with JME on chromosome 6p12-p11 (EJM1). Here, we describe a new gene in this region, EFHC1, which encodes a protein with an EF-hand motif. Mutation analyses identified five missense mutations in EFHC1 that cosegregated with epilepsy or EEG polyspike wave in affected members of six unrelated families with JME and did not occur in 382 control individuals. Overexpression of EFHC1 in mouse hippocampal primary culture neurons induced apoptosis that was significantly lowered by the mutations. Apoptosis was specifically suppressed by SNX-482, an antagonist of R-type voltage-dependent Ca(2+) channel (Ca(v)2.3). EFHC1 and Ca(v)2.3 immunomaterials overlapped in mouse brain, and EFHC1 coimmunoprecipitated with the Ca(v)2.3 C terminus. In patch-clamp analysis, EFHC1 specifically increased R-type Ca(2+) currents that were reversed by the mutations associated with JME.

Recent developments in the quest for myoclonic epilepsy genes.

Understanding the latest advances in the molecular genetics of the epilepsies is important, as it provides a basis for comprehending the new practice of epileptology. Epilepsies have traditionally been classified and subtyped on the basis of clinical and neurophysiologic concepts. However, the complexity and variability of phenotypes and overlapping clinical features limit the resolution of phenotype-based classification and confound epilepsy nosology. Identification of tightly linked epilepsy DNA markers and discovery of epilepsy-causing mutations provide a basis for refining the classification of epilepsies. Recent discoveries regarding the genetics surrounding certain epilepsy types (including Lafora's progressive myoclonic epilepsy, the severe myoclonic epilepsy of infancy of Dravet, and idiopathic generalized epilepsies) may be the beginning of a better understanding of how rare Mendelian epilepsy genes and their genetic architecture can explain some complexities of the common epilepsies.

Juvenile myoclonic epilepsy: linkage to chromosome 6p12 in Mexico families.

Juvenile myoclonic epilepsy is a common subtype of idiopathic epilepsy accounting for 4-11% of all epilepsies. We reported previously significant evidence of linkage between chromosome 6p12-11 microsatellites and the clinical epilepsy and EEG traits of JME families from Belize and Los Angeles. To narrow the JME region, we ascertained and genotyped 31 new JME families from Mexico using a later generation of Généthon microsatellites. Two point linkage analyses obtained significant Z(max) values of 3.70 for D6S1573 and 2.65 for D6S1714 at theta(m = f) = 0.10, and 3.49 for D6S465, 2.11 for D6S1960 at theta(m = f) = 0.05 assuming autosomal dominant inheritance with 70% age-dependent penetrance. Multipoint LOD score curve peaked at 4.21 for D6S1573. Haplotype and recombination analysis reduced the JME region to 3.5 cM flanked by D6S272 and D6S1573. These results provide confirmatory evidence that a major susceptibility gene for JME exists in chromosome 6p12 in Spanish-Amerinds of Mexico.

Identification and mutational analysis of candidate genes for juvenile myoclonic epilepsy on 6p11-p12: LRRC1, GCLC, KIAA0057 and CLIC5.

Juvenile myoclonic epilepsy (JME) is one of the most frequent hereditary epilepsies characterized by myoclonic and tonic-clonic convulsions beginning at 8-20 years of age. Genetic studies have revealed four major chromosomal loci on 6p21.3, 6p11-12, 6q24, and 15q14 as candidate regions harboring genes responsible for JME. Previously we reported the region on 6p11-p12 (EJM1), and here we report the identification and mutational analysis of candidate genes for EJM1. One of those is a leucine-rich repeat-containing 1 (LRRC1) gene that is composed of 14 exons and codes for 524 amino acid residues. In Northern analysis, 7 kb transcripts of LRRC1 gene were detected in multiple tissues, most strongly, in heart, lung, and kidney. Mutation analysis of LRRC1 gene in 20 JME patients from ten families revealed one nucleotide substitution that lead to amino acid exchange (c.577 A>G; Ile193Val). This variation, however, did not co-segregate with the disease phenotype. We further performed mutational analyses of CLIC5, KIAA0057 and GCLC genes in or flank to the EJM1 region. These analyses did not provide any evidences that these genes are responsible for the JME phenotype, and suggested that these may not be the EJM1 gene.

Novel polymorphisms in the promoter region of the neurotrophin-3 gene and their associations with schizophrenia.

Based on the neurodevelopmental hypothesis in the etiology of schizophrenia, neurotrophic factors may be involved in the pathogenesis of the illness. We searched for polymorphisms in the promoter region of the neurotrophin-3 (NTF3) gene by using denaturing high performance liquid chromatography (DHPLC). Six single nucleotide polymorphisms (SNPs) were found. When these polymorphisms were examined for association with schizophrenia, a weakly significant difference was observed in the genotype distribution of the G/- 3004/A polymorphism between 184 schizophrenics and 185 controls (P < 0.05), although no statistically significant association was detected in a family-based sample of 50 trios (schizophrenics and their parents). With respect to the other polymorphisms, there was no significant association with schizophrenia. The G/- 3004/A polymorphism was in linkage disequilibrium with the CA repeat polymorphism in the first intron of the NTF3 gene. When haplotype-based analysis was performed, an increased frequency of the haplotype containing the G(- 3004) and the "A3" ([CA]23) alleles was observed for the schizophrenics compared to controls. Our results suggest that the G(- 3004)-A3 haplotype has a modest effect of giving susceptibility to schizophrenia.