Molecular diagnosis makes a substantial contribution to precise diagnosis, subclassification, prognosis, and selection of therapy. Mutations in the PDS (SLC26A4) gene are known to be responsible for both Pendred syndrome and nonsyndromic hearing loss associated with enlarged vestibular aqueduct, and the molecular confirmation of the PDS gene has become important in the diagnosis of these conditions. In the present study, PDS mutation analysis confirmed that PDS mutations were present and significantly responsible in 90% of Pendred families, and in 78.1% of families with nonsyndromic hearing loss associated with enlarged vestibular aqueduct. Furthermore, variable phenotypic expression by the same combination of mutations indicated that these two conditions are part of a continuous category of disease. Interestingly, the PDS mutation spectrum in Japanese, including the seven novel mutations revealed by this study, is very different from that found in Caucasians. Of the novel mutations detected, 53% were the H723R mutation, suggesting a possible founder effect. Ethnic background is therefore presumably important and should be noted when genetic testing is being performed. The PDS gene mutation spectrum in Japanese may be representative of those in Eastern Asian populations and its elucidation is expected to facilitate the molecular diagnosis of a variety of diseases.
General rules for recording endoscopic findings of esophageal varices were initially proposed in 1980 and revised in 1991. These rules have widely been used in Japan and other countries. Recently, portal hypertensive gastropathy has been recognized as a distinct histological and functional entity. Endoscopic ultrasonography can clearly depict vascular structures around the esophageal wall in patients with portal hypertension. Owing to progress in medicine, we have updated and slightly modified the former rules. The revised rules are simpler and more straightforward than the former rules and include newly recognized findings of portal hypertensive gastropathy and a new classification for endoscopic ultrasonographic findings.
A recombinant butanol pathway composed of Clostridium acetobutylicum ATCC 824 genes, thiL, hbd, crt, bcd-etfB-etfA, and adhe1 (or adhe) coding for acetyl-CoA acetyltransferase (THL), beta-hydroxybutyryl-CoA dehydrogenase (HBD), 3-hydroxybutyryl-CoA dehydratase (CRT), butyryl-CoA dehydrogenase (BCD), butyraldehyde dehydrogenase (BYDH), and butanol dehydrogenase (BDH), under the tac promoter control was constructed and was introduced into Escherichia coli. The functional expression of these six enzymes was proved by demonstrating the corresponding enzyme activities using spectrophotometric, high performance liquid chromatography and gas chromatography analyses. The BCD activity, which was not detected in E. coli previously, was shown in the present study by performing the procedure from cell extract preparation to activity measurement under anaerobic condition. Moreover, the etfA and etfB co-expression was found to be essential for the BCD activity. In the case of BYDH activity, the adhe gene product was shown to have higher specificity towards butyryl-CoA compared to the adhe1 product. Butanol production from glucose was achieved by the highly concentrated cells of the butanologenic E. coli strains, BUT1 with adhe1 and BUT2 with adhe, under anaerobic condition, and the BUT1 and BUT2 strains were shown to produce 4 and 16-mM butanol with 6- and 1-mM butyrate as a byproduct, respectively. This study reports the novel butanol production by an aerobically pregrown microorganism possessing the genes of a strict anaerobe, Clostridium acetobutylicum.
FTLD-U is the most common variant of FTLD. FTLD, a heterogeneous syndrome characterized by progressive dementia, is caused by degeneration of the frontal and anterior temporal lobes, and is a leading cause of dementia in patients presenting before the age of 65 years (5). The pathogenesis of FTLD remains unknown. ALS is the most common motor neuron disease, characterized by progressive loss of motor neurons (6, 7). The pathogenesis of ALS remains undetermined although various hypotheses have been proposed: e.g. misfolded protein aggregates, mitochondrial dysfunction, glutamate toxicity, oxidative stress, disturbance of intracellular trafficking, and ER stress (8). About 10% of ALS cases occur in a genetically inherited manner.Post-translational modifications of TDP-43 including truncation, hyperphosphorylation, and ubiquitination are assumed to be linked to abnormal aggregation (1, 2). In particular, C-terminal fragments (CTFs) of TDP-43 are prone to form cytoplasmic aggregates (9 -11). Although it is apparent that cytoplasmic aggregates of TDP-43 are closely related to the pathogenesis of FTLD-U and ALS, it remains unknown how CTFs are generated and whether the aggregate formation of TDP-43 is a cause or a result of neuronal toxicity.Caspase activation has been observed in motor neurons of ALS (12-15) and neurons in FTLD patients (16). One possible mechanism underlying the generation of CTFs is the cleavage of TDP-43 by activated caspases. In reality, multiple studies have shown that TDP-43 is cleaved in a caspase-dependent manner and the resulting CTFs of TDP-43 are constituents in the inclusion bodies (17)(18)(19).Some clinical studies have suggested that the levels of TDP-43 are up-regulated in motor neurons of sporadic ALS patients, based on the finding that the levels of TDP-43 are up-regulated in cerebrospinal fluids (20)
LldR (CGL2915) from Corynebacterium glutamicum is a transcription factor belonging to the GntR family, which is typically involved in the regulation of oxidized substrates associated with amino acid metabolism. In the present study, the crystal structure of LldR was determined at 2.05-Å resolution. The structure consists of N- and C-domains similar to those of FadR, but with distinct domain orientations. LldR and FadR dimers achieve similar structures by domain swapping, which was first observed in dimeric assembly of transcription factors. A structural feature of Zn2+ binding in the regulatory domain was also observed, as a difference from the FadR subfamily. DNA microarray and DNase I footprint analyses suggested that LldR acts as a repressor regulating cgl2917-lldD and cgl1934-fruK-ptsF operons, which are indispensable for l-lactate and fructose/sucrose utilization, respectively. Furthermore, the stoichiometries and affinities of LldR and DNAs were determined by isothermal titration calorimetry measurements. The transcriptional start site and repression of LldR on the cgl2917-lldD operon were analysed by primer extension assay. Mutation experiments showed that residues Lys4, Arg32, Arg42 and Gly63 are crucial for DNA binding. The location of the putative ligand binding cavity and the regulatory mechanism of LldR on its affinity for DNA were proposed.
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