Biotransformation and detoxification of tetrabromobisphenol A by white-rot fungus Phanerochaete sordida YK-624.

The bulky phenolic compound tetrabromobisphenol A (TBBPA) is a brominated flame retardant used in a wide range of products; however, it diffuses into the environment, and has been reported to have toxic effects. Although it is well-known that white-rot fungi degrade TBBPA through ligninolytic enzymes, no other metabolic enzymes have yet been identified, and the toxicity of the reaction products and their risks have not yet been examined. We found that the white-rot fungus Phanerochaete sordida YK-624 converted TBBPA to TBBPA-O-ß-D-glucopyranoside when grown under non-ligninolytic-enzyme-producing conditions. The metabolite showed less cytotoxicity and mitochondrial toxicity than TBBPA in neuroblastoma cells. From molecular biological and genetic engineering experiments, two P. sordida glycosyltransferases (PsGT1c and PsGT1e) that catalyze the glycosylation of TBBPA were newly identified; these enzymes showed dramatically different glycosylation activities for TBBPA and bisphenol A. The results of computational analyses indicated that the difference in substrate specificity is likely due to differences in the structure of the substrate-binding pocket. It appears that P. sordida YK-624 takes up TBBPA, and reduces its cytotoxicity via these glycosyltransferases.

Amide compound synthesis by adenylation domain of bacillibactin synthetase.

The adenylation domain of nonribosomal peptide synthetase (NRPS) is responsible for the selective substrate recognition and its activation (as an acyl-O-AMP intermediate) during ATP consumption. DhbE, a stand-alone adenylation domain, acts on an aromatic acid, 2,3-dihydroxybenzoic acid (DHB). This activation is the initial step of the synthesis of bacillibactin that is a high-affinity small-molecule iron chelator also termed siderophore. Subsequently, the activated DHB is transferred and attached covalently to a peptidyl carrier protein domain via a thioester bond. Adenylation domains belong to the superfamily of adenylate-forming enzymes including acetyl-CoA synthetase, acyl-CoA synthetase and firefly luciferase. We previously reported a novel N-acylation reaction for an acyl-CoA synthetase (AcsA) that originally catalyzes the formation of a thioester bond between an acid and CoA, yielding acyl-CoA. This novel reaction was also confirmed for acetyl-CoA synthetase and firefly luciferase, but not yet for an adenylation domain. Here, we for the first time demonstrated the synthesis of N-acyl-L-cysteine by a stand-alone adenylation domain, DhbE. When DHB and L-cysteine were used as substrates of DhbE, N-DHB-L-cysteine was formed. A Vmax value of 0.0156±0.0008 units mg-1 and Km values of 150±18.3 mM for L-cysteine and 0.0579±0.0260 mM for DHB were obtained in this novel reaction. Furthermore, DhbE synthesized N-benzoyl-L-cysteine when benzoic acid and L-cysteine were used as substrates. Through the N-acylation reaction of DhbE, we also succeeded in the synthesis of N-aromatic acyl compounds that have never previously been reported to be produced by this enzymatic method.

Influence of cytological stains on comparative genomic hybridization analysis for DNA extracted from cytological smears.

In the present study, we investigated the influence of cytological stains in analyzing DNA extracted from cytological slides by comparative genomic hybridization (CGH). Multiple imprint cytological slides were prepared for fresh-frozen breast cancer tissue samples and the slides were stained by three staining methods for each sample. Under microscopic observation, cancer cells were selectively microdissected from the slides and forwarded to DNA extraction, whole genome amplification, and CGH analysis. CGH was successfully performed for all methylgreen-stained and May-Grunwald-Giemsa (MGG)-stained cytological smear slides, but for two Papanicolaou (PAP)-stained slides. The number of chromosomal imbalances detected were 5-10 in methylgreen-stained slides and 5-9 in MGG-stained slides. The chromosomal imbalances resemble each other between methylgreen-stained and MGG-stained slides. The present study indicates that the MGG stain is preferred to the PAP stain for the purpose of cytogenetical analysis by CGH for DNA extracted from cytological smear slides.

Proton pump inhibitors improve acid-related dyspepsia in gastroesophageal reflux disease patients.

It has been reported that proton pump inhibitors are more effective than H2 receptor antagonists in patients with functional dyspepsia. Dyspeptic symptoms that respond to proton pump inhibitors are classified as acid-related dyspepsia. A new questionnaire for assessing gastroesophageal reflux disease (GERD), the Frequency Scale for Symptoms of GERD, covers the 12 most common symptoms of GERD patients. A quantitative assessment of the changes of reflux symptoms and acid-related dyspepsia was made in GERD patients receiving proton pump inhibitor therapy. Sixty-eight GERD patients receiving proton pump inhibitor therapy completed the questionnaire before and after treatment for 8 weeks. There is a significant positive correlation between reflux symptoms and acid-related dyspepsia before and after therapy (r = 0.569 and r = 0.569; both P's < 0.001) and acid-related dyspepsia in patients with both nonerosive and erosive GERD. We conclude that GERD patients suffer not only from reflux symptoms, but also from acid-related dyspepsia, and proton pump inhibitors improve both types of symptoms.

Sp1 is a co-activator with Ets-1, and Net is an important repressor of the transcription of CTP:phosphocholine cytidylyltransferase alpha.

Phosphatidylcholine biosynthesis via the CDP-choline pathway is primarily regulated by CTP:phosphocholine cytidylyltransferase (CT) encoded by the Pcyt1a and Pcyt1b genes. Previously, we identified an Ets-1-binding site located at -49/-47 in the promoter of Pcyt1a as an important transcriptional element involved in basal CTalpha transcription (Sugimoto, H., Sugimoto, S., Tatei, K., Obinata, H., Bakovic, M., Izumi, T., and Vance, D. E. (2003) J. Biol. Chem. 278, 19716-19722). In this study, we determined whether or not there were other important elements and binding proteins for basal CTalpha transcription in the Pcyt1a promoter, and if other Ets family proteins bind to the Ets-1-binding site. The results indicate the formation of a ternary complex with Ets-1 binding at -49/-47 and Sp1 binding at -58/-54 of the Pcyt1a promoter that is important for activating CTalpha transcription. When nuclear extracts of COS-7 cells expressing various Ets family repressors were incubated with DNA probes, binding of Net to the probes was observed. Net dose-dependently depressed the promoter-luciferase activity by 98%, even when co-expressed with Ets-1. RNA interference targeting Net caused an increase of endogenous CTalpha mRNA. After synchronizing the cell cycle in NIH3T3 cells, CTalpha mRNA increased at the S-M phase corresponding to an increase of Ets-1 mRNA and a decrease of Net mRNA. These results indicated that Net is an important endogenous repressor for CTalpha transcription.

Diagnosis of gastroesophageal reflux disease using a new questionnaire.

BACKGROUND AND AIM: An early and accurate evaluation by a general practitioner is needed to screen out non-gastroesophageal reflux disease (GERD) patients. A recent questionnaire (QUEST) highlighted problems with specificity and complexity, so the aim of the present study was to design a simplified questionnaire. METHODS: When admitted to hospital to undergo an upper gastrointestinal endoscopy for suspected GERD, 333 patients completed a 50-item questionnaire requiring 'yes/no' answers to different combinations of questions relating to symptoms of upper gastrointestinal tract conditions (e.g. GERD, ulcers and functional dyspepsia) and psychosomatic symptoms. The endoscopic diagnosis was then correlated with the rate of positive answers to each question. RESULTS: Based on the analysis of the 50 items, the 8-10 questions most often answered affirmatively by each of the GERD and non-GERD groups were chosen for the simplified questionnaire. Three draft questionnaires were compiled. After calculating the sensitivity, specificity and accuracy in relation to the diagnosis of GERD and other conditions, it was found that questionnaire B (selection of persons answering 'yes' to at least one of questions 1-5 and exclusion of persons answering 'yes' to at least three of questions 7-10) had a high sensitivity, high specificity and low false positive rate. CONCLUSION: A novel questionnaire was developed. It was designed to detect the symptoms of GERD while simultaneously excluding non-GERD patients. This simplified nine-item simplified questionnaire had a sensitivity of 79.8%, a specificity of 53.6% and an accuracy of 63.4%.

Development and evaluation of FSSG: frequency scale for the symptoms of GERD.

BACKGROUND: The aim of this study was to produce a simplified questionnaire for evaluation of the symptoms of gastroesophageal reflux disease (GERD). METHODS: A total of 124 patients with an endoscopic diagnosis of GERD completed a 50-part questionnaire, requiring only "yes" or "no" answers, that covered various symptoms related to the upper gastrointestinal tract, as well as psychosomatic symptoms. The 12 questions to which patients most often answered "yes" were selected, and were assigned scores (never = 0; occasionally = 1; sometimes = 2; often = 3; and always = 4) to produce a frequency scale for symptoms of GERD (FSSG). Sensitivity, specificity, and accuracy of the FSSG questionnaire were evaluated in another group of patients with GERD and non-GERD. The usefulness of this questionnaire was evaluated in 26 other GERD patients who were treated with proton pump inhibitors for 8 weeks. RESULTS: When the cutoff score was set at 8 points, the FSSG showed a sensitivity of 62%, a specificity of 59%, and an accuracy of 60%, whereas a cutoff score of 10 points altered these values to 55%, 69%, and 63%. The score obtained using the questionnaire correlated well with the extent of endoscopic improvement in patients with mild or severe GERD. CONCLUSIONS: This new questionnaire is useful for the objective evaluation of symptoms in GERD patients.

Identification of Ets-1 as an important transcriptional activator of CTP:phosphocholine cytidylyltransferase alpha in COS-7 cells and co-activation with transcriptional enhancer factor-4.

Phosphatidylcholine biosynthesis via the CDP-choline pathway is primarily regulated by CTP:phosphocholine cytidylyltransferase (CT). Transcriptional enhancer factor-4 (TEF-4) enhances the transcription of CTalpha in COS-7 cells by interactions with the basal transcription machinery (Sugimoto, H., Bakovic, M., Yamashita, S., and Vance, D.E. (2001) J. Biol. Chem. 276,12338-12344). To identify the most important transcription factor involved in basal CTalpha transcription, we made CTalpha promoter-deletion and -mutated constructs linked to a luciferase reporter and transfected them into COS-7 cells. The results indicate that an important site regulating basal CTalpha transcription is -53/-47 (GACTTCC), which is a putative consensus-binding site of Ets transcription factors (GGAA) in the opposite orientation. Gel shift analyses indicated the existence of a binding protein for -53/-47 (GACTTCC) in nuclear extracts of COS-7 cells. When anti-Ets-1 antibody was incubated with the probe in gel shift analyses, the intensity of the binding protein was decreased. The binding of endogenous Ets-1 to the promoter probe was increased when TEF-4 was expressed; however, the amount of Ets-1 detected by immunoblotting was unchanged. When cells were transfected with Ets-1 cDNA, the luciferase activity of CTalpha promoter constructs was greatly enhanced. Co-transfection experiments with Ets-1 and TEF-4 showed enhanced expression of reporter constructs as well as CTalpha mRNA. These results suggest that Ets-1 is an important transcriptional activator of the CTalpha gene and that Ets-1 activity is enhanced by TEF-4.