Overall analyses of the reactions catalyzed by acetohydroxyacid synthase/acetolactate synthase using a precolumn derivatization-HPLC method.

A precolumn derivatization-HPLC method using 2,4-dinitrophenylhydrazine and 4-nitro-o-phenylenediamine as respective labeling reagents for comprehensive analyses of the reactions catalyzed by acetohydroxyacid synthase (AHAS)/acetolactate synthase (ALS) is developed and evaluated in this research. Comparison with the classic Bauerle' UV assay which can analyze the enzymes only through measurement of acetoin production, the HPLC method shows advantages because it can analyze the enzymes not only via determination of consumption of the substrate pyruvate, but also via measurement of formation of the products including acetoin, 2,3-butanedione, and acetaldehyde in the enzymatic reactions. Thus the results deduced from the HPLC method can reflect the trait of each enzyme in a more precise manner. As far as we know, this is the first time that the reactions mediated by AHAS/ALS using pyruvate as a single substrate are globally analyzed and the features of the enzymes are properly discussed.

Brachybacterium huguangmaarense sp. nov., isolated from Lake sediment.

A Gram-stain positive strain, M1T, was isolated from the sediment of Maar Lake in Zhanjiang, Guangdong Province, China. The diagnostic cell-wall diamino acid was meso-diaminopimelic acid, and mycolic acids were not detected. The polar lipid profile of strain M1T consisted of diphosphatidylglycerol, phosphatidylglycerol, an unidentified phospholipid and an unknown glycolipid. The predominant quinone was MK-7, with MK-6 as a minor component. The major fatty acids were anteiso-C15:0 and anteiso-C17:0, with iso-C18:0 as a minor component. The DNA G+C content of the genomic DNA was 71.0 mol%. 16S rRNA gene sequence analysis showed that strain M1T belongs to the family Dermabacteraceae, sharing highest sequence similarity with Brachybacterium nesterenkovii JCM 11648T (98.1%). Furthermore, a combination of DNA-DNA relatedness and physiological and biochemical properties indicated that the novel strain could be readily distinguished from its closest phylogenetic relatives. On the basis of these phenotypic and genotypic data, strain M1T represents a novel species of the genus Brachybacterium, for which the name Brachybacterium huguangmaarense sp. nov. is proposed. The type strain is M1T (=CCTCC AB 2012866T=DSM 26370T).

Paracoccus siganidrum sp. nov., isolated from fish gastrointestinal tract.

A bacterial strain, designated M26(T), was isolated from a fish gastrointestinal tract, collected from Zhanjiang Port, South China. 16S rRNA gene sequence analysis indicated that strain M26(T) belongs to the subclass α-Proteobacteria, being related to the genus Paracoccus, and sharing highest sequence similarity with Paracoccus alcaliphilus JCM 7364(T) (98.1 %), Paracoccus huijuniae FLN-7(T) (97.3 %), Paracoccus stylophorae KTW-16(T) (97.1 %) and Paracoccus seriniphilus DSM 14827(T) (96.9 %). The major quinone was determined to be ubiquinone Q-10, with Q-9 and Q-8 as minor components. The major fatty acid was identified as C18:1ω7c, with smaller amounts of C18:0 and C16:0. The G+C content of the genomic DNA was determined to be 64.3 mol%. The DNA hybridization value between strain M26(T) and the most closely related type strain, P. alcaliphilus, was 29.0 ± 1.0 %. The results of physiological and biochemical tests and low DNA-DNA relatedness showed that the strain could be readily distinguished from closely related species. On the basis of these phenotypic and genotypic data, strain M26(T) is concluded to represent a novel species of the genus Paracoccus, for which the name Paracoccus siganidrum sp. nov. is proposed. The type strain is M26(T) (=CCTCC AB 2012865(T) = DSM 26381(T)).

[18F-FDG imaging by coincidence circuit SPECT with low-dose CT in preoperative assessment of pulmonary lesions].

OBJECTIVE: To assess the clinical diagnostic value of 18F-FDG imaging by coincidence circuit SPECT with low-dose CT in differential diagnosis of pulmonary lesions and mediastinal lymph node involvement, which can not be definitely diagnosed based on regular CT image in patients with non-small-cell lung cancer (NSCLC). METHODS: By using GE-Millennium VG with Hawkeye, 18F-FDG imaging was carried out in 48 patients with suspected lung cancer. Clinical value of 18F-FDG imaging for diagnosing malignancy was evaluated through comparison with the final pathological results. Mediastinal lymph node involvement was also assessed through lesion-by-lesion comparison with pathologic results in 74 lymph node regions from 24 patients. RESULTS: Final pathologic diagnoses of these patients were 36 malignancies consisting of 20 adenocarcinomas, 12 squamous cell carcinomas, 3 small cell carcinomas and I large cell carcinoma; 12 benign tumors including 6 pneumonias, 2 tuberculosis, 2 hamatomas, 1 cyst and 1 neurofibroma. Of 48 patients, uptake of 18F-FDG in the chest was found to be abnormal in 40. Correct diagnosis were made in 34 malignancies and 6 false positive lesions were excluded based on morphology and 18F-FDG uptake status of the lesion. There were 6 false positive and 2 false negative cases. Furthermore, extrathoracic metastases which were not showed on previous CT image in 4 patients including one in the adrenal gland and 3 in the bone were detected by 18F-FDG imaging. The sensitivity, specificity and accuracy of the 18F-FDG imaging for differentiating malignant tumor from benign was 94.4%, 50.0% and 83.3%, respectively. Squamous cell carcinoma was found to uptake more FDG than adenocarcinoma. For determination of mediastinal lymph node involvement, the sensitivity, specificity and accuracy of 18F-FDG imaging was 57.9% , 90.9% and 82.4%, respectively through lesion-by-lesion comparison; whereas, which was 61.5%, 81.8% and 70.8%, respectively, based on case-by-case comparison. CONCLUSION: 18F-FDG imaging by coincidence circuit SPECT with low-dose CT is quite helpful in differential diagnosis for patient with undetermined lesion on regular CT image, but it is limited for staging of lung cancer in the patients with non-small cell lung cancer.

[Determination of 14 trace elements in soybean and its products by atomic absorption spectrometry].

Fourteen trace elements in soybean and its products were determined by atomic absorption spectrometry. The effects of cinefaction temperature, cinefaction time, and the concentration of HNO3 as a digestion solution were investigated in detail. The effect of the concentration of SrCl2 on the determination of Ca and Mg was also studied. The results obtained show that the soybean and its products contain higher amounts of K, Na, Ca, Mg, Fe, Cu, Zn and Mn than other elements.