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1.
J Werwath HA Arfmann DH Pieper KN Timmis RM Wittich 《Canadian Metallurgical Quarterly》1998,180(16):4171-4176
A 4,103-bp long DNA fragment containing the structural gene of a gentisate 1,2-dioxygenase (EC 1.13.11.4), gtdA, from Sphingomonas sp. strain RW5 was cloned and sequenced. The gtdA gene encodes a 350-amino-acid polypeptide with a predicted size of 38.85 kDa. Comparison of the gtdA gene product with protein sequences in databases, including those of intradiol or extradiol ring-cleaving dioxygenases, revealed no significant homology except for a low similarity (27%) to the 1-hydroxy-2-naphthoate dioxygenase (phdI) of the phenanthrene degradation in Nocardioides sp. strain KP7 (T. Iwabuchi and S. Harayama, J. Bacteriol. 179:6488-6494, 1997). This gentisate 1,2-dioxygenase is thus a member of a new class of ring-cleaving dioxygenases. The gene was subcloned and hyperexpressed in E. coli. The resulting product was purified to homogeneity and partially characterized. Under denaturing conditions, the polypeptide exhibited an approximate size of 38.5 kDa and migrated on gel filtration as a species with a molecular mass of 177 kDa. The enzyme thus appears to be a homotetrameric protein. The purified enzyme stoichiometrically converted gentisate to maleylpyruvate, which was identified by gas chromatography-mass spectrometry analysis as its methyl ester. Values of affinity constants (Km) and specificity constants (Kcat/Km) of the enzyme were determined to be 15 microM and 511 s-1 M-1 x 10(4) for gentisate and 754 microM and 20 s-1 M-1 x 10(4) for 3, 6-dichlorogentisate. Three further open reading frames (ORFs) were found downstream of gtdA. The deduced amino acid sequence of ORF 2 showed homology to several isomerases and carboxylases, and those of ORFs 3 and 4 exhibited significant homology to enzymes of the glutathione isomerase superfamily and glutathione reductase superfamily, respectively. 相似文献
2.
"Pseudomonas azotocolligans" ATCC 12417T (T = type strain), which was described as a diazotrophic bacterium, was reinvestigated to clarify its taxonomic position. 16S ribosomal DNA sequence comparisons demonstrated that this strain clusters phylogenetically with species of the genus Sphingomonas and represents a new species. The results of investigations of the fatty acid patterns, polar lipid profiles, and quinone system supported this placement. The substrate utilization profile and biochemical characteristics displayed no obvious similarity to the characteristics of any previously described species of the genus Sphingomonas. The new name Sphingomonas trueperi is proposed on the basis of these results and previously published data for the G + C content of the genomic DNA and the polyamine pattern. 相似文献
3.
Four strains of an unknown coryneform bacterium were isolated in pure culture from females with urinary tract infections. Strong urease activity and the ability to slowly ferment maltose but not glucose were the most significant phenotypic features of this catalase-positive, nonmotile, nonlipophilic, rod-shaped bacterium which served to distinguish it from all other presently defined coryneform bacteria. Chemotaxonomic investigations demonstrated that the unknown bacterium belonged to the genus Corynebacterium. Comparative 16S rRNA gene sequence analysis revealed that the isolates were genealogically identical and represented a new subline within the genus Corynebacterium, for which the designation Corynebacterium riegelii sp. nov. is proposed. The type strain of Corynebacterium riegelii is CCUG 38180 (DSM 44326, CIP 105310). 相似文献
4.
M Nimtz V Wray T Domke B Brenneke S H?ussler I Steinmetz 《Canadian Metallurgical Quarterly》1997,250(2):608-616
A recently described water-soluble exopolysaccharide of Burkholderia pseudomallei recognized by the IgG 1 monoclonal antibody 3015 [Steinmetz, I., Rohde, M. & Brenneke, B. (1995) Infect. Immun. 63, 3959-3965] was isolated by repetitive ethanol-precipitation steps and by anion-exchange chromatography. The structure of the polysaccharide was determined by a combination of chemical-derivatization and mass-spectrometric techniques (compositional and methylation analysis, GC/MS, and electrospray-ionization-MS/MS of reduced and permethylated hydrolytic fragments), and two-dimensional 1H-NMR methods (COSY, TOCSY and NOESY) and confirmed by isolation and structural characterization of the depolymerized repeating unit of the polysaccharide. The combined structural data established a linear tetrasaccharide repeating unit consisting of three galactose residues, one bearing a 2-linked O-acetyl group, and a 3-deoxy-D-manno-2-octulosonic acid residue. [-->3)-beta-D-Galp2Ac-(1-->4)-alpha-D-Galp-(1-->3)-beta-D-Galp-(1- ->5)-beta-Kdo-(2-->]n 相似文献
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6.
The problem of electromagnetic tomographic reconstruction is approached in terms of the derivation of a minimum norm interpolator, incorporating a priori knowledge gained from a previous reconstruction. An algorithm is suggested for the initial estimate and both images are compared to that of bilinear interpolation. 相似文献
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8.
Bacillus sp.S-1 alkaline pullulanase (AP) exists in two forms: a precursor form (PUL-Ia, M(r) 180,000) and a processed form (PUL-Ib, M(r) 140,000). PUL-Ia was accumulated intracellularly in large amounts, and PUL-Ib was detected in both the membrane fraction and the fraction trapped between the cytoplasmic membrane and the cell wall. Two forms of AP were purified to homogeneity and their properties were compared with previously purified PUL-E (140 kDa). PUL-Ib showed similar properties, such as the M(r) value, the pI value (5.7), specific activity, substrate specificity, the NH2-terminal amino acid sequence (Phe-Leu-Asn-Met-Ser), and biophysical characters. However, in the case of PUL-Ia, even though the patterns of optimum pH and temperature, substrate specificity, and enzyme inhibition and activation were similar to those for PUL-Ib and PUL-E, the M(r) value and the pI value (5.97) were different. Furthermore, the NH2-terminal amino acid sequence of PUL-Ia was completely blocked, and the stabilities over pH and temperature ranges were decreased. The catalytic activities of PUL-Ia were distinguishable in the Km and Vmax values for various substrates and in the specific activity (71.4 U/mg) for pullulan hydrolysis. PUL-Ib and PUL-E showed 10-fold higher specific activities (744.6 for PUL-E and 736 for PUL-Ib) than PUL-Ia. However, PUL-Ia was immunologically identical to PUL-E and PUL-Ib. Therefore, it was concluded that PUL-Ib and PUL-E are the same form of the enzyme, suggesting that PUL-Ia is initially synthesized and proteolytically processed to the mature form of PUL-E. On the other hand, the translocation of AP required processing of the AP protein and the processing facilitated enzymatic activation and stabilization through a complete conformational change, resulting in an increase in affinity for substrates of PUL-E. 相似文献
9.
M Gutiérrez Triguero Y Escamilla Carpintero T Martínez Guirado M Bodoque Cano B Scola Yurrita M Fernández-Vega 《Canadian Metallurgical Quarterly》1998,49(8):667-670
A 58-year-old male was admitted to our hospital with a preliminary diagnosis of bacterial endocarditis. After admission, echocardiography indicated the presence of vegetation-like tissues on both the left coronary cusp and the anterior mitral leaflet, although retrograde aortography two months earlier hadn't indicated an abnormal finding on the aortic cusp. The vegetation-like tissues had gradually enlarged despite the administration of antibiotics at another hospital, and aortic and mitral regurgitation had become severe. We decided to perform replacements of the aortic and mitral valves on the day of admission. During the operation, the aortic valve was found not to have vegetation, but an aneurysmal pouch on the left coronary cusp. It was supposed that either bacterial endocarditis or catheter injury had made a part of the aortic cusp weak and intolerant of diastolic pressure gradient, and as a result, the weakened part of the cusp progressively dilated into the left ventricle forming an aneurysmal pouch. To our knowledge, there have been only two previous reports of an aneurysmal pouch on the aortic cusp documented in the literature. 相似文献
10.
A site-specific endonuclease which recognizes the sequence 5'-CCTNAGG-3' was purified to homogeneity from the thermophilic strain Bacillus sp. R7. The endonuclease (BspR7I) is monomeric protein with an apparent molecular weight of 37 kD. The enzyme is active over a wide range of NaCl concentrations, pH, and temperatures. BspR7I cleaves DNA substrates according to the scheme: 5'-CC decreases TNAGG-3' 3'-GGANT increases CC-5', hence the endonuclease represents an isoschizomer of Bsu361. 相似文献
11.
SM de Matta FD Monache F Ferrari GB Marini-Bettolo 《Canadian Metallurgical Quarterly》1976,31(7):527-535
The direct and indirect effects of staphylococcal enterotoxins A and C on the flux of water, sodium, and potassium have been studied in paired Thiry Vella fistulae in dogs. Administration of toxin resulted in a significant decrease in absorption, both in the loop to which the toxin had been administered and its pair. This decrease in absorption was associated with a decrease in movement out of the lumen, movement into the lumen remaining relatively unchanged. The mechanism of action of staphylococcal enterotoxins is discussed, and comparisons made with other enterotoxins. 相似文献
12.
The authors report the case of a suicide pact of two men (22 and 24 years old), which exhibits extraordinary circumstances concerning the personal profile and the suicide procedures. Both had a psychiatric history and were found dead near their severely damaged car, with gaggs in their mouth and a rope tightened around the neck and fixed to the car. Extra gas cans had also been placed in the car. Autopsy confirmed death due to severe trauma and rope strangulation. Toxicological analysis of the blood revealed codeine, dihydrocodeine, paracetamol in high, doxepine in lethal concentrations. According to police investigations, which has been confirmed by medical examination, both men had made arrangements for their suicide selecting a range of methods to kill themselves. 相似文献
13.
I Hayata M Oshimura MJ Marinello RM Bannerman AA Sandberg 《Canadian Metallurgical Quarterly》1976,13(4):320-323
Because of multiple abnormalities in her children, a young mother was investigated and shown to have a 47,XXX chromosome constitution. Additional C group chromosomes without visible centromeric constrictions were found in a number of cells from the peripheral blood, and using C and Q banding techniques these chromosomes were identified as X chromosomes. Analysis of the banding karyotypes of 300 cells revealed that the acentric X chromosomes had the ability to replicate and that this replication was associated with non-disjunction leading to aneuploid cells. Even though cultured skin cells did not have acentric or extra chromosomes in addition to the triple-X, examination of buccal mucosa cells for the presence of X-bodies suggested that the phenomenon of non-disjunction was present in the epithelial cells of the patient. In addition to the X without a visible centromeric constriction, either acentric D or E chromosomes were found. The data suggest that a functional defect in the cells per se is responsible for the appearance of the acentric chromosomes. 相似文献
14.
Experiments on the development of a vaccine against staphylococcal mastitis were carried out in ewes. The vaccine (Spanish patent no. 9200223) has the following components: (i) inactivated (formalinized) bacteria (Staphylococcus aureus and a coagulase-negative staphylococcal species. Staphylococcus simulans) and S. aureus toxoid in presence of an adjuvant (dextran sulfate, Mw 500,000); and (ii) S. aureus exopolysaccharide included within liposomes. High serum antibody titres were obtained against whole cells from Staphylococcus aureus, Staphylococcus simulans, Staphylococcus hyicus and Staphylococcus epidermidis strains. However, there was no response to cells from Staphylococcus warneri and Staphylococcus chromogenes strains. An immune response (serum IgG) against the inoculated exopolysaccharide was obtained when > or = 20 micrograms of exopolysaccharide were included in liposomes and when > or = 20 mg of exopolysaccharide were adjuvanted with dextran sulfate instead of liposomes. For experimental infection assays, ewes were vaccinated during pregnancy and challenged either with a low virulence S. simulans strain or with a highly virulent S. aureus strain. In these assays, the incidence of S. simulans subclinical mastitis and of S. aureus acute mastitis was significantly lower in vaccinated animals than in unvaccinated controls. Specifically, on challenge with S. simulans, two out of 14 glands became infected among the vaccinated animals and nine out of ten glands in the unvaccinated group (p < 0.001). On challenge with S. aureus, no protection was detected when component (ii) was omitted from the vaccine; nine out of ten animals developed mastitis (two mild, two moderate and five severe).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
15.
Autoimmune hepatitis type 1 is known to progress insidiously and in many cases cirrhosis is already established at the first presentation of symptoms. It affects mostly females, with peaks of incidence around 10 and 50 years of age. Subfulminant hepatic failure is an unusual initial form of presentation of AIH type 1 and it was observed in three post-pubertal female patients. Rapid disease evolution or no response to immunosuppressive therapy led to liver transplantation in all patients. Two did not have cirrhosis, and the third had focal cirrhosis. The occurrence of the unusual subfulminant form of autoimmune hepatitis in three latepubertal girls (Tanner V) suggests that estrogen may play a role in the severity of the disease. 相似文献
16.
Recurrent ascending myelitis: an unusual presentation of herpes simplex virus type 1 infection 总被引:1,自引:0,他引:1
We report on a healthy female with a unique relapsing transverse myelitis accompanied by herpes simplex virus type 1 (HSV-1) infection. Magnetic resonance imaging showed cord enlargement and increased signal intensity on T1-weighted image with gadolinium enhancement from T-4 to T-10 during the first attack and from C-1 to C-2 during the second episode. She was not diagnosed during the first attack. During the second episode, laboratory studies disclosed IgM and IgG antibodies to HSV at the outset with greater than fourfold increases in antibody levels in the serum and cerebrospinal fluid (CSF). Cells cultured from the CSF were positive for HSV-1 according to the immunofluorescence method. The presence of HVS-1 DNA in CSF was documented by polymerase chain reaction (PCR) technique. Acyclovir was given with a partial recovery. We anticipate that PCR assay of CSF will assist early diagnosis of herpetic central nervous system disorders. 相似文献
17.
D Low JA Ahlgren D Horne DJ McMahon CJ Oberg JR Broadbent 《Canadian Metallurgical Quarterly》1998,64(6):2147-2151
Recent work by our group has shown that an exopolysaccharide (EPS)-producing starter pair, Streptococcus thermophilus MR-1C and Lactobacillus delbrueckii subsp. bulgaricus MR-1R, can significantly increase moisture retention in low-fat mozzarella (D. B. Perry, D. J. McMahon, and C. J. Oberg, J. Dairy Sci. 80:799-805, 1997). The objectives of this study were to determine whether MR-1C, MR-1R, or both of these strains are required for enhanced moisture retention and to establish the role of EPS in this phenomenon. Analysis of low-fat mozzarella made with different combinations of MR-1C, MR-1R, and the non-EPS-producing starter culture strains S. thermophilus TA061 and Lactobacillus helveticus LH100 showed that S. thermophilus MR-1C was responsible for the increased cheese moisture level. To investigate the role of the S. thermophilus MR-1C EPS in cheese moisture retention, the epsE gene in this bacterium was inactivated by gene replacement. Low-fat mozzarella made with L. helveticus LH100 plus the non-EPS-producing mutant S. thermophilus DM10 had a significantly lower moisture content than did cheese made with strains LH100 and MR-1C, which confirmed that the MR-1C capsular EPS was responsible for the water-binding properties of this bacterium in cheese. Chemical analysis of the S. thermophilus MR-1C EPS indicated that the polymer has a novel basic repeating unit composed of D-galactose, L-rhamnose, and L-fucose in a ratio of 5:2:1. 相似文献
18.
Perea Manuel; Du?abeitia Jon Andoni; Carreiras Manuel 《Canadian Metallurgical Quarterly》2008,34(1):237
Letter identities and number identities are usually thought to imply different cortical mechanisms. Specifically, the left fusiform gyrus responds more to letters than to digits (T. A. Polk et al., 2002). However, a widely circulated statement on the internet illustrates that it is possible to use numbers (leet digits) as parts of words, 4ND TH3 R35ULT1NG S3NT3NC3 C4N B3 R34D W1TH0UT GR34T 3FF0RT. Two masked priming lexical decision experiments were conducted to determine whether leet digits produce (automatic) lexical activation. Results showed that words are identified substantially faster when they are preceded by a masked leet word (M4T3R14L-MATERIAL) than when they are preceded by a control condition with other letters or digits. In addition, there was only a negligible advantage of the identity condition over the related leet condition. This leet-priming effect is not specific to numbers: A prime in which leet digits are replaced by letter-like symbols (MΔT?!ΔL-MATERIAL) facilitates word processing to the same degree as an identity prime. Therefore, the cognitive system regularizes the shape of the leet digits and letter-like symbols embedded in words with very little cost. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
19.
E Longchampt G Cariou M Arborio E Skrobala JP Brouland B Cochand-Priollet 《Canadian Metallurgical Quarterly》1998,18(5):418-421
Malignant mixed müllerian tumors (MMMT) of the ovary are rare, aggressive and rapidly progressive tumors. According to the available literature, the presence of metastatic disease rarely permits long term survival. We report on a 64-year old patient with stage IV ovarian MMMT who achieved a surgically-documented complete response (CR) after 6 cycles of carboplatin, mesna, ifosfamide, cis-platin. Pelvic recurrence was diagnosed 14 months later; the patient received 6 cycles of the same regimen used as first-line chemotherapy which resulted in a second complete response lasting for 4 months. The patient died 37 months after initial diagnosis due to intestinal occlusion. In the current case Ca 125 was significantly increased at clinical presentation of disease but not at the time of recurrence. 相似文献