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Biomedical subjects

T Kusano

Publications and source records attributed to T Kusano.

At least 19 recordsLinked to original sources
PubMed1992

Molecular cloning of the gene encoding Thiobacillus ferrooxidans Fe(II) oxidase. High homology of the gene product with HiPIP.

The amino-terminal sequence of Thiobacillus ferrooxidans Fe(II) oxidase (linked to cytochrome c552) was determined, and the iro gene that encodes this enzyme was cloned using degenerate oligonucleotides as a probe. The DNA sequence of a region (856 base pairs) which encompasses the iro gene revealed that the enzyme was encoded by a 273-base pair open reading frame and consists of 90 amino acids, including a possible 37-residue signal sequence. The iro gene seems to be transcribed independently of any other gene because the transcriptional products are 0.45 and 0.6 kilobases in size. Current protein databases revealed that the iro gene product is a new member of the high redox potential iron sulfur proteins, which generally function in electron transport but do not show enzymatic activity.

Amino Acid Sequence↗
PubMed1992

Postoperative pyothorax.

Twenty-five cases of pyothorax occurred in a series of 1281 thoracotomies. Almost all cases of pyothorax without bronchopleural fistula were successfully treated by closed drainage and irrigation alone. On the other hand, patients with pyothorax and fistula who were treated only with closed drainage almost all had a poor outcome. When pyothorax with fistula was treated by closed drainage and irrigation followed by further procedures such as open window thoracostomy, muscle plombage and/or omentopexy, treatment was successful. It is concluded that pyothorax without fistula may be cured by closed drainage and irrigation alone, but that pyothorax with fistula requires operative intervention such as open window thoracostomy or omental flap as soon as possible.

Adolescent↗
PubMed1992

Rice dwarf phytoreovirus segment S12 transcript is tricistronic in vitro.

Sequence analysis revealed that rice dwarf phytoreovirus segment S12 is 1066 nucleotides long with a small out-of-phase, overlapping open reading frame (ORF) as well as a major ORF. The large ORF (positions 42 to 980) encodes 312 amino acids, while the small one (bases 313 to 591) encodes 92 amino acids with an additional in-frame AUG codon (positions 337-339) 24 nucleotides downstream from the first one. Transcripts from a full-length cDNA directed the in vitro synthesis of three polypeptides of 33 (considered to be translated from the long ORF), 8, and 7 kDa. Alteration of each of the two ATG codons on the small ORF demonstrated their involvement in the generation of the 8- and 7-kDa polypeptides. Although it is still unknown whether these proteins are expressed in vivo, the small ORF is shown to be conserved in S9s of two other members of the genus Phytoreovirus, rice gall dwarf virus and wound tumor virus, suggesting its common, important function.

Amino Acid Sequence↗
PubMed1992

Molecular analysis of rice dwarf phytoreovirus segment S1: interviral homology of the putative RNA-dependent RNA polymerase between plant- and animal-infecting reoviruses.

We have determined the complete nucleotide sequence of the largest segment S1 of rice dwarf phytoreovirus (RDV), a member of the family Reoviridae. S1 is 4423 nucleotides long with a segment-specific inverted repeat located adjacent to the conserved termini (5'GGCAAA---UGAU3'). A major open reading frame (bases 36 to 4367) on the S1 plus strand, which is preceded by a minicistron (bases 6 to 29), encodes the polypeptide (P1) consisting of 1444 amino acids with a M(r) of 164, 142. The sense-strand transcript derived from the full-length S1 cDNA, the minicistron of which was abolished, directed the synthesis of a polypeptide of 170 kDa in addition to smaller polypeptides in wheat germ extracts, and the 170-kDa product comigrated with the minor core protein in SDS-polyacrylamide gel. Thus, P1 is assumed to be localized in the viral core particle. The consensus sequence element conserved in RNA-dependent RNA polymerase is observed in the P1 amino acid sequence predicted from the nucleotide sequence. Based on the dendrogram established from the sequence alignment around the polymerase module region, and sequence identity within the alignment, P1 of plant-infecting RDV was evolutionarily compared with VP1, lambda 3, and VP1 of three other animal-infecting members of the family, rota-, reo-, and bluetongue viruses. Consequently, RDV S1 was shown to be more closely related to the rotavirus gene segment 1, in terms of molecular evolution, than the animal-infecting members are to one another.

Amino Acid Sequence↗
PubMed1992

Diaphragmatic cyst with elevated level of serum tissue polypeptide antigen.

A 58-year-old woman with a mesothelial cyst of the diaphragm showed high level of serum Tissue Polypeptide Antigen (TPA) and cyst fluid TPA. Mesothelial cells of the cyst may excrete TPA and TPA was accumulated in the cysts. The measurement of tumor marker such as TPA of the serum or of the content of the cyst is useful in observation of the clinical course.

Biomarkers, Tumor↗
PubMed1992

Electrotransformation of Thiobacillus ferrooxidans with plasmids containing a mer determinant.

The mer operon from a strain of Thiobacillus ferrooxidans (C. Inoue, K. Sugawara, and T. Kusano, Mol. Microbiol. 5:2707-2718, 1991) consists of the regulatory gene merR and an operator-promoter region followed by merC and merA structural genes and differs from other known gram-negative mer operons. We have constructed four potential shuttle plasmids composed of a T. ferrooxidans-borne cryptic plasmid, a pUC18 plasmid, and the above-mentioned mer determinant as a selectable marker. Mercury ion-sensitive T. ferrooxidans strains were electroporated with constructed plasmids, and one strain, Y4-3 (of 30 independent strains tested), was found to have a transformation efficiency of 120 to 200 mercury-resistant colonies per microgram of plasmid DNA. This recipient strain was confirmed to be T. ferrooxidans by physiological, morphological, and chemotaxonomical data. The transformants carried a plasmid with no physical rearrangements through 25 passages under no selective pressure. Cell extracts showed mercury ion-dependent NADPH oxidation activity.

Blotting, Southern↗
PubMed1992

[Selection of treatment in primary hepatolithiasis (PHL)].

Two hundred and three patients with PHL were encountered for the last 10 years. In order to select treatment of PHL, we classified PHL on the basis of atrophy of hepatic parenchyma (AHP), existence of extrahepatic gallstone and dilatation of extrahepatic bile duct (DEBD). For the case with AHP hepatic resection must be performed, because there is often chronic proliferating cholangitis and improvement in hepatic function can not be expected in view of AHP. For the case with extrahepatic gallstone without AHP hepatic resection. For the case with DEBD and without AHP extrahepatic gallstone must be removed. For the patient with extrahepatic gallstone and DEBD without AHP, indication of the removal of stones, depends on the existence of symptoms. Twenty-two cases treated by biliary drainage procedure often had some complications in postoperative course, that is 5 patients had cholangitis and 7 patients liver abscess. It was suggested, therefore, that biliary drainage procedure was contraindicated in PHL.

Aged↗
PubMed1991

Structural and functional analysis of a polyoma-related mammalian plasmid (L factor): the enhancer activity and plasmid establishment.

L factor is a unique plasmid DNA which was originally discovered in a subclone (B822) of mouse L cells at a high copy number (more than 5,000 copies/cell). The presence of L factor caused no detectable abnormalities to the plasmid-bearing cells. We determined the total DNA sequence of the L factor I (and a part of L factor II) and compared it with that of polyoma DNA. Both DNA are common to the general construction of DNA frames such as early, late and noncoding regions, suggesting the two to be closely related. On the other hand, the L factor DNA sequences differ substantially from that of polyoma in the DNA sequences corresponding to the polyoma large T antigen, capsid proteins and a portion of the enhancer region. In order to investigate the mechanism of plasmid establishment of L factor, we compared the enhancer activity, capacity of DNA replication and efficiency of plasmid establishment of L factor with those of polyoma. The results indicate that L factor enhancer activity and DNA replication capacity were considerably lower than those of polyoma, suggesting that these altered (lowered) activities associated with L factor contribute to the plasmidal establishment and stable maintenance of L factor.

Animals↗
PubMed1991

Common bile duct exploration--primary closure of the duct with retrograde transhepatic biliary drainage.

A new method of retrograde transhepatic biliary drainage (RTBD) using an RTBD tube with primary closure of the common duct was investigated with special reference to the usefulness and feasibility of this procedure. At operation, an atraumatic vinyl chloride tube was inserted from a choledochotomy incision and in most cases advanced via the left hepatic duct to the liver surface, which was then penetrated. After the choledochotomy incision had been primarily sutured, the RTBD tube was fixed to the abdominal wall. This drainage method was applied to 71 patients as an alternative to the conventional T-tube drainage and its effect on bile drainage was prominent. The insertion of an RTBD tube did not influence liver function tests and an RTBD tube cholangiography revealed no severe deformity at the primary closure site of the bile duct. The most common complication was movement of the optimal site for stenting of the bile duct, however, no serious complications were encountered. On average, the RTBD tube was removed on the 16th postoperative day, the mean postoperative stay in hospital being 22 days. These findings suggest the need for a prospective randomized clinical trial to prove the usefulness and feasibility of primary bile duct closure using our drainage method.

Bile↗
PubMed1991

Molecular analysis of rice dwarf phytoreovirus segment S11 corresponding to wound tumour phytoreovirus segment S12.

The complete nucleotide sequence of rice dwarf phytoreovirus (RDV) genome segment S11 was determined. S11 is 1067 nucleotides long. There is an inverted repeat of 10 bp adjacent to the conserved 5'-terminal hexanucleotide (5' GGUAAA 3') and 3'-terminal tetranucleotide (5' UAGU 3') sequences. A single large open reading frame found in the plus strand of S11 begins with the first AUG codon (bases 6 to 8) and extends for 567 bases. Evolutionary relatedness between RDV S11 and wound tumour phytoreovirus S12 based on amino acid sequence similarity (25.8%) was found. In addition to the first AUG triplet, RDV S11 possesses a second in-phase AUG triplet (positions 30 to 32) nearby, which conforms to the Kozak consensus sequence. Two forms of the protein were identified by using an in vitro transcription and translation system in which a tailored full-length cDNA was the initial template. The abolition of the first AUG codon by site-directed mutagenesis resulted in disappearance of the larger translation product. These results strongly suggest that the two products are translated from the first and second AUG codons. Whether the two proteins are expressed in vivo is at present unclear.

Amino Acid Sequence↗
PubMed1991

The merR regulatory gene in Thiobacillus ferrooxidans is spaced apart from the mer structural genes.

Two distinct merR genes, which regulate expression of the mercuric ion resistance gene (mer), of Thiobacillus ferrooxidans strain E-15 have been cloned, sequenced and termed merR1 and merR2. As a result of gene walking around two merR genes, it was found that these two genes were quite close in distance. The nucleotide sequence of the region (5,001 base pairs; PstI-EcoRI fragment) containing the merR genes was determined. Between the two merR genes, there were five potential open reading frames (ORFs). Two of these were identified as merC genes, and the other three as ORFs 1 to 3. ORFs 1 to 3 show significant homology to merA, tnsA from transposon Tn7, and merA, respectively. Both merR genes consist of a 408 bp ORF coding for 135 amino acids. Their gene products, MerR1 and MerR2, differed at three amino acid positions, and shared 56-57% and 32-38% identity with the MerRs from other Gram-negative and Gram-positive bacteria, respectively. Competitive primer extension analysis revealed that both regulatory genes were expressed in the host cells. These merR genes were located more than 6 kb from either end of the mer structural genes (merC-merA). This is the first example of merR being separated from the mer structural genes. The two merC genes, each of which coded for a 140-amino-acid protein, appeared to be functionally active because Escherichia coli cells carrying these merC genes on plasmid vectors showed hypersensitivity to HgCl2. However, ORFs 1 and 3, which were homologous to merA, seemed to be inactive both structurally and enzymatically. The gene arrangement in this region took on a mirror image, with the truncated tnsA as the symmetrical centre. It is suggested that the Tn7-like factor may have participated in gene duplication events of the mer region, and in its chromosomal integration.

Amino Acid Sequence↗
PubMed1991

Evidence for two sets of structural genes coding for ribulose bisphosphate carboxylase in Thiobacillus ferrooxidans.

Previously, we reported the cloning of the ribulose-1,5-bisphosphate carboxylase genes (rbcL1-rbcS1) of Thiobacillus ferrooxidans Fe1 (T. Kusano, K. Sugawara, C. Inoue, and N. Suzuki, Curr. Microbiol. 22:35-41, 1991). With these genes as probes, a second set of ribulose-1,5-bisphosphate carboxylase genes (rbcL2-rbcS2) was identified in the same strain and cloned. rbcL1 and rbcL2 encode the large subunits, and rbcS1 and rbcS2 encode the small subunits. Similar restriction patterns between these gene sets suggested a high level of sequence homology. In fact, sequence analysis showed that a 2.2-kb region, including the entire large and small subunit structural genes, was totally conserved in rbcL1-rbcS1 and rbcL2-rbcS2. The rbcL1 (rbcL2) and rbcS1 (rbcS2) genes were 1,422 and 333 bp in length and encoded 473- and 110-amino-acid proteins, respectively. The genes were separated by a 90-bp spacer sequence and were preceded by possible ribosome-binding sites. The N-terminal amino acid sequences of the subunit proteins, synthesized in Escherichia coli, were determined by Edman degradation and found to agree with the deduced amino acid sequences, except for the N-terminal methionine residue. The transcriptional start site of the rbc genes was determined by primer extension, and the size of the rbc transcript was estimated to be about 2.1 kb, suggestive of the cotranscription of rbcL1-rbcS1 and/or rbcL2-rbcS2 mRNAs. Comparisons of amino acid sequences of both subunits with those of other organisms revealed that the ribulose-1,5-bisphosphate carboxylase of T. ferrooxidans, a chemoautotrophic bacterium, is phylogenetically closer to the photosynthetic bacterium Chromatium vinosum than to another chemoautotrophic bacterium, Alcaligenes eutrophus.

Amino Acid Sequence↗
PubMed1990

Thiobacillus ferrooxidans mer operon: sequence analysis of the promoter and adjacent genes.

The merA upstream nucleotide (nt) sequence (1378 bp) of the Hg2(+)-resistance-encoding gene system (mer) in Thiobacillus ferrooxidans, was determined. The region contains two open reading frames: unidentified reading frame 1 (URF1) and merC. URF1 has 63-73% homology with those of Tn501, R100 and pDU1358, although the corresponding product has not yet been identified. Thiobacillus merC had 61% and 55% homology with R100 merC at the nt and amino acid (aa) sequence levels, respectively, and its product, consisting of 143 aa, was highly hydrophobic. No sequence homologous to merR, merT. merP or merD of R100 were observed on either strand. Within the 70-100-bp sequence upstream from the merC start codon. there was a sequence highly homologous to the promoter of merT of other Gram- mer systems. From primer extension and Northern-blot analyses, it became clear that merC and merA were co-transcribed from this putative transcription start point. The mer transcript in T. ferrooxidans was only detected in Hg2(+)-induced cells. Therefore, it was concluded that the T. ferrooxidans mer system is an inducible operon.

Amino Acid Sequence↗
PubMed1990

Clear and colorless fluid observed during percutaneous transhepatic gallbladder drainage.

Twelve patients with discharge of clear colorless fluid during percutaneous transhepatic gallbladder drainage (PTGBD) were encountered during a period of 4.5 years. On the average, the fluid appeared on the 12th day after PTGBD and continued to flow until the completion of observation. The volume was usually less than 60ml per day. It flowed in an alternating pattern with normal yellow color bile each day. The fluid was observed in patients in whom satisfactory patency of the biliary system was confirmed by cholangiography and/or cholangio-fiberscopy. Biochemical examinations of the fluid revealed lower biliary lipids but a similar electrolyte composition compared to bile of normal color. It was alkaline. These observations indicate that the clear colorless fluid is different from what is known as "white bile", which is produced when there is an obstruction of the biliary tree. The fluid may be secreted from the gallbladder epithelium or the bile duct epithelium. The significance was not clarified in this study. Further investigation is necessary to elucidate the clinical implications of the clear and colorless fluid secretion.

Bile↗
PubMed1990

Sequence analysis of rice dwarf phytoreovirus genome segments S4, S5, and S6: comparison with the equivalent wound tumor virus segments.

The complete nucleotide sequences of genome segments S4, S5, and S6 of rice dwarf phytoreovirus (RDV) were determined. S4 and S5 consist of 2468 and 2570 base pairs, respectively, S5 thus being larger in size than S4, contrary to the situation suggested by their relative migration in a polyacrylamide gel. S6 is 1699 nucleotides long. The individual segments have segment-specific inverted repeats adjacent to the conserved terminal sequences (5'GGUAAA---UGAU3' for S4, 5'GGCAAA---UGAU3' for S5 and S6). S4, S5, and S6 each have single long open reading frames encoding 727, 801, and 509 amino acids, respectively. A low level of amino acid sequence homology was observed between RDV S4 and wound tumor virus (WTV) S4 (22.4%), and between RDV S6 and WTV S6 (20.2%). On the other hand, RDV S5 and WTV S5 show 52.0% amino acid sequence similarity, indicating that S5 is much more conserved than any other segments of RDV and WTV reported so far. Further comparative analyses indicate that the RDV segment shows a greater frequency of usage of codons XYG and XYC, and much less frequent usage of codon XYA than the equivalent WTV segment, this codon preference bias being more conspicuous than expected from the base contents.

Amino Acid Sequence↗
PubMed1990

Sequence analysis of the rice dwarf phytoreovirus segment S3 transcript encoding for the major structural core protein of 114 kDa.

The primary structure of rice dwarf phytoreovirus (RDV) genome segment S3 was determined. RDV S3 consists of 3195 nucleotides. A 14-bp segment-specific inverted repeat is located immediately adjacent to the conserved terminal sequence (5'GGCAAA---UGAU3'). A single long open reading frame encoding for 1019 amino acids with an Mr of 114,289 is also identified. In order to investigate the localization of the predicted polypeptide, we determined the amino acid sequence of the 26-kDa peptide fragment obtained from the structural core protein digested by Staphylococcus aureus V8 protease. The sequence of the fragment was found in the translational product presumed from the nucleotide sequence of RDV S3, indicating that RDV S3 encodes the major structural core protein of 114 kDa.

Amino Acid Sequence↗