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Biomedical subjects

M Takanami

Publications and source records attributed to M Takanami.

At least 55 records · Page 3Linked to original sources
PubMed1985

Cloning of the contiguous 165-kilobase-pair region around the terminus of Escherichia coli K-12 DNA replication.

Escherichia coli K-12 chromosomal DNA was partially digested with either EcoRI or HindIII, and cosmid libraries were constructed. By screening these libraries, a series of partially overlapping clones which covered the terC region was isolated. The cloned area spanned about 165 kilobase pairs, corresponding to the 29.7-to-33.2-min region of the genetic map of the E. coli chromosome.

Chromosome Mapping↗
PubMed1984

Sequence organization of replication origin of the Escherichia coli K-12 chromosome.

A sequence of 245 base-pairs (oriC) in the replication origin of the Escherichia coli K-12 chromosome has been shown to provide all the information essential for initiation of bidirectional replication. In order to elucidate the sequence organization of oriC, numerous mutants carrying a single-to-multiple transitions from G X C to A X T base-pair were constructed by localized mutagenesis in vitro, which uses sodium bisulfite, and the correlation between the mutation sites and replicating ability (Ori function) was systematically analyzed. By isolating non-defective (Ori+) mutants with multiple base changes, transitions at 71 positions among 101 G X C pairs in oriC were found to have no effect on Ori function. Investigation of defective (Ori-) mutants, on the other hand, showed that individual replacements at 18 positions were detrimental to Ori function to some extent. These irreplaceable G X C pairs fell in the positions where no substitution was detected in the Ori+ mutants. The defect of the Ori- mutants with a single base substitution was generally weaker than that of the previously constructed Ori- mutants lacking a part of oriC. The addition of two or more base changes each giving a faint Ori- phenotype, however, resulted in a more intensive Ori- phenotype. We have previously demonstrated that oriC contains several regions where deletion or insertion of oligonucleotides leads to strong Ori- phenotypes. Transitions in those areas did not cause any defect of Ori function. Combining present results on base substitution mutants with the previous observations together, we assumed that the oriC sequence provides multiple interaction sites with replication initiation factors, and the precise arrangement of these sites are required for Ori function.

Base Composition↗
PubMed1984

[Clinical experience of bromazepam for psychogenic impotence patients].

A clinical trial was performed with the tranquilizer Bromazepam on 39 patients undergoing diagnosis of psychogenic impotence, and the drug effect was evaluated according to the criteria based on our protocol. The protocol specifies 8 tests (1 for libido, 4 for erection, 2 for ejaculation, 1 for orgasm) which are scored according to an arbitrary logarithmic scoring system. At the end of the study the points made in the 8 tests were added to obtain the total score as the basis for evaluation of the overall drug effect. After treatment all tests showed an improvement, and the improvement in erection during masturbation, reflective erection, and condition of ejaculation was statistically significant. The total score also improved from 16.77 +/- 2.62 (mean +/- S.D.) before treatment to 11.42 +/- 1.96 after treatment, and the change was again statistically significant (P less than 0.05). The rate of satisfaction as a subjective symptom of improvement also increased from 25.38 +/- 4.40% to 39.10 +/- 4.53%. The results of the present study provide evidence to indicate that Bromazepam is beneficial for psychogenic impotence.

Administration, Oral↗
PubMed1984

[Clinical experience of Hachimijiogan for male infertility patients].

We treated 53 patients for male infertility with TSUMURA - Hachimijiogan given as a daily dose of 7.5 g for 144 days on the average. The sperm density was improved by administration to 10 X 10(6)/ml or more in 22 patients (41.5%) and lowered to 10 X 10(6)/ml or more in only 2 patients (3.8%). The sperm motility was improved by 10% or over in 29 patients (54.7%) as compared with 5 patients (9.4%) in whom it was lowered by 10% or more. The sperm motile efficiency index ( SMEI ) was improved in 40 (75.5%) of the 53 patients. Statistically significant differences were noted in the improvement in sperm density, sperm motility and SMEI . By contrast, there was no difference in semen volume, sperm morphology or sperm agglutination between the pre- and post- treatment periods. During the period of treatment, the wives of 4 patients (7.5%) conceived children. These results suggest that TSUMURA - Hachimijiogan is effective for male infertility to a certain extent and that clinical trials on its use for male infertility may be meaningful.

Adult↗
PubMed1983

Essential structure of E. coli promoter: effect of spacer length between the two consensus sequences on promoter function.

A promoter with the consensus sequence(TTGACA and TATAAT) at -35 and -10 regions was constructed, and the distance between the two consensus sequences was independently altered at two restriction sites. In an in vitro transcription system, a maximum activity was observed at the spacer length of 17 base-pairs regardless of the sites of space adjustment. Evidence was also provided that the start point of transcription was fixed by the consensus sequence at the -10 region.

Base Composition↗
PubMed1983

The 245 base-pair oriC sequence of the E. coli chromosome directs bidirectional replication at an adjacent region.

The replication origin of the E. coli K-12 chromosome has been isolated as autonomously replicating molecules(oriC plasmid), and the DNA region essential for replicating function(oriC) has been localized to a sequence of 232-245 base-pairs(bp) by deletion analysis. In this report, the functional role of oriC was analysed by using an in vitro replication system and various OriC+ and OriC- plasmids previously constructed. The results obtained were summarized as follows: (1) The oriC sequence contained information enough to direct bidirectional replication. (2) The actual DNA replication began at a region near, but outside, oriC and progressed bidirectionally. (3) Initiation of DNA synthesis at the specific region required the dnaA-complementing fraction from cells harboring a dnaA-carrying plasmid.

Base Sequence↗
PubMed1982

New restriction endonucleases from Acetobacter aceti and Bacillus aneurinolyticus.

Two restriction endonucleases with new sequence specificities have been isolated from Acetobacter aceti IFO 3281 and Bacillus aneurinolyticus IAM 1077 and named AatII and BanII, respectively. Based on analysis of the sequences around the restriction sites, the recognition sequences and cleavage sites of these endonucleases were deduced as below: (formula; see text)

Acetobacter↗
PubMed1982

Structure of replication origin of the Escherichia coli K-12 chromosome: the presence of spacer sequences in the ori region carrying information for autonomous replication.

The replication origin region of the Escherichia coli K-12 chromosome has been cloned, and a region of 245 base-pairs has been shown to contain all the information for autonomous replication (defined ori). In order to obtain further information on the sequence organization in the defined ori stretch, various types of mutation were introduced by in vitro techniques at a restriction site (AvaII site) which locates near the middle of ori. When the correlation between these mutations and replicating function was examined, different effects were obtained with the types of mutation: the replicating function was completely destroyed by either insertion or deletion of short sequences, but not by base-substitutions. Based on these observations and on the fact that multi-gene products are involved in the initiation of replication, we assume that two categories of sequences are present within the ori stretch, one specifying interaction with initiation factors (recognition sequences) and the other spacing the recognition sequences in appropriate distances (spacer sequences), and that the AvaII site is located in the spacer region.

Base Composition↗
PubMed1981

Nucleotide sequence of the transforming early region E1b of adenovirus type 12 DNA: structure and gene organization, and comparison with those of adenovirus type 5 DNA.

The nucleotide sequence of the entire transforming early region of E1b of the highly oncogenic adenovirus type 12 (Ad12) DNA has been determined. The total sequence (3860 base pairs) encompasses the entire transforming early region E1 of Ad12 DNA. From the sequence for the E1b region of Ad12, and the transcription map of the E1b region (1, 2, 3, and this paper) the structure and gene organization of the early region E1b of Ad12 DNA were analyzed and compared with those of the E1b region in the non-oncogenic Ad5 DNA (4, 5). Most of the sequences in the E1b region of Ad12 was highly homologous to that of Ad5. It is predicted that the Ad12 region E1b codes for polypeptides of 53.9, 19.1, and 8.9 kd. This situation is identical with that of the Ad5 region E1b which codes for polypeptides of 54.9, 20.6, and 8.3 kd. The function of these predicted polypeptides encoded by the E1b regions in cell transformation is discussed.

Adenoviridae↗
PubMed1981

A computer method for construction of secondary structure from polynucleotide sequence. Possible structure of the bacterial replication origin.

A computer method to search the possible secondary structure of a long polynucleotide was developed. As a criterion for the stabilization of a secondary structure, free energy originating from base-pairing was employed, since the structure in solution would be at the free energy minimum. The method is summarized as follows: all possible helices are collected from a given nucleotide sequence under restrictions that the length of a helix is greater than N0 bases (e.g., four bases) and the free energy of the helix calculated according to free energies of two successive sequence-dependent basepairs is lower than E0 (e.g., -5 kcal/mol). The search of secondary structures of low free energy is performed by connecting one helix to another without allowing any base-pairing between loops. For connecting single-stranded regions, destabilizing free energy of 2--3 kcal/mol is added. The method was first applied to several tRNAs and the clover-leaf structure of tRNA was obtained as a free energy minimum. Then, possible secondary structures of the replication origin regions of the Escherichia coli and Salmonella typhimurium chromosomes were examined by the method, assuming that one of the strands in the origin region takes a specific secondary structure. The lowest-energy structure for the E. coli origin was found to be approximately identical to that for the S. typhimurium origin region.

Base Sequence↗
PubMed1981

Nucleotide sequence of the asnA gene coding for asparagine synthetase of E. coli K-12.

We have subcloned the asnA gene of E. coli K-12, a gene coding for asparagine synthetase, from a previously cloned 6 mega-dalton segment of E. coli chromosome containing the DNA replication origin, ori, and asnA. The complete nucleotide sequence of the asnA gene was determined: the region of the structural gene extends 990 base-pairs at nucleotide positions 1434-2423 (see Fig. 3), which codes for a polypeptide of 330 amino-acid residues with a molecular weight of 36,688 daltons. The nucleotide sequences of the promoter and the ribosome-binding site of the gene are also assigned. We discuss the properties of its polypeptide.

Amino Acid Sequence↗
PubMed1981

Nine unique repeating sequences in a region essential for replication and incompatibility of the mini-F plasmid.

The nucleotide sequence of a 2248 bp portion of the plasmid mini-F has been determined. This region includes the replication origin and all of the plasmid-coded information required for replication. The same region is also capable of expressing incompatibility. A striking feature of the sequence is the presence of nine 19-bp repeating units. Four of these repeats, all arranged in one direction, comprise a cluster, and the remaining five, all arranged in the opposite direction, comprise another cluster. These clusters are separated by a region of about 850 bp that encodes a hypothetical 29-kd polypeptide. This region has sequences highly homologous to those found in the origin regions of the Escherichia coli (Sugimoto et al., 1979; Meijer et al., 1979) and Salmonella typhimurium (Zyskind and Smith, 1980) genomes.

Cloning, Molecular↗