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Biomedical subjects

C Imamura

Publications and source records attributed to C Imamura.

7 recordsLinked to original sources
PubMed2001

Correlation between Shine--Dalgarno sequence conservation and codon usage of bacterial genes.

In this study, we analyzed the correlation between codon usage bias and Shine--Dalgarno (SD) sequence conservation, using complete genome sequences of nine prokaryotes. For codon usage bias, we adopted the codon adaptation index (CAI), which is based on the codon usage preference of genes encoding ribosomal proteins, elongation factors, heat shock proteins, outer membrane proteins, and RNA polymerase subunit proteins. To compute SD sequence conservation, we used SD motif sequences predicted by Tompa and systematically aligned them with 5'UTR sequences. We found that there exists a clear correlation between the CAI values and SD sequence conservation in the genomes of Escherichia coli, Bacillus subtilis, Haemophilus influenzae, Archaeoglobus fulgidus, Methanobacterium thermoautotrophicum, and Methanococcus jannaschii, and no relationship is found in M. genitalium, M. pneumoniae, and Synechocystis. That is, genes with higher CAI values tend to have more conserved SD sequences than do genes with lower CAI values in these organisms. Some organisms, such as M. thermoautotrophicum, do not clearly show the correlation. The biological significance of these results is discussed in the context of the translation initiation process and translation efficiency.

Base Sequence↗
PubMed1996

[Specific inhibitory effect of hybrid liposomes on the growth of hybridoma cells in vitro].

Remarkably high inhibitory effects of the hybrid liposomes composed of L-alpha-dimyristoyl-phosphatidylcholine (DMPC) and polyoxyethylenealkyl ether (C14(EO)n, n = 6-8 and C12(EO)n, n = 8-12)) on the growth of human lymphoma-human B-lymphocyte hybridoma (HF) cells in vitro were obtained. The hybrid liposomes composed of 90 mol% DMPC/10 mol% C14(EO)n (n = 6-8) or C12(EO)n (n = 8-12) were more fluid as compared with 90 mol% DMPC/10 mol% C14(EO)4 or C12(EO)n (n = 4, 23) hybrid liposomes on the basis of fluorescence polarization measurements. These results suggest that the inhibitory effects of the hybrid liposomes on the growth of HF cells should be related to the membrane fluidity. No toxicity to normal rats in vivo was observed in the experiment using 90 mol% DMPC/10 mol% C14(EO)7 or 90 mol% DMPC/10 mol% C12(EO)12 hybrid liposomes.

Animals↗
PubMed1995

Specific hybrid liposomes composed of phosphatidylcholine and polyoxyethylenealkyl ether with markedly enhanced inhibitory effects on the growth of tumor cells in vitro.

The hybrid liposomes (90mol% DMPC/10mol% C12(EO)8 and 90mol% DMPC/10mol% C12(EO)12) have a highly inhibitory action against the growth of tumor cells. The uniform and stable structure of the hybrid liposomes was revealed on the basis of electron microscopy and dynamic light scattering measurements.

Antineoplastic Agents↗
PubMed1994

Blood pressure measurement by eye care practitioners.

We surveyed a random sample of 250 optometrists (OD) and 250 ophthalmologists (MD) in November 1991 to determine if they were involved in blood pressure measurement. A 50.4 percent and 34.8 percent response rate was obtained from ODs and MDs, respectively. Of those responding, 85 percent of the optometrists and 87 percent of the ophthalmologists reported that they did routinely question their patients about blood pressure, while 65.9 percent of the optometrists and 94.2 percent of the ophthalmologists reported owning blood pressure measurement equipment. Of those owning blood-pressure measuring equipment, approximately 20 percent of both professions reported measuring blood pressure on patients with a defined set of historical or observed risk factors. More optometrists should own blood pressure measurement equipment and measure blood pressure on a routine basis. The detection, referral, and co-management of hypertension by optometrists is important in providing primary health care.

Blood Pressure↗