Biomedical subjects

Kazuo Tsujimoto

Publications and source records attributed to Kazuo Tsujimoto.

5 recordsLinked to original sources

PubMed2004

Methyl p-coumarate, a melanin formation inhibitor in B16 mouse melanoma cells.

p-Coumaric acid (4-hydroxycinnamic acid) and methyl p-coumarate (methyl 4-hydroxycinnamate) inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase. However, both were oxidized as monophenol substrate analogues at an extremely slow rate. This oxidation was significantly accelerated as soon as catalytic amounts (0.01 mM) of L-3,4-dihydroxyphenylalanine (L-DOPA) became available as a co-factor. Methyl p-coumarate significantly suppressed the melanin formation in B16 mouse melanoma cells, whereas p-coumaric acid did not show this activity.

Animals↗

PubMed2004

Prosthetic alignment and sizing in computer-assisted total knee arthroplasty.

We implanted 60 posterior stabilized total knee prostheses (P.F.C. Sigma, DePuy, Warsaw, USA). In 30 cases, we used a CT-free navigation system (Vector Vision, Brain LAB, Heimstetten, Germany), and in 30 matched-paired controls, we used a conventional manual implantation. We compared postoperative long-leg radiographs in the two groups. The results revealed a significant difference in favor of navigation. In addition, we compared the preoperative anteroposterior dimension of the femoral condyle with the postoperative value. While there were no significant differences in the preoperative anteroposterior dimension of the femoral condyle between the two groups, the postoperative value in the navigation group was significantly larger than that of the preoperative value. Therefore, surgeons using navigation systems should guard against the possibility of oversizing when determining the size of the femoral component.

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PubMed2004

Synergistic effects of anacardic acids and methicillin against methicillin resistant Staphylococcus aureus.

The synergistic effects of 6-alk(en)ylsalcylic acids, also known as anacardic acids, in combination with methicillin against Staphylococcus aureus ATCC 33591 (MRSA) was investigated. The double bond in C15-anacardic acids is not essential in eliciting the antibacterial activity but is associated with increasing the activity. The synergistic effects decreased with increasing the number of double bonds in the alkyl chain. On the other hand, the antibacterial activity of anacardic acids possessing different alkyl chain lengths against the same MRSA strain was found to be a parabolic function of their lipophilicity and maximized with the alkyl chain length of C10 and C12. Notably, the synergistic effects were noted to increase with increasing the alkyl chain length.

Anacardic Acids↗

PubMed2003

Antibacterial action of anacardic acids against methicillin resistant Staphylococcus aureus (MRSA).

The structural and antibacterial activity relationship of 6-alk(en)ylsalicylic acids, also known as anacardic acids, was investigated against Gram-positive bacteria, emphasizing the methicillin resistant Staphylococcus aureus ATCC 33591 (MRSA) strain. The unsaturation in the alkyl side chain is not essential in eliciting activity but is associated with increasing the activity. The antibacterial activity of methicillin against MRSA strains was significantly enhanced in combination with C(12:0)-anacardic acid, and the fractional inhibitory concentration index for this combination was calculated as 0.281. It appears that biophysical disruption of the membrane (surfactant property) is due to the primary response to their antibacterial activity, while biochemical mechanisms are little involved. The compounds possessing the similar log P values exhibit similar activity.

Anacardic Acids↗

PubMedDate not supplied

Enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty in the presence of kyphosis.

BACKGROUND CONTEXT: In cranio-vertebral junction, retro-odontoid pseudotumor without evidence of rheumatoid arthritis is a rare condition. PURPOSE: To discuss the mechanism of enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty as a predictable complication. STUDY DESIGN: We report a rare case of an elderly man with non-inflammatory retro-odontoid pseudotumor after cervical expanding laminoplasty. PATIENT SAMPLE: A 76-year-old man presented with progressive quadriparesis of two week's duration caused by enlarging retro-odontoid soft tissue mass after cervical laminoplasty. OUTCOME MEASURES: Pre- and postoperative image, including X-ray and MRI, and the Japanese Orthopaedic Association scores for cervical myelopathy were assessed. METHODS: The patient subsequently underwent resection of the posterior arch of the atlas and posterior fusion from the occiput to C6 using Olerud system without removal of the retro-odontoid soft tissue mass. RESULTS: One year after surgery, the Japanese Orthopaedic Association scores for cervical myelopathy improved from 1 to 10 points, and postoperative MRI showed a mild reduction in the size of the retro-odontoid soft tissue mass. CONCLUSIONS: The kyphotic stability from C3 to C7 after laminoplasty, leading to a compensatory hyperlordosis at the occipitocervical junction, may cause the development of a degenerative osteoarthritic change, resulting in the production of an enlarging mass. Not only posterior compression of spinal cord due to posterior arch of the hyperextended atlas but also anterior compression of spinal cord due to retro-odontoid pseudotumor probably triggered the severe myelopathy. Laminoplasty may be inappropriate in cervical myelopathy with kyphosis.

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