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Biomedical subjects

J Yamane

Publications and source records attributed to J Yamane.

7 recordsLinked to original sources
PubMed2005

Establishment of graded spinal cord injury model in a nonhuman primate: the common marmoset.

Most previous studies on spinal cord injury (SCI) have used rodent models. Direct extrapolation of the results obtained in rodents to clinical cases is difficult, however, because of neurofunctional and anatomic differences between rodents and primates. In the present study, the development of histopathologic changes and functional deficits were assessed quantitatively after mild, moderate, and severe spinal cord contusive injuries in common marmosets. Contusive SCI was induced by dropping one of three different weights (15, 17, or 20 g) at the C5 level from a height of 50 mm. Serial magnetic resonance images showed significant differences in the intramedullary T1 low signal and T2 high signal areas among the three groups. Quantitative histologic analyses revealed that the number of motor neurons, the myelinated areas, and the amounts of corticospinal tract fibers decreased significantly as the injury increased in severity. Motor functions were evaluated using the following tests: original behavioral scoring scale, measurements of spontaneous motor activity, bar grip test, and cage-climbing test. Significant differences in all test results were observed among the three groups. Spontaneous motor activities at 10 weeks after injury were closely correlated with the residual myelinated area at the lesion epicenter. The establishment of a reliable nonhuman primate model for SCI with objective functional evaluation methods should become an essential tool for future SCI treatment studies. Quantitative behavioral and histopathologic analyses enabled three distinct grades of injury severity (15-g, 17-g, and 20-g groups) to be characterized with heavier weights producing more serious injuries, and relatively constant behavioral and histopathologic outcomes.

Animals↗
PubMed1995

DNA recognition by peptide oligomers.

It has been demonstrated that coupling a host-guest complex formation onto the DNA binding ability of short peptides gave raise a cooperative DNA binding by short peptide dimers. This strategy was extend to study the DNA binding by oligomers of short peptide. An amino acid bearing the adamantyl group was incorporated at the N-terminal of a peptide derived from the basic region of a yeast transcription activator GCN4, and beta-cyclodextrin was attached at the C-terminal cysteine residue in the same peptide chain. DNA binding of the peptide with both host and guest molecules to tandemly repeated DNA sequences was studied by gel shift assay.

Amino Acid Sequence↗
PubMed1993

Effect of organic germanium compound (Ge-132) on experimental osteoporosis in rats.

1. The therapeutic effect of organic germanium compound, 2-carboxyethylgermaniumsesquioxide (Ge-132), for experimental osteoporosis was studied using ovariectomized rats maintained on a low calcium containing diet. 2. Serum calcitonin (sCT) level was decreased and serum parathyroid hormone (sPTH) level was increased by ovariectomy and the decrement and increment rates, respectively, were reduced by administration of Ge-132. Thus, the sCT/sPTH ratio was greater in the groups given Ge-132, indicating that the resorption was somehow inhibited by Ge-132. 3. The transverse strength of femur bone was significantly enhanced by Ge-132. 4. A trend was found in the group given Ge-132 for a larger femur cortical bone index. 5. The relative femur bone wet weight was greater in the group given Ge-132. 6. These results indicate that Ge-132 prevents decreased bone strength, and affects the femur cortical bone index, and bone mineral mass caused by osteoporosis.

Animals↗
PubMed1991

Ampicillin concentrations in human oral tissues following a single oral administration of lenampicillin.

1. Ampicillin concentrations in serum (n = 20), gingiva (n = 12), jawbone (n = 13), dental follicle (n = 12), radicular granuloma (n = 2) and radicular cyst (n = 2) were measured in specimens obtained during 0.5-2.5 hr after a single oral administration of lenampicillin (equivalent to 500 mg of ampicillin). 2. Measurable ampicillin concentrations were found in all serum and tissues. 3. Ampicillin concentrations in serum and tissues except for some gingiva and jawbone exceeded MIC for 90% of clinically isolated strains of alpha-hemolytic Streptococci. 4. Ampicillin concentrations in gingiva and jawbone were below the MIC for 90% in 2 out of 12 and 4 out of 13 specimens, respectively.

Adult↗
PubMed1989

[Pharmacokinetics of lidocaine and its metabolites in dog. Comparison between normal and CCl4-induced hepatic lesion].

Pharmacokinetic analysis of lidocaine (Lid) and its metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), was performed in a dog bearing carbon tetrachloride (CCl4, 0.75 ml/kg ip)-induced acute hepatitis. Following pentobarbital sodium (25 mg/kg iv) anesthesia, lidocaine hydrochloride (2.5 mg/kg iv) was given and arterial blood was drawn 2, 5, 10, 15, 30, 45, 60, 90, and 120 min after administration. Lid and its metabolites in plasma were extracted with chloroform-hexane-isopropanol (60 : 30 : 10), and organic layer was dried down at 50 degrees C under N2. The residue was dissolved in 50mM phosphoric acid and subjected to HPLC analysis. 4-compartment model was introduced to analyze pharmacokinetic parameters, and which gave the most reasonable fit with actual results. Control experiment was carried out using identical dog with acute hepatitis. The following results were given: 1) Elimination of Lid was slightly depressed, but T1/2 was not altered. Plasma level of Lid was kept higher. 2) As for MEGX, the formation was depressed, and upto 23 min after Lid administration, MEGX concentration in the dog with acute hepatitis was lower than that of control, but after 23 min it was vice versa. 3) As for GX, the formation was depressed, but the elimination was not affected. In the dog with CCl4-induced hepatitis, metabolism of Lid was suppressed, and which resulted in maintaining a relatively higher levels of Lid and MEGX concentration in plasma. These results suggested that care should be taken to avoid acute poisoning with Lid especially in patients with acute hepatitis.

Animals↗