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Biomedical subjects

T Yamasaki

Publications and source records attributed to T Yamasaki.

At least 37 records · Page 2Linked to original sources
PubMed2001

Pax6 regulates granule cell polarization during parallel fiber formation in the developing cerebellum.

The molecular mechanisms that govern the coordinated programs of axonogenesis and cell body migration of the cerebellar granule cell are not well understood. In Pax6 mutant rats (rSey2/rSey2), granule cells in the external germinal layer (EGL) fail to form parallel fiber axons and to migrate tangentially along these fibers despite normal expression of differentiation markers. In culture, mutant cells sprout multiple neurites with enlarged growth cones, suggesting that the absence of Pax6 function perturbs cytoskeletal organization. Some of these alterations are cell-autonomous and rescuable by ectopic expression of Pax6 but not by co-culture with wild-type EGL cells. Cell-autonomous control of cytoskeletal dynamics by Pax6 is independent of the ROCK-mediated Rho small GTPase pathway. We propose that in addition to its roles during early patterning of the CNS, Pax6 is involved in a novel regulatory step of cytoskeletal organization during polarization and migration of CNS neurons.

Animals↗
PubMed2001

Superoxide- and 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activities of soyasaponin beta g related to gallic acid.

Soyasaponin beta p g at 1 mm had 8% scavenging activity for O2-, and 25 microM beta g scavenged 20.9% for the DPPH radical (IC50: 63.8 microM). In the soyasaponin beta g-gallic acid system, synerigistic effects were observed at a low level of gallic acid concentration. The spin density distribution calculated by the MNDO/AM1 method showed unpaired electron localization on the carbons at C-4 and C-6, and on the ketone group at C-4 of the DDMP moiety. Furthermore, for soyasaponin beta g, the MNDO/AM1 method gave an ionization potential of 8.38 eV, electron affinity of 1.16 eV and Mulliken electronegativity of 4.77 eV. Based on this evidence, the synergistic antiradical effects of the soyasaponin beta g-gallic acid system are assumed to involve two-electron reduction from gallic acid.

Bepridil↗
PubMed2001

Complete familial Currarino triad. Report of three cases in one family.

The Currarino triad is a unique complex of congenital caudal anomalies including anorectal malformation, sacral bone abnormality, and presacral mass. In this report, the authors describe three cases with the complete Currarino triad in a family. The authors treated a 30-year-old mother with an anterior sacral meningocele, her 1-year-old son with a combination of anterior sacral meningocele and dermoid cyst, and her 4-year-old daughter with an epidermoid cyst. These three patients had associated sacral agenesis and anorectal malformations. To the authors' knowledge, this is the first report describing radiological and operative findings of complete familial Currarino triad in which a mother and her two children were affected.

Abnormalities, Multiple↗
PubMed2001

[Multicystic sphenoethmoidal mucocele with intracranial extension presented with generalized convulsion: a case report].

A 53-year-old male presented with generalized convulsion. Magnetic resonance imaging and computed tomography revealed large sphenoethmoidal mucocele extending intracranially. Signal intensities between paranasal and intracranial portion of the mucocele were different. Preoperatively it was not obvious that intracranial portion of the mucocele communicated with paranasal portion of the mucocele. We approached the paranasal portion of the mucocele by transsphenoidal approach resulting in disappearance of the intracranial portion of the mucocele. Sphenoethmoidal mucocele with intracranial extension presenting with generalized convulsion was the first case in the literature. Transsphenoidal approach for sphenoethmoidal mucocele with intracranial extension is the first choice of surgical treatment, though neuroimaging shows that there is no communication between paranasal and intracranial portion of mucocele.

Brain Diseases↗
PubMed2001

[A comparison of propofol and midazolam in sedation of mechanically-ventilated postoperative patients].

To compare the quality of sedation using propofol (n = 8) vs midazolam (n = 7) we evaluated their effectiveness, safety, and recovery time after their continuous infusion in patients who required mechanical ventilation after cervical spine surgery. We also calculated the cost of drugs used during the mechanical ventilation. In addition, processed electroencephalogram (pEEG) was monitored employing spectral edge frequency 90 (SEF 90) as an indicator of sedation. Both drugs produced good sedation without any complication. The patients who had received propofol were extubated significantly earlier than those who had received midazolam (P; 35 +/- 18 mins, M; 97 +/- 55 mins). However, the mean drug cost in the propofol group was five times higher than that in the midazolam group (P; yen 15,881 +/- 7,788, M; yen 3,355 +/- 1,187). There was no correlation between the value of SEF 90 and the depth of sedation during mechanical ventilation. In conclusion, propofol exhibited the shorter recovery time after cessation of the continuous infusion than midazolam, but it costed five times compared with midazolam. SEF 90 failed to indicate the depth of sedation during mechanical ventilation.

Adult↗
PubMed2001

[A case of primary pleural leiomyosarcoma].

A 70-year-old man was admitted to our hospital with complaints of chest pain and exertional dyspnea. Chest radiography and computed tomography (CT) revealed right pleural effusion and pleural thickening on admission. The pleural fluid was bloody. Microbiological and cytologic examinations of the fluid were negative. The chest CT revealed progress of pleural thickening after hospitalization. A thoracoscopic pleural biopsy was performed, and the histological finding of the excised specimen was leiomyosarcoma. Because no organ of origin of the leiomyosarcoma, other than the pleura, was detected, this case was diagnosed as a primary pleural leiomyosarcoma. It is thought that leiomyosarcoma originating from the pleura is rare.

Aged↗
PubMed2001

[A case of ankylosing spondylitis associated with pulmonary aspergillosis and amyloidosis].

A 56-year-old man was admitted because of diarrhea, cough, weight loss, and disturbance of consciousness. He had been diagnosed as having ankylosing spondylitis at 18-years old. The spondylitis progressed until there was complete rigidity of the spine including the neck, hip and knee joints. Human leukocyte antigen (HLA) B27, which has been characteristic of ankylosing spondylitis, was also present in this case. A chest radiograph showed pleural thickness and a cavity in the right upper lobe; and a soft tissue mass and fluid level was found in the cavity. Aspergillus fumigatus was detected in the sputum and pulmonary aspergillosis was diagnosed. Biopsy of the colon revealed that a large interstitial amyloidosis. Despite the treatment of the patient's malnutrition and lung aspergillosis using amphotericin B, the clinical course was rapidly progressive and the patient died of respiratory failure due to lung aspergillosis. It is important to be aware of these rare complications, which are correlated with the prognosis in cases of ankylosing spondylitis.

Amyloidosis↗
PubMed2001

Cloning and expressing of the three repeat fragments of Plasmodium falciparum 11.1 gene.

OBJECTIVE: To clone and express the 3R, 6R and 9R repeat fragments of Plasmodium falciparum(Pf11.1) gene. METHODS: Three repeat fragments from the genomic DNA of Plasmodium falciparum 3D7 strain cultivated were amplified by using the designed primers. The PCR products were cloned into the pT7 vector for bi-direction sequencing. The sequencing results were analysised by GENETYX-MAC. And then the amplified fragments were subcloned into pET32a(+) or pET32b(+) in order to express the recombinant proteins under the induction of IPTG in E. coli BL21. RESULTS: 3R,6R and 9R fragments with sizez of 552 bp, 630 bp and 444 bp respectively were successfully amplified by PCR. The sequence analysis showed that there were 4 more 3AA units and one more 6AA unit in Pf11.1 gene of 3D7 strain as compared with Palo Alto strain. The homologies of the nucleotide sequence between the 3R fragment and the 6R fragment of the two strains were 92.8% and 95.1%, respectively. The amplified 9R fragment contains 139AA repeat units. The three recombinant proteins were expressed in BL21 strain with molecular weights of 45, 60 and 42 kDa. CONCLUSION: We got the 3R, 6R and 9R fragments separately by PCR and expressed them in E. coli successfully. The Pf11.1 gene of 3D7 strain is highly homologous to that of the Palo Alto strain.

Animals↗
PubMed2000

Regulation of phosphoenolpyruvate carboxykinase and insulin-like growth factor-binding protein-1 gene expression by insulin. The role of winged helix/forkhead proteins.

Winged helix/forkhead (Fox) transcription factors have been implicated in the regulation of a number of insulin-responsive genes. The insulin response elements (IREs) of the phosphoenolpyruvate carboxykinase (PEPCK) and insulin-like growth factor-binding protein-1 (IGFBP-1) genes bind members of the FKHR and HNF3 subclasses of Fox proteins. Previous mutational analyses of the PEPCK and IGFBP-1 IREs revealed mutations which do not affect the binding of HNF3 proteins to these elements but do eliminate the ability of the IREs to mediate an insulin response. This dissociation of binding and function provided compelling evidence that HNF3 proteins, per se, are not insulin response proteins. The same approach was used here to determine if FKHRL1, a member of the FKHR subclass of Fox proteins, binds to the PEPCK and IGFBP-1 IREs in a manner that correlates with the ability of these elements to mediate an insulin response. Overexpression of FKHRL1 stimulates transcription from transfected reporter constructs that contain a multimerized PEPCK IRE or an IGFBP-1 IRE and this stimulation is repressed by insulin. There is a direct correlation between the ability of mutant versions of the PEPCK and IGFBP-1 IREs to bind FKHRL1 and their ability to mediate FKHRL1-induced transcription when FKHRL1 is overexpressed. However, under conditions where FKHRL1 is not overexpressed, there is a lack of correlation between FKHRL1 binding to mutant versions of the PEPCK and IGFBP-1 IREs and the ability of these elements to mediate an insulin response. Therefore, the PEPCK and IGFBP-1 IREs mediate FKHRL1-induced transcription and its inhibition by insulin when this protein is overexpressed, but at the normal cellular concentration of FKHRL1 the insulin response mediated by these elements must involve another protein.

Animals↗
PubMed2000

bis(2-(Acylamino)phenyl) disulfides, 2-(acylamino)benzenethiols, and S-(2-(acylamino)phenyl) alkanethioates as novel inhibitors of cholesteryl ester transfer protein.

A series of bis(2-(acylamino)phenyl) disulfides, 2-(acylamino)benzenethiols, S-(2-(acylamino)phenyl) alkanethioates, and related compounds were synthesized, and their inhibitory effect on cholesteryl ester transfer protein activity in human plasma was evaluated. This study elucidated the structural requirements for inhibitory activity and determined that the optimum compound was S-(2-((1-(2-ethylbutyl)cyclohexane)carbonylamino)phenyl) 2-methylpropanethioate (27) (JTT-705). This compound achieved 50% inhibition of CETP activity in human plasma at a concentration of 9 microM and 95% inhibition of CETP activity in male Japanese white rabbits at an oral dose of 30 mg/kg. It increased the plasma HDL cholesterol level by 27% and 54%, respectively, when given at oral doses of 30 or 100 mg/kg once a day for 3 days to male Japanese white rabbits.

Administration, Oral↗
PubMed2000

Vergence disorders in patients with spinocerebellar ataxia 3/Machado-Joseph disease: a synoptophore study.

Diplopia, a common symptom in spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD) cases, is not always due to asymmetric ophthalmoplegia. We found a Japanese SCA3/MJD family, in which three patients clearly had an impairment of divergence eye movement. We thus quantitatively examined the vergence ranges in eight Japanese SCA3/MJD cases using the synoptophore test. An impairment of the vergence eye movements was found in all patients, and the vergence impairment pattern, but not the ophthalmoplegia pattern, was found to be compatible with the diplopia pattern. The diplopia in SCA3/MJD cases is, therefore, attributed, at least in part, to the impairment of the vergence eye movements.

Abducens Nerve↗
PubMed2000

Indications and technique of sentinel lymph node biopsy in breast cancer using 99m-technetium labeled tin colloids.

BACKGROUND: The status of the sentinel lymph node (SLN) can reflect the status of other lymph nodes in breast cancer. The efficacy of dye injection and radiolabeled tin colloids for the accurate identification of the SLN was investigated. The indications for SLN biopsy for determining clinical nodal status were also investigated. METHODS: A total of 108 patients with breast cancers less than 5 cm were enrolled. Ninety-six patients were clinically node negative and 12 were node positive. About 2 hours before surgery, 1 to 2.5 ml of 99m-technetium-labeled tin colloid was injected around the tumor. Just before the operation, dye was also injected into the tissue surrounding the tumor. Six clinically node negative patients were omitted from the dye-injection process. The SLN was identified as a lymph node with extremely high radioactivity using a gamma probe or a gamma counter. Complete axillary dissection was performed and the metastatic status investigated by hematoxylin and eosin staining. RESULTS: In clinically node negative patients undergoing dye-injection, the SLN was identified in 89 of 90 patients (98.9%), and there was only one patient with lymph node metastasis outside the SLN. However, in clinically node positive patients undergoing dye-injection, the identification rate of the SLN was 66.7% (8 of 12 patients) and there was one patient with lymph node metastasis outside the SLN (12.5%). Without dye-injection, the SLN could be detected in 4 of 6 patients (66.7%). CONCLUSIONS: Successful identification of the SLN with tin colloid requires concomitant dye-injection and candidates for SLN biopsy should be restricted to clinically node negative cases.

Adult↗
PubMed2000

Hepatoid adenocarcinoma of the gallbladder.

We describe here a rare case of hepatoid adenocarcinoma (HAC) of the gallbladder without the production of alpha-fetoprotein (AFP). A 77-year-old man was referred to our division with complaints of general fatigue, loss of appetite, and loss of body weight. A preoperative diagnosis of advanced gallbladder cancer was made, and cholecystectomy with combined resection of two liver subsegments (S4a + S5) and lymph node dissection were performed. Microscopically, the tumor was mainly composed of characteristic cells featuring eosinophilic cytoplasm, enlarged nuclei, and prominent nucleoi, arranged in nests or proliferated in a trabecular pattern. These features were highly suggestive of HAC of the gallbladder, and the tumor cells were negative for AFP immunohistochemical staining. The patient is doing well and has survived for 15 months postoperatively without any recurrence.

Adenocarcinoma↗
PubMed2000

Macrolides and clindamycin suppress the release of Shiga-like toxins from Escherichia coli O157:H7 in vitro.

We investigated the effects of antimicrobial agents fosfomycin (FOS), cefdinir (CDIN), levofloxacin (LEVX), rokitamycin (ROK), roxithromycin (ROX), and clindamycin (CLI) on the release of Shiga-like toxins (SLTs) by enterohaemorrhagic Escherichia coli (EHEC). EHEC was cultured for 14 h in the presence of ROX, ROK or CLI at sub-minimum inhibitory concentrations (subMICs) of 1.56-6.25 mg/l, followed by assay of the level of SLTs in the supernatants using cytotoxicity assay and reversed passive latex agglutination method. Exposure to ROX, ROK or CLI reduced the amount of released SLTs compared with untreated control cultures (P<0.05). These agents however, did not decrease the number of viable EHEC, indicating the importance of bactericidal agents. When the bacteria was exposed to CDIN, FOS or LEVX, the level of SLTs in the culture supernatant increased with the destruction of bacterial cells in the order of CDIN, FOS, LEVX. When 0.5 mg/l of LEVX was added to cultures with or without pretreatment using ROX, ROK, or CLI, the release of SLTs was reduced by this pretreatment (P<0.05). These results may have clinical implications for the treatment of EHEC infection.

Animals↗