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Biomedical subjects

Y Yamada

Publications and source records attributed to Y Yamada.

At least 73 records · Page 4Linked to original sources
PubMed2004

Mutations in the hypoxanthine guanine phosphoribosyltransferase gene (HPRT1) in Asian HPRT deficient families.

Inherited mutation of hypoxanthine guanine phosphoribosyltransferase, (HPRT) gives rise to Lesch-Nyhan syndrome or HPRT-related gout. We have identified 34 mutations in 28 Japanese, 7 Korean, and 1 Indian families with the patients manifesting different clinical phenotypes, including two rare cases in female subjects, by the analysis of all nine exons of HPRT from the genomic DNA and reverse transcribed mRNA using PCR technique coupled with direct sequencing.

Exons↗
PubMed2004

Phase I and pharmacokinetic study of MCC-465, a doxorubicin (DXR) encapsulated in PEG immunoliposome, in patients with metastatic stomach cancer.

BACKGROUND: MCC-465 is an immunoliposome-encapsulated doxorubicin (DXR). The liposome is tagged with polyethylene glycol (PEG) and the F(ab')2 fragment of human monoclonal antibody GAH, which positively reacts to >90% of cancerous stomach tissues, but negatively to all normal tissues. In preclinical studies, MCC-465 showed superior cytotoxic activity against several human stomach cancer cells compared with DXR or DXR-incorporated PEG liposomes. The main purpose of this trial was to define the maximum tolerated dose (MTD), dose limiting toxicity (DLT), recommended phase II dose and pharmacokinetics (PK) of MCC-465. PATIENTS AND METHODS: Patients with metastatic or recurrent stomach cancer were eligible for entry. The initial dose was 6.5 mg/m2. MCC-465 was administered as a 1-h infusion every 3 weeks and the treatment continued for up to six cycles. RESULTS: Twenty-three patients received a total of 62 cycles at the 6.5-45.5 mg/m2 dose level. DLTs were myelosuppression and appetite loss at the 45.5 mg/m2 dose level. Other toxicities were mild. Neither palmar-plantar erythrodysesthesia nor cardiotoxicity was observed. Acute reactions related to infusion were observed commonly in 16 patients over the entire dose range. While no antitumor response was observed, stable disease (SD) was observed in 10 out of 18 evaluable patients. The pharmacokinetic study showed a similar AUC and Cmax to Doxil. CONCLUSION: MCC-465 was well tolerated. The recommended dose for a phase II study of MCC-465, for a 3-week schedule, is considered to be 32.5 mg/m2 in an equivalent amount of DXR.

Adult↗
PubMed2004

Red blood cells regulate eosinophil chemotaxis by scavenging RANTES secreted from endothelial cells.

BACKGROUND: Eosinophils play a critical role in the pathogenesis of allergic diseases. CC chemokines, such as regulated on activation, normal, T cell expressed, and secreted (RANTES), are key regulators of eosinophil locomotion. Although eosinophils migrate from the bloodstream into tissues, mechanisms that generate a chemogradient across the endothelium remain to be fully elucidated. OBJECTIVE: We first examined the polar secretion of RANTES by endothelial cells. We also studied the functional scavenging effect of red blood cells (RBCs) on RANTES secreted into the intravascular side. METHODS AND RESULTS: Endothelial cells were cultured in a transwell chamber with a membrane pore size of 0.45, 3.0, and 8.0 microm and stimulated with TNF-alpha, IL-1beta, or IFN-gamma from the apical or basolateral side for 16 h. The measurement of RANTES in the supernatant was performed by ELISA. We did not see any difference in the amount of RANTES secreted from the cytokine-stimulated endothelium between inner (intravascular side) and outer (extravascular side) wells separated by the 8.0-microm membrane, although apical polarization was observed with the 0.45-microm membrane. The addition of RBCs (hemoglobin (Hb): 0.5-15 g/dL) to the apical supernatant of TNF-alpha-stimulated endothelial cells reduced the RANTES level in a concentration-dependent manner. The treatment of supernatant on the intravascular side with RBCs significantly enhanced the migration of eosinophils. CONCLUSION: RBCs possess a scavenging effect on intravascular RANTES, and thereby regulate transendothelial migration of eosinophils. Our findings suggest a new role of RBCs in allergic inflammation.

Cell Line↗
PubMed2004

Head movement associated with performance of mandibular tasks.

The present study was designed to examine the hypothesis that the motor system controlling phonation is functionally coupled with the motor system controlling posture of the head and neck, as previously suggested (U. Haddar, T.J. Steiner, E.C. Grant and F.C. Rose Human Movement Science 2: 35 and Language and Speech 26: 117). Head tilt and trunk drift in the antero-posterior and right-left directions were measured simultaneously for 20 s before and during three types of speech sounds (/pa/, /ta/ and /ka/) as well during a maximum jaw open-close task in 14 healthy young subjects. The major findings obtained in all of the four tasks were: (i) the trunk drift measured in both directions was negligible in comparison with the head tilt; (ii) the head tilt in the antero-posterior direction was much larger than in the right-left direction and (iii) the head tilt during performance of the four tasks consisted of 'initial' and 'sustained' phases. In the initial phase, the head tilted posteriorly in association with the start of individual tasks. In the sustained phase, the head tilted either anteriorly or posteriorly when the task progressed. The magnitude of the net head tilt in the sustained phase negatively correlated with that of the initial head tilt. These findings indicate that phonation, in the form of jaw open-close, accompanies head movement in two consecutive phases.

Adult↗
PubMed2004

Effects of functional training of dysphagia to prevent pneumonia for patients on tube feeding.

OBJECTIVE: The purpose of this study was to evaluate the effects of functional training on outbreak frequency of pneumonia for the elderly dysphagia patients who were being tube fed. METHODS: Subjects were divided into two groups; one group (n = 10) received oral care (i.e. non-training group) and the other group (n = 11) received functional training of dysphagia in addition to oral care (i.e. training group). The dental health team treated subjects once a week for 3 years (1999-2001). The frequency of pneumonia outbreaks and changes in activities of daily living scale (ADL) were evaluated for each year. RESULT: It was recognised that the frequency of pneumonia in the training group decreased year by year (p < 0.05). Cognitive items in ADL improved in two subjects of the training group. No statistical differences were recognised in the non-training group. CONCLUSION: It was suggested that once-a-week functional training of dysphagia with professional oral care might be effective in preventing pneumonia for elderly people who were being tube fed.

Aged↗
PubMed2004

Virulence of metallo-beta-lactamase-producing Pseudomonas aeruginosa in vitro and in vivo.

We evaluated the virulence of Pseudomonas aeruginosa carrying bla(IMP), a metallo-beta-lactamase gene, and the efficacy of ceftazidime, imipenem-cilastatin, and ciprofloxacin in the endogenous bacteremia model. The presence of bla(IMP) did not practically change the virulence of the parent strain, and ciprofloxacin was effective against infection with P. aeruginosa carrying bla(IMP).

Animals↗
PubMed2004

Postpartum ovarian follicular dynamics and estrous activity in lactating dairy cows.

The objectives of this study were to characterize early postpartum follicular dynamics in dairy cows in relation to their estrual activity and subsequent reproductive performance using 50 (26 primiparous and 24 multiparous) lactating Holstein cows. Ovaries and uterine horns of postpartum lactating cows were examined by ultrasonography 3 times weekly and continued until first services occurred after a 45-d voluntary waiting period. No differences were detected in fertility between primiparous and multiparous cows. In 40 of 50 cows, first postpartum ovulation was observed within 4 follicular waves, and the follicular wave patterns and ovarian cycles in most cows returned to normal as in cattle having normal estrous cycles after the second postpartum ovulation. Cows with the longest intervals from calving to first ovulation produced the most milk and also had prolonged intervals to first estrous activity. Differences in follicular dynamics before first ovulation altered intervals to first estrus, first service, and uterine involution, but these differences did not affect pregnancy rate, number of services, and days open. First postpartum insemination after 3 follicular waves tended to have greater pregnancy rates than those after 2 follicular waves. First inseminations at first estrus could produce greater pregnancy rates than those at subsequent periods of estrus.

Animals↗
PubMed2004

[Pulmonary thromboendarterectomy for an elderly patient].

We describe a case of successful pulmonary thromboendarterectomy for an elderly patient. A 75-year-old female suffered from severe dyspnea in spite of administration of pulmonary vascular dilators and anticoagulants. Her pulmonary vascular resistance was 545 dyn x sec x cm(-5) and, her pulmonary angiogram and perfusion scan revealed that almost all branches of her right pulmonary artery were occluded. Pulmonary thromboendarterectomy was performed under cardiopulmonary bypass. A videoscope was employed to see inside of the pulmonary artery. Flexible aspirator chip was used to peed abnormal intima easily. A non-invasive intracranial oxygen saturation monitor was used for secure circulatory arrest. The duration of cardiopulmonary bypass was 101 minutes and minimum body temperature was 24.5 degrees C. Her symptoms improved markedly after operation, and she went back to the ordinary life. Pulmonary thromboendarterectomy was useful even for elderly patients under some modifications of the operative procedures.

Aged↗
PubMed2004

[Pulmonary embolectomy followed by lobectomy to treat for massive endobronchial bleeding; report of a case].

We describe a case of successful pulmonary embolectomy that required lobectomy to treat for endobronchial bleeding. Sixty-nine-year-old female got into shock required CPR during rehabilitation after replacement of femur head. Her enhanced computed tomography (CT) showed massive embolism in pulmonary artery. Emergency embolectomy was performed under cardiopulmonary bypass (CPB). A videoscope was employed to see inside the pulmonary artery. At the end of the CPB, endobronchial bleeding occurred. The right bronchus was occluded by balloon and CPB was weaned. The right lower lobectomy was done on the next day. She had got pyothorax by methicillin-resistant Staphylococcus aureus (MRSA), and has recovered after intravenous administration of antibiotics and continuous wash out of pleural space by saline containing 0.02% povidon-iodine. Postoperative scan showed no defects of blood flow and ventilation except resected lobe.

Aged↗
PubMed2003

Plasma concentrations of 5-fluorouracil and F-beta-alanine following oral administration of S-1, a dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine, as compared with protracted venous infusion of 5-fluorouracil.

The pharmacokinetics and pharmacodynamics of oral S-1, a dihydropyrimidine dehydrogenase (DPD) inhibitory fluoropyrimidine, were compared with those of protracted venous infusion (PVI) of 5-fluorouracil (5-FU). In all, 10 patients with gastric cancer received PVI of 5-FU at a dose of 250 mg m(-2) day(-1) for 5 days. After a washout period of 9 days, the patients received two divided doses daily for 28 days. S-1 was administered orally at about 0900 and 1900 hours. The daily dose of S-1 in terms of tegafur was 80 mg day(-1) in patients with a body surface area (BSA) of <1.25 m(2), 100 mg day(-1) in those with a BSA of >or=1.25 m(2) to <1.5 m(2), and 120 mg day(-1) in those with a BSA of >or=1.5 m(2). Plasma concentrations of 5-FU and F-beta-alanine (FBAL) were measured for pharmacokinetic analysis, and the plasma uracil concentration was monitored as a surrogate marker of DPD inhibition (pharmacodynamic analysis) in the same patients on days 1-5 of PVI of 5-FU and on days 1-5 of oral S-1. The area under the curve (AUC(0-10 h)) of 5-FU on day 5 was 728+/-113 ng h ml(-1) for PVI of 5-FU and 1364+/-374 ng h ml(-1) for S-1. The median 5-FU PVI : S-1 ratio of the AUC(0-10 h) of 5-FU was 1.9. The AUC(0-10 h) of FBAL on day 5 of PVI of 5-FU was 9465+/-3225 ng h ml(-1), AUC(0-10 h), as compared with 1725+/-605 ng h ml(-1) on day 5 of S-1 treatment. The AUC(0-10 h) of uracil on day 5 was 252+/-60 ng h ml(-1) with PVI of 5-FU and 12 582+/-3060 ng h ml(-1) with S-1. The AUC(0-10 h) of FBAL was markedly lower and plasma uracil concentrations were significantly higher for S-1 than for PVI of 5-FU, clearly demonstrating the effect of DPD inhibition.

Administration, Oral↗
PubMed2003

Remodelling and healing process of moderately heat-treated bone grafts after wide resection of bone and soft-tissue tumors.

INTRODUCTION: In the reconstruction of extensive bone defects after massive resection of malignant musculoskeletal tumors, the clinical results of moderately heat-treated autogenous bone graft have rarely been documented. We evaluated the remodelling and healing process of moderately heat-treated autogenous bone graft by means of imaging features. MATERIALS AND METHODS: The subjects of this study were 19 patients with bone and soft-tissue tumors treated by heat-treated bone graft at our institution between 1992 and 2001, the mean follow-up period was 4.8+/-2.8 years (range 1-9 years). The remodelling and healing process of heat-treated bone graft was evaluated by means of radiography, bone scintigraphy, and MRI. RESULTS: The mean period to obtain bone union between host bone and grafted bone was 9.4 months. Infection was noted in 1 patient, and fracture was present in 2 patients. In 6 patients, pseudoarthrosis was found. Bone scintigraphy showed an increased uptake at the host-graft junction in the period between 3 and 36 months (median 10.7 months) postoperatively. A gradually increased diffuse uptake on the grafted side was evident at an average of 29.1 months (range 19-41 months) postoperatively. High signal intensity on T2-weighted images was observed in the early period after surgery, and iso-intense or low signal intensity became evident after an average of 28.3 months. A gradually increased diffuse uptake on scintigraphy and iso-intense or low signal intensity on T2-weighted images indicated remodelling of the grafted bone. CONCLUSION: Bone union of a moderately heat-treated autogenous bone graft was noted at about 9 months, and its remodelling was proceeding at about 30 months. This method will be useful for bone defects after massive resection of soft-tissue and bone tumors.

Adolescent↗
PubMed2003

Stimulated type I collagen turnover in patients with giant cell tumor of bone.

The aim of this study was to determine type I collagen turnover in giant cell tumor of bone (GCT) by biochemical markers of type I procollagen aminoterminal propeptide (PINP) and type I collagen carboxyterminal telopeptide (ICTP) as synthesis and degradation markers, respectively. The serum concentrations of PINP and ICTP were measured in 11 patients with GCT using radioimmunoassay, and analyzed by the correlation to the grades of GCT progression described by Campanacci. Serum of the 11 healthy subjects was available for comparison. The serum concentration of PINP was significantly higher in patients with GCT (82.4 +/- 46.2 ng/ml) than in controls (40.8 +/- 12.1 ng/ml) (P < 0.01), and that of ICTP was also significantly higher in GCT (5.3 +/- 2.0 ng/ml) than in controls (3.2 +/- 0.8 ng/ml) (P < 0.01). In GCT, the PINP concentration of grade 3 (127.6 +/- 38.8 ng/ml) was higher than that in grade 1 patients (46.9 +/- 4.8 ng/ ml) (P < 0.01). ICTP concentration of both grades 2 (7.1 +/- 1.4 ng/ml) and 3 (5.8 +/- 1.8 ng/ml) patients was significantly higher than that of grade 1 (3.5 +/- 0.6 ng/ ml) patients (P < 0.01, P < 0.05, respectively). Two cases of serum concentration of PINP and ICTP after resection of GCT demonstrated that these biomarkers decreased to the control levels in the absence of GCT. Our results indicated that type I collagen turnover evaluated by ICTP and PINP was stimulated in the presence of GCT. Moreover, this enhanced metabolic turnover reflects the grade of GCT.

Adult↗
PubMed2003

A study on surface roughness and microleakage test in cavities prepared by Er:YAG laser irradiation and etched bur cavities.

The purposes of this study were to investigate the surface morphology, suface roughness of cavities prepared by Er:YAG laser irradiation, and compared the microleakage degree after composite resin restoration with etched bur cavities, in vitro. In each of the 30 human extracted teeth, two shallow cavities were prepared; one prepared with the Er:YAG laser system on the buccal surface, and one produced on the lingual (palatal) surface with a high-speed turbine. Five cavities from each group were investigated by scanning electron microscopy (SEM), and five were subjected to surface roughness analysis by a colour laser three-dimensional (3D) microscope. The remaining cavities were filled with a composite resin and subjected to a microleakage test under thermocycling. Only bur cavities were acid-etched before filling. Statistical analysis was performed using the Mann-Whitney U test; a value of p <0.01 was considered significant. Morphologically, the prepared cavities showed an irregular surface with the absence of a debris-like smear layer; enamel prisms and opening of dentinal tubules were recognised. Surface roughness was significantly increased with the laser system. Microleakage test revealed no significant differences between the laser and bur cavities. Crosscut sections of the cavities with no microleakage showed no gap at the interface. Laser cavity may facilitate good adaptation of composite resin with enamel and dentine, because an increase of surface roughness and the openings of dentinal tubules may facilitate the formation of a hybrid zone, since a primer and an adhesive can penetrate the surface better when the smear layer is removed. It can be concluded that shallow cavity prepared by Er:YAG laser is capable of decreasing microleakage of composite resin restorations, and its efficiency is similar to etched bur cavities.

Acrylic Resins↗
PubMed2003

Effects of an aldose reductase inhibitor on gastroenteropathy in streptozotocin-diabetic rats.

We investigated the effects of epalrestat, an aldose reductase inhibitor (ARI), on gastric emptying, fecal water content, and electrolyte transport in distal colon in streptozotocin (STZ)-induced diabetic rats. We measured gastric emptying time by acetaminophen method and short-circuit-current (Isc) in colonic mucosa using an Ussing chamber. The Isc in response to electric-field-stimulation (EFS) was decreased in untreated rats due to suppression by Cl- secretion. ARI treatment alleviated this suppression (2.7 +/- 0.6 vs. 7.4 +/- 1.1 microA/0.38 cm2 at 8 weeks after treatment, 1.1 +/- 0.2 vs. 7.0 +/- 1.0 at 12 weeks after treatment, P<0.05). In addition, the percentage of fecal water content in untreated rats was significantly lower than in ARI-treated rats (58.0 +/- 2.0 vs. 67.6 +/- 0.8% at 8 weeks, 56.9 +/- 2.1 vs. 63.4 +/- 1.4 at 12 weeks, P<0.05). From STZ injection to 8 weeks, the serum levels of acetaminophen in the diabetic rats were significantly lower than in controls, indicating delayed gastric emptying. At 12 weeks in the diabetic rats treated with ARI, the serum levels of acetaminophen were significantly higher than in the untreated diabetic rats (6.6 +/- 0.4 vs. 3.5 +/- 0.5 microg/ml, P<0.05). ARI-treatment ameliorated delayed gastric emptying without improving glycemic control. These findings show that ARI partially prevented progression of impaired gastric emptying, ion transport, and water transport, and suggest that epalrestat might be useful in the treatment of diabetic gastroenteropathy.

Acetaminophen↗
PubMed2003

Telomerase, p53 and PCNA activity in osteosarcoma.

AIMS: The aim of this study was to investigate telomerase activity and to assess the correlation between telomerase activity, tumor proliferative activity and p53 overexpression in osteosarcoma tumor samples. METHODS: Using a telomerase polymerase chain reaction-enzyme-linked immunoassay based on the telomeric repeat amplification protocol method, we examined telomerase activity in 26 primary osteosarcoma specimens. P53 overexpression was identified using immunohistochemical staining, and tumor proliferative activity was assessed by immunohistochemical staining of PCNA. RESULTS: Telomerase activity was detected at a relatively low level in five of 26 osteosarcoma tissue specimens. P53 was detected in eight of 21 cases. There was no significant correlation between telomerase activity and p53 overexpression (p=0.325). There was a significant correlation between PCNA staining and telomerase activity (p=0.0075). CONCLUSION: Difference between the telomerase activity and p53 overexpression in osteosarcoma suggests that p53 and telomerase may not cooperate in tumor proliferation. Correlation of telomerase activity to PCNA expression suggests that telomerase activity may also useful for evaluate proliferative activity in osteosarcoma.

Adolescent↗