Search PubMed⌕ Search

Biomedical subjects

Y Fujii

Publications and source records attributed to Y Fujii.

At least 343 records · Page 19Linked to original sources
PubMed1999

Blood flow velocity in the middle cerebral artery response to tourniquet release.

This study was undertaken to examine the effects of tourniquet release on middle cerebral arterial (MCA) blood flow velocity in patients undergoing general anaesthesia for orthopaedic surgery. In 30 patients (ASA physical status 1 or 2) undergoing orthopaedic procedures on the upper (Group U, n = 15) and lower (Group L, n = 15) extremities, MCA blood flow velocity was measured before and after tourniquet deflation using transcranial Doppler sonography. The MCA blood flow velocity increased after release of the intraoperative tourniquet and remained elevated for two minutes in Group U (P < 0.05) and for four minutes in Group L (P < 0.05). The increase in MCA blood flow velocity was greater in Group L than in Group U (P < 0.05). A positive linear correlation between MCA blood flow velocity and PETCO2 after tourniquet deflation was observed in both groups (P < 0.001).

Adult↗
PubMed1999

An experimental study of radiation-induced cognitive dysfunction in an adult rat model.

The objectives of this study were to establish an adult rat model for the late onset of radiation-induced cognitive dysfunction and to compare behavioural dysfunction with histopathological changes. While under anaesthesia, 30 rats (experimental group) were irradiated with a total dose of 40 Gy, given as eight fractions in 24 days. Another 30 rats (control group) underwent sham irradiation. The cognitive functions of all rats were evaluated at 6, 9 and 12 months after irradiation using the Morris water maze and passive avoidance tasks. Histopathological examination of these rats was carried out after the evaluation of cognitive functions was complete. At 6 and 9 months after irradiation there were no significant differences between the control and irradiated groups in passive avoidance and water maze tests. At 12 months after irradiation, the passive avoidance task revealed a deterioration of cognitive function in the experimental group. Histopathological observations revealed no abnormal findings in the irradiated brains at the light microscope level. Late onset cognitive dysfunction following cranial irradiation was observed in an adult rat model. Pathological investigations showed no abnormalities in the irradiated brains. These findings indicate that radiation-induced cognitive dysfunction can precede morphological changes in the brain or that they arise without them. The present model seems useful for elucidating the pathogenesis of radiation-induced cognitive dysfunction and for developing methods for therapy and prophylaxis.

Age Factors↗
PubMed1999

Effects of certain cerebral circulation activating drugs on regional cerebral blood flow in rats.

The effects of certain cerebral circulation activating drugs on regional cerebral blood flow (rCBF) in the frontal cortex (FCOR), hippocampus (HPC) and nucleus caudatus (CAD) were investigated using the hydrogen clearance method in rats. All the drugs used in the present study, i.e., ozagrel, ifenprodil, pentoxifylline, cinnarizine and dilazep, caused an increase in rCBF in the FCOR, HPC and CAD. Ozagrel was the most potent in increasing rCBF at the FCOR. Ozagrel, ifenprodil, cinnarizine and dilazep were more effective than pentoxifylline in increasing rCBF at the HPC. On the other hand, all the drugs showed almost the same potency in increasing rCBF at the CAD. These results suggested that measurement of rCBF is useful for estimating the efficacy of cerebral circulation activating drugs.

Anesthesia↗
PubMed1999

Effects of anabolic steroid (19-nortestosterone) on the secretion of testicular hormones in the stallion.

The aim of this study was to clarify the effect of anabolic steroids on the testicular endocrine function of mature stallions. Mature thoroughbred stallions were treated with 800 mg nandrolone decanoate every 3 weeks for 3 months. After the first treatment, plasma concentrations of LH, immunoreactive inhibin and testosterone decreased rapidly to the nadir. These hormones were maintained at significantly lower concentrations compared with concentrations in intact stallions. Histology of the testicular tissue indicated the arrest of advanced spermatogenesis in the seminiferous tubules and a severe depletion of the number of Leydig cells in the interstitial compartment as a result of treatment. Most of the immunopositive cells for the inhibin alpha-subunit and steroidogenesis enzymes in the interstitial compartment decreased below detectable amounts, whereas immunopositive reactions of inhibin alpha-subunit in the seminiferous tubules were clearly observed. In conclusion, the treatment of mature stallions with nandrolone decanoate caused a decrease in the secretion of ir-inhibin and testosterone from the testis, the depletion of the number of Leydig cells and a decrease below detectable amounts of inhibin alpha-subunit and steroidogenesis enzymes. The concentration of ir-inhibin in the peripheral blood may be a useful marker for the examination of testicular activity in stallions being treated with anabolic steroids.

3-Hydroxysteroid Dehydrogenases↗
PubMed1999

Effective delivery of a lipophilic 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) into rat lymphoid tissues.

Lipophilic 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) was evaluated for its improved lymph node delivery by comparison with the parental nucleoside (ddG) in vitro and in vivo. The in vitro studies with rat plasma, lymph node homogenate and stomach content indicated that 6-Cl-ddG converted to ddG more effectively in the lymph node homogenate and that 6-Cl-ddG was more stable than ddG in the stomach content. In an in vivo study, plasma and lymph nodes were collected from rats after a subcutaneous or oral administration of 6-Cl-ddG or ddG. With the subcutaneous administrations of the drugs, the area under the concentration time-curve (AUC) value in the plasma for converted ddG following a 6-Cl-ddG administration was less than half the value for ddG following a ddG administration but the converted ddG AUC values in the lymph nodes due to 6-Cl-ddG administration were 1.4- to 2.0-fold higher than the ddG AUC values due to ddG administration. Moreover, with the oral administrations, the converted ddG AUC value in plasma after a 6-Cl-ddG administration was 3-fold higher than ddG after a ddG administration, and high levels of converted ddG were detected in the lymph nodes, but no ddG was detected in the lymph node following ddG administration. These results suggest that lipophilic 6-Cl-ddG is a useful prodrug for delivering ddG into the lymph nodes by oral administration.

Administration, Oral↗
PubMed1999

[Separate measurement of radial trabecular and cortical bone mineral density by peripheral quantitative computed tomography (pQCT) in degenerative joint disease].

Degenerative joint disease and osteoporosis, both of which tend to increase with advance in age, were thought to be essentially different mainly because of the artifactually high lumbar spine bone mineral density (BMD) in the former unlike osteoporosis characterized by persistent decrease of BMD. To clarify the relationship between these two diseases, three-dimensional BMD of the trabecular and cortical bone was measured separately in an area of the radius relatively free of degenerative changes by peripheral computed tomography (pQCT). In addition to radiological assessment of spondylosis deformans, quantification of vertebral deformity was attempted by calculation of standard deviation, coefficient of variation, difference between maximum and minimum density divided by the mean of L1-L4. With advance in age and progress of spondylosis deformans, the standard deviation, coefficient of variation difference between the maximum and minimum density and this difference divided by the mean of L1-L4 increased, but radial trabecular bone density, cortcal density and relative cortical volume decreased, suggesting parallel advance of degenerative joint disease and osteoporosis. Sodium etidronate, an antiresorber commonly used in the treatment of osteoporosis, increased mean lumbar spine BMD and markedly decreased the standard deviation, coefficient of variation, difference between the maximum and minimum density and this difference divided by the mean of L1 and L2 but maintained maximum BMD constant, decreasing vertebral deformity due to spondylosis deformans. It is conceivable that calcium release from bone on increased resorption leads to osteoporosis, and calcium entrance into cartilage, causing its hardening, disappearance and degeneration, direct contact between bones, osteoarthritis and subsequent deformity in a single sequence of events.

Absorptiometry, Photon↗
PubMed1999

Clinical application of three-dimensional anisotropy contrast magnetic resonance axonography. Technical note.

The utility of three-dimensional anisotropy contrast (3DAC) magnetic resonance (MR) axonography, a method sensitive to neuronal fibers and their directionality, was investigated in the clinical setting using a 3-tesla MR imaging system based on a General Electric Signa platform. The study focused on healthy volunteers and patients with common structural central nervous system disorders, namely chronic infarction, brainstem cavernous hemangioma, supratentorial meningioma, and astrocytoma. Three orthogonal anisotropic diffusion-weighted images were first obtained. Three primary colors were each assigned to a diffusion-weighted image, respectively, and the images were subsequently combined into a single-color image in full-color spectrum (3DAC MR axonography image). Fiber-tract definition in the cerebral peduncle of the midbrain of healthy volunteers showed intersubject variation, with two general patterns recognized: dispersed (60% of cases) and compact (40% of cases). Pathological alterations in the fiber tracts were readily identified in cases involving wallerian degeneration of the pyramidal tract, as illustrated in the cases of chronic infarction. Displacement of major tracts, such as the medial lemniscus or corticospinal tract, as well as fiber directionality, was also easily recognized in cases of mass lesions. As an imaging method uniquely capable of providing information regarding axonal connectivity, 3DAC MR axonography appears to have promising potential for routine clinical application.

Astrocytoma↗
PubMed1999

[A study of employment anxiety in college women].

The purpose of this study was to develop "Employment Anxiety Scale" to understand the structure of anxiety accompanying employment seeking. First, 30 items of anxiety related to employment seeking were collected with an open-ended questionnaire, for which 65 female students answered. In the main study, 465 female undergraduates filled out a questionnaire of the thirty items, a stress scale, and a self-report depression scale. Factor analysis found three factors for the anxiety items: employment seeking activity, vocational aptitude, and workplace. Multiple regression analysis was performed to examine the relationship between the mental-health scales and the anxiety. The dependent variables were the stress and depression scores, and the predictors the subscale scores of Employment Anxiety Scale. Results showed that anxiety accompanying employment-seeking activity was highly predictive of the mental-health scores.

Adult↗
PubMed1999

[Effects of HCFU and TNP 470 on liver metastasis of BALB/c retroperitoneal sarcoma (LMFS)].

Combination therapy using HCFU and TNP 470, which inhibits angiogenesis, was examined for effectiveness against the footpad injection model of LMFS tumor. This LMFS, a retroperitoneal sarcoma of BALB/c mice, proliferated at the inoculation site (100% take) and all mice operated on after day 15 had spontaneous metastatic nodules in the liver. Mice with the LMFS tumor were given HCFU and 5-FU (5 days/week), and/or TNP 470 (3 days/week) from day 3 for 3 weeks and sacrified at day 28 under anesthesia. Seven of 10 mice receiving 5-FU and TNP 470 died from the side effects of the drugs. Mean tumor weight and liver metastatic nodules were determined and compared with a control group. The results were as follows: HCFU group: 94.6%, 11.8%, 5 FU group: 73.9%, 28.8%, TNP 470 group: 67.6%, 44%, HCFU and TNP 470 group: 33.3%, 6.4%. Mice with LMFS were given HCFU and/or TNP 470 from day 3 for 4 weeks. The foot on the injected side was amputated on day 15, and the animals were sacrified on day 35. Liver metastatic nodules compared with those of the operation (OP) group as follows: OP + HCFU group: 14.4%, OP + TNP group: 39.1%, and OP + HCFU + TNP 470 group: 5.4%. Histologically, 5 of 5 mice of the OP group, 3 of 5 of the OP + HCFU group, 4 of 5 of the OP + TNP 470 group and 1 of 5 of the OP + HCFU + TNP 470 group had liver metastases. These results show that while either HCFU or TNP 470 is effective by itself, a combination of these drugs is more effective against liver metastasis.

Angiogenesis Inhibitors↗
PubMed1999

Biological characteristics and prognostic value of in vitro three-drug resistance to prednisolone, L-asparaginase, and vincristine in childhood acute lymphoblastic leukemia.

The purpose of this study was to investigate the biological characteristics and prognostic value of in vitro three-drug resistance to prednisolone, L-asparaginase, and vincristine in childhood acute lymphoblastic leukemia (ALL). We carried out in vitro tests with a 4-day culture and a methyl-thiazol-tetrazolium assay on bone marrow samples from 209 children newly diagnosed with ALL. After testing the resistance of leukemic cells to 14 drugs, we classified the patients into two groups according to their sensitivity to three drugs (prednisolone, L-asparaginase, and vincristine) used in remission induction therapy. The three-drug resistant group (RR: sensitive to no drugs or to one drug) correlated with both short-term and long-term treatment failure. Three-year event-free survival (95% confidence interval) for the sensitive group (SS: sensitive to two or three drugs) was 0.813 (0.773-0.853) and that of the RR group was 0.616 (0.569-0.669) (P = 0.0001). Univariate analysis showed that Philadelphia-chromosome (Ph1) positivity and immunophenotype of mixed lineage were also prognostic factors in the 209 patients. The prognosis of the SS/RR drug resistance profile within 14 Ph1 patients was marginally significant (P = 0.062). Multivariate Cox regression analysis showed that Ph1 was an overwhelmingly adverse factor in event-free survival, with a relative hazard of 5.37 (2.57-11.21, P < 0.0001), followed by RR, with a relative hazard of 2.98 (1.69-5.25, P = 0.0001). Furthermore, we clarified the characteristics of the RR group by examination of the pattern of drug resistance to other drugs in comparison with the SS group. The leukemic cells of RR patients were more resistant than those of SS patients (P < 0.0001) to all the drugs tested, with resistance ratios of 1.6 to 13.1 (mean 3.4). In conclusion, in vitro three-drug resistance at the initial stage is an important independent predictor of treatment failure for both induction response and long-term outcome in childhood ALL.

Adolescent↗
PubMed1999

Effects of histamine and related compounds on regional cerebral blood flow in rats.

The effects of histamine and related compounds on regional cerebral blood flow (rCBF) in the hippocampus of conscious rats were studied. Intracerebroventricular injection of histamine caused a dose-dependent increase in rCBF in the hippocampus, and similar findings were observed with not only the H1 agonist, 2-thiazolylethylamine, but also the H2 agonist, dimaprit. Intraperitoneal injection of L-histidine also resulted in an increase in rCBF in the hippocampus, in parallel with elevation of histamine content in the brain. The increase in rCBF in the hippocampus induced by L-histidine was antagonized by both H1 and H2 antagonists (diphenhydramine, pyrilamine and zolantidine). In addition, when both antagonists were injected simultaneously, an additive effect was observed in antagonism of the L-histidine-induced increase in rCBF. L-Histidine caused no marked changes in blood pressure even at a dose of 1,500 mg/kg, which showed an increase in rCBF in the hippocampus. These results indicate that histamine elicited an increase in rCBF via both H1 and H2 receptors.

Animals↗
PubMed1998

'Musical brain' revealed by high-field (3 Tesla) functional MRI.

The cortical areas subserving music literacy were investigated using high-field (3 Tesla) functional magnetic resonance imaging (fMRI). The activation pattern associated specifically with music score reading was compared with that associated with reading text in a subject's primary and secondary language. While the areas of activation were predominantly identical for all three reading modalities, there were areas within the occipital cortex activated exclusively by music score reading. Grand analysis of the activation patterns of eight pianists unequivocally identified that the principal cortical area needed for music literacy is the cortex flanking the right transverse occipital sulcus (musical brain).

Adult↗
PubMed1998

Detailed deletion mapping suggests the involvement of a tumor suppressor gene at 17p13.3, distal to p53, in the pathogenesis of lung cancers.

The short arm of chromosome 17 is one of the most frequently affected chromosomal regions in lung cancers, while there is solid evidence that the p53 gene at 17p13.1 is a target for frequent 17p deletions. In the present study, we re-evaluated 17p deletions in lung cancers by conducting a detailed analysis of the minimum deleted region(s) on 17p with reference to the p53 gene status in each 100 primary lung cancer cases. In addition to the p53 locus at 17p13.1, the presence of an independent, commonly deleted region(s) at 17p13.3 was identified. Furthermore, loss of heterozygosity (LOH) at 17p13.3 was shown to be even more frequent than that at 17p13.1 and it appeared to occur in the absence of p53 mutation and/or 17p13.1 deletion. These results suggest that in addition to the p53 gene at 17p13.1, an as yet unidentified tumor suppressor gene(s) residing at 17p13.3 might play a role in lung carcinogenesis possibly in an earlier phase than the p53 gene. This would warrant future studies to identify the putative tumor suppressor gene at 17p13.3 in order to gain a better understanding of the molecular pathogenesis of this fatal disease.

Adenocarcinoma↗
PubMed1998

Evidence that CD31, CD49b, and CD62L are immunodominant minor histocompatibility antigens in HLA identical sibling bone marrow transplants.

Despite complete matching of siblings for the HLA loci, after bone marrow transplantation (BMT), approximately 20% develop graft-versus-host disease (GVHD). This is presumably due to incompatibility of minor histocompatibility antigens (mHa). We investigated the polymorphisms of 14 adhesion molecules (CD2, CD28, CD31, CD34, CD36, CD42, CD44, CD48, CD49b, CD54, CD62L, CD86, CD102, and CD106) in Japanese subjects and their association with the occurrence of GVHD after allogeneic HLA identical BMT. Six molecules (CD2, CD31, CD42, CD49b, CD54, and CD62L), which were found to be polymorphic, were then examined in 118 HLA identical sibling donors and recipients who had undergone BMT. Association of the incompatibility of the polymorphic molecules with the presence or absence of GVHD was examined. In these six, we observed a significant correlation between acute GVHD and the compatibility of CD31 (codons 563/670) (Pcorrected = .018), and CD31 (codons 563/670) + CD62L (Pcorrected = .018) in patients with the HLA-B44-like superfamily. In patients with the HLA-A3-like superfamily, the compatibility of CD62L (Pcorrected = .03) and CD62L + CD49b (P = . 004, Pcorrected = .078) was associated with acute GVHD. Therefore, CD31, CD49b, and CD62L might be candidates for immunodominant mHa.

Adolescent↗
PubMed1998

Crystallographic characterization of Pap1-DNA complex.

Pap1 is a fission yeast transcription factor that activates genes related with resistance against staurosporine, a potent inhibitor of protein kinase C, and has been shown to be involved in cell growth, cell cycle, carcinogenesis and differentiation. Pap1 has the bZIP DNA-binding domain but binds to non-consensus DNA sequences for the bZIP motif. Highly ordered crystals of the DNA-binding domain complexed with a DNA fragment that has an ATF/CREB-like non-consensus sequence have been obtained. The crystals grew by the vapor-diffusion technique with polyethylene glycol 6000 and belong to space group R3 with a = b = 240.78, c = 43.85 A. A 2.0 A resolution data set was collected with a cryo-crystallographic technique.

Basic-Leucine Zipper Transcription Factors↗
PubMed1998

The effects of histamine H3-receptor antagonists on amygdaloid kindled seizures in rats.

The effects of histamine H3-receptor antagonists, thioperamide, and clobenpropit on amygdaloid kindled seizures were investigated in rats. Both intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) injections of H3-antagonists resulted in a dose-related inhibition of amygdaloid kindled seizures. An inhibition induced by thioperamide was antagonized by an H3-agonist [(R)-alpha-methylhistamine] and H1-antagonists (diphenhydramine and chlorpheniramine). On the other hand, an H2-antagonist (cimetidine and ranitidine) caused no antagonistic effect. Metoprine, an inhibitor of N-methyltransferase was also effective in inhibiting amygdaloid kindled seizure, and this effect was augmented by thioperamide treatment.

Amygdala↗
PubMed1998

Membrane-type 1 MMP (MMP-14) cleaves at three sites in the aggrecan interglobular domain.

An aggrecan G1-G2 substrate was used to determine sites within the interglobular domain that were susceptible to cleavage by MT1-MMP. Degradation products were identified by Western blotting with neo-epitope antibodies specific for MMP-derived N- and C-terminal sequences. The results showed that MT1-MMP cleaved at the N341-F342 and D441-L442 bonds, as shown for other MMPs, and also at a site 13 amino acids C-terminal to the N341-F342 site. The G2 product of this additional cleavage was identified by sequence analysis and revealed an N-terminus commencing T355VxxPDVELPLP. The data are consistent with MT1-MMP cleavage at three sites in the aggrecan interglobular domain; one at N342-F342, a second at D441-L442 and a third at Q354-T355.

Aggrecans↗