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Biomedical subjects

K Fujii

Publications and source records attributed to K Fujii.

At least 73 records · Page 4Linked to original sources
PubMed2001

Pressure-derived collateral flow index as a parameter of microvascular dysfunction in acute myocardial infarction.

OBJECTIVES: The goal of this study was to examine the implications of the pressure-derived collateral flow index (CFIp) in acute myocardial infarction (AMI). BACKGROUND: Higher CFIp is associated with less severe myocardial ischemia during angioplasty in the non-infarcted heart. It remains unknown whether CFIp also identifies collateral function in AMI patients with and without no-reflow phenomenon. METHODS: The study population included 48 patients with a first AMI. After successful percutaneous transluminal coronary angioplasty (PTCA) stent, we measured mean aortic pressure (Pa), central venous pressure (Pv) and coronary wedge pressure (Pcw) of the infarct-related artery to calculate: CFIp = (Pcw - Pv)/(Pa - Pv). Myocardial contrast echocardiography (MCE) was performed with the intracoronary injection of microbubbles to assess myocardial perfusion. Left ventriculograms at days 1 and 28 were provided for the measurement of the regional wall motion (RWM, SD/chord). RESULTS: There was no difference in CFIp among subsets based on angiographic collateral grades (grade 0, 1, 2, 3; 0.28 +/- 0.07, 0.27 +/- 0.09, 0.27 +/- 0.08, 0.23 +/- 0.08, p = NS). The CFIp was significantly higher in patients with MCE no-reflow (n = 16) than in those with MCE reflow (n = 32) (0.34 +/- 0.07 vs. 0.23 +/- 0.06, p < 0.01). There was a significant inverse correlation between the extent of functional improvement (DeltaRWM[28 d-1 d]) and CFIp (r = 0.56, p < 0.01), implying that higher CFIp is associated with worse functional improvement. CONCLUSIONS: In AMI, CFIp is unlikely to reflect collateral function but seems to increase with the severity of microvascular dysfunction. Because higher CFIp was associated with poorer functional recovery, it provides a simple and useful estimate of clinical outcomes in AMI.

Aged↗
PubMed2001

Separation of WAP-8294A components, a novel anti-methicillin-resistant staphylococcus aureus antibiotic, using high-speed counter-current chromatography.

The WAP-8294A complex was isolated from the fermentation broth of Lysobacter sp. WAP-8294, whose major component, WAP-8294A2, showed a strong activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci in vitro, and also exhibited a potent activity against MRSA in vivo. The previous separation procedure using the conventional chromatographic methods was laborious and time-consuming, and the recovery of the desired compound was often unsatisfactory. In the present study, high-speed counter-current chromatography (HSCCC) was applied to the separation of the main components of the WAP-8294A complex. Due to the high polarity of the target compounds, we selected a hydrophilic two-phase solvent system composed of n-butanol-ethyl acetate-aqueous 0.005 M trifluoroacetic acid (1.25:3.75:5, v/v/v) which provided a suitable range of partition coefficient values for these compounds. Although the settling time of this solvent system was much longer than the optimum range, suggesting a low retention of the stationary phase under the standard experimental conditions, the separation was successfully performed at the low flow-rate of 0.5 ml/min. A sample size of 25 mg yielded pure fractions of three components (1-6 mg). The identification of each component was carried out by HPLC and fast atom bombardment mass spectrometry. The method will contribute to the clinical development of WAP-8294A2 as an anti-MRSA agent.

Countercurrent Distribution↗
PubMed2001

CD44 is the physiological trigger of Fas up-regulation on rheumatoid synovial cells.

CD44 is a ubiquitous molecule known as a hyaluronan receptor. However, the relevance of CD44 to inflammatory processes, for example, rheumatoid synovitis, remains unclear. In this study, we propose a novel function for CD44 using synovial cells from rheumatoid arthritis (RA) patients and demonstrated that CD44 cross-linking augmented Fas expression and subsequent Fas-mediated apoptosis of the cells: 1) cross-linking of CD44 on RA synovial cells markedly augmented Fas expression and its mRNA transcription; 2) engagement of CD44 up-regulated Fas on the cells within 3 h, much more than IL-1beta and TNF-alpha did; 3) the Fas-mediated early apoptotic change of the cells was amplified by CD44 cross-linking; and 4) hyaluronan, especially when fragmented, also augmented Fas-mediated early apoptosis of the cells. Based on these findings, we postulate a new concept: that interaction of CD44 on RA synovial cells with hyaluronan fragments present in the surrounding extracellular matrix augments Fas expression as well as Fas-mediated apoptosis of synovial cells. This may lead to spontaneous growth arrest through Fas-Fas ligand pathway observed in synovial cells of RA synovitis in vivo.

Adjuvants, Immunologic↗
PubMed2001

Abnormal elution behavior of ornitine derivatized with 1-fluoro-2,4-dinitrophenyl-5-leucinamide in advanced Marfey's method.

During the course of establishing the advanced Marfey's method that has been developed to non-empirically determine the absolute configuration of constituent amino acids in a peptide using LC-MS, we encountered the "ornitine mystery" in the di-DLA (2,4-dinitrophenyl-5-leucinamide) derivative such that the elution order of ornitine (Orn) was opposite (D-->L) in spite of their relatively long retention time. In order to resolve this problem, the elution behavior of several mixed DLA and DPEA (2,4-dinitrophenyl-5-phenylethylamine) derivatives with different absolute configurations was carefully observed during HPLC. The length of the methylene chain in basic amino acids was obviously critical for this behavior, because Dab (2,4-diamino-n-butyric acid) and lysine (Lys) did not exhibit this abnormality. The presence of the carboxyamide moiety at the omega position was also essential for this phenomenon, because it was never observed in the DPEA derivatives at the omega position. Furthermore, it was found that the following combination of absolute configurations of Orn and DLA at the omega position only induced this abnormality: D-Orn and L-DLA, and L-Orn and D-DLA. This suggested that the structural interaction such as hydrogen bonding between the carboxyamide of DLA at the omega position and carboxylic acid at the alpha position in these derivatives reduced their retention power on the reversed-phase column.

Amino Acids↗
PubMed2001

Raf-1 promotes cell survival by antagonizing apoptosis signal-regulating kinase 1 through a MEK-ERK independent mechanism.

The Ser/Thr kinase Raf-1 is a protooncogene product that is a central component in many signaling pathways involved in normal cell growth and oncogenic transformation. Upon activation, Raf-1 phosphorylates mitogen-activated protein kinase kinase (MEK), which in turn activates mitogen-activated protein kinase/extracellular signal-regulated kinases (MAPK/ERKs), leading to the propagation of signals. Depending on specific stimuli and cellular environment, the Raf-1--MEK--ERK cascade regulates diverse cellular processes such as proliferation, differentiation, and apoptosis. Here, we describe a MEK--ERK-independent prosurvival function of Raf-1. We found that Raf-1 interacts with the proapoptotic, stress-activated protein kinase ASK1 (apoptosis signal-regulating kinase 1) in vitro and in vivo. Deletion analysis localized the Raf-1 binding site to the N-terminal regulatory fragment of ASK1. This interaction allows Raf-1 to act independently of the MEK--ERK pathway to inhibit apoptosis. Furthermore, catalytically inactive forms of Raf-1 can mimic the wild-type effect, raising the possibility of a kinase-independent function of Raf-1. Thus, Raf-1 may promote cell survival through its protein-protein interactions in addition to its established MEK kinase function.

Animals↗
PubMed2001

Increased expression of P-cadherin mRNA in the mouse peritoneum after carbon dioxide insufflation.

BACKGROUND: Although systemic responses to carbon dioxide (CO(2)) pneumoperitoneum have been studied, there have been few reports of local responses within the peritoneum. We investigated the expression of mRNA for adhesion molecules involved in cell-cell interactions, including ICAM-1, VCAM-1, CD44, E-cadherin, P-cadherin, and N-cadherin, after the induction of a CO(2) pneumoperitoneum in mice. METHODS: Mice were treated with CO(2) pneumoperitoneum (4-6 mmHg for 30 min) and then killed after 24 h, 48 h, and 72 h. The peritoneum of the abdominal wall was resected, and total RNA was extracted by the acid guanidinium thiocyanate-phenol-chloroform extraction procedure, cDNA were synthesized by reverse transcription. Expression of the mRNA for each gene was normalized to that of b-actin for semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The expression of P-cadherin mRNA was significantly increased at 48 h (p = 0.007) and returned to the control level by 72 h after CO(2) pneumoperitoneum. The expression of CD44 increased gradually, reaching a peak at 48 h and returning to the control value by 72 h after CO(2) pneumoperitoneum. Expression of ICAM-1 mRNA was not changed significantly after the application of CO(2). CONCLUSION: The expression of P-cadherin mRNA in the peritoneum can be induced to repair injuries to mesothelial cells caused by CO(2) pneumoperitoneum.

Actins↗
PubMed2001

Stimulation of beta1 integrin down-regulates ICAM-1 expression and ICAM-1-dependent adhesion of lung cancer cells through focal adhesion kinase.

Adhesion molecules are involved in intracellular signaling in various physiological and pathological processes including metastasis and growth of tumor cells. Tumor cells interact with various host cells as well as with extracellular matrices through certain adhesion molecules such as integrins. We here propose that stimulation of beta1 integrin reduces intercellular adhesion molecule (ICAM)-1-mediated interaction of lung cancer cells with CTLs. This concept is based on the following findings: (a) engagement of beta1 integrins on certain lung cancer cells by a specific antibody or by ligand matrices such as fibronectin and collagen markedly reduced ICAM-1 expression on the cell surface and induced sICAM-1; (b) down-regulation of ICAM-1 by stimulation of beta1 integrins was abrogated by tyrosine kinase inhibitors or by transfection of dominant negative truncations of focal adhesion kinase (FAK); (c) engagement of beta1 integrins also reduced ICAM-1-dependent adhesion of lung cancer cells to T cells, a process completely inhibited by tyrosine kinase inhibitors and by transfection of dominant negative forms of FAK; and (d) stimulation of beta1 integrins prevented killing of lung cancer cells by autologous CTLs. In malignant tumors, cancer cells, including lung cancer cells, are surrounded by extracellular matrix proteins such as fibronectin and collagen. This suggests that the engagement of beta1 integrins by matrix proteins potentially occurs in cancer cells in vivo and that continuous stimulation via beta1 integrins reduces ICAM-1-expression, ICAM-1-mediated adhesion of cancer cells to CTLs and their killing by CTLs. Our results suggest that such processes can lead to the escape of lung cancer cells in vivo from immunological surveillance.

Antibodies, Monoclonal↗
PubMed2001

Co-production of microcystins and aeruginopeptins by natural cyanobacterial bloom.

The relationship between Microcystis composition and the production of microcystins and nontoxic peptides in bloom cells, which was regularly collected in Lake Suwa, Japan, in the summer season from 1991 to 1994, was investigated. In order to determine the structures of the nontoxic peptides, we collected large amounts of bloom materials from the same lake on July 23, 1991, and isolated three nontoxic peptides. They were named as aeruginopeptins 917S-A, -B, and -C, and their structures were mainly determined by a mass spectrometry/mass spectrometry (MS/MS) technique as 19-membered cyclic depsipeptides possessing the Ahp (3-amino-6-hydroxy-2-piperidone) moiety. An analysis of the microcystins and aeruginopeptins in the collected blood cells and their Microcystis composition suggested that the M. aeruginosa large cell size produces both microcystins and aeruginopeptins, and the production of both compounds is genetically closely related.

Cell Size↗
PubMed2001

Drug-resistance gene expression and progression of astrocytic tumors.

To clarify the influence of biochemotherapy on the progression of astrocytic tumors, the expression of O6-methylguanine DNA-methyltransferase (MGMT) mRNA, as well as of other drug-resistance- and drug-sensitivity-related genes such as multidrug resistance gene 1, multidrug resistance-associated protein, glutathione S-transferase-pi, DNA topoisomerase II, and interferon receptor mRNA, and the interferon regulatory factor (IRF)-1 and -2 ratios in gliomas were investigated by quantitative reverse transcription-polymerase chain reaction (RT-PCR). The mean MGMT/beta2-microglobulin (beta2-MG) ratio for 130 neuroepithelial tumors was 8.2 +/- 17.8. The mean ratio of 45 glioblastomas was significantly higher than that for the other 85 tumors. In contrast, the mean of 26 low-grade gliomas was significantly lower than that of other tumors. The mean IRF-1/IRF-2 ratio of 16 other brain tumors that mainly consisted of medulloblastomas was significantly greater than that of the other 114 tumors. Almost no significant differences were observed between primary and recurrent tumors in the expression of any gene, and before and after therapy with corresponding drugs. The mean MGMT/beta2-MG ratio in primary glioblastomas was significantly higher than that in secondary tumors. These findings suggest that native drug resistance is more important than acquired resistance when glioma therapy is considered.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Prognostic value of Ki-67 (MIB-1) and p53 in ependymomas.

To determine whether Ki-67 (MIB-1) and p53 have prognostic value in ependymomas, clinicopathologic study was undertaken in 29 patients with this tumor. The clinical course correlated well with the histological grade according to the World Health Organization (WHO) grading system, and it was the worst in patients with anaplastic ependymoma. The percent expression of MIB-1 and p53 correlated with the histological grade of malignancy. With regard to the subtypes of benign ependymoma, the clinical course was the worst in clear-cell ependymoma, which had a significantly higher expression of MIB-1 and p53 than the other subtypes. Tanycytic ependymoma showed the most benign clinical course and the lowest expression of MIB-1 and p53. Although the WHO grading generally tended to correlate with the clinical course of ependymomas, these two subtypes--clear-cell ependymoma and tanycytic ependymoma--exhibited biological properties different from those of other grade II ependymomas.

Adolescent↗
PubMed2001

Bilateral crossed cerebello-cerebral diaschisis and mutism after surgery for cerebellar medulloblastoma.

A 7-year-old boy developed mutism after surgery for cerebellar medulloblastoma. Postoperative magnetic resonance imaging (MRI) showed atrophy of the cerebellar vermis and both cerebellar hemispheres, predominantly on the right side. Single photon emission computed tomography (SPECT) with technetium-99m-ethyl cysteinate dimer (Tc-99m ECD) revealed decreased cerebral blood flow (CBF) in the bilateral thalami, bilateral medial frontal lobes, and left temporal lobe in addition to the cerebellar vermis and both cerebellar hemispheres when mutism was manifest, indicating the existence of bilateral crossed cerebello-cerebral diaschisis (BCCCD). Circulatory disturbance in both cerebellar hemispheres secondary to tumor resection probably caused BCCCD in both cerebral hemispheres, predominantly in the left, via the dentatothalamocortical pathway (DTCP). With recovery of his mutism, CBF increased in the right thalamus, bilateral medial frontal lobes and left temporal lobe. Thus BCCCD was improved, with only a slight decrease in CBF still persisting in the left thalamus. The mechanism of mutism may have involved damage to the cerebellar vermis (the site of incision at operation), the left dentate nucleus (heavily infiltrated by the tumor) and the right dentate nucleus of the cerebellum (affected by circulatory disturbance secondary to acute postoperative edema). The SPECT findings suggested that mutism was associated with BCCCD-induced cerebral circulatory and metabolic hypofunction in the supplementary motor area mediated via the DTCP.

Cerebellar Neoplasms↗
PubMed2001

Efficacy of intraperitoneal and intravenous chemotherapy and left upper abdominal evisceration for advanced gastric cancer.

BACKGROUND: The study was carried out to evaluate the efficacy of intraperitoneal (i.p.) and intravenous (i.v.) chemotherapy, as well as left upper abdominal evisceration (LUAE), for patients with advanced gastric cancer. METHODS: We carried out a retrospective study of 348 patients who underwent gastrectomy for advanced gastric carcinoma between 1978 and 1998 at our institution and who had macroscopic type 3 or 4 cancer (Japanese classification) with depth of invasion to the serosal surface, but no liver metastasis or lymph node metastasis around the abdominal aorta. Cumulative survival rates were compared in patients who underwent gastrectomy together with: (1) intraoperative i.p. chemotherapy alone, (2) postoperative i.v. chemotherapy alone, (3) both i.p. and i.v., or (4) no chemotherapy. Then patients were stratified according to the presence of peritoneal dissemination (P+) and its absence (P-). In P+ patients, survival was compared between those who received i.v. chemotherapy and those who did not, and between those who received i.p. chemotherapy and those who did not. Then, survival was compared between patients with high and low immunosuppressive acidic protein (IAP) levels. Finally, we compared cumulative survival rates in patients (stratified as P+ and P-) who underwent LUAE with cumulative survival rates in those who underwent total gastrectomy combined with resection of the pancreatic body, tail, and spleen (PS). RESULTS: For P- patients, there was no survival advantage with adjuvant i.p. or i.v. therapy when compared with surgery alone. For P+ patients, however, there was an improvement in survival when patients received both i.p. and i.v., compared with survival with surgery alone (P < 0.05). In P+ patients aged less than 60 years, there was improvement in survival for those who underwent i.p. therapy together with surgery (P < 0.05), but not for those who had i.v. chemotherapy after surgery. When LUAE was examined, there was a survival advantage for this procedure when there was no peritoneal dissemination. Four long-term survivors (surviving for more than 5 years) were identified in our study. Three of the 4 patients were aged less than 60 years, and all 4 had macroscopic type 4 gastric cancers. CONCLUSION: Although the prognosis for patients with invasive type gastric cancer remains poor, there have been a few long-term survivors, in whom this survival was associated with aggressive combination therapy, including surgery, i.p., and i.v. therapy. P+ patients aged less than 60 years and patients with type 4 gastric cancer may stand to benefit most from such therapy. For P- patients, the role of adjuvant i.p. or i.v. therapy continues to be ambiguous, although LUAE in this population may be superior to PS.

Adult↗
PubMed2001

Molecular characterization of the ERGIC-53 gene in two Japanese patients with combined factor V-factor VIII deficiency.

Combined deficiency of factor V and factor VIII is a distinct clinical entity and is an autosomal recessive disorder. Recently identification of the gene, the endoplasmic reticulum-Golgi intermediate compartment (ERGIC-53), responsible for combined factor V-factor VIII deficiency and mutations of the ERGIC-53 gene in affected patients have been reported. In this report we analyzed two Japanese patients with combined factor V-factor VIII deficiency by genomic polymerase chain reaction and sequencing analysis. In one patient we found a point mutation of C to T at nucleotide 604 in exon 5, resulting in a transition of arginine to stop codon, which was reported in previous reports. The DdeI digestion study demonstrated that this patient is homozygous for this nonsense mutation. In the other patient we found no mutation in the ERGIC-53 gene in analysis of the entire coding region and the intron/exon junctions, which is also consistent with the previous reports, suggesting the possibility of defects at other genetic loci.

Factor V Deficiency↗
PubMed2001

Spinal tanycytic ependymomas.

Three cases of spinal tanycytic ependymoma are reported, a man aged 45 years and two women aged 36 and 55 years. Each patient developed gradual paraparesis over a few months prior to admission. Magnetic resonance imaging showed an enhancing, well-circumscribed tumor in the spinal cord in each case. Histologically, the tumors consisted of monotonous proliferation of long spindle cells with markedly eosinophilic cell processes; focally forming perivascular pseudorosettes. The tumor cells were strongly immunopositive for glial fibrillary acidic protein, S-100 protein and vimentin. Ultrastructurally, in addition to massive intermediate filaments, many tumor cells showed abundant microtubules. Well-developed desmosomes and microvilli/cilia-lined microlumina were occasionally observed. The tumors were grossly totally removed and the patients remain recurrence free at 9, 9, and 2 years postoperatively. Reviewing reported cases including our three cases, tanycytic ependymoma may occur frequently in spinal cord, especially in the cervical region of the spinal cord. Since histologically it resembles pilocytic astrocytoma and schwannoma, tanycytic ependymoma should be included in the differential diagnosis of benign spindle cell tumors of the central nervous system.

Adult↗
PubMed2001

Predictive factors for development of the no-reflow phenomenon in patients with reperfused anterior wall acute myocardial infarction.

OBJECTIVES: We sought to elucidate the clinical factors related to the development of no-reflow phenomenon after successful coronary reperfusion in patients with an acute myocardial infarction (AMI). BACKGROUND: Myocardial contrast echocardiography revealed that the no-reflow phenomenon is observed in some patients with a reperfused AMI, and those patients usually have poor functional and clinical outcomes. It is still unknown what clinical factors are related to the development of the no-reflow phenomenon. METHODS: Myocardial contrast echocardiography was performed 15 min after successful coronary reperfusion therapy in 199 patients with an anterior wall AMI who underwent successful coronary reperfusion with primary coronary angioplasty within 24 h after the onset of AMI. Multiple logistic regression analysis was used to identify independent predictors of the no-reflow phenomenon. RESULTS: Seventy-nine patients showed the no-reflow phenomenon. Univariate analysis indicated that pre-infarction angina within 48 h before symptom onset, Killip class, Thrombolysis in Myocardial Infarction flow grade 0 on the initial coronary angiogram, the number of abnormal Q-waves and the wall motion score (WMS) on the echocardiogram obtained at hospital admission are related to the no-reflow phenomenon. Multivariate logistic regression analysis revealed that all of these factors, except for Killip class, are independent predictive factors of the no-reflow phenomenon. CONCLUSIONS: Development of the no-reflow phenomenon is related to the severity of myocardial damage (number of Q-waves), the size of the risk area (WMS) and the occlusion status of infarct-related artery. In addition, ischemic preconditioning (pre-infarction angina) seems to be the factor that attenuates the no-reflow phenomenon.

Adult↗
PubMed2001

Lysyl oxidase-catalyzed cross-linking and insolubilization reactions of Lys-containing polypeptides and synthetic adhesive proteins.

The lysyl oxidase- (LO-) mediated insolubilization reactions of the Lys-containing polypeptides have been examined using poly(L-Lys) with degrees of polymerization (Dps) ranging 1 from 2300, copoly(LysxAlay) (x:y = 1:4, 1:3; 1:1, 2:1, and 3:1), copoly(LysxGlyy) (x:y = 1:1 and 2:1), and synthetic adhesive proteins with sequential repetitive units enriched in the Lys residues, poly(Ala-Lys-Pro-Ser-Tyr-Pro-Pro-Thr-Tyr-Lys), poly(Ala-Gly-Tyr-Gly-Gly-Ala-Lys), and poly(Gly-Gly-Gly-Tyr-Gly-Gly-Tyr-Gly-Lys). All of the substrates were insolubilized by the LO-catalyzed oxidation of the epsilon-amino group in the Lys residues. The Dps of the polypeptide substrates did not affect the kinetic constants, the Km and Vmax values. The Km and Vmax values and the insolubilization rates varied depending on the Lys contents in the substrate polypeptides, which were enriched in Gly and Ala residues. As the Lys content increased, the Km and Vmax values became lower and higher, respectively. The insolubilization rates decreased with increase of the Lys content. The time-dependent changes in the LO-catalyzed aldehyde production, the insolubilization, and remaining LO activity demonstrated that the cross-linking and the insolubilization steps occurred along with LO deactivation, indicating that the enzymatic and chemical processes in the LO-mediated insolubilization occur in order.

Adhesives↗
PubMed2001

85Kr measurement system for continuous monitoring at the Meteorological Research Institute, Japan.

A 85Kr measurement system for continuous monitoring based principally on the BfS-IAR method (activity measurement of 85Kr by gas counting coupled with gas chromatographic separation, using pure CH4 as carrier and Counting gas) was implemented for the first time in Japan. In this paper, a detailed description of the system and procedures is given and the inter-comparison results of our system with the BfS-IAR system are presented. A consistent temporal concentration change with high accuracy and consistency of the respective data with the BfS-IAR data (maximum difference of 5%) were achieved with the Meteorological Research Institute (MRI) system, which shows that the system is valid and reliable for the purpose of background monitoring for 85Kr in air. Also, the 85Kr monitoring record at the MRI during 1995-2001 is described. The record distinctively shows the Northern Hemispheric background 85Kr concentrations at the mid-latitude and the elevated concentrations affected by the operation of a nuclear fuel reprocessing plant in Tokai-mura, Ibaraki. Japan.

Air Pollutants, Radioactive↗