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H Fujii

Publications and source records attributed to H Fujii.

At least 595 records · Page 33Linked to original sources
PubMed1994

[An apparatus using the laser speckle phenomenon for non-invasive two-dimensional analysis of retinal microcirculation].

A new instrument using the laser speckle phenomenon for non-invasive two-dimensional analysis of the retinal microcirculation was developed. The fundus was illuminated with an argon laser spot and its image speckle was detected with an area sensor. The difference between the average of output data (Imean) and output data for successive scannings of the image speckles at the sensor plane was calculated and integrated to give Dmean, and Imean/Dmean is defined as normalized blur (NB), which is a quantitative index of blood flow velocity. The results were displayed in color graphics showing the two-dimensional variation of the NB level in the area of interest. The NB had a good correlation with the speed of rotation of the ground glass in a range between 5 and 120 mm/sec. Using this instrument, the effect of intraocular pressure (IOP) on the microcirculation of the rabbit retina was studied. The coefficient of reproducibility was 9.2% when measured in the same area twice at 5-minute intervals. A stepwise reduction in the ocular perfusion pressure (OPP) was introduced by elevating the IOP manometrically. The NB in the retina was little affected by OPP change when OPP was above 50 mmHg, but below this value the NB decreased as the OPP decreased.

Animals↗
PubMed1994

[Noninvasive two-dimensional analysis of microcirculation in optic nerve head and choroid--calibration of the normalized blur (NB) value].

We have developed an apparatus using the laser speckle phenomenon for noninvasive two-dimensional measurements of the fundus microcirculation. The normalized blur of the speckle pattern (NB value) was adopted as an index of blood flow velocity in the tissue. The present study investigated whether the NB value can be also used as a quantitative index of the blood flow rate in the tissue. In experimental animals, an injection of a lethal dose of pentobarbital causes rapid reduction in the ocular perfusion pressure (OPP), which linearly correlates with blood flow rate in the ocular tissue. The NB in rabbit optic nerve head (ONH) tissue showed a linear correlation (r = 0.98, p < 0.001) with the OPP after injection of a lethal dose of pentobarbital, which suggested that the NB value parallels the blood flow rate in the ONH tissue. At various levels of OPP, the choroidal NB showed a good correlation (r = 0.60, p < 0.001) with the choroidal blood flow rate measured with microsphere technique. These results indicated that the NB value can be used as a quantitative index not only for the blood flow velocity but also for the blood flow rate in the tissue.

Animals↗
PubMed1994

[Noninvasive two-dimensional analysis of retinal microcirculation using the laser speckle phenomenon--II. Comparison of results with those obtained with the microsphere technique].

We have recently developed an apparatus for noninvasive two-dimensional analysis of the retinal microcirculation using the laser speckle phenomenon. The fundus is illuminated by an argon laser spot and its image speckle is detected by an area sensor. The difference between the average of output data and the output data for successive scannings of the image speckles at the sensor plane is calculated to give the value of normalized blur (NB), which is a quantitative index of tissue blood flow velocity. In pigmented rabbit eyes, the coefficient of reproducibility was 8% when the same area of retina was measured twice at 5-minute intervals and 13% at 24-hour intervals. The NB values in the retina free of visible vessels were recorded under various levels of intraocular pressure ranging from 10 to 80 mmHg and the results were compared with the blood flow rate determined with the colored microsphere technique. A linear correlation was found between the former and the latter, which suggested that the NB value also parallels the tissue blood flow rate.

Animals↗
PubMed1994

[Prediction of prognosis of patients with gastrointestinal cancer based on thymidine uptake].

In 173 patients with operable gastric cancer and in 127 patients with colorectal cancer, the relations between thymidine uptake by cancer cells in semi-solid media, their clinico-pathologic features and survival times, were studied. Multivariate analysis using Cox proportional hazard model showed that thymidine uptake is one of the variables most highly correlated with the probability of patient death. Thus, the availability of thymidine uptake information in the perioperative period may be useful for selecting patients who would benefit from more intensive therapy. Thymidine kinase (TK) is the only enzyme by which thymidine is introduced into the DNA metabolism. In 64 specimens, including gastric and colorectal cancers, TK levels in the serum and tumors were measured accordingly. However, there was no correlation between thymidine uptake and the TK levels, suggesting the necessity of measuring thymidine phosphorylase activity as well.

Aged↗
PubMed1994

[Effect of calcium antagonist on retinal microcirculation evaluated with the laser speckle retinal microcirculation analyzer].

The effect of intravenous administration of a calcium antagonist on the retinal microcirculation in rabbit eyes was examined with a laser speckle retinal microcirculation analyzer. Under general anesthesia, 40 micrograms/kg of nicardipine, a calcium antagonist, was injected intravenously in the nicardipine group, and 0.4 ml/kg of saline in the control group. A quantitative index of blood flow velocity, the normalized blur (NB) value, in a retinal area (0. 62 x 0.62 mm) free of visible vessels, was recorded at 1-minute intervals for the first 5 minutes and at 5 minute-intervals for the next 85 minutes. The retinal NB value in the nicardipine group was significantly greater than in the control group, averaging 119%, 115%, 111%, 112%, and 116% of the initial value at 65, 75, 80, 85, and 90 minutes after injection, respectively. The blood pressure in the nicardipine group decreased significantly from 1 to 20 minutes after injection. The pulse rate, arterial pH, partial CO2 pressure, partial oxygen pressure, body temperature and intraocular pressure did not show significant change during the experiment. These results suggest, for the first time, that nicardipine increases the blood flow velocity in the retinal microvasculature in the living eye.

Animals↗
PubMed1994

[A case of multiple myeloma associated with a large subcutaneous mass in the frontal region].

A case of multiple myeloma having plasmacytoma in the frontal bone and clivus is reported. A 68-year-old female was referred to our hospital because of a subcutaneous mass in the frontal region. She was diagnosed as having multiple myeloma 7 years ago and had been treated with chemotherapy. On admission, severe anemia, hyperproteinemia and elevation of serum lambda type immunoglobulin G (IgG) were pointed out. Plain skull X-rays showed numerous punched out lesions with a large bone defect of the frontal bone. CT scan and MRI revealed a mass lesion in the clivus in addition to a large epidural tumor in the frontal region. The encapsulated frontal epidural tumor was totally resected and cranioplasty was performed with resin. Histological diagnosis was plasmacytoma of IgG lambda type. The postoperative course was uneventful, and chemotherapy was continued. There was no tumor recurrence in the frontal region and no neurological deterioration, but she died of DIC 15 months after the operation. Twenty seven cases in the literature of multiple myeloma forming cranial or intracranial plasmacytoma were briefly reviewed. Although the prognosis of such cases is poor, total resection of medullary plasmacytoma is warranted especially in multiple myeloma patients who don't have another extramedullary plasmacytoma or plasma cell leukemia.

Aged↗
PubMed1994

Analysis of mutations and expression of GAP-related domain of the neurofibromatosis type 1 (NF1) gene in the progression of chronic myelogenous leukemia.

We investigated mutations in the GTPase activating protein-related domain of the neurofibromatosis type 1 gene (NF1-GRD) and its expression in each phase of chronic myelogenous leukemia (CML). Samples from 45 cases in chronic phase (CP), 41 in acute phase, and four CML cell lines were examined for mutations in the NF1-GRD by single-strand conformation polymorphism (SSCP) analysis and allele specific restriction analysis (ASRA). No mutations were detected in the exon where frequent mutations have recently been reported in human tumors, namely the FLR exon. We also examined for point mutations of the N-ras gene but found no mutations either. In 23 samples from CML cases and four CML cell lines, expression of two types of the NF1-GRD transcripts, type I and type II, were examined by NF1-GRD-specific polymerase chain reaction-based densitometric analysis and by the quantitative assay with coamplification of the NF1-GRD and beta-actin transcripts. Consequently, although expression level of type I transcripts varied among the samples, type II expression was increased in CML cell lines and a minor increase in type II expression was observed in the samples in acute phase compared with CP. However, this difference in type II expression between CP and acute phase was so small that changes of NF1-GRD transcripts as well as NF1-GRD or N-ras mutations might not be responsible for the progression of CML.

Alleles↗
PubMed1993

G6PD Nara: a new class 1 glucose-6-phosphate dehydrogenase variant with an eight amino acid deletion.

In the course of molecular studies on Japanese glucose-6-phosphate dehydrogenase (G6PD) variants using single-strand conformation polymorphisms (SSCP) analysis, we found an unusual class 1 G6PD variant that had nucleotide deletion in exon 9. The patient showed chronic nonspherocytic hemolytic anemia associated with frequent episodes of severe hemolytic attack. The hemolysate exhibited no measurable activity. Although the partially purified enzyme had detectable activity, we could not perform kinetic studies because of its extreme instability. Nucleotide sequencing showed a unique 24 bp deletion at nucleotide 953-976 that predicts an eight amino acid deletion of TKGYLDDP at residue 319-326. While this is one of the most drastic structural alterations found in G6PD variants, the region with the amino acid deletion was distant from both the G6P and NADP+ binding sites and was located in a domain with low sequence homology among species. The comparatively low functional importance of the deleted region may have saved the patient from lethal tissue dysfunction.

Amino Acid Sequence↗
PubMed1993

Thymidine uptake in vitro as a prognostic indicator for primary gastric cancer.

BACKGROUND: Prognostic significance of in vitro thymidine uptake by cancer cells remains unclear in patients with gastric cancer. METHODS: In 173 patients with operable gastric cancer, the relations between thymidine uptake by gastric cancer cells in semi-solid media and their clinicopathologic features as well as their survival lengths were studied. RESULTS: There were significant correlations between in vitro thymidine uptake and such clinicopathologic features as lymph node metastasis (P = 0.00002), lymphatic invasion (P = 0.003), vessel invasion (P = 0.006), peritoneal metastasis (P = 0.010), depth of invasion (P = 0.011), and hepatic metastasis (P = 0.032). Ninety-five of 173 cancers (54.9%) that incorporated 1000 or more cpm in a single well were designated as being a high uptake group. Other gastric cancers (78 of 173; 45.1%) were designated as being a low uptake group. The overall survival rate of the patients was demonstrated to be significantly longer in the group with a low thymidine uptake than with a high uptake (P < 0.00001). The multivariate analysis showed that thymidine is one of the two variables that are the most highly correlated with the probability of patient death (P = 0.00044). CONCLUSIONS: These results indicated that in vitro thymidine uptake is an independent prognostic parameter for gastric cancer and may be useful for selecting patients who would benefit from more intensive therapy.

Aged↗
PubMed1993

Magnetic resonance imaging study of experimental acute spinal cord injury.

Magnetic resonance imaging (MRI) has been used widely in the diagnosis of acute spinal cord injuries. The association between MRI findings and histologic changes, however, remains unclear. Using a rabbit spinal cord injury model, the authors compared the MRI and histologic abnormalities as they evolved over the first post-trauma month. Bleeding in the gray matter, visualized as a low-intensity area on T1-weighted views and high-intensity area on T2-weighted views, observed immediately after injury, disappeared within the first week. Edema, appearing 6 hours after the initial injury and seen as a high-intensity T2-weighted MRI image, became maximal 1 week later and gradually decreased thereafter. Also appearing 1 week later, were necrotic changes in the gray matter, corresponding to low signals on T1-weighted studies but high signals on T2-weighted studies. MRI therefore helped differentiate hemorrhage and necrosis, presumably irreversible lesions, from the more reversible findings related to edema.

Animals↗
PubMed1993

Branched-chain 2-oxo acid dehydrogenase complex activation by tetanic contractions in rat skeletal muscle.

Branched-chain 2-oxo acid dehydrogenase complex in rat skeletal muscle was activated by muscle contractions elicited by electrical stimulation. This activation was attributed to dephosphorylation of the phosphorylated enzyme complex, and the total enzyme activity was not altered by muscle contractions. The activation of the enzyme complex occurred in the muscle of the electrically stimulated leg, but not in the muscle of the non-stimulated (control) leg, indicating that blood components are not involved in the mechanism of the enzyme activation in the muscle. Adenine nucleotides, branched-chain amino and 2-oxo acids and lactate in the muscle were determined as possible factors modulating the enzyme complex activity through inhibition of branched-chain 2-oxo acid dehydrogenase kinase activity. The profile of enzyme activation induced by muscle contractions was different from the alteration of the adenine nucleotide concentrations but was similar to the alteration of the concentrations of branched-chain amino and 2-oxo acids in the muscle. The lactate concentration in the stimulated muscle was elevated 3-5-fold during the contractions, indicating intracellular acidification. Previous studies have shown that the 2-oxo acid derived from leucine is a potent inhibitor of the kinase. These results suggest that intracellular branched-chain 2-oxo acids increased by muscle contractions accumulate in the mitochondria due to exercise-induced acidification of the muscle cell, resulting in activation of branched-chain 2-oxo acid dehydrogenase complex by inhibition of the kinase.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1993

Low substrate affinity of pyruvate kinase variant (PK Sapporo) caused by a single amino acid substitution (426 Arg-->Gln) associated with hereditary hemolytic anemia.

A point mutation (1277 CGG to CAG) was identified in the R-type pyruvate kinase (PK) cDNA of a PK variant, PK Sapporo, associated with hereditary non-spherocytic hemolytic anemia. The mutation causes a single amino acid substitution from Arg to Gln at the 426th amino acid residue of human R-type PK; consequently, the hydrophobicity around the mutated site is drastically decreased. The amino acid change occurred in the eighth alpha helix of A domain (A alpha 8) of PK, and it has been proposed that this region as well as A alpha 7, A beta 7, and A beta 8 is a potassium (K+) binding site. Because K+ binding to the PK subunit is considered to be essential for substrate binding, the mutation might account for the decreased affinity for phosphoenolpyruvate (PEP). This is compatible with the fact that all the reported PK variants carrying point mutations in those area have a high Michaelis constant (Km) for PEP.

Amino Acid Sequence↗
PubMed1993

Role of aminopeptidase N (CD13) in tumor-cell invasion and extracellular matrix degradation.

We have investigated the effect of monoclonal antibodies (MAbs) specific for aminopeptidase N/CD13 on the invasion of human metastatic tumor cells into reconstituted basement membrane (Matrigel). The invasion of human metastatic tumor cells (SN12M renal-cell carcinoma, HT1080 fibrosarcoma and A375M melanoma) into Matrigel-coated filters was inhibited by an anti-CD13 MAb, WM15, in a concentration-dependent manner. However, this MAb did not have any effect on tumor-cell adhesion and migration to the extracellular matrices, which may be involved in tumor-cell invasion. MAb WM15 inhibited the degradation of type-IV collagen by tumor cells in a concentration-dependent manner. We also found that WM15 inhibited hydrolysing activities towards substrates of aminopeptidases in 3 different tumor cells. Since our previous study indicated that bestatin, an aminopeptidase inhibitor, was able to inhibit tumor-cell invasion, as well as aminopeptidase activities of murine and human metastatic tumor cells, cell-surface amino-peptidase N/CD13 may be partly involved in the activation mechanism for type-IV collagenolysis to achieve tumor-cell invasion, and anti-CD13 MAb WM15 may inhibit tumor-cell invasion through a mechanism involving its inhibitory action on the aminopeptidase N in tumor cells.

Aminopeptidases↗
PubMed1993

Molecular basis of impaired pyruvate kinase isozyme conversion in erythroid cells: a single amino acid substitution near the active site and decreased mRNA content of the R-type PK.

Conversion of pyruvate kinase (PK) isozymes from M2- to R-PK has been observed during erythroid cell maturation. To understand this mechanism, we analyzed the PK gene of a R-PK deficient patient, in whose erythrocytes the M2-PK was persistently expressed. A point mutation, 1102 GTC-->TTC was identified in the R-PK cDNA, and it caused a single amino acid substitution from 368Val-->Phe. The residue is very close to the 372nd Gln, the putative binding site of the monovalent cation (K+). The impaired K+ binding would cause the decreased affinity for phosphoenolpyruvate, consequently the variant PK may be extremely unstable. Although the proband's other PK allele did not have any structural change, the R-PK mRNA level in reticulocytes was decreased. These findings suggested that both the structural mutation near the active site and the decreased mRNA level of the R-PK were responsible for the disorder.

Amino Acid Sequence↗
PubMed1993

Regulation of protein kinase C isoform proteins in phorbol ester-stimulated Jurkat T lymphoma cells.

Activation of protein kinase C (PKC) in T cells leads to a variety of responses including IL-2 production and IL-2 receptor expression. PKC consists of several isoforms that exhibit some different in vitro properties. We have set up a Western blotting system to explore the regulation of PKC isoforms during T cell activation. In Jurkat T lymphoma cells, PKC alpha, beta, delta, epsilon, and zeta were detected. PKC alpha and beta existed primarily in the cytosol, translocated to the membrane fraction after 10 minutes of treatment with PMA, and almost completely disappeared within 16 h. A larger fraction of PKC delta and epsilon existed in the membrane fraction compared to PKC alpha or beta, and PKC epsilon translocated to the membrane fraction rapidly. Translocation of PKC delta was not apparent after 1 h treatment with PMA, but total PKC delta protein was reduced within 4 to 6 h of treatment. Consistent with this, overnight treatment with PMA caused down-regulation of both PKC delta and epsilon, but to a lesser degree than was observed with PKC beta. Anti-PKC zeta antibody detected two bands at 82 and 75 kDa. The 75-kDa band existed mostly in the cytosol fraction and showed no translocation or down regulation after PMA. We present evidence that this 75-kDa band represents PKC zeta. Similar PMA-induced translocation responses were observed in murine thymocytes showing that the responses are not unique to PKC isoforms in Jurkat. These results demonstrate that it is possible for the PKC isoforms to be differentially regulated during T cell activation.

Animals↗