Biomedical subjects

T Iwasaki

Publications and source records attributed to T Iwasaki.

At least 163 records · Page 9Linked to original sources

PubMed1999

Modulation of the remote heme site geometry of recombinant mouse neuronal nitric-oxide synthase by the N-terminal hook region.

The role of two essential residues at the N-terminal hook region of neuronal nitric-oxide synthase (nNOS) in nitric-oxide synthase activity was investigated. Full-length mouse nNOS proteins containing single-point mutations of Thr-315 and Asp-314 to alanine were produced in the Escherichia coli and baculovirus-insect cell expression systems. The molecular properties of the mutant proteins were analyzed in detail by biochemical, optical, and electron paramagnetic resonance spectroscopic techniques and compared with those of the wild-type enzyme. Replacement of Asp-314 by Ala altered the geometry around the heme site and the substrate-binding pocket of the heme domain and abrogated the ability of nNOS to form catalytically active dimers. Replacement of Thr-315 by Ala reduced the protein stability and altered the geometry around the heme site, especially in the absence of bound (6R)-5,6,7, 8-tetrahydro-L-biopterin cofactor. These results suggest that Asp-314 and Thr-315 both play critical structural roles in stabilizing the heme domain and subunit interactions in mouse nNOS.

Amino Acid Sequence↗

PubMed1999

Enhanced protection against a lethal influenza virus challenge by immunization with both hemagglutinin- and neuraminidase-expressing DNAs.

The ability of plasmid DNA encoding hemagglutinin (HA), neuraminidase (NA) or matrix protein (M1) from influenza virus A/PR/8/34 (PR8) (H1N1), and mixtures of these plasmid DNAs (HA + NA and HA + NA + M1) to protect against homologous or heterologous virus infection was examined in BALB/c mice. Each DNA was inoculated twice, 3 weeks apart, or four times, 2 weeks apart, at a dose of 1 microg of each component per mouse by particle-mediated DNA transfer to the epidermis (gene gun). Seven days after the last immunization, mice were challenged with a lethal homologous or heterologous virus and the ability of each DNA to protect the mice from influenza was evaluated by observing lung virus titers and survival rates. The administration of a plasmid DNA mixture of either (HA + NA) or (HA + NA + M1) provided almost complete protection against the PR8 virus challenge, and this protection was accompanied by high levels of specific antibody responses to the respective components. The degree of protection afforded in these groups is significantly higher than that in mice given either HA- or NA-expressing DNA alone, which provided only a partial protection against PR8 challenge or that in mice given M1-expressing DNA, which failed to provide any protection. In addition, both of the plasmid DNA mixtures (HA + NA) and (HA + NA + M1) showed a slight tendency to provide cross-protection against an A/Yamagata/120/86 (H1N1) virus challenge, and this was accompanied by a relatively high level of cross-reacting antibodies. Thus, there was no clear difference between the ability of the HA + NA and HA + NA + M1 plasmid DNA mixtures in providing protection against either a PR8 or heterologous virus challenge. These results suggest that in mice immunized by gene gun, a mixture of plasmid DNAs encoding HA and NA can provide the most effective protection against the virus challenge. The addition of the M -expressing plasmid DNA to this mixture does not enhance the degree of protection afforded.

Animals↗

PubMed1999

Pathogenicity of tick-borne encephalitis virus isolated in Hokkaido, Japan in mouse model.

The pathogenic characteristics of tick-borne encephalitis (TBE) virus strain (Oshima 5-10) isolated from a sentinel dog in Hokkaido, Japan, was compared by use of a mouse model with several inoculation routes to other strains of TBE virus (the Far Eastern subtype; Sofjin strain and the Western subtype; Hochosterwitz strain) and TBE complex virus (Langat virus; TP-21 strain). The degree of neuroinvasiveness of the strains in mice subcutaneously (s.c.) inoculated was Sofjin equaled Hochosterwitz which was greater than Oshima and TP-21, respectively. Neurovirulence, as determined after intracerebral inoculation was Sofjin > Oshima = Hochosterwitz > TP-21. Virus replication in the brains of mice s.c. or intracerebrally inoculated with Oshima strain was slower and of lower titer than that of Sofjin strain. Histopathological findings indicated that subarachnoid infiltration of mononuclear cells prior to necrosis of the cerebrum was characteristic in Oshima strain. These findings indicated that the Oshima strain possessed a pathogenic potential common to TBE viruses and is less virulent for mice as compared with the two other TBE strains examined.

Animals↗

PubMed1999

Identification of HLA-A24 epitope peptides of carcinoembryonic antigen which induce tumor-reactive cytotoxic T lymphocyte.

Carcinoembryonic antigen (CEA), which is expressed in several cancer types, is a potential target for specific immunotherapy. HLA-A24 is the most frequent allele among Japanese and is also frequently present in Asians and Caucasians. We tested CEA-encoded HLA-A24 binding peptides for their capacity to elicit anti-tumor cytotoxic T lymphocytes (CTL) in vitro. For this purpose, we used CD8+ T lymphocytes from peripheral blood mononuclear cells (PBMC) of a healthy donor and autologous peptide-pulsed dendritic cells as antigen-presenting cells. This approach enabled us to identify 2 peptides, QYSWFVNGTF and TYACFVSNL, which were capable of eliciting CTL lines that lysed tumor cells expressing HLA-A24 and CEA. The cytotoxicity to tumor cells by the CTL lines was antigen-specific since it was inhibited by peptide-pulsed cold target cells as well as by anti-class I major histocompatibility complex (MHC) and anti-CD3 monoclonal antibodies (MAbs). The antigen specificity of the 2 CTL lines was examined using several tumor cell lines of various origins and for their peptide-dose responses. The identification of these novel CEA epitopes for CTL offers the opportunity to design and develop epitope-based immunotherapeutic approaches for treating HLA-A24+ patients with tumors that express CEA.

Amino Acid Sequence↗

PubMed1999

Na(+)influx via Na(+)/H(+)exchange activates protein kinase C isozymes delta and epsilon in cultured neonatal rat cardiac myocytes.

Protein kinase C (PKC) is one of the important signaling molecules in the development of the cardiac hypertrophic response, and activation of Na(+)/H(+)exchange is caused by PKC in myocytes. In this study we examined the contribution of Na(+)/H(+)exchange in cardiac hypertrophy induced by the activation of PKC and its mechanism using cultured neonatal rat cardiac myocytes. Phenylephrine (PE), endothelin-1 (ET-1) and phorbol 12-myristate 13-acetate (PMA) increased cytoplasmic pH in myocytes, and this effect was strongly inhibited by treatment with HOE694, an inhibitor of Na(+)/H(+)exchange. These substances increased the [(3)H]phenylalanine incorporation, total protein content and beta -myosin heavy chain protein content in myocytes. These hypertrophic responses were also attenuated by HOE694. To clarify the role of Na(+)influx through activation of Na(+)/H(+)exchange in cardiac hypertrophy, we next examined the hypertrophic responses to veratridine and ouabain, which increase the intracellular Na(+)content. Veratridine and ouabain increased the [(3)H]phenylalanine incorporation. Staurosporine, a PKC inhibitor, completely abolished veratridine-induced hypertrophic response, but did not affect increment of intracellular Na(+)concentration by veratridine. PMA caused increases of alpha -, delta -and epsilon -PKC in the particulate fraction, but PE, ET-1 and veratridine affected only those of delta - and epsilon -PKC. HOE694 significantly inhibited only increases of delta - and epsilon -PKC caused by PE, ET-1 or PMA, but not those by veratridine. These results demonstrate that Na(+)influx via activation of Na(+)/H(+)exchange reactivates PKC in myocytes. delta - and epsilon -PKC appear to be involved in the signal mechanism of the hypertrophic response induced by Na(+)influx through Na(+)/H(+)exchange in myocytes.

Animals↗

PubMed1999

Identification of biosynthetic intermediates of the extracellular polysaccharide viilian in Lactococcus lactis subspecies cremoris SBT 0495.

Lactococcus lactis subspecies cremoris SBT 0495 produces the phosphopolysaccharide viilian, which consists of the repeating unit beta-D-glucosyl-(1-->4)-(alpha-L-rhamnosyl-(1-->2))-(alpha-D-galac tose-1- phosphoryl-(-->3)-beta-galactosyl-(1-->4)-beta-D-glucose. A lipid extract was prepared from cells in the late exponential phase of growth and was hydrolyzed by hydrochloric acid under mild conditions to split lipid-linked intermediates in the extract into lipid and sugar moieties. Both moieties were purified by chromatographic techniques and were characterized to identify intermediates of the viilian biosynthetic pathway. A polyisoprenoid isolated from the chloroform-soluble fraction of the hydrolyzed lipid extract was identified by mass spectrometry as undecaprenol. Saccharides isolated from the water-soluble fraction of the hydrolyzed lipid extract by anion-exchange chromatography, were characterized by glycosidic linkage analysis to discriminate sugar moieties of intermediates of viilian biosynthesis from compounds liberated from cell wall components. Some oligosaccharide analogues contain a glycerol residue, suggesting that these are fragments of glycosylglycerides and/or lipoteichoic acid. Three fragments were identified to be glucose, galactosyl-(1-->4)-glucose, and rhamnosyl-(1-->2)-galactosyl-(1-->4)-glucose, which are in agreement with the structure of the repeating unit of viilian. These saccharides most likely represent the first three steps of the sequential assembly of the repeating unit of the undecaprenol assembly.

Carbohydrates↗

PubMed1999

Severe aplastic anemia associated with human parvovirus B19 infection in a patient without underlying disease.

Human parvovirus B19 (B19 virus) infection is known to induce aplastic crisis in patients with hemolytic anemia. In healthy subjects, B19 infection may sometimes cause mild pancytopenia, but these changes are transient and recovery is spontaneous. We report the first case of aplastic anemia in a previously healthy boy without any underlying diseases, following asymptomatic infection with the B19 virus. Laboratory examination initially showed thrombocytopenia, mild leukopenia in the peripheral blood, and severe hypoplastic bone marrow. Since pancytopenia developed and worsened progressively, immunosuppressive therapy was given, resulting in a complete remission. Despite the lack of an infectious prodrome, serological and histological analysis revealed an underlying infection with the B19 virus. Thus, B19 virus infection must be considered one of the causes of aplastic anemia in patients without underlying hemolytic anemia and an apparent episode of the viral infection.

Adolescent↗

PubMed1999

Exacerbation of influenzavirus pneumonia by intranasal administration of surfactant in a mouse model.

Although surfactant-secreting type II alveolar cells have been shown to be damaged during influenzavirus pneumonia, little is known about the effects of surfactant replacement therapy. We have developed a mouse influenza model, in which viral infection can be localized to the upper respiratory tract or to both the upper and lower respiratory tract depending on the volume (rather than infectious dose) of intranasal inocula of influenzavirus. In this model, only mice infected with a large inocula die with massive infection in the lung. Using this model, we unexpectedly found that intranasal administration of surfactant dramatically exacerbated influenzavirus infection causing fatal disease even in mice inoculated with a small inocula. This exacerbation resulted from enhancement of intrabronchial and intraalveolar spread of virus, as confirmed by immunohistochemical detection of viral antigen in lungs. Assuming this experimental model in mice recapitulates naturally occurring disease in humans, extreme caution is warranted in surfactant-replacement treatment of influenzavirus pneumonia in humans.

Administration, Intranasal↗

PubMed1999

Studies on a chemically defined medium for in vitro culture of in vitro matured and fertilized porcine oocytes.

The present study evaluated the effects of various components in a chemically defined medium on the development of IVM/IVF porcine embryos. The investigated components included energy substrates (lactate, pyruvate or glucose, alone or in various combinations), amino acids (glutamine, glycine or alanine), PVP and HEPES buffer. The effects of each energy substrate were the same as the control. However, a mixture of lactate with either of the other energy substrates increased the development rate. Glutamine tended to decrease rate of the development more than other amino acids, and this inhibition was dose dependent. Both PVP and HEPES buffer did not affect development rate. However, more than 35 mM HEPES buffer induced fragmentation From the above results, a new culture medium was designed (supplemented with 0.276 mM glycine, 0.176 mM alanine, 15 mM HEPES buffer and 1% (wt/vol) PVP in BSA-free Whitten's medium with or without glucose). The new medium resulted in a higher embryo development rate (20.4 and 16.3%) than that obtained with the control medium (10.0%).

Animals↗

PubMed1999

FGF-9 is an autocrine/paracrine neurotrophic substance for spinal motoneurons.

Motoneurons need muscle-derived neurotrophic substances for their survival during the initial phase of their development, but after maturation they lose this requirement and can survive after axotomy. This suggests that some neurotrophic substances other than target-derived ones control the survival of motoneurons in adults. Because spinal motoneurons express fibroblast growth factor-9 (FGF-9) messenger RNA, we hypothesized that FGF-9 might be an autocrine or paracrine survival factor for motoneurons. FGF-9 promoted the survival of motoneurons and upregulated the choline acetyl-transferase (ChAT) activity in the dissociated cultures of ventral half of rat E13 spinal cord. Externally added FGF-9 was more effective in low density cultures, and polyclonal blocking antibody against FGF-9 significantly lowered the ChAT activity. Our results support an autocrine or paracrine role for FGF-9 in mediating the survival of spinal motoneurons. Non-target-derived neurotrophic substances for motoneurons including FGF-9 should be important in the pathogenesis of motor neuron disorders in the adults, especially amyotrophic lateral sclerosis.

Animals↗

PubMed1999

Increased function of the voltage-dependent calcium channels, without increase of Ca2+ release from the sarcoplasmic reticulum in the arterioles of spontaneous hypertensive rats.

It has been reported that the increased function of the voltage-dependent calcium channels (VDCC) in the artery is involved in the increase of peripheral resistance in hypertension, and that the sarcoplasmic reticulum (SR) in the artery plays an important role in preventing the development of hypertension via a buffering effect. However, no reports have described the role of VDCC and SR in resistance arterioles in the development or maintenance of hypertension. We investigated the function of VDCC and of SR in the cremaster arterioles of spontaneous hypertensive rats (SHR) and age-matched Wistar Kyoto rats (WKY). The changes in diameter and the intracellular calcium ion concentration ([Ca2+]i) in the microdissected arterioles, using fluorescent dyes, were measured with videomicroscopy. The KCl concentration-response curves were analyzed in 4- to 5- and 7- to 8-week-old SHR and WKY. The changes in the vascular diameter and [Ca2+]i in response to ryanodine, an alpha-1 adrenoceptor, and angiotensin-II stimulation were compared between the 7- to 8-week-old SHR and WKY. We found an increase in the Ca2+ influx by VDCC in the early hypertensive stage, but not in prehypertensive SHR. However, after the onset of hypertension, there were no significant differences from WKY in the SR function mediated by Ca2+-induced Ca2+ release or inositol 1,4,5-trisphosphate-induced Ca2+ release. In conclusion, an increased influx of Ca2+ in the cell membrane, without a buffering effect of SR, was associated with progression of hypertension in the cremaster arterioles of SHR.

Animals↗

PubMed1999

Endothelin generating pathway through endothelin1-31 in human cultured bronchial smooth muscle cells.

The effects of endothelin (ET)-1(1-31) and ET-2(1-31), human chymase products of the corresponding big ETs, on the intracellular free Ca2+ concentration ([Ca2+]i) and [125I]-ET-1 binding were investigated using human cultured bronchial smooth muscle cells (BSMC). ET-1(1-31) (10(-8)M - 3 x 10(-7)M) and ET-2(1-31) (3 x 10(-8)M - 3 x 10(-6) M) caused an increase in [Ca2+]i in a concentration-dependent manner. Big ET-1 (3 x 10(-8)M - 10(-6)M) also caused this increase, but not big ET-2 at concentrations up to 10(-6)M. The [Ca2+]i increase induced by ET-1 was inhibited by both BQ123, an ET(A)-receptor antagonist, and BQ788, an ET(B)-receptor antagonist, whereas that induced by ET-3 was inhibited by BQ788 but not by BQ123. Increases in [Ca2+]i caused by ET-1(1-31), big ET-1 and ET-2(1-31) were completely inhibited by 10(-4)M phosphoramidon, a dual neutral endopeptidase (NEP)/endothelin-converting enzyme (ECE) inhibitor, and 10(-5)M thiorphan, a NEP inhibitor. Scatchard plot analyses of the saturation curves of [125I]-ET-1 and [125I]-ET-3 showed that both ET(A)- and ET(B)- receptors at the ratio of 4:1 were expressed on BSMC. ET-1(1-31), big ET-1 and ET-2(1-31) inhibited [125I]-ET-1 binding in a concentration-dependent manner, and these effects were attenuated by treatment with thiorphan. On the other hand, big ET-2 slightly inhibited the binding at a high concentration and this was not affected by thiorphan. These results suggest that ET-1(1-31), big ET-1 and ET-2(1-31) cause an increase in [Ca2+]i by being converted into the corresponding ET-1 and ET-2 by NEP, but this did not occur with big ET-2 in human BSMC. ET-2(1-31), produced by human chymase from big ET-2 might be important for the generation of ET-2 in human bronchial tissue.

Adult↗

PubMed1999

Stimulation of haematogenous liver metastases by ischaemia-reperfusion in rats.

OBJECTIVE: To find out whether hepatic ischaemia-reperfusion stimulates hepatic tumour metastases using a cell line of rat ascitic hepatoma (AH130). DESIGN: Prospective experimental study. SETTING: University laboratories, Japan. MATERIALS: 118 male Donryu rats. INTERVENTION: After laparotomy alone (group 1, n = 35) or laparotomy and 20-minutes ischaemia (group 2, n = 34) or laparotomy and 30-minutes ischaemia (group 3, n = 34) of the median and left hepatic lobes, the animals were given either an intraportal injection of 1 x 10(5) or an intravenous injection of 1 x 10(6) viable AH130 cells. MAIN OUTCOME MEASURES: 10 days after inoculation of tumour cells the number of nodules on the surface of the right lobe and of the median plus left lobes were separately counted for each liver. RESULTS: Irrespective of the route of tumour inoculation in group 1, there was no significant difference in the number of tumours/g liver between the right and the median plus left lobes. However, in groups 2 and 3, the number of tumours/g liver in the median plus left lobes was significantly higher than in the right lobe (p < 0.05). Furthermore, in the median plus left lobes, animals who had had 30 minutes of ischaemia had significantly more tumours than those in the other two groups (p < 0.01). CONCLUSION: Hepatic ischaemia-reperfusion may increase the risk of development of haematogenous liver metastases, by stimulating tumour cell-endothelial cell interactions.

Analysis of Variance↗

PubMed1999

Inhibition of neuronal nitric oxide synthase by phosphatidylinositol 4,5-bisphosphate and phosphatidic acid.

Phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidic acid (PA) were found to inhibit strongly the citrulline formation activity of neuronal nitric oxide synthase (nNOS; EC 1.14.13.39). Such inhibition was not observed with any other phospholipid examined. A kinetic analysis of purified nNOS showed no significant change in apparent K(m) for L-Arg or NADPH caused by these inhibitory phospholipids. Electron paramagnetic resonance analysis revealed no significant spectral perturbation of the ferriheme or flavin semiquinone upon the addition of PIP2. On the other hand, a lower enhancement of the NADPH diaphorase activity by Ca(2+)-calmodulin was observed in the presence of PIP2 and PA, and the citrulline formation activity was protected from phospholipid inhibition by preincubation with Ca(2+)-calmodulin. Moreover, trypsin digestion analysis showed that the cleavage site within the calmodulin-binding site of nNOS was specifically protected from trypsin by the addition of PIP2 and PA. These results strongly suggest that PIP2 and PA inhibit the citrulline formation activity of nNOS by blocking the interaction of the enzyme with Ca(2+)-calmodulin.

Amino Acid Sequence↗

PubMed1999

Analysis of circadian blood pressure rhythm and target-organ damage in stroke-prone spontaneously hypertensive rats.

OBJECTIVE: We compared diurnal patterns of blood pressure in Wistar-Kyoto (WKY) rats, spontaneously hypertensive rats (SHR) and stroke-prone spontaneously hypertensive rats (SHRSP), and analyzed the relationship between the change in diurnal patterns of blood pressure and target-organ damage in SHRSP. MATERIALS AND METHODS: Blood pressure, heart rate and motor activity in the three groups of rats were continuously monitored by radiotelemetry, from 1100 h on the first measuring day to 1300 h on the third measuring day. The left ventricular weight and the ratio of beta-myosin heavy chain to alpha-myosin heavy chain in the cardiac left ventricle, morphological changes in the glomerular basement membrane in the kidney, 24 h urinary protein excretion and brain weights were also measured in 10-, 12- or 17-week-old SHRSP. RESULTS: The SHR circadian blood pressure rhythm exhibited a pattern which peaked during the rats' active (light-off or dark) phase, but the peak time was a little closer to the resting (light-on) phase compared with that for WKY rats. Although the circadian blood pressure rhythm for 10-week-old SHRSP was similar to that observed for SHR, the patterns in 12- and 17-week-old SHRSP were shifted further towards the resting phase. Heart and left ventricular weight increased with the progression of hypertension. The ratio of beta- to alpha-myosin heavy chain in the left ventricle was higher in 12- and 17-week-old SHRSP than in 10-week-old SHRSP. Brain weight was increased significantly in 17-week-old SHRSP compared with 10- and 12-week-old SHRSP. Increased urinary protein excretion and morphological changes in the glomerular basement membrane in the kidney were observed in 12- and 17-week-old SHRSP. CONCLUSIONS: These data suggest that SHRSP have an abnormal circadian blood pressure rhythm associated with hypertensive target-organ damage. This rat strain may therefore be a useful model in which to investigate the mechanisms responsible for the alteration in the circadian blood pressure rhythm, and to analyze the relationship between the abnormal circadian rhythm and target-organ damage.

Animals↗

PubMed1999

Pharmacological characterization of PABSA, an orally active and highly potent endothelin-receptor antagonist.

The pharmacological characterization of a nonpeptide endothelin (ET)-receptor antagonist, PABSA [(R)-(--)-2-(benzo[1,3]dioxol-5-yl)-N-(4-isopropyl-phenylsulfon yl)-2-(6-methyl-2-propylpyridin-3-yloxy)-acetamide hydrochloride] was studied. PABSA competitively inhibited the binding of [125I]-ET-1 to A7r5 cells expressing ET(A) receptors and of [125I]-ET-3 to COS cells expressing porcine ET(B) receptors with Ki values of 0.11 and 25 nM, respectively. PABSA inhibited ET(A) receptor-mediated and ET(B) receptor-mediated vasocontraction and ET(B) receptor-mediated vasorelaxation in isolated rabbit vessels with K(b) values of 0.46, 94, and 26 nM, respectively. The antagonist potency of PABSA for ET(A) receptor-mediated vasocontraction was 63- and 87-fold more potent than those of BQ-123 and bosentan, respectively, and was similar to those of TAK-044 and SB209670. Oral administration of PABSA (1-10 mg/kg) caused dose-dependent inhibition of the pressor response to exogenous ET- 1 (0.1 nmol/kg) in conscious normotensive rats. PABSA (10-100 mg/kg, p.o.) reduced blood pressure in deoxycorticosterone acetate (DOCA)-salt hypertensive rats, spontaneously hypertensive rats (SHRs), and stroke-prone spontaneously hypertensive rats (SHRSPs). The hypotensive effect of PABSA was sustained for > or =24 h in these rats. These results suggest that PABSA is a highly potent ET(A)-receptor antagonist with weak ET(B)-receptor antagonist activity. Because PABSA has a long duration of action in vivo, this antagonist should be useful in the therapy of ET-related disease.

Administration, Oral↗

PubMed1999

A simple, reliable method of assessing exercise capacity in patients with chronic heart failure.

OBJECTIVE: The accurate determination of limitations in physical activity is important in evaluating patients with heart failure and in assessing the efficacy of treatment. However, the conventional measures used to evaluate hemodynamics, functional class, and exercise capacity all have limitations. Our objective was to develop a simple method (The Master-Borg test) for evaluating the physical activity of patients with chronic heart failure using self-evaluation of the sensation of dyspnea at a constant workload. METHODS: Patients with NYHA class I (N = 20), class II (N = 20), and class III (N = 20) chronic heart failure performed a symptom-limited treadmill exercise test to determine peak VO2 and anaerobic threshold (AT). Patients subsequently performed Master's two-step test for 90 s and maximal dyspnea was self-rated using the visual analog Borg scale (the Master-Borg test). RESULTS: The mean workload in the Master-Borg test was 15.2+/-1.6 mL x min(-1) x kg(-1). A significant correlation was found between the Master-Borg score and peak VO2 (r = 0.87) or AT (r = 0.84). The reproducibility of the Master-Borg tests was represented by a correlation coefficient of 0.93. CONCLUSION: Although simple and inexpensive, the Master-Borg test accurately represents ordinary activity levels, relates the sensation of dyspnea to peak exercise tolerance, and can be completed by most patients with heart failure. Master-Borg scores correlated with peak VO2 and AT, and can differentiate among NYHA classes I, II, and III. The Master-Borg test appears to be clinically useful for evaluating the value of physical activity and exercise capacity of patients with chronic heart failure.

Aged↗

PubMed1999

Co-expression of Bcl-2 protein and vascular endothelial growth factor in hepatocellular carcinomas treated by chemoembolization.

AIMS/BACKGROUND: Transcatheter arterial chemoembolization (TAE) of hepatocellular carcinoma (HCC) causes anoxia. Escape of cancer cells from anoxic injury may be enhanced by induction of proteins which provide resistance to apoptosis. METHODS: We examined HCCs immunohistochemically for Bcl-2, vascular endothelial growth factor (VEGF), p53, and Ki67. The staining intensity for VEGF, a protein induced by anoxia, was assessed morphometrically with a computer-assisted image-analyzer. RESULTS: The frequency of Bcl-2 positive cells was higher in HCCs that had undergone TAE (TAE HCC) than that in HCCs that had not undergone TAE (41.75+/-15.06 vs. 1.01+/-0.79 cells/1000 cells, p = 0.0173). The frequency of p53- or Ki67-positive cells was not increased after TAE. Of 12 TAE HCCs, 7 had Bcl-2 positive HCC cells and 6 had clusters of Bcl-2 positive cells. In contrast, 2 of 11 HCCs that had not undergone TAE had only a few, sporadically distributed, Bcl-2-positive cells. The staining intensity for VEGF was higher in Bcl-2 positive than in Bcl-2 negative areas (1.208+/-0.091 vs. 1.071+/-0.017, p = 0.0222). Furthermore, the VEGF staining intensity in Bcl-2 positive areas of TAE HCCs was higher than in Bcl-2 negative areas (1.296+/-0.126 vs. 1.066+/-0.024, p = 0.0186), while in HCCs that had not undergone TAE the staining intensity was similar. CONCLUSIONS: TAE of HCC can induce Bcl-2 expression, possibly through anoxic stress.

Carcinoma, Hepatocellular↗