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Volume 193 (2001)
- Issue 4 Pages 259-
- Issue 3 Pages 163-
- Issue 2 Pages 79-
- Issue 1 Pages 1-
Volume 193, Issue 4
April
Displaying 1-6 of 6 articles from this issue
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Regular Contributions
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Hideyuki Honda, Taihei Naya, Yoshiro Koiwa2001 Volume 193 Issue 4 Pages 259-277
Published: 2001
Released on J-STAGE: February 01, 2005
JOURNAL FREE ACCESSWe examined whether the three states model can explain the systolic and relaxation properties of cardiac muscle to clarify what factors affect these properties. Changing the values of the parameters describing the calcium transient and calcium sensitivity, we estimated the effects of these parameters on the systolic and relaxation properties of twitch contraction. The simulations showed the following four features: 1) An increase in the maximum calcium concentration and calcium sensitivity, and a prolongation of the calcium transient led to an increase in peak tension associated with an increase in the time to peak tension. 2) An increase in myosin ATPase activity led to an increase in peak tension associated with a decrease in the time to peak tension. 3) An increase of peak tension was accompanied by a prolongation of the late systolic period. 4) The constant of the late tension relaxation from 25% to 10% of the peak tension was altered when the crossbridge cycling rate, the resting calcium concentration or the late decline of the calcium transient was changed. The simulation were not contradictory to the experimental results and showed that three state muscle model can provide qualitative descriptions on the systolic and relaxation characteristics of cardiac muscle.View full abstractDownload PDF (1017K) -
Satoru Takahashi, Keiko Ohsugi, Tokuo Yamamoto, Masashi Shiomi, Norio ...2001 Volume 193 Issue 4 Pages 279-292
Published: 2001
Released on J-STAGE: February 01, 2005
JOURNAL FREE ACCESSThis study has demonstrated the potential of human amniotic epithelial cells (HAEC) as a transgene carrier to treat patients with familial hypercholesterolemia (FH). One approach to liver-directed gene therapy is represented by transplantation of autologous hepatocytes that have been genetically modified in vitro. However, the hepatocytes must be isolated from surgically resected tissue and it is difficult to expand the hepatocytes in culture. In contrast, the advantages for using HAEC are the higher availability and the nonimmunogenicity after allotransplantation. Our strategy involved isolating HAEC from an amnion, transducing a human low-density lipoprotein receptor (LDLR) gene into these cells with a recombinant adenovirus, and transplanting the genetically modified cells into the liver of an animal model of FH. Each animal, treated with the LDLR-transduced HAEC, exhibited a substantial decrease in serum cholesterol with an eventual return to pretreatment level. Moreover, the transplanted HAEC migrated out of the sinusoids into the hepatic parenchyma and expressed the LDLRs until at least 20 days after transplantation. However, the transplanted HAEC markedly decreased in number after 10 days post-transplant with an increase of inflammatory cells. The temporary nature of the metabolic improvement may be associated with xenograft rejection and transient function of the adenoviral vector.View full abstractDownload PDF (1156K) -
Mitsuo Matsumoto, Hideaki Matsuhashi, Mitsuru Nakazawa2001 Volume 193 Issue 4 Pages 293-299
Published: 2001
Released on J-STAGE: February 01, 2005
JOURNAL FREE ACCESSOn purpose of the present study was to evaluate platelet aggregation and fibrinolytic systems in patients with normal tension glaucoma (NTG) or primary open angle glaucome (POAG). For platelet aggregation, we photoelectrophotometrically investigated adenosine diphosphate (ADP) or collagen-induced platelet aggregation in consecutively selected patients with glaucoma (22 patients with NTG and 13 patients with POAG) and 42 glaucoma free control subjects with normal ocular findings. The aggregation patterns of the patients' platelets reacted abnormally to ADP 1 μM or collagen 0.5 μg/ml as evidenced by secondary aggregation were compared with those of control subjects. For blood coagulative and fibrinolytic systems, we measured prothrombin time, activated partial thromboplastin time, fibrinogen, thrombin-antithrombin III complex (TAT), α2 plasmin inhibitor-plasmin complex. Seventeen of 22 patients (77%) with NTG and 5 of 13 patients (38%) with POAG showed abnormal secondary aggregation. A significant difference was observed between the two groups. No control subjects showed abnormal secondary aggregation. In the fibrinolytic test, all the parameters examined showed within normal ranges, although the log10(TAT) value was higher in NTG than in POAG. Results of the present study suggested that increased platelet aggregation as defined by ADP or collagen induced abnormal secondary aggregation in vitro is frequently associated with glaucoma patients and this tendency is more apparent in NTG than that in POAG.View full abstractDownload PDF (467K) -
Shyuitsu Maeda, Mikio Yoshida, Hiroko Hirano, Saburo Horiuchi2001 Volume 193 Issue 4 Pages 301-310
Published: 2001
Released on J-STAGE: February 01, 2005
JOURNAL FREE ACCESSMechanical loads are constantly being applied to articular cartilage. However, comparatively few studies have investigated the effects of mechanical stress on the gene expression of chondrocytes. Hence, the objective of the present study was to clarify the effects of mechanical stress on cultured chondrocytes. Articular chondrocytes of rabbits were isolated and placed in minimun essential medium eagle α modification containing 10% fetal bovine serum. The chondrocytes were cultured in polylayer in polypropylene tubes. After 48 hours, centrifugal stress (2.7 MJ) was applied once every 24 hours for 28 consecutive days. The mRNA expression of insulin-like growth factor-I (IGF-I) and cartilage-specific genes (type II collagen and aggrecan) in chondrocytes, cell count, wet tissue mass and protein content were subsequently measured. The results showed that the mRNA expression of the IGF-I gene for the stress groups was significantly greater than that of the control group from days 3 to 5 of incubation, as was the mRNA expression of the type II collagen gene from days 7 to 14 of incubation. However, there were no significant differences in the mRNA expression of the aggrecan gene between the control and stress groups. The cell count for the stress groups was significantly higher from days 7 to 28 of incubation, and the wet tissue mass and protein content were significantly higher from days 14 to 28 of incubation. These findings suggest that one of the mechanisms by which mechanical stress increases the number of cultured chondrocytes and the volume of extracellular matrix is to increase IGF-I expression at the early stage of incubation.View full abstractDownload PDF (668K) -
Chika Iwasaka-Yagi, Mayumi Abe, Yasufumi Sato2001 Volume 193 Issue 4 Pages 311-318
Published: 2001
Released on J-STAGE: February 01, 2005
JOURNAL FREE ACCESSWe examined whether TGF-β affects the transactivation activity of Ets-1. TGF-β augmented ets-1 mRNA expression and Ets-1 protein synthesis in ECV304 cells to the level equivalent to bFGF. When the DNA binding activity of Ets-1 protein was examined, bFGF was found to enhance DNA-Ets complex formation, whereas TGF-β attenuated basal as well as bFGF-enhanced DNA-Ets complex formation. As a result, TGF-β attenuated the promoter activity driven by Ets-1. The DNA binding of Ets-1 protein was enhanced by the initial 4-hour bFGF treatment and the subsequent 8-hour cycloheximide treatment. When TGF-β replaced cycloheximide in the subsequent 8-hour treatment, TGF-β inhibited this bFGF-enhanced DNA-Ets complex formation. When TGF-β and cycloheximide were simultaneously added in the subsequent 8-hour treatment, the inhibitory effect of TGF-β on bFGF-enhanced DNA-Ets complex formation was completely abolished. These results suggest the possibility that TGF-β attenuates the transactivation activity of Ets-1 by inducing a protein that interferes with the binding of Ets-1 to the DNA binding site.View full abstractDownload PDF (771K) -
Sohtaro Mimasaka, Masaki Hashiyada, Masayuki Nata, Masato Funayama2001 Volume 193 Issue 4 Pages 319-324
Published: 2001
Released on J-STAGE: February 01, 2005
JOURNAL FREE ACCESSInterleukin-6 (IL-6) has been considered as an important mediator of inflammation. Clinically it is a well-known marker of the severity of injury following major trauma. In this study, the levels of IL-6 in body serum were applied to a traumatic death index. Of ninety victims 55 were men and 35 women, with a mean age of 53.4±19 (S.D.) years. The cases were classified as traumatic deaths (38 cases), non-traumatic deaths other than natural causes of deaths (36 cases), and deaths due to natural causes (16 cases). All samples were collected within 2 days after death. The mean values of IL-6 levels of the traumatic, non-traumatic and disease groups were 8608.97, 2205.65, and 3266.64 pg/ml, respectively. Some cases in non-traumatic and disease cases were beyond 10 000 pg/ml, however, the mean value of the traumatic group was statistically higher than that of the other two groups. Even though several cases had high levels of IL-6 in spite of instantaneous death, the results showed that IL-6 levels are helpful in the diagnosis of traumatic shock.View full abstractDownload PDF (354K)
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