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N Fujitani

Publications and source records attributed to N Fujitani.

36 records · Page 2Linked to original sources
PubMed1996

Morphological and morphometric investigation of cardiac lesions after chronic administration of methamphetamine in rats.

The effects of chronic administration of methamphetamine on myocardium were morphologically and morphometrically studied in experimental models. Methamphetamine (1 mg/kg/day) was subcutaneously injected to five-week-old male Wistar Kyoto rats (WKY) for 8 weeks. Age- and sex-matched WKY served as controls. In light microscopy, scattered cytomyolysis, vacuolization, contraction bands and disarray of myofibers were prominent in methamphetamine-treated group; the electron microscopy showed degenerated mitochondria with disrupted cristae, myofibrillar hypercontraction and dissolution. Morphometric analysis was carried out using electron photographs and an image analyzer. The sizes of mitochondria and the number of mitochondria per unit area (100 microns2) in methamphetamine-treated group were significantly smaller than in the controls. No statistically significant difference was found regarding the percentage of myofibrillar area in cytoplasm between methamphetamine-treated and control groups. These findings show that chronic administration of methamphetamine can cause serious cardiac lesions and decrease in mitochondrial function.

Animals↗
PubMed1995

Pathological changes of myocardial cytoskeleton in cardiomyopathic hamster.

Immunocytochemical investigation was performed on the cytoskeletal proteins in cardiac tissue of the cardiomyopathic hamster. Male cardiomyopathic UM-X7.1 hamsters at 180 days of age (n = 8) and age- and sex-matched normal BIO-RB hamsters (n = 8) were used in this study. Immunofluorescence microscopy using monoclonal antibodies against desmin, alpha-actinin, titin, and vincullin was employed. The heart weight to body weight ratio was significantly increased in the heart of cardiomyopathic hamster compared with that of normal hamster. In cardiomyopathic hamster, the left ventricular cavity was markedly dilated. Light microscopically, hypertrophy and atrophy of myocytes and myocardial fibrosis were prominently observed in cardiomyopathic myocardium. Immunocytochemically, desmin, alpha-actinin and titin showed the cross striations along the myofibers in normal myocardium. In contrast, in cardiomyopathic myocardium, desmin was irregularly distributed in myocytes and the amount of desmin was increased. Loss of cross striations of alpha-actinin and titin were frequently observed. Immunofluorescence against vinculin was not significantly altered. We conclude that the alterations of cytoskeletal proteins in myocardial cells may relate to decreased myocardial function in cardiomyopathic hamster failing heart.

Actinin↗
PubMed1995

The mechanism of interaction of sodium dodecyl sulfate with elastic fibers.

Sodium dodecyl sulfate (SDS), an anionic hydrophobic ligand, is known to alter the mechanical properties of elastic fibers. In order to analyze the mechanism of the alteration, two forms of fibrous elastins, "solid" and "powder" elastins, which consisted of fascicular elastic fibers and single or oligomeric elastic fibers, respectively, were prepared from bovine aorta, and the interactions of SDS with these elastins in the presence and absence of 0.15 M NaCl were studied. The solid elastin was able to retain 1.2- to 1.4-fold larger amounts of SDS than the powder elastin under both conditions, and both elastins retained 1.2-fold or larger amounts of SDS in the presence of NaCl than in its absence. Whereas both elastins released the retained SDS gradually on repeated washing with an SDS-free buffer, the release rates from the solid elastin, especially the rate in the presence of NaCl, were much smaller than those from the powder elastin, and the solid elastin retained approximately 40% of the bound SDS under conditions where the powder elastin lost most of its SDS. The SDS-binding capacities of both elastins were significantly lower than those of soluble kappa-elastin and serum albumin, which bound SDS homogeneously on the polypeptide chains. When the washed SDS-bound solid elastin was incubated with methylene blue and examined under a microscope, most of the methylene blue-SDS complex was located at the interfiber spaces of the elastic fibers. These results suggest that SDS alters the mechanical properties of elastic fibers by binding to the interfiber spaces and surfaces of the fibers rather than by binding to the internal polypeptide chains.

Animals↗
PubMed1995

Biochemical characterization of the fibres of collagen and elastin in the aortic wall of SHRSP.

1. Vessel wall fragments consisting of collagen, elastin and other insoluble proteins were prepared from the aortas of 6 month old WKY and SHRSP and dead, elderly humans. 2. Prolonged incubations of these fragments with pepsin below or at 30 degrees C resulted in different amounts of insoluble materials containing similar or larger proportions of collagen and other insoluble proteins than the respective vessel fragments. The amounts of the pepsin-insoluble materials obtained from SHRSP were larger than those from WKY but were much smaller than those from elderly humans. 3. The elastins isolated from the vessel fragments were solubilized by pepsin much more effectively than the respective vessel fragments. 4. The pepsin-insoluble materials from WKY were composed of thin mesh-shaped materials, while these materials from both rats did not contain a significant number of distinctive fibrils of collagen, the materials from elderly humans did contain numerous distinctive fibrils of collagen. 5. Large fractions of both the collagen and other proteins in the pepsin-insoluble materials were solubilized by incubation with a crude bacterial collagenase below 30 degrees C or by incubation with pepsin above 40 degrees C where the triple-helical regions of the collagens were unfolded. 6. These results appear to indicate that the aortic wall of SHRSP contains larger amounts of some insoluble components that immobilize the collagen fibrils than that of WKY, but the aortic walls of elderly humans contain much larger amounts of these components than that of SHRSP.

Aged↗
PubMed1995

Effects of various types of extracellular matrices on adhesion, proliferation, differentiation, and c-fos protein expression of porcine thyroid follicle cells.

Thyroid follicles in vivo are embedded in extracellular matrix (ECM). The composing epithelial cells are in close contact with ECM at the basal side. To examine cell-to-ECM interactions, we studied adhesion, proliferation and differentiation of porcine follicle cells monolayer-cultured on type I and IV collagen, fibronectin or laminin. At 3 h in culture, laminin had the lowest rate of cell adhesion. In proliferation, type IV collagen induced the highest level of nuclear bromodeoxyuridine intake. In a functional differentiation, laminin had about 3 times as much triiodothyronine production as the other ECM molecules. In confluent culture cells, we also examined an expression of c-fos protein, a transcription factor that plays crucial roles in signal transduction. Immunocytochemistry detected the protein mainly in the nuclei. Western blot showed that laminin induced the highest level of its expression. Thyrotropin (TSH, 10 mU/ml) did not affect adhesion of the cells on any of the substrata or proliferation of the cells on fibronectin; nor did TSH affect c-fos protein expression of the cells on the substrata except for fibronectin. Our results suggest that type IV collagen and laminin, major components of basement membrane, play positive roles in proliferation and differentiation of follicle cells, respectively, while laminin has no positive effect on adhesion of the cells at early culture; that the cells express c-fos protein even in contact inhibition of growth and its expression is regulated in part by ECM; and that ECM controls some behaviors of the cells in a TSH-dependent or TSH-independent manner.

Animals↗
PubMed1994

Altered expression of titin and contractile proteins in failing human myocardium.

Our own previous ultrastructural studies in human hearts with dilated cardiomyopathy and heart failure showed sarcomeric and cytoskeletal disarrangement. On the basis of these findings we tested the hypothesis that in cardiomyopathic failing hearts not only the sarcomere structure but also the organization and the amount of numerous contractile proteins are disturbed. Titin was included in this study because it is the elastic "third" filament of the sarcomere and also plays an important role as template for myosin and actin filaments in sarcomerogenesis. Human cardiac tissue obtained at the time of transplantation surgery was investigated using immunohistochemistry with monoclonal antibodies against titin, myosin, actin, tropomyosin, and troponin T. Additionally, isolated myocytes from rat or pig heart were used for the standardization of the localization pattern. In normal tissue, myosin and the thin filament complex showed a regular cross striation that was wider in myosin staining than for actin, troponin T, and tropomyosin corresponding with the different width of the A and I bands in the sarcomere. Titin localization in normal human and animal myocardium showed a regular cross striation pattern. In diseased cardiac tissue titin fluorescence intensity was reduced and frequently disorganization or almost complete loss of titin from many myocytes were present. Severe abnormalities of contractile proteins consisting of disarrangement or lack of filaments were also observed. Double staining procedures showed that in the same myocyte defects of the contractile apparatus were accompanied by a simultaneous reduction of titin indicating that the "third" sarcomeric filament system is involved in heart failure. Abnormalities of titin expression may be especially important because titin significantly influences sarcomeric elastic behaviour and is necessary as template for the organization of newly synthesized myosin and actin filaments. The loss of titin may contribute to the altered compliance in failing hearts. It is concluded that disorganization and loss of titin, myosin, and the thin filament complex are severe in the failing human heart because of dilated cardiomyopathy and that these changes may represent several of the most important components of the structural correlate of reduced cardiac function.

Adult↗
PubMed1992

Comparative studies on the extractability of collagen from aortas of stroke-prone spontaneously hypertensive and normotensive rats.

The molecular states of collagen in the aortas of age-matched stroke-prone spontaneously hypertensive (SHRSP) and normotensive Wistar Kyoto rats (WKY) were studied by analyzing its extractability under defined conditions. The monomeric and oligomeric collagen extractable with 0.5 M acetic acid/6 M urea from aortic homogenates of 9-month-old SHRSP and WKY comprised approx. 0.6 and 2.0%, respectively, of the total collagen. On incubation of the acetic acid/urea-extracted residues with pepsin at 4 degrees C, the levels of the collagen alpha 1(I) and alpha 2(I) chains solubilized from the SHRSP residues were both less than 50% of those from the WKY residues. When the residues were incubated with pepsin at 15 or 25 degrees C, the differences became smaller. When the acetic acid/urea residues were hydrolyzed with cyanogen bromide, nearly identical peptide maps were obtained for SHRSP and WKY. The aortas from 2-month-old SHRSP and WKY contained much larger proportions of acid/urea-extractable collagen than those of the older rats (8.2 and 13% of the respective total collagen). The levels of the alpha 1(I) and alpha 2(I) chains solubilizable from the respective residues by pepsin at 4 degrees C were similar to each other. These results indicate that aortic collagen fibrils in SHRSP are stiffened more prominently than those in WKY.

Aging↗
PubMed1991

Tissue-specific and non-tissue-specific heavy-chain isoforms of myosin in the brain as revealed by monoclonal antibodies.

Four types of monoclonal antibody (BM-1, BM-2, BM-3 and BM-4) each having distinctive tissue specificity were obtained by immunizing mice with purified bovine cerebrum myosin. Both BM-1 and BM-2 reacted most efficiently with cerebrum myosin and less efficiently with myosins from other limited nonmuscle tissues, the tissue specificity of BM-1 being much narrower than that of BM-2. BM-3 reacted more efficiently with several other nonmuscle myosins than with cerebellar or cerebral myosin. BM-4 recognized various nonmuscle and smooth muscle myosins with a nearly equal efficiency. Cerebral myosin as well a cerebellar myosin contained two or more electrophoretic variants of the heavy chains. BM-1 and BM-3 as well as BM-2 and BM-3 were found to recognize selectively these distinct heavy-chain isoforms. The antigenic sites of the three tissue-specific antibodies (BM-1, BM-2 and BM-3) were all localized near the head/tail junction of the myosin molecules, while that of non-tissue-specific antibody BM-4 was near the center of the tail. These and additional results indicate that mammalian brain tissues as well as several other nonmuscle tissues contain multiple heavy-chain isoforms of myosin, the levels of which differed considerably from one tissue to another.

Animals↗
PubMed1991

Vital reactions in rat skin wounds by quantitation of fibrin.

The fibrin contents in contused skin wounds that were experimentally inflicted on rats were measured by a new method which was based on the determination of solubilized fibrin degradation products (FDP) using a latex agglutination test after plasmin digestion of tissue homogenates. The levels of FDP in ante-mortem wounds began to increase within 10 min after wounding and continued to increase for up to 6 h. The FDP levels in post-mortem wounds remained under the detection limit of the method used and were identical to those of intact tissues. The fibrin contents in the ante-mortem wounds prepared 2 days after death did not differ significantly from those prepared immediately. The results suggest that this method may be applicable to the identification of the vital reaction of the wound.

Animals↗
PubMed1991

ABO grouping of highly-dilute blood by the absorption-elution technique using nitrocellulose beads--application to a casework investigation.

This paper reports a homicidal case in which the absorption-elution technique using nitrocellulose beads as immunoadsorbents was successfully applied to ABO grouping from highly-diluted blood. A 21-year-old man was found dead in bed while staying in a hotel. He had multiple wounds over the entire body. By autopsy the cause of death was decided to be traumatic shock. The victim's blood group was A. A bucket filled with faint-colored water was found at the scene. By means of the absorption-elution technique using nitrocellulose beads the water was grouped as B. Later, a 32-year-old man staying in the hotel together with the victim was suspected and arrested. The suspect's blood group was B. He confessed that he had injured himself in the hands with a knife during the struggle and washed them in the water.

ABO Blood-Group System↗
PubMed1989

An epidemiologic and histopathological study of sudden cardiac death in Osaka Medical Examiner's Office.

From 1982 to 1986, 1230 sudden death cases were autopsied in Osaka Medical Examiner's Office. Among them, 810 cases were sudden cardiac deaths (SCD) including coronary heart disease (77%), cardiomyopathy (7%), valvular disease (3%). All SCD cases were dead within 24 hours of the appearance of the fatal symptoms, and most of them (72%) were considered instantaneous death. Many of the fatal symptoms began in bed (31%), at bath (17%), at toilet (8%), or at work (8%). Thirty-four percent of them were thought by themselves or by their families to be healthy before the death. Hypertension (38%), coronary heart disease (13%) and diabetes mellitus (11%) were the major past history recorded. Microscopic observation of the hearts of 200 cases autopsied in 1986 showed various cardiac lesions: hypertrophy, atrophy, degenerations of myocytes, cellular and fatty infiltrations of the interstitium. According to their cardiac lesions and degrees of severity of coronary sclerosis, patients who died suddenly were divided into 8 groups as follows: 1. myocardial infarction (41) 2. myocarditis (6) 3. hypertrophic cardiomyopathy (19) 4. chronic ischemia with severe coronary sclerosis (65) 5. chronic ischemia with moderate coronary sclerosis (27) 6. small vessel disease (18) 7. amyloidosis (1) 8. unknown (23). These results suggest that coronary heart disease and hypertension play an important role in SCD.

Adolescent↗
PubMed1984

Novel methods for determining the vital reaction in injured skin.

The authors devised two new methods for determining the vital reaction of injured skin and tentatively termed them Method I and Method II. Method I is based on the determination of "fibrin-forming ability" of slices of injured skin in the presence of added fibrinogen. Method II is based on the measurement of the albumin content in the injured skin by rocket-immunoelectrophoresis. These methods have the following characteristics: Both are able to distinguish ante-mortem from post-mortem wounds, even in fresh vital wounds. The fibrin-forming ability in vital wounds undergoes a post-mortem change, and this can be used to distinguish ante-from post-mortem wounds for 2 days after death. On the other hand, the albumin content of wounds is virtually unchanged post-mortem until one week after death. Method II is therefore applicable even to slightly decomposed materials one week after death. It is not recommended that this method be used for the wound in the post-mortem hypostatic area. Regarding the technique, both methods are relatively easy. Both methods are able to estimate the wound age until about 2 days after injury (during wound healing). A more reliable estimate of wound age is possible by using Method I together with Method II.

Animals↗
PubMedDate not supplied

Effect of sulfhydryl group modification on age-associated alteration of actomyosin ATPase activity in human myocardium.

Cardiac ventricular actomyosin was prepared from autopsy samples from humans ranging in age from one to 83 years, and its Ca2(+)-ATPase and K(+)-EDTA-ATPase activities were determined in the presence or absence of a sulfhydryl reagent, N-ethylmaleimide (NEM). The Ca2(+)-ATPase activity increased in the presence of appropriate concentrations of NEM. The extent of the stimulation of Ca2(+)-ATPase activity by NEM decreased significantly with age. The ratio of K(+)-EDTA-ATPase activity to Ca2(+)-ATPase activity also decreased with age. This suggests that there is an age-related modification of sulfhydryl groups in the myosin molecule.

Adenosine Triphosphatases↗