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Biomedical subjects

T Katagiri

Publications and source records attributed to T Katagiri.

At least 325 records · Page 18Linked to original sources
PubMed1984

Regional changes in mitochondrial respiration in acute myocardial ischemia. Comparison of the inner and outer heart muscles.

Impairment of mitochondrial respiration in acute myocardial ischemia was studied in the inner and outer layers of canine heart muscle by the determination of oxidative phosphorylation and several respiratory enzymatic activities of isolated mitochondria. As early as 15 min after coronary ligation, the respiratory control ratio decreased as the result of a reduction in the oxygen consumption rate in state 3 to 72% of the control ratio in the inner layer. However, in the outer layer, it dropped to 74% after 1 to 2 hours. The oxygen consumption rate in state 4 and the ADP/O ratio were not significantly altered in both cardiac sublayers. In parallel with a decrease in oxygen consumption rate in state 3, Mg++-dependent ATPase and DNP-stimulated ATPase activities of isolated mitochondria reduced significantly in both sublayers, followed by a sequential increase in Mg++-dependent ATPase activity. Succinate dehydrogenase activity increased in ischemia for 3 hours in the inner layer, and for 6 hours in the outer layer, respectively; cytochrome oxidase activity reduced in both sublayers during the same period. Mitochondrial respiration is impaired in acute myocardial ischemia much earlier in the inner layer by a decrease in oxygen consumption rate in state 3, and there is a chronological delay in the development of ischemic mitochondrial changes in the outer myocardium.

Adenosine Triphosphatases↗
PubMed1984

Analysis of structural proteins from biopsied human myocardium with special emphasis on methodology.

An analytical procedure for the quantitative determination of the structural proteins from a biopsied human cardiac muscle weighing approximately 1 mg was described to be applicable in clinical studies in 20 patients with various heart diseases. The principle of the method is glycerinization of heart muscle and analysis by SDS gel electrophoresis. In 6 control heart muscles obtained from patients having almost normal hearts, the pattern of the structural proteins was similar to that of the normal canine heart. Myosin heavy chain-actin ratio ranged 1.26 +/- 0.44. In 5 cases with secondary cardiac hypertrophy, the pattern of the structural proteins was the same as that of the control heart. In 4 cases with hypertrophic cardiomyopathy, an increase in myosin heavy chain was observed in 2 cases, while myosin heavy chain and alpha-actinin decreased in another 2 cases. Hypertrophy and severe disarray of myofibrils were noted in the former, and atrophy and degradation were done in the latter in electron microscopy. In 5 cases with dilated cardiomyopathies, the relative contents of myosin heavy chain and alpha-actinin was reduced in all cases together with atrophy and degradation of myofibrils.

Actinin↗
PubMed1984

Aberrant expression of Forssman and Paul-Bunnell antigens on lymph node cells of MRL/Mp-lpr/lpr mice.

Lymph node cells (LNC) of MRL/Mp-lpr/lpr mice (MRL/1) and congeneic MRL/Mp-+/+ (MRL/n) mice were studied by means of flow fluorocytometry for the expression of heterophile Forssman (F) and Paul-Bunnell (P-B) antigens. The level of F antigen on LNC of MRL/1, but not on those of MRL/n mice, increased progressively with age and reached its maximum at 4 mo of age. No such increase in F antigen on LNC of age-matched C3H/HeJms, C57BL/6, and AKR mice was observed. In contrast, the level of P-B antigen on LNC of MRL/1 mice was significantly lower than that of MRL/n and the normal mice. F-positive LNC of MRL/1 mice were shown to be T cells with Thy-1.2 and Lyt-1 markers; those cells expanded in the lymph nodes and were responsible for the development of the massive lymphadenopathy. Studies on LNC of F1 hybrids between MRL/1 and MRL/n mice, and animals of the subsequent F2 generation provided evidence that the aberrant expression of F and P-B antigens was under the influence of the autosomal recessive lpr gene and was segregated together with the lymphadenopathy into the F2 generation. The aberrant expression of F and P-B antigens reflects the alteration of terminal carbohydrate structure of glycolipids and glycoproteins on the membrane of the LNC. It is tempting, therefore, to speculate that such alterations in the membrane structure might represent disturbances in cellular recognition resulting in unusual expansion of the T cells in the early life of MRL/1 mice.

Absorption↗
PubMed1983

Acid hydrolases in the initiation of ischemic myocardial necrosis.

Alterations in myocardial acid hydrolases in acute ischemia were studied in relation to the evolution of cardiac cellular necrosis by the determination of cathepsin D, acid phosphatase (AcPase), and beta-glucuronidase activities of the myocardial fractions and by electron microscopic cytochemical studies on AcPase in the canine heart. In the normal myocardium, the same level of activity of acid hydrolases was found in sarcoplasmic reticulum (SR) as in the lysosome fraction. In electron microscopy, AcPase reaction products were observed markedly in SR and moderately in lysosomes, in residual bodies, and in Golgi apparatus. In the ischemic myocardium, at 20 to 30 min after coronary ligation, activation of these enzymes was observed in both SR and lysosomes, and at 60 to 90 min they were decreased in the particles and, in turn, increased in the cytoplasm accompanying the ischemic fine structural changes. At 2 to 3 hr those acid hydrolase activities in the cytosol were decreased, indicating the loss of enzymes from necrotic myocardial cells. Acid hydrolases are the most important factor for the evolution of ischemic myocardial necrosis by being activated not only in lysosomes but also in SR and by being released to the cytoplasm to disintegrate the cellular structures.

Acid Phosphatase↗
PubMed1983

Electron microscopic cytochemical studies on acid phosphatase activity in acute myocardial ischemia.

Alterations in the localization and the intensity of acid phosphatase activity were studied electron microscopically in acute ischemic myocardial cells in the dog, in relation to processes of cellular degradation. In normal myocardial cells, the acid phosphatase activity was concentrated in the terminal cisternae, the longitudinal elements and the subsarcolemmal cisternae of the sarcoplasmic reticulum and the primary lysosomes. Activity was moderate in the secondary lysosomes, residual bodies and Golgi apparatus. As early as 15 min after coronary ligation the intensity of acid phosphatase activity increased in the enlarged lysosomes and the sarcoplasmic reticulum of the ischemic myocardial cells. Fine deposits of the reaction product were distributed in the sarcoplasm around lysosomes and the sarcoplasmic reticulum after 30 min, and the activity began to decrease in lysosomes and in the sarcoplasmic reticulum. One to 3 hours after ligation, intramitochondrial dense deposits appeared, and the reaction product decreased both in lysosomes and the sarcoplasmic reticulum. The fine reaction product, which leaked from lysosomes and the sarcoplasmic reticulum, was scattered in the sarcoplasm and was accompanied by fine structural changes indicating cellular necrosis. From these findings it is strongly suggested that acid hydrolases in lysosomes and the sarcoplasmic reticulum are closely related to the necrotic process in ischemic myocardial cells.

Acid Phosphatase↗
PubMed1982

Polyclonal antibody synthesis by bone marrow cells of New Zealand black mice. I. Assessment of activity in an adoptively transferred histocompatible host.

The activity of polyclonal antibody synthesis (PAS) of bone marrow cells (BMC) was assessed by enumerating anti-trinitrophenyl (TNP) plaque-forming cells (PFC) or immunoglobulin-secreting cells (IgSC) generated in the spleen of BMC-reconstituted syngeneic or H-2-compatible hosts. BMC of NZB mice generated large numbers of anti-TNP PFC or IgSC as compared with those of C57BL/6 mice or H-2-compatible, nonautoimmune strains of mice (BALB/c, DBA/2 and B10 . D2 mice). Causes for the enhanced PAS activity were explored. Susceptibility to known B cell mitogens was examined and it was shown that spleen cells of the recipients of NZB BMC were refractory to the mitogens while PAS was apparent and acquired responsiveness after 15 days as those from nonautoimmune strains of mice. Furthermore, environmental factor(s) did not seem to be responsible for the enhanced PAS, since BMC from nonautoimmune BALB/c mice showed little PAS activity when transferred into heavily irradiated NZB mice and those of NZB mice showed enhanced PAS activity when transferred into B10 . D2 or BALB/c mice. It seems most likely that enhanced PAS activity of BMC of NZB mice is a genetically inherent phenomenon. PAS activity of BMC and spleen cells of NZB mice increased significantly with increasing age of mice.

Animals↗
PubMed1982

Polyclonal antibody synthesis by bone marrow cells of New Zealand Black mice. II. Cellular basis of PAS activity of NZB bone marrow cells.

In the preceding report, enhanced polyclonal antibody synthesis (PAS) activity of bone marrow cells (BMC) of NZB mice was shown. Cells involved in its activity among BMC population were explored in this report. Antibody-forming cells (AFC) already existing in the bone marrow were not responsible for this activity since depletion of AFC by passage through a Sephadex G-10 column did not affect the numbers of anti-TNP AFC and immunoglobulin-secreting cells (IgSC) in the spleen of BMC-reconstituted mice when assayed 7 days after the transfer. Thy-1-positive cells among BMC population and host thymus were not relevant to PAS. Suppressor cells seemed to play little role as observed in transfer of mixed BMC population from NZB and BALB/c mice. PAS activity was prominently observed in surface immunoglobulin-positive cells. Significance of enhanced PAS activity was discussed with reference to autoantibody production.

Animals↗
PubMed1982

Increased resistance to effector cell blockade in antibody-producing cells of NZB mice.

Susceptibility of B lymphocytes fo 'effector cell blockade', i.e. in vitro inactivation of antibody-forming cells by specific antigen, was studied in NZB and C57BL/6 mice. Mice were immunized either with dinitrophenylated dextran (DNP-Dex) or DNP-keyhole limpet hemocyanin (DNP-KLH). It was shown that both direct and indirect anti-DNP plaque-forming cells (PFC) from older NZB mice were less affected by the preincubation with the corresponding antigen than those from age-matched C57BL/6 mice or young NZB mice. The increased resistance of B lymphocytes in aged NZB mice to the effector cell blockade may play a significant role for generation of autoantibody-forming cells in the presence of excess amounts of corresponding antigens.

Aging↗
PubMed1982

Studies on intracardiac acid hydrolases in the ischemic myocardial necrosis.

Activities and subcellular distributions of acid hydrolases, cathepsin D, acid phosphatase and beta-glucuronidase in myocardial subfractions were determined serially with reference to the initiation of myocardial necrosis in dog hearts with acute ischemia. The following results were obtained: 1) In the normal myocardium, respectable activities of three enzymes were obtained either in the sarcoplasmic reticulum or in the lysosome-containing fraction. 2) Thirty min after coronary ligation, an increase in the activities was observed in both lysosome and sarcoplasmic reticulum fractions of the ischemic heart muscle. After 60 to 90 min these activities were decreased rapidly in both fractions to about 70% of those of the normal myocardium with an increase in the cytosolic activity. Two to 3 hours after ligation, the reduction in the cytosolic activity was noted, indicating an escape of the enzymes from the necrotic myocardium. The subcellular distribution of these enzymes was further altered in the ischemic heart muscle for 12 to 14 hours reflecting an infiltration of the interstitial cells. These findings suggest that activation and release of acid hydrolases not only in lysosomes but also in the sarcoplasmic reticulum are one of the primary and the earliest factors for the evolution of ischemic myocardial injury which leads to necrosis.

Acid Phosphatase↗
PubMed1982

Electron microscopic studies on the ATPase activity in myocardial infarction -changes in the early myocardial infarction.

Ultracytochemical changes in ATPase activity of ischemic myocardial cells were studied in the dog heart by electron microscopy in the early stage of myocardial infarction and compared to the fine structural alterations in the ischemic myocardium. 1) In the normal myocardial cell, ATPase activity was observed intensely in the terminal cisternae (TC) of the sarcoplasmic reticulum (SR), and moderately in the myofilaments in the longitudinal SR and around the gap junctions of the intercalated discs. 2) The most striking change in the ischemic myocardial cells was the reduction in the ATPase reaction product in the TC of the SR and along the gap junctions 60 min after coronary ligation, simultaneously with swelling of the TC and the appearance of mitochondrial dense deposits. The reaction product began to decrease at 30 min on the myofilaments, and for 3 to 12 hours no reaction product was observed except irreversible morphologic changes in 60 to 70% of the longitudinal SR in the ischemic subendocardial cells. 3) A decrease in ATPase activity was recognized in the early stage of myocardial ischemia simultaneously with the fine structural changes of myocardial cells and it is considered to be one of the signs of ischemic irreversibility.

Adenosine Triphosphatases↗
PubMed1981

Genetic and clinical patterns of heritable cerebellar ataxias in adults. II. Clinical manifestations.

Clinical data on 244 probands with spinocerebellar types, 163 with late cortical cerebellar atrophies (LCCA), and 180 with olivopontocerebellar atrophies (OPCA) were analysed. Spinocerebellar cases were divided into three according to their estimated genetic mechanisms: recessive, dominant, or sporadic. Ages of onset were identical in sporadic spinocerebellar types, LCCA, and OPCA, the average being about 50. They showed highly correlated clinical patterns. In the light of other evidence, these diseases may represent a premature aging process in the central nervous system, probably determined multifactorially. Recessive spinocerebellar cases were very few. There were 127 cases of spinocerebellar types with dominant inheritance, characterised by age of onset around 33, colourful ocular signs, and spasticity. A large family with this disease was described in which 34 patients were affected through five generations. The computed tomograms showed an almost normal cerebellum and electronystagmograms indicated patterns of vestibulocular impairment. No necropsied case was available among the present material, but in pathological reports of similar cases, major lesions were found in the ventral and the dorsal spinocerebellar tracts, Clarke's columns, and the posterior columns in the spinal cord. This disease, or hereditary spastic ataxia, represented a fairly well-defined entity inherited dominantly among a group of cases with spinocerebellar types, and it was separable from LCCA or OPCA, not only on clinical and genetic grounds, but by a predominantly spinal involvement.

Age Factors↗
PubMed1981

Studies on the Na+-K+-ATPase in myocardial infarction.

Changes in the cardiac sarcolemma in myocardial infarction were studied by both determination of Na+-K+-ATPase activity and SDS gel electrophoretic analysis of sarcolemmal proteins in the canine heart. Ninety minutes after coronary ligation, Na+-K+-ATPase activity in ischemic myocardium was decreased significantly to approximately 36% of that of non-ischemic myocardium, and it remained at the lower level for 28 days. By SDS gel electrophoresis, reduction of the protein band with molecular weight of 111,000, which is suggestive of the main component of ATPase, was observed simultaneously with the reduction of Na+-K+-ATPase activity. These results indicate that ischemia for 90 minutes produces substructural changes in the sarcolemma indicating irreversible myocardial changes.

Animals↗
PubMed1981

Regional changes in cardiac structural proteins in myocardial infarction: biochemical and histologic correlates.

1. Quantitative analysis of structural proteins from a minute amount of myocardial tissue was performed from 10 mu thick cardiac tissue slices weighing 2 to 5 mg by the extraction in glycerol solution and by sodium dodecylsulfate (SDS) gel electrophoresis, and these changes were compared with the histologic alterations in the striated structure of the adjacent cardiac slices in the experimental myocardial infarction in the dog. 2. Approximately 69 micrograms of structural proteins were obtained from 1 mg of the normal heart muscle. In the central portions of the myocardial infarction, reductions in myosin heavy chain (HC), light chain (LC) 1 and alpha-actinin were observed at 12 to 24 hours after the coronary occlusion followed by the decrease in myosin LC 2 at 48 hours. Those changes became intense at 72 hours to 7 days, but restored gradually at 14 to 28 days. 3. Alterations in the striated structure of cardiac muscle fibers of the adjacent tissues slices were found simultaneously with the changes in structural proteins. At 12 to 24 hours after the coronary ligation increase in eosinophilia and overstretch of cross-striation were observed. The findings of coagulation necrosis, loss of striation, fragmentation, swelling of A-band, etc. of the infarcted fibers were markedly observed at 48 hours to 7 days, but the histologic restoration of cardiac fibers was found with the recovery of the infarcted tissue at 14 to 28 days after the coronary ligation. 4. Changes in the compositions of structural proteins corresponded well to the alterations in the striated structure in chronology and in quantity.

Actinin↗
PubMed1981

Alterations in cardiac troponin subunits in myocardial infarction.

1. Alterations in troponin subunits in myocardial infarction were studied in the dog heart by the analysis of troponin-tropomyosin complex, i.e, native tropomyoin, of total structural proteins in SDS gel electrophoresis, and by the measurement of degree of activation of actomyosin-ATPase by Ca++. 2. At 12 to 24 hours after coronary ligation, reductions in TN-C and tropomyosin were observed followed by a decrease in TN-I at 48 hours. The relative contents of these subunits were the lowest at 72 hours to 7 days falling to less than 10% of those in the non-ischemic myocardium. On the contrary, TN-T was preserved through the course of myocardial infarction. 3. Actomyosin-ATPase activity was increased at 12 to 24 hours after coronary ligation and then reduced rapidly at 24 to 48 hours together with the degradation of myosin. However, the activation of actomyosin-ATPase by Ca++-troponin-tropomyosin was reduced already at 12 hours simultaneously with the reduction in TN-C, and almost completely lost at 48 hours. 4. Troponin subunits and actomyosin-ATPase activity returned to those of the control myocardium at 28 days after coronary ligation indicating the recovery of infarcted tissue.

Adenosine Triphosphatases↗