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Biomedical subjects

T Katagiri

Publications and source records attributed to T Katagiri.

At least 307 records · Page 17Linked to original sources
PubMed1987

Alterations in fine structures of myofibrils and structural proteins in patients with dilated cardiomyopathy--studies with biopsied heart tissues.

Ultrastructural and biochemical alterations in myofibrils (Mf) were studied in biopsied myocardial tissues in 11 patients with dilated cardiomyopathy (DCM) and compared with those in non-hypertrophic control and secondary hypertrophic (SHT) heart muscles. Transverse diameters of biopsied cardiac myocytes increased significantly in both of SHT and DCM, and ultrastructural changes were similar in quality in both of them. Volume densities of Mf were 61.1 and 59.9% on average in control and SHT myocardial cells, respectively, and they were not significantly different. But in DCM volume density was significantly less (49.8% in left ventricular myocytes), and inverse relation between that and diameter of cardiac myocytes was observed (p less than 0.01). Electrophoretic pattern and relative composition of major structural proteins from control and SHT heart muscles were similar and statistically insignificant. In DCM, relative contents of myosin heavy chain and alpha-actinin decreased significantly and distinctively in all of cases suggesting primary degradation of myofibrils.

Biopsy↗
PubMed1986

Composition and central projections of the pudendal nerve in the rat investigated by combined peptide immunocytochemistry and retrograde fluorescent labelling.

The central distribution of the afferent and efferent projections of pelvic striated muscles, the pudendal and sciatic nerves, were systemically investigated in rats by retrograde tracing techniques combined with immunocytochemistry using antibodies to 9 neuropeptides. True Blue was injected into either the pelvic muscles, pudendal or sciatic nerves. Seven days later the spinal cord and dorsal root ganglia (L3-S2 levels) were processed for immunocytochemistry. Injection of tracer into the pelvic muscles labelled dorsomedial, ventral and dorsolateral motoneuron groups of the L6 segment and a few sensory neurons in the respective dorsal root ganglia. Pudendal nerve injection also labelled the same motoneuron groups, 50% of neurons of the retrodorsolateral column and numerous sensory neurons of the dorsal root ganglion. Concomitant labelling of pudendal and sciatic nerves with different fluorescent tracers revealed a small number of double-labelled cells in the dorsal root ganglia but only single-labelled cells in the retrodorsolateral nucleus. Enkephalin-, somatostatin- and neuropeptide Y-containing fibres were particularly abundant in and around dorsomedial and dorsolateral groups as well as the intermediolateral cell column. We conclude that in the rat (a) the pudendal nerve has motor, sensory and autonomic (parasympathetic) components in contrast to the sciatic which is primarily motor and somatosensory, (b) some afferents from these nerves exhibit pre-spinal convergence and (c) dorsomedial and dorsolateral motoneuron groups are homologous to Onuf's nucleus in man.

Animals↗
PubMed1986

Paul-Bunnell antigen in murine T cell differentiation: abnormal expression in MRL/Mp-lpr/lpr mice.

Expression of Paul-Bunnell (P-B) antigen was studied on lymphoid cells of normal mice, autoimmune MRL/Mp-lpr/lpr (lpr), and congenic MRL/Mp-+/+(+/+) mice. Evidence was presented that the P-B antigen is a differentiation-associated antigen of murine T cells: Cells with high P-B pattern and density on normal T cells increased as their differentiation proceeded in the peripheral lymphoid tissues. In thymus, P-B antigen was predominantly expressed on hydrocortisone resistant and PNA nonagglutinable cells. The degree of P-B expression on T cells of peripheral lymphoid tissues correlated well with that of Lyt-1 and Lyt-2 antigens (r greater than 0.7). Similar studies on lymphocytes obtained from lpr and +/+ mice at different ages revealed that P-B antigen on the peripheral T cells of lpr mice began to decrease at 6 to 8 wk of age and that the majority of the cells became low P-B cells by 10 wk, accompanied by decrease in expression of Lyt-1 antigen. In contrast, its expression on lpr thymocytes did not differ from that of +/+ or normal mice. The lymph node cell population of lpr mice at the height of the lymphadenopathy was composed of 80% of low P-B and dull Lyt-1 cells and less than 15% of "normal" P-B and Lyt-1 positive cells. These results indicate distorted differentiation of the lpr peripheral lymphocytes that are responsible for the massive lymphadenopathy and the morbid processes.

Aging↗
PubMed1986

A VIP/PHI-containing pathway links urinary bladder and sacral spinal cord.

Nerve fibres containing VIP and the co-produced PHI are found in the dorsal horn and autonomic centres of the sacral spinal cord and in pelvic organs. We have investigated the origin of these nerve fibres and a possible peptide-containing pathway linking pelvic viscera with the spinal cord of the cat and rat using neurochemical and neurosurgical procedures, retrograde tracing and immunocytochemistry. Cell bodies were located in the dorsal root ganglia (after colchicine injection), pelvic ganglia and bladder wall. Capsaicin treatment induced a loss of VIP/PHI from the dorsal horn. Retrograde tracing from the bladder revealed True Blue labelled cells in the dorsal root ganglia (L6, S1), parasympathetic nuclei and pelvic ganglia. Labelled cells were sequentially immunostained for VIP/PHI which were numerous in pelvic ganglia and scattered and weak in dorsal root ganglia. Pelvic nerve section induced a decrease of VIP/PHI immunoreactivity from the spinal cord and no change or a minimal increase in immunoreactive nerve fibers of the bladder. Thus pelvic visceral afferents with cell bodies in the dorsal root ganglia are a significant source of VIP/PHI-containing fibres in the sacral dorsal horn.

Afferent Pathways↗
PubMed1986

An established MRL/Mp-lpr/lpr cell line with null cell properties produces a B cell differentiation factor(s) that promotes anti-single-stranded DNA antibody production in MRL spleen cell culture.

The cell line established from the lymph node cells of an MRL/lpr mouse, was found to have null cell properties in that it lacked Thy-1, Lyt-1 and Lyt-2 as well as sIg, and continued to grow in the absence of exogeneously added lymphokines such as IL-2 and IL-3. Interestingly, this cell line (KML1) or a soluble factor(s) produced by it promoted anti-ssDNA antibody production in cultures of MRL/lpr spleen cells. The factor did not induce cell proliferation. Therefore, it is concluded that the cell line KML1 produced at least a B-cell differentiation factor, but not IL-2 or IL-3 as far as detected with the respective lymphokine-dependent cell lines.

Animals↗
PubMed1986

Ultrastructural changes in the sarcoplasmic reticulum in acute myocardial ischemia.

We investigated the morphologic changes in the sarcoplasmic reticulum (SR) in acute myocardial ischemia, induced by occlusion of the coronary artery in the canine heart, by freeze-fracture of SR in situ and in vitro, and they were compared to the alterations in Ca++-stimulated ATPase activity and protein composition of the isolated SR. Both SR in situ and the isolated SR exhibited typical intramembranous particles with diameters of 70 to 90 A in freeze-fracture replicas. The intramembranous particle density of the P face in SR in situ was 3,319 +/- 75 (mean +/- SE) per micrometer2 and that in the isolated SR was 2,667 +/- 60; particles were more numerous on the concave (P) face than on the convex (E) face. In ischemia for 30 to 60 min a significant decrease in the number of particles was found in SR in situ, and the corresponding change was noted in the isolated SR. Simultaneous decreases in Ca++-stimulated ATPase activity and the major ATPase protein of the SR were recognized. The close correlation of the changing pattern between the reduction in Ca++-ATPase and that in intramembranous particle density during ischemia supports the suggestion that a large part of the intramembranous particles represent ATPase protein itself. Decrease in the SR membrane particles strongly suggests the degradation of ATPase protein in the process of ischemic myocardial injury.

Adenosine Triphosphatases↗
PubMed1986

Anterior dislocation of the shoulder. Experience with a modified clavicular harness.

There is a high incidence of recurrence after traumatic dislocation of the shoulder. In this study of 417 patients, we found that initial dislocation below the age of 30, dislocation with capsular detachment, dislocation without tuberosity fracture and a short period of fixation after reduction were predisposing factors. We have designed a modified clavicular harness and have used it in the treatment of 41 such high risk patients. We found no recurrences during an observation period of one year.

Adolescent↗
PubMed1985

Activities of a soluble extract from lymphoid cells of MRL mice. Effect on B cell differentiation in vitro.

Soluble extract (sEx) was prepared from lymphoid cells of MRL/Mp-lpr/lpr(MRL/l) mice with early lupus nephritis and also of MRL/Mp-+/+ (MRL/n) mice. sEx from lymph node and spleen T cells of MRL/l mice had an activity for B cells to differentiate into immunoglobulin-producing cells but that of MRL/n mice did not show such an activity. sEx of MRL/l mice also enhanced the in vitro response of B cells to a suboptimal dose of lipopolysaccharide. Implication of these phenomena in the development of lupus nephritis is discussed.

Animals↗
PubMed1985

Studies on collagen in the experimental myocardial infarction.

The healing process of myocardial infarction was studied with special reference to the production of collagen by the determinations of prolylhydroxylase (PHase) activity and contents of hydroxyproline (Hyp) of the collagen subfractions, i.e., neutral salt soluble (NSC), acid soluble (ASC) and insoluble collagens (ISC) in comparison with histologic observation of the proliferation of connective tissue in the canine heart. The contents of Hyp in NSC and ASC increased in the infarcted tissue 5 days after coronary ligation prior to its increase in ISC. The content of Hyp in NSC, which is a precursor of ASC and ISC, reached the maximal value at 7 days and that reached the maximal value in ASC 7 to 14 days after coronary ligation. ISC increased markedly after 14 days. PHase activity increased on the second day and attained to the highest at 5 to 7 days. Proliferation of fibroblasts paralleled with the increases in PHase activity and NSC, and an increase in collagen fiber did with the contents of ISC. From these results it is concluded that in the healing stage of myocardial infarction, PHase was activated earlier than the increase in immature collagen in the infarcted area which was observed 5 to 7 days after coronary ligation and was followed by the production of mature collagen after 14 days.

Animals↗
PubMed1985

Hyperglycaemic effect of glucagon administered intracerebroventricularly in the rat.

The intracerebroventricular (icv) administration of 100 ng glucagon resulted in more prolonged and pronounced elevations of plasma glucose levels than the intravenous injection of 100 ng glucagon. Insignificant changes in plasma IRI and IRG levels after icv glucagon administration contrasted to marked increases in both IRI and IRG levels after the iv injection. Icv glucagon-induced hyperglycaemia was completely prevented by the prior administration of atropine, phentolamine or hexamethonium, and partially inhibited by bilateral adrenalectomy, but not by propranolol pretreatment. These findings suggested that the hyperglycaemic effect is brought about through cholinergic and alpha-adrenergic neural pathways and partly via the adrenal medulla.

Adrenalectomy↗
PubMed1985

Ultrastructure of the sarcoplasmic reticulum in the ischemic myocardium.

Fine structural changes in the sarcoplasmic reticulum (SR) in myocardial ischemia, induced by occlusion of the anterior descending branch of the left coronary artery in the canine heart, were studied by the freeze-fracture technique in situ and in vitro and compared to the alterations in Ca2+-stimulated ATPase activity and sodium dodecyl sulfate gel electrophoresis of the isolated SR. Both SR in situ and the isolated SR exhibited the typical intramembranous particles of 70-90 A in freeze-fracture replicas, and the numbers of particles were more numerous in the concave face (PF) than in the convex face (EF). The numbers of particles in the PF were 2748/micron 2 on the average. In ischemia for 1-2 hr, a significant decrease in the numbers of the particles was found in SR in situ, and corresponding changes were noted in the isolated SR. Decreases in Ca2+-stimulated ATPase activity and in the major protein band of ATPase were recognized simultaneously. The close correlation of the changing patterns between the reduction in Ca2+-ATPase and that in the intramembranous particle density during ischemia supports the suggestion that a large part of the intramembranous particles represents ATPase protein itself. The decrease in the particles of SR membrane indicates the degradation of ATPase in the process of ischemic myocardial necrosis.

Animals↗
PubMed1984

Aplysia oxymyoglobin with an unusual stability property.

Native oxymyoglobin was isolated directly from the radular muscle of Aplysia kurodai with complete separation from metmyoglobin on a DEAE-cellulose column. It was examined for its spectral and stability properties. The spectrum of Aplysia MbO2 , which lacks the distal histidine, is very similar to those of mammalian oxymyoglobins , the alpha-peak being higher than the beta-peak and the absorbance ratio being 1.03. Its stability, however, is quite different from those of the mammalian oxymyoglobins , and Aplysia MbO2 is found to be extremely susceptible to autoxidation. Its rate is one-hundred times higher at pH 9.0, and its pH dependence is unusual and much less steep, when compared with sperm whale MbO2 as reference.

Animals↗
PubMed1984

125I-glucagon-degrading activity in acid-saline extracts of rat salivary gland.

The antibody-binding ability of the glucagon-like substance in rat submaxillary gland acid saline extract was examined by affinity chromatography, and the biological activity studied using the isolated liver perfusion method. We found that the glucagon-like substances in acid saline extract could not be bound to anti-glucagon antibody and that the gel-filtration peak on ultrogel AcA 54 could increase neither glucose nor cyclic AMP output from isolated perfused rat liver. Furthermore, the radioactivity peak of 125I-glucagon on Bio Gel P-6 column chromatography moved from its original position and eluted in later fractions after incubation with an acid saline extract of the submaxillary gland. In consequence, there was 125I-glucagon degrading activity in the submaxillary gland, but no glucagon-related peptide. Therefore, it is suggested that the glucagon-like substance, which has been reported in acid saline extract of the rat salivary gland, may be an artifact due to tracer degrading activity.

Animals↗
PubMed1984

Synaptosomal localization and release of glucagon-like materials in the rat brain.

The subcellular localization of glucagon-like materials in the thalamus-hypothalamus and brain stem of the rat was investigated. Both glucagon immunoreactivity (GI) determined by C-terminal specific antibody and glucagon-like immunoreactivity (GLI) determined by non-specific antibody were enriched in the microsomal and synaptosomal fractions relative to the nuclear, myelin and mitochondrial fractions. Furthermore, the synaptosomal fraction of both the thalamus-hypothalamus and brain stem incubated in Krebs-Ringer bicarbonate buffer with 55 mM K+ at 37 degrees C released GI and GLI in the presence of Ca++. These findings suggested that glucagon-like substances detected in the brain have a role in the synaptic function.

Animals↗