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Biomedical subjects

T Takayanagi

Publications and source records attributed to T Takayanagi.

At least 163 records · Page 9Linked to original sources
PubMed1987

Contribution of the complement system to antibody-mediated binding of Trypanosoma gambiense to macrophages.

The role of complement in the process of binding of trypanosomes to macrophages in the presence of specific antibody was studied. The aggregation of trypanosomes observed at the optimal antigen-antibody ratio or in the presence of excess antigen inhibited the binding. Complement caused clumped trypanosomes to dissociate, and the free trypanosomes, which were presumed to be coated with antibody that had fixed complement, readily attached to surfaces of phagocytes. Thus, complement was shown to contribute at the site of the antigen-antibody reaction to the creation of an environment suitable for the binding. It seems likely that the trypanosomes dissociated by complement adhered to C3 receptors of the macrophage. However, in the absence of complement and in regions of antibody excess, free trypanosomes also attached to phagocytes. Thus phagocytes may also have receptors for the Fc portion of aggregated antibody. Complement activated by the alternate pathway also enhanced attachment of trypanosomes to phagocytes, but the effect was not as rapid as it was when complement was activated by classical means.

Animals↗
PubMed1986

Glutamate dehydrogenase and its isozyme activity in olivopontocerebellar atrophy.

Evaluation of glutamate dehydrogenase (GDH) in 12 patients with olivopontocerebellar atrophy showed deficiency of the enzyme in the group as well as in each patient. The activity of total GDH was 77.7% of that in controls. We also demonstrated two components of this enzyme differentiated by their thermostabilities. The activity of the heat-labile component was remarkably reduced in patients although that of the heat-stable component showed the same magnitude as in controls. These data suggest that GDH deficiency is mainly caused by its heat-labile component deficiency, which might be related to the pathogenesis of this disease.

Aged↗
PubMed1986

Regularity in the change of serum creatine kinase level in Duchenne muscular dystrophy. A study with long-term follow-up cases.

Changes in the serum creatine kinase (CK) level according to the disease course were regressed to an exponential function Y = A e-ex in each case of 28 Duchenne muscular dystrophy (DMD) through a long-term follow-up study. The regression to this formula implies that DMD muscle would decay by the leaking of a certain amount of CK into the circulation in proportion to the existing muscle. The diminution coefficient "r" was significantly reduced in puberty as compared with ages around ten. The cases of rapid progression showed a high rate of CK decrement in puberty. The diminution rate of CK is suspected to reflect the difference between the rate of muscle growth and primary muscle decay.

Adolescent↗
PubMed1986

The successful system in long-term cultivation of Trypanosoma gambiense bloodstream forms.

Rat astroglioma cell line (GA-1) was extremely useful for long-term in vitro cultivation of Trypanosoma gambiense blood-stream forms. Parasites could be continuously grown at 37 degrees C for more than 200 days in the culture system, consisted of HEPES-buffered RPMI 1640 (pH 7.2, 300 milliosmole/kg) supplemented with 20% inactivated fetal calf serum in the presence of GA-1 cells. Parasites cultured for more than 200 days still retained not only their virulence for mice but also their original antigenic type. Morphologically, they resembled host infected bloodstream forms by way of having a subterminal kinetoplast and surface coat. The best growth rate of trypanosomes was obtained with 1 X 10(6) GA-1 cells/25 cm2 culture flask. Under this culture condition trypomastigote form populations increased in number up to 7-8 X 10(6) trypanosomes/ml by day 3 after initiation of the culture. The population doubling time in this culture system within the first 24 hours was almost the same as in mice. Most of the cultured trypanosomes were in suspension, but 15-20% of the parasites adhered to the surface of GA-1 cells. The culture system was also shown to be useful for cloning of T. gambiense which is important for separation of mutants.

Animals↗
PubMed1985

Tuberoinfundibular dopaminergic system and anterior pituitary dopamine receptor in Shy-Drager syndrome.

Tuberoinfundibular dopaminergic system (TIDA) together with anterior pituitary dopamine receptor was evaluated in 9 patients with Shy-Drager syndrome (SDS) through the responses of serum growth hormone (GH) and prolactin (PRL) to dopaminergic stimulation or dopamine receptor inhibition. A variety of abnormal responses of serum GH and/or PRL following the administration of these drugs suggests the TIDA involvement as well as the nigrostriatal system and moreover the different degeneration processes in each dopaminergic system in SDS.

Aged↗
PubMed1985

Evaluation of renal parathyroid hormone receptor function in myotonic dystrophy.

Endocrine abnormalities in myotonic dystrophy (MyD) reflect some of the multi-systemic involvement resulting from this disorder. One of these, abnormal insulin secretion, is considered to be caused by receptor dysfunction. Bone abnormalities, cataract and calcium transport defect suggest the abnormal calcium metabolism in MyD. The calcium metabolism is chiefly regulated by parathyroid hormone (PTH). An interest in the similarity between MyD and pseudohypoparathyroidism, which is a disorder of PTH receptor dysfunction, encouraged the authors to evaluate renal PTH receptor function from the responses of urinary adenosine 3',5'-monophosphate (cAMP) and phosphate excretion after administration of human PTH(1-34). The responses of cAMP were high in 3 cases, low in one case, but normal in the 4 other cases. The phosphaturic responses were elevated in 3 cases, reduced in 3 cases, and normal in 2 other cases. Since these abnormal responses closely mimic those in hypoparathyroidism, there may also be renal PTH receptor dysfunction in some cases of MyD. The results of the present study suggest another peptide hormone receptor defect, similar to insulin, which supports the hypothesis of generalised receptor dysfunction in MyD.

Adult↗
PubMed1985

Electrophysiological analysis of warming up phenomenon in myotonia.

The after discharges following grip and percussion in myotonia of 4 cases with myotonic dystrophy were evaluated in repetitive percussion or grip, in cold exposure and in warm exposure electromyographically. By repetition, the after discharges reduced markedly. After 2 or 3 trials, after discharges disappeared or became short duration. During local cooling (15 degrees C-20 degrees C), the amplitude and the prolongation in the duration of after discharges were marked, although these enhanced after discharges were reduced by repetition even in cooling. During local warming (40 degrees C-42 degrees C), the after discharges became less marked or disappeared. Both the warming of muscle and the repetitive movements reduced the duration of abnormal after discharges. These effect might be explained on the same mechanism which was the change of the ion transport in muscle membrane, and could be called as warming up phenomenon together. The degree of these after discharges are close related to the degree of myotonic phenomenon. Myotonia is the disorder of primarily the electrical excitabilities, not the contractile properties. So the method of evaluation of after discharges electromyographically is very valuable compared to the measurement of the relaxation process which was used popular in evaluation of myotonia in the past.

Action Potentials↗