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Biomedical subjects

T Takayanagi

Publications and source records attributed to T Takayanagi.

At least 19 recordsLinked to original sources
PubMed1992

Inhibition of IgM antibody-mediated aggregation of Trypanosoma gambiense in the presence of complement.

This paper deals with the immune reaction between Trypanosoma gambiense and monoclonal IgM mouse antibody at equivalence with or without rabbit complement. Antibody-mediated trypanosome clumps formed in the absence of complement, and were readily dissociated by complement to become free. In the presence of complement, on the other hand, T. gambiense were not aggregated by the antibody. Free parasites adhered readily to cultured peritoneal macrophages. Complement-mediated dissociation of the clumped trypanosomes in the equivalence area released a large number of previously bound surface antigens. These antigens were capable of binding again to fresh IgM antibody. Experimental results further indicated that the complement system caused a functional alteration, changing the multivalent nature of the IgM antibody in the immune complex into a univalent one. This phenomenon is of great advantage to the infected host in clearing pathogens in vivo, as it allows more antibodies to attach to trypanosomes and subsequently initiate complement activity.

Animals↗
PubMed1992

Novel N-linked oligo-mannose type oligosaccharides containing an alpha-D-galactofuranosyl linkage found in alpha-D-galactosidase from Aspergillus niger.

Structures of oligosaccharides from Aspergillus niger alpha-D-galactosidase [EC 3.2.1.22] were studied. Purified alpha-D-galactosidase was treated with N-glycosidase F, and six kinds of oligosaccharides were isolated by gel chromatography and anion-exchange chromatography. The structures of the oligosaccharides were determined by 1H-NMR and compositional analysis to be Man5GlcNAc2, Man6GlcNAc2, Man9GlcNAc2, GlcMan9GlcNAc2, GalMan4GlcNAc2 and GalMan5GlcNAc2. From mild acid hydrolysis, methylation analysis and ROESY spectral analysis, it was ascertained that the galactosyl residue in two oligosaccharides was in the furanose form and was bound to mannose at the nonreducing end with an alpha 1-2 linkage (GalfMan4GlcNAc2 and GalfMan5GlcNAc2).

Aspergillus niger↗
PubMed1992

Oscillatory variations of cutaneous blood flow in newborns using a laser Doppler flowmeter.

Oscillatory variations of cutaneous blood flow were studied using laser Doppler flowmetry in 20 newborns. Simultaneous monitoring of cardiorespiratory state was also performed. The frequency and amplitude of oscillatory curve varied, even on identical skin regions in each infant. When their respiration and heart rate were irregular, the frequencies of oscillatory curves were significantly higher and with a larger amplitude than when cardiorespiratory function was regular. The frequencies of oscillatory curves at two symmetrical points of an individual were not different, but a significant difference in the oscillatory cycle was recognized at two asymmetrical points. Distributions of peak-to-peak time periods of oscillatory curves were studied in nine healthy and four sick newborns. Seven of nine healthy newborns had more than two peaks in their distributions, while only one peak with a narrowly-spread distribution was observed in the four sick newborns with almost exclusively periodic breathing throughout monitoring. In conclusion, we speculate that cardiorespiratory state and some neurogenic control affects the variations observed. In addition, the narrowly-spread distribution of each time period appeared to be an important indicator of morbidity.

Heart Rate↗
PubMed1992

Central motor conductivity in aged people.

The conductivity of motor neurons in 26 aged females (mean age 79 years) was analyzed by the conventional conduction method and by pulsed magnetic stimulation and compared with that in 14 younger controls. In aged people, slow motor conduction velocities were found in peripheral nerves. Central motor conduction time (CMCT) in relaxed muscle was shorter in the aged people, although CMCT was normal in mildly contracted muscle. These findings coincide with the results studied in Parkinson's disease, although these subjects were not diagnosed as having Parkinson's disease. Aged people generally have an anteflexed posture, slow movements, and poor postural reflexes, and have been reported to have a decrease in the dopamine level which is relatively earlier than that of other transmitters in the basal ganglia. This may account for the present finding that aged people have neurophysiological abnormalities in CNS which are similar to those in Parkinson's disease.

Adult↗
PubMed1992

[Diurnal sleep apnea in myotonic dystrophy].

We investigated diurnal sleep apnea in myotonic dystrophy with respiratory inductive plethysmography. Five of eight patients met criteria for sleep apnea syndrome and had central apnea mainly. In a case showing periodic breathing with apnea like Cheyne-Stokes type breathing, the duration of apnea and breath was even and the tidal volume went waxing and waning regularly. In the other four cases, central apneas were observed in sequence, but the duration of apnea and the tidal volume changed variously. Large breaths between apneas elevated arterial oxygen saturation rather than stable breaths without apnea. We suspected that hypoxemia, which exacerbated by involvement of respiratory muscles, supine position and sleep, initiated the hyperventilation between apneas. And then the saturation of oxygen raised by hyperventilation would cause central sleep apnea.

Adult↗
PubMed1992

[Aggravation of hypoxemia in supine position in myotonic dystrophy].

Myotonic dystrophy (MyD) involves a variety of systems. Respiratory disorders are common, namely elevation of diaphragm, alveolar hypoventilation, aspiration pneumonia and sleep apnea. We evaluated respiratory involvement. The subjects were 11 patients with MyD. Also 6 patients with limb girdle muscular dystrophy (LG) were examined to be compared with MyD. Both groups had the similar activities of daily living. All of them never complained of dyspnea. Arterial blood gas studies were performed in supine position and standing position. A new evidence was found that hypoxemia was aggravated and alveolar-arterial oxygen pressure difference was increased in supine position in MyD. Next, pulmonary function tests were done in supine position and sitting position. Functional residual capacity (FRC) were more reduced in supine position in MyD compared with LG. The value to subtract closing capacity from FRC was negative in supine position in MyD, showing closing phenomenon. We propose the mechanism of the aggravation of hypoxemia may be the following. The reduction of FRC caused by respiratory muscle involvement brings out the closing phenomenon. Abnormal uneven distribution of ventilation-perfusion ratio happens and then hypoxemia is worsened in supine position in MyD.

Adult↗
PubMed1992

[X-ray computed tomographic scans of lower limb and trunk muscles in facioscapulohumeral muscular dystrophy].

X-rays computed tomographic (CT) scans of muscles of the lower limbs and the trunk in 14 patients with facioscapulohumeral muscular dystrophy (FSH) were studied. The CT scans showed that the affected muscles were decreased in density and size. The laterality of muscular involvement was sometimes observed. The muscular lesions in the lower limbs showed proximal distribution. In the thigh, the hamstrings were affected first, the adductor muscles second, and then the muscular involvement progressed to the quadriceps femoris muscle. In the lower leg, the gastrocnemius and soleus muscles were relatively spared as compared with the tibialis anterior muscle. In the lumbar girdle, the abdominal muscles were involved first, the gluteal muscles second, the back muscles third, and the psoas major muscle were relatively spared. The muscular weakness of this distribution exacerbated lumbar lordosis. The neck muscles were less affected than those of the lumbar girdle. The CT scans in FSH demonstrated the characteristic pattern of muscular involvement, which differed from the inherited muscular diseases such as Duchenne muscular dystrophy, myotonic dystrophy, and others.

Adolescent↗
PubMed1992

[Multivariate analysis of the clinical signs in late cortical cerebellar atrophy (LCCA) in Japan--compared with olivo-ponto-cerebellar atrophy (OPCA) and hereditary cortical cerebellar atrophy (HCCA)].

We investigated the clinical features of 179 patients with late cortical cerebellar atrophy (LCCA) comparing with 382 patients with olivo-ponto-cerebellar atrophy (OPCA) and 91 patients with hereditary cortical cerebellar atrophy (HCCA) using multivariate analysis. They had no significant difference in durations from onset. Disorders of finger-nose test were of more severity and disorders of heel-knee test were less involved in LCCA than in HCCA. Eye movements tended to be normal in LCCA. LCCA showed more depressive and euphoric character than OPCA and HCCA. Analysis of LCCA and OPCA demonstrated that LCCA revealed hypotonia in muscles, normal or weak reactions of muscle stretch reflexes. There existed 21.4 percent of cases which could not be discriminated by multivariate analysis using clinical signs in LCCA and OPCA. Multivariate analysis of LCCA and HCCA, which are very similar in clinical signs, showed 66.3 percent of discriminatory rate. Thus, we could diagnose them to a certain extent only by clinical signs.

Aged↗
PubMed1992

[Mechanism to induce scoliosis in Duchenne muscular dystrophy--a study of paraspinal muscle by X-ray computed tomography].

We studied mechanism to induce scoliosis in Duchenne muscular dystrophy (DMD) by use of X-ray computed tomography (CT) of paraspinal muscles. CT examination of paraspinal muscles was performed on 15 DMD patients at the following six levels; 1. Th3 vertebrae (upper thoracic spine level) 2. Th6 vertebrate (middle thoracic spine level) 3. Th10 vertebrae (lower thoracic spine level) 4. L1 vertebrae (upper lumbar spine level) 5. L3 vertebrae (middle lumbar spine level) 6. L5 vertebrae (lower lumbar spine level). We evaluated the degeneration of paraspinal muscle by a decrease in radio-density of the muscle which indicates infiltration of fatty tissue. The degeneration of the lateral portion of paraspinal muscle was more marked than that of the medial portion. The muscle was most severely affected at the middle lumbar spine level, showing a tendency to increase degeneration at the lower level of the spine. In cases showing laterality of the degeneration of paraspinal muscle, the less affected muscle on CT was located at the convex site of scoliosis. We speculate that the scoliosis occurs when DMD patients have asymmetrical paraspinal muscle degeneration, leading them to take compensatory posture.

Adolescent↗
PubMed1992

[A new method of gait analysis in Duchenne muscular dystrophy].

We assessed gait in Duchenne muscular dystrophy (DMD) mainly by determining alteration of foot pressure using a new gait analyzing procedure. DMD patients showed a characteristic foot pressure pattern according to their degree of dysfunction. In stage I disease, the observed pattern was the same as that of normal controls. In stage II, the period during which the center of foot pressure was seen in the front part of the foot was prolonged. This change became more marked in stage III. In stage IV, the center of foot pressure began at the head of the ossis metatarsalis primi and moved back and toward the lateral side. Thereafter, the center of foot pressure again moved forward along the outside of the foot. These changes were considered to be the result of talipes equinus and waddling gait, which are commonly demonstrated in patients with DMD.

Adolescent↗
PubMed1992

Immunological activities of monoclonal IgG1 antibody against Trypanosoma gambiense.

The present paper deals with the immune reaction between a monoclonal IgG1 antibody and Trypanosoma gambiense. The aggregation of trypanosomes, immune adherence to macrophages and protection against infection are associated with the antibody. IgG1-mediated clumping of trypanosomes is readily dissociated by the addition of complement. Dissociation of the clumped trypanosomes in the equivalence area released approximately fifty percent of previously bound surface antigens. These antigens were capable of binding again to new IgG1 antibody. Complement deposition rendered bivalent IgG1 antibody in the immune complex functionally univalent. Such an event in the presence of complement is of great advantage to the infected host in killing pathogens in vivo, as it allows more antibodies to attach to surface antigens and subsequently to initiate complement activity.

Animal Population Groups↗
PubMed1992

Diversity of complement-mediated immune reaction to Trypanosoma gambiense.

Intact and papain-treated Trypanosoma gambiense clone populations, each expressing special antigens on their cell surfaces, were mixed with rabbit antiserum in the presence of complement. Two distinct types of immune reaction between trypanosomes and antisera were observed: clumping followed by dissociation (CD) and inhibition of aggregation (IA). Special antigens on the cell surface of trypanosomes exposed after papain digestion are implicated in both types of immune reaction. IA was considered to be more effective as an immunological response which would allow the infected host to clear the pathogen without any obstruction of capillaries and impairment of blood flow caused by clumping masses of trypanosomes.

Animals↗
PubMed1992

[Pathogenesis of juvenile muscular atrophy of unilateral upper extremity in reference to venous congestion of epidural space].

MRI and dynamic CT studies were performed in a young male with juvenile muscular atrophy of unilateral upper extremity (JM) with onset at age 15 and clinical course of 2 years. The mechanism of development of congestion in vertebral venous plexus was considered. Dynamic CT of the head in the neck flexion showed rapid reflux of blood from the intervertebral veins into the posterior internal vertebral venous plexus at the C5-C6 level and consequent congestion. It is speculated that in this patient some mechanism associated with head anteflexion led to a reflux into the valveless posterior internal vertebral venous plexus and congestion as well. Furthermore, it could be considered that anterior shift of the dural sac at the time of head anteflexion plays an important role in the development of this internal vertebral venous plexus congestion in JM.

Adolescent↗
PubMed1991

Isolation and characterization of thermostable chitinases from Bacillus licheniformis X-7u.

Four kinds of thermostable chitinase were isolated from the cell-free culture broth of Bacillus licheniformis X-7u by successive column chromatographies on Butyl-Toyopearl, Q-Sepharose, and Sephacryl S-200. We named the enzymes chitinases I(89 kDa), II(76 kDa), III(66 kDa) and IV(59 kDa). Chitinases II, III and IV possessed extremely high optimum temperatures (70-80 degrees C), showing remarkable heat stability. Chitinases II, III and IV produced (GlcNAc)2 and GlcNAc from colloidal chitin and chitinase I predominantly produced (GlcNAc)2. The action pattern of chitinase I on PN-(GlcNAc)4 also showed a stronger propensity to cleave off the (GlcNAc)2 unit from the non-reducing end than the other three chitinases. Chitinases II, III and IV catalyzed a transglycosylation reaction that converted (GlcNAc)4 into (GlcNAc)6.

Amino Acids↗
PubMed1991

Dissociation of IgG antibody-mediated clumps of Trypanosoma brucei gambiense by complement.

Aggregated trypanosome masses that had formed in the region of equivalence in the absence of complement were readily dissociated by complement. Complement-mediated dissociation of the clumped trypanosomes in the area of equivalence released approximately 50% of the previously bound surface antigens. These antigens were capable of rebinding to new IgG antibody. Experiments indicated that complement deposition altered the bivalent IgG antibody in the immune complex into a univalent form. The occurrence of such an event in the presence of complement provides a great advantage to the infected host in the killing of pathogens in vivo, as it enables a greater number of antibodies to attach to surface antigens and subsequently initiate complement activity.

Animals↗
PubMed1991

[A case of Japanese encephalitis demonstrating characteristic changes in MRI].

A 40-year-old woman developed high fever and headache. Five days later, she was admitted because of consciousness disturbance and tremulous movements in upper extremities. The paired sera showed more than fourfold elevation in complement fixation titer to Japanese encephalitis virus. She was diagnosed as Japanese encephalitis from the clinical features and serological tests. Magnetic resonance imaging (MRI), which was performed about seven months after the onset, revealed abnormal intensity areas bilaterally in the thalamus, hippocampus, substantia nigra, globus pallidus and white matter around the lateral ventricle. Eight months after the onset, she was left with bradykinesia, disturbance of rightening reflex, emotional lability and impairment of recent memory with a long period of amnesia, including not only her illness and subsequent events but also about several years before her illness. The characteristic memory dysfunction seems to be due to disorder of bilateral hippocampus, where MRI revealed abnormal intensity areas. And disorder of medial thalamic nucleus would be related to emotional liability. The relation between the clinical features and MRI findings is also discussed.

Adult↗
PubMed1991

Seroepidemiological study for HBV markers and anti-delta in Kenya.

An HBV carrier rate of 3.0% in outpatients and 1.4% in school children, was found in a sero-epidemiological survey in Muranga District, Kenya. The prevalence of anti-Delta in HBV carriers was 42%. The prevalence of HBV carriers and HBV marker positive cases was high in family members of HBV carriers. The yearly attack ratio of HBV was low in primary school children, non-carrier family members and even carrier family members. Mother to baby vertical transmission was very high when mothers were HBeAg positive HBV carriers. Such vertical transmission may now be of major importance.

Adolescent↗