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Biomedical subjects

N Takeda

Publications and source records attributed to N Takeda.

At least 541 records · Page 30Linked to original sources

Evolution of enterovirus 70 in nature: all isolates were recently derived from a common ancestor.

The data of large RNase T1-resistant oligonucleotide mapping of enterovirus 70 (EV 70) previously reported (Takeda et al., Virology 134, 375-388, 1984) were subjected to further genetical analysis to estimate the evolutionary rate of genome RNA of EV 70 and to clarify the phylogenetic relationship among isolates. A proportion of common spots between strains decreased as the year elapsed and eventually, only seven spots were common to all the 16 isolates tested, indicating that the substitution is scattered throughout the genome. On the other hand, some specific sets of spots were conserved among geographically or epidemiologically related strains. Base sequence variation of the isolates was deduced according to Aaronson et al. (Nucleic Acids Res. 10, 237-246, 1982) from pariwise comparison of the common spots and used as a genetic distance between them. The base substitution rate of virus genome was estimated by regression analysis of the genetic distance of the isolates against the sampling time. A fairly constant and rapid rate was obtained; it was 1.83 X 10(-3)/base/year. Based on the substitution rate, genetic distance and sampling time of the strains, the phylogenetic tree of EV 70 was constructed using Unweighted Pair Group Method Using Arithmetic Averages (UPGMA) (Nei, Molecular Population Genetics and Evolution, North Holland, Amsterdam, 1975). The tree supports the previous hypothesis that evolution of EV 70 started from a single common ancestor. The time of its emergence was estimated to be 1967 +/- 15 months. The virus branched into many strains early during the first pandemic and has evolved in a divergent fashion, yielding genetically polymorphic viruses in the world.

Biological Evolution↗

Spinal metastases of cerebral glioblastoma: the value of computed tomographic metrizamide myelography in the diagnosis.

Spinal metastases from cerebral glioblastoma via the cerebrospinal pathway are rarely detected when the primary tumors are under apparent control. The authors report two adult patients with cerebral glioblastoma who developed spinal symptoms referable to spinal seeding without neurological and computed tomographic findings of the recurrence of the primary tumors. Computed tomographic metrizamide myelography clearly revealed minute deposits of perispinal metastatic tumors that could not be detected by conventional myelography. Even perispinal mass lesions so minute that they are revealed only by computed tomographic metrizamide myelography can invade the spinal cord and cause clinical symptoms.

Adult↗

Gilles de la Tourette's syndrome and schizophrenia.

A Gilles de la Tourette's syndrome (TS) patient is described who experienced a schizophrenic episode 11 years after TS onset. Analogies and differences between the two syndromes are reviewed, leading to the conclusion that TS is a definite entity independent from schizophrenia, but that they share some common features of symptomatology and pathophysiology and have closely related anatomical lesions.

Adolescent↗

Initiation of poliovirus plus-strand RNA synthesis in a membrane complex of infected HeLa cells.

An in vitro poliovirus RNA-synthesizing system derived from a crude membrane fraction of infected HeLa cells was used to analyze the mechanism of initiation of poliovirus plus-strand RNA synthesis. This system contains an activity that synthesizes the nucleotidyl proteins VPg-pU and VPg-pUpU. These molecules represent the 5'-terminal structure of nascent RNA molecules and of virion RNA. The membranous replication complex is also capable of synthesizing nucleotidyl proteins containing nine or more of the poliovirus 5'-proximal nucleotides as assayed by the formation of the RNase T1-resistant oligonucleotide VPg-pUUAAAACAGp or by fingerprint analysis of the in vitro-synthesized RNA. Incubation of preformed VPg-pUpU with unlabeled nucleoside triphosphates resulted in the formation of VPg-pUUAAAACAGp. This reaction, which appeared to be an elongation of VPg-pUpU, was stimulated by the addition of a soluble fraction (S-10) obtained from uninfected HeLa cells. Preformed VPg-pU could be chased into VPg-pUpU in the presence of UTP. Our data are consistent with a model that VPg-pU can function as a primer for poliovirus plus-strand RNA synthesis in the membranous replication complex and that the elongation reaction may be stimulated by a host cellular factor.

Cell Membrane↗

A survived case of diabetic nonclostridial gas gangrene and the review of the literatures on microbiological findings.

Nonclostridial gas gangrene in diabetics results in poor prognosis. In this paper, a survived case of diabetic nonclostridial gas gangrene caused by Proteus vulgaris and Streptococcus faecalis is described and microbiological findings of 31 cases of the literatures including our own case were reviewed. Twenty of 31 cases died (64.5%). The microbiological findings in 30 cases revealed an average of 1.8 organism per case. Predominant aerobes were E. Coli (56.7%), Streptococcus faecalis (16.7%), aerobic Streptococcus and Proteus (both 13.3%) in that order. Anaerobes were found in 12 of 20 cases and isolated anaerobes were Bacteroides (8 cases) and Peptococcus (4 cases). The role of specific bacteria in causing severe form of nonclostridial gas gangrene in diabetics was suggested.

Adult↗

Effects of diltiazem hydrochloride in diabetics.

The effects of diltiazem hydrochloride on insulin secretion and glucose tolerance were studied in diabetic subjects treated with dietary management alone for their glycemic control. Sixteen diabetic subjects with heart complaints and/or abnormal electrocardiographic findings which were compatible with diagnosis of ischemic heart disease were given diltiazem hydrochloride 90 mg daily for a mean of 9.3 +/- 1.0 (SE) months and oral 100 g glucose tolerance tests (o-GTT) were performed before and after the administration of diltiazem hydrochloride. As a control group, 14 diabetic patients with roughly the same level of fasting blood glucose and the same degree of glucose intolerance were selected, and in these patients oral 100 g glucose tolerance tests were also performed before and after a mean follow up period of 12.6 +/- 1.5 months. Although improvement in glucose tolerance was observed at the end of the trial in the group of patients with diltiazem hydrochloride, control group also showed improved glucose tolerance and there was no significant difference in the change of glucose tolerance between both groups. No significant change of IRI response in oral 100 g glucose tolerance test was observed in both groups. We could, therefore, conclude from these observations that diltiazem hydrochloride with usual clinical dosage dose not exert unfavourable effects on glucose tolerance and insulin secretion in the mild diabetic patients.

Aged↗

Localization of calcitonin gene-related peptide in the organ of Corti of the rat: an immunohistochemical study.

The localization of calcitonin gene-related peptide (CGRP)-like immunoreactive (CGRPI) structures in the cochlea was examined in the rat using immunocytochemistry. Numerous CGRPI fibers entered the organ of Corti in the intraganglionic spiral bundle and formed a dense fiber patch at the base of the inner hair cells. Much fewer, but still a significant number of CGRPI fibers were seen at the synaptic region of the outer hair cells. Since no immunoreactive cells were seen in the organ of Corti and spinal ganglion, these fibers may be one of the major components of the olivocochlear bundles originated from the superior olivary complex.

Animals↗

Computed tomographic and histopathological studies of pontine glioma.

Correlative study of computed tomography (CT) and pathologic findings was performed in eight cases of pontine glioma. All patients except one had chemotherapy and radiotherapy, with no surgical intervention. On initial CT scans, all patients had hypodense lesions in part or the whole of the pons, and there was evidence of mass effect. Four of eight cases showed contrast enhancement. After chemotherapy and radiotherapy, swelling of the pons and the width of the hypodense areas decreased. The hypodense areas sometimes became isodense in correlation with clinical amelioration. After several months of remission in responding cases, ring-enhanced lesions reappeared at the primary site, together with recurrent neurological signs. Pathological study postmortem was focused on the histological counterparts of the CT findings of central and perifocal hypodense areas and contrast enhancement. In six of seven treated cases, the central hypodense area surrounded by ring enhancement was shown to be coagulation necrosis. Higher cellularity and hypervascularity with glomeruluslike structures of small vessels were generally observed in enhanced areas. The areas diffusely infiltrated by tumor cells, but not enhanced in CT scans, had few abnormal vessels. Tumor cells were seen not only in hypodense areas around the enhanced portion but also in areas far beyond the enhanced portion. Exophytic expansion of tumor was observed in two cases on postmortem examination. One of these was detected by CT scans before death.

Astrocytoma↗

Relationship between the myofibrillar ATPase activity of human biopsy material and hemodynamic parameters.

The myofibrillar ATPase activity and pyrophosphate gel electrophoretic pattern of native myosin of fresh human left ventricular papillary muscles were examined in 52 cases of mitral valve replacement. The myofibrillar ATPase activity of hypertrophied myocardium did not differ from that of non-hypertrophied myocardium (mean +/- SD, 36.2 +/- 8.7 vs 31.8 +/- 8.6 nmolPi/mg/min, ns) and there was no significant difference in myofibrillar ATPase activity as a function of left ventricular enddiastolic pressure. Pyrophosphate gel electrophoresis of myosin revealed the presence of two components. It is questionable whether the component of higher electrophoretic mobility (approximately 25-35% in concentration) is identical with rat ventricular myosin VM-1 because an increase in this component seems to correlate with a decrease of myofibrillar ATPase activity, its concentration was significantly higher in the hearts with left ventricular hypertrophy, high enddiastolic pressure, high aortic pressure or low cardiac index. From these results, it is not necessarily clear whether hemodynamic overload in valvular heart diseases can alter left ventricular myofibrillar ATPase activity, but it can be said that the overload influences the concentration of the two components of native myosin revealed by pyrophosphate gel electrophoresis.

Adenosine Triphosphatases↗

Mycinamicins, new macrolide antibiotics. IX. Chemical ionization mass spectral studies on mycinamicins.

Chemical ionization (CI) mass spectra of new macrolide antibiotics, mycinamicins are reported. Protonated molecules (MH+) are observed as base peaks in the CI mass spectra of all components. Fragmentations are mainly restricted to the glycosidic linkages and the resulting aglycone and sugar-derived ions appear regularly in their mass spectra. Moreover, characteristic fragment ions involving carbon-carbon bond fission are found in the CI mass spectra of the epoxyenone-containing components, mycinamicins I (1) and II (2). The mechanism for the formation of the ion species is also discussed.

Anti-Bacterial Agents↗

["True" posterior communicating artery aneurysm presenting the abducens nerve palsy].

Most of "so-called" posterior communicating artery aneurysms previously reported, originated from the internal carotid-posterior communicating junction. Aneurysms arising from the posterior communicating artery itself are very rare. The abducens nerve palsy caused by cerebral aneurysm is also very rare. We are reporting a case with the saccular aneurysm arising directly from the distal half of the posterior communicating artery presenting the abducens nerve palsy. This 73-year-old woman who had no treatment with hypertension for several years was admitted for sudden onset of severe headache, vomitting and unconsciousness on March 1, 1984. She opened her eyes when addressed and had disorientation, urinary incontinence, right-hemiparesis and left-abducens nerve palsy. A 4-vessel angiography revealed the saccular aneurysm originating directly from the distal half of the posterior communicating artery. The patient underwent left-frontotemporal craniotomy on the 27th day after subarachnoid hemorrhage under Hunt & Kosnic Grade 3. The aneurysm originated directly from the distal half of the posterior communicating artery and directed inferior-posterior-laterally below the oculomotor nerve. The neck was successfully clipped. Immediate post-operative course was uneventful until the 7th day after surgery. On the 8th day she had hypertensive intraventricular hemorrhage and expired. The autopsy could not be obtained. The saccular "true" posterior communicating artery aneurysm with isolated unilateral abducens nerve palsy as seen in our case has not been reported. Considering the operative findings, we thought the aneurysmal dome contacted directly with the abducens nerve.

Abducens Nerve↗

Origins of histamine-containing fibers in the cerebral cortex of rats studied by immunohistochemistry with histidine decarboxylase as a marker and transection.

The origins of histamine-containing fibers in the cerebral cortex were examined by means of the retrograde tracer technique of horseradish peroxidase (HRP)-immunohistochemistry with histidine decarboxylase (HDC) as a marker for the histamine neuron system. Total transection of the brain rostral to the posterior hypothalamus resulted in disappearance of HDC-like immunoreactive (HDCI) fibers in the cerebral cortex, but total transection caudal to the posterior hypothalamus did not decrease the number of HDCI fibers in the cortex, suggesting that HDCI fibers in the cerebral cortex originate in the posterior hypothalamus. The projection of HDCI neurons from the posterior hypothalamus to the cerebral cortex seemed to be bilateral because hemi-transection of the brain rostral to the posterior hypothalamus resulted in a bilateral decrease of HDCI fibers in the cerebral cortex with ipsilateral predominance. After injection of HRP into the cerebral cortex, numerous cells containing both HRP granules and HDCI structures were found bilaterally in the tuberal, caudal and postmamillary magnocellular nuclei, with ipsilateral predominance. These findings indicate that HDCI cells in the above nuclei give rise to axons extending bilaterally to the cerebral cortex.

Animals↗

Effect of a new eburnamine derivative, RU 24722, on the turnover of monoamines in mouse brain: selective and reversible decrease of noradrenaline.

A new eburnamine derivative, RU 24722, is structurally similar to vincamine and is known to cause a specific and reversible decrease of noradrenaline in rat brain. The effects of RU 24722 on the turnover of monoamines in mouse brain were investigated. The noradrenaline level in mouse brain was significantly decreased after administration of RU 24722 10 mg/kg i.p. with significant increases in 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxyphenylacetic acid and homovanillic acid. The levels of these compounds returned to the control levels within 5 h. The levels of dopamine, serotonin, 5-hydroxyindoleacetic acid and histamine were not affected by this dose of RU 24722. Higher doses of RU 24722 (25 and 50 mg/kg) decreased the concentration of serotonin significantly with a significant increase in 5-hydroxyindoleacetic acid. There were no differences between the patterns of change in the forebrain, midbrain and hindbrain. These results indicate that RU 24722 increased the turnover of noradrenaline and dopamine in mouse brain at the dose of 10 mg/kg and the turnover of serotonin was also increased only at higher doses.

3,4-Dihydroxyphenylacetic Acid↗