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Biomedical subjects

M Tobo

Publications and source records attributed to M Tobo.

10 recordsLinked to original sources

Simultaneous measurement of temperature and velocity maps by inversion recovery tagging method.

A new method, called the inversion recovery (IR) tagging method, for simultaneous measurement of temperature and velocity maps of flowing fluid has been developed. The present method employs a set of tagging pulses which acts as an inversion pulse of the conventional IR method, based on the temperature dependence of the spin-lattice relaxation of water proton in a fluid, and has the advantage of being able to compensate the reduction of the NMR signal intensity due to flow motion and to reduce the total time to measure these maps. First, the accuracy of the temperature measurement of stagnant doped water in a differentially heated cell using the conventional IR method, as the basic sequence of the IR tagging method, has been evaluated. The accuracy was within 10% of the temperature difference DeltaT = 17.2 degrees C and the measurable temperature resolution was within +/-0.5 degrees C. Then temperature and velocity maps of the flowing doped-water through a cooled pipe were measured simultaneously by the IR tagging method, and the accuracy of temperature measurement was evaluated. The accuracy obtained using the present method was within 15% of the temperature difference DeltaT = 15 degrees C.

Humans↗

Action of chronically administered antidepressants on the serotonergic postsynapse in a model of depression.

A theory of excessive transmission of serotonin (5-HT) in depression has been previously proposed. The purpose of the present study was to test this theory further by using the model of depression in rats induced by L-5-hydroxytryptophan (5-HTP), the precursor of 5-HT. The drug effects on 5-HTP (25 mg/kg) induced behavioral depression were tested by chronic administration using methysergide which is a postsynaptic blocker of 5-HT, or by comparable clinical doses of antidepressant drugs. Methysergide (2 mg/kg) blocked 5-HTP induced depression on days 8 and 22 after initiation of medication by 70% and 83%, respectively. Among antidepressants, mianserin (2 mg/kg) was the first to produce an effect, displaying a 38% effect as early as 1 day after the start of medication and having blocking effects of 52% and 72% on days 8 and 22. Desipramine (5 mg/kg), doxepine (5 mg/kg), imipramine (5 mg/kg) and trazodone (10 mg/kg) showed no significant effect on days 1 and 8, and on day 22, 64, 36, 33 and 32% blocking, respectively. Amitriptyline had an initial effect of 41% at a dose of 10 mg/kg. Clomipramine (5 mg/kg), zimelidine (6 mg/kg) and chlorpromazine (2.5 mg/kg), which is a neuroleptic, showed no effect. Considering these results in light of recent data reported on the 5-HT synapse, it was suggested that 5-HTP induced depression may be induced by excessive transmission of 5-HT and that some antidepressant drugs may produce their effect by blocking this postsynaptic transmission. Based on these results, the mechanisms of human depression were discussed.

5-Hydroxytryptophan↗

Familial occurrence of adult-type neuronal ceroid lipofuscinosis.

The adult type of neuronal ceroid lipofuscinosis (NCL) occurred in a 49-year-old man and his 51-year-old sister. They showed episodic stuporous and psychotic states, mental retardation, generalized convulsions, and ichthyosis vulgaris. At autopsy the woman had excessive accumulation of lipofuscin throughout the CNS. The degree of neuronal lipopigment accumulation was very severe in the neurons of the thalamus, substantia nigra, inferior olivary nuclei, motor nuclei of the brain stem, and cerebral cortex. Mental symptoms, such as stupor, excitement, hallucinations, and delusions, were the predominant clinical manifestations and so were misdiagnosed as schizophrenia. Though the clinical diagnosis of the adult type of NCL (Kufs' disease) is difficult because of its wide variety of manifestations, symptoms such as episodic psychotic and stuporous states accompanied by convulsive disorders with mild neurologic signs may be an indication of this disease.

Age Factors↗

Computed tomography in Pick's disease.

Pick's disease is a rare cause of dementia. We studied two clinical cases of Pick's disease in its early stage. A computed tomography (CT) demonstrated lobar atrophy affecting primarily the anterior portions of the frontal lobes and the inferior portions of the temporal lobes. The fact that the characteristic pattern of lobar atrophy is already apparent in the early stage of the disease was demonstrated.

Aged↗

Glial fibrillary acidic protein in tuberous sclerosis.

We examined two cases of tuberous sclerosis for the presence of glial fibrillary acidic protein (GFAP) using the immunoperoxidase technique. The majority of abnormal giant cells in the cerebral cortex showed no reaction to anti-GFAP. Some abnormal cells in the cortical tuber and white matter showed a weak positive reaction. All of the subependymal tumor cells showed no GFAP in their cytoplasm. The abnormal giant cells in tuberous sclerosis, morphologically similar to gemistocytic astrocyte, are not accompanied by antigenic properties of GFAP.

Adolescent↗

Presenile dementia with motor neuron disease -an additional case report-.

A 51-year-old male has suffered the gradual onset of difficulty with memory, concentration and cognition at age 50. He has progressively developed severe dementia accompanied by muscle wasting and fasciculation prominent in the upper arms and shoulders and the bulbar muscles, EMG and muscle biopsy revealed denervation patterns and a CT-scan showed moderate cerebral atrophy. Cases of presenile dementia with motor neuron disease reported in Japan have been reviewed and the possibility of a new clinico-pathologic entity is discussed.

Amyotrophic Lateral Sclerosis↗

Unusual case of presenile dementia.

A 63-year-old woman showed the dominant clinical features of aphasia as the initial symptom in the course of presenile progressive dementia. Computerized axial tomography showed strikingly dilated Sylvian fissures, particularly in its posterior aspect, in the presence of moderate diffuse cortical atrophy. EEG revealed a slowdown in activity with the dominance in the left fronto-temporal area. The radiographic and EEG findings correlated well with the clinical data. This case was compared with those of presenile dementia previously reported. This is a unique case report of presenile dementia.

Aphasia↗