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Biomedical subjects

T Morikawa

Publications and source records attributed to T Morikawa.

At least 271 records · Page 15Linked to original sources
PubMed1980

Inhibitors of procollagen N-protease. Synthetic peptides with sequences similar to the cleavage site in the pro alpha 1(I) chain.

A series of peptides was synthesized with amino acid sequences identical with the cleavage site at which the procollagen N-protease cleaves the N-terminal propeptide from the pro alpha 1 chain of type I procollagen. Peptides up to 11 residues in length did not serve as substrates for the enzyme, an observation consistent with the demonstration that the N-protease will not cleave denatured procollagen or dissociated pro alpha chains. Several of the peptides, however, served as effective inhibitors of the cleavage of procollagen. Comparison of the inhibitor activities of peptides of varying lengths suggested that the L-phenylalanine found three residues to the left of the cleavage site was important for inhibitor activity. This suggestion was confirmed by synthesis of analogues of inhibitory peptides in which L-phenylalanine was replaced by D-phenylalanine, tyrosine, lysine, aspartic acid, or glycine.

Animals↗
PubMed1980

Analytic study of epileptic absence seizures and effect of sodium valproate treatment.

Two hundred and seventy eight absence seizures were recorded from 60 patients by an intensive monitoring device. They were divided into two subtypes, typical and atypical absences based on their ictal discharges whether the spike-wave rhythm was at 3 cps or not. These two absence seizures did not differ so much with regard to loss of consciousness except that: 1) the durations of discharge in atypical absences were longer than those of typical ones, 2) the recovery from clouded consciousness to a state of full-awareness was apparently delayed in atypical absences after the termination of epileptic discharges, 3) the oral automatisms were more associated with typical absences and the decreased postural tones with atypical absences. By a numerical analysis of two parameters of spike-wave, that is, its frequency ad rhythmicity, it was shown that absences with spike-waves slower than 30 cps and with poor rhythmicity which roughly corresponded with atypical absences were more therapy-resistant in comparison with those having 3 cps spike waves and good rhythm which were usually typical absences. Sodium valproate was more effective on typical absences, however, there was no difference between typical and atypical absences in the therapeutic maintenance concentrations of serum valproate acid. We would like to emphasize that the comparison of the symptomatology between typical and atypical absences is of significance not only for understanding the etiology of the epilepsies but for the guideline of practical pharmacotherapy.

Electroencephalography↗
PubMed1979

Conformational studies of oxytocin analogues with different ring sizes. I. Circular dichroism.

Circular dichroic spectra were measured for three analogues of deamino-oxytocin of different ring sizes where the disulfide group of oxytocin is replaced by the (CH2)n group. Their backbone rings are composed of different numbers of atoms, i.e., they are nineteen, twenty and twenty-one for [1,6-aminopimelic acid]oxytocin (n = 1), [1,6-aminosuberic acid]oxytocin (n = 2) and [1,6-aminoazelaic acid]oxytocin (n = 3), respectively. The pH dependence of the circular dichroism spectra indicates that the conformation of [1,6-aminoazelaic acid]oxytocin is different from those of others and the temperature dependency reveals that the conformation of [1,6-aminopimelic acid]oxytocin is most rigid. [1,6-Aminosuberic acid]oxytocin is biologically most active among three derivatives and their biological activities are related to the conformation and internal motions of the peptide hormone analogues.

Circular Dichroism↗
PubMed1979

Status epilepticus in childhood: a retrospective study of initial convulsive status and subsequent epilepsies.

A retrospective study was carried out on 261 patients with various epilepsies who had undergone convulsive status epilepticus prior to the subsequent onset of epileptic seizures. 1. Convulsive status epilepticus was found more in partial epilepsy and secondary generalized epilepsy at about the same rate, and evidently less in primary generalized epilepsy. On the average, three-fourths commenced their convulsive disorders with initial status epilepticus. 2. There were free intervals of years following initial status and preceding subsequent epilepsy. The interval was evidently shorter, less than two years, in a majority of patients with secondary generalized epilepsy, whereas the interval was mostly longer, more than six years, in patients with partial epilepsy. 3. The permanent deficient sequelae resulting from initial status were most closely associated with secondary generalized epilepsy. This was also exemplified by the higher rate of atrophic change on CCT. On the contrary, such permanent sequelae were less marked in partial epilepsy especially of complex seizure. 4. It was concluded that secondary generalized epilepsy resulted in cases with more severe brain damage within a relatively shorter interval, whereas complex partial seizure resulted from less severe damage with an obviously longer interval following convulsive status epilepticus.

Adolescent↗