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Biomedical subjects

H Terada

Publications and source records attributed to H Terada.

At least 307 records · Page 17Linked to original sources
PubMed1985

Quantitative determination of water in the skin by 1H NMR.

Studies were made on determination of the amount of water in rat skin by 1H NMR spectroscopy. The NMR spectrum obtained depended on how the skin was packed into the NMR tube. Consistent results were obtained by packing the skin into a specially designed NMR cell. By this technique the amount of water in the skin could be measured accurately, and results were comparable with those obtained by differential scanning calorimetry. The water content of the skin of rats was consistently about 20% more in females than in males.

Animals↗
PubMed1984

Molecular basis of the protonophoric and uncoupling activities of the potent uncoupler SF-6847 [3,5-di-tert-butyl-4-hydroxybenzylidene)malononitrile) and derivatives. Regulation of their electronic structures by restricted intramolecular rotation.

We reported recently (Yoshikawa, K. and Terada, H. (1982) J. Am. Chem. Soc. 104, 7644-7646) that the potent uncoupler of oxidative phosphorylation SF-6847 [3,5-di-tert-butyl-4-hydroxybenzylidene)malononitrile) shows unique intramolecular restricted rotation of the malononitrile moiety. In this study, values for the activation energy Ea of the restricted rotation of SF-6847 derivatives with the same alkyl chain R in both ortho positions of the phenolic hydroxyl group were determined from the temperature-dependent change in the 1H-NMR signals of their aromatic protons. The Ea values of the neutral forms of these derivatives were found to be the same irrespective of R, but those of the anionic forms increased with increase in the alkyl chain length of R. It was found that the restricted rotation of the malononitrile moiety regulates its electron-withdrawing ability in such a way as to keep the acid dissociability of these derivatives similar, overcoming the effect of steric hindrance by R. The protonophoric activity of these derivatives, in a phospholipid bilayer membrane and their uncoupling activity in rat-liver mitochondria were both found to depend on Ea of their anionic forms. The stability of the uncoupler anions regulated by the restricted rotation of the malononitrile group in a nonpolar membrane environment was found to be important for exhibition of these activities. The hydrophobicity of the anionic forms of these derivatives was suggested also to be affected by the intramolecular rotation.

Animals↗
PubMed1984

Antiepileptic effect and serum levels of clorazepate on children with refractory seizures.

Clorazepate dipotassium is rapidly decarboxylated to yield desmethyl diazepam. The antiepileptic effect of clorazepate was studied in 29 epileptic children with refractory seizures. Their ages were ranged from one year 9 months to 20 years (mean 11 years 6 months). Serum clorazepate levels were also determined in 16 patients. The mean initial dose was 0.91 mg/kg/day, and the dose was increased up to 3 mg/kg/day. Within several days after initiation of clorazepate therapy, a decrease in seizure frequency was seen in patients in whom clorazepate was effective. Excellent results (decrease in seizure frequency by more than 80%) were obtained in 7 patients (24.1%), a moderate improvement with a 50 to 80% decrease was seen in 7 patients (24.1%), and a partial improvement with less than 50% decrease was seen in 7 patients (24.1%). No benefit was seen in 8 patients (27.7%). Serum clorazepate levels in patients with excellent results were 31 to 77 ng/ml (mean 55 ng/ml), those in patients with a moderate improvement were 130 to 225 ng/ml (mean 163 ng/ml), and those in patients with a partial improvement were 142 to 518 ng/ml (mean 273 ng/ml). Serum clorazepate levels in patients with no benefit were 34 to 97 ng/ml (mean 56 ng/ml). There was no direct relationship between serum clorazepate levels and clinical response. The results of this study indicate the efficacy of clorazepate for epileptic children with refractory seizures.

Adolescent↗