Hole Spin Resonance and Spin-Orbit Coupling in a Silicon Metal-Oxide-Semiconductor Field-Effect Transistor.

We study hole spin resonance in a p-channel silicon metal-oxide-semiconductor field-effect transistor. In the subthreshold region, the measured source-drain current reveals a double dot in the channel. The observed spin resonance spectra agree with a model of strongly coupled two-spin states in the presence of a spin-orbit-induced anticrossing. Detailed spectroscopy at the anticrossing shows a suppressed spin resonance signal due to spin-orbit-induced quantum state mixing. This suppression is also observed for multiphoton spin resonances. Our experimental observations agree with theoretical calculations.

Relationship of low-density lipoprotein particle size to plasma lipoproteins, obesity, and insulin resistance in Japanese men.

OBJECTIVE: To determine the clinical characteristics of patients with small low-density lipoprotein (LDL) particles among Japanese men with mild glucose intolerance and to investigate the relationship of LDL particle size to the levels of other plasma lipoproteins, obesity, insulin resistance, and blood pressure (BP). RESEARCH DESIGN AND METHODS: The subjects were 40 men with impaired glucose tolerance or diabetes treated by diet alone, and 40 healthy men matched for age and body mass index (BMI) were used as control subjects. LDL particle size was measured using gradient gel electrophoresis. RESULTS: Of the 40 patients with glucose intolerance, 19 had small LDL (particle size < 25.5 nm) compared with only 4 of the 40 control subjects. In the patients with small LDL, the plasma levels of cholesterol, triglycerides, and apolipoprotein B, the fasting serum immunoreactive insulin, and the waist-to-hip ratio were all higher than in the patients with normal LDL (particle size > or = 25.5 nm), while the high-density lipoprotein cholesterol level was lower. However, there were no significant differences in BMI, BP, or insulin sensitivity in a euglycemic clamp study between the small-LDL and normal-LDL subgroups. CONCLUSIONS: Japanese men with glucose intolerance frequently have small LDL, and this abnormality is associated with other dyslipoproteinemias and increased waist-to-hip ratio.

Hypertension induced by adrenocortical dysfunction--hypertension in 17 alpha-hydroxylase deficiency and metopirone-induced hypertension.

Hypertension in 17 alpha-hydroxylase deficiency was studied by comparing it with hypertension in Cushing syndrome or that in primary aldosteronism. Furthermore, the role of endogenous increases of ACTH, deoxycorticosterone, and 18 alpha-hydroxy-deoxycorticosterone upon blood pressure was studied in rats by administerating metopirone. Hypertension in 17 alpha-hydroxylase deficiency was considered to be more similar to that in primary aldosteronism from the studies on renin components, pressor responses to angiotensin II and norepinephrine, and renin responses to stimulations. Plasma catecholamines were slightly decreased in 17 alpha-hydroxylase deficiency. The hypertension was alleviated by the administeration of dexamethasone in 2 of 3 patients with 17 alpha-hydroxylase deficiency. However, in the remaining one who had an accelerated hypertension and normal renin, the hypertension was not alleviated by dexamethasone. In the animal studies, hypertension induced by metopirone was accelerated by salt loading of uni-lateral nephrectomy plus salt loading. In those rats, plasma ACTH, and deoxycorticosterone were markedly increased.