Mutations in the GJB2 gene (connexin 26) are the major cause of autosomal recessive non-syndromic hearing impairment in many populations. In contrast to the volume of information regarding the involvement of GJB2 mutations in hearing impairment in populations of European ancestry, less is known regarding other ethnic groups. In this study, we analyzed the GJB2 gene for mutations in 1227 hearing-impaired Japanese individuals. This revealed a unique spectrum of GJB2 mutations, different from that found in the Caucasian population. The most frequent mutation in Japanese, 235delC, has never been reported in Caucasians. To investigate a possible founder effect for the 235delC mutation, we analyzed single nucleotide polymorphisms in the vicinity of the GJB2 gene. Results were consistent with inheritance of the 235delC mutation from a common ancestor. The results of this study have important implications for genetic diagnostic testing for deafness in the Japanese population.

The light-emitting device is the primary device for current light sources. In principle, conventional light-emitting devices need heterostructures and/or intentional carrier doping to form a p-n junction. This junction formation is, however, very difficult to achieve for most emerging semiconductors, and the fabrication of light-emitting devices is invariably a significant challenge. This study proposes a versatile and simple approach to realize light-emitting devices. This proposed device requires only a semiconducting film with two electrodes that are covered with an electrolyte. This unique structure achieves light emission at a voltage slightly larger than the bandgap energy of materials. This study applies this concept to emerging direct bandgap semiconductors, such as transition metal dichalcogenide monolayers and zinc oxide single crystals. These devices generate obvious light emission and provide sufficient evidence of the formation of a dynamic p-i-n junction or tunneling junction, presenting a versatile technique to develop optoelectronic devices.

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Transition metal dichalcogenide (TMDC) monolayers have attracted much attention due to their strong light absorption and excellent electronic properties. These advantages make this type of two-dimensional crystal a promising one for optoelectronic device applications. In the case of photoelectric conversion devices such as photodetectors and photovoltaic cells, p-n junctions are one of the most important devices. Here, we demonstrate photodetection with WSe 2 monolayer films. We prepare the electrolyte-gated ambipolar transistors and electrostatic p-n junctions are formed by the electrolyte-gating technique at 270 K. These p-n junctions are cooled down to fix the ion motion (and p-n junctions) and we observed the reasonable photocurrent spectra without the external bias, indicating the formation of p-n junctions. Very interestingly, two-terminal devices exhibit higher photoresponsivity than that of three-terminal ones, suggesting the formation of highly balanced anion and cation layers. The maximum photoresponsivity reaches 5 mA/W in resonance with the first excitonic peak. Our technique provides important evidence for optoelectronics in atomically thin crystals.

SUMMARY The effects of endogenous epinephrine (E), released by glucagon injection, and exogenously infused E on plasma norepinephrine (NE) and cardiovascular responses before and after [3-blockade were studied in patients with essential hypertension and in age-matched normotensive controls. The resting plasma NE and E levels were significantly higher in the borderline hypertensive subjects (NE: 251 ± 21 pg/ml [SEM], p < 0.005; E: 57 ± 5, p < 0.05, n = 18) than in controls (NE: 129 ± 12; E: 39 ± 5, n = 18). An intravenous injection of glucagon (1.0 nig) induced a transient rise of both plasma catecholamine levels and blood pressure in every subject studied. Plasma E levels rose transiently and returned to the basal levels by 20 minutes after the injection, whereas plasma NE levels showed a more prolonged rise over 20 minutes. ^-Blockade with propranolol did not affect the plasma E response to glucagon, but inhibited the prolonged rise of plasma NE levels. An intravenous infusion of exogenous E (1.25-1.50 ^ig/min) for 30 minutes caused an apparent rise of both plasma NE levels and blood pressure, which lasted more than 60 minutes after stopping the E infusion. Propranolol did not affect the time course of plasma E but again inhibited the prolonged rise of both plasma NE levels and blood pressure. No significant differences could be observed in the cardiovascular or plasma NE responses to glucagon or to E infusion between normal and hypertensive subjects. These findings lend support to the view that plasma E can act physiologically as a sustained stimulator of presynaptic /3-adrenergic receptors, which leads to an enhanced NE release from peripheral sympathetic nerve terminals and a rise of blood pressure in humans. (Hypertension 7: 187-195, 1985) KEY WORDS • sympathoadrenal activity • glucagon • plasma catecholamines presynaptic /3-adrenergic receptor * propranolol

CRH, GH-releasing hormone (GHRH), somatostatin (SRIH), and peptide histidine methionine (PHM) were measured by RIA in extracts of normal adrenal glands and in extracts from adrenal and extraadrenal pheochromocytomas. In normal adrenal glands, immunoreactive (IR) CRH, IR-SRIH, and IR-PHM were detectable, while IR-GHRH was undetectable. In all 11 cases of adrenal pheochromocytomas, the tumors contained 2 or more of these four IR-peptides. In particular, IR-CRH was found in 73% (n = 8) of adrenal pheochromocytomas, IR-GHRH in 91% (n = 10), IR-SRIH in 91% (n = 10), and IR-PHM in 82% (n = 9) of adrenal pheochromocytomas. There was no significant correlation among the concentration of these peptides in each tumor, i.e. the concentrations of the IR-peptides were independent of each other. In contrast to the adrenal pheochromocytomas, none of these 4 IR-peptides was detectable in 5 extraadrenal pheochromocytomas. Gel filtration of pooled extracts from adrenal pheochromocytomas showed that the major component of the IR-CRH, IR-GHRH, IR-SRIH, and IR-PHM eluted in the position of their synthetic counterparts. Our results suggest that 1) the normal adrenal gland contains IR-CRH, IR-SRIH, and IR-PHM, but not IR-GHRH; 2) all of the adrenal pheochromocytomas we examined contained a number of hypothalamic releasing or inhibiting hormones; 3) their tissue concentrations were independent of each other; and 4) all of the extraadrenal pheochromocytomas we examined contained no such IR-peptides. The presence of hypothalamic hormones in adrenal pheochromocytomas and their absence in extraadrenal pheochromocytomas may be due to the differences in the chromaffin cells of their origin. Our data may be helpful in the differential diagnosis between adrenal and extraadrenal pheochromocytomas.

In this general method for measuring the concentrations of neurotransmitters in body fluids by "high performance" liquid chromatography (HPLC), the procedures for extracting different biogenic amines from body fluids vary, but the basic chromatographic conditions are the same for all. We use citric/formic acid buffer as the mobile phase, a C18 column, and an electrochemical detector. Specificity is better than in previously reported methods. Because of its excellent cost efficiency, we consider this to be the method of choice for quantifying biogenic amines.

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