Transporters in the neurohypophysial neuroendocrine system, with special reference to vesicular glutamate transporters (BNPI and DNPI): a review.

Recent advances in gene technology have helped to identify novel proteins and allowed study of their distribution and functions in the mammalian brain. One class of these proteins is that of transporters, which exist in plasma and organellar membranes of neurons and other cells to move substances selectively across membranes. These transporters can be categorized further into subclasses by their structural property, substrate selectivity, and site of action. Some of them have been identified in the hypothalamus, which is the only brain site where a neural signal is converted to a humoral one, namely, a hormone for a target organ. This unique neural mechanism has long attracted attention as the neuroendocrine system, part of which has been extensively studied as the hypothalamic-neurohypophysial system involved in secretion of vasopressin and oxytocin. However, transporters in this system have been less well studied. A morphological examination of novel transporters would give us cues to a better understanding of the neuronal organization and function of the system. In this review, we first summarize recent findings on expression of transporter gene and immunoreactivity in the hypothalamus. In the second part, we explain our observations on two vesicular glutamate (inorganic phosphate) transporters (BNPI and DNPI) in the supraoptic and paraventricular nuclei and neurohypophysis. Further study of these and other transporters will provide a basis on which to reevaluate the organization and function of the hypothalamic-neurohypophysial system.     

Preparation of gold nanoparticles (GNP) aqueous suspensions by a new method involving Tiron

A new method is proposed to produce gold nanoparticles (GNP) by in situ reduction of a gold salt dissolved in water. The reducing agent used is Tiron instead of the citrate anion most often mentioned in literature. The influence of various parameters has been investigated, such as the content of Tiron with respect to that of the precursor of gold HAuCl₄, or the initial pH of the solution after mixing of reactants. It is shown that Tiron also exerts a positive influence as a dispersant, which impedes agglomeration of gold nanoparticles. The typical average size of GNP synthesized in the present work is close to 7 nm.     

Automated low-power technique exploiting multiple supply voltagesapplied to a media processor

This paper describes an automated design technique to reduce power by making use of two supply voltages. The technique consists of structure synthesis, placement, and routing. The structure synthesizer clusters the gates off the critical paths so as to supply the reduced voltage to save power. The placement and routing tool assigns either the reduced voltage or the unreduced one to each row so as to minimize the area overhead. The reduced supply, voltage is also exploited in a clock tree to reduce power. Combining these techniques together, we applied it to a media processor chip. The combined technique reduced the power by 47% in random-logic modules and by 73% in the clock tree, while keeping the performance     

Elevated serum lipoprotein (a) levels associated with ulcerative colitis in a young Japanese patient

Thromboembolism has been shown to play a role in the pathogenesis of inflammatory bowel disease (IBD). A possibility exists that lipoprotein (a) [Lp(a)], a newly-discovered prothrombotic factor, also participates in the development of at least some cases of IBD. Marked elevation of serum Lp(a) levels was observed in a young patient with ulcerative colitis. A biopsy specimen of the rectal mucosa showed findings compatible with ulcerative colitis, as well as small vessel thrombus occurring within the muscularis mucosa in the rectum. Serum Lp(a) levels were markedly elevated on admission (71 mg/dl), with a gradual decrease to 46 mg/dl on discharge. Moreover, serum Lp(a) levels decreased in parallel with clinical improvement. In the quiescent clinical stage, no small vessel thrombus was observed in the mucosa on follow-up colonoscopy. The association between IBD and hyper-Lp(a)-emia would be presumable but it has been, to our knowledge, previously unreported. The case reported here would be the first young patient, suggesting the presence of hyper-Lp(a)-emia and small vessel thrombus formation occurring in association with the development of ulcerative colitis.     

Local Epidermal Endocrine Estrogen Protects Human Melanocytes against Oxidative Stress,a Novel Insight into Vitiligo Pathology

As the outermost barrier of the body, skin is a major target of oxidative stress. In the brain, estrogen has been reported synthesized locally and protects neurons from oxidative stress. Here, we explored whether estrogen is also locally synthesized in the skin to protect from oxidative stress and whether aberrant local estrogen synthesis is involved in skin disorders. Enzymes and estrogen receptor expression in skin cells were examined first by quantitative real-time PCR and Western blot analyses. Interestingly, the estrogen synthesis enzyme was mainly localized in epidermal keratinocytes and estrogen receptors were mainly expressed in melanocytes among 13 kinds of cultured human skin cells. The most abundant estrogen synthesis enzyme expressed in the epidermis was 17β-hydroxysteroid dehydrogenase 1 (HSD17β1) localized in keratinocytes, and the most dominant estrogen receptor expressed in the epidermis was G protein-coupled estrogen receptor 1 (GPER1) in melanocytes. To investigate whether keratinocyte-derived estradiol could protect melanocytes from oxidative stress, cultured human primary epidermal melanocytes (HEMn-MPs) were treated with H₂O₂ in the presence or absence of 17β estradiol or co-cultured with HSD17β1 siRNA-transfected keratinocytes. Keratinocyte-derived estradiol exhibited protective effects against H₂O₂-induced cell death. Further, reduced expression of HSD17β1 in the epidermis of skin from vitiligo patients was observed compared to the skin from healthy donors or in the normal portions of the skin in vitiligo patients. Our results suggest a possible new target for interventions that may be used in combination with current therapies for patients with vitiligo.     

Multi-dimensional transient mathematical simulator of blast furnace process based on multi-fluid and kinetic theories

The ironmaking blast furnace is regarded as one of the biggest and most complex industrial reactors, because it includes various materials like gas, lump granular materials, liquids and powders and more than 30 major reactions and phase changes in a single reaction vessel. The mathematical simulator of this process developed in this study used the multi-fluid treatment as its framework, since the motions of these materials were governed by different flow mechanisms. The rates of the interactions among the phases and the chemical reactions were evaluated based on kinetic theories. The model successfully reproduced the fields of velocity, temperature and reaction in the furnace and its validity was confirmed. The simulator was also applied to a novel operation, namely the top gas recycling combined with the carbon-composite iron-ore charging and the waste plastics injection, and the advantages in furnace efficiency and environmental load were quantitatively indicated.     

Formation of Small-Sized CdSxSe1-x Crystals in Sol-Gel-Derived SiO2 Glasses

Silica glasses doped with small-sized CdS_x-Se_1-x crystals were prepared by the sol-gel method. Gels synthesized by the hydrolysis of Si(OC₂H₅)₄, in the presence of CdSeO₄ with NH₄SCN dissolved in HNO₃ or NH₄OH, were heated in H₂-N₂ atmosphere. The pH value of solutions for CdSeO⁴ and NH⁴SCN primarily determined the fraction of anions in CdS^xSe^1-x crystals. The anion content in crystals was dependent on the pH value of the solvent and/or heat-treatment temperature, and the sulfur fraction changed from 0.1 to 0.6. The optical absorption spectra were red-shifted as the selenium content and the crystal size increased, and the emission spectra showed a sharp band near the absorption edge position and a broad tail extending into the long wavelength. The optical band gap energies increased reciprocally proportional to the square of the crystal size.     

Dehydration of Gels and Glasses in the Systems B2 O3-SiO2 and ZrO2-SiO2 Prepared by the Sol-Gel Process from Metal Alkoxides

Dehydration of gels prepared by the sol-gel process from metal alkoxides in the systems B₂O₃-SiO₂ and ZrO₂-SiO₂ was determined by measuring the shrinkage of the gel on heating. Dehydration was enhanced with increased ZrO₂ content, whereas it decreased with B₂O₃ content. Diffusion of water was also measured in the nonporous glasses obtained by heating the gels. The diffusion rate was independent of the composition of the glass.