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.     

Analysis of XANES for identification of highly dispersed transition metal oxides on supports

XANES of vanadium and niobium oxide on silica or alumina have been analyzed quantitatively by a deconvolution technique. Based on the results for reference compounds, local structures of supported vanadium and niobium species were identified. The composition was estimated from difference spectra for the samples which consisted of two kinds of species.     

Microscale analysis of glycosphingolipids by TLC blotting/secondary ion mass spectrometry: a novel blood group A-active glycosphingolipid and changes in glycosphingolipid expression in rat mammary tumour cells with different metastatic potentials

The glycosphingolipid compositions of rat mammary tumour cell lines with different metastatic potentials for the lung [a parental tumour cell line (MTC) and its subclones MTLn2 (a non metastatic subclone) and MTLn3 (a subclone with high metastatic potential to the lung)] were studied using a newly developed TLC blotting/secondary ion mass spectrometry system and crude glycosphingolipids obtained from 0.5-1 x 10(7) cells of each cell line. GM3 and GM2 were the major components of the MTC cell line, but they were very minor components in the MTLn2 and MTLn3 cell lines, GDla being the major ganglioside HexNAc-fucosyl-GMla was found in the MTLn2 cells by the TLC blotting/SIMS method, and the terminal sugar linkage was shown to be a blood group A-type structure by immunostaining. These findings suggest that the ganglioside is a novel type of blood group A-active ganglioside, GalNAc alpha 1-3(fuc alpha 1 -2)GMla. No blood group A-active lipid was present in MTLn3 cells, whereas Hex-GMla and neutral glycosphingolipids with more than 5 sugar residues were.     

Ligation of medically refracted patent ductus arteriosus (PDA) in an extremely low body weight premature infant

Medically refracted patent ductus arteriosus (PDA) in an extremely low birth weight (ELBW) preterm (gestation 24 weeks 2 days) infant was successfully ligated under general anesthesia in the neonatal intensive care unit (NICU). Pharmacological agents are more effective to close PDA in preterm infants than in full-term infants, although within 48 h three doses of indomethacin were not sufficient to close PDA in this case. At the age of 69 h the infant developed severe symptoms including bradycardia, systemic hypotension, pulmonary hypertension, diastolic steal (reverse distal aorta flow velocity), and anuria. A PDA ligation was thus performed surgically at 72 h of age. General anesthesia and surgical stress were tolerated by this 531 g infant. Postoperatively all symptoms improved dramatically and the general conditions were stable. On the 38th day the endotracheal tube was extubated and on the 50th day nasogastric milk feeding was started. The oxygen supply was weaned on the 78th day. Growth and development until 6 months were within the normal range of very low birth weight infants. A surgical ligation as early as possible in medically refracted PDA in an ELBW infant is thus considered to be a safe and effective treatment. It prevents the development of further complications of cardiopulmonary vascular problems. Color Doppler echocardiography can reliably measure the PDA size, flow velocity, and hemodynamic changes of persistent PDA, even in tiny infants.     

Detection of enzymatically generated hydrogen peroxide by metal-based fluorescent probe

We developed a metal-based fluorescent probe for H(2)O(2) called MBFh1, which has an iron complex as a reaction site for H(2)O(2) and a 3,7-dihydroxyphenoxazine derivative as the fluorescent reporter unit. The iron complex reacts quickly with H(2)O(2) to form oxidants, and then the oxidants convert the closely appended nonfluorescent 3,7-dihydroxyphenoxazine moiety to resorufin in an intramolecular fashion. The quick response to H(2)O(2) allows us to plot the enzymatic evolution of H(2)O(2). A combination of N-acetyl-3,7-dihydroxyphenoxazine and horseradish peroxidase has been frequently used to detect enzymatically generated H(2)O(2), but this method has interference with phenol derivatives. The use of MBFh1 overcomes this drawback.     

Quantification of sphingosine derivatives in human platelets: inducible formation of free sphingosine

OBJECTIVE: This study aimed to investigate the incidence of cystoid macular edema and anterior uveitis associated with the use of latanoprost. DESIGN: A retrospective review of patients treated with latanoprost in the authors' practice between September 1, 1996, and August 1, 1997, was performed. PARTICIPANTS: Ninety-four patients and 163 eyes were studied. INTERVENTION: Patients presenting with signs and symptoms of ocular inflammation while receiving latanoprost were noted, and their response to the discontinuation of the drug was recorded. MAIN OUTCOME MEASURES: The presence and degree of anterior uveitis and cystoid macular edema were measured. RESULTS: Six (6.4%) of 94 patients (8 [4.9%] of 163 eyes) had anterior uveitis develop, and 2 (2.1%) of 94 patients (2 [1.2%] of 163 eyes) had cystoid macular edema develop while being treated with latanoprost. CONCLUSION: Although latanoprost is an effective ocular-hypotensive agent, the authors' experience with the drug has shown a significant incidence of anterior uveitis and cystoid macular edema. To the authors' knowledge, this is the first study to report the incidence of both cystoid macular edema and anterior uveitis associated with latanoprost therapy. Treating physicians should be aware of these potential complicating side effects of latanoprost.     

Newly Developed Thyristor Chopper Equipment for Electric Railcars

In the chopper control system for electric railcars, it is effective to adopt high operational frequency of the chopper for achievement of the following: 1) decrease of higher harmonic current induced in the trolley wire, 2) reduction of weight for reactors and capacitors in the traction circuit, and 3) improvement of control response. Through development of reverse-conducting thyristors with very short turn-off time and a repulsion type two-phase chopper, we finally realized production of a new standard high-frequency chopper equipment with regenerative braking for 1500-V dc railcars. Technical achievements mentioned previously were completely realized as a result of adoption of high frequency, 660 Hz, in the equipment. The newly developed standard high-frequency chopper equipment for 30 cars were delivered to the Chiyoda Line of Teito Rapid Transit Authority in Tokyo, and they have been operated satisfactorily in revenue service since March 1971. This paper also describes: 1) the chopper circuit using fast-switching reverse-conducting thyristors and series saturable reactors, 2) analysis of commutation circuit and methods of suppressing reapplied forward voltage increasing rate (dv/dt) and shortening commutation period, 3) the composition of the traction circuit including the protection system, such as protection for overvoltage at the regenerative braking, and 4) test results on the Chiyoda Line of Teito Rapid Transit Authority.     

Soft materials with graphitic nanostructures

This review article focuses on our recent studies on novel soft materials consisting of carbon nanotubes. Single-walled carbon nanotubes, when suspended in imidazolium ion-based ionic liquids and ground in an agate mortar, form physical gels (bucky gels), where heavily entangled bundles of carbon nanotubes are exfoliated to give highly dispersed, much finer bundles. By using bucky gels, the first printable actuators that operate in air for a long time without any external electrolyte are developed. Furthermore, the use of polymerizable ionic liquids as the gelling media results in the formation of electroconductive polymer/nanotube composites with enhanced mechanical properties. The article also highlights a new family of nanotubular graphite, via self-assembly of amphiphilic hexabenzocoronene (HBC) derivatives. The nanotubes consist of a graphitic wall composed of a great number of pi-stacked HBC units and are electroconductive upon oxidation. The use of amphiphilic HBCs with functional groups results in the formation of nanotubes with various interesting properties.