An in vitro demonstration of CMOS-based optoelectronic neural interface device for optogenetics.

A CMOS-based neural interface device equipped with an integrated micro light source array for optogenetics was fabricated and demonstrated. A GaInN LED array formed on sapphire substrate was successfully assembled with a multifunctional CMOS image sensor that is capable of on-chip current injection. We demonstrated a functionality of light stimulation onto ChR2-expressed cells in an in vitro experiment. A ChR2-expressed cell were successfully stimulated with the light emitted from the fabricated device.

A CMOS-based on-chip neural interface device equipped with integrated LED array for optogenetics.

A novel CMOS-based neural interface device equipped with an integrated micro light source array was proposed and demonstrated. Target application of the device is optogenetics. GaInN LED array formed on sapphire substrate was successfully assembled with a multifunctional CMOS image sensor which is capable of injecting current via any of the pixel. We demonstrated addressable LED operation with the present device. The device has advantages such as simultaneous multi-site stimulation and on-chip optical imaging, that are not available with previously reported LED array device for optogenetics.

CMOS-based smart-electrode-type retinal stimulator with bullet-shaped bulk Pt electrodes.

A CMOS-based flexible retinal stimulator equipped with bullet-shaped bulk Pt electrodes was fabricated and demonstrated. We designed a new CMOS unit chip with an on-chip stimulator, single- and multi-site stimulation modes, and monitoring functions. We have developed a new structure and packaging process of flexible retinal stimulator with bullet-type bulk Pt electrode. We have confirmed the retinal stimulation functionality in an in vivo stimulation trial on rabbit's retina.

A CMOS-based multichip flexible retinal stimulator for simultaneous multi-site stimulation.

We developed a novel CMOS-based multichip flexible neural stimulator with on-chip stimulation generator. It enables simultaneous multi-site stimulation. We also propose a new type of multi-chip retinal stimulator with single electrode / unit chip configuration. We successfully performed simultaneous multi-site stimulation in an in vivo retinal stimulation experiment using a rabbit.

Development and in vivo Demonstration of CMOS-Based Multichip Retinal Stimulator With Simultaneous Multisite Stimulation Capability.

A complementary metal-oxide semiconductor (CMOS)-based multichip flexible neural stimulator for retinal prostheses was developed. The multichip retinal stimulator is capable of simultaneous multisite stimulation. An on-chip stimulation generator was implemented on the "unit chip," which is the core device of the multichip retinal stimulator. The performance of the CMOS circuitry was characterized. A new device structure and packaging process was developed. The in vivo retinal stimulation on a rabbit's retina was successfully performed and the multisite stimulation functionality was confirmed.

Light-controlled retinal stimulation on rabbit using CMOS-based flexible multi-chip stimulator.

We implemented a light-sensing function on CMOS-based multi-chip stimulator for retinal prosthesis. Using the light-sensing circuitry attached to each stimulation electrode, the flexible multi-chip stimulator is capable of image-based patterned stimulation. We verified the function of the light-controlled decision based on the light intensity measured just beside the stimulation site. We also experimentally demonstrated in vivo retinal stimulation on rabbit's retina with light-controlled decision. The result of the present work is a simplified demonstration for the concept of retinal prosthesis with on-site imaging.

Polarization-Analyzing CMOS Image Sensor With Monolithically Embedded Polarizer for Microchemistry Systems.

This paper proposes and demonstrates a polarization-analyzing CMOS sensor based on image sensor architecture. The sensor was designed targeting applications for chiral analysis in a microchemistry system. The sensor features a monolithically embedded polarizer. Embedded polarizers with different angles were implemented to realize a real-time absolute measurement of the incident polarization angle. Although the pixel-level performance was confirmed to be limited, estimation schemes based on the variation of the polarizer angle provided a promising performance for real-time polarization measurements. An estimation scheme using 180 pixels in a 1deg step provided an estimation accuracy of 0.04deg. Polarimetric measurements of chiral solutions were also successfully performed to demonstrate the applicability of the sensor to optical chiral analysis.

Ultrafast all-optical switching by cross-absorption modulation in silicon wire waveguides.

We describe the use of two-photon absorption in submicron silicon wire waveguides for all-optical switching by cross-absorption modulation. Optical pulses of 3.2 ps were successfully converted from high power pump to low power continuous-wave signal with a fast recovery time. High speed operation was based on the induced optical absorption from non-degenerate two-photon absorption inside the waveguides.

Nd1, a novel murine Kelch family protein, may play the role of a housekeeping gene.

The murine Nd1 gene encodes a novel Kelch family protein and expresses two forms of mRNA, long (Nd1-L) and short (Nd1-S), in various tissues. We characterized the genomic organization of the Nd1 gene, and found that Nd1-L and Nd1-S consist of 16 and nine exons respectively, and that exons I-VIII are shared between them. Three transcription initiation sites were identified in the 5'-flanking region and the most 3' side (+1) is likely to be a major one. Promoter analysis revealed that the region between positions -247 and -86 was sufficient for expression, and that two Sp1-binding sites and one NF-kappaB-binding site in the region were critical for promoter activity. Furthermore, the promoter region lacks a TATA and a CAAT box and has a highly GC-rich region with two important Sp1-binding sites. These characteristics of the Nd1 gene promoter are similar to the properties of housekeeping genes.

An enhancer element for expression of the Ncx (Enx, Hox11L1) gene in neural crest-derived cells.

The murine Ncx (Enx, Hox11L1) gene is specifically expressed in a neuronal subset of neural crest-derived tissues. In attempts to elucidate the regulatory DNA element of the tissue-specific expression, we sequenced the 5'-flanking region of the Ncx gene. The transcriptional initiation site was determined at 297 nucleotides (-297) upstream from the ATG start codon (+1). A retinoic acid response element was located on the region between -1163 and -1150. Transient transfection assays with the 5'-flanking sequences fused to the luciferase gene showed that the region between -1387 and -1368 was crucial for the tissue-specific enhancer activity. Furthermore, nuclear proteins extracted from neural crest-derived cells such as murine and human neuroblastoma cells bind to the DNA region between -1387 and -1368. This DNA element was also conserved in the 5'-flanking region of the human NCX gene. Our observations strongly suggest that the DNA element (between -1387 and -1368) contributes to tissue-specific expression of the Ncx gene in murine and human species.

Cytotoxic scalarane sesterterpenes from a sponge, Hyrtios erecta.

Novel scalarane sesterterpenes (1-4) were isolated from a sponge, Hyrtios erecta (order Dictyoceratida). They were characterized by means of spectral analyses, X-ray crystallography, and chemical reactions. Compound 1 showed potent in vitro and in vivo antitumor activities. In addition, the structure-activity relationship was also discussed using computer-assisted structure matching of 1 and aragusterols.

Lipid emulsions of palmitoylrhizoxin: effects of composition on lipolysis and biodistribution.

Four types of lipid emulsion for highly lipophilic antitumour agent RS-1541 (13-O-palmitoylrhizoxin) with mean particle diameters of 200-260 nm were prepared using soybean oil (SOY) or dioctanoyldecanoylglycerol (ODO) for the oil phase and lecithin (LEC) or polyoxyethylene-(60)-hydrogenated castor oil (HCO-60) for surfactants. The lipolysis rate of HCO-60-emulsified emulsions by lipoprotein lipase was much slower than that of LEC-emulsified emulsions. Particle sizes of emulsions incubated in plasma with the lipase for six hours were 75%, 79%, 101%, and 93% of initial values for SOY/LEC, ODO/LEC, SOY/HCO-60, and ODO/HCO-60 emulsions, respectively, showing an apparent size decrease for LEC-emulsified emulsions. In rats, uptake clearance values of SOY/LEC and ODO/LEC emulsions of RS-1541 in the reticuloendothelial system (RES) were 81.2 and 135.3 mL h(-1), respectively, and AUC values were 4.0 and 1.3 microg h mL(-1), respectively. In contrast, RES uptake clearances of HCO-60 emulsions of RS-1541 were considerably lower (4.2 mL h(-1) for SOY/HCO-60; 2.2 mL h(-1) for ODO/HCO-60), resulting in high AUC values (35.4 microg h mL(-1) for SOY/ HCO-60; 63.9 microg h mL(-1) for ODO/HCO-60). The concentrations of RS-1541 in tumour tissues after an intravenous administration of ODO/HCO-60 emulsions of RS-1541 to mice bearing solid tumour M5076 sarcoma were about ten times higher than those after the administration of SOY/LEC emulsions. These results indicate that HCO-60 emulsions, compared with conventional LEC emulsions, are more stable to lipoprotein lipase and show low uptakes by RES organs, long circulations in the plasma, and high distributions in tumours. Thus, these sterically stabilized emulsions could show potential as effective carriers for highly lipophilic antitumour agents to enhance the drug delivery in tumours.

Enhanced tumor delivery and antitumor activity of palmitoyl rhizoxin using stable lipid emulsions in mice.

PURPOSE: A highly lipophilic antitumor agent, 13-O-palmitoyl-rhizoxin (RS-1541), was incorporated into lipid emulsions of various sizes consisting of triglyceride ODO and surfactant HCO-60. Pharmacokinetics, toxicities, and antitumor activities were evaluated after intravenous administration to mice bearing subcutaneously inoculated M5076 sarcoma cells. METHODS: The levels of RS-1541 in the plasma and tissues including tumor, were determined by HPLC. The maximum tolerated dose (MTD) was estimated by toxic death and change in body weight. The decrease in tumor diameter was measured for antitumor activity. RESULTS: There existed large variations in pharmacokinetics of RS-1541, depending on the size of emulsion particles. Compared with a colloidal solution (reference solution), the small (110nm) and medium (230nm) size emulsions showed high concentrations of RS-1541 in the tumor, while the large emulsions (350nm-630nm) exhibited low concentrations. The MTD of RS-1541 was reduced, when incorporated in the emulsions larger than 220nm in size. At MTD, each size of emulsions (70nm-380nm) effectively retarded the tumor growth and increased survival time. The maximum effect was achieved for the 220 nm emulsions. CONCLUSIONS: When particle size is properly selected, these emulsions could be promising and effective as an injectable carrier for lipophilic antitumor agents in order to enhance the tumor delivery and efficacies while reducing toxicities.

Plasma lipoproteins as targeting carriers to tumour tissues after administration of a lipophilic agent to mice.

We synthesized 14C-warfarin hexadecyl ether (14C-WHE) by addition of a palmityl moiety to the hydroxyl group at the 4-position of 14C-warfarin, a compound known to bind to serum albumin. 14C-WHE preferentially bound to the lipoproteins, low-density lipoprotein (LDL) and high-density lipoprotein (HDL), in mouse plasma both in vitro and in vivo. 14C-Warfarin mainly concentrated in the liver immediately after intravenous administration to mice bearing M5076 sarcoma, and was found at only low concentrations in other tissues including the tumour. 14C-WHE highly distributed to the tumour, adrenal, and spleen, as well as the liver. These tissues coincided with those in which human 125I-LDL was vigorously incorporated. The results indicate that chemical modification of an agent, giving it high lipophilicity, will enable it to bind to lipoproteins after intravenous administration. These modifications raise the possibility of lipoproteins as endogenous targeting carriers into tumour cells, which have high LDL-receptor activity.

Tumor selective effect of RS-1541 (palmitoyl-rhizoxin) in M5076 sarcoma and host tissues in vivo.

RS-1541 is a 13-O-palmitoyl derivative of rhizoxin, an inhibitor of tubulin polymerization. After intravenous administration of RS-1541 to mice bearing M5076 sarcoma, the maximal inhibitory effect of RS-1541 on DNA synthesis in the tumor was observed 24 h after administration, in agreement with the Cmax of rhizoxin produced from RS-1541, but not with the Cmax of RS-1541. The inhibitory effect after RS-1541 was much higher than that after rhizoxin itself. In the spleen, thymus and bone marrow, DNA synthesis was strongly inhibited by rhizoxin but not by RS-1541. After administration of RS-1541, no significant amounts of rhizoxin were detected in the tissues, except for the tumor. In acute toxicity tests, RS-1541 appeared to be less toxic than rhizoxin. These results indicate that RS-1541 possesses a high tumor-selective effect compared with rhizoxin, because of the selective production of rhizoxin in the tumor after administration of RS-1541.

Contribution of serum lipoproteins as carriers of antitumour agent RS-1541 (palmitoyl rhizoxin) in mice.

The tumour uptake as well as the anti-tumour activity of RS-1541 (palmitoyl rhizoxin), a potent antineoplastic agent, were investigated in mice bearing M5076 sarcoma. After intravenous administration, 14C-RS-1541 preferentially bound to the lipoproteins, to which 14C-rhizoxin did not bind. 14C-RS-1541 showed persisting high concentrations of radioactivity in the plasma (T 1/2 alpha, 4.9 h). The uptake of radioactivity by the tumour was second to those by the liver and spleen, and several times greater than those by the other tissues. Selective and sustained uptake by the tumour was also demonstrated by whole-body autoradiography. A considerable amount of rhizoxin was detected only in the tumour after administration of 14C-RS-1541, and the area under the tissue-concentration-time curve (AUCt) and the mean residence time (MRT) of rhizoxin in the tumour were much higher than those after administration of 14C-rhizoxin itself. The rhizoxin formation in the tumour was significantly reduced by chloroquine, a lysosomal enzyme inhibitor. RS-1541 showed a higher therapeutic activity than rhizoxin. At a 4 mg kg-1 dose, the maximum growth inhibition was 92% for RS-1541 and 41% for rhizoxin. These results indicate that RS-1541, but not rhizoxin, is taken up by the tumour via endocytosis, most likely via the low-density-lipoprotein receptor, after binding to lipoproteins. Thus, RS-1541 was considered to exhibit sustained high concentration in tumours and potent anti-tumour activity.

A case of pseudo-Bartter's syndrome associated with hypergastrinemia, thrombocytosis and increased serum thyroxine-binding globulin.

A housewife, 40 years of age, was admitted with dysesthesia of the extremities, muscle weakness, and attacks of adynamia and thirst. She had been taking a laxative for more than 20 years. On physical examination, blood pressure was 94/56 mmHg. Laboratory tests revealed thrombocytosis, low serum K and marked increases in both plasma renin activity and serum aldosterone. Serum TBG was increased. Serum gastrin was also markedly increased and could not be enhanced by exogenous secretin. Both angiotensin 11 loading test and noradrenalin loading test failed to increase blood pressure. Ammonium chloride loading to examine the disturbance of urinary acidification was abnormal in the short term test and borderline in the long term test. Following a diagnosis of pseudo-Bartter's syndrome induced by long term intake of laxative and repeated diarrhea, the administration of laxative was interrupted and potassium, indomethacin and spironolactone were administered. However, serum K remained low. Hypergastrinemia, thrombocytosis and a high serum TBG level also persisted, the causes of which remain unknown. This is the first reported case of pseudo-Bartter's syndrome associated with hypergastrinemia, thrombocytosis and increased serum TBG.

Different inhibitory actions of immunomodulating agents and immunosuppressive agents on bone resorption of mouse calvaria.

In this study, we have investigated the in vitro effects of the immunomodulators lobenzarit and traxanox and a newly synthesized immunosuppressant, mizoribine, as well as cyclosporin A, on bone resorption using neonatal mouse calvariae labelled with 45Ca. As stimulators of bone resorption, bovine parathyroid hormone (PTH), lipopolysaccharide (LPS), interleukin 1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) were used. Lobenzarit, traxanox, mizoribine and cyclosporin A inhibited or tended to inhibit bone resorption stimulated by PTH, LPS, IL-1 beta or TNF-alpha in a dose-dependent manner. Basal bone resorption was inhibited by immunosuppressant cyclosporin A or mizoribine, while immunomodulators lobenzarit and traxanox failed to inhibit basal bone resorption. Removal of lobenzarit from the culture medium resulted in the recovery of bone resorptive activity. These results suggest that the inhibitory effect of immunomodulators on bone resorption is reversible and nonselective. Also, it raises the possibility that immunomodulators and immunosuppressants may affect bone resorption by different mechanisms.