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1.
Article in English | MEDLINE | ID: mdl-24109808

ABSTRACT

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.


Subject(s)
Electronics/instrumentation , Metals/chemistry , Neurons/physiology , Optogenetics/instrumentation , Oxides/chemistry , Semiconductors , Animals , Cell Line, Tumor , Channelrhodopsins , Equipment Design , Ion Channel Gating/radiation effects , Light , Mice , Neurons/radiation effects
2.
Article in English | MEDLINE | ID: mdl-23367087

ABSTRACT

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.


Subject(s)
Lighting/instrumentation , Neurons/physiology , Optogenetics/instrumentation , Photic Stimulation/instrumentation , Semiconductors , Signal Processing, Computer-Assisted/instrumentation , Voltage-Sensitive Dye Imaging/instrumentation , Equipment Design , Equipment Failure Analysis , Systems Integration
3.
Article in English | MEDLINE | ID: mdl-22255884

ABSTRACT

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.


Subject(s)
Electric Stimulation Therapy/instrumentation , Electrodes, Implanted , Platinum/chemistry , Signal Processing, Computer-Assisted/instrumentation , Visual Prosthesis , Animals , Computer Simulation , Electrodes , Equipment Design , Models, Anatomic , Rabbits , Retina/pathology , Retina/physiology
4.
Article in English | MEDLINE | ID: mdl-21096930

ABSTRACT

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.


Subject(s)
Electric Stimulation/instrumentation , Metals/chemistry , Oxides/chemistry , Pliability , Semiconductors , Animals , Buffers , Electricity , Evoked Potentials, Visual/physiology , Rabbits , Retina/physiology
5.
IEEE Trans Biomed Circuits Syst ; 4(6): 445-53, 2010 Dec.
Article in English | MEDLINE | ID: mdl-23853382

ABSTRACT

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.

6.
Article in English | MEDLINE | ID: mdl-19964235

ABSTRACT

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.


Subject(s)
Electric Stimulation Therapy/instrumentation , Electrodes, Implanted , Image Interpretation, Computer-Assisted/instrumentation , Photic Stimulation/instrumentation , Prostheses and Implants , Retina/physiology , Signal Processing, Computer-Assisted/instrumentation , Equipment Design , Equipment Failure Analysis , Light , Semiconductors
7.
IEEE Trans Biomed Circuits Syst ; 3(5): 259-66, 2009 Oct.
Article in English | MEDLINE | ID: mdl-23853264

ABSTRACT

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.

8.
Article in English | MEDLINE | ID: mdl-19163641

ABSTRACT

Multi-finger structure was proposed to improve flexibility of the CMOS LSI-based multi-chip retinal stimulator. A dual-finger retinal stimulator was fabricated and its functionality was demonstrated in retinal stimulation experiments on rabbit's retina, We also proposed an idea of pulsed-powering operation scheme for the multi-chip flexible retinal stimulator. We compared the pulsed-powering scheme with conventional one in a simulation, and show that the pulsed-powering can be an alternative operation scheme for the neural stimulator that provides an improved safety to the biological tissue.


Subject(s)
Electric Stimulation Therapy/instrumentation , Electric Stimulation/instrumentation , Evoked Potentials, Visual/physiology , Retina/physiology , Therapy, Computer-Assisted/instrumentation , Visual Cortex/physiology , Algorithms , Animals , Differential Threshold , Electric Stimulation/methods , Electric Stimulation Therapy/methods , Equipment Design , Prostheses and Implants , Rabbits , Retina/anatomy & histology , Semiconductors , Signal Processing, Computer-Assisted/instrumentation , Software , Therapy, Computer-Assisted/methods
9.
Article in English | MEDLINE | ID: mdl-18003329

ABSTRACT

We have performed in vivo electric stimulation experiments on rabbit retina to demonstrate feasibility of CMOS LSI-based multi-chip flexible neural stimulator for retinal prosthesis. We have developed new packaging structure with an improved flexibility and device control system which totally controls the LSI-based multi-chip stimulator, counter electrode, and stimulation generator. We have implanted the fabricated multi-chip stimulator into sclera pocket for STS (Suprachoroidal Transretinal Stimulation) configuration. We successfully obtained EEP (Electrically Evoked Potential) on visual cortex evoked by the multi-chip stimulator.


Subject(s)
Electric Stimulation Therapy/instrumentation , Electric Stimulation/instrumentation , Evoked Potentials, Visual/physiology , Prostheses and Implants , Retinal Ganglion Cells/physiology , Therapy, Computer-Assisted/instrumentation , Visual Cortex/physiology , Animals , Differential Threshold , Electric Stimulation/methods , Electric Stimulation Therapy/methods , Equipment Design , Equipment Failure Analysis , Rabbits , Reference Values , Semiconductors , Signal Processing, Computer-Assisted/instrumentation , Therapy, Computer-Assisted/methods
10.
J Neural Eng ; 4(1): S85-91, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17325420

ABSTRACT

This paper describes the technological developments underlying the realization of a reliable and reproducible microchip-based stimulator with a large number of stimulus electrodes. A microchip-based stimulator with over 500 electrodes for suprachoroidal transretinal stimulation (STS) is proposed in this paper, and an example is presented. To enhance reliability and reproducibility for such a large array, we introduce a flip-chip bonding technique and place microchips on the reverse side of a substrate. A square microchip of size 600 microm was fabricated using 0.35 microm standard CMOS process technology. Twelve microchips were flip-chip bonded on a polyimide substrate through Au bumps. To evaluate the feasibility of the proposed device, we successfully fabricated a stimulator with 12 microchips and 118 electrodes made of Pt/Au bumps, and demonstrated their operation in a saline solution for 2 weeks. Also, to evaluate the device operation in vivo, a stimulator with one active IrO(x) electrode was implanted into the scleral pocket of a rabbit and electrical evoked potential (EEP) signals with a threshold of 100 microA were obtained. We also fabricated a simulator with 64 microchips that has 576 electrodes (9 electrodes in a microchip times 64 microchips).


Subject(s)
Action Potentials/physiology , Choroid/physiology , Electric Stimulation Therapy/instrumentation , Electronics, Medical/instrumentation , Retinal Ganglion Cells/physiology , Therapy, Computer-Assisted/instrumentation , Animals , Choroid/surgery , Electric Stimulation Therapy/methods , Electronics, Medical/methods , Equipment Design , Equipment Failure Analysis , Miniaturization , Rabbits , Retina/physiology , Retina/surgery , Retinal Diseases/rehabilitation , Therapy, Computer-Assisted/methods
11.
Syst Biol (Stevenage) ; 153(5): 372-4, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16986320

ABSTRACT

An approach for analysis of biological networks is proposed. In this approach, named the connectivity matrix (CM) method, all the connectivities of interest are expressed in a matrix. Then, a variety of analyses are performed on GNU Octave or Matlab. Each node in the network is expressed as a row vector or numeral that carries information defining or characterising the node itself. Information about connectivity itself is also expressed as a row vector or numeral. Thus, connection of node n1 to node n2 through edge e is expressed as [n1, n2, e], a row vector formed by the combination of three row vectors or numerals, where n1, n2 and e indicate two different nodes and one connectivity, respectively. All the connectivities in any given network are expressed as a matrix, CM, each row of which corresponds to one connectivity. Using this CM method, intermetabolite atom-level connectivity is investigated in a model metabolic network composed of the reactions for glycolysis, oxidative decarboxylation of pyruvate, citric acid cycle, pentose phosphate pathway and gluconeogenesis.


Subject(s)
Algorithms , Carbohydrate Metabolism/physiology , Cell Physiological Phenomena , Models, Biological , Proteome/metabolism , Signal Transduction/physiology , Adaptation, Physiological/physiology , Animals , Computer Simulation , Feedback/physiology , Homeostasis/physiology , Humans , Kinetics
12.
Conf Proc IEEE Eng Med Biol Soc ; 2006: 2920-3, 2006.
Article in English | MEDLINE | ID: mdl-17946150

ABSTRACT

In the present work, we designed a multi-chip-architecture based flexible neural stimulation device for retinal prosthesis. Based on the multi-chip architecture, a novel CMOS stimulation device was successfully designed and characterized. A packaging technique for thin, flexible neural stimulation device was also proposed and demonstrated. Flip-chip bonding technology plays an essential role in the fabrication of the present thin and flexible neural stimulation device.


Subject(s)
Prosthesis Design , Retina , Animals , Biomedical Engineering , Electric Stimulation , Electrodes, Implanted , Humans , Man-Machine Systems , Retina/physiology
13.
Vet Pathol ; 41(6): 687-91, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15557078

ABSTRACT

A 7-year-old Holstein cow developed a large cystic mass in the region between the atlantoaxis and larynx. The mass extended to the synovium in the atlanto-occipital joint. Many villous projections were present on the inner surface of the tumor tissue, and irregular clefts were formed in the inside. Two cell types, epithelioid-like synovioblasts and spindle cells, were present. Immunohistochemical analysis showed that the cells stained positively for cytokeratin (AE1/AE3) and vimentin. Both cells had similar fine structures ultra-structurally. Vacuoles present in the cytoplasm were full of an acid mucous substance. The tumor was diagnosed as a well-differentiated biphasic synovial sarcoma. This is the first report of a rare case of synovial sarcoma, from the viewpoint of its origin.


Subject(s)
Atlanto-Occipital Joint/pathology , Cattle Diseases/pathology , Sarcoma, Synovial/veterinary , Animals , Atlanto-Occipital Joint/ultrastructure , Cattle , Female , Joint Diseases/pathology , Joint Diseases/veterinary , Pregnancy , Sarcoma, Synovial/pathology , Sarcoma, Synovial/ultrastructure
14.
Kyobu Geka ; 55(3): 243-8, 2002 Mar.
Article in Japanese | MEDLINE | ID: mdl-11889814

ABSTRACT

A 2-year-old boy who had undergone a correction of a type A interruption using a modified Blalock-Park operation, pulmonary artery banding and the division of a patent ductus arteriosus, underwent a Ross operation and closure of ventricular septal defect (VSD). Although a pre-operative echo cardiogram revealed a bicuspid aortic valve, and a Doppler echocardiogram showed only 10 mmHg of pressure gradient across the aortic valve, Ross procedure was performed as a procedure accompanying the closure of a total conus VSD. The total conus VSD was closed with a Dacron patch using pledget mattress sutures. In addition, a running suture was applied over the denuded aortic root and the cranial margin to achieve water tight closure. An aortic root replacement procedure was our first choice for the Ross operation. After both coronary buttons were re-implanted into pulmonary sinuses, a pulmonary artery autograft was wrapped around by the remaining aortic wall for reinforcement to prevent future dilatation. The main pulmonary artery was reconstructed using a bicuspid pericardial valve conduit with a diameter of 24 mm. A post-operative echocardiogram showed no neoaortic valve regurgitation, good coaptation of tri-leaflets, mild regurgitation of pericardial valve and good cardiac performance.


Subject(s)
Abnormalities, Multiple/surgery , Aorta, Thoracic/abnormalities , Aorta, Thoracic/surgery , Aortic Valve/abnormalities , Aortic Valve/surgery , Blood Vessel Prosthesis Implantation/methods , Cardiac Surgical Procedures/methods , Ductus Arteriosus, Patent/surgery , Heart Septal Defects, Ventricular/surgery , Pulmonary Artery/surgery , Child, Preschool , Humans , Male , Reoperation , Treatment Outcome
15.
Electrophoresis ; 22(16): 3365-70, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11669511

ABSTRACT

Exposure of the skin to sunlight results in an increase in the content of epidermal urocanic acid, a key metabolite of L-histidine, and some portions of the metabolite penetrate into the body fluid. S-[2-Carboxy-1-(1H-imidazol-4-yl)ethyl]glutathione (GS(CIE)), an adduct of glutathione and urocanic acid, was proposed to be an origin of a urinary compound, S-[2-carboxy-1-(1 H-imidazol-4-yl)ethyl]-L-cysteine (Cys(CIE)). Various catabolites of Cys(CIE) were also isolated from human urine previously. However, no direct evidence to show the existence of GS(CIE) as a biological material had been found. By using capillary electrophoresis, the glutathione adduct has now been found in the extracts of rat tissues from the kidney, liver, skin and blood when the rat was kept under conditions of sunlight irradiation after the fur on the dorsal skin had been clipped. On the other hand, no or a trace of GS(CIE) was determined in rat tissue extracts when the animal was kept indoor in usual manner. The glutathione adduct was isolated from the kidney extract of the sunlight-irradiated rat using ion-exchangers and high-voltage paper electrophoresis, and determined by fast-atom-bombardment mass spectrometry. These results indicate that GS(CIE) formation actually occurs in the body and that the formation is accelerated by exposing the rat to sunlight irradiation. From these findings, we propose an alternative pathway of histidine metabolism which is initiated by the adduction of urocanic acid to glutathione to form GS(CIE) and terminates with the formation of the urinary compounds via Cys(CIE).


Subject(s)
Glutathione/analogs & derivatives , Glutathione/analysis , Histidine/metabolism , Imidazoles/analysis , Animals , Electrophoresis, Capillary/methods , Glutathione/blood , Humans , Imidazoles/blood , Liver/chemistry , Liver/radiation effects , Male , Molecular Structure , Rats , Rats, Wistar , Skin/chemistry , Skin/radiation effects , Spectrometry, Mass, Fast Atom Bombardment/methods , Sunlight , Tissue Extracts/chemistry
16.
Clin Cancer Res ; 7(8): 2463-7, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11489827

ABSTRACT

Oncogene amplification and chromosomal anomalies are found in many solid tumors and are often associated with aggressiveness of cancer. We evaluated the frequency and the role of c-erbB-2 gene amplification, relative increase in c-erbB-2 gene copy number, and gain of chromosome 17 in bladder cancer. A total of 29 bladder cancer specimens were examined using fluorescence in situ hybridization (FISH). Dual labeling hybridization with a directly labeled centromere probe for chromosome 17 together with a probe for the c-erbB-2 locus was performed. c-erbB-2 gene amplification was found in 3.4% (1 of 29) of specimens. Relative increase in c-erbB-2 gene copy number was found in 41.4% (12 of 29) of specimens and was significantly associated with tumor grade (P = 0.044 by Fisher's exact test). Gain of chromosome 17 was identified in 65.5% (19 of 29) of specimens and was significantly associated with tumor grade (P = 0.002 by Fisher's exact test) and tumor stage (P = 0.003 by Fisher's exact test). Our results suggest that c-erbB-2 gene amplification, relative increase in c-erbB-2 gene copy number, and gain of chromosome 17 may play important roles in the development and progression of bladder cancers. Moreover, the use of c-erbB-2 amplification, relative increase in c-erbB-2 gene copy number, and gain of chromosome 17 using FISH, together with tumor grade and stage, may provide a more useful clinical indicator in bladder cancer.


Subject(s)
Gene Amplification , Receptor, ErbB-2/genetics , Urinary Bladder Neoplasms/genetics , Chromosome Aberrations , Chromosomes, Human, Pair 17/genetics , Gene Dosage , Humans , In Situ Hybridization, Fluorescence , Urinary Bladder Neoplasms/pathology
17.
Hinyokika Kiyo ; 47(6): 385-8, 2001 Jun.
Article in Japanese | MEDLINE | ID: mdl-11496393

ABSTRACT

Transrectal ultrasonography (TRUS), computed tomography (CT), and magnetic resonance imaging (MRI) are employed to diagnose the clinical stage of prostate cancer. However, several cases are diagnosed as pathological stage pT3 after total prostatectomy. We investigated the accuracy of the evaluation of pathologic capsular penetration by preoperative pelvic MRI and preoperative serum PSA level and capsular penetration. The diagnostic accuracy of capsular penetration by MRI was 63.3%. On the other hand, the diagnostic accuracy of capsular penetration by preoperative PSA was 89.7% when its cut off value was 17 ng/ml. We conclude that preoperative serum PSA level could be more useful to diagnose accurately stage of prostate cancer than pelvic MRI.


Subject(s)
Biomarkers, Tumor/blood , Magnetic Resonance Imaging , Prostate-Specific Antigen/blood , Prostatic Neoplasms/diagnosis , Prostatic Neoplasms/pathology , Aged , Humans , Male , Neoplasm Invasiveness , Neoplasm Staging , Sensitivity and Specificity
18.
Circ Res ; 89(3): 265-72, 2001 Aug 03.
Article in English | MEDLINE | ID: mdl-11485977

ABSTRACT

Diacylglycerol (DG) kinase (DGK) terminates signaling from DG, which serves as an activator of protein kinase C (PKC), by converting DG to phosphatidic acid. DGK is thus regarded as an attenuator of the PKC activity. In rats, five DGK isozymes have been cloned, but little is known about their role in the heart. In this study, the spatiotemporal expression of DGK isozymes was investigated in rat hearts under a normal condition and after myocardial infarction (MI) by in situ hybridization histochemistry and immunohistochemistry. In normal left ventricular myocardium, DGKalpha, DGKepsilon, and DGKzeta mRNAs were expressed evenly throughout the myocardium, although the DGKalpha expression was very low. In infarcted hearts, the expression of DGKzeta was enhanced in the peripheral zone of the necrotic area and at the border zone 3 and 7 days after MI, and to a lesser extent in the middle layer of the granulation tissue 21 days after MI. The enhanced DGKzeta expression in the infarcted and border areas could be attributed to granulocytes and macrophages. In contrast, the expression of DGKepsilon in the infarcted and border areas was lower than that in the viable left ventricle (LV) throughout the postoperation period. Furthermore, DGKepsilon expression in the viable myocardium 21 days after MI decreased significantly compared with left ventricular myocardium in the sham-operated rats and was completely restored by treatment with captopril. Our results demonstrate that three DGK isozymes are expressed in the heart and that each isozyme might have different functional characteristics in the healing and LV remodeling after MI.


Subject(s)
Captopril/pharmacology , Diacylglycerol Kinase/biosynthesis , Gene Expression/drug effects , Myocardial Infarction/enzymology , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Animals , Blotting, Northern , Body Weight/drug effects , Diacylglycerol Kinase/genetics , Disease Models, Animal , Granulocytes/enzymology , Heart Ventricles/enzymology , Heart Ventricles/pathology , Immunohistochemistry , In Situ Hybridization , Isoenzymes/biosynthesis , Isoenzymes/genetics , Macrophages/enzymology , Male , Myocardial Infarction/pathology , Myocardium/enzymology , Myocardium/pathology , Organ Size/drug effects , RNA, Messenger/analysis , RNA, Messenger/biosynthesis , Rats , Rats, Wistar , Ventricular Remodeling/drug effects
19.
20.
Blood ; 96(3): 910-6, 2000 Aug 01.
Article in English | MEDLINE | ID: mdl-10910904

ABSTRACT

GATA-1 germline mutation in mice results in embryonic lethality due to defective erythroid cell maturation, and thus other hematopoietic GATA factors do not compensate for the loss of GATA-1. To determine whether the obligate presence of GATA-1 in erythroid cells is due to its distinct biochemical properties or spatiotemporal patterning, we attempted to rescue GATA-1 mutant mice with hematopoietic GATA factor complementary DNAs (cDNAs) placed under the transcriptional control of the GATA-1 gene. We found that transgenic expression of a GATA-1 cDNA fully abrogated the GATA-1-deficient phenotype. Surprisingly, GATA-2 and GATA-3 factors expressed from the same regulatory cassette also rescued the embryonic lethal phenotype of the GATA-1 mutation. However, adult mice rescued with the latter transgenes developed anemia, while GATA-1 transgenic mice did not. These results demonstrate that the transcriptional control dictating proper GATA-1 accumulation is the most critical determinant of GATA-1 activity during erythropoiesis. The results also show that there are biochemical distinctions among the hematopoietic GATA proteins and that during adult hematopoiesis the hematopoietic GATA factors are not functionally equivalent.


Subject(s)
DNA-Binding Proteins/genetics , Trans-Activators/genetics , Transcription Factors/genetics , Animals , Erythroid-Specific DNA-Binding Factors , GATA1 Transcription Factor , GATA2 Transcription Factor , GATA3 Transcription Factor , Gene Expression Regulation , Gene Transfer Techniques , Mice , Mice, Transgenic , Mutation , Transcription, Genetic
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