Visual Evoked Potential Recovery by Subretinal Implantation of Photoelectric Dye-Coupled Thin Film Retinal Prosthesis in Monkey Eyes With Macular Degeneration.

Retinal prosthesis or artificial retina is a promising modality of treatment for outer retinal degeneration, caused by primary and secondary loss of photoreceptor cells, in hereditary retinal dystrophy and age-related macular degeneration, respectively. Okayama University-type retinal prosthesis (OUReP) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. The dye-coupled films were implanted by vitreous surgery in the subretinal space of monkey eyes with macular degeneration which had been induced by cobalt chloride injection from the scleral side. A pilot 1-month observation study involved 6 monkeys and a pivotal 6-month observation study involved 8 monkeys. Of 8 monkeys in 6-month group, 3 monkeys underwent dye-coupled film removal at 5 months and were observed further for 1 month. The amplitude of visual evoked potential which had been reduced by macular degeneration did recover at 1 month after film implantation and maintained the level at 6 months. Optical coherence tomography showed no retinal detachment, and full-field electroretinograms maintained a-wave and b-wave amplitudes, indicative of no retinal toxicity. Pathological examinations after 6-month implantation showed structural integrity of the inner retinal layer in close apposition to dye-coupled films. The implanted films which were removed by vitrectomy 5 months later showed light-evoked surface electric potentials by scanning Kelvin probe measurement. The photoelectric dye-coupled film (OUReP), which serves as a light-receiver and a displacement current generator in the subretinal space of the eye, has a potential for recovering vision in diseases with photoreceptor cell loss, such as retinitis pigmentosa and age-related macular degeneration.

Visual evoked potential in RCS rats with Okayama University-type retinal prosthesis (OUReP™) implantation.

Photoelectric dye-coupled polyethylene film, designated Okayama University type-retinal prosthesis or OUReP™, generates light-evoked surface electric potentials and stimulates neurons. The dye-coupled films or plain films were implanted subretinally in both eyes of 10 Royal College of Surgeons rats with hereditary retinal dystrophy at the age of 6 weeks. Visual evoked potentials in response to monocular flashing light stimuli were recorded from cranially-fixed electrodes, 4 weeks and 8 weeks after the implantation. After the recording, subretinal film implantation was confirmed histologically in 7 eyes with dye-coupled films and 7 eyes with plain films. The recordings from these 7 eyes in each group were used for statistical analysis. The amplitudes of visual evoked potentials in the consecutive time points from 125 to 250 ms after flash were significantly larger in the 7 eyes with dye-coupled film implantation, compared to the 7 eyes with plain film implantation at 8 weeks after the implantation (P < 0.05, repeated-measure ANOVA). The photoelectric dye-coupled polyethylene film, as retinal prosthesis, gave rise to visual evoked potential in response to flashing light.

Vaccination with liposome-coupled glypican-3-derived epitope peptide stimulates cytotoxic T lymphocytes and inhibits GPC3-expressing tumor growth in mice.

Because therapeutic manipulation of immunity can induce tumor regression, anti-cancer immunotherapy is considered a promising treatment modality. We previously reported that glypican-3 (GPC3), an oncofetal antigen overexpressed in hepatocellular carcinoma (HCC), is a useful target for cytotoxic T lymphocyte (CTL)-mediated cancer immunotherapy, and we have performed clinical trials using the GPC3-derived peptide vaccine. Although vaccine-induced GPC3-peptide-specific CTLs were often tumor reactive in vitro and were correlated with overall survival, no complete response was observed. In the current study, we synthesized liposome-coupled GPC3-derived CTL epitope peptide (pGPC3-lipsome) and investigated its antitumor potential. Vaccination with pGPC3-liposome induced peptide-specific CTLs at a lower dose than conventional vaccine emulsified in incomplete Freund's adjuvant. Coupling of pGPC3 to liposomes was essential for effective priming of GPC3-specific CTLs. In addition, immunization with pGPC3-liposome inhibited GPC3-expressing tumor growth. Thus, vaccination with tumor-associated antigen-derived epitope peptides coupled to the surfaces of liposomes may be a novel therapeutic strategy for cancer.

Vision maintenance and retinal apoptosis reduction in RCS rats with Okayama University-type retinal prosthesis (OUReP™) implantation.

Photoelectric dye-coupled polyethylene film, designated Okayama University-type retinal prosthesis or OUReP™, generates light-evoked surface electric potentials and stimulates neurons. In this study, the vision was assessed by behavior tests in aged hereditary retinal dystrophic RCS rats with OUReP™, retinal apoptosis and electroretinographic responses were measured in dystrophic eyes with OUReP™. The dye-coupled films, or plain films as a control, were implanted in subretinal space of RCS rats. On behavior tests, RCS rats with dye-coupled films, implanted at the old age of 14 weeks, showed the larger number of head-turning, consistent with clockwise and anticlockwise rotation of a surrounding black-and-white-striped drum, compared with rats with plain films, under the dim (50 lux) and bright (150 lux) conditions in the observation period until the age of 22 weeks (n = 5, P < 0.05, repeated-measure ANOVA). The number of apoptotic cells in retinal sections at the site of dye-coupled film implantation was significantly smaller, compared with the other retinal sites, neighboring the film, or opposite to the film, 5 months after film implantation at the age of 6 weeks (P = 0.0021, Friedman test). The dystrophic eyes of RCS rats with dye-coupled films showed positive responses to maximal light stimulus at a significantly higher rate, compared with the eyes with no treatment (P < 0.05, Chi-square test). Electroretinograms in normal eyes of Wistar rats with dye-coupled or plain films showed significantly decreased amplitudes (n = 14, P < 0.05, repeated-measure ANOVA). In conclusions, vision was maintained in RCS rats with dye-coupled films implanted at the old age. The dystrophic eyes with dye-coupled films showed electroretinographic responses. Five-month film implantation caused no additional retinal changes.

Coupling to the surface of liposomes alters the immunogenicity of hepatitis C virus-derived peptides and confers sterile immunity.

We have previously demonstrated that antigens chemically coupled to the surface of liposomes consisting of unsaturated fatty acids were cross-presented by antigen presenting cells to cytotoxic T lymphocytes (CTLs). Liposomal form of immunodominant CTL epitope peptides derived from lymphocytic choriomeningitis virus exhibited highly efficient antiviral CTL responses in immunized mice. In this study, we coupled 15 highly conserved immunodominant CTL epitope peptides derived from hepatitis C virus (HCV) to the surface of liposomes. We also emulsified the peptides in incomplete Freund's adjuvant, and compared the immune responses of the two methods of presenting the peptides by cytotoxicity induction and interferon-gamma (IFN-γ) production by CD8(+) T cells of the immunized mice. We noticed significant variations of the immunogenicity of each peptide between the two antigen delivery systems. In addition, the immunogenicity profiles of the peptides were also different from those observed in the mice infected with recombinant adenoviruses expressing HCV proteins as previously reported. Induction of anti-viral immunity by liposomal peptides was tested by the challenge experiments using recombinant vaccinia viruses expressing corresponding HCV epitopes. One D(b)-restricted and three HLA-A(*)0201-restricted HCV CTL epitope peptides on the surface of liposomes were found to confer complete protection to immunized mice with establishment of long-term memory. Interestingly, their protective efficacy seemed to correlate with the induction of IFN-γ producing cells rather than the cytotoxicity induction suggesting that the immunized mice were protected through non-cytolytic mechanisms. Thus, these liposomal peptides might be useful as HCV vaccines not only for prevention but also for therapeutic use.

Behavior tests and immunohistochemical retinal response analyses in RCS rats with subretinal implantation of Okayama-University-type retinal prosthesis.

We have developed a photoelectric dye-coupled polyethylene film as a prototype of retinal prosthesis, which we named Okayama University-type retinal prosthesis. The purposes of this study are to conduct behavior tests to assess vision in Royal College of Surgeons (RCS) rats that underwent subretinal implantation of the dye-coupled film and to reveal retinal response to the dye-coupled film by immunohistochemistry. Polyethylene films were made of polyethylene powder at refined purity, and photoelectric dyes were coupled to the film surface at higher density compared with the prototype. Either dye-coupled film or dye-uncoupled plain film used as a control was implanted subretinally from a scleral incision in both eyes of an RCS rat at 6 weeks of the age. Behavior tests 2, 4, 6, and 8 weeks after implantation were conducted by observing head turning or body turning in the direction consistent with clockwise or counterclockwise rotation of a black-and-white-striped drum around a transparent cage housed with the rat. After the behavior tests at 8 weeks, rats' eyes were enucleated to confirm subretinal implantation of the films and processed for immunohistochemistry. In the behavior tests, the number of head turnings consistent with the direction of the drum rotation was significantly larger in RCS rats with dye-coupled- compared with plain-film implantation [P < 0.05, repeated-measure analysis of variance (ANOVA), n = 7]. The number of apoptotic neurons was significantly smaller in eyes with dye-coupled- compared with plain-film implantation (P < 0.05, Mann-Whitney U test, n = 6). In conclusion, subretinal implantation of photoelectric dye-coupled films restored vision in RCS rats and prevented the remaining retinal neurons from apoptosis.

Development of highly durable retinal prosthesis using photoelectric dyes coupled to polyethylene film and quantitativein vitroevaluation of its durability.

Retinal prostheses have been developed to restore vision in blind patients suffering from such diseases as retinitis pigmentosa. In our previous studies, we developed a retinal prosthesis called dye-coupled film by chemical coupling of photoelectric dyes, which absorb light and then generate electrical potential, with a polyethylene film surface. The dye-coupled film is nontoxic, and we recovered the vision of a monkey with macular degeneration. The amount of dye on the dye-coupled film, however, decreased to one-third after five months in the monkey's eye. The photoelectric dye consists of a cation with photoresponsivity and a bromide ion (Br-). Therefore, an anion-exchange reaction could be applied to the dye-coupled film to improve its durability. In this study, the anion-exchange reaction was conducted using bis(trifluoromethanesulfonyl)imide ion (TFSI-), which has lower nucleophilicity than Br-. First, the long-term durability was examined without using animal subjects and in a short period. Subsequently, an elemental analysis was performed to confirm the exchange between Br-and TFSI-, and chemical properties, such as photoresponsivity and durability, before and after the anion exchange, were evaluated. It was quantitatively confirmed that the long-term durability of dye-coupled films can be evaluated in anin vitroenvironment and in a short period of one-thirtieth by utilizing a saline solution at 60 °C, compared with anin vivoenvironment. In addition, the durability of the dye-coupled film with TFSI-was improved to 270%-320% compared with that of the dye-coupled film with Br-.

Modelling the visual response to an OUReP retinal prosthesis with photoelectric dye coupled to polyethylene film.

Objective.Retinal prostheses have been developed to restore vision in blind patients suffering from diseases like retinitis pigmentosa.Approach.A new type of retinal prosthesis called the Okayama University-type retinal prosthesis (OUReP) was developed by chemically coupling photoelectric dyes to a polyethylene film surface. The prosthesis works by passively generating an electric potential when stimulated by light. However, the neurophysiological mechanism of how OUReP stimulates the degenerated retina is unknown.Main results.Here, we explore how the OUReP affects retinal tissues using a finite element model to solve for the potential inside the tissue and an active Hodgkin-Huxley model based on rat vision to predict the corresponding retinal bipolar response.Significance.We show that the OUReP is likely capable of eliciting responses in retinal bipolar cells necessary to generate vision under most ambient conditions.

Photoelectric Dye, NK-5962, as a Potential Drug for Preventing Retinal Neurons from Apoptosis: Pharmacokinetic Studies Based on Review of the Evidence.

NK-5962 is a key component of photoelectric dye-based retinal prosthesis (OUReP). In testing the safety and efficacy, NK-5962 was safe in all tests for the biological evaluation of medical devices (ISO 10993) and effective in preventing retinal cells from death even under dark conditions. The long-term implantation of the photoelectric dye-coupled polyethylene film in the subretinal space of hereditary retinal dystrophic (RCS) rats prevented neurons from apoptosis in the adjacent retinal tissue. The intravitreous injection of NK-5962 in the eyes of RCS rats, indeed, reduced the number of apoptotic cells in the retinal outer nuclear layer irrespective of light or dark conditions. In this study, we reviewed the in vitro and in vivo evidence of neuroprotective effect of NK-5962 and designed pharmacokinetic experiments. The in vitro IC50 of 1.7 µM, based on the protective effect on retinal cells in culture, could explain the in vivo EC50 of 3 µM that is calculated from concentrations of intravitreous injection to prevent retinal neurons from apoptosis. Pharmacokinetics of NK-5962 showed that intravenous administration, but not oral administration, led to the effective concentration in the eye of rats. NK-5962 would be a candidate drug for delaying the deterioration of retinal dystrophy, such as retinitis pigmentosa.

A CTL-based liposomal vaccine capable of inducing protection against heterosubtypic influenza viruses in HLA-A*0201 transgenic mice.

The current vaccination strategy against influenza is to induce the production of antibodies directed against surface antigens of viruses. However, the frequent changes in the surface antigens of influenza viruses allow the viruses to avoid antibody-mediated immunity. On the other hand, it is known that cytotoxic T-lymphocyte (CTL) populations directed against internal antigens of influenza A virus are broadly cross-reactive to influenza virus subtypes. In the present study, liposomal conjugates with CTL epitope peptides derived from highly conserved internal antigens of influenza viruses were evaluated for their ability to protect against infection with influenza viruses. Liposomal conjugates with peptide M1 58-66, an HLA-A*0201-binding CTL epitope present within the amino-acid sequence of the M1 coding region, successfully induced antigen-specific CD8(+) T-cells and CTLs in HLA-A*0201-transgenic mice. Moreover, after nasal infection with either the H1N1 or H3N2 virus, viral replication in the lung was significantly inhibited in the immunized mice. These protective activities lasted at least 6months after the immunization. Thus, these results suggest that liposome-coupled CTL epitope peptides derived from highly conserved internal antigens of influenza viruses might be applicable to the development of vaccines that induce protection against infection with heterosubtypic influenza viruses.

Safety, efficacy, and quality control of a photoelectric dye-based retinal prosthesis (Okayama University-type retinal prosthesis) as a medical device.

Patients with retinitis pigmentosa lose photoreceptor cells as a result of genetic abnormalities and hence become blind. Neurons such as bipolar cells and ganglion cells remain alive even in the retina of these patients, and ganglion cells send axons to the brain as the optic nerve. The basic concept of retinal prostheses is to replace dead photoreceptor cells with artificial devices to stimulate the remaining neurons with electric currents or potentials. Photodiode arrays and digital camera-type electrode arrays are the two main approaches for retinal prostheses to stimulate retinal neurons, but these arrays have the problems of poor biocompatibility, low sensitivity, and low output of electric currents, and hence have a requirement for external electric sources (batteries). To overcome these problems, we are developing photoelectric dye-based retinal prostheses that absorb light and convert photon energy to generate electric potentials. The prototype, using a photoelectric dye-coupled polyethylene film, could induce intracellular calcium elevation in photoreceptor-lacking embryonic retinal tissues and cultured retinal neurons. The subretinal implantation of the prototype in the eyes of Royal College of Surgeons (RCS) rats led to vision recovery as proved by a behavior test. The photoelectric dye that was chosen for the prototype did not exhibit any cytotoxicity. The surface potentials of the photoelectric dye-coupled film showed a rapid on-and-off response to illumination with a threshold for light intensity as measured by a Kelvin probe system. Photoelectric dye-based retinal prostheses are thin and soft, and therefore, a sheet of the film of large size, corresponding to a large visual field, could be inserted into the vitreous and then to the subretinal space through a small opening by rolling up the film. Clinical studies of photoelectric dye-based retinal prostheses in patients with retinitis pigmentosa who lose sight will be planned after the manufacturing control and the quality control had been established for the medical device.

Vision evaluation by functional observational battery, operant behavior test, and light/dark box test in retinal dystrophic RCS rats versus normal rats.

BACKGROUND: Vision plays a key role in some behavior tests for rats. Okayama University-type retinal prosthesis (OUReP) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to assess vision in retinal dystrophic (RCS) rats, in comparison with normal rats, by selected behavior tests. We also examined whether the tests could detect vision changes in RCS rats with dye-coupled film implantation. METHODS: Data sets were 5 normal rats, 4 untreated RCS rats, 7 RCS rats with dye-coupled films implanted at the age of 7 weeks after excluding unsuccessful implantation at autopsy. Behavior tests chosen were landing foot splay and visual forelimb-placing response in the menu of functional observational battery, operant-conditioning lever-press response and light/dark box test. RESULTS: Normal visual placing response was significantly less frequent in untreated RCS rats at the age of 9 and 11 weeks, compared with normal rats (P = 0.0027, chi-square test) while normal response was significantly more frequent at the age of 9 weeks in RCS rats with dye-coupled film implantation, compared with untreated RCS rats (P = 0.0221). In operant-conditioning lever-press test, the correct response rate was significantly lower in untreated RCS rats than in normal rats at the age of 9 weeks (P < 0.05, Tukey-Kramer test) while the rate was not significantly different between normal rats and RCS rats with dye-coupled film implantation. In light/dark box test, the time to enter dark box was significantly shorter in normal rats, compared with untreated RCS rats or RCS rats with dye-coupled film implantation (P < 0.05, Tukey-Kramer test). CONCLUSIONS: Behavior tests of functional observational battery, operant-conditioning lever-press response and light/dark box test discriminated vision between normal rats and RCS rats. The visual placing response and operant-conditioning lever-press test might have sensitivity to detect vision recovery in RCS rats with OUReP implantation.

[Application of surface-linked liposomal antigens for the development of vaccines].

The potential ability of surface-linked liposomal antigens for application to vaccine development was investigated. During the course of this investigation, a significant difference, which correlated closely with the adjuvant activity of liposomes, was observed in the recognition of liposomal antigens by APCs between liposomes with different lipid components. In addition to this "quantitative" difference between liposomes with differential lipid components, a "qualitative" difference (i.e., the differential ability to induce cross-presentation) was observed among liposomes with different lipid components. Although the precise mechanism underlying this difference is currently unclear, the significant difference in membrane mobility observed between these liposomes might affect their ability to induce cross-presentation. Thus, surface-linked liposomal antigens are potentially applicable for the development of vaccines with the least allergic side effects and for a novel protocol of allergen immunotherapy. In addition, by the utilization of their ability to induce cross-presentation, surface-linked liposomal antigen might potentially serve as a candidate protocol for virus vaccines which induce CTL response, and for tumor vaccine preparation to present tumor antigens to APCs and induce effective antitumor responses.

Visual evoked potential in rabbits' eyes with subretinal implantation by vitrectomy of Okayama University-type retinal prosthesis (OURePTM).

Okayama University-type retinal prosthesis (OURePTM) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to test surgical feasibility for subretinal film implantation and to examine functional durability of films in subretinal space. Dye-coupled films were implanted subretinally by vitrectomy in the right eye of normal white rabbits: 8 rabbits for 1 month and 8 rabbits for 6 months. The implanted films were removed by vitrectomy in 4 of these 8 rabbits in 1-month or 6-month implantation group. The films were also implanted in 4 rhodopsin-transgenic retinal dystrophic rabbits. Visual evoked potential was measured before film implantation as well as 1 or 6 months after film implantation, or 1 month after film removal. The films were successfully implanted in subretinal space of retinal detachment induced by subretinal fluid injection with a 38G polyimide tip. The retina was reattached by fluid-air exchange in vitreous cavity, retinal laser coagulation, and silicone oil injection. The ratios of P2 amplitudes of visual evoked potential in the implanted right eye over control left eye did not show significant changes between pre-implantation and post-implantation or post-removal (paired t-test). In Kelvin probe measurements, 4 pieces each of removed films which were implanted for 1 or 6 months showed proportional increase of surface electric potential in response to increasing light intensity. The film implantation was safe and implanted films were capable of responding to light.

Photoelectric Dye Used for Okayama University-Type Retinal Prosthesis Reduces the Apoptosis of Photoreceptor Cells.

PURPOSE: Our previous study demonstrated that photoelectric dye-coupled polyethylene film (Okayama University-type retinal prosthesis), which was implanted in subretinal space of the eyes of Royal College of Surgeons (RCS) rats, prevented retinal neurons from apoptotic death. In this study, we aimed to examine whether photoelectric dye itself would protect retinal neurons from apoptosis in RCS rats. METHODS: RCS rats received intravitreous injection of different concentrations of the dye in the left eye and housed under a 12-h light-dark cycle. Saline injection in the right eye served as control. In addition, RCS rats with dye injection were kept in 24-h daily dark condition. Sections were processed for terminal deoxynucleotidyl transferase-mediated fluorescein-conjugated-dUTP nick-end-labeling (TUNEL) assay and immunohistochemical staining of glial fibrillary acidic protein (GFAP) and protein kinase Cα (PKCα). RESULTS: The number of TUNEL-positive cells significantly decreased in the retina of dye-injected eyes compared with those in saline-injected eyes (P = 0.0001, 2-factor analysis of variance [ANOVA]), under 12-h light-dark cycle. Significant decrease of TUNEL-positive cells was noted in the retina of rats with dye injection compared with those with saline injection, kept under 24-h dark condition (P = 0.0001, 2-factor ANOVA). Immunoreactive area for GFAP decreased significantly in the retina of dye-injected eyes compared with that in controls (P = 0.0001, 2-factor ANOVA), whereas immunoreactive area for PKCα increased significantly in the retina of dye-injected eyes compared with that in controls (P = 0.01, 2-factor ANOVA). CONCLUSIONS: Photoelectric dye inhibits apoptotic death of photoreceptor cells in RCS rats and downregulates GFAP expression in retinal Müller cells. Photoelectric dye may be a candidate agent for neuroprotection in retinitis pigmentosa and other retinal diseases.

Amino group in Leptothrix sheath skeleton is responsible for direct deposition of Fe(III) minerals onto the sheaths.

Leptothrix species produce microtubular organic-inorganic materials that encase the bacterial cells. The skeleton of an immature sheath, consisting of organic exopolymer fibrils of bacterial origin, is formed first, then the sheath becomes encrusted with inorganic material. Functional carboxyl groups of polysaccharides in these fibrils are considered to attract and bind metal cations, including Fe(III) and Fe(III)-mineral phases onto the fibrils, but the detailed mechanism remains elusive. Here we show that NH2 of the amino-sugar-enriched exopolymer fibrils is involved in interactions with abiotically generated Fe(III) minerals. NH2-specific staining of L. cholodnii OUMS1 detected a terminal NH2 on its sheath skeleton. Masking NH2 with specific reagents abrogated deposition of Fe(III) minerals onto fibrils. Fe(III) minerals were adsorbed on chitosan and NH2-coated polystyrene beads but not on cellulose and beads coated with an acetamide group. X-ray photoelectron spectroscopy at the N1s edge revealed that the terminal NH2 of OUMS1 sheaths, chitosan and NH2-coated beads binds to Fe(III)-mineral phases, indicating interaction between the Fe(III) minerals and terminal NH2. Thus, the terminal NH2 in the exopolymer fibrils seems critical for Fe encrustation of Leptothrix sheaths. These insights should inform artificial synthesis of highly reactive NH2-rich polymers for use as absorbents, catalysts and so on.

Subretinal implantation of Okayama University-type retinal prosthesis (OURePTM) in canine eyes by vitrectomy.

Okayama University-type retinal prosthesis (OURePTM) is a photoelectric dye-coupled polyethylene film which generates electric potential in response to light and stimulates nearby neurons. This study aims to test surgical feasibility of subretinal implantation and functional durability of dye-coupled films in the subretinal space. The dye-coupled films were implanted subretinally by 25-gauge vitrectomy in the right eye of 11 normal beagle dogs: 2 dogs served for film removal after 5-month film implantation, 3 dogs for film removal after 3-month film implantation, 3 dogs for 3-month film implantation and pathological examination, and 3 dogs for sham surgery. The surface electric potential of the removed dye-coupled films in response to light was measured by the Kelvin Probe system. At surgery, rolled-up dye-coupled films in 5 × 5 mm square size could be inserted into subretinal space of retinal detachment induced by fluid injection with a 38-gauge polyimide tip. Retinal attachment was maintained by silicone oil injection in vitreous cavity. At autopsy, the retina in all dogs maintained the ganglion cell layer, inner and outer nuclear layers while it lost the outer segments in some part. All 5 sheets of removed dye-coupled films maintained the dye color. One sheet of the 5-month implanted film showed proportional increase of surface potential in response to increasing light intensity. Subretinal implantation of OURePTM by vitrectomy was technically feasible in canine eyes, and OURePTM maintained the function of generating light-evoked surface potential after 5 months in subretinal implantation.

Additional reduction in intraocular pressure achieved with latanoprost in normal-tension glaucoma patients previously treated with unoprostone.

PURPOSE: To determine whether treatment with latanoprost eye drops is able to further reduce intraocular pressure (IOP) in normal-tension glaucoma (NTG) patients whose IOP has been well controlled with unoprostone. PATIENTS AND METHODS: A total of 34 eyes (34 individuals) with NTG that had been treated with 0.12% unoprostone eye drops twice daily for >or=3 months were switched to treatment once daily with eye drops containing 0.005% latanoprost. IOP was measured before and 1, 2, and 3 months after the switch to latanoprost. RESULTS: The mean IOP of all eyes was decreased significantly by 1.8, 2.9, and 2.3 mmHg at 1, 2, and 3 months after the switch from unoprostone to latanoprost treatment. The IOP of patients with an initial IOP of 12 mmHg was reduced by 11.0 or 19.9%, respectively, after 3 months on latanoprost. The IOP of 30 (88.2%) of the 34 eyes was further reduced by the switch from unoprostone to latanoprost. CONCLUSIONS: Latanoprost reduced the IOP of NTG patients who had already been treated with unoprostone, even though both drugs are prostaglandin-related. Switching to latanoprost might thus achieve a maximal decrease in IOP and thereby better prevent damage to the optic nerve and loss of visual field in NTG patients.

Development of a new hybrid gel phantom using carrageenan and gellan gum for visualizing three-dimensional temperature distribution during hyperthermia and radiofrequency ablation.

We developed a new hybrid gel phantom using carrageenan and gellan gum for the purpose of visualizing three-dimensional temperature distribution. The phantom, which contains carrageenan, gellan gum, non-ionic surface active agent, potassium chloride, n-butanol, sodium azide, and water, shows good transparency at room temperature, and has the advantage that the heated region becomes white and opaque due to segregation of the surface active agent. Carrageenan and gellan gum were added to improve the transparency and fragility of the hybrid gel. Potassium chloride was used to adjust the electrical conductivity of the gel to a range of 5-130 MHz, so that it would be equivalent to that of muscle tissue for each frequency used by electromagnetic heating devices. N-butanol was used to adjust the clouding temperature to a range between 45 and 55 degrees C. In the present study we clarified the important properties of the new phantom, and developed formulae for easy determination of the amounts of ingredients necessary for the desired clouding temperature and electric conductivity. The characteristics of this phantom are: a) a solid form to avoid convection by heat conduction; b) sufficient strength without fragility to form a torso without the use of a reinforcing agent; c) high transparency at room temperature and visualization of the heating area as a white turbidity; d) time-lapse and accurate visualization of the changing temperature area without thermal hysteresis; e) electrical properties similar to those of human tissues; f) ease of production; and g) low cost and good safety. This phantom might assist oncologists in their routine checking and study of the performance of electromagnetic heating devices for hyperthermia and radiofrequency ablation.

Nocardioides aromaticivorans sp. nov., a dibenzofuran-degrading bacterium isolated from dioxin-polluted environments.

Seven strains of dibenzofuran (DF)-degrading bacteria isolated from dioxin-polluted environments were characterized. These isolates were able to grow with dibenzofuran as the sole carbon and energy source. During the growth with dibenzofuran, they produced a soluble yellow metabolite that exhibited a unique pH-dependent shift of absorption maxima. Dibenzo-p-dioxin and biphenyl were also degraded with pigment production. The isolates were strictly aerobic and chemoorganotrophic and had gram-positive, nonmotile, rod-shaped cells. Chemotaxonomic analyses showed that cells contained L,L-diaminopimeric acid in the peptidoglycan, branched-chain fatty acids as major fatty acids, and menaquinone MK-8(H4) as the sole respiratory quinone. The G + C content of the DNA of the isolates ranged from 72.0 to 72.4 mol%. The 16S rRNA gene sequences of the isolates were very similar to each other (> or = 99.8%). The phylogenetic analysis showed that the isolates formed a cluster with species of the genus Nocardioides with Nocardioides simplex and Nocardioides nitrophenolicus as their nearest neighbors. DNA-DNA hybridization studies showed that the isolates showed a hybridization level of less than 55% to any tested species of the genus Nocardioides. Based on these data, Nocardioides aromaticivorans sp. nov. is proposed for the new DF-degrading isolates. The type strain is strain H-1 (IAM 14992, JCM 11674, DSM 15131).