To image inflammation sites, we developed a novel nanoparticle, hydroxylamine-containing nanoparticle (HANP), which emits an intense electron spin resonance (ESR)-signal triggered by enzymatic oxidation reaction and pH-sensitive self-disintegration. The nanoparticle was prepared from an amphiphilic block copolymer, poly(ethylene glycol)-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-hydroxyl)aminomethylstyrene](PEG-b-PMNT-H), which spontaneously forms a core-shell type polymeric micelle (particle diameter = ca. 50 nm) in aqueous media. Because the PMNT-H segment in the block copolymer possesses amino groups in each repeating unit, the particle can be disintegrated by protonation of the amino groups in an acidic pH environment such as inflammation sites, which is confined to the hydrophobic core of HANP. Mixing HANP with horseradish peroxidase (HRP)/H(2)O(2) mixture resulted in enzymatic oxidization of the hydroxylamines in the PEG-b-PMNT-H and converted the hydroxylamine to the stable nitroxide radical form in PEG-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-oxyl)aminomethylstyrene](PEG-b-PMNT), which shows an intense ESR signal. It is interesting to note that the ESR signal increased at a greater rate under acidic conditions (pH 5.6) than that under neutral conditions (pH 7.4), although the enzymatic activity of HRP under neutral conditions is known to be much higher than that under acidic conditions. This indicates that enzymatic oxidation reaction was accelerated by synchronizing the disintegration of HANP under acidic conditions. On the basis of these results, HANP can be used as a high-performance ESR probe for imaging of inflammation sites.

Background: Intracerebral hemorrhage is reported to induce the generation of reactive oxygen species and oxidative DNA damage in the brain. Aims: We aimed to examine whether our designed redox polymer nanoparticle could reduce intracerebral hemorrhage induced by 1-MHz focused ultrasound sonication coupled with microbubble treatment. Materials & methods: Contrast-enhanced ultrasound imaging, frozen section, brain edema, neurologic deficit, the number of morphologically normal neurons, DNA oxidization and superoxide anion generation were used to investigate the neuroprotective effect of redox polymer nanoparticles. Results: We confirmed that the 1-MHz focused ultrasound coupled with microbubble produced intracerebral hemorrhage and showed that the redox polymer nanoparticle ameliorates intracerebral hemorrhage-induced brain edema, neurological deficit and oxidative damage. Conclusion: These results suggest that redox polymer nanoparticle is a potential therapeutic agent for intracerebral hemorrhage induced by focused ultrasound. Original submitted: 23 June 2011; Revised submitted: 24 October 2011.

Various polymeric materials have been used in medical devices, including blood-contacting artificial organs. Contact between blood and foreign materials causes blood cell activation and adhesion, followed by blood coagulation. Concurrently, the activated blood cells release inflammatory cytokines together with reactive oxygen species (ROS). We have hypothesized that the suppression of ROS generation plays a crucial role in blood activation and coagulation. To confirm this hypothesis surface-coated polymers containing nitroxide radical compounds (nitroxide radical-containing polymers (NRP)) were designed and developed. The NRP was composed of a hydrophobic poly(chloromethylstyrene)(PCMS) chain to which 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) moieties were conjugated via condensation reaction of the chloromethyl groups in PCMS with the sodium alkylate group of 4-hydroxy-TEMPO. Blood compatibility was investigated by placing NRP-coated beads in contact with rat whole blood. The amount of ROS generated on PCMS-coated beads used as a control increased significantly with time, while NRP-coated beads suppressed ROS generation. It is interesting to note that the suppression of inflammatory cytokine generation by NRP-coated beads was shown to be significantly higher than that by PCMS-coated beads. Both platelet and leukocyte adhesion to the beads were suppressed with increasing TEMPO incorporation in the polymer. These results confirm that the suppression of ROS by NRP prevents inflammatory cytokine generation, which in turn results in the suppression of blood activation and coagulation on the beads.

To examine structural changes in the lacrimal sac epithelium and associated lymphoid tissue of rabbits with experimentally induced dacryocystitis. Experimental dacryocystitis was induced by an inoculation of Staphylococcus aureus into the lacrimal sac. The histological changes of the inflamed lacrimal sac epithelium and associated lymphoid tissue were studied by light and electron microscopy. After 1 month, numerous inflammatory cells (CD20-positive B lymphocytes, CD3-positive T lymphocytes, IgA-positive plasma cells, and polymorphonuclear leukocytes) infiltrated the lamina propria and the epithelium overlying the diffuse lymphoid tissue. Three months later, the density of the infiltrated leukocytes was markedly decreased. The epithelial lining overlying the diffuse lymphoid tissue became thicker with numerous secretory granules in the supranuclear regions. The lacrimal sac epithelium and associated lymphoid tissue play a major role in the defense mechanism during inflammation. Overproduction of secretory granules after bacterial inoculation could enhance the antimicrobial defense.

BLAST analysis of the rat genome revealed the presence of 16 pseudogenes of isoform 1 of the mitochondrial voltage-dependent anion channel (VDAC1). Based on their structural characterization, it was concluded that these pseudogenes were formed by integration of VDAC1 cDNA into the genome, and subsequent rearrangements/mutations. By RT-PCR analysis using carefully designed primers that could not amplify the cDNA of genuine VDAC1, 8 of these 16 pseudogenes showed slight expression in certain tissues, but none of them seemed to encode a functional protein.

To describe risk factors associated with primary open-angle glaucoma (POAG) in Japanese subjects who participated in community health screenings. Residents of Akita, Japan, participating in a community health checkup were selected to undergo a comprehensive ophthalmic examination. Glaucoma was diagnosed based on optic disk appearance, perimetric results, and other ocular findings. Systemic blood pressure and intraocular pressure were measured and ocular perfusion pressure was calculated. Logistic regression analysis was performed to determine risk factors for POAG patients. Of the 710 subjects examined, 26 had POAG. The estimated prevalence of POAG was 3.7%. After adjusting for age, the prevalence of POAG was similar to that found in the Tajimi Study of Japanese subjects. Multivariate logistic regression analysis demonstrated that older age (≥60 years, odds ratio [OR]: 3.49), lower diastolic blood pressure (≤58 mmHg, OR: 2.11), higher intraocular pressure (≥19 mmHg, OR: 4.12), and lower ocular perfusion pressure (≤34 mmHg, OR: 5.78) were associated with increased risk of having POAG. These findings may be relevant for identifying high risk groups.

Pulmonary sequestration is defined as nonfunctional lung tissue that lacks communication with the bronchial tree and that is supplied by an anomalous systemic vessel. In comparatively rare cases, pulmonary sequestration may lead to hydrothorax or hydrops fetalis, which is nearly universally fatal. In this report, we describe a case of pulmonary sequestration with hydrops fetalis, which was successfully treated by thoracoamniotic shunting. A sonographic Doppler study in this case suggested that the underlying mechanism of the hydropic change in a fetus with extralobar pulmonary sequestration may have differed from that in fetuses with primary hydrothorax not associated with a structural anomaly. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011;

The antioxidant effect and potential mechanism of nitroxide radical-containing nanoparticles (RNPs) coupled with piperine (PI) were investigated in human neuroblastoma SH-SY5Y cells. The effects of RNP/PI on SH-SY5Y cell lines was determined by WST assay for cell viability, nitroblue tetrazolium and deoxyribose assay for reactive oxygen species generation, ELISA assay for reactive oxygen species products and apoptotic cell death, and biochemical techniques for catalase and glutathione peroxidase activity. The RNP/PI significantly reduced the reactive oxygen species level and reactive oxygen species products compared with those of cells treated with RNPs alone. The RNP/PI treatment enhanced catalase and glutathione peroxidase activity. The combination of RNP/PI has been found to have an augmented antioxidant effect on an Alzheimer's model in vitro. The mechanism of the protective effect of this combination therapy was correlated in this study with its ability to reduce the generation of reactive oxygen species and prevent apoptosis via scavenging enzyme action pathways.

The ultimate objective of nanoparticle-based therapy is to functionalize nanomedicines in a micro-disease environment without any side effects. Here, we reveal that our pH-responsive nitroxide radical-containing nanoparticles (RNP(pH)) disintegrate within the renal acidic lesion and act as scavengers of reactive oxygen species (ROS), leading to a relief of acute kidney injury (AKI). RNP(pH) was prepared using amphiphilic block copolymers possessing 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) moieties via amine linkage as a side chain of the hydrophobic segment. The self-assembled RNP(pH) disintegrated at pH below 7.0 because of a protonation of the amino groups in the hydrophobic core of the nanoparticles, thereby resulting in an improvement in ROS scavenging activity. Using a renal ischemia-reperfusion AKI model in mice, the therapeutic effect of RNP(pH) on ROS damage was evaluated. Unlike the RNP without pH-triggered disintegration (RNP(Non-pH)), the RNP(pH) showed extremely high ROS scavenging activity and renal protective effects. It is interesting to note that the side effect of nitroxide radicals was markedly suppressed due to the compartmentalization of nitroxide radicals in the core of RNP(pH) in untargeted area. The morphology changes in RNP(pH) were confirmed by analyzing electron spin resonance spectra, and these findings provide the evidence of the real therapeutic effect of the environment-sensitive specific disintegration of nanoparticles in vivo.

Chlorophyll(Chl)-c pigments in algae, diatoms and some prokaryotes are characterized by the fully conjugated porphyrin π-system as well as the acrylate residue at the 17-position. The precise structural characterization of Chl-c(3) from the haptophyte Emiliania huxleyi was performed. The conformations of the π-conjugated peripheral substituents, the 3-/8-vinyl, 7-methoxycarbonyl and 17-acrylate moieties were evaluated, in a solution, using nuclear Overhauser enhancement correlations and molecular modeling calculations. The rotation of the 17-acrylate residue was considerably restricted, whereas the other three substituents readily rotated at ambient temperature. Moreover, the stereochemistry at the 13²-position was determined by combination of chiral high-performance liquid chromatography (HPLC) with circular dichroism (CD) spectroscopy. Compared with the CD spectra of the structurally related, synthetic (13²R)- and (13²S)-protochlorophyllide(PChlide)-a, naturally occurring Chl-c₃ had exclusively the (13²R)-configuration. To elucidate this natural selection of a single enantiomer, we analyzed the three major Chl-c pigments (Chl-c₁, c₂ and c₃) in four phylogenetically distinct classes of Chl-c containing algae, i.e., heterokontophyta, dinophyta, cryptophyta and haptophyta using chiral HPLC. All the photosynthetic organisms contained only the (13²R)-enantiomerically pure Chls-c, and lacked the corresponding enantiomeric (13²S)-forms. Additionally, Chl-c₂ was found in all the organisms as the common Chl-c. These results throw a light on the biosynthesis as well as photosynthetic function of Chl-c pigments: Chl-c₂ is derived from 8-vinyl-PChlide-a by dehydrogenation of the 17-propionate to acrylate residues as generally proposed, and the (13²R)-enantiomers of Chls-c function as photosynthetically active, light-harvesting pigments together with the principal Chl-a and carotenoids.