Design of an Oral Tablet Containing Furosemide Nanoparticles with Elevated Bioavailability

The solubility and permeability of the Biopharmaceutics Classification System (BCS) class IV drugs, such as furosemide (FUR), are low. Thus, the oral bioavailability of these drugs needs to be augmented. Here, we aimed to design orally disintegrating tablets containing FUR nanoparticles to improve bioavailability after oral administration. The FUR nanoparticles were generated by bead-milling in water containing 0.5% methylcellulose and 0.5% 2-hydroxypropyl-β-cyclodextrin (w/w%). Particle size was approximately 47-350 nm (mean particle size, 188 nm). An orally disintegrating tablet (FUR-NP tablet) comprising FUR nanoparticles (1%) was successfully produced by employing suspensions outlined above that incorporated additives (4% D-mannitol, 0.4% polyvinylpyrrolidone, and 16% gum Arabic, w/w%), followed by freeze-drying. The FUR-NP tablet disaggregated after only 5 s in water, liberating nano-sized FUR particles (172 nm). Experiments using rats showed the absorption of the FUR-NP tablet was significantly improved by comparison with a FUR tablet containing microparticles. In summary, the orally disintegrating tablet containing FUR nanoparticles markedly enhanced the bioavailability of FUR. We anticipate this formulation will also improve the bioavailability of other BCS class IV drugs.

Recovery from indomethacin-induced gastrointestinal bleeding by treatment with teprenone

BACKGROUND

Gastrointestinal injuries caused by nonsteroidal anti-inflammatory drugs (NSAIDs) is a serious side effect in patients with rheumatoid arthritis (RA). However, effective therapeutic strategies have yet to be established. In this study, we investigated the therapeutic effects of teprenone (TEP), a gastric mucosal protective drug, on NSAID-induced gastrointestinal injuries in rats with RA (AA rats).

METHODS

Gastrointestinal injury was induced by oral administration of indomethacin (IMC), a typical NSAID. TEP was orally administered after IMC-induced gastrointestinal bleeding, and the stomach, jejunum, and ileum were excised.

RESULTS

On day 14 of IMC administration, lesion areas in the stomach, jejunum, and ileum were significantly larger in AA rats than in normal rats. When TEP was orally administered to AA rats, the lesion areas in the stomach, jejunum, and ileum significantly decreased compared with those in control rats (IMC-induced AA rats). Therefore, we measured NOS2 mRNA and NO levels, which were significantly decreased in rats with IMC-induced AA after treatment with TEP.

CONCLUSIONS

These results suggest that the oral administration of TEP may be useful for the treatment of NSAID-induced gastrointestinal injuries in patients with RA.

Nasal Absorption Enhancement of Mometasone Furoate Nanocrystal Dispersions

Purpose

We designed a 0.05% mometasone furoate (MF) nanocrystal dispersion and investigated whether the application of MF nanocrystals in nasal formulations enhanced local absorption compared to traditional nasal MF formulations (CA-MF).

Methods

MF nanocrystal dispersions (MF-NPs) were prepared by bead milling MF microcrystal dispersions (MF-MPs) consisting of MF, 2-hydroxypropyl-β-cyclodextrin, methylcellulose, and purified water. Pluronic F-127 combined with methylcellulose, Pluronic F-68, or carbopol was used as a base for in situ gelation (thickener). MF concentrations were measured using high-performance liquid chromatography, and nasal absorption of MF was evaluated in 6 week-old male Institute of Cancer Research (ICR) mice.

Results

The particle size range of MF prepared with the bead mill treatment was 80-200 nm, and the nanoparticles increased the local absorption of MF, which was higher than that of CA-MF and MF-MPs. In addition, unlike the results obtained in the small intestine and corneal tissue, the high absorption of nanocrystalline MF in the nasal mucosa was related to a pathway that was not derived from energy-dependent endocytosis. Moreover, the application of the in situ gelling system attenuated the local absorption of MF-NPs, owing to a decrease in drug diffusion in the dispersions.

Conclusion

We found that nanoparticulation of MF enhances local intranasal absorption, and nasal bioavailability is higher than that of CA-MF. In addition, we demonstrate that viscosity regulation is an important factor in the design of nasal formulations based on MF nanocrystals. These findings provide insights for the design of novel nanomedicines with enhanced nasal bioavailability.

Skin absorption of felbinac solid nanoparticles in gel formulation containing l-menthol and carboxypolymethylene

BACKGROUND

It is important to design an effective formulation to enhance the skin penetration, and nanotechnologies have been used in dermal and transdermal drug delivery. In this study, we prepared formulations (gels) containing l-menthol and felbinac (FEL) solid nanoparticles (FEL-NP gel) for topical application, and investigated the local and systemic absorption of the prepared FEL-NP gel.

METHODS

FEL solid nanoparticles were obtained by bead milling of FEL powder (microparticles), and a topical formulation (FEL-NP gel) consisting of 1.5% FEL solid nanoparticles), 2% carboxypolymethylene, 2% l-menthol, 0.5% methylcellulose, and 5% 2-hydroxypropyl-β-cyclodextrin (w/w %) were prepared.

RESULTS

The particle size of FEL nanoparticles was 20-200 nm. The released FEL concentration from FEL-NP gel was significantly higher than that from FEL gel without bead mill treatment (carboxypolymethylene gel in which FEL microparticles (MPs) instead of FEL nanoparticles were incorporated, FEL-MP gel), and FEL was released as nanoparticles from the gel. Moreover, both transdermal penetration and percutaneous absorption of FEL-NP gel were significantly increased compared with those of FEL-MP gel, and the area under the FEL concentration-time curve (AUC) of FEL-NP gels was 1.52- and 1.38-fold of commercially available FEL ointment and FEL-MP gel, respectively. In addition, after 24 h of treatment, the FEL content in rat skin treated with FEL-NP gels was 1.38- and 2.54-fold higher than that when treated with commercially available FEL ointment and FEL-MP gel, respectively. Moreover, the enhanced skin penetration of FEL-NP gels was significantly attenuated by inhibition of energy-dependent endocytosis, such as clathrin-mediated endocytosis.

CONCLUSIONS

We successfully prepared a topically applied carboxypolymethylene gel containing FEL nanoparticles. In addition, we observed that the endocytosis pathway was mainly related to the high skin penetration of FEL nanoparticles, and FEL-NP gel application resulted in high local tissue concentration and systemic absorption of FEL. These findings provide useful information for the design of topically applied nanoformulations against inflammation by providing local and systemic effects.

Orally disintegrating tablets containing famotidine nanoparticles provide high intestinal absorbability via the energy-dependent endocytosis pathway

The permeability of the Biopharmaceutics Classification System (BCS) class III drugs are low, and their oral bioavailability needs to be improved. In this study, we attempted to design oral formulations containing famotidine (FAM) nanoparticles to overcome the limitations of BCS class III drugs. Dispersions containing FAM nanoparticles with a particle size of approximately 50–220 nm were produced by the bead-milling treatment. Moreover, we succeeded in preparing an orally disintegrating tablet containing FAM nanoparticles using the dispersions described above, additives (D-mannitol, polyvinylpyrrolidone, and gum arabic), and freeze-dry treatment (FAM-NP tablet). The FAM-NP tablet was disaggregated 3.5 s after addition to purified water, and the FAM particles in the redispersion of the FAM-NP tablet stored for 3 months were nano-sized (141 ± 6.6 nm). The ex-vivo intestinal penetration and in vivo absorption of FAM in rats applied with the FAM-NP tablet were significantly higher than those in rats applied with the FAM tablet containing microparticles. In addition, enhanced intestinal penetration of the FAM-NP tablet was attenuated by an inhibitor of clathrin-mediated endocytosis. In conclusion, the orally disintegrating tablet containing FAM nanoparticles improved low mucosal permeability and low oral bioavailability and overcame these issues of BCS class III drugs as oral formulations.

Effect of Ointment Base on the Skin Wound-Healing Deficits in Streptozotocin-Induced Diabetic Rat

Wound-healing deficits of the skin, one of the most common complications in patients with diabetes, delay wound healing, significantly reducing the patient's QOL. Therefore, the topical treatment of wound areas with drug-containing ointments and dressings is important. In this study, we investigated the effect of various ointment bases on skin wound healing in normal and streptozotocin-induced diabetic rats (STZ rats). Three ointment bases were used: white ointment (oil-based), absorbent cream (emulsion-based, w/o), and macrogol ointment (water-based). Skin wound healing in STZ rats was delayed compared with that in normal rats. Each of the three ointment bases was applied to the skin wound area in normal rats, and there was no difference in the therapeutic effect. The therapeutic effect of both white ointment and absorbent cream was higher in the STZ rats group than that in the non-treated group, and delayed wound healing was observed in STZ rats treated with macrogol ointment. In conclusion, skin wound healing in STZ rats is affected by the properties of the ointment base, and it is important to use an ointment base that controls the drying of the wound area in STZ rats. These findings provide information for the selection of ointment bases useful for application to skin wounds in patients with diabetes.

Function of mitochondrial cytochrome c oxidase is enhanced in human lens epithelial cells at high temperatures

Enhancement of density via human lens epithelium (HLE) cell proliferation is the underlying cause of nuclear cataracts. Moreover, our previous epidemiological study demonstrated that the risk of nuclear cataract development is significantly higher under elevated environmental temperatures compared with under lower temperatures. The present study investigated the relationship between temperature and cell proliferation in terms of mitochondrial function, which is a nuclear cataract‑inducing risk factor, using two different HLE cell lines, SRA01/04 and immortalized human lens epithelial cells NY2 (iHLEC‑NY2). Cell proliferation was significantly enhanced under the high‑temperature condition (37.5˚C) in both cell lines. The cell growth levels of SRA01/04 and iHLEC‑NY2 cells cultured at 37.5˚C were 1.20‑ and 1.16‑fold those in the low‑temperature cultures (35.0˚C), respectively. Moreover, the levels of cytochrome c oxidase mRNA (mitochondrial genome, cytochrome c oxidase‑1‑3) and its activity in SRA01/04 and iHLEC‑NY2 cells cultured at 37.5˚C were higher compared with those in cells cultured at 35.0˚C. In addition, adenosine‑5'‑triphosphate (ATP) levels in SRA01/04 and iHLEC‑NY2 cells were also significantly higher at 37.5˚C compared with those at 35.0˚C. By contrast, no significant differences in Na⁺/K⁺‑ATPase or Ca²⁺‑ATPase activities were observed between HLE cells cultured at 35.0 and 37.5˚C. These results suggested that expression of the mitochondrial genome was enhanced in high‑temperature culture, resulting in a sufficient ATP content and cell proliferation for lens opacity. Therefore, elevated environmental temperatures may increase the risk of nuclear cataracts caused by HLE cell proliferation via mitochondrial activation.

Effect of storage temperature on the dispersibility of commercially available 0.1% fluorometholone ophthalmic suspension

In this study, we focused on the storage conditions and investigated the effects of low-temperature storage (10°C) on the dispersibility of active components in three formulations of fluorometholone (FLU) suspension eye-drops (one original drug and two generic drugs, P1-P3). For all three eye-drop products, before shaking by hand, white sediment anticipated to be the principal active component was seen at the vial base. In the ordinary-temperature storage group, the FLU contents per drop after shaking by hand were 0.076% in P1, 0.023% in P2, and 0.100% in P3, and the content in P2 was significantly lower than that in P1 and P3. In contrast, almost no dispersion was observed in the low-temperature group. The results after sufficient shaking of these samples with a vortex, in contrast, were such that the FLU contents per drop were 0.063% in P1, 0.086% in P2, and 0.088% in P3; the content in P1 was significantly lower than that in P2 and P3, and there was no difference between P2 and P3. Moreover, we evaluated the dispersibility according to the evaluation “V_s / (ρ_g − ρ_f) g.” In both the low- and ordinary-temperature storage groups, the value of V_s / (ρ_g − ρ_f) g, proportional to the terminal velocity, decreased in the following order: P3 > P1 ≫ P2, and each value in the ordinary-temperature was higher than that in low temperature. The zeta potential decreased in the following order: P2 > P3 ≫ P1. In conclusion, when FLU suspension eye drops are stored at low temperatures until use, such as in a refrigerator, ordinary shaking does not help achieve dispersion to the specified concentration, and even with vigorous shaking with some formulations, the specified concentration cannot be achieved.

[Effects of Skin Environmental Changes by Steam Towel, Ethanol, l-Menthol and Carpronium on the Drug Behavior in the Minoxidil Nanoparticles-applied Mice]

We previously designed the formulation containing minoxidil (MXD) nanoparticles (MXD-NPs), and found that the MXD-NPs can mainly deliver MXD into hair bulbs via hair follicles pathway, and that the therapeutic efficiency for hair growth is higher in comparison with the formulation containing dissolved MXD. In this study, we investigated whether the skin environmental changes by the treatment of steam towel, ethanol, l-menthol and commercially available (CA) carpronium affect the drug behavior in the MXD-NPs-applied mice. The steam towel, ethanol, l-menthol and CA-carpronium were pre-treated 3 min before MXD-NPs application, and the MXD content in the hair bulge, bulb, skin tissue and blood of mice were measured 4 h after MXD-NPs application. No significant difference of MXD levels in the blood was observed by the pre-treatment of steam towel, ethanol, l-menthol and CA-carpronium. On the other hand, the pre-treatment of steam towel and l-menthol enhanced the MXD levels in hair bulge and/or bulb. Although, the MXD levels in hair bulge and bulb were not changed by the pre-treatment of ethanol, the MXD levels in skin tissue was higher than that of saline-pre-treated group (control). The MXD levels in hair bulge, bulb and skin tissue of mice pre-treated with CA-carpronium were remarkably higher in comparison with control. In conclusion, we showed that the changes in skin environment by the steam towel, ethanol, l-menthol and CA-carpronium affected the absorption of MXD-NPs, and these increased MXD levels in the hair bulb and blood by the combination may enhance the therapeutic efficiency without side effects.

Nanocrystalline Suspensions of Irbesartan Enhance Oral Bioavailability by Improving Drug Solubility and Leading Endocytosis Uptake into the Intestine

We attempted to design irbesartan nanocrystalline (IRB-NC) suspensions by the bead mill method, and we evaluated the bioavailability (BA) in the oral administration of the nanocrystalline drug. The mean particle size of the IRB-NC suspensions was approximately 140 nm, and the crystalline structure of irbesartan in these suspensions was different using the bead mill method. The aggregation and degradation of irbesartan were not observed for one month, and the solubility increased. Moreover, the inclusion complex formation of IRB-NC suspensions with 2-hydroxypropyl-β-cyclodextrin was higher than that in traditional IRB powder (IRB-P). In addition, the intestinal absorption of IRB-NC suspensions was higher than that of IRB-P suspensions, and the reducing effect on blood pressure in spontaneously hypertensive SHR-SP rats orally administered IRB-NC suspensions was significantly higher than in those administered IRB-P suspensions. On the other hand, the intestinal penetration of IRB-NC suspensions was attenuated by the inhibitors of clathrin-dependent endocytosis (CME). In conclusion, we improved the low oral BA of irbesartan by preparing IRB-NC suspensions and showed that both the solubility and CME are related to the enhanced intestinal absorption of IRB-NC suspensions, resulting in an increase in their antihypertensive effect. These findings provide significant information for the development of oral nanomedicines.

[Effect of Shelf Life on the Physical Stability of Suspended Ophthalmic Solutions]

Quality changes associated with physical changes in suspended eye drops are difficult to predict. In this study, we attempted to evaluate the aggregation and redispersability in commercially available suspended eye drops (fluorometholone ophthalmic solutions). The 0.1% fluorometholone ophthalmic solutions (the original product and 4 generic products) were gently mixed by hand after short-term (4 months) or long-term (40 months) storage, and the drug concentration in the first drop and physical stability (redispersability and particle size) were measured. All eye drops produced a cloudy precipitate on the bottom surface of the container, and the amount of precipitate decreased with mixing time. The drug concentration per drop in the original product was approximately 70% of the labeled value after mixing 10 times, and the drug particle size was approximately 4 μm. After mixing the generic products stored short-term 10 times, the concentration ranged from less than 50% to almost 100%. In addition, some generic products after long-term storage had a reduced redispersion ability and labeled concentration. These results suggested that at least 10 mixing were required before the using of fluorometholone original product. In addition, some generic products may not provide sufficient drug exposure even when mixed in the same manner as the original products.

Prevention of Postprandial Hyperglycemia by Ophthalmic Nanoparticles Based on Protamine Zinc Insulin in the Rabbit

Postprandial hyperglycemia, a so-called blood glucose spike, is associated with enhanced risks of diabetes mellitus (DM) and its complications. In this study, we attempted to design nanoparticles (NPs) of protamine zinc insulin (PZI) by the bead mill method, and prepare ophthalmic formulations based on the PZI-NPs with (nPZI/P) or without polyacrylic acid (nPZI). In addition, we investigated whether the instillation of the newly developed nPZI and nPZI/P can prevent postprandial hyperglycemia in a rabbit model involving the oral glucose tolerance test (OGTT). The particle size of PZI was decreased by the bead mill to a range for both nPZI and nPZI/P of 80-550 nm with no observable aggregation for 6 d. Neither nPZI nor nPZI/P caused any noticeable corneal toxicity. The plasma INS levels in rabbits instilled with nPZI were significantly higher than in rabbits instilled with INS suspensions (commercially available formulations, CA-INS), and the plasma INS levels were further enhanced with the amount of polyacrylic acid in the nPZI/P. In addition, the rapid rise in plasma glucose levels in OGTT-treated rabbits was prevented by a single instillation of nPZI/P, which was significantly more effective at attenuating postprandial hyperglycemia (blood glucose spike) in comparison with nPZI. In conclusion, we designed nPZI/P, and show that a single instillation before OGTT attenuates the rapid enhancement of plasma glucose levels. These findings suggest a better management strategy for the postprandial blood glucose spike, which is an important target of DM therapy.

MPC Polymer Promotes Recovery from Dry Eye via Stabilization of the Ocular Surface

The polymer that includes 2-methacryloyloxy ethyl phosphorylcholine (MPC) is well-known as an effectively hydrating multifunction agent. In this study, we prepared an MPC polymer (MPCP) using radical polymerization with co-monomers-MPC/Stearyl Methacrylate/N,N-dimethylacrylamide-and evaluated the MPCP's usefulness for dry eye treatment using a rabbit model treated with N-acetylcysteine. The MPCP particle size was 50-250 nm, and the form was similar to that of micelles. The MPCP viscosity (approximately 0.95 mPa·s) was 1.17-fold that of purified water, and a decrease in the transepithelial electrical resistance value (corneal damage) was not observed in the immortalized human corneal epithelial cell line HCE-T cell (HCE-T cell layer). The MPCP enhanced the water maintenance on the cornea, and the instillation of MPCP increased the lacrimal fluid volume and prolonged the tear film breakup time without an increase in total mucin contents in the lacrimal fluid of the normal rabbits. The therapeutic potential of the MPCP for dry eye was evaluated using an N-acetylcysteine-treated rabbit model, and, in our investigation, we found that MPCP enhanced the volume of lacrimal fluid and promoted an improvement in the tear film breakup levels. These findings regarding the creation and characteristics of a novel MPCP will provide relevant information for designing further studies to develop a treatment for dry eyes.

Effect of a Lens Protein in Low-Temperature Culture of Novel Immortalized Human Lens Epithelial Cells (iHLEC-NY2)

The prevalence of nuclear cataracts was observed to be significantly higher among residents of tropical and subtropical regions compared to those of temperate and subarctic regions. We hypothesized that elevated environmental temperatures may pose a risk of nuclear cataract development. The results of our in silico simulation revealed that in temperate and tropical regions, the human lens temperature ranges from 35.0 °C to 37.5 °C depending on the environmental temperature. The medium temperature changes during the replacement regularly in the cell culture experiment were carefully monitored using a sensor connected to a thermometer and showed a decrease of 1.9 °C, 3.0 °C, 1.7 °C, and 0.1 °C, after 5 min when setting the temperature of the heat plate device at 35.0 °C, 37.5 °C, 40.0 °C, and 42.5 °C, respectively. In the newly created immortalized human lens epithelial cell line clone NY2 (iHLEC-NY2), the amounts of RNA synthesis of αA crystallin, protein expression, and amyloid β (Aβ)1-40 secreted into the medium were increased at the culture temperature of 37.5 °C compared to 35.0 °C. In short-term culture experiments, the secretion of Aβ1-40 observed in cataracts was increased at 37.5 °C compared to 35.0 °C, suggesting that the long-term exposure to a high-temperature environment may increase the risk of cataracts.

In Situ Gelling Systems Using Pluronic F127 Enhance Corneal Permeability of Indomethacin Nanocrystals

We previously designed an ophthalmic dispersion containing indomethacin nanocrystals (IMC-NCs), showing that multiple energy-dependent endocytoses led to the enhanced absorption of drugs from ocular dosage forms. In this study, we attempted to prepare Pluronic F-127 (PLF-127)-based in situ gel (ISG) incorporating IMC-NCs, and we investigated whether the instillation of the newly developed ISG incorporating IMC-NCs prolonged the precorneal resident time of the drug and improved ocular bioavailability. The IMC-NC-incorporating ISG was prepared using the bead-mill method and PLF-127, which yielded a mean particle size of 50–150 nm. The viscosity of the IMC-NC-incorporating ISG was higher at 37 °C than at 10 °C, and the diffusion and release of IMC-NCs in the IMC-NC-incorporating ISG were decreased by PLF-127 at 37 °C. In experiments using rabbits, the retention time of IMC levels in the lacrimal fluid was enhanced with PLF-127 in the IMC-NC-incorporating ISG, whereby the IMC-NC-incorporating ISG with 5% and 10% PLF-127 increased the transcorneal penetration of the IMCs. In contrast to the results with optimal PLF-127 (5% and 10%), excessive PLF-127 (15%) decreased the uptake of IMC-NCs after instillation. In conclusion, we found that IMC-NC-incorporating ISG with an optimal amount of PLF-127 (5–10%) resulted in higher IMC corneal permeation after instillation than that with excessive PLF-127, probably because of the balance between higher residence time and faster diffusion of IMC-NCs on the ocular surface. These findings provide significant information for developing ophthalmic nanomedicines.

An in situ Gelling System Based on Methylcellulose and Tranilast Solid Nanoparticles Enhances Ocular Residence Time and Drug Absorption Into the Cornea and Conjunctiva

We previously developed ophthalmic formulations containing tranilast nanopartaicles (ophthalmic TL-NPs formulations), and found them to show high uptake into ocular tissues. In this study, we aimed to design an in situ gel incorporating TL-NPs with 0.5–3% methylcellulose (MC, type SM-4) to ensure long residence time of the drug at the ocular surface. The ophthalmic TL-NPs formulations were prepared by the bead mill method, which yielded a mean particle size of ~93 nm with or without MC (0.5–3%). Although the dispersibility of TL particles in ophthalmic formulations increased with the MC content, the diffusion behavior of TL particles in the dispersion medium decreased with MC content. In an in vivo study using rats, the TL content in the lacrimal fluid was enhanced with MC content in the ophthalmic TL-NPs formulations, and the optimum amount of MC (0.5–1.5%) enhanced the TL content in the cornea and conjunctiva, and an anti-inflammatory effect of TL in rats instilled with ophthalmic TL-NPs formulations was observed. On the other hand, excessive MC (3%) prevented the corneal uptake of TL-NPs after instillation, and the anti-inflammation effect of TL was lower than that of ophthalmic TL-NPs formulations with optimum MC (0.5–1.5%). In conclusion, we found that gel formulations of TL-NPs with 0.5 and 1.5% MC provided a prolonged pre-corneal and pre-conjunctival contact time of TL, and resulted in higher TL contents in the cornea and conjunctiva following instillation in comparison with TL-NPs with or without 3% MC. This is probably due to the balance between the higher residence time and faster diffusion of TL-NPs on the ocular surface. These findings provide significant information that can be used to design further studies aimed at developing ophthalmic nanomedicines.

Retinal proteomic evaluation of rats following streptozotocin‑injection using shotgun proteomics

It is important to elucidate how retinal stimulation leads to retinal protection and dysfunction. The current study aimed to identify factors that are up‑ and downregulated in the retinas of streptozotocin (STZ)‑induced diabetic rats with acute retinal dysfunction. Retinal function was measured and changes in protein expressions were determined using electroretinograms (ERGs) and liquid chromatography/mass spectroscopy‑based shotgun proteomics, respectively. The results revealed that the plasma glucose levels of STZ rats were markedly higher when compared with normal rats. Furthermore, levels of a‑waves, b‑waves and oscillatory potential amplitudes on ERGs in STZ rats were decreased compared with healthy animals. With use of shotgun proteomics, 391 proteins were identified in the retinas of normal rats and 541 proteins were found in the retinas of STZ rats. Of the 560 proteins identified in rat retinas, 372 (66.4%) were present in both normal and STZ rats. Of these, 19 (3.39%) were unique to normal rats and 169 (30.1%) were unique to STZ rats. Gene Ontology analysis was performed on the candidate proteins that were differentially regulated in the retinas of STZ rats and focused on those classified as 'protein binding', which serve important roles in retinal neurodegeneration. The results revealed an excessive expression of retinol‑binding protein 1 (RBP1) and a negative expression of rod outer segment membrane protein 1 (Rom-1) in the retinas of STZ rats. Therefore, retinal function may be decreased with STZ‑induced injury, and expressions of Rom‑1 and RBP1 may be altered in the retinas of STZ rats.

Solid Nanocrystals of Rebamipide Promote Recovery from Indomethacin-Induced Gastrointestinal Bleeding

Indomethacin (IMC)-induced gastrointestinal (GI) injuries are more common in rheumatoid arthritis (RA) patients than in other IMC users, and the overexpression of nitric oxide (NO) via inducible NO synthase (iNOS) is related to the seriousness of IMC-induced GI injuries. However, sufficient strategies to prevent IMC-induced GI injuries have not yet been established. In this study, we designed dispersions of rebamipide (RBM) solid nanocrystals (particle size: 30–190 nm) by a bead mill method (RBM-NDs), and investigated whether the oral administration of RBM-NDs is useful to prevent IMC-induced GI injuries. The RBM nanocrystals were spherical and had a solubility 4.71-fold greater than dispersions of traditional RBM powder (RBM-TDs). In addition, the RBM-NDs were stable for 1 month after preparation. The RBM contents in the stomach, jejunum, and ileum of rats orally administered RBM-NDs were significantly higher than in rats administered RBM-TDs. Moreover, the oral administration of RBM-NDs decreased the NO levels via iNOS and area of the GI lesions in IMC-stimulated RA (adjuvant-induced arthritis rat) rats in comparison with the oral administration of RBM-TDs. Thus, we show that the oral administration of RBM-NDs provides a high drug supply to the GI mucosa, resulting in a therapeutic effect on IMC-induced GI injuries. Solid nanocrystalline RBM preparations may offer effective therapy for RA patients.

Therapeutic Potential of a Combination of Magnesium Hydroxide Nanoparticles and Sericin for Epithelial Corneal Wound Healing

We previously found the instillation of sericin to be useful as therapy for keratopathy with or without diabetes mellitus. In this study, we investigated whether a combination of solid magnesium hydroxide nanoparticles (MHN) enhances epithelial corneal wound healing by sericin using rabbits, normal rats and type 2 diabetes mellitus rats with debrided corneal epithelium (ex vivo and in vivo studies). Ophthalmic formulations containing sericin and MHN (N-Ser) were prepared using a bead mill method. The mean particle size of the N-Ser was 110.3 nm at the time of preparation, and 148.1 nm one month later. The instillation of N-Ser had no effect on the amount of lacrimal fluid in normal rabbits (in vivo), but the MHN in N-Ser was found to expand the intercellular space in ex vivo rat corneas. In addition, the instillation of N-Ser increased the phosphorylation of Extracellular Signal-regulated Kinase (ERK)1/2, a factor involved in cell adhesion and cell proliferation in the corneal epithelium, in comparison with the instillation of sericin alone. The combination with MHN enhanced epithelial corneal wound healing by sericin in rat debrided corneal epithelium (in vivo). This study provides significant information to prepare potent drugs to cure severe keratopathy, such as diabetic keratopathy.

Coherent anti-Stokes Raman scattering rigid endoscope toward robot-assisted surgery

Label-free visualization of nerves and nervous plexuses will improve the preservation of neurological functions in nerve-sparing robot-assisted surgery. We have developed a coherent anti-Stokes Raman scattering (CARS) rigid endoscope to distinguish nerves from other tissues during surgery. The developed endoscope, which has a tube with a diameter of 12 mm and a length of 270 mm, achieved 0.91% image distortion and 8.6% non-uniformity of CARS intensity in the whole field of view (650 μm diameter). We demonstrated CARS imaging of a rat sciatic nerve and visualization of the fine structure of nerve fibers.

Evaluation of Retinal Function in Streptozotocin-induced Diabetic Rats by Using the Electroretinography and Immunohistochemistry Methods

Streptozotocin-induced diabetic rat (STZ rat) was used in many studies for the diabetic mellitus. In this study, we demonstrated whether the electroretinograms (ERG) was changed in the retina of STZ rats. In addition, we investigated the histopathological alteration in the retina of STZ rats by using the immunological method. The 100 mg/kg of STZ was injected continuously for 2 d (100 mg/kg×2). The insulin level was decreased, and the glucose level was enhanced 14 d after the injection of STZ. Moreover, the levels of a-wave, b-wave and OP amplitude were decreased in the rat at 14 d after the injection of STZ. Although, the damage and apoptosis was not observed in the retinal ganglion cell of STZ rats by the immunological experiment using the phospho-H2A.X and cleaved caspase-3, the distance between cell and cell was increased in both of outer- and inner- nuclear (granule) layer in retina of STZ rats. In conclusion, we showed that the enhanced thickening in retina was caused by the injection of excessive STZ. The thickening in retina of STZ rats may lead to the dysfunction of retina, resulting in the decrease in ERG. These findings provide significant information that can be used in the design of a model of diabetic retinopathy.

Combination Ointment Containing Solid Tranilast Nanoparticles and Dissolved Sericin Is Efficacious for Treating Skin Wound-Healing Deficits and Redness in Diabetic Rats

We attempted to design a combination ointment containing solid tranilast nanoparticles and dissolved sericin as a wound-healing drug (TS-combination ointment), and evaluated its usefulness as therapy for wound-healing deficits in streptozotocin-induced diabetic rat (STZ rat) using kinetic analyses as an index. Solid tranilast nanoparticles were prepared by bead mill methods with low-substituted methylcellulose; the mean particle size of the tranilast nanoparticles was 70 nm. The ointment was designed to contain the tranilast nanoparticles plus sericin powder and/or Carbopol^® 934. Skin wound healing in STZ rats begins significantly later than in normal rats. Although the skin wound healing rate in STZ rats treated with an ointment containing tranilast nanoparticles was lower than in STZ rats treated with vehicle, the ointment was effective in reducing redness. An ointment containing sericin enhanced the skin-healing rate, but the preventive effect on redness was weak. On the other hand, the combination of tranilast and sericin increased both the skin healing rate and reduction in redness. In conclusion, we have adapted kinetic analyses to skin wound healing in rats, and found these analyses to be useful as an index of wound healing ability by a wound-healing drug. In addition, we show that treatment with the TS-combination ointment enhances the skin wound healing rate and reduces redness. These findings provide information significant to the search for new wound-healing therapies and for the design of wound-healing drugs.

Oncogenic effects of evolutionarily conserved noncoding RNA ECONEXIN on gliomagenesis

Accumulating studies have demonstrated the importance of long noncoding RNAs (lncRNAs) during oncogenic transformation. However, because most lncRNAs are currently uncharacterized, the identification of novel oncogenic lncRNAs is difficult. Given that intergenic lncRNA have substantially less sequence conservation patterns than protein-coding genes across species, evolutionary conserved intergenic lncRNAs are likely to be functional. The current study identified a novel intergenic lncRNA, LINC00461 (ECONEXIN) using a combined approach consisting of searching lncRNAs by evolutionary conservation and validating their expression in a glioma mouse model. ECONEXIN was the most highly conserved intergenic lncRNA containing 83.0% homology with the mouse ortholog (C130071C03Rik) for a region over 2500 bp in length within its exon 3. Expressions of ECONEXIN and C130071C03Rik were significantly upregulated in both human and mouse glioma tissues. Moreover, the expression of C130071C03Rik was upregulated even in precancerous conditions and markedly increased during glioma progression. Functional analysis of ECONEXIN in glioma cell lines, U87 and U251, showed it was dominantly located in the cytoplasm and interacted with miR-411-5p via two binding sites within ECONEXIN. Inhibition of ECONEXIN upregulated miR-411-5p together with the downregulation of its target, Topoisomerase 2 alpha (TOP2A), in glioma cell lines, resulting in decreased cell proliferation. Our data demonstrated that ECONEXIN is a potential oncogene that regulates TOP2A by sponging miR-411-5p in glioma. In addition, our investigative approaches to identify conserved lncRNA and their molecular characterization by validation in mouse tumor models may be useful to functionally annotate novel lncRNAs, especially cancer-associated lncRNAs.

N = 16 spherical shell closure in 24O

The unbound excited states of the neutron drip-line isotope 24O have been investigated via the 24O(p,p')23O + n reaction in inverse kinematics at a beam energy of 62  MeV/nucleon. The decay energy spectrum of 24O* was reconstructed from the momenta of 23O and the neutron. The spin parity of the first excited state, observed at E(x) = 4.65±0.14  MeV, was determined to be J(π) = 2+ from the angular distribution of the cross section. Higher-lying states were also observed. The quadrupole transition parameter β2 of the 2(1)+ state was deduced, for the first time, to be 0.15±0.04. The relatively high excitation energy and small β2 value are indicative of the N = 16 shell closure in 24O.

Halo structure of the island of inversion nucleus 31Ne

The cross sections for single-neutron removal from the very neutron-rich nucleus 31Ne on Pb and C targets have been measured at 230 MeV/nucleon using the RIBF facility at RIKEN. The deduced large Coulomb breakup cross section of 540(70) mb is indicative of a soft E1 excitation. Comparison with direct-breakup model calculations suggests that the valence neutron of 31Ne occupies a low-l orbital (most probably 2p(3/2)) with a small separation energy (S(n) approximately < 0.8 MeV), instead of being predominantly in the 1f(7/2) orbital as expected from the conventional shell ordering. These findings suggest that 31Ne is the heaviest halo system known.

Spectroscopy of 32Ne and the "Island of Inversion"

We report on the first spectroscopic study of the N=22 nucleus 32Ne at the newly completed RIKEN Radioactive Ion Beam Factory. A single gamma-ray line with an energy of 722(9) keV was observed in both inelastic scattering of a 226 MeV/u 32Ne beam on a carbon target and proton removal from 33Na at 245 MeV/u. This transition is assigned to the deexcitation of the first Jpi=2+ state in 32Ne to the 0+ ground state. Interpreted through comparison with state-of-the-art shell-model calculations, the low excitation energy demonstrates that the "island of inversion" extends to at least N=22 for the Ne isotopes.

Low-intensity pulsed ultrasound accelerates periodontal wound healing after flap surgery

BACKGROUND AND OBJECTIVE

A study was conducted to evaluate the effects of low-intensity pulsed ultrasound on wound healing in periodontal tissues after mucoperiosteal flap surgery.

MATERIAL AND METHODS

Bony defects were surgically produced bilaterally at the mesial roots of the mandibular fourth premolars in four beagle dogs. The flaps were repositioned to cover the defects and sutured after scaling and planing of the root surface to remove cementum. The affected area in the experimental group was exposed to low-intensity pulsed ultrasound, daily for 20 min, for a period of 4 wk from postoperative day 1 using a probe, 13 mm in diameter. On the control side, no ultrasound was emitted from the probe placed contralaterally. After the experiment, tissue samples were dissected out and fixed in 10% formalin for histological and immunohistochemical analyses.

RESULTS

The experimental group showed that the processes in regeneration of both cementum and mandibular bone were accelerated by low-intensity pulsed ultrasound compared with the control group. In addition, the expression level of heat shock protein 70 was higher in the gingival epithelial cells of the low-intensity pulsed ultrasound-treated tooth.

CONCLUSION

Our results suggest that osteoblasts, as well as cells in periodontal ligament and gingival epithelium, respond to mechanical stress loaded by low-intensity pulsed ultrasound, and that ultrasound accelerates periodontal wound healing and bone repair.

Intracellular stress transmission through actin stress fiber network in adherent vascular cells

Intracellular stress transmission through subcellular structural components has been proposed to affect activation of localized mechano-sensing sites such as focal adhesions in adherent cells. Previous studies reported that physiological extracellular forces produced heterogeneous spatial distributions of cytoplasmic strain. However, mechanical signaling pathway involved in intracellular force transmission through basal actin stress fibers (SFs), a mechano-responsive cytoskeletal structure, remains elusive. In the present study, we investigated force balance within the basal SFs of cultured smooth muscle cells and endothelial cells by (i) removing the cell membrane and cytoplasmic constituents except for materials physically attaching to the substrate (i.e., SF-focal adhesion complexities) or (ii) dislodging either mechanically or chemically the cell processes of the cells expressing fluorescent proteins-labeled actin and focal adhesions in order, to examine stress-release-induced deformation of the basal SFs. The result showed that a removal of mechanical restrictions for SFs resulted in a decrease in the length of the remaining SFs, which means SFs bear tension. In addition, a release of the preexisting tension in a single SF was transmitted to another SF physically linked to the former, but not transmitted to the other ones physically independent of the former, suggesting that the prestress is balanced in tensed SF networks. These results support a hypothesis regarding cell structural architecture that physiological extracellular forces can produce in the basal SF network a directional intracellular stress or strain distribution. Therefore, consideration of the coexistence of the directional stretching strain along the axial direction of SFs and the heterogeneous strain in the other cytoplasmic region will be essential for understanding intracellular stress transmission in the adherent cells.

Evaluation of tension in actin bundle of endothelial cells based on preexisting strain and tensile properties measurements

Actin bundles in vascular endothelial cells (ECs) play a critical role in transmitting intracellular forces between separate focal adhesion sites. However, quantitative descriptions of tension level in single actin bundles in a physiological condition are still poorly studied. Here, we evaluated magnitude of preexisting tension in a single actin bundle of ECs on the basis of measurements of its preexisting stretching strain and tensile properties. Cultured ECs expressing fluorescently-labeled actin were treated with detergents to extract acin bundles. One end of an actin bundle was then dislodged from the substrate by using a microneedle, resulting in a shortening of the actin bundle due to a release of preexisting tension. Assuming the shortened actin bundle reached its non-stress state, preexisting stretching strain was determined to be 0.24 on average. A tensile test of the dislodged single acin bundle was conducted with a pair of cantilevers to measure the force required for stretching it up to the original length, yielding an estimate of preexisting tension in the actin bundle. The magnitude of the preexisting tension, 4 nN on average, was comparable to previously reported data of the traction force generated by adherent cells at single adhesion sites to keep cell integrity. The Young's modulus of the isolated actin bundle was estimated to be approximately 300 kPa from the tensile tests together with evaluation of average diameter of the isolated actin bundle based on transmission electron microscopy. These data will contribute to better understanding of intracellular stress transmission mechanism in ECs.

Impaired blood rheology by remnant-like lipoprotein particles: studies in patients with fatty liver disease

Fatty liver disease (FLD) characterised by a high plasma levels of lipoproteins and remnant-like lipoproteins (RLP) is a risk factor for impaired microvascular blood flow, endothelial cell dysfunction and atherosclerosis. Using an immunoseparation technique with a gel mixture containing human monoclonal antibodies to apo A-I and apo B-100, we separated and measured RLP cholesterol (RLP-C) levels which reflect RLP in patients with FLD (n=20). Whole blood transit time (TT) was determined by a microchannel method (MC-FAN) which allows blood flow to be viewed via a microscope connected to an image display unit. RLP-C levels were higher (P<0.01) in FLD, 15.6 +/- 1.0 mg/dl compared with 4.8 +/- 0.5 mg/dl for controls (n=20). Similarly, TT was longer (P<0.01) in FLD, 284.5 +/- 26.1 sec/100 microl compared with 82.8 +/- 1.0 sec/100 microl for controls. Since the liver is a major site for RLP formation and degradation, it is affected to a greater extent in patients with FLD. It is likely that high levels of RLP can impair microvascular perfusion in the liver tissue and contribute to the development and progression of FLD.

Stable colloidal dispersions of fullerenes in polar organic solvents

Colloidal dispersions of C60 and C70 were prepared by simply mixing a fullerene solution in a good solvent with a poor polar organic solvent for fullerenes. The process was very easy and fast and the formation of particles with average diameter in the colloidal range was detected immediately after the components were mixed. The formation and the properties of the fullerene particles were studied mainly with dynamic light scattering and high-resolution transmission electron microscopy. The most interesting findings are the long-term colloid stability of the samples in the absence of any stabilizers, the relatively narrow size distribution, and the different average sizes of the particles formed by C60, C70, and their mixtures. The influence of various factors such as fullerene concentration, mixing procedure, solvent properties, and C60/C70 ratio was investigated. It is shown that the smaller particles are formed when the total fullerene concentration in the good solvent is decreased and that the fullerene particles have crystalline structure. The measured negative values for the electrophoretic mobility of the particles suggest that fullerene dispersions in polar organic solvents are stabilized by repulsive electrostatic interactions.

Characterization of 5' flanking region of alpha isoform of rat Ca2+/calmodulin-dependent protein kinase II gene and neuronal cell type specific promoter activity

The 5' flanking region of the alpha isoform of the rat Ca2+/calmodulin-dependent protein kinase II (alpha CaM kinase II) gene was isolated in 2.3 kbp of genomic sequence. Functional analysis of alpha CaM kinase II promoter deletion mutants fused to a reporter gene in neuroblastoma, including N18TG2, NG108-15, and CAD cells revealed strong transcriptional activity localized 100-145 bp, and a potent silencer 199-275 bp upstream of the transcription start site. The promoter is inactive in non-neuronal cells including BALB/c 3T3, Chinese hamster ovary, HT1080, and C6 glioma cells. These results indicated that the alpha CaM kinase II gene is transcribed from a tissue-specific promoter which is under intense negative control.

Large-scale fires and time trends of PCDDS/DFs in sediments

Drastic increases in PCDDs/DFs concentrations were identified in the uppermost layers of a sediment core sample taken from the coastal area of Kobe City. As large-scale fires caused by the Great Hanshin-Awaji earthquake were deemed to be a possible cause, we performed additional sampling of sediment cores and surface sediment samples, estimating the total amount of PCDDs/DFs released from fires and presuming the load to sediments by individual transport routes, such as air and water, using an air diffusion model to investigate the influence of fires. The total amount of PCDDs/DFs released from fires was estimated at 2000 g-total PCDDs/DFs, 22 g-TEQ. Increases in PCDDs/DFs generated in fires were principally transported through water rather than air. If 20% of the total PCDDs/DFs formed in fires had entered water, it would correspond to the entire increase of PCDDs/DFs concentration in sediment cores.

Successful treatment of advanced natural killer cell lymphoma with high-dose chemotherapy and syngeneic peripheral blood stem cell transplantation

CD56+ angiocentric lymphoma has currently been recognized as a distinct clinical entity which is the prototype of the putative NK cell lymphomas. A 16-year-old Japanese girl with advanced CD56+ angiocentric lymphoma received high-dose chemotherapy supported with syngeneic peripheral blood stem cell transplantation (PBSCT). Prior to syngeneic PBSCT, she received six cycles of conventional chemotherapy before transplantation, resulting in a partial response. PBSC were mobilized with granulocyte colony-stimulating factor (G-CSF) and collected from her identical twin. High-dose cyclophosphamide, MCNU, etoposide, and carboplatin were used for pretransplant conditioning. Syngeneic PBSCT was well tolerated. She achieved complete remission and is now surviving in continuous complete remission for more than 30 months after syngeneic PBSCT. Thus, marrow-ablative chemotherapy facilitated by autologous or allogeneic PBSCT should be considered as part of the primary therapy for poor prognosis NK cell lymphomas.

Analyses of microsatellite instability and the transforming growth factor-beta receptor type II gene mutation in sporadic breast cancer and their correlation with clinicopathological features

To determine the incidence of microsatellite instability (MSI) and its relationship with both clinicopathologic parameters and patient survival, 101 cases of breast cancer were investigated. In addition, transforming growth factor-beta (TGF-beta) receptor type II (RII) gene mutation was also examined to clarify the relation to MSI in breast cancer development. MSI and RII gene mutation were screened by single strand conformation polymorphism (SSCP). The mutations of the RII gene were confirmed by a direct sequence. An association between the MSI status and the clinicopathological features was examined to assess the potential of the MSI status as a prognostic indicator in sporadic breast cancer cases. MSI was detected in 12 of 101 (11.9%) breast cancer cases. The positive MSI breast cancer cases showed relatively more advanced disease than negative MSI cases, and also exhibited relatively poorer prognoses. No RII gene mutations were observed in any of the breast cancer cases. Our data suggest that the MSI status may thus be a useful indicator for the prognosis of sporadic breast cancer cases. However, the breast seems to be an infrequent target organ for cancer development through RII gene mutations. As a result, tumor progression through this pathway appears to be related to organ specificity. For positive MSI breast cancers, other target genes therefore still need to be identified.

Protective effect of FK409, a spontaneous nitric oxide releaser, on ischemic acute renal failure in rats

The contribution of nitric oxide (NO) to ischemic acute renal failure (ARF) is controversial. In the present study, we investigated the effect of FK409 ((+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexanamide ), a spontaneous NO donor, on ischemic ARF in rats. Ischemic ARF was induced by occlusion of the left renal artery and vein for 45 min followed by reperfusion, 2 weeks after contralateral nephrectomy. Renal functional parameters such as blood urea nitrogen, plasma creatinine, creatinine clearance, urine flow, urinary osmolality and fractional excretion of sodium were measured to test the effectiveness of the drug. Renal function in untreated ARF rats markedly decreased at 24 hr after reperfusion and thereafter tended to recover gradually. Intravenous bolus injection of FK409 at a dose of 1 mg/kg before the occlusion markedly attenuated the ischemic ARF-induced decreases in renal function, to the same extent as verapamil (1 mg/kg i.v.). The protective effect of FK409, at a dose of 3 mg/kg, was much more potent than that of the lower dose. Histopathological examination of the kidney of untreated ARF rats revealed severe renal damages, such as tubular necrosis, proteinaceous casts in tubuli and medullary congestion. These renal damages were significantly attenuated by treatment with FK409, at each dose given and this attenuation exceeded that seen with verapamil treatment. FK 409 administration led to a dose-dependent increase in NO metabolites concentration in renal venous blood immediately after the reperfusion. These findings suggest that NO has a crucial role in the pathogenesis of ischemic ARF. Spontaneous NO donors may be clinically effective in cases of ischemic ARF.

Phagocytic function of salivary PMN after smoking or secondary smoking

Alterations in polymorphonuclear leukocyte (PMN) functions, such as phagocytosis, chemotaxis, and oxidative burst, play a pivotal role in periodontal pathogenesis. In addition, previous studies have demonstrated a strong relationship between smoking and periodontal disease. In the present study, the effect of cigarette smoking or passive smoking (secondary smoking) on the phagocytic function of salivary PMN (SPMN) was investigated. Twenty volunteers with clinically healthy gingiva (10 smokers, 10 non-smokers) participated in this study. In a small room, the smokers and passive smokers (non-smokers) were instructed to smoke and breathe, respectively, in an identical, specific way for about 4 minutes. SPMN was isolated immediately before and after smoking or passive smoking. PMN was then incubated with fluoresbrite beads for 45 minutes at 37 degrees C and the phagocytic status estimated by using a flow cytometer. Cell viability was determined by trypan blue exclusion (smokers before smoking: 88.3%: smokers after smoking: 89.6%: non-smokers before passive smoking: 89.0%; non-smokers after passive smoking: 89.4%). In both smokers and passive smokers, the proportion of phagocytic cells increased between before and after smoking (smokers before: 33.2%; after: 42.1%: passive smokers before: 36.2%: after: 44.1%). Both increases were statistically significant (P < 0.01). These results demonstrate that the phagocytic activity of SPMN intensifies after smoking and passive smoking. They also suggest that certain substances in cigarette smoke, perhaps nicotine, overstimulate the host response in the oral cavity.