Fabrication of Yttrium Phosphate Microcapsules by an Emulsion Route for in situ Cancer Radiotherapy

Radiotherapy is a novel, non-invasive cancer treatment. Radioactive hollow microspheres, i.e., microcapsules, are attractive for in situ cancer radiotherapy because they can effectively reach tumors without settling in blood vessels. In particular, microcapsules 20-30 µm in size are expected to exhibit not only a radiotherapy effect but also embolization that blocks the nutrient supply to cancer cells. β-ray irradiation is the most suitable source for in situ radiotherapy because of its moderate range. Several kinds of β-emitting yttria (Y2O3) microcapsules have therefore been developed. Yttrium phosphate (YPO4) should have a longer irradiation effect than that of Y2O3 because the half-life of 31P (14.3days) is longer than that of 90Y (64.1 hours). However, the preparation of YPO4 microcapsules has not been reported to date. In the present study, YPO4 microcapsules were fabricated using a water/oil (W/O) emulsion prepared by first dispersing a YPO4 sol into toluene containing a surfactant, with mechanical homogenization. The emulsion was then added into butanol to dehydrate the water phase and precipitate microcapsules. These were then heat-treated to improve their mechanical strength and chemical stability. Microcapsule fragility at low YPO4 sol concentrations in the water phase was attributed to the thinness of the microcapsule shell. The size of the microcapsules decreased with increasing emulsification speed. The chemical stability of the prepared microcapsules is similar to those of previously reported YPO4 and Y2O3 microspheres in weakly acidic conditions. Thus, little leakage of radioactive species into nearby healthy tissues is expected. The obtained microcapsules are expected to be highly effective for cancer radiotherapy

Fabrication of Yttrium Phosphate Microcapsules by an Emulsion Route for in situ Cancer Radiotherapy

Radiotherapy is a novel, non-invasive cancer treatment. Radioactive hollow microspheres, i.e., microcapsules, are attractive for in situ cancer radiotherapy because they can effectively reach tumors without settling in blood vessels. In particular, microcapsules 20-30 µm in size are expected to exhibit not only a radiotherapy effect but also embolization that blocks the nutrient supply to cancer cells. β-ray irradiation is the most suitable source for in situ radiotherapy because of its moderate range. Several kinds of β-emitting yttria (Y2O3) microcapsules have therefore been developed. Yttrium phosphate (YPO4) should have a longer irradiation effect than that of Y2O3 because the half-life of 31P (14.3days) is longer than that of 90Y (64.1 hours). However, the preparation of YPO4 microcapsules has not been reported to date. In the present study, YPO4 microcapsules were fabricated using a water/oil (W/O) emulsion prepared by first dispersing a YPO4 sol into toluene containing a surfactant, with mechanical homogenization. The emulsion was then added into butanol to dehydrate the water phase and precipitate microcapsules. These were then heat-treated to improve their mechanical strength and chemical stability. Microcapsule fragility at low YPO4 sol concentrations in the water phase was attributed to the thinness of the microcapsule shell. The size of the microcapsules decreased with increasing emulsification speed. The chemical stability of the prepared microcapsules is similar to those of previously reported YPO4 and Y2O3 microspheres in weakly acidic conditions. Thus, little leakage of radioactive species into nearby healthy tissues is expected. The obtained microcapsules are expected to be highly effective for cancer radiotherapy

First Star Survivors as Metal-Rich Halo Stars that Experienced Supernova Explosions in Binary Systems

The search for the first stars formed from metal-free gas in the universe is one of the key issues in astronomy because it relates to many fields, such as the formation of stars and galaxies, the evolution of the universe, and the origin of elements. It is not still clear if metal-free first stars can be found in the present universe. These first stars are thought to exist among extremely metal-poor stars in the halo of our Galaxy. Here we propose a new scenario for the formation of low-mass first stars that have survived until today and observational counterparts in our Galaxy. The first stars in binary systems, consisting of massive- and low-mass stars, are examined using stellar evolution models, simulations of supernova ejecta colliding with low-mass companions, and comparisons with observed data. These first star survivors will be observed as metal-rich halo stars in our Galaxy. We may have identified a candidate star in the observational database where elemental abundances and kinematic data are available. Our models also account for the existence of several solar-metallicity stars in the literature having space velocities equivalent to the halo population. The proposed scenario demands a new channel of star formation in the early universe and is a supplementary scenario for the origin of the known metal-poor stars.Comment: 41 pages, 14 figures, accepted for publication in PASJ (to be published in open access

First star survivors as metal-rich halo stars that experienced supernova explosions in binary systems

The search for the first stars formed from metal-free gas in the universe is one of the key issues in astronomy because it relates to many fields, such as the formation of stars and galaxies, the evolution of the universe, and the origin of elements. It is not still clear if metal-free first stars can be found in the present universe. These first stars are thought to exist among extremely metal-poor stars in the halo of our Galaxy. Here we propose a new scenario for the formation of low-mass first stars that have survived until today and observational counterparts in our Galaxy. The first stars in binary systems, consisting of massive- and low-mass stars, are examined using stellar evolution models, simulations of supernova ejecta colliding with low-mass companions, and comparisons with observed data. These first star survivors will be observed as metal-rich halo stars in our Galaxy. We may have identified a candidate star in the observational database where elemental abundances and kinematic data are available. Our models also account for the existence in the literature of several solar-metallicity stars that have space velocities equivalent to the halo population. The proposed scenario demands a new channel of star formation in the early universe and is a supplementary scenario for the origin of the known metal-poor stars

Secreted factors from adipose tissue-derived mesenchymal stem cells suppress oxygen/glucose deprivation-induced cardiomyocyte cell death via furin/PCSK-like enzyme activity

AbstractClinical application of mesenchymal stem cells (MSCs) represents a potential novel therapy for currently intractable deteriorating diseases or traumatic injuries, including myocardial infarction. However, the molecular mechanisms of the therapeutic effects have not been precisely revealed. Herein, we report that conditioned media (CM) from rat adipose tissue-derived MSCs (ASCs) protected adult cardiomyocytes from oxygen/glucose deprivation (OGD)-induced cell death. We focused on furin/PCSK protease activity in ASC-CM because many therapeutic factors of MSCs and soluble cardioprotective factors include the PCSK cleavage site. We found that recombinant furin protected cardiomyocytes from OGD-induced cell death. The ASC-CM had potent furin/PCSK protease activity and the cardioprotective effect of the CM from ASCs in the OGD-assay was abolished by an inhibitor of the furin/PCSK-like enzyme. Microarray analysis and Western blot analysis showed PCSK5A, the secreted type of PCSK5, is the most abundantly secreted PCSK among 7 PCSK family members in ASC. Finally, knockdown of PCSK5A in ASCs decreased both the furin/PCSK protease activity and cardioprotective activity in the CM. These findings indicate an involvement of furin/PCSK-type protease(s) in the anti-ischemic activity of ASCs, and suggest a new mechanism of the therapeutic effect of MSCs

Etiology and Treatment Approach for Visual Hallucinations in PD Dementia

Visual hallucinations are a common symptom of Parkinson’s disease dementia. These can cause delusions and violent behaviors that can be significant burdens on patients and caregivers. The cause of visual hallucinations is considered to be the dysregulation of the default mode network due to the presence of Lewy bodies in the cortex and the degeneration of dopaminergic and cholinergic neurons. Dopaminergic agents, especially non-ergoline dopamine agonists, can exacerbate visual hallucinations. Reducing the dosage can ameliorate symptoms in many cases; however, this frequently worsens parkinsonism. In contrast, the administration of cholinesterase inhibitors is effective and rarely worsens motor symptoms. In advanced cases, antipsychotic drugs are required; clinical studies have shown that some drugs are beneficial while the adverse events are acceptable. An optimal treatment protocol should be selected depending on the patient’s condition

Red persistent luminescence excited by visible light in CaS:Eu2+,Tm3+

Excitation wavelength dependence of red persistent luminescence in CaS:Eu2+,Tm3+ phosphor is reported. Persistent luminescence appears under visible light excitation in the wavelength region of 400–600nm. Photon energy from white light-emitting diode lamps is possibly stored in this material. This sulfide phosphor is synthesized using iodine vapor. Under iodine vapor, Eu2+ and Tm3+ are found to be efficiently included in CaS. The concentration dependence of Eu2+ is studied, and the optimum concentration is 0.05%. Trap depth of 0.27–0.33eV contributing to persistent luminescence is evaluated by using thermoluminescence

Isolation and immunocharacterization of lactobacillus salivarius from the intestine of wakame-fed pigs to develop novel "Immunosynbiotics"

Emerging threats of antimicrobial resistance necessitate the exploration of effective alternatives for healthy livestock growth strategies. ?Immunosynbiotics?, a combination of immunoregulatory probiotics and prebiotics with synergistic effects when used together in feed, would be one of the most promising candidates. Lactobacilli are normal residents of the gastrointestinal tract of pigs, and many of them are able to exert beneficial immunoregulatory properties. On the other hand, wakame (Undaria pinnafida), an edible seaweed, has the potential to be used as an immunoregulatory prebiotic when added to livestock feed. Therefore, in order to develop a novel immunosynbiotic, we isolated and characterized immunoregulatory lactobacilli with the ability to utilize wakame. Following a month-long in vivo wakame feeding trial in 8-week-old Landrace pigs (n = 6), sections of intestinal mucous membrane were processed for bacteriological culture and followed by identification of pure colonies by 16S rRNA sequence. Each isolate was characterized in vitro in terms of their ability to assimilate to the wakame and to differentially modulate the expression of interleukin-6 (IL-6) and interferon beta (IFN-β) in the porcine intestinal epithelial (PIE) cells triggered by Toll-like receptor (TLR)-4 and TLR-3 activation, respectively. We demonstrated that feeding wakame to pigs significantly increased the lactobacilli population in the small intestine. We established a wakame-component adjusted culture media that allowed the isolation and characterization of a total of 128 Lactobacilli salivarius colonies from the gut of wakame-fed pigs. Interestingly, several L. salivarius isolates showed both high wakame assimilation ability and immunomodulatory capacities. Among the wakame assimilating isolates, L. salivarius FFIG71 showed a significantly higher capacity to upregulate the IL-6 expression, and L. salivarius FFIG131 showed significantly higher capacity to upregulate the IFN-β expression; these could be used as immunobiotic strains in combination with wakame for the development of novel immunologically active feeds for pigs.Fil: Masumizu, Yuki. Tohoku University; JapónFil: Zhou, Binghui. Tohoku University; JapónFil: Humayun Kober, AKM. Tohoku University; Japón. Chittagong Veterinary and Animal Sciences University; BangladeshFil: Islam, M. Aminul. Agricultural University; Bangladesh. Tohoku University; JapónFil: Iida, Hikaru. Tohoku University; JapónFil: Ikeda-Ohtsubo, Wakako. Tohoku University; JapónFil: Suda, Yoshihito. Department Of Food Agriculture, Miyagi University; JapónFil: Albarracín, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Tohoku University; Japón. Universidad Nacional de Tucumán; ArgentinaFil: Nochi, Tomonori. Tohoku University; JapónFil: Aso, Hisashi. Tohoku University; JapónFil: Suzuki, Keiichi. Tohoku University; JapónFil: Villena, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Tohoku University; JapónFil: Kitazawa, Haruki. Tohoku University; Japó