Semiquantitative Analysis by Scanning Electron Microscopy of Cochlear Hair Cell Damage by Ototoxic Drugs

The ototoxicity of cisplatin and carboplatin in the organ of Corti of the guinea pig was evaluated semiquantitatively. Damage of the stereocilia of outer hair cells (OHCs) observed by scanning electron microscopy (SEM) was classified into normal, grade 1 (10-50% loss of stereocilia), grade 2 (less than 50% remaining stereocilia), or grade 3 (missing stereocilia). The OHCs observed by light microscopy (LM) were classified as remaining or missing cells. Fifty OHCs of each row in the middle part of each turn of the cochlea were counted (a total of 150 cells per turn). Guinea pigs were administered 5 mg/kg of cisplatin or 50 mg/kg of carboplatin intraperitoneally for three consecutive days. In groups 1 and 2, in which both cochleae were fixed in 2.5% glutaraldehyde and 1% osmium tetroxide (OsO4) and observed by SEM, the percentages of damage of the OHC stereocilia were similar in each cochlear turn bilaterally. In group 3, the right cochleae were fixed in OsO4 and observed by phase contrast microscopy as surface preparations. Left cochleae were submitted for SEM observation. Missing and grade 3 cells were observed at similar percentages in each row of each turn. In group 4, succinate dehydrogenase staining was performed in the right cochleae and observed by LM. The degree of damage in the right cochleae was compared with that of the left cochleae which was observed by SEM. On average, the mean numbers of missing cells and cells showing grade 3 damage were similar in each row of each turn. From these similarities of evaluation of ototoxicity at LM and SEM levels, it was concluded that semiquantitative analysis by SEM only is appropriate for the assessment of ototoxicity

Studies on the Leaf Temperature of Muscat of Alexandria under Glass. I.

1.Muscat of Alexandria栽培の硝子室(5.4×12.6m)内で地上1.2mおよび棟下部に百葉箱を,また棚部を西側から東側にむかって西下部(I)→西中部(II)→棟部(III)→東中部(IV)→東下部(V)に区分し,葉と硝子面との中間にサーミスタを内包する白厚紙製傘付二重円筒をとりつけた.室内を棟下に電動換気扇(直径25cm)をとりつけた換気区と,無処理区とに区劃し1966年8月5,6の両日に9～17時まで各部位の気温および葉温を測定した.2.無処理区:換気区の順序に示せば8月6日15時の地上百葉箱内気温は36.3:35.8℃,棟直下部のそれは40.3:38.2℃,棟下部の二重円筒内温度は50.0:39.8℃であった.これにくらべてII,III,IV,3部位の同時刻の平均葉温は47.1:38.3℃で両区の差は8.8℃である.3.無処理区の9～17時のI～V各部位の葉温の推移をみると,II,III部位では極めてよく似ており15時には50℃以上となる.IV部位では10時に45.1℃となるが以後低下する.意外にもV部位では11～14時の間46.4～43.6℃でIV部位よりはるかに高温である.I部位では午前中の葉温は最も低いばかりではなく,西から吹いている微風のためか最高温度(15時)も42.7℃にすぎない.4.換気装置による葉温低下効果は大であって,15時の葉温はII:I:III:IV:V部位の順序に示せばそれぞれ43.5:38.9:36.7:34.8:34.8℃であった

Atomic Bomb Fallout and “Black rain” at Manose District (Hirama-cho) Located Northeast of Nagasaki City

Plutonium atomic bomb (A-bomb) was exploded at 503 meters height above Nagasaki City on August 9, 1945. Many studies on radioactive contamination, radiation dose, effect to people and so on have been conducted until now. Local fallout from the A-bomb mainly spread a lot in the east direction centering on Nishiyama area located about 4 km east of the hypocenter. Like the Hiroshima A-bomb, black rain accompanied by radioactive materials fell shortly after the explosion, but relationship between local fallout fall zone and black rain fall area has not been sufficiently elucidated, which has enhanced the concerns on radiation exposure to the A-bomb survivor. Concerning the black rain due to the Nagasaki A-bomb, it has been said that black rain did not fall across a wide area in a comprehensive way, except for the heavily contaminated Nishiyama area, but fell at various areas with conditions of light rain and/or soaking after the explosion. Among many villages or towns, especially in the Manose District where is a small intermountain village about 7.5 km northeast of the hypocenter, it had always been heard and known that the residents living there encountered black rain and experienced hair loss. In this district, the hair loss of inhabitants occurred actually with high probability, but its reason has not been elucidated well. Therefore, in order to reevaluate the local fallout level in the Manose District by the A-bomb, residual long-lived radionuclides 137Cs and Pu isotopes were measured for soil samples collected at the Manose District including the surrounding areas in July, 2011. As a result, accumulated levels of 137Cs and 239,240Pu in the Manose District were not so high, each being nearly background (BG) level. The dispersion of local fallout Pu from the A-bomb was reconfirmed by 240Pu/239Pu atomic ratios measured in soil samples at the same time, and was found to be primarily limited in the east direction, especially around the Nishiyama area. Those results were consistent with results obtained so far. Further researches are needed for understanding scientifically the cause of the high incidence rate of hair loss in this district.This research was supported by JSPS KAKENHI Grants Numbers 23406002 (April 2011-March 2014) and 26257501 (April 2014-March 2018)

Growth Inhibition of Re-Challenge B16 Melanoma Transplant by Conjugates of Melanogenesis Substrate and Magnetite Nanoparticles as the Basis for Developing Melanoma-Targeted Chemo-Thermo-Immunotherapy

Melanogenesis substrate, N-propionyl-cysteaminylphenol (NPrCAP), is selectively incorporated into melanoma cells and inhibits their growth by producing cytotoxic free radicals. Magnetite nanoparticles also disintegrate cancer cells and generate heat shock protein (HSP) upon exposure to an alternating magnetic field (AMF). This study tested if a chemo-thermo-immunotherapy (CTI therapy) strategy can be developed for better management of melanoma by conjugating NPrCAP on the surface of magnetite nanoparticles (NPrCAP/M). We examined the feasibility of this approach in B16 mouse melanoma and evaluated the impact of exposure temperature, frequency, and interval on the inhibition of re-challenged melanoma growth. The therapeutic protocol against the primary transplanted tumor with or without AMF exposure once a day every other day for a total of three treatments not only inhibited the growth of the primary transplant but also prevented the growth of the secondary, re-challenge transplant. The heat-generated therapeutic effect was more significant at a temperature of 43°C than either 41°C or 46°C. NPrCAP/M with AMF exposure, instead of control magnetite alone or without AMF exposure, resulted in the most significant growth inhibition of the re-challenge tumor and increased the life span of the mice. HSP70 production was greatest at 43°C compared to that with 41°C or 46°C. CD8+T cells were infiltrated at the site of the re-challenge melanoma transplant

Successful Resuscitation from Ventricular Fibrillation during Jogging in a Young Patient with Hypertrophic Cardiomyopathy

A 15-year-old girl, who was previously in good health, suddenly collapsed while jogging. Immediate cardiopulmonary resuscitation (CPR) was initiated, and she arrived at our hospital 13 minutes later. The ventricular fibrillation (VF) on admission was reverted to sinus rhythm 18 minutes after collapse by the second cardioversion. The echocardiogram revealed hypertrophic nonobstructed cardiomyopathy (HNOCM), although the 24hr ambulatory electrocardiographic, electrophysiologic and exercise stress tests could not define the exact cause of VF. Exercise-induced ischemia with sustained mild hypokalemia was suspected to be the cause of VF. The patient recovered consciousness three days after admission, and followed an uneventful course of treatment with oral atenolol not associating with disabling neurological deficit. Immediate basic life support and delivery of automatic external defibrillator on the spot is needed to rescue patients with out-of-hospital cardiac arrest

N-Propionyl-Cysteaminylphenol-Magnetite Conjugate (NPrCAP/M) Is a Nanoparticle for the Targeted Growth Suppression of Melanoma Cells

A magnetite nanoparticle, NPrCAP/M, was produced for intracellular hyperthermia treatment of melanoma by conjugating N-propionyl-cysteaminylphenol (NPrCAP) with magnetite and used for the study of selective targeting and degradation of melanoma cells. NPrCAP/M, like NPrCAP, was integrated as a substrate in the oxidative reaction by mushroom tyrosinase. Melanoma, but not non-melanoma, cells incorporated larger amounts of iron than magnetite from NPrCAP/M. When mice bearing a B16F1 melanoma and a lymphoma on opposite flanks were given NPrCAP/M, iron was observed only in B16F1 melanoma cells and iron particles (NPrCAP/M) were identified within late-stage melanosomes by electron microscopy. When cells were treated with NPrCAP/M or magnetite and heated to 43°C by an external alternating magnetic field (AMF), melanoma cells were degraded 1.7- to 5.4-fold more significantly by NPrCAP/M than by magnetite. Growth of transplanted B16 melanoma was suppressed effectively by NPrCAP/M-mediated hyperthermia, suggesting a clinical application of NPrCAP/M to lesional therapy for melanoma. Finally, melanoma cells treated with NPrCAP/M plus AMF showed little sub-G1 fraction and no caspase 3 activation, suggesting that the NPrCAP/M-mediated hyperthermia induced non-apoptotic cell death. These results suggest that NPrCAP/M may be useful in targeted therapy for melanoma by inducing non-apoptotic cell death after appropriate heating by the AMF

Exome sequencing of senescence-accelerated mice (SAM) reveals deleterious mutations in degenerative disease-causing genes

Background: Senescence-accelerated mice (SAM) are a series of mouse strains originally derived from unexpected crosses between AKR/J and unknown mice, from which phenotypically distinct senescence-prone (SAMP) and -resistant (SAMR) inbred strains were subsequently established. Although SAMP strains have been widely used for aging research focusing on their short life spans and various age-related phenotypes, such as immune dysfunction, osteoporosis, and brain atrophy, the responsible gene mutations have not yet been fully elucidated. Results: To identify mutations specific to SAMP strains, we performed whole exome sequencing of 6 SAMP and 3 SAMR strains. This analysis revealed 32,019 to 38,925 single-nucleotide variants in the coding region of each SAM strain. We detected Ogg1 p.R304W and Mbd4 p.D129N deleterious mutations in all 6 of the SAMP strains but not in the SAMR or AKR/J strains. Moreover, we extracted 31 SAMP-specific novel deleterious mutations. In all SAMP strains except SAMP8, we detected a p.R473W missense mutation in the Ldb3 gene, which has been associated with myofibrillar myopathy. In 3 SAMP strains (SAMP3, SAMP10, and SAMP11), we identified a p.R167C missense mutation in the Prx gene, in which mutations causing hereditary motor and sensory neuropathy (Dejerine-Sottas syndrome) have been identified. In SAMP6 we detected a p.S540fs frame-shift mutation in the Il4ra gene, a mutation potentially causative of ulcerative colitis and osteoporosis. Conclusions: Our data indicate that different combinations of mutations in disease-causing genes may be responsible for the various phenotypes of SAMP strains.ArticleBMC GENOMICS. 14:248 (2013)journal articl

Discovery of a Long-duration Superflare on a Young Solar-type Star EK Draconis with Nearly Similar Time Evolution for H alpha and White-light Emissions

Young solar-type stars are known to show frequent "superflares, " which may severely influence the habitable worlds on young planets via intense radiation and coronal mass ejections. Here we report an optical spectroscopic and photometric observation of a long-duration superflare on the young solar-type star EK Draconis (50-120 Myr age) with the Seimei telescope and Transiting Exoplanet Survey Satellite. The flare energy 2.6 x 10³⁴ erg and white-light flare duration 2.2 hr are much larger than those of the largest solar flares, and this is the largest superflare on a solar-type star ever detected by optical spectroscopy. The H alpha emission profile shows no significant line asymmetry, meaning no signature of a filament eruption, unlike the only previous detection of a superflare on this star. Also, it did not show significant line broadening, indicating that the nonthermal heating at the flare footpoints is not essential or that the footpoints are behind the limb. The time evolution and duration of the H alpha flare are surprisingly almost the same as those of the white-light flare, which is different from general M-dwarf (super-)flares and solar flares. This unexpected time evolution may suggest that different radiation mechanisms than general solar flares are predominant, such as: (1) radiation from (off-limb) flare loops and (2) re-radiation via radiative back-warming, in both of which the cooling timescales of flare loops could determine the timescales of H alpha and white light