感染予防からみた緑茶の特性に関する研究

We investigated the infection-preventive characteristics of Japanese green tea (middle grade) in reference to itscatechin (CAT) concentration. Colorimetric analysis showed that CAT was extracted most effectively at 80℃. When green tea extract (GTE) was prepared from the same green tea leaves (5g/80ml water) repeatedly six times at 80℃ for 1 min, almost the 2/3 of total CAT content was extracted during the first three extractions in which the second extraction gave the highest CAT concentration. Therefore, GTE prepared under this condition (5g/80ml water at 80℃ for 1 min) was referred to as standard GTE (SGTE) in this study. Bacteriological studies using Staphylococcus aureus, Escherichiac oli and Pseudomonas aeruginosa showed that the maximum inhibitory and bactericidal dilutions of the second SGET were ranged in 8-and4-fold dilutions, corresponding to 0.33mg/ml and 0.68mg/ml CAT concentrations, respectively, against either bacterial species and the differences between these two values were within 2-fold dilutions, indicating that SGTE shows the bactericidal activity. However, SGTE required as long as 4 to 5 h for bactericidal time in sharp contrast to iodine with that of as short as 1 min. When SGTE with CAT concentration ranging 1.2 mg/ml to 2.7mg/ml was incubated with influenza A/Aichi virus at 37℃ for at least 30min, SGTE also completely inhibited viral hemagglutination (HA) activity essential for the viral attachment to cell surface. The CAT-deficient SGTE, prepared by the treatment with FeCl_3, could not show both bactericidal and HA inhibitory activities, confirming that CAT in GTE is mainly responsible for these activities. In summary, GTE might be taken as a beneficial herbal medicine to promote the infection-safety conditions in the patients. However, on the application of GTE, its advantage/disadvantage and presence of sufficient CAT concentration should betightly recognized.緑茶（煎茶）の抗菌性とインフルエンザウイルス赤血球凝集（HA）活性阻害の特性を検証した．酒石酸鉄比色法による検討から，低温域（50℃と65℃）より高温域（80℃と91℃）でより多くカテキン（CAT）は抽出され，就中80℃が最大CAT量を示した．5g茶葉/80ml水，80℃，1分（標準緑茶液:SGTE）で６回抽出したところ，２回目で最高CAT量（2.7mg/ml）を示し，３回目までにほぼその2/3が抽出された．黄色ブドウ球菌，大腸菌と緑膿菌に対するSGTEの最大発育阻止と最大殺菌希釈度の差は，どの菌に対しても２倍以下であり，緑茶は，広範囲性かつ殺菌的作用を示すことが確認された．但し，ヨード液の１分に比べ，殺菌時間は４～５時間と極めて長いことが注目された．種々CAT量を有するSGTEを，種々時間37℃でインフルエンザウイルスと接触させたところ，CAT量1.2mg/ml～2.7mg/mlの範囲で，30分接触で完全にHA活性を阻害した．さらに，塩化第二鉄処理によるCAT除去SGTEには，抗菌作用も抗HA作用もないことから，種々ある緑茶成分のうち，CATが主な有効成分であることが示された．これらから，緑茶を感染予防として活用する際には，遅効性であること，また十分量なCAT含有（少なくとも1mg/ml）ことの認識は重要であると思われた

Role of the Transplant Pharmacist

At the National Cerebral and Cardiovascular Center, Japan, pharmacists have been involved in drug treatment management and patient care as members of multidisciplinary heart transplant teams that include surgeons, physicians, recipient transplant coordinators, and nurses during the waiting period for heart transplantation (HTx), HTx surgery, and post-HTx. During the waiting period, pharmacists play an important role in adjusting the use of antibiotics, anticoagulants, and antiarrhythmics by patients receiving a ventricular assist device (VAD). During HTx surgery and post-HTx, pharmacists advise physicians regarding the individualized medication protocol for immunosuppression and infection prevention to be used for each patient based on the patient’s pre-HTx characteristics as well as gene polymorphisms. They thus contribute to reducing the burden on the physician through the sharing of tasks. Throughout all three phases of HTx, pharmacists repeatedly provide medication and adherence education to the patients and caregivers. It is hoped that an academic society-led training protocol as well as transplant pharmacists will be established in Japan and other developed countries, and that these specialized transplant pharmacists would then provide individualized pharmacotherapy for the use of various antibiotics, anticoagulants, and immunosuppressive agents that have a narrow range of treatment in VAD and HTx patients

Development and Evaluation of a Novel 99mTc-Labeled Annexin A5 for Early Detection of Response to Chemotherapy

99mTc-HYNIC-annexin A5 can be considered as a benchmark in the field of apoptosis imaging. However, 99mTc-HYNIC-annexin A5 has characteristics of high uptake and long retention in non-target tissues such as kidney and liver. To minimize this problem, we developed a novel 99mTc-labeled annexin A5 using a bis(hydroxamamide) derivative [C3(BHam)2] as a bifunctional chelating agent, and evaluated its usefulness as an imaging agent for detecting apoptosis. The amino group of C3(BHam)2 was converted to a maleimide group, and was coupled to thiol groups of annexin A5 pretreated with 2-iminothiolane. 99mTc labeling was performed by a ligand exchange reaction with 99mTc-glucoheptonate. Biodistribution experiments for both 99mTc-C3(BHam)2-annexin A5 and 99mTc-HYNIC-annexin A5 were performed in normal mice. In addition, in tumor-bearing mice, the relationship between the therapeutic effects of chemotherapy (5-FU) and the tumor accumulation of 99mTc-C 3(BHam)2-annexin A5 just after the first treatment of 5-FU was evaluated. 99mTc-C3(BHam)2-annexin A5 was prepared with a radiochemical purity of over 95%. In biodistribution experiments, 99mTc-C3(BHam)2-annexin A5 had a much lower kidney accumulation of radioactivity than 99mTc-HYNIC- annexin A5. In the organs for metabolism, such as liver and kidney, radioactivity after the injection of 99mTc-HYNIC-annexin A5 was residual for a long time. On the other hand, radioactivity after the injection of 99mTc-C3(BHam)2-annexin A5 gradually decreased. In therapeutic experiments, tumor growth in the mice treated with 5-FU was significantly inhibited. Accumulation of 99mTc-C 3(BHam)2-annexin A5 in tumors significantly increased after 5-FU treatment. The accumulation of radioactivity in tumor correlated positively with the counts of TUNEL-positive cells. These findings suggest that 99mTc-C3(BHam)2-annexin A5 may contribute to the efficient detection of apoptotic tumor response after chemotherapy

Lipopolysaccharide-Deficient Mutants of Salmonella enterica Have Increased Sensitivity to Catechins

Antimicrobial activity is one of the well-known biological characteristics of catechins, the main extract of green tea leaves. It is thought that catechins intercalate into the bacterial cell membrane and damage the lipid bilayer. However, the association between catechins and lipopolysaccharides, which consist of an O side chain, core oligosaccharide, and lipid A, has not been previously investigated. In this study, we evaluated the catechin sensitivity of Salmonella enterica mutants that lack the O side chain and have core oligosaccharides of different lengths. These rough mutants were more sensitive to catechins than a bacterial strain with intact lipopolysaccharide. We conclude that the O side chain and core oligosaccharide play an important role in protecting Gram-negative bacteria against the antimicrobial activity of catechins

Screening of Mild Cognitive Impairment Through Conversations With Humanoid Robots: Exploratory Pilot Study

BackgroundThe rising number of patients with dementia has become a serious social problem worldwide. To help detect dementia at an early stage, many studies have been conducted to detect signs of cognitive decline by prosodic and acoustic features. However, many of these methods are not suitable for everyday use as they focus on cognitive function or conversational speech during the examinations. In contrast, conversational humanoid robots are expected to be used in the care of older people to help reduce the work of care and monitoring through interaction. ObjectiveThis study focuses on early detection of mild cognitive impairment (MCI) through conversations between patients and humanoid robots without a specific examination, such as neuropsychological examination. MethodsThis was an exploratory study involving patients with MCI and cognitively normal (CN) older people. We collected the conversation data during neuropsychological examination (Mini-Mental State Examination [MMSE]) and everyday conversation between a humanoid robot and 94 participants (n=47, 50%, patients with MCI and n=47, 50%, CN older people). We extracted 17 types of prosodic and acoustic features, such as the duration of response time and jitter, from these conversations. We conducted a statistical significance test for each feature to clarify the speech features that are useful when classifying people into CN people and patients with MCI. Furthermore, we conducted an automatic classification experiment using a support vector machine (SVM) to verify whether it is possible to automatically classify these 2 groups by the features identified in the statistical significance test. ResultsWe obtained significant differences in 5 (29%) of 17 types of features obtained from the MMSE conversational speech. The duration of response time, the duration of silent periods, and the proportion of silent periods showed a significant difference (P<.001) and met the reference value r=0.1 (small) of the effect size. Additionally, filler periods (P<.01) and the proportion of fillers (P=.02) showed a significant difference; however, these did not meet the reference value of the effect size. In contrast, we obtained significant differences in 16 (94%) of 17 types of features obtained from the everyday conversations with the humanoid robot. The duration of response time, the duration of speech periods, jitter (local, relative average perturbation [rap], 5-point period perturbation quotient [ppq5], difference of difference of periods [ddp]), shimmer (local, amplitude perturbation quotient [apq]3, apq5, apq11, average absolute differences between the amplitudes of consecutive periods [dda]), and F0cov (coefficient of variation of the fundamental frequency) showed a significant difference (P<.001). In addition, the duration of response time, the duration of silent periods, the filler period, and the proportion of fillers showed significant differences (P<.05). However, only jitter (local) met the reference value r=0.1 (small) of the effect size. In the automatic classification experiment for the classification of participants into CN and MCI groups, the results showed 66.0% accuracy in the MMSE conversational speech and 68.1% accuracy in everyday conversations with the humanoid robot. ConclusionsThis study shows the possibility of early and simple screening for patients with MCI using prosodic and acoustic features from everyday conversations with a humanoid robot with the same level of accuracy as the MMSE

SN 2020uem: a Possible Thermonuclear Explosion within a Dense Circumstellar Medium. I. The Nature of Type IIn/Ia-CSM SNe from Photometry and Spectroscopy

We have performed intensive follow-up observations of a Type IIn/Ia-CSM supernova (SN IIn/Ia-CSM), 2020uem, with photometry, spectroscopy, and polarimetry. In this paper, we report on the results of our observations focusing on optical/near-infrared (NIR) photometry and spectroscopy. The maximum V -band magnitude of SN 2020uem is less than −19.5 mag. The light curves decline slowly with a rate of ∼0.75 mag/100 days. In the late phase (≳300 days), the light curves show accelerated decay (∼1.2 mag/100 days). The optical spectra show prominent hydrogen emission lines and broad features possibly associated with Fe-peak elements. In addition, the H α profile exhibits a narrow P-Cygni profile with an absorption minimum of ∼100 km s ^−1 . SN 2020uem shows a higher H α /H β ratio (∼7) than those of SNe IIn, which suggests a denser circumstellar medium (CSM). The NIR spectrum shows the Paschen and Brackett series with a continuum excess in the H and Ks bands. We conclude that the NIR excess emission originates from newly formed carbon dust. The dust mass ( M _d ) and temperature ( T _d ) are derived to be ( M _d , T _d ) ∼ (4−7 × 10 ^−5 M _⊙ , 1500–1600 K). We discuss the differences and similarities between the observational properties of SNe IIn/Ia-CSM and those of other SNe Ia and interacting SNe. In particular, spectral features around ∼4650 Å and ∼5900 Å of SNe IIn/Ia-CSM are more suppressed than those of SNe Ia; these lines are possibly contributed, at least partly, by Mg i ] and Na i , and may be suppressed by high ionization behind the reverse shock caused by the massive CSM