Search

Background Blood pressure (BP) monitoring with arterial waveform display requires an arterial cannula. We evaluated a new noninvasive device, Vasotrac (Medwave, Arden Hills, MN) that provides BP measurements approximately every 12-15 beats and displays pulse rate and a calibrated arterial waveform for each BP measurement. Methods Surgical and critically ill patients (n = 80) served as subjects for the study. BPs, pulse waveforms, and pulse rates measured via a radial artery catheter were compared with those obtained by the Vasotrac from the opposite radial artery. Data were analyzed to determine agreement between the two systems of measurement. Results Blood pressure measured noninvasively by the Vasotrac demonstrated excellent correlation (P Conclusions In surgical and critically ill patients, the Vasotrac measured BP, pulse rate, and displayed radial artery waveform, which was similar to direct radial arterial measurements. It should be a suitable device to measure BP frequently in a noninvasive fashion.

Background Nitrous oxide limits intraoperative hypothermia because the vasoconstriction threshold with nitrous oxide is higher than with equi-minimum alveolar concentrations of sevoflurane or isoflurane, presumably because of its stimulating actions on the sympathetic nervous system. Xenon, in contrast, does not cause sympathetic activation. Therefore, the authors tested the hypothesis that the vasoconstriction threshold during xenon-isoflurane anesthesia is less than during nitrous oxide-isoflurane anesthesia or isoflurane alone. Methods Fifteen patients each were randomly assigned to one of three 1-minimum alveolar concentration anesthetic regimens: (1) xenon, 43% (0.6 minimum alveolar concentration) and isoflurane, 0.5% (0.4 minimum alveolar concentration); (2) nitrous oxide, 63% (0.6 minimum alveolar concentration) and isoflurane 0.5%; or (3) isoflurane, 1.2%. Ambient temperature was maintained near 23 degrees C and the patients were not actively warmed. Thermoregulatory vasoconstriction was evaluated using forearm-minus-fingertip skin temperature gradients. A gradient exceeding 0 degrees C indicated significant vasoconstriction. The core-temperature threshold that would have been observed if skin had been maintained at 33 degrees C was calculated from mean skin and distal esophageal temperatures at the time of vasoconstriction. Results The patients' demographic variables, preinduction core temperatures, ambient operating room temperatures, and fluid balance were comparable among the three groups. Heart rates were significantly less during xenon anesthesia than with nitrous oxide. The calculated vasoconstriction threshold was lowest with xenon (34.6+/-0.8 degrees C, mean +/- SD), intermediate with isoflurane alone (35.1+/-0.6 degrees C), and highest with nitrous oxide (35.7+/-0.6 degrees C). Each of the thresholds differed significantly. Conclusions Xenon inhibits thermoregulatory control more than isoflurane, whereas nitrous oxide is the least effective in this respect.

We tested the hypothesis that once thermoregulatory vasoconstriction is triggered at a given core temperature during isoflurane anesthesia, redilation starts at a substantially higher core temperature. To avoid direct perception of cutaneous cooling and warming, we used epidural anesthesia and limited our thermal manipulations to the blocked area. Seven volunteers were anesthetized with isoflurane/epidural anesthesia (approximately T9 dermatomal level). Core hypothermia was induced by surface cooling restricted to the legs. Cooling was continued until fingertip blood flow suddenly decreased (vasoconstriction threshold). The core was then rewarmed by heating the legs until fingertip flow suddenly increased toward initial values (redilation threshold). The difference between the two thresholds defined the direction-dependent hysteresis. Vasoconstriction occurred at 35.2 +/- 0.6 degrees C and vasodilation at 36.2 +/- 0.5 degrees C (P < 0.01, paired t-test); consequently, the hysteresis was 1.0 +/- 0.6 degrees C. The observed hysteresis suggests that thermoregulatory responses during combined isoflurane/epidural anesthesia are not determined simply by instantaneous thermal input to central controllers, but may also depend on the direction of core temperature change.

褐色細胞腫摘出手術17症例における糖代謝と術後低血糖発作に関して解析を行なった. 17症例中11例 (65%) に術前, 糖尿病状態が存在した. 術後に低血糖発作を生じた例は17症例中2例の12%であり, すべてが術前には耐糖能異常を呈していた. 周術期におけるインスリン, C-ペプタイド, 血糖の測定から, 褐色細胞腫摘出直後にカテコラミンの急激な減少によると思われるインスリンの反跳性分泌〓進が認められることがわかり, これが低血糖発作を引き起こす原因と考えられた. 従って, 褐色細胞腫の手術においては, 血糖値の測定と糖液の投与が, 循環管理と同様に重要な点である.

Parker's method of delayed fluorescence as a means of determining the S * —T transition probability Φ ST was extended to systems in which reversible triplet energy transfer occurs between donor and acceptor. The Φ ST values of proflavine, acriflavine and acridine orange in ethanol were determined by this extended method using anthracene or 9-methylanthracene as an acceptor and eosine as a reference donor. The Φ ST values thus obtained are 0.45 ± 0.05 (proflavine), 0.53 ± 0.07 (acriflavine) and 0.30 ± 0.05 (acridine orange). The Φ ST values of eosine and thiopyronine were also determined by the method in Parker's original form using perylene as an acceptor and erythrosine as a reference donor. The Φ ST values obtained, 0.44 ± 0.01 (eosine) and 0.24 (thiopyronine), agree satisfactorily with those obtained by a chemical method, 0.43 ± 0.04 (eosine) and 0.28 ± 0.03 (thiopyronine).

Methylene blue active substance (MBAS), COD, Cl- and NH3-N concentrations in the water of the Tama River were measured at 4 points along the river and 1 point at the Nogawa (the branch of the Tama River).The results show that the MBAS concentration has been increasing continuously, and the correlations are found between MBAS and Cl-, and MBAS and NH3-N concentrations.The existence ratio of linear alkylate sulfonate (LAS) to branched chain alkylbenzene sulfonate (ABS) was measured using infrared spectroscopy. This ratio was found to be 15 : 85 and 20 : 80 at 2 points of the Tama River, and 25 : 75 at the Nogawa.

Purpose It has been reported that recently developed circulating-water garments transfer more heat than a forced-air warming system. The authors evaluated the hypothesis that circulating-water leg wraps combined with a water mattress better maintain intraoperative core temperature ≥36°C than either forced-air warming or carbon-fiber resistive heating during major abdominal surgery. Methods Thirty-six patients undergoing open abdominal surgery were randomly assigned to warming with: (1) circulating-water leg wraps combined with a full-length circulating-water mattress set at 42°C, (2) a lower-body forced-air cover set on high (≈43°C), and (3) a carbon-fiber resistive-heating cover set at 42°C. Patients were anesthetized with general anesthesia combined with continuous epidural analgesia. The primary outcome was intraoperative tympanic-membrane temperature ≥36°C. Results In the 2 h after anesthesia induction, core temperature decreased 1.0 ± 0.5°C in the forced-air group, 0.9 ± 0.2°C in the carbon-fiber group, and 0.4 ± 0.4°C in the circulating-water leg wraps and mattress group (P

Purpose The first purpose of this study was to determine the incidence of postoperative nausea and/or vomiting (PONV) 0–48 h after anesthesia at a Japanese cancer center. The second purpose of this study was to collect information on PONV risk factors, independently, in the categories of patient-related, anesthesia-related, and surgery-related factors. Methods The frequency of nausea and vomiting was prospectively investigated from 0 to 48 h after anesthesia in 1645 patients (11–94 years of age) at a single medical institution. The occurrence of nausea and vomiting and the use of antiemetics were recorded up to 48 h after anesthesia. Patient-related, anesthesia-related, and surgery-related factors were also recorded and submitted to multiple logistic regression analysis to determine the relationship of these factors to nausea and vomiting. Results The incidences of nausea and vomiting from 0 to 24 h after anesthesia were 40 and 22 %, respectively. The incidences 24–48 h after anesthesia were 10 and 3 %, respectively. Female sex, previous history of PONV, prolonged anesthesia, and remifentanil use during surgery were identified as risk factors for both nausea and vomiting. The use of a volatile anesthetic, use of fentanyl during surgery, postoperative use of opioids, nonsmoking status, and drinking alcohol on 4 or fewer days per week were identified as risk factors for nausea alone. Conclusion The incidence of and risk factors for PONV at a Japanese cancer center according to this study are comparable to those reported elsewhere.

Studies of the morphology of Escherichia coli showed that these bacilli when infected with RNA phage Qβ in broth containing hypertonic sucrose and Mg2+ formed osmotically labile spherical cells or spheroplasts. Phage-induced spheroplasts readily released their burst of phage when diluted into ordinary culture broth without sucrose. Investigation of the mechanism of host cell lysis revealed that incorporation of [3H]diaminopimelic acid (DAP) into the mucopeptide layer of the cell wall was markedly inhibited starting at about the midpoint of the phage replication cycle. The major site of inhibition is the DAP-containing mucopeptide layer since the synthesis of the lipoprotein-lipopolysaccharide layer, making up the bulk of the cell wall of E. coli, was not affected. A model for Qβ-mediated cell lysis is discussed which is analogous to penicillin-induced cell rupture.

Background Very few studies have investigated the blood flow velocity from the inferior vena cava (IVC) to the pulmonary artery following the Fontan operation using an extra-cardiac conduit (ECC). No studies at all have investigated the velocity immediately after the circulation is established. The purpose of this retrospective study was to find an acceptable flow velocity at the ECC following the completion of a total cavo-pulmonary connection (TCPC) via transesophageal echocardiography. Findings We measured the mean velocity (m-V) of the blood flow proximal to the anastomosis between the IVC and ECC in eight patients and compared the results with theoretically predicted values based on assumptions regarding the cardiac output, the ratio of the IVC flow to the superior vena cava flow, and the cross-sectional form of the ECC. Mean velocities ranging from about 15 to 60 cm/s were detected in the absence of any observable stenosis. The measured m-V was significantly faster than the predicted value in our study, both collectively and in every patient individually. The shrinking and compression of the ECC might account for the faster velocities measured in our cases. Conclusion The observed range of m-V at the ECC, about 15-60cm/s, may be acceptable for the establishment of TCPC circulation.

近年、様々な無機物沈殿ペプチドが開発され、ペプチド化学と無機化学を融合した材料工学分野への応用を指向した研究が注目されている。現在のペプチドを用いたミネラリゼーション研究においては、自己集合化により作製したペプチド集合体を無機物沈殿の鋳型として用い、無機ナノ構造体のサイズや形状の制御を試みている。しかしながら、ペプチドのナノレベルでの自己集合化の制御が難しいことに加え、一つの構造体につき一種類の無機物の沈殿しかできないことが問題となっている。そのため、高機能性の無機ナノ構造体を作製するためには複数の無機物のミネラリゼーションを達成することが不可欠であり、新たな作製手法が求められている。また、細胞内での応用を指向した場合、合成した無機ナノ粒子を細胞内に導入する方法では細胞膜に損傷を与えるほか、細胞内で凝集が生じて目的の機能が発現しないといった問題点がある。細胞内で無機ナノ粒子を直接合成できればこの問題点を解決することができ、合成した無機ナノ粒子を利用した応用展開が期待できる。そこで、本研究では以上の問題点を解決するために、人工ペプチドを用いたミネラリゼーションによる無機ナノ粒子作製法について一連の手法の確立に取り組んだ。まず、ペプチドを用いた無機物のミネラリゼーションの有用性評価では、Auの還元を題材に、それに関与するTrp残基の数を変化させることで、Auの還元速度を制御できることが示された。また、還元剤や分散保護剤を使用せずに高分散性および高触媒活性を有するAuナノ粒子を作製できることも示した。次に、核酸とペプチドを用いた無機物の精密沈殿制御法の確立を行った。具体的にはDNA上に無機物沈殿ペプチドを配置した複合体をテンプレートとすることで、DNA上の特定部位に複数種の無機物を位置特異的に沈殿させる手法を構築した。また、DNAに結合させる無機物沈殿ペプチドの数を変化させることで無機ナノ構造体中の元素含有比の制御、それに伴う機能の制御が可能であることを示した。最後に、細胞膜透過能と金属イオン結合能を有するペプチドを構築し、それに金属イオンを結合させて細胞内に導入して、無機ナノ粒子を直接合成する手法を確立した。これにより従来法では作製することができない金属イオンの濃度でのナノ粒子の作製や、形状の制御が可能となった。本研究を通して、ペプチドを用いたミネラリゼーションを題材とし、DNAや細胞内環境を利用することで、無機ナノ粒子作製法を確立することができた。本研究はペプチド科学における新しい概念を提示しており、ナノからバイオまで幅広い分野への応用が期待される。, 令和2年度(2020年度)