Study on the method to quantify viable bacterial cellson the surface of endotracheal suction catheters

気管内吸引カテーテルに付着した一般細菌の生菌数測定方法について,超音波法およびチューブミキサーによ攪拌法を用いて検討した｡まず,人工的に緑膿菌を付着させた気管内吸引カテーテルを超音波処理することにより生菌数を測定した｡その結果,処理時間が1分を経過すると生菌数は減少をはじめ経時的に減少傾向を示した｡一方,攪拌法では0.5分の処理をピーク値としてその後の減少傾向は認められなかった｡次に,在宅療養患者に使用したカテーテルをチューブミキサーで0.5分攪拌後,生菌数の測定を行った｡また,同じカテーテルを用いて走査型電子顕微鏡による観察を行った結果,画面上の細菌数の印象と生菌数の測定結果に矛盾はなかった｡これらのことから気管内吸引カテーテルに付着した一般細菌の生菌数測定方法として,生理食塩水に入れたカテーテルをチューブミキサーで攪拌する方法が有用であると考えられた｡As a method for the detection of viable bacteria attached to endotracheal suction catheters, we evaluated sonication and dissociation using a tube mixer. The catheter fragments with Pseudomonas aeruginosa PAO1 were treated by each of the two methods, and viable cells in the elutions were counted. The highest number of viable cells was observed at 0.5 min by either method. The viable cell count decreased when the sonication time exceeded 1 min, while only a slight decrease of viable cells was observed by using a tube mixer. The catheters used for patients receiving care at home were fragmented and treated by a tube mixer to detach bacteria, and viable cells were counted. Electron microscopy observation showed an association between the viable cell count and morphology of surfaces of the catheters. These results suggest that adequate removal of bacteria attached to endotracheal suction catheters is possible by agitating catheter fragments for 0.5 min in physiological saline using a tube mixer

Differential responses of normal human coronary artery endothelial cells against multiple cytokines comparatively assessed by gene expression profiles

AbstractEndothelial cells play an important role in terms of biological functions by responding to a variety of stimuli in the blood. However, little is known about the molecular mechanism involved in rendering the variety in the cellular response. To investigate the variety of the cellular responses against exogenous stimuli at the gene expression level, we attempted to describe the cellular responses with comprehensive gene expression profiles, dissect them into multiple response patterns, and characterize the response patterns according to the information accumulated so far on the genes included in the patterns. We comparatively analyzed in parallel the gene expression profiles obtained with DNA microarrays from normal human coronary artery endothelial cells (HCAECs) stimulated with multiple cytokines, interleukin-1β, tumor necrosis factor-α, interferon-β, interferon-γ, and oncostatin M, which are profoundly involved in various functional responses of endothelial cells. These analyses revealed that the cellular responses of HCAECs against these cytokines included at least 15 response patterns specific to a single cytokine or common to multiple cytokines. Moreover, we statistically extracted genes contained within the individual response patterns and characterized the response patterns with the genes referring to the previously accumulated findings including the biological process defined by the Gene Ontology Consortium (GO). Out of the 15 response patterns in which at least one gene was successfully extracted through the statistical approach, 11 response patterns were differentially characterized by representing the number of genes contained in individual criteria of the biological process in the GO only. The approach to dissect cellular responses into response patterns and to characterize the pattern at the gene expression level may contribute to the gaining of insight for untangling the diversity of cellular functions

Molecular mechanism of cerebral edema improvement via IL-1RA released from the stroke-unaffected hindlimb by treadmill exercise after cerebral infarction in rats

Cerebral edema following cerebral infarction can be severe and directly affect mortality and mobility. Exercise therapy after cerebral infarction is an effective therapeutic approach; however, the molecular mechanism remains unclear. Myokines such as interleukin-1 receptor antagonist (IL-1RA) are released during skeletal muscle contraction with effects on other organs. We hypothesized that myokine release during exercise might improve brain edema and confirmed the hypothesis using transient middle cerebral artery occlusion (tMCAO) model rats. Rats subjected to tMCAO were divided according to the severity of illness and further assigned to exercise and non-exercise groups. Treadmill exercises were performed at a speed of 2–8 m/min for 10 min from 1–6 days post-reperfusion after tMCAO. Exercise significantly reduced edema and neurological deficits in severely ill rats, with a reduction in aquaporin-4 (AQP4) expression in the ischemic core and increased blood IL-1RA release from the stroke-unaffected hindlimb muscle after tMCAO. Administration of IL-1RA into the lateral ventricles significantly reduced edema and AQP4 expression in the ischemic core. In conclusion, treadmill exercise performed in the early phase of stroke onset alleviated the decrease in blood IL-1RA following ischemic stroke. IL-1RA administration decreased astrocytic AQP4 expression in the ischemic core, suppressing brain edema.Gono R., Sugimoto K., Yang C., et al. Molecular mechanism of cerebral edema improvement via IL-1RA released from the stroke-unaffected hindlimb by treadmill exercise after cerebral infarction in rats. Journal of Cerebral Blood Flow and Metabolism, 43(5), 812-827. © 2023 SAGE Publishing. DOI: 10.1177/0271678X231151569

魚介類に存在する生理活性リン脂質 : 多価不飽和脂肪酸含有コリングリセロリン脂質の過酸化との関連

Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a potent bioactive lipid that is formed enzymatically in various mammalian cells and tissues. We found that high PAF activities in lipid extracts from fishes. Recently, Tanaka et al. reported that novel phospholipids with an sn-2-short-chain acyl groups, having PAF-like bioactivities, were produced by lipid peroxidation of CGP (cholineglycerophospholipid) with an sn-2-polyunsaturated fatty acyl (PUFA) group. Therefore, we wondered whether the bioactive phospholipids in lipid extract from fishes were formed by lipid peroxidation. We extracted and prepared lipids with and without an anti-oxidant BHT from the tissues of various kinds of fishes and shellfishes. The lipid extract containing PAF-like compound that was purified by thin-layer chromatography induced the aggregation of washed rabbit platelets, and the activities were inhibited by PAF receptor antagonist, WEB-2086. Fishes which had high PAF-like activities were abundant in CGP with PUFA. In the case of lipid preparations without BHT, increase in PAF-like activities and TBARS (thiobarbituric acid-reactive substances) values, and decrease in PUFA content in CGP were observed. Furthermore, we peroxidized CGPs derived from various fishes and shellfishes, and PAF-like biological activities were measured by platelet aggregation. Investigations of the correlation between the PAF-like activities produced by peroxidation of PUFA containing CGP and the contents of PUFA and alkyl ether-linked subclass in parent CGPs, revealed that higher activities were produced by peroxidation of alky-PUFA CGP species, that were rich in alkyl ether-linked subclass and/or rich in docosahexaenoate (DHA). These results suggest that the lipids having PAF-like biological activities in fishes and shellfishes were produced by peroxidation of PUFA containing CGP

Inactivation of the Influenza Virus by a Supplemental Fermented Plant Product (Manda Koso)

Manda Koso is a commercial fermented plant product (FPP) made from 53 types of fruits and vegetables that are fermented for more than 3 years. We hypothesized that the FPP can prevent infection by influenza virus and human norovirus. Therefore, we investigated the effects of the FPP on influenza virus and feline calicivirus, a surrogate of human norovirus. We found that 10% FPP inactivated the influenza virus but not the feline calicivirus. Inhibition of the influenza virus was highly concentration-dependent: 1% and 0.3% FPP showed reduced inactivation efficacy. The effects of the FPP on the influenza virus-infected cells were investigated by addition of the FPP to the culture medium after virus infection. No suppressive effect of the FPP on influenza replication in MDCK cells was observed. The results showed that the FPP could inactivate influenza virus by affecting the virus particles

The MASCOT Magnetometer

The Mobile Asteroid Scout (MASCOT) is a small lander on board the Hayabusa2 mission of the Japan Aerospace Exploration Agency to the asteroid 162173 Ryugu. Among the instruments on MASCOT is a fluxgate magnetometer, the MASCOT Magnetometer (MasMag). The magnetometer is a lightweight ( ∼280 g∼280 g ) and low power ( ∼0.5 W∼0.5 W ) triaxial fluxgate magnetometer. Magnetic field measurements during the landing period and during the surface operational phase shall provide information about any intrinsic magnetic field of the asteroid and its remanent magnetization. This could provide important constraints on planet formation and the thermal and aqueous evolution of primitive asteroids.Thomas F. PetersonUnited States. National Aeronautics and Space Administration. Emerging Worlds Progra

Giant Pulsations Excited by a Steep Earthward Gradient of Proton Phase Space Density: Arase Observation

AbstractWe present observational evidence of drift resonance between westward propagating odd mode standing ultralow frequency waves and energetic protons. Compressional ∼13 mHz (Pc4 band) waves and proton flux oscillations at >50 keV were detected at ∼03 hr magnetic local time by the Arase satellite on 15 April 2017. The azimuthal wave number (m number) is estimated to be ∼−50 from ground observations, while the theory of drift resonance gives m ∼− 49 for odd mode waves and ∼110‐keV protons, providing evidence that the drift resonance indeed took place in this event. We also found a steep earthward gradient of proton phase space density, which can quantitatively explain the wave excitation. The observed waves show typical features of giant pulsations (Pgs), regarding local time, m number, and flux oscillations. This study, therefore, has great implications to the field line mode structure and excitation mechanism of Pgs