Characterization of Information-Transmitting Materials Produced in Ionic Liquid-based Neuromorphic Electrochemical Devices for Physical Reservoir Computing

Device implementation of reservoir computing, which is expected to enable high-performance data processing in simple neural networks at a low computational cost, is an important technology to accelerate the use of artificial intelligence in the real-world edge computing domain. Here, we propose an ionic liquid-based physical reservoir device (IL-PRD), in which copper cations dissolved in an IL induce diverse electrochemical current responses. The origin of the electrochemical current from the IL-PRD was investigated spectroscopically in detail. After operating the device under various operating conditions, X-ray photoelectron spectroscopy of the IL-PRD revealed that electrochemical reactions involving Cu, Cu2O, Cu(OH)2, CuSx, and H2O occur at the Pt electrode/IL interface. These products are considered information transmission materials in IL-PRD similar to neurotransmitters in biological neurons. By introducing the Faradaic current components due to the electrochemical reactions of these materials into the output signal of IL-PRD, we succeeded in improving the time-series data processing performance of the nonlinear autoregressive moving average task. In addition, the information processing efficiency in machine learning to classify electrocardiogram signal waveforms was successfully improved by using the output current from IL-PRD. Optimizing the electrochemical reaction products of IL-PRD is expected to advance data processing technology in society.

Dynamic Nonlinear Behavior of Ionic Liquid-Based Reservoir Computing Devices

Herein, a physical reservoir device that uses faradaic currents generated by redox reactions of metal ions in ionic liquids was developed. Synthetic time-series data consisting of randomly arranged binary number sequences ("1" and "0") were applied as isosceles-triangular voltage pulses with positive and negative voltage heights, respectively, and the effects of the faradaic current on short-term memory and parity-check task accuracies were verified. The current signal for the first half of the triangular voltage-pulse period, which contained a much higher faradaic current component compared to that of the second half of the triangular voltage-pulse period, enabled higher short-term memory task accuracy. Furthermore, when parity-check tasks were performed using a faradaic current generated by asymmetric triangular voltage-pulse levels of 1 and 0, the parity-check task accuracy was approximately eight times higher than that of the symmetric triangular voltage pulse in terms of the correlation coefficient between the output signal and target data. These results demonstrate the advantage of the faradaic current on both the short-term memory characteristics and nonlinear conversion capabilities and are expected to provide guidance for designing and controlling various physical reservoir devices that utilize electrochemical reactions.

Reservoir computing with dielectric relaxation at an electrode-ionic liquid interface

A physical reservoir device with tunable transient dynamics is strongly required to process time-series data with various timescales generated in the edge region. In this study, we proposed using the dielectric relaxation at an electrode–ionic liquid (IL) interface as the physical reservoir by making the most of designable physicochemical properties of ILs. The transient dynamics of a Au/IL/Au reservoir device were characterized as a function of the alkyl chain length of cations in the IL (1-alkyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide). By considering a weighted sum of exponentials expressing a superposition of Debye-type relaxations, the transient dynamics were well reconstructed. Although such complex dynamics governed by multiple relaxation processes were observed, each extracted relaxation time scales with a power law as a function of IL’s viscosity determined by the alkyl chain length of cations. This indicates that the relaxation processes are characterized by bulk properties of the ILs that obey the widely received Vogel-Fulcher-Tammann law. We demonstrated that the 4-bit time-series signals were transformed into the 16 classifiable data, and the data transformation, which enables to achieve higher accuracy in an image classification task, can be easily optimized according to the features of the input signals by controlling the IL’s viscosity.

Memristors With Controllable Data Volatility by Loading Metal Ion-Added Ionic Liquids

We demonstrate a new memristive device (IL-Memristor), in which an ionic liquid (IL) serve as a material to control the volatility of the resistance. ILs are ultra-low vapor pressure liquids consisting of cations and anions at room temperature, and their introduction into solid-state processes can provide new avenues in electronic device fabrication. Because the device resistance change in IL-Memristor is governed by a Cu filament formation/rupture in IL, we considered that the Cu filament stability affects the data retention characteristics. Therefore, we controlled the data retention time by clarifying the corrosion mechanism and performing the IL material design based on the results. It was found out that the corrosion of Cu filaments in the IL was ruled by the comproportionation reaction, and that the data retention characteristics of the devices varied depending on the valence of Cu ions added to the IL. Actually, IL-Memristors involving Cu(II) and Cu(I) show volatile and non-volatile nature with respect to the programmed resistance value, respectively. Our results showed that data volatility can be controlled through the metal ion species added to the IL. The present work indicates that IL-memristor is suitable for unique applications such as artificial neuron with tunable fading characteristics that is applicable to phenomena with a wide range of timescale.

Corrugation of an unpaved road surface under vehicle weight

Road corrugation refers to the formation of periodic, transverse ripples on unpaved road surfaces. It forms spontaneously on an initially flat surface under heavy traffic and can be considered to be a type of unstable growth phenomenon, possibly caused by the local volume contraction of the underlying soil due to a moving vehicle's weight. In the present work, we demonstrate a possible mechanism for road corrugation using experimental data of soil consolidation and numerical simulations. The results indicate that the vertical oscillation of moving vehicles, which is excited by the initial irregularities of the surface, plays a key role in the development of corrugation.

Metal cation-exchanged zeolites with the location, state, and size of metal species controlled

Rh ion-exchanged MFI-type aluminosilicate zeolites with different Al distributions were prepared for controlling the location, state, and size of Rh species. The MFI-type aluminosilicate zeolite with the framework Al atoms predominantly located inside the channel intersections leads to the formation of relatively large Rh species, which were confirmed by ultraviolet-visible (UV-vis) and infrared (IR) spectroscopies. Moreover, this catalyst showed a high catalytic activity for the oxidative reforming reaction of methane.

Three-Dimensional Nanoconfinement Supports Verwey Transition in Fe3O4 Nanowire at 10 nm Length Scale

Herein, we construct three-dimensional (3D) Fe₃O₄ epitaxial nanowires at a 10 nm length scale on a 3D MgO nanotemplate using an original nanofabrication technique that mainly comprises nanoimprint lithography and inclined thin-film deposition. Despite the high density of inevitable nanoscale defects, the ultrasmall Fe₃O₄ nanowires exhibit a prominent Verwey transition at about 112 K with a maximum relative change in resistance of 9.5, which is 6 times larger than that of the thin-film configuration. Numerous measurements on a large number of Fe₃O₄ nanowires grown concurrently on the same 3D MgO nanotemplate reveal a dramatic difference in their electrical transport property with the presence/absence of the Verwey transition. A comparative study of Fe₃O₄ wires of increasing volume and a thin film reveals that a profound change in the Verwey transition is observed only for wires with a volume on the order of 10 nm³. Moreover, a significant decrease in the sharpness of the resistance jump and the transition temperature of the Verwey response is noticed with an increasing volume of Fe₃O₄. This indicates the potency of the 3D nanofabrication technique in controlling nanoscale defects, which is further reconfirmed through magnetoresistance measurement. A feature of the magnetoresistance curve identifies the antiphase boundaries as a major source of defects. The occurrence of the smallest magnetoresistance in the ultrasmall nanowire with the highest Verwey transition temperature and resistance change ratio proves that 3D isotropic spatial confinement into a length scale comparable to the average spacing between two antiphase boundaries enables the favorable control over nanoscale defects. A simple statistical model satisfactorily illustrates the dependence of electrical transport properties on the volume of Fe₃O₄ from the macroscale down to the nanoscale. Finally, an ultrasmall nanowire with a low defect concentration allows the estimation of the true coherence length of the fundamental quasiparticle, the trimeron, responsible for the Verwey transition.

Isolation and Characterization of jararaca GPIb-BP, a Snake Venom Antagonist Specific to Platelet Glycoprotein lb

A platelet glycoprotein lb-binding protein (GPIb-BP) was isolated from the snake venom of Bothrops jararaca. Jararaca GPIb-BP showed a single band with Mr of 30,000, and two distinct bands with Mr. of 17,000/13,000 under non-reducing and reducing conditions, respectively, on SDS-polyacrylamide gel electrophoresis. Jararaca GPIb-BP itself induced neither platelet aggregation nor serotonin release from platelets, but specifically bound to GPIb (40,629 ± 2,521 molecules per normal platelet, with Kd 39.1 ± 2.4 nM at saturation). The purified venom protein completely inhibited ristocetin- or botrocetin-induccd von Willebrand factor (vWF) binding, and blocked the bovine vWF binding to GPIb, with IC50 values ranging from 28 to 42 nM, without affecting the platelet aggregation induced by ADP or α-thrombin. 1251-jararaca GPIb-BP binding to GPIb was not altered by the presence of human α-thrombin. Jararaca GPIb-BP at a final concentration of 104 nM totally abolished vWF-dependent shear- induced platelet aggregation (SIPA) at a high shear stress, but had no effect on SIPA at a low shear stress. Reduced and S-carboxyamidomethylated jararaca GPIb-BP lost its inhibitory activity on SIPA. The NH2-terminal amino acid sequences of the subunits revealed a high degree of homology with those of several Ca2+-dependent lectins, especially to those of two functionally opposite venom proteins, botrocetin (a vWF-modulator) and alboaggregin-B (a GPIb- modulator).

Abstract P6-07-03: Long non-coding RNA H19 promotes cancer stemness and worsen breast cancer survival

Background: Cancer stem cells (CSC) are good sources of tumor initiation, heterogeneity, progression, and metastasis because of their unique characteristics. Several potential markers for CSCs have been suggested for breast cancer, including CD44+/CD24−/low, aldehyde dehydrogenase 1 (ALDH1), and epithelial cell adhesion molecule/epithelial-specific antigen. We previously reported that ALDH1 gene expression is related to aggressive phenotypes and poor prognosis in breast cancers. In this study, we conducted differential analysis of mRNA expression in ALDH1-positive breast cancer to identify genes associated with CSC. Next, we performed basic and clinical studies of one gene.

Methods: Messenger RNA was isolated from ALDH1-positive cells and ALDH1-negative cells in 5 ALDH1-positive breast cancers. Microarray analysis revealed that several genes were significantly associated with the ALDH1 gene. Among them, we examined a long non-coding RNA of H19 in this study. We evaluated the effect of H19 on CSCs using RNA interference and a sphere formation assay using two cell lines, HCC1937 and iCSCL10A cells. We also investigated H19 expression in 192 surgical specimens by in situ hybridization and analyzed the relationship between H19 expression and clinic pathological findings in breast cancer patients.

Results: Through in vitro experiments, we confirmed that suppression of H19 reduced sphere formation in both HCC1937 and iCSCL10A cells. Among surgical specimens, 48 samples (25%) expressed H19. We verified thatH19 positivity was significantly higher in ALDH1-positive cases than in ALDH1-negative cases (68% vs 9.7%, p < 0.001). H19 was significantly highly expressed in triple-negative breast cancer (TNBC) (46%) compared with other subtypes: luminal (33%), luminal-HER2 (6%), and HER2-enriched subtype (15%). H19-positive patients showed significantly worse prognosis (5-year disease-free survival 75.8% vs 91.5%, p = 0.001 and 5-year overall survival 88.7% vs 97.7%, p = 0.002). The effect of H19 expression on prognosis was the most significant in TNBC compared to in other subtypes (5-year disease-free survival 63.6% vs 88.9%, p = 0.038).

Conclusions: H19 is clearly associated with CSCs and correlated with poor prognosis in breast cancer patients, particularly TNBC. Our future studies will investigate the role of H19 in maintaining the nature of CSCs and protein-coding genes associated with H19.

Citation Format: Shima H, Kida K, Yamada A, Sugae S, Narui K, Miyagi Y, Ryo A, Ichikawa Y, Ishikawa T, Endo I. Long non-coding RNA H19 promotes cancer stemness and worsen breast cancer survival [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-07-03.

Catastrophic cellular events leading to complex chromosomal rearrangements in the germline

Although complex chromosomal rearrangements were thought to reflect the accumulation of DNA damage over time, recent studies have shown that such rearrangements frequently arise from 'all-at-once' catastrophic cellular events. These events, designated chromothripsis, chromoanasynthesis, and chromoanagenesis, were first documented in the cancer genome and subsequently observed in the germline. These events likely result from micronucleus-mediated chromosomal shattering and subsequent random reassembly of DNA fragments, although several other mechanisms have also been proposed. Typically, only one or a few chromosomes of paternal origin are affected per event. These events can produce intrachromosomal deletions, duplications, inversions, and translocations, as well as interchromosomal translocations. Germline complex rearrangements of autosomes often result in developmental delay and dysmorphic features, whereas X chromosomal rearrangements are usually associated with relatively mild clinical manifestations. The concept of these catastrophic events provides novel insights into the etiology of human genomic disorders. This review introduces the molecular characteristics and phenotypic outcomes of catastrophic cellular events in the germline.

Fabrication of sub-1 nm gap electrodes using metal-mask patterning and conductivity measurements of molecules in nanoscale spaces

Fabrications of sub-1 nm gap Au electrodes using a metal mask for patterning were achieved. Because the procedure does not involve wet processing, the ranges of possible electrode and substrate materials for the electrodes are greatly expanded.

Investigation of switching mechanism in HfOx-ReRAM under low power and conventional operation modes

Low-power resistive random access memory (LP-ReRAM) devices have attracted increasing attention owing to their advantages of low operation power. In this study, a vertical-type LP-ReRAM consisting of TiN/Ti/HfO2/TiN structure was fabricated. The switching mechanism for LP-ReRAM was elucidated as the conductive filament mechanism for conventional mode, and an interface-type switching mechanism for low power mode was proposed. The analysis of low frequency noise shows that power spectral density (PSD) is approximately proportional to 1/f for conventional operation mode. Nevertheless, for low power mode, the PSD of low resistance state (LRS) is proportional to 1/f, while that of high resistance state (HRS) is clear proportional to 1/f2. The envelope of multiple Lorentzian spectra of 1/f2 characteristics due to different traps reveals the characteristics of 1/f. For HRS of low power mode, a limited number of traps results in a characteristic of 1/f2. During the set process, the number of oxygen vacancies increases for LRS. Therefore, the PSD value is proportional to 1/f. Owing to the increase in the number of traps when the operation mode changes to conventional mode, the PSD value is proportional to 1/f. To the best of our knowledge, this is the first study that reveals the different noise characteristics in the low power operation mode from that in the conventional operation mode.

Novel synthesis process for solar-light-active porous carbon-doped CuO nanoribbon and its photocatalytic application for the degradation of an organic dye

A simple, one-step novel solution process was developed for the synthesis of carbon-doped CuO (C-CuO) nanoribbons without the use of a catalyst, template, substrate, or costly instrumentation at room temperature.

Simple synthesis process for ZnO sphere-decorated CNT fiber and its electrical, optical, thermal, and mechanical properties

An easy process to produce ZnO sphere-decorated CNT (ZSDC) fibers was established.

Construction of anα-Amylase/Glucoamylase Fusion Gene and Its Expression inSaccharomyces cerevisiae

A fusion gene which encoded a polypeptide comprised of 1116 amino acids was constructed using the alpha-amylase and glucoamylase cDNAs of Aspergillus shirousamii. When the fusion gene was expressed in Saccharomyces cerevisiae using a yeast expression plasmid under the control of the yeast ADH1 promoter, a bifunctional fusion protein (145 kDa) having both alpha-amylase and glucoamylase activities was secreted into the culture medium. The fusion protein had higher raw-starch-digesting activity than those of the original alpha-amylase and glucoamylase, and adsorbed onto raw starch like the glucoamylase. It was suggested that the characteristics are a result of the raw-starch-affinity site in the glucoamylase domain of the fusion protein.

Hierarchical three-dimensional layer-by-layer assembly of carbon nanotube wafers for integrated nanoelectronic devices

We report a general approach to overcome the enormous obstacle of the integration of CNTs into devices by bonding single-walled carbon nanotubes (SWNTs) films to arbitrary substrates and transferring them into densified and lithographically processable "CNT wafers". Our approach allows hierarchical layer-by-layer assembly of SWNTs into organized three-dimensional structures, for example, bidirectional islands, crossbar arrays with and without contacts on Si, and flexible substrates. These organized SWNT structures can be integrated with low-power resistive random-access memory.

Anomalous enhancement in the infrared phonon intensity of a one-dimensional uneven peanut-shaped C60 polymer

A one-dimensional (1D) uneven peanut-shaped C(60) polymer formed from electron-beam (EB)-induced polymerization of C(60) molecules showed an anomalous increase in two characteristic infrared (IR) peak intensities, which are respectively due to the radial and tangential motion of the 1D polymer, when compared to the IR peaks of pristine C(60) films. This anomaly was analyzed on the basis of the vibrational van Hove singularity (VHS), using an extended thin-shell elastic model fully considering the effects of periodic radius modulation inherent to the 1D uneven peanut-shaped C(60) polymer. We succeeded in explaining the enhancement in the tangential peak intensity by VHS, whereas the origin to cause that in the radial peak intensity is still unclear.

Applying computational nanomaterials design to the reactive ion etching of NiO thin films-a preliminary investigation

We have developed and proposed a model for reactive ion etching (RIE) process design of nickel oxide thin films using a computational materials design based on ab initio calculations. On etching NiO, we found that it was necessary to have hydrogen-based reactive gases in the initial state in order to enhance RIE (e.g. NH(3), CH(4)). We strongly suggest the use of CH(4) or any H-based gas source other than CHF(3) to enhance RIE process.

Phospho-regulation of human protein kinase Aurora-A: analysis using anti-phospho-Thr288 monoclonal antibodies

Mammalian Aurora-A is related to a serine/threonine protein kinase that was originally identified by its close homology with Saccharomyces cerevisiae Ipl1p and Drosophila melanogaster aurora that are key regulators in the orchestration of mitotic events. The protein level of Aurora-A, its peak kinase activity during mitosis, and its activation have been attributed to phosphorylation. Here we show that this enzyme is an arginine-directed kinase and define its substrate specificity. We also found that Thr288 within the activation loop is a critical residue for activating phosphorylation events in vitro and that it is spatiotemporally restricted to a brief window at mitosis on duplicated centrosomes and on spindle microtubules proximal to the poles in vivo. Immunodepletion assays indicated that an upstream kinase(s) of Aurora-A might exist in mammalian cells in addition to autophosphorylation. Furthermore, human activated Aurora-A forms complexes with the negative regulator protein serine/threonine phosphatase type 1 (PP1) that was negatively phosphorylated on Thr320. Interestingly, phospho-specific Aurora-A monoclonal antibodies restrain Aurora-A kinase activity in vitro, providing further therapeutic avenues to explore.

[New CT program simulating kidney displacement during retroperitoneal laparoscopic nephrectomy]

A total of 12 patients with malignant localized renal or ureteral neoplasms underwent multi-slice computed tomography. Imaging data were sent to the dedicated workstation to create volume rendering and virtual laparoscopic images of the kidney which was displaced ventrally with retroperitoneal balloon. These findings were compared with video images obtained during retroperitoneal laparoscopic nephrectomy. The kidney displacement simulator depicted all renal arteries (100% sensitivity) and 13 of 14 renal veins (93% sensitivity). Hilar anatomy, including the tumor, major vessels and their relationships were visualized as in the actual laparoscopic views. The desired portions of major vessels as well as the left adrenal and gonadal veins visualized with this system completely corresponded with the actual laparoscopic images during surgery. The kidney displacement simulator is useful to foresee desired portions of major vessels and branched small vessels such as the adrenal or gonadal veins in advance of surgery. It is thus able to guide surgeons and reduce operative risks and possible complications.

Sequential blood level monitoring of basiliximab during multisession plasmapheresis in a kidney transplant recipient

Basiliximab, a chimeric monoclonal antibody against the alpha chain of the interleukin-2 receptor (IL-2R) has been used in renal transplant patients. We monitored sequential blood concentrations of basiliximab in a patient who received a kidney transplant with basiliximab-based immunosuppression together with multiple sessions of plasmapheresis. A 34-year-old man received a living-related kidney transplant with induction immunosuppression including tacrolimus, mycophenolate, methylprednisolone, and basiliximab. Severe antibody-mediated acute rejection lead to a requirement for hemodialysis. Deoxyspergualin was administered for 10 days at a daily dose of 5 mg/kg combined with eight sessions of double filtration plasmapheresis (DFPP). After treatment, the serum creatinine returned to 0.95 mg/dL, and there were no major complications or infections. Sequential basiliximab blood levels of the patient were monitored following transplantation. The serum basiliximab concentration decreased by 72.4% after five consecutive DFPPs, and by 87.6% after eight DFPP sessions. The elimination rate of basiliximab (DeltaBLX) was 6.1% before DFPP, but increased over eight DFPPs to 20.5%. Serum basiliximab concentrations declined to 0.16 microg/mL on day 33, which is below the IL-2R saturation concentration (0.2 microg/mL). Multiple sessions of plasmapheresis using DFPP enhanced the elimination of serum basiliximab at an average elimination rate of 19.1%. In the patient reported on here, the serum basiliximab concentration fell to below the IL-2R saturation level (0.2 microg/mL) within 1 month of living-related kidney transplantation. We recommend that additional basiliximab infusions be considered for cases undergoing more than three plasmapheresis sessions.

Loss of Heterozygosity on Chromosome 10p14–p15 in Colorectal Carcinoma

High frequencies of loss of heterozygosity (LOH) on chromosome 10p14-p15 have been reported in various tumors, including gliomas, pulmonary carcinoid tumors and cervical, hepatic, prostatic and esophageal carcinomas. However, LOH on chromosome 10p14-p15 in colorectal tumors has not been reported. Therefore, we examined LOH on chromosome 10p14-p15 in 60 colorectal carcinomas (21 superficial and 39 advanced types) by microsatellite assay. Three microsatellite loci, D10S191 (10p14), D10S558 and D10S249 (10p15) were examined by polymerase chain reaction [early colorectal carcinomas, LOH of markers D10S191 (36%), D10S558 (7%) and D10S249 (11%), and in advanced colorectal carcinomas, LOH of markers D10S191 (20%), D10S558 (13%) and D10S249 (33%)]. There were no significant associations between LOH on chromosome 10p14-p15 and clinicopathologic features, including patient age, sex, tumor location, depth of invasion, histologic type, lymph node metastasis and prognosis. These data suggest that a putative tumor suppressor gene associated with colorectal carcinogenesis may be located on chromosome 10p14-p15 and that alteration of this gene may be involved in the development but not progression of colorectal tumors.

Combined Therapy of Deoxyspergualin and Plasmapheresis: A Useful Treatment for Antibody-Mediated Acute Rejection After Kidney Transplantation

Antibody-mediated acute rejection (AbAR) is one of the primary causes of graft impairment in kidney transplant recipients. Deoxyspergualin (DSG), which displays an antiproliferative action against antigen-stimulated B cells inhibiting antibody production, may be effective to rescue AbAR in combination with plasmapheresis by suppressing antibody production and elimination. In the present study, we report our experience with DSG/plasmapheresis therapy for the treatment of AbAR. Five kidney transplant patients experienced a steroid-resistant acute rejection requiring dialysis followed by an AbAR that was confirmed by biopsy and flow cytometry crossmatch (FCXM) results. DSG was administration at 3 mg/kg per day for 10 days with plasmapheresis reduce antidonor antibody. Treatment outcome, effectiveness, and adverse events were examined; in two cases sequential FCXM examinations were performed to evaluate antibody status. All five patients received DSG/plasmapheresis therapy. The number of plasmapheresis treatments ranged from 1 to 9 according to treatment outcomes. Four patients recovered graft function following treatment; whereas one showed no response to the treatment, and the graft was lost. No serious side effects or infections were observed during or after treatment. Monitoring of sequential FCXM correlated with the clinical course. AbAR shows a worse prognosis than cellular rejection. It is refractory to conventional antirejection therapy. In the present study, DSG/plasmapheresis therapy was effective in four of five patients (80%) with AbAR. It may be considered the first choice of treatment for cases of acute humoral rejection.

Treatment with β-SQAG9 prevents rat hepatic ischemia-reperfusion injury

BACKGROUND

Ischemia-reperfusion (I/R) injury occurs in various situations, including transplantation, trauma, and shock. We previously reported that the synthetic beta-SQDG (18:0), which was derived from sulfoquinovosyl diacylglycerol of the sea urchin, possessed immunosuppressive effects, such as inhibition of T-cell responses in human allogenic human mixed lymphocyte reactions (MLR) and skin allograft survival in rats. beta-SQAG9 was synthesized from beta-SQDG (18:0) to improve structural stability in aqueous solution with the same biological activities to bind to CD62L (L-selectin) and CD62P (P-selectin) in vitro. We hypothesized that beta-SQAG9 might attenuate leukocyte rolling on the endothelium and neutrophil infiltration in which L-selectin and P-selectin are key molecules. We investigated the protective effect of beta-SQAG9 against hepatic I/R injury.

METHODS

Male Lewis rats were divided into 6 groups: sham, control, and treatment. Rats in the control, and the treatment groups were subjected to hepatic ischemia for 30 minutes. They were injected with PBS or beta-SQAG9 at doses of 5, 10, 25, and 50 mg/kg into the penile vein immediately before reperfusion. To assess the damage to the hepatic parenchyma, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) were measured and histological evaluation was performed at 6 hours after reperfusion.

RESULTS

In the group treated with beta-SQAG9 at a dose of 10 mg/kg, AST, ALT, and LDH were significantly reduced, and the amount of neutrophil infiltration also was significantly reduced.

CONCLUSIONS

Our data suggest that SQAG-9 (10 mg/kg) reduces the warm hepatic I/R injury.

Synthetic sulfonolipids deduced from sulfonoquinovosyl diacylglycerols of sea urchin reduces hepatic ischemia-reperfusion injury in rats

BACKGROUND

In hepatic surgery and liver transplantation, ischemia-reperfusion (I/R) is an unavoidable process, and protection against hepatic I/R injury is a major unresolved problem. In this study, we investigated whether 3-O-(6-deoxy-6-sulfono-beta-D-glucopyranosyl)-1,2-di-O-acylglycerol bound to saturated C18 fatty acids (beta-SQAG9), which was derived from sea urchin intestines, could reduce this injury. This agent was recently reported to have immunosuppressive effects in allogeneic rat skin grafts.

MATERIALS & METHODS

Male Lewis rats were divided into two experimental groups. Group 1 rats were injected with SQAG9 (50 mg/kg) into the penile vein 15 minutes before the induction of ischemia and into the portal vein just reperfusion. The same amounts of normal saline were injected into rats in the control group (group 2). Each experimental groups included six rats. Seventy percent hepatic ischemia (20 minutes) was induced by occluding the blood vessels and bile duct with a vascular clamp. For examination of hepatic function, serum levels of aspartate aminotransferase, (AST) alanine transaminase (ALT), and lactic dehydrogenase (LDH) were measured. In addition, histological examination was also assessed.

RESULTS

Three hours after reperfusion, the mean plasma concentration of AST, ALT, LDH in group 1 was suppressed compared with group 2. Six hours after reperfusion, the hepatic damage in group 1 was mild in comparison with that in group 2.

CONCLUSIONS

Our data demonstrated that SQAG-9 reduced the warm hepatic I/R injury.