[Microvascular Decompression to Treat Abducens Nerve Paralysis Caused by Compression of the Anterior Inferior Cerebellar Artery:A Case Report].

Microvascular decompression(MVD)is an effective treatment for hemifacial spasm and trigeminal neuralgia. However, there are few reports regarding its use with abducens nerve palsy. Here, we report the case of a 77-year-old male who presented with diplopia and was admitted to our facility for right abducens nerve palsy. MRI constructive interference in steady-state(CISS)showed that the right anterior inferior cerebellar artery(AICA)was curved in a posterior-superior direction at the beginning of the region of origin, causing compression of the root exit zone of the right abducens nerve. In addition, MRI showed an unruptured fusiform aneurysm(5.3mm×7.1mm)of the vertebral artery(VA)involving the posterior inferior cerebellar artery(PICA). However it was not related to abducens nerve paralysis. The aneurysm was successfully treated with an occipital artery-posterior inferior cerebellar artery(OA-PICA)bypass and clipping of the proximal VA and PICA origin. The position of the offending artery was moved using a Teflon® felt fibrin glue and the retrosigmoid transcondylar fossa approach. The patient recovered from abducens nerve paralysis with no new neurological deficit. We emphasize the importance of choosing an appropriate approach as this increases the possibility of treating abducens nerve paralysis in a timely manner.

Adsorption of Nafamostat Mesilate on AN69ST Membranes: A Single-Center Retrospective and In Vitro Study.

We examined whether AN69ST (acrylonitrile and methallyl sulfonate copolymer) membranes adsorb nafamostat mesilate. This study retrospectively analyzed 87 continuous hemodiafiltration sessions in vivo. We divided the continuous hemodiafiltration sessions into AN69ST and non-AN69ST groups using the nafamostat mesilate dose and activated clotting time as indicators of nafamostat mesilate adsorption onto the membrane. Furthermore, we studied the in vitro adsorption of nafamostat mesilate from nafamostat mesilate solutions onto four different hemodialysis membranes. This in vivo study shows that nafamostat mesilate doses were significantly higher, but activated clotting times were shorter (P < 0.001) in the AN69ST group than in the non-AN69ST group. These results suggest that AN69ST adsorbs nafamostat mesilate. Further, the in vitro experiments show that nafamostat mesilate adsorbs AN69ST on membranes significantly more than the other membranes tested. These in vitro and clinical findings provide evidence that AN69ST may adsorb nafamostat mesilate.

Usefulness of plasminogen activator inhibitor-1 as a predictive marker of mortality in sepsis.

BACKGROUND: Sepsis is one of the most significant causes of mortality in intensive care units. It indicates crosstalk between inflammation and coagulation. In this study, we aimed to identify prognostic markers among sepsis biomarkers and coagulation/fibrinolysis markers. METHODS: Patients with sepsis according to the Sepsis-3 criteria were enrolled from January 2013 to September 2015. Univariate and multivariate logistic regression analyses were performed to identify an independent predictive marker of 28-day mortality among sepsis biomarkers and coagulation/fibrinolysis markers on ICU admission. Receiver operating characteristic analysis was performed; the optimal cutoff value of 28-day mortality was calculated using the predictive marker. Patients were classified into two groups according to the cutoff level of the predictive marker. Patient characteristics were compared between the groups. RESULTS: A total of 186 patients were enrolled in this study; the 28-day mortality was 19.4% (36/186). PAI-1 was identified as the only independent predictive marker of 28-day mortality by univariate and multivariate logistic regression. The area under the curve was 0.72; the optimal cutoff level was 83 ng/ml (sensitivity, 75%; specificity, 61%). Patients were classified into a higher group (PAI-1 level ≥83 ng/ml; n = 85) and a lower group (PAI-1 level <83 ng/ml; n = 101). All disseminated intravascular coagulation (DIC) scores and Sequential Organ Failure Assessment score were significantly higher in the higher group than in the lower group. CONCLUSIONS: PAI-1 can predict prognosis in sepsis patients. PAI-1 reflects DIC with suppressed fibrinolysis and organ failure, with microthrombi leading to microcirculatory dysfunction.

Potential use of procalcitonin as biomarker for bacterial sepsis in patients with or without acute kidney injury.

INTRODUCTION: There are few investigations regarding the relationships between procalcitonin (PCT) and the acute kidney injury (AKI) in the diagnosis of sepsis. The purpose of this study was to clarify the diagnostic accuracy of the use of PCT levels in patients with or without AKI. METHODS: This study was conducted as a single-center retrospective study. We enrolled 393 patients in whom PCT were measured on admission. We grouped the patients into non-AKI and AKI, and those with AKI were classified according to the RIFLE criteria (Risk, Injury, Failure). The patients in each group were further classified into the sepsis and the non-sepsis group. We subsequently investigated the diagnostic accuracy of the PCT for detecting sepsis in these groups. RESULTS: The levels of PCT were significantly higher in the sepsis group than in the non-sepsis group among the non-AKI and each AKI patients (p < 0.0001). The diagnostic accuracy of the PCT for detecting sepsis was determined according to a ROC analysis; AUC value was 0.958 in the non-AKI group, in the Risk, Injury and Failure groups were 0.888 and 0.917, 0.857, respectively. AUC value for non-AKI group was significantly different from that of Failure group (p < 0.05). CONCLUSIONS: In Failure AKI patients, the diagnostic accuracy of the PCT level is significantly lower than non-AKI patients. It is therefore suggested that we should be careful in using PCT value to diagnose sepsis in patients with Failure under RIFLE criteria.

Stable replication of the EBNA1/OriP-mediated baculovirus vector and its application to anti-HCV gene therapy.

BACKGROUND: Hepatitis C virus (HCV) is one of the main causes of liver-related morbidity and mortality. Although combined interferon-alpha-ribavirin therapy is effective for about 50% of the patients with HCV, better therapies are needed and preventative vaccines have yet to be developed. Short-hairpin RNAs (shRNAs) inhibit gene expression by RNA interference. The application of transient shRNA expression is limited, however, due to the inability of the shRNA to replicate in mammalian cells and its inefficient transduction. The duration of transgene (shRNA) expression in mammalian cells can be significantly extended using baculovirus-based shRNA-expressing vectors that contain the latent viral protein Epstein-Barr nuclear antigen 1 (EBNA1) and the origin of latent viral DNA replication (OriP) sequences. These recombinant vectors contain compatible promoters and are highly effective for infecting primary hepatocyte and hepatoma cell lines, making them very useful tools for studies of hepatitis B and hepatitis C viruses. Here, we report the use of these baculovirus-based vector-derived shRNAs to inhibit core-protein expression in full-length hepatitis C virus (HCV) replicon cells. RESULTS: We constructed a long-term transgene shRNA expression vector that contains the EBV EBNA1 and OriP sequences. We also designed baculovirus vector-mediated shRNAs against the highly conserved core-protein region of HCV. HCV core protein expression was inhibited by the EBNA1/OriP baculovirus vector for at least 14 days, which was considerably longer than the 3 days of inhibition produced by the wild-type baculovirus vector. CONCLUSION: These findings indicate that we successfully constructed a long-term transgene (shRNA) expression vector (Ac-EP-shRNA452) using the EBNA1/OriP system, which was propagated in Escherichia coli and converted into mammalian cells. The potential anti-HCV activity of the long-term transgene (shRNA) expression vector was evaluated with the view of establishing highly effective therapeutic agents that can be further developed for HCV gene therapy applications.

Mechanism and repertoire of ASC-mediated gene expression.

Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is an adaptor molecule that mediates inflammatory and apoptotic signals. Although the role of ASC in caspase-1-mediated IL-1beta and IL-18 maturation is well known, ASC also induces NF-kappaB activation and cytokine gene expression in human cells. In this study, we investigated the molecular mechanism and repertoire of ASC-induced gene expression in human cells. We found that the specific activation of ASC induced AP-1 activity, which was required for optimal IL8 promoter activity. ASC activation also induced STAT3-, but not STAT1-, IFN-stimulated gene factor 3- or NF-AT-dependent reporter gene expression. The ASC-mediated AP-1 activation was NF-kappaB-independent and primarily cell-autonomous response, whereas the STAT3 activation required NF-kappaB activation and was mediated by a factor that can act in a paracrine manner. ASC-mediated AP-1 activation was inhibited by chemical or protein inhibitors for caspase-8, caspase-8-targeting small-interfering RNA, and p38 and JNK inhibitors, but not by a caspase-1 inhibitor, caspase-9 or Fas-associated death domain protein (FADD) dominant-negative mutants, FADD- or RICK-targeting small-interfering RNAs, or a MEK inhibitor, indicating that the ASC-induced AP-1 activation is mediated by caspase-8, p38, and JNK, but does not require caspase-1, caspase-9, FADD, RICK, or ERK. DNA microarray analyses identified 75 genes that were induced by ASC activation. A large proportion of them was related to transcription (23%), inflammation (21%), or cell death (16%), indicating that ASC is a potent inducer of inflammatory and cell death-related genes. This is the first report of ASC-mediated AP-1 activation and the repertoire of genes induced downstream of ASC activation.

Caspase-8- and JNK-dependent AP-1 activation is required for Fas ligand-induced IL-8 production.

Despite a dogma that apoptosis does not induce inflammation, Fas ligand (FasL), a well-known death factor, possesses pro-inflammatory activity. For example, FasL induces nuclear factor kappaB (NF-kappaB) activity and interleukin 8 (IL-8) production by engagement of Fas in human cells. Here, we found that a dominant negative mutant of c-Jun, a component of the activator protein-1 (AP-1) transcription factor, inhibits FasL-induced AP-1 activity and IL-8 production in HEK293 cells. Selective inhibition of AP-1 did not affect NF-kappaB activation and vice versa, indicating that their activations were not sequential events. The FasL-induced AP-1 activation could be inhibited by deleting or introducing the lymphoproliferation (lpr)-type point mutation into the Fas death domain (DD), knocking down the Fas-associated DD protein (FADD), abrogating caspase-8 expression with small interfering RNAs, or using inhibitors for pan-caspase and caspase-8 but not caspase-1 or caspase-3. Furthermore, wildtype, but not a catalytically inactive mutant, of caspase-8 reconstituted the FasL-induced AP-1 activation in caspase-8-deficient cells. Fas ligand induced the phosphorylation of two of the three major mitogen-activated protein kinases (MAPKs): extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) but not p38 MAPK. Unexpectedly, an inhibitor for JNK but not for MAPK/ERK kinase inhibited the FasL-induced AP-1 activation and IL-8 production. These results demonstrate that FasL-induced AP-1 activation is required for optimal IL-8 production, and this process is mediated by FADD, caspase-8, and JNK.

Long-term transgene expression and inhibition of HIV-1 replication by a Cre/loxP-EBNA-1/oriP HIV-1-dependent ribozyme vector: Applications for HIV-1 gene therapy.

The cleavage of target mRNA by ribozymes is being exploited as a means of gene silencing in nucleic-acid-based therapies. We previously established an HIV-1-dependent ribozyme-expression vector system, based on Cre-loxP technology with an LTR-gag-p17 promoter as a molecular switch for use in acute HIV-1 infection. The simultaneous expression of the Cre protein and loxP homologous recombination induced a high level of HIV-1-replication inhibition, but ribozyme expression was transient. In the current study, we overcame this limitation by inserting EBNA-1 and oriP genes from the Epstein-Barr virus (EBV) into the vector. When this plasmid was introduced into HeLa CD4(+) cells, we observed long-term expression of both the EGFP reporter gene and the ribozyme. Moreover, HIV-1 replication was inhibited in the long-term in transfected cells. These data suggest that the HIV-1-dependent ribozyme-expression vector containing EBNA-1/oriP sequences would be a useful tool in HIV-1 gene therapy applications.

ASC-mediated NF-kappaB activation leading to interleukin-8 production requires caspase-8 and is inhibited by CLARP.

ASC is an adaptor molecule that mediates apoptotic and inflammatory signals from several Apaf-1-like molecules, including CARD12/Ipaf, cryopyrin/PYPAF1, PYPAF5, PYPAF7, and NALP1. To characterize the signaling pathway mediated by ASC, we established cell lines in which muramyl dipeptide, the bacterial component recognized by another Apaf-1-like molecule, Nod2, induced an interaction between a CARD12-Nod2 chimeric protein and ASC, and elicited cell autonomous NF-kappaB activation. This response required caspase-8, and was suppressed by CLARP/FLIP, an inhibitor of caspase-8. The catalytic activity of caspase-8 was required for the ASC-mediated NF-kappaB activation when caspase-8 was expressed at an endogenous level, although it was not essential when caspase-8 was overexpressed. In contrast, FADD, the adaptor protein linking Fas and caspase-8, was not required for this response. Consistently, ASC recruited caspase-8 and CLARP but not FADD and Nod2 to its speck-like aggregates in cells. Finally, muramyl dipeptide induced interleukin-8 production in MAIL8 cells. These results are the first to indicate that caspase-8 plays an important role in the ASC-mediated NF-kappaB activation, and that the ASC-mediated NF-kappaB activation actually induces physiologically relevant gene expression.

Suppression of human immunodeficiency virus type 1 (HIV-1) replication by an HIV-1-dependent double locked vector with the Cre/loxP system.

We previously demonstrated the function of an HIV-1-dependent ribozyme expression vector, with which the site-specific excision of loxP sequences can be achieved by using the Cre-loxP system (ON/OFF) as a molecular switch in an acute HIV-1 infection. However, this expression system also revealed the lower, non-specific expression of the anti-H1V-1 ribozyme in the absence of tat. To circumvent this problem, we used the more efficient HIV-1-dependent Cre recombinase gene expression vector, encoding the LTR-gag-p17 (extending from the 5'-LTR to the middle of the gag gene (pLTR-gag-p17-Cre)). Comparatively, the pLTR-gag-p17-Cre induces a higher Cre-protein expression level in an HIV-1 infection-dependent manner than the minimal pLTR-Cre. Furthermore, we constructed the ploxP-Rz-U5 and pLTR-gag-p17-Cre plasmids and also combined them into a single vector, pLTR-gag-p17-Cre/loxP-Rz-U5, for a comparison of their anti-HIV-1 activities. The resultant simultaneous expression of the Cre protein and the homologous recombination of the two loxP sequences induced a high level of HIV-1 replication inhibition (95%). Significantly, a high steady-state of ribozyme expression was observed in the RT-PCR analysis. These data imply that targeting the HIV-1 genes with the pLTR-gag-p17-Cre/loxP-Rz-U5 vector, which mediates HIV-1-dependent ribozyme expression, would be a useful tool for HIV-1 gene therapy applications.

Fas ligand induces cell-autonomous NF-kappaB activation and interleukin-8 production by a mechanism distinct from that of tumor necrosis factor-alpha.

Fas ligand (FasL) has been well characterized as a death factor. However, recent studies revealed that FasL possesses inflammatory activity. Here we found that FasL induces production of the inflammatory chemokine IL-8 without inducing apoptosis in HEK293 cells. Reporter gene assays involving wild-type and mutated IL-8 promoters and NF-kappaB- and AP-1 reporter constructs indicated that an FasL-induced NF-kappaB and AP-1 activity are required for maximal promoter activity. FasL induced NF-kappaB activation with slower kinetics than did TNF-alpha, yet this response was cell autonomous and not mediated by secondary paracrine factors. The death domain of Fas, FADD, and caspase-8 were required for NF-kappaB activation by FasL. A dominant-negative mutant of IKKgamma inhibited the FasL-induced NF-kappaB activation. However, TRADD and RIP, which are essential for the TNF-alpha-induced NF-kappaB activation, were not involved in the FasL-induced NF-kappaB activation. Moreover, CLARP/FLIP inhibited the FasL- but not the TNF-alpha-induced NF-kappaB activation. These results show that FasL induces NF-kappaB activation and IL-8 production by a novel mechanism, distinct from that of TNF-alpha. In addition, we found that mouse FADD had a dominant-negative effect on the FasL-induced NF-kappaB activation in HEK293 cells, which may indicate a species difference between human and mouse in the FasL-induced NF-kappaB activation.

Development of HIV-1 dependent gene expression vector with the Cre/loxP (ON) system.

We used the HIV-1 5'LTR and the Cre/loxP system to develop an anti-gene expression system. The LTR promoter of HIV-1 has a specific activity that includes the intermediary region of gag, as shown in a previous report. We constructed the U5-region of HIV-1 as the target of the ribozyme expression vector (pCre/loxP-Rz), with the Cre/loxP system under the control of this LTR promoter. The function of this vector is to induce the HIV-1 dependent ribozyme-mediated inhibition in a dose-responsive manner. Furthermore, ribozyme mRNA expression was detected in the presence of pNL4-3 in HeLa-CD4+ cells. These studies are expected to yield novel applications of antiviral strategies for HIV-1.

Inhibition of HIV-1 replication by an HIV-1 dependent ribozyme expression vector with the Cre/loxP (ON/OFF) system.

Antiviral strategies to inhibit HIV-1 replication have included the generation of gene products that provide the intracellular inhibition of an essential viral protein or RNA. When used in conjunction with the HIV-1 long terminal repeat (LTR), an inducible promoter dependent on the virus-encoded trans-activator (tat), relatively high background activity is still observed in the absence of tat (Caruso & Klatzmann, 1992; Dinges et al., 1995). In order to circumvent this problem, we used the Cre/loxP (ON/OFF) recombination system as a tool for our investigation. In the present study, we constructed a loxP-cassette vector with the ribozyme (Rz) expression portion under the control of the tRNAi(Met) promoter between two loxP sequences (plox-Rz-U5). We also constructed an HIV-1 LTR promoter-driven Cre recombinase gene (pLTR-Cre). These vectors were triple-transfected into HeLa CD4 cells with the HIV-1 pseudotype viral expression vector. Basal activity was not detectable before HIV-1 infection. The LTR-dependent Cre protein product in HIV-1 infected HeLa CD4 cells expressed the ribozyme by inducing loxP homologous recombination, which strongly inhibited the HIV-1 gene expression. These results demonstrate the potential of an anti-ribozyme with the Cre/loxP system for controlling HIV-1 infection via gene therapy.