bluuebunny/crossref_metadata_2025 huggingface dataset:
Cleavage Specificity of the UL48 Deubiquitinating Protease Activity of Human Cytomegalovirus and the Growth of an Active-Site Mutant Virus in Cultured Cells
Authors: Kim Eui Tae , Oh Se Eun , Lee Yun-Ok , Gibson Wade , Ahn Jin-Hyun
Published: September 2009

The human cytomegalovirus (HCMV) open reading frame UL48 encodes a 253-kDa tegument protein that is closely associated with the capsid and was recently shown to have ubiquitin-specific protease activity (J. Wang, A. N. Loveland, L. M. Kattenhorn, H. L. Ploegh, and W. Gibson, J. Virol. 80:6003-6012, 2006). Here, we examined the cleavage specificity of this deubiquitinase (DUB) and replication characteristics of an active-site mutant virus. The purified catalytic domain of the UL48 DUB (1 to 359 amino acids), corresponding to the herpes simplex virus UL36
USP
DUB (L. M. Kattenhorn, G. A. Korbel, B. M. Kessler, E. Spooner, and H. L. Ploegh, Mol. Cell 19:547-557, 2005), efficiently released ubiquitin but not ubiquitin-like modifications from a hemagglutinin peptide substrate. Mutating the active-site residues Cys24 or His162 (C24S and H162A, respectively) abolished this activity. The HCMV UL48 and HSV UL36
USP
DUBs cleaved both Lys48- and Lys63-linked ubiquitin dimers and oligomers, showing more activity toward Lys63 linkages. The DUB activity of the full-length UL48 protein immunoprecipitated from virus-infected cells also showed a better cleavage of Lys63-linked ubiquitinated substrates. An HCMV (Towne) mutant virus in which the UL48 DUB activity was destroyed [UL48(C24S)] produced 10-fold less progeny virus and reduced amounts of viral proteins compared to wild-type virus at a low multiplicity of infection. The mutant virus also produced perceptibly less overall deubiquitination than the wild-type virus. Our findings demonstrate that the HCMV UL48 DUB contains both a ubiquitin-specific carboxy-terminal hydrolase activity and an isopeptidase activity that favors ubiquitin Lys63 linkages and that these activities can influence virus replication in cultured cells.
Mutations in the Thumb Allow Human Immunodeficiency Virus Type 1 Reverse Transcriptase To Be Cleaved by Protease in Virions
Authors: Dunn Linda L. , McWilliams Mary Jane , Das Kalyan , Arnold Eddy , Hughes Stephen H.
Published: September 2009

Although human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has been extensively studied, there are still significant questions about the effects of mutations on the maturation and stability of RT. We show here that a significant fraction (>80%) of the single point mutations we generated in the thumb subdomain of HIV-1 (RT) affect the stability of RT in virions. Fragments of the unstable mutant RTs can be detected in Western blots of virion proteins; however, the degree of degradation varies. The titers of the mutants whose virions contain degraded RTs are reduced. Some, but not all, of the unstable RT thumb subdomain mutants we analyzed have a temperature-sensitive phenotype. A preliminary survey of mutations in other subdomains of RT shows that some of these mutations also destabilize RT. The stability of the RT mutants is enhanced by the addition of a protease inhibitor, suggesting that the viral protease plays an important role in the degradation of the mutant RTs. These results confirm and extend earlier reports of mutations that affect the stability of RT in virions. The data suggest that the stability of a mutant RT in virions could be a major factor in determining the virus titer and, by extension, viral fitness, which could affect whether a mutation in RT is acceptable to the virus.
Cell Cycle Arrest by Transforming Growth Factor β1 Enhances Replication of Respiratory Syncytial Virus in Lung Epithelial Cells
Authors: Gibbs John D. , Ornoff Douglas M. , Igo Heather A. , Zeng Jennifer Y. , Imani Farhad
Published: September 2009

Respiratory syncytial virus (RSV) is a common respiratory viral infection in children which is associated with immune dysregulation and subsequent induction and exacerbations of asthma. We recently reported that treatment of primary human epithelial cells (PHBE cells) with transforming growth factor β (TGF-β) enhanced RSV replication. Here, we report that the enhancement of RSV replication is mediated by induction of cell cycle arrest. These data were confirmed by using pharmacologic inhibitors of cell cycle progression, which significantly enhanced RSV replication. Our data also showed that RSV infection alone resulted in cell cycle arrest in A549 and PHBE cells. Interestingly, our data showed that RSV infection induced the expression of TGF-β in epithelial cells. Blocking of TGF-β with anti-TGF-β antibody or use of a specific TGF-β receptor signaling inhibitor resulted in rescue of the RSV-induced cell cycle arrest, suggesting an autocrine mechanism. Collectively, our data demonstrate that RSV regulates the cell cycle through TGF-β in order to enhance its replication. These findings identify a novel pathway for upregulation of virus replication and suggest a plausible mechanism for association of RSV with immune dysregulation and asthma.
Control of Herpes Simplex Virus Replication Is Mediated through an Interferon Regulatory Factor 3-Dependent Pathway
Authors: Menachery Vineet D. , Leib David A.
Published: September 2009

The type I interferon (IFN) cascade is critical in controlling viral replication and pathogenesis. Recognition pathways triggered by viral infection rapidly induce the type I IFN cascade, often in an IFN regulatory factor 3 (IRF-3)-dependent fashion. This dependence predicts that loss of IRF-3 would render early recognition pathways inoperative and thereby impact virus replication, but this has not been observed previously with herpes simplex virus type 1 (HSV-1) in vitro. In this study, HSV-1-infected IRF-3
−/−
bone marrow-derived dendritic cells (BMDCs) and macrophages supported increased HSV replication compared to control cells. In addition, IRF-3-deficient BMDCs exhibited delayed type I IFN synthesis compared to control cells. However, while IFN pretreatment of IRF-3
−/−
BMDCs resulted in reduced virus titers, a far greater reduction was seen after IFN treatment of wild-type cells. This suggests that even in the presence of exogenously supplied IFN, IRF-3
−/−
BMDCs are inherently defective in the control of HSV-1 replication. Together, these results demonstrate a critical role for IRF-3-mediated pathways in controlling HSV-1 replication in cells of the murine immune system.
Adeno-Associated Virus Site-Specific Integration Is Mediated by Proteins of the Nonhomologous End-Joining Pathway
Authors: Daya Shyam , Cortez Nenita , Berns Kenneth I.
Published: September 2009

Adeno-associated virus type 2 (AAV 2) is the only eukaryotic virus capable of site-specific integration; the target site is at chromosome 19q13.4, a site termed AAVS1. The biology of AAV latency has been extensively studied in cell culture, yet the precise mechanism and the required cellular factors are not known. In this study, we assessed the relative frequencies of stable site-specific integration by characterization of cell clones containing integrated AAV vectors. By this assay, two proteins involved in nonhomologous end joining (NHEJ), DNAPKcs and ligase IV, exhibit differential effects on AAV site-specific integration. DNAPKcs is not required; its presence increases the frequency of junction formation indicative of site-specific integration, but seems to reduce the ratio of site-specific integration to random integration (i.e., the latter is even more enhanced). In contrast, site-specific integration is significantly reduced relative to random integration in cells deficient in ligase IV expression. Furthermore, we show that single-stranded AAV vectors are better substrates for site-specific integration than are self-complementary AAV vectors; the absence of DNAPKcs did not affect the targeted integration of these double-stranded AAV vectors. Together, these data suggest that NHEJ proteins participate in site-specific integration, and indicate a role for the single-stranded form of AAV DNA in targeted integration.
Autographa californica
Multiple Nucleopolyhedrovirus Core Gene
ac96
Encodes a Per Os Infectivity Factor (
pif-4
)
Authors: Fang Minggang , Nie Yingchao , Harris Stephanie , Erlandson Martin A. , Theilmann David A.
Published: September 2009

Autographa californica
multiple nucleopolyhedrovirus (AcMNPV)
ac96
is a core gene, but its role in virus replication is still unknown. To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an
ac96
-null virus (vAc

96

null
). Our analyses showed that the absence of
ac96
does not affect budded virus (BV) production or viral DNA replication in infected Sf9 cells. Western blotting and confocal immunofluorescence analysis showed that AC96 is expressed in both the cytoplasm and the nucleus throughout infection. In addition, AC96 was detected in the envelope fractions of both BV and occlusion-derived virus. Injection of vAc

96

null
BV into the hemocoel killed
Trichoplusia ni
larvae as efficiently as repaired and control viruses; however, vAc

96

null
was unable to infect the midgut tissue of
Trichoplusia ni
larvae when inoculated per os. Therefore, the results of this study show that
ac96
encodes a new per os infectivity factor (PIF-4).
Loss of Raltegravir Susceptibility by Human Immunodeficiency Virus Type 1 Is Conferred via Multiple Nonoverlapping Genetic Pathways
Authors: Fransen Signe , Gupta Soumi , Danovich Robert , Hazuda Daria , Miller Michael , Witmer Marc , Petropoulos Christos J. , Huang Wei
Published: September 2009

The human immunodeficiency virus type 1 (HIV-1) integrase mutations N155H and Q148R(H)(K) that reduce susceptibility to the integrase inhibitor raltegravir have been identified in patients failing treatment regimens containing raltegravir. Whether these resistance mutations occur individually or in combination within a single virus genome has not been defined, nor do we fully understand the impact of these primary mutations and other secondary mutations on raltegravir susceptibility and viral replication capacity. To address these important questions, we investigated the raltegravir susceptibility and replication capacity of viruses containing mutations at positions 155 and 148 separately or in combination with secondary mutations selected in subjects failing treatment regimens containing raltegravir. Clonal analysis demonstrated that N155H and Q148R(H)(K) occur independently, not in combination. Viruses containing a Q148R(H)(K) mutation generally displayed larger reductions in raltegravir susceptibility than viruses with an N155H mutation. Analysis of site-directed mutants indicated that E92Q in combination with N155H resulted in a higher level of resistance to raltegravir than N155H alone. Viruses containing a Q148R(H) mutation together with a G140S mutation were more resistant to raltegravir than viruses containing a Q148R(H) mutation alone; however, viruses containing G140S and Q148K were more susceptible to raltegravir than viruses containing a Q148K mutation alone. Both N155H and Q148R(H)(K) mutations reduced the replication capacity, while the addition of secondary mutations either improved or reduced the replication capacity depending on the primary mutation. This study demonstrates distinct genetic pathways to resistance in subjects failing raltegravir regimens and defines the effects of primary and secondary resistance mutations on raltegravir susceptibility and replication capacity.
Clade-Specific Evolution Mediated by HLA-B*57/5801 in Human Immunodeficiency Virus Type 1 Clade A1 p24
Authors: McKinnon Lyle R. , Capina Rupert , Peters Harold , Mendoza Mark , Kimani Joshua , Wachihi Charles , Kariri Anthony , Kimani Makobu , Richmond Meika , Kiazyk Sandy Koesters , Fowke Keith R. , Jaoko Walter , Luo Ma , Ball T. Blake , Plummer Francis A.
Published: September 2009

HLA-B*57-mediated selection pressure leads to a typical escape pathway in human immunodeficiency virus type 1 (HIV-1) CD8 epitopes such as TW10. Whether this T242N pathway is shared by all clades remains unknown. We therefore assessed the nature of HLA-B*57 selection in a large, observational Kenyan cohort where clades A1 and D predominate. While T242N was ubiquitous in clade D HLA-B*57
+
subjects, this mutation was rare (15%) in clade A1. Instead, P243T and I247L were selected by clade A1-infected HLA-B*57 subjects but not by HLA-B*5801
+
subjects. Our data suggest that clade A1 consensus proline at Gag residue 243 might represent an inherent block to T242N escape in clade A1. We confirmed immunologically that P243T and I247L likely represent escape mutations. HLA-B*57 evolution also differed between clades in the KF11 and IW9 epitopes. A better understanding of clade-specific evolution is important for the development of HIV vaccines in regions with multiple clades.
Elevated Levels of Innate Immune Modulators in Lymph Nodes and Blood Are Associated with More-Rapid Disease Progression in Simian Immunodeficiency Virus-Infected Monkeys
Authors: Durudas Andre , Milush Jeffrey M. , Chen Hui-Ling , Engram Jessica C. , Silvestri Guido , Sodora Donald L.
Published: September 2009

Cytokines and chemokines are critical for establishing tissue-specific immune responses and play key roles in modulating disease progression in simian immunodeficiency virus (SIV)-infected macaques and human immunodeficiency virus (HIV)-infected humans. The goal here was to characterize the innate immune response at different tissue sites and to correlate these responses to clinical outcome, initially focusing on rhesus macaques orally inoculated with SIV and monitored until onset of simian AIDS. Cytokine and chemokine mRNA transcripts were assessed at lymph nodes (LN) and peripheral blood cells utilizing quantitative real-time PCR at different time points postinfection. The mRNA expression of four immune modulators—alpha interferon (IFN-α), oligoadenylate synthetase (OAS), CXCL9, and CXCL10—was positively associated with disease progression within LN tissue. Elevated cytokine/chemokine expression in LN did not result in any observed beneficial outcome since the numbers of CXCR3
+
cells were not increased, nor were the SIV RNA levels decreased. In peripheral blood, increased OAS and CXCL10 expression were elevated in SIV
+
monkeys that progress the fastest to simian AIDS. Our results indicate that higher IFN-α, OAS, CXCL9, and CXCL10 mRNA expression in LN was associated with rapid disease progression and a LN environment that may favor SIV replication. Furthermore, higher expression of CXCL10 and OAS in peripheral blood could potentially serve as a diagnostic marker for hosts that are likely to progress to AIDS. Understanding the expression patterns of key innate immune modulators will be useful in assessing the disease state and potential rates of disease progression in HIV
+
patients, which could lead to novel therapy and vaccine approaches.
Fusion between Perinuclear Virions and the Outer Nuclear Membrane Requires the Fusogenic Activity of Herpes Simplex Virus gB
Authors: Wright Catherine C. , Wisner Todd W. , Hannah Brian P. , Eisenberg Roselyn J. , Cohen Gary H. , Johnson David C.
Published: September 2009

Herpesviruses cross nuclear membranes (NMs) in two steps, as follows: (i) capsids assemble and bud through the inner NM into the perinuclear space, producing enveloped virus particles, and (ii) the envelopes of these virus particles fuse with the outer NM. Two herpes simplex virus (HSV) glycoproteins, gB and gH (the latter, likely complexed as a heterodimer with gL), are necessary for the second step of this process. Mutants lacking both gB and gH accumulate in the perinuclear space or in herniations (membrane vesicles derived from the inner NM). Both gB and gH/gL are also known to act directly in fusing the virion envelope with host cell membranes during HSV entry into cells, i.e., both glycoproteins appear to function directly in different aspects of the membrane fusion process. We hypothesized that HSV gB and gH/gL also act directly in the membrane fusion that occurs during virus egress from the nucleus. Previous studies of the role of gB and gH/gL in nuclear egress involved HSV gB and gH null mutants that could potentially also possess gross defects in the virion envelope. Here, we produced recombinant HSV-expressing mutant forms of gB with single amino acid substitutions in the hydrophobic “fusion loops.” These fusion loops are thought to play a direct role in membrane fusion by insertion into cellular membranes. HSV recombinants expressing gB with any one of four fusion loop mutations (W174R, W174Y, Y179K, and A261D) were unable to enter cells. Moreover, two of the mutants, W174Y and Y179K, displayed reduced abilities to mediate HSV cell-to-cell spread, and W174R and A261D exhibited no spread. All mutant viruses exhibited defects in nuclear egress, enveloped virions accumulated in herniations and in the perinuclear space, and fewer enveloped virions were detected on cell surfaces. These results support the hypothesis that gB functions directly to mediate the fusion between perinuclear virus particles and the outer NM.
Mixed Infections ofPepino Mosaic VirusStrains Modulate the Evolutionary Dynamics of this Emergent Virus
Authors: Gómez P. , Sempere R. N. , Elena S. F. , Aranda M. A.
Published: September 2009

Pepino mosaic virus(PepMV) is an emerging pathogen that causes severe economic losses in tomato crops (Solanum lycopersicumL.) in the Northern hemisphere, despite persistent attempts of control. In fact, it is considered one of the most significant viral diseases for tomato production worldwide, and it may constitute a good model for the analysis of virus emergence in crops. We have combined a population genetics approach with an analysis of in planta properties of virus strains to explain an observed epidemiological pattern. Hybridization analysis showed that PepMV populations are composed of isolates of two types (PepMV-CH2 and PepMV-EU) that cocirculate. The CH2 type isolates are predominant; however, EU isolates have not been displaced but persist mainly in mixed infections. Two molecularly cloned isolates belonging to each type have been used to examine the dynamics of in planta single infections and coinfection, revealing that the CH2 type has a higher fitness than the EU type. Coinfections expand the range of susceptible hosts, and coinfected plants remain symptomless several weeks after infection, so a potentially important problem for disease prevention and management. These results provide an explanation of the observed epidemiological pattern in terms of genetic and ecological interactions among the different viral strains. Thus, mixed infections appear to be contributing to shaping the genetic structure and dynamics of PepMV populations.
Origin and Phylodynamics of Rabbit Hemorrhagic Disease Virus
Authors: Kerr Peter J. , Kitchen Andrew , Holmes Edward C.
Published: September 2009

To determine the origin, phylogenetic relationships, and evolutionary dynamics of rabbit hemorrhagic disease virus (RHDV), we examined 210 partial and complete capsid gene nucleotide sequences. Using a Bayesian Markov chain Monte Carlo approach, we estimated that these sequences evolved at a rate of 3.9 × 10
−4
to 11.9 × 10
−4
nucleotide substitutions per site per year. This rate was consistent across subsets of data, was robust in response to recombination, and casts doubt on the provenance of viral strains isolated from the 1950s to the 1970s, which share strong sequence similarity to modern isolates. Using the same analysis, we inferred that the time to the most recent common ancestor for a joint group of RHDV and rabbit calicivirus sequences was <550 years ago and was <150 years ago for the RHDV isolates that have spread around the world since 1984. Importantly, multiple lineages of RHDV were clearly circulating before the major Chinese outbreak of 1984, a finding indicative of an early evolution of RHDV virulence. Four phylogenetic groups within RHDV were defined and analyzed separately. Each group shared a common ancestor in the mid-1960s or earlier, and each showed an expansion of populations starting before 1984. Notably, the group characterized by the antigenic variant RHDVa harbors the greatest genetic diversity, compatible with an elevated fitness. Overall, we contend that the high virulence of RHDV likely evolved once in the early part of the 20th century, well before the documented emergence of rabbit hemorrhagic disease in 1984.
The Pre-S1 and Antigenic Loop Infectivity Determinants of the Hepatitis B Virus Envelope Proteins Are Functionally Independent
Authors: Le Duff Yann , Blanchet Matthieu , Sureau Camille
Published: September 2009

The hepatitis B virus (HBV) envelope proteins bear two determinants of viral entry: a receptor-binding site (RBS) in the pre-S1 domain of the large envelope protein and a conformation-dependent determinant, of unknown function, in the antigenic loop (AGL) of the small, middle, and large envelope proteins. Using an in vitro infection assay consisting of susceptible HepaRG cells and the hepatitis delta virus (HDV) as a surrogate of HBV, we first investigated whether subelements of the pre-S1 determinant (amino acids 2 to 75), i.e., the N-terminal myristoyl anchor, subdomain 2-48 (RBS), and subdomain 49-75, were functionally separable. In transcomplementation experiments, coexpression of two distinct infectivity-deficient pre-S1 mutants at the surface of HDV virions failed to restore infectivity, indicating that the myristoyl anchor, the 2-48 RBS, and the 49-75 sequence, likely cooperate in
cis
at viral entry. Furthermore, we showed that as much as 52% of total pre-S1 in the HDV envelope could bear infectivity-deficient lesions without affecting entry, indicating that a small number of pre-S1 polypeptides—estimated at three to four per virion—is sufficient for infectivity. We next investigated the AGL activity in the small or large envelope protein background (S- and L-AGL, respectively) and found that lesions in S-AGL were more deleterious to infectivity than in L-AGL, a difference that reflects the relative stoichiometry of the small and large envelope proteins in the viral envelope. Finally, we showed that C147S, an AGL infectivity-deficient substitution, exerted a dominant-negative effect on infectivity, likely reflecting an involvement of C147 in intermolecular disulfide bonds.
Association of the pr Peptides with Dengue Virus at Acidic pH Blocks Membrane Fusion
Authors: Yu I.-M. , Holdaway H. A. , Chipman P. R. , Kuhn R. J. , Rossmann M. G. , Chen J.
Published: September 2009

Flavivirus assembles into an inert particle that requires proteolytic activation by furin to enable transmission to other hosts. We previously showed that immature virus undergoes a conformational change at low pH that renders it accessible to furin (I. M. Yu, W. Zhang, H. A. Holdaway, L. Li, V. A. Kostyuchenko, P. R. Chipman, R. J. Kuhn, M. G. Rossmann, and J. Chen, Science 319:1834-1837, 2008). Here we show, using cryoelectron microscopy, that the structure of immature dengue virus at pH 6.0 is essentially the same before and after the cleavage of prM. The structure shows that after cleavage, the proteolytic product pr remains associated with the virion at acidic pH, and that furin cleavage by itself does not induce any major conformational changes. We also show by liposome cofloatation experiments that pr retention prevents membrane insertion, suggesting that pr is present on the virion in the
trans
-Golgi network to protect the progeny virus from fusion within the host cell.
Interaction of ICP34.5 with Beclin 1 Modulates Herpes Simplex Virus Type 1 Pathogenesis through Control of CD4+T-Cell Responses
Authors: Leib David A. , Alexander Diane E. , Cox Douglas , Yin Jiyi , Ferguson Thomas A.
Published: September 2009

Autophagy is an important component of host innate and adaptive immunity to viruses. It is critical for the degradation of intracellular pathogens and for promoting antigen presentation. Herpes simplex virus type 1 (HSV-1) infection induces an autophagy response, but this response is antagonized by the HSV-1 neurovirulence gene product, ICP34.5. This is due, in part, to its interaction with the essential autophagy protein Beclin 1 (Atg6) via the Beclin-binding domain (BBD) of ICP34.5. Using a recombinant virus lacking the BBD, we examined pathogenesis and immune responses using mouse models of infection. The BBD-deficient virus (Δ68H) replicated equivalently to its marker-rescued counterpart (Δ68HR) at early times but was cleared more rapidly than Δ68HR from all tissues at late times following corneal infection. In addition, the infection of the cornea with Δ68H induced less ocular disease than Δ68HR. These results suggested that Δ68H was attenuated due to its failure to control adaptive rather than innate immunity. In support of this idea, Δ68H stimulated a significantly stronger CD4+T-cell-mediated delayed-type hypersensitivity response and resulted in significantly more production of gamma interferon and interleukin-2 from HSV-specific CD4+T cells than Δ68HR. Taken together, these data suggest a role for the BBD of ICP34.5 in precluding autophagy-mediated class II antigen presentation, thereby enhancing the virulence and pathogenesis of HSV-1.
Chloroquine Administration Does Not Prevent Nipah Virus Infection and Disease in Ferrets
Authors: Pallister Jackie , Middleton Deborah , Crameri Gary , Yamada Manabu , Klein Reuben , Hancock Tim J. , Foord Adam , Shiell Brian , Michalski Wojtek , Broder Christopher C. , Wang Lin-Fa
Published: September 2009

Hendra virus and Nipah virus, two zoonotic paramyxoviruses in the genus
Henipavirus
, have recently emerged and continue to cause sporadic disease outbreaks in humans and animals. Mortality rates of up to 75% have been reported in humans, but there are presently no clinically licensed therapeutics for treating henipavirus-induced disease. A recent report indicated that chloroquine, used in malaria therapy for over 70 years, prevented infection with Nipah virus in vitro. Chloroquine was assessed using a ferret model of lethal Nipah virus infection and found to be ineffective against Nipah virus infection in vivo.
Catheter exchange technique for the Wingspan stent: technical note
Authors: Lesley W S , Rangaswamy R
Published: September 2009

Background and purpose

The only Food and Drug Administration-approved implant for managing intracranial stenosis is the Wingspan stent. Modification of the standard Wingspan stent delivery procedure has not been previously reported.

Material and methods

Retrospective, single-patient, technical report.

Results

Following uneventful balloon angioplasty, a symptomatic intracranial vertebral artery stenosis was inaccessible to Wingspan stent delivery using standard procedural protocol because of poor proximal guide catheter purchase. After placing a Renegade Hi-Flo microcatheter across the stenosis, the Wingspan stent was transferred to this catheter and advanced to the lesion using a Neuroform stabilizer. Unsheathing of the stent yielded uncomplicated, precise placement of the stent with a good clinical result.

Conclusion

The Wingspan stent transfer technique can be used successfully in the management of intracranial stenotic disease.
從 〔社會排斥〕 到 〔社會融合〕 談中國社會福利政策的取向：
Authors: 蘇 細清
Published: September 2009

本文通過對歐洲社會福利政策研究中社會排斥和社會融合取向的作用進行簡要的歷史回顧，並反思社會排斥為主的福利政策研究取向對中國福利政策研究的影響。通過對有關農民工社會福利制度現狀的研究文獻綜述，筆者發現，大多數的研究實際上都是取自社會排斥角度，在探討社會排斥研究模式可能在中國社會福利研究體系中可能存在的困難和不足，筆者提出重新整合社會排斥和社會融合的必要性。第一，整合社會融合的研究模式與中國政府提出的社會和諧目的相一致；第二，整合社會融合的研究模式凸顯社會資本在幫助農民工融入城市的重要作用，有利於減少社會因福利支出而增加的經濟負擔，容易為政府所接受；第三，整合社會融合的研究模式可以進一步促進福利主體間的合作，包括與政府的合作，市民社會之間的協作和融合等；第四，整合社會融合的研究模式有助於政策研究者有技巧和彈性地與政府溝通，有助於政策的落實與實現；最後，整合社會融合的研究模式有助於發展農民工在城市中的代言人，如社會工作者隊伍和 NGO 機構等。

This article begins with historical review on the roles of social exclusion and social inclusion in social welfare policy research in European area. And then critical reflect on the difficulties of social-exclusion-focused research model which domains the Chinese social welfare policy area. Basing on the literature review, through discussing on the current difficulties and insufficiencies of peasant workers' social welfare in China, the integrated model which should view social inclusion and social exclusion as one whole to be social welfare policy research model was proposed to meet the ultimate goal of social welfare policy. The importance of the integrated model was also discussed in the article as: First, integrating social inclusion perspective is consistent with the social harmony tenet which is highlighted by government; Second, integrating social inclusion perspective pays more attention on the functions of social capitals which may play an important role in facilitating peasant workers to adapt to urban cities, at the same time, social capitals may reduce the social welfare economic burden which can be easily accepted by government and facilitate the collaboration with government. Third, integrating social inclusion into social welfare policy research may facilitate the collaboration with government and reduce the tension between urban and rural. Forth, under the integrated model, social welfare policy researches may communicate with government flexibly and get more government support to make the policy realized; and finally, the agencies who can stand for the voices of peasant workers, such as social work team, NGO institutions can be developed rapidly.
Book Review: "正義的中斷 — 對⌈後社會主義⌋狀況的批判性反思 Justice Interruptus — Critical Reflections on the 'Postsocialist' Condition", 南茜•弗雷澤(Nancy Fraser)著, 于海青譯
Authors: 蘇 耀昌
Published: September 2009

未提供摘要。
Selective and specific regulation of ectodomain shedding of angiotensin-converting enzyme 2 by tumor necrosis factor α-converting enzyme
Authors: Iwata Michikado , Silva Enciso Jorge E. , Greenberg Barry H.
Published: September 2009

Angiotensin-converting enzyme 2 (ACE2) is a newly identified regulator of the renin-angiotensin system. This type I membrane-anchored protein has a catalytically active ectodomain that undergoes shedding. Tumor necrosis factor α-converting enzyme (TACE) has been shown to be involved in ACE2 shedding. Although pathophysiological significance of ACE2 shedding has been suggested, regulation of this process by TACE is not clearly defined. We characterized TACE-mediated constitutive ectodomain shedding of ACE2 using wild-type Chinese Hamster Ovary (WT-CHO), the TACE-mutant M2 (M2-CHO) cells, and EC-4 and EC-2 cells that are fibroblasts from wild-type and TACE-null mice, respectively. ACE2 was constitutively cleaved to release two distinct major soluble forms. The deglycosylated molecular masses of the larger (LSF) and smaller soluble form (SSF) were ∼80 and 70 kDa, respectively. These forms had equivalent enzyme activities. Reduced shedding for the LSF from M2-CHO and EC-2 cells when compared with WT-CHO and EC-4 cells, respectively, was noted. TACE reconstitution in EC-2 cells expressing ACE2 resulted in increase in LSF but not SSF release, demonstrating a main role of TACE in LSF release and distinct regulations of release of the two soluble forms. Deletions of the juxtamembrane region of ACE2 reduced LSF release in CHO cell lines, whereas it abolished TACE-induced shedding in EC-2 cells. Analysis of TACE structural domains confirmed that the active site in the catalytic domain is essential for ACE2 shedding but that noncatalytic domains also play additional roles. These results demonstrate selective and specific regulation of constitutive shedding of ACE2 by TACE.
Myostatin inhibits IGF-I-induced myotube hypertrophy through Akt
Authors: Morissette Michael R. , Cook Stuart A. , Buranasombati Cattleya , Rosenberg Michael A. , Rosenzweig Anthony
Published: September 2009

Myostatin is a highly conserved negative regulator of skeletal muscle growth. Loss of functional myostatin in cattle, mice, sheep, dogs, and humans results in increased muscle mass. The molecular mechanisms responsible for this increase in muscle growth are not fully understood. Previously, we have reported that phenylephrine-induced cardiac muscle growth and Akt activation are enhanced in myostatin knockout mice compared with controls. Here we report that skeletal muscle from myostatin knockout mice show increased Akt protein expression and overall activity at baseline secondary to an increase in Akt mRNA. We examined the functional role of myostatin modulation of Akt in C2C12 myotubes, a well-established in vitro model of skeletal muscle hypertrophy. Adenoviral overexpression of myostatin attenuated the insulin-like growth factor-I (IGF-I)-mediated increase in myotube diameter, as well as IGF-I-stimulated Akt phosphorylation. Inhibition of myostatin by overexpression of the NH2-terminal portion of myostatin was sufficient to increase myotube diameter and Akt phosphorylation. Coexpression of myostatin and constitutively active Akt (myr-Akt) restored the increase in myotube diameter. Conversely, expression of dominant negative Akt (dn-Akt) with the inhibitory myostatin propeptide blocked the increase in myotube diameter. Of note, ribosomal protein S6 phosphorylation and atrogin-1/muscle atrophy F box mRNA were increased in skeletal muscle from myostain knockout mice. Together, these data suggest myostatin regulates muscle growth at least in part through regulation of Akt.
Is nephrogenesis affected by preterm birth? Studies in a non-human primate model
Authors: Gubhaju Lina , Sutherland Megan R. , Yoder Bradley A. , Zulli Anthony , Bertram John F. , Black M. Jane
Published: September 2009

Nephrogenesis occurs predominantly in late gestation at a time when preterm infants are already delivered. The aims of this study were to assess the effect of preterm birth and the effect of antenatal glucocorticoid treatment on nephrogenesis. Preterm baboons, which were delivered at 125 days gestation and ventilated for up to 21 days postnatally, were compared with gestational controls. A cohort of preterm baboons that had been exposed to antenatal glucocorticoids were compared with unexposed preterm baboons. The number of glomerular generations was estimated using a medullary ray glomerular-counting method, and glomerular number was estimated using unbiased stereology. CD31 and WT-1 localization was examined using immunohistochemistry and VEGF was localized using in situ hybridization. The number of glomerular generations was not affected by preterm birth, and total glomerular numbers were within the normal range. Kidneys were significantly enlarged in preterm baboons with a significant decrease in glomerular density (number of glomeruli per gram of kidney) in the preterm kidney compared with gestational controls. Neonates exposed to antenatal steroids had an increased kidney-to-body weight ratio and also more developed glomeruli compared with unexposed controls. Abnormal glomeruli, with a cystic Bowman's space and shrunken glomerular tuft, were often present in the superficial renal cortex of both the steroid-exposed and unexposed preterm kidneys; steroid exposure had no significant effect on the proportion of abnormal glomeruli. The proportion of abnormal glomeruli in the preterm kidneys ranged from 0.2 to 18%. In conclusion, although nephrogenesis is ongoing in the extrauterine environment, our findings demonstrate that preterm birth, independent of steroid exposure, is associated with a high proportion of abnormal glomeruli in some, but not all neonatal kidneys. Whether final nephron endowment is affected in those kidneys exhibiting a high proportion of abnormal glomeruli is yet to be confirmed.
Renal salt wasting and chronic dehydration in claudin-7-deficient mice
Authors: Tatum Rodney , Zhang Yuguo , Salleng Kenneth , Lu Zhe , Lin Jen-Jar , Lu Qun , Jeansonne Beverly G. , Ding Lei , Chen Yan-Hua
Published: September 2009

Claudin-7, a member of the claudin family, is highly expressed in distal nephrons of kidneys and has been reported to be involved in the regulation of paracellular Cl−permeability in cell cultures. To investigate the role of claudin-7 in vivo, we generated claudin-7 knockout mice (Cln7−/−) by the gene-targeting deletion method. Here we report that Cln7−/−mice were born viable, but died within 12 days after birth. Cln7−/−mice showed severe salt wasting, chronic dehydration, and growth retardation. We found that urine Na+, Cl−, and K+were significantly increased in Cln7−/−mice compared with that of Cln7+/+mice. Blood urea nitrogen and hematocrit were also significantly higher in Cln7−/−mice. The wrinkled skin was evident when Cln7−/−mice were ∼1 wk old, indicating that they suffered from chronic fluid loss. Transepidermal water loss measurements showed no difference between Cln7+/+and Cln7−/−skin, suggesting that there was no transepidermal water barrier defect in Cln7−/−mice. Claudin-7 deletion resulted in the dramatic increase of aldosterone synthase mRNA level as early as 2 days after birth. The significant increases of epithelial Na+channel α, Na+-Cl−cotransporter, and aquaporin 2 mRNA levels revealed a compensatory response to the loss of electrolytes and fluid in Cln7−/−mice. Na+-K+-ATPase α1expression level was also greatly increased in distal convoluted tubules and collecting ducts where claudin-7 is normally expressed. Our study demonstrates that claudin-7 is essential for NaCl homeostasis in distal nephrons, and the paracellular ion transport pathway plays indispensable roles in keeping ionic balance in kidneys.
Radial Biases in the Processing of Motion and Motion-Defined Contours by Human Visual Cortex
Authors: Clifford Colin W. G. , Mannion Damien J. , McDonald J. Scott
Published: September 2009

Luminance gratings reportedly produce a stronger functional magnetic resonance imaging (fMRI) blood oxygen level–dependent (BOLD) signal in those parts of the retinotopic cortical maps where they are oriented radially to the point of fixation. We sought to extend this finding by examining anisotropies in the response of cortical areas V1–V3 to motion-defined contour stimuli. fMRI at 3 Tesla was used to measure the BOLD signal in the visual cortex of six human subjects. Stimuli were composed of strips of spatial white noise texture presented in an annular window. The texture in alternate strips moved in opposite directions (left–right or up–down). The strips themselves were static and tilted 45° left or right from vertical. Comparison with maps of the visual field obtained from phase-encoded retinotopic analysis revealed systematic patterns of radial bias. For motion, a stronger response to horizontal was evident within V1 and along the borders between V2 and V3. For orientation, the response to leftward tilted contours was greater in left dorsal and right ventral V1–V3. Radial bias for the orientation of motion-defined contours analogous to that reported previously for luminance gratings could reflect cue-invariant processing or the operation of distinct mechanisms subject to similar anisotropies in orientation tuning. Radial bias for motion might be related to the phenomenon of “motion streaks,” whereby temporal integration by the visual system introduces oriented blur along the axis of motion. We speculate that the observed forms of radial bias reflect a common underlying anisotropy in the representation of spatiotemporal image structure across the visual field.
Generalization of Visuomotor Learning Between Bilateral and Unilateral Conditions
Authors: Wang Jinsung , Sainburg Robert L.
Published: September 2009

A long history of behavioral and physiological research has suggested that bilateral coordination invokes unique neural processes that are not involved in unilateral movements. This hypothesis predicts that motor learning should show limited transfer between unilateral and bilateral conditions, which is consistent with a recent finding that indicated partial, but not complete, transfer of learning between the two conditions. However, during learning of new motor skills, transformations must also be made between visual and proprioceptive coordinate systems, a process that may occur upstream to the processes that differentiate bilateral from unilateral movements. We now investigate whether visuomotor adaptations are shared between unilateral and bilateral movement conditions. Our results indicate substantial transfer from bilateral to subsequent unilateral conditions for both arms. Interestingly, whereas the nondominant arm never showed complete adaptation to visual rotation under bilateral conditions, this interference, or lack of improvement, in bilateral performance did not disturb the visuomotor adaptation process or transfer, as reflected by superb unilateral performances immediately following the bilateral conditions. These findings unambiguously indicate that visuomotor adaptation can extensively generalize between bilateral and unilateral conditions, thus suggesting a substantial overlap in the neural processes underlying visuomotor transformations between the two movement conditions. Our findings provide support for a two-stage model of motor planning, in which the visuomotor transformation process precedes the processes that convert the visuomotor plan into effector-specific commands that incorporate bilateral synergies and that result in the forces that determine motion.
Distinct Electrophysiological Properties in Subtypes of Nonspiking Olfactory Local Interneurons Correlate With Their Cell Type–Specific Ca2+Current Profiles
Authors: Husch Andreas , Paehler Moritz , Fusca Debora , Paeger Lars , Kloppenburg Peter
Published: September 2009

A diverse population of local interneurons (LNs) helps to process, structure, and spatially represent olfactory information in the insect antennal lobe. In Periplaneta americana, we identified two subtypes of nonspiking local interneurons (type II LNs) by their distinct morphological and intrinsic electrophysiological properties. As an important step toward a better understanding of the cellular mechanisms that mediate odor information processing, we present a detailed analysis of their distinct voltage-activated Ca2+currents, which clearly correlated with their distinct intrinsic electrophysiological properties. Both type II LNs did not posses voltage-activated Na+currents and apparently innervated all glomeruli including the macroglomerulus. Type IIa LNs had significant longer and thicker low-order neurites and innervated each glomerulus entirely and homogeneously, whereas type IIb LNs innervated only parts of each glomerulus. All type II LNs were broadly tuned and responded to odorants of many chemical classes with graded changes in the membrane potential. Type IIa LNs responded with odor-specific elaborate patterns of excitation that could also include “spikelets” riding on the depolarizations and periods of inhibition. In contrast, type IIb LNs responded mostly with sustained, relatively smooth depolarizations. Consistent with the strong active membrane properties of type IIa LNs versus type IIb LNs, the voltage-activated Ca2+current of type IIa LNs activated at more hyperpolarized membrane potentials and had a larger transient component.
Filling-In, Spatial Summation, and Radiation of Pain: Evidence for a Neural Population Code in the Nociceptive System
Authors: Quevedo Alexandre S. , Coghill Robert C.
Published: September 2009

The receptive field organization of nociceptive neurons suggests that noxious information may be encoded by population-based mechanisms. Electrophysiological evidence of population coding mechanisms has remained limited. However, psychophysical studies examining interactions between multiple noxious stimuli can provide indirect evidence that neuron population recruitment can contribute to both spatial and intensity-related percepts of pain. In the present study, pairs of thermal stimuli (35°C/49°C or 49°C/49°C) were delivered at different distances on the leg (0, 5, 10, 20, 40 cm) and abdomen (within and across dermatomes) and subjects evaluated pain intensity and perceived spatial attributes of stimuli. Reports of perceived pain spreading to involve areas that were not stimulated (radiation of pain) were most frequent at 5- and 10-cm distances (χ2= 34.107, P < 0.0001). Perceived connectivity between two noxious stimuli (filling-in) was influenced by the distance between stimuli (χ2= 16.756, P < 0.01), with the greatest connectivity reported at 5- and 10-cm separation distances. Spatial summation of pain occurred over probe separation distances as large as 40 cm and six dermatomes ( P < 0.05), but was maximal at 5- and 10-cm separation distances. Taken together, all three of these phenomena suggest that interactions between recruited populations of neurons may support both spatial and intensity-related dimensions of the pain experience.
Poly(hydroxyalkanoates)‐Based Polymeric Nanoparticles for Drug Delivery
Authors: Errico Cesare , Bartoli Cristina , Chiellini Federica , Chiellini Emo
Published: September 2009

Poly (hydroxyalkanoates) (PHAs) have recently attracted a great deal of academic and industrial interest for their biodegradability and biocompatibility making them suitable for environmental and biomedical applications. Poly(3‐hydroxybutyrate‐) (PHB‐) and Poly(DL‐lactide‐co‐glycolide) (PLGA‐) based nanoparticles were prepared using the dialysis method as yet unreported for the preparation of nanoparticles based on PHB. Processing conditions were varied in order to evaluate their influence on morphology, drug encapsulation, and size of nanoparticles. The relevant results obtained give a theoretical understanding of the phenomenon occurring during colloidal formation. The adopted procedure allows for a relatively small diameter and homogeneity in size distribution of the PHB nanoparticles to be obtained compared to other methods like the one based on solvent evaporation which leads to particles on microscale. The biocompatibility of PHB and relative nanoparticles was investigated and both exhibited very good cytocompatibility.
Converged Digital TV Services: The Role of Middleware and Future Directions of Interactive Television
Authors: Tsekleves Emmanuel , Cosmas John , Aggoun Amar , Loo Jonathan
Published: September 2009

The subject of the future of the interactive Television medium has become a topic of great interest to the academic and industrial communities particularly since in the recent years there has been a dramatic increase in the pace of innovation of convergence of digital TV systems and services. The purpose of this paper is to provide a brief overview of what we know as digital TV converged services, to present and categorise the digital Television middleware technologies that contributed to it, and to present possible future trends and directions. A new Television era of converged wireless and mobile content delivery, user-authored content, multimodal interaction, intelligent personalisation, smart space awareness, and 3D content sensations is foreseen, creating ambient and immersive experiences.
Inhibitory Effects of the Ruthenium Complex KP1019 in Models of Mammary Cancer Cell Migration and Invasion
Authors: Bergamo A. , Masi A. , Jakupec M. A. , Keppler B. K. , Sava G.
Published: September 2009

The effects of indazoliumtrans-[tetrachlorobis(1H-indazole)ruthenate(III)] (KP1019, or FFC14A), the second ruthenium compound that entered clinical trials, in an in vitro model of tumour invasion and metastasis show that the antitumour effects of this compound might include also the modulation of cell behaviour although its cytotoxicity appears to be predominant over these effects. The comparison with its imidazole analogue KP418 shows however its superiority, being able to control in vitro cell growth and in some instances also in vivo tumour development. These results suggest that the activity of KP1019 is predominantly due to direct cytotoxic effects for tumour cells, evident also in vivo on primary tumour growth and that the effects on modulation of the biological behaviour of the cancer cell can be present but might have only a partial role.