bluuebunny/crossref_metadata_2025 huggingface dataset:
Female Sex Workers and the Social Context of Workplace Violence in Tijuana, Mexico
Authors: Katsulis Yasmina , Lopez Vera , Durfee Alesha , Robillard Alyssa
Published: September 2010

Gender‐based violence in the workplace impacts the physical and emotional well‐being of sex workers and may lead to other health problems, such as PTSD and depression, drug abuse, and a greater likelihood of sexually transmitted infections. This study examines the social context of workplace violence and risk avoidance in the context of legal regulations meant to reduce harms associated with the industry. Ethnographic research, including 18 months of extended field observations and interviews with 190 female sex workers, is used to illustrate how sex workers in Tijuana, Mexico, experience and manage workplace violence. Multiple subthemes emerge from this analysis, including deciding where to work, working with a third party, avoiding theft, and dealing with police. These findings support the idea that the risk of violence is part of a larger “hierarchy of risk” that can result in a “trade‐off” of harms.
Malaria, Danger, and Risk Perceptions among the Yao in Rural Malawi
Authors: Launiala Annika , Honkasalo Marja‐Liisa
Published: September 2010

Findings from a study designed to discover how local understanding of malaria among Yao in Malawi relate to pregnancy risk definitions reveal that malaria in pregnancy is not perceived as a major risk. Using extended ethnographic field research and multiple methods, we argue a shift from narrow single‐disease approaches to malaria during pregnancy is required and document women's concerns about exposure to multiple vulnerabilities during pregnancy, including witchcraft, extramarital affairs, and multiple dangerous illnesses. Four dimensions are implicated in Yao perceptions of risk: perceived adverse consequences in pregnancy; ease of treatment and cure; transmission and agency to control; and type of risk (social–medical). We discuss implications and consider malaria program features needed to address the complexity of perceived vulnerabilities and living conditions in resource‐poor settings.
Melatonin prevents hypertension and increased asymmetric dimethylarginine in young spontaneous hypertensive rats
Authors: Tain You‐Lin , Huang Li‐Tung , Lin I‐Chun , Lau Ying‐Tung , Lin Ching‐Yuang
Published: September 2010

Abstract:  Nitric oxide (NO) deficiency is associated with development of hypertension. We examined whether melatonin protects against the blood pressure increase is because of the restoration of the NO pathway. Spontaneous hypertensive rats (SHR) and control normotensive Wistar Kyoto (WKY) rats aged 4 weeks were assigned to four groups (N = 6 for each group): untreated SHR and WKY, melatonin‐treated SHR and WKY. Melatonin‐treated rats received 0.01% melatonin in drinking water for 8 wks. All rats were sacrificed at 12 wk of age. SHR had higher blood pressure than WKY, which melatonin prevented. Plasma asymmetric dimethylarginine (ADMA) levels were elevated in SHR, combined with a reduction in plasma L‐arginine to ADMA ratio (AAR). In the kidney, L‐arginine, ADMA, and AAR were not different between SHR and WKY rats, whereas L‐citrulline level was increased in SHR. Melatonin decreased plasma ADMA level and restored plasma AAR. Renal dimethylarginine dimethylaminohydrolase (DDAH, ADMA‐metabolizing enzyme) activity was lower in SHR than WKY rats, which melatonin therapy prevented. Also, melatonin elevated both L‐arginine and ADMA but reduced L‐citrulline level in the kidney in SHR, which was associated with the prevention of reduced renal argininosuccinate lyase (ASL) expression in SHR. Moreover, melatonin reduced the degree of oxidative damaged DNA product, 8‐ hydroxydeoxyguanosine (8‐OHdG) immunostaining in SHR. The observed antihypertensive effects of melatonin in young SHR are because of the restoration of the NO pathway by reduction of plasma ADMA, restoration of plasma AAR, preservation of renal L‐Arg availability, and attenuation of oxidative stress.
Effects of a 2‐year school‐based daily physical activity intervention on cardiovascular disease risk factors: the Sogndal school‐intervention study
Authors: Resaland G. K. , Anderssen S. A. , Holme I. M. , Mamen A. , Andersen L. B.
Published: September 2010

The aim of this study was to investigate the effect of a 2‐year school‐based physical activity (PA) intervention in 9‐year‐old children on cardiovascular disease (CVD) risk factors. One intervention school (I‐school) (n=125) and one control school (C‐school) (n=131) were included. The children at the I‐school carried out 60 min of PA daily. The PA lessons were planned, organized and led by expert physical education (PE) teachers. In the C‐school, children were offered the normal 45 min of PE twice weekly. The intervention resulted in a greater beneficial development in systolic (P=0.003) and diastolic (P=0.002) blood pressure, total cholesterol‐to‐high‐density lipoprotein cholesterol ratio (P=0.011), triglyceride (P=0.030) and peak oxygen uptake (P<0.001) in I‐school children than in C‐school children. No significant differences were observed in waist circumference, body mass index and the homeostasis model assessment for insulin resistance between the two groups. Furthermore, the intervention, primarily carried out at moderate intensity, had the strongest impact in children with the least favorable starting point. In conclusion, a daily school‐based PA intervention can beneficially modify children's CVD risk profile if the intervention has sufficient duration and includes a substantial amount of daily PA, and if the PA is implemented by expert PE teachers.
Leg and joint stiffness in human hopping
Authors: Kuitunen S. , Ogiso K. , Komi P. V.
Published: September 2010

The present study investigated the regulation of leg and joint stiffness in hopping at different intensity levels. Eight male subjects performed bilateral hopping at various intensity levels that were determined by peak vertical ground reaction force (GRF). In addition to the GRF, the measurements included hopping kinematics and electromyography (EMG) of selected leg muscles. While the leg and ankle joint stiffness remained invariant, the knee joint stiffness increased significantly (P<0.01) with the hopping intensity. EMG analysis revealed a significant increase in averaged EMG for all the measured muscles before and during the early phase of ground contact (P<0.05–0.001) with increasing hopping intensity. However, only the vastus lateralis muscle showed significant increase in stretch reflex EMG with increasing hopping intensity (P<0.01). The present study indicates that in hopping with short contact time the leg stiffness modulation is sensitive to changes in ankle joint stiffness and the role of knee joint stiffness is to regulate the jumping performance (height). Furthermore, our results suggest that leg and joint stiffness in hopping is mainly adjusted by centrally programmed motor commands and the contribution of stretch reflexes to muscle force output is muscle‐dependent.
Corneal curvature, pachymetry, and endothelial cell density in Marfan syndrome
Authors: Konradsen Tiina R. , Koivula Annemari , Kugelberg Maria , Zetterström Charlotta
Published: September 2010

Purpose:  To evaluate corneal curvature, pachymetry, and endothelial cell density (ECD) in Marfan syndrome (MFS).

Methods:  A case–control study in which K values, pachymetry, and ECD were compared in 39 MFS eyes and 40 control eyes matched for age and refraction was conducted. MFS eyes with lens subluxation also were compared with eyes without subluxation.

Results:  The mean Kmed value in MFS eyes was lower than in the control eyes, 42.2 ± 1.9 versus 43.4 ± 1.4 dioptres (D), respectively (p = 0.02). Fifteen MFS eyes (38%) and three control eyes (8%) had Kmed values below 41.5 D (p = 0.0012). MFS eyes had generally more corneal astigmatism than control eyes, 1.1 ± 0.9 versus 0.8 ± 0.4 D (p = 0.035), and MFS eyes with lens subluxation had more corneal astigmatism than those without, 1.6 ± 1.1 versus 0.6 ± 0.3 D (p = 0.0002). Nine MFS eyes with corneal astigmatism exceeding 1.5 D also had a subluxated lens. No eyes had keratoconus. The mean pachymetry value was lower in MFS eyes compared to the controls, 485 ± 54.5 versus 514 ± 37.3 μm (p = 0.007); 24 MFS eyes (62%) and 10 control eyes (25%) had measurements below 500 μm (p = 0.01). The mean ECD values were similar in MFS and control eyes, 2815 ± 430 versus 2858 ± 458 cells/mm2 (p = 0.66). The mean K value, pachymetry, and ECD values did not differ between MFS eyes with and without lens subluxation.

Conclusion:  Decreased K values and pachymetry could indicate MFS regardless of subluxation. High corneal astigmatism is associated with subluxation in MFS. Subluxation should be identified in MFS eyes with high corneal astigmatism.
Increased serum total antioxidant status and decreased urinary 8‐hydroxy‐2′‐deoxyguanosine levels in patients with normal‐tension glaucoma
Authors: Yuki Kenya , Murat Dogru , Kimura Itaru , Tsubota Kazuo
Published: September 2010

Acta Ophthalmol. 2010: 88: e259–e264

Purpose:  To investigate the amount of systemic oxidative stress‐related DNA damage and serum total antioxidant status of patients with normal‐tension glaucoma compared with healthy controls.

Methods:  Forty‐three patients with normal‐tension glaucoma selected from 60 consecutive newly diagnosed patients with primary open‐angle glaucoma were enrolled. Each patient’s intraocular pressure (IOP) was measured seven times over a 24‐hour period. Those whose highest IOP was over 21 mmHg were excluded. Forty control subjects were recruited. The serum total antioxidant status was assessed colorimetrically by its ability to reduce the generation of the radical cation ABTS (2,2‐azinobis‐3‐ethylbenzthiazoline sulphonate). The urinary 8‐hydroxy‐2′‐deoxyguanosine was measured as a marker of oxidative DNA damage and normalized to creatinine. The results were compared between healthy subjects and patients with normal‐tension glaucoma.

Results:  The control and normal‐tension glaucoma groups did now show significant differences for age, gender, serum fructosamine, cholesterol and triglyceride levels; systolic and diastolic blood pressure, body mass index; and prevalence of hypertension. The serum total antioxidant status was significantly higher (p = 0.01) and the urinary 8‐hydroxy‐2′‐deoxyguanosine/creatinine level significantly lower (p = 0.03) in the patients with normal‐tension glaucoma compared with the controls. Even after we adjusted the data for independent variables, the incidence of normal‐tension glaucoma was significantly correlated with high serum total antioxidant levels (p = 0.03; odds ratio, 1.007; 95% confidence interval, 1.001–1.013) and low urinary 8‐hydroxy‐2′‐deoxyguanosine/creatinine (p = 0.02; odds ratio 0.76; 95% confidence interval, 0.61–0.96).

Conclusions:  Increased serum total antioxidant and decreased 8‐hydroxy‐2′‐deoxyguanosine may reflect compensatory alterations in response to increased systemic oxidative stress in patients with normal‐tension glaucoma.
Effects of Age, Gender, and Emotional Labor Strategies on Job Outcomes: Moderated Mediation Analyses
Authors: Cheung Francis Yue‐lok , Tang Catherine So‐kum
Published: September 2010

Based on socioemotional selectivity theory (SST; Carstensen, Isaacowitz, & Charles, 1999), we examined the role of age on the selection of emotional labor strategies, and how the latter mediated the association between age / gender and job satisfaction as well as psychological health. We also examined whether gender would moderate the association between age and emotional labor strategies. Correlation results showed that age was related to the use of deep acting and the expression of naturally felt emotions. Furthermore, results showed that the conditional indirect effect of deep acting between age and job satisfaction was significant, and the significant effect was found in both gender groups. Limitations and practical implications are discussed.
Characterization and cytocompatibility of hybrid aminosilane-agarose hydrogel scaffolds
Authors: Sánchez-Vaquero V. , Satriano C. , Tejera-Sánchez N. , González Méndez L. , García Ruiz J. P. , Manso Silvána M.
Published: September 2010

Agarose hydrogels containing aminopropyl triethoxy silane (APTS) have been prepared and evaluated as scaffolds for adhesion and proliferation of human mesenchymal stem cells (hMSCs). The preparation of the hydrogels involved the conventional melting of agarose in water followed by addition of APTS as functional group carrier. The resulting hydrogel supports have been studied by Fourier transformed infrared spectroscopy in order to get an insight into the hybrid molecular structure. X-ray photoelectron spectroscopy has been used for the analysis of the surface chemical composition of the hydrogels. It is deduced from these data that the resulting hybrid structure presents two phases with a clear tendency toward APTS surface segregation. Moreover, the observation of the desiccated hydrogel surfaces by atomic force microscopy shows that the films acquire a filament-mesh structure for increasing APTS content, while the pure agarose supports exhibit a granular structure. As a result of such a structure, the hydrogel surfaces show a hydrophobic behavior, as determined by water contact angle measurements. The biocompatibility of such platforms is supported by adhesion-proliferation assays performed with hMSCs. It is concluded that although adhesion is lower on APTS rich scaffolds, the proliferation rate on these surfaces is higher so that total number of proliferating cells does not significantly depend on APTS content in the hydrogels.
UV laser-ablated surface textures as potential regulator of cellular response
Authors: Chandra Prafulla , Lai Karen , Sung Hak-Joon , Murthy N. Sanjeeva , Kohn Joachim
Published: September 2010

Textured surfaces obtained by UV laser ablation of poly(ethylene terephthalate) films were used to study the effect of shape and spacing of surface features on cellular response. Two distinct patterns, cones and ripples with spacing from 2 to 25 μm, were produced. Surface features with different shapes and spacings were produced by varying pulse repetition rate, laser fluence, and exposure time. The effects of the surface texture parameters, i.e., shape and spacing, on cell attachment, proliferation, and morphology of neonatal human dermal fibroblasts and mouse fibroblasts were studied. Cell attachment was the highest in the regions with cones at ≈4 μm spacing. As feature spacing increased, cell spreading decreased, and the fibroblasts became more circular, indicating a stress-mediated cell shrinkage. This study shows that UV laser ablation is a useful alternative to lithographic techniques to produce surface patterns for controlling cell attachment and growth on biomaterial surfaces.
A Transient and Low-Populated Protein-Folding Intermediate at Atomic Resolution
Authors: Korzhnev Dmitry M. , Religa Tomasz L. , Banachewicz Wiktor , Fersht Alan R. , Kay Lewis E.
Published: September 2010

Transient Protein Conformations

Transient conformations are important to protein function; however, detecting and characterizing these states is technically challenging.

Korzhnev
et al.

(p.
1312
; see the Perspective by

Al-Hashimi

) combined recently developed methods to determine the three-dimensional atomic-resolution structure of a transient intermediate of a four-helix bundle protein domain. The intermediate formed rapidly but, owing to structural peculiarities, slowly rearranged into its native state. The methods can be applied not only to folding intermediates but also to excited states important for protein function.
Septins at the Nexus
Authors: Barral Yves
Published: September 2010

The ability of a cytoskeletal protein to prevent membrane protein diffusion is important for cilia formation and maintenance.
Overbuilding Research Capacity
Authors: Alberts Bruce
Published: September 2010

Policies that offer incentives for individuals and institutions can unintentionally induce harmful behaviors. One such perverse incentive encourages U.S. universities, medical centers, and other research institutions to expand their research capacities indefinitely through funds derived from National Institutes of Health (NIH) research grants. A reliance on the NIH to pay not only the salaries of scientists but also the overhead (or indirect) costs of building construction and maintenance has become a way of life at many U.S. research institutions, with potential painful consequences. The current trajectory is unsustainable, threatening to produce a glut of laboratory facilities reminiscent of the real estate bust of 2008 and, worse, a host of exhausted scientists with no means of support.
Brazil Says Rate of Deforestation in Amazon Continues to Plunge
Authors: Regalado Antonio
Published: September 2010

Large-scale deforestation in the Amazon has declined by 47.5% over the past 12 months, according to a preliminary survey by the Brazilian Ministry of Environment using a low-resolution satellite.
Tending the Global Garden
Authors: Pennisi Elizabeth
Published: September 2010

By sorting out plant names and growing threatened species, botanic gardens are trying to do their part for plant conservation.
Saving Forests to Save Biodiversity
Authors: Normile Dennis
Published: September 2010

A hot spot for undiscovered flora and fauna, Indonesia is beginning to take steps to preserve its forests and its biological heritage.
Human Immunodeficiency Virus Type 1 Protease Inhibitor Drug-Resistant Mutants Give Discordant Results When Compared in Single-Cycle and Multiple-Cycle Fitness Assays
Authors: Dykes Carrie , Wu Hulin , Sims Matthew , Holden-Wiltse Jeanne , Demeter Lisa M.
Published: September 2010

The replication fitness of HIV-1 drug-resistant mutants has been measured using either multiple-cycle or single-cycle assays (MCAs or SCAs); these assays have not been systematically compared. We developed an MCA and an SCA that utilized either intact or
env
-deleted recombinant viral vectors, respectively, in which virus-infected cells were detected by flow cytometry of a reporter gene product. Fitness was measured using each assay for 11 protease mutants, 9 reverse transcriptase mutants, and two mutants with mutations in
gag
p6, which is important for the release of virus particles from the cell membrane. In the SCA, fitness (replication capacity [RC]) was defined as the proportion of cells infected by the mutant compared to the wild type 40 h after infection. MCA fitness (1+s) was determined by comparing the changes in the relative proportions of cells infected by the mutant and the wild type between 3 and 5 days after infection. Five protease mutants showed statistically different fitness values by the MCA versus the SCA: the D30N, G48V, I50V, I54L, and I54M mutants. When all the mutants were ranked in order from most to least fit for both assays, 4 protease mutants moved more than 5 positions in rank: the D30N, I54L, I54M, and V82A mutants. There were no significant differences in fitness for the
gag
p6 or reverse transcriptase mutants. We propose that discordant results in the MCA and SCA are due to alterations in late events in the virus life cycle that are not captured in an SCA, such as burst size, cell-to-cell transmission, or infected-cell life span.
Multicenter Evaluation of the BD Max GBS Assay for Detection of Group B Streptococci in Prenatal Vaginal and Rectal Screening Swab Specimens from Pregnant Women
Authors: Riedlinger Jennifer , Beqaj Safedin H. , Milish Marsha A. , Young Stephen , Smith Rebecca , Dodd Monique , Hankerd Rosemary E. , LeBar William D. , Newton Duane W.
Published: September 2010

A new integrated extraction and real-time PCR-based system for the detection of group B streptococci in antepartum screening samples enriched in Lim broth was compared to the CDC-recommended culture method. The BD Max GBS assay exhibited acceptable sensitivity (95%) and specificity (96.7%) compared to those of the culture method in this multisite evaluation.
Coagulase-Negative Staphylococcal Skin Carriage among Neonatal Intensive Care Unit Personnel: from Population to Infection
Authors: Hira Vishal , Sluijter Marcel , Goessens Wil H. F. , Ott Alewijn , de Groot Ronald , Hermans Peter W. M. , Kornelisse René F.
Published: September 2010

Coagulase-negative staphylococci (CoNS) are a major cause of sepsis in neonatal intensive care units (NICU) worldwide. Infecting strains of these commensal bacteria may originate from NICU personnel. Therefore, we studied the characteristics of CoNS isolates from NICU personnel and compared them to those of isolates from the general population and from sepsis patients. Furthermore, we studied the epidemiological effect on CoNS carriage of NICU personnel after a period of absence. In our study, we isolated CoNS from the thumbs of NICU personnel every 2 weeks during the summer of 2005 and sampled personnel returning from vacation and a control group from the general population. Furthermore, we collected sepsis isolates from this period. Isolates were tested for antibiotic resistance,
mecA
and
icaA
carriage, biofilm production, and genetic relatedness. We found that
mecA
and
icaA
carriage as well as penicillin, oxacillin, and gentamicin resistance were significantly more prevalent in CoNS strains from NICU personnel than in community isolates. Similar trends were observed when postvacation strains were compared to prevacation strains. Furthermore, genetic analysis showed that 90% of the blood isolates were closely related to strains found on the hands of NICU personnel. Our findings revealed that CoNS carried by NICU personnel differ from those in the general population. Hospital strains are replaced by community CoNS after a period of absence. NICU personnel are a likely cause for the cross-contamination of virulent CoNS that originate from the NICU to patients.
Single-Nucleotide Polymorphism in the
fadD28
Gene as a Genetic Marker for East Asia Lineage
Mycobacterium tuberculosis
Authors: Chuang Pei-Chun , Chen Huang-Yau , Jou Ruwen
Published: September 2010

Mycobacterium tuberculosis
isolates with a region of difference 105 (RD105) deletion, mainly Beijing family spoligotypes, were phylogenetically grouped into the East Asia lineage. We identified a single nucleotide polymorphism in codon 507, ATC to ATT, of the
fadD28
gene as a robust marker and developed a rapid assay for East Asia lineage
M. tuberculosis
.
High Prevalence of Clarithromycin Resistance and
cagA
,
vacA
,
iceA2
, and
babA2
Genotypes of
Helicobacter pylori
in Brazilian Children
Authors: Garcia Gabriella T. , Aranda Katia R. S. , Gonçalves Manoel E. P. , Cardoso Silvia R. , Iriya Kiyoshi , Silva Neusa P. , Scaletsky Isabel C. A.
Published: September 2010

We isolated 45
Helicobacter pylori
strains from 217 child patients. Resistance to clarithromycin, metronidazole, amoxicillin, and tetracycline was detected in 27%, 13%, 4%, and 0% of strains, respectively. The A2143G mutation was the most prevalent (67%) among clarithromycin-resistant strains. In addition, strain genotyping revealed a significant association between gastritis severity and the simultaneous presence of
cagA
,
vacA s1m1
,
iceA2
, and
babA2
genes.
Real-Time Detection of Influenza A, Influenza B, and Respiratory Syncytial Virus A and B in Respiratory Specimens by Use of Nanoparticle Probes
Authors: Jannetto Paul J. , Buchan Blake W. , Vaughan Kimberly A. , Ledford Joellen S. , Anderson Dennis K. , Henley Donald C. , Quigley Neil B. , Ledeboer Nathan A.
Published: September 2010

Seasonal epidemics of influenza and respiratory syncytial virus are responsible for significant morbidity and mortality worldwide. Infrequently, novel or reemergent strains of influenza A virus have caused rapid, severe global pandemics resulting in millions of fatalities. The ability to efficiently and accurately detect and differentiate respiratory viruses is paramount for effective treatment, infection control, and epidemiological surveillance. We evaluated the ability of two FDA-cleared nucleic acid-based tests, the semiautomated respiratory virus nucleic acid test (VRNAT) and the fully automated respiratory virus nucleic acid test
SP
(RVNAT

SP

) (Nanosphere Inc., Northbrook, IL) to detect influenza A virus, influenza B virus, and respiratory syncytial virus A and B (RSV A/B) from clinical nasopharyngeal swab specimens. Detection of viral RNA in both tests is based on nucleic acid amplification followed by hybridization to capture probes immobilized on a glass slide. A novel technology utilizing gold nanoparticle-conjugated probes is utilized to detect the presence of captured target DNA. This microarray-based approach to detection has proven to be more sensitive than the traditional culture/direct fluorescent-antibody assay (DFA) method for detecting RSV and influenza viruses in clinical specimens, including the novel 2009 H1N1 strain. Specifically, we report 98.0% sensitivity and 96.5% specificity for the VRNAT compared to culture/DFA. Further, the VRNAT detected virus in an additional 58% of specimens that were culture negative. These data were confirmed using bidirectional sequencing. Evaluation of the fully automated RVNAT

SP

, which is built on the same detection technology as the VRNAT but contains an updated processor enabling complete automation, revealed the two tests to be functionally equivalent. Thus, the RVNAT

SP

is a fully automated sample-to-result test capable of reliable detection of select respiratory viruses directly from clinical specimens in 3.5 h.
Generation of Replication-Competent Recombinant Influenza A Viruses Carrying a Reporter Gene Harbored in the Neuraminidase Segment
Authors: Li Feng , Feng Liqiang , Pan Weiqi , Dong Zhenyuan , Li Chufang , Sun Caijun , Chen Ling
Published: September 2010

Replication-competent influenza viruses carrying reporter genes are of great use for basic research, screening of antiviral drugs, and neutralizing of antibodies. In this study, two recombinant influenza A viruses with a neuraminidase (NA) segment harboring enhanced green fluorescent protein (EGFP) in the background of A/PR/8/34 (PR8) were generated. The viral RNA (vRNA)-specific packaging signals for NA were largely retained for efficient packaging. An “autocleave” 2A peptide sequence, which was inserted at the N terminus or the COOH terminus of NA to link with EGFP, enabled NA and EGFP to be expressed monocistronically. Further analysis demonstrated that both viruses, named rPR8-EGFP+NA and rPR8-NA+EGPF, although with some characteristic differences in growth and EGFP expression, could replicate in noncomplementary cells and propagate to large quantities while maintaining genome stability after multiple passages in embryonated eggs. These replication-competent influenza viruses carrying reporter genes are a great addition to the tool set for developing antiviral therapeutics and vaccines and for
in vivo
studies of viral dissemination and pathogenicity.
Infectivity of Hepatitis C Virus Is Influenced by Association with Apolipoprotein E Isoforms
Authors: Hishiki Takayuki , Shimizu Yuko , Tobita Reiri , Sugiyama Kazuo , Ogawa Kazuya , Funami Kenji , Ohsaki Yuki , Fujimoto Toyoshi , Takaku Hiroshi , Wakita Takaji , Baumert Thomas F. , Miyanari Yusuke , Shimotohno Kunitada
Published: September 2010

Hepatitis C virus (HCV) is a causative agent of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV in circulating blood associates with lipoproteins such as very low density lipoprotein (VLDL) and low-density lipoprotein (LDL). Although these associations suggest that lipoproteins are important for HCV infectivity, the roles of lipoproteins in HCV production and infectivity are not fully understood. To clarify the roles of lipoprotein in the HCV life cycle, we analyzed the effect of apolipoprotein E (ApoE), a component of lipoprotein, on virus production and infectivity. The production of infectious HCV was significantly reduced by the knockdown of ApoE. When an ApoE mutant that fails to be secreted into the culture medium was used, the amount of infectious HCV in the culture medium was dramatically reduced; the infectious HCV accumulated inside these cells, suggesting that infectious HCV must associate with ApoE prior to virus release. We performed rescue experiments in which ApoE isoforms were ectopically expressed in cells depleted of endogenous ApoE. The ectopic expression of the ApoE2 isoform, which has low affinity for the LDL receptor (LDLR), resulted in poor recovery of infectious HCV, whereas the expression of other isoforms, ApoE3 and ApoE4, rescued the production of infectious virus, raising it to an almost normal level. Furthermore, we found that the infectivity of HCV required both the LDLR and scavenger receptor class B, member I (SR-BI), ligands for ApoE. These findings indicate that ApoE is an essential apolipoprotein for HCV infectivity.
The Globoside Receptor Triggers Structural Changes in the B19 Virus Capsid That Facilitate Virus Internalization
Authors: Bönsch Claudia , Zuercher Christoph , Lieby Patricia , Kempf Christoph , Ros Carlos
Published: September 2010

Globoside (Gb4Cer), Ku80 autoantigen, and α5β1 integrin have been identified as cell receptors/coreceptors for human parvovirus B19 (B19V), but their role and mechanism of interaction with the virus are largely unknown. In UT7/Epo cells, expression of Gb4Cer and CD49e (integrin alpha-5) was high, but expression of Ku80 was insignificant. B19V colocalized with Gb4Cer and, to a lesser extent, with CD49e. However, only anti-Gb4Cer antibodies could disturb virus attachment. Only a small proportion of cell-bound viruses were internalized, while the majority became detached from the receptor. When added to uninfected cells, the receptor-detached virus showed superior cell binding capacity and infectivity. Attachment of B19V to cells triggered conformational changes in the capsid leading to the accessibility of the N terminus of VP1 (VP1u) to antibodies, which was maintained in the receptor-detached virus. VP1u became similarly accessible to antibodies following incubation of B19V particles with increasing concentrations of purified Gb4Cer. The receptor-mediated exposure of VP1u is critical for virus internalization, since capsids lacking VP1 could bind to cells but were not internalized. Moreover, an antibody against the N terminus of VP1u disturbed virus internalization, but only when present during and not after virus attachment, indicating the involvement of this region in binding events required for internalization. These results suggest that Gb4Cer is not only the primary receptor for B19V attachment but also the mediator of capsid rearrangements required for subsequent interactions leading to virus internalization. The capacity of the virus to detach and reattach again would enhance the probability of productive infections.
Quantifying Antigenic Relationships among the Lyssaviruses
Authors: Horton D. L. , McElhinney L. M. , Marston D. A. , Wood J. L. N. , Russell C. A. , Lewis N. , Kuzmin I. V. , Fouchier R. A. M. , Osterhaus A. D. M. E. , Fooks A. R. , Smith D. J.
Published: September 2010

All lyssaviruses cause fatal encephalitis in mammals. There is sufficient antigenic variation within the genus to cause variable vaccine efficacy, but this variation is difficult to characterize quantitatively: sequence analysis cannot yet provide detailed antigenic information, and antigenic neutralization data have been refractory to high-resolution robust interpretation. Here, we address these issues by using state-of-the-art antigenic analyses to generate a high-resolution antigenic map of a global panel of 25 lyssaviruses. We compared the calculated antigenic distances with viral glycoprotein ectodomain sequence data. Although 67% of antigenic variation was predictable from the glycoprotein amino acid sequence, there are in some cases substantial differences between genetic and antigenic distances, thus highlighting the risk of inferring antigenic relationships solely from sequence data at this time. These differences included epidemiologically important antigenic differences between vaccine strains and wild-type rabies viruses. Further, we quantitatively assessed the antigenic relationships measured by using rabbit, mouse, and human sera, validating the use of nonhuman experimental animals as a model for determining antigenic variation in humans. The use of passive immune globulin is a crucial component of rabies postexposure prophylaxis, and here we also show that it is possible to predict the reactivity of immune globulin against divergent lyssaviruses.
Functional Sindbis Virus Replicative Complexes Are Formed at the Plasma Membrane
Authors: Frolova Elena I. , Gorchakov Rodion , Pereboeva Larisa , Atasheva Svetlana , Frolov Ilya
Published: September 2010

Formation of virus-specific replicative complexes (RCs) in infected cells is one of the most intriguing and important processes that determine virus replication and ultimately their pathogenesis on the molecular and cellular levels. Alphavirus replication was known to lead to formation of so-called type 1 cytopathic vacuoles (CPV1s), whose distinguishing feature is the presence of numerous membrane invaginations (spherules) and accumulation of viral nonstructural proteins (nsPs) at the cytoplasmic necks of these spherules. These CPV1s, modified endosomes and lysosomes, were proposed as the sites of viral RNA synthesis. However, our recent studies have demonstrated that Sindbis virus (SINV)-specific, double-stranded RNA (dsRNA)- and nonstructural protein (nsP)-containing RCs are initially formed at the plasma membrane. In this new study, we present extensive evidence that (i) in cells of vertebrate origin, at early times postinfection, viral nsPs colocalize with spherules at the plasma membrane; (ii) viral dsRNA intermediates are packed into membrane spherules and are located in their cavities on the external surface of the plasma membrane; (iii) formation of the membrane spherules is induced by the partially processed nonstructural polyprotein P123 and nsP4, but synthesis of dsRNA is an essential prerequisite of their formation; (iv) plasma membrane-associated dsRNA and protein structures are the active sites of single-stranded RNA (ssRNA) synthesis; (v) at late times postinfection, only a small fraction of SINV nsP-containing complexes are relocalized into the cytoplasm on the endosome membrane. (vi) pharmacological drugs inhibiting different endocytotic pathways have either only minor or no negative effects on SINV RNA replication; and (vii) in mosquito cells, at any times postinfection, dsRNA/nsP complexes and spherules are associated with both endosomal/lysosomal and plasma membranes, suggesting that mechanisms of RC formation may differ in cells of insect and vertebrate origins.
The DAN method for calculation of vapour-liquid equilibria using an equation of state; Bubble and dew point calculations
Authors: Novák Josef P. , Růžička Vlastimil , Malijevský Anatol , Matouš Jaroslav , Linek Jan
Published: September 2010

A modification of the computational technique for calculating bubble and dew points using an equation of state has been proposed. The procedure consists in the Double Application of the Newton-Raphson method (DAN) to the set of equilibrium conditions. The algorithm is very effective as it provides both values of equilibrium variables and a very qualified first estimate of the next equilibrium point. This enables to proceed along the phase envelope rather quickly and to achieve convergence within a few iterations except in the close vicinity of the critical point.
Reaction of thioamides with 2,3-dichloro-1,4-naphthoquinone. A novel synthesis of naphtho[2,3-d]thiazole-4,9-diones
Authors: Hammam A. S. , Bayoumy B. E.
Published: September 2010

The reaction of thioamide II with 2,3-dichloro-1,4-naphthoquinone (I) in ethanol gave naptho[2,3-d]thiazole-4,9-diones (IV). The intermediates, 2-thioamido-3-chloro-1,4-naphthoquinones III were also isolated from the reaction medium and could be separately transformed to IV by further boiling in aqueous ethanol containing bicarbonate. The reaction of thiosemicarbazide with I under similar conditions gave naphtho[2,3-e]-2-amino-4H-1,3,4-thiadiazine-5,10-dione (VII).
Oxidation and epoxidation of 4,4-dimethyl-A-homo-5-cholesten-4a-ols
Authors: Velgová Helena , Zajíček Jaroslav
Published: September 2010

Oxidation of four stereoisomeric 3-acetoxy-4,4-dimethyl-A-homo-5-cholesten-4a-ols I-IV with Sarett's and Jones's reagent was investigated. 4αβ-Hydroxy derivatives II and IV afforded corresponding enones V and XVI as the main products, while in the case of 4aα-hydroxy derivatives I and III the formation of 5β,6β-epoxides was observed both in the oxidation according to Jones and in the oxidation with the Sarett's reagent. The study of the stereochemistry of epoxidation of olefins I-IV and their derivatives showed that the epoxidation of the 5,6-double bond takes place preferentially from the β-side of the cyclic system. On the basis of 1H NMR data the preferred conformation of the seven-membered ring A in the allylic alcohols I-IV was determined; on its basis the effects leading to different behaviour of epimers I, III and II, IV during oxidation are discussed.
Oxytocin analogues with inhibitory properties, containing in position 2 a hydrophobic amino acid of D-configuration
Authors: Lebl Michal , Barth Tomislav , Servítová Linda , Slaninová Jiřina , Jošt Karel
Published: September 2010

Ten analogues derived from oxytocin, deamino-oxytocin and deamino-carba-oxytocin were prepared which contained a D-amino acid in the position 2 of the parent system. The following D-amino acids were introduced: tyrosine, phenylalanine, p-methylphenylalanine, p-ethylphenylalanine and O-ethyltyrosine. Combination of two structural features which alone lead to strong inhibitors (a suitable D-amino acid in position 2 and a penicillamine moiety in position 1) did not enhance the inhibitory effect. Compounds containing D-tyrosine are weak agonists in the uterotonic assay; in case of 1-carba-analogues they can be converted into sulfoxides with low inhibitory activity. Analogues with D-phenylalanine substituted in the para-position are the most potent antagonists of the uterotonic effect of oxytocin (pA2 = 8.73) in vitro.
Influence of the carbohydrate moiety on rotational correlation time and hydrodynamic volume of cow colostrum trypsin inhibitor
Authors: Štrop Petr , Jonáková Věra
Published: September 2010

A large polysaccharide moiety of the cow colostrum trypsin inhibitor was removed by enzymatic cleavage; fully active protein was obtained by affinity chromatography. Rotational correlation times of the inhibitor labelled by dansyl chloride obtained from fluorescence depolarization measurements and hydrodynamic volumes from gel-permeation chromatography for protein with and without polysaccharide were compared with those of homologous Kunitz inhibitor. The mean rotational correlation time 105 ns and apparent mol. weight 16 000 were obtained for the colostrum inhibitor with polysaccharides; these values are considerably reduced to 44 ns and 8 700 dalton after removal of the polysaccharide moiety. For the pancreatic inhibitor an about four times shorter correlation time of 24 ns was obtained.
Secondary steric effects in 2,4,6-trialkylated acetophenones and nitrobenzenes: Dipole moments and 13C NMR spectra
Authors: Koudelka Juraj , Šaman David , Exner Otto
Published: September 2010

Dipole moments of 2,4,6-trialkylated acetophenones (II) and bromobenzenes (III) with variable size of the alkyl groups were measured in two solvents. The main intention was to shed more light on the previous results with similarly substituted nitrobenzenes (I). The comparison reveals a steady decrease of the dipole moment with the increasing size of the alkyl group in all three series. In addition, there is a stronger effect of steric inhibition of mesomerism in the series II and a comparably strong effect of the anisotropic polarizability in I; the two cannot be distinguished on the basis of dipole moments. Similarly an analysis of 13C NMR shifts reveals at least two effects. In one of them the series I behaves like III, in the other like II. Summarizing, our results are in agreement with the conception of negligible conjugation of the nitro group but they do not contribute significantly to its evidence which is based mainly on other physical quantities.
Structure-activity studies on open-chain analogues of nucleosides: Inhibition of S-adenosyl-L-homocysteine hydrolase and antiviral activity 2. Acid open-chain analogues
Authors: Holý Antonín , Votruba Ivan , De Clercq Erik
Published: September 2010

Over 50 ω-carboxyalkyl derivatives of adenine and other purine bases were examined for their inhibitory effects on rat liver S-adenosyl-L-homocysteine hydrolase and their antiviral activity. To be an inhibitor of SAH-hydrolase the analogue must contain an adenine base substituted at the position 9 by an ω-carboxyalkyl (C3-C5) chain bearing at least one hydroxyl function. The absolute configuration at the side-chain is decisive for the dihydroxy and trihydroxy compounds, but less important for the monohydroxyalkanoic acids. D-Eritadenine (1a) and 3-(adenin-9-yl)-2-hydroxypropanoic acids (12a) are the most potent SAH-hydrolase inhibitors and the only compounds possessing an antiviral activity (against vesicular stomatitis, parainfluenza type 3, reovirus type 1, and vaccinia virus). All these compounds effect a rapid irreversible inactivation of SAH-hydrolase. The esters of 1a and 12a exhibit little, if any inhibitory activity toward the enzyme; they are, however, much more potent antiviral agents than the parent compounds 1a and 12a, most probably acting as prodrugs of the latter. 2-Amino-D-eritadenine, (2R,3R)-5-(adenin-9-yl)-2,3-dihydroxypentanoic acid, 9-(dicarboxymethyl)adenine, 4-(adenin-9-yl)-2-hydroxybutanoic acid, 3-(8-bromoadenin-9-yl)-2-hydroxypropanoic acid and O-carboxymethyl derivatives of 9-(2,3-dihydroxypropyl)- and 9-(2,3,4-trihydroxybutyl)adenine are described as novel compounds.
Structural analogues of 5,6-tetramethyleneuracil ribosides - Inhibitors of enzymes participating in nucleic acid synthesis
Authors: Dramiński Marcin , Frass Elżbieta , Greger Janusz , Fabianowska-Majewska Krystyna
Published: September 2010

1-N and 3-N ribosyl, allyl and (RS)-2',3'-dihydroxypropyl derivatives of 5,6-tetramethyleneuracil were prepared. Some of described compounds are inhibitors of enzymes involving in regulation of DNA synthesis.
Effect of thuringiensis on the initiation of in vitro RNA synthesis
Authors: Horská Květoslava , Šebesta Karel
Published: September 2010

Thuringiensin, a structural analog of ATP, which inhibits the elongation phase of RNA synthesis catalyzed by DNA-dependent RNA polymerase, also inhibits the initiation phase of this reaction. During the latter thuringiensin is not incorporated into the first site of the chain synthesized but inhibits the formation of pApU from 5'-AMP and UTP. If ATP and UTP are used as substrates the amount of the dinucleotide, a product of abortive synthesis, increases at low thuringiensin concentrations. Both elongation and abortive synthesis are inhibited at higher concentrations of the inhibitor.
Measurement and interpretation of infrared and raman spectra of bis(2,4-pentandionate)complexes of Cu(II) and Pd(II)
Authors: Vlčková Blanka , Strauch Bohuslav , Horák Milan
Published: September 2010

Infrared and Raman spectra of Cu(II) bis(2,4-pentandionate) and Pd(II) bis(2,4-pentandionate) complexes have been measured and interpreted. The coincidence of numerous bands in the IR and Raman spectra has been explained by the isolation effect of the heavy central metal atom which prevents the vibrational interaction of the two ligands in the chelate molecule with each other. An 11-particle model consisting of all the atoms of one ligand (both CH3 groups are taken as the point masses), a central metal atom and two oxygen atoms of the other ligand has been proved to be most adequate for the empirical interpretation of the spectra.
Bond properties of anionic mixed halogeno-complexes InX3Y- (X ≠ Y = Cl, Br, I)
Authors: Singh D. R. , Verma U. P. , Pandey A. N. P. , Strauch Bohuslav
Published: September 2010

The normal coordinate analysis has been performed for the anionic mixed halogeno-complexes InX3Y- (X ≠ Y = Cl, Br, I). The trends among the force constants are discussed and the assignments of the observed fundamental frequencies are examined thoroughly. It has been found that the present analysis provides reliable data to introduce a light into the bond properties of InX3Y- ions. In addition to this the mean amplitudes of vibrations, bond order and bond polarizability derivatives have been studied for the systems under investigation and a comparison of bond parameters among the halides of indium are made.
Molecular parameters of dihalides of IIB group elements
Authors: Pandey A. N. P. , Strauch Bohuslav , Verma U. P. , Singh D. R.
Published: September 2010

The molecular parameters, i.e. force constants, mean amplitudes of vibrations, bond polarizability derivatives and mean molecular polarizabilities have been studied for MX2 and MXZ (M = Zn, Cd, Hg; X or Z = F, Cl, Br, I but X ##f Z) type halides of zinc group elements on the basis of current available spectroscopic and structural data. The analysis of the result for CdFBr demands a reinvestigation of the spectroscopic study in detail. The results of the present investigations will be helpful in the interpretation of the Raman intensity and refractometry data whenever available.
Highly polar potential metabolites of the neuroleptic agent oxyprothepin: Synthesis of 2-hydroxy-8-methylsulfonyl and 3-hydroxy-8-methylsulfonyl derivatives of 10-[4-(3-hydroxypropyl)piperazino]-10,11-dihydrodibenzo[b,f]thiepin
Authors: Jílek Jiří , Holubek Jiří , Svátek Emil , Schlanger Jiří , Pomykáček Josef , Protiva Miroslav
Published: September 2010

The acid XI, obtained by reaction of (2-iodo-5-methoxyphenyl)acetic acid with 4-(methylsulfonyl)thiophenol (VIII) in dimethylformamide in the presence of potassium carbonate and copper, was transformed via intermediates XIIa-XIVa to compound XVa. Demethylation with boron tribromide afforded compound III, the potential metabolite of oxyprothepin (II). Its oxidation with hydrogen peroxide in acetic acid gave the sulfoxide XVII, which is a further potential metabolite. A reaction of 2-iodo-4-methoxybenzoic acid with VIII and potassium carbonate in dimethylformamide in the presence of copper afforded the acid XIX whose ester XXI was reduced with diborane to the alcohol XXII; hydrogenolysis to compound XXIII was also observed. The

alcohol XXII was processed via compounds XXIV and XXV to the acid XXVI which was cyclized in a low yield to the ketone XIIb. A further processing via the intermediates XIIIb and XIVb led to compound XVb. Demethylation gave compound IV, another potential metabolite.
Spectrophotometric study of the reaction of alizarin green series dyes with uranyl ions in the presence of cationoid surfactants
Authors: Šimek Jiří , Son Nguyen Truong , Ružička Eduard
Published: September 2010

The coordination properties of alizarin green series dyes with uranyl ions were studied in the presence of cationoid surfactants (cetylpyridinium bromide, carbethoxypentadecyltrimethylammonium bromide). Ternary complexes of the composition UO2L2S2, UO2L2S4, UO2L2S6, and UO2L3S9, where L is dye and S is surfactant, are formed in weakly acid solutions. The formation constants of the complexes were established and a procedure was worked out for the direct photometric determination of uranium.