bluuebunny/crossref_metadata_2025 huggingface dataset:
Partial characterization of eosinophilic granule cells (EGCs) and identification of mast cells of the intestinal lamina propria in rainbow trout (Oncorhynchus mykiss). Biochemical and cytochemical study
Authors: Sire Marie‐France , Vernier Jean‐Marie
Published: February 2012

Summary— The role of intestinal eosinophilic granule cells (EGCs) is still a subject of discussion. The aim of this study was to obtain additional functional data for a better characterization of these cells. Biochemical studies indicated the presence of small amounts of histamine, a characteristic and consistent marker of mast cells, in the posterior gut. On the other hand, histamine is always absent from homogenates of isolated EGCs. Using colorimetric assays, we were able to show aryl sulphatase B activity (18.5 ± 3.7 nM nitrocatechol/106 cells) and detected peroxidase (1.86 ± 0.03 ng/106 cells) in EGC homogenates. A cytochemical study enabled us to localize peroxidase in the granules of EGCs. These cells can also phagocytose latex beads. EGCs should thus be considered as homologous with mammalian eosinophils and not with mast cells. The screening for cells in the mucosae containing chondroitin sulphate revealed sparsely represented cells in the loose connective tissue in immediate proximity to blood capillaries. These cells could be mucosal mast cells.
Transverse‐axial tubular system in guinea pig ventricular cardiomyocyte: 3D reconstruction, quantification and its possible role in K+ accumulation‐depletion phenomenon in single cells
Authors: Amsellem Jacqueline , Delorme Richard , Souchier Catherine , Ojeda Carlos
Published: February 2012

Summary— K+ accumulation‐depletion (AD) phenomena were found in single guinea pig ventricular myocytes using the patch‐clamp method in whole cell configuration. We suggest that the cardiomyocyte transverse‐axial tubular system (TATS) lumen is the restricted extracellular space where the K+ AD could take place. A three‐dimensional (3D) reconstruction of the TATS in a cardiomyocyte segment from serial ultrafine sections was made by three‐dimensional isosurface rendering and quantitative data were obtained from the image processing. This original approach of the TATS intricated network gave a new vision of this membrane system; moreover, quantitative data about the tubular membrane importance (52.6% of the total plasma membrane) and its surface area versus the tubular volume fraction (STATS/VTATS = 13.5 μm2/μm3 would fit in the electrophysiological results. The hypothesis whereby this ‘extracellular’ compartment could play, in single cells, a role as important as that of narrow clefts in the whole heart is discussed.
Calcium‐dependent peripheral localization of 4.1‐like proteins and fodrin in cultured human keratinocytes
Authors: Shimizu Tadamichi , Takakuwa Yuichi , Koizumi Hiroko , Ishibashi Teruo , Ohkawara Akira
Published: February 2012

Summary— Recently, several proteins immunologically related to erythrocyte membrane skeletal proteins, such as protein 4.1 and fodrin (non‐erythroid spectrin), have been found in keratinocytes. In the present study, in order to investigate the roles of these proteins in cell‐cell contact, we analyzed the distribution of non‐erythroid protein 4.1, β‐fodrin and actin in cultured human keratinocytes at low (0.15 mM) and standard (1.85 mM) Ca2+ concentrations. Immunofluorescence microscopy revealed that immunoreactive forms of protein 4.1, β‐fodrin and actin filaments were present in the cytoplasm of cells cultured in low Ca2+ medium, while in cells in the standard Ca2+ medium, these proteins were localized at the cell boundary and partially in the cytoplasm. When cells in the low‐Ca2+ medium were treated with 100 nM 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) for 1 h, these proteins were also present at the cell boundary. Increasing extracellular Ca2+ concentration from low to standard in the medium induces cell‐cell contact among the cultured human keratinocytes, accompanied by the translocation of protein 4.1 and β‐fodrin from the cytoplasm to the membrane. On the basis of the present study, movement of membrane skeletal proteins from the cytosol to the membrane suggests that either these proteins or the membrane skeletal lattice plays an important role in the regulation of cell‐cell intergigitations in response to changes in the Ca2+ concentrations in culture medium, and that phosphorylation of these skeletal proteins might be involved in the regulation of the membrane skeletal proteins of keratinocytes in response to Ca2+.
Smooth muscle‐type myosin heavy chain isoforms in bovine smooth muscle and non‐muscle tissues
Authors: Chiavegato Angela , Pauletto Paolo , Sartore Saverio
Published: February 2012

Summary— The distribution of smooth muscle (SM)‐type myosin heavy chain isoforms in several bovine muscular and non‐muscular (NM) tissues was evaluated by immunofluorescence tests using monoclonal antibodies SM‐E7, reactive with 204 (SM1) and 200 (SM2) kDa isoforms, and SM‐F11, specific for SM2 isoform. SM‐E7 reacted equally with vascular, respiratory and intestinal SM tissues, whereas SM‐F11 stained heterogeneously SM cells in the various muscular systems examined and in some peculiar tissues was unreactive (perisinusoidal cells of hepatic lobule, pulmonary interstitial cells and intestinal muscularis mucosae) or uniquely reactive (nerve cells). On the whole, our findings indicate that SM1 and SM2 isoforms are unequally distributed at the cellular level in various SM and NM tissues and support previous results obtained with tissue extracts and electrophoretic procedures.
Glycosaminoglycan metabolism in otosclerotic bone cells
Authors: Locci P. , Becchetti E. , Venti G. , Lilli C. , Marinucci L. , Donti E. , Paludetti G. , Maurizi M.
Published: February 2012

Summary— Normal and otosclerotic bone cells were cultured in vitro in serum‐free medium to evaluate single glycosaminoglycan (GAG) class synthesis and secretion. Moreover, the degradative process was studied by inhibiting the lysosomal functions through the addition of ammonium chloride to the cultures, an ammine known to inhibit lysosomal degradation by neutralizing organelle activity. Otosclerotic bone cells accumulated a lower amount of GAG both in the cellular and extracellular pool compared to normal ones. The decrease was markedly higher for secreted GAG. Moreover a different pattern of single GAG class distribution was observed in the two cell types considered. In the medium of otosclerotic cells a percentage increase of hyaluronic acid (HA) and dermatan sulphate (DS) and a percentage decrease of heparan sulfate (HS) and chondroitin sulfate (CS) were observed compared to normal bone cells. Ammonium chloride had a lower effect on pathologic than on normal cells, indicating a decrease in the degradative process in otosclerotic bone cells. These results were also confirmed by the experiments on GAG uptake and degradation and by the dosage of enzymatic activity of two exoglycosidases. Since extracellular GAG composition influences bone deposition and mineralization, these data support the hypothesis that otosclerosis is the result of an error in the connective tissue matrix structure.
Regional distribution of maternal mRNA sox‐19 in the zebrafish early embryo
Authors: Santacruz Hélène , Vriz Sophie
Published: February 2012

Summary— Asymmetric distribution of mRNA has been associated with polarisation and cell fate determination during early development of animal embryos. In this report we determine the distribution pattern of Zf‐Sox 19 mRNA during early embryogenesis of zebrafish. Zf‐Sox 19 mRNA is found in one pole of the embryo at the 8‐cell stage and in the deep cell layer close to the yolk, perhaps under the influence of yolk determinants. Zf‐Sox 19 is the earliest gene in zebrafish development whose RNA shows a restricted localisation. This result indicates that the first eight blastomeres are not equivalent in their molecular components.
Outcome of hepatectomy in super‐elderly patients with hepatocellular carcinoma
Authors: Yamada Shinichiro , Shimada Mitsuo , Miyake Hidenori , Utsunomiya Tohru , Morine Yuji , Imura Satoru , Ikemoto Tetsuya , Mori Hiroki , Hanaoka Jun , Iwahashi Shuichi , Saito Yu
Published: February 2012

Aim:  The aim of this study was to investigate the characteristics of super‐elderly hepatocellular carcinoma (HCC) patients aged 80 years or more who underwent hepatectomy and to clarify whether elderly patients with HCC benefit from hepatectomy.

Methods:  Between March 1992 and December 2008, 278 patients who underwent curative hepatectomy for HCC were investigated. Super‐elderly patients were defined as those aged 80 years or more. Clinicopathological data and outcomes after hepatectomy were compared between super‐elderly and non‐super‐elderly groups.

Results:  Preoperative parameters, such as biochemical examinations, and liver function tests in the non‐super‐elderly group were comparable with those of the super‐elderly group (n = 11). Exceptionally, albumin level in the super‐elderly group was lower than that in the non‐super‐elderly group (P = 0.03). Surgical data and the prevalence of postoperative complications did not differ significantly between the two groups. No mortality was observed in the super‐elderly and non‐super‐elderly group.

Conclusions:  Hepatectomy for HCC was a feasible option even in super elderly patients aged 80 years or older with accurate selection.
Evaluation of a wireless ambulatory capsule (SmartPill®) to measure gastrointestinal tract pH, luminal pressure and temperature, and transit time in ponies
Authors: STOKES A. M. , LAVIE N. L. , KEOWEN M. L. , GASCHEN L. , GASCHEN F. P. , BARTHEL D. , ANDREWS F. M.
Published: February 2012

Reasons for performing study: This study investigated the use of a wireless ambulatory capsule (WAC; SmartPill® pH.p GI Monitoring System) to determine WAC‐gastric emptying time (GET) in ponies.

Objectives: To measure WAC‐GET and compare it to those findings with GET assessed by nuclear scintigraphy (S‐GET).

Hypothesis: WAC‐GET will be slower than S‐GET, but will be significantly correlated.

Methods: Seven healthy adult mixed‐breed pony mares were used in this study. Feed was withheld for 12 h prior to the WAC administration. After administration, a complete‐feed diet was fed to allow the WAC to pass into the stomach. Luminal pH, temperature and pressure were collected by a modified receiver secured to the pony. Once the pH reached a value of ≥8.0, it was determined that gastric emptying had occurred, and ponies were fed grass hay. After 5 days, data were downloaded and analysed using proprietary software. During the second period of the study, after at least 2 weeks, 4 of the ponies underwent a standard S‐GET test.

Results: The WAC was successfully administered, and data were collected from all ponies. The mean percentage of data packets collected by the receiver was 84.9 ± 3.51% (range 66.8–95.1%). Mean WAC‐GET was 7.38 h (range 0.15–46.65 h). Mean gastric pH was 4.75 (range 2.07–6.99). Mean small intestinal transit time was 4.6 h. The mean pH for the small intestine was 8.0. The mean S‐GET time (in hours) when 10% of the radioactive feed is present in the stomach (T‐90%) was 2.3 h. The S‐GET did not correlate significantly with the WAC‐GET.

Conclusions and potential relevance: The WAC was safely administered to ponies, and data were collected using a modified receiver. The WAC‐GET varied considerably between ponies, but was ≤3 h in 5 of the 6 ponies. The WAC used in this study provided a noninvasive technique that produced novel information about the pony gastrointestinal tract, but owing to the substantial variability in GET values and long transit time it may not be a reliable clinical tool at this time.
Critical Situations of Vessel Operations in Short Crested Seas—Forecast and Decision Support System
Authors: Clauss Günther F. , Kosleck Sascha , Testa Daniel
Published: February 2012

The encounter of extreme waves, extreme wave groups, or unfavorable wave sequences poses dangerous threats for ships and floating/stationary marine structures. The impact of extreme waves causes enormous forces, whereas an unfavorable wave sequence—not necessarily extreme waves—can arouse critical motions or even resonance, often leading to loss of cargo, ship, or crew. Thus, besides a well thought-out maritime design, a system detecting critical incoming wave sequences in advance can help avoiding those dangerous situations, increasing the safety of sea transport or offshore operations. During the last two years a new system for decision support onboard a ship or floating/fixed marine structure named CASH—Computer Aided Ship Handling—has been introduced. The preceding papers showed the step wise development of the main components of the program code—3d-wave forecast and 3d-ship motion forecast. These procedures provide a deterministic approach to predict the short crested seas state within radar range of the ship, as well as resulting ship motions in six degrees of freedom. Both methods have been enhanced with special focus on the speed of calculation to ensure a just-in-time forecast. A newly developed component is the adaptive 3d-pressure distribution. This method calculates the pressure distribution along the wetted surface of the ship hull using a newly developed stretching approach. With the end of the joint project Loads on Ships in Seaway (LaSSe), (funded by the German Government) the paper presents the CASH system, giving the possibility to detect critical situations in advance. Thus not only decision support onboard a cruising ship can be provided, but also time windows for offshore operations are identified well in advance.
An Experimental and Numerical Study on the Axial Compression Response of Flexible Pipes
Authors: de Sousa José Renato M. , Viero Paula F. , Magluta Carlos , Roitman Ney
Published: February 2012

This paper deals with a nonlinear three-dimensional finite element (FE) model capable of predicting the mechanical response of flexible pipes subjected to axisymmetric loads focusing on their axial compression response. Moreover, in order to validate this model, experimental tests are also described. In these tests, a typical 4 in. flexible pipe was subjected to axial compression until its failure is reached. Radial and axial displacements were measured and compared to the model predictions. The good agreement between all results points out that the proposed FE model is effective to estimate the response of flexible pipes to axial compression and; furthermore, has potential to be employed in the identification of the failure modes related to excessive axial compression as well as in the mechanical analysis of flexible pipes under other types of loads.
An Experimental Investigation of the Efficiency of Planetary Gear Sets
Authors: Talbot David C. , Kahraman Ahmet , Singh Avinash
Published: February 2012

In this paper, results from an experimental study on power losses of planetary gear sets are presented. The experimental setup includes a specialized test apparatus to operate a planetary gear set under tightly controlled speed, load and oil temperature conditions, and instrumentation for an accurate measurement of power losses. The test matrix consisted of gear sets having three–six planets under loaded and unloaded conditions in order to separate load independent (spin) and load dependent (mechanical) power losses. The test matrix also included tests with planet gears having two levels of tooth surface roughness amplitudes as well as tests at varying oil inlet temperature. The results clearly indicate that spin power loss decreases with both reduction of number of planets and increase in oil temperature. Meanwhile, the mechanical power loss decreases with a decrease in oil temperature and reduction in gear surface roughnesses. Results also indicate that mechanical losses can be described by the power transmitted and lost by each planet branch.
Comment on “Abiotic Pyrite Formation Produces a Large Fe Isotope Fractionation”
Authors: Czaja Andrew D. , Johnson Clark M. , Yamaguchi Kosei E. , Beard Brian L.
Published: February 2012

Guilbaud
et al
. (Reports, 24 June 2011, p. 1548) suggest that the geologic record of Fe isotope fractionation can be explained by abiological precipitation of pyrite. We argue that a detailed understanding of the depositional setting, mineralogy, and geologic history of Precambrian sedimentary rocks indicates that the Fe isotope record dominantly reflects biological fractionations and Fe redox processes.
Coercive Citation in Academic Publishing
Authors: Wilhite Allen W. , Fong Eric A.
Published: February 2012

Many journal editors appear to strategically target authors and papers to pressure them into citing the editors' journals.
Abnormal Brain Structure Implicated in Stimulant Drug Addiction
Authors: Ersche Karen D. , Jones P. Simon , Williams Guy B. , Turton Abigail J , Robbins Trevor W. , Bullmore Edward T.
Published: February 2012

Nature or Drug Abuse?

There are significant structural changes in striatal and prefrontal brain regions of stimulant drugdependent individuals. However, it is not clear if these brain abnormalities predate drug-taking, rendering individuals vulnerable for the development of dependence, or if these changes are the effect of many years of drug use.

Ersche
et al.

(p.
601
; see the Perpective by

Volkow and Baler

) investigated brain abnormalities in both drug-dependent individuals and in their biological siblings who have never taken drugs of abuse and compared them with matched healthy volunteers. The brain abnormalities in the sibling pairs were associated with significant impairments in the regulation of behavior; an ability known to be compromised in drug dependence. Because these neural changes were observed in family members who do not take drugs, the changes are likely to represent neurological markers of vulnerability to addiction rather than consequences of chronic drug abuse.
Spin-Down of Radio Millisecond Pulsars at Genesis
Authors: Tauris Thomas M.
Published: February 2012

Probing Pulsar Rotation

Pulsars are strongly magnetized, rapidly rotating neutron stars. Those with periods of the order of milliseconds obtain their fast spin by accreting mass from a companion star in a binary system.
Tauris
(p.
561
) combined numerical stellar evolution calculations with a model of how accretion torques act on a neutron star. During the late accretion phase of millisecond pulsars, the termination stage of mass transfer results in a loss of more than 50% of their rotational energy. This effect may explain the observed pulsar spin distributions.
Ready, Steady, Compete
Authors: Villeval Marie Claire
Published: February 2012

Women's willingness to compete can be increased through appropriate affirmative action.
Celebrated Exoplanet Vanishes in a Cloud of Dust—Or Maybe Not
Authors: Bhattacharjee Yudhijit
Published: February 2012

Last week, Fomalhaut b, an exoplanet that once enjoyed celebrity status, faced an identity crisis after astronomers failed to spot it in a new round of observations.
China's Sequencing Powerhouse Comes of Age
Authors: Normile Dennis
Published: February 2012

With new sequencing centers in Europe and the United States, BGI hopes its growing clout will help deliver the benefits promised by genomics—and revenue to pay off a mounting debt.
Antigen Targeting to Major Histocompatibility Complex Class II with Streptococcal Mitogenic Exotoxin Z-2 M1, a Superantigen-Based Vaccine Carrier
Authors: Radcliff Fiona J. , Loh Jacelyn M. S. , Ha Birgit , Schuhbauer Diana , McCluskey James , Fraser John D.
Published: February 2012

Streptococcal mitogenic exotoxin Z-2 (SMEZ-2) is a streptococcal superantigen that primarily stimulates human T cells bearing Vβ8 and mouse T cells bearing Vβ11. Mutagenesis of T cell receptor (TCR)-binding residues (W75L, K182Q, D42C) produced a mutant called M1 that was >105-fold less active toward human peripheral blood lymphocytes and splenocytes from transgenic mice that express human CD4 and either human HLA-DR3-DQ2 or HLA-DR4-DQ8. Similarly, cytokine production in response to M1 in lymphocyte culture was rendered undetectable, and no change in the frequency of Vβ11-bearing T cells in mice receiving M1 was observed. M1 toxoid was tested as a potential vaccine conjugate. Vaccination with 1 to 10 μg M1 conjugated to ovalbumin (M1-ovalbumin) resulted in more rapid and quantitatively higher levels of anti-ovalbumin IgG, with endpoint titers being 1,000- to 10,000-fold greater than those in animals immunized with unconjugated ovalbumin. Substantially higher levels of anti-ovalbumin IgG were observed in mice transgenic for human major histocompatibility complex (MHC) class II. Substitution of M1 with an MHC class II binding mutant (DM) eliminated enhanced immunity, suggesting that M1 enhanced the delivery of antigen via MHC class II-positive antigen-presenting cells that predominate within lymphoid tissue. Immunization of animals with a conjugate consisting of M1 and ovalbumin peptide from positions 323 to 339 generated levels of anti-peptide IgG 100-fold higher than those in animals immunized with peptide alone. Coupling of a TCR-defective superantigen toxoid presents a new strategy for conjugate vaccines with the additional benefit of targeted delivery to MHC class II-bearing cells.
The Presence of Alpha Interferon at the Time of Infection Alters the Innate and Adaptive Immune Responses to Porcine Reproductive and Respiratory Syndrome Virus
Authors: Brockmeier Susan L. , Loving Crystal L. , Nelson Eric A. , Miller Laura C. , Nicholson Tracy L. , Register Karen B. , Grubman Marvin J. , Brough Douglas E. , Kehrli Marcus E.
Published: February 2012

Porcine reproductive and respiratory syndrome (PRRS) is one of the most devastating and costly diseases to the swine industry worldwide. Overall, the adaptive immune response to PRRS virus (PRRSV) is weak, which results in delayed elimination of virus from the host and inferior vaccine protection. PRRSV has been shown to induce a meager alpha interferon (IFN-α) response, and we hypothesized that elevated IFN-α levels early in infection would shorten the induction time and increase elements of the adaptive immune response. To test this, we measured both antibody and cell-mediated immunity in pigs after the administration of a nonreplicating human adenovirus type 5 vector expressing porcine IFN-α (Ad5–pIFN-α) at the time of PRRSV infection and compared the results to those for pigs infected with PRRSV alone. Viremia was delayed, and there was a decrease in viral load in the sera of pigs administered the Ad5–pIFN-α. Although seroconversion was slightly delayed in pigs receiving Ad5–pIFN-α, probably due to the early reduction in viral replication, little difference in the overall or neutralizing antibody response was seen. However, there was an increase in the number of virus-specific IFN-γ-secreting cells detected in the pigs receiving Ad5–pIFN-α, as well as an altered cytokine profile in the lung at 14 days postinfection, indicating that the presence of IFN-α at the time of infection can alter innate and adaptive immune responses to PRRSV.
Glutamate Dehydrogenase Is Highly Conserved among Clostridium difficile Ribotypes
Authors: Carman R. J. , Wickham K. N. , Chen L. , Lawrence A. M. , Boone J. H. , Wilkins T. D. , Kerkering T. M. , Lyerly D. M.
Published: February 2012

gluD
was highly conserved and glutamate dehydrogenase (GDH) was readily expressed
in vitro
by all 77
Clostridium difficile
ribotypes assayed. All ribotypes, including ARL 002, ARL 027, and ARL 106, were reactive in assays that detect
C. difficile
GDH.
Species Identification of Clinical Prevotella Isolates by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry
Authors: Wybo Ingrid , Soetens Oriane , De Bel Annelies , Echahidi Fedoua , Vancutsem Ellen , Vandoorslaer Kristof , Piérard Denis
Published: February 2012

The performance of matrix-assisted laser desorption–ionization time of flight mass spectrometry (MALDI-TOF MS) for species identification of
Prevotella
was evaluated and compared with 16S rRNA gene sequencing. Using a Bruker database, 62.7% of the 102 clinical isolates were identified to the species level and 73.5% to the genus level. Extension of the commercial database improved these figures to, respectively, 83.3% and 89.2%. MALDI-TOF MS identification of
Prevotella
is reliable but needs a more extensive database.
Evidence Implicating Thamnostylum lucknowense as an Etiological Agent of Rhino-Orbital Mucormycosis
Authors: Xess Immaculata , Mohapatra Sarita , Shivaprakash M. R. , Chakrabarti Arunaloke , Benny Gerald L. , O'Donnell Kerry , Padhye Arvind A.
Published: February 2012

In this report, we present a case of rhino-orbital mucormycosis in a 57-year-old female with poorly controlled diabetes mellitus. The only mold cultured at 25°C, 37°C, and 40°C from a specimen of the nasal crust was identified phenotypically and independently using nuclear ribosomal DNA sequence data as
Thamnostylum lucknowense
. To our knowledge, this report presents the first data implicating this mucoraceous fungus as a mycotic agent of human infection.
Mouse Norovirus 1 Utilizes the Cytoskeleton Network To Establish Localization of the Replication Complex Proximal to the Microtubule Organizing Center
Authors: Hyde Jennifer L. , Gillespie Leah K. , Mackenzie Jason M.
Published: February 2012

Human noroviruses (family
Caliciviridae
) are the leading cause of nonbacterial gastroenteritis worldwide. Although Human noroviruses are significant enteric pathogens, there exists no reliable vaccine or therapy to treat infected individuals. To date, attempts to cultivate Human noroviruses within the laboratory have met with little success; however, the related murine norovirus mouse norovirus 1 (MNV-1) has provided an ideal model system to study norovirus replication due to the ease with which the virus is cultivated and the ability to infect a small animal model with this virus. Previously we have identified the association between MNV-1 and components of the host secretory pathway and proposed a role for the viral open reading frame 1 proteins in the replication cycle. Here we describe for the first time a role for cytoskeletal components in early MNV-1 replication events. We show that the MNV-1 utilizes microtubules to position the replication complex adjacent to the microtubule organizing center. Chemical disruption of the microtubule network disperses the sites of MNV-1 replication throughout the cell and impairs production of viral protein and infectious virus. Furthermore, we demonstrate the ability of MNV-1 to redistribute acetylated tubulin to the replication complex and that this association is potentially mediated via the MNV-1 major structural protein, VP1. Transient expression of MNV-1 VP1 exhibited extensive colocalization with both α-tubulin and acetylated tubulin and was observed to alter the distribution of acetylated tubulin in transfected cells. This study highlights the role of the cytoskeleton in early virus replication events and demonstrates the importance of this interaction in establishing the intracellular location of MNV-1 replication complexes.
The Human Immunodeficiency Virus Type 1 Nef and Vpu Proteins Downregulate the Natural Killer Cell-Activating Ligand PVR
Authors: Matusali Giulia , Potestà Marina , Santoni Angela , Cerboni Cristina , Doria Margherita
Published: February 2012

The human immunodeficiency virus type 1 (HIV-1) evades the immune responses of natural killer (NK) cells through mechanisms that have been partially deciphered. Here we show that in HIV-1-infected T lymphocytes, the early viral Nef protein downmodulates PVR (CD155, Necl-5), a ligand for the activating receptor DNAM-1 (CD226) expressed by all NK cells, CD8
+
T cells, and other cell types. This novel Nef activity is conserved by Nef proteins of laboratory HIV-1 strains (NL4-3, SF2) and of a patient-derived virus, but it is not maintained by HIV-2. Nef uses the same motifs to downregulate PVR and HLA-I molecules, likely by the same mechanisms. Indeed, as previously demonstrated for HLA-I, Nef reduces the total amounts of cell-associated PVR. Optimal downregulation of cell surface PVR by Nef also requires the presence of the late viral factor Vpu. In line with PVR reduction, the NK cell-mediated lysis of T cells infected by a wild-type but not Nef-deficient virus is virtually abrogated upon blocking of both DNAM-1 and another activating receptor, NKG2D, previously shown to mediate killing of HIV-infected cells. Together, these data demonstrate that the PVR downmodulation by Nef and Vpu is a strategy evolved by HIV-1 to prevent NK cell-mediated lysis of infected cells. The PVR downregulation reported here has the potential to affect the immune responses of other DNAM-1-positive cells besides NK cells and to alter multiple PVR-mediated cellular processes, such as adhesion and migration, and may thus greatly influence HIV-1 pathogenesis.
Human Immunodeficiency Virus Type 1 Capsid Mutation N74D Alters Cyclophilin A Dependence and Impairs Macrophage Infection
Authors: Ambrose Zandrea , Lee KyeongEun , Ndjomou Jean , Xu Hongzhan , Oztop Ilker , Matous James , Takemura Taichiro , Unutmaz Derya , Engelman Alan , Hughes Stephen H. , KewalRamani Vineet N.
Published: February 2012

The antiviral factor CPSF6-358 interferes with the nuclear entry of human immunodeficiency virus type 1 (HIV-1). HIV-1 acquires resistance to CPSF6-358 through the N74D mutation of the capsid (CA), which alters its nuclear entry pathway. Here we show that compared to wild-type (WT) HIV-1, N74D HIV-1 is more sensitive to cyclosporine, has increased sensitivity to nevirapine, and is impaired in macrophage infection prior to reverse transcription. These phenotypes suggest a difference in the N74D reverse transcription complex that manifests early after infection and prior to interaction with the nuclear pore. Overall, our data indicate that N74D HIV-1 replication in transformed cells requires cyclophilin A but is dependent on other interactions in macrophages.
Passively Transmitted gp41 Antibodies in Babies Born from HIV-1 Subtype C-Seropositive Women: Correlation between Fine Specificity and Protection
Authors: Diomede L. , Nyoka S. , Pastori C. , Scotti L. , Zambon A. , Sherman G. , Gray C. M. , Sarzotti-Kelsoe M. , Lopalco L.
Published: February 2012

HIV-exposed, uninfected (EUN) babies born to HIV-infected mothers are examples of natural resistance to HIV infection. In this study, we evaluated the titer and neutralizing potential of gp41-specific maternal antibodies and their correlation with HIV transmission in HIV-infected mother-child pairs. Specific gp41-binding and -neutralizing antibodies were determined in a cohort of 74 first-time mother-child pairs, of whom 40 mothers were infected with HIV subtype C. Within the infected mother cohort, 16 babies were born infected and 24 were PCR negative and uninfected at birth (i.e., exposed but uninfected). Thirty-four HIV-uninfected and HIV-unexposed mother-child pairs were included as controls. All HIV-positive mothers and their newborns showed high IgG titers to linear epitopes within the HR1 region and to the membrane-proximal (MPER) domain of gp41; most sera also recognized the disulfide loop immunodominant epitope (IDE). Antibody titers to the gp41 epitopes were significantly lower in nontransmitting mothers (
P
< 0.01) and in the EUN babies (
P
< 0.005) than in HIV-positive mother-child pairs. Three domains of gp41, HR1, IDE, and MPER, elicited antibodies that were effectively transmitted to EUN babies. Moreover, in EUN babies, epitopes overlapping the 2F5 epitope (ELDKWAS), but not the 4E10 epitope, were neutralization targets in two out of four viruses tested. Our findings highlight important epitopes in gp41 that appear to be associated with exposure without infection and would be important to consider for vaccine design.
HIV-1 Virus-Like Particles Bearing Pure Env Trimers Expose Neutralizing Epitopes but Occlude Nonneutralizing Epitopes
Authors: Tong Tommy , Crooks Ema T. , Osawa Keiko , Binley James M.
Published: February 2012

Hypothetically, since native HIV-1 Env trimers are exclusively recognized by neutralizing antibodies, they might induce the neutralizing antibodies in a vaccine setting. This idea has not been evaluated due to the difficulty of separating trimers from nonfunctional Env (uncleaved gp160 and gp41 stumps). The latter are immunodominant and induce nonneutralizing antibodies. We previously showed that nonfunctional Env can be selectively cleared from virus-like particle (VLP) surfaces by enzyme digests (E. T. Crooks, T. Tong
,
K. Osawa, and J. M. Binley, J.Virol. 85:5825, 2011). Here, we investigated the effects of these digests on the antigenicity of VLPs and their sensitivity to neutralization. Before digestion, WT VLPs (bearing wild-type Env) and UNC VLPs (bearing uncleaved gp160) were recognized by various Env-specific monoclonal antibodies (MAbs), irrespective of their neutralizing activity, a result which is consistent with the presence of nonfunctional Env. After digestion, only neutralizing MAbs recognized WT VLPs, consistent with selective removal of nonfunctional Env (i.e., “trimer VLPs”). Digests eliminated the binding of all MAbs to UNC VLPs, again consistent with removal of nonfunctional Env. An exception was MAb 2F5, which weakly bound to digested UNC VLPs and bald VLPs (bearing no Env), perhaps due to lipid cross-reactivity. Trimer VLPs were infectious, and their neutralization sensitivity was largely comparable to that of undigested WT VLPs. However, they were ∼100-fold more sensitive to the MAbs 4E10 and Z13e1, suggesting increased exposure of the gp41 base. Importantly, a scatterplot analysis revealed a strong correlation between MAb binding and neutralization of trimer VLPs. This suggests that trimer VLPs bear essentially pure native trimer that should allow its unfettered evaluation in a vaccine setting.
Virus-Activated Interferon Regulatory Factor 7 Upregulates Expression of the Interferon-Regulated
BST2
Gene Independently of Interferon Signaling
Authors: Bego Mariana G. , Mercier Johanne , Cohen Éric A.
Published: February 2012

BST-2/tetherin is an interferon (IFN)-inducible host restriction factor that inhibits the release of many enveloped viruses and functions as a negative-feedback regulator of IFN production by plasmacytoid dendritic cells. Currently, mechanisms underlying
BST2
transcriptional regulation by type I IFN remain largely unknown. Here, we demonstrate that the
BST2
promoter is a secondary target of the IFN cascade and show that a single IRF binding site is sufficient to render this promoter responsive to IFN-α. Interestingly, expression of IRF-1 or virus-activated forms of IRF-3 and IRF-7 stimulated the
BST2
promoter even under conditions where type I IFN signaling was inhibited. Indeed, vesicular stomatitis virus could directly upregulate BST-2 during infection of mouse embryonic fibroblasts through a process that required IRF-7 but was independent from the type I IFN cascade; however, in order to achieve optimal BST-2 induction, the type I IFN cascade needed to be engaged through activation of IRF-3. Furthermore, using human peripheral blood mononuclear cells, we show that BST-2 upregulation is part of an early intrinsic immune response since TLR8 and TLR3 agonists, known to trigger pathways that mediate activation of IRF proteins, could upregulate BST-2 prior to engagement of the type I IFN pathway. Collectively, our findings reveal that
BST2
is activated by the same signals that trigger type I IFN production, outlining a regulatory mechanism ensuring that production of type I IFN and expression of a host restriction factor involved in the IFN negative-feedback loop are closely coordinated.
Two Distinct Broadly Neutralizing Antibody Specificities of Different Clonal Lineages in a Single HIV-1-Infected Donor: Implications for Vaccine Design
Authors: Bonsignori Mattia , Montefiori David C. , Wu Xueling , Chen Xi , Hwang Kwan-Ki , Tsao Chun-Yen , Kozink Daniel M. , Parks Robert J. , Tomaras Georgia D. , Crump John A. , Kapiga Saidi H. , Sam Noel E. , Kwong Peter D. , Kepler Thomas B. , Liao Hua-Xin , Mascola John R. , Haynes Barton F.
Published: February 2012

Plasma from a small subset of subjects chronically infected with HIV-1 shows remarkable magnitude and breadth of neutralizing activity. From one of these individuals (CH0219), we isolated two broadly neutralizing antibodies (bnAbs), CH01 and VRC-CH31, from two clonal lineages of memory B cells with distinct specificities (variable loop 1 and 2 [V1V2] conformational specificity and CD4-binding site specificity, respectively) that recapitulate 95% of CH0219 serum neutralization breadth. These data provide proof of concept for an HIV-1 vaccine that aims to elicit bnAbs of multiple specificities.
Cheese can reduce indexes that estimate fatty acid desaturation. Results from the Oslo Health Study and from experiments with human hepatoma cells
Authors: Høstmark Arne T. , Lunde Marianne S.H.
Published: February 2012

Previously, cheese intake was shown to be inversely related to serum triglycerides, raising the possibility that cheese might inhibit triglyceride synthesis, which is governed by fatty acid desaturases. Therefore, analyses were done to study whether cheese intake was associated with indexes that reflect fatty acid desaturation in 121 healthy ethnic Norwegians aged 40–45 years, a subsample from the Oslo Health Study (N = 18 777). Experiments with human hepatoma cells (HepG2) were done to clarify whether cheese might have a causal effect on desaturases. Fatty acid distribution in lipids of human sera and HepG2 cells was determined by gas chromatography. Δ9-Desaturase was estimated by the (16:1,n-7)/(16:0) and (18:1,n-9)/(18:0) ratios, abbreviated ds9_1 and ds9_2, and Δ5-desaturase (ds5) by the (20:4,n-6)/(18:2,n-6) ratio. Correlation, ANOVA, and multiple linear regression models were used to study associations. Oslo Health Study: Subjects with cheese intake >4–6 times per week had 33% lower ds9_1 and 16% lower ds5 than subjects with intake ≤ 4–6 times per week. The cheese intake vs. ds5 association prevailed when adjusting for sex, time since last meal, fatty fish, vegetables, fruit–berries, fruit juice, cod liver oil, coffee, alcohol, body mass index, physical activity, length of education, and smoking. HepG2 cells: An ethanol extract of Jarlsberg cheese lowered the desaturase indexes. Inhibition of ds9_1 increased with increasing amount cheese extract added. Thus, cheese may contain inhibitors of desaturases, thereby providing an explanation for the previously reported negative association between cheese intake and triglycerides.
Altered plasma and erythrocyte phospholipid fatty acid profile in elite female water polo and football players
Authors: Arsić Aleksandra , Vučić Vesna , Tepšić Jasna , Mazić Sanja , Djelić Marina , Glibetić Marija
Published: February 2012

The impact of chronic, intense exercise, such as in elite athletes, on phospholipids fatty acids (FA) composition has not been studied in women so far. This study aimed to investigate FA profiles in plasma and erythrocytes phospholipids in elite female water polo (N = 15) and football (N = 19) players in comparison with sedentary women. In spite of similar dietary patterns, as assessed by a food frequency questionnaire, plasma FA profile in the football players showed significantly higher proportions of stearic acid, oleic acid, and monounsaturated FA (MUFA), and significantly lower proportions of total and n-6 polyunsaturated FA (PUFA) than in the water polo and control group. The water polo players had higher percentages of palmitoleic acid and arachidonic acid than the control subjects. Erythrocyte FA profile differed among groups. We found significantly higher proportion of oleic acid and MUFA in the football group than in the controls, and decreased stearic acid and elevated palmitic and palmitoleic acid in the water polo players than in the other 2 groups. Both groups of athletes had significantly lower percentages of n-6 dihomo-γ-linolenic acid, n-6 PUFA, and total PUFA compared with the controls. The estimated activities of elongase and desaturases in erythrocytes were also altered in the athletes. Our results indicate that long-term, intense physical training significantly affects FA status of plasma and erythrocyte phospholipids in women. The observed differences between the water polo and the football players suggest that the type of regular training may contribute to the altered metabolism of FA, although possible genetic differences among the 3 study groups cannot be ruled out.
High-power resistance exercise induces MAPK phosphorylation in weightlifting trained men
Authors: Galpin Andrew J. , Fry Andrew C. , Chiu Loren Z.F. , Thomason Donald B. , Schilling Brian K.
Published: February 2012

Power is critical to muscle performance, specifically in athletic populations. Mitogen-activated protein kinase (MAPK) pathways (extracellular signal-regulated protein kinase (ERK 1/2), p38, and c-Jun NH2-terminal kinase (JNK)) are intracellular signal transduction mechanisms that partially regulate exercise-induced skeletal muscle alterations. These pathways are highly responsive to exercise, but their reaction to high power, multi-joint resistance exercise is yet to be examined. Nine weightlifting-trained men performed 15 sets of three repetitions of a dynamic clean pull exercise at 85% of their one repetition maximum. Vastus lateralis biopsies were obtained prior to (pre) and after the 8th (mid) and 15th set (post) of exercise. Three subjects returned to serve as non-exercising controls for a similar sequence of biopsies (CON). The ratio of phosphorylated MAPK to total MAPK increased significantly for p38 (3.0 fold, p < 0.05) and JNK (2.4 fold, p < 0.05) by the mid biopsy. ERK 1/2 phosphorylation followed a similar trend (2.3 fold) (p = 0.052). The ratio of phosphorylation to total MAPK did not differ from mid to post biopsy. None of the pathways were phosphorylated above resting in the CON condition (p > 0.05), and thus the biopsy procedure itself did not account for the entire increase in MAPK phosphorylation during EX. These data indicate MAPK pathways are activated early and remain elevated throughout the duration of high power resistance exercise. These findings help describe the mechanisms partially responsible for chronic adaptations in response to high intensity, high power resistance training in humans.
A short bout of stair climbing–descending exercise attenuates postprandial hyperglycemia in middle-aged males with impaired glucose tolerance
Authors: Takaishi Tetsuo , Imaeda Kenro , Tanaka Tsutomu , Moritani Toshio , Hayashi Tatsuya
Published: February 2012

Exercise is a useful modality to ameliorate postprandial hyperglycemia. Here we show that a short bout (∼6 min) of stair climbing–descending exercise (STAIR) starting at 90 min after meal accelerates the decrease in blood glucose concentrations in middle-aged sedentary men with impaired glucose tolerance, although STAIR is easy to perform and keeps the exercise intensity at a moderate level.
Use of vitamin and mineral supplements in long-term care home residents
Authors: Viveky Navita , Toffelmire Lynda , Thorpe Lilian , Billinsky Jennifer , Alcorn Jane , Hadjistavropoulos Thomas , Whiting Susan J.
Published: February 2012

Vitamin–mineral supplementation may offer older adults health and cognition-related benefits but overuse may contribute to polypharmacy. We examined the prevalence of supplement usage in long-term care facility (LTC) residents (≥65 years of age). As cognition may be affected by nutrition, we also examined use in those with diagnosis of dementia and those with no dementia diagnosis. The prevalence of supplement usage and overall “pill count” from pharmaceutical use was assessed in 189 LTC residents and a subsample of 56 older adults with dementia diagnosis, respectively. Participants were residing in an LTC facility of a mid-size metropolitan area during 2009. The average use of supplements was 1.0 per day for all residents, with 35% taking vitamin D supplements, 20% multivitamins, and 26% calcium. Supplement use was similar (p ≥ 0.05) for those with dementia diagnosis (53%, average 2.0 per day) and for those without such diagnosis (45%, average 2.2 per day). Usage ranged between 1–6 supplements per day. In both of these groups, ∼73% of users were taking vitamin D. The number of prescribed medications ranged from 4 to 24 (average 10.2) in a subsample of residents whose supplement intake was 0 to 6 (average 2). These findings suggest an overall low rate of supplement use, with no significant differences (p ≥ 0.05) in use between residents with and without dementia diagnosis. However, some residents were at risk for supplement overuse.
Type 1 diabetes impairs vitamin B6 metabolism at an early stage of women’s adulthood
Authors: Massé Priscilla G. , Boudreau Jaclyn , Tranchant Carole C. , Ouellette Rodney , Ericson Karen L.
Published: February 2012

Vitamin B6 (pyridoxine) metabolism in diabetes has never been investigated except for a few reports on plasma pyridoxal 5′-phosphate (PLP). These studies indicated that this most active (coenzyme) vitamer can be reduced. The present clinical investigation aimed to measure all vitamers in blood and urine by high performance liquid chromatography as well as important related factors, in women during active reproductive years. Thirty-two insulin-treated type 1 diabetic (T1D) patients, without renal complication, and 27 well-matched healthy controls, aged 30 to 40 years old, were recruited using rigorous criteria. Both groups had normal hemoglobin and serum albumin levels. Plasma PLP and pyridoxal (PL) did not differ significantly in the T1D group but alkaline phosphatase (ALP) activity was greater (p < 0.01). This produced a shift in plasma PLP-PL profile, as evidenced by a lower plasma PLP/PL ratio (p < 0.05). Enhanced ALP activity meant more PLP being dephosphorylated to PL (the membrane transfer form), with more ending up in erythrocytes to be rephosphorylated in its active form, as suggested by the significant positive correlation (p < 0.001) between plasma PL and erythrocyte PLP. More PL into blood circulation also means more oxidation of this vitamer to 4′-pyridoxic acid in kidneys, as confirmed by the positive correlation between plasma PL and urinary 4′-pyridoxic acid (p < 0.001). The positive correlation (p < 0.001) between ALP activity and glycosylated hemoglobin indicated a direct effect of the disease. The T1D-induced alteration in vitamin B6 metabolism, consecutive to enhanced ALP activity, may put patients at greater risk of vitamin B6 deficiency and diabetic complications.
SCALING LAW OF SUPERFLUID–INSULATOR TRANSITION IN THE 1D BOSE–HUBBARD MODEL
Authors: GU SHI-JIAN , CAO JUNPENG , CHEN SHU , LIN HAI-QING
Published: February 2012

The finite size scaling behavior of superfluid–insulator transition in the one-dimensional Bose–Hubbard model is studied. It is shown that the superfluid density of the system with finite size has a maximum at a certain interaction Um and the derivative of superfluid density has a minimum at a certain interaction Ud. The critical point Uc can be quantified by the scaling analysis of either Um or Ud. The transition point Um tends to the critical point Uc from the region of U < Uc, while the Ud tends to the Uc from the region of U > Uc. The transition points Um and Ud satisfy different finite size scaling laws and have the different critical exponents. The divergence speed of the superfluid density is much smaller than that of its derivative at the critical point.