bluuebunny/crossref_metadata_2025 huggingface dataset:
Photodynamic Imaging of a Rat Pancreatic Cancer with Pheophorbide a
Authors: Keller P. , Sowinska M. , Tassetti V. , Heisel F. , Hajri A. , Evrard S. , Miehe J. A. , Marescaux J. , Aprahamian M.
Published: January 2008

Laser‐induced fluorescence of pheophorbide a (Ph‐a) was used for in vitro photodynamic imaging (PDI) of a rat pancreatic acinar tumor. A 400 nm excitation induced a 470 nm autofluorescence and a 678 nm dye fluorescence in tumors and their surrounding pancreas 24 h after a 9 mg kg−1 body weight Ph‐a intravenous administration. With lower intensities in these blood‐rich tumors than in pancreas, Ph‐a fluorescence signals are unable to provide tumor images. A dimensionless function (the ratio of Ph‐a fluorescence by autofluorescence, called Rt for the tumor and Rp for the pancreas) was used for fluorescence contrast calculation (C = Rt/Rp) between six tumors and their paired pancreas. Among five available laser excitation wavelengths, only the 355 nm excitation gave a distinctive contrast (C = 1.5). The PDI of six intrapancreatic tumors and their intraperitoneal metastasis and of two control normal pancreas was thus performed ex vivo using a 355 nm excitation source delivered by a tripled Nd: YAG laser and a charged‐coupled device camera. Fluorescence images were recorded at 680 nm (dye), 640 nm (background) and 470 nm (autofluorescence) through three corresponding 10 nm width bandpass filters. Computed division for each pixel of Ph‐a fluorescence values by autofluorescence generated false color image. In this way, contrasted tumor images were obtained. But in five out of six animals false‐positive images were present due to an autofluorescence decrease in some normal pancreatic areas. A 470 nm autofluorescence imaging on the same tumors gave in all cases false‐positive image and false‐negative in half of the cases. These observations suggest that autofluorescence alone is unable to achieve accurate PDI of pancreatic carcinoma and that using Ph‐a as a PDI dye needs strong improvements.
Ultraviolet Spectral Energy Differences Affect the Ability of Sunscreen Lotions to Prevent Ultraviolet‐Radiation‐Induced Immunosuppression*
Authors: Robertst Lee K. , Beasley Donathan G. , Learn Douglas B. , Giddens Lori D. , Beard John , StanfieW Joseph W.
Published: January 2008

Acute exposure to UV radiation causes immunosuppression of contact hypersensitivity (CH) responses. Past studies conducted with unfiltered sunlamps emitting nonsolar spectrum UV power (wavelengths below 295 nm) or using excessive UV doses have suggested sunscreens may not prevent UV‐induced immunosuppression in mice. This study was thus designed to evaluate critically the effects of different UV energy spectra on the immune protection capacity of sunscreen lotions. Minimum immune suppression doses (MISD), i.e. the lowest UV dose to cause~50% suppression of the CH response to dinitrofluorobenzene in C3H mice, were established for three artificial UV sources. The MISD for each UV source was 0.25 kJ/m2 for unfiltered FS20 sunlamps (FS), 0.90 kJ/m2 for Kodacel‐filtered FS20 sunlamps (KFS), which do not emit UV power at wavelengths <290 nm, and 1.35 kJ/m2 for a 1000 W filtered xenon arc lamp solar simulator. Using MISD as baseline, sunscreens with labeled sun protection factors (SPF) of 4, 8, 15 and 30 were tested with each UV source to establish their relative immune protection factors. The immune protection factor of each sunscreen exceeded its labeled SPF in tests conducted with the solar simulator, which has a UV power spectrum (295–400 nm) similar to that of sunlight. Conversely, sunscreen immune protection factors were significantly less than the labeled SPF in tests conducted with FS and KFS. Comparison of the immunosuppression effectiveness spectra showed that relatively small amounts of nonsolar spectrum UV energy, i.e. UVC (200–290 nm) and/or shorter wavelength UVB (between 290 and 295 nm), produced by FS and KFS contributes significantly to the induction of immunosuppression. For example, 36.3% and 3.5% of the total immunosuppressive UV energy from FS and KFS, respectively, lies below 295 nm. Sunscreen absorption spectra showed that transmission of immunosuppressive UV energy below 295 nm for FS was at least eight‐fold higher than that for KFS. Compared to the solar simulator UV spectrum the transmission of nonsolar immunosuppressive UV energy through sunscreens was >15‐fold higher for FS and ≥1.5‐fold higher for KFS. These data demonstrate that relevant evaluations of sunscreen immune protection can only be obtained when tests are conducted with UV sources that produce UV power spectra similar to that of sunlight and UV doses are employed that are based on established MISD.
Distribution and Excretion of Radiolabeled Temoporfin in a Murine Tumor Model
Authors: Whelpton Robin , Michael‐Titus Adina T. , Jamdar Ravi P. , Abdillahi Kaltun , Grahn Michael F.
Published: January 2008

The biodistribution and excretion of temoporfin (tetra[m‐hydroxyphenyl]chlorin, m‐THPC), a recently developed photosensitizer, was investigated in BALB/c mice. [14C]temoporfin was administered intravenously (0.73 μmol/kg) to tumor‐free mice or to mice implanted with the Colo 26 colorectal carcinoma. Blood, tissue and fecal samples were collected for 35 days and 10 days postdose from tumor‐free mice and tumor‐bearing mice, respectively. Blood concentrations fell rapidly such that at later time points they were indistinguishable from background counts. Tumor concentrations rose to a peak of 0.34 μg temoporfin equivalents/mL at 2 days and then declined in parallel (log plot) with the blood concentrations. Tumor : tissue ratios at 2 days for skin, adipose tissue and skeletal muscle underlying the tumor were 1.5, 2.3 and 3.8, respectively. By 4 days the corresponding values were 1.6, 3.4 and 4.0. Nearly 40% of the administered radioactivity was excreted in the feces in the first 24 h and more than 80% had been excreted by 20 days. Less than 0.2 % of the dose was recovered from the urine. An elimination half‐life of 10–12 days was calculated from the excretion data.
On the Roles of Urocanic Acid in Photoimmunosuppression: Attempted Photorepair of Urocanic Acid‐DNA Cyclobutane Adducts with DNA Photolyase
Authors: Terrian Deborah L. , Kuhll C. Nicole , Tessman Irwin , Morrison Harry
Published: January 2008

It has been reported that UV‐induced immunosuppres‐sion can be reversed by photoreactivation or exposure to T4 endonuclease V, two treatments that can repair cyclobutane pyrimidine dimers. These observations, together with the known role of urocanic acid (UA) in UV‐induced immune suppression, prompted us to study the ability of DNA photolyase to repair UA‐DNA cyclobutane photoadducts in single‐stranded calf thymus DNA. We did not detect any release of UA, with a sensitivity implying that photolyase is at least 2900 times less active toward UA‐DNA adducts than toward cis‐syn thyminethymine dimers. This indicates that any reversal of photoimmunosuppression by photoreactivation cannot significantly involve cleavage of UA‐DNA cyclobutane adducts.
Effect of Additives on the Durability and Properties of Antireflective Films for Solar Glass Covers
Authors: Vicente Gema San , Bayón Rocío , Morales Angel
Published: January 2008

Generally, single layer antireflective (AR) coatings are based on SiO2 for which the low refractive index is achieved by increasing the porosity of the films. On the other hand, the increase of porosity on any material results in a decrease of its mechanical properties. In addition to increasing the solar transmittance, it is equally important that the AR film is long-term stable for its application in solar collectors. In this sense, the objective of our work has been to develop a film that exhibits good AR properties and physical durability as well. In the present study, sol-gel silica films have been deposited on borosilicate glass. The effect of adding some organic compounds to the precursor solution in the properties of the films has been studied. Moreover, accelerated weathering tests have been performed in order to investigate the outdoor durability. A value of solar transmittance as high as 0.974 has been obtained by using a porosity promoter additive. However, the durability tests have shown the necessity of incorporating a hydrophobic additive to the precursor solutions in order to avoid the degradation of the optical properties of the films. 1.5% decrease in solar transmittance is observed after 1900h in the weathering chamber for films prepared with methyltriethoxysilane.
Solar Photocatalysis for the Elimination of Trichloroethylene in the Gas Phase
Authors: Coronado Juan M. , Sánchez Benigno , Portela Raquel , Suárez Silvia
Published: January 2008

In the present work, we have studied the photocatalytic degradation of trichloroethylene (TCE) under sunlight illumination with the aim of determining the feasibility of using this technology for gas purification. For these experiments, a continuous flow reactor was employed. This system is basically constituted by a Pyrex glass tube located in the focus of a compound parabolic collector made of anodized aluminum. Raschig rings of borosilicate glass coated with TiO2 and randomly packed within the reactor tube were used as photocatalyts. Results obtained using sunlight illumination indicate that this continuous flow solar reactor can achieve complete TCE degradation. Experimentally, it is found that for moderate conversions, the TCE degradation rate increases linearly with solar irradiance, but a dependence of lower order is observed when removal of the pollutant is almost complete. On the other hand, photonic efficiency decreases linearly with solar irradiance, and it is higher when the molar flow fed to the photoreactor increases. In contrast, the selectivity toward the different partial degradation products (dichloroacetyl chloride, COCl2, etc.) is basically insensitive to solar irradiance.
Boron Hydrolysis at Moderate Temperatures: First Step to Solar Fuel Cycle for Transportation
Authors: Vishnevetsky Irina , Epstein Michael , Abu-Hamed Tareq , Karni Jacob
Published: January 2008

Boron hydrolysis reaction can be used for onboard production of hydrogen. Boron is a promising candidate because of its low molecular weight and relatively high valence. The oxide product from this process can be reduced and the boron can be recovered using known technologies, e.g., chemically with magnesium or via electrolysis. In both routes solar energy can play a major role. In the case of magnesium, an intermediate product, magnesium oxide, is formed, and its reduction back to magnesium can exploit solar energy. The boron hydrolysis process at moderate reactor temperature up to 650°C, potentially suitable for use in vehicles, has not been sufficiently studied so far. This paper addresses the operational requirements using an experimental setup for investigating the hydrolysis reaction of metal powders exposed to steam containing atmosphere. The output hydrogen is measured as a function of temperature in reaction zone, steam partial pressure, and the different steam to metal ratio. Test results obtained during the hydrolysis of amorphous boron powder in batch experiments (with 0.1–2g of boron, water mass flow rate of 0.1–1g∕min, carrier gas flow rate of 100cm3∕min at total atmospheric pressure with steam partial pressure of 0.55–0.95bar abs) indicate that the reaction occurs in two different stages, depending on the temperature. A slow reaction starts at about 300°C and hydrogen output increases with reactor temperature and steam partial pressure. The fast stage starts as the reactor temperature approaches 500°C. At this temperature, the reaction develops vigorously due to higher reaction rate and its strong exothermic nature. The fast stage is self-restrained when 50–60% of the loaded boron is reacted and 1.5–1.8 SPT L H2 per 1g of boron is produced. Raising the temperature before the steam flow starts during the preheating period above 500°C increases the hydrogen yield at the fast stage. Then, the reaction continues for a long time at slow rate until the hydrogen release is terminated. The duration of the fast step decreases sharply with the increase of the steam to boron ratio.
The Limits of Counting: Numerical Cognition Between Evolution and Culture
Authors: Beller Sieghard , Bender Andrea
Published: January 2008

Number words that, in principle, allow all kinds of objects to be counted ad infinitum are one basic requirement for complex numerical cognition. Accordingly, short or object-specific counting sequences in a language are often regarded as earlier steps in the evolution from premathematical conceptions to greater abstraction. We present some instances from Melanesia and Polynesia, whose short or object-specific sequences originated from the same extensive and abstract sequence. Furthermore, the object-specific sequences can be shown to be cognitively advantageous for calculations without notation because they use larger counting units, thereby abbreviating higher numbers, enhancing the counting process, and extending the limits of counting. These results expand our knowledge both regarding numerical cognition and regarding the evolution of numeration systems.
Isotopic Evidence for Glaciation During the Cretaceous Supergreenhouse
Authors: Bornemann André , Norris Richard D. , Friedrich Oliver , Beckmann Britta , Schouten Stefan , Damsté Jaap S. Sinninghe , Vogel Jennifer , Hofmann Peter , Wagner Thomas
Published: January 2008

The Turonian (93.5 to 89.3 million years ago) was one of the warmest periods of the Phanerozoic eon, with tropical sea surface temperatures over 35°C. High-amplitude sea-level changes and positive δ
18
O excursions in marine limestones suggest that glaciation events may have punctuated this episode of extreme warmth. New δ
18
O data from the tropical Atlantic show synchronous shifts ∼91.2 million years ago for both the surface and deep ocean that are consistent with an approximately 200,000-year period of glaciation, with ice sheets of about half the size of the modern Antarctic ice cap. Even the prevailing supergreenhouse climate was not a barrier to the formation of large ice sheets, calling into question the common assumption that the poles were always ice-free during past periods of intense global warming.
Self-Assembled Water-Soluble Nucleic Acid Probe Tiles for Label-Free RNA Hybridization Assays
Authors: Ke Yonggang , Lindsay Stuart , Chang Yung , Liu Yan , Yan Hao
Published: January 2008

The DNA origami method, in which long, single-stranded DNA segments are folded into shapes by short staple segments, was used to create nucleic acid probe tiles that are molecular analogs of macroscopic DNA chips. One hundred trillion probe tiles were fabricated in one step and bear pairs of 20-nucleotide-long single-stranded DNA segments that act as probe sequences. These tiles can hybridize to their targets in solution and, after adsorption onto mica surfaces, can be examined by atomic force microscopy in order to quantify binding events, because the probe segments greatly increase in stiffness upon hybridization. The nucleic acid probe tiles have been used to study position-dependent hybridization on the nanoscale and have also been used for label-free detection of RNA.
Breakdown of an Ant-Plant Mutualism Follows the Loss of Large Herbivores from an African Savanna
Authors: Palmer Todd M. , Stanton Maureen L. , Young Truman P. , Goheen Jacob R. , Pringle Robert M. , Karban Richard
Published: January 2008

Mutualisms are key components of biodiversity and ecosystem function, yet the forces maintaining them are poorly understood. We investigated the effects of removing large mammals on an ant-
Acacia
mutualism in an African savanna. Ten years of large-herbivore exclusion reduced the nectar and housing provided by plants to ants, increasing antagonistic behavior by a mutualistic ant associate and shifting competitive dominance within the plant-ant community from this nectar-dependent mutualist to an antagonistic species that does not depend on plant rewards. Trees occupied by this antagonist suffered increased attack by stem-boring beetles, grew more slowly, and experienced doubled mortality relative to trees occupied by the mutualistic ant. These results show that large mammals maintain cooperation within a widespread symbiosis and suggest complex cascading effects of megafaunal extinction.
Species-Specific Antibody Responses to the Recombinant 53-Kilodalton Excretory and Secretory Proteins in Mice Infected withTrichinellaspp
Authors: Nagano Isao , Wu Zhiliang , Takahashi Yuzo
Published: January 2008

The 53-kDa proteins in larval excretory and secretory (E-S) products were expressed from fiveTrichinellaspecies (T. spiralis,T. britovi,T. nativa,T. pseudospiralis, andT. papuae), using theEscherichia coliexpression system, and the antibody responses to the 53-kDa recombinant proteins in mice infected withTrichinellaspp. were analyzed by Western blotting. The 53-kDa protein is conserved among the fiveTrichinellaspecies, with >60% similarity in amino acid sequences. The 53-kDa recombinant proteins ofT. spiralisandT. pseudospiralisreacted to sera from mice infected withT. spiralisandT. pseudospiralisat 8 days postinfection (p.i.), respectively. An antibody against the 53-kDa recombinant protein ofT. spiralisrecognized the 53-kDa protein in the crude extracts from adult worms and 30-day p.i. muscle larvae and E-S products from muscle larvae ofT. spiralisbut did not recognize any proteins fromT. pseudospiralis. The sera from the mice infected withT. spiralisstrongly reacted with the 53-kDa recombinant protein ofT. spiralisbut did not react with the 53-kDa recombinant proteins ofT. britovi,T. nativa,T. pseudospiralis, andT. papuae. Similarly, the sera from mice infected withT. britovi,T. nativa,T. pseudospiralis, orT. papuaestrongly reacted with the 53-kDa recombinant proteins ofT. britovi,T. nativa,T. pseudospiralis, orT. papuae, respectively. These results showed that the 53-kDa recombinant proteins provide early and species-specific antibody responses in mice infected withTrichinellaspp.
Detection of RNA of Mumps Virus during an Outbreak in a Population with a High Level of Measles, Mumps, and Rubella Vaccine Coverage
Authors: Bitsko Rebecca H. , Cortese Margaret M. , Dayan Gustavo H. , Rota Paul A. , Lowe Luis , Iversen Susan C. , Bellini William J.
Published: January 2008

The duration of mumps virus RNA detection was studied during a mumps outbreak in a highly vaccinated university population. Seven of the eight reverse transcription-PCR-positive specimens were collected during the first 3 days of parotitis, suggesting that viral shedding is minimal after the first 3 days of symptoms.
Neutrophils Play an Essential Role in Cooperation with Antibody in both Protection against and Recovery from Pulmonary Infection with Influenza Virus in Mice
Authors: Fujisawa Haruo
Published: January 2008

The role of polymorphonuclear leukocytes (PMN) in protection in the early phase and recovery in the late phase of influenza A virus infection was investigated by the depletion of PMN in, and passive transfer of anti-influenza virus antiserum to, mice with pulmonary infections. The depletion of PMN in normal mice by treatment with monoclonal antibody RB6-8C5 both increased the mortality rate and pulmonary virus titers from the early to the late phase after infection and delayed virus elimination in the late phase. The passive transfer of the antiserum to normal mice before or after infection abolished pulmonary virus propagation in the early phase, during 3 days, or rapidly decreased high virus titers in the plateau phase, on days 3 to 5, as well as accelerated virus elimination in the late phase, on day 7, after infection, respectively. The passive transfer of the antiserum to PMN-depleted mice could neither prevent the more rapid virus propagation in the early phase, diminish the higher virus titers in the plateau phase, nor accelerate the markedly delayed virus elimination in the late phase after infection in comparison to those for controls. The antibody responses to the virus began to increase on day 7 after infection in normal and PMN-depleted mice. The prevention of virus replication, cytotoxic activity in virus-infected cell cultures, and phagocytosis of the virus in vitro by PMN were all augmented in the presence of the antiserum. These results indicate that PMN play an essential role in virus elimination in both protection against and recovery from infection, in cooperation with the antibody response.
Lentiviral Vectors Encoding Human Immunodeficiency Virus Type 1 (HIV-1)-Specific T-Cell Receptor Genes Efficiently Convert Peripheral Blood CD8 T Lymphocytes into Cytotoxic T Lymphocytes with Potent In Vitro and In Vivo HIV-1-Specific Inhibitory Activity
Authors: Joseph Aviva , Zheng Jian Hua , Follenzi Antonia , DiLorenzo Teresa , Sango Kaori , Hyman Jaime , Chen Ken , Piechocka-Trocha Alicja , Brander Christian , Hooijberg Erik , Vignali Dario A. , Walker Bruce D. , Goldstein Harris
Published: January 2008

The human immunodeficiency virus type 1 (HIV-1)-specific CD8 cytotoxic T-lymphocyte (CTL) response plays a critical role in controlling HIV-1 replication. Augmenting this response should enhance control of HIV-1 replication and stabilize or improve the clinical course of the disease. Although cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection in immunocompromised patients can be treated by adoptive transfer of ex vivo-expanded CMV- or EBV-specific CTLs, adoptive transfer of ex vivo-expanded, autologous HIV-1-specific CTLs had minimal effects on HIV-1 replication, likely a consequence of the inherently compromised qualitative function of HIV-1-specific CTLs derived from HIV-1-infected individuals. We hypothesized that this limitation could be circumvented by using as an alternative source of HIV-1-specific CTLs, autologous peripheral CD8+T lymphocytes whose antigen specificity is redirected by transduction with lentiviral vectors encoding HIV-1-specific T-cell receptor (TCR) α and β chains, an approach used successfully in cancer therapy. To efficiently convert peripheral CD8 lymphocytes into HIV-1-specific CTLs that potently suppress in vivo HIV-1 replication, we constructed lentiviral vectors encoding the HIV-1-specific TCR α and TCR β chains cloned from a CTL clone specific for an HIV Gag epitope, SL9, as a single transcript linked with a self-cleaving peptide. We demonstrated that transduction with this lentiviral vector efficiently converted primary human CD8 lymphocytes into HIV-1-specific CTLs with potent in vitro and in vivo HIV-1-specific activity. Using lentiviral vectors encoding an HIV-1-specific TCR to transform peripheral CD8 lymphocytes into HIV-1-specific CTLs with defined specificities represents a new immunotherapeutic approach to augment the HIV-1-specific immunity of infected patients.
Kaposi's Sarcoma-Associated Herpesvirus ORF57 Functions as a Viral Splicing Factor and Promotes Expression of Intron-Containing Viral Lytic Genes in Spliceosome-Mediated RNA Splicing
Authors: Majerciak Vladimir , Yamanegi Koji , Allemand Eric , Kruhlak Michael , Krainer Adrian R. , Zheng Zhi-Ming
Published: January 2008

Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 facilitates the expression of both intronless viral ORF59 genes and intron-containing viral K8 and K8.1 genes (V. Majerciak, N. Pripuzova, J. P. McCoy, S. J. Gao, and Z. M. Zheng, J. Virol. 81:1062-1071, 2007). In this study, we showed that disruption of ORF57 in a KSHV genome led to increased accumulation of ORF50 and K8 pre-mRNAs and reduced expression of ORF50 and K-bZIP proteins but had no effect on latency-associated nuclear antigen (LANA). Cotransfection of ORF57 and K8β cDNA, which retains a suboptimal intron of K8 pre-mRNA due to alternative splicing, promoted RNA splicing of K8β and production of K8α (K-bZIP). Although Epstein-Barr virus EB2, a closely related homolog of ORF57, had a similar activity in the cotransfection assays, herpes simplex virus type 1 ICP27 was inactive. This enhancement of RNA splicing by ORF57 correlates with the intact N-terminal nuclear localization signal motifs of ORF57 and takes place in the absence of other viral proteins. In activated KSHV-infected B cells, KSHV ORF57 partially colocalizes with splicing factors in nuclear speckles and assembles into spliceosomal complexes in association with low-abundance viral ORF50 and K8 pre-mRNAs and essential splicing components. The association of ORF57 with snRNAs occurs by ORF57-Sm protein interaction. We also found that ORF57 binds K8β pre-mRNAs in vitro in the presence of nuclear extracts. Collectively our data indicate that KSHV ORF57 functions as a novel splicing factor in the spliceosome-mediated splicing of viral RNA transcripts.
Cysteines Flanking the Internal Fusion Peptide Are Required for the Avian Sarcoma/Leukosis Virus Glycoprotein To Mediate the Lipid Mixing Stage of Fusion with High Efficiency
Authors: Delos Sue E. , Brecher Matthew B. , Chen Zaoying , Melder Deborah C. , Federspiel Mark J. , White Judith M.
Published: January 2008

We previously showed that the cysteines flanking the internal fusion peptide of the avian sarcoma/leukosis virus subtype A (ASLV-A) Env (EnvA) are important for infectivity and cell-cell fusion. Here we define the stage of fusion at which the cysteines are required. The flanking cysteines are dispensable for receptor-triggered membrane association but are required for the lipid mixing step of fusion, which, interestingly, displays a high pH onset and a biphasic profile. Second-site mutations that partially restore infection partially restore lipid mixing. These findings indicate that the cysteines flanking the internal fusion peptide of EnvA (and perhaps by analogy Ebola virus glycoprotein) are important for the foldback stage of the conformational changes that lead to membrane merger.
Sialic Acid Is a Cellular Receptor for Coxsackievirus A24 Variant, an Emerging Virus with Pandemic Potential
Authors: Nilsson Emma C. , Jamshidi Fariba , Johansson Susanne M. C. , Oberste M. Steven , Arnberg Niklas
Published: January 2008

Binding to target cell receptors is a critical step in the virus life cycle. Coxsackievirus A24 variant (CVA24v) has pandemic potential and is a major cause of acute hemorrhagic conjunctivitis, but its cellular receptor has hitherto been unknown. Here we show that CVA24v fails to bind to and infect CHO cells defective in sialic acid expression. Binding of CVA24v to and infection of corneal epithelial cells are efficiently inhibited by treating cells with a sialic acid-cleaving enzyme or sialic acid-binding lectins and by treatment of the virus with soluble, multivalent sialic acid. Protease treatment of cells efficiently inhibited virus binding, suggesting that the receptor is a sialylated glycoprotein. Like enterovirus type 70 and influenza A virus, CVA24v can cause pandemics. Remarkably, all three viruses use the same receptor. Since several unrelated viruses with tropism for the eye use this receptor, sialic acid-based antiviral drugs that prevent virus entry may be useful for topical treatment of such infections.
The role of lactate in the exercise-induced human growth hormone response: evidence from McArdle disease
Authors: Godfrey R J , Whyte G P , Buckley J , Quinlivan R
Published: January 2008

Purpose:

Increased blood lactate concentration has been suggested as a primary stimulus for the exercise-induced growth hormone response (EIGR). Patients with McArdle disease are unable to produce lactate in response to exercise and thus offer a unique model to assess the role of lactate in the EIGR. Accordingly, McArdle’s patients were exercised to test the hypothesis that lactate is a major stimulus of the EIGR.

Methods:

11 patients with McArdle disease (3 male, 8 female; age: 35.5 (SD 13.9) years, height: 166 (8) cm, body mass: 75.2 (13.1) kg) were recruited for the study. The patients walked initially at 0.42 m/s, increasing by 0.14 m/s per 3 min stage. Exercise was terminated when participants completed 3 minutes at 1.80 m/s or when a Borg CR10 pain scale rating of “4” was reached. Stages were separated by 60 s for capillary blood sampling for analysis of hGH and blood lactate concentration.

Results:

McArdle’s patients’ blood lactate levels remained at resting levels (0.3–1.2 mmol/l) as exercise intensity increased. Nine out of 11 participants failed to demonstrate an EIGR obtaining hGH values below the clinical definition of a response (>3 μg/l).

Conclusion:

The absence of an EIGR in nine out of 11 participants suggests that lactate could play a major role in the EIGR in humans.
A COMPARATIVE STUDY OF CLUSTERING METHODS FOR MOLECULAR DATA
Authors: WANG LIN , JIANG MINGHU , LU YINGHUA , SUN MINFU , NOE FRANK
Published: January 2008

The research aim is to use three clustering technologies for establishing molecular data model of large size sets by comparison between low energy samples (LES) and local molecular samples (LMS). Hierarchical cluster of multi-level tree distance relation, competitive learning network of similar inputs falling into the same cluster and topological SOM are used to analyze 6242 LES and 5000 LMS. Our experiments show that in SOM, there are 24 to 25 Davies-Boulding clustering index and color map cluster units in the LES more than 10 to 12 in the LMS, which is consistent with the results of hierarchical cluster and competitive learning network in the rough. The hierarchical cluster reflects the biggest inter-cluster distance about 30 for the LES is far larger than that of LMS about 10. The intra-cluster distance of LES about 15 is also far bigger than that of LMS about 3. In SOM, there are more cluster borders of high values (black) reflecting large distance and more clusters in the D-matrix and U-matrix of LES than that of LMS, due to the biggest standard deviation range from -8 to 10 of samples feature of the LES is bigger than that of LMS from -2.5 to 2.5.
COMPARING TIME-VARYING AUTOREGRESSIVE STRUCTURES OF LOCALLY STATIONARY PROCESSES
Authors: SALCEDO GLADYS E. , SATO JOÃO R. , MORETTIN PEDRO A. , TOLOI CLÉLIA M.
Published: January 2008

In this paper, a novel statistical test is introduced to compare two locally stationary time series. The proposed approach is a Wald test considering time-varying autoregressive modeling and function projections in adequate spaces. The covariance structure of the innovations may be also time-varying. In order to obtain function estimators for the time-varying autoregressive parameters, we consider function expansions in splines and wavelet bases. Simulation studies provide evidence that the proposed test has a good performance. We also assess its usefulness when applied to a financial time series.
THE NORMALIZED WAVELET DESCRIPTOR FOR SHAPE RETRIEVAL
Authors: KITH KIMCHENG , VAN WYK BAREND J. , VAN WYK MICHAËL A.
Published: January 2008

In many image analysis applications, such as image retrieval, the shape of an object is of primary importance. In this paper, a new shape descriptor, namely the Normalized Wavelet Descriptor (NWD), which is a generalization and extension of the Wavelet Descriptor (WD), is introduced. The NWD is compared to the Fourier Descriptor (FD), which in image retrieval experiments conducted by Zhang and Lu, outperformed even the Curvature Scale Space Descriptor (CSSD). Image retrieval experiments have been conducted using a dataset containing 2D-contours of 1400 objects extracted from the standard MPEG7 database. For the chosen dataset, our experimental results show that the NWD outperforms the FD.
ITERATIVE REGULARIZATION AND NONLINEAR INVERSE SCALE SPACE BASED ON TRANSLATION INVARIANT WAVELET SHRINKAGE
Authors: LI MIN , HAO BINBIN , FENG XIANGCHU
Published: January 2008

In this paper, we present a new class of iterative regularization methods in the setting of Besov spaces, which can be seen as generalizations of J. Xu's method. By incorporating translation invariant wavelet transform, minimizers of the new methods can be understood as the alternative to translation invariant wavelet shrinkage with weight that is dependent on the wavelet decomposition scale and the Besov smooth order. And we generalize the iterative regularization methods to a new class of nonlinear inverse scale spaces with scale and Besov smooth order dependent weight. The numerical results show an excellent denoising effect and improvement over J. Xu's method.
CONSTRUCTION OF SYMMETRIC TIGHT WAVELET FRAMES FROM QUASI-INTERPOLATORY SUBDIVISION MASKS AND THEIR APPLICATIONS
Authors: JEONG BYEONGSEON , CHOI MYUNGJIN , KIM HONG OH
Published: January 2008

This paper presents tight wavelet frames with two compactly supported symmetric generators of more than one vanishing moments in the Unitary Extension Principle. We determine all possible free tension parameters of the quasi-interpolatory subdivision masks whose corresponding refinable functions guarantee our wavelet frame. In order to reduce shift variance of the standard discrete wavelet transform, we use the three times oversampling filter bank and eventually obtain a ternary (low, middle, high) frequency scale. In applications to signal/image denoising and erasure recovery, the results demonstrate reduced shift variance and better performance of our wavelet frame than the usual wavelet systems such as Daubechies wavelets.
ESTABLISHMENT, SURVIVAL, SALES GROWTH AND ENTRY STRATEGIES OF JAPANESE MNCs SUBSIDIARIES IN INDIA
Authors: RASOULI GHAHROUDI MEHDI , HOSHINO YASUO
Published: January 2008

This empirical study explores first the relationship between operating years and entry strategies based on wholly-owned and joint venture companies. Second, we examine the effects of equity ownership, size, entry strategy and subsidiary age on the sales growth ratio and the subsidiary's survival. Our findings show that in recent periods, the multi-national companies (MNCs) prefer to acquire high levels of equity ownership, including full ownership subsidiaries, especially when the subsidiary is in the manufacturing industry. Our results imply that capital, the age of the venture, the number of employees and full equity ownership affect survival. Finally, we find that subsidiaries with a small number of employees are likely to have a superior sales growth ratio and are more likely to survive.
Herpes Simplex: Insights on Pathogenesis and Possible Vaccines
Authors: Koelle David M. , Corey Lawrence
Published: January 2008

Herpes simplex viruses are evolutionarily ancient and ubiquitous. In the past 20 years, there has been increasing recognition of a worldwide pandemic of HSV-2 infection. Moreover, HSV-2 prevalence has increased despite fairly widespread use of antiviral drugs for HSV. The success of HSV-1 and HSV-2 stems from latency within long-lived neurons and frequent mucocutaneous shedding. The generally mild medical consequences of HSV infection reflect a functional equilibrium between host and microbe in most immunocompetent persons. However, significant gaps in our knowledge of the correlates of disease severity and HSV immune evasion are limiting rational advances in these areas. Human genetic studies are gradually outlining important innate responses, while recent imaging and biopsy studies have begun to show that the temporal and spatial anatomic interplay between virus reactivation and host immune response may be important in reactivations and disease expression.
Expanded Newborn Screening: Implications for Genomic Medicine
Authors: McCabe Linda L. , McCabe Edward R.B.
Published: January 2008

Newborn screening (NBS) represents the largest volume of genetic testing. The 45-year history of NBS has demonstrated its benefits, as well as the importance of an evidence base. The recent addition of tandem mass spectrometry (MS/MS) resulted in a fivefold increase in the number of tests. Experience with MS/MS also showed that laboratory tests are just one part of the NBS system. The lessons learned from NBS will provide important insights as we move into the predictive, preventive, and personalized era of genomic medicine.
Apparent intermediate K conductance channel hyposmotic activation in human lens epithelial cells
Authors: Lauf Peter K. , Misri Sandeep , Chimote Ameet A. , Adragna Norma C.
Published: January 2008

This study explores the nature of K fluxes in human lens epithelial cells (LECs) in hyposmotic solutions. Total ion fluxes, Na-K pump, Cl-dependent Na-K-2Cl (NKCC), K-Cl (KCC) cotransport, and K channels were determined by 85Rb uptake and cell K (Kc) by atomic absorption spectrophotometry, and cell water gravimetrically after exposure to ouabain ± bumetanide (Na-K pump and NKCC inhibitors), and ion channel inhibitors in varying osmolalities with Na, K, or methyl-d-glucamine and Cl, sulfamate, or nitrate. Reverse transcriptase polymerase chain reaction (RT-PCR), Western blot analyses, and immunochemistry were also performed. In isosmotic (300 mosM) media ∼90% of the total Rb influx occurred through the Na-K pump and NKCC and ∼10% through KCC and a residual leak. Hyposmotic media (150 mosM) decreased Kc by a 16-fold higher K permeability and cell water, but failed to inactivate NKCC and activate KCC. Sucrose replacement or extracellular K to >57 mM, but not Rb or Cs, in hyposmotic media prevented Kc and water loss. Rb influx equaled Kc loss, both blocked by clotrimazole (IC50 ∼25 μM) and partially by 1-[(2-chlorophenyl) diphenylmethyl]-1H-pyrazole (TRAM-34) inhibitors of the IK channel KCa3.1 but not by other K channel or connexin hemichannel blockers. Of several anion channel blockers (dihydro-indenyl)oxy]alkanoic acid (DIOA), 4-2(butyl-6,7-dichloro-2-cyclopentylindan-1-on-5-yl)oxybutyric acid (DCPIB), and phloretin totally or partially inhibited Kc loss and Rb influx, respectively. RT-PCR and immunochemistry confirmed the presence of KCa3.1 channels, aside of the KCC1, KCC2, KCC3 and KCC4 isoforms. Apparently, IK channels, possibly in parallel with volume-sensitive outwardly rectifying Cl channels, effect regulatory volume decrease in LECs.
Simultaneous monitoring of cellular depolarization and contraction: a new method to investigate excitability and contractility in isolated smooth muscle cells
Authors: Sevcencu Cristian , Pennisi Cristian Pablo , Yoshida Ken , Gregersen Hans
Published: January 2008

The present experiments were performed to establish a method for simultaneous monitoring of excitation and contraction in isolated smooth muscle cells. The smooth muscle cells were dissociated from the colons of Wistar rats by enzymatic digestion. All the experiments were performed on mixtures of circular and longitudinal cells. In a first set of experiments, focal extracellular potentials (FEPs) and transmembrane action potentials (APs) were simultaneously recorded from the cells by use of extracellular and intracellular pipettes, respectively. In a second set of experiments, cellular contraction induced by chemical stimulation was monitored simultaneous with the FEP recordings. The FEPs had spike and plateau amplitudes of 44.5 ± 2.3 and 8.9 ± 0.7 mV, respectively, and reproduced the general morphology of gastrointestinal APs. The parallel mechanical measurements from the rat colonic cells showed that they shortened with an average peak contraction of 8.8 ± 1.4 μm and an average contraction velocity of 8.2 ± 0.9 μm/s, to develop an average peak force of 1.2 ± 0.2 μN, and generated an average peak power of 36 ± 15 pW. Simultaneous monitoring of FEPs and cellular contraction demonstrates correlations between the electrical and mechanical events taking place in the investigated cells.
Intraesophageal chemicals enhance responsiveness of upper thoracic spinal neurons to mechanical stimulation of esophagus in rats
Authors: Qin Chao , Farber Jay P. , Foreman Robert D.
Published: January 2008

Esophageal hypersensitivity is one of the most common causes of noncardiac chest pain in patients. In this study, we investigated whether exposure of the esophagus to acid and other chemical irritants affected activity of thoracic spinal neurons responding to esophageal distension (ED) in rats. Extracellular potentials of single thoracic (T3) spinal neurons were recorded in pentobarbital sodium-anesthetized, -paralyzed, and -ventilated male rats. ED (0.2 or 0.4 ml, 20 s) was produced by water inflation of a latex balloon placed orally into the middle thoracic region of the esophagus. The chemicals were administered via a tube that was passed through the stomach and placed in the thoracic esophagus. To irritate the esophagus, 0.2 ml of HCl (0.01 N), bradykinin (10 μg/ml), or capsaicin (10 μg/ml) were injected for 1–2 min. Only neurons excited by ED were included in this study. Results showed that intraesophageal instillation of HCl, bradykinin, and capsaicin increased activity in 3/20 (15%), 7/25 (28%), and 9/20 (45%) neurons but enhanced excitatory responses to ED in 9/17 (53%), 8/15 (53%), and 7/11 (64%) of the remaining spinal neurons, respectively. Furthermore, intraesophageal chemicals were more likely to enhance the responsiveness of low-threshold neurons than high-threshold neurons to the esophageal mechanical stimulus. Normal saline (pH 7.4, 0.2 ml) or vehicle instilled in the esophagus did not significantly affect activity or ED responses of neurons. We conclude that enhanced responses of thoracic spinal neurons to ED by the chemically challenged esophagus may provide a possible pathophysiological basis for visceral hypersensitivity in patients with gastroesophageal reflux and/or esophagitis.
Inhibition of bFGF-receptor type 2 increases kidney damage and suppresses nephrogenic protein expression after ischemic acute renal failure
Authors: Villanueva Sandra , Cespedes Carlos , Gonzalez Alexis A. , Roessler Eric , Vio Carlos P.
Published: January 2008

Recovery from acute renal failure (ARF) requires the replacement of injured cells by new cells that are able to restore tubule epithelial integrity. We have recently described the expression of nephrogenic proteins [Vimentin, neural cell adhesion molecule, basic fibroblast growth factor (bFGF), Pax-2, bone morphogen protein-7, Noggin, Smad 1-5-8, p-Smad, hypoxia-inducible factor-1α, vascular endothelial growth factor], in a time frame similar to that observed in kidney development, after ischemic ARF induced in an ischemia-reperfusion (I/R) model. Furthermore, we show that bFGF, a morphogen involved in mesenchyme/epithelial transition in kidney development, induces a reexpression of morphogenic proteins in an earlier time frame and accelerates the recovery process after renal damage. Herein, we confirm that renal morphogenes are modulated by bFGF and hypothesized that a decrease in bFGF receptor 2 (bFGFR2) levels by the use of antisense oligonucleotides diminishes the expression of morphogenes. Male Sprague-Dawley rats submitted to ischemic injury were injected with 112 μg/kg bFGFR2 antisense oligonucleotide (bFGFR2-ASO) followed by reperfusion. Rats were killed, and the expression of nephrogenic proteins and renal marker damage was analyzed by immunohistochemistry and immunoblot. Animals subjected to I/R treated with bFGFR2-ASO showed a significant reduction in morphogen levels ( P < 0.05). In addition, we observed an increase in markers of renal damage: macrophages (ED-1) and interstitial α-smooth muscle actin. These results confirm that bFGF participates in the recovery process and that treatment with bFGFR2-ASO induces an altered expression of morphogen proteins.
Transcription of laminin γ1 chain gene in rat mesangial cells: constitutive and inducible RNA polymerase II recruitment and chromatin states
Authors: Nelson Joel D. , Flanagin Steve , Kawata Yasunobu , Denisenko Oleg , Bomsztyk Karol
Published: January 2008

The laminin γ1 chain, a critical component of the extracellular matrix, is encoded by the 125-kb-long Lamc1 locus. We profiled RNA polymerase II (Pol II) and histone modifications along the Lamc1 locus to explore transcription of this gene in its native chromatin environment. Treatment with 12-O-tetradecanoylphorbol-13-acetate increased Lamc1 mRNA in rat mesangial cells (RMC). This increase was matched by an increase in Pol II density along the entire length of the Lamc1 locus. In contrast, in the hepatocarcinoma cell line (HTC-IR) an increase in Pol II density was restricted to the promoter and was not followed by mRNA induction. The pattern of histone H3 methylation was similar for both cell types but an increase in H3 lysine 9 acetylation observed at the 5′-end was weaker in HTC-IR cells than in RMC. All of the histone modifications showed spatial patterns where levels differed greatly between the 5′- and 3′-ends of Lamc1. Conversely, at the short, highly induced egr-1 gene the differences in chromatin marks between the 5′- and 3′-ends were much smaller. The results of this study suggest that 1) Lamc1 transcription can be controlled after transcription initiation, to our knowledge, the first time this has been shown in an extracellular matrix gene, and 2) the length of a gene is a factor that can affect the chromatin environment for Pol II elongation.
Acid-base analysis: a critique of the Stewart and bicarbonate-centered approaches
Authors: Kurtz Ira , Kraut Jeffrey , Ornekian Vahram , Nguyen Minhtri K.
Published: January 2008

When approaching the analysis of disorders of acid-base balance, physical chemists, physiologists, and clinicians, tend to focus on different aspects of the relevant phenomenology. The physical chemist focuses on a quantitative understanding of proton hydration and aqueous proton transfer reactions that alter the acidity of a given solution. The physiologist focuses on molecular, cellular, and whole organ transport processes that modulate the acidity of a given body fluid compartment. The clinician emphasizes the diagnosis, clinical causes, and most appropriate treatment of acid-base disturbances. Historically, two different conceptual frameworks have evolved among clinicians and physiologists for interpreting acid-base phenomena. The traditional or bicarbonate-centered framework relies quantitatively on the Henderson-Hasselbalch equation, whereas the Stewart or strong ion approach utilizes either the original Stewart equation or its simplified version derived by Constable. In this review, the concepts underlying the bicarbonate-centered and Stewart formulations are analyzed in detail, emphasizing the differences in how each approach characterizes acid-base phenomenology at the molecular level, tissue level, and in the clinical realm. A quantitative comparison of the equations that are currently used in the literature to calculate H+concentration ([H+]) is included to clear up some of the misconceptions that currently exist in this area. Our analysis demonstrates that while the principle of electroneutrality plays a central role in the strong ion formulation, electroneutrality mechanistically does not dictate a specific [H+], and the strong ion and bicarbonate-centered approaches are quantitatively identical even in the presence of nonbicarbonate buffers. Finally, our analysis indicates that the bicarbonate-centered approach utilizing the Henderson-Hasselbalch equation is a mechanistic formulation that reflects the underlying acid-base phenomenology.