bluuebunny/crossref_metadata_2025 huggingface dataset:
Early alterations in myocardia and vessels of the diabetic rat heart: an FTIR microspectroscopic study
Authors: Toyran Neslihan , Lasch Peter , Naumann Dieter , Turan Belma , Severcan Feride
Published: July 2006

Diabetes mellitus is associated with a high incidence and poor prognosis of cardiovascular disease. The aim of the present study was to examine the effect of relatively short-term (5 weeks) Type I diabetes on the left ventricle, the right ventricle and the vessel (vein) on the left ventricle of the myocardium at molecular level by FTIR (Fourier-transform infrared) microspectroscopy. The rats were categorized into two groups: control group (for the left ventricle myocardium, n=8; for the right ventricle myocardium, n=9; for the vein, n=9) and streptozotocin-induced diabetic group (for the left ventricle myocardium, n=7; for the right ventricle myocardium, n=9; for the vein, n=8). Two adjacent cross-sections of 9 μm thickness were taken from the ventricles of the hearts in two groups of rats by using a cryotome. The first sections were used for FTIR microspectroscopy measurements. The second serial sections were stained by haematoxylin/eosin for comparative purposes. Diabetes caused an increase in the content of lipids, an alteration in protein profile with a decrease in α-helix and an increase in β-sheet structure as well as an increase in glycogen and glycolipid contents in both ventricles and the vein. Additionally, the collagen content was found to be increased in the vein of the diabetic group. The present study demonstrated that diabetes-induced alterations in the rat heart can be detected by correlating the IR spectral changes with biochemical profiles in detail. The present study for the first time demonstrated the diabetes-induced alterations at molecular level in both ventricle myocardia and the veins in relatively short-term diabetes.
Disruption of inositol biosynthesis through targeted mutagenesis in Dictyostelium discoideum: generation and characterization of inositol-auxotrophic mutants
Authors: Fischbach Andreas , Adelt Stephan , Müller Alexander , Vogel Günter
Published: July 2006

myo-Inositol and its downstream metabolites participate in diverse physiological processes. Nevertheless, considering their variety, it is likely that additional roles are yet to be uncovered. Biosynthesis of myo-inositol takes place via an evolutionarily conserved metabolic pathway and is strictly dependent on inositol-3-phosphate synthase (EC 5.5.1.4). Genetic manipulation of this enzyme will disrupt the cellular inositol supply. Two methods, based on gene deletion and antisense strategy, were used to generate mutants of the cellular slime mould Dictyostelium discoideum. These mutants are inositol-auxotrophic and show phenotypic changes under inositol starvation. One remarkable attribute is their inability to live by phagocytosis of bacteria, which is the exclusive nutrient source in their natural environment. Cultivated on fluid medium, the mutants lose their viability when deprived of inositol for longer than 24 h. Here, we report a study of the alterations in the first 24 h in cellular inositol, inositol phosphate and phosphoinositide concentrations, whereby a rapidly accumulating phosphorylated compound was detected. After its identification as 2,3-BPG (2,3-bisphosphoglycerate), evidence could be found that the internal disturbances of inositol homoeostasis trigger the accumulation. In a first attempt to characterize this as a physiologically relevant response, the efficient in vitro inhibition of a D. discoideum inositol-polyphosphate 5-phosphatase (EC 3.1.3.56) by 2,3-BPG is presented.
Binding of amyloid β-peptide to ganglioside micelles is dependent on histidine-13
Authors: Williamson Mike P. , Suzuki Yu , Bourne Nathan T. , Asakura Tetsuo
Published: July 2006

Amyloid β-peptide (Aβ) is a major component of plaques in Alzheimer's disease, and formation of senile plaques has been suggested to originate from regions of neuronal membrane rich in gangliosides. Here we demonstrate using NMR on 15N-labelled Aβ-(1–40) and Aβ-(1–42) that the interaction with ganglioside GM1 micelles is localized to the N-terminal region of the peptide, particularly residues His13 to Leu17, which become more helical when bound. The key interaction is with His13, which undergoes a GM1-specific conformational change. The sialic acid residue of the ganglioside headgroup is important for determining the nature of the conformational change. The isolated pentasaccharide headgroup of GM1 is not bound, suggesting the need for a polyanionic surface. Binding to heparin confirms this suggestion, since binding is of similar affinity but does not produce the same conformational changes in the peptide. A comparison of Aβ-(1–40) and Aβ-(1–42) indicates that binding to GM1 micelles is not related to oligomerization, which occurs at the C-terminal end. These results imply that binding to ganglioside micelles causes a transition from random coil to α-helix in the N-terminal region, leaving the C-terminal region unstructured.
Anticoagulant proteins from snake venoms: structure, function and mechanism
Authors: Kini R. Manjunatha
Published: July 2006

Over the last several decades, research on snake venom toxins has provided not only new tools to decipher molecular details of various physiological processes, but also inspiration to design and develop a number of therapeutic agents. Blood circulation, particularly thrombosis and haemostasis, is one of the major targets of several snake venom proteins. Among them, anticoagulant proteins have contributed to our understanding of molecular mechanisms of blood coagulation and have provided potential new leads for the development of drugs to treat or to prevent unwanted clot formation. Some of these anticoagulants exhibit various enzymatic activities whereas others do not. They interfere in normal blood coagulation by different mechanisms. Although significant progress has been made in understanding the structure–function relationships and the mechanisms of some of these anticoagulants, there are still a number of questions to be answered as more new anticoagulants are being discovered. Such studies contribute to our fight against unwanted clot formation, which leads to death and debilitation in cardiac arrest and stroke in patients with cardiovascular and cerebrovascular diseases, arteriosclerosis and hypertension. This review describes the details of the structure, mechanism and structure–function relationships of anticoagulant proteins from snake venoms.
Evolution of two alanine glyoxylate aminotransferases in mosquito
Authors: Han Qian , Kim Seong Ryul , Ding Haizhen , Li Jianyong
Published: July 2006

In the mosquito, transamination of 3-HK (3-hydroxykynurenine) to XA (xanthurenic acid) is catalysed by an AGT (alanine glyoxylate aminotransferase) and is the major branch pathway of tryptophan metabolism. Interestingly, malaria parasites hijack this pathway to use XA as a chemical signal for development in the mosquito. Here, we report that the mosquito has two AGT isoenzymes. One is the previously cloned AeHKT [Aedes aegypti HKT (3-HK transaminase)] [Han, Fang and Li (2002) J. Biol. Chem. 277, 15781–15787], similar to hAGT (human AGT), which primarily catalyses 3-HK to XA in mosquitoes, and the other is a typical dipteran insect AGT. We cloned the second AGT from Ae. aegypti mosquitoes [AeAGT (Ae. aegypti AGT)], overexpressed the enzyme in baculovirus/insect cells and determined its biochemical characteristics. We also expressed hAGT for a comparative study. The new cloned AeAGT is highly substrate-specific when compared with hAGT and the previously reported AeHKT and Drosophila AGT, and is translated mainly in pupae and adults, which contrasts with AeHKT that is expressed primarily in larvae. Our results suggest that the physiological requirements of mosquitoes and the interaction between the mosquito and its host appear to be the driving force in mosquito AGT evolution.
Intravenous hydration with a 2.5% glucose solution in Type II diabetes
Authors: Sjöstrand Fredrik , Nyström Thomas , Hahn Robert G.
Published: July 2006

Physicians are often unclear about how fast intravenous glucose solutions should be administered to adequately hydrate patients with Type II diabetes while avoiding hyperglycaemia and excessive plasma volume expansion. The aim of the present study was to analyse the disposition of a 2.5% glucose solution and create a nomogram which could serve as a guide to fluid therapy in these patients. Twelve males (mean body mass index, 29 kg/m2) with Type II diabetes due to insulin resistance, as quantified by an euglycaemic hyperinsulinaemic glucose clamp, received an infusion of iso-osmotic 2.5% glucose solution with electrolytes (70 mmol/l sodium, 45 mmol/l chloride and 25 mmol/l acetate) at individual rates over 30 and 60 min respectively. Blood glucose and haemoglobin levels were measured repeatedly over 3.5 h to estimate the kinetics of glucose and fluid volume. Mean insulin sensitivity was 4.2×10−4 dl·kg−1·min−1·(μ-units/ml)−1. The individualized infusion rates reached the predetermined blood glucose level of 12 mmol/l with a mean difference of 0.2 mmol/l. The disposition of glucose was an important factor governing fluid distribution. The volume of distribution of exogenous glucose averaged 19.8 litres, but for the fluid volume it was only 3.7 litres. The clearance was 0.37 litre/min for glucose and 0.10 litre/min for the fluid volume, and the results of the 30-min and 60-min infusions agreed reasonably well. It is concluded that kinetic analysis can be used to guide the infusion time and infusion rate of 2.5% glucose to reach any predetermined glucose level and volume expansion.
Detection of elevated pulmonary capillary wedge pressure in elderly patients with various cardiac disorders by the Valsalva manoeuvre
Authors: Remmen Jaap J. , Aengevaeren Wim R. M. , Verheugt Freek W. A. , Jansen René W. M. M.
Published: July 2006

In the present study, we assessed whether elevated (≥15 mmHg) PCWP (pulmonary capillary wedge pressure) can be detected using the blood pressure response to the Valsalva manoeuvre in a group of elderly patients with various cardiac disorders, including atrial fibrillation and valvular heart disease, and healthy elderly controls. The Valsalva manoeuvre was performed in 93 patients (71±4 years) and 28 healthy controls (70±4 years) undergoing right-sided cardiac catheterization. Blood pressure was measured non-invasively with Finapres. PPR (pulse pressure ratio), the ratio of minimum pulse pressure during phase 2 and maximum pulse pressure during phase 1 of the Valsalva manoeuvre, was correlated with PCWP (r=0.63, P<0.001). The area under the receiver operator characteristic curve of PPR with elevated PCWP was 0.85 (P<0.001). For PPR=0.62, sensitivity for elevated PCWP was 80%, specificity was 79%, positive predictive value was 76% and negative predictive value was 83%. Correlation of PPR with PCWP and the ability of PPR to detect elevated PCWP was present in atrial fibrillation, heart failure and valvular heart disease. In conclusion, PPR is a sensitive and specific instrument to diagnose elevated PCWP non-invasively in a large group of elderly patients with various cardiac disorders. This makes the Valsalva manoeuvre a useful non-invasive tool for diagnosing heart failure, applicable in elderly patients with common cardiac disorders, such as atrial fibrillation and valvular heart disease.
White blood cell and hormonal responses to 4300 m altitude before and after intermittent altitude exposure
Authors: Beidleman Beth A. , Muza Stephen R. , Fulco Charles S. , Cymerman Allen , Staab Janet E. , Sawka Michael N. , Lewis Steven F. , Skrinar Gary S.
Published: July 2006

Recent studies have demonstrated that brief daily IAE (intermittent altitude exposure) was equally as effective as continuous altitude residence in inducing physiological adaptations consistent with altitude acclimatization. Although the positive benefits of IAE have been clearly defined, the potential negative consequences of IAE on health, specifically the immune system, remain undefined. The present study determined the effects of IAE on WBC (white blood cell) and hormonal responses during rest and exercise at 4300 m altitude. Six lowlanders (age, 23±2 years; body weight, 77±6 kg; values are means±S.E.M.) completed a V̇O2max (maximal O2 uptake) and submaximal cycle ergometer test during a 30-h SL (sea level) exposure and during a 30 h exposure to 4300 m altitude-equivalent once before (PreIAE) and once after (PostIAE) a 3-week period of IAE (4 h·day−1, 5 days·week−1, 4300 m). The submaximal cycle ergometer test consisted of two consecutive 15-min work bouts at 40% and 70% of altitude-specific V̇O2max. Blood samples were obtained at rest and during both exercise work bouts for measurements of WBC count, leucocyte subset counts, cortisol, adrenaline (epinephrine) and noradrenaline (norepinephrine). WBC, neutrophil and lymphocyte counts increased significantly (P<0.05) during rest and exercise from SL to PreIAE and decreased (P<0.05) during rest and exercise from PreIAE to PostIAE. Monocyte counts decreased (P<0.05) during rest and exercise from PreIAE to PostIAE, but eosinophil and basophil counts did not change. Cortisol, adrenaline and noradrenaline did not change during rest or exercise from SL to PreIAE or PostIAE, but all increased significantly (P<0.05) from rest during the two work bouts. In conclusion, this type of IAE stimulus did not induce a hormonal stress response and did no harm in terms of activation of the immune system at altitude, as measured by WBC and leucocyte subset counts. This method of pre-acclimatization can therefore be highly recommended for inducing altitude acclimatization without the ‘altitude residency’ requirement.
Whitham systems and deformations
Authors: Maltsev A. Ya.
Published: July 2006

We consider the deformations of Whitham systems including the “dispersion terms” and having the form of Dubrovin-Zhang deformations of Frobenius manifolds. The procedure is connected with the B. A. Dubrovin problem of deformations of Frobenius manifolds corresponding to the Whitham systems of integrable hierarchies. Under some nondegeneracy requirements we suggest a general scheme of the deformation of the hyperbolic Whitham systems using the initial nonlinear system. The general form of the deformed Whitham system coincides with the form of the “low-dispersion” asymptotic expansions used by B. A. Dubrovin and Y. Zhang in the theory of deformations of Frobenius manifolds.
Geometrical classification of Killing tensors on bidimensional flat manifolds
Authors: Chanu C. , Degiovanni L. , McLenaghan R. G.
Published: July 2006

Valence two Killing tensors in the Euclidean and Minkowski planes are classified under the action of the group which preserves the type of the corresponding Killing web. The classification is based on an analysis of the system of determining partial differential equations for the group invariants and is entirely algebraic. The approach allows one to classify both characteristic and noncharacteristic Killing tensors.
Tomographic reconstruction of deformed internal structure of a field-reversed configuration
Authors: Asai T. , Takahashi T. , Kiguchi T. , Matsuzawa Y. , Nogi Y.
Published: July 2006

Deformation of the internal structure of a field-reversed configuration (FRC) was studied using a tomographic reconstruction technique. A simple and configurable tomographic system was developed, with which the time evolution of the FRC internal structure was reconstructed. In the latter phase of equilibrium, a FRC has a well-known global rotational instability with toroidal mode number n=2. It has been believed that elliptical deformation of the FRC allows interaction between the wall and the plasma, which terminates this configuration. However, these experiments revealed the FRC to deform into a dumbbell-like structure before the edge hits the chamber wall, leading to the disruption phase. In addition, an internal shift (toroidal mode number n=1) mode was observed in the equilibrium phase, followed by growth of n=2 rotational instability.
Coil–globule transition in the denatured state of a small protein
Authors: Sherman Eilon , Haran Gilad
Published: July 2006

Upon transfer from strongly denaturing to native conditions, proteins undergo a collapse that either precedes folding or occurs simultaneously with it. This collapse is similar to the well known coil–globule transition of polymers. Here we employ single-molecule fluorescence methods to fully characterize the equilibrium coil–globule transition in the denatured state of the IgG-binding domain of protein L. By using FRET measurements on freely diffusing individual molecules, we determine the radius of gyration of the protein, which shows a gradual expansion as the concentration of the denaturant, guanidinium hydrochloride, is increased all the way up to 7 M. This expansion is observed also in fluorescence correlation spectroscopy measurements of the hydrodynamic radius of the protein. We analyze the radius of gyration measurements using the theory of the coil–globule transition of Sanchez [Sanchez, I. C. (1979)
Macromolecules
12, 980–988], which balances the excluded volume entropy of the chain with the average interresidue interaction energy. In particular, we calculate the solvation energy of the denatured protein, a property that is not readily accessible in other experiments. The dependence of this energy on denaturant concentration is nonlinear, contrasting with the common linear extrapolation method used to describe denaturation energy. Interestingly, a fit to the binding model of chemical denaturation suggests a single denaturant binding site per protein residue. The size of the denatured protein under native conditions can be extrapolated from the data as well, showing that the fully collapsed state of protein is only ≈10% larger than the folded state.
A Mazandarani Account of the Babi Incident at Shaikh Tabarsi
Authors: Borjian Habib
Published: July 2006

This article transcribes and glosses a nineteenth-century Mazandarani document on Babi-state conflict at Shaikh Tabarsi. Collected in 1860 in the town of Barfurush, it was published five years later by Boris Andreevich Dorn in Perso-Arabic characters. The text is the first known prose document based on natural speech in the modern Mazandarani language. The language of the text is fundamentally the same as that spoken today in the Persian province of Mazandaran, located south of the Caspian Sea. As one expects, however, there are certain extinct traits in the text, which could be identified only by comparison with other surviving Mazandarani documents of the same period. The text will contribute to the study of the largely understudied language of Mazandaran, particularly to its development since the composition of the text. It may also serve as a supplementary historical document for the historic incident it narrates.
Exit from mitosis triggers Chs2p transport from the endoplasmic reticulum to mother–daughter neck via the secretory pathway in budding yeast
Authors: Zhang Gang , Kashimshetty Rohini , Ng Kwee Eng , Tan Heng Buck , Yeong Foong May
Published: July 2006

Budding yeast chitin synthase 2 (Chs2p), which lays down the primary septum, localizes to the mother–daughter neck in telophase. However, the mechanism underlying the timely neck localization of Chs2p is not known. Recently, it was found that a component of the exocyst complex, Sec3p–green fluorescent protein, arrives at the neck upon mitotic exit. It is not clear whether the neck localization of Chs2p, which is a cargo of the exocyst complex, was similarly regulated by mitotic exit. We report that Chs2p was restrained in the endoplasmic reticulum (ER) during metaphase. Furthermore, mitotic exit was sufficient to cause Chs2p neck localization specifically by triggering the Sec12p-dependent transport of Chs2p out of the ER. Chs2p was “forced” prematurely to the neck by mitotic kinase inactivation at metaphase, with chitin deposition occurring between mother and daughter cells. The dependence of Chs2p exit from the ER followed by its transport to the neck upon mitotic exit ensures that septum formation occurs only after the completion of mitotic events.
On 𝐶^{∞} and Gevrey regularity of sublaplacians
Authors: Himonas A. , Petronilho Gerson
Published: July 2006

In this paper we consider zero order perturbations of a class of sublaplacians on the two-dimensional torus and give sufficient conditions for global

C
∞

C^\infty

regularity to persist. In the case of analytic coefficients, we prove Gevrey regularity for a general class of sublaplacians when the finite type condition holds.
The intersection of a matroid and a simplicial complex
Authors: Aharoni Ron , Berger Eli
Published: July 2006

A classical theorem of Edmonds provides a min-max formula relating the maximal size of a set in the intersection of two matroids to a “covering" parameter. We generalize this theorem, replacing one of the matroids by a general simplicial complex. One application is a solution of the case

r
=
3

r=3

of a matroidal version of Ryser’s conjecture. Another is an upper bound on the minimal number of sets belonging to the intersection of two matroids, needed to cover their common ground set. This, in turn, is used to derive a weakened version of a conjecture of Rota. Bounds are also found on the dual parameter—the maximal number of disjoint sets, all spanning in each of two given matroids. We study in detail the case in which the complex is the complex of independent sets of a graph, and prove generalizations of known results on “independent systems of representatives" (which are the special case in which the matroid is a partition matroid). In particular, we define a notion of

k
k

-matroidal colorability of a graph, and prove a fractional version of a conjecture, that every graph

G
G

is

2
Δ
(
G
)

2\Delta (G)

-matroidally colorable. The methods used are mostly topological.
Partitioning 𝛼–large sets: Some lower bounds
Authors: Bigorajska Teresa , Kotlarski Henryk
Published: July 2006

Let

α
→
(
β

)
m
r

\alpha \rightarrow (\beta )_m^r

denote the property: if

A
A

is an

α
\alpha

–large set of natural numbers and

[
A

]
r

[A]^r

is partitioned into

m
m

parts, then there exists a

β
\beta

–large subset of

A
A

which is homogeneous for this partition. Here the notion of largeness is in the sense of the so–called Hardy hierarchy. We give a lower bound for

α
\alpha

in terms of

β
,
m
,
r

\beta ,m,r

for some specific

β
\beta

.
Multiplier ideals of hyperplane arrangements
Authors: Mustaţǎ Mircea
Published: July 2006

In this note we compute multiplier ideals of hyperplane arrangements. This is done using the interpretation of multiplier ideals in terms of spaces of arcs by Ein, Lazarsfeld, and Mustaţǎ (2004).
A Hurewicz-type theorem for asymptotic dimension and applications to geometric group theory
Authors: Bell G. , Dranishnikov A.
Published: July 2006

We prove an asymptotic analog of the classical Hurewicz theorem on mappings that lower dimension. This theorem allows us to find sharp upper bound estimates for the asymptotic dimension of groups acting on finite-dimensional metric spaces and allows us to prove a useful extension theorem for asymptotic dimension. As applications we find upper bound estimates for the asymptotic dimension of nilpotent and polycyclic groups in terms of their Hirsch length. We are also able to improve the known upper bounds on the asymptotic dimension of fundamental groups of complexes of groups, amalgamated free products and the hyperbolization of metric spaces possessing the Higson property.
Partial hyperbolicity or dense elliptic periodic points for 𝐶¹-generic symplectic diffeomorphisms
Authors: Saghin Radu , Xia Zhihong
Published: July 2006

We prove that if a symplectic diffeomorphism is not partially hyperbolic, then with an arbitrarily smallC1C^1perturbation we can create a totally elliptic periodic point inside any given open set. As a consequence, aC1C^1-generic symplectic diffeomorphism is either partially hyperbolic or it has dense elliptic periodic points. This extends the similar results of S. Newhouse in dimension 2 and M.-C. Arnaud in dimension 4. Another interesting consequence is that stably ergodic symplectic diffeomorphisms must be partially hyperbolic, a converse to Shub-Pugh’s stable ergodicity conjecture for the symplectic case.
Transcytosis of Human immunodeficiency virus 1 across the placenta is enhanced by treatment with tumour necrosis factor alpha
Authors: Parry Samuel , Zhang Jian , Koi Hideki , Arechavaleta-Velasco Fabian , Elovitz Michal A.
Published: July 2006

The human placenta is relatively resistant toHuman immunodeficiency virus 1(HIV-1), but obstetric complications associated with inflammatory processes, including chorioamnionitis and spontaneous preterm delivery, are associated with increased rates of vertical transmission. It was hypothesized that the pro-inflammatory mediator tumour necrosis factor alpha (TNF-α), which promotes HIV-1 transmission across endothelial membranes, increases HIV-1 transmission across the placenta. Flow cytometry and immunostaining studies were performed, which demonstrated that the HIV-1 receptors CD4, CCR5 and CXCR4 were not expressed by villous trophoblast cells. Consequently, primary villous trophoblast cells were not infected with cell-free HIV-1 isolates, as measured byin situPCR and quantitative PCR, but villous trophoblast cells were infected by HIV-1-infected peripheral blood mononuclear cells (PBMC). HIV-1 from infected PBMC was rapidly transported across confluent transformed trophoblast cell monolayers by transcytosis, and TNF-αsignificantly upregulated transcytosis of HIV-1 across the trophoblast layer without disrupting cell viability or confluency. Inhibitors of TNF-α(antibodies against TNF-αand TNF-αreceptors) and an anti-inflammatory drug (tenidap) significantly reduced transcytosis rates. It was concluded that the villous trophoblast is resistant to infection by cell-free HIV-1 but susceptible to transcytosis of HIV-1 from infected PBMC, and inflammatory mediators such as TNF-αmay play a critical role in promoting maternal–fetal transmission of HIV-1.
Human cytomegalovirus modulation of CCR5 expression on myeloid cells affects susceptibility to human immunodeficiency virus type 1 infection
Authors: King Christine A. , Baillie Joan , Sinclair John H.
Published: July 2006

For some time there has been evidence suggesting an interaction between human cytomegalovirus (HCMV) andHuman immunodeficiency virus(HIV) in the pathogenesis of AIDS. Here, the interaction of HCMV and HIV-1 was examined in monocyte/macrophage cells, two cell types known to be targets for both virusesin vivo. Infection experiments demonstrated that prior infection with HCMV impeded subsequent superinfection with HIV-1. In contrast, uninfected bystander cells within the population were still permissive for HIV-1 infection and were also found to express increased levels of Gag after HIV-1 superinfection. Analysis of CCR5, a co-receptor for HIV-1, on HCMV-infected and bystander cells showed a substantial loss of surface CCR5 expression on infected cells due to HCMV-induced reduction of total cellular CCR5. In contrast, uninfected bystander cells displayed increased surface CCR5 expression. Furthermore, the data suggested that soluble factor(s) secreted from HCMV-infected cells were responsible for the observed upregulation of CCR5 on uninfected bystander cells. Taken together, these results suggest that, whilst HCMV-infected monocytes/macrophages are refractory to infection with HIV-1, HCMV-uninfected bystander cells within a population are more susceptible to HIV-1 infection. On this basis, HCMV infection may contribute to the pathogenesis of HIV-1.
Avipoxvirus phylogenetics: identification of a PCR length polymorphism that discriminates between the two major clades
Authors: Jarmin Susan , Manvell Ruth , Gough Richard E. , Laidlaw Stephen M. , Skinner Michael A.
Published: July 2006

Avipoxvirus infections have been observed in an extensive range of wild, captive and domesticated avian hosts, yet little is known about the genome diversity and host-range specificity of the causative agent(s). Genome-sequence data are largely restricted toFowlpox virus(FWPV) andCanarypox virus(CNPV), which have been sequenced completely, showing considerable divergence between them. It is therefore proving difficult, by empirical approaches, to identify pan-genus, avipoxvirus-specific oligonucleotide probes for PCR and sequencing to support phylogenetic studies. A previous preliminary study used thefpv167 locus, which encodes orthologues of vaccinia virus core protein P4b (A3). PCRper sedid not discriminate between viruses, but restriction-enzyme or sequence analysis indicated that the avipoxviruses clustered either with FWPV or with CNPV. Here, further study of the P4b locus demonstrated a third cluster, from psittacine birds. A newly identified locus, flankingfpv140 (orthologue of vaccinia virus H3L), confirms the taxonomic structure. This locus is particularly useful in that viruses from the fowlpox-like and canarypox-like clusters can be discriminated by PCR on the basis of fragment size, whilst sequence comparison allows discrimination for the first time betweenPigeonpox virusandTurkeypox virus. Except within the psittacines, virus and avian host taxonomies do not show tight correlation, with viruses from the same species located in very different clades. Nor are all the existing recognized avipoxvirus species, defined primarily by avian host species (such as CNPV andSparrowpox virus), resolved within the present structure.
Herpes simplex virus 1 (HSV-1) DNA and immune complex (HSV-1–human IgG) elicit vigorous interleukin 6 release from infected corneal cells via Toll-like receptors
Authors: Hayashi Kozaburo , Hooper Laura C. , Chin Marian S. , Nagineni Chandrasekharam N. , Detrick Barbara , Hooks John J.
Published: July 2006

Toll-like receptor 3 (TLR-3) and TLR-9 gene expression and interleukin 6 (IL-6) secretion were studied in corneal cells with components of herpes simplex virus (HSV). Human corneal epithelial cells (HCEs) and primary human corneal fibroblasts (HCRFs) were infected with live HSV or UV-inactivated HSV (UV-HSV), transfected with HSV DNA or treated with HSV–anti-HSV IgG immune complexes. Gene expression of TLR-3 and -9 was analysed by real-time PCR. Supernatants were assayed for IL-6 by ELISA. Incubation of HCEs and HCRFs with live HSV-1, UV-HSV and HSV DNA resulted in augmented TLR-3 and -9 gene expression and IL-6 release. Moreover, infected or transfected HCRFs released greater amounts of IL-6 than did HCEs. As virus is frequently in the form of neutralized virus immune complexes, the ability of these immune complexes to interact with TLRs and trigger IL-6 production was evaluated. Here, it is shown that HSV–anti-HSV IgG complexes were as potent as HSV DNA in their ability to induce IL-6. Treatment of HCRFs transfected with HSV DNA with the TLR-9-inhibitory oligomer iODN, anti-TLR-3 antibody or phosphatidylinositol 3-kinase inhibitor indicated that IL-6 release from HCRFs was mediated by TLR-3 and -9 gene expression. These results demonstrated that neutralized HSV immune complexes were as potent as HSV DNA in enhancing IL-6 release from corneal fibroblasts. These phenomena were mediated via augmented TLR-3 and -9 gene expression.
A new phylogenetic lineage of Rabies virus associated with western pipistrelle bats (Pipistrellus hesperus)
Authors: Franka Richard , Constantine Denny G. , Kuzmin Ivan , Velasco-Villa Andres , Reeder Serena A. , Streicker Daniel , Orciari Lillian A. , Wong Anna J. , Blanton Jesse D. , Rupprecht Charles E.
Published: July 2006

Bats represent the major source of human rabies cases in the New World. In the USA, most cases are associated with species that are not commonly found or reported rabid. To understand better the epidemiology and public health significance of potentially important bat species, a molecular study was performed on samples collected from naturally infected rabid western pipistrelle (Pipistrellus hesperus), eastern pipistrelle (Pipistrellus subflavus) and silver-haired bats (Lasionycteris noctivagans) from different regions of their geographical distribution in the USA. A 264 bp fragment at the 5′ end of the N gene coding region was sequenced and analysed in comparison with rabies virus variants circulating within other North American mammals. Phylogenetic analysis demonstrated that P. hesperus bats maintain a unique rabies virus variant. Preliminary data also suggest that P. subflavus and Lasionycteris noctivagans may harbour two different rabies virus variants (Ps and Ln) that are likely to be maintained independently by each bat species, which recently appear to have emerged as major vectors of human disease.
Hepatitis C virus interacts with human platelet glycoprotein VI
Authors: Zahn Astrid , Jennings Nicola , Ouwehand Willem H. , Allain Jean-Pierre
Published: July 2006

Hepatitis C virus (HCV) interacts with human platelets in vivo as a potential transport of infectious virions to the target liver. The binding of native viral particles with the platelet membrane glycoprotein VI (GPVI) was analysed. A consistent interaction between HCV from plasma or after purification by two different methods and the recombinant extracellular immunoglobulin (Ig)-like domains of human GPVI (hD1D2) was observed with two independent experimental approaches: pull-down and ELISA assays. Between 2 and 7 % of HCV particles were specifically bound to hD1D2. The binding was inhibited by an anti-hD1D2 in a dose-dependent manner. Human D1D2 interaction with HCV was significantly higher than the murine D1D2, supporting the specificity of the interaction and to the single human domains (D1 and D2), suggesting that both Ig-like domains of the molecule are required for efficient binding. GPVI may be a platelet surface ligand for HCV playing a role in viral transport and persistence.
Detection of 6K1 as a mature protein of 6 kDa in plum pox virus-infected Nicotiana benthamiana
Authors: Waltermann Angelika , Maiss Edgar
Published: July 2006

The RNA genome of Plum pox virus (PPV) encodes one large polyprotein that is subsequently cleaved into mature viral proteins. One of the products of proteolytic processing, the 6K1 protein, has not yet been identified in vivo for any member of the genus Potyvirus. In this study, 6K1-specific polyclonal antiserum was raised against PPV 6K1 expressed in Escherichia coli as a translational fusion with the N terminus of avian troponin C and an unusual metal-binding cluster of troponin T-1. For detection of 6K1 in vivo, a pPPV-H6K1-NAT infectious clone was constructed, enabling concentration of histidine-tagged 6K1 by affinity chromatography. Affinity-purified 6K1 was detected in locally infected Nicotiana benthamiana leaves at 4, 7 and 14 days post-inoculation (d.p.i.) and, in addition, in systemically infected leaves at 14 d.p.i., 6K1 was detected exclusively as a protein of 6 kDa and no polyprotein precursors were identified with the raised anti-6K1 antiserum.
Expression of phage P4 integrase is regulated negatively by both Int and Vis
Authors: Piazzolla D. , Calì S. , Spoldi E. , Forti F. , Sala C. , Magnoni F. , Dehò G. , Ghisotti D.
Published: July 2006

Phage P4 int gene encodes the integrase responsible for phage integration into and excision from the Escherichia coli chromosome. Here, the data showing that P4 int expression is regulated in a complex manner at different levels are presented. First of all, the Pint promoter is regulated negatively by both Int and Vis, the P4 excisionase. The N-terminal portion of Int appears to be sufficient for such a negative autoregulation, suggesting that the Int N terminus is implicated in DNA binding. Second, full-length transcripts covering the entire int gene could be detected only upon P4 infection, whereas in P4 lysogens only short 5′-end covering transcripts were detectable. On the other hand, transcripts covering the 5′-end of int were also very abundant upon infection. It thus appears that premature transcription termination and/or mRNA degradation play a role in Int-negative regulation both on the basal prophage transcription and upon infection. Finally, comparison between Pint–lacZ transcriptional and translational fusions suggests that Vis regulates Int expression post-transcriptionally. The findings that Vis is also an RNA-binding protein and that Int may be translated from two different start codons have implications on possible regulation models of Int expression.
Phylogenetic relationships of seven previously unclassified viruses within the family Rhabdoviridae using partial nucleoprotein gene sequences
Authors: Kuzmin I. V. , Hughes G. J. , Rupprecht C. E.
Published: July 2006

Partial nucleoprotein (N) gene sequences of the rhabdoviruses Obodhiang (OBOV), Kotonkon (KOTV), Rochambeau (RBUV), Kern canyon (KCV), Mount Elgon bat (MEBV), Kolongo (KOLV) and Sandjimba (SJAV) were generated and their phylogenetic positions within the family Rhabdoviridae were determined. Both OBOV and KOTV were placed within the genus Ephemerovirus. RBUV was joined to the same cluster, but more distantly. MEBV and KCV were grouped into a monophyletic cluster (putative genus) with Oita virus (OITAV). These three viruses, originating from different regions of the world, were all isolated from insectivorous bats and may be specific for these mammals. African avian viruses KOLV and SJAV were joined to each other and formed another clade at the genus level. Further, they were grouped with the recently characterized rhabdovirus Tupaia virus (TRV). Although the genetic distance was great, the grouping was supported by consistent bootstrap values. This observation suggests that viruses of this group may be distributed widely in the Old World. Non-synonymous/synonymous substitution ratio estimations (d
N/d
S) using a partial N gene fragment (241 codons) for the three rhabdovirus genera revealed contrasting patterns of evolution, where d
N/d
S values follow the pattern Ephemerovirus > Vesiculovirus > Lyssavirus. The magnitude of this ratio corresponds well with the number of negatively selected codons. The accumulation of d
S appears evenly distributed along the gene fragment for all three genera. These estimations demonstrated clearly that lyssaviruses are subjected to the strongest constraints against amino acid substitutions, probably related to their particular niche and unique pathobiology.
Involvement of THH1, an Arabidopsis thaliana homologue of the TOM1 gene, in tobamovirus multiplication
Authors: Fujisaki Koki , Ravelo Gerald B. , Naito Satoshi , Ishikawa Masayuki
Published: July 2006

The TOM1 and TOM3 genes of Arabidopsis thaliana encode homologous proteins that are required for tobamovirus multiplication. Although the A. thaliana genome encodes another TOM1-like gene, THH1, the tobamovirus coat protein (CP) does not accumulate to a detectable level in the tom1 tom3 double mutant. Here, double and triple mutants of tom1, tom3 and thh1 were generated to investigate whether THH1 functions to support tobamovirus multiplication. In the tom1 thh1 double mutant, the tobamovirus CP accumulated to a level that was detectable, but lower than that in the tom1 single mutant. In tom1 tom3 double-mutant lines overexpressing THH1, the tobamovirus CP accumulated to a level similar to that observed in wild-type plants. These results suggest that THH1 supports tobamovirus multiplication, but to a lesser extent than TOM1 and TOM3. The expression level of THH1 is lower than that of TOM1 and TOM3, which might explain the smaller contribution of THH1 to tobamovirus multiplication.
Spliced mRNAs detected during the life cycle of Chicken anemia virus
Authors: Kamada Kazuya , Kuroishi Ayumu , Kamahora Toshio , Kabat Peter , Yamaguchi Shigeo , Hino Shigeo
Published: July 2006

The existence of spliced mRNA in Chicken anemia virus (CAV) was investigated, as three proteins appeared to be derived from a single 2.0 kb mRNA species. Human Torque teno virus (TTV), which displays a number of genomic similarities to CAV, is known to transcribe three mRNA species, suggesting that CAV may also have multiple mRNAs. Northern analysis of infected chicken MDCC-MSB1 cells revealed a 2.0 kb mRNA 3 h post-infection (p.i.) and additional 1.6, 1.3 and 1.2 kb bands visible at 48 and 72 h p.i. MDCC-MSB1 or COS1 cells transfected with a CAV clone showed similar results. The poly(A)+ RNA of infected cells was subjected to RT-PCR using a suite of CAV-specific primers. The major 2.0 kb RNA reacted with every primer, but the 1.3 and 1.2 kb RNAs only annealed to certain primers. The 2.0 kb mRNA had no deletions or mutations and was capable of encoding all three known CAV proteins. The 1.3 kb RNA had a splice site joining nt 1222 to nt 1814 and encoded head/tail viral protein 1 (VP1) without a frameshift. In addition, the 1.2 kb RNA possessed a splice site joining nt 994 to nt 1095 and encoded several putative, novel proteins with frameshift mutations. These splice sites conformed to the previously described GT–AG splicing rule. One further 0.8 kb RNA species appeared to be derived from a homologous recombination event. Discovery of the presence of spliced mRNA in CAV strengthens the similarity between CAV and TTV.
Genomic characterization of a novel poxvirus contributing to the decline of the red squirrel (Sciurus vulgaris) in the UK
Authors: McInnes Colin J. , Wood Ann R. , Thomas Kathryn , Sainsbury Anthony W. , Gurnell John , Dein F. Joshua , Nettleton Peter F.
Published: July 2006

The genome of a virulent squirrelpox virus (SQPV) isolate was characterized in order to determine its relationship with other poxviruses. Restriction enzyme analysis suggested a genome length of approximately 158 kb, whilst sequence analysis of the two ends of the genome indicated a G+C composition of approximately 66 %. Two contiguous stretches of 23 and 37 kb at the left-hand and right-hand ends of the genome, respectively, were sequenced allowing the identification of at least 59 genes contained therein. The partial sequence of a further 15 genes was determined by spot sequencing of restriction fragments located across the genome. Phylogenetic analysis of 15 genes conserved in all the recognized genera of the subfamily Chordopoxvirinae confirmed that the SQPV does not group within the family Parapoxvirinae, but instead partitions on its own in a separate clade of the poxviruses. Analysis of serum from British woodland rodents failed to find any evidence of SQPV infection in wood mice or bank voles, but for the first time serum samples from grey squirrels in the USA were found to contain antibody against SQPV.
Engaging in the future of e‐learning: a scenarios‐based approach
Authors: Bell Mark , Martin Graeme , Clarke Thomas
Published: July 2006

e‐Learning has been frequently heralded as a transforming influence on global education and corporate training. Despite such rhetoric, the adoption, diffusion and exploitation of e‐Learning by educational institutions and organizations have been slower than anticipated. In this paper we attempt to examine the future of e‐learning by adopting a scenario planning approach, which formed the basis of a recent major international conference held in Edinburgh, Scotland in February 2004. We set out the background of the study, the methodology used to investigate the future(s) of e‐learning and reflect on the process and outcomes of the exercise to provide some assistance for practitioners in the field. Our general conclusions are that the scenarios have been a valuable starting point to engage in a more informed discussion of how e‐learning may transform education and training markets and the ways in which people learn over the next decade.
The adoption process of corporate e‐learning in Italy
Authors: Comacchio Anna , Scapolan AnnaChiara
Published: July 2006

The diffusion process of e‐learning has been, in recent years, at the centre of several studies. These researches focused mainly on the USA case, where there has been an exponential adoption both in the public and private sectors. From this perspective the paper would give a contribution to understand the diffusion process of e‐learning in a specific country and it deals with the following questions: are there relevant consistencies in the rate and the model of adoption of e‐learning solutions in Italian companies? What are the causes of this process? Building on bandwagon theories and institutional literature, the paper analyses the antecedents of the adoption process in Italy, asking whether it is determined by the rational search for economic benefits, or is it driven by the fear of lost legitimacy or strategic advantage under institutional or competitive bandwagon pressures. The paper also looks into the solutions adopted by the Italian firms, studying their e‐learning strategies. To answer the research questions and to test the related propositions, an empirical study has been developed based on a survey, on interviews and document analysis. Since the e‐learning diffusion process in Italy is at an early stage, the research has been undertaken in two sectors, pharmaceutical and banking, where e‐learning has been adopted to a greater extent than in other sectors.
E‐learning in Scottish further and higher education
Authors: Harvey Bill , Beards David
Published: July 2006

This paper describes the process and outcomes by which an e‐learning strategy was developed for the Scottish further and higher education sectors. It summarises the context in which the Scottish Funding Councils have supported developments in Information and Communication Technology and e‐learning and identifies the main external drivers which shaped policy development. The paper presents the main conclusions of the e‐learning strategy and indicates the actions which the councils are now taking. The paper provides a useful case study of the process of strategy development at the national level and identifies key concepts which we in Scotland believe are essential components for the effective deployment of e‐learning in colleges and universities.
Management musings 8: to see ourselves as users see us …
Authors: Line Maurice B.
Published: July 2006

Libraries can be confusing institutions to users. Discusses the differences that may exist between the ways in which the staff and users perceive libraries in terms of design and layout. Suggests ways by which the staff may better understand difficulties that users face.
Project quality function deployment
Authors: Chao Lawrence P. , Ishii Kosuke
Published: July 2006

To provide an advanced product definition methodology based on quality function deployment (QFD) principles to identify minimize the risks of project failures due to failure to align with the voice of the business. The methodology was developed by reviewing current design product definition and QFD tools and then applied to a number of industry‐based design projects in academia as well as an in‐depth case study at one industry organization. The tool has been well accepted for its ease and approach in both industry and academic environments and already used to help guide project management. The methodology has only been applied to limited projects in industry and advancements and improvements are still being made. A new simple but powerful tool based on QFD principles that can be readily applied to a number of current design projects; in addition, it demonstrates how the QFD method can be expanded to non‐traditional domains and systems. This paper not only identifies current product development issues but also explores a practical and proven solution to error‐proof the design process.