bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical model linking bed and bank evolution of incisional channel created by dam removal
Authors: Cantelli A. , Wong M. , Parker G. , Paola C.
Published: July 2007

This paper is devoted to a morphodynamic model of incision into a reservoir deposit driven by partial or total removal of the associated dam. The model considers the erosional processes upstream of the position of the former dam, rather then the deposition that occurs downstream. A theory is developed to predict the evolution of both the width and depth of the incisional channel that develops as erosion progresses. The theory is implemented in a numerical model, which is tested against and verified with flume experiments on sudden, complete removal of a dam. In these experiments a channel of a given initial width is allowed to freely incise into a noncohesive reservoir deposit after sudden dam removal. These experiments show a phenomenon that we refer to as “erosional narrowing.” That is, as a channel of a given initial width rapidly incises into the deposit, it can become narrower. As the rate of incision slows, this short period of rapid narrowing is followed by a longer period of widening. In the model the incisional channel is abstracted to a trapezoidal channel with well‐defined bed and bank regions, both of which are allowed to erode. Balance between bed and bank erosion plays a key role in the morphodynamics of the channel. More specifically, rapid erosion of the bed can cause the channel to narrow even as bank erosion progresses. As the rate of bed erosion slows, bank erosion causes channel widening. This observed pattern is explained in the context of a theoretical model tested against the experiments.
Coincident occurrences of tropical individual cirrus clouds and deep convective systems derived from TRMM observations
Authors: Lin Bing , Xu Kuan‐Man , Minnis Patrick , Wielicki Bruce A. , Hu Yongxiang , Chambers Lin , Fan Tai‐Fang , Sun Wenbo
Published: July 2007

Satellite measurements of cloud properties and atmospheric radiation were used to investigate the effect of spatial and temporal scales on the coincident occurrences of tropical individual cirrus clouds (ICCs) and deep convective systems (DCSs). There is little or even negative correlation between instantaneous occurrences of ICC and DCS in small areas. When spatial and temporal domains are increased, ICCs become more dependent on DCSs due to the origination of many ICCs from DCSs and moisture supply from the DCS in the upper troposphere for the ICCs to grow, resulting in significant positive correlation between the two types of clouds. The estimated radiative feedback due to the change in tropical high cloud area coverage with sea surface temperature appears small and about −0.14 Wm−2K−1, which would not cancel out the estimated anthropogenic forcing of doubled atmospheric CO2.
Modulation of anomalous and galactic cosmic rays beyond the termination shock
Authors: Schwadron N. A. , McComas D. J.
Published: July 2007

When Voyager 1 passed through the termination shock (TS), it did not observe unfolding of the energetic particle spectrum into a single power law up to anomalous cosmic ray (ACR) energies. Instead, Voyager continued to observe the modulation of ACRs, showing that ACRs were not accelerated at the termination shock where Voyager moved through it. Here, we show how the strongly correlated modulation of anomalous and galactic cosmic rays requires that the ACR accelerator must be on field lines that connect far beyond Voyager 1 on either the distant reaches of termination shock flanks or far out in the inner heliosheath near the heliopause.
An alternative mechanism for recent volcanism on Mars
Authors: Schumacher Sandra , Breuer Doris
Published: July 2007

Images of the Martian surface indicate that volcanism is a recent process on Mars with ages of the youngest lava flows of about 2 Ma. Interestingly, these young lava flows are confined to the large, old volcanic centers of Tharsis and Elysium, which exhibit a thickened crust compared to surrounding areas. The origin of the volcanic centers but also their longstanding volcanic activity is often explained by strong mantle plumes arising from the core‐mantle boundary. However, their existence and sustainment during the last few billion years is uncertain under Martian conditions. Alternatively, the thermal insulation by the crust could cause the longstanding volcanic activity. We show that a locally thickened crust, which has a lower thermal conductivity and is enriched in radioactive heat sources in comparison to the mantle, leads to significant lateral temperature variations in the upper mantle sufficient to generate partial melt even in the present Martian mantle.
Decadal variations in the California Current upwelling cells
Authors: Chhak K. , Di Lorenzo E.
Published: July 2007

We investigate decadal variations in the three‐dimensional structure of the California Current System (CCS) upwelling cells as a potential mechanism for explaining observed ecosystem changes after the mid‐1970s. To this end, we track the origin of upwelled water masses using adjoint passive tracers during time periods corresponding to the positive and negative phase of the Pacific Decadal Oscillation (PDO) in a 55 year regional ocean model simulation of the CCS. Results show that in the PDO “cool” phase (pre mid‐1970s), the upwelling cell is deeper while during the “warm” phase (post mid‐1970s), the upwelling cell is shallower with more horizontal entrainment of surface waters from the north. These changes in the coastal upwelling cell exhibit a latitudinal non‐uniformity and may result in significant changes of the nutrient flux, which would have important impacts on the biological productivity of the coastal ocean.
Studies on glycoproteins in the human malaria parasite Plasmodium falciparum — lectin binding properties and the possible carbohydrate‐protein linkage
Authors: Ramasamy R
Published: July 2007

Several glycoproteins of the human malarial parasite Plasmodium falciparum are shown to bind to the lectins concanavalin A, wheat germ agglutinin, Rieinus communis 120 lectin and Bandeirea simplicifolia lectin. There was reduced binding of [125I]‐concanavalin A to several red blood cell glycoproteins, including the anion transport protein, in parasitised cells. The carbohydrates of parasite glycoproteins are not typical N‐linked oligosaccharides since the enzyme pepiide: N‐glyconase F fails to cleave them. In contrast, many of the parasite glycoproteins are labelled with [3H]‐myristic acid consistent with a possible linkage of carbohydrate to a membrane anchoring phospholipid.
Effects of therapy with azathioprine and prednisolone and ultraviolet irradiation on mouse skin immune function and immune cell markers
Authors: Kelly Graham E , Scheibner Adrianna , Sheil AG Ross
Published: July 2007

The effects of ultraviolet irradiation (UVI) (290–400 nm) and/or systemic immunosuppressive drug therapy (azathioprine and prednisolone) on the immunocompetence of the skin of hairless (HRA/Skh‐1) mice were investigated. Mice were studied for the density of ATPase+, la + and Thyl·2+ cells in the dorsal epidermis and contact hypersensitivity (CH) of skin to dinitrofluorobenzene (DNFB). Prednisolone therapy alone and UVI alone each reduced the densities of the three skin immune cell markers and CH responsiveness; azathioprine therapy alone had no such effects. When a suberythemal dose of UVI that Induced a moderately depressive effect on these two skin parameters was used, additional azathioprine therapy produced no further depression; additional prednisolone therapy further depressed the densities of ATPase + and Ia + cells and CH responsiveness; additional therapy with combined azathioprine and prednisolone induced profound depression of the incidences of the three immune cell markers and of CH responsiveness. These data point to interaction between azathioprine/prednisolone therapy and UVI in depressing local immune function within skin which may contribute to the increased susceptibility of the sun‐exposed skin of immunosuppressed kidney transplant recipients to infective and carcinogenic processes.
Murine Candidiasis. Pathogenesis and host responses in genetically distinct inbred mice
Authors: Ashman RB , Papadimitriou JM
Published: July 2007

The pathogenesis of Candida albicans infection was compared in three inbred strains of mice—CBA/H; C57B1/6J and BALB/c. CBA/H mice developed the most severe lesions, and also showed the weakest inflammatory responses in the popliteal lymph node after challenge with live organisms in the footpad. Nevertheless, this strain cleared Candida from the spleen more efficiently than either C57BI/6J or BALB/c mice. This apparently excludes a defect in phagocytosis as the basis for the increased susceptibility. The gene(s) determining susceptibility in CBA/H mice are located outside the major histocompatibility complex (MHC).
The follicle‐associated epithelium of the ileal Peyer's patch in ruminants is distinguished by its shedding of 50 nm particles
Authors: Landsverk Thor
Published: July 2007

Significant differences were found between the follicle‐associated epithelial cells (FAE) covering the domes of the jejunal and ileal Peyer's patches (PP) in calves. Whereas the FAE of the jejunal PP had scattered membraneous (M) cells among absorptive epithelial cells, the FAE of the ileal PP constituted a homogeneous population of cells different from both absorptive cells and M cells. The FAE of the ileal PP had short microvilli or folds, cytoplasmic vesicles and vacuoles containing acid phosphatase. Fifty nanometer membrane‐bounded panicles were found in lacunae extending from the lateral cell border These particles appeared to have been shed from the FAE. Finger‐like projections, rich in microfilaments, extended into the lacunae. M cells had short, sparse microvilli, many vesicles, few lysosomal structures, and they enfolded groups of mononuclear leucocytes. Transcytosis of macromolecular tracers occurred in both M cells and in the FAE of the ileal PP, though the uplake was greater in the latter. The 50 nm particles were also found between cells in the lymphoid tissue underneath the FAE of the ileal PP, The FAE of PP in pre‐ and post‐naial lambs from 115 days of gestation and onwards, and goal kids, showed similar structural features.
Lymphocyte migration between mutually tolerant parabiotic rats
Authors: McCullagh Peter
Published: July 2007

Lymphocytes exchanged rapidly and extensively between mutually tolerant, allogeneic rats following surgical parabiosis. Tolerated allogeneic cells persisted for an extended period in parabiotic partners after separation. A rapid exchange of cells was also observed between parabiosed syngeneic pairs of normal and allograft tolerant rats. This was accompanied by early termination of the tolerant state manifested by skin graft rejection and return of specific lymphocyte alloreactivity.
Complement activation by eggs and microfilariae of filarial parasites
Authors: Rao UR , Chandrashekar R , Subrahmanyam D
Published: July 2007

The complement of fresh normal rat serum was activated by filarial eggs and microfilariae (mf). C3 was deposited on the surface of Litomosoides carinii, Brugia pahangi, Brugia malayi and Dipetalonema viteae as seen by immunofluorescence. Intra‐uterine and in vitro‐derived mf did not bind C3. In contrast, C3 bound to the blood‐derived mf of B. pahangi and B. malayi as well as exsheathed mf of L. carinii and B. malayi. Significant consumption of complement was observed with eggs of all filarial species, as well as sheathed mf of B. pahangi, B. malayi and exsheathed mf of L. carinii and B. malayi. These experiments indicated that complement was activated by filarial parasites via the alternative pathway. The bound complement promoted neutrophil‐mediated adherence and cytotoxicity.
Induction of inflammatory responses by endotoxin in the non‐lactating ovine mammary gland
Authors: Colditz IG
Published: July 2007

In non‐lactating ewes, intramammary infusion of endotoxin provokes an intense but transient inflammatory response as assessed by mammary lavage. The variability of the method for sampling the leucocytes in mammary secretions was examined. Initial lavage with 20 ml pyrogen‐free saline recovered 83·0± 2·8 and 84·4 ± 3·0% of the total leucocyte numbers harvested by three serial washes of quiescent and inflamed glands, respectively. Lavage of glands prior to infusion of endotoxin did not affect the magnitude of the subsequent inflammatory response. Three treatments at 3·5 day intervals with the glucocorticoid, dexamethasone, which inhibits the inflammatory response to intramammary infusion of antigen in systemically immunized ewes, did not affect the inflammatory response to endotoxin. However, the variability of the inflammatory response to activated complement was greatly increased in dexamethasone‐treated ewes; this effect was attributed to the induction of lactation which results in loss of sensitivity of the gland to the inflammatory activity of activated complement. The results indicated that the macrophages and lymphocytes which are present in mammary secretions in large numbers, and dexamethasone‐sensitive lymphocytes in the gland, played a trivial role in the induction of inflammatory responses to endotoxin.
Particulate antigens may be reprocessed after initial phagocytosis for presentation to T cells in vivo
Authors: Wright MD , Wood PR , Coia G , Cheers C
Published: July 2007

Macrophages were pulsed with Listeria monocytogenes antigens by intraperitoneal injection prior to harvesting and thoroughly washing the cells. The pulsed macrophages were injected into the feet of Listeria‐immune or naive mice to elicit a delayed hypersensitivity reaction. Where soluble Listeria antigen was used, presentation by donor macrophages to host T cells required identity within the I region of the H‐2 complex. However, presentation of alcohol‐killed Listeria organisms or of a living, temperature‐sensitive mutant of Listeria was apparently not H‐2 restricted. When T cells enriched in vitro for Listeria reactivity were injected into the feet of naive mice, they reacted in an H‐2 restricted manner to antigen presented to them either by the pulsed macrophages or host cells apparently acquiring antigen from the original pulsed macrophages.
Festschrift Somatic mutations in B lymphocytes: New perspectives in tolerance research?
Authors: Nossal GJV
Published: July 2007

This paper extends the concept of clonal anergy developed in the author's laboratory. It has been shown that the primary population of B lymphocytes induced into clonal expansion and IgM antibody formation by mitogens contains many cells capable of autoantibody synthesis, but the affinity of binding to the self constituents, or indeed to foreign antigens, is low. The creation of high affinity antibody, which will still register strongly in an ELISA as an IgG molecule, demands not only the addition of lymphokines to cause isotype switching, but also intentional immunization of the donor mice to permit mutations in V region genes and selection of higher affinity B memory cells. This process appears to begin about 6 days after in vivo immunization.

It is postulated that these mutational events occur primarily in germinal centres, and that there must be mechanisms to prevent escape of cells which, by chance, mutate not to higher affinity against an immunogen, but to higher affinity against a self constituent. If such mutants were allowed to enter the long‐lived, recirculating pool of B lymphocytes, they might pose a graver threat of autoimmune disease than the low‐affinity anti‐self cells of the primary repertoire. Therefore, it is suggested that recently mutated germinal centre B cells represent a pool of ‘pre‐memory’ cells, which are immature in the sense of displaying the same kind of sensitivity to negative signalling by antigen that immature B cells from newborn spleen or adult bone marrow display. If so, then the earliest phases of memory generation represent a second window of opportunity for tolerance induction within the B lymphocyte compartment.
Isolation and characterization of glomerular macrophages in experimental glomerulonephritis
Authors: Tipping PG , Holdsworth SR
Published: July 2007

Adherent cells emigrating from glomeruli of rabbits developing anti‐glomerular basement membrane antibody induced glomerulonephritis were isolated and characterized as macrophages. Glomeruli were isolated using a sterile graded sieving technique and cultured in plastic tissue culture flasks. After varying culture times, emigrating adherent cells were harvested by ‘cold shock’ or trypsin‐versene. These cells had the morphological and functional characteristics of macrophages. They were largely mononuclear, esterase‐positive, phagocytic cells, which exhibited surface Fc receptors. A mean of 4·8±2·1 × 104 macrophages could be isolated from 2 × 104 glomeruli after 1 h in tissue culture. Greater numbers of macrophages could be isolated with further time in culture. After 72 h however, intrinsic glomerular cell contamination occurred. The majority of the cells were viable by fluorescein diacetate hydrolysis, and Trypan Blue exclusion. Further functional studies of these cells may provide some new insights into the cellular basis of macrophage‐induced glomerular injury in experimental glomerulonephritis
Role of the CD21 antigen in lymphocyte transformation by Epstein‐Barr virus
Authors: Boyd Andrew W , Fecondo John
Published: July 2007

The human CD21 membrane antigen has been shown to bind Epstein‐Barr Virus (EBV) and some binding and functional data imply a role for this interaction in the B cell tropism of EBV. In this report the technique of limit dilution analysis was used to provide evidence that B cell transformation by EBV only occurred when CD21 antigen was present and that all cells expressing CD21 were transformation‐competent. The rate of transformation varied, being increased if B cells were activated by an additional B cell mitogen, and being dependent on, although not strictly proportional to, the intensity of CD21 expression. The possibility that EBV might enter by other means was examined by selectively deleting CD21 antigen from the cell surface. This was accompanied by a profound decrease in the transformation frequency. It is concluded that CD21 antigen is necessary for EBV transformation and that CD21 expression is the major limiting factor in these events.
Auto‐anti‐idiotypic antibodies in mice hyperimmunized with a chemically induced bladder carcinoma
Authors: Greer Judith M , Halliday WJ
Published: July 2007

Purified immunoglobulin from the serum of mice hyperimmunized with syngeneic tumour cells was compared with a monoclonal anti‐idiotope antibody, obtained by immunizing mice with antibody to the same tumour. Both the immunoglobulin and the monoclonal antibody were specifically immunogenic in syngeneic (BALB/c) mice as tested by in vitro and in vivo assays of cell‐mediated immunity. In both cases the reactivity was absent in immunoglobulin heavy chain gene complex‐1 ‐(Igh) allotype congenic (CB.20) mice, indicating Igh‐restriction of immunogenicity. The active material in hyperimmune serum thus has the properties of auto‐anti‐idiotypic antibody, complementary to T cell idiotopes.
B lymphocyte/carcinoma antigen (BLCa): Functional study in B cells
Authors: Zola H , Barclay S , Furness V , Macardle PJ , Neoh SH , Bradley J
Published: July 2007

BLCa is an antigen expressed on the surface of B lymphocytes and certain carcinomas. In this study we have demonstrated that BLCa is distinct from known B cell antigens classified by ‘clusters of differentiation’ (CD). In particular, the monoclonal antibody MA6, which identifies BLCa, can be distinguished from antibodies of the CDw40 group, which detect an antigen of similar molecular weight expressed also on B cells and certain carcinomas. The expression of BLCa on B cells was measured as tonsil B cells were activated (by anti‐Ig and interleukin‐4 (IL‐4)), induced to proliferate (by low molecular weight B Cell Growth Factor (LMW‐BCGF). and induced to differentiate (by B Cell Differentiation Factor, BCDF). Expression of BLCa increased in response to LMW‐BCGF, The effect of inclusion of MA6 antibody in cultures with the B cell stimuli was also investigated. MA6 showed an anti‐proliferative effect which was antibody‐dose dependent, but did not otherwise inhibit or co‐operate with anti‐Ig, IL‐4, LMW‐BCGF or BCDF.
Evidence that Thy‐1 and Ly‐5 (T‐200) antigens interact with sulphated carbohydrates
Authors: Parish Christopher R , Hogarth P Mark , McKenzie Ian FC
Published: July 2007

Recent studies have demonstrated that lymphocytes express an array of ceil surface receptors for sulphated polysaccharides (SP). Experiments were undertaken to determine the binding characteristics of these receptors and establish whether any known lymphocyte cell surface antigens interact with sulphated carbohydrates. It was found that murine thymocytes lack receptors for chondroitin‐4‐sulphate but express saturable, high affinity binding sites for heparin, fucoidan and dextran sulphate, with an apparent affinity constant range of 0·03–2·6 ×10−9 mol/l. Binding inhibition experiments revealed one class of binding sites on murine thymocytes that is shared by heparin, fucoidan and dextran sulphate and another class of sites that is dextran sulphate‐specific.

The cell surface receptors for the SP were affinity‐purified by applying detergent lysates of 125I‐labelled thymocyte membranes to SP‐coupled solid supports. It was found that the Thy‐1 and Ly‐5 (T‐200 or leucocyte common antigen) molecules of murine thymocytes bind to sulphated carbohydrates, although the two molecules differed substantially in their reactivity with the four different SP tested. Furthermore, only subpopulations of the Thy‐1 and Ly‐5 molecules interacted with sulphated sugars. Four additional sulphated carbohydrate‐binding molecules were also detected. It is suggested that the SP‐binding molecules are involved in the interaction of lymphocytes with glycosaminoglycans on other cells and in the interstitial space.
Augmentation of mitogen‐induced thymocyte proliferation by bacterial products is mediated by an Mr 36 000 monokine
Authors: Hedberg Nancy , Hunter Neil
Published: July 2007

The addition of picogram quantities of bacterial products to rat thymic cells in culture produced a doubling of the proliferative response to suboptimal levels of Concanavalin‐A (Con‐A). This effect was prevented by the depletion of adherent cells which comprised < 0·1% of the total population. The response was restored by the addition of supernatants from peritoneal macrophages which had been stimulated 2 h previously with lipopolysaccharide. Treatment of these supernatants with phenylglyoxal, an inhibitor of interleukin‐1 (IL‐1), did not prevent the stimulatory effect. Augmentation of the thymocyte proliferative response could also be achieved by the addition of a partially purified monokine of relative molecular weight (Mr) 36 000 which is biochemically and functionally distinct from IL‐1 and by a monoclonal antibody which binds to a common determinant on the Ia molecule. Fractionation of the thymic cells on a density gradient yielded a buoyant population which accounted for the majority of the proliferative activity and a dense fraction which was poorly responsive to the mitogen. The addition of the monokine to this latter fraction produced a significant increase in proliferation in response to Con‐A. It is proposed that in the thymus, bacterial products stimulate thymic macrophages to release the Mr 36 000 monokine which in turn stimulates the thymic epithelial cells to release products which promote the survival and maturation of immature thymocytes. This work has implications for the regulation of thymocyte maturation.
Type‐specific monoclonal antibodies produced to proteins of Murray Valley encephalitis virus
Authors: Hall Roy A , Burgess Graham W , Kay Brian H
Published: July 2007

Two monoclonal antibodies have been produced to the flavivirus, Murray Valley encephalitis (MVE). Immunofluorescent antibody and ELISA tests revealed that one antibody was specific for MVE while the other cross‐reacted weakly with Alfuy and Kunjin viruses. These antibodies have neither haemagglutination inhibition nor neutralising activity. One of the monoclonal antibodies reacted with the envelope glycoprotein (E) and a 45,000 MW protein, while the other reacted with a protein of 23,000 daltons. Competitive binding assays confirmed that these antibodies reacted with unrelated epitopes.
Tolerance to aggregated human IgG but not ovalbumin can be induced by concurrent administration of depleting or non‐depleting anti‐L3T4 monoclonal antibodies
Authors: Charlton Brett , Mandel Thomas E
Published: July 2007

Tolerance to soluble antigens has previously been shown to occur in mice if anti‐L3T4 monoclonal antibody (MoAb) is administered al the time of antigen exposure. The process of tolerance induction may require the depletion of L3T4+ cells or it may be due to down‐regulation or negative signaling of L3T4+ cells. We compared the effects of L3T4+ cell depletion and L3T4 antigen blockade at the time of primary antigen challenge on long‐term humoral responses. Anti‐L3T4 MoAb GK1·5 (IgG2b) and H129·19 (IgG2a) were used to deplete or block, respectively. L3T4+ cells.

Following a short course of MoAb and antigen challenge with both aggregated human IgG (ag‐HGG) and ovalbumin (OVA) in each mouse, primary response titres to each antigen in both MoAb treated groups were ∼1:102 compared with ∼1:105 in control mice. Repeated antigen challenge significantly increased the anti‐OVA titre in both MoAb treated groups and by 150 days they were similar to controls. However, anti‐HGG titres did not increase significantly in either of the MoAb treated groups.

Thus either depletion of peripheral L3T4+ cells, or blockade of the L3T4 antigen without depletion of peripheral L3T4+ cells, can invoke a state of long‐term antigen‐specific tolerance to some antigens. Why the effect is restricted to particular antigens, and the exact mechanisms of tolerance induction remain to be determined.
Excretory‐secretory antigens from adult Nematospiroides dubius
Authors: Monroy FG , Adams JH , East IJ , Dobson C
Published: July 2007

Adult Nematospiroides dubius excretory‐secretory (ES) products were collected from worms cultured in vitro, radiolabelled and separated by sodium dodecyl polyacrylamide gel electrophoresis (SDS‐PAGE). The components were characterized and assessed for molecular weight (MW) after autoradiography and gel staining, for antigenicity in immunoblots, for sensitivity to protease enzymes, and for carbohydrate content. ES contained at least 18 denatured components from MW <20 000 to >200 000. At least one of the surface proteins of adults was found with the ES antigens recovered when adults were cultured in vitro. Molecules with MW 200 000, 78 000 and 60 000 were glycoproteins and reacted with immune mouse serum in Western blots. The dominant ES, MW 60 000 component stained with periodic acid‐Schiff (PAS), bound lectins with affinity for D‐mannose, and was resistant to peptic and tryptic but not V8 protease digestion.
Eicosanoids produced during interactions between Pseudomonas aeruginosa and alveolar macrophages are species‐dependent
Authors: Sorrell TC , Rochester CP , Breen FN , Müller M
Published: July 2007

Eicosanoid production during phagocytosis of pyogenic bacteria by rabbit alveolar macrophages was studied as a model of early events in the pathogenesis of pneumonia. Adherent alveolar macrophages. prelabelled with [3HJ]‐arachidonic acid (AA), were incubated with live, opsonized Staphylococcus aureus or Pseudomonas aeruginosa (bacteria: macrophage ratio of 50:1) at 37°C for 90 min. Supernatant eicosanoids were extracted and separated by reverse phase high performance liquid chromatography (RP‐HPLC). While the amounts of labelled PGF2, TXB2, and PGD2 produced in response to the two organisms were equal, the amount of PGF2α elicited by S. aureus amounted to three times that released during macrophage challenge with P. aeruginosa. Overall, preferential release of cyclooxygenase products occurred during phagocytosis of S. aureus. In contrast, eicosanoids identified presumptively as oxygenated metabolites of AA predominated in cultures challenged with opsonized P. aeruginosa. Live, non‐opsonized P. aeruginosa elicited the same profile of eicosanoids, but in reduced amounts.

Inhibitor studies indicated that these AA derivatives were not synthesized via the macrophage lipoxygenase pathway. Their production was dependent on the viability of P. aeruginosa. Macrophages challenged with opsonized, heat‐killed P. aeruginosa resulted in production of an eicosanoid profile similar to that elicited by S. aureus.

Secondary metabolism by P. aeruginosa of eicosanoids released from the macrophage did not contribute to the unique profile produced during the interaction of this organism with labeled macrophages.

Our data indicate that during binding to macrophages, the primary human pathogen, P. aeruginosa, specifically modulates the profile of eicosanoids produced. This effect on inflammatory mediators may be of biological significance in the pathogenesis of pneumonia.
Circulating human T and B lymphocytes express the p55 interleukin‐2 receptor molecule (TAC, CD25)
Authors: Zola H , Mantzioris BX , Webster J , Kette FE
Published: July 2007

Using a highly sensitive immunofluorescence procedure 15‐45% of blood lymphocytes from normal human donors can be shown lo react with anti‐TAC (CD25) monoclonal antibodies. The standard procedure for indirect immunofluorescencc docs not allow the detection of these CD25‐positive cells. Ten healthy adults were tested, and all showed a population of positive cells. Three donors have been tested more than once, and have given consistent results. Three different CD25 antibodies were used, again with consistent results. Double‐marker studies showed that the positive cells included B cells, as well as CD4‐bearing and CD8‐bearing T cells.
The murine cellular immune response to adenovirus type 5
Authors: Müllbacher A , Bellelt AJD , Hla RT
Published: July 2007

We have characterized the cellular immune response to human adenovirus 5 (Ad‐5) in mice, as a basis for future study of responses to foreign antigens in recombinant adenoviruses. Primary in vivo lytic effector cells contained both virus immune cytolytic T (Tc) cells and natural killer cells. The Tc effectors could be boosted in vitro to give a secondary Tc cell response. The Tc cell response to Ad‐5 was major histocompatibility complex (MHC) restricted, and in CBA/H (H‐2k) mice mapped to the K end of MHC. Kinetic experiments suggested the Tc cell response was directed against early rather than late viral proteins. Experiments with viral mutants showed that the main responses were to the E1A and E1B proteins, with some involvement of E2. Expression of E3 and E4 in infected targets was not required, in fact lysis of target cells infected by viruses with a deletion in E3 was augmented.
Effect of donor specific transfusion (DST) is restricted to the rat combination used and closely related with alloantibody in heart transplantation
Authors: Hamano K , Ohmi M , Esato K , Fukumoto T
Published: July 2007

The effect of donor specific transfusion (DST) in several donor‐recipient combinations was examined using the rat heart transplantation model. In some donor‐recipient combinations such as LEW to DA, LEW to ACI, LEW to PVG and PVG to DA, DST pretreatment could induce permanent graft survival (>100 days). But in DA to LEW, ACI to LEW, LEW to BN, BN to LEW, PVG to LEW and BN to DA combinations DST pretreatment had no effect on graft survival. The effect of pre‐immunization with several DA antigens (heart, liver, lymph node cells and red blood cells) was examined using the DA to LEW combination in which DST pretreatment was not effective. In no case was permanent graft survival obtained. Alloantibody levels (anti‐class I and anti‐class I + II, respectively) were analysed at the time of heart transplantation and in the post‐transplantation period. The anti‐class I antibody levels were low or not detected in rats with surviving grafts, but in the rats which failed to have the prolonged graft survival, anti‐class I antibody levels were high. This study showed that the effect of DST was restricted to particular donor‐recipient rat combination in the heart transplantation model.
Enhancement of u.v.‐induced skin carcinogenesis in the hairless mouse by inoculation with cell‐free extracts of skin tumours
Authors: Reeve VE , Greenoak GE , Canfield PJ , Boehm‐Wilcox C , Tilbrook PA , Kulski JK , Gallagher CH
Published: July 2007

The presence of papillomaviral‐like DNA has been described in ultraviolet light‐induced tumours in the skin of the hairless mouse (14). Here we describe the effects of the inoculation of cell‐free extracts of ultraviolet light‐induced tumours into the scarified skin of normal hairless mice, prior to exposure of the mice to a cumulative carcinogenic dose of ultraviolet light. Extracts from papillomas or squamous cell carcinomas enhanced the susceptibility of the inoculated mice to ultraviolet light‐induced tumorigenesis, if the extracts contained papillomaviral DNA sequences detected by cross‐hybridization with Mastomys natalensis papillomaviral DNA. The recipient mice developed a greater tumour incidence, tumour yield, tumour diameter and degree of malignancy.
T lymphocytes in infectious mononucleosis; Effect of IL‐2 on the outgrowth of Epstein‐Barr virus‐infected cells
Authors: Misko IS , Burrows SR , Schmidt C , Bishop CJ , Ryan JM , Staples JA , Moss DJ
Published: July 2007

The addition of interleukin‐2 (IL‐2) to lymphocyte cultures from acute infectious mononucleosis (IM) donors dramatically increased the incidence of regression in such cultures and resulted in the emergence of an IL‐2 dependent, CD3 Epstein‐Barr virus nuclear antigen (EBNA)‐negative cell population. Corresponding cultures seeded in the absence of IL‐2 rarely regressed and were quickly dominated by IL‐2 independent, CD3‐negative, EBNA‐positive cells. Lymphocyte cultures from Epstein‐Barr virus (EBV) seropositive donors showed enhanced regression in the presence of IL‐2 but failed to regress after the removal of the E‐rosetting population. Cultures from EBV‐seronegative donors showed no evidence of regression in the presence or absence of IL‐2. E‐rosetting cells isolated from cultures from acute IM donors that had been cultured in the presence of IL‐2 lysed autologous and allogeneic lymphoblastoid cell lines.
The p24 leucocyte membrane antigen: Modulation associated with lymphocyte activation and differentiation
Authors: Zola H , Furness V , Barclay S , Zowtyj H , Smith M , Melo JV , Neoh SH , Bradley J
Published: July 2007

Monoclonal antibodies of the CD9 cluster recognize a 24 kD protein (p24) found on platelets and endothelium, and expressed by lymphocytes at restricted stages of maturation and activation. In this study, we explore the possibility that p24 is involved in the response of lymphocytes to signals delivered by lymphokines. p24 is expressed only very weakly by resting B lymphocytes. We found no increase in expression when cells were activated with anti‐immunoglobulin together with interleukin‐4, or induced to proliferate by low‐molecular weight B cell growth factor (LMW‐BCGF). Culture of activated B cells with B cell differentiation factor was associated with an increased mean expression of p24. In cells from a patient with chronic lymphocytie leukaemia (CLL), culture with LMW‐BCGF up‐regulated p24 expression. Resting T cells (p24‐negative) were induced to express p24 strongly when activated with antibody against CD3. CD9 antibody did not modulate B or T cell responses to activation stimuli. The results suggest that the p24 molecule is not involved in the primary interaction of cells with lymphokine, but rather may be involved in a secondary reaction, such as ion flux, which follows as a consequence of the action of lymphokines on cells.
Neonates have a spinal alpha receptor too, as do adults
Authors: Yaksh T L
Published: July 2007

British Journal of Pharmacology (2007) 151, 1139–1140; doi:10.1038/sj.bjp.0707291
Meta‐analysis of cannabinoid ligand binding affinity and receptor distribution: interspecies differences
Authors: McPartland J M , Glass M , Pertwee R G
Published: July 2007

A meta‐analysis, unlike a literature review, synthesizes previous studies into new results. Pooled data from 211 studies measured ligand binding affinities at human (Hs) or rat (Rn) cannabinoid receptors CB1and CB2. Cochrane methods were modified for this non‐clinical analysis. Meta‐regression detected data heterogeneity arising from methodological factors: use of sectioned tissues, lack of PMSF and choice of radioligand. Native brain tissues exhibited greater affinity (lower nM) than transfected cells, but the trend fell short of significance, as did the trend between centrifugation and filtration methods. Correcting for heterogeneity, mean Kivalues for Δ9‐tetrahydrocannabinol differed significantly betweenHsCB1andRnCB1(25.1 and 42.6 nM, respectively) but not betweenHsCB1andHsCB2(25.1 and 35.2). Mean Kdvalues forHsCB1,RnCB1andHsCB2of CP55,940 (2.5, 0.98, 0.92) and WIN55,212‐2 (16.7, 2.4, 3.7) differed betweenHsCB1andRnCB1and betweenHsCB1andHsCB2. SR141716A differed betweenHsCB1andRnCB1(2.9 and 1.0 nM). Anandamide atHsCB1,RnCB1andHsCB2(239.2, 87.7, 439.5) fell short of statistical differences due to heterogeneity. We consider these Kdand Kivalues to be the most valid estimates in the literature. Sensitivity analyses did not support the numerical validity of cannabidiol, cannabinol, 2‐arachidonoyl glycerol and all ligands atRnCB2. Aggregate rank order analysis of CB1distribution in the brain (pooled from 119 autoradiographic, immunohistochemical andin situhybridization studies) showed denserHsCB1expression in cognitive regions (cerebral cortex) compared toRnCB1, which was relatively richer in movement‐associated areas (cerebellum, caudate‐putamen). Implications of interspecies differences are discussed.

British Journal of Pharmacology(2007)152, 583–593; doi:10.1038/sj.bjp.0707399; published online 16 July 2007
Phylogenetic Background of Orange Lily (Lilium bulbiferum s.l.) Cultivars from a Genetically Isolated Environment
Authors: Pelkonen V.‐P. , Niittyvuopio A. , Pirttilä A. M. , Laine K. , Hohtola A.
Published: July 2007

Abstract: Domesticated Orange lily (Lilium bulbiferum s.l.) cultivars do not typically produce seeds, and Orange lily is not native to Finland. Therefore, back crossing of the cultivars with wild species has not been possible. Genetic variability and genuineness of eight Finnish traditionally‐grown Orange lily cultivars was studied. RAPD patterns were compared between the cultivars and genuine Orange lily (Lilium bulbiferum L.), and a related Dauricum group. The results showed partition of tested genotypes into four groups, L. canadense as the outgroup. The cultivars were divided into two subgroups where the trait to form bulbils was characteristic to subgroup I. The cultivated strains differed from each other as much as from the seedling strains, but were genetically closer to genuine Orange lily than the Dauricum group. This indicates that the cultivars are genuine forms of Orange lily species. The special morphological features of the cultivars have likely been formed during centuries‐long genetic isolation from natural populations.
The role of resistivity on line-tied kink modes in cylindrical geometry
Authors: Delzanno G. L. , Evstatiev E. G. , Finn J. M.
Published: July 2007

An investigation of the effect of resistivity on linear line-tied kink modes is presented in cylindrical geometry. A region near marginal stability, where the line-tied system is stable in ideal magnetohydrodynamics but unstable with resistivity, is shown. In this region, the growth rate is found to be proportional to resistivity. There is no signature of the tearing-like scaling, which occurs in the corresponding system with periodic boundary conditions, or of the formation of boundary layers near the end plates. Instead, the resistive scaling is due to global resistivity, leading to imperfect line-tying. This feature is common to equilibrium pitch profiles that increase or decrease monotonically with radius and is not influenced by viscosity.
Stability of nonlinear one-dimensional laser pulse solitons in a plasma
Authors: Saxena Vikrant , Das Amita , Sengupta Sudip , Kaw Predhiman , Sen Abhijit
Published: July 2007

In a recent one-dimensional numerical fluid simulation study [Saxena et al., Phys. Plasmas 13, 032309 (2006)], it was found that an instability is associated with a special class of one-dimensional nonlinear solutions for modulated light pulses coupled to electron plasma waves in a relativistic cold plasma model. It is shown here that the instability can be understood on the basis of the stimulated Raman scattering phenomenon and the occurrence of density bursts in the trailing edge of the modulated structures are a manifestation of an explosive instability arising from a nonlinear phase mixing mechanism.
Surface tension of the Widom-Rowlinson model
Authors: de Miguel E. , Almarza N. G. , Jackson G.
Published: July 2007

We consider the computation of the surface tension of the fluid-fluid interface for the Widom-Rowlinson [J. Chem. Phys. 52, 1670 (1970)] binary mixture from direct simulation of the inhomogeneous system. We make use of the standard mechanical route, in which the surface tension follows from the computation of the normal and tangential components of the pressure tensor of the system. In addition to the usual approach, which involves simulations of the inhomogeneous system in the canonical ensemble, we also consider the computation of the surface tension in an ensemble where the pressure perpendicular (normal) to the planar interface is kept fixed. Both approaches are seen to provide consistent values of the interfacial tension. The issue of the system-size dependence of the surface tension is addressed. In addition, simulations of the fluid-fluid coexistence properties of the mixture are performed in the semigrand canonical ensemble. Our results are compared with existing data of the Widom-Rowlinson mixture and are also examined in the light of the vapor-liquid equilibrium of the thermodynamically equivalent one-component penetrable sphere model.
Exchange parameters from approximate self-interaction correction scheme
Authors: Akande A. , Sanvito S.
Published: July 2007

The approximate atomic self-interaction correction (ASIC) method to density functional theory is put to the test by calculating the exchange interaction for a number of prototypical materials, critical to local exchange and correlation functionals. ASIC total energy calculations are mapped onto a Heisenberg pairwise interaction and the exchange constants J are compared to those obtained with other methods. In general the ASIC scheme drastically improves the band structure, which for almost all the cases investigated resemble closely available photoemission data. In contrast the results for the exchange parameters are less satisfactory. Although ASIC performs reasonably well for systems where the magnetism originates from half-filled bands, it suffers from similar problems than those of local density approximation for other situations. In particular, the exchange constants are still overestimated. This reflects a subtle interplay between exchange and correlation energy, not captured by the ASIC.
Resolved: Electronic states underneath broad absorptions
Authors: Cardoza Job D. , Weber Peter M.
Published: July 2007

The far UV absorption spectra of many polyatomic molecules show featureless, broad bands, even though the lifetimes of the underlying electronic states can be long enough to render the states observable. Using photoionization from Rydberg states we measure electron binding energies, thereby referencing the electronic spectra to the adiabatic ionization energy. In trimethylamine, we find that the 3s, the 3px,y, and the 3pz Rydberg states have binding energies of 3.087, 2.251, and 2.204eV, respectively. Vibrational motions excited while preparing the Rydberg states do not interfere with the spectra.
Polymer depletion profiles around nonspherical colloidal particles
Authors: Eisenriegler E. , Bringer A.
Published: July 2007

We study the effect of chain self-avoidance on the polymer density profiles that are induced by a single colloidal particle of nonspherical shape such as an ellipsoid, a dumbbell, or a lens in a solution of nonadsorbing polymers. For colloid sizes σ much smaller than the size Rx of the polymers, we observe a pronounced difference between ideal and self-avoiding chains. In the case of ideal polymers, the surfaces of constant density always have the same character as the surface of the particle, e.g., are oblate for an oblate ellipsoid. In the self-avoiding case, however, the character changes with increasing distance r from the particle, and an oblate particle induces prolate surfaces of constant density if σ⪡r⪡Rx. For σ⪡r,Rx, the isotropic and anisotropic contributions to the densities factor into a dependence on the particle size and shape and a dependence on r,Rx. The latter is determined by distance distributions within a chain in the absence of the particle. For self-avoiding polymers in two spatial dimensions, exact density profiles are derived for σ,r⪡Rx, which explicitly show the above-mentioned change of the contours of constant density.
Optical bistability in Er-Yb codoped phosphate glass microspheres at room temperature
Authors: Ward Jonathan M. , O’Shea Danny G. , Shortt Brian J. , Chormaic Síle Nic
Published: July 2007

We experimentally demonstrate optical bistability in Er3+-Yb3+ phosphate glass microspheres at 295 K. Bistability is associated with both Er3+ fluorescence and lasing behavior, and chromatic switching. The chromatic switching results from an intrinsic mechanism exploiting the thermal coupling of closely spaced energy levels, and occurs simultaneously with the intensity switching. A contrast ratio of 2.8 has been obtained for chromatic switching. The intensity switching shows ratios of 21 for 520 nm and 11 for 660 nm fluorescence emissions, and 11 for IR lasing at 1.5 μm. Concurrent with these observations, we investigate a temperature-dependent absorption of pump power, which exhibits bistable behavior. The influences of the host matrix on lasing and fluorescence mechanisms are highlighted.
High-resolution Brillouin spectroscopy with angular dispersion-type Fabry-Perot interferometer and its application to a quartz crystal
Authors: Ike Y. , Tsukada S. , Kojima S.
Published: July 2007

Although the multichannel Brillouin spectroscopy with an angular dispersion-type Fabry-Perot interferometer (ADFPI) becomes a powerful tool for quick measurements, its resolution and contrast are not enough for the study of single crystals. A highly sensitive multichannel detector enables the ADFPI to use a solid etalon with high reflectivity (99.5%); hence, the high resolution and the high contrast of a spectrum are achieved. The finesse, the inverse of the resolution, reaches 100 with a 10mm diameter of aperture size. The highest finesse of 140 is obtained by using a smaller diameter of 2mm. The accuracy is examined by the measurement of a quartz crystal. The improvement in the resolution and contrast enables investigations of weak attenuation in a quartz crystal. The elastic anomaly of the α-β transition of a quartz crystal is clearly observed both in sound velocity and attenuation. From the elastic constant c11, the critical parameter K=0.76 is determined.
SiGe double barrier resonant tunneling diodes on bulk SiGe substrates with high peak-to-valley current ratio
Authors: Tsujino S. , Usami N. , Weber A. , Mussler G. , Shushunova V. , Grützmacher D. , Azuma Y. , Nakajima K.
Published: July 2007

The authors present high-quality p-type SiGe double barrier resonant tunneling diodes obtained from bulk SiGe substrates grown by the multicomponent zone-melting method and by the layer deposition with molecular beam epitaxy. Devices exhibit a high peak-to-valley current ratio up to 8.8 at 4.2K and a negative differential resistance up to 340K. The result demonstrates that bulk SiGe substrates have a clear potential impact for fabricating high-performance SiGe heterostructure devices based on quantum transport.