bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigen‐Ia interaction and the proteolytic processing of antigen: the structure of the antigen determines its restriction to the A or E molecule of the major histocompatibility complex
Authors: Puri Joseph , Lonai Peter , Friedman Varda
Published: February 2007

The effect of a protease inhibitor, leupeptin, on the presentation of hen egg lysozyme (HEL) to cloned T cells was investigated. We found that leupeptin‐sensitive thiol proteases are apparently less involved when HEL is presented by the I‐Ad molecule, than when it is presented by the I‐Ed molecule. This selectivity was more of a function of the antigen than that of the Ia molecule because presentation of denatured or fragmented HEL was not sensitive to leupeptin whereas antigen presentation to a number of I‐A‐restricted T cell clones specific to other antigens was sensitive to leupeptin. These data demonstrate that the particular combination of major histocompatibility complex/nominal antigen recognized by a certain T cell clone may require processing of the antigen molecule through a certain group of proteases and that other combinations are independent of that particular processing pathway. Furthermore, there is a preference for a certain type of processing depending on the Ia molecule involved.
Possible T4‐HLA class II interaction as an essential event in antigen‐specific helper T lymphocytedependent B cell activation
Authors: Fischer Alain , Sterkers Ghislaine , Charron Dominique , Durandy Anne
Published: February 2007

We have previously shown that the interaction between influenza virus‐specific helper T lymphocytes and B lymphocytes is HLA class II restricted (Fischer, A. et al., Eur. J. Immunol. 1985. 15: 620). In the present study, we used a panel of antibodies specific for the T4 and HLA‐DR molecules to investigate the role of both structures in T‐B lymphocyte interaction. Several anti‐T4 monoclonal antibodies were shown to block the in vitro antibody production to A/Bangkok influenza virus while they were unable to inhibit the A/Bangkok‐induced proliferation of specific helper T cell clones. Some anti‐HLA‐DR monoclonal antibodies inhibited the antibody production to A/Bangkok, the target of the inhibition being either monocytes or B lymphocytes. The incubation of helper T cell clones with an infra‐inhibitory concentration of anti‐ T4 antibody and of B lymphocytes with an infra‐inhibitory concentration of anti‐ HLA‐DR antibody resulted in a mutual enhancement of inhibition. Such synergistic interactions were not observed using combinations of (a) anti‐T4 and anti‐B membrane structures such as p35 or LFA‐1 or (b) anti‐HLA‐DR and anti‐T membrane structures such as T11 or LFA‐1. First, these results indicate that the T4 molecule plays an essential role in T‐B cell interaction even when it is not absolutely required for T cell proliferation. Second, they strongly suggest that the T4 molecule directly interacts with HLA‐DR at the B cell surface. Whether such interaction is required to enhance the stability of T3/T cell receptor‐antigen plus HLA class II association or whether T4‐HLA‐DR may transduce a signal towards B lymphocytes that is required in B cell activation remains unknown.
Impaired humoral immune response in complement C3‐deficient guinea pigs: absence of secondary antibody response
Authors: Böttger Erik C. , Metzger Susanne , Bitter‐Suermann Dieter , Stevenson George , Kleindienst Sabine , Burger Reinhard
Published: February 2007

A recently described egenetically controlled C3 deficiency (C3D) in guinea pigs (GP) provided a unique model for studying the role of C3 in the afferent limb of the humoral immune response in a direct manner. These C3D animals, which have only 5–7% of normal serum C3 level, were immunized with the bacteriophage ϕX174, a T cell‐dependent antigen, followed by a booster injection after 4 weeks (1.5 × 109plaque‐forming units/kg). The formation of IgM and IgG antibody in the course of the primary and secondary response was determined and compared with a control group of inbred strain 2 GP. The C3D animals showed a markedly diminished antibody response to this antigen. Amplification of the antibody titer as well as regular isotype switching from IgM to IgG was absent in the secondary response. Increasing the amount of antigen to a high dose (1 × 1010 plaque‐forming units/kg) led to a normalization of the antibody response. The impairment in antibody formation resembles closely the impaired antibody response in C4‐deficient or C2‐deficient GP, which both have a block in activation of C3 via the classical pathway. However, in contrast to C4D GP or C2D GP the C3D GP do not exhibit serological characteristics of immune complex disease. They have normal levels of total serum IgM, of IgM anti‐ 2,4‐dinitrophenyl antibodies and of IgM rheumatoid factors.
Generation of bovine cytotoxic cell lines, specific for cells infected with the protozoan parasite Theileria parva and restricted by products of the major histocompatibility complex
Authors: Goddeeris Bruno M. , Ivan Morrison W. , Teale Alan J.
Published: February 2007

Cytotoxic cell lines specific for cells infected with the protozoan parasite Theileria parva were generated in vitro by repeated stimulation of peripheral blood mononuclear cells (PBMC) from immune animals with autologous parasitized cells from continuously growing cell lines. In PBMC of 5/7 immune animals tested, maximal levels of killing (80–100%) were obtained at effector to target ratios of 10/1 following 3 to 5 stimulations. No killing of uninfected lymphoblasts was observed. Cytotoxic activity was contained in the BoT4− lymphocyte population. The results of analyses of cytotoxicity on panels of target cells of diverse major histocompatibility (MHC) phenotypes indicated that the effectors were restricted by class I MHC antigens. Only autologous targets and allogenic targets sharing one or other bovine lymphocyte antigen A locus‐encoded specificity with the cytotoxic cell line were killed. In addition, two of the three cytotoxic cell lines, when tested on targets infected with different parasite stocks, exhibited a high degree of specificity for the stock used for immunization and stimulation of the cultures. The capacity to generate highly cytotoxic, MHC‐restricted effectors from peripheral blood was dependent on the immune status of the donor animals. This was confirmed by comparing cytotoxicity generated from the same animal before and after immunization using the same autologous infected cell line as a stimulator. These results indicate that these effector cells are analogous to the cytotoxic cells detected in vivo in cattle undergoing immunization or challenge with T. parva.
Suppression of the local graft‐vs.‐host reaction in ratsby treatment with a monoclonal antibody specific for the interleukin 2 receptor
Authors: Volk Hans‐Dieter , Brocke Stefan , Osawa Hisao , Diamantstein Tibor
Published: February 2007

Local graft‐vs.‐host reaction (GVHR) was induced in rats by injecting parental cells into young F1 recipients. As a consequence of antigenic stimulation in the course of developing GVHR in the responding lymph nodes, the number of interleukin 2 receptor (IL2R)‐bearing T cells increased from less than 1% up to 10% of the total population. The IL2R‐bearing cells were located mainly in the T cell areas of there active lymph nodes. As assessed by the determination of the GVHR indices, treatment of the recipients with anti‐T‐helper subset‐specific mAb (W3/25) or with anti IL2R mAb (ART‐18) inhibited the GVHR. In parallel, the number of IL2R‐bearingcells was reduced to the normal levels. W3/25 mAb treatment changed the helper/suppressor subset ratio and reduced the number of circulating lymphocytes in the peripheral blood. In contrast, ART‐18 mAb treatment did not induce any detectable changes in the subset distribution and it did not affect the number of circulating lymphocytes. The results demonstrate the key role that the IL 2R‐positive cells play in the proliferative phase of acute GVHR, and favor the use of anti‐IL2R mAb as selective immunosuppressive agents.
Effects of mycoplasma infection on Fc receptors for IgE of rat basophilic leukemia cells
Authors: Chan Bosco M. C. , McNeill Karol , Berczi Istvan , Froese Arnold
Published: February 2007

Earlier studies from this laboratory had shown that rat basophilic leukemia cells carry two major receptors for IgE, named R and H, and a third minor receptor, designated 71K. It is now apparent that 71K is induced by the action of Mycoplama hyorhinis, a common contaminant of tissue cultures. This induction is reversible. Decontamination either in in vitro or in vivo leads to a disappearance of 71K and re‐infection causes its reappearance. The 71K receptor appears to be induced by the action of the mycoplasma on a surface molecule, most likely R, present on the cells at the time of infection. When receptors are occupied by IgE, 71K induction is inhibited. Other effects of mycoplasma infection include the significant reduction in the expression of transferrin receptors and increased histamine content of infected cells.
A monoclonal antibody reacting with a membrane determinant expressed on activated chicken T lymphocytes
Authors: Hála Karel , Schauenstein Konrad , Neu Nikolaus , Krömer Guido , Wolf Hugo , Böck Günther , Wick Georg
Published: February 2007

A monoclonal antibody (INN‐CH‐16) was prepared which reacts with a cell surface antigen termed chicken activated T lymphocyte antigen. This antigen is expressed on antigen‐ or mitogen‐activated T lymphocytes and is not present on nonstimulated lymphocytes. It has an apparent molecular mass of 48‐50 kDa under reducing conditions. The value of this antibody for the immunohistochemical characterization of infiltrating cells in the thyroid glands from Obese strain chickens with spontaneous thyroiditis is demonstrated.
Cell surface and cell cycle analysis of metal‐induced murine T cell proliferation
Authors: Warner Garvin L. , Lawrence David A.
Published: February 2007

The heavy metale cations Pb2+, Ni2+ and Zn2+ have previously been shown to induce T cell proliferation which required the presence of both T cells and Ia+ cells at the initiation of culture. This work has examined the ability of these metals to induce cell cycle entry as determined by acridine orange cell cycle analysis. Cell surface phenotype analysis, performed on splenocytes stimulated with optimum metal concentrations (100 μM), indicated that in vitro T cell recovery (growth and/or longevity) was enhanced by Pb2+, Ni2+ and Zn2+. Furthermore, simultaneous examination of cell surface phenotype and cell cycle progression (propidium iodide) indicated that the predominant cell type proliferating in response to these metals was Thy‐1.2+. The metals differentially induced L3T4+ and Lyt‐2+ cells to enter the cell cycle. The ability of various monoclonal antibodies to modulate metal‐induced proliferation was examined. Anti‐L3T4a, anti‐I‐A and anti‐I‐E blocked metal‐induced proliferation. Anti‐Lyt‐2 only partially inhibited whereas anti‐Lyt‐1 was stimulatory. These results suggest that recognition of major histocompatibility complex‐encoded class II molecules is required for the induction of proliferation by these metals (similar to the autologous mixed lymphocyte response).
Synthetic peptides and β‐chain gene rearrangements reveal a diversified T cell repertoire for a λ light chain third hypervariable region
Authors: Bogen Bjarne , Snodgrass Ralph , Briand Jean Paul , Hannestad Kristian
Published: February 2007

Twelve L3T4+ Ly‐2.2− subclones, derived from 4 independent BALB/c T cell lines, responded to a combination of the I‐Ed molecule and a synthetic peptide corresponding to residues 91–108 of the λ light chain from BALB/c myeloma protein M315 (α, λ2). Peptide analogues in which the mutated residues Arg95 or Asn96 were exchanged with the corresponding germ‐line‐encoded Ser95 or Thr96 had an abolished or greatly reduced capacity to stimulate T cell clones. However, responses of subclones to an analogue where the mutated Phe94 was substituted with the germ‐line‐encoded Tyr94revealed three specificity patterns: 5 clones reacted only with the λ2315 peptide, 6 clones responded equally well to both peptides and a single clone reacted better with the Tyr94 analogue. Analysis of the T cell receptor β‐chain gene rearrangements disclosed 7 distinct rearrangements, identical rearrangements only being found for subclones originating from the same line. At least 3 different Vβ genes were used. Subclones with identical or nearly identical peptide specificity, major histocompatibility complex‐restriction and alloreactivity could differ in their Vβ or Jβ gene segment utilization.
B cell dependence of the congeneic barrier towards idiotype‐carrying cells
Authors: Bösing‐Schneider Rita , Selinka Hans‐Christoph , Lehle Georg
Published: February 2007

Immune cells transferred into nonirradiated animals of the same genotype face a barrier which severely affects their capacity to function in the host. We studied this phenomenon in allotype‐congeneic animals. When anti‐dextran immune cells of the responder strain (BALB/c‐Igha) are injected into an allotype‐congeneic host (BALB‐Ighb) the grafted cells are suppressed to give an idiotype‐positive response. This congeneic barrier of thymus‐independent immune cells is lost in mice carrying an X‐linked B cell defect: when idiotype‐positive immune cells from responder (CBA/N × BALB/C)F1 mice are transplanted into congeneic nonresponder animals (CBA/N × BALB‐Ighb)F1, female recipients are nonpermissive towards grafted cells whereas B cell‐defective male littermates allow donor cells to develop an idiotype‐positive anti‐dextran response. These results show that the congeneic barrier towards dextran‐immune cells is related to the maturation stage of B cells in the recipient. Since B cell‐defective (CBA/N × BALB/C)F1 animals do not display an anti‐idiotypic response in contrast to intact littermates and because CB16‐KN mice are nonpermissive towards CB8‐K lymphocytes, differing in VH genes only, we suggest that the “isogeneic barrier” depends on a mechanism recognizing VH structures.
Maternal transmission of idiotypic network interactions selecting available T cell repertoires
Authors: Martinez‐A. Carlos , Toribio Maria Luisa , De La Hera António , Cazenave Pierre‐André , Coutinho António
Published: February 2007

Up to 75% of 2,4,6‐Trinitrophenyl (TNP)‐self‐specific helper T cells from normal BALB/c mice share a clonotypic determinant with the anti‐TNP myeloma protein MOPC 460, recognized by the monoclonal antibody F6(51). Immunization of adult BALB/c mice with the MOPC 460 idiotype (Ab2 mice) leads to high titers of circulating anti‐idiotypic antibodies but has no influence on the expression of the T cell clonotype. In contrast, TNP‐self‐specific helper cells prepared in progenies from Ab2females, or in BALB/c mice treated as neonatals with anti‐idiotypic antibodies, fail to express the corresponding T cell clonotype when immunized as adults. These results demonstrate the idiotype‐dependent selection of T cell repertoires early in life and their stability in adults.
Antigen‐specific activation of autoreactive B cells in normal human individuals
Authors: Logtenberg Ton , Kroon Ali , Gmelig‐Meyling Frits H. J. , Ballieux Rudy E.
Published: February 2007

The purpose of our study was to determine if normal human B cells can be activated to autoantibody production using an antigen‐specific system. For this purpose we investigated the in vitro antibody response to the autoantigen thyroglobulin (Tg) employing soluble or insolubilized Tg (i‐Tg) and a B cell growth and differentiation factor (BDGF) to stimulate lymphocytes from healthy individuals. Similar experiments were carried out with the xenoantigen ovalbumin (OVA). The presence of Tg and OVA‐reactive B cells was demonstrable by stimulating lymphocytes from tonsil, spleen and blood with a combination of pokeweed mitogen and formalinized Staphylococcus aureus: mitogen stimulation resulted in the generation of IgM anti‐Tg and IgM anti‐OVA antibody‐forming cells (AFC) as detected in a spot enzyme‐linked immunosorbent assay. Soluble antigen failed to induce autoantibody production. However, i‐Tg or i‐OVA did activate normal tonsil and spleen B cells. Differentiation of these activated B cells to IgM AFC required the presence of BGDF, derived from a human T hybrid clone. Preincubation experiments with the particulate autoantigen show that a specific activation signal is provided by the antigen which subsequently renders the B cells responsive to BGDF. i‐Tg‐dependent stimulation of B lymphocytes could be inhibited by adding free Tg to the cultures; the same applied to i‐OVA stimulation. We conclude that (a) the normal human B cell repertoire contains B cells that can be activated to autoantibody production by the autoantigen Tg if the necessary T cell signals are provided. Thus, these B cells are not in an inherently anergic state, (b) Similar mechanisms seem to play a role in the activation of B cells responding to i‐OVA and i‐Tg.
T11TS, the cell surface molecule binding to the “erythrocyte receptor” of T lymphocytes: cellular distribution, purification to homogeneity and biochemical properties
Authors: Hünig Thomas , Mitnacht Rita , Tiefenthaler Georg , Köhler Christine , Miyasaka Masayuki
Published: February 2007

T11 target structure (T11TS) is a sheep cell surface glycoprotein that binds to the E receptor of human and sheep T lymphocytes. Here we report that T11TS has a broad tissue distribution, including mature and immature hematopoietic cells, vascular endothelium and smooth muscle. The density of T11TS expression was determined by Scatchard analysis with radiolabeled anti‐T11TS monoclonal antibody. Red blood cells bound 10 000, and leukocytes bound 4000 to 23 000 antibody molecules per cell. T11TS was purified to homogeneity by immune‐affinity and preparative sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, and some of its biochemical properties were determined. T11TS is an acidic (pl 4.5) membrane glycoprotein that binds to concanavalin A. It has 2 or 3 N‐glycosidically linked carbohydrate side chains of the mature phenetype, no O‐linked sugars, and an apparent mol. mass of 42 kDa (glycosylated) and 32 kDa (deglycosylated). The anti‐T11TS monoclonal antibody L180/1, which blocks binding of sheep red blood cells to CD2, recognizes a protein determinant on T11TS. These findings are discussed with respect to the possible function of the CD2‐T11TS system as a set of complementary cell interaction molecules involved in T cell activation.
Requirement of H‐2 heterozygosity for autoimmunity in (NZB × NZW)F1 hybrid mice
Authors: Paper Short , Hirose Sachiko , Ueda Genjiro , Noguchi Kazuo , Okada Takashi , Sekigawa Iwao , Sato Hidetoshi , Shirai Toshikazu
Published: February 2007

In the F1 hybrid of autoimmune New Zealand Black (NZB) and phenotypically normal New Zealand White (NZW) mice, there occurs a severe systemic lupus erythematosus (SLE)‐like autoimmune disease more fulminant than that found in the parental NZB mice. To determine the role of the H‐2 complex in the pathogenesis of autoimmune disease of the (NZB × NZW)F1 hybrid, we developed H‐2‐congenic NZB (NZB.H‐2Z) and NZW (NZW.H‐2d) strains, and compared the degree of autoimmune features between congenic H‐2d/H‐2d and H‐2z/H‐2z homozygous F1 hybrids and the original H‐2d/H‐2z heterozygous (NZB × NZW)F1 hybrid. We found that autoimmune features such as productions of IgG class anti‐DNA antibodies and retroviral gp70 immune complexes and the development of renal disease were to a great extent reduced in both H‐2 homozygous F1 hybrids, as compared with the H‐2 heterozygous (NZB × NZW)F1 hybrid. It would thus appear that the heterozygosity of H‐2d haplotype derived from NZB and H‐2Z from NZW is essential for the autoimmune disease characteristic of the (NZB × NZW)F1 hybrid.
Large granular lymphocytes or “Pit cells” from rat liver: isolation, ultrastructural characterization and natural killer activity
Authors: Bouwens Luc , Remels Linda , Baekeland Marijke , Van Bossuyt Hans , Wisse E.
Published: February 2007

Considerable numbers of large granular lymphocytes (LGL) were isolated from rat liver by a simple method consisting of sinusoidal lavage at elevated (50 cm water column) perfusion pressure. This method gave a yield comparable with the enzymatic dissociation method commonly used for the isolation of nonparenchymal liver cells, but was shorter in time and had the advantage of avoiding the potentially harmful effects of the dissociating enzymes. The isolated LGL were highly cytotoxic against YAC‐1 lymphoma cells and this cytolytic activity was blocked by treatment of the effector cells with an antibody against natural killer cells (anti‐asialo GM1). We characterized the hepatic LGL as nonphagocytic, nonadherent, peroxidase‐negative and acid phosphatase‐positive cells which could be enriched in the low‐density fraction of a Percoll gradient. At the light microscopic level, they showed characteristic azurophilic granules which corresponded to strongly osmiophilic granules with a specific morphology in electron microscopy. It is concluded that these LGL are identical to the “pit cells” which were formerly described by electron microscopy in situ as normal components of the liver sinusoids and which are easily recognized by their fine structure. It is also proposed that the liver may represent one of the major natural killer organs.
Transmembrane signalling via the T11‐dependent pathway of human T cell activation. Evidence for the involvement of 1,2‐diacylglycerol and inositol phosphates
Authors: Pantaleo Giuseppe , Olive Daniel , Poggi Alessandro , Kozumbo Walter J. , Moretta Lorenzo , Moretta Alessandro
Published: February 2007

It has previously been shown that some anti‐T11 monoclonal antibodies, when used in combination, can activate the human T cell line Jurkat to produce interleukin 2. In this study, we investigate the mechanism by which perturbation of different epitopes of T11 molecules induces activation in Jurkat cells. We show that this activation is initiated by a T11‐mediated increase in the concentration of free cytoplasmic calcium ions ([Ca2+]i). The initial increment in [Ca2+]i can occur when extracellular Ca2+ is depleted by EGTA, indicating that Ca2+ from intracellular stores is mobilized. As an early response to extracellular signals provokes a rapid breakdown of a class of lipid known collectively as the phosphoinositides, we measured the levels of phosphatidyl‐inositol bisphosphate (PIP2) which is hydrolyzed to generate inositol triphosphates (IP3), the putative mobilizer of Ca2+ from internal stores and 1,2‐diacylglycerol (DAG), the physiological activator of protein kinase C. Monoclonal antibodies directed either against different epitopes of T11 molecules or the T3‐Ti antigen receptor complex provoke a rapid breakdown of PIP2, the parental product from which IP3 and DAG derive. In addition antibodies to either the T11 molecules or T3‐Ti antigen receptor complex induce marked elevations in IP3, other inositol phosphate compounds and DAG. Taken together, these data indicate that, during T cell activation, due to the perturbation of T11 molecules or T3‐Ti antigen receptor complex, membrane phosphoinositides are specifically hydrolyzed. This hydrolysis of phosphoinositides generates two putative second messengers such as IP3 and DAG, which mobilizes Ca2+ from intracellular stores and stimulates protein phosphorylation, respectively.
Relationship between thymus ontogeny and DNA ligase expression in the chicken
Authors: Jotereau Francine , Maniey Dominique , David Jean‐Claude
Published: February 2007

DNA ligase expression was studied in the embryonic chicken thymus. As previously reported, during thymus ontogeny two separate and successive (8 S and 6 S) forms of enzyme are found. The switch from the heavy to the light form takes place at around 18 days of incubation in situ. The demonstration that two successive generations of thymic lymphoid precursor cells develop in the embryonic bird thymus and that the replacement of the first by the second thymocyte generation takes place at around 18 days suggested the possibility that each form of enzyme could be restricted to a given thymocyte generation. By either culturing or transplanting embryonic thymuses of different ages it appears that the switch from the heavy to the light form of DNA ligase is not related to a change over of the first by the second generation of embryonic thymocytes but rather to some maturation process of the thymic lymphocytes starting from 17 days of embryonic life. The influence of extrathymic factors on the turning on of the expression of the 6 S DNA ligase in the post‐natal environment is also suggested.
Expression of Pgp‐1 (or Ly24) by subpopulations of mouse thymocytes and activated peripheral T lymphocytes
Authors: Lynch Felicity , Chaudhri Geeta , Allan Jane E. , Doherty Peter C. , Ceredig Rhodri
Published: February 2007

The expression of Pgp‐1 (Ly24) by subpopulations of thymocytes was investigated and a subpopulation of Lyt‐2−/L3T4−/J11d− thymocytes was identified which contained significant numbers (80%) of Pgp‐1+ cells. Among freshly isolated lymph node T cells but not cortisone‐resistant thymocytes, Pgp‐1 expression was heterogeneous. Stimulation of T lymphocytes with either concanavalin A or the combination of phorbol myristate acetate plus calcium ionophore resulted in increased Pgp‐1 expression which was found to be regulated independently of DNA synthesis and interleukin 2 receptor expression. T cells in the cerebrospinal fluid exudate of mice infected with lymphocytic choriomeningitis virus were also found to be Pgp‐1+.
Total Synthesis ofrac‐γ‐Indomycinone by Baker–Venkataraman Rearrangement
Authors: Krohn Karsten , Tran‐Thien Hoan Trang , Vitz Jürgen , Vidal Anne
Published: February 2007

The total synthesis of racemic γ‐indomycinone (rac‐3) was achieved by Baker–Venkataraman rearrangement of ester11to the diketone12, acid‐catalyzed cyclization to the anthrapyranone13, followed by methyl ether cleavage and acetylation to16, selective bromination of the branched side chain with simultaneous SN1‐type hydroxy substitution to23and transesterification torac‐3. The corresponding γ‐indomycinone 11‐methyl ether (rac‐20) was prepared in a similar reaction sequence.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
CE with sequential light‐emitting diode‐induced fluorescence and electro‐chemiluminescence detections for the determination of amino acids and alkaloids
Authors: Chang Po‐Ling , Lee Kun‐Hong , Hu Cho‐Chun , Chang Huan‐Tsung
Published: February 2007

This paper describes the determination of alkaloids and amino acids (AAs) using CE in conjunction with sequential light‐emitting diode‐induced fluorescence (LEDIF) and electrochemiluminescence (ECL) detections. In the CE‐LEDIF‐ECL system, the ECL detector was located in the outlet of the capillary, while the LEDIF detector was positioned 12 cm from the outlet. Naphthalene‐2,3‐dicarboxaldehyde (NDA) was used to form fluorescent AA–NDA derivatives from AAs possessing primary amino groups, while Ru(bpy)32+ was used to obtain ECL signals for analytes having secondary and tertiary amino groups. In the presence of poly(ethylene oxide), we accomplished the CE‐LEDIF‐ECL separation of a mixture of 12 AA–NDA derivatives, anabasine, nicotine, and proline within 11 min. This low‐cost CE‐LEDIF‐ECL system allows the analysis of these AA–NDA derivatives and alkaloids at concentrations in the ranges of 49 nM–0.2 μM and 0.66–4.7 μM, respectively. We applied our CE‐LEDIF‐ECL system to the analysis of a urine sample and also to tobacco extracts. We obtained good qualitative and quantitative results when using this method with these analytes: the RSDs were below 3.0 and 2.8%, respectively. This CE‐LEDIF‐ECL system provides the advantages of high efficiency, speed, and sensitivity for the analysis of analytes possessing amino groups.
A new algorithm for surface tension model in moving particle methods
Authors: Zhang Shuai , Morita Koji , Fukuda Kenji , Shirakawa Noriyuki
Published: February 2007

A new algorithm for the surface tension model was developed for moving particle methods. The algorithm is based on the link‐list search algorithm and the continuum surface tension (CST) model. The developed algorithm with the CST model was implemented to a kind of moving particle approach, the finite volume particle (FVP) method. The FVP method with the new algorithm was tested by oscillatory behaviour of a two‐dimensional droplet. The oscillatory period agrees well with analytical one, and the transient shape of the droplet is also in good agreement with that obtained by other numerical methods. The droplet impact on a liquid surface was also studied using the new algorithm. The deposition and splashing phenomena were clearly reproduced. Simulated spread radius of the splashing phenomena was consistent with a power law. Copyright © 2007 John Wiley & Sons, Ltd.
Critical evaluation of CFD codes for interfacial simulation of bubble‐train flow in a narrow channel
Authors: Özkan Furkan , Wörner Martin , Wenka Achim , Soyhan Hakan S.
Published: February 2007

Computational fluid dynamics (CFD) codes that are able to describe in detail the dynamic evolution of the deformable interface in gas–liquid or liquid–liquid flows may be a valuable tool to explore the potential of multi‐fluid flow in narrow channels for process intensification. In the present paper, a computational exercise for co‐current bubble‐train flow in a square vertical mini‐channel is performed to investigate the performance of well‐known CFD codes for this type of flows. The computations are based on the volume‐of‐fluid method (VOF) where the transport equation for the liquid volumetric fraction is solved either by the methods involving a geometrical reconstruction of the interface or by the methods that use higher‐order difference schemes instead. The codes contributing to the present code‐to‐code comparison are an in‐house code and the commercial CFD packages CFX, FLUENT and STAR‐CD. Results are presented for two basic cases. In the first one, the flow is driven by buoyancy only, while in the second case the flow is additionally forced by an external pressure gradient. The results of the code‐to‐code comparison show that only the VOF method with interface reconstruction leads to physically sound and consistent results, whereas the use of difference schemes for the volume fraction equation shows some deficiencies. Copyright © 2007 John Wiley & Sons, Ltd.
Reactions to skill assessment: The forgotten factor in explaining motivation to learn
Authors: Bell Bradford S. , Ford J. Kevin
Published: February 2007

The study presented here examined the effects of trainees' reactions to skill assessment on their motivation to learn. A model was developed that suggests that two dimensions of trainees' assessment reactions, distributive justice and utility, influence training motivation and overall training effectiveness. The model was tested using a sample of individuals (N = 113) enrolled in a truck driving training program. Results revealed that trainees who perceived higher levels of distributive justice and utility had higher motivation to learn. Training motivation was found to significantly predict several measures of training effectiveness. Trainees' performance on the pretraining assessment and trait goal orientation exhibited direct and interactive effects on their reactions to the skill assessment. Implications of these findings for future research on reactions to skill assessments are identified, along with the practical implications for the design and conduct of training needs assessment.
The impact of the perceived purpose of electronic performance monitoring on an array of attitudinal variables
Authors: Wells Deborah L. , Moorman Robert H. , Werner Jon M.
Published: February 2007

As a form of performance monitoring, electronic performance monitoring (EPM) offers the opportunity for unobtrusive and continuous performance data gathering. These strengths can also make EPM stressful and threatening. Many features of performance evaluation systems, including the organizational purposes for which they are used, can affect employee attitudes. We explored the relationships among the perceived purpose of EPM and an array of job attitudes, including fairness, job satisfaction, organizational commitment, and felt obligation to reciprocate. Results indicate that when monitoring is viewed as developmental, it is judged as fairer than when it is perceived as a deterrent to future behavior and is also associated with higher levels of job satisfaction, organizational commitment, and felt obligation. These findings suggest that employees will respond more positively to EPM when managers and human resource development professionals carefully frame the reasons for monitoring and feedback in constructive, developmental terms.
Thymidylate synthase and dihydropyrimidine dehydrogenase mRNA expression after administration of 5‐fluorouracil to patients with colorectal cancer
Authors: Mauritz Robert , van Groeningen Cees J. , Smid Kees , Jansen Gerrit , Pinedo Herbert M. , Peters Godefridus J.
Published: February 2007

This study explores the effect of 5‐fluorouracil (5FU) exposure on mRNA levels of its target enzyme thymidylate synthase (TS) and the rate‐limiting catabolic enzyme dihydropyrimidine dehydrogenase (DPD) in tumors of colorectal cancer patients. TS and DPD mRNA levels were determined in primary tumor and liver metastasis samples from patients who were either not pretreated (n = 29) or given one presurgery bolus of 5FU (n = 67). In both groups a wide variation in TS mRNA levels was observed. Median TS mRNA expression in 17 primary tumors of exposed patients was 3.0‐fold higher than in 19 primary tumors of unexposed patients (p = 0.015). TS mRNA expression in liver metastasis samples of exposed patients (n = 16) was also higher (5.2‐fold) than that of unexposed patients (n = 48; p < 0.001). Also DPD mRNA expression displayed a large degree of interpatient variation. No difference in DPD expression in liver metastasis samples was observed between exposed and unexposed patients. However, median DPD mRNA expression in 15 primary tumors of exposed patients was 3.2‐fold lower than in 18 primary tumors of unexposed patients (p = 0.027). In conclusion, administration of 5FU in vivo influences the gene expression of TS and DPD. © 2007 Wiley‐Liss, Inc.
Inhibition of hepatocarcinoma and tumor metastasis to liver by gene therapy with recombinant CBD‐HepII polypeptide of fibronectin
Authors: Liu Yi , Huang Bo , Yuan Ye , Gong Wei , Xiao Han , Li Dong , Yu Zhi‐Rui , Wu Feng‐Hua , Zhang Gui‐Mei , Feng Zuo‐Hua
Published: February 2007

Unlike the intact fibronectin (FN) molecule, some proteolytic or recombinant fragments of FN possess inhibitory activities on tumor, providing potential strategies in tumor therapeutics. Using the hydrodynamics‐based gene delivery technique, we demonstrated that the treatment by in vivo expression of a recombinant CBD‐HepII polypeptide of FN, designated as CH50, strongly inhibited the tumor growth, tumor invasion and angiogenesis. Such inhibitory effects of CH50 on tumor were partly ascribed to its influence on the activities of MMP‐9 and αvβ3 integrin. The in vivo expressed CH50 decreased both the production and the activity of MMP‐9 in tumor tissues. CH50 also down‐regulated αvβ3 expression in tumor cells and endothelial cells in vitro. The decreased activity of αvβ3 integrin was proved by its reduced binding ability to fibrinogen and the down‐regulation of cdc2 expression. The gene therapy with CH50 not only prolonged the survival of mice bearing hepatocarcinoma in the liver, but also suppressed the growth and invasive ability of tumor in spleen and its metastasis to liver. Taken together, these findings suggest a prospective utility of CH50 in the gene therapy of liver cancer. © 2007 Wiley‐Liss, Inc.
High resolution real time ultrasound of the carotid bifurcation
Authors: Cooperberg P. L. , Robertson W. D. , Fry P. , Sweeney V.
Published: February 2007

We have been using a high resolution real time ultrasound mechanical sector scanner to visualize the carotid bifurcation. Twenty‐six patients were studied before carotid arteriography for transient ischemic attacks. One bifurcation was not adequately visualized. Of the remaining 51, plaques were identified correctly in 29; absence of plaques was identified correctly in 15; small plaques were demonstrated by ultrasound in two that did not appear on the arteriogram; and four small plaques and one significant stenosis were not identified by ultrasound.
Identification of fetal growth retardation by ultrasonographic estimation of total intrauterine volume
Authors: Levine Sandra C. , Filly Roy A. , Creasy Robert K.
Published: February 2007

Recent literature has suggested that total intrauterine volume (TIUV) estimation is useful for distinguishing normal from growth‐retarded fetuses. One hundred seventy‐nine measurements of TIUV were obtained from the ultrasonograms taken between 21 and 40 weeks of gestation in 140 patients who delivered average birthweight babies. We constructed a mean curve for TIUV with upper and lower 2.5 and 10% tolerance limits and later evaluated the TIUV's of 16 patients with growth‐retarded fetuses. Nine of these fetuses had birthweights below the fifth percentile for gestational age, and in each of these pregnancies the TIUV ultimately fell below the lower 2.5% tolerance limit.
Ultrasonic visualization of Wirsung's duct: Dream or reality?
Authors: Eisenscher Albert , Weill Francis
Published: February 2007

Ultrasonic visualization of normal and pathological Wirsung's ducts has become quite common, especially with the newest gray scale units. Ductal images were studied in 17 cases of quiescent chronic pancreatitis. Duct dilatation could be identified in the majority.
The ultrasonic findings in intussusception of the blind loop in a jejunoileal bypass for obesity
Authors: Sarti Dennis A. , Zablen Marshall A.
Published: February 2007

A 34 year old woman with bowel bypass surgery and persistent abdominal pain had intussusception of the blind loop, which was visualized on an abdominal ultrasound examination. The ultrasonic and radiographic findings are compared and presented. Ultrasound should prove to be an invaluable tool in evaluating abdominal pain in bowel bypass patients.
Evaluation of a quarter wavelength matching layer transducer in abdominal scanning
Authors: Schuette William H. , Shawker Thomas H. , Hall Thomas E.
Published: February 2007

A focused ultrasonic transducer employing quarter wavelength matching technology is compared to one of conventional design. The effect of the 6 db improvement in signal‐to‐noise ratio is demonstrated.
Gray scale ultrasound in adnexal thickening: Correlation with laparoscopy
Authors: Kirkpatrick Rob H. , Nikrui Najmosama , Wittenberg Jack , Hann Lucy , Ferrucci Joseph T.
Published: February 2007

A retrospective comparison between ultrasound and subsequent laparoscopy was made in 70 female patients to evaluate the sonographic features of minimal pelvic disease (in particular, adnexal thickening). The overall accuracy of sonography as compared with laparoscopy was 75 percent (53 of 70), with a true positive rate of 72 percent (40 of 51) and a true negative rate of 68 percent (13 of 19). In this study the concept of clinical or sonographic adnexal thickening did not correlate with observations at laparoscopy. Of the 7 patients diagnosed by ultrasound as having adnexal thickening, only 1 had pelvic inflammatory disease, whereas the other 6 showed no abnormalities at laparoscopy.
Lateral decubitus position for demonstration of the aortic bifurcation
Authors: Athey Patricia A. , Tamez Lydia
Published: February 2007

A technique for demonstrating the aortic bifurcation and proximal iliac arteries is presented. This technique is performed in the left lateral decubitus position and uses the right lobe of the liver as an acoustic window.
The influence of hydration and bladder distension on the sonographic diagnosis of hydronephrosis
Authors: Morin Martin E. , Baker Dennis A.
Published: February 2007

Renal sonography is frequently employed to exclude obstructive uropathy in patients with uremia. Sonographic findings of moderate bilateral hydronephrosis were encountered in a dehydrated patient undergoing rehydration. Subsequent excretory urography and a follow‐up renal sonogram were normal. To investigate the possibility that hydration and bladder distension in an otherwise normal and unobstructed collecting system could result in hydronephrosis detectable by ultrasound, 23 apparently normal volunteers underwent renal sonography in the hydrated and basal states. The filled urinary bladder in a patient undergoing hydration frequently results in the sonographic appearance of hydronephrosis.
A simple optical method for observing medical ultrasound pulse characteristics in vitro
Authors: Riley Ward A. , Barnes Ralph W. , McKinney William M.
Published: February 2007

An optical method is described for studying the spatial and temporal characteristics of broad‐band ultrasonic pulses propagating in transparent media. The simplicity of the approach suggests its consideration as a method for calibration and comparison of the transmitted pulse characteristics of medical ultrasound systems.
Sonographic anatomy of the normal placenta
Authors: Spirt Beverly A. , Kagan Eugene H. , Rozanski Richard M.
Published: February 2007

The normal anatomy of the placenta and the retroplacental area can be well defined with gray scale sonography. The placenta has a characteristic granular echo pattern, with strong echoes emanating from the chorionic plate. After 37 weeks, strong echoes representing calcification may appear; this is a normal physiologic process. The significance of early calcification is unclear. The retroplacental myometrium and venous drainage of the placenta are easily visualized by sonography. Variations in the appearance of the retroplacental myometrium result from different degrees of bladder filling and from uterine contractions. These normal retroplacental structures should not be mistaken for myomas or hematomas.
Echogenic fluid: A pitfall in the ultrasonographic diagnosis of cystic lesions
Authors: Thurber Lynette A. , Cooperberg Peter L. , Clement John G. , Lyons Edward A. , Gramiak Raymond , Cunningham Jerry
Published: February 2007

Although it is well known that biliary sludge can produce fine diffuse echoes within the gallbladder, it is less commonly appreciated that other cystic structures may contain echogenic fluid and therefore be mistaken sonographically for solid lesions. In this article three cases of splenic cysts and one case each of pyometrocolpos, hydroureter, and pyonephrosis presented with diffuse fine echoes in the fluid. Three of these cases were misinterpreted as a result of this echogenic appearance. These cases serve to emphasize the need for awareness of the echogenicity of some types of fluid and the value of other signs of cystic lesions besides absence of internal echoes.
The fluid‐filled stomach: A new sonic window
Authors: Weighall Steven L. , Wolfman Neil T. , Watson Nat
Published: February 2007

Gastric air and peristalsis usually are obstacles to ultrasound imaging of the tail of the pancreas. Fifteen normal volunteers were scanned transversely in the supine position before and after intravenous administration of glucagon (1 mg) and oral administration of water. In 13 of 15 subjects glucagon produced a dilated gastric fundus that retained fluid for 30–60 min, thus allowing good imaging of the pancreatic tail in 10 subjects and fair imaging in 2 subjects. This method of creating a gastric sonic window should prove to be valuable in ultrasound imaging of the pancreas.
Detection of persistent left superior vena cava by two‐dimensional contrast echocardiography
Authors: Stewart James A. , Fraker Theodore D. , Slosky David A. , Wise N. Kent , Kisslo Joseph A.
Published: February 2007

One hundred seventy adult patients with possible congenital or valvular heart disease underwent contrast two‐dimensional echocardiographic examination as part of a precatheterization evaluation. Persistent left superior vena cava was detected in 5 patients, each of whom demonstrated an abnormally large coronary sinus. Injection of echocardiographic contrast material from a peripheral left arm vein resulted in early opacification of this structure before other right‐side chambers, thus suggesting abnormal venous drainage. Persistent left superior vena cava was confirmed in all 5 patients at the time of catheterization and/or surgery.
Prenatal diagnosis of fetal lymphatic system abnormalities by Ultrasound
Authors: Adam A. H. , Robinson H. P. , Aust F. , Pont M. , Hood V. D. , Gibson A. A. M.
Published: February 2007

Antenatal ultrasound diagnoses of gross lymphatic system abnormalities were made in three fetuses. Although the diagnosis was made in only 1 fetus at a stage early enough in pregnancy to allow selective termination, knowledge of the abnormality in the remaining 2 fetuses proved to be valuable for subsequent management of those pregnancies. It is stressed that the extent of the abnormality must be carefully assessed because of the possibility of corrective surgery should the lesion be small and that the parents must be given detailed counseling before any definitive measures are taken.
Ultrasound findings in liver hydatid cysts
Authors: Hadidi Ali
Published: February 2007

Eighty‐one liver hydatid cysts evaluated by gray‐scale ultrasound were accumulated in our experience over a period of 2 years. The echographic evidence in accordance with our experience can be categorized as follows: (a) nonsuppurative hydatid cysts in which echo‐free area within the fine homogeneous structure of the organ provide the basic clue to the diagnosis; then the echographic appearance of the wall offers further hints to the identity of solitary, multiloculated, and multiple cysts; (b) suppurative hydatid cysts in which, depending on the intensity of secondary microbial infection, the echo‐free area turns to a low, medium, or high level of echoes while holding its constitutional pattern. This report is designed to present the various ultrasound patterns of hydatid disease of the liver and show how ultrasound may be most effective in achieving the correct diagnosis.
Echocardiographic aortic ejection area as a reflection of left ventricular stroke volume
Authors: Jacobs William R. , Croke Robert P. , Loeb Henry S. , Gunnar Rolf M.
Published: February 2007

Systolic cusp separation of normal aortic valves has been shown by echocardiography and by angiography to be related to left ventricular stroke volume. In this study, stroke volume was compared with echocardiographic area between the aortic cusps in systole (aortic ejection area). An excellent correlation was observed (r = 0.93) over a wide range of stroke volumes, even in the presence of mitral regurgitation. Stroke volume appears to correlate more closely with aortic ejection area than with angiographic or echocardiographic measurements of peak systolic cusp separation.
Real‐time ultrasound examination in the diagnosis of gastrointestinal tumors
Authors: Schwerk W. , Braun B. , Dombrowski H.
Published: February 2007

Inflammatory and neoplastic infiltrations of the intestinal wall lead in advanced stages to a tumorous thickening that can be visualized by ultrasound as the so‐called cockade sign. The possibilities and limitations of ultrasound diagnosis of gastrointestinal tumors are presented. Over a period of 2 years, 73 tumors were diagnosed, 39 primarily by means of ultrasound with the real‐time technique; 15 tumors were curatively resected at the time of primary ultrasound diagnosis.