bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigen presentation by hapten‐specific B lymphocytes III. Analysis of the immunoglobulin‐dependent pathway of antigen presentation to interleukin 1‐dependent T lymphocytes
Authors: Rock Kenneth L. , Haber Susan I. , Liano Douglas , Benacerraf Baruj , Abbas Abul K.
Published: February 2007

The ability of antigen‐specific murine B lymphocytes to present antigen to a normal (nontransformed) antigen‐specific, interleukin (IL)1‐dependent T cell clone and to heterogeneous T lymphocytes was investigated. Hapten‐specific lymphocytes present protein antigens to both the D10G.4.1 T cell clone and heterogeneous immune T cells. When the antigen bears an epitope recognized by the specific B cell, the subsequent presentation of this antigen is 102–104‐fold more efficient, as compared to the same, but nonhaptenated protein. The requisite B lymphocyte binds hapten, is radiosensitive and is nonadherent to plastic. The hapten‐specific antigen presentation ‐ is blocked by antibodies to the surface Ig receptor, while the presentation of unmodified protein is unaffected. These observations are identical to our findings in studies of B cell antigen presentation to T‐T hybridomas and therefore demonstrate the generality of the immunoglobulin‐dependent pathway of presentation. However, in contrast to the results with T‐T hybridomas, the specific B lymphocytes are necessary, but not sufficient, to activate IL 1‐dependent T cells. A third cell is required for both B lymphocyte immunoglobulin‐dependent and nonspecific antigen‐presentation. This cell is radioresistant, plastic adherent and of low density. The requirement for this third cell can be circumvented by supplementing cultures with highly purified IL 1. These results demonstrate that the remarkably efficient ability of B lymphocytes to present antigen is operative with factor‐dependent T lymphocytes. Furthermore, conventional accessory cells also appear to play a role in this process, which is consistant with their known requirement in antigen‐specific T‐B interactions in the generation of antibody responses.
Two natural killer cell populations which belong to T cell lineage in nude mice
Authors: Habu Sonoko , Shimamura Kazuo , Tamaoki Norikazu , Kumagai Yoshihiro , Okumura Ko
Published: February 2007

Enriched natural killer (NK) cell populations from BALB/c nude mice obtained by using nylon wool column (NWC) separation were stained with anti‐Thy‐1 and anti‐asialo GM1 (GA1), and then were fractioned by flow cytometry into 4 cell populations: Thy‐1+GA1+ cells, Thy‐1+GA1− cells, Thy‐1−GA1+ cells and Thy‐1−GA1− cells. These cell populations were sorted out by flow cytometry and were examined for NK activity. Of the sorted cells, high NK activity was found in the two populations, Thy‐1+GA1+ cells and Thy‐1−GA1+ cells. In the other populations expressing Thy‐1 antigen alone or expressing neither GM1 nor Thy‐1, NK activity was almost undetectable. The two cell populations with NK activity were lineaged with respect to rearrangement of the T cell receptor genes. Southern gel analysis using a cDNA probe containing the Dβ1, Jβ1.3 and Cβ1 genes of the T cell receptor showed a reduction of the germ‐line band of DNA in the 3 fractionated populations other than Thy‐1−GA1−cells. Since these observations were demonstrated in nude spleen cells, it is indicated that the cells with NK activity belong to T cell lineage even if they lack Thy‐1 expression and that they may develop out of the thymus, if they express Thy‐1 antigen.
Intracellular pathway of interleukin 2 following receptor‐mediated endocytosis
Authors: Lowenthal John W. , Robson MacDonald H. , Iacopetta Barry J.
Published: February 2007

Electron microscope autoradiography was used to examine the intracellular pathway of radioiodinated interleukin 2 ([125I]IL2) following its receptor‐mediated endocytosis in CTLL cells. Direct measurement of the kinetics of endocytosis showed that 60–70% of surface‐bound [125I]IL2 was internalized after 1 h at 37°C. [125I]IL2 was observed to enter cells through invagination of coated pits at the cell surface and to concentrate into lysosomal multivesicular bodies as early as 5–10 min after endocytosis. These results provide ultrastructural information on the intracellular pathway of IL2 and on its probable site of degradation within the cell.
Functional role in self reactivity for Ia antigens on murine synovial cells
Authors: Fournier Catherine , Takenaka Yoshitaka , Michel‐Bechet Marc
Published: February 2007

Cultures of synovial cells from normal CBA mice were established after collagenase treatment of synovial tissue collected from the knee joint. Morphological studies using light and electron microscopy have shown that confluent monolayers are composed of 90% triangular or stellate dendritic cells with numerous microvilli and 5% secreting cells containing many dense granules. Less than 5% contaminating cells, such as fibroblasts or macrophages, are present. The class I and class II antigens of the major histocompatibility complex, detected by indirect immunofluorescence or complement‐dependent cytotoxicity, are expressed on the cell surface of normal CBA synovial monolayers. Functional Ia antigens borne by synoviocytes are evidenced by the proliferative responses they elicit from syngeneic (or allogeneic) spleen cells after a 3‐day co‐culture. Similarly, monolayers of Ia+ synovial cells were obtained from both MRL/1pr mice, which spontaneously develop an autoimmune syndrome, and the control MRL/n mice. Spleen cells from young MRL/1pr exhibited significantly higher levels of blastogenesis in syngeneic co‐cultures than those from MRL/n mice. Conversely, with advancing age the syngeneic proliferative responses declined minimally for MRL/1pr mice and were unchanged for MRL/n mice. These findings suggest that Ia+ synovial cells can effectively interact with syngeneic lymphocytes and may initiate autoimmune reactivity.
Different human B cell subsets respond to interleukin 2 and to a high molecular weight B cell growth factor (BCGF)
Authors: Vazquez Aime , Gerard Jean‐Philipe , Olive Daniel , Auffredou Marie‐Thérèse , Dugas Bernard , Karray Saoussen , Delfraissy Jean‐François , Galanaud Pierre
Published: February 2007

After activation by anti‐μ antibody human B cells acquire the ability to proliferate in the presence of recombinant interleukin 2 (IL2), a 20‐kDa mol. mass B cell growth factor (BCGF) and a high mol. mass BCGF (50‐kDa BCGF). An anti‐IL2 receptor (IL 2R) monoclonal antibody inhibits the IL2‐dependent proliferation without affecting that induced by BCGF. B cells expressing the IL2R after anti‐μ antibody activation (IL2R+ cells) were separated from those not expressing IL2R (IL2R− cells). IL2 stimulated the proliferation of only IL2R+ cells whereas the 20‐kDa BCGF acted on both IL2R+ and IL2R− cells. Importantly, the 50‐kDa BCGF supported the proliferation of IL2R− cells whereas it was inactive on IL2R+ cells. Thus, the B cell subset responding to the 50‐kDa BCGF after anti‐μ antibody activation is distinct from that responding to IL2.
A surface molecule on guinea pig lymphocytes involved in adhesion and homing
Authors: Kraal Georg , Twisk Agaath , Tan Ben , Scheper Rik
Published: February 2007

A monoclonal antibody, CT4, which recognizes an antigenic determinant on the majority of guinea pig lymphocytes, was tested for its ability to interfere with adherence and homing capacity of lymphocytes. Incubation with F(ab′)2 fragments of the antibody blocks the in vitro binding to high endothelial venules (HEV) of both peripheral lymph nodes and Peyer's patches. When tested in vivo using a short‐term homing assay with radiolabeled cells also a reduction of migration into the spleen was observed. Fluorescence‐activated cell sorter analysis of lymph node cells showed a separation into duller and brightly positive cells whereas in the thymus the bright population is absent. Thymus cells adhere less effectively to HEV and this binding can only marginally be blocked by CT4 incubation. The results suggest a role of CT4 in adhesion processes.
Suppression of the anti‐hapten IgE antibody response with hapten‐modified spleen cells
Authors: Weber Ernst A. , Blaser Kurt
Published: February 2007

Spleen cells of BALB/c mice were chemically modified with phosphorylcholine or benzylpenicilloyl hapten. The i.v. administration of such cells into syngeneic animals suppressed the formation of specific IgE antibodies against the respective hapten. The IgE antibody response against ovalbumin, which was used as an immunogenic carrier for the haptens, was not affected and the anti‐hapten IgG or IgG1 response remained at the levels of the controls. The suppression could be transferred into X‐irradiated mice by T cells from tolerized animals. Moreover, it was demonstrated that not only the induction of IgE, but also an established anti‐hapten IgE antibody response is accessible to suppression by treatment with hapten‐modified spleen cells from syngeneic animals. The results indicate that the i.v. administration of antigen coupled to syngeneic spleen cells induces T cells which suppress the formation of specific IgE antibodies in the primary and the secondary response without significantly affecting the formation of IgG antibodies.
A specific serine proteinase is inducible in Lyt‐2+, L3T4− and Lyt‐2−, L3T4+ T cells in vitro but is mainly associated with Lyt‐2+, L3T4− effector cells in vivo
Authors: Simon Markus M. , Fruth Ulli , Simon Hans Georg , Kramer Michael D.
Published: February 2007

Recently, we and others reported on the expression of a serine proteinase in long‐term cultured murine T lymphocyte cell lines. In an attempt to explore the distribution and possible regulation of this enzyme in T lymphocyte subsets, we performed the presented detailed study. We found that the proteinase is not expressed by thymocytes and resting T cells but can be induced by lectin or antigen in combination with lymphokine sources in vitro in macrophage‐depleted unselected T cells as well as in both T cell subsets (Lyt‐2+, L3T4−and Lyt‐2−, L3T4+) separated by flow cyto‐fluorometry. Furthermore, it appears that cell‐associated proteinase activity is increasing with prolonged culture period of sensitized T lymphocytes and that it is higher in antigen‐activated as compared to lectin‐activated T cells. When tested for substrate specificity the T cell‐associated proteinase was shown to preferentially cleave model peptide substrates carrying L‐arginine at position P1 in combination with nonpolar amino acids at position P2 and P3. As concluded from its sensitivity to proteinase inhibitors the enzyme can be classified as a serine proteinase and by molecular sieving at high ionic strength it was shown to have a mol. mass of ∼ 50–60 kDa.

Analysis of in vivo activated T cells revealed that this particular proteinase was expressed in flow cytofluorometry sorted lymphocytic choriomeningitis virus‐specific Lyt‐2+, L3T4− cytolytic T lymphocytes but not in Lyt‐2−, L3T4+T cells presensitized with either Listeria monocytogenes or I‐A alloantigens.

The data demonstrate that the two T cell subsets (Lyt‐2+, L3T4−; Lyt‐2−,L3T4+) have distinct in vitro induction requirements for the expression of proteinase and that after activation of T cells in vivo the enzyme is preferentially associated with Lyt‐2+, L3T4−effector cells.
Lymphoma models for B cell activation and tolerance IV. Growth inhibition by anti‐Ig of CH31 and CH33 B lymphoma cells
Authors: Pennell Christopher A. , Scott David W.
Published: February 2007

CH31 and CH33 are B cell lymphomas whose growth in vitro is inhibited by anti‐Ig reagents, including both polyclonal and monoclonal anti‐μ antibodies, and an anti‐idiotype antiserum. Antibodies against class I or class II major histocompatibility complex antigens do not affect the growth of these cells. Inhibition is dependent on surface Ig cross‐linking and does not require ligand binding to Fc receptors. Interestingly, the inhibition of growth by anti‐μ, is reversed in CH31 (but not CH33) by E. coli lipopolysaccharide. These lymphomas should provide excellent models to study the mechanisms of growth inhibition mediated by surface Ig cross‐linking and the pathways of its reversal.
B cell receptors for interleukin 2: demonstration of IL 2 internalization and of complementary effects of lipopolysaccharide and phorbol diester on receptor expression
Authors: Lowenthal John W. , Link Ladislav , Hashimoto Noboru , Zubler Rudolf H.
Published: February 2007

We have previously shown (J. Exp. Med. 1984. 160: 1170) that murine B cells activated with lipopolysaccharide (LPS) and rabbit anti‐mouse Ig antibodies together (LPS‐RaMIg blasts) express high‐affinity interleukin 2 receptors (IL2R) and respond to IL2. This is not the case for B cells activated with either LPS alone (LPS blasts) or anti‐Ig alone. In the present study IL2R function and expression were further investigated by using this model. First, it was found that LPS‐RaMIg blasts internalize IL2 in a time‐ and temperature‐dependent manner very similar to that occurring in CTLL (T lineage) cells. LPS blasts, however, did not internalize IL2. LPS blasts were found to express 12 times less binding sites for anti‐IL2R monoclonal antibody (PC 61 monovalent Fab) as compared to LPS‐RaMIg blasts and at least 30 times less IL2 binding sites of high as well as of lower affinity. Second, with regard to the requirements for receptor expression, it was observed that either anti‐Ig or phorbol diester (phorbol‐12‐myristate 13‐acetate) can induce IL2R and IL2 responsiveness (proliferation assay) in LPS blasts but not in fresh B cells. Taken together these results (a) provide further evidence for the similarity of IL 2R function in activated B and T cells, (b) confirm that surface‐Ig cross‐linkage and phorbol‐12‐myristate 13‐acetate have similar effects on B cells and (c) suggest that LPS on the one hand, and phorbol‐12‐myristate 13‐acetate or anti‐Ig on the other provide complementary signals necessary for IL2R expression.
T cell nature of some lymphokine‐activated killer (LAK) cells. Frequency analysis of LAK precursors within human T cell populations and clonal analysis of LAK effector cells
Authors: Moretta Lorenzo , Pende Daniela , Cozzani Raffaella , Merli Annalisa , Bagnasco Marcello , Mingari Maria Cristina
Published: February 2007

The cell lineage of the lymphokine‐activated killer (LAK) cells has been reinvestigated. Both T and non‐T cells, isolated on the basis of rosette formation with sheep erythrocytes (E), generated LAK activity after 3–4 days of culture in recombinant interleukin 2 (rIL 2) in 8 different individuals tested. By applying a microculture technique which allows clonal expansion of virtually all E resetting T cells, we further analyzed the frequency of clonogenic LAK precursors within T cell populations. Approximately 1 of 25 T cells was found to be a LAK precursor. Moreover, microcultures with LAK activity lysed both the natural killer‐sensitive K562 cell line and the P815 target cells in the presence of phytohemagglutinin (PHA). Since cytolytic T lymphocytes capable of lysing P815 cells in the PHA‐dependent assay were approximately 1/3, it is evident that only a minor subset of cytolytic T lymphocyte precursors can acquire LAK activity even in the presence of large amounts of IL 2. Several LAK clones obtained by limiting dilution were further expanded and analyzed for their phenotypic and functional properties. Twelve out of 14 clones analyzed expressed the T3+ T11+ phenotype whereas 2 were T3− T11+. All had maintained their original cytolytic pattern; moreover, the large majority of the T3+ clones produced IL 2 and interferon‐γ following PHA stimulation.
Cytolytic T cell clones derived from liver tissue of patients with chronic hepatitis B
Authors: Hoffmann Robert M. , Pape Gerd R. , Richer Peter , Eisenburg Josef , Dohrmann Jutta , Zachoval Reinhart , Paumgartnei Gustav , Riethmüller Gert
Published: February 2007

To study the role of cell‐mediated immunity in chronic hepatitis B (cHB) we have cloned T cells from liver biopsies of 14 patients with cHB. As a first step, T cell lines were established from lymphocytes infiltrating the liver by culturing the biopsied specimens with autologous feeder cells and interleukin 2 (IL2). Fifty‐eight clones obtained by limiting dilution showed phenotypic stability over periods of 2–26 weeks. Of the 58 clones 50 were of the “cytotoxic/suppressor” T cell subset (CD8) as defined by the monoclonal antibody T811. Only 8 of 58 clones were of the “helper/inducer” phenotype (CD4) as defined by the monoclonal antibody T151. Functional studies on 9 clones (7 of CD8+ phenotype, 2 of CD4+ phenotype) revealed high cytotoxic activity of all of these clones in a lectin‐dependent cell‐mediated cytotoxicity assay reflecting the killing capacity of cytotoxic T lymphocytes. All 9 clones lacked significant natural killer activity, while two additional CD8+ clones that also expressed the VEP13 antigen showed significant natural killer activity. For none of the clones tested could killer cell activity (ADCC) be demonstrated.

The studies demonstrate that the clonal expansion of T lymphocytes from liver biopsies of patients with cHB in the absence of detectable antigen is possible. The propagation of in vivo activated cytolytic T lymphocytes points to an active role of these cells in the pathogenesis of this disease.
Signal transducing mechanisms involved in human T cell activation via surface T44 molecules. Comparison with signals transduced via the T cell receptor complex
Authors: Pantaleo Giuseppe , Olive Daniel , Harris David , Poggi Alessandro , Moretta Lorenzo , Moretta Alessandro
Published: February 2007

Antibodies against the T44 surface molecule have been shown to activate human T cells to produce interleukin 2. The role of Ca2+ in the triggering of the interleukin 2‐producing Jurkat T cell line by anti‐T44 monoclonal antibody has been investigated. We show that activation is initiated by an increase in the concentration of free cytoplasmic calcium ions [Ca2+]i. Subsequently, we have investigated the mechanism by which perturbation of T44 molecules induces increases of [Ca2+]i in Jurkat cells. We show that the anti‐T44‐mediated increase in [Ca2+]i can occur only in presence of extracellular Ca2+, since no increment is detectable when extracellular Ca2+ is depleted by EGTA. Thus, it appears that perturbation of T44 molecules, unlike that of T3‐Ti antigen receptor complex, fails to mobilize Ca2+ from intracellular stores. As inositol triphosphate is considered the putative mobilizer of Ca2+ from internal stores, we measured the levels of inositol triphosphate and of the other inositol phosphate compounds in Jurkat cells after stimulation with anti‐T44 antibodies. In contrast to the stimulation via the T3‐Ti antigen receptor complex, stimulation via T44 molecule does not induce increments of all three inositol phosphates. Taken together, these data indicate that stimulation mediated by the T44 molecule proceeds via a mechanism independent from the typical inositol lipid metabolism which does not involve mobilization of Ca2+ from internal stores.
Monoclonal BALB/c anti‐progesterone antibodies use family IX variable region heavy chain genes
Authors: Deverson Edward , Berek Claudia , Taussig Michael , Feinstein Arnold
Published: February 2007

Variable region nucleotide sequences and respective translated amino acid sequences for three heavy chains (DB3, 11/32 and 10/8) and two light chains (DB3 and 11/32) of monoclonal mouse IgG1 anti‐progesterone antibodies have been determined by primer extension mRNA sequencing. The three VH regions exhibit the same rarely observed VH IX gene family and have > 88% homology between them. Two associated light chain sequences are 95% homologous and belong to the VxI group. The N‐terminal twenty two amino acids of the x light chain of the third antibody 10/8 have been determined by automated protein sequencing and are identical to those of 11/32. Thus, these three monoclonal anti‐progesterones derived from separate fusions all use VHIX‐Vx1 gene combinations.
Purification and N‐terminal amino acid sequence of the human T lymphocyte CD2 (T11) surface antigen
Authors: Brown Marion H. , Krissansen Geoffrey W. , Totty Nicholas F. , Sewell William A. , Crumpton Michael J.
Published: February 2007

CD2 (the sheep erythrocyte receptor) is a surface antigen of human T lymphocytes. A role for CD2 in T cell function has been implicated from the observation that antibodies against CD2 are capable of transmitting both positive and negative signals for cell growth. Biochemically, the molecule has been identified as a broad band on sodium dodecyl sulfate (SDS)‐polyacrylamide gels of about 50–58 kDa. This communication demonstrates that CD2 contains N‐linked carbohydrate as endo‐β‐N‐acetylglucosaminidase F digestion reduced its apparent mol. mass to a compact band of 40 kDa. CD2 was purified from the T leukemia cell line J6 by immunoaffinity chromatography and preparative SDS‐polyacrylamide gel electrophoresis (PAGE). Four bands of 52, 54, 56 and 58 kDa could be distinguished in the immunoaffinity‐purified protein which formed a broad zone on SDS‐PAGE extending from about 45 to 58 kDa. Preparative SDS‐PAGE yielded a product suitable for determining the N‐terminal amino acid sequence. Assignments were made for the first 26 (excluding the 23rd) residues and the sequence identified a novel polypeptide.
Carrier‐specific T cells sufficient for the expression of multiple isotypes in B cell cultures
Authors: Kotloff Debra B. , Zitron Ian M. , Cebra John J.
Published: February 2007

A modified splenic fragment assay was used to assess the role of antigen‐specific helper T cells in B cell isotype expression. Limiting numbers of carrier‐specific helper T cells from lines or clones were injected along with a source of B cells into lethally irradiated unprimed recipients. The incidence of lodging of the T cell lines in recipient spleens at 18 h was determined by autoradiography to be 1.5 to 4.3% of the injected cells. These T cells were necessary and sufficient for the generation of T‐dependent B cell responses within splenic fragments cultured in vitro with specific antigen. A comparison of isotypic responses from splenic and Peyer's patch B cells generated with the same T cell population revealed that a high proportion of the response from Peyer's patch B cells consisted of IgA antibody exclusively (46–57%) while the percentage of such responses from splenic B cells was much lower (7–10%). Thus, the isotype pattern of the response reflected the B cell source. Experiments in which cloned hemocyanin‐specific T cells provided help to T‐depleted spleen cells within splenic fragments from athymic recipients indicated that a single specificity of helper T cell is both necessary and sufficient to support the generation of antibody responses consisting of multiple isotypes. Isotype‐specific T cells do not appear to be required in this system.
Human large granular lymphocytes induce immunoglobulin synthesis after bone marrow transplantation
Authors: Brenner Malcolm K. , Vyakarnam Anna , Reittie Joyce E. , Wimperis Jennifer Z. , Grob Jean Philippe , Hoffbrand A. Victor , Prentice H. Grant
Published: February 2007

Following T cell‐depleted bone marrow transplantation, helper T cell numbers remain depressed for some months. Nonetheless, functional B cells can be adoptively transferred to the recipients of such grafts, where they continue to secrete antibody. We now show that immunoglobulin production by these transferred B cells is induced by activated large granular lymphocytes (LGL) which circulate in the recipients in substantial numbers during the immediate post‐transplant period. The LGL are CD3 negative and therefore provide help in an antigen‐unlinked manner. Helper effects for autologous (donor) B cells are augmented by the addition of anti‐LFA‐2 (anti‐CD2) which appears to act by blocking recruitment of LGL inhibitory to developing B cells. In contrast antibody to the β chain of LFA‐1, which effectively reduces natural killer activity of LGL, does not influence their helper function. The peripheral blood LGL fraction thus contains both helper and cytotoxic activity, which can be distinguished by appropriate monoclonal antibodies.
Repertoire of the human T cell gamma genes: high frequency of nonfunctional transcripts in thymus and mature T cells
Authors: Yoshikai Yasunobu , Toyonaga Barry , Koga Yasuhiro , Kimura Nobuhiro , Griesser Henrik , Mak Tak W.
Published: February 2007

To further understand the structural diversity and function of the human T cell‐specific γ gene, 20 human γ gene cDNA from both thymocyte and peripheral blood T lymphocyte libraries were sequenced and analyzed. Evidence of greater germ‐line multiplicity and more extensive use of junctional flexibility, N‐region diversity and perhaps Dγ gene segment incorporation was observed. In spite of the larger γ gene repertoire found in humans compared to mice, the potential of the human γ gene message to encode a functional product appears to be severely limited. In addition to the extremely low levels of γ gene expression observed, each of the 20 γ gene cDNA exhibit some form of deleterious mutation defect. This is in sharp contrast to the finding that human and mouse T cell antigen receptor α and β messages isolated from various sources have functional coding potential in most cases. Thus, the role of the human T cell γ gene becomes even more uncertain than before.
A single amino acid substitution in influenza hemagglutinin abrogates recognition by monoclonal antibody and a spectrum of subtype‐specific L3T4+ T cell clones
Authors: Brian Thomas D. , Skehel John J. , Mills Kingston H. G. , Graham Christine M.
Published: February 2007

A fine specificity analysis of influenza hemagglutinin‐specific IAk‐restricted T cell clones using natural virus variants of the H3N2 subtype, monoclonal antibody‐selected variants and a synthetic peptide corresponding to a variable region of the HA1 polypeptide has provided insight on the structural basis for T cell recognition. A glycine to argine substitution at HA1 135 abrogates recognition by a panel of T cell clones which, according to their reactivity for natural virus variants, have different antigenic specificities: three clones recognize a synthetic peptide (HA1 residues 118–138) but fail to recognize the monoclonal antibody‐selected mutant (Gly135/Arg). There is no correlation, however, between differences in T cell specificity for the natural virus variants and HA1 amino acid sequences in this region. Two further clones have a reduced proliferative response to mutant recognize a completely different spectrum of natural variants, and only one of these clones recognizes the synthetic peptide. We speculate that influenza hemagglutinin employs a common strategy during antigenic drift to evade antibody recognition and effective processing/presentation to subtype‐specific T cell clones.
A meso‐scale analysis of lipid bilayers with the dissipative particle dynamics method: Thermally fluctuating interfaces
Authors: Sugii Taisuke , Takagi Shu , Matsumoto Yoichiro
Published: February 2007

We present a meso‐scale simulation of lipid bilayers with the dissipative particle dynamics (DPD) method. The spectrums of the thermal undulation are analysed and the bending rigidity of the lipid bilayers is calculated. In order to define the position of the membrane, we apply a definition of the interface which has been newly proposed by Kikugawa et al. (Comput. Fluids 2007; 36:69–76). We show the applicability of this method to the lipid bilayer system. By means of this definition, the roughness of the extracted interface can be varied and this effect is investigated. The spectral intensity is shown as a function of the undulatory wavenumber q. The spectral intensity in large‐q regions is affected by the roughness of the interface. However, we find that the spectral intensity in small‐q regions, where the bending rigidity can be calculated, is hardly affected. Moreover, the undulation spectrums show q−4 behaviour in small‐q regions, which agrees with the theoretical prediction. The effects of the size of the computational cell are also investigated. All spectrums obtained in the differently sized cells agree well, although the observable range of the wavenumber depends on the cell size. The bending rigidity calculated by spectral intensity from the largest cell is in good agreement with experiments and molecular dynamics simulations in the literature. Copyright © 2007 John Wiley & Sons, Ltd.
Development of a hybrid finite volume/element solver for incompressible flows
Authors: Tu Shuangzhang , Aliabadi Shahrouz
Published: February 2007

In this paper, we report our development of an implicit hybrid flow solver for the incompressible Navier–Stokes equations. The methodology is based on the pressure correction or projection method. A fractional step approach is used to obtain an intermediate velocity field by solving the original momentum equations with the matrix‐free implicit cell‐centred finite volume method. The Poisson equation derived from the fractional step approach is solved by the node‐based Galerkin finite element method for an auxiliary variable. The auxiliary variable is closely related to the real pressure and is used to update the velocity field and the pressure field. We store the velocity components at cell centres and the auxiliary variable at cell vertices, making the current solver a staggered‐mesh scheme. Numerical examples demonstrate the performance of the resulting hybrid scheme, such as the correct temporal convergence rates for both velocity and pressure, absence of unphysical pressure boundary layer, good convergence in steady‐state simulations and capability in predicting accurate drag, lift and Strouhal number in the flow around a circular cylinder. Copyright © 2007 John Wiley & Sons, Ltd.
Antiangiogenic therapy enhances the efficacy of transcatheter arterial embolization for hepatocellular carcinomas
Authors: Jiang Hongchi , Meng Qinghui , Tan Hongtao , Pan Shangha , Sun Bei , Xu Ruian , Sun Xueying
Published: February 2007

Transcatheter arterial embolization (TAE) is a well‐established technique for unresectable hepatic malignancies. However, TAE can temporally halt the growth of hepatic tumors by blocking their arterial supply, but often tumors rapidly develop collateral blood vessels via angiogenesis. We have previously demonstrated that intraportal delivery of adeno‐associated viral particles expressing angiostatin leads to long‐term expression of angiostatin capable of inhibiting angiogenesis and suppressing the outgrowth of tumors in the liver. Thus, we hypothesize that adeno‐associated virus (AAV)‐mediated antiangiogenic therapy could enhance the efficacy of TAE to combat liver cancers. To achieve this objective, we engineered a recombinant AAV vector encoding rat angiostatin. Intraportal delivery of this vector led to long term and stable transgenic expression of angiostatin locally in rat hepatocytes and suppressed the growth of CBRH7919 hepatocellular carcinomas established in rat livers by inhibiting formation of neovessels. Although TAE therapy led to necrosis of liver tumors and suppressed their growth, the neovessels of tumors were rapidly reformed 3 weeks after TAE. However, intraportal injection of AAV‐angiostatin inhibited the angiogenesis stimulated by TAE, synergized with TAE in suppressing growth of tumors established in livers and prolonged the survival of rats. In conclusion, these encouraging results warrant future investigation of the use of antiangiogenic therapy for enhancing the therapeutic efficacy of TAE to treat unresectable liver cancers. © 2007 Wiley‐Liss, Inc.
Gray scale transrectal ultrasonography of the prostate
Authors: Harada Kazuya , Igari Dairoku , Tanahashi Yoshikatsu
Published: February 2007

Gray scale transrectal ultrasonography provides refined visualization of the texture of the prostate and other intrapelvic organs. Diagnostic accuracy of the transrectal scan has been successfully registered at 91% in benign prostatic hyperplasia, 85% in cancer, 89% in prostatitis, and 88% in total prostatic scans. Furthermore, prostatic calculi were visible in the tomograms of both normal and abnormal prostates at a higher frequency than generally considered. Other applications of ultrasonic control, such as during transurethral resection or cryosurgery of the prostate and staging of bladder tumors, are profitable using the gray scale technique.
Lutembacher's syndrome: Recognition by echocardiography
Authors: Forman H. R. , Kotler M. N. , Segal B. L. , Parry W. R.
Published: February 2007

The typical echocardiographic features of mitral stenosis in association with an enlarged right ventricle and abnormal septal motion are generally consistent with pulmonary hypertension and functional tricuspid regurgitation. In the absence of clinical and echocardiographic features of pulmonary hypertension, the combination of mitral stenosis and “volume overload” of the right ventricle should alert the clinician to the diagnosis of Lutembacher's syndrome. This report discusses a patient with these echocardiographic findings in whom the diagnosis of Lutembacher's syndrome was confirmed by cardiac catheterization.
Looking back
Authors: Holmes Joseph H.
Published: February 2007

The following contribution from Dr. Holmes, founding editor of JCU, is the first of a series of short articles that will be published on the history of ultrasound technique. It is the firm belief of the present editor that a thorough appreciation of our roots is essential for understanding where we are going. How fortunate we are to have many of the real pioneers with us to relate their experiences.
An analysis of pancreatic sonography in suspected pancreatic disease
Authors: Arger Peter H. , Mulhern Charles B. , Bonavita John A. , Stauffer Dorothy M. , Hale John
Published: February 2007

To assess the value of pancreatic sonography in patients suspected of having pancreatic disease, our first 500 pancreatic examinations using gray scale imaging were reviewed in a prospective manner without clinical information. Various parameters of each examination were recorded. The pancreas was localized by its relationships to surrounding vessels and the duodenum. The ability to define the head, body, and tail of the pancreas as well as anterior‐posterior size measurements were noted and recorded. A retrospective clinical pathologic follow‐up was then carried out and correlated with the1 ultrasonic findings. Four categories of patients were identified. The features seen in pancreatic ultrasonography of the entire group, as well as those seen in the individual categories, were analyzed. This analysis indicates that pancreatic sonography can be used in patients suspected of having pancreatic disease, defining both normal and abnormal pancreas. A high index of suspicion for the type of abnormality present can be achieved.
Applications of real‐time ultrasound in obstetrics: The linear and dynamically focused phased arrays
Authors: Morgan Carlisle L. , Trought William S. , Haney Arthur , Clark William M.
Published: February 2007

Real‐time ultrasound is a dynamic imaging technique that allows in utero orientation to the fetus. It permits rapid and efficient examination of fetal anatomy and provides a dynamic assessment of fetal well‐being. The energy dissipation can be comparable to that in conventional ultrasonic B‐mode scanning. We have used both linear and dynamically focused phased arrays for fetal examinations in conjunction with conventional gray scale B‐mode scanners. The sophisticated phased‐array real‐time systems have demonstrated higher resolution and an improved gray scale as compared with the linear arrays. Applications of real‐time ultrasound in obstetrics are discussed, and appropriate clinical examples are cited that illustrate the value of the technique for study of both normal and abnormal fetal development. We believe that this technique is the most sensitive method of detecting intrauterine fetal demise. The relative advantages and disadvantages of linear and dynamically focused phased arrays in obstetric evaluation are considered.
Hepatic arteries and the parallel‐channel sign
Authors: Willi Ulrich V. , Teele Rita Littlewood
Published: February 2007

The sonographic parallel‐channel sign is not pathognomonic of dilatation of the biliary tree. Often, the so‐called parallel channel is a hepatic artery. The differentiation between a bile duct and a hepatic artery is usually possible with good sonographic technique.
Intrauterine pseudogestational sac in ectopic pregnancy
Authors: Mueller Charles E.
Published: February 2007

Ultrasonic diagnosis of ectopic pregnancy has been thought to depend on exclusion of intrauterine pregnancy on the basis of absence of an intrauterine gestational sac. Two cases illustrating intrauterine echoes suggesting a gestational sac associated with ectopic pregnancy and a plausible explanation for this phenomenon are presented. Because of this and the rare possibility of coexisting intrauterine and extrauterine pregnancies, the ultrasonographer must be wary of dismissing the possibility of an ectopic pregnancy because of an intrauterine gestational sac, whether real or apparent.
Genetic amniocentesis in multiple pregnancy
Authors: Wolf Deborah A. , Scheible F. William , Young Philip E. , Matson Melinda R.
Published: February 2007

Eleven cases of twin pregnancy presenting for genetic diagnosis in the second trimester are reported. In all 11 cases, a correct chromosomal diagnosis was made on each of the twins. The technique used required only ultrasound and Evan's blue dye for direction of the amniocentesis. Amniography was not performed. The technique used is described in detail, and its advantages over more standard techniques are described.
The quadratus lumborum muscle: A possible source of confusion in sonographic evaluation of the retroperitoneum
Authors: Callen Peter W. , Filly Roy A. , Marks William M.
Published: February 2007

The quadratus lumborum muscle has been noted to appear as a hypoechoic structure on sonograms of the abdomen. On occasion its appearance may simulate a pathologic fluid collection such as an abscess or retroperitoneal hematoma. Illustrative examples of this confusing appearance, as well as ways of avoiding this potential pitfall, are presented.
Upright exercise echocardiography
Authors: Amon K. Wray , Crawford Michael H.
Published: February 2007

A simple technique for obtaining high‐quality echocardiograms of the left ventricle during upright bicycle exercise is described. The use of this method has resulted in left ventricular dimension data that are consistent with the results of studies in conscious, previously instrumented dogs during running. Careful subject selection is important, however, as only 1 of 5 normal subjects was found suitable for these studies. Therefore, we believe that upright exercise echocardiography is feasible in selected subjects and provides useful physiologic information about left ventricular performance during exercise.
The posterior thoracic approach in echocardiography
Authors: Parameswaran R. , Carr Vincent F. , Rao Adiraju V. R. , Goldberg Harry
Published: February 2007

Echocardiograms were recorded using a left posterior thoracic approach in 17 patients with left pleural effusion. Comparison of these records with those obtained using the conventional technique in the same patients revealed that the left posterior thoracic approach yielded records of adequate quality in all patients. The mitral valve, the left ventricle, and the posterior pericardium were well defined. In 10 patients in whom pericardial effusion was also present, the posterior approach facilitated clear separation of the pleural and pericardial effusions. A major limitation of the posterior technique appears to be inability to record the aortic root, the aortic valve, and the left atrium.
Ethylene glycol‐water mixtures for use in ultrasound test objects
Authors: Goldstein Albert , Langrill Lawrence N.
Published: February 2007

Ethylene glycol—water mixtures have been found suitable for use in ultrasound test objects. A plot of the required percentage of ethylene glycol with room temperature for an acoustic velocity of 1540 m/sec is presented to aid the clinical user. The velocity measurements performed are shown to be dominated by near‐field transient diffraction effects. A 30 percent ethylene glycol—water mixture has been found to have a constant acoustic velocity of 1638 ± 3.5 m/sec over a wide temperature range (15.6°C–38.4°C). This mixture is suitable for a test object velocity standard. Proper use of the A.I.U.M. 100‐mm test object is discussed.
Parathyroid sonography: A useful aid to preoperative localization
Authors: Duffy Peter , Picker Richard H. , Duffield Sue , Reeve Thomas , Hewlett Sue
Published: February 2007

Parathyroid sonography was used to identify 19 of 23 glands enlarged to over 5 mm in transverse diameter in 22 patients presenting with hyperparathyroidism, both primary and secondary. The false positive and false negative rates were 5 percent and 6 percent, respectively.
Sonography of bilharzial masses of the scrotum
Authors: Abul‐Khair Mahmoud H. , Arafa Nabil M. , Sobeih Abdalla M. , Taalab Abdel A. A.
Published: February 2007

Five patients with bilharzial masses of the spermatic cord were studied. Clinical examination and laboratory tests were performed. Plain radiology was used in 1 case to illustrate the calcified masses. Sonography in these patients gives a characteristic picture, with echogenic multiple masses with posterior shadowing. Operative excision of these masses was performed, and histopathological examination was carried out to verify the diagnosis.
Role of ultrasound in the diagnosis of abdominal hydatid disease
Authors: Itzchak Yacov , Rubinstein Zalman , Heyman Zahava , Gerzof Stephan
Published: February 2007

Experience with the use of ultrasound for investigating hydatid disease of the abdomen is reported. The presence of daughter cysts within the parent cyst gives a pathognomonic sonographic picture, whether the cyst is single or multiple. The presence of single cysts without daughter cysts is still a diagnostic problem, unless calcification is seen. Associated secondary infection changes the picture to one of a nonspecific abscess, and only the presence of additional cysts can give a clue about the etiology.
Hydronephrosis in children: Narrowing the differential diagnosis with ultrasound
Authors: Chopra Amrit , Teele Rita Littlewood
Published: February 2007

Twenty patients with hydronephrosis in whom examination with ultrasound was helpful in defining the extent of dilation of the collecting system are presented. Thirteen patients had hydronephrosis due to obstruction at the ureteropelvic junction, six had obstruction of the ureterovesical junction from various causes, and one had massive bilateral vesicoureteral reflux. The diagnosis of high ureteral obstruction as opposed to obstruction or reflux at the ureterovesical junction was based on visualizing a dilated ureter in the latter two groups.
M‐mode and cross‐sectional echocardiographic diagnosis of right ventricular cavity masses
Authors: Krivokapich Janine , Warren Sanford E. , Child John S. , Kaufman Joseph A. , Vieweg Walter V. , Hagan Arthur D.
Published: February 2007

Two patients with metastatic carcinoma (one cervical and one testicular) in whom echocardiography was instrumental in diagnosing a right ventricular cavity mass are presented. In the first case the M‐mode echocardiogram revealed dense echoes in the right ventricle and right ventricular outflow tract during systole and diastole. Surgical confirmation of the mass lesion was obtained. The second case also revealed abnormal echoes in the right ventricle and right ventricular outflow tract, but they were less dense and distinct. Two‐dimensional echocardiography clearly delineated a highly mobile mass of tissue in the right ventricle which corresponded to the necropsy findings.
Ultrasonic characteristics of bilomas
Authors: Zegel Harry G. , Kurtz Alfred B. , Perlmutter Gordon S. , Goldberg Barry B.
Published: February 2007

The ultrasonic characteristics of bilomas are reviewed in five patients, one of whom was also studied with computed x‐ray tomography. Certain features not previously reported should aid in differentiating bilomas from other intra‐abdominal fluid collections.
Echocardiographic analysis of systolic and diastolic left ventricular wall motion during transient myocardial ischemia
Authors: Conetta Donald A. , Christie Leonard G. , Nichols Wilmer W. , Feldman Robert L. , Pepine Carl J. , Conti C. Richard
Published: February 2007

Left ventricular (LV) wall motion (anterior and posterior) and simultaneous LV pressure were recorded during 30‐second left anterior descending (LAD) or circumflex (CX) coronary artery occlusions in open‐chest dogs to provide an echocardiographic model of the evolution of wall motion changes during myocardial ischemia. Prominent diastolic echocardiographic motion changes of progressive decrease in LV wall rapid‐filling velocities (RFS), slow‐filling velocities (SFS), and increased end‐diastolic diameter were accompanied by a marked increase in initial and end‐diastolic pressures (150% and 70%, respectively; all p < 0.05). Early (within ten seconds) and progressive decrease in rate (SES), amplitude (E), and duration (TTR) of systolic motion were noted with an increased systolic diameter (p < 0.05). Ischemic regions developed a characteristic pattern with early relaxation followed by a diastolic inward motion (DIM). These observations confirm and extend other investigators' findings on the motion of the ischemic myocardium and may be applicable to responses to transient myocardial ischemia noted in humans.
Normal left renal vein mimicking left renal artery aneurysm
Authors: Kurtz Alfred B. , Dubbins Paul A. , Zegel Harry G. , Cole‐Beuglet Catherine , Goldberg Barry B.
Published: February 2007

On transverse ultrasound scans a small number of patients with a paucity of retroperitoneal fat show an initial false impression of a left renal artery aneurysm due to the confluence of two normal findings. The left renal vein is unusually prominent from the hilum of the left kidney to the area between the superior mesenteric artery and the aorta; and part of the normal aortic wall, adjacent to the left renal vein, is incompletely imaged. Explanations for the prominence in the left renal vein and the partial visualization of the aortic wall are discussed, and various maneuvers that allow for accurate identification of both are described. The use of this analysis should prevent the incorrect diagnosis of a left renal artery aneurysm, which might lead to more invasive diagnostic procedures.
Rapid oral hydration: A cause of pelvic fluid collections at sonography
Authors: Sukov Richard J. , Whitcomb Mary Jo
Published: February 2007

In a controlled study, rapid oral hydration was found to result in sonographically visible pelvic fluid collections in six of 12 healthy women volunteers. These pelvic fluid collections were in many ways indistinguishable from those seen in a variety of pelvic diseases. An awareness of this association should result in a further reduction of false‐positive diagnoses at pelvic sonography.
Beat‐to‐beat variation in echocardiographic measurements of left ventricular dimensions and function
Authors: Bett John H. N. , Dryburgh Lawrence G.
Published: February 2007

M‐mode echocardiography was used to explore the extent of spontaneous variation in left ventricular dimensions and indices of systolic and diastolic function. Extended records made in 26 subjects at rest were digitized and analyzed by computer. We found considerable beat‐to‐beat variation, in that measurements of five or more consecutive cycles were necessary to provide representative values for minor axis dimensions, while the degree of scatter for derived indices of function was greater. This has to be recognized when serial echocardiography is used to study the progress of disease or the effects of treatment.