bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic Mapping of The Chicken Embryonic Thymic Microenvironment Developing Within an Organ Culture System
Authors: Davidson Natalie J. , Boyd Richard L.
Published: June 2008

The chicken thymic microenvironment, as it developed in an embryonic thymus organ
culture system, was phenotypically mapped using a panel of mAb defining both
epithelial and nonepithelial stromal cell antigens. We have previously reported that
thymocyte proliferation and differentiation will proceed for up to 6–8 days in thymus
organ culture, hence demonstrating the functional integrity of the thymic
microenvironment in vitro. During this time, the stromal component reflected that of the
normal embryo with cortical and medullary epithelial areas readily identifiable by both
morphology and surface‐antigen expression. An abundance of subcapsular and cortical
epithelial antigens was detected in the cultured thymus, particularly those normally
expressed by the epithelium lining the capsule, trabeculae, and vascular regions (type
epithelium) in the adult and embryonic thymus. Medullary epithelial antigens
developed in organ culture, although were present in lower frequency than observed in
the age‐matched embryonic thymus. MHC class II expression by both epithelial and
nonepithelial cells was maintained at high levels throughout the culture period. With
increasing time in culture, the ratio of epithelial to nonepithelial cells decreased,
concurrent with a decrease in thymocyte frequency and suggestive of a bidirectional
interaction between these two cell types. Thus, a functionally intact thymic
microenvironment appears to be maintained in embryonic thymus organ culture, a
model that is currently being exploited to assess the role of stromal antigens, as defined
by our mAb, in the process of thymopoiesis.
Expression of λ and K Genes Can Occur in all B Cellsand is Initiated Around the Same Pre‐B‐CellDevelopmental Stage
Authors: Doglio Lynn , Kim Joo Yeun , Bozek Grazyna , Storb Ursula
Published: June 2008

Transgenic mice that carry a λ2 transgene under the control of the Vλ2 promoter and the
Eλ2‐4 enhancer (λ2Eλ mice) are described. A high proportion of B cells in the spleen and
the bone marrow express the λ transgene on the cell membrane. λ2 protein is synthesized
by all λ2Eλ‐derived spleen B‐cell hybridomas that have retained the transgene, suggesting
that all B cells have the ability to express λ genes. Feedback inhibition of endogenous K‐gene
rearrangement is significant, but not complete. The results are similar to those with
transgenic mice expressing the same λ2 transgene under the control of the heavy‐chain
enhancer (λ2EH mice). Although the λ2EH transgene is expressed before the λ2Eλ
transgene, feedback inhibition seems to occur at about the same stage of B‐cell development,
regardless of the timing of expression of the λ transgenes. Apparently, feedback is not
necessarily coincident with the assembly of a heavy‐chain/light‐chain complex in pre‐B
cells. Expression of λ in the normal fetal liver coincides with the expression of K; thus, it
appears that λ‐gene transcription is not delayed. The differential rearrangement of K and λ
genes is discussed in the light of these findings.
Interleukin Gene Expression in Mouse PreimplantationDevelopment
Authors: Gerwin Nicole , Jia Gui-Quan , Kulbacki Robert , Gutierrez-Ramos José C.
Published: June 2008

Control of growth and differentiation during mammalian embryogenesis is regulated by
growth factors from embryonic and/or maternal sources. Cytokines are polypeptide growth
factors that are released by a variety of activated immune and nonimmune cells. To identify
novel members of the cytokine family that could be involved in the growth and
differentiation of the preimplantation embryo, we studied the expression pattern of several
genes encoding cytokines and their receptors during mouse preimplantation development
in vitro We found that poly(A)+ mRNAs for IL‐1, IL‐3, IL‐6, IL‐7, and TNFα are
differentially expressed at several stages of mouse preimplantation development, including
unfertilized oocytes. Immunostaining of preimplantation embryos using monoclonal antibodies
specific for several cytokines and their receptors revealed that at least some of these
mRNAs are translated into mature proteins during preimplantation development (IL‐1,
IL‐6, and TNFα). Positive staining for IL‐1 and IL‐6 receptors was also detected at these
stages of development. The controlled expression of these “inflammatory‐type” cytokines
and their receptors suggests a role for these growth factors during the early phases of mouse
ontogeny.
Human Germinal Center CD4+ CD57+ T Cells ActDifferently On B Cells Than Do Classical T‐Helper Cells
Authors: Bouzahzah Farida , Bosseloir Alain , Heinen Ernst , Simar Léon J.
Published: June 2008

We have isolated two subtypes of helper T cells from human tonsils: CD4+ CD57+ cells,
mostly located in the germinal center (GC), and CD4+ CD57- cells, distributed through the
interfollicular areas but also present in the GC. In a functional study, we have compared the
capacities of these T‐cell subtypes to stimulate B cells in cocultures. In order to block T‐cell
proliferation while maintaining their activation level, we pretreated isolated T cells with
mitomycin C prior to culture in the presence of B cells and added polyclonal activators such
as PHA and Con A, combined or not with IL‐2. Contrary to CD4+ CD57- cells,
CD4+ CD57+ cells did not markedly enhance B‐cell proliferation. Even when sIgD-B cells
typical of germinal center cells were tested, the CD4 CD57 cells had no significant effect.
This is in accordance with the location of these cells: They mainly occupy the light zones
of the GC where few B cells divide. Even when added to preactivated, actively proliferating
cells, CD4+ CD57+ cells failed to modulate B‐cell multiplication. On the supernatants of
B‐cell‐T‐cell cocultures, we examined by the ELISA technique the effect of T cells on Ig
synthesis. Contrary to CD57- T cells, whose effect was strong, CD57+ T cells weakly
stimulated Ig synthesis. More IgM than IgG was generally found. Because CD57 antigen is
a typical marker of natural killer cells, we tested the cytolytic activity of tonsillar
CD4+ CD57+ cells on K562 target cells. Unlike NK cells, neither CD4+CD57+ nor
CD4+ CD57- cells exhibit any cytotoxicity. Thus, germinal center CD4+ CD57+ cells are not
cytolytic and do not strongly stimulate either B‐cell proliferation or Ig secretion.
CD4+ CD57- cells, however, enhance B‐cell proliferation and differentiation, thus acting
like the classical helper cells of the T‐dependent areas.
T‐Cell Development in Early Partially DecapitatedChicken Embryos
Authors: Moreno Javier , Vicente Angeles , Varas Alberto , Zapata Agustín G.
Published: June 2008

We have evaluated the immunohistological and cytofluorometric changes that occur in the
thymus of chicken embryos partially decapitated at 33‐38 hr of incubation (DCx embryos)
in an attempt to analyze possible neuroendocrinological influences on T‐cell differentiation
and, indirectly, the ontogeny of the so‐called neuroendocrine‐immune network. The
thymus of DCx embryos shows important variations that profoundly and selectively affect
different T‐cell subsets, but not the nonlymphoid cell components of thymic stroma. These
modifications include the accumulation of cell precursors, mainly DN (CD4- CD8-) cells
and immature CD8high CD4- cells, which expand but do not differentiate, resulting in an
extreme decline of both DP (CD4+ CD8+) cells and TcR c‐expressing cells. Accordingly,
both subcapsulary and outer cortex increase in size, whereas the deep cortex and principally
the thymic medulla almost disappear in DCx embryos. In contrast, other T‐cell subsets of
DCx embryos, largely CDgglowCD4- cells and TcR γδ‐expressing cells do not undergo
significant variations throughout thymic ontogeny.
Enrichment of Early Fetal‐Liver Hemopoietic Stem Cellsof the Rat Using Monoclonal Antibodies Against theTransferrin Receptor, Thy‐1, and MRC‐Oχ82
Authors: Crook Kenneth , Hunt Simon V.
Published: June 2008

Fetal livers from inbred rat fetuses at 14 days′ gestation were dispersed into a single‐cell
suspension by physical disruption and collagenase digestion. Pluripotent stem cells were
characterized and partially purified by a combination of monoclonal antibodies. These
included CD71 (anti‐transferrin receptor, MRC‐Oχ26, used for rosetting), Cdw90 (anti‐
Thy‐1, MRC‐Oχ7), and the newly described MRC‐Oχ82 (reacting with myeloid cells in
peritoneal exudate), employed in FACS sorting. Enrichment was monitored by long‐term
reconstitution of lethally irradiated congenic rats genetically distinguishable from the donor
by an allelomorphic variant of the CD45 cell‐surface antigen. At intervals from 3 months
to 1 year, lymph‐node cells and peritoneal exudate cells were biopsied for analysis by
two‐color flow cytometry‐one color to determine donor origin, the other to identify Th cell
(CD4+), Tc cell (CD8+), B cell (sIg+ or CD45RC+ ), neutrophil (Oχ82 + or Oχ43‐ ), and
macrophage (Oχ43+) compartments. The degree of chimaerism was taken as the read out
of stem‐cell activity. No significant differentials between lymph‐node and peritoneal
exudate chimaerisms were detected in any of the recipients; therefore, the enrichment
procedure revealed only pluripotent cells, not stem cells of restricted potency. All recovered
stem‐cell activity was in the Oχ26(CD71)‐negative, Oχ7(CDw90)‐positive, Oχ82‐positive
fraction. In the optimum case, an enrichment of very roughly 200‐fold in cell‐for‐cell
activity was obtained.

Rat bone‐marrow colony‐forming units in the spleen (CFUs‐12) were found to lack the
surface antigens recognized by the monoclonal antibodies CD53 (MRC‐Oχ44), MRC‐Oχ39,
MRC‐Oχ59, and 144.2.15. These would provide a strategy for their enrichment by
depletion.
Mechanisms Involved in the Binding of Thymocytes to Rat Thymic Dendritic Cells
Authors: Čolić Miodrag , Ilić Vesna , Pavlović Milo' D. , Tamatani Takuya , Miyasaka Masayuki
Published: June 2008

The effects of monoclonal antibodies (mAbs) to cell‐surface molecules, divalent cations,
and various cell‐signaling and metabolic inhibitors on the binding of thymocytes to rat
thymic dendritic cells (TDC) were studied using a rosette assay. It was found that TDC/thymocyte adhesion was stronger and faster at 37℃ than at 4℃. Flow cytometric analysis
demonstrated that bound thymocytes were predominantly CD4+CD8+ and CD4+CD8-, but
in comparison to the phenotype of whole thymocytes, they were enriched in the mature
TCRαβhi subset. The binding of thymocytes to TDC at 37℃ was almost completely
dependent on Ca2+ and Mg2+ and partly on an intact cytoskeleton and calmodulin‐dependent
protein kinase. The adhesion was independent of new protein synthesis and
the activities of protein kinases A and C, tyrosine kinases, as well as phosphotyrosine protein
phosphatases. The TDC/thymocyte adhesion at 37℃ was partly blocked by anti‐LFA‐1
(WT.1), anti‐CD18 (WT.3), and anti‐ICAM‐1 (1A29) mAb. MAbs to class II MHC (OX‐3 and
OX‐6), CD4 (W3/25), CD8 (OX‐8), and αβTCR (R73) stimulated the adhesion via an LFA‐1‐dependent pathway, whereas an anti‐CD45 mAb (G3C5) stimulated the rosette formation
independently of LFA‐1. MAbs to CD2 (OX‐34), CD11b (ED7), CD11b/c (OX‐42), and
class I MHC (OX‐18) were without significant effects on the adhesion process.
Presence of Germline and Full‐Length IgA RNA Transcripts Among Peritoneal B‐1 Cells
Authors: De Waard Rick , Dammers Peter M. , Tung James W. , Kantor Aaron B. , Wilshire Jennifer A. , Bos Nicolaas A. , Herzenberg Leonore A. , Kroese Frans G. M.
Published: June 2008

Next to conventional B cells (or B‐2 cells), peritoneal B‐1 cells have been shown to contribute significantly to the production of IgA‐secreting plasma cells in the gut. Evidence for this was mainly based on studies comprising manipulated animals, including lethally X‐irradiated and transgenic mice. To examine the ability of peritoneal B‐1 cells from untreated mice to switch actively to IgA in vivo, we performed RT‐PCR analysis on FACS‐sorted peritoneal B‐cell subsets from untreated BALB/c mice in order to examine the presence of germline Cα mRNA and mature Cα mRNA transcripts. Germline Cα and mature Cα transcripts were readily
detectable in peritoneal B‐1 cells (defined as IgMbright/IgDdull), but not, or very little, in peritoneal B‐2 cells (defined as IgMdull/IgDbright). Moreover, by subdividing the B‐l‐cell population in CD5+ B‐1a cells and CD5- B‐1b cells, it was shown that in vivo expression of germline Cα and mature Cα transcripts was largely restricted to the B‐1b‐cell lineage. These results indicate that peritoneal B‐1 cells indeed are capable to switch to IgA under normal physiological conditions and hereby further support the view that B‐1 cells contribute significantly to the mucosal IgA response, albeit this function appears to be restricted to the B‐1b‐cell subset.
Epidermal Growth Factor Modulates Fetal Thymocyte Growth and Differentiation
Authors: Freitas Claudia S. , Dalmau Sergio R. , Kovary Karla , Savino Wilson
Published: June 2008

In the present study, we used the fetal organ culture (FTOC) technique in order to study a
putative effect of epidermal growth factor (EGF) on the thymus ontogeny. Functional EGF
receptors and more recently the EGF molecule itself, respectively, on the membrane of epithelial
components of thymic stroma and on a few thymocytes in adult thymus, had been reported in the
literature. We could observe a dose‐dependent decrease in cellularity and a progressive retention
of thymocytes in the double‐negative (CD4-/CD8-) stage of differentiation when exogenous
EGF was added. Epidermal growth factor interfered with both fetal stroma growth and
thymocyte development at a precise moment, that is, in the passage from double‐negative to the
double‐positive (CD4+/CD8+) stage. After a 7‐day FTOC in the presence of EGF, most cells
recovered were Thy‐1.2+, c‐kit+, TSA1-/int, CD3-, and one of CD44high/CD25int, CD44-/CD25int, or CD44-/CD25-. Some developed into γδTCR+ cells with a mature (CD3+)
phenotype, but not into αβTCR+ thymocytes. It seems that EGF addition makes the cultures
"nonpermissible" for αβTCR+ thymocyte generation. We report here the presence of a high Mr
"EGF‐like" molecule on the membrane of fetal thymocytes, which role in the observed effects
is under investigation. Further biochemical characterization of this molecule is still required,
because its presence was only evidenced on the basis of its antigenicity.
CD40 in Clinical Inflammation: From Multiple Sclerosis to Atherosclerosis
Authors: Laman Jon D. , De Boer Mark , Hart Bert A. ′T
Published: June 2008

The interactions of CD40 and CD40L have been known for some time to critically regulate B‐cell responses
with respect to proliferation, isotype switching, antibody production, and memory formation.
More recent findings demonstrated that CD40 can be expressed on several other antigen‐presenting cell (APC) types
such as macrophages, dendritic cells, and fibroblasts. This expression of CD40 regulates T‐cell‐APC interaction and
is centrally involved in a wide array of inflammatory events. Here, currently available data are reviewed
demonstrating that CD40‐ CD40L interactions are operational in two chronic inflammatory clinical conditions,
namely, multiple sclerosis and atherosclerosis. The functional correlates of these interactions are discussed in the
light of recent other findings, shedding light on the multiple effects of CD40‐ CD40L interactions.
In-Vitro Differentiation of Mature Dendritic Cells From Human Blood Monocytes
Authors: Gieseler Robert , Heise Dirk , Soruri Afsaneh , Schwartz Peter , Peters J. Hinrich
Published: June 2008

Representing the most potent antigen‐presenting cells, dendritic cells (DC) can now be generated from human blood monocytes. We recently presented a novel protocol employing GM‐CSF, IL‐4, and IFN‐γ to differentiate monocyte‐derived DC in vitro. Here, such cells are characterized in detail. Cells in culture exhibited both dendritic and veiled morphologies, the former being adherent and the latter suspended. Phenotypically, they were CD1a-/dim, CD11a+, CD11b++, CD11c+, CD14dim/-, CD16a-/dim, CD18+, CD32dim/-, CD33+, CD40+, CD45R0+, CD50+, CD54+, CD64-/dim, CD68+, CD71+, CD80dim, CD86+/++, MHC class I++/+++ HLA‐DR++/+++
HLA‐DP+, and HLA‐DQ+. The DC stimulated a strong allogeneic T‐cell response, and further evidence for their autologous antigen‐specific stimulation is discussed. Although resembling a mature CD 11c+CD45R0+ blood DC subset identified earlier, their differentiation in the presence of the Thl and Th2 cytokines IFN‐γ and IL‐4 indicates that these DC may conform to mature mucosal DC.
Tonsil Stromal‐Cell Lines Expressing FDC‐Like Properties: Isolation, Characterization, and Interaction with B Lymphocytes
Authors: Skibinski Grzegorz , Skibinska Anna , Deckers Martine , James Keith
Published: June 2008

The microenvironment of secondary lymphoid organs consists of two major populations of cells, the lymphoid cells and a population of stromal cells that contribute to both tissue architecture and function. Interactions of both populations are essential for the development and control of humoral immune responses. In this study, stromal‐cell preparations were obtained by a multistage process. This involved culturing 300‐400‐μm slices of human tonsil for 6‐8 days at 25°C, trypsin digestion of the residual explant, followed by CD45‐positive‐cell depletion using magnetic beads, and a final period of culture for 4 days to remove remaining nonadherent cells.
Phenotypifig with a panel of monoclonal antibodies revealed that the cells express HLA‐DR, CD54 (ICAM‐1), CD44, but no CD45 nor a range of other markers for epithelial and endothelial cells. Immunoassays of supernatants from stromal cells revealed that IL‐6 was produced constitutively, and its production was increased by treatment with TNF‐α and IFN‐γ. In contrast IL‐1, IL‐2, IL‐4, IL‐7, IL‐8, IL‐10, IL‐12, TNF‐α, and IFNγ were not produced. Functional tests showed that these cells express follicular dendritic cell‐like properties. Coculturing of tonsilar B
cells with stromal cells resulted in enhanced proliferation and also led to increased production of immunoglobulins and IL‐6, suggesting crucial signaling between these populations.
Hormonal Regulation of Uterine Macrophages
Authors: Hunt Joan S. , Miller Lance , Platt Jeralyn Sue
Published: June 2008

Macrophages are major cellular inhabitants of cycling and pregnant mammalian uteri. Their densities and patterns of tissue distribution in this organ fluctuate in concert with levels of circulating female sex steroid hormones, estrogens and progesterone, and their production of various effector molecules also may be hormonally regulated. Hormonal control may be achieved by direct binding to receptors or by indirect pathways where hormones modulate production of various autocrine and paracrine cytokines and growth factors that then target to
resident macrophages and influence their secretory profiles. In this paper, we marshall evidence supporting the concept that progesterone acts as a powerful negative regulator of these versatile cells, reducing their migration into the uterus and impairing their ability to produce potent effector molecules such as nitric oxide that could interfere with the success of pregnancy.
Role of Prolactin and Growth Hormone on Thymus Physiology
Authors: De Mello-Coelho Valéria , Savino Wilson , Postel-Vinay Marie-Catherine , Dardenne Mireille
Published: June 2008

Intrathymic T‐cell differentiation is under the control of the thymic microenvironment, which acts on maturing thymocytes via membrane as well as soluble products. Increasing data show that this process can be modulated by classical hormones, as exemplified herein by prolactin (PRL) and growth hormone (GH), largely secreted by the pituitary gland.

Both PRL and GH stimulate the secretion of thymulin, a thymic hormone produced by thymic epithelial cells. Conversely, low levels of circulating thymulin parallel hypopituitary states. Interestingly, the enhancing effects of GH on thymulin seem to be mediated by insulinlike growth factor (IGF‐1) since they can be abrogated with anti‐IGF‐1 or anti‐IGF‐l‐receptor antibodies. The influence of PRL and GH on the thymic epithelium is pleiotropic: PRL enhances in vivo the expression of high‐molecular‐weight cytokeratins and stimulates in vitro TEC proliferation, an effect that is shared by GH and IGF‐1.

Differentiating T cells are also targets for the intrathymic action of PRL and GH. In vivo inoculation of a rat pituitary cell line into old rats results in restoration of the thymus, including differentiation of CD4-CD8- thymocytes into CD4+CD8+ cells. Furthermore, PRL may regulate the maintenance of thymocyte viability during the double‐positive stage of thymocyte differentiation.

Injections of GH into aging mice increase total thymocyte numbers and the percentage of CD3‐bearing cells, as well as the Concanavalin‐A mitogenic response and IL‐6 production by thymocytes. Interestingly, similar findings are observed in animals treated with IGF‐1. Lastly, the thymic hypoplasia observed in dwarf mice can be reversed with GH treatment.

In keeping with the data summarized earlier is the detection of receptors for PRL and GH on both thymocytes and thymic epithelial cells. Importantly, recent studies indicate that both cell types can produce PRL and GH intrathymically. Similarly, production of IGF‐1 and expression of a corresponding receptor has also been demonstrated.

In conclusion, these data strongly indicate that the thymus is physiologically under control of pituitary hormones PRL and GH. In addition to the classical endocrine pathway, paracrine and
autocrine circuits are probably implicated in such control.
Immune Response to “Self” Lens in Xenopus laevisEnucleated during Larval Life
Authors: Enomoto Takeshi , Tochinai Shin
Published: June 2008

We have reinvestigated an important issue in the amphibian immunology that has not been
settled for years since the pioneer work of Triplett, concerning the necessity of being exposed
to organ‐specific antigens early in development. It was found that syngeneic lenses were
rejected by frogs, Xenopus laevis, that had been enucleated (eye removed) during early larval
life. This rejection did not occur in intact frogs or in those enucleated in later larval or adult
life. Whereas the splenocytes from intact frogs did not proliferate in response to a co‐cultured
syngeneic lens, those from frogs that had been enucleated at any of the larval stages, or even
after metamorphosis, proliferated intensely. Both of these responses were shown to be thymus‐
dependent. In conclusion, it was demonstrated that the frog immune system rejected
even syngeheic lenses by enucleation in early larval life and that it began to recognize the
syngeneic lenses by lymphoid proliferation after enucleation, even in later life.
Defective Chemokine Production in T‐Leukemia CellLines and its Possible Functional Role
Authors: Ivanoff Jyrki , Ivanoff Anna , Sundqvist Karl-Gösta
Published: June 2008

Peripheral blood lymphocytes and T‐cell clones produced nanogram quantities of the chemokines
RANTES, MIP‐lα, MIP‐lβ, MCP‐l, IL‐8 and GRO‐α as well as the motogenic
cytokine HGF. In contrast, various T‐leukemia cell lines at different stages of differentiation
did not produce the same chemokines/cytokines. In order to study the possible functional
importance of the poor chemokine production different T‐cell lines were compared with
respect to development of motile forms and migration on extracellular matrix components in
the absence and presence of various chemokines. RANTES, MIP‐1α, MIP‐1β, IL‐8, GRO‐α
and lymphotactin did not augment the development of motile forms including the size and
appearance of the pseudopodia activity of the T‐leukemia cell lines. The T‐cell lines migrated
spontaneously on/to fibronectin in a Boyden chamber assay system. Chemokines augmented
the migration of the T‐leukemia cell lines on fibronectin in the Boyden system in a chemotactic
fashion with peak responses at 10 to 50 ng/ml. Thus, the production of chemokines is
defective, in neoplastic T‐lymphocytes. The defective chemokine production does not seem to
play any major role for the basic locomotor capacity of the cells but may modulate the
responsiveness to exogenous chemokines.
Balancing Thymocyte Adhesion and Motility:A Functional Linkage Between β1 Lntegrinsand The Motility Receptor RHAMM
Authors: Gares Sheryl L. , Pilarski Linda M.
Published: June 2008

Thymocyte differentiation involves several processes that occur in different anatomic sites
within the thymus. Therefore, thymocytes must have the ability to respond to signals received
from stromal cells and adopt either adhesive or motile behavior. We will discuss our data indicating
human thymocytes use α4β1 integrin, α5β1 integrin and RHAMM to mediate these
activities. Immature multinegative (MN; CD3–4–8–19‐) thymocytes use α4β1 and α5β1
integrins to mediate weak and strong adhesion. This subset also uses α4β1 integrin to mediate
motility. As thymocytes differentiate, they begin to express and use RHAMM to mediate
motility in conjunction with α4β1 and α5β1 integrins. Motile thymocytes use β1 integrins to
maintain weakly adhesive contacts with substrate to provide traction for locomoting cells,
thus weak adhesion is a requirement of motile behavior. Hyaluronan (HA) is also required by
thymocytes to mediate motility. HA binding to cell surface RHAMM redistributes intracellular
RHAMM to the cell surface where it functions to mediate motility. We propose that the
decision to maintain adhesive or motile behavior is based on the balance between low and
high avidity binding conformations of β1 integrins on thymocytes and that RHAMM:HA
interactions decrease high avidity binding conformations of integrins pushing the balance
toward motile behavior.
Fibronectin in Immune Responses in Organ TransplantRecipients
Authors: Coito Ana J. , De Sousa Maria , Kupiec-Weglinski Jerzy W.
Published: June 2008

The immune response to an organ allograft involves perpetuation of T cell infiltration and
activation. Advances in understanding the mechanisms of T cell activation have placed particular
emphasis on the interactions between the T‐cell receptor and antigen presenting cells,
with little reference to the fact that in vivo activation occurs in the physical context of extracellular
matrix proteins (ECM). Indeed, the possibility that ECM proteins may have a determining
role in lymphocyte adhesion and tissue localization and function is now becoming
more appreciated in view of growing evidence indicating that integrins and other T cell antigens
bind ECM components, with some of these components exerting synergistic effects on
T‐ cell activation. This review focuses on the importance of interactions between lymphocytes
and fibronectin, a prominent ECM component, for cell migration and function in
organ allograft recipients. It explores novel therapeutic approaches based on the assumption
that fibronectin represents an active element in the process of T cell activation in the immune
cascade triggered by organ transplantation.
Prolactin and Prolactin Receptor Expression in Rat,Small Intestine, Intraepithelial Lymphocytes DuringNeonatal Developmen
Authors: Urtishak Sandra L. , Mckenna Elizabeth A. , Mastro Andrea M.
Published: June 2008

Intraepithelial lymphocytes (IEL) are specialized T cells found between the epithelial cells of
the small intestine. Because of their location, IEL are the first lymphocytes to contact intestinal
bacteria and food antigens. In the neonate, IEL may be the first cells of the immune system
to interact with milk‐borne hormones including prolactin (PRL). PRL, an endocrine
hormone abundant in breast milk, interacts with cells through surface receptors. PRL has
been shown to function as an immunoregulator and may affect the development of the newborn′s
immune system. To determine if PRL plays a role in IEL development, small intestine
IEL from rats of various ages were examined for the presence of surface prolactin receptor
(PRL‐R) and several lymphoid markers by flow cytometry. Between birth and 96 days of age
about 80% of IEL were found to express PRL‐R. These same cells also expressed the mRNA
for PRL. Additionally, all of the IEL subpopulations examined were found to express PRL‐R.
Analysis of the normal development of rat IEL revealed an age related increase in total IEL,
CD4 positive cells as well as a peak in interleukin‐2 receptor (IL‐2R) expression at weaning.
In summary, the results indicate that IEL express PRL and PRL‐R. In addition, an activation
marker, IL‐2R, changes in expression during neonatal development.
Quantization of the Electric Conductivity in Carbon Nanotubes
Authors: Grado-Caffaro M. A. , Grado-Caffaro M.
Published: June 2008

In this paper, the electric conductivity of carbon nanotubes is investigated by deriving a
mathematical expression for the quantized conductance in an ideal one‐dimensional
potential well with a single electron moving in it. Our results are compared with
experimental data.
Development of lntraepithelial Cellsin the Porcine Small Intestine
Authors: Vega-López M. A. , Arenas-Contreras G. , Bailey M. , González-Pozos S. , Stokes C. R. , Ortega M. G. , Mondragón-Flores R.
Published: June 2008

The number, phenotype, localisation and development of intraepithelial lymphocytes (IEL)
from duodenum (Du) and ileum (Il) were studied by immunohistochemistry (IHC) and light
and electron microscopy in unweaned (0–7 weeks old) and six months‐old pigs. Developmental
changes at birth showed that 38% of the total lymphocytes in the villi were IEL, mainly of
the CD2+CD4‐CD8‐ double negative (DN) phenotype. That proportion rose to over 50% at
week 5 after birth, resembling adult proportion, although still with fewer cells than in adult
pigs. CD4+ cells appeared relatively early in life although they were confined to the lamina
propria (LP) and CD8+ cells were found only in low numbers. In the villi of adult animals,
almost half of the total number of lymphocytes were IEL (49% Du, 52% Il). Over half of
these IEL (52% Du, 53% Il) showed the CD2+CD4‐CD8+ phenotype and were localized at
the epithelium′s basement membrane. Numerous (43% Du, 42% Il) DN IEL were found
grouped at the enterocyte nucleus level and relatively few (5% in Du and Il) granular IEL
were found apically in the epithelium. These proportions were homogeneously maintained
along the villi′s tip, middle and bottom, suggesting that the IEL may have their origin in the
LP. Therefore, the IEL compartment in the porcine intestine develops slowly with age and is
actually composed by a heterogeneous population of cells (null, DN and CD8+). These
results may explain the increased susceptibility of young animals to disease during the lactation
period and should be taken into account when functional studies are carried out with IEL.
The quantitative results of this paper established a model for studies on the effect of age, diet,
normal flora, infection and oral immunization on the IEL of the gut.
A Physical Model for MOSFET Drain Current in Non‐ohmic Regime Using Ohmic Regime Operation
Authors: El Abbassi A. , Amhouche Y. , Raïs K. , Rmaily R.
Published: June 2008

In order to characterise the velocity saturation phenomena in short channel MOSFET′s,
a simple method is proposed in this work. It is based on the comparison between transistor behaviour in ohmic and saturation regime respectively. Therefore, the MOSFET characteristic Id0(Vd). avoiding velocity saturation phenomena, can be obtained from ohmic characteristic Id(Vg)
and compared with the experimental
characteristic Id(Vd).
Differential Effects of Male and Female GonadalHormones on the Intrathymic T cell Maturation
Authors: Pejčić-Karapetrović Branka , Kosec Duško , Leposavić Gordana
Published: June 2008

The study was undertaken to further elucidate a role of gonadal hormones in maintenance of
normal thymocyte maturation and sexual dimorphism in the intrathymic T‐cell development.
Rats of both sexes were gonadectomized or sham‐gonadectomized (controls) at age of 2 and 6
months, and 30 days later the thymus size, cellularity and thymocyte composition were evaluated.
In both control and gonadectomized rats, in spite of age, sexual dimorphism in the thymus
size and cellularity was found. Gonadectomy in 2‐month‐old rats of both sexes increased
the thymus cellularity, volumes of both cortex and medulla and thymus size (to a less extent
in males), while in 6‐month‐old rats, in this respect, it was effective only in females. In ovariectomized
(OVX) rats the increase in volume of cortex was more marked in younger rats,
while that of medulla did not differ between rats of different age. It seems obvious that in both
groups of OVX rats the volume of medullary non‐lymphoid component was enlarged (the
increase in medullary volume was more pronounced than that in its cellularity). Unlikely, in
rats orchidectomized (ORX) at age of 2 months the volume of this component was either
decreased or unaltered (the increase in the volume of medulla was less conspicuous than that
in the number of medullary thymocytes). In control and gonadectomized rats of both ages,
sexual dimorphism in the composition of thymocyte subsets was also observed. Gonadectomy
in 2‐month‐old rats affected distinct stages of thymocyte maturation in male (increased the relative proportions of CD4+8+TCRαβlow cells and their CD4–8+TCRαβlow precursors
and decreased those of the most mature CD4+8‐TCRαβhigh and CD4–8+TCRαβhigh cells)
and female rats (decreased only the percentage of the least mature CD4–8‐TCRαβ‐cells). In
older rats only ovariectomy had impact on the relative proportion of thymocytes decreasing,
besides the relative proportion of CD4–8‐TCRαβ- cells, those of CD4–8+TCRαβ-, CD4–8+TCRαβlow, positively selected CD4+8+TCRαβhigh and the most mature CD4+8‐TCRαβhigh, CD4–8+TCRαβhigh cells and exerting an opposite effect on the percentages of
CD4+8+TCRαβ- and CD4+8+TCRαβlow cells. Thus, results showed sex‐ and age‐dependent
changes in sensitivity of both the developing thymocytes and non‐lymphoid cells to long‐lasting
gonadal deprivation.
Antibodies to Human Thymic Epithelium Form Partof the Murine Autoreactive Repertoire
Authors: Freysdottir Jona , Ritter Mary A.
Published: June 2008

Monoclonal antibody (mAb) MR6 recognises a 200 kDa glycoprotein, gp200‐MR6, which is
expressed at high levels on the surface of human thymic cortical epithelium. In order to produce
further mAbs against the gp200‐MR6 molecule, mice were immunised with purified
human gp200‐MR6, hybridomas produced and supernatants screened for MR6‐like reactivity
on human thymic sections. Surprisingly this conventional hybridoma technique failed to produce
stable hybridoma cells producing MR6‐like antibodies. However, antibodies with specificitie
other than MR6‐like were obtained. Three such antibodies (1B2, 3A3 and 4B3) were
analysed further. Expression of 1B2‐antigen, 3A3‐antigen and 4B3‐antigen was analysed on
skin, tonsil and thymic sections, on cultured thymic epithelial cells (TEC), thymocytes and
peripheral blood mononuclear cells (PBMC), and found to be expressed by both lymphocytes
and epithelial cell populations. Furthermore, the antigens were also expressed on mouse
thymic, epithelial cells. The regulation of expression of these antigens was analysed following
mitogen or cytokine stimulation of PBMC and cultured TEC, respectively. Expression on T
cells was clearly affected by mitogens that mimic activation through the T cell receptor and
expression on cultured TEC was affected by T cell‐derived cytokines. Thus, the shared epithelial‐
lymphocyte molecules identified in this study may play a role in the cross‐talk
between the developing thymocytes and their epithelial microenvironment. The production of
mAbs with specificities other than that of purified gp200‐MR6 indicates that a wide range of
B cells with specificity for components of the human thymic microenvironment exist in the
normal mouse. These may detect epitopes that are shared with common pathogens to which
the animals are exposed. Alternatively, they may be autoreactive B cells that are normally
silent in the absence of T cell help. This help may be provided by T cells specific for human
gp200‐MR6, or nonspecifically by polyclonal activation induced by the adjuvant.
Peyer′s Patches Are Precocious to the Appendix in Human Development
Authors: Bhide S. A. , Wadekar K. V. , Koushik S. A.
Published: June 2008

PP are first visible at ∼15.5 wk gestation after which there is a rapid spurt in the development
and maturation of lymphoid follicles so that at any given point of time new foci of PP development
are continuously formed at a rapid rate. Addition of rows of follicles results in the
formation of a PP. Immature PP of younger fetuses have a spongy structure in contrast with
the compact lymphoid follicles of mature PP of older fetuses. Immunocytochemical studies
reveal that there is a subtle gradation in the expression of lymphocyte surface markers with
increasing fetal age. Expression of antigenic markers occurs in an ordered sequence viz. HLA – DR, CD19 (B cell population), CD9 (pre‐B cells), CD3 T lymphocytes, CD4 helper / inducer lymphocytes, the CD8 suppressor / cytotoxic cells and lastly, the CD57 Natural Killer cells. The antigens are expressed first on lymphocytes of PP and thereafter in those of the appendix. Our findings clearly demonstrate that the ∼5 wk fetal period from 17.5 wk to 22 wk
represents a major growth phase in the development of surface markers of lymphocytes in the
mucosal immune system of the gut.
Incidence of Apoptosis in the Lymphoid Organs of Normalor Malaria Infected Mice is Decreased in CD18 andUrokinase ‐ Receptor (UPAR, CD87) Deficient Mice
Authors: Piguet Pierre Francois , da Laperrousaz Chen , Vesin Christian , Donati Yves
Published: June 2008

Incidence of apoptosis was investigated in the spleen and lymph nodes of +/+, CD18 ‐/‐ and
urokinase receptor (uPAR, CD87) ‐/‐ mice, untreated or Plasmodium Berghei Anka (PbA)
infected. In non infected mice, incidence of apoptosis was lower in the lymph nodes of CD18
‐/‐ and uPAR ‐/‐ than in +/+ mice, as seen by FACS analysis to count the number of hypodiploid
and Annexin‐V binding cells. Infection of mice with PbA resulted in a marked increase
in the size of spleen and lymph nodes 7–8 days after infection, which was slightly higher in
uPAR ‐/‐ and CD18 ‐/‐ than in +/+ mice. PbA infection increased about 7 fold the incidence of
apoptosis in the lymphoid organs of +/+, especially in the white pulp and germinal centers of
the spleen and lymph nodes, while in contrast it was unchanged in PbA infected CD18 ‐/‐ or
uPAR ‐/‐ mice. Serum IgG levels, and number of circulating leukocytes were significantly
higher in both uPAR and CD18 ‐/‐ than in +/+ mice. These results indicate that the CD18 and
uPAR surface molecules, which are known to be associated in the cell membrane, have an
important influence upon the incidence of cell survival in both normal or stimulated lymphoid
organs.
New Coefficients of the Minority Carrier Lifetime and Bandgap Narrowing Models in the Transparent Emitter of Thin Film Silicon Solar Cells
Authors: Benosman M. , Zerga A. , Dujardin F. , Benyoucef B. , Charles J-P.
Published: June 2008

In this study we have determined new coefficients for the physical model describing the
band‐gap narrowing and the minority carriers lifetime. This was accomplished according
to the doping level of the thin emitter. This model allows us to take into account both the
effects of the heavy doping and the majority carrier degeneration for the very high level
of doping. The results we obtain by the corrected model are in good agreement with
those reported in the literature and in different experiments. They show us the
possibility of accurately evaluating the performances for the n+p silicon solar cell.
This model is then used to introduce a new concept for the thin layer emitter, called
transparent emitter.
Slow Adaptive M‐QAM under Third‐Party Received Signal Constraints in Shadowing Environments
Authors: Li Yan , Kishore Shalinee
Published: June 2008

Motivated by recent interest in dynamic spectrum sharing between primary and secondary spectrum
users, we investigate slow adaptive quadrature amplitude modulation (QAM) under third‐party received power constraints. The optimal rate and power adaptation schemes are derived to maximize the average spectral efficiency (SE) for the secondary users. Additionally, closed‐form expressions of the achievable SE are presented for correlated lognormal shadow fading environments. Our analytical and numerical results underscore the importance of exploiting shadowing correlation in the proposed adaptive schemes.
Modulus of Convexity, the Coeffcient R(1, X), and Normal Structure in Banach Spaces
Authors: Jiao Hongwei , Guo Yunrui , Wang Fenghui
Published: June 2008

Let δX(ϵ) and R(1, X) be the modulus of convexity and the Domínguez‐Benavides coefficient, respectively. According to these two geometric parameters, we obtain a sufficient condition for normal structure, that is, a Banach space
X has normal structure if
2δX(1 + ϵ) > max{(R(1, x) − 1)ϵ, 1 − (1 − ϵ/R(1, X) − 1)} for some ϵ ∈ [0, 1] which generalizes the known result by
Gao and Prus.
Pattern Expression Nonnegative Matrix Factorization: Algorithm and Applications to Blind Source Separation
Authors: Zhang Junying , Wei Le , Feng Xuerong , Ma Zhen , Wang Yue
Published: June 2008

Independent component analysis (ICA) is a widely applicable and effective approach in blind source separation (BSS), with limitations that sources are statistically independent. However, more common situation is blind source separation for nonnegative linear model (NNLM) where the observations are nonnegative linear combinations of nonnegative sources, and the sources may be statistically dependent. We propose a pattern expression nonnegative matrix factorization (PE-NMF) approach from the view point of using basis vectors most effectively to express patterns. Two regularization or penalty terms are introduced to be added to the original loss function of a standard nonnegative matrix factorization (NMF) for effective expression of patterns with basis vectors in the PE-NMF. Learning algorithm is presented, and the convergence of the algorithm is proved theoretically. Three illustrative examples on blind source separation including heterogeneity correction for gene microarray data indicate that the sources can be successfully recovered with the proposed PE-NMF when the two parameters can be suitably chosen from prior knowledge of the problem.
Three‐Dimensional Silicon‐Germanium Nanostructures for CMOS Compatible Light Emitters and Optical Interconnects
Authors: Tsybeskov L. , Lee E.-K. , Chang H.-Y. , Kamenev B. V. , Lockwood D. J. , Baribeau J.-M. , Kamins T. I.
Published: June 2008

Three‐dimensional SiGe nanostructures grown on Si (SiGe/Si) using molecular beam epitaxy or low‐pressure chemical vapor deposition exhibit photoluminescence and electroluminescence in the important spectral range of 1.3–1.6 μm. At a high level of photoexcitation or carrier injection, thermal quenching of the luminescence intensity is suppressed and the previously confirmed type‐II energy band alignment at Si/SiGe cluster heterointerfaces no longer controls radiative carrier recombination. Instead, a recently proposed dynamic type‐I energy band alignment is found to be responsible for the strong decrease in carrier radiative lifetime and further increase in the luminescence quantum efficiency.
PPARγ and PPARδ as Modulators of Neoplasia and Cell Fate
Authors: Glazer Robert I. , Yuan Hongyan , Xie Zhihui , Yin Yuzhi
Published: June 2008

PPARγ and PPARδ agonists represent unique classes of drugs that act through their ability to modulate gene transcription associated with intermediary metabolism, differentiation, tumor suppression, and in some instances proliferation and cell adhesion. PPARγ agonists are used by millions of people each year to treat type 2 diabetes but may also find additional utility as relatively nontoxic potentiators of chemotherapy. PPARδ agonists produce complex actions as shown by their tumor promoting effects in rodents and their cholesterol‐lowering action in dyslipidemias. There is now emerging evidence that PPARs regulate tumor suppressor genes and developmental pathways associated with transformation and cell fate determination. This review discusses the role of PPARγ and PPARδ agonists as modulators of these processes.
Statistical Methods for Mapping Multiple QTL
Authors: Zou Wei , Zeng Zhao-Bang
Published: June 2008

Since Lander and Botstein proposed the interval mapping method for QTL mapping data analysis in 1989, tremendous progress has been made in the last many years to advance new and powerful statistical methods for QTL analysis. Recent research progress has been focused on statistical methods and issues for mapping multiple QTL together. In this article, we review this progress. We focus the discussion on the statistical methods for mapping multiple QTL by maximum likelihood and Bayesian methods and also on determining appropriate thresholds for the analysis.
Multivariate p‐Adic Fermionic q‐Integral on ℤp and Related Multiple Zeta‐Type Functions
Authors: Kim Min-Soo , Kim Taekyun , Son Jin-Woo
Published: June 2008

In 2008, Jang et al. constructed generating functions
of the multiple twisted Carlitz′s type q‐Bernoulli polynomials and obtained
the distribution relation for them. They also raised the following problem:
“are there analytic multiple twisted Carlitz′s type q‐zeta functions which
interpolate multiple twisted Carlitz′s type q‐Euler (Bernoulli) polynomials?”
The aim of this paper is to give a partial answer to this problem. Furthermore
we derive some interesting identities related to twisted q‐extension of Euler
polynomials and multiple twisted Carlitz′s type q‐Euler polynomials.
Development of Silicon Photonics Devices Using Microelectronic Tools for the Integration on Top of a CMOS Wafer
Authors: Fedeli J. M. , Di Cioccio L. , Marris-Morini D. , Vivien L. , Orobtchouk R. , Rojo-Romeo P. , Seassal C. , Mandorlo F.
Published: June 2008

Photonics on CMOS is the integration of microelectronics technology and optics components to enable either improved functionality of the electronic circuit or miniaturization of optical functions. The integration of a photonic layer on an electronic circuit has been studied with three routes. For combined fabrication at the front end level, several building blocks using a silicon on insulator rib technology have been developed: slightly etched rib waveguide with low (0.1 dB/cm) propagation loss, a high speed and high responsivity Ge integrated photodetector and a 10 GHz Si modulators. Next, a wafer bonding of silicon rib and stripe technologies was achieved above the metallization layers of a CMOS wafer. Last, direct fabrication of a photonic layer at the back‐end level was achieved using low‐temperature processes with amorphous silicon waveguide (loss 5 dB/cm), followed by the molecular bonding of InP dice and by the processing in microelectronics environment of InP μsources and detector.
Homogenization of Mutually Immiscible Polymers Using Nanoscale Effects: A Theoretical Study
Authors: Montes Sarah , Etxeberria Agustín , Rodriguez Javier , Pomposo Jose A.
Published: June 2008

A theoretical study to investigate homogenization of mutually immiscible polymers using nanoscale effects has been performed. Specifically, the miscibility behavior of all-polymer nanocomposites composed of linear-polystyrene (PS) chains and individual cross-linked poly(methyl methacrylate)-nanoparticles (PMMA-NPs) has been predicted. By using a mean field theory accounting for combinatorial interaction energy and nanoparticle-driven effects, phase diagrams were constructed as a function of PMMA-NP size, PS molecular weight, and temperature. Interestingly, complete miscibility (i.e., homogeneity) was predicted from room temperature to 675 K for PMMA-nanoparticles with radius less than ~7 nm blended with PS chains (molecular weight 150 kDa, nanoparticle volume fraction 20%) in spite of the well-known immiscibility between PS and PMMA. Several nanoscale effects affecting miscibility in PMMA-NP/PS nanocomposites involving small PMMA-nanoparticles are discussed.