bluuebunny/crossref_metadata_2025 huggingface dataset:
Herstellung pulverförmiger mehrphasiger Komposite mittels des PGSS‐Verfahrens
Authors: Wendt T. , Brandin G. , Kilzer A. , Petermann M. , Weidner E.
Published: February 2007

In den vergangenen Jahren lag der Schwerpunkt der Partikelerzeugung mit Hilfe des PGSS (Particles from Gas Saturated Solutions) ‐Verfahrens auf der Herstellung von Pulvern aus Einkomponentensystemen und Kompositen aus festen Ausgangsmaterialien für die Pulverlackindustrie. Zur Erzeugung von Pulverlacken wurden hierbei zumeist komplett mischbare Systeme aus einem Härter und einem Binder versprüht. In Ergänzung zu den vorangegangenen Arbeiten wurden jetzt erstmalig mehrphasige pulverförmige Komposite hergestellt, bei denen eine Flüssigkeit in Pulverpartikeln eingekapselt wurde. Es wurden unterschiedliche Systeme untersucht, um die Eigenschaften und Abhängigkeiten der erzeugten Systeme von den Prozessparametern, den benutzten Substanzen und der Emulsionsstabilität zu zeigen. Dies wird unter anderem für ein Paraffinwachs gezeigt, das in einem Polyester verkapselt wurde. Um den Einfluss der Emulsionsstabilität näher zu untersuchen, wurden drei weitere Stoffpaarungen mit erhöhter Emulsionsstabilität pulverisiert.
Reduktion der Prozessschritte durch unmittelbare Selbstbeschichtung von Partikeln
Authors: Römbach E. , Ulrich J.
Published: February 2007

An dem binären Stoffsystem Ibuprofen und Cetylpalmitat soll die Anwendbarkeit der Idee der unmittelbaren Selbstbeschichtung überprüft werden. Da die unmittelbare Selbstbeschichtung sehr stark von den thermophysikalischen Eigenschaften des Stoffsystems abhängt, werden das Phasendiagramm, der Trenneffekt während der Kristallisation sowie die thermische Stabilität des Stoffsystems untersucht. Zur Bestimmung des Phasendiagramms wird die Differential Scanning Calorimetry angewandt. Die thermische Stabilität der Reinstoffe wird mithilfe der Thermogravimetrie und der Pulverröntgendiffraktometrie überprüft.
Einsatz unterschiedlicher Rührwerkskugelmühlen für die Erzeugung von Nanopartikeln
Authors: Breitung‐Faes S. , Kwade A.
Published: February 2007

Die Erzeugung von keramischen Nanopartikeln, insbesondere von Metalloxiden, durch Zerkleinerung in Rührwerkskugelmühlen ist zurzeit noch durch einen hohen Verschleiß der Mahlkörper und die damit verbundene Produktkontamination sowie hohe Energieeinträge und lange Zerkleinerungszeiten gekennzeichnet. Durch den Einsatz sogenannter Hochleistungsmühlen und die gezielte Modifizierung des Prozesses sollen die Wirtschaftlichkeit und die Produktqualität verbessert werden. Zur Ermittlung der Leistungsfähigkeit unterschiedlicher Mühlengeometrien wurden zunächst zwei Hochleistungsmühlen im Vergleich zur klassischen Rührwerkskugelmühle mit Lochscheibenrührwerk untersucht. Beide Hochleistungsmühlen weisen höhere Leistungsdichten auf als die Lochscheiben‐Rührwerkskugelmühle. Dies bedeutet vor allem im submikronen Bereich eine schnellere und effektivere Zerkleinerung. Der auf das Produkt bezogene Verschleiß der Mahlkörper konnte dabei nicht verringert werden.
Effect of normal mouse serum on mouse lymphocyte transformation in vitro
Authors: Nelson D. S. , Shneider Cynthia N.
Published: February 2007

Mouse spleen cells were cultured in the presence or absence of one of the following mitogens: phytohemagglutinin (PHA), concanavalin A, allogeneic spleen cells or bacterial lipopolysaccharide. The addition of normal mouse serum (NMS) to the cultures usually depressed mitogen‐induced lymphocyte transformation as measured by DNA, RNA or protein synthesis, whether calculated as gross or net synthesis. The degree of depression was increased as the concentration of NMS serum increased. DNA and RNA synthesis in unstimulated cultures were also usually depressed by NMS. NMS added 24 hours or more after the start of cultures with PHA or allogeneic lymphocytes was less depressive than serum present from the start and in some cases, actually increased DNA synthesis. The presence of NMS in cultures containing supra‐optimal doses of concanavalin A could also increase DNA synthesis. Cells incubated with NMS for 24 hours survived as well as cells incubated without NMS, but subsequently responded less well to PHA. Cells passed through a column of glass wool had a lower baseline DNA synthesis, which was not inhibited by NMS; they responded less well to mitogens and this response was further depressed by NMS.

It is suggested that NMS contains a factor which damps the proliferation of mouse T and B cells, without exerting an overt cytotoxic effect, and that it acts directly on lymphocytes.
Antigenic determinants in the N‐terminal halves of human κ‐chains; their relation to the variable region subgroups
Authors: Orlans Eva , Pearce Cheryl A.
Published: February 2007

Antibodies directed against the variable (V) regions of both the heavy and light chains are found consistently in fowl antisera to polyclonal human F(ab′)2. When tested by absorption and precipitation with κ‐Bence‐Jones proteins of known amino acid sequences, nearly all such antisera were found to contain antibodies specific for one or more of the three basic Vκ sequences. This result indicates that a very high proportion of the normal κ‐chain population carries determinants which correspond to sequence patterns derived from analyses of pathological monoclonal proteins.

Although it was possible to determine the Vκ subgroups of some intact monoclonal immunoglobulins with antisera, the procedure has serious limitations. One of these is the need to absorb all antibody to VH‐region antigens with suitable monoclonal λ proteins; of 14 IgM proteins examined with such absorbed antisera, 8 were found to have κI light chains, 3 were κIII, I was κII, and 2 could not be classified. Another limitation, which applies also to Bence‐Jones proteins, is the occurrence of antigenically deficient κ‐chains, accounting for 10–20% of the proteins tested. One such protein (κIII Rad) did not precipitate with most of the anti‐VκIII sera, but differed in only 7 positions from the basic κIII sequence.
Increase in intracellular immunoglobulins in the majority of splenic lymphoid cells after primary immunization
Authors: Pachmann Katharina , Killander D. , Wigzell H.
Published: February 2007

The amount of immunoglobulin (Ig) in individual mouse spleen lymphocytes was determined by quantitative microspectrofluorimetry after “staining” with fluorescein‐labeled anti‐Ig antibodies. During a primary immune response against sheep erythrocytes, maximally 0.015 % of the cells produced direct hemolytic plaques, but close to 100 % of lymphoid cells displayed an increase in their intracellular Ig on day 3 to 4 after immunization. This increase consisted of IgM, later to be followed in a large fraction (up to 80 %) of the cells by IgGl. A positive correlation was found between rate of protein synthesis and fluorescence intensity in the single cell. Preliminary data suggested that activated thymus‐derived cells displayed an increase in an intracellular material, cross‐reactive with serum IgM. Attempts to demonstrate that the intracellular increase was due to endocytosis of Ig in various forms failed in several model systems. The reported phenomenon might demonstrate the production of a substance, capable of alerting the majority of all lymphoid cells during a primary immune response, into increased Ig synthesis.
Cell surface immunoglobulin. VI. Dynamics on a human lymphoma line
Authors: Grundke‐Iqbal Inge , Uhr J. W.
Published: February 2007

Release of cell surface Ig and secretion of Ig has been studied in Daudi cells, a human lymphoma cell line synthesizing IgM that appears to be a neoplastic counterpart of B lymphocytes. In contrast to murine splenocytes, virtually no internally labeled Ig and only a small proportion of cell surface Ig are released during 8 hours of in vitro incubation. Released cell surface Ig can be recovered in the medium predominantly as 8 S IgM monomer probably attached noncovalently to a fragment of plasma membrane. This shedding of cell surface Ig appears to be dependent on the prior culture phase of the cells. Thus, in cells from cultures kept at high density, there was greater release of cell surface Ig apparently associated with cell death.
Binding and redistribution of lectins on lymphocyte membrane
Authors: Loor F.
Published: February 2007

The redistribution of fluorochrome‐conjugated agglutinins bound to the lymphocyte plasma membrane is investigated. Two “T” lymphocyte mitogens (concanavalin A (Con A) and phytohemagglutinin (PHA)) bind to and redistribute equally well (spotting and capping) on the lymphocyte, whether they are “B” (Ig+) or “T” (Ig−).

One B cell mitogen (pokeweed mitogen (PWM)) does not bind detectably either to T or to B lymphocytes, although it binds to macrophages and to thymocytes in a perfectly ring‐like pattern. Its redistribution requires anti‐PWM antibodies.

The nonmitogenic poly‐L‐lysine (PLL) binds to virtually all lymphocytes, and rapidly forms caps. PLL binds more strongly to T cells than to B cells.

The agglutinin concentration is critical for the formation of agglutinin caps on the cell surface, as well as for the free mobility of Ig receptors.

Finally, lectin‐coated beads pick up B and T cells equally well, irrelevantly of their mitogenicity. Cell attachment to agglutinin‐coated beads does not induce any demonstrable capping of either agglutinin‐binding sites or membrane Ig. When the cells are further treated with soluble agglutinins or anti‐Ig antibodies, they form caps mainly oriented towards the lectin‐coated beads.

These results show the high mobility of lymphocyte membrane components, the independence of agglutinin‐binding sites and of most of the Ig receptors, and a polarization of cell with regard to cap formation. They exclude any straightforward correlations between agglutinin binding, membrane component redistribution and lymphocyte triggering.
Bursal and postbursal cells in chicken Separation by gradient centrifugation
Authors: Toivanen P. , Toivanen A. , Tamminen P.
Published: February 2007

Lymphoid cells of bursa of Fabricius taken from 2 1/2‐week old chickens were separated in a discontinuous albumin gradient into six fractions. At this age, the bursa contains bursal stem cells and early postbursal cells; only the bursal stem cells are capable of restoring the bursal morphology of cyclophosphamide‐treated recipients. Cells from each fraction of the albumin gradient were injected into 4‐day old cyclophosphamide‐treated, histocompatible recipients. Forty days after the cell transplantation, microscopic morphology of bursa and spleen, and antibody formation to sheep red blood cells and Brucella abortus were studied. The low density bursa cells were found capable of a significant restoration of the bursal morphology, while those with a higher density had significantly less effect on the bursal morphology. When bursa cells from 10‐week old donors were used, no clear fractionation was obtained according to the capacity to restore the bursal morphology of cyclophosphamide‐treated recipients. These findings indicate that the bursal stem cells capable of restoring bursal structure of cyclophosphamide‐treated chicks are, in average, lighter in density than the postbursal cells.
Effects of anti‐immunoglobulin sera on migration inhibition mediated by human lymphocytes
Authors: Marsman A. J. W. , van der Hart Mia
Published: February 2007

Migration inhibition experiments were performed with mixtures of sensitized human lymphocytes and guinea pig peritoneal exudate cells. Treatment of human lymphocytes with a rabbit anti‐human light chain serum (ALCS) abolished their capacity to cause antigen‐induced migration inhibition, whereas treatment with anti‐heavy chain sera did not. The specificity of ALCS was confirmed by absorption studies. The finding that anti‐heavy chain sera did not influence migration inhibition is consistent with other evidence that B cells are not directly involved in the migration inhibition process. The results provide indirect evidence that the — presumably thymus‐dependent — lymphocytes primarily involved in the migration inhibition process carry light chain determinants on their membrane.
T cell recognition of cell‐surface antigens. II. Antigen recognition is necessary yet not sufficient for triggering T cell‐mediated immunity
Authors: Wekerle H. , Kölsch E. , Feldman M.
Published: February 2007

We investigated whether recognition per se of cell surface antigens by lymphocytes is both necessary and sufficient to trigger sensitization of T cells. We assayed sensitization of normal rat lymphocytes against monolayers of mouse fibroblasts by measuring the acquisition of cytotoxicity against target monolayers syngeneic to the sensitizing monolayer, following 5 days of culturing on living or glutaraldehyde‐fixed fibroblasts. Monolayers of either living or glutaraldehyde‐treated fibroblasts were used as cellular immunoadsorbents to assay recognition.

Glutaraldehyde treatment of mouse fibroblasts did not seem to alter the cell surface antigens detectable by alloantibodies. Yet, rat lymphocytes cultured on such monolayers did not undergo sensitization. This was not due to the lack of feeder effect by the glutaraldehyde‐fixed monolayers, since the addition of living rat fibroblasts, which sustained the survival of the lymphocytes, did not result in sensitization. Not even when living fibroblasts were added to syngeneic fixed monolayers did sensitization of the rat lymphocytes against the monolayer cells occur. Yet, addition of living fibroblasts to fixed allogeneic monolayers resulted in sensitization against the living fibroblasts, but not against the fixed cells.

To test whether lymphocytes recognize surface antigens of glutaraldehyde‐treated monolayers, the capacity of the latter to specifically adsorb lymphocytes possessing receptors for the fibroblast antigen was measured. The nonadhering rat lymphocytes, seeded on glutaraldehyde‐treated C3H fibroblasts, lost their capacity to become sensitized against fresh C3H cells, but retained their capacity to react against BALB/c fibroblasts. Recognition of C3H antigen did take place, yet this was not sufficient to trigger sensitization. Thus, rat lymphocytes seem to recognize the antigens of fixed monolayers, but cannot respond to them.
Evaluation of two sources of soluble HL‐A antigens: platelets and serum
Authors: Pellegrino M. A. , Ferrone S. , Pellegrino Anna G. , Oh S. K. , Reisfeld R. A.
Published: February 2007

Platelets and human serum have been evaluated as sources for extraction of soluble HL‐A antigens. 3 M KCl was found to efficiently solubilize HL‐A antigens from platelets with a recovery ranging between 50 and 100 %. However, because of the low density of HL‐A determinants on platelets, the yield of soluble antigens is low, as only 1 mg of protein can be recovered from 1 × 109 platelets. Thus, while it is difficult to solubilize sufficient antigens from platelets for chemical characterization, it is possible to use these materials for biological applications such as pretreatment of kidney recipients. Soluble HL‐A antigen is present in human serum, since following extensive ultracentrifugation, it can still effectively inhibit the cytotoxic activity of HL‐A alloantisera. The same HL‐A specificities were found to be present in varying amounts among different donors. Partial purification of such antigens can be achieved by ion‐exchange chromatography of serum on QAE‐Sephadex.
Inability to block the activity of guinea pig migration inhibitory factor with di‐isopropyl phosphorofluoridate
Authors: David J. R. , Becker E. L.
Published: February 2007

Studies were carried out to confirm a previous report that the activity of migration inhibitory factor (MIF) was blocked by di‐isopropyl phosphorofluoridate (DFP), suggesting it acted as a protease. MIF was obtained by the stimulation of guinea pig lymphocytes with concanavalin A and the culture supernatants were chromatographed on Sephadex G‐100 gel columns. The MIF‐rich fraction was incubated with DFP or with other organophosphorus esterase inhibitors; the inhibitors were removed by dialysis, and the media were tested for MIF activity. The results, reported here, indicate that guinea pig MIF activity is not destroyed by treatment with serine esterase inhibitors.
Cell surface markers for human T and B lymphocytes
Authors: Brown G. , Greaves M. F.
Published: February 2007

A series of 4 cell surface marker systems have been developed and applied to human thymus, tonsil and purified blood lymphocyte populations. Double fluorochrome and mixed fluorochrome‐rosette tests were used to determine cellular specificity and interrelationship of cells bearing the different markers and the results confirmed by a variety of cell separation procedures. Anti‐brain antisera were, after appropriate absorption, T cell‐specific and identified the same population as that forming rosettes with sheep erythrocytes. This T cell population was quite distinct from those cells, presumably B lymphcytes, with cell surface immunoglobulin readily demonstrable by fluorescence. A small proportion of “lymphoid” cells (“null” cells) lacked all three markers. Heat‐aggregated human IgG (AggHIgG) was also used as a presumptive B cell marker and the results indicate that although most B lymphocytes do bind AggHIgG, presumably via an Fc receptor, a small proportion of thymocytes and presumptive T cells in tonsils also appear to possess a similar receptor. Almost all of these cells in tonsil were in fact lymphoblasts, thus raising the possibility that an Fc receptor is exposed or expressed on T lymphocytes when these cells are activated.
Characterization of an immune response gene in mice controlling IgE and IgG antibody responses to ragweed pollen extract and its 2,4‐dinitrophenylated derivative
Authors: Dorf M. E. , Newburger P. E. , Hamaoka T. , Katz D. H. , Benacerraf B.
Published: February 2007

The strain distribution of IgE and IgG antibody responses to ragweed extract (RE) and its dinitrophenylated derivative (DNPRE) characterize a new immune response gene, Ir‐RE. Responder strains show higher primary and secondary levels of both antibody classes than nonresponders after immunization with these antigens in aluminium hydroxide gel, the differences being most marked at low doses, but present over a wide dose range (10 to 500 μg/mouse). High responses are associated with H‐2a, d, h, k, m, n and p types; low responses with H‐2b, f, i, j and u. The Ir‐RE gene has been mapped to the H‐2 region by the use of congenic resistant strains, and to the H2K‐Ir‐1 region with H‐2 recombinants. The high response allele is dominant and appears, by its regulation of anti‐hapten responses in the DNP‐RE hapten‐carrier system, to act at the cellular level of thymus‐derived lymphocytes. T cells possessing this gene control responses of IgG and IgE·B lymphocytes in a parallel fashion.
Selective binding of chemically defined antigenic peptides to mouse lymphocytes
Authors: Kelly Barbara , Kaye B. , Yoshizawa W. , Levy Julia Gerwing , Kilburn D. G.
Published: February 2007

Immunologically active peptides containing either two different (N10C) or two identical (N8N) antigenic amino acid sequences, bridged by 10 and 8 glycine residues, respectively, were used to study antigen‐binding lymphocyte populations in BALB/c mice. Spleen cells from mice immunized with either N10C or N8N were treated with either normal rabbit serum or brain associated anti‐thymus (BA Θ) serum and subsequently examined by autoradiography for the numbers of cells binding 125I‐labeled N10C, and 125I‐labeled conjugates of either the C antigenic determinant or the N antigenic determinant with polyDglutamic acid. In unimmunized mice there were more cells binding the N determinant than the C determinant. After anti‐BA Θ treatment, the relative numbers of each population increased, implying that many of these cells were bone marrow‐derived. In N10C or N8N immunized mice, the numbers of cells binding the N determinant remained virtually unchanged after anti‐BA Θ treatment, indicating an equal distribution of these cells in both bone marrow or thymus‐derived populations. However, the C determinant binding population in N10C immunized animals appeared to be mainly of bone marrow origin. Since the C determinant exhibited mainly B cell reactivity, the role of thymus cells in immune responsiveness to a peptide (Cmal10C) containing two C determinants was examined. Only those mice which were reconstituted with both bone marrow and thymus cells after thymectomy and irradiation were capable of responding normally to this antigen, demonstrating thymus involvement even with antigens that appear to be mainly reactive with B cells.
Larval thymectomy and transplantation immunity in the urodele Pleurodeles waltlii Michah. (Salamandridae)
Authors: Charlemagne J.
Published: February 2007

The effect of thymectomy at the mid‐larval stage of development on the skin allograft response in the urodele, Pleurodeles waltlii Michah, was examined. Two experimental series are described: in the first, noninbred animals were used and in the second, two inbred strains, A and B, were studied. In both series, larval thymectomy clearly resulted in abrogation of the skin allograft rejection response. Some thymectomized animals developed a wasting disease.
T cell dependence of B cell unresponsiveness in vitro
Authors: Waldmann H. , Munro A. J.
Published: February 2007

Antigen‐specific high zone unresponsiveness to two thymus‐dependent antigens, TNP560KLH (2,4,6trinitrophenylkeyhole) limpet hemocyanin and TNP6FGG (2,4,6trinitrophenylfowl IgG), was induced in vitro. It was found that carrier recognition was required for its production, and that unresponsiveness was present at the level of B cells.

Thymus‐derived cells were required to induce the unresponsive state in B cells.
Diversity of antibodies to cross‐reacting nitrophenyl haptens in inbred mice
Authors: Pink J. R. L. , Askonas Brigitte A.
Published: February 2007

The use of cross‐reacting antigens to stimulate antibody responses of limited heterogeneity is described. The cross‐reacting haptens 2,4dinitrophenyl (DNP) and 2,4,6trinitrophenyl (TNP), coupled to ovalbumin or bovine IgG, were employed as immunogens in inbred CBA/J and C3H/He mice. Sera from mice primed with DNP‐protein and subsequently boosted with TNP coupled to the same carrier were examined by isoelectric focusing techniques. The anti‐DNP antibodies in these sera were shown to consist of the products of a small number (usually less than 4) of clones.

The frequency of occurrence of anti‐DNP antibodies that were indistinguishable by isoelectric focusing techniques was estimated. In 2400 comparisons between antibodies in sera from 140 individual mice, a small number (5 to 7) of indistinguishable antibody pairs was found. It was estimated from these results that not less than about 500 different sorts of antibodies to DNP, strongly cross‐reacting with TNP, can be made by inbred mice immunized with these cross‐reacting antigens. The problem of natural selection for the ability to produce such a large variety of antibodies is discussed.
Histocompatibility antigens and genetic control of the immune response in guinea pigs. I. Specific inhibition of antigen‐induced lymphocyte stimulation by alloantisera
Authors: Geczy A. F. , de Weck A. L.
Published: February 2007

Alloantisera raised by cross‐immunizing with lymphoid cells in outbred and inbred strains of guinea pigs have permitted the serological identification of several alleles of a GPL‐A locus, which differs from the 2/13 locus distinguishing NIH strain 2 and 13 guinea pigs. Five guinea pig strains, homozygous for GPL‐A and 2/13 antigens, were sequentially immunized with seven structurally unrelated antigens ((T,G)‐A–L, penicilloylated bovine IgG and poly‐L‐lysine, aspirin anhydride, phenetidine, horseradish peroxidase and DNP‐dodecapeptide). Considerable differences in the immune response were observed, as measured by skin tests and antigen‐induced lymphocyte stimulation in vitro.

Addition of small amounts of alloantisera to the culture medium in several cases caused a marked inhibition of antigen‐induced stimulation. As demonstrated in some parental strains and especially in F1 hybrid animals, the inhibiting effect is not due to killing or blindfolding of the responding lymphocytes, but suggests a direct and specific interference of the corresponding alloantisera with the recognition of antigen by specific T cell receptors. It is not yet established whether our alloantisera contain antibodies not only to histocompatibility antigens, but also antibodies specific for antigen receptors. Alternatively, the results may reflect identity or close spatial arrangement between histocompatibility antigens and specific antigen receptors. In any case, the experimental models presented offer new possibilities in the investigation of the genetic control of the immune response and its linkage to histocompatibility antigens.
Are there Y‐linked histocompatibility antigens in man?
Authors: Oliver R. T. D.
Published: February 2007

Analysis of three hundred and forty‐nine cadaver renal grafts has shown significantly better survival of female recipients of a male graft when compared to the survival of female recipients of a female graft. Survival of male grafts was intermediate between the two extremes of female recipient survival and no influence of donor sex was apparent.
Differentiation of T cell precursors in nude mice. Rejection of heart grafts of thymus donor strain
Authors: Seger R. , Rogers K. , Catty D.
Published: February 2007

Thymus grafted nude mice showed no tolerance to neonatal heart grafts of thymus donor origin. This finding is in contradiction with the Jerne hypothesis on the somatic generation of immune recognition and in agreement with Bretscher's hypothesis on generalized autoimmunity.
The role of cellular interaction in differentiating between the occurrence of immunological tolerance and immunity following antigenic challenge
Authors: McCullagh P.
Published: February 2007

The response to antigenic challenge was examined in irradiated recipients of mixtures of lymphocytes from normal and sheep erythrocyte‐tolerant donors. If tolerant lymphocytes were cocultivated with normal cells in numbers similar to or greater than them, the responsiveness of the latter to subsequent challenge with sheep erythrocytes could be drastically impaired. However, the supplementation of an inoculum of normal lymphocytes with smaller numbers of tolerant cells resulted in a marked augmentation of the immune response. It is suggested that the expression of either tolerance or immunity after exposure of an animal to antigen is dependent on the size of the subpopulation of its lymphocytes that has been activated by that antigen.
Evidence for an association between immune responsiveness of chicken to (T, G)‐A–L and the major histocompatibility system
Authors: Günther E. , Balcarová J. , Hála K. , Rüde E. , Hraba T.
Published: February 2007

The antibody response of different inbred chicken lines to the synthetic polypeptide (T, G)‐A–L is described. It is shown by analysis of backcross hybrids that a major gene controlling this response is linked to the major histocompatibility system of chicken. This result is discussed with respect to its relation to the structure of major histocompatibility systems of mammals.
Studies of hyperimmune restricted and partially restricted anti‐pneumococcal polysaccharide antibodies from allotype‐defined pedigreed rabbits. I. Preparative liquid isoelectric focusing of the antibodies and characterization of the isolated fractions by electrophoretic techniques
Authors: Freedman M. H. , Pincus J. H. , Yeger H. , McKenney Judith A. , Mage Rose G.
Published: February 2007

Four heterozygous rabbits (a2 a2, b4 b5; a1 a2, b6 b9; a2 a2, b5 b9; a3 a3, b4 b5) and one homozygous rabbit (a2 a2, b6 b6) were hyperimmunized with either type 3 or 8 pneumococcal vaccines. Four antisera were partially restricted and one antiserum was highly restricted. The immunoglobulins (Ig) were obtained by salt precipitation, ion‐exchange chromatography, and affinity chromatography. The total Ig, obtained by salt precipitation, were fractionated by preparative liquid isoelectric focusing (IEF) at various pH ranges. From each antiserum a number of fractions were obtained with significantly different isoelectric points. Many major fractions had reduced electrophoretic heterogeneity when compared with the Ig isolated before IEF. These fractions were tested for isoelectric purity by analytical IEF in polyacrylamide gels and by preparative refocusing over a narrow pH range. After complete reduction and alkylation, the light and heavy polypeptide chains of the focused antibody fractions were examined both by disc electrophoresis in alkaline urea gels and by IEF in polyacrylamide gels containing urea. From each antiserum, a number of fractions were obtained which yielded single light chains often with different electrophoretic mobilities. This method provided a successful means of preparatively obtaining different antibody fractions from a single antiserum.
A new, simple method for the preparation of lymphocytes bearing specific receptors
Authors: Haas W. , Schrader J. W. , Szenberg A.
Published: February 2007

Purification of antigen‐specific spleen cells using solid phase immunoadsorbents has two main difficulties: (1) unspecific binding of lymphoid cells to the adsorbent and (2) detachment of cells bound to the adsorbent without affecting cell viability and function. Both difficulties have been overcome by using gelatin as a matrix for cellular immunoadsorbtion. Mouse spleen cells were fractionated at 4 °C in rotating tubes coated with a thin layer of 2,4‐dinitrophenyl (DNP)‐gelatin or FGG (fowl IgG)‐gelatin. Bound cells could be recovered by melting the gel matrix at 37 °C without affecting cell viability. The specificity of the binding of a small subpopulation of spleen cells to the adsorbent has been shown by: (1.) inhibition of the binding with free antigen, (2.) depletion of DNP‐gelatin binding cells by serial fractionation, (3.) a specific increase of binding cells in spleen cell populations from immunized mice; and (4.) a 30‐fold enrichment in the binding cell population, of antigen‐binding cells as determined in an indirect antigen‐binding assay. The capacity of cell populations enriched in specific antigen‐binding cells, to respond to a T‐independent antigen DNP‐polymerized flagellin, was tested in an adoptive‐transfer system. No evidence could be obtained of an enrichment of DNP‐specific antibody‐forming cell precursors in populations of normal spleen cells that had been enriched for antigen‐binding cells.

Furthermore, the enrichment of antibody‐forming cell precursors from primed mice was only 4‐fold and thus not in accordance with the thirtyfold enrichment of antigen‐binding cells.

The failure to find the expected degree of functional enrichment in populations of cells that are greatly enriched for specific antigen‐binding cells is discussed.
Etude morphométrique de certaines structures nucléoprotéiques des noyaux de lymphocytes cultivés in vitro en présence de phytohémagglutinine
Authors: Valkov I. , Moyne G. , Robineaux R.
Published: February 2007

During blast transformation by phytohemagglutinin (PHA) of cultured guinea pig lymphocytes, a morphometric analysis of the variation in number of perichromatin granules relative to nuclear size and to decrements in the surface areas of condensed chromatin has been performed. Data were obtained by means of a Hewlett‐Packard 9810 A computer equipped with a device for quantitation of surface areas.

It was demonstrated that those cells capable of being transformed by PHA had significantly less perichromatin granules (both before and after transformation) than did nontransformed, cultivated cells, suggesting that T cells could be distinguished from B cells by this criterion. Consequently, avian lymphocytes were examined and it was found that lymphocytes obtained from the avian bursa of Fabricius contained more perichromatin granules than did those harvested from the thymus.

Both observations suggest that the number of perichromatin granules may be a sensitive index of lymphocyte type.
Restoration of the immune response to tobacco mosaic virus with homologous and heterologous thymus extracts in thymocyte‐depleted mice
Authors: Ströbel G.
Published: February 2007

Mice are unable to form detectable antibodies to tobacco mosaic virus (TMV) after thymectomy and anti‐thymocyte serum treatment. These mice, when substituted with extracts of mouse or calf thymus, however, develop TMV‐specific humoral antibodies. On the basis of its behavior in dialysis and gel filtration, the biological activity is judged to be of low molecular weight.

The mode of action of this substitution therapy is discussed in terms of the differentiation of precursor cells into functional T cells.
Generation of antibody dieversity. IV. Variation within single clones of antibody‐forming cells developing in vivo
Authors: Pilarski Linda M. , Cunningham A. J.
Published: February 2007

Previous experimental work demonstrated that clonal variation occurs in vitro. The present experiments were designed to test for clonal variation in vivo. B cells were transferred at limiting dilution, with antigen, into irradiated recipients. Seven days later spleens were assayed for plaque‐forming cell (PFC) colonies. Control experiments showed that these PFC colonies were clones, that is, they were derived from a single B cell precursor. When the clones were analyzed for heterogeneity of the PFC population, using cross‐reactivity on various mixtures of red blood cells as a method of detecting differences in antibody specificity, form 23–83 % of the clones contained variants. By adjusting the amounts of helper activity and antigen available to a developing clone, we have been able to influence this variation; high levels of help and/or antigen favour pure clones, while low levels of either produce mainly mixed clones.
The association of H‐2 antigens and EAC receptors on the surface of peritoneal cells
Authors: Schlesinger M. , Chaouat M.
Published: February 2007

The exposure of murine peritoneal cells to anti‐H‐2 sera results in a diminished expressoion of H‐2 antigen on the cell surface. Concomitant with this „H‐2 modulation”︁ the capacity of macrphages to bind sheep red blood cells coated with antibody and complement (EAC) was markedly diminished. In contrast, there was no change in the capacity of modulated macrophages to bind sheep red blood cells coated with antibody alone (EA). Antibodies to K end H‐2 specificities were more effective in reducing the binding of EAC than antibodies to D end H‐2 specificities. Exposure of peritoneal cells to θ or Ly antisera had no effect on the formation of EAC rosettes. Exposure of pertioneal cells to anti‐H‐2 sera, under conditions which would not allow moudulation of H‐2 antigens, also prevented the reduction of EAC binding. Thus, the EAC receptors and H‐2 antigenic specificities seem to be closely related on the surface of peritoneal cells, but constitute distinct cell surface structures. Perliminary evidence indicates that vinblastine, a microtubule depolymerizing agent, may disrupt the close association of EAC receptors and H‐2 antigens. It is suggested that the association of EAC receptors and K end H‐2 determinants on the membrane of macrphages may have implications for the regulations of the immune response by H‐2‐linked Ir genes.
Stimulation and inhibition of DNA synthesis in rat thymocytes: Action of concanavalin A and wheat germ agglutinin
Authors: Karsenti E. , Bornens M. , Avrameas S.
Published: February 2007

Wheat germ agglutinin, which has been found unable to stimulate rat thymocytes, is shown to strongly inhibit DNA synthesis of normal as well as concanavalin A‐stimulated cells.
Immunoglobulin determinants on the surface of lymphoid cells of carps
Authors: Emmrich F. , Richter R. F. , Ambrosius H.
Published: February 2007

Immunoglobulin determinants were detected by indirect immunofluorescence on the surface of numerous lymphocytes of perpheral blood, spleen, and pronephros of craps. The most interesting finding was the high proportion (65–68 %) of Ig+ lymphocytes in the thymus of early adult carps, possibly related to thymus function.
Differing mechanisms of tolerance and desensitization to dinitrochlorobenzene in guinea pigs
Authors: Polak L. , Geleick H.
Published: February 2007

In the present paper the mechanisms of tolerance and desensitization to dinitrochlorobenzene (DNCB) contact sensitivity in guinea pigs were investigated using the methods of adoptive sensitization of tolerant and normal syngeneic recipients and cyclophosphamide‐treatment of tolerant animals known to selectively inactivate suppressor lymphocytes.

It was shown that desensitization of presensitized animals is caused by the direct effect of the intravenously injected hapten on the effector cells in the peripheral compartment. The immediate onset of unresponsiveness and its very short duration almost exclude the possible involvement of enhancing antibodies or suppressor cells.

In the case of tolerance induced by pretreatment with dinitrobenzenesulfonic acid, suppressor cell activity is enhanced, preventing normal specific immunocompetent cells from recognizing the antigen and/or proliferating in the draining lymph nodes. Whether suppressor lymphocytes are of the B or T type is not yet known.
Characteristics of immunological memory in mice. II. Resistance of nonrecirculating memory cells to antigen‐mediated suppression of the secondary antibody response
Authors: Inchley C. J. , Black S. J. , Mackay Elizabeth A.
Published: February 2007

Mice were primed and subsequently challenged at various times with subcutaneous injections of sheep erythrocytes, and some characteristics of the secondary responses in the draining brachial and axillary lymph nodes were investigated. It was found that the secondary response within primed nodes was resistant to immunological preemption, a competition‐like phenomenon which severely depresses primary responses. Since it was also shown that circulating memory cells could be inhibited by preempting injections of antigen, it was concluded that the resistance of primed nodes to preemption was due to the presence within them of a nonrecirculating subpopulation of memory cells. The size of this population was dependent both on the amount of priming antigen and the time after priming.

The observation that the response given by these cells remained unaffected by doses of antigen which could depress a primary response does not favor the view that suppression of immune responses by preemption or antigenic competition is due to a factor which acts directly and indiscriminately on all immunologically competent cells.
The immunological properties of haptens coupled to thymus‐independent carrier molecules. III. The role of the immunogenicity and mitogenicity of the carrier in the induction of primary IgM anti‐hapten responses
Authors: Klaus G. G. B. , Janossy G. , Humphrey J. H.
Published: February 2007

Hapten (DNP‐lys) conjugates of two putatively nonimmunogenic polymers, hyaluronic acid and poly‐γ‐D‐glutamic acid, induce significant primary IgM anti‐DNP responses in C3H mice. Preparations of various immunogenic (Type 3 pneumococcal polysaccharide (SIII), levan, E. coli lipopolysaccharide) and nonimmunogenic (hyaluronic acid and poly‐glutamic acid) polymers were tested for their ability to act as polyclonal mitogens in vitro. In serum‐containing spleen cell cultures, only lipopolysaccharide stimulated substantial cell proliferation. In serum‐free medium, and using high specific activity [3H]thymidine, lipopolysaccharide, levan, SIII and to a lesser degree hyaluronic acid induced significant thymidine incorporation. However, under the latter conditions cell survival and proliferation were much less impressive. There was no apparent correlation between the capacity of various polymers to induce lymphocyte proliferation and their „potency”︁ as carriers for the generation of a primary IgM anti‐DNP response. Furthermore while low doses of lipopolysaccharide elicited „polyclonal”︁ antibody formation in vivo, high doses of SIII, levan and hyaluronic acid did not.

These results indicate that T cell‐independent B cell triggering is dependent on the polymeric nature of the antigen, and that polymers need not be immunogenic or mitogenic to act as carriers for the induction of primary IgM anti‐hapten antibody responses.
„Natural”︁ killer cells in the mouse. I. Cytotoxic cells with specificity for mouse Moloney leukemia cells. Specificity and distribution according to genotype
Authors: Kiessling R. , Klein Eva , Wigzell H.
Published: February 2007

In the spleens of young, adult mice there exist naturally occurring killer lymphocytes with specificity for mouse Moloney leukemia cells. The lytic activity was directed against syngeneic or allogeneic Moloney leukemia cells to a similar extent, but was primarily expressed when tested against in vitro grown leukemia cells. Two leukemias of non‐Moloney origin were resistant and so was the mastocytoma line P815. Although killer activity varied between different strains of mice, the specificity of lysis was the same as indicated by competition experiments using unlabeled Moloney or other tumor cells as inhibitors in the cytotoxic assays. Capacity to compete and sensitivy to lysis by the killer cells were found to be highly positively correlated. Analysis of the kinetics of the cytotoxic assay revealed a rapid induction of lysis within one to four hours, arguing against any conventional in vitro induction of immune response. No evidence was found of soluble factors playing any role in the cytolytic assay.
Cell‐mediated cytotoxicity against ectromelia virus‐infected target cells. III. Role of the H‐2 gene complex
Authors: Gardner I. D. , Bowern Narelle A. , Blanden R. V.
Published: February 2007

The role of the H‐2 gene complex in expression of cytotoxicity exerted by specific ectromelia‐immune thymus‐derived (T) cells against ectromelia‐infected target cells was examined. A repertoire of inbred mouse strains (some congenic) including the H‐2 haplotypes k, d, b, s, q, the recombinant H‐2a (k|d) and F1 hybrids (k/b and d/b) were immunized with virus and their spleen cells tested 6 days later, at the peak of the primary response, against H‐2k, H‐2d and H‐2b target cells. Significant specific cytotoxicity occurred only when the immune cell donors and the target cells shared all or part of the same H‐2 gene complex. For example, H‐2a (k|d) immune cells killed both H‐2k and H‐2d target cells. There wasno detectable effect of the non‐H‐2 genetic background, H‐2 public specificities, or the M‐locus Target cells infected with ectromelia virus exhibited quantitative or qualitative changes (or both) in expression of normal H‐2 antigens as indicated by reduced susceptibility to killing by T cells activated against H‐2 antigens in mixed lymphocyte culture. These data are consistent with the hypothesis that T cells in this system are responding to virus‐induced, specific changes in antigens on infected cells which are controlled by genes in the H‐2 complex; these genes seem likely to be those coding for H‐2 private specificities, or genes closely linked to them.
Bispecific cells among IgM and IgG producers during the early phase of primary and secondary responses
Authors: Couderc J. , Birrien J. L. , Oriol R. , Bleux C. , Liacopoulos P.
Published: February 2007

Simultaneous immunization of mice with sheep (SRBC) and horse (HRBC) erythrocytes regularly resulted in the appearance of hemolytic plaque‐forming cells (PFC) specific for each type of erythrocyte and also of PFC lysing both types of erythrocytes.

After primary stimulation the highest number of bispecific cells (42/106 cells) was found among PFC as revealed by the direct procedure (IgM producers).

Among PFC enhanced with anti‐mouse Fab serum (IgG producers), bispecific cells were less numerous (8/106 cells). In preparations enhanced by anti‐mouse‐γFc serum which reveals IgG producers without inhibiting IgM antibody, the number of bispecific PFC equalled the sum of bispecific cells revealed by direct and anti‐Fab enhanced procedures.

The number of direct bispecific PFC during primary and secondary response was approximately the same, whereas the number of IgG‐producing, bispecific PFC increased considerably during the secondary response. Another difference was the time limitation of the appearance of bispecific cells: after primary immunization direct bispecific PFC were detected only on days 3, 4 and 5, but enhanced bispecific PFC were present from day 4 up to day 12. However, during the secondary reaction, bispecific PFC were detected by all three procedures only between days 3 and 6.

Studies on the cross‐reactivity between SRBC and HRBC gave negative results at the humoral levels, even when the mice were primed with a minimal amount of both erythrocytes and then two months later, boosted with one of them. Studies at the cellular level showed that after immunization with one antigen, only 0.4 to 0.7 direct or enhanced PFC/106 cells could simultaneously lyse both erythrocyte types. Thus, a hundred times more bispecific PFC were constantly found after double immunization of the animals. Moreover, sudden disappearance of all bispecific PFC on the 7th day after secondary stimulation makes it unlikely that all bispecific PFC are simply cross‐reacting cells.
Expression of an immunoglobulin VH gene in natural anti‐hapten antibodies
Authors: Mäkelä O. , Imanishi Thereza
Published: February 2007

Nonimmune sera of CBA and C57BL/6 mice had similar anti‐(4‐hydroxy‐3‐nitrophenyl)acetyl (NP) titers, but the fine specificities (relative affinities for cross‐reactive haptens (4‐hydroxy‐5‐iodo‐3‐nitrophenyl)acetyl (NIP) and (4‐hydroxy‐3,5‐dinitrophenyl)acetyl (NNP)) were very different. Natural anti‐NP antibodies of the C57BL/6 mice resembled immune anti‐NP antibodies in being heteroclitic without exception, while both normal and immune anti‐NP of the CBA mice were nonheteroclitic. Breeding studies suggested that the C57BL/6 trait of the natural antibodies was controlled by the same VH gene as the C57BL/6 trait of immune anti‐NP antibodies.
Antigen binding and idiotypic properties of reconstituted immunoglobulins G derived from homogeneous rabbit anti‐pneumococcal antibodies
Authors: Huser H. , Haimovich J. , Jaton J.‐C.
Published: February 2007

Recombinations and hybridizations of H and L‐chains derived from several homogeneous rabbit antibodies to type 3 pneumococcal polysaccharide (SIII) were carried out. All reconstitution experiments performed gave rise to genuine IgG molecules. Antigen‐binding studies and affinity measurements for a hexasaccharide ligand derived from SIII were made. In addition, heterologous antiidiotypic serum raised against one rabbit anti‐SIII antibody was used to measure the reconstitution of idiotypic determinants in hybrid immunoglobulin molecules.

The results show that full recovery of the antigen‐binding properties was obtained only when chains derived from the same antibody molecules were reassociated. Similarly, the complete regain of idiotypic determinants (studied in one antibody system) could only be demonstrated in the homologous recombinants. The pairing of an H‐chain with several heterologous L‐chains, which differed in 6–11 positions in the 3 hypervariable sections, led to the formation of hybrid IgG molecules which had an affinity at least 100‐fold lower than that of the parent antibody molecule and a number of hapten‐binding sites which did not exceed 0.30.