FLT3/FLK2 ligand promotes the growth of murine stem cells and the expansion of colony-forming cells and spleen colony-forming units

The effect of FLT3/FLK2 ligand (FL) on the growth of primitive hematopoietic cells was investigated using ThyloSca1+ stem cells. FL was observed to interact with a variety of factors to initiate colony formation by stem cells. When stem cells were stimulated in liquid culture with FL plus interleukin (IL)-3, IL-6, granulocyte colony-stimulating factor (G-CSF), or stem cell factor (SCF), cells capable of forming colonies in secondary methylcellulose cultures (CFU-c) were produced in high numbers. However, only FL plus IL-6 supported an increase in the number of cells capable of forming colonies in the spleens of irradiated mice (CFU-s). Experiments with accessory cell-depleted bone marrow (Lin- BM) showed that FL alone lacks significant colony-stimulating activity for progenitor cells. Nevertheless, FL enhanced the growth of granulocyte-macrophage progenitors (CFU-GM) in cultures containing SCF, G-CSF, IL-6, or IL-11. In these assays, FL increased the number of CFU-GM initiating colony formation (recruitment), as well as the number of cells per colony (synergy). Many of the colonies were macroscopic and contained greater than 2 x 10(4) granulocytes and macrophages. Therefore, FL appears to function as a potent costimulus for primitive cells of high proliferative potential (HPP). FL was also observed to costimulate the expansion of CFU-GM in liquid cultures of Lin- BM. In contrast, FL had no growth-promoting affects on progenitors committed to the erythrocyte, megakaryocyte, eosinophil, or mast cell lineages.

FLK-2/FLT-3 ligand regulates the growth of early myeloid progenitors isolated from human fetal liver

The effects of the recently identified FLK-2/FLT-3 ligand (FL) on the growth of purified human fetal liver progenitors were investigated under serum-deprived culture conditions. FL alone was found to stimulate modest proliferation in short-term cultures of CD34++ CD38+ lineage (Lin)- light-density fetal liver (LDFL) cells and the more primitive CD34++ CD38- Lin- LDFL cells. However, the low levels of growth induced by FL were insufficient for colony formation in clonal cultures. Synergism between FL and either granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) or KIT ligand (KL) was observed in promoting the growth of high-proliferative potential (HPP) colony-forming cells (CF) and/or low-proliferative potential (LPP)-CFC in cultures of CD34++ CD38+ Lin- and CD34++ CD38- Lin- LDFL-cells. FL, alone or in combination with other cytokines, was not found to affect the growth of CD34+ Lin- LDFL cells, the most mature subpopulation of fetal liver progenitors investigated. The growth of the most primitive subset of progenitors studied, CD34++ CD38- Lin- LDFL cells, required the interactions of at least two cytokines, because only very low levels of growth were observed in response to either FL, GM-CSF, IL-3 or KL alone. However, the results of delayed cytokine-addition experiments suggested that individually these cytokines did promote the survival of this early population of progenitors. Although two-factor combinations of FL, KL, and GM-CSF were observed to promote the growth of early progenitors in a synergistic manner, neither of these factors was found to make fetal liver progenitors more responsive to suboptimal concentrations of a second cytokine. Only myeloid cells were recovered from liquid cultures of CD34++ CD38- Lin- LDFL cells grown in the presence of combinations of FL, KL, and GM-CSF. These results indicate that FL is part of a network of growth factors that regulate the growth and survival of early hematopoietic progenitors.

Hallerman-Streiff syndrome

A 3 day old female neonate with Hallerman Streiff Syndrome presented with white spots in both the eyes. Both eyebrows and eyelashes were found to be sparse. Anterior chamber was found to be shallow. Total cataract was detected with posterior synechiae. Fundus could not be viewed. General examination revealed other features of Hallerman-Streiff Syndrome--short stature, bird like face, atrophy of skin and natal teeth. Lensectomy was carried out for left eye at the age of 10 weeks. However, the child had repeated respiratory tract infections and died at the age of 22 weeks.

Inhibition of Th1 responses prevents inflammatory bowel disease in scid mice reconstituted with CD45RBhi CD4+ T cells

We have described a murine model of IBD that was induced in C.B-17 scid mice by transfer of the CD45RBhi subpopulation of CD4+ T cells from normal BALB/c mice and could be prevented by cotransfer of the CD45RBlo CD4+ T cell subset. Here we have dissected the mechanism of pathogenesis of IBD in this model and used this information for rational immunotherapy of the disease. CD4+ cells from diseased mice displayed a highly polarized Th1 pattern of cytokine synthesis upon polyclonal stimulation in vitro. The administration of anti-IFN gamma MAb to mice soon after T cell transfer prevented development of colitis for up to 12 weeks. Continual neutralization of TNF with anti-TNF MAbs reduced the incidence of severe disease; however, neutralization of TNF during only the first 3-4 weeks had no effect. Severe colitis was completely abrogated in mice treated systemically with rIL-10, but not with rIL-4.

False aneurysm following modified Blalock-Taussig shunt

A nine month old infant with life threatening tracheal compression due to a Blalock-Taussig shunt aneurysm is described. Successful surgical management is discussed.

Effect of lipid supplements on the production and glycosylation of recombinant interferon-gamma expressed in CHO cells

The effects of lipids on the glycosylation of recombinant human interferon-gamma expressed in a Chinese Hamster Ovary cell line were investigated in batch culture. Lipids form an essential part of the N-glycosylation pathway, and have been shown to improve cell viability. In control (serum-free) medium the proportion of fully-glycosylated interferon-gamma deteriorated reproducibly with time in batch culture, but the lipoprotein supplement ExCyte was shown to minimise this trend. Partially substituting the bovine serum albumin content of the medium with a fatty-acid free preparation also improved interferon-gamma glycosylation, possibly indicating that oxidised lipids carried on Cohn fraction V albumin may damage the glycosylation process.

Continuous administration of anti-interleukin 10 antibodies delays onset of autoimmunity in NZB/W F1 mice

We have previously shown that continuous administration of anti-interleukin 10 (anti-IL-10) antibodies (Abs) to BALB/c mice modifies endogenous levels of autoantibodies, tumor necrosis factor alpha (TNF-alpha), and interferon gamma, three immune mediators known to affect the development of autoimmunity in "lupus-prone" New Zealand black/white (NZB/W)F1 mice. To explore the consequences of IL-10 neutralization in NZB/W F1 mice, animals were injected two to three times per week from birth until 8-10 mo of age with anti-IL-10 Abs or with isotype control Abs. Anti-IL-10 treatment substantially delayed onset of autoimmunity in NZB/W F1 mice as monitored either by overall survival, or by development of proteinuria, glomerulonephritis, or autoantibodies. Survival at 9 mo was increased from 10 to 80% in anti-IL-10-treated mice relative to Ig isotype-treated controls. This protection against autoimmunity appeared to be due to an anti-IL-10-induced upregulation of endogenous TNF-alpha, since anti-IL-10-protected NZB/W F1 mice rapidly developed autoimmunity when neutralizing anti-TNF-alpha Abs were introduced at 30 wk along with the anti-IL-10 treatment. Consistent with the protective role of anti-IL-10 treatment in these experiments, continuous administration of IL-10 from 4 until 38 wk of age accelerated the onset of autoimmunity in NZB/W F1 mice. The same period of continuous IL-10 administration did not appear to be toxic to, or cause development of lupus-like autoimmunity in normal BALB/c mice. These data suggest that IL-10 antagonists may be beneficial in the treatment of human systemic lupus erythematosus.

Modulation of murine macrophage function by IL-13

Activated macrophages are important effector cells for immune response to many parasites and immune responses are strongly modulated in part by the effect of Th cell-derived cytokines on macrophages. Th1-derived cytokines such as IFN-gamma are strong stimulators of macrophage activation, while cytokines produced by Th2 cells, including IL-4 and IL-10, have been shown under some conditions to inhibit macrophage activities associated with inflammatory responses. IL-13, a recently described cytokine produced by Th2 cells, is also capable of down-modulating macrophage activity in a manner similar to that previously described for IL-4. Treatment of activated macrophages with IL-13 reduces the production of inflammatory monokines in response to IFN-gamma or LPS, both potent stimulators of these factors. In addition, IL-13 decreases the production of nitric oxide by activated macrophages. Nitric oxide has been implicated in both macrophage cytotoxicity and macrophage-associated immunosuppression. The suppression of nitric oxide by IL-13 leads to a decrease in parasiticidal activity by activated macrophages. However, our data indicate that IL-13 has pleiotropic effects, while the inflammatory potential of activated macrophages is significantly reduced, the potential of other macrophage subsets is unimpaired. These data indicate that IL-13 could be a potent modulator of immune responses in vivo, with effects that may embrace both macrophage suppressive and macrophage potentiating functions.

Modulation of murine macrophage function by IL-13

Activated macrophages are important effector cells for immune response to many parasites and immune responses are strongly modulated in part by the effect of Th cell-derived cytokines on macrophages. Th1-derived cytokines such as IFN-gamma are strong stimulators of macrophage activation, while cytokines produced by Th2 cells, including IL-4 and IL-10, have been shown under some conditions to inhibit macrophage activities associated with inflammatory responses. IL-13, a recently described cytokine produced by Th2 cells, is also capable of down-modulating macrophage activity in a manner similar to that previously described for IL-4. Treatment of activated macrophages with IL-13 reduces the production of inflammatory monokines in response to IFN-gamma or LPS, both potent stimulators of these factors. In addition, IL-13 decreases the production of nitric oxide by activated macrophages. Nitric oxide has been implicated in both macrophage cytotoxicity and macrophage-associated immunosuppression. The suppression of nitric oxide by IL-13 leads to a decrease in parasiticidal activity by activated macrophages. However, our data indicate that IL-13 has pleiotropic effects, while the inflammatory potential of activated macrophages is significantly reduced, the potential of other macrophage subsets is unimpaired. These data indicate that IL-13 could be a potent modulator of immune responses in vivo, with effects that may embrace both macrophage suppressive and macrophage potentiating functions.

Interleukin-4 and interleukin-10 synergize to inhibit cell-mediated immunity in vivo

The lack of cell-mediated (Th1-like) immunity that is often associated with strong humoral immune responses is thought to be due in part to the inhibition of Th1 effector function by the Th2-derived cytokine interleukin-10 (IL-10). This hypothesis, however, is based entirely on results from in vitro studies, wherein IL-10 has been shown to inhibit Th1 cytokine synthesis. In this study we have compared the regulatory effects of both IL-4 and IL-10 on the development of a more complex Th1 effector function in vivo, the development of delayed-type hypersensitivity (DTH) to Leishmania major in mice immune to Leishmania. The results revealed two findings unexpected from in vitro studies with Th1 clones. First, optimal inhibition of the DTH response (up to 70%), assessed by footpad swelling and leukocytic infiltration, required the combination of IL-4 and IL-10, indicating that these two activities synergized to inhibit DTH reactivity. Second, IL-4 inhibited interferon-gamma (IFN-gamma) production by lymph node cells draining the site of antigen challenge as well as did IL-10. The combination of both cytokines was no more effective than either alone. The mechanism by which IL-4 and IL-10 acted to inhibit DTH responses did not appear to be through inhibition of IFN-gamma or tumor necrosis factor production as treatment with antibodies which neutralized these activities failed to inhibit DTH responses. Inhibition of the DTH with IL-4 and IL-10 is the most effective specific regulator of DTH responses reported and the only one capable of modulating tuberculin DTH. These data establish IL-4 and IL-10 as potent inhibitors of Th1 effector function in vivo and suggest their utility in controlling deleterious Th1-mediated inflammatory responses such as occur in some infectious and autoimmune diseases.

Interleukin 10 protects mice against staphylococcal enterotoxin B-induced lethal shock

We investigated the ability of interleukin 10 (IL-10) to protect mice against lethal shock induced by staphylococcal enterotoxin B (SEB). Treatment of mice with IL-10 prevented the death of mice injected with SEB in a dose-dependent manner. IL-10-mediated protection was apparent when administered either prior to or concurrent with SEB but was less effective when administered following SEB injection. This observation indicates that IL-10 is capable of regulating T-cell activation in vivo.

Abdominal pregnancy

Two cases of Abdominal pregnancy are reported: one from the Castle Street Hospital for Women, Colombo, Sri-Lanka and the other from the Queen Elizabeth Hospital, Barbados, West Indies. The clinical manifestations, diagnosis and management are described. A review of the literature is presented.

Interleukin-4 and interleukin-10 synergize to inhibit cell-mediated immunity in vivo

The lack of cell-mediated (TH1-like) immunity that is often associated with strong humoral immune responses is thought to be due in part to the inhibition of Th1 effector function by the Th2-derived cytokine interleukin-10 (IL-10). This hypothesis, however, is based entirely on results from in vitro studies, wherein IL-10 has been shown to inhibit Th1 cytokine synthesis. In this study we have compared the regulatory effects of both IL-4 and IL-10 on the development of a more complex Th1 effector function in vivo, the development of delayed-type hypersensitivity (DTH) to Leishmania major in mice immune to Leishmania. The results revealed two findings unexpected from in vitro studies with Th1 clones. First, optimal inhibition of the DTH response (up to 70%), assessed by footpad swelling and leukocytic infiltration, required the combination of IL-4 and IL-10, indicating that these two activities synergized to inhibit DTH reactivity. Second, IL-4 inhibited interferon-gamma (IFN-gamma) production by lymph node cells draining the site of antigen challenge as well as did IL-10. The combination of both cytokines was no more effective than either alone. The mechanism by which IL-4 and IL-10 acted to inhibit DTH responses did not appear to be through inhibition of IFN-gamma or tumor necrosis factor production as treatment with antibodies which neutralized these activities failed to inhibit DTH responses. Inhibition of the DTH with IL-4 and IL-10 is the most effective specific regulator of DTH responses reported and the only one capable of modulating tuberculin DTH. These data establish IL-4 and IL-10 as potent inhibitors of Th1 effector function in vivo and suggest their utility in controlling deleterious Th1-mediated inflammatory responses such as occur in some infectious and autoimmune diseases.

Closing behavior of a new bileaflet mechanical heart valve

Recently, the in vivo cavitation potential has become a primary concern among manufacturers of new mechanical heart valves (MHV). An experimental/computational program was designed to investigate each of the flow parameters involved. It was established that the closing velocity of the leaflet holds the key to MHV cavitation. One of the novel concepts of the new bileaflet mechanical heart valve (1205-MHV) was its ability to operate with a relatively small angular excursion that led to a much smaller closure velocity at impact (as compared with control valves). This is believed to significantly reduce the cavitation potential. The 1205-MHV is characterized by a longer valve body, with the hinges protruding further upstream. The unique design allows the valve the freedom to open as much as 90 degrees. The closure velocities are reduced by a smaller leaflet excursion (50 degrees), combined with a floating hinge that allows absorption of part of the impact energy at closure. The impact velocities of the 1205-MHV leaflets at closure were measured by a laser sweeping technique that monitored the leaflet closing motion with a precision of 5 microseconds within the last 3 degrees before impact. The 27 mm 1205-MHV (the largest size) was tested in the program by mounting the valve in the mitral position of a physiologic mock circulatory loop. The valve was tested at 70, 90, and 120 bpm. The results were compared with those of a St. Jude Medical 29 mm MHV. The closure velocities measured with the 1205-MHV were significantly lower than those measured with the control valve.(ABSTRACT TRUNCATED AT 250 WORDS)

The association of malignancy with SLE: an analysis of 150 patients under long-term review

We describe seven patients who developed malignancy before, after or at the onset of systemic lupus erythematosus (SLE). They comprise three cases of breast adenocarcinoma, two cases of Hodgkin's lymphoma, and one each of cholangiocarcinoma and thymoma. Only one of this group had been treated with cytotoxic agents, and five have subsequently died. They belonged to a group of 150 SLE patients, many of whom had been treated with steroids and cytotoxic agents, under long-term follow-up at a specialized lupus clinic. We discuss the reported association of malignancy in patients with SLE.

Interleukin 13, a T-cell-derived cytokine that regulates human monocyte and B-cell function

We have isolated the human cDNA homologue of a mouse helper T-cell-specific cDNA sequence, called P600, from an activated human T-cell cDNA library. The human cDNA encodes a secreted, mainly unglycosylated, protein with a relative molecular mass of approximately 10,000. We show that the human and mouse proteins cause extensive morphological changes to human monocytes with an associated up-regulation of major histocompatibility complex class II antigens and the low-affinity receptor for immunoglobulin E (Fc epsilon RII or CD23). In addition, they stimulate proliferation of human B cells that have been activated by anti-IgM antibodies or by anti-CD40 monoclonal antibodies presented by a mouse Ltk- cell line transfected with CDw32. Furthermore, the human protein induced considerable levels of IgM and IgG, but no IgA production, in cultures in which highly purified human surface IgD+ or total B cells were cocultured with an activated CD4+ T-cell clone. Based on these findings, we propose that this immunoregulatory protein be designated interleukin 13.

Interleukin 13 induces interleukin 4-independent IgG4 and IgE synthesis and CD23 expression by human B cells

Recently the cDNA encoding interleukin 13 (IL-13), a T-cell-derived cytokine, was cloned and expressed. The present study demonstrates that IL-13 induces IgG4 and IgE synthesis by human B cells. IL-13-induced IgG4 and IgE synthesis by unfractionated peripheral blood mononuclear cells and highly purified B cells cultured in the presence of activated CD4+ T cells or their membranes. IL-13-induced IgG4 and IgE synthesis is IL-4-independent, since it was not affected by neutralizing anti-IL-4 monoclonal antibody. Highly purified, surface IgD+ B cells could also be induced to produce IgG4 and IgE by IL-13, indicating that the production of these isotypes reflected IgG4 and IgE switching and not a selective outgrowth of committed B cells. IL-4 and IL-13 added together at optimal concentrations had no additive or synergistic effect, suggesting that common signaling pathways may be involved. This notion is supported by the observation that IL-13, like IL-4, induced CD23 expression on B cells and enhanced CD72, surface IgM, and class II major histocompatibility complex antigen expression. In addition, like IL-4, IL-13 induced germ-line IgE heavy-chain gene transcription in highly purified B cells. Collectively, our data indicate that IL-13 is another T-cell-derived cytokine that, in addition to IL-4, efficiently directs naive human B cells to switch to IgG4 and IgE production.

Interleukin 10 protects mice from lethal endotoxemia

Interleukin 10 (IL-10) decreases production of IL-1, IL-6, and tumor necrosis factor alpha (TNF-alpha) in vitro, and neutralization of IL-10 in mice leads to elevation of the same monokines. We test here whether this monokine-suppressing property of IL-10 confers on it the capacity to protect mice from lipopolysaccharide-induced shock, a monokine-mediated inflammatory reaction. A single injection of 0.5-1 microgram of recombinant murine IL-10 reproducibly protected BALB/c mice from a lethal intraperitoneal injection of endotoxin. This result was obtained whether the IL-10 was administered concurrently with, or 30 min after the injection of endotoxin. The protective effect of IL-10 was reversed by prior injection of neutralizing anti-IL-10 antibodies, and correlated with a substantial decrease in endotoxin-induced TNF-alpha release. These data implicate IL-10 as a candidate for treatment of bacterial sepsis, and more generally as an effective antiinflammatory reagent.

Combating aggression in institutionalized childern with physical exercise and music

The results of a short-term trial of combating aggression in 20 institutionalized children of both sexes in the age range of 10-14 years are presented in this paper. Vigorous physical exercise and learning vocal music were the two remedial therapies employed Results indicate that the experimental group significantly increased its Group Conformity Ratings after the treatment. As far as the direction of aggression is concerned, the experimental group significantly reduced its extra-punitive responses. On the reaction of frustration, the experimental group improved its ego-strength after the treatment. The results are indicative of a better level of adjustment by the experimental group as a result of the therapies.