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The alarming increase in the incidence of Gram-positive infections, including those caused by resistant bacteria, has sparked renewed interest in novel antibiotics. One such agent is daptomycin, a novel lipopeptide antibiotic with proven bactericidal activity in vitro against all clinically relevant Gram-positive bacteria. These include resistant pathogens, such as vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide intermediately susceptible Staphylococcus aureus (GISA), coagulase-negative staphylococci (CNS) and penicillin-resistant Streptococcus pneumoniae (PRSP), for which there are very few therapeutic alternatives. Daptomycin provides rapid, concentration-dependent killing and a relatively prolonged concentration-dependent post-antibiotic effect in vitro. Spontaneous acquisition of resistance to daptomycin occurs rarely. Daptomycin exhibits linear pharmacokinetics, minimal accumulation with once-daily dosing, and low plasma clearance and volume of distribution. Phase II clinical trials indicate that daptomycin at doses of 2 mg/kg q24 h and 3 mg/kg q12 h is efficacious against skin and soft tissue infections and bacteremia, respectively. In addition, results in endocarditis suggested potential efficacy with higher doses. On the basis of clinical trials to date, it appears that daptomycin has an excellent safety profile, with the incidence and nature of serious adverse events comparable to those observed with conventional therapy. Adverse events associated with other classes of antimicrobials (nephrotoxicity, local irritation, ototoxicity, hypersensitivity, and gastrointestinal effects) were uncommon with daptomycin. Minimal skeletal muscle toxicity was seen at only the highest dose tested (4 mg/kg q12 h), predicted by elevations in serum creatinine phosphokinase, and readily reversible upon discontinuation of treatment. There were no signs of toxicity in cardiac or smooth muscle. Phase II and III clinical trials are underway to evaluate daptomycin for the treatment of Gram-positive bacteremia and complicated skin and soft tissue infections, respectively. Daptomycin holds promise as a rapidly acting and highly effective antibiotic for Gram-positive infections.

The present study was undertaken to investigate the interaction of IL-7 and sCD23 on human peripheral blood T cell activation and CTL differentiation. Purified T lymphocytes were stimulated with mitogen plus IL-2 and subcultured for 7 days with IL-7 and/or sCD23. The combination of IL-7 and sCD23 synergistically enhanced the proliferation of both CD4+ and CD8+. T cells. CD8+ T cells, however, were usually more responsive to IL-7 and sCD23. This synergy was observed on both subsets of T cells. Furthermore, these cytokines synergistically augment the CTL activity of CD8+ T cells in both mitogen- and antigen-activated T cells. MAbs anti-IL-2 or anti-IL-2R (CD25) and anti-IL-12 had no effect on T cell proliferation and CD8+ cytotoxic activity induced by IL-7 and sCD23. We analyzed the effect on IFN-gamma induction by CD8+ T cells and found that IL-7 alone was incapable of inducing detectable levels of IFN-gamma production, but together with sCD23 it enhanced the production of IFN-gamma. We also found that IFN-gamma was not required for enhanced CTL activity of CD8+ T cells, because rabbit anti-IFN-gamma did not block the synergistic effects of either cytokine. The data demonstrate that the synergistic stimulatory activity of IL-7 and sCD23 may be of significance in the human CTL development and provide an alternative mechanism of stimulating T cells for use in immunotherapy.

Background: The low affinity receptor for IgE, CD23, has been described in several pathological conditions. However, the factors involved in the upregulation or downregulation of this receptor are still debated., Methods and Results: We studied the effect of interleukin 7 (IL-7) on the expression of CD23 in normal PBT cells stimulated with PMA + Ca2. The data indicate that activated PB-T cultured in the presence of IL-7 showed an increased expression of CD23. The induction of IL-7 on CD23 production appears to be independent of IL-2, IL-4, IL-9, IL-15. Indeed, the addition of specific MoAbs anti-IL-2, IL-4, IL-9, IL-15 or anti-IL2R was unable to block the effect of IL-7 on CD23. The addition of IL-7 to a specific subset CD4+ CD23+ was able to augment the adhesiveness of T cells to parenchymal cell monalayers. The use of different cytokine (IL-2, IL-4, IL-9, IL-15) resulted in no increase of adhesiveness. In contrast the addition of IL-7 to a different T-cell subset (i.e. CD4+ CD23-) was unable to rescue the lack of adhesiveness observed in these cells. Blocking experiments with MHM6 MoAb were able to drastically reduce the adhesiveness observed in CD4+ CD23+ subsets. The presence of LFA-1 and VLA-4 adhesion molecules were responsible for the augmented adhesiveness of activated CD4+ CD23+ T cells cultured in the presence of IL-7. Blocking experiments with anti-LFA-1, VLA-4, anti-LFA-1beta plus VLA-4alpha MoAbs or anti-ICAM-1 MoAb added to the monolayers resulted in a complete inhibition of adhesion to parenchymal monolayers. In contrast, the addition of anti-IL-7 or anti-IL-7R MoAbs were able to block the augmented adhesiveness of CD4+ CD23+ cells to monolayers observed in the presence of IL-7., Conclusion: Taken together these findings point to the likelihood that IL-7 is responsible for the observed quantitative difference in the level of adhesion molecules and may open a new role of CD23 in the immune regulation.

The role played by CD23 in retroviral infections is still unclear. The synergistic effects of interleukin 7 (IL-7) and sCD23 on T cell proliferation and the generation of HIV-1-specific cytotoxic T lymphocytes (CTL) in mitogen- and antigen-stimulated systems were examined. Addition of IL-7 and sCD23 at the onset of culture resulted in a marked augmentation of T cell proliferation and cytotoxic activity. Studies of CTL development in purified mitogen CD8+ T cells demonstrated that IL-7 and sCD23 could act directly on the CD8+ lymphocyte subset to augment cytotoxicity. The data demonstrate that IL-7 and sCD23 synergistically augmented CTL activity independently of IL-2 and IL-12. We analyzed the effects on IFN-gamma production by CD8+ T cells and found that IL-7 alone did not induce detectable levels of IFN-gamma production, but together with sCD23, it synergistically enhanced the production of IFN-gamma. We also found that IFN-gamma appeared not to be required for the enhanced CD8+ CTL activity because rabbit anti-IFN-gamma antibody did not block the synergistic effects of IL-7 and sCD23. These results indicate that IL-7 and sCD23 can exert major upregulatory effects on human CTL development and suggest that these effects are both proliferative and differentiative.

The purpose of this study is to elucidate the effect of interleukin-7 (IL-7) and soluble CD23 (sCD23) on Phorbol12 Myristate13 Acetate (PMA) activated CD4+ TCR alpha beta+ cells of HIV-1 infected subjects. CD23 and IL-7R were detectable on activated CD4+ T cells of these subjects by FACS. Addition on IL-7 (1000 U/ml), at the onset of cultures, resulted in a significant increase of CD23 expression. We also demonstrated that T cells proliferation and CD23 expression in the presence of exogenous IL-7 occur in an IL-2 independent manner. Addition of IL-7 and sCD23 to activated CD4+ cells of HIV-1 infected subjects induced a proliferative response of TCR alpha beta cells. In contrast, addition of either sCD23 or IL-7 to activated CD4+ T cells did not result in an increase of TCR alpha beta expression. The data provide direct evidence that sCD23 in combination with IL-7 induce proliferation of activated CD4+ T cells of HIV-1 infected subjects to augment TCR alpha beta expression. These results support the possibility that IL-7 plus sCD23 might play an important role in the modulation of TCR alpha beta expression in HIV infection.

We have previously demonstrated that rat liver nuclei contain PI-PLC beta1 and gamma1 in the inner nuclear matrix and lamina associated with specific phosphodiesterase activity (Bertagnolo et al., 1995, Cell Signall. 7, 669-678). Since compensatory hepatic growth is an informative and well characterized model for natural cell proliferation, the presence of specific PI-PLC isoforms and their activity as well as PIP2 recovery were studied at various regenerating times, ranging from 3 to 22 h after partial hepatectomy. Three PI-PLC isoforms (beta1, gamma1, delta1) were examined in control and regenerating liver cells by using specific antibodies. By means of in situ immunocytochemistry and confocal microscopy, PI-PLC beta1 was found mainly in the nucleoplasm and this pattern was not modified after hepatectomy. On the contrary, the nuclear gamma1 isoform showed a marked decrease at 3 and 16 h after hepatectomy, but a clear increase at 22 h covering with bright intensity the whole nucleus. The PI-PLC delta1 isoform, which is exclusively cytoplasmic, was not altered during rat liver regeneration. By western blotting analysis on whole cell homogenates, none of the PI-PLC isozymes under study showed proliferation-linked modification. However, analyses of isolated nuclei identified changes in the nucleus associated PI-PLC gamma1 that paralleled the in situ observation whereas the beta1 isoform was unmodified at all the times examined. Nuclear phosphodiesterase activity on PIP2 was lower at 3 and 16 h, in comparison with sham operated rats, increased at 6 h and reached the highest value after 22 h. Consistently, the recovery of PIP2, obtained in conditions that optimise PIP-kinase activity, showed a marked decrease at 3 h and an increase up to 16 h of liver regeneration, followed by a further decrease at 22 h. These data are consistent with a close relationship between cell proliferation and the nuclear inositide cycle, depending, in rat liver, predominantly on the modulation of the gamma1 isoform of PI-PLC.

The expression of CD23 on PHA-activated human PBT (peripheral blood T) cells of healthy donors was investigated. It appears that CD23 is expressed solely on activated CD4+ T cells. Cytofluorotometric analysis revealed that 6% of PHA-activated CD4+ T cells expressed CD23, while unstimulated CD4+ T cells express no detectable CD23. The addition of IL-7 (1000 U/ml) to activated CD4+ T cells resulted in a marked augmentation of CD23 expression (29%). CD23 expression was blocked by M20 and M26 mAbs, but no reduction was detected by anti-IL-2R (CD25) mAb. This suggests that IL-7 has a specific regulatory effect on CD23 expression independent of IL-2. Northern Blot analysis showed a marked increase of CD23 mRNA detected in PHA-activated CD4+ T cells plus IL-7. IL-7 was also able to upregulate the expression of HLA-DR on activated CD4+ T cells. Optimal HLA-DR and CD23 induction by IL-7 occurred at 48 and 72 h of culture. The addition of CHX revealed that the induction of CD23 and HLA-DR by IL-7 required intact protein synthesis. Furthermore, PHA activated CD4+ T cells cultured in the presence of IL-7 are polarized to a Th-2 pattern of cytokine production.

The low-affinity receptor for IgE, CD23, has been described in several pathological conditions. However, the factors involved in the upregulation or downregulation of this receptor are still debated. We studied the effect of interleukin 7 (IL-7) on the production of CD23 in normal PBT cells stimulated with PMA + Ca2. The results demonstrate that cytoplasmic CD23 level was significantly augmented by costimulation with PMA + Ca2 plus IL-7 (1000 U/ml). Using an intracytoplamatic cytometric analysis, an accumulation of intracellular CD23 was observed at 48 hr in the presence of IL-7. This appears to have a profile different from the CD23 surface expression peaking at 72 hr of culture. We were also able to show that sCD23 was specifically increased by IL-7 and occurred with an early peak at 72 hr and a late peak at 120 hr of culture. The increased release and the biphasic production of sCD23 may reside in an accelerated degradation of the receptor due to an excessive accumulation of it. Restimulation of CD4+ T cells with PMA + Ca2 without IL-7 changed the profile of sCD23 production showing a second peak at 144 hr of culture. The induction of IL-7 on CD23 production appears to be independent of IL-2, IL-4, IL-9, and IL-15. Indeed, the addition of specific mAbs anti-IL-2, -IL-4, -IL-9, -IL-15, or anti-IL-2R was unable to block the effect of IL-7 on CD23. The addition of IL-7 to specific subset CD4+CD23+ was able to augment the adhesiveness of T cells to parenchymal cell monolayers. The use of different cytokine (IL-2, IL-4, IL-9, IL-15) resulted in no increase of adhesiveness. In contrast, the addition of IL-7 to a different T cell subset (i.e., CD4+CD23-) was unable to rescue the lack of adhesiveness observed in these cells. The adhesion molecules LFA-1 and VLA-4 were responsible for the augmented adhesiveness of activated CD4+CD23+ T cells cultured in the presence of IL-7. Blocking experiments with anti-LFA-1beta, VLA-4alpha, anti-LFA-1beta plus VLA-4alpha mAbs, or anti-ICAM-1 mAb added to the monolayers resulted in a complete inhibition of adhesion to parenchymal monolayers. In contrast, the addition of anti-IL-7 or anti-IL-7R mAbs was able to block the augmented adhesiveness of CD4+CD23+ cells to monolayers observed in the presence of IL-7. A significant augmentation of LFA-1 and VLA-4 was observed in cells cultured in the presence of IL-7. Taken together these findings point to the likelihood that IL-7 is responsible for the observed quantitative difference in the level of adhesion molecules and may open a new role of CD23 in the immune regulations.

Despite evidence for the expression of the low-affinity Fc receptor for IgE (Fc epsilon RII/CD23) in several pathological conditions, the role played by CD23 in normal human T cells is still unclear. We studied the effect of a stomal-derived cytokine, interleukin (IL-7), on the expression of CD23 in human T cells stimulated with 10 micrograms/ml phytohemagglutinin (PHA). The results demonstrate that IL-7 did not induce CD23 expression in the resting T cells. However, PHA-induced CD23 expression was enhanced by costimulation with IL-7 (1,000 U/ml). Cytofluorometric analysis revealed that CD23 expression in activated T cells was enhanced by the addition of IL-7 (from 2% to 18%). It was also observed that the effect of IL-7 on CD23 expression is exclusively on CD4+ T cells. The enhanced expression of CD23 was blocked by an anti-IL-7 monoclonal antibody (mAb), but not by IL-2 and IL-4 mAbs. This suggests that IL-7 is a potent regulatory cytokine capable of acting independently of IL-2 and IL-4 in the expression of CD23. Northern blot analysis showed an increase in CD23 mRNA when activated T cells were cultured in the presence of IL-7. A significant increase in receptor numbers on activated T cells was detected by Scatchard analysis when IL-7 was added to the cell cultures. The induction of CD23 expression by IL-1, IL-3, IL-4, IL-5, IL-6, interferon-8 and OKT3 on PHA-activated T cells was not of the same magnitude as observed in the presence of IL-7. These results demonstrate a selective induction of CD23 expression on activated human T cells cultured in the presence of IL-7. These data indicate that the stromal-derived growth factor points to an important role of CD23 in the regulatory network of the immune response.

To establish whether protein kinase C was involved in the nuclear events underlying cell differentiation and proliferation, rat pheochromocytoma PC12 cells, serum-starved for 24 h, were treated with either differentiating doses of nerve growth factor or high serum concentrations, which represented a powerful mitogenic stimulus. Western blot analysis with isoform-specific antibodies, performed on whole cell homogenates, cytoplasms, and purified nuclei, showed that PKC isotypes alpha, beta I, beta II, delta, epsilon, eta, and zeta were expressed in PC12 cells and that all of them, except for beta I, were found at the nuclear level, variably modulated depending on the cell treatment. Compared to serum-stimulated cells, in which an early (1 day) and marked rise of protein kinase C activity was followed by a plateau, nerve growth factor-treated cells showed a progressive increase of protein kinase C activity coincident with the onset and maintenance of the differentiated phenotype. Western blot analysis of nuclei isolated from fully differentiated cells demonstrated an increase of protein kinase C alpha, paralleled by enhanced phosphotransferase activity along with the nerve growth factor treatment, and complete loss of the delta isotype. In contrast, in nuclei of proliferating PC12 cells, after an early but modest increase at 1 day of mitogenic stimulation, protein kinase C activity reached a plateau. Isotype-specific analysis indicated a concomitant increase of protein kinase C beta II, delta, and zeta and the appearance of protein kinase C epsilon and eta at the nuclear level. Considering the relative intensity of the cytoplasmic and nuclear immunoreactive bands under the three conditions examined, clear-cut translocation to the nucleus occurred for PKC epsilon and eta in serum-stimulated cells. Additional nuclear accumulation of PKC by translocation from the cytoplasm was prominently induced for the zeta isoform after mitogenic stimulation and for PKC alpha during prolonged NGF treatment. Our data suggest that nuclear translocation and selective activation of distinct protein kinase C isoforms play a relevant role in the control of proliferation and differentiation of the same cell type and that nuclear protein kinase C is crucial to the induction and persistence of the differentiated neuronal phenotype of PC12 cells.

Purpose: We studied the validity of ultrasonography for short-term followup in pediatric urology., Materials and Methods: The study group comprised 137 children (187 urinary tracts) undergoing surgery at our hospital for congenital urological pathology between February 1982 and July 1992. The study protocol designed to evaluate urinary tract dilation postoperatively and monitor its progress, included ultrasound at discharge from the hospital, and repeat ultrasound between days 20 and 30, and days 45 and 60. Diuretic renography or excretory urography was indicated when urinary tract dilatation showed no signs of regressing or had increased on 2 consecutive evaluations. Ultrasound of the urinary tract was done to evaluate variations in the grade of dilatation of the pelves, calices, infundibula and ureters, and grade of hydronephrosis., Results: Variations in the grade of dilatation of the infundibula and ureters were early sensitive indicators of the absence of obstruction. Using this protocol only 15 of the 187 urinary tracts (8%) corrected surgically needed further evaluation for suspected iatrogenic stenosis, including 3 with obstruction that required reoperation. No other cases of obstruction were detected during long-term followup., Conclusions: A series of sonographic evaluations performed within a short period and the greater significance attributed to more specific parameters, such as grade of dilatation of the infundibula and ureters, make ultrasound a valid means of monitoring urological cases postoperatively.

The subcellular distribution of PI-PLC beta 1, gamma 1, and delta 1 has been investigated in rat liver by western blot and immunohistochemical analysis with a panel of isoform-specific antibodies. The data obtained in situ on cryo-sectioned tissue indicate that PI-PLC beta 1 is predominantly nuclear, while gamma 1 is largely cytoplasmic and delta 1 is sharply restricted to the cytoplasm. In fractionation experiments, the Western blot analysis indicated that the recovery of the nuclear isoforms beta 1 and gamma 1 was not affected by the removal of the nuclear membrane, and that the two enzymes persisted in nuclear matrix and lamina, obtained after nuclease digestion and extraction with high salt and detergent. The assay of the phosphodiesterase activity in different cell fractions correlates with the observed relative abundance of the enzymes, and specific inhibition with neutralizing anti-beta 1 and -gamma 1 isoforms confirms that these are the enzymes active at the nuclear level. These results demonstrate that in rat liver cells, as in other cell types, different members of the PI-PLC family show a discrete intracellular distribution, and suggest that PI-PLC beta 1 and gamma 1 play a central role in modulating the nuclear phosphoinositide cycle.

Virus-specific cytotoxic T lymphocytes (CTL) play a crucial role in modulating an immune response against human immunodeficiency type 1 (HIV-1) infection. The generation of effector cytotoxic cells from CTL precursors involves intricate interactions with antigen via T cell receptors (TcR) and soluble cytokines. Interleukin (IL)-7 can affect T cell maturation and differentiation. Here we report on a group of five HIV-1-positive individuals who tested negative for env- and gag-specific CTL activity. When exogenous recombinant human IL-7 was added as a stimulus to the cultures, none (0/5) of the CTL-negative individuals exhibited a CTL response. Individuals that were negative for HIV-1-specific CTL activity were found to lack IL-7 receptor (IL-7R) on CD8+ cells with a comparable reduction on CD4+ cells. Increased shedding of IL-7R in the culture supernatant was observed. A significant reduction in receptor number was detected by binding of 125I-labeled IL-7 and Scatchard analysis. The lack of IL-7R is probably not due to endogenous IL-7, since it was not detectable in the culture supernatants of the patients studied. HIV-1 proteins may cause down-modulation of IL-7R expression, either by producing an insufficient number of molecules or by rapid decay of IL-7R on T cells. These changes may alter the cells' capability to respond to the IL-7 growth signal, resulting in CTL failure and subsequent mishandling of the virus.

Virus-specific cytotoxic T lymphocytes (CTLs), which kill virus-infected cells, are thought to be a major host defense against viral infections. The addition of interleukin 7 (IL-7) at the onset of mitogen-stimulated cultures resulted in a marked (up to threefold) augmentation of env-specific cytotoxicity in human immunodeficiency virus type 1 (HIV-1)-infected individuals (p < 0.001). Addition of IL-7 on day 3 or 5 produced a significant but lesser augmentation of CTL response as compared to day 0. The IL-7-induced proliferative response and augmentation of cytotoxic activity was time and dose dependent, with an optimal IL-7 concentration of 1000 U/ml. Cell surface phenotypic analysis of CTL effector cells indicates that IL-7 primarily affects the proliferation of CD8+ T cells. Anti-IL-2 monoclonal antibody (MAb) substantially inhibited the proliferative effect of IL-2, but did not affect the proliferative effect of IL-7. Endogenous IL-2-induced generation of cytotoxic T cells was blocked by MAbs to IL-2 or IL-2R. The addition of IL-7 restored the process of conversion of precursor CTLs (pCTLs) to mature CTLs (mCTLs) and significantly enhanced specific cytolytic activity. It appears that IL-7 is a potent regulatory cytokine capable of acting independently of IL-2 in mitogen-specific activation of pCTLs to mCTLs. These data suggest that IL-7 should be considered as a potential therapeutic approach in AIDS and other infectious diseases in which CTL response declines.

The low-affinity Fc receptor for IgE, CD23/Fc epsilon RII, has been expressed in T cell lines and pathologic T cells, but its presence on normal human T cells is still debated. We studied the expression of CD23/Fc epsilon RII on purified T cells from normal peripheral blood mononuclear cells (PBMC) or tonsil T cells stimulated with 10 micrograms/ml phytohemagglutinin A (PHA) or phorbol-12myristate- 13acetate (PMA) Ca2+. Using two-dimensional flow cytometry, the tonsil T-cell-enriched population showed > 10% of CD23/Fc epsilon RII expression when coexpressed with the CD3 antigen. CD4+ T cells appear to be principally involved in the expression of CD23/Fc epsilon RII, although we were unable to detect a clear expression of CD23/Fc epsilon RII in PBMC that were activated with either PHA or PMA Ca2+. PHA stimulation resulted in the release of IgE binding factor (IgEBF). The induction of CD23/Fc epsilon RII expression in PHA- and PMA-Ca(2+)-activated T cells was enhanced by IL-4, but not by IgE or IL-6. IL-4 also augmented the PHA- and PMA-Ca(2+)-induced release of IgEBF. The addition of supernatant from the Epstein-Barr virus (EBV)-infected cell line to PHA- or PMA-Ca(2+)-stimulated tonsil T cells did not increase CD23/Fc epsilon RII expression. The expression of CD23/Fc epsilon RII mRNA was detected in RNA prepared from a tonsil T-cell-enriched population by Northern blot analysis.

Individuals infected with human immunodeficiency virus type 1 (HIV-1) develop a humoral immune response to the virus's major structural gene products env, gag, and pol. The distribution of antibodies to env, gag, and pol proteins in Central African populations is of interest as they have a high level of immune system activation compared to non-African populations. Using the Western blot technique, we analyzed the isotypic distribution of anti-HIV antibodies in 45 HIV-1-infected individuals from Central Africa that were either symptomatic or asymptomatic. We observed two basic differences between the isotypic profile of individuals from Central Africa and non-African populations. Central African individuals had a strong polyisotypic response to gag and pol, which has only been observed for gag in American and European populations. In addition, individuals from Central Africa had a high frequency of IgG4 to gag and pol, 75 and 51%, respectively, as compared to 29 and 6% in a non-African population. The elevated IgG4 response may result from the high basal level of immune stimulation seen in Africans due to multiple and frequent exposures to viral, bacterial, and parasitic antigens.

Phosphoinositidase C activity was revealed in nuclei isolated from PC12 rat pheochromocytoma cells incubated with tritiated phosphatidylinositol, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate. Phosphoinositide breakdown was found to be optimal at neutral pH and Ca++ concentrations ranging from endogenous levels to millimolar values. To characterize the enzymes involved, three monoclonal antibodies directed against the beta, gamma and delta phosphoinositidase C isoforms were employed. A combination of Western blot immunochemical analysis on cytoplasmic and nuclear fractions and of in situ immunocytochemistry on intact cells and isolated nuclei indicated that phosphoinositidase C gamma, though predominantly cytoplasmic, was present in both cell compartments. On the contrary, phosphoinositidase C beta was exclusively localized in the nucleus, whereas phosphoinositidase C delta was restricted to the cytoplasm. These data suggest that inositol lipid breakdown is controlled by different phosphoinositidase C isozymes in the various cell compartments, and support the notion that a separate phosphoinositide signalling system is located in the nucleus.

Protein phosphorylation catalysed by rat brain protein kinase C (PKC) has been studied in nuclei isolated from normal and regenerating rat liver. Histone H1 and a 40,000 molecular weight protein were hyperphosphorylated at all the explored regeneration times, ranging from 3 to 22 h after partial hepatectomy. Phosphorylation of the two substrates was totally dependent on calcium and lipids and was abolished by low concentration of staurosporine. The observed early change of phosphate content of histone H1 and of the 40,000 molecular weight protein on the time scale of liver regeneration suggests that PKC might be involved in the initial nuclear events leading to cell proliferation.

Significantly increased levels of IgG anti-IgE were seen in atopic patients as compared with controls. A correlation was observed between the levels of anti-IgE autoantibodies and serum IgE in the groups of atopic patients studied. No significant correlation was found between IgG anti-IgE levels and severity of the disease or between IgG subclasses with anti-IgE activity and clinical status. Analysis of IgG subclasses with anti-IgE activity showed that IgG1 and IgG4 were clearly factors in differentiating the atopics from the controls. IgG2 and IgG3 anti-IgE levels were not statistically significantly elevated. The lack of these autoantibodies may be explained by the presence of immune complexes or the lack of specificity of the monoclonal antibodies used in this study. These observations have not yet determined whether these autoantibodies and the isotypic selection and restriction observed play a role in the dysregulation of the immune response and in the evolution towards atopy.

Peripheral blood mononuclear cells of patients allergic to honey bee venom were stimulated with denatured bee venom phospholipase A2, and the antigen-activated T cells were propagated for 4 days by human IL-2 in the presence or absence of recombinant human lipocortin I. Upon antigenic stimulation with the denatured phospholipase A2 and autologous monocytes or by cross-linking of CD3 by anti-CD3 antibody, the activated T cells, which had propagated by IL-2 alone, formed N-glycosylated IgE-binding factors and glycosylation enhancing factor (GEF), while those propagated in the presence of lipocortin formed unglycosylated IgE-binding factors and glycosylation inhibiting factor (GIF). The GEF and GIF formed by the antigen- or anti-CD3-stimulated T cells had affinity for bee venom phospholipase A2 and could be purified by using anti-lipomodulin Sepharose. In the mouse lymphocyte system, the major cell source of GIF is antigen-specific suppressor T cells, and the antigen-binding GIF from the cells suppressed the in vivo antibody response in an antigen (carrier)-specific manner. In view of the findings in the mouse system, the present results may provide an immunological maneuver to generate allergen-specific suppressor T cells, and to obtain allergen-specific suppressor factor from T cell populations in the peripheral blood of allergic patients.

An IgG type of antibody directed against IgE has been studied in serum from healthy and allergic individuals. The technique used is based on a solid phase paper radioimmunoassay in which the discs were sensitized with purified IgE myeloma. After incubation with patient's serum, 125I anti-human IgG was added. The anti-IgE antibodies were partially blocked by endogenous IgE, indicating the presence of IgE-containing immune complexes in the serum. Heating of serum at 56 degrees C disrupted the immune complexes, thereby increasing the detectable levels of IgG anti-IgE. Significantly raised levels of anti-IgE antibodies were found in patients suffering from atopic disorders in comparison with the controls.

Foods which provoked migraine in 9 patients with severe migraine refractory to drug therapy were identified. The patients were then given either sodium cromoglycate or placebo orally in a double-blind manner, with foods previously identified as provocants. Sodium cromoglycate exerted a protective effect, thus confirming that it can prevent a hypersensitivity mechanism as well as the symptoms of migraine. Immune complexes were not produced in those patients who were protected by sodium cromoglycate. These observations confirm that a food-allergic reaction is the cause of migraine in this group of patients.

A solid-phase radioimmunoassay for the measurement of immunoglobulins is described, which is simple to perform and possesses sensitivity down to 1 ng/ml. Using anti-light chain serum in the solid-phase, antibody of any class can be measured using suitable labelled antisera.

Two-thirds of severe migraineurs were allergic to certain foods, shown by dietary exclusion and subsequent challenge. Radioallergosorbent test confirmed the relevance of these foods. Oral sodium cromoglycate protected these patients from food challenges. The initial specific allergic reaction in the gut may result in increased mucosal permeability which allows food antigens, complexes, or mediators to be absorbed and cause symptoms.

Using an ultracentrifugation technique human immunosuppressive virus (HIV) (GP15 and GP41), anti-HIV (anti-GP15 and anti-GP41) immune complexes were detected in the sera of 3 (1 Acquired immune deficiency syndrome (AIDS), 1 AIDS related complex (ARC), 1 Lymphadenopathy syndrome (LAS] out of 6 patients studied. Evidence for presence of HIV immune complexes was provided by: 1) demonstration of GP15 anti-GP15 and GP41 anti-GP41 immune complexes at neutral pH (pH 7.2); and 2) presence of free HIV antigen and specific HIV antibodies after dissociation of immune complex-like material with acid buffer. Formation of specific immune complexes in the sera of AIDS and ARC patients may be responsible for failure to detect free HIV antibodies in some of these patients.

Ten patients are described who, in addition to other allergic symptoms, suffered from arthralgia. Dietary exclusion relieved the symptoms and specific food challenge reproduced them. IgG anti-IgE autoantibodies were high in patients with arthralgia in the serum and in the synovial fluid as compared with normals and the majority of patients with rheumatoid arthritis, traumatic arthralgia, and osteoarthritis used as controls. In three food-allergic patients IgG anti-IgE was detectable in a complexed form in the serum samples examined before and after food challenge. The finding of IgG anti-IgE autoantibody in a group of patients with allergic arthralgia is quite exciting. It raises the possibility of distinguishing a subgroup of arthralgic patients not having a classical rheumatoid arthritis, who may have a definable external exacerbating cause for their symptoms. A larger detailed survey is now in progress.

The behaviour of the immune system during liver damage caused by chronic hepatitis delta virus (HDV) infection was evaluated by assessing, in 16 patients with HBsAg+ chronic liver disease and HDV superinfection (15 HBeAg-, 1 HBeAg+), phytohaemagglutinin (PHA)-induced interleukin-2 synthesis and interleukin-2 receptor expression, PHA and staphylococcal enterotoxin B (SEB)-induced gamma-interferon synthesis and, in some cases, the presence of hepatitis B virus DNA (HBV-DNA) within peripheral blood mononuclear cells (PBMC). The results were compared to those obtained in 13 patients without HBV replication (i.e., serum HBV-DNA and liver HBcAg-negative), in 15 with HBV replication (i.e., serum HBV-DNA and/or liver HBcAg-positive) with chronic liver disease without HDV superinfection, and in 15 HBsAg-negative healthy control subjects. The lymphokine pattern in HDV infection was comparable to that of healthy subjects and of HBV non-replicating patients without HDV superinfection. Interleukin-2 receptor expression and gamma-interferon synthesis were however significantly decreased in HDV-negative patients with active HBV replication. HBV-DNA was detected in PBMC from 8 of 23 patients, without any correlation with the lymphokine pattern. Our results suggest that in HDV-related chronic liver disease, immune system alterations are unlikely. HDV superinfection does not affect the occurrence of HBV-DNA sequences within the leukocytes. HBV-DNA in PBMC does not interfere with the interleukin-2 system nor with the gamma-interferon response in HBV- and HDV-related chronic liver disease.

Antigen entry and the formation of immune complexes occur in atopic subjects after food ingestion. We have studied patients with asthma, eczema and arthralgia and we were able to detect the presence of IgE immune complexes and the antigen entry from the gut before and after food challenge. Food allergic subjects showed, after food challenge, the presence of IgE and IgG immune complexes, which correlates with the subsequent occurrence of symptoms. Both the symptoms and the appearance of IgE immune complexes could be prevented by pretreatment with oral sodium cromoglycate (SCG). IgE immune complexes were isolated by an isokinetic ultracentrifugation gradient and the components were analyzed for antigen-specific IgE and IgG as well as free antigen levels. The observation that SCG reduces antigen entry, the appearance of IgE immune complexes and the occurrence of symptoms point to the central role of IgE in the intestinal mucosa.

Inflammatory pseudotumor (P.I.) of the lung is a rare benign lesion histologically characterized by a variety of inflammatory and mesenchymal cells (plasma cells, lymphocytes and histiocytes). The etiology remains obscure. We report a case of P.I. occurred immediately after a thoracic trauma. The infectious etiology is suggested by the growth of an anaerobic microorganism (Bacteroides) in tissue culture.

An IgG type of antibody directed against IgE has been studied in serum from healthy and allergic individuals. The technique used is based on a solid phase paper radioimmunoassay in which the discs were sensitized with purified IgE myeloma. After incubation with patients' serum, human IgG labeled with iodine 125 was added. The anti-IgE antibodies were partially blocked by endogenous IgE in the serum and heating the serum samples at 56 degrees C disrupted the immune complexes (ie, IgG-aIgE:IgE), thereby increasing the detectable levels of IgG anti-IgE. The specificity of anti-IgE autoantibody was confirmed by both competitive inhibition and absorption experiments, using IgG, IgM, IgA, IgE, and rabbit anti-human IgG. Significantly raised levels of anti-IgE autoantibody were found in patients suffering from atopic disorders in comparison to the controls. These observations may suggest that the anti-IgE autoantibody could play a certain role in the modulation of IgE-mediated immune system and the pathogenesis of atopic diseases.

Specific IgE complexes and symptoms of asthma and eczema were produced in two allergic patients by oral challenge with food allergen. Both symptoms and IgE complexes could be prevented by pre-treatment with oral sodium cromoglycate. The IgE complexes can fix complement and may therefore provide the vehicle of the "late" responses seen in immediate hypersensitivity. The central role of gut sensitivity is emphasised by the protection afforded by sodium cromoglycate both when given acutely, against the effects of an oral challenge, and when given continuously for asthma and eczema due to food allergy.

We have studied patients with the diagnoses of asthma, eczema, and arthralgia by monitoring the formation of immune complexes containing IgE after antigen egress from the gut before and after challenge with food. Following challenge, immune complexes containing IgE, IgG, and antigen are detectable in the circulation. Their appearance correlates with the production of symptoms. The effect of sodium cromoglycate was to prevent the appearance of complexes. This was associated with absence of symptoms. It is suggested that a local IgE-mediated mechanism acts as a "trigger" for the entry of antigen and the formation of immune complexes by altering the permeability of the gut mucosa. The resulting delayed onset symptoms could be viewed as a form of serum sickness with few or many target organs affected.