Rap1 Is Essential for B-Cell Locomotion, Germinal Center Formation and Normal B-1a Cell Population

Integrin regulation by Rap1 is indispensable for lymphocyte recirculation. In mice having B-cell-specific Rap1a/b double knockouts (DKO), the number of B cells in lymph nodes decreased to approximately 4% of that of control mice, and B cells were present in the spleen and blood. Upon the immunization with NP-CGG, DKO mice demonstrated the defective GC formation in the spleen, and the reduced NP-specific antibody production. In vitro, Rap1 deficiency impaired the movement of activated B cells along the gradients of chemoattractants known to be critical for their localization in the follicles. Furthermore, B-1a cells were almost completely absent in the peritoneal cavity, spleen and blood of adult DKO mice, and the number of B-cell progenitor/precursor (B-p) were reduced in neonatal and fetal livers. However, DKO B-ps normally proliferated, and differentiated into IgM+ cells in the presence of IL-7. CXCL12-dependent migration of B-ps on the VCAM-1 was severely impaired by Rap1 deficiency. Immunostaining study of fetal livers revealed defects in the co-localization of DKO B-ps and IL-7-producing stromal cells. This study proposes that the profound effects of Rap1-deficiency on humoral responses and B-1a cell generation may be due to or in part caused by impairments of the chemoattractant-dependent positioning and the contact with stromal cells.

Immune Complexes Impaired Glomerular Endothelial Cell Functions in Lupus Nephritis

Lupus nephritis (LN) is one of the most common and severe complications of lupus. However, the mechanisms for renal damage have not been well elucidated. There are evidences show that glomerular endothelial cells (GECs) are damaged in LN. Immune complexes can deposit in subendothelial area and could affect GEC functions. In the present study, we used heat-aggregated gamma globulin (HAGG) to simulate immune complexes and investigated their effects on GEC functions. Our results revealed that HAGG impaired different aspect of the GEC functions. HAGG changed cell morphology, upregulated the expression of active caspase-3, inhibited angiogenesis, and increased NO production in GECs. These results provide new clues for the mechanisms of renal damage and the pathology of LN.

Effect of glucocorticoid combined with gamma globulin in treatment of children with myasthenia gravis and its effects on immune globulin and complement of children

OBJECTIVE

To discuss the effects glucocorticoid combined with gamma globulins in the treatment of children with myasthenia gravis and its effects on immune globulin and complement of children.

PATIENTS AND METHODS

Clinical data of 70 cases of childhood myasthenia gravis in this hospital were retrospectively analyzed. These cases were randomly divided into observation group and control group. For observation group, there were methylprednisolone and gamma globulins while the only methylprednisolone in the control group. The clinical effects and changes in immune globulin and complement of two groups were observed.

RESULTS

The total effective rate for observation group was 94.3% and 74.3% for the control group, and this difference was statistically significant (p < 0.05) The time for relief of symptoms (6.55 ± 1.35 days) and total hospital stay (17.15 ± 3.65 days) in observation group was apparently shorter than the control group, with statistical significance (p < 0.05).

CONCLUSIONS

Glucocorticoid and gamma globulin can improve the symptoms and achieve satisfying clinical effects for the treatment of myasthenia gravis in children. Thus, it is valuable for further popularization and application.

[INHIBITION OF GROWTH OF BACTERIA IN STAPHYLOCOCCUS AUREUS AND PSEUDOMONASAERUGINOSA CULTURES BY COPPER AND ZINC CATIONS, APPLIED AT PHYSIOLOGICAL CONCENTRATIONS]

AIM

Evaluation of antibacterial effect,of γ-globulin fraction bound and free copper and zinc cations, applied in cultures-of S. aureus and P. aeruginosa at physiological (micromolar) concen- trations.

MATERIALS AND METHODS

Day cultures of S. aureus or P. aeruginosa were transferred from agar to physiological solution, and cell suspension was prepared, containing approximately 10 - 101 CFU/ml. Samples of metal-complexes of γ-globulin.with copper and zinc cations (30 and 45 μg/ml),. control γ-globulins (30 and 45 μg/ml) and salt solutions of copper and zinc, cation content in those corresponded to the quantity of the metal, that had bound with the protein at the stage of metal-complex obtaining (75 ng/ml), were introduced into the suspension. The suspensions were incubated at 37°C for 6 hours, sampling and CFU count according to the accepted micromethod was carried out every 2 hours. By the end of incubation (6 hours of observation) the suspensions were transferred into nutrient broth, thermostated for 1 day at 37°C, transparency of the nutrient broth compared with control (sterile) was evaluated afterwards.

RESULTS

Toxic effect of copper and zinc cations is detected starting from the 3rd hour of observation in S. aureus culture. Viable bacteria are absent in the culture with zinc after 6 hours, with copper - after 4 hours of incubation. γ-globulin, that had bound copper cations, reduces the quantity ofviable cells compared with control protein by 11.9 - 33.0% (p<0.05 - 0.1) at 4 and 6 hours of incubation. In P. aeruginosa culture, toxic effect of copper. cations manifests immediately after initiation of the culture and results in realization of complete bactericidal effect after 4.hours of observation. Zinc cations do not have such properties. γ-globulin, that had bound copper cations, reduces the quantity of viable cells compared with control protein at 4 and 6 hours ofincubationby 19.3- 25.8% (p<0.00 1).

CONCLUSION

S. aureus bacteria, supported in physiological solution are subject to toxic effect of physiological'(micromolar) concentrations of free copper and zinc cations, and also copper cations, bound by human serum γ-globulin. P. aeruginosa bacteria under the same conditions.experience toxic effect of copper cations (but not zinc), free as well as bound by human serum γ-globulin. Whereas a full bactericidal effect is realized in S. aureus and P. aeruginosa cultures in the-presence of free cations of copper.

Use of Gammaglobulin to Lower Elevated Natural Killer Cells in Patients with Recurrent Miscarriage

OBJECTIVE

To evaluate the effectiveness of intravenous immunoglobulin (IVIG) in patients presenting with recurrent miscarriage and abnormally elevated natural killer (NK) cells.

STUDY DESIGN

This retrospective patient controlled evidence level II-2 pilot study was conducted at Cohen Center, P.A., Medical City Dallas Hospital. Ninety women with a history of recurrent miscarriage (average, 5) and elevated NK cells were retrospectively evaluated to document the outcome of their treatment with IVIG.

RESULTS

Of 90 women with elevated NK cells who received IVIG treatment, 78 (86.7%) became pregnant. Sixty-four (82.0%) of those pregnancies had a successful viable outcome. Fourteen (18.0%) gestations ended as first trimester miscarriages.

CONCLUSION

We conclude at evidence level II-2 that, with adequate precautions, low-dose IVIG therapy is safe and effective for women with immunologic abortion and documented abnormally elevated NK cells.

Effects of hyaluronic acid and γ-globulin concentrations on the frictional response of human osteoarthritic articular cartilage

Synovial fluid plays an important role in lubricating synovial joints. Its main constituents are hyaluronic acid (HA) and γ-globulin, acting as boundary lubricants for articular cartilage. The aim of the study was to demonstrate the concentration-dependent effect of HA and γ-globulin on the boundary-lubricating ability of human osteoarthritis (OA) cartilage. Normal, early and advance stage articular cartilage samples were obtained from human femoral heads and in presence of either HA or γ-globulin, cartilage frictional coefficient (µ) was measured by atomic force microscopy (AFM). In advanced stage OA, the cartilage superficial layer was observed to be completely removed and the damaged cartilage surface showed a higher µ value (∼ 0.409) than the normal cartilage surface (∼ 0.119) in PBS. Adsorbed HA and γ-globulin molecules significantly improved the frictional behavior of advanced OA cartilage, while they were ineffective for normal and early OA cartilage. In advanced-stage OA, the concentration-dependent frictional response of articular cartilage was observed with γ-globulin, but not with HA. Our result suggested that HA and γ-globulin may play a significant role in improving frictional behavior of advanced OA cartilage. During early-stage OA, though HA and γ-globulin had no effect on improving frictional behavior of cartilage, however, they might contribute to disease modifying effects of synovial fluid as observed in clinical settings.

[Comparison of the effects of glutamate antibodies on neuronal activity of caspase 3 and memory impairment in rats induced by injection of Abeta(25-35) into the Meynert nuclei]

In experiments on rats showed that intranasal administration of glutamate antibodies in a dose of 300 microg/kg after 1 h after bilateral injection of neurotoxic fragment of beta-amyloid protein (25-35)--Abeta(25-35)--into the Meynert nuclei restores learning ability in the test of passive avoidance on 3 and 14 days of the experiment. Antibodies to glutamate decrease significantly increasing caspase 3 activity, detected on Day 3 after injection of Abeta(25-35), in samples of the prefrontal cortex and hippocampus but not hypothalamus. Intranasal administration of gamma-globulin had no effect on the performance of violations of mnestic functions and caspase 3 activity.

Effect of protein concentrations of bovine serum albumin and γ-globulin on the frictional response of a cobalt-chromium femoral head

The study aims to identify the concentration-dependent role of bovine serum albumin (BSA) and γ-globulin in the lubricating ability of a cobalt-chromium femoral head. The frictional coefficients of the cobalt-chromium femoral head decreased with increasing BSA concentrations from 10 to 40 mg/ml and showed statistical differences between any of the BSA concentration groups, except between the 30 and 40 mg/ml concentration groups. In γ-globulin, the frictional coefficients significantly decreased at concentrations of 2.5 and 5.0 mg/ml as compared with the PBS control group, but significant increases were observed at 7.5 and 12.5 mg/ml. These results suggest that the friction of the cobalt-chromium femoral head is dependent on the concentration of both BSA and γ-globulin. However, there is a maximum concentration for BSA to act as an effective boundary lubricant, while the lubricating ability of γ-globulin is most effective in the physiological concentration range within human synovial fluid.

Soluble immune complexes shift the TLR-induced cytokine production of distinct polarized human macrophage subsets towards IL-10

BACKGROUND

Costimulation of murine macrophages with immune complexes (ICs) and TLR ligands leads to alternative activation. Studies on human myeloid cells, however, indicate that ICs induce an increased pro-inflammatory cytokine production. This study aimed to clarify the effect of ICs on the pro- versus anti-inflammatory profile of human polarized macrophages.

MATERIALS AND METHODS

Monocytes isolated from peripheral blood of healthy donors were polarized for four days with IFN-γ, IL-4, IL-10, GM-CSF, M-CSF, or LPS, in the presence or absence of heat aggregated gamma-globulins (HAGGs). Phenotypic polarization markers were measured by flow cytometry. Polarized macrophages were stimulated with HAGGs or immobilized IgG alone or in combination with TLR ligands. TNF, IL-6, IL-10, IL-12, and IL-23 were measured by Luminex and/or RT-qPCR.

RESULTS

HAGGs did not modulate the phenotypic polarization and the cytokine production of macrophages. However, HAGGs significantly altered the TLR-induced cytokine production of all polarized macrophage subsets, with the exception of MΦ(IL-4). In particular, HAGGs consistently enhanced the TLR-induced IL-10 production in both classically and alternatively polarized macrophages (M1 and M2). The effect of HAGGs on TNF and IL-6 production was less pronounced and depended on the polarization status, while IL-23p19 and IL-12p35 expression was not affected. In contrast with HAGGs, immobilized IgG induced a strong upregulation of not only IL-10, but also TNF and IL-6.

CONCLUSION

HAGGs alone do not alter the phenotype and cytokine production of in vitro polarized human macrophages. In combination with TLR-ligands, however, HAGGs but not immobilized IgG shift the cytokine production of distinct macrophage subsets toward IL-10.

Management and outcome of intravenous gammaglobulin-resistant Kawasaki disease

INTRODUCTION

This study aimed to determine the prevalence and risk of intravenous gammaglobulin (IVIG)-resistant Kawasaki disease (KD) and report the outcome of treatment in patients with persistent or recurrent fever.

METHODS

70 KD patients, who received IVIG treatment (2 g/kg) at a tertiary care hospital from January 1995 to June 2004, were retrospectively reviewed.

RESULTS

Nine (13 percent) of the 70 patients failed to respond to initial treatment with IVIG. The patients who did not respond to IVIG had higher erythrocyte sedimentation rate (ESR) (104 versus 74 mm/h; p-value is 0.003), longer total days of fever (14.4 +/- 3.8 versus 9.2 +/- 2.3 days; p-value is 0.003) and higher initial coronary artery lesions (CAL) (7 of 9 [77.7 percent] versus 10 of 61 [16.3 percent]; p-value is 0.001) than those who responded to initial treatment. Seven of the nine patients who were retreated with IVIG (2 g/kg) responded to the second dose. The remaining two patients (two of nine, 22 percent) had persistent fever, which subsided after two to three doses of pulse intravenous methylprednisolone. At two months follow-up, IVIG-resistant patients had higher CAL by echocardiogram than IVIG-responsive patients (33 percent versus 3.2 percent, p-value is less than 0.05). Two IVIG-resistant KD patients had delayed diagnosis and developed giant aneurysms.

CONCLUSION

Patients with high ESR had increased risk of IVIG-resistant KD. IVIG-resistant Kawasaki patients had a higher prevalence of CAL at the acute phase and two months after onset.

[Preparation of placental-eluted gamma globulin and its immunosuppressive effect in vitro and in vivo]

The aim of this study was to establish a simple, convenient and efficient method of producing placental-eluted gamma globulin (PEGG) from human placenta, explore its inhibitory effect on the function of T lymphocyte in vitro and graft-versus-host disease (GVHD) in vivo. PEGG was prepared by elution at acid pH from human placental tissues that were extensively washed. Its effects on T lymphocyte proliferation induced by PHA and mixed lymphocyte reaction (MLR) were analysed by BrdU ELISA, its effect on the CD25 and CD69 expression on T cells was observed by flow cytometry, and the interferon gamma (IFN-gamma) and interleukin-4 (IL-4) quantification in MLR supernatant were assayed by ELISA. A murine GVHD model was established, the effect of PEGG on the manifestation and pathologic change of GVHD and 45-day survival rate were observed. The results showed that considerable level of immunoglobulin could be eluted from placenta at acid PH, of which the main components were IgG checked by SDS-PAGE analysis. In vitro study indicated that PEGG significantly inhibited both the proliferative response of T cells to PHA and the MLR, down-regulated the expression of CD25 and CD69 on T cells stimulated by PHA, and decreased the secretion of IFN-gamma but increased the production of IL-4 in MLR supernatant. In vivo, recipient mice treated with PEGG had a markedly increased survival rate with less histopathological evidence of GVHD. It is concluded that PEGG can inhibit the proliferation and activation of T cells, regulate the direction of T helper cells differentiating towards Th2 type, and effectively prevent GVHD in a murine model. In short, PEGG may be a potent therapeutic agent for GVHD.

Physicochemical and Pharmacokinetic Characterization of Highly Potent Recombinant l-Methionine γ-Lyase Conjugated with Polyethylene Glycol as an Antitumor Agent

A highly potent recombinant L-methionine gamma-lyase (METase) conjugated with polyethylene glycol (PEG) was characterized physicochemically and pharmacokinetically in vivo and in vitro. Pegylated METase (PEG-METase), which contains pyridoxal 5'-phosphate (PLP) as a cofactor in the molecule, is a potent anticancer agent that can deplete L-methionine from plasma. Although pegylation decreased its specific activity, dithiothreitol (DTT) treatment increased it over three times with the detachment of one PEG moiety modified with a cysteine residue. We can produce DTT-treated PEG-METase on a large scale in sufficient quality for therapeutic use. The superiority of DTT-treated PEG-METase was confirmed by the enhancement of L-methionine depletion and amelioration of pharmacokinetics in mice. The holoenzyme of DTT-treated PEG-METase gave a several times larger area under the plasma concentration curve than that of DTT-untreated PEG-METase, not because of an increase of the half-life but because of high specific activity. Conversely, simultaneous PLP infusion led to a greatly increased half-life of the holoenzyme. DTT-treated PEG-METase administration with PLP infusion was the most useful combination for maximizing the potency of the enzyme. We showed that serum albumin interfered with holoenzyme activity in vitro. The decrease of holoenzyme activity was dependent on the type of serum albumin. We concluded that PLP was released from PEG-METase by serum albumin in vivo and in vitro. The deleterious effect of PLP dissociation from PEG-METase could be improved by supplementing PLP and oleic acid. Their synergistic effect in preventing a decrease of the holoenzyme activity was also observed.

gamma-Globulin-induced modulation with necrotic-like morphology of peripheral blood neutrophils

To determine the effect of intravenous immunoglobulin-administration on neutrophil function, we obtained neutrophils from patients with an acute phase of Kawasaki disease. In vitro IgG-induced modulation of neutrophils into Annexin-V-positive and propidium iodide-negative cells was observed in 20 of 28 patients in the presence of more than 300 microg/ml IgG and showed necrosis-like changes in morphologic features. However, we could not find any patients showing promotion of the sub-G1 cell fraction on DNA content analysis. The modulatory effect of in vitro IgG was not observed in neutrophils from healthy volunteers and was significantly correlated with the antifebrile effect of in vivo IgG.

Immune complex-stimulated production of interleukin-12 in peripheral blood mononuclear cells is regulated by the complement system

Immune complexes (IC) can induce cytokine production in vitro. While immune aggregates (IA) consisting of heat-aggregated gamma globulin (HAGG) as model IC increased interleukin (IL)-10 levels in cell cultures with native human serum, IL-12p40/p70 production was inhibited. Three series of experiments suggested that the effects of IA on IL-12 production depended on a functionally intact complement system: (1) heat-inactivation of serum inverted the inhibitory effect of IA on IL-12p40/p70 production; (2) IA-induced IL-12p40 production in a C4 deficient serum was lowered by addition of C4; and (3) addition of the peptide compstatin, which blocks C3 activation, mimicked the effects of heat inactivation on IL-12p40 levels. Neutralization of IL-12 resulted in modestly increased IL-10 levels, while neutralization of IL-10 had no effects on IL-12p40 production. IA-induced production of IL-10 was partially blocked by anti-Fcgamma RII antibodies, whereas Fcgamma R or CR blockade had no effect on IL-12p40 production. IC and local or systemic complement activation characterize rheumatoid arthritis, systemic lupus erythematosus and many malignancies. Different and complement-dependent effects on the production of IL-10 and IL-12 can be of importance in these diseases, where control of the complement system might be a way to direct IC-induced cytokine production in either a type 1 or type 2 direction.

Adjuvant treatment for complement activation increases the effectiveness of photodynamic therapy of solid tumors

Phototoxic lesions generated in tumor tissue by photodynamic therapy (PDT) are recognized by the host as a threat to the integrity and homeostasis at the affected site. Among the canonical pathways invoked by the host for dealing with this type of challenge is the activation of the complement system, integrating proteins that serve as molecular sensors of danger signals produced by PDT and those initiating signalling cascades coupled into the network of inflammatory and immune responses. Since the activated complement system is a salient participant of the antitumor response produced by PDT, it is worth exploring whether its manipulation can be exploited for the therapeutic benefit. Using mouse tumor models, the present study examined the potential of representative complement-activating agents to act as effective adjuvants to PDT. Tumor-localized treatment with zymosan, an alternative complement pathway activator, reduced the recurrence-rate of PDT-treated tumors, markedly increasing the percentage of permanent cures. In contrast, a similar treatment with heat aggregated gamma globulin (complement activator via the classical pathway) was of no significant benefit as a PDT adjuvant. Systemic complement activation with streptokinase treatment had no detectable effect on complement deposition at the tumor site without PDT, but it augmented the extent of complement activity in PDT-treated tumors. This finding based on immunohistochemistry analysis explains the results of tumor therapy experiments, which showed that systemic treatment with streptokinase or a similar agent, urokinase, enhances the PDT-mediated tumor response. Zymosan and streptokinase administrations produced no beneficial results with PDT of tumors growing in complement-deficient mice. This study, therefore, establishes the potential of complement-activating agents to serve as effective adjuvants to PDT for cancer treatment.

Long-term study of antibody response and injection-site effects of oil adjuvants in Atlantic halibut (Hippoglossus hippoglossus L)

Atlantic halibut were injected intraperitoneally with human gamma globulin suspended in either phosphate buffered saline, Freunds complete adjuvant or Montanide ISA711 to test the long-term effects of adjuvants. Every month for 12 months up to five animals from each group were sampled. The peritoneal cavity was examined and the adhesion level scored on an arbitrary scale. Serum was also collected and analysed by ELISA for antibodies to human gamma globulin. Results show that whilst FCA produced the highest and fastest antibody response, it also produced the fastest intraperitoneal adhesions, persisting through 11 months. However, the adhesions were not very severe and did not appear to affect the halibut. Crown

F(ab)'2-mediated neutralization of C3a and C5a anaphylatoxins: a novel effector function of immunoglobulins

High-dose intravenous immunoglobulin (IVIG) prevents immune damage by scavenging complement fragments C3b and C4b. We tested the hypothesis that exogenous immunoglobulin molecules also bind anaphylatoxins C3a and C5a, thereby neutralizing their pro-inflammatory effects. Single-cell calcium measurements in HMC-1 human mast cells showed that a rise in intracellular calcium caused by C3a and C5a was inhibited in a concentration-dependent manner by IVIG, F(ab)2-IVIG and irrelevant human monoclonal antibody. C3a- and C5a-induced thromboxane (TXB2) generation and histamine release from HMC-1 cells and whole-blood basophils were also suppressed by exogenous immunoglobulins. In a mouse model of asthma, immunoglobulin treatment reduced cellular migration to the lung. Lethal C5a-mediated circulatory collapse in pigs was prevented by pretreatment with F(ab)2-IVIG. Molecular modeling, surface plasmon resonance (SPR) and western blot analyses suggested a physical association between anaphylatoxins and the constant region of F(ab)2. This binding could interfere with the role of C3a and C5a in inflammation.

Interaction of serum proteins with CYP isoforms in human liver microsomes: inhibitory effects of human and bovine albumin, alpha-globulins, alpha-1-acid glycoproteins and gamma-globulins on CYP2C19 and CYP2D6

The effects of serum proteins on the in vitro hydroxylation pathways of mephenytoin (CYP2C19) and debrisoquine (CYP2D6) were studied to enhance the predictability of in vivo drug metabolism from in vitro assays. Both CYP substrates are known to be weakly bound to albumin and the applicability of the free drug hypothesis was further appraised. Since bovine serum albumin (BSA) is used widely in in vitro assays, a comparison between human and bovine proteins was made. Four major serum proteins were studied: albumin, alpha1-acid glycoprotein (AGP), alpha- and gamma-globulins. Human serum albumin (HSA) inhibited both CYP activities about 20% more than BSA. The addition of human alpha-globulins, but not the bovine protein, resulted in marked reduction of 86% and 41% in CYP2C19 and CYP2D6 activities, respectively. This reduction of activity was strikingly greater than the fraction bound (14 and 22%, respectively). The inhibition was of the competitive type and the Ki values of human alpha-globulins on CYP2C19 and CYP2D6 were found to be 0.45% (4.5 mg/ml) and 3.5% (35 mg/ml), respectively. The effect of both human and bovine gamma-globulins on CYP isoforms was negligible. The Ki values of human and bovine AGP for CYP2C19 were 1.84% (420 microM) and 0.93% (210 microM), respectively. For HSA, human alpha-globulins and human and bovine AGP, the strongly decreased CYP activities in vitro cannot be explained by the free drug hypothesis. A direct interaction of these serum proteins with CYP enzymes is postulated. Differential effects of bovine and human serum proteins and CYP specific inhibition were observed.

Pooled human gammaglobulin modulates surface molecule expression and induces apoptosis in human B cells

We have previously shown that the pooled human gammaglobulin (IVIG) inhibited mixed lymphocyte reaction (MLR). In this study, we examined (1) if IVIG contains blocking antibodies reactive with cell surface molecules required for alloantigen recognition and (2) if IVIG modulates these surface molecule expressions using flow cytometry. IVIG does not contain significant amounts of blocking antibodies against CD3, CD4, CD8, CD20, CD14, CD40, MHC class I and class II. It reduces the number of intact B cells and monocytes, reduces or modulates CD19, CD20 and CD40 expression on B cells, and induces morphological changes in B cells. This B-cell modulation results primarily because of apoptosis. IVIG also induces apoptosis in T cells and monocytes, but to a lesser degree. Induction of apoptosis requires the intact IgG molecule. Reduction of intact B cell and monocyte cell numbers, modulation of surface molecule expression on B cells, and deletion of B and T cells by apoptosis could result in inhibition of optimal T-cell activation. This likely represents the primary mechanism responsible for IVIG suppression of the MLR, and may account for many of the observed beneficial effects of IVIG seen in the treatment of human autoimmune and alloimmune disorders.

[Successful treatment of Echovirus 27 meningoencephalitis in agammaglobulinaemia with intraventricular injection of gammaglobulin. A case report]

BACKGROUND

Meningoencephalitis due to enteroviruses is particularly serious when occurring in patients with agammaglobulinaemia. This disease is associated with a high mortality and a significant risk for neurological sequelae in such circumstances. We report here a new case treated with intraventricular immunoglobulin, whose evolution was favourable.

CASE REPORT

A three-year-old boy with agammaglobulinaemia, while he was treated with gammaglobulin with an IgG residual concentration of 10 g/l, presented neurological symptoms related to Echovirus 27 meningo encephalitis. Under treatment with intraventricular gammaglobulin by means of an Ommaya reservoir, the patient recovered.

CONCLUSION

Favourable evolution is rare in meningo encephalitis in agammaglobulinaemic patients. Prognosis depends on an early diagnosis and on the extent of dissemination of the infection. Intraventricular gammaglobulin administration may contribute to a favourable outcome.

Impaired endothelial function in the brachial artery after Kawasaki disease and the effects of intravenous administration of vitamin C

BACKGROUND

Previous studies in patients with a history of Kawasaki disease have focused on vascular endothelial function in coronary arteries, and the endothelial function of systemic arteries is not fully understood. Furthermore the effect of vitamin C on systemic endothelial function after Kawasaki disease has not been elucidated.

OBJECTIVES

We attempted to analyze endothelium-dependent vasodilatation in the brachial artery after Kawasaki disease by using high resolution ultrasonography and to investigate whether the acute administration of vitamin C could restore such systemic endothelial dysfunction.

METHODS

We compared 39 patients (7.1 +/- 2.7 years) 1.0 to 9.6 years after acute Kawasaki disease with 17 matched healthy subjects (7.0 +/- 3.1 years) as controls. Using high resolution vascular ultrasound, we measured brachial artery responses to reactive hyperemia (with increased flow causing endothelium-dependent dilatation) and sublingual nitroglycerin (causing endothelium-independent dilatation).

RESULTS

The percent change in diameter of the brachial artery induced by reactive hyperemia in the patients with a history of Kawasaki disease (6.2 +/- 3.9%) was significantly lower than that in the control group (14.1 +/- 6.8%; P < 0.0001). No significant difference could be found in percent change in diameter induced by sublingual administration of nitroglycerin between the control (33.2 +/- 13.7%) and the patients with a history of Kawasaki disease (30.6 +/- 9.2%; P = 0.49). There was no significant difference in percent change in diameter of the brachial artery induced by reactive hyperemia between the patients who received gamma-globulin (6.0 +/- 4.0%) and those who did not receive gamma-globulin (7.9 +/- 3.3%; P = 0.33). Intravenous infusion of vitamin C significantly increased the percent change in diameter of brachial artery induced by reactive hyperemia in 19 patients with history of Kawasaki disease (6.6 +/- 3.5 to 13.0 +/- 5.5%; P < 0.0001), whereas no significant increase was seen in the percent change in diameter of brachial artery induced by reactive hyperemia in 20 patients with history of Kawasaki disease after placebo administration (6.5 +/- 4.5 to 7.3 +/- 4.9%; P = 0.20).

CONCLUSIONS

Our study showed decreased percent change in diameter of the brachial artery induced by reactive hyperemia in patients with history of Kawasaki disease compared with the healthy children, indicating that systemic endothelial dysfunction exits after Kawasaki disease. Although such systemic endothelial dysfunction after Kawasaki disease is not influenced by early treatment with high dose gamma-globulin in the acute stage of Kawasaki disease, it can be restored by the acute intravenous administration of vitamin C.

The interaction of human and bovine serum proteins with CYP3A in human liver microsomes: inhibition of testosterone 6beta-hydroxylation by albumin, alpha-globulins, alpha(1)-acid glycoprotein and gamma-globulins

The effects of human and bovine serum proteins on CYP3A activity, using testosterone as the probe substrate, were investigated in human liver microsomes. Serum albumin, alpha-globulins, and alpha(1)-acid glycoprotein (alpha(1)-AGP) of both species significantly inhibited testosterone 6beta-hydroxylation. When the inhibitory effects of serum proteins were compared with serum protein binding data, human alpha-globulins, with a ratio (relative metabolic activity/unbound fraction) of 0.3, showed higher, and bovine alpha(1)-AGP, with the ratio of 1.4, showed lower inhibitory effects than those expected from protein binding of testosterone. The effects of the other serum proteins were close to those expected from protein binding, according to the free drug hypothesis. The K(i) values obtained from the Dixon plots were 0.32% (w/v, 48 microM) for human serum albumin (HSA), 0.48% for human alpha-globulins, and 0.23% (52 microM) for human alpha(1)-AGP. K(i) values of bovine serum albumin, bovine alpha-globulins and bovine alpha(1)-AGP were 3-5 times higher than those of the respective human proteins. The results suggest a direct interaction of some of these serum proteins with the active site of the CYP3A isoform. Since the bovine serum proteins showed weaker inhibitory effects than human serum proteins, the wide use of BSA, which is viewed as interchangeable with HSA, needs to be cautioned.

Correction of the nonlinear dose response improves the viability of adenoviral vectors for gene therapy of Fabry disease

Systemic administration of recombinant adenoviral vectors for gene therapy of chronic diseases such as Fabry disease can be limited by dose-dependent toxicity. Because administration of a high dose of Ad2/CMVHI-alpha gal encoding human alpha-galactosidase A results in expression of supraphysiological levels of the enzyme, we sought to determine whether lower doses would suffice to correct the enzyme deficiency and lysosomal storage abnormality observed in Fabry mice. Reducing the dose of Ad2/CMVHI-alpha gal by 10-fold (from 10(11) to 10(10) particles/mouse) resulted in a greater than 200-fold loss in transgene expression. In Fabry mice, the reduced expression of alpha-galactosidase A, using the lower dose of Ad2/CMVHI-alpha gal, was associated with less than optimal clearance of the accumulated glycosphingolipid (GL-3) from the affected lysosomes. It was determined that this lack of linearity in dose response was not due to an inability to deliver the recombinant viral vectors to the liver but rather to sequestration, at least in part, of the viral vectors by the Kupffer cells. This lack of correlation between dose and expression levels could be obviated by supplementing the low dose of Ad2/CMVHI-alpha gal with an unrelated adenoviral vector or by depleting the Kupffer cells before administration of Ad2/CMVHI-alpha gal. Prior removal of the Kupffer cells, using clodronate liposomes, facilitated the use of a 100-fold lower dose of Ad2/CMVHI-alpha gal (10(9) particles/mouse) to effect the nearly complete clearance of GL-3 from the affected organs of Fabry mice. These results suggest that practical strategies that minimize the interaction between the recombinant adenoviral vectors and the reticuloendothelial system (RES) may improve the therapeutic window of this vector system. In this regard, we showed that pretreatment of mice with gamma globulins also resulted in significantly enhanced adenovirus-mediated transduction and expression of alpha-galactosidase A in the liver.

[Dynamic study of platelets surface glycoprotein in Kawasaki disease]

OBJECTIVE

To study the activation of platelets in children with Kawasaki disease (KD) at molecular level.

METHODS

The expression of platelet surface glycoproteins CD(41), CD(42a), CD(61), CD(62p) and CD(63) in 20 KD patients was measured by flow cytometry before and at 1, 2, 3 week after treatment with aspirin and high-dose (1 approximately 2 g/kg) intravenous gamma-globulin (IVIG).

RESULTS

The expression of glycoprotein CD(41), CD(42a), CD(61), CD(62p) and CD(63) were higher in KD group than in control group. Aspirin and IVIG could not inhibit these high expression of glycoproteins. Higher expression of CD(62p) was observed in patients with coronary artery injury.

CONCLUSION

Platelets were highly activated in KD patients which may be one of the most important pathophysiological step in KD. It provided a theoretical basis for treatment of KD with antagonist of glycoprotein of platelets. Obviously increase of CD(62p) can be taken as a criterion for predicting coronary artery injury in KD patients.

[Genoprotective human blood activity and its mechanisms]

Anticlastogenic properties of plasma and proteins (albumin and gamma-globulin) of the human blood were studied using seeds of Crepis capillaris (chromosome aberration assay). Antimutagen p-amino-benzoic acid was used as a comparative reagent. Anticlastogenic activity dependent of processing conditions of the biosubstrate used; for the pre-processing and combined processing anticlastogenic effect was higher than for post-processing, the processing properties of the blood being higher than those of the blood proteins. Anticlastogenic potential of biosubstrates did not depend on mutation inductor. Complex-formimg properties of plasma and blood albumen have been revealed using spectrop-hotometry through the substantial spectral displacement--relative to the expected spectrum--for the mixture of biosubstrata and mutagens. Using chemoluminescence, all plasma, albumin and gamma-globulin concentrations have been shown to enhance generation of hydroxyl radical of the Fenton reagent, especially for albumin in 1.0 g/l concentration. The general trend for all experiments was that the said substances diminished the stimulating effect as their concentrations grew. Peroxidation of yolk lipoproteids showed that only high concentrations of blood's plasma and albumen have antioxidizing properties. gamma-Globulin did not reveal any ability to inhibit lipid peroxidation of yolk lipoproteids. Complex-forming mechanisms of blood's albumen and antioxidizing property of human plasma and proteins have been proved to form the blood's anticlastogenic potential.

Endotoxin inactivation by enterally applied colostrum of different composition

BACKGROUND AND PURPOSE

Enteral applied bovine colostrum can significantly reduce endotoxin concentration in plasma. Since colostrum is a mixture of biological active ingredients 3 possible substances which are able to influence the endotoxin elimination were concentrated in 3 different colostrum products. Immunoglobulin-, lactoferrin- and casein-enriched colostra and lactoferrin alone were orally administered to endotoxinaemic rats.

METHODS

Endotoxinaemia was induced to rats by enteral application of 10(10) E. coli together with 40 mg Nebacetin. Control animals received albumin. From all rats plasma samples were taken over the time of 5 h and endotoxin concentration determined with limulus lysate and chromogenic substrate.

RESULTS

Whereas in control animals as well as in animals treated with casein-enriched colostrum a marked increase of endotoxin values to over 130 EU/dl could be observed after 5 h, the oral application of gammaglobulin-enriched and especially lactoferrin-enriched colostrum decreased endotoxin values by more than 50%. The most effective endotoxin elimination was seen with lactoferrin alone.

CONCLUSIONS

From this results it can be concluded that not only gammaglobulin but especially lactoferrin seems to be responsible for the elimination of endotoxin with regard to enterally applied colostrum preparations.

Fc gamma RIIB as a potential molecular target for intravenous gamma globulin therapy

The ability of the immune system to respond appropriately to foreign antigen is dependent on a delicate balance of activating and inhibitory signals. Recently, the role of cell surface inhibitory receptors in attenuating immune responses, thereby preventing pathologic conditions including autoimmunity and atopy, has been recognized. It is postulated that the beneficial effects of intravenous gamma globulin in the treatment of immune disorders may be attributable, at least in part, to engagement of Fc gamma RIIB, a member of the recently described family of immune inhibitory receptors. Recent genetic and biochemical studies have identified the SH2 domain-containing inositol 5-phosphatase (SHIP) as a critical effector in Fc gamma RIIB inhibitory signaling. This review summarizes recent work from our laboratory and others aimed to define the mechanism(s) by which Fc gamma RIIB and its effector, SHIP, inhibit immune responses. Elucidation of these mechanisms may lead to the development of therapeutic strategies for the treatment of autoimmune and inflammatory pathologies that specifically target Fc gamma RIIB or its effector(s).

The anti-allergic drug histaglobin inhibits NF-kappaB nuclear translocation and down-regulates proinflammatory cytokines

The transcription factor NF-kappaB is the central regulator for the expression of various genes involved in inflammation, infection and immune response including the genes for IL-1beta, TNF-alpha, IL-6 and leukocyte adhesion molecules. Here, we show that the anti-allergic drug histaglobin down-regulates the release of IL-1beta, TNF-alpha, IL-6 and IL-10 in human peripheral blood mononuclear cell cultures. This down-regulatory effect becomes even more pronounced when the cultures are simultaneously activated with the T-lymphocyte mitogen phytohemagglutinin (PHA) or with the B-lymphocyte and macrophage activator lipopeptide (P(3)CSK(4)). We also demonstrate that histaglobin inhibits the nuclear translocation of NF-kappaB in response to TNF-alpha or lipopolysaccharide (LPS) in bone marrow-derived macrophages of Balb/c mice. The inhibitory effect of histaglobin on NF-kappaB activation and cytokine release might be responsible for its anti-allergic effect as demonstrated in clinical studies.

Increased leukocyte aggregation induced by gamma-globulin: a clue to the presence of pseudoleukopenia

BACKGROUND

Previous articles have reported the appearance of leukopenia after the administration of high-dose intravenous gamma-globulins.

METHODS

A simple slide test was used to reveal the state of leukocyte aggregation (LA) in the peripheral blood as well as the absolute number of leukocytes in the slides.

RESULTS

A significant (P < 0.00001) increment was noted in the state of LA, from 9 +/- 6% before to 25 +/- 11% after gamma-globulin administration. This was accompanied by a significant (P < 0.0004) reduction in the number of white blood cells in the peripheral blood (from 8433 +/- 3905 to 6550 +/- 3252 cells/mm3) but no significant change in the absolute number of the cells as determined by the leukocyte count per high power field in the peripheral slides.

CONCLUSIONS

We raise the possibility that the leukopenia reported in some patients after the intravenous administration of high dose gamma-globulin is explained in part by the agglutination effect of the drug.

Class switch recombination and hypermutation require activation-induced cytidine deaminase (AID), a potential RNA editing enzyme

Induced overexpression of AID in CH12F3-2 B lymphoma cells augmented class switching from IgM to IgA without cytokine stimulation. AID deficiency caused a complete defect in class switching and showed a hyper-IgM phenotype with enlarged germinal centers containing strongly activated B cells before or after immunization. AID-/- spleen cells stimulated in vitro with LPS and cytokines failed to undergo class switch recombination although they expressed germline transcripts. Immunization of AID-/- chimera with 4-hydroxy-3-nitrophenylacetyl (NP) chicken gamma-globulin induced neither accumulation of mutations in the NP-specific variable region gene nor class switching. These results suggest that AID may be involved in regulation or catalysis of the DNA modification step of both class switching and somatic hypermutation.

Participation of neuropeptides in antigen-induced contraction of guinea pig bronchi via NK(2) but not NK(1) receptor stimulation

We evaluated the contribution of neuropeptides to antigen-induced contractions of isolated bronchi and tracheae of passively sensitized guinea pigs using CP-96345 and SR 48968, specific antagonists of NK(1) and NK(2) receptors, respectively, in combination with treatment by an antihistaminic and a cysteinyl leukotriene antagonist. SR-48968 but not CP-96345, significantly inhibited the late phase of the bronchial contraction. Phosphoramidon, a neutral endopeptidase inhibitor, tended to potentiate bronchial contraction. Posttreatment with SR-48968 decreased the enhanced contraction induced by the inhibitor as well as the nonenhanced contraction to similar levels of tension. On the other hand, antigen-induced tracheal contraction was not altered by either neuropeptide antagonist. These results suggest that neuropeptides mediate the antigen-induced contractile response of the guinea pig bronchus partly through NK(2) receptor stimulation.

Urocortin in the ventromedial hypothalamic nucleus acts as an inhibitor of feeding behavior in rats

Urocortin (UCN), a member of the corticotropin-releasing factor (CRF) family, inhibits food intake when it is injected intracerebroventricularly in rats. To explore the site of action of UCN in feeding behavior, we examined the effects of injection of UCN into various hypothalamic nuclei on food and water intake in 24-h fasted rats. Injection of UCN into the ventromedial hypothalamic nucleus (VMH) significantly inhibited food and water intake over 3 h without sedative effect, but no significant effect was observed following injection either into the lateral hypothalamic area, or the paraventricular nucleus of the hypothalamus. To further explore the physiological significance of endogenous UCN of the VMH in feeding behavior, the effect of immunoneutralization of hypothalamic UCN on food intake was examined. Injection of anti-rat UCN rabbit gamma-globulin into the bilateral VMH in freely fed rats significantly potentiated food and water intake compared with rats that received normal rabbit gamma-globulin. These results suggest that endogenous UCN in the VMH exert inhibitory control on ingestive behavior.

Characteristics of copper corrosion in simulated uterine fluid in the presence of protein

In order to acquire more knowledge of the performance of copper-bearing intrauterine devices (Cu-IUDs), corrosion behavior of copper in a simulated uterine fluid was investigated in the presence of proteins. The proteins studied included serum albumin, gamma-globulin and hemoglobin. Electrochemical polarization resistance measurements indicated that, in all cases under study, the corrosion rate of copper declined with time and the proteins always increased the rate. Moreover, different kinds of protein showed different dependence of copper corrosion rate on protein level. Addition of serum albumin initially raised the copper corrosion rate; however, the higher albumin concentration resulted in less promotion of the corrosion. X-ray diffraction (XRD) of the specimen surface showed that, both in the presence and absence of serum albumin, cuprous oxide was the only corrosion product, even though at higher concentrations of albumin less cuprous oxide was formed. This implies that serum albumin does not alter the corrosion mechanism. Electrochemical cathodic reduction of the oxide film and chemical analysis of solution after corrosion testing proved that the proportion of soluble ionic copper in the whole corrosion products varied with the albumin level. The copper corrosion rate in the presence of gamma-globulin or hemoglobin increased monotonically with increasing concentration of the protein. These three proteins shifted the corrosion potential of copper towards negative. It could be inferred that the proteins accelerated the anodic dissolution process of copper and hence enhanced its corrosion.

Effect of intravenous immunoglobulin therapy on plasma complement

The effect of the intravenous immunoglobulin preparation (Sandoglobulin) on the complement system and the formation of circulating immune complexes (CIC) was investigated in 10 patients with primary humoral immunodeficiency and in 12 normal volunteers. Infusion of 9 g of the pH4 treated preparation did not show relevant changes in total hemolytic complement activity, plasma levels of C4, C3, and factor B. C3dg fragments, however, increased markedly in some individuals in both groups immediately after infusion. CIC measured by 125 I-C1q binding were not detectable. Furthermore, the initially low C1q concentrations in immune-deficient patients correlated with the pre-infusion IgG levels (p < 0.05) and rose significantly 24 h after therapy (p < 0.001). In contrast, in vitro incubation of the immunoglobulin preparation with normal human serum did not reveal spontaneous anticomplementary activity nor did it lead to formation of immune aggregates. The results indicate that immunoglobulin infusions may moderately activate complement in vivo, as evidenced by increased C3dg fragments; in addition, partial C1q deficiency in hypogammoglobulinemia seems to be related to IgG concentration and can be corrected by immunoglobulin substitution.

Gamma globulin, Evan's blue, aprotinin A PLA2 inhibitor, tetracycline and antioxidants protect epithelial cells against damage induced by synergism among streptococcal hemolysins, oxidants and proteinases: relation to the prevention of post-streptococcal sequelae and septic shock

An in vitro model was employed to study the potential role of streptococcal extra-cellular products, rich in streptolysin O, in cellular injury as related to streptococcal infections and post-streptococcal sequelae. Extra-cellular products (EXPA) rich in streptolysin O were isolated from type 4, group A hemolytic streptococci grown in a chemostat, in a synthetic medium. EXPA induced moderate cytopathogenic changes in monkey kidney epithelial cells and in rat heart cells pre-labeled with 3H-arachidonate. However very strong toxic effects were induced when EXP was combined with oxidants (glucose oxides generated H2O2, AAPH-induced peroxyl radical (ROO.), NO generated by sodium nitroprusside) and proteinases (plasmin, trypsin). Cell killing was distinctly synergistic in nature. Cell damage induced by the multi-component cocktails was strongly inhibited either by micromolar amounts of gamma globulin, and Evan's blue which neutralized SLO activity, by tetracycline, trasylol (aprotinin), epsilon amino caproic acid and by soybean trypsin inhibitor, all proteinase inhibitors as well as by a non-penetrating PLA2 inhibitor A. The results suggest that fasciitis, myositis and sepsis resulting from infections with hemolytic streptococci might be caused by a coordinated 'cross-talk' among microbial, leukocyte and additional host-derived pro-inflammatory agents. Since attempts to prolong lives of septic patients by the exclusive administration of single antagonists invariably failed, it is proposed that the administration of 'cocktails' of putative inhibitors against major pro-inflammatory agonizes generated in inflammation and infection might protect against the deleterious effects caused by the biochemical and pharmacological cascades which are known to be activated in sepsis.

Hemopexin decreases spontaneous chemiluminescence of cold preserved liver after reperfusion

Hemopexin is a plasma protein with exceptionally high affinity for heme. During liver transplantation heme is released via lysis of transfused blood. This heme may catalyze peroxidative reactions that contribute to "reperfusion" injury of the organ. Using a rat liver model of cold storage and reperfusion we tested the potential anti-oxidant effects of hemopexin. After 3 h of cold storage rat liver was reperfused with warm oxygenated buffer. Spontaneous liver chemiluminescence, which is a parameter of oxyradical production, was measured during reperfusion and expressed as an index of free radical production (IFRP). Chemiluminescence reached a maximum within 5 min of reperfusion and decreased to baseline within 30 min. Addition of hemopexin to the perfusate (5 microM) significantly decreased the IFRP. By contrast, the control proteins albumin and gamma-globulin (10 microM) had a smaller non-significant effect. The data suggest that heme could be complexed by hemopexin during reperfusion, thus inhibiting heme mediated cellular injury.

[Immunoregulatory mechanisms of action of intravenous gammaglobulin in Kawasaki syndrome]

Kawasaki Syndrome (KS) is an acute vasculitis in young children associated with the development of coronary artery abnormalities. KS has been reported to occur in over 40 countries including Poland. The etiology of this disease remains controversial. However, recent studies suggest a potential role of bacterial toxins (superantigens) in the immunopathogenesis of KS. Immunomodulatory benefit and potential toxin neutralisation by intravenous immune globulin (IVIG) support the hypothesis of superantigen-related activation of the immune system in KS. The prevalence of cardiovascular abnormalities can be significantly reduced by treating patients during the first 10 days of illness with high-dose of intravenous gammaglobulin. The following predominant and non-exclusive mechanisms of action have been proposed to account for the immunomodulatory effects of IVIG in Kawasaki and other immune-mediated diseases: (i) functional blockade of Fc receptor on monocytes/macrophages; (ii) modulation of the production of cytokines and cytokine antagonists; (iii) inhibition of complement mediated damage; (iv) neutralisation of bacterial toxins by specific antibodies; (v) neutralisation of circulating autoantibodies by complementary (e.g. anti-idiotypic) antibodies in IVIG. These observations provide an important information that early recognition and prompt treatment of this illness is critical for a successful outcome.

A complex of histamine/mouse gamma-globulin preferentially inhibits allergen-induced peritoneal accumulation of eosinophils, but not neutrophils, in mice

A complex of histamine/human gamma-globulin (HhG) has been widely used in Japan for more than 25 years as a nonspecific hyposensitization drug in the treatment of allergic diseases. It has been reported that HhG decreases the number of eosinophils in the nasal secretions and peripheral blood of patients with allergy. In this study we used a mouse system to explore the possibility that HhG may actively inhibit the accumulation of eosinophils at inflammation sites. A complex of 0.15 microg of histamine dihydrochloride/12 mg of mouse gamma-globulin (HmG) was incubated for 2 hours in saline solution in the normal fashion for HhG. HmG at 50 to 150 mg/kg/day inhibited the peritoneal accumulation of eosinophils induced by ragweed pollen in BALB/c mice in a dose-dependent fashion when the HmG was administered subcutaneously six times during a 20-day sensitization period. The inhibitory effect of HmG on this eosinophil accumulation was significant at 24 and 48 hours after challenge, but HmG had no effect on neutrophil accumulation. Complexes of serotonin/mouse gamma-globulin (mgammaG), glutamine/mgammaG, and histamine dihydrochloride (His)/mouse albumin had no inhibitory effect when administered in the same way. The optimum combination ratio was between 0.15 microg of His/12 mg of mgammaG and 0.015 microg of His/12 mg of mgammaG for this eosinophil inhibition. Moreover, a 1- to 2-hour incubation period of His and mgammaG was needed to induce a plateau inhibition of the eosinophil accumulation. These results in mice suggest that HhG may actively inhibit allergen-induced eosinophil accumulation, which may be therapeutically useful in the treatment of allergic disease.

Brain beta-endorphin and other opioids are involved in restraint stress-induced stimulation of the hypothalamic-pituitary-adrenal axis, the sympathetic nervous system, and the adrenal medulla in the rat

Opiates and opioids have complex effects on the hypothalamic-pituitary-adrenal axis, and they stimulate the sympathetic nervous system. This study was designed to clarify the role of brain beta-endorphin in the mechanism by which stress increases plasma concentrations of adrenocorticotropin (ACTH), epinephrine (E), and norepinephrine (NE). Intracerebroventricular (i.c.v.) administration of beta-endorphin to rats significantly increased plasma ACTH levels at doses of 0.09, 0.3, and 1.5 nmol, and plasma E and NE levels at doses of 0.3 and 1.5 nmol. The rise of plasma ACTH, E, and NE levels by 0.3 nmol beta-endorphin was inhibited by intravenous (i.v.) administration of 2 mg/kg b.wt. naloxone. I.v. administration of anti-rat corticotropin-releasing hormone (CRH) rabbit serum completely blocked the beta-endorphin-induced ACTH secretion without affecting the secretion of E and NE. I.c.v. administration of anti-beta-endorphin rabbit gamma-globulin attenuated a 30-min restraint stress-induced rise of plasma ACTH levels without significant influence on the rise of E and NE levels, whereas i.v. administration of naloxone attenuated the restraint stress-induced rise of plasma ACTH, E and NE levels. These results suggest that i.c.v. administration of beta-endorphin stimulates the secretion of ACTH, E, and NE through opiate receptor, and that brain CRH mediates the beta-endorphin-induced secretion of ACTH. The results also suggest that brain beta-endorphin is, at least in part, involved in the restraint stress-induced stimulation of the hypothalamic-pituitary-adrenal axis, and that some opioids other than beta-endorphin are involved in the stimulatory mechanism of the autonomic nervous system and the adrenal medulla in the rat.

Blockade of brain 'ouabain' prevents the impairment of baroreflexes in rats after myocardial infarction

BACKGROUND

The purpose of this study was to test whether increased brain "ouabain" contributes to impairment of both arterial and cardiopulmonary baroreceptor reflexes in congestive heart failure (CHF).

METHODS AND RESULTS

Two to 5 days after coronary artery ligation (MI) or sham surgery in male Wistar rats, chronic intracerebroventricular (ICV) infusion was started with either antibody Fab fragments, which bind ouabain and related steroids with high affinity, or gamma-globulins as control (200 microg x 12 microL[-1] x d[-1] for both) with osmotic minipumps implanted subcutaneously. After 8 weeks of infusion, in conscious rats, mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), and renal sympathetic nerve activity (RSNA) were recorded at rest and in response to ramp changes in blood pressure (BP) induced by intravenous phenylephrine and nitroprusside and to changes in CVP elicited by acute volume expansion with 5% dextrose. Compared with sham rats, in MI rats with ICV gamma-globulins, resting MAP was significantly lower and CVP increased, and both arterial and cardiopulmonary baroreflex control of RSNA and HR were attenuated. ICV Fab fragments prevented the decrease in resting BP and largely prevented impairment of arterial and cardiopulmonary baroreflex control of both RSNA and HR.

CONCLUSIONS

These data indicate that increased brain ouabain plays a major role in the impairment of baroreflexes in rats with CHF after myocardial infarction.

The actions of polynucleotides on effector stage cloned murine T-helper cells differ in each subset and depend on antigen concentration

Polynucleotides enhance T-helper (Th) cell-mediated humoral immune responses in naive resting Th cells, B cells, and antigen-presenting cells (APC) from unprimed mouse spleen. If polynucleotides augment Th cell functions independent of the activation stage of Th cells, then polynucleotides may cause hyperimmune responses. In this study we examined the effects of polynucleotides on effector-stage murine Th cell clones in vitro. The A.E7 clone (primed with pigeon cytochrome C, origin: B10.A mice) and CDC35 clone (primed with rabbit gamma-globulin, origin: DBA/2 mice) were used as representative type 1 (Th1) and type 2 (Th2) Th cells, respectively. Th clones were stimulated with antigen (Ag) in polynucleotide-supplemented or control cultures in the presence of syngeneic spleen cells (either CD4- or irradiated). The number of antibody (Ab)-secreting cells was counted to measure T-dependent Ab production. Production of interferon-gamma (IFNgamma) for the Th1 clone and interleukin-5 (IL-5) for the Th2 clone were measured. Without Ag stimulation, cytokine production and the number of Ab-secreting cells formed were very low and not altered by polynucleotides. With suboptimal Ag challenges provided by Ag-primed spleen cells, polynucleotides enhanced IFNgamma production by the Th1 clone, while they suppressed Th1 clone-mediated Ab production and IL-5 production by the Th2 clone. Polynucleotides did not alter Th2 clone-mediated Ab production. These actions of polynucleotides appeared to be dose-dependent. With optimal Ag challenges, polynucleotides did not affect our measures of Th cell activation. Polynucleotide action in vitro on effector-stage Th cell clones differed in each Th cell subset and depended on Ag concentration.

Brain 'ouabain' in the median preoptic nucleus mediates sodium-sensitive hypertension in spontaneously hypertensive rats

Pressor responses to an acute increase in cerebrospinal fluid sodium and exaggeration of the hypertension and sympathetic hyperreactivity in spontaneously hypertensive rats (SHR) by high sodium diet involve release of brain "ouabain" and subsequent activation of the brain renin-angiotensin system. In the present study, we determined whether release of "ouabain" in the median preoptic nucleus participates in these responses. In conscious Wistar rats, the pressor and heart rate responses to central hypertonic saline (0.3 mol/L NaCl, 3.8 microL/min over 10 minutes) and ouabain (0.6 microgram) were compared after median preoptic nucleus injection of either gamma-globulins or Fab fragments binding ouabain and brain "ouabain" with high affinity. Microinjection of Fab fragments into the median preoptic nucleus abolished the pressor and tachycardic responses to central hypertonic saline and significantly reduced the pressor response to central ouabain. In SHR on high sodium, microinjection of Fab fragments into the median preoptic nucleus significantly decreased baseline blood pressure to a level not different from that in SHR on regular sodium (149 +/- 7 versus 145 +/- 5 mm Hg), whereas the enhanced responses to air stress were not affected. Our results support the concept that blood pressure responses to central hypertonic saline and exaggeration of the hypertension in SHR by high sodium diet depend on release of brain "ouabain" in the median preoptic nucleus.