Histamine in pericarditis of children with congenital heart malformations

Introduction

Congenital heart malformations are risk factors that make children susceptible to infections resulting in inflammation.

Material and methods

The concentration of histamine as a modulator of inflammation was quantified in pericardial fluid and expression of histamine H₄ receptor (H₄R) and histamine-releasing factor (HRF) was determined at mRNA and protein levels. Samples of pericardium and pericardial fluid were obtained during cardiac reconstruction surgery in children.

Results

In children with pericarditis, increased levels of histamine were found and expression of H₄R was localized on mast cells. Expression of HRF was independent of presence or absence of inflammation in pericardium and was localized within stationary epithelial cells.

Conclusion

Results indicate that involvement of H4R in pericardial inflammation depends on penetration of mast cells into inflamed tissue, but HRF may not be directly involved in inflammatory reaction of the pericardium.

     

Histamine regulates murine primary dendritic cell functions

Objective and design: The modulation of antigen uptake and activation of dendritic cells (DCs) by histamine may function as a regulator of inflammation. Therefore, we sought to determine the impact of histamine on antigen uptake by and activation of murine DCs.

Material and methods: DCs from spleen and lung were either identified by flow cytometry or were immunomagnetically enriched. Cells were stimulated with histamine, and the regulation of MHC-II and co-stimulatory molecule expression (CD80, CD86, and ICOS-L) and antigen uptake were quantified by flow cytometry. Individual contributions of the histamine receptor subtypes were determined by using the antagonists mepyramine (histamine H₁-receptor: H₁R), famotidine (H₂R), and JNJ 7777120 (H₄R).

Results: Histamine accelerated the uptake of soluble antigen via the H₁R, H₂R, and H₄R in splenic DCs. Co-stimulatory molecule expression was enhanced already by enrichment procedures, thus, the analyses were performed in unseparated cell populations. Histamine enhanced the expression of CD86 and ICOS-L while expression of CD80 was unaffected. Antagonism at H₁R, H₂R, and H₄R and at H₁R and H₄R reduced the histamine-induced enhanced expression of CD86 and ICOS-L, respectively.

Conclusions: Histamine contributes to the regulation of the immunological synapse by stimulation of antigen uptake and activation of DCs via H₁R, H₂R, and H₄R.     

Das Aktionspotential des isolierten Ranvierschen Schnürrings bei Erhöhung der extracellulären Wasserstoffionen-Konzentration in calciumhaltigen und calciumarmen Lösungen

Summary 1. Effects of raising extracellular hydrogen-ion-concentration [H⁺] _e on the action potential (AP) of isolated nodes of Ranvier in calcium-containing (1.08 mMol/l) and in calciumpoor (0.05 mMol/l) solutions were studied between ph 7 and 4.8.2. Threshold membrane potential (i.e. maximum subthreshold response) and membrane potential at the end of the slow first falling phase increase with increasing [H⁺] _e , especially below ph 6.5. The amplitude of the AP is slightly raised.3. Mild lowering of ph from 7 to 6.5 in Ca-containing solutions accelerates repolarization, mainly during the slow first phase. In Ca-poor solution, small drop in ph reverses the effects of Ca-lack.4. Below ph 6.5 to 6.0, repolarization is delayed, mainly during the slow first phase and, to a smaller extent, during the negative after-potential. At low ph the AP becomes insensitive to lack of extracellular calcium.5. Between ph 7 and 6.5 H⁺-ions are suggested mainly to act in an indirect way by raising Ca-activity in or at the membrane, thus accelerating the decrease of P _Na or the increase in P _K. From the effects at lower ph-values it is concluded that in this range H⁺-ions act directly on the membrane; they would delay and decrease the change of P _K during the AP.

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Mit 5 Textabbildungen

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft. Die Ergebnisse wurden im Auszug auf dem Kongreß der Deutschen Physiologischen Gesellschaft, Zürich 1961, und auf dem Internationalen Kongreß für Biophysik, Stockholm 1961, vorgetragen.     

Antihistaminic drugs modify casein-induced inflammation in the rat

Introduction

All known antihistaminics may affect several inflammatory events, including chemotaxis, the survival of eosinophils, and the release of chemokines and cytokines from different sources, thus highlighting the potential for modulating chronic inflammation and immune responses. The aim of the study was to examine the effect of H₁–H₄ antihistaminic drugs in an acute model of casein-induced inflammation in rat.

Materials and methods

Inflammation was induced by injection of a 12% solution of casein into the peritoneal cavity of male Wistar rats. The rats were treated intraperitoneally with pyrilamine maleate (10 mg/kg), cimetidine (25 mg/kg), thioperamide maleate (2 mg/kg) or ciproxifan hydrogen maleate (0.14 mg/kg) twice: 2 hours prior and 4 hours after casein administration. The level of histamine in blood and chemiluminescence of stimulated and unstimulated PMNs was measured.

Results

The level of histamine in the casein-induced inflammation group was higher than in the control group. Treatment with pyrilamine and ciproxifan additionally increased the level of blood histamine during the inflammatory response. Peripheral blood neutrophils from rats with casein-induced inflammation tended to respond less to zymosan stimulation than the neutrophils in the controls. Selective H₁ and H₃ antagonists injected into the rats with casein-induced inflammation significantly increased the response of the neutrophils to zymosan (p < 0.01).

Conclusion

Histamine produced or released into the blood in the course of experimental inflammation exerts its effects on the PMN-s via stimulation of H₁ and H₃ receptors.

     

Decrease in expression of histamine H2 receptors by human amniotic epithelial cells during differentiation into pancreatic beta-like cells

Objective and design

Considering the role of histaminergic pathway in the differentiation of stem cells, we compared expression patterns of H₁ and H₂ receptors in the human amniotic epithelial cells (HAEC) culture at different stages of nicotinamide-induced differentiation into PBLC with the control HAEC.

Material and methods

HAEC isolated after term pregnancies (N = 12) were cultured in vitro. Altogether, 72 cultures were established. The culture medium in the studied group was supplemented on Day 5 with nicotinamide (10 mM). C-peptide concentration in the medium collected every 3 days for 15 days was determined immunoenzymatically as a marker of differentiation. At the same intervals the cultures were formalin-fixed and paraffinembedded for H₁ and H₂ receptors immunostaining. Quantitative immunohistochemistry was applied for evaluation of H₁ and H₂ expression.

Results

C-peptide was detected on Day 6 and the levels were kept gradually increased until Day 12, then stayed at almost the same level, 3.7-fold higher than initially. Expression of H₂ was unchanged until Day 9 after nicotinamide addition, then was significantly (p < 0.05) decreased and amounted (mean % value for the measurements performed on Day 12 and Day 15, ±SEM) 49.73 ± 11.03 of the reference value obtained in control HAEC.

Conclusion

Variable expression of H₂ during nicotinamide-induced differentiation of HAEC into PBLC may define a time-point, indicating involvement of histamine at the earlier stages.

     

Allergen challenge-induced changes in bone-marrow responses to leukotriene D4, nonsteroidal anti-inflammatory drugs and cytokines

Abstract

Context: In nonallergic (naive) mice, type I cysteinyl-leukotriene receptors (CysLT₁R) mediate the stimulatory effects of cytokines (eotaxin/CCL11, interleukin[IL]???13), and nonsteroidal anti-inflammatory drugs (NSAID; indomethacin, aspirin) on eosinophil production by IL-5-stimulated bone-marrow. In ovalbumin (OVA)-sensitized mice, airway challenge-induced bone-marrow eosinophilia and eosinopoiesis are prevented by pretreatment with blockers of adrenal glucocorticoid signaling (RU486, metyrapone) or cysteinyl-leukotriene (CysLT) signaling (montelukast).

Objective: To define whether allergen challenge modifies subsequent bone-marrow responses to CysLT, NSAID, and cytokines which act through type 1 CysLT receptor (CysLT₁R).

Methods: We examined the effects of sensitization/challenge, and of in vivo blockade of endogenous glucocorticoid or CysLT signaling, on ex vivo responses to CysLT1R-dependent stimuli.

Results and discussion: Challenge abolished the stimulatory ex vivo responses to CysLT₁R-dependent agents in the eosinophil lineage. In cultured bone-marrow of naive, sensitized and sensitized/challenged mice, responses to leukotriene D₄ (LTD₄) in eosinophil differentiation ex vivo shifted from stimulatory (without challenge) to suppressive (following challenge). Both stimulatory and suppressive LTD₄ effects were blocked by montelukast. The suppressive LTD₄ effect was accounted for by accelerated maturation followed by apoptosis of eosinophils. RU486/metyrapone or montelukast pretreatments before challenge prevented the challenge-induced change in subsequent responses to all these agents. Hence, allergen challenge has two separate effects on bone-marrow: (a) it enhances eosinopoiesis in vivo and upregulates ex vivo responses to IL-5; (b) it promotes a faster, but self-limiting, response to LTD₄ and CysLT1R-dependent stimuli.

Conclusion: Allergen challenge modifies eosinopoiesis through systemic (glucocorticoid- and CysLT1R-dependent) mechanisms, increasing responses to IL-5 but restricting responses to subsequent CysLT1R stimulation.     

Aqua cycling for immunological recovery after intensive,eccentric exercise

Purpose

Alterations in immunological homeostasis induced by acute exercise have been frequently reported. In view of the growing amount of repetitive exercise stimuli in competitive sports, quick recovery plays a superior role. Therefore, we examined whether aqua cycling affects cellular immunological recovery.

Methods

After performing 300 countermovement jumps with maximal effort male sport students (n = 20; 24.4 ± 2.2 years) were randomized into either an aqua cycling (AC) or a passive recovery (P) group. AC pedaled in chest-deep water without resistance, while P lay in a supine position. Each recovery protocols lasted 30 min. Blood samples were taken at Baseline, Post-exercise, Post-recovery and 1 h (h), 2 h, 4 h, 24 h, 48 h and 72 h after recovery. Outcomes comprised white blood cell (WBC) counts, lymphocyte (LYM) counts and LYM subsets (CD4/CD8 ratio). Additionally, cellular inflammation markers (neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and systemic immune-inflammation index (SII)) were calculated.

Results

In both groups, WBC, NLR and SII were significantly increased compared to Baseline up to and including 4 h after recovery. Significant interaction effects were found for WBC (Post-recovery, 2 h and 4 h), NLR (Post-recovery), SII (Post-recovery) and CD4/CD8 ratio (2 h) with values of AC being higher than of P.

Conclusions

Interestingly, AC provoked a stronger but not prolonged immunological disturbance than P. NLR and SII may present simple, more integrative markers to screen exercise-induced alterations in immune homeostasis/recovery in athletes and clinical populations. More research is warranted to elucidate the clinical and practical relevance of these findings.

     

Involvement of histamine and histamine H2 receptors in nicotinamide-induced differentiation of human amniotic epithelial cells into insulin-producing cells

Objective and design

Human amniotic epithelial cells (HAEC) resemble stem cells in their ability to differentiate into all three germ layers: endoderm, mesoderm, and ectoderm. Histamine receptors are expressed on HAEC. We examined the influence of histamine, and H₁ and H₂ antagonists on the generation of pancreatic islet beta-like cells from HAEC.

Materials and methods

HAEC were isolated after term pregnancies (N = 12) and cultured for 14 days with nicotinamide (10 mM) in normoxia. Altogether, 72 cultures were established. Histamine (100 μM) effects were investigated with mepyramine (10 μM) or cimetidine (10 μM). After 7 and 14 days, the mean concentration of C-peptide (MCCP) in the culture medium was measured immunoenzymatically as a marker of pancreatic differentiation.

Results

MCCP was approximately threefold higher on day 14, compared to day 7. Histamine significantly increased MCCP, and more evident differences were observed after 7 days of culture than after 14 days. The mean percent increase ±SEM in MCCP amounted to 142.19 ± 21.7 and 79.03 ± 12.35 compared to the controls on day 7 and 14, respectively. H₂ blockade significantly reduced histamine-related increase in MCCP, both on day 7 and 14 by 88.7 ± 14.3 and 39.2 ± 12.4%, respectively. H₁ receptor antagonist did not affect MCPP.

Conclusion

Nicotinamide-induced pancreatic differentiation of HAEC into beta-like cells may be augmented, probably at its earlier stage, by histamine acting via H₂ receptors.

     

Ketamine delays progression of oxidative and damaged cataract through regulating HMGB-1/NF-κB in lens epithelial cells

Objective: Lens epithelial cell (LEC) membrane damage is one of the pathogenesis of cataract. High mobility group box-1 (HMGB-1) and nuclear factor-κB (NF-κB) play vital roles in a variety of diseases, such as inflammation. Ketamine has numerous pharmacological effects that can inhibit inflammation. However, its role in cataract rats LECs has not yet been elucidated.

Materials and methods: LECs were isolated from SD rats and cultured in vitro. The cells were randomly divided into three groups, including the control group, cataract model group induced by H₂O₂, and ketamine group treated by 10?mM ketamine under H₂O₂ environment. LECs proliferation was assessed by MTT assay. LECs apoptosis was evaluated by Caspase-3 activity detection. NF-κB mRNA and protein expressions were tested by real-time PCR and Western blot. HMGB-1 expressions in cells and supernatant were detected by real-time PCR and ELISA. TNF-α and IL-1β secretions were detected by ELISA.

Results: In H₂O₂ model group, the LECs proliferation was significantly inhibited, the caspase-3 activity significantly increased, HMGB-1 mRNA and secretion significantly enhanced, NF-κB mRNA and protein levels significantly elevated, compared to the Control group (p?2O₂ model group compared to the Control group (p?2O₂ model group (p?p?Conclusions: Ketamine delays the progression of oxidative and damaged cataract by regulating HMGB-1/NF-κB expression, inhibiting TNF-α, IL-1β, and apoptosis, and promoting cell proliferation.     

The evaluation of enteric-coated mycophenolate sodium in cardiac deceased donor liver transplant patients in China

Abstract

Objective: The management of liver receivers requires intense immunosuppression to prevent graft rejection. Mycophenolate mofetil (MMF) is a common immunosuppressant but frequently suffer dose reduction for gastrointestinal adverse reactions (GI). Hence, the enteric-coated mycophenolate sodium (EC-MPS) is introduced as a substitute for MMF to reduce GI. The study was designed to investigate the efficacy, safety and exposure equation of EC-MPS in liver transplant patients in China.

Methods: Ninety-two liver receivers who administered EC-MPS or MMF as a primary immunosuppressant were enrolled in this single-center study and divided into MMF group and EC-MPC group, respectively. Efficacy and safety of EC-MPS were compared with MMF. The MPA exposure was measured at time 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12?h after mean 4.5 days of EC-MPS treatment. An equation of limited time points for estimating serum MPA exposure of EC-MPS was established using multiple stepwise regression model.

Results: Data show an interpatient variation in MPA AUC, C_max and T_max. After a first dose of EC-MPS, the mean value of serum AUC_0-12?h was 20.68 mg/L (SD 8.94, range 8.1–46.3). C_max was 9.7 mg/L (SD 6.48, range 2.7–16.3); T_max was 1.90?h (SD 0.97, range 0.5–4). The best equation for estimating the AUC was 6.0 1 4?+?0.946C₂?+?0.606C₃?+?1.154C₄?+?2.479C₆?+?5.07C₁₂. Comparing with MMF, EC-MPS not only effectively maintained immunosuppression, but also had similar incidences of infection, renal dysfunction and hematological disorders. However, EC-MPS markedly improved GI, the incidence of GI was half of the MMF group.

Conclusion: This analysis presented that EC-MPS is an effective and safe immunosuppressant as similar as MMF. The conversion of MMF to EC-MPS could be administered.     

Interleukin-4 and Interleukin-4 Receptor Alpha Gene Polymorphisms in Recurrent Aphthous Stomatitis

ABSTRACT

Background: Recurrent aphthous stomatitis (RAS) is a common oral condition with a major impact on the quality of life. The condition is thought to be due to the overexpression of T helper-1(Th1)-related cytokines. Since interleukin-4 (IL-4) and its receptor (IL-4Rα) are antagonistic to Th-1 pathways, polymorphisms in their genes may also be involved in the pathogenesis of aphthous stomatitis.

Methods: Sixty-four patients diagnosed with minor RAS and 141 (age- and sex-matched) healthy controls were assessed for 3 single-nucleotide polymorphisms (SNPs) within the promoter region of the IL-4 gene (?1098G/T, ?590C/T, and ?33C/T), and 1 SNP in IL-4Rα gene (+1902 A/G).

Results: No significant differences were detected between the patient and the control group regarding IL-4 allele frequencies. However, the patient group demonstrated a higher frequency of IL-4 ?590 CC genotype and a lower rate of IL-4 ?590 TC genotype.

The TCT, GTT, GCT, and GTC haplotypes of the IL-4 gene (?1098, ?590, ?33) were significantly more frequent in the patients and the GCC, and TTT haplotypes were more common in healthy controls. No significant differences were found in IL-4Rα gene polymorphism between the 2 groups.

Conclusions: Certain polymorphisms of IL4 gene could predispose individuals to RAS.     

Association between Q192R paraoxonase 1 polymorphism and serumadipocyte-fatty acid binding protein (FABP4) levels in Mexican women

Aim: This study aimed to evaluate the genetic effects of PON1 Q192R polymorphism on serum FABP4 levels in Mexican women.

Methods: PON1 Q192R polymorphism was genotyped using a TaqMan allelic discrimination assay and serum FABP4 concentration was measured using an enzyme-linked immunosorbent assay.

Results: The distribution of genotype frequencies in the assessed women (PON1 Q192R polymorphism) was QQ?=?20%, QR?=?48% and RR?=?32%. Significantly higher serum FABP4 levels were found in women with genotype QR/RR (20.6?±?2.20?ng/mL), when compared with the levels found in the QQ group (12.8?±?1.70?ng/mL) (p?=?.004). After, the odds ratio (OR) was calculated by binomial logistic regression analysis and a significantly higher OR was found in the QR/RR group when compared with the QQ group (OR?=?3.45; 95% CI?=?1.80–16.50; p?Conclusion: The results support an association between 192R-allele of the PON1 polymorphism (Q192R) and increased serum FABP4 levels (suggested as an early biomarker of CVDs risk) in assessed Mexican women.     

Release of acetylcholine in the ventral striatum is influenced by histamine receptors

To investigate whether histamine receptor ligands influence thein vivo-release of acetylcholine in the ventral striatum, this brain region was superfused with histamine receptor agonists or antagonists through a push-pull cannula and drug effects on the release of acetylcholine were investigated.

Histamine, the H₁ receptor agonist 2-thiazolyl-ethylamine and the H₃ receptor antagonist thioperamide enhanced acetylcholine release, while the H₃ receptor agonist (R)-α-methylhistamine was ineffective. The results indicate that H₁ receptors and H₃ receptors modulate acetylcholine release.

The thioperamide-induced increase of acetylcholine release might be exerted via H₃-receptors located on cholinergic terminals. Alternatively, thioperamide might enhance acetylcholine release by incresing endogenous histamine release via H₃ autoreceptors.

It is concluded that, via stimulation of striatal H₁- and H₃ receptors, histaminergic neurons are involved in the regulation of cholinergic neuronal activity in the ventral striatum.

     

Regulation of interleukin 2 (IL2) receptor expression: IL 2 as an inducing signal for the expression of its own receptor on a murine T helper cell line

The interleukin 2 receptor (IL2R) expression of a terpolymer of L-Glu⁶⁰, L-Ala³⁰, L- Tyr¹⁰ (GAT)-specific T helper (T_h) cell line, L14, was studied using two different rat monoclonal antibodies specific for the murine IL2R, 7D4 and 5A_2-2. L14 T cells expressed IL2R transiently, but contrary to the general assumption that IL2R expression is maintained only by periodic antigen stimulation, we observed that IL2 itself was able to regulate the level of IL2R on L14 T_h lymphocytes. In particular, it was found that L14 T cells, which had not been recently stimulated and which expressed a very low level of high affinity IL2R, could be induced to exhibit a high level of this receptor after exposure to recombinant IL2, in the absence of any specific signal. In contrast, the T_h cell line 52.3 used as control could be induced to express high levels of IL2R only after exposure to GAT; nevertheless, IL2 seems to play a critical role in the in vitro survival of the resting state of 52.3 T cells.     

Pharmacokinetics of Nevirapine: Once-Daily Versus Twice-Daily Dosing in the 2NN Study

Abstract

Objective: As part of the large international, randomized 2NN trial, the pharmacokinetics of nevirapine in once-daily 400 mg and twice-daily 200 mg dosing regimens were investigated. Method: Treatment-naive HIV-1-infected patients were randomized to receive nevirapine 400 mg once daily or 200 mg twice daily, in combination with lamivudine and stavudine. Blood samples were collected at several time-points (day 3, weeks 1, 2, 4, 24, and 48). Differences in pharmacokinetics between once- versus twice-daily dosing were investigated with nonlinear mixed effects modelling (NONMEM). Results: In total, 2,899 nevirapine plasma concentrations were available from 578 patients. Dosage and dosing frequency did not influence clearance or volume of distribution of nevirapine, indicating linear pharmacokinetic behavior of nevirapine whether given as a single daily dose or as divided doses over 24 hours. During steady state, the C_min was lower (3.26 mg/L vs. 4.44 mg/L; p < .001) and the C_max was higher (7.88 mg/L vs. 6.55 mg/L; p < .001) in the once-daily arm. However, compared to total variability in nevirapine levels for both treatments, these differences were minor. During steady state, total exposure, measured as AUC_24h, was comparable for both regimens (133 mg/L*h vs. 133 mg/L*h; p = .084). Conclusion: The daily exposure to nevirapine (AUC_24h) was similar for the 400 mg once-daily and the 200 mg twice-daily dosing regimens. The C_min of nevirapine is lower and the C_max of nevirapine is higher for the once-daily regimen as compared to the twice-daily regimen. As a result, 200 mg nevirapine dosed twice daily may be preferred over 400 mg nevirapine dosed once daily.     

A New Series of Conjugated Platinum‐co‐Poly(p‐phenylenebutadiynylene)s Polymers: Syntheses and Photophysical Properties

An efficient route is developed to synthesize a series of platinum‐co‐poly(p‐phenylenebutadiynylene)s (Pt‐co‐PPBs) polymers by stoichiometric mixing of poly(p‐phenylenebutadiynylene)s (PPBs) and platinum bis‐phosphine dichlorides. This synthetic route involves two steps; first, oxidative coupling of diterminal phenyleneethynylenes (PEs) gives low‐molecular‐weight PPBs oligomers H? C?C? (Ph(OR)₂ ? C?C? C?C)_n ? Ph(OR)₂ ? C?CH (R = C₄H₉ 1 , R = C₈H₁₇ 2 , R = C₁₂H₂₅ 3 ) (M_n = 1000–3000, degrees of polymerization, P_n(M_n) = 4–6 ), which have bifunctional alkynyl end groups, and in the second step, these organic oligomers are allowed to react with trans‐[(PⁿBu₃)₂PtCl₂] to form newly designed Pt‐co‐PPBs (R = C₄H₉ 4 , R = C₈H₁₇ 5 , R = C₁₂H₂₅ 6 ) polymers. The yield of 4–6 varies from good (63%) to high (76%) with high molecular weights (M_n) ranging from 52 738 to 74 212, and this methodology tolerates different alkoxy substituted PPBs. These new organometallic polymers contain platinum to phenylenebutadiynylene (PB) ratio of 1:4 to 1:6 and are solution processable. Polymer 4 displays fluorescence at room temperature and fluorescence and phosphorescence at low temperature in thin film, which would be useful for studying the triplet emission in these polymers.     

Strukturelle Effekte in Systemen MnLi/Butadien/Styrol

The structure of the butadiene unit C₄H₆ in the hydrolysis products of the oligomers RM_nC₄H₆M_m'Li and RM_nC₄H₆Li (where R is sec-butyl, M and M' are perdeuterobutadiene or styrene) was estimated by the use of IR- and NMR-spectroscopy. The dependency of the C₄H₆-structure on the nature of both the preceding unit M and the attacking monomer M' was investigated. The variation of the concentration of the organolithium compounds during the oligomer synthesis on the one hand, and during their hydrolysis on the other hand, showed a dependency of the C₄H₆-structure on the conditions of the respective experiments.     

Molecular analysis of rheumatoid factor (RF)-negative B cell hybridomas from rheumatoid synovial tissue: evidence for an antigen-induced stimulation with selection of high mutated IgVH and low mutated IgVL/λ genes

The mutational pattern of IgV_H and IgV_L genes from synovial tissue B cell hybridomas (n = 8) of patients (n = 4) with rheumatoid arthritis (RA) was analysed, which had been produced by the electrofusion technique without prior in vitro stimulation. The molecular data were correlated with immunohistopathological data and parameters of local disease activity. The IgV_H genes of the B cell hybridomas belonged to the V_H3 family (DP42; DP47, n = 2; DP53), the V_H1 family (DP75), the V_H4 family (DP71) and the V_H5 family (DP73); 7/7 IgV_H genes showed somatic mutations, the R/S ratio (CDR) was > 3 in 4/7 IgV_H genes and the mean R/S ratio of all IgV_H genes was 9.3 (CDR) and 1.0 (FR), suggesting an antigen-dependent selection. The IgV_L/λ genes belonged to the Vλ1 family (DPL2, DPL5, DPL8nf), the Vλ2 family (DPL11, n = 2) and to the Vλ6 family (IGLV6S1); 6/6 IgV_L genes showed somatic mutations, the R/S ratio (CDR) was > 3 in 3/6 IgV_L genes and the mean R/S ratio of all IgV_L was 3.0 (CDR) and 2.3 (FR), suggesting an antigen-dependent selection. The synovial tissue exhibited germinal centres in the follicles (3/4), with the unique distribution of Ki-M4⁺ follicular dendritic cells and Ki-67⁺ proliferating cells and a dominance of IgA⁺ plasma cells (3/3). All patients were positive for RF in serum and exhibited severe local symptoms (swelling 4/4; warmth 4/4; effusion 2/4), whereas the hybridomas were negative for RF. Since B cell hybridomas showed hypermutation and affinity selection for IgV_H and IgV_L/λ genes and the patients exhibited severe local symptoms with germinal centres in synovial tissue, this study indicates that an antigen-driven process is behind the B cell expansion in the synovial tissue of clinically affected joints. These mutated B hybridomas were negative for RF, thus suggesting that antigens different from RF are also involved in the local B cell expansion and in the chronic synovitis of RA.     

Prostaglandin E Receptor Subtypes EP2 and EP4 Promote TH1 Cell Differentiation and TH17 Cell Expansion Through Different Signaling Modules

It is well known that prostaglandin (PG) E₂ exerts T cell suppression in vitro through elevating cAMP by its receptors, EP2 and EP4. However, such an action is rarely detected in vivo, leaving PGE₂-mediated immunosuppression an enigma. Here we show that under strong TCR stimulation, PGE₂ facilitates T helper-1 (T_H-1) differentiation through activation of phosphatidylinositol-3-kinase (PI3K) by EP2 and EP4. The PGE₂-EP4 signaling is also required for IL-23 production by activated dendritic cells (DCs), and the PGE2-EP2/EP4 signaling amplifies IL-23-mediated T_H-17 cell expansion. Administration of an EP4-selective antagonist in vivo to mice subjected to experimental allergic encephalomyelitis (EAE) decreases accumulation of both T_H-1 and T_H-17 cells in regional lymph nodes, and suppresses the disease progression. These results suggest PGE₂ promotes immune inflammation through T_H-1 differentiation and T_H-17 expansion and the EP4 antagonism is therapeutically useful for various immune diseases.

     

Multiple Pathways Analysis of Brain Functional Networks from EEG Signals: An Application to Real Data

In the present study, we propose a theoretical graph procedure to investigate multiple pathways in brain functional networks. By taking into account all the possible paths consisting of h links between the nodes pairs of the network, we measured the global network redundancy R _h as the number of parallel paths and the global network permeability P _h as the probability to get connected. We used this procedure to investigate the structural and dynamical changes in the cortical networks estimated from a dataset of high-resolution EEG signals in a group of spinal cord injured (SCI) patients during the attempt of foot movement. In the light of a statistical contrast with a healthy population, the permeability index P _h of the SCI networks increased significantly (P < 0.01) in the Theta frequency band (3–6 Hz) for distances h ranging from 2 to 4. On the contrary, no significant differences were found between the two populations for the redundancy index R _h . The most significant changes in the brain functional network of SCI patients occurred mainly in the lower spectral contents. These changes were related to an improved propagation of communication between the closest cortical areas rather than to a different level of redundancy. This evidence strengthens the hypothesis of the need for a higher functional interaction among the closest ROIs as a mechanism to compensate the lack of feedback from the peripheral nerves to the sensomotor areas.