Non-specific oral and cutaneous manifestations of Coronavirus Disease 2019 in children.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) seems to affect children only marginally, as a result, there is less knowledge of its manifestations in childhood. The purpose of this retrospective cross-sectional study was to investigate the oral and cutaneous manifestations in children affected by COVID-19. MATERIAL AND METHODS: All the medical records of children with COVID-19 admitted to the Pediatric Clinic- ASST Spedali Civili of Brescia from March to April 2020 were reviewed. The following data were recorded: age, temperature, clinical presentation, oral mucosa lesions, taste alteration and cutaneous lesions. RESULTS: The medical records of twenty-seven pediatric patients (mean age 4,2 years + 1,7) were analyzed. The clinical presentation of the disease mainly included elevated body temperature and cough. The following oral lesions were recorded: oral pseudomembranous candidiasis (7.4 %), geographic tongue (3.7%), coated tongue (7.4 %) and hyperaemic pharynx (37 %). Taste alteration was reported by 3 patients. Six patients presented cutaneous flat papular lesions. CONCLUSIONS: As for our paediatric sample, COVID-19 resulted to be associated with non-specific oral and cutaneous manifestations.

Phenotypic and genotypic characteristics of cryopyrin-associated periodic syndrome: a series of 136 patients from the Eurofever Registry.

OBJECTIVE: To evaluate genetic, demographic and clinical features in patients with cryopyrin-associated periodic syndrome (CAPS) from the Eurofever Registry, with a focus on genotype-phenotype correlations and predictive disease severity markers. METHODS: A web-based registry retrospectively collected data on patients with CAPS. Experts in the disease independently validated all cases. Patients carrying NLRP3 variants and germline-mutation-negative patients were included. RESULTS: 136 patients were analysed. The median age at disease onset was 9 months, and the median duration of follow-up was 15 years. Skin rash, musculoskeletal involvement and fever were the most prevalent features. Neurological involvement (including severe complications) was noted in 40% and 12% of the patients, respectively, with ophthalmological involvement in 71%, and neurosensory hearing loss in 42%. 133 patients carried a heterozygous, germline mutation, and 3 patients were mutation-negative (despite complete NLRP3 gene screening). Thirty-one different NLRP3 mutations were recorded; 7 accounted for 78% of the patients, whereas 24 rare variants were found in 27 cases. The latter were significantly associated with early disease onset, neurological complications (including severe complications) and severe musculoskeletal involvement. The T348M variant was associated with early disease onset, chronic course and hearing loss. Neurological involvement was less strongly associated with V198M, E311 K and A439 V alleles. Early onset was predictive of severe neurological complications and hearing loss. CONCLUSIONS: Patients carrying rare NLRP3 variants are at risk of severe CAPS; onset before the age of 6 months is associated with more severe neurological involvement and hearing loss. These findings may have an impact on treatment decisions.

Recurrent migratory angioedema as cutaneous manifestation in a familiar case of TRAPS: dramatic response to Anakinra.

BACKGROUND: Tumor Necrosis Factor Receptor Associated Periodic Syndrome (TRAPS) is a hereditary autoinflammatory syndrome characterized by recurrent episodes of fever and localized inflammation. Clinical presentation can be very variable in terms of duration of fever attacks, periodicity, and accompanying manifestations. One of the most characteristic symptoms is the occurrence of migrating skin rash with myalgia that is sustained by monocytic inflammation. OBSERVATIONS: We herein present the case of a family suffering from TRAPS who had been misdiagnosed for a long period of time and whose main symptom was migrating angioedema. Skin biopsy from one of the patients documented a monocytic panniculitis. All the living patients responded dramatically to anakinra treatment. CONCLUSIONS: The classic symptom of migratory angioedema with myalgia in TRAPS can be produced by monocytic panniculitis.This manifestation is so characteristic of TRAPS that its occurrence, even in the absence of other manifestations, should prompt genetic analysis. Our patient's condition responded promptly to anakinra treatment.

Dysregulation of the immune system in Aicardi-Goutières syndrome: another example in a TREX1-mutated patient.

Aicardi-Goutières syndrome (AGS) is a rare genetic encephalopathy characterized by neurological and extraneurological involvement. A clinical overlap between AGS and systemic lupus erythematosus (SLE) has been reported. We describe an AGS patient who developed autoimmune manifestations: thyroiditis, cANCA positivity, antiphospholipid antibodies and cerebral ischemia. This first description of antiphospholipid syndrome in a TREX1-mutated patient further expands the clinical spectrum of AGS. Although the clinical overlap with SLE may indicate common pathogenic mechanisms, the autoimmune manifestations in AGS are so extensive that we suggest they should be considered a clinical feature of the disease, rather than a sign of coexistent SLE.

IL-1ß induces GFAP expression in vitro and in vivo and protects neurons from traumatic injury-associated apoptosis in rat brain striatum via NFκB/Ca²âº-calmodulin/ERK mitogen-activated protein kinase signaling pathway.

Reactive astrogliosis, a feature of neuro-inflammation is induced by a number of endogenous mediators including cytokines. Despite interleukin-1 beta (IL-1ß) stands out as the major inducer of this process, the underlying mechanism and its role on neuronal viability remain elusive. We investigated in human astrocytoma cells and the rat brain striatum, the role of the nuclear factor-kB (NF-kB) intracellular Ca(2+) concentration ([Ca(2+)]i) calmodulin (CaM) and extracellular regulated mitogen-activated protein kinases (ERK1/2) in IL-1ß-induced expression of glial fibrillary acidic protein (GFAP) and neuronal apoptosis associated to a brain trauma. Cell data showed that IL-1ß (1 ng/ml) increased NF-kB, pERK1/2 and GFAP expression. Nevertheless, further increase in IL-1ß levels reversed progressively these responses. Preventing ERK1/2 activation with 1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthiol]-butadiene antagonized IL-1ß-induced GFAP expression while inhibiting selectively nuclear translocation of NF-kB with caffeic-acid phenethyl-ester down-regulated both ERK1/2 and GFAP expression induced by IL-1ß. The GFAP response was also prevented by antagonizing selectively increase in [Ca(2+)]i, CaM activity or inducible nitric oxide synthase expression with respectively ryanodine plus 2-aminoethoxydiphenyl-borate, N-(6-aminohexyl)-5-chloro-1-naphthalensulfonamide hydrochloride and N-[(3-(aminomethyl)-phenyl]methyl]-ethanimidamide dihydrochloride. Data in vivo supported these findings and showed that GFAP expression induced by IL-1ß (50 ng/ml) correlated with attenuated glial scar formation and reduced neuronal apoptosis. Our data identified the NF-kB/Ca(2+)-CaM/ERK signaling pathway as a novel in vivo key regulator of IL-1ß-induced astrogliosis which may represent a potential target in neurodegeneration.

Aicardi-Goutieres syndrome, a rare neurological disease in children: a new autoimmune disorder?

Aicardi-Goutieres syndrome (AGS), described by J. Aicardi and F. Goutieres in 1984, is a rare neurological disease with onset in infancy. It is often misdiagnosed as a sequela of congenital infection or recognized later. Nowadays almost 200 cases are reported all over the world, most of them collected by the International Aicardi-Goutieres Syndrome Association (IAGSA), founded in Pavia (Italy) in 2000. AGS (MIM 225750) is a genetically-determined encephalopathy characterized by severe neurological dysfunction, acquired microcephaly associated with severe prognosis quoad valetudinem, and less frequently also quoad vitam. Some AGS children also develop some symptoms overlapping with systemic lupus erythematosus (SLE). Intracranial calcification, white matter involvement and brain atrophy revealed on MRI, lymphocytosis and elevated levels of interferon alpha (IFN-α) in the cerebrospinal fluid (CSF) are features of both AGS and congenital viral infection. No evidence of congenital infection at serological exams has ever been found. A genetic etiology was hypothesized since the first descriptions, because of the recurrence in families, and demonstrated some years ago. Nowadays five genes (AGS1-5), if mutated, can be responsible for 90% of the cases. The transmission is autosomal recessive but there are also rare "de novo" autosomal dominant cases. Even if pathogenesis is still almost unknown, it seems that responsible genes are involved in nucleic acid reparation mechanisms and consequently in a secondary activation of innate autoimmunity. The relative lack of precise information on pathogenesis and on the evolution of the disease over time has not yet allowed the creation of codified diagnostic and therapeutic models and programs.

[Fine specificity of anti-ß2glycoprotein I antibodies in systemic autoimmune diseases is mostly directed against domain 1]. / La fine specificità degli anticorpi anti-ß2 glicoproteina I nelle malattie autoimmune sistemiche è prevalentemente diretta verso il dominio 1.

OBJECTIVE: Anti-ß2 GPI are a formal laboratory criterion for the antiphospholipid syndrome (APS). They were demonstrated to be a risk factor for thrombosis and fetal losses but can also be detected in patients with systemic autoimmune disease (SAD), in healthy adults individuals and pre-school children. It has been suggested that different subpopulations of anti-ß2GPI may carry different pathogenetic potential: autoantibodies against Domain1 seem to be associated with thrombosis; autoantibodies against Domain4/5 have been identified in patients with non-thrombotic conditions. METHODS: We studied 48 patients with SAD (32 systemic lupus erythematosus, 16 undifferentiated connettive tissue disease), 64 patients with APS, 57 one-year-old healthy children born to mother with SAD, 33 children with atopic dermatitis. All subjects were IgG anti-ß2 GPI positive. The specificity of anti-ß2 GPI was investigated using ELISA research products containing recombinant ß2 GPI D1 and D4/5 antigens. Cut-off values are calculated as 95th percentile on 100 NHD. IgG anti-ß2 GPI were tested at a validated home-made ELISA routinely performed in our laboratory. No thrombotic events were recordered in patients with SAD and in both groups of children. RESULTS: Patients with SAD and APS showed prevalent reactivity for D1 while children in both groups preferentially recognize D4/5. CONCLUSIONS: IgG anti-ß2 GPI against D1 seem to cluster in patients with systemic autoimmune conditions. Their pathogenic potential in determine APS manifestations may be mitigated by adequate prophylaxis.

Long-term clinical profile of children with the low-penetrance R92Q mutation of the TNFRSF1A gene.

OBJECTIVE: To analyze the long-term impact of the R92Q mutation of TNFRSF1A in children with periodic fever, in comparison with children with tumor necrosis factor receptor-associated periodic syndrome (TRAPS) with TNFRSF1A structural mutations and children with periodic fever of unknown origin fulfilling the criteria for periodic fever, aphthosis, pharyngitis, and adenitis syndrome (PFAPA). METHODS: The extracellular region of TNFRSF1A was analyzed in 720 consecutive children with periodic fever, using denaturing high-performance liquid chromatography and DNA sequencing. Followup data on 11 pediatric patients with TNFRSF1A structural mutations (cysteine or T50M), 23 pediatric patients with an R92Q substitution, and 64 pediatric patients with PFAPA were collected during routine clinic visits. The 50-item Child Health Questionnaire was used to assess health-related quality of life (HRQOL). RESULTS: The frequency of typical TRAPS-related clinical manifestations was significantly lower and the impact of the disease on HRQOL was significantly reduced in patients with the R92Q mutation compared with TRAPS patients carrying structural mutations of TNFRSF1A. Followup data on 11 TRAPS patients with TNFRSF1A structural mutations (mean followup 7.9 years), 16 patients with theR92Q substitution (mean followup 7.3 years), and 64 patients with PFAPA (mean followup 5.2 years) were available. Patients with R92Q mutations and patients with PFAPA displayed a higher rate of self-resolution or amelioration of the fever episodes than did TRAPS patients with structural mutations. CONCLUSION: Although some cases may progress to a more chronic disease course, the majority of children with an R92Q mutation of the TNFRSFA1 gene show a milder disease course than that in children with TNFRSFA1 structural mutations and have a high rate of spontaneous resolution and amelioration of the recurrent fever episodes.

A diagnostic score for molecular analysis of hereditary autoinflammatory syndromes with periodic fever in children.

OBJECTIVE: To identify a set of clinical parameters that can predict the probability of carrying mutations in one of the genes associated with hereditary autoinflammatory syndromes. METHODS: A total of 228 consecutive patients with a clinical history of periodic fever were screened for mutations in the MVK, TNFRSF1A, and MEFV genes, and detailed clinical information was collected. A diagnostic score was formulated based on univariate and multivariate analyses in genetically positive and negative patients (training set). The diagnostic score was validated in an independent set of 77 patients (validation set). RESULTS: Young age at onset (odds ratio [OR] 0.94, P = 0.003), positive family history of periodic fever (OR 4.1, P = 0.039), thoracic pain (OR 4.6, P = 0.05), abdominal pain (OR 33.1, P < 0.001), diarrhea (OR 3.3, P = 0.028), and oral aphthosis (OR 0.2, P = 0.007) were found to be independently correlated with a positive genetic test result. These variables were combined in a linear score whose ability to predict a positive result on genetic testing was validated in an independent data set. In this latter set, the diagnostic score revealed high sensitivity (82%) and specificity (72%) for discriminating patients who were genetically positive from those who were negative. In patients with a high probability of having a positive result on genetic testing, a regression tree analysis provided the most reasonable order in which the genes should be screened. CONCLUSION: The proposed approach in patients with periodic fever will increase the probability of obtaining positive results on genetic testing, with good specificity and sensitivity. Our results further help to optimize the molecular analysis by suggesting the order in which the genes should be screened.

Different clinical and immunological presentation of ataxia-telangiectasia within the same family.

Ataxia-telangiectasia is a rare multisystem neurodegenerative genetic disorder due to mutation of ATM gene. The clinical expression and the immunological abnormalities are variable and apparently not associated with the type of ATM mutations. We report on two siblings affected by A-T with different clinical and immunological presentations; in particular in one the immunological phenotype was reminiscent of hyper IgM syndrome.

Persistent efficacy of anakinra in patients with tumor necrosis factor receptor-associated periodic syndrome.

OBJECTIVE: To evaluate the efficacy and safety of treatment with the interleukin-1 receptor antagonist anakinra in patients with tumor necrosis factor receptor-associated periodic syndrome (TRAPS) requiring high cumulative doses of steroids. METHODS: Four children (mean age 9.1 years [range 4-13 years]) and 1 adult (age 33 years) with TRAPS were enrolled in the study. The 3 children with cysteine mutations (C52Y, C55Y, C43R) had prolonged and frequent attacks of fever. One child with the R92Q mutation and the adult patient with the C43R mutation displayed a more chronic disease course, with fluctuating, nearly continuous symptoms and persistent elevation of acute-phase reactant levels (including serum amyloid A [SAA]). All patients were treated with anakinra (1.5 mg/kg/day). RESULTS: All of the patients had a prompt response to anakinra, with disappearance of symptoms and normalization of acute-phase reactant levels, including SAA. In all pediatric patients, anakinra was withdrawn after 15 days of treatment. After a few days (mean 5.6 days [range 3-8]) a disease relapse occurred, which dramatically responded to reintroduction of anakinra. During the following period of observation (mean 11.4 months [range 4-20 months]), the patients did not experience episodes of fever or other disease-related clinical manifestations. Levels of acute-phase reactants remained in the normal range. No major adverse reactions or severe infections were observed. CONCLUSION: Continuous treatment with anakinra effectively controlled both the clinical and laboratory manifestations in patients with TRAPS and prevented disease relapses.

A nitric oxide/Ca(2+)/calmodulin/ERK1/2 mitogen-activated protein kinase pathway is involved in the mitogenic effect of IL-1beta in human astrocytoma cells.

BACKGROUND AND PURPOSE: Evidence is accumulating to support a role for interleukin-1beta (IL-1beta) in astrocyte proliferation. However, the mechanism by which this cytokine modulates this process is not fully elucidated. EXPERIMENTAL APPROACH: In this study we used human astrocytoma U-373MG cells to investigate the role of nitric oxide (NO), intracellular Ca(2+) concentration ([Ca(2+)](i)), and extracellular signal-regulated protein kinase (ERK) in the signalling pathway mediating IL-1beta-induced astrocyte proliferation. KEY RESULTS: Low IL-1beta concentrations induced dose-dependent ERK activation which paralleled upregulation of cell division, whereas higher concentrations gradually reversed both these responses by promoting apoptosis. Pretreatment with the nonspecific NOS inhibitor, N-omega-nitro-l-arginine methyl ester (L-NAME) or the selective iNOS inhibitor, N-[[3-(aminomethyl)phenyl]methyl]-ethanimidamide dihydrochloride (1400W), antagonized ERK activation and cell proliferation induced by IL-1beta. Inhibition of cGMP formation by the guanylate cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), partially inhibited ERK activation and cell division. Functionally blocking Ca(2+) release from endoplasmic reticulum with ryanodine or 2-aminoethoxydiphenylborane (2-APB), inhibiting calmodulin (CaM) activity with N-(6-aminohexyl)-5-chloro-1-naphthalenesulphonamide hydrochloride (W7) or MAPK kinase activity with 1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthiol]butadiene (U0126) downregulated IL-1beta-induced ERK activation as well as cell proliferation. The cytokine induced a transient and time-dependent increase in intracellular NO levels which preceded elevation in [Ca(2+)](i). CONCLUSIONS AND IMPLICATIONS: These data identified the NO/Ca(2+)/CaM/ERK signalling pathway as a novel mechanism mediating the mitogenic effect of IL-1beta in human astrocytes. As astrocyte proliferation is a hallmark of reactive astrogliosis, our results reveal a new potential target for therapeutic intervention in neuroinflammatory disorders.

Contraception in adolescents with systemic lupus erythematosus.

In the management of adolescents with systemic lupus erythematosus (SLE), sexual activity and prevention of unwanted pregnancies are important topics. Many contraceptive methods are available nowadays. Oral contraceptives (OCs) are the preferred choice among adolescents in general. However, the use of these medications in adolescents with SLE raises serious concerns, particularly the risk of thrombotic events from estrogen exposure and the impact of these medications on lupus activity. In this article, different contraceptive methods available are reviewed and their application in adolescents with SLE is discussed. In conclusion, OCs are the methods of choice in adolescents with stable disease and no antiphospholipid antibodies (aPL) detected. In patients with aPL, fewer options are available, and the selection of the preferred form of contraception should be made on an individual basis.

Role of human-tissue transglutaminase IgG and anti-gliadin IgG antibodies in the diagnosis of coeliac disease in patients with selective immunoglobulin A deficiency.

BACKGROUND: Selective IgA deficiency is associated with coeliac disease, and studies have shown an increased prevalence of coeliac disease in these patients ranging from 0.71 to 30.7%, depending on the test used for screening. AIMS: To determine the sensitivity of IgG anti-gliadin-antibodies and of IgG human-tissue-transglutaminase for diagnosing coeliac disease and assessing its prevalence in subjects with IgA deficiency. SUBJECTS: We tested serum samples from 126 IgA-deficient children (66 female, median age: 10.8 years). METHODS: All samples were analysed to measure IgG anti-gliadin-antibodies and IgG anti-human-tissue-transglutaminase. Patients testing positive to either test underwent intestinal biopsy. Subjects testing positive for IgG anti-human-tissue-transglutaminase underwent genetic testing for the human leucocyte antigen heterodimer. RESULTS: Twenty-seven of 126 subjects tested positive for IgG anti-gliadin-antibodies (five of whom tested positive also for IgG anti-human-tissue-transglutaminase) and 18 (including the aforementioned five) for IgG anti-human-tissue-transglutaminase. Intestinal biopsy was performed in 37 of the 40 patients who tested positive (three subjects refused). Eleven had positive intestinal biopsies all of whom tested positive for IgG anti-human-tissue-transglutaminase, but only five of these tested positive also for IgG anti-gliadin-antibodies. All 22 patients testing positive for anti-gliadin-antibody alone had normal intestinal mucosa. All the patients who tested positive for IgG anti-human-tissue-transglutaminase and underwent genetic screening (15/18) had the coeliac-related human leucocyte antigen. Overall, coeliac disease was diagnosed in 11 of the 126 subjects with IgA deficiency (8.7%). CONCLUSIONS: The prevalence of coeliac disease in subjects with total IgA deficiency was 8.7%. Assay of IgG anti-human-tissue-transglutaminase can be recommended for screening coeliac disease in IgA-deficient subjects.

Serum osteoprotegerin and receptor activator of nuclear factors kB (RANKL) concentrations in normal children and in children with pubertal precocity, Turner's syndrome and rheumatoid arthritis.

BACKGROUND: Osteoprotegerin (OPG) is a secreted member of the TNF receptor superfamily. OPG is made by osteoblastic cells and is expressed in a wide variety of cell and tissue types. It acts as a decoy receptor by binding the receptor activator of nuclear factors kB (RANKL) and preventing RANKL-induced osteoclast formation and differentiation. Numerous cytokines and hormones (TGF-beta, PTH, vitamin D, glucocorticoids and oestrogens) exert their effects on osteoclastogenesis by regulating the production of OPG. PATIENTS AND METHODS: In the present study we compared serum OPG and RANKL concentrations in a group of normal children (1-14 years old) with those of pair-aged children affected by different diseases [Turner's syndrome (TS), early/precocious puberty (PP) and rheumatoid arthritis (RA)]. OPG and RANKL concentrations were measured by an enzyme immunoassay method using a commercial kit. RESULTS: Mean (+/- SD) OPG level in normal children was 4.05 +/- 1.63 pmol/l with no difference between males and females. OPG values in children 1-4 years old (5.87 +/- 2.22 pmol/l) were significantly higher than in children 4-14 years old (3.55 +/- 0.97 pmol/l). OPG levels in children with RA were significantly higher than in controls (6.33 +/- 2.57 pmol/l vs. 4.05 +/- 1.63 pmol/l, P < 0.01); patients with TS or PP had OPG levels superimposable to those of controls (2.61 +/- 0.67 pmol/l and 3.99 +/- 0.85 pmol/l, respectively), but in TS OPG levels were significantly lower than in age-matched females. Mean RANKL concentration in normal subjects was 0.81 +/- 1.55 pmol/l; there was a slight decline in RANKL levels with age. RANKL concentrations in subjects with TS, PP, RA and controls did not differ significantly, and did not differ from those published in adult normal subjects. CONCLUSIONS: It appears from our data that OPG serum levels in healthy children aged > 4 years are similar to those present in young adult men, with higher levels in the first 4 years of life. Although the meaning of the alterations of OPG levels observed in pathological conditions is still obscure, they appear potentially interesting in view of a key role played by this protein in bone homeostasis.

Pulsed electromagnetic fields affect the intracellular calcium concentrations in human astrocytoma cells.

Experiments assessed whether long term exposure to 50 Hz pulsed electromagnetic fields with a peak magnetic field of 3 mT can alter the dynamics of intracellular calcium in human astrocytoma U-373 MG cells. Pretreatment of cells with 1.2 microM substance P significantly increased the [Ca(2+)](i). The same effect was also observed when [Ca(2+)](i) was evaluated in the presence of 20 mM caffeine. After exposure to electromagnetic fields the basal [Ca(2+)](i) levels increased significantly from 143 +/- 46 nM to 278 +/- 125 nM. The increase was also evident after caffeine addition, but in cells treated with substance P and substance P + caffeine we observed a [Ca(2+)](i) decrease after exposure. When we substituted calcium-free medium for normal medium immediately before the [Ca(2+)](i) measurements, the [Ca(2+)](i) was similar to that measured in the presence of Ca(2+). In this case, after EMFs exposure of cells treated with substance P, the [Ca(2+)](i), measured without and with addition of caffeine, declined from 824 +/- 425 to 38 +/- 13 nM and from 1369 +/- 700 to 11 +/- 4 nM, respectively, indicating that electromagnetic fields act either on intracellular Ca(2+) stores or on the plasma membrane. Moreover the electromagnetic fields that affected [Ca(2+)](i) did not cause cell proliferation or cell death and the proliferation indexes remained unchanged after exposure.

The effect of pulsed electromagnetic fields on the physiologic behaviour of a human astrocytoma cell line.

We evaluated the effects of 50 Hz pulsed electromagnetic fields (EMFs) with a peak magnetic field of 3 mT on human astrocytoma cells. Our results clearly demonstrate that, after the cells were exposed to EMFs for 24 h, the basal [Ca(2+)](i) levels increased significantly from 124+/-51 nM to 200+/-79 nM. Pretreatment of the cells with 1.2 microM substance P increased the [Ca(2+)](i) to 555+/-278 nM, while EMF exposure caused a significant drop in [Ca(2+)](i) to 327+/-146 nM. The overall effect of EMFs probably depends on the prevailing Ca(2+) conditions of the cells. After exposure, the proliferative responses of both normal and substance P-pretreated cells increased slightly from 1.03 to 1.07 and 1.04 to 1.06, respectively. U-373 MG cells spontaneously released about 10 pg/ml of interleukin-6 which was significantly increased after the addition of substance P. Moreover, immediately after EMF exposure and 24 h thereafter, the interleukin-6 levels were more elevated (about 40%) than in controls. On the whole, our data suggest that, by changing the properties of cell membranes, EMFs can influence Ca(2+) transport processes and hence Ca(2+) homeostasis. The increased levels of interleukin-6 after 24 h of EMF exposure may confirm the complex connection between Ca(2+) levels, substance P and the cytokine network.

Nitric oxide modulation of interleukin-1[beta]-evoked intracellular Ca2+ release in human astrocytoma U-373 MG cells and brain striatal slices.

Intracellular Ca(2+) mobilization and release into mammal CSF plays a fundamental role in the etiogenesis of fever induced by the proinflammatory cytokine interleukin-1beta (IL-1beta) and other pyrogens. The source and mechanism of IL-1beta-induced intracellular Ca(2+) mobilization was investigated using two experimental models. IL-1beta (10 ng/ml) treatment of rat striatal slices preloaded with (45)Ca(2+) elicited a delayed (30 min) and sustained increase (125-150%) in spontaneous (45)Ca(2+) release that was potentiated by l-arginine (300 microm) and counteracted by N-omega-nitro-l-arginine methyl ester (l-NAME) (1 and 3 mm). The nitric oxide (NO) donors diethylamine/NO complex (sodium salt) (0.3 and 1 mm) and spermine/NO (0.1 and 0.3 mm) mimicked the effect of IL-1beta on Ca(2+) release. IL-1beta stimulated tissue cGMP concentration, and dibutyryl cGMP enhanced Ca(2+) release. The guanyl cyclase inhibitors 1H-[1,2, 4]oxadiazole[4,3-a] quinoxalin-1-one (100 microm) and 6-[phenylamino]-5,8 quinolinedione (50 microm) counteracted Ca(2+) release induced by 2.5 but not 10 ng/ml IL-1beta. Ruthenium red (50 microm) and, to a lesser extent, heparin (3 mg/ml) antagonized IL-1beta-induced Ca(2+) release, and both compounds administered together completely abolished this response. Similar results were obtained in human astrocytoma cells in which IL-1beta elicited a delayed (30 min) increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) (402 +/- 71.2% of baseline), which was abolished by 1 mm l-NAME. These data indicate that the NO/cGMP-signaling pathway is part of the intracellular mechanism transducing IL-1beta-evoked Ca(2+) mobilization in glial and striatal cells and that the ryanodine and the inositol-(1,4,5)-trisphosphate-sensitive Ca(2+) stores are involved.

The mitochondrial permeability transition and taurine.

Perturbed cellular calcium homeostasis has been implicated in both apoptosis and necrosis, but the role of altered mitochondrial calcium handling in the cell death process is unclear. Recently we found that taurine, a naturally occurring amino acid potentiates Ca2+ sequestration by rat liver mitochondria. These data, which accounted for the taurine antagonism on Ca2+ release induced by the neurotoxins 1-methyl-4-phenylpyridinium plus 6-hydroxy dopamine previously reported, prompted us to investigate the effects of taurine on the permeability transition (PT) induced experimentally by high Ca2+ plus phosphate concentrations. The parameters used to measure the PT were, mitochondrial swelling, cytochrome c release and membrane potential changes. The results showed that, whereas taurine failed to reverse changes of these parameters, cyclosporin A completely reversed them. Even though these results exclude a role in PT regulation under such gross insult conditions, they cannot exclude an important role for taurine in controlling pore-opening under milder more physiological PT-inducing conditions.