The serotonergic system in migraine

Serotonin (5–HT) and serotonin receptors play an important role in migraine pathophysiology. Changes in platelet 5–HT content are not casually related, but they may reflect similar changes at a neuronal level. Seven different classes of serotoninergic receptors are known, nevertheless only 5–HT2B–2C and 5HT1B–1D are related to migraine syndrome. Pharmacological evidences suggest that migraine is due to an hypersensitivity of 5–HT2B–2C receptors. m–Chlorophenylpiperazine (mCPP), a 5–HT2B–2C agonist, may induce migraine attacks. Moreover different pharmacological preventive therapies (pizotifen, cyproheptadine and methysergide) are antagonist of the same receptor class. On the other side the activation of 5–HT1B–1D receptors (triptans and ergotamines) induce a vasocostriction, a block of neurogenic inflammation and pain transmission.     

Immunogenicity and protective efficacy of a vaccine prepared from 53 kDa truncated hepatitis E virus capsid protein expressed in insect cells.

Hepatitis E virus (HEV) is an enterically transmitted virus that causes acute hepatitis. Expression of recombinant HEV capsid protein in insect cells results in two major proteolytically-processed products of 56 and 53kDa which consist of amino acids (aa) 112-607 and 112-578, respectively. The only neutralization epitope identified to date is located at least partially between amino acids 578 and 607 meaning it should be present only in the 56 and not in the 53kDa protein. Previously, it was shown that vaccination with the 56kDa protein greatly reduced virus shedding and protected Rhesus monkeys from hepatitis E when challenged with a high intravenous dose of homologous or heterologous HEV. To evaluate the immunogenicity and protective efficacy of the 53kDa protein, we vaccinated Rhesus monkeys with this protein and challenged them with a high or low dose of homologous virus. Vaccination with the 53kDa protein greatly reduced virus shedding but did not protect against hepatitis following the high dose challenge. Virus was not detected in the vaccinated animals following the low dose challenge, suggesting that sterilizing immunity may have been achieved.     

Accidental hypothermia in a child

We report a case of severe accidental hypothermia (24.8 degrees C) in a seven-year-old child due to prolonged exposure to low temperatures and temporary contact with river water. When the patient was seen in hospital, bradycardia (30.min-1), bradypnoea (5. min-1), scarcely reacting pupils, and Glasgow Coma Scale=3 were noted. For rewarming minimally invasive techniques (humidified warmed gases and intravenous solutions at 40 degrees C) were employed with a very successful outcome.     

Disability in migraine patients: Italian experience

Migraine is associated with functional impairment. The migraine disability assessment (MIDAS) scale is a scientific instrument which captures headache–related disability. The Italian version of MIDAS was developed through a multi–step standardized methodology. Studies on Italian clinical samples showed that migraine patients were disabled in all activity domains. Non–work activities were more affected than work activities. Among patients in paid work, most continued working with a headache attack, although productivity was significantly reduced. The Italian MIDAS was used also in patients with transformed migraine and drug overuse. These patients were markedly disabled. MIDAS scores were higher than those found in migraine patients. When disability was assessed after 6 months from withdrawal therapy, MIDAS scores were significantly lower than at baseline. Our results confirmed the negative impact of the lives of headache patients, and suggest the use of MIDAS as a sensitive outcome measure for monitoring patients’ progress.     

Treatment of chronic hepatitis delta virus (HDV) infection with human lymphoblastoid alpha interferon

Ten patients with evidence of continuing HDV replication were treated with lymphoblastoid alpha-interferon and eight more were followed as a non-randomized control group. Four out of eight patients who completed one year of follow-up had cleared HDV-RNA from the serum whilst none of the control group did so. In these four responding cases there was a transient increase in transaminase levels during treatment and in two, this was followed by improvement. One patient also cleared HBV and seroconverted to anti-HBs (antibody to hepatitis B surface antigen--HBsAg). In one patient with sustained loss of HDV, recurrence of HDV infection was detected 18 months after completion of treatment. These data suggest that alpha-interferon can inhibit HDV replication in the short term but relapse after one to two years may occur. Inhibition of HDV-RNA is associated with improvement in the inflammatory liver disease and now larger studies are required to determine whether it influences survival.     

Enhanced antiviral benefit of combination therapy with lamivudine and alpha interferon against WHV replication in chronic carrier woodchucks

Cell culture studies in our laboratory previously demonstrated synergistic antiviral activity for the combinations of lamivudine and a novel recombinant hybrid human alpha B/D interferon (rHu alpha B/D IFN) against hepatitis B virus (HBV) replication. Based on these results, a study was designed to determine if an enhanced antiviral effect with this drug combination could be demonstrated in vivo using the woodchuck hepatitis virus (WHV)/woodchuck experimental model of chronic HBV infection. Both antiviral agents have been shown to be effective against WHV replication in WHV chronic carriers during previous studies by our laboratories. Two combination treatment regimens were compared to matched monotherapies in a placebo-controlled trial. The first used simultaneous administration of rHu alpha B/D IFN and lamivudine for 24 weeks. The other combination treatment regimen used a staggered dosing schedule of 12 weeks of administration of lamivudine alone, followed by 12 weeks of simultaneous dosing with both drugs, followed by 12 weeks of therapy with rHu alpha B/D IFN alone. Both treatment regimens with combinations of lamivudine and rHu alpha B/D IFN were more effective at reducing WHV replication in chronically infected wood-chucks than the corresponding monotherapies. Both combination treatments produced antiviral effects that were at least equal to that expected for additive activity based on estimations generated by Bliss Independence calculations. The staggered treatment regimen reduced viraemia and intrahepatic WHV replication significantly more than that expected for additive interactions, indicating synergistic antiviral effects. These studies demonstrate that combination therapy of chronic WHV infection has enhanced antiviral benefit over corresponding monotherapies and indicate that combination treatment of chronic HBV infection can be superior to therapies using a single antiviral agent.     

Induction of lymphocyte apoptosis by tumor cell secretion of FasL-bearing microvesicles

The hypothesis that FasL expression by tumor cells may impair the in vivo efficacy of antitumor immune responses, through a mechanism known as 'Fas tumor counterattack,' has been recently questioned, becoming the object of an intense debate based on conflicting results. Here we definitely show that FasL is indeed detectable in the cytoplasm of melanoma cells and its expression is confined to multivesicular bodies that contain melanosomes. In these structures FasL colocalizes with both melanosomal (i.e., gp100) and lysosomal (i.e., CD63) antigens. Isolated melanosomes express FasL, as detected by Western blot and cytofluorimetry, and they can exert Fas-mediated apoptosis in Jurkat cells. We additionally show that melanosome-containing multivesicular bodies degranulate extracellularly and release FasL-bearing microvesicles, that coexpress both gp100 and CD63 and retain their functional activity in triggering Fas-dependent apoptosis of lymphoid cells. Hence our data provide evidence for a novel mechanism potentially operating in Fas tumor counterattack through the secretion of subcellular particles expressing functional FasL. Such vesicles may form a sort of front line hindering lymphocytes and other immunocompetent cells from entering neoplastic lesions and exert their antitumor activity.     

Neutralization of a unique, negatively-charged residue in the voltage sensor of KV7.2 subunits in a sporadic case of benign familial neonatal seizures

Benign Familial Neonatal Seizures (BFNS) is a rare, autosomal-dominant epilepsy of the newborn caused by mutations in K_v7.2 (KCNQ2) or K_v7.3 (KCNQ3) genes encoding for neuronal potassium (K⁺) channel subunits. In this study, we describe a sporadic case of BFNS; the affected child carried heterozygous missense mutations in both K_v7.2 (D212G) and K_v7.3 (P574S) alleles. Electrophysiological experiments revealed that the K_v7.2 D212G substitution, neutralizing a unique negatively-charged residue in the voltage sensor of K_v7.2 subunits, altered channel gating, leading to a marked destabilization of the open state, a result consistent with structural analysis of the K_v7.2 subunit, suggesting a possible pathogenetic role for BFNS of this K_v7.2 mutation. By contrast, no significant functional changes appeared to be prompted by the K_v7.3 P574S substitution. Computational modelling experiments in CA1 pyramidal cells revealed that the gating changes introduced by the K_v7.2 D212G increased cell firing frequency, thereby triggering the neuronal hyperexcitability which underlies the observed neonatal epileptic condition.