Congenital Heart Block Maternal Sera Autoantibodies Target an Extracellular Epitope on the α1G T-Type Calcium Channel in Human Fetal Hearts

Background:Congenital heart block (CHB) is a transplacentally acquired autoimmune disease associated with anti-Ro/SSA and anti-La/SSB maternal autoantibodies and is characterized primarily by atrioventricular (AV) block of the fetal heart. This study aims to investigate whether the T-type calcium channel subunit α1G may be a fetal target of maternal sera autoantibodies in CHB.Methodology/Principal Findings:We demonstrate differential mRNA expression of the T-type calcium channel CACNA1G (α1G gene) in the AV junction of human fetal hearts compared to the apex (18-22.6 weeks gestation). Using human fetal hearts (20-22 wks gestation), our immunoprecipitation (IP), Western blot analysis and immunofluorescence (IF) staining results, taken together, demonstrate accessibility of the α1G epitope on the surfaces of cardiomyocytes as well as reactivity of maternal serum from CHB affected pregnancies to the α1G protein. By ELISA we demonstrated maternal sera reactivity to α1G was significantly higher in CHB maternal sera compared to controls, and reactivity was epitope mapped to a peptide designated as p305 (corresponding to aa305-319 of the extracellular loop linking transmembrane segments S5-S6 in α1G repeat I). Maternal sera from CHB affected pregnancies also reacted more weakly to the homologous region (7/15 amino acids conserved) of the α1H channel. Electrophysiology experiments with single-cell patch-clamp also demonstrated effects of CHB maternal sera on T-type current in mouse sinoatrial node (SAN) cells.Conclusions/Significance:Taken together, these results indicate that CHB maternal sera antibodies readily target an extracellular epitope of α1G T-type calcium channels in human fetal cardiomyocytes. CHB maternal sera also show reactivity for α1H suggesting that autoantibodies can target multiple fetal targets. © 2013 Strandberg et al

La valutazione dell'efficienza degli sportelli bancari

Quaderni di ricerca n.55 Dipartimento di economia, Università di Ancon

Tin(IV) and organotin(IV) complexes containing mono or bidentate N-donor ligands. V. Imidazole and imidazoline-2-thione derivatives: synthesis and spectroscopic charaeterization. Comparison with other imidazole tin(IV) complexes

The reactions of imidazole (L-1), benzimidazole (L-2), 2-phenylimidazole (L-3), 1-acetylimidazole (L-4), imidazoline-2(1,3H)-thione (L-5) and 1-methyl-imidazoline-2(3H)-thione (L-6) with RnSnCl4-n (R = Me-3 Bu-n or Ph; n =1, 2 or 3) were investigated. Twenty-seven navel adducts were obtained and characterized by analytical (elemental analysis conductivity and vaporimetric molecular weight measurements) and spectral (IR, far IR H-1 and Sn-119 NMR) data. The ligands L-1, L-2, L-3 and L-4 behave in the monodentate N-donor fashion, whereas L-5 and L-6 behave as monodentate S-donor molecules. Breaking of the N-CO bonds and protonation of imidazolate moiety occurred when the donor L-4 reacts with organotin accepters in not rigorously anhydrous conditions. The behavior of the adducts in acetone and chlorinated solvents is also discussed. Comparison was made with related organotin (IV) complexes of imidazoles

Identit\ue0, profili, interazioni, scritture multimediali: modelli interpretativi e algoritmi per la costruzione di conoscenza on line e per l'analisi dell'interazione on line

La ricerca ha l\u2019obiettivo di individuare modelli interpretativi e algoritmi per l'analisi dell'interazione e della costruzione di conoscenza negli ambienti di apprendimento on line funzionali a supportare in itinere il lavoro dei docenti e dei tutor. In particolare si intende monitorare la partecipazione degli studenti alle attivit\ue0 formative e la costruzione di conoscenza in rete

Identità, profili, interazioni, scritture multimediali: modelli interpretativi e algoritmi per la costruzione di conoscenza on line e per l’analisi dell’interazione on-line

La ricerca ha l'obiettivo di individuare modelli interpretativi e algoritmi per l'analisi dell'interazione e della costruzione di conoscenza negli ambienti di apprendimento on line funzionali a supportare in itinere il lavoro dei docenti e dei tuto

Supplementary Materials to Comparative Exercise Physiology: Retrospective study of standardised field exercise test on injury development, blood lactate and recovery time in endurance horses

This study investigated the effect of environment, horse and type of different field standardised exercise tests (fSET) on incremental lactate concentration and recovery time in endurance horses. Forty-eight endurance horses underwent one or multiple fSET on a 700-m all-weather racetrack. The fSET comprised phase 1 canter at 19.5-21.5 km/h for 19 km (group N), or 37 km split by 20 minutes of rest (group E1) or 37 km (group E2), followed by phase 2 canter at 26-32.6 km/h and phase 3 at 27.7-42.8 km/h, for 1,400 m each for all groups. Blood lactates were recorded after each phase. Linear mixed models were built with blood lactate value and recovery time as dependent variables and horse and environment data, and type of fSET as fixed effect variables, with horse and horse*fSET group as random effects. Data from a total of 130 fSETs were considered; lactate values were 0.78-7.73 mmol/l (median 1.79 mmol/l) for phase 1, 1.70-10.68 mmol/l (median 3.89 mmol/l) for phase 2, and 3.7-20.86 mmol/l (median 8.74 mmol/l) for phase 3. Blood lactate values after phase 1 and phase 2 were significantly lower in group E1 (median 1.49 mmol/l; median 3.12 mmol/l) compared with group N (median 2.77 mmol/l; median 5.28 mmol/l; P<0.001) and group E2 (median 2.06 mmol/l; median 4.39 mmol/l; P<0.001). Blood lactate after phase 3 did not differ between groups. There were two medical and 19 minor musculoskeletal issues within 2 hours after the fSETs. Weather temperature affected blood lactate values after phase 1 and 2 (R=0.62-0.63). Blood lactate after phase 1 (R=0.93) and 2 (R=0.66) affected values after phase 2 and 3, respectively. There was a considerable variation among horses and horse × fSET group random effects. Moreover, blood lactate values are affected by both weather conditions and by horse individual characteristics.</p

Supplementary Material for: Effect of Hypothyroidism and Hyperthyroidism on Tissue Thyroid Hormone Concentrations in Rat

<b><i>Background and Objective:</i></b> The present study was aimed at determining the effects of experimental hypothyroidism and hyperthyroidism on tissue thyroid hormones by a mass spectrometry-based technique. <b><i>Methods:</i></b> Rats were subjected to propylthiouracil treatment or administration of exogenous triiodothyronine (T₃) or thyroxine (T₄). Tissue T₃ and T₄ were measured by liquid chromatography tandem mass spectrometry in the heart, liver, kidney, visceral and subcutaneous adipose tissue, and brain. <b><i>Results:</i></b> Baseline tissue T₃ and T₄ concentrations ranged from 0.2 to 20 pmol <b>∙</b> g^-1 and from 3 to 125 pmol <b>∙</b> g^-1, respectively, with the highest values in the liver and kidney, and the lowest values in the adipose tissue. The T₃/T₄ ratio (expressed as a percentage) was in the 7-20% range in all tissues except the brain, where it averaged 75%. In hypothyroidism, tissue T₃ was more severely reduced than serum free T₃, averaging 1-6% of the baseline versus 30% of the baseline. The extent of tissue T₃ reduction, expressed as percentage of the baseline, was not homogeneous (p < 0.001), with liver = kidney > brain > heart > adipose tissue. The tissue T₃/T₄ ratio significantly increased in all organs except the kidney, averaging 330% in the brain and 50-90% in the other tissues. By contrast, exogenous T₃ and T₄ administration produced similar increases in serum free T₃ and in tissue T₃, and the relative changes were not significantly different between different tissues. <b><i>Conclusions:</i></b> While the response to increased thyroid hormones availability was similar in all tissues, decreased thyroid hormone availability induced compensatory responses, leading to a significant mismatch between changes in serum and in specific tissues

Congenital heart block maternal sera autoantibodies target an extracellular epitope on the α1G T-type calcium channel in human fetal hearts.

Congenital heart block (CHB) is a transplacentally acquired autoimmune disease associated with anti-Ro/SSA and anti-La/SSB maternal autoantibodies and is characterized primarily by atrioventricular (AV) block of the fetal heart. This study aims to investigate whether the T-type calcium channel subunit α1G may be a fetal target of maternal sera autoantibodies in CHB.We demonstrate differential mRNA expression of the T-type calcium channel CACNA1G (α1G gene) in the AV junction of human fetal hearts compared to the apex (18-22.6 weeks gestation). Using human fetal hearts (20-22 wks gestation), our immunoprecipitation (IP), Western blot analysis and immunofluorescence (IF) staining results, taken together, demonstrate accessibility of the α1G epitope on the surfaces of cardiomyocytes as well as reactivity of maternal serum from CHB affected pregnancies to the α1G protein. By ELISA we demonstrated maternal sera reactivity to α1G was significantly higher in CHB maternal sera compared to controls, and reactivity was epitope mapped to a peptide designated as p305 (corresponding to aa305-319 of the extracellular loop linking transmembrane segments S5-S6 in α1G repeat I). Maternal sera from CHB affected pregnancies also reacted more weakly to the homologous region (7/15 amino acids conserved) of the α1H channel. Electrophysiology experiments with single-cell patch-clamp also demonstrated effects of CHB maternal sera on T-type current in mouse sinoatrial node (SAN) cells.Taken together, these results indicate that CHB maternal sera antibodies readily target an extracellular epitope of α1G T-type calcium channels in human fetal cardiomyocytes. CHB maternal sera also show reactivity for α1H suggesting that autoantibodies can target multiple fetal targets