T-type voltage-gated calcium (Ca2+) channels play critical roles in controlling neuronal excitability, firing patterns, and synaptic plasticity, although the mechanisms and extent to which T-type Ca2+ channels are modulated by G-protein coupled receptors (GPCRs) remains largely unexplored. Investigations into T-type modulation within native neuronal systems have been complicated by the presence of multiple GPCR subtypes and a lack of pharmacological tools to separate currents generated by the three T-type isoforms; Cav3.1, Cav3.2, and Cav3.3. We hypothesize that specific Cav3 subtypes play unique roles in neuronal physiology due to their differential functional coupling to specific GPCRs. Co-expression of T-type channel subtypes and GPCRs in a heterologous system allowed us to identify the specific interactions between muscarinic acetylcholine (mAChR) or metabotropic glutamate (mGluR) GPCRs and individual Cav3 isoforms. Perforated patch recordings demonstrated that activation of Galpha<q/11>-coupled GPCRs had a strong inhibitory effect on Cav3.3 T-type Ca2+ currents but either no effect or a stimulating effect on Cav3.1 and Cav3.2 peak current amplitudes. Further study of the inhibition of Cav3.3 channels by a specific Galpha<q/11>-coupled mAChR (M1) revealed that this reversible inhibition was associated with a concomitant increase in inactivation kinetics. Pharmacological and genetic experiments indicated that the M1 receptor-mediated inhibition of Cav3.3 occurs specifically through a Galpha<q/11> signaling pathway that interacts with two distinct regions of the Cav3.3 channel. As hypothesized, the potentiation of Cav3.1 channels by a Galpha<q/11>-coupled mGluR (mGluR1) initially characterized in the heterologous system was also observed in a native neuronal system: the cerebellar Purkinje cell (PC). In recordings on PCs within acute cerebellar slices, we demonstrated that the potentiation of Cav3.1 currents by mGluR1 activation is strongest near the threshold of T-type currents, enhancing the excitability of PCs. Ultrafast two-photon Ca2+ imaging demonstrated that the functional coupling between mGluR1 and T-type transients occurs within dendritic spines, where synaptic integration and plasticity occurs. A subset of these experiments utilized physiological synaptic activation and specific mGluR1 antagonists in wild-type and Cav3.1 knock-out mice to show that the mGluR1-mediated potentiation of Cav3.1 T-type currents may promote synapse-specific Ca2+ signaling in response to bursts of excitatory inputs.

Inflammatory bowel disease (IBD) alters neuronal regulation of the gastrointestinal (GI) tract. The superior mesenteric ganglia (SMG) contain sympathetic neurons that modulate GI functions such, as motility and blood flow. IBD reduces the release of noradrenaline, a sympathetic neurotransmitter. We hypothesized that the reduction in NA release is due to inhibition of voltage-gated calcium current (ICa), as calcium influx is a regulator of neurotransmitter release. We also hypothesized that tumor necrosis factor α (TNFα), a proinflammatory cytokine elevated during IBD, can also inhibit the ICa of SMG neurons. Therefore, we compared ICa amplitude in neurons from normal mice and mice with dextran sulphate sodium (DSS; 5% w/v)-induced colitis. Neurons dissociated from the SMG were cultured overnight and changes to ICa were investigated using electrophysiological, Ca2+ imaging, PCR and neurotransmitter release techniques. Colitis significantly reduced ICa of SMG neurons by selectively inhibiting N-type Ca2+ channels. This was accompanied by a reduction in mRNA encoding the N-type channel alpha subunit (CaV 2.2) and a rightward shift in the voltage dependence of activation of ICa. Colitis reduced the NA release from the colon and jejunum. Depolarization-induced release of tritiated-NA was inhibited by ω-Conotoxin GVIA (300 nM). These results suggest that the changes in VGCC observed at the cell bodies of SMG neurons were also occurring at the nerve terminals during colitis. Similar experimental techniques were performed using SMG neurons incubated overnight in TNFα (1nM). TNFα decreased ICa and depolarization-induced Ca2+ influx in SMG neurons. Similar to DSS-induced colitis, the reduction in ICa was limited to N-type Ca2+ channels. Preincubation of neurons with SC 514 (20μM) and Bay 11 7082 (1µM), inhibitors of nuclear factor kappa B signaling, prevented the reduction in ICa. Preincubation with the p38 MAPK inhibitor, PD 169316 (30µM), recovered a smaller portion of the reduction in Ca2+ influx. These data suggest that DSS colitis and TNFα inhibit N-type VGCC ICa in sympathetic neurons and identify a novel role for NF-κB and p38 MAPK in the regulation of neurotransmitter release. These findings also suggest that DSS colitis inhibits NA release by altering sympathetic N-type VGCC in the colon and jejunum. / Thesis (Master, Physiology) -- Queen's University, 2008-09-02 12:06:20.438

Sudden cardiac death (SCD) is a leading cause of fatalities. Several methods have been developed to predict instability in myocytes which could lead to SCD. The focus of this study was on altering memory in myocytes, i.e. hysteresis in restitution of action potential duration (APD), by differing levels of calcium. Determination of alteration was implemented by using a diastolic interval (DI) control program that implements a sinusoidal change in DI. Plotting APD versus previous DI, i.e. restitution, produces a hysteresis loop. From these hysteresis loops, five parameters were used to determine measures of memory: area, thickness, overall tilt, max delay and min delay. Calcium levels were then altered with either verapamil or BAPTA-AM. Statistically significant effects were found for the verapamil study, but not for the BAPTA-AM study. Simulations were used to explain significant results. The verapamil findings support clinical studies that have shown verapamil to not have anti-arrhythmic effects. Theory predicts that a decrease in memory would decrease the stability of a system, and perhaps verapamil may not increase stability as hypothesized previously. The results of the BAPTA-AM study were inconclusive, and further investigation is needed before it can be determined that BAPTA-AM has no significant effect on memory.

T-type voltage-gated calcium (Ca2+) channels play critical roles in controlling neuronal excitability, firing patterns, and synaptic plasticity, although the mechanisms and extent to which T-type Ca2+ channels are modulated by G-protein coupled receptors (GPCRs) remains largely unexplored. Investigations into T-type modulation within native neuronal systems have been complicated by the presence of multiple GPCR subtypes and a lack of pharmacological tools to separate currents generated by the three T-type isoforms; Cav3.1, Cav3.2, and Cav3.3. We hypothesize that specific Cav3 subtypes play unique roles in neuronal physiology due to their differential functional coupling to specific GPCRs. Co-expression of T-type channel subtypes and GPCRs in a heterologous system allowed us to identify the specific interactions between muscarinic acetylcholine (mAChR) or metabotropic glutamate (mGluR) GPCRs and individual Cav3 isoforms. Perforated patch recordings demonstrated that activation of Galpha<q/11>-coupled GPCRs had a strong inhibitory effect on Cav3.3 T-type Ca2+ currents but either no effect or a stimulating effect on Cav3.1 and Cav3.2 peak current amplitudes. Further study of the inhibition of Cav3.3 channels by a specific Galpha<q/11>-coupled mAChR (M1) revealed that this reversible inhibition was associated with a concomitant increase in inactivation kinetics. Pharmacological and genetic experiments indicated that the M1 receptor-mediated inhibition of Cav3.3 occurs specifically through a Galpha<q/11> signaling pathway that interacts with two distinct regions of the Cav3.3 channel. As hypothesized, the potentiation of Cav3.1 channels by a Galpha<q/11>-coupled mGluR (mGluR1) initially characterized in the heterologous system was also observed in a native neuronal system: the cerebellar Purkinje cell (PC). In recordings on PCs within acute cerebellar slices, we demonstrated that the potentiation of Cav3.1 currents by mGluR1 activation is strongest near the threshold of T-type currents, enhancing the excitability of PCs. Ultrafast two-photon Ca2+ imaging demonstrated that the functional coupling between mGluR1 and T-type transients occurs within dendritic spines, where synaptic integration and plasticity occurs. A subset of these experiments utilized physiological synaptic activation and specific mGluR1 antagonists in wild-type and Cav3.1 knock-out mice to show that the mGluR1-mediated potentiation of Cav3.1 T-type currents may promote synapse-specific Ca2+ signaling in response to bursts of excitatory inputs.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 98-113).

Ziel: Das Ziel dieser Studie war es den Zusammenhang zwischen Zahnextraktionen und Patientenfaktoren in 3 Deutschen Zahnarztpraxen zu untersuchen. Material & Methoden: In einer retrospektiven Auswertung aller Patientenkarten von 3 deutschen Zahnarztpraxen wurden Extraktionsfälle ab Januar 2007 (Praxis 1), Mai 2010 ( Praxis 2) und Januar 2010 ( Praxis 3 ) auf Extraktionen hin durchsucht, bis in jeder Praxis jeweils 100 Extraktionspatienten gefunden wurden, die die Einschlusskriterien erfüllten. Alle Patienten ohne Extraktionen die innerhalb dieses Zeitraumes behandelt wurden und die die Einschlusskriterien erfüllten, dienten als Kontrollgruppe. Es wurden nur Patienten eingeschlossen (Fall und Kontrollgruppe), von denen die spezifischen Patientendaten zur Verfügung standen. Alle Patientendaten wurden in einem „Case-Report-Form\"-Formular (CRF) erfasst. Die individuellen Parameter der Patienten der Fallgruppe und der Kontrollgruppe wurden verglichen. Mittels schrittweiser logistischer Regressionsanalyse konnten die Faktoren für ein Extraktionsrisiko bestimmt werden. Ergebnisse: Insgesamt wurden 2174 Patientenakten untersucht (Fallgruppe 300; Kontrollgruppe 1874). Die Gesamtsumme der Zähne vor der Extraktionstherapie betrug 54316. In der Fallgruppe wurden insgesamt 459 Zähne extrahiert. Die Patienten der Fallgruppe waren im Schnitt mehr als 6,7 Jahre älter als die Patienten der Kontrollgruppe(52,4/45,7 Jahre (P< 0,001)), sie waren zu einem größeren Anteil männlich. (58/ 52%) ,es gab eine höhere Zahl an Rauchern, es gab vermehrt Patienten mit einer Kalziumkanalblocker Medikation [15/8 % (p<0,001)] und der parodontale Befund festgestellt mittels PSI der Fallgruppe war schlechter als der der Kontrollgruppe [PSI 2,5/1,8 , (p<0,001)]. Das Risiko einer Zahnextraktion im Allgemeinen und in Folge von Parodontalerkrankungen waren assoziiert mit Kalziumkanalblockermedikation, (OR 1,49/1,65) aktivem Rauchen (OR 1,35/1,71), Alter (10Jahre) OR 1,13/1,37 , Praxis Nr.1 (1,48/1,99) und der Anzahl der Sextanten mit dem PSI Code 4 (1,33/1,76) (p<0,001). Schlussfolgerung: Kalziumkanalblockermedikation, aktives Rauchen, Alter, Zahnarzt und die Anzahl der Sextanten mit einem PSI Wert 4 sind Risikoindikatoren für Zahnextraktionen. Nutzen : Kalziumkanalblockermedikation kann das Extraktionsrisiko erhöhen. Zahnverlust zieht in den meisten Fällen Zahnersatz nach sich, welcher in aller Regel aufwändig ist, den Patienten zusätzliche Belastungen abverlangt und die Kosten einer Therapie erhöht. Die Information über die Einnahme von Kalziumkanalblockern ist ein leicht zu erfassender Parameter und könnte als Indikator genutzt werden, um Betreuungsintervalle zu verkürzen. Es muss jedoch noch geprüft werden, ob eine intensivere Betreuung dieser Patienten deren Zahnextraktionsrate tatsächlich verringern kann.

Background: Gingival enlargement (GE) is a frequent finding in cyclosporin users. The mechanisms of this association are not totally known and point out to a multifactorial model, with dose and associations with calcium channel blockers. Novel immunosuppression protocols are adjusting for drugs and dosages. Aim: This study aimed at investigating the prevalence and severity of gingival enlargement in renal transplanted individuals under cyclosporin and possible associations with clinical and pharmacological findings. Methods: With a cross- sectional design, 63 renal transplanted patients under cyclosporin therapy from the University Hospital of the Santa Maria Federal University were examined. Demographic, pharmacological and periodontal variables were assessed. Data analysis, independent sample t test and chi square were used to compare means values of different variables, comparing groups with or without gingival enlargement. Results: A response rate of 86,30% was achieved. In total, 40% of the patients presented some degree of GE. Eleven presented scores >10% and only 5 presented scores of 30%. Mean value for GE was low (6,79±15,83). Patients under nifedipine presented higher prevalence of GE, without reaching statistical significance. Mean values for serum levels of CsA were 3,20±0,94 mg/kg/day and 156,12±162,75 ng/ml, respectively. No statistically significant differences among individuals with or without GE was obtained relating to the use of nifedipine and/or none/verapamil. Conclusion: A lower prevalence and severity of GE was found in relation to previous studies, independent to the drug association. / Justificativa: Aumento gengival (AG) é um achado freqüente em pacientes que utilizam Ciclosporina (CsA). Os mecanismos dessa associação não são totalmente conhecidos e apontam para um modelo multifatorial, com doses e associações com outras drogas, como bloqueadores de canais de cálcio (BCC). Novos protocolos de imunossupressão vêm ajustando fármacos e doses visando obter melhores resultados na terapia, diminuindo também os efeitos adversos. Objetivo: Este estudo tem por objetivo investigar a prevalência e a gravidade de aumento gengival em transplantados renais medicados com CsA, e possíveis associações com fatores farmacológicos e clínicos. Metodologia: Utilizando um delineamento transversal, foram examinados 63 transplantados renais em terapia com CsA no Hospital Universitário de Santa Maria (HUSM). Dados demográficos, farmacológicos e periodontais foram coletados. Para a análise dos dados, foram utilizados o teste t não-pareado e qui-quadrado a fim de comparar as médias das variáveis para os grupos com e sem aumento gengival. Resultados: Uma taxa de resposta de 86,3% foi obtida. Ao todo 40% dos pacientes apresentaram algum grau de AG. Onze apresentaram escores acima de 10% e apenas 5 com 30%. A média de AG foi baixa (6,79). Pacientes que utilizam nifedipina apresentaram maior prevalência de AG, sem significância estatística. As médias de dosagem e níveis séricos de CsA foram 3,20 mg/kg/dia e 156,12 ng/ml, respectivamente. Não houve diferença estatística dessas variáveis entre os indivíduos com e sem aumento gengival e entre os gruposnifedipina e sem BCC ou verapamil. Conclusão: No presente estudo, o AG associado à CsA apresentou valores de prevalência e gravidade reduzidos , independentemente das interações medicamentosas.

Background: In the United States, one-third of adults have hypertension (HTN). Among African American (AA) adults, 43% of men and 45.7% of women have HTN. HTN in the AA adult population is more severe and occurs earlier in life compared to Caucasian adults, putting them at increased risk for cardiovascular events and renal disease. The Eighth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 8) Guideline Recommendations 7 and 8 were developed to aid in appropriate treatment and management of hypertensive AA adults. Purpose: The purpose of this Doctor of Nursing Practice (DNP) project was to improve the care, management, and outcomes of hypertensive AA adults by identifying current JNC 8 guideline prescribing patterns among a sample of hospitalized patients. The first project aim was to determine provider-prescribing rates of thiazide diuretics (TDs) and calcium channel blockers (CCBs) in newly diagnosed AA adults with HTN. The second project aim was to determine if AA adults previously diagnosed with HTN were currently prescribed TD and/or CCB medications. Methods: A retrospective medical record review of AA adult patients with a new HTN diagnosis or previously diagnosed with HTN was selected for this project. Participants were discharged from Medical City Dallas between 01/01/2017 and 03/31/2017. Results: In newly diagnosed participants with HTN, none were prescribed a TD (0%) and two were prescribed a CCB (40%). In previously diagnosed participants with HTN, 30 participants (16.3%) were prescribed a TD and/or CCB upon admission and 29 participants (15.76%) were prescribed a TD and/or CCB upon discharge. Among prescribing providers, beta blockers and other class hypertensive medications (i.e., furosemide, hydralazine, clonidine, and spironolactone) were most widely ordered for participants. Conclusions: The results of this DNP project display low provider compliance rates to guideline-recommended pharmacological therapy AA adults. This outcome highlights several potential reasons for the low adherence rates, including lack of provider documentation, lack of provider rationale for treatment selections, provider knowledge of HTN CPGs, and data analysis of prescribed medications. These factors present the opportunity for further research to identify the root cause of low compliance.

The expansion of the voltage-gated calcium channel alpha 1 subunit families (CACNA1) of L and N types was investigated by combining phylogenetic analyses (neighbour-joining and maximum likelihood) with chromosomal data. Neighbouring gene families were analysed to see if the chromosomal regions duplicated through whole genome doublings in vertebrates. Results show that both types of CACNA1 expanded in two ancient whole genome duplications as parts of larger genomic regions. Many gene families in these regions obtained copies in an additional teleost-specific genome duplication. This diversification of CACNA1 genes probably contributed to evolutionary innovations in nervous system function.