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Cav1.2 channel phosphorylation plays an important role in regulating neuronal plasticity by action potential-dependent Ca2+ entry. Most studies of Cav1.2 regulation by phosphorylation have been reported in heart and muscles. Here, we identified phosphorylation sites of neuronal Cav1.2 channel protein purified from rat brain using mass spectrometry. The functional characterization of these phosphorylation sites showed altered voltage-dependent biophysical properties of the channel, without affecting current density. These results show that neuronal Cav1.2 channel is regulated by phosphorylation in a complex mechanism involving multiple phosphorylation sites. [ABSTRACT FROM AUTHOR]

Visualizations of the microwave electric and magnetic near-field distributions of radio-frequency (RF) filters were performed using the technique of thermoelastic optical indicator microscopy (TEOIM). New optical indicators based on periodic dielectric-metal structures were designed for electric field visualization. Depending on the structure orientation, such metasurface-based indicators allow separately visualization of the Ex and Ey components of the in-plane electric field. Numerical simulations were conducted to examine the working principle of the designed indicator structures, and the results were compared to the experimental, showing good agreement. In addition, the 3D visualization of the microwave near-field distribution was built, to show the field intensity and distribution dependencies on the distance from the RF filter. [ABSTRACT FROM AUTHOR]

Visualizations of the microwave electric and magnetic near-field distributions of radio-frequency (RF) filters were performed using the technique of thermoelastic optical indicator microscopy (TEOIM). New optical indicators based on periodic dielectric-metal structures were designed for electric field visualization. Depending on the structure orientation, such metasurface-based indicators allow separately visualization of the Ex and Ey components of the in-plane electric field. Numerical simulations were conducted to examine the working principle of the designed indicator structures, and the results were compared to the experimental, showing good agreement. In addition, the 3D visualization of the microwave near-field distribution was built, to show the field intensity and distribution dependencies on the distance from the RF filter. [ABSTRACT FROM AUTHOR]

In this study, a new optical method is presented to determine the concentrations of NaCl and glucose aqueous solutions by using a thermo-elastic optical indicator microscope. By measuring the microwave near-field distribution intensity, concentration changes of NaCl and glucose aqueous solutions were detected in the 0–100 mg/ml range, when exposed to microwave irradiation at 12 GHz frequency. Microwave near-field distribution intensity decreased as the NaCl or glucose concentration increased due to the changes of the absorption properties of aqueous solution. This method provides a novel approach for monitoring NaCl and glucose in biological liquids by using a CCD sensor capable of visualizing NaCl and glucose concentrations without scanning. [ABSTRACT FROM AUTHOR]

Introduction: The association between nutrition and oral health has been studied in the elderly. This study aimed to examine the impacts of undernutrition and the mothers' socioeconomic and oral health statuses on the incidence of dental caries in Korean preschool children. Methods: Data of 610 children aged 3‐5 years and their mothers who underwent oral examinations and responded to the questionnaires in the 6th KNAHNES were used. Caries prevalence was measured by dft and dt among the primary teeth in children and DMFT among mothers. Dietary reference intake values were used to evaluate nutritional status, a nutritional quality index and the mean nutrient adequacy ratio. Complex sample correlation analysis was performed by using children's dft and dt statuses as dependent variables. Multilevel linear regression was applied to investigate the impacts of undernutrition and mothers' socioeconomic and oral health status on children's dft and dt statuses. Statistical significance was set as P <.05. Results: Factors significantly related to dft in children were age and food. Food insecurity was the only factor significantly associated with dt in children. Children's sex and mother's DMFT were likely to be relevant to dft in children. Children's age and a nutritional quality index value less than 1 were also likely to be relevant to the dt of children. Conclusions: Children with an undernourished status had a higher caries experience. A comprehensive community dental health promotion programme should be developed to prevent the incidence of dental caries in vulnerable undernourished children. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether the rate of tissue temperature rise and decay time can be manipulated by using two different therapeutic ultrasound intensities. Methods: Eighteen healthy participants (age = 25.19 ± 2.6 years, mass = 81.39 ± 19.97 kg, height = 173.36 ± 12.73 cm) had a needle temperature probe placed 1.2 ± 0.18 cm deep into the triceps surae muscle group. On separate visits, two ultrasound treatments (intensities = 1.7 and 1.0 W/cmEighteen healthy participants (age = 25.19 ± 2.6 years, mass = 81.39 ± 19.97 kg, height = 173.36 ± 12.73 cm) had a needle temperature probe placed 1.2 ± 0.18 cm deep into the triceps surae muscle group. On separate visits, two ultrasound treatments (intensities = 1.7 and 1.0 W/cm2) were applied until the tissue temperature increased 5°C. The time it took to cool by 2°C and 3°C and return to baseline values was measured. Results: The high intensity (5.22 ± 3.37 minutes) heated tissues faster than the low intensity (9.66 ± 3.43 minutes) (The high intensity (5.22 ± 3.37 minutes) heated tissues faster than the low intensity (9.66 ± 3.43 minutes) (P =.001), but there was no difference in cooling rates between the ultra-sound intensities to 2°C, 3°C, or baseline values (P =.944). Conclusions: Different therapeutic ultrasound intensities produce different heating rates, but do not alter the length of tissue cooling time. [[Athletic Training & Sports Health Care. 2019;11(6):258–263.] [ABSTRACT FROM AUTHOR]

Bromelain (BR), a protease extracted from Ananas comosus, reportedly possesses pharmacological activities including the reduction of thrombogenesis, and antihypertensive, and antimicrobial effects. This study aimed to investigate the potential effects of BR on oral cancer cells. The effect of BR on the viability of Ca9‐22 and SCC25 cells was determined using the MTT assay. These cells were also treated with different doses of BR, and Western blotting was conducted to monitor apoptosis. Finally, flow cytometry analysis was performed to identify sub‐G1 populations of oral cancer cells. After treatment, the viability of both Ca9‐22 and SCC25 cells was markedly reduced, in a dose‐dependent manner. BR induced poly (ADP‐ribose) polymerase (PARP) and lamin A/C degradation, and generated cleavage products. Flow cytometry analysis showed that BR treatment significantly increased the sub‐G1 population. Our findings therefore indicate that BR has potential as a novel, natural anticarcinogenic medicine. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to examine the oral health-related behaviors in mothers and their children and the prevalence of dental caries in both. Subject and methods: A sample of 2536 children and their mothers was selected from the Fifth Korean National Health and Nutrition Examination Survey. Variables were analyzed using multiple regression to evaluate the prevalence of dental caries among children and mothers, demographic socioeconomic status, and oral health-related behaviors. Results: The average age of the mothers was 40.28 years and that of the children was 10.88 years. Mean DT scores were 0.67 for mothers and 0.29 for children. Mean DMFT scores were 6.63 for mothers and 1.76 for children. The higher the mother's number of decayed, missing, or filled permanent teeth (DMFT score, B = 0.076, P < 0.001) and number of decayed teeth (DT score, B = 0.032, P = 0.038) in their permanent dentition, the higher the children's DMFT score was for their permanent dentition. Children from mothers with low household income levels (B = 0.159, P = 0.043), with dental pain (B = 0.132, P = 0.032), and not using a dental mouth rinse (B = 0.135, P = 0.007) presented with higher DT scores. Children from mothers with low self-perceived oral health status (B = 0.113, P < 0.001), lower usage of dental floss (B = 0.100, P = 0.012), a lower ratio of protein intake to total energy (B = −0.017, P = 0.014), and lower ratio of fat intake (B = −0.009, P = 0.047) showed lower self-perceived oral health status. Conclusion: The better the oral health status of the mother, the better the oral health status of the child was. An effective oral health and education program for mothers should be developed to promote an improved oral health status of their children. [ABSTRACT FROM AUTHOR]

We review the ins and outs of T-channel structure, focusing on the extracellular high-affinity metal-binding site and intracellular loops. The high-affinity metal-binding site was localized to repeat I of Ca3.2. Interestingly, a similar binding site was found in the high voltage-activated Ca2.3 channel where it controls the channels' voltage dependence. Histidine at position 191 has a particularly interesting role in the high-affinity binding site, and its modification plays an important role in channel regulation by pharmacological agents that alter redox reactions. The intracellular loop connecting repeats I and II plays two important roles in Ca3.2 properties: one, its gating; and two, its surface expression. These studies have also identified a highly conserved intracellular gating brake that is predicted to form a helix-loop-helix structure. We conclude that the gating brake establishes important contacts with the gating machinery, thereby stabilizing a closed state of T-channels. This interaction is disrupted by depolarization, allowing the S6 segments to open and allowing Ca ions to flow through. Studies in cultured hippocampal neurons provided novel insights into how mutations found in idiopathic generalized epilepsy patients increase seizure susceptibility by both altering T-current pacemaker currents and by activating Ca-activated transcription factors that regulate dendritic arborization. These studies reveal novel roles for T-channels to control cellular physiology. [ABSTRACT FROM AUTHOR]

It has been established that Ca(V)3.2 T-type voltage-gated calcium channels (T-channels) play a key role in the sensitized (hyperexcitable) state of nociceptive sensory neurons (nociceptors) in response to hyperglycemia associated with diabetes, which in turn can be a basis for painful symptoms of peripheral diabetic neuropathy (PDN). Unfortunately, current treatment for painful PDN has been limited by nonspecific systemic drugs with significant side effects or potential for abuse. We studied in vitro and in vivo mechanisms of plasticity of Ca(V)3.2 T-channel in a leptin-deficient (ob/ob) mouse model of PDN. We demonstrate that posttranslational glycosylation of specific extracellular asparagine residues in Ca(V)3.2 channels accelerates current kinetics, increases current density, and augments channel membrane expression. Importantly, deglycosylation treatment with neuraminidase inhibits native T-currents in nociceptors and in so doing completely and selectively reverses hyperalgesia in diabetic ob/ob mice without altering baseline pain responses in healthy mice. Our study describes a new mechanism for the regulation of Ca(V)3.2 activity and suggests that modulating the glycosylation state of T-channels in nociceptors may provide a way to suppress peripheral sensitization. Understanding the details of this regulatory pathway could facilitate the development of novel specific therapies for the treatment of painful PDN. [ABSTRACT FROM AUTHOR]

The acrosome reaction (AR), a calcium-dependent exocytosis, is required for the mammalian fertilization process. Various ion channels, including T-type calcium channels presenting in the plasma membrane of the sperm head, play an important role in AR. In order to investigate the expression pattern and function of T-type calcium channels in Xenopus fertilization, we cloned partial cDNA sequences of cytoplasmic loops connecting domains II and III of T-type channel isoforms from the Xenopus laevis testis. The translated amino acid sequences of cloned Ca3.1 and Ca3.2 T-type channel cDNAs shared 81 and 96 % identity with those of Xenopus tropicalis, respectively. In addition, in situ hybridization showed that Ca3.1 and Ca3.2 transcripts are expressed in the testis tissues of X. laevis, with Ca3.2 transcripts more greatly expressed in testis than Ca3.1 transcripts. Pharmacological studies showed that treatment with nickel or the drug mibefradil significantly reduced the rate of fertilization in a concentration-dependent manner. Collectively, our findings suggest that Ca3.2 T-type calcium channels may play essential roles in the fertilization process of the amphibian species. [ABSTRACT FROM AUTHOR]

We study the opto-electrical properties of Natronomonas pharaonis sensory rhodopsin II (NpSRII) by using a near-field microwave microprobe (NFMM) under external light illumination. To investigate the possibility of application of NFMM to biological macromolecules, we used time dependent properties of NPSRII before/after light activation which has three distinct states - ground-state, M-state, and O-state. The diagnostic ability of NFMM is demonstrated by measuring the microwave reflection coefficient ( S11) spectrum of NpSRII under steady-state illumination in the wavelength range of 350-650 nm. Moreover, we present microwave reflection coefficient S11 spectra in the same wavelength range for two fast-photocycling rhodopsins: green light-absorbing proteorhodopsin (GPR) and Gloeobacter rhodopsin (GR). In addition the frequency sweep shift can be detected completely even for tiny amounts of sample (∼10-3 OD of rhodopsin). Based on these results NFMM shows both very high sensitivity for detecting conformational changes and produces a good time-resolved spectrum. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Individual pharmacokinetic differences for herb-drug interaction have been associated with genetic variations of the multidrug resistance (MDR) gene. A high level expression of MDR protein increases cellular efflux and might decrease drug sensitivity. This study investigated the drug efflux activity difference of human MDR1 triallelic variant 2677G/T/A (rs2032582), as a nonsynonymous 893Ala/Ser/Thr, using Xenopus laevis oocytes and MDR1 overexpressing LLC-PK1 cells. Two MDR1 variants (2667T/893Ser and 2667A/893Thr) were generated using human MDR1 cDNA (2677G/893Ala). No significant difference in the expression of MDR1 893Ala/Ser/Thr was found in X. laevis oocytes. However, the MDR1 2667A/893Thr variant interestingly showed a significant decrease of efflux activity for both digoxin and daunorubicin compared with those of 893Ala and 893Ser variants. In further investigation assessing the inhibitory effects of three herbal extracts on MDR1, 893Ala and 893Ser showed significant decreases of efflux activities in treatments with P. cocos ( p = 0.005 for 893Ser) and D. dasycarpus ( p = 0.0009 for 893Ala; p = 0.002 for 893Ser) in X. laevis oocytes. The results in this study suggest that herbal medicines could interact with other drugs and change the therapeutic effects depending on the genetic polymorphisms of individuals. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Redox regulation is one of the ubiquitous mechanisms to modulate ion channels. We here investigated how 5,5'-dithio-bis (2-nitrobenzoic acid), a cysteine specific oxidizing reagent, modulates Cav3.1 and Cav3.2 T-type Ca2 + channels expressed in Xenopus oocytes. Application of the reagent inhibited Cav3.1 and Cav3.2 currents in a dose-dependent manner. The oxidizing reagent (1 mM) reduced the peak amplitude of Cav3.1 and Cav3.2 currents by ~50% over 2-3 minutes and the decreased currents were fully recovered upon washout of it. The reagent slowed the activation and inactivation kinetics of Cav3.1, Cav3.2, and Cav3.3 channel currents. Notably, the reagent positively shifted both activation and steady-state inactivation curves of Cav3.1, while it did not those of Cav3.2. Utilizing chimeric channels from Cav3.1 and Cav3.2, we localized the domains III and IV of Cav3.1 responsible for the positive shifts of channel activation and steady-state inactivation. These findings provide hints relevant to the electrophysiological and molecular mechanisms accounting for the oxidative regulation of T-type channels. [ABSTRACT FROM AUTHOR]

Purpose: To correlate the incidence and rate of placental migration with the mode of delivery, pregnancy outcome, and maternal complication according to the location (anterior versus posterior) and type of placenta previa (PP). Methods: We prospectively evaluated the placentas of 98 pregnant women with PP or low-lying placenta (LLP) at the prenatal sonographic examination performed between 20 and 27 gestational weeks. We divided the pregnant women into groups according to type and location of PP. Follow-up sonographic examination was performed between 32 and 37 weeks. We compared incidence of migration to the normal position and calculated the migration rate as the migrated distance divided by the weeks of interval between 2 sonographic examinations. We compared the incidences of cesarean section, fetal outcome, and maternal complications during the pregnancy. Results: The incidence of migration in the group of anterior placentas was significantly higher than that in the group of posterior placentas. The mean migration rate in the anterior group was 2.6 mm/week, whereas that in the posterior group was 1.6 mm/week. The migration rate of incomplete PP was significantly higher than that of LLP. Incidence of cesarean section for nonmigrated PP was significantly higher in the posterior group. The incidences of premature delivery and vaginal spotting were also significantly higher in the posterior group. Conclusion: Anterior PP and LLP may migrate more often and faster than posterior PP. Our results may be useful for planning of prenatal management and counseling patients with PP and LLP. [ABSTRACT FROM AUTHOR]

Abstract: We recently reported that a histidine (H191) in the S3–S4 loop of domain I is critical for nickel inhibition of the Cav3.2 T-type Ca2+ channel. As in Cav3.2, two histidine residues are commonly found in the IS3–IS4 loops of mammalian Cav2.3 Ca2+ channels, which are also blocked by low micromolar concentrations of nickel. We show here by site-directed mutagenesis and electrophysiology that both residues contribute to the nickel sensitivity of Cav2.3, with H183 being more critical than H179. These findings strongly suggest that both H179 and H183 in the IS3–IS4 loop are essential structural determinants required for nickel sensitive inhibition of the Cav2.3. [Copyright &y& Elsevier]

T-type Ca2+ channels play essential roles in numerous cellular processes. Recently, we reported that phorbol-12-myristate-13-acetate (PMA) potently enhanced the current amplitude of Cav3.2 T-type channels reconstituted in Xenopus oocytes. Here, we have compared PMA modulation of the activities of Cav3.1, Cav3.2 and Cav3.3 channels, and have investigated the underlying mechanism. PMA augmented the current amplitudes of the three T-type channel isoforms, but the fold stimulations and time courses differed. The augmentation effects were not mimicked by 4α-PMA, an inactive stereoisomer of PMA, but were abolished by preincubation with protein kinase C (PKC) inhibitors, indicating that PMA augmented T-type channel currents via activation of oocyte PKC. The stimulation effect on Cav3.1 channel activity by PKC was mimicked by endothelin when endothelin receptor type A was coexpressed with Cav3.1 in the Xenopus oocyte system. Pharmacological studies combined with fluorescence imaging revealed that the surface density of Cav3.1 T-type channels was not significantly changed by activation of PKC. The PKC effect on Cav3.1 was localized to the cytoplasmic II–III loop using chimeric channels with individual cytoplasmic loops of Cav3.1 replaced by those of Cav2.1. [ABSTRACT FROM AUTHOR]

Abstract: High voltage-activated Ca2+ channel expression and gating is controlled by their β subunits. Although the sites of interaction are known at the atomic level, how β modulates gating remains to be determined. Using a chimeric approach, β subunit regulation was conferred to a low voltage-activated channel. Regulation was dependent on a rigid linker connecting the α1 interaction domain to IS6. Chimeric channels also revealed a role for IS6 in channel gating. Taken together, these results support a direct coupling model where β subunits alter movements in IS6 that occur as the channel transits between closed, open, and inactivated states. [Copyright &y& Elsevier]

Although T-type Ca2+ channels have been implicated in numerous physiological functions, their regulations by protein kinases have been obscured by conflicting reports. We investigated the effects of protein kinase C (PKC) on Cav3.2 T-type channels reconstituted in Xenopus oocytes. Phorbol-12-myristate-13-acetate (PMA) strongly enhanced the amplitude of Cav3.2 channel currents (∼3-fold). The augmentation effects were not mimicked by 4α-PMA, an inactive stereoisomer of PMA, and abolished by preincubation with PKC inhibitors. Our findings suggest that PMA upregulates Cav3.2 channel activity via activation of oocyte PKC. [Copyright &y& Elsevier]

Molecular diversity in T-type Ca2+ channels is produced by expression of three genes, and alternative splicing of those genes. Prompted by differences noted between rat and human Cav3.3 sequences, we searched for splice variants. We cloned six variants, which are produced by splicing at exon 33 and exon 34. Expression of the variants differed between brain regions. The electrophysiological properties of the variants displayed similar voltage-dependent gating, but differed in their kinetic properties. The functional impact of splicing was inter-related, suggesting an interaction. We conclude that alternative splicing of the Cav3.3 gene produces channels with distinct properties. [Copyright &y& Elsevier]

Ca2+ entry through Cav1.3 Ca2+ channels plays essential roles in diverse physiological events. We employed yeast-two-hybrid (Y2H) assays to mine novel proteins interacting with Cav1.3 and found Snapin2, a synaptic protein, as a partner interacting with the long carboxyl terminus (CTL) of rat Cav1.3L variant. Co-expression of Snapin with Cav1.3L/Cavβ3/α2δ2 subunits increased the peak current density or amplitude by about 2-fold in HEK-293 cells and Xenopus oocytes, without affecting voltage-dependent gating properties and calcium-dependent inactivation. However, the Snapin up-regulation effect was not found for rat Cav1.3S containing a short CT (CTS) in which a Snapin interaction site in the CTL was deficient. Luminometry and electrophysiology studies uncovered that Snapin co-expression did not alter the membrane expression of HA tagged Cav1.3L but increased the slope of tail current amplitudes plotted against ON-gating currents, indicating that Snapin increases the opening probability of Cav1.3L. Taken together, our results strongly suggest that Snapin directly interacts with the CTL of Cav1.3L, leading to up-regulation of Cav1.3L channel activity via facilitating channel opening probability. [ABSTRACT FROM AUTHOR]

Abstract Voltage-dependent activity around the resting potential is determinant in neuronal physiology and participates in the definition of the firing pattern. Low-voltage-activated T-type Ca2 + channels directly affect the membrane potential and control a number of secondary Ca2 + -dependent permeabilities. We have studied the ability of the cloned T-type channels (α1G,H,I) to carry Ca2 + currents in response to mock action potentials. The relationship between the spike duration and the current amplitude is specific for each of the T-type channels, reflecting their individual kinetic properties. Typically the charge transfer increases with spike broadening, but the total Ca2 + entry saturates at different spike durations according to the channel type: 4 ms for α1G; 7 ms for α1H; and > 10 ms for α1I channels. During bursts, currents are inhibited and/or transiently potentiated according to the α1 channel type, with larger effects at higher frequency. The inhibition may be induced by voltage-independent transitions toward inactivated states and/or channel inactivation through intermediate closed states. The potentiation is explained by an acceleration in the channel activation kinetics. Relatively fast inactivation and slow recovery limit the ability of α1G and α1H channels to respond to high frequency stimulation ( > 20 Hz). In contrast, the slow inactivation of α1I subunits allows these channels to continue participating in high frequency bursts (100 Hz). The biophysical properties of α1G, H and I channels will therefore dramatically modulate the effect of neuronal activities on Ca2 + signalling. [ABSTRACT FROM AUTHOR]

Abstract Expression of rat α1G, human α1H and rat α1I subunits of voltage-activated Ca2 + channels in HEK-293 cells yields robust Ca2 + inward currents with 1.25 mm Ca2 + as the charge carrier. Both similarities and marked differences are found between their biophysical properties. Currents induced by expression of α1G show the fastest activation and inactivation kinetics. The α1H and α1I currents activate and inactivate up to 1.5- and 5-fold slower, respectively. No differences in the voltage dependence of steady state inactivation are detected. Currents induced by expression of α1G and α1H deactivate with time constants of up to 6 ms at a test potential of - 80 mV, but currents induced by α1I deactivate about three-fold faster. Recovery from short-term inactivation is more than three-fold slower for currents induced by α1H and α1I in comparison to α1G. In contrast to these characteristics, reactivation after long-term inactivation was fastest for currents arising from expression of α1I and slowest in cells expressing α1H calcium channels. The calcium inward current induced by expression of α1I is increased by positive prepulses while currents induced by α1H and α1G show little ( < 5%) or no facilitation. The data thus provide a characteristic fingerprint of each channel’s activity, which may allow correlation of the α1G, α1H and α1I induced currents with their in vivo counterparts. [ABSTRACT FROM AUTHOR]

We developed a microwave glucose sensor based on the modified first-order Hilbert curve design and measured glucose concentration in aqueous solutions by using a real-time microwave near-field electromagnetic interaction technique. We observed S21 transmission parameters of the sensor at resonant frequencies depend on the glucose concentration. We could determine the glucose concentration in the 0–250 mg/dL concentration range at an operating frequency of near 6 GHz. The measured minimum detectable signal was 0.0156 dB/(mg/dL) and the measured minimum detectable concentration was 1.92 mg/dL. The simulation result for the minimum detectable signal and the minimum detectable concentration was 0.0182 dB/(mg/dL) and 1.65 mg/dL, respectively. The temperature instability of the sensor for human glycemia in situ measurement range (27–34 °C for fingers and 36–40 °C for body temperature ranges) can be improved by the integration of the temperature sensor in the microwave stripline platform and the obtained data can be corrected during signal processing. The microwave signal–temperature dependence is almost linear with the same slope for a glucose concentration range of 50–150 mg/dL. The temperature correlation coefficient is 0.05 dB/°C and 0.15 dB/°C in 27–34 °C and 36–40 °C temperature range, respectively. The presented system has a cheap, easy fabrication process and has great potential for non-invasive glucose monitoring. [ABSTRACT FROM AUTHOR]

Asserts that acrosome reaction (AR) of human spermatozoa is mainly mediated by alpha1H T-type calcium channels. Characterization of the mannose-bovine serum albumin initiated AR; Identification of T-type calcium channels in human testes; Determination of the sub-type of T-type calcium channels involved in the AR.