Multiomics Approach Reveals Serum Biomarker Candidates for Congenital Zika Syndrome.

The Zika virus (ZIKV) can be vertically transmitted, causing congenital Zika syndrome (CZS) in fetuses. ZIKV infection in early gestational trimesters increases the chances of developing CZS. This syndrome involves several pathologies with a complex diagnosis. In this work, we aim to identify biological processes and molecular pathways related to CZS and propose a series of putative protein and metabolite biomarkers for CZS prognosis in early pregnancy trimesters. We analyzed serum samples of healthy pregnant women and ZIKV-infected pregnant women bearing nonmicrocephalic and microcephalic fetuses. A total of 1090 proteins and 512 metabolites were identified by bottom-up proteomics and untargeted metabolomics, respectively. Univariate and multivariate statistical approaches were applied to find CZS differentially abundant proteins (DAP) and metabolites (DAM). Enrichment analysis (i.e., biological processes and molecular pathways) of the DAP and the DAM allowed us to identify the ECM organization and proteoglycans, amino acid metabolism, and arachidonic acid metabolism as CZS signatures. Five proteins and four metabolites were selected as CZS biomarker candidates. Serum multiomics analysis led us to propose nine putative biomarkers for CZS prognosis with high sensitivity and specificity.

Phytochemical analysis of carotenoid profile in Mentha piperita and Artemisia vulgaris: cytotoxicity in tumoral cells and evaluation of plasmid DNA cleavage.

Several medicinal plants have been administered to cancer patients attributed to their anticarcinogenic and chemoprotective properties, in addition to lower toxicity compared to traditional therapies. The aim was to investigate the antioxidant properties and carotenoid composition of aqueous extracts of Mentha piperita or Artemisia vulgaris which were previously found to exert beneficial effects on human health through diet. aqueous extracts exhibited potent antioxidant activity. A diversity of carotenoids was identified in these extracts using HPLC-PDA-MS/MS. Both extracts contained predominantly all-trans-lutein as the main component within this class. In order to investigate antioxidant properties, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) techniques were used. The (3-4,5 dimethylthiazol-2, 5 diphenyl tetrazolium bromide) (MTT) and Crystal Violet assays assessed cellular cytotoxicity. Assessments of presence of reactive species were carried out following exposure of oral squamous cell carcinoma cell line (SCC-4) to various aqueous extracts of M piperita or A vulgaris utilizing dichlorofluorescein diacetate (DCFH-DA) and nitric oxide (NO) assays. Exposure to these extracts induced severe cytotoxic effects, which led to investigation of the biochemical and molecular mechanisms underlying this observed effect. Data demonstrated that both solutions induced oxidative stress and DNA damage, especially at higher concentrations using agarose gel subjected to electrophoresis. It is known that exposure to excess amounts of antioxidants results in a prooxidant effect which is beneficial in cancer therapy. Further, the extracts were found to reduce viability of SCC-4 in culture, indicating that this antitumoral activity may be of therapeutic importance and requires further study.

Proteomics and Metabolomics in Congenital Zika Syndrome: A Review of Molecular Insights and Biomarker Discovery.

Zika virus (ZIKV) infection can be transmitted vertically, leading to the development of congenital Zika syndrome (CZS) in infected fetuses. During the early stages of gestation, the fetuses face an elevated risk of developing CZS. However, it is important to note that late-stage infections can also result in adverse outcomes. The differences between CZS and non-CZS phenotypes remain poorly understood. In this review, we provide a summary of the molecular mechanisms underlying ZIKV infection and placental and blood-brain barriers trespassing. Also, we have included molecular alterations that elucidate the progression of CZS by proteomics and metabolomics studies. Lastly, this review comprises investigations into body fluid samples, which have aided to identify potential biomarkers associated with CZS.

Reduction of Helicobacter pylori cells in rural water supply using slow sand filtration.

Helicobacter pylori is a microorganism that infects 60% of the population and is considered the main cause of atrophic gastritis, gastric and duodenal ulcers, and gastric cancer. Different emerging pathogens have been found in drinking water and their presence is considered to be an important public health problem. For this reason, it is necessary to carry out the validation of reliable technologies for this type of pathogens and evaluate their performance. This paper reports, for the first time, H. pylori reduction in a drinking water pilot plant of two slow sand filters (SSF). Inlet water was taken from a gravel filtration system of a rural water supply in Colombia and then inoculated with viable cells of H. pylori. By determining the Genomic Units (GU) through quantitative Polymerase Chain Reaction (qPCR), the concentration of GU/sample was measured. In the inlet water amplification for SSF1 and SSF2 were 5.13 × 102 ± 4.48 × 102 and 6.59 × 102 ± 7.32 × 102, respectively, while for the treated water they were 7.0 ± 5.6 and 2.05 × 101 ± 2.9 × 101 GU/sample for SSF1 and SSF2, respectively. The SSF pilot plant reached up to 3 log reduction units of H. pylori; therefore, since there is not an H. pylori contamination indicator and its periodic monitoring is financially complicated, the SSF could guarantee the drinking water quality necessity that exists in rural areas and small municipalities in developing countries, where infection rates and prevalence of this pathogen are high.

Evaluation of intrinsic and extrinsic factors affecting pregnancy rate in dual-purpose cows under tropical conditions.

Embryo transfer (ET) in bovines was created with the purpose of increasing the pregnancy rate (PR) of animals with high genetic value; however, multiple factors have been found to affect the success of this reproductive biotechnology. These factors are frequently grouped in intrinsic and extrinsic factors. Thus, the objective of the present experiments was to assess the effect of intrinsic and extrinsic factors on the pregnancy rate under tropical conditions. To do this a total of 648 embryo transfer (ET) procedures were performed between January and December 2021. The intrinsic factors were size and location of the corpus luteum, body condition, genetic group, age and parity; while extrinsic factors were location of the farm, environmental comfort, season in which the ET was carried out, prevailing weather conditions, and the preservation, quality, and the development stage of embryos at the time of ET. A χi2 was used for analysis of main effects, and logistic regression analysis to calculate the probability of pregnancy and the association between intrinsic or extrinsic factors; additionally, a multivariate analysis of data clusters was used to find a linkage between the effects. While recipient female age had a negative effect (Odds ratio = 0.345-0.871) on PR (p < 0.05), being higher in younger cows, the rest of the intrinsic factors did not affect the PR. The significant (p < 0.05) extrinsic factors were THI category, season of year and type of embryo preservation, showing that the highest PR (p < 0.05) was obtained in the comfort THI category, during the winter season and using fresh embryos for transfer. The clustering analysis did not show any linkage between PR and intrinsic factors, while a linkage (p < 0.05) was found with season of the year and embryo preservation as extrinsic factors. It is concluded that age of the recipient cow and environmental conditions at the time of the embryo transfer are key factors to be considered for a successful pregnancy rate from in-vitro ET programs using dual-purpose cows under tropical conditions.

The oldest unvaccinated Covid-19 survivors in South America.

BACKGROUND: Although older adults are at a high risk of severe or critical Covid-19, there are many cases of unvaccinated centenarians who had a silent infection or recovered from mild or moderate Covid-19. We studied three Brazilian supercentenarians, older than 110 years, who survived Covid-19 in 2020 before being vaccinated. RESULTS: Despite their advanced age, humoral immune response analysis showed that these individuals displayed robust levels of IgG and neutralizing antibodies (NAbs) against SARS-CoV-2. Enrichment of plasma proteins and metabolites related to innate immune response and host defense was also observed. None presented autoantibodies (auto-Abs) to type I interferon (IFN). Furthermore, these supercentenarians do not carry rare variants in genes underlying the known inborn errors of immunity, including particular inborn errors of type I IFN. CONCLUSION: These observations suggest that their Covid-19 resilience might be a combination of their genetic background and their innate and adaptive immunity.

Effect of eye laterality on correction of myopic astigmatism with small incision lenticule extraction (SMILE) using vector analysis.

PURPOSE: To compare the vector analysis, visual, and refractive outcomes after myopic astigmatic correction using SMILE between the right and left eyes. METHODS: This is a retrospective study including 41 right and 40 left eyes that underwent SMILE for correction of myopic astigmatism greater than 0.75 diopters (D) with a follow-up of at least 3 months. Vector analysis for astigmatic correction was done. Visual and refractive parameters were compared between both groups by measuring mean postoperative logMAR uncorrected distance visual acuity, mean postoperative spherical equivalent (SE), cylinder, and refractive predictability in terms of SE and cylindrical correction. Efficacy and safety of SMILE were also determined. RESULTS: No significant difference was found between vector outcomes except for angle of error (AE). The right eye group yielded a negative mean AE (- 2.71 ± 5.35), while the left eye group yielded a positive mean AE (0.23 ± 9.60). Correction index, magnitude of error and refractive predictability of cylindrical correction showed undercorrection of astigmatism in both groups. The right eye group showed lower predictability for higher cylindrical correction. Visual outcomes were similar for both eyes. CONCLUSION: Rotational errors account for vectorial outcome differences between right and left eyes. Despite achieving good visual and refractive outcomes with low cylinder correction, the tendency to undercorrect between eyes due to this error may be more evident when treating higher amounts of astigmatism. More careful preoperative control for cyclotorsion is warranted for right eyes compared to left eyes.

Shifts in Drug Use Behavior Among Electronic Dance Music Partygoers in New York During COVID-19 Social Distancing.

Background: Little is known about how COVID-19-related social distancing has affected illegal drug use. We surveyed electronic dance music (EDM) partygoers-a population known for high levels of drug use-to determine whether their drug use patterns had changed during state-mandated social distancing in New York. Methods: Individuals were recruited online and screened for eligibility throughout April and May 2020. We surveyed 128 eligible adults and queried, retrospectively, whether their drug use behavior had changed during COVID-19-related social distancing. Results: Most participants reporting past-three-month use reported decreased frequency of use during COVID-19-related social distancing. Specifically, 78.6% reduced frequency of use of cocaine, 71.1% reduced frequency of use of ecstasy/MDMA/Molly, and 68.0% reduced frequency of use of LSD. Although some participants reported increased frequency of use of cocaine (7.1%), ecstasy (7.9%), or LSD (12.0%), 35.0% reported increased frequency of cannabis use. Most (66.7%) of those reporting cocaine use reduced the amount used. The majority of those reporting use of cannabis, ecstasy, cocaine, and/or LSD reported that drug cost (80.0-84.0%) and drug quality (84.2-92.0%) did not change during social distancing. Having a college degree was associated with higher odds for decreasing frequency of cannabis use. Older participants (ages ≥23) were at lower odds for decreasing frequency of cocaine use, as were those earning >$500 per week, and participants who attended EDM events biweekly or more often were at higher odds for decreasing frequency of LSD use. Conclusions: Participants in this sample tended to reduce party drug use during COVID-19-related social distancing.

Reliability of a Rapid Screener for an Intercept Survey about Drug Use.

Intercept surveys are a relatively inexpensive method to rapidly collect data on drug use. However, querying use of dozens of drugs can be time-consuming. We determined whether using a rapid screener is efficacious in detecting which participants use drugs and should be offered a full survey which asks more extensively about use.We surveyed 103 adults (age 18-29) on streets of Manhattan, NY in 2019 to test the reliability of a screener which queried past-year use of six drugs. Those reporting any drug use on the screener (and a third of those not reporting drug use) were offered the full survey which queried use of 97 drugs. We compared self-reported use on the screener to the full survey.Self-reported use of ecstasy, cocaine, and LSD had high test-retest reliability (Kappa = 0.90-1.00), and the screener had high sensitivity (1.00) and specificity (0.97-1.00) in detecting use of these drugs. Reliability for marijuana (Kappa = 0.62) and nonmedical opioid use (Kappa = 0.75) was lower. The screener had higher sensitivity (0.94) and lower specificity (0.64) in detecting marijuana use, and lower sensitivity (0.71) and higher specificity (0.98) in detecting nonmedical opioid use. Within the full survey, all participants reporting use of amphetamine (nonmedical use), shrooms, poppers, synthetic cannabinoids, synthetic cathinones, novel psychedelics, ketamine, or GHB reported use of at least one drug queried on the screener.Self-reported use of common drugs on a screener can reliably be used as an inclusion criterion for more extensive intercept surveys about drug use behavior.

A qualitative descriptive analysis of effects of psychedelic phenethylamines and tryptamines.

OBJECTIVE: The number of novel psychedelic phenethylamines and tryptamines has continued to increase, but little academic research has focused on the effects of these substances. We sought to determine and compare the subjective effects of various substances. METHODS: We conducted in-depth interviews with 39 adults (75.4% male and 87.2% White) who reported experience using psychedelic phenethylamines and/or tryptamines. Participants described the effects of compounds they have used. We examined the subjective drug effects in a qualitative descriptive manner. RESULTS: Participants reported on the use of 36 compounds. The majority (64.1%) reported the use of 2C series drugs, with 2C-B use being most prevalent; 38.5% reported the use of NBOMe, and 25.6% reported the use of DOx. With regard to tryptamines, 46.2% reported use, and 4-AcO-DMT was the most prevalent drug used in this class. 2C-B was often described as being more favorable than other 2C series compounds with the effects described as being comparable with MDMA and LSD. NBOMe effects were generally described in an unfavorable manner, and the effects of DOx were often described as lasting too long (12-36 hr). The effects of 4-AcO-DMT were often described as mimicking psilocybin. CONCLUSION: Knowing the effects of various compounds can inform education, prevention, and harm reduction efforts regarding the use of these drugs.

On the efficacy of online drug surveys during the time of COVID-19.

Most human subjects research involving contact with participants has been halted in the US due to the COVID-19 crisis. We have been testing an online method to recruit and survey participants as a temporary replacement for our street-intercept survey method. Online surveys already generate less generalizable findings than other surveys, but offering compensation for online survey completion further reduces generalizability because this increases mischievous submissions. In this letter we discuss methods to help detect invalid responses, such as utilizing a screener to test for eligibility and using flags to detect mischievous responses and repeat submissions. We recommend that researchers approach online recruitment and surveying with caution.

Posting, texting, and related social risk behavior while high.

Background: Posting on social media can have lasting consequences in one's social life and career. Research has not yet focused on social media or more modern forms of communication as social risk factors for individuals high on drugs. This study aims to examine prevalence and correlates of engaging in social media posting and related behavior while high. Methods: We examined data from 872 adults (39.8% female) who were surveyed entering electronic dance music (EDM) parties in New York City and reported lifetime illegal drug use. Participants were asked whether they were ever high on a drug while (1) posting on social media, (2) calling or texting someone, and (3) being in a photo. Those answering affirmatively were also asked whether they later regretted the behavior. We examined demographic and drug-related correlates of these behaviors. Results: Of the participants, 34.3% posted on social media while high (with 21.4% regretting it), 55.9% had texted or called someone while high (with 30.5% regretting it), and 47.6% had been in a photo while high (with 32.7% regretting it). Females and young adults (ages 18-24) were at high risk for posting on social media while high and at higher risk for engaging in more of these behaviors. Past-month marijuana users in particular were at increased risk for engaging in each of these behaviors. Conclusion: Engaging in these behaviors while high on drugs appears to be prevalent, and prevention and harm reduction efforts should seek to prevent or reduce likelihood of social harm that can result from such situations.

The influence of viewing a headline about ecstasy/Molly adulteration on future intentions to use.

BACKGROUND: Ecstasy (3,4-methylenedioxymethamphetamine [MDMA]), commonly referred to as Molly in the US, is commonly adulterated with drugs potentially more dangerous than MDMA. Synthetic cathinones ("bath salts") are common adulterants, and use of these compounds tends to be stigmatized. We investigated whether presenting information on the extent of ecstasy being adulterated with "bath salts" affects intentions to use. METHODS: A total of 1,025 adults entering electronic dance music parties were surveyed in 2018. Using an experimental posttest-only design with random assignment, half were randomly assigned to view a published Vice headline about ecstasy/Molly commonly being adulterated with "bath salts." RESULTS: Overall, 30.5% of the sample reported past-year ecstasy use, and before viewing the headline, 16.4% agreed that ecstasy/Molly commonly contains "bath salts." While controlling for pre-test knowledge of "bath salt" adulteration, viewing the headline reduced the odds of intention to use ecstasy/Molly only among non-past-year ecstasy users (Odd ratio [OR] = 0.54; p = .048). Viewing the headline increased the odds (OR = 1.81, p = .030) of past-year ecstasy users' intention to test their ecstasy for adulterants. CONCLUSIONS: Knowledge that ecstasy is commonly adulterated may help reduce the risk for future use among non-recent users and increase the willingness of users to test their ecstasy. This information can be used to target those at risk for ecstasy/Molly use.

Sodium dodecyl sulfate free gel electrophoresis/electroelution sorting for peptide fractionation.

Shotgun proteomics based on peptide fractionation by using liquid chromatography has become the common procedure for proteomic studies, although in the very beginning of the field, protein separation by using electrophoresis was the main tool. Nonetheless, during the last two decades, the electrophoretic techniques for peptide mixtures fractionation have evolved as a result of relevant technological improvements. We also proposed the combination of sodium dodecyl sulfate polyacrylamide gel electrophoresis for protein fractionation and sodium dodecyl sulfate free polyacrylamide gel electrophoresis for peptide separation as a novel procedure for proteomic studies. Here, we present an optimized device for sodium dodecyl sulfate free polyacrylamide gel electrophoresis improving peptide recoveries respect to the established electrophoretic technique off gel electrophoresis meanwhile conserving the excellent resolution described for the former technique in slab gel based systems. The device simultaneously allows the separation and the collection of fractionated peptides in solution.

Testing hair for fentanyl exposure: a method to inform harm reduction behavior among individuals who use heroin.

BACKGROUND: Deaths from fentanyl exposure continue to increase in the US. Fentanyl test strips are now available to test urine for presence of fentanyl, but additional testing methods are needed to determine past exposure and to determine exposure to specific analogs. OBJECTIVES: To investigate exposure to such analogs through hair testing. METHODS: Forty individuals in inpatient detoxification (7.5% female) reporting past-month heroin use were surveyed and provided a hair sample to be tested at a later date. While results could not be provided to patients, they were asked how they would respond if informed that their hair tested positive for fentanyl. UHPLC-MS/MS was used to test for past exposure to fentanyl, six other novel synthetic opioids, and fentanyl biomarkers/metabolites. RESULTS: 27.5% reported known fentanyl use in the past year and 67.5% reported suspected exposure. 97.5% (39 of 40) tested positive for fentanyl, 90.0% tested positive for 4-ANPP (a biomarker) and norfentanyl (a metabolite); 82.5% tested positive for acetyl-fentanyl, 47.5% tested positive for furanyl-fentanyl, and 7.5% tested positive for U-47700. Most participants (82.5%) reported they would warn others about fentanyl if they learned their hair tested positive; 75.0% reported they would try to stop using heroin, and 65.0% reported they would ensure that someone nearby has naloxone to reverse a potential overdose. CONCLUSIONS: Hair testing is useful in detecting past exposure to fentanyl, its analogs, and other novel synthetic opioids. Further research is needed to determine whether individuals who use heroin learning about exposure affects drug-taking and treatment-seeking behavior.

Planned and Unplanned Drug Use during a Night out at an Electronic Dance Music Party.

BACKGROUND: Electronic dance music (EDM) parties at nightclubs and festivals are high-risk scenes for drug use. Although intention to use drugs (such as ecstasy) has been shown to be the most proximal determinant of use, little is known regarding the extent to which drug use is unplanned in this high-risk scene. METHODS: We surveyed 954 adults entering EDM parties in New York City in 2017 and asked about planned drug use that night. A quarter (n = 236) completed the optional online follow-up survey which asked about drug use during their outing. We examined prevalence and correlates of planned and unplanned use. RESULTS: A fifth (21.0%) of attendees reported planning to use a specific drug the night of the party and over a third (35.4%) reported using a drug later that night. A quarter (26.6%) used in an unplanned manner. Unplanned marijuana use was most common (10.7%), followed by unplanned use of ecstasy (7.3%), cocaine (4.7%), amphetamine (1.4%), LSD (1.3%), and MDA (1.1%). Unplanned initiation of ecstasy and PMA also occurred. Unplanned drug use was more likely to occur among those recruited outside of nightclubs compared to festivals. Non-heterosexual participants and those with a college degree or higher were also more likely to engage in unplanned marijuana use compared to heterosexual and less educated participants, respectively. CONCLUSIONS: Unplanned drug use is common at EDM parties. Results can inform prevention and harm reduction in these scenes as unplanned use may exacerbate potential adverse outcomes related to drug use and often extreme party environments.

A Qualitative Investigation Comparing Psychosocial and Physical Sexual Experiences Related to Alcohol and Marijuana Use among Adults.

Alcohol and marijuana are two of the most prevalent psychoactive substances and each may result in distinct psychosocial and physical sexual experiences and different sexual risk behaviors. With marijuana becoming more accepted in the US along with more liberal state-level policies, it is important to examine and compare users' psychosocial and physical sexual experiences and sexual risk behavior associated with these drugs. In this study, we interviewed 24 adults who recently used marijuana before sex. Participants were 50 % female and all self-identified as heterosexual and HIV-negative. Using thematic analysis, we compared self-reported psychosocial and physical sexual experiences of alcohol and marijuana. Participants described differences between drugs with regard to psychosocial (e.g., partner interactions and contexts before sex, partner choice, perceived attractiveness of self and others, disinhibition, and feelings of regret after sex) and physical sexual experiences (e.g., sexual dysfunction, dose effects, sensations of body/sex organs, length and intensity of sex, and orgasm). Alcohol use was commonly associated with social outgoingness and use facilitated connections with potential sexual partners; however, alcohol was more likely than marijuana to lead to atypical partner choice or post-sex regret. Both alcohol and marijuana had a variety of negative sexual effects, and the illegality of marijuana reportedly facilitated intimate encounters. While sexual experiences tended to be similar across males and females, we did find some variation by gender. Results can inform prevention and harm reduction programming that will allow us to design more realistic programs and to craft interventions, which guide potential users to make safer choices.

Attitudes and Beliefs About New Psychoactive Substance Use Among Electronic Dance Music Party Attendees.

BACKGROUND: Attitudes and beliefs about drug use have been shown to be robust correlates of use of drugs such as alcohol, marijuana, and cocaine; however, little is known regarding attitudes or beliefs about new psychoactive substances (NPS). We sought to examine attitudes and beliefs about NPS and how they relate to self-reported use in a high-risk population-electronic dance music (EDM) party attendees. METHOD: 1,048 individuals (age 18-40) were surveyed entering EDM parties in New York City in 2016. We queried lifetime use and attitudes and beliefs specific to NBOMe, 2C series drugs, "bath salts" (synthetic cathinones), tryptamines, dissociative NPS, and synthetic cannabinoids. RESULTS: More than half the sample reported being unfamiliar with NPS other than "bath salts" and synthetic cannabinoids. "Bath salts" received the highest ratings of strong disapproval (34.3%), followed by synthetic cannabinoids (23.3%), compared to other NPS (10-14%). "Bath salts" were perceived to be a great risk by 43.1% of the sample, followed by synthetic cannabinoids (27.0%), and other NPS (12-16%). "Bath salts" were reportedly least likely to be used if offered (2.9%). In multivariable models, reporting no disapproval towards use was associated with increased odds of reporting use of 2C drugs, "bath salts", and tryptamines. Having friends who use and reporting intent to use or willingness to use if offered were also associated with use of various NPS classes. CONCLUSIONS: This study delineated attitudinal and belief-related correlates of use of various NPS classes. Results can inform prevention effects as NPS continue to emerge.

Leptin regulation of inward membrane currents, electrical activity and LH release in isolated bovine gonadotropes.

Leptin, a peptide hormone produced by adipocytes, is recognized as one of the signals involved in the onset of reproductive activity. The leptin receptor has been found in hypothalamic neurons and pituitary gonadotropes, suggesting that the hormone may act at both sites to stimulate the secretion of GnRH and consequently, FSH and LH. In response to a stimulus such as a hypothalamic secretagogue, gonadotropes respond with changes in electrical activity, intracellular Ca2+ and hormone release. The main aim of this report was to investigate whether leptin promotes a change in the electrical and secretory activities of bovine gonadotropes. After 48 h of treatment with leptin (10 nM) significant changes in the action potential properties were observed in gonadotropes, which included an increase in amplitude, time-to-pike and post-hyperpolarization, as well as a decrease in firing threshold. Likewise, leptin induced a significant (∼1.3-fold) up-regulation of voltage-gated Na+ channel current density, and a selective increase (∼2.1-fold) in Ca2+ current density through high voltage-activated channels. Consistent with this, leptin enhanced GnRH-induced secretion of LH measured by ELISA. We suggest that leptin enhances membrane expression of voltage-gated Na+ and Ca2+ channels, which results in a modulation of the action potential properties and an increase in hormone release from gonadotropes.