Oncolytic Myxoma virus infects and damages the tegument of the human parasitic flatworm Schistosoma mansoni.

Schistosomiasis is a devastating disease caused by parasitic flatworms of the genus Schistosoma. Praziquantel (PZQ), the current treatment of choice, is ineffective against immature worms and cannot prevent reinfection. The continued reliance on a single drug for treatment increases the risk of the development of PZQ-resistant parasites. Reports of PZQ insusceptibility lends urgency to the need for new therapeutics. Here, we report that Myxoma virus (MYXV), an oncolytic pox virus which is non-pathogenic in all mammals except leporids, infects and replicates in S. mansoni schistosomula, juveniles, and adult male and female worms. MYXV infection results in the shredding of the tegument and reduced egg production in vitro, identifying MYXV as the first viral pathogen of schistosomes. MYXV is currently in preclinical studies to manage multiple human cancers, supporting its use in human therapeutics. Our findings raise the exciting possibility that MYXV virus represents a novel and safe class of potential anthelmintic therapeutics.

Schistosome TRPML channels play a role in neuromuscular activity and tegumental integrity.

Schistosomiasis is a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma. Mono-therapeutic treatment of this disease with the drug praziquantel, presents challenges such as inactivity against immature worms and inability to prevent reinfection. Importantly, ion channels are important targets for many current anthelmintics. Transient receptor potential (TRP) channels are important mediators of sensory signals with marked effects on cellular functions and signaling pathways. TRPML channels are a class of Ca2+-permeable TRP channels expressed on endolysosomal membranes. They regulate lysosomal function and trafficking, among other functions. Schistosoma mansoni is predicted to have a single TRPML gene (SmTRPML) with two splice variants differing by 12 amino acids. This study focuses on exploring the physiological properties of SmTRPML channels to better understand their role in schistosomes. In mammalian cells expressing SmTRPML, TRPML activators elicit a rise in intracellular Ca2+. In these cells, SmTRPML localizes both to lysosomes and the plasma membrane. These same TRPML activators elicit an increase in adult worm motility that is dependent on SmTRPML expression, indicating a role for these channels in parasite neuromuscular activity. Suppression of SmTRPML in adult worms, or exposure of adult worms to TRPML inhibitors, results in tegumental vacuolations, balloon-like surface exudates, and membrane blebbing, similar to that found following TRPML loss in other organisms. Together, these findings indicate that SmTRPML may regulate the function of the schistosome endolysosomal system. Further, the role of SmTRPML in neuromuscular activity and in parasite tegumental integrity establishes this channel as a candidate anti-schistosome drug target.

Longitudinal Neurocognitive Effects of Combined Electroconvulsive Therapy (ECT) and Pharmacotherapy in Major Depressive Disorder in Older Adults: Phase 2 of the PRIDE Study.

OBJECTIVE: There is limited information regarding neurocognitive outcomes of right unilateral ultrabrief pulse width electroconvulsive therapy (RUL-UB ECT) combined with pharmacotherapy in older adults with major depressive disorder. We report longitudinal neurocognitive outcomes from Phase 2 of the Prolonging Remission in Depressed Elderly (PRIDE) study. METHOD: After achieving remission with RUL-UB ECT and venlafaxine, older adults (≥60 years old) were randomized to receive symptom-titrated, algorithm-based longitudinal ECT (STABLE) plus pharmacotherapy (venlafaxine and lithium) or pharmacotherapy-only. A comprehensive neuropsychological battery was administered at baseline and throughout the 6-month treatment period. Statistical significance was defined as a p-value of less than 0.05 (two-sided test). RESULTS: With the exception of processing speed, there was statistically significant improvement across most neurocognitive measures from baseline to 6-month follow-up. There were no significant differences between the two treatment groups at 6 months on measures of psychomotor processing speed, autobiographical memory consistency, short-term and long-term verbal memory, phonemic fluency, inhibition, and complex visual scanning and cognitive flexibility. CONCLUSION: To our knowledge, this is the first report of neurocognitive outcomes over a 6-month period of an acute course of RUL-UB ECT followed by one of 2 strategies to prolong remission in older adults with major depression. Neurocognitive outcome did not differ between STABLE plus pharmacotherapy versus pharmacotherapy alone over the 6-month continuation treatment phase. These findings support the safety of RUL-UB ECT in combination with pharmacotherapy in the prolonging of remission in late-life depression.

Schistosome TRP channels: An appraisal.

Ion channels underlie electrical excitability in cells and are essential for a variety of functions, most notably neuromuscular and sensory activity. They are also validated targets for a preponderance of approved anthelmintic compounds. Transient receptor potential (TRP) channels constitute an ion channel superfamily whose members play important roles in sensory signaling, regulation of ion homeostasis, organellar trafficking, and other key cellular and organismal activities. Unlike most other ion channels, TRP channels are often polymodal, gated by a variety of mechanisms. Furthermore, TRP channels fall into several classes or subtypes based on sequence and structure. Until recently, there had been very little investigation of the properties and functions of TRP channels from parasitic helminths, including schistosomes, but that situation has changed in the past few years. Indeed, it is now clear that at least some schistosome TRP channels exhibit unusual pharmacological properties, and, intriguingly, both a mammalian and a schistosome TRP channel are activated by praziquantel, the current antischistosomal drug of choice. With the latest release of the Schistosoma mansoni genome database, several changes in predicted TRP channel sequences appeared, some of which were significant. This review updates and reassesses the TRP channel repertoire in S. mansoni, examines recent findings regarding these potential therapeutic targets, and provides guideposts for some of the physiological functions that may be mediated by these channels in schistosomes.

Neurocognitive Effects of Combined Electroconvulsive Therapy (ECT) and Venlafaxine in Geriatric Depression: Phase 1 of the PRIDE Study.

OBJECTIVE: There is limited information regarding the tolerability of electroconvulsive therapy (ECT) combined with pharmacotherapy in elderly adults with major depressive disorder (MDD). Addressing this gap, we report acute neurocognitive outcomes from Phase 1 of the Prolonging Remission in Depressed Elderly (PRIDE) study. METHODS: Elderly adults (age ≥60) with MDD received an acute course of 6 times seizure threshold right unilateral ultrabrief pulse (RUL-UB) ECT. Venlafaxine was initiated during the first treatment week and continued throughout the study. A comprehensive neurocognitive battery was administered at baseline and 72 hours following the last ECT session. Statistical significance was defined as a two-sided p-value of less than 0.05. RESULTS: A total of 240 elderly adults were enrolled. Neurocognitive performance acutely declined post ECT on measures of psychomotor and verbal processing speed, autobiographical memory consistency, short-term verbal recall and recognition of learned words, phonemic fluency, and complex visual scanning/cognitive flexibility. The magnitude of change from baseline to end for most neurocognitive measures was modest. CONCLUSION: This is the first study to characterize the neurocognitive effects of combined RUL-UB ECT and venlafaxine in elderly adults with MDD and provides new evidence for the tolerability of RUL-UB ECT in an elderly sample. Of the cognitive domains assessed, only phonemic fluency, complex visual scanning, and cognitive flexibility qualitatively declined from low average to mildly impaired. While some acute changes in neurocognitive performance were statistically significant, the majority of the indices as based on the effect sizes remained relatively stable.

TRP channels as potential targets for antischistosomals.

Ion channels are membrane protein complexes that underlie electrical excitability in cells, allowing ions to diffuse through cell membranes in a regulated fashion. They are essential for normal functioning of the neuromusculature and other tissues. Ion channels are also validated targets for many current anthelmintics, yet the properties of only a small subset of ion channels in parasitic helminths have been explored in any detail. Transient receptor potential (TRP) channels comprise a widely diverse superfamily of ion channels with important roles in sensory signaling, regulation of ion homeostasis, organellar trafficking, and other functions. There are several subtypes of TRP channels, including TRPA1 and TRPV1 channels, both of which are involved in, among other functions, sensory, nociceptive, and inflammatory signaling in mammals. Several lines of evidence indicate that TRPA1-like channels in schistosomes exhibit pharmacological sensitivities that differ from their mammalian counterparts and that may signify unique physiological properties as well. Thus, in addition to responding to TRPA1 modulators, schistosome TRPA1-like channels also respond to compounds that in other organisms modulate TRPV1 channels. Notably, TRPV channel genes are not found in schistosome genomes. Here, we review the evidence leading to these conclusions and examine potential implications. We also discuss recent results showing that praziquantel, the current drug of choice against schistosomiasis, selectively targets host TRP channels in addition to its likely primary targets in the parasite. The results we discuss add weight to the notion that schistosome TRP channels are worthy of investigation as candidate therapeutic targets.

Atypical pharmacology of schistosome TRPA1-like ion channels.

Parasitic flatworms of the genus Schistosoma cause schistosomiasis, a neglected tropical disease estimated to affect over 200 million people worldwide. Praziquantel is the only antischistosomal currently available for treatment, and there is an urgent need for new therapeutics. Ion channels play key roles in physiology and are targets for many anthelmintics, yet only a few representatives have been characterized in any detail in schistosomes and other parasitic helminths. The transient receptor potential (TRP) channel superfamily comprises a diverse family of non-selective cation channels that play key roles in sensory transduction and a wide range of other functions. TRP channels fall into several subfamilies. Members of both the TRPA and TRPV subfamilies transduce nociceptive and inflammatory signals in mammals, and often also respond to chemical and thermal signals. We previously showed that although schistosomes contain no genes predicted to encode TRPV channels, TRPV1-selective activators such as capsaicin and resiniferatoxin elicit dramatic hyperactivity in adult worms and schistosomula. Surprisingly, this response requires expression of a S. mansoni TRPA1-like orthologue (SmTRPA). Here, we show that capsaicin induces a rise in intracellular Ca2+ in mammalian cells expressing either SmTRPA or a S. haematobium TRPA1 orthologue (ShTRPA). We also test SmTRPA and ShTRPA responses to various TRPV1 and TRPA1 modulators. Interestingly, in contrast to SmTRPA, ShTRPA is not activated by the TRPA1 activator AITC (allyl isothiocyanate), nor do S. haematobium adult worms respond to this compound, a potentially intriguing species difference. Notably, 4-hydroxynonenal (4-HNE), a host-derived, inflammatory product that directly activates mammalian TRPA1, also activates both SmTRPA and ShTRPA. Our results point to parasite TRPA1-like channels which exhibit atypical, mixed TRPA1/TRPV1-like pharmacology, and which may also function to transduce endogenous host signals.

Effects of a Course of Right Unilateral Ultrabrief Pulse Electroconvulsive Therapy Combined With Venlafaxine on Insomnia Symptoms in Elderly Depressed Patients.

OBJECTIVE: Antidepressant medications have a variety of effects on sleep, apart from their antidepressant effects. It is unknown whether electroconvulsive therapy (ECT) has effects on perceived sleep in depressed patients. This secondary analysis examines the effects of ECT on perceived sleep, separate from its antidepressant effects. METHODS: Elderly patients with major depressive disorder, as defined by DSM-IV, received open-label high-dose, right unilateral ultrabrief pulse ECT, combined with venlafaxine, as part of participating in phase 1 of the National Institute of Mental Health-supported study Prolonging Remission in Depressed Elderly (PRIDE). Phase 1 of PRIDE participant enrollment period extended from February 2009 to August 2014. Depression severity was measured with the Hamilton Depression Rating Scale-24 item (HDRS24), and measures of insomnia severity were extracted from the HDRS24. Participants were characterized at baseline as either "high-insomnia" or "low-insomnia" subtypes, based upon the sum of the 3 HDRS24 sleep items as either 4-6 or 0-3, respectively. Insomnia scores were followed during ECT and were adjusted for the sum of all the HDRS24 non-sleep items. Generalized linear models were used for longitudinal analysis of insomnia scores. RESULTS: Two hundred forty patients participated, with 48.3% in the high-insomnia and 51.7% in the low-insomnia group. Although there was a reduction in the insomnia scores in the high-insomnia group, only 12.4% of them experienced remission of insomnia after a course of ECT, despite an increase in utilization of sleep aids across the course of ECT, from 8.6% to 23.2%. The degree of improvement in insomnia symptoms paralleled the degree of improvement in non-insomnia symptoms. A "low" amount of improvement on the sum of the HDRS non-insomnia items (HDRS-sleep) was accompanied by a "low" amount of improvement in insomnia scores (change of -1.6 ± 1.2, P < .0001), while a "high" amount of improvement on the sum of the HDRS non-insomnia items was accompanied by a "higher" amount of improvement in insomnia scores (change of -3.1 ± 1.6, P < .0001). After adjustment for non-insomnia symptoms, there was no change in insomnia in the low-insomnia group. CONCLUSIONS: We found that ECT, combined with venlafaxine, has a modest anti-insomnia effect that is linked to its antidepressant effect. Most patients will have some degree of residual insomnia after ECT, and will require some consideration of whether additional, targeted assessment and treatment of insomnia is warranted. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01028508.

Effects of continuation electroconvulsive therapy on quality of life in elderly depressed patients: A randomized clinical trial.

We examined whether electroconvulsive therapy (ECT) plus medications ("STABLE + PHARM" group) had superior HRQOL compared with medications alone ("PHARM" group) as continuation strategy after successful acute right unilateral ECT for major depressive disorder (MDD). We hypothesized that scores from the Medical Outcomes Study Short Form-36 (SF-36) would be higher during continuation treatment in the "STABLE + PHARM" group versus the "PHARM" group. The overall study design was called "Prolonging Remission in Depressed Elderly" (PRIDE). Remitters to the acute course of ECT were re-consented to enter a 6 month RCT of "STABLE + PHARM" versus "PHARM". Measures of depressive symptoms and cognitive function were completed by blind raters; SF-36 measurements were patient self-report every 4 weeks. Participants were 120 patients >60 years old. Patients with dementia, schizophrenia, bipolar disorder, or substance abuse were excluded. The "PHARM" group received venlafaxine and lithium. The "STABLE + PHARM" received the same medications, plus 4 weekly outpatient ECT sessions, with additional ECT session as needed. Participants were mostly female (61.7%) with a mean age of 70.5 ± 7.2 years. "STABLE + PHARM" patients received 4.5 ± 2.5 ECT sessions during Phase 2. "STABLE + PHARM" group had 7 point advantage (3.5-10.4, 95% CI) for Physical Component Score of SF-36 (P < 0.0001), and 8.2 point advantage (4.2-12.2, 95% CI) for Mental Component Score (P < 0.0001). Additional ECT resulted in overall net health benefit. Consideration should be given to administration of additional ECT to prevent relapse during the continuation phase of treatment of MDD. CLINICAL TRIALS.GOV: NCT01028508.

Two-Stage Isothermal Enzymatic Amplification for Concurrent Multiplex Molecular Detection.

BACKGROUND: The wide array of pathogens responsible for infectious diseases makes it difficult to identify causative pathogens with single-plex tests. Although multiplex PCR detects multiple targets, it is restricted to centralized laboratories, which delays test results or makes multiplexing unavailable, depriving healthcare providers of critical, real-time information. METHODS: To address the need for point-of-care (POC) highly multiplexed tests, we propose the 2-stage, nested-like, rapid (<40 min) isothermal amplification assay, dubbed rapid amplification (RAMP). RAMP's first-stage uses outer loop-mediated isothermal amplification (LAMP) primers to amplify all targets with recombinase polymerase amplification (RPA). First-stage amplicons are aliquoted to second stage reactors, each specialized for a specific target, to undergo LAMP. The assay is implemented in a microfluidic chip. LAMP amplicons are detected in situ with colorimetric dye or with a fluorescent dye and a smartphone. RESULTS: In experiments on a benchtop and in a microfluidic format, RAMP demonstrated high level of multiplexing (≥16); high sensitivity (i.e., 1 plaque-forming unit of Zika virus) and specificity (no false positives or negatives); speed (<40 min); ease of use; and ability to cope with minimally processed samples. CONCLUSIONS: RAMP is a hybrid, 2-stage, rapid, and highly sensitive and specific assay with extensive multiplexing capabilities, combining the advantages of RPA and LAMP, while circumventing their respective shortcomings. RAMP can be used in the lab, but one of its distinct advantages is amenability to simple implementation in a microfluidic format for use at the POC, providing healthcare personnel with an inexpensive, highly sensitive tool to detect multiple pathogens in a single sample, on site.

Effects of a right unilateral ultrabrief pulse electroconvulsive therapy course on health related quality of life in elderly depressed patients.

INTRODUCTION: Patients with Major Depressive Disorder (MDD) referred for electroconvulsive therapy (ECT) have poorer Health Related Quality of Life (HRQOL), compared with other patients with MDD, but ECT is associated with significant and durable improvement in HRQOL. However, no prior research has focused exclusively on elderly patients with MDD receiving ECT. METHODS: HRQOL data from 240 depressed patients over the age of 60 was measured with the Medical Outcomes Study Short Form 36 (SF-36). The SF-36 was measured before and after a course of acute ECT. Predictors of change in HRQOL scores were identified by generalized linear modeling. RESULTS: At baseline, participants showed very poor HRQOL. After treatment with ECT, the full sample showed marked and significant improvement across all SF-36 measures, with the largest gains seen in dimensions of mental health. Across all participants, the Physical Component Summary (PCS) score improved by 2.1 standardized points (95% CI, 0.61,3.56), while the Mental Component Summary (MCS) score improved by 12.5 points (95% CI, 7.2,10.8) Compared with non-remitters, remitters showed a trend toward greater improvement in the PCS summary score of 2.7 points (95%CI, -0.45, 5.9), while the improvement in the MCS summary score was significantly greater (8.5 points, 95% CI, 4.6,12.3) in the remitters than non-remitters. Post-ECT SF-36 measurements were consistently and positively related to baseline scores and remitter/non-remitter status or change in depression severity from baseline. Objective measures of cognitive function had no significant relationships to changes in SF-36 scores. LIMITATIONS: This study's limitations include that it was an open label study with no comparison group, and generalizability is limited to elderly patients. DISCUSSION: ECT providers and elderly patients with MDD treated with ECT can be confident that ECT will result in improved HRQOL in the short-term. Attaining remission is a key factor in the improvement of HRQOL. Acute changes in select cognitive functions were outweighed by improvement in depressive symptoms in determining the short term HRQOL of the participants treated with ECT.

TRP channels in schistosomes.

Praziquantel (PZQ) is effectively the only drug currently available for treatment and control of schistosomiasis, a disease affecting hundreds of millions of people worldwide. Many anthelmintics, likely including PZQ, target ion channels, membrane protein complexes essential for normal functioning of the neuromusculature and other tissues. Despite this fact, only a few classes of parasitic helminth ion channels have been assessed for their pharmacological properties or for their roles in parasite physiology. One such overlooked group of ion channels is the transient receptor potential (TRP) channel superfamily. TRP channels share a common core structure, but are widely diverse in their activation mechanisms and ion selectivity. They are critical to transducing sensory signals, responding to a wide range of external stimuli. They are also involved in other functions, such as regulating intracellular calcium and organellar ion homeostasis and trafficking. Here, we review current literature on parasitic helminth TRP channels, focusing on those in schistosomes. We discuss the likely roles of these channels in sensory and locomotor activity, including the possible significance of a class of TRP channels (TRPV) that is absent in schistosomes. We also focus on evidence indicating that at least one schistosome TRP channel (SmTRPA) has atypical, TRPV1-like pharmacological sensitivities that could potentially be exploited for future therapeutic targeting.

Right Unilateral Ultrabrief Pulse ECT in Geriatric Depression: Phase 1 of the PRIDE Study.

OBJECTIVE: The Prolonging Remission in Depressed Elderly (PRIDE) study evaluated the efficacy of right unilateral ultrabrief pulse electroconvulsive therapy (ECT) combined with venlafaxine for the treatment of geriatric depression. METHOD: PRIDE was a two-phase multisite study. Phase 1 was an acute course of right unilateral ultrabrief pulse ECT, combined with open-label venlafaxine at seven academic medical centers. In phase 2 (reported separately), patients who had remitted were randomly assigned to receive pharmacotherapy (venlafaxine plus lithium) or pharmacotherapy plus continuation ECT. In phase 1, depressed patients received high-dose ECT (at six times the seizure threshold) three times per week. Venlafaxine was started during the first week of treatment and continued throughout the study. The primary outcome measure was remission, assessed with the 24-item Hamilton Depression Rating Scale (HAM-D), which was administered three times per week. Secondary outcome measures were post-ECT reorientation and safety. Paired t tests were used to estimate and evaluate the significance of change from baseline in HAM-D scores. RESULTS: Of 240 patients who entered phase 1 of the study, 172 completed it. Overall, 61.7% (148/240) of all patients met remission criteria, 10.0% (24/240) did not remit, and 28.3% (68/240) dropped out; 70% (169/240) met response criteria. Among those who remitted, the mean decrease in HAM-D score was 24.7 points (95% CI=23.4, 25.9), with a mean final score of 6.2 (SD=2.5) and an average change from baseline of 79%. The mean number of ECT treatments to remission was 7.3 (SD=3.1). CONCLUSIONS: Right unilateral ultrabrief pulse ECT, combined with venlafaxine, is a rapidly acting and highly effective treatment option for depressed geriatric patients, with excellent safety and tolerability. These data add to the evidence base supporting the efficacy of ECT to treat severe depression in elderly patients.

A Novel Strategy for Continuation ECT in Geriatric Depression: Phase 2 of the PRIDE Study.

OBJECTIVE: The randomized phase (phase 2) of the Prolonging Remission in Depressed Elderly (PRIDE) study evaluated the efficacy and tolerability of continuation ECT plus medication compared with medication alone in depressed geriatric patients after a successful course of ECT (phase 1). METHOD: PRIDE was a two-phase multisite study. Phase 1 was an acute course of right unilateral ultrabrief pulse ECT, augmented with venlafaxine. Phase 2 compared two randomized treatment arms: a medication only arm (venlafaxine plus lithium, over 24 weeks) and an ECT plus medication arm (four continuation ECT treatments over 1 month, plus additional ECT as needed, using the Symptom-Titrated, Algorithm-Based Longitudinal ECT [STABLE] algorithm, while continuing venlafaxine plus lithium). The intent-to-treat sample comprised 120 remitters from phase 1. The primary efficacy outcome measure was score on the 24-item Hamilton Depression Rating Scale (HAM-D), and the secondary efficacy outcome was score on the Clinical Global Impressions severity scale (CGI-S). Tolerability as measured by neurocognitive performance (reported elsewhere) was assessed using an extensive test battery; global cognitive functioning as assessed by the Mini-Mental State Examination (MMSE) is reported here. Longitudinal mixed-effects repeated-measures modeling was used to compare ECT plus medication and medication alone for efficacy and global cognitive function outcomes. RESULTS: At 24 weeks, the ECT plus medication group had statistically significantly lower HAM-D scores than the medication only group. The difference in adjusted mean HAM-D scores at study end was 4.2 (95% CI=1.6, 6.9). Significantly more patients in the ECT plus medication group were rated "not ill at all" on the CGI-S compared with the medication only group. There was no statistically significant difference between groups in MMSE score. CONCLUSIONS: Additional ECT after remission (here operationalized as four continuation ECT treatments followed by further ECT only as needed) was beneficial in sustaining mood improvement for most patients.

A high-efficiency superhydrophobic plasma separator.

To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 µL of plasma from 200 µL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method.

Evidence for Novel Pharmacological Sensitivities of Transient Receptor Potential (TRP) Channels in Schistosoma mansoni.

Schistosomiasis, caused by parasitic flatworms of the genus Schistosoma, is a neglected tropical disease affecting hundreds of millions globally. Praziquantel (PZQ), the only drug currently available for treatment and control, is largely ineffective against juvenile worms, and reports of PZQ resistance lend added urgency to the need for development of new therapeutics. Ion channels, which underlie electrical excitability in cells, are validated targets for many current anthelmintics. Transient receptor potential (TRP) channels are a large family of non-selective cation channels. TRP channels play key roles in sensory transduction and other critical functions, yet the properties of these channels have remained essentially unexplored in parasitic helminths. TRP channels fall into several (7-8) subfamilies, including TRPA and TRPV. Though schistosomes contain genes predicted to encode representatives of most of the TRP channel subfamilies, they do not appear to have genes for any TRPV channels. Nonetheless, we find that the TRPV1-selective activators capsaicin and resiniferatoxin (RTX) induce dramatic hyperactivity in adult worms; capsaicin also increases motility in schistosomula. SB 366719, a highly-selective TRPV1 antagonist, blocks the capsaicin-induced hyperactivity in adults. Mammalian TRPA1 is not activated by capsaicin, yet knockdown of the single predicted TRPA1-like gene (SmTRPA) in S. mansoni effectively abolishes capsaicin-induced responses in adult worms, suggesting that SmTRPA is required for capsaicin sensitivity in these parasites. Based on these results, we hypothesize that some schistosome TRP channels have novel pharmacological sensitivities that can be targeted to disrupt normal parasite neuromuscular function. These results also have implications for understanding the phylogeny of metazoan TRP channels and may help identify novel targets for new or repurposed therapeutics.

Molecular Detection of Schistosome Infections with a Disposable Microfluidic Cassette.

Parasitic helminths such as schistosomes, as well as filarial and soil-transmitted nematodes, are estimated to infect at least a billion people worldwide, with devastating impacts on human health and economic development. Diagnosis and monitoring of infection dynamics and efficacy of treatment depend almost entirely on methods that are inaccurate, labor-intensive, and unreliable. These shortcomings are amplified and take on added significance in mass drug administration programs, where measures of effectiveness depend on accurate monitoring of treatment success (or failure), changes in disease transmission rates, and emergence of possible drug resistance. Here, we adapt isothermal molecular assays such as loop-mediated isothermal amplification (LAMP) to a simple, hand-held, custom-made field-ready microfluidic device that allows sensitive and specific detection of schistosome cell-free nucleic acids in serum and plasma (separated with a point-of-care plasma separator) from Schistosoma mansoni-infected mice. Cell-free S. mansoni DNA was detected with our device without prior extraction from blood. Our chip exhibits high sensitivity (~2 x 10(-17) g/µL), with a positive signal for S. mansoni DNA detectable as early as one week post infection, several weeks before parasite egg production commences. These results indicate that incorporation of isothermal amplification strategies with our chips could represent a strategy for rapid, simple, low-cost diagnosis of both pre-patent and chronic schistosome infections as well as potential monitoring of treatment efficacy.