RESUMEN
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.
Asunto(s)
Trastorno Depresivo Mayor , Terapia Electroconvulsiva , Anciano , Trastorno Depresivo Mayor/psicología , Terapia Electroconvulsiva/efectos adversos , Humanos , Litio , Persona de Mediana Edad , Resultado del Tratamiento , Clorhidrato de Venlafaxina/uso terapéuticoRESUMEN
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.
Asunto(s)
Antihelmínticos , Myxoma virus , Virus Oncolíticos , Esquistosomiasis mansoni , Animales , Antihelmínticos/farmacología , Femenino , Humanos , Masculino , Mamíferos , Praziquantel/farmacología , Schistosoma mansoni , Esquistosomiasis mansoni/tratamiento farmacológicoRESUMEN
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.
Asunto(s)
Trastorno Depresivo Mayor/tratamiento farmacológico , Terapia Electroconvulsiva , Trastornos Neurocognitivos/epidemiología , Clorhidrato de Venlafaxina/efectos adversos , Anciano , Terapia Combinada/efectos adversos , Trastorno Depresivo Mayor/terapia , Femenino , Humanos , Masculino , Trastornos Neurocognitivos/inducido químicamente , Pruebas Neuropsicológicas , Resultado del Tratamiento , Clorhidrato de Venlafaxina/uso terapéuticoRESUMEN
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.
Asunto(s)
Técnicas Analíticas Microfluídicas , Reacción en Cadena de la Polimerasa Multiplex , Técnicas de Amplificación de Ácido Nucleico , Sistemas de Atención de Punto , Temperatura , HumanosRESUMEN
Schistosomes are parasitic flatworms that cause schistosomiasis, a neglected tropical disease that affects hundreds of millions worldwide. Treatment and control of schistosomiasis relies almost entirely on the single drug praziquantel (PZQ), making the prospect of emerging drug resistance particularly worrisome. This review will survey reports of PZQ (and other drug) resistance in schistosomes and other platyhelminths, and explore mechanisms by which drug resistance might develop. Newer genomic and post-genomic strategies that offer the promise of better understanding of how drug resistance might arise in these organisms will be discussed. These approaches could also lead to insights into the mode of action of these drugs and potentially provide markers for monitoring the emergence of resistance.
Asunto(s)
Resistencia a Medicamentos/genética , Praziquantel/farmacología , Schistosoma/genética , Esquistosomiasis/parasitología , Esquistosomicidas/farmacología , Transportadoras de Casetes de Unión a ATP/genética , Animales , Mapeo Cromosómico , Genómica , Proteínas del Helminto/genética , Humanos , Enfermedades Desatendidas/parasitología , Interferencia de ARN , Schistosoma/efectos de los fármacosRESUMEN
Schistosomes are the causative agents of schistosomiasis, a neglected tropical disease affecting hundreds of millions worldwide and a major global health burden. Current control of schistosomiasis depends largely on a single drug, praziquantel (PZQ). One potential physiological target for new antischistosomal drugs is the parasite's excretory system, which removes wastes and xenobiotics. Multidrug resistance (MDR) transporters that are members of the ATP-binding cassette (ABC) superfamily of proteins are ATP-dependent efflux pumps involved in removal of toxins and xenobiotics from cells. They mediate the phenomenon of multidrug resistance, in which cells resistant to one drug show cross-resistance to a broad range of other agents, and are also associated with reduced drug susceptibility in parasitic helminths. In this review, we survey the different types of ABC transporter genes present within the schistosome genome, and examine recent evidence indicating that at least some of these transporters may play a role in fine-tuning susceptibility of schistosomes to PZQ. Disruption of their function may therefore provide a strategy for enhancing drug action or overcoming or attenuating drug resistance. Furthermore, dissection of the roles these transporters may play in normal schistosome physiology could potentially lead to identification of highly "druggable" targets for new antischistosomals.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/fisiología , Antihelmínticos/farmacología , Resistencia a Múltiples Medicamentos/fisiología , Schistosoma/efectos de los fármacos , Transportadoras de Casetes de Unión a ATP/genética , Animales , Resistencia a Múltiples Medicamentos/genética , Genes MDR , Humanos , Praziquantel/farmacología , Schistosoma/genética , Schistosoma/fisiología , Toxinas Biológicas/metabolismo , Xenobióticos/metabolismoRESUMEN
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.
Asunto(s)
Antihelmínticos , Esquistosomiasis mansoni , Canales de Potencial de Receptor Transitorio , Animales , Antihelmínticos/metabolismo , Antihelmínticos/farmacología , Antihelmínticos/uso terapéutico , Endosomas/metabolismo , Praziquantel/metabolismo , Praziquantel/farmacología , Praziquantel/uso terapéutico , Schistosoma mansoni/metabolismo , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomiasis mansoni/metabolismo , Canales de Potencial de Receptor Transitorio/genética , Canales de Potencial de Receptor Transitorio/metabolismoRESUMEN
The ß subunit of high voltage-activated Ca(2+) (Ca(v)) channels targets the pore-forming α(1) subunit to the plasma membrane and tunes the biophysical phenotype of the Ca(v) channel complex. We used a combination of molecular biology and whole-cell patch clamp to investigate the functional role of a long N-terminal polyacidic motif (NPAM) in a Ca(v)ß subunit of the human parasite Schistosoma mansoni (ß(Sm)), a motif that does not occur in other known Ca(v)ß subunits. When expressed in human embryonic kidney cells stably expressing Ca(v)2.3, ß(Sm) accelerates Ca(2+)/calmodulin-independent inactivation of Ca(v)2.3. Deleting the first 44 amino acids of ß(Sm), a region that includes NPAM, significantly slows the predominant time constant of inactivation (τ(fast)) under conditions that prevent Ca(2+)/CaM-dependent inactivation (ß(Sm): τ(fast) = 66 ms; ß(SmΔ2-44): τ(fast) = 111 ms, p < 0.01). Interestingly, deleting the amino acids that are N-terminal to NPAM (2-24 or 2-17) results in faster inactivation than with an intact N terminus (τ(fast) = 42 ms with ß(SmΔ2-17); τ(fast) = 40 ms with ß(SmΔ2-24), p < 0.01). This suggests that NPAM is the structural determinant for accelerating Ca(2+)/calmodulin-independent inactivation. We also created three chimeric subunits that contain the first 44 amino acids of ß(Sm) attached to mammalian ß(1b), ß(2a), and ß(3) subunits. For any given mammalian ß subunit, inactivation was faster if it contained the N terminus of ß(Sm) than if it did not. Co-expression of the mammalian α(2)δ-1 subunit resulted in doubling of the inactivation rate, but the effects of NPAM persisted. Thus, it appears that the schistosome Ca(v) channel complex has acquired a new function that likely contributes to reducing the amount of Ca(2+) that enters the cells in vivo. This feature is of potential interest as a target for new antihelminthics.
Asunto(s)
Canales de Calcio/fisiología , Proteínas del Helminto/fisiología , Activación del Canal Iónico/fisiología , Schistosoma mansoni/metabolismo , Secuencia de Aminoácidos , Animales , Western Blotting , Calcio/metabolismo , Canales de Calcio/química , Canales de Calcio/genética , Canales de Calcio Tipo R/genética , Canales de Calcio Tipo R/metabolismo , Canales de Calcio Tipo R/fisiología , Calmodulina/metabolismo , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Proteínas de Transporte de Catión/fisiología , Quelantes/farmacología , Ácido Egtácico/farmacología , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Proteínas del Helminto/genética , Proteínas del Helminto/metabolismo , Humanos , Activación del Canal Iónico/genética , Cinética , Potenciales de la Membrana/efectos de los fármacos , Microscopía Confocal , Modelos Biológicos , Datos de Secuencia Molecular , Mutación , Técnicas de Placa-Clamp , Subunidades de Proteína/genética , Subunidades de Proteína/fisiología , Schistosoma mansoni/genética , TransfecciónRESUMEN
P-glycoprotein (Pgp) is an ATP-dependent efflux pump involved in transport of xenobiotics from cells that, when overexpressed, can mediate multidrug resistance in mammalian cells. Pgp may be a candidate target for new anthelmintics, as it plays critical roles in normal cell physiology, in removal of drugs from cells, and potentially in the development of drug resistance. Schistosomes are parasitic flatworms that cause schistosomiasis, which affects hundreds of millions of people worldwide. Here, we express SMDR2, a Pgp homologue from Schistosoma mansoni (Platyhelminthes), in Chinese hamster ovary (CHO) cells and use fluorescence-based assays to examine the functional and pharmacological properties of this transporter. Membrane vesicles from stably transfected CHO cells expressing recombinant SMDR2 show significant increases in rhodamine transport and ATP hydrolysis compared with those from control cells or cells transfected with empty vector. SMDR2-mediated transport is inhibited by the Pgp modulators verapamil (IC(50)=12.1 muM) and nifedipine, and also by praziquantel, the current drug of choice against schisotosomiasis (IC(50)=17.4 muM). Efflux measurements of a fluorescent analog of praziquantel indicate that it is also a substrate for SMDR2. The interaction of praziquantel with SMDR2 may offer new strategies for potentiating the action of praziquantel and possibly overcoming drug resistance.
Asunto(s)
Subfamilia B de Transportador de Casetes de Unión a ATP/efectos de los fármacos , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , Proteínas del Helminto/efectos de los fármacos , Proteínas del Helminto/metabolismo , Praziquantel/farmacología , Schistosoma mansoni/efectos de los fármacos , Schistosoma mansoni/metabolismo , Esquistosomicidas/farmacología , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Secuencia de Bases , Células CHO , Cricetinae , Cricetulus , Cartilla de ADN/genética , ADN de Helmintos/genética , Resistencia a Múltiples Medicamentos , Genes de Helminto , Proteínas del Helminto/genética , Proteínas Recombinantes/efectos de los fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Rodaminas/metabolismo , Schistosoma mansoni/genética , Transfección , Vanadatos/farmacología , Miembro 4 de la Subfamilia B de Casete de Unión a ATPRESUMEN
Estimated to affect nearly 300 million people worldwide, schistosomiasis is caused by parasitic flatworms of the genus Schistosoma. The major pathological consequences of chronic schistosomiasis are associated with soluble egg antigens (SEA) secreted from schistosome egg deposits in liver and other organs. The vigorous immune responses induced by egg antigens result in granuloma formation and other pathophysiological symptoms such as hepatosplenomegaly and anemia. Risk of anemia correlates with infection intensity and the level of host hemoglobin is inversely proportional to egg count. Schistosomiasis-associated anemia could be multifactorial, but the potential link and molecular underpinnings are unclear. Here, we evaluate whether S. mansoni SEA affects survival of mouse erythrocytes. Erythrocytes incubated with different concentrations of SEA were tested for various markers of erythrocyte cell death. Erythrocytes exposed to SEA exhibit elevated intracellular Ca(2+) levels as measured by Fluo-3 AM fluorescence in flow cytometry, and they also display concentration-dependent, Ca(2+)-dependent, and heat-sensitive increases in phosphatidyl serine exposure. Further, SEA-exposed erythrocytes show increased fluorescence using the in situ apoptosis marker CaspACE FITC, indicating the involvement of caspase-mediated cell deformation. Taken together, these results offer several lines of experimental evidence for SEA-induced erythrocyte cell death and may provide new insights into factors contributing to schistosomiasis-associated anemia.
Asunto(s)
Antígenos Helmínticos/toxicidad , Apoptosis , Eritrocitos/efectos de los fármacos , Schistosoma mansoni/inmunología , Compuestos de Anilina/química , Animales , Calcio/metabolismo , Eritrocitos/metabolismo , Citometría de Flujo , Colorantes Fluorescentes/química , Ratones , Óvulo/inmunología , Óvulo/metabolismo , Xantenos/químicaRESUMEN
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.
Asunto(s)
Schistosoma/fisiología , Canales de Potencial de Receptor Transitorio/fisiología , Animales , Antihelmínticos/farmacología , Genes de Helminto , Genoma de los Helmintos , Humanos , Canales Iónicos/efectos de los fármacos , Canales Iónicos/genética , Canales Iónicos/fisiología , Filogenia , Praziquantel/farmacología , Schistosoma/efectos de los fármacos , Schistosoma mansoni/efectos de los fármacos , Schistosoma mansoni/fisiología , Esquistosomiasis/tratamiento farmacológico , Canal Catiónico TRPA1/efectos de los fármacos , Canal Catiónico TRPA1/genética , Canal Catiónico TRPA1/fisiología , Canales Catiónicos TRPV/efectos de los fármacos , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/fisiología , Canales de Potencial de Receptor Transitorio/efectos de los fármacos , Canales de Potencial de Receptor Transitorio/genéticaRESUMEN
BACKGROUND: The function of voltage-gated calcium (Cav) channels greatly depends on coupling to cytoplasmic accessory beta subunits, which not only promote surface expression, but also modulate gating and kinetic properties of the alpha1 subunit. Schistosomes, parasitic platyhelminths that cause schistosomiasis, express two beta subunit subtypes: a structurally conventional beta subunit and a variant beta subunit with unusual functional properties. We have previously characterized the functional properties of the variant Cavbeta subunit. Here, we focus on the modulatory phenotype of the conventional Cavbeta subunit (SmCavbeta) using the human Cav2.3 channel as the substrate for SmCavbeta and the whole-cell patch-clamp technique. RESULTS: The conventional Schistosoma mansoni Cavbeta subunit markedly increases Cav2.3 currents, slows macroscopic inactivation and shifts steady state inactivation in the hyperpolarizing direction. However, currents produced by Cav2.3 in the presence of SmCavbeta run-down to approximately 75% of their initial amplitudes within two minutes of establishing the whole-cell configuration. This suppressive effect was independent of Ca2+, but dependent on intracellular Mg2+-ATP. Additional experiments revealed that SmCavbeta lends the Cav2.3/SmCavbeta complex sensitivity to Na+ ions. A mutant version of the Cavbeta subunit lacking the first forty-six amino acids, including a string of twenty-two acidic residues, no longer conferred sensitivity to intracellular Mg2+-ATP and Na+ ions, while continuing to show wild type modulation of current amplitude and inactivation of Cav2.3. CONCLUSION: The data presented in this article provide insights into novel mechanisms employed by platyhelminth Cavbeta subunits to modulate voltage-gated Ca2+ currents that indicate interactions between the Ca2+ channel complex and chelated forms of ATP as well as Na+ ions. These results have potentially important implications for understanding previously unknown mechanisms by which platyhelminths and perhaps other organisms modulate Ca2+ currents in excitable cells.
Asunto(s)
Adenosina Trifosfato/metabolismo , Canales de Calcio/metabolismo , Calcio/metabolismo , Activación del Canal Iónico/fisiología , Riñón/fisiología , Sodio/metabolismo , Animales , Línea Celular , Humanos , Potenciales de la Membrana/fisiología , Schistosoma mansoniRESUMEN
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.
Asunto(s)
Antihelmínticos/farmacología , Sistemas de Liberación de Medicamentos , Interacciones Huésped-Parásitos/efectos de los fármacos , Schistosoma/efectos de los fármacos , Canales de Potencial de Receptor Transitorio/efectos de los fármacos , Animales , Antihelmínticos/aislamiento & purificación , Antihelmínticos/uso terapéutico , Humanos , Ratones , Praziquantel/uso terapéutico , Esquistosomiasis/tratamiento farmacológico , Canal Catiónico TRPA1/efectos de los fármacos , Canales Catiónicos TRPV/efectos de los fármacosRESUMEN
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.
Asunto(s)
Antihelmínticos/administración & dosificación , Proteínas del Helminto/metabolismo , Schistosoma/efectos de los fármacos , Schistosoma/metabolismo , Esquistosomiasis/parasitología , Canal Catiónico TRPA1/metabolismo , Animales , Calcio/metabolismo , Capsaicina/administración & dosificación , Femenino , Proteínas del Helminto/antagonistas & inhibidores , Proteínas del Helminto/genética , Humanos , Masculino , Ratones , Schistosoma/genética , Esquistosomiasis/tratamiento farmacológico , Canal Catiónico TRPA1/antagonistas & inhibidores , Canal Catiónico TRPA1/genéticaRESUMEN
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.
Asunto(s)
Trastorno Depresivo Mayor , Terapia Electroconvulsiva/métodos , Trastornos del Inicio y del Mantenimiento del Sueño , Clorhidrato de Venlafaxina , Anciano , Antidepresivos/administración & dosificación , Antidepresivos/efectos adversos , Terapia Combinada/métodos , Trastorno Depresivo Mayor/complicaciones , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/psicología , Trastorno Depresivo Mayor/terapia , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Humanos , Masculino , Escalas de Valoración Psiquiátrica , Índice de Severidad de la Enfermedad , Trastornos del Inicio y del Mantenimiento del Sueño/diagnóstico , Trastornos del Inicio y del Mantenimiento del Sueño/etiología , Trastornos del Inicio y del Mantenimiento del Sueño/psicología , Trastornos del Inicio y del Mantenimiento del Sueño/terapia , Resultado del Tratamiento , Clorhidrato de Venlafaxina/administración & dosificación , Clorhidrato de Venlafaxina/efectos adversosRESUMEN
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.
Asunto(s)
Antidepresivos/farmacología , Trastorno Depresivo Mayor/terapia , Terapia Electroconvulsiva/métodos , Compuestos de Litio/farmacología , Evaluación de Resultado en la Atención de Salud , Calidad de Vida , Clorhidrato de Venlafaxina/farmacología , Anciano , Anciano de 80 o más Años , Terapia Combinada , Trastorno Depresivo Mayor/tratamiento farmacológico , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevención Secundaria/métodosRESUMEN
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.
Asunto(s)
Trastorno Depresivo/psicología , Trastorno Depresivo/terapia , Terapia Electroconvulsiva/métodos , Calidad de Vida , Anciano , Anciano de 80 o más Años , Cognición , Femenino , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Escalas de Valoración Psiquiátrica , Inducción de Remisión , Resultado del TratamientoRESUMEN
Voltage-gated calcium (Ca2+) channels provide the pathway for Ca2+ influxes that underlie Ca2+ -dependent responses in muscles, nerves and other excitable cells. They are also targets of a wide variety of drugs and toxins. Ca2+ channels are multisubunit protein complexes consisting of a pore-forming alpha(1) subunit and other modulatory subunits, including the beta subunit. Here, we review the structure and function of schistosome Ca2+ channel subunits, with particular emphasis on variant Ca2+ channel beta subunits (Ca(v)betavar) found in these parasites. In particular, we examine the role these beta subunits may play in the action of praziquantel, the current drug of choice against schistosomiasis. We also present evidence that Ca(v)betavar homologs are found in other praziquantel-sensitive platyhelminths such as the pork tapeworm, Taenia solium, and that these variant beta subunits may thus represent a platyhelminth-specific gene family.