Enhancing Medical Spanish Education and Proficiency to Bridge Healthcare Disparities: A Comprehensive Assessment and Call to Action.

This article highlights the critical importance of linguistic and cultural concordance in health care, particularly in addressing the shortage of proficient Spanish-speaking healthcare providers in California. It advocates for standardized curricula, qualified instructors, and mandatory medical Spanish courses while stressing the significance of interdisciplinary training that integrates language skills with clinical experience and acknowledges the interplay between language and culture in health care. The article calls for proactive efforts from medical schools, faculty, and healthcare providers, emphasizing standardized curricula, culturally sensitive training, and reliable assessment tools. Additionally, it underscores the need to enhance the representation of underrepresented minority healthcare providers to ensure equitable health care for linguistic minorities, emphasizing the shared responsibility of healthcare and education stakeholders.

κO-SrVIA Conopeptide, a Novel Inhibitor Peptide for Two Members of the Human EAG Potassium Channel Family.

The first conotoxin affecting the voltage-gated potassium channels of the EAG family was identified and characterized from the venom of the vermivorous species Conus spurius from the Gulf of Mexico. This conopeptide, initially named Cs68 and later designated κO-SrVIA, is extremely hydrophobic and comprises 31 amino acid residues, including six Cysteines in the framework VI/VII, and a free C-terminus. It inhibits the currents mediated by two human EAG subtypes, Kv10.1 (IC50 = 1.88 ± 1.08 µM) and Kv11.1 (IC50 = 2.44 ± 1.06 µM), and also the human subtype Kv1.6 (IC50 = 3.6 ± 1.04 µM). Despite its clear effects on potassium channels, it shares a high sequence identity with δ-like-AtVIA and δ-TsVIA. Also, κO-SrVIA is the third conopeptide from the venom of C. spurius with effects on potassium channels, and the seventh conotoxin that blocks Kv1.6 channels.

Accidental Extravasation of Mitomycin C into the Subcutaneous Tissue.

Introduction: Mitomycin C (MMC) is a common chemotherapeutic agent used to treat a variety of solid tumors. Cutaneous adverse events are rare, but MMC is a known vesicant reported to cause tissue necrosis and sloughing, erythema, and ulceration if incorrectly infused into the subcutaneous tissue. Definitive treatment of extravasation injuries due to MMC depends on the severity of the cutaneous manifestation, which includes stopping the infusion, removing the catheter, or possible debridement. Case Presentation: We present the case of a 70-year-old female with extensive soft-tissue injury secondary to extravasation of MMC that required hospital admission and surgical intervention to remove the implantable venous access device. Conclusion: Extravasation injuries caused by vesicant drugs, such as MMC, often present as local skin irritation and inflammation. MMC extravasation may present a wide range of skin and soft tissue manifestations, ranging from erythema to ulcerations to necrosis. This rare but potentially detrimental complication of chemotherapy infusions should be recognized in cancer patients.

Consultorio de Atención Inmediata como estrategia de gestión de calidad en el Servicio de Emergencia de un hospital de Lima, Perú

Objetivo: Determinar la eficacia de la implementación del Consultorio de Atención Inmediata como estrategia de gestión de calidad en el Servicio de Emergencia de un hospital público de Lima, Perú. Materiales y métodos: Estudio analítico, cuasi experimental de antes y después, con grupos diferentes, que se realizó en 338 usuarios externos atendidos en el Servicio de Emergencia del Hospital María Auxiliadora. Se evaluó el tiempo de espera antes y después de la implementación del Consultorio de Atención Inmediata, así como la satisfacción a través del cuestionario SERVQUAL modificado -validado y recomendado por el Ministerio de Salud (Minsa) y aplicado en el grupo de posimplementación-, además de su relación con el tiempo de espera obtenido. El análisis se realizó a través del software de IBM SPSS S25.0 mediante medidas de frecuencias y porcentajes, diferencia de medias en grupos distintos con el test de Levene y la medida no paramétrica del coeficiente de correlación de Spearman con un nivel de significancia p < 0,05. Resultados: Los resultados mostraron predominio del sexo femenino (60,95 %), en el rango de edad de 14 a 29 años (24,56 %), en la prioridad IV (67,16 %); el tiempo de espera para la atención tuvo una media de 17,70 previo a la implementación y una media de 4,27 posterior a esta, por lo tanto, hubo una diferencia significativa después de la estrategia de gestión (p < 0,00). La satisfacción del Consultorio de Atención Inmediata se obtuvo en el 56,21 % de los usuarios externos, con énfasis en la dimensión empatía (76,33 %) y capacidad de respuesta (69,23 %), mientras que la dimensión con menor satisfacción fue la fiabilidad (48,52 %), además de obtener una correlación significativa inversa entre el tiempo de espera y la satisfacción (p < 0,01 y rho: -0,39). Conclusiones: La implementación del Consultorio de Atención Inmediata en el Servicio de Emergencia fue eficaz; en consecuencia, el tiempo de espera disminuyó, lo cual, a su vez, generó satisfacción en el usuario externo.

Objective: To determine the effectiveness of the implementation of the Immediate Care Office as a quality management strategy at the Emergency Service of a public hospital in Lima, Peru. Materials and methods: An analytical, quasi-experimental, before-and-after study conducted with 338 outpatients from different groups treated at the Emergency Service of Hospital María Auxiliadora. Before and after the implementation of the Immediate Care Office, waiting time, satisfaction-assessed through the modified SERVQUAL questionnaire, which was validated and recommended by the Ministry of Health and administered to the postimplementation group-as well as the relationship between satisfaction and waiting time were evaluated. The analysis was performed using IBM SPSS statistics V25.0, frequencies and percentages, the mean difference of both groups obtained through the Levene's test, and the nonparametric measurement of the Spearman's correlation coefficient with a significance level of p < 0.05. Results: The results showed a predominance of the female sex (60.95 %), the 14-to-29-year age range (24.56 %) and the Emergency Severity Index level IV (67.16 %). The average waiting time accounted for 17.70 and 4.27 before and after the office implementation, respectively. Therefore, there was a significant difference after the management strategy (p < 0.00). Out of all outpatients, 56.21 % were satisfied with the implementation of the Immediate Care Office, mainly with the empathy (76.33 %) and responsiveness (69.23 %) dimensions, while reliability was the dimension with the lowest satisfaction score (48.52 %). Additionally, there was a significant inverse correlation between waiting time and satisfaction (p < 0.01 and rho: -0.39). Conclusions: The implementation of the Immediate Care Office at the Emergency Service was effective since it reduced the waiting time, which in turn brought satisfaction to the outpatients.

A comprehensive medical Spanish curriculum model: the Vida Medical Spanish Curriculum.

INTRODUCTION: Racial and language disparities in the United States healthcare system have long undermined the quality of care provided to minority patients. With the projected growth of the Hispanic population, there is an urgent need for medical schools to integrate high-quality medical Spanish and cultural competency content. We propose a comprehensive medical Spanish curriculum aligned with the preclinical curriculum as a solution to these issues. The primary goal of this study is to demonstrate the effectiveness of a clinically focused, culturally competent medical Spanish program and advocate for its widespread adoption in medical institutions nationwide. METHODS: The study utilized the Kirkpatrick Model to evaluate the success of the medical Spanish curriculum. A total of 111 medical students voluntarily enrolled in the medical Spanish course. Out of these students, 47 completed the final evaluation, which included a Spanish Objective Structured Clinical Examination and a 40-question Multiple-Choice Exam assessing the integration of Spanish language skills and cultural competency. Both assessment methods took place in clinical skills facilities. Descriptive statistics summarized exam results, and two-tailed t-tests compared mean exam scores between students of different proficiency levels. RESULTS AND DISCUSSION: Students achieved a mean score of over 80% on all components of the Spanish Objective Structured Clinical Examination and the Multiple-Choice Exam. Survey data suggest that students felt able to communicate in Spanish with patients after completing the course series. The study also provides a model for a medical Spanish curriculum that applies expert-recommended best practices to meet the needs of Hispanic patient populations. LIMITATIONS AND CONCLUSIONS: Students who sat for the OSCE and MCE were self-selected. Baseline data on student perceptions and Spanish competency are not sufficient for making comparisons.

Manejo de urgencias odontológicas en pacientes afiliados al Seguro Social Campesino El Porvenir, El Carmen, Ecuador

Introducción: las urgencias dentales que se presentan a diario en el campo odontológico son de suma importancia, de ahí que sea necesario saber manejarlas y así evitar consecuencias posteriores que pueden poner en riesgo la vida. Objetivo: diagnosticar cómo se manejan las urgencias odontológicas en el Instituto Ecuatoriano de Seguridad Social Campesino. Materiales y métodos: estudio descriptivo, cuantitativo y transversal, con una muestra de 60 usuarios. Se tomaron, además, criterios de inclusión y de exclusión. Se utilizaron como técnicas de recolección de datos encuestas estructuradas -basadas en los protocolos de odontología del Ministerio de Salud Pública (2014) y el protocolo de urgencias odontológica COVID (2020)-, las que indicaron el manejo de las urgencias en el área mencionada. Se evaluó el servicio mediante los porcentajes que se reflejaron en la encuesta sobre el manejo de urgencias y los tipos de patologías de mayor frecuencia. Resultados: el 82 % de los encuestados manifestó que recibió una atención inmediata a su urgencia dental. Un 95 % refirió que les dieron una atención adecuada según su urgencia de calidad. Además, se evaluaron los tipos de urgencias más frecuentes, destacando infección dental (50 %), caries profunda (20 %), extracción (15 %), fractura (8 %) y tercer molar impactado (2 %). Conclusiones: se concluye que en el Seguro Social Campesino El Porvenir destacó el buen manejo en las urgencias odontológicas. Esto se ve reflejado en la utilización de maniobras y protocolos que están determinados en el área de la odontología.

Introduction: dental urgencies that daily present in the odontological field are of great importance, so it is necessary to know how to manage them and that way to avoid posterior consequences that could put life at risk. Objective: to diagnose how to manage odontological urgencies in the Ecuadorian Institute of Rural Social Security Materials and methods: descriptive, quantitative, cross-sectional study, with a sample of 60 users. Inclusion and exclusion criteria were also taken in to account. Structured inquiries were used as data collection techniques-based on the odontological protocols of the Ministry of Public Health (2014) and the COVID odontological emergency protocol (2020)-, which indicate emergencies management in the mentioned field. The service was evaluated through the percentages reflected in the emergency management enquiry and the most frequent types of pathologies. Results: 82% of those surveyed stated that they received an immediate attention to their dental emergency. 95% said that they were given an adequate attention according to their quality emergency. Besides that, the most frequent emergency types were evaluated, highlighting dental infection (50%), deep caries (20%), extraction (15%), fracture (8%) and impacted third molar (2%). Conclusion: It is concluded that in the Rural Social Security El Porvenir, the good management of odontological urgencies stood out. This is reflected in the use of maneuvers and protocols that are determined in the area of dentistry.

Beta-KTx14.3, a scorpion toxin, blocks the human potassium channel KCNQ1.

Potassium channels play a key role in regulating many physiological processes, thus, alterations in their proper functioning can lead to the development of several diseases. Hence, the search for compounds capable of regulating the activity of these channels constitutes an intense field of investigation. Potassium scorpion toxins are grouped into six subfamilies (α, ß, γ, κ, δ, and λ). However, experimental structures and functional analyses of the long chain ß-KTx subfamily are lacking. In this study, we recombinantly produced the toxins TcoKIK and beta-KTx14.3 present in the venom of Tityus costatus and Lychas mucronatus scorpions, respectively. The 3D structures of these ß-KTx toxins were determined by nuclear magnetic resonance. In both toxins, the N-terminal region is unstructured, while the C-terminal possesses the classic CSα/ß motif. TcoKIK did not show any clear activity against frog Shaker and human KCNQ1 potassium channels; however, beta-KTx14.3 was able to block the KCNQ1 channel. The toxin-channel interaction mode was investigated using molecular dynamics simulations. The results showed that this toxin could form a stable network of polar-to-polar and hydrophobic interactions with KCNQ1, involving key conserved residues in both molecular partners. The discovery and characterization of a toxin capable of inhibiting KCNQ1 pave the way for the future development of novel drugs for the treatment of human diseases caused by the malfunction of this potassium channel. STATEMENT OF SIGNIFICANCE: Scorpion toxins have been shown to rarely block human KCNQ1 channels, which participate in the regulation of cardiac processes. In this study, we obtained recombinant beta-KTx14.3 and TcoKIK toxins and determined their 3D structures by nuclear magnetic resonance. Electrophysiological studies and molecular dynamics models were employed to examine the interactions between these two toxins and the human KCNQ1, which is the major driver channel of cardiac repolarization; beta-KTx14.3 was found to block effectively this channel. Our findings provide insights for the development of novel toxin-based drugs for the treatment of cardiac channelopathies involving KCNQ1-like channels.

A Case Study of the Impact of Language Concordance on Patient Care, Satisfaction, and Comfort with Sharing Sensitive Information During Medical Care.

Linguistic barriers continue to be a source of difficulty and inappropriate treatment in our healthcare system. Several studies have shown the importance of language concordance, which leads to increased trust and higher patient satisfaction. The aim of this is study is to determine patients' satisfaction and comfort levels with sharing sensitive information in Spanish with either the health care provider or an interpreter, respectively, and to compare the results to find out if there is an option that patients prefer. There were two different groups of participants in the study. The experimental group was directly seen by Spanish-speaking student doctors while the control group was seen by English-speaking student doctors that had the aid of an interpreter. Several questions were asked to participants via survey in order to measure their comfort levels during the encounter. The results of this study demonstrate that having Spanish-speaking healthcare providers providing health care to Hispanic patients can raise patients' comfort levels and satisfaction in contrast to having the aid of an interpreter. Providing second language training to student doctors can potentially improve patient care and reduce health inequities facing LEP patients. Given the small sample size of our study, future projects should expand the study to include more participants.

The T-1 conotoxin µ-SrVA from the worm hunting marine snail Conus spurius preferentially blocks the human NaV1.5 channel.

Conotoxin sr5a had previously been identified in the vermivorous cone snail Conus spurius. This conotoxin is a highly hydrophobic peptide, with the sequence IINWCCLIFYQCC, which has a cysteine pattern "CC-CC" belonging to the T-1 superfamily. It is well known that this superfamily binds to molecular targets such as calcium channels, G protein-coupled receptors (GPCR), and neuronal nicotinic acetylcholine receptors (nAChR) and exerts an effect mainly in the central nervous system. However, its effects on other molecular targets are not yet defined, suggesting the potential of newly relevant molecular interactions. To find and demonstrate a potential molecular target for conotoxin sr5a electrophysiological assays were performed on three subtypes of voltage-activated sodium channels (NaV1.5, NaV1.6, and NaV1.7) expressed in HEK-293 cells with three different concentrations of sr5a(200, 400, and 600 nM). 200 nM sr5a blocked currents mediated by NaV1.5 by 33%, NaV1.6 by 14%, and NaV1.7 by 7%. The current-voltage (I-V) relationships revealed that conotoxin sr5a exhibits a preferential activity on the NaV1.5 subtype; the activation of NaV1.5 conductance was not modified by the blocking effect of sr5a, but sr5a affected the voltage-dependence of inactivation of channels. Since peptide sr5a showed a specific activity for a sodium channel subtype, we can assign a pharmacological family and rename it as conotoxin µ-SrVA.

A Novel Dimeric Conotoxin, FrXXA, from the Vermivorous Cone Snail Conus fergusoni, of the Eastern Pacific, Inhibits Nicotinic Acetylcholine Receptors.

We isolated a new dimeric conotoxin with inhibitory activity against neuronal nicotinic acetylcholine receptors. Edman degradation and transcriptomic studies indicate a homodimeric conotoxin composed by two chains of 47 amino acid in length. It has the cysteine framework XX and 10 disulfide bonds. According to conotoxin nomenclature, it has been named as αD-FrXXA. The αD-FrXXA conotoxin inhibited the ACh-induced response on nAChR with a IC50 of 125 nM on hα7, 282 nM on hα3ß2, 607 nM on α4ß2, 351 nM on mouse adult muscle, and 447 nM on mouse fetal muscle. This is first toxin characterized from C. fergusoni and, at the same time, the second αD-conotoxin characterized from a species of the Eastern Pacific.

A short framework-III (mini-M-2) conotoxin from the venom of a vermivorous species, Conus archon, inhibits human neuronal nicotinic acetylcholine receptors.

The venoms of Conus snails contain neuroactive peptides named conotoxins (CTXs). Some CTXs are nicotinic acetylcholine receptor (nAChRs) antagonists. nAChRs modulate the release of neurotransmitters and are implicated in several pathophysiologies. One venom peptide from Conus archon, a vermivorous species from the Mexican Pacific, was purified by RP-HPLC and its activity on human α7, α3ß2, and α7ß2 nAChRs was assessed by the two-electrode voltage clamp technique. At 36.3 µM the purified peptide (F27-1, renamed tentatively ArchIIIA) slowly reversibly inhibited the ACh-induced response of the hα7 subtype by 44.52 ± 5.83%, while it had low or no significant effect on the response of the hα3ß2 and hα7ß2 subtypes; the EC50 of the inhibiting effect was 45.7 µM on the hα7 subtype. This peptide has 15 amino acid residues and a monoisotopic mass of 1654.6 Da (CCSALCSRYHCLPCC), with three disulfide bridges and a free C-terminus. This sequence with a CC-C-C-CC arrangement (framework III) belongs to the M superfamily of conotoxins, corresponding to the mini-M´s (M-1-M-3) conotoxins; due to its size and inter-Cys spacings it is an M-2 conotoxin. This toxin is a novel mini-M conotoxin affecting ligand-gated ion channels, like the maxi-M CTX ψ-conotoxins and α-MIIIJ conotoxin (nAChRs blockers). This peptide seems to be homologous to the reg3b conotoxin (from Conus regius) with an identity of 93.3%, differing only in the third residue in the sequence, serine for threonine, both uncharged polar residues. We obtained, in silico, a probable 3D structure, which is consistent with its effect on neuronal subtypes.

Monitoring Sexually Transmitted Infections in Cervicovaginal Exfoliative Samples in Mexican Women.

BACKGROUND: Globally, Sexually Transmitted Infections (STIs) are a major cause of morbidity in sexually active individuals, having complications in reproduction health and quality of life. In concordance with the Sustainable Development Goals (SDG), the study aimed to investigate the prevalence of Candida spp., Ureaplasma spp., Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, HSV, and Mycoplasma spp. from cervicovaginal samples and to correlate them with the gynecological history of the patients. METHODS: Our analytical, prospective, and cross-sectional study included 377 women who participated in a reproductive health campaign during 2015-2016. Anthropometric and gynecological variables were obtained. Cervicovaginal specimens were collected and analyzed with a multiplex in-house PCR to detect Candida spp., Ureaplasma spp., Trichomonas vaginalis, Neisseria gonorrhoeae, HSV, Mycoplasma spp., and Chlamydia trachomatis. RESULTS: The positive cases were 175/377 (46.4%) to at least one of the microorganisms. The most frequent pathogen detected in this population was Ureaplasma spp. (n = 111, 29.4%), followed by Mycoplasma spp. (n = 56, 14.9%) and Candida spp. (n = 47, 12.5%); 33.7% of the positive cases were single infections, whereas 12.7% had coinfection. The multiplex PCR assay was designed targeting nucleotide sequences. CONCLUSIONS: Our data demonstrated that monitoring STIs among asymptomatic patients will encourage target programs to be more precisely and effectively implemented, as well as make these programs more affordable, to benefit society by decreasing the prevalence of STIs.

Uso de dispositivos móviles por parte de lactantes y preescolares: una revisión sistemática / Use of mobile devices by infants and preschoolers: a systematic review

Este estudio tiene como objetivo el examinar la frecuencia con la que los niños de 1 a 5 años hacen uso de los nuevos dispositivos móviles y su relación con la salud. Se realizó una revisión sistemática, retrospectiva, en Pubmed y Scielo; de un total de 145 artículos recolectados se incluyeron 43, cuyos criterios de inclusión y exclusión fueron: publicación de 2008 a 2021, sin predilección por alguna metodología en específico, variables de estudio (salud física, psicológica y social), no estudios en animales, trabajos repetidos y sin relevancia para el estudio, la calidad de la evidencia fue analizada con relación al valor de p y el índice de confianza 95% para cada variable en cuestión. El uso de Dispositivos móviles >2hrs/día se asocia a riesgo de desarrollo de alteraciones a la salud de los niños de 1 a 5 años, se necesita una vigilancia proactiva de los tutores(AU)

This study aims to examine the frequency with which children between the ages of 1 and 5 make use of new mobile devices and their relationship to health. A retrospective systematic review was carried out in Pubmed and Scielo; Of a total of 145 articles collected, 43 were included, whose inclusion and exclusion criteria were: publication from 2008 to 2021, without predilection for any specific methodology, study variables (physical, psychological and social health), no studies in animals, Repeated works without relevance to the study, the quality of the evidence was analyzed in relation to the value of p and the 95% confidence index for each variable in question. The use of mobile devices> 2hrs/day is associated with the risk of development of alterations to the health of children aged 1 to 5 years, a proactive vigilance of the tutors is needed(AU)

Studies of Conorfamide-Sr3 on Human Voltage-Gated Kv1 Potassium Channel Subtypes.

Recently, Conorfamide-Sr3 (CNF-Sr3) was isolated from the venom of Conus spurius and was demonstrated to have an inhibitory concentration-dependent effect on the Shaker K+ channel. The voltage-gated potassium channels play critical functions on cellular signaling, from the regeneration of action potentials in neurons to the regulation of insulin secretion in pancreatic cells, among others. In mammals, there are at least 40 genes encoding voltage-gated K+ channels and the process of expression of some of them may include alternative splicing. Given the enormous variety of these channels and the proven use of conotoxins as tools to distinguish different ligand- and voltage-gated ion channels, in this work, we explored the possible effect of CNF-Sr3 on four human voltage-gated K+ channel subtypes homologous to the Shaker channel. CNF-Sr3 showed a 10 times higher affinity for the Kv1.6 subtype with respect to Kv1.3 (IC50 = 2.7 and 24 µM, respectively) and no significant effect on Kv1.4 and Kv1.5 at 10 µM. Thus, CNF-Sr3 might become a novel molecular probe to study diverse aspects of human Kv1.3 and Kv1.6 channels.

A turripeptide from Polystira nobilis venom inhibits human α3ß2 and α7 nicotinic acetylcholine receptors.

Almost all marine snails within superfamily Conoidea produce venoms containing numerous neuroactive peptides. Most toxins characterized from members of this superfamily are produced by species belonging to family Conidae. These toxins (conotoxins) affect diverse membrane proteins, such as voltage- and ligand-gated ion channels, including nicotinic acetylcholine receptors (nAChRs). Family Turridae has been considerably less studied than their Conidae counterpart and, therefore, turrid toxins (turritoxins) have just been barely described. Consequently, in this work the most prominent chromatographic (RP-HPLC) fractions from the East Pacific species Polystira nobilis venom duct extract were isolated. The biological activity of six selected fractions was assayed on human (h) α7 AChRs expressed in Xenopus laevis oocytes. One of these fractions, F21, inhibited the acetylcholine-elicited response by 62 ± 12%. Therefore, this fraction was further purified and the F21-2 peptide was obtained. This peptide (at 5.6 µM) strongly and irreversibly inhibited the acetylcholine-induced response on hα7 and hα3ß2 nAChRs, by 55 ± 4 and 91 ± 1%, respectively. Electrospray mass spectrometry indicates that the average molecular mass of this toxin is 12 358.80 Da. The affinity for hα3ß2 nAChRs is high (IC50 of 566.2 nM). A partial sequence without cysteines was obtained by automated Edman degradation: WFRSFKSYYGHHGSVYRPNEPNFRSFAS…; blastp search revealed that this sequence has low similarity to some non-Cys-containing turripeptides. This is the first report of a turritoxin from a species of the American Pacific and the second description of a turripeptide inhibiting nAChRs.

αD-Conotoxins in Species of the Eastern Pacific: The Case of Conus princeps from Mexico.

Conus snails produce venoms containing numerous peptides such as the α-conotoxins (α-CTXs), which are well-known nicotinic acetylcholine receptor (nAChR) antagonists. Thirty-eight chromatographic fractions from Conus princeps venom extract were isolated by RP-HPLC. The biological activities of 37 fractions (0.07 µg/µL) were assayed by two-electrode voltage clamp on human α7 nAChRs expressed in Xenopus laevis oocytes. Fractions F7 and F16 notably inhibited the response elicited by acetylcholine by 52.7 ± 15.2% and 59.6 ± 2.5%, respectively. Fraction F7 was purified, and an active peptide (F7-3) was isolated. Using a combination of Edman degradation, mass spectrometry, and RNASeq, we determined the sequence of peptide F7-3: AVKKTCIRSTOGSNWGRCCLTKMCHTLCCARSDCTCVYRSGKGHGCSCTS, with one hydroxyproline (O) and a free C-terminus. The average mass of this peptide, 10,735.54 Da, indicates that it is a homodimer of identical subunits, with 10 disulfide bonds in total. This peptide is clearly similar to αD-CTXs from species of the Indo-Pacific. Therefore, we called it αD-PiXXA. This toxin slowly and reversibly inhibited the ACh-induced response of the hα7 nAChR subtype, with an IC50 of 6.2 µM, and it does not affect the hα3ß2 subtype at 6.5 µM.

Short-chain consensus alpha-neurotoxin: a synthetic 60-mer peptide with generic traits and enhanced immunogenic properties.

The three-fingered toxin family and more precisely short-chain α-neurotoxins (also known as Type I α-neurotoxins) are crucial in defining the elapid envenomation process, but paradoxically, they are barely neutralized by current elapid snake antivenoms. This work has been focused on the primary structural identity among Type I neurotoxins in order to create a consensus short-chain α-neurotoxin with conserved characteristics. A multiple sequence alignment considering the twelve most toxic short-chain α-neurotoxins reported from the venoms of the elapid genera Acanthophis, Oxyuranus, Walterinnesia, Naja, Dendroaspis and Micrurus led us to propose a short-chain consensus α-neurotoxin, here named ScNtx. The synthetic ScNtx gene was de novo constructed and cloned into the expression vector pQE30 containing a 6His-Tag and an FXa proteolytic cleavage region. Escherichia coli Origami cells transfected with the pQE30/ScNtx vector expressed the recombinant consensus neurotoxin in a soluble form with a yield of 1.5 mg/L of culture medium. The 60-amino acid residue ScNtx contains canonical structural motifs similar to α-neurotoxins from African elapids and its LD50 of 3.8 µg/mice is similar to the most toxic short-chain α-neurotoxins reported from elapid venoms. Furthermore, ScNtx was also able to antagonize muscular, but not neuronal, nicotinic acetylcholine receptors (nAChR). Rabbits immunized with ScNtx were able to immune-recognize short-chain α-neurotoxins within whole elapid venoms. Type I neurotoxins are difficult to isolate and purify from natural sources; therefore, the heterologous expression of molecules such ScNtx, bearing crucial motifs and key amino acids, is a step forward to create common immunogens for developing cost-effective antivenoms with a wider spectrum of efficacy, quality and strong therapeutic value.

Successful refolding and NMR structure of rMagi3: A disulfide-rich insecticidal spider toxin.

The need for molecules with high specificity against noxious insects leads the search towards spider venoms that have evolved highly selective toxins for insect preys. In this respect, spiders as a highly diversified group of almost exclusive insect predators appear to possess infinite potential for the discovery of novel insect-selective toxins. In 2003, a group of toxins was isolated from the spider Macrothele gigas and the amino acid sequence was reported. We obtained, by molecular biology techniques in a heterologous system, one of these toxins. Purification process was optimized by chromatographic methods to determine the three-dimensional structure by nuclear magnetic resonance in solution, and, finally, their biological activity was tested. rMagi3 resulted to be a specific insect toxin with no effect on mice.