Dermonecrosis caused by a spitting cobra snakebite results from toxin potentiation and is prevented by the repurposed drug varespladib.

Snakebite envenoming is a neglected tropical disease that causes substantial mortality and morbidity globally. The venom of African spitting cobras often causes permanent injury via tissue-destructive dermonecrosis at the bite site, which is ineffectively treated by current antivenoms. To address this therapeutic gap, we identified the etiological venom toxins in Naja nigricollis venom responsible for causing local dermonecrosis. While cytotoxic three-finger toxins were primarily responsible for causing spitting cobra cytotoxicity in cultured keratinocytes, their potentiation by phospholipases A2 toxins was essential to cause dermonecrosis in vivo. This evidence of probable toxin synergism suggests that a single toxin-family inhibiting drug could prevent local envenoming. We show that local injection with the repurposed phospholipase A2-inhibiting drug varespladib significantly prevents local tissue damage caused by several spitting cobra venoms in murine models of envenoming. Our findings therefore provide a therapeutic strategy that may effectively prevent life-changing morbidity caused by snakebite in rural Africa.

Diagnostic and Prognostic Potential of Multiparametric Renal MRI in Kidney Transplant Patients.

BACKGROUND: Multiparametric MRI provides assessment of functional and structural parameters in kidney allografts. It offers a non-invasive alternative to the current reference standard of kidney biopsy. PURPOSE: To evaluate the diagnostic and prognostic utility of MRI parameters in the assessment of allograft function in the first 3-months post-transplantation. STUDY TYPE: Prospective. SUBJECTS: 32 transplant recipients (54 ± 17 years, 20 females), divided into two groups according to estimated glomerular filtration rate (eGFR) at 3-months post-transplantation: inferior graft function (IGF; eGFR<45 mL/min/1.73 m2 , n = 10) and superior graft function (SGF; eGFR ≥ 45 mL/min/1.73 m2 , n = 22). Further categorization was based on the need for hemodialysis (C1) and decrease in s-creatinine (C2) at 1-week post-transplantation: delayed-graft-function (DGF: n = 4 C1, n = 10 C2) and early graft-function (EGF: n = 28 C1, n = 22 C2). FIELD STRENGTH/SEQUENCE: 3-T, pseudo-continuous arterial spin labeling, T1-mapping, and diffusion-weighted imaging. ASSESSMENT: Multiparametric MRI was evaluated at 1-week in all patients and 3-months after transplantation in 28 patients. Renal blood flow (RBF), diffusion coefficients (ADC, ΔADC, D, ∆ $$ \Delta $$ D, D*, flowing fraction f), T1 and ∆ $$ \Delta $$ T1 were calculated in cortex and medulla. The diagnostic and prognostic value of these parameters, obtained at 3-months and 1-week post-transplantation, respectively, was evaluated in the cortex to discriminate between DGF and EGF, and between SGF and IGF. STATISTICAL TESTS: Logistic regression, receiver-operating-characteristics, area-under-the-curve (AUC), confidence intervals (CIs), analysis-of-variance, t-test, Wilcoxon-Mann-Whitney test, Fisher's exact test, Pearson's correlation. P-value<0.05 was considered significant. RESULTS: DGF patients exhibited significantly lower cortical RBF and f and higher D*. The diagnostic value of MRI for detecting DGF was excellent (AUC = 100%). Significant differences between patients with IGF and SGF were found in RBF, ∆T1 , and ∆D. Multiparametric MRI showed higher diagnostic (AUC = 95.32%; CI: 88%-100%) and prognostic (AUC = 97.47%, CI: 92%-100%) values for detecting IGF than eGFR (AUC = 89.50%, CI: 79%-100%). DATA CONCLUSION: Multiparametric MRI may show high diagnostic and prognostic value in transplanted patients, yielding better results compared to eGFR measurements. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

Skeletal muscle fiber hypercontraction induced by Bothrops asper myotoxic phospholipases A2 ex vivo does not involve a direct action on the contractile apparatus.

Myonecrosis is a frequent clinical manifestation of envenomings by Viperidae snakes, mainly caused by the toxic actions of secreted phospholipase A2 (sPLA2) enzymes and sPLA2-like homologs on skeletal muscle fibers. A hallmark of the necrotic process induced by these myotoxins is the rapid appearance of hypercontracted muscle fibers, attributed to the massive influx of Ca2+ resulting from cell membrane damage. However, the possibility of myotoxins having, in addition, a direct effect on the contractile machinery of skeletal muscle fibers when internalized has not been investigated. This question is here addressed by using an ex vivo model of single-skinned muscle fibers, which lack membranes but retain an intact contractile apparatus. Rabbit psoas skinned fibers were exposed to two types of myotoxins of Bothrops asper venom: Mt-I, a catalytically active Asp49 sPLA2 enzyme, and Mt-II, a Lys49 sPLA2-like protein devoid of phospholipolytic activity. Neither of these myotoxins affected the main parameters of force development in striated muscle sarcomeres of the skinned fibers. Moreover, no microscopical alterations were evidenced after their exposure to Mt-I or Mt-II. In contrast to the lack of effects on skinned muscle fibers, both myotoxins induced a strong hypercontraction in myotubes differentiated from murine C2C12 myoblasts, with drastic morphological alterations that reproduce those described in myonecrotic tissue in vivo. As neither Mt-I nor Mt-II showed direct effects upon the contractile apparatus of skinned fibers, it is concluded that the mechanism of hypercontraction triggered by both myotoxins in patients involves indirect effects, i.e., the large cytosolic Ca2+ increase after sarcolemma permeabilization.

Alterations of the skeletal muscle contractile apparatus in necrosis induced by myotoxic snake venom phospholipases A2: a mini-review.

Skeletal muscle necrosis is a common clinical manifestation of snakebite envenoming. The predominant myotoxic components in snake venoms are catalytically-active phospholipases A2 (PLA2) and PLA2 homologs devoid of enzymatic activity, which have been used as models to investigate various aspects of muscle degeneration. This review addresses the changes in the contractile apparatus of skeletal muscle induced by these toxins. Myotoxic components initially disrupt the integrity of sarcolemma, generating a calcium influx that causes various degenerative events, including hypercontraction of myofilaments. There is removal of specific sarcomeric proteins, owing to the hydrolytic action of muscle calpains and proteinases from invading inflammatory cells, causing an initial redistribution followed by widespread degradation of myofibrillar material. Experiments using skinned cardiomyocytes and skeletal muscle fibers show that these myotoxins do not directly affect the contractile apparatus, implying that hypercontraction is due to cytosolic calcium increase secondary to sarcolemmal damage. Such drastic hypercontraction may contribute to muscle damage by generating mechanical stress and further sarcolemmal damage.

Venomous animals in a changing world.

The climatic changes of the next decades will modify human and livestock interactions with venomous animals; Some venomous species will disappear in the coming decades; Other venomous species will shift their distributions or increase their geographic ranges invading new countries that may not have specific antivenoms.

Disseminated lomentosporiosis in a heart transplant recipient: Case report and review of the literature.

BACKGROUND: Lomentospora prolificans (formerly S prolificans) is a saprophyte fungi that causes opportunistic infections in solid organ transplant (SOT) recipients. Resulting disseminated infections are difficult to treat and have a high mortality. Indications for antifungal prophylaxis after heart transplantation (HT) include CMV disease, reoperation, renal replacement therapy, extracorporeal membrane oxygenation (ECMO), and high environmental exposure to Aspergillus spores. However, the risk of breakthrough infections, such as Lomentosporiosis, remains a cause of concern. METHODS: We report the clinical findings, microbiology, treatment and outcome of a disseminated Lomentosporiosis in a heart transplant recipient with ECMO and antifungal prophylaxis. RESULTS: A 25-year-old male with complex grown-up congenital heart disease (GUCHD) was admitted for HT. He presented severe post-surgical complications including acute kidney injury and right heart and respiratory failure requiring venoarterial-ECMO, continuous renal replacement therapy (CCRT) and later on (+14) a ventricular assist device (VAD). Ganciclovir, cotrimoxazole, and antifungal prophylaxis with anidulafungin at standard doses had been started on day + 3 post HT. The patient presented seizures (+4), pancytopenia with mild neutropenia (days + 6 to + 11), influenza B (+7), and bacteremic Pseudomonas aeruginosa ventilator associated pneumonia (VAP) (+10). On days + 14 to + 16 Lomentospora prolificans was recovered from blood cultures, broncho aspirate, catheter tip, and skin biopsy. Despite treatment with L-AMB, voriconazole and terbinafine the patients died on day 17 after HT. Necropsy revealed disseminated infection with fungal invasion in central nervous system, heart, lung, cutaneous, and subcutaneous tissue. Broth microdilution tests demonstrated resistance to all antifungals. CONCLUSIONS: Lomentosporiosis is a rare complication that may emerge as a breakthrough invasive fungal infection in heart transplant recipients on ECMO despite antifungal prophylaxis.

Deficient Skeletal Muscle Regeneration after Injury Induced by a Clostridium perfringens Strain Associated with Gas Gangrene.

Gas gangrene, or clostridial myonecrosis, is usually caused by Clostridium perfringens and may occur spontaneously in association with diabetes mellitus, peripheral vascular disease, or some malignancies but more often after contamination of a deep surgical or traumatic lesion. If not controlled, clostridial myonecrosis results in multiorgan failure, shock, and death, but very little is known about the muscle regeneration process that follows myonecrosis when the infection is controlled. In this study, we characterized the muscle regeneration process after myonecrosis caused in a murine experimental infection with a sublethal inoculum of C. perfringens vegetative cells. The results show that myonecrosis occurs concomitantly with significant vascular injury, which limits the migration of inflammatory cells. A significant increase in cytokines that promote inflammation explains the presence of an inflammatory infiltrate; however, impaired interferon gamma (IFN-γ) expression, a reduced number of M1 macrophages, deficient phagocytic activity, and a prolongation of the permanence of inflammatory cells lead to deficient muscle regeneration. The expression of transforming growth factor ß1 (TGF-ß1) agrees with the consequent accumulation of collagen in the muscle, i.e., fibrosis observed 30 days after infection. These results provide new information on the pathogenesis of gas gangrene caused by C. perfringens, shed light on the basis of the deficient muscle regenerative activity, and may open new perspectives for the development of novel therapies for patients suffering from this disease.

Site mutation of residues in a loop surrounding the active site of a PI snake venom metalloproteinase abrogates its hemorrhagic activity.

Abrogation of the hemorrhagic activity of BaP1, a PI Snake Venom Metalloproteinase (SVMP) from the venom of Bothrops asper, was achieved by the substitution of residues in the first part of the Ω loop surrounding the active site by the corresponding residues of a structurally-similar non-hemorrhagic PI SVMP from a related venom. Previous studies by molecular dynamic simulation showed higher flexibility in the first part of the loop in hemorrhagic SVMPs, as compared to non-hemorrhagic SVMPs. It has been suggested that the Ω loop is critical for protein-protein interface and may be involved in the interaction with extracellular matrix proteins, hence influencing the ability of the toxin to bind and hydrolyze basement membrane components. The SVMP with the site mutation completely lost hemorrhagic activity, and only had a partial reduction of proteolytic activity, indicating that this region in the loop plays a key role in the ability to induce hemorrhage. Our findings demonstrate a key structural determinant of the hemorrhagic capacity of PI SVMPs.

[Situation of public laboratories manufacturing antivenoms in Latin AmericaA situação dos laboratórios públicos produtores de soros antivenenos na América Latina]. / Situación de los laboratorios públicos productores de antivenenos en América Latina.

The situation of public laboratories manufacturing antivenoms in Latin America was analyzed, based on the results of a workshop coordinated by the Pan American Foot-and-Mouth Disease Center (PANAFTOSA) of the Pan American Health Organization (PAHO). Nine countries in the region have 12 public laboratories that produce and distribute antivenoms for use against different venomous animals. The situation of each laboratory was discussed, and an analysis was conducted of the current scenario, which is characterized by increasing regulatory requirements that vary in terms of infrastructure and production capacity. The authors identified a need to organize regional cooperation processes to improve the availability of antivenoms, including: research and development projects to improve processes and technologies; studies of the capacity of antivenoms to neutralize different poisons; and technical training programs for professionals and technical personnel. In the current context, in which the World Health Organization has prepared a global strategy for the prevention and control of snakebite envenoming, PANAFTOSA has taken on coordination of this initiative in the Americas. Improving the availability of antivenoms is the priority. As a result of the workshop, the RELAPA network was created, bringing together public laboratories that manufacture antivenoms in Latin America, in order to strengthen these laboratories and increase the availability of, and access to effective and safe antivenoms throughout Latin America.

A situação dos laboratórios públicos produtores de soros antivenenos na América Latina foi analisada com base nas conclusões de um seminário coordenado pelo Centro Pan-Americano de Febre Aftosa (PANAFTOSA) da Organização Pan-Americana da Saúde (OPAS). Em nove países da Região, encontram-se 12 laboratórios públicos que produzem e distribuem soros contra venenos de diferentes animais peçonhentos. Examinou-se a situação de cada laboratório, analisou-se o panorama atual marcado por crescentes demandas de regulação e pela heterogeneidade da infraestrutura e capacidade produtiva dos laboratórios e destacou-se a necessidade de um esforço concertado de cooperação regional com vistas a aumentar a disponibilidade de soros antivenenos, englobando projetos de pesquisa e desenvolvimento para o avanço dos processos e tecnologias, estudos do perfil da capacidade de neutralização dos soros contra diversos venenos e programas de capacitação técnica de profissionais e pessoal técnico. No contexto atual, em que uma estratégia mundial de prevenção e controle de acidentes ofídicos foi elaborada pela Organização Mundial da Saúde e que a coordenação das ações relacionadas na Região das Américas foi assumida pelo PANAFTOSA, melhorar a disponibilidade de soros antivenenos é prioridade. Como resultado deste seminário, a Rede de Laboratórios Públicos Produtores de Soros Antivenenos da América Latina (RELAPA) foi formada com o objetivo de fortalecer os laboratórios e aumentar a disponibilidade e a acessibilidade de soros antivenenos eficazes e seguros em toda América Latina.

A synthetic biology approach for consistent production of plant-made recombinant polyclonal antibodies against snake venom toxins.

Antivenoms developed from the plasma of hyperimmunized animals are the only effective treatment available against snakebite envenomation but shortage of supply contributes to the high morbidity and mortality toll of this tropical disease. We describe a synthetic biology approach to affordable and cost-effective antivenom production based on plant-made recombinant polyclonal antibodies (termed pluribodies). The strategy takes advantage of virus superinfection exclusion to induce the formation of somatic expression mosaics in agroinfiltrated plants, which enables the expression of complex antibody repertoires in a highly reproducible manner. Pluribodies developed using toxin-binding genetic information captured from peripheral blood lymphocytes of hyperimmunized camels recapitulated the overall binding activity of the immune response. Furthermore, an improved plant-made antivenom (plantivenom) was formulated using an in vitro selected pluribody against Bothrops asper snake venom toxins and has been shown to neutralize a wide range of toxin activities and provide protection against lethal venom doses in mice.

Metalloproteinases in disease: identification of biomarkers of tissue damage through proteomics.

INTRODUCTION: Metalloproteinases play key roles in health and disease, by generating novel proteoforms with variable structure and function. Areas covered: This review focuses on the role of endogenous [a Disintegrin and Metalloproteinase (ADAMs), ADAMs with thrombospondin motifs (ADAMTS), and matrix metalloproteinases (MMPs)] and exogenous metalloproteinases in various disease conditions, and describes the application of mass spectrometry-based proteomics to detect qualitative and quantitative changes in protein profiles in tissues and body fluids in disease. Emphasis is placed on the proteomic analysis of exudates collected from affected tissues, including methods that enrich newly generated protein fragments derived from proteolysis in cells, stroma, or extracellular matrix. The use of proteomic analysis of exudates in the study of the local tissue damage induced by metalloproteinases derived from viperid snake venoms is discussed, particularly in relation to extracellular matrix degradation and to the overall pathology of these envenomings. Expert commentary: The information provided by these proteomics approaches is paving the way for the identification of biomarkers based on particular proteolytic signatures associated with different pathologies. Together with other methodological approaches, a comprehensive view of the mechanisms and dynamics of diseases can be achieved. Such basis of knowledge allows for the design of novel diagnostic and therapeutic approaches within the frame of 'precision' or 'personalized' medicine.

A Snake Venom-Secreted Phospholipase A2 Induces Foam Cell Formation Depending on the Activation of Factors Involved in Lipid Homeostasis.

MT-III, a snake venom GIIA sPLA2, which shares structural and functional features with mammalian GIIA sPLA2s, activates macrophage defense functions including lipid droplet (LDs) formation, organelle involved in both lipid metabolism and inflammatory processes. Macrophages (MΦs) loaded with LDs, termed foam cells, characterize early blood vessel fatty-streak lesions during atherosclerosis. However, the factors involved in foam cell formation induced by a GIIA sPLA2 are still unknown. Here, we investigated the participation of lipid homeostasis-related factors in LD formation induced by MT-III in macrophages. We found that MT-III activated PPAR-γ and PPAR-ß/δ and increased the protein levels of both transcription factors and CD36 in macrophages. Pharmacological interventions evidenced that PPAR-γ, PPAR-ß/δ, and CD36 as well as the endoplasmic reticulum enzymes ACAT and DGAT are essential for LD formation. Moreover, PPAR-ß/δ, but not PPAR-γ, is involved in MT-III-induced PLIN2 protein expression, and both PPAR-ß/δ and PPAR-γ upregulated CD36 protein expression, which contributes to MT-III-induced COX-2 expression. Furthermore, production of 15-d-PGJ2, an activator of PPARs, induced by MT-III, was dependent on COX-1 being LDs an important platform for generation of this mediator.

Arterial spin labeling MRI is able to detect early hemodynamic changes in diabetic nephropathy.

PURPOSE: To investigate whether arterial spin labeling (ASL) MRI could detect renal hemodynamic impairment in diabetes mellitus (DM) along different stages of chronic kidney disease (CKD). MATERIALS AND METHODS: Three Tesla (3T) ASL-MRI was performed to evaluate renal blood flow (RBF) in 91 subjects (46 healthy volunteers and 45 type 2 diabetic patients). Patients were classified according to their estimated glomerular filtration rate (eGFR) as group I (eGFR > 60 mL/min/1.73 m2 ), group II (60 ≥ eGFR>30 mL/min/1.73 m2 ), or group III (eGFR ≤ 30 mL/min/1.73 m2 ), to determine differences depending on renal function. Studies were performed at 3T using a 12-channel flexible body array combined with the spine array coil as receiver. RESULTS: A 28% reduction in cortical RBF was seen in diabetics in comparison with healthy controls (185.79 [54.60] versus 258.83 [37.96] mL/min/100 g, P < 3 × 10-6 ). Differences were also seen between controls and diabetic patients despite normal eGFR and absence of overt albuminuria (RBF [mL/min/100 g]: controls=258.83 [37.96], group I=208.89 [58.83], P = 0.0018; eGFR [mL/min/1.73 m2 ]: controls = 95.50 [12.60], group I = 82.00 [20.76], P > 0.05; albumin-creatinine ratio [mg/g]: controls = 3.50 [4.45], group I = 17.50 [21.20], P > 0.05). A marked decrease in RBF was noted a long with progression of diabetic nephropathy (DN) through the five stages of CKD (χ2 = 43.58; P = 1.85 × 10-9 ). Strong correlation (r = 0.62; P = 4 × 10-10 ) was obtained between RBF and GFR estimated by cystatin C. CONCLUSION: ASL-MRI is able to quantify early renal perfusion impairment in DM, as well as changes according to different CKD stages of DN. In addition, we demonstrated a correlation of RBF quantified by ASL and GFR estimated by cystatin C. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1810-1817.

Discovery of small molecule inhibitors for the snake venom metalloprotease BaP1 using in silico and in vitro tests.

Snakebites represent an important public health problem, with a great number of victims with permanent sequelae or fatal outcomes, particularly in rural, agriculturally active areas. The snake venom metalloproteases (SVMPs) are the principal proteins responsible for some clinically-relevant effects, such as local and systemic hemorrhage, dermonecrosis, and myonecrosis. Because of the difficulties in neutralizing them rapidly and locally by antivenoms, the search and design of small molecules as inhibitors of SVMPs are proposed. The Bothrops asper metalloprotease P1 (BaP1) is hereby used as a target protein and by High Throughput Virtual Screening (HTVS) approach, the free access virtual libraries: ZINC, PubChem and ChEMBL, were searched for potent small molecule inhibitors. Results from the aforementioned approaches provided strong evidences on the structural requirements for the efficient BaP1 inhibition such as the presence of the pyrimidine-2,4,6-trione moiety. The two proposed compounds have also shown excellent results in performed in vitro interaction studies against BaP1.

Preclinical efficacy against toxic activities of medically relevant Bothrops sp. (Serpentes: Viperidae) snake venoms by a polyspecific antivenom produced in Mexico.

The assessment of the preclinical neutralizing ability of antivenoms in Latin America is necessary to determine their scope of efficacy. This study was aimed at analyzing the neutralizing efficacy of a polyspecific bothropic-crotalic antivenom manufactured by BIRMEX in Mexico against lethal, hemorrhagic, defibrinogenating and in vitro coagulant activities of the venoms of Bothrops jararaca (Brazil), B. atrox (Perú and Colombia), B. diporus (Argentina), B. mattogrossensis (Bolivia), and B. asper (Costa Rica). Standard laboratory tests to determine these activities were used. In agreement with previous studies with bothropic antivenoms in Latin America, a pattern of cross-neutralization of heterologous venoms was observed. However, the antivenom had low neutralizing potency against defibrinogenating effect of the venoms of B. atrox (Colombia) and B. asper (Costa Rica), and failed to neutralize the in vitro coagulant activity of the venom of B. asper (Costa Rica) at the highest antivenom/venom ratio tested. It is concluded that, with the exception of coagulant and defibrinogenating activities of B. asper (Costa Rica) venom, this antivenom neutralizes toxic effects of various Bothrops sp venoms. Future studies are necessary to assess the efficacy of this antivenom against other viperid venoms.

Purification of equine whole IgG snake antivenom by using an aqueous two phase system as a primary purification step.

There is a need to introduce innovations in the manufacture of snake antivenoms to increase the supply of these products worldwide. In this work, the fractionation of equine hyperimmune plasma with a new methodology that includes an aqueous two phase system (ATPS) as a primary purification step was compared with the traditional method of caprylic acid precipitation. Hyperimmune plasma from horses immunized with the venoms of three snakes from sub-Saharan Africa was used as starting material for the production of both formulations. After being adjusted to the same lethal neutralizing activity, both antivenoms were compared in terms of their immunoreactivity, neutralization of in vitro venom activities, physicochemical characteristics, and stability. Their performance in terms of yield and purity was also assessed. The neutralization profile of in vitro enzymatic activities and the immunoreactivity, analyzed by ELISA and antivenomic approaches, were very similar for both preparations. Likewise, they behaved similarly in stability studies. However, ATPS-fractionated antivenom showed improved physicochemical profile and immunochemical purity and yield, mainly owing to its lower protein content. Additionally, this methodology allowed the recovery of albumin as a byproduct. ATPS purification constitutes a promising technology for antivenom production and should be further evaluated at preclinical and clinical levels.

A multicomponent strategy to improve the availability of antivenom for treating snakebite envenoming.

Snakebite envenoming is a common but neglected public health problem, particularly in impoverished rural regions of sub-Saharan Africa, Asia and Latin America. The only validated treatment for this condition is passive immunotherapy with safe and effective animal-derived antivenoms. However, there is a long-lasting crisis in the availability of these life-saving medications, particularly in sub-Saharan Africa and parts of Asia. We herein advocate a multicomponent strategy to substantially improve the availability of safe and effective antivenoms at the global level. This strategy is based on: (i) preparing validated collections of representative venom pools from the most medically dangerous snakes in high-risk regions of the world; (ii) strengthening the capacity of national antivenom manufacturing and quality control laboratories and their regulatory authorities and establishing new facilities in developing countries through technology transfer, as an integral part of efforts to develop their biological products industry; (iii) getting established laboratories to generate antivenoms for various regions of the world; and (iv) getting governments and relevant organizations to give snakebite envenoming due recognition within national and international public health policy frameworks. These ways of making antivenom available should be complemented by actions to improve health information systems, the accessibility of antivenoms, the training of medical and nursing staff, and community-based education. Such a multicomponent strategy involving stakeholders on many levels could help consolidate sustainable improvements in antivenom availability worldwide.

L'envenimation par morsure de serpent est un problème de santé publique fréquent, mais négligé, en particulier dans les régions rurales pauvres de l'Afrique subsaharienne, de l'Asie et de l'Amérique latine. Le seul traitement validé pour soigner cet état est l'immunothérapie passive avec des sérums antivenimeux d'origine animale sûrs et efficaces. Cependant, une crise durable limite actuellement la disponibilité de ces médicaments vitaux, surtout en Afrique subsaharienne et dans certaines parties de l'Asie. Nous préconisons ici une stratégie à composants multiples pour améliorer considérablement la disponibilité des sérums antivenimeux sûrs et efficaces à l'échelle mondiale. Cette stratégie repose sur: (i) la préparation de collections validées de groupes représentatifs de venins prélevés sur les serpents les plus dangereux sur le plan médical dans les régions à haut risque du monde; (ii) le renforcement de la capacité de production nationale des sérums antivenimeux, des laboratoires de contrôle qualité et de leurs organismes de réglementation, et la création de nouvelles installations dans les pays en développement par transfert de technologies, en tant que partie intégrante de la stratégie de développement de leur industrie de produits biologiques; (iii) la production par les laboratoires déjà établis de sérums antivenimeux pour les différentes régions du monde; et (iv) la reconnaissance officielle par les gouvernements et les organisations compétentes de l'envenimation par morsure de serpent dans le cadre des politiques de santé publique nationales et internationales. Ces façons de rendre disponibles les sérums antivenimeux devraient être complétées par des actions visant à améliorer les systèmes d'informations sanitaires, l'accessibilité des sérums antivenimeux, la formation du personnel médical et infirmier et les programmes communautaires d'éducation. Une telle stratégie à composants multiples impliquant des acteurs à différents niveaux pourrait contribuer à consolider les améliorations durables en matière de disponibilité des sérums antivenimeux dans le monde entier.

El envenenamiento por mordedura de serpiente es un problema de salud pública común pero desatendido, especialmente en las regiones rurales más pobres de África subsahariana, Asia y América Latina. El único tratamiento reconocido contra estas mordeduras es la inmunoterapia pasiva con sueros antiofídicos de origen animal seguros y eficaces. Sin embargo, la disponibilidad de estos medicamentos esenciales para salvar vidas lleva mucho tiempo en crisis, en particular en África subsahariana y en algunas zonas de Asia. En el presente documento, abogamos por una estrategia multicomponente para mejorar de forma sustancial la disponibilidad de sueros antiofídicos seguros y eficaces en todo el mundo. La estrategia se basa en: (i) preparar colecciones reconocidas de sueros antiofídicos representativos de las serpientes más peligrosas en zonas de alto riesgo del mundo; (ii) reforzar la capacidad nacional de producción de sueros antiofídicos y la calidad de los laboratorios de control y sus autoridades normativas, así como crear instalaciones nuevas en los países en desarrollo por medio de la transferencia de tecnología como parte integral de los esfuerzos por desarrollar su industria de productos biológicos; (iii) conseguir que los laboratorios consolidados fabriquen sueros antiofídicos para varias regiones del mundo; y (iv) conseguir que los gobiernos y las organizaciones pertinentes otorguen al envenenamiento por mordedura de serpiente el reconocimiento debido dentro del marco de las políticas nacionales e internacionales de salud pública. Estas tareas dirigidas a facilitar el suero antiofídico deben complementarse con acciones para mejorar los sistemas de información sobre la salud, la accesibilidad de los antiofídicos, la formación del personal médico y de enfermería, y la educación comunitaria. Una estrategia multicomponente de ese tipo, que incluye a los interesados a varios niveles, podría ayudar a consolidar mejoras sostenibles en la disponibilidad de antiofídicos en todo el mundo.

Physical activity program for patients with dementia and their relative caregivers: randomized clinical trial in Primary Health Care (AFISDEMyF study).

BACKGROUND: The aging of the population has led to the increase of chronic diseases, especially dementia and cardiovascular diseases, and it has become necessary for their relatives to dedicate more time in caregiving.The objective in the first phase of this study is to evaluate the effectiveness of a Primary Health Care procedure to increase the physical activity of people with dementia and their relative caregivers. Also the effect on the cognitive state and cardiovascular risk will be assessed. DESIGN: Clinical, multicentric and randomized trial. A simple random sampling to select 134 patients diagnosed with dementia will be carried out. After contacting their relatives, his/her participation in the trial will be requested. A basal assessment will be made and the participants will be asigned to control or intervention group (1:1). VARIABLES: The main measure will be the assessment of physical activity (podometer and 7-PAR) in patients and caregivers. In patients with dementia: ADAS-cog, functional degree and cardiovascular risk. In caregivers: cardiovascular risk, general health and quality of life. INTERVENTION: For 3 months, participants will receive instructions to do physical activity with an adapted program. This program will be designed and applied by Primary Health Care professionals in patients with dementia and their caregivers. The control group will receive regular care. ANALYSIS: An intention-to-treat analysis will be carried out by comparing the observed differences between basal, 6 and 12 months measures. Change in the mean of daily steps assessed with the podometer and 7-PAR will be the main result. DISCUSSION: If the main hypothesis is confirmed, it could be useful to improve the cognitive state of patients with dementia, as well as the cardiovascular risk of all of them. The results can be good to improve technical features of the devices that register the physical activity in the patients with dementia, and it could facilitate its commercialization. TRIAL REGISTRATION: Clinical Trials.gov Identifier: NCT02044887.

An Asp49 phospholipase A2 from snake venom induces cyclooxygenase-2 expression and prostaglandin E2 production via activation of NF-κB, p38MAPK, and PKC in macrophages.

Phospholipases A2 (PLA2) are key enzymes for production of lipid mediators. We previously demonstrated that a snake venom sPLA2 named MT-III leads to prostaglandin (PG)E2 biosynthesis in macrophages by inducing the expression of cyclooxygenase-2 (COX-2). Herein, we explored the molecular mechanisms and signaling pathways leading to these MT-III-induced effects. Results demonstrated that MT-III induced activation of the transcription factor NF-κB in isolated macrophages. By using NF-κB selective inhibitors, the involvement of this factor in MT-III-induced COX-2 expression and PGE2 production was demonstrated. Moreover, MT-III-induced COX-2 protein expression and PGE2 release were attenuated by pretreatment of macrophages with SB202190, and Ly294002, and H-7-dihydro compounds, indicating the involvement of p38MAPK, PI3K, and PKC pathways, respectively. Consistent with this, MT-III triggered early phosphorylation of p38MAPK, PI3K, and PKC. Furthermore, SB202190, H-7-dihydro, but not Ly294002 treatment, abrogated activation of NF-κB induced by MT-III. Altogether, these results show for the first time that the induction of COX-2 protein expression and PGE2 release, which occur via NF-κB activation induced by the sPLA2-MT-III in macrophages, are modulated by p38MAPK and PKC, but not by PI3K signaling proteins.