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1.
BMC Health Serv Res ; 23(1): 644, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37328840

RESUMO

BACKGROUND: The government of Ethiopia has envisioned digitalizing primary healthcare units through the electronic community health information system (eCHIS) program as a re-engineering strategy aiming to improve healthcare data quality, use, and service provision. The eCHIS is intended as a community-wide initiative to integrate lower health structure with higher administrative health and service delivery unit with the ultimate goal of improving community health. However, the success or failure of the program depends on the level of identifying enablers and barriers of the implementation. Therefore, this study aimed to explore individual and contextual-level enablers and barriers determining eCHIS implementation. METHOD: We conducted an exploratory study to determine the enablers and barriers to successfully implementing eCHIS in rural Wogera district, northwest Ethiopia. In-depth interviews and key informant interviews were applied at participants from multiple sites. A thematic content analysis was conducted based on the key themes reported. We applied the five components of consolidated framework for implementation research to interpret the findings. RESULTS: First, based on the intervention's characteristics, implementers valued the eCHIS program. However, its implementation was impacted by the heavy workload, limited or absent network and electricity. Outer-setting challenges were staff turnover, presence of competing projects, and lack of incentive mechanisms. In terms of the inner setting, lack of institutionalization and ownership were mentioned as barriers to the implementation. Resource allocation, community mobilization, leaders' engagement, and availability of help desk need emphasis for a better achievement. With regard to characteristics of the individuals, limited digital literacy, older age, lack of peer-to-peer support, and limited self-expectancy posed challenges to the implementation. Finally, the importance of mentoring and engaging community and religious leaders, volunteers, having defined plan and regular meetings were identified elements of the implementation process and need emphasis. CONCLUSION: The findings underlined the potential enablers and barriers of eCHIS program for quality health data generation, use, and service provision and highlighted areas that require emphasis for further scale-up. The success and sustainability of the eCHIS require ongoing government commitment, sufficient resource allocation, institutionalization, capacity building, communication, planning, monitoring, and evaluation.


Assuntos
Sistemas de Informação em Saúde , Humanos , Etiópia , Atenção à Saúde , Grupos Focais , Aconselhamento , Pesquisa Qualitativa
2.
J Proteome Res ; 20(1): 895-908, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33225711

RESUMO

Saw-scaled or carpet vipers (genus Echis) are considered to cause a higher global snakebite mortality than any other snake. Echis carinatus sochureki (ECS) is a widely distributed snake species, also found across the thirteen provinces of Iran, where it is assumed to be responsible for the most snakebite envenomings. Here, we collected the Iranian specimens of ECS from three different geographically distinct populations, investigated food habits, and performed toxicity assessment and venom proteome profiling to better understand saw-scaled viper life. Our results show that the prey items most commonly found in all populations were arthropods, with scorpions from the family Buthidae particularly well represented. LD50 (median lethal dose) values of the crude venom demonstrate highly comparable venom toxicities in mammals. Consistent with this finding, venom characterization via top-down and bottom-up proteomics, applied to both crude venoms and size-exclusion chromatographic fractions, revealed highly comparable venom compositions among the different populations. By combining all proteomics data, we identified 22 protein families from 102 liquid chromatography and tandem mass spectrometry (LC-MS/MS) raw files, including the most abundant snake venom metalloproteinases (SVMPs, 29-34%); phospholipase A2 (PLA2s, 26-31%); snake venom serine proteinases (SVSPs, 11-12%); l-amino acid oxidases (LAOs, 8-11%), C-type lectins/lectin-like (CTLs, 7-9%) protein families, and many newly detected ones, e.g., renin-like aspartic proteases (RLAPs), fibroblast growth factors (FGFs), peptidyl-prolyl cis-trans isomerases (PPIs), and venom vasodilator peptides (VVPs). Furthermore, we identified and characterized methylated, acetylated, and oxidized proteoforms relating to the PLA2 and disintegrin toxin families and the site of their modifications. It thus seems that post-translational modifications (PTMs) of toxins, particularly target lysine residues, may play an essential role in the structural and functional properties of venom proteins and might be able to influence the therapeutic response of antivenoms, to be investigated in future studies.


Assuntos
Proteômica , Venenos de Víboras , Animais , Cromatografia Líquida , Irã (Geográfico) , Espectrometria de Massas em Tandem , Venenos de Víboras/toxicidade
3.
J Proteome Res ; 19(8): 3022-3032, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32501701

RESUMO

The saw-scaled viper (Echis carinatus carinatus) is a major venomous snake in Sri Lanka (SL) responsible for massive numbers of snakebites on the island; nevertheless, its venom proteome composition has never been explored. The proteome composition of SL E. c. carinatus venom (SL ECV), revealed by tandem mass spectrometry analysis, showed that it is composed of 42 enzymatic and nonenzymatic proteins belonging to 12 snake venom protein families. Snake venom metalloproteases (SVMP) and snaclec comprised the most abundant enzymatic and nonenzymatic proteins, respectively. When the composition of SL ECV was compared to the previously determined venom composition of Southern India ECV (SI ECV), 16 proteins were found in common. The SL ECV proteome composition was correlated with the clinical manifestations and pathophysiology of E. c. carinatus envenomation in SL. Polyvalent antivenom (PAV) raised in equine against the "Big Four" venomous snakes of India is typically exported to SL for snakebite treatment; however, the poor immunological cross-reactivity, partial in vitro neutralization of enzymatic activities, and some pharmacological properties, mostly shown by low molecular mass toxins (25 kDa) of SL ECV by Indian PAVs are major concerns for the effective treatment of ECV envenomation in SL.


Assuntos
Proteômica , Mordeduras de Serpentes , Animais , Antivenenos , Cavalos , Índia , Sri Lanka , Venenos de Víboras
4.
Microb Pathog ; 143: 104121, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32169497

RESUMO

During a snake bite, the microbes may get transferred to the bite site and may cause secondary infection along with envenomation. The knowledge on the oral bacterial flora of snakes constitutes information important for snake bite management. The inadequately studied oral microflora of snakes differ geographically, temporally and among the members of the same species. The objective of this study is to determine the pattern of oral bacterial flora of Saw-scaled viper (Echis carinatus) and their susceptibility to antibiotics. Oral swabs were collected from nine healthy Saw-scaled vipers, subjected to microbiological, biochemical and molecular characterization. Additionally, these isolates were subjected to antimicrobial susceptibility testing using ICOSA-20-Plus and ICOSA-20-Minus. A wide range of pathogenic bacteria such as Salmonella arizonae, Pseudomonas stutzeri, Proteus penneri, Alcaligenes faecalis; Citrobacter diversus, C. freundii, Enterococcus faecalis, Bacillus anthracis, Staphylococcus sciuri and Achromobacter xylosoxidans were isolated as new additions to the floral diversity of saw scale viper. Most of the isolates were sensitive towards amikacin, azithromycin, imipenem, ciprofloxacin, gentamicin, ofloxacin, sparfloxacin, tobramycin, levofloxacin, kanamycin, tetracycline, and chloramphenicol while resistant to amoxyclav, cephalothin, cefpodoxime, Co-Trimoxazole, oxacillin and penicillin. The present study revealed that the bacterial flora of the oral cavity of Saw-scaled viper is resistant to many common antibiotics, which are often used for the treatment of snake-bite victims.


Assuntos
Antibacterianos/farmacologia , Microbiota/efeitos dos fármacos , Boca/microbiologia , Viperidae/microbiologia , Ampicilina/farmacologia , Animais , Azitromicina/farmacologia , Ceftizoxima/análogos & derivados , Ceftizoxima/farmacologia , Ciprofloxacina/farmacologia , Gentamicinas/farmacologia , Imipenem/farmacologia , Meticilina/farmacologia , Testes de Sensibilidade Microbiana , Microbiota/genética , Penicilinas/farmacologia , Filogenia , RNA Ribossômico 16S/genética , Cefpodoxima
5.
Biochim Biophys Acta Gen Subj ; 1861(3): 615-623, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28063984

RESUMO

BACKGROUND: Peptide and protein toxins are essential tools to dissect and probe the biology of their target receptors. Venoms target vital physiological processes to evoke pain. Snake venoms contain various factors with the ability to evoke, enhance and sustain pain sensation. While a number of venom-derived toxins were shown to directly target TRPV1 channels expressed on somatosensory nerve terminals to evoke pain response, such toxins were yet to be identified in snake venoms. METHODS: We screened Echis coloratus saw-scaled viper venom's protein fractions isolated by reversed phase HPLC for their ability to activate TRPV1 channels. To this end, we employed heterologous systems to analyze TRPV1 and NGF pathways by imaging and electrophysiology, combined with molecular biology, biochemical, and pharmacological tools. RESULTS: We identified TRPV1 activating proteins in the venom of Echis coloratus that produce a channel-dependent increase in intracellular calcium and outwardly rectifying currents in neurons and heterologous systems. Interestingly, channel activation was not mediated by any of its known toxin binding sites. Moreover, although NGF neurotropic activity was detected in this venom, TRPV1 activation was independent of NGF receptors. CONCLUSIONS: Echis coloratus venom contains proteins with the ability to directly activate TRPV1. This activity is independent of the NGF pathway and is not mediated by known TRPV1 toxins' binding sites. GENERAL SIGNIFICANCE: Our results could facilitate the discovery of new toxins targeting TRPV1 to enhance current understanding of this receptor activation mechanism. Furthermore, the findings of this study provide insight into the mechanism through which snakes' venom elicit pain.


Assuntos
Proteínas/metabolismo , Canais de Cátion TRPV/metabolismo , Venenos de Víboras/metabolismo , Viperidae/metabolismo , Animais , Sítios de Ligação/fisiologia , Cálcio/metabolismo , Linhagem Celular , Células HEK293 , Humanos , Fator de Crescimento Neural/metabolismo , Neurônios/metabolismo , Receptores de Fator de Crescimento Neural/metabolismo , Toxinas Biológicas/metabolismo
6.
Prague Med Rep ; 117(1): 61-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26995204

RESUMO

A snake breeder, 47-years-old man, was bitten by the saw-scaled viper (Echis carinatus sochureki). After admission to Toxinology Centre, within 1.5 h, laboratory evaluation showed clotting times prolonged to non-measurable values, afibrinogenaemia, significantly elevated D-dimers, haemolysis and myoglobin elevation. Currently unavailable antivenom was urgently imported and administered within 10 hours. In 24 hours, oligoanuric acute kidney injury (AKI) and mild acute respiratory distress syndrome (ARDS) developed. Despite administration of 10 vials of urgently imported Polyvalent Snake Antivenom Saudi Arabia, the venom-induced consumption coagulopathy (VICC) and AKI persisted. Another ten vials of antivenom were imported from abroad. VICC slowly subsided during the antivenom treatment and disappeared after administration of total 20 vials during 5 day period. No signs of haemorrhage were present during treatment. After resolving VICC, patient was transferred to Department of Nephrology for persisting AKI and requirement for haemodialysis. AKI completely resolved after 20 days. Despite rather timed administration of appropriate antivenom, VICC and AKI developed and the quantity of 20 vials was needed to cease acute symptoms of systemic envenoming. The course illustrates low immunogenicity of the venom haemocoagulation components and thus higher requirements of the antivenom in similar cases.


Assuntos
Injúria Renal Aguda , Antivenenos/administração & dosagem , Coagulação Sanguínea/efeitos dos fármacos , Mordeduras de Serpentes , Venenos de Víboras/toxicidade , Viperidae , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Animais , Testes de Coagulação Sanguínea/métodos , Relação Dose-Resposta a Droga , Humanos , Fatores Imunológicos/administração & dosagem , Masculino , Pessoa de Meia-Idade , Diálise Renal/métodos , Mordeduras de Serpentes/sangue , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/fisiopatologia , Mordeduras de Serpentes/terapia , Resultado do Tratamento
7.
J Pineal Res ; 56(3): 295-312, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24499241

RESUMO

Viper bites cause high morbidity and mortality worldwide and regarded as a neglected tropical disease affecting a large healthy population. Classical antivenom therapy has appreciably reduced the snakebite mortality rate; it apparently fails to tackle viper venom-induced local manifestations that persist even after the administration of antivenom. Recently, viper venom-induced oxidative stress and vital organ damage is deemed as yet another reason for concern; these are considered as postmedicated complications of viper bite. Thus, treating viper bite has become a challenge demanding new treatment strategies, auxiliary to antivenin therapy. In the last decade, several studies have reported the use of plant products and clinically approved drugs to neutralize venom-induced pharmacology. However, very few attempts were undertaken to study oxidative stress and vital organ damage. Based on this background, the present study evaluated the protective efficacy of melatonin in Echis carinatus (EC) venom-induced tissue necrosis, oxidative stress, and organ toxicity. The results demonstrated that melatonin efficiently alleviated EC venom-induced hemorrhage and myonecrosis. It also mitigated the altered levels of inflammatory mediators and oxidative stress markers of blood components in liver and kidney homogenates, and documented renal and hepatoprotective action of melatonin. The histopathology of skin, muscle, liver, and kidney tissues further substantiated the overall protection offered by melatonin against viper bite toxicities. Besides the inability of antivenoms to block local effects and the fact that melatonin is already a widely used drug promulgating a multitude of therapeutic functionalities, its use in viper bite management is of high interest and should be seriously considered.


Assuntos
Melatonina/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Mordeduras de Serpentes/tratamento farmacológico , Animais , Radicais Livres/metabolismo , Hemorragia/prevenção & controle , Mediadores da Inflamação/sangue , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Melatonina/administração & dosagem , Melatonina/farmacologia , Camundongos , Músculo Esquelético/patologia , Necrose/prevenção & controle , Ratos Wistar , Venenos de Víboras/toxicidade
8.
J Biochem Mol Toxicol ; 28(9): 407-12, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24888330

RESUMO

The effects of Echis pyramidum venom (EPV) (0.25, 0.50, and 1.00 mg/kg) on activities of superoxide dismutase (SOD) and catalase (CAT) and levels of thiobarbituric acid reactive substances (TBARS) and total thiols (T-SH) in liver and kidneys of rats were investigated. EPV significantly and dose dependently decreased the activities of SOD and CAT in livers. Although the kidney SOD and CAT activities were not affected by low and medium doses of EPV, the high dose significantly reduced the activities of these enzymes. Liver and kidney TBARS levels were not affected by the low and medium doses of EPV, whereas the high dose significantly increased the TBARS after 6 h postdosing. There was a significant depletion of T-SH in liver and kidneys of rats exposed to a high dose of EPV. The acute phase oxidative stress due to an EPV injection points toward the importance of an early antioxidant therapy for the management of snake bites.


Assuntos
Rim/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Venenos de Víboras/toxicidade , Viperidae , Animais , Catalase/metabolismo , Rim/patologia , Fígado/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo , Venenos de Víboras/química
9.
Toxicol Int ; 21(3): 325-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25948976

RESUMO

Common bleeding manifestations after viperine bite include bleeding from site of bite, bleeding gums, epistaxis, hemoptysis, hematuria, hematemesis, and intracranial bleed. Bleeding in the adrenal gland is a rare manifestation. We report here a patient of viperine bite who developed right adrenal hematoma and right hemothorax after 3 days of bite. To the best of our knowledge this is the first case report of adrenal hematoma and right hemothorax after Echis carinatus bite.

10.
Toxins (Basel) ; 16(9)2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39330854

RESUMO

The Eastern Long-Nosed Viper (Vipera ammodytes meridionalis) is considered one of the most venomous snakes in Europe. However, it is unknown whether ontogenetic variation in venom effects occurs in this subspecies and how this may impact antivenom efficacy. In this study, we compared the procoagulant activities of V. a. meridionalis venom on human plasma between neonate and adult venom phenotypes. We also examined the efficacy of three antivenoms-Viperfav, ViperaTAb, and Inoserp Europe-across our neonate and adult venom samples. While both neonate and adult V. a. meridionalis venoms produced procoagulant effects, the effects produced by neonate venom were more potent. Consistent with this, neonate venom was a stronger activator of blood-clotting zymogens, converting them into their active forms, with a rank order of Factor X >> Factor VII > Factor XII. Conversely, the less potent adult venom had a rank order of FXII marginally more activated than Factor VII, and both much more so than Factor X. This adds to the growing body of evidence that activation of factors besides FII (prothrombin) and FX are significant variables in reptile venom-induced coagulopathy. Although all three examined antivenoms displayed effective neutralization of both neonate and adult V. a. meridionalis venoms, they generally showed higher efficacy on adult venom than on neonate venom. The ranking of antivenom efficacy against neonate venom, from the most effective to the least effective, were Viperfav, Inoserp Europe, ViperaTAb; for adult venom, the ranking was Inoserp Europe, Viperfav, ViperaTAb. Our data reveal ontogenetic variation in V. a meridionalis, but this difference may not be of clinical concern as antivenom was effective at neutralizing both adult and neonate venom phenotypes. Regardless, our results highlight a previously undocumented ontogenetic shift, likely driven by the documented difference in prey preference observed for this species across age classes.


Assuntos
Antivenenos , Coagulação Sanguínea , Venenos de Víboras , Viperidae , Antivenenos/farmacologia , Animais , Humanos , Coagulação Sanguínea/efeitos dos fármacos , Vipera
11.
Anticancer Agents Med Chem ; 24(7): 533-543, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38243949

RESUMO

AIMS AND BACKGROUND: Echis carinatus venom is a toxic substance naturally produced by special glands in this snake species. Alongside various toxic properties, this venom has been used for its therapeutic effects, which are applicable in treating various cancers (liver, breast, etc.). OBJECTIVE: Nanotechnology-based drug delivery systems are suitable for protecting Echis carinatus venom against destruction and unwanted absorption. They can manage its controlled transfer and absorption, significantly reducing side effects. METHODS: In the present study, chitosan nanoparticles were prepared using the ionotropic gelation method with emulsion cross-linking. The venom's encapsulation efficiency, loading capacity, and release rate were calculated at certain time points. Moreover, the nanoparticles' optimal formulation and cytotoxic effects were determined using the MTT assay. RESULTS: The optimized nanoparticle formulation increases cell death induction in various cancerous cell lines. Moreover, chitosan nanoparticles loaded with Echis carinatus venom had a significant rate of cytotoxicity against cancer cells. CONCLUSION: It is proposed that this formulation may act as a suitable candidate for more extensive assessments of cancer treatment using nanotechnology-based drug delivery systems.


Assuntos
Antineoplásicos , Sobrevivência Celular , Quitosana , Ensaios de Seleção de Medicamentos Antitumorais , Nanopartículas , Quitosana/química , Quitosana/farmacologia , Humanos , Nanopartículas/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Venenos de Víboras/química , Venenos de Víboras/farmacologia , Proliferação de Células/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Relação Estrutura-Atividade , Tamanho da Partícula , Estrutura Molecular , Viperidae , Linhagem Celular Tumoral , Echis , Serpentes Peçonhentas , Polifosfatos
12.
BMC Pharmacol Toxicol ; 25(1): 46, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39123263

RESUMO

BACKGROUND: Echis ocellatus envenoming is potentially toxic initiating clinical damages on male reproductive system. Kaempferol is a therapeutic agent with neutralizing potentials on snake venom toxins. This study investigated the antagonistic effect of kaempferol on E. ocellatus venom (EoV)-induced reproductive toxicities. METHODS: Fifty adult male rats were sorted at random into five groups of ten rats for this study. The control rats were allotted to group 1, while rats in groups 2-5 were injected with 0.22 mg/kg bw (LD50) of EoV intraperitoneally. Rats in group 2 were not treated while groups 3-5 rats were treated with serum antivenom (0.2 ml), and 4 and 8 mg/kg bw of kaempferol post envenoming, respectively. RESULTS: EoV actuated reproductive toxicity, significantly decreased sperm parameters, and enhanced inflammatory, oxidative stress, and apoptotic biomarkers in reproductive organs of untreated envenomed rats. However, treatment with kaempferol alleviated the venom-induced reproductive disorders with a dose dependent effect. Kaempferol significantly increased the testicular weight, organo-somatic index, sperm parameters, and normalized the levels of serum luteinizing hormone, testosterone, and follicle stimulating hormone. Kaempferol ameliorated testicular and epididymal oxidative stress as evidenced by significant decrease in malondialdehyde (MDA) levels, enhancement of reduced glutathione (GSH) levels, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities. The inflammatory biomarkers; nitric oxide (NO) levels and myeloperoxidase activity (MPO), and apoptotic biomarkers; caspase 3 and caspase 9 activities were substantially suppressed in the testis and epididymis of envenomed rats treated with kaempferol. CONCLUSION: Results revealed kaempferol as a potential remedial agent against reproductive toxicity that could manifest post-viper envenoming.


Assuntos
Apoptose , Quempferóis , Espermatozoides , Testículo , Animais , Masculino , Ratos , Apoptose/efeitos dos fármacos , Echis , Inflamação/tratamento farmacológico , Inflamação/induzido quimicamente , Quempferóis/farmacologia , Quempferóis/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Espermatozoides/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/patologia , Testículo/metabolismo , Venenos de Víboras/toxicidade
13.
Toxicon ; 248: 107845, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38960288

RESUMO

Echis ocellatus is one of the commonest snakes responsible for envenomation in Nigeria. Antivenom is the only effective treatment, but the country suffers from a limited supply of effective antivenom. This study therefore aimed to explore the feasibility of effective, mono-specific antibodies production through immunization in rabbits using the venom of Echis ocellatus from Nigeria. The World Health Organization guide on antivenom production was employed in the immunization and the resultant antibodies were purified using protein A agarose column chromatography. Antibody titer reached a high plateau by 2-month immunization, and SDS PAGE of the sera suggests the presence of intact immunoglobulins accompanied with the heavy (50 kDa) and light (25 kDa) chains. The venom has an intravenous LD50 of 0.35 mg/kg in mice, and the venom lethality at a challenge dose of 2 LD50 was effectively neutralized by the antibodies with a potency value of 0.83 mg venom per g antibodies. The antibodies also neutralized the procoagulant activity of the venom with an effective dose (ED) of 13 ± 0.66 µl, supporting its use for hemotoxic envenomation. The study establishes the feasibility of developing effective, mono-specific antibodies against the Nigerian Carpet viper.


Assuntos
Antivenenos , Venenos de Víboras , Viperidae , Animais , Antivenenos/imunologia , Venenos de Víboras/imunologia , Venenos de Víboras/toxicidade , Coelhos , Nigéria , Camundongos , Dose Letal Mediana , Anticorpos/imunologia , Imunização , Mordeduras de Serpentes/imunologia , Echis
14.
Mol Immunol ; 165: 55-67, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38154407

RESUMO

Snake envenomation results in a range of clinical sequelae, and widely used animal-based conventional antivenoms exhibit several limitations including the adverse immunological effects in human snake bite victims. Therefore, human monoclonal anti-snake venom antibodies or fragments can be an alternate therapy for overcoming the existing limitations. We developed venom-neutralizing humanized scFv antibodies and analyzed biochemical mechanisms associated with the inhibition of toxicity. Tomlinson I and J human scFv antibody libraries were screened against Naja naja and Echis carinatus venoms, and seven unique scFv antibodies were obtained. Further, specific toxins of snake venom interacting with each of these scFvs were identified, and phospholipase A2 (PLA2) was found to be prominently captured by the phage-anchored scFv antibodies. Our study indicated PLA2 to be one of the abundant toxins in Naja naja and Echis carinatus venom samples. The scFvs binding to PLA2 were used to perform in vivo survival assay using the mouse model and in vitro toxin inhibition assays. scFv N194, which binds to acidic PLA2, protected 50% of mice treated with Naja naja venom. Significant prolongation of survival time and 16% survival were observed in Echis carinatus venom-challenged mice treated with scFv E113 and scFv E10, respectively. However, a combination comprised of an equal amount of two scFvs, E113 and E10, both interacting with basic PLA2, exhibited synergistically enhanced survival of 33% in Echis carinatus venom-challenged mice. No such synergistically enhanced survival was observed in the case of combinatorial treatment with anti-Naja naja scFvs, N194, and N248. These scFvs demonstrated partial inhibition of venom-induced myotoxicity, and E113 also inhibited hemolysis by 50%, which corroborates the enhanced survival during combinatorial treatment in Echis carinatus venom-challenged mice.


Assuntos
Anticorpos de Cadeia Única , Humanos , Animais , Camundongos , Naja naja , Echis , Venenos de Serpentes , Antivenenos , Fosfolipases A2 , Venenos Elapídicos
15.
Toxins (Basel) ; 16(8)2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39195771

RESUMO

Snake venoms are cocktails of biologically active molecules that have evolved to immobilize prey, but can also induce a severe pathology in humans that are bitten. While animal-derived polyclonal antivenoms are the primary treatment for snakebites, they often have limitations in efficacy and can cause severe adverse side effects. Building on recent efforts to develop improved antivenoms, notably through monoclonal antibodies, requires a comprehensive understanding of venom toxins. Among these toxins, snake venom metalloproteinases (SVMPs) play a pivotal role, particularly in viper envenomation, causing tissue damage, hemorrhage and coagulation disruption. One of the current challenges in the development of neutralizing monoclonal antibodies against SVMPs is the large size of the protein and the lack of existing knowledge of neutralizing epitopes. Here, we screened a synthetic human antibody library to isolate monoclonal antibodies against an SVMP from saw-scaled viper (genus Echis) venom. Upon characterization, several antibodies were identified that effectively blocked SVMP-mediated prothrombin activation. Cryo-electron microscopy revealed the structural basis of antibody-mediated neutralization, pinpointing the non-catalytic cysteine-rich domain of SVMPs as a crucial target. These findings emphasize the importance of understanding the molecular mechanisms of SVMPs to counter their toxic effects, thus advancing the development of more effective antivenoms.


Assuntos
Anticorpos Neutralizantes , Protrombina , Animais , Humanos , Anticorpos Neutralizantes/imunologia , Protrombina/imunologia , Protrombina/química , Antivenenos/farmacologia , Antivenenos/imunologia , Antivenenos/química , Venenos de Víboras/imunologia , Venenos de Víboras/química , Venenos de Víboras/toxicidade , Cisteína/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Metaloproteases/química , Metaloproteases/imunologia , Domínios Proteicos , Viperidae
16.
Toxicol Rep ; 13: 101721, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39295951

RESUMO

We describe 5 cases of envenomation and complications related to saw scaled viper (Echis carinatus) bites from the Western Ghats region of Karnataka over a period of 5 years (December 2019-May 2023). Although the smallest member of the Big Four, Saw Scaled viper envenomation is associated with significant morbidity. In our region, envenomation appears to be rare. The careful review of all these cases has suggested VICC with one patient having persistent coagulopathy despite adequate ASV administration, and three patients developing anaphylaxis. It needs to be brought to notice that the complications due to envenoming run high, despite timely administration of ASV. Through these cases, we want to contribute evidence suggesting variable efficacy of Indian polyvalent ASV for Echis carinatus bites and the need for updating protocols for the same.

17.
Biochem Biophys Rep ; 38: 101701, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38601750

RESUMO

This work aimed to purify the proteins that cause blood coagulation in the venom of the Iranian Echis carinatus snake species in a comprehensive manner. Gel filtration chromatography (GFC), Ion exchange chromatography (IEC), and Size Exclusion High-Performance Liquid Chromatography (SEC-HPLC) were utilized in the purification of the coagulation factors. The prothrombin clotting time (PRCT) and SDS-PAGE electrophoresis were performed to confirm the coagulative fractions. The fraction with the shortest coagulation time was selected. The components of this designated fraction were identified through matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF) following thorough purification. Circular dichroism (CD) was employed to determine the second structure of the coagulation factor. The crude venom (CV) was analyzed and had a total protein concentration of 97%. Furthermore, the PRCT of the crude venom solution at a concentration of 1 mg/ml was determined to be 24.19 ± 1.05 s. The dosage administered was found to be a factor in the venom's capacity to induce hemolysis. According to CD analysis, the protein under investigation had a helical structure of 16.7%, a beta structure of 41%, and a turn structure of 9.8%. CHNS proved that the purified coagulant protein had a Carbon content of 77.82%, 5.66% Hydrogen, 3.19% Nitrogen, and 0.49% Sulphur. In the present investigation, a particular type of snake venom metalloproteinase (SVMP) has undergone the process of purification and characterization and has been designated as EC-124. This purified fraction shows significant efficacy as a procoagulant. Our findings have shown that this compound has a function similar to factor X and most likely it can cause blood coagulation by activating factor II (FII).

18.
JMIR Hum Factors ; 11: e47081, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38437008

RESUMO

BACKGROUND: IT has brought remarkable change in bridging the digital gap in resource-constrained regions and advancing the health care system worldwide. Community-based information systems and mobile apps have been extensively developed and deployed to quantify and support health services delivered by community health workers. The success and failure of a digital health information system depends on whether and how it is used. Ethiopia is scaling up its electronic community health information system (eCHIS) to support the work of health extension workers (HEWs). For successful implementation, more evidence was required about the factors that may affect the willingness of HEWs to use the eCHIS. OBJECTIVE: This study aimed to assess HEWs' intentions to use the eCHIS for health data management and service provision. METHODS: A cross-sectional study design was conducted among 456 HEWs in 6 pilot districts of the Central Gondar zone, Northwest Ethiopia. A Unified Theory of Acceptance and Use of Technology model was used to investigate HEWs' intention to use the eCHIS. Data were cleaned, entered into Epi-data (version 4.02; EpiData Association), and exported to SPSS (version 26; IBM Corp) for analysis using the AMOS 23 Structural Equation Model. The statistical significance of dependent and independent variables in the model was reported using a 95% CI with a corresponding P value of <.05. RESULTS: A total of 456 HEWs participated in the study, with a response rate of 99%. The mean age of the study participants was 28 (SD 4.8) years. Our study revealed that about 179 (39.3%; 95% CI 34.7%-43.9%) participants intended to use the eCHIS for community health data generation, use, and service provision. Effort expectancy (ß=0.256; P=.007), self-expectancy (ß=0.096; P=.04), social influence (ß=0.203; P=.02), and hedonic motivation (ß=0.217; P=.03) were significantly associated with HEWs' intention to use the eCHIS. CONCLUSIONS: HEWs need to be computer literate and understand their role with the eCHIS. Ensuring that the system is easy and enjoyable for them to use is important for implementation and effective health data management.


Assuntos
Sistemas de Informação em Saúde , Intenção , Humanos , Adulto , Estudos Transversais , Etiópia , Agentes Comunitários de Saúde , Eletrônica
19.
Toxicon ; 229: 107138, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37127124

RESUMO

African trypanosomiasis is an infectious disease caused by hemoparasites of the genus Trypanosoma and remains a major health problem in Africa - killing around 4000 people and animals worth an estimated $5 billion, annually. The absence of a vaccine and satisfactory drug against African trypanosomiasis (AT) necessitates the continued search for new chemotherapy options. Owing to the rich biochemical diversity in snake venom, it has recently become a source of therapeutic peptides that are being explored for the development of novel drug candidates for diverse ailments such as cancers and infectious diseases. To explore this, Echis ocellatus venom (EOV) was investigated for the presence of an anti-Trypanosoma factor, with the subsequent aim to isolate and identify it. Crude EOV was collected and tested in vitro on the bloodstream form (BSF) i.e. long and slender morphological form of Trypanosoma brucei and T. congolense. This initial testing was followed by a sequential anti-trypanosomal assay guided purification of EOV using ethanol precipitation, distillation, and ion exchange (IEX) chromatography to obtain the active trypanocidal component. The purified anti-Trypanosoma factor, estimated to be a 52-kDa protein on SDS-PAGE, was subjected to in-gel trypsin digestion and 2D RP HPLC-MS/MS to identify the protein. The anti-Trypanosoma factor was revealed to be a zinc-dependent metalloproteinase that contains the HEXXHXXGXXH adamalysin motif. This protein may provide a conceptual framework for the possible design of a safe and effective anti-trypanosomal peptide for the treatment of AT.


Assuntos
Trypanosoma , Tripanossomíase Africana , Viperidae , Animais , Venenos de Víboras/química , Tripanossomíase Africana/tratamento farmacológico , Espectrometria de Massas em Tandem , Viperidae/metabolismo , Metaloproteases/metabolismo
20.
J Clin Med ; 12(12)2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37373825

RESUMO

Venomous snake bites can constitute medical emergencies, and without immediate care may be life-threatening. This study describes the characteristics and management of patients suffering from snake bite injuries (SNIs) in the Jerusalem area. A retrospective analysis of all patients who were admitted to the Hadassah Medical Center emergency departments (EDs) due to SNIs between 1 January 2004 and 31 March 2018 was conducted. During this period, 104 patients were diagnosed with SNIs, of whom 32 (30.7%) were children. Overall, 74 (71.1%) patients were treated with antivenom, 43 (41.3%) were admitted to intensive care units, and 9 (8.6%) required treatment with vasopressors. No mortality was recorded. On ED admission, none of the adult patients presented with an altered mental state compared to 15.6% of the children (p < 0.00001). Cardiovascular symptoms were observed in 18.8% and 5.5% of the children and adults, respectively. Fang marks appeared in all of the children. These findings underscore the severity of SNIs and the differences in clinical presentation between children and adults in the Jerusalem region.

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