Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 44
Filter
Add more filters











Publication year range
1.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;30: e20230046, 2024. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1528980

ABSTRACT

Tityus serrulatus scorpion is responsible for a significant number of envenomings in Brazil, ranging from mild to severe, and in some cases, leading to fatalities. While supportive care is the primary treatment modality, moderate and severe cases require antivenom administration despite potential limitations and adverse effects. The remarkable proliferation of T. serrulatus scorpions, attributed to their biology and asexual reproduction, contributes to a high incidence of envenomation. T. serrulatus scorpion venom predominantly consists of short proteins acting as neurotoxins (α and ß), that primarily target ion channels. Nevertheless, high molecular weight compounds, including metalloproteases, serine proteases, phospholipases, and hyaluronidases, are also present in the venom. These compounds play a crucial role in envenomation, influencing the severity of symptoms and the spread of venom. This review endeavors to comprehensively understand the T. serrulatus scorpion venom by elucidating the primary high molecular weight compounds and exploring their potential contributions to envenomation. Understanding these compounds' mechanisms of action can aid in developing more effective treatments and prevention strategies, ultimately mitigating the impact of scorpion envenomation on public health in Brazil.


Subject(s)
Animals , Scorpion Venoms/analysis , Scorpion Venoms/chemistry , Peptide Hydrolases , Phospholipases , Glycoproteins , Hyaluronoglucosaminidase
2.
Toxicon ; 184: 10-18, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32479835

ABSTRACT

In this communication the isolation, chemical and physiological characterization of three new toxins from the scorpion Centruroides baergi are reported. Their immunoreactive properties with scFvs generated in our group are described. The three new peptides, named Cb1, Cb2 and Cb3 affect voltage-dependent Na+ channels in a differential manner. These characteristics, explain the toxicity of this venom. Molecular interactions in real-time among these toxins and the best recombinant antibodies generated in our group, revealed that one of them was able to neutralize the main toxin of this venom (Cb1). These results represent an important advance for the neutralization of this venom and serve as the basis for generating new scFvs that will allow the neutralization of similar toxins from other venoms that have no yet been neutralized.


Subject(s)
Scorpion Venoms/analysis , Scorpions , Amino Acid Sequence , Animals , Electrophysiological Phenomena , Mexico , Recombinant Proteins , Scorpion Venoms/immunology , Sequence Alignment , Single-Chain Antibodies
3.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 26: e20200128, 2020. graf
Article in English | VETINDEX | ID: vti-32206

ABSTRACT

As in previous contributions to the JVATiTD, the aim of this note is to bring some general information on a particular aspect of the scorpion biology. An attempt is made to explain the possible coevolution of telson morphology and venom glands, which took place during several hundred million years and in particular since scorpions migrated from aquatic to terrestrial environments. Three components can be directly associated with predation and defensive behaviours: (1) morphology of the chelae and structure of the chelae fingers granulations; (2) morphology of the metasoma and in particular of the telson; (3) evolution of tegumentary glands in the telson toward different types of venom glands. Since a number of recent contributions already treated some of these aspects, I will limit my comments to the possible evolution of the telson in relation to the evolution of venom glands. As in previous contributions, the content of this article is basically addressed to non-specialists on scorpions whose research embraces scorpions in several fields such as venom toxins and public health.(AU)


Subject(s)
Animals , Scorpion Venoms/analysis , Scorpion Venoms/biosynthesis , Animal Shells/chemistry , Biological Coevolution
4.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;24: 1-8, 2018. graf, tab
Article in English | LILACS, VETINDEX | ID: biblio-1484752

ABSTRACT

Background Centruroides hirsutipalpus, of the family Buthidae, is a scorpion endemic to the Western Pacific region of Mexico. Although medically important, its venom has not yet been studied. Therefore, this communication aims to identify their venom components and possible functions. Methods Fingerprinting mass analysis of the soluble venom from this scorpion was achieved by high-performance liquid chromatography and electrospray mass spectrometry. Furthermore, the soluble venom and its toxic effects were evaluated extensively via electrophysiological assays in HEK cells expressing human voltage-gated Na+ channels (hNav 1.1 to Nav1.6), CHO cells expressing hNav 1.7, potassium channel hERG 1 (Ether-à-go-go-related-gene) and the human K+-channel hKv1.1. Results The separation of soluble venom produced 60 fractions from which 83 distinct components were identified. The molecular mass distribution of these components varies from 340 to 21,120 Da. Most of the peptides have a molecular weight between 7001 and 8000 Da (46% components), a range that usually corresponds to peptides known to affect Na+ channels. Peptides with molecular masses from 3000 to 5000 Da (28% of the components) were identified within the range corresponding to K+-channel blocking toxins. Two peptides were obtained in pure format and completely sequenced: one with 29 amino acids, showing sequence similarity to an "orphan peptide" of C. limpidus, and the other with 65 amino acid residues shown to be an arthropod toxin (lethal to crustaceans and toxic to crickets). The electrophysiological results of the whole soluble venom show a beta type modification of the currents of channels Nav1.1, Nav1.2 and Nav1.6. The main effect observed in channels hERG and hKv 1.1 was a reduction of the currents. ..


Subject(s)
Animals , Electrophysiology , Scorpions , DNA Fingerprinting , Scorpion Venoms/analysis
5.
Article in English | VETINDEX | ID: vti-734601

ABSTRACT

Background Centruroides hirsutipalpus, of the family Buthidae, is a scorpion endemic to the Western Pacific region of Mexico. Although medically important, its venom has not yet been studied. Therefore, this communication aims to identify their venom components and possible functions. Methods Fingerprinting mass analysis of the soluble venom from this scorpion was achieved by high-performance liquid chromatography and electrospray mass spectrometry. Furthermore, the soluble venom and its toxic effects were evaluated extensively via electrophysiological assays in HEK cells expressing human voltage-gated Na+ channels (hNav 1.1 to Nav1.6), CHO cells expressing hNav 1.7, potassium channel hERG 1 (Ether-à-go-go-related-gene) and the human K+-channel hKv1.1. Results The separation of soluble venom produced 60 fractions from which 83 distinct components were identified. The molecular mass distribution of these components varies from 340 to 21,120 Da. Most of the peptides have a molecular weight between 7001 and 8000 Da (46% components), a range that usually corresponds to peptides known to affect Na+ channels. Peptides with molecular masses from 3000 to 5000 Da (28% of the components) were identified within the range corresponding to K+-channel blocking toxins. Two peptides were obtained in pure format and completely sequenced: one with 29 amino acids, showing sequence similarity to an "orphan peptide" of C. limpidus, and the other with 65 amino acid residues shown to be an arthropod toxin (lethal to crustaceans and toxic to crickets). The electrophysiological results of the whole soluble venom show a beta type modification of the currents of channels Nav1.1, Nav1.2 and Nav1.6. The main effect observed in channels hERG and hKv 1.1 was a reduction of the currents. ..(AU)


Subject(s)
Animals , Scorpions , Scorpion Venoms/analysis , Electrophysiology , DNA Fingerprinting
6.
Toxicon ; 88: 88-92, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24932739

ABSTRACT

Anti-Tityus discrepans F(ab')2 ELISA recognition of T. discrepans toxins was measured with regression analysis and its slope called ELISA recognition value (ERv). Fractions containing toxins affecting mammal macrophages or Na(+)-channels have Ervs >19. Toxins affecting potassium channels or insect NaV channels have ERvs <10. Fractions including curarizing or antineoplasic peptides had ERvs <1. Erv increases in proportion to mammalian toxin toxicity rather than to toxin molecular mass.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin Fab Fragments/immunology , Scorpion Venoms/analysis , Animals , Horses , Molecular Weight , Scorpion Venoms/immunology
7.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;2004/02/2014.
Article in English | LILACS | ID: lil-724679

ABSTRACT

Scorpion envenoming is a public health problem in Brazil, where Tityus serrulatus and T. bahiensis are considered the most dangerous scorpions. They are well adapted to urbanized environments, and there is an increasing probability of human exposure to these venoms, including during pregnancy. Not much is known about the effects of prenatal exposure to the venom, and no information is available to aid in the rational treatment of victims stung during pregnancy. Thus, this study aimed to investigate whether venom from the scorpion T. bahiensis administered once to pregnant female rats at a dose that causes a moderate envenomation may lead to deleterious effects on the reproductive performance of the dams and on the development of their offspring. This is the first work demonstrating that T. bahiensis venom, when administered experimentally to rats, alters maternal reproductive performance and the morphological development of fetuses. The venom was given to dams on the 5th (GD5) or on the 10th (GD10) gestational day. After laparotomy, on GD21, fetuses and placentas were counted, weighed and externally analyzed. The corpora lutea were counted. The sex and vitality of fetuses were evaluated, and each litter was then randomly divided for visceral or skeletal analyses. Data were analyzed by ANOVA followed by the Tukey-Kramer test and Fisher's exact test. The significance level for all tests was set at p < 0.05.


Subject(s)
Animals , Pregnancy, Animal/immunology , Rats/metabolism , Scorpion Venoms/analysis , Scorpions/classification
8.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;20: 1-9, 04/02/2014. ilus, tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1484568

ABSTRACT

Scorpion envenoming is a public health problem in Brazil, where Tityus serrulatus and T. bahiensis are considered the most dangerous scorpions. They are well adapted to urbanized environments, and there is an increasing probability of human exposure to these venoms, including during pregnancy. Not much is known about the effects of prenatal exposure to the venom, and no information is available to aid in the rational treatment of victims stung during pregnancy. Thus, this study aimed to investigate whether venom from the scorpion T. bahiensis administered once to pregnant female rats at a dose that causes a moderate envenomation may lead to deleterious effects on the reproductive performance of the dams and on the development of their offspring. This is the first work demonstrating that T. bahiensis venom, when administered experimentally to rats, alters maternal reproductive performance and the morphological development of fetuses. The venom was given to dams on the 5th (GD5) or on the 10th (GD10) gestational day. After laparotomy, on GD21, fetuses and placentas were counted, weighed and externally analyzed. The corpora lutea were counted. The sex and vitality of fetuses were evaluated, and each litter was then randomly divided for visceral or skeletal analyses. Data were analyzed by ANOVA followed by the Tukey-Kramer test and Fisher's exact test. The significance level for all tests was set at p < 0.05.


Subject(s)
Animals , Pregnancy, Animal/immunology , Rats/metabolism , Scorpion Venoms/analysis , Scorpions/classification
9.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 20: 1-9, 2014. ilus, tab, graf
Article in English | VETINDEX | ID: vti-10964

ABSTRACT

Scorpion envenoming is a public health problem in Brazil, where Tityus serrulatus and T. bahiensis are considered the most dangerous scorpions. They are well adapted to urbanized environments, and there is an increasing probability of human exposure to these venoms, including during pregnancy. Not much is known about the effects of prenatal exposure to the venom, and no information is available to aid in the rational treatment of victims stung during pregnancy. Thus, this study aimed to investigate whether venom from the scorpion T. bahiensis administered once to pregnant female rats at a dose that causes a moderate envenomation may lead to deleterious effects on the reproductive performance of the dams and on the development of their offspring. This is the first work demonstrating that T. bahiensis venom, when administered experimentally to rats, alters maternal reproductive performance and the morphological development of fetuses. The venom was given to dams on the 5th (GD5) or on the 10th (GD10) gestational day. After laparotomy, on GD21, fetuses and placentas were counted, weighed and externally analyzed. The corpora lutea were counted. The sex and vitality of fetuses were evaluated, and each litter was then randomly divided for visceral or skeletal analyses. Data were analyzed by ANOVA followed by the Tukey-Kramer test and Fisher's exact test. The significance level for all tests was set at p < 0.05.(AU)


Subject(s)
Animals , Rats/metabolism , Pregnancy, Animal/immunology , Scorpion Venoms/analysis , Scorpions/classification
10.
Acta toxicol. argent ; 21(1): 26-32, jun. 2013. graf, tab
Article in English | LILACS | ID: lil-694582

ABSTRACT

Tityus discrepans venom (TdV) produces a variety of haemostatic manifestations including alveoli fbrin deposition and/ or prothrombin and partial thromboplastin time (PT, PTT) alterations in mammals. In vitro studies have demonstrated that TdV contains tissue plasminogen activator-like (t-PA), fbrinolytic and plasmin inhibitory compounds and produces platelets activation through GPVI and a novel Src-dependent signalling pathway. The aim of this study is to describe the initial characterization of procoagulant and anticoagulant components from TdV. This venom was fractionated by exclusion molecular chromatography on a Sephadex G-50 column. The eluted material was collected as fve fractions called S1 to S5. These fractions and the whole venom were used to evaluate factor Xa- and thrombin-like activities, fbrinogen degradation, furthermore thrombin- and factor Xa-inhibitory activities. The results demonstrated that TdV contain components with factor Xa-like activity (procoagulants) as well fbrinogenolytic compounds present in the fraction S1 and components with factor Xa inhibitory activity in the fractions S4 and S5 (anticoagulants).


El veneno de Tityus discrepans (TdV) produce en mamíferos una variedad de manifestaciones hemostáticas tales como depósitos de fbrina en alveolos y/o alteración en los tiempos de protrombina y tromboplastina parcial (PT, PTT). Estudios in vitro han demostrado que el TdV contiene componentes semejantes al activador del plasminógeno tipo tisular (t-PA), fbrino-líticos, compuestos que inhiben la actividad de plasmina y además componentes que promueven la activación de plaquetas a través del receptor GPVI y por una nueva vía de señalización dependiente de las Src kinasas. El objetivo de este estudio es describir la caracterización inicial de componentes procoagulantes y anticoagulantes a partir del TdV. Este veneno fue fraccionado por cromatografía de exclusión molecular sobre una columna Sephadex G-50. El material eluido fue colectado en cinco fracciones denominadas S1 a S5. Estas fracciones y el veneno completo fueron usados para evaluar actividades semejantes a factor Xa y trombina, degradación de fbrinógeno, como también la inhibición de la actividad del factor Xa y de la trombina. Los resultados demostraron que TdV contiene componentes con actividad semejante al factor Xa (procoagulantes) y compuestos fbrinogenolíticos presentes en la fracción S1, además de componentes con actividad inhibitoria del factor Xa presentes en la fracción S4 y S5 (anticoagulantes).


Subject(s)
Blood Coagulation , Factor Xa , Fibrinolysis , Scorpion Venoms/analysis , Scorpion Venoms/enzymology , Anticoagulants , Coagulants , Scorpion Venoms/chemical synthesis
11.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;19: 1-7, maio 2013.
Article in English | LILACS, VETINDEX | ID: biblio-1484528

ABSTRACT

Previous works had shown that scorpion venom induced neurotransmitter elevation and an inflammatory response associated with various anatomo-pathological modifications. The most dangerous scorpions species in Algeria responsible for these effects are Androctonus australis hector(Aah) and Androctonus amoreuxi (Aam). Results Comparison of the physiopathological effects induced by the two venoms showed differences in the kinetic of cytokine release and in lung injury. The lung edema was only observed in response to Aah venom and it was correlated with cell infiltration. In order to better understand the involved mechanism in inflammatory response, we used two antagonists, atropine (non-selective muscarinic antagonist) and propranolol (β adrenergic antagonist), which lead to a decrease of cell infiltration but has no effect on edema forming.Conclusion These results suggest another pathway in the development of lung injury following envenomation with Aam or Aah venom.


Subject(s)
Animals , Atropine/analysis , Cytokines/biosynthesis , Propranolol/analysis , Scorpion Venoms/analysis , Scorpions/classification
12.
Article in English | VETINDEX | ID: vti-9292

ABSTRACT

Previous works had shown that scorpion venom induced neurotransmitter elevation and an inflammatory response associated with various anatomo-pathological modifications. The most dangerous scorpions species in Algeria responsible for these effects are Androctonus australis hector(Aah) and Androctonus amoreuxi (Aam). Results Comparison of the physiopathological effects induced by the two venoms showed differences in the kinetic of cytokine release and in lung injury. The lung edema was only observed in response to Aah venom and it was correlated with cell infiltration. In order to better understand the involved mechanism in inflammatory response, we used two antagonists, atropine (non-selective muscarinic antagonist) and propranolol (β adrenergic antagonist), which lead to a decrease of cell infiltration but has no effect on edema forming.Conclusion These results suggest another pathway in the development of lung injury following envenomation with Aam or Aah venom.(AU)


Subject(s)
Animals , Scorpion Venoms/analysis , Atropine/analysis , Propranolol/analysis , Cytokines/biosynthesis , Scorpions/classification
13.
Article in English | VETINDEX | ID: vti-9284

ABSTRACT

The present study compared two methods used successfully in a large-scale program for the collection of scorpion venoms, namely the milking of adult scorpions via manual and electrical stimulation. Results Our immunobiochemical characterizations clearly demonstrate that regularly applied electrical stimulation obtains scorpion venom more easily and, most importantly, in greater quantity. Qualitatively, the electrically collected venom showed lack of hemolymph contaminants such as hemocyanin. In contrast, manual obtainment of venom subjects scorpions to maximal trauma, leading to hemocyanin secretion. Our study highlighted the importance of reducing scorpion trauma during venom milking. Conclusions In conclusion, to produce high quality antivenom with specific antibodies, it is necessary to collect venom by the gentler electrical stimulation method.(AU)


Subject(s)
Animals , Scorpion Venoms/analysis , Antivenins/analysis , Mortality , Scorpions
14.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 18(4): 361-368, 2012. ilus, tab
Article in English | VETINDEX | ID: vti-9229

ABSTRACT

Although the main Malian scorpion species of medical interest, Androctonus amoreuxi, is responsible for severe envenomings and perhaps some deaths, it has hitherto been considered not dangerous for humans. This population is located in the Saharian North-Eastern regions of Mali where it is accompanied by Leiurus quinquestriatus, a well known dangerous species of the Sahara. In the Gao district, divided by the Niger River, less desolate than the Tessalit and Kidal regions, one specimen of the dangerous species Androctonus australis was found. To summarize, Mali harbors at least three dangerous scorpion species: Leiurus quinquestriatus, Androctonus amoreuxi and A. australis, the latter recently having been identified in Mali for the first time. The absence of Androctonus aeneas is surprising in this context because it is found in neighboring countries (Algeria, Niger) and should be detected by new surveys. The possibility of preparing a single scorpion antivenom intended for Saharian and sub-Saharian populations is discussed.(AU)


Subject(s)
Animals , Fauna/analysis , Scorpion Venoms/analysis , Public Health , Risk
15.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 18(4): 375-383, 2012. ilus, tab
Article in English | VETINDEX | ID: vti-9227

ABSTRACT

The purpose of the present study was to investigate the biodistribution profile of the venom of Hemiscorpius lepturus, the most dangerous scorpion in Iran. Blood and tissue samples were taken at various predetermined intervals during a 400-minute period for the venom and a 360-minute period for the antivenom in rats. The radio-iodination was carried out using the chloramine-T method. The results showed that the descending order of venom uptake was skin, kidneys and intestine, respectively. The descending order of polyclonal antivenom uptake was kidneys, intestine, heart and lungs. The calculated pharmacokinetic parameters of the venom were Telimination half-life = 521.5 ± 12.6 minutes; Vd/F (apparent volume of distribution) = 14.9 ± 3.3 mL; clearance (CL/F, apparent total clearance of the drug from plasma) 0.02 ± 0.005 mL/minute and for the antivenom Telimination half-life = 113.7 ± 7.4 minutes; Vd/F = 13 ± 1.2 mL and CL/F 0.08 ± 0.01 mL/minute. The pharmacokinetics profile comparison of the venom with that of the antivenom shows that serotherapy may be more effective if administered within 2-4 hours following envenomation by H. lepturus.(AU)


Subject(s)
Animals , Rats , Scorpion Venoms/analysis , Antivenins/analysis , Rats/classification , Tissue Array Analysis
16.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 18(4): 462-466, 2012. ilus
Article in English | VETINDEX | ID: vti-9219

ABSTRACT

We report a case in which a 21-week pregnant woman was stung by a Euscorpius flavicaudis (De Geer, 1778) scorpion. Symptoms and signs experienced by the patient were the same as those documented in the literature and with no ill-effects for the pregnancy. Envenoming was local and of low degree of intensity. It is important to emphasize that the patient was stung in her home, which differs from stings in most other parts of the world, in which scorpionism is mostly a risk in outdoor areas.(AU)


Subject(s)
Humans , Animals , Scorpion Venoms/analysis , Pregnancy/metabolism , Signs and Symptoms/methods
17.
J. Venom. Anim. Toxins incl. Trop. Dis. ; 16(2): 198-211, 2010. ilus, mapas
Article in English | VETINDEX | ID: vti-4269

ABSTRACT

Scorpion stings constitute a common type of accident in Turkey due to the geographic location, climate and socioeconomic structure of this country. Moreover, envenomation cases are considered a public health problem throughout Turkey. Based on data in the literature, the main clinical features of scorpion envenomations are defined as systemic manifestations including sweating, hypertension and vomiting, and among prominent causes of death are cardiorespiratory manifestations, toxic myocarditis and pulmonary edema. The most important health-threatening scorpions found in Turkey are: Androctonus crassicauda, Leiurus quinquestriatus, Mesobuthus gibbosus and Mesobuthus eupeus, all of which belong to the Buthidae family. This study indicates that there is no data related to venom toxicity and in vivo effects of other scorpions found in Turkey - such as Mesobuthus caucasicus, Mesobuthus nigrocinctus and Hottentotta saulcyi - and that further research should be performed to determine their health effects.(AU)


Subject(s)
Animals , Scorpion Venoms/analysis , Scorpion Venoms/poisoning , Public Health/education
18.
Article in English | VETINDEX | ID: vti-4228

ABSTRACT

In this study, the morphology, histology and fine structure of the stinger, a part of the venom apparatus of Euscorpius mingrelicus (Kessler, 1874) (Scorpiones: Euscorpiidae) were studied by light microscopy and transmission electron microscopy (TEM). The stinger, located at the end section of the telson, is sickle-shaped. The venom is ejected through a pair of venom pores on its subterminal portion. Both venom ducts extend along the stinger without contact with each other since they are separated by connective tissue cells. The stinger cuticle is composed of two layers. Additionally, there are many pore canals and some hemolymph vessels in the cuticle. This work constitutes the first histological and fine structure study on Euscorpius mingrelicus stinger.(AU)


Subject(s)
Animals , Scorpions/physiology , Scorpion Venoms/analysis , Microscopy/methods , Microscopy/veterinary , Microscopy, Electron, Transmission/methods , Microscopy, Electron, Transmission/veterinary , Glutaral , Sodium Compounds
19.
J Proteomics ; 72(2): 183-99, 2009 Mar 06.
Article in English | MEDLINE | ID: mdl-19457345

ABSTRACT

This communication revises the state of the art concerning antivenoms against snakes, spiders and scorpions. An overview of the historical facts that preceded the therapeutic use of antibodies is mentioned. A brief list of the major protein components of these venomous animals is revised with a short discussion of what is known on the proteomic analysis of their venoms, but the emphasis is placed on the type of antivenoms available commercially, including pertinent literature and addresses of the companies that prepare these antivenoms. The final section revises and discusses current research on the field and new potential applications that are being developed geared at obtaining new therapeutic antibodies or fragments of antibodies for neutralization of toxic components of venomous animals.


Subject(s)
Antivenins/analysis , Proteomics/methods , Scorpion Venoms/toxicity , Snake Venoms/toxicity , Spider Venoms/toxicity , Animals , Antivenins/immunology , Chromatography, High Pressure Liquid , Humans , Immunoglobulin G/chemistry , Mice , Proteome , Recombinant Proteins/chemistry , Scorpion Venoms/analysis , Scorpions , Snake Venoms/analysis , Spider Venoms/analysis , Spiders
20.
São Paulo; s.n; 06 mar. 2009. 121 p. ilus, graf, tab.
Thesis in Portuguese | LILACS | ID: lil-525307

ABSTRACT

O transplante de ilhotas pancreáticas humanas representa uma estratégia promissora para a cura do diabetes mellitus tipo 1 (DM1) mas a aplicação a todos os pacientes diabéticos ainda é impraticável devido à limitada disponibilidade de ilhotas ou células β e à necessidade de utilização de drogas imunossupressoras pelo paciente transplantado. O tratamento com imunossupressores após o transplante de ilhotas pode ser abolido quando se realiza o microencapsulamento das ilhotas pancreáticas. Neste trabalho investigou-se um novo biomaterial, Biodritina (alginato/sulfato de condroitina) adequado ao microencapsulamento que gelifica na presença de íons de cálcio ou bário. A biocompatibilidade das microcápsulas tem sido avaliada segundo o grau de pureza do alginato utilizado na sua confecção. Amostras de alginato comercial purificado foram analisadas, comprovando-se a presença de impurezas (polifenóis, endotoxinas, proteínas) em níveis elevados, que impedem sua aplicação clínica. Optou-se, portanto pela utilização do alginato comercial ultrapurificado nos experimentos descritos neste trabalho. Das formulações de biomateriais avaliadas, as microcápsulas de bário-Biodritina apresentaram o melhor desempenho em testes de estabilidade físico-química...


Subject(s)
Animals , Mice , Rats , Diabetes Mellitus/immunology , Diabetes Mellitus/metabolism , Gene Expression/genetics , In Vitro Techniques , Islets of Langerhans/cytology , Islets of Langerhans/immunology , Islets of Langerhans Transplantation/immunology , Scorpion Venoms/analysis , Scorpion Venoms/biosynthesis , Cadaver , Islets of Langerhans/ultrastructure , Microscopy, Electron, Scanning , Biocompatible Materials/pharmacokinetics , Cell Proliferation
SELECTION OF CITATIONS
SEARCH DETAIL